2,541 research outputs found
Study shows effect of surface preparations on improving thermionic emission
Specimen thermionic emitters were electropolished and electroetched to study the effect of surface preparations on improving thermionic emission. The best technique found was to electropolish the annealed rhenium surface and then electroetch it. The effect of electroetching was to remove other crystal planes faster than basal planes
Thermal energy storage/converter prototype design, fabrication and testing third monthly progress report, 3 may - 2 jun. 1965
Thermal energy storage converter with rhenium capsul
Nul op de Trafo Analysis:Houtlaan, Assen
The neighborhood of Houtlaan in Assen, the Netherlands, has ambitious targets for reducing the neighborhood’s carbon emissions and increasing their production of their own, sustainable energy. Specifically, they wish to increase the percentage of houses with a heat pump, electric vehicle (EV) and solar panels (PV) to 60%, 70% and 80%, respectively, by the year 2030. However, it was unclear what the impacts of this transition would be on the electricity grid, and what limitations or problems might be encountered along the way. Therefore, a study was carried out to model the future energy load and production patterns in Houtlaan. The purpose of the model was to identify and quantify the problems which could be encountered if no steps are taken to prevent these problems. In addition, the model was used to simulate the effectiveness of various proposed solutions to reduce or eliminate the problems which were identified
Two nonlinear systems from mathematical physics
The dissertation is divided into two chapters.
In the first one, we consider the 2-Vortex problem for two point vortices in a complex domain. The Hamiltonian of the system contains the regular part of a hydrodynamic Green’s function, the Robin function h and two coefficinets which are the strengths of the point vortices. We prove the existence of infinitely many periodic solutions with minimal period T which are a superposition of a slow motion of the center of vorticity along a level line of h and of a fast rotation of the two vortices around their center of vorticity. These vortices move in a prescribed subset of the domain that has to satisfy a geometric condition. The minimal period can be any T in a certain interval. Subsets to which our results apply can be found in any generic bounded domain. The proofs are based on a recent higher dimensional version of the Poincaré-Birkhoff theorem due to Fonda and Ureña.
In the second part, we study bifurcations of a multi-component Schrödinger system. We construct a solution branch synchronized to a positive solution of a simpler system. From this branch, we find a sequence of local bifurcation values in the one dimensional case and also in the general case provided that the positive solution is nondegenerate
The Dancing display and courtship of Jackson\u27s Whydah (Coliuspasser jacksoni Sharpe)
Volume: XVII
The variation in pressures exerted by commercially available compression garments
Commercially available compression garments (CGs) demonstrate the enhanced recovery from exercise in some, but not all studies. It is possible that in some cases the degree of compression pressure (ComP) exerted is not sufficient to produce any physiological benefit. The aim of this investigation was to identify the levels of ComP exerted by commercially available CGs. This study was composed of two parts. In part A 50 healthy, physically active individuals (n=26 male, n=24 female) were fitted with CGs according to manufacturer’s guidelines. ComP was measured in participants standing in the anatomical position with a pressure measurement device inserted between the skin and the garment. Data were compared to ‘ideal’ pressure values proposed in the literature. In part B ComP in three different brands of CG were compared in a population of 29 men who all wore a medium sized garment. A one way ANOVA indicated that there was a significant difference (P0.05) between observed and ideal pressures in the calf of the male population. No significant differences in pressure (P>0.05) were observed between CG brands at the quadriceps or calf. In conclusion a large number of individuals may not be experiencing an adequate ComP from CG, and this is true for all 3 of the major brands of CGs tested in this investigation
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