196,080 research outputs found
Sol-gel deposition and characterization of Mn2+-doped silicate phosphor films
No full textMn2+ doped Zn2SiO4 and Mg2Gd8(SiO4)(6)O-2 phosphor films were deposited on silicon and quartz glass substrates by sol-gel process (dip-coating). The variations of sol viscosity with time and film thickness with the number of layers were investigated in Zn2SiO4: Mn system. The results of XRD and IR showed that the Zn2SiO4: Mn films remained amorphous below 700 degrees C and crystallized completely around 1000 degrees C. From AFM studies, it was observed that the grains with 0.5-0.8 mu m size packed closely in Zn2SiO4: Mn films, which were uniform and crack free. The luminescence properties of Zn2SiO4: Mn films were characterized by absorption, excitation and emission spectra as well as luminescence decay. These properties were discussed in derail by a comparison with those of Mn2+ (and Pb2+)-doped Mg2Gd8(SiO4)(6)O-2 phosphor films. (C) 2000 Elsevier Science S.A. All rights reserved
Nano sized Pd particles in A SiO2 matrix by sol-gel processing
No full textPd colloid containing Ormocers (ORganically MOdified CERamic) have been prepared from Pd amino complexes of the type Pd[NH2CH2CH2NH(CH2)3Si(OMe)3]2ac2 by hydrolysis and condensation (sol-gel reaction) of the silane together with SI(OEt)4 and Si(OEt)3(CH2)3OCH2CHCH2O. The amino complex formation is necessary to avoid spontaneous reduction and uncontrolled colloid formations in the liquid phase. This synthesis route leads to Pd colloid containing powders and coatings on glass. By thermal curing (temperatures up to 500°C) using different atmoshperic conditions (N2, Ar, H2/N2) brown to deep black coatings on glass with transmission values from 80 to 0% can be obtained. The average particle size can be controlled by varying the molar ratio of the used Pd salt (Pd(ac)2) and the aminosilane
Dr. Duane M. Jackson, Morehouse College, July 2011
No full textThis video is a conversation with Dr. Duane M. Jackson. Dr. Jackson talks about his paper, "Recall and the Serial Position Effect: The Role of Primacy and Recency on Accounting Students' Performance." Jackie Daniel, AUC Woodruff Library, is the interviewer
"Reflections on the subject of Emigration from Europe with a view to Settlement in the United States" By M. Carey.
No full text"Reflections on the subject of Emigration from Europe with a view to Settlement in the United States: containing bried sketches of the moral and political character of those states.
By M. Carey, member of the American philosophical, and of the American Antiquarian Society, and author of The Olive Branch, Cindiciae Hibernicae, essays on banking, on political economy, and on internal improvement.
To which are now added the English editor's comments on the subject; together with Important Advice to Emigrants, and Cautions Against Impositions Practiced in the Outports
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Dr. Glendon Swarthout
No full textHosted by Roger M. Busfield, MSU Assistant Professor of Speech and Theater, Meet the Author is designed to introduce a general audience to a contemporary author and their work through in-depth interviews. This episode features a conversation between Dr. Glendon Swarthout, prolific author and English professor at MSU, and assistant professors Sam S. Baskett and Theodore B. Strandness
Simulation of thermal plant optimization and hydraulic aspects of thermal distribution loops for large campuses
No full textFollowing an introduction, the author describes Texas A&M University and its utilities system. After that, the author presents how to construct simulation models for chilled water and heating hot water distribution systems. The simulation model was used in a $2.3 million Ross Street chilled water pipe replacement project at Texas A&M University. A second project conducted at the University of Texas at San Antonio was used as an example to demonstrate how to identify and design an optimal distribution system by using a simulation model. The author found that the minor losses of these closed loop thermal distribution systems are significantly higher than potable water distribution systems. In the second part of the report, the author presents the latest development of software called the Plant Optimization Program, which can simulate cogeneration plant operation, estimate its operation cost and provide optimized operation suggestions. The author also developed detailed simulation models for a gas turbine and heat recovery steam generator and identified significant potential savings. Finally, the author also used a steam turbine as an example to present a multi-regression method on constructing simulation models by using basic statistics and optimization algorithms. This report presents a survey of the author??s working experience at the Energy Systems Laboratory (ESL) at Texas A&M University during the period of January 2002 through March 2004. The purpose of the above work was to allow the author to become familiar with the practice of engineering. The result is that the author knows how to complete a project from start to finish and understands how both technical and nontechnical aspects of a project need to be considered in order to ensure a quality deliverable and bring a project to successful completion. This report concludes that the objectives of the internship were successfully accomplished and that the requirements for the degree of Degree of Engineering have been satisfied
Sol-Gel-Materialsysteme für 1,3 [my]m-Wellenleiterverstärker : Abschlußbericht zum BMBF-Verbundvorhaben, Laufzeit: 01.08.94 - 30.09.97
No full textDatenübertragungsnetze gewinnen durch den zunehmenden globalen Informationsaus¬tausch eine immer größere Bedeutung. Die optische Signalübertragung bietet hierfür gegenüber der elektronischen den Vorteil einer hohen Datenübertragungsrate und einer hohen Bandbreite. Die optischen Signale werden mit Kieselglasfasern bei einer Wellenlänge von 1,3 µm und 1,55 µm übertragen, da hier Absorptionsminima der Kieselglasfasern liegen. Um die auf langen Übertragungsstrecken dennoch spürbaren, durch Absorption und Streuung hervorgerufenen intrinsischen Verluste auszugleichen, werden optische Verstärker benötigt. Diese bieten gegenüber den elektrooptischen Verstärkern den Vorteil, daß die Umwandlung des optischen in ein elektrisches Signal vor der Modulierung entfällt, so daß höhere Übertragungsraten möglich werden. Optische Verstärker basieren auf der vom Signallicht stimulierten Emission von Fluoreszenzstrahlung durch Ionen, welche durch optisches Pumpen angeregt werden. Seltenerdionen sind hierfür geeignet, da bei diesen f-f¬Übergänge angeregt werden können, die zu einer Fluoreszenz im nahen Infrarotbereich (NIR) führen.[...
Intern experience at CH���M Hill, Inc.: an internship report
No full textIncludes author's vita"Submitted to the College of Engineering of Texas A&M University in partial
fulfillment of the requirement for the degree of Doctor of Engineering."Includes bibliographical referencesA review of the author's internship experience with CH���M HILL, Inc.
during the period September 1975 through May 1976 is presented. During this nine month
internship the author worked as an Engineer II in the Industrial Processes discipline of this
large consulting engineering firm... The author's prime responsibility was as one of three
lead design engineers on the design of a large wastewater treatment facility for a pulp mill
in Hoquiam, Washington owned by ITT Rayonier Inc. The work generally consisted of the design
of individual treatment units and associated piping and pumping. The purpose of the project
was to provide wastewater treatment capabilities that would satisfy the effluent limitations
(standards) imposed upon the mill by the State of Washington Department of Ecology and the
U.S. Environmental Protection Agency. The author's assignment also entailed necessary
interaction with the project manager and other CH���M HILL design engineers and support staff
members, the client's representatives, and representatives of two other consulting engineering
firms working on the project. Thus, the internship position at CH���M HILL provided considerable
experience coordinating the author's work with the work of other engineers, guiding the design
and administrative efforts of a support staff, and interacting regularly with the client and
other consulting firms. This broad exposure to a variety of engineering and organizational
problems provided a valuable educational experience
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