PURPOSES : The increasing heat wave warnings during the summer season in Korea have significant impacts on daily life and industry as a whole, especially in urban areas (such as areas with asphalt and sidewalk pavements). Heat waves directly affect urban heat island and heat dome phenomena. Various urban temperature reduction measures are being discussed to reduce urban heat islands and heat dome phenomena and to improve citizen safety against summer heat waves; suggestions include thermal packaging, rooftop greening, and expansion of vegetation areas. There is a lack of analysis on the methodology for increasing the road spraying effect during summer heat waves (e.g., there is no systematic engineering study on the effect from reducing the temperature of the road spraying during a heat wave in the city) and on the types of road pavements in the city. In addition, as the asphalt pavements of roadways and block pavements installed in sidewalks account for a considerable portion of all pavements, this study provides a more systematic and scientific approach and procedures for reducing temperatures through road spraying in the city by tracking the effects of heat waves. METHODS : In this preliminary experiment, four types of road pavement materials were selected as test specimens: asphalt test specimens (AP- 300 mm × 300 mm × 50 mm), concrete test specimens (CP-300 mm × 300 mm × 50 mm), impermeable blocks (IB-200 mm × 200 mm × 60 mm), and self-permeable blocks (PB-200 mm × 200 mm × 60 mm). As a test method to evaluate the size and duration of each spray effect package type, the surface temperature of each specimen was measured using thermal imaging cameras every 20 min after spraying at the maximum temperature point of each specimen, and the average surface temperature was analyzed based on the collected temperature data. In addition, to conduct a quantitative analysis of the effect of reducing the surface temperature of road pavements by road spraying in summer, field tests were conducted on asphalt roads and watertight blocks for sidewalks. RESULTS : As a result of the comparative analysis of the spray effect under a 36 ℃ air temperature based on a heat wave warning, the surface temperatures were, from high to low, the asphalt (68.8 ℃), concrete (59.1 ℃), impermeable block (57.3 ℃), and permeable block (58.7 ℃). The asphalt pavement had the greatest effect on the heat island and heat dome phenomena. From measuring the temperature reduction effect and sustainability of each type of road pavement, the surface temperature reduction effects were ranked in the following order: water-permeable block (Δ18.0 ℃), asphalt test piece (Δ17.5 ℃), concrete test piece (Δ12.2 ℃), and water-permeable block (over 240 min). In the report pitching block, the average road surface temperature reduction between the pore recovery and treatment was expected to continue to decrease by approximately -4.3 ℃ on the day of work and approximately -2.4 ℃ on the next day. The expected effect of the temperature reduction owing to simple spraying on the surface of the pore block was evaluated to be limited to the day. CONCLUSIONS : In the road spray effect analysis conducted on the common asphalt road, there was a slight difference in the initial temperature reduction size as the test specimen was measured, but the surface temperature difference between the non-spray section and spray section tended to be approximately Δ3°C after 140 minutes of spraying. Therefore, it was determined that the asphalt pavement temperature reduction plan through road spraying in urban areas in summer would be the most effective if it was repeated twice or more in an hour (between 13:00 and 14:00) on the day of the heat wave.

The acoustic emission (AE) is proposed as a feasible method for the real-time monitoring of the structural damage evolution in concrete materials that are typically used in the storage of nuclear wastes. However, the characteristics of AE signals emitted from concrete structures subjected to various environmental conditions are poorly identified. Therefore, this study examines the AE characteristics of the concrete structures during uniaxial compression, where the storage temperature and immersion conditions of the concrete specimens varied from 15℃ to 75℃ and from completely dry to water-immersion, respectively. Compared with the dry specimens, the water-immersed specimens exhibited significantly reduced uniaxial compressive strengths by approximately 26%, total AE energy by approximately 90%, and max RA value by approximately 70%. As the treatment temperature increased, the strength and AE parameters, such as AE count, AE energy, and RA value, of the dry specimens increased; however, the temperature effect was only minimal for the immersed specimens. This study suggests that the AE technique can capture the mechanical damage evolution of concrete materials, but their AE characteristics can vary with respect to the storage conditions.

The demand for chiller equipment that keeps each machine at a constant temperature to maintain the best possible condition is growing rapidly. PID (Proportional Integral Derivation) control is a popular temperature control method. The error, which is the difference between the desired target value and the current system output value, is calculated and used as an input to the system using a proportional, integrator, and differentiator. Through such a closed-loop configuration, a desired final output value of the system can be reached using only the target value and the feedback signal. Furthermore, various temperature control methods have been devised as the control performance of various high-performance equipment becomes important. Therefore, it is necessary to design for accurate data-driven temperature control for chiller equipment. In this research, support vector regression is applied to the classic PID control for accurate temperature control. Simulated annealing is applied to find optimal PID parameters. The results of the proposed control method show fast and effective control performance for chiller equipment.

Research is being actively conducted on the continuous thin plate casting method, which is used to manufacture magnesium alloy plate for plastic processing. This study applied a heat transfer solidification analysis method to the melt drag process. The heat transfer coefficient between the molten magnesium alloy metal and the roll in the thin plate manufacturing process using the melt drag method has not been clearly established until now, and the results were used to determine the temperature change. The estimated heat transfer coefficient for a roll speed of 30 m/min was 1.33 × 105 W/m2·K, which was very large compared to the heat transfer coefficient used in the solidification analysis of general aluminum castings. The heat transfer coefficient between the molten metal and the roll estimated in the range of the roll speed of 5 to 90 m/min was 1.42 × 105 to 8.95 × 104 W/m2·K. The cooling rate was calculated using a method based on the results of deriving the temperature change of the molten metal and the roll, using the estimated heat transfer coefficient. The DAS was estimated from the relationship between the cooling rate and DAS, and compared with the experimental value. When the magnesium alloy is manufactured by the melt drag method, the cooling rate of the thin plate is in the range of about 1.4 × 103 to 1.0 × 104 K/s.

The overall process, from the pre-treatment of aluminum substrates to the eco-friendly neutral electroless Ni-P plating process, was observed, compared, and analysed. To remove the surface oxide layer on the aluminum substrate and aid Ni-P plating, a zincation process was carried out. After the second zincation treatment, it was confirmed that a mostly uniform Zn layer was formed and the surface oxide of aluminum was also removed. The Ni-P electroless plating films were formed on the secondary zincated aluminum substrate using electroless plating solutions of pH 4.5 and neutral pH 7.0, respectively, while changing the plating bath temperature. When a neutral pH7.0 electroless solution was used, the Ni-P plating layer was uniformly formed even at the plating bath temperature of 50 oC, and the plating speed was remarkably increased as the bath temperature was increased. On the other hand, when a pH 4.5 Ni-P electroless solution was used, a Ni-P plating film was not formed at a plating bath temperature of 50 oC, and the plating speed was very slow compared to pH 7.0, although plating speed increased with increasing bath temperature. In the P contents, the P concentration of the neutral pH 7.0 Ni-P electroless plating layer was reduced by ~ 42.3 % compared to pH 4.5. Structurally, all of the Ni-P electroless plating layers formed in the pH 4.5 solution and the neutral (pH 7.0) solution had an amorphous crystal structure, as a Ni-P compound, regardless of the plating bath temperature.

Photosynthesis and respiration of seagrasses are mainly controlled by water temperature. In this study, the photosynthetic physiology and respiratory changes of the Asian surfgrass Phyllospadix japonicus, which is mainly distributed on the eastern and southern coasts of Korea, were investigated in response to changing water temperature (5, 10, 15, 20, 25, and 30°C) by conducting mesocosm experiments. Photosynthetic parameters (maximum photosynthetic rate, Pmax; compensation irradiance, Ic; and saturation irradiance, Ik) and respiration rate of surfgrass increased with rising water temperature, whereas photosynthetic efficiency (α) was fairly constant among the water temperature conditions. The Pmax and Ik dramatically decreased under the highest water temperature condition (30°C), whereas the Ic and respiration rate increased continuously with the increasing water temperature. Ratios of maximum photosynthetic rates to respiration rates (Pmax : R ) were highest at 5°C and declined markedly at higher temperatures with the lowest ratio at 30°C. The minimum requirement of Hsat (the daily period of irradiancesaturated photosynthesis) of P. japonicus was 2.5 hours at 5°C and 10.6 hours at 30°C for the positive carbon balance. Because longer Hsat was required for the positive carbon balance of P. japonicus under the increased water temperature, the rising water temperature should have negatively affected the growth, distribution, and survival of P. japonicus on the coast of Korea. Since the temperature in the temperate coastal waters is rising gradually due to global warming, the results of this study could provide insights into surfgrass responses to future severe sea warming and light attenuation.

A strain of Alexandrium species was established by isolating cells from Jangmok Bay, Korea. Its morphology and molecular phylogeny based on LSU rRNA gene sequences were examined. In addition, growth responses of this Alexandrium species to changes in temperature, salinity, and nutrient concentrations were investigated. This Alexandrium species from Jangmok Bay had a ventral pore on the 1′, which was morphologically consistent with previously described Alexandrium tamarense and A. catenella. Phylogenetic analyses revealed that this isolate was assigned to A. pacificum (Group IV) within A. tamarense species complex. In growth experiments, relatively high growth rates and cell densities of A. pacificum (Group IV) were observed at 15°C and 20°C. This species also grew under a wide range of salinity. This indicates that this Korean isolate of A. pacificum (Group IV) is a stenothermic and euryhaline species. In growth responses to changes in nutrient levels, enhanced growth rates and cell densities of A. pacificum (Group IV) were observed with additions of nitrate and phosphate. In particular, rapid uptakes of phosphate by A. pacificum (Group IV) were observed in experimental treatments, indicating that the increase in phosphate concentration could stimulate the growth of A. pacificum (Group IV).

The effect of five different constant temperatures (18, 21, 24, 27, and 30±1°C) and a photoperiod of 14 : 10 (L : D) h on the reproduction parameters of Spodoptera frugiperda was studied. The longevity of adult female S. frugiperda decreased with increasing temperature (22.4 days at 21°C and 13.9 days at 30°C) but not at 18°C. The pre-oviposition period and oviposition period was the shortest at 30°C compared to the other temperatures. The total fecundity egg count was 887.4, 1,246.4, 1,348.9, 1,154.9, and 1,034.2 at 18, 21, 24, 27 and 30°C, respectively, during its life span. The survival rate of female S. frugiperda decreased rapidly after 13 days at 18°C, after 14 days at 21°C, after 15 days at 27°C, and after 9 days at 24°C, and 30°C. On the third day after the start of oviposition, 50% of the total fecundity was accomplished. In corn fields at less than the 10-leaf stage, the distribution of S. frugiperda egg masses was observed in the middle and lower plant regions, corresponding to 46.8% and 41.4% of the total egg masses, respectively. Egg masses were mostly found on the underside of the leaf blade (abaxial) of corn (66.7%). After releasing S. frugiperda adults on May 12, May 17, May 25, and May 30, the number of eggs per egg mass was 89.9, 88.5, 126.6, and 127.9, respectively. Egg masses of the subsequent generations of S. frugiperda were observed from late June, and the number of eggs per egg mass was 155.8 in late June, 270.7 in early July, and 303.5 in mid-July.

To investigate the tolerance limit and critical thermal maximum (CTM), behavioral responses of wild goldeye rockfish Sebastes thompsoni according to exposure to high water temperature were observed using a continuous behavior tracking system. As a result, behavioral index (BI) of S. thompsoni in each temperature (20.0, 25.0, and 30.0°C) showed a significant difference (p<0.05) when compared with the value measured in a stable condition of 15.0°C. The activity level of S. thompsoni exposed to 25.0°C decreased sharply after 20 hours. Their rest time at the bottom of experiment chamber increased, and their normal swimming and metabolic activities were disturbed. In addition, at a high water temperature of 30.0°C, S. thompsoni reached the limit of resistance and showed a sub-lethal reaction of swimming behavior, with energy consumption in the body increased and all test organisms died. In conclusion, the eco-physiological response of S. thompsoni to water temperature varied greatly depending on the fluctuation range of the exposed temperature and the exposure time. In addition, the tolerance limit of S. thompsoni to high water temperature was predicted to be 25.0- 30.0°C. The maximum critical thermal that had a great influence on the survival of this species was found to be around 30.0°C.

High-income mushroom crops require complex farming. Therefore, we conducted a test to identify the optimum temperature for the production of antler-shaped Ganoderma lucidum using the King Oyster mushroom cultivation facility. T-N showed 0.28% of oak sawdust and 2.2% of nutritional source. The pH of oak sawdust was 6.0, indicating weak acidity, and that of rice steel was 6.6, indicating neutrality in nutrition source. Study on the quality characteristics of mushrooms showed that the number of days at 25°C were 5~6 and those at 30°C were 3~5; the representative length at 25°C was 57.5 mm and that at 30°C was 92.2 mm; the biological weight at 25 °C was 43 g, which was greater than that at 30°C.

팥나방은 콩과작물 특히 팥을 가해하는 해충으로 알려져 있다. 본 연구는 팥나방의 생물적 특징을 알아보기 위해 발육단계별 발육기간, 성 충의 수명과 번식능력을 7, 10, 13, 16, 19, 22, 25, 28, 31, 34°C 항온조건에서 조사하였다. 알은 7°C와 34°C를 제외한 모든 항온조건에서 부화 하였고 유충은 13~28°C 온도조건에서 성공적으로 성충으로 발육하였다. 알의 발육기간은 25°C까지 온도가 상승할수록 짧아지다가 이후 온도 에서 길어지는 경향을 보였다. 유충, 번데기의 발육기간과 성충수명은 온도가 상승할수록 감소하였다. 팥나방 발육단계별 발육 최저, 최고 한계는 LRF와 SSI모델을 이용하여 계산하였고 발육영점온도와 유효적산온일도는 선형회귀분석을 이용하였다. 1령 유충 부화부터 성충출현까지의 발 육영점온도와 유효적산일은 9.1°C와 264.5DD였다. SSI모델을 이용한 부화부터 성충출현까지 발육최저 및 최고온도는 20.0°C과 32.3°C였고 이들간의 차이 즉 발육적정온도범위는 12.3°C였다. 온도와 관련된 팥나방 성충의 생존과 산란특성을 이용하여 산란모형을 작성하였다. 본 연구 에서 제시한 온도발육모형과 산란모형은 야외에서 팥나방의 개체군동태를 이해하고 콩과작물의 종합적인 해충군관리체계 확립에 기여할 것으로 보인다.

어리팥나방은 콩을 가해하는 Matsumuraeses속 해충으로 알려져 있다. 본 연구는 어리팥나방의 개체군동태를 예측하기 위하여 발육단계별 발육기간, 성충의 수명과 번식능력을 10, 13, 19, 22, 25, 28, 31°C 항온조건에서 조사하였다. 알은 조사된 모든 항온조건에서 부화하였고, 유충 은 10, 13, 31°C를 제외한 온도조건에서 성공적으로 성충으로 발육하였다. 발육단계별 발육기간과 성충 수명은 온도가 상승할수록 감소하였다. 어리팥나방 발육단계별 발육영점온도와 유효적산일은 선형회귀방법을 이용하여 추정하였고 발육최저, 최고한계는 LRF와 SSI모델을 이용하여 계산하였다. 1령 유충 부화부터 성충출현까지의 발육영점온도와 유효적산일은 10.2°C와 492.04DD였다. SSI모델을 이용한 부화부터 성충출현 까지 발육최저 및 최고온도는 16.7°C과 29.1°C였고 이들간의 차이 즉 발육적정온도범위는 12.4°C였다. 온도와 관련된 어리팥나방 성충의 생존 과 산란특성을 이용하여 산란모형을 작성하였다. 본 연구에서 제시한 온도발육모형과 산란모형은 어리팥나방의 개체군모형 작성과 콩 작물의 종 합적인 해충군관리체계 확립에 기여할 것으로 보인다.