1,819 research outputs found

    China's Pork Miracle?

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    EXECUTIVE SUMMARY Agriculture has helped fuel the “China miracle.” Since 1978, agricultural and food output has soared, Chinese agribusiness firms have become key players in domestic and international markets, and by all accounts, China has been highly successful in overcoming land and resource constraints to feed its population of 1.3 billion people. The country is celebrated for its successes in reducing poverty and hunger over the last 30 years, and more recently, for creating an agrifood system that makes eating “high on the hog” a possibility and reality for many Chinese people. Pork is at the heart of this miracle. A hallmark of the post-1978 agricultural development model is ramping up the production, sale, and consumption of meat. Processed and packaged meats are the fastest growing market segments, reflecting the increasing influence and operation of pork processors, and the more general trend towards processed foods that can be shipped, stored, and sold with a longer shelf-life in super- and hyper-markets. These trends are also reflected in the Shuanghui (now called the WH Group to take on a more international identity) buyout of Smithfield Foods, a move that will increase China’s pork supplies, strengthen Shuanghui’s brand within China as “safer” meat with higher consumer status because of its US origin, and further generate and shape consumer demand for industrial pork. The Shuanghui-Smithfield deal is a matter of political and economic interest, but also signals a much more basic insight: pork, and the systems and actors that produce it, are central in China’s agrifood system with increasingly global inter-linkages and implications. etc. ..

    EFFECTS OF MEDU AND COASTAL TOPOGRAPHY ON THE DAMAGE PATTERN DURING THE RECENT INDIAN OCEAN TSUNAMI ALONG THE COAST OF TAMILNADU

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    Effects of Medu (naturally elevated landmass very close to the seashore and elongated parallel to the coast) and coastal topography on the damage pattern during the deadliest Indian Ocean tsunami of December 26, 2004 is reported. The tsunami caused severe damage and claimed many victims in the coastal areas of eleven countries bordering the Indian Ocean. The damage survey revealed large variation in damage along the coastal region of Tamilnadu (India).The most severe damage was observed in the Nagapattinam district on the east coast and the west coast of Kanyakumari district. Decrease of damage from Nagapattinam to Kanchipuram district was observed. Intense damage again appeared to the north of Adyar River (from Srinivaspuri to Anna Samadhi Park). Almost, no damage was observed along the coast of Thanjavur, Puddukkotai and Ramnathpuram districts in Palk Strait, situated in the shadow zone of Sri Lanka.It was concluded that the width of continental shelf has played a major role in the pattern of tsunami damage. It was inferred that the width of the continental shelf and the interference of reflected waves from Sri Lanka and Maldives Islands with direct waves and receding waves was responsible for intense damage in Nagapattinam and Kanyakumari districts, respectively. During the damage survey authors also noted that there was almost no damage or much lesser damage to houses situated on or behind the Medu. Many people observed the first arrival. The largest tsunami amplitude occurred as the first arrival on the eastern coast and in the second arrival on the western coast

    Estimators based on sample quantiles using (h,phi)-entropy measures

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    A point estimation procedure based on the maximum entropy principle for (h, phi) entropies is proposed using sample quantiles. These estimators are efficient and asymptotically normal under standard regularity conditions. A test for goodness-of-fit is constructed, being the corresponding statistic asymptotically distributed chi-squared. These results generalize the results obtained in [1]

    Adiabatic quantum pump in the presence of external ac voltages

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    We investigate a quantum pump which in addition to its dynamic pump parameters is subject to oscillating external potentials applied to the contacts of the sample. Of interest is the rectification of the ac currents flowing through the mesoscopic scatterer and their interplay with the quantum pump effect. We calculate the adiabatic dc current arising under the simultaneous action of both the quantum pump effect and classical rectification. In addition to two known terms we find a third novel contribution which arises from the interference of the ac currents generated by the external potentials and the ac currents generated by the pump. The interference contribution renormalizes both the quantum pump effect and the ac rectification effect. Analysis of this interference effect requires a calculation of the Floquet scattering matrix beyond the adiabatic approximation based on the frozen scattering matrix alone. The results permit us to find the instantaneous current. In addition to the current generated by the oscillating potentials, and the ac current due to the variation of the charge of the frozen scatterer, there is a third contribution which represents the ac currents generated by an oscillating scatterer. We argue that the resulting pump effect can be viewed as a quantum rectification of the instantaneous ac currents generated by the oscillating scatterer. These instantaneous currents are an intrinsic property of a nonstationary scattering process.Comment: 11 pages, 1 figur

    Four-year assessment of ambient particulate matter and trace gases in the Delhi-NCR region of India

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    A key challenge in controlling Delhi’s air quality is a lack of clear understanding of the impacts of emissions from the surrounding National Capital Region (NCR). Our objectives are to understand the limitations of publicly available data, its utility to determine pollution sources across Delhi-NCR and establish seasonal profiles of chemically active trace gases. We obtained the spatiotemporal characteristics of daily-averaged particulate matter (PM10 and PM2.5) and trace gases (NOX, O3, SO2, and CO) within a network of 12 air quality monitoring stations located over 2000 km2 across Delhi-NCR from January 2014 to December 2017. The highest concentrations of pollutants, except O3, were found at Anand Vihar compared with lowest at Panchkula. A high homogeneity in PM2.5 was observed among Delhi sites as opposed to a high spatial divergence between Delhi and NCR sites. The bivariate polar plots and k-means clustering showed that PM2.5 and PM10 concentrations are dominated by local sources for all monitoring sites across Delhi-NCR. A consequence of the dominance of local source contributions to measured concentrations, except to one site remote from Delhi, is that it is not possible to evaluate the influence of regional pollution transport upon PM concentrations measured at sites within Delhi and the NCR from concentration measurements alone

    Quantum pumping: Coherent Rings versus Open Conductors

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    We examine adiabatic quantum pumping generated by an oscillating scatterer embedded in a one-dimensional ballistic ring and compare it with pumping caused by the same scatterer connected to external reservoirs. The pumped current for an open conductor, paradoxically, is non-zero even in the limit of vanishing transmission. In contrast, for the ring geometry the pumped current vanishes in the limit of vanishing transmission. We explain this paradoxical result and demonstrate that the physics underlying adiabatic pumping is the same in open and in closed systems.Comment: 4 pages, 2 figure
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