Effects of new openings on the in/plane behaviour of unreinforced brick masonry walls

Existing brick masonry buildings are frequently modified to satisfy nowadays living demands. Such modifications may include new windows or doors that connect two rooms and require openings to be cut from load bearing walls. In current design practice, these interventions are generally designed and verified for vertical load, but the structural behavior of these altered walls when submitted to in-plane loads (due to seismic actions) is not yet fully understood. Thus, design practice may be inaccurately estimated. The objective of this work is to evaluate, numerically and experimentally, the effects of introducing openings in masonry solidbrick walls subjected to in-plane loading. Three main parameters are considered for the numerical studies: i) walls dimensions, ii) opening type, iii) opening size. As expected, results show that walls with medium-large openings are the most vulnerable case-scenario. These numerical results have addressed the design of a representative wall tested at the University of Brescia. The preliminary results of this experimental program are included in this pape

Experimental and numerical assessment of masonry walls with new openings strengthened with steel frame

The creation of new openings in masonry walls is a frequent intervention executed in existing buildings of unreinforced masonry composed of clay bricks. These openings are widely seen at the street-level, where spaces are modified to create new windows or doors for new stores, garages or offices. Depending on their size and position, these interventions may cause significant decrease of the wall’s original in-plane strength and stiffness, thus, compromising the building seismic resistance. For example, when several garages are created, one after another, the risk of inducing the soft-story mechanism, when earthquake forces arrive, increases. Another example is when a door of significant size is introduced in an originally solid masonry wall, which was a key object to guarantee the box-like behavior of the structure. The opening would reduce the cross section of the remaining piers and spandrel, and thus, weaken the wall’s seismic strength. These changes in the original wall have consequences in the box-like behavior, as during earthquake events, the load demands on the remaining shear walls might be larger than their shear capacity. Therefore, strengthening techniques must restore as much as possible the loss of stiffness and strength. Besides, for masonry structures, the technique must be reversible and respect the compatibility between materials, particularly in the case of protected assets. In an attempt to complying with these requirements, engineering practitioner often introduce steel profiles forming a frame inside the opening. Steel is usually preferred because of its high level of reversibility and the stiffness and strength it can provide to masonry without substantially increasing the building self-weight. The design of this steel frame and the stiffness of the masonry wall with opening is based in the available analytical tools, i.e., the Timoshenko Beam Theory. From these calculations, the loss of stiffness when passing from a solid wall to a perforated wall is about 75% for cantilever boundary conditions and 55% for double-fixed. Thus, very stiff profiles for the steel frame are required. In theory, these profiles are capable of fully restoring the stiffness and resistance. The present work is dedicated to evaluate the effectiveness of this steel frame technique by means of experimental and numerical methods. The experimental program was designed to provide full assessment of the effects of introducing a new door opening in brick masonry walls, from the perforation process to the application of in-plane cyclic loads . A flexible steel frame was designed using numerical tools and consisted in four profiles welded together and tied to the surrounding masonry wall by means of dry-driven dowels. The numerical model was validated against the experimental results, and show that neither a very stiff steel frame nor a more flexible one is capable of restoring the original solid wall’s stiffness. However, both are capable of restoring the in-plane strength and ductility. This paper, also shows that using a very stiff profile might lead to a rather brittle response of the reinforced wall, as the masonry starts cracking before activating the frame. This would not happen with a more flexible profileItalian Ministry of Education, University, and Research (MIUR) for her Doctoral Scholarship is gratefully acknowledged. The Authors also thank the technicians A. del Barba, A. Botturi from laboratory Pietro Pis

Inclusive Education in Russia: Historical-Sociological Aspect

This research analyzes social-historic reasons of inclusive education and its essence and significance; its methodological basis along with its reasons and tasks are getting revealed; humanistic essence of inclusive education’s conceptions along with pedagogical principles with their implementation possibilities, are getting substantiated. Since inclusion in common understanding is an acknowledgement of diversity in educational environment, one of its aspects became the subject of analysis — which is joint studying process of healthy students and students with limited health abilities (herein referred to LHA). Humanistic criterion of education environment is ability to provide personal development and social integration for a child. First of all — this is a transition to genuine interaction and communication among all children with no differences. For this purpose, different forms of collective activities are used in conditions of barrier-free environment, thus, children could learn standards of social behavior and gain experience of its reproduction in the process of interaction. Thus, the purpose of inclusive education turns out to be education for everyone, and following new humanistic approaches signal the transition from teaching children with LHA in special facilities, to integrated education. Analysis of normative law documents in aspect of requirements which regulate organizing of inclusive education for children with limited health abilities in the system of general education of Russian Federation was conducted in this article. Basing on analysis of documents’ content, there was made a conclusion about sufficiency of normative law basis of inclusive education being integrated and implemented into the system of general education; it is also noted that there is unsolved question of researching enforcement practice quality in part of providing special conditions to get general education by children with limited health abilities under conditions of inclusion. The actuality of matter chosen is explained by necessity to search new conceptual solutions and strategies, helping to harmonize human relationships in general with adaptation of people with special education needs. Keywords: education, inclusion, judiciary system, students with limited health abilities (disabled students), inclusive education environmen

Stationary axisymmetric exteriors for perturbations of isolated bodies in general relativity, to second order

Perturbed stationary axisymmetric isolated bodies, e.g. stars, represented by a matter-filled interior and an asymptotically flat vacuum exterior joined at a surface where the Darmois matching conditions are satisfied, are considered. The initial state is assumed to be static. The perturbations of the matching conditions are derived and used as boundary conditions for the perturbed Ernst equations in the exterior region. The perturbations are calculated to second order. The boundary conditions are overdetermined: necessary and sufficient conditions for their compatibility are derived. The special case of perturbations of spherical bodies is given in detail.Comment: RevTeX; 32 pp. Accepted by Phys. Rev. D. Added references and extra comments in introductio

Algunos comentarios acerca de la enseñanza de la historia de Colombia

El presente artículo de ninguna manera pretende agotar el tema que se aborta. El objetivo fundamental es: mostrar que la enseñanza de la Historia de Colombia ha sido tratada en forma poco científica y que no se le ha dado la importancia que en realidad merece. Además, destacar la labor que desarrollan nuevos investigadores al presentar un nuevo enfoque de la enseñanza y de la investigación histérica

Migration, Remittances and Capital Accumulation: Evidence from Rural Mexico

This article studies the link between migration, remittances and asset accumulation for a panel of poor rural households in Mexico over the period 1997--2006. In a context of financial markets' imperfections, migration may act as a substitute for imperfect credit and insurance provision (through remittances from migrants) and, thus, exert a positive effect on investment. However, it may well be the case that remittances are channelled towards increasing consumption and leisure goods instead. Exploiting within family variation and an instrumental variable strategy, we show that migration indeed accelerates productive assets' accumulation. However, when we look at the effect of migration on non-productive assets (durable goods), we find a negative effect. Our results then suggest that poor rural families resort to migration as a way to mitigate constraints that prevent them from investing in productive assets

Manejo intraparto del registro estresante no reactivo: un estudio randomizado controlado de oximetría de pulso (<A HREF="#1">1</A>)

Objetivo: Evaluar si la adición de la oximetría de pulso a la evaluación fetal intraparto con cardiotocografía (CTG) y pH de cuero cabelludo, mejora la precisión del diagnóstico de la condición fetal, permitiendo una reducción segura del número de partos operatorios y de la necesidad de evaluación con pH de cuero cabelludo por sospecha de compromiso fetal. Métodos: Se realizó un estudio randomizado controlado en embarazadas de término en trabajo de parto activo y que tuvieran un monitoreo electrónico fetal sospechoso. Se randomizaron 146 pacientes: 73 embarazadas con CTG y pH de cuero cabelludo (grupo control) y 73 pacientes CTG, pH de cuero cabelludo y oximetría de pulso continua (grupo de estudio). Resultados: Hubo una reducción de más del 50% en el número de partos operatorios (25 vs 49; p <0,001) y de la necesidad de monitoreo del pH (32 vs 64; p <0,001) en el grupo de estudio vs grupo control. No hubo diferencias significativas en los resultados de morbilidad adversa materna y neonatal, ni tampoco en el número de acidosis metabólicas o necesidad de resucitación. Conclusión: La oximetría de pulso reduce en forma efectiva el número de partos operatorios y mediciones de pH de cuero cabelludo. El alto número de cesáreas por distocia en el grupo de estudio se debe principalmente a prueba de trabajo de parto fracasada, sin embargo, esto no afecta el número total de partos operatorios en este grup

High-resolution rotation curves of low surface brightness galaxies: Data

We present long slit Halpha observations of 50 low surface brightness galaxies. Of these, 36 are of sufficient quality to form rotation curves. These data provide a large increase in the number of low surface brightness galaxies for which accurate rotation curves are available. They also represent an order of magnitude improvement in spatial resolution over previous 21 cm studies (1" to 2" instead of 13" to 45"). The improved resolution and accuracy of the data extend and strengthen the scientific conclusions previously inferred from 21 cm data.Comment: Accepted for publication in the Astronomical Journal. Electronic versions of the data are available at http://www.astro.umd.edu/~ssm/data & http://www.atnf.csiro.au/~edeblok/dat

SISTEMA DE RECOMENDAÇÃO PARA CONTROLE DA DIABETES

Este trabalho apresenta o desenvolvimento de um sistema de informação com técnicas de mineração de dados para o controle diário da diabetes

SISTEMA DE RECOMENDAÇÃO PARA CONTROLE DA DIABETES

Este trabalho apresenta o desenvolvimento de um sistema de informa&ccedil;&atilde;o com t&eacute;cnicas de minera&ccedil;&atilde;o de dados para o controle di&aacute;rio da diabetes