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        검색결과 2,366

        401.
        2017.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, we analyzed the concentration of cadmium and mercury in urine and lead in blood from 668 residents in the exposed and compared areas in Gwangyang-si and Yeosu-si, from July 2013 to December 2015. According to the lifestyle (past smoking, current smoking, passive smoking, drinking and exercise), the concentration of cadmium in urine was higher in the compared areas than in the exposed areas in Gwangyang. However, the concentration of cadmium in urine according to the lifestyle except drinking was higher in the exposed areas than in the compared areas in Yeosu. According to the past smoking and current smoking, the concentration of mercury in urine was higher in the compared areas than in the exposed areas in Gwangyang, but the passive smoking, drinking and exercise showed similar concentration levels both in the exposed and compared areas in Gwangyang. The concentration of mercury in urine according to the past smoking and current smoking was higher in the exposed areas than in the compared areas in Yeosu, but the concentration of mercury in urine according to the drinking and exercise was lower in the exposed areas than in the compared areas in Yeosu. According to the past smoking, the concentration of lead in blood showed similar concentration levels in the exposed and compared areas in Gwangyang, but regarding current and passive smoking, it was higher in the compared areas than in the exposed areas in Gwangyang. Especially, the concentration of lead in blood according to the drinking in Gwangyang showed statistically significant difference (p<0.05). The concentration of lead in blood according to the lifestyle was higher in the compared areas than in the exposed areas in Yeosu.
        4,000원
        402.
        2017.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Numerical models of composite floor systems with various thickness of phase change material and sizes of circular spacers were developed based on finite element analysis. In order to perform a heat transfer analysis, thermal properties of steels were determined and those of phase change material were estimated from experiment results. In addition, the thermal insulation performance of composite floor systems with respect to different thickness of phase change material and sizes of circular spacers was predicted. To verify the validity of analysis, analysis results were compared with vertical furnace fire test results of equivalent conditions. As a result, available thicknesses of phase change material and sizes of circular spacers were proposed to satisfy the thermal insulation criteria of Korean Standards.
        4,000원
        403.
        2017.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        감마분광분석 시스템 상에서는 226Ra(186.2 keV)과 235U(185.7 keV)가 방출하는 감마선 에너지의 피크 중첩이 발생한다. 226Ra의 직접분석을 위해서는 중첩된 피크로부터 235U의 기여를 제거해주거나 보정상수를 이용하여 실제 226Ra의 방사능 값 으로 보정 해주어야 한다. 235U가 방출하는 다른 감마선 피크를 참조하여 235U의 기여를 제거할 경우 복잡한 수계산이 필요하며, 참조피크에서 기인하는 큰 불확도로 인해 높은 정량한계를 갖는다. 반면에 보정상수를 이용하여 226Ra을 평가할 경우 간단한 계산으로 평가가 가능하며, 간접측정시 요구되는 222Rn의 용기건전성과 방사평형 복구기간이 필요하지 않아 226Ra의 신속 측정시 유용한 방법이다. 따라서 해당 방법을 통해 원료물질 3종과 공정부산물 3종, 총 93여개 시료에 대해서 보정상수로 산출된 226Ra의 방사능 농도와 방사평형 된 214Bi의 방사능 농도의 비교를 통해 유효성을 확인하였다. 대부분 ± 20% 내에서 유효하였지만 인산석고의 경우 약 50%의 오차를 보였다. 이는 보정상수를 유도하기 위한 가정 중 238U과 226Ra의 방사평형 관계가 달라진 것으로 판단된다. 특이성을 반영한 보정상수를 적용하여 226Ra의 방사능 농도에 대한 유효성을 평가한 결 과 약 ±10%로 좀 더 정밀한 결과를 얻을 수 있었다. 본 연구에서 산출된 보정상수를 통한 226Ra의 방사능 농도 평가 방법은 복잡한 수계산이 필요하지 않고 용기선택으로부터 자유로우며 방사평형 복구를 위한 기간이 필요하지 않아 원료물질 및 공정부산물의 226Ra의 신속한 농도 분포 평가시 유효한 방법이다.
        4,000원
        404.
        2017.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The UV/chlorine process is a UV-based advanced oxidation process for removing various organic pollutants in water. The process is becoming increasingly popular because of its effectiveness in practice. It is important to the safe and efficient operation of a UV/chlorine process that the optimal operating conditions for both target removal objective and saving energy are determined. Treatment efficiency of target compounds in UV/chlorine process was mainly affected by pH and scavenging factor. In this study, kinetic based mathematical model considering water characteristics and electrical energy dose calculations model was developed to predict of treatment efficiency and optimal operating conditions. The model equation was validated for the UV/chlorine process at the laboratory scale and in pilot tests at water treatment plants.
        4,000원
        405.
        2017.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        To estimate pollution sources in the watershed with various industries, the simulation of contamination route and distribution of 2-methyl-4,6-dinitriophenol(DNOC) were performed with a numerical model Hydro Geo Sphere. This study was performed calculations of the load using the measured concentration and simulated flow rate. And, the river was divided by the sampling sites at the mainstream, and the contribution rate at downstream sampling sites was calculated for each section. The results showed the concentration of the downstream sampling sites were decided by the concentration of upstream sites, and the contribution rates of the tributaries were calculated below 10%. The results also showed that the impact of the potential sources in Section 1(Geumho1 ~ Geumho2) and Section 5(Geumho5 ~ Geumho6) was larger than in the other area. In Section1 and Section5, It seemed to require detailed investigation.
        4,000원
        406.
        2017.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Dyslipidemia, defined as elevated triglyceride (TG), total- and LDL-C, and/or decreased HDL-C levels, is considered a principal risk factor for cardiovascular disease. The low-density lipoprotein receptor (LDLR) family has been considered a key player in the prevention of dyslipidemia. The LDLR family consists of cytoplasmic membrane proteins and plays an important role not only in ligand–receptor binding and uptake, but also in various cell signaling pathways. Emerging reports state that various functional ingredients dynamically modulate the function of the LDLR family. For instance, oats stimulated the LDLR function in vivo, resulting in decreased body weight and improved serum lipid profiles. The stimulation of LRP6 by functional ingredients in vitro activated the Wnt/β-catenin pathway, subsequently suppressing the intracellular TG via inhibition of SREBP1, PPARγ, and C/EBPα. Furthermore, the extract of Cistanchetubulosa enhanced the expression of the mRNA of VLDLR, followed by a reduction in the serum cholesterol level. In addition, fermented soy milk diminished TG and total cholesterol levels while increasing HDL-C levels via activation of LRP1. To summarize, modulating the function of the LDLR family by diverse functional ingredients may be a potent therapeutic remedy for the treatment of dyslipidemia and cardiovascular diseases.
        4,200원
        407.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, we investigated influent and effluent water pollutants in 53 Public Sewage Treatment Works (PSTWs) where industrial wastewater or landfill leachate is combined four times for two years from 2014 to 2015. Also, we analyzed the characteristics of heavy metals and volatile organic carbons at influent and effluent of these PSTWs caused by sewage treatment combined with industrial wastewater or landfill leachate. As a result, six heavy metals such as barium, copper, iron, manganese, nickel and zinc, and four volatile organic carbons (VOCs) including phenols, di(2-)ethylhexyl phthalate (DEHP), formaldehyde and toluene were observed above detection limits in most of PSTWs. Also, it was revealed that six heavy metals such as hexavalent chromium, mercury, cadmium, chromium, nickel and selenium, and four VOCs including 1,1-dichloroethylene, vinyl chloride, naphthalene, and epichlorohydrin were observed more frequently according to precipitation. As a result of reviewing the monitoring data on “Water Quality Monitoring Networks” in lower watersheds of PSTWs, both heavy metals and VOCs were below detection limits, indicating that the effluent water had little influence on the watershed. Nevertheless for the better management of influent and effluent pollutants in PSTWs, it is necessary to establish the advanced management plans for water pollutants in PSTWs, which include a list of priority substances management, monitoring plans, and guidelines for industrial wastewater and landfill leachate combined in PSTWs.
        4,000원
        408.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, swine and cattle farms located in Jeollanam-do were selected to analyze and evaluate the components of odorants in livestock facilities. In addition, a preliminary survey of the literature was conducted to establish a sampling and analysis method for phenol and indoles which are major components of odor emissions from livestock facilities, yet are not regulated by the laws. To establish a sampling and analysis method for phenol and indoles, Tedlar bag and Tenax-TA sorbent tube was used as background concentration of blank sample and samples according to the elapsed time. The results obtained indicate the GC/MS analysis with Tenax-TA sorbent tube sampling was an effective method for measuring the compounds of phenol and indoles. In the swine facility, the rankings of the odorants in order, from highest to lowest, were ammonia, sulfuric compounds, phenol/indoles, volatile fatty acids. The main odorants were hydrogen sulfide (41.3%) and 4-methylphenol (p-cresol, 13.9%). In the swine slurry storage, hydrogen sulfide (33.7%), ammonia (18.8%), and 3-methylindole (skatole, 15.7%) were the main odorants, and hydrogen sulfide (31%) and i-valeric acid (32.4%) were the main odorants in the cattle farms.
        4,900원
        409.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study compared the stability of odor compounds in three different types of polymer sampling bags. Tedlar, PET (polyethylene terephthalate) and aluminized polyester bag were used. A sample was collected from the interior of a new automobile which was parked in an outdoor parking lot. It was found that the Tedlar bag showed lower stability for odor active compounds than the PET bag. Meanwhile, the PET bag had good stability for odor compounds compared to the aluminized polyester bag. The PET bag showed a stability for the molecules smaller than toluene that was comparable to the canister, but showed a lower recovery for molecules bigger than C7. The FID signal of the sample in the PET bag was reduced by 1.7times after 3days storage compared to 24 h storage. The number of detected odor active compounds was reduced by half, and odor intensity was also decreased by 2~3 degrees. Considering the factors of repeated use, usability and price, a PET bag covered with a black plastic bag was the most appropriate approach for odor sampling in an automobile interior.
        4,000원
        410.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objective of this experiment was to evaluate the effect of Chamaecyparis obtus extract to reduce odor emissions released from the swine feeding operations. Finisher pigs [Landrace × (Yorkshire × Duroc)] with an initial body weight averaging 50 kg were housed separately in two rooms with eighty eight pigs in each room at a swine feeding operation site. C. obtus extract was sprayed in the room by ceiling sprayer for one minute at twice per day during two months. Concentrations of odorous compounds from air in the room of the swine feeding operation were analyzed at four times during two months. Levels of butyric acid, valeric acid, i-butyric acid, ivaleric acid, skatole, methylmercaptan, and trimethylamine tended to decrease in C. obtus extract spray treatment group compared to the non-spray treatment group (P > 0.05). Odor activity values of butyric acid, valeric acid, skatole and trimethylamine were higher than other odorous compounds and decreased by 72%, 76%, 54% and 20%, respectively, in C. obtus extract spray treatment group compared to the non-spray group. Taken together, C. obtus extract showed an odor reducing capability in the air of a swine feeding operation suggesting that it possesses anti-bacterial properties as well as having a dust removal and masking effect.
        4,000원
        411.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Bloom of small centric diatom Stephanodiscus is quite occasional in winter season in temperate freshwater ecosystems. It often leads to degradation of water quality and affects the quality of supplied drinking water. In a previous study, we have found that naphthoquinone (NQ) 4-6 derivate is an effective tool for efficient mitigation of natural S. hantzschii blooms. In the present research, polylactide (PLA) and agar foam were used as immobilized agent for NQ 4-6 to improve the efficiency of NQ 4-6 compound releasing process for its application under various field conditions. Mesocosm experiments at 10 ton scale suggested that the abundance of S. hantzschii was continuously increased in the control and upon treatment of the mesocosm with immobilized NQ 4-6 from PLA and agar foam. Their algicidal activities were 78.8% and 77.1%, respectively, on S. hantzschii after 10 days. In the mesocosm experiments, the dynamics of biotic (bacteria, HNFs, ciliates, zooplankton) and abiotic (water temperature, dissolved oxygen, pH, conductivity, nutrients) factors remained unaffected. They exhibited similar trends in the control and treatment groups. Therefore, the immobilized NQ 4-6 from PLA and agar foam has potential to be used as an alternative algicidal substance to effectively mitigate natural S. hantzschii blooms under various field conditions. In addition, it not only can be used to control S. hantzschii, but also is an effective technique. The immobilized NQ 4-6 showed stable controlled release in desired system.
        4,200원
        412.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        There are more than 30,000 chemical substances handled in domestic university laboratories. Among them, hazardous materials are selected and managed as designated substances by the standards of 19 Ministries and 16 Acts. However, domestic safety-related laws and regulations are used to manage industrial risk factors based on industrial activities. In case of installing a university chemical laboratory in accordance with the installation standards applicable to general workplaces. It is not suitable to use as a laboratory installation standard that can be applied to a chemical laboratory installed at a university such as a problem occurs in applying to a university using a small quantity of dangerous substances in a small amount. In order to establish the laboratory structure and facility standards that are appropriate for the laboratory characteristics and apply systematic laboratory safety, the National Security Administration shall apply the special handling standard of chemical experiment to places where handling less than 30 times the designated quantity of chemical substances for chemical experiments. On August 2, 2016, the regulations for the enforcement of the Dangerous Goods Safety Management Act and the standards for the structure and facilities of the university chemical laboratory were enacted. In this study, we investigated the domestic chemical substances laws and regulations to determine the chemical substances that are over-regulated in the relevant laws, and define them as substances against accidents. The management criteria for the substances were analyzed. The R value for the designation of the designated quantity by the concept of the space in the management standard was calculated.
        4,900원
        413.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        OBJECTIVES : This is a basic research for the domestic production of airport-airside deicers. This research selected basic materials for deicers appropriate for the pavement of domestic airports by evaluating the deicing performances of basic materials used in internationalstandard airport deicers and their impacts on pavements. METHODS: Laboratory investigation was conducted to evaluate the asphalt surface tensile strength, concrete scaling impact, ASR impact, and deicing performances of sodium formate (NaFm), potassium formate (KFm), sodium acetate (NaAc), and potassium acetate (KAc), which are the basic de-icing materials commonly used at international airports, approved by the FAA. In addition, the analyses were also performed on the airside deicer urea, which is currently used in domestic airports. RESULTS : Laboratory investigation confirmed that sodium formate, potassium formate, sodium acetate, and potassium acetate had superior surface tensile strength, concrete scaling impact, and deicing performance compared to airside urea, but they also had greater impacts on concrete ASR. Among these materials, sodium formate had the best asphalt surface tensile strength, concrete scaling impact, and deicing performance, while also having the greatest impact on ASR; hence, mitigation plans for ASR were needed, if it were to be used as airport-airside deicer. CONCLUSIONS : It is necessary to consider additional additives to prevent ASR of concrete pavements when developing airport-airside deicers using sodium formate, potassium formate, sodium acetate, and potassium acetate.
        4,000원
        414.
        2016.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        국내 유통중인 다양한 형태의 원료물질 또는 공정부산물들에 대한 물리적, 화학적 및 방사선적 특성을 평가하기 위해 약 220 여 개, 총 16 종의 표본 시료를 선정하였다. 해당 시료들에 대하여 LaBr3 섬광검출기를 이용한 에너지 스펙트럼 측정과 에너 지 분산형 X-선 형광 분광기를 이용한 U, Th, K와 물질의 주요 성분 분석을 수행하였다. 그리고 HPGe 검출기를 이용하여 234Th, 234mPa 및 214Bi 등의 우라늄 붕괴계열 핵종들과 228Ac, 212Pb 및 208Tl 등의 토륨 붕괴계열 핵종들 그리고 40K 등의 방사능 농도를 분석함으로써 원료물질 및 공정부산물의 특성에 관한 기초자료를 수집하였다. 추가적으로 ROI구간별 계수율과 원 소성분함량, 방사능농도와 같은 특성변수들 간의 상관관계를 분석함으로써 스크리닝 장비를 이용한 방사능 농도 분포 유추 가능성을 평가하였다. 본 연구에서 구축된 특성 데이터베이스는 천연방사성핵종 분석을 위한 절차 및 방법을 수립하는데 유 용한 정보를 제공하고, 천연방사성핵종 분석에 대한 정확성 및 재현성을 향상시킬 수 있을 것으로 판단된다
        4,200원
        415.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        해상 유통되는 유해액체물질(NLS)의 유출사고대비 물질군 선정을 위해 596종의 NLS를 대상으로 위해성 DB를 구축하고 우선순위 선정시스템을 통해 전체 우선순위를 선정하였다. 우선순위 목록을 바탕으로 2014-2015년 해상유통물질 158종을 추출한 뒤 물질군 구분 기준을 적용하여 0~3순위의 4개 물질군을 제시하였다. 국가차원의 NLS 유출사고대비를 위해서는 물동량 및 유해성이 높은 0~1순위 물질군의 집중관리와 함께 2~3순위 물질군의 정보 구축작업이 지속되어야 한다. 항만별로는 NLS 유통 유형이 다르므로 각 항만의 물질별 유통특성을 파악한 뒤 0~1순위 물질군 위주로 관리하는 것이 효율적일 것으로 판단된다. 또한, 동해남부권역(울산, 부산), 남해중부권역(광양, 여수), 서해중부권역(평택, 대산, 인천)을 NLS 사고대비를 위한 특별관리구역으로 지정하여 해상유통되는 NLS 의 감시·감독을 강화하고 방제 장비, 자재 및 약제를 집중 배치해야 할 것으로 판단된다. 향후, 위해성 DB의 구축과정에서 나타난 위해성 정보 부재 물질들의(만성독성) 지속적인 생산 및 보완이 필요하며, 특히 수생태 독성의 경우 해양생물종을 대상으로 한 자료 생산 및 확보가 지속되어야 할 것이다. 또한, 해상 HNS 사고 관리를 위해서는 HNS 해상유통에 대한 정보를 확인할 수 있는 시스템이 조속히 구축되어야 한다.
        4,000원