• 한국산학기술학회논문지
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• 제10권11호
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• pp.3269-3273
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• 2009

본 연구에서는 수용액 내의 오염물질 분해를 위하여 개발한 광촉매가 코팅된 실리카 비드의 광분해반응 사용에 따른 활성저하 문제를 해결하기 위하여 반응에 사용한 비드의 활성을 향상시킬 수 있는 재생 방법에 관한 실험을 수행하였다. 비드의 재생방법으로 표면 세정법을 선택하였으며, 세정액으로는 물(증류수), 계면활성제, 아세톤, 에탄올의 세정력이 서로 다른 4종의 용액을 사용하였다. 재생 과정은 서로 다른 4종의 세정액으로 반응에 사용하여 활성이 떨어진 비드를 세정한 후, 소성온도를 $100^{\circ}C$, $200^{\circ}C$, $300^{\circ}C$로 달리하여 30분간 처리하였다. 재생 처리과정은 각 1~3회 반복 수행하였으며, 서로 다른 조건에서 재생된 비드의 활성은 수용액 내의 methylene blue 광분해율로 측정하였다. 연구결과, 재생한 비드의 활성은 아세톤으로 세정한 후, $100^{\circ}C$에서 30분간 소성하였을 때 가장 우수한 것으로 나타났다.

• 센서학회지
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• 제6권6호
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• pp.445-450
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• 1997

후막형 암모니아 가스센서를 제조하여 가스 감지특성을 조사하였다. 저농도의 암모니아 가스에 감도가 우수한 산화물 반도체 감지물질은 $FeO_{x}-WO_{3}-SnO_{2}$ 이었으며 100 ppm 이하의 암모니아 가스에 노출될 때 감지막의 저항이 증가하는 특이한 경향을 나타내었다. 반면 암모니아 외의 일반적인 환원성 가스에 노출될 때는 저항이 감소하는 경향을 보였다. 이러한 암모니아 가스 감지소자와 감지물질이 Pt-doped $WO_{3}-SnO_{2}$ 로 구성된 보상소자를 결합하여 센서어레이를 제조하였으며 그 특성을 조사하였다. 보상소자는 암모니아 가스와 일반적인 환원성 가스모두에 의해 저항이 감소하는 경향이 있다. 센서 어레이는 감지소자와 보상소자를 하나의 기판위에 형성하여 제조되었으며 우수한 선택성을 얻을 수 있었다. 이러한 개념의 센서어레이를 이용하면 가스센서의 선택성 향상을 기할 수 있음을 확인할 수 있었다.

• 한국식품과학회지
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• 제31권2호
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• pp.391-398
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• 1999

국내산 생강의 높은 원료비를 극복하면서 품질이 우수한 중간소재성 가공제품을 개발하기 위하여 효소적 추출기법을 적용하였을 때의 수율 및 품질변화를 조사하였다. 생강을 1차 착즙하고 남은 잔사를 $\alpha$-amylase로 가수분해한 후 2차 착즙하고 다시 남은 잔사에 90% 에탄올로 $30^{\circ}C$에서 1시간 추출하여 각각 착즙액을 혼합할 경우 단순 착즙액보다 동일 $^{\circ}Brix$ 기준으로 약 2.8배 정도, 펄프보다는 건물기준으로 약 5배 이상 착즙수율을 증진시킬 수 있었다. 이와 같이 제조된 최종 추출액에는 착즙액 보다 조섬유가 약 62%, 전분이 48%정도 감소하는 결과를 나타내어 작업공정의 개선이 가능함을 알 수 있었다. 또한 최종 추출액은 착즙액에 비하여 유리아미노산이 약 40% 정도 소실한 반면 유리당은 약 270% 증가하는 결과를 보여주고 있어, 생강의 효소적 추출법은 생강 가공제품 제조시 단맛을 강화하는 효과를 제공할 수 있었다.

• 한국식품과학회지
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• 제16권1호
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• pp.1-6
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• 1984

담금수의 일부를 비율을 달리한 액체국(70%, 50%, 30%의 대체구)으로 대체한 후 곡류원료를 증자만 하여 고추장을 담금하고 고체국을 사용한 고추장과 숙성과정중의 성분을 비교하였다. 수분, 조단백질, 조지방, 염분, 에틸알콜은 각 시험구간에 큰 차이가 없었다. 고추장 숙성과정중의 아미노태질소, 수용성질소, 환원당 함량 및 pH는 대조구, 70%대체구, 50%대체구, 30%대체구의 순으로 높았다. 특히 대조구는 전 숙성기간을 통하여 pH 5.0 이상이었으며 적정산도는 50% 대체구와 30% 대체구에서 높았다.

• 한국재료학회지
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• 제20권2호
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• pp.78-81
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• 2010

Surface modification of silica nanoparticles was investigated using an aerosol self assembly. Stearic acid was used as surface treating agent. A two-fluid jet nozzle was employed to generate an aerosol of the colloidal suspension, which contained 20 nm of silica nanoparticles, surface modifier, and ethyl alcohol. Powder properties such as morphology, specific surface area and pore size distribution were analyzed by SEM, BET and BJH methods, respectively. Surface properties of the silica power were analyzed by FT-IR. The OH bond of the $SiO_2$ surface was converted to a C-H bond. It was revealed that the hydrophilic surface changed to a hydrophobic one due to the aerosol self assembly. Morphology of the surface treated powder was nanostructured with lots of pores having an average diameter of around $2\;{\mu}m$. Depending on the stearic acid concentration (0.25 to 1.0 wt%), the pore size distribution of the particles and the degree of hydrophobicity ranged from 1.5 nm to 180 nm and 29.6% to 50.2%, respectively.

• 대한수의학회지
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• 제31권3호
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• pp.319-327
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• 1991

Gingko biloba is one of the oldest trees on earth. It can be traced 300 million years or more into past. In recent years, this tree has become increasingly popular because of its longevity. Amount of comsumption of Gingko leaves in Korea is increased to produce drugs for blood circulating system's disorder. The workers who work at the company of product drug with Gingko leaves complain pruritus at belt position of west, however toxic substance from extracts of Gingko biloba was carried out to determine what kind of the toxic substance from extract could induce a contact dermatitis by means of histopathological study. Dried leaves of Korean G. biloba were exhaustively extracted with chloroform. The aqueous chloroform residue was extracted with hexane. After evaporation, the hexane extract was passed through a silica gel column chromatography, it was separated into 9 fractions by means of gradient solvent (benzene: acetone/ 98~93 : 2~7%). The 4th and 7th fraction were idendified as bilibol and gingkolic acid by silica gel thin layer chromatography and NMR spectrophotometer. The 4th and 7th fractions of Korean Gingko leaves have an irritant substances which can be induced ear swelling and increased thickness of stratum cornium of rabbit ear exposed with the fractions (3 time/3 day, $100{\mu}l$ of 50mg/ml ethyl alcohol). In the 4th fraction, the substance have induced the surface of ear to swell and mass of unknown cell like inflammatory cell were infiltrated within the stratum corneum, and the 7th fraction have the surface of ear to loss the hairs, and sebaceous gland and follicle of hair were infiltrated with inflammatory cells. and other fractions at all did not induced a certain contact dermatitis and also Deutschen drug of Gingko (named as Gerigeron) have induced the contact dermatitis such as dematitis of Korean Gingko extract.

• 한방재활의학과학회지
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• 제30권2호
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• pp.67-75
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• 2020

Objectives SJ004 is a natural herbal medicine that contains Acyranthes japonica Nakai and Eucommia ulmoides Oliver traditionally used for joint and spinal diseases. This study aimed to establish an efficient method of extracting SJ004 to standardize using the yield, high-performance liquid chromatography (HPLC), and antioxidant assay. Methods SJ004 was extracted with distilled water, 70% and 100% of ethyl alcohol (EtOH). The method validation of 20-hydroxyecdysone and pinoresinol diglucoside was determined by HPLC-photo diode array and the content of SJ004 was calculated. The antioxidant activity of each extract was compared and measured using total flavonoids, total phenolic compounds, 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), and ferric reducing antioxidant power according to the standard protocol. Results The yield was highest in pure water extract and lowest in 100% EtOH. But, the content of marker compounds indicating 20-hydroxyecdysone and pinoresinol diglucoside was highest in 100% EtOH extract. In the physiological activity measurement using antioxidant activity, 100% ethanol extract was highest. The limit of detection indicating 20-hydroxyecdysone and pinoresinol diglucoside were analyzed 0.33 ㎍/mL, 0.1616 ㎍/mL, and the limit of quantification were analyzed 1.01 ㎍/mL and 0.49 ㎍/mL respectively. Conclusions The experimental results showed that the extraction conditions have a significant effect on content of marker compounds and antioxidant activity. As a result of method validation, SJ004 was standardized by 20-hydroxyecdysone and pinoresinol diglucoside.

• Korean Chemical Engineering Research
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• 제46권5호
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• pp.965-970
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• 2008

접촉분해경유의 산화반응후 포함된 산화황화합물을 분리하기위해 다양한 용매를 사용하여 용매추출에 관한 연구를 수행하였다. 용매로는 극성을 가진 물, N-메틸피놀리논, 에틸아세테이트, 디메틸포름아마이드, 이소프로필알코올, 아세토니트릴, 메탄올등을 사용하였다. 실험결과, 접촉분해경유와 용매와의 층분리는 적절한 양의 물을 첨가한 경우에 이루어졌으며, 물과 N-메틸피놀리논을 혼합한 혼합용매가 접촉분해경유로부터 산화황화합물의 선택적인 분리에 가장 적절하였다. 또한 접촉분해경유로부터 황화합물을 99.5% 이상으로 제거하기 위해선, 4단 정도의 평형추출이 필요하였다.

• Bulletin of the Korean Chemical Society
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• 제30권12호
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• pp.3049-3052
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• 2009

Methyl tert-butyl ether (MTBE) is added to gasoline to enhance the octane number of gasoline, tert-butyl alcohol (TBA) is major degradation intermediate of MTBE in environment, and benzene, toluene, ethyl benzene and xylene (BTEX) are also major constituents of gasoline. In this study, a simplified headspace analysis method was adapted for simultaneous determination of MTBE, TBA and BTEX in ground water samples. The sample 5.0 mL and 2 g NaCl were placed in a 10 mL vial and the solution was spiked with fluorobenzene as an internal standard and sealed with a cap. The vial was placed in a heating block at 85 $^{\circ}C$ for 30 min. The detection limits of the assay were 0.01 ${\mu}$g/L for MTBE and BTEX, and 0.02 ${\mu}$g/L for TBA. The method was used to analyze 110 ground water samples from various regions in Korea, and to survey the their background concentration in ground water in Korea. The samples revealed MTBE concentrations in the range of 0.01 - 0.45 ${\mu}$g/L (detection frequency of 57.3%), TBA concentrations in the range of 0.02 - 0.08 ${\mu}$g/L (detection frequency of 5.5%), and total BTEX concentrations in the range of 0.01 - 2.09 ${\mu}$g/L (detection frequency of 87.3%). The developed method may be used when simultaneously determining the amount of MTBE, TBA and BTEX in water.

• 대한영양사협회학술지
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• 제10권1호
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• pp.34-46
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• 2004

The purpose of this study was to investigate disinfection state and effective factors of foodservice facilities and utilities of elementary schools in Busan area. Foodservice facilities and utilities investigated in this study were ceiling, wall, floor, trench, greasetrap, hood, pest and dumb waiter. The questionnaire which was administered to 196 dietitians was used as a survey method. The results were as follows. The washing method of foodservice facilities and utilities was mainly used by detergent washing-natural dry. The disinfection method of foodservice facilities and utilities was mainly sanitized by sodium hypochlorite. Dumb waiter and hood were sanitized by 70% ethyl alcohol and iodine. In washing and disinfection frequencies of foodservice facilities and utilities ceiling was twice/year, wall, hood and pest control facilities were once/week, floor, trench, greasetrap and dumb waiter were everyday, respectively. Floor, trench, greasetrap and dumb waiter were disinfected properly, whereas ceiling, wall, hood and pest were not disinfected properly. The washing method was related to dietitian's marital status and education. The disinfection state was related to dietitian's age and career, having of sanitation check list. The disinfection method was also affected dietitian's marital status, number of employee, duration of foodservice, number of total serving and having of sanitation check list. Therefore based on the results of this study, it should be given to the microbiological study on disinfection of facilities and utilities such as ceiling, wall, floor, trench, greasetrap, hood, pest and dumb waiter and the dietitian and employee's sanitation training also should be conducted continuously.