Novel manually made NSM FRP (MMFRP) bars for shear strengthening of RC beams

This paper presents an experimental study evaluating the effectiveness of the Near Surface Mounted (NSM) technique with innovative manually made FRP bars (MMFRP) for shear strengthening of RC beams. RC beams designed to fail in shear were tested in three-point bending. To delay the onset of MMFRP bar debonding, a new anchorage is also developed and tested. This paper reports the results of a series of tests on simply supported rectangular RC beams, strengthened in shear with MMFRP bar either with or without the proposed anchorage. The load-deflection responses of all test beams are plotted, in addition to selected strain results. Performance and the failure modes of the test beams are presented and discussed in this paper. The proposed MMFRP bars and end anchorage enhanced the shear capacity between 25 to 48% over the control specimen. Furthermore, the adoption of the proposed end anchorage of MMFRP bars significantly enhanced the ductility of the test specimens.

Mechanical behaviour of AISiC nano composites produced by Ball Milling and Spark Plasma Sintering

Neste trabalho foram produzidos nanocompósitos de AlSiC misturando alumínio puro com nano partículas de SiC com diâmetro de 45 – 55 nm, usando, de forma sequencial, a técnica da metalurgia do pó e a compactação por “ Spark Plasma Sintering”. O compósito obtido apresentava grãos com 100 nm de diâmetro, encontrandose as partículas de SiC localizadas, principalmente, nas fronteiras de grão. O nanocompósito sob a forma de provetes cilíndricos foi submetido a testes de compressão uniaxial e a testes de nanoindentação para analisar a influência das nanopartículas de SiC, da fração volúmica de ácido esteárico e do tempo de moagem, nas propriedades mecânicas do material. Para efeitos de comparação, utilizouse o comportamento mecânico do Al puro processado em condições similares e da liga de alumínio AA1050O. A tensão limite de elasticidade do nanocompósito com 1% Vol./Vol. de SiC é dez vezes superior à do AA1050. O refinamento de grão à escala nano constitui o principal mecanismo de aumento de resistência mecânica. Na realidade, o Al nanocristalino sem reforço de partículas de SiC, apresenta uma tensão limite de elasticidade sete vezes superior à da liga AA1050O. A adição de 0,5 % Vol./Vol. e de 1 % Vol./Vol. de SiC conduzem, respetivamente, ao aumento da tensão limite de elasticidade em 47 % e 50%. O aumento do tempo de moagem e a adição de ácido esteárico ao pó durante a moagem conduzem apenas a um pequeno aumento da tensão de escoamento. A dureza do material medida através de testes de nanoindentação confirmaram os dados anteriores. A estabilidade das microestruturas do alumínio puro e do nanocompósito AlSiC, foi testada através de recozimento de restauração realizado às temperaturas de 150 °C e 250 °C durante 2 horas. Aparentemente, o tratamento térmico não influenciou as propriedades mecânicas dos materiais, excepto do nanocompósito com 1 % Vol./Vol. de SiC restaurado à temperatura de 250 °C, para o qual se observou uma redução da tensão limite de elasticidade na ordem dos 13 %. No alumínio nanocristalino, a tensão de escoamento é controlada pelo efeito de HallPetch. As partículas de SiC, são segregadas pelas fronteiras do grão e não contribuem para o aumento de resistência mecânica segundo o mecanismo de Orowan. Alternativamente, as nanopartículas de SiC constituem um reforço das fronteiras do grão, impedindo o seu escorregamento e estabilizando a nanoestrutura. Deste modo, as propriedades mecânicas do alumínio nanocristalino e do nanocompósito de AlSiC poderão estar relacionadas com a facilidade ou dificuldade do escorregamento das fronteiras de grão, embora não seja apresentada prova explícita deste mecanismo à temperatura ambiente.

FRP Seismic Strengthening of Concrete Structures

This paper presents the experimental work carried out on a full scale concrete frame strengthened with Fibre Reinforced Polymer (FRP) composites. The frame was damaged, strengthened with FRP reinforcement and re-tested to assess the effectiveness of the strengthening technique. The natural frequencies of vibration, displacements, velocities and accelerations for both the unstrengthened and strengthened frame were recorded and compared.

Strengthening PACs in small Parliaments: perspectives from the Caribbean

Recent efforts to strengthen the oversight capacity of the Parliaments of Jamaica and Trinidad and Tobago have paid particular attention to the public accounts committee (PAC). This chapter provides an analysis of the PACs in both countries. The committees have some similar features in terms of mandate and composition, but both have struggled to be effective, partly because of the difficulties in developing functioning committees in small jurisdictions and partly because of an unhelpful external context. Progress has been made in developing the internal environment of the PACs, but producing and demonstrating significant outputs and outcomes remain a major challenge.

Creating Shared Value in India: How Indian Corporations Are Contributing to Inclusive Growth While. Strengthening Their Competitive Advantage

Competitividad y valor compartido

A research capacity strengthening project for infectious diseases in Honduras: experience and lessons learned

Background: In Honduras, research capacity strengthening (RCS) has not received sufficient attention, but an increase in research competencies would enable local scientists to advance knowledge and contribute to national priorities, including the Millennium Development Goals (MDGs). Objective: This project aimed at strengthening research capacity in infectious diseases in Honduras, focusing on the School of Microbiology of the National Autonomous University of Honduras (UNAH). The primary objective was the creation of a research-based graduate program for the continued training of researchers. Parallel objectives included institutional strengthening and the facilitation of partnerships and networks. Methods: Based on a multi-stakeholder consultation, an RCS workplan was designed and undertaken from 2007 to 2012. Due to unexpected adverse circumstances, the first 2 years were heavily dedicated to implementing the project's flagship, an MSc program in infectious and zoonotic diseases (MEIZ). In addition, infrastructure improvements and demand-driven continuing education opportunities were facilitated; biosafety and research ethics knowledge and practices were enhanced, and networks fostering collaborative work were created or expanded. Results: The project coincided with the peak of UNAH's radical administrative reform and an unprecedented constitutional crisis. Challenges notwithstanding, in September 2009, MEIZ admitted the first cohort of students, all of whom undertook MDG-related projects graduating successfully by 2012. Importantly, MEIZ has been helpful in expanding the School of Microbiology's traditional etiology-based, disciplinary model to infectious disease teaching and research. By fulfilling its objectives, the project contributed to a stronger research culture upholding safety and ethical values at the university. Conclusions: The resources and strategic vision afforded by the project enhanced UNAH's overall research capacity and its potential contribution to the MDGs. Furthermore, increased research activity and the ensuing improvement in performance indicators at the prime Honduran research institution invoke the need for a national research system in Honduras.