• Applied Microscopy
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• v.37 no.3
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• pp.185-198
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• 2007

Spermiogenesis in Japanese white-toothed shrew. Crocidura dsinezumi was investigated by transmission electron microscope. Spermiogenesis was divided into 12 phases 14 steps, based on the morphological features of the nucleus and change of organelles in cytoplasm. The nucleus of spermatids in Golgi (step $1{\sim}2$) phase were spherical; however, they were changed into oval in the cap (step $3{\sim}6$) phase. Flagellum appeared in the middle of acrosomal phase; on the other hand, slender and long spermatid head was formed in maturation phase. The head of spermatids faced the lumen in step 1 to step 6 (from Golgi to cap phase), but, in step 7 to step 14 (from acrosomal to spermiation phase), it turned its head to the basal lamina of the seminiferous epithelium. The nucleus and acrosome were elongated maximally in step 10. The condensation of chromatin started in late acrosomal (step 10) phase, and it was completely finished and homogenized in the middle of maturation (step 12) phase. Multivesicular body appeared near the acrosomal vacuole during the middle cap (step 5) phase, and a large number of them were observed near the Golgi apparatus in the late cap (step 6) phase. Considering all the results, the spermiogenesis might be useful information to analyse the differentiation of spermatogenic fells.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.6
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• pp.1152-1157
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• 2001

Two kinds of samples were prepared from the loin in the carcass with grade B2 and D, which were chilled for 24 hour after slaughter. The fresh beef in this study were obtained by chilling the loin for 1 day after wrapping them. On the other hand, the chilled beef were obtained by cutting the loin by 500 g and chilling them for 30 day after vacuum packing. The experiment was carried out to compare the palatability related with characteristics of loin with grade B2 and D and to investigate the chilling effect of the loin with grade D. In the case of fresh beef, it was found that the loin with grade B2 has better meat color, but lower pH, lactic acid content, and myoglobin content, than them of the loin with grade D. Also, the loin with grade B2 has lower tenderness due to its low hardness and chewiness, and high myofibrillar fragmentation index (MFI). Furthermore, it has high monounsaturated fatty acid/saturated fatty acid (MUFA/SFA) and ATP content, and good raw meat aroma. It also shows an excellent palatability of cooked meat, although it has low cooking loss and heat shotening. On the other hand, the loin with grade D has higher chilling effect on hardness, chewiness, MFI and MUFA/SFA, than them of the loin with grade B2. However, in the case of chilled beef, the loin with grade D shows much worse tenderness, cooked meat aroma, and palatability than them of the loin with grade B2.

• Food Science and Preservation
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• v.12 no.4
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• pp.344-349
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• 2005

Microwave-assisted process (MAP) was applied to extract antioxidant-related components from Thymus quinquecostatus var. japonica Hara. Microwave power(2,450 MHz, $0{\sim}160$ W) and extraction time($1{\sim}5\;min$) were used as independent variables($X_i$) for central composite design to yield 10 different extraction conditions. Response surface methodology was applied to predict optimum extraction conditions for dependent variables of extracts, such as total yield, total phenolics, flavonoid, and electron donation ability depending on different powers and extraction times of MAP. Determination coefficients($R^2$) of regression equations for dependent variables were higher than 0.93 excluding that of total phenolics, and microwave power was predicted more influential than extraction time in MAP (p<0.05). The optimal extraction time for each dependent variable was ranged from 3.36 to 4.97 min, but microwave power showed wide ranges depending on variables. The superimposed contour maps for maximized dependent variables illustrated extraction conditions of 64 to 100 W in microwave power and 2.9 to 4.0 min in extraction time.

• Food Science and Preservation
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• v.30 no.4
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• pp.683-690
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• 2023

The study was conducted to confirm the possibility of producing alcohol beverages from Dae-hong peaches. Upon examining the quality characteristics of distilled soju using Dae-hong peaches, the alcohol content was 1.12 to 1.16 times higher than that from the atmospheric distillation method. Soju with 20 % peach extract content had the highest alcohol content and the lowest volatile acid content, indicating a low possibility of causing irritating odors. Acetaldehyde was 1.3-1.94 times lower in vacuum-distilled soju, and methanol was not detected in all samples. The absorbance value of furfural, a burnt component generated during distillation is high in atmospheric distillation, which can cause irritating odors. Upon examining the volatile fragrance components, isoamylalcohol and 1-propanol were found to be the main components, both of which were the highest in the treatment group with 20 % peach extract content. The electronic nose analysis revealed that this group showed the most opposing flavor patterns to the control group, and when distilled under reduced pressure with 20 % addition of Dae-hong peaches can produce high-quality soju.

• Parasites, Hosts and Diseases
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• v.22 no.1
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• pp.21-29
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• 1984

A scanning eletron microscopic study was performed to observe the tegumental surface of adult Fibricola seoulensis. The adult worms were collected from the small intestine of mice 5 days to 3 weeks after experimental infection with the metacercariae. The metacercariae were obtained from the viscera of the snakes, Matrix tigrina lateralis, by artificial digestion technique. The results were as follows: 1. The tegument of anterior body was covered with cobblestone-like cytoplasmic processes and that of posterior body showed finger-like processes. The posterior body had 4-5 large transverse wrinklings which formed many discontinued shallow rugae. 2. The entire surface of anterior body was regularly arranged with the spines of which tips diverged into 3 to 4 points. They were densely packed in anterior mid-median portion of dorsal surface where appeared a few spines indented upto 5 points. Farther laterally and posteriorly from this portion, the pointed spines were more sparse and became single tipped and extended to anterior one-third of posterior body, 3. The posterior surface of oral sucker was armed with 50-60 spines having 2-3 tips and ventral sucker also covered with such spines. On anteriormost dorsal surface arranged 60-70 spade-shaped spines. The tribocytic organ was armed with many stout recurved pile-like spines arranged radially. 4. There were 3 types of sensory papillae. The ciliated knob-like (Type I) papillae were almost bilaterally symmetrical in ventral and dorsal surfaces of anterior body, and abundant especially aroundbases of oral and ventral suckers, tribocytic organ, and in lateral margins of anterior body. About 24 non-ciliated round swellings (Type II) were observed around each lip of oral and ventral suckers. The plate-like elevated papilla without cilium (Type III) was found to distribute only in posterior body. These 3 types of papillae seem to be tangoreceptive and/or rheoreceptive in function when their morphology and distributions are considered.

• Bulletin of the Korean Space Science Society
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• 2003.10a
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• pp.62-62
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• 2003

과학위성 1호에는 위성의 임무를 수행하기 위하여 광학계, 구조부, 및 전자부 등 여러가지 부품들이 실장되는데, 그 중 전자부의 가장 중요한 부품 중의 하나인 인쇄회로기판(Printed Circuit Board, PCB)의 우주환경에서의 특성 대해서 논의하고자 한다. Solder Resistor(Solder Mask)의 화학성분이 위성체가 작동하는 우주환경에서 위성체 임무수행 시 발생할 수 있는 out-gassing으로 인해 위성체가 본연의 임무 실패라는 결과를 초래할 수 있다 NASA 및 ESA의 Out-gassing에 관한 규정과 TRW에 의한 KOMSAT에 사용된 재료의 진공상태의 Outgassing에 관한 내용에 의하면, 재료의 진공상태와 Out-gassing은 America Society for Testing and Materials에서 제시한 ASTM E959 기준에 따라 제작된다. 일반적으로 우주 환경에서 광학계나 전자부의 원활한 동작을 위해서는 인쇄 회로 기판의 총 질량손실(Total Mass Loss, TML)은 1.00%을 넘지 말아야 하며, 휘발성 응축 질량 (Collected Volatile Condensable Mass, CVCM)은 0.1% 미만이어야 한다. Total Mass Loss(TML) 방법은 대기중에서 측정한 질량과 진공 조건에서 변화되는 질량을 측정함으로써 진공조건에서의 탈기체 특성을 측정하는 방법이다. 본 연구에서는 Solder Resistor(Solder Mask)의 탈기체 측정을 위한 진공챔버의 측정방법 및 진공 형성 과정을 기술하고 실제 과학위성1호에 장착될 시료를 예로 들어 인쇄회로기판에 입힌 Solder Resistor(Solder Mask)가 우주환경인 진공상태에서 위성체 부품의 작동 시 발생할 수 있는 탈기체되는 정도를 질량의 변화분으로 측정하여 위성체가 우주 환경에서 본연의 임무를 안전하게 수행할 있는지를 검증하였다.부분이다.다.향을 해석하고 시뮬레이션 하였다.Device Controller)는 ECU로부터 명령어를 받아서 arm 및 safe 상태에 대한 텔리 메트리 데이터를 제공한다 그리고, SAR(Solar Array Regulator)는 ECU로부터 Bypass Relay 및 ARM Relay에 관한 명령어를 받아 수행되며 그에 따른 텔리 메트리 데이터를 제공한다. 마지막으로 EPS 소프트웨어를 검증하는 EPS Software Verification을 수행하였다 전력계 소프트웨어의 설계의 검증 부분은 현재 설계 제작된 전력계 .소프트웨어의 동작 특성 이 위성 의 전체 운용개념과 연계하여 전력계 소프트웨어가 전력계 및 위성체의 요구조건을 만족시키는지를 확인하는데 있다. 전력계 운용 소프트웨어는 배터리의 충ㆍ방전을 효율적으로 관리해 3년의 임무 기간동안 위성체에 전력을 공급할 수 있도록 설계되어 있다this hot-core has a mass of 10sR1 which i:s about an order of magnitude larger those obtained by previous studies.previous studies.업순서들의 상관관계를 고려하여 보다 개선된 해를 구하기 위한 연구가 요구된다. 또한, 준비작업비용을 발생시키는 작업장의 작업순서결정에 대해서도 연구를 행하여, 보완작업비용과 준비비용을 고려한 GMMAL 작업순서문제를 해결하기 위한 연구가 수행되어야 할 것이다.로 이루어 져야 할 것이다.태를 보다 효율적으로 증진시킬 수 있는 대안이 마련되어져야 한다고 사료된다.$\ulcorner$순응$\lrcorner$의 범위를 벗어나지 않는다. 그렇기 때문에도 $\ulcorner$순응$\lrcorner$과 $\ulcorner$표현$\lrcorner$의 성격과 형태를 외형상으로

• Korean journal of food and cookery science
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• v.22 no.2 s.92
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• pp.237-243
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• 2006

This study investigated the development of increased health promotion and higher quality of Gardenia jasminoides noodles. Gardenia jasminoides powder was extracted with water and 70% ethanol, after which their electron donating ability (EDA) and nitrite scavenging ability (NSA) were tested. EDA at $300{\sim}1,000$ ppm of water extract ranged from 65% to 86% and that of ethanol extract from 69% to 91%. NSA of water extract was 79% and ethanol extract was 88% at 1,000 ppm both peaked at pH 1.2. NSA was increased with increasing concentration of extracts and decreasing pH. The quality characteristics of Gardenia jasminoides noodles were evaluated by shelf life, color and sensory evaluation. Total viable cells in Gardenia jasminoides noodles during storage at 5? were $0.2{\sim}0.3$ log cycles, which were lower than those of the control and the shelf-life was expanded. Redness (a) of the dried and cooked noodles was decreased with increasing Gardenia jasminoides concentration (p<0.05). Yellowness (b) of the noodles was increased with increasing Gardenia jasminoides concentration in both the dried and cooked noodles. In sensory evaluation, dried and cooked noodles with $0.2{\sim}0.3%$ Gardenia jasminoides powder d significantly higher scores in overall acceptability(p<0.05).

• Journal of the Korean Society of Food Culture
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• v.19 no.5
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• pp.499-505
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• 2004

The present study was conducted to investigate extraction characteristics and antioxidative activity of Cassia tora L. extracts. Cassia tora L. was extracted by reflux extraction under different extraction conditions including solvent. The solid yield, turbidity, color value, titratable acidity, free sugar contents, electron donating ability and superoxide dismutase-like ability of Cassia tora L. extracts were determined. The highest solid yield value was obtained with water of 10 fold. No significant difference in turbidity and color value were found among the extracts prepared with various extraction solvents, 75% ethanol, 50% ethanol and water. The highest titratable acidity was obtained with 50% ethanol of Cassia tora L.. The free sugar contents of Cassia tora L. extracted with water showed the highest value. Cassia tora L. extracts with water included higher contents of free sugar compared with then of the other solvent extracts, 50% ethanol and 75% ethanol extracts. The total polyphenol compound content of Cassia tora L. extracted with 50% ethanol showed the highest value. Cassia tora L. extracts with 50% ethanol included higher contents of total polyphenol compound compared with those of the other solvent extracts, water and 75% ethanol extracts.

• Korean journal of food and cookery science
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• v.22 no.5 s.95
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• pp.728-735
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• 2006

This study investigated the development of health promoting high quality Mumalangi Kimchi. Angelica gigas Nakai leaves (AGL) were extracted with water and 70% ethanol, and the extracts tested for their electron donating ability (EDA), nitrite scavenging ability (NSA) and inhibitory effects on MDA and A549 cells. The EDA in 100-1,000 ppm water extracts from AGL ranged from 40 to 80%, but that of the ethanol extracts ranged from 37 to 81%. The NSA increased with increasing AGLconcentration in the extracts and decreasing pH. The NSA of the 1,000 ppm water and ethanol extracts from AGL were 29 and 35%, respectively, at pH 1.2. The inhibition ratios of the water and ethanol extracts from AGL on MDA cell growth were 35 and 32%, while those on A549 cell growth were 27 and 23%, respectively, at 1,000 ppm. After sun drying radishes for 15 hours, for the preparation of Mumalangi, the water contents were higher in summer radishes (39.5%) than fall radishes (32.6%) the color of summer radish also changed to brown. During storage of Mumalangi Kimchi, with the addition of 1-3% AGL, at 20?for 4 weeks, the yeast growth was inhibited. The shelf-life of Mumalangi Kimchi was extended by the addition of AGL. In the sensory evaluation of Mumalangi Kimchi, that with the addition 2% AGL had the highest scores for color, flavor, taste, texture, after taste and overall acceptability. Mumalangi Kimchi with the addition of 2% AGL had significant high scores for both taste and overall acceptability (p.0.05).

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.4
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• pp.456-465
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• 2019

PHEV(Plug in Hybrid Electric Vehicle) and BEV(Battery Electric Vehicle) equip high voltage batteries to drive motor and vehicle electric system. Those vehicle require OBC(On-Board Charger) for charging batteries and LDC(Low DC/DC Converter) for converting from high voltage to low voltage. Since the charger and the converter actually separate each other in electrical vehicles, there is a margin to reduce the vehicle weight and area of installation by integration two systems. This paper studies a 1.5kW LDC converter that can be integrated into an OBC using an isolated current-fed converter by simplifying the design of LDC transformers. The proposed LDC can control the final output voltage of the LDC by using a fixed arbitrary output voltage of the bidirectional buck-boost converter, so that Compared to the existing OBC-LDC integrated system, it has the advantage of simplifying the transformer design considering the battery voltage range, converter duty ratio and OBC output turn ratio. Prototype of the proposed LDC was made to confirm normal operation at 200V ~ 400V input voltage and maximum efficiency of 91.885% was achieved at rated load condition. In addition, the OBC-LDC integrated system achieved a volume of about 6.51L and reduced the space by 15.6% compared to the existing independent system.