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        검색결과 38

        21.
        2012.03 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        The objective of this study is to quantify the levels of airborne bacteria in pig building according to pig housing type. Mean concentration of airborne bacteria in the housing room of gestation/farrowing pigs were 3,690(±1,528)cfu m-3 in spring, 10,145(±4,266)cfu m-3 in summer, 1,546(±835)cfu m-3 in autumn, and 2,582(±916)cfu m-3 in winter, respectively. Mean concentrations of airborne bacteria in the housing room of nursery pigs were 11,628(±5,624)cfu m-3 in spring, 36,054(±13,260)cfu m-3 in summer, 2,743(±1,688)cfu m-3 in autumn, and 4,075(±2,300)cfu m-3 in winter, respectively. Mean concentrations of airborne bacteria in the housing room of growing/fattening pigs were 34,025(±8,652)cfu m-3 in spring, 36,619(±10,234)cfu m-3 in summer, 10,230(±3,521)cfu m-3 in autumn, and 26,208(±5,248)cfu m-3 in winter, respectively. As a result, mean concentrations of airborne bacteria in terms of pig housing type were highest in growing/fattening housing room followed by nursery housing room and gestation/farrowing housing room (p<0.05). The pig building showed the highest levels of airborne bacteria in summer followed by spring, winter and autumn (p>0.05). Overall airborne bacteria which have particle size over 2.1㎛ (stage 1~stage 4) accounted for approximately 80% compared to total airborne bacteria regardless of pig housing type. The predominant airborne bacteria in pig building were Micrococcus spp., Brevibacillus spp. and G(+) Bacillus.
        4,000원
        22.
        2012.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        농산물의 안전성 확보와 품질평가를 위해서 신속하고 경제적인 비파괴 검사법에 대한 연구 및 기술개발이 활발하게 이루어지고 있다. 그러나 분광된 빛을 이용하여 내부 품질평가 과정에서 발생할 수 있는 분석 대상체의 성분 변화에 미치는 영향에 대한 연구는 미비한 실정이다. 따라서 본 연구는 분광분석을 이용하여 원유의 성분분석 과정에서 분광된 빛이 원유의 성분 및 체세포에 미치는 영향을 구명하고자 수행되었다. 본 연구에 사용된 원유는 일본 시가현 소재 낙농가에서 채취된 것으로 유지방, 유단백질, 유당, 무지고형분, 총고형분, 유요소, 구연산 및 체세포수를 화학적 방법에 의해 측정하였다. 또한 인위적으로 분광된 빛은 5가지 영역대로 구분하여 원유에 각각 1분, 5분, 10분간 주사하였다. 연구결과, 400 nm이하 파장대인 자외선 영역에서 유지방이 2.6% 증가되는 경향이 있었고, 체세포수도 9.0% 증가된 것으로 분석되었다. 그러나 다른 원유 성분에는 변화가 없는 것으로 나타났다. 따라서 자외선 영역의 빛을 원유 품질 평가에 적용하기 위해서는 보다 다양한 원유 시료에 대한 추가 검증이 필요할 것으로 사료된다.
        4,000원
        23.
        2011.12 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        The purpose of this study were to investigate the state of indoor environmental factors and energy consumption during winter in residential houses and to analyze factors which influenced this environment. Energy consumptions and indoor environmental factors of this survey were conducted in 21 houses(apartment, 11 and detached houses,10) between December, 2010 and February, 2011 which measured energy consumptions and indoor environmental factors as well as kept records of interviews with residents and other related factors. The results obtained were as follows. Indoor environmental factors which were found to influence apartment houses higher than detached houses. The average gas consumption of detached houses(90.983) was higher than that of apartment houses(76.333). Gas consumption showed positive correlations to temperature and carbon dioxide in the residential houses. The mean concentration of PM10, and CO2 in large family were higher than those of small family. We found that the more gas consumption, the higher concentration of PM10, CO2 and temperature(p<0.01).
        4,300원
        24.
        2011.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구의 목적은 공기감염성 가축질병 유발의 주요 인자인 부유 세균 및 바이러스 등의 생물학상 인자들에 대한 유형별 공기청정기의 제균 효과를 비교 평가하는 데 있다. 시료 채취 장비에 대한 포집 성능 평가에서는 MS2 바이러스와 Pseudomonas fluorescens 모두 Button sampler보다는 Biosampler에 의한 채취 효율이 유의하게 높았다 (p<0.05). 공기청정기 유형 및 시료채취 방법에 관계없이 MS2 바이러스의 경우 초기 농도 대비 가동 후 5분에 50% 이상, 15분에 70% 이상, 30분에 80% 이상, 그리고 마지막 측정 시점인 60분에는 90% 이상의 제거 효율을 보이는 것으로 나타났다. P. fluorescens 세균의 경우 초기 농도 대비 가동 후 5분에 45% 이상, 15분에 50% 이상, 30분에 70% 이상, 그리고 마지막 측정 시점인 60분에는 75% 이상의 제거 효율을 보이는 것으로 나타났다. 유형별 공기청정기의 상대적 제균 효율을 비교해 보면 MS2 바이러스의 경우 이온 발생 방식>전기 집진 방식>습식 방식>건조 방식, P. fluorescens 세균의 경우 전기 집진 방식>이온 발생 방식>건조 방식>습식 방식의 순서로 조사되었다.
        4,000원
        25.
        2011.03 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        The objective of this study is to assess a level of microbial contamination in the KTX. Investigation sites in the KTX were cabin, gateway, toilet and passenger seat. It was found that the mean concentrations of airborne bacteria and fungi were 157 CFU/m3 and 84 CFU/m3 , respectively, in all of the investigation sites of the KTX. They did not exceed the domestic standard (800 CFU/m3 ) for airborne bacteria and the guideline (150 CFU/m3 ) for airborne fungi recommended by WHO. Mean levels of bacteria and fungi distributed in passenger seat were 2.6×105 cfu/m3 and 3.7×104 cfu/m3 , respectively. The predominant genera identified in the KTX were Bacillus, Corynebacterium, Staphylococcus and Micrococcus for bacteria and Aspergillus, Cladosporium and Penicillium for fungi, respectively. Based on identification result, the profiles of airborne bacteria and fungi in the KTX was wholly similar to those of bacteria and fungi distributed in the passenger seat.
        4,000원
        26.
        2010.12 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to estimate concentration and emission unit of ammonia and hydrogen sulfide released from domestic chicken buildings by field investigation. Mean concentrations of ammonia and hydrogen sulfide emitted from chicken buildings were 18.25(±4.78)ppm and 807.53(±526.17)ppb for caged layer house, 14.48(±4.13)ppm and 644.82(±312.48)ppb for broiler house, and 6.16(±2.02)ppm and 284.75(±232.08)ppb for layer house with manure belt, respectively. Mean emission coefficients of ammonia and hydrogen sulfide were 0.951(±0.131) g hen-1h-1 and 2.956(±0.968) mg hen-1h-1 based on head whereas they were 0.575(±0.082) g m-2h-1 and 12.44(±3.536) mg m-2h-1 based on time. In conclusion indoor concentration and emission coefficient of ammonia and hydrogen sulfide were highest in caged layer housed, followed by broiler house and layer house with manure belt.
        4,000원
        27.
        2009.06 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        The aims of this study are to examine the concentration and identification of airborne organism at exhibit hall and storage in museums and to provide fundamental data to protect cultural assests from damage. This study surveyed the concentration of airborne bacteria and fungi at exhibit hall and storage in museums located 4 metropolitans from July to October, 2007 and literature data on airborne microbes of museums in Korea that were publiced in relevant Korean journals. The concentrations of airborne bacteria and fungi were higher than those in storage. Pseudomonas spp. and Bacillus spp for bacteria and Aspergillus spp. and Penicillium spp. for fungi were shown mainly in museums. Pooled average concentration of airborne bacteria in museums was 34.2±10.1 CFU/m3 for exhibit hall and 17.2±10.0 CFU/m3 for storage, respectively. Pooled average concentration of airborne fungi in museum was 26.0±11.2 CFU/m3 for exhibit hall and 16.6±11.0 CFU/m3 for storage, respectively.
        4,300원
        28.
        2007.03 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        The objective of this study is to offer basic scientific data to support policy decision-making for the improved control of suspended microorganism and to provide baseline data in order to improve the studies of bioaerosol in Korea. Therefore, this study collected and re-analyzed articles on suspended microorganism in various indoor environments and atmospheric environment in Korea that were published in environmental journals since 1980. The survey on the bioaerosol concentration in hospital among the public facilities have been performed abundantly. Also, the survey on the distribution of microorganism during yellow sand, pollen and fungus in atmosphere have been performed mostly. The impactional sampling method that is the sampling method of suspended microorganism have been used mostly in the survey on bioaerosol in Korea. Among the various indoor environments, the pooled average total bacteria concentration of 222.75 CFU/㎥ (95% CI:210.29 ∼ 245.22 CFU/㎥) was found in hospitals. It were lower than the guideline concentration (800 CFU/㎥) recommended by the Korean Ministry of Environment. And the pooled average concentration of bacteria and fungi in houses was 148.06 CFU/㎥(95% CI : 20.39 ∼ 275.74 CFU/㎥) and 22.66 CFU/㎥(95% C I:0 ∼ 49.73 CFU/㎥) respectively. Staphylococcus spp., Micrococcus spp., Enterococcus., Corynebacterium., Escherichia spp., and Pseudormonas spp. for bacteria and Penicillium spp., and Aspergillus spp. for fungi were showed in various indoor environments.
        4,500원
        29.
        2007.03 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        This study was to investigate distribution characteristics for air pollutants and to assess probability of health effect for children in kindergartens from August, 2006 to January, 2007. The mean concentrations for standards of maintenance in kindergartens were 91.5 ㎍/㎥ for PM10, 1,185 ppm for CO2, 69.3㎍/㎥ for formaldehyde, 174 CFU/㎥ for TBC and 0.41 ppm for CO, respectively. For NO2, Rn, TVOC, and O3, the mean concentrations in kindergartens were 29.40 ppb, 1.51 pCi/ℓ, 257.3 ㎍/㎥, and 3.74 ppb, respectively. The I/O ratio of every air pollutants exceeded "1" except for O3. In results of calculated safety factor to assess probability of health effect for children by air pollutants in kindergartens, safety factor for CO2 was 1.2 for fixed point. It means that children have probability of health effect caused by CO2. In cases of Monte-Carlo analysis, safety factor for PM10 was 1.0 and safety factor for CO2 was 1.2.
        4,000원
        30.
        2006.12 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        This study was undertaken to investigate the distribution characteristics of the hazardous agents in indoor environment in 7 vessels in Incheon harbor from July to August, 2004. The measured parameters include several indoor air pollutants (PM10, CO2, HCHO, and TVOCs) and physical parameters (noise, vibration, temperature, and humidity). The levels of pollutants and hazardous components in vessels were compared with standards and guidelines of indoor air quality on the Ministry of Environment and the Ministry of Labor in Korea. The major results obtained from this study were as followed : The PM10 and CO2 levels in every vessel did not exceed the indoor air standard of 150 ㎍/㎥ and 1000 ppm, respectively. The level of PM10 showed a decreasing tendency as the weight of vessels is increased. The airbornce concentration of HCHO was the highest one by exceeding its standard in a 500 ton vessel. The noise level in engine room exceeded the workplace standard (90 dB(A)) recording above 100 dB(A). The TVOCs level in every engine room was more than its standard (500㎍/㎥). Based on our preliminary study of indoor air pollutants in vessels, it is suggested that long and middle term plan for the management of IAQ should be established through future investigation of vessels.
        4,200원
        31.
        2006.09 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        This research was performed with the subject of 111 offices in a chemical plant of Korea. Airborne concentration level of carbon dioxide, carbon monoxide, formaldehyde and total suspended particulates in the office rooms were measured along with temperature and relative humidity. Simultaneously, general characteristics and subjective health symptoms of 500 office workers were investigated through a questionnaire consisting of the five point weighting method : 0 = not at all, 1 = a little bit, 2 = moderately, 3 = quite a bit and 4 = extremely. Results showed that the mean values for temperature and relative humidity in investigated office rooms were 22.2℃ and 34.3%, respectively. The concentrations of formaldehyde, PM10, carbon dioxide and carbon monoxide were 0.17 ppb, 28.8 ㎍/㎥, 0.95 ppm and 424 ppm, respectively. 56.4% of all the workers investigated replied with a sense of fatigue or weariness (mean=2.23), drowsiness or languidness (mean=2.22), sneezing (mean=2.11) and ophthalmia oreye fatigue (mean=2.07). Female workers, non-smokers, non-drinkers, workers who do shift more than nine hours a day, and workers in poor health experienced more subjective symptoms than other workers (p<0.05). Subjective symptoms of office workers were significantly associated with the following items of office characteristics: the purchase date of office equipment, the change of office furniture, the use of paint, smoking in the office, ventilation condition, the use of an individual air-conditioner, the use of a fax machine, the degree of office repair, the proportion of workers per office, the degree of satisfaction in office environment, and the operation hours of the air-conditioner. Also, subjective symptoms were positively correlated with indoor environmental factors such as relative humidity, carbon dioxide level, level of PM10, and formaldehyde (p<0.05). In conclusion, office characteristics and air quality in a chemical plant affected subjective health symptoms of office workers. Thus, in order to improve the health of workers, to enhance work efficiency, and to establish a better office environment, air quality control in office rooms by optimal ventilation, adequately occupied number of workers in one office, and maintenance of office equipment should be fulfilled thoroughly. keywords:Air quality, Subjective health symptom, Formaldehyde, PM10, Carbon monoxide, Carbon dioxide
        4,300원
        32.
        2002.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        폼드 아스팔트 공법은 가열 아스팔트 혼합물공법과 비교했을 때 골재와 아스팔트 가열에 필요한 다량의 에너지 소모가 없으며 가열로 인한 이산화탄소가 발생하지 않기 때문에 환경적으로 안정한 공법으로 평가되고 있다. 특히, 아스팔트 재활용 측면에서는 전체 혼합물량의 60~70% 까지 많은량의 폐 아스팔트를 사용할 수 있기 때문에 폐 아스팔트 재활용에 매우 효과적인 방법이다. 그러나, 폼드 아스팔트 공법은 항상 일정한 양질의 혼합물을 얻기가 어렵고 중(重)교통의 도로에 적용하기에는 문제점이 있다. 본 연구는 골재와 폐 아스팔트를 100°C 미만으로 가열하는 새로운 방식인 반 가열공법을 사용했을 때 얻어지는 반 가열 재생 폼드 아스팔트 혼합물의 성능과 반 가열 방식의 타당성에 대한 연구결과이다. 반 가열 방식으로 제조된 재생 폼드 흔합물을 실내에서 코팅율, 크리프시험, 회복탄성시험, 간접인장강도 및 마샬 안정도시험을 실시한 결과 혼합물의 현저한 개선 효과를 나타내었다.
        4,500원
        33.
        2002.03 구독 인증기관 무료, 개인회원 유료
        폼드 아스팔트 공법은 가열 아스팔트 혼합물공법과 비교했을 때 골재와 아스팔트 가열에 필요한 다량의 에너지 소모가 없으며 가열로 인한 이산화탄소가 발생하지 않기 때문에 환경적으로 안정한 공법으로 평가되고 있다. 특히, 아스팔트 재활용 측면에서는 전체 혼합물량의 60~70% 까지 많은량의 폐 아스팔트를 사용할 수 있기 때문에 폐 아스팔트 재활용에 매우 효과적인 방법이다. 그러나, 폼드 아스팔트 공법은 항상 일정한 양질의 혼합물을 얻기가 어렵고 중(重)교통의 도로에 적용하기에는 문제점이 있다. 본 연구는 골재와 폐 아스팔트를 100℃ 미만으로 가열하는 새로운 방식인 반 가열공법을 사용했을 때 얻어지는 반 가열 재생 폼드 아스팔트 혼합물의 성능과 반 가열 방식의 타당성에 대한 연구결과이다. 반 가열 방식으로 제조된 재생 폼드 흔합물을 실내에서 코팅율, 크리프시험, 회복탄성시험, 간접인장강도 및 마샬 안정도시험을 실시한 결과 혼합물의 현저한 개선 효과를 나타내었다.
        4,500원
        34.
        2001.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        상전환 방법에 의해 PVC계 MF막을 제조하여 환성슬러지가 포함된 폐수 처리용 MBR (Membrane bioreactor)에 적용하였다. 막 제조시 첨가제의 농도에 따른 막 특성을 확인한 결과 첨가제의 농도가 증가할수록 기공 크기가 증가하였으며 친수화도 역시 향상되었다. MBR의 내부 환경변화에 따른 실험을 통해 제조한 막의 투과 성능 및 막에 발생하는 막 오염 거동을 조사하였다. 사상균의 생성으로 인한 Sludge bulking 시 막 오염 현상이 가속화되었으며, 이 때 각 시료의 Rc을 조사한 결과 CP-0 > CP-1.0 > CP-1.5의 순으로 나타났고, 정상상태와 비교하여 sludge busking시 Rc값은 3.5~7배가지 증가하였다. 표면 특성이나 투과 유속면에서 PVP 1.5 wt% (CP-1.5)를 첨가하였을 때가 가장 적합하였다. 평균 투과 유속은 시료 모두에서 12(±2) L/m2hr 정도였으며, 평균 COD 제거율은 98.8% 정도를 나타내었다 MBR 운전에 있어 sludge bulking시 사상균이 차지하는 비율과 미생물의 모양과 크기에 따라 막 오염은 가속화 되었고, 투과 유속 감소를 보였다. 따라서 막 여과 특성은 막의 친수화 정도와 MBR 내부 미생물의 성장 조건과 환경에 의해 결정되는 것을 알 수 있었다.
        4,000원
        35.
        1999.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The present study was performed to evaluate the best electric fusion condition in nuclear transfer, Korean Native Cattle fibroblasts were used as nucleic donors. Oocytes from slaughterhouse were matured in vitro for 22 h and enucleated. Each individual cells were transferred into enucleated ocytes and reconstructed embryo were placed into the fusion chamber. In experiment 1, pulse were performed by altering pulse duration at 1. 75kv/cm, 1 time. When pulse duration is 30, fusion and development rates is higher than other conditions. In experiment 2, the effect of different pulse number were studied at the pulse duration 30 and the same pulse intensity. When pulse number was one, fusion rates were higher than other conditions. The fused embryos were moved to culture medium and assessed their development to blastocyst. These results showed that best fusion condition was 30 and one time. And the fibroblasts derived from Han Woo can be reprogrammed by nuclear transplantation and develop subsequently in vitro.
        4,000원
        36.
        1999.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The development potential of bovine somatic cells was evaluated using nuclear transfer. A single donor cell derived from fetus of HanWoo(Korean Native Cattle) was selected and deposited into perivitelline space of each enucleated oocyte before electrical fusion and activation. Nuclei of donor cells starved for 7 days (37%) tended to support the development of reconstitute embryo the blastocyst stage better than those of donor cells starved 3, 14 and 30 days. The cleavage rate was significantly lower(P<0.05) in reconstitute embryos derived from large size donor cells(51.2%), than those from small medium size donor cells(76.6 and 73.5, respectively). The developmental rate to blastocyst of reconstructed embryos from medium size donor cells was higher than those from small and medium size donor cells. This study demonstrates that an appropriate culture period for induction into quiescent stage and the size of donor cells effect on the efficiency of nuclear transfer using cultured bovine cells.
        4,000원
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