196,028 research outputs found
Preparation of Highly Active 40?wt.% Pt on Multiwalled Carbon Nanotube by Improved Impregnation Method for Fuel Cell Applications
No full text40 wt.% Pt catalyst supported on multiwalled carbon nanotube (MWCNT) was successfully synthesized by using improved aqueous impregnation method. Catalysts were characterized by HR-TEM, XRD, and X-Ray photoelectron spectroscopy. Electrocatalytic performance of the catalyst materials was investigated by electrochemical half cell test measurements. According to the results of electrochemical measurements, synthesized Pt/MWCNT catalyst presented high electrochemical activity which is mostly due to high utilization of catalyst particles and good physical properties of MWCNT supporting material. It was revealed that, improved aqueous impregnation method has a satisfactory efficiency for production of Pt/MWCNT catalyst. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA,Weinheim.
Synthesis and electrocatalytic performance of high loading active PtRu multiwalled carbon nanotube catalyst for methanol oxidation
No full textMultiwalled carbon nanotube (MWCNT) supported PtRu catalyst was prepared by improved aqueous impregnation method. The catalyst nanoparticles were characterized by using high resolution transmission electron microscopy (HR-TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) measurements. According to the results of physicochemical characterization, PtRu alloy nanoparticles with low content of surface oxidation states were successfully synthesized on the outer surface of MWCNT supporting materials. Electrocatalytic activity of catalyst materials was investigated by using electrochemical half cell and CO stripping analyses. Results of electrochemical measurements indicate that the prepared PtRu/MWCNT catalyst shows an enhanced electrochemical activity toward methanol oxidation and a high electrocatalytic activity for CO oxidation. It is believed that superior performance of the PtRu/MWCNT catalyst is mostly attributed to the high degree of alloy formation and low contents of oxidized species of Pt and Ru. © 2012 Elsevier Ltd. All rights reserved.
Facile enhancement of the active catalytic sites of N-doped graphene as a high performance metal-free electrocatalyst for oxygen reduction reaction
No full textA simple and facile N-doping process has been developed to prepare graphene nanosheets with a high loading of active catalytic sites through the combination of hydrothermal and microwave processes. High resolution transmission electron microscopy, X-ray photoelectron spectroscopy and Raman analysis have been used to characterize the morphology and composition of the prepared materials. Also, linear sweep voltammetry (LSV) was conducted to investigate the electrocatalytic performance of the N-doped specimens toward oxygen reduction reaction (ORR). It was revealed that post-treatment of hydrothermally-treated N-doped graphenes under microwave irradiation in the presence of nitrogen precursor can result in the formation of a large content of quaternary nitrogen functionalities. Also, the LSV analysis revealed that fabrication of the graphene nanosheets under the proposed N-doping strategy resulted in potent electrocatalytic activity of graphene nanosheets toward ORR through a four electron pathway. © 20181
Tungsten carbide on directly grown multiwalled carbon nanotube as a co-catalyst for methanol oxidation
No full textMultiwalled carbon nanotubes (MWCNT) were grown directly on the surface of graphite rod by using CVD process and then modified with tungsten carbide by carbothermal hydrogen carbonization technique. Then, platinum nanoparticles were deposited on the MWCNTs by means of electrodeposition technique. Catalyst materials were characterized by electron microscopy, X-ray photoelectron spectroscopy and three electrode electrochemical measurements. Catalysts supported on the directly grown MWCNTs exhibit notably better electrocatalytic performance towards methanol oxidation compared to the commercial Pt/C catalyst. Modification of MWCNTs with tungsten carbide was shown to further increase the catalyst performance. It is believed that the superior performance of catalysts prepared on the MWCNTs as catalyst support results mostly from the superior electrical contact and unique spatial configuration of the directly grown MWCNTs, while the positive effect of the tungsten carbide co-catalyst is mostly attributed to its improved resistance towards poisoning with the reaction intermediates produced during the methanol oxidation. © 2012 Elsevier B.V.
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
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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