Factors determining the observed values of the asymmetry coefficients of light fluxes in the atmosphere in the near-IR region

2018 ◽  
Keyword(s):  
Near Ir ◽  
The Asymmetry

scholarly journals THE PROGRAM FOR CALCULATING THE ASYMMETRY COEFFICIENTS OF AEROSOL SCATTERING IN THE RED AND NEAR IR REGIONS OF THE SPECTRUM

2021 ◽  
pp. 163-167
Author(s):  
В.В. Пашнев ◽  
Ю.Я. Матющенко ◽  
В.В. Белозерских ◽  
А.В. Калачев
Keyword(s):  
Block Diagram ◽  
Scattered Light ◽  
Atmospheric Parameters ◽  
Asymmetry Coefficient ◽  
Angular Variation ◽  
Acceptable Error ◽  
Near Ir ◽  
Aerosol Scattering ◽  
Calculation Results ◽  
The Asymmetry

В настоящей работе представлено программное обеспечение, реализующее методику определения аэрозольного коэффициента асимметрии из результатов наблюдений интегрального коэффициента рассеянных световых потоков, оптической толщи и альбедо местности интерполяционным путем без применения аппарата решения обратных задач. В качестве исходных используются данные измерений углового хода яркости дневного безоблачного неба в солнечном альмукантарате при разной спектральной прозрачности атмосферы и альбедо подстилающей поверхности. Наблюдения выполняются в длинах волн 675, 870 и 1020 нм при зенитных углах Солнца 65÷750, при этом яркость может измеряться в любых единицах, включая непосредственно отсчеты фотометра. При обработке результатов мониторинговых наблюдений даже на одной длине волны требуется производить значительное количество однотипных вычислений, что делает задачу автоматизации расчетов атмосферных параметров, в частности, коэффициентов асимметрии, безусловно актуальной. Изложены требования к входным данным, представлена блок-схема алгоритма и описание интерфейса пользователя программы. Результаты расчетов выводятся в табличной форме. Программаобеспечивает приемлемую погрешность определения коэффициентов асимметрии и может быть использована в геофизике и климатологии при проведении расчетов поступления рассеянной солнечной радиации на земную поверхность с целью последующей оценки размеров частиц. In this paper, software is presented that implements the method for determining the aerosol asymmetry coefficient from the results of observations of the integral coefficient of scattered light fluxes, optical depth and albedo of the terrain by interpolation without using an apparatus for solving inverse problems. The data of measurements of the angular variation of the brightness of the daytime cloudless sky in the solar almucantar with different spectral transparency of the atmosphere and the albedo of the underlying surface are used as the initial data. Observations are carried out at wavelengths of 675, 870 and 1020 nm at zenith angles of the Sun 65 ÷ 750, while the brightness can be measured in any unit, including directly the readings of the photometer. When processing the results of monitoring observations, even at one wavelength, it is required to perform a significant number of calculations of the same type, which makes the task of automating the calculations of atmospheric parameters, in particular, the asymmetry coefficients, undoubtedly relevant. Requirements for the input data are stated, a block diagram of the algorithm and a description of the user interface of the program are presented. The calculation results are displayed in tabular form. The program provides an acceptable error in determining the asymmetry coefficients and can be used in geophysics and climatology when calculating the arrival of scattered solar radiation on the earth's surface in order to further estimate the particle size.

Surface Brightness Scale of Galactic Cepheids

1999 ◽  
Vol 190 ◽  
pp. 561-562
Author(s):  
G. P. Di Benedetto
Keyword(s):  
Surface Brightness ◽  
Variable Stars ◽  
Giant Stars ◽  
Near Ir

An accurate calibration of the surface brightness scaleSVas a function of the near-IR color (V–K) has been recently measured for non-variable Galactic dwarf and giant stars. It can be shown that this correlation can be applied to theSVscale of Galactic Cepheid variable stars, which are of major cosmological interest.

Plasmon-assisted interaction of Si with light, for cancer hyperthermia and electromagnetic energy harvest

2020 ◽  
Vol 92 (2) ◽  
pp. 20101
Author(s):  
Behnam Kheyraddini Mousavi ◽  
Morteza Rezaei Talarposhti ◽  
Farshid Karbassian ◽  
Arash Kheyraddini Mousavi
Keyword(s):  
Silicon Nanowires ◽  
Metallic Nanoparticles ◽  
Near Infrared ◽  
Optical Transition ◽  
Electromagnetic Energy ◽  
Energy Harvest ◽  
Absorption Enhancement ◽  
Ir Absorption ◽  
Absorption Mechanism ◽  
Near Ir

Metal-assisted chemical etching (MACE) is applied for fabrication of silicon nanowires (SiNWs). We have shown the effect of amorphous sheath of SiNWs by treating the nanowires with SF6 and the resulting reduction of absorption bandwidth, i.e. making SiNWs semi-transparent in near-infrared (IR). For the first time, by treating the fabricated SiNWs with copper containing HF∕H2O2∕H2O solution, we have generated crystalline nanowires with broader light absorption spectrum, up to λ = 1 μm. Both the absorption and photo-luminescence (PL) of the SiNWs are observed from visible to IR wavelengths. It is found that the SiNWs have PL at visible and near Infrared wavelengths, which may infer presence of mechanisms such as forbidden gap transitions other can involvement of plasmonic resonances. Non-radiative recombination of excitons is one of the reasons behind absorption of SiNWs. Also, on the dielectric metal interface, the absorption mechanism can be due to plasmonic dissipation or plasmon-assisted generation of excitons in the indirect band-gap material. Comparison between nanowires with and without metallic nanoparticles has revealed the effect of nanoparticles on absorption enhancement. The broader near IR absorption, paves the way for applications like hyperthermia of cancer while the optical transition in near IR also facilitates harvesting electromagnetic energy at a broad spectrum from visible to IR.

NEAR IR FARADAY ROTATION ON YIG DOPED WITH TETRAVALENT AND PENTAVALENT ELEMENTS

1988 ◽  
Vol 49 (C8) ◽  
pp. C8-969-C8-970 ◽  
Author(s):  
F. D'Orazio ◽  
F. Giammaria ◽  
F. Lucari ◽  
G. Parone
Keyword(s):  
Faraday Rotation ◽  
Near Ir

Results of Spatial Structure of Atmosphere Radiation in a Spectral Range (1.5–2) µm Research

2018 ◽  
pp. 7-13
Author(s):  
Anton M. Mishchenko ◽  
Sergei S. Rachkovsky ◽  
Vladimir A. Smolin ◽  
Igor V . Yakimenko
Keyword(s):  
Spatial Structure ◽  
Unmanned Aerial Vehicle ◽  
Wavelength Range ◽  
Spectral Range ◽  
Near Ir ◽  
Optoelectronic Systems ◽  
Aerial Vehicle

Results of experimental studying radiation spatial structure of atmosphere background nonuniformities and of an unmanned aerial vehicle being the detection object are presented. The question on a possibility of its detection using optoelectronic systems against the background of a cloudy field in the near IR wavelength range is also considered.

EFFECT OF CELLULAR MEMBRANE RESISTIVITY INHOMOGENEITY ON THE THERMAL NOISE-LIMIT

2015 ◽  
Vol 11 (3) ◽  
pp. 3171-3183
Author(s):  
Gyula Vincze
Keyword(s):  
Field Strength ◽  
Thermal Noise ◽  
Cellular Membrane ◽  
Thermal Limit ◽  
Low Frequencies ◽  
Membrane Resistivity ◽  
Noise Limit ◽  
The Asymmetry ◽  
Characteristic Field

Our objective is to generalize the Weaver-Astumian (WA) and Kaune (KA) models of thermal noise limit to the case ofcellular membrane resistivity asymmetry. The asymmetry of resistivity causes different effects in the two models. In the KAmodel, asymmetry decreases the characteristic field strength of the thermal limit over and increases it below the breakingfrequency (10  m), while asymmetry decreases the spectral field strength of the thermal noise limit at all frequencies.We show that asymmetry does not change the character of the models, showing the absence of thermal noise limit at highand low frequencies in WA and KA models, respectively.

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