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        검색결과 15

        1.
        2024.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: Sperm quality and the number of sperm introduced into the uterus during artificial insemination (AI) are pivotal factors influencing pregnancy outcomes. However, there have been no reports on the relationship between sperm concentration at AI and sperm quality in Hanwoo cattle. In this study, we examined sperm quality and pregnancy rates after AI using sperm inseminated at different concentrations. Methods: We evaluated the motility, viability, and acrosomal membrane integrity of sperm at different concentrations (10, 15, 18, and 20 million sperm/straw) in 0.5-mL straws. Subsequently, we compared the pregnancy rates after AI with different sperm concentrations. Results: After freeze-thawing, sperm at the assessed concentrations showed similar viability and acrosomal membrane integrity. After AI, cattle in the 10 million group had significantly lower pregnancy rates compared to those in the 18 and 20 million groups. Conversely, there were no statistically significant variances observed between cattle in the 10 and 15 million groups. Conclusions: Sperm at concentrations of 10, 15, 18 and 20 million per straw exhibited comparable motility, viability, and acrosomal membrane integrity. However, a concentration of at least 18 million sperm per straw is required to achieve a consistent rate of pregnancy rate in Hanwoo cattle after AI.
        4,000원
        2.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Organoleptic parameters such as color, odor, and flavor influence consumer perception of drinking water quality. This study aims to evaluate the taste of the selected bottled and tap water samples using an electronic tongue (E-tongue) instead of a sensory test. Bottled and tap water's mineral components are related to the overall preference for water taste. Contrary to the sensory test, the potentiometric E-tongue method presented in this study distinguishes taste by measuring the mineral components in water, and the data obtained can be statistically analyzed. Eleven bottled water products from various brands and one tap water from I city in Korea were evaluated. The E-tongue data were statistically analyzed using multivariate statistical tools such as hierarchical clustering analysis (HCA), principal component analysis (PCA), and partial least squares discriminant analysis (PLS-DA). The results show that the E-tongue method can clearly distinguish taste discrimination in drinking water differing in water quality based on the ion-related water quality parameters. The water quality parameters that affect taste discrimination were found to be total dissolved solids (TDS), sodium (Na+), calcium (Ca2+), magnesium (Mg2+), sulfate (SO4 2-), chloride (Cl-), potassium (K+) and pH. The distance calculation of HCA was used to quantify the differences between 12 different types of drinking water. The proposed E-tongue method is a practical tool to quantitatively evaluate the differences between samples in water quality items related to the ionic components. It can be helpful in quality control of drinking water.
        4,200원
        6.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In light of recent social concerns related to issues such as water supply pipe deterioration leading to problems like leaks and degraded water quality, the significance of maintenance efforts to enhance water source quality and ensure a stable water supply has grown substantially. In this study, scan statistic was applied to analyze water quality complaints and water leakage accidents from 2015 to 2021 to present a reasonable method to identify areas requiring improvement in water management. SaTScan, a spatio-temporal statistical analysis program, and ArcGIS were used for spatial information analysis, and clusters with high relative risk (RR) were determined using the maximum log-likelihood ratio, relative risk, and Monte Carlo hypothesis test for I city, the target area. Specifically, in the case of water quality complaints, the analysis results were compared by distinguishing cases occurring before and after the onset of "red water." The period between 2015 and 2019 revealed that preceding the occurrence of red water, the leak cluster at location L2 posed a significantly higher risk (RR: 2.45) than other regions. As for water quality complaints, cluster C2 exhibited a notably elevated RR (RR: 2.21) and appeared concentrated in areas D and S, respectively. On the other hand, post-red water incidents of water quality complaints were predominantly concentrated in area S. The analysis found that the locations of complaint clusters were similar to those of red water incidents. Of these, cluster C7 exhibited a substantial RR of 4.58, signifying more than a twofold increase compared to pre-incident levels. A kernel density map analysis was performed using GIS to identify priority areas for waterworks management based on the central location of clusters and complaint cluster RR data.
        4,000원
        7.
        2023.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study aimed to provide fundamental data that could guide high school students' night eating behavior by investigating habits of their night eating consumption during COVID-19 pandemic (From 2021/5/13 to 5/20). Association between their eating habits and the Nutrition Quotient for Korean Adolescents (NQ-A) were also explored. This study included a total of 604 students, among whom 441 students were identified as night eating consumers. Among all subjects, 30.5% consumed night eating 3~4 times a week, 27.3% consumed 1-2 times a week, and 27.0% did not consume any night eating at all. The high-night eating group had a higher score of total NQ-A than the non-night eating group for both male (p<0.05) and female (p<0.001) students. This was because male students in the high-night eating group reported significantly higher rates of daily dinner consumption compared to non-night eating group. Furthermore, both male (p<0.05) and female (p<0.001) students showed a significant increase in ‘Moderation’. ‘Diversity’ was also significantly increased in female studies (p<0.05) as subcategories of dietary habits according to night eating frequency. These findings highlight the need for practical research to develop nutritional guidelines for night eating that reflect preferences of students while providing adequate nutritional habits.
        4,500원
        8.
        2023.05 구독 인증기관·개인회원 무료
        Radionuclide analysis methods must be secured in the event of emergencies such as the discovery of unknown nuclear material or nuclear accidents in neighboring countries or Korea. Most institutions in Korea are in their early stages of radionuclide analysis method development and do not even have Radiation Controlled Areas where they can handle the samples safely. Some institutions such as the Korea Atomic Energy Research Institute have the ability to perform radionuclide analysis for nuclear facilities or verification of nuclear activities. In Korea, it is necessary to secure nuclide analysis technology to enable independent verification in times of emergency or need. This paper analyzes uranium as the target nuclide using alpha spectrometer and TIMS. Alpha spectrometer detects alpha particles emitted from uranium samples and measures the concentration of uranium isotopes. This method has a high selectivity that distinguishes it from other elements, and accurate measurements can be made even when uranium samples are mixed with other elements. In addition, there is minimal interference from other radioactive isotopes in the sample, and the sample preparation is simple, resulting in relatively short analysis times. In contrast, TIMS detects ionized uranium ions by heating the uranium sample. This method may have potential interference from other elements and may take relatively longer analysis times. However, TIMS has high sensitivity and accuracy and can detect various elements other than uranium, making it suitable for various analyses. Therefore, when analyzing uranium, it is recommended to select and use the appropriate device according to the purpose, as both alpha spectrometer and TIMS have their pros and cons. Furthermore, by using both devices in parallel, more accurate and reliable results can be obtained. This paper aims to compare the analysis methods of alpha spectrometer and thermal ionization mass spectrometry, which are widely used for nuclide analysis in unknown nuclear materials.
        11.
        2019.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to evaluate vulnerability of drought in small island areas. Vulnerability assessment factors of drought were selected by applying the factor analysis. Ninety Eup/Myon areas in small island were evaluated to vulnerability of drought by entropy method adapting objective weights. Vulnerability consisted of climate exposure, sensitivity, and adaptive capacity. A total of 22 indicators were used to evaluate and analyze vulnerability of drought in small island areas. The results of entropy method showed that winter rainfall, no rainfall days, agricultural population rate, cultivation area rate, water supply rate and groundwater capacity have a significant impact on drought assessment. The overall assessment of vulnerability indicated that Seodo-myeon Ganghwa-gun, Seolcheon-myeon Namhae-gun and Samsan-myeon Ganghwa-gun were the most vulnerable to drought. Especially Ganghwa-gun should be considered policy priority to establish drought measures in the future, because it has a high vulnerability of drought.
        4,200원
        12.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Pressure retarded osmosis (PRO) processes can be implemented on a number of water types, using different technologies and achieving various power outcomes. In this study, Sewage facility effluent was used for feed solution of PRO and synthetic NaCl water for draw solution. This study was conducted to investigate effect of water quality of pretreatment on power density and flux decline in PRO process. The results show that organic and particulate foulants have to be removed for more stable operation. Flourescence technique with EEM enables to investigate the chemical properties of aquatic organic matter by extracting spectral information. Humic/fulvic matters and soluble microbial by-products were analyzed as the most affecting factors on the PRO performance. As a result of analyzing the whole system based on the energy consumption of the unit process, specific energy consumption(SEC) of the applicable technology for PRO pre-treatment should be about 0.2 kWh/m3 or less.
        4,000원
        13.
        2016.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Oxathiapiprolin은 병원균의 포자형성과 효모성장을 저해하여 노균병을 방제하는 piperidinyl thiazole isoxazoline 계열 살균제로 2015년 국내 사용등록이 요청된 신규약제이다. 본 연구에서는 oxathiapiprolin의 신규등록과 관련해 안전관리를 위한 공정시험법 마련이 요구되어 농산물 중 잔류분석법을 개발하였다. 농산물 중 oxathiapiprolin은 acetonitrile로 추출한 뒤 분배효율 향상을 위해 1 N sodium hydroxide (NaOH)를 이용해 염기성으로 조절하여 비해리상태로 만든 뒤 dichloromethane으로 액액분배하였으며 분배추출액은 silica SPE 카트리지로 정제한 뒤 HPLC-UVD로 분석하였다. 개발된 분석법의 검출한계(LOD) 및 정량한계(LOQ)는 각각 0.003, 0.01 mg/kg이었고, 대표농산물 5종(고추, 감귤, 감자, 대두, 현미) 중 oxathiapiprolin의 평균 회수율은 86.7-112.7%(상대표준편차, RSD ≤ 10%)으로 나타났다. 이는 잔류물 분석에 관한 CODEX 가이드라인 (CAC/GL 40)을 만족하는 것으로 확인되었다. 따라서 개발된 분석법은 국내외 유통 농산물 중 oxathiapiprolin의 안전평가를 위한 잔류량 적부 판정에 있어 공정시험법으로 사용되기에 적합할 것으로 판단된다.
        4,000원
        14.
        2014.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구의 첫 실험에서는 발근제 처리가 ‘Bluecrop’, ‘Duke’, ‘Sunrise’ 하이부시 블루베리 품종의 숙지삽 발근과 추후 생장에 미치는 영향을 조사하였다. 삽수의 기부 1-cm에 IBA와 NAA 0, 500, 1000mg · L−1 용액에 5초간 침지하였고 또한 루톤 분제도 처리하였다. 삽목 90일 후 ‘Bluecrop’과 ‘Sunrise’품종의 발근율과 근중은 NAA 500mg · L−1 처리에 의해서 증가한 반면 ‘Duke’ 품종에서는 IBA 500mg · L−1가 뿌리 생장에 효과적이었다. 이러한 발근제 처리에 의한 삽수 부정근의 초기 발달에서 증가는 개별포트에서 추후 생육의 증가로 이어졌다. 두 번째 실험에서는 삽상의 차광처리(30~90%)가 위 블루베리 품종들의 숙지삽의 발근과 생장에 미치는 영향을 조사하였다. 30% 차광은 무차광 대조구와 비교했을 때 모든 품종에서 발근율, 뿌리와 줄기의 생장을 증가시켰다. 그러나 특별히 분무시설이 없는 삽상에서 차광을 50% 이상으로 했을 때 하이부시 블루베리의 숙지삽의 발근과 생장은 상당히 억제되었다.
        4,000원
        15.
        2020.12 KCI 등재 서비스 종료(열람 제한)
        백두산 북동쪽으로 약 25 km 떨어져있는 지역의 마이오세 현무암(황송푸 현무암, 20 Ma)에 대한 주 성분원소와 미량원소, Sr-Nd 동위원소 조성에 대한 연구가 수행되었다. 황송푸 현무암은 비현정질 암석으로 Na2O+K2O=3.5~4.7 wt.%, MgO=9.9~11.1 wt.%을 보인다. Mg 성분이 풍부한 감람석(Mg#=75~86)과 단사휘석 (Mg#=72~85), Ca성분이 풍부한 사장석 미반정을 함유하고 있다. 이 현무암은 경희토류원소 부화가 나타나는 해양도현무암과 유사한 미량원소 패턴을 보이고, 높은 Cr(394~479 ppm)과 Ni(389~519 ppm) 성분, Nb-Ta 부화 이상치, Rb과 Ba을 포함하는 LILE가 부화되어 있는 특징을 보인다. 이러한 조직과 주성분원소/미량원소 조성 데이터는 황송푸 현무암이 알칼리 마그마 계열에 속하는 원시적인 마그마임을 나타낸다. 황송푸 마그마는 상승하는 도중에 분별결정작용, 지각오염, 마그마혼합과 같은 분화작용을 거의 경험하지 않은 액상선 환경 에서 고화된 암석으로 이는 황송푸 현무암이 부분용융이 일어났던 맨틀에서의 특성을 지니고 있음을 반영한다. 황송푸 현무암의 높은 (Gd/Yb)sample/(Gd/Yb)PM 비율(2.8~3.5)은 황송푸 현무암이 판내부 환경에서 형성된 마그마로써 석류석이 존재하는 맨틀에서 페리도타이트의 낮은 부분용융(3~5%)으로 형성되었다. BSE보다 모두 높은 143Nd/144Nd와 87Sr/86Sr 성분을 보이는 황송푸 현무암은 이 지역 아래 부화된 맨틀영역이 존재한다는 것을 의미한다. 황송포 현무암은 과거(ancient)의 태평양판 섭입대에 의해 공급되어 재활용된 해양지각 혹은 대륙지각으로 교대작용을 경험한 맨틀에서 부분용융에 의해 형성되었다.