• 멤브레인
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• 제2권1호
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• pp.49-58
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• 1992

Functionalized organic polymers have been used as supports for heterogenized homogeneous catalytic process[1]. Sprcific advantages of using these resins as support reagents have been reviewed[2-4]. These include: -ease of by-product separation from the main reaction product usuallyby simple filtration. -prevention of intermolecular reaction of reactive species or functional groups by simulating high dilution conditions[5]. -utility of the "fish-hook" principle in which a minor component in fished out of a large excess substrate by the insoluble polymer[6]. -the possibility of reusing recovered reagents as well as eliminating the use of volatile or noxious substances[7]. Catalysis by ion-exchange membranes is perhaps one of the latest examples of the use of a polymer-supported species. Conceptually, catalysts on membrane supports offer several possible advantages over traditional powder type systems. They are: (1) Membranes immobilize the catalyst, preventing agglomeration. (2) Filtration is unnecessary for the catalyst separation and so complete catalyst recovery is facilitated. (3) Catalytyic and separation processes can be combined, allowing membrane supported catalysts for the continous flow reactors. reactors.

• Membrane and Water Treatment
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• 제10권5호
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• pp.321-330
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• 2019

The objective of this study was to examine the recovery of the power plant cooling tower blowdown water (CTBD) by membrane distillation. The experiments were carried out using a flat plate poly vinylidene fluoride (PVDF) membrane with a pore diameter of $0.22{\mu}m$ by a direct contact membrane distillation unit (DCMD). The effects of operating parameters such as transmembrane temperature difference (${\Delta}T$), circulation rate and operating time on permeate flux and membrane fouling have been investigated. The results indicated that permeate flux increased with increasing ${\Delta}T$ and circulation rate. Whereas maximum permeate flux was determined as $47.4L/m^2{\cdot}h$ at ${\Delta}T$ of $50^{\circ}C$ for all short term experiments, minimum permeate flux was determined as $7.7L/m^2{\cdot}h$ at ${\Delta}T$ of $20^{\circ}C$. While $40^{\circ}C$ was determined as the optimum ${\Delta}T$ in long term experiments. Inorganic and non-volatile substances caused fouling in the membranes.

• Korean Journal of Otorhinolaryngology-Head and Neck Surgery
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• 제61권11호
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• pp.567-572
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• 2018

The sensory function of the trigeminal nerve is to provide tactile, proprioceptive, and nociceptive afference by chemical stimulation. Various physical responses of the trigeminal nerve to stimuli help to defend against harmful substances. Recently, many studies have been conducted on solitary chemoreceptor cells innervated by trigeminal nerve. Most volatile organic compounds stimulate both the olfactory and trigeminal nervous systems. In general, the trigeminal nervous system is less sensitive than the olfactory nervous system. Studies have shown that sensation of the trigeminal nerve by chemical stimulation results in inhibition of olfaction. This indicates that the olfactory and trigeminal nerves interact with each other in the central nervous system. It is important to study various noxious stimuli acting on the trigeminal nerve in modern society where environmental concerns are intensifying.

• Journal of the Korean Wood Science and Technology
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• 제50권2호
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• pp.104-112
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• 2022

Indoor air quality is a very important environmental factor in modern society. However, air pollutants generated from various interior construction materials significantly affect the human body, including formaldehyde (HCHO) and volatile organic compounds that threaten public health by deteriorating indoor air quality. Effective in removing these harmful substances are porous materials, such as woodceramics. In this study, charcoal, a porous material, was added to rice husk, an agricultural by-product, and sawdust generated during the sawing process to prepare boards and ceramics at different mixing ratios, and the HCHO deodorization performance and far-infrared emission characteristics were measured. As the mixing ratio of charcoal increased, the deodorization rate of the boards and ceramics tended to increase. Overall, the deodorization rate was measured to be 80% to 90%, indicating that the boards and ceramics prepared with charcoal are suitable to be used for the purpose of deodorization. The effect of the material mixing ratio on far-infrared emissivity and emission power was insignificant.

• 한국축산식품학회지
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• 제43권6호
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• pp.961-974
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• 2023

This study investigated the effects of mustard seed extracts on physicochemical and storage characteristics of dry-aged pork loin ham during the aging period. In experiment 1, antioxidant activity was assessed for mustard seed extracted with varying ethanol concentrations and the results showed high antioxidant activity at 25%, 50%, and 75% ethanol concentrations. In experiment 2, pork loin was treated with mustard seed extracts obtained using different ethanol concentrations: not treated (control), 25% (MS25), 50% (MS50), and 75% (MS75). Physicochemical and storage characteristics of pork loin ham were measured in wk 0, 2, 4, and 6. The pH, a_w, CIE b^*, thiobarbituric acid reactive substances and volatile basic nitrogen values were lower in treated samples compared to the control (p<0.05). In conclusion, applying mustard seed extracts, particularly MS75, in the dry-aged pork loin ham production process could enhance storage stability and improve color attributes without having negative impacts on product quality.

• The Korean Journal of Ecology
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• 제17권1호
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• pp.23-35
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• 1994

황해쑥은 독특한 향취가 나고, 군락을 이루는 경우가 많으며 약용으로 많이 쓰이는 다년생 초본이다. 황해쑥의 잎에는 어떤 화학물질이 함유되어 있으며 이들이 식물의 생장에 어떠한 효과를 나타내는지 조사하기 위하여 황해쑥의 잎 수용추출액을 농도별로 준비하여 새, 돌피, 소리쟁이, 상치의 발아실험을 실시했다. 그 결과 용식물의 종류별로 정도의 차이는 있었지만 발아가 억제되었다. 위와 같은 방법으로 생장시킨 4종의 식물에 유식물 신장생장은 앞의 발아 실험결과보다 덜 억제적이었다. 그런데 위의 추출액을 화분에 심은 식물에 공급하여 생장시킨 쇠무릅 식물은 발아, 신장 그리고 건중량생장이 모두 추출액 농도염가에 차등적으로 현저하게 억제되었다. 그러나 황해쑥 잎과 줄기에서 방산되는 휘발성 물질을 써서 실시한 발아와 유식물 신장생장실험 결과는 발아의 경우보다 신장시험의 값이 더 저조하게 나타났다. 그래서 황해쑥 잎에서 뽑은 청유로 돌피의 발아와 생장을 실험한 결과 대체로 높은 값을 얻었을 뿐 억제현상은 나타나지 않았다. 한편, 황해쑥의 청유를 써서 미샘물의 생장실험을 실시한 결과 대조구보다 실험구의 생장이 약간 억제되었고 또 반하와 벼 식물의 조직배양결과는 callus 생장율이 청유농도의 증가에 따라 심하게 억제되었다. 그래서 황해쑥에는 생장 제물질이 함유된 것으로 판명되었기에 GC/MS로 황해쑥잎을 화학분석하여 61종류의 성분을 처음으로 분리확인하였고 이들은 terpenoid가 대부분이었다. 이들중 9종류를 선택하여 생물학적 정량실험을 실시했으나 돌피의 발아와 생장율은 대조구와 실험구의 값이 거의 같은 정도로 큰 차이가 없었다. 결론적으로 종자발아시험, 어린식물 신장생장, 미생물 생장, 조직배양 실험결과를 종합해 보면 황해쑥에 함유된 천연 화학물질은 식물생장에 억제효과가 있음이 입증되었다.

• 한국환경농학회지
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• 제34권4호
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• pp.294-302
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• 2015

BACKGROUND: Chemical accidents have increased owing to chemical usage, human error and technical failures during the last decades. Many countries have organized supervisory authorities in charge of enforcing related rules and regulations to prevent chemical accidents. A very important part in chemical accidents has been coping with comprehensive first aid tool. Therefore, the present research has provided information with the initial applications concern to the rapid analysis of hazardous material using instruments in vehicle of field mode after chemical accidents. METHODS AND RESULTS: Mobile measurement vehicle was manufactured to obtain information regarding field assessments of chemical accidents. This vehicle was equipped with four instruments including gas chromatography with mass spectrometry (GC/MS), Fourier Transform Infrared Spectroscopy (FT-IR), Ion Chromatography (IC), and UV/Vis spectrometer (UV) to analyses of accident preparedness substances, volatile compounds, and organic gases. Moreover, this work was the first examined the evaluation of applicability for analysis instruments using 20 chemicals in various accident preparedness substances (GC/MS; 6 chemicals, FT-IR; 2 chemicals, IC; 11 chemicals, and UV; 1 chemical) and their calibration curves were obtained with high linearity ( r ² > 0.991). Our results were observed the advantage of the high chromatographic peak capacity, fast analysis, and good sensitivity as well as resolution. CONCLUSION: When chemical accidents are occurred, the posted measurement vehicle may be utilized as tool an effective for qualitative and quantitative information in the scene of an accident owing to the rapid analysis of hazardous material.

• Current Research on Agriculture and Life Sciences
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• 제6권
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• pp.7-12
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• 1988

우리 나라 재래종중(在來種中) 내용성분(內容成分) 면(面)에서 바람직한 향끽미(香喫味) 물질(物質)을 함유(含有)하고 있는 것으로 알려진 향초(香草)를 대상(對象)으로 이식시기(移植時期)가 향끽미(香喫味) 물질(物質)에 미친 영향(影響)을 구명(究明)하여 얻어진 결과(結果)는 다음과 같다. 전(全)알카로이드 함량(含量)은 7월(月) 5일(日) 이식구(移植區)가 4.16%로 가장 높고 5월(月) 20일(日) 이식구(移植區)는 1.37%로 가장 낮았으며, 니코틴 함량(含量)은 전(全)알카로이드 함량(含量)과 같은 경향(傾向)을 보였다. 전당(全糖) 함량(含量)은 4월(月) 20일(日) 이식구(移植區)가 12%로 가장 높았고 이것보다 이식(移植)이 빠르거나 늦을 수록 감소(減少)되는 경향(傾向)이었다. 석유(石油)에텔추출물(抽出物)은 4월(月) 5일(日) 이식구(移植區)가 5.77%로 가장 높았고 이식시기(移植時期)가 늦을 수록 감소(減少)하였다. 전당(全糖) 석유(石油)에텔추출물(抽出物) 전질소(全窒素)는 4월(月) 20일(日) 이식구(移植區)에서 가장 높았으며 이식시기(移植時期)가 빠를 수록 지방산(脂肪酸), malic산(酸)과 citric산(酸) 함량(含量)은 감소(減少)되었다. 이식시기(移植時期)가 빠를 수록 2.3-methylbutanoic산(酸), 3-methylpentanoic산(酸)의 함량(含量)이 증가(增加)되었다.

• 한국축산식품학회지
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• 제23권4호
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• pp.299-308
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• 2003

돈육소시지에 녹차의 다양한 생리 기능성을 부여하고 소시지의 저장성과 품질을 유지하면서 아질산염의 사용을 감소시킬 수 있는지 알아보기 위하여 녹차 분말을 첨가하여 돈육 소시지를 제조하여 저장 중 품질 특성을 살펴보았다. 아질산염(50, 100, 150 ppm)과 녹차(0, 0.5, 1.0%)를 첨가한 총 9개 시험군의 소시지를 제조하여 1$0^{\circ}C$와 2$0^{\circ}C$에 나누어 저장하면서 아질산염, TBARS와 VBN 등 저장성을 검사하였다. 수분, 조단백, 조지방, 조회분 등 일반성분은 녹차와 아질산염 첨가에 의해 영향을 받지 않았다. 색깔은 녹차 첨가량이 많을수록 밝기와 적색도가 감소한 반면 황색도가 증가하였다. 소시지의 아질산 잔류량을 분석한 결과 아질산염 첨가량이 동일한 경우 녹차 첨가량이 많을수록 아질산 잔류량이 적어 녹차 첨가가 아질산 잔유량 감소에 도움이 되는 것으로 나타났다. 녹차의 첨가는 소시지 제조 초기 및 저장 중 TBARS 값을 유의적으로 감소시켰으며, 이러한 녹차의 TBARS 감소 효과는 낮은 농도의 아질산염을 사용한 경우에 더욱 감소효과가 컸다. 저장 중 휘발성 염기태질소(VBN) 함량도 녹차와 아질산염을 첨가한 군에서 낮은 값을 보였다. 이상의 결과로 보아 돈육소시지에 녹차를 첨가함으로써 아질산 잔류량을 감소시킬 수 있을 뿐 아니라 저장성을 크게 훼손하지 않고 아질산염의 사용을 줄일 수 있다고 사료된다.

• 한국산업보건학회지
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• 제19권3호
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• pp.280-287
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• 2009

High-tech microelectronics industry is known as one of the most chemical-intensive industries. In Korea, Microelectronics industry occupied 38% of export and 16% of working employees work in microelectronics industry. But, chemical information and health hazards of high-tech microelectronics manufacturing are poorly understood because of rapid development and its penchant for secrecy. We need to investigate on chemical use and exposure control. We Site-visits to 6 high-tech microelectronics manufacturing company which have cleanroom work using over 1,000kg organic solvents (5 semi-conductor chips and its related parts company, 1 liquid crystal display (LCD)). We reviewed their data on chemical use and ventilation system, and measured TVOCs (Total Volatile Organic Compounds) and carbon dioxide concentration. All cleanroom air passed through hepa filters to acheive low particle levels and only 1 cleanroom uses carbon filters to minimize the organic solvents exposures In TVOC screening test, Cleanroom for semi-conductor chips and its related parts company with laminar down flow system (e.g. class 1~100) showed nondetectable level of TVOCs concentration, but Cleanroom for liquid crystal display (LCD) with conventional flow system (e.g. class 1,000~10,000) showed 327 ppm as TVOCs. Acetone concentration in cleanroom for Jig cleaning, LC Injection, Sealing processes were 18.488ppm (n=14), 49.762 ppm (n=15), 8.656 ppm (n=14) as arithmetric mean. Acetone concentration in cleanroom for LCD inspection process was 40ppm (n=55) as geometric mean, where the range was 7.8~128.7ppm and weakly correlated with ventilation rate efficiency(r=0.44, p<0.05). To control organic solvents in cleanrooms, chemical and carbon filters should be installed with hepa filters. Even though their volatile organic compounds concentration was not exceed to occupational exposure limits, considering of entrance limited cleanroom environment, long-term period exposure effects and adverse health effects of cleanroom worker need further reseach.