13,395 research outputs found

    Dynamic nonlinear analyses for the 4-storey infilled R/C frame: study of a retrofitting solution

    Get PDF
    A research project on assessment and retrofitting of R/C frame structures is currently being developed under the research programme of the ICONS TMR-research network. This paper presents and discusses the preliminary experimental results from a 4-storey bare frame representative of the common practice of 40~50 years ago in most south European countries and devotes special attention to the study of a retrofitting solution based on bracing and rubber dissipaters, which intends to increase stiffness and damping reducing consequently the earthquake deformation demands.O estudo aqui apresentado concentra-se numa solução de reforço de um pórtico utilizando contraventamentos (k-bracing) com perfis de aço em conjunto com elementos elastoméricos de dissipação. Os resultados das análises não lineares da estrutura com e sem alvenaria e com reforço são apresentados e discutidos. Na segunda parte da comunicação apresentam-se os resultados experimentais já disponíveis e discute-se o problema da modelação recorrendo aos resultados experimentais e comparando os resultados obtidos com diferentes tipos de modelos

    Seismic analyses of a R/C building: study of a retrofitting solution

    Get PDF
    The preliminary experimental results from the tests on a 4-storey R/C frame structure are presented and discussed. The full-scale model is representative of the common practice of 40~50 years ago in most south European countries. Special attention is devoted to the study of a retrofitting solution based on bracing and rubber dissipaters, which intends to increase stiffness and damping reducing consequently the earthquake deformation demands

    Foster families: A systematic review of intention and retention factors

    Get PDF
    Background: Compared to residential care, family foster care is the preferable type of alternative care for neglected or abused children as it provides a familiar context that supports children’s developmental needs. New foster families are needed to care for these children. Objective: This systematic review aims to provide a critical analysis of the literature, identifying factors that explain the intention to become and to continue as a foster family. This review was performed following the PRISMA checklist and guidelines, through a search conducted in the following databases (no restrictions were made): PsycArticles, PsycInfo, Psychology and Behavioral Sciences Collection, Academic Search Complete, ERIC, Scopus, and Web of Science. Study eligibility: The review includes empirical quantitative and/or qualitative studies in English, Portuguese, and Spanish, with community and/or foster parents’ samples and explores the factors for becoming and/or retention of foster parents. Results: Forty-nine studies were included. The results revealed that the intention to become a foster parent is largely influenced by motivational factors, personal and family characteristics, individual values and beliefs, social context influences, and perceived familiarity with the child protection system. The retention of foster families is closely related to factors within the child protection system, personal or family characteristics, foster child characteristics, and placement challenges. The relationship with agencies and professional support stands out as the most important factors. Limitations and Implications: This review did not include studies focused on children with specific needs and characteristics, and future research should consider the particular challenges of fostering this group. Practice implications of these findings for the recruitment, selection, and retention of foster families will be discussed.info:eu-repo/semantics/acceptedVersio

    XX/XY Sex Chromosomes in the South American Dwarf Gecko (\u3cem\u3eGonatodes humeralis\u3c/em\u3e)

    Get PDF
    Sex-specific genetic markers identified using restriction site-associated DNA sequencing, or RADseq, permits the recognition of a species’ sex chromosome system in cases where standard cytogenetic methods fail. Thus, species with male-specific RAD markers have an XX/XY sex chromosome system (male heterogamety) while species with female-specific RAD markers have a ZZ/ZW sex chromosome (female heterogamety). Here, we use RADseq data from 5 male and 5 female South American dwarf geckos (Gonatodes humeralis) to identify an XX/XY sex chromosome system. This is the first confidently known sex chromosome system in a Gonatodes species. We used a low-coverage de novo G. humeralis genome assembly to design PCR primers to validate the male-specificity of a subset of the sex-specific RADseq markers and describe how even modest genome assemblies can facilitate the design of sex-specific PCR primers in species with diverse sex chromosome systems

    Schwinger's Method for the Massive Casimir Effect

    Full text link
    We apply to the massive scalar field a method recently proposed by Schwinger to calculate the Casimir effect. The method is applied with two different regularization schemes: the Schwinger original one by means of Poisson formula and another one by means of analytical continuation.Comment: plain TeX, 6 pages, DFTUZ-93-2

    Receptividade estigmatica em Eucalyptus dunnii.

    Get PDF
    Devido à sua importância para os estudos de biologia reprodutiva da espécie e visando oferecer subsídios para melhorar a eficiência da polinização controlada, estudou-se a receptividade do estigma de E. dunnii Maiden, em um banco clonal, com 8 anos de idade, no município de Colombo, PR. Seis ramos em diferentes posições da copa de dois clones foram amostrados para a seleção de 20 botões florais, no estágio adequado à emasculação. Seis polinizações foram feitas, com intervalo de dois dias entre elas, no período de 10 dias, utilizando-se uma mistura de pólen de 3 clones diferentes do mesmo banco. As avaliações foram feitas mensalmente, na forma de contagem de cápsulas (frutos), até 180 dias após a emasculação Após esse período, os frutos foram coletados e as sementes extraídas. A quantidade de sementes produzidas por cápsula e o número total de cápsulas resultante das polinizações controladas variam entre clones. Para a maximização da eficiência da polinização controlada de E. dunnii, recomenda-se que esta seja feita ao redor do sexto dia após a antese

    Programa de melhoramento de pínus na Embrapa Florestas.

    Get PDF
    bitstream/item/61074/1/Documento-233.pd
    corecore