• The Korean Journal of Physiology
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• 제3권1호
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• pp.1-9
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• 1969

Relationships between red ceil volume $(^{51}Cr-cell)$, total blood volume (red cell volume divided by hematocrit ratio), and extracellular fluid volume (SCN distribution space) and body weight (ranging between 73 and 384 grams) or lean body mass were studied in 59 nembutalized rats. Lean body mass was determined by means of underwater weighing method on rats clipped and eviscerated. There were positive correlations between body weight or lean body mass and the absolute values (in milliliters) of body fluid volumes. Body fluid volumes expressed on the body weight or lean body mass basis, however, showed negative correlations between body weight (grams) or lean body weight (grams) with one exception. Red cell volume expressed as % lean body mass showed a positive correlation with lean body mass. The other results are summarized as follows: 1. Body density of rats was 1.0561 $(range:\;1.0123{\sim}1.0781)$ and 19.8% body weight of total body fat was obtained. The mean value of lean body mass was 80.2% body weight 2. The correlation between body weight and lean body mass was high, namely, coefficient of correlation was r=.99. 3. The correlation between the absolute value of red cell volume (ml) and body weight showed a high correlation, namely, r= 92 and between the lean body mass coefficient of correlation was r=.93. On a weight basis, red cell volume was 2.67 ml/100 gm body weight or 3.48 ml/100 gm lean body mass. The coefficient of correlation between body weight (grams) and red cell volume (% body weight) was r=-. 30. The coefficient of correlation between lean body mass (grams) and red cell volume (% lean body mass) was r=. 50. Thus, the following regression equation was obtained. Red cell volume (% lean body mass)=. 00243 Lean body mass (gm)+3. 12. 4. Total blood volume was 6.06% body weight or 7.83% lean body mass. The correlation between these blood volume values and body weight or lean body mass were negative, namely, r= -.43 and r=-.42 respectively. 5. Extracellular volume (SCN space) was 30.0% body weight or 37.2% lean body mass. These percentage values showed negative correlations between body weight or lean body mass and coefficients of correlation were r=-.40 and r=-.54 respectively. 6. The rate of increase in body weight or lean body mass is accompanied by a smaller rate of increase in blood volume and extracellular fluid volume. The rate of increase in red ceil volume paralled that of lean body mass.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2010년도 제39회 하계학술대회 초록집
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• pp.17-17
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• 2010

This paper address technical issues in calibrating discharge coefficients of sonic nozzles used to measure the volume flow rate of low vacuum dry pumps. The first challenging issue comes from the technical limit that their calibration results available from the flow measurement standard laboratories do not fully cover the low vacuum measurement range although the use of sonic nozzles for precision measurement of gas flow has been well established in NMIs. The second is to make an ultra low flow sonic nozzlesufficient to measure the throughput range of 0.01 mbar-l/s. Those small-sized sonic nozzles do not only achieve the noble stability and repeatability of gas flow but also minimize effects of the fluctuation of down stream pressures for the measurement of the volume flow rate of vacuum pumps. These distinctive properties of sonic nozzles are exploited to measure the pumping speed of low vacuum dry pumps widely used in the vacuum-related academic and industrial sectors. Sonic nozzles have been standard devices for measurement of steady state gas flow, as recommended in ISO 9300. This paper introduces two small-sized sonic nozzles of diameter 0.03 mm and 0.2 mm precisely machined according to ISO 9300. The constant volume flow meter (CVFM) readily set up in the Vacuum center of KRISS was used to calibrate the discharge coefficients of the machined nozzles. The calibration results were shown to determine them within the 3% measurement uncertainty. Calibrated sonic nozzles were found to be applicable for precision measurement of steady state gas flow in the vacuum process. Both calibrated sonic nozzles are demonstrated to provide the precision measurement of the volume flow rate of the dry vacuum pump within one percent difference in reference to CVFM. Calibrated sonic nozzles are applied to a new 'in-situ and in-field' equipment designed to measure the volume flow rate of low vacuum dry pumps in the semiconductor and flat display processes.

• 한국어류학회지
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• 제22권3호
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• pp.195-200
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• 2010

대구 부화자어 대량방류를 위한 기초 연구로서 대용량 부화기를 이용한 대구 수정란 부화 방법을 검토하였다. 기존의 용량 15L와 시험용 42L인 부화기에 수정란을 수용한 결과 9일째 생존율이 48.3%와 50.4%로 나타나 부화기 용량차이에 따른 생존율은 유의한 차이가 없었다. 제작한 실험 부화기와 기존의 원형수조에서 수정란 생존율을 비교한 결과 40.0~71.2%로 부화기에서 높아 대구 수정란 부화에 실험 부화기가 효율적인 것으로 사료된다. 또한 42 L 부화기에 수정란 5,000 mL (약 825만 개)를 수용하여도 높은 부화율을 유지하였다. 결과적으로 대구 수정란 부화 시 대용량 부화기를 이용할 경우, 고밀도로 수용하여도 높은 수정란 생존율 유지가 가능하고 사육 공간과 인력 및 경비를 절감할 수 있을 것으로 생각된다. 또한 원형수조에 비하여 사육수 절약 (6,700 mL/min)과 수정란 그룹별 수용이 가능하다는 장점이 있다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제54권11호
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• pp.477-482
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• 2005

We have investigated volume resistivity and thermal properties showed by changing the content of carbon black which is the component parts of semiconducting shield in underground power transmission cable. Specimens were made of sheet form with the nine of specimens for measurement. Volume resistivity of specimens was measured by volume resistivity meter after 10 minutes in the preheated oven of both 25$\pm$1[$^{\circ}C$] and 90$\pm$1[$^{\circ}C$]. And specific heat (Cp) and thermal conductivity were measured by Nano Flash Diffusivity and DSC (Differential Scanning Calorimetry). The measurement temperature ranges of specific heat using the BSC was from 20[$^{\circ}C$] to 60[$^{\circ}C$], and the heating rate was 1[$^{\circ}C$/min]. And the measurement temperatures of thermal conductivity using Nano Flash Diffusivity were both 25[$^{\circ}C$] and 55[$^{\circ}C$]. Volume resistivity was high according to an increment of the content of carbon black from these experimental results. And specific heat was decreased, while thermal conductivity was increased by an increment of the content of carbon black. And both specific heat and thermal conductivity were increased by heating rate because volume of materials was expanded according to rise in temperature.

• 연구논문집
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• 통권26호
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• pp.95-102
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• 1996

The carbide growth behavior of MAR-M247 LC alloy was investigated by directional solidification and quench method. The carbide volume fraction, trapping and growth behavior were correlated with the growth rate. It was found that the carbide volume fraction decreases at slower growth rate. This decreasing was caused by lower solid-liquid interface trapping ability at the slower growth rate.

• 대한기계학회논문집B
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• 제22권4호
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• pp.520-529
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• 1998

Heat and mass transfer behaviors of metal hydride beds were predicted by solving a set of volume-averaged equations numerically both for the gas (hydrogen) and the solid(metal hydride) phases. Time variations of temperature and hydrogen concentration ratio distributions were obtained for internally cooled, cylindrical-shaped beds with metal(aluminum) fins imbedded in them. Also, time variations of the space-averaged hydrogen concentration ratio were obtained. Temperature and velocity of the coolant, hydrogen pressure at the gas inlet, and the fin spacing were taken as the parameters. The hydrogen absorption rate increases with the higher velocity and the lower temperature of the coolant, and with the decrease of the fin spacing. Increasing of the hydrogen pressure at the gas inlet also promotes the rate of absorption though the increasing rate gradually slows down. The amount of the hydrogen storage per unit volume of the bed decreases with the tighter fin spacing despite of the higher absorption rate ; therefore, there should be an optimum fin spacing for a given volume of the system and the amount of the hydrogen storage, in which the absorption rate is the highest.

• 대한수의학회지
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• 제28권2호
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• pp.271-277
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• 1988

In order to study the marked variation of red blood cell sedimentation rate in some species of animals, the packed cell volume, volume percentage of erythrocytes in whole blood, was reshuffled of 20%, 40% and 60% using heteroplasma of chicken and goat, and the red blood cell sedimentation rate was measured in Westergren tubes at $27{\pm}1^{\circ}C$ and $8{\pm}1^{\circ}C$. The results obtained were summarized as follows: 1. The values of packed cell volume(PCV) of goat and chicken were $40.7{\pm}4.1%$ and $30.2{\pm}2.2%$ respectively. 2. The sedimentation rates of reshuffled red blood cell were settled faster at lower PCV than higher PCV, i.${\acute{e}}$. there was a reverse relationship between the sedimention rate and PCV. 3. Red blood cells of chicken settled quickly, where as those of goat settled very slowly. Chicken red blood cell sedimented rapidly even in goat plasma, and goat red blood cell sedimented slowly in chicken plasma. These findings indicate that the plasma is not the only factor determining the rapid red blood cell sedimentation rate of chicken. 4. The sedimentation rate of reshuffled red blood cell of chicken and goat were accelerated at higher temperature than lower temperature.

• 한국재료학회지
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• 제14권2호
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• pp.101-109
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• 2004

The influences of solidification rates and carbon contents on the formation of the $\delta$-ferrite were studied by directional solidification in modified 12%Cr-l %Mo steels. Directional solidification experimental results showed that solidification microstructure depended on solidification rate and carbon content and chromium equivalent. The length of the mushy zone increased and the dendrite arm spacings decreased as the solidification rate increased. The volume fraction of the 8-ferrite decreased with increasing the solidification rate and carbon content. The volume fraction of the ferrite showed much higher at low solidification rates with planar and cellular interfaces than that at high solidification rates with dendritic interface. It is expected that macro-segregation of C causes lower C content at the lower solidification fraction in the directionally solidified sample, where lower C results in higher volume fraction of the ferrite. In order to estimate solidification microstructure in modified 12Cr-l%Mo steels, various solidification conditions, such as solidification rate, cooling rate, segregation, alloy composition, should be considered.

• 한국산학기술학회논문지
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• 제5권6호
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• pp.580-587
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• 2004

본 논문의 목적은 주가지수 선물시장에서 선물의 가격과 거래량간 관계를 분석하는 것이다. 이를 위하여 선물수익률과 거래량 변화율을 이용하여 거래량과 선물가격간의 관계를 분석하였다. 거래량 변화율과 선물수익률간의 관계를 검증하기에 앞서 각각의 시계열에 대한 안정성 검증을 실시한 결과, 거래량 변화율과 선물수익률은 모두 안정적인 시계열인 것으로 나타났다. VAR모형을 이용한 선물수익률과 거래량 변화율간 관계에 대한 분석결과, 기간별 분석결과에서는 전체기간에서 주가지수 선물수익률이 거래량 변화율을 -3차에서 강하게 선도하는 것으로 나타났으며, 선물시장의 추세에 따른 분석결과는 선물가격의 상승시에는 거래량 변화율이 선물수익률을 선도하는 반면, 선물가격이 하락하는 경우는 선물수익률이 거래량을 선도하는 것으로 나타나고 있다. 또한, 상승기에 거래량변화율이 선물수익률을 선도하는 정도보다는 하락기에 선물수익률이 거래량 변화율을 선도하는 계수의 크기가 크게 나타나고 있다.

• Korean Journal of Radiology
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• 제25권2호
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• pp.199-209
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• 2024

Objective: This study aimed to compare therapeutic efficacy and technical outcomes between adjustable electrode (AE) and conventional fixed electrode (FE) for radiofrequency ablation (RFA) of benign thyroid nodules. Materials and Methods: Between 2013 and 2021, RFA was performed on histologically proven benign thyroid nodules. For the AE method, AE length ≥ 1 cm with higher power and < 1 cm with lower power were utilized for ablating feeding vessels and nodules, especially those near anatomical structures, respectively. The therapeutic efficacy (volume reduction rate [VRR], complication rate, and regrowth rate) and technical outcomes (total energy delivery, ablated volume/energy, RFA time, and ablated volume/time) of FE and AE were compared. Continuous parameters were compared using a two-sample t-test or Mann-Whitney U test, and categorical parameters were compared using a chi-squared test or Fisher's exact test. Results: A total of 182 nodules (FE: 92 vs. AE: 90) in 173 patients (mean age ± standard deviation, 47.0 ± 14.7 years; female, 90.8% [157/173]; median follow-up, 726 days [interquartile range, 441-1075 days]) were analyzed. The therapeutic efficacy was comparable, whereas technical outcomes were more favorable for AE. Both electrodes demonstrated comparable overall median VRR (FE: 92.4% vs. AE: 84.9%, P = 0.240) without immediate major complications. Overall regrowth rates were comparable between the two groups (FE: 2.2% [2/90] vs. AE: 1.1% [1/90], P > 0.99). AE demonstrated a shorter median RFA time (FE: 811 vs. AE: 627 seconds, P = 0.009). Both delivered comparable median energy (FE: 42.8 vs. AE: 29.2 kJ, P = 0.069), but AE demonstrated higher median ablated volume/energy and median ablated volume/time (FE: 0.2 vs. AE: 0.3 cc/kJ, P < 0.001; and FE: 0.7 vs. AE: 1.0 cc/min, P < 0.001, respectively). Conclusion: Therapeutic efficacy between FE and AE was comparable. AE demonstrated better technical outcomes than FE in terms of RFA time, ablated volume/energy, and ablated volume/time.