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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

Development of a portable optical sensor for detection of micro-discharges in SF←6 switchgear systems

Mufti, Anwar Hassan Ali January 1987 (has links)
No description available.
2

Comparison of conventional light-framed wood construction and structural insulated panels

Ledford, Bradley T. January 1900 (has links)
Master of Science / Department of Architectural Engineering and Construction Science / Sutton F. Stephens / Conventional wood framing, also known as stick framing, has been around for hundreds of years. It is an easy, effective method for building new houses and small commercial projects. However, it may no longer the best option for new construction. The development of Structural Insulated Panels (SIPs) began over 70 years ago at the United States Forest Products Laboratory in Wisconsin. Scientists believed that plywood sheathing alone could provide adequate strength to support the loads a structure encounters. Over the years, SIPs have evolved to what they are today: a rigid insulation foam core sandwiched between two skins, often made of oriented strand boards (OSB). Compared to stick framing, SIPs are faster to erect in the field and also provide more strength to resist most loads; they are better with axial and transverse loads. Stick framing can be built more robust to resist in-plane shear loads. The quality of the material of SIPs also means better quality construction. The insulating values SIPs provide are far superior to that of fiberglass insulation used in stick framing, saving money for the owner as well as energy from natural resources. Not only do they provide better thermal protection, but they are also better for the environment because of manufacturing processes and construction practices. When it comes to other issues such as fire, smoke, termites, and ventilation, SIPs are no worse than stick framing. SIPs follow the same steps for construction used in stick framing with, perhaps a little more care needed to insure proper ventilation. SIPs have proven themselves in the laboratory and in the real world. SIPs should be considered more often as an option, replacing stick framing for the major structure elements and insulation for new buildings.
3

IGBT design, modelling and novel devices

Hsieh, Pei-Shan January 2015 (has links)
No description available.
4

LIGBT design, physics and modelling

Camuso, Gianluca January 2015 (has links)
No description available.
5

Load-response and the effect of de-bonding on structural insulated panels performance

Delijani, Farhoud 21 June 2016 (has links)
Series of full-scale tests were conducted on polyurethane foam-core Structural Insulated Panels (PUR SIPs) to study the load response and creep behavior of such panels. The load response of PUR SIPs was compared with conventional stud wall panels. The effects of de-bonding between the foam-core and the OSB face-sheets were also studied to understand the effects of such change on the overall performance of PUR SIPs. At last, computer modelling was employed to simulate and predict the behavior of PUR SIPs in different loading orientations and dis-bond ratios. It was found that PUR SIPs can outperform conventional stud-wall panels in every aspect. In the case of 165 mm (6.5 in.) thick PUR SIPs, 33% dis-bond between the PUR foam-core and the OSB face-sheets caused an average of 64% reduction in ‘axial load’ capacity, an average of 75.8% reduction in ‘transverse load’ capacity, and an average of 7.9% reduction in ‘racking load’ capacity of the panels compared to brand new fully-bonded SIPs. It was also found that 33% dis-bond in 165 mm (6.5 in.) thick PUR SIPs has minimal effect on the racking load capacity of the panels. In the case of 114 mm (4.5 in.) thick PUR SIPs, 33% dis-bond be-tween the PUR foam-core and the OSB face-sheets caused an average of 63.3% reduction in ‘axial load’ capacity, an average of 79% reduction in ‘transverse load’ capacity, and an average of 29% increase in ‘racking load’ capacity of the panels compared to brand new fully-bonded SIPs. All tested panels satisfied the code requirements for the creep deflections (span/180) and they fully rebounded to their initial estate, 90 days after removal of the simulated snow loads. It was also found that weathering has minimal effect on the bond between the face-sheets and the PUR foam. After computer simulations of fully-bonded and dis-bonded PUR SIPs in two different thicknesses, it was found that SOLIDWORKS simulation software is a useful tool to predict the load response of PUR SIPs only when fully-bonded panels are exposed to transverse load orientation regardless of the thickness of the panel. In general, available Canadian and American standards were followed in this study. Where applicable, standards were adopted from other material testing methods for testing PUR SIPs. It is believed that this independent research has addressed most frequently ex-pressed concerns regarding the use and application of structural insulated panels such as de-bonding issues and creep behavior and their relationship to durability. The hope is that is research help increase the use and application of SIPs in green, high-performance, light-frame building construction in Canada. / October 2016
6

Controlled IGBT switching for power electronics building block

Yang, Xin January 2014 (has links)
No description available.
7

Ueber die mechanische Auffassung elektromagnetischer Erscheinungen in Isolatoren und Halbleitern

Silberstein, Ludwig. January 1900 (has links)
Inaug.-Diss. (Ph. D.)--Friedrich-Wilhelms-Universität zu Berlin, 1894. / Includes bibliographical references.
8

Ueber die mechanische Auffassung elektromagnetischer Erscheinungen in Isolatoren und Halbleitern

Silberstein, Ludwig. January 1900 (has links)
Inaug.-Diss. (Ph. D.)--Friedrich-Wilhelms-Universität zu Berlin, 1894. / Includes bibliographical references.
9

Development of the Selection Procedure of an Insulating Foam for Its Application in Gas Insulated Transmission Lines, Demonstrated Using Syntactic Foam

January 2014 (has links)
abstract: Due to increasing integration of renewable resources in the power grid, an efficient high power transmission system is needed in the near future to transfer energy from remote locations to the load centers. Gas Insulated Transmission Line (GIL) is a specialized high power transmission system, designed by Siemens, for applications requiring direct burial or vertical installation of the transmission line. GIL uses SF6 as an insulating medium. Due to unavoidable gas leakages and high global warming potential of SF6, there is a need to replace this insulating gas by some other possible alternative. Insulating foam materials are characterized by excellent dielectric properties as well as their reduced weight. These materials can find their application in GIL as high voltage insulators. Syntactic foam is a polymer based insulating foam. It consists of a large number of microspheres embedded in a polymer matrix. The work in this thesis deals with the development of the selection proce-dure for an insulating foam for its application in GIL. All the steps in the process are demonstrated considering syntactic foam as an insulator. As the first step of the procedure, a small representative model of the insulating foam is built in COMSOL Multiphysics software with the help of AutoCAD and Excel VBA to analyze electric field distribution for the application of GIL. The effect of the presence of metal particles on the electric field distribution is also observed. The AC voltage withstand test is performed on the insulating foam samples according to the IEEE standards. The effect of the insulating foam on electrical parameters as well as transmission characteristics of the line is analyzed as the last part of the thesis. The results from all the simulations and AC voltage withstand test are ob-served to predict the suitability of the syntactic foam as an insulator in GIL. / Dissertation/Thesis / Masters Thesis Electrical Engineering 2014
10

Monotonic and Cyclic Performance of Structurally Insulated Panel Shear Walls

Jamison, Jared Bernard Jr. 22 December 1997 (has links)
The majority of residential construction and a significant portion of light commercial and industrial construction has been, and will continue to be light-framed timber construction. In recent years, innovations have surfaced to improve upon light-framed construction. Structurally insulated panels (SIPS) are gaining popularity due to their superior energy efficiency and ease of construction. Light-framed timber construction has proven to be trustworthy in high-wind and seismic regions due to its lightweight construction and numerous redundancies. Shear walls, along with floor and roof diaphragms, resist lateral loads in a timber structure. In the past, research has focused on the static racking performance of light-framed shear walls. More recently, research has been focused on the cyclic and dynamic performance of shear walls. To the author's knowledge, no other research is reported in the literature on the cyclic performance of SIPS shear walls. It is important to understand and quantify the monotonic and cyclic response of shear walls. In this study, twenty-three full-scale shear walls were tested under monotonic loading and sequential phased displacement cyclic loading. Four different wall configurations were examined. Monotonic and cyclic performance of the shear walls and monotonic and cyclic testing procedures are compared. Response of SIPS shear walls is also compared to the response of light-framed shear walls based on capacity, stiffness, ductility, energy dissipation, damping characteristics, and overall behavior. Results of this study will provide useful information regarding the performance of SIPS shear walls and similar systems subjected to static, cyclic, and dynamic lateral loads. / Master of Science

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