Development and Validation of Performance Prediction Models and Specifications for Asphalt Binders and Paving Mixes Essay Example

Development and Validation of Performance Prediction Models and Specifications for Asphalt Binders and Paving Mixes Essay Development and Validation of Performance Prediction Models and Specifications for Asphalt Binders and Paving Mixes Dr. Robert L. Lytton Dr. Jacob Uzan Dr. Emmanuel G. Femando Texas Transportation Institute Texas AM University College Station, Texas Dr. Reynaldo Roque Dr. Dennis Hiltunen Dr. Shelley M. Stoffels Pennsylvania Transportation Institute Pennsylvania State University University Park, Pennsylvania .r_rrD Strategic Highway Research Program National Research Council Washington, DC 1993 SHRP-A-357 ISBN 0-309-05617-9 Contract A-005 Product No. 012 Program Manager: Edward Harrigan Project Manager: Harold Von Quintus Production Editor: Cara J. Tate Program Area Secretary: Juliet Narsiah October 1993 key words: calibration crack initiation crack propagation creep compliance elastic fatigue cracking fracture mechanics fracture toughness laboratory testing of asphalt concrete material properties mechanics microcracks pattern search method pavement performance prediction plastic resi lient dilatancy resilient properties rutting system identification method thermal cracking validation vermeer plastic properties viscoelastic viscoplasticStrategic Highway Research Program National Academy of Sciences 2101 Constitution Avenue N. W. Washington, DC 20418 (202) 334-3774 The publication of this report does not necessarily indicate approval or endorsement of the findings, opinions, conclusions, or recommendations either inferred or specifically expressed herein by the National Academy of Sciences, the United States Government, or the American Association of State Highway and Transportation Officials or its member states.  © 1993 National Academy of Sciences 1. 5M/NAP/1093 Acknowledgments The research described herein was supported by the Strategic Highway Research Program (SHRP).SHRP is a unit of the National Research Council that was authorized by section 128 of the Surface Transportation and Uniform Relocation Assistance Act of 1987. In a project as extensive and dem anding as the SHRP A-005 project, the utmost efforts were called for and received from the project staff. Of particular note are the contributions of W. W. Crockford, Ming-Lou Liu, T. Freeman, C. K. Estakhri, Fuming Wang, C. H. Michalak, J. N. Galey, N. Stubbs, O. J. Pendleton, M. Chau, C. E. Schlieker, S. Phillips, and S. Cain with the Texas Transportation Institute (TTI) team.TTI secretarial services were provided by B. Cullen, C. Bryan, G. Fattorini, and S. Pierce. Noteworthy contributors from the Pennsylvania Transportation Institute team were S. Arnold, M. G. Sharma, W. Butlar, T. Farwana, N. Kim, K. Knechtel, W. Lauritzen, S. Reddy, P. Romero, N. Tabatabaee, and V. Tandon. SHRP technical staff who provided valuable assistance were H. Von Quintus and R. Leahy. ..  ° 111 Abstract The objectives of SHRPs asphalt research were: to extend the life or reduce the life cycle costs of asphalt pavements; to reduce maintenance costs; and to minimize the number of premature failures.An important result of this research effort is the development of performance-based specifications for asphalt binders and mixtures to control three distress modes: rutting, fatigue cracking and thermal cracking. The SHRP A-005 project developed detailed pavement performance models to support these binder and mixture specifications and performance-based mixture designs. This report documents the findings of this extensive research effort and provides supporting data for the performance-based specifications and mixture design procedure called SUPERPAVE TM.SHRP Contracts A-002A (Binder Characterization and Evaluation) and A-003A (Performance-Related Testing and Measuring of Asphalt-Aggregate Interactions and Mixtures) accomplished three goals: 1) to identify relationships between asphalt binder properties and field performance; 2) to develop models for the estimation of pavement distress based the physicochemical properties of the asphalt binder; and 3) to produce test methods to measure these pavement performance factors. The final validation of these relationships, test methods and findings is the focus of long-term, controlled field experiments (Specific Pavement Studies[SPS]-9).This validation approach requires 10 or more years of investigation and observations, which is inconsistent with SHRPs objective to rapidly develop performance-based specifications. The validation process was accelerated by the SHRP A-005 contract, which developed and used a sophisticated, mechanistic-based pavement performance model to define the relationships between asphalt binder and mixture properties and pavement distress. The objectives of the SHRP A-005 Contract are as follows: 1. stablish, on the basis of documented field performance data, criteria that may be used in support of the asphalt binder specification and for the design of asphaltaggregate mixture systems develop performance prediction models for asphalt binder and for asphaltaggregate mixture systems 2. V A comprehens ive pavement of fatigue cracking, thermal time, using results from the environmental data and can (combination of binder and performance model was developed that predicts the amount cracking and rutting in asphalt concrete pavements with accelerated laboratory tests.The model uses detailed be used to determine the optimal mixture design aggregates) for specific conditions. The pavement performance models for each distress were also used to confirm the relevant binder and mixture properties established by other SHRP contractors using accelerated laboratory tests and laboratory torture tests; and to establish the degree of correlation between those asphalt binder and mixture properties. Results from these model studies were used to confirm or make recommendations for revisions to the asphalt binder specification.In general, these analytical studies confirmed the material properties and specific limits used in the performance based specification. The model is simple, runs on a microcom puter, and can be used to evaluate or design asphalt concrete mixtures. The model can minimize a specific distress or combinations of different distresses, or it can set specification limits for specific materials and environments. The model has three parts: 1) a mixture evaluation model, 2) a pavement response model, and 3) a pavement distress model. The mixture evaluation program calculates the relevant binder and mix properties from the accelerated laboratory tests.These properties are used with the pavement response program to evaluate the behavior of a mixture subjected to traffic and/or environmental loads. This mixture evaluation program calculates the non-linear elastic, viscoelastic, plastic and fracture properties of a mixture. The pavement response program calculates the stresses and strains in an asphalt-aggregate system from applied wheel loads and temperature changes. The pavement distress program uses the relevant mixture properties and the appropriate stresses and st rains to calculate the amount of cracking (from wheel loads and environmental loads) and rutting with time. i Executive Summary The objectives of SHRPs asphalt research were: to extend the life or reduce the life cycle costs of asphalt pavements; to reduce maintenance costs; and to minimize the number of premature failures. An important result of this research effort is the development of performance-based specifications for asphalt binders and mixtures to control three distress modes: rutting, fatigue cracking and thermal cracking. The SHRP A-005 project developed detailed pavement performance models to support these binder and mixture specifications and performance-based mixture designs.This report documents the findings of this extensive research effort and provides supporting data for the performance-based specifications and mixture design procedure called SUPERPAVE TM. The objectives of the SHRP A-005 Contract are as follows: 1. establish, on the basis of documented field perfo rmance data, criteria that may be used in support of the asphalt binder specification and for the design of asphaltaggregate mixture systems develop performance prediction aggregate mixture systems models for asphalt binder and for asphalt- 2.The successful development of performance-based specifications required the validation of those properties identified as important determinants of pavement performance. This validation effort is a three-stage process. The first two stages were completed under SHRP. The third or final stage will be directed by the FHWA through the SPS-9 projects of the ongoing Long-Term Pavement Performance (LTPP) program. The first stage of the validation effort was accomplished through the use of accelerated laboratory tests by the SHRP A-003A contract.The second stage was accomplished by the SHRP A-005 contract through the use of field performance data. This second stage established the degree of correlation between the field observations of distress and: 1. 2. those asphalt binder properties shown to significantly affect the performancerelated characteristics of asphalt-aggregate mixtures performance-related material properties of asphalt-aggregate mixtures Furthermore, the second stage validation effort provided the experimental results needed to set the specification limits for the relevant binder and mixture properties selected to vii ontrol pavement distress. These experimental results were also used to estimate the accuracy of the accelerated laboratory test methods employed to measure the relevant properties. This second stage validation effort relied heavily on the sampling and testing of asphalt-aggregate mixtures from the LTPP General Pavement Study (GPS) sections. A comprehensive pavement of fatigue cracking, thermal time, using results from the environmental data and can (combination of binder and performance model was developed that predicts the amount cracking and rutting in asphalt concrete pavements with accelerated labo ratory tests.The model uses detailed be used to determine the optimal mixture design aggregates) for specific conditions. The pavement performance models for each distress were also used to confirm the relevant binder and mixture properties established by other SHRP contractors using accelerated laboratory tests and laboratory torture tests; and to establish the degree of correlation between those asphalt binder and mixture properties. Results from these model studies were used to confirm or make recommendations for revisions to the asphalt binder specification.In general, these analytical studies confirmed the material properties and specific limitsused in the performance based specification. A brief list of the products from this research follows. Systems Identification Model The performance models are used to predict distresses or observations, such as cracking and rutting. The SID generates material properties for those models to minimize the error between the observed and predi cted pavement distress. Basically, the SID sets up a sensitivity matrix and solves for the required change when the change is larger than the prescribed acceptable value for convergence.This system was used in the calibration process for each of the pavement distresses, and to establish the specification limits for asphalt binders and mixtures. The SID can be extremely useful to mix designers and specification writers to theoretically establish limits for mixture properties under projectspecific conditions. It can also be used to update and revise the calibration coefficients of the pavement performance models. ? Micromechanics (MM) Model The micromechanics (MM) model is a system of material response equations for each material component used in asphalt concrete mixes.The model combines the measured response characteristics (in terms of creep-compliance) of the binder, mastic and aggregate to predict that same response of a combined mixture. This model will be useful to mix designer s to theoretically evaluate and initially optimize a mixture blend prior to any accelerated laboratory tests on that mix.  °Ã‚ °Ã‚ ° _III Pavement Distress Models A set of comprehensive models that predict the amount of fatigue cracking, rutting and thermal cracking with time are available.Each of these models use results from the accelerated laboratory tests to calculate critical material properties of the mixture for the stresses and strains imposed on the mixture from applied wheel and environmental loads. These stresses and strains are then used to calculate each type of distress. Fatigue cracking is calculated in terms of square feet per unit area and is based on fracture mechanics methodology. Thermal cracks are calculated in terms of linear feet per unit length and used linear viscoelasticity to determine thermal stresses and fracture mechanics principles to estimate the amount of cracking with time.Rutting is calculated in terms of an average rut depth, based on a 4-ft str aight edge. The model uses the concept of a material elasto-plastic formulation to calculate the initial plastic deformation due to both shearing and volumetric stresses and uses the concept of strainhardening to calculate the total depth rutting within each different season. Binder Performance-Based Specification Binder performance-based specifications limits for thermal cracking were found based upon patterns of binder stiffness and log slope of the compliance as they affect the extent of cracking.No such patterns could be found to relate binder properties to the rate of appearance of load-related distress, leading to the conclusion that binder properties alone do not control the fatigue cracking or rutting performance of asphalt concrete. Instead, specifications for both the binder and mixture properties are necessary for quality assurance against load-related distress. The calibrated performance prediction models provide a sound and reliable means for such mixture specification limits.Binder properties alone also do not control thermal cracking and mixture tests must be performed to evaluate the thermal cracking performance of a particular mixture. Finally, it is important to note that all of the quantities used for specification limits are material properties that are defined as they are used in mechanics. Its efficiency and simplicity in descriptions of essential and sensitive material characteristics make the discipline of mechanics a very useful and practical framework, not only for predicting distress but for the development of specifications that are directly related to performanceMaterial Property Relationships of pavement materials have been used in Several new methods for the characterization the load-related performance model. †¢ The resilient properties of asphalt were found to be identical to those used to characterize the materials in the supporting layers. Poissons ratio was found to be stress dependent. A tension in the asphalt binder w as found to be acting between ix I the aggregate temperature. †¢ particles. Both of these effects were found to depend strongly uponThe plasticity parameters which characterize asphaltic concrete include two friction angles, a cohesion, and a volumetric component, all of which are also commonly used in soil mechanics to characterize base course and subgrade materials. †¢ The accumulation of plastic deformations due to repeated traffic loading was shown to be related to the plastic properties and to the slope of the log creep compliance curve of the asphalt mix. The fracture properties of asphalt concrete were found to apply to both the crack initiation and crack propagation phases of crack growth in viscoelastic materials was found to be applicable to asphalt concrete. Pavement Performance Models Models of permanent deformation and cracking damage were developed and calibrated to field observations of these distresses on pavement sites distributed across the United States and Canada. Calibration adjustments were made to the predictions by a mathematical technique known as the Systems Identification (SID) method or by a nonlinear pattern search method. The adjustments were made in seven material properties that represent the two phases of fatigue cracking and in one coefficient of the rut depth.The calibration adjustments were not large nor did they vary much from one climatic zone to another, indicating that the prediction models developed for both fatigue cracking and rutting are sound. The calibrated models take into account the traffic, the temperature variations in all layers throughout the year, and the consequent variations in the material properties of each pavement layer in computing the accumulations of rutting and cracking with the seasons. Even though the pavement predictions were calibrated in sets grouped into climatic zones, the performance predicted for each pavement matched the actual performance very well.Temperature and moisture com putations were made with the FHWA Integrated Model of Environmental Effects, this project which showned to be capable of reproducing field measurements very well. The calibrated load-related model was shown to be well suited for the development of performance-related specifications and for the SHRP mix design model SUPERPAVE TM. X Field Experiments GPS Sites An experiment design was adopted to provide a wide variety of climatic exposure and rates of appearance of rutting and fatigue cracking.Very detailed information was obtained for each pavement section to permit a fairly complete characterization of the material properties of each layer. Cores were taken and tested in a variety of temperatures, stress and strain states. Material properties derived from these were found to be comparable to elastic and viscoelastic properties backcalculated from nondestructive deflection tests made with a falling weight deflectometer. Dynamic analysis was performed on about half of the pavement se ctions to determine the viscoelastic and damped elastic characteristics of each layer.It was shown that this backcalculation can produce reasonable values of m, the slope of the log creep compliance curve of the asphalt surface layer. This slope has been found to be the most important single variable in predicting rutting, fatigue cracking, and thermal cracking. Thus, the ability to measure it nondestructively in the field is a research result of this project that is of primary importance. The FHWA Integrated Model of Environmental Effects was shown to be very accurate in predicting seasonal variations of layer temperature, moisture, and moduli.This model, and the pavement performance prediction model form the computational elements of the SHRP SUPERPAVE TM mix design system. Laboratory Testing of Asphalt Concrete Mixtures A method of taking and testing cores in a variety of test modes and stress states was developed in this project. Among other testing modes, the equipment can run monotonic, repeated, and frequency sweep tests in tension or compression with triaxial testing equipment. Tensile tests have been avoided customarily because the samples fail in the grips.In this project the difficulty was found to be alignment, which was cured with a high production rate gluing jig when this device was used and 98 percent of the samples tested to failure parted in the center of the sample and away from the loading heads. Simulation of traffic loading rates in the tests, would have required much more sophisticated equipment, both to load and to record accurately the response of the sample. Instead, the objective of each test described herein was to measure the material response under a steady applied load, in a sample where the stress and strain patterns were uniform.This permited an accurate determination of the material properties that were then be used to determine the response of the material to traffic loading rates. Use of a cylindrical sample, taken from a fi eld core, permited the application of a variety of triaxial stress states that allowed a determination of how the material properties depended upon the stress state. The sample was placed in a temperature-controlled chamber to permit testing at the full range of temperatures to which an asphalt concrete layer is subject in the field.A specially designed metal chamber allowed the sample to be tested under a wide variety of confining pressures. A pair of LVDTs measured the †¢ xi i lateral strain of the sample, which made possible a complete and accurate characterization of the elastic, plastic, viscoelastic, viscoplastic resilient, dilatant, strength, and fracture properties of a material. Overall, the coring and testing apparatus developed in this project is reliable, accurate, and relatively simple both to construct and to operate.The A-003A project developed methods to analyze the test data for the Accelerated Laboratory Tests to produce the viscoelastic, resilient and plastic ity properties needed as input to the load-related performance model. In the course of all of the test material characterization and performance prediction work performed in this project, it became clear how important it is to measure the lateral strain as well as the vertical strain in any sample of pavement material tested, whether it is asphalt concrete, base course or subgrade. Pavement Performance PredictionThe performance prediction models developed in this project are developed for use on microcomputers and have been incorporated into the SHRP SUPERPAVE TM mix design procedure. The use of plasticity characterization to predict rutting makes it possible to consider both vertical and lateral permanent deformation in all of the pavement layers. The prediction of fatigue cracking is separated into two processes: crack initiation and crack propagation. During crack initiation, distributed microcracks form, grow, densify, and coalesce under repeated loads. Healing is assumed to occ ur primarily in the crack initiation phase.During crack propagation, cracks grow outward from the tensile zone where the microcracks form. These cracks grow from small but visible flaws into fulldepth cracks of the asphalt layer primarily in the shearing propagation mode. The predictions made with this approach were found to be unusually accurate even before they were calibrated to match the field observations. The calibration process was used extensively in this project as a form of nonlinear regression analysis. It was employed in a variety of ways to reduce laboratory data as well as to bring predicted distress into close accordance with the field observations.Two powerful techniques were used which should find many practical uses in the pavement field in the future: the Systems Identification SID method, and the pattern search method. Both methods satisfy a least sum of squared errors criterion. Calibration is done in this program by finding multiplying factors for the most sens itive material properties. These were found by sensitivity analysis to be the stiffness of the asphalt concrete, its tensile strength, the log slope of the creep compliance curve, and the two healing coefficients.The calibration method has another unique use which was developed and demonstrated in this project. Once a performance model is calibrated, the same calibration process can be converted to determine minimum values of those material properties which are xii needed to meet prescribed distress target levels. This use of the performance prediction programs to assist in setting specification levels for material properties is very promising and deserves further exploration. Validation of Relations Between Material Properties nd Pavement Performance While it is evident that the properties of the asphalt binder are an important factor in the service life of asphalt concrete, the lack of observed patterns of high and low rates of rutting and fatigue cracking show plainly that the se lection of the binder alone will not assure good load-related performance. It is clear that the disciplines of pavement analysis, design, and mix design, and the effects of construction and weather, also play important roles in the development of load-related distress.The pavement performance prediction model represents several important advances in pavement analysis and design and in mix design through its use in SUPERPAVE TM. The micromechanics model of the properties of a mix which was developed in this project needs to be studied in detail for its potential benefits to an understanding of the important interactions of the constituents in mix design. Without such an understanding, setting specification limits on the properties of the binder will have little or no effect on the retardation of load-related distress. ThermalCracking were drawn regarding the effectiveness of new SHRP binder which are based on the results of the field validation studies The following conclusions and m ixture specifications presented in this report. †¢ The indirect tensile creep and failure test at low temperatures (ITLT), that was developed at PTI as part of this contract is clearly suitable to support the new SHRP mixture specification for the control of thermal cracking. Excellent correspondence was obtained between observed thermal cracking in the field and thermal cracking predicted by using properties determined from the ITLT.Use of the time-temperature superposition principle to determine the viscoelastic properties of asphalt mixtures, and determination of fracture parameters from viscoelastic properties and mixture strength, appear to be valid and suitable methods to determine the low temperature mixture properties needed for the control of thermal cracking. The parameters S and m (stiffness and m-value at 60-second loading time) determined from the bending beam rheometer tests appear to be suitable for evaluating the relative thermal cracking performance of asphalt binders.S and m correlated reasonably well with observed thermal cracking in the field. †¢ †¢ xiii †¢ The limits on S and 29,000 psi and m gt; in this investigation, 45,000 psi and m gt; m defined in version 7G of the binder specification (S lt; 0. 35) appear to be too restrictive. Based on the data obtained the following limits appear to be more appropriate: $ lt; 0. 30. thermal cracking effect on the thermal ITLT test must be a particular mixture. †¢ The binder specification alone does not guarantee adequate performance. Mixture characteristics may have a significant cracking performance of a particular binder.Therefore, the performed to evaluate the thermal cracking performance of Aging The aging studies led to the following conclusions: †¢ For the range of mixtures evaluated in this investigation, it appears that the thermal cracking performance of asphalt mixtures can be reasonably evaluated on the basis of only the properties of the mixture after long- term-aging (i. e. without accounting for the rate of age-hardening). It appears that long-term mixture aging (as defined by the SHRP A003-A contractor) is needed to properly evaluate the thermal cracking resistance of asphalt mixtures.This assumes that the long-term mixture aging procedure results in aging levels comparable to those observed in the field. Based on limited data, it appears that aging levels comparable to those observed in the field, as reflected by changes in the low temperature properties of the binder, can be attained through TFOT followed by PAV aging as proposed in the SHRP binder specification. The effectiveness of the long-term mixture aging procedure proposed by the SHRP A-003A contractor could not be evaluated because the laboratory mixing and compaction methods used in this investigation did not represent field mixture and compaction.Low temperature properties of laboratory-produced mixtures were very different than properties of field cores of the same mixt ure. †¢ †¢ †¢ Moisture Effects studies led to the following conclusions: The moisture †¢ Moisture changes within the asphalt mixture have a significant effect on fundamental low temperature properties of the mixture and on thermal cracking performance. xiv †¢ Low temperature properties for the evaluation of thermal cracking resistance of a mixture using the PTI thermal cracking model must be determined on a dry mixtures (i. e. ither laboratory-produced mixtures or field cores that have been thoroughly dried prior to testing). Use of properties determined at other moisture levels may result in significant errors in thermal cracking predictions and thus in evaluating the thermal cracking resistance of asphalt mixtures. For the range of mixtures evaluated in this investigation, it appears that the thermal cracking performance of asphalt mixtures can be reasonably evaluated on the basis of only the dry properties of the mixture (i. e. , without accounting for ef fects of moisture changes).

History Notes Essay Example

History Notes Essay Example History Notes Essay History Notes Essay How successful were the labour governments of 1964-1970 in fulfilling their promise to create a New Britain? During 1964 to 1970, The Labour government planned to create a ‘New Britain’ under the leadership of Harold Wilson. The most important successes of the Labour government include education, social freedoms and the freedoms of women. However, the most important failures of labour included its lack of the scientific minds in the party and its failure of large economic and technological advancement. Firstly, the Labour Government had hopes of reviving and advancing the technology in Britain.In their manifesto, Labour stated ‘We shall create a New Britain – mobilising the resources of technology. ’ This can be supported by their development of a Ministry of Technology and an attempt to base government on scientific principles. In which an emphasis was placed on planning, management and professionalism. Socially, there was an advance towards a more m obile, less class-ridden Britain. With the introduction of the Establishment of the Race Relations Board, which aimed to tackle racial discrimination and promote racial equality.Before the Wilson period, Britain was viewed as segregated, however Labour wanted to change this and integrate society more. A success shown by Labour during this period was the attempt to break down the old class barriers. ‘It was a very good time for the arts and many aspects of education, the Open University in particular. ’ This provides information which supports the idea that the Labour governments of 1964–1970 were a success in creating a new modern Britain. As well as the Open University, Labour’s other education policies included; the development of comprehensive schools and the expansion of higher education.Leading on from this, Labour was successful in building upon social freedoms as well. The establishment of the Ministry of Arts under Jennie Lee increased cultural opp ortunities. This provided funding for the Arts Council and British Film Institute. By doing this, they showed concern to broaden cultural opportunities for all. Furthermore, the Wilson years were in many ways seen as successful and creative. ‘It was an era of social and sexual freedom. ’ As Paul Johnson wrote after the 1970 election ‘We no longer terrorise homosexuals. We do not force mothers to bring forth unwanted children into the world.We do not murder by the rope’. This showed signs of liberalisation against; homosexuality, divorce, abortion and the end of hanging. Thus, supporting the view of the Labour Government trying to create a new modern society. On the other hand, it can be seen that the Labour government never lived up to its manifesto promise to create a New Britain. One of the major factors why Labour was unsuccessful was due to its economic failures. Labour had higher tax rates than the Conservative government and the unions wanted to stop the technological advances in industries.Conservative policies of ‘Rising incomes and lower taxes have made possible a spectacular increase in spending on the essentials’ for British people. Another economic problem that arose during this period was Labour’s slowness to bring about devaluation. Devaluation was when the issuing government had mandated that the price of the currency in foreign dollars is lower than it was before. This added to economic problems as a result of inflation remaining high at 12% between 1969–1970. The Labour Government did not succeed in changing the living conditions of the people. Under Conservative rule the living standards of the British people have improved more than in the whole of the previous half-century. ’ This is shown where over 98% of the working population have jobs that have caused the standard of living for people to increase. This differs from Labour’s ideals, where they focused more on social refor ms rather than improving beneficial changes in the country. In addition, Conservatives did not believe the ideas Labour was suggesting about creating a New Britain. Rather they deemed it to be a ‘camouflage aged return to dreary doctrines which have already proved a failure. Also, the doctrine showed no mention of moral issues, because leaders like Wilson and Brown were conservative on such issues. The Conservatives believed what they were offering was an extension of prosperity which their policies had been proven to achieve. In conclusion, the Labour Government did have some successes during this period in creating a New Britain, which was mainly due to the support they were given by the government. The development of a Ministry of Technology put an emphasis on planning, management and professionalism.And, developing education policies, which included the development of comprehensive schools and the expansion of higher education, meant a breakdown of social barriers. However , The Labour Government never fully achieved its successes in creating a New Britain. This was due to the failure of the economic policies such as Labour having higher taxes than the conservatives. And finally, the Conservative fears that implied Labour’s ‘New Britain’ would have meant a return to the ‘dreary’ and failed doctrines of the past Labour Governments.

Research report writing (Maintenance Management) Essay

Research report writing (Maintenance Management) - Essay Example The development intent aimed at enterprise creation for people within adjacent communities, a densely populated depressed area. The front most of five warehouses which stretches 200 meters corresponding to the highway was split in half to create roadway and traffic flow into the industrial block. Roadwork and open space completes 55% of the 22,365 square meter original warehouse footprint. One of the halves of the original warehouse, which has a floor area of 5, 804.5 square meters, is fit out as a bazaar of smaller stalls. Several corridors cut from road level through entrances 3 meters wide and 3 meters high. Along the perimeter there are a total of 19 direct exit points with a total linear opening of 54.3 meters, but this includes the number of back portion fire exits. The overall effect is practically a covered open space. Common in a number of historic facilities is the practice of natural ventilation systems, which over several alterations of the facility use, these built in systems are compromised. By contentious views on energy usage and environmental issues, natural ventilation resurfaced as a method increasingly attractive for reduced energy consumption and acceptable ecological print (Walker, 2010). In the conversion of Warehouse—1, the ventilation system was reviewed of less importance since there were no recorded technical complications of difficulty in this category for the past 25—year warehouse operation. While this review provoked green build possibilities, the idea of facility conversion insofar also compromised capital expenditure constraint or reinvestment conservatism. The design approach is an application of the displacement ventilation theory by exhaust suction treatment, which relies heavily on the natural air movement in the vicinity. It occurs that the industrial block has a constant cool breeze from tree hedges that outline each warehouse zone. That is, a natural ventilation system depends on pressure differences to

Sex trafficking Research Paper Example | Topics and Well Written Essays - 1250 words

Sex trafficking - Research Paper Example It involves traffickers detaining or transporting victims for commercial sexual exploitation as defined by Moser (222). To bring into perspective the prevalence and trends of this social vice in the 19th Century, this paper borrows from the novel Thousand Pieces of Gold by Ruthanne Lum McCunn who narrates the struggles of women to earn their dignity and respect in early America through the life story of a Chinese girl, Lalu Nathoy whose father referred to her as Thousand Pieces of Gold, just as the title of the novel. With the famine of 1871 in northern China, he sells off Lalu to a brothel and later to a slave merchant travelling to America. This was the turning point in the life of the young girl. This paper guides on this discussion on sex trafficking, giving leads on how victims get lured and evaluating possible solutions in the light of the findings. Socio-economic misgivings, particularly poverty and wrong perception of better lives in other countries propagate sex trafficking. In this early society, sex trafficking was widely spread across the board. Not even were children spared as Li, the sex trafficker in the novel, traffics children together with her other victims. This comes to light when she quarrels Lalu for not getting the fraudulent customs clearing procedures right, claiming that â€Å"Even children: some of them are only ten, eleven years old. Children† were much better than she was (Gold 95). The cultural beliefs treated women as objects meant for the pleasure of men, while men were exalted as the only gender that had the right to work for a living. This therefore meant that women could be used in whichever way men would find pleasurable to them. Comparably, Moser (226) cites the US Department of Health and Human Services documenting sex trafficking as the second largest and fastest criminal industry worldwide. Women and children still comprise the majority of victims at about 80%, with two million children estimated to be in the comme rcial sex trade. Borrowing statistics from the United Nations, the researcher further estimates the market value for this crime at over $32 billion. Before the year 2000, sex trafficking was not prosecuted as a crime in itself but under other crimes such as promotion of prostitution. This exhibits the society’s clinging onto ancient belief of men as the superior gender. Just as Gold observed that a woman was not to â€Å"work like a man† so as to look appealing for marriage in the early days, the society still does not appreciate a woman as a laborer (356). Having pointed out that sex trafficking still remains rampant in the modern society as was in the 19th Century, it would be critical to understand how the vulnerable groups find themselves as victims of this crime. Deception, as put by Walters and Davis (1) stands out as a leading approach in luring victims of sex trafficking. The novel tells of Li, the trafficker, who took advantage of the naive American dream that Lalu had to lure her into her trap. Using America as a destination for her victims

Ethics Essay Example | Topics and Well Written Essays - 1500 words

Ethics - Essay Example This is particularly true when it comes to fellow professionals or protecting the reputation of our particular field. While â€Å"whistleblowers† are praised for their courage and integrity, the personal cost of â€Å"doing the right thing† can mean death to a career. Such behavior can also seriously affect the career of fellow professionals. A good example of the problems involved in balancing ones duty to fellow professionals and doing the right thing when one sees something wrong is clearly laid out by Michael Davis in Thinking Like an Engineer: Studies in the Ethics of a Profession. Davis outlines events leading up to the now infamous Challenger disaster brought on by certain engineering decisions regarding the questionable safety of ORings (4 Codes and Ethics of the Challenger, p 43-44). In reading the account the â€Å"blame† seems to fall upon one man, Robert Lund, vice president of engineering at Morton Thiokol, manufacturer of faulty ORings which were blamed for the tragedy. A team of engineers had recommended the flight be scraped, but Lund, with pressure from various people at the Space Center, was persuaded to allow the project to go forward. Space Center officials were â€Å"appalled at the evidence on which the no-launch recommendation was based.† (p44). Lund was in a professional bind. Should he take the advice of fellow engineers at Thiokol, or go with the recommendation of officials at the Space Center most of them engineers, to go forward. There was a lot of money at stake for Thiokol, and Lund knew it. The reputations of engineers were also at stake. He had to choose between duty to fellow professionals and pressure from outsiders to â€Å"think like a manager.† (p44) He chose the latter to disastrous results. It is easy as a professional to judge Lund’s decision in hindsight. Should he have blown the whistle then? Did he even think it necessary?

Analysis of Conceptual Frameworks in Accounting

Analysis of Conceptual Frameworks in Accounting Introduction International Accounting Standards Board (IASB) has begun a mutual project with US Financial Accounting Standards Board (FASB) to rebuild the existing frameworks and converge them into a common framework. First, some background. The US Securities and Exchange Commission (SEC) has proposed that companies required to file financial statements with the SEC begin replacing U.S General Accepted Accounting Principles (US GAAP) with International Financial Reporting Standards (IFRS) beginning in 2014. For all practical purposes this means the eventual adoption of IFRS (principles-based) for all companies in the United States (U.S. accounting standards are considered to be rule-based model). The shift aims to harmonize US accounting standards to an international one in tandem with the globalization of capital markets.Norwalk agreement between the FASB and the IASB was signed paving the way for the creation of more principles-based accounting standards for global financial reporting (Wikipedi a, 2010). What is  a Conceptual Framework? International Conceptual Framework of Financial Reporting is a system of interactive objectives and fundamentals which lays out a set of consistent standards in preparing financial reports.A conceptual framework is akin to a constitution that prescribes the nature, function and limits of financial accounting and financial statements. Why is a conceptual framework necessary? First, to be useful, standard setting shouldbuild on and relate to an established body of concepts and objectives. A soundly developed conceptual framework should enable the IASB or FASB to issue more useful and consistent standards over time. A coherent set of standards and rules should be theresult, because they would be built upon the same foundation. The framework should increase financial statement users understanding of and confidence in financial reporting, and it should enhance comparability among companies financial statements. Second, new and emerging practical problems should be more quickly solved byreference to an existing framework of basic theory. For example, PandaCorporation sold two issues of bonds that it would redeem either with $1,000 in cash or with 50 ounces of silver, whichever was worth more at maturity. Both bond issues had a stated interest rate of 9 percent. At what amounts should the bondshave been recorded by Pand a or the buyers of the bonds? What is the amount ofpremium or discount on the bonds and how should it be amortized, if the bond redemptionpayments are to be made in silver (the future value of which was unknownat the date of issuance)?It is difficult, if not impossible, for the FASB or IASB to prescribe the proper accountingtreatment quickly for situations like this. Practising accountants, however, must resolvesuch problems on a day-to-day basis. Through the exercise of good judgment and withthe help of a universally-accepted conceptual framework, practitioners can dismiss certainalternatives quickly and then focus on an acceptable treatment. Harmonization of accounting standards is very important. For instance, Multinational companies doing business in more than one country will find that it is difficult to comply with more than one set of accounting standards established by authorities in different nations. Harmonization of accounting standards will help the world economy in the following ways: by facilitating international transactions and minimizing exchange costs by providing increasingly perfect information; by standardizing information to world-wide economic policy-makers; by improving financial markets information; and by improving government accountability. International investment decisions and financial-based management decisions are then made with less risk. Furthermore, harmonization of accounting policy would help provide a level playing field globally. Regulators and auditors will be receiving the same information, facilitating the evaluation process. In todays accounting environment, there are two formats of accounting systems, namely principles-based system and rules-based system.Almost all companies are required to prepare their financial statements according to one of the two standards. Recently, there has been much debate on whether principle-based accounting would be more efficient than the popular rules-based accounting, in the wake of accounting scandals, such as Enron. As a result of the Enron saga, the current way of accounting has been come under a great deal of scrutiny. Rules-based Accounting Rules-based accounting such as US GAAP is basically a list of detailed rules that must be followed when preparing financial statements. Many accountants favor the prospect of using rules-based standards, because in the absence of rules they could be brought to court if their judgments of the financial statements were incorrect. When there are strict rules that need to be adhered to, the possibility of lawsuits is diminished (Investopedia, 2009). Having a set of rules can increase accuracy and reduce the ambiguity that can trigger aggressive reporting decisions by management. The matrix of rules, however, can cause unnecessary complexity in the preparation of financial statement Principles-based Accounting Principles-based accounting such asIFRS is adopted as a conceptual basis for accountants. A simple set of key objectives are set out to ensure good reporting, e.g. qualitative characteristics, faithful representation. Common examples are provided as guidelines and explain the objectives. Although some rules are unavoidable, the guidelines are not meant to be used for every situation (Investopedia, 2009). Precise requirements can sometimes compel managers to manipulate the statements to fit what is compulsory. The problem with principles-based accounting is that lack of guidelines can yield unreliable and inconsistent information that makes it difficult to compare one organization with another. When contemplating which accounting method is best, it must be made certain that the information provided in the financial statements is relevant, reliable and comparable across reporting periods and entities. Increased discussion has pushed accountants towards principle-based accounting, but it is recognized that the method needs to be modified to make it more effective and efficient. To illustrate thecomparison, for example, depreciation expense for all fixed assets is to be set at 10 percent per annum of the original cost of the asset until the asset is fully depreciated.Such a rule leaves no room for judgment or argument about the amount of depreciation expense to be recognized. Comparability and consistency across firms and through time is virtually assured under such a rule. This is a rules-based system.In contrast, under the principles-based system, depreciation expense for the reporting period should reflect the decline in the economic value of the asset over the period. Such a standard requires the application of judgment and evaluation by both managers and auditors. The goal is to register the realistic value of the asset according to as is basis. Differences between IFRS and U.S. GAAP Statement of Income Under IFRS, extraordinary items are not segregated in the income statement, while, under US GAAP, they are shown below the net income. Consolidation IFRS favors a control model whereas U.S. GAAP prefers a risks-and-rewards model. Some entities consolidated in accordance with FIN 46(R) may have to be shown separately under IFRS. Inventory Under IFRS, LIFO (Last In, First out) cannot be used while under U.S. GAAP,companies have the choice between LIFO and FIFO (First In, First Out). Using the LIFO method results in lower gross profit, which allows a company tobe taxed less. Earning-per-Share Under IFRS, the earning-per-share calculation does not average the individual interim period calculations, whereas under U.S. GAAP the computation averages the individual interim period incremental shares. Development Costs These costs can be capitalized under IFRS if certain criteria are met, while it is considered as expenses under U.S. GAAP(Remi Forgeas, 2008). Advantages Rules-based System Increased accuracy, reduced ambiguity and a diminished possibility of lawsuits. Rule-based standards are generally considered easier to audit for compliance purposes, and may produce more consistent and comparable financial reports across entities. Auditor display higher confident in decision making because they have a bright-light guidelines. Principles-based System The fundamental advantage of principles-based accounting is that its broad guidelines can be practical for a variety of circumstances Potentially very flexible with regard to new and changing products and environments. As such, they should also require less maintenance. Another advantage of a principles-based system is that it would result in simpler standards. Principles-based system would lead to standards that would be less than 12 pages long, instead of over 100 pages. Accountants are afforded the flexibility to input their expertise and judgment more freely in line with the professional code in producing the financial statements. Such deployment of their skills and experience will enhance their professionalism. Disadvantages Rules-based System Lack of transparency of disclosure. In the wake of recent accounting scandals, such as Enron and Worldcom, investors are becominghypersensitive to the reliability of published accounts and suspicious of the possibility of inflated earnings. The major drawback to a rules-based system is the complexity in the preparation of financial statements May include a lack of flexibility with regard to changing conditions and new products, hence requiring almost continual maintenance at times. Frequently subjectto manipulation as entities may search for loopholes that meet the literal wording of the standard but violate the intent of the standard. Principles-based System Critics of a principles-based approach argue that financial statements are more difficult to audit andwould likely lose their comparability and consistency across industries and issues regarding income measurement and recognition would remain controversial. For example, how much income will General Electric actually recognize on a multi-year defense contract under the percentage of completion method of accounting? Will this be comparable to the income reported by its competitors? To the extent that they rely on individual judgment to interpret and implement the standards, there is a danger that they can be used to manipulate financial results. For example, what ifthe auditors behaving badly? Abuse their trust and fail to apply the principles in good faith consistent with the intent and spirit of the standards. Auditors display less confidence in their decisions. Between the rules-based and principles-based modules, it is felt that the latter will be more practical and preferred by the global community, given its universal appeal based on ethics, sound judgment, transparency, credibility and even downright common sense factors. Moreover, in the globalised business arena, this system would be easier to adopt, comprehend and acceptable as against rigid rules that may be interpreted differently from one country to another. Example Cases Enron Case U.S. accounting standards are considered to be rule-based model. For example, we look at the Enron scandal, which broke in October 2001 and eventually led to the collapse of the Enron Corporation. Through the use of accounting loopholes, special purpose entities (SPE), and poor financial reporting, Enron was able to cover up billions of dollars in debt from failed deals and projects.In the U.S, Accounting law allows a company to exclude a SPE from its own financial statements if an independent party has control of the SPE, and if this independent party owns at least 3 percent of the SPE. Enron needed to find a way to hide the debt since high debt levels would lower the investment grade and trigger banks to recall lendings. Using the Enrons stock as collateral, the SPE, which was headed by the CFO Fastow, borrowed large sums of money. And this money wasused to balance Enrons overvalued contracts. Thus, the SPE enabled Enron to convert loans and assets burdened with debt obligations into income. In addition, the taking over by the SPE made Enron transfer more stock to SPE. However, the debt and assets purchased by the SPE, which was actually burdened with large amount of debts, were not reported on Enrons financial accounts. Enron was also guilty of using a dubious mark-to-market accounting system in its forward gas contract sales whereby income was estimated as the present value of net future cashflows to indicate true economic value. When these projects faltered, income was still recorded based on the initial value which of course was incorrect. As a result more projects had to be created to sustain a steady income inflow to appease the shareholders. Shareholders lost nearly $11 billion when Enrons stock price, which hit a high of US$90 per share in mid 2000, plummeted to less than $1 by the end of November 2001. Transmile case A special audit carried out by Moores Rowland Risk Management Sdn. Bhd, showed that Transmile made pre-tax losses of RM126 million and RM77 million for 2006 and 2005, respectively, instead of pre-tax profits of RM207 million and RM120 million as originally reported a total of RM530 million in overstatement. Their auditors Deloitte Touche declined to approve the accounts when the company failed to furnish them proof to substantiate certain trade receivables. However, the loss was not detected by Deloitte Touche. Worldcom case This case unveils how one of the worlds largest Mississippi telecommunicationproviders managed to make $3.8 billion disappear? The answer lies in the companys CFO Scott Sullivans treatment of capital expenditures and the accrual method, one of the basic principles of accounting.Sullivan, fraudulently took billions of dollars in operating expenses and spread them out across so-called property accounts, which is a type of capital expense accounts. This allowed Worldcom to charge the expenses off slowly, and in smaller amounts, instead of reporting them immediately to investors. The U.Ss rules-based accounting system is lack of transparency.Transparency is becoming a matter of survival rather than choice. The way toaddress at least some of the flaws mentioned above is to advocate more transparency in financial reporting. This essentially means that companies would start providing all the information the market considers to be relevant rather than simply fulfilling their mandatory regula tory requirements. Southern Bank Bhd (SBB) case In the review of Southern Bank Bhds audited financial statements for the year ended Dec 31, 2005 there was inappropriate accounting treatment amounting to RM 160 million as follows: Inappropriately valuing certain derivative financial instruments and not writing down in full the collateral value. Wrongly writing back specific provisions made on certain foreclosed properties. Capitalizing instead of expensing certain costs which is similar to Worldcom financial scandal. It appears that the accounting and auditing standard in Malaysia is very low. In order to protect the interest of the small investors and shareholders, the accounting and auditing standard should be upgraded. Conclusion Personally, I do not favor relying on either principles. Without credible principles, the rules are meaningless. Without rules the accountants are not protected. We had principle-based rules up until the IASB/FASB was created. The more specific rules or guidance were issued following lawsuits against auditors or accountants, questioning their professional judgment. The profession felt that to issue specific rules would reduce the likelihood of lawsuits against the accountants professional judgment. Interestingly, we are now coming full circle and looking to simplify how accounting is interpreted. We will make this switch and then in another 10-20 years, if another accounting scandal arises and everyone will ask for more rules again? However, we may be well served by acknowledging that neither a purely rules-based nor a purely principles-based system will be the best option on its own. Perhaps a largely principles-based system policed by a simple rules code could be the ideal solution.Any set of rules will be subject to someones interpretation. The rules will only be as good as those who use them. (2,490 words)

Parental Conflict In Turtle Mo :: essays research papers fc

The Parental Conflict in Turtle Moon   Ã‚  Ã‚  Ã‚  Ã‚  For the average person, occasional inter-personal conflicts are a fact of life. Nowhere do these conflicts manifest themselves with greater tension than in the parent-adolescent relationship. Through their works, writers of fiction illuminate the sources of strain common to parent-child interactions. In the novel Turtle Moon, Alice Hoffman exemplifies this conflict in the relationship between Keith Rosen and his mother Lucy. There are several factors that contribute to this conflict and the work as a whole. The strife between Keith and his mother results from Keith’s desire to live in New York with his father, the lack of parental involvement, and the lack of communication between Keith and his mother.   Ã‚  Ã‚  Ã‚  Ã‚  The discord between Keith and his mother results from his preference to live with his father in New York. Keith has no choice in the decision and now he lives in Verity, a town he hates. This situation lies at the root of his rebellion against his mother. When he lives in New York he is never particularly well behaved, â€Å"but after eight months in Florida, he is horrid†(5). Through his rebellious actions Keith generates grief and worry in his mother Lucy. His backpack must be checked â€Å"for contraband everyday†(31), and he and his mother fight constantly. Because he is forced to live with his mother, Keith resents her. Keith is angry with Lucy because he feels as if he is trapped in Verity. â€Å"He wanted to live with his father, but who asked him?†(6). Keith deliberately disobeys Lucy and has no respect for her. He counts down the days until he can go back to New York and this ignites many arguments between them. Keith’s rebelli ous actions advance the novel’s theme of searching for identity and independence. McBane In addition to living in Verity, another source of the conflict between Keith and Lucy is her lack of parental involvement. Lucy and Keith grow more and more distant from each other because Lucy stays out of Keith’s life. In the same way Keith avoids his mother at every available opportunity. â€Å"He waits in bed until he’s sure she’s left, so he won’t have to see her and pretend to be normal or cheerful or whatever it is she wants him to be†(6). Because Lucy does not involve herself in Keith’s life she wonders what he is doing and tends to assume the worst about him.