거저리는 식품으로 사용되기 때문에 유충기가 오래 지속되면 더 좋다. 반면에 거저리의 개체수 유지를 위 해 성장을 가속화하기 위해서는 유충이 빨리 성충이 되면 더 좋다. 이 연구에서는 개체군 밀도가 거저리의 발달 시 간에 미치는 영향을 구명하였다. 이를 위해 상단 7 cm, 하단 5 cm, 높이 3 cm 크기의 용기를 사용했다. 거저리는 용기 당 1, 2, 5, 10, 20마리의 밀도로 용기에서 서식하였다. 용기에 밀기울 1 g을 넣고 거저리의 먹이 여부에 따라 라벨을 붙였다. 실험은 세 번 반복되었다. 모든 실험에서 개체군 밀도가 높을수록 유충에서 번데기로의 변환 시간이 짧았 지만 번데기에서 성충으로 변환되는 시간은 크게 다르지 않았다. 또한 먹이가 있는 그룹에서 번데기로의 변환 시간 이 단축되었지만, 성충으로 변환되는 시간에는 차이가 없었다. 이 연구 결과는 유충기를 연장하기 위해 더 낮은 밀 도가 필요하고 더 빠른 속도로 성충이 필요하다면 밀도가 더 높아야 한다는 것을 보여주었다. 결론적으로 거저리의 발달 시간은 개체수 밀도에 의해 제어할 수 있을 것이다.
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.
This study examined the influence of social responsibility awareness (economic and social-environmental responsibility) and trust in corporate social responsibility on sustainable diets. The subjects of the study were 468 university students. The main research results were as follows. First, the social responsibility awareness of the study subjects was 4.03±0.72 points for economic responsibility and 3.48±0.81 points for social-environmental responsibility. An awareness of economic responsibility showed differences according to gender. Trust in corporate social responsibility was 3.62±0.61 points, and there was no statistical significance based on gender. Second, the level of a sustainable diet was food safety and consideration (4.06±0.63), knowledge of the environment and diet (3.94±0.68), understanding of the food circulation system (3.45±0.77), and healthy diet (3.26±0.89). Among the factors influencing a sustainable diet, female students had higher attitudes toward food safety and consideration and understanding of the food circulation system than male students. Third, the social responsibility awareness (economic responsibility and social-environmental responsibility) and corporate social responsibility trust variables influenced university students’ sustainable diet. Among these, social-environmental responsibility awareness had the highest influence.
Despite advancements in therapeutic approaches, radiotherapy and cisplatin-based chemotherapy remain primary noninvasive treatments for patients with oral squamous cell carcinoma (OSCC). Moreover, the 5-year survival rate for patients with OSCC has remained almost unchanged for several decades, and many side effects of chemotherapy still exist. In this study, three-dimensional (3D) models of OSCC were established using fibroblasts, and the efficacy of various biological inhibitors was evaluated. A culture of epithelial cells with two types of fibroblasts (hTERT-hNOFs and cancer-associated fibroblasts) within a type I collagen matrix resulted in the formation of a continuous layer of tightly packed cells compared to models without fibroblasts. Furthermore, the effects of biological chemicals, including Y27632, latrunculin A, and verteporfin, on these models were investigated. The stratified formation of the epithelial layer and invasion in OSCC 3D-culture models were effectively inhibited by verteporfin, whereas invasion was weakly inhibited by Y27632 and latrunculin. Collectively, the developed OSCC 3D-culture models established with fibroblasts demonstrated the potential for drug screening, with verteporfin showing promising efficacy.
주변 국가인 태국, 캄보디아, 베트남, 라오스 등에서 벼멸구(Nilaparvata lugens)와 흰등멸구(Sogatella furcifera)를 채집하던 중, 벼멸구와 형태가 아주 유사한 이삭멸구(N. muiri)와 벼멸구붙이(N. bakeri), 그리고 흰등 멸구와 형태가 아주 유사한 흰등멸구붙이(S. kolophon), 피멸구(S. vibix) 그리고 애멸구(Laodelphax striatellus)가 동시에 채집이 되는 등 형태적 차이점이 거의 없어 전문가도 쉽게 구분하지 못하는 문제가 있음이 확인되었다. 따라서 형태가 유사한 상기 멸구류의 종 동정을 확실히 할 수 있는 PCR용 프라이머의 개발을 위해 벼멸구 및 흰등멸구의 미토콘드리아 내 COI 영역을 특이적으로 검출할 수 있는 프라이머 세트를 제작하고 종 동정 효과를 확인하였다.
The growth characteristics according to temperature conditions were investigated in the breeding room of the Sericulture & Entomology Experiment Station for Oriental garden crickets(Teleogryllus emma Ohmachi et Matsuura) and Modeagali-crickests(Loxoblemmus doenitzi Stein) collected from the lawns of Byeonsan-myeon, Buan-gun, Jeollabuk-do. The temperature conditions were 6 treatments from 15°C to 40°C at 5°C intervals using a multi-incubator, and the development period and mortality rate by age were compared using the 28°C breeding room conditions as a control. For T. emma, the higher the temperature, the shorter the total development period was, and the same trend was observed for the growth period by age stage. However, at low temperatures of 15°C and 20°C, all died after the third instar, and at high temperatures above 35°C, all died during development. At 25°C and 30°C, they developed normally, and the mortality rate was about 25%. The L. doenizi had the same tendency as the T. emma, with the higher the temperature, the shorter the development period. The total development period was 57.7 days at 25°C, which was similar to the T. emma's 55.9 days, and the mortality rate was the lowest at 44% at 25°C.
In 2022, research for native prokaryotic species in Korea reported 10 unrecorded bacterial strains affiliated to phyla Actinomycetota, Bacillota, and Pseudomonadota. The strains formed monophyletic clades with the most closely related species (with ≥98.7% sequence similarity) in the 16S rRNA gene sequencing. Among them, four species of the phylum Actinomycetota, two species of the phylum Bacillota, and four species of the phylum Pseudomonadota have not been reported in Korea, suggesting unrecorded species in Korea. Information on strains such as Gram staining reaction, colony and cell morphology, biochemical characteristics, and isolation sources were provided in the species description.
본 연구는 전라북도 남원시, 장수군과 경상남도 함양군의 경계에 위치한 백두대간 봉화산의 관속식물상을 파악하여, 생물다 양성 보존 및 외래식물의 확산 방지를 위한 기초자료로 활용하기 위하여 조사를 실시하였다. 국립수목원 산림생물표본관에 소장된 봉화산 표본 검토와 함께, 2020년 4월부터 2023년 7월까지 총 15회에 걸쳐 현지조사를 수행하였다. 그 결과, 본 조사 지역의 관속식물은 97과 279속 409종 16아종 32변종 9품종의 총 466분류군으로 조사되었다. 이 중 특산식물은 8분류군, 적색목록 중 취약(VU)에 속하는 종은 1분류군으로 확인되었다. 식물구계학적 특정식물종은 총 57분류군으로 Ⅴ등급에 1분류 군, Ⅲ등급에 9분류군, Ⅱ등급에 14분류군, Ⅰ등급에 33분류군이 각각 발견되었으며, 외래식물은 24분류군, 그리고 생태계교 란야생종은 1분류군이었다. 분류군의 유용성 조사에서 식용 353분류군, 섬유용 3분류군, 약용 71분류군, 관상용 21분류군, 목초용 108분류군, 공업용 2분류군, 잡용 7분류군, 용재용 11분류군으로 나타났다.
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.
재생에너지의 보급과 기후변화를 대응하기 위한 해결책으로 수소에너지에 대한 관심이 늘어나고 있다. 수소는 미 이용 전력을 대용량 장주기로 저장하기에 가장 적합한 수단이며 이러한 수소를 생산하는 기술 중 수전해는 물에 전기에너지 를 인가하여 수소를 생산하는 친환경적 수소생산 기술로 알려져 있다. 수전해의 구성 요소 중 분리막은 음극과 양극을 물리 적으로 분리할 뿐만 아니라 생성되는 수소와 산소의 섞임 현상을 방지하며 이온의 전달을 가능하게 하는 복합적인 역할을 수 행한다. 특히 기존의 수전해 기술들의 단점을 보완할 수 있는 차세대 음이온 교환막 수전해에서의 핵심은 우수한 음이온 교 환막을 확보하는 것이다. 높은 이온 전도성과 알칼리 환경에서 우수한 내구성을 동시에 가지려는 많은 연구들이 진행되고 있 으며 다양한 소재에 대한 탐색이 이루어지고 있다. 본 총설에서는 상용 블록 공중합체인 Polystyrene-b-poly(ethylene- co-butylene)-b-polystyrene (SEBS)를 기반으로 하는 음이온 교환막에 대한 연구에 대해 살펴보며 최신 연구 동향과 앞으 로 나아가야할 점에 대해 논하고자 한다.
The number of dismantled nuclear facilities is increasing globally. Dismantling of nuclear facilities generates large amount of waste such as concrete, soil, and metal. Concrete waste accounts for 70% of the total amount of waste. Since hundreds of thousansds of tons of concrete waste generated, securing technology of reduction and recycling of waste is emerging as a very important issue. The objective of this study is to synthesize geopolymer using inorganic materials from cement fine powder in concrete waste. Dismantled concrete waste contains a large amount of calcium silicate hydrate(C-S-H), Ca(OH)2, SiO2, etc., which is an inorganic material required for the synthesis of geopolymer. SiO2 affects the compressive strength of the geopolymer and Ca(OH)2 affects the curing rate. A high concentration of alkali solution is used as an alkali activator, and alkali activator is necessary for the polymerzation reaction of metakaolinite. The experiment consists of three steps. The first step is to react with concrete waste and hydrochloric acid to extract ions. In the solid after filtration, SiO2 and Al2O3 are composed of 84.10%. It can be used instead of commercial SiO2 required for the synthesis of geopolymer. The second step is to add NaOH up to pH 10, impurities can be removed to extract Ca(OH)2 with high purity. The final step is to add NaOH up to pH 13, and Ca(OH)2 extraction. The alkali solution generated after the last reaction can be recycled into an alkali activator during the synthesis of the geopolymer. If dismantled concrete waste is recycled during geopolymer synthesized, the volume reduction rate of dismantled concrete waste is more than 50%. If you put the radioactive waste in the recycled solidification materials synthesis from concrete waste by dismantling of nuclear facilities, it is possible to reduce the amount of waste generated and disposal costs.
Kori-1, the nuclear power plants in South Korea, first started operation in April 1978 and was suspended permanently in 2017. The saturation rate time of spent nuclear fuel generated by major nuclear power plants operating in Korea are getting closer. If we fail to dispose spent nuclear fuel, which is equivalent to high-level radioactive waste, the nuclear power plants will have to be shutdown. High-level radioactive waste is permanently disposed through a deep geological disposal system because it contains long-term half-life nuclides and emits high energy. To select the deep geological disposal site and construct the disposal facilities, it is necessary to establish appropriate regulatory policies accordingly. The status of database construction in OECD-NEA, NRC, SITEX, and IAEA, which provides safety regulations for deep geological disposal system, stipulates each requirement for dismantling nuclear power plants. However, details such as specific figures are not specified, and guidelines for the disposal of high-level radioactive wastes are not clearly distinguished. In Korea, the CYPRUS program, an integrated database system, has been developed to support comprehensive performance evaluation for high-level waste disposal. However, due to several difficult situations, maintenance and upgrades have not been performed, so the research results exist only in the form of raw data and the new research results have not been reflected. Other than that, there is no preemptive basis for regulating the deep geological disposal system. With real-time database, we can develop a regulatory system for the domestic deep disposal system by systematically analyzing the regulatory condition and regulatory case data of international organizations and foreign leading countries. The database system processed and stored primary data collected from nuclear safety reports and other related data. In addition, we used relational database and designed table to maximize time and space efficiency. It is provided in the form of a web service so that multiple users can easily find the data they want at the same time. Based on these technologies, this study established a database system by analyzing the legal systems, regulatory standards, and cases of major foreign leading countries such as Sweden, Finland, the United States, and Japan. This database aims to organize data for each safety case component and further prepare a safety regulatory framework for each stage of development of disposal facilities suitable for the domestic environment.
본 연구에서는 갈색날개매미충(R. sublimata)의 생물적 방제를 위한 기초정보를 마련하고자 알 기생천적인 날개 매미충알벌 (P. ricaniae)의 분포확산 및 월동 특성을 조사 한 결과를 보고하였다. 날개매미충알벌은 경기도, 충청남북도, 전라남북도 및 경상남도 일부 지역에 분포하는 것으로 조사되었다. 날개매미충알벌은 서남쪽 평야지대에 더 많이 발생하였으나, 시간의 경과에 따라 갈색날개매미 충의 확산에 맞춰 점차 동북쪽 지역으로 발생 범위가 확산하는 경향을 보였다. 날개매미충알벌의 야외 기생율은 1~8% 정도로 순천에서 가장 높았고, 다음으로 구례, 공주 순으로 나타났다. 날개매미충알벌은 9월부터 갈색날개매미충의 난 속에서 알 상태로 겨울을 보내고, 다음 해 6월부터 발육을 시작하여 성충으로 우화하였다. 날개매미충알 벌의 내한성은 알 상태에서 가장 높았다