Experimental study on creep and shrinkage of high-performance ultra-lightweight cement composite of 60 MPa

Creep and shrinkage behaviour of an ultra lightweight cement composite (ULCC) up to 450 days was evaluated in comparison with those of a normal weight aggregate concrete (NWAC) and a lightweight aggregate concrete (LWAC) with similar 28-day compressive strength. The ULCC is characterized by low density < 1500 kg/m3 and high compressive strength about 60 MPa. Autogenous shrinkage increased rapidly in the ULCC at early-age and almost 95% occurred prior to the start of creep test at 28 days. Hence, majority of shrinkage of the ULCC during creep test was drying shrinkage. Total shrinkage of the ULCC during the 450-day creep test was the lowest compared to the NWAC and LWAC. However, corresponding total creep in the ULCC was the highest with high proportion attributed to basic creep (≥ ~90%) and limited drying creep. The high creep of the ULCC is likely due to its low elastic modulus. Specific creep of the ULCC was similar to that of the NWAC, but more than 80% higher than the LWAC. Creep coefficient of the ULCC was about 47% lower than that of the NWAC but about 18% higher than that of the LWAC. Among five creep models evaluated which tend to over-estimate the creep coefficient of the ULCC, EC2 model gives acceptable prediction within +25% deviations. The EC2 model may be used as a first approximate for the creep of ULCC in the designs of steel-concrete composites or sandwich structures in the absence of other relevant creep data.

Thermal gap conductance at low contact pressures (<1 MPa): Effect of gold plating and plating thickness

Thermal contact conductance (TCC) measurements are made on bare and gold plated (<= 0.5 mu m) oxygen free high conductivity (OFHC) Cu and brass contacts in vacuum, nitrogen, and argon environments. It is observed that the TCC in gaseous environment is significantly higher than that in vacuum due to the enhanced thermal gap conductance. It is found that for a given contact load and gas pressure, the thermal gap conductance for bare OFHC Cu contacts is higher than that for gold plated contacts. It is due to the difference in the molecular weights of copper and gold, which influences the exchange of kinetic energy between the gas molecules and contact surfaces. Furthermore, the gap conductance is found to increase with increasing thickness of gold plating. Topography measurements and scanning electron microscopy (SEM) analysis of contact surfaces revealed that surfaces become smoother with increasing gold plating thickness, thus resulting in smaller gaps and consequently higher gap conductance. (C) 2010 Elsevier Ltd. All rights reserved.

The India MPA Workshop Proceedings. Social Dimensions of Marine Protected Areas Implementation in India: do Fishing Communities Benefit? 21-22 January 2009, IMAGE Auditorium, Chennai, India

In the current context of natural resource management, marine protected areas (MPAs) are being widely propagated as an important tool for the conservation of marine and fisheries resources. The International Collective in Support of Fishworkers (ICSF) recently undertook a series of studies on MPAs in India to highlight the various legal, institutional, policy and livelihoods issues that confront fishing and coastal communities. In order to discuss the findings of these case studies and to suggest proposals for livelihood-sensitive conservation and management of coastal and fisheries resources through participatory processes, ICSF organized a two-day workshop on ‘Social Dimensions of Marine Protected Area Implementation in India: Do Fishing Communities Benefit?’ at Chennai on 21-22 January 2009. This publication—the India MPA Workshop Proceedings—contains the prospectus of the workshop, a report of the proceedings and the consensus statement that was reached by organizations and individuals who particapated in the workshop. This publication will be useful for fishworkers, non-governmental organizations, policymakers, trade unions, researchers and others interested in natural resource management and coastal and fishing communities.

Regional study on social dimensions of MPA practice in Central America: cases studies from Costa Rica, Nicaragua, Honduras and Panama

This research focuses on the social dimensions of marine conservation, and makes an assessment of the experiences of coastal and fi shing communities with regard to the governance of MPAs in Central America, based on case studies from Honduras, Nicaragua, Costa Rica and Panama. It examines the national contexts of the above countries in relation to the governance of MPAs. Furthermore, it analyzes the social impacts of MPAs on coastal communities by gathering the experiences and the voices of the communities and institutions involved, and reflects on how to build bridges in the search for forms and models of conservation that respect human rights and which are able to successfully integrate into local development efforts without affecting cultural and/or social patterns. To this end, this monograph looks at nine case studies across the region: in Honduras, the Islas de la Bahia-Guanaja Marine National Park, the Cayos Cochinos Marine Archipelago Natural Monument, and the Cuero and Salado Wildlife Refuge; in Nicaragua, the Chacocente Wildlife Refuge; in Costa Rica, the Guanacaste Conservation Area, the Ballena Marine National Park and the Golfo Dulce Responsible Fishing Area; and, in Panama, the Nargana Protected Area, in the Comarca de la Biosfera Guna-Yala, the Bastimentos Island Marine National Park, and Bocas del Toro.

Getting it right: incorporating social aspects into MPA planning and implementation

This brochure summarizes a series of case studies done in nine countries—Brazil, India, Indonesia, Mexico, Senegal, South Africa, Spain,Tanzania and Thailand—on the role of communities in the planning and implementation of marine protected areas (MPAs). The studies demonstrate that communities can be powerful allies in efforts for conservation and management of coastal and marine resources. They also underline the need for systematic attention, capacity building, funding and other resources for effective implementation of Programme Element 2 on governance, participation, equity, and benefit sharing of the Programme of Work on Protected Areas (PoWPA) of the Convention on Biological Diversity (CBD).

Movimentos sociais como produtores de conhecimento: a Soberania Alimentar no Movimento de Pequenos Agricultores (MPA).

A presente tese adota uma perspectiva cognitiva e epistêmica para o estudo dos movimentos sociais, tendo como objeto de estudo a Soberania Alimentar no Movimento dos Pequenos Agricultores: MPA. Defendemos a ideia que, através de sua atuação prática e discursiva, os movimentos sociais estão travando uma luta que, além de política e cultural, é também cognitiva e epistêmica e que essa dinâmica social é geradora de novas formas de conhecimento, como a Soberania Alimentar. Neste trabalho, a Soberania Alimentar é entendida como um programa social de conhecimento que vem sendo desenvolvido pela rede transnacional de movimentos sociais Via Campesina e as suas organizações constituintes (dentre as quais o MPA), articulados com entidades parceiras em redes de solidariedade transnacionais e transculturais e em oposição aos seus adversários, em relação a distintos contextos e escalas de ação. Apoiados nessa ideia e na perspectiva adotada, pretendemos revelar aspectos da multidimensionalidade e da multiespacialidade da dinâmica constitutiva da Soberania Alimentar, a partir do estudo das correlações entre o local e o global, o particular e o geral e as dimensões prática e intelectual da produção de conhecimento por movimentos sociais.