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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.
151

Pulsão de morte em ação: a sublimação a partir de The Wire / Death drive in action: sublimation after The Wire

Camila Lousana Pavanelli De Lorenzi 20 May 2016 (has links)
Este trabalho analisa a série televisiva The Wire (EUA, 2002-2008) como forma de investigar os conceitos psicanalíticos de sublimação e realidade. The Wire toma como ponto de partida o tráfico de drogas em Baltimore, nos Estados Unidos, para examinar o funcionamento de diversas instituições da cidade: polícia, sindicato de estivadores, prefeitura, escola e imprensa. Primeiramente, situamos The Wire no contexto das séries televisivas norte-americanas e consideramos sua estrutura formal e aspectos narrativos e visuais. Em seguida, procedemos a uma narrativa comentada das cinco temporadas da série, atentando para os modos de organização do tráfico de drogas em cada uma delas. O capítulo seguinte consiste em uma investigação dos conceitos de sublimação e realidade na obra freudiana, dividida em três seções: a constituição do aparelho psíquico, as pulsões e seus destinos e o mal-estar na cultura. Por fim, relacionamos as duas investigações realizadas anteriormente, chegando à noção de uma sublimação que está a serviço de Tânatos, ou seja, da destruição. O alvo dessa destruição, nas sociedades capitalistas atuais, é o corpo humano e o corpo da Terra a natureza, entendida como recurso infinito a ser explorado. Essa sublimação, em que a pulsão de morte associa-se à de dominação, levou-nos a considerar a realidade a partir de um eixo pulsional: há realidades eróticas e realidades tanáticas / This work looks at television show The Wire (USA, 2002-2008) as a means to investigate the psychoanalytic concepts of sublimation and reality. The Wire takes drug trafficking in Baltimore as a starting point to consider the institutions of the police, the stevedores union, the city government, city schools and the press. This dissertation first situates The Wire within the context of US television and considers its formal structure and visual and narrative aspects. It then proceeds to describe and comment on the five seasons of the show, paying special attention to the modus operandi of drug trafficking in each of them. The following chapter is an investigation of the concepts of sublimation and reality throughout Freuds writings, divided into three sections: the constitution of the psychic apparatus, the drives and their vicissitudes and the civilization and its discontents. Lastly, this work connects the studies of The Wire and Freud conducted in previous chapters and advances the notion of a type of sublimation which is at the service of Thanatos, i.e., destruction. The target of such destruction in current capitalist societies is the body of humans and the body of the Earth namely nature, understood as an array of infinite resources to be exploited. This sublimation, in which the death drive is fused with the domination drive, has prompted the consideration of reality from a drive perspective: there are both erotic and thanatic realities
152

Estudo da viabilidade técnica e econômica da substituição de fios de ouro por fios de cobre em memórias DRAM

Trevizan, João Pedro Gonçalves 15 June 2016 (has links)
Submitted by Silvana Teresinha Dornelles Studzinski (sstudzinski) on 2016-08-04T14:39:04Z No. of bitstreams: 1 João Pedro Gonçalves Trevizan_.pdf: 2398963 bytes, checksum: 7bbf859367acdb155c3b917d8275c41d (MD5) / Made available in DSpace on 2016-08-04T14:39:04Z (GMT). No. of bitstreams: 1 João Pedro Gonçalves Trevizan_.pdf: 2398963 bytes, checksum: 7bbf859367acdb155c3b917d8275c41d (MD5) Previous issue date: 2016-06-15 / itt Chip - Instituto Tecnológico de Semicondutores da Unisinos / PADIS - Programa Federal de Apoio a Indústria de Semicondutores / Este estudo avalia uma proposta de substituição de fio de ouro por fio de cobre no processo de wire bonding em memórias DRAM DDR3 encapsuladas no Brasil. A viabilidade técnica da aplicação desta tecnologia para este componente foi testada na prática em uma empresa coreana, com a produção de amostras e verificação das características de qualidade das mesmas. Após otimização de parametros da primeira solda por DOE, foi possível obter resultados dentro das especificações do processo e semelhantes aos obtidos com o fio de ouro. Após a confirmação da viabilidade técnica, foi verificado a viabilidade econômica deste projeto, calculando o custo de implementação e estimando o tempo para retorno do investimento através dos métodos de payback simples e descontado. Devido à necessidade de aquisição de máquinas soldadoras de custo elevado, o payback descontado resultou em seis anos e onze meses, o que representa um risco alto considerando o dinamismo do mercado de semicondutores e a eminente substituição do encapsulamento BOC pela tecnologia de flip chip / This study evaluates the proposal of gold wire for copper wire replacement in the wire bonding process used in DRAM DDR3 memory packaging in Brazil. The technical feasibility of applying this technology to the component has been verifyed in practice on a Korean company, with the production of samples and the examination of quality characteristics, such as bond pull force and bond shear strenght, intermetallic compound and bonding pad structure. After parameters optimization of the first bond by DOE, it was possible to obtain results within process specifications and similar to those obtained with the gold wire. After confirming the technical feasibility, the economic viability of this project was verified by calculating the cost of implementation and the necessary time to recover the investment, through the simple and discounted payback methods. Because of the need of purchasing costly wire bonding machines, the discounted payback resulted in six years and eleven months, which represents a high risk investment, considering the semiconductor market dynamism and the imminent replacement of BOC package by flip chip technology.
153

Design and construction of a new actuator for the LHC wire scanner / Conception d'un actionneur pour le nouveau Wire Scanner du LHC

Koujili, Mohamed 08 February 2013 (has links)
Le LHC met en collision deux faisceaux de protons avec une énergie de 7 Tevchacun, entrainant ainsi un taux de particules d'environ 109 Hz. Le taux departicules est déterminé la production d'une coupe transversale, une constancenaturelle, la luminosité et un paramétre dépendant de l'accélérateurcapable de décrire les faisceaux de particules. La luminosité dépend dunombre de particules dans chaque faisceau linéairement et des dimensionstransversales du faisceau inversement. Elle augmente avec la densité dufaisceau de particules et en conséquence, la probabilité d'interactions estaccrue. Pour optimiser les tailles des faisceaux transversaux, on utilisedes dispositifs de contrle de pro_le, qui permettent de mesurer les changementsde paramétres dépendants. A l'intérieur du LHC, trois di_érentstypes de dispositifs de contrle des pro_les sont installés, savoir le WireScanner (WS), le Synchroton Light Monitor et le Rest Gas Pro_le Monitor.Le WS est considéré comme étant le plus précis de ces trois dispositifsde contrle et sert d'appareil de calibrage pour les deux autres. Ils'agit d'un appareil électromécanique qui mesure l'état de densité du faisceautransversale de faon intermittente. Lorsque le cble traverse le faisceau,l'interaction particule-matiére génére une cascade de particules secondaires.Ces derniers sont interceptés par un scintillateur, lequel est attaché un photo-multiplieur, et ce a_n de mesurer l'intensité de la lumiéreainsi produite. L'amplitude du signal lumineux est proportionnelle la densité de la portion de faisceau interceptée. L'acquisition de la position du_l et celle de l'intensité du signal sont synchronisées avec la fréquence dela révolution de particules puis sont combinées pour construire le pro_lede densité du faisceau transversal. Le WS est installé et mis en marchedans tous les accélérateurs circulaires du CERN sur une base réguliére / The LHC collides two protons beams with an energy of 7 TeV each resultingin a aimed total particle rate of about 109 Hz. The particle rateis determined by the production cross section, a natural constant and theluminosity accelerator dependent parameter describing the particle beams.The luminosity depends on the number of particles in each beam linearlyand on the transverse dimensions of the particle beam inversely. It increaseswith the particle beam density and therefore the probability of interactions.To optimize the transverse beams sizes, pro_le monitors are used to measureparameter depending changes. Within the LHC, three di_erent typesof pro_le monitors are installed: Wire scanner (WS), Synchrotron lightmonitor and Rest Gas Pro_le Monitor. The WS monitor is considered tobe the most accurate of these monitors and serves as a calibration devicefor the two others. The WS is an electro-mechanical device which measuresthe transverse beam density pro_le in an intermittent way. As the wirepasses through the beam, the particle-matter interaction generates a cascadeof secondary particles. These are intercepted by a scintillator, which isattached to a photomultiplier in order to measure the intensity of the lightthereby produced. The light signal amplitude is proportional to the densityof the intercepted beam portion. The acquisitions of the wire position andthe intensity signal are synchronized with the particle revolution frequencyand are combined to construct the transverse beam density pro_le. TheWS is installed and operated in all circular accelerators of CERN on a dailybasis.
154

High Temperature Gas to Liquid Metal Foam and Wire Mesh Heat Exchangers

Rezaey, Reza 26 November 2012 (has links)
Metal foams and wire meshes are open cell structures with low weight and density, high permeability and high thermal conductivity which make them attractive for a wide range of industrial applications involving fluid flow and heat transfer. In this study, the effect of natural convection, radiation and heat transfer enhancement of metal foams and wire meshes of 10 and 40 PPI (pores per inch) heat exchangers were examined and compared for different heat exchanger orientation, coolant flow rate and atmosphere temperature. Thermal spray coating processes were also used in development of a new class of high temperature stainless steel heat exchangers. Stainless steel wire mesh heat exchangers were prototyped by connecting the tube to the wire mesh using wire arc thermal spray coating. Thermal spray coating provided efficient connections between the wire mesh and the tubes’ outer surface, and has potential to replace expensive brazing or other metal connection techniques.
155

Process Quality Improvement in Thermosonic Wire Bonding

Lee, Jaesik Jay January 2008 (has links)
This thesis demonstrates the feasibility of methods developed to increase the quality of the crescent bond together with the tail bond quality. Low pull force of the crescent bond limits the usage of insulated Au wire in microelectronics assembly. Premature break of the tail which results in the stoppage of the bonding machine is one of obstacles to overcome for Cu wire. The primary focus of this thesis is to understand the tail and crescent bonding process and then to propose methodologies to improve thermosonic wire bonding processes when Cu and insulated Au wires are used. Several series of experiments to investigate the crescent and tail bonding processes are performed on auto bonders. Cu and insulated Au wires with diameters of 25mm are bonded on the diepads of Ag leadframes. For simplicity, wire loops are oriented perpendicular to the ultrasonic direction. It was found that the crescent bond breaking force by pulling the wire loop (pull force) with insulated Au wire is about 80 % of that of bare Au wire. A modification of the crescent bonding process is made to increase the pull force with insulated Au wire. In the modified process, an insulation layer removing stage (cleaning stage) is inserted before the bonding stage. The cleaning stage consists of a scratching motion (shift) toward to the ball bond in combination with ultrasound. Bonds are then made on the fresh diepad with the insulation removed from the contact surface of the insulated Au wire. This process increases the pull force of the crescent bond up to 26% which makes it comparable to the results obtained with bare Au wire. An online tail breaking force measurement method is developed with a proximity sensor between wire clamp and horn. Detailed understanding of tail bond formation is achieved by studying tail bond imprints with scanning electron microscopy and energy dispersive x-ray analysis. Descriptions are given of the dependence of the tail breaking force on the bonding parameters, metallization variation, and cleanliness of the bond pad. Simultaneous optimization with pull force and tail breaking force can optimize the Cu wire bonding process both with high quality and robustness. It is recommended to first carry out conventional pull force optimization followed by a minimization of the bonding force parameter to the lowest value still fulfilling the pull force cpk requirement. The tail bond forms not only under the capillary chamfer, but also under the capillary hole. The tail breaking force includes both the interfacial bond breaking strength and the breaking strength of the thinned portion of the wire that will remain at the substrate as residue. Close investigations of the tail bond imprint with scanning electron microscopy indicate the presence of fractures of the substrate indicating substrate material being picked up by Cu wire tail. Pick up is found on Au and Cu wires, but the amount of pick up is much larger on Cu wire. The effect on the hardness of the subsequently formed Cu free air ball (FAB) as investigated with scanning electron microscopy and micro - hardness test shows that Cu FABs containing Au and Ag pick ups are softer than those without pick up. However, the hardness varies significantly more with Au pick up. The amount of Au pick up is estimated higher than 0.03 % of the subsequently formed FAB volume, exceeding typical impurity and dopant concentrations (0.01 %) added during manufacturing of the wire.
156

Process Quality Improvement in Thermosonic Wire Bonding

Lee, Jaesik Jay January 2008 (has links)
This thesis demonstrates the feasibility of methods developed to increase the quality of the crescent bond together with the tail bond quality. Low pull force of the crescent bond limits the usage of insulated Au wire in microelectronics assembly. Premature break of the tail which results in the stoppage of the bonding machine is one of obstacles to overcome for Cu wire. The primary focus of this thesis is to understand the tail and crescent bonding process and then to propose methodologies to improve thermosonic wire bonding processes when Cu and insulated Au wires are used. Several series of experiments to investigate the crescent and tail bonding processes are performed on auto bonders. Cu and insulated Au wires with diameters of 25mm are bonded on the diepads of Ag leadframes. For simplicity, wire loops are oriented perpendicular to the ultrasonic direction. It was found that the crescent bond breaking force by pulling the wire loop (pull force) with insulated Au wire is about 80 % of that of bare Au wire. A modification of the crescent bonding process is made to increase the pull force with insulated Au wire. In the modified process, an insulation layer removing stage (cleaning stage) is inserted before the bonding stage. The cleaning stage consists of a scratching motion (shift) toward to the ball bond in combination with ultrasound. Bonds are then made on the fresh diepad with the insulation removed from the contact surface of the insulated Au wire. This process increases the pull force of the crescent bond up to 26% which makes it comparable to the results obtained with bare Au wire. An online tail breaking force measurement method is developed with a proximity sensor between wire clamp and horn. Detailed understanding of tail bond formation is achieved by studying tail bond imprints with scanning electron microscopy and energy dispersive x-ray analysis. Descriptions are given of the dependence of the tail breaking force on the bonding parameters, metallization variation, and cleanliness of the bond pad. Simultaneous optimization with pull force and tail breaking force can optimize the Cu wire bonding process both with high quality and robustness. It is recommended to first carry out conventional pull force optimization followed by a minimization of the bonding force parameter to the lowest value still fulfilling the pull force cpk requirement. The tail bond forms not only under the capillary chamfer, but also under the capillary hole. The tail breaking force includes both the interfacial bond breaking strength and the breaking strength of the thinned portion of the wire that will remain at the substrate as residue. Close investigations of the tail bond imprint with scanning electron microscopy indicate the presence of fractures of the substrate indicating substrate material being picked up by Cu wire tail. Pick up is found on Au and Cu wires, but the amount of pick up is much larger on Cu wire. The effect on the hardness of the subsequently formed Cu free air ball (FAB) as investigated with scanning electron microscopy and micro - hardness test shows that Cu FABs containing Au and Ag pick ups are softer than those without pick up. However, the hardness varies significantly more with Au pick up. The amount of Au pick up is estimated higher than 0.03 % of the subsequently formed FAB volume, exceeding typical impurity and dopant concentrations (0.01 %) added during manufacturing of the wire.
157

Thermal Effects on Cu Wire Bonding by Using Finite Element Simulation

Gau, Hua-de 07 September 2010 (has links)
¡@¡@Wire bonding has been used in integrated circuit packaging for many years which has been more full-grown than other bonding methods, and gold wire has been the preferred choice. Because of the rising price of gold every year, copper wire has been increasingly used to replace gold wire. ¡@¡@The main focus of this paper is to simulate 3D copper-Al pad thermosonic wire bonding stage by using 3D finite element method. Firstly, the differences between mechanical analysis (the thermal effect was not considered) and thermo-mechanical coupling analysis from both impact stage and ultrasonic vibration stage, respectively, were compared. Secondly, the differences between copper thermosonic wire bonding analysis and gold thermosonic wire bonding analysis were discussed. Finally, the effects of Al pad thickness variation on the copper thermosonic wire bonding analysis were studied. ¡@¡@Results showed that, due to the mechanical properties will be decreased by thermal effects caused from temperature increasing, the obtained effective stress and efective strain of thermo-mechanical coupling analysis were less than the results obtained from mechanical analysis. The pad plastic defomation in copper thermosonic wire bonding is more critical than gold thermosonic wire bonding. Therefore, copper thermosonic wire bonding will lead to serious pad splashing. Also, quantity of the decreasing of pad plastic deformation was limited by increasing the pad thickness.
158

Experimental study of passive scalar mixing in swirling jet flows

Örlü, Ramis January 2006 (has links)
<p>Despite its importance in various industrial applications there is still a lack of experimental studies on the dynamic and thermal field of swirling jets in the near-field region. The present study is an attempt to close this lack and provide new insights on the effect of rotation on the turbulent mixing of a <i>passive scalar</i>, on turbulence (joint) statistics as well as the turbulence structure.</p><p>Swirl is known to increase the spreading of free turbulent jets and hence to entrain more ambient fluid. Contrary to previous experiments, which leave traces of the swirl generating method especially in the near-field, the swirl was imparted by discharging a slightly heated air flow from an axially rotating and thermally insulated pipe (6 m long, diameter 60 mm). This gives well-defined axisymmetric streamwise and azimuthal velocity distributions as well as a well-defined temperature profile at the jet outlet. The experiments were performed at a <i>Reynolds</i> number of 24000 and a swirl number (ratio between the angular velocity of the pipe wall and the bulk velocity in the pipe) of 0.5.</p><p>By means of a specially designed combined X-wire and cold-wire probe it was possible to simultaneously acquire the instantaneous axial and azimuthal velocity components as well as the temperature and compensate the former against temperature variations. The comparison of the swirling and non-swirling cases clearly indicates a modification of the turbulence structure to that effect that the swirling jet spreads and mixes faster than its non-swirling counterpart. It is also shown that the streamwise velocity and temperature fluctuations are highly correlated and that the addition of swirl drastically increases the streamwise<i> passive scalar</i> flux in the near field.</p>
159

The buying behaviour of farmers in the Eastern Free State when purchasing wire products / du Plessis O.

Du Plessis, Ockert Johannes January 2011 (has links)
The purpose of this study is to assist wire companies to identify buying behaviour amongst consumers of their products. For the purpose of this study the product will be wire products and the specific target market will be farmers in the Eastern Free State. The primary objective of the study is to identify factors that play a role in the buying behaviour of farmers in the Eastern Free State when purchasing wire products. By knowing exactly the buying criteria of wire products amongst farmers and seasonable cycles of purchasing will form the basis of strategic marketing planning. This study was conducted in two phases. Phase one consisted of a literature review and phase two of an empirical research. The empirical research consisted of a quantitative research design; more specifically, descriptive research that employed cross–sectional analysis of the quantitative data collected from a sample by means of a structured questionnaire. The results show that 76% of the respondents are older than 41 years of age. The population for this study is, therefore, a more matured one. Regarding their buying behaviour, the purchase frequency shows that the majority purchase wire products on a monthly basis and 40% on an annual basis. Most of them (78%) purchase their wire products from the co–operative. Wire products are an integral part of farming activities and in general the respondents are very positive about the industry. Most important considerations identified are that the wire industry should keep in touch with its market, never be out of orders, keep up the fast service that is currently provided, and that reputable products should be kept in stock. / Thesis (M.B.A.)--North-West University, Potchefstroom Campus, 2012.
160

The buying behaviour of farmers in the Eastern Free State when purchasing wire products / du Plessis O.

Du Plessis, Ockert Johannes January 2011 (has links)
The purpose of this study is to assist wire companies to identify buying behaviour amongst consumers of their products. For the purpose of this study the product will be wire products and the specific target market will be farmers in the Eastern Free State. The primary objective of the study is to identify factors that play a role in the buying behaviour of farmers in the Eastern Free State when purchasing wire products. By knowing exactly the buying criteria of wire products amongst farmers and seasonable cycles of purchasing will form the basis of strategic marketing planning. This study was conducted in two phases. Phase one consisted of a literature review and phase two of an empirical research. The empirical research consisted of a quantitative research design; more specifically, descriptive research that employed cross–sectional analysis of the quantitative data collected from a sample by means of a structured questionnaire. The results show that 76% of the respondents are older than 41 years of age. The population for this study is, therefore, a more matured one. Regarding their buying behaviour, the purchase frequency shows that the majority purchase wire products on a monthly basis and 40% on an annual basis. Most of them (78%) purchase their wire products from the co–operative. Wire products are an integral part of farming activities and in general the respondents are very positive about the industry. Most important considerations identified are that the wire industry should keep in touch with its market, never be out of orders, keep up the fast service that is currently provided, and that reputable products should be kept in stock. / Thesis (M.B.A.)--North-West University, Potchefstroom Campus, 2012.

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