• Journal of Life Science
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• v.17 no.10
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• pp.1321-1329
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• 2007

Deer antler tissue contains the most rapidly growing bone in the animal kingdom. Thus, it is likely that growing antler tissue is a rich source of local paracrine bone-stimulating factors. Growth factors, at least the insulin-like growth factor (IGF), control the bone-remodelling process. In this study, we tried to isolate and purify IGF-I from fresh antler tissue by the routine isolation and purification of protein. The purification involved ammonium sulfate precipitation, DEAE-Sepharose CL-60 ion-exchange chromatography, CM-Sepharose CL-6B ion-exchange chromatography, and Sephadex G-50 chromatography. Purified fractions from each step were analyzed by high-performance liquid chromatography (HPLC), SDS polyacrylamide gel electrophoresis (SDS-PACE), Dot-blot, and Western-blot methods. Furthermore, the quantification of partially purified IGF-I was calculated by enzyme-linked immunosorbent assays (ELISA) using antibody to human recombinant IGF-1. SDS-PAGE analysis of the final fraction yielded two molecular bands and the signal band was at 12 kDa on the Western-blot film. This purified IGF-I fraction showed a peak at retention time of eight min. The quantity of IGF-I in 20 g deer antler tissue as starting weight was calculated using a standard curve to be 2910 ng/ml, and total IGF-I amount is 0.291 g. The results show that IGF-I, which can be found in deer antler, can be partially purified and quantified by classic protein isolation methods.

• Journal of the Korea Concrete Institute
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• v.17 no.2 s.86
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• pp.263-271
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• 2005

HPFRCC(High Performance Fiber Reinforced Cementitious Composite) is a class of FRCCs(Fiber Reinforced Cementitious Composites) that exhibit multiple cracking. Multiple cracking leads to improvement in properties such as ductility, toughness, fracture energy, strain hardening, strain capacity, and deformation capacity under tension, compression, and bending. These improved properties of HPFRCCs have triggered unique and versatile structural applications, including damage reduction, damage tolerance, energy absorption, crack distribution, deformation compatibility, and delamination resistance. These mechanical properties of HPFRCCs become different from the kinds and shapes of used fiber, and it is known that the effective size of fiber in macro crack is different from that in micro crack. This paper reports an experimental findings on the mechanical properties of HPFRCCs reinforced with the micro fiber(PP50, PVA100 and PVA200) and macro fiber(PVA660, SF500). Uniaxial compressive tests and three point bending tests are carried out in order to compare with the mechanical properties of HPFRCCs reinforced with micro fibers or hybrid fibers such as compressive strength, ultimate bending stress, toughness, deformation capacity and crack pattern under bending, etc.,

• Journal of Pharmaceutical Investigation
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• v.34 no.4
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• pp.319-325
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• 2004

A bioequivalence of $Etodol^{TM}$ tablets (Yuhan corporation) and $Kuhnillodine^{TM}$ tablets (Kuhnil Pharm. Co., Ltd.) was evaluated according to the guideline of Korea Food and Drug Administration (KFDA). Single 200 mg dose of etodolac of each medicine was administered orally to 24 healthy male volunteers. This study was performed in a $2{\times}2$ crossover design. Concentrations of etodolac in human plasma were monitored by a high-performance liquid chromatography. $AUC_t$ (the area under the plasma concentration-time curve from time zero to 24 hr) was calculated by the linear trapezoidal rule method. $C_{max}$ (maximum plasma drug concentration) and $T_{max}$ (time to reach $C_{max}$) were compiled from the plasma concentration-time data. Analysis of variance was performed using logarithmically transformed $AUC_t$ and $C_{max}$. No significant sequence effect was found for all of the bioavailability parameters. The 90% confidence intervals of the $AUC_t$ ratio and the $C_{max}$ ratio for $Etodol^{TM}/Kuhnillodine^{TM}$ were 1.01-1.10 and 0.87-1.06, respectively. This study demonstrated a bioequivalence of $Etodol^{TM}$ and $Kuhnillodine^{TM}$ with respect to the rate and extent of absorption.

• Journal of Pharmaceutical Investigation
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• v.34 no.6
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• pp.505-511
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• 2004

A bioequivalence study of $Bestidine^{TM}$ tablets (Choong Wae Pharma. Corp., Korea) to Dong-A $Gaster^{TM}$ (Dong-A Pharmaceutical Co., Ltd., Korea) tablets was conducted according to the guidelines of Korea Food and Drug Administration (KFDA). Twenty four healthy male Korean volunteers received each medicine at the famotidine dose of 40 mg in a $2{\times}2$ crossover study. There was a one-week wash out period between the doses. Plasma concentrations of famotidine were monitored by a high-performance liquid chromatography for over a period of 12 hours after the administration. $AUC_t$ (the area under the plasma concentration-time curve from time zero to 12 hr) was calculated by the linear trapezoidal rule method. $C_{max}$ (maximum plasma drug concentration) and $T_{max}$ (time to reach $C_{max}$) were compiled from the plasma concentration-time data. Analysis of variance was carried out using logarithmically transformed $AUC_t$ and $C_{max}$. No significant sequence effect was found for all of the bioavailability parameters indicating that the crossover design was properly performed. The 90% confidence intervals of the $AUC_t$ ratio and the Cmax ratio for $Bestidine^{TM}/Gaster^{TM}$ were log 0.90-log 1.06 and log 0.98-log 1.20, respectively. These values were within the acceptable bioequivalence intervals of 0.80-1.25. Thus, our study demonstrated the bioequivalence of $Bestidine^{TM}$ and $Gaster^{TM}$ with respect to the rate and extent of absorption.

• Journal of Pharmaceutical Investigation
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• v.38 no.2
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• pp.135-142
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• 2008

The present study describes the evaluation of the bioequivalence of two atorvastatin tablets, Lipitor $Tablet^{(R)}$ (Pfizer, reference drug) and Atorva $Tablet^{(R)}$ (Yuhan, test drug), according to the guidelines of Korea Food and Drug Administration (KFDA). Forty-nine healthy male Korean volunteers received each medicine at the atorvastatin dose of 40 mg in a $2{\times}2$ crossover study with a two weeks washout interval. After drug administration, serial blood samples were collected at a specific time interval from 0-48 hours. The plasma atorvastatin concentrations were monitored by an high performance liquid chromatography -tandem mass spectrometer (LC-MS/MS) employing electrospray ionization technique and operating in multiple reaction monitoring (MRM) and positive ion mode. The total chromatographic run time was 4.5 min and calibration curves were linear over the concentration range of 0.1-100 ng/mL for atorvastatin. The method was validated for selectivity, sensitivity, linearity, accuracy and precision. $AUC_t$ (the area under the plasma concentration-time curve from time zero to 48hr) was calculated by the linear log trapezoidal rule method. $C_{max}$ (maximum plasma drug concentration) and $T_{max}$ (time to reach $C_{max}$) were complied trom the plasma concentration-time data. Analysis of variance was carried out using logarithmically transformed $AUC_t$ and $C_{max}$. No significant sequence effect was found for all of the bioavailability parameters indicating that the crossover design was properly performed. The 90% confidence intervals of the $AUC_t$ ratio and the $C_{max}$ ratio for Atorva $Tablet^{(R)}$ / Lipitor $Tablet^{(R)}$ were ${\log}\;0.9413{\sim}{\log}\;1.0179$ and ${\log}\;0.831{\sim}{\log}\;1.0569$, respectively. These values were within the acceptable bioequivalence intervals of ${\log}\;0.8{\sim}{\log}\;1.25$. Based on these statistical considerations, it was concluded that the test drug, Atorva $Tablet^{(R)}$ was bioequivalent to the reference drug, Lipitor $Tablet^{(R)}$.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.5
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• pp.3006-3013
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• 2015

Flat tube heat exchangers can improve the thermal performance significantly compared with round tube heat exchangers. For proper design of flat tube heat exchangers, one should know the tubeside heat transfer coefficients. In this study, convective boiling heat transfer coefficients of R-410A were obtained in a flat extruded aluminum tube with $D_h=1.41mm$. The test range covered mass flux from 200 to $600kg/m^2s$, heat flux from 5 to $15kW/m^2$ and saturation temperature from $5^{\circ}C$ to $15^{\circ}C$. The heat transfer coefficient curve shows a decreasing trend after a certain quality(critical quality). The critical quality decreases as the heat flux increases, and as the mass flux decreases. The early dryout at a high heat flux results in a unique 'cross-over' of the heat transfer coefficient curves. The heat transfer coefficient increases as the mass flux increases. At a low quality region, however, the effect of mass flux is not prominent. The heat transfer coefficient increases as the saturation temperature increases. The effect of saturation temperature, however, diminishes as the heat flux decreases. Both the Shah and the Kaew-On et al. correlations reasonably predicted the present data.

• Journal of the Korean Institute of Gas
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• v.20 no.1
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• pp.13-22
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• 2016

This paper presents development of an appropriate procedure and flow chart to analyze shale gas production data obtained from a multi-fractured horizontal well according to flow characteristics in order to calculate an estimated ultimate recovery. Also, the technical considerations were proposed when a rate transient analysis was performed with field production data occurred to only $1^{st}$ transient flow. If production data show the $1^{st}$ transient flow from log-log and square root time plot analysis, production forecasting must be performed by applying different method as before and after of the end of $1^{st}$ linear flow. It is estimated by an area of stimulated reservoir volume which can be calculated from analysis results of micro-seismic data. If there are no bottomhole pressure data or micro-seismic data, an empirical decline curve method can be used to forecast production performance. If production period is relatively short, an accuracy of production data analysis could be improved by analyzing except the early production data, if it is necessary, after evaluating appropriation with near well data. Also, because over- or under-estimation for stimulated reservoir volume could take place according to analysis method or analyzer's own mind, it is necessary to recalculate it with fracture modeling, reservoir simulation and rate transient analysis, if it is necessary, after adequacy evaluation for fracture stage, injection volume of fracture fluid and productivity of producers.

• Journal of Korean Society of Transportation
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• v.30 no.2
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• pp.43-52
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• 2012

A lane departure warning system (LDWS) is an effective technology-based countermeasure for preventing traffic crashes as it provides warning information to drivers. Understanding the characteristics of perception and satisfaction levels on LDWS is fundamental for deriving better performance and functionality enhancements of the system. The purpose of this study is to evaluate the user satisfaction of LDWS. A survey to collect user perception and user preference data was conducted. Both cross-tabulation analysis and binary logistic regression technique were adopted to identify the factors affecting user satisfaction for LDWS. The results revealed that the accuracy and timeliness of warning information was significant for evaluating the effectiveness of LDWS. In particular, the warning accuracy at a curve segment on the road was the most dominant factor affecting user satisfaction. The outcome of this study would be valuable in evaluating and designing LDWS functionalities.

• Journal of Veterinary Clinics
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• v.24 no.3
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• pp.308-311
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• 2007

A study on the oral bioavailability and pharmacokinetics of an anticoccidal agent, toltrazuril, was conducted in broilers following a single oral doses of 10 mg/kg body weight (BW) or 40 mg/kg BW. The concentrations of toltrazuril in plasma were determined by a high-performance liquid chromatography/mass spectrometry. Plasma concentration-time data after single oral administration were analyzed by a non-compartmental analysis. Toltrazuril was very well-absorbed through the gastrointestinal tract with $C_{max}$ of $18.04{\pm}5.80{\mu}g/mL$ and $47.15{\pm}9.40{\mu]g/mL$ at $4.33{\pm}1.51h$ and $3.67{\pm}1.15h$ after oral dose of 10 mg/kg and 40 mg/kg in broilers, respectively. A comparison between 10 mg/kg and 40 mg/kg dose groups showed that $t_{max}$ were similar while $C_{max}$ and area under curve (AUC) increased with increasing dose.

• Korean Journal of Materials Research
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• v.10 no.10
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• pp.703-708
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• 2000

As the engine design changes to get high efficiency and performance of commercial diesel engine, surface w wear of the earn follower becomes an important issue as applied load increasing at the contact face between cam follower and cam. We developed the ceramic cam follower made of sili$\infty$n nitride ceramic which was more wear resistant than the cast iron or sintered metal cam follower. Ceramic cam follower was made by direct brazing of thin ceramic disk to steel body using an active brazing alloy without the interlayer. In-situ crowning(R), resulted from the difference of thermal expansion coefficient between ceramic and carbon steel after direct brazing without any stress-relieving inter]ayer, could be controlled. When a earbon steel was heated above $A_{c1}$ point and then c$\infty$led, the expansion curve represented a hysteresis. Appropriate crowning was achieved below the $A_{c1}$ point(about $723^{\circ}C$) and crowning increased with brazing temperature exponentially above the $A_{c1}$ point. Optimum brazing temperature range was from 700 to $720^{\circ}C$. We developed successfully the ceramic cam follower having appropriate crowning and being inexpensive. Also we could successfully control the crowning of ceramic earn follower by hysteresis behavior of thermal expansion of earbon steel during direct brazing process.