In this paper, we investigate rotor and stator designs of interior permanent synchronous motors for variable speed/load applications to reduce the carrier harmonic losses caused by pulsewidth ...modulated inverters. The rotor core and magnet shapes are determined by automatic optimization methods with electromagnetic field analysis, which considers the inverter carrier. Appropriate stator-winding configurations are also investigated by this analysis. It is clarified that the total carrier harmonic loss can be reduced by more than 20% by optimizing both the stator and rotor shapes, whereas the other important characteristics are not deteriorated. The mechanism of carrier loss reduction is also clarified.
An automatic shape optimization procedure that estimates the inverter carrier harmonic losses generated at cores and magnets has been developed in order to improve the performance of interior ...permanent magnet motors used for variable speed/load applications. In the proposed procedure, an electromagnetic field analysis coupled with armature voltage equation is iteratively carried out at each rotor shape. The input of this analysis is the theoretical inverter voltage, which is determined by both the rotor shape and the driving conditions of the motor. The proposed procedure is applied to a 100 kW-class interior permanent magnet motor, in which the carrier harmonic losses become dominant under frequent driving conditions. It is clarified that the carrier harmonic losses can be reduced by more than 10%, whereas the other important characteristics are not deteriorated.
In order to clarify the effect of metal cations (Zn2+, Mg2+, Na+) in aqueous solution on hydrogen absorption into iron, the amount of hydrogen absorption from iron surface was measured by ...electrochemical tests with a laser ablation. Moreover, in order to obtain the basic mechanism of hydrogen absorption with adsorption of metal cation, we obtained the adsorption potential of the adsorbed atom and the electronic state around the adsorbed atom using first principles calculations. Peak value of permeation current and the time until the current reached the peak value decreased and elongated in the order of NaCl, MgCl2, and ZnCl2 solutions. Also, by first-principles calculations adsorption strength of each metal atom increased in the order of Na < Mg < Zn. It was suggested that dissolution of Fe is inhibited due to formation of dense metal layer in the solution including the metal cation which has large adsorption strength to Fe surface like Zn, and finally permeation current may have been reduced.
Flying carp eggs Suetsugu, Kenji; Togashi, Yusuke
Frontiers in ecology and the environment,
February 2020, 2020-02-00, 20200201, Volume:
18, Issue:
1
Journal Article
Peer reviewed
Open access
A study about flying carp eggs is featured. The discovery of a carp egg stuck to the forewings of water scorpion, which leads to the hypothesis that fish eggs may be passively dispersed between ponds ...by water scorpions, which are known to frequently fly from one pond to another during the day. The observation also provides clues that may explain fish distribution patterns and fishes can often be found in ponds and lakes that lack connectivity with other surface waters, despite being unable to actively more between the isolated water bodies.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NMLJ, NUK, OILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK
Interferon alpha (IFN-α), patch preparations composed of three layers, water-insoluble backing layer, drug containing layer with absorption enhancer and surface layer containing pH-dependent polymer ...were prepared. As absorption enhancer, three surfactants, Gelucire44/14 (Lauroyl macrogol-32 glycerides), Labrasol (Caprylocaproyl macrogol-8 glycerides) and HCO-60 (polyoxyethylated hydrogenerated castor oil) were used in preparing IFN-α patch preparations. The intestinal absorption of IFN-α was studied after the administration of test patch preparations into the rat jejunum, 50,000 IU/kg. The serum IFN-α levels were measured by an ELISA method and both C
max and AUC were determined as the index of absorption of IFN-α. Gelucire44/14 preparation including Pharmasol for the stable solidification showed the higher C
max, 7.66 ± 0.82 IU/ml, and AUC, 12.85 ± 1.49 IU h/ml, than Labrasol (6.51 ± 0.89 and 8.30 ± 1.34 IU h/ml) and HCO-60 (6.02 ± 1.14, 7.53 ± 1.84 IU h/ml) preparations, respectively. By comparing to the AUC obtained after s.c. injection of the same dose of IFN-α to rats, bioavailability (BA) was estimated to be 7.8% in Gelucire44/14 preparation. In vitro release study showed that the T50%s, the time when half of the formulated IFN-α is released from the patches, were 3.4 ± 0.1 min for HCO-60, 7.8 ± 0.1 min for Gelucire44/14 and 11.4 ± 0.1 min for Labrasol preparations. To study the effect of absorption site, Gelucire44/14 preparation was administered into the rat duodenum and ileum. However, there were not significant differences on AUC among the three absorption sites. By reducing the IFN-α dose from 50,000 to 25,000 IU/kg, the serum IFN-α levels vs time profile showed a tendency of dose-dependency. When the histological examination of small intestinal mucosa was carried out in this study, the small intestinal mucosa after the Gelucire44/14 patches administered and before it was administered, could not recognize impaired. From these results, the usefulness of oral patch system for the oral delivery of IFN-α has been proved in rats.
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DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
In this paper, we investigate rotor and stator designs of interior permanent synchronous motors for variable speed/load applications to reduce the carrier harmonic losses caused by pulse width ...modulated inverters. The rotor core and magnet shapes are determined by an automatic optimization method using electromagnetic field analysis that considers the inverter carrier. Appropriate stator-winding configurations are also investigated by this analysis. It is clarified that the total carrier harmonic loss can be reduced by more than 20% by optimizing both the stator and rotor shapes, whereas the other important characteristics are not considerably deteriorated.
The rapid shape change in Zr isotopes near neutron number N=60 is identified to be caused by type II shell evolution associated with massive proton excitations to its 0g_{9/2} orbit, and is shown to ...be a quantum phase transition. Monte Carlo shell-model calculations are carried out for Zr isotopes of N=50-70 with many configurations spanned by eight proton orbits and eight neutron orbits. Energy levels and B(E2) values are obtained within a single framework in good agreement with experiment, depicting various shapes in going from N=50 to 70. The novel coexistence of prolate and triaxial shapes is suggested.
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