• 태양에너지
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• 제9권2호
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• pp.31-41
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• 1989

The purpose of this research is to study the utility of prediction program like a F.E.M. analysis for energy recovery of heat exchanger with heat pipe which uses arbitrary groove wick. The program is based on the utility by the experimental and applytical method of the single heat pipe. It is also expanded and applied in the prediction program of the heat exchanger. The results are as follows; 1) The effective thermal conductivity of the groove wick with arbitrary shape is counted by the thermal resistance change. 2) The more the number of rows, the more the effect energy recovery changing by the number of rows, the bigger the free velocity, the smaller the effect of energy recovery. 3) The effect of energy recovery increases according to the value of the rate of mass flow (Me/Mc) and also number of rows. 4) The comparison between calculated and data shows good agreement within 2.5% error, therefore the F.E.M. analysis of the study is useful to predict the performance of heat pipe-heat exchanger.

• 한국동물위생학회지
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• 제27권1호
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• pp.17-29
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• 2004

A multiresidual analysis was performed to determine 12 sulfonamides(sulfacetamide, sulfadiazine, sulfisomidine, sulfathiazole, sulfapyridine, sulfamerazine, sulfamethazine, sulfamonomethoxine, sulfisoxazole, sulfamethoxazole, sulfaquinoxaline, and sulfadimethoxine) in beef and pork simultaneously. The multiresidual analysis for the sulfonamides currently used was able to analyze 5 kinds of sulfonamides at the same time. The method of this 12 sulfonamides multiresidual analysis in this study was matrix solid-phase dispersion(MSPD) by high performance liquid chromatography (HPLC) and liquid chromatography mass spectrometry (LC/MS). The recovery rate of the materials was measured by MSPD method with 3 different extraction solvents; Dichloromethane, DCM: Ethylacetate(3:1), DCM:EA(9:1). Also, samples (84 beef and 205 pork samples) which were positive by EEC-4 plate test from 2001 to 2003 were tested to investigate the kinds of sulfonamides using HPLC. The results from the study were as follows; 1. The recovery rate of the materials was measured by MSPD method with 3 different extraction solvents; Dichloromethane, DCM:Ethylacetate(3:1), DCM:EA(9:1). The method of extraction solvent with DCM:ethyl acetate(9:1) was the most excellent(87.7∼99.3%) in separation and reappearance. 2. In the LC/MS analysis. of sulfonamides, signal to noise ratio was showed relatively high in the positive mode and special ion in the quality analysis was determined via [M+H]$\^$+/ and m/z 156. A spectrum of sulfonamides was showed from all 12 sulfonamides. 3. The samples positive by the EEC-4 plate, a screening test method, were categorized by sulfonamides through Charm II and confirmed the kinds of sulfonamides through HPLC. 1) Among 84 beef samples positive by EEC-4 plate, 20 samples were positive by Charm II and identified as 7 sulfamethazine, 9 sulfadimethoxine, 1 sulfamonomethoxine and 3 unknown status. 2) Among 205 pork samples positive by EEC-4 plate, 42 samples were positive by Charm II and identified as 19 sulfamethazine, 1 sulfadimethoxine, 4 sulfamonomethoxine and 5 unknown status.

• KSBB Journal
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• 제14권5호
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• pp.539-542
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• 1999

의 대량생산과 분리.정제 기술의 개발을 위해 Arthrobacter ureafaciens KCTC 3387 균주를 이용한 발효 및 분리정제된 효소반응을 통한 DFAIII의 생산과 회수에 대하여 조사하였다. 첫 번째 방법으로는 Arthrobacter ureafaciens 균주를 발효배양하여 DFAIII 양이 최고가 되는 시점에서 발효정지 시킨후 silica gel를 통해 gel filtration을 분리하였고, 두 번째 방법으로는 정제된 효소로 반응시킨 다음 silica gel을 통해 gel filtration을 하여 분리하였으며, 세 번째 방법으로는 발효배양상등액에 에탄올을 첨가하여 생산물을 침전시켜 DFAIII를 분리하였다. 25 g/L의 초기 inulin 농도로부터 각각 1.57, 4.40, 0.34 g/L 의 정제분말이 얻어져 각각 6.3, 17.6, 1.4%의 수율로 회수되었고, 81, 97, 87%의 순도를 각각 나타내었다. 효소반응을 통한 DFAIII 생산 및 회수가 가장 높은 수율과 순도로 회수되었으며, 발효배양을 통한 DFAIII의 생산은 초기기질농도 25 g/L의 50%에 해당하는 DFAIII가 생산되었으나 효소반응에 의한 생산보다는 낮은 수율로 회수되었고 순도는 세 가지 방법 중 가장 낮았으며, 에탄올 침전반응은 가장 낮은 수율을 나타내었다.

• Mass Spectrometry Letters
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• 제10권1호
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• pp.18-26
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• 2019

We developed a bioanalytical method for simultaneous determination of nine NBOMe derivatives (25H-NBOMe, 25B-NBOMe, 25E-NBOMe, 25N-NBOMe, 25C-NBOH, 25I-NBOH, 25B-NBF, 25C-NBF, and 25I-NBF) in human plasma using liquid chromatography tandem mass spectrometry (LC-MS/MS). Human plasma samples were pre-treated using solid-phase extraction. Separation was achieved on a C18 column under gradient elution using a mobile phase containing 0.1% formic acid in acetonitrile and 0.1% formic acid in water at a flow rate of 0.3 mL/min. Mass detection was performed in the positive ion mode using multiple reaction monitoring. The calibration range was 1-100 ng/mL for all quantitative analytes, with a correlation coefficient greater than 0.99. The intra- and inter-day precision and accuracy varied from 0.85 to 6.92% and from 90.19 to 108.69%, respectively. The recovery ranged from 86.36 to 118.52%, and the matrix effects ranged from 27.09 to 99.72%. The stability was acceptable in various conditions. The LC-MS/MS method was validated for linearity, accuracy, precision, matrix effects, recovery and stability in accordance with the FDA guidance. The proposed method is suitable for reliable and robust routine screening and analysis of nine NBOMe derivatives in forensic field.

• Mass Spectrometry Letters
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• 제8권1호
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• pp.8-13
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• 2017

Analysis of quinidine for fish tissues using single drop microextraction (SDME) coupled with atmospheric pressure matrix assisted laser desorption/ionization mass spectrometry (AP-MALDI-MS) are reported. Optimization conditions; such as extraction solvent, extraction time, pH of the aqueous solution, salt additions (NaCl), stirring rate, matrix type and concentration are investigated. Linear dynamic range (${\mu}M$), limit of detection, relative recovery%, and enrichment factor are 0.08-9.2, 0.05, $94.8{\pm}3.1-98.5{\pm}3.3%$, $4.34{\pm}0.28-4.40{\pm}0.30$, respectively. SDME-AP-MALDI-MS shows good intraday and interday reproducibility.

• Food Science and Biotechnology
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• 제18권2호
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• pp.379-383
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• 2009

For an accurate risk assessment of furan, a potential human carcinogen, levels must be determined in human blood plasma using a simple and robust assay. In this study, solid phase microextraction-gas chromatography/mass spectrometry (SPME-GC/MS) was used to analyze blood plasma levels of furan in 100 healthy individuals who consumed a normal diet. The subjects were 30 to 70 years of age and 51% were women. Ultimately, an analytical method was established for analyzing furan in human blood. The limit of quantification (LOQ) and furan recovery rate in blood were 1.0 ppb and 104%, respectively. Finally, furan was detected in 21 individuals (13 males, 8 females) with levels ranging up to 17.86 ppb (ng furan/g food).

• Environmental Engineering Research
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• 제19권4호
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• pp.387-393
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• 2014

The purpose of this study is to evaluate integrated anaerobic hydrogen fermentation and membrane bioreactor (MBR) for on-site domestic wastewater treatment and resource recovery. A synthetic wastewater (COD 17,000 mg/L) was used as artificial brown water which will be discharged from urine diversion toilet and fed into a continuous stirred tank reactor (CSTR) type anaerobic reactor with inclined plate. The effluent of anaerobic reactor mixed with real household grey water (COD 700 mg/L) was further treated by MBR for reuse. An optimum condition maintained in anaerobic reactor was HRT of 8 hrs, pH 5.5, SRT of 5 days and temperature of $37^{\circ}C$. COD removal of 98% was achieved from the overall system. Total gas production rate and hydrogen content was 4.6 L/day and 52.4% respectively. COD mass balance described the COD distribution in the system via reactor byproducts and effluent COD concentration. The results of this study asserts that, anaerobic hydrogen fermentation combined with MBR is a potent system in stabilizing waste strength and clean hydrogen recovery which could be implemented for onsite domestic wastewater treatment and reuse.

• Archives of Pharmacal Research
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• 제17권5호
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• pp.364-370
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• 1994

A microscopic mass balance approach has been developed to estimate the extent and rate of absorption for camier-mediated comounds. For the case competitive inhibition in the presence of an inhibitor which shares the same camier, the fraction dose absorbed (F) and absorption rate constant ($K_a$) of a drug can be calculated from its concentration profile in the intestinal lumen. Absorption parameters obtained by single-pass perfusion experiments were used in the simultaion of the absorption of some aminopenicilins. Predicted fractions dose absorbed and absorption rate constants of ampicilin and amoxicilin were significantly reduced in the presence of a 6-times higher molar dose of cyclacilin. The drug-drug interactions on the competitive absroption of camier-mediated compounds were determined with regard to F and $K_a$. Predicted decreases in F for some aminopenicilins corrlated well with decrease in the urinary recovery in humans reported in the literature. Predicted decrease in the mean absorption rate constant ($\barK_a$) explain the delays in the time of peak plasma concentration ($T_{max}$) reported in humans.

• Mass Spectrometry Letters
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• 제9권4호
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• pp.95-99
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• 2018

An innovative, simple, and rapid assay method based on liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) was developed and validated for the simultaneous determination of eight statin drugs in human urine. A simple sample clean-up procedure using the "dilute and shoot" (DAS) approach enabled a fast and reliable analysis. The influence of the dilution factor was investigated to ensure detectability and reduce the matrix effect. Chromatographic separation was performed on a Phenomenex Kinetex C18 column ($50{\times}3.0mm$ i.d., $2.6{\mu}m$) using an elution gradient of mobile phase A composed of 0.1% acetic acid, and mobile phase B composed of acetonitrile, at a flow rate of 0.35 mL/min. Quantitation was performed on a triple quadrupole mass spectrometer operated in multiple reaction monitoring (MRM) mode using electrospray ionization in positive ion mode. The total chromatographic run time was 15 min. The method was validated for selectivity, sensitivity, recovery, linearity, accuracy, precision, and stability. The present method was successfully applied to the analysis of Rosuvastatin in urine samples after oral administration to healthy human subjects.

• 멤브레인
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• 제27권1호
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• pp.68-76
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• 2017

고강도, 내약품성, 무독성, 내연소성의 장점을 가지고 있는 PVdF (polyvinylidene fluoride) 나노섬유로 기공이 $0.4{\mu}m$ 평막을 제조한 후, 부직포와 평막으로 나권형 모듈을 제작하였다. 용존유기물의 흡착 제거를 위한 입상 활성탄(GAC, granular activated carbon) 흡착 컬럼과 자체 제작한 나권형 모듈로 혼성 수처리 공정을 구성하였다. 카올린과 휴믹산으로 조제한 모사 용액을 대상으로, 처리수를 재순환하는 경우와 배출하는 경우 각각 GAC 충진량의 영향을 알아보았다. 여과실험 후 물 역세를 하여 회복률과 여과저항을 계산하였다. 또한, 탁도와 $UV_{254}$ 흡광도를 측정하여 GAC의 흡착 효과를 고찰하였다. 그 결과, 처리수를 재순환하는 경우와 배출하는 경우 모두 탁도 처리율에는 GAC 충진량의 영향이 없었다, 하지만 GAC의 $UV_{254}$ 흡광도 처리율이 처리수를 순환하는 경우 0.7~3.6%이었는데, 처리수를 배출하는 경우 3.2-5.7%로 증가하였다. 처리수를 순환하는 경우 GAC의 충진량이 증가함에 따라, 가역적 여과저항($R_r$)과 비가역적 여과저항($R_{ir}$)은 감소하는 경향을 보였다. 그러나 총여과저항($R_t$)은 거의 일정하였고, 물 역세 회복률($R_b$)은 다소 증가하는 경향을 보였다.