50 research outputs found

    Parallel twin-body trawl for shrimps, its design and efficiency

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    Comparative studies with a new 17 m parallel twin-body trawl and a 17 m bulged belly trawl conducted off Cochin during 1974-77 are reported. The parallel twin body trawl showed an increase of 28% in catch over that of bulged belly with a break up of 39.9% and 23.1 % for prawns and fishes respectively. The increase in catch is attributed to the extra wide mouth opening (26.6 %) of the parallel twin-body trawl. Parallel twin-body trawl had 8.96% lesser resistance which resulted in lower utilization of horse power

    The American Way to the Kyoto Protocol: an Economic Analysis to Reduce Carbon Pollution. A Study for World Wildlife Fund

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    This report presents a study of policies and measures that could dramatically reduce US greenhouse gas emissions over the next two decades. It examines a broad set of national policies to increase energy efficiency, accelerate the adoption of renewable energy technologies, and shift energy use to less carbon-intensive fuels. The policies address major areas of energy use in residential and commercial buildings, industrial facilities, transportation, and power generation

    Tweed in Martensites: A Potential New Spin Glass

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    We've been studying the ``tweed'' precursors above the martensitic transition in shape--memory alloys. These characteristic cross--hatched modulations occur for hundreds of degrees above the first--order shape--changing transition. Our two--dimensional model for this transition, in the limit of infinite elastic anisotropy, can be mapped onto a spin--glass Hamiltonian in a random field. We suggest that the tweed precursors are a direct analogy of the spin--glass phase. The tweed is intermediate between the high--temperature cubic phase and the low--temperature martensitic phase in the same way as the spin--glass phase can be intermediate between ferromagnet and antiferromagnet.Comment: 18 pages and four figures (included

    Ethical choices behind quantifications of fair contributions under the Paris Agreement

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    The Parties to the UNFCCC and Paris Agreement agreed to act on the basis of equity to protect the climate system. Equitable effort sharing is an irreducibly normative matter, yet some influential studies have sought to create quantitative indicators of equitable effort that claim to be value-neutral (despite evident biases). Many of these studies fail to clarify the ethical principles underlying their indicators, some mislabel approaches that favour wealthy nations as ‘equity approaches’ and some combine contradictory indicators into composites we call derivative benchmarks. This Perspective reviews influential climate effort-sharing assessments and presents guidelines for developing and adjudicating policy-relevant (but not ethically neutral) equity research

    Hysteresis and hierarchies: dynamics of disorder-driven first-order phase transformations

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    We use the zero-temperature random-field Ising model to study hysteretic behavior at first-order phase transitions. Sweeping the external field through zero, the model exhibits hysteresis, the return-point memory effect, and avalanche fluctuations. There is a critical value of disorder at which a jump in the magnetization (corresponding to an infinite avalanche) first occurs. We study the universal behavior at this critical point using mean-field theory, and also present preliminary results of numerical simulations in three dimensions.Comment: 12 pages plus 2 appended figures, plain TeX, CU-MSC-747

    Three decades of climate mitigation: why haven't we bent the global emissions curve?

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    Despite three decades of political efforts and a wealth of research on the causes and catastrophic impacts of climate change, global carbon dioxide emissions have continued to rise and are 60% higher today than they were in 1990. Exploring this rise through nine thematic lenses—covering issues of climate governance, the fossil fuel industry, geopolitics, economics, mitigation modeling, energy systems, inequity, lifestyles, and social imaginaries—draws out multifaceted reasons for our collective failure to bend the global emissions curve. However, a common thread that emerges across the reviewed literature is the central role of power, manifest in many forms, from a dogmatic political-economic hegemony and influential vested interests to narrow techno-economic mindsets and ideologies of control. Synthesizing the various impediments to mitigation reveals how delivering on the commitments enshrined in the Paris Agreement now requires an urgent and unprecedented transformation away from today's carbon- and energy-intensive development paradigm
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