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Flux Changes (flux + change)
Selected AbstractsProposal and development of radial air-gap coreless generator suitable for small wind turbine used in urban areaELECTRICAL ENGINEERING IN JAPAN, Issue 1 2009Toshiyuki Takahashi Abstract Independent distributed power generation using small wind turbines is becoming more widespread as wind power generation increases. Installation of small wind turbines in densely populated urban areas is not only useful from the viewpoint of extracting wind power sources in weak-wind areas but also for making renewable energy easier to access when power supplies are closer to consumers. It is from this point of view that the authors proposed "urban wind power generation" using a collective system with a number of small vertical wind turbines, and have developed a suitable generator for low-speed vertical wind turbines such as a Savonius windmill. Based on a standard coreless generator, the proposed generator is designed to make the direction of the magnetic flux radial in order to install the magnets and coils on the outer end of the generator. The change of magnet composition and flux direction maximizes the speed of the flux change and output voltage within a limited space. With the above configuration, the power of the proposed generator is independent of the diameter. In this report, the authors describe and evaluate the fundamental performance of a prototype of the proposed generator. Based on the experiments, a maximum output power of 283 W was obtained. The obtained starting torque is small enough to begin rotation under weak wind conditions of no more than 1 m/s. Therefore, it is clear that the proposed "radial" coreless generator is suitable for self-starting and producing high power at low wind speed. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 167(1): 26, 34, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20695 [source] Application of the photon's intrinsic flux to the 1s-2p and 2p-3d excitonic transitions in nanostructuresANNALEN DER PHYSIK, Issue 12 2009Z. Saglam Abstract We have applied our two recent results [depending on its helicity photon carries a quantum flux of ± , 0 = ± hc/e and the quantized magnetic fluxes through the electronic orbits of the Dirac hydrogen atom are given by: , (n,l,mj) = (n-l-mj),0) ] to the 1s-2p and 2p-3d excitonic transitions in nanostructures. It is shown that the flux changes for the non-zero matrix elements in the 1s-2p and 2p-3d excitonic transitions is either ± ,0 or zero. The present result supports the previous results stated above. It is also shown that spin flip is possible in the 1s-2p and 2p-3d excitonic transitions. [source] V5116 Sgr: A disc-ecipsed SSS post-outburst nova?,ASTRONOMISCHE NACHRICHTEN, Issue 2 2010G. Sala Abstract Nova V5116 Sgr 2005 No. 2, discovered on 2005 July 4, was observed with XMM-Newton in March 2007, 20 months after the optical outburst. The X-ray spectrum showed that the nova had evolved to a pure supersoft X-ray source, indicative of residual H-burning on top of the white dwarf. The X-ray light-curve shows abrupt decreases and increases of the flux by a factor 8 with a periodicity of 2.97 h, consistent with the possible orbital period of the system. The EPIC spectra are well fit with an ONe white dwarf atmosphere model, with the same temperature both in the low and the high flux periods. This rules out an intrinsic variation of the X-ray source as the origin of the flux changes, and points to a possible partial eclipse as the origin of the variable light curve. The RGS high resolution spectra support this scenario showing a number of emission features in the low flux state, which either disappear or change into absorption features in the high flux state. A new XMM-Newton observation in March 2009 shows the SSS had turned off and V51 16 Sgr had evolved into a weaker and harder X-ray source (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] A single magnetic field exposure system for sequential investigation of real time and downstream cellular responsesBIOELECTROMAGNETICS, Issue 1 2004Raj R. Rao Abstract To be able to correlate real time membrane potential or ion flux changes with further downstream gene transcription responses due to extremely low frequency (ELF) electromagnetic field (EMF) exposure, we devised an experimental system consisting of a pair of symmetric circular coils. This system can be used on an inverted microscope stage (real time signaling) as well as inside controlled environment incubators (gene transcription end points). The system includes a unique, custom made switch box for blinding the experimental staff and a power amplifier. We report herein the design and characterization of the system with respect to parameters considered important in in vitro ELF,EMF exposure studies, including linear magnetic field distribution, compensation for microscope objective lens interference, heating effects of the coils, and harmonic content of the signals. Bioelectromagnetics 25:27,32, 2004. © 2003 Wiley-Liss, Inc. [source] Probing protein colloidal behavior in membrane-based separation processes using spectrofluorometric Rayleigh scattering dataBIOTECHNOLOGY PROGRESS, Issue 3 2010Rand Elshereef Abstract One of the primary problems in membrane-based protein separation is membrane fouling. In this study we explored the feasibility of employing Rayleigh light scattering data from fluorescence studies combined with chemometric techniques to determine whether a correlation could be established with membrane fouling phenomena. Membrane flux was measured in a dead-end UF filtration system and the effect of protein solution properties on the flux decline was systematically investigated. A variety of proteins were used as a test case in this study. In parallel, the colloidal behavior of the protein solutions was assessed by employing multiwavelength Rayleigh scattering measurements. To assess the usefulness of Rayleigh scattering measurements for probing the colloidal behavior of proteins, a protein solution of ,-lactoglobulin was used as a base-case scenario. The colloidal behavior of different ,-lactoglobulin solutions was inferred based on published data for this protein, under identical solution conditions, where techniques other than Rayleigh scattering had been used. Using this approach, good agreement was observed between scattering data and the colloidal behavior of this protein. To test the hypothesis that a high degree of aggregation will lead to increased membrane fouling, filtration data was used to find whether the Rayleigh scattering intensity correlated with permeate flux changes. It was found that for protein solutions which were stable and did not aggregate, fouling was reduced and these solutions exhibited reduced Rayleigh scattering. When the aggregation behavior of the solution was favored, significant flux declines occurred and were highly correlated with increased Rayleigh scattering. © 2010 American Institute of Chemical Engineers Biotechnol. Prog., 2010 [source] Multiobjective flux balancing using the NISE method for metabolic network analysisBIOTECHNOLOGY PROGRESS, Issue 4 2009Young-Gyun Oh Abstract Flux balance analysis (FBA) is well acknowledged as an analysis tool of metabolic networks in the framework of metabolic engineering. However, FBA has a limitation for solving a multiobjective optimization problem which considers multiple conflicting objectives. In this study, we propose a novel multiobjective flux balance analysis method, which adapts the noninferior set estimation (NISE) method (Solanki et al., 1993) for multiobjective linear programming (MOLP) problems. NISE method can generate an approximation of the Pareto curve for conflicting objectives without redundant iterations of single objective optimization. Furthermore, the flux distributions at each Pareto optimal solution can be obtained for understanding the internal flux changes in the metabolic network. The functionality of this approach is shown by applying it to a genome-scale in silico model of E. coli. Multiple objectives for the poly(3-hydroxybutyrate) [P(3HB)] production are considered simultaneously, and relationships among them are identified. The Pareto curve for maximizing succinic acid production vs. maximizing biomass production is used for the in silico analysis of various combinatorial knockout strains. This proposed method accelerates the strain improvement in the metabolic engineering by reducing computation time of obtaining the Pareto curve and analysis time of flux distribution at each Pareto optimal solution. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009 [source] | |||||||||||||