• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2009년도 추계학술발표대회 논문집
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• pp.62-67
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• 2009

This paper describes the characteristics of scroll type stirling engine receiver. Scroll type stirling engine operated scroll compressor and expander instead of piston. Pass dimension of the receiver was $14(W){\times}14(H)$ mm and total pass length was 5,049 mm. External dimension of the receiver was $300{\times}300mm$. The experimental facility consisted of parabolic dish concentrator, compressor to supply air, triplex air filter, and flowmeter. In this study, basic experimental conditions were set at a inlet pressure of 5 bar and volume flow rate of $25m^3/hr$. As a result, air temperature in receiver at each measuring position of point 1, 2, 3 were $241^{\circ}C$, $465^{\circ}C$, and $542^{\circ}C$ respectively at inlet pressure of 5.5 bar and volume flow rate of $24.6m^3/hr$. As DNI increasing, heat transfer coefficient of the receiver changed from $695W/m^2K$ to $827W/m^2K$. Average heat transfer coefficient of receiver in the experiment was $798W/m^2K$. In addition, receiver efficiency became about 83%.

• Nuclear Engineering and Technology
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• 제52권1호
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• pp.1-13
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• 2020

At present, the Department of Energy (DOE) in Unite State are directing the efforts of developing accident tolerant fuel (ATF) technology. As the first barrier of nuclear fuel system, the material selection of fuel rod cladding for ATFs is a basic but very significant issue for the development of this concept. The advanced cladding is attractive for providing much stronger oxidation resistance and better in-pile behavior under sever accident conditions (such as SBO, LOCA) for giving more coping time and, of course, at least an equivalent performance under normal condition. In recent years, many researches on in-plie or out-pile physical properties of some suggested cladding materials have been conducted to solve this material selection problem. Base on published literatures, this paper introduced relevant research backgrounds, objectives, research institutions and their progresses on several main potential claddings include triplex SiC, FeCrAl and MAX phase material Ti3SiC2. The physical properties of these claddings for their application in ATF area are also reviewed in thermohydraulic and mechanical view for better understanding and simulating the behaviors of these new claddings. While most of important data are available from publications, there are still many relevant properties are lacking for the evaluations.

• 한국초지조사료학회지
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• 제42권3호
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• pp.201-207
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• 2022

Fescues, which are widely cultivated as grasses and forages around the world, are often naturally infected with the endophyte, Epichloë. This fungus, transmitted through seeds, imparts resistance to drying and herbivorous insects in its host without causing any external damage, thereby contributing to the adaptation of the host to the environment and maintaining a symbiosis. However, some endophytes, such as E. coenophialum synthesize ergovaline or lolitrem B, which accumulate in the plant and impart anti-mammalian properties. For example, when livestock consume excessive amounts of grass containing toxic endophytes, problems associated with neuromuscular abnormalities, such as convulsions, paralysis, high fever, decreased milk production, reproductive disorders, and even death, can occur. Therefore, pre-inoculation with non-toxic endogenous fungi or management with endophyte-free grass is important in preventing damage to livestock and producing high-quality forage. To date, the diagnosis of endophytes has been mainly performed by observation under a microscope following staining, or by performing an immune blot assay using a monoclonal antibody. Recently, the polymerase chain reaction (PCR)-based molecular diagnostic method is gaining importance in the fields of agriculture, livestock, and healthcare given the method's advantages. These include faster results, with greater accuracy and sensitivity than those obtained using conventional diagnostic methods. For the diagnosis of endophytes, the nested PCR method is the only available option developed; however, it is limited by the fact that the level of toxic alkaloid synthesis cannot be estimated. Therefore, in this study, we aimed to develop a triplex real-time PCR diagnostic method that can determine the presence or absence of endophyte infection using DNA extracted from seeds within 1 h, while simultaneously detecting easD and LtmC genes, which are related to toxic alkaloid synthesis. This new method was then also applied to real field samples.

• 한국산업융합학회 논문집
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• 제27권1호
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• pp.207-212
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• 2024

Recently, with the strengthening of environmental regulations, there has been an increasing interest in eco-friendly energy sources, leading to a trend of the increasing scale of Cargo Containment Systems (CCS) for Liquefied Natural Gas (LNG) carriers. Among these systems, membrane tanks have gained popularity in LNG transport vessels due to their superior spatial utilization and competitiveness. However, due to high initial investment costs and the difficulty in repair in case of damage, a safety layer, the secondary barrier, must be installed without fail. In this study, in order to apply a new secondary barrier to the existing membrane-type LNG CCS, tests were conducted on the fiberglass layer previously used in the Triplex-Flexible Secondary Barrier (FSB), substituting it with basalt fiber. Tensile and vertical tensile tests were performed to assess the newly applied material. Environmental tests were conducted at room temperature (25℃) and extremely low temperatures (-170℃), considering the temperatures to which substances may be exposed during LNG vessel operations. The basalt-FSB produced in this study demonstrated superior results compared to the specifications of the existing product, confirming its potential applicability for implementation.

• 식물병연구
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• 제23권3호
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• pp.234-240
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• 2017

경북 영양지역 노지고추 재배지에서 2012년부터 2016년까지 바이러스 증상를 보이는 시료를 채집하여 RT-PCR로 바이러스 감염양상을 조사하였다. 수집된 시료에 감염된 바이러스는 CMV 46.1%, BBWV2 41.5%, PepMoV 2.0%, PVY 2.0%, PMMoV 4.4%, TSWV 0.1%로 CMV와 BBWV2가 영양지역 노지고추에서 우점하는 바이러스로 나타났다. 바이러스 감염형태는 복합감염이 62.6%로 단독감염 31.2% 보다 많았다. 단독감염은 CMV가 19.1%로 가장 많았으며, BBWV2도 11.4%의 발생률을 보였다. 복합감염은 CMV+BBWV2 발생률이 49.3%로 가장 많았으며, 3종 및 4종 복합감염에서도 대부분 CMV+BBWV2를 포함하는 감염형태를 나타내었다. CMV 단독감염에서는 모자이크, 퇴록, 괴저, 황화 병징을 보였으며 BBWV2 단독감염은 퇴록, 모자이크 병징을 나타내었다. CMV와 BBWV2 복합감염은 퇴록과 심한 모자이크, 기형 병징을 일으켰다.

• 식물병연구
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• 제19권4호
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• pp.319-325
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• 2013

Soybean yellow mottle mosaic virus(SYMMV)와 Soybean yellow common mosaic virus(SYCMV) 병 발생은 최근에 우리나라에 보고되었지만 두 바이러스 병의 전국적인 분포에 대한 조사가 이루어지지 않아 본 연구팀은 2012년에 영세 농가를 중심으로 전국적인 조사를 실시하였다. 전국에 걸쳐 채집한 682점의 시료를 SYMMV, SYCMV, 그리고 Soybean mosaic virus(SMV) 특이 프라이머를 이용하여 진단한 결과, SMV 102점, SYMMV 116점, SYCMV는 17점이 PCR 양성으로 나타났다. SYMMV와 SYCMV의 복합감염은 검출되지 않았으나, SMV와 SYMMV 혹은 SMV와 SYCMV 복합감염은 각각 1건과 5건이 확인되었다. 처음으로 실시한 영세농가의 콩 바이러스 병 조사를 근거로 추정할 때, 바이러스의 발생은 자가 채종으로 인한 종자전염으로부터 발생되었을 것으로 추정된다. 따라서 바이러스 병의 예방을 위해서는 감염종자 관리 및 무병종자 보급이 무엇보다 필요함을 알 수 있다.

• 식물병연구
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• 제13권2호
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• pp.75-81
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• 2007

전국 52개 지역에서 2002년, 2004년에서 2006년, 4년 간 고추 바이러스 이병물을 채집하여 바이러스 감염양상을 조사하였다. 감염된 바이러스 종류는 Cucumber mosaic virus(CMV), Pepper mottle virus(PepMoV), Pepper mild mottle virus(PMMoV), Broad bean wilt virus 2(BBWV2), Tobacco mild green mosaic virus(TMGMV), Tomato spotted wilt virus(TSWV) 6종이었다. CMV, PepMoV PMMoV와 BBWV2의 발생률은 각각 29.4%, 13.6%, 14.3%, 25.6%이었다. TMGMV와 TSWV의 발생률은 1.0%로 매우 낮았다. 2002년과 2004년의 CMV 발생률은 53.3%와 34.2%로 가장 높았으나 2005년과 2006년에는 18.2%와 11.9%로 감소하였다. BBWV2의 발생률은 2002년에 1.3%, 2004년에 1.8%로 낮았으나, 2005년에 41.3%, 2006년에 58.2%로 크게 증가하였다. CMV+BBWV2의 발생률은 2002년에 0.0%, 2004년에 2.1%이었으나 2005년과 2006년에 각각 33.3%와 83.2% 증가하여 BBWV2의 단독감염과 함께 복합감염에서도 급격히 증가하였고 CMV+BBWV2+PepMoV의 삼중 복합감염률은 평균 6.4%이었다. CMV는 고추 잎에 심한 모자이크병징, BBWV2는 원형반점 병징을 일으키며, CMV와 BBWV2의 복합감염 경우에는 퇴록병징을 일으켰다. TSWV는 고추 잎과 과일에 전형적인 다중 원형반점을 일으켰다.

• 한국전산구조공학회논문집
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• 제27권6호
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• pp.625-633
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• 2014

본 논문에서는 액화천연가스 운송을 위해 사용되는 맴브레인형 Mark III 화물창 시스템의 주요 구조물인, 방열 판 구조물의 파손 강도 평가를 수행한 내용을 다루고 있다. Mark III 방열 판 구조물을 복합적층 구조물로 고려하였으며 상용화된 범용 유한요소 프로그램인 MSC사의 PATRAN과 MARC를 사용하여 Mark III 방열 판 구조물의 유한요소 모델을 개발하였다. 특히, 액화천연가스 화물의 특성으로 인해 Mark III 방열 판 구조물이 접하는 상온에서 극저온에 이르는 광범위한 온도 분포에 따른 재료 물성치 변화를 유한요소 모델에 포함하였다. 이 유한요소 모델을 기반으로 파손 강도 평가 절차가 확립되었으며, 이 때 Mark III 방열 판 구조물의 파손 발생 여부를 판단하기 위해 Hashin, Hill, Hoffman, maximum stress, 그리고 Tsai-Wu와 같은 이방성 파손 기준들을 사용하였다. Mark III 방열 판 구조물의 전반적인 구조적 거동을 이해하였으며 이후 초기 파손 영역에서 강도 평가를 수행하여 파손이 발생되었을 때의 위치와 하중 등을 알 수 있었다.

• 대한조선학회논문집
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• 제58권4호
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• pp.262-270
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• 2021

Consumption of Liquefied Natural Gas (LNG) has increased due to environmental pollution; therefore, the need for LNG carriers can efficiently transport large quantities of LNG, is increased. In various types of LNG Cargo Containment System (CCS), Membrane-type MARK-III composed of composite materials is generally employed in the construction of an LNG carrier. Among composite materials in a Mark-III system, glass-fiber composites act as a secondary barrier to prevent the inner hull structure from leakage of LNG when the primary barrier is damaged. Nevertheless, several cases of damage to the secondary barriers have been reported and if damage occurs, LNG can flow into the inner hull structure, causing a brittle fracture. To prevent those problems, this study conducted the applicability assessment of composite material manufactured by bonding glass-fiber and aluminum with epoxy resin and increasing layer from three-ply (triplex) to five-ply (pentaplex). Tensile tests were performed in five temperature points (25, -20, -70, -120, and -170℃) considering temperature gradient in CCS. Scanning Electron Microscopy (SEM) and Coefficient of Thermal Expansion (CTE) analyses were carried out to evaluate the microstructure and thermos-mechanical properties of the pentaplex. The results showed epoxy resin and increasing layer number contributed to improving the mechanical properties over the whole temperature range.

• Animal Bioscience
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• 제37권6호
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• pp.1021-1030
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• 2024

Objective: R-loops are DNA:RNA triplex hybrids, and their metabolism is tightly regulated by transcriptional regulation, DNA damage response, and chromatin structure dynamics. R-loop homeostasis is dynamically regulated and closely associated with gene transcription in mouse zygotes. However, the factors responsible for regulating these dynamic changes in the R-loops of fertilized mouse eggs have not yet been investigated. This study examined the functions of candidate factors that interact with R-loops during zygotic gene activation. Methods: In this study, we used publicly available next-generation sequencing datasets, including low-input ribosome profiling analysis and polymerase II chromatin immunoprecipitation-sequencing (ChIP-seq), to identify potential regulators of R-loop dynamics in zygotes. These datasets were downloaded, reanalyzed, and compared with mass spectrometry data to identify candidate factors involved in regulating R-loop dynamics. To validate the functions of these candidate factors, we treated mouse zygotes with chemical inhibitors using in vitro fertilization. Immunofluorescence with an anti-R-loop antibody was then performed to quantify changes in R-loop metabolism. Results: We identified DEAD-box-5 (DDX5) and histone deacetylase-2 (HDAC2) as candidates that potentially regulate R-loop metabolism in oocytes, zygotes and two-cell embryos based on change of their gene translation. Our analysis revealed that the DDX5 inhibition of activity led to decreased R-loop accumulation in pronuclei, indicating its involvement in regulating R-loop dynamics. However, the inhibition of histone deacetylase-2 activity did not significantly affect R-loop levels in pronuclei. Conclusion: These findings suggest that dynamic changes in R-loops during mouse zygote development are likely regulated by RNA helicases, particularly DDX5, in conjunction with transcriptional processes. Our study provides compelling evidence for the involvement of these factors in regulating R-loop dynamics during early embryonic development.