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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.
121

Drapering av en illusion : En komparativ studie med utgångspunkt i fotografierna av Leila Khaled och Shirin Neshat

Ragnestam, Maria January 2007 (has links)
<p>The aim of this paper is to perform a comparative study between the photography’s of Leila Khaled and Shirin Neshat in order to observe if the woman are able to recede from an conventional formation to become the bearer of the veil and not only reduced to that which</p><p>needs to be concealed. From a feministic perspective I have observed how the symbolic of the veil moulds the woman and how the woman in her context moulds the veil.</p><p>In the description of the news photography of Khaled and the art photography produced by Neshat the mechanisms that lies as a foundation for the modelling of the portraits becomes</p><p>the essays primary entrance. Mechanisms that evolve around the creation of the woman as aconcept, a subject shaped for being looked at and the woman’s self-image through others.</p><p>The textual discourse is visually enhanced through a comparative picture material visually enhanced and explained through photographs by the contemporary artist photographers Cindy Sherman, Catherine Opie, Laurie Simmons, Robert Mapplethorpe and Elin Berge. The visual comparative material also interacts with the essays primary picture material and further expresses the oppression of the woman that occurs irrespective of culture through a patriarch cal gender system.</p>
122

Drapering av en illusion : En komparativ studie med utgångspunkt i fotografierna av Leila Khaled och Shirin Neshat

Ragnestam, Maria January 2007 (has links)
The aim of this paper is to perform a comparative study between the photography’s of Leila Khaled and Shirin Neshat in order to observe if the woman are able to recede from an conventional formation to become the bearer of the veil and not only reduced to that which needs to be concealed. From a feministic perspective I have observed how the symbolic of the veil moulds the woman and how the woman in her context moulds the veil. In the description of the news photography of Khaled and the art photography produced by Neshat the mechanisms that lies as a foundation for the modelling of the portraits becomes the essays primary entrance. Mechanisms that evolve around the creation of the woman as aconcept, a subject shaped for being looked at and the woman’s self-image through others. The textual discourse is visually enhanced through a comparative picture material visually enhanced and explained through photographs by the contemporary artist photographers Cindy Sherman, Catherine Opie, Laurie Simmons, Robert Mapplethorpe and Elin Berge. The visual comparative material also interacts with the essays primary picture material and further expresses the oppression of the woman that occurs irrespective of culture through a patriarch cal gender system.
123

Finite Element Simulation of the Atomization of Liquid Membrane in Gene Gun

Lin, Wei-ting 14 August 2012 (has links)
In recent years, with advances in medical treatment, the demand of medical beauty market has increased year by year. With the continuous innovation of nanotechnology, medical technology with nanometer level is becoming the one of the most important issue of the development of medical biotechnology in recent years. In order to make the products effective, the products have to be transported into the human skin. In traditional medical treatments, the devices of contacting type or invading type were adopted, and might cause some infected problems. To avoid these situations, some medical companies have developing the non-contact type device¡Ð gene gun. This device use nitrogen as motive force to atomize the thin film of the injection products, then delivering these products to derma. This research utilizes computational fluid dynamics software to build the FEM simulation model of Venturi tube inside of a gene gun. Then, analyzing the speed and atomization of fluid which inside or outside of Venturi tube. A FEM simulated mechanism for the atomization of multiphase flow was constructed in this research successfully. The effects of variations of some geometric parameters of Venturi tube on the atomization of thin film were studied also. The obtained results can shorten cost and time in relevant development.
124

The Study and Fabrication of High Efficiency Yb:YAG Ring Laser

Cheng, Kuo-Wei 21 July 2005 (has links)
In the past three decades, Nd:YAG has been the dominating high power solid-state laser gain medium. Compared with Nd:YAG, Yb:YAG has lower quantum defects which produces less heat so that it can reduce thermo-optical deformation. In addition, the achieved doping concentration can be 100%, and the absorption FWHM at 941 nm is 18 nm. Based on above listed advantages, Yb:YAG has the potential to replace Nd:YAG. Using Yb:YAG as the laser gain medium in reentrant two-mirror laser cavity, we have succeeded in Yb:YAG ring laser and all the intracavity elements are coated by our electron gun deposition system. The main purpose of my research is to continue the previous result (slope efficiency: 20.1%), and further increasing the slope efficiency of our ring cavity with different round-trip transmittance of couplers. Besides, we measured and analyzed the polarization of the planar and non-planar ring cavities. At present, the highest slope efficiency we achieved is 38.9% with a round-trip transmittance of 16.4%.
125

Gas gun studies of armature-rail interface wear effects

Jackson, Tyler Andrew 18 November 2010 (has links)
The objective of this work has been to investigate the applicability of the gas gun to study the armature-rail interface wear characteristics relevant to rail gun operations. The approach involved developing constitutive models for armature materials (aluminum 6061) as well as oxygen-free high-thermal conductivity copper as the rail material. Taylor rod-on-anvil impact experiments were performed to validate the accuracy of constitutive strength models by correlating predictions of dynamic simulations in ANSYS AUTODYN with experimental observations. An optical comparator was used to discretize the cross sectional deformation profile of each rod-shaped sample. Parameters of the Johnson-Cook strength model were adjusted for each material to match deformation profiles obtained from simulations with profiles obtained from impact experiments. The fitted Johnson-Cook model parameters for each material were able to give overall deformed length and diameter values within 2% of the experimentally observed data. Additional simulations were then used with the validated strength model parameters to design the geometry involving cylindrical rods of armature material accelerated through a concentric cylindrical extrusion die made of copper, to emulate the interface wear effects produced in a rail gun operation. Experiments were conducted using this geometry and employing both the 7.62mm and 80mm diameter gas guns. Microstructural analysis was conducted on interfaces of the recovered samples from both designs. Hardness measurements were also performed along the interface layer to evaluate the structure formation due to solid-state wear or melt formation. The stress and strain conditions resulting in the observed microstructural effects were correlated with predictions from numerical simulations performed using the validated material models. The overall results illustrate that the stress-strain conditions produced during acceleration of Al through hollow concentric copper extrusion die, result in interface deformation and wear characteristics that are influenced by velocity. At velocities (less than 800m/s), interface wear leads to formation of layer dominated by solid-state alloying of Cu and Al, while higher velocities produce a melted and re-solidified aluminum layer. Hence, use of different armature (Al-based) and rail (Cu-based) materials can be evaluated with the gas-gun set-up employed in the current work to study the effects of interface wear ranging from formation melt layer to solid-state alloying as a function of material properties and velocity.
126

Korean and American monastic practices : a comparative case study /

Moon, Simon Young-Suck. January 1900 (has links)
Diss.--Graduate centre for the study of religion--Toronto--University, 1996. / Bibliogr. p. 222-236. Index.
127

Evaluating the Effectiveness of a Teaching Package Utilizing Behavioral Skills Training and In Situ Training to Teach Gun Safety Skills in a Preschool Classroom

Hanratty, Laura Ann 01 January 2011 (has links)
There are a number of different safety threats that children face in their lives. One infrequent, but highly dangerous situation a child can face is finding a firearm. Hundreds of children are injured or killed by firearms each year. Fortunately, behavioral skills training (BST) and in situ training (IST) are effective approaches for teaching a number of different skills, including safety skills. The purpose of this study was to evaluate a teaching package for preschool teachers to learn to conduct BST to teach safety skills. A multiple baseline across subjects design was used to evaluate the effectiveness of this teaching package implemented by the teacher with seven preschoolers. Five children demonstrated the skills following in situ training and additional reinforcement or time out. Two children did not complete the study.
128

A Neutral Beam Probe for the Helimak plasma experiment

Garcia de Gorordo, Alvaro 15 July 2013 (has links)
A Neutral Beam Probe (NBP) was developed for studying the Texas Helimak plasma experiment. The probe consisted of a beam of neutral sodium atoms that were injected into the magnetized plasma of the Helimak. After some fraction of the atoms underwent electron impact ionization, the resulting ion beam followed a path to an energy analyzer where the change of energy was detected along with the total ion current. The measurement of the change of energy implies a change of potential energy at the point of ionization since all the neutral beam particles enter the plasma with a well determined energy. The total current detected at the energy analyzer also implies a rate of electron impact ionization, which in turn implies an electron density and temperature. The NBP was developed based on the Elmo Bumpy Torus (EBT) Heavy Ion Beam Probe (HIBP), which was operated at Oak Ridge National Labs. In fact, the majority of the equipment that was used in this experiment was taken from that HIBP, and some of it was rebuilt. We generated an estimate of the radial electric field in the Helimak along with an estimate of density changes as a result of biasing experiments. Interestingly, when a bias voltage was applied inside the Helimak, the radial electric field did not change significantly at the sample region, but the electron density did vary. The probe data taken by the Helimak team agree with the density changes. The electric field derived from Langmuir probes is not trivial (especially in plasmas with flows) and was not computed for this thesis. / text
129

Vibration level characterization from a needle gun used on U.S. naval vessels

Dunn, Scott E 01 June 2006 (has links)
United States (U.S.) Navy sailors are exposed to a very large number of hazards, both chemical and physical. Occupational vibration from pneumatic air tools is one of the potential exposure hazards. There are very limited data as to the exposures to one type of tool, a needle gun or needle scaler, used by the sailors.The purpose of this study was to characterize the vibration levels generated by a needle gun used in the U.S. Navy. The design of the study evaluated the difference pressure had on the acceleration levels generated from the needle scaler. Five subjects were used in the evaluation of the tool. Each subject was required to hold the tool for twenty seconds activated without contact and activated on a surface and at two different pressures, 60 and 80 pound per square inch (psi). Each subject repeated each of the conditions three times for a total of 12 measurements. Each subject was also required to hold the tool in hand without the tool activated. The measurements were collected from an accelerometer on the needle gun following ISO 5349-1:2001 and ISO 5349-2:2001 methods. Significant differences were observed individually in pressure (p<0.0001), contact (p<0.0001)), and subjects (p<0.001). In addition, there was a significant interaction between contact and pressure (p<0.001). It was concluded that U.S. Navy sailors are not likely at significant risk to Hand-Arm Vibration Syndrome for lifetime exposures to hand transmitted vibration.
130

Effect of electro-mechanical loading in metallic conductors

Gallo, Federico Guido 09 February 2011 (has links)
The development of high powered electro-magnetic devices has generated interest in the effect of combined electromagnetic and mechanical loading of such structures. Materials used in high-current applications – aluminum alloys and copper – are subjected to heat pulses of short duration (in the range of a few hundred microseconds to a few milliseconds); immediately following or along with such heat pulses, these materials are also subjected to large mechanical forces. In previous work reported in the literature, ejection of material from the vicinity of preexisting defects such as cracks, notches or discontinuities have been observed resulting from short-duration high-intensity current pulses; after a series of pulses, permanent deformation and weakening of intact material has also been reported. But a lack of complete understanding of the effects of short duration current pulses hinders the assessment of the reliability of such conductors in high energy applications. Therefore, an investigation was undertaken to examine the behavior of electromagnetically and mechanically loaded conductors. This work investigates the effects of short-duration, high-current-density pulses in combination with viii mechanical loading. The aim is to develop a theoretical model to describe the resulting mechanical response. The model is to provide a characterization of the possible effects of thermally-induced plastic strains on metals loaded beyond or just below their yield strength or below the critical stress intensity factor. In the experiments reported here, two types of specimens, undamaged and damaged, were subjected to combined electromechanical loads. Undamaged specimens were used to observe thermally-induced plastic strains - strains not caused by an increase in mechanical loading, but rather resulting from the reduction of yield strength and post-yield stiffness due to the increase in temperature. The experiments were conducted such that it would be possible to develop a model that would conclusively account for the observed material behavior. The second sets of specimens were weakened a priori by the introduction of a crack in order to study the influence of such crack-like defects on the electrical and mechanical fields, and to produce a safe design envelope with respect to the loading conditions. Failure was found to occur due to melting triggered by joule heating; a quantitative criterion based on current concentration and heat accumulation near the crack tip has been developed based on these experimental results. / text

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