• 한국패류학회지
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• 제14권2호
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• pp.121-130
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• 1998

Studies on the distribution and growth of the mud mussel, Musculista senhousia, were carried out in the mud-tidal flat near Mokpo from August 1996 to July 1997. The patch distribution of the mussel was observed in the middle part of the tidalflat during the study period. Annual mean density was 8,215${\pm}$1,394 ind./m2 and annual mean biomass was 1,966.43${\pm}$668.49 g TWwt/m2 in total wet weight, 760.04${\pm}$279.13 gMWwt/m2 in meat wet weight, 209.93 ${\pm}$ 49.41 gMDwt/m2 in meat dry weight, and 109.66${\pm}$58.78 gAFDW/m2 in ash-free dry weight. The monthly mean size of shell length varied from 11.00 mm to 16.97 mm. Relationship between shell length (SL) and shell height (SH) showed a positively significant regression (SH=0.482SL+0.791, R2=0.940, P<0.001). Regressions of total wet weight (TWwt) (TWwt=7.601${\times}$10-5SL3.052, R2=0.905, P<0.001), and meat wet weight (MWwt) (MWwt=1.127${\times}$10-5${\times}$SL3.404, R2=0.784, P<0.001) on shell length were positively allometric, with highly significant correlation coefficient. The relationships between SL and meat dry weight (MDwt), and AFDW were MDwt=9.813${\times}$10-6${\times}$SL2.928 (R2=0.421), and AFDW=1.015${\times}$10-5${\times}$SL2.922(R2=0.810), respectively. The condition factor of the mussel has been increased from March and formed a peak in July and August. It was sharply dropped in September. These results suggest that the gonadal development of the species commenced to be occurred in spring and that main spawning occurred between August and September.

• 한국자동차공학회논문집
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• 제10권2호
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• pp.73-79
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• 2002

The NO emissions at the exhaust manifo1d were investigated with a fast NO analyzer to investigate the cycle-by-cycle variations on NO emissions level and the dependence of NO emissions on combustion. The measurement was performed with a part load condition with respect to the mixture ratios and the changes in loads at 1800rpm. The averaged values were obtained during 200 cycles. We found that there is characteristic pattern in 70 emissions from exhaust port and it was possible to set a representative value with the data sampled during specific period. As the load increased, the characteristics of NO emissions were more dependent on combustion pressures. It was also analyzed that the correlation between combustion pressures and NO emissions for different equivalence ratios tends to increase as the mixture goes leaner, Furthermore, this correlation for the lean mixture near the lean limit seemed to be kept.

• 한국자동차공학회논문집
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• 제9권3호
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• pp.9-17
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• 2001

This paper is the second of 3 companion papers which investigate axial stratification process. In-cylinder fuel behavior has been investigated in the port injected Sl engine by visualizing for the purpose of understanding stratification. Planar laser light sheet from an Nd:YAG laser has been illuminated through the transparent quartz cylinder of the single cylinder optical engine and the Mie scattered light has been captured through the quartz window in the piston head with an ICCD camera. Fuel has been replaced with an air-ethanol mixture to utilize atomized fuel spray fur the visualization purposes. This results have been compared with steady flow concentration measurement. For low/medium swirl port, the early injection makes such a fuel distribution state that is upper-rich, middle-lean and lower-rich along the combustion chamber and cylinder by tumbling motion. On the other hand, the late injection induces upper-rich, middle-lean and lower-rich state due to the short fuel penetration.

• Preventive Nutrition and Food Science
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• 제8권3호
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• pp.239-244
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• 2003

Recently, we reported (J Korean Soc Food Sci Nutr, 31(3): 516-520, 2002) that Semisulcospira libertina (Marsh Snail) pretreatment has a hepatoprotective effect on $CCl_4$-induced liver damage in rats. The purpose of this study was to investigate the possible mechanisms of hepatoprotection by S. libertina (SL) on liver injury induced by acetaminophen (AA). Male ICR mice were pretreated with dehydrated powder of SL once daily for three consecutive days, given a single toxic dose of AA (450 mg/kg) and liver function determined 24 h later. Liver damage was assessed by quantifying serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and sorbitol dehydrogenase (SDH) activities, and by measuring hepatic lipid peroxidation. To confirm possible mechanism(s), the content of hepatic glutathione (GSH) and gene expression of tumor necrosis factor a (TNF $\alpha$) mRNA by reverse transcription-polymerase chain reaction (RTPCR) were also measured. Pretreatment with SL dramatically lowered AA-elevated ALT, AST and SDH activities. SL pretreatment decreased AA-produced lipid peroxidation by 11% and restored the AA-depleted hepatic GSH by 27%. Furthermore, SL markedly suppressed the expression of TNF $\alpha$ mRNA induced by AA. Our findings revealed that the possible hepatoprotective mechanisms of SL could be attributed, at least in part, to the glutathione-mediated detoxification as well as the regulation of TNF $\alpha$ mRNA expression.

• 한국농공학회지
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• 제15권1호
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• pp.2913-2924
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• 1973

이와같은 방법(方法)에 의(依)하여 얻은 몇가지 시험결과(試驗結果)를 요약(要約)하면 다음과 같다. 1. 어느 시험구(試驗區)를 막론(莫論)하고 건조진행(乾燥進行)은 표층토(表層土)가 라지구(裸地區)보다는 초지구(草地區)가 그 진행속도(進行速度)가 좀빠른 경향(傾向)을 나타냈다. 2. 건조과정(乾燥過程)에 강우(降雨)가 있으며 토양수분(土壤水分)은 강우침투경로(降雨浸透經路)를 통(通)하여 포장용수량(圃場容水量) 또는 수분당량(水分當量) 부근(附近)으로 회복(回復)하고 있다. 3. 성층토양(成層土壤)에서 하층토(下層土)의 토성(土性)이 상층토(上層土)의 건조(乾燥)에 미치는 영향(影響)은 다음과 같이 설명(說明)된다. 가. 하층토(下層土)가 S이고 토층토(土層土)가 CL 또는 SL인 경우에 이 CL 또는 SL의 건조(乾燥)는 포장용수량(圃場容水量)이 적은 하층(下層)의 S가 어느정도(程度) 모관수공급(毛管水供給)의 차단층(遮斷層)이 되어 하층토(下層土)가 SL 또는 CL로 되었을 때보다 훨씬 건조(乾燥)가 빨리 진행(進行)하며 CL보다는 SL쪽이 현저(顯著)하게 빨리 건조(乾燥)한다. 나. 하층토(下層土)가 SL이고 상층토(上層土)가 S 또는 SL인경우에 이 S 또는 CL의 건조(乾燥)는 포장용수량(圃場容水量)이 비교적(比較的) 크고 또 모관수전도도(毛管水傳導度)도 비교적(比較的) 원활(圓滑)한 하층(下層)의 SL로 인(因)하여 그 진행속도(進行速度)가 가장 완만하며 S보다는 CL쪽이 더빨리 건조(乾燥)하는 경향(傾向)이다. 다. 하층토(下層土)가 CL이고 상층토(上層土)가 S 또는 SL인 경우에 이 S 또는 SL의 건조(乾燥)는 포장용수량(圃場容水量)이 가장 크나 모관수전도도(毛管水傳導度)가 가장느린 하층(下層)의 CL로 인(因)하여 그 진행속도(進行速度)가 비교적(比較的) 빠른 편(便)이며 S보다는 SL쪽이 더 발리 건조(乾燥)하는 경향(傾向)이다. 4. 상층토양(上層土壤) 및 하층토양(下層土壤)에서의 함수비(含水比)에 대(對)한 1일간(日間)의 시간적(時間的) 변화(變化)를 보면 상층토양(上層土壤)이 CL 및 SL에 있어서는 기온(氣溫)이 상승(上昇)하는 $12{\sim}15$시(時) 사이 까지는 함수비(含水比)가 감소(減少)되고 18시(時) 이후(以後)부터는 약간(若干) 회복(回復)하는 경향(傾向)을 보이는데 이에 반(反)하여 S에 있어서는 기온(氣溫)이 상승(上昇)하는 $12{\sim}15$시(時)에 함수비(含水比)가 Peak점(點)을 이루는 경향(傾向)을 보였으며 하층토양(下層土壤)에서의 함수비(含水比)는 CL, SL 및 S모두 기온상승(氣溫上昇)에 따라서 약간감소(若干減少)하는 경향(傾向)을 나타냈고 구름낀날의 함수비(含水比)의 변화(變化)는 CL, SL 및 S공(共)히 맑은 날에 비(比)하여 약간(若干) 작은 경향(傾向)을 보였다. 5. 적산계기증발량(積算計蒸發量)에 대(對)한 적산토양수분소비율(積算土壤水分消費率)은 일반적(一般的)으로 화지구(華地區)가 라지구(裸地區)보다 큰 경향(傾向)을 보였으며 시일(時日)의 경과(經過)에 따라 그 율(率)이 감소(減少)하는 경향(傾向)을 보였고 또 그것은 초기(初期)에는 주(主)로 상층토양(上層土壤)의 토성(土性)에 좌우(左右)되고 후기(後期)에는 하층토양(下層土壤)의 토성(土性)에 많이 좌우(左右)되는 경향(傾向)이었다. 6. 적산토양수분소비율(積算土壤水分消費率)은 하층토(下層土)가 SL 또는 S이고 상층토(上層土)가 CL인 경우(境遇)에 하층(下層)이 SL인 경우(境遇)가 S인 경우보다 변화폭(變化幅)에 컸으며, 하층(下層)이 CL, 또는 S이고 상층(上層)이 SL인 경우(境遇)는 가장 큰 값을 나타냈는데 하층(下層)이 CL인 소우(塑遇)의 그 값은 S인 경우보다 약간(若干)큰 경향(傾向)을 보였다. 또한 하층(下層)이 CL 또는 SL이고 상층(上層)이 S인 경우는 위에 말한 두 경우보다도 작은 값을 보였으며 하층(下層)이 CL인 경우(境遇)가 SL인 경우보다 더욱더 작은 값을 나타내는 경향(傾向)을 보였으며, 즉(卽) 본시험(本試驗)에서의 토양수분(土壤水分) 소비율(消費率)은 대체(大體)로 SL/CC> SL/S>CL/SL> CL/S$\fallingdotseq$S/SL> S/CL>의 순위(順位)로 되었다.

• 한국식품영양과학회지
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• 제39권10호
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• pp.1487-1494
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• 2010

본 연구는 coconut oil 분별유를 사용하여 코코아 버터 대체유지를 개발하고자 하였으며, RP-HPLC 및 지방산 분석을 수행하여 그 결과를 commercial CBR와 비교하였다. TAG의 PN 분석결과, 코코아 버터 대체유지에서 전체 TAG의 93.08%가 PN=40~48에 포함되었고, commercial CBR는 94.11%이었다. 지방산조성 분석결과, commercial CBR와 코코아 버터 대체유지의 불포화지방산이 차지하는 비율은 각각 18.68%와 17.39%로 유사하였다. 두 유지 모두 지방산 중 가장 높은 비율을 차지하는 지방산은 palmitic acid로 코코아 버터 대체유지에서 46.03%, commercial CBR에서 47.75%이었으며, TAG의 sn-2 위치에서 불포화지방산의 비율은 각각 23.22%와 16.06%로 코코아 버터 대체유지가 높았다. 두 유지 모두 $30{\sim}45^{\circ}C$ 온도 구간에서 급격한 용융곡선을 가짐으로써 코코아 버터 대체유지로서의 특성을 가지고 있었다. Polymorphic form 분석결과, 제조된 코코아버터 대체유지와 commercial CBR에서 $4.24{\AA}$과 $3.83{\AA}$에서 short spacing을 나타내며, ${\beta}'$ 형태의 결정형을 나타내었다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.753-756
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• 2005

Rapid prototyping (RP) technologies are mainly performed by layered manufacturing (LM) process which manufactures 3D physical objects by depositing 2D sections in a direction. Thus, deformations are apt to occur in overhanging area of the RP processed part. Also, excessive adhesion between part and platform of the RP apparatus is generated. In order to prevent these problems, most of the RP technologies adopt support structure. Main element to support a part in the support structure is strand. In actual field, however, the number of strand is determined by the software operating reference guide or RP system operator's experience. In this paper, a methodology to determine the optimal strand spacing is presented through experiments and measurements for the SL part deformation by change of strand spacing and part weight in the support structure of the stereolithography.

• 한국공작기계학회논문집
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• 제15권3호
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• pp.32-38
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• 2006

During stereolithography processes, the shape errors such as curl distortion and distortion of side face are generated due to the shrinkage of liquid resins. In this study, the effects of dimension of part and structure of supports on the shape error are examined. Cubic specimens which have different thicknesses are manufactured and their deformations are measured with CMM. Thicker part generates smaller curl distortion of top face and larger of bottom face. Also thicker part generates larger distortion of side face until part thickness increases to about 20mm. Larger stiffness of supports which is obtained by shorter spacing of the supports and line type contact instead of point type contact generates smaller shape error of the part.

• 한국건축시공학회지
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• 제7권2호통권24호
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• pp.99-106
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• 2007

The purpose of this study presents in Relations between cracks in self-leveling material and quality of floor groundwork surface are experimentally examined. As the first stage, the experiment to observe cracks in self-leveling material constructed on floor groundwork made from various kinds of concrete was carried. As a result, following basic findings were obtained. First, observation of cracks should be continued until an increase in width of cracks stop, without constructing any finishing material. Second, degree of cracks may be indicated quantitatively by the product of length and width. Finally, Cracks and separation is not be influenced by specimen size. Based on these findings, the method of predicting cracks by evaluating surface layer quality of floor groundwork will be established.

• 한국공작기계학회논문집
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• 제14권6호
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• pp.61-67
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• 2005

During stereolithography processes, one of the main sources of dimensional error of prototype is the distortion effect owing to the shrinkage of resin. In this study, the effects of dimension of specimen, such as length, width, and thickness, on the curl distortion is examined. During the SL processes, the variation of curl distortion ewer is measured according to the number of layers, Through this study, it is verified that there is a big difference of the distortion error in both direction and magnitude between before and after the supports are removed. It Is also observed that end profile of the test part and the upper side around the border are also distorted due to the shrinkage of the resin.