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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Death Certification of ‘‘Suicide by Cop’’

Neitzel, Amber Rae 03 1900 (has links)
A Thesis submitted to The University of Arizona College of Medicine - Phoenix in partial fulfillment of the requirements for the Degree of Doctor of Medicine. / Death certification of ‘‘suicide by cop’’ is controversial among some medical examiners and coroners. We present five such deaths that were certified as suicides and discuss the medico-legal issues involved with these certifications. To certify such a death as a suicide, certain criteria should be met. Suicide by cop is a circumstance that involves competing intentional acts that may result in dichotomous determinations of the manner of death. Despite the absence of direct self-infliction, there is overwhelming evidence that these five individuals intended to end their own lives. Their use of an unusual method to accomplish this goal may inappropriately result in a reflexive certification of homicide. All of the decedents possessed weapons or a facsimile of a weapon. We present five instances of suicide by cop and contend that these types of deaths are best certified as suicides. KEYWORDS: forensic science, forensic pathology, suicide, police, gunshot wounds, manner of death
2

Automação e analise do consumo de energia de um sistema de refrigeração para resfriamento de liquido / Automation, analysis and energy consuption monitoring of a chiller plant

Pinelli, Thiago Gomes 31 July 2008 (has links)
Orientador: Flavio Vasconcelos da Silva / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-11T18:18:51Z (GMT). No. of bitstreams: 1 Pinelli_ThiagoGomes_M.pdf: 3499061 bytes, checksum: 0b7fc1ffa57b990b43362b82cb12bb54 (MD5) Previous issue date: 2008 / Resumo: Nos últimos anos ocorreu um excessivo aumento da demanda elétrica no Brasil devido principalmente a um aumento significativo do consumo industrial e comercial. Sabe-se que os sistemas de refrigeração são grandes consumidores de energia elétrica e este setor sofreu um grande impacto com o racionamento de energia. Além disso, o problema da destruição da camada de ozônio pelos refrigerantes CFC's utilizados nos ciclos frigoríficos proporcionaram uma preocupação adicional quanto os seus efeitos sobre o meio ambiente. Estes dois fatores têm motivado não só o setor produtivo como a comunidade científica a estudar formas de melhorar o desempenho energético dos sistemas de refrigeração. A eficiência energética em equipamentos de refrigeração é cada vez mais importante para indústrias, comércio e residências, devido à magnitude que tais equipamentos representam no consumo de energia elétrica. O processo de melhoria energética em um sistema de refrigeração, inicia-se na fase de projeto, com análise de eficiência exergética de seus componentes e a implementação de controladores nas variáveis do processo. Neste contexto propôs-se, a montagem de um protótipo de resfriamento de líquido completamente automatizado que possibilite a monitoração das variáveis do processo e a análise do consumo de energia elétrica. Os ensaios foram realizados com variações de carga térmica e freqüência do motor em 1800, 1500, 1200 e 900 W e 40, 50, 60 e 70 Hz utilizando condensação à água e condensação a ar. Foram feitas análises dos comportamentos da temperatura de descarga, COP Total, COP Útil e potência consumida. Foram observados, melhores resultados para o sistema com condensação a ar. Observou-se também que para temperaturas de condensação menores, e temperaturas de evaporação maiores, tem-se um aumento no COP total, COP útil e uma redução na temperatura de descarga e no consumo de energia. / Abstract: In the latest years occurred an excessive rise in the electric demand in Brazil due mainly to a significant growth in the commercial and industrial consumption. It is known that cooling systems are big electric energy consumers and that this sector suffered a big impact because of the energy rationing. Besides that the destruction of the ozone layer problems caused by refrigerant fluids (CFC's) created an additional concern ragarding its efects over the environment. Both of these factors have motivated not only the productive sector but also the scientific community to try to develop ways of improving the cooling systems energetic performance. The concern with the energy efficiency in cooling equipments is growing in the industry, commerce and private residence due to the magnitude that these equipments represent in the electric consumption. The procedures to improve the cooling systems in energetic matters are started during the project development, through its components energy efficiency analysis and through the implementation of controllers in the process variables. Within this context it was suggested the assembly of a fully automatic liquid cooling prototype that permit the process variables to be monitored and the electric energy to be analyzed. The condensing temperature, evaporating temperature, discharge temperature, coefficient of performance, (COP), useful coefficient of performance, (useful COP), and power consumption were analyzed. The tests were made using water condenser and air condenser. The compressor frequency was varied from 40 to 70 Hz and the cooling capacity in 1800, 1500, 1200, and 900 W. The best observed results were the ones that used air condensation. It was also noticed that for lower condensing temperatures and higher evaporating temperatures there was a rise in the total COP, useful COP and a reduction in the discharge temperature and in the electrical energy consumption. / Mestrado / Sistemas de Processos Quimicos e Informatica / Mestre em Engenharia Química
3

The Agolmirth Conspiracy

Elston, James C. (James Cary) 12 1900 (has links)
Written in the tradition of the classic spy novels of Ian Fleming and the detective novels of Raymond Chandler, The Agolmirth Conspiracy represents the return to the thriller of its traditional elements of romanticism, humanism, fast-moving action, and taut suspense, and a move away from its cynicism and dehumanization as currently practiced by authors such as John Le Carre' and Tom Clancy. Stanford Torrance, an ex-cop raised on "old-fashioned" notions of uncompromising good and naked evil and largely ignorant of computer systems and high-tech ordinance, finds himself lost in a "modern" world of shadowy operatives, hidden agendas, and numerous double-crosses. He is nevertheless able to triumph over that world when he puts his own honor, his own dignity, and his very life on the line, proving to himself and to his adversaries that such things can still make things easier to see amid today's swirling moral fog.
4

Análise exergoeconômica de um chiller de absorção de 10tr integrado a um sistema de microgeração com microturbinaa gás de 30kw

VILLA, Alvaro Antonio Ochoa 31 January 2010 (has links)
Made available in DSpace on 2014-06-12T17:34:40Z (GMT). No. of bitstreams: 2 arquivo1979_1.pdf: 4262749 bytes, checksum: 6592fa1ffeccb983a84926eb95aa4c5e (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2010 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Este trabalho tem como finalidade o estudo numérico do funcionamento de um chiller de absorção (LiBr-água) de simples efeito em regime permanente, com capacidade de 10TR, acionado por água quente e tendo como fonte de calor os gases de exaustão de uma micro-turbina a gás natural de 30kW de potência, localizado no laboratório Cogencasa da Universidade Federal de Pernambuco. Foi desenvolvida uma metodologia computacional na plataforma EES-32 (Engineering Equation Solver), para avaliar a influência dos principais parâmetros de operação do sistema sobre a capacidade de resfriamento e o COP. A modelagem termodinâmica baseia-se nos princípios de conservação de energia, massa e das espécies, além das correlações de transmissão de calor, sendo conformado por uma serie de funções para a determinação das propriedades termodinâmicas (entalpia e entropia da mistura H2O-BrLi) e coeficientes dos trocadores de calor. A análise exergoeconômica é baseada nos sistemas de unidades produtivas, para avaliar a viabilidade técnica do sistema de cogeração. Para a análise exergética foi calculada a Exergia total dos fluidos de trabalho levando em consideração as parcelas físicas e químicas. O sistema de cogeração foi integrado ao modelo computacional com o propósito de estudar os custos exergéticos e monetários do sistema, verificando o balanço monetário da geração de energia elétrica pela microturbina e a produção de água gelada, mediante a recuperação dos gases da combustão para o acionamento do chiller de absorção. Analisam-se as irreversibilidades para a identificação dos pontos críticos nos componentes do sistema de cogeração. Da análise exergoeconomica, foram analisados os custos mínimos de produção de energia elétrica para produzir lucros para o empreendimento, além da determinação dos custos gerais monetários da produção de água gelada, fria e quente do chiller. Finalmente foram determinados os valores da eficiência energética e exergética global do sistema de cogeração
5

Using a community of practice via a new technology (Moodle) for continuing professional development in Saudi Arabia

Alrubian, Ali Mohammed S. January 2014 (has links)
Given the spread of the implementation of Online Communities of Practice (OCoP) as a new approach to organisational learning in the context of continuing professional development (CPD) programmes in some countries such as the UK, USA and Australia, this study conducts a trial in which the OCoP is introduced for this purpose in Saudi Arabia. The aim of the study is to establish the potential of the OCoP to function as an approach to CPD, and how such a mechanism can be adopted in the Saudi context to have an impact upon teachers’ professional performance and development. I designed the OCoP and the sample was composed of 14 male teachers of ICT in secondary schools located in five different cities in Saudi Arabia. The teachers interacted with each other in the OCoP, discussing eight subjects that they chose for themselves. In order to explore the operation and outcomes of the OCoP, I used qualitative methods, in particular semi-structured interviews, classroom observation of a sample of teachers, and observation and monitoring of teachers’ interaction within the OCoP over a three-month period. The overall findings show the positive impact of adopting an OCoP in CPD programmes. They reveal that some teachers change their practice and improve their levels of reflection. Additionally, the findings show significant differences between the levels of contribution made by teachers in the OCoP compared with their participation and engagement in other general online communities and in training courses attended in the country’s Training Centres. Furthermore, the study points to the importance of commitment and internal motivation among teachers in the context of the OCoP since without this, the overall aims of the Community cannot be achieved. The study also raises critical issues concerning the psychological aspects of teachers’ professional development, specifically the need to allow teachers more autonomy in determining their professional needs, and the requirement for trust to be built among teachers since the presence of such autonomy and trust promotes greater engagement in the CPD process. As a result of the trial OCoP, several avenues for further research are suggested in order to gain a deeper understanding of the potential of OCoPs in the educational field.
6

Système électrodynamique à coefficient de performance supérieur à 1, l'échec de la tentative de reproduction

Nadeau, Raphaël January 2009 (has links)
Ce projet consiste en la compréhension et la reproduction de systèmes électrodynamiques, ou plus spécifiquement électromagnétiques, pouvant potentiellement offrir un coefficient de performance supérieur à 1. Le système plus spécifiquement étudié ici est le MEG (Motionless Electromagnetic Generator).Ce dernier est étudié et analysé en détail dans le but de comprendre et d'expliquer son fonctionnement. Cette analyse consiste principalement en l'identification et l'explication des principaux phénomènes, théories et effets impliqués dans le fonctionnement du MEG. Celle-ci comprend également une analyse d'un prototype construit selon les spécifications de l'inventeur original. Une caractérisation des modèles théoriques et d'un modèle physique ont été faite afin de pousser l'analyse et de pouvoir comparer les résultats attendus, basé sur les théories électrodynamiques traditionnelles, et les résultats réels. Tel que présenté dans le titre, la reproduction du MEG n'a pas donnée les résultats prévus par les concepteurs. Plusieurs explications sont proposées afin d'expliquer pourquoi il en est ainsi.
7

Conception, construction et analyse d'un système de réfrigération à éjecteur

Reddick, J. Christopher January 2012 (has links)
Dans le contexte d'un intérêt grandissant pour le domaine d'efficacité énergétique, les systèmes de réfrigération à compression très répandus offrent des bonnes possibilités d'améliorations. Le présent travail porte sur une étude expérimentale de la possibilité d'augmenter l'efficacité énergétique dans un système de réfrigération où un électeur sert de valve de détente. Un banc d'essai a été conçu et fabriqué qui permet le fonctionnement soit en mode conventionnel soit en mode avec électeur. Le réfrigérant utilisé est le R134a, avec une puissance frigorifique nominale de 5 kW et une consigne de 5ÀC à l'évaporateur et de 40ÀC au condenseur. L'électeur diphasique est muni d'un double col dans la tuyère, dont le premier col est à section variable selon la position d'un pointeau. Les mesures prises ont montré une amélioration de jusqu'à 11 % dans le coefficient de performance, ou COP, en mode électeur par rapport à celui en mode conventionnel. En mode électeur, le rapport de pression fourni par l'électeur était de 1.070 pour un ensemble d'essais complété. En mode électeur, la puissance frigorifique totale était la somme de la puissance thermique de l'évaporateur, dont le titre à l'entrée était très faible, et de la puissance thermique des éléments électriques, qui servaient de surchauffeur. Il a été constaté que la puissance frigorifique à l'évaporateur était au maximum lorsque les deux cols de la tuyère étaient d'aire égale. Un bilan d'énergie et une analyse d'erreur ont confirmé la validité des résultats. Finalement, des suggestions ont été apportées afin de palier aux difficultés vécues avec l'efficacité du séparateur dans le montage. Le besoin important de contrôler le niveau de surchauffe du réfrigérant retournant au compresseur doit faire partie du travail futur. Une avenue prometteuse serait de rajouter un deuxième évaporateur après le séparateur, ou de combiner la fonctionnalité d'un séparateur avec le deuxième évaporateur dans une seule unité. Cette voie fournirait une solution au problème du manque de surchauffe à la sortie du séparateur et laissera plus de marge de manceuvre dans le système de contrôle.
8

Utilisation des éjecteurs pour améliorer les performances des systèmes de réfrigération

Dahmani, Abdelouahid January 2011 (has links)
La présente étude des cycles de réfrigération électeur, i.e. [éjecteur] se fonde sur les principes de la thertnodynamique, i.e. [thermodynamique] classique, de la thermodynamique en dimensions fmies, i.e. [finies] et des transferts de chaleur. Pour étudier l'influence de la pression sur les performances de ces cycles, nous avons fixé la puissance de réfrigération ainsi que les températures des fluides externes à l'entrée des trois échangeurs (générateur de vapeur, condenseur et évaporateur).La performance d'un système de réfrigération varie d'un fluide frigorigène à l'autre; pour le démontrer, une étude comparative entre quatre réfrigérants (R134a, R152a, R290 et R600a) est présentée. Les résultats obtenus montrent que, pour une différence de température donnée entre le réfrigérant et les fluides externes, la quantité de chaleur fournie au générateur de vapeur et la conductance thermique totale des échangeurs diminuent quand la pression du réfrigérant au générateur de vapeur augmente. D'autre part, une différence de température de 3 ÀC est la valeur qui optimise les performances du système à éjecteur pour les quatre fluides. Une analyse des flux exergétiques dans chaque composante du système identifie l'exergie détruite qui doit être prioritairement améliorée pour minimiser les pertes exergétiques du système. Afin de compléter l'étude, une analyse paramétrique du système conventionnel à un seul et à deux compresseurs est représentée avant celle du système qui combine l'électeur, i.e. [l'éjecteur] et le compresseur. Pour finir, nous effectuons une comparaison entre les quatre réfrigérants et les trois systèmes.
9

A COMMERCIAL CCSDS TELECOMMAND PROCESSOR

Shi, Jeff, Flanagan, Barbara, Mao, Tony, Sanford, Terry 10 1900 (has links)
International Telemetering Conference Proceedings / October 23-26, 2000 / Town & Country Hotel and Conference Center, San Diego, California / After a slow start, the CCSDS Telecommand Recommendation is finally being embraced by a large number of NASA, ESA and NASDA space missions. Even some commercial satellites are exploring the possibility of using this advanced protocol. The CCSDS Telecommand is a closed-loop space communication protocol that offers its users a guaranteed data delivery service, which is essential for the satellite control operations. This paper describes a commercial product that supports the CCSDS Telecommand protocol. This product provides Telecommand uplink segmentation, transfer, coding and physical layer services and Command Operations Procedures (COP). Optionally, it provides corresponding functions at the receiving end for command link verification.
10

Thermal Performance Analysis of Cooling Water Loop in HVAC Systems

Wu, Jhih-rong 12 September 2006 (has links)
It is a common problem that the cooling water loop in an HVAC or refrigeration plant is suffering from scaling, corrosion, and bacteria attacks, especially in an open-loop designs. The reason is that, through the open water loop, various kinds of contaminants were trapped and migrated along the water flow, causing condenser scaling, which in turn, leading to its poor thermal performances. The experiment conducted in this study revealed that each condenser temperature increase of 1 ¢J, accounts for a COP decrease of 2.4% to 2.8%.Serious scaling problem might even lead to system malfunction, and hazardous environmental problems. Conventionally, water-treatment in the condenser cooling water loop can be categorized into two parts, namely, the chemical and the physical methods. The chemical treatment is mainly performed by injecting chemicals, mostly acids, into the water loop so that it can circulate through the system and causing scales to peer off from the condenser tubes. In response to the cry of environmental protection, physical treatment has become increasingly important, which utilizes magnetic forces as the primary working principle. The main theme of this study is to validate this principle by full-scale experiments. The Zeta Rod system has been developed under the DLVO theory, with significant performance and is environmentally friendly. Experimental investigation has been performed in comparing the temperature differentials across a condenser, before and after the treatment. The result validated that it has increased from 3.9¢J to 4.2¢J and enhanced the thermal performances of the condenser accordingly.

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