Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 650 for “"Chromium"”.
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Investigating chromium cycling in global oxygen deficient zones with chromium isotopes
Chromium (Cr) isotopes have shown great potential as a paleo-redox proxy to trace the redox conditions of ancient oceans and atmosphere. However, its cycling in modern environments is poorly constrained. In my thesis, I attempt to fill in the gap of our understanding of chromium cycling in the …
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Feasibility study to extract iron and chromium from chromium contaminated soils
Chromium contaminated soils, besides being recognized for toxic and hazardous hexavalent chromium, contain high iron concentrations. At some sites, concentrations of iron oxide are higher than 30%. Both iron and chromium in soils have recyclable value provided they can be either concentrated in the …
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Investigating Chromium Cycling in Global Oxygen Deficient Zones with Chromium Isotopes
Chromium (Cr) isotopes have shown great potential as a paleo-redox proxy to trace the redox conditions of ancient oceans and atmosphere. However, its cycling in modern environments is poorly constrained. In my thesis, I attempt to fill in the gap of our understanding of chromium cycling in the …
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The Reactivity Studies of Chromium-Chromium Quintuple Bond Stabilized by Aminopyridinato Ligands
The reactivity of the quintuply bonded dichromium complex (1) stabilized by aminopyridinato ligands have been investigated. The reaction of 1 with alkynes and dienes leads to cycloaddition reactions. Furthermore, the reaction of 1 with O2 leads to the formation of dimeric CrV specie while, higher …
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Tempering of chromium steels
Thesis (Sc.D.) Massachusetts Institute of Technology. Dept. of Metallurgy, 1950
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Sigma phase in the ternary systems chromium-cobalt-copper and chromium-manganese-copper
… equilibrium with the terminal solid solutions of chromium, cobalt, and copper. In the Cr-Mn-Cu ternary isothermal section sigma comes into equilibrium with the terminal solid solution of chromium and cobalt and the face-centered cubic solid solution of copper in manganese. From these data the …
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1/F Noise & slow spin dynamics in chromium, chromium alloys, and disordered iron zirconium
… systems are described in this thesis. In chromium, 1 If noise was used as a probe to study spin density wave polarization dynamics. Measurements of the noise anisotropy in a high quality single crystal of Cr revealed a temperature range where polarization dynamics were the dominant source …
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Response of chromium and chromium-aluminum coatings on zircaloy-2 to high temperature steam
High temperature steam exposure leads to rapid oxidation of Zr based cladding, which will potentially lead to cladding failure. Our approach is to apply CrAl or Cr coatings on Zircaloy by magnetron sputtering to improve the oxidation resistance of cladding materials. The goal of this research is to …
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Electrochemistry of iron-chromium alloys
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1991.
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Carbothermic-vacuum reduction of chromium oxide in electrolytic chromium: a hybrid phenomenological-stochastic process simulation model
Includes bibliographical references (pages 179-180).
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The marine biogeochemistry of chromium isotopes
In the ocean, chromium (Cr) is a redox-sensitive trace metal. The reduction of Cr(VI) to Cr(III) occurs in oxygen deficient zones (ODZs), and Cr reduction in general has been identified as a significant Cr isotope fractionation mechanism. This thesis presents the first Cr isotope variations (d53Cr) …
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Speciation of chromium in environmental matrices.
… extraction, separation and determination of chromium(III) and (VI) in sewage sludge, soil and dried plant material were critically evaluated. The results obtained illustrate the difficulties of speciation analysis in such complex matrices. A method based on single extraction with 0.43 mol …
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Aspects of organometallic chromium nitrosyl chemistry
… complex with HSnPh3 yields the first isolable chromium nitrosyl hydride, CpCr(N0)(PPh3)(H)(SnPh3). The solid-state molecular structure of the hydride complex has been established by X-ray methods. The reaction of CpCr(N0)(PPh3)I with Me3SiCH2MgC1 to obtain CpCr(N0)(PPh3)CH2SiMe3 has been …
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Nuclear magnetic resonance in chromium tribromide.
Massachusetts Institute of Technology. Dept. of Physics. Thesis. 1966. Ph.D.
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The marine biogeochemistry of chromium isotopes
In the ocean, chromium (Cr) is a redox-sensitive trace metal. The reduction of Cr(VI) to Cr(III) occurs in oxygen deficient zones (ODZs), and Cr reduction in general has been identified as a significant Cr isotope fractionation mechanism. This thesis presents the first Cr isotope variations (653 …
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Study of chromium in welding fume
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1997.
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Extractable chromium, iron, and manganese from two Michigan soils as related to soil pH and applied chromium
Thesis (M.S.)--Michigan State University. Dept. of Crop and Soil Sciences,
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Plasma-assisted deposition of chromium, fluorocarbon and chromium/carbon/fluorine films on glass, polymer and metal substrates
Sputter deposition of chromium (Cr), plasma polymerization of hexafluoroethane (C$\sb2$F$\sb6$), and plasma-assisted deposition of chromium/carbon/fluorine (Cr/C/F) thin films onto glass, polytetrafluoroethylene (PTFE), and low carbon, cold rolled steel substrates has been studied. Depositions were …
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