981 resultados para Materials de dret civil


Relevância:

30.00% 30.00%

Publicador:

Resumo:

This paper summarises recent investigations into characterisation and performance of unbound roadbase materials carried out by Main Roads, Queensland (QDMR), on road projects across the state. Performance based tests such as the Repeated Load Triaxial (RLT) and the Wheel Tracker (WT) are the primary tools which are increasingly used by QDMR to overcome the limitations of simple specification type tests. This paper shows the inadequacy of current specification tests to rank material performance. The performance based tests show that the properties of the coarse aggregate alone are inadequate for sound performance; enable the contribution to mechanical behaviour by plastic fines with high matric suction to be assessed,- further, and facilitates ranking of material behaviour. Simple shakedown analyses undertaken yield similar material rankings. Finally, some materials from the performance based characterisation are compared with Falling Weight Deflectometer (FWD) in-service pavement performance data.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The civil jury has been under attack in recent years for being unreliable and incompetent. Considering the myriad causes for poor civil juror decision-making, the current investigation explores both procedural and evidentiary issues that impact juror's decisions. Specifically, the first phase of this dissertation examines how jurors (mis)use evidence pertaining to the litigants when determining liability and awarding damages. After investigating how jurors utilize evidence, the focus shifts to exploring the utility of procedural reforms designed to improve decision-making (specifically revising the instructions on the laws in the case and bifurcating the damage phases of the trial). Using the results from the first two phases of the research, the final study involves manipulating pieces of evidence related to the litigants while exploring the effects that revising the judicial instructions have on the utilization of evidence in particular and on decision-making in general. ^ This dissertation was run on-line, allowing participants to access the study materials at their convenience. After giving consent, participants read the scenario of a fictitious product liability case with the litigant manipulations incorporated into the summary. Participants answered several attitudinal, case-specific, and comprehension questions, and were instructed to find in favor of one side and award any damages they felt warranted. Exploratory factor analyses, Probit and linear regressions, and path analyses were used to analyze the data (M-plus and SPSS were the software packages used to conduct the analyses). Results indicated that misuse of evidence was fairly frequent, though the mock jurors also utilized evidence appropriately. Although the results did not support bifurcation as a viable procedural reform, revising the judicial instructions did significantly increase comprehension rates. Trends in the data suggested that better decision-making occurred when the revised instructions were used, thus providing empirical support for this procedural reform as a means of improving civil jury decision-making. Implications for actual trials and attorneys are discussed. ^

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Advances in multiscale material modeling of structural concrete have created an upsurge of interest in the accurate evaluation of mechanical properties and volume fractions of its nano constituents. The task is accomplished by analyzing the response of a material to indentation, obtained as an outcome of a nanoindentation experiment, using a procedure called the Oliver and Pharr (OP) method. Despite its widespread use, the accuracy of this method is often questioned when it is applied to the data from heterogeneous materials or from the materials that show pile-up and sink-in during indentation, which necessitates the development of an alternative method. ^ In this study, a model is developed within the framework defined by contact mechanics to compute the nanomechanical properties of a material from its indentation response. Unlike the OP method, indentation energies are employed in the form of dimensionless constants to evaluate model parameters. Analysis of the load-displacement data pertaining to a wide range of materials revealed that the energy constants may be used to determine the indenter tip bluntness, hardness and initial unloading stiffness of the material. The proposed model has two main advantages: (1) it does not require the computation of the contact area, a source of error in the existing method; and (2) it incorporates the effect of peak indentation load, dwelling period and indenter tip bluntness on the measured mechanical properties explicitly. ^ Indentation tests are also carried out on samples from cement paste to validate the energy based model developed herein by determining the elastic modulus and hardness of different phases of the paste. As a consequence, it has been found that the model computes the mechanical properties in close agreement with that obtained by the OP method; a discrepancy, though insignificant, is observed more in the case of C-S-H than in the anhydrous phase. Nevertheless, the proposed method is computationally efficient, and thus it is highly suitable when the grid indentation technique is required to be performed. In addition, several empirical relations are developed that are found to be crucial in understanding the nanomechanical behavior of cementitious materials.^

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Widespread damage to roofing materials (such as tiles and shingles) for low-rise buildings, even for weaker hurricanes, has raised concerns regarding design load provisions and construction practices. Currently the building codes used for designing low-rise building roofs are mainly based on testing results from building models which generally do not simulate the architectural features of roofing materials that may significantly influence the wind-induced pressures. Full-scale experimentation was conducted under high winds to investigate the effects of architectural details of high profile roof tiles and asphalt shingles on net pressures that are often responsible for damage to these roofing materials. Effects on the vulnerability of roofing materials were also studied. Different roof models with bare, tiled, and shingled roof decks were tested. Pressures acting on both top and bottom surfaces of the roofing materials were measured to understand their effects on the net uplift loading. The area-averaged peak pressure coefficients obtained from bare, tiled, and shingled roof decks were compared. In addition, a set of wind tunnel tests on a tiled roof deck model were conducted to verify the effects of tiles' cavity internal pressure. Both the full-scale and the wind tunnel test results showed that underside pressure of a roof tile could either aggravate or alleviate wind uplift on the tile based on its orientation on the roof with respect to the wind angle of attack. For shingles, the underside pressure could aggravate wind uplift if the shingle is located near the center of the roof deck. Bare deck modeling to estimate design wind uplift on shingled decks may be acceptable for most locations but not for field locations; it could underestimate the uplift on shingles by 30-60%. In addition, some initial quantification of the effects of roofing materials on wind uplift was performed by studying the wind uplift load ratio for tiled versus bare deck and shingled versus bare deck. Vulnerability curves, with and without considering the effects of tiles' cavity internal pressure, showed significant differences. Aerodynamic load provisions for low-rise buildings' roofs and their vulnerability can thus be more accurately evaluated by considering the effects of the roofing materials.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The use of composite materials for the construction industry has been the subject of numerous scientific papers in Brazil and in the world. One of the factors that motivate this quest is the housing deficit that countries especially the third world face. In Brazil this deficit reaches more than 6.5 million homes, around 12% of all US households . This paper presents a composite that was obtained from waste generated in processes for the production of granite and marble slabs, cement, gypsum, sand, crushed EPS and water. These wastes cause great damage to the environment and are thrown into landfi lls in bulk. The novelty of the work is in the combined study thermal, mechanical and acoustic composite obtained in real situation of rooms that are part of an experimental housing. Many blocks were made from cement compositions, plaster, foam, sand, marb le and / or granite, preliminary tests of mechanical and thermal resistance were made by choosing the most appropriate proportion. Will be given the manufacturing processes and assembly units 500 units 10 x 80 x 28 cm produced for the construction of an ex perimental home. We studied what kind of block and residue, marble or granite, made it more feasible for the intended purpose. The mechanical strength of the produced blocks were above 3.0 MPa. The thermal resistance of the blocks was confirmed by the maxi mum temperature difference between the inner and outer walls of rooms built around 8.0 ° C. The sound absorption for optimal room was around 31%. Demonstrated the feasibility of using the blocks manufactured with composite material proposed for construction.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

This study has as object eight state vocational schools located in Araguari, Araxá, Frutal, Ituiutaba, Monte Carmelo, Patos de Minas, Uberaba and Uberlândia, in Minas Gerais. The period analyzed comprises the years from 1965 to 1976, from the signature of the Agreement 512-11-610-042 beteween the Ministry of Education and Culture (MEC) and the American Agency for International Development (USAID), which started a series of other agreements, and actions ending up with the creation of the Expansion and Improvement of High Schools Program (Programa de Expansão e Melhoria do Ensino Médio - PREMEM) and, from this, the Vocational Schools. The upper limit of the study, 1976, was the year when these agreements, known as MEC/USAID agreements ceased. The Vocational Schools were characterized as vocation probing schools, directing the professional formation of the population in general, which would happen a posteriori, turning it shorter and more effective, since the labor market would demand, urgently, capable professionals for an expanding economy. The project of Vocational Schools had a national scope, and foresaw, for its unfolding, the complete substitution of State Schools for the new model, called “multi-curricula”. The theme Vocational schools was the object of my Master’s degree study, when I focused the State School Guiomar de Freitas Costa, in Uberlândia. That study raised questionings and concerns that resulted in the central problem of the thesis presented here: understanding the measure in which such schools integrated the country’s development project – mostly in the first half of the military rule – and to understand its structure, functionality and efficacyThe development of the study presented here, demanded the use of several sources: 1) specialized literature about the topics presented, i.e., the situation of national education in a temporal analysis, the political, economical and social context, research methodologies, the theory of human capital, vocational teaching, pedagogical trends and practices, agreements MEC-USAID and PREMEM; 2) national, state and county laws related to the discussion: laws of national education directives and basis, decrees and reports stating about the program of technical cooperation between Brazil and the United States of America, the Program of Expansion and Improvement of Teaching (PREMEM), formation of professors, establishment of Vocational Schools and educational planning; 3) documentation of school archives: books of minutes of Collegiate and of faculty and staff, registrar books with final scores, enrolment, visits of inspector, accounting books, punch clock records, student, professor and staff occurrences, inventory, class schedules, school year calendar, school rules, class reports, payment rolls, bills of sales, exchanged mail, personal documentation of professional personnel, documents of land acquisition, blueprints, manuals of PREMEM, didactic materials/resources used in classes, books available in the school library, structured evaluations for follow-up of school processes, pictures of events, texts prepared for special dates, and news from the official newspaper and, finally, 4) national and local press reports, especially from Folha de São Paulo, Correio de Araxá, Correio de Uberlândia and Lavoura e Comércio (Uberaba). The proposition of Vocational schools was conciliate theoretical and practical formation through an active education permeated by technological resources. The contact with knowledge and several practical activities under professional supervision, the student would identify the knowledge area that would interest him the most and his aptitude. This formation in primary school would make way for the vocation studies in high school, which became mandatory by the law 5.692/71, that reformed school education from the previous levels of elementary, middle high and high school. However, the multi-curricula proposal that would be spread to the other public schools in the country ended up succumbing to the model already established. From its ephemeral existence, maybe the Vocational Schools have not reached the more general goals in political, economic and social aspects; however, this study demonstrated that, for the people that, directly or indirectly, had contact with such schools, a legacy of vocational and quality teaching was made, so much so, that forty years after the end of that proposal, they are still remembered.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Acknowledgments The financial support of the part of this research by The Royal Society, The Royal Academy of Engineering and The Carnegie Trust for the Universities of Scotland is gratefully acknowledged.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Acknowledgments The financial support of the part of this research by The Royal Society, The Royal Academy of Engineering and The Carnegie Trust for the Universities of Scotland is gratefully acknowledged.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Peer reviewed

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The use of structural health monitoring of civil structures is ever expanding and by assessing the dynamical condition of structures, informed maintenance management can be conducted at both individual and network levels. With the continued growth of information age technology, the potential arises for smart monitoring systems to be integrated with civil infrastructure to provide efficient information on the condition of a structure. The focus of this thesis is the integration of smart technology with civil infrastructure for the purposes of structural health monitoring. The technology considered in this regard are devices based on energy harvesting materials. While there has been considerable focus on the development and optimisation of such devices using steady state loading conditions, their applications for civil infrastructure are less known. Although research is still in initial stages, studies into the uses associated with such applications are very promising. Through the use of the dynamical response of structures to a variety of loading conditions, the energy harvesting outputs from such devices is established and the potential power output determined. Through a power variance output approach, damage detection of deteriorating structures using the energy harvesting devices is investigated. Further applications of the integration of energy harvesting devices with civil infrastructure investigated by this research includes the use of the power output as a indicator for control. Four approaches are undertaken to determine the potential applications arising from integrating smart technology with civil infrastructure, namely • Theoretical analysis to determine the applications of energy harvesting devices for vibration based health monitoring of civil infrastructure. • Laboratory experimentation to verify the performance of different energy harvesting configurations for civil infrastructure applications. • Scaled model testing as a method to experimentally validate the integration of the energy harvesting devices with civil infrastructure. • Full scale deployment of energy harvesting device with a bridge structure. These four approaches validate the application of energy harvesting technology with civil infrastructure from a theoretical, experimental and practical perspective.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Philip Pullman, author of the His Dark Materials trilogy, has acquired an impressive critical reputation and acquired a favored role in British culture as a social commentator. This essay attempts to link the pleasures associated with the trilogy with the politics inscribed in them, and consider both in the context of Pullman’s role in the civil society. The essay suggests that The Northern Lights offers pleasures in fantastical and metaphysical possibilities, and social confederacies that potentially offset the affective privations of neoliberalism. These possibilities are set in the context of recent theories of the “enterprise society.” The essay draws attention to a number of discontinuities that unfold as the trilogy progresses, and suggests that these undermine the possibilities inherent in the first novel. These disconti - nuities throw the role of fantasy and alternative universes into question, and reveal the limitations of Pullman’s fiction. The essay considers the limit and scope of Pullman’s political vision, both as a function of his fiction and his public engagement with social issues, and suggests that he exemplifies Raymond Williams’s concept of “bourgeois dissent” in which political critique and a continuing investment in traditional institutions and class hierarchy can be mutually reinforcing.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Compaction control using lightweight deflectometers (LWD) is currently being evaluated in several states and countries and fully implemented for pavement construction quality assurance (QA) by a few. Broader implementation has been hampered by the lack of a widely recognized standard for interpreting the load and deflection data obtained during construction QA testing. More specifically, reliable and practical procedures are required for relating these measurements to the fundamental material property—modulus—used in pavement design. This study presents a unique set of data and analyses for three different LWDs on a large-scale controlled-condition experiment. Three 4.5x4.5 m2 test pits were designed and constructed at target moisture and density conditions simulating acceptable and unacceptable construction quality. LWD testing was performed on the constructed layers along with static plate loading testing, conventional nuclear gauge moisture-density testing, and non-nuclear gravimetric and volumetric water content measurements. Additional material was collected for routine and exploratory tests in the laboratory. These included grain size distributions, soil classification, moisture-density relations, resilient modulus testing at optimum and field conditions, and an advanced experiment of LWD testing on top of the Proctor compaction mold. This unique large-scale controlled-condition experiment provides an excellent high quality resource of data that can be used by future researchers to find a rigorous, theoretically sound, and straightforward technique for standardizing LWD determination of modulus and construction QA for unbound pavement materials.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

There is no agreement between experimental researchers whether the point where a granular material responds with a large change of stresses, strains or excess pore water pressure given a prescribed small input of some of the same variables defines a straight line or a curve in the stress space. This line, known as the instability line, may also vary in shape and position if the onset of instability is measured from drained or undrained triaxial tests. Failure of granular materials, which might be preceded by the onset of instability, is a subject that the geotechnical engineers have to deal with in the daily practice, and generally speaking it is associated to different phenomena observed not only in laboratory tests but also in the field. Examples of this are the liquefaction of loose sands subjected to undrained loading conditions and the diffuse instability under drained loading conditions. This research presents results of DEM simulations of undrained triaxial tests with the aim of studying the influence of stress history and relative density on the onset of instability in granular materials. Micro-mechanical analysis including the evolution of coordination numbers and fabric tensors is performed aiming to gain further insight on the particle-scale interactions that underlie the occurrence of this instability. In addition to provide a greater understanding, the results presented here may be useful as input for macro-scale constitutive models that enable the prediction of the onset of instability in boundary value problems.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

This paper presents the results of 3D DEM simulations of granular materials subject to cyclic loading. While both the drained and undrained conditions are considered, the effects of depositional history and consolidation stress history on the stress-strain response are specifically evaluated. It is demonstrated that the different stress histories have a significant effect on soil response and that such effects can be attributed to differences in the initial particle arrangement (fabric).