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        검색결과 29

        1.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Injection molding is a process of shaping resin materials by heating them to a temperature above their melting point and then using a mold. The resin material is injected into and cooled within the mold cavity, solidifying into the desired shape. The core and cavity components that make up the mold cavity are crucial elements for the precision molding in injection molding. In the case of precision mold production, the application of 5-axis machining technology is required to ensure high machining quality for complex shapes, and among these factors, the tool angle is a critical machining condition that determines the surface roughness of the workpiece. In this study, we aim to measure the surface roughness of the machined surface of KP4A specimens during machining processes with variations in the tool angle and analyze the correlation between the tool angle and surface roughness.
        4,000원
        3.
        2023.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        3D printing is widely used in product development and prototype manufacturing, and is expected to become universal across various industries with the development of 3D printing-related technologies. However, parts made by Fused Deposition Modeling(FDM) 3D printing using the commonly used stacking manufacturing process, show low tensile strength and hardness. The decreased mechanical properties of these parts limit their use as structural elements. In this study, we aim to investigate the relationship between ultrasonic treatment of PLA parts produced by FDM 3D printing and their mechanical properties. Specifically, we analyze the effects of ultrasonic annealing on the mechanical properties of PLA parts using the tensile test specimen.
        4,000원
        4.
        2022.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Canine parvovirus type-2 (CPV-2) is a major etiological agent causing gastrointestinal enteritis in domestic and wild carnivores. Since the emergence of CPV-2 in the late 1970s, subtypes CPV-2a, CPV-2b, and CPV-2c have spread worldwide. CPV-2 prevalence differed according to region and season. This study aims to investigate the prevalence of CPV-2 infection in Korea. Samples were collected from 536 dog feces in animal shelters and 225 necropsied intestinal tissues of dog carcasses submitted in the Animal and Plant Quarantine Agency (APQA) for diagnostic purposes from 2016 to 2020 in Korea. Among the 761 samples, 181 (23.8%) were positive for the following subtypes: CPV-2a (n=138), CPV-2c (n=16), CPV-2b (n=14), and CPV-2 (n=2). Feline parvovirus (n=2) and co-infection with CPV-2a and CPV-2c (n=1) were also detected. There was no significant difference in the regional distribution of CPV-2 in Korea, which is prevalent in winter. This result shows the prevalence of CPV-2 according to various environments in Korea and will be useful in establishing an effective prevention strategy against CPV-2 that reflects the situation in Korea with continuous monitoring.
        4,000원
        5.
        2022.05 구독 인증기관·개인회원 무료
        An application of the final decommissioning plan for unit 1 of Kori NPP was submitted to NSSC on 14 May 2021. We have been implementing the project related to the radiological characterization for the plan since 2019. However, the project was not running smoothly due to the regulatory environment. The destructive sampling from the objects was not allowed, so only smear (swipe) samples are available. In this study, the sampling way and the analytical results of radionuclides are presented. In addition, we propose in-situ measurement using gamma camera and in-situ gamma spectroscopy to obtain more comprehensive radiological information on the object.
        6.
        2020.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 천연 기능성 소재인 비파잎의 첨가가 흑염소고기 저지방 소시지의 품질특성 및 항산화 활성에 미치는 영향을 알아보기 위하여 실시하였다. 20% 지방을 첨가한 대조구(control), 10% 지방을 첨가한 처리구(LF), 10% 지방과 0.25% 비파잎분말을 첨가한 처리구(LL)로 처리하였다. 저지방 소시지인 LF, LL은 대조구보다 지방함량은 낮고, 수분과 단백질 함량은 높았고, 보수력도 향상되었다(p<0.05). 육색의 경우 비파잎을 첨가한 LL은 적색도와 황색도가 감소하였고(p<0.05), TPA에서 탄력성, 검성, 씹힘성 및 응집성은 LF보다 증가하였고, 대조구와 유사한 조직감을 갖는 것으로 나타났다(p<0.05). TBARS와 DPPH radical 소거능은 비파잎을 첨가한 LL에서 우수한 항산화 활성을 나타냈다. 따라서 기능성 소재인 비파잎을 첨가한 흑염소고기 저지방 소시지는 고단백, 저지방 특성의 흑염소고기 섭취 기회를 늘려줌과 동시에 건강 지향적 육제품 개발의 기초자료로 활용될 수 있다.
        4,000원
        7.
        2020.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 착즙이나 추출 후 폐기되는 복분자(Rubus coreanus) 부산물을 사료자원으로 급여한 버크셔 암컷과 거세돈의 육질특성을 알아보고자 실시하였다. 시험 돼지는 Berkshire 품종 총 60두를 암수 구분하여 각 15두씩 임의 배치하였고, 복분자 부산물을 급여하지 않은 대조구와 복분자 부산물을 전체 사료의 0.3% 수준으로 출하 전 60일간 급여한 처리구(RC)로 분리하였다. 육질분석을 위하여 도축 후 예비 냉각한 좌반도체 등심 부위를 채취하여 일반성분, 이화학적 육질특성, 지방산 및 항산화 활성을 분석하였다. 일반성분은 대조구와 RC간의 유의적 차이가 없었고, 육색에서 거세돈육의 명도(L*) 값에서만 RC구에서 대조구 보다 낮은 값을 나타냈다(p<0.05). 등심육의 pH와 보수력은 RC 급여에 의한 유의적 차이가 없었으나, 전단력에서는 RC에서 유의적으로 높은 값을 나타냈다(p<0.05). TBARS 수치는 거세돈육의 RC가 대조구에 비해 낮은 경향을 나타냈고, DPPH radical 소거활성에서도 거세돈육의 RC가 대조구보다 높은 항산화능을 나타냈으나 유의적인 차이는 없었고 이는 성별에 의한 차이가 큰 것으로 판단된다. 근내지방 함량과 지방산 조성은 RC 급여에 의한 영향보다는 성별에 의한 차이가 뚜렷하게 나타났으며, RC 급여에 따른 항산화 특성 패턴이 다르게 나타난 것도 위와 같은 이유인 것으로 판단된다.
        4,000원
        8.
        2020.08 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        우리는 실험과 MCNP 시뮬레이션을 통해 전알파 분석법의 한계를 설명하였다. 국내에서 중·저준위 방사성폐기물 인도 규 정 관련, 전알파 분석법은 방사성폐기물을 처분하기 위해 반드시 규명해야 할 방사성 특성평가 인자이다. 전알파 분석법은 시료 준비 절차가 간단하고 신속한 분석 결과를 제공하지만, 정량분석 인자로 사용하는 것은 적절하지 않다. KCl과 241Am 을 이용하여 시편 건조고형물 무게에 따른 전알파 계측효율을 평가하였다. 동일한 무게의 시편일지라도 계측효율의 차이가 20% 나는 것을 확인하였고, 이는 시편의 물리적 형태가 서로 다르기 때문인 것으로 보인다. 토양 중 우라늄을 화학분리 한 후, ICP-MS로 우라늄을 직접 측정한 결과와 전알파 농도를 비교하였다. 전알파는 실제 우라늄 농도에 비해 50% 과소평가되 었다. 알파핵종별 전알파 계측효율이 최대 3배 차이 나기 때문에, 전알파 분석결과는 개별 알파핵종의 합과 비교하기 보다는 스크리닝 개념으로 사용하는 것이 적절하다.
        4,000원
        9.
        2020.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The experiment was undertaken to measure the potential impact of animal welfare on the pork quality under two different farming systems: C1 and C2, two conventional farms; W, an animal welfare farm. Ten pigs (Landrace × Yorkshire × Duroc) of live weight 110 kg were randomly selected from each treatment, and slaughtered under uniform conditions. The left loins were collected, and subsequently analyzed for proximate composition, meat quality traits, fatty acids, free amino acids, and antioxidative dipeptides. Pork from the welfare farm (W) had greater back-fat depth and fat content, but the values were not significantly different from C1 or C2. The W loins had significantly lower moisture contents and pH values compared to C1 or C2. The C2 loins showed highest contents of unsaturated fatty acids, whereas C1 had higher polyunsaturated fatty acids as compared to W. The treatments did not show any significant differences in the contents of free aspartic acid. Anserine (an antioxidant dipeptide) from the W loins was significantly lower than that from the conventional farms. The results indicate that pork quality characteristics from animal welfare-farmed pigs were not different from those of conventional farms. Therefore, it would be appropriate to evaluate the industrial value of animal welfare livestock only at the stage of pig production, rather than the meat quality of pork.
        4,500원
        10.
        2019.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Chironomid communities are indicators of water pollution because of their ability to thrive under freshwater conditions. However, it is difficult to distinguish between chironomid larvae based on morphology. DNA barcoding, based on nucleotide sequences of marker genes, can be used to identify chironomid larvae. Samples of chironomid larvae were collected from Gwangju Stream and Pungyeongjeong Stream, tributaries of the Yeongsan River in South Korea. We identified 3 subfamilies, 13 genera, 16 species, and 1 cryptic species. There were 7 genera and 10 species from the subfamily Chironominae, 5 genera and 5 species from subfamily Orthocladiinae, 1 genus and 1 species from subfamily Tanipodinae, and the cryptic chironomid species of the family Chironomidae. There were 21 individuals from, 7 species and 1 cryptic species from the Gwangju Stream and 24 individuals, belonging to 10 species from the Pungyeongjeong Stream. The only species detected in both streams was Cricotopus bicinctus. The relationship between water quality and the species detected was difficult to explain, but the number of species showed a tendency to increase at sites where water quality was poor. Additional investigations and studies are needed to understand the relationship between water quality and the chironomid species occurring in these two streams.
        4,000원
        16.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The properties of rice were studied on five rice cultivars (Ilpumbyeo, Samkwang, Goami-4, Dodamssal, and Thai rice), and employed two kinds of saccharification treatment methods (treatment : rice shape, treatment II: grinding rice shape). Thai rice showed differences in width and length when compared to other cultivars of rice, and the Goami 4 had the lowest thousand-grain weight. The Goami4 and Dodamssal each showed high contents of amylose and resistant starch, and the water absorption rate was close to maximum at 90 minutes as well as the highest level of Goami 4 at all times. The qualities of highest water-binding capacity, solubility and swelling power was most significant in Thai rice. The lowest hardness level of wet rice resulted in the lowest hydration-related characteristics. High amylose content rice, in particular, showed low sugar content and slightly increased sugar content as the saccharification process improved (treatment II). On the other hand, high amylose cultivars had the same high degree of hardness as boiled rice. From these results, the Dodamssal was found to have the lowest viscosity at all temperatures but highest viscosity during the saccharification process, suggesting it may be successfully implemented as a thickener in rice beverage processing. The purpose of this study was to attempt to provide basic data on the development of rice beverage manufacturing technology, based upon the quality characteristics related to beverage processing of rice cultivars.
        4,000원
        17.
        2017.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, we divided the process operation scenarios into three categories based on raw water temperature and turbidity. We will select and operate the process operation scenario according to the characteristics of the raw water. The number of algae in the DAF treated water has been analyzed to be less than 100 cells/mL. These results indicated that the DAF process is effective in removing the algae. In addition, the scenario of the integrated management decision algorithm of the DAF process was developed. DAF pilot plants (500 m3/day) process has shown a constantly sound performance for the treatment of raw water, yielding a significantly low level of turbidity (DAF treated water, 0.21~1.56 NTU).
        4,000원
        18.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was carried out to obtain useful information on the cost-effective and labor-saving methods in the on-farm pigmented rice cultivation trials that were performed in Gangjn, Jindo and Gimje provinces. Two different pigmented rice cultivars were tested at each site from 2014 to 2015. From the common rice transplant technologies, Wet Hill Direct Seeding Technology (WHDST) was applied and was compared to Transplanting Machine (TM) Technology, which was mainly used for rice transplanting. The results of the study showed that during the trial period, the average C3G contents of pigmented rice ‘Heugkwang’ in Gangjin was 145.5 mg/100g using the WHDST. This was 23.5 mg/100g higher than using TM in Gangjin area. On the other hand, the C3G contents of functional pigmented rice variety ‘Seonhyangheukmi’ was 163 mg/100g under the WHDST while 189.3 mg/100g under the TM. Therefore, it was observed that the C3G contents of functional pigmented rice changed depending on the variety and according to the annual environmental variation. In Jindo area, two years average C3G contents of functional pigmented rice variety ‘Josaengheugchal’ was resulted to 268.1 mg/100g using TM. This C3G contents was 97.8 mg/100g more than the amount obtained using WHDST. For functional pigmented rice variety ‘Shinnongheugchal’, the C3G contents was 247.3 mg/100g in the WHDS, while 249.1 mg/100g in the TM. This indicated that C3G contents tended to be similar based on cultivation method. The C3G contents of the rice variety ‘Heugkwang’ in Gimje area were 34.7 mg/100 g and 20.2 mg/100g using WHDST and TM, respectively. Meanwhile, the C3G contents of functional pigmented rice variety ‘Heugsujeong’ was 85.6 mg/100g in the WHDST and 43.62 mg/100g in the TM. In conclusion, the study showed that the C3G contents of the pigmented rice are affected by the yearly environmental variation, the regions, and the cultivated variety.
        4,000원
        19.
        2010.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        이 연구는 형질전환 고추로부터 토양 근권 미생물로의 유전자 이동 가능성을 조사하기 위해 수행되었다. 재배중인 오이 모자이크 바이러스 저항성 고추와 대조구의 근권토양으로부터 DNA를 추출한 후 형질전환 고추 도입유전자에 특이적인 프라이머를 사용하여 PCR 분석을 수행하였다. PCR 결과 도입유전자인 NPTII 유전자가 수집된 전 기간의 근권 토양 샘플에서 발견되었다. 발견된 도입유전자가 고추로부터 토양 미생물로의 유전자 이동에 의한 결과인지를 조사하기 위하여 토양 샘플로부터 미생물들을 분리하여 카나마이신이 첨가된 세균 및 진균 배지에 배양하였다. 약 43만개의 세균 코로니와 16만개의 진균 코로니를 조사 한 결과 카나마이신에 저항성을 나타내는 개체는 발견되지 않아 형질전환 고추로부터 근권 미생물로의 유전자이동은 발생하지 않은 것으로 사료되었다.
        4,000원
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