107 research outputs found

    X-ray diffraction and atomic force microscopy analysis of twinned crystals: rhombohedral canavalin

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    The structure of canavalin, the vicilin-class storage protein from jack bean, was refined to 1.7 A resolution in a highly twinned rhombohedral crystal of space group R3 and unit-cell parameters a = b = c = 83.0 A, alpha = beta = gamma = 111.1 degrees. The resulting R and R(free) were 0.176 and 0.245, respectively. The orthorhombic crystal structure (space group C222(1), unit-cell parameters a = 136.5, b = 150.3, c = 133.4 A) was also refined with threefold non-crystallographic symmetry restraints. R and R(free) were 0.181 and 0.226, respectively, for 2.6 A resolution data. No significant difference in the protein structure was seen between these two crystal forms, nor between these two and the hexagonal and cubic crystal forms reported elsewhere [Ko et al. (1993), Acta Cryst. D49, 478-489; Ko et al. (1993), Plant Physiol. 101, 729-744]. A phosphate ion was identified in the lumen of the C-terminal beta-barrel. Lattice interactions showed that the trimeric molecule could be well accommodated in both 'top-up' and 'bottom-up' orientations in a rhombohedral unit cell of the R3 crystal and explained the presence of a high twin fraction. The large inter-trimer stacking interface of the C222(1) crystal may account for its relative stability. Atomic force microscopy (AFM) investigations of the growth of three crystal forms of canavalin indicate the rhombohedral form to be unique. Unlike the other two crystal forms, it contains at least an order of magnitude more screw dislocations and stacking faults than any other macromolecular crystal yet studied, and it alone grows principally by generation of steps from the screw dislocations. The unusually high occurrence of the screw dislocations and stacking faults is attributed to mechanical stress produced by the alternate molecular orientations in the rhombohedral crystals and their organization into discrete domains or blocks. At boundaries of alternate domains, lattice strain is relieved by the formation of the screw dislocations

    ESTIMATING THE PROBABILITY OF THE EMERGENCY OPERATION OF THE QUARRY ELECTRIC LOCOMOTIVE TRACTION ELECTRIC DRIVE

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    The paper deals with the problem of the assessment of the functionality of the multi-motor direct current traction electric drive of the quarry electric locomotive. The problem of the failure of electric drive motors because of extremely unsatisfactory state of the rail tracks and the wear of wheel pairs is analyzed. Taking into account the number of the existing repaired electric motors the probability of fitting up the traction electric drive with the electric motors with the widest electrical parameters variety is determined.The paper deals with the problem of the assessment of the functionality of the multi-motor direct current traction electric drive of the quarry electric locomotive. The problem of the failure of electric drive motors because of extremely unsatisfactory state of the rail tracks and the wear of wheel pairs is analyzed. Taking into account the number of the existing repaired electric motors the probability of fitting up the traction electric drive with the electric motors with the widest electrical parameters variety is determined

    Кулачковий патрон

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    Кулачковий патрон, що містить корпус, виконаний з передньої і задньої частин з центральним отвором в його передній частині під плунжер, зв’язаний з приводом затиску, і отвори в передній частині корпуса, в яких розміщені опори важелів, важелі з приєднаними до них кулачками, штирі, розміщені в плунжері, що переміщаються у виконаних під кутом до осі патрона пазах важелів, який відрізняється тим, що важелі мають отвори, в яких розміщені осі з приєднаними до них з одного боку фасонними кулачками під різні діаметри закріплюваних заготовок, а з другого боку - конічними колесами з шліцьовими отворами під відповідні шліцові кінці осей, та можливістю зачеплення з циліндричним колесом, розташованим у виточці задньої частини корпуса, причому в одному з шліцьових пазів осей розташовано фіксатори, з пазами під виступи пластин, жорстко зв’язаних з плунжером та розташованих в його пазах

    VUV spectral line emission measurements in the TCABR tokamak

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    The study of tokamak plasma light emissions in the vacuum ultraviolet (VUV) region is an important subject since many impurity spectral emissions are present in this region. These spectral emissions can be used to determine the plasma ion temperature and density from different species and spatial positions inside plasma according to their temperatures. We have analyzed VUV spectra from 500 Å to 3200 Å wavelength in the TCABR tokamak plasma including higher diffraction order emissions. There have been identified 37 first diffraction order emissions, resulting in 28 second diffraction order, 24 third diffraction order, and 7 fourth diffraction order lines. The emissions are from impurity species such as OII, OIII, OIV, OV, OVI, OVII, CII, CIII, CIV, NIII, NIV, and NV. All the spectra beyond 1900 Å are from higher diffraction order emissions, and possess much better spectral resolution. Each strong and isolated spectral line, as well as its higher diffraction order emissions suitable for plasma diagnostic is identified and discussed. Finally, an example of ion temperature determination using different diffraction order is presented

    The limits of normal approximation for adult height

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    Adult height inspired the first biometrical and quantitative genetic studies and is a test-case trait for understanding heritability. The studies of height led to formulation of the classical polygenic model, that has a profound influence on the way we view and analyse complex traits. An essential part of the classical model is an assumption of additivity of effects and normality of the distribution of the residuals. However, it may be expected that the normal approximation will become insufficient in bigger studies. Here, we demonstrate that when the height of hundreds of thousands of individuals is analysed, the model complexity needs to be increased to include non-additive interactions between sex, environment and genes. Alternatively, the use of log-normal approximation allowed us to still use the additive effects model. These findings are important for future genetic and methodologic studies that make use of adult height as an exemplar trait

    Цанговый патрон

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    Цанговий патрон, що містить корпус, всередині якого встановлено затискний елемент у вигляді затискної цанги з байонетним замком, який з’єднує цангу з приводом затиску, який відрізняється тим, що затискна цанга виконана підпружиненою в осьовому напрямку з можливістю фіксації в радіальному напрямку підпружиненим пальцем, який охоплений обоймою з фігурною канавкою, а на хвостовику цанги виконані Г-подібні пази

    A New Standard of Ukraine: The Kupyna Hash Function

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    The Kupyna hash function was approved as the new Ukrainian standard DSTU 7564:2014 in 2015. Main requirements for it were both high security level and good performance of software implementation on general-purpose 64-bit CPUs. The new hash function uses Davies-Meyer compression function based on Even-Mansour cipher construction. Kupyna is built on the transformations of the Kalyna block cipher (Ukrainian standard DSTU 7624:2014). In this paper we present the adapted English translated specification of the Kupyna hash function as it is described in the national standard of Ukraine

    A New Encryption Standard of Ukraine: The Kalyna Block Cipher

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    The Kalyna block cipher was selected during Ukrainian National Public Cryptographic Competition (2007-2010) and its slight modification was approved as the new encryption standard of Ukraine in 2015. Main requirements for Kalyna were both high security level and high performance of software implementation on general-purpose 64-bit CPUs. The cipher has SPN-based (Rijndael-like) structure with increased MDS matrix size, a new set of four different S-boxes, pre- and postwhitening using modulo 2^{64} addition and a new construction of the key schedule. Kalyna supports block size and key length of 128, 256 and 512 bits (key length can be either equal or double of the block size). On the time of this paper publishing, no more effective cryptanalytic attacks than exhaustive search are known. In this paper we present the adapted English translated specification of Kalyna as it is given in the national standard of Ukraine

    Phenological shifts of abiotic events, producers and consumers across a continent

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    Ongoing climate change can shift organism phenology in ways that vary depending on species, habitats and climate factors studied. To probe for large-scale patterns in associated phenological change, we use 70,709 observations from six decades of systematic monitoring across the former Union of Soviet Socialist Republics. Among 110 phenological events related to plants, birds, insects, amphibians and fungi, we find a mosaic of change, defying simple predictions of earlier springs, later autumns and stronger changes at higher latitudes and elevations. Site mean temperature emerged as a strong predictor of local phenology, but the magnitude and direction of change varied with trophic level and the relative timing of an event. Beyond temperature-associated variation, we uncover high variation among both sites and years, with some sites being characterized by disproportionately long seasons and others by short ones. Our findings emphasize concerns regarding ecosystem integrity and highlight the difficulty of predicting climate change outcomes. The authors use systematic monitoring across the former USSR to investigate phenological changes across taxa. The long-term mean temperature of a site emerged as a strong predictor of phenological change, with further imprints of trophic level, event timing, site, year and biotic interactions.Peer reviewe
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