15,029 research outputs found

    Unconditional quantum cloning of coherent states with linear optics

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    A scheme for optimal Gaussian cloning of optical coherent states is proposed and experimentally demonstrated. Its optical realization is based entirely on simple linear optical elements and homodyne detection. The optimality of the presented scheme is only limited by detection inefficiencies. Experimentally we achieved a cloning fidelity of about 65%, which almost touches the optimal value of 2/3.Comment: Phys. Rev. Lett. Volume 94, Number 24, p. 24050

    Mollusca of the Illinois River, Arkansas

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    The Illinois River is in the Ozark region of northwestern Arkansas and eastern Oklahoma. A survey of the Illinois River in Arkansas produced nine species and one morphological subspecies of gastropods, three species of sphaeriid clams, and 23 species of unionid mussels. Museum records resulted in another two species and an ecophenotype of the Unionidae. This represents the first published survey of molluscan species from the Illinois River in Arkansas

    OPTIMAL SPATIAL ALLOCATION OF WASTE MANAGEMENT PRACTICES TO REDUCE PHOSPHORUS POLLUTION IN A WATERSHED

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    Phosphorus pollution from excessive litter application and municipal discharges causes eutorphication of lakes in the Eucha-Spavinaw watershed in eastern Oklahoma and western Arkansas. Consequent algae blooms impair the taste of drinking water supply drawn from the watershed and reduce the recreational values of the lakes. The paper shows how GIS data based biophysical modeling can be used to derive spatially optimal, least-cost allocation of agricultural management practices to be combined with optimal wastewater treatment activity from the point source in order to achieve socially optimal phosphorus load in the watershed. The optimal level of phosphorus load is determined by equating marginal abatement with marginal damage cost. Transportation activities in the model allow for transportation of litter within and out of the watershed. Results show uniform regulation of litter application is excessively costly relative to measures that encourage adoption of management practices that equate marginal abatement costs across pollution sources. The results also show that change in the land use patterns in a long-run and using alum based litter additives in short-run are economically efficient management options.Environmental Economics and Policy,

    Decision Support System for Evaluating Rural Water Supply Infrastructure Scenarios

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    This paper seeks to develop a methodology that will be useful for rural water districts in assessing the future of their water systems infrastructure. In particular, the use of free water simulation software and publicly available data on population, roads, and terrain present rural water systems with the opportunity to analyze their existing distribution system and forecast where problems are likely to occur. This methodology will allow various alternatives (such as consolidation with a neighboring system, or pipe upgrades) to be evaluated and the costs of implementing these alternatives to be explored. Finally, different avenues for funding the associated costs can be summarized and presented to the community, including the steps needed to apply for popular grant and loan programsRural Water, Infrastructure, Simulation, EPANET, Community/Rural/Urban Development, R53, R58,

    Entrepreneurship and SMEs through business incubators in the Arab world: case study of Jordan

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    Business incubators (BI) have proved to be effective tools for looking after Entrepreneurship and SMEs to tackling unemployment, diversifying economies and creating wealth in numerous developed countries. By providing timely help and support for new ventures, business incubators hold the potential to create and develop entrepreneurial talent at the micro level and foster an environment for entrepreneurship at the macro level. This research aimed to determine whether the economic conditions for business strategy in the Arab World are favourable to a programme of business incubation and to suggest directions on the best ways to implement more business incubation in the Arab countries. To meet this aim the study undertook a snowball approach and distributed a designed questionnaire to the incubation unites in Jordan. The findings of the research contribute to the literature of business support services, innovation and entrepreneurship development and will enhance the knowledge and skills within the incubation industry. The centre’s incubator programme is designed to accelerate the successful development of young entrepreneurs and their businesses

    Amenities and the labor earnings function

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    I was unable to copy/paste the abstract, but the paper argues that amenities exert an important effect on wage differentials over space. Indeed, we show that as much has half of the apparent effect of unionization on wages is actually compensation for less desirable climate in locations that are most unionized.amenities; climate; weather; wage compensation; return to unionization

    The superficial brachial artery : a case report

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    A superficial brachial artery is an anomalous branch of the brachial artery that runs superficial to the median nerve; it is usually associated with a deep brachial branch that runs deep to this nerve. A case is described of a superficial brachial artery. It is of the type where the artery terminates in the cubital fossa by division into radial and ulnar arteries. It is associated with a superficial ulnar artery, and a deep brachial artery that is continued into the forearm as the common interosseous artery, a rare occurrence. The clinical importance and the dangers of this vascular anomaly are discussed. In reparative surgery, an accurate knowledge of the relationship, course and particularly the possible variations of the brachial artery is of considerable importance.peer-reviewe

    A Complex Chemical Potential: Signature of Decay in a Bose-Einstein Condensate

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    We explore the zero-temperature statics of an atomic Bose-Einstein condensate in which a Feshbach resonance creates a coupling to a second condensate component of quasi-bound molecules. Using a variational procedure to find the equation of state, the appearance of this binding is manifest in a collapsing ground state, where only the molecular condensate is present up to some critical density. Further, an excited state is seen to reproduce the usual low-density atomic condensate behavior in this system, but the molecular component is found to produce an underlying decay, quantified by the imaginary part of the chemical potential. Most importantly, the unique decay rate dependencies on density (ρ3/2\sim \rho ^{3/2}) and on scattering length (a5/2\sim a^{5/2}) can be measured in experimental tests of this theory.Comment: 4 pages, 1 figur

    The Economics of Efficient Phosphorus Abatement in a Watershed

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    This study presents a method to determine efficient environmental targets at a watershed level. Efficient targets are devised by estimating abatement cost and cost of environmental damages and minimizing their sum. The method was applied to a case study of phosphorus pollution in a watershed in Oklahoma. Several cumulative scenarios with alternative abatement options were simulated and efficient targets were determined. As the number of abatement options at disposal to agricultural sources increased, their optimal abatement expanded relative to the abatement at the point source. Efficient targets were found to be dependent on the choice of policy that stimulates abatement.efficiency, environmental targets, phosphorus pollution, watershed, Resource /Energy Economics and Policy,
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