Geographic development of New England Colonies and affects of Research Paper

Geographic development of New England Colonies and affects of Mayflower Compact - Research Paper Example The New England Colonies was a result of the lack of religious freedom in England. When the Puritans immigrated to America, they started colonies where there leaders emphasized Christianity. This group of people were referred to as Puritans since they sought to purify the churches in the New England (Pastoor 388). The authorities banned those who did not agree with them from the colonies to go and initiate their own colonies. Rapid growth of New England colonies was a result of rebels who built colonies of their own. Currently, the New England states are Connecticut, Massachusetts, Vermont, New Hampshire as well as Rhode Island (Bremer55). The geographical location of the Puritans was defined as the part of America that in breath was from 40 to 48 degrees of the north latitude (Bremer 550). The location in length was across the mainland from sea to sea. Agriculture practices of the Puritans went hand in hand with the nature of the environment they lived in. The Puritans cultivated most of their food. They also began fishing and lumbering also took charge. The soil was however thin and rocky hence they could not cultivate cash crops. Because of the nature of the soil, they believed it was a sign from God that encouraged them to work harder in their farms (Pastoor 388). They also kept dairy cattle and the geographical layout supported this economic activity. The Connecticut River valley provided water as well as pasture for the cattle (Bremer 55). The native species of grasses in the bottom and upper locations of the river grew in red sandstone soil, which was the best of soils (Bremer 55). While religion and politics w as the centre of attraction, the Puritans sough to concentrate on the higher pastures, the good soil and practical agricultural use of the same soil. The Puritans were industrious and built a strong economic base. They participated in slave trade; they made and sold iron, pots, kettles and a variety of tools in other

Corporate social responsibility influence consumers behavior Dissertation

Corporate social responsibility influence consumers behavior - Dissertation Example The presentation and discussions of variables that were collected by use of the questionnaire are therefore undertaken below. RESULTS AND DISCUSSION General Information Gender of Respondents From the responses that were received, it was found upon sorting of responses according to the gender or sex of respondents that forty three (43) of the respondents were females whereas eight (8) respondents were males. From the data, it can be said that there was an apathy on the side of the males when it comes to responding to customer behavior related questions as the ratio of males to females is more than 1:5. In relation to the literature reviewed, it can be said that there are more females who are more enthused about keeping a specific shopping (customer) behavior as compared to males. Age of Respondents Two major categorizations were provided for respondents to choose from in terms of their ages. From the coding that was done, it was realized that a specified pattern as shown in the age gr oupings of respondent. From the responses, it can be noted that there were more respondents within the age group of 18 to 24, which had as many as 43 call ups as compared to those aged 25 to 34 within just 8 call ups. This trend could actually suggest that M&A has more young customers as compared to older customers. Among other reasons, the fact that most products and services offered by the company are highly oriented for tertiary education students who often fall in the age group of 18 to 24 (Burke et al, 2006). Employment Status of Respondents Respondents were asked to indicate as part of the general and demographic information, their employment status. The responses that were sampled have been presented in the table below. Employment Status Number of Respondents Percentage Part time student 1 1.86 Full time student 45 83.3 Unemployed 3 5.56 Part time employed 2 3.702 Full time employed 3 5.56 Retired 0 0 Total 54 100 From the table, it can be seen that as many as 83.3% of the re spondents were full time students. This is a direct confirmation of literature that M&S is more popular among tertiary education students because of the line of products and services that the company offers. Other contributing factors to this are the strategic location of shops undertaken by M&A in various university campuses as a marketing strategy (Weber, 2010). 5.56% each were unemployed and full time employed workers whiles 3.7% were part time employed workers. There was 1.86% part time student with no retiree answering to the questionnaire. Average income of respondents A range was set for the average annual earning or income of respondents. The range was given ?10,000 interval and responses from participants is represented below. Annual income Number of Respondents Percentage 0 to 10,000 45 88.24 10,001 to 20,000 3 5.88 20,001 to 30,000 3 5.88 30,001 to 40,000 0 0 Over 40,000 0 0 Retired 0 0 Total 51 100 The table shows that greater percentage of respondents too an annual sala ry of ?10,000 or less. Their percentile is given as 88.24 whereas those who took more than ?10,000 but less than ?20,000 had a percentage representation of 5.88%. The same percentage was recorded for those taking between ?20,000 and ?30,000. Based on literature that shopping activities are common among people who make average minimum wage

Uniforms in schools today Essay Example for Free

Uniforms in schools today Essay Students wearing uniforms prevents violence in todays schools. Uniforms are equal and give students a sense of security because everyone is the same. Students need to be able to go to school to learn, that should be the sole purpose of going to school. These days most schools dont have dress codes and students wear whatever they want. These kinds of clothing can be distracting and disrespectful to the students. Girls wear revealing shirts and tank tops, guys wear pants that fall down, and they also wear distracting types of shirts with violence or vulgar language on them. Uniforms are a lot more respectable and a lot more mature, and they wont be a distraction to the students and the teachers. Now, some people would say that uniforms are a little too formal. There are many different kinds of uniforms however. Private schools such as catholic schools have more formal uniforms with collared shirts and plaid skirts for the girls. For the boys collared shirts, ties and cargo pants. Students these days really take advantage of the dress code, they wear whatever they want and a lot of them get in trouble for it. Many students are sent home during school hours because their clothing is inappropriate. These students waste valuable learning time, and distract other students from learning as well as the teacher. Disrupting the class can be prevented if students wear uniforms. Uniforms could solve the problem that every school faces, the problem of dealing with students who break the rules of the dress code. Unfortunately, there are many other problems in the schools these days but uniforms are a good place to start. Uniforms come in many different shapes and styles. No one uniform is alike. Many uniforms are similar to the schools colors, but most are not as formal as you would think. Uniforms are made for one purpose only, to make students equal. Students dont understand the importance of a good education. Some people disagree with uniforms because they believe in freedom of speech. They believe that they have the right to wear whatever they want to. People like to express themselves by the way of wearing their own style. Students express themselves in many different ways, but the most popular way that they express themselves is wearing what they want. Lots of students have different opinions on the situation, some agree and some disagree. My sister  goes to a Catholic school and she wears a uniform everyday. She enjoys the strict atmosphere of the school and she loves wearing a uniform. In her opinion, its saves money and you dont have to worry about what to wear everyday. Now some people would say that uniforms are expensive and you only wear them for a few years, plus there are different kinds of uniforms for different seasons. Plus people grow and you cant return them after wearing them. You can resell them but you can never get your money completely back. However, most people who go to private schools are rich, so they dont really care about spending money on uniforms every few years. Education gives you the ability to learn. It gives you a broad aspect of what life would be like after high school and college. A lot of people strive for a higher education, college. They believe that having a higher education will make them succeed in life more than just having a high school education. This may be true, but it isnt exactly a proven fact. Some people just arent made to go to college. Some do just fine with a high school degree. Everyone is different, it just depends how motivated you are and how far you want your education to go. The most important thing is an education, it shows how much you really want to learn by how far you go. Uniforms can do a lot of good in schools, it can prevent violence and keep students on track in school. Uniforms are not distracting and everyone is equal, no one can judge anyone if they are all wearing the same thing.

Tensile Strength Test Of Concrete Engineering Essay

Tensile Strength Test Of Concrete Engineering Essay Concrete is a widely used construction material in the world. It is one of the most versatile, durable and environmental friendly material. Most importantly concrete is good at compression and is completely non-combustible, which makes it popular in this industry. But concrete has low tensile strength causing concrete to behave in brittle manner. This nature in concrete has lead to numerous test and research in order to increase the tensile properties of concrete. History of concrete dates back several thousand years to the day of the ancient Egyptians, the Greeks and the Romans. These early concrete compositions were based on lime although the Romans are known for their development of pozzolanic cement and lightweight concrete based on pumice. The credit for the introduction of steel as reinforcement is variously attributed to Lambot in 1855 for ferrocement boats, to Monier in 1867 and to Hennebique in 1897 who built the first reinforced concrete frame building. But the Notable steps forward in this century have been the introduction of pre-stressed concrete by Freyssinet in the 1940s and the motorway-building boom of the 1960s involving concrete pavements and bridges. Although the vast majority of concrete structures have performed satisfactorily for many years such progress has not been made without its problems. 1.1 HIGH STRENGTH CONCRETE High strength is a concrete which has a cylinder compressive strength greater than 6000psi or 42 MPa. Generally, for building high rise structures, concrete with cylinder compressive strength over 140 MPa is used. In some laboratories in United States and Europe, a concrete with strength over 315 MPa has been produced, however, the problem with such strength is that it reduces the ductility of structure. Higher strength concretes leads to cost effective structural systems. Using such concrete, overall weight of the systems on the foundation reduces, resulting in size reduction, increase in available occupancy space, and thus cost of components. Many factors are taken into account for making a high strength concrete. Generally, such a concrete contains a higher Portland cement, strong aggregates, and a low water/cement ratio. Now-a-days, addition of super plasticizers, blast furnace slag, polymers, water reducing admixtures or silica fume are common 1.2 HISTORICAL DEVELOPMENT OF HIGH STRENGTH CONCRETE In last half decade, the compressive strength of commercial concrete has tripled approximately from 5,000 psi to 14,000 psi. In 1950s, a ready mixed concrete of design strength of 5000 psi was called as high strength. A decade later, Washington state highway department specified 6000 psi strength concrete for prestressed girders. High strength concrete made constructions such as 311 South Walker Drive concrete building; East Huntington, W.V., and other long span cable stayed bridges. Increased use of mineral admixtures and chemicals in 1960s lead to an increase in attainable strength. In 1973, Japan national railway built three high strength concrete bridges and they were found to meet all expectation by serving for over 20 years. Chicago city played a very important role in the evolution of commercial high strength concrete. The inventors of micro-silica concrete (MSC) realised that Chicago inner city development would be quite beneficial , which indeed was, and hence, with appointing high strength concrete pioneer, William Schmidt, they targeted an increase upto 6000 psi for a new 40 story tall Outer Drive East Condominium Project, using normal weight concrete. In 1072, the first 7500 psi concrete was used for a 52 story tall Mid-continental Plaza. Later, in 1974, 9000 psi concrete was supplied to 74 stories tall Water Tower Place, which was the tallest building at that time. In late 1980s, very high strength concrete as being successfully developed in many parts of North America. One of the best examples is Two Union Square in Seattle which is a 220 m tall, 58 story building. The original concrete specified for them was 14000 psi at 28 days, however, to incorporate a static modulus of elasticity of 50 Gpa, the concrete was upgraded to a compressive strength around 19000 psi. A test conducted after 4 years found that the compressive strength and modulas of elasticity were 19900 psi and 5.6 Gpa, respectively. Now-a-days, 14000 psi at 56 days is commonly used in many metropolitan cities. 1.3 MOTIVE FOR DEVELOPMENT of High strength concrete Modern methods have improved the quality of concrete by many folds. Aspects such as, long term failure studies, development of effective and powerful instrumentation, molecular structure of material, increased need of materials better for larger structures and increased ductility, and decrease of cost effectiveness of traditional material have redefined concrete. These days, concrete structural systems build from 15000-20000 psi concretes can be found quite easily. However, factors such as newer components or admixtures, microstructural studies, better material selection proportioning, long term performance, blended cement compositions, placement techniques and others; provide an ample scope of improvement. For e.g., use of slags and pozzolans as cementitious replacements contribute to energy conservation and disposal of industrial by-products, besides higher strength. Improved cements such as densified cements (DSP) and macrodefect free cements (MDF) and composite advancements, for e.g., slurry infilterated fiber concrete (SIFCON), have allowed the builders to achieve concrete with strengths up to 300 MPa. A very nice example of such concrete use is the undersea tunnel connecting British Isles and France. 1.4. APPLICATIONS OF HIGH STRENGTH CONCRETE The use of high strength concrete has been increasing considerably high in construction world because of both technical and economical advantage. The use of HSC provides more economical construction due to reduced member cross-section and dimensions. HSC has been extensively used in high rise building and highway bridges. Major area of use has been high rise buildings. Tall construction feature whose construction would have been not possible in terms of durability and long term performance have been successfully constructed using HSC. The use of HSC helps in the reduction in structural member size, reinforcement percentage increasing floor space and decreasing dead weight. One of the examples of high rise building is the Mercantile Exchange building in Chicago which used 9000psi concrete. The other application of HSC is in prestressed Bridge girders. The use of HSC would allow using greater spans for a given number of girders as compared to NSC. Again for a given span, use of HSC provides economical cost by reduction in labour cost in the production of girders, transportation cost, erection cost and overhead expenses. Japanese I-shaped, box and rectangular section bridge girders have been constructed using 8500psi concrete where the spans are between 100 to 280 ft. One of the examples is Bennett Bay Bridge, Idaho which has which 1730ft segmental girder with two centre spans of 520ft and end span of 320ft. 1.5 DISADVANTAGES OF HIGH STRENGTH CONCRETE HSC has brought about a lot of construction possibilities which would not have been possible with NSC. However HSC comes with some disadvantages too mainly because of lack of research and information about its behaviour in real construction field. As HSC is composed of mineral and chemical admixture, increased quality control is required. In codes minimum thickness and cover have been specified preventing realization of full benefit of using HSC. It can be difficult to cure adequately due to self-desiccation of low water/cement ratio mixes. HSC possess increased permeability which makes curing difficult as it prevents applied curing water from compensating any initial moisture loss. These are the disadvantages relating the use of HSC in real construction filed. 1.6 RESEARCH OBJECTIVES The main objective of this research is to determine the true uniaxial tensile strength of concrete by carrying out a series of cylinder splitting test, modulus of rupture test and cylinder compression test. The research aims to utilise the simple correction factors proposed by Raoof and Lin (1999) which aims to overcome the shortcomings associated with the closed form formula used in the Brazilian concrete splitting test. Many experimental tests on various concrete mixes had been already carried out for the verification of the proposed correction factor. The criteria for this research were based on 3 days compressive and tensile strength of high strength concrete with total of 16 batches using two types of coarse aggregate. Also few batches testing were done for normal strength and self compacting concrete. In this research effect of constituent materials will also be studied. The purpose of this research is to compare and contrast the use of correction factors with the results the results obtained from previous experiments. 1.7 RESEARCH SCOPE The scope of this research included computation of splitting tensile strength, compressive strength and modulus of rupture on normal, high and self compacting concrete. The mineral admixtures, which have been used for this research project, were compromised of silica fume, fly ash. The superplasticiser and viscosity modifying admixture that was used in this research were Sika ViscoCrete10 and structure 480respectively. All the admixtures used in this research are used in real life applications. 2. LITERATURE REVIEW High strength concrete has been classified as one of the advanced construction materials. High strength concrete has both economical as well as durability benefits. It helps in the reduction in formwork area and cost with the accompanying reduction in shoring and stripping time due to high early age gain in strength. The composition of high strength concrete constitutes of mineral admixtures which provides a base for the use of waste products. 2.1 PREVIOUS RESEARCH WORK ON HIGH STRENGTH CONCRETE High strength concrete uses various mineral admixtures such as silica fume, fly ash, granulated blast furnace slag and superplasticiser which increase the strength of High strength concrete. Most applications of high-strength concrete have used the strength property of the material. However, high strength concrete may carry various other characteristics that can be of great advantage for construction industry. Various researches have been carried out on high strength concrete in order to study other characteristics of HSC. Some research work that had been carried out on high strength concrete has been summarised below: M. Mazloom A.A. Ramezanianpour, J.J. Brooks(2004): carried out in joint collaboration between UK and Iranian university presented experimental work on short- and long-term mechanical properties of high-strength concrete containing different levels of silica fume. In this research the cement was replaced by silica fume with 0%,6%,10% and 15%. The researchers found that as the proportion of silica fume is increased the workability of concrete decreased but its short-term mechanical properties such as 28-day compressive strength and secant modulus improved. The mix portion sued in this research is shown in the table below. For each mix, the following specimens were made: 24 samples of 100 mm cubes for compressive strength; eight 80 x 270 (diameter x length) mm cylinders for creep; four 80x270mm and four 150x300mm cylinders for shrinkage; two 80270 mm and two 150x300mm cylinders for swelling. From the test carried it was also established that the percentages of silica fume replacement did not have a noticeable effect on total shrinkage. Moreover the compressive strength of the concrete mixes containing silica fume did not increase after the age of 90days. K. Lahlou, P.-C. Aitcin O. Chaallal (1992): This research presents the behaviour of High-strength concrete under confined stress. The investigation was carried out on three 28 day strength levels: 50, 80 and 115 MPa where the actual mixes used resulted in strength of 47, 78 and 115MPa.The study showed that improved confinement provides increased compressive strength. As a result a new ultrahigh-strength concrete of strength 250MPa was produced. Other outcome of the research was that the confinement efficiency increased with the increase in the compressive strength of the concrete. Zhen-jun He, Yu-pu Song (2010): this is one of the most recent researches carried out in china to study the failure criterion and triaxial strength of HSC before and after high temperature. HSC is susceptible to spalling, or even explosive spalling when subjected to rapid temperature rise as in the case of a fire. Though high strength concrete has been greatly used but very little research has been carried about the effect of high temperature on the concrete structure Triaxial tests were performed at all kinds of stress ratios after exposure to normal and high temperatures of 20,200, 300, 400, 500, and 600  °C, using a large static-dynamic true triaxial machine. The study showed that no explosive spalling was observed during the high temperature temperatures ranging from 200  °C to 600  °C. Also there was no change in the failure modes with the increase in the temperature where the failures under uniaxial tension were tension failure. The uniaxial compressive strength of plain HSHPC was not decreased after 200 and 300  °C. The brittleness-stiffness of HSHPC specimens between 200  °C and 300  °C is higher than that above 400  °C. The temperature around 400  °C is critical to the ultimate strength that decreases rapidly. The increasing extent of the triaxial to uniaxial compressive strength depends on the stress states, the stress ratios, and the brittleness-stiffness of HSHPC after different temperatures. M.I. Khan, C.J. Lynsdale (2002): the corrosion of steel reinforcement is a common cause of deterioration in reinforced concrete. The use of blended cements or supplementary cementing materials decreases the permeability, thereby increasing the resistance of concrete to deterioration by aggressive chemicals. The investigation carried out by Khan and Lynsdale (2002) aimed at developing HSC and carryout investigation into the optimisation of blended cementitious system for the development of HSC. PFA at 0%, 20%, 30% and 40% (by weight) was incorporated as partial cement replacement. To these blends, 0%, 5%, 10% and 15% SF replacement levels were incorporated to make various binary and ternary cementitious combinations. Cube compressive strength and cylinder splitting strength test was carried out and the oxygen permeability was measured using the given equation: From the experimental results it was noticed that as curing age increases, the reduction in strength with increasing PFA content becomes less apparent, especially for PFA contents J.J.Brooks, M.A. Megat Johari, M. Mazloo (2000): Chemical admixtures play a vital role in the production of High-strength concrete. Metakaolin (MK) is one of the new admixture commercially introduced. It is very important to know the setting characteristics of concrete as it helps in the scheduling of concrete construction operations. In this research the effect of chemical admixtures and shrinkage reducing admixtures (SRA) on the setting time of HSC was investigated using the penetration resistance method (ASTM C 403). The penetration resistance (P) of all the different concrete mixes was expressed as P=aebt i.e. P was expressed as the exponential function of time. The general effect of the admixture retarded the setting times of HSC while the SRA had significant retarding effect when used in combination with superplasticiser. As a whole the conclusive statement is that increasing the levels of SF, FA provides greater retardation in the setting time of HSC. 2.2 PREVIOUS WORK ON TENSILE STRENGTH PROPERTIES OF HIGH STRENGTH CONCRETE Tensile strength of concrete is one of the basic and very important properties of concrete. The knowledge of tensile strength is very important in designing concrete structure. Various tests have been carried out in order to determine the tensile strength of concrete. Traditional direct tensile strength test are not commonly acceptable as it suffers many drawbacks. In these tests there is huge stress concentration near the grips and non uniform distribution within the sample. Researches have shown that results from such experiment are low and coefficient of variation is low. Hence more research has been carried out in order to find the true uniaxial tensile strength of concrete. Zhuhai lin and Laurence Wood (2003): After the proposal of correction factor by Raoof and Lin (1999), further research into the correction factor was carried out by Lin and Wood in 2003. In this research assuming uniaxial tensile strength and properties of the concrete, the Brazilian cylinder splitting test was analyzed by the isoparametric nonlinear finite strip element. The result from the research showed that at the onset of cylinder failure the tensile strength along the vertical diameter of cylinder was smaller than the assumed uniaxial tensile strength which means the splitting test underestimates the uniaxial tensile strength of concrete. The study also showed the effect of width of packing strip together with the ratio of (ft/fc) for the compressive strength constant at 30 N/mm2 and showed a linear relationship. According to Lin and Wood the range of correction factor for 30N/mm2 is about 1.09 to 1.40 for packing strip of 12mm, 1.10 to 1.44 for 13mm width, 1.09 to 1.41 for 14 mm and 1.09 to 1.39 for 15mm packing strip width V. Ramakrishnan, Y. Ananthanayayana, K. C. Gopal : As we already mentioned that different test have shown different values of tensile strength for the same concrete mix. V. Ramakrishnan and his associated carried out a research to compare the results in the various tests and to study the uniformity of the results. In this research over 600 specimens were tested for 28 days target strength. A comparative analysis of tensile strength test was carried out and the results were compared against cube compressive strength as shown in the plot above. After laboratory work it was found that modulus of rupture does not give the true tensile strength but only gives the highest value of tensile strength and lies between 1.3 to 2 times the cylinders splitting strength. The cylindrical splitting test was taken satisfactory as it gave more uniform and consistent results than other tensile strength tests. M.F.M. Zain et al: computation of correction factor for the determination of true tensile strength of HSC depends upon the compressive strength of HSC. It is very important to show the relationship between tensile splitting test and compressive strength of HSC. Zain and associates carried out a research in 2002 in order to determine the relation of splitting tensile strength of concrete with compressive strength, water/binder (W/B) ratio and concrete age. After the investigation a relationship between tensile strength, compressive strength and concrete by age was proposed which is . Plot for this relation is given below. The relation given above for the prediction of tensile strength of concrete was compared with French code, ACI code and CEB/FIP code and found to be very close. Hence this equation can be helpful in estimating the Splitting tensile strength of HSC. S Bhanja, B Sengupta(2005): Our research aims to use silica fume as one of the mineral admixture on HSC mixes. Many researches have been carried out to investigate the mechanical effect of silica fume on HSC but very few are carried out in order to analyse the effect of silica fume on tensile strength of concrete. S. Bhanja (2005) carried out research to develop a better understanding on the isolated contribution of silica fume on the tensile strength of concrete. In this experiment 32 mixes with silica fume binder ratio from 0.0 to 0.3 were tested for 28 days strength. From the research it was found out that the use of silica fume improves the tensile strength of concrete and depends upon the water cementitious material ratio of mix. Flexural strength showed greater development than splitting tensile strength. Two expressions were developed to establish the relationship between flexural strength, split tensile strength and compressive strength of silica fume concrete. It was also established that increase in tensile strength beyond 15% of silica replacement was almost irrelevant. 2.3. TENSILE STRENGTH TESTING OF HIGH STRENGTH CONCRETE Although concrete is not normally designed to resist direct tension, the knowledge of tensile strength is of value in estimating the load under which the crack will develop. One of the most well known mechanical properties of concrete is that the tensile strength is 8 to 10 times less than compressive strength. Because of such a low tensile strength, the crack can be seen on the surface of concrete structure. Tension failure is still one of the most important issues because it influences the serviceability significantly. Tensile strength is one of the most important parameters used to evaluate tensile failure of a concrete. Tension tests are needed for concrete as complement to standard compression test in order to obtain a better assessment of structural performance. According to various research and literature review carried out it has been revealed that direct tension test are unsuitable as the results from such tests suffer from inconsistencies due to several uncontrolled variables. It is difficult in this test to avoid stress concentration near the grips and non-uniform stress distribution within the sample. Evans and Wright confirm that the results obtained in the direct tension test of concrete are low and the coefficient of variation is great. Hence this type of test is no longer accepted as reliable. The splitting test is rather simple to perform, does not require other equipment than that needed for the compression test, and gives an approximately similar value of the true tensile strength of concrete (Neville, 1971). According to investigation of splitting tensile strength carried out by O,Neil (2002) , the addition of silica fume, high-range water reducing admixtures and special curing conditions the tensile strength of the concrete wa s higher than that of conventional concrete. The tensile tests that are commonly used and that has been used in this project are detailed in full below: 2.3.1. MODULUS OF RUPTURE OR FLEXURE TEST A direct application of a pure tension force, free from eccentricity is difficult, and is further complicated by secondary stresses induced by the grips or by embedded studs. Because of these difficulties, it is preferable to measure the tensile strength of concrete by subjecting a plain concrete beam to flexure. This is in fact one of the two standard tension tests. The theoretical maximum tensile stress reached in the bottom fibre of the test beam is known as the modulus of rupture. The value of modulus of rupture depends on the dimensions of the beam and, above all, on the arrangement of loading. Two systems are used: a central point load, which gives a triangular bending moment; and symmetrical two-point loading, which produces a constant bending moment between the load points. Since concrete consists of elements of varying strength, it is to be expected that two-point loading will yield a lower value of the modulus of rupture than when one point load is applied. The centre- poin t loading has been discontinued both in United Kingdom and the U.S. Figure 4 Two point flexure test BS 1881: Part 4:1970 prescribes third-point loading on 150 by 150 by 750mm beams supported over a span of 600mm but when the maximum size of aggregate is not more than 25mm, 100 by 100 by 500mm beams with a span of 400 mm may be used. There are four possible reasons why the modulus of rupture test yields a higher value of strength than a direct tensile test made on the same concrete. The first one is related to the assumption of the shape of the shape of the stress block. The second one is that accidental eccentricity in a direct tensile test results in a lower apparent strength of the concrete. The third is offered by an argument similar to that justifying the influence of the loading arrangement on the value of the modulus of rupture. Fourthly, in the flexure test, the maximum fibre stress reached may be higher than direct tension because the propagation of a crack is blocked by less stressed material nearer to the neutral axis. Thus the energy available is below that necessary for the formation of new crack surfaces. The requirement for ASTM Standard C 78 75 are similar to those of BS 1881: part 4: 1970. If fracture occurs within the central one-third of the beam the modulus of rupture is calculated on the basis of ordinary elastic theory, and is therefore equal to PL/ (bd2). Where P= the maximum total load on the beam L=span b= width of the beam d= depth of the beam. If however fracture occurs outside the load points, e.g. at a distance a from the near support, a being measured along the centre line of the tension surface of the beam, then the modulus of rupture is given by 3pL/(bd2). This means that the maximum stress at the critical section, and not the maximum stress on the beam, is considered in the calculations. 2.3.2. CYLINDER SPLITTING TEST The splitting tensile test is used worldwide to measure the tensile strength of concrete. In splitting test a cylindrical or prismatic specimen is compressed along two diametrically opposed generators as shown in the in Figure 5 to prevent multiple cracking and crushing at the points of loading, the load is distributed through two bearing strips whose width differs in the various standards. If the material behaviour is linear-elastic, this geometry leads to nearly uniform tensile stress alone the plane of loading, and the expected rupture mode is the splitting of the specimen in two halves across that plane. In the case of concentrated loads, the maximum tensile stress on this plane can be calculated by à Ã†â€™ max = Where à Ã†â€™ max is the maximum tensile stress in the specimen when the applied load is P, D and B are the specimen depth and thickness respectively. Figure 5 Specimen positioned in a testing machine for determination of splitting tensile strength. Following the standards the maximum tensile stress at failure is a material property called splitting tensile strength. If the load-bearing strips are narrow enough to consider the loading concentrated, and the material behaviour is linearly-elastic -brittle is close to the tensile strength determined by ideal uniaxial tensile test. The tensile strength is evaluated in the standards by fst = Where Pu is the maximum load recorded during the test. The splitting tensile strength is then calculated on the assumption of a hypothetical load bearing strip of zero width. One of the main advantages of the splitting test is that only external compressive loads are required. A cylindrical or prismatic specimen is compressed along two diametrically opposed generators so that a neatly uniform tensile stress is induced in the loading plane. To avoid local failure in compression at the loading generators, two thin strips, usually made of plywood, are placed between the loading platens and the specimen to distribute the load. The specimen fails by splitting because of the induced tensile stress state. The maximum value of the tensile stress, computed at failure from the theory of elasticity, is the splitting tensile strength, ordinarily assumed in the standards to be a material property. The splitting test is simple to perform and gives more uniform results than other tension tests. The strength determined in the splitting test is believed to be closer to the true tensile strength of concrete than the modulus of rupture the splitting strength is 5 to 12 percent higher than the direct tensile strength. It has been suggested, however, that in the case of mortar and lightweight aggregate concrete, the splitting test yields too low a result. With normal aggregate, the presence of large particles near the surface to which the load is applied may influence the behaviour. According to Minders et al, 2003 as the age and strength increase the ratio of tensile to compressive strength decreases (figure ..) Probably due to the effect of drying shrinkage cracks air curing when compared with moist curing reduces the tensile strength more than the compressive strength.

Renewable Energy for a Sustainable Future :: Science Research Term Papers

Renewable Energy for a Sustainable Future Abstract In order to move toward a more sustainable Colorado Springs we must address the system of conventional energy production that fuels the city. Colorado Springs experiences an annual growth rate of 2.5%. The increase in population from year to year results in an increase in the demand for affordable energy. This growing demand in turn places considerable stress on the finite resources that produce this affordable energy. There is a daunting amount of scientific evidence warning people about the environmental and health effects associated with coal-fired power plants, coal mining, and the combustion of natural gas. As we exhaust our finite resources and become increasingly aware of the harm that conventional energy production has inflicted upon our communities, we must look to renewable energy sources. These renewable energy sources provide a cleaner, safer, and more sustainable alternative to coal and natural gas. Obstacles in the way of making the shift from conventional to renewable energy include cost considerations and questions of reliability. Education is the key to overcoming these obstacles. A community that is informed about the drawbacks of conventional energy and the benefits of renewable energy should demand a healthier and more sustainable energy program from Colorado Springs Utilities. We propose to educate the people of Colorado Springs through the formation of a Sustainable Energy Task Force. This task force will increase each individual’s awareness of their impact on the health of the community and environment; and will work with city council and CSU to develop a cohesive Sustainable Energy Plan for Colorado Springs. Colorado Springs is community addicted to cheap energy. Unfortunately, most citizens do not realize the true cost of conventional energy production, which is considerably subsidized by taxpayers. When one factors together the adverse health effects and environmental degradation that result from conventional energy production the cost rises even more dramatically. Customers of Colorado Springs Utilities are unaware of these effects and see coal and natural gas as the cheapest forms of energy available. Although renewable energy appears more expensive at face value, a deeper look reveals an energy source that is much cleaner and more sustainable for future generations. The people of Colorado Springs must be educated about the adverse effects of conventional energy production and the opportunities that renewable energies hold for the future in order to maintain the health of the environment and society of which they are a part.

Animal Cruelty :: essays research papers fc

Animal Cruelty The topic of animal cruelty is one of great importance to the wold today. Why we humans have the right reserved to treat animals as lesser individuals is beyond me. Animals are fulfilling their part in the ecosystems and communities of the earth, and to the best extent that they are able. For example, a spider is being the best possible spider that it can be, spinning webs and working diligently at what it knows best, not bothering any creatures of the earth besides the ones which it needs to capture for food. We, as humans, decided that we are a much advanced life form and can basically treat anything else in this world in ways which we cannot imagine being treated. As a result the threads holding our earth together tightly in the balance are being slowly unraveled to lead into ultimate self-destruction. In 1988, 16, 989 animals died in laboratories in the United Kingdom. This was due to such tests as acute and chronic toxicity experiments, where the animals are forced to consume substances such as perfume, make-up and other beauty products and are often literally poisoned, their systems literally overloaded by the substance in question. Another testing method is the Lethal Dose 50 percent test or LD50. In this procedure at least half of the animals must die in order for the government to figure out how much a human can ingest without dying. In one such test some animals were fed 4. lb. of lipstick and one ended up dying of intestinal obstruction. In another, 7 pints of melted eye shadow was fed to rats. In yet another, mice were wrapped in tin foil and grilled in ultraviolet light to test a sun block cream for a total of 96 hours. The results of the test were that the longer the mice stayed in the rays, the more sunburnt they got. But that is not all. A wax product used in many cosmetics was dosed into animals by a stomach tube. The amount that they used is equivalent to feeding 1 Â « lb of the stuff to humans. The animals involved soon began salivating, bleeding from the nose and mouth, and had extreme diarrhoea. As the test progressed some more, the animals became emaciated and unkempt, had congestion in the lungs and kidneys and solid wax in the stomach. The infamous Draize eye test cannot be forgotten either. Chemicals are instilled into the eyes of rabbits in stocks, often for up to seven days. And because their eyes are physiologically different from ours, they cannot produce

The Pros and Cons

ENC 1011 Birth Control in American Society The Pros and Cons â€Å"On May 9, 1960, the Food and Drug Administration (FDA) approved the marketing of the first birth control pill in the United States. † The battle over birth control waged on long before F. D. A’s approval. Since its creation, arguments both pro and anti birth control have been immense. From religious beliefs to freedom of choice, both sides still have yet to find a middle ground on this matter. Whether negative or positive, birth control has had a tremendous impact on American society with no compromise in sight.The pro birth control side believes we must know in the war of birth control what exactly we are fighting for, teens are going to have to sex before marriage regardless, and parents have to do what they can to minimize the effects of it. According to one thinker, â€Å"The first step in determining the dispense of birth control is acknowledging the frequency of non-marital sex, and willingness to consider its consequences. † Backed by Susan Jacoby studies, indicating that the percent of the population having sex by the age of 21 rose from 40% to 70% were for the entire population.Today, 77% of men and women will have had sex, including 75% who will have had premarital sex, by the age of 20. Consequently, 95% of the entire population will have had sex outside of marriage by the age of 44, and they will overwhelmingly have done so with someone other than a person they will eventually marry (Jacoby). Naomi Cahn, a professor from George Washington University Law School once stated, â€Å" The war for non-premarital sex was lost long ago, we’re now combatting the results of the loss with our main weapon being birth control. Once conceding defeat, the belief is that parents can neutralize the consequences of teens having sex by giving them birth control. On the other hand the anti birth control side; tends to believe by parents giving birth control to teens, they ar e in fact promoting teen promiscuity. According to research done by Richard John Neuhaus commenting on giving birth control to kids, â€Å"To do so would be to try something that possibly no society has tried before: to state publicly that there are no social standards or sanctions with respect to the sexual activity of young people.Giving teens birth control would be parents way of saying, I expect you to have sexual intercourse with out verbally saying it. This would make it appear to be normal, thus by virtue lending a helping hand in teens having sexual intercourse (Neuhaus). Feeling dispense of such devices would led to lower standards in American society is more harmful then beneficent. Most people who are pro choice refute the notion of more harm done then good in usage. Joyce Arthur an activist for birth control was a part of several studies conducted in the U. S.Joyce cited â€Å"The consequences of mothers and fathers parenting children they did not want to bear resulted in damages both to the children and parents. † The children were significantly more likely to have mental handicaps, they performed significantly worse academically and were twice as likely to have a record of juvenile delinquency according to Dr. Jeffrey Peipert of Washington University in St. Louis in a study published. Activist states not only are we putting our future in jeopardy by denying them birth control, but we are also damaging our young teens.Teens whom had to bear unwanted children have shown consistent patterns of anti-social behavior and neglect by their own parents. Joyce argues â€Å"These issues are more detrimental than the marginal increase in sexual activity amongst teens. † Thus parents giving birth control devices to teens help society more according to Joyce Arthur. Many of those against birth control believe we cannot foresee the full impact of parents actively giving out birth control. According to Douglas J. Besharov,† Parents actively pushing birth control to teens ought to be aware of the possible increase in sexually transmitted diseases (STD).Citing a vast number or birth control devices protect against pregnancy but aren’t efficient at fighting the diseases. Besharov stated, â€Å"If only can we have our parents weigh the unwanted birth of a child, to the lost of a child to an S. T. D, they may see the lesser of two evils in promoting birth control. No method outside of condoms has proven to offer any protection from a S. T. D. Besharov asks, â€Å"Are we so concerned with unwanted births that we’d disregard the health of the living? † The debate on whether we should or should not give birth control to teens as gone on for years and will continue on for the foreseeable future. Both sides have made very valuable and valid points. There is no right or wrong answer it just a matter of beliefs and preferences. The only answer lies with in the person, if one chooses to have sex, with out ques tion birth control should be readily available to them, to protect themselves from consequences. However, if there is any error at all in these debates it would be the notion that we should assume that all our teens are having sex.With this assumption for us to actively push birth control could indeed send the wrong message. For those who aren’t actively having sex it could be due to the fact that they don’t have their hands on birth control devices and by us giving it to them we could also be giving them the green light to have sex. Works Cited Bartells, F. K. â€Å"Teens Should Not Have Access to Emergency Contraception Without Parental Consent. † Birth Control. Ed. Margaret Haerens and Lynn M. Zott. Detroit: Greenhaven Press, 2012. Opposing Viewpoints. Rpt. rom â€Å"The New ‘Emergency Contraception': A Dark and Deadly Pill. † 2010. Gale Opposing Viewpoints In Context. Web. 24 Oct. 2012. Cahn, Naomi, and June Carbone. â€Å"Birth Control Asserts Feminist Values and Is Socially Beneficial. † Birth Control. Ed. Margaret Haerens and Lynn M. Zott. Detroit: Greenhaven Press, 2012. Opposing Viewpoints. Rpt. from â€Å"Contraception: Securing Feminism's Promise. † The George Washington University Law School Public Law and Legal Theory Working Paper. Vol. 476. 2009. Gale Opposing Viewpoints In Context. Web. 4 Oct. 2012 Neuhaus, Richard John. â€Å"Long-Term Contraceptive Devices Promote Teen Promiscuity. † Teens at Risk. Ed. Auriana Ojeda. San Diego: Greenhaven Press, 1999. Opposing Viewpoints. Gale Opposing Viewpoints In Context. Web. 24 Oct. 2012. Parenthood, Planned. â€Å"Teen Access to Abortion Should Not Be Restricted. â€Å"The Abortion Controversy. Ed. Emma Bernay. Detroit: Greenhaven Press, 2007. Current Controversies. Rpt. from â€Å"Child Custody Protection Act: Hearings on H. R. 1218. † 1999. Gale Opposing Viewpoints In Context. Web. 24 Oct. 2012. The Pros and Cons ENC 1011 Birth Control in American Society The Pros and Cons â€Å"On May 9, 1960, the Food and Drug Administration (FDA) approved the marketing of the first birth control pill in the United States. † The battle over birth control waged on long before F. D. A’s approval. Since its creation, arguments both pro and anti birth control have been immense. From religious beliefs to freedom of choice, both sides still have yet to find a middle ground on this matter. Whether negative or positive, birth control has had a tremendous impact on American society with no compromise in sight.The pro birth control side believes we must know in the war of birth control what exactly we are fighting for, teens are going to have to sex before marriage regardless, and parents have to do what they can to minimize the effects of it. According to one thinker, â€Å"The first step in determining the dispense of birth control is acknowledging the frequency of non-marital sex, and willingness to consider its consequences. † Backed by Susan Jacoby studies, indicating that the percent of the population having sex by the age of 21 rose from 40% to 70% were for the entire population.Today, 77% of men and women will have had sex, including 75% who will have had premarital sex, by the age of 20. Consequently, 95% of the entire population will have had sex outside of marriage by the age of 44, and they will overwhelmingly have done so with someone other than a person they will eventually marry (Jacoby). Naomi Cahn, a professor from George Washington University Law School once stated, â€Å" The war for non-premarital sex was lost long ago, we’re now combatting the results of the loss with our main weapon being birth control. Once conceding defeat, the belief is that parents can neutralize the consequences of teens having sex by giving them birth control. On the other hand the anti birth control side; tends to believe by parents giving birth control to teens, they ar e in fact promoting teen promiscuity. According to research done by Richard John Neuhaus commenting on giving birth control to kids, â€Å"To do so would be to try something that possibly no society has tried before: to state publicly that there are no social standards or sanctions with respect to the sexual activity of young people.Giving teens birth control would be parents way of saying, I expect you to have sexual intercourse with out verbally saying it. This would make it appear to be normal, thus by virtue lending a helping hand in teens having sexual intercourse (Neuhaus). Feeling dispense of such devices would led to lower standards in American society is more harmful then beneficent. Most people who are pro choice refute the notion of more harm done then good in usage. Joyce Arthur an activist for birth control was a part of several studies conducted in the U. S.Joyce cited â€Å"The consequences of mothers and fathers parenting children they did not want to bear resulted in damages both to the children and parents. † The children were significantly more likely to have mental handicaps, they performed significantly worse academically and were twice as likely to have a record of juvenile delinquency according to Dr. Jeffrey Peipert of Washington University in St. Louis in a study published. Activist states not only are we putting our future in jeopardy by denying them birth control, but we are also damaging our young teens.Teens whom had to bear unwanted children have shown consistent patterns of anti-social behavior and neglect by their own parents. Joyce argues â€Å"These issues are more detrimental than the marginal increase in sexual activity amongst teens. † Thus parents giving birth control devices to teens help society more according to Joyce Arthur. Many of those against birth control believe we cannot foresee the full impact of parents actively giving out birth control. According to Douglas J. Besharov,† Parents actively pushing birth control to teens ought to be aware of the possible increase in sexually transmitted diseases (STD).Citing a vast number or birth control devices protect against pregnancy but aren’t efficient at fighting the diseases. Besharov stated, â€Å"If only can we have our parents weigh the unwanted birth of a child, to the lost of a child to an S. T. D, they may see the lesser of two evils in promoting birth control. No method outside of condoms has proven to offer any protection from a S. T. D. Besharov asks, â€Å"Are we so concerned with unwanted births that we’d disregard the health of the living? † The debate on whether we should or should not give birth control to teens as gone on for years and will continue on for the foreseeable future. Both sides have made very valuable and valid points. There is no right or wrong answer it just a matter of beliefs and preferences. The only answer lies with in the person, if one chooses to have sex, with out ques tion birth control should be readily available to them, to protect themselves from consequences. However, if there is any error at all in these debates it would be the notion that we should assume that all our teens are having sex.With this assumption for us to actively push birth control could indeed send the wrong message. For those who aren’t actively having sex it could be due to the fact that they don’t have their hands on birth control devices and by us giving it to them we could also be giving them the green light to have sex. Works Cited Bartells, F. K. â€Å"Teens Should Not Have Access to Emergency Contraception Without Parental Consent. † Birth Control. Ed. Margaret Haerens and Lynn M. Zott. Detroit: Greenhaven Press, 2012. Opposing Viewpoints. Rpt. rom â€Å"The New ‘Emergency Contraception': A Dark and Deadly Pill. † 2010. Gale Opposing Viewpoints In Context. Web. 24 Oct. 2012. Cahn, Naomi, and June Carbone. â€Å"Birth Control Asserts Feminist Values and Is Socially Beneficial. † Birth Control. Ed. Margaret Haerens and Lynn M. Zott. Detroit: Greenhaven Press, 2012. Opposing Viewpoints. Rpt. from â€Å"Contraception: Securing Feminism's Promise. † The George Washington University Law School Public Law and Legal Theory Working Paper. Vol. 476. 2009. Gale Opposing Viewpoints In Context. Web. 4 Oct. 2012 Neuhaus, Richard John. â€Å"Long-Term Contraceptive Devices Promote Teen Promiscuity. † Teens at Risk. Ed. Auriana Ojeda. San Diego: Greenhaven Press, 1999. Opposing Viewpoints. Gale Opposing Viewpoints In Context. Web. 24 Oct. 2012. Parenthood, Planned. â€Å"Teen Access to Abortion Should Not Be Restricted. â€Å"The Abortion Controversy. Ed. Emma Bernay. Detroit: Greenhaven Press, 2007. Current Controversies. Rpt. from â€Å"Child Custody Protection Act: Hearings on H. R. 1218. † 1999. Gale Opposing Viewpoints In Context. Web. 24 Oct. 2012.