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        검색결과 6

        1.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In 1951, Colin Russell Austin and Min Chueh Chang identified “capacitation”, a special process involving ejaculated spermatozoa in the female reproductive tract. Capacitation is a phenomenon that occurs in vivo , but almost all knowledge of capacitation has been obtained from in vitro studies. Therefore, numerous trials have been performed to establish in vitro capacitation methods for various studies on reproduction. Although a series of studies have been conducted to develop an optimal protocol for inducing capacitation, most have focused on identifying the appropriate chemical compounds to induce the capacitation of boar spermatozoa in vitro. Therefore, the purpose of this study was to identify the optimal incubation time for inducing capacitation in vitro. Duroc semen was incubated for various periods (60, 90, and 120 min) to induce capacitation. Sperm function (sperm motility, motion kinematic parameters, and capacitation status) was evaluated. The results showed that total sperm motility, rapid sperm motility, progressive sperm motility, curvilinear velocity, and average path velocity significantly decreased in a time-dependent manner. However, the capacitation status did not show any significant changes. Taken together, these results indicate that an incubation time of more than 60 min suppresses sperm motility and motion kinematic parameters. Therefore, we suggest that 60 min may be the best incubation time to induce capacitation without negative effects on sperm motility and motion kinematics in boar spermatozoa in vitro.
        4,000원
        2.
        2021.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Sperm cryopreservation is an important method of assisted reproductive techniques and storing genetic resources. It plays a vital role in genetic improvement, livestock industrial preservation of endangered species, and clinical practice. Consequently, the cryopreservation technique is well organized through various studies, especially on Korean native cattle (Hanwoo). However, the cryopreservation technique of Korean native brindled cattle, which is one of the native cattle species in Korea, is not well organized. Therefore, it is necessary to develop a Supplementary Table technique for the cryopreservation of Korean native brindled cattle. For this purpose, it is important to first evaluate the quality of the currently produced cryopreserved sperm of Korean native brindled cattle. In this study, we randomly selected 72 individual Korean native brindled cattle semen samples collected from 8 different region research centers and used them to evaluate sperm functions. We focused on the quality evaluation of cryopreserved Korean native brindled cattle semen following the measurement of motion kinematics, capacitation status, intracellular ATP level, sperm motility, and cell viability. Then, the values of each of the eight groups were derived from various sperm parameters of nine individual samples, including sperm motility, kinematics, cellular motility, and intracellular ATP levels, which were used to compare and evaluate sperm function. Overall, differences in various sperm parameters were observed between most of the research centers. Particularly, the deviations of motility and motion kinematics were high according to the sample. Therefore, we suggest that it is necessary to develop a standard method for the cryopreservation of Korean native brindled cattle semen. We also suggest the need for sperm quality evaluation of the cryopreserved semen of Korean native brindled cattle before using artificial insemination to attain a high fertility rate.
        4,000원
        3.
        2017.07 KCI 등재 서비스 종료(열람 제한)
        This study performed a basic test to evaluate the energy value of food waste and ground coffee residue, and measured the calorific value of mixtures of food waste and ground coffee in the mass ratios of 1 : 1, 1 : 2, and 2 : 1. According to the results of this study, food waste, ground coffee, and their mixtures are technically viable as energy resources because they all meet Korea’s quality criteria for Bio-SRF. The proximate analysis results for food waste and ground coffee mixture showed 51.6% moisture, 46.2% combustibles, and 2.2% ash content. The high calorific value and low calorific value measured by the SE-C5500 Bomb Calorimeter were 4,602 kcal/kg and 3,927 kcal/kg, respectively. Heavy metal analysis showed the absence of mercury (Hg) and arsenic (As). Therefore, food waste, ground coffee residue, and their mixture sample met Korea’s quality criteria for Bio-SRF, which are technically and economically viable for use as bio-solid fuel (Bio-SRF).
        4.
        2016.11 서비스 종료(열람 제한)
        2014년 기준 대전광역시의 생활폐기물 발생량은 총 1451.2톤/일로 재활용품 496.7톤/일, 분리배출 음식물 400.1톤/일, 가연성폐기물 495.1톤/일, 불연성폐기물 59.3톤/일인데 매립으로 227.8톤/일이, 소각으로 297.6톤/일이, 재활용으로 925톤/일이 처리되어지고 있다. 이를 해결하기 위한 금고동 위생매립장은 대전광역시 전역에서 발생하는 생활폐기물 등 1일 평균 약 780톤을 매립 개시 후 1996년 8월부터 2020년(예상)까지 안정적으로 처리할 수 있는 대단위 위생매립장이다. 그러나 매립되는 폐기물의 성상 변화 및 2020년으로 예상되어지는 매립연한 때문에 문제가 발생하고 있다. 이를 해결하기 위해 환경에너지종합타운을 조성하여 반입되는 생활폐기물의 일부를 SRF 시설을 통해 고형연료화 할 예정이다. SRF 시설은 폐기물에 함유된 수분, 금속, 유리 등과 같은 불연성분을 건조, 파쇄, 선별 등의 공정을 통하여 제거하고 가연성분을 가공해 고체 연료화 하는 시설이다. 폐기물의 청정 처리는 물론, 에너지 효율도 높아 에너지 부족 문제 해결과 더불어 주거 및 대기환경 문제 해결이 가능하기 때문에 우리나라의 현실에 상당히 적합한 기술이라고 판단할 수 있다. 또한, 기존의 폐기물 소각시설에 비해 운영 비용이 적게 들며, 청정처리 과정을 거치기 때문에 님비(NIMBY) 현상에 따른 지역 주민들의 반발 우려도 적은 편이다. 2018년 2월 가동 예정중인 SRF 시설은 200톤/일×2계열 = 400톤/일 시설규모로써, 설계기준 가동 일수는 261일/년이고 가동시간은 16hr/일이다. 이 시설을 통해 매립장으로 반입되는 생활폐기물중 286톤/일 (400톤/일 × 261일/년 ÷ 365일/년)이 고형연료로 전환된다. 전환된 비성형 상태의 고형연료는 폐기물연료화부속시설의 보일러를 통해 에너지가 회수된다. 2018년 2월부터 시설이 본격적으로 가동되면 매립장으로의 반입폐기물량 변화는 불가피하다. 이를 분석한 결과 매립대상폐기물인 생활폐기물과 사업장생활계폐기물이 전처리시설로 투입됨으로써 매립되는 폐기물량이 17~21%까지 감소될 수 있으며, 이에 따라 매립장 사용연한의 연장도 꾀할 수 있다고 판단되어진다.
        5.
        2015.12 KCI 등재 서비스 종료(열람 제한)
        According to a report ‘2012 Present Condition of National Household Refuse Resource Recovery Facility’, about 582,178 tons/year of household refuse were processed in the incineration plant, and 465,087 tons/year of bottom ash and 117,091 tons/year of fly ash were produced respectively. As incineration ash contains many kind of heavy metals such as soluble salt, copper and lead, it may lead to the leaching potential of heavy metals according to the environmental change, so it requires special care in landfill and recycling. In this study CO2 was injected into the bottom ash, so that environmental stability such as leaching of heavy metals was reduced and increased the possibility of CO2 fixation ability of the bottom ash was analyzed. Bottom ash of the household refuse incineration plant of I City was used as the sample of the fixation ability particle size was divided into 3 sections to analyze its components before and after carbonation using XRF. Stability of the sample was identified by the leaching test through KSLT and TCLP, and CO2 fixation ability by the DT-TGA analysis. Test results of the fixation ability shows that stabilization of the bottom ash produced in the household refuse incineration plant by carbonation is evaluated as there is little environmental problem caused by heavy metals when it is utilized into the recycled aggregate, and economic profits can be expected due to securing new agents of the supply and demand for the recycled aggregates, the greenhouse gas emission reduction by CO2 fixation.
        6.
        2014.06 KCI 등재 서비스 종료(열람 제한)
        We examined the combined impacts of future increases of CO2 and temperature on the growth of four marine diatoms (Skeletonema costatum, Chaetoceros debilis, Chaetoceros didymus, Thalassiosira nordenskioeldii). The four strains were incubated under four different conditions: present (pCO2: 400ppm, temperature: 20℃), acidification (pCO2: 1000ppm, temperature: 20℃), global warming (pCO2: 400ppm, temperature: 25℃), and greenhouse (pCO2: 1000ppm, temperature: 25℃) conditions. Under the condition of higher temperatures, growth of S. costatum was suppressed, while C. debilis showed enhanced growth. Both C. didymus and T. nodenskioldii showed similar growth rates under current and elevated temperature. None of the four species appeared affected in their cell growth by elevated CO2 concentrations. Chetoceros spp. showed increase of pH per unit fluorescence under elevated CO2 concentrations, but no difference in pH from that under current conditions was observed for either S. costatum or T. nodenskioeldii, implying that Chetoceros spp. can take up more CO2 per cell than the other two diatoms. Our results of cell growth and pH change per unit fluorescence suggest that both C. debilis and C. didymus are better adapted to future oceanic conditions of rising water temperature and CO2 than are S. costatum and T. nodenskioeldii.