Different Types Of Sharks Essays - Carcharhinidae, Sharks

Different Types Of Sharks INTRODUCTION Although sharks belong to the class Chondrichtyes, there are many different types. Sharks arose about 350 million years ago and have remained virtually unchanged for the past 70 million years and still comprise a dominant group. It is thought that sharks almost certainly evolved from placoderms, a group of primitive jawed fishes. It took a long series of successful and unsuccessful mutations with fin, jaw positions etc to give us all the different designs of sharks around today. When asked to draw a shark, most people would draw a shape along the lines of the whaler shark family, tigers or a mackeral shark such as a porbeagle. However many people do not realize the sheer diversity in the shape of sharks, or that rays are really sharks. Seldom does such an animal inspire such a variety of emotions reflecting a mixture of fascination, awe and fear. Sharks have occasionally exacted a terrible price from humans who have trespassed on their territory. No better understood than the ocean that they inhabit, these creatures should be regarded in the same way as lions, tigers, and bears: as dangerous, predatory but nonetheless magnificent animals. Different Types of Sharks Living sharks are divided into eight major orders, each easily recognizable by certain external characteristics. Each order contains one or more smaller groups, or families. In all there are 30 families of sharks and they contain the 350 or more different kinds or species of sharks. The eight major orders of sharks include the Squantiformes, Pristiophormes, Squaliformes, Hexanchiformes, Carcharhiniformes, Lamniformes, Orectolobiformes, and the Heterodotiformes. The orders have distinguishing characteristics that fit in each. The Squantiformes normally have flat bodies that are ray-like with mottled dorsal surfaces. These sharks have a short terminal mouth, which is armed with small impaling teeth. They also have a caudal fin, which has a lower lobe that is longer than the upper lobe. Their pectoral fins extend forward over the ventrally directed gills. The Pristiophormes have more of an elongated snout, which is saw-like and edged with slender, needle-sharp lateral teeth. They have two dorsal fins and no anal fin. They use short transverse mouths and small cuspidate holding teeth in both jaws. Squaliformes have no anal fin as well, but their snout is not elongated, but is somewhat long. Many have powerful cutting teeth in both jaws. In some species these razor sharp teeth are in the lower jaw only and the upper teeth serve to hold the food. Hexanchiformes have six or seven gill slits. They are sharks with a single spineless dorsal fin, and an anal fin. The typical Carcharhiniforme has an elongated snout, a long mouth that reaches behind the eyes, an anal fin and two spineless dorsal fins. The eyes have movable, nictitating lower eyelids worked by unique muscles. Teeth vary from small and cuspidate or flattened to large and bladelike. Carcharhiniformes have no enlarged rear crushing teeth. Along with this they have a spiral scroll intestinal valve. A Lamniforme shark has an elongated snout. Most have long mouths that reach behind the eyes, an anal fin and two spineless dorsal fins. They also have a ring intestinal valve. The Orectolobiformes have pig-like snouts and short mouths that in most species are connected to the nostrils by grooves. There is an anal fin but no fin spines on the two dorsal fins. They have uniquely formed barbells at the inside edges of the nostrils. Heterodotiformes are the only living shark that combines fin spines on their two dorsal fins and anal fin. They only have five-gill slits. In each order there are specific types of sharks. Each shark belongs to a family with different species. The Angel shark (Squantiforme) is just one of the many. It has a single family of about thirteen species. They are all ovoviviparous livebearers and most do not exceed 1.5 meters. Saw sharks (Pristiophoriformes) are harmless bottom sharks. They are also a single family but with five species. They are also ovoviviparous livebearers. Four sharks that belong to the order Sqauliforme are the Bramble, Dogfish, and Rough sharks. They have three families with eighty-two species. They too, are ovoviviparous livebearers. They have more cylindrical bodies. Frilled sharks, Six, and Seven gill sharks (Hexanchiformes) have two

Incarcertion of Pregnant women essays

Incarcertion of Pregnant women essays SHOULD INCARCERTION OF PREGNANT WOMEN BE AVOIDED? The subject of incarceration of pregnant women has been a very controversial issue for years. In this debate, Ken Ayers argues YES. He is well qualified to take this stand because he has presented and published a number of works on this particular issue. He believes that pregnant women who are found guilty of committing crimes should be given special consideration. He explained the fact that there are inadequate medical facilities in prison to cater to the needs of pregnant women. He stresses that while he is not saying that pregnancy should be a major factor to be considered during pregnancy, it is a factor that should be put into consideration. Pregnant women in jail have the dilemma of having to deal with the stress of being pregnant and the stress of being in jail at the same time. Statistics show that women inmates tend to be young, single, uneducated, and incarcerated for drug- alcohol offenses, and other non-violent crimes (pp91). He goes on to state that women who are in jail when they are pregnant are classic high-risk pregnancies (pp91). The reason he gives for this is the fact that inmates usually have had a previous lifestyle that was dangerous to their unborn child. The Health and Medical Care in the prison system is very inadequate and the inmates usually cannot complain even though the Eighth Amendment is on their side. Pregnant women need good and consistent care to make sure that they carry the baby to term and have a smooth delivery. Prenatal Care is also necessary to monitor the babys growth and development. Ayers suggests that incarceration of pregnant women would be an adequate choice if the health care is adequate but he further argues that the child, when born, will suffer a great deal because he or she has not bonded with his or her mother. Laura Moriarty argues NO. She is also a very...

County analysis Essay Example | Topics and Well Written Essays - 2750 words

County analysis - Essay Example In carrying out business with parties from elevated power distance countries, the managers used or should have title at least on the same level as those they are negotiating with. On the other hand, cultures that have low power distance should have the inequalities reduced. Japan is ranked at 54 while the United States of America is ranked at 45. According to Hofstede, countries with low uncertainty avoidance index score have innovative approaches and risk investment tendencies. This are attributes found in entrepreneurs. Uncertainty avoidance is the reality that vagueness about the prospects of the future is a basic fact of human life with which we try to cope through the domain of technology, law and religion. Uncertainty avoidance is also the extent to which individuals feel endangered by situations. This leads to people creating institutions that deal with these. Hofstede used stress, employment stability and rule orientation to identify. Countries are then ranked as low or high concerning uncertainty avoidance. Squat uncertainty avoidance means that, there is a strong willingness to take a risk. On the other hand, high uncertainty implies a lower willingness to take risk. Hofstedes notes that, in societies where there is high uncertain avoidance, there tends to be a generational gap amid the old and the young. High unce rtain avoidance cultures are concerned with rituals and traditions and often follow exceedingly complex rules and regulations. Individualism refers to preference of closed surrounding environment, in which it is understood that, one must mind for themselves and their close relations as opposed to the entire cluster in which one is an associate. Individualism can be referred to as an appraisal of the emotional dependence and autonomy of a person. The culture of a country is scored high in this sense if there are favourable responses to items such as , having a satisfying job which leaves you with enough time for yourself and the family. In

Starting Up a Business That Involves The Supply of Green And Organic Assignment

Starting Up a Business That Involves The Supply of Green And Organic Groceries - Assignment Example The researcher states that he wants to start his business of natural and organic grocery delivery service which will mainly focus on the supply of fruits and vegetables because of the recent interest in fresh and green farm produce. The society is increasingly becoming aware of the need for environmentally friendly production of food and disposal of food waste. In addition, recent health concerns about junk food and unhealthy eating mean that there will be a special interest in green groceries. The business will fill the need of environmental and health conscious individuals who prefer greengroceries over genetically modified or junk food. In addition, there is a food shortage in some regions, and the never-ending need to eat means that there will always be a constant demand for food. A lesson from Bakers Edge and Shark Tank is that networking is essential in any business. The Shark Tank investors largely focus on networking as integral to the success of any business. A network is a structure that attracts and informs potential customers of the existence of a business. The network involves such things as aggressive marketing and endorsements from celebrity personalities. In addition, it is essential to identify potential investors and their networks. Bakers Edge interview on the Shark Tank show gave them considerable exposure and mileage in the bakery business. Oprah also hosted and endorsed their product.

Health Care Utilization Assignment Example | Topics and Well Written Essays - 1000 words

Health Care Utilization - Assignment Example Majorly, healthcare reforms have expanded access and made many people access affordable healthcare and health insurance (Gulliford & Morgan, 2013). Surveys from experts charged with seeking people’s opinions as to whether reforms have made access of healthcare easier suggest that most people agree that health reforms have been successful. For instance, they cite novel healthcare laws, and new healthcare insurance measures as some of the significant gains. After about a year of endless debates, meetings and workshops, speeches and votes, the New York Times (April 5, 2010) reported that Congress passed into law major health reform laws (Gulliford & Morgan, 2013). 89 % of healthcare leaders as well as health policy makers believe the novel reform laws will expand access to healthcare and make health insurance affordable to a significant number of Americans. Many opinion leaders support the recent Modern Health Care Opinion/Commonwealth Fund. This can only mean that healthcare reforms have been immensely successful (Gulliford & Morgan, 2013). What is more, opinion leaders support numerous healthcare policy legislation aimed at reducing the bottlenecks affecting efficient delivery of healthcare services. Subsidies advocated for through the health reforms allow many people to access healthcare and insurance cover. Concisely, the reforms improved service delivery. The New York Times reports that 90% of the population can access cheap insurance cover; 88% give priority for healthcare reforms; 80% support innovation, which makes access to a patient’s background information easier. Healthcare providers and Medicare enhancers are more accountable (Gulliford & Morgan, 2013). Changes in utilization of healthcare mean that the United States now joins other industrialized countries with efficient healthcare systems that make access to health care essential. The new laws brought about

Literature Review On Soil Erosion

Literature Review On Soil Erosion The Latin word erodere, (meaning to gnaw away) is the origin of the word erosion (Roose, 1996). Soil Erosion is the physical removal of topsoil by various agents, including falling raindrops, water flowing over the soil profile and gravitational pull (Lal 1990). The Soil Science Society of America defines erosion as the wearing away of the land surface by running water, wind, ice or other geological agents, including such processes as gravitational creep (SCSA, 1982). Physical erosion involves the detachment and transportation of insoluble soil particles (sand, silt and organic matter). Removal of soluble material as dissolved substances is called chemical erosion and this maybe caused by surface runoff or subsurface flow where the water moves from one layer to another within the soil profile (Lal 1990). According to ASCE, 1975, the physical processes in soil erosion include detachment of soil particles, their transportation and subsequent deposition of soil sediments downslope by raindrop impact and runoff over the soil surface. Rainfall is the most important detaching agent (Morgan and Davidson 1986; Lal, 1990) followed by overland flow in entraining soil particles (Lal 1990). The process of soil erosion occurs in three main steps, detachment of soil particles, transportation and deposition of soil particles downslope by raindrop impact and runoff over the soil surface (ASCE 1975; Morgan and Davidson, 1986, Lal 1990) followed by overland flow in entraining soil particles (Lal, 1990). Soil erosion reduces soil productivity by physical loss of topsoil, reduction in rooting depth and loss of water. In contrast soil, soil depletion means loss or decline of soil fertility due to crop removal or removal of nutrients by eluviations from water passing through the soil profile (Lal, 1990). Sedimentation however, causes off site effects like degradation of basins, accumulation of silts in water reservoirs and burial of low-lying productive areas and other problems (Lal, 1990). Sediments is the main cause of pollution and eutrophication (Lal, 1990). According to Lal 1990, soil degradation may be caused by accelerated soil erosion, depletion through intensive land use , deterioration in soil structure, changes in soil pH, leaching, salt accumulation, build up of toxic elelments such as aluminum or zinc, excessive inundation leading to reduced soil conditions and poor aeration. Soil Erosion is the most serious and least reversible form of land degradation (Lal, 1977; El-Swaify, Dangler and Amstrong, 1982). Soil erosion and soil loss , according to Lal (1990) have adverse effects on agriculture because they deplete the soils productivity and diminish the resourse base. 2.2 Soil Erosion Process Geologic erosion can be caused by a number of natural agents including rainfall, flowing water and ice, wind and the the mass movement of soil bodies under the action of gravity which cause the loosened or dissolved earthy and rock materials to be removed from a place and eventually deposited to a new location (Lal,1990; Morgan and Davidson, 1986). The Soil Science Society of America (SCSA, 1982) described geologic erosion as the normal or natural erosion caused by geologic processes acting over long periods and resulting in the wearing away of mountains, the building up of flood plains, coastal plains. Etc. The slow and constructive natural soil erosion process has been significantly accelerated by human activities of poor farming practices, overgrazing, ground clearing for construction, logging and mining (Lo, 1990). Accelerated erosion not only affects the soil but also the environment and is the primary cause of soil degradation (Lal, 1990). Agriculture has been identified as th e primary cause of accelerated soil erosion (Pimentel, 1976). 2.3 Soil Characteristics in the Tropics Extremes of climate and wide variety of parent materials cause great contrast of soil properties in the tropics from soils in other temperate regions. In the tropics soils are highly variable and diverse like the vegetation (Sanchez and Buoi, 1975; Van Wambeke, 1992). The main soil types are alfisols, oxisols, ultisols and inceptisols (El-Swaify, 1990). Tropical soils low in weatherable minerals and basic cations (sodium, calcium, magnesium, and potassium) resulted from continuous weathering of parent materials (Lo, 1990). The ability of these soils to keep plant nutrients is largely dependent on the humus content found in plant biomass and the organic matter (Rose,1993). The inactivity of soil mineral constituents (kaolin and sesquioxides) in these soils, causes deficiency in crop nutrients, lowers the capacity to retain basic cations, limits active relationship with organic matter and excessively immobilizes phosphates and related anions, a condition which are highly toxic to plant roots (Lo, 1990). Crop production in tropical soils are constrained by primarily aluminum- derived soil acidity and infertility but generally their physical properties are favourable (El-Swaify, 1990). Tropic soils have moderate to high permeability under natural conditions, but susceptible to slaking and development of impermeable crust upon action of raindrops and as a result runoff increases with continuous cultivation (Lal, 1982). This crusting cause insignificant reduction of filtration rate, increasing water runoff which leads to acceleration of soil erosion (Falayl and Lal, 1979). It is important to note however that heavy and intense rains cause severe erosion in the tropics (Morgan, 1974; Wilkinson 1975; Amezquita and Forsythe, 1975; Lal 1976; Aina, Lal and Taylor, 1977; Bois, 1978; Sheng 1982). 2.4 Soil Erosion on Steep Slope According to Lal 1990, Steeplands refer to lands with a slope gradient greater than 20%. It is important to note however that flat undulating lands have a great potential for crop production and agricultural development. Due to the possibility of soil erosion and the problem of mechanization, the steep areas are considered marginal for agriculture production (Lal, 1990). The difficult topography in steepland agriculture restricts mechanizations of operations thus, reducing all agricultural activities (land preparation, cultivation and harvesting), limiting the farmer in scale and efficiency. Inputs such as fertilizer and pesticides have to be carried manually by the farmer. As a resulted they are used scarcely. Observably any increase in the use of these agricultural inputs will result in decline in he farmers profits from the generally lower agricultural field (Benvenuti, 1988). For all these reasons steepland farmers tend to concentrate in high value crop production of limited scale (Ahmad, 1987; Ahmad 1990). It is important to note however that farmers prefer steepslopes due to cultural hand cultivation, planting and harvesting can be done in an upright fashion (Williams and Walter, 1988). Futher more subsistence farmers are found on steep slopes because of more favourable environmental conditions such as lower temperatures, reduced diseases and h igher reliability of rainfall. (Hurni, 1988). In the tropics, removal of forest vegetation causes excessive leaching and accelerated soil nutrient loss. Being highly weathered soil types , their contained minerals generally have poor ability to retain sorbed nutrients against leaching. Clay soils with high residualmiron contents are considered superior in resistance to runoff caused soil erosion; thus, soils emanated from basic igneous rocks and red soils developed from calcareous rocks are strongly aggregated due to the cementing property of iron oxides, hence, soil erosion is expected to be less than for most other soils. Also soils developed from fragmentary volcanic materials with andic properties are resistant to soil erosion (Sheng, 1986; Ahmad, 1987; Ahmad, 1990; Lal, 1990). Soils formed from shales, schists, phyillites and sandstones are considered highly erodible. Soils produced from these rocks are high in both sand or silt fraction, and clay minerals and iron oxides are generally insufficient as cementing agents for a stable-structured soil. These parent materials are generally rich in muscovite occurring in all soil particle-size fractions. Micah-rich soils are weak-structured, and thus raindrops can easily dislodged the weak aggregates, while the clay fraction dispersed in water. The resulting mica flakes settling on their flat axes in the water film on the soil surface causes soil crusting. The formation of soil crusts further restricts water entry into the soil (Ahmad and Robin, 1971; Sumner, 1995), resulting to disposal of a much greater volume of runoff water, a condition which leads to further disintegration of soil aggregates and transport of colloidal soil material (Ahmad, 1987; Ahmad 1990). Soil crust restricts gaseous exchange leading to anaerobic soil conditions, denitrification, toxic effects due to ethylene production, and mechanical impedance to seedling emergence (Ahmad 1987; Ahmad, 1990). Steep slope cultivation can cause certain instability in the ecological system with both onsite and offsite detrimental impacts (El-Swaify, Garnier and Lo, 1987). Soil, climate, land use and farming systems affect the extent and the degree of severity of soil erosion. However, regardless of soil and climatic conditions, intensively used steeplands in densely populated regions experience severe soil erosion problem. Land use influences the degree of severity of soil erosion on steeplands. Uncontrollable grazing or over grazing, exensive and abusive cultivation, diversified cropping are responsible for severe soil erosion in unprotected arable lands (Roose, 1988; Liao et al 1988). Ahmad (1987;1990) reportd soil loss of approximately 120 t0 180 tonnes per hectare in Tobago Trinidad. In Australia, annual soil loss of 200 t/ha to 328 t/ha has ben reported from sloping sugar cane plantations in central and north Queensland (Sallaway, 1979; Mathews and Makepeace 1981). There are two types of soil erosion associated with the Caribbean region, land slipping and gullying. Land slipping is a manifestation of mass movement associated with steepland agriculture and the severity being strongly influenced by the parent materials. Land clearing (example deforestation) and crop production can influence land slipping particularly in the early portion of the wet season when the cleared soil wets faster due to saturation of the soil above rock. Serious dislocations, crop loss and destruction of any mechanical anti erosion devices can result from this form of mass movements. Due to drastic changes in hydrological conditions experienced by land naturally prone already to slipping and cleared for agriculture for the first time land slippage would be of common experience (Ahmad 1987; Ahmad 1990). Gullying is another common form of soil erosion that occurs on steep land bcause of the terrain involved. This is more common on sandy soils, volcanic soils and vertisols, which are all porous materials. Soils easily attain saturated conditions upon the rapid entry of water, consequently breaking the material and ultimately, leading to the formation of gullies. Agricultural activities enables this soil erosion in steeplands by allowing rapid soil wetting upon the start of the wet season. Farming activities though unsuitably oriented field boundaries, foot tracks and the lack of provision for disposal of surface water are some main causes of gullying, even on soils not prone to this tpe of steepland soil erosion (Ahmad 1987;Ahmad 1990). Since steeplands are traditionally considered marginal for agricultural crop production, most research on soil erosion and soil conservation has been done on either flat land or rolling land with a maximum slope of about 20%'(Lal, 1988). 2.5 Factors Affecting Soil Erosion The causes of soil erosion have been intensively discussed during the past 40 years. Soil erosion is a natural process that is enhanced by human activity (Richter, 1998) and occurs in all landscapes and under different land uses. In addition to human activities, soil erosion processes are also caused by morphometric characteristics of the land surface, the erosive forces of rainfall and the erodibility of soils and soil surfaces. When rainwater reaches the soil surface it will either enter the soil or run off. Runoff occurs when the rainfall intensity exceeds the infiltration capacity of the soil. Water erosion is the result of the dispersion action of rain drops, the transporting power of water and also the vulnerability of the soil to dispersion and movement (Baver and Gardner, 1972). The effects of soil erosion is also classified: definition of gullies and explanation of gully development is given by Morgan (1996), as well as Hudson (1995) who additionally focuses on individual cases of the development of gullies. Toy et al (2002) give detailed definitions of soil erosion features and processes such as sheet erosion and inter-rill erosion, rill erosion, as well as ephemeral and permanent gully erosion. Rill erodibility depends both directly and indirectly on soil properties such as bulk density, organic carbon and clay content, clay mineralogy, cations in the exchange complex, soil pH and experimental conditions such as moisture content, aging of prewetted soil and quality of eroding water (Rapp,1998). Govers (1990) found that runoff erosion resisitance of a loamy material was extremely sensitive to variation in the initial moisture content and to a lesser extent to changes in bulk density. The process of water erosion can be separated into two components, rill and interrill erosion (Young and Onstad, 1978). Interrill erosion (sheet erosion) is mainly caused by raindrop impact and removes soil in a thin almost imperceptible layer (Foster, 1989). In interril erosion the flow of water is generally unconfined, except between soil clods and covers much of the soil surface. As the velocity of flow increases the water incises into the soil and rills forms (Evans,1980). Rill erosion begins when the eroding capacity of the flow at some point exceeds the ability of the soil particles to resistant detachment by flow (Meyer cited by Rapp, 1998). Soil is detached by headcut advance from knickpoints (De Ploey, 1989; Bryan, 1990), rill slide sloughing and hydraulic shear stress (Foster cited by Rapp, 1998) as well as by slumping by undercutting of side walls and scour hole formation (Van Liew and Saxton, 1983). These processes are usually combined into a detachment prediction equation as a function of average shear stress (Foster cited by Rapp, 1998). When the rills develop in the landscape, a three to five fold increase in the soil loss commonly occurs (Moss, Green and Hutka 1982 and Meyer and Harmon 1984). 2.5.1 Vegetative Factors The effects of vegetation can be classified into three catergories: The interception of raindrops by the canopy (DHuyvetter, 1985). Two effects are associated with this. Firstly, part of the intercepted water will evaporate from the leaves and stems and thus reduce runoff. Secondly, when raindrops strike the vegetation, the energy of the drops is dissipated and there is no direct impact on the soil surface. The interception percentage depends on the type of crop, the growth stage and the number of plants per unit area. A well distributed, close growing surface vegetative cover will slow down the rate at which water flows down the slope and will also reduce concentration of water (DHuyvetter, 1985). As a result, it will decrease the erosive action of running water. There is also the effect of roots and biological activity on the formation of stable aggregrates, which results in a stable soil structure and increased infiltration that reduces runoff and decreases erosion (DHuyvetter, 1985). Increased permeability also reduces erosion as a result of in increased water percolation due to better drainage. Stables aggregrates in the topsoil also counteract crusting. 2.5.2 Rainfall Factors Raindrop size, shape, duration of a storm and wind speed interactions controls the erosive power of rainfall (DHuyvetter, 1985). The erosivity of rainfall is expressed in terms of kinetic energy and is affected by various factors. According to Wischmeier and Smith (1965), the intensity of rainfall is closely related tot e kinetic energy, according to the regression equation E = 1.213 + 0.890 log I Where E = the kinetic energy (kg.m/m2.mm) I = rainfall intensity (mm/h) Raindrop size, distribution and shape all influence the energy momentum of a rainstorm. Laws and Parson (1943) reported an increase in median drop size with increase in rain intensity. The relationship between mean drop size (D50) and rainfall is given by: D50:2.23 I 0.182 (inch per hour). The median size of rain drops increases with low and medium intensity fall, but declines slightly for high intensity rainfall (Gerrard, 1981). The kinetic energy of an rainfall event is also related to the velocity of the raindrops at the time of impact with the soil (DHuyvetter, 1985). The distance through which the rain drop must fall to maintain terminal velocity is a function of drop size. The kinetic energy of a rainstorm is related to the terminal velocity according to the equation: Ek = IV2/2 Where Ek = energy of the rain storm I = Intensity V= Velocity of raindrop before impact Ellison (1945) developed an equation showing that the relationship between the soil detached, terminal velocity, drop diameter and rainfall intensity: E = KV4.33 d1.07 I0.63 Where E = relative amount of soil detached K = soil constant V = velocity of raindrops (ft/sec) d = diameter of raindrops (mm) I = rainfall intensity 2.5.2.1 Effect of rainfall intensity on runoff and soil loss According to Morgan (1995), soil loss is closely related to rainfall partly through the detaching power of raindrops striking the soil surface and the contribution of rain to runoff. If rainfall intensity is less than the infiltration capacity of the soil, no surface runoff occurs and the infiltration rate would equal the rainfall intensity (Horton, 1945) as sited by Morgan (1995). If the rainfall intensity exceeds the infiltration capacity, the infiltration rate equals the infiltration capacity and the excess rainfall forms surface runoff. According to Morgan (1995), when the soil is unsaturated, the soil matric potential is negative and water is held in the capillaries due to matrics suction. For this reason, under saturated conditions sands may produce runoff very quickly although their infiltration capacity is not exceeded by the rainfall intensity. Intensity partially controls hydraulic conductivity, increasing the rainfall intensity may cause conductivity to rise so that although runoff may have formed rapidly at relatively low rainfall intensity, higher rainfall intensities do not always produce greater runoff (Morgan, 1995). This mechanism explains the reason why infiltration rates sometimes increase with rainfall intensities (Nassif and Wilson, 1975). 2.5.3 Soil Factors According to Baver et al, (1972), the effect of soil properties on water erosion can be in two ways : Firstly, certain properties determine the rate at which rainfall enters the soil. Secondly, some properties affect the resistance of the soil against dispersion and erosion during rainfall and runoff. The particle size distribution is an important soil property with regards to erodibility. Generally it is found that erodible soils have a low clay content (DHuyvetter, 1985). Soils with more than 35% clay are often regarded as being cohesive and having stable aggregates which are resistant to dispersion by raindrops (Evans, 1980). Evans also stated that sands and coarse loamy sands are not easily eroded by water due to its high infiltration rate. In contrast soils with a high silt or fine sand fraction are very erodible. Erodibility of soil increases with the proportion of aggregates less than 0.5mm (Bryan, 1974). Factors which contribute to aggregate stability include organic matter content, root secretions, mucilaginous gels formed by break down of organic matter, the binding of particles by sesquioxides and the presence of a high Ca concentration on the exchange sites of the colloids instead of a high sodium content (DHuyvetter, 1985). The depth of erosion is determined by the soil profile (Evans, 1980). According to Evans soil horizons below the A horizon or plough layer are often more compact and less erodible. The texture and chemical composition of the sub surface horizon can also have an adverse effect. Normally deep gullies can be cut if the parent material is unconsolidated. If resistant bedrock is near the surface only rills will develop. Soil rich in surface stones are less susceptible to erosion (Lamb, 1950 and Evans, 1980). Stones protect the soil against erosion and also increase the infiltration of the flowing water into the soil. The antecedent soil moisture and the surface roughness are both regarded by Evans (1980) as important soil factors affecting erosion. The ability of a soil to accept rainfall depends on the moisture content at the time of the rainfall event. 2.5.3.1 Factors affecting aggregate stability Soil structure is determined by the shape and size distribution of aggregates. Aggregrate size and strengthe determine the physical properties of a soil and its susceptibility to breakdown due to water forces. Their stability will have a decisive effect on soil physical properties (Lynch and Bragg, 1985). The main binding materials giving stable aggregates in air dry state are the glueing agents in organic matter (Chaney and Swift, 1984; Tisdale and Oades, 1982) and sesquioxides (Goldberg and Glaubic, 1987). 2.5.3.1.1 Aluminium and Iron Oxides The soil used by Kemper and Koch (1966) contained relatively little free iron, although it did contribute to aggregrate stability. Their data show a sharp increase of free iron from 1 to 3%. Goldberg and Glaubic (1987) concluded that Al-oxides were more effective than Fe-oxides in stabilizing soil structure. Al-oxides have a greater proportion of sub-micrometer size particles in a sheet form as opposed to the spherical form of Fe-particles. Shainberg, Singer and Janitzky (1987) compared the effect of aluminium and iron oxides on the hydraulic conductivity of a sandy soil. 2.5.3.1.2 Organic Matter Organic matter can bind soil particles together into stable soil aggregates. The stabilizing effect of organic matter is well documented. Little detailed information is available on the organic matter content required to sufficiently strengthen aggregates with ESP values greater than 5 or 7, and containing illite or montmorrillionite, so as to prevent their dispersion in water (Smith, 1990). High humus content makes the soil less susceptible to the unfavourable influence of sodium (Van den Berg, De Boer, Van der Malen, Verhoeven, Westerhof and Zuur, 1953). Kemper and Koch (1966) also found that aggregate stability increased with an increase in the organic matter content of soils. A maximum increase of aggregate stability was found with up to 2% organic matter, after which aggregate stability increased very little with further increases in organic matter content. 2.5.3 Slope Factors Slope characteristics are important in determining the amount of runoff and erosion ( DHuyvetter, 1985). As slope gradient increases, runoff and erosion usually increases (Stern, 1990). At low slopes due to the low overland flow velocities, detachment of soil particles from the soil surface into the water layer is due to detachment alone (Stern, 1990). Additionally, at low slope gradients, particles are splashed into the air in random directions unlike the case with steeply sloping land where down slope splash occurs (Watson and Laflen, 1985). As slope gradient increases, the ability for surface runoff to entrain and transport sediments increases rapidly until the entrainment by the surface runoff becomes dominant contributing to sediment transport (Stern, 1990). Foster , Meyer and Onstad (1976) presented a conceptual model that showed that at lower slopes, interill transport determined erosion, while at steeper slopes, raindrop detachment determined it. Th uniform bed characteristics of sheet flow transport tend to be replaced by channels because of instability and turbulent flow effects (Moss, Green and Hutka, 1982). There are many empirical relationships relating soil transport by surface wash to slope length and slope gradient. Zingg (1940) showed that erosion varied according to the equation: S = X1.6 tanB1.4 Where S = soil transport cm/yr X = slope length (m) B = slope gradient (%) Studies conducted by Gerrard (1981), showed that plane and convex slopes did not differ significantly in the amount of soil lost by surface runoff, but concave slopes were less eroded. Some researchers such as Zingg (1940) and Mc Cool et al (1987) indicated that soil erosion increases exponentially with increase in slope gradient. The relationship is indicated after Zing (1940) by: E = aSb where E is the soil erosion, S is the slope gradient (%) and a and b are empirical constants. The value of b ranges from 1.35 to 2.0. The other relationship between erosion and slope gradient for inter-rill erosion is given by Mc Cool et al (1987) E = a sin b Q+C Q is the slope angle in degrees A,b and C are empirical constants. However, even if the effect of slope gradient on erosion is well recognized, several studies indicate that the power relationship between slope gradient and soil loss over predicts interrill erosion rate by as much as two or more times (Torri, 1996;Fox and Bryan, 1999), and the relationship is better described as linear. 2.8 Soil Erosion Impacts 2.8.1 Soil Physical Properties Progressive soil erosion increases the magnitude of soil related constraints for crop production. These constraints can be physical, chemical and biological. The important physical constraints caused by erosion are reduced rooting depth, loss of soil water storing capacity (Schertz et al 1984; Sertsu, 2000), crusting and soil compaction and hardening of plinthite (Lal, 1988). Erosion also results in the loss of clay colloids due to preferential removal of fine particles from the soil surface (Fullen and Brandsma, 1995). The loss of clay influences soil tilth and consistency. Exposed subsoil is often of massive structure and harder consistency than the aggregated surface soil (Lal, 1988). Development of rills and gullies may change the micro-relief that may make use of farming machinery difficult. Another effect of erosion is that the manangement and timing of farm operations. 2.8.2 Soil Chemical Properties Soil erosion reduces the fertility status of soils (Morgan, 1986; Williams et al., 1990). Soil chemical constraints and nutritional problems related to soil erosion include low CEC, low plant nutrients (NPK) and trace elements (Lal, 1988; Fullen and Brandsma, 1995). Massy et al (1953) reported an average loss of 192 kg of organic matter, 10.6 kg of N and 1.8kg per ha on a Winsconsin soils with 11% slope. Sharpley and Smith (1990) reported that the mean annual loss of total P in runoff from P fertilized watersheds is equivalent to an average of 15%, 12% and 32% of the annual fertilizer P applied to wheat, mixed crop grass and peanut sorghum rotation practices respectively. Researchers (Massy et al 1953; Lal, 1975) have also reported extensive loss of N in eroded sediments. 2.8.3 Productivity Quantifying the effects on crop yields is a difficult task. It involves the evaluation of interactions between soil properties, crop characteristics and climate. The effects are also cumulative and not observed until long after accelerated erosion begins. The degree of soil erosions effects on crop yield depends on soil profile characteristics and management systems. It is difficult to establish a direct relationship between rates of soil erosion and erosion induced soil degradation on the one hand and crop yield on the other (Lal, 1988). It is well known that soil erosion can reduce crop yields through loss of nutrients, structural degradation and reduce of depth and water holding capacity (Timilin et al, 1986; Lal,1988). Loss of production in eroded soil further degrades its productivity which in turn accelerates soil erosion. The cumulative effect observed over a long period of time may lead to irreversible loss of productivity in shallow soils with hardened plinthite or in soils that respond to expensive management and additional inputs (Lal,1988). 2.8.4 Off Site Effects of Soil Erosion. Effects of erosion include siltation of rivers, crop failure at low lying areas due to flooding, pollution of waterbodies due to the various chemicals brought by the runoff from different areas. Several studies reported the significance of the off site effects of soil erosion on land degradation (eg. Wall and ven Den,1987; Lo, 1990; Robertson and Colletti, 1994; Petkovic et al, 1999) Rainwater washes away materials that originate from fertilizers and various biocides (fungicides, insecticides, herbicides and pesticides) which are applied in large concentrations. They reappear in greatr quantities in the hydrosphere polluting and contaminating the water environment (Zachar,1982;Withers, and Lord, 2002; Verstraeten and Poesen, 2002). Chemical pollution of water mainly by organic matter from farm fields causes rapid eutrophication in waterways (Zachar, 1982;Zakova et al, 1993; Lijklema, 1995). 2.8.5 Soil Erosion Models Modelling soil erosion is the process of mathematically describing soil particle detachment, transport and deposition on land surfaces (Nearing et al, 1994). Erosion models are used as predictive tools for assessing soil loss and project planning. They can also be used for understanding erosion processes and their impacts (Nearing et al 1994). There are three main types of models, empirical or statistical models, conceptual models and physically based models (Morgan 1995, Nearing et al 1994, Merritt et al 2003). It is important to note however that there is no sharp difference among them. 2.8.5.1 Physically Based Models These models are based on solving fundamental physical equations describing stream flow and sediment and associated nutrient generations in a specific catchment (Merritt et al ., 2003). They are developed to predict the spatial distribution of runoff and sediment over land surfaces during individual storms in addition to total runoff and soil loss (Morgan, 1995). Physically based models are also called process based models (Morgan, 1995) as they rely on empirical equations to determine erosion processes. These models use a particular differential equation known as the continuity equation which is a statement of conservation of matter as it moves through space over time. The common physically based models used in water quality studies and erosion include : The Areal Non-Point Source Watershed Environment Response Simulation (ANSWERS) (Beasley et al., 1980), Chemical Runoff and Erosion from Agricultural Management Systems (CREAMS) (Knisel, 1980), Griffith University Erosion System Temp late (GUEST) (Misra and Rose, 1996), European Soil Erosion Model (EUROSEM) (Morgan, 1998), Productivity, Erosion and Runoff, Functions to Evaluate Conservation Techniques (PERFECT) (Littleboy et al., 1992) and Water Erosion Prediction Project (WEPP) (Laflen et al., 1991). 2.8.5.2 Empirical M

War and Peace and Tolstoys View of History Essay -- Tolstoy War and P

War and Peace and Tolstoy's View of History      Ã‚  Ã‚   Count Lev Tolstoy wrote abundantly on the philosophical issues that he felt were universally important.   One of the most prolific examples of this is his view of history.   This is set out most clearly and most famously in his largest work, War and Peace.   As Tolstoy claimed himself in a public statement on the work, 'War and Peace is what the author wanted and was able to express in that form in which it was expressed.'   Not only do the themes and incidents in the novel reflect his theory of history, Tolstoy iterates this in less narrative terms in the twelve chapters of the Second Epilogue, described as, 'A general discussion on the historians' study of human life, and on the difficulty of defining the forces that move nations.   The problem of freewill and necessity.'   The view of history explored by Tolstoy has had few sympathisers and copious critics.   Tolstoy predicts this disagreement earlier in War and Peace in his description of 'the life of a bee':    A bee settling on a flower has stung a child.   And the child is afraid of bees and declares that bees exist to sting people.   A poet admires the bee sucking from the chalice of a flower, and says it exists to suck the fragrance of flowers.   A beekeeper...The higher the human intellect rises in the discovery of these purposes, the more obvious it becomes that the ultimate purpose is beyond our comprehension.   All that is accessible to man is the relation of life to the bee to other manifestations of life.   And so it is with the purpose of historical characters and nations.    This presupposition of the impossibility of a total, ultimate view of history helps to explain why Tolstoy, in his view of human actio... ...rriere, Tolstoy's Pierre Bezukhov - A Psychoanalytical Study, Melksham: Bristol Classical Press, 1993. Helen Edna Davis, Tolstoy and Nietzsche, New York: Haskell House Publishers Ltd., 1929. I Cannot be Silent - Writings on Politics, Art and Religion by Leo Tolstoy, Chippenham: The Bristol Press, 1989. E. H. Carr, What is History?, St Ives: Penguin Books, 1987. Pauline Marie Rosenau, Post-Modernism and the Social Sciences, Princeton: Princeton University Press, 1992.    Notes 1 F.F. Seeley, Tolstoy's Philosophy of History, From, Ed. Malcolm Jones, New Essays on Tolstoy, Bristol: Cambridge University Press, 1978, p. 176. 2 Ibid., pp. 178 - 183. 3 Edward Wasiolek, War and Peace: The Theoretical Chapters, From, Ed. Harold Bloom, Modern Critical Interpretations - War and Peace, New York, Chelsea House Publishers, 1988, pp. 92 - 97.   

Influence of Reference Groups Essay

When you think about reference groups, there are a number of perspectives that one has to consider. According to Hawkins (2010), a reference group is a group whose presumed perspectives or values are being used by an individual as the basis for his or her current behavior. Thus, a reference group is simply a group that an individual uses as a guide for behavior in a specific situation (p. 227). Groups may be classified according to a number of variables. Four criteria are particularly useful: membership, strength of social tie, type of contact, and attraction. Delta Sigma Theta Sorority, Inc. is a private, non-profit organization whose purpose is to provide assistance and support through established programs in local communities throughout the world. A sisterhood of more than 200,000 predominately Black college educated women, the Sorority currently has over 900 chapters located in the United States, England, Japan (Tokyo and Okinawa), Germany, the Virgin Islands, Bermuda, the Bahamas and the Republic of Korea. The Sorority was founded in 1913 by 22 students at Howard University. These young women wanted to use their collective strength to promote academic excellence; to provide scholarships; to provide support to the underserved; educate and stimulate participation in the establishment of positive public policy; and to highlight issues and provide solutions for problems in their communities (Delta Sigma Theta, 2010). Delta Sigma Theta’s website is about heritage. This site speaks volumes about how these women wanted to be a part of an organization that consists of excellence. These women have a lifetime membership within the sorority. The influence that this organization has, as well as the site, is remarkable. The information on this site will allow younger women that have the desire to go to college and be a part of an organization that helps one excel, not only in school, but also in the workforce as well. This site has all the criteria of a basic reference group. The social ties that this organization has within the world are by far the best for young women that are willing to be a part of change. People that have â€Å"made it† when it comes to financial stability may feel that they are affluent in the society. There are people that have made millions and they do stand alone when it comes to affording â€Å"the better things† in life. Bentley’s website is attractive because the vehicle shows class. The influence that this vehicle has on a person’s financial status is undoubtedly the car of all cars. A Bentley is unmistakable – all it takes is a glance at the twin headlights, matrix grille or the high waistline to know one. The paradox of the car is that although it is instantly recognizable, it takes time and effort to hand-build each one. That’s the assured Bentley hallmark. A hand-built car using the finest quality natural materials takes time. Yet, while others may do things ‘meticulously’ or ‘painstakingly’, Bentley has always been about passion. In fact, our entire reputation rests on the experienced skills and passion of our people, handed down through generations. Many of our people say that they work on each Bentley as if it were going to be their car. They want to get it right. It’s no wonder that every machinist who creates a set of upholstery signs the back of it with his or her initials (Bentley, 2010). Once again Bentley’s website is about class and luxury. This site tells a story about smoothness when it comes to highway. There is nothing like being comfortable while traveling on highway or down the street to the mailbox. People that are attractive to the glitz and glamour will definitely enjoy riding either in the backseat of a spacious vehicle or driving behind the wheel. The six-time success at Le Mans has made Bentley more than a car – it has come to stand for a way of doing things: with spirit, flair, courage, instinctive intelligence and teamwork. Endurance racing has always been a way for us to test, strengthen and improve the cars.

Battle of Stony Point in the American Revolution

Battle of Stony Point in the American Revolution The Battle of Stony Point was fought July 16, 1779, during the American Revolution (1775-1783). In the summer of 1779, the leadership of the Continental Army decided to mount an assault against Stony Point, NY after the position had been occupied by the British. The assignment was given to Brigadier General Anthony Wayne and the Corps of Light Infantry. Striking at night, Waynes men conducted a daring bayonet attack that secured Stony Point and captured the British garrison. The victory provided a needed boost for American morale and Wayne received a gold medal from Congress for his leadership. Background In the wake of the Battle of Monmouth in June 1778, British forces under Lieutenant General Sir Henry Clinton largely remained idle in New York City. The British were watched by General George Washingtons army which assumed positions in New Jersey and to the north in the Hudson Highlands. As the 1779 campaigning season began, Clinton sought to lure Washington out of the mountains and into a general engagement. To accomplish this, he dispatched around 8,000 men up the Hudson. As part of this movement, the British seized Stony Point on the eastern bank of the river as well as Verplancks Point on the opposite shore. General Sir Henry Clinton. Photograph Source: Public Domain Taking possession of the two points at the end of May, the British began fortifying them against attack. The loss of these two positions deprived the Americans of using Kings Ferry, a key river crossing over the Hudson. As the main British force withdrew back to New York having failed to force a major battle, a garrison of between 600 and 700 men was left at Stony Point under the command Lieutenant Colonel Henry Johnson. Consisting of imposing heights, Stony Point was surrounded by water on three sides. On the mainland side of the point flowed a swampy steam that flooded at high tide and was crossed by one causeway. Dubbing their position a little Gibraltar, the British constructed two lines of defenses facing west (largely fleches and abatis rather than walls), each manned with around 300 men and protected by artillery. Stony Point was further protected by the armed sloop HMS Vulture (14 guns) which was operating in that part of the Hudson. Watching the British actions from atop nearby Buckberg Mountain, Washington was initially reluctant to assault the position. Utilizing an extensive intelligence network, he was able to ascertain the strength of the garrison as well as several passwords and the locations of sentries (Map). The American Plan Reconsidering, Washington decided to move forward with an attack utilizing the Continental Armys Corps of Light Infantry. Commanded by Brigadier General Anthony Wayne, 1,300 men would move against Stony Point in three columns. The first, led by Wayne and consisting of around 700 men, would make the main attack against the southern side of the point. Scouts had reported that the extreme southern end of the British defenses did not extend into the river and could be flanked by crossing a small beach at low tide. This was to be supported by an attack against the northern side by 300 men under Colonel Richard Butler. To ensure surprise, Waynes and Butlers columns would make the assault with their muskets unloaded and relying solely on the bayonet. Each column would deploy an advance force to clear obstacles with a 20-men forlorn hope to provide protection. As a diversion, Major Hardy Murfree was ordered to stage a diversionary attack against the main British defenses with around 150 men. This effort was to precede the flank attacks and serve as signal for their advance. To ensure proper identification in the darkness, Wayne ordered his men to wear pieces of white paper in their hats as a recognition device (Map). Battle of Stony Point Conflict: American Revolution (1775-1783)Dates: July 16, 1779Armies and Commanders:AmericansBrigadier General Anthony Wayne1,500 menBritishLieutenant Colonel Henry Johnson600-700 menCasualties:Americans: 15 killed, 83 woundedBritish: 20 killed, 74 wounded, 472 captured, 58 missing The Assault On the evening of July 15, Waynes men gathered at Springsteels Farm approximately two miles from Stony Point. Here the command was briefed and the columns began their advance shortly before midnight. Approaching Stony Point, the Americans benefited from heavy clouds which limited the moonlight. As Waynes men neared the southern flank they found that their line of approach was flooded with two to four feet of water. Wading through the water, they created enough noise to alert the British pickets. As the alarm was raised, Murfrees men began their attack. Pushing forward, Waynes column came ashore and began their assault. This was followed a few minutes later Butlers men who successfully cut through the abatis along the northern end of the British line. Responding to Murfrees diversion, Johnson rushed to the landward defenses with six companies from the 17th Regiment of Foot. Battling through the defenses, the flanking columns succeeded in overwhelming the British and cutting off those engaging Murfree. In the fighting, Wayne was temporarily put out of action when a spent round struck his head. Battle of Stony Point, 1779. Library of Congress Command of the southern column devolved to Colonel Christian Febiger who pushed the attack up the slopes. The first to enter the innermost British defenses was Lieutenant Colonel Francois de Fluery who cut down the British ensign from the flagstaff. With American forces swarming in his rear, Johnson was ultimately compelled to surrender after less than thirty minutes of fighting. Recovering, Wayne sent a dispatch to Washington informing him, The fort garrison with Col. Johnston are ours. Our officers men behaved like men who are determined to be free. Aftermath A stunning victory for Wayne, the fighting at Stony Point saw him lose 15 killed and 83 wounded, while British losses totaled 20 killed, 74 wounded, 472 captured, and 58 missing. In addition, a host of stores and fifteen guns were captured. Though a planned follow-on attack against Verplancks Point never materialized, the Battle of Stony Point proved a vital boost to American morale and was one of the final battles of the conflict to be fought in the North. Visiting Stony Point on July 17, Washington was extremely pleased with the result and offered lavish praise upon Wayne. Assessing the terrain, Washington ordered Stony Point abandoned the next day as he lacked the men to fully protect it. For his actions at Stony Point, Wayne was awarded a gold medal by Congress.

Free Essays on Ways To Get Fired

and not physical activities. If you want to get a point across to anyone it is extremely important not to offend anyone. It is very rare that human on this earth does not need a job. Yes there are a few who grew up with a silver spoon in their mouth. But for the rest of us, we do need to find a study job to support our families and ourselves. Once we are hired there are many rules that need to be met. For instance, there are several factors that we can not help about our... Free Essays on Ways To Get Fired Free Essays on Ways To Get Fired Ways to get fired By: Khai Le Getting fired can be everyone’s nightmare. Not everyone will get along with everyone. There are many reasons why employees lose their job. In some cases, it could be the fact the manager does not like the way you look. You could also be fired because of your fail to reach responsibilities. Or lack of communication with fellow employer, supervisor and customer. There is always someone who judges a person by his or her appearance. In most cases, it is what we all call racism. In today society, we still have ignorant people who immediately assume someone is bad or good by there outside look. With that assumption, an employee could get fired, and we all know that is not right. The most common reason why an employee could get discharged, is the fact the responsibilities that was assign to them, was never met. This could directly lead into argument with the manager. Usually the manager will quickly remove you, and replace you with someone who is capable of doing the work. Communication is one of the strongest factors you have to have to be able to work, especially if you work with people. Just imagine, walking up to a sale person asking for assistance, and all you receive is negative attitude and an unfriendly welcome. How would you feel? I bet you would feel pretty awful and flooded with anger. To communicate you have to be open, and understanding. It’s very important to be able to express your ideas with words and not physical activities. If you want to get a point across to anyone it is extremely important not to offend anyone. It is very rare that human on this earth does not need a job. Yes there are a few who grew up with a silver spoon in their mouth. But for the rest of us, we do need to find a study job to support our families and ourselves. Once we are hired there are many rules that need to be met. For instance, there are several factors that we can not help about our...

You can find it in the instructions paper Essay

You can find it in the instructions paper - Essay Example The film, however, faces the very force and capabilities of the evolving city of Beijing. The globalization setting of Beijing, therefore, could have been the compelling reason of Jia’s filmsetting. Filming of the World in main social places in Beijing city bears a lot of significance as far as migrants experience is concerned. The landscapes like Beijing World Park, Qun’s family clothe store and the Beijing railway station all have cultural and social demands that new migrants from local regions have to learn. Moreover, in all the global landscapes in Zhangkes film, confounding factors such as language barriers, music, dance, clothes, changing technology, dialects’ and the buildings are clearly depicted. These factors have great impact in influencing the very functions and objectives of the global landscape. The elements also shape the values and identities of their inhabitants like the transformation of Qun and Tao. Social regions like the Beijing railway station and Qun’s clothes store all differ in function and locality. However, their roles in transforming the livelihood and behavior of migrants from the local regions are evident. For example, the social places influences the thoughts of the migrants about the immorality issues like prostitution in the city. Some migrants like Mau became prostitutes because of the city’s social places influence while others like Tao managed to conserve her believe on immorality. Moreover, the city social places managed to unite migrants from different ethnic backgrounds, like the relationship between Qun and Taisheng that thrived, despite the two being natives of two different speaking languages. This shows that in a globalizing society, the social hierarchy power of individuals is envisaged in their flexibility to adapt to changes in their vicinity. This adaptation may involve learning a foreign language to help migrants fit in the established culture and the

Moulding Techniques for a Brake Caliper Assignment

Moulding Techniques for a Brake Caliper - Assignment Example End products are normally component products applicable in various industries and applications. Below are samples of brake calipers of the various make of vehicles. It is also known as expandable pattern casting (EPC). LFC involves the substitution of a low solidity foam prototype by liquid metal. It offers the capability of a direct production of nearly any multifaceted geometry including sophisticated cavities and undercuts without tapers and the requirement for considerable completed work (Bhattacharjee 201). Compared to the conservative sand casting methods it has an environmental and economic advantage. The actual LFC-system applies patterns of expandable polystyrene (EPS) for manufacturing applications. These patterns, directly designed to shape, are engrossed in a molding case with binder less sand. The fluid metal, which is dispensed into the molds of the downspouts, vaporizes the EPS model, which is specifically substituted by the metal (Bhattacharjee 201). With the opportunity of assembled prototypes very sophisticated shapes can be generated and the castings can be replicated with amazing dimensional accuracy. Pattern making: The first material needed for pattern production is EPS. The first step in the LFC-procedure is the pre-enlargement of EPS beads. After maturing the beads are gusted into a mold producing the pattern part. The mold is then heated up with steam to expand the beads more and tightly fit the hole of the mold. Hot vapor and enlargement of the beads make them to weld together (Bhattacharjee 201). Cluster assembly. Complicated parts involving hidden cavities and undercuts cannot be molded in one operational step, but are accumulated from pattern sections into a complete pattern. Amalgamation techniques used are heated platen welding, gluing and plugging. In order to augment the effectiveness of the total process, numerous patterns are joined into a cluster and provided with a common gate structure, also made of EPS.