40,460 research outputs found

    Formulation development and microstructure analysis of a polymer modified bitumen emulsion road surfacing : a thesis presented in partial fulfilment of the requirements for the degree of Master of Technology in Product Development at Massey University, Palmerston North, New Zealand

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    The purpose of this research was to develop a formulation for a polymer modified bitumen emulsion road surfacing product called microsurfacing to a mid-scale prototype stage. A supplementary part of the development was to investigate the polymer-bitumen interactions and how they affected the products end properties using confocal microscopy. The formulation development consisted of three stages: technical design specifications, initial design, detailed design. The technical specification was developed to define the product performance in quantitative measures, and set the initial formulation parameters to work within. The initial design development screened three polymers, four methods of adding polymer to the emulsion and two grades of bitumen. Experimental design techniques were used to determine the best polymer-bitumen combination and emulsion process method. Further experimental investigations consisted of screening three emulsifiers and assessing the effect of aggregate cleanliness on the surfacing abrasion and curing rate. The detailed design used experimental factorial design to examine the effects of polymer concentration, emulsifier level, and emulsifier pH on the emulsion stability, microsurfacing wear resistance and cure rate. The emulsion residue was observed using confocal microscopy with fluorescence light and the microsurfacing mixture using both fluorescent and reflected light. The research showed that a emulsion using 100 penetration grade Safaniya bitumen with SBR latex polymer post added could provide microsurfacing abrasion resistance of less than 100 g/m 2 ; an improvement of 85% on the minimum specification. The vertical permanent deformation was less than the 10% and could not be attained without polymer addition. The use of aggregate with a high cleanliness and an alkyl amidoamine emulsifier resulted in surfacing cohesion development of 20 kg-cm within 90 minutes, which compares closely to the international specification. Unexpected results not reported before were that the emulsion residue from biphase modified emulsions had a softening point up to 10°C higher than polymer modified hot bitumen with the same polymer concentration. The biphase emulsified binder residue also has a very different microstructure to hot modified bitumen and this structure has been proposed to help account for the improved resistance to high temperature and applied stress. Modifications to the formulation are to improve the emulsion settlement and should focus on the density difference between the bitumen and polymer latex. This research has shown that a microsurfacing reading product can be successfully formulated with New Zealand bitumen and aggregate sources to meet key specified performance requirements. By systematically investigating the effects of materials on the performance properties of the product, a formulation ready for a mid-scale experiment has been proposed

    Alaska Correctional Requirements: A Forecast of Prison Population through the Year 2000

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    This report is part of the Fire Island Prison Feasibility Study, a project conducted jointly by the School of Justice and School of Engineering at University of Alaska, Anchorage under contract to the Alaska Department of Corrections. The project undertook to assess the feasibility of locating a correctional facility on a 4,240 acre tract of land on Fire Island, which lies in Upper Cook Inlet about three miles off Point Campbell within the Municipality of Anchorage. The project was divided into three major phases: (1) an assessment of future bed space needs of the Alaska Department of Corrections; (2) an evaluation of the physical site and cost estimates for prison construction and operation; and (3) a public opinion survey and open discussion.The growth of the Alaska prison inmate population over the past fifteen years has been substantial. According to available statistics there were 482 institutionalized adult prisoners under control of the Alaska Division of Corrections in January 1971; by January 1980 this population had increased to 770 inmates; and between 1980 and 1985, the number of Alaska inmates almost tripled, rising from 770 to 2,073. Accurate forecasts of the future size and makeup of the prison population are needed as a basis for long-range programs and capital planning. This report presents long and short-term forecasts of the Alaska incarcerated prisoner population and bedspace needs of the Alaska Department of Corrections through the year 2000. The forecasts were developed by taking into consideration historical facts and status quo assumptions. Attention is also given to the impact of the 1980 Alaska criminal code revision on unsentenced and sentenced populations. The forecast derived from this study provides evidence of the need for additional institutional capacity in Southcentral Alaska by 1990. Planning should proceed for a capacity of 1,000 beds to be available for use by 1990.Alaska Department of CorrectionsAcknowledgments / Summary of Study / I. Introduction / II. Long-Range Forecasts / III. Short-Range Forecasts / IV. Regional Forecasts / V. Conclusions / APPENDICES / A. Inmate Population Forecasting: Statistical Model / B. JUSSIM Forecasting Model / C. Bibliography of Inmate Population Forecastin

    Gphpen and Colour Postscript

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    Threshold qq-voter model

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    We introduce the threshold qq-voter opinion dynamics where an agent, facing a binary choice, can change its mind when at least q0q_0 amongst qq neighbors share the opposite opinion. Otherwise, the agent can still change its mind with a certain probability ε\varepsilon. This threshold dynamics contemplates the possibility of persuasion by an influence group even when there is not full agreement among its members. In fact, individuals can follow their peers not only when there is unanimity (q0=qq_0=q) in the lobby group, as assumed in the qq-voter model, but, depending on the circumstances, also when there is simple majority (q0>q/2q_0>q/2), Byzantine consensus (q0>2q/3q_0>2q/3), or any minimal number q0q_0 amongst qq. This realistic threshold gives place to emerging collective states and phase transitions which are not observed in the standard qq-voter. The threshold q0q_0, together with the stochasticity introduced by ε\varepsilon, yields a phenomenology that mimics as particular cases the qq-voter with stochastic drivings such as nonconformity and independence. In particular, nonconsensus majority states are possible, as well as mixed phases. Continuous and discontinuous phase transitions can occur, but also transitions from fluctuating phases into absorbing states

    Age differences in children's referential communication performance : an investigation of task effects

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    Exploring accumulative query expansion for relevance feedback

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    For the participation of Dublin City University (DCU) in the Relevance Feedback (RF) track of INEX 2010, we investigated the relation between the length of relevant text passages and the number of RF terms. In our experiments, relevant passages are segmented into non-overlapping windows of xed length which are sorted by similarity with the query. In each retrieval iteration, we extend the current query with the most frequent terms extracted from these word windows. The number of feedback terms corresponds to a constant number, a number proportional to the length of relevant passages, and a number inversely proportional to the length of relevant passages, respectively. Retrieval experiments show a signicant increase in MAP for INEX 2008 training data and improved precisions at early recall levels for the 2010 topics as compared to the baseline Rocchio feedback

    Prison Anger Reduction Programs Evaluation Development Project

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    This report describes efforts to develop Alaska-specific norms for the Minnesota Multiphasic Personality Inventory (MMPI), using the Megargee offender classification system, for use in program evaluations in Alaska correctional facilities, specifically for evaluation of three pilot anger reduction programs initiated at Alaska Department of Corrections institutions in late 1984/early 1985: (1) Women in Crisis (at Fairbanks Correctional Center); (2) M. E. N., Inc. (at Lemon Creek Correctional Center, Juneau); (3) Bering Sea Women's Group (at Nome Correctional Center). The report provides assessments of the three programs and the correctional centers where they were held and makes recommendations for completing the development of Alaska-specific MMPI-based norms and for the administration of the MMPI as pre- and post-test for measuring psychological changes — particularly in hostility/frustration levels — in participants in anger reduction programs.Alaska Council on Domestic Violence and Sexual AssaultIntroduction / Section I. History of the Project / Section II. Psychological Testing / Section III. Site Assessment — Facilities / Section IV. Site Assessment — Programs / Section V. Recommendations / APPENDICES / A. Domestic Violence Evaluation Project: Assessment of Programs for Anger Reduction in Incarcerated Alaskan Prisoners [Project proposal] / B. Letter from Nancy E. Schafer to Barbara Miklos, June 7, 1985 / C. Site Visits / D. Criminal Justice Assessment Cervices, Inc.: Experimental MMPI Scales Availabl

    Sound transmission testing of polymer compounds

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    This is the post-print version of the final paper published in Polymer Testing. The published article is available from the link below. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. Copyright @ 2012 Elsevier Ltd.Acoustic properties of polymer compounds are an important consideration for many applications. Currently, there are standard test methods for the determination of these properties. There is, however, no standard for the equipment used in these tests, only a specification for the test conditions. The objective of this work was to evaluate the operation and performance of a bench top laboratory sound testing system for its potential as a simple cost effective method for the initial evaluation of materials that require specific acoustic properties. The work was limited to an investigation of the property of sound transmission loss (STL). A study of the effect of the mounting conditions for the samples on the STL was carried out. Following this, a series of polymer and polymer composite samples was tested. The results presented demonstrate the potential for the testing system as an effective standard test method for the acoustic properties of polymer composites and other materials.Technology Strategy Board, U
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