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 This leads to a significant problem: if the traditional design method based on outdated data is used, the predicted number of punchouts will be lower than expected.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.

Nannochloropsis oceanica has been recognized as a valuable source of eicosapentaenoic acid (EPA) for nutraceutical applications. In this study, the effects of temperature on the growth and fatty acid production of N. oceanica were investigated to determine the optimal conditions for maximizing both growth and EPA production. The growth responses of N. oceanica exhibited a wide temperature range of 5-30°C, with the maximum cell density at 25°C (35.9×105 cells mL-1). Biomass production, as measured by dry weight in N. oceanica culture, was the highest at 20°C (86.2 mg L-1). In N. oceanica cultures exposed to relatively low temperatures (5-10°C), cells did not grow significantly; however, the proportion of polyunsaturated fatty acids including EPA (22.3, 26.0% of total fatty acid), was significantly high. These results indicate that the optimal temperature conditions for promoting growth and EPA accumulation of N. oceanica are different. Based on these results, a temperature-dependent two-stage cultivation strategy was proposed to optimize both biomass and EPA production in N. oceanica cultures, which included an initial phase at 20°C to achieve high biomass, followed by a second phase at 5-10°C to maximize EPA accumulation.

The Pyrosim fire simulation program was used to investigate changes in operating time as a function of the attachment height of a fixed-temperature detector. Operating times were analyzed for detector heights ranging from 4 m to 7.5 m, in 0.5 m increments, within a 30 m2 space. The fire source was modeled as a wooden pallet 1.22 m in height, and a Type 1 fixed-temperature detector with an activation temperature of 67.9℃ was used. The simulation results showed that operating time increased progressively with detector height, rising from 155.7 seconds at 4m to 206.3 seconds at 7.5 m a maximum delay of 50.6 seconds. Notably, larger increases were observed in the 4 m ~ 4.5 m and 6 m ~ 6.5 m ranges 14.9 and 11.5 seconds, respectively than those observed in other intervals. This suggests that critical height ranges should be considered when establishing detector installation standards. This study found that current design standards may not ensure adequate detection performance in high-ceilinged structures. In warehouses and industrial facilities with ceilings of 6m or higher, such delays in detector activation could hinder early detection, indicating a need for improvements

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.

케이퍼는 생선 요리에서 악취를 제거하고 맛을 향상시 키거나 균의 성장을 억제하기 위해서 사용된다. 본 연구 에서는 대표적인 히스티딘 탈탄산균인 Morganella morganii 에 대한 케이퍼의 항균 효과를 broth와 수비드 고등어에 적용하여 분석하였다. broth에서 M. morganii의 1차 및 2 차 생장 예측 모델을 개발하고 수비드 고등어에서 broth 생장 예측모델의 적용가능성을 평가하였다. 케이퍼의 항 균 효과를 향상하기 위해 broth에서 건조 케이퍼를 통째로 사용한 것과 분쇄하여 가루로 사용한 것의 항균 효과 를 비교하였다. 또한 고등어에 2% 소금과 10% 가루 케이 퍼의 단독 및 병행 처리 후 수비드 조리법으로 조리 후 M. morganii를 인위적으로 오염시켜 9oC와 25oC에서 저장 하며 2% 소금과 10% 가루 케이퍼의 단독 및 병행 처리 에 대한 항균 효과를 비교하였다. 그 결과, broth에서 구 축된 9oC에서의 최대 증식 속도를 제외한 2차 생장 모델 은 수비드 고등어에서 M. morganii의 성장을 예측하기에 적합한 것으로 나타났다. 또한, 가루 케이퍼가 통 케이퍼 보다 모든 농도와 온도에서 M. morganii에 대한 더 효과 적인 항균 활성을 보였다. broth에서 8oC 이하의 온도에서 는 M. morganii의 성장이 관찰되지 않았으며, 가루 케이 퍼의 최소 저해 농도는 9oC에서 7%, 15oC에서 8%, 25oC 에서는 11%로 나타났다. 수비드 고등어에 2% 소금과 10% 가루 케이퍼를 단독으로 사용했을 때보다 병용 처리했을 때 항균효과가 우수하였으며 특히 9oC에서는 M. morganii 의 성장을 완전히 저지하였다. 그러나 25oC에서는 소금 또 는 가루 페이퍼를 단독으로 처리한 것보다 병용 처리했을 때 M. morganii의 성장을 효과적으로 저해하였으나 9oC에 서처럼 완전히 저지하지는 못하였다. 본 연구를 통해 전 투식량으로 고등어의 수비드 조리에서 케이퍼의 특성이 맛을 향상시키고 실온 유통 제품의 저장성을 연장할 수 있는 천연 보존료로써의 가능성을 확인하였다.

This study investigated the vertical displacement behavior caused by differential drying shrinkage in jointed concrete pavements. This study proposed a method to convert this behavior into an equivalent linear temperature difference for structural analysis. Controlled experiments were conducted under varying humidity and airflow conditions to simulate pavement environments. The test results showed that a lower relative humidity and added airflow significantly increased the vertical displacement, particularly at the slab edges. A 3D finite element model using ABAQUS was developed to analyze the behavior and derive the equivalent linear temperature difference that increased with curing age and varied notably with environmental conditions. These findings highlighted the impact of early-age environmental factors on the shrinkage behavior and suggested that the proposed method offered a practical approach for predicting deformation without repeated physical testing.

본 연구는 전국에서 일조시간이 가장 짧은 제주 동부지역의 저온기에 토마토 수경재배 온실의 광량, 습공기 및 근권 온도 특성을 분석하여 저온기의 저일조 조건에서 안정적인 과채류 생산을 위한 방안을 제언하고자 수행하였다. 본 실험은 제주 시 구좌읍 김녕리 PO 필름 단동형 복합환경제어 온실에서 2022년 10월 30일－2023년 1월 31일, 2024년 11월－2025년 1월까지 2회 실시하였다. 온실 내부에 100W·m-2 이상의 광량 이 도달하는 시간은 2022－2023년의 경우 11월(9시, 114W)> 12월(10시, 110W)> 1월(11시, 104W) 순으로 1월에 11시로 가장 늦었으며, 2024－2025년의 경우 11월(10시, 107W), 12월(10시, 90W), 1월(10시, 104W)이 유사하였다. 일평균 누적광량은 850J·cm-2·day-1 수준 이상으로 측정된 날수가 2022년 11월, 12월과 2023년 1월에 각각 12, 6, 9일이었고, 2024년에는 각각 12, 9, 13일로 심각한 저일조 환경임을 알 수 있었다. 본 연구에서 2023년과 2025년 1월의 VPD 범위는 각 각 5.4－8.8mbar, 5.7－9.8mba로 적정 수준으로 유지되었으 며 증산율은 VPD가 2.5배 낮아짐에 따라 Tr 값이 2배 감소하 였다. 배지 온도는 2023년 1월에 일출 후 시간당 0.2－ 0.6℃씩 증가하여 16℃로 가장 높았다. 온실 내·외부 CO2 농 도차(Ci-Co)는 CO2 시비를 하지 않았을 경우 맑은날은 － 84μmol·mol-1(10시), 흐린 날도 0.2μmol·mol-1(14시) 수준 을 보였다. 본 연구를 종합하여 볼 때, 저온기의 저일조 환경에 서 광량 부족으로 인한 낮은 근권 온도와 CO2 농도가 작물의 광합성과 생장에 제한 요인이 될 수 있음을 시사하고 이를 극 복하기 위한 기술적 대안이 필요하다고 판단된다.

저온기 엽채류 생산시 저온, 저광 등으로 인해 생육 저하 및 수량 감소가 발생한다. 저온기 근권부 가온을 통해 지상부 저 온 스트레스를 경감하고 생육 및 수량을 개선할 수 있다. 최근 루꼴라, 고수, 바질, 공심채 등 향신채소의 국내 수요가 증가하 면서, 연중 생산의 필요성이 증가하고 있다. 본 연구에서는 양 액 가온을 통한 근권부 온도 제어 효과와 지상부 생육 및 수량 에 미치는 영향을 구명하고자 수행하였다. 저온기 경남 함안 에 위치한 유리 온실에서 실험을 실시하였으며, 루꼴라, 고수, 바질, 공심채를 분무경베드에 정식하여 무처리 대조구와 양 액 가온 설정온도별 처리구(NSH20, NSH25, NSH30)를 설 정하였다. 양액 조성은 PBG 엽채류 조성을 따랐으며 재배기 간 동안 폐기 없이 표준 양액(EC 1.8, pH 5.5)으로 보충하여 사용하였다. 양액의 특성 및 이온 농도는 약 3일 간격으로 분 석하였으며, 작물의 생육 및 수확 조사는 각각 정식후 2주와 4 주차에 수행하였다. 재배 기간 동안 온실 내부의 일일 최저, 평균, 최고 온도는 각각 13.75℃, 18.66℃, 30.08℃였으며, 재 배 기간 중 온실 내 최저 온도는 9.97℃였다. 대조구의 근권부 온도는 최저 13.35℃, 평균 17.17℃로 근권부 저온으로 인한 뿌리 생육 저하, 지상부 생육 감소를 유발할 수 있다. 설정 온 도별 가온 양액을 공급한 경우 근권부 평균 온도는 NSH30는 24.61℃, NSH25는 21.41℃, NSH20는 18.62℃였다. 호냉 성 작목인 루꼴라와 고수는 근권부 온도에 따른 생육 및 수량 변화가 확인되지 않았다. 반면 호온성 작목인 바질과 공심채 는 양액 가온을 통한 근권부 온도 제어시 생육 및 수량 개선이 확인되었다. 바질은 NSH25와 NSH30 처리구에서 유사한 생 육 및 수량 개선 효과가 확인되었으며, 에너지 효율성을 고려 했을 때 양액 가온 온도를 25℃로 설정하는 것이 더 경제적인 근권부 온도 관리 방안이 될 것으로 생각된다. 반면 공심채는 NSH30에서 수량이 대조구 대비 107%, NSH25 대비 60% 증 가한 것으로 보아 양액 가온 설정 온도를 높게 유지하는 것이 적합할 것으로 생각된다.

This study incorporates the formation of carbon quantum dots (CQDs) via a hydrothermal approach, recording the first-time use of castor leaves as a natural precursor. The used precursor offers various benefits including novelty, abundance, elemental composition, and biocompatibility. CQDs were further characterized with multiple techniques including high-resolution transmission electron microscope (HR-TEM), X-ray photoelectron microscopy (XPS), X-ray diffraction (XRD), Fouriertransform infrared spectroscopy (FTIR), Raman spectroscopy, UV–visible spectroscopy, Zeta analysis, and optical spectroscopy. They are fundamentally composed of carbon (71.37%), nitrogen (3.91%), and oxygen (24.73%) and are nearly spherical, and uniformly distributed with an average diameter of 2.7 nm. They possess numerous interesting characteristics like broad excitation/emission bands, excitation-sensitive emission, marvelous photostability, reactivity, thermo-sensitivity, etc. A temperature sensor (thermal sensitivity of 0.58% C− 1) with repeatability and reversibility of results is also demonstrated. Additionally, they were found selective and sensitive to ions in aqueous solutions. So, they are also utilized as a fluorescent probe for metal ion ( Fe3+) sensing. The lowest limit of detection (LOD) value for the current metal ion sensor is 19.1 μM/L.

Coal pitch mainly consists of aromatic hydrocarbons, phenolic substances, and aliphatic hydrocarbons, the macromolecular structures formed by these cyclic and chain hydrocarbons through chemical bonding possess diversity and complexity. In this study, medium- and low-temperature coal tar pitch (LCTP) served as the primary material for the production of mesophase pitch via co-carbonization with hydrogenated tail oil (HTO). Aimed to clarify the effects of different amounts of HTO addition and analyze the mechanism of introducing naphthenic and aromatic hydrocarbons on the liquid phase carbonization process. When HTO additive amount is 30%, the carbonized product with the largest content of mature graphite crystals at 25.01%, and the smallest degree of defects. The analytical mechanism demonstrates that the condensation of naphthenic hydrocarbons introduced by HTO produces hydrogen radicals, the hydrogen transfer reaction saturates a significant quantity of free radicals generated within the system, thereby impeding further rapid condensation and curing, and decreasing the viscosity of the system. On the other hand, the aromatic hydrocarbons introduced undergo dehydrogenation and condensation to produce additional polycyclic aromatic hydrocarbons, thereby contributing to a more abundant carbon structure conducive to the development of mesophase pitch. The combined effect of aromatic hydrocarbons and naphthenic hydrocarbons facilitates the slow development of the mesophase structure into a broad-area optical structure. This study provides an effective method for improving the performance of coal-based mesophase pitch, which reduces the production cost and promotes the clean and high value-added utilization of limited resources.

Background: Dairy cows exposed to heat stress have reduced milk production, milk quality, and conception rates, leading to lower profits. This study was conducted to analyze the effect of heat stress according to Temperature-Humidity Index (THI) on the milk production of Korean Holstein cows. Methods: Monthly maximum temperature and average relative humidity data from January 2017 to August 2024 were obtained from 62 observation points used by the Korea Meteorological Administration to calculate the national average. Using this data, the THI, a key indicator for assessing heat stress in Korean Holstein cows, was calculated. Additionally, data from 240,088 Korean Holstein cows, collected through tests conducted by the Dairy Cattle Improvement Center of the NH-Agri Business Group, were analyzed. Results: Comparative analysis of the relationship between THI and milk production revealed that milk yield remained relatively stable until THI reached the “very severe” heat stress threshold (THI ≥ 79). Beyond this level, milk production showed a tendency to decline. Conversely, when THI dropped below this threshold, milk yield tended to recover. Notably, the temperature in September, typically considered part of the autumn season, has been rising in recent years, with THI values now approaching the very severe stress level (THI ≥ 79). Conclusions: These findings suggest that establishing an appropriate farm environment and implementing systematic THI management are essential for mitigating the decline in milk production, as well as the associated economic losses, caused by rising domestic temperatures due to global warming.