27,021 research outputs found
Modelagem de lajes na análise tridimensional de edifícios de alvenaria estrutural
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia CivilPara melhorar a análise de projetos em alvenaria estrutural, está sendo desenvolvido como parte de um projeto de pesquisa um modelo tridimensional baseado no Método dos Elementos Finitos e sendo implementado em um programa computacional de fácil utilização, denominado EDALV. Esta dissertação está inserida neste projeto de pesquisa e tem como objetivo estudar a modelagem de lajes dos edifícios de alvenaria estrutural. No estudo inicial modelou-se 78 casos com edifícios de 4 e 8 pavimentos, variando-se suas dimensões em planta, a espessura das lajes e as seções dos pilares-parede. Comparou-se o modelo usual de diafragma rígido com modelos de elementos finitos planos e de casca, verificando-se que em muitos edifícios a hipótese de diafragma rígido não apresenta uma boa solução. A partir deste estudo inicial escolheu-se elementos de estado plano de tensão para modelar as lajes, desprezando-se sua rigidez fora do plano. Foi utilizada a técnica de subestrutura, desenvolvendo-se um "superelemento" diafragma, que foi implementado no programa EDALV. Também foi elaborado nesta dissertação um programa pré-processador para a entrada de dados via janelas e geração de malhas, denominado WINEDALV. Dois exemplos foram analisados utilizando-se os superelementos diafragma através do programa EDALV. Os resultados foram verificados em comparação com resultados obtidos pelo programa SAP 2000
Erratum to: Effect of moderate red wine intake on cardiac prognosis after recent acute myocardial infarction of subjects with Type 2 diabetes mellitus (Diabetic Medicine, (2006), 23, 9, (974-981), 10.1111/j.1464-5491.2006.01886.x)
No full textIn an article by Marfella et al, the author name C. Saron is incorrect and should be listed as C. Sardu. Therefore the correct author list is: R. Marfella, F. Cacciapuoti, M. Siniscalchi, F. C. Sasso, F. Marchese, F. Cinone, E. Musacchio, M. A. Marfella, L. Ruggiero, G. Chiorazzo, D. Liberti, G. Chiorazzo, G. F. Nicoletti, C. Sardu, F. D'Andrea, C. Ammendola, M. Verza and L. Coppola.In an article by Marfella et al, the author name C. Saron is incorrect and should be listed as C. Sardu. Therefore the correct author list is: R. Marfella, F. Cacciapuoti, M. Siniscalchi, F. C. Sasso, F. Marchese, F. Cinone, E. Musacchio, M. A. Marfella, L. Ruggiero, G. Chiorazzo, D. Liberti, G. Chiorazzo, G. F. Nicoletti, C. Sardu, F. D'Andrea, C. Ammendola, M. Verza and L. Coppola
A 2 h periodic variation in the low-mass X-ray binary Ser X-1
No full textSpectroscopy of the low-mass X-ray binary Ser X-1 using the Gran Telescopio Canarias have revealed a ?2 h periodic variability that is present in the three strongest emission lines. We tentatively interpret this variability as due to orbital motion, making it the first indication of the orbital period of Ser X-1. Together with the fact that the emission lines are remarkably narrow, but still resolved, we show that a main-sequence K dwarf together with a canonical 1.4 M? neutron star gives a good description of the system. In this scenario, the most likely place for the emission lines to arise is the accretion disc, instead of a localized region in the binary (such as the irradiated surface or the stream-impact point), and their narrowness is due instead to the low inclination (?10°) of Ser X-1
Comparação entre métodos de análise estrutural para reservatórios retangulares de concreto armado
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia Civil.Atualmente o concreto armado é um dos materiais mais utilizados na execução de reservatórios para o armazenamento de água e outros líquidos. A grande incidência de manifestações patológicas nos reservatórios de concreto armado no Brasil, causadas principalmente pela falta de controle de fissuração e por impermeabilização inadequada, motivou o desenvolvimento deste trabalho. Este trabalho restringe-se a patologias em reservatórios de concreto armado causadas por falha de projeto estrutural. Apresenta-se inicialmente uma revisão dos métodos de cálculo convencionais e das recomendações de normas para o projeto estrutural de reservatórios de concreto armado. Para diversos exemplos estes métodos são comparados com o Método dos Elementos Finitos, tanto para análises bi como tri-dimensional, considerando-se os materiais elástico-lineares. Para reservatórios elevados esta comparação é feita em termos de momentos fletores, deslocamentos, e orientação das tensões principais nas paredes dos reservatórios. No caso de reservatórios apoiados sobre o solo, consideram-se apoios fixos ou elásticos, variando-se o coeficiente de mola de acordo com o tipo de solo. Realiza-se também um levantamento das manifestações patológicas em alguns reservatórios construídos no estado de Santa Catarina. Entre estes seleciona-se um reservatório retangular, apoiado no solo, que apresentava muitas fissuras e corrosão. O reservatório foi analisado pelo Método dos Elementos Finitos, modelando-se as paredes e lajes por elementos de casca e os pilares por elementos de pórtico espacial. O solo foi modelado por apoios fixos e também por molas elásticas, variando-se a rigidez da mola dentro de uma certa faixa. Comparam-se os resultados analíticos com os obtidos pelos métodos convencionais de cálculo, em que consideram-se as paredes e as lajes isoladas e o solo rígido. Ao final do trabalho são apresentadas algumas conclusões e recomendações com relação aos métodos de cálculo de reservatórios e sugestões para trabalhos futuros
Evidence for the decay B0→J/ψω and measurement of the relative branching fractions of meson decays to J/ψη and J/ψη′
No full textFirst evidence of the B 0 → J / ψ ω decay is found and the B s 0 → J / ψ η and B s 0 → J / ψ η ′ decays are studied using a dataset corresponding to an integrated luminosity of 1.0 fb -1 collected by the LHCb experiment in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV. The branching fractions of these decays are measured relative to that of the B 0 → J / ψ ρ 0 decay:frac(B (B 0 → J / ψ ω), B (B 0 → J / ψ ρ 0)) = 0.89 ± 0.19 (stat) - 0.13 + 0.07 (syst),frac(B (B s 0 → J / ψ η), B (B 0 → J / ψ ρ 0)) = 14.0 ± 1.2 (stat) - 1.5 + 1.1 (syst) - 1.0 + 1.1 (frac(f d, f s)),frac(B (B s 0 → J / ψ η ′), B (B 0 → J / ψ ρ 0)) = 12.7 ± 1.1 (stat) - 1.3 + 0.5 (syst) - 0.9 + 1.0 (frac(f d, f s)), where the last uncertainty is due to the knowledge of f d / f s, the ratio of b-quark hadronization factors that accounts for the different production rate of B 0 and B s 0 mesons. The ratio of the branching fractions of B s 0 → J / ψ η ′ and B s 0 → J / ψ η decays is measured to befrac(B (B s 0 → J / ψ η ′), B (B s 0 → J / ψ η)) = 0.90 ± 0.09 (stat) - 0.02 + 0.06 (syst)
1ST MEASUREMENT OF GAMMA(D(S)(+)-]MU+NU)/GAMMA(D(S)(+)-]PHI-PI+)
No full textComplete Author List:
ACOSTA D, ATHANAS M, MASEK G, PAAR H, BEAN A, GRONBERG J, KUTSCHKE R, MENARY S, MORRISON RJ, NAKANISHI S, NELSON HN, NELSON TK, RICHMAN JD, RYD A, TAJIMA H, SCHMIDT D, SPERKA D, WITHERELL MS, PROCARIO M, YANG S, BALEST R, CHO K, DAOUDI M, FORD WT, JOHNSON DR, LINGEL K, LOHNER M, RANKIN P, SMITH JG, ALEXANDER JP, BEBEK C, BERKELMAN K, BESSON D, BROWDER TE, CASSEL DG, CHO HA, COFFMAN DM, DRELL PS, EHRLICH R, GALIK RS, GARCIASCIVERES M, GEISER B, GITTELMAN B, GRAY SW, HARTILL DL, HELTSLEY BK, JONES CD, JONES SL, KANDASWAMY J, KATAYAMA N, KIM PC, KREINICK DL, LUDWIG GS, MASUI J, MEVISSEN J, MISTRY NB, NG CR, NORDBERG E, OGG M, PATTERSON JR, PETERSON D, RILEY D, SALMAN S, SAPPER M, WORDEN H, WURTHWEIN F, AVERY P, FREYBERGER A, RODRIGUEZ J, STEPHENS R, YELTON J, CINABRO D, HENDERSON S, KINOSHITA K, LIU T, SAULNIER M, SHEN F, WILSON R, YAMAMOTO H, ONG B, SELEN M, SADOFF AJ, AMMAR R, BALL S, BARINGER P, COPPAGE D, COPTY N, DAVIS R, HANCOCK N, KELLY M, KWAK N, LAM H, KUBOTA Y, LATTERY M, NELSON JK, PATTON S, PERTICONE D, POLING R, SAVINOV V, SCHRENK S, WANG R, ALAM MS, KIM IJ, NEMATI B, ONEILL JJ, SEVERINI H, SUN CR, ZOELLER MM, CRAWFORD G, DAUBENMIER CM, FULTON R, FUJINO D, GAN KK, HONSCHEID K, KAGAN H, KASS R, LEE J, MALCHOW R, MORROW F, SKOVPEN Y, SUNG M, WHITE C, WHITMORE J, WILSON P, BUTLER F, FU X, KALBFLEISCH G, LAMBRECHT M, ROSS WR, SKUBIC P, SNOW J, WANG PL, WOOD M, BORTOLETTO D, BROWN DN, FAST J, MCILWAIN RL, MIAO T, MILLER DH, MODESITT M, SCHAFFNER SF, SHIBATA EI, SHIPSEY IPJ, WANG PN, BATTLE M, ERNST J, KROHA H, ROBERTS S, SPARKS K, THORNDIKE EH, WANG CH, DOMINICK J, SANGHERA S, SHELKOV V, SKWARNICKI T, STROYNOWSKI R, VOLOBOUEV I, ZADOROZHNY P, ARTUSO M, HE D, GOLDBERG M, HORWITZ N, KENNETT R, MONETI GC, MUHEIM F, MUKHIN Y, PLAYFER S, ROZEN Y, STONE S, THULASIDAS M, VASSEUR G, ZHU G, BARTELT J, CSORNA SE, EGYED Z, JAIN V, SHELDON P, AKERIB DS, BARISH B, CHADHA M, CHAN S, COWEN DF, EIGEN G, MILLER JS, OGRADY C, URHEIM J, WEINSTEIN A
Altered amino acid metabolism in patients with cardiorenal syndrome type 2: Is it a problem for protein and exercise prescriptions?
No full textThe goal of this retrospective study was to document any alterations in plasma amino acids (AAs) in subjects with cardiorenal syndrome type 2 (CRS 2). We analyzed data from sixteen patients with CRS 2 and eight healthy subjects (control group, C), whose plasma arterial (A) and venous (V) AA concentrations had been measured. Compared to C, the group of CRS 2 patients showed significant reductions by more than 90% in A (p < 0.01) and V (p < 0.01) individual AAs, whereas negative A-V differences that indicated a net muscle AA release (muscle hypercatabolism) were found in 59% of CRS 2 patients (p < 0.03). No significant differences in plasma A and V AA concentrations nor in A-V differences were found between patients with mild kidney damage (N = 5; estimated glomerular filtration rate, eGFR ≥ 60 mL/min/1.73 m2 ) and patients with moderate-severe kidney damage (N = 11; eGFR < 60 mL/min/1.73 m2 ). Several plasma arterial AAs correlated with hemodynamic variables, but not with GFR. The study showed that patients with CRS 2 had very low concentrations of circulating AAs, independent of the degree of GFR damage
Gravitational collapse of massless scalar field in f(R) gravity
No full textWe study the spherically symmetric gravitational collapse of massless scalar matter field in asymptotic flat spacetime in the Starobinsky R-2 gravity, one specific model in the f(R) gravity. In the Einstein frame of f(R) gravity, an additional scalar field arises due to the conformal transformation. We find that in addition to the usual competition between gravitational energy and kinetic energy in the process of gravitational collapse, the new scalar field brought by the conformal transformation adds one more competing force in the dynamical system. The dynamical competition can be controlled by tuning the amplitudes of the initial perturbations of the new scalar field and the matter field. To understand the physical reasons behind these phenomena, we analyze the gravitational potential behavior and calculate the Ricci scalar at center with the change of initial amplitudes of perturbations. We find rich physics on the formation of black holes through gravitational collapse in f(R) gravity.NNSF of ChinaSCI(E)[email protected]; [email protected]; [email protected]
Singularity problem in the f(R) model with nonminimal coupling
No full textWe consider the nonminimal coupling between matter and the geometry in the f(R) theory. In the new theory which we established, a new scalar psi has been defined and we give it a certain stability condition. We intend to take a closer look at the dark energy oscillating behavior in the de Sitter universe and the matter era, from which we derive the oscillating frequency and the oscillating condition. More importantly, we present the condition of coupling form that the singularity can be solved. We discuss several specific coupling forms and find that logarithmic coupling with an oscillating period Delta T similar to Delta z in the matter era z > 4 can improve singularity in the early universe. The result of numerical calculation verifies our theoretic calculation about the oscillating frequency. Considering two toy models, we find the cosmic evolution in the coupling model is nearly the same as that in the normal f(R) theory when lna > 4. We also discuss the local tests of the nonminimal coupling f(R) model and show the constraint on the coupling form. DOI: 10.1103/PhysRevD.86.123526http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000312836000002&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Astronomy & AstrophysicsPhysics, Particles & FieldsSCI(E)6ARTICLE12null8
Parallel R&D Paths Revisited
No full textThis paper revisits the logic of pursuing parallel R&D paths when there is uncertainty as to which approaches will succeed technically and/or economically. Previous findings by Richard Nelson and the present author are reviewed. A further analysis then seeks to determine how sensitive optimal strategies are to parameter variations and the extent to which parallel and series strategies are integrated. It pays to support more approaches, the deeper the stream of benefits is and the lower is the probability of success with a single approach. Higher profits are obtained with combinations of parallel and series strategies, but the differences are small when the number of series trial periods is extended from two to larger numbers. A "dartboard experiment" shows that when uncertainty pertains mainly to outcome values and the distribution of values is skew-distributed, the optimal number of trials is inversely related to the cost per trial.
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