scholarly journals Study on Rail Short-Wave Irregularity of Speed Increased Tracks

2020 ◽  
Author(s):  
Jian Fang ◽  
Xiaoyan Lei ◽  
Songliang Lian ◽  
Wenwen Zheng
Keyword(s):  
Statistical Analysis ◽  
Field Test ◽  
Wave Length ◽  
Maximum Amplitude ◽  
Short Wave ◽  
Surface Irregularities ◽  
Standard Values ◽  
Test Points

The data obtained from a field test of irregularity of rail surface in Hu-Kun line, a CWR track, is processed by statistical analysis of maximum amplitude and one-third octave analysis. The result shows that the regularities of rail surface in joint areas of CWR track are worse in common. In general, the amplitudes of rail surface irregularities can get beyond 0.5mm/m, which exceed standard values in every wave length ranges, and the maximum of them can reach 15dB. The conditions of rail surface regularities in non-joint areas are better, and the rail surface irregularities from most of the test points are lower than 0.15mm/m, which do not exceed standard values.

scholarly journals On the absorption of light by crystals

1938 ◽  
Vol 167 (930) ◽  
pp. 384-391 ◽  
Keyword(s):  
Absorption Spectrum ◽  
Wave Length ◽  
Short Wave ◽  
Point Of View ◽  
Theoretical Point ◽  
Lattice Vibrations ◽  
Short Wave Length ◽  
Continuous Absorption ◽  
Absorption Of Light ◽  
Positive Hole

The purpose of this paper is to discuss the absorption of light by non-metallic solids, and in particular the mechanism by which the energy of the light absorbed is converted into heat. If one considers from the theoretical point of view the absorption spectrum of an insulation crystal, one finds that it consists of a series of sharp lines leading up to a series limit, to the short wave-length side of which true continuous absorption sets in (Peierls 1932; Mott 1938). In practice the lattice vibrations will broaden the lines to a greater of less extent. When a quantum of radiation is absorbed in the region of true continuous absorption, a free electron in the conduction band and a "positive hole" are formed with enough energy to move away from one another and to take part in a photocurrent within the crystal. When, however, a quantum is absorbed in one of the absorption lines , the positive hole and electron formed do not have enough energy to separate, but move in one another's field in a quantized state. An electron in a crystal moving in the field of a positive hole has been termed by Frenkel (1936) an "exciton".

scholarly journals On some short-wave equivalent height measurements of the ionized regions of the upper atmosphere

1930 ◽  
Vol 128 (807) ◽  
pp. 159-178 ◽  
Keyword(s):  
Wave Length ◽  
Good Deal ◽  
Short Wave ◽  
Wave Intensity ◽  
Upper Atmosphere ◽  
Frequency Change ◽  
Electronic Density ◽  
Short Waves ◽  
F Region ◽  
E Region

The present paper continues the account of wireless investigations of the ionized regions of the upper atmosphere given in two previous papers. The results discussed in it consist chiefly of measurements of the equivalent heights of the ionized regions made simultaneously at two or three receiving stations with wave-lengths of the order of 100 metres. The frequency-change method of measuring the equivalent height was used throughout. 2. Extension of Equivalent Height Measurements to the Use of Short Waves . The experiments described previously were continued with shorter wave-lengths with two objects in view. In the first place it had been found that 400-metre waves penetrated the lower ionized region (E region) only on certain nights, and then only during the few hours before dawn. This result clearly showed that penetration of this region was most likely when the density of ionization was least. But, according to most theories of wireless propagation, a greater electronic density is required to reflect or refract short waves than is the case with long waves, so that it was anticipated that by reducing the wave-length below 400 metres it might be possible to penetrate E region over a longer period of time during the night than had been possible when 400-metre waves had been used. In this way it was hoped to make a more detailed study of the variation of the equivalent height of the upper region (F region) which had been found to reflect 400-metre waves on the occasion when they had penetrated the normal E region. Secondly, since it is known that the attenuation of the ground waves increases rapidly as the wave-length is reduced below, say, 400 metres, it was expected that, with the use of shorter waves, the ratio of the values of downcoming wave intensity and ground wave intensity would be much increased at all stations. Such an increase, it was expected, would make it possible to continue the measurements of equivalent heights, in general, a good deal further into the daylight hours. Such daylight measurements on longer waves had previously been found difficult, because of the relative weakness of the intensity of the downcoming waves as compared with that of the ground waves.

scholarly journals The Bakerian lecture —Regularities and irregularities in the ionosphere—I

1937 ◽  
Vol 162 (911) ◽  
pp. 451-479 ◽  
Keyword(s):  
Specific Conductivity ◽  
Wave Length ◽  
Ground Level ◽  
Short Wave ◽  
The State ◽  
Total Conductivity ◽  
The Sun ◽  
Magnetic Studies ◽  
Short Wave Length ◽  
Radio Measurements

Our knowledge concerning the state of the atmosphere lying above about 80 km. in height has been derived from experiments on radio wave reflexion as well as from studies of terrestrial magnetism and of the aurora. The information derived from radio experiments is, fortunately, in the nature of a supplement to, rather than a duplicate of, information derivable in other ways. As one of the best examples in this connexion may be mentioned the question of electrical conductivity. Here the magnetic studies of Schuster and Chapman yield an estimate of the total conductivity for currents travelling horizontally, whereas the radio measurements give the state of ionization at different levels from which the specific conductivity at those levels may be estimated. One of the most striking things about the ionosphere is the marked solar control. Speaking generally it may be said that the ionization increases and decreases as the sun rises and sets. Again, speaking generally, we may say that the main part of the ionization is caused by solar-violet light. The rays from the sun meet the outer layers of the atmosphere first and the short wave-length radiation is absorbed there, causing ionization. It thus comes about that the study of the ionosphere becomes the study of an interesting part of the sun's spectrum which cannot be detected at ground level. It also becomes the study of certain atomic processes such as photo-ionization, recombination of ions and attachment of electrons to neutral molecules such as cannot be investigated at very low pressure in the laboratory, because of the influence of the walls of the vessel confining the gas.

scholarly journals Study the Effect of solvent on the Optical Properties Performance of active polymeric laser media

2007 ◽  
Vol 4 (3) ◽  
pp. 387-392
Author(s):  
Baghdad Science Journal
Keyword(s):  
Absorption Spectrum ◽  
Pure Water ◽  
Wave Length ◽  
Blue Shift ◽  
Short Wave ◽  
Fluorescence Yield ◽  
Effect Of Solvent ◽  
Long Wave ◽  
Short Wave Length ◽  
Laser Media

The paper include studies the effect of solvent of dye doped in polymeric laser sample which manufactured in primo press way, which is used as an active (R6G) tunable dye lasers. The remarks show that, when the viscosity of the solvent (from Pure Water to Ethanol), for the same concentration and thickness of the performance polymeric sample is increased, the absorption spectrum is shifts towards the long wave length (red shift), & towards short wave length (blue shift) for fluorescence spectrum, also increased the quantum fluorescence yield. The best result we obtained for the quantum fluorescence yield is (0.882) with thickness (0.25mm) in Ethanol solvent in concentration (2*10-3mole/liter), while when we used the Pure Water as a solvent, we found that the best quantum fluorescence yield is (0.72) at the same thickness & concentration of the sample.

The Results of Astroclimate Observations in the Short-Wave Length Interval of the Millimeter-Wave Range on the Suffa Plateau

2017 ◽  
Vol 59 (8-9) ◽  
pp. 763-771 ◽  
Author(s):  
G. M. Bubnov ◽  
Yu. N. Artemenko ◽  
V. F. Vdovin ◽  
D. B. Danilevsky ◽  
I. I. Zinchenko ◽  
...  
Keyword(s):  
Millimeter Wave ◽  
Wave Length ◽  
Short Wave ◽  
Short Wave Length ◽  
Millimeter Wave Range ◽  
Wave Range

THE REACTIONS OF THE HOUSEFLY, MUSCA DOMESTICA LINN., TO LIGHT OF DIFFERENT WAVE-LENGTHS

1938 ◽  
Vol 16d (11) ◽  
pp. 307-342 ◽  
Author(s):  
J. W. MacBain Cameron
Keyword(s):  
White Light ◽  
Copper Sulphate ◽  
Wave Length ◽  
Short Wave ◽  
Quantitative Relation ◽  
Copper Sulphate Solution ◽  
Quartz Mercury ◽  
Intensity Changes ◽  
Constant Quality ◽  
Colored Lights

Houseflies were reared on an artificial medium and tested with different wave-lengths of spectral light obtained from a quartz-mercury arc. The spectrum tested extended from λ3022 Å to λ5780 Å, and the lines were made of approximately equal intensity throughout. In addition, λ5461 Å and λ4078 Å were tested at several other intensities. The comparison standard in all cases was white light, obtained from a tungsten-filament, inside-frosted bulb, and filtered through copper sulphate solution. It was of constant quality, and the intensity was varied by changing the size of the bulb and by varying the distance from the bulb to the copper sulphate filter. The lighted areas to which the flies reacted were 5 by 10 mm. On one of these fell a total intensity of colored light of approximately 10.3 microwatts, on the other a range of intensity of white light of from 0.34 to 36.1 μw.Flies to be tested were removed from the breeding cage ten hours before tests began and were kept in darkness until used. Each fly whose record was used in compiling the final results was caused to make ten trips towards the two test lights, and a record was kept of the choice on each trip.A description and discussion of the four different methods found in the literature for conducting experiments of this type, and for analyzing the results, are included. In the first method, the intensity of the test light of a given wave-length is kept constant, while that of the standard light, usually white, is varied until both are equally attractive.The second method involves testing the colored light against a fixed intensity of white and finding the ratio of insects attracted to color. The intensity of white that will give the same ratio of attractiveness when tested against the standard is then determined.In the third method, the two test lights are made equal in intensity, and their relative efficiency is considered to be directly proportional to the number of insects attracted to each.In the last method, the standard is kept fixed in both quality and intensity, and the intensity of the test color is varied until the two are equal in attractiveness.Application of the first three methods to the same data shows that they give results that vary greatly as the intensity changes. Some show that efficiency increases as the intensity increases, while others show a decrease in efficiency with increasing intensity.If the intensities of all colored lights are equal, the three methods give practically the same qualitative results when applied to the same data. That is, a curve of efficiency is found which has its peak at the same wave-length, whatever method is used. Quantitatively, the results given by the three methods differ, so that no definite ratio of attractiveness can be determined between colors.The data obtained were not amenable to analysis by the fourth method, but published results indicate that this is perhaps the best method for determining the quantitative relation between the stimulative efficiencies of light of different colors.The housefly, M. domestica, is much more strongly stimulated by ultraviolet light of wave-length 3656 Å than by any other part of the spectrum examined. The effect decreases, at first rapidly and then more slowly, as the longer wave-lengths are reached; it also decreases on the short-wave side of the peak. The spectrum available extended only as far as λ3022 Å in the ultraviolet, at which point there was still an appreciable attractiveness, apparently greater than that of either yellow or green.Several problems are suggested that require further investigation.

A Novel Distribution of Visual Field Test Points to Improve the Correlation between Structure–Function Measurements

2012 ◽  
Vol 53 (13) ◽  
pp. 8396 ◽  
Author(s):  
Ryo Asaoka ◽  
Richard A. Russell ◽  
Rizwan Malik ◽  
David P. Crabb ◽  
David F. Garway-Heath
Keyword(s):  
Visual Field ◽  
Structure Function ◽  
Field Test ◽  
Visual Field Test ◽  
Test Points

Die Beeinflussung der Zellkerne in den Vorkeimen von Dryopteris filix-mas durch rote und blaue Strahlung

1963 ◽  
Vol 18 (7) ◽  
pp. 557-562 ◽  
Author(s):  
Rainer Bergfeld
Keyword(s):  
Protein Synthesis ◽  
Visible Light ◽  
Blue Light ◽  
External Factor ◽  
Wave Length ◽  
Red Light ◽  
Three Dimensional ◽  
Short Wave ◽  
Nuclear Volume ◽  
Short Wave Length

Morphogenesis and differentiation of fern gametophytes (Dryopteris filix-mas) are strongly controlled by light. “Normal” morphogenesis, i. e. formation of two- or three dimensional prothallia, can occur only under short wave length visible light (= blue light). In darkness and under long wave length visible light (= red light) the gametophytes will grow as filaments. The blue light dependent photoreactive system which controls morphogenesis seems to be located in the outer layers of the cytoplasm. The control of morphogenesis is causally connected with the increase of protein synthesis under the influence of blue light.In the present paper the influence of red and blue light on shape and volume of the nucleus in the fully grown basal cell of the young gametophyte of Dryopteris filix-mas has been investigated. In blue light the nuclei are more or less spherical, in red and in darkness they are spindle shaped. If the light quality is changed the shape of the nuclei is only slightly influenced; the nuclear volume, however, is drastically changed: increase of volume in the blue, decrease of nuclear volume in red and darkness. These reversible changes of nuclear volume under the influence of light, which are apparently correlated with changing rates of protein synthesis, are an impressive example for the control of nuclear properties by an external factor via the cytoplasm.

scholarly journals Comparison of Linear and Nonlinear Behavior of Track Elements in Contact-Impact Models

2018 ◽  
Author(s):  
Jabbar Ali Zakeri ◽  
Mosab Reza Tajalli
Keyword(s):  
Linear Model ◽  
3D Model ◽  
Linear Models ◽  
Wave Length ◽  
Short Wave ◽  
Contact Forces ◽  
Reliable Estimate ◽  
Impact Forces ◽  
Linear Behavior ◽  
Non Linear

Existence of short wave length irregularities and discontinuities in the rail, such as corrugation, isolated rail joints, crossings and rail breakage, result in impact forces and an increase in wheel-rail contact force. Extreme forces in such could result in non-linear behavior of ballast and pads, and as a result, employing common linear models mihgt over/under estimate contact forces. A 3D model of wheel and rail is developed in this paper, and by considering rail breakage, validity of linear models and considering non-linear behavior of materials are studied. Wheel-rail interactions are studied for two common pads with high stiffness (HDPE) and low stiffness (Studded) for speeds of 20 to 160 km/h. Three behavioral patterns are considered for the developed 3D model: linear pad and ballast (LP-LB), nonlinear pad and linear ballast (NLP, LB), and nonlinear pad and ballast (NLP, NLB), and results are compared. According to the results, for HDPE pads and impact forces of up to 30 tons, linear model for material could estimate acceptable results. Yet for studded pads, linear model estimates forces that are comparably less than those estimated by non-linear model. Moreover employing NLP-LB model overestimates pad and wheel-rail contact forces by a rather small margin, compared to those estimated by NLP-NLB model, and hence, could be a suitable replacement for it. It is also observed that in order to have a reliable estimate of ballast forces, using non-linear ballast models are mandatory, and neither LP-LB nor NLP-LB could be acceptable replacements.

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