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Static Structure (static + structure)

Distribution by Scientific Domains
Chemistry42%

Terms modified by Static Structure

  • static structure factor
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    Selected Abstracts

    Molecular dynamics study on effects of surface structures in nanometer scale on energy transfer from fluid to surface

    HEAT TRANSFER - ASIAN RESEARCH (FORMERLY HEAT TRANSFER-JAPANESE RESEARCH), Issue 3 2005
    Masahiko Shibahara
    Abstract Energy transfer from fluid to surface was calculated numerically by using the classical molecular dynamics method in order to investigate the effects of surface structures from 0.1 nm to 10 nm on surface energy transfer. Surface structures on a constant surface area were composed of several hundred atoms having various potential energy parameters, in other words, thermal properties. The upper region in the calculation domain was controlled at a constant temperature and one of the solid atomic layers at the lower region in the calculation domain was controlled at another constant temperature to create a temperature gradient in the calculation system. Energy transfer to the surface was very dependent on surface nanometer scale structures in that affected the static structure and the dynamic behaviors of fluid molecules in the vicinity of the surface. © 2005 Wiley Periodicals, Inc. Heat Trans Asian Res, 34(3): 171,179, 2005; Published online in Wiley InterScience (www.interscience. wiley.com). DOI 10.1002/htj.20055 [source]

    The threat of corporate groups and the insolvency connection

    INTERNATIONAL INSOLVENCY REVIEW, Issue 3 2009
    Alexander Dähnert, Article first published online: 27 OCT 200
    This paper attempts to shed some light on the issue referred to by the term ,group threat'. The factual appearance of corporate groups will be emphasized, as well as the question of what particular dangers arise from groups of legal entities. It will be argued that the source of group threats lies in the supremacy of group interest over the interests of affiliates, particularly in groups acting as a single unit. However, while efficiency gains inherent in group structures have attracted considerable attention in the debate about the insolvencies of corporate groups, the aspect of how the restriction of group threats can be reconciled with these efficiency-preservation concepts has been neglected. This appears of some concern given the fact that group threats and group synergy effects are part of the same coin. Both sides of the Janus-head ought to be considered in insolvency concepts and an attempt will be made to put the specific aspect of group threats into the wider context of group insolvencies. Existing approaches will be introduced, summarized and categorized, with a particular view taken of their common characteristics. It is argued that most insolvency concepts suffer from the same fundamental deficiencies: the focus on the structure of groups, which makes the very nature of integrated companies difficult to grasp. Consequently, this calls into question the application of these concepts and leads, furthermore, to significant collateral damage in the shape of principles central to company law. Resulting from these shortcomings and from the insight that the supremacy of the group interest constitutes the fundamental source of group characteristics, this paper suggests as an alternative that the focus be placed on wrongful conduct, the argument being that it is not the static structure, but the way the group is directed and ruled, which constitutes the decisive criterion for insolvency concepts. The understanding of group threats is therefore the key to a satisfactory approach to group specific challenges in insolvency. Copyright © 2009 John Wiley & Sons, Ltd. [source]

    Consistent treatment of inter- and intramolecular polarization in molecular mechanics calculations

    JOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 16 2002
    Pengyu Ren
    Abstract A protocol is described for the treatment of molecular polarization in force field calculations. The resulting model is consistent in that both inter- and intramolecular polarization are handled within a single scheme. An analytical formula for removing intramolecular polarization from a set of atomic multipoles for an arbitrary static structure or conformation is given. With the help of the intramolecular polarization, these permanent atomic multipoles can then be applied in modeling alternative conformations of a molecule. Equipped with this simple technique, one can derive transferable electrostatic parameters for peptides and proteins using flexible model compounds such as dipeptides. The proposed procedure is tested for its ability to describe the electrostatic potential around various configurations of the N -methylacetamide dimer. The effect of different intramolecular polarization schemes on the accuracy of a force field model of the electrostatic potential of alanine dipeptide is investigated. A group-based scheme for including direct intramolecular polarization is shown to be most successful in accounting for the conformational dependence of electrostatic potentials. © 2002 Wiley Periodicals, Inc. J Comput Chem 23: 1497,1506, 2002 [source]

    Chondrocranial development in larval Rana sylvatica (Anura: Ranidae): Morphometric analysis of cranial allometry and ontogenetic shape change

    JOURNAL OF MORPHOLOGY, Issue 2 2002
    Peter M. Larson
    Abstract This study provides baseline quantitative data on the morphological development of the chondrocranium in a larval anuran. Both linear and geometric morphometric methods are used to quantitatively analyze size-related shape change in a complete developmental series of larvae of the wood frog, Rana sylvatica. The null hypothesis of isometry was rejected in all geometric morphometric and most linear morphometric analyses. Reduced major axis regressions of 11 linear chondrocranial measurements on size indicate a mixture of allometric and isometric scaling. Measurements in the otic and oral regions tend to scale with negative allometry and those associated with the palatoquadrate and muscular process scale with isometry or positive allometry. Geometric morphometric analyses, based on a set of 11 chondrocranial landmarks, include linear regression of relative warp scores and multivariate regression of partial warp scores and uniform components on log centroid size. Body size explains about one-quarter to one-third of the total shape variation found in the sample. Areas of regional shape transformation (e.g., palatoquadrate, otic region, trabecular horns) are identified by thin-plate spline deformation grids and are concordant with linear morphometric results. Thus, the anuran chondrocranium is not a static structure during premetamorphic stages and allometric patterns generally follow scaling predictions for tetrapod cranial development. Potential implications regarding larval functional morphology, cranial development, and chondrocranial evolution in anurans are discussed. J. Morphol. 252:131,144, 2002. © 2002 Wiley-Liss, Inc. [source]

    Benign cysts in the central nervous system: Neuropathological observations of the cyst walls

    NEUROPATHOLOGY, Issue 1 2004
    Asao Hirano
    A diverse variety of benign cysts exist in the CNS. Advances in diagnostic radiology have facilitated diagnoses and surgical intervention in many patients with CNS cysts. However, a fundamental understanding of the pathological features of these lesions is clinically vital. From an etiological point of view, the cysts can be divided into two groups. The first includes lesions that arise from within the CNS and may be static structures such as cavities arising from infarcts and other destructive processes while other lesions such as arachnoid cysts, ependymal cysts, cystic hemangioblastoma, cystic cerebellar astrocytoma and infectious processes, are progressive. The second group of cysts arise from the intrusion of non-nervous system tissue into the neuroaxis and are usually midline. They are frequently expanding congenital lesions although some become symptomatic only in adults. Examples include teratomas, dermoid cysts, epidermoid cysts, craniopharyngiomas, Rathke's cleft cysts, and other epithelial cysts presumably derived from the upper respiratory or intestinal tract. Chick embryos exposed to lead have been used as a model of cyst formation. [source]

    Distance dependence and salt sensitivity of pairwise, coulombic interactions in a protein

    PROTEIN SCIENCE, Issue 5 2002
    Kelly K. Lee
    Abstract Histidine pKa values were measured in charge-reversal (K78E, K97E, K127E, and K97E/K127E) and charge-neutralization (E10A, E101A, and R35A) mutants of staphylococcal nuclease (SNase) by 1H-NMR spectroscopy. Energies of interaction between pairs of charges (,Gij) were obtained from the shifts in pKa values relative to wild-type values. The data describe the distance dependence and salt sensitivity of pairwise coulombic interactions. Calculations with a continuum electrostatics method captured the experimental ,Gij when static structures were used and when the protein interior was treated empirically with a dielectric constant of 20. The ,Gij when rij , 10 Å were exaggerated slightly in the calculations. Coulomb's law with a dielectric constant near 80 and a Debye-Hückel term to account for screening by the ionic strength reproduced the salt sensitivity and distance dependence of ,Gij as well as the structure-based method. In their interactions with each other, surface charges behave as if immersed in water; the Debye length describes realistically the distance where interactions become negligible at a given ionic strength. On average, charges separated by distances (rij) ,5 Å interacted with ,Gij , 0.6 kcal/mole in 0.01 M KCl, but ,Gij decayed to ,0.10 kcal/mole when rij = 20 Å. In 0.10 M KCl, ,Gij , 0.10 kcal/mole when rij = 10 Å. In 1.5 M KCl, only short-range interactions with rij , 5 Å persisted. Although at physiological ionic strengths the interactions between charges separated by more than 10 Å are extremely weak, in situations where charge imbalance exists many weak interactions can cumulatively produce substantial effects. [source]

    Beyond static structures of RNA by NMR: Folding, refolding, and dynamics at atomic resolution

    BIOPOLYMERS, Issue 5-6 2007
    Hashim M. Al-Hashimi
    No abstract is available for this article. [source]