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        검색결과 1,529

        102.
        2023.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Coupled thermo-hydraulic-mechanical (THM) processes are essential for the long-term performance of deep geological disposal of high-level radioactive waste. In this study, a numerical sensitivity analysis was performed to analyze the effect of rock properties on THM responses after the execution of the heater test at the Kamaishi mine in Japan. The TOUGHFLAC simulator was applied for the numerical simulation assuming a continuum model for coupled THM analysis. The rock properties included in the sensitivity study were the Young’s modulus, permeability, thermal conductivity, and thermal expansion coefficients of crystalline rock, rock salt, and clay. The responses, i.e., temperature, water content, displacement, and stress, were measured at monitoring points in the buffer and near-field rock mass during the simulations. The thermal conductivity had an overarching impact on THM responses. The influence of Young’s modulus was evident in the mechanical behavior, whereas that of permeability was noticed through the change in the temperature and water content. The difference in the THM responses of the three rock type models implies the importance of the appropriate characterization of rock mass properties with regard to the performance assessment of the deep geological disposal of high-level radioactive waste.
        5,400원
        103.
        2023.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Intermuscular fat is essential for enhancing the flavor and texture of cultured meat. Mesenchymal stem cells derived from intermuscular adipose tissues are a source of intermuscular fat. Therefore, as a step towards developing a platform to derive intermuscular fat from mesenchymal stem cells (MSCs) for insertion between myofibrils in cultured beef, an advanced protocol of intermuscular adipose tissue dissociation effective to the isolation of MSCs from intermuscular adipose tissues was developed in cattle. To accomplish this, physical steps were added to the enzymatic dissociation of intermuscular adipose tissues, and the MSCs were established from primary cells dissociated with physical step-free and step-added enzymatic dissociation protocols. The application of a physical step (intensive shaking up) at 5 minutes intervals during enzymatic dissociation resulted in the greatest number of primary cells derived from intermuscular adipose tissues, showed effective formation of colony forming units-fibroblasts (CFU-Fs) from the retrieved primary cells, and generated MSCs with no increase in doubling time. Thus, this protocol will contribute to the stable supply of good quality adipose-derived mesenchymal stem cells (ADMSCs) as a fat source for the production of marbled cultured beef.
        4,000원
        104.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A facile and efficient method was developed to prepare highly stretchable and conductive graphene conductors with wrinkled structures by the mechanical stretching and shrinking of elastomeric substrates, in which graphene inks were printed on a prestretched elastomeric substrate. Stretchable and exfoliated graphene inks were prepared by mixing graphite and Ecoflex in a shear-assisted fluid dynamics reactor. The resultant graphene conductor exhibited excellent stretchability at 150% strain and high electrical conductivity of 64 ± 1.2 S m− 1. The resistance of the conductor did not change in bent, twisted, and stretched states. The resistance did not change during 10,000 cycles of stretching/releasing, with a maximum strain of 150%. Based on the graphene conductor, a stretchable conductometric sensor with a two-electrode configuration was fabricated to measure impedance changes at different concentrations of electrolyte ions. This sensor exhibited a good and linear sensitivity curve (298.61 Ω mM− 1, R2 = 0.999) in bent and stretched states.
        4,000원
        105.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 관상가치가 있는 자생 참두메부추와 갯부추를 절화소재로 이용하고자 수행되었다. 실험은 절화가 수확된 직후, gibberellic acid(GA3) 50, 75, 100mg·L-1, silver thiosulfate(STS) 0.1, 0.3, 0.5mM, 8-hydroxyquinoline sulfate(8-HQS) 25, 50, 100mg·L-1, 그리고 시중에 판매되 고 있는 Chrysal 8mL·L-1, Floralife 10mL·L-1의 보존용액 에 처리되었다. 참두메부추의 절화수명 연장에는 Chrysal 보 존용액 처리가 가장 효과적이었으며 다음으로 75mg·L-1 GA3 처리가 효과적이었다. 한편 8-HQS와 STS는 참두메부추의 절화수명을 단축하고 줄기가 갈변하는 등의 부정적인 영향을 끼쳤다. Chrysal과 더불어 Floralife 보존용액 처리는 절화 참두메부추의 상대 생체중변화율을 높이는데 효과가 있었다. 반면 갯부추는 100mg·L-1 GA3 처리에서 절화수명이 유일하 게 7일까지 연장되었다. GA3 보존용액 처리를 제외한 다른 처리에서 갯부추의 절화수명은 증류수인 대조구보다 비슷하 거나 약간 높은 수준이었다. 절화 갯부추의 수분흡수율은 실 험 초반 100mg·L-1 8-HQS 처리에서, 상대 생체중변화율은 Chrysal 보존용액 처리에서 가장 높게 조사되었으나 두 처 리 모두 절화수명이 유의하게 연장되지 않았다. 갯부추는 100mg·L-1 GA3 처리에서 절화수명을 비롯한 절화품질이 가 장 우수하였다.
        4,200원
        106.
        2022.12 구독 인증기관 무료, 개인회원 유료
        L-asparaginase (ASNase) is a therapeutic enzyme used to treat acute lymphoblastic leukemia. Currently, the most widely used ASNases are originated from bacteria. However, owing to the adverse effects of bacterial ASNases, new resources for ASNase production should be explored. Fungal enzymes are considered efficient and compatible resources of natural products for diverse applications. In particular, fungal species belonging to the genus Trichoderma are well-known producers of several commercial enzymes including cellulase, chitinase, and xylanase. However, enzyme production by marine-derived Trichoderma spp. remains to be elucidated. While screening for extracellular ASNase-producing fungi from marine environments, we found four strains showing extracellular ASNase activity. Based on the morphological and phylogenetic analyses using sequences of translation elongation factor 1-alpha (tef1α), the Trichoderma isolates were identified as T. afroharzianum, T. asperellem, T. citrinoviride, and Trichoderma sp. 1. All four strains showed different ASNase activities depending on the carbon sources. T. asperellem MABIK FU00000795 showed the highest ASNase value with lactose as a carbon source. Based on our findings, we propose that marine-derived Trichoderma spp. are potential candidates for novel ASNase production.
        4,000원
        107.
        2022.12 구독 인증기관 무료, 개인회원 유료
        Image recognition is not very effective in the water environment due to multiple factors, such as high scattering and high scattering in the water column. This is why the relevant parameters in the Faster R-CNN network model need to adjust continuously to improve the effectiveness of water detection. The control variable method adjusts the program's learning rate by tuning the network model's parameters. Then, the number of training rounds is adjusted according to the loss function of each round, and finally, we can get the number of matches with the minimum loss function. Based on the experimental results on the dataset, it is shown that the proposed method not only selects the learning rate with the best detection results but also has the strongest robustness and achieves a 96%-99% recognition rate for passenger ships, cargo ships, warships, and bridges compared with other learning rates. Experiments show that the Faster R-CNN network model detects water targets with significant results, and the best network model learning rate parameter is 6×10-3.
        4,000원
        108.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Repetitive or excessive exposure to ultraviolet (UV) radiation causes oxidative stress-mediated skin photoaging through the overproduction of reactive oxygen species. Actinidia polygama is known as a medical plant used in oriental medicine for treating several diseases such as abdominal pain, stroke and rheumatoid arthritis. Recently, it was reported that A. polygama extract had anti-wrinkle and skin hydrating properties in ultraviolet B (UVB)-exposed hairless mice. However, the molecular biological mechanism of this extract on alleviating skin photoaging is still unknown. Therefore, we investigated the anti-photoaging effects of PB203, which is the powder of A. polygama extract, in the in vivo and in vitro photoaging models. First, PB203 showed 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) and 2,2-diphenyl-1-picrylhydrazyl radical scavenging activities due to the presence of anti-oxidant components including flavonoids and polyphenols. In UVB-irradiated hairless mice, oral administration of PB203 (100 mg/ kg) significantly improved wrinkle formation, skin dehydration, elasticity and skin barrier function by decreasing the levels of matrix metalloproteinases (MMPs) and increasing those of collagen I, filaggrin, involucrin and loricrin. Especially, the reduced production of p-p38, p-c-Jun and p-c-Fos by PB203 reversed the elevated levels of MMPs mediated by UVB exposure, resulting in the upregulation of collagen I expression. Consistent with these animal data, PB203 remarkably enhanced the mRNA expression of collagen I, filaggrin, involucrin and loricrin, while suppressed that of MMPs in UVB-irradiated HaCaT cells. And PB203 increased the wound recovery rate of cells by promoting their proliferation and migration. Moreover, PB203 significantly recovered the activity of superoxide dismutase inhibited by UVB in both mice and cells. In conclusion, PB203, which protects skin from UVB-induced photodamage by exerting antioxidant properties, can be considered to have sufficient potential as a functional ingredient or therapeutic agent improving skin photoaging and related skin symptoms.
        5,500원
        109.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Many manufacturers applying third party logistics (3PLs) have some challenges to increase their logistics efficiency. This study introduces an effort to estimate the weight of the delivery trucks provided by 3PL providers, which allows the manufacturer to package and load products in trailers in advance to reduce delivery time. The accuracy of the weigh estimation is more important due to the total weight regulation. This study uses not only the data from the company but also many general prediction variables such as weather, oil prices and population of destinations. In addition, operational statistics variables are developed to indicate the availabilities of the trucks in a specific weight category for each 3PL provider. The prediction model using XGBoost regressor and permutation feature importance method provides highly acceptable performance with MAPE of 2.785% and shows the effectiveness of the developed operational statistics variables.
        4,000원
        110.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 논문에서는 외계 행성에서 주어진 임무를 모두 수행하여 클리어하는 탑 뷰 슈팅 게임을 제안한다. 제안 하는 게임을 진행한 플레이어 45명의 로그 기록과 설문 조사 결과를 분석하여, 몰입감, 플레이 패턴의 다양 성, 접근성을 중심으로 제안하는 게임의 특징을 살펴보고자 한다. 첫째, 제안한 게임은 더 높은 몰입감을 위 해 스토리 애니메이션과 오디오를 제공한다. 실험 결과 시각, 청각적 방면으로 몰입감을 효과적으로 제공하 고 있어 대다수의 플레이어가 스토리 애니메이션을 건너뛰지 않고 끝까지 시청했다. 둘째, 제안하는 게임은 더 다양한 플레이 패턴으로 즐길 수 있다. 실험 결과 수많은 경우의 수가 존재하는 무기와 스킬을 선택할 수 있게 하였기 때문에 대부분의 플레이어가 선택하는 스킬들이 서로 겹치지 않고 다양한 방식으로 게임을 플레이할 수 있다. 플레이 패턴이 다양한 만큼 더 게임을 오랫동안, 더 재미있게 즐길 수 있다. 셋째, 제안한 게임은 맵을 비교적 단순하게 구성하였다. 그런데, 호기심 많은 일부 플레이어들이 미션과 직접 관련이 없는 경로를 찾아서 길을 헤매는 경우가 나타났다. 이로 인해, 플레이어들이 게임을 다시 한번 진행하고자 하는 경향이 나타났다.
        4,000원
        111.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        디지털로 시작된 세대 간의 지식전복과 이에 따른 격차는 게임이라는 콘텐츠를 통해 그 차이점을 드러낼 것이라는 것을 가정하고 본 연구를 수행하였다. 이를 증명하기 위해 실제 부모의 게임에 관한 인식이 자녀 의 삶에 중요한 변수로 자리를 잡고 있는지 분석해 보는 것이 본 연구를 통해 알아보고자 하는 것이 주요 내용이었다. 분석 결과, 부모의 게임인식은 자녀의 삶에 직접적으로 영향을 미치진 않았다. 하지만 자녀가 판단했을 때 부모의 게임인식 수준은 자녀의 삶의 만족도에 상당한 영향을 미치고 있는 것으로 확인이 되 었다. 이는 부모가 스스로 판단하는 게임인식보다, 디지털 세대인 자녀의 게임 활동과 문화를 어떻게 인식 하고 대하는지에 따라 자녀의 행복에 영향을 미친다는 것이다. 본 연구의 결과는 자녀가 인식하는 부모의 게임인식과 자녀의 게임인식 간의 격차는 청소년 자녀의 행복에 매우 중요한 요인으로 작용을 하며, 이는 청소년 자녀의 게임 활동을 부모세대가 꼭 배우고 습득하는 것만이 자녀 세대를 이해하는 길이 아니라, 자 녀와 함께 소통하면서 현재의 상황을 이해하는 것이 보다 중요한 요인으로 나타났다고 할 수 있다. 시대적 상황에 의하여 한 가정 내에 부득이하게 발생한 문화적 취향의 차이지만, 이를 부모가 인정하고 이해하는 방향으로 소통을 진행한다면 자녀의 삶에 매우 긍정적인 영향을 줄 수 있다는 것을 의미하기도 한다.
        4,000원
        118.
        2022.10 구독 인증기관·개인회원 무료
        According to the Nuclear Safety and Security Commission (NSSC) Notice No. 2021-26 “Delivery Regulations for the Low- and Intermediate Level Radioactive Waste (LILW)”, the activity of 3H, 14C, 55Fe, 58Co, 60Co, 59Ni, 63Ni, 90Sr, 94Nb, 99Tc, 129I, 137Cs, 144Ce, and gross alpha must be identified. Currently, the scaling factor of the dry active waste (DAW) for LILW is applied as an indirect evaluation method in Korea. The analyses are used the destructive methods and 55Fe, 60Co, 59Ni, 63Ni, 90Sr, 94Nb, 99Tc, and 137Cs, which are classified as nonvolatile nuclides, are separated through sequential separation and then measured by gamma detector, liquid scintillation counter (LSC), alpha/beta total counter (Gas Proportional Counter, GPC), and ICP-MS. We will introduce how to apply the existing nuclide separation method and improve the measurement method to supplement it.
        119.
        2022.10 구독 인증기관·개인회원 무료
        Currently, low and intermediate-level radioactive wastes and spent nuclear fuels are continuously generated in Korea. For the disposal of the radioactive wastes, the transport demand is expected to increase. Prior to transportation, it is necessary to evaluate the radiation risk of transportation to confirm that is not high. In Korea, there is no transportation risk assessment code that reflects domestic characteristics. Therefore, foreign assessment codes are used. In this study, before developing the overland transportation risk assessment code that reflects domestic characteristics, we analyzed the radiation risk assessment methodology in transportation accident codes developed in other countries. RADTRAN and RISKIND codes were selected as representative overland transportation risk assessment codes. For the two codes we analyzed accident scenarios, exposure pathways, and atmospheric diffusion. In RADTRAN, the user classifies accident severity for possible accident scenarios, and the user inputs the probability for each accident severity. On the other hand, in the case of RISKIND, the accident scenarios are classified and the probabilities are determined according to the NRC modal study (LLNL, 1987) in consideration of the cask impact velocity, cask impact angle, and fire temperature. In the case of RISKIND, the accident scenarios are applied only to transportation of spent nuclear fuel, and cannot be defined for low and intermediate-level radioactive waste. However, in the case of RADTRAN, since the severity and probability of accidents are defined by user, it can be applied to low and intermediate-level radioactive wastes. As the exposure pathways considered in transportation accident, both RADTRAN and RISKIND consider external exposure (cloudshine and groundshine), and internal exposure (inhalation, resuspension inhalation and ingestion). In the case of RADTRAN, additionally, external exposure due to loss of shielding (LOS) is considered. Atmospheric diffusion calculation is essential to determine the extent to which radioactive materials are diffused. In both RADTRAN and RISKIND, atmospheric diffusion calculations are based on Gaussian diffusion model. Users must input Pasquill stability class, release height, heat release, wind speed, temperature and mixing height, etc. Additionally, RADTRAN can input weather information relatively simply by inputting only the Pasquill stability class fraction and selecting the US average weather option. This study results will be used as a basis for developing radioactive waste overland transportation risk assessment code that reflects domestic characteristics.
        120.
        2022.10 구독 인증기관·개인회원 무료
        Cement is widely used as representative industrial material. In Korea, about 50 million tons of cement are consumed every year. In the manufacture of cement, raw materials containing NORM such as fly ash and bauxite are used. Therefore, the workers can be subjected to radiation exposure. The major exposure pathway in NORM industries is internal exposure due to inhalation of aerosol. Internal radiation dose due to aerosol inhalation varies depending on physicochemical properties of the aerosol. Therefore, the objective of this study was to investigate aerosol properties influencing inhalation dose in cement industries. In this study, aerosol properties were measured for two cement manufacturers. A particulate size distribution and concentration at various processing areas in cement manufacturing industries in Korea were analyzed using a cascade impactor. The mass density of raw materials and byproducts were measured using pycnometer. Shape of particulates was analyzed using SEM. The radioactivity concentration of Ra-226, Ra-228 for U/Th decay series was measured using HPGe. Particulate concentration by size was distributed log-normally with maximum at particle size about 7.2 μm in manufacturer A and 5.2 μm in manufacturer B. The mass density of fly ash and cement were 2.3±0.06, 3.2±0.02 g/cm3 respectively in manufacturer A. In manufacturer B, the mass density of bauxite and cement were 3.4±0.02, 2.9±0.01 g/cm3 respectively. The shape of particulates appeared as spherical shape in manufacturer A and B regardless of sampling area. Thus, a shape factor of unity could be assumed. The radioactivity concentrations of Ra-226, Ra-228 were 82±9, 82±8 Bq/kg for fly ash, and 25±4, 23±3 Bq/kg for cement in manufacturer A. In manufacturer B, the radioactivity concentrations of Ra-226, Ra-228 were 344±34, 391±32 Bq/kg for bauxite, and 122±13, 145±12 Bq/kg for cement. The radioactivity concentrations of Ra-226, Ra-228 in cement were less than raw materials such as fly ash and bauxite. It is because the dilution of the radioactivity concentration occurred during mixing with other raw materials in cement production process. This study results will be used as database for accurate dose assessment due to airborne particulate inhalation by workers in cement industries.