In this study, the relationship between the color of the pigment added to the plastic resin and the size of the fractured part of the specimen was confirmed when processing ABS plastic tensile specimens using a sealed 3D printer. Through the test, it was confirmed that the fracture dimension existed in the range of 13.104 to 13.138 ㎜ and there was no significant difference in dimension according to the color of the additive, and the null hypothesis was adopted. In addition, it was confirmed that a significant difference occurred in the order of red, black, white, and green colors.

The hydride reorientation (HR) of used nuclear fuel cladding after operation affects the integrity during intermediate and disposal storage, as well as the handling processes associated with transportation and storage. In particular, during dry storage, which is an intermediate storage method, the radial hydrogen redistributes into circumferential hydrogen, increasing the embrittlement of used nuclear fuel cladding. This hydride reorientation is influenced by various key factors such as circumferential stress (hoop stress) due to internal rod pressure, maximum temperature reached, cooling rate during storage, and the concentration of precipitated hydrogen during irradiation. To simulate long-term dry storage of used nuclear fuel, hydrogenated Zircaloy-4 cladding (CWSRA) specimens were used in hydride reorientation tests under various hoop stress conditions (70, 80, 90, and 110 MPa) for extended cooling periods (3 months, 6 months, and 12 months). After the hydride reorientation tests, the cladding’s offset strain (%) was evaluated through a ring compression test, a mechanical property test encompassing both ductility and brittleness. In this study, the offset deformation of the hydride reorientation specimens was compared and evaluated through ring tensile tests. In this study, the offset deformation values were compared and evaluated through ring tensile tests of the hydride reorientation test specimens. Hydrogen in zirconium cladding reduces ductility from a physical perspective and induces rapid plastic deformation. Generally, even in hydrogenated unirradiated cladding, it maintains a tensile strength of around 800 MPa at room temperature. However, high hydrogen content accelerates plastic deformation. In contrast, samples with radial hydrogen distribution exhibit fracture behavior in the elastic region below 500 MPa. This is attributed to the directional of radial hydrogen distribution. Specimens with a hydrogen concentration of 200 ppm fracture faster than those with hydrogen concentrations exceeding 400 ppm. This is believed to be due to the ease of reorientation of radial hydrogen in cladding with relatively low hydrogen content. Although the consistency of the test results is not ideal, ongoing research is needed to identify trends in hydride reorientation from a cladding perspective.

In this study, the structural performance of the specimen fabricated through 3D printing was evaluated through monotonic loading experiments analysis to apply to 3D printed structures. The compression and flexural experiments were carried out, and the experimental results were compared to the finite element model results. The loading directions of specimens were investigated to consider the capacity of specimens with different curing periods, such as 7 and 28 days. As a result, the strength tended to increase slightly depending on the stacking direction. Also, between the 3D-printed panel composite and the non-reinforced panel, the bending performance depended on the presence or absence of composite reinforcement.

선박에 부착된 수중생물은 선체에서 성장하면서 선박의 저항을 크게 증가시킬 뿐만 아니라 부착생물이 배와 함께 이동하면서 지역의 해양 생태계 교란을 야기시키기도 한다. 이에 따라 국제해사기구에서는 선체부착생물의 이동을 막기 위해 선체부착생물 제거 및 청소성능 평가 논의를 시작해 오고 있다. 본 연구에서는 소형선박에 사용되는 FRP(Fiber Reinforced Plastic), HDPE((High Density Polyethylene), CFRP(Carbon Fiber Reinforced Plastic) 재료의 시편을 격포항(전락북도)에 약 80일간 양생시킨 후 물 제트 노즐을 이용하여 부착생물 제거실 험을 수행하였다. 그 결과 김과 같은 해조류는 노즐과 시편과의 거리가 1.8cm, 100bar 일 때 제거되었지만, 따개비의 경우 200 bar 이상은 되어야 청소가 되는 것을 확인하였다.

Recently, it is being carried out the project to evaluate the properties of materials harvested from nuclear reactor after the decommissioning of Kori Unit 1. However, it is not sufficient adequate machining equipment and remote machining technique to perform the projects for evaluation of materials harvested from nuclear reactor. Thus, it is required to develop the remote machining technique in hotcell to evaluate the mechanical properties of nuclear reactor materials. The machining technique should be performed inside a hotcell to evaluate mechanical properties of materials harvested from nuclear reactor and is essential to prevent radiation exposure of workers. Also, it is essential to design the apparatus and develop the machining process so that it can be operated with a manipulator and minimize contamination in hotcell. In this research, development of remote specimen machining technique in hotcell such as machining apparatus, technique and process for compact tension specimens of material harvested from nuclear reactor are described. Remote machining technique will be useful in specimen machining to evaluate changes in mechanical properties of materials harvested in high-radioactive reactor. Also, it is expected that various types of specimens can be machining by applying the developed machining technique in the future.

Mitochondrial genomes of three specimens of Gadus chalcogrammus Pallas 1,814 from Korea and Japan were completely analyzed by the primer walking method. They were 16,570~16,571 bp in length, each comprising 13 protein-coding genes, two ribosomal RNA genes, and 22 transfer RNA genes. Their gene orders were identical to those of conspecific specimens, but exhibited unique haplotypes. In the phylogenetic tree, the juvenile Korean and adult Japanese specimens were separated from the dominant clade composed of specimens from Japan, Korea, the Bering Sea, and the Arctic, including the adult Korean specimen.

Corrosion cells that simulates engineering barrier system have been stored in an aerobic KURT environment for 10 years, which were recovered and dismantled in 2021. The test specimens were compressed copper (Com. Cu), Cold spray copper (CSC Cu), Ti Gr.2, STS 304, and Cast nodular iron. The specimens were buffered by compact Ca-type Gyeongju bentonite (KJ-I) and compact Na-type Wyoming bentonite. And the corrosion cells were exposed to KURT groundwater at 30°C for about 10 years (3,675 days). As a result of the long-term experiment in aerobic environment, it was confirmed that Na-bentonite is more advantageous for inhibiting corrosion than Ca-bentonite. The corrosion thickness of the most specimens in Ca bentonite was slightly lower than in Na bentonite until the initial 500 days, but after 10 years, the corrosion thickness of copper and cast iron specimens in Na bentonite was clearly lower. The corrosion thickness of the copper specimen in Na bentonite was very low about 0.5 um in both Com. Cu and CSC Cu. Moreover, the corrosion thickness in Ca bentonite was very high about 4 um for Com. Cu and 6 um for CSC Cu. In the case of cast iron, the corrosion thickness in Na bentonite was about 13 um, and 15 um in Ca bentonite. The common feature of copper and cast iron specimens in Ca bentonite, which showed a high corrosion thickness, is the forming of a white mineral deposition layer on the specimen surface, which was presumed to be some kind of feldspar. On the other hand, it was found that the STS304 and Ti specimens were hardly corroded even after 10 years. In conclusion, when a white mineral deposition layer was formed on the specimen surface, the corrosion thickness always increased sharply than before, and thus it was estimated that the generation of the mineral deposition layer cause the increase of bentonite permeability, and rather the weakening of existing passive corrosion film.

Fused Deposition Modeling (FDM), also known as Fused Deposition Modeling (FFF), is the most widely used type of 3D printing at the consumer level. The FDM 3D printer extracts thermoplastic filaments such as ABS (Acrylonitrile Butadiene Styrene) and Polyactive Acid (PLA) through heated nozzles to dissolve the material. It works by applying layers of plastic to build platforms. Various demands for 3D printers increased, and among these demands, there was also a demand for various filament colors. ABS, one of the main filamentous materials for 3D printers, is easy to color in a variety of colors and has been studied to meet the needs of these users. Through quantitative measurements in this work, we confirm that color differences remain depending on the difference in placement on the 3D printer bad. In addition, the temperature of the specimen was measured at the start of 3D printing, during manufacturing, and at the completion of manufacturing, and the inner and central sides remained similar, but the outer sides were 5 degrees lower. These temperature differences accumulate as layers pile up, resulting in differences in weight or color, which in turn meet consumer and producer needs in the 3D printer industry.

Additive manufacturing technology, 3D printing, has been applied to various industrial fields. This production method is a production method with less material, cost and time savings, and less restrictions in shape, and is also making a leap forward in the field of eco-friendly product production. In particular, FDM (fused depositon modeling) method of extrusion lamination manufacturing is widely applied in products and medical fields. And as an alternative to mold manufacturing, it is widely used in manufacturing plastic products and parts. Therefore, this paper quantitatively and qualitatively analyzes the mechanical properties according to the processing factors of the specimen through the processing of the ABS tensile specimen printed by the FDM type 3D printer and derives the optimum value.

Since the outbreak of coronavirus disease 2019 (COVID-2019), the infection has spread worldwide due to the highly contagious nature of severe acute syndrome coronavirus (SARS-CoV-2). To manage SARS-CoV-2, the development of diagnostic assays that can quickly and accurately identify the disease in patients is necessary. Currently, nucleic acid-based testing and serology-based testing are two widely used approaches. Of these, nucleic acid-based testing with quantitative reverse transcription-PCR (RT-qPCR) using nasopharyngeal (NP) and/or oropharyngeal (OP) swabs is considered to be the gold standard. Recently, the use of saliva samples has been considered as an alternative method of sample collection. Compared to the NP and OP swab methods, saliva specimens have several advantages. Saliva specimens are easier to collect. Self-collection of saliva specimens can reduce the risk of infection to healthcare providers and reduce sample collection time and cost. Until recently, the sensitivity and accuracy of the data obtained using saliva specimens for SARS-CoV-2 detection was controversial. However, recent clinical research has found that sensitive and reliable data can be obtained from saliva specimens using RT-qPCR, with approximately 81% to 95% correspondence with the data obtained from NP and OP swabs. These data suggest that self-collected saliva is an alternative option for the diagnosis of COVID-19.

FDM 3D Printer is used in maker space for mass production by the maker. Makers desire to manufacture products in a variety of colors using ABS Filaments. The purpose of this study is to identify the relation between the color of resin and each position on the bed. So, when printed using the 3D Printer, we found out the difference in the colors that it appears depending on the position of the bed. To see the difference in color, basic, blue, yellow, white, and black were selected and the bed plate was divided into three sections. Specimens were measured to obtain delta E values between each sections by the chromatic differential system. Obtained delta values were analyzed by the NBS system. As a result, the delta E value of black was found to correspond to “Appreciable”. In most cases, delta E values between the middle and the outer or the inner and the outer was greater than values between the middle and the inner. Using Infrared Thermal Camera, We found that the color difference relates 3D printing positions and temperatures. As a result, the 3D printing bed positions should be considered when 3D printing mass production.

자연생태계에서 수집된 분변, 털 등 비침습적 시료는 야생 동물의 상태나 특성을 분석적으로 평가할 수 있는 좋은 재료가 된다. 특히 비침습적 시료에 대한 유전자 분석 결과는 야생동물의 유전학적, 생태학적 특성을 이해할 수 있는 생물학적 근거를 제공할 수 있다. 야생생물-특히 멸종위기야생생물 등-에 대한 분석에 있어 비침습 시료의 활용은 개체의 포획, 채혈, 조직 수집 등에 따른 생체 손상 없이 진행될 수 있는 좋은 시료가 된다. 본 연구는 우리나라에서 멸종위기 야생생물 Ⅰ급으로 지정되어 있는 산양 집단의 성별 구조분석과 생태복원을 위한 기초자료 확보를 위하여 성 판별을 위한 새로운 분석기법을 마련하고자 하였다. 산양의 분자적 성판별을 위하여 포유동물인 산양의 성염색체(X-, Y-염색 체)에서 공통적으로 암호화되어 있는 zinc finger-X, -Y(ZFX, ZFY) 유전자와 수컷에서만 출현하는 sex-related region Y (SRY) 유전자의 서열을 이용하여 중합효소연쇄반응(polymerase chain reaction, PCR)을 위한 시발체(primer)를 고안하였다. 새롭게 제작한 시발체들과 기존 연구에서 보고된 포유동물-범용 시발체들을 사용하여 강원도 오대산 국립공원과 서울 인근에 위치한 용마산에서 수집된 산양 비침습적 시료(분변, 털)와 혈액 유래의 DNA를 대상으로 PCR 시험을 수행하였다. 기존에 보고된 범용 시발체를 이용한 시험결과에서는 대다수의 시료에서 비특이적인 PCR 증 폭산물들이 같이 출현하였고, 암-수를 판독할 수 있는 명확한 실험결과를 얻을 수 없었다. 본 연구에서 고안한 시발체를 이용하여 혈액 유래의 DNA를 대상으로 시험한 결과, SRY 시험에서 수컷에서는 단 하나의 PCR 증폭산물이 관찰되고, 암컷에서는 관찰되지 않았다. ZFX-ZFY 시험결과에서는 길이가 다른 두 개의 산물이 수컷에서 관찰되고, 암컷은 단 하나의 PCR 산물만 관찰되었다. 또한 SRY 유전자 성판별 결과와 ZFX-ZFY 성판별 결과는 정확히 일치하였다. 비침습 적 시료에 대한 성판별 시험에서 SRY 체계와 ZFX-ZFY 체계에서 시료들이 암-수로 구분되었고, 대부분의 시료에서 SRY 시험결과와 ZFX-ZFY 시험결과가 일치하였다. 분석결과 중 2 건의 시료에서 ZFX 또는 ZFY 유전자 절편이 검출되지 않는 양상을 보여, 이들 시료에 대하여 DNA 분자 barcoding에 이용되고 있는 미토콘드리아 DNA(mitochondrial DNA, mtDNA)의 cytochrome oxydase I (COI) 유전자 서열을 추가로 분석하였다. 해당 시료들은 서열의 일부 또는 전체적으로 DNA 서열이 이질적(heteroplasmic)인 현상을 나타내었으며, 이는 증폭된 유전자 서열이 하나의 기원에서 유래된 것이 아니라, 2 개체 이상이거나 2 종 이상에서 유래되었음을 의미한다. 결과적으로 동종 또는 다른 종에 의한 오염이 부분적으로 분자 수준에서의 성 판별 시험을 저해할 수 있음을 보여주는 결과이다. 그럼에도 불구하고, 이 연구를 통해 산양 비침습 시료에서 암-수성별에 대한 정보를 얻을 수 있었다. 본 연구에서 새롭게 고안한 ZFX-XFY, SRY 유전자에 대한 PCR 시험방법은 기존에 고안된 방식에 비해 더 좋은 효율을 나타내었으며, 오대산국립공원지역과 서울 용마산에서 수집한 산양 비침습 시료(분변, 털)에서 암-수성별에 대한 정보를 확인할 수 있었다. 본 연구에서 고안한 산양 성판별 시험방법을 현재 지역적으로 파편화된 양상을 나타내는 지역별 산양집단의 성비 분석에 적용한다면, 포획, 채혈, 조직 수집 등을 통한 산양 생체에 대한 피해 없이 비침습 시료를 이용하여 집단의 성비를 산출할 수 있는 자료를 확보 할 수 있을 것이다. 또한 집단의 성비 정보는 지역별로 산재 되어 분포하고 있는 개별적인 산양집단의 보호와 생태복원을 위한 전략마련에 필요한 가치 있는 생태정보를 제공할 수 있을 것으로 기대된다.

농림축산검역본부에서는 수입식물 검역과정, 현지조사, 연구사업 등을 통해 다양한 병해충 표본들이 확보되고 있으며, 2016년도부터 병해충 표본자원의 DB구축사업을 실시하고 있다. 농림축산검역본부의 해충표본실에는 2018년도 9월까지 약 6,400점의 표본 등록 및 바코드화가 완료되었으며, 올해까지 총 7,000점의 표본이 등록될 것으로 예상된다. 그 중 노린재목(Hemiptera)이 5,500점으로 전체의 85%를 차지하고 딱정벌레목(Coleoptera)이 377점으로 6%, 파리목(Diptera)이 188점으로 3%를 차지한다. 국제적으로 생물자원의 중요성과 확보 경쟁이 치열한 상황에서 생물표본가치의 증가 및 자료 구축을 통해 앞으로의 첨단 동정기술 개발과 동정매뉴얼 제작 및 업데이트를 위한 필수적인 재료로써 활용될 것으로 기대된다.