Effects Of Background Conditions Research Articles

Effects of Background Conditions on Lower Ionosphere Pre-heating Amplitude-modulation

基于电离层连续性方程和能量方程，建立了预加热模式下低电离层幅度调制加热理论模型，研究预加热阶段电离层电子密度和调制阶段电流随预加热时间的变化，探讨不同背景条件对幅度调制产生的极低频/甚低频（ELF/VLF）电磁波强度的影响.结果表明，预加热调制在90~100km高度效果较好，在夜间进行预加热调制激发的ELF/VLF强度增幅不明显，各季节中在春季调制强度增幅最大，太阳高年预加热调制比太阳低年的效果好，低纬地区强度增幅远大于中纬地区强度增幅.在一定加热条件下（有效辐射功率200MW，频率1kHz），不同背景条件（除夜间外）下的预加热幅度调制模式在考虑能耗情况下，均在预加热10s时效果最好.

The effect of background conditions on the ionospheric response to solar flares

AbstractThe ionospheric response to two X5 solar flares that occurred in different seasons was investigated using the global ionosphere‐thermosphere model. Two questions were investigated: (a) how do different solar flares with similar X‐ray peak intensities disturb the ionosphere during the same background and driving conditions? and (b) how do the geomagnetic field and season affect the ionospheric response to solar flares? These questions were investigated by exchanging the two X5 flares for each other so that there were two pairs of flares with (1) the same background conditions but different irradiances and (2) different background conditions but the same irradiance. The simulations showed that the different solar flares into the same background caused ionospheric disturbances of similar profiles but different magnitudes due to differences in the incident energies, while the same flare spectra caused perturbations of similar magnitudes but different profiles in different backgrounds. On the dayside, the response is primarily controlled by the total integrated energy of the flare, independent of the background. For the northern and southern polar regions, the response is strongly controlled by the solar zenith angle and the incident energy, while the background plays a secondary role. On the nightside, the background conditions, including the magnetic field and season, play a primary role, with the neutral winds and electrodynamics driving the ionospheric response.

Applicability of tire powder for the control of volatile organic compound emission in solid waste landfills: Sorption of volatile organic compounds onto tire powder

A series of batch tests using tire powder were performed to investigate the volatile organic compound (VOC) sorption behavior, and to evaluate the effect of surrounding conditions on the VOC sorption onto tire powder. Benzene, TCE, PCE, and ethylbenzene were selected as target VOCs. Sorption of VOCs onto tire powder was well explained by a linear (partitioning type) model. Target VOCs did not seem to compete with other VOCs significantly when sorbed onto tire powder for the range of concentrations tested. However, sorption of benzene was slightly suppressed in the presence of ethylbenzene. Solid effect was observed in sorption of benzene, TCE, and PCE. Tire-water partition coefficients of these VOCs decreased with increasing sorbent dosage and solid effect disappeared when sorbent dosage increased sufficiently. An appropriate tire powder dosage (≥10 g/L) should be used to preclude solid effect in measuring tire-water partition coefficients of VOCs. The effects of background conditions, such as temperature, pH, and ionic strength did not seem to be significant. Tire-water partition coefficients of VOCs, not tested in this study, could be estimated using a good logarithmic relationship between observed partition coefficients and octanol-water partition coefficients of VOCs tested.

Generation of visual fields for ergonomic design and evaluation

Among numerous factors that have an effect on the visual field, the effects of background conditions on the size of the visual field were investigated to obtain more practical visual fields that can be readily applicable to industrial settings. An experiment was conducted, in which the subject was instructed to search for a target with distinct orientations. Size contrast, nontarget density, and meridian, as experimental variables, showed a significant effect on the size of the visual field at α=0.01. The size of the three types of visual fields; stationary, eye, and head and eye fields, was linearly proportional to size contrast, and inversely proportional to nontarget density. The size of the visual fields on the horizontal axis was larger than that on the vertical axis, and the size of the head and eye field on the right meridian was also larger than that on the left meridian. The shape was found to be horizontally oriented oval and statistically non-symmetric with respect to both horizontal and vertical axes. The regression equations to predict the visual fields on the given background condition were suggested. The visual fields suggested in the study would be valuable to the design of visual displays and the panel layout of various displays and controls. Relevance to industry Guidelines to the design of displays, controls, and panel layouts are of great importance to designers in order to provide an ergonomically sound working environment to operators. In addition to the operator's anthropometry and task geometry, design factors that ensure proper interfaces would be a key element to successful design. Among the factors, operator's visual field has rarely been suggested in a practically applicable format. This study provides the designer with useful guidelines to the interface design of visual displays and panel layouts.