하우스 인접퇴비는 생리장해 원인

정희돈 한국작물보호협회 1986 자연과 농업 Vol.7 No.6

작물을 시설내에서 재배한다는 것은 재배환경을 외부와 인위적으로 차단한 상태에서 집약관리를 하는 것으로 뜻하지 않은 생리장해가 발생하기 쉽다. 일반적으로 생리장해의 발현증상은 자칫하면 병$\cdot$해충의 증상으로 오인하여 경제적 손실을 입기 쉬운데 겨울철 시설원예에서 발생하기 쉬운 생리장해의 원인과 대책에 대하여 알아본다.

용접부 검사법으로서의 Acoustic Emission

정희돈,권영각,장래웅 대한용접접합학회 1993 대한용접·접합학회지 Vol.11 No.2

용접과 관련되는 분야에서, 재료평가와 비파괴 검사법으로서의 Acoustic Emission의 응용을 살펴 보았다. 재료 평가법으로서의 AE는 다른 시험방법들이 검출해 내지 못하는 재료 내부에서의 미시적인 현상들을 정량적으로 평가할 수 있는 장점을 가지고 있다. 앞으로 새로운 용접재료의 개발이라든지, 고도의 신뢰성이 요구되는 용접부위의 정량적인 평가를 위해서 AE의 응용은 중요한 정보들을 제공하게 될 것이다. 한편 용접구조물의 비파괴적 평가법으로서의 AE는 균열의 동적인 거동 및 균열의 위치를 검지할 수 있다는 장점 때문에 응용범위는 더욱 넓어질 것이다. 여기서 유의하여야 할 점은, 목적으로 하는 AE신호를 수만배 까지 증폭시키는 과정에서 환경잡음의 영향을 무시할 수 없는 경우에는 우선적으로 잡음을 적극적으로 제거하는 고도의 연구도 함께 병행되어야 한다는 것이다.

收穫時期 및 貯藏溫度가 오이의 貯藏力에 미치는 影響

鄭凞敦,李昌垠 영남대학교 자원문제연구소 1994 資源問題硏究 Vol.13 No.-

The experiments were performed to investigate the effect of picking time, storage temperature and alternating temperature of storeroom on shelf life and injury symptoms of cucumber fruits. The less weight loss showed at 12℃. while the highest weight loss occured at room temperature (RT, 20-25℃) . The 80% of marketable fruits was maintained after 10 days storage at 12℃, but completely lost their maketable value at 3℃ storage. When held for 2 days after storage at 3. 6, 9. 12℃ or for 7 days at RT, all fruits were deteriorated and decayed except 12℃ plots. Alternating temperature control from high to low (12→ 9→ 6→3℃) prolonged the storage life. Ascorbic acid in fruits during storage was greatly decreased, but there was no difference among the storage temperatures.

재래종 수집 여화(餘話)

정희돈 한국원예학회 2013 한국원예학회 기타간행물 Vol.2013 No.5

허리보호대 착용에 따른 하지와 허리의 근 활성도및 각도 비교에 관한 연구

정희돈,이주상,유영열 대한치료과학회 2018 대한치료과학회지 Vol.10 No.1

Objective: The objective of this study was to examine whether there are differences in low back and lower extremity muscle activity between when a back belt is worn and when no waist protection band is worn while moving patients. Method: This study was conducted on 50 physical therapists who were working in areas where patients should be moved in C Hospital in located in Gyeonggi-do. The physical therapists were randomly divided into two groups of 25 persons each and the groups moved patients from their wheel chairs to tables wearing a back belt and without wearing any back belt respectively. The muscle activities of the trunks and lower extremities of the subjects were measured using electromyographs while the subjects were moving patients and the angles of their trunks and lower extremities were obtained through video taping and goniometers. Independent sample t-tests were conducted in order to examine differences between the two groups. Results: In the experiment, the group of those who were wearing a back belt and the group of those who were not wearing any back belt did not show any significant difference in muscle activity.(p>.05) However, the group of those who were wearing a back belt and the group of those who were not wearing any back belt showed significant differences in trunk and lower extremity angles.(p<.05) Conclusion: The results mean than back belt make proper postures by reducing lumbar bending angles and increasing knee bending angles when the subjects are moving patients.

버스운송업체의 재무변수가 기업부실에 미치는 영향

정희돈,김찬성,Jeong, Hui-Don,Kim, Chan-Seong Korean Society of Transportation 2006 교통 기술과 정책 Vol.3 No.4

結球形態가 다른 배추의 葉生長 및 葉形指數의 變化

鄭凞敦,尹善柱,金秉烈 영남대학교 자원문제연구소 1991 資源問題硏究 Vol.10 No.-

Leaf growh patterns were compared in the different head shaped chinese cabbages, “Bokdor”(ovata type) and “Cheongsan” (cylindrica type). Many more expanded leaves were observed in "Bokdori" as compared with the "Cheongsan". "Cheongsan" was much higher in head height, but "Bokdori" was bigger in head width. Although no difference was observed in trimmed head weight (except the wrapper leaves) between the varieties, each leaf fresh weight was heavier in "Cheongsan." We also observed the double peaks of maximum growth rate through the growing period. Leaf height, leaf width and midrib were similar growth patterns, however "Cheongsan's" growth rate was more rapid than "Bokdori". Leaf index (leaf length/leaf width was similar through the growing season in "Bokdori" , whereas continuously increased to the 35th leaf in "Cheongsan". "Cheongsan", sylindrica type, was observed very rapid growth rate in early growing period but rapidly decreased in late growing period compared with the "Bokdori" , ovata type.

여객운송기업의 부실예측모형 개발 및 검증

정희돈,최정일 한국기업경영학회 2006 기업경영연구 Vol.13 No.2

오이의 收穫適期 決定

鄭凞敦,尹善柱,金秉烈 영남대학교 자원문제연구소 1992 資源問題硏究 Vol.11 No.-

This experiment was conducted to get the basic data for the optimum fruit harvesting time by investigation of the seasonal content changes caused by fruit growth pattern and days after anthesis in summer cucumber cultivars (Cucumis sativus L. cvs. , "Shinhukjiniu" and"Hukkwangjinju"). Fruit growth was rapidly increased as early as 8 days after anthesis for both cultivars. The growth rate in fruit length was gradually decreased to the blossom end than the upper part (peduncle) of the fruit, Chlorophyll content was maximum at 5 days after anthesis in "Shinhukjinju", whereas continuous increased upto 7 days in "Hukkwangjiniu". Fructose and glucose also observed maximum at 6 days after anthesis in "Shinhukjinju", but increased upto 7 days in "Hukkwangjinju". Sucrose have a tendency to decline through the fruit growth. Ascorbic acid content was decreased after anthesis. In weight loss during the storage, continuous decrease was observed in the earlier harvested fruits than the late ones when stored in room temperature, whereas least weight loss rate was observed in harvested fruit at 7 days after anthesis when stored at 6t, In both cultivars, the best fruit quality was obtained when harvested at 7 days after anthesis.

2.25Cr-1Mo 강의 열화와 기계적 성질변화에 관한 연구

정희돈,Jeong, Hee-Don 대한기계학회 1996 大韓機械學會論文集A Vol.20 No.5

As recieved boiler tuve steel was aged artificially at $650^{\circ}C$ and$690^{\circ}C$ for various time duration to simulate the material deterioration which could be occurred during the operation of fossiol power plants. And the tensile tests, the microhardness tests and the characterization of carbides formed in the aging process were performed to asses the relationship between the mechanical properties and the effect of thermal aging. Furthernore, the amout of Mo-rich carbide were investigated by ondestructive method by noticing the fact that formation of Mo-rich carbide were investigated by ondestructive melthod by noticing the fact that formation of Mo-rich carbides($Mo_6C$) which stabilizes lastly affects the mechanical properties. It was known that the microhardness results of service exposed materials were similar to the ones which are aged at $650^{\circ}C$. The room temperature measurement showed small variation in the yield points and ultimate strength in materials aged at $650^{\circ}C$. Those properties at $540^{\circ}C$ showed the abrupt decrease compared with as received material even if short aging time. And it was found that $650^{\circ}C$ $690^{\circ}C$ aging cause different effects on mechanical properties, although the temperature time parameters(LMP;Larson-Miller parameter) are same. And it was concluded that the aigng at $650^{\circ}C$ is more appropriate to simulate the service exposed condition. Finally, the relationship between high temperature tensile properties and Ip values were established, which offers a potential way of reliability tests onthe power plant components.