• 생물환경조절학회지
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• 제15권4호
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• pp.340-345
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• 2006

A potato (Solanum tuberosum L. cv. Superior) cultivar was grown in aeroponic cultivation system to investigate the effect of root zone cooling in summer. Based on their nutrient uptake, growth responses, and tuberization, the possibilities for potato seed production were determined. Although shoot growth and early tuberization increased in the conventional non-cooling root zone system (root zone temperature of $25\pm2^{\circ}C$), stolen growth, photosynthesis, transpiration rate and number of tubers produced were higher in the cooling root zone system ($20\pm2^{\circ}C$) than in the non-cooling system. Increasing root zone temperature above $25^{\circ}C$ stimulated absorption of K more than T-N, P, Ca, Fe and Mn. On the other hand, root zone temperatures in the range of $20^{\circ}C$ to $25^{\circ}C$ did not affect Mg contents. The lower uptake and supply to leaves of T-N, Fe and Mn at the high root zone temperature promoted early tuberization and advanced haulm senescence. The results stress the importance of keeping root zone temperature to as low as below 20, particularly in summer under temperate Bone.

• 생물환경조절학회지
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• 제17권1호
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• pp.14-19
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• 2008

저온기의 딸기 재배를 위한 기초자료를 얻기 위하여 '아키히메(章姬)'품종을 재료로 딸기의 뿌리 발달에 미치는 저온의 영향과 지하부의 온도와 관련된 지상부의 생육을 조사하였다. $18^{\circ}C$의 근온처리구에서 1차근의 생육이 가장 양호하였으며 $8^{\circ}C$의 저온에서 뿌리의 신장률이 가장 낮았으며, 특히 측근의 수와 길이가 가장 저조하였다. 근부의 온도는 지상부의 생육에도 직접적인 영향을 미쳐서, 낮은 근권 온도에서는 지상부의 생체중, 엽면적, 엽장, 엽폭 및 엽수의 저하를 초래하였다. 본 실험의 결과는 지하부 온도관리의 중요성을 확인할 수 있는 것으로 딸기 촉성재배농가에 유용한 정보로 활용될 수 있을 것이다.

• 한국농공학회논문집
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• 제56권6호
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• pp.149-158
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• 2014

The effects of spot cooling on growing ever-bearing strawberry in hydroponic cultivation during summer by spot cooling system was estimated in plastic greenhouse located in Pyeongchang. The temperature of cooling water was controlled by heat pump and maintained at the range of $15{\sim}20^{\circ}C$. Cooling pipes were installed in root zone and very close to crown. Spot cooling effect was estimated by applying system in three cases which were cooling root zone, crown plus root zone, and crown only. White low density polyethylene pipe in nominal diameter of 16 mm was installed on crown spot, and Stainless steel flexible pipe in nominal diameter of 15A was installed in root zone. Crown and root zone cooling water circulation was continuously performed at flowrates of 300 ~ 600 L/hr all day long. Strawberry yields by test beds were surveyed from Aug. 1 to Sep. 30. The accumulated yield growth rate compared with a control bed of crown cooling bed was 25 % and that of crown plus root zone cooling bed was 25 % and that of root zone cooling bed was 20 %. The temperatures of root spot in root zone cooling was maintained at $18{\sim}23.0^{\circ}C$ and that of crown spot in crown cooling was maintained at $19{\sim}24^{\circ}C$. Also, the temperatures of root spot in crown plus root zone cooling bed was maintained at $17.0{\sim}22.0^{\circ}C$ and that of crown spot was maintained at $19{\sim}25^{\circ}C$.

• 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.

• 한국농공학회논문집
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• 제58권5호
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• pp.71-79
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• 2016

The effects of spot heating for growing the strawberry cultivated in a plastic greenhouse during the winter that were estimated in Nonsan strawberry experiment station located in Chungnam. The temperature of water for heating was controlled by a electric hot water boiler and kept at the range of $22{\sim}24^{\circ}C$. Heating pipes were set up in root zone for root zone heating and very close to crown for crown heating. Spot heating effects were estimated by applying spot heating system in three test factors of heating root zone, crown only and crown plus root zone. The material for crown heating pipe was white low density polyethylene and the nominal diameter of that pipe was 16 mm. The material for root zone heating pipe was flexible stainless steel and the nominal diameter of that pipe was 15A. The flow rate of heating water circulation was 480 L/h and water circulation lasted for all day long. Temperatures, harvest yield by test beds were surveyed from Nov. 10, 2013 to Apr. 29, 2014. The temperature of crown spot for crown heating bed was at the range of $13.0{\sim}17.0^{\circ}C$ during the night and that of crown spot in control bed was at the range of $8.0{\sim}14.0^{\circ}C$. Also, the temperature of root zone for root zone heating bed was at the range of $18{\sim}21.0^{\circ}C$ and that of root zone in control bed was at the range of $13.0{\sim}15.0^{\circ}C$. The cumulative yield growth rate in earlier harvest period (from Dec. 20 to Mar. 15) of crown heating bed was 43% compared with that of control bed and the cumulative yield of crown plus root zone heating bed was 39 % and that of root zone heating bed was 39 %.

• Restorative Dentistry and Endodontics
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• 제29권5호
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• pp.446-453
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• 2004

하악 대구치 근심치근의 danger zone에서 수종의 전동 니켈-티타늄 파일의 근관성형력을 근관성형 전후 치질 두께의 변화를 측정하여 평가하고자 하였다. 기구에 따라 총 40개의 하악 대구치를 10개씩 $Profile^{\circledR}$, GT Rotary file, Quantec 및 ProTaper 4개 군으로 나누고 각 치아당 2개의 근관을 straight up-and-down과 anticurvature 군으로 나누어 근단부 근관을 모두 30번 크기로 일정하게 확대하였다. 수정된 Bramante법을 사용하였으며 술전 및 술후의 근관 상아질 두께를 치수저 하방 1, 3 및 5 mm지점에서 측정, 이원변량분석법으로 통계분석하였다. 모든 군의 danger zone과 safe zone에서의 straight up-and-down 동작과 anticurvature 동작 사이에는 치근상아질 두께변화에 현저한 차이를 나타내지 않았다 (p > 0.05). ProTaper는 danger zone과 safe zone 모두에서 다른 기구에 비해 많은 량의 근관상아질 삭제를 보였으며 특히 분지부 3 mm 수준에서 현저하였다(p < 0.05).

• 한국토양비료학회지
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• 제25권3호
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• pp.242-248
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• 1992

수경재배(水耕栽培)에서 근권온도(根圈溫度)가 상추, 토마토 그리고 오이의 작물생장(作物生長) 및 양분함량(養分含量)에 미치는 영향(影響)을 조사(調査)한 결과(結果)는 다음과 같다. 1. 양액온도(養液溫度)가 증가(增加)할 수록 뿌리의 호흡능(呼吸能)은 증가(增加)하였으며, 양액저온시(養液低溫時)($10^{\circ}C$) 상추가 가장 높은 호흡능(呼吸能)을 보였고, 토마토는 온도증가(溫度增加)에 따른 호흡량(呼吸量) 증가(增加)폭이 컸다. 2. 양액온도(養液溫度) $10^{\circ}C$에서 각 작물(作物)의 뿌리와 잎의 건물중(乾物重)과 엽면적(葉面積)이 현저히 감소(減少)했으나, 양액온도(養液溫度) $20^{\circ}C$와 $30^{\circ}C$에서는 비슷하였다. 3. T/R율(率)과 NAR은 양액온도(養液溫度)가 증가(增加)할수록 일반적(一般的)으로 증가(增加)하지만 저온시(低溫時)($10^{\circ}C$) 토마토와 오이는 뿌리의 생장(生長)이 오히려 저해(沮害)를 심하게 받을 뿐만아니라 엽면적(葉面積)이 크게 감소(減少)했으며, 상추와 오이의 RGR은 저온시(低溫時)에 현저하게 낮았다. 4. $10^{\circ}C$에서 $20^{\circ}C$까지 양액온도(養液溫度)가 증가(增加)하면 각 작물(作物) 모두 질소(窒素), 인산(燐酸), 가리(加里), 칼슘, 마그네슘 함량(含量)이 증가(增加)하나 $20^{\circ}C$부터 $30^{\circ}C$까지는 토마토와 오이의 칼슘함량(含量)만이 계속 증가(增加)하였다. 5. 양액온도(養液溫度) $10^{\circ}C$에서 각(各) 작물(作物) 모두 인산(燐酸)과 마그네슘 함량(含量)이 크게 낮은데, 이는 저온(低溫)에 의한 인산(燐酸)과 마그네슘 흡수(吸收) 저해(沮害)가 큰 것으로 보인다. 6. 오이는 상추나 토마토 보다 양액저온(養液低溫)에 의한 양분흡수(養分吸收) 저해(沮害)를 가장 심하게 받았다.

• 생물환경조절학회지
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• 제11권2호
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• pp.81-87
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• 2002

근권냉방 방식에 따른 냉방 효율과 토마토 생육 특성을 검토하고자 XL냉수순환, 라디에이타 냉풍, 패드냉풍 및 대조구를 처리한 결과는 다음과 같다. 근권부 냉방온도는 공급수온이 17.8$^{\circ}C$일 때 XL 냉수순환구는 18.$0^{\circ}C$ 라디에이타 냉풍구는 27.2$^{\circ}C$, 패드 냉풍구는 20.3$^{\circ}C$였다. 배지 깊이와 시간대별 평균온도는 XL냉수순환구 22.8~24.7$^{\circ}C$. 라디에이타 냉풍구 22.7~24.2$^{\circ}C$, 패드 냉풍구 20.5~23.2$^{\circ}C$, 대조구 25.9~29.6$^{\circ}C$를 나타내어 냉방처리구가 대조구에 비해 5~6$^{\circ}C$더 낮았다. 토마토의 생육에 있어 엽장. 엽폭은 대조구에 비해 컸으며, 생체중 및 건물중의 경우에서도 비슷한 경향이었다 근활력에 있어 대조구는 45.0ug/g에 비해 근권냉방 처리구는 58.5-62.8 ug/g으로 높았으나. 근권냉방 처리구간에는 큰 차이가 없었다.

• 생물환경조절학회지
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• 제7권2호
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• pp.139-143
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• 1998

지중가온시설을 이용한 고구마뿌리혹선충(Meloidogyne incognita Chitwood) 방제를 위하여 지하 20cm 깊이의 최저지온을 각각 30. 40, $50^{\circ}C$ 가온구 및 관행의 무지중가온구로 설정하고 담수구와 무담수구로 나누어 8월 1일부터 8월 5일까지 5일간 가온한 결과, 담수구의 경우 지온 4$0^{\circ}C$에서 5일간, 무담수구의경우 지온 $50^{\circ}C$에 5일간 지중가온처리한 구에서 생존한 유충이 발견되지 않아 선충밀도를 경제적 피해수준 이하로 유지할 수 있을 것으로 사료되었다. 지중가온으로 토양내 OM. P$_2$ $O_{5}$, Ca, Mg함량과 EC는 시험전 토양에 비하여 감소하였는데, 특히 담수처리에서 EC가 현저히 저하하였다.

• Journal of Welding and Joining
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• 제2권2호
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• pp.62-69
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• 1984

In this study, cold crack susceptibility of high strength steel (ABS EH32 Steel) welded zone with shielded metal are welding was investigated by tensile restraint cracking test method. Effects of diffusible hydrogen content on root cracking, lower critical stress, crack initiation and fracture mode, hardness value distribution of welded zone and fractograph were mainly investigated. Following conclusions are made: 1. In the view of the lower critical stress level, wet electrode, containing much diffusible hydrogen content shows lower value than dried electrode. 2. Hardness value(Hv 5kg) in Heat Affected Zone of wet electrode is higher than that of dried electrode caused by hydrogen embrittlement. 3. In the case of wet electrode, root crack is initiated and propagated in Heat Affected Zone and then propagated to weld metal, but using of dried electrode, root crack is initiated in Heat Affected Zone and propagated to weld metal without propagating in HAZ. 4. For wet electrode, quasi-cleavage fracture mode is majorly observed on the fracture surface of HAZ and partially of weld metal due to hydrogen embrittlement.