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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

Simulação e análise do efeito da variação de parâmetros sobre a perda de carga e transferência de calor em trocadores de calor casco e tubo

COSTA, Mayse Cíntia Vieira da 29 February 2016 (has links)
Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2016-12-01T14:23:12Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Entrega FINAL - DIssertação Mayse.pdf: 3538021 bytes, checksum: 463b084f4add53d190c15e4ff4ad03be (MD5) / Made available in DSpace on 2016-12-01T14:23:12Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Entrega FINAL - DIssertação Mayse.pdf: 3538021 bytes, checksum: 463b084f4add53d190c15e4ff4ad03be (MD5) Previous issue date: 2016-02-29 / Trocadores de calor são dispositivos que tem como principal objetivo proporcionar a transferência de calor entre dois ou mais fluidos a temperaturas diferentes. Do ponto de vista tecnológico existem vários tipos de configurações para estes equipamentos que depende das características e das demandas de troca térmica, da característica dos escoamentos dos fluídos e das formas construtivas, resultando em dispositivos com variados níveis de sofisticação tecnológica e tamanhos. Do ponto de vista das aplicações industriais, o trocador de calor casco tubo é a configuração mais utilizada em indústrias de processo e normalmente tem uma estrutura de grandes proporções quanto a suas dimensões, apesar de ser de montagem relativamente fácil. Pode ser aplicado para diversas condições de serviços, incluindo pressões extremamente baixas e altas temperaturas. O principal objetivo do presente trabalho é realizar um estudo paramétrico do comportamento termo hidráulico de um trocador de calor casco tubo utilizando simulação numérica por CFD. As características geométricas e operacionais básicas do dispositivo simulado foram definidas previamente e as condições de projeto serviram como sistema base para validação do modelo numérico, juntamente com as técnicas convencionais de dimensionamento para este tipo de equipamento (método de Tinker e método de Kern). A simulação numérica foi desenvolvida na plataforma ANSYS-CFX e após validação o modelo foi utilizado para estudos como variação de vazão, espaçamento e corte de chicanas, tendo como base de comparação o efeito desses parâmetros sobre a perda de carga e transferência de calor. / Heat exchangers are devices that aims to provide heat transfer between two or more fluids at different temperatures. From a technological point of view there are several types of settings for these devices depends on the characteristics and demands of thermal exchange, the characteristic of the flow of fluids and constructive ways, resulting in devices with varying levels of technological sophistication and sizes. From the point of view of industrial application, the shell-tube heat exchanger is the configuration most used in process industries and usually has a structure as their major dimensions, despite being relatively easy assembly. Can be applied to various service conditions, including extremely low and high temperatures pressures. The main objective of this study is to conduct a parametric study of the hydraulic behavior of a term Casco tube heat exchanger using numerical simulation by CFD. The basic geometric and operational characteristics of the simulated device are predefined and the design conditions served as a base system for validation of the numerical model, along with the conventional design techniques for this type of equipment (Tinker method and Kern method). The numerical simulation was developed in ANSYS CFX-platform and after validating the model was used for parametric studies taking as a basis for comparison the effect of these parameters on the pressure drop and heat transfer.
2

"Trained to Empire, trained to rule the waves" : En jämförande analys mellan John le Carrés Tinker Tailor Soldier Spy och Tomas Alfredsons filmadaption

Andersson, Axel January 2015 (has links)
No description available.
3

Tinkering with Student Speech in the Age of Social Media

Burnham, Lola A 01 May 2018 (has links)
This dissertation investigates the issue of public junior high and high school students who are punished at school for their online speech that they created when they were off-campus. Specifically, it examines the issue of when students are punished at school for online speech that criticizes teachers and administrators, rather than the issue of student-on-student cyberbullying. Because the United States Supreme Court has not yet accepted any case that involves off-campus online student speech, this dissertation summarizes and analyzes federal appellate court decisions in such cases. Appellate courts in six federal circuits have heard and ruled in cases involving students’ off-campus online speech. This dissertation examines the precedent those courts have applied to outline the circumstances under which the courts find for the student or school officials. Because court decisions depend on the application of precedential case law, this dissertation includes a thorough examination of those major Supreme Court student speech precedents: West Virginia State Board of Education v. Barnette, Tinker v. Des Moines Independent Community School District, Bethel School District No. 403 v. Fraser, Hazelwood School District v. Kuhlmeier, and Morse v. Frederick. This research project also examines how legal analysts are currently interpreting the issue of school punishment of off-campus online speech to determine how they recommend courts proceed in such cases. Through review of both precedent and law review articles, it examines two branches of legal thought that underlie the issue: what role courts see schools playing in the education of students as citizens and how far courts are willing to go in extending schools’ “in loco parentis” role to off-campus speech. It also reports on societal issues underlying student speech on social media: how social media users can create “community” online and how teens spend their time online. Because legal research carries with it the tradition of offering guidance to judges on how to rule in a particular area, this dissertation concludes with a proposal for how courts, including the U.S. Supreme Court, should rule in cases involving student speech that is critical of school officials or school policy to grant students complete First Amendment protection for all off-campus online speech that does not threaten the school community with violence or libel anyone, whether school official or student.
4

Psychometric Issues Related to the Tinker Toy Test

Guzman, Daniel 01 January 2015 (has links)
An evaluation of executive functioning is a critical component of a comprehensive assessment of higher cerebral functioning. The Tinker Toy Test (TTT) was introduced in 1982. This test allows an individual to demonstrate the extent of their executive capacities by permitting them to initiate, plan, and structure a potentially complex activity and carry it out independently in an unstructured fashion and administration is simple. This is a departure from more complex and structured tests of executive function. There is a dearth of research on the TTT and this study seeks to examine some of the psychometric properties of this instrument; i.e., working time minimum, gender effects, convergent and divergent validity, and potential intellectual correlates. Participants included 10 male and 30 female student volunteers from a large university in Central Florida. Participants had no history of neurologic disease/trauma or conditions that would affect motor functioning of the upper extremities. Participants completed a demographic questionnaire, the WASI-II, and the TTT. A two-way mixed-design ANOVA examining TTT scores as a function of work time and gender revealed a non-significant gender main effect, F(1, 21) = .09, p = .767. The work time main effect was not significant, , F(1, 21) = .324, p = .575. A significant work time x gender interaction was observed, F(1, 21) = 4.983, p = .037. Convergent validity was assessed by comparing the TTT scores with the Matrix Reasoning subtest, r(38) = .32, p = .044, and the Similarities, r(38) = .34, p = .03, subtest on the WASI-II. Divergent validity was assessed by comparing TTT scores to the Block Design subtest of the WASI-II, r(38) = .245, p = .127. No significant correlation was found between intelligence and TTT (VCI, r(38) = -.16, p = .335; PRI, r(38) = .15, p = .344; and FSIQ, r(38) = -.02, p = .928). The data supports the continued use of the 5-minute working time minimum presented by Lezak, as this temporal index was a more accurate representation of executive functioning. This study demonstrated no association between TTT scores and intellectual functioning. The findings of this study support the validity of this underutilized test of executive functioning and its inclusion in neuropsychological test batteries.
5

Tinkering with Taste: NBC's Prime Time Television Programming 1978-1986

Hunt, Randall M. 12 1900 (has links)
The thesis explores how Grant Tinker's philosophy of quality programming grew into a working ideology which would serve as the basis for its rise from last place to first place in ratings and profits from 1978 to 1986. This thesis paper explores the prime time history of NBC from 1978 to 1986. The network is examined in terms of its programming history, its economic situation, and the men who presided over the entity, all within the time frame listed above. The thesis focuses on the strategies and philosophies of the three men crucial to the direction the network took during the above time frame: Fred Silverman, President of the network from 1978 to 1981, Grant Tinker, Chairman from 1981 to 1986, and Brandon Tartikoff, Programming Chief from 1980 to 1991.
6

Vers une dramaturgie de l’errance : Les scènes anglaises et irlandaises du début du XXe siècle à nos jours / Erring and Wandering on XXth-Century Irish and British Stages : Towards a New Dramaturgy?

Guedj, Emmanuelle 01 October 2010 (has links)
L’errance est thématiquement présente dans le théâtre irlandais du début du XXe siècle. Le personnage errant est tout d’abord un moyen pour le dramaturge d’explorer et de dénoncer la perte ressentie par le peuple irlandais. Les vagabonds mis en scène expriment également le questionnement métaphysique de l’homme sur terre. Dans la Seconde moitié du siècle, l’errance infiltre la structure de la pièce, qu’il s’agisse de pièces irlandaises ou anglaises. Elle demeure, à travers le siècle, un thème de prédilection pour explorer les traumatismes, qu’ils soient économiques, politiques ou éthiques. La crise de valeurs du XXe siècle trouve écho sur des scènes théâtrales qui n’ont de cesse de questionner les certitudes, et qui mettent au jour la « déroute » du sens. L’ampleur et l’évolution de l’errance, à la fois thématique et structurelle, à travers des œuvres dramatiques étalées sur tout le XXe siècle, permettent de confirmer l’existence d’une dramaturgie de l’errance. Forte d’un siècle de remise en cause des certitudes, celle-ci se dessine à travers de nombreux exemples tirés des scènes anglaises et irlandaises du XXe siècle. / Thematically speaking, wandering and erring are particularly noticeable in early XXth century Irish drama. Playwrights stage vagrants, tramps, and Tinkers as a means to explore the loss felt by a large part of the Irish population throughout history. These characters also express metaphysical questions which will be echoed in the second half of the century. From being rather important themes, wandering and errancy gradually invade the very structure of the plays, be they Irish or British. Wandering has remained a major way of exploring trauma-related situations, be they economical, political or ethical. As the stage keeps questioning certainties, directions and sense are played with. The thematical and structural roles of wandering onstage highlight the widespread existence of a skeptical dramaturgy debunking trust and conviction.
7

"Tinkering" with Student Rights: School Walkouts and the Implications of Discipline Practice and Policy on Students' Right to Protest

Weissler, Hannah 01 January 2019 (has links)
In this study, I examine the extent to which students’ rights to free speech and expression were violated in response to the nationwide school walkouts that took place during the spring of 2018. Students hold the right to political speech and expression under the landmark Supreme Court Case, Tinker v. Des Moines (1969). However, the rights students maintain to participate in protest during school hours is somewhat unclear. Using a two-pronged case study analysis, I explore the question of student rights and potential violations in the face of protest through examining school disciplinary responses alongside disciplinary policy and disciplinary policy in the context of Tinker. Findings highlight a widespread gap in school and district-level policy specific to protest or other types of political expression and the need for such policy when protecting the rights students hold under Tinker.
8

Analyse mathématique et contrôle optimal pour les équations d’advection-diffusion : Application au problème de transfert de nutriments pour les plantes en agroécologie / Mathematical analysis and optimal control of advection-diffusion equations : Application to nutrient transfer for plant in agroecology

Louison, Loïc 02 October 2015 (has links)
Les terres agricoles ont été durablement contaminées à la fois par les pesticides mis à la disposition des agriculteurs pour lutter contre les charançons et autres insectes nuisibles, et par les engrais azotées pour augmenter la productivité chez les plantes.Des recherches récentes concernent des cultures alternatives écologiques utilisant les plantes de service qui fournissent les nutriments aux plantes principales. Ce travail de thèse s'inscrit dans cette perspective, d'un point de vue modélisation.L'accent est mis sur la résolution de problèmes de contrôle du phénomène d'absorption de nutriments, par les racines dans la rhizosphère (partie proche des racines), en considérant les deux cas de sols : sol sain et sol pollué.Ces phénomènes d'absorption sont modélisés par des systèmes d'advection-diffusion de type Nye-Tinker-Barber (NTB). La concentration de nutriments absorbée, solution du problème, est une fonction du temps et de l'espace.On étudie l'existence de solution du système NTB dans les deux cas où la fonction d'absorption de nutriments à la frontière (surface de la racine) appelée fonction de Michealis-Menten, est linéaire et/ou non linéaire, à l’aide des outils d’analyse fonctionnelle. On étudie ensuite les problèmes de contrôle optimal associés au système NTB, en considérant les deux cas linéaire et non linéaire, en application pour les deux cas d’absorption de nutriments en sol non pollué puis en sol pollué. Pour le premier cas, on utilise les techniques classiques de recherche d'un contrôle pour les systèmes distribués, tandis que, pour le second cas, on fait appel aux notions de contrôle sans regret et contrôle à moindres regrets de J.-L. Lions. Les contrôles obtenus pour les différents problèmes sont caractérisés chacun par un système d'optimalité (SO) cas sans pollution, et système d’optimalité singulier (SOS) dans le cas avec pollution.= / Agriculture soils were highly contaminated for a long time by pesticides which were widely used by producers to fight against weevils. Soils where also contaminated by the use of fertilizers to increase the plant development. An ecological alternative using service plants is encouraged following recent research. The aim of this work is to give a mathematical and a modelling point of view as we study the mecha- nisms of nutrient transfer to plants using the mathematical analysis and optimal control theories. The two cases of polluted and non-polluted soils are considered. The nutrient transfer and uptake processes are modeled by an advection-diffusion system derived from the Nye-Tinker-Barber (NTB) model. The absorbed nutrient concentration represented by the Michaelis-Mention function at the root surface of the principal plant, depends on time and space. We study the existence of a solution for the linear and nonlinear NTB systems, then we characterize the opti- mal control which corresponds to the added nutrients from the service plant. For the pollution case, we use the concept of low-regret and no-regret control of J.-L. Lions.

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