Craniometry was investigated in four samples of the red fox (
Vulpes vulpes
L. 1758) (
n
= 403) from Tver oblast. Factors affecting the metric polymorphism of the fox skull can be presented in the ...following order according to their significance: age, sex, geographic, and chronographic variability. The geographic and chronographic factors are correlated with the jaws and teeth. An analysis of the time interval from the early 1990s to the present shows a weak trend toward an increase in some cranial structures. However, the inclusion of material from the 1980s reveals a more complex trend in the chronographic variability with size fluctuations. This may be due to the high rate of mortality which determines the stochastic nature of the chronographic size variability. The spatial variability of odontological and craniometric characters can be of adaptive functional significance.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
•A bimodal distribution of aerosol on Mars has been inferred from solar occultations.•The coarser mode is represented by both dust and H2O ice particles with average radius of 0.7 and 1.2μm.•The ...finer mode with a radius of 0.04–0.07μm has been detected in both hemispheres.•The lack of condensation nuclei could not fully explain the high water supersaturation.•The finer mode is unstable against coagulation and requires a continuous source of particles to be maintained.
First simultaneous analysis of the ultraviolet (UV) and infrared (IR) atmospheric extinctions from SPICAM/Mars Express solar occultations in the beginning of the Northern summer (Ls=56–97°) is presented. The two SPICAM channels allow sounding of the martian atmosphere in the spectral range from 0.118 to 1.7μm at the altitudes from 10 to 80km. Based on Mie scattering theory with adequate refraction indices for dust and H2O ice, a bimodal distribution of aerosol has been inferred from the SPICAM measurements. The coarser mode is represented by both dust and H2O particles with average radius of 0.7 and 1.2μm, respectively, with number density from 0.01 to 10 particles in cm3. Clouds belonging to the aphelion cloud belt have been observed in midlatitudes in the Southern and the Northern hemispheres at altitudes of 20–30km. The clouds are formed of large particles, and their opacity in the UV and the IR is below 0.03. The finer mode with a radius of 0.04–0.07μm and a number density from 1cm−3 at 60km to 1000cm−3 at 20km has been detected in both hemispheres. In the Southern hemisphere the finer mode extends up to 70km, whereas in the Northern hemisphere it is confined below 30–40km. The lack of condensation nuclei is consistent, but could not fully explain the high water supersaturation observed between 30 and 50km in the same Northern hemisphere dataset (Maltagliati L., Montmessin, F., Fedorova, A., Korablev, O., Forget, F., Bertaux, J.-L. 2011. Science 333, 1868–1871). The average size of the fine mode (∼50nm) and the large number density (up to 1000cm−3) most likely corresponds to Aitken particles (r<0.1μm). This mode is unstable against coagulation and requires a continuous source of particles to be maintained, at least one order of magnitude more than estimations for the meteoric flux. A possible source is the dust lifting from the surface and dust devils. A detailed microphysical modeling is required to study the probability of survival of the observed bimodal distribution.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Acoustic signals coming from the human head during mental activity are experimentally studied. Acoustic signals that differ from the signals during relaxation are revealed. Calculation of the ...multiplication table in the mind is used as mental activity. It is shown that the differences are due to a variation in the breathing pattern. It is also shown that the most informative signals related to respiration are observed from the crown region (at a point close to
Cz
used in encephalography) and the signals related to pulse activity are observed from the temple region (at point
T
3
).
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Statistical distributions of exoplanets obtained by both ground-based and satellite telescopes are heavily distorted by observational selection. It is easier to detect massive planets orbiting close ...to the star, rather than planets of small masses and planets with large orbital periods. Low-mass planets with orbital periods of about a year or more, falling in the habitable zone of sun-like stars, cannot be detected by modern means. To account for this factor, we proposed and investigated the method of correcting the observational selection. It has been shown that the corrected mass distributions of exoplanets are well described by a piecewise power law. The result is in agreement with the conclusions of cosmogony and demonstrates a number of new features.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The Atmospheric Chemistry Suite (ACS) package is an element of the Russian contribution to the ESA-Roscosmos ExoMars 2016 Trace Gas Orbiter (TGO) mission. ACS consists of three separate infrared ...spectrometers, sharing common mechanical, electrical, and thermal interfaces. This ensemble of spectrometers has been designed and developed in response to the Trace Gas Orbiter mission objectives that specifically address the requirement of high sensitivity instruments to enable the unambiguous detection of trace gases of potential geophysical or biological interest. For this reason, ACS embarks a set of instruments achieving simultaneously very high accuracy (ppt level), very high resolving power (>10,000) and large spectral coverage (0.7 to 17 μm—the visible to thermal infrared range). The near-infrared (NIR) channel is a versatile spectrometer covering the 0.7–1.6 μm spectral range with a resolving power of ∼20,000. NIR employs the combination of an echelle grating with an AOTF (Acousto-Optical Tunable Filter) as diffraction order selector. This channel will be mainly operated in solar occultation and nadir, and can also perform limb observations. The scientific goals of NIR are the measurements of water vapor, aerosols, and dayside or night side airglows. The mid-infrared (MIR) channel is a cross-dispersion echelle instrument dedicated to solar occultation measurements in the 2.2–4.4 μm range. MIR achieves a resolving power of >50,000. It has been designed to accomplish the most sensitive measurements ever of the trace gases present in the Martian atmosphere. The thermal-infrared channel (TIRVIM) is a 2-inch double pendulum Fourier-transform spectrometer encompassing the spectral range of 1.7–17 μm with apodized resolution varying from 0.2 to 1.3 cm
−1
. TIRVIM is primarily dedicated to profiling temperature from the surface up to ∼60 km and to monitor aerosol abundance in nadir. TIRVIM also has a limb and solar occultation capability. The technical concept of the instrument, its accommodation on the spacecraft, the optical designs as well as some of the calibrations, and the expected performances for its three channels are described.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
This paper proposes a verification and calibration method for thermal imagers that consists in comparing temperature readings obtained by contact- and thermal imaging methods. In order to confirm the ...reliability of the proposed method, an experimental setup was developed, whose main element comprises an emitting surface in the form of a 330 × 200 × 4 mm rectangular plate covered with paint having an emissivity factor not less than 0.96. The paper presents the results of temperature field calculations on the plate’s emitting surface. The temperature field of the plate’s emitting surface was determined by the contact method using chromel-alumel thermocouples, as well as the thermal imaging method. As a result of the obtained temperature values analysis, it is concluded that the heat exchange of the plate with the ambient air starts to play a significant role when the temperature of the emitting surface approaches 50°C. Therefore, air heaters were applied in order to reduce the dissipation of heat from the emitting surface into the environment. These heaters are two aluminum-magnesium alloy plates attached to the end face of the emitting surface. The metal heat exchanger coils are installed on the surfaces of the plates and connected by hoses to the liquid thermostat. One of the plates heats the air flowing around the emitting surface, while the other prevents the thermal emission into the environment. As a result of the application of the heaters, the heat exchange intensity of the radiating surface of the plate with the environment decreases. Recommendations about the choice of heater sizes are given. The main advantages of the proposed method are the following: ensuring high isothermicity of the emitting surface throughout the thickness of the plate; accuracy of the temperature maintaining at a given level; reducing the transition time of the device to a steady-state regime.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Water escape on Mars has recently undergone a paradigm shift with the discovery of unexpected seasonal variations in the population of hydrogen atoms in the exosphere where thermal escape occurs and ...results in water lost to space. This discovery led to the hypothesis that, contradicting the accepted pathway, atomic hydrogen in the exosphere was not only produced by molecular hydrogen but mostly by high altitude water vapor. Enhanced presence of water at high altitude during southern spring and summer, due to atmospheric warming and intensified transport, favors production of H through photon‐induced ion chemistry of water molecules and thus appears to be the main cause of the observed seasonal variability in escaping hydrogen. This hypothesis is supported by the observation of large concentrations of water vapor between 50 and 150 km during the southern summer solstice and global dust events. Using a simplified yet representative air parcel transport model, we show that in addition to the formation of atomic hydrogen from water photolysis above 80 km, a major fraction of the exospheric hydrogen is formed at altitudes as low as 60 km and is then directly advected to the upper atmosphere. Comparing the injection modes of a variety of events (global dust storm, perihelion periods, and regional storm), we conclude that southern spring/summer controls H production and further ascent into the upper atmosphere on the long term with direct implication for water escape.
Plain Language Summary
Numerous lines of evidence suggest that Mars' water inventory was much larger in the past than it is today. The loss of this inventory has been driven by the formation of hydrated minerals on the surface, as well as by the escape of water to space. The first part of the escape process comprises the formation of H atoms, which may escape the planet once they reach the uppermost layers of the atmosphere. Here, we investigate one mechanism by which the H atoms may reach these high altitudes: the breakdown of water molecules by solar ultraviolet photons in the middle atmosphere (60–70 km above the surface), and the posterior ascent of the newly formed H atoms to the upper altitudes. We use a model that reveals that this process is the dominant contributor of atomic H to the upper atmosphere during periods of strong atmospheric circulation. In particular, we find that this mechanism is most efficient during the spring/summer season in the Southern Hemisphere, when Mars is closest to the Sun. Given that this season occurs every Martian year, our calculations suggest that this process has been the dominant contributor to water escape in the long term.
Key Points
We decipher hydrogen production and migration to Mars' upper atmosphere using a box model for a variety of elevated water vapor cases
H atoms formed between 60 and 80 km supply a dominant fraction of hydrogen to the upper atmosphere
Our results suggest that perihelion climate has a key role in the hydrogen transfer to the upper atmosphere overall
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
The light curves for almost 50 thousand stars with magnitudes
have been obtained over 2.5 years at SAO RAS in the process of conducting an exoplanet survey in roughly
-sized fields around the white ...dwarfs WD 0009
501 and GRW
708247. In this paper we present a catalog of variable stars that have been found in the considered regions. Periodogram analysis was used as the main variation search method. The catalog includes 150 periodic variable stars: 113 of them have been known previously, and for the remaining 37 variations have been discovered for the first time. These stars were classified according to the nature of the variations into four eclipsing variable and three pulsating types, as well as rotating stars. We present the periods and variation amplitudes in the range of
and
, determined from the investigated data.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Abstract
A model of a tube with a square cross-section was compiled for the mathematical analysis of the mesotube in Cartesian coordinates, with the selection of an element of a representative ...volume. To estimate the effective thermal conductivity of the structure, the generalized theory of conductivity with linearization of heat flux streamlines was used. The presence of anisotropy leads to the division of the problem into a separate estimate of the longitudinal and transverse thermal conductivity. The cross-section of the model was divided into elementary sections by a system of auxiliary adiabatic and isothermal planes, then the sections of the model were presented in the form of thermal resistances connected in chains - electrical circuits. Using the analogy of the identity of thermal and electrical resistances, the total conductivity of the sections and the effective thermal conductivity of the structure were determined. This methodology satisfies the test for limit transitions.
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