48,639 research outputs found

    Interactions of satellite-speed helium atoms with satellite surfaces. 3: Drag coefficients from spatial and energy distributions of reflected helium atoms

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    Spatial and energy distributions of helium atoms scattered from an anodized 1235-0 aluminum surface as well as the tangential and normal momentum accommodation coefficients calculated from these distributions are reported. A procedure for calculating drag coefficients from measured values of spatial and energy distributions is given. The drag coefficient calculated for a 6061 T-6 aluminum sphere is included

    Application of Relativistic Coupled-cluster Theory to Electron Impact Excitations of Mg+^+ in the Plasma Environment

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    A relativistic coupled-cluster (RCC) theory is implemented to study electron impact excitations of atomic species. As a test case, the electron impact excitations of the 3s 2S1/2−3p 2P1/2;3/23s ~ ^2S_{1/2} - 3p ~ ^2P_{1/2;3/2} resonance transitions are investigated in the singly charged magnesium (Mg+^+) ion using this theory. Accuracies of wave functions of Mg+^+ are justified by evaluating its attachment energies of the relevant states and compared with the experimental values. The continuum wave function of the projectile electron are obtained by solving Dirac equations assuming distortion potential as static potential of the ground state of Mg+^+. Comparison of the calculated electron impact excitation differential and total cross-sections with the available measurements are found to be in very good agreements at various incident electron energies. Further, calculations are carried out in the plasma environment in the Debye H\"uckel model framework, which could be useful in the astrophysics. Influence of plasma strength on the cross-sections as well as linear polarization of the photon emission in the 3p 2P3/2−3s 2S1/23p ~ ^2P_{3/2} - 3s ~ ^2S_{1/2} transition is investigated for different incident electron energies.Comment: 9 pages, 1 table and 3 figure

    Effect of nutrients sprays on growth, yield and fruit quality of apple under cold desert condition of Himachal Pradesh

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    The on farm trial was carried out to study the effect of nutrients sprays on growth, yield and fruit quality of apple cv. Royal Delicious under cold desert condition of Himachal Pradesh. Treatments comprised spray of boric acid (0.1%), urea (0.5%), boric acid (0.1%) + urea (0.5%), multiplex (250 ml/100 litre of water) and no use of nutrients (water spray). The highest growth in terms of shoot length was observed with spray of urea at 0.5% and the highest fruit set and yield were recorded with boric acid (0.1%) + urea (0.5%) followed by boric acid at 0.1%. The lowest growth, fruit set and yield were observed with control. The combination of boric acid (0.1%) + urea (0.5%) resulted in the highest fruit length, breadth and weight. The highest total soluble solids were recorded with boric acid 0.1% and the reducing and total sugars were the highest with control. The acidity was found maximum while total soluble solids, reducing and total sugars were recorded lowest with spray of urea 0.5%. The treatment comprising of boric acid (0.1%) + urea (0.5%) proved to be best in terms of fruit set, yield and quality parameters of apple followed by boric acid at 0.1% concentration

    The BCS theory of q-deformed nucleon pairs - qBCS

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    We construct a coherent state of q-deformed zero coupled nucleon pairs distributed in several single-particle orbits. Using a variational approach, the set of equations of qBCS theory, to be solved self consistently for occupation probabilities, gap parameter Delta, and the chemical potential lambda, is obtained. Results for valence nucleons in nuclear degenerate sdg major shell show that the strongly coupled zero angular momentum nucleon pairs can be substituted by weakly coupled q-deformed zero angular momentum nucleon pairs. A study of Sn isotopes reveals a well defined universe of (G, q) values, for which qBCS converges. While the qBCS and BCS show similar results for Gap parameter Delta in Sn isotopes, the ground state energies are lower in qBCS. The pairing correlations in N nucleon system, increase with increasing q (for q real).Comment: 8 pages, REVTEX, 3 eps figure
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