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Fusibility of Ash from Coals of the United States

Description: From Introduction: "Information concerning the fusibility of coal ash has become of considerable value to the consumer of coals, mainly in connection with the troublesome formation of clinker from the melting of the ash constituents of the burning coal. It is hoped that this information when used together with the large number of coal analyses published by the bureau will assist the consumer of coal in comparing different coals, and in selecting the coal best adapted for his purpose."
Date: 1922
Creator: Selvig, W. A. & Fieldner, A. C.
Partner: UNT Libraries Government Documents Department


Description: A study was made of fiber-texture type of preferred orientation in extruded Al rods and brass sheeting. Experiments to purify Zr by the zone- melting techniques were studied. Several transformation products of the decomposition of the BETA eutectoid of the Ag--Zr system were identified. The tempering of the martensitic structure of a hypoeutectoid Ag-- Zr was studied. Metallurgical treatments for the recovery of U from spent stainless steel fuel elements were investigated. Physical properties and radiation stability of the Si-- SiC fuel element material were investigated. The development and fabrication of a uniform fuel-bearing sandwich plate were continued. Methods of welding stainless steel were studied. An evaluation study was made of brazing alloys on the basis of corrosion resistance, neutron economy, flow temperature, availability, and cost. (C.H.)
Date: August 31, 1955
Creator: Bridges, W.H. ed.
Partner: UNT Libraries Government Documents Department

Large melting point hysteresis of Ge nanocrystals embedded inSiO2

Description: The melting behavior of Ge nanocrystals embedded within SiO{sub 2} is evaluated using in situ transmission electron microscopy. The observed melting point hysteresis is large ({+-} 17%) and nearly symmetric about the bulk melting point. This hysteresis is modeled successfully using classical nucleation theory without the need to invoke epitaxy.
Date: May 4, 2006
Creator: Xu, Q.; Sharp, I.D.; Yuan, C.W.; Yi, D.O.; Liao, C.Y.; Glaeser,A.M. et al.
Partner: UNT Libraries Government Documents Department

Compilation of the Melting Points of the Metal Oxides

Description: Report compiling the melting points of 70 metal oxides published prior to January 1963. Both the original melting point and the equivalent value based on the International Practical Temperature Scale of 1948 are presented. Included in the survey is information on pertinent experimental details such as the method of temperature measurement, purity, furnace type, and environmental conditions.
Date: October 10, 1963
Creator: Schneider, Samuel J.
Partner: UNT Libraries Government Documents Department

Damage Resistant Optical Glasses for High Power Lasers: A Continuing Glass Science and Technology Challenge

Description: A major challenge in the development of optical glasses for high-power lasers is reducing or eliminating laser-induced damage to the interior (bulk) and the polished surface of the glass. Bulk laser damage in glass generally originates from inclusions. With the development of novel glass melting and forming processes it is now possible to make both fused silica and a suit of meta-phosphate laser glasses in large sizes ({approx}>0.5-lm diameter), free of inclusions and with high optical homogeneity ({approx} 10{sup -6}). Considerable attention also has been focused on improving the laser damage resistance to polished optical glass surfaces. Studies have shown that laser-induced damage to surfaces grows exponentially with the number of shots when illuminated with nano-second pulses at 351-nm above a given fluence threshold. A new approach for reducing and eliminating laser-induced surface damage relies on a series of post-polishing treatment steps. This damage improvement method is briefly reviewed.
Date: August 28, 2002
Creator: Campbell, J H
Partner: UNT Libraries Government Documents Department

The Electroslag Melting Process

Description: "This Bulletin traces the development of the electroslag melting process from its modest beginnings to the present. Important basic mechanisms such as electrochemistry, thermochemistry, and heat transport are described. Since the choice of flux is a unique parameter in the electroslag process, two chapters are developed to this subject. Electroslag melting experience for reactive metals, base metals, ferrous alloys, superalloys, and the refractory metals, both inside and outside the Bureau of Mines, is outlined" (p. xi).
Date: 1976
Creator: Nafziger, R. H.
Partner: UNT Libraries Government Documents Department

Electric Brass Furnace Practice

Description: Report issued by the Bureau of Mines discussing the use of electric furnaces for melting brass, and other nonferrous alloys. Monetary benefits, health benefits, and other advantages of using electric furnaces are presented. Descriptions of furnaces and their operational methods are also presented. This report includes tables, illustrations, and photographs.
Date: 1922
Creator: Gillett, H. W. & Mack, E. L.
Partner: UNT Libraries Government Documents Department


Description: Techniques and equipment were developed for photographing of samples during in-pile meltdown experiments in TREAT. The design and materials for the transparent meltdowm facility are described. The procedures for assemblys insertion in TREAT, removal, and disassembly are outlined. (M.C.G.)
Date: January 1, 1962
Creator: Golden, G.H.; Dickerman, C.E. & Robinson, L.E.
Partner: UNT Libraries Government Documents Department

Characterization, Properties and Applications of Novel Nanostructured Hydrogels.

Description: The characterization, properties and applications of the novel nanostructured microgel (nanoparticle network and microgel crystal) composed of poly-N-isopropylacrylanmide-co-allylamine (PNIPAM-co-allylamine) and PNIPAM-co-acrylic acid(AA) have been investigated. For the novel nanostructured hydrogels with the two levels of structure: the primary network inside each individual particle and the secondary network of the crosslinked nanoparticles, the new shear modulus, drug release law from hydrogel with heterogeneous structure have been studied. The successful method for calculating the volume fraction related the phase transition of colloid have been obtained. The kinetics of crystallization in an aqueous dispersion of PNIPAM particles has been explored using UV-visible transmission spectroscopy. This dissertation also includes the initial research on the melting behavior of colloidal crystals composed of PNIPAM microgels. Many new findings in this study area have never been reported before. The theoretical model for the columnar crystal growth from the top to bottom of PNIPAM microgel has been built, which explains the growth mechanism of the novel columnar hydrogel colloidal crystals. Since the unique structure of the novel nanostructured hydrogels, their properties are different with the conventional hydrogels and the hard-sphere-like system. The studies and results in this dissertation have the important significant for theoretical study and valuable application of these novel nanostructured hydrogels.
Access: This item is restricted to the UNT Community Members at a UNT Libraries Location.
Date: December 2006
Creator: Tang, Shijun
Partner: UNT Libraries

Cold-Mold Arc Melting and Casting

Description: Report issued by the Bureau of Mines discussing the cold-mold arc-melting technology and techniques. As stated in the introduction, "the objectives of this book are twofold: To accumulate and update Bureau of Mines contributions to cold-mold arc melting and casting, and, by addition of pertinent chapters, to provide production melters and researchers with the best possible view of the overall technique" (p. 1). This report includes tables, illustrations, and photographs.
Date: 1968
Creator: Beall, Robert A.; Caputo, F.; Hayes, E. T.; Asai, G.; Roberson, A. H.; Clites, P. G. et al.
Partner: UNT Libraries Government Documents Department

Absolute beam flux measurement at NDCX-I using gold-melting calorimetry technique

Description: We report on an alternative way to measure the absolute beam flux at the NDCX-I, LBNL linear accelerator. Up to date, the beam flux is determined from the analysis of the beam-induced optical emission from a ceramic scintilator (Al-Si). The new approach is based on calorimetric technique, where energy flux is deduced from the melting dynamics of a gold foil. We estimate an average 260 kW/cm2 beam flux over 5 {micro}s, which is consistent with values provided by the other methods. Described technique can be applied to various ion species and energies.
Date: April 1, 2011
Creator: Ni, P. A.; Bieniosek, F. M.; Lidia, S. M. & Welch, J.
Partner: UNT Libraries Government Documents Department

Simple model of laser damage initiation and conditioning in frequency conversion crystals

Description: Laser conditioning, i.e. pre-exposure to less than damaging laser fluence, has been shown to improve the damage resistance of KDP/DKDP frequency conversion crystals. We have extended our damage model, small absorbing precursors with a distribution of sizes, to describe various damage related properties such as damage density and effects of laser conditioning in crystals. The model assumes the rate limiting process for both initiation and conditioning depends on temperature and that separate threshold temperatures exist for either conditioning or damage initiation to occur. This is reasonable in KDP/DKDP since the melting temperature is far below the temperatures associated with plasma formation and damage events. This model is capable of accounting for some recently observed damage-conditioning behaviors.
Date: October 28, 2005
Creator: Feit, M D; Rubenchik, A M & Trenholme, J B
Partner: UNT Libraries Government Documents Department

Effective determination of coexistence curves using reversible-scaling molecular dynamics simulations

Description: We present a simulation technique that allows the calculation of a phase coexistence curve from a single nonequilibrium molecular dynamics (MD) simulation. The approach is based on the simultaneous simulation of two coexisting phases, each in its own computational cell, and the integration of the relevant Clausius-Clapeyron equation starting from a known coexistence point. As an illustration of the effectiveness of our approach we apply the method to explore the melting curve in the Lennard-Jones phase diagram.
Date: December 18, 2000
Creator: de Koning, M; Antonelli, A & Yip, S
Partner: UNT Libraries Government Documents Department

Melting of transition metals at high pressure and the influence of liquid frustration. I. The late metals Cu, Ni and Fe

Description: This report focuses on the role that frustration, or preferred liquid local causes ordering, plays in the melting of transition metals. Specifically, Cu, Ni and Fe. It is proposed that for liquids of metals with partially filled d-bands (Ni and Fe) frustration caused by Peierls/Jahn-Teller distortion and pressure-induced s-d electron promotion provides a mechanism for creating and enhancing the stability of local structures. At the most elementary level, liquid structures are essentially impurities that lower the freezing point. In the case of transition metals with partially filled d-bands, the application of pressure induces s-d electron promotion increases the concentration of local structures. This leads to melting slopes for Ni and Fe that are considerably lower than measured for Cu, and lower than for theoretical predictions employing models in which liquid structures are neglected.
Date: March 15, 2007
Creator: Ross, M; Boehler, R & Errandonea, D
Partner: UNT Libraries Government Documents Department

Sum-frequency spectroscopic studies: I. Surface melting of ice, II. Surface alignment of polymers

Description: Surface vibrational spectroscopy via infrared-visible sum-frequency generation (SFG) has been established as a useful tool to study the structures of different kinds of surfaces and interfaces. This technique was used to study the (0001) face of hexagonal ice (Ih). SFG spectra in the O-H stretch frequency range were obtained at various sample temperatures. For the vapor(air)/ice interface, the degree of orientational order of the dangling OH bonds at the surface was measured as a function of temperature. Disordering sets in around 200 K and increases dramatically with temperature, which is strong evidence of surface melting of ice. For the other ice interfaces (silica/OTS/ice and silica/ice), a similar temperature dependence of the hydrogen bonded OH stretch peak was observed; the free OH stretch mode, however, appears to be different from that of the vapor (air)/ice interface due to interactions at the interfaces. The technique was also used to measure the orientational distributions of the polymer chains on a rubbed polyvinyl alcohol surface. Results show that the polymer chains at the surface appear to be well aligned by rubbing, and the adsorbed liquid crystal molecules are aligned, in turn, by the surface polymer chains. A strong correlation exists between the orientational distributions of the polymer chains and the liquid crystal molecules, indicating that the surface-induced bulk alignment of a liquid crystal film by rubbed polymer surfaces is via an orientational epitaxy-like mechanism. This thesis also contains studies on some related issues that are crucial to the above applications. An experiment was designed to measure SFG spectra in both reflection and transmission. The result confirms that SFG in reflection is generally dominated by the surface contribution. Another issue is the motional effect due to fast orientational motion of molecules at a surface or interface. Calculations show that the effect is significant if the ...
Date: December 21, 2000
Creator: Wei, Xing
Partner: UNT Libraries Government Documents Department

Liquid Metal Processing and Casting Experiences at the U.S. Department of Energy's Albany Research Center

Description: In this paper we will discuss some of the early pioneering work as well as some of our more recent research. The Albany Research Center (ARC) has been involved with the melting and processing of metals since it was established in 1942. In the early days, hardly anything was known about melting refractory or reactive metals and as such, virtually everything had to be developed in-house. Besides the more common induction heated air-melt furnaces, ARC has built and/or utilized a wide variety of furnaces including vacuum arc remelt ingot and casting furnaces, cold wall induction furnaces, electric arc furnaces, cupola furnaces and reverberatory furnaces. The melt size of these furnaces range from several grams to a ton or more. We have used these furnaces to formulate custom alloys for wrought applications as well as for such casting techniques as spin casting, investment casting and lost foam casting among many. Two early spin-off industrializations were Wah Chang (wrought zirconium alloys for military and commercial nuclear applications) and Oremet (both wrought and cast Ti). Both of these companies are now part of the ATI Allegheny Ludlum Corporation.
Date: September 1, 2005
Creator: Jablonski, Paul D. & Turner, Paul C.
Partner: UNT Libraries Government Documents Department