• 공업화학
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• 제7권6호
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• pp.1204-1208
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• 1996

파라자일렌(p-xylene)을 산화반응시켜 테레프탈산(terephthatic acid)을 제조하는 과정 중에 발생하는 주요 유기불순물을 효과적으로 분석하는 방법을 수립하였다. 이 제조공정 중에 발생하는 유기불순물은 매우 다양하나, 여기에서는 주로 benzoic acid, p-toluic acid, p-tolualdehyde, 4-carboxybenzaldehyde, phthalic acid, isophthalic acid, trimellitic acid와 4-hydroxymethyl benzoic acid 등의 유기불순물을 분석하는데 촛점을 맞추었다. 이 유기물들은 공정 중의 모액이나 고체상태의 테레프탈산 입자에 존재하는데, 이들을 동시에 분석하기 위해 99% bis(trimethylsilyl)trifluoroacetamide와 1% trimethylchlorosilane의 내부표준용액과 pyridine의 혼합용액내에서 trimethylsilylation으로 시료를 전처리하고 gas chromatography를 이용하여 분석한 결과 상기한 유기물이 모두 성공적으로 분리되어 50분 이내에 정량분석할 수 있었다.

• Natural Product Sciences
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• 제22권4호
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• pp.259-262
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• 2016

The content analysis of fatty acids in Perilla cultivars and commercial oils is conducted through gas chromatography with a flame ionization detector. Results show that Perilla cultivars, such as Deulsaem and Daesil, contain high amounts of ${\alpha}-linolenic$ acid (262.22 and 261.97 mg/g, respectively). Among commercial oils, Perilla oil contains a higher amount of ${\alpha}-linolenic$ acid (515.20 mg/g). Accordingly, ${\alpha}-linolenic$ acid is a major fatty acid of Perilla cultivars and oil. Therefore, Perilla cultivars could be used as a food supplement for nutritional and pharmaceutical purposes.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 춘계학술대회 논문집 전기설비전문위원
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• pp.33-36
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• 2009

In this paper, evaluation of physical properties was made for dielectric relaxation phenomena by the detection of the surface pressures and displacements current on the monolayer films of fatty acid monomolecular Arachidic Acid, Stearic Acid using compressing velocity. LB(Langmuir-Blodgett) thin films were manufacture by detecting deposition for the accumulation and the current was measured after the electric bias was applied across the manufactured MIM device. The physicochemical properties of the fatty acid monomolecular Arachidic Acid, Stearic Acid films surface structure has been studied by AFM. We give pressure stimulation into organic thin films and then manufacture a device under the accumulation condition that the state surface pressure is gas state, liquid state, solid state. Formation that prevent when gas phase state and liquid phase state measure but could know organic matter that molecules form equal and stable film when molecules were not distributed evenly, and accumulated in solid state only.

• Corrosion Science and Technology
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• 제22권5호
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• pp.351-358
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• 2023

Although many thermal power plants use heat recovery systems, high exhaust gas temperatures are maintained due to corrosion at dew points and ash deposits caused by condensate formation. The dew point of exhaust gas is primarily determined by the concentration of SO₃ and steam, and various experiments and calculation equations have been employed to estimate it. However, these methods are known to be less suitable for exhaust gases with low SO₃ concentrations. Therefore, in this study, since the temperature of the exhaust gas is expected to decrease due to the low-load operation of the coal-fired power plant, sulfuric acid condensation and low-temperature corrosion are anticipated. We aimed to conduct a quantitative evaluation to propose ways to prevent damage by limiting operating conditions and improving facilities. The experimental results showed that the corrosion rate increased linearly with rising temperatures at a certain sulfuric acid concentration. Furthermore, variations in sulfuric acid concentrations generated during the current power plant operation process did not significantly affect the dew point, and the dew point of sulfuric acid under these conditions was observed to be between 120 - 130 ℃.

• 한국축산식품학회지
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• 제36권2호
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• pp.206-214
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• 2016

The aim of this study was to evaluate the potential use of fatty acids, triacylglycerols, and cholesterol in the detection of adulterated milk fat. The fatty acid, triacylglycerol, and cholesterol profiles of the mixtures of milk and non-milk fat (adulteration ratios of 10%, 30%, 50%, 70%, and 90%) were analyzed by gas chromatography. The results showed that concentrations of the fatty acids with oleic acid (C18:1n9c) and linoleic acid (C18:2n6c), triglycerides with C52 and C54, and cholesterol detected are proportional to the adulteration ratios remarkably. Oleic acid (C18:1n9c), linoleic acid (C18:2n6c), C52, and C54 were lower in pure milk fat than in adulterated mixtures. In contrast, pure milk has a higher cholesterol concentration than all adulterated mixtures (adulteration concentration in the range 10-90%). Thus, we suggest that oleic acid (C18:1n9c), linoleic acid (C18:2n6c), C52, C54, and cholesterol are suitable indicators and can be used as biomarkers to rapidly detect adulterated milk fat by gas chromatography. This study is expected to provide basic data for adulteration and material usage. Moreover, this new approach can detect the presence of foreign oils and fats in the milk fat of cheese and can find application in related studies.

• Asian-Australasian Journal of Animal Sciences
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• 제16권1호
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• pp.39-43
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• 2003

Dietary fatty acid including mainly palmitic acid and stearic acid was fed to fattening cattle and its effect on body weight gain, plasma lipid contents and rumen liquid fermentation in vitro was examined. In expt. 1, the effect of dietary fatty acid on body weight gain and plasma lipid concentrations was examined. In the control diet group, cattle were fed 1 kg/day of rice straw and concentrate which satisfied the requirement. In the fatty acid group, cattle were given 250 g/d of fatty acid with the same diet of the control diet group. In the excess concentrate group, cattle were given the same diet of the control diet group plus 735 g/d of concentrate corresponding to the same TDN of 250 g/d of fatty acid. Diets were given for 7 days. Body weight gain of cattle given dietary fatty acid was significantly greater than that of cattle fed only rice straw and concentrate. When dietary fatty acid was added to cattle feed, plasma NEFA and HDL-cholesterol concentrations increased. In expt. 2, the influence of dietary fatty acid on gas production and VFA profile in the rumen liquid was investigated in vitro. In the control group, 10 mg of rice straw and 90 mg of concentrate were incubated in the rumen fluid. In the excess concentrate group, 10 mg of rice straw and 97.5 mg of concentrate were incubated. In the fatty acid group, 10 mg of rice straw, 90 mg of concentrate and 2.5 mg of fatty acids were incubated. The rumen liquid mixed with feed materials was incubated for 24 h and the cumulative gas volume was measured. The VFA profile was also measured. Cumulative gas volume in the rumen liquid with fatty acid was equal to the control. Excess concentrate increased cumulative gas volume compared to the fatty acid group. There was no significant difference in total VFA concentration between experimental diet groups. It is suggested that dietary fatty acid has the potency to improve growth performance in fattening cattle without failure in rumen fermentation.

• 한국균학회지
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• 제15권1호
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• pp.9-13
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• 1987

한국산 백복령을 chloroform-methanol(2 : 1, v/v) 혼합용매로 추출한 다음, 비누화 및 메델에스테르화 한 후 gas chromatography에 의하여 얻은 총24개의 Peak 중, caprylic acid($C_{8:0}$), undecanoic acld($C_{11:0}$) lauric acid($C_{12:0}$) , dodecenoic acid($C_{12:1}$) 및 Palmitic acid($C_{16:0}$)의 5 개 성분을 확인하였으며, 그중 주성분인 $C_{8:0}$과 $C_{12:1}$은, 시료 g당 $6.657{\mu}g$ 및 $10.176{\mu}g$ 이었다.

• 한국가스학회지
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• 제3권2호
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• pp.70-76
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• 1999

이산화황 배출에 대한 대기 오염 방지법의 엄격한 규제로 인하여 황산제조 업체에서는 가능한 높은 전화율을 얻는 방법에 관심을 갖고 있다. 본 연구에서는 현재 가동하고 있는 황산공장의 이중 접촉식 전환탑 공정에서 전화율을 증가시키고 배출되는 이산화황 가스의 농도를 최소화하기 위하여 매개변수 분석과 공정최적화 방법을 사용하였다. 이중 접촉식 전환탑 공정에 대하여 공급되는 이산화황의 조성, 각 촉매층 도입부의 압력과 온도, 촉매층의 높이의 변화에 대한 전화율 변화를 살펴보기 위해 공정 모델링과 컴퓨터 모사 프로그램을 개발하였다. 이를 통해 삼산화황으로의 최대 전화율과 배출되는 잔여 이산화황 가스 농도의 최소를 위해 촉매층의 도입부의 온도와 촉매층 높이를 최적화하였다. 이 최적치는 높은 전화율을 유지하도록 하는 전환탑 설계와 조업 조건의 지침이 될 것이다.

• 한국식품과학회지
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• 제32권5호
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• pp.997-1001
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• 2000

Gas chromatography를 이용한 profiling과 신속한 동정을 허브류에 존재하는 유기산의 분석에 적용하여 보았다. 흡착제로 Chromosorb P와 용출 용매로 diethyl ether를 사용하는 고체상 추출법을 이용하여 허브추출물로부터 유기산을 분리한 후, tert-butyldimethylsilyl 유도체로 만들어 극성이 다른 DB-5와 DB-17 컬럼으로 동시분석하였다. 두 컬럼에서 분리된 유기산 피크들을 dual capillary column system의 retention index(RI) library 탐색과 RI specta 비교로 신속하고 정확하게 동정할 수 있었으며 이들을 GC-MS로 확인하였다. 허브추출물들의 유기산 분석 결과 fatty acid, dioic acid, hydroxy acid, aromatic acid등 24가지의 유기산이 동정되었고 각 허브의 종류에 따라 특징적인 유기산 GC-profile을 나타내었다. 각 허브추출물의 GC profile의 유기산 조성만을 단순화시킨 RI spectra로 표현한 결과, 각 허브의 유기산 패턴의 분별이 매우 용이하였다.

• 한국수소및신에너지학회논문집
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• 제31권5호
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• pp.405-410
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• 2020

In this literature, we are introduce a basic design of multi energy hub based on natural gas governor station. Multi energy hub consists of turbo expender generator, phosphoric acid fuel cell, pressure swing adsorption, H₂ charging station, utilities and etc. We design a hybrid energy hub system that provides energy using these complex energies, and calculates the amount of electricity that can be produced and the amount of hydrogen charged through the process analysis. TEG and phosphoric acid fuel cell produce 2,290 to 2,380 kW and can supply electricity to 500 houses. In addition, By-product H₂ gas is refined to H₂ vehicle fuel. This will help maximize the balance of energy demand and supply and improve national energy efficiency by integrating unused decompression energy power generation technology and various power generation/heat source technologies.