This study analyzes the impact of climate change on the performance of continuous reinforced concrete pavement (CRCP) and proposes a method to improve the existing KPRP–CRCP design procedure. Our analysis of monthly mean temperature data from the Seoul Meteorological Station revealed a general increase in temperature from 2001 to 2034, with a more significant increase observed during summer and winter. The existing KPRP–CRCP design method uses the drop temperature (DT) as a key variable. Notably, the increasing monthly mean temperatures owing to climate change tend to decrease the DT that in turn lowers the maximum stress on the pavement slab. This leads to a significant problem: if the traditional design method based on outdated data is used, the predicted number of punchouts will be lower than expected. This can result in an over-reduction in the reinforcement ratio and slab thickness, leading to premature failure and increased maintenance costs. To solve this issue, we introduced a predictive model for the final setting temperature that accounts for monthly and regional characteristics. Applying this model showed that as the temperature increased, the DT and maximum stress proportionally increased. This provided a more realistic prediction of the number of punchouts and addressed the flaws of the existing design method. Furthermore, our analysis of punchout counts based on the construction start month using this predictive model revealed that punchouts were more frequent in summer (July–August) and less frequent in winter (January–February). Based on this, we determined that the optimal seasons for placing continuous reinforced concrete pavements were spring (March–June) and fall (September–November). In situations where the actual construction start month was unknown, we recommended using a conservative design approach based on the design in August, when punchouts were most likely to occur.

This study was conducted to elucidate the effects of feeding betaine or monosodium glutamate on the growth and carcass performance of Hanwoo steers according to the fattening stage under high-temperature stress. Farms in an area where THI was 78 or higher for more than 100 days were selected, and 30 head in the early fattening stage (14-15 months of age), 30 head in the mid-fattening stage (16-18 months of age), and 30 head in the late fattening stage (24-25 months of age) were tested, and 10 head were assigned to each treatment group. The experimental group was divided into control, T1 with 96% of the amino acid compound additive and 4% betaine, and T2 with the amino acid complex additive and 4% monosodium glutamate. 50 g per head were fed every morning for a total of 5 months from May 1, 2022 to September 30. In this study, there was no effect of betaine and monosodium glutamate on the growth and rectal temperature of Hanwoo steers at each fattening stage, but monosodium glutamate had a positive effect on the increase in rib eye area and decrease in back fat thickness in steers in the late fattening stage (P<0.05). Therefore, the results of this study indicate that monosodium glutamate did not have a direct effect on the growth of fattening Hanwoo steers, but it is thought to have a positive effect on the rib eye area and back fat thickness through protein metabolism and muscle development.

본 연구에서는 저온 스트레스에서 살리실산(SA, salicylic acid)의 경엽처리가 배추의 광합성, 생리활성 및 생육에 미치는 영향을 구명하고자 하였다. SA을 각각 0.25, 0.5 및 1mM 농도로 주당 100mL을 4일 간격으로 3회 엽면 살포하였고, 7일간 저온 스트레스를 처리하였다. SA 처리 시 광합성 속도, 기공전도도, 세포 내 CO2 농도 및 증산 속도는 무처리 대비 증 가하였고, 2회 처리 후 가장 높았다. MDA 함량은 무처리 대 비 유의한 차이를 보이며 감소하였다. APX, CAT, POD 및 SOD 활성은 무처리 대비 현저하게 증가하였으며, 각각 최대 62, 81, 55 및 26% 증가하였다. 배추의 생육 특성은 무처리와 유의한 차이를 보이지 않았으나, 수량 지수는 2－6% 정도 증 가하였다. 따라서 SA의 경엽처리는 배추의 생육, 광합성 특성 및 항산화 효소 활성을 증대시켜 저온 스트레스를 완화 하였 고, 적정농도는 0.5－1mM이라 판단된다.

This study was performed to investigate immune changes by comparing the proportion and function of immune cells in the blood under high-temperature period and convalescence temperature period in Holstein dairy cows. The experiment was conducted using Holstein dairy cows of five animals per group (60 ± 20 months old, 175 ± 78 non-day) from the National Institute of Animal Science at high-temperature period (THI: 76 ± 1.2) and convalescence temperature period (THI: 66 ± 1.3). Complete blood count results showed no change in the number of immune cells between groups. In the analysis using Flow Cytometry of PBMCs, no significant differences were observed among B cells, Helper T cells, cytotoxic T cells, and γδ T cells between groups. However, there was an increase in Th17 cells producing IL-17a, while Th1 cells decreased during the convalescence temperature period. The results of gene expression analysis using qRT-PCR in PBMCs revealed an increase in IL-10 during the convalescence temperature period, while a decrease in HSP70 and HSP90 was observed. In conclusion, the increased expression of IL-10 and the decrease in HSP expression suggest the possibility of a weak recovery from heat stress. However, the lack of observed changes in B cells, T cells, and other immune cells indicates incomplete recovery from heat stress during the convalescence temperature period.

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.

Radiant tubes heat exchangers are critical components that facilitate the heat transfer process to steel in an annealing furnace, and it addresses several engineering problems, such as thermal stress and mechanical failure due to long-term thermal cycling, which can significantly affect the longevity of the tubes and maintenance requirements. In this study, we used commercial software (ANSYS) to simulate the thermal stress and deformation of radiant tubes subjected to extreme thermal conditions and pressure loads. We evaluated both thermally induced deformation and creep deformation, which is a time-dependent deformation under constant stress over the long term. The results showed that uneven temperature conditions and pressure loads lead to significant deformation and potential failures. To mitigate these engineering challenges, we also tested several designs that include supporting brackets. This study provides valuable insights for designing radiant tube heat exchangers in annealing furnaces to extend their lifespan and ensure system safety.

살리실산은 식물의 생장 및 발달, 항산화 방어기작, 광합성 작용 그리고 생물적 및 비생물적 스트레스 조건에서 다양한 생리적 기능을 조절하는 물질로 알려져 있다. 본 연구에서는 고온･건조 스트레스 조건에서 살리실산 경엽처리가 고추의 생육, 광합성 특성 및 항산화효소 활성에 미치는 영향을 구명 하고자 하였다. 광합성 특성 측정결과 광합성 속도, 기공전도 도 및 증산 속도가 증가하였고, 3회차 처리에서 가장 높았다. 세포내 MDA와 H2O2 함량은 살리실산 3회차 처리에서 현저 하게 감소하는 경향을 보였다. APX, CAT, POD 및 SOD 활 성이 현저하게 증가하였으며, 무처리 대비 최대 247, 318, 55 및 54% 증가하였다. 고추의 생육 특성은 무처리구와 유의한 차이를 보이지 않았으나, 상품 수량은 15% 정도 증가하였다. 이러한 결과들을 종합해 볼 때, 살리실산의 경엽처리는 고추 의 광합성 특성과 항산화효소 활성을 증진시켜 고온･건조 스트 레스에 의한 피해 경감에 긍정적 효과를 유발함을 확인하였다

In this analysis, the analytical model was verified through the normal mode analysis of the piston for the 2.9 liter IDI (indirect injection) engine. Heat transfer analysis was carried out by selecting two cases of applied temperature using the validated model. The first case was a condition of 350℃ on the piston upper surface and 100℃ on the piston body and inner wall. In the second case, the conditions were set to give a temperature of 400℃ on the upper surface of the piston and 100℃ on the piston body and the inner wall. In addition, the temperature distribution due to heat transfer was obtained for the pistons with boundary conditions of two cases, and then the thermal stress distribution due to thermal expansion was obtained using the input. Using this analysis result, the thermal stress caused by thermal expansion due to the thermal conduction of the piston is examined and used as the basic data for design.

본 연구는 적외선 열 영상 장치를 이용하여 2년생 ‘유미’ 복숭아나무의 토양수분 수준에 따른 엽온 및 CWSI를 분석하여 수분스트레스 측정 가능성을 검토하였다. 엽온은 대기온도와 유사한 일변화를 보이며 낮 시간대에는 대기온도보다 높은 양상을 보였다. 엽온은 전일(24시간) 기준으로 대기온도(r2 = 0.95), 일사량(r2 = 0.74), 상대습도(r2 = -0.88)와 모두 높은 상관계수를 나타났다. 또한 토양수분장력은 낮 시간대(11~16시)에 엽온(r2 = -0.57), 엽-대기온도차(r2 = -0.71), CWSI(r2 = -0.72)와 높은 부의상관을 나타냈다. CWSI와 엽온, 엽-대기온도차의 상관계수는 24시간 기준으로 매우 높았고(r2 = 0.90, r2 = 0.92), CWSI와 토양수분장력의 상관분석에서 24시간 기준으로는 상관관계가 낮았으나(r2 = -0.27), 낮 시간대(11~16시)에는 상관관계가 매우 높았다(r2 = -0.72). CWSI (y)와 토양수분장력(x)의 상관관계 결정계수(r2)는 11~12시간대에 가장 높았으며(r2 = 0.68), 이때 회귀식은 y = -0.0087x + 0.14로 조사되었다. 일반적인 토양수분스트레스 시점인 -50 kPa에 해당되는 CWSI는 0.575로 계산된다. 따라서 적외선 열 영상 장치를 이용한 엽온 및 CWSI는 토양수분장력에 대해 높은 상관계수를 나타낸 것으로 보아 복숭아나무의 수분스트레스 진단에 유용하게 활용할 수 있을 것으로 예상된다.

Biogeochemical processes play an important role in ocean environments and can affect the entire Earth’s climate system. Using an ocean-biogeochemistry model (NEMO-TOPAZ), we investigated the effects of changes in albedo and wind stress caused by phytoplankton in the equatorial Pacific. The simulated ocean temperature showed a slight decrease when the solar reflectance of the regions where phytoplankton were present increased. Phytoplankton also decreased the El Niño-Southern Oscillation (ENSO) amplitude by decreasing the influence of trade winds due to their biological enhancement of upper-ocean turbulent viscosity. Consequently, the cold sea surface temperature bias in the equatorial Pacific and overestimation of the ENSO amplitude were slightly reduced in our model simulations. Further sensitivity tests suggested the necessity of improving the phytoplankton-related equation and optimal coefficients. Our results highlight the effects of altered albedo and wind stress due to phytoplankton on the climate system.

수온의 변화는 어류의 거의 모든 생리학적 부분에 영향을 미친다. 기후 변화로 인한 수온의 상 승은 어류에게 물리적 피해를 줄 수 있다. 이 연구는 최적의 수온(15°C)보다 높은 수온(20°C)에 서의 대서양 연어의 건강상태를 평가하기 위해 수행하였다. 간 조직은 열 적응에 중요한 대사 기능을 발휘하기에 본 연구에 간 조직을 사용하였다. 생체지표유전자의 개발을 위한 분석 방법 으로는 NGS RNAseq 방법을 사용하였고, 생체지표유전자의 발현 양상을 관찰하기 위한 분석 방 법으로는 RT-qPCR을 사용하였다. NGS RNAseq 분석을 통해 1,366개의 차별적 발현 유전자를 확인하였으며, 그 중에서 880개의 증가하는 유전자와 486개의 감소하는 유전자를 확인하였다. 생체지표유전자로는 heat shock protein 90 alpha (Hsp90α), heat shock protein 90 beta (Hsp90β) 및 cytochrome P450 1A (CYP1A)을 선정하였는데 이들 유전자는 NGS RNAseq 분석에서 수온의 변화에 민감하게 반응하는 유전자들이었다. 이들 유전자의 RT-qPCR을 통한 발현 양상은 NGS RNAseq 분석과 유사하게 나타났다. 이 연구의 결과는 다른 어종에도 적용할 수 있으며, 산업 적으로도 유용하다고 생각된다.

Environmental stresses caused by climate change, such as high temperature, drought and salinity severely impact plant growth and productivity. Among these factors, high temperature stress will become more severe during summer. In this study, we examined physiological and molecular responses of maize plants to high temperature stress during summer. Highest level of H2O2 was observed in maize leaves collected July 26 compared with June 25 and July 12. Results indicated that high temperature stress triggers production of reactive oxygen species (ROS) in maize leaves. In addition, photosynthetic efficiency (Fv/Fm) sharply decreased in leaves with increasing air temperatures during the day in the field. RT-PCR analysis of maize plants exposed to high temperatures of during the day in field revealed increased accumulation of mitochondrial and chloroplastic small heat shock protein (HSP) transcripts. Results demonstrate that Fv/Fm values and organelle-localized small HSP gene could be used as physiological and molecular indicators of plants impacted by environmental stresses.

기후 변화로 인한 수온의 상승은 어류 서식지에 영향을 미친다. 수온의 변화는 어류 생리 거의 모든 부분에 영향을 미치는 것으로 알려져 있다. 기후 변화에 따른 수온의 상승은 산소 용해도의 감소 및 산소 운반 헤모글로빈의 결합 능 력의 감소로 인해 저산소증을 초래할 수 있다. 본 연구는 대서양 연어 (Salmo salar) 치어 성장의 최적수온 (15°C)보다 고 수온 (20°C)에 사육 시, 대서양 연어 치어의 건강상태를 평가 하기 위해 수행되었다. 평가 방법은 NGS RNAseq 분석방법을 이용하여 생체지표유전자를 개발하고, RT-qPCR 분석을 이용하여 생체지표유전자의 발현양상을 조사하는 것이다. 개발한 생체지표유전자로는 interferon alpha-inducible protein 27-like protein 2A transcript variant X3, protein L-Myc- 1b-like, placenta growth factor-like transcript variant X1, fibroblast growth factor receptor-like 1 transcript variant X1, transferrin, intelectin, thioredoxin-like, c-type lectin lectoxin-Thr1- like, ladderlectin-like 및 calponin-1 등이다. 선택된 생체지표 유전자는 NGS RNAseq 분석을 통해 수온변화에 민감하게 발현한 유전자들이며, RT-qPCR 분석을 통한 이들 유전자의 발현 양상은 NGS RNAseq 분석을 통한 발현 양상과 매우 유사하게 나타났다.

Physiological responses and activities of antioxidative enzymes were investigated in pepper(Capsicum annuum) seedlings subjected to low temperature stress. The seedlings were exposed to 7℃, 11℃, or 15℃ for 4 h during the early seedling stage of pepper plants. The results showed that plant height and chlorophyll content were unaffected by the treatments. Polyphenol content in seedlings exposed to 7℃ was higher than that at 11℃ and 15℃ for 2 h. After 3 h of treatment, the flavonoid content was higher in pepper seedlings exposed to 7℃ than 11℃ and 15℃, which was slightly higher than that detected in the control. The H2O2 content increased remarkably with increasing exposure time to low temperature(i.e., 7℃) as compared to that at 11℃ and 15℃. The levels of antioxidant enzymes superoxide dismutase(SOD), catalase(CAT), ascorbate peroxidase(APX), and peroxidase(POD) fluctuated. These results provide basic information that can be utilized to maintain efficient temperature in greenhouses for sustainable growth of pepper under severe low temperature conditions.