FRP 복합재 중 CFRP(Carbon Fiber Reinforcement Plastic)는 현재 Rebar, Plate, Grid 등 다양한 형태로 RC 구조물에 내‧외부 보강재로써 사용되고 있다. 이 중 CFRP Grid의 경우 국내에서 상용화가 되지 않아 다른 형태의 보강재보다 성능 분석 및 평가 기준이 미흡한 실정이다. 이에 따라 본 연구에 서는 Grid의 Strand, 경계조건, ASTM 고정장치의 유무 등 다양한 실험을 통하여 CFRP 그리드의 인 장 성능평가를 진행하였다. 선행 연구에서는 CFRP Grid의 인장시험 고정단의 경계조건에 따른 영향 성 분석을 위해 ASTM D7205 및 ASTM D6637에 따라 Tap-Tap (Type 1), Tap-Mortor (Type 2) 로 구성하여 인장시험을 수행하였으며, 시편의 파단 형상 및 시험 결과값이 가장 안정적인 Type 2를 CFRP Grid의 고정단 경계조건으로 설정하였다. 이러한 선행 연구를 바탕으로 고온 노출에 따른 CFRP 그리드의 인장 성능시험 평가를 진행하였으며, 인장시험은 만능재료시험기 및 고성능 카메라를 활용하여 최대 응력과 탄성계수를 도출하였다. 온도는 FRP의 전이온도인 150℃ 이내의 130℃에서 각 Case 별 5개의 시편을 70분(Case 2), 100분(Case 3), 120분(Case 4), 150분(Case 5) 노출한 후, 고온 에 노출하지 않은 시편(Case 1)과 비교하였다. 실험 결과, Case 5와 Case 1을 비교하여 인장강도와 탄성계수는 각각 최대 51.32%, 44.4% 감소하였다. 결론적으로 고온 환경에서 지속적으로 노출될 경 우, CFRP Grid의 성능이 최대 절반 수준으로 감소 되며 RC 부재 내‧외부에 보강 시에 고온 조건을 면밀히 검토하여 성능 감소를 최소화할 필요가 있다고 판단된다.

Cars using diesel have always had problems with reducing exhaust fumes, and have been studied steadily in this regard. There were studies on the remanufacturing effect of DOC catalyst deactivated by diesel vehicle smoke reduction device, analysis of vehicle fire accident cases caused by damage to diesel vehicle smoke reduction device, and related studies on the remanufacturing effect of diesel vehicle smoke reduction device DPF. This study also developed a burner system in a smoke reduction device suitable for exhaust engines to completely burn smoke generated by institutions using diesel engines in low-temperature exhaust gases. Following the development of the existing high-performance heater, burner structure capable of maintaining ignition state in exhaust flow, pulsation generated by diesel engines, and exhaust flow control unit, the actual configuration, function and effect of the device, development contents, basic data and abnormalities of the vehicle, and comparison with other developed products.

The aerospace and power generation industries have an increasing demand for high-temperature, highstrength materials. However, conventional materials typically lack sufficient fracture toughness and oxidation resistance at high temperatures. This study aims to enhance the high-temperature properties of Nb-Si-Ti alloys through ball milling. To analyze the effects of milling time, the progression of alloying is evaluated on the basis of XRD patterns and the microstructure of alloy powders. Spark plasma sintering (SPS) is employed to produce compacts, with thermodynamic modeling assisting in predicting phase fractions and sintering temperature ranges. The changes in the microstructure and variation in the mechanical properties due to the adjustment of the sintering temperature provide insights into the influence of Nb solid solution, Nb5Si3, and crystallite size within the compacts. By investigating the changes in the mechanical properties through strengthening mechanisms, such as precipitation strengthening, solid solution strengthening, and crystallite refinement, this study aims to verify the applicability of Nb-Si-Ti alloys in advanced material systems.

매미나방(Lymantria dispar)은 나비목(Lepidoptera) 독나방과(Lymantriidae)에 속하는 해충으로 매미나방은 한국, 일본, 시베리아, 유 럽, 북아메리카 등에 분포하며, 주로 배나무, 사과나무, 블루베리 등의 식물을 가해하는 광식성 해충이다. 매미나방은 수목해충으로 관리되어 왔 으나 최근 산림 발생지 인접 농경지로 유입 빈도가 높아지면서 방제 대책이 수립되지 않은 농작물에 피해가 심하다. 본 연구는 매미나방(L. dispar)의 방제기술의 일환으로 매미나방 발육에 미치는 온도의 영향을 알아보기 위해 2021년 전라남도 장흥군 황금측백나무에서 채집한 알집을 이용해 18, 21, 24, 27, 30, 33°C (14L:10D, 상대습도 60±5%) 항온조건에서 온도별, 발육단계별 발육기간을 조사하였다. 매미나방 유충의 발 육속도는 온도가 높을수록 빨라졌으나, 매미나방 유충의 생존율이 33°C에서 가장 낮게 나타났다. 따라서 발육적온은 30°C였으며, 30°C에서 총 발육기간은 암컷 43.8일, 수컷 42.5일 소요되었다. 암컷과 수컷 발육영점온도는 각각 13.1°C, 12.5°C, 유효적산온도는 각각 641.1 DD, 657.8 DD였다.

좁은가슴잎벌레는 십자화과작물을 가해하는 해충으로 알려져 있다. 본 연구는 온도가 좁은가슴잎벌레의 발육단계별 발육기간, 성충의 수 명과 산란특성에 미치는 영향을 파악하고자 성충 전 발육단계는 15, 20, 25, 27.5°C에서, 성충은 10, 15, 20, 25, 27.5°C 항온조건에서 조사하였 다. 알과 유충은 항온조건에서 다음 발육 단계로 성공적으로 발육하였다. 알, 유충, 번데기의 발육기간은 온도가 상승할수록 짧아지는 경향을 보 였다. 좁은가슴잎벌레의 발육영점온도, 유효적산온일도는 선형회귀분석을 통해 추정하였으며 알에서 성충출현까지 발육영점온도와 유효적산온 일도는 8.7°C와 344.73DD였다. 좁은가슴잎벌레 발육단계별 최저, 최고 온도의 한계는 Briere함수를 이용하여 추정하였으며 알에서 성충출현 까지 최저, 최고한계는 5.3°C와 40.4°C였다. 성충은 10°C와 27.5°C 범위에서 산란이 가능하였고 21.7°C에서 최대 약 627.5개의 알을 낳는 것 으로 추정되었다. 노화율, 나이별 생존율, 나이별 누적산란율, 온도의존 산란수와 관련된 성충모델들을 작성하였다. 본 연구에서 제시한 온도발육 모형과 성충산란모형은 좁은가슴잎벌레 개체군동태를 이해하는데 유용할 것이며 십자화과작물의 종합적 해충군관리체계를 마련하는데 기초자 료로 활용될것으로 기대된다.

Cars using diesel have always had problems with reducing exhaust fumes, and have been studied steadily in this regard. There were studies on the remanufacturing effect of DOC catalyst deactivated by diesel vehicle smoke reduction device, analysis of vehicle fire accident cases caused by damage to diesel vehicle smoke reduction device, and related studies on the remanufacturing effect of diesel vehicle smoke reduction device DPF. This study is also to develop an exhaust flow control unit suitable for an exhaust engine to completely burn smoke generated by an engine using a diesel engine in a low temperature exhaust gas. The main systems to be developed are high-performance heaters, burner structures that can maintain ignition in exhaust flows, and exhaust flow control units that reduce exhaust gas backflow effects caused by diesel engines.

ars using diesel have always had problems with reducing exhaust fumes, and have been studied steadily in this regard. There were studies on the remanufacturing effect of DOC catalyst deactivated by diesel vehicle smoke reduction device, analysis of vehicle fire accident cases caused by damage to diesel vehicle smoke reduction device, and related studies on the remanufacturing effect of diesel vehicle smoke reduction device DPF. This study also developed an optimized system for complete combustion of smoke generated by institutions using diesel engines in low-temperature exhaust gases. The main systems to be developed are high-performance heaters, burner structures that can maintain ignition in exhaust flows, and exhaust flow control units that reduce exhaust gas backflow effects caused by diesel engines.

This study was conducted to develop a model for predicting the growth of kimchi cabbage using image data and environmental data. Kimchi cabbages of the ‘Cheongmyeong Gaual’ variety were planted three times on July 11th, July 19th, and July 27th at a test field located at Pyeongchang-gun, Gangwon-do (37°37′ N 128°32′ E, 510 elevation), and data on growth, images, and environmental conditions were collected until September 12th. To select key factors for the kimchi cabbage growth prediction model, a correlation analysis was conducted using the collected growth data and meteorological data. The correlation coefficient between fresh weight and growth degree days (GDD) and between fresh weight and integrated solar radiation showed a high correlation coefficient of 0.88. Additionally, fresh weight had significant correlations with height and leaf area of kimchi cabbages, with correlation coefficients of 0.78 and 0.79, respectively. Canopy coverage was selected from the image data and GDD was selected from the environmental data based on references from previous researches. A prediction model for kimchi cabbage of biomass, leaf count, and leaf area was developed by combining GDD, canopy coverage and growth data. Single-factor models, including quadratic, sigmoid, and logistic models, were created and the sigmoid prediction model showed the best explanatory power according to the evaluation results. Developing a multi-factor growth prediction model by combining GDD and canopy coverage resulted in improved determination coefficients of 0.9, 0.95, and 0.89 for biomass, leaf count, and leaf area, respectively, compared to single-factor prediction models. To validate the developed model, validation was conducted and the determination coefficient between measured and predicted fresh weight was 0.91, with an RMSE of 134.2 g, indicating high prediction accuracy. In the past, kimchi cabbage growth prediction was often based on meteorological or image data, which resulted in low predictive accuracy due to the inability to reflect on-site conditions or the heading up of kimchi cabbage. Combining these two prediction methods is expected to enhance the accuracy of crop yield predictions by compensating for the weaknesses of each observation method.

Cars using diesel have always had problems with reducing exhaust fumes, and have been studied steadily in this regard. There were studies on the remanufacturing effect of DOC catalyst deactivated by diesel vehicle smoke reduction device, analysis of vehicle fire accident cases caused by damage to diesel vehicle smoke reduction device, and related studies on the remanufacturing effect of diesel vehicle smoke reduction device DPF. This study also developed a burner system in a smoke reduction device suitable for exhaust engines to completely burn smoke generated by institutions using diesel engines in low-temperature exhaust gases. The main systems to be developed are high-performance heaters, burner structures that can maintain ignition in exhaust flows, and exhaust flow control units that reduce exhaust gas backflow effects caused by diesel engines.

Cars using diesel have always had problems with reducing exhaust fumes, and have been studied steadily in this regard. There were studies on the remanufacturing effect of DOC catalyst deactivated by diesel vehicle smoke reduction device, analysis of vehicle fire accident cases caused by damage to diesel vehicle smoke reduction device, and related studies on the remanufacturing effect of diesel vehicle smoke reduction device DPF. This study is also to develop a burner structure in a smoke reduction device suitable for an exhaust engine to completely burn smoke generated by an engine using a diesel engine in a low-temperature exhaust gas. The main systems to be developed are high-performance heaters, burner structures that can maintain ignition in exhaust flows, and exhaust flow control units that reduce exhaust gas backflow effects caused by diesel engines.

In order to respond to environmental pollution, developed countries, including Korea, have begun to conduct research to utilize hydrogen energy. For mass transfer of hydrogen energy, storage as liquid hydrogen is advantageous, and in this case, the volume can be reduced to 1/800. As such, the transportation technology of liquefied hydrogen for ships is expected to be needed in the near future, but there is no commercialized method yet. This study is a study on the technology to test the performance of the components constituting the membrane type storage container in a cryogenic environment as a preparation for the above. It is a study to find a way to respond by analyzing in advance the problems that may occur during the shear test of adhesives. Through this study, the limitations of ISO4587 were analyzed, and in order to cope with this, the specimen was supplemented so that fracture occurred in the adhesive, not the adhesive gripper, by using stainless steel, a low-temperature steel, to reinforce the thickness. Based on this, shear evaluation was performed under conditions lowered to minus 243℃, and it was confirmed that the breaking strength was higher at cryogenic temperatures.

LiCl-KCl eutectic possesses unique properties such as a low melting point, high thermal conductivity, and good electrical conductivity. These properties make it suitable for various applications, including nuclear power generation, pyroprocessing in nuclear waste management, and thermal energy storage systems. In most experiments using LiCl-KCl, the molten salt composition is an important factor; therefore, periodic analysis through sampling is necessary for monitoring compositional changes. Although manual sampling is typically used, it is time-consuming and can introduce errors due to low reproducibility. To address this issue, we have developed an automatic molten salt sampling device using the cold-finger method. This method involves immersing the tip of a tungsten rod in hightemperature LiCl-KCl, removing it after a few seconds, and allowing the adhered molten salt to solidify instantly. A collector then scratches and drops the solidified sample. These processes are carried out automatically using servo motors, enabling the sampling device to move around the molten salt system. We have optimized the sampling conditions, such as insertion and withdrawal rate, immersion time, and the interval between continuous sampling, based on the molten salt temperature. The temperature was set between 500°C and 850°C, considering the operating temperatures of the applications. In addition to sampling speed, the sampling depth is a key condition for determining the sampling mass. Therefore, we examined the amount of sample depending on the sampling depth and, particularly, considered the change in salt height when sampling is performed continuously. As a result, we determined the number of sampling iterations required to reach the target sample mass. Furthermore, to minimize the initial salt loss, we noted that sampling from the salt surface resulted in less representative samples. To determine the reliability, we compared the results of surface sampling with those obtained when sampling at the middle of the salt. This study will enable highly reproducible and reliable sampling by providing a prototype for an automatic sampling device for molten salt along with guidelines.

콩줄기명나방은 콩과작물 특히 팥을 가해하는 해충으로 알려져 있다. 본 연구는 온도가 콩줄기명나방의 발육단계별 발육기간, 성충의 수명 과 산란특성에 미치는 영향을 파악하고자 7, 10, 13, 16, 19, 22, 25, 28, 31, 34, 36°C 항온조건에서 조사하였다. 알과 유충은 7, 10, 13°C를 제 외한 항온조건에서 다음 생애단계로 성공적으로 발육하였다. 알, 유충, 번데기의 발육기간은 온도가 상승할수록 짧아지는 경향을 보였다. 콩줄기 명나방 발육단계별 발육 최저, 최고 한계는 LRF와 SSI모델을 이용하여 계산하였고 발육영점온도와 유효적산온일도는 선형회귀분석을 이용하 였다. 1령 유충 부화부터 성충출현까지의 발육영점온도와 유효적산온일도는 13.5°C와 384.5DD로 추정되었다. SSI모델을 이용한 부화부터 성 충출현까지 발육 최저 및 최고온도는 19.4°C과 39.8°C였고 이들간의 차이 즉 발육적정온도범위는 20.4°C였다. 성충은 16°C와 34°C 범위에서 부화하는 알을 생산하였고, 25°C에서 최대 약 416마리의 자손을 낳았다. 노화율, 나이별 생존율, 나이별 누적산란율, 온도의존 산란수에 관련된 성충모델들이 작성되었다. 본 연구에서 제시한 온도발육모형과 산란모형은 야외에서 콩줄기명나방의 개체군동태를 이해하고 콩과작물의 종합적 인 해충군관리체계를 마련하는데 기초기반자료로 활용될 것으로 기대된다.

콩명나방은 콩과작물 특히 팥을 가해하는 해충으로 알려져 있다. 본 연구는 콩명나방의 생물적 특징을 알아보기 위해 발육단계별 발육기 간, 성충의 수명과 번식능력을 13, 16, 19, 22, 25, 28, 31, 34°C 항온조건에서 조사하였다. 알은 모든 항온조건에서 부화하였고 유충은 16~ 31°C 온도조건에서 성공적으로 성충까지 발육을 완료하였다. 알의 발육기간은 31°C까지 온도가 상승할수록 짧아지다가 이후 온도에서 길어지 는 경향을 보였다. 유충, 번데기의 발육기간과 성충수명은 온도가 상승할수록 감소하였다. 콩명나방 발육단계별 발육 최저, 최고 한계는 LRF와 SSI모델을 이용하여 계산하였고 발육영점온도와 유효적산온일도는 선형회귀분석을 이용하였다. 1령 유충 부화부터 성충출현까지의 발육영점온 도와 유효적산온일도는 12.8°C와 280.8DD였다. SSI모델을 이용하여 추정한 부화부터 성충출현까지 발육최저 및 최고온도는 14.2°C과 31.9°C였고 이들간의 차이 즉 발육적정온도범위는 17.7°C였다. 온도와 관련된 콩명나방 성충의 생존, 수명, 산란기간, 산란수 자료들을 이용하 여 산란모형을 작성하였다. 본 연구에서 제시한 온도발육모형과 산란모형은 야외에서 콩명나방의 개체군동태를 이해하고 콩과작물의 종합적인 해충군관리체계 확립에 기여할 것으로 보인다.