NR과 SBR 가황물의 경도와 강성도에 대한 온도의 영향

진현호 ( Hyun Ho Jin ),홍창국 ( Chang Kook Hong ),조동련 ( Dong Lyun Cho ),강신영 ( Shin Young Kaang ) 한국고무학회 2007 엘라스토머 및 콤포지트 Vol.42 No.3

본 연구에서는 고무제품의 수치 안정성과 성능유지에 직접적으로 영향을 미치는 중요한 특성 중 하나인 온도변화에 따른 고무재료의 경도변화를 고찰하였다. 새롭게 제작된 International Rubber Hardness Degree(IRHD, Normal type) 경도측정 시험기를 사용하여 미충전된 NR과 SBR시편의 여러 온도에서 경도변화를 측정하였으며 Young`s modulus 값과 비교하였다. NR과 SBR 모두 유리전이온도 근처에서 경도와 Young`s modulus의 급격한 변화를 보였다. 온도가 증가함에 따라 경도와 Young`s modulus 값이 증가하는 경향을 보였으며 이는 분자의 운동성과 엔트로피 영향으로 해석할 수 있다. 카본블랙과 실리카가 충전된 NR과 SBR의 경우 충전제의 함량이 증가함에 따라 경도에 미치는 온도의 영향이 감소함을 관찰하였다. Hardness of rubbery materials, which is important for dimensional stability and product performance, was investigated upon temperature change in this study. A newly developed IRHD (International Rubber Hardness Degree) tester was used to measure the hardness changes of NR and SBR specimens at various temperatures and the hardness values were compared with the Young`s modulus. The hardness and Young`s modulus of NR and SBR showed an abrupt change near the glass transition temperatures. The hardness and Young`s modulus were increased by increasing temperature due to the increased random chain conformation of molecules. The effect of temperature on hardness and Young`s modulus of NR and SBR specimens filled with carbon black and silica was decreased by increasing filler content.

The Role of /x, r, l/ in Sound Changes: OE Breaking and other Processes

Young-Kook Kwon 한국영어학학회 2003 영어학연구 Vol.- No.16

Kwon, Young-Kook. 2003. The Role of /x, r, l/ in Sound Change: OE Breaking and other Processes. English Language and Linguistics 16, 243-270. This paper investigates diphthong-related sound changes that affected the vowel system in Old and Early Middle English in the framework of Optimality Theory. Old English Breaking, Northumbrian Retraction, Anglian Smoothing and Early Middle English Coalescence are paid special attention. Past studies do not answer why these diphthong-related sound changes tend to recur before /x, r, I/ throughout the history of English. In addition, such studies analyze each change individually but do not provide a unified account that captures structural coherence among these changes. It will be shown that the combination of, on the one hand, an enhanced theory of representations reflecting temporal relations of the segments involved and, on the other hand, the Optimality Theory of grammar makes possible a unified and natural account of these sound changes. More generally, this paper lends support to OT as a framework for explaining sound change and variation.

Superconducting MgB2 Wire Drawing Considering Anisotropic Hardening Behavior and Hydrostatic Effect

Young‑Seok Oh,Ho Won Lee,Kook‑Chae Chung,Duck‑Young Hwang,Seong‑Hoon Kang,Jeong Whan Yoon 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.7

Numerical modeling was conducted to investigate the deformation behavior of powder mixture during multi-pass drawingprocesses for multi-filamentary MgB2wire. A modified Drucker-Prager Cap (DPC) model with an elliptical cap surface usingthe new material characterization method was developed to capture the anisotropic hardening behavior and hydrostatic effectof the powder mixture. A number of uniaxial die compaction, cold isostatic pressing, diametrical compression, and uniaxialcompression tests were conducted using different powder densities to characterize the modified DPC model. A commercialfinite element software ABAQUS with a user subroutine was used to simulate the drawing of the MgB2wire. The densityand area fraction of the powder mixture during the wire-drawing process were verified with experimental results. The differencein packing density at the inner and outer filaments of the MgB2wire was successfully captured by simulation. Inaddition, the effect of the initial packing density on the superconducting properties of MgB2wire was numerically studied. It is shown that the increase in the superconducting area, which results from a high initial packing density, should be moreeffective compared to the increase in the grain connectivity in enhancing the critical current properties for the MgB2wirewhen the final packing density is saturated after a number of drawing processes.

자발성 뇌교출혈 환자의 예후에 관한 임상 분석

조재영,석종식,민병국,권정택,최덕영,황성남,김영백,박승원 중앙대학교 의과대학 의과학연구소 2002 中央醫大誌 Vol.27 No.1

Patients with spontaneous pontine hemorrhage very often develop setvere disturbances of consciousness,pupilary abnormalities, respiratory and motor. They have high mortality rate. Therefore, I analyzed the correlation between the Glasgow outcome scale(GOS)and clincial manifestations or computed tomographic(CT)findings in 48 patients with spontaneous pontine hemorrhage to clarify factors predicting the prognosis. I examined 48 Patients with spontaneous pontine hemorrhage; 33 males and 15 females, age 54.6±8.99(mean±S.D.;range 39 to 68)brought to our hospital between January 1995 and December 1999, retrospectively. Correlations between the clinical manifestations, CT findings and the GOS was assessed with multivariate regression analysis. The results were as follow: 1) Patients with the pontine hemorrhage were of 8.8% in those with intracerebral hemorrhage. The ratio of male and female was 33 to 15. The incidence of age is eqial to 40,50 and 60. Total mortality was 41.6%. 2) The poor prognostic factor were that; Glasgow coma scale(GCS)3∼8, irregular respiration. pupilary abnormality, quadriplegia, Brain CT typeⅠ(massive), hydrocephalus, extrapontine extension, Intraventricular hemorrhage(IVH). These clinical analysis should be useful in determining the level of care and future resuscitative efforts.

급성신부전을 동반한 알콜성 횡문근융해증 2례

김영민,오동렬,이원재,김형국,황두영,이환,최경호,정시경,김세경,김영옥 大韓應急醫學會 1998 대한응급의학회지 Vol.9 No.4

Rhabdomyolysis is a biochemical and clinical syndrome caused by lysis of skeletal muscle cell and release of muscle cell contents into the circulation. In addition to traumatic cause, various nontraumatic causes have been reported. Rhabdomyolysis has frequently been associated with seamy aspects of life and society: alcoholic abuse, drug addiction, sadistic drill exercise, war events and attempted suicide. The abuse of alcohol causes many hazards in many organs. One of these is acute alcoholic myopathy that may present as a fulminent syndrome of muscle pain and tenderness associated with rhabdomyolysis and acute renal failure. Because the prognosis of adequately treated rhabdomyolysis is excellent, early recognition and prompt management are essential in emergency situation. We experienced two typical cases of alcohol-induced rhabdomyolysis with acute renal failure and report these cases with literature review.

종교와 선교, 그리고 문화

권영국 국제기독교언어문화연구원 1999 기독교언어문화논집 Vol.3 No.-

Dr. Young Kook Kwon. 1999. Religion, Christian Mission, and Culture- Collected Papers on Christian Language Culture. Religion exists in the midst of human life. It is not something that is unrelated to man's practical life context and seeks something beyond. Human religions should not be taken a part alone from reality of human life to be understood correctly of their meanings and functions in human society. Human being is a culture bound existence. Culture is a way of living of human being that guides and determines human life. Within a particular life situation each society has developed its own way of living that fits best to their living context. Culture includes whole aspect of human life and provides various means of life. Not only the visible material culture but also the invisible social and ideal culture is included in the concept of culture that signifies the ways of living Because of this reason, gospel mission can not neglect the culture of the very society to which the church carries the gospel. Gospel is carried not into a cultural vaccum but into a particular life structure that has been built, used and modified for a long period of history by the people of particular culture. It has to be pointed out clearly that man's external ways of living and internal value, social structure, ethics, worldview, religious tendency, etc. are all geared by their own culture. Eventhough we are not to assume blindly the culture-determinism, its overwhelming influence in human life can never be over emphasized particularly in the area gospel mission. (Paster of An-sung the First Church)

수술 결함과 연관된 의인성 대퇴 전자 하부 골절 - 2예 보고 -

정국진 ( Kook Jin Chung ),전준영 ( June Young Jeon ),나현우 ( Hyun Woo Na ),황지효 ( Ji Hyo Hwang ) 대한골절학회 2015 대한골절학회지 Vol.28 No.4

Iatrogenic fracture is not popular and might be recognized as a malpractice. Surgical error related to iatrogenic fracture which has occurred after an operation can be detected only by a surgeon. Stress riser fracture is another form of iatrogenic fracture also known as a Young’s modulus fracture. As the majority of surgical related stress riser fractures can be preventive, the accurate prevalence is not known. The majority of fractures occurred in the weight bearing bones such as femur and tibia. The subtrochanter area is the most stress concentrated area in the human body, thus it is a common area for occurrence of stress riser iatrogenic fractures. We experienced 2 cases of stress riser iatrogenic fractures, which are related to technical errors, thus we report cases with literature review.

성인의 장중첩증에서 복부전산화단층촬영술의 유용성

김세웅,조영업,고영배,김원곤,김경국,김경래,우제홍,김미영 대한대장항문학회 1998 Annals of Coloproctolgy Vol.14 No.3

흡연자와 비흡연자의 타액에서 코티닌 정량 및 ETS 노출량 평가

임흥빈,강영국,손형옥,이영구,문자영,이동욱 충북대학교 엽연초연구소 2001 煙草硏究 Vol.18 No.-

This study was conducted to measure and compare the salivary cotinine concentration between smokers and nonsmokers, and to investigate the effect on the exposure to environmental tobacco smoke(ETS) with housewives, living on an apartment of Korea. Saliva samples were taken from all volunteers and salivary cotinine was analyzed by a developed radioimmunoassay(RIA) method. The median salivary cotinine levels were 52.8±12.6 ng/ml and 44.6± 9.7 ng/ml in male smokers and in female ones, respectively, and they were 4.3±2.1 ng/ml and 2.9±3.1 ng/ml in male nonsmokers and in female ones, respectively. In addition, average salivary cotinine levels were 3.8±2.7 ng/ml in housewives from smoking homes and 2.4±2.4ng/ml in ones from nonsmoking homes. Results obtained from the analysis of salivary cotinine demonstrate that smokers had a significantly higher concentration of salivary cotinine than nonsmoker. But, there was no significant difference in the salivary cotinine concentration for housewives living in apartment between with smoking husband and with nonsmoking husband.

신생아에 심한 심부전증을 일으킨 선천성 뇌동정맥 기형: 풍선 색전 요법을 시도한 1례

박인숙,김영휘,홍창의,조영국,서대철,박영일 울산대학교 의과대학 1993 울산의대학술지 Vol.2 No.2

Cerebral arteriovenous malformation is a rare cause of congestive heart failure in neonates and is known to carry a very poor prognosis even wish prompt recognition and aggressive treatment. We recently encountered a 2-day-old male neonate with huge cerebral arteriovenous malformation who presented with intractable heart failure. Despite aggressive medical treatment and partial embolization with detachable balloon, baby died of severe hearts failure. Since there is no report of percutaneous balloon embolization in a neonate with this lesion in Korean literature, we wish to present our experience in one such neonate. Also we believe this is the first report of color Doppler findings in cerebral arteriovenous malformation in Korean literature.