Transient radiative heat transfer within a suspension of coal particles undergoing steam gasification

Transient radiative heat transfer in chemical reacting media is examined for a non-isothermal, non-gray, absorbing, emitting, and Mie-scattering suspension of coal particles, whose radiative properties vary with time as the particles undergo shrinking by endothermic gasification. A numerical model that incorporates parallel filtered collision-based Monte Carlo ray tracing, finite volume method, and explicit Euler time integration scheme is formulated for solving the unsteady energy equation that couples the radiative heat flux with the chemical kinetics. Variation of radiative properties, attenuation characteristics, temperature profiles, and extent of the chemical reaction are reported as a function of time. It is found that radiation in the visible and near IR spectrum incident on a cloud of coal particles greater than 2.5μm is more likely to be forward scattered than absorbed, but the opposite is true as the particles shrink below 1.3μm. The medium becomes optically thinner as the particles shrink and this effect is more pronounced for smaller initial coal particles because these offer higher volume fraction to particle diameter ratio and, consequently, attain higher temperatures, reaction rates, and shrinking rate

Livestock to 2020: the next food revolution

A team of researchers from the International Food Policy Research Institute (IFPRI), the Food and Agricultural Organization of the United Nations (FAO), and the International Livestock Research Institute (ILRI) collaborated to produce this comprehensive and even-handed attempt at defining the nature, extent, scope, and implications of what they term the "Livestock Revolution” in developing countries. Looking forward to 2020, they argue convincingly that the structural shifts in world agriculture being brought about by shifts in developing-country demand for foods of animal origin will continue and that increasingly global markets have the ability to supply both cereal and animal products in desired quantities without undue price rises. They emphasize, however, that policy decisions taken for the livestock sector of developing countries will determine whether the Livestock Revolution helps or harms the world's poor and malnourished. The report emphasizes the importance of continued investment in both research on and development of animal and feed grain production and processing, and the need for policy action to help small, poor livestock producers become better integrated with commercial livestock marketing and processing. It details a host of requirements in the area of technology development for production and processing of livestock products, potential benefits from new technologies, and critical policy issues for environmental conservation and protection of public health.Environmental protection., Public health, Livestock., Markets., Animal products, Developing countries,

EMI Analysis Methods for Synchronous Buck Converter EMI Root Cause Analysis

DC/DC synchronous buck converters cause broadband emissions. A variety of methods are applied to analyze the root cause of the EMI. Time-domain voltage measurement and joint-time-frequency analysis allows to determine the location of the noise source. The near field scan reveals the current paths, and impedance measurement and 3D modeling can be used for further analysis of the noise source. A dual port TEM cell allows to distinguish E from H field coupling, This paper shows the application of those methods to a synchronous buck converter and reveals the sources of EMI leading to advice on the optimal PCB design. Finally, an innovative method of using a TEM cell measurement to predict the maximum possible radiated emissions is introduced

Livestock to 2020: The next food revolution

A team of researchers from the International Food Policy Research Institute (IFPRI), the Food and Agricultural Organization of the United Nations (FAO), and the International Livestock Research Institute (ILRI) collaborated to produce this comprehensive and even-handed attempt at defining the nature, extent scope, and implications of what they term the "Livestock Revolution" in developing countries. Looking forward to 2020, they argue convincingly that the structural shifts in world agriculture being brought about by shifts in developing country demand for foods of animal origin will continue and that increasingly global markets have the ability to supply both cereal and animal products in desired quantities without undue price rises. Topics of discussion include livestock revolution, recent transformation of livestock food demand; accompanying transformation of livestock supply; projections of future demand and supply to 2020; implications of the livestock revolution for world trade and food prices; nutrition, food security, and poverty alleviation; environmental sustainability; public health, technology needs and prospects; and taking stock and moving forward

Guidelines for initiation of anti-tumour necrosis factor therapy in rheumatoid arthritis: similarities and differences across Europe.

Contains fulltext : 80544.pdf (publisher's version ) (Closed access

Anti-microbial Use in Animals: How to Assess the Trade-offs

Antimicrobials are widely used in preventive and curative medicine in animals. Benefits from curative use are clear – it allows sick animals to be healthy with a gain in human welfare. The case for preventive use of antimicrobials is less clear cut with debates on the value of antimicrobials as growth promoters in the intensive livestock industries. The possible benefits from the use of antimicrobials need to be balanced against their cost and the increased risk of emergence of resistance due to their use in animals. The study examines the importance of animals in society and how the role and management of animals is changing including the use of antimicrobials. It proposes an economic framework to assess the trade-offs of anti-microbial use and examines the current level of data collection and analysis of these trade-offs. An exploratory review identifies a number of weaknesses. Rarely are we consistent in the frameworks applied to the economic assessment anti-microbial use in animals, which may well be due to gaps in data or the prejudices of the analysts. There is a need for more careful data collection that would allow information on (i) which species and production systems antimicrobials are used in, (ii) what active substance of antimicrobials and the application method and (iii) what dosage rates. The species need to include companion animals as well as the farmed animals as it is still not known how important direct versus indirect spread of resistance to humans is. In addition, research is needed on pricing antimicrobials used in animals to ensure that prices reflect production and marketing costs, the fixed costs of anti-microbial development and the externalities of resistance emergence. Overall, much work is needed to provide greater guidance to policy, and such work should be informed by rigorous data collection and analysis systems

The growing place of livestock products in world food in the twenty-first century

This paper attempts to define the nature, extent, scope, and implications of what the authors term the “Livestock Revolution” in developing countries. Looking forward to 2020, they argue that the structural shifts in world agriculture being brought about by shifts in developing-country demand for foods of animal origin will continue and that increasingly global markets have the ability to supply both cereal and animal products in desired quantities with out undue price rises. They emphasize, however, that policy decisions taken for the live stock sector of developing countries will determine whether the Livestock Revolution helps or harms the world's poor and malnourished. (from Foreward by Per Pinstrup-Andersen)Livestock. ,Poor Developing countries. ,Malnutrition. ,Meat industry and trade. ,

Simulation results for a low energy nuclear recoil yields measurement in liquid xenon using the MiX detector

Measuring the scintillation and ionization yields of liquid xenon in response to ultra-low energy nuclear recoil events is necessary to increase the sensitivity of liquid xenon experiments to light dark matter. Neutron capture on xenon can be used to produce nuclear recoil events with energies below $0.3$ keV$_\text{NR}$ via the asymmetric emission of $\gamma$ rays during nuclear de-excitation. The feasibility of an ultra-low energy nuclear recoil measurement using neutron capture was investigated for the Michigan Xenon (MiX) detector, a small dual-phase xenon time projection chamber that is optimized for a high scintillation gain. Simulations of the MiX detector, a partial neutron moderator, and a pulsed neutron generator indicate that a population of neutron capture events can be isolated from neutron scattering events. Further, the rate of neutron captures in the MiX detector was optimized by varying the thickness of the partial neutron moderator, neutron pulse width, and neutron pulse frequency.Comment: 7 pages, 5 figures. LIDINE 2022 proceeding

Solar-driven alumina calcination for CO(2) mitigation and improved product quality

Accepted 10th May 2017We report on the first-of-a-kind experimental demonstration of the calcination of alumina with concentrated solar thermal (CST) radiation at radiative fluxes up to 2190 suns using a 5 kW novel solar transport reactor. Aluminium hydroxide was calcined at nominal reactor temperatures over the range 1160–1550 K to yield chemical conversions of up to 95.8% for nominal residence times of approximately 3 s. Solar energy conversion efficiencies of up to 20.4% were achieved. The mean pore diameter and specific surface area of the solar-generated alumina with the greatest chemical conversion were 5.8 nm and 132.7 m² g⁻¹, respectively, which are higher values than are typical for industrial alumina production. In addition, the product is dominated by the γ-phase, which is desirable for the downstream processing to aluminium. This suggests that CST can improve the quality of alumina over existing fossil fuel based processes though a combination of a high heating rate and avoided contamination by combustion products. Furthermore, the solar-driven process has the potential to avoid the discharge of combustion-derived CO₂ emissions for the calcination stage of the conventional Bayer process, which is typically 165 kg-CO₂ per tonne-alumina.Dominic Davis, Fabian Müller, Woei L. Saw, Aldo Steinfeld and Graham J. Natha