• Journal of Energy Engineering
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• v.10 no.4
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• pp.357-362
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• 2001

A bench type ammonia-water absorber heat exchange cycle was tested by varying the system charging concentration, refrigerating valve opening and weak solution flow rate. It was observed that the cooling capacity was increased as the system charging concentration was increased. Optimum system charging concentration was found for the coolong capacity of the system. The opening rate of refrigerant expansion valve had a direct influence on the refrigerant sub-cooling at the condenser outlet. Optimum sub-cooling was found to be 0~4$^{\circ}C$. As the weak solution flow rate increased the concentration of strong solution and the evaporating pressure decreased. There existed a optimum weak solution flow rate which maximized the cooling capacity and COP.

• Korean Journal of Animal Reproduction
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• v.20 no.4
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• pp.433-441
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• 1997

체외성숙과 수정된 돼지 난자의 체외발달능이 체외배발생 배양액인 NCSU 배양액에 0.4% BSA, 10% 혈청 혹은 아미노산(2% BME 아미노산 용액과 1% MEM 아미노산 용액)을 첨가함으로써 조사되었다. 본 실험에 공시된 난자는 체외수정 후 30시간 (2-세포기) 혹은 48시간 (2~4-세포기)에 회수하였다. 실험 I에서 0.4% BSA가 첨가된 NCSU 배양액에서 2-세포기 난자들의 배양경과시간에 따른 발달능을 조사한 결과, 배양 후 72시간 (체외수정 후 102 시간)에 상실배와 배반포기가 나타났으며, 배양 후 120시간째(체외수정 후 150시간)에도 팽창된 배반포까지만 발달하였다. 실험 II는 체외수정 후 48시간의 분할된(2~8-세포기) 난자들의 핵과 외관적 분할구와의 수적 차이를 조사한 결과, 2~4-세포기보다는 5-세포기 이상에서 핵과 분할구의 조화에 차이가 많았다. 실험III에서는 BSA, 혈청 혹은 아미노산이 첨가 혹은 무첨가된 배양액내에서 2~4-세포기 난자들의 배반포 후 부화능력을 조사한 결과, 모든 군에 있는 난자들은 팽창된 배반포까지 발달할 수 있었던 반면, 난자의 부화는 아미노산 혹은 혈청이 포함된 배양액에서만 일어났다. 더욱이 상실배와 배반포시기에 혈청의 첨가는 부화 배반포기 배의 발달을 현저히 증가시켰다. 이상의 결과로 미루어 볼 때, 배양액내에 대한 아미노산과 혈청의 첨가는 돼지 배반포의 부화를 유도할 수 있다고 본다.

• Journal of the Society of Disaster Information
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• v.13 no.1
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• pp.43-50
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• 2017

In this study, to investigate the strength enhancement and stress transfer effect of the inflatable chemicals used in the recovery of soft ground or partial settlement, the dilatant solution was prepared and classified by measuring the density and the earth pressure in the sand ground. The inflation reinforcing agent was prepared by injecting into a separate impervious vacuum sheet by dividing into a relatively high expansion group and a low expansion group, and a cementation experiment was performed in the lower part of the homogeneously formed model ground. As a result, reinforcing effect was shown up to about 15cm above the expansion reinforcement, and the soil pressure showed a compaction tendency similar to the concentrated load of $1.150{\sim}11.298t/m^2$.

• Clinical and Experimental Reproductive Medicine
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• v.24 no.2
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• pp.241-251
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• 1997

체외성숙과 수정된 돼지 난자의 체외발달능이 체외배발생 배양액인 NCSU 배양액에 0.4% BSA, 10% 혈청 혹은 아미노산 (2% BME 아미노산 용액과 1% MEM 아미노산 용액)을 첨가함으로서 조사되었다. 본 실험에 공시된 난자는 체외수정 추 30시간 (2-세포기)혹은 48 시간 ($2{\sim}4$-세포기)에 회수하였다. 실험I에서 0.4% BSA가 첨가된 NCSU 배양액에서 2-세포기 난자들의 배양경과시간에 따른 발달능을 조사한 결과, 배양 후 72 시간 (체외수정 후 102 시간)에 상실배기와 배반포기 배가 나타났으며, 배양 후 120 시간째 (체외수정 후 150 시간)에도 팽창된 배반포기 배까지만 발달하였다. 실험II는 체외수정 후 48 시간의 분할된 ($2{\sim}8$-세포기) 난자들의 핵과 외관적 분할구와의 수적 차이를 조사한 결과, $2{\sim}4$-세포기보다는 5-세포기 이상에서 핵과 분할구의 조화에 차이가 많았다. 실험III에서는 $2{\sim}4$-세포기 난자들을 배양후 5일째의 배반포들의 투명대의 두께, 난자 크기 그리고 inner cell mass (ICM)과 trophectoderm (TE)의 세포 배열을 조사한 결과, 난자의 크기가 커짐에 따라서 투명대가 얇아지고 전체 세포수가 증가하였지만, ICM의 비율은 차이가 없었다. 실험IV에서는 BSA, 혈청 혹은 아미노산이 첨가 혹은 무첨가된 배양액내에서 $2{\sim}4$-세포기 난자들의 배반포 후 부화능력을 조사한 결과, 모든 군에 있는 난자들은 팽창된 배반포기 배까지 발달할 수 있었던 반면, 난자의 부화는 아미노산 혹은 혈청이 포함된 배양액에서만 일어났다. 더우기 상실배기와 배반포기 시기에 혈청의 첨가는 부화 배반포기 배의 발달을 현저히 증가시켰다. 또한 아미노산과 혈청의 영향을 받은 팽창 배반포기 배는 얇은 투명대, 팽창된 난자의 크기 그리고 ICM과 전체 세포수의 증가를 보였다. 이상의 결과로 미루어 볼때, 배양액내에 대한 아미노산과 혈청의 첨가는 돼지 배반포기 배의 부화를 유도할 수 있다고 보며, 더우기 이들 요소들은 투명대의 두께, 난자의 크기 그리고 ICM과 전체 세포수에 영향을 미친다.

• Journal of the Korean Institute of Gas
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• v.19 no.5
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• pp.98-103
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• 2015

Liquefied petroleum gas can be charged up to 85% of cylinder volume by enforcement regulations of safety control and business of liquefied petroleum gas act. The charged mass by enforcement regulations is considered by liquid expansion of internal liquefied petroleum gas at $65^{\circ}C$. But the temperature of liquid would not be suspended under $65^{\circ}C$ in a cylinder or portable vessel at certain situation. In the thermodynamics view point, the cylinder can be exposed to high pressure by liquid expansion. Consequently, it can be possible to potential risk such as physical explosion. Hence, this paper will offer a method of estimated internal pressure by liquid expansion at critical state in the closed system. Also, the structural factor which is given rise to volume increasement of cylinder is offered by experiment. This paper is expected as crucial reference for a cylinder design of liquefied petroleum gas.

• Korean Journal of Animal Reproduction
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• v.21 no.2
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• pp.131-137
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• 1997

This study was carried out to investigate the in vivo development rates of vitrified-thawed mouse expanding, hatching and hatched blastoc ysts(BL). In vitro fertilization produced blastocysts were vitrified in EFS40(40% ethylene glycol, 30% Ficoll and 0.3 M sucrose in phosphate buffer saline containing 10% FBS). Expanding a and hatching blastocysts were equilibrated in 20% ethylene glyco](EG) for 5 min. before exposure to EFS40 at 25°C for 1 min., they were then vitrified in liquid nitrogen. Hatched blastocysts which cultured in m-CR1 medium supple mented 0.4% bovine serum albumin on day 5. were equilibrated in 10% EG for 5 min. and then vitrified in EFS40 for 30 sec. After thawing, re-expanding blastocysts were transferred to recipients(3 day of pseudopregnant) on one or both uterine horns(6-8 embryos per a horn). Preg¬n nancy rates of recipients and implantation were a assccessed by autopsy on 15 gestation. The res¬u ults obtained in these experiments were summar¬1 ized as follows; 1) The pregnancy and live fetus rates, for vitrified expanding BL(77.8 and 25.0%) and hatching BL(77.8 and 26.4%)n vitro were not significantly difference in those of control BL (66.7 and 42.9%: 83.3 and 40.4%), respectively, 2) in vitro development of vitrified hatched BL was 34.0%. and 3) in vivo developmental rate of vitrified hatched BL was only 33.3%. These results suggested that proposed rapid vitrification p procedures used EFS40 cryoprotectant can be effectively performed in mouse expanding Ihatching blastocysts and that mouse blastocysts a after being hatched from zona pellucida can be successfully cryopreserved.

• Clinical and Experimental Reproductive Medicine
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• v.26 no.2
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• pp.231-238
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• 1999

The objective of this study was to examine the effect of developmental stage and embryo age of in vitro produced bovine blastocysts after vitrification and thawing. In vitro cultured day 8 blastocysts after IVF were equilibrated 20% ethylene glycol (EG) for 3 min. and were vitrified using EFS40, which is consisted of 40% EG, 18% ficoll, 0.3M sucrose and 10% FBS added in mDPBS for 30 sec. before being plunged into $LN_2$. Also, survival in vitro was assessed by re-expansion and hatching or hatched at 24 hand 48 h postwarming, respectively. The results obtained in these experiments were summarized as follows; 1) When the embryos were cultured for 8 day after IVF, 41.0% of the cleaved embryos developed to the blastocysts (early; 7.6%, expanded; 22.9%, hatching; 4.6% and hatched; 5.9%). 2) When the embryos were exposed or vitrified to the freezing solution, the re-expansion of vitrified embryos (73.3%) was significantly lower than that of control and exposed embryos (100, 97.0%) (p<0.05). But the formation rate of hatching or hatched blastocysts of vitrified embryos (66.7, 46.7%) at 48h after thawing was similar to that of exposed embryos (66.7, 39.4%) but not control (100, 100%) (p<0.01). However, in the total cell numbers of those developed hatched blastocysts, there were not significantly different among the treatment groups. 3) When the embryo survival rates by different developmental stage were examined, the re-expansion was not different among the groups $(64.5{\sim}75.6%)$. After warming 48 h, the hatching and hatched formation of early blastocysts (25.8, 9.7%) was significantly lower than those of expanded (69.7, 39.4%) and hatching blastocysts (53.3, 43.3%) (p<0.05). 4) In addition, when the expanded blastocysts at day 7, 8 and 9 were vitrified, the re-expansion of day 8 and 9 embryos was significantly lower than that of day 7 (day 7; 93.9%, day 8; 75.8% and day 9; 87.5%) (p<0.05). However, the rates of development to hatched blastocysts were no difference among the groups (day 7; 36.4%, day 8; 36.4% and day 9; 31.3%). These results suggested that in vitro produced expanded or hatching blastocysts can be efficiently cryopreserved by the two-step vitrification method using EFS40.

• Journal of the Korean Society of Radiology
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• v.84 no.4
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• pp.911-922
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• 2023

Purpose To compare small bowel distension and side effects between a diluted polyethylene glycol (PEG) solution and a low-density (0.1% w/v) barium sulfate suspension (LDBSS) for CT enterography (CTE) preparation. Materials and Methods Total 173 consecutive patients who underwent CTE were enrolled in this study. The LDBSS (1 L) was used in 50 patients, and the diluted iso-osmotic PEG solution (1 L) was used in 123 patients. Two blinded radiologists independently scored jejunal and ileal distensions on a 5-point scale. To compare side effects between the two groups, the patients reported whether they had immediate complications after the administration of the oral contrast media. Results For ileal and jejunal distension, the diluted PEG solution showed no difference from the LDBSS for either reader (ileum: reader 1, median, 4; 4, interquartile range, 3-4; 3-4, p = 0.997; reader 2, median, 4; 4, interquartile range, 3.3-4.0; 3-4, p = 0.064; jejunum: reader 1, median, 2; 2, interquartile range, 2-3; 2-3, p = 0.560; reader 2, median, 3; 2, interquartile range, 2-3; 2-3, p = 0.192). None of the patients complained of immediate complications following administration of either of the oral contrast media. Conclusion The diluted PEG solution showed comparable bowel distension compared to LDBSS and no immediate side effects; thus, it can be a useful alternative.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.11a
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• pp.147-147
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• 2003

탄소/탄소 복합체의 내산화 코팅을 위하여 산화티탄, 산화알루미늄, 산화이트륨 등을 포함하는 여러 가지 인산염계 유리를 제조하였다. 유리 산화물조성 몰비는 인산에 대하여 인산알루미늄을 15몰%, 30몰%, 45몰%로 하였고 산화티탄은 70몰%, 산화 이트륨은 25몰%이 되도록 코팅 액을 제조하였다. 제조 된 코팅액은 석영 도가니에서 열처리 하여 급냉 시켰으며, 급냉 시키고 다시 130$0^{\circ}C$, 1시간 동안 열처리하여 유리를 제조하였다. 제조된 유리의 열중량, 열팽창율, 열전도도를 분석하여 탄소 복합체와의 적합성을 조사하고, 내산화성 시험을 위해 탄소/탄소 복합체에 코팅액을 도포하여 산화 감량 비율을 측정하였다. 엑스선 회절분석기와 적외선 분광기를 통하여 인산염 유리의 구조분석을 실시하고 비커스 미세 경도 시험기를 이용하여 기계적 물성을 측정하였다.

• Journal of the Korean Institute of Gas
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• v.11 no.1 s.34
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• pp.46-50
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• 2007

The metering systems in LPG vaporizers have been frequently exposed to severe conditions and resulted in many problems such as gauge malfunctioning and rupturing if the check-floaters fail to stop liquid outflow when the heat supply for the vaporization of LPG is interrupted. Therefore, to analysis the vaporizer system we carried out the vaporizer performance test and float bulb test by newly devised test equipments. Consequently, we determined the specific gravity of the float bulb and reasonable operating temperature ranges for the LPG and heating waters.