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        검색결과 13

        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.
        2023.11 구독 인증기관·개인회원 무료
        The demand for transportation is increasing due to the continuous generation of radioactive wastes. Especially, considering the geographical characteristics of Korea and the location characteristics of nuclear facilities, the demand for maritime transportation is expected to increase. If a sinking accident happens during maritime transportation, radioactive materials can be released into the ocean from radioactive waste transportation containers. Radioactive materials can spread through the ocean currents and have radiological effects on humans. The effect on humans is proportional to the concentration of radioactive materials in the ocean compartment. In order to calculate the concentration of radioactive materials that constantly flow along the ocean current, it is necessary to divide the wide ocean into appropriate compartments and express the transfer processes of radioactive materials between the compartments. Accordingly, this study analyzed various ocean transfer evaluation methodologies of overseas maritime transportation risk codes. MARINRAD, POSEIDON, and LAMER codes were selected to analyze the maritime transfer evaluation methodology. MARINRAD divided the ocean into two types of compartments that water and sediment compartments. And it was assumed that radionuclides are transfered from water to water or from water to sediment. Advection, diffusion, and sedimentation were established as transfer process for radionuclides between compartments. MARINRAD use transfer parameters to evaluate transer processes by advection, diffusion, and sedimentation. Transfer parameters were affected by flow rate, sedimentation rate, sediment porosity, and etc. POSEIDON also divided the ocean into two types that water and sediment compartment, each compartments was detaily divided into three vertical sub-compartment. Advection, diffusion, resuspension, sedimentation, and bioturbation were established as transport processes for radionuclides between compartments. POSEIDON also used transfer parameters for evaluating advection, diffusion, resuspension, sedimentation, and bioturbation. Transfer parameters were affected by suspended sediment rates, sedimentation rates, vertical diffusion coefficients, bioturbation factors, porosity, and etc. LAMER only considered the water compartment. It divided the water compartment into vertical detailed compartments. Diffusion, advection and sedimentation were established as the nuclide transfer processes between the compartments. To evaluated the transfer processes of nuclides for diffusion and advection, LAMER calculated the probability with generating random position vectors for radionuclides’ locations rather than deterministic methods such as MARINRAD’s transfer parameters or POSEIDON’s transfer rates to evaluate transfer processes. The results of this study can be used as a basis for developing radioactive materials’ ocean transfer evaluation model.
        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
        6.
        2019.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Citation frequency is an important factor in evaluating journal quality and is used as a measure of journal impact. The citation index of a paper plays an important role in linking papers with groups of other academic papers, forming a huge and complex network. This study examines the intellectual structure of apparel research through the bibliometric citation analysis of The Research Journal of the Costume Culture (RJCC). In order to analyze the changes in the intellectual structure of the RJCC, we used the Korea Citation Index’s (KCI) data (highly citing journals and highly cited journals). The NodeXL, a social network analysis tool, was used to examine the connection structure between journals. In order to identify the academic influence of the RJCC, we used the KCI journal citation index. Our findings indicate that the RJCC has a high centrality index among the clothing-oriented journals in the same life sciences field. A look at the journals citing the RJCC and the journals cited within the RJCC also showed that more journals of diverse fields have been recently linked through their citations. This suggests that a convergence of interdisciplinary research is underway in the field of clothing. As a result of examining international journals cited in the RJCC, it was confirmed that they were cited in prominent international journals in various fields.
        4,200원
        7.
        2018.10 구독 인증기관·개인회원 무료
        In order to accumulate the ecological information of Drosophila suzukii for export negotiations of domestic strawberry, we weekly monitored occurrence of D. suzukii at three strawberry fields located in Gok-seong, Dam-yang and Hwa-sun using the best combination of trap and attractant from November 2017 to May 2018, the period of strawberry production. Monitoring was carried out at three sites (a hill located 150 meter distant to greenhouse, outside greenhouse and inside greenhouse) in Gok-seong. Drosophil suzukii was trapped at three short periods from November to the beginning of December, from the end of December to the beginning of January, and from April in a hill. At outside greenhouse, D. suzukii was trapped at two short periods from November to the early December and the beginning of May. In inside greenhouse, it occurred once after May 24th. Gok-seong data can be summarized as more occurrence for longer period as the distance to greenhouse increases. Dam-yang occurred once in a short period inside greenhouse and hill, respectively on May. In case of Hwa-sun, D. suzukii did not trapped in whole trapping sites during trapping period, except for the surrounding grape and peach cultivation areas at the end of November. Summarized, no occurrence periods are from November 20th, 2017 to May 14th, 2018 inside greenhouse; from December 11th, 2017 to May 3rd, 2018 outside greenhouse; and from January 8th, 2018 to April 12th, 2018 on a hill. In connection with strawberry culture, the D. suzukii tends to occur at the beginning and the end of the strawberry production period. We expect this result can serve as a helpful data for export negotiation for quarantine.
        8.
        2018.04 구독 인증기관·개인회원 무료
        벗초파리는 우리나라에서는 심각한 해충으로 인식되지 않아 발생 기간 및 패턴, 기주 범위 등의 생태적인 연구뿐만 아니라 모니터링을 위한 우수 유인제 및 트랩의 연구도 제한적으로 수행된 실정이다. 본 연구는 기존 연구 결과를 참조하여 사과식초 함유 유인제 2종과 화학적 루어 2종 그리고 트랩 2종에 대한 선발 시험을 수행하였다. 선발 시험은 사육중인 벗초파리를 이용한 choice test와 함께 수목원, 딸기 농장, 블루베리 농장에서의 6반복 유인력 검증 실험을 수행하였다. 유인력 비교 결과 ACV + wine의 포획량이 높았으며, 블루베리 농장 인근 결과값은 전체 조사 항목에서 통계적 유의성을 보였다 (P < 0.05). 트랩 선발 실험 결과 모든 실험 장소에서 Dreves 트랩이 높은 포획량을 보였다. 이상의 결과를 통해 ACV + wine과 Dreves 트랩 조합을 선발하였으며, 이를 이용하여 향후 지속적인 모니터링, 월동 발생 조사 등의 연구에 활용할 수 있을 것으로 생각된다.
        9.
        2015.07 서비스 종료(열람 제한)
        Exposure to ionizing radiation is regarded as a kind of abiotic stresses that can change the expression of genes in living organisms. This study aimed on investigating the variations in gene expressions induced by two different types of irradiations with different doses, which were low linear energy transfer (LET) gamma rays (100, 200, and 400 Gy) and high LET ion-beams (20, 40, and 80 Gy) on rice. RNA sequencing was carried out using the Illumina HiSeq-2500 platform. The average amount of reads were 4.8 Gb per individual, and 5 to 8% of the reads were removed after quality control. More than 90% of the RNA-seq reads were mapped to the rice reference genome sequence (IRGSP-1.0). A total of 247 differentially expressed genes (DEGs) were identified by comparison of the gene expression levels between the wildtype and the irradiated individuals. The 247 DEGs were divided into five modules and 27 intra-modular hub genes were found using the weighted correlation network analysis (WGCNA) method. The MEturquiose module had the most number of genes with 75 related to carbohydrate and small molecule metabolic processes. The co-expression network reconstructed using ARACNE (algorithm for reconstruction of accurate cellular networks) showed specific up- or down-regulation of the genes in each module according to the types and doses of radiation. This study will contribute to understanding the gene expression responses to ionizing irradiation.
        10.
        2012.07 서비스 종료(열람 제한)
        Ionizing radiation is known to cause chromosomal alterations such as inversions and deletions and affects gene expression within the plant genome. To monitor the genome-wide transcriptome changes by ionizing radiation, we used rice Affimetrix GeneChip microarray to identify genes that are up- or down regulated by gamma-ray (200 Gy, 60Co source), cosmic-ray and ion beam (40 Gy, 220 MeV carbon ion). The overall expression patterns between gamma-ray and ion beam were similar but cosmic-ray was regulated differently. Combined results from all 3 radiations identified 27 up-regulated genes and 188 down regulated genes. These results mean the induction of similar mechanism changes in treatments of gamma ray and ion beam. However the different expression in treatment of cosmic-ray might be due to the other environmental conditions. Among the commonly up- or down- regulated genes, we chose highly up- or down- regulated several genes and confirmed its regulation in response to ionizing radiation exposure by RT-PCR analysis. Moreover, we showed that specific co-expression networks of candidate radio marker genes by ARACNE algorithm. Our results present profiles of gene expression related to different ionizing radiation and marker gene to predict sensitivity to ionizing radiation, such as GS (glutelin subunit) and FBX322.