• 조명전기설비학회논문지
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• 제24권1호
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• pp.117-123
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• 2010

제안한 유도가열 시스템은 증류탑 장치에 사용되는 특수적층 규칙충진체에 의한 열 교환기술과 IH(Induction-Heating)전자유도가열용의 특수한 고주파 전력회로 기술을 응용한 차세대 가열방식이다. 본 전자유도 유체가열기술은 IGBT대응의 고주파 인버터를 사용하여 상용교류로부터 수[kHz]의 고주파 교류를 발생시킬 수 있다. 공진형 고주파 인버터를 사용함으로 고성능, 고효율의 시스템화가 가능하다. 본 논문에서는 주파수 범위가 20[kHz]에서 44[kHz]인 고주파 공진형 인버터을 이용하여 증기를 발생시키는 유도가열시스템에 대해 제안한 온도제어에 대하여 기술하고자 한다.

• 대한약침학회지
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• 제1권1호
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• pp.1-21
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• 1997

In order to investigate experimentally that effect of Moschus, Bovis Calculus, Ursi Fel aqua-acupuncture on acutely damaged liver of rats induced by radix aconiti, the author gave Moschus, Bovis Calculus, Ursi Fel aqua-acupuncture according to method of manufacture stimulation to corresponding points, Kan-su(B18) and Ki-mun(Liv14), and carried out hematological, serological observation. Experimental groups were divided into 2 group : the one group was injected with extracted solution prepared by distillation method (A aqua-acupuncture treatment group), the other group was injected with extracted solution prepared by alchol extraction method (B aqua-acupuncture treatment group). The following results were obtained : 1. WBC level was decreased significantly in the experimental groups at 12, 24 and 48 hours as compared with the control group. RBC and hemoglobin levels were not changed significantly in the experimental groups. 2. Total cholesterol level was decreased significantly in the experimental groups at 12, 24 and 48 hours as compared with the control group. ALP level was decreased significantly in the experimental groups at 6 and 24 hours as compared with the control group. ${\gamma}-GTP$ level was decreased significantly in the experimental groups at 6, 12, 24 and 48 hours as compared with the control group. 3. GOT level was decreased significantly in the experimental groups at 6 and 12 hours as compared with the control group. GPT level was decreased siginificantly in the experimental groups at 12, 24 and 96 hours as compared with the control group. According to the above findings, it is considered that Moschus, Bovis Calculus, Ursi Fel aqua-acupuncture has effects of recovery of acutely damaged liver.

• 한국안전학회지
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• 제24권1호
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• pp.31-36
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• 2009

This paper focuses on techniques of improving refinery reliability, availability, and profitability. Our team developed a corrosion control document(CCD) for processing of the crude distillation unit(CDU). Recent study shows the loss due to corrosion in US is around $276 billion. It's a big concern for both managers and engineers of refinery industry. The CCD consists of numerous parts namely damage mechanism(DM), design data, critical reliability variable(CRV), guidelines, etc. The first step in the development of CCD is to build material selection diagram(MSD). Damage mechanisms affecting equipments and process need to be chosen carefully based on API 571. The selected nine DM from API 571 are (1) creep/stress rupture, (2) fuel ash corrosion, (3) oxidation, (4) high temperature sulfidation, (5) naphthenic acid corrosion, (6) hydrochloric acid(HCL) corrosion, (7) ammonium chloride(salt) corrosion, (8) wet $H_2S$ corrosion, and (9) ammonia stress corrosion cracking. Each DM related to corrosion of CDU process was selected by design data, P&ID, PFD, corrosion loop, flow of process, equipment's history, and experience. Operating variables affecting severity of DM are selected in initial stage of CRV. We propose the guidelines for reliability of equipments based on CRV. The CCD has been developed on the basis of the corrosion control in refinery industry. It also improves the safety of refinery process and reduces the cost of corrosion greatly.

• 한국지능시스템학회논문지
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• 제24권3호
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• pp.330-336
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• 2014

연속교반탱크반응기, 담수화 플랜트, 증류탑, pH 중화 프로세스 등을 포함한 많은 산업용 프로세스들은 높은 비선형성과 시변 특성으로 인해 제어가 까다로워 보다 정밀하고 안정된 성능을 가지는 제어기를 설계하려는 많은 노력들이 있어 왔다. 본 논문에서는 기존 연구의 단점을 개선한 CSTR 프로세스의 농도제어용 PID 제어기를 동조하는 문제를 다룬다. 액추에이터 포화 문제를 극복하기 위해 PID 제어기에는 적분기 안티와인드업 피드백 루프가 구성되며, PID 제어기의 파라미터는 전체 제어 프로세스가 만족스러운 설정치 추종 성능을 가지도록 진화연산(EA)에 의해 동조된다. 제안하는 방법은 시뮬레이션을 통해 설정치 추종 성능, 외란 억제 성능과 파라미터 변동에 대한 강인성을 확인한다.

• 한국식품영양과학회지
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• 제23권3호
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• pp.481-489
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• 1994

Koji를 첨가한 저식염 멸치젖의 숙성 중 휘발성 향기성분의 변화를 대조구와 분석 비교하였다. 총 106개의 휘발성 성분이 검출되었는데 이 중에서 79개의 화합물은 표준품으로 확인 동정되었다. 이들은 주로 alde-hyde, ketone, alcohol, ester, aromatic hydrocarbon, furan 및 nitrogen-containing화합물로 구성되어 있었다. 숙성 중 두시료에서 aldehyde 및 ester류의 화합물의 종류와 함량이 가장 많았다. 특히 koji를 첨가한 멸치젓에서는 대조구에서는 검출되지 않은 2,6-dimethylpyrazine, 2-ethyl-6-methylpyrazine, trimethylpyrazine, 2-ethyl-3,5-dimethylpyrazine 및 tetramethylpyrazine 2-phenylethanol도 검출되었다.

• 한국조리학회지
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• 제17권4호
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• pp.273-284
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• 2011

수증기 증류법을 이용하여 약용 쑥으로부터 정유를 추출 하였다. 정유는 GC-MS를 이용하여 분석하였다. 가열처리 방법은 닦음에서 온도 $80^{\circ}C$, $110^{\circ}C$, $230^{\circ}C$, 처리 시간은 6분, 10분, 14분, 데침 $100^{\circ}C$에서 1분, 2분, 5분, oven 건조 ($50^{\circ}C$)는 5분으로 하였다. 정유함량은 대조군인 생쑥에서 가장 높았고 다음이 덖음의 낮은 온도 짧은 처리 시간에서 높게 나타났다. 가장 많이 나타난 정유 성분은 eucalyptol, cyclohexadience, phenol, terpineol, caryophyllene.이다.

• 생약학회지
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• 제43권4호
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• pp.291-296
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• 2012

The dried roots of Angelica decursiva and Peucedanum praeruptorum are registered as the official sources for the drug 'Junho' in Korean Herbal Pharmacopoeia. In this study the essential oils were extracted from the roots of the two plants by steam distillation. Their compositions and the biological activities were compared. As the results of GC and GC-MS analysis, forty one and thirty five compounds were identified in the essential oils of Angelica decursiva and Peucedanum praeruptorum, respectively. Both of the two essential oils contained ${\alpha}$-pinene as the most abundant component. They showed similar significant antioxidant activities in DPPH scavenging assay, and reducing power test. Their dose dependent inhibitions of the nitrosamine formation were identified in experiment using BHA as control. In MTT test of three cancer cell lines, HeLa, MCF-7 and SK-Hep-1, the essential oil from A. decursiva showed stronger activities than that of P. praeruptorum and their common main component, ${\alpha}$-pinene.

• 한국농공학회지
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• 제43권4호
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• pp.120-128
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• 2001

Pollution sources and their environmental contributions were investigated to select the best management practices for the effective control of water quality. The nitrogen isotope mass ratio was determined to estimate the nitrate sources and their contribution. Sampling sites were chosen by calculating effluent loads at each watershed. Two liters each of the surface water samples were collected from four sites at Bokha river and two sites and Gwanri river. They were sequentially prepared through distillation method and analyzed using an isotope ratio mass spectrometer(IsoPrime EA). As revealed by the experimental values obtained the mass ratio values ($\delta$$^{5}$ N) of watersheds with a large amount of nonpoint sources were less than +5 an indication that the samples were influenced by chemical fertilizers. However watersheds with large amount of point sources were influenced not only by chemical fertilizers but also by animal and municipal wastes. The mass ratio values of samples generally decreased during rainy days. But during dry days the mass ratio values well-reflected the nitrate sources and the condition of watersheds. Through this study the nitrogen isotope mass ratio has been found to be useful for estimating nitrate sources and their contribution to the rural watersheds.

• Food Science and Biotechnology
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• 제15권3호
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• pp.341-346
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• 2006

This study was performed to examine the effects of ${\gamma}$-irradiation on the volatile flavor compounds of dried leeks (Alliums tuberosum R.). Volatile compounds of dried leeks were extracted using simultaneous steam distillation and extraction (SDE), and analyzed by gas chromatography/mass spectrometry (GC/MS). Forty-one, 51, 45, and 42 compounds were tentatively identified in control, 1, 3, and 10 kGy irradiated samples, respectively. The constituents of flavor compounds in irradiated dried leeks were similar to non-irradiated samples. However, the intensities of the peaks were clearly different between them. Sulfur-containing compounds were detected as dominant compounds in all samples and their amounts decreased after ${\gamma}$-irradiation. ${\gamma}$-Irradiation reduced the total concentration of volatile compounds from leeks by 23.19, 15.09, and 30.23% at 1, 3, and 10 kGy doses, respectively.

• 한국산업보건학회지
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• 제4권1호
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• pp.33-42
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• 1994

This study was carried out to assess worker exposure to vinyl chloride monomer (VCM) and to present control measures in the factories processing and producing polyvinyl chloride (PVC) resin. The conclusion remarks are as follows. Only two personal samples in the factory ("E") processing polyvinyl chloride resin were analysed to be 27.6 ppm and 12.6 ppm, respectively. But, these concentration exceed 1 ppm, Permissible Exposure Limits (PEL) of OSHA. So, worker's exposure to VCM at "E" factory should be reevaluated. In "A", "B" and "C" factory producing polyvinyl chloride resin, the average worker's exposures to VCM were 0.12 ppm, 0.86 ppm and 1.23 ppm, respectivery. Worker exposure to VCM at distillation and dry process was higer than other processes at "A" factory. The average exposure concentration of worker at polymerization process of "B" and "C" factory was 1.23 ppm, and 1.46 ppm respcetively. These concentration exceed 1 ppm, Permissible Exposure Limits of OSHA. Control room of "B" and "C" factory had 0.91 ppm and 0.65 ppm of worker's exposure concentration respectively. "A" factory was evaluated to be "acceptable", but "B" and "C" factories were evaluated to be "not acceptable", by the workplace exposure assessment program of AIHA. Process other than bagging and control room of "A" factory was evaluated to "not acceptable". Immediate correction measures for preventing workers from exposure to VCM should be performed in the factories or process that were evaluated to be "not acceptable". After these control measures are taken, worker exposure to VCM must be reevaluated through personal air monitoring. Control measures presented by this study are complete sealing of connecting pipe lines, flanging, packing, bolting and nutting. Periodic leak test for leak parts is also required. And positive pressure facility should be constructed at control room of "B" and "C" factory. Fresh air through cleaner such as HEPA filter should be supplied to control room. In addition to these control measures, periodic personal monitoring for evaluating worker exposure to VCM should be performed.