963 research outputs found
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Report on a visit to Bangladesh to study socio-economic aspects of estuarine set bag net fisheries for BOBP Fisheries Programme
Abstract not availabl
Recommended from our members
Mission to Shri Lanka and India to review progress and plan future inputs into BOBP post-harvest fisheries activities
Research into the bicycle and motor-cycle traders of St John's market is largely complete. The cycle traders have decided to form the "Retail Fish Traders Society of Shri Lanka'' in association with the "Association of Shri Lankan Fisheries Cooperatives". The programme should now concentrate on developing a strategy for wider dissemination of the insulated fish storage box and improving methodologies for understanding informal fish marketing systems. A number of recommendations are offered to achieve these objectives. Potential post-harvest activities in Andra Pradesh were reviewed. Production of Maldive fish for the Indian markets looks promising and a strategy for implementation is recommended. Efforts to assist other fish marketing activities in the region (ie, cycle traders, head-loaders and beach seiners) should proceed with caution. Clarity of objective setting and careful targeting of interventions is essential among this fragile community
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Report on a mission to Romania to investigate production, processing and marketing of fresh water fish
Abstract not availabl
A holistic inverse approach based on a multi-objective function optimisation model to recover elastic-plastic properties of materials from the depth-sensing indentation test
Recent years have seen an increased interest in the mechanical characterisation of materials via the inverse analysis of depth-sensing indentation data; however, at low-loads both the reaction forces measured by the instrument and the contact evolution at the indenter-material interface may be severely affected by indentation size effects (ISEs). Notwithstanding the knowledge of ISE, the inverse analyses proposed to date have failed to investigate the divergence between the small-scale properties measured via indentation and the large-scale properties extracted from other techniques, e.g. tensile testing. Therefore, this study investigates the sensitivity of an inverse analysis methodology to the indentation size in relation to the size of the microstructure. The proposed inverse analysis approach is based on a multi-objective function (MOF) optimisation model that finds the combination of material properties (Young's modulus, yield stress and strain-hardening exponent) that provides the best fit to both the experimental load-displacement (P-h) curve extracted from the indentation instrument and pile-up profile of the residual imprint measured with an atomic force microscope. Therefore, the piling-up/sinking-in effect, which is strongly linked to the plastic hardening behaviour of the indented material, is considered to address the non-uniqueness issue of the inverse analysis of indentation. A Berkovich indenter was used to measure the near surface properties of three different materials, including a titanium alloy (Ti-6Al-4 V), chromium-molybdenum-vanadium steel (CrMoV) and high purity copper (C110); materials have been selected to represent a wide range of ductile metallic materials so as to assess the generality of the MOF model
Debris development in fretting contacts: debris particles and debris beds
In this study, the formation and destruction of compacted beds of oxidized debris particles are investigated. Fretting tests of steel specimens were conducted, employing a cylinder-on-flat geometry with displacement amplitude being varied. The debris was examined, both in the form of the debris beds and in the form of loose debris; together, these were characterized to better understand the mechanisms of debris bed formation and development throughout the fretting process. XRD was employed to determine the phase makeup of the debris, with SEM imaging and particle size analysis employed to understand the evolution of the debris from nanoparticles into agglomerates and then into sintered bed structures
Religion, altruism, and helping strangers: a multilevel analysis of 126 countries
This article tests how religion relates to helping strangers, an important but rarely studied measure of social solidarity and informal social capital. It uses the Gallup World Poll, a survey with nationally representative samples of 179,961 respondents from 126 countries. It finds that religious people, members of minority religions, and people in religiously diverse countries were more likely to help a stranger. Individuals living in devout countries were more likely to help strangers even if they themselves were not religious. The results suggest that religion plays a particularly important role in promoting the prosocial norms and values that motivate helping strangers
A sensitivity study of parameters affecting residual stress predictions in finite element modelling of the inertia friction welding process
This study presents a finite element (FE) model capable of predicting the final residual stress field in an inertia friction welded component of a CrMoV steel considering the elastic and inelastic components of strain resulting from mechanical deformation, temperature changes in the material and volumetric changes associated with phase transformations. The material database was improved to include the properties of the child phases involved in the polymorphic transformation during inertia friction welding (IFW) of CrMoV steels, i.e. austenite and quenched martensite, taking different approaches based on existent experimental data from the parent phase (tempered martensite) and material characterisation of the heat affected zone (HAZ) in weld trials. This is the only FE model available in the literature that takes into consideration the effects induced by the transformation strain component of multiple phases in the total strain generated during IFW. Several simulations were run using this FE model in order to address for the first time the sensitivity of the final residual stress field to the individual effects of the microstructural changes, the interrelationship of multiple phases, and to different processing parameters such as the die geometry, clamping history and cooling rates
Evolution of cosmic string configurations
We extend and develop our previous work on the evolution of a network of
cosmic strings. The new treatment is based on an analysis of the probability
distribution of the end-to-end distance of a randomly chosen segment of
left-moving string of given length. The description involves three distinct
length scales: , related to the overall string density, , the
persistence length along the string, and , describing the small-scale
structure, which is an important feature of the numerical simulations that have
been done of this problem. An evolution equation is derived describing how the
distribution develops in time due to the combined effects of the universal
expansion, of intercommuting and loop formation, and of gravitational
radiation. With plausible assumptions about the unknown parameters in the
model, we confirm the conclusions of our previous study, that if gravitational
radiation and small-scale structure effects are neglected, the two dominant
length scales both scale in proportion to the horizon size. When the extra
effects are included, we find that while and grow,
initially does not. Eventually, however, it does appear to scale, at a much
lower level, due to the effects of gravitational back-reaction.Comment: 61 pages, requires RevTex v3.0, SUSSEX-TH-93/3-4,
IMPERIAL/TP/92-93/4
Numerical and Experimental Analysis of the Deformation Behavior of CoCrFeNiMn High Entropy Alloy Particles onto Various Substrates During Cold Spraying
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