Chamber pressure

About: Chamber pressure is a research topic. Over the lifetime, 2988 publications have been published within this topic receiving 30725 citations.

Nonlinear Combustion Instability in a Multi-Injector Rocket Engine

Abstract: A computational study is presented of the nonlinear combustion instability of a multi-injector rocket engine. The study addresses a choked nozzle and a combustion chamber with 10 and 19 coaxial inj...

Hydraulic valve arrangement with locking function

Abstract: The invention concerns a hydraulic valve arrangement with locking function. It has a control valve (9), which in two operating positions (11, 12) connects one motor connection (A) with a pump connection and a second motor connection (B) with a tank connection and vice versa, and in a locking position (10) separates both motor connections (A, B) from pump and tank connection. Further, there are two lock valves (16, 17), each connected between the control valve (9) and one of the motor connections (A, B). This valve arrangement is characterised in that for each lock valve (16, 17) a pressure release valve (18, 19) is provided, whose operating member (30, 30 a) is loadable in the closing direction by a first chamber pressure and an additional force acting in a first chamber (31, 31 a) and in the opening direction by a control pressure acting in a second chamber (32, 32 a), and that the control pressure in dependence of the position of the control valve (9) has a lower value, which is equal to the first chamber pressure, and an upper value, which exceeds the first chamber value by such a value that the oppositely acting closing force is overcome. This gives a very high degree of operation safety.

The effect of some instrument operating conditions on the x-ray microanalysis of particles in the environmental scanning electron microscope

Abstract: The objective of this investigation was to evaluate the practical effects of electron beam broadening in the environmental scanning electron microscope (ESEM) on particle x-ray microanalysis and to determine some of the optimum operating conditions for this type of analysis. Four sets of experiments were conducted using a Faraday cage and particles of copper, glass, cassiterite, andrutile. The accelerating voltage and chamber pressure varied from 20 to 10 kV and from 665–66 Pa (5.0 to 0.5 torr), respectively. The standard gaseous secondary electron detectors (GSED) and the long environmental secondary dectectors (ESD) for the ESEM were evaluated at different working distances. The effect of these parameters on the presence of artifact peaks was evaluated. The particles were mounted on carbon tape on an aluminum specimen mount and were analyzed individually and as a mixture. Substrate peaks were present in almost all of the spectra. The presence of neighboring particle peaks and the number of counts in these depended upon the operating conditions. In general, few of these peaks were observed with the long ESD detector at 19 mm working distance and at low chamber pressures. More peaks and counts were observed with a deviation from these conditions. The most neighboring peaks and counts were obtained with the GSED detector at 21.5 mm working distance, 10 kV accelerating voltage, and 665 Pa (5.0 torr) chamber pressure. The results of these experiments support the idea that the optimum instrumental operating conditions for EDS analysis in the ESEM occur by minimizing the gas path length and the chamber water vapor pressure, and by maximizing the accelerating voltage. The results suggest that the analyst can expect x-ray counts from the mounting materials. These tests strongly support the recommendation of the manufacturer to use the long ESD detector and a 19 mm working distance for EDS analysis. The results of these experiments indicate that neighboring particles millimeters from the target may contribute x-ray counts to the spectrum.

Electrochemical device fabrication process with low temperature anneal

Abstract: A method of manufacturing an electrochemical device may comprise: depositing an electrode layer over a substrate using a physical vapor deposition (PVD) process in a deposition chamber, wherein the chamber pressure is greater than about 10 mTorr, and the substrate temperature is between about room temperature and about 450 °C or higher; and annealing the electrode layer for crystallizing the electrode layer, wherein the annealing temperature is less than or equal to about 450 °C, Furthermore, the chamber pressure may be as high as 100 mTorr. Yet furthermore, the post-deposition annealing temperature may be less than or equal to 400 °C. The electrochemical device may be a thin film battery with a LiCo02 electrode and the PVD process may be a sputter deposition process.