• Journal of Bio-Environment Control
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• v.23 no.1
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• pp.11-18
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• 2014

To investigate the influence of surrounding environment on the plant temperature and examine the effect of plant temperature control by fogging and airflow, plant temperature of tomato, inside and outside air temperature and relative humidity, solar radiation and wind speed were measured and analyzed under various experimental conditions in plastic greenhouse with two-fluid fogging systems and air circulation fans. According to the analysis of plant temperature and the change of inside and outside air temperature in each condition, inside air temperature and plant temperature were significantly higher than outside air temperature in the control and shading condition. However, in the fogging condition, inside air temperature was lower or slightly higher than outside air temperature. It showed that plant temperature could be kept with the temperature similar to or lower than inside air temperature in fogging and airflow condition. To derive the relationship between surrounding environmental factor and plant temperature, we did multiple regression analysis. The optimum regression equation for the temperature difference between plant and air included solar radiation, wind speed and vapor pressure deficit and RMS error was $0.8^{\circ}C$. To investigate whether the fogging and airflow contribute to reduce high temperature stress of plant, photosynthetic rate of tomato leaf was measured under the experimental conditions. Photosynthetic rate was the highest when using both fogging and airflow, and then fogging, airflow and lastly the control. So, we could assume that fogging and airflow can make better effect of plant temperature control to reduce high temperature stress of plant which can increase photosynthetic rate. It showed that the temperature difference between plant and air was highly affected by surrounding environment. Also, we could estimate plant temperature by measuring the surrounding environment, and use it for environment control to reduce the high temperature stress of plant. In addition, by using fogging and airflow, we can decrease temperature difference between plant and air, increase photosynthetic rate, and make proper environment for plants. We could conclude that both fogging and airflow are effective to reduce the high temperature stress of plant.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.10
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• pp.1935-1940
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• 2011

The control logic of steam temperature was redesigned, tested and applied to the power plant after its steam temperature equipments had been revised. This power plant use the ancillary gas gotten in the process of making iron in the steel mill. The boiler of power plant has the superheater and reheater to make the superheated steam. The superheater and reheater have the spray valve to control their temperature. The reheater has the gas bypass damper additionally in this plant. The control logics were redesigned in cascade forms and the initial parameters of control logics were calculated from the several step tests. The final parameters could be obtained through the several repeated tests and the feedforward functions were added by temperature deviation and air flow. The power plant is being commercially-operated normally by improved control logics and It is expected that this improved controls help the efficiency improvement and safe operation of plant.

• Korean Journal of Ecology and Environment
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• v.54 no.2
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• pp.102-107
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• 2021

The distribution pattern of species richness was determined by temperature. To examine the relationship between hemipteran richness and temperature, hemipteran species were collected using pitfall traps at six different oak forest sites with different annual mean temperatures in South Korea. Multiple linear regression analyses were conducted with mean annual temperature (MAT) and plant richness to evaluate differences in hemipteran richness. The influences of MAT and plant richness of study sites on hemipteran richness were examined by comparing three models (plant richness+MAT+MAT², plant richness+MAT, and MAT) or two models (plant richness+MAT and MAT). Hemipteran richness showed an inverse diversity pattern as a function of temperature, with higher species richness at lower temperature sites. Meanwhile, Aphididae showed a bell-shaped diversity pattern with the highest value at low medium temperatures. The regression analysis showed that hemipteran richness was affected by temperature and plant richness in their habitats.

• Journal of Plant Biology
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• v.17 no.3
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• pp.107-112
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• 1974

Leaf temperature is complicated with the microclimate and the dry matter production in a plant community. But a daily change of leaf temperature varying by the locality in plant body or plant community is not yet clear. To resolve such a question, following experiment was designed; Helianthus tuberosus L., Glycine max L., Zea mays L., Impomoea batatas Lam., and Cucurbita moschata var. toonas Makino were planted in the different sandy loam, $2m{\times}2m-quadrat$, which has a eastern, southern, western and northern edge. In each plot 17-25 plants were planted and the distances between individuals spaced uniformly. And leaf temperature were measured by MR3-C type thermistor from 14th May through 20th August. It is seems that the upper leaf is affected by solar radiation, the lower leaf by released heat from the earth and the middle leaf by the conditions of both zones. Measuring the temperature of a leaf that is on terminal, central, left and right margins and base part, temperature of control plant in a leaf was sloped during about two hours from noon. It is noticeable as a "noon sleeping" phenomenon.henomenon.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.5
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• pp.332-335
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• 2005

The three Korean wheat cultivars with different plant types; the erect, the middle and the creeping growth habit, were studied for their utilization to solar radiation, temperature changes on the furrow and to provide optimum planting space for producing the high yield in 2003. The average solar radiation rate was lowest for creeping type ($39.2\%$) and highest for erect type ($75.8\%$) The correlation coefficient between the coverage rate and the solar transmission rate was r = 0.8624 which was significant at $5\%$ level. The relative growth of the plant, tiller rate and leaf size was increased in the erect and the middle type at lower plant density, while no change on plant growth at creeping type regardless of plant density. The increase of leaf size in the lower plant density was due to longer flag and the first leaf than those of other plant types. The temperature on the furrow of growing plants was changed by the canopy. The changes in temperature pattern on the furrow according to plant types during winter season was different compared to the non plant ground. The temperature of the nonplant ground was the lowest due to solar reduction increasing the amount of cool air flowing in the furrow.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10a
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• pp.292-296
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• 1992

There are lots of disturbance in the super heater temperature control system of power plant boiler as follows. 1.Burner light off. 2.Excess Air. 3.Burner tilt. 4.G.R fan flow. Temperature control system of super heater in the power plant has delay time about 5 min. So it is difficult to control the super heater temperature in the power plant. This paper show us the application of domestic development DCS to control the super heater temperature in seoul #5 thermal power plant unit.

• Journal of Plant Biology
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• v.17 no.4
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• pp.31-37
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• 1974

Seedlings of Nongbaek representing strong cold tolerant variety of rice plant, Jinheung of medium variety and Tongil of weak variety were used respectively for the present study. These seedlings were water cultured in phytotron which maintained at the daytime and night temperature of 30-$25^{\circ}C$, 20-2$0^{\circ}C$, 20-15$^{\circ}C$ and 15-1$0^{\circ}C$. The growth rate of plant height, tillering rate, increase in dry weight and absorption pattern of important mineral nutrients at their early growth stage under each temperature conditions were observed. Generally, it appeared that Nongbaek was more active in the growth of plant height than Jinheung, and Jinheung was more active than Tongil under low temperature condition. The tillering rate of these three varieties was equally rapid while it was decreased in the order of weak cold tolerant variety, such as Tongil, Jinheung and Nongbaek as the temperature declined gradually. The dry weigh tincreasing curve showed almost the same pattern in the varieties at the treatment of each temperature. Under low temperature conditions, Nongbaek showed higher absorption rate of N per dry weight and higher absorption amount of per plant body, Jinheung followed and Tongil was the lowest. The absorption amount of P2O5 increased in the top part compared with the roots as temperature rose and decreased as temperature declined. There seemed to be no difference of absorption among the varieties which have different cold tolerance each other. Under low temperature the absorption rate of K per dry weight was high, as a whole, especially Nongbaek was markedly higher than the other two. The absorption rate of Ca, Mg and Fe was also equally high in all varieties under low temperature and Nongbaek showed a more absorptive tendency in the absorption amount under low temperature.

• Journal of Applied Biological Chemistry
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• v.63 no.4
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• pp.347-355
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• 2020

Several sensors have been developed for soil and plants to assess plant stress due to climate change. Therefore, the objective of the study is to nondestructively evaluate temperature stress on plant by monitoring climatic and soil conditions and plant responses using various sensors. Plant responses were monitored by electrical conductivity in plant stem and sap flow rate. Electrical conductivity in plant stem reflects the physiological activity of plants including water and ion transport. Fully grown Brassica oleracea var. italica was exposed to 20/15 ℃ (day/night) with 16 h photoperiods as a control, low temperature 15/10 ℃, and high temperature 35/30 ℃ while climatic, soil, and plant conditions were monitored. Electrical conductivity in plant stem and sap flow rate increased during the day and decreased at night. Under low temperature stress, electrical conductivity in plant stem of Brassica oleracea var. italica was lower than control while under high temperature stress, it was higher than control indicating that water and ion transport was affected. However, chlorophyll a and b increased in leaves subjected to low temperature stress and there was no significant difference between high temperature stressed leaves and control. Free proline contents in the leaves did not increase under low temperature stress, but increased under high temperature stress. Proline synthesis in plant is a defense mechanism under environmental stress. Therefore, Brassica oleracea var. Italica appears to be more susceptible to high temperature stress than low temperature.

• The Plant Pathology Journal
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• v.18 no.4
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• pp.199-203
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• 2002

Soft rot occurred severely in onion bulbs stored under low temperature ($5^{\circ}C$) in storage houses at Changyoung, Kyungnam province, Korea in early 2000. Water-soaking and yellowish-brown lesions initially appeared on the outside scales of diseased onion bulbs, gradually progressing into the inside scales. Among the bacterial isolates obtained from the lesions, K-2 isolate was found to be responsible for the disease, which grew at a temperature range of from $0^{\circ}C$ to $36^{\circ}C$ with optimum temperature of $00^{\circ}$-$33^{\circ}C$. However, it showed strong pathogenicity to onion bulbs at $25^{\circ}C$ and $5^{\circ}C$ at 3 days and 2 months, respectively. The bacterium also caused soft rot on potato and showed hypersensitive reactions to tobacco and potato. The causal bacterium of onion soft rot was identified as Pseudomonas marginalis based on morphological, biochemical, and physiological characteristics including LOPAT, Soft rot in onion under low temperature storage caused by P. marginalis has not been previously reported.

• Plant Resources
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• v.5 no.2
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• pp.155-160
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• 2002

The heading date is known to be controlled by two kinds of genetic constituent, photosensitivity and basic vegetable phase. For the latter, the effect of temperature in early growth period is critical to determine the shortness of vegetative growth periods in plant's life. A phytotron experiment on 55 rice cultivars, consisting of two ecotypes of rices, indica and japonica, was conducted at high and low temperature treatments at early growth stage to investigate the possible role of plant growth stimulus by high temperature to associate with shortening of heading date. The high temperature during the early growth stage stimulated the rice growth as measured by plant height with much difference of the growth response between indica and japonica. The conclusive finding that these growth stimulus in early growth stage was highly correlated with the acceleration of heading is, more or less, correlated with the heading of the late growth stage although we could not conclude the genes for early plant growth stimulus by high temperature is the same genes as the genes for accelerating of heading in the late growth stage of plants.