http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Dong Hyo Joung (검색결과 129 건)
- 무료
- 기관 내 무료
- 유료
-
(AgCu)_0.43-Au_0.54Pd_0.03 합금의 시효경화 특성
배동화,설효정,이희경,김형일,김교한 대한치과기재학회 2001 대한치과재료학회지 Vol.28 No.3
팔라디움이 함유된, 시효경화성 치과주조용 고금합금의 연구를 위한 기초자료를 얻기 위하여, 4원계 □ 합금의 등온시효경화 거동과 상변태를 경도 시험, X선회절 실험으로 조사하여, 다음과 같은 결과를 얻었다. 본 합금을 250~350℃에서 등온시효처리하면, 면심정방구조를 갖는 준안정상 AuCu Ⅰ'형 규칙상이 면심정방구조를 갖는 AuCu Ⅰ형 규칙상과 면심입방구조를 갖는 Ag-rich a₁상이 생성되기 전에 생성되었다. 본 합금은 시효처리 온도에 따라 다른 시효경화 거동을 보여주었다. 350℃에서 시효처리를 하면, 경도는 시효 초기에 상승하지 않았고, 최고 경도에 도달하여 유지되고나서 시효시간을 연장함에 따라 경도가 급격히 저하하였다. 250℃에서 시효처리를 하면, 경도는 시효 초기부터 뚜렷히 상승하기 시작하였다. 그 후, 약간의 경도 하강을 보이고나서 경도는 다시 서서히 상승을 지속하였다. 350℃에서 경화는 준안정상 AuCu Ⅰ'형 규칙상의 균일핵생성에 기인하였다. 낮은 시효온도에서의 초기 경화는 다른 상변태에 의해 초래되었고, 이어서 일어나는 경화는 준안정상 AuCu Ⅰ'형 규칙상의 생성에 기인하였다. 시효시간을 연장함에 따라 생기는 과시효 연화는 평형상 AuCu Ⅰ형 규칙상의 생성에 기인하는 것으로 생각된다.
-
배동화,설효정,이희경,김형일 대한치과기재학회 1999 대한치과재료학회지 Vol.26 No.1
The hardening behavior and phase transformation process of a dental high carat gold alloy by isothermal ageing treatment were investigated by means of hardness testing, X-ray diffraction study and scanning electron microscopic observations. The following results were obtained. The a single phase with a face centered cubic structure was finally transformed into the coexistence of the Ag-rich α₁phase with a face centered cubic structure and the AuCu I' type ordered phase with a face centered tetragonal superlattice structure by ageing of the solution-treated specimen at 400℃ and 500℃. By ageing at 500℃, the metastable Ag-rich α₁' and AuCu I' type ordered phases were formed prior to the final formation of the equilibrium Ag-rich α₁ and AuCu I type ordered phases . The hardening effect was more significant and the overageing with softening was slower by ageing at 400℃ than 500℃. By ageing at 500℃, the hardening was attributed to the formation of the metastable AuCu I' type ordered phases from the a phase, the overageing with softening was due to the formation of the AuCu I type ordered phase from the metastable Ag-rich α₁' and AuCu I' type ordered phases. By ageing at 500℃, the incubation period which limited the beginning of the hardening in the early stage of ageing existed, and the formation and growth of the precipitates which contributed the overageing with softening were observed concurrently at the grain boundaries and within grains. By ageing at 400℃, the hardening was attributed to the formation of the AuCu I type ordered phase from the a phase, the overageing with softening was due to the growth of the grain boundary precipitates of the lamellar structure composed of the Ag-rich α₁and AuCu I type ordered phases into the grain interior.
-
Temperature changes and compressive properties of bulk-fill composites by light curing
Dong-ho Yi(이동호),Hyo-Joung Seol(설효정),Yong Hoon Kwon(권용훈) 대한치과재료학회 2020 대한치과재료학회지 Vol.47 No.4
The purpose of the present study was to assess the temperature change and compressive property of bulk-fill composites (BFCs) by the light curing. Seven resin-based composites (RBCs), including five BFCs, were chosen to evaluate their maximum temperature rise and exothermic heat during and after light curing and compressive strength (CS) and modulus (CM) for 4-mm thick state. Light attenuation coefficients (ACs) showed reasonably high correlation with filler content (vol% and wt%). Except one resin product, AC values of BFCs were lower than those of RBCs tested. All the tested specimens showed temperature rise (9.8-23.6℃) and exothermic heat (4.2-18.3℃) for 4-mm thick case. CS and CM values of the tested specimens ranged approximately 69 to 116 MPa and 1.3 to 2.8 GPa, respectively. The difference of temperature changes and compressive properties (CS and CM) between BFCs and RBCs was not consistent and had no statistically consistent significance.
-
-
Age-hardening and Related Phase Transformation in a Dental Au-Cu-Ag-Pt Alloy
Dong-Hun Lee(이동훈),Sang-Hwa Lee(이상화),Mi-Hyang Cho(조미향),Hyo-Joung Seol(설효정),Yong Hoon Kwon(권용훈),Hyung-Il Kim(김형일) 대한치과재료학회 2010 대한치과재료학회지 Vol.37 No.2
조성이 중량으로 68.0 wt% Au - 15.O wt% Cu - 9.2 wt% Ag - 5.O wt% Pt - 2.0 wt% Pd인 치과용 금합금의 시효처리에 따른 상 변태와 미세조직 변화를 조사하여, 다음과 같은 결과를 얻었다. 용체화 처리된 시편을 350℃에서 시효처리함에 띠라 모상인 α? 상이 준안정상을 거쳐 2상으로 분리되었다. 상 전이의 과정은 α? → Au - Ag - rich α₁ + AuCu I’ → Au - Ag - rich α₁ + AuCu I’ + AuCu I → Au - Ag - rich α₁ + AuCu I이었다. α? 상에 Au - Ag - rich α₁ 상, 준안정상인 AuCu I’ 상 그리고 AuCu I 상으로 변태함에 띠라 경도가 뚜렷하게 상승하였다. Au-Ag-rich α₁상과 AuCu I 상으로 이루어진 층상구조는 입내의 미세한 Au - Ag - rich α₁ 상과 AuCu I 상을 소비하면서 입계에서 입내로 성장하였으며, 격자 뒤틀림을 해소하여 경도 감소에 기여하였다. 본 연구에 사용된 합금의 특성은 2상 분리된 생성상 중에서 석출상인 AuCu I 상의 생성량이 Au - Ag - rich α₁ 상의 생성량보다 많았으며, 석출물이 아주 미세하게 형성되고 층상조직의 조대화가 신속하게 일어나지 않았다.
-
-
이동근(Dong Keun Lee),김병호(Byung Ho Kim),동석호(Seok Ho Dong),김효종(Hyo Jong Kim),장영운(Young Woon Chang),이정일(Joung Il Lee),장린(Rin Chang),정경천(Kyung Cheon Jeong) 대한내과학회 2000 대한내과학회지 Vol.59 No.1
Hepatic encephalopathy is a complex neuropsychiatric syndrome with protean clinical manifestations. Recently, we experienced a atypical case of hepatic encephalopathy who chiefly complained of extrapyramidal symptoms. A 41-year-old female had a 4-year history of liver cirrhosis that was caused by hepatitis B virus. Three days before admission, she began to feel resting hand tremor, facial diplegia, dysarthria, drooling and swallowing difficulty. On physical examination, cogwheel rigidity of upper extremities, stooping posture and loss of arm swing on walk were noted, but all sensory functions were intact. MRI showed abnormally increased signal on T1-weighted images in the corpus striatum, mainly in the putamen and globus pallidus, and the head of the caudate nucleus. Her neurological and radiological findings were consistent with manganese intoxication, but she had no history of manganese exposure. The extrapyramidal symptoms and signs were successfully controlled after the administration of anti-parkinsonian drugs, but it was uncertain whether this improvement was a result of drug therapy or not. (Korean J Med 59:95-99 ,2000)
-
SV40 T 항원의 온도조건부 변이형 유전자가 포함된 Amphotropic Retrovirus 에 의한 사람 태아 간세포의 불멸화
이정일(Joung Il Lee),동석호(Seok Ho Dong),김효종(Hyo Jong Kim),김병호(Byung Ho Kim),장영운(Young Woon Chang),장린(Rin Chang),성세라(Se Ra Seong),박재경(Jae Kyung Park),김승보(Seung Bo Kim),이상목(Sang Mok Lee) 대한내과학회 1999 대한내과학회지 Vol.57 No.1
Human cells are almost never spontaneously immortalized in vitro. We tried to immortalize human fetal hepatocytes (h-FH) and evaluate the differentiational status and its change. Methods : Hepatocytes were isolated from a liver fragment of 20 week old fetus and infected with amphotropic recombinant retrovirus containing a temperature- sensitive mutant of SV40 large T antigen and neomycin phosphotransferase gene. G418 resistant colonies were cloned and expanded. The cells which were able to divide more than 30 times were used to analyze various functions. Results : The immortalization rate was 3.3 x 10-8 and two cell lines (C11, D21) were established. C11-60, C11-80, D21-30 and D21-60 (suffix number means the cell division counts) were evaluated. D21-30 was thougt to be imcompletely immortalized because a considerable portion of cells died during culture. The morphology was similar to that of epithelial cells except for D21-30 which looked like fibroblast. The cells grew rapidly at 33oC but stopped growing at 39oC. T antigen and p53 was expressed at 33oC but disappeared at 39oC, which suggest that T antigen binds to p53. Chromosomal changes were so marked that it was impossible to discriminate exact number. Albumin was secreted as about 1/10 as that of h-FH, but alpha-fetoprotein secretion stopped after immortalization. Telomerase was activated in both cell lines except for the incompletely immortalized cells D21-30. Telomere was elongated in competely immortalized cell lines, but it was rather shortened in D21-30 compared to that of h-FH. Macroscopic colonies did not develop in soft agar assay. Conclusions : We successfully immortalized human fetal hepatocytes. Although the cells are not likely to have oncogenicity, the functions are not so good, possibly due to marked chromosomal changes which are thought to occur before telomerase is activated during immortalization step.
-
-
Kim, Dong-Woo,Shim, Jae-Eun,Paik, Hee-Young,Song, Won-O,Joung, Hyo-Jee The Korean Nutrition Society 2011 Nutrition Research and Practice Vol. No.
Accurate assessment of nutrient adequacy of a population should be based on usual intake distribution of that population. This study was conducted to adjust usual nutrient intake distributions of a single 24-hour recall in 2001 Korean National Health and Nutrition Surveys (KNHNS) in order to determine the magnitude of limitations inherent to a single 24-hour recall in assessing nutrient intakes of a population. Of 9,960 individuals who provided one 24-hour recall in 2001 KNHNS, 3,976 subjects provided an additional one-day 24-hour recall in 2002 Korean National Nutrition Survey by Season (KNNSS). To adjust for usual intake distribution, we estimated within-individual variations derived from 2001 KNHNS and 2002 KNNSS using the Iowa State University method. Nutritionally at risk population was assessed in reference to the Dietary Reference Intakes for Koreans (KDRIs). The Korean Estimated Average Requirement (Korean EAR) cut-point was applied to estimate the prevalence of inadequate nutrient intakes except for iron intakes, which were assessed using the probability approach. The estimated proportions below Korean EAR for calcium, riboflavin, and iron were 73%, 41%, and 24% from usual intake distribution and 70%, 51%, and 39% from one-day intake distribution, respectively. The estimated proportion of sodium intakes over the Intake Goal of 2,000 mg/day was 100% of the population after adjustment. The energy proportion from protein was within Korean Acceptable Macronutrient Distribution Ranges (Korean AMDR), whereas that of carbohydrate was higher than the upper limit and that of fat was below the lower limit in the subjects aged 30 years or older. According to these results, the prevalence of nutritional inadequacy and excess intake is over-estimated in Korea unless usual intake distributions are adjusted for one-day intakes of most nutrients.
DBpia연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
