• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 4
  • Tagged with
  • 4
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 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

Analysis of downhole drilling vibrations : case studies of Manifa and Karan fields in Saudi Arabia

Alabdullatif, Ziad Abdullrahman 05 October 2011 (has links)
Downhole vibrations lead to downhole failures and decrease the rate of penetration (ROP). The bottom hole assembly (BHA) static and dynamic design is a key factor in optimizing drilling operations. The BHA should be designed to minimize the vibration levels in the axial, lateral, and torsional directions. This would be achieved by avoiding rotating the drillstring in the speeds that are nearby the natural frequency of BHA. The complexity associated with current BHA components requires using advanced computational tools that are capable of solving complex and time-consuming equations. Finite Element Analysis (FEA) is the most used technique in analyzing vibration behavior of the drillstring by mesh discretizing of a continuous body into small elements. This thesis will study the dynamic behavior of different BHA designs for Manifa and Karan fields of Saudi Aramco to optimize the drilling operations. The FEA software that will be used to conduct these studies is called Vibrascope™, which was developed by NOV. The software will determine the critical speeds of the drillstring that should be avoided to prevent resonance of the BHA, which will lead to severe downhole vibration. / text
2

Failure and Degradation Modes of PV modules in a Hot Dry Climate: Results after 16 years of field exposure

January 2013 (has links)
abstract: This study evaluates two 16 year old photovoltaic power (PV) plants to ascertain degradation rates and various failure modes which occur in a "hot-dry" climate. The data obtained from this study can be used by module manufacturers in determining the warranty limits of their modules and also by banks, investors, project developers and users in determining appropriate financing or decommissioning models. In addition, the data obtained in this study will be helpful in selecting appropriate accelerated stress tests which would replicate the field failures for the new modules and would predict the lifetime for new PV modules. The two power plants referred to as Site 4A and -4B with (1512 modules each) were initially installed on a single axis tracking system in Gilbert, Arizona for the first seven years and have been operating at their current location in Mesa, Arizona for the last nine years at fixed horizontal tilt Both sites experience hot-dry desert climate. Average degradation rate is 0.85%/year for the best modules and 1.1%/year for all the modules (excluding the safety failed modules). Primary safety failure mode is the backsheet delamination though it is small (less than 1.7%). Primary degradation mode and reliability failure mode may potentially be attributed to encapsulant browning leading to transmittance/current loss and thermo-mechanical solder bond fatigue (cell-ribbon and ribbon-ribbon) leading to series resistance increase. Average soiling loss of horizontal tilt based modules is 11.1%. About 0.5-1.7% of the modules qualify for the safety returns under the typical 20/20 warranty terms, 73-76% of the modules qualify for the warranty claims under the typical 20/20 power warranty terms and 24-26% of the modules are meeting the typical 20/20 power warranty terms. / Dissertation/Thesis / M.S.Tech Engineering 2013
3

Beyond appearances : transnationalism and representation of women in Bollywood cinema

Ayob, Asma 11 1900 (has links)
Bollywood cinema continues to evolve. As a result, it has become a transnational/cultural role player for Indian audiences worldwide. There has always been a strong link between Bollywood cinema and Indian society. Over the years, it has contributed to the dialogue on women’s roles and position in Indian society. In the past, Bollywood filmmakers were faithful to representations of women who were bound by patriarchal structures in the sense that they were expected to be loyal to ancient Indian traditions and belief-systems. Based on the increase in Indian migration, contemporary Bollywood filmmakers are now catering to the demands of the Indian diaspora and therefore, a more global market. The impact of transnationalism on the representation of women in many Bollywood films has further added to the creation of open spaces for the Bollywood heroine. In this regard, the films of auteur director Karan Johar are valuable because they provide audiences with material that suggests re-thinking patriarchal structures in a transnational world. This study will examine the representation of women in three selected films of Johar within the framework of feminist theory (Indian context). The impact that transnationalism has had on the Indian diaspora and the manner in which this translates into the narratives and representations of female characters in Bollywood films will be discussed. / Afrikaans & Theory of Literature / D. Litt. et Phil. (Theory of Literature)
4

Beyond appearances : transnationalism and representation of women in Bollywood cinema

Ayob, Asma 11 1900 (has links)
Bollywood cinema continues to evolve. As a result, it has become a transnational/cultural role player for Indian audiences worldwide. There has always been a strong link between Bollywood cinema and Indian society. Over the years, it has contributed to the dialogue on women’s roles and position in Indian society. In the past, Bollywood filmmakers were faithful to representations of women who were bound by patriarchal structures in the sense that they were expected to be loyal to ancient Indian traditions and belief-systems. Based on the increase in Indian migration, contemporary Bollywood filmmakers are now catering to the demands of the Indian diaspora and therefore, a more global market. The impact of transnationalism on the representation of women in many Bollywood films has further added to the creation of open spaces for the Bollywood heroine. In this regard, the films of auteur director Karan Johar are valuable because they provide audiences with material that suggests re-thinking patriarchal structures in a transnational world. This study will examine the representation of women in three selected films of Johar within the framework of feminist theory (Indian context). The impact that transnationalism has had on the Indian diaspora and the manner in which this translates into the narratives and representations of female characters in Bollywood films will be discussed. / Afrikaans and Theory of Literature / D. Litt. et Phil. (Theory of Literature)

Page generated in 0.0467 seconds