11,410 research outputs found

    Analysis of information systems for hydropower operations

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    The operations of hydropower systems were analyzed with emphasis on water resource management, to determine how aerospace derived information system technologies can increase energy output. Better utilization of water resources was sought through improved reservoir inflow forecasting based on use of hydrometeorologic information systems with new or improved sensors, satellite data relay systems, and use of advanced scheduling techniques for water release. Specific mechanisms for increased energy output were determined, principally the use of more timely and accurate short term (0-7 days) inflow information to reduce spillage caused by unanticipated dynamic high inflow events. The hydrometeorologic models used in predicting inflows were examined to determine the sensitivity of inflow prediction accuracy to the many variables employed in the models, and the results used to establish information system requirements. Sensor and data handling system capabilities were reviewed and compared to the requirements, and an improved information system concept outlined

    Two-dimensional matrix algorithm using detrended fluctuation analysis to distinguish Burkitt and diffuse large B-cell lymphoma

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    Copyright © 2012 Rong-Guan Yeh et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.A detrended fluctuation analysis (DFA) method is applied to image analysis. The 2-dimensional (2D) DFA algorithms is proposed for recharacterizing images of lymph sections. Due to Burkitt lymphoma (BL) and diffuse large B-cell lymphoma (DLBCL), there is a significant different 5-year survival rates after multiagent chemotherapy. Therefore, distinguishing the difference between BL and DLBCL is very important. In this study, eighteen BL images were classified as group A, which have one to five cytogenetic changes. Ten BL images were classified as group B, which have more than five cytogenetic changes. Both groups A and B BLs are aggressive lymphomas, which grow very fast and require more intensive chemotherapy. Finally, ten DLBCL images were classified as group C. The short-term correlation exponent α1 values of DFA of groups A, B, and C were 0.370 ± 0.033, 0.382 ± 0.022, and 0.435 ± 0.053, respectively. It was found that α1 value of BL image was significantly lower (P < 0.05) than DLBCL. However, there is no difference between the groups A and B BLs. Hence, it can be concluded that α1 value based on DFA statistics concept can clearly distinguish BL and DLBCL image.National Science Council (NSC) of Taiwan the Center for Dynamical Biomarkers and Translational Medicine, National Central University, Taiwan (also sponsored by National Science Council)

    Dynamic Response of an Embedded Structure Generated By a SH-Wave

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    In this investigation, a mathematical hybrid model developed previously is employed to study soil-structure interaction of embedded structure. In the analysis, the near field including the embedded structure and its surrounding foundation soil is modelled with a conventional finite element mesh, and the far field is modelled as a semi-infinite medium with a hemi-spherical pit. The impedance functions at the nodes around the special element, which have been determined analytically, can represent the behavior of outgoing propagation of waves. A concept of superposition is proposed to analyze the response of an embedded structure excited by an incoming SH-wave. The governing equations of the whole system will be formulated by enforcing the compatibility and equilibrium conditions at the nodes of the finite mesh. Basing on these equations, the response of the embedded structure and its surrounding ground can be determined accordingly. Numerical results have been obtained, and correlations with available solutions using continuum approaches are studied. The effects of the embedment on the responses are also shown and discussed

    Scattering-free plasmonic optics with anisotropic metamaterials

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    We develop an approach to utilize anisotropic metamaterials to solve one of the fundamental problems of modern plasmonics -- parasitic scattering of surface waves into free-space modes, opening the road to truly two-dimensional plasmonic optics. We illustrate the developed formalism on examples of plasmonic refractor and plasmonic crystal, and discuss limitations of the developed technique and its possible applications for sensing and imaging structures, high-performance mode couplers, optical cloaking structures, and dynamically reconfigurable electro-plasmonic circuits

    Spatial homogeneity and doping dependence of quasiparticle tunneling spectra in cuprate superconductors

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    Scanning tunneling spectroscopy (STS) studies reveal long-range (similar to 100 nm) spatial homogeneity in optimally and underdoped superconducting YBa2Cu3O7-delta (YBCO) single crystals and thin films, and macroscopic spatial modulations in overdoped (Y0.7Ca0.3)BaCu3O7-delta (Ca-YBCO) epitaxial films. In contrast, STS on an optimally doped YBa2(Cu0.9934Zn0.0026Mg0.004)(3)O-6.9 single crystal exhibits strong spatial modulations and suppression of superconductivity over a microscopic scale near the Zn or Mg impurity sites, and the global pairing potential is also reduced relative to that of optimally doped YBCO, suggesting strong pair-breaking effects of the non-magnetic impurities. The spectral characteristics are consistent with d(x2-y2) pairing symmetry for the optimally and underdoped YBCO, and with (d(x2-y2) + s) for the overdoped Ca-YBCO. The doping-dependent pairing symmetry suggests interesting changes in the superconducting ground state, and is consistent with the presence of nodal quasiparticles for all doping levels. The maximum energy gap Delta (d) is non-monotonic with the doping level, while the (2 Delta (d)/k(B)T(c)) ratio increases with decreasing doping. The similarities and contrasts between the spectra of YBCO and of Bi2Sr2CaCu2O8+x are discussed

    Microalgae for municipal wastewater nutrient remediation: mechanisms, reactors and outlook for tertiary treatment

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    This review explores the use of microalgae for nutrient removal in municipal wastewater treatment, considering recent improvements in the understanding of removal mechanisms and developments of both suspended and non-suspended systems. Nutrient removal is associated to both direct and indirect uptake, with the former associated to the biomass concentration and growth environment (reactor). Importantly, direct uptake is influenced by the Nitrogen:Phosphorus content in both the cells and the surrounding wastewater, with opposite trends observed for N and P. Comparison of suspended and non-suspended systems revealed that whilst all were capable of achieving high levels of nutrient removal, only non-suspended immobilized systems could do so with reduced hydraulic retention times of less than 1 day. As microalgae are photosynthetic organisms, the metabolic processes associated with nutrient assimilation are driven by light. Optimization of light delivery remains a key area of development with examples of improved mixing in suspended systems and the use of pulsating lights to enhance light utilization and reduce costs. Recent data provide increased confidence in the use of microalgae for nutrient removal in municipal wastewater treatment, enabling effluent discharges below 1 mg L−1 to be met whilst generating added value in terms of bioproducts for energy production or nutrient recovery. Ultimately, the review suggests that future research should focus on non-suspended systems and the determination of the added value potential. In so doing, it is predicted that microalgae systems will be significant in the delivery of the circular economy
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