Self-cycling fluid heater

A self-cycling fluid heater is described which includes a high temperature upstream preheater for elevating the stream temperature. A high intensity jet arc heater heats the preheated fluid stream to ultrahigh reaction temperatures and discharges the stream into an electric resistance tubular heat exchanger. The heat exchanger has variations in wall thickness at measured intervals along its length to control the temperature of the fluid passing through the heat exchanger for desired time intervals to provide the specified chemical reactions desired

Modified thermocouple is effective from minus 250 deg to 5000 deg F

Modified, commercially available thermocouple which measures the temperature of a spacecraft heat shield, is capable of continuous measurement in the range of minus 250 deg to 5000 deg F. The modified thermocouples may be used inside metal treating furnaces in high temperature technology, and in certain corrosive environments

A parametric analysis of visual approaches for helicopters

A flight investigation was conducted to determine the characteristic shapes of the altitude, ground speed, and deceleration profiles of visual approaches for helicopters. Two hundred thirty-six visual approaches were flown from nine sets of initial conditions with four types of helicopters. Mathematical relationships were developed that describe the characteristic visual deceleration profiles. These mathematical relationships were expanded to develop equations which define the corresponding nominal ground speed, pitch attitude, pitch rate, and pitch acceleration profiles. Results are applicable to improved helicopter handling qualities in terminal area operations

Three roles of ideal theory

A teoria ideal rawlsiana pretende desempenhar diversos papéis na teoria não-ideal. Neste artigo, distingo entre três desses papéis e indago até que ponto podemos esperar que a teoria ideal seja capaz de realizá-los. Ela serve de baliza que deve guiar a produção de teoria não-ideal no longo prazo. É também suposto que ofereça uma forma de comparar diferentes injustiças e assim dizer-nos quando delas é a pior e, portanto, a que precisa mais urgentemente de uma solução. Por fim, a teoria ideal é a base para um modelo de equidade/justiça que limita o conjunto de medidas moralmente aceitáveis no âmbito da teoria não-ideal. Mostra-se aqui como os dois primeiros papéis – o de servir de baliza e o de [determinação] da urgência [relativa] – são menos plausíveis do que o papel em termos da equidade.Rawlsian ideal theory is meant to perform various roles in non-ideal theory. In this paper, I distinguish between three roles, and I consider the extent to which we can expect ideal theory to perform them. It is meant to serve as a target to guide non-ideal theorising in the long-term. It is also supposed to provide a way of comparing different injustices to tell us which is worst and therefore in most urgent need of a remedy. Finally, ideal theory is the basis for a model of fairness that restricts the set of morally permissible measures in non-ideal theory. I show how the first two roles—the target and urgency roles—are less plausible than the fairness role

An X-ray absorption spectroscopic study at the mercury LIII edge on phenylmercury(II) oxygen species

The X-ray absorption spectra of the reference and model compounds HgCl2, PhHgCl, PhHgOAc and [(PhHg)2OH][BF4].H2O have been analysed in both the XANES and EXAFS regions, and the technique was extended to determine the structures of (PhHg)2O, PhHgOH, and the basic salts PhHgOH.PhHgNO3 and PhHgOH.(PhHg)2SO4, which were previously structurally uncharacterised. Results indicate that (PhHg)2O is a molecular species with Hg-O-Hg 135°, while PhHgOH contains the [(PhHg)2OH]+ cation and is better formulated as [(PhHg)2OH]OH. The same cation is also featured in the two basic salts. Electrospray mass spectral studies of PhHgOH in aqueous solutions show that [PhHgOH2]+, [(PhHg)2OH]+ and [(PhHg)3O]+ co-exist in solution in a pH-dependent equilibrium

POINTWISE ESTIMATES FOR ROUGH OPERATORS WITH APPLICATIONS TO SOBOLEV INEQUALITIES

We investigate weighted Sobolev inequalities for rough operators. We prove that several operators satisfy a pointwise bound by the Riesz potential applied to the gradient. From this inequality, we derive several new Sobolev type inequalities with an operator on the left-hand side