254,882 research outputs found

    Investigation of Icing Characteristics of Typical Light Airplane Engine Induction Systems

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    The icing characteristics of two typical light-airplane engine induction systems were investigated using the carburetors and manifolds of engines in the horsepower ranges from 65 to 85 and 165 to 185. The smaller system consisted of a float-type carburetor with an unheated manifold and the larger system consisted of a single-barrel pressure-type carburetor with an oil-jacketed manifold. Carburetor-air temperature and humidity limits of visible and serious Icing were determined for various engine power conditions. Several.methods of achieving ice-free induction systems are discussed along with estimates of surface heating requirements of the various induct ion-system components. A study was also made of the icing characteristics of a typical light-airplane air scoop with an exposed filter and a modified system that provided a normal ram inlet with the filter located in a position to Induce inertia separation of the free water from the charge air. The principle of operation of float-type carburetors is proved to make them inherently more susceptible to icing at the throttle plate than pressure-type carburetors.. The results indicated that proper jacketing and heating of all parts exposed to the fuel spray can satisfactorily reduce or eliminate icing in the float-type carburetor and the manifold. Pressure-type carburetors can be protected from serious Icing by proper location of the fuel-discharge nozzle combined with suitable application of heat to critical parts

    Features of coal sludge processing on CDF "Gukovskaya"

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    Наведено результати удосконалення технології зневоднення вугільних шламів нефлотаційної крупності на високочастотних грохотах типу ГВЧ шляхом застосування різнопохилих ділянок робочої поверхні, що дозволило зменшити вологість товарної вугільної продукції на 0,2%.Приведены результаты усовершенствования технологии обезвоживания угольных шламов нефлотационной крупности на высокочастотных грохотах типа ГВЧ путем применения разнонаклонных участков рабочей поверхности, что позволило уменьшить влажность товарной угольной продукции на 0,2%.Results of improvement of technology of dewatering coal slimes not float size of the high-frequency screens type SHF by applying sections of the working surface of a different angle, that allowed to reduce the humidity of saleable coal production by 0,2%

    Light-induced activation and deactivation of bulk defects in boron-doped float-zone silicon

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    In this paper, we present new insight in the degradation and subsequent recovery of charge carrier lifetime upon light soaking at 75 °C observed in float-zone silicon wafers. Variations of doping type, dielectric passivation schemes and thermal treatments after layer deposition were performed. The degradation was only observed for p-type float-zone silicon wafers passivated with passivation schemes involving silicon nitride layers. An influence of thermal treatments after deposition was found. N-type wafers did not degrade independent of their passivation scheme. Room temperature re-passivation experiments showed the degradation to affect the wafer bulk, and photoluminescence studies demonstrated fine lateral striations of effective lifetime. We conclude that the degradation is caused by bulk defects that might be related to hydrogen complexes

    Thin N-I-P radiation resistant solar cells

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    Several sets of N-I-P sola cells were fabricated from high resistivity silicon to test the effectiveness of various methods for hardening these devices against radiation. Different substrate materials were used to provide information on the effects of dopant concentration, silicon type, and the presence of oxygen. In some cells, P-type float-zone refined silicon of 800, 8000 and 15,000 omega-cm resistivity was used to provide a basis for studying resistivity and purity effects. In other cells, N-type silicon (approximately 800 omega-cm) was used to allow a comparison of dopant type. Oxygen-rich, crucible-grown, silicon (approximately 100 omega-cm, p-type) will provide information on purity effects and defect gettering. Lithium was introduced into different types of silicon to determine if mobile ions can reduce radiation induced defects in high resistivity material. Thin cells (2 mil) were fabricated to study the effects of cell thickness and carrier injection on radiation damage. The electrical characteristics of the different sets of cells were measured, analyzed, and compared prior to shipment of the cells to NASA/Lewis for irradiation

    Search for conformal invariance in compressible two-dimensional turbulence

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    We present a search for conformal invariance in vorticity isolines of two-dimensional compressible turbulence. The vorticity is measured by tracking the motion of particles that float at the surface of a turbulent tank of water. The three-dimensional turbulence in the tank has a Taylor microscale Reλ160Re_\lambda \simeq 160. The conformal invariance theory being tested here is related to the behavior of equilibrium systems near a critical point. This theory is associated with the work of L\"owner, Schramm and others and is usually referred to as Schramm-L\"owner Evolution (SLE). The system was exposed to several tests of SLE. The results of these tests suggest that zero-vorticity isolines exhibit noticeable departures from this type of conformal invariance

    Recombination lifetimes in gamma-irradiated P-type float zone silicon

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    Electron decay rate and absorption cross sections for electron holes and recombination in gamma irradiated n-type silico
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