CSS Styles and Web Design Essay Example for Free

CSS Styles and Web Design Essay Cascading Style Sheets (CSS) defines how HTML elements are to be displayed and in-short referred as CSS. It controls the appearance of multiple HTML pages by just including one single external style sheet. For storing external style sheets CSS files (â€Å". css† extension) are used. CSS-based layouts along with table based layouts are used to manage the formatting of a web site. Cascading style sheets (CSS) make it easy to manage the formatting of a web site and it can be used to control the appearance of objects on a page or throughout a site. It can be designed and redesigned, and can control the formatting of hundreds of pages, including fonts, link colors, margin settings and background images. It is widely supported by modern browsers and allows flexibility in positioning. CSS based layouts Keeps the HTML/text ratio at a low level thus decreasing load time and Allows the display of main content first while the graphics load afterwards. CSS also avoid accessibility issues raised by table cells and the content flows logically without disruption. The three ways by which style can be added in HTML document are: 1. External style sheet 2. Internal style sheet (inside the head tag) 3. Inline style (inside an HTML element) In terms of priority when HTML document displays, it first looks for Inline style, than for internal style sheet (inside the head tag) and at last include External style sheet which is CSS. External style sheet (CSS) enables developer to change the appearance and layout of all the pages in their WebPages by just editing one single CSS file. Internal (embedded) style sheets are useful for managing single HTML page in which it is included and inline style sheet are used for managing some special formatting within the webpage. The Evolution of HTML Standards The evolution of HTML standards started from 1989, when Tim Berners-Lee invented the Web with HTML as its publishing language. In September 1991, Open discussion about HTML across the Internet begins. In 1992, HTML 1. 0 the first release of HTML to the world, was taken from Tim-Berners Lee original proposal. At this time not many people were involved in website creation and the language was very limited. In May 1994, HTML+ having some physical layout was shown at the first World Wide Web conference (W3C) that was held in Geneva. In July 1994, HTML specification for HTML 2. 0 was released. It included everything from HTML 1. 0 and added a few new features and defined many core HTML features for the first time. It was HTML standard until January 1997. In March 1995, HTML 3. 0 published as an Internet Draft by a HTML working group, led by Dave Raggett. In 1996, HTML 3. 2 (wilbur) came after the end of the Browser Wars and became the official standard in January 1997. It had included the tags introduced by Netscape and Microsoft during Browser Wars. In December 1997, HTML 4. 0 (cougar) introduced with HTML’s new supporting presentational language, cascading style sheets and became the official standard in April 1998. HTML 4. 0 was revised and corrected and later introduced as HTML 4. 01 in 1999. In January 2000, XHTML 1. 0, an XML version of HTML 4. 01, became joint standards along with HTML 4. 01. In XHTML 1. 0, there are not many new or deprecated tags and attributes but it was changed with a view of increased accessibility and functionality and a new set of coding rules. In 2001, XHTML 1. 1 with some modularization came. In 2002, XHTML 2. 0, which is more simplified and generalized standards, came into effect for WebPages. References: CSS Tutorial available at http://www. w3schools. com/css/css_intro. asp accessed on 27 July 2007. Web Development Series: formatting content, January 4, 2007 retrieved on 27 July 2007 from http://academictech. doit. wisc. edu/ORFI/wds/index. htm Moller, A. Schwartzbach, M. L. 2006. HTML and Web Pages: An Introduction to XML and Web Technologies, Addison-Wesley. Retrieved on 27 July 2007 from http://www. brics. dk/ixwt/html. pdf Shannon, R (n. d. ). The History of HTML Retrieved on 27 July 2007 from http://www. yourhtmlsource. com/starthere/historyofhtml. html http://www. w3. org/ accessed on 27 July 2007.

The Importance Of Water Treatment

The Importance Of Water Treatment Water is very important for human being and other living things. In human body, more than 70% are fluid such as blood and all these fluid are basically formed by water. Bone marrow needs water to generate blood then blood carries the oxygen from lung to whole body. Besides that, water can maintain humans body temperature and provide natural material with mineral. Water is not only essential for human body, it is also playing an important role in our daily life activities, examples like washing clothes and food, bathing for personal hygiene and acting as solvent for all cleaning reagent. Consequently, water industries refer to a problem solver in this situation. First of all, water industries are divided into three major types which are water purification, wastewater treatment and also the new type called desalination. For the water purification means purifying water to become the drinking water. Although natural water is drinkable for human but without any purification or method of killing gem, the natural water is harmful for human being nowadays. Purified water and natural water seems like no different when we look at it but sometimes we still smell the different, natural water might have some pungent smell. Natural water consists of a lot microorganism and bacteria inside it, just we cant observe it with our naked eyes. In addition, water pollution is getting serious thus purification is necessary to ensure the drinking water is clean and not harmful to our health. After that, another type of water industry which is very vital for the Mother of Nature is the wastewater treatment industry. Wastewater treatment refers to the processes of controlling the wastewater on Earth; this is the most important method to solve the water pollution. Wastewater is directing to the chemical wastewater from factories, wastewater from household and some water from polluted river or lake. The usage of wastewater treatment is to killing the gem/bacteria in the wastewater; remove solid impurities and odor smell. Irresponsible human behavior will make the wastewater treatment become more essential for the world. The new type of water industry is about the desalination. Desalination is a meaning of transforming the seawater or saltwater into pure water or drinking water. Due to the natural water on the land is getting lesser and the population of human is increasing, hence we found out a new method to produce normal water from seawater. Seawater source is so much on Earth, so this method is highly developing around the world. Seawater cannot consume by human because it consists of high salt component such as NaCl, this cause our body unaffordable to consume the seawater. Furthermore, we will discuss deeply about the process of water purification and desalination in this article. The importance of Desalination and water purification industry Water treatment process brings many importances to the society today. One of the importances of water treatment process is to ensure that water is more suitable to be used by industries and individuals. The purpose of water treatment process is to remove contaminations from water, so that it would be more suitable for it to be used. There are several processes that can be used to treat water such as filtration, disinfection that is majorly in use to clean water. Water is the key to a persons survival because without water survival is simply not an option. Hence, it is important to make sure water is purified in order to drink otherwise bacteria in the water can be harmful to your organs if drunk in normal consumption. According to a global research, a large number of people at their early ages die from water born diseases in most of the developing countries. Thus, it is very important to get the proper treatment of the water for a healthy living. Water treatment industry can be very helpful for the society today because they are saving the lives of many innocent human beings who die from fatal diseases such as cholera, typhoid which cause by consuming contaminated water. According to United Nations statistics, the worlds fresh water consumption since the 20th century increased by 6-7 times higher than the population growth rate of two times, around 1.4 billion people lack access to safe and clean drinking water, or an average of every 5 people who have a lack of water. So, the idea of desalination plays a major role to provide us the constant supply of water as the sea water is an unlimited resource. Sea water desalination process is actually done by converting salty sea water into fresh usable water. Further purification of the sea water after the desalination process can convert it into drinking water. These industries are important to ensure that there is enough water supply as the population is growing and growing rapidly. These are the major roles of the water treatment plants in. Water supply and demand Water is one of the most important resources in our life and it is the major Earths natural resources. However the freshwater supply in our earth is a control resource, which means the total amount of freshwater, is limited. Most of the worlds water supply is saltwater stored in the oceans. Converting saltwater to freshwater is generally too expensive to be used for domestic, industrial and other freshwater uses. About 97% of the water stored in the ocean is salt water. Only 3% of the worlds water supply is a freshwater where two-third out of the 3%, of that water is frozen, forming the polar ice caps, and icebergs. The remaining one-third of freshwater is available as either surface water or ground water; ground water accounts for two-thirds of this amount. Surface water is water that is visible above the ground surface, such as rivers, ponds and lakes. Ground water is water that either fills the spaces between soil particles or penetrates the cracks and spaces within rocks. The demand for water supply includes water consumption by the domestic, industrial, commercial and other sectors. In addition to this, the total amount of water that needs to be produced, and hence the total water demand includes provisions for water lost as a result of the leakages between the source (treatment plant) and the end users of consumers. Malaysia, like the rest of the world, is faced with a growing population. The population of Peninsular Malaysia will be more than double its size from 18.1 million in 2000 to 38 million in 2050 as reported in the National Water Resources Study (2000) thus the population growth and socio-economic development are currently driving a rapid increase in water demand. The government is now working on the creation of an industry structure to purified water that will ensure long-term sustainability of the water supply and sewerage services industry. Purified water is water from any source that is physically processed to remove impurities. Distilled water and deionised water have been the most common forms of purified water, but water can also be purified by other processes including reverse osmosis, carbon filtration, micro porous filtration. Prospect of water industry in Malaysia Nowadays, the water industry in Malaysia is filled of challenges. There is either too much, too little, polluted or inaccessible water to meet the needs of our nation. As the increasing of demand to the quality of life, peoples are pursuing for an abundance of safe, low cost and high quality water. Globally, more than 90% of water and sanitation systems are publicly owned and operated. However, a trend that industry experts acquired smaller utilities has been increasing. This phenomenon is called consolidation. There also was an increase in privatization-private companies that contract to operate or to purchase the public utilities. Moreover, many larger systems were investing in new testing and treatment methods. Under Malaysian conditions, erosion by water and the decay of nations of pipes that transport water into homes are the most significant. As pipes corrode, water pressure decreases and foreign materials such as bacteria and debris may enter the system. In order to reduce the negative health effects to humans, government officials flush out the water and add large doses of chlorine to eliminate contaminants. However, this is a short-term solution. Obviously, the countrys water-pipe system, much of which is over one hundred years old, needs a major overhaul. Increased privatization of the water system is being seriously considered to help alleviate the plight of countrys water as the government can receive funding for structural adjustment programs. This is because private water companies have a high potential of bringing efficiency, savings, and environmental responsibility to communities, cities and the country. Besides that, as we know that fresh water that is available for human use is just 1 percent of the total water supply, and that supply is dwindling as supply cannot keep pace with demand. Thus, the prospect of water industry may be focusing in the alternative to increase the freshwater. Since most of the earth water is seawater, desalination technology has arisen as a potential alternative to solve the problem of water shortage. Desalination has been present throughout the 125 countries and territories around the world, the worlds desalinated water to feed about 5% of the population. In fact, desalination is an excellent way to solve water shortage problems in many countries. This is indeed a strategic choice as its validity and reliability has been more widely recognized. Research indicates that the cost of producing water from desalination is often less than half that produced by the distillation method of processing water. Improvements in effienciency have led to reduce energy con sumption, cheaper processing costs and a superior product being produced. The Impact On the Environment As our world industrialised, water pollutions are getting serious. There are three main types of water pollutions caused by human activities, which are domestic sewage, industrial wastewater and agricultural wastewater. In these wastewaters, contain pathogens, detergents, toxic waste, chemical waste and heavy metals. These harmful chemicals not only poison aquatic organisms, also affect sources of drinking water, and pollute our environment. Toxic wastes, generally, are not easy to metabolise out of body of organisms. Wastes tend to bioaccumulate inside the organisms. The bioaccumulation of toxic wastes not only happen in single organism, but all members from food chains. The concentration of toxic wastes gets higher as the trophic level going up. Not only that, the agricultural wastewater contains fertilizer, pesticide and also the fungicide. These pollutants cause the eutrophication. It is caused by excessive nutrients in the wastewater, and it brings the algal blooms and red tide. These leads to fish kills as algaes consuming most of the oxygen in the water. In a nutshell, water pollution can lead to a lower biodiversity. The decrease of biodiversity means that the variation of life decreased, and it affects the balance of ecosystem. It is important to maintain the balance of ecosystem, species of organisms will decline if the ecosystem does not balance. It will be a bad circle. Water industry helps in collecting the wastewaters from different parts to the water treatment plants. Also, water industry helps in controlling the quality of water. Before discharging the wastewater back to our ecosystem, the water is treated so it reduces the effect toward the environment. It also improves the water quality which means that provides not only the better quality of life, and save the environment for the future. Furthermore, it maintains the balance of aquatic ecosystem. As the contaminated wastewater not flowing into river and the sea, the aquatic environment will be free of dangerous and toxic wastes. The world cannot stand without water industry. Water industry gives us a solution to the world, a hope to the future. Reverse Osmosis Reverse osmosis is one of the water purification method that is popular in water treatment industry. Just as its name implies, water goes on the osmosis process another way. Normally, the solvent, which is water will go through the semipermeable membrane that having many tiny pores, from low solute concentration side to the high solute concentration side. However, for the reverse osmosis, a pressure is applied on the high solute concentration part. The pressure can be drove by electricity or it may get from the pressure exchanger. Thus, water molecules are forced to pass through the membrane to the low solute concentration side. By this way, clean water can be collected on the other side. There are three common membrane materials, which are polyamide thin film composites (TFC), cellulose acetate (CA) and cellulose triacetate (CTA). In generally TFC membranes are stronger and more durable among these three membranes. CA and CTA give a better toleration to chlorine. For different purpose, specified membrane will be used. Reverse osmosis can be used in residential, commercial and industrial water filtration, also the seawater desalination. By this method, impurities in the water can be removed to clean water. These impurities include ions, volatile organic compounds (VOCs), pesticides, and salts. This is because those impurities are larger than than the pores so they cannot pass through it. Water molecules are allowed to pass through the membrane as it is small enough. Impurities,yet will be left behind the membrane. The waste streams flow out and the pressure is high. Later, the streams go through the pressure exchanger to transfer the waste pressure to the low pressure fresh feed. Then, the low pressure fresh feed will be pressurised. The recycle of waste pressure can save the cost of running the reverse osmosis system. The water flowed out is now clean and ready for purpose of drinking or other uses. Coagulation, flocculation and sedimentation Natural and waste water include small particulates. Coagulation and flocculation processes are intended to form particles large enough to be separated. The small particulates are suspended in water forming a colloid. The particles with the same charge repel with each other and this prevents them from combining into larger particulates to settle. Thus, some chemical and physical techniques are applied to help them settle. The phenomenon is known as coagulation. To assist in the removal of colloidal particles from suspension, chemical flocculation is required. The process water will then enter a flocculation chamber, where further chemicals may be added depending upon the raw water characteristics and the level of treatment to be achieved. Gentle mixing during this stage allows particles to agglomerate and form settleable flocs. Starch and multiply charged ions are often used. The dirty water is cleaned by treating with alum, Al2(SO4)3.12 H2O, and lime, Ca(OH)2. These electrolytes cause the pH of the water to change due to the following reactions: Al2(SO4)3.12 H2O, -> Al(aq)3+ + 3 SO4(aq)2- + 12 H2O SO4(aq)2- + H2O -> HSO4(aq)- + OH- (causing pH change) Ca(OH)2 -> Ca(aq)2+ + 2 OH- (causing pH change) The slightly basic water causes Al(OH)3, Fe(OH)3 and Fe(OH)2 to precipitate, bringing the small particulates called flocs with them and the water becomes clear. Flocculation usually follows by sedimentation, the heavy floc particles settle to the bottom of treatment tanks, allowing for their separation from the water. It works best with relatively dense particles (e.g. silt and minerals), while flotation works better for lighter particles (e.g. algae, color). A big settling tank is needed so that it takes a long time to get through. Inlets and outlets are designed so the water moves slowly in the tank. Long and narrow channels are installed to let the water to snake its way through the tank. The settled particles, sludge, must occasionally be removed from the tanks. The water is next ready to be filtered. Sedimentation is used in pre-treatment and wastewater treatment. Thermal Distillation and Electrodialysis In the process of desalination, after the reverse osmosis, it comes to the thermal distillation process. Heat is used in the thermal distillation for desalination. It boils the salt water to causes the water to vaporize, at the same time, the salt is left behind. Most of the salt is sodium chloride (NaCl). After that, the vapor will moves to a second container to condensed and collected. The boiling process of water uses up a lot of fuel to make the salt water to vaporize so many alternative processes can be considered. These processes are called multistage flash distillation (MSF), multiple effect distillation (MED), and mechanical vapor compression distillation (MVC). All these process can reduce the energy that used to boil the water with reducing the waters boiling point by decreasing the waters vapor pressure. The mechanical vapor compression distillation (MVC) is a process which evaporates the sea or saline water is derived by the heat application delivered by compressed vapor. This process able to increase generate additional amount of vapor by using the latent heat during the condensation when the vapors compression increases both of the temperature and pressure of the vapor. The multistage flash distillation is a thermal process with the low temperature of obtaining fresh water by recovering the vapor of boiling sea water in a sequence of vessels, (called effects) each maintained at a lower temperature than the last. Due to the boiling point of the water reduced as the pressure reduced, the heat energy of the vapor boiled off from one vessel is able to heat the another vessel thus only the first vessel require the heat energy from other source to heat up the sea water. Furthermore, another process of desalination process is electrodialysis that used to separate the other ions and water ions by relying on the salt ions electrical charge. In this process, the water is pre-treated by reverse osmosis thermal distillation hence then transfer to a membrane stack. Two electrodes, a positive electrode located on one side of the stack and a negative one on the other, an electrical current is conducted through the water. The ions are attracted to the oppositely charged electrodes and flow through membranes that are designed to trap either the negatively charged ions (anions) or positively charged ions (cations). Once the ions are trapped, fresh water will filtered out. Filtration Water filtration improves the overall taste of tap water, appearance and smell. Water filters are design to remove several harmful chemicals found in drinking water. At the moment, there is no better way to make sure that the water you are drinking is clean. Compare the differences between a glass of tap water and bottled water. You will realize that tap water is cloudy and it smells like bleach. There are four stages involved in water purification process: 1. Pre-Filtration -Prevents large debris from entering the System 2. Sediment Filtration 5.0 Micron Sediment Filtration 3. Carbon Block Filtration Chemical removal and 0.5 Micron Filtration 4. Ultraviolet Treatment 99.9999% Elimination of Bacteria / Virus Ultraviolet exposure of 16,000 mw/cm2 or greater Pre-filtration is the first process of water filtration, it screens the water source starting from the point of entry. These pre-filter screens are connected to the inlet hose. This is important in preventing the filtration system that turns out to be plugged with rocks, faeces, mud and other large debris. Sediment Filtration is the second stage. In this stage, the water will pass through a sediment filter. In the sediment filter it gives five micron filtration and it expands the life of the carbon filter by eliminating invisible sediments that will impulsively block the filter. Sediment filtration would include the removal of dirt, mud, sand, scale, silt and other suspended solids in the water. Carbon block filtration is the third stage of the filtration process. This process has two different processes. The first process is called mechanical straining, carbon is compressed into a solid block of material. Each molecule of water is pushed through the microscopic pores of carbon that strain out substances efficiently. The second is called chemical bonding, it uses an activated carbon which has a trivial electro positive charge added to it, making bonding agents to impurities and chemicals even more attractive. When the water is pushed through the solid carbon block, it is forced to slow down and the increased quantity of contact time with carbon allows the carbon bonding to take place. The final stage of the filtration process is the ultraviolet treatment. After the water is cleaned by the carbon filter, the next step is to expose it to an extreme dosage of UV light. The UV light it produced will destroy microorganisms by changing their DNA structure. Aeration and Disinfection Aeration is a water treatment process where water is brought into the contact with oxygen. This is to increase the oxygen content in the water, to reduce the carbon dioxide content in the water, and to remove organic compounds such as methane, hydrogen sulphide and other volatile which is responsible for taste and odour of water. These will result in good drinking pure water. High iron and manganese content in water will cause a bitter taste. Aeration is widely used for the treatment of high iron and manganese contaminants water to convert the dissolved ferrous and manganese compounds into insoluble ferric and manganese hydroxides. These can be removed by sedimentation or filtration process. There are many instruments and systems designed to aerate wastewater. These range from simple floating splashes and rotors to high-maintenance diffused air systems using membranes and complex man folding and piping layouts. These systems are designed to inject oxygen to every part of the water. The end result is better than water treatment with higher removal rates of microorganism contamination. Disinfection is an important step in ensuring that water is safe to drink, and limiting the effects of organic materials, suspended solids and other contaminants. It destroys microorganisms that can cause disease in humans. Primary methods of disinfection are chlorination, chloramines, ozone, and ultraviolet light. Other methods include chlorine dioxide, potassium permanganate, and nano filtration. Since certain forms of chlorine react with organic material naturally present in many water sources to form harmful chemical by-products. Common industrial method of disinfection is chlorination, where the chlorine gas is released to mix with water. The mixing and contact time must be provided after an injection to ensure complete disinfection of pathogens and other microorganism. Thus it kills microorganisms and it may be necessary to control the pH of the water. One chlorination had been done, the water will be finalized by some tests to make sure the water is neutral, clean and pure. Finally the water will be send to storage for the domestic, industrial, and commercial uses. Role of Chemical Engineer in the Water Treatment Industry Basically the role of a chemical engineer in a water treatment industry is mainly referring to the technical skills that the chemical engineers obtained because chemical engineers have to conduct the water treatment processes in the industry. Firstly, we talk about the role of chemical engineers before the process and industrial plant in the water treatment industry is formed. For a chemical engineer, the first mission has to do will be understood about the requirements of the water treatment industry to conduct a process with a specific industrial plant. For our case, the chemical engineer must know how to conduct a process of water purification to product drinking water. Chemical engineers must able to design an industrial plant which consists of different types of components to complete the process and get the desired product. The components that might involve in the plant are compressor, mixer, cooler, filter (separator). Furthermore, whether designing the plant, chemical engineer also may concerns about the chemical substances used within the process in the plant. The chemical substances added into the water along the process must not be harmful to consumers due to the water as output is the drinking water for human to consume. Some more, the costs for the substances and material used to build the plant and those components inside it must be save up to the lowest. Chemical engineers need to save the cost for the company and also form the product which is the drinking water with the highest efficiency. Besides that, chemical engineer has to evaluate the chemical process technology and equipment which suitable in the plant. The most important role of chemical engineer in this industry is determining the production specification. Once the plant completely designed, the most essential job that needs the chemical engineer to accomplish is establish and conduct quality control programs, operating procedures and control strategies to ensure consistency and adherence to standards for raw materials, products and waste products or emissions. When the process is running, there also something necessary for chemical engineer to provide checking for the plant and make a suitable maintenance on the processing units. Thus, chemical engineer is playing a very important character in the water treatment industry. Skills/Knowledge required by Engineer As an engineer, there are many skill and knowledge required to smoothen the task that have to conduct by engineer. The skill and knowledge required by engineer can be categories into six parts which are technical skill, computer literacy, communication skill, management/finance, international awareness and respect for diversity. Engineer requires the technical skill and knowledge to conduct and control the processing units in the plant. The technical skill is about the mathematics, chemistry, physics, mechanical and electrical knowledge. In the water industry, chemical engineers refer to separating dangerous materials from good water as a treatment train. At various stages in the multistage treatment process, unwanted constituents are separated using vacuum or pressure filtration, centrifugation, membrane-based separation, distillation, carbon-based and zeolite-based adsorption and advanced oxidation treatments Computers are used every day for communications, simulations, budgeting, monitoring controls and word processing hence the computer literacy is very important to improve the efficiency and accuracy of the simulations and assumption that did by chemical engineers. Before chemical engineers design a plant, they have to do some simulation by using some professional programs or software in the computer such as Aspen Technology Programs. Engineering involves working with others and communicating but not only deal with machines so that others able to understand and support the idea provided individually. Consequently, communication skill also must be trained by chemical engineers. When the time chemical engineers present their project or proposal, the others who listening and watching able to fully disgust what are the points and idea about. Management and finance are always the necessary knowledge for everyone in the society including engineers. Many decisions an engineer makes have business consequences. Understanding the business principle can help engineers become more effective. In finance aspect, chemical engineers require to know clearly how to manage a team because engineers can be leaders which work together with others. For the engineers, they are working in a global market requires an understanding of cultural, geographic, economics and environmental factors that influence the decision which made by engineers. International awareness means chemical engineers have to be caution with all the response and effect from the market around us. Lastly the respect for diversity, engineers regularly work in group setting so being able to interact effectively, professionally and respectfully with others will make you a more capable team player. A good engineer team leader must respect all the colleagues so that everyone can work together without any conflict. Conclusion In a conclusion Water treatment is an important processs in our modern life, due to the lack of natural fresh water and increase in population. Many new technology method has been introduce to water treatment industry nowdays. The raw sea water have to go through a certain number of processes strating with either reverse osmosis or thermal distillation to make it usable. Besides this two processes, an electrodialysis process method can also be used. A further water treament process need to be done to make it drinkable, the processes consist of coagulation method, followed by flocculation and sendimentation. A further filtration process is done and finally aeration and disinfection process will take palce before the water is kept in a storage. This processes can be used to make water more acceptable for a desired end-use. These can include use as drinking water, industrial processes, medical and many other uses. The goal of all water treatment process is to remove existing contaminant s in the water, or reduce the concentration of such contaminants so the water becomes fit for its desired end-use. One such use is returning water that has been used back into the natural environment without adverse ecological impact.

Multiple Sclerosis Essay example -- Biology Essays Research Papers

Multiple Sclerosis Multiple sclerosis is a disease of the central nervous system. It most commonly occurs in individuals between the ages of twenty and forty (1) and in higher numbers of women than men (2). In Multiple Sclerosis (or "MS") a loss of the nerves' axon coating myelin prohibits the nerve axons from efficiently conducting action and synaptic potentials. Scar tissue (called plaques or lesions) forms at the points where demyelination occurs in the brain and spinal cord, hence the name "Multiple Sclerosis"or "many scars" (3). The demyelination found in MS is thought to be caused by an autoimmune process, in which the body's immune system attacks its own healthy tissue (4). Other diseases thought to have an autoimmune basis are rheumatoid arthritis, systemic lupus and the insulin dependent form of diabetes mellitus(5). In the immune system, there are two types of white blood cells, B-cells and T-cells. T-cells exist in three forms, all responsible for different immune system responses. Helper T-cells recognize foreign antigens (the substance the immune system aims to destroy), stimulate antibody production, and produce cytokines (chemicals which act as biological messengers) which activate other T-cells. These T-cells are able to recognize antigens through their receptors, made of protein molecules that selectively bind to certain other molecules. Suppressor T-cells perform a function converse to that of their helper counterparts, turning off the immune system response. Cytotoxic T-cells directly attack and destroy antigenic material (6). In MS, an unknown trigger activates helper T-cells whose antigen specific receptors recognize central nervous system myelin as an antigen. While what exactly activates these T-cel... ... MS GENETIC SUSCEPTIBILITY http://www.nmss.org/msinfo/current_research/updates/RMP9620.html 25) VIRUSES http://www.nmss.org/cmsi/cmsi18.html 26) Remyelination Progress Reported http://www.myelin.org/puppress.html 27) EXPERIMENTAL ALLERGIC ENCEPHALOMYELITIS http://www.nmss.org/cmsi/cmsi157.html 28) Current Research Updates http://www.nmss.org/msinfo/current_research/updates/summary.html 29) Virtual Hospital, Chapter 14: Neurology: MS http://www.vh.org/Providers/ClinRef/FPHandbook/Chapter14/08-14.html Other WWW Sites 30) Knowledge Weavers http://medstat.med.utah.edu/kw/ms/ 31) World of Multiple Sclerosis http://www.msif.org/language_choice.html 32) National Multiple Sclerosis Society http://www.nmss.org/ 33) MS Gateway http://www.ms-gateway.com/ 34) MS Gateway Glossary http://www.ms-gateway.com/glossary.html

matrix :: essays research papers

The Matrix Directed by the Wachowski Brothers â€Å"Buckle your seat belt Dorothy, because Kansas is going bye-bye.† -Cypher (Hugo Weaving) â€Å"Through all the action we’re trying to tell a story and there is a lesson to be learned. The movie has a meaning and a positive message. It’s a story for the fight for individuality and compassion and coming to terms with the world. It has such heart and soul.† -Keanu Reeves â€Å"Expect the unexpected.† -The Wachowski Brothers Written and directed by the Wachowski Brothers, released in 1999 Larry Wachowski was born on June 21, 1965 in Chicago, Illinois. His brother Andy Wachowski was born on December 29, 1967 in Chicago Illinois. They started out as comic book writers but then got into the movie business. Their first movie was Bound, which was released in 1996. The also wrote Assassins for Richard Donner. They wrote and directed The Matrix, and it was released in 1999. The Matrix won four Oscars, one Grammy, and an MTV Movie Award. They like to play the audiences perception so that the audience doesn’t know what is going to happen next. Keanu Reeves†¦Neo or Mr. Anderson  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Carrie-Anne Moss†¦Trinity Hugo Weaving†¦Cypher  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Lawrence Fishburne†¦Morphius Sequence This sequence takes place towards the end of the movie. It begins in the lobby of the building where the agents are holding Morphius captive. Neo and Trinity are trying to rescue Morphius. When they walk into the building they must first get through the security guards before they can do anything else. After that they get on the elevator and then stop it. They then get on top of the elevator and shoot the wires after they attach a clamp that will take them to the top of the building. This sequence begins with a ground level pull back dolly shot of Neo entering a building through rotating doors. The camera straight cuts a reverse angle shot of Neo entering the building. The camera pans down to the bag that Neo is placing on to the conveyer belt that takes it through the x-ray machine. The camera straight cuts to the red lights that are flashing on the metal detector that Neo walked through. The camera pans down to Neo with a medium close up shot. There is a straight cut side angle shot of a security guard approaching Neo and asking him to remove any metal objects that he may be carrying. There is then a straight cut close up of Neo opening his trench coat and revealing the weapons that he is carrying.

What is love? Essay -- Literary Analysis, Shakespeare

The word Love may mean many things to different people. For some it can be dangerous and complex, whereas for others it can be simple, yet fulfilling. Many have also attempted to prove the meaning of love, some successful, others not. In the poems A Valediction: Forbidding Mourning by John Donne and Sonnet 147 by William Shakespeare, both authors view love from opposite spectrums. They both attempt to argue what the meaning of love really is. They do this, by using imagery and symbols, and by writing in extended metaphors. In both A Valediction: Forbidding Mourning and Sonnet 147, Donne and Shakespeare’s use of imagery and symbolism are well used to describe the meaning of love according to them. Death is a recurrent image in both poems. In Sonnet 147, Shakespeare compares the love he has for a woman to a disease. Oftentimes disease is associated with death. He uses this imagery, first when he states â€Å"Desire is death† (8); meaning the desire or love he has for this woman, is indeed deadly; a disease which is figuratively leading to his death. Shortly after this, Shakespeare refers to this woman as â€Å"Black as hell, as dark as night† (14) although this may not seem like death right away, one must remember that the colour black and night often signify the idea of death. The line before this states â€Å"I have sworn thee fair, and thought thee bright† (13) Therefore the idea he had of this woman, used to be bright and loving, however he now finds her in a way, evil a nd associates the metaphorical death of his heart to her. Despite using death imagery, Shakespeare also uses medical imagery in the poem. Ultimately disease is associated with medicine. There are a slew of words in the poem which symbolize medical imagery; the words Shak... ...(31-34) In this metaphor, his wife is the fix’d foot which â€Å"in the centre sit†, as she always remains in the same spot, waiting for her husband, the other foot, to return home. Donne writes this, not so much as a love poem, but more as a plea for his wife not to worry about his absence, that their love will only grow stronger, and for her not to be scared that he wont return as (the compass) â€Å"makes me end where I begun.† (38) Despite not being classified a metaphysical poet, Shakespeare like Donne, was very famous for his wordplay and metaphors. Although both authors take different stands on the meaning of love, Donne a positive one and Shakespeare a more negative view; both authors attempt to prove this using imagery and symbols and extended metaphors. The use of metaphors in both Donne and Shakespeare’s poems are intricately intertwined with genius wordplay.

Historical Cost Accounting Essay

Historical cost is a traditional method of recording assets and liabilities at their original or nominal value without making adjustments for inflation. It first came in evidence in Jun 1979 in a French project after numerous debates. The historical cost principle states that the asset should include all cost necessary to get the asset in place and ready for use. The principle of historical cost is based upon two fundamental principles: the principle of monetary standardization and principle of prudence. The principle of monetary standardization ignores the fluctuations in monetary values of asset and liability. The principle of prudence accounts only the losses but ignores potential profit. Assets are evaluated based on acquiring cost, stock is evaluated based on net realizable value or lower cost and debt according to nominal value not present value. Under U.S GAAP ( Generally Accepted Accounting Principles) most assets are recorded at historical cost except for certain financial instruments like trading securities, available for sale securities, derivatives. Under IFRS (International financial Reporting Standards) historical cost is acceptable but not required for property plant and equipment but intangible assets, property, plant and equipment, and investment property may be revalued to fair value. But revaluation will have to be applied to all assets of particular class and they have to make sure this done with regularity so that there is not that large difference between carrying value and market value. Even though in historical cost there is no routine adjustments for inflation but for calculating book value calculations like depreciation, amortization, depletion are done. Historical cost reflects the real value of items at the date of their entering the company. Historical cost is truly more sure, reliable and checkable value. For asset it is the amount paid or to be paid and in case of debt it is the value of equivalents obtained in exchange of obligation or the value to be paid in cash or cash equivalents to settle the debt. Historical cost is more accurate and relevant to make economic decisions since affects the evaluation and selection of decision rule. In order to make decisions and decide which decision rule to choose it needs information which is of same quality of past decisions. Even for making forecast past data is needed as a basis for forecasting which facilitates decision making in an organization. For example- for forecasting price for the next year a company needs past prices as a basis. Moreover it concentrates on what has been earned rather than what could have been earn. Current value accounting anticipates profits that may never be realized. If (for example) the current market prices of property or investments are very di fferent from their historical cost, this information can be disclosed in the notes to the financial statements. There is no need to adjust the amounts in the statement of financial position or the other primary statements. Accounting data under historical cost is subject to less manipulation because the data obtained came from actual transaction rather than from projected or estimated data. The accountants just record it according to the acquired price. As a result it is reported and measured objectively which helps to minimize manipulation of accounting data. The record of past transaction also helps managers to keep accountability and control since they are accountable to the shareholders. For using as a standard, historical cost can be ascertained easily and economically from past accounting records. The major limitation of historical cost is that there is no consideration of changes in price level. Financial statements prepared under historical cost accounting are composed of past data. Changes in monetary value due to change in general price level is not considered. As a result it fails to provide true and fair value in the financial reports. It also leads to unrealistic value of fixed assets, the most striking example is a property or land. It ignores the market value and considers the acquiring cost. Depreciation is a non-cash expense it aims to create a fund to replace the asset when it becomes obsolete. In historical cost accounting the calculation of depreciation is based on historical cost not on the market value so the fund available at the end of the economic life may not be sufficient for the replacement. Thus it creates insufficient provision for depreciation. It also creates unrealistic profit because the revenues are based on current market price whereas the expenses like depreciation is based on historical cost. As a result it overstate profit. Holding gains on inventories are included in profit. During a period of high inflation the monetary value of inventories held may increase significantly while they are being processed. The conventions of historical cost accounting lead to the unrealized part of this holding gain (known as inventory appreciation) being included in profit for the year. Moreover for companies in the service sector or which invest huge amount of capital in technology reflects poorly the true potential. According to prudence concept it accumulate all losses not profit which hide its real potential. Information based on historical cost gives a invalid trend of the company because the result are not adjusted for changes in prices. Only if the value were adjusted the comparison would have been fair. Historical cost no longer reflect economic reality.

Literacy Instruction

Language plays a critical role in literacy instruction. In fact, these two concepts are inseparable. Teaching a learner for the first time requires the use of a common language between the learner and the teacher. By sharing a common language, the two will be able to establish connection and achieve communication, thus lessening the barriers to literacy. Basic reading, for instance, requires modeling by the teacher of how the phonetic sounds of English are produced before the reader is able to decode a word. In addition, teaching reading involves communication between the teacher and the learner. In the pre-reading stage, the teacher needs to give instructions or guidance to reading, and in the post-reading stage, s/he needs to discuss with the reader regarding progress. In such cases, language is indispensable. Also, there are times when the teacher needs to explain what is being read, or determine the context for the reader to understand it better. The role of the language in facilitating learning in early childhood is very essential since â€Å"literacy skills are developed in conjunction with oral language skills.† (Shaughnessy, Sanger, Matteucci, Ritzman, 2004) In relation to this, it is the teacher's role to gauge the learner's oral skills at the beginning of the reading instruction. Knowing the learner's ability for language acquisition would help the teacher â€Å"recognize indications of delays in children's language development.† (Shaughnessy, Sanger, Matteucci, Ritzman, 2004) Likewise, this will also enable the teacher to determine whether interventions are necessary to avoid delays in literacy development. Literacy instruction for adults likewise suggests the importance of language. From giving directions to eliciting critical responses, language serves as a significant tool for acquiring and expressing ideas. Without it, other teaching tools and environment will prove useless. Literacy instruction does not end up in teaching a person how to decode or write words and symbols. The meaning of literacy has continuously evolved and so did literacy instruction. It includes not only basic reading and writing, but higher psychological processes of reading and writing. These two skills involve cognitive levels of thinking which start from the literal to the evaluative level. Reading can be characterized as a higher level of psychological process if it involves cognitive skills of identifying main ideas from minor ones, comprehending the selection, synthesizing central themes or message, analyzing truth in statements, and applying concepts to real-life situations. The last one which presents the evaluative level requires the highest psychological process. In the same way, writing also involves higher psychological process than merely identifying letters or symbols. For instance, writing an essay requires the use of the language to convey ideas in sentences, establishing coherence and unity in a paragraph, and applying past learning in writing activities. To ensure that students’ development does not stop at a certain point, teachers engaged in literacy instruction should guide students to aim for higher cognitive levels in consideration of their readiness. In his research, Morrow (1990) found that students who were provided with teacher guidance proved to display more literacy behaviors than those who were not given guidance. The same is true with adult-guided classrooms. Students tended to have more advanced literacy skills when guided closely. In both reading and writing, we see the role of critical thinking. Critical thinking is another skill involving higher psychological process. Mainly identifying ideas in a reading selection (those that answer questions like what, when, where) is not part of critical thinking. Critical thinking is present when the learners are asked to answer questions starting with â€Å"What if† or â€Å"If you were the character†¦Ã¢â‚¬  Essentially, these questions challenge the minds and response of the learners to their environment, and require the application of practical learning. In both reading and writing, critical thinking can be further enhanced through the method of collaboration in the literacy instruction. In this scenario, the learners’ role is taken to a higher level, from being passive receivers of instructions and information to being active reactors and players. â€Å"Proponents of collaborative learning claim that the active exchange of ideas within small groups not only increases interest among participants but also promotes critical thinking† (Gokhale, 1995). Collaborative learning involves the participation of students and the exchange of ideas among them. Through collaborative learning, the students’ critical thinking is enriched by their peers’ ideas and experiences, resulting in a more productive literacy instruction. Importantly, literacy instruction in the beginners’ level should involve planning by the teacher. In this stage, the teacher serves an active role in providing activities which would challenge the higher psychological processes such as reading, writing, and critical thinking. As such, the teacher should be well-informed of the learners’ background and their capabilities. However, in the pre-adult and adult levels, planning for literacy instruction should likewise involve the students. Students’ suggestions and inclinations should be taken into consideration to assure a more fitting instructional design and to achieve the goal of higher literacy. The rationale behind this is, the students will participate more if they can relate with the situation, and if their needs are addressed well for it is best to start with what they are prepared and interested in. Similarly, the teacher’s guidance in the learning process is valuable to produce the best results. Indeed, in every literacy instruction, working hand in hand with the learners is recommended. References Gokhale, A. (1995). Collaborative learning enhances critical thinking. Journal of Technology Education vol. 7, no.1. Retrieved December 11, 2007, from http://scholar.lib.vt.edu/ejournals/JTE/jte-v7n1/gokhale.jte-v7n1.html Shaughnessy, A., Sanger, D. Matteucci, C., & Ritzman, M. (2004, Feb. 3). Early childhood language and literacy: Survey explores kindergarten teacher's perceptions. The ASHA Leader, pp. 2, 18. Retrieved December 11, 2007, from http://www.asha.org/about/publications/leader-online/archives/2004/040203/040203c.htm ;