Effect of gage size on the measurement of local heat flux

General formulas are derived for determining gage averaging errors of strip-type heat flux meters used in the measurement of one-dimensional heat flux distributions. In addition, a correction procedure is presented which allows a better estimate for the true value of the local heat flux. As an example of the technique, the formulas are applied to the cases of heat transfer to air slot jets impinging on flat and concave surfaces. It is shown that for many practical problems, the use of very small heat flux gages is often unnecessary

Geometrical correction factors for heat flux meters

General formulas are derived for determining gage averaging errors of strip-type heat flux meters used in the measurement of one-dimensional heat flux distributions. The local averaging error e(x) is defined as the difference between the measured value of the heat flux and the local value which occurs at the center of the gage. In terms of e(x), a correction procedure is presented which allows a better estimate for the true value of the local heat flux. For many practical problems, it is possible to use relatively large gages to obtain acceptable heat flux measurements

Finite element-integral simulation of static and flight fan noise radiation from the JT15D turbofan engine

An iterative finite element integral technique is used to predict the sound field radiated from the JT15D turbofan inlet. The sound field is divided into two regions: the sound field within and near the inlet which is computed using the finite element method and the radiation field beyond the inlet which is calculated using an integral solution technique. The velocity potential formulation of the acoustic wave equation was employed in the program. For some single mode JT15D data, the theory and experiment are in good agreement for the far field radiation pattern as well as suppressor attenuation. Also, the computer program is used to simulate flight effects that cannot be performed on a ground static test stand

Thermal distortion analysis of the space station solar dynamic concentrator

A method was developed to evaluate the thermal distortion of the Space Station Solar Dynamic Concentrator and the effects of thermal distortion on concentrator optical performance. The analytical method includes generating temperature distributions with TRASYS and SINDA models, interfacing the SINDA results with the SINDA-NASTRAN Interface Program (SNIP), calculating thermal distortion with a NASTRAN/PATRAN finite element model, and providing flux distribution maps within the receiver with the ray tracing OFFSET program. Temperature distributions, thermally induced slope errors, and flux distribution maps within the receiver are discussed. Results during a typical orbit indicate that temperatures of the hexagonal panels and triangular facets range between -18 and 99 C (-1 to 210 F), facet rotations are less than 0.2 mrad, and a change in facet radius due to thermal flattening is less than 5 percent. The predicted power loss with thermal distortion effects was less than 0.3 percent. The thermal distortion of the Solar Dynamic concentrator has negligible effect on the flux distribution within the receiver cavity

The Beetle Reference Manual: chip version 1.2

This paper details the electrical specifications, operating conditions and port definitions of the readout chip Beetle 1.2. The chip is developed for the LHCb experiment and fulfils the requirements of the silicon vertex detector (VELO, VETO), the silicon tracker and the RICH detector in case of multi-anode photomultiplier readout. It integrates 128 channels with low-noise charge-sensitive preamplifiers and shapers. The pulse shape can be chosen such that it complies with LHCb specifications: a peaking time of 25 ns with a remainder of the peak voltage after 25 ns of less than 30%. A comparator per channel with configurable polarity provides a binary signal. Four adjacent comparator channels are being ORed and brought off chip via LVDS ports. Either the shaper or comparator output is sampled with the LHC-bunch-crossing frequency of 40 MHz into an analog pipeline. This ring buffer has a programmable latency of max. 160 sampling intervals and an integrated derandomising buffer of 16 stages. For analog readout data is multiplexed with up to 40 MHz onto 1 or 4 ports. A binary readout mode operates at up to 80 MHz output rate on two ports. Current drivers bring the serialised data off chip. The chip can accept trigger rates of up to 1.1 MHz to perform a dead-timeless readout within 900 ns per trigger. For te stabi lity and calibration purposes, a charge injector with adjustable pulse height is implemented. The bias settings and various other parameters can be controlled via a standard I2C-interface. Appropriate design measures have been taken to ensure the radiation hardness against total ionising dose effects in excess of 10 Mrad. A robustness against Single Event Upset is achieved by redundant logic

Online gaming addiction: the role of sensation seeking, self-control, neuroticism, aggression, state anxiety and trait anxiety

Research into online gaming has steadily increased over the last decade, although relatively little research has examined the relationship between online gaming addiction and personality factors. This study examined the relationship between a number of personality traits (sensation seeking, self-control, aggression, neuroticism, state anxiety, and trait anxiety) and online gaming addiction. Data were collected over a 1-month period using an opportunity sample of 123 university students at an East Midlands university in the United Kingdom. Gamers completed all the online questionnaires. Results of a multiple linear regression indicated that five traits (neuroticism, sensation seeking, trait anxiety, state anxiety, and aggression) displayed significant associations with online gaming addiction. The study suggests that certain personality traits may be important in the acquisition, development, and maintenance of online gaming addiction, although further research is needed to replicate the findings of the present study

In Situ Cryo-Electron Tomography: A Post-Reductionist Approach to Structural Biology

Cryo-electron tomography is a powerful technique that can faithfully image the native cellular environment at nanometer resolution. Unlike many other imaging approaches, cryo-electron tomography provides a label-free method of detecting biological structures, relying on the intrinsic contrast of frozen cellular material for direct identification of macromolecules. Recent advances in sample preparation, detector technology, and phase plate imaging have enabled the structural characterization of protein complexes within intact cells. Here, we review these technical developments and outline a detailed computational workflow for in situ structural analysis. Two recent studies are described to illustrate how this workflow can be adapted to examine both known and unknown cellular complexes. The stage is now set to realize the promise of visual proteomics a complete structural description of the cell's native molecular landscape. (C) 2015 Elsevier Ltd. All rights reserved

Grating-coupled excitation of multiple surface plasmon-polariton waves

The excitation of multiple surface-plasmon-polariton (SPP) waves of different linear polarization states and phase speeds by a surface-relief grating formed by a metal and a rugate filter, both of finite thickness, was studied theoretically, using rigorous coupled-wave-analysis. The incident plane wave can be either p or s polarized. The excitation of SPP waves is indicated by the presence of those peaks in the plots of absorbance vs. the incidence angle that are independent of the thickness of the rugate filter. The absorbance peaks representing the excitation of s-polarized SPP waves are narrower than those representing p-polarized SPP waves. Two incident plane waves propagating in different directions may excite the same SPP wave. A line source could excite several SPP waves simultaneously