scholarly journals Investigation of Angular Spectrum of Scattered Inert Gas Ions from the InGaP (001) Surface

2021 ◽  
Vol 22 (4) ◽  
pp. 742-745
Author(s):  
M.K. Karimov ◽  
U.O. Kutliev ◽  
S.B. Bobojonova ◽  
K.U. Otabaeva

It has been shown that this method is quite suitable for surface studies and diagnostics of many component materials. The values of the azimuthal angle of distribution of Ne, Ar and Xe ions scattered from InGaP (001) <110> are obtained. The relationship between the spatial variables of the scattered beam (mainly azimuthal angular spectra) and the type of ions has been established. The correlation between focusing properties of surface semichannel with a type of bombardment ion at the different angle of incidence has been shown.    

2003 ◽  
Vol 94 (3) ◽  
pp. 1186-1192 ◽  
Author(s):  
G. Kim Prisk ◽  
Harold J. B. Guy ◽  
John B. West ◽  
James W. Reed

The analysis of the gas in a single expirate has long been used to estimate the degree of ventilation-perfusion (V˙a/Q˙) inequality in the lung. To further validate this estimate, we examined three measures ofV˙a/Q˙ inhomogeneity calculated from a single full exhalation in nine anesthetized mongrel dogs under control conditions and after exposure to aerosolized methacholine. These measurements were then compared with arterial blood gases and with measurements of V˙a/Q˙ inhomogeneity obtained using the multiple inert gas elimination technique. The slope of the instantaneous respiratory exchange ratio (R slope) vs. expired volume was poorly correlated with independent measures, probably because of the curvilinear nature of the relationship due to continuing gas exchange. When R was converted to the intrabreathV˙a/Q˙ (iV˙/Q˙), the best index was the slope of iV˙/Q˙ vs. volume over phase III (iV˙/Q˙slope). This was strongly correlated with independent measures, especially those relating to inhomogeneity of perfusion. The correlations for iV˙/Q˙ slope and R slope considerably improved when only the first half of phase III was considered. We conclude that a useful noninvasive measurement ofV˙a/Q˙ inhomogeneity can be derived from the intrabreath respiratory exchange ratio.


1964 ◽  
Vol 42 (8) ◽  
pp. 1455-1468 ◽  
Author(s):  
E. V. Jull

The diffraction of a plane electromagnetic wave by a perfectly conducting half-plane in an anisotropic plasma is considered. The plasma is characterized by a permittivity tensor and the wave is assumed to propagate in a direction normal to the magnetostatic field and the diffracting edge, but its angle of incidence is otherwise arbitrary. Only the H-polarized wave of the incident field, which has a single magnetic field component parallel to the edge, is affected by the anisotropy and the analysis is restricted accordingly. Representing the scattered field as an angular spectrum of plane waves leads to dual integral equations from which an expression for the scattered field is obtained. The total field is then reduced to Fresnel integrals and its far-field behavior is investigated. Agreement with Seshadri and Rajagopal's result for a wave normally incident on the conductor, which was obtained by using the Wiener–Hopf technique, is found. The differences between isotropic and anisotropic solutions to this problem, which arise from the differing boundary conditions on the tangential magnetic field, are examined.


1978 ◽  
Vol 44 (2) ◽  
pp. 277-283 ◽  
Author(s):  
G. R. Neufeld ◽  
J. J. Williams ◽  
P. L. Klineberg ◽  
B. E. Marshall

A computer model was developed to study the relationship between ventilation-to-perfusion (V/Q) mismatch and the development of inert gas arterial-to-alveolar partial pressure differences (a-A differences). Increasing inhomogeneity of V/Q ratio is revealed directly as an increase in the a-A difference of each gas. The quantitative relationships between the Q vs. V/Q distribution and the fractional a-A difference solubility plot (a-A difference plot) were studied and described. These studies demonstrated that for log normally distributed V/Q ratios, the area under the a-A difference plot is linearly related to the log variance of the V/Q distribution and can be estimated directly from the values obtained from six gases. The maximum a-A difference occurs for a gas whose solubility is numerically equal to the mean V/Q. The effects of departure from log normality and multimodality are discussed. We conclude from these studies that quantitative information regarding the degree of inhomogeneity of V/Q for log normal distribution is available from direct calculations of inert gas retention and excretion data. Qualitative information is also available indicating the departure from log normality and the region toward which the distribution is skewed.


2008 ◽  
Vol 26 (7) ◽  
pp. 1793-1803 ◽  
Author(s):  
A. R. Jacobson ◽  
R. Holzworth ◽  
X.-M. Shao

Abstract. We analyze data on radio-reflection from the D-region of the lower ionosphere, retrieving the energy-reflection coefficient in the frequency range ~5–95 kHz. The data are the same as developed for a recent study of ionospheric-reflection height, and are based on recordings of powerful (multi-Gigawatt) radio emissions from a type of narrow (~10 μs) lightning discharge known as "Narrow Bipolar Events". The sequential appearance of first the groundwave signal, and then the ionospheric single-hop reflection signal, permits us to construct the energy-reflection ratio. We infer the energy reflection's statistical variation with solar zenith angle, angle-of-incidence, frequency, and propagation azimuth. There is also a marginally-significant response of the energy reflectivity to solar X-ray flux density. Finally, we review the relationship of our results to previous published reports.


2017 ◽  
Vol 749 ◽  
pp. 251-256 ◽  
Author(s):  
Tadanori Sugino ◽  
Yuki Tashiro ◽  
Yasuo Yamane

The gloss of a metal surface is an important aspect for product quality evaluation. In general, gloss is influenced by specular reflection of light on a metal surface. Therefore, evaluating the specular reflection is almost the same as evaluating the gloss. We propose a method that uses patterned area illumination to evaluate specular reflection. In specular reflection, the angle of incidence equals the angle of reflection. Consequently, when light (ray) of the area illumination, which has a striped pattern, are projected on a glossy metal surface, a striped pattern forms on the reflected image as a mirror-like reflection, and the sharpness of the striped pattern of the image provides information about the specular reflection on the surface. This characteristic is applied to a metal with a hairline surface finish. A hairline surface presents different glossiness at different viewpoints. When the direction of the striped pattern of illumination is changed, the sharpness of striped pattern on the reflected image varies owing to the surface roughness of the hairline finish. Therefore, we can evaluate the glossiness in various directions by rotating the pattern. The rough relationships between gloss evaluation value and surface roughness were indicated in our study. In order to make the relationship between gloss evaluation and surface roughness for the estimation of surface roughness, we had tried the comparison for the gloss evaluation value and the surface roughness. The more precise relationship for seven directions on hairline-finished metal surface was measured. This report describes the results and considers the possibility of estimation of surface roughness by the gloss evaluation value.


1995 ◽  
Vol 400 ◽  
Author(s):  
Leonid V. Poperenko ◽  
Mykola V. Vinnichenko ◽  
Vasyl’ V. Vovchak ◽  
Iryna V. Yurgelevych ◽  
Sergei G. Zaichenko

AbstractThe experimental results of research of structural modifications in amorphous magnetic alloys (AMAs) under thermotreatment obtained by angular and spectroellipsometric methods are presented and discussed. The ductile-brittle transition was observed for the ribbons of some 3d-metal-based amorphous alloys. The relationship between the principal angle of incidence φ0 and annealing temperature Ta of alloys was obtained for the ribbons of AMAs. The observed behaviour of φ0 is connected with appearance of the novel amorphous phase’s clusters inside the surface’s layers of alloys.The influence of melt’s overheating on the atomic and electronic structure of AMAs was studied. It was found that the increase of melt’s overheating temperature leads to the decrease of absorption index within the whole spectral range (ħω=0.5–4.38 eV). The structural anisotropy of AMAs and its changes after annealings were determined by reflectometric and ellipsometric measurements.


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