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        검색결과 38

        1.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        High-entropy alloys (HEAs) have been reported to have better properties than conventional materials; however, they are more expensive due to the high cost of their main components. Therefore, research is needed to reduce manufacturing costs. In this study, CoCrFeMnNi HEAs were prepared using metal injection molding (MIM), which is a powder metallurgy process that involves less material waste than machining process. Although the MIM-processed samples were in the face-centered cubic (FCC) phase, porosity remained after sintering at 1200°C, 1250°C, and 1275°C. In this study, the hot isostatic pressing (HIP) process, which considers both temperature (1150°C) and pressure (150 MPa), was adopted to improve the quality of the MIM samples. Although the hardness of the HIP-treated samples decreased slightly and the Mn composition was significantly reduced, the process effectively eliminated many pores that remained after the 1275°C MIM process. The HIP process can improve the quality of the alloy.
        4,300원
        2.
        2023.05 구독 인증기관·개인회원 무료
        Natural uranium-contaminated soil in Korea Atomic Energy Research Institute (KAERI) was generated by decommissioning of the natural uranium conversion facility in 2010. Some of the contaminated soil was expected to be clearance level, however the disposal cost burden is increasing because it is not classified in advance. In this study, pre-classification method is presented according to the ratio of naturally occurring radioactive material (NORM) and contaminated uranium in the soil. To verify the validity of the method, the verification of the uranium radioactivity concentration estimation method through γ-ray analysis results corrected by self-absorption using MCNP6.2, and the validity of the pre-classification method according to the net peak area ratio were evaluated. Estimating concentration for 238U and 235U with γ-ray analysis using HPGe (GC3018) and MCNP6.2 was verified by 􀟙-spectrometry. The analysis results of different methods were within the deviation range. Clearance screening factors (CSFs) were derived through MCNP6.2, and net peak area ratio were calculated at 295.21 keV, 351.92 keV(214Pb), 609.31 keV, 1120.28 keV, 1764.49 keV(214Bi) of to the 92.59 keV. CSFs for contaminated soil and natural soil were compared with U/Pb ratio. CSFs and radioactivity concentrations were measured, and the deviation from the 60 minute measurement results was compared in natural soil. Pre-classification is possible using by CSFs measured for more than 5 minutes to the average concentration of 214Pb or 214Bi in contaminated soil. In this study, the pre-classification method of clearance determination in contaminated soil was evaluated, and it was relatively accurate in a shorter measurement time than the method using the concentrations. This method is expected to be used as a simple pre-classification method through additional research.
        3.
        2023.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        High-entropy alloys (HEAs) are attracting attention because of their excellent properties and functions; however, they are relatively expensive compared with commercial alloys. Therefore, various efforts have been made to reduce the cost of raw materials. In this study, MIM is attempted using coarse equiatomic CoCrFeMnNi HEA powders. The mixing ratio (powder:binder) for HEA feedstock preparation is explored using torque rheometer. The block-shaped green parts are fabricated through a metal injection molding process using feedstock. The thermal debinding conditions are explored by thermogravimetric analysis, and solvent and thermal debinding are performed. It is densified under various sintering conditions considering the melting point of the HEA. The final product, which contains a small amount of non-FCC phase, is manufactured at a sintering temperature of 1250oC.
        4,000원
        5.
        2019.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        고온기 화색발현이 우수하고 연중생산이 가능한 수출용 스프레이국화 신품종을 육성하기 위하여 충남농업기술원 화훼 연구소에서 2010년 분홍색의 모본 ‘Borami’를 방임수분하였다. 2011년에 종자를 파종하였고, 이중 화형과 화색이 우수한 개체를 선발하여 ‘SP11-148-01’로 계통명을 부여하였다. 2011년부터 2013년까지 주년 생산성을 위해 전조, 자연, 차광재배로 특성을 각각 검정하였고, 생육 및 개화특성은 화형과 화색이 비슷한 자주색 스프레이국화인 ‘Kingfisher’를 대조품종으로 조사하였으며, 2013년 ‘Yes Ruby’로 품종등록 출원하였다. ‘Yes Ruby’는 자주색의 설상화와 연녹색의 통상화로 가을 작형 개화기는 10월 24일로, ‘Kingfisher’의 10월 29일에 비해 빨랐다. ‘Yes Ruby’의 초장과 줄기굵기는 각각 94.9cm와 7.7mm로 ‘Kingfisher’의 89.2cm와 6.4mm보다 컸다. ‘Yes Ruby’의 꽃 직경은 6.2cm로 ‘Kingfisher’의 5.0cm보다 컸으며, 꽃잎수도 ‘Yes Ruby’가 25.7개로 ‘Kingfisher’의 23.3개보다 많았다. 착화수는 두 품종 모두 비슷하였으며, 흰녹병 저항성은 ‘Yes Ruby’가 2단계, ‘Kingfisher’는 3단계의 감염 정도를 나타내어 흰녹병에 대한 저항성이 높은 것으로 나타났다. 재배상 유의사항은 ‘Yes Ruby’는 겨울철 균일한 개화가 이뤄지지 않아 겨울철 야간온도를 18℃ 이상으로 관리해줌으로써 균일개화를 유도할 수 있다. 또한 생장억제제인 Daminozide을 처리함으로써 설상화수를 늘려 볼륨감 높은 꽃봉오리를 형성할 수 있어 고온기에도 화색발현이 우수하고 연중생산이 가능하여 안정적 수출을 통한 농가소득 증대에 기여할 수 있을 것으로 기대된다.
        4,000원
        6.
        2018.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        스탠다드국화 신품종을 육성하기 위하여 충남농업기술원 화훼연구소에서 2009년에 황색의 모본 ‘Summer Yellow’와 부본 ‘ST07-09-02’계통을 인공 교배하였다. 2010년에 종자를 파종하였고, 이중 내병성이 강하고 기호성이 우수한 개체를 선발하여 ‘ST10-047-01’로 계통명을 부여하였다. 2011년부터 2013년까지 주년 생산성을 위해 촉성 및 자연, 억제재배 특성을 각각 검정하였으며, 2013년 ‘Geumhwa’로 명명하고 품종등록 출원하였다. ‘Geumhwa’의 생육 및 개화특성은 국내에서 많이 재배되고 있는 황색 스탠다드국화인 ‘Summer Yellow’를 대조 품종으로 하여 조사하였다. ‘Geumhwa’ 품종은 자연개화기가 10월 6일로 ‘Summer Yellow’의 10월 25일에 비해 빨랐다. ‘Geumhwa’는 초장이 86.3cm로 ‘Summer Yellow’의 93.8cm보다 작았고, 곁가지 제거수는 8.1개로 ‘Summer Yellow’의 16.6개보다 적었다. ‘Geumhwa’의 꽃직경은 13.6cm로 ‘Summer Yellow’의 13.5cm와 비슷하였으며, 꽃잎수는 ‘Geumhwa’가 263.6개로 ‘Summer Yellow’의 295.3개보다 적었다. 재배상 유의사항은 ‘Geumhwa’는 중간종이므로 초기생육이 왕성하도록 비배 관리를 하고 생육기간 중 지베렐린 1,000mg・L-1를 2회 처리하여 신장력을 높이도록 한다. 또한 설상화수가 적은 편이므로 재전조를 실시하여 설상화수를 늘린다면 황색의 연중 조기개화가 가능한 고품질 신품종 스탠다드 절화국화로써 소비자 기호 충족 및 농가소득 창출에 기여할 수 있을 것으로 기대된다.
        4,000원
        7.
        2016.10 구독 인증기관·개인회원 무료
        Zika virus, mosquito-borne disease, caused by mosquitoes has been increased the importance. From March to September, twice a month from 7 different points (3 residential areas, 3 migratory bird sanctuary and 1 cattle shed) were collected using BG trap and BL trap. After identifying the mosquitoes collected, we confirmed the virus infection. Total 26,531 mosquitoes (6 genus 9 species) were collected, virus has been detected from the 3 species (Aedes vexans, Cuilex tritaeniorhynchus, and Amigeres subalbatus) of mosquitoes of them. It showed the highest peak in August, and then gradually decreased. The most common mosquito species was collected Aedes vexan (16,637) in the cattle shed.
        8.
        2016.10 구독 인증기관·개인회원 무료
        Monochamus saltuarius is one of the insect vector of pine wilt disease with Monochamus alternatus. The present study aimed to investigate the dose to induce sterile and the effect of sterility according to the gender of M. saltuarius. As the electron beam irradiation dose increased, the hatchability, adult eclosion rate and longevity of the former mid and late maturation feeding stage of adults was slightly reduced. However, there was no difference between these two adults. In addition, female adults were more sensitive to the electron beam than the male adults. Hatchability of the F1 generation of ♂T × ♀N o r♀T × ♂N (T: 200 Gy electron beam irradiation, N: 0 Gy) was completely suppressed. As electron beam irradiation dose increased, the fecundity of female adults were slightly decreased. Results by comet assay showed that electron beam irradiation induced as dose increased DNA damage in M. saltuarius adults. These results suggest that SIT using electron beam may be useful for control of M. saltuarius.
        10.
        2016.04 구독 인증기관·개인회원 무료
        Mealybugs (Hemiptera: Pseudococcidae) are major pests of a wide range of crops and ornamental plants worldwide, and represented by 56 species in Korea. Occurrence of, or damage by, the longtailed mealybug, Pseudococcus longispinus Targioni-Tozzetti has not been reported since 2002. However, for the first time in many years, P. longispinus was reported at Phalaenopsis orchids by Kim et al in 2015. Therefore, the present study aimed to investigate the distribution of P. longispinus which is usually found inside a greenhouse or a building where the host plants are. We have collected 129 mealybug samples at 254 sites from Korea. Among these, 27 of P. longispinus and 62 of an unidentified Pseudococcus species were found mainly in ornamental plants such as Heteropanax fragrans, commonly known as happy trees in Korea. Morphological characteristics of the unidentified mealybug were very similar to those of P. longispinus. However, the genetic variability in COI sequence comparison was significantly different between the two species. Further studies are needed to clarify the valid name for this unidentified species, and we are currently working on it.
        11.
        2014.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Mushrooms are considered not only as food but also for source of physiologically beneficial medicines. The culinarymedicinal mushrooms may important role in the prevention of age-associated neurological dysfunctions, including Alzheimer’s and Parkinson’s diseases. Hericium erinaceus (H. erinaceus), is edible mushrooms, is a parasitic fungus that grows hanging off of logs and trees and well established candidate for brain and nerve health. H. erinaceus contains high amounts of antioxidants, beta-glucan, polysaccharides and a potent catalyst for brain tissue regeneration and helps to improve memory and cognitive functions. Its fruiting bodies and the fungal mycelia exhibit various pharmacological activities, including the enhancement of the immune system, antitumor, hypoglycemic and anti-aging properties. H. erinaceus stimulates the synthesis of Nerve Growth Factor (NGF) which is the primary protein nutrient responsible for enhancing and repairing neurological disorders. Especially hericenones and erinacines isolated from its fruitin body stimulate NGF, synthesis. This fungus is also utilized to regulate blood levels of glucose, triglycerides and cholesterol. H. erinaceus can be considered as useful therapeutic agents in the management and/or treatment of neurodegeneration diseases. However, this review focuses on in vitro, in vivo and clinical trials for neurodegerative disease.
        4,000원
        14.
        2018.12 KCI 등재 서비스 종료(열람 제한)
        본 연구에서는 보령댐 유역(163.6 km2)을 대상으로 SWAT (Soil and Water Assessment Tool) 모델, GCM (General Circulation Model) 기 후변화 시나리오와 다중회귀분석으로 산정한 미래 방류량을 활용하여 극한 기후변화 사상이 반영된 보령댐의 물부족을 평가하였다. 유역의 물수지 분석을 위해 보령댐 유역을 대상으로 기상자료, 보령댐 운영자료를 수집하였으며, SWAT 모형의 신뢰성 있는 유출량 보정을 위해 보령댐의 실 측 방류량을 이용하여 댐 운영모의를 고려하였고 유입량 및 방류량 자료를 활용하여 모형의 보정(2007~2010)과 검증(2010~2016)을 실시하였다. 기후변화를 반영하기 위해 APCC의 26개 CMIP5 GCM 자료 중 RCP (Representative Concentration Pathway)4.5와 RCP 8.5 시나리오를 SPI와 극한 가뭄지수로 분석하여 RCP 8.5 BCC-CSM1-1-M을 극한 가뭄 시나리오로 선정하였다. 2005년부터 2016년까지의 일별 관측자료로 다중회귀분석하여 월별 방류량 추정식을 만들었고, 1월부터 12월까지 각 식들의 결정계수 R2는 0.57 이상으로 나타났다. 선정된 극한 가뭄 시나리오 기상자료를 방류량 추정식에 대입하여 미래기간 일별 방류량을 구축하였다. SWAT 수문평가 결과, S3 (2037~2046) 기간 봄철 저수량이 34.0% 감소하는 것으로 분석되었다. Runs 이론을 바탕으로 물부족의 심도를 구한 다음 재현기간에 따른 빈도해석을 하였다. 5~10년 빈도의 심 도로 발생하는 물부족이 미래기간에 발생하는 빈도로 보령댐의 물부족을 평가하였다. 물부족 평가 결과, S3 (2037~2046) 기간에서 5~10년 빈도의 심도를 가지는 물부족이 기준기간(2007~2016) 보다 2회 더 발생하였으며 S3 (2037~2046)에 물부족 계획 수립이 필요하다고 판단하였다.
        15.
        2018.10 KCI 등재 서비스 종료(열람 제한)
        본 연구의 목적은 기상자료(강수량, 최고기온, 최저기온, 평균기온, 평균풍속) 기반의 다중선형 회귀모형을 개발하여 농업용저수지 저수율을 예측 하는 것이다. 나이브 베이즈 분류를 활용하여 전국 1,559개의 저수지를 지리형태학적 제원(유효저수량, 수혜면적, 유역면적, 위도, 경도 및 한발빈도)을 기준으로 30개 군집으로 분류하였다. 각 군집별로, 기상청 기상자료와 한국농어촌공사 저수지 저수율의 13년(2002~2014) 자료를 활용하여 월별 회귀모형을 유도하였다. 저수율의 회귀모형은 결정계수(R2)가 0.76, Nash-Sutcliffe efficiency (NSE)가 0.73, 평균제곱근오차가 8.33%로 나타났다. 회귀모형은 2년(2015~2016) 기간의 기상청 3개월 기상전망자료인 GloSea5 (GS5)를 사용하여 평가되었다. 현재저수율과 평년저수율에 의해 산정되는 저수지 가뭄지수(Reservoir Drought Index, RDI)에 의한 ROC (Receiver Operating Characteristics) 분석의 적중률은 관측값을 이용한 회귀식에서 0.80과 GS5를 이용한 회귀식에서 0.73으로 나타났다. 본 연구의 결과를 이용해 미래 저수율을 전망하여 안정적인 미래 농업용수 공급에 대한 의사결정 자료로 사용할 수 있을 것이다.
        16.
        2018.10 서비스 종료(열람 제한)
        Background : Osteoclasts are differentiated from the monocytes/macrophages of hematopoietic cells, that excessive activities of bone-resorbing giant cells leads to pathological bone diseases such as osteoporosis (contained rheumatoid arthritis and autoimmune arthritis). Therefore, it is very important to suppress loss of bone mass by deactivation of osteoclast differentiation. In this context, we evaluated for the effects of black ginseng (BG) extract on TRAP activity, proliferation and differentiation in RANKL-induced osteoclastic RAW264.7 cells. Methods and Results : The aim of this study is to figure out the potential anti-osteoporosis effects and the underlying mechanism of BG extract in RANKL-induced osteoclastic RAW264.7 cells. The ginsenoside Rg3, Rg5, Rk1 and Rh4 content of BG was increased more than Red ginseng (RG). The extracts of BG markedly reduced the activity of tartrate-resistant acid phosphatase-positive (TRAP+) multinucleated cells from osteoclastic RAW264.7 cells, without cytotoxicity. BG clearly inhibited RANKL-induced osteoclast differentiation by decreased calcitonin and TRAP (p < 0.01). Furthermore, ginseonside Rg5 and Rk1 significantly inhibited TRAP activity in formation of osteoclastic differentiation (p < 0.01). It is also found that Ginseonside Rg5 and Rk1 mixture more inhibits osteoclast differentiation activity. Conclusion : Our results suggest that Black ginseng extract has an anti-osteoporosis effects in bone disease when administered as a food supplement and has potential as a therapeutic agent for osteoporosis.
        17.
        2018.10 서비스 종료(열람 제한)
        Background : The human patch test is a method used to evaluate potential skin irritation after contact with a cosmetic materials. Pectin lyase-modified red ginseng extract (GS-E3D) is a newly developed ginsenoside Rd-enriched ginseng extract. This study was designed to investigate the skin safety of GS-E3D in human patch test. Methods and Results : Thirty two female volunteers were tested with GS-E3D. GS-E3D (20 ㎕) was applied to occlusive patch test devices and was then applied onto the back of subject with normal skin for 24 hours. Cutaneous irritation responses were evaluated and graded according to criterion of International Contact Dermatitis Research Group (ICDRG) at 30 min, 24 hours, and 48 hours after removing of GS-E3D patch. The average age of subjects was 47.3 ± 9.3 years. Skin reactivity calculated from irritation score in GS-E3D treated group was 0.51 and skin irritation score of no application group was 0, respectively. Skin irritancy was no response in both GS-E3D treated group and no application group. From above data, GS-E3D was identified as a non-irritant according to ICDRG guideline that skin irritation score of ‘0.00 - 0.75’ is a non-irritant. Conclusion : These results indicate that GS-E3D can be useful as a safe cometic ingredient.
        18.
        2018.10 서비스 종료(열람 제한)
        Background : Pectin lyase-modified red ginseng extract (GS-E3D) is a newly developed ginsenoside Rd-enriched ginseng extract. This study was designed to investigate the acute oral and dermal toxicity of GS-E3D in rat. Methods and Results : The acute oral toxic effects of GS-E3D in female SD rats were examined at dosages of 300 ㎎/㎏ and 2,000 ㎎/㎏. In acute dermal toxicity study, 500, 1,000 and 2,000 ㎎/㎏ of GS-E3D were applied onto the shaved skin of male and female SD rats. The weights of rats were recorded at 0, 1, 3, 7, and 14 days and clinical observation were checked once a day for a period of 14 days. All rats were scarified on 14th day and complete gross examination was conducted to detect any gross change of organs after necropsy. GS-E3D did not produce orally or dermally treatment-related clinical signs of toxicity or mortality in all rats during the 14-day observation period. The oral and dermal LD50 values of GS-E3D were over 2,000 ㎎/㎏ in rat. The oral and dermal administration of GS-E3D revealed no significant change in body weight and gross pathology examination compared to control group. Conclusion : These results indicate that GS-E3D can be used as a food and cosmetic materials without critically adverse effect.
        19.
        2018.05 서비스 종료(열람 제한)
        Background : Non-alcoholic fatty liver disease (NAFLD) is caused by obesity, type 2 diabetes mellitus, dyslipidemia, and genetic factors. Also, hyperinsulinemia directly promotes fat accumulation in hepatocytes. Therefore, it is very important to suppress the most common risks of NAFLD, such as obesity and insulin resistance. In this context, we evaluated for the effects of black ginseng (BG) extract on lipid accumulation inhibition and degradation in hepatocytes. Methods and Results : The aim of this study is to figure out the potential anti-lipogenic effects and the underlying mechanism of BG extract in a cellular-, type 2 diabetes mellitus (T2DM) animal model associated with NAFLD. T2DM animal used C57BL/KsJ db/db mouse (M. 6 wk, n = 56), treated with extract of BG and Red ginseng (RG) (each 100 and 900 ㎎/ ㎏/day, p.o) for 6 weeks. BG markedly reduced palmitate-induced intracellular lipid accumulation in HepG2 cells. On histology of liver tissues of T2DM animal, macrovesicular lipid droplets in cytoplasm of hepatocytes were decreased both RG and BG-treated groups. In liver tissue, BG-treated groups suppressed CCAAT/enhancer binding protein-α (C/EBP-α), sterol regulatory element-binding protein-1c (SREBP-1c) expression, and SREBP-1c mediated induction of acetyl-CoA carboxylase (ACC) and fatty acid synthase (FAS) proteins related to the induction of adipose differentiation. Futhermore, adenosine monophosphate (AMP)-activated protein kinase (AMPK) activity was significantly increased in BG-treated groups compared to RG-treated groups. It is also found that peroxisome proliferator-activated receptor-α (PPAR-α) highly expressed in BG-treated groups. Conclusion : Our results suggest that black ginseng extract has an anti-adipogenic and anti-lipogenic effects in the liver when administered as a food supplement and has potential as a therapeutic agent for obesity and T2DM induced NAFLD.
        20.
        2017.04 KCI 등재 서비스 종료(열람 제한)
        Bisphenol A (BPA), a known endocrine disruptor, induces toxicity in cells and in experimental animals. Ginseng extracts were evaluated to determine whether they can inhibit BPA-induced toxicity. The antioxidant activity of fresh ginseng extract (WGE), dried white ginseng extract (DGE), and dried red ginseng extract (RGE) was measured using the DPPH assay. WGE and RGE increased DPPH free radical scavenging activity. Cell viability was measured in HepG2 cells following treatment with BPA and ginseng extracts using the MTT assay. DGE and RGE increased HepG2 cell viability following treatment with 200 μM BPA. RGE reduced levels of biochemical markers of liver damage, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) that increased in mice following treatment with BPA. In addition, the regeneration and proliferation of damaged liver cells were significantly increased in RGE-treated mice. Moreover, RGE inhibited hepatic fibrosis in the surrounding area and in the central vein of the liver microstructure. RGE also significantly inhibited BPA-induced cytotoxicity. In addition, RGE protected liver damage and regenerated liver tissues in BPA-treated animals. These results show that RGE may represent a potential candidate drug for the treatment and prevention of liver damage caused by environmental toxins.
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