3,135 research outputs found

    Economic Aspects of Renewable Energy from Agricultural Waste on the Southern Plains of Texas

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    Motivated to explore sustainability of renewable energy from bio-waste, this study attempted to discover the economic feasibility of effectively utilizing the existing agricultural waste to generate bio-energy, to complement local nucleus business by meeting specific market demands while assessing the reasonable risk associated with bio-energy production for an area with heavy concentration of agricultural production and serious water constraints. Since the problems to be addressed are all location specified critical points for bio-energy generation, GIS maps are used to identify the locations and the associated attainable volumes of agricultural waste. Meanwhile, reasonable variation and distribution of attainable cotton gin waste was identified by using a Monte Carlo Markov Chain simulation. Consequently, the constrained expected profit maximization model was specified to assess the optimal plant size, application of technologies and associated production outputs under multiple scenarios of market situations. Conclusions based on the study results include that the possibility of peaking power contact for bio-energy outputs is critical for taking advantage of larger scales of bio-energy production, reducing the production risk and enhancing the competitiveness of bio-energy products. Gasifying biomass is a feasible way to generate electricity for peak load needs while satisfying self consumption and incidental sale if necessary facilities connecting to the grid are available. Mobile pyrolysis plants have sufficient potential for profits all the way through effectively converting biomass to bio-oil, hence increasing the feasibility of a large-scale bio-energy facility and the capability to meet the needs of higher valued peaking power by utilizing an existing facility at local power plants in the study region. Also, the study results imply that production of bio-energy from agricultural waste has higher risks, and the variance of profits could be immense even though at a typical area with heavy concentrations of agricultural production. Technology improvement associated with reduced expenses for plant facilities or the increased converting efficiency would be the key components for dealing the risk and commercializing bio-energy products in long term.sustainability, bio-energy, agricultural waste, economic feasibility, risk, Agribusiness, Land Economics/Use,

    Small Cell Lung Carcinoma Metastatic to the Ovary: Reports of Two Cases

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    Heuristic algorithms for a vehicle routing problem with simultaneous delivery and pickup and time windows in home health care

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    International audienceThis paper addresses a vehicle scheduling problem encountered in home health care logistics. It concerns the delivery of drugs and medical devices from the home care company's pharmacy to patients' homes, delivery of special drugs from a hospital to patients, pickup of bio samples and unused drugs and medical devices from patients. The problem can be considered as a special vehicle routing problem with simultaneous delivery and pickup and time windows, with four types of demands: delivery from depot to patient, delivery from a hospital to patient, pickup from a patient to depot and pickup from a patient to a medical lab. Each patient is visited by one vehicle and each vehicle visits each node at most once. Patients are associated with time windows and vehicles with capacity. Two mixed-integer programming models are proposed. We then propose a Genetic Algorithm (GA) and a Tabu Search (TS) method. The GA is based on a permutation chromosome, a split procedure and local search. The TS is based on route assignment attributes of patients, an augmented cost function, route re-optimization, and attribute-based aspiration levels. These approaches are tested on test instances derived from existing VRPTW benchmarks

    Dynamics of cold pulses induced by super-sonic molecular beam injection in the EAST tokamak

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    Evolution of electron temperature, electron density and its fluctuation with high spatial and temporal resolutions are presented for the cold pulse propagation induced by super-sonic molecular beam injection (SMBI) in ohmic plasmas in the EAST tokamak. The non-local heat transport occurs for discharges with plasma current IpI_p=450 kA (q955.55q_{95}\sim5.55), and electron density ne0n_{e0} below a critical value of (1.35±0.25)×1019 m3(1.35\pm0.25)\times10^{19}~\mathrm{m^{-3}}. In contrary to the response of core electron temperature and electron density (roughly 10 ms after SMBI), the electron density fluctuation in the plasma core increases promptly after SMBI and reaches its maximum around 15 ms after SMBI. The electron density fluctuation in the plasma core begins to decrease before the core electron temperature reaches its maximum (roughly 30 ms). It was also observed that the turbulence perpendicular velocity close to the inversion point of the temperature perturbation changes sign after SMBI

    The role of edge-based and surface-based information in natural scene categorization: evidence from behavior and event-related potentials

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    A fundamental question in vision research is whether visual recognition is determined by edge-based information (e.g., edge, line, and conjunction) or surface-based information (e.g., color, brightness, and texture). To investigate this question, we manipulated the stimulus onset asynchrony (SOA) between the scene and the mask in a backward masking task of natural scene categorization. The behavioral results showed that correct classification was higher for line-drawings than for color photographs when the SOA was 13ms, but lower when the SOA was longer. The ERP results revealed that most latencies of early components were shorter for the line-drawings than for the color photographs, and the latencies gradually increased with the SOA for the color photographs but not for the line-drawings. The results provide new evidence that edge-based information is the primary determinant of natural scene categorization, receiving priority processing; by contrast, surface information takes longer to facilitate natural scene categorization

    Spectroscopic investigations of Np(V/VI) redox speciation in hyperalkaline TMA-(OH, Cl) solutions

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    The redox chemistry of Np(V/VI) was investigated in ∼0.6M tetramethylammonium hydroxide/chloride (TMA-(OH, Cl)) solutions with 9 ≤ −log [H+] ≤ 13.5. Redox conditions were defined by the absence or presence of ClO− as oxidizing agent (Na-salt, 5×10−3M and 5×10−2M). The high total Np concentration ([Np]tot ∼ 2×10−3M) led to the precipitation of solid phases in some of the samples. The carbonate concentration (as impurity of TMA-OH) was 2-3×10−3M. UV-vis/NIR spectra obtained from the supernatant in TMA-(OH, Cl) solutions and absence of ClO− showed clear Np(V) features, identified as NpO2+, NpO2CO3− and (NpO2)x(CO3)y(OH)zx−2y−z. No NIR features were observed within 800nm ≤ λ ≤ 1300nm for samples with ClO−. XANES edge energies and features of these samples confirmed the predominance of Np(V) in the absence of ClO− and Np(VI) in the presence of ClO−, by comparison to XANES reference spectra of Np(III/IV/V/VI) prepared within the present work by in-situ electrolysis. Asimilar Np redox distribution was observed for the solid phases based on XANES and EXAFS measurements. EXAFS spectra indicative of NpVO2OH(s) and NpVIO3· xH2O(s) were obtained for samples in absence and presence of ClO−, respectively. The formation of aNa-Np(VI) phase in 5×10−2M ClO− and −log [H+] ∼ 12 was also indicated from the EXAFS, chemical analysis and SEM-EDS. These results indicate that Np(VI) aqueous species and solid compounds prevail far below the oxidation border of water in alkaline solutions and also far below the EH border calculated with the current NEA data selection [1]. These observations are further supported by correlations of literature thermodynamic data for actinides (U, Np, Pu and Am), which predict the formation of NpO2(OH)3− and NpO2(OH)42− aqueous species with stability constants (log *βº1,3 and log *βº1,4) similar to those available for U(VI

    The cosmic ray test of MRPCs for the BESIII ETOF upgrade

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    In order to improve the particle identification capability of the Beijing Spectrometer III (BESIII),t is proposed to upgrade the current endcap time-of-flight (ETOF) detector with multi-gap resistive plate chamber (MRPC) technology. Aiming at extending ETOF overall time resolution better than 100ps, the whole system including MRPC detectors, new-designed Front End Electronics (FEE), CLOCK module, fast control boards and time to digital modules (TDIG), was built up and operated online 3 months under the cosmic ray. The main purposes of cosmic ray test are checking the detectors' construction quality, testing the joint operation of all instruments and guaranteeing the performance of the system. The results imply MRPC time resolution better than 100psps, efficiency is about 98%\% and the noise rate of strip is lower than 1Hz/Hz/(scm2scm^{2}) at normal threshold range, the details are discussed and analyzed specifically in this paper. The test indicates that the whole ETOF system would work well and satisfy the requirements of upgrade
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