The Experts below are selected from a list of 9 Experts worldwide ranked by ideXlab platform

Man Nguyen Tri Ho - One of the best experts on this subject based on the ideXlab platform.

  • Research gemology and mineralogy characteristics of Tektite in North region of Da Lat City
    Science and Technology Development Journal, 2017
    Co-Authors: Nang Ngoc Le, Oanh Thi Kim Pham, Man Nguyen Tri Ho
    Abstract:

    Tektite in northern of Da Lat city is a kind of natural glass, formed from Meteorite Collisions with Earth, have basic elements Si, Al, Fe, Mg. Typical shapes inclued debris, drops, oval, dumbbell, flat sphere, flat mace, short prism with external shape characterized by holes covering the surface. Typical color is black, sometimes brownish green at thin edges. The average density is about 1.45 g/cm3, a refractive index of about 1.50, with prolonged gas and the inclusion of carbonate, lechatelierite characteristic of natural glass. Tektite in Northern Dalat is proven to have a planetary origin that fits the hypothesis that they are formed by Meteorite impacts. Tektite in the area can be used in jewelry.

Nang Ngoc Le - One of the best experts on this subject based on the ideXlab platform.

  • Research gemology and mineralogy characteristics of Tektite in North region of Da Lat City
    Science and Technology Development Journal, 2017
    Co-Authors: Nang Ngoc Le, Oanh Thi Kim Pham, Man Nguyen Tri Ho
    Abstract:

    Tektite in northern of Da Lat city is a kind of natural glass, formed from Meteorite Collisions with Earth, have basic elements Si, Al, Fe, Mg. Typical shapes inclued debris, drops, oval, dumbbell, flat sphere, flat mace, short prism with external shape characterized by holes covering the surface. Typical color is black, sometimes brownish green at thin edges. The average density is about 1.45 g/cm3, a refractive index of about 1.50, with prolonged gas and the inclusion of carbonate, lechatelierite characteristic of natural glass. Tektite in Northern Dalat is proven to have a planetary origin that fits the hypothesis that they are formed by Meteorite impacts. Tektite in the area can be used in jewelry.

Oanh Thi Kim Pham - One of the best experts on this subject based on the ideXlab platform.

  • Research gemology and mineralogy characteristics of Tektite in North region of Da Lat City
    Science and Technology Development Journal, 2017
    Co-Authors: Nang Ngoc Le, Oanh Thi Kim Pham, Man Nguyen Tri Ho
    Abstract:

    Tektite in northern of Da Lat city is a kind of natural glass, formed from Meteorite Collisions with Earth, have basic elements Si, Al, Fe, Mg. Typical shapes inclued debris, drops, oval, dumbbell, flat sphere, flat mace, short prism with external shape characterized by holes covering the surface. Typical color is black, sometimes brownish green at thin edges. The average density is about 1.45 g/cm3, a refractive index of about 1.50, with prolonged gas and the inclusion of carbonate, lechatelierite characteristic of natural glass. Tektite in Northern Dalat is proven to have a planetary origin that fits the hypothesis that they are formed by Meteorite impacts. Tektite in the area can be used in jewelry.

Sz. Bérczi - One of the best experts on this subject based on the ideXlab platform.

  • The Source of Water Molecules in the Vicinity of the Moon
    2001
    Co-Authors: T. Földi, Sz. Bérczi
    Abstract:

    We suggest three continuous sources for the lunar water molecules: 1) from the small ice Meteorite Collisions to the lunar surface, 2) from terrestrial and solar hydrogen, which reaches Moon in the periodical lunar crossings of the Earth's magnetic and radiation tail, 3) from atomic H with energy higher then 1525 K in the vicinity of the Moon, which reduces the metallic oxides [1] on the surface and produces water molecules by this reduction. INTRODUCTION Since Lunar Prospector discovered water sources in the lunar polar regions the question of water and its possible accumulation became challenging. The existence of water implies the question of the ratio of sporadic influx of water (ice) versus the continuous transport of water (molecules). Although we shortly touch the possibility of ice Meteorites as water sources, we believe in the main role of the second possibility, the continuous influx of nanoparticle sized water containing components. 1. FROM ICE Meteorite IMPACT In the case of ice Meteorite impact, (which was not observed yet, only suggested), the impacting body is mixing and sublimating with the target materials, and cosmic concentrations of additive materials (i.e. NH3 component) can survive only perhaps in the conditions of Antarctica [2], [3], [4]. As compared terrestrial and lunar conditions the atmospheric pressure difference (10 to minus 15 atm) implies the escaping of all impacted water on the Moon. Because we believe in the accumulation of the slow continuous process for the water we study the two other possibilities in details. 2. FROM EARTH'S TAIL TO THE MOON It was found in electron-tube industry that water molecules may retain one negative electric charge. (Tungsram Factory, in 1935, Brody and Palocz [5].) On the inner surface of the electron tube, in hypervacuum, a monomolecular water molecule layer was found. This molecular water layer was negatively charged while the glass surface wall was positively charged. Later, Israel [6] found that the negatively charged water molecules have very longer lifetime, do not recombine, This lifetime is an order of magnitudes longer, then that of the small positive ions. Such charged water molecules can survive the cosmic travel time from the Earth upper atmosphere to the surface of the Moon. During full Moon the magnetic and radiation belts of the Earth sweep over the Moon. For the ionized and charged particles the "wall" of terrestrial magnetosphere tail behaves as a tube with reflecting walls. Together with ionized particles the water molecules, which have one negative electric charge (adhered to the water molecule) are also reflected on this tube wall. Therefore the charged water molecules do not escape from the tube but they travel till the Moon in the magnetic tail. The reflecting force from the wall is: v X B (where v is velocity, B is magnetic induction) the electrostatic accelerating force is e X E (where e is the electron charge unit, E is electric field strength in V/m) the acceleration by E is FE Electric Force per molecular mass. Let us follow the way of one water molecule in the terrestrial upper atmosphere. Because of the Brown motion neutral water molecular particles may get enough velocity to escape, if these particles get one electron which adhere them, then it will be transported to the magnetotail and remain inside the wall. Reaching the lunar surface the negatively charged water particle meets the positively charged (from UV radiation, [7]) dust particles. With charged dust particles water molecule forms a complex coagulated particle. At the same time, in the near vicinity of the lunar surface there exist a space charge of electron cloud, which recharge and so neutralize the coagulated particle. But this coagulated particle will not remain neutral for a long time, but it becomes charged again by the space charge of electron cloud. This periodic charging up and discharge 1) enlarges the coagulated particle, and 2) levitates the particle which will be the object of a transporting mechanism which moves it toward the lunar pole [7]. The step by step drag by the solar radiation pressure toward the poles, where agglutinated particles become discharged, results in their fall-down, and accumulate on the surface [7]. 3. BY REDUCTION OF LUNAR SURFACE ROCKS The solar flux consists mainly of two components: photons and protons. The photon flux emits electrons from the lunar surface soil. Because of the electron emission of the lunar surface it become positively charged. Because of this field charge of the lunar surface the overwhelming majority of the protons from the solar wind will deviate the surface. The very small part of the protons, before deviation, recombines in the electron cloud above the Lunar and Planetary Science XXXII (2001) 1148.pdf

T. Földi - One of the best experts on this subject based on the ideXlab platform.

  • The Source of Water Molecules in the Vicinity of the Moon
    2001
    Co-Authors: T. Földi, Sz. Bérczi
    Abstract:

    We suggest three continuous sources for the lunar water molecules: 1) from the small ice Meteorite Collisions to the lunar surface, 2) from terrestrial and solar hydrogen, which reaches Moon in the periodical lunar crossings of the Earth's magnetic and radiation tail, 3) from atomic H with energy higher then 1525 K in the vicinity of the Moon, which reduces the metallic oxides [1] on the surface and produces water molecules by this reduction. INTRODUCTION Since Lunar Prospector discovered water sources in the lunar polar regions the question of water and its possible accumulation became challenging. The existence of water implies the question of the ratio of sporadic influx of water (ice) versus the continuous transport of water (molecules). Although we shortly touch the possibility of ice Meteorites as water sources, we believe in the main role of the second possibility, the continuous influx of nanoparticle sized water containing components. 1. FROM ICE Meteorite IMPACT In the case of ice Meteorite impact, (which was not observed yet, only suggested), the impacting body is mixing and sublimating with the target materials, and cosmic concentrations of additive materials (i.e. NH3 component) can survive only perhaps in the conditions of Antarctica [2], [3], [4]. As compared terrestrial and lunar conditions the atmospheric pressure difference (10 to minus 15 atm) implies the escaping of all impacted water on the Moon. Because we believe in the accumulation of the slow continuous process for the water we study the two other possibilities in details. 2. FROM EARTH'S TAIL TO THE MOON It was found in electron-tube industry that water molecules may retain one negative electric charge. (Tungsram Factory, in 1935, Brody and Palocz [5].) On the inner surface of the electron tube, in hypervacuum, a monomolecular water molecule layer was found. This molecular water layer was negatively charged while the glass surface wall was positively charged. Later, Israel [6] found that the negatively charged water molecules have very longer lifetime, do not recombine, This lifetime is an order of magnitudes longer, then that of the small positive ions. Such charged water molecules can survive the cosmic travel time from the Earth upper atmosphere to the surface of the Moon. During full Moon the magnetic and radiation belts of the Earth sweep over the Moon. For the ionized and charged particles the "wall" of terrestrial magnetosphere tail behaves as a tube with reflecting walls. Together with ionized particles the water molecules, which have one negative electric charge (adhered to the water molecule) are also reflected on this tube wall. Therefore the charged water molecules do not escape from the tube but they travel till the Moon in the magnetic tail. The reflecting force from the wall is: v X B (where v is velocity, B is magnetic induction) the electrostatic accelerating force is e X E (where e is the electron charge unit, E is electric field strength in V/m) the acceleration by E is FE Electric Force per molecular mass. Let us follow the way of one water molecule in the terrestrial upper atmosphere. Because of the Brown motion neutral water molecular particles may get enough velocity to escape, if these particles get one electron which adhere them, then it will be transported to the magnetotail and remain inside the wall. Reaching the lunar surface the negatively charged water particle meets the positively charged (from UV radiation, [7]) dust particles. With charged dust particles water molecule forms a complex coagulated particle. At the same time, in the near vicinity of the lunar surface there exist a space charge of electron cloud, which recharge and so neutralize the coagulated particle. But this coagulated particle will not remain neutral for a long time, but it becomes charged again by the space charge of electron cloud. This periodic charging up and discharge 1) enlarges the coagulated particle, and 2) levitates the particle which will be the object of a transporting mechanism which moves it toward the lunar pole [7]. The step by step drag by the solar radiation pressure toward the poles, where agglutinated particles become discharged, results in their fall-down, and accumulate on the surface [7]. 3. BY REDUCTION OF LUNAR SURFACE ROCKS The solar flux consists mainly of two components: photons and protons. The photon flux emits electrons from the lunar surface soil. Because of the electron emission of the lunar surface it become positively charged. Because of this field charge of the lunar surface the overwhelming majority of the protons from the solar wind will deviate the surface. The very small part of the protons, before deviation, recombines in the electron cloud above the Lunar and Planetary Science XXXII (2001) 1148.pdf