306,908 research outputs found
Locking phenomena in microwave oscillators with mismatched loads
No full textSeptember 11, 1950." "Supplement of Technical report no.63."Bibliography: p. 13.Army Signal Corps Contract No. W36-039-sc-32037 Project No. 102B. Dept. of the Army Project No. 3-99-10-022.Joseph C. Pitts, William F. Wicks [and] Edward E. David, Jr
Going 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
E.B. Wicks Real Estate Co. P.1
No full textE. B. Wicks Company, 100 South and State, showing building and employees, October 3, 1944
Design of Integrated Nanostructured Wicks for High-Performance Vapor Chambers
No full textThe performance of passive phase-change cooling devices, such as vapor chambers or heat pipes, may be significantly enhanced by exploiting the superior thermal properties of carbon nanotube (CNT) arrays. The potential for large reductions in overall package resistance with the use of high-conductivity wick materials enhanced with CNT nanostructures is investigated. While such nanostructured wicks feature very small pore sizes that support high capillary pressures, it is shown that the high fluid flow resistance through these dense arrays prevents their use as the lone fluid transport mechanism. It is proposed that evaporator surfaces comprised of nanostructured wicks fed by interspersed conventional wick materials (such as sintered powders) can provide the required permeability for fluid flow while simultaneously decreasing the effective evaporator thermal resistance. Optimization of wicks with integrated sintered and nanostructured areas requires a study of the trade-offs between the greater permeability of the sintered materials and the greater capillary pressure and thin-film evaporation area offered by the nanostructures. A numerical model is developed to estimate the thermal resistance of the evaporator region compared to that of a homogeneous sintered powder wick. The inputs needed for this model include the permeability and the capillary pressure in the two regions. A parametric study is conducted as a function of the ratio of conduction and evaporative resistances for the nanostructured and sintered regions. For a given heat input, the optimal liquid-feeding geometry that minimizes thermal resistance is obtained. In the best cases, the thermal resistance is reduced by a factor of thirteen through the use of the integrated nanostructured wicks compared to the resistance of a homogeneous sintered powder wick
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
Estudo teórico e experimental da aplicação de meios porosos cerâmicos em LHP e CPL
No full textTese (doutorado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduaçao em Engenharia Mecânica, Florianópolis, 2010O controle térmico na indústria eletrônica tem crescido em importância devido à contínua diminuição de tamanho e ao aumento na potência dos componentes. Nestas aplicações, buscam-se dispositivos eficientes de transferência de calor, capazes de transferir grandes cargas de calor com uma diferença mínima de temperatura. Neste contexto, os tubos de calor (Heat Pipes - HPs), os tubos de calor em forma de circuito (Loop Heat Pipes - LHPs) e as bombas capilares (Capillary Pumping Loops - CPLs) são alternativas confiáveis e viáveis para a dissipação de calor. Os evaporadores capilares da maioria dos LHPs e CPLs utilizam meios porosos feitos de metal ou de plástico. Neste trabalho, um meio poroso cerâmico é proposto para aplicações em LHPs e CPLs. O desempenho do meio poroso cerâmico como evaporador capilar é analisado teórica e experimentalmente. Primeiramente, é feita uma análise teórica de transferência de calor e de massa de um evaporador capilar plano com uma estrutura porosa formada por uma ou duas camadas com propriedades diferentes. O meio poroso tem formato de um disco e é instalado entre os canais de líquido e de vapor. Um fluxo de calor externo é aplicado à superfície superior da estrutura porosa onde ocorre a evaporação do fluido de trabalho. A transferência de calor e de massa é modelada usando as equações macroscópicas de conservação da energia e da massa. O fluido é assumido incompressível, prevalece o equilíbrio térmico local e a Lei de Darcy é usada para modelar o fluxo viscoso dentro do meio poroso. Os modelos desenvolvidos permitem verificar o efeito das variáveis de projeto no desempenho do evaporador capilar tais como fluidos de trabalho, dimensões, permeabilidade, raio médio de poros e condutividade térmica do meio poroso. Para as análises experimentais, testes de desempenho de dois LHPs, um utilizando acetona e o outro água como fluidos de trabalho, foram realizados para potências de até 25 W. Além disso, testes de desempenho de um CPL usando água foram realizados para potências de até 30 W. O meio poroso cerâmico utilizado possui 50% de porosidade, distribuição de raio de poro entre 1 e 3E-6 m e uma permeabilidade de 1,5 E-14 m2. Considerando uma temperatura de operação limite de 100 °C e regime permanente, os LHPs foram capazes de transferir até 15 W para água e 25 W para acetona, enquanto que o CPL foi capaz de transferir até 30 W. Apesar do bom desempenho dos sistemas de bombeamento capilar avaliados, observou-se que mais pesquisas ainda são necessárias, buscando otimizar as propriedades termofísicas do meio poroso cerâmico e melhorar o projeto dos LHPs e do CPL
Edward B. Wicks, elected May 13, 1889, died July 29, 1926
No full textPortrait of Edward Bartlett Wicks, member of the Alta Club, May 13, 1889 to July 29, 1926, owner of E. B. Wicks Company, uncle of Bartlett Wick
Flipping forests: estimating future carbon sequestration of the boreal forest using remotely sensed data
No full textTo reduce uncertainty in national and global carbon budgets, carbon sequestration can be estimated for large areas of land by driving an aspatial ecosystem simulation model (ESM) spatially, with remotely sensed biophysical data. This letter investigates the impact of future climate change on the boreal forest carbon budget by driving the FOREST-BGC (-Bio-Geochemical Cycling) ESM (under three different carbon dioxide (CO2) emission scenarios) using remotely sensed (NOAA AVHRR) estimates of leaf area index (LAI) as part of the Boreal Ecosystem Atmosphere Study (BOREAS).We demonstrate that boreal forests will continue to provide a substantial 'brake' on the rate of increase in atmospheric CO2, provided anthropogenic emissions reduce dramatically to within the limits of the 'Kyoto Protocol'. However, if anthropogenic emissions follow the unmitigated scenario (i.e. 'business as usual'), carbon sequestration will increase to a maximum by around 2050 but thereafter collapse, resulting in a disappearance of the boreal carbon sink by around 2080. An ESM and remotely sensed data was a viable predictive tool for the study of carbon sequestration over land and has potential as an aid for policy and management decisions
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