온실가스 배출량을 최소화하기 위하여 가열 없이 생산이 가능한 상온 아스팔트 포장 공법도 2000년 초부터 개발되어 활용되고 있으 나, 기술적 한계로 인해 성능 확보가 어려워 대부분 기층용으로 활용중에 있다. 상온 아스팔트 혼합물은 유화아스팔트를 사용하는데 양생하는 동안 혼합물 내부에 있는 물이 증가됨에 따라 혼합물 내부의 높은 공극률이 발생하게 되어 포장의 성능을 확보하는데 한계 가 있다. 따라서 본 연구에서는 유화 아스팔트 내 아스팔트 고형분 함량을 증가시켜 물 함량을 최소화함으로서, 양생시간을 단축하고 낮은 공극률 확보를 통한 상온 아스팔트 혼합물의 성능의 변화를 평가하였다. 시험결과, 고형분 함량이 변화에 따라 공극률 및 간접인 장강도, 터프니스 물성이 변화가 나타났다. 하지만 고함량 고형분의 유화 아스팔트를 상온 아스팔트 혼합물에 적용하기 위해서는 최적 함수비 결정방식 및 양생방식 등에 대한 추가적인 연구가 필요한 것으로 나타났다.

Rapeseed (Brassica napus L.) oil is mostly refined oil (RO). However, with increasing interest in health, the consumption of cold-pressed oil (CPO) without chemical refining is increasing in Korea. In this study, quality characteristics of CPO from rapeseed varieties ‘Jungmo7001’, ‘Jungmo7002’, ‘Jungmo7003’,and ‘Yuryeo’were evaluated and compared with RO, a commercial product. L-value and a-value were lower while b-value was significantly higher for CPO than those for RO. Analysis of fatty acid compositions of each oil revealed that CPO from ‘Yuryeo’contained the highest oleic acid at 74%. Analyses of contents of bioactive compounds in CPOs and RO revealed that contents of tocopherol, β-carotene, and canolol were the highest in CPOs from ‘Jungmo7003’, ‘Jungmo7002’, and ‘Jungmo7001’at 55.5, 0.3, and 0.2 mg/100 g, respectively. In addition, CPOs contained higher contents of bioactive compounds than RO, suggesting that CPO could provide health benefits. The induction period of CPOs measured using Rancimat were 9∼52% longer than that for RO, indicating that CPOs had a higher oxidative stability under given conditions. These results could be used to obtain basic data on quality of domestic rapeseed varieties.

This study pioneers a transformative approach of discarded orange peels (Citrus sinensis) into highly porous carbon, demonstrating its potential application in energy storage devices. The porous carbon structure offers a substantial surface area, making it conducive for effective ion adsorption and storage, thereby enhancing capacitance. The comprehensive characterization, including X-ray diffraction, Fourier transform infrared, Raman spectroscopy, field emission scanning electron microscopy, and XPS verifies the material’s suitability for energy storage applications by confirming its nature, functional groups, graphitic structure, porous morphology and surface elemental compositions. Moreover, the introduced plasma treatment not only improves the material’s intensity, bending vibrations, and morphology but also increases capacitance, as evidenced by galvanostatic charge–discharge tests. The air plasma-treated carbon exhibits a noteworthy capacitance of 1916F/g at 0.05A/g in 2 M KOH electrolyte. long term cyclic stability has been conducted up to 10,000 cycles, the calculated capacitance retention and columbic efficiency is 92.7% and 97.6%. These advancements underscore the potential of utilizing activated carbon from agricultural waste in capacitors and supercapatteries, offering a sustainable solution for energy storage with enhanced performance characteristics.

겨울과 같은 환경에서 곤충은 생존과 번성을 위해 생리학적, 생화학적 및 행동적 메커니즘을 이용하고 있다. 대부분의 곤충은 생리학적 적응가운데 급속내한성(Rapid cold hardiness, RCH) 유기를 통해 기온이 급격히 낮아 지는 외부 환경에 대해 빠르게 적응하고 저온조건에서 생존율을 높인다. 열대거세미나방의 경우 행동적 메커니 즘을 통해 따뜻한 곳을 찾아 장거리 비행을 하며, 생존에 유리한 환경으로 이동한다. 본 연구에서는 열대거세미나 방의 생리적 월동능력과 RCH 능력에 관해 조사하였다. 그 결과, RCH에 의해 혈중 글리세롤의 농도가 증가와 체내빙결점이 하강하는 것을 확인할 수 있었다. 또한, RCH(-10℃, 1h)에 노출된 2령 유충기를 대상으로 4령과 5령 유충기에 단기저온(5℃, 30min)에 노출 시 글리세롤 생합성에 관여하는 유전자(glycerol kinase 1, 2)의 발현이 RCH에 노출되지 않은 대조구와 비교하여 빠르게 발현되었다. 이는, 열대거세미나방의 유전자 수준에서 저온에 대한 단기기억이 존재하는 것을 제시한다.

2017년 7월 15일 서울과 수도권에 집중호우를 발생시킨 깊은 대류운과 강수 발달에 대한 종관 기상 메커니즘 을 규명하고 중국 동부지역으로부터의 PM2.5 에어로졸의 간접효과를 WRF-Chem 실험을 통해 분석하였다. WRF-Chem 모델에 에어로졸과 복사의 피드백, 구름 화학 과정, 습식 세정을 모두 포함한 ARI (Aerosol Radiation Interaction) 실험 과 에어로졸과 복사의 피드백을 제외하고 구름 화학 과정, 습식 세정만을 포함한 ACR (Aerosol Cloud Radiation interaction) 실험 결과의 차이로부터 PM2.5 에어로졸 간접효과를 산출하였다. 2017년 7월 15일 새벽에 황해와 한반도에 서는 동아시아 대륙에서 저기압-북서 태평양의 고기압 분포로 인해 중국 남동 지역과 동중국해로부터 덥고 습한 기류 가 수렴하고 있었다. 이러한 황해의 종관 기상에 의해 발달하는 대류운은 높이 12 km 이상이며 고체 수상체를 형성하 고 있었는데, 이는 주로 대륙 위에서 발달하는 한랭운(많은 빙정을 형성하며 운정고도가 8 km 이상)의 특성을 나타내고 있었다. 특히, WRF-Chem 모델 실험을 통해 중국 동부지역으로부터 확산하는 PM2.5 에어로졸이 구름물 형성에 5.7%, 고체 수상체 형성에 10.4%, 그리고 액체 수상체 형성에 10.8%로 대류운이 한랭운으로 발달하는 데 기여하고 있었다. 본 연구는 황해 위에서 깊은 대류운이 발달하는 과정에 대한 기상적 메커니즘과 더불어 중국 동부지역으로부터 에어로 졸에 의한 간접효과의 영향을 제시하였다.

AA1050/AA6061/AA1050 layered sheet was fabricated by cold roll-bonding process and subsequently T4 and T6 aging-treated. Two commercial AA1050 sheets of 1 mm thickness and one AA6061 sheet of 2 mm thickness were stacked up so that an AA6061 sheet was located between two AA1050 sheets. After surface treatments such as degreasing and wire brushing, they were then roll-bonded to a thickness of 2 mm by cold rolling. The roll-bonded Al sheets were then processed by natural aging (T4) and artificial aging (T6) treatments. The as roll-bonded Al sheets showed a typical deformation structure, where the grains are elongated in the rolling direction. However, after the T4 and T6 aging treatments, the Al sheets had a recrystallized structure consisting of coarse grains in both the AA5052 and AA6061 regions with different grain sizes in each. In addition, the sheets showed an inhomogeneous hardness distribution in the thickness direction, with higher hardness in AA6061 than in AA1050 after the T4 and T6 age treatments. The tensile strength of the T6-treated specimen was higher than that of the T4-treated one. However, the strength-ductility balance was much better in the T4-treated specimen than the T6-treated one. The tensile properties of the Al sheets fabricated in the present study were compared with those in a previous study.

PURPOSES : In this study, heating concrete is developed using heating artificial binder, which is more conductive and less expensive than ordinary Portland cement, and the heating effect is verified through laboratory tests and numerical analysis. METHODS : Based on the test results, the range of heat influence of the Heating concrete is calculated through numerical analysis. As a result of the laboratory test, the temperature rises to 58℃ after 10 minutes when heat generation started at the outdoor temperature of 12℃ and the initial temperature of the concrete specimen of 19.1℃. RESULTS : The heating effect is up to 50 cm in width and 90 cm in height centered on the heating concrete through numerical analysis to analyze the influence range of the Heating concrete based on the laboratory test results. However, when the distance from the heating concrete is greater than about 20 cm, the influence becomes very small, and the rate of temperature decrease drops significantly. CONCLUSIONS : From the test and numerical analysis, it can be used as an eco-friendly heating material suitable for concrete pavements.

Changes in the microstructure and mechanical properties of as-roll-bonded AA6061/AA5052/AA1050 threelayered sheet with increasing annealing temperature were investigated in detail. The commercial AA6061, AA5052 and AA1050 sheets with 2 mm thickness were roll-bonded by multi-pass rolling at ambient temperature. The roll-bonded Al sheets were then annealed for 1 h at various temperatures from 200 to 400 °C. The specimens annealed up to 250 °C showed a typical deformation structure where the grains are elongated in the rolling direction in all regions. However, after annealing at 300 °C, while AA6061 and AA1050 regions still retained the deformation structure, but AA5052 region changed into complete recrystallization. For all the annealed materials, the fraction of high angle grain boundaries was lower than that of low angle grain boundaries. In addition, while the rolling texture of the {110}<112> and {123}<634> components strongly developed in the AA6061 and AA1050 regions, in the AA5052 region the recrystallization texture of the {100}<001> component developed. After annealing at 350 °C the recrystallization texture developed in all regions. The as-rolled material exhibited a relatively high tensile strength of 282 MPa and elongation of 18 %. However, the tensile strength decreased and the elongation increased gradually with the increase in annealing temperature. The changes in mechanical properties with increasing annealing temperature were compared with those of other three-layered Al sheets fabricated in previous studies.

The purpose of this study was to analyze microstructural changes and evaluate the mechanical properties of TWIP steel subjected to variations in heat treatment, in order to identify optimal process conditions for enhancing the performance of TWIP steel. For this purpose, a homogenization heat treatment was conducted at 1,200 °C for 2 h, followed by hot rolling at temperature exceeding 1,100 °C and cold rolling. Annealing heat treatment is achieved using a muffle furnace in the range of 600 °C to 1,000 °C. The microstructure characterization was performed with an optical microscope and X-ray diffraction. Mechanical properties are evaluated using micro Vickers hardness, tensile test, and ECO index (UTS × Elongation). The specimens annealed at 900 °C and 1,000 °C experienced a significant decrease in hardness and strength due to decarburization. Consequently, the decarburization phenomenon is closely related to the heat treatment process and mechanical properties of TWIP steel, and the effect of the microstructure change during annealing heat treatment.

Domestic commercial low- and intermediate-level radioactive waste storage containers are manufactured using 1.2 mm thick cold-rolled steel sheets, and the outer surface is coated with a thin layer of primer of 10~36 μm. However, the outer surface of the primer of the container may be damaged due to physical friction, such as acceleration, resonance, and vibration during transportation. As a result, exposed steel surfaces undergo accelerated corrosion, reducing the overall durability of the container. The integrity of storage containers is directly related to the safety of workers. Therefore, the development of storage containers with enhanced durability is necessary. This paper provides an analysis of mechanical properties related to the durability of WC (tungsten carbide)-based coating materials for developing low- and intermediate-level radioactive waste storage containers. Three different WC-based coating specimens with varied composition ratios were prepared using HVOF (high-velocity oxy-fuel) technique. These different specimens (namely WC-85, WC-73, and WC-66) were uniformly deposited on cold-rolled steel surfaces ensuring a constant thickness of 250 μm. In this work, the mechanical properties of the three different WCbased coaitng materials evaluated from the viewpoints of microstructure, hardness, adheision force between substrate and coating material, and wear resistance. The cross-sectional SEM-EDS (Scanning Electron Microscope-Energy Dispersive X-ray Spectroscopy) images revealed that elements W (tungsten), C (carbon), Ni (nickel), and Cr (chromium) were uniformly distributed within the each coating layers which was approximately 250 μm thick. The average hardness values of HWC-85 and HWC-73 were found to be 1,091 Hv (Vickers Hardness) and 1,083 Hv, respectively, while the HWC-66 exhibited relatively lower hardness value of 883 Hv. This indicates that a higher WC content results in increased hardness. Adhesion force between and substrates and coating materials exceeded 60 MPa for all specimens, however, there were no significant differences observed based on the tungsten carbide content. Furthermore, a taber-type abrasion tester was used for conducting abrasion resistance tests under specific conditions including an H-18 load weight at 1,000 g with rotational speed set at 60 RPM. The abrasion resistance tests were performed under ambient temperatures (RT: 23±2°C) as well as relative humidity levels (RH: 50±10%). Currently, the ongoing abrasion resistance tests will include some results in this study.

This study is in order to the effect of 1-methlycyclopropene (1-MCP) treatment and film package as modified atmosphere packaging (MAP) on the changes in fruit quality factors of 'Daehong' peaches during cold storage. The concentrations of 1-MCP were treated at 1μL·L-1 and 2μL·L-1, and peaches in film package were stored for 28 days in cold storage at 5±1°C and 85±5% RH. The fruits stored carton box were used as a control of MAP, and 1-MCP free fruits were used as the control of both packages. Rate of fresh weight loss during storage was not significantly different between groups with and without 1-MCP treatment, but was higher in the box package than in the MAP. The control group had a higher incidence of both gases with the 1-MCP treatment group showing statistically significantly low. Carbon dioxide in the package was lowered by about 12% compared to the non-treated group, and the ethylene concentration was maintained at 1μL·L-1, showing a significance low compared to other treated groups. As the storage period elapsed, the firmness of 1-MCP and MAP treated fruits remained significant at 5-9% compared to the control group. Regardless of the packaging method Hunter a* values of exocarp and mesocarp were significantly higher in fruit treated with 1-MCP 1μL·L-1 treatment than in the control group, and anthocyanin was significantly higher in the fruit during the storage period, especially high in MAP. In summary, fruits of MAP group with 1-MCP 1μL·L-1 had rate of lower respiration and ethylene production, and little changes in firmness, Hunter a* values of exo-carp and meso-carp, and anthocyanin, which is considered the most suitable method for preserving postharvest quality of the peach cultivar during the storage.