Reflective Account of Increasing a Persons Observations

Reflective Account of Increasing a Persons Observations on an Acute Mental Health WardThis essay will discus a decision that was made on a local male acute ward. Using this example, an analysis of the decision making process has been made and a reflective model has been used in order to generate personal knowledge that will inform further practice (Rolfe, 2011a). A pseudonym of Tim has been used for the discussed patient to maintain confidentiality in accordance with the NMC code of conduct (2010a). Observation is one way in which mental health nurses can protect acutely mentally ill inpatients from harm and is commonly implemented for patients who impose a risk of harming themselves, others and for those who are vulnerable (Bowers et al, 2006). Tim, who was on a local male acute ward, posed a risk of harming himself and became very vulnerable during his stay. On admission he was perceived to be at low risk of harming himself and vulnerability, therefore was observed on the minimum level of observation, general observation, which includes all patients and involves an hourly eyesight check on the patient (DH, 1999; NICE, 2005). The decision to increase his observation level was jointly taken by the mentor and the author by gathering information from bank support workers about Tim's current presentation. After a noted deterioration in Tim's mental health, it was decided to increase observations to within eyesight of staff. Justification for this was that he was becoming a serious risk of harming himself as he threatened to jump from the ward roof, as he was determined to leave. Tim was detained under section 2 or the mental health act (DH, 2007). He felt that he needed to leave in order to find his son who he had recently lost contact with. He had been stopped attempting to climb a drain pipe to leave via the ward roof and had been in a very distressed state. Eyesight level of observation is seen as the second highest of four levels and demands intense nursing, only within arms length is higher (DH, 1999; Jones & Eales, 2009; NICE, 2005). Close observation is an example of decision making which is exclusive to mental health nursing. The Chief Nursing Officer described observation as a key area where good practice is essential and that nurses should ‘demonstrate an understanding of the benefits and limitations of the use of levels of observation to maximise the therapeutic effect on inpatient units’ (DH, 2006). Additionally NICE (2005) recommends the use of observation in the short-term management of disturbed/violent patients. The Nursing and Midwifery Council (NMC, 2010a) require nurses to be able to apply knowledge and an appropriate repertoire of skills that is indicative of safe and effective practice and based on the best available evidence. At the time of making the decision it seemed the right course of action. The mentor's final decision was taken for granted as he was an experienced nurse and a lack of personal experience meant that the author had limited personal experience to work with. Before undertaking this assignment it could not decided what could be done differently if faced with a similar situation on qualification. On qualification, such a decision will have to be well informed and made with confidence and one that has to be made in accordance with the NMC code of professional conduct (2010) which requires nurses to be accountable for their own actions and omissions in practice. By using the decision making tool below the advantage of hindsight can be used when analysing this decision to better inform future practice. Pritchard (2006) sees decision making as one of the most difficult processes that a nurse can undertake and one of the most important parts of nursing practice. Aitkin (2003) concludes that formal decision analysis can improve future decision making. The utilised decision making model, as described by Jasper (2003), asks the questions Who/What/When/Where/Why and How? These questions make a useful contribution to systematic, holistic, clinical judgement and enable evaluation and critical thinking about the made decision to take place Jasper, 2003; Standing, 2011). Tim has a long history of mental illness and was admitted to the ward following a deterioration in his mental illness after he lost contact with his son. His mood was elevated and he felt very restless and agitated. Prior to admission, he was found police in a very distressed state. Tim was placed on a section 2 of the mental health act (DH, 2007) and was originally observed generally where a member of staff would have to see him face to face on a hourly basis (NICE, 2005). Under section 2 of the mental health act Tim has lost the right to leave hospital at will and his responsible clinician has not granted him section 17 leave. A person can be detained for up to 28 days and treat against their will (DH, 2007). As Tim was detained it was important for staff to keep him on the ward. Increasing attempts by Tim to leave led to a change in observation level to within eyesight to make sure he did not leave the ward by any means. Staff levels were low, and for that reason it was felt that there was not enough staff to informally observe Tim. In addition there was a general feeling of fear that if Tim left the ward there would be inevitable consequences for the staff. The literature shows that the decision to increase a persons observations is common when faced with the above situation. Buchanan-Barker ; Barker (2005) are critical at the increase of observations on acute mental health wards following high profile tragedies placing practitioners in defensive mode to stop patient elopements and harm to patients. Organisations have responded to this risk by formalising observation policies to defend themselves against litigation. In addition, it is felt that observation policies dominate practice and reassure distant managers that ‘something is being done' (Horsfall ; Cleary, 2000). Equally, nurses use observation in ‘defensive mode' in order to prevent harm. Despite these measures, the effectiveness of observation to reducing patient risk and providing a therapeutic benefit is not at all clear (Mana, 2010). This indicates that observation is driven by risk culture and defensive practices concerned with physical integrity of the person and do little to address the origin of a person's distress (Cutcliffe & Stephenson, 2008; Buchanan-Barker & Barker, 2005). Tim was finding it hard to cope with the loss of his son and wants to leave the ward to find him. One study found that the most cited reason for ncreasing levels of close observations was the prevention of absconding from an acute ward which could lead to the patients self-harm, neglect vulnerability and violence (Dennis, 1997). During Tim's observation staff were tired and unwilling to engage with Tim. Staff were seen to be following Tim from one part of the unit to another which was aggravating him further. The observation was void of conversation which is in contrast to Peplau's (195 2) view that clinical observation should be carried out with the nurses attention to the interpersonal relationship with the patient. Likewise, Rooney (2009) reports that nurses acknowledged that observations were more about prevention than cure and keeping the patient safe was priority. On the other hand, Bowles et al (2002) found that distressed patients need both containment and engagement. In conclusion, there was a need to maintain a therapeutic relationship while considering the management of risk and the empowerment of the patient. The mental Health Act (DH, 2007) requires an appropriate package of treatment to be in place which includes one-toone time with staff which could have helped alleviate Tim's anxiety. Short staffing meant that Tim's one-to-one time had not taken place and from a personal view point a package that can only be theoretically provided is not be good enough. Bank support workers had been allocated to observe Tim as the qualified nurse had to complete paperwork. This is in agreement with the findings of Rooney (2009) who reported that observation was usually left to unqualified staff as nurses were often dealing with other matters. In contrast, NICE (2005) states that observation should be undertaken by registered nurses. Nurses may delegate to competent staff who have had the appropriate training. It is thought that the bank staff did not have the appropriate level of competence which created a poor skill mix on that shift which Aston et al (2010) see as a barrier to good decision making. In agreement Rooney (2009) found that staff acknowledged therapeutic work could take place during times of observation however, they felt that they lacked the relevant skills. Staff reported that no one had ever explained how to interact with the patient or had received any further guidance beyond the aspects of risk management and containment. Most nurses who took part in this study had no practical or theoretical preparation for observations. Tim attempts to leave by the door on the ward when it is opened for visitors and he will try several times a day to enter the court yard to leave by climbing onto the roof. The high level of staffing resources taken up by preventing Tim from leaving the ward prevented staff from engaging with other patients who felt that they were being ignored and neglected which in turn added further stress to staff. In agreement are a number of authors who have shown that formal observations consume nursing resources and that the patient being observed receive a disproportionate amount of nurses time (Mana, 2010; Bowles et al, 2002). Bowles et al (2002) argued that the time taken up by the demands of observation was to the detriment of of care of patients that were not seen as a high risk. To reflect on the above experience Rolfe's framework has been used which poses the questions what? , so what? , now what? (Rolfe, 2001; 2011a). This type of reflection which is done after and away from the actual event is referred to by Schon (1983) as reflection-on-action and the following discussion focusses on how the author and others did and what changes could be made. Despite this type of reflection being useful reflection-in-action is seen to have far more significance in professional practice. Reflection-in-action looks at the suitability of a particular intervention while it is been carried out. This is one of the distinguishing features as a nurse progresses from qualified status to an advanced practitioner (Schon, 1983; Rolfe, 2011b). In terms of clinical reasoning and decision making, reflection is seen as an invaluable resource for developing personal practice and learning from other people's perspectives (Aston et al, 2010). In addition to this, reflection can generate knowledge from practice rather than relying on external research findings (Rolfe, 2011a). Rolfe's (2001) framework allows the construction of personal theory and knowledge and how a similar situations outcome might be improved by future actions. The NMC makes it clear that nurses should take part in appropriate learning that helps develop competence and performance (NMC, 2010a). According to Benner's (2001) novice to expert the author recognises that as a management student working towards qualification he needs to be a proficient performer who looks at situations as a whole rather than their constituent parts. In strong agreement, Aston (2011), who uses a skills escalator approach, places a management student at level 4 which is a level where a student is expected to demonstrate they can draw on a wide range of resources using an evidence based rational for decisions. When the author collaborated with staff to assist in making a decision for Tim he felt equally involved in the decision making process however personal contribution was lacking due to limited knowledge at that time. The NMC (2010a) require that care is based on the best available evidence or best practice. The author's personal decision was not based on either. Furthermore, Aston (2010) recommends that confidence in making a decision is developed by a number of factors including relevant past experiences and practising using decision making skills. Pritchard (2006) argues that the process of decision making is learned gradually through practical experience of caring for patients and observing more experienced colleagues making decisions. Further inhibiting the authors ability to make a decision was a theory practice gap (Aston, 2010). This indicates that the author was practising at Benner's (2001) novice stage, in that he had entered a new clinical area and had a limited contextual understanding. The author was too inexperienced to made the above decision. Tim was placed on eyesight observations and the permanent presence of staff upset him. Tim was feeling distress and anger. There were no positive outcomes and the intervention was not effective meaning the wrong decision may have been made. Personal decisions and actions were not based on evidence or experience. One of the barriers to future decision making is making mistakes and reflection is one way of recognising what could have been done better. In addition, in the new clinical environment, the author should have been assisted to practice safely under constant supervision and possibly not able to make such a decision at this stage of nursing training (Aitkin, 2003). Despite this being the case a thorough theoretical knowledge before working on the ward would have better prepared the author for making the decision. In contrast to this is the notion that a nurse who is experienced in working with theoretical knowledge will find differences in practice that the formal theory fails to express (Benner, 2001). This indicates that a new understanding of the situation has been reached. Despite no real harm coming to Tim the author was not in a position to assist in making the decision. The author should have declined stating that he did not have the relevant knowledge. It is clear that the author had a low critical thinking capability at that time. It is argued that this is a problem faced by newly qualified nurses. Graduates do not meet expectations for entry level clinical judgement ability (Del Bueno, 2005). Similarly, Deuchester (2009) reports that newly qualified nurses go through a transition shock and have a poor ability to make decisions. Feelings of doubt, loss, confusion and disorientation for newly qualified nurses are reported along with a lack of knowledge that includes practical, theoretical and tacit. Despite this being the case the NMC (2010b) require students to demonstrate the ability to work as autonomous practitioners by the point of registration. Del Bueno (2005) concludes that newly qualified nurses should be expected to think critically and use clinical judgement in order to develop it. In conclusion the broader issues that have arose from this are that time needs to be taken to stop and think and consider whether whether the decision is meeting the patients needs. The main learning, for future practice, is to make sure that the author is exposed to as many situations as possible to gain practical knowledge. In addition, theoretical gaps in knowledge need to be eliminated in future practice. The best attempt to engage with the patient needs to be sought in the future. If observation levels needs to be increased the decision should be weighed up against the patient being allowed to move freely and not feel restricted and Mental Health Act (2007) requirements of offering one to one-to-one sessions.

Apple Introduction: Iphone, Ipad and the Company Essay

Apple Inc. (Apple), incorporated on January 3, 1977, designs, manufactures and markets mobile communication and media devices, personal computers, and portable digital music players, and sells a variety of related software, services, peripherals, networking solutions, and third-party digital content and applications. The Company’s products and services include iPhone, iPad, Mac, iPod, Apple TV, a portfolio of consumer and professional software applications, the iOS and OS X operating systems, iCloud, and a variety of accessory, service and support offerings. The Company also sells and delivers digital content and applications through the iTunes Store, App StoreSM, iBookstoreSM, and Mac App Store. The Company sells its products worldwide through its retail stores, online stores, and direct sales force, as well as through third-party cellular network carriers, wholesalers, retailers, and value-added resellers. In February 2012, the Company acquired app-search engine Chomp. See more: how to write an introduction paragraph for an essay The Company offers a range of mobile communication and media devices, personal computing products, and portable digital music players, as well as a variety of related software, services, peripherals, networking solutions and third-party hardware and software products. In addition, the Company offers its own software products, including iOS, the Company’s mobile operating system; OS X, the Company’s Mac operating system; and server and application software. The Company’s primary products include iPhone, iPad, Mac, iPod, iTunes, Mac App Store, iCloud, Operating System Software, Application Software and Other Application Software. iPhone iPhone combines a mobile phone, an iPod, and an Internet communications device in a single handheld product. Based on the Company’s Multi-Touch user interface, iPhone features desktop-class email, Web browsing, searching, and maps and is compatible with both Mac and Windows-based computers. iPhone automatically syncs content from users’ iTunes libraries, as well as contacts, bookmarks, and email accounts. iPhone allows customers to access the iTunes Store to download audio and video files, as well as a variety of other digital content and applications. In September 2012, the Company launched iPhone 5, its latest version of iPhone. In addition to the Company’s own iPhone accessories, third-party iPhone compatible accessories are available through the Company’s online and retail stores and from third parties. iPad iPad is a multi-purpose mobile device for browsing the Web, reading and sending email, viewing photos, watching videos, listening to music, playing games, reading e-books and more. iPad is based on the Company’s Multi-Touch technology and allows customers to connect with their applications and content in a more interactive way. iPad allows customers to access the iTunes Store to download audio and video files, as well as a variety of other digital content and applications. In March 2012, the Company launched the iPad, its third generation iPad, and in October 2012, the Company announced its fourth generation iPad and iPad mini. In addition to the Company’s own iPad accessories, third-party iPad compatible accessories are available through the Company’s online and retail stores and from third parties. Mac The Company offers a range of personal computing products, including desktop and portable computers, related devices and peripherals, and third-party hardware products. The Company’s Mac desktop and portable systems feature Intel microprocessors, the OS X operating system and the iLife suite of software for creation and management of digital photography, music, movies, DVDs and Websites. The Company’s desktop computers include iMac, Mac Pro and Mac mini. The Company’s portable computers include MacBook Pro and MacBook Air. iPod The Company’s iPod line of portable digital music and media players includes iPod touch, iPod nano, iPod shuffle and iPod classic. All iPods work with iTunes. In addition to the Company’s own iPod accessories, third-party iPod-compatible accessories are available through the Company’s online and retail stores and from third parties. The iPod touch, based on iOS, is a flash-memory-based iPod with a widescreen Retina display, a Multi-Touch user interface, and built-in iSight camera. iPod touch allows customers to access the iTunes Store to download audio and video content, as well as a variety of digital applications. The iPod nano is a flash-memory-based iPod that features the Company’s Multi-Touch interface allowing customers to navigate their music collection by tapping or swiping the display and built-in Bluetooth for wireless listening. The iPod shuffle is a flash-memory- based iPod that features a clickable control pad to control music playback and VoiceOver technology enabling customers to hear song titles, artists and playlist names. The iPod classic is a hard-drive based portable digital music and video player. iTunes iTunes is an application that supports the purchase, download, organization and playback of digital audio and video files and is available for both Mac and Windows-based computers. iTunes features integration with iCloud, AirPlay wireless music playback, Genius Mixes, Home Sharing, and syncing functionality with iOS devices. iTunes is integrated with the iTunes Store, a service that allows customers to discover, purchase, rent, and download digital content and applications. The iTunes Store includes the App Store and iBookstore. Mac App Store The Mac App Store allows customers to discover, download and install Mac applications. The Mac App Store offers applications in education, games, graphics and design, lifestyle, productivity, utilities and other categories. The Company’s OS X operating system software and its iLife, iWork and other application software titles are also available on the Mac App Store. iCloud iCloud is the Company’s cloud service, which stores music, photos, applications, contacts, calendars, and documents and wirelessly pushes them to multiple iOS devices, Mac and Windows-based computers. iCloud’s features include iTunes in the Cloud, Photo Stream, Documents in the Cloud, Contacts, Calendar, Mail, automatic downloads and purchase history for applications and iBooks, and iCloud Backup. Users can sign up for free access to iCloud using a device running qualifying versions of iOS or OS X. Software Products and Operating System Software The Company offers a range of software products for consumers and for SMB, education, enterprise and government customers, including the Company’s iOS and OS X operating system software; server software; professional application software; and consumer, education, and business oriented application software. iOS is the Company’s mobile operating system that serves as the foundation for iOS devices. iOS supports iCloud and includes features, such as Notification Center, a way to view and manage notifications in one place; iMessage, a messaging service that allows users to send text messages, photos and videos between iOS devices, and Maps, with turn-by-turn navigation. iOS supports Siri, a voice activated intelligent assistant, which is available on qualifying iOS devices. OS X, the Company’s Mac operating system, is built on an open-source UNIX-based foundation. Application Software iLife is the Company’s consumer-oriented digital lifestyle application suite included with all Mac computers. iLife features iPhoto, iMovie, iDigital Versatile Disc (DVD), GarageBand and iWeb. iPhoto is the Company’s consumer-oriented digital photo application and iMovie is the Company’s consumer-oriented digital video editing software application. iDVD is the Company’s consumer-oriented software application that enables customers to turn iMovie files, QuickTime files, and digital pictures into interactive DVDs. GarageBand is the Company’s consumer-oriented music creation application that allows customers to play, record and create music. iWeb allows customers to create online photo albums, blogs and podcasts, and to customize websites using editing tools. iWork is the Company’s integrated productivity suite designed to help users create, present, and publish documents, presentations, and spreadsheets. iWork includes Pages for word processing and page layout, Keynote for presentations, and Numbers for spreadsheets. The Company also has a Multi-Touch version of each iWork application designed specifically for use on iOS devices. Other Application Software The Company also sells various other application software, including Final Cut Pro, Logic Studio, Logic Pro, and its FileMaker Pro database software. The Company manufactures the Apple LED Cinema Display and Thunderbolt Display. The Company also sells a range of Apple-branded and third-party Mac-compatible and iOS-compatible peripheral products, including printers, storage devices, computer memory, digital video and still cameras, and various other computing products and supplies. Apple TV allows customers to watch movies and television shows on their high definition television. Content from iTunes, Netflix, YouTube, and Flickr, as well as music, photos, videos, and podcasts from a Mac or Windows-based computer can also be wirelessly streamed to a television through Apple TV. Strategy Implementation in Apple Inc Apple Inc. Is arguably one of the most successful companies in the world, enjoying one of the most visible brand names in the world. Its launch of new products is usually waited with heightened anticipation by consumers around the world, and its financial performance has been exemplary. This success can be attributed to two main factors; the visionary leadership offered by its immediate former chief executive Steve Job and the strategic goal of emphasizing on design and the willingness to develop new products by taking risk of developing new products for the market. The strategic goal of developing new products, while at the same time emphasizing on design, has been successful because it has utilized the components of strategic implementation. The allocation of resources by the company in the developing of new products has been substantial, and more often in well thought and planned processes. The financial resources focused on the development of new products with new and superior designs can be said to follow Sun Tzu’s strategic principles of knowing oneself and knowing the enemy, who in this case would be the competitors. Apple Inc., by utilizing the superior capabilities in its possession, has been able to develop products superior to those developed by its competitors and thus acquiring a valuable market segment. The institution of best practices for continuous development has seen Apple Inc. Develop some of the best practices in design in the industry. The quality standards in Apple are some of the best, and the design teams in the company are reputed to put in some extreme efforts to ensure that the products developed are of the best standard possible. Tying rewards to the achievement of key strategic goals can also be said to be a factor in the success of the design strategy of the company. The remuneration process of offering bonuses at the good performance of the company can be said to be a motivation to the employees of the company to develop better performing products. Since Steve Jobs joined the company in 1998, the company has been growing in leaps and bounds simply because of the building of a capable organization by focusing on the areas of improvement. The company has been able to make a focus on the development of new products of superior design to those of competitors, and has improved continuously on these products. Steve Jobs can be compared to the military genius with all the traits developed by Clausewitz; intellect, courage to develop new products for the market, ability to adapt to changes and strength of character. These traits of the chief can be said to have contributed to the strategic success of the company. The support systems employed in Apple Inc are some of the best, and the company being in the electronics and telecommunications business has seen to it that their implementation is well carried out. The company has numerous operation centres spread across the globe and despite this the working towards the development and production of new products seems seamless because of this excellent support system utilised by the company’s employees. Communication between the layers of operations of the company is seamless, and no time and resources are wasted on the process of communicating decisions and feedback between the hierarchical levels of the company. This can be likened to Sun Tzu’s advocacy for speed in battle; good support systems offer an opportunity for fast and efficient decision making which ultimately leads to corporate success. The policies of the company that have been established in the recent past indicate their supportiveness to the strategy of developing new products superior in design, one of the eight components of implementing strategy. The outsourcing of production of apple products to China can be used as an example of this, with the goal of reducing production costs while maintaining the high quality of the products.

Underage drinking

Underage Drinking underage drinkers drink to look cool and It may be the social thing to do at the latest party or even at home; feeling curious a teen may consume alcohol to tit in with their surroundings. This can be due to the fact that the minor could be pressured into drinking. With all the popular media hype about alcohol and especially during the Super Bowl; it Just shows minors that it is okay to participate in drinking and if they do, this great boost will occur.The other cause to these other Influences could have already had happened, such as the childhood experience being abused by the runken father or alcoholic mother who does not nurture her children. Underage drinking Is detrimental to the health of themselves and others whom they affect: It Is an ongoing problem that continues, with the number of students Increasing each year Drinking underage can be linked to advertising that is very persuasive to the minors. These advertisements, some say target children, but the alc ohol companies deny.In efforts to prove the people wrong; alcohol companies have put forth their part into making an advertisement discouraging alcohol abuse. The advertisements ake the young minded minors to think drinking can put on physical attractiveness, It is fun, or gives special powers to make the person better at athletics. Some would soy the audience that Is targeted In the beer advertisements. such ds Bud Light, are Indeed minors, seeing an alcoholic beverage and having the appeal to take acuon are different. ne of the advertisements by Bug Light were shown on the super Bowl commercials ot people stranded on an island; they found a radio, but instead ot using it to find help, they found a cart of alcoholic beverages and showed them aving the best time on the island. The reality of this commercial is saying to teens, if you drink alcohol you will have the best time of your life. Especially, when those minors are being pressured into by their peers to take the shot, it make s the situation Into a more dangerous one.Having a party with friends Is one thing, but If that party host has access to their parents liquor stash It becomes d different party. â€Å"Rates are higher among 12th graders, with reporting at least one alcoholic drink during their lifetime, 43% reported at least one drink In the past 30 days, 28% reporting runkenness in the past 30 days, and reported daily use ot alcohol (Centers tor Disease Control and Prevention, 2008; Johnson et al. , 2009! ‘ (Song).These statistics are also closely related to my own experience, my own friends would come to the football game under the influence or go to the party this weekend which had alcohol. Drinking while in high school can also be lead to drinking in college, but the major dfference Is that alcohol is more demanding dt the college parties. Minor's consequences on whom drinks can also Increase their risk of unhealthy outcomes; uch as fighting one another. which can lead to Injuries, reckle ss sexual behavior and drlvlng under the Influence. hile many do not have parents who have alcohol at their house, there are many ways ot obtaining alcohol by having take ID's, by asking a stranger and giving them extra money for buying the booze for them; making college parties that much easier to obtain alcohol. â€Å"Researchers have identified a number of factors that contribute to adolescent alcohol use, including being male, having easy peers also drink alcohol† (Song). Minors receive biases messages about alcohol, it can e from the D. A. R. E program that educates the minors about the drugs and what it does to their bodies.The other messages could be from biased adults and popular media whom say one drink will not hurt, but the fact is that one drink can harm the body of the minor in psychological and physical ways. One of the counter arguments about underage drinking is lowering the drinking age to prevent binge-drinking at age 18 or 19 years old. â€Å"The problem i s that underage drinking is now forced off campus, leading to â€Å"a culture of dangerous, clandestine binge-drinking† (Alcoholism Drug Abuse Weekly). Having the law as it is, makes the drinking go farther than the campus walls.If the age at which people are legal to drink is lowered, then the developing minds that are affected by the alcohol can reduce the minor's chances of being successful. Having the age at 21 is good, not only does it prevent alcohol- related trauma, â€Å"But 10 percent of a state's federal highway funds are cut if the state doesn't mandate a drinking age of 21† (Alcoholism & Drug Abuse Weekly). Popular media, community norms, and peer pressure, all have a fundamental root cause to hy adolescents drink at such an early age, it is because of their childhood experience.In order to be able to understand why college students are drinking at such an early age, analyzing how they were raised and their family life can be a big factor. One's childhood e xperience can drastically take for the worst if their mother, father, or parental guardian is a drunk. Every night they would come home from drinking at the bar, see their child and tell them that everything is okay; the child would start to develop the idea that coming home drunk is an okay thing to do.The reason for the child's drinking at an early age would be to cope with such a graphic image of their parent figure drinking and acting out violently towards their loved ones, â€Å"First, it created physical and emotional stress, which participants believed could be reduced through alcohol use. Second, victims of abuse began â€Å"to stop caring† about what happened to them or what people thought about their behavior. Third, many abuse victims absented themselves in order to escape the abuse, removing themselves to unsupervised or risky settings where they were offered, or it as easy to obtain, alcohol and drugs† (Rothman).The turn to alcohol is easy with a motive, s uch as lessening or not dealing with the burden put on the child through the traumatization. The risks to drinking can be the underdevelopment of the brain, although the changes are subtle, over a long period of time it can be noticeable. The liver and the growth hormones are affected by the consumption of alcohol at the early ages; they tend to produce a lot of liver enzyme, which is indicating some liver damage and throwing off the hormones of the adolescent's puberty stage.With the umber of the population increasing, so does the student body, thus resulting in the pressures of drinking at an early age because of the ongoing problem with underage drinking. The cycle of underage drinking would occur, if the parents are young and are not ready to deal with a child; so when the child is growing the parents might be drinking because of the stress of dealing with the financial troubles if present. The problem on campus is not because the college students are doing it because they can, it is a variety of issues that causes them to take the drink at the college party.This problem is need of the utmost attention because it affects the student life on pressures of drinking or taking the load off. Its impact on the community is detrimental to their personal health, but also the safety of others due to the fact that driving under the influence can be fatal to not only themselves, but whom they cause harm to. Work Cited Rothman, Emily F. , Judith Bernstein, and Lee Strunin. â€Å"Why Might Adverse Childhood Experiences Lead To Underage Drinking Among US Youth? Findings From An Emergency Department-Based Qualitative Pilot Study.

Service Improvement Initiative Essay Example | Topics and Well Written Essays - 2000 words

Service Improvement Initiative - Essay Example The observation and information gathering process was focused on information such as various quantities in various containers and coming up with the short-notes on the guide. In addition, a period of four months was taken for the project trial using prototype short-notes which were followed by regular nurses meetings to discuss and monitor its progress. Resources Used Past and present fluid balance charts are essential in carrying out an audit to assess the effectiveness and in aiding better documentation. There was also the use of a measuring scale to determine the correct quantities in the containers. In addition, there was the utilization of excel application to generate the table used to enter the data for ease of comparison and analysis. Finally, there was the utilization of colour printer and laminating machines to print and prepare robust short notes. Who Was Involved The people who were involved include nurses and the entire team of healthcare professional assistants as well as other members from multi-professional field like the registrars, dieticians, occupational therapists and physiotherapists. Outcome/ Evaluation The fluid balance charts illustrate a better documentation of the fluid information. ... Finally, I intend to broadcast this idea for all healthcare workers. Introduction Haematology entails studying the blood, blood diseases, and the organs which form blood. Haematology also entails the study of diagnosis, prognosis, etiology, prevention, and treatment, and prognosis of blood diseases which affect the making of blood and its elements, for example, blood proteins, haemoglobin, blood cells, and the mechanism of coagulation (Nathan, Orkin, Ginsburg & Look 2003, p. 12). Health expert’s daily responsibility largely entails the treatment and care of patients suffering from haematological diseases (Department of Health 2007, p. 31). Fluid care is essential for people suffering from haematological diseases. Fluid management helps in the reinstatement of circulating volume and adequate management of blood element replacement. Also, haematopathologists and haematologists usually work together to develop a diagnosis and provide the most adequate therapy if required. This pa per will look at a service improvement initiative within the haematology ward (Chin 2008, p. 54). The paper will examine a service improvement initiative that I hope will be helpful for patients in the haematology ward. This point of view was initially highlighted when talking about my pledge with my mentor. My pledge is to always keep my patients hydrated. In addition, the conversation assisted me to develop a strategy utilizing the NOLAN technique, PDSA (Plan Do Study Act) so as to facilitate the service improvement. The paper will go on to evaluate a number of theoretical aspects including change Management, accountability and responsibility,

3-page case study on recent developments of Napster and its industry Essay

3-page case study on recent developments of Napster and its industry - Essay Example After a takeover offer of $2.43 million by the Private Media Group, Napsters brand and logos were acquired at bankruptcy auction by the company Roxio, Inc in 2002 and the online service was called as pressplay in 2003. At present Napster, LLC (formerly Roxio, Inc.) is an online music provider offering a variety of purchase and subscription models. The new legal online music service let user’s access music through a subscription or on a fee-per-song basis. The Napster PC-based subscription service is currently available in the U.S., UK, Canada, Germany and Japan. There are two types of subscription service offering at present Napster To Go, The portable subscription tier, which offers music fans to unlimited transfer of music to their choice of compatible MP3 players, cell phones and PDAs in addition to unlimited streaming and PC downloading for $14.95 per month. Napster also offers Napster Light, pay-per-track (no monthly subscription fee) and Napster.com, a free advertising supported website that enables full-length versions of over 3 million tracks three times to stream/listen . It had also launched NapsterLinks, which links to all of the music in Napster catalog that can be embedded into WebPages, blogs or in emails for sharing anywhere on the web. Napster also offers a mobile music service called as Napster Mobile. This service enables mobile users to search and browse Napster’s music catalog and preview, purchase and play songs on their mobile handset through an integrated music player. June 27, 2006: The availability of Napster 3.7, an updated version of its PC application featuring PowerSync, which optimized the process of transferring subscription music content to compatible MP3 players. May 12, 2006: The launch of Napster.com as a free advertising supported website that enables full-length versions of over 3 million tracks three times to

Analyze the Current Presidential Campaign Essay

Analyze the Current Presidential Campaign - Essay Example The USA administers general elections for its highest official post of the president of the country after every four years on 4th of November in the leap year. These elections are watched and observed with great curiosity all over the world, and people from different regions of the globe remain well informed regarding the latest developments being made during the election campaign. Problems are discussed, issues are raised and promises are made, according to the prevailing situation, with the people by the presidential candidates. There was a time, when the election campaign of the country was determined by targeting the growing Russian threat, though it has become quite a stalemate during the contemporary era, and the candidates have to set other targets in order to capture the attention of the subjects. â€Å"The United States†, Rice submits, â€Å"has found it exceedingly difficult to define its "national interest" in the absence of Soviet power. That we do not know how to think about what follows the U.S.-Soviet confrontation is clear from the continued references to the "post-Cold War period." Yet such periods of transition are important, because they offer strategic opportunities. During these fluid times, one can affect the shape of the world to come.† (Rice, 2000: retrieved in the Council of Foreign Affairs) Now terrorism, wars in Iraq and Afghanistan, price hike of oil products, globalization, the unabated unemployment and widening gulf between the USA and Iran have become the moot point especially during the present campaign for the presidency of the USA. Since this year 2008 is also the election year, many candidates appeared during the election campaign to participate the elections, and arranged demonstration in order to introduce themselves in public. The public listened to the points raised by these candidates and analyzed them in the perspective of the existing uncertain state of

Strategic Management and International Business at Starbucks Case Study - 46

Strategic Management and International Business at Starbucks - Case Study Example Starbucks should create winning strategies by coming up with a cohesive, energized and happy team, which will create a strong bond with the customers and ensure growth (Enz, 2010; Godin, 2006). It is undoubtedly that corporate success is not a guarantee and the probability of a firm having a long-term success heightens when strategic leaders continue to evaluate the appropriateness of the strategies developed as well as actions that are taken in an effort to implement them. It is obvious that the McDonald’s is a major competitive threat since its coffee drinks are meant to create value to the consumers by giving them high-quality experience at a lower price than that of Starbucks. Therefore, one of the ways in which Starbucks can ensure a competitive advantage is by developing a sound mechanism by which it can combine authority, relative value, and quality. It should have an ideal pricing strategy whereby consumers feel that they are getting a great deal for their money. It also needs to maintain strict and solid quality controls with regard to its coffee sourcing. Starbucks should also spend more time differentiating from its rivals and be up to date with the latest technology to outwit its competitors. It should also continue positioning itself as an authoritative figure, allowing premium prices where necessary. It should aim at improving on its brand and reputation by carrying out a survey on what the customers think of the corporation and ways it can improve (Hitt, Ireland & Hoskisson, 2010). The decision to fire Donald was appropriate considering that Starbucks was performing poorly against the Nasdaq index for the quarterly financials that preceded his ouster. During his reign, the coffee stock plummeted by 50%; hence, needed a leader who can drive changes such as encouraging international expansion and streamlining the management of the firm.  

The Impact of Political Institutions Essay Example | Topics and Well Written Essays - 500 words

The Impact of Political Institutions - Essay Example The Scottish Parliament is composed of 129 members of Parliament (MPs), directly elected by Scottish voters, who make laws regarding domestic issues such as crime and justice, education, health, agriculture, environment, transport, economic development and local government (Calman Commission, 2009, p.4). The Parliament at Westminster, with 59 Scottish MPs, makes laws regarding security, foreign affairs and social security (Calman Commission, 2009, p.4). The Scottish Executive is then in charge of enforcing these laws. Whereas the Scottish Parliament benefits financially from the central government’s money, it has no real power over its taxes. Scotland receives 60% of its spending from the British tax income (Calman Commission, 2009, p.4). However, with regard to economic independence, Scotland is allowed to vary the basic income tax by up to 3 pence in the pound taxed (Calman Commission, 2009, p.4). Thus, though politically independent, Scottish Treasury has no economic independence from the rest of the UK. This dependence is historical. Scotland has always had economic ties to the rest of the country, but has constitutionally been independent (Calman Commission, 2009, p.5 - 6). Due to the 1707 Act of Union, Scotland was allowed to retain its own judicial and educational system. However, economy and legislature, as well as the executive branches became subject to the Parliament at Westminster (Raco, 2003, p.80). The devolution of power is only a symmetrical copy of the historical structure of the UK before 1707. The US has a federalist system, unlike the UK. The UK is still an overwhelmingly unitary nation - state, where the central government controls everything (Vile, 2007, p.3). The US has a federalist system with separation of power between the judiciary, legislative and executive branches (Vile, 2007, p.3). Unlike the British system of central government, the US

Case study Essay Example | Topics and Well Written Essays - 250 words - 17

Case study - Essay Example On its part, the media is used by the government to control the public. The public on the other hand has become obsessed to TV from which government publicity is generated. Some common events designed on media to gain publicity are in the form of planted, manufactured or non-spontaneous news. Some practices in public relations are timeless like the carrying of a bible as a prop particularly in enhancing the seeming worthiness of a leader. The true application of public relations as self-conscious managing art and occupation was through the 20th century ideas of Bernays aimed at influencing the opinion of the public on commodities through the use of psychology. This strategy worked for both Proctor & Gamble Ivory soap and American Tobacco Company through selective use of powerful symbols to correlate with the selling. Today, public relations practitioners seek to achieve an essential moment that representatively engraves in the mind of the public. The most recent defining moment was t he bombing of the world trade center in 9/11 involving Rudy Giuiani who survived the blast by escaping from debris. In conclusion, public relation is an inseparable part of management’s major decisions given that one has to consider the perception of the public on the decisions. Public relations are not without drawbacks since some use it to cover up for their misgivings which then call for the public to be keen in examining their public servants (case study

Renewable Energy Essay Example | Topics and Well Written Essays - 1000 words

Renewable Energy - Essay Example Hydropower has a significant role to play in the advancement of renewable energy around the globe, with a majority of nations relying on it to some extent in the generation of energy (Kaygusuz, 2009). This energy source is environment friendly and produces negligible greenhouse gases. In addition, a system is striking in its cost-effectiveness since it converts 95% of energy inherent in the moving water into electric energy. Compared to sources like fossil fuels, which produce 60% efficiency, the potential for hydroelectric power is enormous. Hydropower was first used by ancient generations for the driving of wheels to make work easier. Over generations, the energy source evolved and was finally utilized for the generation of electricity, with authorities being struck by its renewable nature. The energy source only utilized the flowing water’s energy to produce electricity without decimating the water supply. This was especially significance since the water sources were the lifeline of the populations living along them and down-stream to them (Kaygusuz, 2009). Its development was aided by human’s need to find an energy source that was not decimated over time. Most energy sources at the time were used in large quantities that were obviously not sustainable in the occurrence that technology either remained on its course, or increased to require more energy. The greenhouse gas emitting nature of fossil fuels is the other factor that greatly affected the development of this source. Hydropower showed excellent po tential in the cutting of these gases (Kaygusuz, 2009). Hydropower has come a long way to provide one fifth of the world’s power requirements (Kaygusuz, 2009). These projects were started in rural areas since estimates showed that the world’s rural population would grow by 95%. The highest demand was also forecasted to come from developing countries, which have been highly receptive of the energy. This was driven by the fact that the energy source was not liable to market fluctuations. Most governmental authorities around the world have turned to this energy source due to its combination of water management and its renewable nature. 2. Biomass Use as a Transitional Strategy for a Sustainable and Clean Energy System The greatest factor that made biogas desirable was its contribution to development that was desirable. Its attractiveness was further enhanced by low cost for conversion of resources into usable energy, as well as the availability of the resources, which was local. This made the energy source secure, thus desirable (Kaygusuz & Keles, 2009). Its usefulness in rehabilitation of degraded land via the use of exhausted resources as manure also led to most governmental

International and Non International Armed Conflict Essay

International and Non International Armed Conflict - Essay Example Humanity has witnessed wars since time immemorial and the ancient civilizations were observed as being particularly horrific in their conduct of war. However, the numerous conflicts of the relatively modern era are likely to cause many to question if any restrictions do exist to the behavior of parties involved in a conflict. In the present day and age, the law of war is known as the ‘international humanitarian law applicable in armed conflict’ or ‘humanitarian law’. International law has now evolved and attempted to prescribe rules that govern the resort to force and an attempt is also made to try to regulate the conduct of hostilities (Shaw, 2003, Pp. 1054 – 1055) and (Bouvier, 2006, Chapter 1). The law of war has been shaped by customary rules and conventional or codified rules. A long history of evolution is to be observed in the development of the law of armed conflict. Military leaders or those in political authority used to issue instructions a bout the treatment of civilians or enemy soldiers that tried to restrain excesses and these gradually developed into customary rules of war (Kalshoven, 2001, Pp. 15 – 17) and (Carrillo Salcedo, 2005, Chapter 1). However, the scope and the content of the customary rules of war had generally remained elusive and uncertain. The development of the law of war as treaty law can be traced back to the early 1860s when international conferences at The Hague and Geneva resulted in international treaties related to humanitarian aspects of armed conflicts.

Embracing Technological Change Essay Example for Free

Embracing Technological Change Essay To what extent is embracing technological change the most significant factor in the future success of UK manufacturing businesses? Justify your answer with reference to your own research and the item above. (40 marks) Technology is the application of scientific knowledge for practical purposes, especially in industry. It can be argued that skills and other factors are considerably more important than technological change, for the future success of UK manufacturing businesses. Yet I disagree, I view technological change to be the most significant. In this essay, I am going to talk about several companies in which technology is vital. Firstly, within the Food sectors, technology is absolutely essential. This is due to the need to adapt, not only to changes in demand, but from a business perspective too. As in the food sector, technology allows for food manufacturers to lower costs, by having machinery doing menial tasks such as filling cans or producing such items such as Walkers Crisps. Walkers factory in Leicester is amongst the largest crisp production plants in the world, producing over 11 million bags of crisps per day and using 800 tons of potatoes. This process mostly uses machinery to cook, flavour and package the crisps, as humans would not be able to withstand the amount of work needed to fulfil the demand. Technology has allowed Walkers to move from hand-sliced and fried potatoes in the 1880s, to mass machinery production. This shows that technology has allowed them to produce new products, and with this change has provided investment allowing the business to further grow into a market leader. It is not only within the production of food stuffs that technology has changed businesses, but in selling the goods too, as Tesco and Asda, have also implemented technology into their processes. The large supermarkets use technology to implement processes such as lean production, which encompasses the â€Å"Just In Time† technique. Tescos have been able to use this so that storage isnt used up with unnecessary goods, as when an item is scanned at the checkout, it then logs into the computer, and when that item is low on stock, then an order is sent directly to the warehouse or supplier. This technique means that there is no wastage of stock, and reduces time wastage too as the manager doesnt need to assess the remaining stock throughout the day. Also, as robots are becoming cheaper  and slowly more advanced, it has seen the sales of them go up by 28% in 2013 in the food sector, once again showing how technology plays a large part in UK manufacturing. However, in contrast, technology isnt vital for Crockett Jones of Northampton. This shoe company was founded in 1879. It began with 20 employees hand cutting and tanning leather. As technology developed, the company did begin to use it, yet only on the smallest of tasks, in order to not lose the significance of the hand quality goods which they gained their reputation for. Despite not using a lot of technology, they still have implemented some, which shows again how important technological change is to UK manufacturing. Yet in the automotive sector, technology is viewed to be vital, as it allows from quality and precision to be improved greatly. This is shown in the case of Jaguar Land Rover, where they produce premium cars that provide excellent quality, whilst being assembled quickly. This has been successful due to the implementation of robotics and automation, whilst also reducing the costs of production too. The costs are reduced, because the business is seen to be more efficient due to the greater amounts of precision and lack of human error, which in turn reduces wastage. Another point as to why technology is significant in the automotive sector is that these advancements allow for each customer to have the exact car they want in the exact specification. For example, robotics for painting to be quicker, allowing for change to happen in the shortest possible time, again reducing time wastage. With this reducing costs, it means that these increased levels in profits can lead to future product development, such as giving more investment to RD to become more innovative, thus gaining a competitive advantage. The RD may lead to investments into such technologies as Green Technology, which encompasses a continuously evolving group o methods and materials, from techniques for generating energy to non-toxic cleaning products, thus allowing products to be more sustainable. By doing this it allows for companies to meet the needs of society, which can continue into the future without damaging or depleting natural resources. Already, green technology is playing a massive part in Uk manufacturing, with the  £60bn a year industry managing to save nearly  180,000 tonnes of CO2 in 2012. Toyota are leading the way for Green Technology in the UK, with their production plant situated in Wales. They produce the Prius, which, has near to zero emissions, which offers incentives from the government, such as lower road tax. Green Technologies have broadened the visionary design of the car of tomorrow, which if the UK wish to be market leaders, with a large customer base then they should further implement this technology available to them. The BMW i3 is a key example of this, as it is emissions free, and acts as a USP, heightening BMW’s success and allowing them to be market leaders. In contrast, companies such as Rolls Royce, pride themselves on quality, bespoke, hand-made vehicles. Despite being the only car manufacturer in the FTSE100, they invest 7.53% of their revenue in RD, yet they do not pride themselves on technology being needed as a USP. As it is said that each car produce by them is individual, as it is hand made, by well-trained craftsmen. Their premium price shows the prestige that they portray, and the amount of skill put into the cars. So this shows that Rolls Royce customers value quality above technology when they buy this car, which has lead to the business becoming so successful. On the other hand, in some sectors of UK manufacturing embracing technological change is not the most significant factor in the future success of UK manufacturing, as skills are required to incorporate the technology into the business. Skills may also be considered to be more important as they allow for quality and premium prices to be associated with some products. For example, I M Kelly, has become the centre of excellence for automotive interior leather trim within the United Kingdom, whilst also diversifying into Rail and Passenger Aircraft industries. The company was established in 1975 and its head office and main production facility is situated in Northamptonshire, a figure point for high quality leather. The company also has a second production facility on the outskirts of Coventry, which thus allows it to be closer to the centre of the UK allowing for easier transport and delivery to such automotive manufactures as Jaguar Land Rover, Bentley, Aston Martin and Lotus. These prestigious, premium brands illustrate the quality that I M Kelly produce, due to the high level of  skills from their employees. These skills are used in tandem with the up-to-date technology, allowing them to produce outstanding quality, and exceed their customer’s expectations. Due to the type of leather work carried out here, means that robots or machines cant sew small intricate stitches into the gear sticks, or along the steering wheel, again showing where skills are beneficial. The UK government have also seen to play an active role in promoting how important skills are, with David Cameron giving â€Å"fast-track’ visas to technology experts from outside of the UK. Whilst other businesses have called for increased investment into the education of scientists and engineers in schools, such as the Jaguar Land Rover apprenticeship scheme. Yet there are many sectors that do not require skills to be too important, meaning that skills are not vital for every co mpany. In conclusion, in the short term, it is arguable that skills are of utmost importance in progressing the future development of UK manufacturing, as it allows for the technology to be created and implemented. Shown by David Cameron being keen to fast track technology experts. Yet that statement also shows that the experts are needed for the technology only, so in the long term technology will be more significant. As the world is continually using up more of the natural resources, and their being a greater need for the reduction of wastage and emissions, it is clear that technology is the only way to achieve this. As it was due to old technologies that this â€Å"mess† occurred in the first place. Therefore by using technology to become innovative, to reduce costs and attract more demand, it will lead to UK manufacturing businesses to be more successful. Which will allow for manufacturing sectors to become world market leaders.

Porters Five Forces Analysis Of Aviation Sector Engineering Essay

Porters Five Forces Analysis Of Aviation Sector Engineering Essay Barriers to Entry The aviation sector is one of the most expensive and extremely risky sectors due to high capital costs. These costs include buying and leasing aircrafts, fuel, safety and security measures, labor, customer service, etc. The increasing fuel costs have affected the airline industry adversely as it has a direct impact on the operating costs. A weakening economy also affects the airline revenues as the demand for air travel and air freight reduces and business and leisure travelers become highly price sensitive. UAE restricts complete foreign ownership of a company. All the companies are supposed to have at least one or more national partners who account for at least 51% of their capital. Therefore, the existence of high start-up costs and other barriers discourages new competitors from easily entering this industry. http://www.mlive.com/business/west-michigan/index.ssf/2011/02/rising_jet_fuel_costs_affectin.html http://www.investopedia.com/features/industryhandbook/airline.asp Competitive Rivalry The rivalry existing in the UAE aviation industry is intense since there are over 110 airlines currently flying to more than 160 destinations from Dubai International Airport itself. Since Dubai is located in a very strategic location and it is the business capital of the Middle East, the aviation industry showed a very strong growth in the last decade. All the carriers are constantly struggling to steal the market share from each other. Each airline is trying to have competitive prices and is working on lowering its operational costs to increase efficiency and profitability. This has lead to saturation in the market and airlines have to compete to survive in the UAE airline industry. http://www.dubai.ae/en.portal?vstrs_arrv_dxb,vstrs_arive_air,1,HYPERLINK http://www.dubai.ae/en.portal?vstrs_arrv_dxb,vstrs_arive_air,1,_nfpb=true_pageLabel=lifeEventDetail HYPERLINK http://www.dubai.ae/en.portal?vstrs_arrv_dxb,vstrs_arive_air,1,_nfpb=true_pageLabel=lifeEventDetail _nfpb=trueHYPERLINK http://www.dubai.ae/en.portal?vstrs_arrv_dxb,vstrs_arive_air,1,_nfpb=true_pageLabel=lifeEventDetail HYPERLINK http://www.dubai.ae/en.portal?vstrs_arrv_dxb,vstrs_arive_air,1,_nfpb=true_pageLabel=lifeEventDetail _pageLabel=lifeEventDetail http://www.zawya.com/story.cfm/sidZAWYA20101229042209/ ae/%20carriers%20see%20brighter%20sky%20ahead Supplier power Irrespective of UAE aviation industry or the world aviation industry there are only 2 main suppliers, Boeing and Airbus. Fly Europe has a fleet of Boeing aircrafts and their supplier, Boeing, has a high bargaining power as there is no cut throat competition in the supplier industry. The switching costs from Boeing to Airbus is also extremely high because all the pilots and mechanics have to be trained to learn to operate the different kind of aircrafts. However, other suppliers of Fly Europe like the providers of on-board snacks for the travelers (who are willing to purchase them) dont have high bargaining power since there are many other options available in the market. Fly Europe can purchase their snacks from some other cost-effective supplier as this would enable the customers to buy the snacks at reasonable prices. http://www.investopedia.com/features/industryhandbook/airline.asp Customer power Air travel is expensive, so most of the leisure travelers have highly elastic demand. They can compare prices of different airlines easily over the internet as they have many different options while choosing an airline carrier. Business travelers pay a much higher average ticket price, approximately five times more than the average leisure ticket cost. Hence, the bargaining power of business travelers in the aviation sector is quite high since as they generate most of the revenues of the airline while the bargaining power of leisure passengers is low. www.csus.edu/indiv/h/hany/Teaching//Lecture2_han.ppt http://www.wikinvest.com/concept/Airline_Travel Availability of substitutes Airline is the fastest way to travel from one destination to another so there is no perfect substitute available. The other transportation options available to the customers are trains, cars, etc. The choice of the mode of transportation depends on the length of the route, consumer preferences, etc. For example air travel isnt practical and economical for short distances. High-speed video conferencing is emerging as an important substitute to air travel for business travelers as it provides a convenient, safer, time-saving and cost-effective to conduct important meetings. Reducing travel time results in employee productivity, effectiveness, decrease in stress and hassle, etc. The emergency air freight market is also getting affected as these days, urgent documents are sent through the e-mail which is a cheap and faster alternative. While, Sea freight is considered an economical and practical way to send bulky items which is affecting the routine air freight market. Therefore, many c ompanies are using these technologies to replace airline travel and freight. http://www.businesseconomics.in/?p=638 http://www.investopedia.com/features/industryhandbook/airline.asp Industry description The aviation industry in the United Arab Emirates plays an essential part in its economy. It is one of the fastest growing aviation industries in the world. The General Civil Aviation Authority (GCAA), headquartered in Abu Dhabi, regulates civil aviation in the UAE. Foreign ownership and control of airlines in the UAE is restricted to a 49% equity stake. But in 2009, UAE signed an air liberalization policy statement with six other countries and the European Commission. The policy principles focuses on three main issues : freedom to access capital markets, freedom to do business, and freedom to price services. UAEs aviation industry earned a profit of $15 billion profit in 2010. The air traffic movements grew at the rate of 13 .8% in November 2010 compared to November 2009. This sector is expected to be the 2nd largest aviation market with the growth rate of 10.2% in 2013. According to the forecasts, the UAE will have 82.3 million air travelers and will be handling 2.7 million tons by 2014. Dubai has become a major hub of aerospace both in the middle east as well as on a global level as traditional players like the USA and Europe continue to slump. http://www.arabianbusiness.com/uae-passenger-traffic-hit-82-3m-by-2014-says-iata-380800.html http://www.uaeinteract.com/docs/UAE_aviation_market_will_be_second-fastest_growing_by_2013/44449.htm http://www.dancewithshadows.com/flights/dubai-aviation.asp http://www.scoop.co.nz/stories/BU1012/S00286/10-more-liberalised-aviation-agreements-for-emirates-in-2010.htm http://www.emirates.com/mv/English/about/public_affairs/liberalisation.aspx http://www.zawya.com/story.cfm/sidZAWYA20101229042209 /ae/%20carriers%20see%20brighter%20sky%20ahead http://www.gcaa.gov.ae/en/pages/welcomegcaa.aspx http://english.alrroya.com/content/uae-signs-air-liberalisation-policy-statement-iata Economic conditions The United Arab Emirates (UAE) is one of the fastest growing economies in the world. It is the 2nd largest economy in the Middle East after Saudi Arabia. It is also a major player in the world energy markets as it has the 6th largest crude oil reserves and natural gas reserves. UAE is taking extensive measures to reduce its reliance on these natural resources as an income source and is diversifying its economy by investing in growing sectors like trade, finance, aerospace, tourism, etc. The global financial crisis slowed down the GDP growth in 2010. UAE authorities responded to this crisis by injecting $33 billion into the local financial sector and guaranteeing all deposits in international and local banks. Dubai was hit very badly by the recession as its real estate sector experienced a major downturn and it couldnt meet its debt obligations. The central bank of UAE then provided support to the local banks while Dubai received a loan of $ 10 billion from Abu Dhabi to ease the debt crisis. However, the economy is expected to rebound in 2011. The non-hydrocarbons economy is expected to grow 2.2% in the year 2011. The oil prices averaged $79.6/barrel in 2010 are forecasted to rise to $90 billion in 2011. The GDP growth rate is expected to increase from 2.2% in 2010 to 3.3% in 2011. The government also plans to carry out large infrastructure projects which is supposed to result in a gradual recovery of the real estate sector. http://www.propertyselect.com/dubai/news/what-impact-will-the-global-recession-have-on-dubai-property/1442 http://www.davisiaj.org/?p=210 http://www.uaeinteract.com/docs/UAE_non-oil_economy_to_rebound_in_2011-2012/41839.htm http://www.english.globalarabnetwork.com/201101018483/Economics/uae-economy-gdp-rebounds-around-33-in-2011.html https://www.cia.gov/library/publications/the-world-factbook/geos/ae.html http://en.wikipedia.org/wiki/Economy_of_the_United_Arab_Emirates#cite_note-1 http://www.dfat.gov.au/geo/uae/uae_country_brief.html http://www.zawya.com/marketing.cfm?zpHYPERLINK http://www.zawya.com/marketing.cfm?zpp=/countries/ae/macrowatch.cfm?eiusection=Country OutlookccHYPERLINK http://www.zawya.com/marketing.cfm?zpp=/countries/ae/macrowatch.cfm?eiusection=Country Outlookccp=/countries/ae/macrowatch.cfm?eiusection=Country%20OutlookHYPERLINK http://www.zawya.com/marketing.cfm?zpp=/countries/ae/macrowatch.cfm?eiusection=Country OutlookccHYPERLINK http://www.zawya.com/marketing.cfm?zpp=/countries/ae/macrowatch.cfm?eiusection=Country Outlookcccc

Water Mist Replacement for Halon Extinguishers

Water Mist Replacement for Halon Extinguishers CHAPTER ONE: 1.1: Introduction Choosing the best fire suppression technology is not an easy task. It even involves discussing risks and operations with insurance companies. The most relevant concern of a fire safety engineer is the protection of life which entails the safe evacuation of personnel. The starting point of a suppression system is a risk analysis to reduce the potential occurrence of a fire. This is followed by the control of the damage and the recovery effort or emergency response associated with the means of fire suppression adopted. The quality of installation, efficiency and maintenance of the suppression system adopted cannot be over-emphasised. The phase out of halons, due to environmental concerns, has lead to forceful development of new fire prevention strategies and technologies that are efficient, as well as environmentally friendly technologies. Fire protection halons were phased out of production in developing countries due to the quest to regulate the use of ozone depleting substances(ODS) as reflected in the Montreal Protocol,1987(London Amendment 1990, and Copenhagen amendment1992). Fire suppression agents have two (2) toxicological aspects to them: The toxicity of the agent The toxicity of combustion products of the agent. Several new fire suppression systems have been developed such as inert and halocarbon gaseous systems, water mist systems, gas and aerosol generators. Fire has been extinguished with water since ancient times. Water in the normal form is not a suitable suppression medium of all classes of fire. The efficiency of water in suppression is enhanced by its use of water in form of mists. Survey by Mawhinney and Richardson in 1996 showed that about 50 agencies worldwide are involved in the research and development of water fire mist and suppression systems. Water mist in fire suppression does not behave like true gaseous agents and is affected by fire size, the degree of obstruction, ceiling and the ventilation conditions of the compartment. To effectively suppress a fire, a water mist system must generate and deliver optimum sized droplets with an adequate. 1.2: Objectives and Structure of Dissertation This project aims at studying the water mist as a replacement for halons systems in the extinguishment of fires. This replacement is a direct consequence of the phase out of halons due to environmental issues and the need to find a drop-in replacement or a suitable alternative in areas where high level of fire safety is required and the cost of fatalities is too high. Chapter 2 2.1: Overview of Fire Suppression To suppress fires, the type of fire needs to be identified. The class of the fire to be extinguished also determines the type of extinguisher that can be used. There are six (6) types of fires: Class A FIRES: These involve flammable or combustible solids such as wood, rubber, fabric, paper and some plastics. Class B FIRES: These are fires involving flammable and combustible liquids or liquefiable solids such as oil, alcohol, petrol, paint and liquefiable waxes.[9] Class C FIRES: These are fires involving flammable gases such as natural gas, hydrogen, propane, butane.[9] Class D FIRES: These are fires involving combustible metals, such as sodium and potassium.[9] Class E FIRES: These are fires involving any of the materials found in Class A and B fires, but including electrical appliances, wiring, or other electrically energized objects in the vicinity of the fire, with a resultant electrical shock risk if a conductive agent is used to control the fire.[9] http://www.sqa.org.uk/e-learning/FirstLineO2CD/page_06.htm Class F FIRES: These fires involve cooking fats and oils, especially in industrial kitchens. The temperature of these fats and oil on fire is much greater than that of other flammable liquids. 2.2: Means of Fire Suppression The aim of fire suppression is to provide cooling, control the spread of the fire as well as extinguish the fire. The behaviour of a fire is charcterised by the fire triangle which has fuel, oxygen and heat as its three sides. Combustion process is represented by: Fuel + O2 HEAT H2O + CO2 †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.eqn2.1 The combustion process is an exothermic reaction, involving a fuel and oxygen. The ratio of fuel to air must be within the flammability limits of the fuel for combustion to occur. The Lower Flammability Limit (LFL) is the minimum concentration of fuel vapour in air, below which a flame cannot be supported in the presence of an ignition source. The Upper Flammability Level (UFL) is the maximum concentration of fuel vapour in air, above which a flame cannot be supported. Stoichiometric Mixture is the ratio of fuel in oxygen that requires minimal energy to support a flame. A branch of the triangle must be removed for the fire to be extinguished. Fires can either be smoldering or flaming combustion. Smoldering occurs when solids such as wood or plastics burn at or on the surface. It usually involves the release of toxic gases and can be difficult to extinguish. Flaming combustion is a gas phase phenomenon that involves the release of visible and infrared radiation. This type of fire generates much more heat. The extinguishing of a fire involves either chemical or physical mechanisms. Physical mechanism: Involves the removal of one side of the fire triangle. This can be done by either blanketing the fire (causing the fuel and air to be separated) or by removing the heat source using an agent with a high heat capacity/ latent heat of vaporization (this will cool the flame by absorbing the heat). Physical mechanism could be thermal or dilution. Thermal physical effect involves adding non-reactive gas to a fire plume leading to a reduction in the flame temperature. This is achieved by the distribution of the heat generated to a larger heat area. The heat capacity of the introduced agent determines the efficiency of the process. On the other hand, for dilution physical effect, the collision frequency of oxygen molecules with the fuel is lowered when the additional gas is introduced into the fuel-air mixture. This effect is quite minimal and negligible. Chemical mechanism: This is the use of an extinguishing agent or its degradation product to disrupt the chain reaction for sustaining combustion. This entails inhibition by halogen atoms. Most good suppressants apply both the physical and the chemical mechanisms. The type of hazard associated with an area determines the fire protection system that will be put in place. Halons have been used in a wide range of applications. Other alternatives include: Water Sprinkler Systems: This is a very common type of fixed protection that offers safe protection to limit structural damage. The cost of installing water sprinkler systems into existing structures is quite expensive. They are better at protecting structures than its contents [11]. The reliability of water sprinkler system has encouraged its wide use. Accidental discharge is uncommon with water sprinkler systems. Water sprinklers have a much slower response than other systems. They also cause a considerable secondary damage. They cannot be used on live electrical equipment and flammable liquids, but they are used widely in computer and control rooms as well as storage rooms in the USA. Detectors: This involves the use of high sensitive smoke detection. This is not exactly an active fire protection approach but it serves as an initiator to other fire protection systems [2]. Carbon dioxide: Carbon dioxide is widely used in gaseous based fire extinguishing systems. There are two types of carbon dioxide system depending on the manner by which they are stored. These are high pressure and low pressure carbon dioxide systems. It is a clean agent and has a good penetrating ability. This makes it safe for use on live electrical equipment. They are also used in unoccupied spaces such as computer and control rooms. Carbon dioxide causes very minimal direct or secondary damage and allows the installation being put back to immediate use after a fire. It is however toxic and cannot be used in total flooding situations. Carbon dioxide cannot also be used in situations where weight and space are important. High concentrations of carbon dioxide are required for extinguishment and as such they are bulky and heavy. They cannot be used in manned areas because they reduce the oxygen concentration to levels below life support and thus cannot be set in automatic mode. Carbon dioxide systems are generally fast acting and cost effective. Carbon dioxide has also found use in record storage, flammable liquid fires, chemical processing equipment, turbine generators, marine applications, computer rooms and shipboard machinery. Inert Gases: inert gases in use for fire suppression are majorly argon and nitrogen mixtures. These are electrically non-conductive fire suppressants. The mechanism behind their use is the lowering of the oxygen concentration of air to that below the lower flammability point (LFL). They are not liquefied gases and they are bulky because they are stored at high pressure. The concentration of inert gases released in the hazardous area is high because they have densities that are similar to that of air. Their response time is not very fast and so they are not efficient in situations where the rate of fire spread is high. Inert gases do not decompose thermally and thus they form no breakdown products [2]. Inert gases can cause an extreme decrease in the composition of oxygen in the body accompanied by an increase in the concentration of carbon dioxide leading to loss of consciousness or death and as such health and safety issues have to be considered in its use. Inert gases have found wi de acceptance because they pose no environmental problems. They are not ozone depleting substances neither do they contribute to global warming. They are employed in computer and control rooms, record storage, flammable liquid fires and shipboard machinery [2]. Halocarbon Gases: These are hydrofluorocarbons and perfluorocarbons with zero ozone depleting potentials. They are however greenhouse gases and are governed by the Kyoto protocol and hence its release counts towards the national emissions inventory of global warming gases. Halocarbons are electrically non-conductive, are clean agents and are not bulky in terms of space and weight. Foam Systems: Foam systems could be low, medium or high expansion systems. Foam systems are efficient for extinguishing liquid pool fires and large cable fires. In this case, the foam acts as a barrier between the fire and the supply of oxygen. The use of chemical dispersants to clean up after its use has limited the wide use of foam systems. Furthermore the use of smoke detectors for its activation limits its speed of response. They cannot be used to protect any substance that reacts violently with water. Foams systems are often used with water sprinklers. This increases the efficiency of the systems. Foam systems have found use in the extinguishment of flammable liquid fires, engine compartments and shipboard machinery. Dry Powder: Powders have very high response time for extinguishing fires but have no cooling effect. They thus become ineffective as soon as it settles [2]. They are limited in application to extinguishing flammable liquid fires as well as engine spaces. Fine Solid Particulates: This system is used in combination with halocarbon gases and inert gases [2]. They have the advantage of reduced wall and surface losses relative to water mist and particle size is easier to control[2]. They however pose problems to sensitive equipment and cannot be used for explosion suppression applications because they are generated at high temperatures. Fine solid particulates can only be used in unmanned areas because of the problems associated with inhalation of particulate substances. Water Mist: This employs the use of fine water sprays, usually less than 100 microns in diameter. Water mists can be used on flammable liquid fires, as well as electrical equipment. They are not as effective on small or slow burning fires. Water mist installations pose problems in their design and fabrication. Hybrid Systems: Hybrid systems combine one or more of the above fire protection system. A common example of this is the combination of water mist systems and carbon dioxide. There are two methods of applying fire extinguishing agents-Total Flooding and Local Application. Total Flooding: They are operated automatically and manually. It entails applying an extinguishing agent to an enclosed space to achieve a concentration of the extinguisher that is capable of putting out the fire. This method is the most common system of application Local Application: The agent is applied directly onto the fire plume or the affected enclosure. Portable fire extinguishers are the most common forms of this approach. This method is also known as streaming application. There is an increase in the need for the phasing out of halons and this has brought the search for the perfect or drop-in replacement. The department of trade and industry in 1995 listed checklists for the selection of alternatives to halons in critical uses situations as: Fire fighting effectiveness: This involves the speed of fire suppression, the post fire hold time, the ability of the alternative to permeate, the elimination of the risk of reignition, the suitability of the alternative to the fire hazard. Ease of Installation: Ease of maintenance, pipe work, and cost of installation, cost of refill, floor space and weight, system re-instate time, and availability of the extinguisher. Hazards to occupants: Toxicity, noise levels, pressurisation, inhalation, visibility, safety as regards electrical work, thermal decomposition products [2]. Discharge effect on equipment: water damage, clean up, corrosion, thermal shock. Environmental acceptability: Ozone depletion potential, atmospheric lifetime, and global warming potential. Discharge damage: This entails clean up of the agent after use, water damage, thermal shock and corrosion. Esso Australia, while looking for alternatives to halons on their installations considered the following issues [14]: Effectiveness at extinguishing fires Environmental effects (a zero ozone depleting and global warming potential) of the agent before use and after thermal decomposition. Toxicity level and a safety margin between its No Observed Adverse Effects Level (NOAEL value) and the extinguishing concentration required Third party approval from regulatory bodies and safety partners such as International Maritime Organisation (IMO), NFPA, and EPA or Underwriters laboratory Organisations. Level of engineering required to modify an existing halon protected installations. Availability as regards to installation and maintenance at a reasonable cost. 2.2: Health and Safety Issues Considering the health and safety in the UK, there is no specific regulation as regards choice of fire extinguishing systems. Otherwise fire risks and risk from the use of extinguishment can be categorised under risks at work. The Management of Health and Safety at Work Regulations 1992 stipulates all risks at work are to be assessed and prevented where ever it is reasonably practicable, controlled. In cases where fire extinguishing systems contain toxic substances then the Control of Substances Hazardous to Health Regulations 1988 (COSHH regs) will also apply. The basis of the two regulations is the prevention rather than control of the risk. 2.3: Environmental regulations The International Maritime Organisation (IMO) has prohibited the use of new halon systems from 1994, but accepts the use of existing ones. The EU has banned its use onboard vessels by the end of 2003. The following are regulations that are put in place to phase out the use of halons. The Montreal protocol on Substances that Deplete the Ozone layer- the Montreal protocol, signed by 25 countries on the 16th of September, 1987 is an international treaty for the control of the production and use of ozone depleting substances. It involves the restriction and eventual prohibition of the production, distribution and use of Ozone Depleting Substances. A copy of this document is attached in Appendix 1. The EC regulations: This European legislation was put in place to further tighten the restriction on the ban of ozone depleting substances. EC Regulation 3093/94 came into force on the 23rd of December 1994. EC Regulation 3093/94 is directly binding in all EU Member States and does not require any national implementing legislation. The new Regulation EC 2037/2000 came into force on 1 October 2000, replacing the Regulation 3093/94. The enforcement requires the use of bodies such as the HM Customs and Excise concerning import of controlled substances. The Department of the Environment proposes to implement these arrangements through enforcement regulations made under both the Environmental Protection Act 1990 s.140 and the European Communities Act 1972.(EC REGULATION) The new requirements are applicable to the production, distribution, use and recovery, and control of hazardous substances. The regulations also require the recovery of used controlled substances from certain equipment, s uch as fire protection systems, for disposal or recycling, during servicing and maintenance procedures of equipment. A copy of the regulation is attached to Appendix 2. The Victorian Environment Protection Legislation for the Control of Ozone Depleting substances (Victorian Government Gazette No.S57, 1990) this piece of legislation depicts the Australian governments compliance, reliance and advocacy to the implementation of the Montreal protocol on the phasing out of halon use [14]. Environmental Protection agency: Under the Clean Air Amendment, the United States Environmental Protection agency, EPA analysed various substances that could substitute fire extinguishing agents that destroy the ozone layer. These substances also have low global warming potential and low Atmospheric lifetime. The SNAP program (Significant New Alternatives Policy) is used by the EPA to replace the use of halons with environmentally friendly systems in the United States. The Clean Air Act was signed into law in 1990. With this Act, the US banned the production and import of new halons 1211, 1301 and 2402 from the 1st of January 1994 in compliance with the Montreal Protocol. The US government also imposed excise tax on halons through specialized training and proper recycling and disposal. Chapter Three: Halon Systems Halon is the generic name for bromine contained halogenated hydrocarbons. Halons systems were first installed in the late 1960s and early 1970s. In the gaseous form, halons are excellent fire extinguishers. Halons are mostly employed in situations where fire safety standards are high. Halons are identified by a four digit number. The numbering system is assigned by the number of carbon, number of fluorine, chlorine and bromine atoms respectively. Halon 1301, containing carbon, fluorine and bromine is used in total flooding applications while halon 1211, containing carbon, fluorine, chlorine and bromine is used as hand held portable extinguishers. The two common halon types described are effective in extinguishing classes A, B and C fires. These halons are preferred because they exhibited: high efficiency in suffocating combustion, availability in volume at reasonable cost, high storage stability, low electrical conductivity, as well as acceptable toxic properties. 3.1: Characteristics of Halons Halons interfere with the chemical reactions which take place during a fire. The properties of halons allow for its use in most situations and thus most of its applications are linked to particular characteristics. These principal applications include: Clean fire fighting agent: Halons leave no residue after use. This eliminates secondary damages and keeping loss caused by the fire to a minimum [12]. Electrically non-conductive: This property makes it suitable for safe application on fires involving electrical equipment. It will prevent exposure of fire fighters to electric shock. Low toxicity: This property makes halons acceptable and in most cases halon flooding systems are set in automatic mode by default. They can also be used to extinguish fires while people are present in the protected room. Halon flooding systems do not displace so much oxygen which can lead to suffocation[12] Rapid response: Halons are effective for rapid knockdown of flames. This property is mostly essential for class B fires involving liquid and liquefiable solids. Low concentration requirement: This means low quantity or amount of halons are required for extinguishment. It minimizes weight and space allowance [12]. Gaseous state: This allows for good penetration and effective extinguishment in confined spaces. Boiling point: The boiling point of about -4 allows it to be discharged (in the case of hand-held extinguishers) as a liquid for a while before it vaporises. This is a key requirement in some manual fire fighting applications.[12] Low heat of vaporisation: Halons will not condense to form water or ice in halon flooding systems. The most important advantage of halons is in its cost effectiveness. Halon fixed systems are the most cost effective of all extinguishing systems. 3.2: Extinguishing Mechanisms of Halons Halons extinguish fires both chemically and physically. Chemically they interfere with the chemical reactions that take place during the fire. This characterises halons as inhibitors. Radicals released during combustion to keep the fire burning are suppressed chemically by halons. This reaction is anti-catalytic. When halons are heated during combustion, they produce free radicals which compete with those produced by the original combustion process [2]. Halon 1301 produces bromine radicals which react with hydrogen free radicals to produce hydrogen bromide. The hydrogen bromide then reacts with hydroxyl radical to form water and bromide. The bromide released reacts with the combustion fire again and the whole cycle is repeated. The hydrogen and hydroxyl free radicals produced by combustion are greatly reduced in concentration by combining with the halogen free radicals produced by halons [3]. Where RH is the combustible fuel, XBr is a halon agent RH + O2 ENERGY OH + R †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.eqn3.1 XBr ENERGY Br + X†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦eqn3.2 RH + Br HBr + R†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦eqn3.3 HBr + OH H2O + Br†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦eqn3.4 RH ENERGY R + H†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦eqn3.5 H + Br HBr†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦eqn3.6 The combination of bromine and hydroxyl radical is also an ozone destructive reaction: HOBr UV Br + OH†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦..eqn3.7 OH + O3 HO2 + O2..eqn3.8 Br + O3 BrO + O2†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦eqn3.9 BrO + HO2 HOBr + O2 †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦..eqn3.10 3.3: HALONS AND THE OZONE 3.3.1: The ozone layer The earth is enclosed by the atmosphere. This atmosphere is made up of a mixture of numerous gases in varying proportions. The atmosphere is further subdivided into three regions depending on temperature. These regions are: Mesosphere, Stratosphere and Troposphere. The word ozone is from a Greek word, ozein, for to smell. It is an allotropic form of oxygen having three atoms in each molecule. It is a pale blue, highly poisonous gas with a strong odour. [10] In its thickest part in the stratosphere, it is only a trace gas.. Ozone is highest in concentration, about 97%, in the stratosphere (15-60 kilometers above the Earths surface) where it absorbs the ultraviolet radiation from the sun. Ozone is also highly concentrated at the Earths surface in and around cities. The buildup of ozone on the earths surface in and around cities is a result of industrial activities and is toxic to organisms living at the Earths surface. Table 3.1 shows the percentage volume composition of the constituents of atmospheric air *variable gases http://www.physicalgeography.net/fundamentals/7a.html Ozone is very reactive and a stronger oxidising agent than oxygen. It is used in purifying water, sterilising air, and bleaching certain foods. Ozone is formed when an electric spark is passed through oxygen. Ozone is prepared commercially by passing cold, dry oxygen through a silent electrical discharge [7]. Ozone formed in the atmosphere is from nitrogen oxides and organic gases emitted by automobiles and industrial sources [7]. This is achieved by short wavelength ultraviolet. This is actually a health hazard, and it may cause crop damage in some regions. Ultraviolet wavelengths less than 200 nanometer reacts with oxygen molecules to make ozone. O2 UV O + O†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦eqn3.11 O + O2 O3 + Heat†¦Ã¢â‚¬ ¦.eqn3.12 The heat released here is absorbed by the atmosphere and results in a rise in temperature of the atmosphere. The structure of ozone has 3 oxygen atoms, but steric hindrance prevents it from forming a triangular structure, with each O atom forming the expected 2 bonds. Instead each atom of oxygen forms only 1 bond, with the remaining negative charge being spread throughout the molecule.[7] Ozone is very unstable. It is decomposed either by collision with monoatomic oxygen or by ultraviolet radiation on it. The decomposition causes ozone to form oxygen molecules. Heat is also released to the atmosphere by this reaction O + O3 O2 + O2†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.eqn3.13 O3 UV O2 + O + Heat†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.eqn3.14 Ozone is decomposed in the stratosphere to prevent highly energetic ultraviolet radiation from reaching the surface of the earth. 3.3.2: Halons and ozone depletion The ozone layer is mainly depleted by compounds containing chlorine and bromine. Halogens are a chemical family containing fluorine, chlorine, bromine and iodine; any carbon compound containing them is known as a halocarbon. While all halogens have the ability to catalyze ozone breakdown, they have an unequal impact on the ozone layer. The quantity of halons released into the atmosphere is small relative to the number of gases present in the atmosphere. Yet they are more active in destroying the ozone or disrupting the ozone balance for two reasons: Ozone is in a constant state of imbalance, as it is destroyed and produced by natural processes. This process is controlled by solar input that does not undergo significant fluctuations. The stability of halons makes it transportable from the troposphere to the stratosphere where halogens are made active and broken down very fast, destroying ozone in the stratosphere. . The impact is described as depletion potential of the halocarbon. The OZONE DEPLETING POTENTIAL (ODP) is a simple measure of its ability to destroy stratospheric ozone. The ODP of compounds are calculated with reference to the ODP of CFC-11, which is defined to be 1. Thus ODP is a relative measure. A compound withan ODP of 0.2 is, roughly speaking, one-fifth as bad as CFC-11. The ODP of a compound x is expressed mathematically as the ratio of the total amount of ozone destroyed by a fixed amount of compound x to the amount of ozone destroyed by the same mass of CFC-11[8]: Global loss of Ozone due to x ODP(x) == †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦..eqn3.15[8] Global loss of ozone due to CFC-11. The above expression depicts that the ODP of CFC-11 is 1.0 by definition. The uncertainties experienced in evaluating the global loss of ozone due to a compound are eliminated here since the mathematical expression is a ratio. Evaluating the ODP of a compound is affected by the following: The quantity of chlorine or bromine atoms in a molecule. The nature of the halogen, as bromine is a more ozone- destructive catalyst than chlorine. Atmospheric lifetime of the substance: The atmospheric lifetime of the halon is the time it takes for the global amount of the gas to decay to 36.8% of its original concentration after initial emission. Compounds with low atmospheric lifetimes have lower ODP because it is destroyed in the troposphere. Molecular mass of the substance: This is because ODP is evaluated by comparing equal masses and not number of moles. Table3.2 gives time-dependent and steady-state ODPs for some halocarbon in wide use. Compound Formula Ozone Depletion Potential 10yr 30yr 100yr Steady State CFC-113 CF2ClFCl2 0.56 0.62 0.78 1.10 Carbon tetrachloride CCl4 1.25 1.22 1.14 1.08 Methyl Chloroform CH3CCl3 0.75 0.32 0.15 0.12 HCFC-22 CHF2Cl 0.17 0.12 0.07 0.05 Halon-1301 CF3Br 10.4 Water Mist Replacement for Halon Extinguishers Water Mist Replacement for Halon Extinguishers CHAPTER ONE: 1.1: Introduction Choosing the best fire suppression technology is not an easy task. It even involves discussing risks and operations with insurance companies. The most relevant concern of a fire safety engineer is the protection of life which entails the safe evacuation of personnel. The starting point of a suppression system is a risk analysis to reduce the potential occurrence of a fire. This is followed by the control of the damage and the recovery effort or emergency response associated with the means of fire suppression adopted. The quality of installation, efficiency and maintenance of the suppression system adopted cannot be over-emphasised. The phase out of halons, due to environmental concerns, has lead to forceful development of new fire prevention strategies and technologies that are efficient, as well as environmentally friendly technologies. Fire protection halons were phased out of production in developing countries due to the quest to regulate the use of ozone depleting substances(ODS) as reflected in the Montreal Protocol,1987(London Amendment 1990, and Copenhagen amendment1992). Fire suppression agents have two (2) toxicological aspects to them: The toxicity of the agent The toxicity of combustion products of the agent. Several new fire suppression systems have been developed such as inert and halocarbon gaseous systems, water mist systems, gas and aerosol generators. Fire has been extinguished with water since ancient times. Water in the normal form is not a suitable suppression medium of all classes of fire. The efficiency of water in suppression is enhanced by its use of water in form of mists. Survey by Mawhinney and Richardson in 1996 showed that about 50 agencies worldwide are involved in the research and development of water fire mist and suppression systems. Water mist in fire suppression does not behave like true gaseous agents and is affected by fire size, the degree of obstruction, ceiling and the ventilation conditions of the compartment. To effectively suppress a fire, a water mist system must generate and deliver optimum sized droplets with an adequate. 1.2: Objectives and Structure of Dissertation This project aims at studying the water mist as a replacement for halons systems in the extinguishment of fires. This replacement is a direct consequence of the phase out of halons due to environmental issues and the need to find a drop-in replacement or a suitable alternative in areas where high level of fire safety is required and the cost of fatalities is too high. Chapter 2 2.1: Overview of Fire Suppression To suppress fires, the type of fire needs to be identified. The class of the fire to be extinguished also determines the type of extinguisher that can be used. There are six (6) types of fires: Class A FIRES: These involve flammable or combustible solids such as wood, rubber, fabric, paper and some plastics. Class B FIRES: These are fires involving flammable and combustible liquids or liquefiable solids such as oil, alcohol, petrol, paint and liquefiable waxes.[9] Class C FIRES: These are fires involving flammable gases such as natural gas, hydrogen, propane, butane.[9] Class D FIRES: These are fires involving combustible metals, such as sodium and potassium.[9] Class E FIRES: These are fires involving any of the materials found in Class A and B fires, but including electrical appliances, wiring, or other electrically energized objects in the vicinity of the fire, with a resultant electrical shock risk if a conductive agent is used to control the fire.[9] http://www.sqa.org.uk/e-learning/FirstLineO2CD/page_06.htm Class F FIRES: These fires involve cooking fats and oils, especially in industrial kitchens. The temperature of these fats and oil on fire is much greater than that of other flammable liquids. 2.2: Means of Fire Suppression The aim of fire suppression is to provide cooling, control the spread of the fire as well as extinguish the fire. The behaviour of a fire is charcterised by the fire triangle which has fuel, oxygen and heat as its three sides. Combustion process is represented by: Fuel + O2 HEAT H2O + CO2 †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.eqn2.1 The combustion process is an exothermic reaction, involving a fuel and oxygen. The ratio of fuel to air must be within the flammability limits of the fuel for combustion to occur. The Lower Flammability Limit (LFL) is the minimum concentration of fuel vapour in air, below which a flame cannot be supported in the presence of an ignition source. The Upper Flammability Level (UFL) is the maximum concentration of fuel vapour in air, above which a flame cannot be supported. Stoichiometric Mixture is the ratio of fuel in oxygen that requires minimal energy to support a flame. A branch of the triangle must be removed for the fire to be extinguished. Fires can either be smoldering or flaming combustion. Smoldering occurs when solids such as wood or plastics burn at or on the surface. It usually involves the release of toxic gases and can be difficult to extinguish. Flaming combustion is a gas phase phenomenon that involves the release of visible and infrared radiation. This type of fire generates much more heat. The extinguishing of a fire involves either chemical or physical mechanisms. Physical mechanism: Involves the removal of one side of the fire triangle. This can be done by either blanketing the fire (causing the fuel and air to be separated) or by removing the heat source using an agent with a high heat capacity/ latent heat of vaporization (this will cool the flame by absorbing the heat). Physical mechanism could be thermal or dilution. Thermal physical effect involves adding non-reactive gas to a fire plume leading to a reduction in the flame temperature. This is achieved by the distribution of the heat generated to a larger heat area. The heat capacity of the introduced agent determines the efficiency of the process. On the other hand, for dilution physical effect, the collision frequency of oxygen molecules with the fuel is lowered when the additional gas is introduced into the fuel-air mixture. This effect is quite minimal and negligible. Chemical mechanism: This is the use of an extinguishing agent or its degradation product to disrupt the chain reaction for sustaining combustion. This entails inhibition by halogen atoms. Most good suppressants apply both the physical and the chemical mechanisms. The type of hazard associated with an area determines the fire protection system that will be put in place. Halons have been used in a wide range of applications. Other alternatives include: Water Sprinkler Systems: This is a very common type of fixed protection that offers safe protection to limit structural damage. The cost of installing water sprinkler systems into existing structures is quite expensive. They are better at protecting structures than its contents [11]. The reliability of water sprinkler system has encouraged its wide use. Accidental discharge is uncommon with water sprinkler systems. Water sprinklers have a much slower response than other systems. They also cause a considerable secondary damage. They cannot be used on live electrical equipment and flammable liquids, but they are used widely in computer and control rooms as well as storage rooms in the USA. Detectors: This involves the use of high sensitive smoke detection. This is not exactly an active fire protection approach but it serves as an initiator to other fire protection systems [2]. Carbon dioxide: Carbon dioxide is widely used in gaseous based fire extinguishing systems. There are two types of carbon dioxide system depending on the manner by which they are stored. These are high pressure and low pressure carbon dioxide systems. It is a clean agent and has a good penetrating ability. This makes it safe for use on live electrical equipment. They are also used in unoccupied spaces such as computer and control rooms. Carbon dioxide causes very minimal direct or secondary damage and allows the installation being put back to immediate use after a fire. It is however toxic and cannot be used in total flooding situations. Carbon dioxide cannot also be used in situations where weight and space are important. High concentrations of carbon dioxide are required for extinguishment and as such they are bulky and heavy. They cannot be used in manned areas because they reduce the oxygen concentration to levels below life support and thus cannot be set in automatic mode. Carbon dioxide systems are generally fast acting and cost effective. Carbon dioxide has also found use in record storage, flammable liquid fires, chemical processing equipment, turbine generators, marine applications, computer rooms and shipboard machinery. Inert Gases: inert gases in use for fire suppression are majorly argon and nitrogen mixtures. These are electrically non-conductive fire suppressants. The mechanism behind their use is the lowering of the oxygen concentration of air to that below the lower flammability point (LFL). They are not liquefied gases and they are bulky because they are stored at high pressure. The concentration of inert gases released in the hazardous area is high because they have densities that are similar to that of air. Their response time is not very fast and so they are not efficient in situations where the rate of fire spread is high. Inert gases do not decompose thermally and thus they form no breakdown products [2]. Inert gases can cause an extreme decrease in the composition of oxygen in the body accompanied by an increase in the concentration of carbon dioxide leading to loss of consciousness or death and as such health and safety issues have to be considered in its use. Inert gases have found wi de acceptance because they pose no environmental problems. They are not ozone depleting substances neither do they contribute to global warming. They are employed in computer and control rooms, record storage, flammable liquid fires and shipboard machinery [2]. Halocarbon Gases: These are hydrofluorocarbons and perfluorocarbons with zero ozone depleting potentials. They are however greenhouse gases and are governed by the Kyoto protocol and hence its release counts towards the national emissions inventory of global warming gases. Halocarbons are electrically non-conductive, are clean agents and are not bulky in terms of space and weight. Foam Systems: Foam systems could be low, medium or high expansion systems. Foam systems are efficient for extinguishing liquid pool fires and large cable fires. In this case, the foam acts as a barrier between the fire and the supply of oxygen. The use of chemical dispersants to clean up after its use has limited the wide use of foam systems. Furthermore the use of smoke detectors for its activation limits its speed of response. They cannot be used to protect any substance that reacts violently with water. Foams systems are often used with water sprinklers. This increases the efficiency of the systems. Foam systems have found use in the extinguishment of flammable liquid fires, engine compartments and shipboard machinery. Dry Powder: Powders have very high response time for extinguishing fires but have no cooling effect. They thus become ineffective as soon as it settles [2]. They are limited in application to extinguishing flammable liquid fires as well as engine spaces. Fine Solid Particulates: This system is used in combination with halocarbon gases and inert gases [2]. They have the advantage of reduced wall and surface losses relative to water mist and particle size is easier to control[2]. They however pose problems to sensitive equipment and cannot be used for explosion suppression applications because they are generated at high temperatures. Fine solid particulates can only be used in unmanned areas because of the problems associated with inhalation of particulate substances. Water Mist: This employs the use of fine water sprays, usually less than 100 microns in diameter. Water mists can be used on flammable liquid fires, as well as electrical equipment. They are not as effective on small or slow burning fires. Water mist installations pose problems in their design and fabrication. Hybrid Systems: Hybrid systems combine one or more of the above fire protection system. A common example of this is the combination of water mist systems and carbon dioxide. There are two methods of applying fire extinguishing agents-Total Flooding and Local Application. Total Flooding: They are operated automatically and manually. It entails applying an extinguishing agent to an enclosed space to achieve a concentration of the extinguisher that is capable of putting out the fire. This method is the most common system of application Local Application: The agent is applied directly onto the fire plume or the affected enclosure. Portable fire extinguishers are the most common forms of this approach. This method is also known as streaming application. There is an increase in the need for the phasing out of halons and this has brought the search for the perfect or drop-in replacement. The department of trade and industry in 1995 listed checklists for the selection of alternatives to halons in critical uses situations as: Fire fighting effectiveness: This involves the speed of fire suppression, the post fire hold time, the ability of the alternative to permeate, the elimination of the risk of reignition, the suitability of the alternative to the fire hazard. Ease of Installation: Ease of maintenance, pipe work, and cost of installation, cost of refill, floor space and weight, system re-instate time, and availability of the extinguisher. Hazards to occupants: Toxicity, noise levels, pressurisation, inhalation, visibility, safety as regards electrical work, thermal decomposition products [2]. Discharge effect on equipment: water damage, clean up, corrosion, thermal shock. Environmental acceptability: Ozone depletion potential, atmospheric lifetime, and global warming potential. Discharge damage: This entails clean up of the agent after use, water damage, thermal shock and corrosion. Esso Australia, while looking for alternatives to halons on their installations considered the following issues [14]: Effectiveness at extinguishing fires Environmental effects (a zero ozone depleting and global warming potential) of the agent before use and after thermal decomposition. Toxicity level and a safety margin between its No Observed Adverse Effects Level (NOAEL value) and the extinguishing concentration required Third party approval from regulatory bodies and safety partners such as International Maritime Organisation (IMO), NFPA, and EPA or Underwriters laboratory Organisations. Level of engineering required to modify an existing halon protected installations. Availability as regards to installation and maintenance at a reasonable cost. 2.2: Health and Safety Issues Considering the health and safety in the UK, there is no specific regulation as regards choice of fire extinguishing systems. Otherwise fire risks and risk from the use of extinguishment can be categorised under risks at work. The Management of Health and Safety at Work Regulations 1992 stipulates all risks at work are to be assessed and prevented where ever it is reasonably practicable, controlled. In cases where fire extinguishing systems contain toxic substances then the Control of Substances Hazardous to Health Regulations 1988 (COSHH regs) will also apply. The basis of the two regulations is the prevention rather than control of the risk. 2.3: Environmental regulations The International Maritime Organisation (IMO) has prohibited the use of new halon systems from 1994, but accepts the use of existing ones. The EU has banned its use onboard vessels by the end of 2003. The following are regulations that are put in place to phase out the use of halons. The Montreal protocol on Substances that Deplete the Ozone layer- the Montreal protocol, signed by 25 countries on the 16th of September, 1987 is an international treaty for the control of the production and use of ozone depleting substances. It involves the restriction and eventual prohibition of the production, distribution and use of Ozone Depleting Substances. A copy of this document is attached in Appendix 1. The EC regulations: This European legislation was put in place to further tighten the restriction on the ban of ozone depleting substances. EC Regulation 3093/94 came into force on the 23rd of December 1994. EC Regulation 3093/94 is directly binding in all EU Member States and does not require any national implementing legislation. The new Regulation EC 2037/2000 came into force on 1 October 2000, replacing the Regulation 3093/94. The enforcement requires the use of bodies such as the HM Customs and Excise concerning import of controlled substances. The Department of the Environment proposes to implement these arrangements through enforcement regulations made under both the Environmental Protection Act 1990 s.140 and the European Communities Act 1972.(EC REGULATION) The new requirements are applicable to the production, distribution, use and recovery, and control of hazardous substances. The regulations also require the recovery of used controlled substances from certain equipment, s uch as fire protection systems, for disposal or recycling, during servicing and maintenance procedures of equipment. A copy of the regulation is attached to Appendix 2. The Victorian Environment Protection Legislation for the Control of Ozone Depleting substances (Victorian Government Gazette No.S57, 1990) this piece of legislation depicts the Australian governments compliance, reliance and advocacy to the implementation of the Montreal protocol on the phasing out of halon use [14]. Environmental Protection agency: Under the Clean Air Amendment, the United States Environmental Protection agency, EPA analysed various substances that could substitute fire extinguishing agents that destroy the ozone layer. These substances also have low global warming potential and low Atmospheric lifetime. The SNAP program (Significant New Alternatives Policy) is used by the EPA to replace the use of halons with environmentally friendly systems in the United States. The Clean Air Act was signed into law in 1990. With this Act, the US banned the production and import of new halons 1211, 1301 and 2402 from the 1st of January 1994 in compliance with the Montreal Protocol. The US government also imposed excise tax on halons through specialized training and proper recycling and disposal. Chapter Three: Halon Systems Halon is the generic name for bromine contained halogenated hydrocarbons. Halons systems were first installed in the late 1960s and early 1970s. In the gaseous form, halons are excellent fire extinguishers. Halons are mostly employed in situations where fire safety standards are high. Halons are identified by a four digit number. The numbering system is assigned by the number of carbon, number of fluorine, chlorine and bromine atoms respectively. Halon 1301, containing carbon, fluorine and bromine is used in total flooding applications while halon 1211, containing carbon, fluorine, chlorine and bromine is used as hand held portable extinguishers. The two common halon types described are effective in extinguishing classes A, B and C fires. These halons are preferred because they exhibited: high efficiency in suffocating combustion, availability in volume at reasonable cost, high storage stability, low electrical conductivity, as well as acceptable toxic properties. 3.1: Characteristics of Halons Halons interfere with the chemical reactions which take place during a fire. The properties of halons allow for its use in most situations and thus most of its applications are linked to particular characteristics. These principal applications include: Clean fire fighting agent: Halons leave no residue after use. This eliminates secondary damages and keeping loss caused by the fire to a minimum [12]. Electrically non-conductive: This property makes it suitable for safe application on fires involving electrical equipment. It will prevent exposure of fire fighters to electric shock. Low toxicity: This property makes halons acceptable and in most cases halon flooding systems are set in automatic mode by default. They can also be used to extinguish fires while people are present in the protected room. Halon flooding systems do not displace so much oxygen which can lead to suffocation[12] Rapid response: Halons are effective for rapid knockdown of flames. This property is mostly essential for class B fires involving liquid and liquefiable solids. Low concentration requirement: This means low quantity or amount of halons are required for extinguishment. It minimizes weight and space allowance [12]. Gaseous state: This allows for good penetration and effective extinguishment in confined spaces. Boiling point: The boiling point of about -4 allows it to be discharged (in the case of hand-held extinguishers) as a liquid for a while before it vaporises. This is a key requirement in some manual fire fighting applications.[12] Low heat of vaporisation: Halons will not condense to form water or ice in halon flooding systems. The most important advantage of halons is in its cost effectiveness. Halon fixed systems are the most cost effective of all extinguishing systems. 3.2: Extinguishing Mechanisms of Halons Halons extinguish fires both chemically and physically. Chemically they interfere with the chemical reactions that take place during the fire. This characterises halons as inhibitors. Radicals released during combustion to keep the fire burning are suppressed chemically by halons. This reaction is anti-catalytic. When halons are heated during combustion, they produce free radicals which compete with those produced by the original combustion process [2]. Halon 1301 produces bromine radicals which react with hydrogen free radicals to produce hydrogen bromide. The hydrogen bromide then reacts with hydroxyl radical to form water and bromide. The bromide released reacts with the combustion fire again and the whole cycle is repeated. The hydrogen and hydroxyl free radicals produced by combustion are greatly reduced in concentration by combining with the halogen free radicals produced by halons [3]. Where RH is the combustible fuel, XBr is a halon agent RH + O2 ENERGY OH + R †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.eqn3.1 XBr ENERGY Br + X†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦eqn3.2 RH + Br HBr + R†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦eqn3.3 HBr + OH H2O + Br†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦eqn3.4 RH ENERGY R + H†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦eqn3.5 H + Br HBr†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦eqn3.6 The combination of bromine and hydroxyl radical is also an ozone destructive reaction: HOBr UV Br + OH†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦..eqn3.7 OH + O3 HO2 + O2..eqn3.8 Br + O3 BrO + O2†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦eqn3.9 BrO + HO2 HOBr + O2 †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦..eqn3.10 3.3: HALONS AND THE OZONE 3.3.1: The ozone layer The earth is enclosed by the atmosphere. This atmosphere is made up of a mixture of numerous gases in varying proportions. The atmosphere is further subdivided into three regions depending on temperature. These regions are: Mesosphere, Stratosphere and Troposphere. The word ozone is from a Greek word, ozein, for to smell. It is an allotropic form of oxygen having three atoms in each molecule. It is a pale blue, highly poisonous gas with a strong odour. [10] In its thickest part in the stratosphere, it is only a trace gas.. Ozone is highest in concentration, about 97%, in the stratosphere (15-60 kilometers above the Earths surface) where it absorbs the ultraviolet radiation from the sun. Ozone is also highly concentrated at the Earths surface in and around cities. The buildup of ozone on the earths surface in and around cities is a result of industrial activities and is toxic to organisms living at the Earths surface. Table 3.1 shows the percentage volume composition of the constituents of atmospheric air *variable gases http://www.physicalgeography.net/fundamentals/7a.html Ozone is very reactive and a stronger oxidising agent than oxygen. It is used in purifying water, sterilising air, and bleaching certain foods. Ozone is formed when an electric spark is passed through oxygen. Ozone is prepared commercially by passing cold, dry oxygen through a silent electrical discharge [7]. Ozone formed in the atmosphere is from nitrogen oxides and organic gases emitted by automobiles and industrial sources [7]. This is achieved by short wavelength ultraviolet. This is actually a health hazard, and it may cause crop damage in some regions. Ultraviolet wavelengths less than 200 nanometer reacts with oxygen molecules to make ozone. O2 UV O + O†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦eqn3.11 O + O2 O3 + Heat†¦Ã¢â‚¬ ¦.eqn3.12 The heat released here is absorbed by the atmosphere and results in a rise in temperature of the atmosphere. The structure of ozone has 3 oxygen atoms, but steric hindrance prevents it from forming a triangular structure, with each O atom forming the expected 2 bonds. Instead each atom of oxygen forms only 1 bond, with the remaining negative charge being spread throughout the molecule.[7] Ozone is very unstable. It is decomposed either by collision with monoatomic oxygen or by ultraviolet radiation on it. The decomposition causes ozone to form oxygen molecules. Heat is also released to the atmosphere by this reaction O + O3 O2 + O2†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.eqn3.13 O3 UV O2 + O + Heat†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.eqn3.14 Ozone is decomposed in the stratosphere to prevent highly energetic ultraviolet radiation from reaching the surface of the earth. 3.3.2: Halons and ozone depletion The ozone layer is mainly depleted by compounds containing chlorine and bromine. Halogens are a chemical family containing fluorine, chlorine, bromine and iodine; any carbon compound containing them is known as a halocarbon. While all halogens have the ability to catalyze ozone breakdown, they have an unequal impact on the ozone layer. The quantity of halons released into the atmosphere is small relative to the number of gases present in the atmosphere. Yet they are more active in destroying the ozone or disrupting the ozone balance for two reasons: Ozone is in a constant state of imbalance, as it is destroyed and produced by natural processes. This process is controlled by solar input that does not undergo significant fluctuations. The stability of halons makes it transportable from the troposphere to the stratosphere where halogens are made active and broken down very fast, destroying ozone in the stratosphere. . The impact is described as depletion potential of the halocarbon. The OZONE DEPLETING POTENTIAL (ODP) is a simple measure of its ability to destroy stratospheric ozone. The ODP of compounds are calculated with reference to the ODP of CFC-11, which is defined to be 1. Thus ODP is a relative measure. A compound withan ODP of 0.2 is, roughly speaking, one-fifth as bad as CFC-11. The ODP of a compound x is expressed mathematically as the ratio of the total amount of ozone destroyed by a fixed amount of compound x to the amount of ozone destroyed by the same mass of CFC-11[8]: Global loss of Ozone due to x ODP(x) == †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦..eqn3.15[8] Global loss of ozone due to CFC-11. The above expression depicts that the ODP of CFC-11 is 1.0 by definition. The uncertainties experienced in evaluating the global loss of ozone due to a compound are eliminated here since the mathematical expression is a ratio. Evaluating the ODP of a compound is affected by the following: The quantity of chlorine or bromine atoms in a molecule. The nature of the halogen, as bromine is a more ozone- destructive catalyst than chlorine. Atmospheric lifetime of the substance: The atmospheric lifetime of the halon is the time it takes for the global amount of the gas to decay to 36.8% of its original concentration after initial emission. Compounds with low atmospheric lifetimes have lower ODP because it is destroyed in the troposphere. Molecular mass of the substance: This is because ODP is evaluated by comparing equal masses and not number of moles. Table3.2 gives time-dependent and steady-state ODPs for some halocarbon in wide use. Compound Formula Ozone Depletion Potential 10yr 30yr 100yr Steady State CFC-113 CF2ClFCl2 0.56 0.62 0.78 1.10 Carbon tetrachloride CCl4 1.25 1.22 1.14 1.08 Methyl Chloroform CH3CCl3 0.75 0.32 0.15 0.12 HCFC-22 CHF2Cl 0.17 0.12 0.07 0.05 Halon-1301 CF3Br 10.4