• 제목/요약/키워드: Temperature Difference Control

검색결과 1,030건 처리시간 0.029초

전자선 조사에 따른 산화방지제 및 자외선안정제 첨가 HDPE의 변색 영향과 열적 특성 분석 (The Effect of Electron Beam Irradiation on Discoloration and Thermal Property of HDPE Filled with Antioxidants and UV Stabilizers)

  • 전준표;정승태;김현빈;오승환;강필현
    • 방사선산업학회지
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    • 제7권1호
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    • pp.23-28
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    • 2013
  • In this study, we fabricated high density polyethylene (HDPE) composites filled with antioxidants and UV stabilizers. The electron beam irradiation on the fabricated composites was carried out over a range of absorbed doses from 50 to 200 kGy to confirm the changes of discoloration. The changes of discoloration were characterized using a color difference meter and FT-IR for confirming the changes of the color difference and structural change. It was observed that the color difference of IRGANOX 1010-, IRGAFOS 168-, and TINUVIN 328- added HDPE was higher than that of the control HDPE by electron beam irradiation. The melting temperature of UV stabilizer-added HDPE was not significantly changed by electron beam irradiation. However, the melting temperature of phenol-containing antioxidant-added HDPE was increased with increasing the absorbed dose. And the melting temperature of phosphorus-containing antioxidant-added composite was decreased with increasing the absorbed dose.

Effect of Recycled Paper Mulch on Yield of Fall-grown Potato

  • Lee, Byun-Woo;Cui, Ri-Xian;Lee, Suk-Ha
    • 한국작물학회지
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    • 제47권1호
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    • pp.68-73
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    • 2002
  • High temperature during sprout emergence period of potato (Solanum tuberosum L.) is a major limitation to the yield of fall-grown potato in Korea. To explore the possibility of improving the yield of fall-grown potato through recycled paper mulching, the changes of soil environment and the growth and yield of potato cv. Daeji as affected by three mulching treatments of non-mulched control, recycled paper mulching (RPM), and black polyethylene film-mulching (BPFM) were examined over two fall seasons at Suwon, Korea. The mulching materials were a recycled mulch paper with 110 g/$m^2$ and a thickness of 0.1 mm, which was manufactured from old corrugated containers for this experiment and a commercial black polyethylene film with a thickness of 0.01mm. On an average throughout the growing period, the soil temperature with RPM at the 5-cm depth was lower by 0.4-1.1$^{\circ}C$ than that of the control. The maximum temperature during daytime in RPM was lowered by approximately 1 to 5$^{\circ}C$ according to the weather condition during emergence period, the difference being great on a fine day. The soil temperature with BPFM was much higher than the control. The effect of the mulching treatments diminished as the canopy became developed. The mulching treatments were more advantageous than the control in the conservation of soil water. Moreover, RPM and BPFM efficiently suppressed the occurrence of weeds until the potato harvest. RPM improved the emergence significantly due to lower soil temperature, whereas BPFM showed much poorer emergence than the control. Growth after emergence and yield were significantly higher in RPM than in the control and BPFM. It was concluded that the significantly improved yield in RPM compared to that in the control was mainly due to the improvement of the sprout emergence and tuber growth accompanied by lower soil temperature and better conservation of soil water.

퍼지제어에 의한 자연환기온실의 온도제어 (Temperature Control of Greenhouse Using Ventilation Window Adjustments by a Fuzzy Algorithm)

  • 정태상;민영봉;문경규
    • 생물환경조절학회지
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    • 제10권1호
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    • pp.42-49
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    • 2001
  • 온실의 환기제어시 외기의 온도와 풍속변화에 보다 유연하게 대처하면서 온도제어성능을 향상시키기 위하여 퍼지제어 알고리즘을 수립하고 제어실험을 실시하였다. 환기창을 열어 환기 시 온실의 실내온도 변화는 실내외온도차 및 외기 풍속의 세기와 방향에 영향을 받으므로 실내온도 기울기를 퍼지변수의 하나로 취급하여 퍼지변수의 수를 줄였다. 설정온도가 일정할 때 제어오차의 증분은 실내온도 증분과 같으므로, 전건부 퍼지변수는 제어오차(실내온도-설정온도)와 그 증분으로 결정하고, 후건부 퍼지변수는 환기창열음량 증분으로 결정하여 실내온도 하나만의 계측으로 제어출력이 가능한 퍼지제어 알고리즘을 구성하였다. 퍼지변수의 범위는 기초환기실험을 통하여 결정한 후 제어주기 3분을 갖는 실제실험 시 최적 값으로 보정하였다. 전건부 퍼지변수인 제어오차와 제어오차 증분의 최적범위는 각각 목표 제어오차의 3배와 1.5배, 후건부 퍼지변수인 환기창열음량 증분의 최적범위는 최대 열림량의 30%로 나타났다. 최적화한 19개의 퍼지규칙을 적용한 퍼지제어 알고리즘을 개발하고 상대적 성능평가를 위하여 최적 게인을 부여한 PID제어와 비교하였다. 퍼지제어와 PID제어의 실내온도 제어오차는 각각 1.3$^{\circ}C$, 2.2$^{\circ}C$ 미만으로 나타났다. 퍼지제어와 비교하였다. 퍼지제어와 PID제어의 실내온도 제어오차는 각각 1.3$^{\circ}C$, 2.2$^{\circ}C$ 미만으로 나타났다. 퍼지제어는 PID제어에 비해 환기창 적산열음량, 조작회수 및 반전조작회수가 0.4배, 05배 및 0.3배로 적게 나타나 외기풍속과 실내외온도차의 변동에 유연하게 대처하며 환기창의 점진적 여닫음 조작이 가능하고, 조작에너지도 1/2로 줄일 수 있는 것으로 나타났다.

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소나무재의 촉진열화실험에 따른 재색변화에 대한 연구 (Study on the Color Changing of Pine by Accelerated Weathering Test)

  • 김광철
    • 한국가구학회지
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    • 제23권2호
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    • pp.152-162
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    • 2012
  • The color changing of the wood surface was tested by accelerated weathering test that can simulate the outdoor condition with short period. In early parts of accelerated weathering test, weight and volume of specimen all were increased due to the moisture evaporation by its high temperature and illumination level, but weight and volume of specimen all were decreased from middle parts to last. However, significancy showed between control group and accelerated weathering test group in terms of weight and volume. According to the results of color-difference meter, in the early parts of the accelerated weathering test lightness, redness and yellowness all showed a clear increasing or decreasing trend. However, after three weeks all values were almost never change. Until the early parts of the test, lightness was decreased and there was not a considerable change after three weeks in the test. Redness showed a some change in early parts of the test, but this also showed not great change after middle parts of the test as like lightness. Yellowness also showed same pattern. These results could be verified through the visual inspection. As like weight and volume, significancy showed between control group and accelerated weathering test group in terms of color-difference test. In all accelerated weathering test group, color-differences of after test was lower than that of before test. To correctly analyze this cause, more additional research will be need on each of temperature, humidity and illumination factors.

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황기탕이 생쥐의 불감증발(不感蒸發)을 통(通)한 수분손실(水分損失)에 미치는 실험적(實驗的) 연구(硏究) (Experimental studies on the effect of insensible water loss of Hwangkitang in mice)

  • 신원규;이진용;김덕곤
    • 대한한방소아과학회지
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    • 제7권1호
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    • pp.17-34
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    • 1993
  • Experimental studies were done to know effect of insensible water loss of Hwangkitang(HKT) in mice. After administration of extract of HKT to the mice, changes of body temperature, body weight, serum Sodium and chloride ion was measured. And sametime, serum antibody to SRBC, delayed hypersensitivity and phagocytic activity of polymorphonuclear leukocytes(PMN) was measured to know immunologic effect. The results obtained as follows; 1. After exposure to $40^{\circ}C$ environment, increment of body temperature in treated group was slower than control group during first 40 minute, and no difference after 40 minute. 2. After exposured to $40^{\circ}C$ environment, decrement of body weight in treated group except administration group of 1.0g/kg extract of HKT was slower than control group during first 40 minute, and no difference after 40 minute. 3. After exposured to $40^{\circ}C$ environment, decrement of body weight in administration group of 4.0g/kg extract of HKT to mice was slower than control group during first 20 minute(p<0.005). 4. After exposure to $40^{\circ}C$ environment there was no stastical difference between treated group and control group in changes of serum sodium and chloride ion. 5. There was no statistical differences between treated group and control group in changes of serum antibody, delayed hypersensitivity and phagocytic activity of PMN.

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The effect of dietary ions difference on drinking and eating patterns in dairy goats under high ambient temperature

  • Nguyen, Thiet;Chanpongsang, Somchai;Chaiyabutr, Narongsak;Thammacharoen, Sumpun
    • Asian-Australasian Journal of Animal Sciences
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    • 제32권4호
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    • pp.599-606
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    • 2019
  • Objective: The present study was carried out to evaluate the effect of high dietary cation and anion difference (DCAD) rations on diurnal variations in eating and meal patterns, water intake and urination patterns in dairy goats fed under high ambient temperature (HTa). Methods: Ten crossbred dairy goats during peri-parturition period were selected and divided into two groups of five animals each. Experimental diets were control DCAD (control, 22.8 mEq/100 g dry matter [DM]) and high DCAD (DCAD, 39.1 mEq/100 g DM). The composition of two diets consisted of 44% corn silage and 56% concentrate. From the 2nd week to 8th week postpartum, goats were fed ad libitum twice daily either with the control or DCAD total mix ration with free access to water. The spontaneous eating and drinking patterns were determined. Results: The environmental conditions in the present experiment indicated that goats were fed under HTa conditions (average peak THI = 85.2) and were in heat stress. In addition to the typical HTa induced tachypnoea in both groups, the respiratory rate in the DCAD group was significantly higher than the control group (p<0.05). Although the goats from both groups showed comparable level of eating, drinking and urination during experiment, the meal pattern and water intake were different. High DCAD apparently increased eating and meal patterns compared with the control. At week 8 postpartum, goats from high DCAD group had significant (p<0.05) bigger meal size and longer meal duration. Moreover, high DCAD appeared to increase night-time water intake (p<0.05). Conclusion: Both meal pattern and night-time drinking effects of DCAD suggested that feeding with high DCAD ration may alleviate the effect of heat stress in dairy goat fed under HTa conditions.

Effect of the root-zone temperature grown in the greenhouse on the growth of chives

  • Jung, Kwan-hui;Han, Sangjun
    • 한국작물학회:학술대회논문집
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    • 한국작물학회 2017년도 9th Asian Crop Science Association conference
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    • pp.222-222
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    • 2017
  • This study aimed to determine an optimal temperature of root zone for the chive cultivation in a greenhouse during the winter season that may raise the possibility of chive (Allium schoenoprasum L.) harvest any time year-round by reducing energy consumption. The maximum and minimum temperatures of root zone were 26.8 and $19.8^{\circ}C$ for the R-Z20, 28.3 and $23.6^{\circ}C$ for the R-Z25 and 22.4 and $14.3^{\circ}C$ for the control. The highest fresh weights of shoot and root, plant height, root length and stem diameter were observed in the R-Z20 treatment. There was no significant difference in the growth between the R-Z25 and control treatment. These results suggest that the optimal temperature of root zone is $20^{\circ}C$ for the chive cultivation in the greenhouse during winter season.

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PLC와 컴퓨터를 이용한 식물생산공장의 환경제어 (Environmental Control of Plant Production Factory Using Programmable Logic Controller and Computer)

  • 김동억;장유섭;김종구;김현환;이동현;장진택
    • 생물환경조절학회지
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    • 제15권1호
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    • pp.1-7
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    • 2006
  • This study was conducted to develop a system and an control algorithm for control the environment of a plant factory. The greenhouse control system for environmental control was largely composed of a computer and a PLC. The screen of control program was composed of a greenhouse figure which was included machinery and equipments for greenhouse, the graph of environmental factors of inside greenhouse and the image of greenhouse. In order to reduce temperature change, the operation time of ventilation window was changed by 3 stage according to difference between a target and present temperature. When is heating, a temperature variation was shown to be $16.7{\pm}0.8^{\circ}C$. When is cooling, a temperature variation was shown to be $23.1{\pm}0.6^{\circ}C$. When is humidifing, a humidity variation was shown to be $39.3{\pm}1.6^{\circ}C$ %RH. An environmental control system and a control algorithm were proved that it was shown a good performance in a control accuracy. So a computer control system should be adapted to a control system of a greenhouse and a plant factory.

고주파열응고술을 이용한 요부교감신경절제술에서 수술기주위의 온도변화 (Perioperative Temperature Changes Observed in Cases of Lumbar Sympathectomy Using RF Thermocoagulation)

  • 정배희;신근만;김현주;이기헌;김태성;홍순용;최영룡
    • The Korean Journal of Pain
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    • 제13권2호
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    • pp.196-201
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    • 2000
  • Background: Currently, minimally invasive operations are preferred to open surgery whenever possible. Lumbar sympathectomy using RF (radiofrequency) thermocoagulation is both safe and minimally invasive. The problem with the technique is that it cannot be performed successfully in a significant number of cases. If the temperature change in the sole is monitored immediately after the procedure then it can be determined if the procedure needs to be repeated. Methods: A curved tip cannula, 150 mm long with a 10 mm active tip, was used for RF lumbar sympathectomy. The temperature of the soles of both the foot on the affected side and the foot on the control side was monitored immediately before the procedure, immediately after making the L2 lesion, immediately after making the L3 lesion and at 5, 10, and 15 minutes after the procedure. Results: No statistically significant difference was observed in the temperature of the two soles before making the lesions. In the 24 of the 27 patients, there were prominent differences in temperature between the two soles at 10 minutes after the procedures. 11 of the 24 patients showed a significant temperature change after the first trial. But the remaining 13 required a second lesion on L2 and L3. Conclusions: We judged the success of the operation in the operating room by monitoring the temperature difference in the soles of the feet. When no increase in the temperature difference is observed, we can move the electrode and make another lesion. With this procedure, we can drastically increase the success rate of the procedure.

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저수지를 포함한 도시하천의 저서성 대형무척추동물 군집구조 (Community Structure of Benthic Macroinvertebrates in an Urban Stream with a Reservoir)

  • 김필재;김진영;공동수
    • 한국물환경학회지
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    • 제29권6호
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    • pp.825-831
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    • 2013
  • The Suwon stream which consists of a mountainous reach, an artificial reservoir and an urban reach provides benthic macroinvertebrates with various habitats. This study was conducted to find out the influence of reservoir sluice control and water quality on benthic macroinvertebrates community in the Suwon stream from June to August, 2011. As a result, substrate composition showed little difference between the upper site (S2) and the lower site of the reservoir (S3). At site S3, water velocity was fastest, and water temperature was lowest due to the intermediate depth discharge of the reservoir. Cheumatopsyche brevilineata which prefer fast water velocity was dominant at site S3. Some biotic indices (H', J, and R) of site S3 decreased significantly whereas Benthic Macroinvertebrate Index (BMI) showed little difference between site S2 and site S3. EPT showed a negative correlation with water temperature. The sluice control of the reservoir leaded variations of water velocity and temperature, and seemed to make the state of aquatic ecosystem worse.