• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2006년도 총회 및 춘계학술발표회
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• pp.383-386
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• 2006

Subsurface temperature is affected by heat advection due to groundwater advection. Temperature-depth profile can be perturbed especially when there are significant vertical groundwater flux caused by external force such as injection or extraction. This research is to clarify the change of subsurface temperature distribution when the 40m x l0m sandy aquifer is stimulated by two different vertical flux($case1:\;{\pm}10^{-5}m^3/s,\;case2:\;{\pm}4{\times}10^{-5}m^3/s$) using a program called HydroGeoSphere. The resulting temperature distribution contour map shows pumping causes vertical attraction of water from deeper and warmer place which result in rising up isotherm. Additionally more injection/extraction rate, more vertical groundwater flux leads to faster Increase in temperature near the pumping well.

• 대한기계학회논문집A
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• 제20권10호
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• pp.3142-3151
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• 1996

As plastics shrink when changing from a molten to a solid state, mold cavities must by made larger than the product specification, In making molded gears, the teeth in the cavity must be carefully compensated for shrinkage so that the teeth of gears will have the correct profile. Two compensation methods are widely used in the cavity design. One is the compensation of a module and the other is the modification of a pressure angle and profile shifting coefficient. These methods, however, do not provide a gear cavity with all disign parameters for gears and several parameters are determined by experience. In this paper, the new design technique, namely the compensation method of design parameters, was proposed , which is based on the three kinds of shrinkage rates obtained from the measuring data of the prototype of molded gears. Using the shrinkage rates in the tip circle, tooth heigth and tooth thickness, we calculate the whole design parameters of a gear cavity. Thus, the gear cavity is considered as a complete gear with the compensated module, pressure angle, profile shifting coefficient, clearance coefficient and back lash amount so that the formula of gears can be applied to the cavity design effectively. Experimental results show that more precision molded gears can be made by using the proposed design method.

• Journal of Pharmaceutical Investigation
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• 제24권4호
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• pp.227-231
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• 1994

The stability of red ginseng saponin in aqueous solution was studied with the acceleration test method. The degradation rate constant of ginsenoside Rb1, an index component of red ginseng saponin, was $2.371{\times}10^{-4}\;day^{-1}$ at $20^{\circ}C$, and the shelf-life was about 570 days. The pH-rate profile demonstrated that the most stable range was pH 6-8. Mannitol and benzyl alcohol, common excipients for injection, exerted no influence on the degradation reaction of ginsenoside Rb1.

• Journal of Pharmaceutical Investigation
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• 제38권1호
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• pp.63-72
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• 2008

Meloxicam-loaded microspheres were prepared with poly(D,L-lactic acid)(PLA) by a solvent-emulsion evaporation method. The morphology, particle size, drug loading capacity, drug entrapment efficiency (EE) and release patterns of drug were investigated in vitro. Various batches of micro spheres with different size and drug content were obtained by changing the ratio of meloxicam to $PLA^{\circ}{\AE}s$ with different molecular weight, PLA concentration in the dispersed phase and stirring rate. Meloxicam crystals on microsphere surface, which were released rapidly and could act as a loading dose, were observed with increasing drug content. The release rate was increased with increase in drug contents and decrease in the molecular weight of PLA. Microspheres prepared with smaller molecular weight produced faster drug release rate. The release rate of meloxicam for long-acting injectable delivery system in vitro, which would aid in predicting in vivo release profile, could be controlled by properly optimizing various factors affecting characteristics of microspheres. Blood concentration-time profile of meloxicam after intramuscular injection of meloxicam-loaded microspheres in rabbits showed possibility of long term application of this system in clinical settings.

• 한국화재소방학회논문지
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• 제26권2호
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• pp.53-58
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• 2012

본 연구에서는 가연성 물질을 고려한 워터커튼 시스템(Water Curtain System)의 열 및 연기유동 제어 특성을 실험적으로 분석하였다. 이를 위해서 Room Corner Tester(RCT)를 사용하여 연료의 종류가 소나무(PineWood)와 가솔린(Gasoline)인 경우 각각의 발열량(Heat Release Rate)을 구하였으며, 워터커튼용 화재실험 장치를 제작하여 화원근방에서 5m 떨어진 지점의 천장 부근에 분사각도 $180^{\circ}$, 오리피스 직경 8.2 mm의 노즐(Nozzle)을 설치한 후 목재와 가솔린 각각에 대해서 화재실험을 실시하여 워터커튼 전후의 온도분포와 가시도를 측정하였다. 그결과 워터커튼 시스템의열및연기유동 제어는 가연성 물질의 연소특성에 따른 고온의 연기발생량과 분사 노즐에 의한 유동현상이 중요한 상관관계를 갖고 있음을 확인하였다.

• Clinical and Experimental Reproductive Medicine
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• 제49권2호
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• pp.135-141
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• 2022

Objective: This study investigated the impact of two stimulation protocols using highly purified human menopausal gonadotropin (HP-hMG) on the endocrine profile, follicular fluid soluble Fas levels, and outcomes of intracytoplasmic sperm injection (ICSI) cycles. Methods: This prospective clinical trial included 100 normal-responder women undergoing ovarian stimulation for ICSI; 55 patients received concomitant follicle-stimulating hormone (FSH) plus HP-hMG from the start of stimulation, while 45 patients received FSH followed by HP-hMG during mid/late follicular stimulation. The primary outcome was the number of top-quality embryos. The secondary outcomes were the number and percentage of metaphase II (MII) oocytes and the clinical pregnancy rate. Results: The number of MII oocytes was significantly higher in the concomitant protocol (median, 13.0; interquartile range [IQR], 8.5-18.0 vs. 9.0 [8.0-13.0] in the consecutive protocol; p=0.009); however, the percentage of MII oocytes and the fertilization rate were significantly higher in the consecutive protocol (median, 90.91; IQR, 80.0-100.0 vs. 83.33 [75.0-93.8]; p=0.034 and median, 86.67; IQR, 76.9-100.0 vs. 77.78 [66.7-89.9]; p=0.028, respectively). No significant between-group differences were found in top-quality embryos (p=0.693) or the clinical pregnancy rate (65.9% vs. 61.8% in the consecutive vs. concomitant protocol, respectively). The median follicular fluid soluble Fas antigen level was significantly higher in the concomitant protocol (9,731.0 pg/mL; IQR, 6,004.5-10,807.6 vs. 6,350.2 pg/mL; IQR, 4,382.4-9,418.4; p=0.021). Conclusion: Personalized controlled ovarian stimulation using HP-hMG during the late follicular phase led to a significantly lower response, but did not affect the quality of ICSI.

• Environmental Engineering Research
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• 제11권5호
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• pp.241-249
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• 2006

A mathematical model is described for the prediction of convective upward transport of an organic solvent driven by evaporation at the surface, which is known as the major transport mechanism in the in-situ photolysis of a soil contaminated with 2,3,7,8-tetrachlorodibenzo-p-dioxin(TCDD). A finite-element model was proposed to incorporate the effects of multiphase flow on the distribution of each fluid, gravity as a driving force, and the use of hysteretic models for more accurate description of k-S-p relations. Extensive numerical calculations were performed to study fluid flow through three types of soils under different water table conditions. Predictions of relative permeability-saturation-pressure (k-S-p) relations and fluids distribution for an illustrative soil indicate that hysteresis effects may be quite substantial. This result emphasizes the need to use hysteretic models in performing flow simulations including reversals of flow paths. Results of additional calculations accounting for hysteresis on the one-dimensional unsaturated soil columns show that gravity affects significantly on the flow of each fluid during gravity drainage, solvent injection, and evaporation, especially for highly permeable soils. The rate and duration of solvent injection also have a profound influence on the fluid saturation profile and the amount of evaporated solvent. Key factors influencing water drainage and solvent evaporation in soils also include hydraulic conductivity and water table configuration.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2005년도 후기학술대회논문집
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• pp.13-14
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• 2005

Multi-dimensional combustion analysis and experiment has been carried out to investigate the effects of the injector nozzle hole diameter and number on the NOx formation and fuel consumption in HYUNDAI HiMSEN engine. The behavior of spray and combustion phenomena in diesel engine was examined by FIRE code. Wave breakup and Zeldovich models were adopted to describe the atomization characteristics and NOx formation. Wallfilm model suggested by Mundo, et al. and auto-ignition model suggested by Theobald and Cheng were adopted to investigate the spray-wall interaction characteristics and ignition delay. The information of spray angle and spray tip penetration length was extracted from fuel spray visualization experiment and the fuel injection rate profile was extracted from fuel injection system experiment as an input and verification data for the combustion analysis. Next, the nine different nozzle configurations were simulated to evaluate the effect of injector hole diameter and number on the NOx formation and fuel consumption.

• Archives of Pharmacal Research
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• 제28권9호
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• pp.1092-1096
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• 2005

Huperzine A-loaded microspheres composed of poly(D,L-lactide-co-glycolide) were prepared by an O/w emulsion solvent evaporation method. The characterization of the microspheres such as drug loading, size, shape and release profile was described. The in vitro release in the initial 7 days was nearly linear with $10\%$ released per day. Thereafter drug release rate became slow gradually and about $90\%$ drug released at day 21. The in vitro release rate determined by dialysis bag method had a good correlation with the in vivo release rate. Huperzine A aqueous solution was intramuscularly injected (i.m.) at 0.4mg/kg and microspheres were intra­muscularly injected at 8.4 mg eq huperzine A/kg in rats. The maxium plasma concentration $(C_{max})$ after i.m. microspheres was only $32\%$ of that after i.m. solution. Drug in plasma could be detectd until day 14 and about $5\%$ of administered dose was residued at the injection site at day 14. The relative bioavailability of huperzine A microspheres over a period of 14 days was $94.7\%$. Inhibition of acyecholinesterase activity (AchE) in rat's cortex, hippocampus and striatum could sustain for about 14 days. In conclusion, huperzine A-loaded microspheres possessed a prolonged and complete drug release with significant inhibition of AchE for 2 weeks in rats.

• 태양에너지
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• 제7권2호
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• pp.37-53
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• 1987

This study has been prepared for the purpose of developing the system performance prediction method of natural circulation solar hot water system. The storage tank of the natural circulation solar hot water system equipped with flat-plate solar collector is located at higher elevation than the solar collectors. Therefor, the storage tank temperature distribution formed accordance with configuration of storage tank by flow rate of circulating fluid affect system collection efficiency. In this study measure the storage tank temperature distribution with various experimental system under real sun condition and present the theoretical prediction method of the storage tank temperature. Moreover measure the flow rate not only day-time but also night-time reverse flow rate with die injection visual flow meter. Main conclusion obtain from the present study is as follows; 1) The storage tank temperature distribution above the connecting pipe connection position is the same as that of the fully mixed tank and below the connection position is the same as that of stratified tank. 2) The system performance sensitive to the storage tank temperature distribution. Therefore detailed tank model is necessary. Average storage tank temperature can be calculate 3% and storage tank temperature profile can get less than 10% difference with this model system.