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Performance Criteria for Knee-Brace Timber Frames with Mortise and Tenon JointsHalisky, Zachary J. 09 December 2022 (has links)
Traditional mortise and tenon timber frames have been used in modern construction for a substantial period of time with acceptable performance against weather phenomena and other hazards. However, performance criteria for this style of timber framing are not well defined in current codes and standards. To determine performance criteria for free-standing timber frames with knee-braces, three tasks were undertaken: (1) Two timber frame specimens were tested under cyclic loads to determine hysteretic behavior, damage states, and to explore rehabilitation of a damaged member using self-tapping screws. Three damage states for were identified: peg shear, tenon tearout, and post or beam splitting. Self-tapping screws were able to restore the strength of the 2-peg timber frame with the damaged beam, but not the stiffness of the frame. (2) Four timber frame mortise and tenon connection specimens were subjected to damp conditions for six months and then tested under monotonic tensile load to determine the effect of joint details. The results indicated that connection types tested had similar strength and stiffness. (3) Twelve free-standing timber frames with knee braces located at various sites across the United States were tested in the field under impulse loading to determine the fundamental period of vibration and to estimate damping. A relationship between the fundamental period and the mean roof height was fit to the test data using a power-law equation, and three sets of parameters were determined: a lower-bound equation for seismic loads, an upper-bound equation for wind loads, and mean equation for human-induced vibration performance criteria.
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Performance Criteria Recommendations for Mortars Used in Full-Depth Precast Concrete Bridge Deck Panel SystemsScholz, Donald P. 20 December 2004 (has links)
The use of full-depth precast concrete bridge deck panels is becoming more and more attractive to transportation authorities throughout the country. In comparison to conventional cast-in-place decks, precast decks are of higher quality, allow for the bridge to be opened to traffic in less time and are easier to maintain, rehabilitate, and replace. This ultimately results in lower costs for transportation authorities and less disruption for the motoring public. Unfortunately, the use of precast deck panel systems is hindered by the lack of design standardization and information regarding the performance of such systems. This research focuses on a key element of the system, the mortar or grout, which is used to connect the precast panels to the bridge girders by filling the space in the horizontal shear pockets and the haunches. Several essential mortar characteristics were identified and investigated in order to create a specification that indicates required performance criteria for mortars. This specification can be used to determine whether particular mortars or grouts are suitable for use in a full-depth precast concrete bridge deck panel system. / Master of Science
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Contribuição para o programa de necessidades de laboratórios didáticos de química do ensino superior / Contribution to the program requirement for chemistry teaching laboratories of higher educationCivile, Natalia Raiunec 25 October 2010 (has links)
Esta dissertação de mestrado insere-se no contexto da análise de desempenho técnico construtivo de edifícios. O objetivo é sistematizar informações qualitativas e quantitativas para subsidiar o programa de necessidades de projetos de laboratórios de química do ensino superior, para atendimento das demandas correntes de segurança e habitabilidade desses ambientes. A pesquisa parte de uma revisão bibliográfica em bases nacionais e internacionais sobre análise de desempenho de edifícios habitacionais (ABNT NBR 15575/2008) e particularmente, do programa de necessidades das instalações laboratoriais em edifícios do ensino superior. O trabalho de campo é realizado por meio da metodologia do estudo de caso único nos laboratórios do edifício do Instituto de Química da Universidade de São Paulo, onde foram levantados e analisados os padrões de uso do edifício, os usuários e suas necessidades e expectativas. O produto resultante desta análise e do confronto com as referências de desempenho será a relação de requisitos e critérios que podem ser utilizados na elaboração de programa de necessidades e em soluções de projetos de instalações laboratoriais de maneira responsável e consciente. / This masters degree dissertation is inserted in the context of a technical constructive building development analysis. The objective is to systematize qualitative and quantitative information, in order to subsidize the necessities of higher education chemical laboratories project, to accomplish the current demands for safety and habitability of these environments. The research is based on a bibliographical revision of national and international sources, related to the analyses on the development of habitational buildings (ABNT NBR 15575/2008) and program elements linked especially to the laboratorial installations in buildings of higher education. The field work is done based on the unique case study methodology in the laboratories of the Chemistry Institute of the University of São Paulo (IQUSP), where the usage standards of the building, and users necessities and expectations have been gathered and analyzed. The product resulting from this analysis and from the confrontation with the performance standards will be the requirements inventory and the criteria that should be utilized in the elaboration of the program of needs and as solutions to laboratorial installations projects, in a responsible and conscious approach.
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Contribuição para o programa de necessidades de laboratórios didáticos de química do ensino superior / Contribution to the program requirement for chemistry teaching laboratories of higher educationNatalia Raiunec Civile 25 October 2010 (has links)
Esta dissertação de mestrado insere-se no contexto da análise de desempenho técnico construtivo de edifícios. O objetivo é sistematizar informações qualitativas e quantitativas para subsidiar o programa de necessidades de projetos de laboratórios de química do ensino superior, para atendimento das demandas correntes de segurança e habitabilidade desses ambientes. A pesquisa parte de uma revisão bibliográfica em bases nacionais e internacionais sobre análise de desempenho de edifícios habitacionais (ABNT NBR 15575/2008) e particularmente, do programa de necessidades das instalações laboratoriais em edifícios do ensino superior. O trabalho de campo é realizado por meio da metodologia do estudo de caso único nos laboratórios do edifício do Instituto de Química da Universidade de São Paulo, onde foram levantados e analisados os padrões de uso do edifício, os usuários e suas necessidades e expectativas. O produto resultante desta análise e do confronto com as referências de desempenho será a relação de requisitos e critérios que podem ser utilizados na elaboração de programa de necessidades e em soluções de projetos de instalações laboratoriais de maneira responsável e consciente. / This masters degree dissertation is inserted in the context of a technical constructive building development analysis. The objective is to systematize qualitative and quantitative information, in order to subsidize the necessities of higher education chemical laboratories project, to accomplish the current demands for safety and habitability of these environments. The research is based on a bibliographical revision of national and international sources, related to the analyses on the development of habitational buildings (ABNT NBR 15575/2008) and program elements linked especially to the laboratorial installations in buildings of higher education. The field work is done based on the unique case study methodology in the laboratories of the Chemistry Institute of the University of São Paulo (IQUSP), where the usage standards of the building, and users necessities and expectations have been gathered and analyzed. The product resulting from this analysis and from the confrontation with the performance standards will be the requirements inventory and the criteria that should be utilized in the elaboration of the program of needs and as solutions to laboratorial installations projects, in a responsible and conscious approach.
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Durability and Fatigue Behavior of CIP Concrete Connections for Accelerated Bridge ConstructionZhu, Peng 01 December 2010 (has links)
Continuous longitudinal and transverse U-bar joint connections between flanges of the decked bulb-Ts (DBTs) or between precast panels for accelerated bridge construction are investigated. The procedure for selecting durable closure pour (CP) materials for the connections is discussed firstly. The accelerated construction is quantified as two categories: overnight cure and 7-day cure of CP materials. Candidate materials are selected first based on literature review as well as tests of compressive strength and flow and workability. Then, performance criteria for selecting durable CP materials for both categories are developed based on durability tests of selected candidate materials. These durability tests include freezing-and-thawing durability, shrinkage, bond, and permeability tests. To investigate the longitudinal U-bar joint details, four pairs of full-scale slabs connected by a U-bar detail with one of the selected CP materials, overnight cure and 7-day cure, were tested. The loading demand necessary in the slab testing is determined based on the maximum forces in the longitudinal joint from an analytical parametric study. Static and fatigue tests under four-point flexural loading and three-point flexural-shear loading were conducted. Test results were evaluated based on flexural capacity, curvature behavior, cracking, deflection and steel strain. The transverse U-bar joint details are investigated to provide negative moment continuity in the multi-span bridges. Four full-scale specimens connected by a U-bar detail with one of the selected CP materials, overnight cure and 7-day cure, were tested. Static and fatigue tests under tension loading were conducted. The loading demand necessary in the beam testing is determined based on the maximum forces in the transverse joint from an analytical study. Test results were evaluated based on tension capacity, cracking, displacement and steel strain. Based on the test results, the developed longitudinal and transverse U-bar joint details are viable connection systems.
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Selection And Utilization Of Criteria For Process Development In Green Production Of Organic ChemicalsHaydaroglu, Sencan 01 February 2008 (has links) (PDF)
Sustainability and green engineering are two main concepts considered throughout this study. Sustainability deals with the utilization of renewable and replaceable sugar-based twelve most promising building blocks included in the report prepared by U.S. Department of Energy and green engineering concept is related with the incorporation of environmental performance criteria to chemical process design. Process performance criteria at the conceptual design stage are selected as persistence, bioaccumulation and aquatic toxicity, economical potential of the processes, atom & / mass efficiency of the processes and the relationship between Gibbs free energy of reaction values and economical potential. It is observed that bioaccumulation potentials of both the raw materials and products are low. Petrochemical raw materials are more persistent in air than the bio-based ones. The aquatic toxicity of bio-based raw materials is low / whereas some of the petrochemicals are moderately toxic and allyl alcohol and acrylonitrile among the petrochemicals are classified as highly toxic. Bio -based routes are not economically feasible with 2002 market prices. Atom and mass efficiencies of petrochemical reactions for a group of chemicals are higher than bio-based ones due to mostly addition or substitution reactions. Among high number of products, 1,3 propanediol production from glycerol with two microorganisms is analyzed at preliminary design stage. Process performance criteria are selected as material and energy consumption, cooling water requirement, CO, CO2, SO2 and NOX emissions to the atmosphere per unit of 1,3 propanediol production. Klebsiella pneumoniae process requires less cooling water, but it is less energy efficient and causes higher emissions.
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Risk Analysis Based on Performance Criteria: A Food Safety Control System and Decision-making Tool to Control Salmonella from Whole BroilersAlshuniaber, Mohammad A.f. 21 August 2014 (has links)
Risk analysis is a powerful science-based tool that can be used to control and mitigate microbial food safety hazards. Codex recommends conducting preliminary risk management activities (PRMAs) to initiate risk analysis and to plan the risk assessment process. The information learned from these PRMAs should be utilized to construct a quantitative microbial risk assessment (QMRA) model. Then, risk management activities can utilize the QMRA model to identify and select microbial risk management (MRM) options. In this project, Codex recommendations for conducting risk analysis were followed to analyze the risk of acquiring salmonellosis from whole broiler (meat chickens) consumption within the United States.
At the first stage, the risk of Salmonella on whole broilers was quantitatively estimated by attributing reported annual salmonellosis to whole broilers. A quantitative microbial risk assessment (QMRA) model was constructed to build an informative risk analysis model based on performance criteria, while minimizing associated modeling complications.
The QMRA model was constructed in Excel® (Microsoft Corporation, Redmond, WA, USA) with the @RISK® Add-ins software (Palisade Corp., Ithaca, NY, USA). @RISK® software was used to perform Monte Carlo simulations that account for attendant uncertainties. After the model was tested and calibrated, it estimated the annual salmonellosis cases from whole broilers as 216,408 case/year that corresponds to the number of salmonellosis reported by Center for Disease and Control Prevention (CDC). Furthermore, sensitivity analysis was performed where 16 sensitive inputs (potential places for food safety interventions) and 10 data gaps (inputs that significantly affect the overall uncertainty) were reported.
Some QMRA model results were transformed to MRM metrics. These MRM metrics, including ALOPs (Appropriate Level of Protection), FSOs (Food Safety Objectives), POs (Performance Objectives), and PC (Performance Criteria), were calculated along with a sampling plan for a food safety control system. The MRM metrics were utilized to identify and plan food control interventions such as risk communication, auditing, inspection, and monitoring. Furthermore, the QMRA model was utilized to identify and to quantitatively evaluate food safety interventions that affect Salmonella prevalence and/or concentration. / Ph. D.
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Performance evaluation of bankruptcy prediction models: An orientation-free super-efficiency DEA-based frameworkMousavi, Mohammad M., Quenniche, J., Xu, B. 2015 January 1921 (has links)
Yes / Prediction of corporate failure is one of the major activities in auditing firms risks and uncertainties. The design of reliable models to predict bankruptcy is crucial for many decision making processes. Although a large number of models have been designed to predict bankruptcy, the relative performance evaluation of competing prediction models remains an exercise that is unidimensional in nature, which often leads to reporting conflicting results. In this research, we overcome this methodological issue by proposing an orientation-free super-efficiency data envelopment analysis model as a multi-criteria assessment framework. Furthermore, we perform an exhaustive comparative analysis of the most popular bankruptcy modeling frameworks for UK data including our own models. In addition, we address two important research questions; namely, do some modeling frameworks perform better than others by design? and to what extent the choice and/or the design of explanatory variables and their nature affect the performance of modeling frameworks?, and report on our findings.
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Multi-criteria ranking of corporate distress prediction models: empirical evaluation and methodological contributionsMousavi, Mohammad M., Quenniche, J. 2018 March 1919 (has links)
Yes / Although many modelling and prediction frameworks for corporate bankruptcy
and distress have been proposed, the relative performance evaluation of prediction models
is criticised due to the assessment exercise using a single measure of one criterion at
a time, which leads to reporting conflicting results. Mousavi et al. (Int Rev Financ Anal
42:64–75, 2015) proposed an orientation-free super-efficiency DEA-based framework to
overcome this methodological issue. However, within a super-efficiency DEA framework,
the reference benchmark changes from one prediction model evaluation to another, which
in some contexts might be viewed as “unfair” benchmarking. In this paper, we overcome
this issue by proposing a slacks-based context-dependent DEA (SBM-CDEA) framework
to evaluate competing distress prediction models. In addition, we propose a hybrid crossbenchmarking-
cross-efficiency framework as an alternative methodology for ranking DMUs
that are heterogeneous. Furthermore, using data on UK firms listed on London Stock
Exchange, we perform a comprehensive comparative analysis of the most popular corporate
distress prediction models; namely, statistical models, under both mono criterion and
multiple criteria frameworks considering several performance measures. Also, we propose
new statistical models using macroeconomic indicators as drivers of distress.
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Desenvolvimento de um método de tomada de decisão na escolha de projetos de processos de fabricação utilizando critérios de desempenho sistêmicosAlbino, Rogério Celeghini 19 September 2008 (has links)
Made available in DSpace on 2015-03-05T17:04:33Z (GMT). No. of bitstreams: 0
Previous issue date: 19 / Nenhuma / Em um mercado competitivo e sujeito a mudanças cada vez mais freqüentes, as alternativas para a melhoria dos produtos e processos necessitam ser constantemente avaliadas. Neste aspecto, a tomada de decisão tem grande relevância, principalmente nas decisões estratégicas, pois elas podem determinar o sucesso ou a ruína da empresa, dependendo do grau de risco, incerteza e dos critérios adotados para a tomada de decisão. Freqüentemente decisões são tomadas nas organizações considerando-se experiências em processos similares ou utilizando-se de ferramentas tradicionais. Porém, estas decisões são muitas vezes pontuais, resolvendo um problema específico e esquecendo o restante do sistema. O resultado é a solução de alguns problemas e o agravamento de outros, ou até mesmo o surgimento de problemas inexistentes em tal sistema. Dentro deste contexto, o Pensamento Sistêmico tem grande importância. Nesta pesquisa procurou-se direcionar os critérios para a tomada de decisão dentro do conceito sistêmico, ou seja, visualiza / In a competitive market, subject to frequent changes, the alternatives for improving products and processes need to be constantly evaluated. Here, the decision making has great significance, especially in strategic decisions, as they could determine the success or ruin the company, depending on the degree of risk, uncertainty and the criteria adopted for the decision. Frequently decisions are taken in organizations, considering experiences in similar processes or using traditional tools. However, these decisions are often isolated, by solving a specific problem and ignoring the rest of the system. The result is the solution of some problems and the worsening of others or even the growth of unknown problems in this system. Within this context, the Systems Thinking has great importance. This study sought to address the criteria for decision making within the Systems Thinking concept, by viewing the entire system and sharing this vision for all decision makers. Also within the Systems Thinking, the Scenario Plan
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