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Wagner-Vengrenovich Distribution  [PDF]
Bohdan V. Ivanskii,Anatolii V. Moskalyuk,Sergey V. Yarema,Igor I. Panko,Miroslav O. Stasyk
ISRN Nanomaterials , 2013, DOI: 10.1155/2013/651576
Abstract: The process of coarsening of nanoclusters or nanocrystals (NCs) is investigated for the case when cluster growth (dissolution) is governed simultaneously by both diffusion along dislocation pipes and the rate of formation of chemical connections (chemical reaction) at cluster surface, namely, Wagner’s growing mechanism. For that, the total flow of atoms to (from) a cluster is represented by two parts, namely, diffusion part and the Wagner (kinetic) one. The dependence of the rate of growth of NC on the ratio of the parts of the total flow has been determined as well as the NC’s size distribution function referred to as the Wagner-Vengrenovich distribution. Computed distribution is compared with experimentally obtained histograms. 1. Introduction Ostwald’s ripening (OR) is the final stage of formation of a new phase as a result of phase transformation, such as decay of oversaturated solid solutions. Nanoclusters or nanocrystals (NCs) of new phase having different sizes interact through the Gibbs-Thomson effect that results in dissolution of small NC and growth of large ones. Diffusion growth of NC under matrix of volume diffusion (ls-mechanism) has been firstly studied by Lifshitz and Slyozov [1, 2]. Wagner has showed later [3] that beside diffusion mechanism, another mechanism of NC growth is possible, which is governed by the rate of formation of chemical connections (chemical reaction) at NC surface (w-mechanism). The theory developed in the cited papers is referred to as the LSW theory. Practical verification of this theory shows that in many cases, it is proper for the description of experimental data on temporal behavior of the mean NC size and the NC size the distribution function, while in other cases the LSW theory must be refined. In this connection, NC growth is considered in papers [4, 5] as a result of combined action of two growing mechanisms, diffusion (ls) and Wagner’s (w) ones. In the framework of the modified LSW theory and taking into account both mechanisms of growing (ls and w), we can obtain a size distribution in the form of the generalized Lifschitz-Slyozov-Wagner distribution [4]. This distribution can refer to a much wider range of the experimental histograms than each of the Lifschitz-Slyozov (LS) and Wagner’s ( ) distributions separately. The products of nanotechnologies [6–8] become new objects of applying the LSW theory. As sizes become 100?nm and less [9], the characteristics of both separate NCs and of the system as a whole change cardinally that provides practically useful properties. The OR is among probable factors
Roy Walford and the immunologic theory of aging
Rita B Effros
Immunity & Ageing , 2005, DOI: 10.1186/1742-4933-2-7
Abstract: Dr. Roy Walford, M.D. Professor Emeritus of Pathology and Laboratory Medicine at UCLA, died on April 27, 2004 after a long battle with amyotrophic lateral sclerosis. He joined UCLA's faculty in 1954 and became Professor of Pathology in 1966. He is widely regarded as a pioneer in the study of the biology of aging. He and his colleagues have made major contributions to several areas of experimental gerontology including caloric restriction, immunological aging and the role of body temperature reduction in aging retardation. Early in his career he was also a leader in the study of histocompatibility systems. Last year a special issue of Experimental Gerontology was dedicated to Roy Walford. In that volume, the comments of several colleagues with whom Roy interacted in fundamental areas of immunology provided evidence of the admiration and respect with which he was viewed. For example, the eminent Nobel Laureate, Professor Jean Dausset, honored for his contributions to the field of human leukocyte antigen biology, which is central to immune function, described Roy as "brilliant..... original....lucid visionary of the future" [1]. Dr. Edwin Cooper expressed his gratitude for the novel contributions to immunosenescence derived from his interactions with Roy in the study of lower animals and phylogenetic analyses [2]. The collaboration between Roy and Dr. G.B. Ferrara in identifying the so-called "Merrit alloantigen system", now known as MHC Class II, were of fundamental importance in both transplant immunology and more recently, in understanding antigen presentation. Dr. Ferrara described Roy as "an extraordinary man: genius, scientist, philosopher, artist, predictor of the events of our time" [3]. This unusual foresight and intuition probably played a role in the fact, as stated by immunologist Dr. Richard Miller, that Roy was among the first "to note and promote the powers of modern immunological approaches as tools for the analysis of ageing" [4]. Thus, Roy has played
Roy-Steiner equations for $γγ\toππ$  [PDF]
Martin Hoferichter,Daniel R. Phillips,Carlos Schat
Physics , 2011,
Abstract: Starting from hyperbolic dispersion relations, we present a system of Roy--Steiner equations for pion Compton scattering that respects analyticity and unitarity requirements, gauge invariance, as well as crossing symmetry, and thus all symmetries of the underlying quantum field theory. To suppress the dependence on the high-energy region, we also consider once- and twice-subtracted versions of the equations, where the subtraction constants are identified with dipole and quadrupole pion polarizabilities. We consider the resolution of the $\gamma\gamma\to\pi\pi$ partial waves by a Muskhelishvili-Omn\`es representation with finite matching point, and discuss the consequences for the two-photon coupling of the $\sigma$ resonance as well as its relation to pion polarizabilities.
Roy, Jo lle. Xman est back en Huronie  [cached]
Gabrielle Bonifaci
Voix Plurielles , 2012,
Abstract: Roy, Jo lle. Xman est back en Huronie. Compte rendu
The Wagner Curvature Tensor in Nonholonomic Mechanics  [PDF]
Vladimir Dragovic,Borislav Gajic
Physics , 2003, DOI: 10.1070/RD2003v008n01ABEH000229
Abstract: We present the classical Wagner construction from 1935 of the curvature tensor for completely nonholonomic manifolds in both invariant and coordinate way. The starting point is the Shouten curvature tensor for nonholonomic connection introduced by Vranceanu and Shouten. We illustrate the construction on two mechanical examples: the case of a homogeneous disc rolling without sliding on a horizontal plane and the case of a homogeneous ball rolling without sliding on a fixed sphere. In the second case we study the conditions on the ratio of diameters of the ball and the sphere to obtain a flat space - with the Wagner curvature tensor equal zero.
Emmanuel Le Roy Ladurie e a vis o de história dos annales
Tiago de Melo Goes
Diálogos , 2010, DOI: 10.4025/dialogos.v12i1.38
Abstract: O presente artigo estuda a obra de Emmanuel Le Roy Ladurie como forma de avan ar na compreens o de duas quest es relativas à tradi o dos Annales: a abordagem da história política e a maneira pela qual a escola articulou os diversos elementos do todo social (econ mico, demográfico, social, etc.). This article focuses on Emmanuel Le Roy Ladurie’s oeuvre as an effort to further the understanding of two central issues to the Annales school: the approach of politics and the way in which the school articulated the different elements of society (economics, demography, social, etc.). El presente artículo estudia la obra de Emmanuel Le Roy Ladurie como una forma de avanzar en la comprensión de dos cuestiones relativas a la tradición historiográfica de la Escuela de los Annales: por un lado, el abordaje dado a la historia política y, por otro, la manera en que la Escuela entrelazó los diversos elementos del todo social (económico, demográfico, político, etc.).
The Roy Adaptation Model and Content Analysis
Aquichán , 2006,
Abstract: the purpose of this paper is to explain how the roy adaptation model can be used to guide a combined qualitative and quantitative content analysis of responses to open-ended interviews questions. responses can be categorized as adaptive or ineffective within the physiological, self-concept, role function, and interdependence modes of adaptation and then tallied to yield an adaptation score.
Bloqueio atrioventricular de alto grau induzido pela cirurgia cardíaca: estudo de critérios de reversibilidade
NASCIMENTO Celso Soares,VIOTTI JúNIOR Luiz Amaury,SILVA Luiz Henrique Fernandes da,ARAúJO Adriana Maria de
Revista Brasileira de Cirurgia Cardiovascular , 1997,
Abstract: O bloqueio atrioventricular de alto grau (BAVG) pode se manifestar, em pequena incidência (2,1%), no pós-operatório de cirurgia cardíaca e ter caráter temporário ou permanente. Na ausência de critérios de reversibilidade, o tempo de permanência superior a 15 dias é indicativo de marcapasso cardíaco permanente (MPCP). Casos isolados poder o reverter após este período. Num estudo de 4 casos de bloqueio em 300 interven es cardíacas, os autores confirmam que a freqüência cardíaca e a compara o das características do QRS nos períodos antes, durante e após o bloqueio n o constituem critérios de reversibilidade; o eletrograma do feixe de His é dispensável na ado o da conduta; o período de 15 dias é adequado para a indica o do MPCP e o tempo corrigido de recupera o do marcapasso é indicativo de atividade juncional ou idioventricular incerta e deve ser estudado como critério de reversibilidade.
An Effective Extension of the Wagner Hierarchy to Blind Counter Automata  [PDF]
Olivier Finkel
Mathematics , 2010,
Abstract: The extension of the Wagner hierarchy to blind counter automata accepting infinite words with a Muller acceptance condition is effective. We determine precisely this hierarchy.
Antonín Dvo ák and Richard Wagner
Gabrijelova Jarmila
Muzikologija , 2006, DOI: 10.2298/muz0606305g
Abstract: The essay deals with the relation of prominent Czech composer Antonín Dvo ák (1841–1904) to the personality and work of Richard Wagner (1813–1883). As opposed to the common opinions linking Dvo ák’s name with Wagner‘s ideological opponents and placing his ‘Wagnerian’ period in the early phase of his career only, our examination shows that Dvo ák’s interest in Wagner and his music was of deep and lasting nature and was significant for him throughout the whole of his life.
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