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        검색결과 235

        61.
        2012.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Since the Bovine sequencing and HapMap projects, there have been millions of genetic variations particularly including single nucleotide polymorphisms (SNPs) available throughout the cattle genome. While cataloguing substantial amounts of SNPs, copy number variation (CNV) has recently become getting great attention as an another form of genetic variation which is extensively distributed across the cattle genome. As it has been well known that CNVs can account for substantial proportions of phenotypic variance in other species including human, CNVs are highly expected to explain genetic variations of diverse economically important traits in cattle. Currently, two main approaches such as hybridization-based microarray and massively parallel sequencing-based method have been successfully applied to detect CNVs throughout the cattle genome. Although there is obvious difference of capabilities to detect genome-wide CNVs at fine scales between different platforms applied, all currently completed investigations exhibited that CNVs are extensively spread throughout the cattle genome as observed in other species. Despite these successes, there are still severe lacks of researches to identify multiple levels of CNVs from diverse cattle or multiple individuals, suggesting that there are a number of CNVs remained undiscovered. Furthermore, there are almost few investigations available to elucidate how each CNV is associated with traits of interest in cattle, so such functional study should be followed along with saturating most of potential CNVs on cattle genome.
        4,000원
        62.
        2012.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was carried out to investigate the effect of wormwood meal addition on constituent of blood, and liver fatty acid in broiler chickens. Two-day old 25 male commercial broiler chicks were distributed to 5 treatments (wormwood meal levels ; T1 (1%), T2 (3%), T3 (5%), T4 (10%), and control (C)) for 5 weeks. Free fatty acids of liver were a little different among the treatments and the palmitic, stearic, oleic, and linoleic acids were occupied 92.5% of total free fatty acids. Hemoglobin and hematocrite concentration of blood were significantly decreased (p<0.05) as the levels of wormwood meal increased, and serum albumin concentration of broilers was little different between 0 week and 5 week experiments. Also serum cholesterol, phospholipid, total cholesterol, and triglyceride concentration of liver in broilers were little different during the 5 weeks experiment. Serum triglyceride concentration was significantly increased (p<0.05) as levels of wormwood meal increased. These results indicate that dietary wormwood meal addition has a little positive effect on increasing unsaturated fatty acid and decreasing saturated fatty acid.
        4,000원
        63.
        2012.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Stearoyl-CoA desaturase (SCD1) gene plays important role in fatty acid composition. In order to find marker-assisted selection (MAS) for improving the economic trait, this study was performed to identify the 878T>C single nucleotide polymorphism (SNP) on SCD1 gene. Three genotypes (CC, CT, and TT) were detected in 878T>C SNP of SCD1 gene from 103 Hanwoo population by polymorphism chain reaction-restriction fragment length polymorphism (PCR-RFLP) and economic traits were analyzed by general linear model. The frequency of allele C and T was 0.534 and 0.466, also the genotype frequency of CC, CT and TT was 0.252, 0.563, and 0.184, respectively in the Hanwoo population. The TT genotype of SCD1 gene showed a significantly higher measures (p<0.05) of carcass weight (CW) than CT, CC genotype. No significant association was detected between genotype and other economic trait (marbling, backfat thickness, and longissimus muscle area) in this study. The results revealed that SCD1 gene 878T>C SNP could be useful for effective MAS to increase the economic quality in Hanwoo population.
        4,000원
        65.
        2012.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study compares the abundance and community structure of zooplankton organisms from the littoral and pelagic regions, and considers particularly trophic levels vs. zooplankton abundances. Zooplankton samples, collected every 3 months over a year from 2010 to 2011 at 29 temperate lakes and reservoirs, which belong to two different river basins (Youngsan and Seomjin River). The spatial pattern of rotifers was similar to that of total zooplankton abundance. This reflected the fact that rotifers strongly dominated the zooplankton community. There were considerable spatial variations in total zooplankton abundance (ANOVA, p<0.01), while there were no significant differences both in littoral and pelagic regions in abundance of zooplankton (ANOVA, p=0.205). The mean abundance of zooplankton in eutrophic systems was much higher than that of mesotrophic systems, while significant difference in number of species and diversity index were not shown in both trophic systems.
        4,000원
        66.
        2012.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        2011년 영산강∙섬진강 수계 29개 호소조사에서 동정된 식물플랑크톤은 규조강 161종, 녹조강 157종, 남조강 39종, 기타 67여종으로 총 424종이었다. 조사기간 동안 4차 조사시기에 상대적으로 더 다양한 종이 출현하였으며 대동호, 대동제, 소포제, 군곡제, 개초제, 둔전제 지점에서 다양한 종들이 출현하였고, 영산호를 비롯한 하천형 호소에서는 비교적 빈약한 종이 출현하였다. 각 지점에서 20% 이상의 우점율을 보인 종은 대부분 규조류였고 2차와 3차 조사에서 녹조류와 남조류도 우점의 빈도가 높아졌다. 개체군 밀도는 조사 호소나 시기에 따른 뚜렷한 패턴이 없었고 특정 종의 성장에 크게 의존하는 특성을 나타냈다. 클로로필-a의 농도는 조사호소와 시기에 따른 편차가 매우 컸으며 식물플랑크톤의 개체수와 일치하지 않는 것으로 나타났다. 총질소와 총인의 농도와 클로로필-a의 농도 사이에는 매우 낮은 상관성이 나타났다.
        4,000원
        67.
        2012.03 구독 인증기관 무료, 개인회원 유료
        This study was carried out to investigate artificial insemination (AI) failure status and frozen semen characteristics in Korean proven bulls‘ number (KPN) semen used for AI of Hanwoo cows in Gangwon East region (Gangneung, Donghae, Taebaek, Samcheok, Sokcho, Yangyang, Goseong). Among semen used for AI, AI failure rate showed lowest at KPN506 (27.6%), whereas highest at KPN593 (77.2%). Correlations of AI failure in between Korean proven bulls semen and cows was 0.2941, which means that AI failure rate of Korean proven bulls semen may have respectable effect on reproduction of Hanwoo cow. In addition, present study was conducted to investigate spermatozoal viability rate, ruptured acrosome rate and active mitochondria in frozen Korean proven bulls semen with flow cytometry. The semen of KPN593 showed significantly (p<0.05) higher viability rate in KPN593 (30.49%) than that in KPN637 (37.34%). Furthermore, percentage of ruptured acrosome was lower in KPN637 as 21.37% than in KPN637 (21.37%), but it was not statistically significant. In conclusion, these results indicate that choice of Korean proven bulls semen may correlate positively with conception rate in Hanwoo cow. Therefore, KPN with high AI failure rate might be avoid to increase conception rate and characteristics of frozen semen might be evaluated before its use for AI.
        4,000원
        68.
        2012.01 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        In2O3 films were deposited by RF magnetron sputtering on a glass substrate and then the effect of post depositionannealing in nitrogen atmosphere on the structural, optical and electrical properties of the films was investigated. Afterdeposition, the annealing process was conducted for 30 minutes at 200 and 400oC. XRD pattern analysis showed that the asdeposited films were amorphous. When the annealing temperature reached 200-400oC, the intensities of the In2O3 (222) majorpeak increased and the full width at half maximum (FWHM) of the In2O3 (222) peak decreased due to the crystallization. Thefilms annealed at 400oC showed a grain size of 28nm, which was larger than that of the as deposited amorphous films. Theoptical transmittance in the visible wavelength region also increased, while the electrical sheet resistance decreased. In this study,the films annealed at 400oC showed the highest optical transmittance of 76% and also showed the lowest sheet resistance of89Ω/□. The figure of merit reached a maximum of 7.2×10−4Ω−1 for the films annealed at 400oC. The effect of the annealingon the work-function of In2O3 films was considered. The work-function obtained from annealed films at 400oC was 7.0eV. Thus,the annealed In2O3 films are an alternative to ITO films for use as transparent anodes in OLEDs.
        4,000원
        69.
        2011.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 고내구성을 가진 고분자 전해질 막을 제조하는 것으로 연료전지에 적용하기 위하여 poly(vinyl alcohol)를 주쇄부로 하여 poly(styrene sulfonic acid-co-maleic acid) (PSSA-MA)와 3-(trihydroxysilyl)-1-propanesulfonic acid (THS-PSA)를 polyethylene막에 함침시켜 막을 제조하였다. 제조된 막을 함수율, 접촉각, FT-IR, 수소이온전도도, 탄성계수 등의 측정을 통해 친수성 고분자가 함침된 막의 특성평가를 실시하였다. FT-IR 분석과 접촉각 측정을 통해 PE막에 함친된 막에서 친수성기의 유무를 확인하였다. 수소이온전도도를 측정한 결과 30% THS-PSA의 막이 55℃에서 1.27×10 ­1S/㎝의 값을 나타내어 우수한 수소이온전도도를 나타내었으며, 탄성계수의 측정을 통해 polyethylene막에 비하여 THS-PSA가 함침된 막의 기계적 강도가 15%까지는 최대 7배까지 향상되어 막의 내구성이 향상되었음을 확인하였다.
        4,000원
        70.
        2011.08 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The industrial manufacturing of YSZ products can be summarized as a three step process: a) hydrolysis of zirconyl chloride and mixing of other solutions, b) precipitation, and c) calcination. The addition of ammonia or OH- is essential in the precipitation process. However, a strong agglomeration was observed in the results of an ammonia or OH- addition. Thus, it is necessary to disperse the powders smoothly in order to improve the mechanical strength of YSZ. In this study, YSZ was synthesized using the urea stabilizer and hydrothermal method. YSZ powders were synthesized using a hydrothermal method with Teflon Vessels at 180˚C for 24 h. The mole ratio of urea to Zr was 0, 0.5, 1, and 2. The crystal phase, particle size, and morphologies were analyzed. Rectangular specimens (33 mm×8 mm×1±0.5 mm) for three-point bend tests were used in the mechanical properties evaluation. The crystalline of YSZ powders observed a tetragonal phase in the sample with a ratio of Zr:urea = 1:2 addition and a hydrothermal reaction time of 24 h. The average primary particle size of YSZ was measured to be 9 nm to 11 nm. The agglomerated particle size was measured from 15 nm to 30 nm. The three-point bending strength of the YSZ samples was 142.47 MPa, which is the highest value obtained for the Zr:urea = 1:2 ratio addition YSZ sample.
        4,000원
        71.
        2011.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        2010년 영산강 섬진강 수계의 29개 호소 45개 지점의 환경조사에서 동정된 식물플랑크톤은 총 371종으로 규조강과 녹조강이 주를 이루었다. 호소의 규모와 식물플랑크톤의 분포 양상 사이에 상관성이 거의 없는 것으로 나타났다. 호소의 유역면적과 식물플랑크톤 현존량은 상관성을 보이지 않았고, 유역면적과 출현종수 사이에도 상관성이 매우 낮았다. 수표면적과 식물플랑크톤 출현종수와 현존량 사이에는 낮은 상관성이 나타났다. 본 조사 호소들에서 호소의 규모와 식물
        4,000원
        72.
        2011.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 다공성 polyethylene (PE) 이차전지용 격리막에 poly(ethylenimine) (PEI)을 함침시켜 isophthaloyl dichloride (IPC)을 이용한 가교반응 통하여 음이온교환막을 제조하였다. 제조된 막의 특성화를 평가하기 위하여 함수율, 접촉각, FT-IR, 이온교환용량, 이온전도도 등을 측정하였다. PEI와 IPC의 반응은 아민과 -COCl기와의 반응으로 아마이드기가 생성된다. 이온교환용량의 경우 30초 반응에서 1.96 meq./g dry membrane부터 600초 반응으로 인한 1.14 meq./g dry membrane까지 감소하는 경향을 나타내었고, 이온전도도의 경우 IPC와의 가교시간이 30초일 때 9.15×10-2S/㎝의 높은 값을 나타냄을 확인할 수 있었다.
        4,000원
        73.
        2011.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        새만금호의 염습지에 위치한 갯벌 5 지점에서 동정된 부착조류는 5강의 44종이었으며 규조류가 33종으로 가장 다양한 조성을 나타냈다. 2007년 이후 연도별 출현종수에서는 전체적으로 큰 차이가 없는 것으로 나타났다. 출현종 수가 가장 크게 변동한 곳은 D1 지점으로 2009년에는 전년에 비해 2배 이상의 종이 출현하였다. 부착조류 개체수는 대부분 규조류에 의한 것이었다. 세포수와 생물량은 2009년에 가장 높았으며, D1과 D2 지점에 서는 큰 증가를
        4,000원
        74.
        2011.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        함평만 갯벌에 출현한 저서규조류는 총 45종이었으며 Paralia sulcata가 가장 우점하는 것으로 나타났다. 출현종 분포에서는 전 지점에서 4월에 가장 다양했고 1월에 가장 단순한 종조성을 나타냈으나 큰 차이가 없는 것으로 나타나 고온기의 높은 다양도는 볼 수 없었다. 표층 퇴적물 시료의 chlorophyll a 농도는 19.7~35.2 mg m-2이었고 평균 28.7 mg m-2로 나타났다. 표층 퇴적물 내 pheopigment
        4,000원
        75.
        2010.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        ZnO thin films were prepared on a glass substrate by radio frequency (RF) magnetron sputtering without intentional substrate heating and then surfaces of the ZnO films were irradiated with intense electrons in vacuum condition to investigate the effect of electron bombardment on crystallization, surface roughness, morphology and hydrogen gas sensitivity. In XRD pattern, as deposited ZnO films show a higher ZnO (002) peak intensity. However, the peak intensity for ZnO (002) is decreased with increase of electron bombarding energy. Atomic force microscope images show that surface morphology is also dependent on electron bombarding energy. The surface roughness increases due to intense electron bombardment as high as 2.7 nm. The observed optical transmittance means that the films irradiated with intense electron beams at 900 eV show lower transmittance than the others due to their rough surfaces. In addition, ZnO films irradiated by the electron beam at 900 eV show higher hydrogen gas sensitivity than the films that were electron beam irradiated at 450 eV. From XRD pattern and atomic force microscope observations, it is supposed that intense electron bombardment promotes a rough surface due to the intense bombardments and increased gas sensitivity of ZnO films for hydrogen gas. These results suggest that ZnO films irradiated with intense electron beams are promising for practical high performance hydrogen gas sensors.
        3,000원
        76.
        2010.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 음이온교환막 개발에 관한 것으로 poly(ethylenimine) (PEI) / poly(vinyl alcohol) (PVA)의 혼합비율에 따라 막을 제조하였다. 제조된 막의 특성화를 평가하기 위하여 함수율, 접촉각, FT-IR, 이온교환용량, 이온전도도, 열 중량분석, 탄성계수 측정을 실시하였다. 이온전도도 측정 결과 PVA/PEI의 함량이 90 : 10으로 제조된 막의 경우 5.16 × 10 -2 S/cm의 값을 나타내어 우수한 음이온전도도를 나타내었으며 접촉각 측정 결과 PEI의 함량이 증가함에 따라 막표면의 소수성이 78.3℃까지 함께 증가하는 결과를 나타내었다. 또한 열에 대한 안정성은 PVA의 우수한 성질을 변화시키지 않았으며 탄성계수 측정을 통해 고강도 기계적 물성을 확인할 수 있었다.
        4,000원
        77.
        2010.10 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        In this study, partially stabilized zirconia was synthesized using a chemical Y2O3 stabilizer and hydrothermal method. First, YCl3-6H2O and ZrCl2O-8H2O was dissolved in distilled water. Y-TZP (a Y2O3-doped toughened zirconia polycrystalline precursor) was also prepared by conventional co-precipitates in the presence of an excess amount of NH4OH solution under a fixed pH of 12. The Y-TZP precursors were filtered and repeatedly washed with distilled water to remove Cl- ions. ZrO2-Xmol%Y2O3 powder was synthesized by a hydrothermal method using Teflon Vessels at 180˚C for 6 h of optimized condition. The powder added with the Xmol%- Y2O3 (X = 0,1,3,5 mol%) stabilizer of the ZrO2 was synthesized. The crystal phase, particle size, and morphologies were analyzed. Rectangular specimens of 33mm×8mm×3 mm for three-point bend tests were used in the mechanical properties evaluation. A teragonal phase was observed in the samples, which contains more than 3 mol% Y2O3. The 3Y-ZrO2 agglomerated particle size was measured at 7.01μm. The agglomerated particle was clearly observed in the sample of 5 mol % Y2O3-ZrO2, and and the agglomerated particle size was measured at 16.4 um. However, a 20 nm particle was specifically observed by FE-SEM in the sample of 3 mol% Y2O3-ZrO2. The highest bending fracture strength was measured as 321.3 MPa in sample of 3 mol% Y2O3-ZrO2.
        4,000원
        78.
        2010.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 국내 31개 호소 지점을 대상으로 동식물플랑크톤 생체량 및 생태학적 모델 적용을 고려한 호소간의 플랑크톤 동태 비교에 목적이 있다. 조사기간 동안 총 89종의 동물플랑크톤(윤충류 70종, 지각류 14종, 요각류 5종)과 554종의 식물플랑크톤(규조류 176종, 녹조류 237종, 남조류 68종 그리고 기타 73종)이 동정 확인 되었다. 플랑크톤 밀도 및 종 다양도는 지점별 및 계절별 상이한 차이를 나타내었다. 전체 호소의 연평균 총 식물플랑크톤
        4,000원
        79.
        2010.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to show the odor emission characteristics between the well maintained environment fundamental facility and the poorly maintained environmental facility. It also draws major components of odor emission based on facilities, stages, and suggest the proper way to reduce the level of odor for insufficient facilities. Insufficient facilities" air direct sensory and air dilution value levels are following: foodwaste > livestock > wastewater > night-soil > sewage. For the sewage and waste water facilities, the common characteristic of odor emission on each fundamental facility showed higher air dilution value in depositing reservoir and concentrator. And sulfur and aldehyde compounds came out to be the major odor causing components. In the case of night-soil and livestock facilities, the air dilution value was high in flow equalization tank and liquid erosion tank. And sulfur as well as ammonia component was the major malodorous substance. Foodwaste facility showed higher air dilution value than other facility, which sulfur and acetaldehyde compounds were acting as major malodorous substances.
        4,000원
        80.
        2010.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
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        4,000원
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