• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 2905
  • 962
  • 566
  • 396
  • 102
  • 91
  • 75
  • 43
  • 43
  • 43
  • 43
  • 43
  • 41
  • 36
  • 35
  • Tagged with
  • 6282
  • 3453
  • 832
  • 589
  • 495
  • 490
  • 432
  • 427
  • 399
  • 373
  • 355
  • 315
  • 308
  • 301
  • 301
  • 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.
281

Tagged: a case study in documentary ethics.

Donovan, Kay January 2008 (has links)
University of Technology Sydney. Faculty of Humanities and Social Sciences. / The growing concern about the role of ethics in western society has also touched documentary film-making. Yet, since the emergence in the late 1980s of the first journal articles discussing documentary ethics, the theoretical exploration of the key arguments in this field has been fitful. Debates amongst filmmakers about ethics are often immersed in topical discussions of production issues or issues relating to a few controversial films. With the exception of a few insightful works, there is little new analysis or examination devoted to exploring ethics in this discipline. This dissertation adds to the available body of work by examining in depth the ethics encountered in the production of a documentary film, Tagged, with young people, especially the ethics encoded in the aesthetic and discursive elements of the film. Theoretical discussions about ethics range from the analytical focus on the ethics of representation, through the use of subjective modes of expressivity and filmic techniques to epistemological analyses of specific issues such as privacy and the nature of consent that draw on legal and medical models. A study of relevant documentary films reveals the variety of approaches to the moral values reflected in their discourses and visual representations, and a range of authorial voices, heavily influenced by the relationship between filmmakers and subjects and by the production circumstances of each film. In Australia, broadcasters, funding bodies and production companies dominate the documentary film-making environment and their codes, editorial policies and protocols influence the whole sector of documentary filmmaking. By categorizing documentary within the broad scope of factual programming, they reflect an institutional gaze that fails to acknowledge those individuals including children and youth, who participate in its production. Through my examination of ethics in both the theory and practice, I address the relevant question of whether there should be a code of practice for documentary film-making. In focussing on my own ethical position and its translation into practice through the making of Tagged, I explore the ways in which the ethical stance that I established is pivotal to the documentary and represented both in the text and in the pragmatic choices of production. This led me to conclude that the development of an ethical position specific to a current project is an effective focus on the potential ethical conflicts in a production. From this I argue that while a broad code of conduct can provide valuable guidelines, it cannot replace the filmmakers’ investigation of their ethical practice and their establishment of an ethical statement and stance for their films thus creating a platform from which ethical conflicts can be understood and either avoided or resolved.
282

John Dewey and doccumentary [sic] narrative

Mueller, Denis. January 2007 (has links)
Thesis (Ph.D.)--Bowling Green State University, 2007. / Document formatted into pages; contains viii, 110 p. Includes bibliographical references.
283

Synthesis and Characterization of Zr1-xSixN Thin Film Materials

Zhang, Xuefei January 2007 (has links) (PDF)
No description available.
284

Analysis of the processing and characterization of p-type CuScO��� thin films

Nielsen, Benjamin C. 12 February 2004 (has links)
Graduation date: 2004
285

Fabrication of ultrathin SiC film using grafted poly(methylsilane)

Lertwiwattrakul, Wimol 06 December 2000 (has links)
��-SiC is a semiconductor for high temperature devices, which exhibits several outstanding properties such as high thermal stability, good chemical stability and wide band gap. There is a possibility of fabricating a crack-free ultrathin SiC film on silicon wafers by pyrolysis of polymethylsilane (PMS) film. This study looks into the possibility, as the first phase, to modify the surface of silicon and graft PMS onto the surface. A new technique reported in this thesis consists of a surface modification with trimethoxysilylpropene (TSP) followed by the surface attachment of dichloromethylsilane (DMS) in the presence of a platinum catalyst, which acts as the first unit for grafting PMS molecules by the sodium polycondensation of additional DMS monomers. The grafted PMS polymers would serve as the pyrolytic precursor to be converted into thin layers of SiC. Surface analysis of these films on silicon wafers by X-ray photoelectron spectroscopy (XPS) indicated that the silicon surface was successfully modified with TSP, attached with DMS, and finally grafted with PMS. It was also confirmed by powder X-ray diffraction (XRD) that PMS formed simultaneously in the bulk solution was converted into SiC by pyrolysis at temperatures above 1100��C under Ar atmosphere. Extended studies showed that the PMS-derived coatings, formed in an Ar stream containing 1% H��� at 400��C, were significantly oxidized, and further heating to 700��C yielded a Si0��� layer with graphitic carbon. The intensity of the graphite peak decreased with an increase in the pyrolysis temperature. Based on these preliminary studies towards the second phase, i.e. the pyrolysis of PMS to SiC, the need for further research to eliminate the oxidation source(s) is strongly suggested. / Graduation date: 2001
286

A study of ZnS:Mn electroluminescent phosphors grown by halide transport chemical vapor deposition

Chen, Chia-Jen 02 July 1997 (has links)
A low pressure halide transport chemical vapor deposition (HTCVD) system to grow ZnS:Mn electroluminescent phosphors is characterized. Reactor parameters such as gas composition, gas flow rate, and source and substrate temperature are investigated. Crystal structure is investigated using x-ray diffraction, electron spin resonance, and transmission electron microscopy. Chemical characterization includes electron microprobe and Auger electron spectroscopy. Double-insulating alternating current thin film electroluminescent devices are constructed around the HTCVD phosphors. The devices are studied using electroluminescence (brightness-voltage), photoluminescence and electrical characterization. The luminescent properties of films with a (002) preferred orientation are studied. A maximum electroluminescent brightness of 1475 cd/m�� is achieved. The photoluminescence (PL) of ZnS:Mn films grown at different substrate temperatures is compared. The intensity correlates to Mn concentration. Red emission is seen in films grown at lower substrate temperature which have low Mn concentration. Mechanisms proposed in the literature cannot explain the red emission. A blue PL ZnS film intentionally doped with chlorine is achieved. This blue emission is associated with self-activated (SA) emission. Hexagonal and cubic thin-film ZnS:Mn electroluminescent phosphors are grown by HTCVD. Processing conditions, most notably introduction of a H���S ambient, lead to a change in the preferred orientation and phase of the polycrystalline thin film. In addition to the commonly reported growth along the closest packed plane [(111) for cubic crystal structure or (002) for hexagonal], thin films have been grown along the less dense cubic (311) direction. The electrical characterization of ZnS:Mn ACTFEL devices with phosphors having different structure and preferred orientation is studied. A comparison of different preferred orientations and structures on conduction charge, obtained by internal charge-phosphor field (Q-F[subscript]p), is performed. When grown in the (311) direction, the conduction charge of a ZnS:Mn ACTFEL device increases from 2.3 ��C/cm�� to 5.0 ��C/cm��. Moreover, the leakage charge, Q[subscript]l[subscript]e[subscript]a[subscript]k, of the (311) HTCVD films is small compared to other devices. / Graduation date: 1998
287

Thin film multilayer superconductors and the proximity effect

McLaughlin, Kevin M. 16 March 1999 (has links)
Recent superconducting thin films studies have attempted to create pure metal layer films of Niobium and Titanium with the same properties of superconducting NbTi wire used in industry. These studies have all reported depression of the superconducting properties of the pure metal films which has been attributed to the proximity effect. The purpose of this research project was to construct several NbTi films composed of alloyed layers to overcome the proximity depression of superconducting properties. These films are unique in that they are the only films with both alloyed Nb/Ti superconducting and normal layers reported in the literature. Films with several different compositions and bilayer geometries were designed, constructed and their superconducting properties characterized. The films were created by the RF sputtering of alloyed targets at ambient temperatures. Characterization of the composition of the films was performed by microprobe analysis at two different electron beam voltages. A simulation of the electron beam excitation volume of the microprobe was performed to determine the difference in the two analyses and to determine whether the substrate would be found upon microprobe examination. X-ray diffraction was utilized to determine the bilayer spacing and to give a qualitative understanding of the alignment of the film microstructures. The critical temperature and upper critical magnetic field were measured to determine the superconducting properties and the extent of the proximity effect in the films. The microprobe analysis found most films to be very pure alloys except for films 6001, 6002, 6003(1) in which there were between 1-8 wt% of impurities. All films contained compositional variations on the order of 10 wt% from the design values. X-ray diffraction indicated agreement with the designed bilayer spacing in all films but 6003(2), 6005(1), and 6005(2) which had bilayer periods larger than originally designed. The proximity effect was not observed in any of the film's superconducting properties examined. T[subscript]c and H[subscript]c��� properties for the films without impurities had properties equal to that of bulk Nb/47wt% Ti. Films 6001, 6003(1) had depressed T[subscript]c and H[subscript]c��� values which were attributed to their impurity contamination. The low Ti composition in many of the films points to the inaccuracy of the deposition parameters when the films were first processed. The lack of T[subscript]c and H[subscript]c��� depression normally seen in other film studies with bilayer periods between 10-30 nm demonstrates that alloyed layers should be used to overcome the proximity effect in multilayer thin film superconductor studies. Overcoming the proximity effect should translate into a better understanding of flux pinning mechanisms in the material and increased superconducting critical currents in these films. / Graduation date: 1999
288

Thermal characterization technique for thin dielectric films

Indermuehle, Scott W. 14 April 1998 (has links)
A phase sensitive measurement technique that permits the simultaneous determination of two independent thermal properties of thin dielectric films is presented. Applying the technique results in a film's thermal diffusivity and effusivity, from which the thermal conductivity and specific heat can be calculated. The technique involves measuring a specimen's front surface temperature response to a periodic heating signal. The heating signal is produced by passing current through a thin layer of nichrome that is deposited on the specimen's surface, and the temperature response is measured with a HgCdTe infrared detector operating at 77 K. The signal that is produced by the infrared detector is first conditioned, and then sent to a lock-in amplifier. The lock-in is used to extract the phase shift present between the temperature and heating signal through a frequency range of 500 Hz-20 kHz. The corresponding phase data is fit to an analytical model using thermal diffusivity and effusivity as fitting parameters. The method has been applied effectively to 1.72 ��m films of Si0��� that have been thermally grown on a silicon substrate. Thermal properties have been obtained through a temperature range of 25��C-300��C. One unanticipated outcome stemming from analysis of the experimental data is the ability to extract both the thermal conductivity and specific heat of a thin film from phase information alone, with no need for signal magnitude. This improves the overall utility of the measurement process and provides a 'clean', direct path with fewer assumptions between data and final results. The thermal properties determined so far with this method are consistent with past work on Si0��� films. / Graduation date: 1998
289

Microstructures and properties of Nb/Ti multilayered thin films

Faase, Kenneth James 19 September 1996 (has links)
Graduation date: 1997
290

Alternative realities/The multiverse a metaphysical conundrum /

Wynn, Freda A. January 2005 (has links)
Thesis (M.A.)--Georgia State University, 2005. / Title from title screen. Kay Beck, committee chair; Edward J. Friedman, Kathryn H. Fuller, committee members. Electronic text (124 p.) : digital, PDF file. Description based on contents viewed Apr. 17, 2007. Includes bibliographical references (p. 108-124).

Page generated in 0.0768 seconds