117,305 research outputs found
Numerical simulation of the European 170GHz Gyrotron’s Magnetron Injection Gun in support of reduced order models development for control purposes
No full textGoing Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Ultrasound discloses entheseal involvement in inactive and low active inflammatory bowel disease without clinical signs and symptoms of spondyloarthropathy
No full textSquare Dancing with the Stars to Enhance Dynamic Hirschman Linkages?
No full textIn this Presidential Address, the author takes the reader on a reconnaissance of his life and time as a regional scientist. He points out scenery he found scintillating along the way, hoping that some may pick up the banner and chew on a few of the ideas for a while. He suggests a revisit to Albert O. Hirschman’s notion of key sectors and more empirical analysis related to Marcus Berliant’s and Masahisa Fujita’s notion of knowledge creation and transfer.Presidential Address, San Antonio, Texas, March 29, 2014 (53rd Meetings of the Southern Regional Science Association
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Application of a CFD Methodology for the Design of PEM Fuel Cell at the Channel Scale
No full textPolymer electrolyte membrane (PEM) fuel cells will play a crucial role in the decarbonization of the transport sector, in particular for heavy duty applications. However, performance and durability of PEMFC stacks is still a concern especially when operated under high power density conditions, as required in order to improve the compactness and to reduce the cost of the system. In this context, the optimization of the geometry of hydrogen and air distributors represents a key factor to improve the distribution of the reactants on the active surface, in order to guarantee a proper water management and avoiding membrane dehydration. To this purpose, the adoption of CFD simulation tools can provide a useful insight into the physical phenomena which determine the efficient operation of the fuel cell (e.g. transport of mass, heat, species, electrons and ions, electrochemical reactions, water formation and removal), providing a valuable support for the design and the optimization of the device at the channel scale. In this work, an open-source simulation library, based on the OpenFOAM code, is applied to the detailed simulation of a basic module of a PEM fuel cell arranged with simple parallel channels. The simulation methodology is based on a multi-region and multi-physics approach, where the different components of the fuel cell (namely air and fuel channels, gas diffusion layers, catalyst layers, bipolar plates) are modeled resorting to different computational grids defining different local domains, on which the specific governing equations are solved. Transport phenomena in all of the local domains are coupled and solved simultaneously. The model is firstly validated resorting to experimental data acquired on a specific test bench installed at Politecnico di Milano. Then, a detailed analysis of the flow field is conducted in order to provide guidelines for the optimization of the distributor geometry. Finally, the influence of the channel design on the fuel cell performances is investigated, highlighting the influence of the rib-to-channel width geometrical parameter on the reactants diffusion and water removal
Letter from unknown writer to Jesse L. Boyce
No full textLetter to Jesse L. Boyce from unknown author (possibly Jack) about the investigation into the powder magazine located in the Grand Canyon. Some personal news is included in the letter such as the writer's marriage to the daughter of C.A. Taylor, former Supervisor of Cochise County
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
Engineering design of a permeator against vacuum mock-up with niobium membrane
No full textPermeator Against Vacuum (PAV) is one of the technologies proposed for the Tritium Extraction and Removal System (TERS) of the Water-Cooled Lithium Lead Breeding Blanket (WCLL BB). The paper presents the activity aimed at the engineering design of a PAV mock-up with a niobium membrane, in order to later assemble and qualify it. Experience gained in the engineering design of the mock-up, the heating system, the instrumentation, and the vacuum line is illustrated. This experience will be useful for the preliminary design, the manufacturing and the operation of the PAV with niobium membrane for DEMO. Niobium was selected as membrane material of this mock-up because of its high permeability and for its lower cost compared to vanadium, the other candidate material for membranes. Besides, niobium has a lower tendency to oxidation than vanadium. Oxidation would reduce the hydrogen isotopes permeation flux. In this paper, the solution adopted to manufacture the PAV mock-up, a complex component with niobium and P22 parts, is illustrated. The Nb/P22 welding issues are also presented, in particular related to the compatibility of the welded joints with LiPb. In the chosen design, the LiPb flows with two passages in 16 (8 + 8) niobium “U” shaped pipes installed in a vacuum chamber and welded to a P22 plate. The U-pipes configuration was selected to minimize the welding area, the volume of the component and the membrane thickness while trying to preserve the highest possible extraction efficiency
Sarah L. Blum Author Visit - Warrior Nurse: PTSD and Healing
No full textHear Sarah L. Blum, author of Women Under Fire: Abuse in the Military, discuss her newest book, Warrior Nurse: PTSD and Healing followed by a Q&A and book signing.
Sarah L. Blum is a decorated Vietnam veteran who served as an operating room nurse during the intense fighting of 1967. In recognition of her service, she was awarded the Army Commendation Medal.
Sponsored by CWU Veterans Center and CWU Libraries.https://digitalcommons.cwu.edu/libraryevents/1252/thumbnail.jp
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