Elastic hadron scattering and optical theorem

All contemporary phenomenological models of elastic hadronic scattering have been based in principle on the assumption of optical theorem validity that has been overtaken from optics. It will be shown that the given theorem which has not been actually proved in particle physics cannot be applied to short-ranged strong interactions. The analysis of corresponding collision experiments is to be done under new basic assumptions. The actual progress in description of hadronic collision processes might then exist only if the initial states are specified on the basis of impact parameter values of colliding particles and probability dependence on this parameter is established, without limiting corresponding conclusion by optical theorem validity.Comment: 11 pages, improved text to emphasize invalidity of optical theorem in short-ranged hadronic collisions and the necessity of looking for some new description of elastic hadronic scattering which would not be based on this theore

Some factors affecting the efficiency of potato production, under Al–Ghab plain conditions, Syrian Arab Republic

ArticleData were collected by a field survey of 300 farmers from Al–Ghab region (Syria) during 2014–2015. The non–parametric Data Envelopment was used in analyzing the Technical efficiency. The relationship between farm size and production efficiency was considered. Technical efficiency amounted about 53% and most of farms are operating at low level of technical efficiency. The relationship between farm size and productivity efficiency is Non– linear, it decreases from small to medium farm size and then increases as the size increase. Large farms have the higher net farm income per thousand square metersand are the most efficient technically followed by small and medium farm size. To disclose that factors causing the technical efficiency, Two–limit Tobit Regression Model was used. The calculated results showed that, Household Size, Occupation, Farm Size, Experience in Farming, Seed Type and Membership are factors that cause the technical inefficiency potato farming at Al–Ghab region. Therefore, the Syrian Planning Board and Decision Makers should take this results into account when they draw their plans to improve farmer's skills by allocating more investment in farm research and extension programmers

New methods of generation of ultrashort laser pulses for ranging

To reach the millimeter satellite laser ranging accuracy, the goal for nineties, new laser ranging techniques have to be applied. To increase the laser ranging precision, the application of the ultrashort laser pulses in connection with the new signal detection and processing techniques, is inevitable. The two wavelength laser ranging is one of the ways to measure the atmospheric dispersion to improve the existing atmospheric correction models and hence, to increase the overall system ranging accuracy to the desired value. We are presenting a review of several nonstandard techniques of ultrashort laser pulses generation, which may be utilized for laser ranging: compression of the nanosecond pulses using stimulated Brillouin and Raman backscattering; compression of the mode-locked pulses using Raman backscattering; passive mode-locking technique with nonlinear mirror; and passive mode-locking technique with the negative feedback

Patterns of gene flow and selection across multiple species of Acrocephalus warblers: footprints of parallel selection on the Z chromosome

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Evolution of structure and local magnetic fields during crystallization of HITPERM glassy alloys studied by in situ diffraction and nuclear forward scattering of synchrotron radiation

Evolution of structure and local magnetic fields in Fe1 xCox 76Mo8Cu1B15 HITPERM metallic glass ribbons with various amounts of Co x 0, 0.25, 0.5 were studied in situ using diffraction and nuclear forward scattering of synchrotron radiation. It was found that crystallization for all three glasses proceeds in two stages. In the first stage, bcc Fe,Co nanocrystals are formed, while in the second stage additional crystalline phases evolve. For all three glasses, the crystallization temperatures at the wheel side were found to be lower than at the air side of the ribbon. The crystallization temperatures were found to decrease with increasing Co content. The lattice parameters of the bcc nanocrystals decrease up to about 550 C and then increase pointing to squeezing Mo atoms out of the nanograins or to interface effects between the nanocrystals and the glassy matrix. Nuclear forward scattering enabled separate evaluation of the contributions that stem from structurally different regions within the investigated samples including the newly formed nanocrystals and the residual amorphous matrix. Even minor Co content x 0.25 has a substantial effect not only upon the magnetic behaviour of the alloy but also upon its structure. Making use of hyperfine magnetic fields, it was possible to unveil structurally diverse positions of Fe atoms that reside in a nanocrystalline lattice with different number of Co nearest neighbour