• Journal of Plant Biology
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• v.38 no.1
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• pp.25-32
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• 1995

The distribution of RNA in the anther wall of Brassica napus during male gametogenesis was followed by 3H-uridine autoradiography. Silver grain(SG) density was not above background in the anther wall just after microspore was released from tetrad callose wall. Significant accumulation of SGs occurred in tapetum, endothecium, and epidermis before microspore vacuolation. Accumulation of RNA in the tapetal cells was peak before the vaculation occurred in the microspore. With the onset of tapetal senescence at the partially vacuolated microspore stage, SGs decreased and they completely disappeared in the tapetum at the bicelled pollen stage. Accumulation of RNA in the endothecial cells was peak after the microspore mitosis and continued just after the generative cell mitosis. Appreciable SGs also occurred in cells of epidermis from nonvacuolate microspore stage to bicelled pollen stage. During this period, SG density was almost same and was not high as compared with tapetum or endothecium. At tricelled mature pollen stage, no incorporation occurred in anther wall. SGs were found mostly over the nucleouls and chromation of the cell nuclei.

• Journal of Welding and Joining
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• v.15 no.5
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• pp.84-91
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• 1997

The metal transfer phenomenon of the pulsed-GMAW is simulated by formulating the electromagnetic force incorporated with the Volume of Fluid algorithm. The free surface profiles, pressure and velocity distributions within the drop are computed numerically. Axial velocity and acceleration generated during peak current period are found to have a significant effect on drop detachment. Therefore, the accelerated inertia force becomes one of important factors affecting metal transfer in the pulsed-GMAW. When the pulse current parameters are selected properly, the molten drop is detached just after current pulse, and the operating range of the pulsing frequency increases with higher peak current and duty cycle. Calculated operating ranges show reasonably good agreements with the available experimental data.

• Magazine of the Korean Society of Agricultural Engineers
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• v.42 no.3
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• pp.76-88
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• 2000

AGNPS model is applied in this study to analyze the changes of non-point source pollutant according to AMC condition using probable rainfall. Probable rainfall of H-dam area by Gumber's extreme value distribution is computed through frequency analysis for each return period. 35 coarse grids are subdivided into 134 find grids of finite differential network to analyze peak flow soil loss quantity and nutrients of study area and the modified CN estimation equation shows good result about rainfall events-peak flow relationship. And as the consequence of estimation of soil loss quantity for each rainfall event soil loss quantity shows 120%-170% of actual soil loss quantity Regression analysis for the observed and calculated values of flow T-P AMC has an important effect on nutrients concentration of outflow and it if found that the excessive fertilization under AMC III condition may cause eutrophication by nutrients because the range of increase of outflow concentration appears relatively high.

• Preventive Nutrition and Food Science
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• v.5 no.1
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• pp.7-9
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• 2000

Variouss concentrationss of free malonaldehyde were prepared from 1,1,3,3-tetraethoxy propane (TEP). Spectrophoto-metric determination and HPLC analysis of free malonaldehyde instead of malonaldehyde-thiobaribituric acid (MA-TBA) complex were conducted. Malonaldehyde was well separated on a $\mu$Bondapak C18 column. The absorbances at 254 nm and the HPLC peak areas of free malonaldehyde increased with the increase in its concentration. The correlation coefficient between absorbances and peak areas was 0.998. The total time elapsed to conduct the whole procedure was less than 15 minutes. This method directly measured the amount of free malonaldehyde in a short period of time successfully. This procedure is expected to be used as a rapid, accurate and specific means to de-termine the development of lipid oxidation in food.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.6
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• pp.756-761
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• 2013

This paper propose the new demodulation method that can detect resolver signal's peak at the time of position estimation when the position information is required during current controller period. The proposed method is performed in a synchronous demodulation way with exciting signal and also cover a capability which can compensate the lag element of exciting signal caused by the resolver's inductive component and filter circuit. This paper carried out the experiment to investigate the validity and performance of the suggested method by using the test board made up of DSP and demodulation circuit. The test results show that the proposed method is theoretically clear and work completely as expected from making sure of sampling resolver signal's peak at the time of position estimation. In addition, Software position tracking algorithm is executed with the demodulated signals generated by the suggested method and an exact position can be estimated.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.769-772
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• 2006

The effects of high temperature on strength, elastic modulus and strain at peak stress of concrete were experimentally investigated. The type of test was the stressed test that a preload was applied to the specimen prior to heating and the load was sustained during the heating period. In this study, the level of preload was 25% of compressive strength at room temperature. All tests were conducted at various temperatures(20,100, 200, 300, 400, 500, 600 and $700^{\circ}C$) for concretes made with W/B ratios 46% and 32%. Test results showed that on the whole, the relative values of strength and elastic modulus, and the real strain value at peak stress were not influenced by the W/B ratio.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.50 no.3
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• pp.140-145
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• 2001

The instantaneous voltage drop is occurred when the fault is happened on the nearby feeders. The instantaneous voltage drop is continued during relatively short period. But, the effect of it can be very severe to some sensitive devices. That is, it can be the reason of restart or malfunction of some devices. And these phenomenons can cause the enormous economical damage and shorten the lifetime of the devices. In this paper, the device which can compensate the instantaneous voltage drop, is studied. Through the computer simulation using PSCAD/EMTDC, the validity of the control algorithm using peak detection method is verified. And the Dynamic Voltage Restorer(DVR) prototype is designed and constructed. Through the experiment, the function and performance of the DVR prototype is verified.

• Corrosion Science and Technology
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• v.18 no.2
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• pp.49-54
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• 2019

The purpose of this paper is to present failure analysis, of the heat exchanger tube in a district heating system. SS304 stainless steel is used, as material for the heat exchanger tube. The heat exchanger operates in a soft water environment containing a small amount of chloride ions, and regularly repeats operation and standstill period. This causes concentration of chloride ions on the outer surface of the tube, as well as repeat of thermal expansion, and shrinkage of the tube. As a result of microscopic examination, cracks showed transgranular as well as branched propagation, and many pits were present, at the initiation point of each crack. Energy disperstive spectroscopy analysis showed Fe and O peak, as well as Cl peak, meaning that cracks were affected by Cl ion. Failure of the tube was caused by chloride-induced stress corrosion cracking by thermal stress, high temperature, and localized enrichment of chloride ions.

• Asian Journal of Turfgrass Science
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• v.22 no.1
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• pp.35-48
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• 2008

Seasonal and regional occurrence of oriental beetle, Blitopertha (=Exomala) orientalis was investigated using pheromone traps and soil sampling at three golf clubs in Busan, Gunpo, and Gimpo from 2004 to 2007. Adults of Blitopertha orientalis were found from early June to late August, but peak times were different depending on the location and year. Peak day of adult occurrence of B. orientalis was 25 June,2006 and 22 June 2007 in Busan, but 30 June,2006 and 29 June,2007 in Gunpo. Mean numbers of B. orientalis adults attracted to pheromone trap varied with locations. Larval development was faster in Busan than in Gunpo. The 2nd instars of B. orientalis was found on 27 August, 2004 in Gunpo whereas 3rd instars were found in Busan in the same period. In Busan, overwintered 3rd instars pupated from early May to mid-June and emerged from early June. Eggs laid at this time were hatched from late June Most 3rd instars were found at middle August and started to overwinter. The peak time of mating was 20:00 to 22:00 hour of the day.

• Korean journal of food and cookery science
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• v.10 no.1
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• pp.45-50
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• 1994

Conventional Doenjang, three kinds of Improved Doenjang(A; koji: soybean: salt=53: 100: 33, B; koji: soybean: salt=100: 100: 40, C; koji: soybean: salt= 200: 100: 40) prepared with different ratio of koji and salt were made to study the changes in the general contents, characteristics bitter peptides, correlations between bitterness and overall eating quality. 1. Total nitrogen contents increased a little, and amino nitrogen contents in all samples increase markedly. Especially, Amino nitrogen contents of conventrional Doenjang increased more than others. Reducing sugars of doenjang prepared with Asp. oryzae were higher than conventional Doenjang and increased throughout the aging period and Doenjang prepared with Asp. oryzae were more acidic. 2. To characterize bitter peptides in fermented Doenjang, peptides were extracted with 2: 1(v/v) chloroform-methanol and separated by Gel chromato-graphy with Sephadex and TLC. After Gel chromatography and TLC, each fraction examined presence of bitterness and evaluated intensity of bitterness. Amino acid composition of the fractions showing bitter tastes were as follows. Conv. peak 1-1 Trp-(Asp, Arg, Thr, Ser, Glu, Pro)-Phe Imp. A peak 1 Trp-(Glu, Val, Arg, lie)-Phe Imp. B peak 1 Trp-(lie, Pro, Asp, Lys, Val, Glu)-Trp. Imp. C peak 1-2 Trp-(Try, Thr, Glu, Pro, Gly)-Phe 3. Sensory evaluation revealed that correlation coefficient between bitterness and overall eating guality was not high.