Characteristics of Good Test Questions Essay

Here is the list of characteristics that you should follow when either writing or selecting interpretive exercise questions for use in Stage 2 of any curriculum planning. Examples of these characteristics and why they are important will be discussed in class. Interpretive exercise questions consist of a series of selective response items based on a common set of introductory material. The introductory material may be in the form of written materials, tables, charts, graphs, maps or pictures. These questions are the hardest to write, because you have to find novel introductory material related to your unit of instruction that works and is important. The reason for including this type of question in a unit test is that it gives students practice answering this type of question which is often used on standardized tests in science. Advantages: 1. Measure the ability to interpret the introductory material encountered in everyday situations. 2. Measure more complex learning outcomes than is possible with other forms of selected response items. 3. Minimizes the influence of a students’ lack of needed factual information on measurement of complex learning outcomes. 4. Greater structure than essay test. 5. A question type used in standardized tests. Students need to be familiar with this question type. Limitations: 1. Hard to construct: find materials that are new (novel) but relevant. Usually needs some editing. 2. Heavier demand on students’ reading skill. Keep reading level low, passage brief. In primary grades use more pictorial materials. 3. Cannot measure students’ overall approach to problem solving (doesn’t show work steps). 4. Only test problem-solving ability at the recognition level. Interpretive Exercise Guidelines: 1. Select introductory material that is in harmony with course outcomes. 2. Select introductory material that is appropriate to the curricular experience and reading level of the student. 3. Select introductory material that is new (novel) to the student. 4. Use introductory material that is brief, but meaningful. 5. Revise introductory material for clarity and conciseness for greater value. 6. Construct test items that require analysis and interpretation of the introductory material. 7. Make the number of test items roughly proportional to the length of the introductory material. 8. When constructing the test items use the guidelines given in the writing of selective response items.

DNA Extraction Essay

Much can be learned from studying an organisms DNA. The first step to doing this is extracting DNA from cells. In this experiment, you will isolate DNA from the cells of fruit. Materials (1) 10 mL Graduated Cylinder(2) 100 mL Beakers15 cm Cheesecloth1 Resealable Bag1 Rubber Band (Large. Contains latex pleasewear gloves when handling if you have a latex allergy).Standing Test TubeWooden Stir StickFresh, Soft Fruit (e.g., Grapes, Strawberries, Banana, etc.) ScissorsDNA Extraction SolutionIce Cold EthanolYou Must ProvideContains sodium chloride, detergent and waterFor ice cold ethanol, store in the freezer 60 minutes before use. Procedure If you have not done so, prepare the ethanol by placing it in a freezer for approximately 60 minutes. Put pieces of a soft fruit into a plastic zipper bag and mash with your fist. The amount of food should be equal to the size of approximately five grapes. Use the 10 mL graduated cylinder to measure 10 mL of the DNA Extraction Solution. Transfer the solution from the cylinder to the bag with the fruit it in. Seal the bag completely. Mix well by kneading the bag for two minutes. Create a filter by placing the center of the cheesecloth over the mouth of the standing test tube, pushing it into the tube about two inches, and securing the cheesecloth with a rubber band around the top of the test tube. Cut a hole in the corner of the bag and filter your extraction by pouring it into the cheesecloth. You will need to keep the filtered solution which passes through the cheese cloth into the standing test tube. Rinse the 10 mL graduated cylinder, and measure five mL of ice-cold ethanol. Then, while holding the standing test tube at a 45 angle, slowly transfer the ethanol into the standing test tube with the filtered solution. The color has been enhanced by dying the fruit with a substance that glows under black light.DNA will precipitate (come out of solution) after the ethanol has been added to the solution. Let the test tube sit undisturbed for 2 – 5 minutes. You should begin to see air bubbles form at the boundary line between the ethanol and the filtered fruit solution. Bubbles will form near the top, and you will eventually see the DNA float to the top of the ethanol. Gently insert the stir stick into the test tube. Slowly raise and lower the tip several times to spool and collect the DNA. If there is an insufficient  amount of DNA available, it may not float to the top of the solution in a form that can be easily spooled or removed from the tube. However, the DNA will still be visible as white/clear clusters by gently stirring the solution and pushing the clusters around the top. Post-Lab Questions What is the texture and consistency of the DNA DNA is viscous and greasy. Why did we use a sa lt in the extraction solution High salt makes DNA less soluble in water. In order to dissolve, the water needs to interact with the DNA. Since DNA is quite large, it needs to interact with lots of water for this purpose. When you add salt, the water preferentially interacts with the salt (its small, and can move around in solution easier than the DNA can). This makes it so there is less water available to interact with the DNA and it becomes less soluble. Is the DNA soluble in the aqueous solution or alcohol DNA is less soluble in an alcohol such as isopropanol than it is in water. This is because alcohols are non-polar, whereas water is polar. The polar water molecule is much better at distributing the negative charge on DNA, causing it to remain in solution. However, since alcohol is non-polar, the negatively charged molecules of DNA tend to group together, forming clumps, which precipitate out of the alcohol solution. What else might be in the ethanol/aqueous interface How could you eliminate this When you precipitate the solution with cold ethanol 70 you would have a mix of DNA, RNA and some soluble salts. You should be able to centrifuge again so the DNA/RNA forms a pellet and drain the liquid out. Which DNA bases pair with each other How many hydrogen bonds are shared by each pair How is information to make proteins passed on through generations Watch the following Virtual Lab demonstrating DNA Extraction. In this experiment, how do the Lysis Solution and the Salt Solution vary by function Identify one step which was included in the Virtual Lab which was not required in the hands-on experiment. Then, identify one step which was included in the hands-on experiment, but not the virtual lab.

Critically analyze laws of comparative advantage Essay

Critically analyze laws of comparative advantage - Essay Example The theory of comparative advantage formulated by English economist David Ricardo in the early nineteenth century1. Ricardo encouraged each country to specialize in producing commodities for which it is best suited and then trade with other countries to obtain a wide variety of goods. The increased efficiency of production within each country makes greater worldwide consumption possible. This theory suggests that all nations have an interest in opposing restraints on trade. If less developed countries (LDCs) remain isolated and closed to foreign trade and investment, they lose opportunities to benefit from the technology, capital, and consumer goods offered by industrialized nations (Barry Clark, 1998). The theory of comparative advantage, of course, argues that unrestricted exchange between countries will increase the total amount of world output if each country tends to specialize in those goods that it can produce at a relatively lower cost compared to potential trading partners. Each country then will trade some of those lower-cost goods with other nations for goods that can be produced elsewhere more cheaply than at home. At the end of the day, with free trade among nations, all countries will find that their consumption possibilities lie outside their domestic production possibilities. The basic theory assumes that all the factors of production are... Further, it is assumed that perfect competition, and not monopoly production prevails and that all resources in each country are fully employed. The last is an especially important assumption, particularly for less-developed nations, since with less-than-fully employed resources, tariffs or other forms of protection (including subsidies) to block imports and to increase domestic employment could well be the preferred policy. With less-than-fully employed resources, the key allocative issue becomes an internal mobilization of domestic resources to their full use, rather than a reallocation among alternative uses. To be reasonably confident in applying the basic Ricardian analysis and its conclusions to any country or situation, it seems sensible, in practice, to inquire to what degree the assumptions of the theory conform to the reality of the economy under investigation. (James M. Cypher, James L. Dietz, 1998) While these are important considerations having to do with the validity of assumptions in practice, there are other concerns about a blanket endorsement of the comparative advantage argument and free trade recommendations for less-developed nations. Joan Robinson's comment on the real-time effect of following free trade and specialization, at least as far as Portugal was concerned in Ricardo's original example, remains provocative and presages our reformulation. (James M. Cypher, James L. Dietz, 1998) . . The imposition of free trade on Portugal killed off a promising textile industry and left her with a slow-growing export market for wine, while for England, exports of cotton cloth led to accumulation, mechanization and the whole

Web Blog - Essay Example | Topics and Well Written Essays - 250 words

Web Blog - - Essay Example We must also consider that there is a legislation which does not allow abortion in advanced stages of pregnancy. So we can start an endless debate on when is the fetus considered as a living being, or support a law that is made to protect whether women and babies (it is advisable to abort under 21 weeks, but it is protected by the law until week 24). We must also consider the fact that, having an abortion is an operation and, by no means, women are making this decision lightly. Maybe, if talking clearly to teenagers about sex and methods of contraception was not such a big taboo, they will have enough information to make a better decision. If they are concerned about the importance of prevention and taking care of their health, they will be able to avoid unwanted pregnancies and will be much more responsible persons. But in the case they got pregnant, it is always better to have the opportunity and the adequate means to decide if they want to terminate their pregnancy or not. Sexual education is extremely important, as it is the best way to avoid abortion and to bring up responsible and careful persons. It is simply just not logical to get stuck into a position which gives priority to the fetus and not to the women’s life, and which does not allow women to decide by their selves if they want or not to have a

Networking and data security Assignment Example | Topics and Well Written Essays - 1000 words

Networking and data security - Assignment Example More often than not this kind of network of personal area network could also be interconnected lacking wires to the Internet or other even networks. To a larger extent this is true. Unlike other types of networks that are specifically fixed to an office location network wise, metropolitan area network span to the furthest boundary of a city. A metropolitan area network (MAN) can be referred to as a network that interconnects users in a geographic area or region larger than a large local area network (LAN) can cover but at the same time smaller than wide area network (WAN can cover. The statement is further true as the term MAN` is applied to the networks interconnection in a city into a single larger network. A database user, also referred to as a traditional user is individuals who are associated with passwords and schemas. For instance, an application or a person that logs onto the database, they use a database user (schema) as well as password. Database users are, therefore, able to create heavyweight sessions to the schemas that they are associated. An application user, on the other hand, can be an autonomous application process or a person that accesses information or data in the database. Unlike database users, application users do not own database schemas. However, they are able to create application sessions to databases via the middle tier. They are also able to create heavyweight database sessions via direct connection to the database. A database role is traditionally imagined to be a set of database privileges that applications, database users, or other database roles are granted. Database roles serve as intermediaries that map database privileges to database applications and users. On the other hand, an application user is often regarded as a set of application-define privileges associated with it and it is only granted to application users or to other application roles. An application role

Teeens in concentration camps Research Paper Example | Topics and Well Written Essays - 1250 words

Teeens in concentration camps - Research Paper Example Cynthia Ozicks "The Shawl portrays the cruelties of Nazi concentration camp. Stories and narratives about the concentration camps demonstrate the unending brutality and wretchedness that the Jewish young children and teenagers faced during the reign of Hitler. In the concentration camps teenagers were recruited for the Nazis and forced to undergo heavy military practices. These teen soldiers had been educated for struggle, and most of the soldiers had hardly even heard of these concentration camps. In Nazi concentration camps the teen soldiers have met thousands of hungry and struggling populace including young children who had witnessed and observed assassinations, persecution, hunger and ravage they also had been dehumanized. Eleanor H. Ayer supports â€Å"They were murdered because they had Jewish blood, and nothing they could do could change that.† (Ayer 7-8). Teens who have been recruited in to the Nazi force also suffered from severe training programs and strict disciplinary activities. Many of them have escaped from these concentration camps because of dehumanization and other conditions which were beyond their power of endurance. During the time of Nazi movement in Germany, lots of the teens became rescuers when their parents choose to conceal Jews. The teenagers survived in the ghettos of Lodz and they also lived in Warsaw. In all there places they have had to sustain physical scarcity, mistreatment, and transportation to the death camp. The Jews who lived in these concentration camps were subjected to severe physical torturing and often killed. On the other hand, for nearly all prisoners, actual celebration was not possible. The book Liberation: Teens in the Concentration Camps and the Teen Soldiers Who by Tina Tito points out that â€Å"They built death camps occupied with the most sophisticated technology available in order to kill the Jews. With the assistance of collaborators (non-Germans who

History HW Essay Example | Topics and Well Written Essays - 5750 words

History HW - Essay Example Republicans maintained that the leaders must be kept out of their political power after the war. The northerners maintained that the southern states were not to be allowed in the congress until after they had totally removed slavery out of their states. Seeing this Lincoln offered amnesty to all the whites in the south apart from those high rank officials who had stimulated the war. He also came up with a reconstruction plan to entice the southerners from their rebellion. Southern leaders, who had not been given amnesty, rejected the reconstruction laws and replaced it with another bill. This bill was known as the Wade-Davis bill and it was passed in the house after voting it in. however Lincoln refused to sign the bill after it had been passed and this made the two senators mad and prompted them to stop the reconstruction laws. Soon after, Lincoln was assassinated and this led to the rebellion from the south over his death. His successor Johnson passed three important amendments; these included the 13th amendments that abolished slavery, the 14th amendments which allowed every person born and raised in the US to be a US citizen. The 1th amendment allowed every citizen to vote. The other reconstruction that was done is the military reconstruction. In this reconstruction, the southern army was reconstructed and new leaders appointed to serve as army leaders. This was done to remove the old army leaders who had brought the fighting. Taxing reconstruction was also a major change in the reconstruction. In the past property was given value by their owners and they took the taxes themselves to the authorities, however this changed after the reconstruction of the new taxing laws. Most of the southerners were against the reconstruction laws because they felt that these laws were meant to punish them due to their resistance. This made them to oppose the laws and in turn refuse to follow the orders. The upper south soon agreed to end the opposition to the

Adenauers Foreign Policy Essay Example | Topics and Well Written Essays - 2000 words

Adenauers Foreign Policy - Essay Example n, anticommunist foreign policy for which Davison & Speier (1957) has expressed their opinion in the following words: "To a generation living with the memories of World War II, into which another German chancellor had plunged the world less than twenty years earlier, Adenauer has been the symbol of sobriety and moderation. His firm adherence to the principles underlying Western civilisation is beyond doubt, and his policies bear no trace of Hitler's nihilism and hybrid". (Davison & Speier, 1957, p. 2) And obviously both Adenauer and Brandt acquire this political characteristic that despite being chancellors of their eras, they only concern about ways to unite the broken Germany, not by aggression but by political diplomacy.Adenauer performed a historic role for confronting various challenging issues just after the Second World War. All his foreign policies lead him towards a single solution i.e., a united Europe and that is what he dreamt about throughout his life. Not only dreamt bu t also implemented his visions in the form of practical solution by developing certain policies, that remained successful in uniting both the East and West of the Germany. The best thing about Adenauer's regime was he did not receive resistance from a large communist minority. However, he received several obstructions on the basis of the opposition he received from the German Social Democratic party. Adenauer's Foreign Policy - German Sovereignty Adenauer felt the need to develop his own foreign policy in the late 1940s when he saw the German policies been threatened by France. At this stage he felt a real need to devise a new set of foreign policies but due to the restriction imposed upon him he was unable to do so. The only option he found open was to secure German sovereignty, and this could only be achieved by integrating FRG (Federal Republic of Germany) to Western Europe. Adenauer recovered Germany by effective foreign and domestic policy thereby standardising the German currency rate in 1948. It was in 1950s when Adenauer succeeded in recognising his new state's entry into Western institutions. In this context the first move he made was the acceptance of the partnership of those nations who at times were Germany's greatest opponents. France was at the top of the list. This was the first step towards establishment of a secure foreign policy that defended German sovereignty. Dissolving the Ruhr Authority Adenauer contributed towards gaining rights of the Ruhr's authority and was able to acquire freedom to the FRG thereby alleviating all provisions and statutes against European Coal and Steel Community (ECSC). According to Schwarz (1995) "The economy of Western Europe had to be regarded as an interdependent system and could not prosper without the Ruhr. In his view it followed from this that a forced suppression of the German economy was in no-one's interests. Drawing on his experiences stretching back over almost three decades, he maintained that the establishment of a bloc-free Germany would be unwise, too. He pleaded for a reconstruction of the German economy; this meant that the Ruhr should be internationalised and linked closely with the Western European economic system". (Schwarz, 1995, p. 40) So, the foremost achievement of Adenauer was the independence of Ruhr authority, which without him

Forensic Botany Essay Example | Topics and Well Written Essays - 1500 words

Forensic Botany - Essay Example There are issues of specificity, profile complexity, and reproducibility that lead to the rejection of botanical evidence in courts. Moreover, a higher number of samples, translating to the urgency for analysis to yield quality and quantity have often yielded poor DNA making analysis less effective (Hall, Byrd, & Wiley InterScience, 2012). These factors usually introduce new challenges in the identification of evidence in forensic botany. Scientists have identified the fact that most of the evidence comes in mixed proportions, complicating the analysis process. Therefore, this heightens the need to develop techniques that have the potential of sorting out the mixed samples to present specific evidence. Such effective methods will help investigators rely on botanical evidence that is subject to being discarded in the current days. The development of numerous techniques used in DNA profiling has served to lay a hope for the possibility of better approaches of identification that yield evidence that is dependable in courts. Apparently, an effective DNA analysis technique for use in forensic botany must meet certain requirements. The approach must have the potential of establishing distinct differences between individual species irrespective of a high correlation. Moreover, it should have the capacity to handle robust amounts of samples (Bock, & Norris, 2008). An additional requirement of immense criticality is the fact that the technique must exhibit the potential of positively analyzing degraded plant materials. Although scientists have made progress in developing tools with the capacity to satisfy the above described requirements, only a few of the developed techniques have the potential of meeting all the... The development of numerous techniques used in DNA profiling has served to lay a hope for the possibility of better approaches to identification that yield evidence that is dependable in courts. Apparently, an effective DNA analysis technique for use in forensic botany must meet certain requirements. The approach must have the potential of establishing distinct differences between individual species irrespective of a high correlation. Moreover, it should have the capacity to handle robust amounts of samples. An additional requirement of immense criticality is the fact that the technique must exhibit the potential of positively analyzing degraded plant materials. Although scientists have made progress in developing tools with the capacity to satisfy the above-described requirements, only a few of the developed techniques have the potential of meeting all the requirements. However, the short tandem repeats (STRs) and single nucleotide polymorphisms (SNPs). Moreover, bar coding has emer ged for better analysis in the future.Specialists are usually very keen in making sure that collection of samples follows a standard procedure. The collection is a critical step because the seizure of the samples of interest occurs at this point. Prior to the collection of the intended samples, there is a need for a specialist to embark on an effective recognition procedure, before collection of the sample accurate recognition serves as the initial step in the dependence of forensic botany in identifying any sort of crime.

Special Educational Needs Essay Example for Free

Special Educational Needs Essay This is a transition time for Special Educational Needs and Disabilities – new legislation in the form of a green paper â€Å"Support and Aspiration† is advancing through the necessary stages and considerable changes are promised to be implemented by 2014. An understanding of the historical perspective and the future proposals contained in â€Å"Support and Aspiration† will therefore be helpful. Definitions: (From the current SEN Code of practice 2001) The Educational Act 1981 laid down a legal definition of Special Educational Needs in schools. That definition was repeated in the Educational Act 1993 and in the consolidation Education Act 1996. According to law: 1. A child has special educational needs if he or she has a learning difficulty which calls for special educational provision to be made for him or her. 2. A child has a learning difficulty if he or she: a) has a significantly greater difficulty in learning than the majority of children of the same age b) has a disability which either prevents or hinders the child from making use of educational facilities of a kind provided for children of the same age in schools within the area of the local education authority c) is under five and falls within the definition at (a) or (b) above. The following children fall outside the legal definition of Special Educational Needs a) Those whose language at home is different from the language in which they are taught at school b) gifted children Anticipated changes Summarized from https://www.education.gov.uk/publications/eOrderingDownload/Green-Paper-SEN.pdf The Green Paper, Support and Aspiration: A new approach to special educational needs and disability, sets out the government’s intention to radically reform the current system for identifying, assessing and supporting children and young people who are disabled or have SEN, and their families. The Green Paper proposals and the Government’s wider reforms in education and health will make the best use of limited resources through better planning, streamlining assessment processes, making the system less adversarial and focusing on achieving better outcomes. Reforms are already being tested through local pathfinders, developing the knowledge and skills that will be needed for their successful implementation, and making sure that the right measures are in place to hold services to account. The lessons learnt from the pathfinders will help shape the changes. In the Green Paper the government pledges by 2014 to introduce: †¢ A single assessment process which is more streamlined, better involves children, young people and families and is completed quickly; †¢ An Education, Health and Care Plan which brings services together and is focused on improving outcomes; and †¢ An offer of a personal budget for families with an Education, Health and Care Plan. The government intends to introduce legislation through a Children and Families Bill to implement the changes to the law required for the Green Paper reforms. A draft bill will be published in summer 2012 for consultation and pre-legislative scrutiny. Application It is not yet clear how the changes will impact schools or what adjustments will be required in administration and â€Å"grass-roots† provision. Tutors will inform students of changes as they emerge.

Ebay Culture Essay Example for Free

Ebay Culture Essay What is organizational culture? This indefinable combination of values, beliefs, and practice that a corporation posses, which makes the difference between surviving and thriving, succeeding and failing. Most large corporations typically have a strong culture with values and norms appropriate to the organizational purpose. In a big organization, sub-cultures also exist, division to division, office to office. In this part of this group assignment I will describe the organizational culture of one of the most famous internet companies in the world, which is also the largest marketplace in the internet – EBay. Many articles and books have been written in recent years about culture in organizations, usually referred to as Corporate Culture. The dictionary defines culture as the act of developing intellectual and moral faculties, especially through education. This paper will use a slightly different definition of culture: the moral, social, and behavioral norms of an organization based on the beliefs, attitudes, and priorities of its internal community. Every organization has its own unique culture or value set. The culture of the organization is typically created unconsciously, based on the values of the top management or the founders of an organization. Organizational culture has been defined as â€Å"a pattern of basic assumptions, values, or beliefs and norms of behavior. According to O’Reilly, organizational culture defined as the values shared by members of an organization. These basic values may be thought of as internalized normative beliefs that can guide behavior inside an organization. If organizational culture is developed as an organization learns to deal with the dual problems of both external adaptation and internal integration, then values that enhance the organization’s capability in these two functions should be useful for it. To the extent that members of an organization share the same sets of values, thought processes, and languages, they will have similar mind-sets and behaviors as they integrate their efforts inside the organization and adapt to environmental changes. Research has documented a variety of outcomes that are related to organizational culture. For example, organizational culture has been found to relate to organization growth and organization performance. Other studies have shown that its effect can be observed directly at the individual level, in outcomes such as commitment, resource allocation decisions, retention, and perceived attractiveness of an organization. Given the dramatic changes in both the external environment and the internal structure of worldwide organizations, organizations that emphasize cultural values that relate to external adaptation and internal integration should be more effective than those that do not. The character of any corporation or an organization characterized by set of values and principles by which the founders and the upper management run the company from its creation when it’s really begin to become part of the DNA of the company. I believe that companies form culture very early on and they get imprinted very early on with a sense of right and wrong. And it starts from the top. It started with the CFO, the President, and CEO. According to Whitman, sis he had innate sense that they needed at EBay to establish very early on what the code of behavior was going to be, what the code of ethics would be. EBay’s internal company culture was very dominant and strong. Even though its culture had great influence of its member’s behavior, the culture encourages its members to feel more commitment. Employees were expected to be open and honest, to treat one another with respect, and to speak up if they believed they were not being treated in this manner. EBay functioned as being a nonhierarchical, democratic organization that encouraged ideas and feedback from all employees. The culture at eBay characterized as being open and low risk, where employees were encouraged to express their opinions despite their different points of view. Mistakes were acceptable, but employees were encouraged to truly learn from them. According to Whitman, unlike other companies where different views and opinions from the senior management were barely heard , at EBay they do not have â€Å"punishes† attitude, meaning that there is no penalty for being on the wrong side of an issue or changing your mind in the face of better information. If an employee`s point of view contradict with his/her colleague when you end up convinced to be wrong, the culture is to appreciate your opinion and at the same time to come with the approach of: â€Å"ok? hat’s smart. You’re right. Let’s move on. † In addition, As role models, senior managers had to act with a high degree of professionalism and respect. EBay does not encourage people who scream loud or pound the tables. At EBay, it’s pretty even-keeled culture. Sustaining its culture provide a better understanding of the strength of the culture. As EBay grew , in order to conserve the unique internal culture of the organization, EBay made sure it hires only individuals who fit with the culture of the organization. In order to emphasize the importance of its culture, EBay`s CEO Meg Whitman, met with new candidates and describe eBay’s values and to set expectations for how each employee would support and contribute to the company’s culture. According to EBay founder Pierre Omidyar, experience was not the only quality they were looking in potential applicants, but for someone who really understands the significance of its both internal and external communities and that person should express its most respect to these communities. Moreover, measuring the community and organization very often represents a major challenge in terms of being sure the values and culture of EBay are being communicated correctly. Therefore, on the organizational side, they had to be sure they were hiring quality employees who fit with the culture; they could not afford to let that slip. Even though most well establish cultures resist changes, EBay was able to accept changes within its upper management and the way it works. For example, when Whitman arrived EBay she tried to make some changes because she felt they were needed the way the company goes and in order to adapt to these new changes. An example would be her trying to set up these meetings, but no one had a calendar. According to Whitman, at EBay this was a culture where appointments were not needed because of its small size there were only 35 people at the company. So she laid out a calendar and asked people to sign up for appointments. She did not appreciate the feedback; the employees did not like the changes. What ended up happening was that the employees who had previously worked in big companies signed up for multiple meetings, and the people who had worked primarily in start-ups didn’t sign up at all. Furthermore, EBay`s culture was designed to mirror its external community culture. Very important element of EBay`s culture is a respect for its community. It goes far beyond â€Å"the customer is always right† because eBay wouldn’t exist if it weren’t for its community The meetings helped Whitman realize just how special the chemistry was between eBay’s internal and external communities. EBay’s internal culture mirrored many of the characteristics of its external community culture in tangible ways: they were empowered to develop recommendations, and the company employed a nonhierarchical, team-based approach to problem solving. According to Omidyar this configuration was so important: Internally, EBay had to share the same values as their community because they indirectly influence the community in everything they do. Everything EBay put on the Web site, every press release, every utterance to the press, every corporate action, every deal, every partnership that happens in any part of the organization eventually trickles down to the community. EBay rely on all of its executives and then their managers to continue to communicate the culture. The message should trickle down to the very last employee, so that everyone really understands what we’re about and what our values are. EBay also encourage its employees to call the upper management if we’re doing something that is not quite right. EBay empowered everyone to be a guardian of the culture everyone.

Development of Sustainable LED Lighting for Offices

Development of Sustainable LED Lighting for Offices CHAPTER 1 INTRODUCTION 1.1: Study Background Climate change is rapidly increasing in our environment due to an increase in gases such as carbon dioxide and methane produced by humans and animals in the Earths atmosphere. As humans we have a moral responsibility to control and save the environment. The built environment is one of the major impacts towards greenhouse gas emissions. Designers are now pressured to design sustainable buildings that have less impact on emissions that damage the environment. The term sustainability means to save natural resources for future generations. Many buildings indirectly use resources such as fossil fuels which are converted into energy. Lighting systems in buildings consume some of this energy. Lighting accounts for around 15% of the energy bill in most homes, and around 25% in commercial buildings. It is supplied by electrical power plants using fossil fuels, and is responsible for a significant percentage of carbon dioxide emissions (Marshall 2009) To help combat how we as consumers use electric lighting an alternative can be achieved via sustainable lighting. Sustainable lighting can be defined as, Lighting that meets the qualitative needs of the visual environment with the least impact on the physical environment. (Service Lamp Corp. 2001) Light is an electromagnetic radiation, which means it is partially electric, magnetic and radiates.   Light starts off from atoms (electrons that orbit the nucleus). When energy is absorbed by an atom the electrons shift up to a bigger orbit. When the atom loses the energy the electrons shift back down to the original orbit, while the electrons shift back down they emit light in the form of electromagnetic radiation. (Sarlina 2009) This document will review material on lighting systems in the office environment. The document will start with a brief history of the light bulb and then go on to how humans interpret light. The document will discuss how LED technology would be utilised more in offices and discuss the importance of migrating to LED lighting systems in offices for a more sustainable environment. The thesis will include three known case studies on LED lighting installed in offices to gather and compare data in order to evaluate how LED lighting would suffice in real life environments. 1.2: Brief History The history of modern lighting starts off with the invention of the arc light in 1810 by Humphrey Davy. This worked by connecting a battery to a strip of charcoal using two wires. The strip of charcoal was charge with electricity and glowed. (Jacks 2003) In 1820 Warren De La Rue used a piece of platinum placed inside a tube.   A current was passed through the tube and the platinum lit well but the bulb did not go into production because platinum was very expensive. (Jacks 2003) A chemist and physicist Joseph Wilson Swan produced a workable electric light in 1860 which he patented as an incandescent light bulb with a filament made from carbonised paper within a partial vacuum. J. W. Swan improved on the invention in 1875 he changed the filament to a compressed and carbonised fibrous cotton thread filament. (Jacks 2003) An inventor called Thomas Alva Edison bought Josephs Swans patent from a company who owned the patent.   Thomas Edison worked on the light bulb to increase the life span. In 1880 Thomas Edison invented his Bamboo fibre filament lamp which lasted for 1200-1500 hours. (Jacks 2003) In 1903 Willis Whitnew invented the tungsten filament lamp (commonly used today). The tungsten lamp had a carbon filament with a metal-coating. This stopped the problem with the bulb turning dark as Thomas Edisons bulb did. (Jacks 2003) Technology today has advanced to new methods of lighting. Light emitting diode (LED) technology is now at the centre point of attention as LED lighting has many advantages with being very energy efficient, long lasting and produces less heat compared to standard incandescent or halogen bulbs. 1.3: Dissertation Structure The dissertation is divided into a sequel of five chapters. The first chapter focuses on climate change and the need to for a more sustainable built environment, a brief history into the light bulb, aims and objectives of this dissertation and the logic behind the dissertation. Chapter two is a detailed literature review which focuses on the effects of lighting on building occupants followed by government legislation, then comparing different types of lighting and leading onto research on LED technology. The information gathered is sourced from websites, government documents, books and scientific journals. Chapter three follows on from the literature review. This chapter focuses on the structure for the dissertation; firstly explaining the reason for using a literature review and then drawing on three major case studies have been chosen and all cases deal with LED lighting systems within office spaces. From the case studies the author has analysed and interpreted information.   The primary data gathered will be in the form of a qualitative questionnaire sent to lighting experts (via email) who have been involved with the case studies. The Answers have been analysed and compared to get a wide knowledge from accredited professional opinions. The fourth chapter researches into the three chosen case studies, all case studies are analysed and compared to give an overview of how effective having an LED lighting system is in an office environment. The fifth chapter discusses the results gathered from the findings. This would give an overview to the dissertation and show the key findings into answering the key questions. The final chapter will draw up conclusions as to the impact of LED lighting in office environments. The chapter addresses the original research question in the context of the findings and provides final conclusions on LED lighting and making use appropriate references where necessary. 1.4: Aim and Objectives The author has chosen sustainable LED lighting as the subject area in this dissertation. The question the author would like to propose will be: Why arent there enough office buildings using LED lighting systems? Also what effects do LED lighting have on users working in an office environment; would LEDs be beneficial for health and comfort on a psychological basis? To address the question the author will explore this main aim: The aim of this study is to research into the sustainability of LED lighting systems and how lighting can affect building users within an office environment. The author will aim analyse case studies on LED lighting systems in offices. What are the advantages and disadvantages? How would an LED lighting system be best suited for the office environment in terms of efficiency, comfort, reliability and short long term costs? The author will interview people from case studies drawn to gather primary qualitative information to reach a final conclusion. The actions the author will take to help answer the research question are listed below: Literature review, take into account of the building regulations, effects of artificial lighting on building occupants, types of artificial lighting and researching into books, case studies, reports, journals and websites related to LED lighting and other sustainable lighting systems. Research case studies on LED lighting systems that have been installed in offices. This would give the author an insight on how LED lighting systems have been successful in a real life environment. Interview researchers from case studies. Ask questions about how LEDs are designed to fit in a working office environment. Any issues that have occurred within the buildings. 1.5: Hypothesis In the United Kingdom there are very few offices if any that use an LED lighting systems to light up an office space. This could be due to lack of awareness, economic climate, social environment and lack of technology available to solve prob lematic conditions. 1.6: Key questions 1. How does light effect building users in terms of health? 2. How would LED lighting benefit offices and the environment? 3. Why isnt there many offices using LED lighting systems? 4. What is the current market like for LED lighting? Would there be a future for more LED lighting in offices? CHAPTER 2 LITERATURE REVIEW 2.1: Introduction This chapter researches into the effects of lighting on buildings occupants, legislation, different types of lighting and LED technology in detail. The aim for this literature review is to obtain information on how light is transcribed in the circadian system and the effects of light on human health. Legislation is a key issue for lighting. it regulate on the amount of light required for the appropriate tasks usually attained in different buildings, by learning legislation it would give the author an understanding into what requirements an office would need for good lighting. All information collated are from secondary and tertiary sources; for this literature review the information is found in books, journals, web pages, and government documents. 2.2: Effects of lighting on building occupants Lighting affects all building occupants on the way they perform tasks. There are different levels of lighting in different environment; the colour of light used in offices would tend to have a blue-white colour to promote concentration and light used in public areas would be a warmer yellow colour so building occupants would feel more relaxed in this type of environment. Too much light can cause health problems such as increased stress levels, headaches and higher blood pressure to the building occupant. (H.E.S.E, 2009) (Boyce, 2003 pp. 160) stated that Most apparently visual tasks have three components; visual, cognitive, and motor. Every task is unique in its balance between these components and hence in the effect lighting conditions have on task performance. (Boyce, 2003 pp. 160) also stated that Lighting conditions can affect task performance throught three systems, the visual system, the circadian system, and the perceptual system. the impact   of lighting conditions on the visual system and hence on visual performance is determined by the size, luminance contrast, and colour difference of the task and the amount, spectrum, distrbution of the lighting. The point that   (Boyce, 2003) makes is that light sent to the visual system affects the performance of the information relayed in the brain.   (Cuttle, 2008 pp. 5-6) stated The optical system of the human eye focuses an inverted image onto the retina, shown in Figure 1. This image is constantly changing with movements of the head and the scanning movements of the eyes. It is often said that the eye is like a camera, but the only similarity is that it forms a focused image in which, for every pixel, there is a corresponding element in the luminous environment. The distribution of luminance and colour that comprises the retinal image is modified by light losses that occur in the optical media of the eye, and these losses are not constant as they increase significantly with age. (Cuttle, 2008) Both books express points about how light is interpreted in the human brain differently but they both correlate how light can affect a building occupant. They both state how light is interpreted in the visual system. A research journal on Light Much More Than Vision written by Mark. S. Rea (Ph.D.) Discuses how lighting can affect the circadian system in building occupants. The journal questions if offices, school and homes are providing good lighting practises. The journal begins with an abstract on the impact of light on the circadian system The amount of light, its spectral composition, spatial distribution, timing and duration needed for vision is so different from that needed for circadian functioning, that generalizations about good lighting will have to be assessed by two very different sets of criteria in the future. (Mark. S. Rea, 2007) The journal continues on how light is interpreted in the human circadian system Light is presently and formally defined as optical radiation entering the eye that provides visual sensation. An international system of photometry has been developed and institutionalized to quantify, measure and communicate the properties of light as it affects the human vision. (Mark. S. Rea, 2007) This statement explains how light is communicated in human vision.   Practical sources of light allow humans to read material, move around spaces, drive cars, create social interaction between other users and allow user to do other activities. Under spatial distribution the journal states Through optical refraction by the cornea and lens in the eye and by neural-optical enhancements by in the retina, the spatial distribution of objects and textures in the environment can be processed by the visual system. Arguably accurate rendering of the spatial distribution of light in our environment by our retina is essential to our survival because   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   patterns of light and dark provide information needed by the visual system (Mark. S. Rea, 2007) The journal concludes with So, Are we providing healthy light in our offices, schools and homes? Probably the answer is No, we are not. Certainly we are not providing or specifiying the ideal lighting technologies and applications for the circadian regluation (Mark. S. Rea, 2007). This would bring on the question as to wether LED lighting would provide the answer to good lighting. LED has been evolving for years, they have been specifically modified to provide comfortable lighting levels for which a user could carry out certain visual functions. 2.3: Legislation The Kyoto agreement is a protocol made by the United Nations Framework Convention on Climate change. This main aim of the protocol is to stabilise greenhouse gas emissions. There are four greenhouse gases that the protocol focuses on (carbon dioxide, nitrous oxide, methane, sulphur hexafluoride). The United Kingdom Government is legally tied to the Kyoto agreement and has set out targets to meet emission rates. A document on The Kyoto Protocol by British-Energy states The UKs commitment under the protocol is for a reduction in greenhouse gas emissions of 12.5% from 1990 levels by 2008-2012. This implies an 8% reduction in CO2 emissions over this time period. The UK government also has an aspirational target for itself of a 20% reduction of CO2 emissions by 2010, demonstrating the importance of this issue for the current government.(British Energy, 2009) Offices contribute towards the CO2 emissions given off around the planet. A lot of the energy used in offices is mainly caused by office lighting. The new advancements in LED lighting could reduce the amount of energy used because LED lighting is the most sustainable type of artificial lighting. This could help aid the efforts of the Kyoto Protocol and help meets emission targets. Approved Documents Part L of the building regulations is split up into four documents. Part L1A and L1B focuses on conservation of fuel and power in domestic buildings, part L2A and L2B focuses on conservation of fuel and power in non domestic buildings. As of 6th April 2006 the revised Building Regulations Part L Conservation of Fuel and Power came into effect. The updated regulations would improve energy standards by 40 percent from that of the 2002 Building Regulations (ODPM, 2006). There are four approved documents published by the Office of the Deputy Prime Minister (ODPM, 2006): Approved Document L1A: Conservation of fuel and power (New dwellings) (2006 edition) Approved Document L1B: Conservation of fuel and power (Existing dwellings) (2006 edition) Approved Document L2A: Conservation of fuel and power (New buildings other than dwellings) (2006 edition) Approved Document L2B: Conservation of fuel and power (Existing buildings other than dwellings) (2006 edition) L1 Domestic buildings Conservation of fuel and power in dwellings. Limiting heat loss through fabric of dwelling from hot water pipes used for space heating. Limiting heat loss through hot water vessels and service pipes. Use control systems on space heating and hot water systems so that energy can be used efficiently. Use control systems on lighting systems so that energy can be used efficiently. L2 Buildings other than dwellings Conservation of fuel and power in non domestic buildings. Limiting heat loss through fabric of dwelling from hot water pipes used for space heating. Limiting heat loss through hot water vessels and service pipes. Use control systems on space heating and hot water systems so that energy can be used efficiently. Providing lighting systems with sufficient controls so that energy can be used efficiently. Limiting exposure to solar heat gains. Use control systems on air conditioning and mechanical ventilation systems so that energy can be used efficiently. Commissioning the building engineering services so that they make efficient use of energy and recording their performance. Approved Document L2A: Conservation of fuel and power highlights what is required for lighting efficiency in offices, industrial and storage areas in all building types. The document states For the purposes of this Approved Document, office areas include those spaces that involve predominantly desk-based tasks, including classrooms, seminar rooms and conference rooms, including those in schools. Reasonable provision would be to provide lighting with an average initial efficiency of not less than 45 luminaire-lumens/circuit-Watt as averaged over the whole area of these types of space in the building. (ODPM, 2006 pp. 19) LED lighting has the potential to excel past the average guide for initial efficiency of 45 lumens per watt. A breakthrough from the lighting company CREE states LED efficacy test results that set a new benchmark for the LED industry. Cree reported results of 131 lumens per watt white LED efficacy, confirmed by the National Institute of Standards and Technology in Gaithersburg, Maryland. Tests were performed using prototype white LEDs with Cree EZBrightâ„ ¢ LED chips. (CREE Inc, 2009) The CIBSE Lighting Guide 7: Office Lighting gives a guidance of how to layout lighting systems within an office to give the maximum efficiency of lighting and how much light is required for different types of office spaces. The guide states There are many ways to light an office space: with direct light down from above, from indirect light bounced from the ceiling, or from a combination of both. Many factors will dictate or influence the choice of which technique to use.   (Ruffles, 2005 pp. 7) There are many different building types and each office would need a lighting system that is individually specified. There are different types of lighting systems that give off different light intensities. The lighting guide states that a typical office space would need 500 lux (illuminance) for building users to take on paper-based or mixed tasks comfortably and 300 lux for any screen-based work. (Ruffles, 2005) Figure 2 shows the required amounts of light need for building user to work within different types of offices spaces, taken from the office lighting guide. The figures suggest that each typical office space would need 300 lux for screen based tasks, normal meetings and reception administrative tasks and 500 lux for more intense tasks such as paper-based, reading documents and writing. In a more deep-plan area the office space is required to have 500-750 lux throughout to perform multiple tasks comfortably. This is due to the fact that deep-plan areas are more towards the middle of office spaces or more than six meters away from windows; they would require a more constant flow of artificial light. This is where LED lighting may be at best because of the amount of electricity LED lighting systems take are very minimal and could deliver the required amount of light depending and the type of fixture. In normal deep-plan areas artificial lighting systems are on for longer periods because natural lighting coming in from windows would not penetrate throughout the office spaces. The corporation Philips suggests that a higher powered LED light would deliver up to 220 lumens. This type of LED would typically consume four watts. A typical deep-plan office space would require three high powered LED lights to deliver a comfortable amount of light for a user to perform various tasks, which would still consume less electricity compared to other office lighting systems. 2.4: Types of lighting There are many types of lamps that are currently used in different environments. These lamps include the incandescent lamp, compact fluorescent lamp, fluorescent lamp, halogen lamp, metal halide lamp and light emitting diodes. Incandescent lamps An incandescent lamp is a glass (See figure 3) bulb containing a thin filament. A current is passed through the filament, which heats up the filament until light is produced. (Philips, 2000 pp.49-50) stated The earliest filament lamps as developed by Swan in the United Kingdom and Edison in the United States had a short life of only 150 hours and a low efficiency of 2.5 lumens per watt, but they were thought of as a magic light source to replace gaslight. Filament lamps were clean, had greater flexibility, better colour and, with the development of available sources of power, better long-term economics. Now, a century later, the light bulb is still the preferred lamp for domestic use due to its cheap cost. Phillips (2000) continues to state that The life of a filament lamp depends upon its light output, with a greater output giving a shorter life. A life of 1000 hours with a light output of 12/14 lumens per watt was established as being a reasonable compromise and one which has stood the test of time. (Bean, 2007 pp. 139) explains that a compact fluorescent lamp is the introduction of smaller diameter tubes using high efficiency triphosphors bought with it the posibility of folding the tubes to produce compact single ended lamps. A 12W compact fluorescent lamp gives the same output as a 60W tungsten GLS lamp. Fluorescent Lamps (Fielder, 2005 pp. 28) states that Fluorescent lamps are built using a tubular glass envelope coated on the inside with a mix of phosphors. Inert Gas and a small amount of mercury is introduced into the tube to provide the atoms for photoluminescence. the tube is slightly pressurized, and the ends of the tube are capped with electrodes, which contain a cathode to generate and arc. Fluorescent lamps are 8 times more efficient than incandescent lamps and have a long life span, but fluorescent lamps contain mercury shown in figure 5. Mercury in lamps is harmful for the environment if not disposed of appropriately. Halogen Lamps The Interior Lighting for Designers book articulates that The tungsten-halogen   (or halogen)   lamp is an incandescent lamp with a selected gas of the halogen family sealed into it. As the lamp burns, the halogen gas combines with tungsten molecules that sputter off the filament and deposits the tungsten back on the filament   (Gordon, 2003 pp. 73). Figure 6 below shows an example of what a typical halogen lamp looks like. Metal Halide Lamps Metal halide lamps produce white light of a good colour quality and are available in many sizes, from compact lamps that can be used in track lighting and table lamps to huge lamps for lighting stadiums. Standard metal halide lamps tend to have a colour temperature of 3700 to 4100K and appear cool and slightly greenish. Their CRI is 65 to 70. Standard metal halide lamps typically are used where colour is not critical, such as sports arenas, parking lots, landscape lighting, and building floodlighting. (Benya, 2004 pp. 9-10) Light Emitting Diodes (LEDs) An LED is a semiconductor device that emits light when a voltage is surged through the semiconductor.   LED solid-state lighting is becoming more in use because of the energy saving benefits and long term costs. The main types of light bulbs used in offices are fluorescent lamps, incandescent tungsten filament (halogen lamps) and metal halide lamps. Fluorescent lamps are the main types of light sources used in offing lighting; the table states that the fluorescent tubes has a lamp efficiency of 32-86 Lm/W (Lumens per watt) this has a higher efficiency compared to incandescent tungsten filament lamp which have an efficiency of 7-14 Lm/W. Also fluorescent lamps can last more than ten times longer than incandescent tungsten filament lamps, but the tungsten filament lamps has a colour rendering index of 99 which means that the light intensity is much higher and would provide light that is closer to natural daylight compared to fluorescent lamps. Tungsten lamps are mainly used for executive offices to give an office a more professional looking environment. Metal halide lamps are used for desk lamp for more detailed important task where more light may be required for analytical reading and writing /complex drawing tasks. 2.5: LED technology LED technology is a fast growing lamp replacement solution in the lighting industry. LEDs contain semiconductors which are atoms of arsenic, phosphorus, germanium or other elements found in the periodic table. When electricity passes through the semiconductor visible light is emitted. Placing a number of LEDS side by side increases the increases the strength of the brightness. LED lights are also dimmable so the user could control the light intensity in a given area. The advantages of using LEDS are that they have a 50,000 to 100,000 hour life span, they consume very little electricity, they instantly light up, LED lights do not emit UV rays, they are durable to   vibrations they do not contain any mercury and LED emits light from any part of the light spectrum. The disadvantages of using LED lighting are that light is distributed directly instead of evenly compared to incandescent and fluorescent bulbs; it is very expensive to buy LED lights, they could cause light pollution in an environment because LEDs produce a lot of white light and LEDs are sensitive to heat. LED lighting is still currently being researched today to find out better methods to utilise the light from LEDs. An article from The Independent newspaper states The Indian government hopes to remedy this situation, which affects 112,000 rural villages across the country, over the next decade. The solution is a combination of light-emitting diodes (LEDs) and solar power. The former are more efficient than light bulbs the power required to light one conventional 100W bulb can now light an entire village and the latter allows electricity to be stored in batteries and provides lighting where there is no grid supply. Both LEDs and solar panels can also take the rough and tumble of village life: having few moving parts, they are very durable. (Independent, 2006) It is evident to see from this statement that the progress of utilising light from LEDs is positive; however this is not something that can be generalised to a greater population at this current time due to economics. A journal published from the Philips Research Centre shows an experiment on LED light sources and modelling for practical control systems for LEDs. (Subramanian Muthu, 2002) states The recent improvements in high-power light emitting diodes (LED) technology with 100+ lumens per LED chip and efficacy exceeding that of incandescent lamps brings the solid-state lighting close to a reality. An LED light source made of Red, Green and Blue (RGB) LEDs can provide a compact light source with unique features such as instant colour variability. In this paper, we highlight the issues that introduce the variability in the colour point and present feedback control schemes to overcome these problems. (Subramanian Muthu, 2002) The journal concluded with: RGB-LEDs have enormous potential in lighting applications. The major issue to be resolved is control and maintenance of the white point. This issue arises from the variation in LED wavelength and lumen output with temperature, drive current and time. Further complications arise due to the wide spread in the performance parameters of nominally identical LEDs. In this paper we have presented solutions to these issues using electronic feedback control of the light output of the LEDs. (Subramanian Muthu, 2002) A journal on Fundamental Analysis for Visible-Light Communication System Using LED Lights states LED is more advantageous than the existing incandescent in terms of life expectancy, high tolerance to humidity, low power consumption, and minimal heat generation lighting Our group has proposed and optical wireless communication system that employs white LEDs for indoors wireless networks (8)-(11). (Nakagawa, 2004) The journal concludes In visible-light communication system, the LED lights are distributed within a room and the irradiance of light is wide for function of lighting equipment. Therefore, the intersymbol interference depended on the data rate and the FOW of receiver.   (Nakagawa, 2004) A technical report on Energy Savings Estimates of Light Emitting Diodes in Niche Lighting Applications from the U.S. Department of energy focuses on the energy performance of LED lighting systems within different sectors such as, residential lighting, traffic lighting, retail lighting and office under shelf lighting. the document states that A type of task lighting, LED office undershelf lighting systems have been introduced on the market as replacements for T12 and T8 fluorescent products used in the commercial offices. LED office undershelf lights have the potential to save 1.37 TWh/yr if the entire market shifted to 2007 LED technology, equal to 14.8 TBtu/yr of primary energy consumption. This amounts to about 20% of the annual consumption of one large (1000 MW) electric power plant or the annual electricity consumption of one hundred thousand U.S. households.(U.S. Department of Energy, 2008 pp. 50) The report also states that fluorescent lamps, T8s, and T12s are the types of lamps that are commonly used in an office environment. These fluorescent lighting systems have a fixture efficiency of less than 40%.   This follows on to the average number of hours artificial lights operate for. Office undershelf lighting systems operate for an average of 2000 hours per year, amounting to about 5.5 hours per day or 8 hours per work day. (U.S. Department of Energy, 2008 pp. 51) This would bring on maintenance costs for the building owner due to bulb replacements. The life span of LED lighting systems is far greater than fluorescent lamps, which in turn would reduce regular maintenance. The annual energy comsuption for 53 million office undershelf lighting systems consume 3.43 TWh/yr of electricity in the U.S. At the moment LED lighting systems are still new to the market and have not penetrated the market enough to calculate the actual energy savings; however LED lighting systems have the potential to save 1.37 TWh/yr of electricity if LED lights completely replaced fluorescent lighting systems. (U.S. Department of Energy, 2008 pp. 52) (DiLouie, 2006) Points that LEDs are solid state devices that produce light by passing a current through semiconductor chips which are housed in a reflector, which is Development of Sustainable LED Lighting for Offices Development of Sustainable LED Lighting for Offices CHAPTER 1 INTRODUCTION 1.1: Study Background Climate change is rapidly increasing in our environment due to an increase in gases such as carbon dioxide and methane produced by humans and animals in the Earths atmosphere. As humans we have a moral responsibility to control and save the environment. The built environment is one of the major impacts towards greenhouse gas emissions. Designers are now pressured to design sustainable buildings that have less impact on emissions that damage the environment. The term sustainability means to save natural resources for future generations. Many buildings indirectly use resources such as fossil fuels which are converted into energy. Lighting systems in buildings consume some of this energy. Lighting accounts for around 15% of the energy bill in most homes, and around 25% in commercial buildings. It is supplied by electrical power plants using fossil fuels, and is responsible for a significant percentage of carbon dioxide emissions (Marshall 2009) To help combat how we as consumers use electric lighting an alternative can be achieved via sustainable lighting. Sustainable lighting can be defined as, Lighting that meets the qualitative needs of the visual environment with the least impact on the physical environment. (Service Lamp Corp. 2001) Light is an electromagnetic radiation, which means it is partially electric, magnetic and radiates.   Light starts off from atoms (electrons that orbit the nucleus). When energy is absorbed by an atom the electrons shift up to a bigger orbit. When the atom loses the energy the electrons shift back down to the original orbit, while the electrons shift back down they emit light in the form of electromagnetic radiation. (Sarlina 2009) This document will review material on lighting systems in the office environment. The document will start with a brief history of the light bulb and then go on to how humans interpret light. The document will discuss how LED technology would be utilised more in offices and discuss the importance of migrating to LED lighting systems in offices for a more sustainable environment. The thesis will include three known case studies on LED lighting installed in offices to gather and compare data in order to evaluate how LED lighting would suffice in real life environments. 1.2: Brief History The history of modern lighting starts off with the invention of the arc light in 1810 by Humphrey Davy. This worked by connecting a battery to a strip of charcoal using two wires. The strip of charcoal was charge with electricity and glowed. (Jacks 2003) In 1820 Warren De La Rue used a piece of platinum placed inside a tube.   A current was passed through the tube and the platinum lit well but the bulb did not go into production because platinum was very expensive. (Jacks 2003) A chemist and physicist Joseph Wilson Swan produced a workable electric light in 1860 which he patented as an incandescent light bulb with a filament made from carbonised paper within a partial vacuum. J. W. Swan improved on the invention in 1875 he changed the filament to a compressed and carbonised fibrous cotton thread filament. (Jacks 2003) An inventor called Thomas Alva Edison bought Josephs Swans patent from a company who owned the patent.   Thomas Edison worked on the light bulb to increase the life span. In 1880 Thomas Edison invented his Bamboo fibre filament lamp which lasted for 1200-1500 hours. (Jacks 2003) In 1903 Willis Whitnew invented the tungsten filament lamp (commonly used today). The tungsten lamp had a carbon filament with a metal-coating. This stopped the problem with the bulb turning dark as Thomas Edisons bulb did. (Jacks 2003) Technology today has advanced to new methods of lighting. Light emitting diode (LED) technology is now at the centre point of attention as LED lighting has many advantages with being very energy efficient, long lasting and produces less heat compared to standard incandescent or halogen bulbs. 1.3: Dissertation Structure The dissertation is divided into a sequel of five chapters. The first chapter focuses on climate change and the need to for a more sustainable built environment, a brief history into the light bulb, aims and objectives of this dissertation and the logic behind the dissertation. Chapter two is a detailed literature review which focuses on the effects of lighting on building occupants followed by government legislation, then comparing different types of lighting and leading onto research on LED technology. The information gathered is sourced from websites, government documents, books and scientific journals. Chapter three follows on from the literature review. This chapter focuses on the structure for the dissertation; firstly explaining the reason for using a literature review and then drawing on three major case studies have been chosen and all cases deal with LED lighting systems within office spaces. From the case studies the author has analysed and interpreted information.   The primary data gathered will be in the form of a qualitative questionnaire sent to lighting experts (via email) who have been involved with the case studies. The Answers have been analysed and compared to get a wide knowledge from accredited professional opinions. The fourth chapter researches into the three chosen case studies, all case studies are analysed and compared to give an overview of how effective having an LED lighting system is in an office environment. The fifth chapter discusses the results gathered from the findings. This would give an overview to the dissertation and show the key findings into answering the key questions. The final chapter will draw up conclusions as to the impact of LED lighting in office environments. The chapter addresses the original research question in the context of the findings and provides final conclusions on LED lighting and making use appropriate references where necessary. 1.4: Aim and Objectives The author has chosen sustainable LED lighting as the subject area in this dissertation. The question the author would like to propose will be: Why arent there enough office buildings using LED lighting systems? Also what effects do LED lighting have on users working in an office environment; would LEDs be beneficial for health and comfort on a psychological basis? To address the question the author will explore this main aim: The aim of this study is to research into the sustainability of LED lighting systems and how lighting can affect building users within an office environment. The author will aim analyse case studies on LED lighting systems in offices. What are the advantages and disadvantages? How would an LED lighting system be best suited for the office environment in terms of efficiency, comfort, reliability and short long term costs? The author will interview people from case studies drawn to gather primary qualitative information to reach a final conclusion. The actions the author will take to help answer the research question are listed below: Literature review, take into account of the building regulations, effects of artificial lighting on building occupants, types of artificial lighting and researching into books, case studies, reports, journals and websites related to LED lighting and other sustainable lighting systems. Research case studies on LED lighting systems that have been installed in offices. This would give the author an insight on how LED lighting systems have been successful in a real life environment. Interview researchers from case studies. Ask questions about how LEDs are designed to fit in a working office environment. Any issues that have occurred within the buildings. 1.5: Hypothesis In the United Kingdom there are very few offices if any that use an LED lighting systems to light up an office space. This could be due to lack of awareness, economic climate, social environment and lack of technology available to solve prob lematic conditions. 1.6: Key questions 1. How does light effect building users in terms of health? 2. How would LED lighting benefit offices and the environment? 3. Why isnt there many offices using LED lighting systems? 4. What is the current market like for LED lighting? Would there be a future for more LED lighting in offices? CHAPTER 2 LITERATURE REVIEW 2.1: Introduction This chapter researches into the effects of lighting on buildings occupants, legislation, different types of lighting and LED technology in detail. The aim for this literature review is to obtain information on how light is transcribed in the circadian system and the effects of light on human health. Legislation is a key issue for lighting. it regulate on the amount of light required for the appropriate tasks usually attained in different buildings, by learning legislation it would give the author an understanding into what requirements an office would need for good lighting. All information collated are from secondary and tertiary sources; for this literature review the information is found in books, journals, web pages, and government documents. 2.2: Effects of lighting on building occupants Lighting affects all building occupants on the way they perform tasks. There are different levels of lighting in different environment; the colour of light used in offices would tend to have a blue-white colour to promote concentration and light used in public areas would be a warmer yellow colour so building occupants would feel more relaxed in this type of environment. Too much light can cause health problems such as increased stress levels, headaches and higher blood pressure to the building occupant. (H.E.S.E, 2009) (Boyce, 2003 pp. 160) stated that Most apparently visual tasks have three components; visual, cognitive, and motor. Every task is unique in its balance between these components and hence in the effect lighting conditions have on task performance. (Boyce, 2003 pp. 160) also stated that Lighting conditions can affect task performance throught three systems, the visual system, the circadian system, and the perceptual system. the impact   of lighting conditions on the visual system and hence on visual performance is determined by the size, luminance contrast, and colour difference of the task and the amount, spectrum, distrbution of the lighting. The point that   (Boyce, 2003) makes is that light sent to the visual system affects the performance of the information relayed in the brain.   (Cuttle, 2008 pp. 5-6) stated The optical system of the human eye focuses an inverted image onto the retina, shown in Figure 1. This image is constantly changing with movements of the head and the scanning movements of the eyes. It is often said that the eye is like a camera, but the only similarity is that it forms a focused image in which, for every pixel, there is a corresponding element in the luminous environment. The distribution of luminance and colour that comprises the retinal image is modified by light losses that occur in the optical media of the eye, and these losses are not constant as they increase significantly with age. (Cuttle, 2008) Both books express points about how light is interpreted in the human brain differently but they both correlate how light can affect a building occupant. They both state how light is interpreted in the visual system. A research journal on Light Much More Than Vision written by Mark. S. Rea (Ph.D.) Discuses how lighting can affect the circadian system in building occupants. The journal questions if offices, school and homes are providing good lighting practises. The journal begins with an abstract on the impact of light on the circadian system The amount of light, its spectral composition, spatial distribution, timing and duration needed for vision is so different from that needed for circadian functioning, that generalizations about good lighting will have to be assessed by two very different sets of criteria in the future. (Mark. S. Rea, 2007) The journal continues on how light is interpreted in the human circadian system Light is presently and formally defined as optical radiation entering the eye that provides visual sensation. An international system of photometry has been developed and institutionalized to quantify, measure and communicate the properties of light as it affects the human vision. (Mark. S. Rea, 2007) This statement explains how light is communicated in human vision.   Practical sources of light allow humans to read material, move around spaces, drive cars, create social interaction between other users and allow user to do other activities. Under spatial distribution the journal states Through optical refraction by the cornea and lens in the eye and by neural-optical enhancements by in the retina, the spatial distribution of objects and textures in the environment can be processed by the visual system. Arguably accurate rendering of the spatial distribution of light in our environment by our retina is essential to our survival because   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   patterns of light and dark provide information needed by the visual system (Mark. S. Rea, 2007) The journal concludes with So, Are we providing healthy light in our offices, schools and homes? Probably the answer is No, we are not. Certainly we are not providing or specifiying the ideal lighting technologies and applications for the circadian regluation (Mark. S. Rea, 2007). This would bring on the question as to wether LED lighting would provide the answer to good lighting. LED has been evolving for years, they have been specifically modified to provide comfortable lighting levels for which a user could carry out certain visual functions. 2.3: Legislation The Kyoto agreement is a protocol made by the United Nations Framework Convention on Climate change. This main aim of the protocol is to stabilise greenhouse gas emissions. There are four greenhouse gases that the protocol focuses on (carbon dioxide, nitrous oxide, methane, sulphur hexafluoride). The United Kingdom Government is legally tied to the Kyoto agreement and has set out targets to meet emission rates. A document on The Kyoto Protocol by British-Energy states The UKs commitment under the protocol is for a reduction in greenhouse gas emissions of 12.5% from 1990 levels by 2008-2012. This implies an 8% reduction in CO2 emissions over this time period. The UK government also has an aspirational target for itself of a 20% reduction of CO2 emissions by 2010, demonstrating the importance of this issue for the current government.(British Energy, 2009) Offices contribute towards the CO2 emissions given off around the planet. A lot of the energy used in offices is mainly caused by office lighting. The new advancements in LED lighting could reduce the amount of energy used because LED lighting is the most sustainable type of artificial lighting. This could help aid the efforts of the Kyoto Protocol and help meets emission targets. Approved Documents Part L of the building regulations is split up into four documents. Part L1A and L1B focuses on conservation of fuel and power in domestic buildings, part L2A and L2B focuses on conservation of fuel and power in non domestic buildings. As of 6th April 2006 the revised Building Regulations Part L Conservation of Fuel and Power came into effect. The updated regulations would improve energy standards by 40 percent from that of the 2002 Building Regulations (ODPM, 2006). There are four approved documents published by the Office of the Deputy Prime Minister (ODPM, 2006): Approved Document L1A: Conservation of fuel and power (New dwellings) (2006 edition) Approved Document L1B: Conservation of fuel and power (Existing dwellings) (2006 edition) Approved Document L2A: Conservation of fuel and power (New buildings other than dwellings) (2006 edition) Approved Document L2B: Conservation of fuel and power (Existing buildings other than dwellings) (2006 edition) L1 Domestic buildings Conservation of fuel and power in dwellings. Limiting heat loss through fabric of dwelling from hot water pipes used for space heating. Limiting heat loss through hot water vessels and service pipes. Use control systems on space heating and hot water systems so that energy can be used efficiently. Use control systems on lighting systems so that energy can be used efficiently. L2 Buildings other than dwellings Conservation of fuel and power in non domestic buildings. Limiting heat loss through fabric of dwelling from hot water pipes used for space heating. Limiting heat loss through hot water vessels and service pipes. Use control systems on space heating and hot water systems so that energy can be used efficiently. Providing lighting systems with sufficient controls so that energy can be used efficiently. Limiting exposure to solar heat gains. Use control systems on air conditioning and mechanical ventilation systems so that energy can be used efficiently. Commissioning the building engineering services so that they make efficient use of energy and recording their performance. Approved Document L2A: Conservation of fuel and power highlights what is required for lighting efficiency in offices, industrial and storage areas in all building types. The document states For the purposes of this Approved Document, office areas include those spaces that involve predominantly desk-based tasks, including classrooms, seminar rooms and conference rooms, including those in schools. Reasonable provision would be to provide lighting with an average initial efficiency of not less than 45 luminaire-lumens/circuit-Watt as averaged over the whole area of these types of space in the building. (ODPM, 2006 pp. 19) LED lighting has the potential to excel past the average guide for initial efficiency of 45 lumens per watt. A breakthrough from the lighting company CREE states LED efficacy test results that set a new benchmark for the LED industry. Cree reported results of 131 lumens per watt white LED efficacy, confirmed by the National Institute of Standards and Technology in Gaithersburg, Maryland. Tests were performed using prototype white LEDs with Cree EZBrightâ„ ¢ LED chips. (CREE Inc, 2009) The CIBSE Lighting Guide 7: Office Lighting gives a guidance of how to layout lighting systems within an office to give the maximum efficiency of lighting and how much light is required for different types of office spaces. The guide states There are many ways to light an office space: with direct light down from above, from indirect light bounced from the ceiling, or from a combination of both. Many factors will dictate or influence the choice of which technique to use.   (Ruffles, 2005 pp. 7) There are many different building types and each office would need a lighting system that is individually specified. There are different types of lighting systems that give off different light intensities. The lighting guide states that a typical office space would need 500 lux (illuminance) for building users to take on paper-based or mixed tasks comfortably and 300 lux for any screen-based work. (Ruffles, 2005) Figure 2 shows the required amounts of light need for building user to work within different types of offices spaces, taken from the office lighting guide. The figures suggest that each typical office space would need 300 lux for screen based tasks, normal meetings and reception administrative tasks and 500 lux for more intense tasks such as paper-based, reading documents and writing. In a more deep-plan area the office space is required to have 500-750 lux throughout to perform multiple tasks comfortably. This is due to the fact that deep-plan areas are more towards the middle of office spaces or more than six meters away from windows; they would require a more constant flow of artificial light. This is where LED lighting may be at best because of the amount of electricity LED lighting systems take are very minimal and could deliver the required amount of light depending and the type of fixture. In normal deep-plan areas artificial lighting systems are on for longer periods because natural lighting coming in from windows would not penetrate throughout the office spaces. The corporation Philips suggests that a higher powered LED light would deliver up to 220 lumens. This type of LED would typically consume four watts. A typical deep-plan office space would require three high powered LED lights to deliver a comfortable amount of light for a user to perform various tasks, which would still consume less electricity compared to other office lighting systems. 2.4: Types of lighting There are many types of lamps that are currently used in different environments. These lamps include the incandescent lamp, compact fluorescent lamp, fluorescent lamp, halogen lamp, metal halide lamp and light emitting diodes. Incandescent lamps An incandescent lamp is a glass (See figure 3) bulb containing a thin filament. A current is passed through the filament, which heats up the filament until light is produced. (Philips, 2000 pp.49-50) stated The earliest filament lamps as developed by Swan in the United Kingdom and Edison in the United States had a short life of only 150 hours and a low efficiency of 2.5 lumens per watt, but they were thought of as a magic light source to replace gaslight. Filament lamps were clean, had greater flexibility, better colour and, with the development of available sources of power, better long-term economics. Now, a century later, the light bulb is still the preferred lamp for domestic use due to its cheap cost. Phillips (2000) continues to state that The life of a filament lamp depends upon its light output, with a greater output giving a shorter life. A life of 1000 hours with a light output of 12/14 lumens per watt was established as being a reasonable compromise and one which has stood the test of time. (Bean, 2007 pp. 139) explains that a compact fluorescent lamp is the introduction of smaller diameter tubes using high efficiency triphosphors bought with it the posibility of folding the tubes to produce compact single ended lamps. A 12W compact fluorescent lamp gives the same output as a 60W tungsten GLS lamp. Fluorescent Lamps (Fielder, 2005 pp. 28) states that Fluorescent lamps are built using a tubular glass envelope coated on the inside with a mix of phosphors. Inert Gas and a small amount of mercury is introduced into the tube to provide the atoms for photoluminescence. the tube is slightly pressurized, and the ends of the tube are capped with electrodes, which contain a cathode to generate and arc. Fluorescent lamps are 8 times more efficient than incandescent lamps and have a long life span, but fluorescent lamps contain mercury shown in figure 5. Mercury in lamps is harmful for the environment if not disposed of appropriately. Halogen Lamps The Interior Lighting for Designers book articulates that The tungsten-halogen   (or halogen)   lamp is an incandescent lamp with a selected gas of the halogen family sealed into it. As the lamp burns, the halogen gas combines with tungsten molecules that sputter off the filament and deposits the tungsten back on the filament   (Gordon, 2003 pp. 73). Figure 6 below shows an example of what a typical halogen lamp looks like. Metal Halide Lamps Metal halide lamps produce white light of a good colour quality and are available in many sizes, from compact lamps that can be used in track lighting and table lamps to huge lamps for lighting stadiums. Standard metal halide lamps tend to have a colour temperature of 3700 to 4100K and appear cool and slightly greenish. Their CRI is 65 to 70. Standard metal halide lamps typically are used where colour is not critical, such as sports arenas, parking lots, landscape lighting, and building floodlighting. (Benya, 2004 pp. 9-10) Light Emitting Diodes (LEDs) An LED is a semiconductor device that emits light when a voltage is surged through the semiconductor.   LED solid-state lighting is becoming more in use because of the energy saving benefits and long term costs. The main types of light bulbs used in offices are fluorescent lamps, incandescent tungsten filament (halogen lamps) and metal halide lamps. Fluorescent lamps are the main types of light sources used in offing lighting; the table states that the fluorescent tubes has a lamp efficiency of 32-86 Lm/W (Lumens per watt) this has a higher efficiency compared to incandescent tungsten filament lamp which have an efficiency of 7-14 Lm/W. Also fluorescent lamps can last more than ten times longer than incandescent tungsten filament lamps, but the tungsten filament lamps has a colour rendering index of 99 which means that the light intensity is much higher and would provide light that is closer to natural daylight compared to fluorescent lamps. Tungsten lamps are mainly used for executive offices to give an office a more professional looking environment. Metal halide lamps are used for desk lamp for more detailed important task where more light may be required for analytical reading and writing /complex drawing tasks. 2.5: LED technology LED technology is a fast growing lamp replacement solution in the lighting industry. LEDs contain semiconductors which are atoms of arsenic, phosphorus, germanium or other elements found in the periodic table. When electricity passes through the semiconductor visible light is emitted. Placing a number of LEDS side by side increases the increases the strength of the brightness. LED lights are also dimmable so the user could control the light intensity in a given area. The advantages of using LEDS are that they have a 50,000 to 100,000 hour life span, they consume very little electricity, they instantly light up, LED lights do not emit UV rays, they are durable to   vibrations they do not contain any mercury and LED emits light from any part of the light spectrum. The disadvantages of using LED lighting are that light is distributed directly instead of evenly compared to incandescent and fluorescent bulbs; it is very expensive to buy LED lights, they could cause light pollution in an environment because LEDs produce a lot of white light and LEDs are sensitive to heat. LED lighting is still currently being researched today to find out better methods to utilise the light from LEDs. An article from The Independent newspaper states The Indian government hopes to remedy this situation, which affects 112,000 rural villages across the country, over the next decade. The solution is a combination of light-emitting diodes (LEDs) and solar power. The former are more efficient than light bulbs the power required to light one conventional 100W bulb can now light an entire village and the latter allows electricity to be stored in batteries and provides lighting where there is no grid supply. Both LEDs and solar panels can also take the rough and tumble of village life: having few moving parts, they are very durable. (Independent, 2006) It is evident to see from this statement that the progress of utilising light from LEDs is positive; however this is not something that can be generalised to a greater population at this current time due to economics. A journal published from the Philips Research Centre shows an experiment on LED light sources and modelling for practical control systems for LEDs. (Subramanian Muthu, 2002) states The recent improvements in high-power light emitting diodes (LED) technology with 100+ lumens per LED chip and efficacy exceeding that of incandescent lamps brings the solid-state lighting close to a reality. An LED light source made of Red, Green and Blue (RGB) LEDs can provide a compact light source with unique features such as instant colour variability. In this paper, we highlight the issues that introduce the variability in the colour point and present feedback control schemes to overcome these problems. (Subramanian Muthu, 2002) The journal concluded with: RGB-LEDs have enormous potential in lighting applications. The major issue to be resolved is control and maintenance of the white point. This issue arises from the variation in LED wavelength and lumen output with temperature, drive current and time. Further complications arise due to the wide spread in the performance parameters of nominally identical LEDs. In this paper we have presented solutions to these issues using electronic feedback control of the light output of the LEDs. (Subramanian Muthu, 2002) A journal on Fundamental Analysis for Visible-Light Communication System Using LED Lights states LED is more advantageous than the existing incandescent in terms of life expectancy, high tolerance to humidity, low power consumption, and minimal heat generation lighting Our group has proposed and optical wireless communication system that employs white LEDs for indoors wireless networks (8)-(11). (Nakagawa, 2004) The journal concludes In visible-light communication system, the LED lights are distributed within a room and the irradiance of light is wide for function of lighting equipment. Therefore, the intersymbol interference depended on the data rate and the FOW of receiver.   (Nakagawa, 2004) A technical report on Energy Savings Estimates of Light Emitting Diodes in Niche Lighting Applications from the U.S. Department of energy focuses on the energy performance of LED lighting systems within different sectors such as, residential lighting, traffic lighting, retail lighting and office under shelf lighting. the document states that A type of task lighting, LED office undershelf lighting systems have been introduced on the market as replacements for T12 and T8 fluorescent products used in the commercial offices. LED office undershelf lights have the potential to save 1.37 TWh/yr if the entire market shifted to 2007 LED technology, equal to 14.8 TBtu/yr of primary energy consumption. This amounts to about 20% of the annual consumption of one large (1000 MW) electric power plant or the annual electricity consumption of one hundred thousand U.S. households.(U.S. Department of Energy, 2008 pp. 50) The report also states that fluorescent lamps, T8s, and T12s are the types of lamps that are commonly used in an office environment. These fluorescent lighting systems have a fixture efficiency of less than 40%.   This follows on to the average number of hours artificial lights operate for. Office undershelf lighting systems operate for an average of 2000 hours per year, amounting to about 5.5 hours per day or 8 hours per work day. (U.S. Department of Energy, 2008 pp. 51) This would bring on maintenance costs for the building owner due to bulb replacements. The life span of LED lighting systems is far greater than fluorescent lamps, which in turn would reduce regular maintenance. The annual energy comsuption for 53 million office undershelf lighting systems consume 3.43 TWh/yr of electricity in the U.S. At the moment LED lighting systems are still new to the market and have not penetrated the market enough to calculate the actual energy savings; however LED lighting systems have the potential to save 1.37 TWh/yr of electricity if LED lights completely replaced fluorescent lighting systems. (U.S. Department of Energy, 2008 pp. 52) (DiLouie, 2006) Points that LEDs are solid state devices that produce light by passing a current through semiconductor chips which are housed in a reflector, which is

The Lion, The Witch, and The Wardrobe - C.S. Lewis :: Lion Witch Wardrobe Essays

The Lion, The Witch, and The Wardrobe - C.S. Lewis The main characters in this story are Peter, Susan, Edmund, and Lucy. During a war in London they were sent to a professor's house outside London. Lucy, while exploring with her brothers and sister, found a secret passage through the wardrobe to Naria,a secret world. In Naria there are other characters. One of them is the White Witch,also known as the Queen of Naria, who was like a tyrant. If anyone disobeyed her she turned them to stone. Another character Aslan, a lion, saved Naria from the rule of the White Witch. Most of this story takes place in Naria. The main conflict is how Naria can live under the rule of the White Witch. The Beavers set out to take Peter, Susan, and Lucy (not Edmund because he went to the witch ) to the four thrones so they ( four children united ) can rule over Naria and destroy the witch. The Beavers and the three children were walking in the snow because there it was always winter. Although it was always winter Christmas never arrived. After they awoke th e next day they saw Father Christmas who gave them gifts.Mrs. Beaver received a new sewing machine. Mr. Beaver's dam was fixed and finished. Peter was given a shield and sword. Susan received a bow, arrows, and a horn. Lucy's gift was a bottle of healing juice and a dagger. that was the climax of the book because the spell of the White Witch was fading. Then they met up with Aslan and he freed all the stone figures and made them his army. The resolution of the book is when Aslan's army and the witches army confront and Aslan's army wins. Peter kills the witch at the end of the battle. The impression I got from this book is that Naria is a land of surprises and I'm excited that this years assignment will allow me to read more of " The Chronicles of Naria " .