Empiricism Is The Theory That Experience - 1202 Words

Empiricism is the theory that experience, rather than reason, is the source of knowledge, and in this sense it is opposed to rationalism. This general thesis can receive different emphases and refinements; therefore, philosophers who have been labeled empiricists are united generally and may differ in various ways. The Empiricist Revolution helped facilitate discussion on real world, political problems. Since this revolution, philosophers and political theorists have developed two different ideas on what politics should be about and how a government should be ran: politics should be about making citizens more virtuous vs politics should be about the â€Å"basics† like security and property rights. Throughout this paper, I will be analyzing these two different outlooks on politics and presenting a case for both. Thomas Hobbes believed that the government should essentially limit itself to the protection of property and persons. Hobbes thought that power derived from the office, not from the people. Things like virtue, social equality, and welfare were not important. To protect themselves and their government Hobbes believed that it was imperative, natural and rational for people to give up some liberty in order to gain security of self-preservation. This is called the Social Contract. The concept of the Social Contract Theory is that, in the beginning, man lived in the state of nature where life was, â€Å"solitary, poor, nasty, brutish, and short† (page 619). In this state everyShow MoreRelatedEmpiricism Vs. Positivist Theory Of Knowledge1053 Words   |  5 Pages One of the theories found in epistemology is the theory of empiricism. Empiricism is the belief that knowledge is gained through experience, that there is no such thing as â€Å"innate knowledge,† or knowledge that one is born with. Empiricism stands in stark contrast to the rationalist theory, the belief that humans possess innate knowledge, and that one can have knowledge, without sensory information or experience, through reason. In this paper I will evaluate the theory of empiricism, comparing itRead MoreThe Feminist Philosophy Of Science Essay1712 Words   |  7 Pagesand means to rectify this. There are three main distinctions of feminist philosophy of science - feminist empiricism, standpoint theory, and postmodernism. I am to be comparing and contrasting two of the three, specifically feminist standpoint theory and empiricism. I shall argue that standpoint theory and empiricism are both legitimate methods for feminist epistemology, yet standpoint theory is a more applicable and plausible method for the analysis of science in particular. I will first explainRead MoreThe Phenomenology Of Perception By Maurice Merleau Ponty Essay1325 Words   |  6 Pagesissues of both empiricism and in tellectualism to explain his existential analysis of Being. Merleau-Ponty establishes against empiricism and intellectualism, the primary and complex ambiguity of our lived and embodied experience, and our inexhaustibility of being-in-the-world. In his critiques of these classical forms of intellectualism and empiricism, he identifies both what works for his phenomenological account and what doesn’t work. This essay will explain these critiques of empiricism and intellectualismRead MoreAn Essay About Natural Attitude and Preconceptions 1388 Words   |  6 Pagescertain fundamental axioms, ideas or assumptions are often taken for granted. To understand what natural attitude and preconceptions are, consider yourself as somebody who has never been influenced by any external conception – no knowledge and no experience. You have never been shown the correct way to perceive something or do anything. Imagine what your world would be like. For this, consider an example: Consider a person who has no concept of a particular object, say a book. The person has no ideaRead MoreEssay on Rationalism vs. Empiricism: The Argument for Empricism855 Words   |  4 Pagesrationalism and empiricism. These two, very different, schools of thought attempt to answer the philosophical question of how knowledge is acquired. While rationalists believe that this process occurs solely in our minds, empiricists argue that it is, instead, through sensory experience. After reading and understanding each argument it is clear that empiricism is the most relative explanatory position in epistemology. To begin with the question of rationalism versus empiricism, it is importantRead MoreEmpiricism, Positivism, And Positivism Essay1421 Words   |  6 Pageskinds of investigation in the world. We also refer it as â€Å"empiricism†, the scientific way we gain our knowledge from experience. Empiricism is also a view that all kinds of knowledge come from, not just scientific knowledge. Scientific thinking and investigation have the same basic pattern as everyday thinking and investigation. (Godfrey-Smith, 9) Again, we call it â€Å"empiricism† in terms of philosophical way, but in earliest form, the â€Å"empiricism† was referred as â€Å"logical positivism†. Logical PositivismRead More Poes Fall of The House of Usher Essay: Beyond Empiricism and Transcendentalism1482 Words   |  6 PagesBeyond Empiricism and Transcendentalism in House of Usher      Ã‚   When Edgar Allan Poe wrote The Fall of the House of Usher, two factors greatly influenced his writing. A first influence was John Lockes idea of Empiricism, which was the idea that all knowledge was gained by experiences, exclusively through the senses. A second vital influence was Transcendentalism, which was a reaction to Empiricism.   While John Locke believed that reality or truth was constituted by the material world andRead MoreEmpiricism and Rationalism Essay1020 Words   |  5 Pagesâ€Å"dependent upon sense experience†. (Markie, 2008, section 1.2) Yet, philosophical empiricism is defined in such an absolute way; which causes philosophical empiricism to be an inaccurate philosophical position from which to address all aspects of human life. Philosophical empiricism is defined as â€Å"the belief that all human knowledge arises from sense experience.† (Nash, 1999, page 254) Yet, medical empiricism is so far to the other extreme as to be insulting , while this empiricism is still said toRead MoreKarl Popper And The Scientific Method1372 Words   |  6 Pagesformulate a law or theory. Popper rejected the inductivist viewpoint in favor of a theory called empirical falsification which holds that a theory can never be proven, but it can be falsified, and therefore it can and needs to be scrutinized through experimentation. In his work â€Å"Conjectures and Refutations,† Popper discussed several aspects of induction including the topics of conjectures (opinions or conclusions formed on the basis of incomplete information) or tentative theories and refutationsRead MoreRen?ï ¿ ½ Descartes And Immanuel Kants Theory Of Knowledge905 Words   |  4 PagesIn 18th century Europe, philosophers widely sought after knowledge. More specifically, they sought after the knowledge of how knowledge might be found. Two main philosophies stood in opposition: rationalism and empiricism (Sproul 117). Immanuel Kant, a revolutionary philosopher from East Prussia, endeavored to create a synthesis of the two philosophies (119). This synthesis illustrated a process by which knowledge might be obtained through both ways illustrated in the two philosophies. This synthesis

Production of Fiber Reinforced Thermoplastic Composites free essay sample

The growing interest in the past to produce green materials that can reduce the problem involving waste materials by non-fibrous materials led to the development of natural fiber reinforced thermoplastic composites. Water Hyacinth (Eichhornia crassipes) also known as â€Å"water lily† is an aquatic plant which is found floating freely in the surface of fresh waters. Its rate of proliferation under certain circumstances is extremely rapid and cause infestations over large areas of water leading to a variety of problems. Hence, water hyacinth can be obtained without any additional cost. Water hyacinth is considered the most productive plant on earth as it yields more than 200 tons of dry matter per hectare per year under normal conditions. On water containing high concentrations of sewage, it yields up to 657 tons of dry matter per hectare. Water hyacinth fiber, the subject of the present study, is a waste product and found to be a potential for reinforcement in plastics. We will write a custom essay sample on Production of Fiber Reinforced Thermoplastic Composites or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page Recently, a lot of researches produced fiber reinforced materials. Reinforcements with polyethylene, polypropylene and other thermoplastic polymers are mixed to produce efficient composites. Natural fibers including wood, kenaf, coir, pineapple, rice starch and etc. are used to combine with the polymers. Addition of fibers in the materials will affect the mechanical, thermal and water absorbent properties. Although, many researchers experimented with different types of organic materials, there have been a few studies on water hyacinth and its fibers. A fiber based biocomposite material contains polymers reinforced with natural fiber using natural fibers in biocomposites has various advantages, among which are: a) the material made from natural fibers will make it partially biodegradable; b) some fiber-based composites is somewhat expensive to make; c) natural fiber, in this research water hyacinth, is currently disposed and just decompose if not used. Likewise, Table 1. 1 shows some advantages of commercial composites as well as its disadvantages resulted from the study conducted by Peter (2002). Table 1. 1: List of Advantages and Disadvantages of Comm. Composites. (Peter, 2002) ADVANTAGES DISADVANTAGES Longer life (no corrosion ),better fatigue life Matrix Weakness Reduced weight Difficult to attach Reduced manufacturing costs Non-destructive testing tedious Increased/Decreased thermal or electrical Transverse properties may be weak Conductivity One good application of fiber reinforced thermoplastic is possible for ceiling tiles. Ceiling tiles are lightweight, inexpensive and attractive and can be used in a variety of ways: crafts, photo backdrops, sound control, wall decor and more. The researchers will be utilized water hyacinth fibers as thermoplastic composites for ceiling tiles. Commercial Ceiling Insulation System 1. 2 STATEMENT OF THE PROBLEM This study aimed to produce reinforced thermoplastic ceiling tiles using water hyacinth (Eicchorniacrassipes) fiber by compression molding. Specifically it aimed to: 1. Produce fiber reinforced thermoplastic treated and untreated with coupling agent from fibers of water hyacinth (Eicchorniacrassipes). 1. 1 0% (control) 1. 2 10% fiber mix 1. 3 20% fiber mix 1. 4 30% fiber mix 2. Determine the physical and mechanical properties of the fiber reinforced thermoplastic ceiling tiles treated and untreated with coupling agent. Tensile strength 2. 2 Water absorption 2. 3 Flame Retardancy 3. Identify the product with the best physical and mechanical properties will be compared to thecommercially available plywood. 1. 3 SIGNIFICANCE OF THE STUDY Here in the Philippines, particularly in Laguna de Bay, water hyacinth is considered a nuisance. â€Å"These plants now cover some 20% of the lake’s surface area,† said Edgardo Manda, general manager of Laguna Lake Development Authority. He added that such proliferation threatens survival of aquatic species there since these plants block sunlight’s penetration into the water. This research can help in reducing propagation of water hyacinth by utilizing these plants’ fibers in the production of a new product that may be used as a substitutefor the commercial ceiling insulation materials. This study is beneficial to the individuals who produce thermoplastic ceiling tiles, which has a good tensile strength and to set further development of thermoplastic composites. Lastly, the study aimed to benefit future researchers as to do further study and to utilize effective reinforcement of fibers to produce thermoplastic ceiling tiles. 1. This study focused on the synthesis of fiber reinforced plastic from water hyacinth (Eicchorniacrassipes) and to determine the effects of coupling agent, acetic anhydride, to the tiles. The size of the desired sample will be 7. 5† x7. 5† x 0. 5mm. The study also focused on the physical properties, particularly the tensile strength, flexural strength, water absorption test, and flame retardancy. The scope included compounding of water hyacinth fiber and polypropylene using two-roll mill machine, and molding by compression molding machine only. Therefore, the study did not cover the biodegradability, other methods of molding, the orientation of the fibers mixed with the matrix and the production cost of the thermoplastic ceiling tiles as the financial and the time span of the study suggests. The product was compared to plywood. 1. 5 DEFINITION OF TERMS Brominated flame retardants these accounts for 21% by weight (32% by value) of all flame retardants worldwide and are suitable for many types of plastic. Ceiling tiles- a horizontal surface that forms the top part or roof inside a room. Composites – pertains to materials made with two or  more constituents with observable difference in physical and chemical properties Flame Retardant Flame retardants are chemicals which are added to many materials to increase their fire safety. For example, many plastics are highly flammable and therefore their fire resistance is increased by adding flame retardants in order to reduce the risk of fire. Flexural Test – test for the maximum stress in the outermost fiber. This is calculated at the surface of the specimen on the convex or tension side. Matrix – a material in which the reinforcement material is embedded. Tensile Strength a measure of the ability of a material to withstand a longitudinal stress, expressed as the greatest stress that the material can stand without breaking Thermoplastic – is a type of plastic that becomes liquid when heated and turn into glass-like material when frozen. Water Absorption The amount of water absorbed by a composite material (water hyacinth fiber reinforced plastic) when immersed in water for a stipulated period of time. Water Hyacinth – is an aquatic plant found in the surface of the fresh water. CHAPTER 2 Conceptual Framework/ Plastics have been one of the most highly valued materials mainly because of their extraordinary versatility and low cost. Figure 2. 1. Classification of Bioplastics Adopted from Handbook of Bioplastics and BiocompositesEnginnering Application, (Pilla, 2011) Bioplastic and plastic can be produced with three possible sources as shown in Figure 2. 1. First, it came from the most common source the petroleum, then, from thestarchy material and lastly, from the cellulosic material. Today, plastic derived from petroleum products are widely used. Many studies already conducted application of product containing starch turn into plastic. Sriroth et. al. (2000) made plastic from cassava starch and other researchers conducted experiments to produce plastic with another different starch containing products. The natural fibre extracted from different sources has shown promising results as reinforcement to thermoplastics. When isolated into nano scale, these fibres have values of tensile strength and modulus comparable to glass fibre. Natural fibres are lightweight material, with properties of high specific modulus, non-abrasive in the processing equipments, renewable, biodegradable and  recyclable that allows them to compete against other man-made materials like fossil materials and fibreglass. The rapid growth of natural fibre composites is related to economic, technological, social and environmental issues. (Souza et. al. 2010) 2. 2 CELLULOSE FIBERS In the study conducted by Sullivan (1996), cellulose derived from plants are investigated and found the possible pre-treatments and explained the parts of the fiber obtained. The structure is defined and how it acts as potential use for advance in plastic technology. Cellulose fibers are found to have their thermal stability with noticeable degradation occurring as the melt processing temperature approaches 200oC. This excludes some manufacturing processes and limits the type of thermoplastic that can be used as matrix material like polypropylene, polystyrene and polyethylene. Typical chemical composition of a water hyacinth material is listed on Table 2. 1. It clearly shows that on a dry basis, water hyacinth contains greater percentage of hemicellulose in it, next is the cellulose and the least content is the lignin. Table 2. 1. Chemical Composition of Water Hyacinth (Poddar et. al. , 1991) Component Wt % Moisture Cellulose 85-95 Organic matter (dry basis) 18-31 Hemicelluloses 18-43 Lignin 7-26 Ash (dry basis) 15-26 2. 3 ALKALI TREATMENT ON CELLULOSE Alkali treatment on cellulose is a chemical method which can change the constituents of fibers. The alkali treatment causes swelling, leading to an increase in internal surface area, a decrease in the degree of polymerization, a decrease in crystallinity, separation of structural linkages between lignin and carbohydrates, and disruption of the lignin structure. The primary functions of the matrix are to transfer stresses between the reinforcing fibers (hold fibers together) and protect the fibers from mechanical and/or environmental damages. A basic requirement for a matrix material is that its strain at break must be larger than the fibers it is holding. Typically, the matrix has a considerably lower density, stiffness (modulus), and strength than those of the reinforcing fiber material, but the combination of the two main constituents (matrix and fiber) produces  high strength and stiffness, while still possessing a relatively low density. Most matrices are made of resins for their wide variation in properties and relatively low cost. Common resin materials include epoxy, phenolic, polyester, polypropylene, polyurethane, and vinyl ester. Among these resin materials, polyesters are the most widely used. Epoxies, which have higher adhesion and less shrinkage than polyesters, come in second for their higher costs 2. 5 COUPLING AGENT A coupling agent improves the bond between filter and resin. A coupling agent for glass fibers is called a coupling finish. This term is not to be confused with coupling size, which is a lubricant that facilitates operations like winding. (Elias, 2003) Fiber to matrix adhesion plays a very important role in the reinforcement of composites with short fibers. To have composites with excellent mechanical properties, the load must be transferred effectively from the matrix to fibers. Although mechanisms of stress transfer are not clear, it has been postulated that it takes place through shearing interface. A lot of studies have been conducted on various composite materials either to improve the efficiency of the interface in transferring stress or to understand the mechanism involved. According to Elias (2003), there are two types of coupling agents: Non-reactive and reactive coupling agents. Non-reactive coupling agents such absorb on the surface of the fillers. They establish physical bonds (hydrogen bonds, dipole-dipole and/or van der Waals interactions between the agent and the resin molecules. On the other hand, glass fibers and several mineral fillers such as clays, mica, kaolin, and aluminum trihydroxide (ATH) are treated with reactive coupling agents, mainly silicon derivatives. Coupling agents typically have fairly low molecular weight chemicals with chemical end groups (functionality) for chemical reaction to both an inorganic particle surface (normally a particle, of nanometric or micron size, or a fibre) with one of the end groups and to a polymer molecule with the other end. They may be also used to bond polymers onto metallic surfaces. (Nelson,2010) Esterification is the chemical process for making esters, which are compounds of the chemical structure R-COOR, where R and R are either alkyl or aryl groups. The most common method for preparing esters is to heat a carboxylic acid, R-CO-OH, with an alcohol, R-OH, while removing the water that is formed. A mineral acid catalyst is usually needed to make the reaction occur at a useful rate. Esters can also be formed by various other reactions. These include the reaction of an alcohol with an acid chloride (R-CO-Cl) or an anhydride (R-CO-O-COR). Early studies into the chemical mechanism of esterification, concluded that the ester product (R-CO-OR) is the union of the acyl group (R-C=O-) from the acid, RCO-OH, with the alkoxide group (RO-) from the alcohol, R-OH rather than other possible combinations. (Loudon, G. Mark. OrganicChemistry. Oxford: Oxford University Press, 2002. ) 2. 7 COMPOSITES There are several types of composites, the polymer matrix composite, metal mix composite, ceramic matrix composite and carbon-carbon matrix composite. Before, cellulosic fillers became a potential to replace non-fibrous fillers as the application of thermoplastic materials became popular. But then, lack of good surface adhesion of substances and poor resistance to moisture absorption made the reinforced composites unappealing. Various methods have been done to increase the adhesion of the materials used for reinforced composites like isocyanate, acrylation, latex coating, acetylation, peroxide, permanganate, silane and alkali treatment as coupling agent have been carried out to improve the properties of the thermoplastic composite. The manufacture of fiber-reinforced composites has multi-step process which includes the extraction of the fiber from the plant, chemical treatment to reduce it to its fibrous form and reduced its size and combined with synthetic polymer material. Techniques are then used to mold the final product. Even though plastics are thought of a common problem, still, it is believed that this new advance should suggest the chance for reduced environmental issues, reduced energy consumption, light weight, insulation and reduced dependence on petroleum and wood based products. Polymer can be divided into two groups according to their thermal processing behaviour, thermoset and thermoplastic. Thermoplastic composites are composites that use thermoplastic polymer as a matrix. These plastics can be melt processed by a variety of method including extrusion and molding, like polyethylene, polypropylene, polystyreneand polyvinyl chloride. A thermoplastic polymer is a long chain polymer that can be either amorphous in structure or semi-crystalline. These polymers are long chain, medium to high molecular weight materials, whose general properties are those of toughness, resistance to chemical attack and recyclability. Thermoplastic polymers used in thermoplastic composites can be divided into two classes, high temperature thermoplastics and the engineering thermoplastics. The classification is based on the maximum service temperature of the polymers, which in turn is based on the Glass Transition (Tg) temperature. This is the temperature at which the amorphous portion of the polymer changes from a glassy to a rubbery phase on heating. Thermoset polymers may not usefully carry mechanic loads above Tg, but semi-crystalline thermoplastic polymers may carry load above Tg, as only the amorphous phase of the polymer has become rubbery. The crystalline portion of the polymer remains solid until the melt temperature, Tm. 2. 9 POLYPROPYLENE 2. 9. 1 Properties of Polypropylene Polypropylene has a linear structure and its monomer (or the basic structural unit that binds together to form the chain) is represented by the formula of CnH2n, where n is the number of atoms. Its cost of production is not very high. It can be obtained from propylene gas with the help of titanium chloride as a catalyst. Some of the essential properties of polypropylene are as follows: Weight Polypropylene is a lightweight material. Tensile strength Its tensile strength is quite high. It shows strong resistance towards stress and cracking. Shape Polypropylene is crystalline in nature and possesses a regular geometrical shape. Insulation It acts as an excellent insulator. That means, polypropylene prevents flow of electricity through it. Moisture Absorption Polypropylene does not get damaged by water exposure because its moisture absorption is very low. Melting Point Melting point of polypropylene is 160 °C. Therefore, unlike other polymers like polyethylene, it is capable of being operational at a very high temperature. Corrosion This polymer remains unaffected when it comes in contact with chemicals such as alkaline substances, acids, de-greasing agents, electrolytic attacks, etc. However, its resistance towards aromatic or aliphatic hydrocarbons, chlorinated solvents and ultraviolet radiation is not very strong. Other useful properties: Basically, it is a non-toxic substance. It does not get stained very easily. It can be easily fabricated. It can retain its stiffness and flexibility intact even at very high temperatures. Figure 2. 2: Structure of Polypropylene 2. 10 TENSILE TESTING Tensile test is a measurement of the ability of a material to withstand forces that tend to pull it apart and to what extent the material stretches before breaking. The stiffness of a material which represented by tensile modulus can be determined from stress-strain diagram. 2. 11 FLEXURAL STRENGTH Flexural strength is the maximum stress in the outer specimen at the moment of break. When the homogeneous elastic material is tested with three-point system, the maximum stress occurs at the midpoint. This stress can be evaluated for any point on the load deflection curve using equation (2. The absorbed moisture affects the fibre/matrix interface and hence the mechanical and physical properties of the composites. The reduced effect of moisture absorption on the mechanical properties has been attributed to the improved fibre/matrix bonding which reduce the moisture-caused fibre-matrix debonding. The molar absorption of water by the composites at the given interval time Q was calculated from (Springer, 1981): Where W1 is the weight of the dry sample and W2 is the weight of wet sample. 2. 13 FLAME RETARDANT Flame retardant are substances that can be chemically inserted into the polymer molecule or be physically blended in polymers after polymerization to suppress, reduce, delay or modify the propagation of a flame through a plastic material. Antimony Trioxide as flame retardant Antimony Trioxide is used mainly in fire retardant formulations for plastics, rubbers, textiles, paper and paints. Further, Antimony Trioxide can be used as an additive in glass and ceramic products and as a catalyst in the chemical industry. Occupational exposure may occur during mining, processing and smelting of antimony ores, in glass and ceramics production, and during the manufacture and use of products containing antimony trioxide. Antimony trioxide and pentoxide do not react as flame-retardants directly. Applications include: for wide range of plastics, rubbers, paper and textiles, catalyst in PET production, activator in glass industry, flocculant in titanium dioxide production, paints and adhesives industries, pigments and ceramic frites. According to Yepez (2005) the most commonly used for testing flammability is Match Flame Test. This requires small scale fire tests. Specimen must be dry and exposed to flame from a common wood kitchen-type match. During the exposure, flaming shall not spread over the complete length of the sample or in excess of 4 inches from the bottom of the sample. There shall not be more than two seconds after flame. Material that break and drip flaming particles shall be rejected if the materials continue to burn after they reach the floor. 2. 15 Antimony Trioxide as Fire Retardant This is a synergistic flame retardant which is always used with either brominated flame retardants, chlorinated flame retardants or chlorinated polymers such as PVC. It is very effective at fairly low concentrations so that the amounts of brominated flame retardant used can be halved. Typically about 3% antimony oxide can replace about 10% of brominated flame retardant. CHAPTER 3 Review of Related Literature 3. 1. Reinforcement of Cellulose fibers Reinforcement of cellulose fibers in composite materials started since grass and straw were used as reinforcement in mud bricks. The use of reinforcement in the past is widely used in automotive industry. The sources of fibrous material according to the part of the plant are classified as: 1. Leaf Fibers – the fibers run lengthwise through the leaves of most monocotyledonous plants including sisal, abaca and the like. 2. Bast Fibers – the fibers come from the inner bark of the stems of dicotyledenous plants including hemf, kenaf, jute and flax 3. Grass or reeds – the fibrous part is found in the stems of monocotyledonous plants which includes bamboo and sugar cone. 3. 2 Modifications Modifications can be made in order to produce quality plastic. There are examples of reduced energy demand by applying pre-treatments before mechanical treatments and successfully isolated cellulose materials (Henrikkson et. al. , 2007; Paakko et. al, 2007) Nakagaito and Yano (2008), modified nanocellulose fibers by NaOH treatment, which resulted in superior performance of the fibers and a further improvement in the toughness and elongation. Most cellulose and microcellulose is obtained from forestry products as forests are large and in some countries an important resource. On the other hand, agricultural fibers also offer cellulose and recent studies have shown that fruit-based agricultural fibers can be used to obtain this kind of material. Habibi, et. al. (2009), extracted cellulose from pear fruits while Zuluaga et. al. (2009), obtained nano-fibers from banana. There are many ways on how to produce cellulose material. Pohleret. al. (2010) characterized the different outcomes with different chemical pre-treatment and methods and evaluated each. Modification includes the physical combination of two polymerand the combination of the non-polymetric material. Usually the characteristics of composites include comprise high strength, high modulus, low density and excellent resistance to fatigue, creep rupture, corrosion and wear. Polypropylene is commonly used as matrix of composite as it has low processing temperature (below 230o) which will not degrade the fiber. Polypropylene is one of the successful commodity synthetic polymers. It is commonly used because of its low density (0. 905 g/cm3), high crystallinity, stiffness and toughness. (Supri 2009) In the presence of a coupling agent, the water uptake was reduced as better interfacial bonding was proven. 3. 3 Alkaline pre-treatment Alkaline pre-treatment disrupts the lignin structure and helps to separate the structural linkages between lignin and carbohydrates. (Dufresne et. al. , 1997; Wang and Sain, 2007) Alkaline pre-treatment should be controlled to avoid undesirable cellulose degradation and to ensure that hydrolysis occurs only at the fiber surface (Bhatnagar and Sain, 2005; Wang and Sain, 2007) so that intact nanofibers can be obtained. Table 3. 1 List of some coupling agent studied for cellulosic materials and plasticsystems. Chtourou, et. al. 1992, Gatenholm, et. al, Anhydride 1992, 1993. Rozman et. al, 1994. Maldas andKokta, 1989, 1990, 1991. Epoxides Rowelle et. al. 1982 Silane Beshay et. al. , 1985; Raj et. al 1989,1990. Nelson J. K (2010) also gave emphasis to the significance of a coupling agent. The importance of a coupling agent to the surface of a particle is that it sets the stage for the quality and properties of the interface region involving the polymer matrix resumes its normal properties. Another importance of coupling agent, though not-always-stated, is to prevent interactions with, and interference from, the presence of water. Pre-treatments of natural fibers in fiber-reinforced composites repeatedly show improvement in tensile properties upon different modifications owing to the increased fiber-matrix adhesion. 3. 4 Cellulose Composites A composite is defined as a material that combines two or more distinct constituents or phases, where one or more discontinuous phases (reinforcements) are dispersed in another continuous phase (matrix) in order to obtain tailor-made characteristics and properties. (Mussig, 2010) Development of composites based on cellulosic material is rather new but rapidly evolving area. Polymer composites are a polymer matrix composite in which the fillers are less than 100 nm in at least one dimension. When the fillers or reinforcements are celluloses, the resulting composites are referred as cellulose composites or cellulose composites. (Schadler, et. al. , 2007) In 2001, Sarkar et. al. , made a study on the effects of alkali treatment on jute fibers which made alkali treatment as a potential to produce competent composite material. It is found that there was an improvement in the crystallinity in the jute fibers by an observable increase in modulus. Also, the percent breaking strain was reduced. (ICME 2011) It is concluded that the Young’s modulus, flexural strength, flexural modulus and impact strength of the water hyacinth-polypropylene composites increases as fiber loading increases. It is also found that all of the properties were better for treated water hyacinth-polypropylene composites than with raw water hyacinth-polypropylene composites. The tensile strength of the composites decreased with an increase of the water hyacinth fiber loading. But, the 15wt% treated water hyacinth fibers reinforced polypropylene composite revealed better tensile properties than equivalent raw water hyacinth-polypropylene composites. The water hyacinth fibers which were treated increased interfacial bonding between the matrix and fibers. Thermoplastics Based on book of Biron (2007), polymer composites are made from polymer matrix, thermoset or thermoplastics. Hybrids combine plastics or composites such as metal, wood and other source. The composite properties depend on the matrix used, the reinforcement material and how the adhesion effectively occurred between the fiber and the matrix based on different techniques that may be done in order to produce effective composites. The matrix ensured the cohesion, distribution and lessens the impacts and stresses to protect the product. Thermoplastics reinforced from polypropylene are found to have many applications like countertops, coatings and etc. as it exhibits high corrosion resistance, abrasion and impact resistance. Some of the studied systems, involving cellulosic material and thermoplastic matrices are listed below: Table 3. 2. List of some cellulosic material/ thermoplastic system studied System Studied

Reed Essays - Reed College, Reed, Employment, Business, Music

Reed How did you first become interested in Reed and why do you think Reed might be an appropriate place, both socially and academically, to continue your education? I could tell you a heartfelt, sentimental, poignant story about first seeing a Reed College refrigerator magnet (my uncle got it at a reunion, I think) and feeling first deep emotions stirring somewhere inside my spleen. Or I could meticulously paraphrase the numerous brochures and articles about Reed that I have perused. Yet another option would be to rent a small airplane and skywrite, I want to go to Reed, in colorful pollutants. And I probably would resort to one of these strategies, had I not some real incentives to attend Reed College. They are based on what I have learned from The Princeton Review, general knowledge, conversations I have overheard, and other miscellaneous tidbits of information sent to me by friends and relatives. First of all, I must express my admiration to the people who have decided that education is, after all, the purpose and responsibility of a college and established the precedence of academics over sports at Reed college. I'd like to attend a school where I, a debater, will not be viewed as a second-class citizen by football players. Secondly, the notoriety of great educational standards has reached me all the way in Vancouver (OK, so it is only across the river) and enticed, attracted, and urged me to apply to Reed. Rumors of the side effects of avalanches of homework and sleepless nights have crept here, too, but I'm up to the challenge. After two years of juggling high school, college, and extracurricular activities, receiving assignments only at one place just might be paradise. Lastly, Reed's geographical location is just like pretty wrapping paper and a big red bow on a present that's already great ( forgive the allusions to the Haagen-Dasz commercials). Living in Portland, I would be simultaneously away from my family in Vancouver--and as close as I might need to be! Not only would I have the opportunity to become better acquainted with Portland, but also to judge at debate tournaments for my old high school! The possibilities are mouthwatering. Jokes aside, I believe that attending Reed will be one of the most sensible things I might do in my whole life. Learning is what I do best, and at Reed I will have the perfect opportunity to excel at it. Acceptance Essays

The Revolutionary War Hero Ethan Allen

The Revolutionary War Hero Ethan Allen Ethan Allen was born in Litchfield, Connecticut in 1738. He fought in the American Revolutionary War. Allen was the leader of the Green Mountain Boys and along with Benedict Arnold captured Fort Ticonderoga from the British in 1775 in what was the first American victory of the war. After Allen’s attempts to have Vermont become a state failed, he then unsuccessfully petitioner to have Vermont become part of Canada. Vermont became a state two years after Allen’s death in 1789. Early Years Ethan Allen was born on January 21, 1738, to Joseph and Mary Baker Allen in Litchfield, Connecticut, Shortly after birth, the family moved to the neighboring town of Cornwall. Joseph wanted him to attend Yale University, but as the oldest of eight children, Ethan was forced to run the family property upon Josephs’ death in 1755.   Around 1760, Ethan made his first visit to the New Hampshire Grants, which is presently in the state of Vermont. At the time, he was serving in the Litchfield County militia fighting in the Seven Years’ War. In 1762, Ethan married Mary Brownson and they had five children.  After Mary’s death in 1783, Ethan married Frances Fanny Brush Buchanan in 1784 and they had three children. The beginning of the Green Mountain Boys Although Ethan served in the French and Indian War, he did not see any action.  After the war, Allen purchased land near the New Hampshire Grants in what is now Bennington, Vermont. Shortly after purchasing this land, a dispute arose between New York and New Hampshire over the land’s sovereign ownership. In 1770, in response to a New York Supreme Court ruling that the New Hampshire Grants were invalid, a militia named the â€Å"Green Mountain Boys† was formed in order to keep their land free and clear from the so-called â€Å"Yorkers†.  Allen was named as their leader and the Green Mountain Boys used intimidation and sometimes violence in order to force the Yorkers to leave. Role in the American Revolution At the onset of the Revolutionary War, the Green Mountain Boys immediately joined forces with the Continental Army. The Revolutionary War officially began on April 19, 1775, with the Battles of Lexington and Concord.  A major consequence of the â€Å"Battles† was the Siege of Boston whereby colonial militiamen surrounded the city in an attempt to keep the British Army from leaving Boston. After the siege began, Massachusetts military governor for the British, General Thomas Gage realized the importance of Fort Ticonderoga and sent a dispatch to General  Guy Carleton, Quebec’s governor, ordering him to send additional troops and munitions to Ticonderoga. Before the dispatch could reach Carleton in Quebec, the Green Mountain Boys led by Ethan and in a joint effort with Colonel Benedict Arnold were ready to attempt to overthrow the British at Ticonderoga.  At the break of dawn on May 10, 1775, the Continental Army won the first American victory of the young war when it crossed Lake Champlain and a force that numbered around one hundred militiamen overran the fort and captured the British forces while they slept. There was not a single soldier killed on either side nor were there any serious injuries during this battle. The following day, a group of the Green Mountain Boys led by Seth Warner took Crown Point, which was another British fort just a few miles north of Ticonderoga.   One major result of these battles was that colonial forces now had the artillery that they would need and use throughout the War. Ticonderoga’s location made the perfect staging ground for Continental Army to initiate their first campaign during the Revolutionary War – an invasion of into the British-held province of Quebec, Canada. Attempt to Overtake Fort St. John In May, Ethan led a detachment of 100 Boys to overtake Fort St. John.  The group was in four bateaux, but failed to take provisions and after two days without food, his men were extremely hungry. They came across on Lake St. John, and while Benedict Arnold provided the men food he also attempted to discourage Allen from his goal. However, he refused to heed the warning. When the group landed just above the fort, Allen learned that at least 200 British regulars were approaching. Being outnumbered, he led his men across the Richelieu River where his men spent the night. While Ethan and his men rested, the British began to fire artillery at them from across the river, causing the Boys to panic and return to Ticonderoga. Upon their return, Seth Warner replaced Ethan as the leader of the Green Mountain Boys due to their losing respect for Allen’s actions in trying to overtake Fort St. John. Campaign in Quebec Allen was able to convince Warner to allow him to stay on as a civilian scout as the Green Mountain Boys were participating in the campaign in Quebec. On September 24, Allen and about 100 men crossed the Saint Lawrence River, but the British had been alerted to their presence. In the ensuing  Battle of Longue-Pointe, he and about 30 of his men were captured. Allen was imprisoned in Cornwall, England for approximately two years and returned to the United States on May 6, 1778, as part of a prisoner exchange. Time After the War Upon his return, Allen settled in Vermont, a territory which had declared its independence from the United States as well as from Britain. He  took it upon himself to petition the Continental Congress to make Vermont the fourteenth U.S. state, but due to Vermont having disputes with surrounding states of over the rights to the territory, his attempt failed.  He then negotiated with Canadian governor Frederick Haldimand to become part of Canada but those attempts also failed. His  attempts to have Vermont become part of Canada which would have reunited the state with Great Britain, eroded the public’s confidence in his political and diplomatic capabilities. In 1787,  Ethan retired to his home in what is now Burlington, Vermont.  He died in Burlington on February 12, 1789. Two years later, Vermont joined the United States. Two of Ethan’s sons graduated from  West Point  and then serve in the  United States Army. His daughter  Fanny  converted to  Catholicism  and then she entered a convent. A grandson,  Ethan Allen Hitchcock, was a  Union Army  general in the  American Civil War.

How to Stop Procrastinating and Increase Concentration

How to Stop Procrastinating and Increase Concentration How to Stop Procrastinating and Increase Concentration No matter how close the deadline, sometimes your motivation to read, research, write and edit your paper can dwindle. This can be particularly bad if youre prone to procrastinating. The technology that surrounds us in everyday life means that there are endless distractions available. For those of us prone to procrastinating, getting work done can therefore be a challenge. However, there are also some practical steps you can take to improve the way you work, and therefore the quality of the work you complete. If you’re in the throes of a bout of procrastination and staring a deadline in the face, the following tips might be helpful. Get Rid of Online Distractions Even short periods spent on Facebook or Twitter can add up, and you spend more time taking quizzes to find out which Harry Potter character you are than researching your paper. To get rid of temptation online, install a program that blocks certain websites for a specified time. This allows you to work uninterrupted. Take Regular Breaks Some research suggests that the average persons attention span is roughly 8.25 seconds. Its probably not surprising that were so prone to procrastinating, if that is true. Especially since writing an assignment requires concentrating for longer periods. However, your ability to concentrate for longer periods decreases as you get tired, so regular (planned) breaks are essential. Even a short break of ten minutes every few hours can boost your concentration and efficiency. Breaks from work are also useful in a more general sense. Once you have completed a draft of a chapter or part of your paper, leave it for twenty-four hours. You will then be able to return to it with fresh eyes, making editing much easier. Take Exercise Exercise taken during the work day can boost concentration, motivation and time management. If possible, fit some form of exercise into your day. A brisk walk at lunchtime will improve not only your health and mood but also your concentration. Drink Water Staying well hydrated is vital for cognitive functioning, so concentration can be hindered if you aren’t getting enough fluids. Don’t forget to drink enough throughout the day, as by the time you feel thirsty, your brain power may have decreased by up to 10%. Create the Perfect Environment Minor irritations, like an uncomfortable chair or a dim light which forces you to strain your eyes, can contribute to a lack of desire to work. Ensure that your working environment is comfortable and calming so that you can focus on your work. Know Your Optimal Working Routine Something which can dramatically reduce procrastination and improve efficiency is working out an optimized working routine. For example, different people work better at different times of day; night owls might get their best work done at midnight, while early birds might have 2,000 words done before 9am! Work to your strengths, but make sure your sleeping pattern is not affected. What Motivates You? Sometimes, small rewards can increase motivation and having something tangible to look forward to can spur you on to meet your goals. Knowing you have dinner plans with friends will encourage you to meet your targets for the day.

Interesting topic would get your readers to know what your main point Essay

Interesting topic would get your readers to know what your main point - Essay Example In The Geography of Bliss, Weiner travels from east to west including India, Thailand, Netherlands, Switzerland, Bhutan, and Moldova among other countries to investigate their idea of happiness. Among the countries he visits, the Swiss have an interesting view of happiness. Democracy, moderation, and the absence of envy are the factors that drive happiness in this country. While investigating happiness according to the Swiss, Weiner’s expresses his impression of the place concerning their behavioral habits and lifestyle. The author personally relates his experiences and investigations in the narrative. In chapter two of the book, Weiner looks at the Swiss source of happiness. While on safari with his girlfriend, he comes across a Swiss couple and their perfectionist tendencies. The writer takes his time to go to Geneva and learn a little more about the Swiss. The first thing that strikes him is how clean the streets are and how sober and controlled the Swiss are. Accordingly, he questions their lifestyle, habits, and general behavior, as well as wonders what makes the Swiss tick. Secondly, Weiner asks why the Swiss are so humorless and serious all the time. Further, the author questions how they could be so disciplined and focused. Additionally, Weiner wonders if a link could exist between the Swiss lifestyle and habits, and the high suicidal rates. Moreover, he tries to understand why the Swiss do not find it appropriate to talk about money. Given these revelations, he inquires where the Swiss get their happiness. Consequently, Weiner alludes that they could probably get happines s from not generating envy in others. Notably, there is little or no privacy in Switzerland, and everyone knows their neighbor’s business. Hence, it is hard to understand how they find privacy because such a lifestyle is hard to handle. The Swiss have one activity that helps them unwind. Skiing is a sporting activity that they love. According to Weiner, they usually take time off

The System Of Finance For Local Government Essay

The System Of Finance For Local Government - Essay Example The model was primarily concerned with finding a market-like mechanism that would achieve an efficient allocation of resources to the public sector. The main finding included the fact that inter-jurisdictional competition is a vital element of the mechanism. The key players in Tiebout’s model are individual citizens and governments. business firms are not an explicit part of the model (Brueckner 2004, p 138). It was meant to be applied to local governments and to a lesser degree, to state governments. The model assumes citizens have full knowledge of government revenue and expenditure packages, that there are a large number of communities among which individuals can choose to live, and that people will opt for the community that best satisfies their preferences. Moreover, the model assumes that government services exhibit no spillover effects (Billings 2008, p 45). Tiebout’s model made three additional assumptions; one, that jobs impose no locational constraint on indiv iduals; two, that a community’s optimal size, meaning the size for which the average cost of producing a particular packages of public services is minimized, can be determined; and three, that each community seeks to attain its optimal size (Feiock 2004, p. 76). The model envisions citizens sorting themselves out among available communities so that demands for government services within any particular community would become homogenous. In theory, Tiebout concluded that to the extent these rather restrictive assumptions are met, good and services provided by the local public sector will exhibit both allocative efficiency (the right amounts of the various good and services are produced ) and productive efficiency (they are produced at least cost) (Rivkin 2001, p. 206). In Tiebout’s model, community taxes would be benefit taxes, or proportional to the benefits citizens receive form public services, rather than taxes based on the ability to pay.