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Shaping metal nanocrystals through epitaxial seeded growth

Description: Morphological control of nanocrystals has becomeincreasingly important, as many of their physical and chemical propertiesare highly shape-dependent. Nanocrystal shape control for both single andmultiple material systems, however, remains fairly empirical andchallenging. New methods need to be explored for the rational syntheticdesign of heterostructures with controlled morphology. Overgrowth of adifferent material on well-faceted seeds, for example, allows for the useof the defined seed morphology to control nucleation and growth of thesecondary structure. Here, we have used highly faceted cubic Pt seeds todirect the epitaxial overgrowth of a secondary metal. We demonstrate thisconcept with lattice matched Pd to produce conformal shape-controlledcore-shell particles, and then extend it to lattice mismatched Au to giveanisotropic growth. Seeding with faceted nanocrystals may havesignificant potential towards the development of shape-controlledheterostructures with defined interfaces.
Date: February 17, 2008
Creator: Habas, Susan E.; Lee, Hyunjoo; Radmilovic, Velimir; Somorjai,Gabor A. & Yang, Peidong
Partner: UNT Libraries Government Documents Department

Flat Sheet Metal Girders With Very Thin Metal Web. Part 3: Sheet Metal Girders With Spars Resistant to Bending - the Stress in Uprights - Diagonal Tension Fields

Description: This report continues the work presented in NACA-TM 605 and expands the scope to include the change in specific number of wrinkles from direction x to z, so that b and f become variable in direction z. Moreover, it seems likely that b and f increase from the edge toward the center if the sheet is infinitely thin.
Date: February 1931
Creator: Wagner, Herbert
Partner: UNT Libraries Government Documents Department

Form with Clamps

Description: The sculptural piece consists of a large seed pod shape that appears to burst from the shell but is held closed with five metal ties terminating in flower bud shapes.
Date: 1999
Creator: Lopez, Ana Maria
Partner: UNT College of Visual Arts + Design

To determine the use which should be made of art metal work in the junior high school, as indicated by the seventh grade of the demonstration school, 1935-36, and by an analysis of the field

Description: This study attempts to determine what use should be made of art metal work in the junior high school. It attempts to determine whether art metal work should be offered strictly as art metal, as combinations of art metal and wrought iron, or as combinations of art metal and wood, from the standpoint both of the child and of the ultimate aim of Industrial Arts.
Date: August 1936
Creator: Lamb, Jack Julius
Partner: UNT Libraries

Kinetic Studies and Vibrational Spectra of Disubstituted Metal Carbonyls

Description: The oxidative elimination reactions of (5-X-phen)Mo(C0)₄ (X = H, CH₃, Cl, NO₂; phen = o-phenanthroline) and (3,4,7,8-(CH₃)₄-phen)Mo(CO)₄ with mercuric chloride in acetone have been investigated. In these reactions, a carbon monoxide group is replaced by two univalent ligands, accompanied by the corresponding increase in coordination number and formal oxidation state of the central metal atom, to give products of the type, (X-phen)Mo(CO)₃(Cl)HgCl. With the exception of (3,4,7,8-(CH₃)₄-phen), the substituted o-phenanthrolines were selected so as to minimize steric differences from one substrate to another while obtaining the widest range of pKₐ of the ligand.
Date: May 1972
Creator: Jernigan, Robert Thorne
Partner: UNT Libraries

Metal Effect on the Supramolecular Structure, Photophysics, and Acid-Base Character of Trinuclear Pyrazolato Coinage Metal Complexes

Description: This article discusses the metal effect on the supramolecular structure, photophysics, and acid-base character of trinuclear pyrazolato coinage metal complexes.
Date: September 10, 2005
Creator: Omary, Mohammad A.; Rawashdeh-Omary, Manal A.; Gonser, M. W. Alexander; Elbjeirami, Oussama; Grimes, Thomas V.; Cundari, Thomas R., 1964- et al.
Partner: UNT College of Arts and Sciences

Mechanical Shoveling in Underground Metal Mines

Description: From Scope of Bulletin: "The object of the current bulletin is to present recent data on mechanical shoveling in underground metal mines and in selected nonmetal mines. This bulletin supplements the 1924 edition, but the main discussion covers mechanical shoveling only, because most of the new material relates to equipment recently developed, to improved technique in loading, and ti changes in loading practice in certain mining districts."
Date: 1940
Creator: Mosier, McHenry & Steinmesch, J. H.
Partner: UNT Libraries Government Documents Department

A Primer on Explosives for Metal Miners and Quarrymen

Description: From introduction: "This bulletin aims to give the metal miner and the quarryman information similar to that given the coal miner in Bulletin 17. Inflammable gas or dust is seldom, if ever, found in quarries or metal mines, and the danger from using explosives there is less than in coal mines; but, as the figures show, the number of men killed and injured yearly in accidents caused by explosives proves the need of both miners and mine officials striving to see that none but proper explosives are used and these are used properly."
Date: 1915
Creator: Munroe, Charles E. & Hall, Clarence
Partner: UNT Libraries Government Documents Department

Reduction of Coal by Lithium-Ethylenediamine and Reaction of Model Compounds with Metal-Amine Systems

Description: From Introduction: "This report describes Bureau investigations on the effects and significance of treating coal and model compounds by lithium-ethylenediamine and some other metal-amine systems."
Date: unknown
Creator: Reggel, Leslie; Zahn, Charles; Wender, Irving & Raymond, Raphael
Partner: UNT Libraries Government Documents Department

Shaft-Sinking Practices and Costs

Description: From Introduction: "This paper describing the methods of sinking shafts is one of a series of mining practices and costs being prepared by the United States Bureau of Mines. The best methods of performing all phases of shaft sinking are discussed herein, with particular to the practices at metal mines."
Date: 1932
Creator: Gardner, E. D. & Johnson, Fred J.
Partner: UNT Libraries Government Documents Department

Underground Ventilation at Butte

Description: From Introduction: "The officials of the North Butte mine we engage in making a study of ventilation problems before the coming of the investigators, so that opportunity was given to work with those officials for several months. This bulletin is a result of studies made from the data collected during the two and one-half years of study and observation above outlined."
Date: 1923
Creator: Harrington, Daniel
Partner: UNT Libraries Government Documents Department