Hot section components of gas turbines are exposed to a high operating temperature environment. To protect these components, thermal barrier coatings (TBC) are applied to their surfaces. Yttria-stabilized zirconia (YSZ), which is widely used as a TBC material, faces limitations at temperatures above 1200 °C. To mitigate these issues, research has focused on adding lanthanide rare earth oxides and tetravalent oxides to prevent the phase-transformation of the monoclinic phase in zirconia. This study investigated the effects of varying TiO2 content in Nd2O3 and Yb2O3 co-doped YSZ composites. Increasing TiO2 content effectively suppressed formation of the monoclinic phase and increased the thermal degradation resistance compared to YSZ in environments over 1200 °C. These findings will aid in developing more thermally stable and efficient TBC materials for application in high-temperature environments.

This study was conducted to secure basic data for developing technologies to reduce the generation of odor substances by investigating the effects of environmental temperature on growth performance and the generation of odor substances from feces in growing pigs. A total of 16 pigs (Landrace × Yorkshire × Duroc, average body weight 56.49±0.47kg) were randomly assigned to two treatments: thermal-neutral (TN) and heat stress (HS) conditions. The experiments were conducted for two weeks, with average temperature-humidity indices of 68.91±0.09 for TN and 85.98±0.08 for HS. The results showed that HS significantly decreased average daily feed intake (ADFI, 33.3%) and average daily gain (ADG, 25.8%) compared with TN (p<0.05). Non-esterified fatty acid in serum was lower (36.2%) in HS compared with TN (p<0.05). However, protein, blood urea nitrogen, cholesterol, triglyceride, glucose, and IgG in serum showed no difference between HS and TN. Phenol (350.0%) and skatole (416.3%) were significantly higher in HS than in TN (p<0.05). The decrease in growth performance is attributed to reduction in ADFI. The increase in phenol and skatole in HS is presumed to be due to the effect of HS on the metabolism of intestinal microbial composition. Digestion rate, intestinal microbial composition, and urine emissions are known to affect odor substances. Further research on the content of odor substances in urine, nutrient digestion rate, and intestinal microbial composition is considered necessary to determine the exact associations.

Compared with the traditional Haber Bosch process, green and pollution-free electrocatalytic nitrogen reduction (NRR) has received considerable attention in the electrocatalysis field in the last decade. To address the issue of its low reactivity as well as the existence of competitive reactions, efficient electrocatalysts are particularly important. In this paper, NiO nanomaterials were synthesized by a simple water bath reaction. The effect of different calcination temperatures on the structure of NiO catalyst and its catalytic activity was studied. Uniform NiO-600 nanoparticles (56 ± 9.3 nm) obtained at 600 ℃ showed the best electrocatalytic NRR activity with an NH3 yield of 12 μg h− 1 mg− 1 and a Faraday efficiency of 5.5% at -0.5V (vs.RHE). The small particle size of the nanoparticles provided more active sites and the oxygen-rich vacancies facilitated the adsorption and activation of N2, which improved the catalytic activity of NiO-600. This study highlights the need for calcination temperature regulation and the huge impact on catalyst structure.

For the regeneration of diesel particulate filters (DPF) using non-thermal plasma (NTP), both cost-effectiveness and regeneration efficiency should be raised. This study compared and contrasted the physicochemical characteristics of carbon black and engine particulate matter (PM). After carbon black was put into the DPF, an experimental setup for the oxidation of PM using NTP was created. The findings showed that carbon black and PM samples had comparable oxidation traits, micronanostructures, and C/O elemental ratios. O3, the main active species in NTP, was susceptible to heat breakdown, and the rate of decomposition of O3 increases with increasing temperature. The removal effectiveness of carbon black first improved and subsequently declined with an increase in the NTP injection flow rate during offline DPF regeneration using NTP at room temperature. A relatively high carbon black removal efficiency of 85.1% was achieved at an NTP injection flow rate of 30 L/min.

Pure SnO2 has proven very difficult to densify. This poor densification can be useful for the fabrication of SnO2 with a porous microstructure, which is used in electronic devices such as gas sensors. Most electronic devices based on SnO2 have a porous microstructure, with a porosity of > 40%. In pure SnO2, a high sintering temperature of approximately 1300°C is required to obtain > 40% porosity. In an attempt to reduce the required sintering temperature, the present study investigated the low-temperature sinterability of a current system. With the addition of TiO2, the compositions of the samples were Sn1-xTixO2-CoO(0.3wt%)-CuO(2wt%) in the range of x ≤ 0.04. Compared to the samples without added TiO2, densification was shown to be improved when the samples were sintered at 950°C. The dominant mass transport mechanism appears to be grain-boundary diffusion during heat treatment at 950°C.

본 연구는 부화 온도가 맹꽁이(Kaloula borealis) 알의 부화 기간에 영향을 미치는 여부를 알아보기 위해 수행되었다. 본 연구에서 맹꽁이 알에서 올챙이가 생긴 것을 기준으로 알 부화 과정을 기록했다. 연구 결과 맹꽁이의 모든 알은 산란 후 48시간 이내에 부화하였으며, 28.1%(±10.8, n=52)가 24시간 이내에, 99.9%(±0.23, n=49)가 산란 후 48시간 이내에 부화했다. 수온의 차이에 따라 맹꽁이 알의 평균 부화율은 유의미한 차이를 나타냈다. 산란 후 15~24시간 사이의 평균 부화율은 24.1(±0.2)°C보다 21.1(±0.2)°C의 수온에서 더 높았다. 본 연구 결과는 비교적 낮은 수온에서 빠른 부화가 되는데 이는 비가 오는 계절에 일시적인 연못이나 웅덩이에 알을 낳는 번식 습성으로 웅덩이가 마르기 전에 빠른 부화가 필요하기 때문으로 추측한다. 본 연구 결과는 멸종위기종인 맹꽁이 알의 최적 부화온도를 이해하는데 도움이 된다.

상추는 수요가 연중 지속됨에 따라 재배면적과 생산량이 증가하고 있는데, 주로 생식으로 이용되며 수확간격 이 짧아 해충 다발생시 약제방제가 어려운 작물이다. 최근 검은무늬밤나방이 약제방제가 소홀한 포장에서 잎을 광포식하여 빠른 시간내에 직접적인 피해를 주고 있다. 본 연구에서는 검은무늬밤나방의 온도별 발육특성을 구명하여 방제를 위한 기초자료로 이용하고자 한다. 검은무늬밤나방은 시설재배 상추에 발생한 유충을 채집하 여 실내 사육 후 항온조건(15, 20, 25, 30℃)에서 발육단계별 발육기간을 조사하였다. 온도가 높아짐에 따라 각 태별 발육기간은 짧아지는 경향이었으며, 유충은 보통 4회 탈피하였다. 25℃에서 알기간은 2.5일, 유충기간 10.0 일, 전용기간 1.0일, 번데기기간 7.0일로 알에서 성충까지의 발육기간은 20.5일 이었다.

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.

The small brown planthopper (SBPH), Laodelphax striatellus, is a major insect pest for the rice plants. SBPH is also a known vector of rice stripe virus (RSV), which causes severe yield losses in rice crops throughout the East Asia. RSV is persistently transmitted by SBPH and can also be transmitted to offspring through transovarial transmission. SBPH is known to migrate from China to the west coast of the Republic of Korea (ROK). The study investigated the impact of temperature on the acquisition and transmission of RSV by SBPH in ROK, which is expected to experience increased migration and emergence of SBPH due to climate change. The results revealed that the acquisition and transmission rates of RSV were higher at 27°C compared to 24°C, with rates of 100% and 78.3%, respectively. However, at 30°C, the acquisition and transmission rates of RSV was decreased. The results suggests that temperature can impact the transmission of RSV by SBPH. To investigate this further, SBPH adults were fed on RSV-infected plants and infection rates were compared across various tissues, including the head, salivary glands, midgut, Malpighian tubules, ovary, and hindgut. Results showed that at 36 hours post-infection, RSV was highly detected in the Malpighian tubules, ovary, and hindgut. At 48 hours post-infection, RSV was also detected in the thorax. These results suggest that the transmission rates of RSV in SBPH increase with temperature between 24-27°C, but decrease at 30°C, indicating that the vectorial capacity of SBPH for RSV decreases above a certain threshold.

This study aimed to identify and analyze the effects of both isothermal heat treatment temperature and residence time on the formation of mesophase in coal tar pitch, especially with respect to its microstructural and crystalline evolution. The formation and growth of mesophase resulted in a decrease in d002 and an increase in Lc, and the degree of such variation was larger when the isothermal heat treatment temperature was higher. In isothermally heat-treated pitch, two distinct domains were observed: less developed crystalline carbon (LDCC) and more developed crystalline carbon (MDCC). When pitch was isothermally heat-treated at 375 °C for 20 h, d002 was 4.015 Å in the LDCC and 3.515 Å in the MDCC. Higher isothermal heat-treatment temperatures accelerated the formation, growth, and coalescence of mesophase. Indeed, in the pitch specimen isothermally heat-treated at 425 °C for 20 h, d002 was 3.809 Å in the LDCC and 3.471 Å in the MDCC. The evolution of mesophase was characterized by pronounced inflection points in d002 curves. It was found that the emergence of these inflection points coincided with pronounced changes in the microstructure of mesophase. This finding confirmed the relationship between inflection points in d002 and the microstructure of mesophase.

For the Floating Photovoltaic development project, economic analysis is conducted by predicting the amount of power generation in consideration of climate factors. Among the climate factors, the outside temperature increases the temperature of the module. As a result, the efficiency of the module is reduced. Due to global warming, the outside temperature is rising every year, when estimating the amount of power generation over the next 20 years, a more accurate prediction will be possible only when considering the temperature rise.

This study aimed to investigate the effects of amino acid complex additives, such as protected vitamin C (VC) or detoxified sulfur (DS), on the growth and metabolism of Hanwoo cattle under high-temperature conditions. Accordingly, farms in Temperature-Humidity Index (THI) regions ranging from 78 to 89 for over 100 days were selected. The experimental groups were control, T1 (lysine + methionine + VC, 50 g/head/day), and T2 (lysine + methionine + DS, 50 g/head/day) with 70, 77, and 71 animals each. The range of the THI for 115 days was 78-89, and this occurred in most of the experiment days. The results showed that there was no significant difference in rectal temperature among the groups. The body weight increased to 786.4 and 809.0kg in the T1 and T2 groups, respectively, compared to the control group (p<0.05). Linoleic acid showed a high result of 2.01% in the T1 group compared to the control group (p<0.05). Unsaturated fatty acids were higher at 55.70 and 56.54% in the T1 and T2 groups, respectively, compared to the control group (p<0.05), and the omega 6/3 ratio was reduced to 20.10% (p<0.05). These findings indicate that T1 has a positive impact on growth, meat quality, and fatty acid composition compared to the control group. In conclusion, amino acid complex with VC improved the body weight of Hanwoo steers and the unsaturated fatty acids and essential amino acids of their meat; however, further research is needed to clarify this impact on carcass performance.

The effects of exogenous sodium nitroprusside (SNP, nitric oxide donor) on the growth, yield, photosynthetic characteristics, and antioxidant enzyme activity of kimchi cabbage (Brassica rapa L. subsp. pekinensis (Lour.) Hanelt) was studied under the low temperature conditions. Kimchi cabbages were treated with SNP of three concentrations (7.5, 15, 30 mg·L-1) for three times at four-day intervals and exposed to low temperature (16/7°C) stress for seven days. SNP treatment induced increases of net photosynthetic rate (Pn), stomatal conductance (Gs), intracellular CO2 concentration (Ci) and transpiration rate (Tr) under the stress condition with the highest level after the third treatment. The contents of malondialdehyde (MDA) and H2O2 were significantly lower in the treatment of SNP compared to the non-treated control. The activity of ascorbate peroxidase (APX), catalase (CAT), peroxidase (POD) and superoxide dismutase (SOD), increased in treated plants by up to 38, 187, 24 and 175%, respectively compared to the non-treated control. SNP-treated and untreated plants had similar growth characteristics. Compared to the control group, SNP-treatment increased fresh weight and leaf area by 5%. Overall, our findings suggest that the application of sodium nitroprusside to the leaves contributes to reducing physiological damage and enhancing the activities of antioxidant enzymes, thereby improving low temperature stress tolerance in kimchi cabbage.

Drosophila suzukii (Diptera, Drosophilidae) can damage thin-skinned fruits (plums, cherries, peaches, blueberries, and strawberries) by laying eggs inside the fruit. In this study, a basic experiment was conducted to investigate the preference of D. suzukii to export table grape varieties. Four varieties of grapes (Kyoho grape, Shine muscat, Campbell grape, and Black sapphire) were placed in a cage containing more than 2,500 number of D. suzukii adults for 6, 8, 10, 12, and 24 hours and the egg-laying in grape has been induced. After 2 weeks, the number of pupae that emerged was counted. As a result, the largest number of pupae was generated in Kyoho grape among the four types of grapes, indicating that D. suzukii prefers to lay egg in Kyoho grape. Through this experiment, it was determined that 6 h was the appropriate inoculation time, and then an inoculation experiment was conducted on Kyoho grape. The total weight of the Kyoho grape used in the experiment was 36.119 kg, and a total of 2594 pupae were generated. The average number of D. suzukii per cluster was about 50. All stages of D. suzukii treated with low temperature(1℃) for 10 days were completely controlled.

Feltiella acarisuga(Vallot) is a common gall midge that feeds on many species of spider mites. The effect of temperature and humidity on the development of F. acarisuga female were determined using eggs of the twos potted spider mite, Tetranychus urticae(Koch), as prey under laboratory condition (27.9±0.5℃, 90% RH, and 14:10 [L:D] h). F. acarisuga female laid the most eggs on the 5th day after mating, and the acumulative fecundity reached it speak on the 13th day. The sex ratio of F. acarisuga was 6:4, male to female. The average number of eggs per day during life was 2.7 but during the egg-laying period was 3.1. The female’s lifespan was about 3.5 days longer than that of the male in the adult stage but 6.2 days longer including the egg and larval period. The temperature did not affect the female survival and fecundity, but as humidity was lowered, the female’s survival period washortened and fecundity decreased. When using F. acarisuga as natural enemies, the optimal temperature rage was 20 to 30℃ and the relative humidity was 80 to 95%.

Cnidium officinale M. is an important crop that is widely used as a raw material for health functional foods. However, it is experiencing cultivation difficulties due to climate change and abnormally high temperatures. In response to this problem, the characteristics and main causes of the high-temperature damage occurring in C. officinale M. cultivation fields were analyzed. A survey of five farmhouse fields in Jecheon and Bonghwa, major C. officinale M. cultivation areas in Korea in 2018, indicated that about 5% to 37% of the cultivation fields in Jecheon and 5% to 15% of the fields in Bonghwa died from wilting. The high-temperature damage of the C. officinale M. fields is divided into two categories: upper leaves drying due to solar radiation and temperature, and lower leaves dying serially to the radiant heat of the vinyl mulch. Damage caused by radiant heat was typically greater. This is due to the greenhouse effect that occurs in the small space between the black vinyl mulching and the soil. The heat radiated to the surface of the ridge creating an environmental condition that greatly exceeded the atmospheric temperature especially on hot days. As a result, short plants with underground parts, such as C. officinale M., can suffer more high-temperature damage than other plants, so it is considered that it is necessary to develop related technologies such as mulching materials that can reduce pavement temperature in the future.

In this study, we evaluated the effects of acid leaching on the properties of Cr powder synthesized using self-propagating high-temperature synthesis (SHS). Cr powder was synthesized from a mixture of Cr2O3 and magnesium (Mg) powders using the SHS Process, and the byproducts after the reaction were removed using acid leaching. The properties of the recovered Cr powder were analyzed via X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), particle size analysis (PSA), and oxygen content analysis. The results show that perfect selective leaching of Cr is challenging because of various factors such as incomplete reaction, reaction kinetics, the presence of impurities, and incompatibility between the acid and metal mixture. Therefore, this study provides essential information on the properties under acidic conditions during the production of high-quality Cr powder using a self-propagating high-temperature synthesis method.

Cyanobacteria Pseudanabaena strains are known to produce 2-MIB (odorous material) in freshwater systems, thereby causing problems in water use. However, their physiological responses to environmental factors in relation with 2-MIB production is not well explored. This study was conducted to evaluate the effect of temperature on the growth and 2-MIB production of Pseudanabaena redekei. The experimental cyanobacteria strains were separated from the Uiam Reservoir (North Han River) and cultured in the BG-11 medium. Temperature was set to 10, 15, 20, 25, and 30℃ for the experiment, in the reflection of the seasonal water temperature variation in situ. For each temperature treatment, cyanobacterial biomass (Chl-a) and 2-MIB concentration (intra-cellular and extra-cellular fractions) were measured every 2 days for 18 days. Both maximal growth and total 2-MIB production of P. redekei appeared at 30℃. While intra-cellular 2-MIB contents were similar (26~29 ng L-1) regardless of treated temperatures, extra-cellular 2-MIB concentration was higher only in high temperature conditions (25~30℃), indicating that the extents of 2-MIB biosynthesis and release by P. redekei vary with temperature. The 2-MIB productivity of P. redekei was much higher in low-temperature conditions (10~15℃) than high temperature conditions (25~30℃). This study demonstrated that temperature was a critical factor contributing to 2-MIB biosynthesis and its release in cell growth (r=0.605, p<0.01). These results are important to understand the dynamics of 2-MIB in the field and thereby provide basic information for managing odorous material in drinking water resources.

본 연구는 국내 산림생명자원 중 광나무의 대량생산을 위한 기초연구로, Priming 처리에 따른 발아 효율성 및 유묘 생육특성에 미치는 영향을 구명하고자 수행하였다. 종자 Priming처리는 대조구, GA3 (10, 100, 200 ㎎·L-1), Ca (NO3)2 (50, 100, 200 mM), KNO3 (50, 100, 200 mM)를 24시간 처리하여 발아특성을 분석하였고, 순화재배에 따른 생육특성 및 활착률을 조사하여 수확량을 비교·분석하였다. 발아특성은 25℃·KNO3 100 mM에서 발아율이 유의적으로(p<0.001) 높았으며, 평균발아일수는 10.3~18.1일로 15℃에서 대체적으로 빠른 발아일수를 나타냈다(p<0.001). 발아속도 및 발아균일지수 또한 25℃·KNO3 100 mM에서 유의적으로 높은 값을 보였다(p<0.001). 생육특성의 경우 2 5℃·KNO3 100 mM 처리에서 유근 길이(5.1±2.4 ㎝), 초장(5.7±0.7 ㎝), 근장(16.6±2.0 ㎝), 건중량(0.079 g)이 유의적으로 가장 높게 나타났다 (p<0.001). 유묘활력지수 또한 25℃·KNO3 100 mM 처리에서 1418.3으로 높았으며, 가장 높은 수확량(16.8 g/㎡)을 나타냈다. 결과적으로 25℃, KNO3 100 mM 처리 시 실내발아에서 발아효율성을 높일 수 있었으며, 순화재배 시 우수한 유묘 생육을 보여 수확량을 증진시킬 수 있었다.

수경 재배한 멜론의 생육과 수확 후 모의유통 시 품질 차이를 검토하였다. ‘루비볼춘추계’의 수경재배 된 멜론을 이용하여 저장 온도를 2℃와 5℃, 10℃, 20℃하여 모의유통 시 특성과 가용성고형물(SSC), 경도, 생체중 변화, 외관 등의 변화를 조사하였다. 멜론을 상온으로 유통하는 조건 하에서 저온저장에 따른 과실 특성을 본 연구에서 확인하였다. 멜론 저장 시 가용성고형물, 경도, 생체중, 외관이 저장온도에 따라 차이를 보였다. 가용성고형물은 멜론을 저온(2~5℃)에서 저장하여 모의유통 된 것이 상온(20℃)에서 다른 온도처리보다 높은 수준인 것으로 나타났다. 외관과 경도는 모의유통 중 저장 온도에 따른 영향이 지속적이지는 못하였지만 유통초기 저온(2~10℃) 저장이 외관 지수 및 경도 수치가 높은 경향이었다. 저장 온도에 따른 영향이 모의유통 시 계속 효과를 유지하지 못하여 국내 유통 시 이를 고려하여야 할 것이다. 본 연구 결과, 저장 온도에 따른 모의유통 중에 미치는 영향은 저장 직후 짧은 단기간에만 효과를 유지하여, 국내 유통 하에서 저장할 경우에는 바로 소비할 수 있도록 유도해야 할 것으로 생각된다.