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Some Natural Variations in the Relative Abundance of Copper Isotopes

Description: Abstract: "The relative isotopic abundance of copper has been measured in a number of minerals. Suites of samples from Michigan and the Colorado Plateau have been examined to determine if local variations due to isotopic exchange or diffusion could be found. The relative isotopic abundance of copper in specimens from a number of other places was also determined. The variations noted were small but in most cases were felt to be significant because they were larger than the experimental error (0.1 percent in the ratio). A total spread of +3 to -8 parts per mil compared to the standard was found in the specimens tested."
Date: August 1957
Creator: Walker, Edward C.; Cuttitta, Frank & Senftle, Frank E.
Partner: UNT Libraries Government Documents Department

Copper: A Materials Survey

Description: Report issued by the U.S. Bureau of Mines discussing surveys conducted on copper. Physicality, mineral properties, history, geology, production methods, and uses of copper are presented. This report includes maps, tables, illustrations, and photographs.
Date: 1965
Creator: McMahon, A. D.
Partner: UNT Libraries Government Documents Department

Low Temperature Mechanical Properties Of Copper and Selected Copper Alloys: A Compilation From the Literature

Description: From Abstract: "In the past 60 years considerable data have been accumulated concerning the mechanical properties of copper and its alloys.It was felt that there was great need to adequately document these results in one publication. Therefore a unique type of compilation is presented. The compilation is divided into four parts. The first section is intended for quick reference use for those who are interested in average values. The second section includes data from most of the investigators who have published results on the mechanical properties of copper and its alloys. The third section is composed of tables classifying the investigations which were not in section two. The fourth section section lists, in alphabetical order, all references used."
Date: December 1, 1967
Creator: Reed, Richard P. & Mikesell, Ritchie P.
Partner: UNT Libraries Government Documents Department

Methods for Producing Secondary Copper

Description: Report issued by the U.S. Bureau of Mines discussing production of secondary copper. As stated in the introduction, "the purpose of this report is to present a complete collection of information on secondary copper in a single publication" (p. 1-2). This report includes tables, illustrations, and photographs.
Date: 1961
Creator: Spendlove, Max J.
Partner: UNT Libraries Government Documents Department

Copper Leaching Practices in the Western United States

Description: Report issued by the U.S. Bureau of Mines discussing copper leaching in the Western United States. As stated in the introduction, "the purpose of this report is to describe and discuss the different leaching and recovery methods currently employed in the production of copper from low-grade ores in the Western states" (p. 1). This report includes tables, illustrations, and photographs.
Date: 1968
Creator: Sheffer, Herman W. & Evans, LaMar G.
Partner: UNT Libraries Government Documents Department

Leaching Nonsulphide Copper Ores with Sulphur Dioxide

Description: Report issued by the Bureau of Mines discussing the sulfurous acid leaching of the Southwest experiment station. Operations and analyses of the experiment station are presented. This report includes tables, illustrations, and photographs.
Date: May 1923
Creator: Van Barneveld, Charles E. & Leaver, Edmund S.
Partner: UNT Libraries Government Documents Department

Surface and Interfacial Studies of Metal-Organic Chemical Vapor Deposition of Copper

Description: The nucleation and successful growth of copper (Cu) thin films on diffusion barrier/adhesion promoter substrates during metal-organic chemical vapor deposition (MOCVD) are strongly dependent on the initial Cu precursor-substrate chemistry and surface conditions such as organic contamination and oxidation. This research focuses on the interactions of bis(1,1,1,5,5,5-hexafluoroacetylacetonato)copper(II), [Cu(hfac)2], with polycrystalline tantalum (Ta) and polycrystalline as well as epitaxial titanium nitride (TiN) substrates during Cu MOCVD, under ultra-high vacuum (UHV) conditions and low substrate temperatures (T < 500 K). The results obtained from X-ray photoelectron spectroscopy (XPS), Auger Electron Spectroscopy (AES) and Temperature Programmed Desorption (TPD) measurements indicate substantial differences in the chemical reaction pathways of metallic Cu formation from Cu(hfac)2 on TiN versus Ta surfaces.
Date: December 1997
Creator: Nuesca, Guillermo M.
Partner: UNT Libraries

The Revival of Electrochemistry: Electrochemical Deposition of Metals in Semiconductor Related Research

Description: Adherent Cu films were electrodeposited onto polycrystalline W foils from purged solutions of 0.05 M CuSO4 in H2SO4 supporting electrolyte and 0.025 M CuCO3∙Cu(OH)2 in 0.32 M H3BO3 and corresponding HBF4 supporting electrolyte, both at pH = 1. Films were deposited under constant potential conditions at voltages between -0.6 V and -0.2 V versus Ag/AgCl. All films produced by pulses of 10 s duration were visible to the eye, copper colored, and survived a crude test called "the Scotch tape test", which involves sticking the scotch tape on the sample, then peeling off the tape and observing if the copper film peels off or not. Characterization by scanning electron microscopy (SEM)/energy dispersive X-ray (EDX) and X-ray photon spectroscopy (XPS) confirmed the presence of metallic Cu, with apparent dendritic growth. No sulfur impurity was observable by XPS or EDX. Kinetics measurements indicated that the Cu nucleation process in the sulfuric bath is slower than in the borate bath. In both baths, nucleation kinetics does not correspond to either instantaneous or progressive nucleation. Films deposited from 0.05 M CuSO4/H2SO4 solution at pH > 1 at -0.2 V exhibited poor adhesion and decreased Cu reduction current. In both borate and sulfate baths, small Cu nuclei are observable by SEM upon deposition at higher negative overpotentials, while only large nuclei (~ 1 micron or larger) are observed upon deposition at less negative potentials. Osmium metal has been successfully electrodeposited directly onto p-Si (100) from both Os3+ and Os4+ in both sulfuric and perchloric baths. This electrochemical deposition of osmium metal can provide sufficient amount of osmium which overcome ion beam implantation limitations. The deposited metal can undergo further processing to form osmium silicides, such as Os2Si3, which can be used as optical active materials. The higher osmium concentration results in large deposition currents and ...
Access: This item is restricted to the UNT Community Members at a UNT Libraries Location.
Date: August 2005
Creator: Wang, Chen
Partner: UNT Libraries

Cu Electrodeposition on Ru with a Chemisorbed Iodine Surface Layer.

Description: An iodine surface layer has been prepared on Ru(poly) and Ru(0001) electrodes by exposure to iodine vapor in UHV and polarizing in a 0.1 M HClO4/0.005 M KI solution, respectively. A saturation coverage of I on a Ru(poly) electrode passivates the Ru surface against significant hydroxide, chemisorbed oxygen or oxide formation during exposure to water vapor over an electrochemical cell in a UHV-electrochemistry transfer system. Immersion of I-Ru(poly) results in greater hydroxide and chemisorbed oxygen formation than water vapor exposure, but an inhibition of surface oxide formation relative that of the unmodified Ru(poly) surface is still observed. Studies with combined electrochemical and XPS techniques show that the iodine surface adlayer remained on top of the surface after cycles of overpotential electrodeposition/dissolution of copper on both Ru(poly) and Ru(0001) electrodes. These results indicate the potential bifunctionality of iodine layer to both passivate the Ru surface in the microelectronic processing and to act as a surfactant for copper electrodeposition. The electrodeposition of Cu on Ru(0001) or polycrystalline Ru was studied using XPS with combined ultrahigh vacuum/electrochemistry methodology (UHV-EC) in 0.1 M HClO4 with Cu(ClO4)2 concentrations ranging from 0.005 M to 0.0005 M, and on polycrystalline Ru in a 0.05M H2SO4/0.005 M CuSO4/0.001 M NaCl solution. The electrochemical data show well-defined cyclic voltammograms (CV) with a Cu underpotential deposition (UPD) peak and overpotential deposition (OPD) peak. XPS spectra of Ru electrodes emersed from perchloric acid solution at cathodic potentials indicate that ClO4- anions dissociate to yield specifically adsorbed Cl and ClOx species. Subsequent Cu deposition results in the formation of a thin, insoluble Cu(II) film with Cu(I) underneath. In contrast, similar deposition on polycrystalline Ru in the sulfuric acid/Cu sulfate solution with NaCl added yields only Cu(0), indicating that the formation of Cu(II) and Cu(I) involves both Cl and perchlorate interactions with the ...
Access: This item is restricted to the UNT Community Members at a UNT Libraries Location.
Date: August 2005
Creator: Lei, Jipu
Partner: UNT Libraries

Factors Governing the Entry of Solutions into Ores During Leaching

Description: Technical paper issued by the Bureau of Mines over studies on the leaching of copper-bearing ores. As stated in the introduction, the "penetration of the leaching medium into the body of the ore particles" (p. 1) is discussed. This paper includes tables, photographs, and illustrations.
Date: 1929
Creator: Sullivan, John D.; Keck, Walter E. & Oldright, George L.
Partner: UNT Libraries Government Documents Department

The Ferric Sulphate-Sulphuric Acid Process: With a Chapter on Producing Small Bubbles of Gas in Liquids by Submerged Orifices

Description: Report issued by the Bureau of Mines over studies conducted on the ferric sulphate-sulphuric acid process. As stated in the introduction, "the work reported here comprises merely a study of the chemistry of the process and the mechanical conditions that would have to be observed in practice" (p. 1). This report includes tables, and illustrations.
Date: 1927
Creator: Ralston, Oliver C. & Maier, Chas. G.
Partner: UNT Libraries Government Documents Department

Copper Mining in North America

Description: From introduction: "In this paper are assembled and summarized many subjects relating to the copper industry in North America. Production of mines and districts, history of the industry in North America. Production of mines and districts, history of the industry, geology, of the principal deposits, and mining methods and costs are discussed."
Date: 1938
Creator: Gardner, E. D.; Johnson, C. H. & Butler, B. S.
Partner: UNT Libraries Government Documents Department

The Smelting of Copper Ores in the Electric Furnace

Description: From Introduction: "The bulletin presents, first, a critical discussion of the possibility of smelting copper ores in the electric furnace; second, the results of the experimental work of other investigators on the electric smelting of copper; third, the results of experiments by the authors on the electric smelting of native copper concentrates and sulphide copper ores; and, fourth, a comparison of the electric furnace with the blast furnace and reverberatory furnace for copper smelting."
Date: 1915
Creator: Lyon, Dorsey A. & Keeney, Robert M.
Partner: UNT Libraries Government Documents Department

Rock Bursts in the Lake Superior Copper Mines, Keweenaw Point, Michigan

Description: From Introduction: "The effect of rock pressure may be general and continuous disintegration and reduction in size of pillars of ore and rock left for the support of the workings, resulting in the collapse of hanging wall and the closing of stopes, drifts, and shafts, or the action may be sudden and violent and aside from seriously affecting the workings may present a real hazard to the operation of mines. The object in the preparation of this report is to add to the accumulated information and from the facts presented to make suggestions for protective measures to be taken when possible."
Date: 1929
Creator: Crane, W. R.
Partner: UNT Libraries Government Documents Department

Enigmatic Realms

Description: The use of copper in my work has opened up an entirely new conceptual and esthetic world. I have expanded my vocabulary of visual imagery based on the nature of how copper reacts with fire. The organic beauty harmonizes so gracefully with the manufactured material. This new material has certainly opened up a refreshing platform on which to further develop my ideas.
Date: December 2003
Creator: Malik, Irum
Partner: UNT Libraries

Synthesis and Characterization of Copper(II) Complexes

Description: A series of dihydroxy bridged copper(II) complexes of the type [(L)Cu(OH)₂Cu(L)]x₂ * nH₂0, where L is 2,2'-bipyridine, 4,4'-dimethyl-2,2'-bipyridine or 1,10-phenanthroline, x is a counter ion, and n is the number of water molecules, was synthesized. In the case of monohydroxy bridged copper(II) complexes, we have found a new method of synthesis for [ (L)₂Cu(OH)Cu(L)₂ ] (ClO₄)₃, where L is 2,2'-bipyridine or 1,10-phenanthroline. We have synthesized five new monohydroxy bridged copper(II) complexes, thus increasing the number of monohydroxy bridged copper(II) complexes to nine. All complexes have been characterized by infrared spectroscopy, UV-visible spectroscopy, magnetic moments, and elemental analysis. The electron spin resonance results establish that the fulvic acids contain organic free radicals as an internal part of their molecular structure. The concentration of unpaired electrons will increase by increasing the pH. The unpaired electron in fulvic acid interacts with the unpaired electron on copper(II) through the Π system, and this will decrease the spin concentration of fulvic acid complexed with copper(II). The displacement of titration curve from a free ligand (fructose-1,6-diphosphate, ribulose-1,5-diphosphate, phospherine, phosphothreonine, and 3-phosphoglyceric acid, to a ligand plus copper(II) (1:1 ratio) shows there is a strong interaction between copper(II) and the corresponding ligand. All complexes absorb UV-visible at 250-300 nm. The absorption intensity changes as a function of pH. Copper (II) forms a complex with fructose-1,6-diphosphate, ribulose-1,5-diphosphate, phosphoserine, phosphothreonine, and 3-phosphoglyceric acid by the ratio of 1:3, 1:3, 1:1, 1:1, and 1:2, respectively.
Date: December 1984
Creator: Amani, Saeid
Partner: UNT Libraries

The Effect of Temperature on the Distribution of Nitric Acid Between Dibutyl Carbitol and Aqueous Solutions of Copper Nitrate

Description: This report follows a test made to determine the effect of temperature on the distribution of nitric acid between "carbitol" and gunk, extracting a number of samples of aqueous copper nitrate with samples of "carbitol" of various acidities. The data obtained is covered in Table 1.
Date: January 17, 1946
Creator: Shacklett, C. D. & Wilcox, W. J.
Partner: UNT Libraries Government Documents Department

Production Potential of Copper Deposits Associated with Permian Red Bed Formations in Texas, Oklahoma, and Kansas

Description: Report issued by the Bureau of Mines on the copper deposits in the Permian red beds from north-central Texas through Oklahoma, and into southwestern Kansas. Geologic and economic properties of the copper ore are documented. This report includes tables, maps, illustrations, and photographs.
Date: August 1970
Creator: Stroud, R. B.; McMahan, A. B.; Stroup, R. K. & Hibpshman, M. H.
Partner: UNT Libraries Government Documents Department