• 한국가스학회지
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• 제19권2호
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• pp.5-11
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• 2015

폭발한계는 가연성물질의 화재 및 폭발위험성을 결정하는데 주요한 특성치 가운데 하나이다. 많은 알데히드류는 연소열과 폭발한계, 화학양론계수와 폭발한계가 상관관계가 있음을 보여주고 있다. 본 연구에서, 알데히드류의 폭발하한계와 상한계에 대해 연소열과 화학양론계수를 이용하여 예측하였다. 제시된 예측식에 의한 예측값은 문헌값과 적은 오차범위에서 일치하였다. 제시된 방법론을 사용하여 다른 알데히드류의 폭발한계 예측이 가능해졌다.

• 한국환경과학회지
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• 제4권1호
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• pp.91-103
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• 1995

The reaction rate, equilibrium, and flow injection analysis methods were fundamentally evaluated for the determination of aqueous ammonia. The selected indophenol blue method was based on the formation of indophenol blue in which ammonium ion reacted with hypochlorite and phenol in alkaline solution. In the optimized reaction condition, the reaction followed 1st order reaction kinetics and the final product was stable. The absorbance measurements before and after the equilibrium were utilized for the reaction rate and equilibrium methods. The reaction rate methods, based on the relative analytical signals for the possibility of eliminating interferents, were shown to have good linear calibration curves but the detection limit and the calibration sensitivity were poorer than those in the equilibrium method. The detection limits were 32-49 pub and 24 pub for the reaction rate and equilibrium methods, respectively In the flow injection analysis, the absorbance was measured before the equilibrium reached and thus resulted in 30% reduction of calibration sensitivity. However, the detection limit was 11 ppb, indicating that the peak-to-peak noise for the blank was remarkably improved. Compared to the manual methods, the optimized experimental condition in a closed reaction system reduced the blank absorbance and the inclusion of ammonia from the atmosphere was prevented. In addition, highly reproducible mixing of sample and reagents and analytical data extracted from continuous recording showed excellent reproducibility.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1999년도 추계학술발표회요약집
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• pp.325.2-325
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• 1999

• 산업경영시스템학회지
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• 제17권31호
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• pp.91-98
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• 1994

Most of machines are physically or chemically degenerated by continuous usage. There- fore, a preventive maintenance is necessary. Producing defects are caused by process shift in mean and variance which are due to three types of degeneration. We develope the function of process variance from the experimental data and determine the optimal tool wear limit and the initial setting position of tool by considering the percent defective cost and the preventive maintenance cost.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2002년도 봄 학술발표회 논문집
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• pp.93-100
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• 2002

Vertical reinforcement of soft soils using the deep mixing method has received increasing applications. In this study, the theory of elasticity and plasticity including the upper bound theorem of limit analysis were used to derive the equations for obtaining composite elastic properties and shear strength parameters. The developed equations were validated using the finite element computer program SAGE CRISP. The analysis involved 4 different cases-two different type of soil and replacement ratios. Tile results of the analysis show that the proposed equations could determine the properties of composite material for practical applications.

• 약학회지
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• 제23권1호
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• pp.7-10
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• 1979

A gas chromatographic determination of dienestrol in dienestrol cream has been studied. Dienestrol cream was dissolved in pyridine and silylation was done by using N, O-bis (trimethylsilyl) trifluoroacetamide. The derivative was injected into 3% silicone OV-17 column for chromatographic estimation. The dienestrol peak was found to be well separated from the other components of the cream. The detection limit was obtained to be $5.6{\times}10^{11}$ mol of dienestrol for this method. As there is no need for prior separation procedure, this experiment is extremely simple and less time consuming as compared to the conventional methods for estimation of dienestrol in cream.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1999년도 말뚝기초위원회 워크샵
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• pp.35-52
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• 1999

This paper addresses on new codes of practice, limit state design; load resistance factored design and Eurocode 7, which have recently been adopted by foundation engineers in North America and European Communities. A brief description of the limit state design concepts and some introductions to Australia and Sweden national code for pile foundation are made on behalf of pile capacity determination. Also, simple closed form solution for rational resistance factor when resistance is log-normally distributed, has been derived for pile foundation.

• Bulletin of the Korean Chemical Society
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• 제25권7호
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• pp.1009-1011
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• 2004

In the present work a very simple, sensitive and selective spectrophotometric method for the determination of nitrite in micellar media is described. The method is based on the color reaction of nitrite with p-nitroaniline in the presence of diphenylamine in acid media. In order to remove the extraction step, Triton X-100, a non-ionic surfactant was used as micellar media. The optimum reaction conditions such as acid concentration, reagents concentration and effect of time have been studied and the analytical characteristics of the method such as limit of detection, linear range and molar absorptivity have been obtained. The interference of some anions and cations was also tested. The method was applied to the determination of nitrite in real samples.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 A
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• pp.28-30
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• 2000

This paper introduces a power flow model of SSSC for voltage stability study. The SSSC model is obtained from the injection model of voltage source inverter by adding the condition that SSSC injection voltage is in quadrature with current of SSSC-installed branch. This model is incorporated into modified CPF algorithm to study effects of SSSC on the security-constrained interface flow limit. Determination of interface flow limit is simply briefed. In case study a 771-bus real system is used to show that SSSC can improve interface flow limit in terms of voltage stability.

• Bulletin of the Korean Chemical Society
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• 제25권2호
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• pp.213-215
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• 2004

An indirect, sensitive and accurate method for the determination of trace amounts of hydrazine is described. The method is based on the oxidation of hydrazine by a known excess of iodate in the presence of hydrochloric acid. The unreacted iodate is used in the oxidation of hydroxylamine to nitrite. Sulfanilic acid is diazotized by the nitrite formed. The resulting diazonium ion is coupled with N-(1-naphthyl)ethylenediamine to form a stable azo dye, which shows an absorption maximum at 540 nm. Hydrazine can be determined in the range of 20-400 ng $mL^{-1}$ with a detection limit of 3.1 ng $mL^{-1}$. The relative standard deviation for 50, 200 and 400 ng $mL^{-1}$ of hydrazine is 2, 1.5 and 1.3%, respectively (n = 10). The method was applied to the determination of hydrazine in water samples.