Fatigue Crack Retardation and Retardation Mechanism in Variable Loading (The Effects of Crack Tip Branching in Crack Growth Retardation)

Song, Sam-Hong,Kwon, Yun-Ki Korean Society for Precision Engineering 2002 International Journal of the Korean Society of Pre Vol.3 No.3

In order to study the fatigue crack and retardation mechanism in variable loading, the effects of crack tip branching in crack growth retardation were examined. The characteristics of crack tip branching behavior were considered with respect to microstructure and crack tip branching angle was examined. Crack tip branching was observed along the grain boundary of finite and pearlite structure. It was found that the branching angle ranges from 25 to 53 degrees. Using the finite element method, the variable of crack driving farce to branching angle was examined. The effective crack driving farce (K$\_$eff/) decreased as the branching angle increased. The rate of decrease was 33% for kinked type and 29% for forked one. It was confirmed that the effect of crack tip branching is a very important factor in crack growth retardation. Therefore, crack branching effect should be considered in building the hypothetical model to predict crack growth retardation.

한약투여가 소아의 성장에 미치는 영향

정성민,김덕곤,이진용,조형준,Jung, Sung-Min,Kim, Deog-Gon,Lee, Jin-Yong,Cho, Hyung-Jun 대한한방소아과학회 2004 대한한방소아과학회지 Vol.18 No.2

Objective : We used herbal medicine to treat various disease and also to keep good general condition of children. We aimed to evaluate the effect of herbal medicine on the growth of children treated with herbal medicine. Method: We studied 187 children who visited the department of Pediatrics, KyungHee Oriental Medical Hospital from March 2004 to August 2004. They meet condition as follows; they were treated for more than 6 months and they visited our clinic more than 3 times. Whenever patients visited our hospital, we measured their height, body weight and obesity degree using DS-102(dszenix, Seoul). We measured height percentile of first time visit, and that of last time visit. And we compared them using the Growth Statistics Curve made by the Korean Association of Pediatrics, 1998. Results : The mean growth of total children showed 4.04 percentile upwardly; the growth- up percentile of boys was 4.52 and that of girls was 3.26. Analysis according to disease resulted as follows; children with respiratory disease showed 10.29 percentile growth-up, digestive disease 4.21percentile, urinary disease 4 percentile, allergic disease 2.65 percentile, weak children 2.52 percentile and other disease 3.19 percentile. Conclusion : Herbal medical treatment helped growth not only in children who took medicine for growth retardation problem but children with various disease. Moreover herbal medical treatment applied to keep good general condition of children also gave positive effect on the growth of children.

자궁내 성장 지연증 소아에서 혈청 IGF-I, Free IGF-I, IGFBP-1, IGFBP-3 농도에 대한 연구

황일태,박은애,김경희,김호성 대한소아내분비학회 1999 Annals of Pediatirc Endocrinology & Metabolism Vol.4 No.2

UV Effect on Plant Growth

Kondo, Noriaki,Tou, Seiji,Takahashi, Shinya,Nakajima, Nobuyoshi Korean Society of Photoscience 2002 Journal of Photosciences Vol.9 No.2

UV-B radiation gives harmful effects on plants, such as production of several types of DNA lesions, and growth inhibition. On the other hand, plants have some protective mechanisms, including filtering effect due to accumulation of phenolic compounds in epidermal cells and reactivation of DNA lesions, which are enhanced by UV-B irradiation. We have investigated the mechanism of UV-B effects on plants using cucumber seedlings as plant materials. Cucumber plants were cultivated in an artificially lit growth chamber. Supplemental UV-B irradiation, of which intensity was almost equal to the level of natural sunlight, retarded the growth of first leaves. The growth retardation must result trom the inhibition of cell division and/or cell growth. Microscopical observation of leaf epidermis suggested that the growth retardation might be mainly caused by cell growth inhibition. The retardation was, however, restored within 2 or 3 days after the termination of UV-B irradiation. It is known that UV-B irradiation lowers the activity of photo system II (PS II). In the present experimental conditions, however, UV-B irradiation has little effect on PS II activity as estimated by chlorophyll fluorescence. The stomatal conductance, a major factor determining photosynthetic rate, of first leaves increased during the growth. The increase of stomatal conductance was suppressed by UV-B irradiation and restored by termination of the irradiation. It has not been clear, however, what mechanisms are involved in the suppression of increase of stomatal conductance.

예비압입에 의한 Al 5052-H18의 피로균열 지연특성 연구

황정선(Jungsun Hwang),조환기(Hwankee Cho),김주언(Jueon Kim) 한국항공우주학회 2004 韓國航空宇宙學會誌 Vol.32 No.1

본 논문은 Al 5052-H18 판재에서 피로균열성장을 지연시키기 위한 방법으로써 예비압입의 적용 기법과 균열성장지연 효과에 관하여 기술하였다. 시편은 두께가 일정한 한쪽 모서리 균열이 있는 시편을 사용하였으며, 균열성장률이 최소가 되는 압입력을 찾아내기 위해서 압입력을 변화시키면서 피로시험을 수행하였다. 시험결과로부터 압입력의 크기에 따라 균열지연효과가 달라지며, 예비압입에 의한 균열성장지연 거동 특성이 효과적으로 나타남을 확인하였다. 균열지연 거동형태는 압입력의 크기에 무관하게 일정한 메커니즘을 보여주었으며 이로부터 예비압입시 균열성장거동 특성에 대한 정성적 모델을 도출하였다. This paper described the retardation effect of fatigue crack growth and application technique of pre-indentation to decelerate the crack propagation rate in the thin sheet of 5052-H18 aluminum alloys. The test specimen with a single-sided edge crack was used. A series of fracture test was conducted to determine the optimum indentation force showing the maximum retardation effect. Test results indicate that crack retardation effect depends on the level of indentation force and the pre-indentation contributes effectively for crack growth retardation. The typical model of crack growth retardation mechanism by pre-indentation is derived from the fact that the behaviors of crack growth retardation show similar mechanism to each indentation force.

안구 운동 프로그램이 자궁 내 태아 발육 지연 아동(IUGR)의 시각 운동 통합 능력에 미치는 영향

조성해 ( Seong Hae Cho ),조영남 ( Young Nam Cho ) 대한인지재활학회 2013 대한인지재활학회지 Vol.2 No.2

목적: 본 연구는 자궁 내 태아 발육 지연 아동을 대상으로 안구 운동 프로그램이 시각 운동 통합 능력에 미치는 영향을 알아보기 위해 실시하였다. 연구방법: 본 연구는 대구 N병원의 소아재활센터에서 외래 치료를 받는 대칭성 자궁 내 태아 발육 지연(symmetric IUGR) 진단을 받은 남자 아동을 대상으로 실시하였다. 치료는 안구 운동 프로그램을 주 3회 실시하였고 치료의 연속성과 효과를 위해 2013년 3월 14일부터 5월 14일까지 8주 동안 진행하였다. 안구 운동 프로그램을 진행하기 전 아동의 전반적인 발달 검사(BayleyⅢ, DDSTⅡ)를 실시하였고, 시각 운동 통합 발달 검사(VMI)를 통해 사전, 사후 평가를 실시하여 비교 분석하였다. 결과: 자궁 내 태아 발육 지연 아동에게 안구 운동 프로그램 중재를 시행한 후 중재 전에 비해 VMI 점수가 향상된 것으로 나타났다. 결론: 본 연구는 자궁 내 태아 발육 지연 아동에게 안구 운동 프로그램 중재가 시각 운동 통합 능력에 긍정적인 영향을 미친다는 것을 알 수 있었다. Objective: The purpose of this study is to investigate the effects of an eye movement program on visual motor integration ability of child with Intrauterine Growth Retardation. Methods: Subject was diagnosed symmetrical intrauterine growth retardation(IUGR) of child with male, and received outpatient treatment in N Hospital`s pediatric rehabilitation center. Subject was received treatment three times a week using the eye movement program, and conducted in 2013 March 14 to May 14 during 8 weeks for effectiveness and continuity of intervention. BayleyⅢ, DDSTⅡ were given for overall development evalution before the eye movement program. The eye movement program consists of 6 types of eyemovements; static fixation, tracking eye movement, pursuit eye movement, saccadic eye movement, vestibulo-ocular movement, vergence eye movement. Developmental test of visual-motor integration(VMI) was used for evaluation of visual motor integration ability, and preliminary evaluation, interim evaluation, subsequent evaluation were performed. Result: Subject child who underwent eye movement after the intervention, compared to before the intervention showed improved VMI scores. Conclusion: This results show that an eye movement program is effective for an improvement in visual motor integration ability of child with intrauterine growth retardation. The following study, children with intrauterine growth retardation can be applied to a variety of programs.

Effect of Streptozotocin-Induced Diabetes on Bone and Heart Development in Juvenile Rats

Kim, Joo-Heon,Lee, Young-Jeon,Lee, Sang-Un,Suzuki, Takao,Lee, Sang-Kil,Kang, Tae-Young,Hong, Yong-Geun The Korean Society of Animal Reproduction 2010 Reproductive & developmental biology Vol.34 No.2

Our objective of current study was to investigate the development of bone and heart in association with diabetes mellitus (DM). DM was induced by administering an intraperitoneal injection of streptozotocin (STZ; 60 mg/kg) to 4-week-old Sprague-Dawley rats. Body weight and blood glucose were monitored, and rats were sacrificed after 2 or 5 weeks. The left ventricle (LV), including the interventricular septum, was weighed, and body weight and tibial bone length were assessed. Young diabetic rats showed reduced growth in terms of tibial length and body weight compared to controls. Moreover, diabetic males showed more significant growth suppression and reduced LV size than diabetic females. Morphometric analysis of tibiae from diabetic rats revealed suppressed bone growth at 2 and 5 weeks, with no difference between genders. STZ-induced diabetes decreased bone growth and retarded pre-pubertal heart development. As a result, diabetes may increase cardiovascular risk factors and lead to eventual heart failure. Therefore, new therapeutic approaches are required for diabetic children exhibiting growth retardation. Heart growth factor, exercise, and cardiopulmonary physical therapy may be required to promote heart development and physiological function.

외래식물 핑크뮬리(Muhlenbergia capillaris)의 메탄올 추출물이 식물 생장에 미치는 영향

홍민지(Minji Hong),보셀라(Sela Bo),장혜정(Hyejeong Jang),조남규(Nam-kyu Cho),황기환(Ki Hwan Hwang),손하라라잔 칸다사미(Kandhasamy Sowndhararajan),홍선희(Sun hee Hong),이용호(Yong Ho Lee),김성문(Songmun Kim) 한국잡초학회 2021 Weed & Turfgrass Science Vol.10 No.3

전국의 많은 지방자치단체에서 외래식물인 핑크뮬리를 무분별하게 도입하여 관상용으로 식재하고 있다. 핑크뮬리는 자생식물과 경쟁하여 국내 생태계에 언제든지 영향을 미칠 수 있지만 이에 대한 연구는 전무한 형편이다. 본 연구에서 저자들은 외래식물인 핑크뮬리가 식물의 생장에 어떠한 영향을 미치는지 조사하였다. 개화기의 핑크뮬리 식물을 채취하여 메탄올 추출물을 얻고 in vitro에서 seed bioassay, 온실 조건에서 토양 처리 및 경엽 처리 실험을 수행하였다. 핑크뮬리 메탄올 추출물의 유채식물에 대한 뿌리 길이 및 생체중에 대한 GR50 값은 각각 4,147 및 4,997 μg mL<SUP>-1</SUP> 이었는데, 이와 같은 결과는 핑크뮬리가 타감작용을 나타낼 가능성이 존재한다는 것을 나타낸다. 10 종의 식물종자가 파종된 토양에 핑크뮬리 추출물(10 kg ha<SUP>-1</SUP>)을 살포한 결과 어떠한 식물생장 저하도 관찰되지 않았다. 그리고 핑크뮬리 추출물(10 kg ha<SUP>-1</SUP>)을 식물의 경엽에 살포한 경우에도, 피에서의 미약한 피해를 제외하고는, 대부분의 식물에서는 생장억제나 약해가 발견되지 않았다. 결론적으로 외래식물인 핑크뮬리는 in vitro에서는 알렐로파시 효과를 나타내었만 in vivo에서는 다른 식물의 생장에 영향을 주지는 않았다. Pink Muhly is planted and managed for ornamental purposes by many local governments in Korea across the country. However, it could affect the domestic ecosystem at any time and compete with native plants due to its exotic nature. The objective of this study was to understand whether pink muhly affects the growth of plants. We obtained the methanol extract from a fully grown pink muhly plant and executed an in vitro seed bioassay followed by soil treatment and foliage treatment experiments under greenhouse conditions. The growth retardation (GR) 50 values, at which plant growth is inhibited by 50%, of methanol extract against root length and weight were 4,147 and 4,997 μg mL<SUP>-1</SUP>, respectively. The results suggest that Pink Muhly may possess allelopathic potential. Application of the Pink Muhly extract (10 kg ha<SUP>-1</SUP>) on the soil in which ten plants were planted, did not show any adverse effect. Further, the application of the Pink Muhly extract (10 kg ha<SUP>-1</SUP>) to the foliage did not show any damage and inhibition of growth. Overall results show that although the exotic plant Pink Muhly showed an allelopathic effect, it might not inhibit the growth of other plants.

한국인에서 자궁 내 성장지연 신생아의 망막출혈 빈도

주진호(Jin-Ho Joo),김영균(Young-Gyoon Kim) 대한안과학회 2017 대한안과학회지 Vol.58 No.1

목적: 자궁 내 성장 지연이 있는 신생아 27명 중 망막 출혈이 있는 환자 3예를 보고하고자 한다. 증례요약: 강동경희대학교병원 신생아 중환자실 환자 중에서 자궁 내 성장 지연이 있는 27명의 안과 협진 환아 중 도상검안경검사를 이용하여 망막 출혈 여부를 확인하였다. 3명의 환아가 망막 출혈의 소견을 보였다. 3명 환아의 평균 재태 연령과 출생 체중(g)은 37+6주/2,086.7 g이었으며, 환아 3명 중 한 명의 산모는 양수 과소증이 있었다. 분만 방법은 망막 출혈이 있는 환아 3명 중 2명이 질식분만을 하였고 나머지 1명은 제왕 절개를 시행하였다. 3명 모두 출산 당시 분만과 관련된 외상은 없었으며 망막 출혈은 첫 안과검사이후 2주 이내에 호전되었다. 결론: 자궁 내 성장지연 환아에서 망막 출혈 소견을 보인 환아 3예를 관찰하였고, 3예 모두 2주 이내 호전됨을 보고하는 바이다. Purpose: We report 3 cases of patients with retinal hemorrhage among 27 newborns with intrauterine growth retardation. Case summary: Twenty-seven newborns with intrauterine growth retardation were examined using the indirect ophthalmoscope for confirming retinal hemorrhage which was observed in 3 patients. The mean gestational age and birth weight (g) of the 3 patients were 37+6 weeks and 2,086.7 g, respectively. Among the 3 newborns, 1 patient’s mother had oligohydramnios. Two patients were delivered vaginally and 1 by cesarean section. All 3 patients had no birth trauma and the retinal hemorrhage was resolved within 2 weeks after the first eye examination. Conclusions: We observed 3 cases with retinal hemorrhage in neonates with intrauterine growth retardation which improved within 2 weeks.

Diniconazole처리가 천일홍과 금잔화의 생장 및 개화에 미치는 영향

김홍열 한국인간·식물·환경학회 2008 인간식물환경학회지 Vol.11 No.4

본 실험에서는 고가의 생장억제제의 대체가능성을 알아보기 위하여 기존의 생장억제제인 Uniconazole(스미세븐)과 살균제로 사용되고 있는 가격이 저렴한 Diniconazole(빈나리) 처리가 천일홍과 금잔화의 생장 및 개화에 미치는 영향에 대해서 조사하였다. 천일홍과 금잔화 모두 빈나리처리에 의해서 생장이 억제되었다. 천일홍의 경우에는 빈나리 200ppm이 금잔화의 경우에는 400ppm이 스미세븐 5ppm과 비슷한 생장억제효과를 나타내었다. 천일홍의 경우 엽폭은 빈나리 200ppm과 스미세븐처리에 의해서 유의하게 증가하였다. 개화시기는 천일홍과 금잔화 모두 빈나리처리와 대조구간의 차이는 없었다. This experiment was conducted to investigate the effects of Uniconazole(Sumiseven), existing growth retardant, and Diniconazole(Binnari), used as cheap germicide, on the growth and flowering of Gomphrena globosa and Calendula officinalis for the substitutional possibility of expensive growth retardants. The growths of Gomphrena globosa and Calendula officinalis were retarded by Binnari treatment. The Binnari treatments of 200ppm in Gomphrena globosa and 400ppm in Calendula officinalis showed similar growth retardant effect to that of 5ppm Sumiseven treatment. The width of leaf was significantly increased by 200ppm BinnariD treatment and Sumiseven treatment in Gomphrena globosa. The flowering date showed no difference between Binnari treatment and control in Gomphrena globosa and Calendula officinalis.