scholarly journals Numerical modeling of strong effects on ionospheric plasma

2021 ◽  
pp. 165-169
Author(s):  
В.В. Медведев ◽  
В.Е. Еремичева ◽  
А.Д. Колин
Keyword(s):  
Anthropogenic Disturbance ◽  
Ionospheric Plasma ◽  
Theoretical Study ◽  
Nuclear Explosion ◽  
Physicochemical Processes ◽  
Neutral Gas ◽  
The Earth ◽  
Initial Stage ◽  
Subsequent Calculation ◽  
Electromagnetic Disturbances

В работе представлены постановка задачи начальной стадии мощного антропогенного возмущения ионосферы для последующего вычисления высотно-временного распределения ионосферно-магнитосферных параметров. Данная задача имеет огромное значение в плане теоретического исследования таких возмущений на математических моделях изучаемой среды. Такие возмущения сопровождаются различными физико-химическими процессами, которые к настоящему времени плохо изучены. Основным источником сильных возмущений ионосферы являются мощные электромагнитные излучения (сильная солнечная вспышка, мощный ядерный взрыв). Такие электромагнитные возмущения могут вызывать сильнейшие глобальные перераспределение всей атмосферы Земли, которые к настоящему времени недостаточно надежно изучены, и одним из способов их изучения, является математическое моделирование. Приводится результаты вычислительного эксперимента начальной стадии ионизации нейтрального газа, которые могут помочь в дальнейшем исследовании такого процесса. The paper presents the formulation of the problem of the initial stage of a powerful anthropogenic disturbance of the ionosphere for the subsequent calculation of the altitude-time distribution of the ionosphere-magnetospheric parameters. This problem is of great importance in terms of the theoretical study of such perturbations on mathematical models of the studied environment. Such disturbances are accompanied by various physicochemical processes, which are poorly understood by now. The main source of strong disturbances in the ionosphere are powerful electromagnetic radiation (strong solar flare, powerful nuclear explosion). Such electromagnetic disturbances can cause the strongest global redistribution of the entire atmosphere of the Earth, which by now have not been sufficiently studied reliably, and one of the ways to study them is mathematical modeling. The results of a computational experiment of the initial stage of ionization of a neutral gas are presented, which can help in further investigation of such a process.

scholarly journals Boundary conditions for the formation of the Moon

2015 ◽  
Vol 95 (2) ◽  
pp. 131-139 ◽  
Author(s):  
M. Reuver ◽  
R.J. de Meijer ◽  
I.L. ten Kate ◽  
W. van Westrenen
Keyword(s):  
Angular Momentum ◽  
Boundary Conditions ◽  
Total Angular Momentum ◽  
Nuclear Explosion ◽  
Moment Of Inertia ◽  
The Moon ◽  
Moon System ◽  
Giant Impact ◽  
The Earth ◽  
The Impact

AbstractRecent measurements of the chemical and isotopic composition of lunar samples indicate that the Moon's bulk composition shows great similarities with the composition of the silicate Earth. Moon formation models that attempt to explain these similarities make a wide variety of assumptions about the properties of the Earth prior to the formation of the Moon (the proto-Earth), and about the necessity and properties of an impactor colliding with the proto-Earth. This paper investigates the effects of the proto-Earth's mass, oblateness and internal core-mantle differentiation on its moment of inertia. The ratio of angular momentum and moment of inertia determines the stability of the proto-Earth and the binding energy, i.e. the energy needed to make the transition from an initial state in which the system is a rotating single body with a certain angular momentum to a final state with two bodies (Earth and Moon) with the same total angular momentum, redistributed between Earth and Moon. For the initial state two scenarios are being investigated: a homogeneous (undifferentiated) proto-Earth and a proto-Earth differentiated in a central metallic and an outer silicate shell; for both scenarios a range of oblateness values is investigated. Calculations indicate that a differentiated proto-Earth would become unstable at an angular momentum L that exceeds the total angular momentum of the present-day Earth–Moon system (L0) by factors of 2.5–2.9, with the precise maximum dependent on the proto-Earth's oblateness. Further limitations are imposed by the Roche limit and the logical condition that the separated Earth–Moon system should be formed outside the proto-Earth. This further limits the L values of the Earth–Moon system to a maximum of about L/L0 = 1.5, at a minimum oblateness (a/c ratio) of 1.2. These calculations provide boundary conditions for the main classes of Moon-forming models. Our results show that at the high values of L used in recent giant impact models (1.8 < L/L0 < 3.1), the proposed proto-Earths are unstable before (Cuk & Stewart, 2012) or immediately after (Canup, 2012) the impact, even at a high oblateness (the most favourable condition for stability). We conclude that the recent attempts to improve the classic giant impact hypothesis by studying systems with very high values of L are not supported by the boundary condition calculations in this work. In contrast, this work indicates that the nuclear explosion model for Moon formation (De Meijer et al., 2013) fulfills the boundary conditions and requires approximately one order of magnitude less energy than originally estimated. Hence in our view the nuclear explosion model is presently the model that best explains the formation of the Moon from predominantly terrestrial silicate material.

scholarly journals Precession and Nutations of Mars calculated with Kinoshita’s Model

1997 ◽  
Vol 165 ◽  
pp. 325-330 ◽  
Author(s):  
S. Bouquillon ◽  
J. Souchay
Keyword(s):  
Reference System ◽  
Theoretical Study ◽  
The Sun ◽  
Canonical Variables ◽  
The Earth

AbstractThis paper presents the theoretical study of precession and nutation of Mars in a rigourous way. For this work we choose a natural reference system, based on the concept of non-rotating origin, and the appropriate canonical variables. Then, we solve the equations of the problem by taking into account the effects of the Sun, the Earth, Jupiter, and satellites of Mars, Phobos and Deimos.

The Experimental Study on Consolidation of Acrylic Non-Aqueous Dispersion for Wet-Area Earthen Ruins in Southwest China

2013 ◽  
Vol 575-576 ◽  
pp. 327-330
Author(s):  
Yi Wu
Keyword(s):  
Southwest China ◽  
Water Resistance ◽  
Aqueous Dispersion ◽  
Northwest China ◽  
Soil Samples ◽  
Short Term ◽  
The Earth ◽  
Initial Stage ◽  
Peking University ◽  
Experimental Researches

It is a worldwide difficulty to preserve earth monument in wet area. To solve this problem, professor Zhou Shuanglin, an expert of earth monument preserving with College of Archaeology and Museum, Peking University, developed a consolidation agent named acrylic non-aqueous dispersion. But the study on this consolidation agent is still in its initial stage at present for most of its experimental researches are limited to northwest china and no research reports aimed at wet area in southwest China were found so far. To check out the efficiency of this consolidation agent in wet area, southwest China, a consolidating experiment was conducted by applying this consolidation agent to soil samples from kiln Qionglai earthen monuments located in outskirt of Chengdu city, the capital of Sichuan province. In this experiment, the changes of weight, permeating speed and short-term water resistance of specimens after consolidating were investigated and compared with those for northwest area. The study shows that acrylic non-aqueous dispersion consolidation agent developed by professor Zhou Shuanglin is also effective to a certain degree for the earth monument in wet area, southwest China.

The Experimental Study on Consolidating Effect of Acrylic Non-Aqueous Dispersion for Earthen Ruins in Southwest China’s Moist Areas

2013 ◽  
Vol 318 ◽  
pp. 360-363
Author(s):  
Wu Yi
Keyword(s):  
Southwest China ◽  
Water Resistance ◽  
Aqueous Dispersion ◽  
Northwest China ◽  
Soil Samples ◽  
Short Term ◽  
The Earth ◽  
Initial Stage ◽  
Peking University ◽  
Experimental Researches

It is a worldwide difficulty to preserve earth monument in wet area. To solve this problem, professor Zhou Shuanglin, an expert of earth monument preserving with College of Archaeology and Museum, Peking University, developed a consolidation agent named acrylic non-aqueous dispersion. But the study on this consolidation agent is still in its initial stage at present for most of its experimental researches are limited to northwest china and no research reports aimed at wet area in southwest China were found so far. To check out the efficiency of this consolidation agent in wet area, southwest China, a consolidating experiment was conducted by applying this consolidation agent to soil samples from kiln Qionglai earthen monuments located in outskirt of Chengdu city, the capital of Sichuan province. In this experiment, seeping speed, the changes of compressive strength and short-term water resistance of specimens after consolidating were investigated and compared with those for northwest area. The study shows that acrylic non-aqueous dispersion consolidation agent developed by professor Zhou Shuanglin is also effective to a certain degree for the earth monument in wet area, southwest China.

Luna-28 mission for polar samples return, as the key element of the initial stage of Russian Lunar Program

2020 ◽  
Author(s):  
Igor Mitrofanov ◽  
Lev Zelenyi ◽  
Vladislav Tretyakov
Keyword(s):  
Landing Site ◽  
Molecular Complexes ◽  
Radiation Environment ◽  
Polar Regions ◽  
Complex Molecules ◽  
The Earth ◽  
Initial Stage ◽  
Landing Sites ◽  
The Future ◽  
Robotic Missions

&lt;p&gt;The most interesting sites for future lunar outposts are thought to be located closely to poles, and South one is found to be more preferable.&amp;#160; But before humans could land there, the sequence of robotic missions should be implemented to study the natural environment at the selected sites, to deliver some supporting systems for ensuring conditions of habitability and also to test the innovated technology for Earth-Moon-Earth round trip.&lt;/p&gt;&lt;p&gt;Therefore, the Russian Lunar Program will be ignited by four robotic missions, which Russian Academy of Science has selected for the initial stage of this Program. Their names Luna-25 -28 were selected taking into account the name of the last Soviet lander Luna-24 of 1976. The objectives of these missions are critically important for accomplishment of the future polar expeditions of humans. The missions will conduct orbital mapping of polar regions with fine spatial resolution, measurements of radiation environment at the selected landing sites, testing of water and space volatiles in the polar regolith, and, in particular &amp;#8211; testing presence of complex molecules and pre-biotic molecular complexes, the lunar dust and exosphere, etc. Mobile elements of landing missions will investigate local areas around the landing sites to determine the best spots for the future habitation modules of human missions. In addition, the researches for the basic science will also be accomplished by these missions, such as the experiments for lunar-based astronomy at long wavelengths and at gamma-rays, the experiments for lunar seismology, for monitoring of interplanetary plasma and solar wind, etc.&lt;/p&gt;&lt;p&gt;The talk presents in details the concept of the key mission of the first stage of the Lunar Program, the Luna-28 mission for lunar polar sample return. The mission concept is based on the several basic requirements. The mission should have the return module for direct flight from Moon to Earth. The module should be able to deliver to the Earth a set of samples of polar regolith with the total mass of about 2 kilograms. They should be quarried from different depths of the shallow subsurface from several cm down to 1 meter. Samples should be delivered to the Earth with all volatiles, including water, in the frozen state. Small moonrover &amp;#8220;Lunokhod&amp;#8221; with mass below 100 kg should be delivered to the Moon by the lander. Before the launch of the return module, the rover could deliver remotely selected stones for return at the nearest vicinity of the lander, after the launch, the rover should conduct scientific studies of the area around the landing site.&lt;/p&gt;&lt;p&gt;The mission of Luna-28 will also be supported by the ground segment for proper curation of delivered samples and for their studies in the leading domestic and international research centers. The complex molecules and organic molecular complexes will be the main objects for these studies. &amp;#160;&amp;#160;&lt;/p&gt;

The Experimental Study on Consolidation of RTV for Wet-Area Earthen Ruins in Southwest China

2013 ◽  
Vol 457-458 ◽  
pp. 32-35
Author(s):  
Yi Wu
Keyword(s):  
Physical Chemistry ◽  
Experimental Study ◽  
Compressive Strength ◽  
Southwest China ◽  
Sichuan Province ◽  
Soil Samples ◽  
East China ◽  
The Earth ◽  
Initial Stage ◽  
Experimental Researches

It is a worldwide difficulty to preserve earth monument in wet area. To solve this problem, Physical Chemistry Institute of Zhejiang University in China developed a consolidation agent named RTV (organopolysiloxanes+tetraethylorthosilicate). But the study on this consolidation agent is still in its initial stage at present for most of its experimental researches are limited to east china and no research reports aimed at wet area in southwest China were found so far. To check out the efficiency of this consolidation agent for earth in wet area, southwest China, a consolidating experiment was conducted by applying this consolidation agent to soil samples from kiln Qionglai earthen monuments located in outskirt of Chengdu city, the capital of Sichuan province. In this experiment, the changes of weight, permeating speed and depth and compressive strength of specimens after consolidating were investigated and compared with those for northwest area. The study shows that RTV consolidation agent developed by Physical Chemistry Institute of Zhejiang University is also effective to a certain degree for the earth monument in wet area, southwest China.

The Experimental Study on Consolidation of Acrylic Non-Aqueous Dispersion for Kiln Qionglai Monuments in Chengdu, China

2013 ◽  
Vol 689 ◽  
pp. 368-371
Author(s):  
Wu Yi ◽  
Bing Jiang ◽  
Bin Jia
Keyword(s):  
Experimental Study ◽  
Compressive Strength ◽  
Southwest China ◽  
Aqueous Dispersion ◽  
Northwest China ◽  
Soil Samples ◽  
The Earth ◽  
Initial Stage ◽  
Hydrolysis Resistance ◽  
Experimental Researches

It is difficult to preserve earth monument in wet area. To solve this problem, a Chinese scholar, professor Zhou Shuanglin, developed a consolidation agent named acrylic non-aqueous dispersion. But the study on this consolidation agent is still in its initial stage, most of its experimental researches are limited to northwest china and no research reports aimed at southwest China wet area were found so far. To check out the efficiency of this consolidation agent in wet area, southwest China, a consolidating experiment was conducted by applying this consolidation agent to soil samples from kiln Qionglai earthen monuments located in outskirt of Chengdu city, the capital of Sichuan province. In this experiment, the changes of color, compressive strength and hydrolysis resistance of specimens after consolidating were investigated and compared with those for northwest area. The study shows that acrylic non-aqueous dispersion consolidation agent developed by professor Zhou Shuanglin is also effective to a certain degree for the earth monument in wet area, southwest China.

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