603 research outputs found
Manipulation of ultracold atomic mixtures using microwave techniques
We used microwave radiation to evaporatively cool a mixture of of 133Cs and
87Rb atoms in a magnetic trap. A mixture composed of an equal number (around
10^4) of Rb and Cs atoms in their doubly polarized states at ultracold
temperatures was prepared. We also used microwaves to selectively evaporate
atoms in different Zeeman states.Comment: 9 pages, 6 figure
Low-temperature gas from marine shales
Thermal cracking of kerogens and bitumens is widely accepted as the major source of natural gas (thermal gas). Decomposition is believed to occur at high temperatures, between 100 and 200°C in the subsurface and generally above 300°C in the laboratory. Although there are examples of gas deposits possibly generated at lower temperatures, and reports of gas generation over long periods of time at 100°C, robust gas generation below 100°C under ordinary laboratory conditions is unprecedented. Here we report gas generation under anoxic helium flow at temperatures 300° below thermal cracking temperatures. Gas is generated discontinuously, in distinct aperiodic episodes of near equal intensity. In one three-hour episode at 50°C, six percent of the hydrocarbons (kerogen & bitumen) in a Mississippian marine shale decomposed to gas (C1–C5). The same shale generated 72% less gas with helium flow containing 10 ppm O2 and the two gases were compositionally distinct. In sequential isothermal heating cycles (~1 hour), nearly five times more gas was generated at 50°C (57.4 μg C1–C5/g rock) than at 350°C by thermal cracking (12 μg C1–C5/g rock)
Natural gas at thermodynamic equilibrium Implications for the origin of natural gas
It is broadly accepted that so-called 'thermal' gas is the product of thermal cracking, 'primary' thermal gas from kerogen cracking, and 'secondary' thermal gas from oil cracking. Since thermal cracking of hydrocarbons does not generate products at equilibrium and thermal stress should not bring them to equilibrium over geologic time, we would not expect methane, ethane, and propane to be at equilibrium in subsurface deposits. Here we report compelling evidence of natural gas at thermodynamic equilibrium. Molecular compositions are constrained to equilibrium
Farm Household Production Efficiency in Southern Malawi: An Efficiency Decomposition Approach
The present study was set out to estimate production efficiency of tomato (Lycopersicon esculentum L) farmers in the southern region of Malawi’s through efficiency decomposition. A random sample of 72 small-scale farmers was drawn from Balaka district. The findings revealed that farmers in Balaka district have opportunity for productivity gains and cost saving. Mean technical, economic and allocated efficiency were found to be 0.70, 0.57 and 0.82, respectively. Factors like education and credit access augment technical efficiency while credit access, farmer group membership and gender (being male) augment economic and allocative efficiency. Policy thrust like linking small scale farmers to micro-finance institutions for credit access, intensifying family planning programs to reduce family sizes, organizing small scale farmers into groups (cooperatives) and integrating women into training and extension programs would increase production efficiency of small-scale tomato farming in southern Malawi. Keywords: Decomposition, Malawi, production efficiency, production frontier, tomat
Can the current state support mechanisms help the growth of renewable energies in wind markets?
The aim of this paper is to provide evidence on the effectiveness of the current state support mechanism incentive adopted by the Italian government in the wind market. In particular, this paper intends to investigate the effectiveness of the auction mechanism as an incentive tool for renewable sources as required by the transposition of Directive 2009/28/EC. In order to demonstrate the economic and financial feasibility of a typical wind-sector investment, we performed a scenario analysis (Monte Carlo simulation) determining a 52,500 Net Present Value (NPV) by varying the key underlying variables of the investment. The results show that with the mechanism currently in place the percentage of positive leveraged NPV is approximately equal to 70%. Despite the state contribution provided through the “Feed-in tariff” mechanism, the profitability of wind projects is not always successful, and this problem could be amplified by the slowness of the authorization procedures. The article offers prime reflections for scholars and policy makers who have long been committed to promoting sustainable development and important considerations on the introduction of further incentive models
Circular Economy Impact Analysis on Stock Performances: An Empirical Comparison with the Euro Stoxx 50® ESG Index
Environmental issues have a considerable impact in all economic sectors, also influencing financial markets. As a result, environmental, social, and governance (ESG) awareness is rising in the financial sector. In this perspective, the concept of circular economy (CE) assumes central relevance. The aim of our study is to investigate the relationship between CE strategies and market performance; to this end, we use ESG scores as a proxy for CE. Our initial assumption is that since CE is a component of the “E” factor—in that it can generate positive and measurable environmental impacts—then it can be associated with the ESG score. Therefore, we can methodologically overcome the lack of a specific score related to CE. We use a preselection model based on historical performance by verifying the percentages of the presence of stocks in the two selected indices, namely ESG Euro Stoxx 50® and Euro Stoxx 50-ESG. Overall, we find that ESG profiles have a positive impact on stock performance, although ESG scores do not express higher performance per se. Furthermore, our analysis shows that, to date, there is no evidence that CE initiatives can influence stock returns
Policy and Procedure: Clinical Management of Human Trafficking Patients and/or Those at Risk for Exploitation
The Ohio Attorney General’s Office in its fight against human trafficking has created a Human Trafficking Initiative. Part of this initiative is the development of publications to assist providers in the care of and/or recognition of trafficked patients, data collection, and/or standards of service. This healthcare policy template is both evidence based and survivor informed. It will help to assist providers in understanding the basic guidelines of clinical management for human trafficking patients and/or those at risk for exploitation. This resource in addition to others can be found on the Ohio Attorney General’s website and is available to download and adopt as a reference/template for the development of healthcare policy and procedures
Low-temperature gas from marine shales: wet gas to dry gas over experimental time
Marine shales exhibit unusual behavior at low temperatures under anoxic gas flow. They generate catalytic gas 300° below thermal cracking temperatures, discontinuously in aperiodic episodes, and lose these properties on exposure to trace amounts of oxygen. Here we report a surprising reversal in hydrocarbon generation. Heavy hydrocarbons are formed before light hydrocarbons resulting in wet gas at the onset of generation grading to dryer gas over time. The effect is moderate under gas flow and substantial in closed reactions. In sequential closed reactions at 100°C, gas from a Cretaceous Mowry shale progresses from predominately heavy hydrocarbons (66% C5, 2% C1) to predominantly light hydrocarbons (56% C1, 8% C5), the opposite of that expected from desorption of preexisting hydrocarbons. Differences in catalyst substrate composition explain these dynamics. Gas flow should carry heavier hydrocarbons to catalytic sites, in contrast to static conditions where catalytic sites are limited to in-place hydrocarbons. In-place hydrocarbons and their products should become lighter with conversion thus generating lighter hydrocarbon over time, consistent with our experimental results
Acid-Sensing Ion Channel 1a Is Involved in N-Methyl D-Aspartate Receptor-Dependent Long-Term Depression in the Hippocampus
Acid-sensing ion channels (ASICs), members of the degenerin/epithelial Na+ channel superfamily, are largely expressed in the mammalian nervous system. ASIC1a is highly permeable to Ca2+ and are involved in many physiological processes, including synaptic plasticity, learning, and memory. To clarify the role of ASIC1a in synaptic transmission and plasticity, we investigated N-methyl D-aspartate (NMDA) receptor-dependent long-term depression (LTD) in the CA1 region of the hippocampus. We found that: (1) ASIC1a mediates a component of ASIC1a excitatory postsynaptic currents (EPSCs); (2) ASIC1a plays a role in electrical LTD induced by LFS protocol both in P13-18 and P30-40 animals; (3) ASIC1a is involved in chemical LTD induced by brief bath application of NMDA both in P13-18 and P30-40 animals; and finally (4) a functional interaction between ASIC1a and NMDA receptors occurs during LTD. These findings suggest a new role for ASIC1a in specific forms of synaptic plasticity in the mouse hippocampus
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