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931.
A. V. Shchukin A. V. Il’inkov S. G. Dezider’ev S. N. Ivanov 《Russian Aeronautics (Iz VUZ)》2013,56(4):384-389
This paper reports the results of an experimental study of heat transfer using a model of the internal cooled surface of the turbine blade leading edge. We investigated a joint action of air jets and hemispherical protrusions on heat transfer from the concave surface of the leading edge model to air. 相似文献
932.
A.S. Laxmiprasad V.L.N. Sridhar Raja Surya Menon Adwaita Goswami M.V.H. Rao K.A. Lohar 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2013
A miniaturized in situ laser induced breakdown spectroscope-LIBS is one of the two lunar rover payloads to be flown in India’s next lunar mission Chandrayaan-2, with an objective to carry-out a precise qualitative and quantitative elemental analyses of lunar regolith at the proximity of the landing region. As per the imposed mission constraints and the executed design optimization studies, a compact and light-weight LIBS prototype model is developed at our premises. This paper mainly concerns with the estimation of theoretical aspects; especially on evaluation of elemental ablation parameters and signal-to-noise ratio (SNR) calculations for the designed instrument. Theoretical estimations and simulations yielded an incident laser power density of the order of 5 × 1010 W/cm2 on the target surface at a defined lens-to-surface distance (LTSD) of 200 mm and revealed an SNR > 100 for most of the elements under consideration. This paper also addresses the impact of LTSD variation on detection capability. The estimation of plasma-temperatures was carried out utilizing the emission spectra obtained under high vacuum environments employing the LIBS laboratory model. Experimental investigations and the performed theoretical estimations asserted the successful operation of the configured LIBS instrument for in situ elemental analyses on lunar surface. 相似文献
933.
S.N.V.S. Prasad P.V.S. Rama RaoD.S.V.V.D. Prasad K. VenkateshK. Niranjan 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2012
The Total Electron Content (TEC) from four locations in the Indian sector namely, Trivandrum (8.47°N, 76.91°E, Geomag.0.63°S, 0.3° dip), Waltair (17.7° N, 83.3°E, Geomag. 6.4°N, 20° dip), Bhopal (23.28°N, 77.34°E, Geomag.14.26°N, 33.2° dip), and Delhi (28.58°N, 77.21°E, Geomag.19.2°N, 43.4° dip) during a low sunspot year of 2004 are used to study the variabilities of the TEC. The day time TEC values are higher over Waltair and Bhopal compared to those at Trivandrum and Delhi. Considerable day-to-day variations in the diurnal values of TEC are observed at the anomaly crest locations. The observed GPS-TEC has been compared with the IRI-2007 model derived TEC considering three different options (IRI-2001, IRI-2001 corrected and Ne-Quick) available in the model for the topside electron density. The TEC derived with Ne-Quick and IRI-01 corrected options show better agreement with GPS-TEC while the TEC from IRI-01 method shows larger deviations. From the correlation analysis carried out between TEC value at 1300 h LT and solar indices parameters namely sunspot number (SSN), F10.7 and EUV, it is observed that the correlation is more during equinoctial months and less during summer months. The correlation coefficients observed over the anomaly locations, Bhopal and Delhi are lower compared to those at Trivandrum and Waltair. 相似文献
934.
J. Semkova R. Koleva St. Maltchev N. Bankov V. Benghin I. Chernykh V. Shurshakov V. Petrov S. Drobyshev I. Nikolaev 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2012
The Liulin-5 experiment is a part of the international project MATROSHKA-R on the Russian segment of the ISS, which uses a tissue-equivalent spherical phantom equipped with a set of radiation detectors. The objective of the MATROSHKA-R project is to provide depth dose distribution of the radiation field inside the sphere in order to get more information on the distribution of dose in a human body. Liulin-5 is a charged particle telescope using three silicon detectors. It measures time resolved energy deposition spectra, linear energy transfer (LET) spectra, particle flux, and absorbed doses of electrons, protons and heavy ions, simultaneously at three depths along the radius of the phantom. Measurements during the minimum of the solar activity in cycle 23 show that the average absorbed daily doses at 40 mm depth in the phantom are between 180 μGy/day and 220 μGy/day. The absorbed doses at 165 mm depth in the phantom decrease by a factor of 1.6–1.8 compared to the doses at 40 mm depth due to the self-shielding of the phantom from trapped protons. The average dose equivalent at 40 mm depth is 590 ± 32 μSV/day and the galactic cosmic rays (GCR) contribute at least 70% of the total dose equivalent at that depth. Shown is that due to the South Atlantic Anomaly (SAA) trapped protons asymmetry and the direction of Liulin-5 lowest shielding zone the dose rates on ascending and descending nodes in SAA are different. The data obtained are compared to data from other radiation detectors on ISS. 相似文献
935.
936.
Yu. G. Markov M. V. Mikhailov V. V. Perepelkin V. N. Pochukaev S. N. Rozhkov A. S. Semenov 《Cosmic Research》2016,54(2):155-163
The necessity of taking many force components disturbing spacecraft (SC) orbits into account is demonstrated for the example of forecasts of GLONASS ephemerides. The disturbances of SCs in high-earth orbits (HEO) and low-earth orbits (LEO) are systematized, and the degree of their effect on SC motion is estimated. Disturbance models are developed that provide essential increases of the accuracy of one-day forecasts of GLONASS and GPS ephemerides. Modeling results are presented that allow, depending on the required accuracy of SC orbit forecasts, the determination of the necessary list of disturbances included in the model. 相似文献
937.
M. I. Panasyuk S. I. Svertilov V. V. Bogomolov G. K. Garipov V. O. Barinova A. V. Bogomolov N. N. Veden’kin I. A. Golovanov A. F. Iyudin V. V. Kalegaev P. A. Klimov A. S. Kovtyukh E. A. Kuznetsova V. S. Morozenko O. V. Morozov I. N. Myagkova V. L. Petrov A. V. Prokhorov G. V. Rozhkov E. A. Sigaeva B. A. Khrenov I. V. Yashin S. I. Klimov D. I. Vavilov V. A. Grushin T. V. Grechko V. V. Khartov V. A. Kudryashov S. V. Bortnikov P. V. Mzhel’skiy A. P. Papkov S. V. Krasnopeev V. V. Krug V. E. Korepanov S. Belyaev A. Demidov Ch. Ferenz L. Bodnar P. Szegedi H. Rotkel M. Moravskiy Il Park Jin-A Jeon Ji-In Kim Jik Lee 《Cosmic Research》2016,54(4):261-269
The program of physical studies on the Vernov satellite launched on July 8, 2014 into a polar (640 × 830 km) solar-synchronous orbit with an inclination of 98.4° is presented. We described the complex of scientific equipment on this satellite in detail, including multidirectional gamma-ray detectors, electron spectrometers, red and ultra-violet detectors, and wave probes. The experiment on the Vernov satellite is mainly aimed at a comprehensive study of the processes of generation of transient phenomena in the optical and gamma-ray ranges in the Earth’s atmosphere (such as high-altitude breakdown on runaway relativistic electrons), the study of the action on the atmosphere of electrons precipitated from the radiation belts, and low- and high-frequency electromagnetic waves of both space and atmospheric origin. 相似文献
938.
Yu. T. Tsap A. V. Stepanov L. K. Kashapova I. N. Myagkova A. V. Bogomolov Yu. G. Kopylova T. B. Goldvarg 《Cosmic Research》2016,54(4):285-289
In 2001–2003, the X-ray and microwave observations of ten solar flares of M- and X-classes were carried out by the CORONAS-F orbital station, the RSTN Sun service, and Nobeyama radio polarimeters. Based on these observations, a correlation analysis of time profiles of nonthermal radiation was performed. On average, hard X-ray radiation outstrips the microwave radiation in 9 events, i.e., time delays are positive. The appearance of negative delays is associated with effective scattering of accelerated electrons in pitch angles, where the length of the free path of a particle is less than the half-length of a flare loop. The additional indications are obtained in favor of the need to account for the effect of magnetic mirrors on the dynamics of energetic particles in the coronal arches. 相似文献
939.
Yu N. Korenkov V.V. KlimenkoF.S. Bessarab 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2009
This paper presents the results of the numerical calculations thermosphere/ionosphere parameters which were executed with using of the Global Self-consistent Model of the Thermosphere, Ionosphere and Protonosphere (GSM TIP)and comparison of these results with empirically-based model IRI-2001. Model GSM TIP was developed in West Department of IZMIRAN and solves self-consistently the time-dependent, 3-D coupled equations of the momentum, energy and continuity for neutral particles (O2, N2, O), ions (O+, H+), molecular ions (M+) and electrons and largescale eletric field of the dynamo and magnetospheric origin in the range of height from 80 km to 15 Earth’s radii. The empirically derived IRI model describes the E and F regions of the ionosphere in terms of location, time, solar activity and season. Its output provides a global specification not only of Ne but also on the ion and electron temperatures and the ion composition. These two models represent a unique set of capabilities that reflect major differences in along with a substantial approaches of the first-principles model and global database model for the mapping ionosphere parameters. We focus on global distribution of the Ne, Ti, Te and TEC for the one moment UT and fixed altitudes: 110 km, hmF2, 300 km and 1000 km. The calculations were executed with using of GSM TIP and IRI models for August 1999, moderate solar activity and quiet geomagnetic conditions. Results present as the global differences between the IRI and GSM TIP models predictions. The discrepancies between model results are discussed. 相似文献
940.
S. Takechi K. Nogami T. Miyachi M. Fujii N. Hasebe T. Iwai S. Sasaki H. Ohashi H. Shibata E. Grün R. Srama N. Okada 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2009
A cosmic dust monitor for use onboard a spacecraft is currently being developed using a piezoelectric lead zirconate titanate element (PZT). Its characteristics of the PZT sensor is studied by ground-based laboratory impact experiments using hypervelocity particles supplied by a Van de Graaff accelerator. The output signals obtained from the sensor just after the impact appeared to have a waveform that was explicitly related to the particle’s impact velocity. For velocities less than ∼6 km/s, the signal showed an oscillation pattern and the amplitude was proportional to the momentum of the impacting particle. For higher velocities, the signal gradually changed to a single waveform. The rise time of this single waveform was proportional to the particle’s velocity for velocities above ∼6 km/s. The present paper reports on results for the low velocity case and especially discusses the effect of an outer coating of the sensor with a paint, which is used to reduce heating by solar radiation. 相似文献