The Effects of Water Shortages in the Last Decade Essay Example for Free

The Effects of Water Shortages in the Last Decade Essay The effects of water shortages in the last decade. New water purification technologies This oral presentation will be divided into few parts. The first one will deal with how the water supplies available to the people, have gradually decreased in the last decade; statistical data will be presented, together with some pictures and graphs. Also, it will make a projection of what could be the impact of the water shortages in the near future and will examine how devastating the need for drinking water could become if certain measures for retaining it are taken very soon. The next part will be about some of the innovations in the water purifications technologies. The last part will be a discussion, where your questions you will be welcomed and I will also ask a couple of questions. It is quite popular to refer to our planet Earth as the Blue Planet and probably all of us are aware why this nickname is given. That’s because of earth’s surface is 70% covered by water. Unfortunately, only around 2% of this is drinking water and the question are we using this small quantity responsively is getting more and more discussed recently. The shortest answer to this question is â€Å"No†; humanity needs too much fresh water and shortages have become highly noticeable. It’s needless to say that water is crucial for all life on earth. It plays an essential role for our health, economy, food production, and environment. Also, drinking fresh water is a compulsory element of the development of the public health, since 21 of the 37 primary diseases are related to water and sanitation. With the growing world population (over 7 billion so far), water consumption rate doubles every 20 years, a pace that is double the rate of population growth. If population and consumption trends persist, it is estimated that the demand for water will surpass its availability by 56%, and 1. 8 billion people will be living in regions of water scarcity by 2025. This situation is exacerbated by the fact that developing countries, already experiencing water-stress, often have the highest population growth rates—bringing more people into a region that already cannot support them. Here it’s important to explain the terms â€Å"water-stressed countries† and â€Å"water-scarce regions†, given the fact that in the near future they will become part of the geographical description of further more parts of the world. Water-stressed countries are regions with fewer than 1,700 m3 of water per capita per year. People living in water-stressed regions must make painful decisions about using water for personal consumption, agriculture, or industry. Regions with fewer than 1,000 m3 per person per year are defined as water-scarce. Water-scarcity hinders economic development, strains the environment, and drastically limits food availability. The 2009 World Water Development report revealed that nearly half of the global population will be living in regions of high water stress by 2030.

Renewable And Non Renewable Resources

Renewable And Non Renewable Resources Our societys emphasis on green living and the global focus on conservation provide the perfect backdrop for teaching students about fossil fuels. Children are naturally curious about whats going on in the world around them. Now is the perfect time for us, as educators, to capitalize on our students innate curiosity by leveraging current events in the world such as the rapidly increasing prices of gasoline for motor vehicles and the ongoing search for economical and efficient forms of renewable energy to engage students in study about how fossil fuels, natural resources and Provide appropriate vocabulary words. Give students the basic vocabulary words they will need in order to achieve your lesson objectives. Basic vocabulary words for teaching students about fossil fuels would include: fossil fuels, coal, oil, natural gas, renewable and nonrenewable. This module will help the students to learn about the fossils fuel , its importance ,need of its conservation and its harmful effects The teacher may use various skills to decide the complexity level of the content. However teacher may take up the topic as given below- (a)Complexity of content(concrete, Symbolic,Abstract) CONCRETE SYMBOLIC ABSTRACT Natural resources,Destructive distillation of coal, Combustion of fossils fuel Exhaustible and non exhaustible energy resources , Formation of fossils fuel, Harmful effects of caused by fossils fuels Fractional distillation (b) Learning Environment- 1. The chapter may be introduced in class rooms, school lab (bringing sample of different items to the lab) , computer lab (by a power point presentation),Outdoor trip etc. 2.Sequence of the lesson can be taken this way_ Introduction Using concrete or symbolic material for group discussion or the class can be divided into groups or individually students may be engaged in a warm up activity as given in students module. Students wi;ll be asked to make a table and fill that PLASTIC PAPER GLASS METAL WOOD OTHER The possible answers to the questions asked in students module will be- Which column had the longest list? (Answer: It will very likely be plastic.) Which category do you think you depend on most? Why? (Answers will vary.) Where do you think these items come from? (Answer: Everything at some point comes from our natural resources. Paper and wood come from trees, plastics are made from oil, glass is made from sand, and metal is made from ore, etc.) You may also do this as a whole class, instead of individually. You may draw a puzzle with blanks and may ask the students to fill in the blanks to complete the schemetic diagram related to natural resources as shown in students module or show the diagram and ask them to list natural resources 1.2 RENEWABLE AND NON RENEWABLE RESOURCE Teacher may begin the lesson with a small activity of hunting fossil fuel STUDENT ACTIVITY 1 or any other activity or can narrate a story to introduce two categories of natural resources Teacher may involve the students in activities highlighting the depelition of resources as in students module Students Activity 2 DEPLETION OF RESOURCES SIMULATION Through the activity, students will hypothesize that as the next generation comes along, there will be fewer resources available to them and eventually, there could be nothing at all. In addition the number of people using a resource and the amount each person uses are critical in determining the rate at which resources, both renewable and nonrenewable, get used up. Teacher may have a supply of extra popcorn (out of sight of the class) for those students who do not participate directly in the simulation Students will probably eat as much of the popcorn as they can without any thought as to who will come after them. By the time the 3rd generation students are finished, there should be little or no popcorn left. Some of the generation coming next people will therefore have little or none at all. Do not discuss what is happening to the popcorn until all the generations have gotten their popcorn. Some students will begin to realize what is happening. Some students in the 2nd generation may think of the 3rd generation and not take as much. The teacher should just watch and listen without making any comments. Review the definitions of renewable resource, and nonrenewable resource. Relate these definitions to the popcorn simulation. Did any of the students who were part of this simulation think about those who might be eating after them, or were they only trying to get as much popcorn as they could? Assessment, Student Product Each student will turn in their own report after they have gone over the discussion points. Each group of 4 will create a slogan that advocates personal responsibility for resource conservation Teacher may build up the lesson by asking the students to perform another activity in groups comparing renewable and non renewable resources as in students module or may use internet for the students research to compare different energy sources for which the class may be divided into groups and assign different energy resources to be researched and compared to coal energy. Students should include topics of safety, efficiency,environmental impacts and cost. Teacher may involve the students in STUDENTS ACTIVITY 3 to understand symbolically that Coal, oil, natural gas and nuclear fuels will last some day and so they are non renewable resource while renewable source will never finish Assessment: Have students explain the exercise and their findings to the class. Encourage them to discuss what other factors might dictate which energy sources are used by a community, such as environmental impact and the persuasion of special interest groups. What specific factors influence the choices of energy sources in your area? How have local energy costs changed over the past ten years? Use a debate format to discuss factors that might dictate community decisions as stated above. Extension: Encourage students to find out what energy sources are used in other countries. Direct them toward coal-dependent countries (such as the United Kingdom and Germany), as well as countries that do not rely primarily upon coal for their energy (such as Sweden, France, and Japan). Challenge them to find out and compare the energy costs of other countries to that of the United States. Continue with researching 10 years of costs/supply and demand and graph the changes over the 10-year period. Have students compare and contrast the outcomes between the different energy sources. Teacher may share the following facts with students to arouse their interest such as- It took 10 feet of plant matter to make 1 foot of coal. The first oil well in the world was drilled in Pennsylvania, USA. World coal consumption is more than 5.3 billion tons annually of which three quarters are used for generating electricity. The earliest known use of coal was in China. Coal from the Fu-shun mine in northeastern China may have been used to smelt copper as early as 3,000 years ago. The Chinese thought coal was a stone that could burn To run a 100-watt light bulb 24 hours a day for a year we need to use about 714 pounds (325 kg) of coal in coal powered power plant (thermal efficiency of such power plant is typically abut 40%). One liter of regular gasoline is the time-rendered result of about 23.5 tonnes of ancient organic material deposited on the ocean floor. . On August 27, 1859, Edwin L. Drake (the man standing on the right in the black and white picture to the right), struck liquid oil at his well near Titusville, Pennsylvania. He found oil under ground and a way that could pump it to the surface. The well pumped the oil into barrels made out of wood. This method of drilling for oil is still being used today all over the world in areas where oil can be found below the surface. 1.3 COAL Coal is a hard, black colored rock-like substance. It is made up of carbon, hydrogen, oxygen, nitrogen and varying amounts of sulphur. There are three main types of coal anthracite, bituminous and lignite. Anthracite coal is the hardest and has more carbon, which gives it a higher energy content. Lignite is the softest and is low in carbon but high in hydrogen and oxygen content. Bituminous is in between. Today, the precursor to coal-peat-is still found in many countries and is also used as an energy source. Teacher may introduce the concept by giving the students the basic knowledge about coal which they are already familiar of or may ask some general questions about the coal 1.3.1 COAL FORMATION The teacher may plot a story of historical background of coal or give the idea by demonstrating an activity as described in student module-COAL FORMATION ACTIVITY The teacher must arrange the material beforehand. The activity will help in reinforcing Critical thinking ,Cooperative learning The activity may take two class periods over four weeks I f you line your container with plastic wrap before you begin, you can lift the whole formation out when it is dry. T his is a smelly activity. If you have an area where you can put this out of the way and observe it occasionally, you will like it better! Teacher can further illustrate the mining of coal through the activity discussed in students modulestudents activity 4 Chocolate Chip Cookie Mining This activity teaches students about coal and mining. Discuss with the students how coal is excavated . Coal is mined out of the ground using various methods. Some coal mines are dug by sinking vertical or horizontal shafts deep underground, and coal miners travel by elevators or trains deep under ground to dig the coal. Other coal is mined in strip mines where huge steam shovels strip away the top layers above the coal. The layers are then restored after the coal is taken away. The coal is then shipped by train and boats and even in pipelines. In pipelines, the coal is ground up and mixed with water to make whats called a slurry. This is then pumped many miles through pipelines. At the other end, the coal is used to fuel power plants and other factories. 1.3.2 TYPES OF COAL: Types of coal may be introduced to the students by showing them samples of different types of coal and comparing their physical properties through STUDENTS ACTIVITY 5- coal identification activity. This will help students to understand the characteristics of different types of coal and enhance their Critical thinking,Cooperative learning and skill of Comparison and contrast. They will lso understand that the harder coal absorbs more heat. Teacher may discuss with students . Does burning show that peat is the lowest rank of coal? Does the manner of burning of bituminous coal show that it still has volatile material (gas) in it? 1.3.3 COMBUSTION OF COAL Combustion or burning is the sequence of exothermic chemical reactions between a fuel and an oxidant accompanied by the production of heat and conversion of chemical species. The release of heat can result in the production of light in the form of either glowing or a flame. To understand that coal is combustible teacher may perform an activity as stated in students moduleSTUDENTS ACTIVITY- 6 Teacher must arrange for the material before hand . If lignite coal sample is not available, charcoal may be used Students should be motivated to illustrate and describe their observations. Teacher may discuss how coal may be useful because it is combustible and gives off heat. Teacher may take a small sample of the dried plant matter from and hold with forceps. Place sample in the flame of a candle and observe combustion. (This matter can be compared to peat.) Discuss observations. . 1.3.4 DESTRUCTIVE DISTILLATION OF COAL Destructive distillation is the chemical process involving the decomposition of feedstock by heating to a high temperature; the term generally applies to processing of organic material in the absence of air or in the presence of limited amounts of oxygen or other reagents, catalysts, or solvents, such as steam or phenols. The process breaks up or cracks large molecules. Products like coke, coal gas, gas carbon, coal tar and ammonia liquor are formed after the destructive distillation of coal. This helps in producing thousands of distinct chemical compounds. Teacher may demonstrate the pocess of destructive distillation of coal in lab or class as illustrated in students module,and keep the students interest entact . Teacher will discuss different observations about the mixtures collected in the end in test tube and beaker and also explain their uses eith the help of placards or flashcards. 1.4PETOLEUM . Petroleum or crude oil, and natural gas are important hydrocarbons that are found in nature within pores and fractures of rocks. Oil and gas form over millions of years as the result of the decay of marine organisms. These organisms die and collect on the ocean floor. Sediments such as clay and mud are deposited above these organisms. During burial and compaction, the organic matter becomes heated. Hydrocarbons are formed and are forced out of the source rock into permeable beds such as sandstone. As by now the students are familiar with the concept of fossils fuel with its examples and its formation in case of coal the teacher may build the lesson on the previous knowledge of the students with the help of role play Teacher may give students more information about the excretion of petroleum Because oil and gas are not very dense, they migrate upward through the water-saturated rock layers. In some cases, this movement is stopped by overlying impermeable layers of rock such as shale or rock salt and the hydrocarbons are trapped. Then, the oil and natural gas form a reservoir in the porous rock. This type of hydrocarbon accumulation requires a source rock, a reservoir rock, and a cap rock. Most of the worlds reservoirs are in sandstone, limestone, and dolomites. Structural traps are related to folds, faults, or salt domes. When an anticline fold that contains hydrocarbons is drilled, the first material encountered is usually natural gas. This gas often is underlain by oil due to density differences. Water is the densest fluid and is found at the bottom of a reservoir. Secondary recovery methods can be used to increase the amount of crude oil that can be pumped from wells. Presently only about 30 percent of the crude oil in a well can be recovered. However, as oil reserves dwindle, steam, carbon dioxide, and detergents can be used to force out the heavy oil that normally cannot be pumped. 1.4.1 REFINING OF PETROLEUM Petroleum in its crude state consists of various organic compounds that must be refined to form usable products. After giving a brief idea about refining of petroleum and fractional distillation the divide the students into research teams. Each team will research how fractional distillation works, as well as describe one of the major products of fractional distillation. Students may then be motivated to use distillation to separate 2 liquids . The teacher must approve the distillation set-up of the students Misconceptions: Students will assume that the mixture will keep getting hotter and hotter as the water boils. They will not expect the temperature to stay steady until almost all the water has been converted to steam. Students may also think that the melted ice cube is dripping through the foil into the beaker. Teacher needs to clarify their misconception Students should be encouraged to use diagrams and charts to present their information. A rubric is provided for assessing the group work at this stage. A copy of this rubric should be given to students before they start their research so that they are aware of the grading criteria. The objectives of the activity performed are . Students will learn that fractional distillation is the first stage in processing crude oil into usable products. (The other two stages are: Conversion: cracking and rearranging of molecules, and Treatment.) Students will understand how fractional distillation works and what products are produced. They will become aware of how these products are used in their world. Students will familiarize themselves with 8 major products of fractional distillation. Students will be able to perform a simple distillation of liquids modeling the distillation of crude oil. Students will share, display, and explain specific information gathered in their research. Research time will vary based on the availability of computers. Most of the research can be completed in 1 to 2 class periods on the computer. The actual distillation will take one period The activity will help improving the following skills of the students Cooperative learning Student centered learning Communication of information Relevant application to daily life Following Directions Making Connections Mathematics integration Drawing Conclusions Because so many petroleum-based products are found in the home,so teacher may motivate the students to perform a take home activity. To complete the activity, students work with their families to identify six petroleum-based products at home. They write those products on the list. Then they think of one way to help conserve petroleum, by reducing their use of a petroleum product, reusing a petroleum product many times over, or recycling a product so it can be made into something else. They add their conservation idea to the bottom of the list, and have their at-home helper sign the form. When students have completed this short at-home activity, they will bring their list back to school and share it with their classmate. If students are having difficulty completing the project at home, a few minutes could be devoted to the activity in school. 1.4.2 COMBUSTION OF PETROL Teacher may correlate the topic with combustion of petrol in vehicles and explain that incomplete combustion of petrol is dreadful as it produces CO which is suffocating. Students may be motivated to collect data in this regard and analyze and help them to differentiate between the combustion of coal and petrol. 1.5 HARMFUL EFFECTS OF EXCCESSIVE COMBUSTION OF COAL AND PETROLEUM Many non renewable energy resources have detrimental consequences upon the environment. Most people are aware of the greenhouse effect created by carbon dioxide and other greenhouse gases that are released by gasoline-powered vehicles, but this is only one of many serious consequences. Coal plants alone generate hundreds of millions of tons of harmful byproducts, including flue gas, desulfurization sludge, fly ash, and bottom ash. These materials can poison waterways and leach harmful toxins such as arsenic, mercury, uranium, and thorium into the ground and water.. Combustion of these fossil fuels is considered to be the largest contributing factor to the release of greenhouse gases into the atmosphere. Teacher may use powerpoint presentations or vedieosto illustrate the concept 1.6 IMPORTANCE OF NONRNEWABLE SOURCES Fossil fuels are of great importance because they can be burned (oxidized to carbon dioxide and water), producing significant amounts of energy per unit weight. The use of coal as a fuel predates recorded history. Coal was used to run furnaces for the melting of metal ore. . Teacher may introduce the topic with some questions such as What function crude oil serves in our life. Is it something that is really necessary in life? What if it was not available, how would our lives differ? (Students answers will vary). Emind students that Petroleum is the Source of many objects ,e.g. à ¢Ã¢â€š ¬Ã‚ ¢ bandage à ¢Ã¢â€š ¬Ã‚ ¢ glue à ¢Ã¢â€š ¬Ã‚ ¢ plastic bagà ¢Ã¢â€š ¬Ã‚ ¢ bubble gum à ¢Ã¢â€š ¬Ã‚ ¢ golf ball à ¢Ã¢â€š ¬Ã‚ ¢ plastic container or bottleà ¢Ã¢â€š ¬Ã‚ ¢ comb à ¢Ã¢â€š ¬Ã‚ ¢ lipstick à ¢Ã¢â€š ¬Ã‚ ¢ toothbrush and toothpasteà ¢Ã¢â€š ¬Ã‚ ¢ crayon à ¢Ã¢â€š ¬Ã‚ ¢ nail polish à ¢Ã¢â€š ¬Ã‚ ¢ tube of hand creamà ¢Ã¢â€š ¬Ã‚ ¢ elastic band à ¢Ã¢â€š ¬Ã‚ ¢ panty hose à ¢Ã¢â€š ¬Ã‚ ¢ wax paper T ell students that one of the most common petroleum products is gasoline that goes into a car to make it run. Remind students that petroleum-based products can last a very long time. Thats why we should reuse and recycle them whenever we can. For a greater challenge, students could be motivated to write their own Who Am I? questions for different petroleum-based products. When there are enough clues written, each student could read out a clue and ask the rest of the class to guess the product. In the end teacher may guide the students to conserve the fossils fuel -coal and petoleum

An Overview of Butadiene

An Overview of Butadiene 1,3 Butadiene 1,3-Butadiene with its molecular structure of [emailprotected]=CH2 have widely synonym as butadiene,,-butadiene, divinyl, buta-1,3-diene, vinylethylene, vinylethylene, bivinyl, erythrene, biethylene, and pyrrolylene refer to the same physical and chemical properties. It has same Chemical Abstracts Service (CAS) registry number which is 106-99-0, and its Registry of Toxic Effects of Chemical Substances (RTECS) number is EI9275000. As compared to the air, the conversation factor of to 1ppm butadiene is equal to 2.21 mg/m3 in the air. Further important identity and physicochemical properties of butadiene is described as per Table 1. Â   Generally, butadiene was produce during combustion resulting from combustion of organic matters whether it come from natural process or human activities. Among of natural process and human activities, the main contributor of butadiene presence in earth majorly come from human activity which cause high impact to surrounding life and environment. As part of human activities, 1,3 Butadiene being used primarily and commercially in the making of synthetic rubbers and polymers. 1,3 butadiene was produced by complex and specific process as co-product of ethylene during cracking at high temperature (produced C4) at the steam crackers units. The crude C4 that produced from steam cracker units or process then fed to the butadiene extraction units for separation process of butadiene, isobutenes and the other C4s (byproduct called as Raffinate 1) through extractive distillation. The most advanced Butadiene extraction technology is come from BASF NMP Process in which 1,3 Butadiene is extract as per Diagram 1 by utilized N-methyl-2-pyrrolidone (NMP) as solvent. Characteristic 1,3-Butadiene is colourless gas at room temperature with gasoline or mild aromatic odor, highly flammable when exposed to heat and insoluble in water but soluble in ether, acetone, benzene and ethanol. It is very reactive: it may form acrolein and peroxides upon exposure to air, it can react with oxidizing materials, and it polymerizes readily, particularly if oxygen is present. Butadiene is stabilized with hydroquinone, catechol, t-butyl catechol or aliphatic mercaptans1,2. In addition from that, as per GHS-US classification, 1,3 Butadiene is classified and hazard label as per Table 2 and Diagram 2 below: CLASS Hazard Statement Description H220 Flammable Gas Category 1 Exteremly flammable gas H280 Refrigerated Liquefied Gas Contains gas under pressure; may explode if heated H315 Skin Irritation Category 2 Causes skin irritation H319 Eye Irrititation Category 2A Causes serious eye irritation H340 Germ Cell Mutagen Category 1B May cause genetic defects H350 Carcinogen Category 1A May cause cancer Table 2: Classification of 1,3 Butadiene as per GHS-US Classficiation Diagram 2: Hazard label/pictogramns of 1,3 Butadiene as per GHS-US Classficiation Used 1,3 Butadiene is the main raw material to manufacture variety type of rubbers and plastics. It is being used as an intermediate ingredient; monomers in production of polymers, synthetic rubbers or elastomers, and other chemicals. As substitution for natural rubber, Butadiene being used widely in producing synthetic rubbers and polymer which offers numerous advantages in term of improvement in performance, safety and functionality, and lower costs. Over 75% of 1,3 Butadiende was used to produce Synthetic rubber. Synthetic rubber derived from 1,3 butadiene include Styrene-butadiene rubber (SBR), poly-butadiene rubber (PBR), nitrile rubber (NR) and poly-chloroprene(Neoprene). These synthetic rubbers then undergo several others specific process to produce product like: Styrene-butadiene rubber (SBR) and poly-butadiene rubber (PBR) are used in the making of tyres and plastic where able to enhance and increase the resistance of vehicles tyre and plastic towards heat degradation, blowouts, wear and tear. Neoprene or poly-chloroprene is used extensively in manufacture of latex goods which is non-tire application such as gloves, foams, waders and wearsuits. Nitrile Rubber(NR) have variety of end product which mainly used to produce rubber hoses, gasket and seals for automobiles . Remaining 25% of 1,3 Butadiene was used to produce polymers. Polymerd derived from 1,3 include Acrylonitrile-butadiene-styrene (ABS) resins, poly-butadiene polymers, nitrile barrier resins and thermoplastic resins. Among the others, ABS resin was widely used in large volume of thermoplastic resin, containing about 20%- 30% of 1,3 butadiene by weight to produce automobiles part and appliances in automotive industry . Apart from that, 1,3- Butadiene also is used in the production of adhesives for packaging, transporting, or holding food; in components of paper and paperboard that are in contact with dry food; and as a modifier in the production of semirigid and rigid vinyl chloride plastic food-contact articles. Human Exposure The general human exposure can be separated onto two: occupational exposure and non-occupational exposure and describe as per below: 1.3.1 Occupational exposure The highest exposure of butadiene is mainly occurs in occupational settings or workplace area and its surroundings. Potential areas include several industries like: petroleum refinery and operation plant (where the crude C4 cracking process take over and involves butadiene extraction, gasoline production and distribution), distillation and production of butadiene monomer plant, factory or manufacturer of various butadiene based product like synthetic rubber and polymers plant such as tires, gloves and variety injection moulding industries (IARC, 1999). Based from data collected from European Chemical Bereau during 1984 to 1987, the arithmetic means of butadiene concentration at petrochemical and petroleum refinery plant industries area in several location of European countries is ranged from 0.1 to 6.4 mg/m3 Other than that, by refer from survey conducted by occupational hygiene of United Kingdom shows that the mean concentration of butadiene generally below 11mg/m3 with most below 2.2 mg/m3 for butadient production areas while in polymer manufacturer area time-weighted averaged around (4.4 to 6.6mg/m3). Meanwhile at USA in 1985, the arithmetic mean concentration is ranged from 1 to 277 mg/m3 for monomer production plant and 0.04 to 32mg/m3 for polymer production plant. (IARC, 1999; European Chemicals Bureau, 2001). 1.3.2 Non-occupational exposure For non-occupational exposure area, it is obtained that the butadiene mean concentration in ambient air is much lower in ÃŽÂ ¼g/m3 measured than reported in occupational exposure area which measured in mg/m3. Elevation of concentration observed occurs at the vicinity of source like municipal structural fires area, smoking shed or cigarette smoke area, brush and wood fires Butadiene has been widely detected in ambient air but at much lower levels (ÃŽÂ ¼g/m3) than reported in some occupational settings (mg/m3). Elevated concentrations may occur in the vicinity of point sources, such as municipal structural fires, wood and brush fires; cigarette smoking; volatilization gasoline area as well as combustion through vehicle emissions (IARC, 2008). Based on data and study conducted during 1990 and 1994, involvement of 14 cities, rural or towns at Ontario, Canada shows that the results from 1611 samples of outdoor air collected for mean concentration of butadiene is ranged around 0.1ÃŽÂ ¼g/m3 with maximum of 1.7 ÃŽÂ ¼g/m3. (Health Canada, 2000). Dollard et al. (2007) measured butadiene concentrations at rural, urban background (UB), urban industry influenced (UI) and busy-roadtraffic (BR) locations in the United Kingdom from 1993 to 2004. Mean rural levels dropped from 0.39 to 0.02 ÃŽÂ ¼g/m3 between 1995 and 2004; mean UB levels decreased from 0.64 to 0.15 ÃŽÂ ¼g/m3 in 1993-2004; mean UI levels came down from 0.85 to 0.35 ÃŽÂ ¼g/m3 in 1995-2000; and mean BR levels went from 3.3 to 0.57 ÃŽÂ ¼g/m3 in the period 1997-2004. . Human effect Exposure of 1,3 Butadiene can effect human health and the severity can be separated into two, which is acute and chronic. For acute exposure, it can be further split into high doses and low doses. Acute low doses exposure will caused irritation to nose, eyes, lungs and throat. These frostbite injury also may lead to occur through exposure to skin. Acute high doses of exposures will lead to cause damage of central nervous system by showing symptoms to human body such vertigo, general tiredness, distorted blurred vision headache, nausea fainting and decrease pulse rate. Human epidemiological studies has been conducted to identify the Chronic effects to human that cause by exposure to 1,3-butadiene, the result shown the effect to human can cause cancer and cardiovascular diseases. However, due to some limitation and cofounding factors in study of cancer to human due to exposure by 1,3-Butadiene such as simultaneous exposure to syrene and benzene, smoking; the exact causal factors unable to established well. Extensive lab experiment involving animal such as mice and rat has been performed and study to observe relationship of chronic exposure of 1,3-butadiene to cancer. The studies through mice and rat has shown the developmental problems and reproductive effected the animals. Through this study, 1,3-Butadiene has been classified as human carcinogen from EPA and rated as A2; suspected human carcinogen as per The American Conference of Governmental Industrial Hygienists (ACGIH). Further human effect exposed to 1,3-butadiene explain on Table 2. Carcinogenicity to human Based on epidemiological studies conducted shows that high tendancy or risk of leukemia or others cancer to attacked on the lymphohaematopoietic system when chronic exposure to 1,3-Butadiene. This involve three studies on employed workers at 1,3-Butadiene production facility of styrene-butadiene-rubber(SBR) plant where the major exposure is 1,3-butadiene monomer alone. The result of the studies shows the same relation or overlapping cohort population. It was observed in two studies at butadiene monomer facility, overall have slightly excess of mortality from leukaemia while in third study shows decrease in mortality of leukaemia. The increased mortality from leukaemia in one of the monomer industry cohorts was more pronounced among workers who had been exposed at high levels during the first years of production (Second World War). In this cohort, no increase in leukaemia was observed with duration of exposure or cumulative exposure. Based on the study on SBR workers by University of Alabama at Birmingham (USA) considered as very informative data where the study involves in examine the mortality rates of about 17,000 workers through eight facility in Canada and USA. A limiting factor in the evaluations was that the diagnosis and classification of lymphatic and haematopoietic malignancies are very complex and have undergone several changes over the course of time. Although overall mortality from leukemia was only slightly higher in the update of the most recent cohort, a larger increase of deaths from leukemia seen in workers in the most highly exposed from plants and one employee per hour paid, especially those who was hired in early years and has ten years or more jobs. Furthermore, a significant correlation between cumulative exposure of 1,3-butadiene and leukemia deaths observed in this study. A recent analysis shows that the exposure-response relationship for 1,3-butadiene and leukemia are free from exposure to styrene and dimethyldithiocarbamate. Studies with mice showed increased tumour formation in various organs in both sexes at 1,3-butadiene exposures to approximately 14 mg/m3 (females) and 44 mg/m3 (males). This was not observed in rats at exposures up to 2,200 mg/m3, likely due to the crucial role of oxidative metabolism: 1,3-butadiene requires metabolic activation to generate electrophilic epoxides in which important species differences exist (mice are more efficient in the production of epoxide metabolites of butadiene, while rats and humans are more efficient in the hydrolytic detoxification of these metabolites). Many tests on mutagenicity, genotoxicity and mechanism of action clearly indicate that 1,3-butadiene is a genotoxic compound in humans and in experimental animals, requiring metabolic activation to generate electrophilic and DNA-reactive epoxides (epoxybutene, epoxybutanediol and diepoxybutane), one or more of which are considered to be the ultimate carcinogens. Health Effect Description Symptoms Inhalation problem or respiratory irritation Inhalation of 1,3 butadiene gases or aerosols such as mists or fumes generated by the material during handling and normal works can be damaging the human health. Excessive exposures can cause severe irritation to upper respiratory system or central nervous system like nose and throat. 1, 3 butadiene can cause narcotic effects or anesthetic including dizziness and drowsiness, alertness, sleepiness, lack of coordination, vertigo, loss of reflexes and death. Ingestion Drink or food that contaminate with 1,3-Butadiene which the residues of 1,3-butadiene have been found in drink and food container. (McNeal and Breder 1987) Liquid butadiene can cause frostbite to the lips but this unlikely to happen because very low amount of butadiene used in food and drink containers. Eye Person or human can be exposed to the 1,3 Butadiene liquid and gases during manufacture or at occupational area Transient discomfort characterised by tearing or conjunctival redness, pain and blurred vision.exposed to liquid butadiene can cause frostbite if it contacts the eyes and rapidly evaporates. Skin Contact Not to have any skin irritation or harmful to human health in normal condition. It will affected if the person involve in injury or wound In touch with liquid butadiene may cause frostbite and rapidly evaporate. When entry into the blood-stream, through cuts, abrasions or lesions, may produce systemic injury with harmful effects. Chronic As per International Agency for Research on Cancer (IARC), Butadiene is listed as human carcinogen which can directly cause cancer in human. Based on experiments, there is an evident that butadiene can cause genetic defect and may result in toxic effecs to the unborn baby. Cancer ex: leukemia, damaged of cardiovascular system, genetic defect Table 2: Health effect of 1,3 Butadiene to human health Reduce the risk of hazardous In order to reduce risk of hazardous of 1,3butadiene, many precaution and controls shall take in consideration. Separated into two; occupational and non-occupational exposure. 4.1 Occupational The higher human exposure to 1,3 Butadiene is come from occupational environment. Appropriate control can be taking in consideration to reduce the risk exposure by include appropriate engineering controls, hand protection, eye protection, skin and body protection, respiratory protection and environmental exposure control. 4.1.1 A Appropriate engineering controls Appropriate engineering controls : This product must be confined with vapor-tight equipment. With this confinement, vapors should not be released, and local exhaust should be satisfactory. An explosion-proof system is acceptable. Ensure that any venting of material is in compliance with international, federal/national, state/provincial, and local regulations. Hand protection : Wear protective gloves made of PVC. Eye protection : Wear safety glasses with side shields. Wear safety glasses with side shields or goggles when transfilling or breaking transfer connections. Provide readily accessible eye wash stations and safety showers. Skin and body protection : Wear work gloves and metatarsal shoes for cylinder handling. Protective equipment where needed. Select in accordance with OSHA 29 CFR 1910.132, 1910.136, and 1910.138. Respiratory protection : When workplace conditions warrant respirator use, follow a respiratory protection program that meets OSHA 29 CFR 1910.134, ANSI Z88.2, or MSHA 30 CFR 72.710 (where applicable). Use an air-supplied or air-purifying cartridge if the action level is exceeded. Ensure that the respirator has the appropriate protection factor for the exposure level. If cartridge type respirators are used, the cartridge must be appropriate for the chemical exposure. For emergencies or instances with unknown exposure levels, use a self-contained breathing apparatus (SCBA). Environmental exposure controls : Refer to local regulations for restriction of emissions to the atmosphere. See section 13 for specific methods for waste gas treatment. Refer to local regulations for restriction of emissions to the atmosphere. Other information : Consider the use of flame resistant anti-static safety clothing. Wear safety shoes while handling containers. Keep suitable chemically resistant protective clothing readily available for emergency use. Wear leather safety gloves and safety shoes when handling cylinders. Non-occupational Wood burning Take precautions to minimize the amount of smoke released into the home during wood burning. Vehicle engines Make sure vehicle engines are turned off when in an enclosed space such as a garage. Vehicle traffic Minimize time spent near areas of heavy vehicle traffic and avoid living very close to busy roads. Tobacco smoke Families can reduce exposure to 1,3-butadiene by avoiding tobacco smoke, particularly indoors.

Indonesia Essay -- essays research papers fc

  Ã‚  Ã‚  Ã‚  Ã‚  After Indonesia declared independence in 1945 the country’s leader, Sukarno, faced the extremely difficult task of creating a unified state out of Indonesia’s numerous ethnic groups. Also ever since its independence Indonesia’s rulers had to suppress uprisings of muslim groups because it threatened the country’s secular ideology.   Ã‚  Ã‚  Ã‚  Ã‚  The attempts by Indonesia’s leaders to maintain unity and the ways in which the military suppressed separatist movements fueled many of the economic, social, and political problems the nation is facing today. After the tsunami, many of the issues surrounding the nationalist issue resurfaced and might change the nature of the conflict between supporters of Indonesian unity and those seeking independence.   Ã‚  Ã‚  Ã‚  Ã‚  The rebels in Aceh claim that the region was illegally annexed by Indonesia at the time of independence, and a separatist movement has been active there since 1976. During the regime of Suharto the military was given absolute power, and the continuous military presence in the region was marked by brutality towards the Acehnese and mistreatment of suspected rebels. Therefore many Acehnese feel a deep sense of distrust towards Indonesia. Since 2003 Aceh has been under Indonesian military rule and the area was closed off to foreigners as an attempt to isolate the area and crush the separatist movement. Indonesia allowed virtually no foreign presence in Aceh. Many believe that the isolation of the area was an attempt by the government t...

Dickens Social Commentary in Great Expectations Essay -- GCSE English

Dickens' Social Commentary in Great Expectations  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚        Ã‚   Charles Dickens' Great Expectations stands as one of the most highly revered works in all of English literature. The novel's perennial appeal lies in its penetrating depictions of character, rich panoramas of social milieu, and implicit crusades against social evils.1 Dickens used the growth of his characters in Great Expectations, particularly Pip, in relation to others to write about social reform, and most effectively illustrated this by using the first-person narrative style. In Great Expectations, Charles Dickens has written a social commentary using the development of his characters to illustrate his message. In my paper, I will concentrate on three of the main characters, Magwitch, Miss Havisham, Estella, and Joe Gargery. During the time when he lived, Dickens recognized many evils in society. In Great Expectations he focused on the problem of the whole idea of a class in society. It was a social commentary on society. His way to illustrate the solution to the problem of class in society was "to create characters who can get beyond the limitations and divisions of class identifications and see themselves as responsible humans."2 The people who read Dickens' works were often the kinds of people he was attacking. Dickens lived during the Victorian age which was known as the age of social criticism. Great Expectations was Dickens first attack on class in society.3 Dickens did not come right out and preach about social reform in his novels. He uses his rich characters to illustrate the values and morals he is trying to get across. Great Expectations is a novel of social criticism. In Dickens' opinion the two main social evils were selfishness an... ...ornback, 22. 3. Hornback, 4-5. 4. Hornback, 27-28. 5. Charles Dickens, Great Expectations (New York: Dodd, Mead and Company, 1942), 3. 6. Dickens, 395. 7. Dickens, 68. 8. Dickens, 71 . 9. Dickens, 72. 10. Dickens, 72. 11. Dickens, 598. 12. Dickens, 57. 13. Hornback, 25-26. 14. Hornback, 60.          Works Cited Chesterton, G.K. Charles Dickens: A Critical Study. New York: Dodd, Mead and Company, 1906. Dickens, Charles. Great Expectations. New York: Dodd, Mead and Company, 1942. Hornback, Bert G. Great Expectations: A Novel of Friendship. Boston: Twayne Publishers, 1987. Pearson, Hesketh. Dickens, His Character, Comedy, and Career. New York: Harper and Brothers Publishers, 1949. Priestley, J.B. Charles Dickens and His World. New York: Charles Scribner's Sons, 1961.   

The Usage Of A Bandgap Reference Voltage Engineering Essay

A bandgap mention electromotive force is an indispensable constituent of an parallel to digital converter.It is frequently used to provide a mention electromotive force which is compared with others voltages.The bandgap mention used in diverse applications is based on the thought of Hilbiler in 1964 [ 1 ] aˆ‚A bandgap mention electromotive force with low sensitiveness to temperature and supply electromotive force is normally required in parallel or digital circuits. Low electromotive force and low power are two of import design standards in both parallel and digital systems.It been expected that the whole electronics system will be operated down to a individual 1-V supply in near future.The bandgap mention ( BGR ) generators which can be operated under 1-V supply have been widely used in DRAM, falsh memories, analog-digital convertor ( ADC ) and assorted parallel devices.So far many techniques have been proposed to develop electromotive force or current mentions, which can be about independent to temperature and power supply voltage.The bandgap mention is the major design to supply a preciseness electromotive force mention with low sensitiveness to the temperature and the power supply.when CMOS engineerings enter the nano-scale epoch, The demand for battery operated portable equipments will increase.the supply electromotive force has been scaled down from 1.8V ( in 0.18 µm engineering ) to 1.2V ( in 0.13 µm engineering ) , and will drop to merely 0.9V in the following coevals engineering [ 2 ] .In CMOS engineering, the parasitic perpendicular bipolar junction ( BJT ) had been normally used to implement P-N junction of the bandgap reference.But the traditional CMOS bandgap mention circuits did non work in sub 1-V supply voltage.the ground, that the minimal supply electromotive force can non be lower than 1V is constrained by two factors, which is the bandgap electromotive force of around 1.25V in Si, which is exceeds 1V supply.The others factor is the low-tension design of the relative to absolute temperature current coevals cringle is limited by input common-mode electromotive force of the amplifier.These two limitions can be solved by utilizing the resistive subdivision methods, low threshold electromotive force ( or indigen ) device, BiCMOS procedure or DTMOS device.However, those attacks frequently require specialised procedure and word picture which addition fiction cost and procedure stairss. Reference electromotive force generators are required to be stabilized over procedure, electromotive force and temperature fluctuations and besides implemented without alteration of fiction process.The bandgap mention ( BGR ) is one of the most popular mention electromotive force generators that successfully achieve the requirements.regarding the generators, the demand for the low power and low electromotive force operation is strongly increasing the spread of the battery-operated portable applications.A bandgap mention electromotive force is an indispensable constituent of an analog-to-digital converterIt is frequently used to provide a mention electromotive force which is compared with others voltage. A bandgap mention electromotive force with low sensitiveness to temperature and supply electromotive force is normally required in parallel or digital circuits.there are several methods to recognize a temperature independent voltage.the base emitter junction used as a nucleus constitu ent of the bandgap mention is the most popular approach.the general bandgap mention electromotive force mention electromotive force is described by a additive combination of base-emitter electromotive force. Bandgap mention circuit is widely used to supply stable current and electromotive force mentions in parallel circuits every bit good as in assorted signal CMOS circuits.A stable mention circuit should be robust against temperature, power supply and procedure variations.Sub-1-V mention coevals has got importance due to scaling ensuing in shrinking of MOS dimensions and decrease of power supply to minimise power ingestion. owing to follow Moore ‘s Law, it has become needfully of import to diminish the power in the chip.This puts the restraint on the power dissipation of mention generators.the design of this bandgap besides see for low power operation..In traditional BGR circuit, bipolar transistors and one or more resistances are used.BJTs that are used in BGR are in parasitic signifier in CMOS.resistor occupy big country on the bit and hence addition the cost.on bit tolerance of resistances vary from 20 % to 30 % .So, we have to replaced these constituents with MOS transistors t o better public presentation of BGR and to salvage bit area.The combination of different runing parts like subthreshold, additive and impregnation of MOS suppresses the temperature dependance of electromotive force mention.Aims:To set up a dc electromotive force or current that is independent of the supply and procedure and has a chiseled behaviour with temperature. To plan the BGR that independently to temperature and low noise and low electromotive force To plan bandgap mention that can be successfully operated with sub 1-V supply in standard 0.35 CMOS procedure without particular procedure engineering.Problem statementWhen CMOS technologies enter the nano-scales epoch, the demand for battery-operated portable equipments will increase.The supply electromotive force has been scaled down from 1.8V ( in 0.18 m engineering ) to 1.2V ( in 0.13 engineering ) and will drop to merely 0.9V in the following engineering [ 2 ] .in CMOS engineering, the parasitic perpendicular bipolar junction transistor ( BJT ) had been used to implement the high preciseness bandgap electromotive force references.However, the convential BGR generates a 1.25V mention voltage.Its fixed end product electromotive force limited the supply electromotive force and non suited for sub 1-V supply volateg operation.The ground why the conventional CMOS bandgap mention did non work in close 1-V supply voltage.One is that the bandgap end product electromotive force is about 1 .25V [ 3 ] , which exceeds 1-V supply.The others is that the low temperature electromotive force design of the relative to absolute temperature current coevals cringle is limited by the input common-mode electromotive force of the amplifier.These two restrictions can be solved by utilizing the resistive subdivision method [ 4 ] , low threshold electromotive force device [ 5 ] , BiCMOS procedure or DTMOST [ 6 ] . But, those attacks frequently require specialised procedure and word picture which can increase fiction cost and procedure step.However, the bandgap mention working in low supply electromotive force has a higher temperature coeeficient than that of traditional bandgap reference.This resulted in the development of new temperature compensated techniques such as quadratic temperature compensation [ 7 ] , exponential temperature compensation [ 8 ] , piecewise additive curvature rectification [ 9 ] and resistance temperature compensation [ 10 ] .To implement these advanced mathem atical maps with high truth, the development of the low electromotive force bandgap construction requires precision matching of current mirrors or a pre-regulated supply electromotive force, cascade current mirror [ 11 ] , and pre-regulated circuit are good methods to work out this problem.but the minimal supply electromotive force is tradeoff.Scope of work:A typical CMOS execution of a bandgap mention is shown in Fig. 1. The end product mention electromotive force VREF of the traditional bandgap mention circuit can be written as: Equation 1 trad bgr.bmp Figure 1: Traditional/conventional BGR circuit in CMOS engineering where A1 and A2 is the emitter countries of Q1 and Q2, and VT is thermic electromotive force. The 2nd term in ( 1 ) is relative to the absolute temperature ( PTAT ) , which is used to call off the negative temperature coefficient of VEB. Hence, if a proper ration of resistances is kept, an end product electromotive force with lowsensitivity to the temperature can be obtained. In general, the VREF is about 1.25 V, so that the conventional bandgap mention circuit can non be used in low electromotive force application, such as 1 V. Mention electromotive forces and/or currents with small dependance to temperature turn out utile in many parallel circuits. As many procedure parametric quantities vary with temperature, if a mention is temperature-independent, it is normally processindependent every bit good. If two measures with opposite temperature coefficient are added with proper weighting, the attendant measure theoretically exhibits zero temperature coefficient. The construct of the new proposed bandgap mention is that the two electromotive forces ( which are relative to VEB and VT ) are generated by merely one feedback cringle. The two-stage operational amplifier with p-channel input is used in thisnew proposed bandgap mention. The new proposed bandgap mention is shown in Fig. 2, which uses the resistive subdivision R1a, R1b, R2a and R2b to cut down the input common-mode electromotive force of the amplifier.The dimensions of PMOS devices M1 and M2 are the same.The opposition of R1a and R2a is the same, and th e resistanceof R1b and R2b is the same. Following the KCL at the nodesof V1 and V2 in Fig. 2, the mention electromotive force can be expressed as New Picture.bmp Equation 2 Where and.According to equation below: ) /R4 We can expressed equation 2.The point of Vref-conv is indistinguishable to the conventional mention electromotive force in equation ( 1 ) .In order to accomplish sub 1-V operation, the ratio of R1b/ ( R1a+R1b ) is used to scale down the mention electromotive force level.Therefore, the minimal supply electromotive force of the new proposed BGR can be efficaciously reduced to merely. The new proposed BGR mentions can operated under bomber 1V.The whole complete circuit to recognize the proposed bomber 1V BGR is shown below: New Picture ( 1 ) .bmp Figure 2: Complete circuit for new proposed Sub1V So, from the comparing above, I can clearly cognize what I will make on my ain undertaking, what my range of work.From this, i ‘ll go on the new proposed BGR design that already done but I will seek to minimise the supply electromotive force, temperature independent and noise consequence as possible so the BGR will successfully operated in sub 1-V.

Differences in memory management between Windows and Linux Essay

Differences in remembrance focus between Windows and Linux Windows and Linux are two of the just ab divulge commonly utilise operate systems to date. Windows is used more by beginners and everyday information litigateing system users, period Linux is used more by advanced users and is dubbed the hackers operating(a) system. some(prenominal) the operating systems pee their advantages and their disadvantages. This paper ordain be differentiate the two in the operating systems retrospect wariness aspect. Windows manages their virtual repositing in a direct info construction. Each client in the tree is called a virtual address descriptors (VAD). virtual(prenominal) memory descriptors mark each node on the tree as free, reserved, or committed virtual memory. A process organisms with all addresses free which means they croup be committed to memory or be reserved for future use. onward any free address asshole be used it has to first be allocated as reserved or committ ed. Linux uses a relate list selective information structure which is stored in the vm_area_struct structure and defined in .The link list data begins hunting whenever a page is found and records the cast off of address, protection mode, and the direction in which it grows. If the minute of entries becomes greater than 32, Linux bequeath convert the linked list into a tree data structure depending on the new situation. Both Windows and Linuxs memory focus systems riddle the process virtual address office in a similar manner. By using paging, Windows on 32bit systems will affirm access up to a 4GB of standalone ordered address space and physical memory. The top(prenominal) role of the address space is allocated with 2GB of memory for windows kernel-mode, while the lower part is in any case allocated with 2GB of memory for user-mode. While Linux can also access 4GB of physical memory the residuum is the upper part is allocated with 1GB of memory for kernel-mode, while the lower part is allocated with 1GB for user-mode.An important part in any memory management system is the page surrogate system. varlet replacement decides which memory pages to page out when a page of memory call for to be allocated. Windows uses cluster demand paging, which pages are brought in the memory when they are bespeaked. It will also bring one by dint of eight pages in memory concurrently instead of bringing them one by one. Windowspaging system uses a work set concept, which is determined by make out of memory assigned in the current process. It contains pages that are in the main memory which the size of the working set will be altered accordingly. The page replacement algorithmic rule used for Windows is, premier in, First Out algorithm (F.I.F.O). Linux on the a nonher(prenominal) hand uses demand paging so any pages no needed will not be swapped into the memory.Therefore, pages not being used will be avoided and not be read. It will also decrease the amoun t of physical memory and the metre used to swap the pages. Linux also uses reasoned and non-valid bits to identify between pages that are in memory and disk. The page replacement algorithm used for Linux is, Least Recently utilize algorithm (L.R.U). While both Windows and Linux wealthy person their advantages and disadvantages in the operating system. They both have complex memory management systems which fulfills the users need when choosing an OS. With time we can only cypher the complexity of the future memory management systems in both Windows and Linux.ReferencesFelixbytow. (2012, July 08). FAQ/LinkedLists. Retrieved from KernelNewbieshttp//kernelnewbies.org/FAQ/LinkedListsKath, R. (1993, January 20). Managing Virtual Memory. Retrieved from Microsofthttp//msdn.microsoft.com/en-us/ program program library/ms810627.aspxRparrett. (2012, 08 22). About Memory Management. Retrieved from Windowshttp//msdn.microsoft.com/en-us/library/windows/desktop/aa366525%28v=vs.85%29.aspxRusl ing, D. A. (1996-1999). Memory Management. Retrieved from TLDPhttp//www.tldp.org/LDP/tlk/mm/memory.html