• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 119
  • 62
  • 27
  • 18
  • 11
  • 9
  • 5
  • 3
  • 2
  • 2
  • 2
  • 1
  • 1
  • Tagged with
  • 282
  • 70
  • 44
  • 43
  • 40
  • 32
  • 29
  • 28
  • 27
  • 26
  • 25
  • 23
  • 22
  • 18
  • 17
  • 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.
131

Factors governing marble lightness in peripheral alteration haloes around carbonate-hosted Zn-Pb-Ag-(Cu-Au) deposits, Garpenberg, Sweden

Eriksson, Marcus January 2020 (has links)
A Master thesis about the Garpenberg deposit located in Bergslagen, a lithotectonic domain, with a mining history that might date back as far as 350 BC. Marble- and skarn-hosted sulfide deposits are found in the area, which creates the opportunity to mine both limestone and sulfidic ore in a single mine. Garpenberg is such a location hence this thesis, which aims to quantify the factors governing spectrophotometric lightness in marble at the Dammjön ore body. The work is mainly based on five drill cores which were logged and sampled. A total of twenty-seven samples were characterized using lithogeochemical analysis and thin-section analysis. The amount of Acid Insoluble Residue (AIR), magnetic minerals and the spectrophotometric lightness were determined for the same samples. The calcite marble was divided into seven different varieties; 1) calcite marble breccia, 2) light, 3) grey, 4) green, 5) banded salmon pink, 6) ophicalcite and 7) spotted calcite marble. The dolomite marble is white to grey in color and skarn minerals are common and varies between 5-20 vol.%. Grey and light calcite marble are the varieties with the highest spectrophotometric lightness, and it could be shown that the lightness increases with a decreasing amount of titanium, aluminum and zirconium which are chemical proxies for mineralogical impurities of originally volcaniclastic origin. High-quality calcite marble is a potentially economic by-product at the Garpenberg mine, the lightest samples are nearly as light as the light standard used during analysis (92.45 out of 100%). The lightest marble is also the chemically most pure which means that the calcium oxide (CaO) and total-carbon content are high. Key geological factors detrimental to lightness and purity are the primary composition, which is determined by the admixture of volcaniclastic material in the limestone precursor. Hydrothermal alteration with the addition of silicates, sulfides and oxides forms a halo around the massive sulfide lenses. Dolomite marble, which is more proximal to ore, is richer in manganese and sulfides, and not as light as the calcite marble at Dammsjön.
132

Overexpression of CuZnSOD in Coronary Vascular Cells Attenuates Myocardial Ischemia/Reperfusion Injury

Chen, Zhongyi, Oberley, Terry D., Ho, Ye Shih, Chua, Chu C., Siu, Brian, Hamdy, Ronald C., Epstein, Charles J., Chua, Balvin H.L. 14 October 2000 (has links)
Superoxide dismutase scavenges oxygen radicals, which have been implicated in ischemia/reperfusion (I/R) injury in the heart. Our experiments were designed to study the effect of a moderate increase of copper/zinc superoxide dismutase (CuZnSOD) on myocardial I/R injury in TgN(SOD1)3Cje transgenic mice. A species of 0.8 kb human CuZnSOD mRNA was expressed, and a 273% increase in CuZnSOD activity was detected in the hearts of transgenic mice with no changes in the activities of other antioxidant enzymes. Furthermore, immunoblot analysis revealed no changes in the levels of HSP-70 or HSP-25 levels. Immunocytochemical study indicated that there was increased labeling of CuZnSOD in the cytosolic fractions of both endothelial cells and smooth muscle cells, but not in the myocytes of the hearts from transgenic mice. When these hearts were perfused as Langendorff preparations for 45 min after 35 min of global ischemia, the functional recovery of the hearts, expressed as heart rate x LVDP, was 48 ± 3% in the transgenic hearts as compared to 30 ± 5% in the nontransgenic hearts (p < .05). The improved cardiac function was accompanied by a significant reduction in lactate dehydrogenase release from the transgenic hearts. Our results demonstrate that overexpression of CuZnSOD in coronary vascular cells renders the heart more resistant to I/R injury.
133

Studies on Structures and Functions of Vitamin B[6] Degrading Enzymes / ビタミンB[6]分解酵素群の構造と機能に関する研究

Kobayashi, Jun 24 September 2014 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第18599号 / 農博第2086号 / 新制||農||1027(附属図書館) / 学位論文||H26||N4874(農学部図書室) / 31499 / 京都大学大学院農学研究科応用生命科学専攻 / (主査)教授 三上 文三, 教授 植田 充美, 教授 栗原 達夫 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM
134

Design Guidelines for Organic Electrode Materials in Advanced Energy Storage Systems

Tuttle, Madison R. 12 September 2022 (has links)
No description available.
135

Tuning the metal/acid functionalities in HZSM-5 for efficient dehydroaromatization

Chen, Genwei 08 August 2023 (has links) (PDF)
The increasing production of natural gas liquids attracts both academia and industry to develop on-purpose techniques converting those light alkanes to value-added chemicals. Dehydroaromatization is an alternative path for light alkane conversion to produce aromatics but still lacks active and stable catalysts. This work aims at the development of efficient dehydroaromatization catalysts by tuning the metal/acid bifunctionality of the Pt/HZSM-5 catalyst. Additionally, through co-processing light alkane with ammonia during the dehydroaromatization process, this study also proposes a new reaction system that could directly link the C-N bond for nitrile synthesis. The results suggested that the activity, selectivity, and stability of the monometallic Pt/HZSM-5 catalyst are highly dependent upon the Pt loading, the limit loading of 100 ppm is required to maintain sufficient metal functionality. To further minimize the Pt loading, the chemical properties of the Pt species were tuned by a second metal such as Zn or Cu. Consequently, the activity and stability of the catalyst are enhanced by orders of magnitude and the maximized metal functionality was achieved at Pt loading of 10 ppm. Characterizations show that Pt can be atomically dispersed as a hybrid [Pt1-Zn6] cluster in the Pt-Zn@HZSM-5 or forming single atom alloy type [Pt1-Cu4] ensembles in the Pt-Cu@HZSM-5. Specifically, the initial turnover frequencies of propane and ethane to BTX are up to 178.8 and 128.7 s-1 over the Pt-Cu@HZSM-5, up to 3-4 orders of magnitude higher than the state-of-the-art Pt-based catalyst. Furthermore, the deactivated catalyst can be continuously regenerated, demonstrating excellent stability of such a catalyst under hash oxidation conditions for coke burn-off. A new catalytic system named ammodehydrogenation (ADeH) for ethane selective conversion to acetonitrile, ethylene, and hydrogen over a bifunctional catalyst is proposed. Ethane ADeH over the Pt/HZSM-5 catalyst is active at low temperatures and atmospheric pressure for CH3CN production. The Pt/HZSM-5 shows high coke-resistibility during the ethane ADeH due to the strong interaction of NH3 with the acid sites of the catalyst. The catalyst can be further optimized by adding Co, the Pt-Co/HZSM-5 catalyst on ethane ADeH indicating that an appropriate balance between the metal and acid functionalities is critical for ethane ADeH.
136

Characterization of ImiS, the Metallo-Β-Lactamase from Aeromonas veronii bv. sobria

Crawford, Patrick Anthony 18 November 2003 (has links)
No description available.
137

KINETIC AND SPECTROSCOPIC STUDIES OF L1, THE METALLO-β-LACTAMASE FROM Stenotrophomonas maltophilia

Zhenxin, Hu 12 August 2008 (has links)
No description available.
138

FORMATION OF C-C COVALENT BOND ON THE SURFACE OF POLY (CHLOROTRIFLUOROETHYLENE) BY SUBSTITUTION

Mazi, Wafa A. 13 December 2010 (has links)
No description available.
139

Effects of Dietary Cu, Zn and Mn on Bovine Neutrophil Function

Dietz, Ashlee Marie 22 May 2015 (has links)
No description available.
140

Third Generation Point-of-Care Device for Quantification of Zinc in Blood Serum

Zerhusen, Benjamin January 2017 (has links)
No description available.

Page generated in 0.0422 seconds