• The Transactions of the Korean Institute of Power Electronics
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• v.24 no.6
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• pp.406-410
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• 2019

Three-level (3L) DC-DC converters are appropriate for high-input-voltage applications. Although the voltage stress of TL converter switches can be reduced to half of the input voltage, the primary side has a large circulating current, which degrades efficiency. In this study, a dual half-bridge cascaded TL converter is presented to reduce this circulating current and thus decrease the conduction loss of the primary circuit. Moreover, the proposed converter can reduce the voltage stress of rectifier diodes, thereby reducing their conduction loss. Therefore, efficiency can be improved by reducing the conduction loss of the primary circuit and rectifier diodes.

• Proceedings of the KSME Conference
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• 2001.06e
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• pp.661-667
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• 2001

This paper is concerned with the effects of periodically approaching upstream wakes on cascade-flow and loss. The reduced frequency of the periodic wakes was varied in the narrow range from 0.5 to 0.7. According to a wake-passing through the cascade, two velocity deficits appear near the boundary layer contour in the downstream from about 60% chord-length. The first velocity deficit is caused by a periodic wake and the second one appears after some delayed time. The second velocity deficit may be interpreted as the results of reattachment of flow-separation. The higher reduced frequency decreases the duration time of separation appearance and the lesser loss of aerofoil is resulted.

• Journal of the Korean Society of Tobacco Science
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• v.12 no.1
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• pp.9-18
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• 1990

To study the determinants which are involved in the loss of pathogenicity in wilt-inducing Pseudomoms solamcewum, several physlologica I functions were compared in a virulent P. solanacearum strain and an avirulent, spontaneously derived mutant strain. The polyacrylamide gel electrophoresis showed the distinction between two strains in the patterns and the relative intensity of proteins produced intracellularly or extracellularly. Enzyme assays showed that the level of polygalacturonase activity in the culture filtrate of the avirulent mutant was markedly reduced, while carboxymethylcellulase(rondoglucanase) activity in both strains were nearly negligible. These results suggest that the loss of pathogenicity in mutant strain is attributed in part to the reduced production of polygalacturonase. In audit ion, comparative analyses by agarose gel electrophoresis of DNA molecules isolated from both strains show that the pathogenicity genes of p. solanaceerum are not located on plasmid but are on chromosome.

• Journal of Plant Biology
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• v.31 no.3
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• pp.227-237
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• 1988

Effects of putrescine on senescence in detached leaves of Chinese cabbage (Brassica campestris L.) in the light were investigated. The putrescine as a potent antisenescence substane markedly inhibited chlorophyll and protein loss at the 10mM concentraton in the detached leaves during the dark incubation. In the light, however, putrescine showed the opposite effects to dark incubation. The chlorphyll loss by putrescine in the light was stopped with darktransfer, and inhibited competitively by a divalent cation Ca2+. In the light, putrescine reduced the protease activity. Putrescine, in the light, increased H2O2 content and reduced the activities of enzymes -superoxide dismutase (EC 1.15.1.1), peroxidase (EC 1.11.1.7), catalase (EC 1.11.1.6-involved in inhibiting the accumulation of free radicals. These results suggest that the effects of puterscine on chlorophyll and protein loss in detached leaves of Chinese cabbage in the light are related to the cationic nature of putrescine and the accumulation of free radicals.

• Proceedings of the IEEK Conference
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• 2001.06e
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• pp.245-248
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• 2001

This paper is indicating the problems, which are the conduction loss on the high frequency transformer, the protection of rectification diode as the snubber loss and the stress of switching main devices, as be made high current and high speed in the phase-shift switching full-bridge DC-DC converter is used the power supply’s main circuit of high capacity. To improve those problems, in this paper, it is proposed that is the resonant circuit auxiliary can be reduced conduction losses and stabilized output control. And, it is constructed prototype of the power supply as the result of computer simulations.

• Proceedings of the KIPE Conference
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• 2001.07a
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• pp.608-611
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• 2001

This paper is indicating the problems, which are the conduction loss on the high frequency transformer, the protection of rectification diode as the snubber loss and the stress of switching main devices, as be made high current and high speed in the phase-shift switching full-bridge DC-DC converter is used the power supply's main circuit of high capacity. In this paper, to improve those problems, it is proposed that is the resonant circuit auxiliary can be reduced conduction losses and stabilized output control. And, it is constructed prototype of the power supply as the result of computer simulations.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.436-439
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• 2000

Change of dielectric loss of use in high relative permitivity capacitor BaTiO$_3$ ceramic depends on Mn doping have been investigated. The powders used in this study were commercial BaTiO$_3$, TiO$_2$and, MnCO$_3$. Sample was fabricated by conventional ceramic process. The quantity of Mn was changed gradually from 0.lmol% to 10mo1%. The sintering densities were reduced with increasing amount of MnCO$_3$. This result is because of increase of low density second phase BaMnO$_3$. When the samples were doped by over 0.2mol% of MnCO$_3$, average grain sizes were enlarge to several tens ${\mu}{\textrm}{m}$. The dielectric losses were reduced by Mn doping to lmol% but, increased from lmol% to 10mo1% gradually.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.12
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• pp.1743-1749
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• 2000

An experiment was conducted to investigate the effect of supplementation of commercial phytase and ${\beta}-glucanase$ to wheat-soybean meal based layer diets. Control (17% CP) and reduced protein (13.5% CP) diets were compared with and without phytase and/or ${\beta}-glucanase$. Reducing dietary crude protein levels reduced the amount of N excreted by laying hens with no adverse affect on egg production or overall feed conversion ratio. There was, however, a slight reduction in average egg weight. When phytase was added to the control protein diets it was possible to reduce the level of dicalcium phosphate in the diet without a loss in performance and daily P output was reduced significantly. When phytase was added to the reduced protein diets, however, there was a dramatic loss in performance in the last four weeks of the study. Supplementation of ${\beta}-glucanase$ to wheat based layer diet did not appear to have beneficial affects in terms of laying performance and reducing nitrogen or phosphorus excretion. Combination of phytase and ${\beta}-glucanase$ had no positive effects on laying performance or reduction of DM, N and P.

• Journal of Nutrition and Health
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• v.34 no.5
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• pp.547-553
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• 2001

This study was designed to observe the change of body composition and nutrient metabolites and the excretion of minerals during complete fasting for 10 days in thirty women. Average loss of body weight was 7.98kg and body fat was gradually reduced after 9 days fasting, but the loss of lean body mass was reduced after 7 days fasting. Serum glucose level was sustained at constant level, but serum levels of blood urea nitrogen, free acid and $\beta$-hydroxybutyrate were significantly increased during fasting but decreased after re-feeding. Urinary excretions of 3-methylhistidine, total creatinine, and urea were high in the beginning of fasting but gradually decreased. Serum level of parathyroid hormone was significantly reduced by fasting but regained after re-feeding. Serum level of minerals was at the constant level throughout the experimental period. The urinary excretion of minerals(Ca, K, Mg, P) was significantly increased in the early stage of fasting and then reduced from 7 days, but the excretion of Zn was continuously increased until the late stage of fasting. These results showed that amino acid fatty acid released from the breakdown of muscle protein and body fat, respectively, were utilized for energy during fasting. Body weight and BMI were reduced because of the increased muscle protein breakdown and body water excretion during early stage of fasting, but the significant body fat loss was after 9 days fasting. Therefore, it could be suggested to fast for longer than 10 days if the reduction of body fat was planned by fasting, and recommed to exercise and ingest more vitamins and minerals to replace the excreted minerals during fasting. (Korean J Nutrition 34(5) : 547~553, 2001)

• KCID journal
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• v.21 no.1
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• pp.64-77
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• 2014

This study evaluated the soil loss considering the R-Factor value following the climate change. To calculate the soil loss of the basin in Jaun-ri, Hongcheon-gun which is the study area, the future climate change scenario and convenience revision were used to build the past 30 years, future 30 years R-Factor and it was applied to USLE model. As a result, as the R-Factor value declined a little in the future, the soil loss was also reduced but it corresponds to the 'very high' according to the OECD soil loss grade so the solution to reduce the soil loss is necessary and it can be used for another study material.