46,630 research outputs found
Study of the decay mechanism for B+ -> p(p)over-barK(+) and B+ -> p(p)over-bar pi(+)
No full textWe study the characteristics of the low mass p (p) over bar enhancements near threshold in the three-body decays B+ -> p (p) over barK(+) and B+ -> p (p) over bar pi(+). We observe that the proton polar angle distributions in the p (p) over bar helicity frame in the two decays have the opposite polarity, and measure the forward-backward asymmetries as a function of the p mass for the p (p) over barK(+) mode. We also search for the intermediate two-body decays, B+ -> (p) over bar Delta(++) and B+ -> p (Delta) over bar (0), and set upper limits on their branching fractions. These results are obtained from a 414 fb(-1) data sample that contains 449 x 10(6) B (B) over bar events collected near the Gamma(4S) resonance with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. (c) 2007 Elsevier B.V. All rights reserved.IPE
An elastic-plastic interface model for fracture of quasi brittle materials
No full textTECHICAL REPORT - Università degli Studi di Bresci
Cyclic Analyses of Reinforced Concrete Masonry Panels Using a Force-Based Frame Element
No full textThis paper presents the calibration of a frame element that can be used to model the flexural as well as the shear behavior of reinforced masonry panels subjected to monotonic and cyclic loads. The element can be used in the equivalent frame method to analyze masonry wall systems, and is based on a force-based Timoshenko beam element formulation that combines a fiber-section model with a phenomenological nonlinear shear law. The element was originally applied to the analysis of reinforced concrete frames, and has been recently extended to unreinforced masonry structures. Well-established constitutive laws are used for masonry and steel reinforcement. The constitutive law for shear requires special attention in order to correctly predict the shear force-deformation response of masonry walls, accounting for the presence of shear reinforcement. A procedure to calibrate the parameters of the shear law is presented. The effectiveness, accuracy, and simplicity of the force-based Timoshenko frame element and the calibration method are validated by results of experimental tests. Even though the element is general and can model any reinforced masonry panel, the applications of this paper focus on panels made of hollow concrete blocks
MODELLING IN-PLANE AND OUT-OF-PLANE RESPONSE OF INFILLED FRAMES THROUGH A FIBER MACRO-MODEL
No full textA new fiber macro-model for the simulation of combined in-plane and out-of plane response of infilled frames subjected to seismic actions is presented in the paper. The model consists of 4 pinned struts (two diagonals, one horizontal and one vertical) modeled with the nonlinear beam/column fiber-section elements available in OpenSees. The model is particularly suitable to predict the out-of-plane response as fiber-section elements can account for the coupling between axial load and bending moment occurring because of the arching mechanism developed by the infills beyond the first cracking. Moreover the model can account for the effect of the reciprocal damaging accumulated both in-plane and out-of-plane during shakings. The procedure for the identification of the struts is presented in the paper and is validated with experimental test data from different authors. The proposed model may be used as a computationally-light and effective tool for the assessment of the response of 3D structures subjected to ground motions acting in arbitrary directions
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
A REINFORCED CONCRETE MODEL FOR ANALYZING FLEXURAL AND SHEAR BEHAVIOR OF R/C BEAM-COLUMNS
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