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        검색결과 9

        1.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Considering the characteristics of aldehydes among volatile organic compounds, a combined process was established by linking an absorbent and a photocatalytic reactor. Experiments to find the optimal operating conditions of the combined process showed that as the amount of photocatalyst coating increases, the wavelength of the ultraviolet lamp used becomes shorter, the photodegradation rate becomes faster, and the removal efficiency increases. It was also demonstrated that by controlling the relative humidity during the connection process of the combined process, the re-evaporation phenomenon at the front end (absorption area) of the hybrid process can be improved and the removal efficiency at the back end (photocatalytic reaction area) can be significantly enhanced. This confirmed the need for a combined process that complements the advantages and disadvantages of each process.
        4,000원
        2.
        2014.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study tried to survey air quality inside and outside the schools where are located in about 5km of industrial complex targeting aldehyde, PM10, PM2.5. Also, the aim was also to examine both a change in indoor air after 3 years and within 3 years of addition and improvement, and a change according to season. It collected specimens at totally 20 places. Aldehyde was analyzed through HPLC. PM10 and PM2.5 were measured by using Met One 831. Formaldehyde and Acetaldehyde were detected with 42.1 μg/m3 and 5.7 μg/m3 at the school where is located inside 5km of the industrial complex, and were detected with 55.0 μg/m3 and 6.8 μg/m3 at the school where is located outside 5 km. This could be confirmed to have been detected more highly in the indoor air than the outdoor air regardless of the distance from the industrial complex. Most substances were indicated to be higher by about 150% in the indoor air within 3 years than the indoor air following 3 years of addition and improvement. However, PM10 and PM2.5 were measured with 32.6 μg/m3 and 14.9 μg/m3 after 3 years and were gauged with 22.4 μg/m3 and 14.2 μg/m3 within 3 years. Seeing a seasonal change, Formaldehyde and Propionaldehyde were detected with 5.5 μg/m3 and 1.0 μg/m3 in spring, 7.7 μg/m3 and 1.6 μg/m3 in summer, and 8.3 μg/m3 and 1.9 μg/m3 in autumn. This could be confirmed the tendency of growing according to season.
        4,000원
        3.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Swine manure discharged from pigery emits various odorous compounds. The most common method to reduce such odors is adding feed additives to swine feeds. However, whether the effects of such methods are truly effective are controversial. This research contrasts the aldehyde compound emission characteristics and removal effects from a treatment group, which were given feeds added with feed additives, to a control group, which were given feeds without feed additives. Sixty swine of age 26~28 days were evenly divided into six sections within an incubator type pigsty - each section contained ten weaners. Five types of feed additives, either currently in the market or in development were supplied. Gases sampled from the headspace in the odor producing reactor were analyzed by GC. Major malodorous compounds were estimated by the concentrations and threshold values from the detected components. Since 95.3% of the odor comes from isobutyraldehyde out of six types of aldehyde compounds (acetaldehyde, propionaldehyde, isobutyraldehyde, n-butyraldehyde, i-valeraldehyde, n-valeraldehyde), it can be regarded as the most critical compound contributing to pigsty odor. Aldehyde compounds showed statistically significant correlation with elimination of sulfide compounds and trimethylamine
        4,000원
        4.
        2012.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was aimed to evaluate the relationship between the concentration and dilution factor (ratio) using the Air Dilution Olfactory Method, which is suggested in the Standard Method of Odor Compounds, by measuring dilution factor for 5 types of aldehyde compounds and styrene. For the measurement, 13 panelists were selected by several criteria through panel test. Panelists chosen for their closely similar sensitivities provide more reproducible values. The estimation showed that the correlation of the concentration with dilution factor for the 12 compounds including the sulfur compounds, ammonia, and trimethylamine can be reasonably expressed by the equation log C=Af∙logD+F(Af: material constant, F: constant). The result of this study is suggested to be used as a base data for research on measures to improve the regulation standards for complex odor concentration on site boundary in operation, as well as a correlation between the concentration and dilution factor for the designated foul odor substances, and their characteristics.
        4,000원
        5.
        2006.06 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to investigate the concentration of aldehydes from new apartments in three cities(Suncheon, Yeosu, and Gwangyang) of Chonnam region. The target apartments were within 3 months after the completion of construction. Aldehydes were sampled using 2,4-DNPH cartridge and analyzed by HPLC. Temperature and relative humidity were monitored continuously every one minute by digital temperature and hygrometer. As the concentration ratio of formaldehyde between back-up and front cartridge was 3.94 6.97%, the 2,4-DNPH cartridge method satisfied a breakthrough problem for the sample collection. The repeatability of retention time and peak area for HPLC were excellent as 0.5 and 1.5%, respectively. The upper floor of S apartment (16 pyong) showed the highest concentration of formaldehyde as 1,093㎍/㎥. The average concentration of formaldehyde was the highest in K apartment(52 pyong) as 1,045㎍/㎥. The average concentration of formaldehyde in S apartment(16 pyong) and C apartment(25 pyong) were 872.6㎍/㎥ and 737.5㎍/㎥, respectively. The I/O ratios of formaldehyde were 56.9 60.0(mean : 59.1), 37.9 43.3(mean : 39.8) and 18.3 29.3(mean : 23.3) in K, C and S apartment, respectively. Therefore, it is believed that the indoor concentration of formaldehyde was very serious in new apartment. From these results, it is important that building material which emit low indoor pollutant should be selected for new apartments. In addition, management program for indoor air, such as using an adequate amount of adhesives, should be considered and indoor optimum condition should be maintained in new apartments.
        4,300원
        6.
        2014.02 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        A. oryzae로 발효한 청미래덩굴(Smilax china L.)잎 발효차의 적정 발효기간을 확립하고자 비 발효(NF) 및 10, 20 및 30일간 발효(F10, F20, F30)시킨 차 1% 열수추출물(1 tea bag 기준)의 색상, 관능검사 및 total polyphenol(TP), total flavonoid(TF), 전자공여능(EDA), 철환원력(FRAP), 과산화물 생성 억제능(LPOIA)을 조사하였다. 또, 체내 활성 산소(ROS) 생성계 효소인 동시에 요통과 음주로 인한 간 손상유도 및 이로 인한 복부비만에 직간접적으로 관여하는 xanthine oxidase(XO) 및 aldehyde oxidae(AO)의 저해활성에 미치는 영향을 조사하였다. 색상과 spectrum(400~700nm)의 변화를 조사한 결과, NF는 연한 황색을 띠는 반면 F10∼F30에서는 엷은 적색을 띠었으며 F10의 색상이 가장 선명하였다. 향(aroma)과 밝기(brightness)에 대한 기호도는 비발효차와 발효차간의 유의차를 보이지 않았으나 맛 (taste)과 입에 닿는 감각(mouth feel) 및 종합적인 기호도 (overall acceptability)는 F10, F20 및 F30 간의 뚜렷한 차이를 보이지 않아 발효 10일이 이상적인 발효기간이라 사료된다. TP 함량은 NF에서 41.55 mg/g(dry basis)이었으나 발효에 따라 거의 비례적으로 감소하였으며 그 감소율은 발효 10일째 24.91%, 20일째 56.92%, 30일째 64.41%를 나타내었다. TF의 함량은 NF에서 27.33 mg을 나타내었으나 발효에 점차적으로 감소하여 F10 24.30 mg/g, F20 17.32 mg/g, F30 13.22 mg/g으로 감소하였다. 그러나 TP의 감소율이 TF의 경우에 비하여 커서 TF/TP 비율(%)은 발효에 따라 증가하는 경향을 나타내었다. EDA는 NF에서는 29.01%이었으나 F10에서는 NF에 비하여 17.14%가 감소하였으며, F20 및 F30에서는 각각 18.79% 및 23.20%가 감소하였다. FRAP(μ M Fe2+)는 NF 4.63, F10 4.30, F20 및 F30에서는 각각 3.77 및 3.47로 발효에 따라 감소하는 경향을 보였다. LPOIA는 NF에서는 39.86%이었으나 F10의 경우는 31.92%로 NF에 비하여 19.92%가 감소하였고 F20 및 F30는 NF에 비하여 각각 23.61% 및 28.38%가 감소하였다. NF 및 F10∼30의 1% 열수추출액이 생유 및 토끼 간 조직으로부터 부분정제한 XO와 AO의 활성에 미치는 영향을 조사한 결과, XO활성에는 비발효, 발효 모두에서 뚜렷한 영향을 미치지 않았다. 그러나 AO의 활성은 비발효, 발효 관계없이 38.09∼41.70% 범위로 억제하였으며, 이러한 억제는 경쟁적 저해현상에 기인되어 나타난 것으로 생각된다.
        8.
        2005.02 KCI 등재 서비스 종료(열람 제한)
        염류내성 식물은 염류농도의 변화에 따라 세포내의 삼투압을 유지하기 위한 화합물을 합성하는 기작을 가지고 있는데 이런 화합물은 주로 proline, glycine, betaine, polyols, sugar등으로 체내에 축적함으로서 고농도의 염류에 견디는 것으로 알려져 있다. Betaine은 미생물에서 2단계 반응을 통해 choline에서 합성되는데, 첫단계는 choline dehydrogenase (CDH)에 의해서 촉매되고(Bet A gene), bet B 유전자의 산물인 betaine aldehyde dehydrogenase(BADH)에 의해 수행된다. 본 실험에서는 Bet A, Bet B 유전자를 아그로박테리움에 도입하여 새로운 conjugants 2 종을 획득하였으며 (Agrobacterium tumefaciens MP90/pBet A, Agrobacterium tumefaciens MP90/pBet B), 먼저 재조합된 binary vector가 식물에서 발현 및 형질 전환되는지 여부를 조사하기 위해서 이미 담배에 형질전환을 시켰으며, 형질전환된 담배에서는 ,고농도의 kanamycin배지에서 생장이 가능하였고, PCR에 의하여 NPT II, Bet A, Bet B gene를 조사한 결과 담배 유식물체 모두 band가 형성되어 형질전환체임을 확인할 수 있었다. 인삼에 Beth, BetB gene의 도입은 1M의 mannitol이 함유된 식물호르몬 무첨가 MS 배지에서 단일배 발생방법에 형질전환체를 획득하였으나, 형질전환체의 발생빈도(12%)가 매우 낮았다.