Misorientation Characteristics at the Growth Front of Abnormally-Growing Goss Grains in Fe–3%Si Steel

Tae‑Young Kim,Tae‑Wook Na,Hyung‑Seok Shim,Yong‑Keun Ahn,Yong‑Kwon Jeong,Heung Nam Han,Nong‑Moon Hwang 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.12

Penetrating morphologies at the growth front of abnormally-growing Goss grains in Fe–3%Si steel was examined in view ofthe possibility that they are the two-dimensional section of the solid-state wetting (SSW) along the triple junction line. Toobtain the statistically meaningful data, 102 penetrated grain and 204 penetrating abnormally-growing Goss grain morphologieswere examined. The misorientation angles of penetrating and penetrated grains were measured by electron backscattereddiffraction. Among the 102 examined penetrated grain boundaries, none has low misorientation angles less than 15°,whereas 17.2% of the 204 penetrating grain boundaries have low misorientation angles, and 23.5% of them have coincidencesite lattice boundaries. Besides, boundary energies of penetrating Goss grains, which were estimated from misorientationangles of the three grains in the penetrating morphology, satisfied the energetic condition for SSW along the triple junctionline. These results imply that the abnormal grain growth of Goss grains in Fe–3%Si steel occurs by the mechanism of subboundaryenhanced SSW.

한국인 관상동맥의 변화양상에 대한 형태학적 연구

권태정,이상용,이한영,고영창,권기석,조재홍,김태공,김유훈,조갑래,서중석,이원태 內務部 國立科學搜査硏究所 2001 國立 科學 搜査 硏究所 年報 Vol.33 No.-

Stented Graft의 임상경험

권태원,김호성,김도균,성규보,조용필,김건언 대한혈관외과학회 2000 Vascular Specialist International Vol.16 No.2

Purpose: Endovascular repair is a alternative treatment with favorable short-term result, but long term results are not available compared to standard operation. The authors have reviewed experiences of Asan Medical Center on stented graft, performed from Aug. 1998 to Feb. 2000, and the results as to age, operative indication, clinical condition, anatomic location, complication, follow-up are reported. Method: Seven patients who has received stented graft between Aug. 1998 and Feb. 2000 are reviewed retrospectively. Result: Of the seven patients, 6 were male and 1 was female. The mean age was 46.4 years (17~71). Indication for stented graft were two pseudoaneurysms, two iatrogenic arterio-venous fistulas, one thoracic aorta aneurysm, one abdominal aortic aneurysm, and one iliac artery occlusion with blue toe syndrome. Three different types of stented graft devices were utilized: Dacron-covered nitinol stented graft (made by the Asan Medical Center medical device team), Vanguard II (by Boston Scientific Corp.), and PTFE with nitinol stented graft (by Tae-woong). There was no perioperative mortality, and the technical success was achieved in five cases (71%). The patency at 14-month were 1009o (5/5). Two immediate complications are hemorrhage due to iliac & femoral artery avulsion requiring emergency bypass grafting, and deployment failure of stented graft requiring removal of retained graft device. Conclusion: Stented graft may be utilized even in complicated vascular situation but will need further development of device and more experience to prevent possible catastrophic complication. Indication should be decided by team approach and vascular surgeon should be prevent or participate during the procedure.

단백뇨를 보이는 사구체 질환 및 당뇨병성 신병증에서의 Lp(a)

권태환,김준홍,조성,김석재,김용림,조동규,백미영 경북대학교 병원 1998 경북대학교병원의학연구소논문집 Vol.2 No.1

Background: Recently there has been evidences that serum Lp(a), an independent risk factor to atherosclerotic cardiovascular diseases, were increased in proteinuric disorders such as nephrotic syndrome and diabetic nephropathy. Methods: We intended to search of altered concentrations of Lp(a) in proteinuric disorder measuring serum Lp(a) concentrations with ELISA in 44 glomerulonephritic patients(25 nephrotic syndrome(NS), 19 non-nephrotic range proteinuric glomerulonephritis(GN), 25 diabetic nephropathy patients(DN), and 31 healthy controls(HC). Also, we compared Lp(a) concentration between glomerulonephritis patients and diabetic nephropathy patients with proteinuria of similar degree. Results: 1) There were significantly increased levels of total choesterol, triglyceride, and LDL-cholesterol in Ns compared to GN, DN, HC. 2) There were significantly increased concentrations of serum Lp(a) in NS compared to HC, but no signiicant difference in serum Lp(a) among NS, GN, and DN. 3) There was no significant difference in serum Lp(a) concentrations between NS & DN with 24 hour urine protein greater than 3.0g. 4) There was no significant difference in serum Lp(a) concentration between GN with 24 hour urine protein greater than 0.5g and less than 1.5g and DN with proteinuria of simial degree. 5) In glomerulonephritis patients, there was negative correlation between serum Lp(a) concentration and serum albumin level but correlation with 24 hour urinary protein, total cholesterol, Ldl-cholesterol, and HDL-cholesterol was not shown. In diabetic nephropathy, there was no significant correlation among serum Lp(a) concentration and all parameters including serum albumin, 24 hour urinary protein, and other lipid profiles. Conclusion: The present study confirmed that patients with nephrotic syndrome of diverse etiologies have makedly increased plasma level of Lp(a), in conjunction with other lipid abnormalities. However, this study shows no difference in Lp(a) concentrations between diabetic nephropathy and glomerulonephritis with similar degree of proteinuria.

공급사슬관리에서의 최적 생산·수송에 관한 연구

권수태,엄용호 전주대학교 공학기술종합연구소 2003 전주대학교 공학기술종합연구소 학술논문집 Vol.9 No.1

Recently, many company endeavor to gain competitive advantage so as quickly to satisfy customer demand and effectively reduce operating costs. An approach is to integrate supply chain which is the link that moves products between suppliers, manufactures, wholesalers, distributions, retailers and ended consumers. This paper is concerned with the integrated production planning problem including not only the production cost but also the transportation cost in supply chains, and an efficient algorithm using genetic algorithm and quickest path method is exploited to solve the problem.

各種 喀痰消化劑가 抗酸菌死滅에 미치는 影響

權智順,權五溶,崔大卿,白太鉉 충남대학교 의과대학 지역사회의학연구소 1985 충남의대잡지 Vol.12 No.1

For the isolation of mycobacteria in sputum specimens, it is essential to use the most gentle procedure of digestion system for the survival of organisms. The present studies were undertaken to evaluate and compare the effect of various sputum digestants on the death of Mycobacterium fortuitum and Mycobacterium tuberculosis. The results were summarized as follows: 1. Death rates of M. tuberculosis in a solution of 2% NaOH, 3% NaOH and 4% NaOH digestants after 30 minutes of contact time were 97.1%, 97.6% and 97.9%, respectively. In the digestants of 2% NaOH, 3% NaOH and 4% NaOH solution after 1 hour of contact time, survival rates were less than 2%. 2. Death rates of M. tuberculosis in Zephiran-N-acetyl-L-cysteine digestant after 30 and 60 minutes of contact time were 28.5% and 39.5%, while those of M. fortuitum after the contact time were 74.1% and 81.2%, respectively. 3. Death rates of M. tuberculosis in Zephiran-trisodium phosphate digestant after 30 and 60 minutes of contact time were 36.1% and 40.3%, and those of M. fortuitum after the contact time were 71.6% and 74.2%, respectively. 4. Death rates of M. tuberculosis and M. fortuitum in N-acetyl-L-cysteine-NaOH (2%) digestant were similar to the digestant of 2% NaOH solution.

브레이징법에 의한 TiA1 금속간 화합물의 접합에 관한 연구

권영순,권용재,김지순,김환태 울산대학교 1995 공학연구논문집 Vol.26 No.2

본 연구에서는 Al을 삽입금속으로 사용하여 브레이징법으로 접합한 TiAl 금속간화�물의 접합특성에 대하여 조사하였다. 삽입금속인 Al과 모재인 TiAl과의 반응에 의해 접합계면에서는 반응생성층으로서 경도가 모재보다 높고 취약한 TiAl₃가 형성되었으며, 접합온도가 600℃로 낮았거나 가열속도가 30K/min으로 너무 빠를 경우에는 반응생성층내에 void와 미소균열과 같은 접합결함이 존재하였다. 이와 같은 접합결함들은 700℃보다 높은 온도에서 접합하거나 가열속도를 10K/min보다 낮게 하여 접합한 경우에는 나타나지 않았다. 한편 접합체의 기계적 성질의 향상을 위하여 접합 후 Ar가스 분위기에서 열처리를 행한결과, 1300℃에서 3시간 동안 열처리를 했을 경우 모재와의 조성의 균일화가 완전히 이루어지지 않았으며 또한 반응생성층의 형태도 변화가 없었다. 그러나 1350℃에서 3시간 동안 열처리한 결과 조성의 균일화와 함께 반응생성층은 ??단상으로 변하였으며, 반응생성층의 미소경도는 층상조직인 모재의 미소경도보다 조금 낮게 나타났다. In this study, Joining properties of TiAl intermetallic compound bonded by brazing method using an insert metal of Al foil were investigated. A brittle reaction product layer. TiAl₃was formed at the joining interface and its microhardness was very higher than that of base metal. When the specimen was bonded at low temperature of 600℃ or with high heating rate of 30K/min respectively, joining defects like void and micro-crack were formed in the in the inside of reaction layer. These joining defects were disapeared when the speciment had been bonded at higher temperature than 700℃ or with lower heating rate than 10K/min. For the purpose of improving the mechanical properties of joints, effects of the post-bond heat treatment in Ar gas atmosphere on microstructure and hardness distribution of the bonded speciment were studied. When the joint was geat-treated at 1300℃ for 3 hr, homogenization of the compositions in the joining interface region was not achieved completely and morpholgy of the reaction product layer was still remained without morphological change. However, when the joint was heat-treated at 1350℃ for 3 hr, homogenization of the compositions in the joining interface region was achieved and the reaction product layer changed to γ single phase. And micro-vickers hardness of reaction layer region was slightly lower than that of base metal.

Film중감지와 Film의 활용에 따른 화질특성의 고찰

권용재,이상모,김순희,김도형,최태균 한국건강관리협회 2000 건협 Report Vol.3 No.-

상아질 접착제의 적용이 법랑질 접착에 미치는 영향

권태엽,권용훈,김교한,송근배 大韓齒科器材學會 2003 대한치과재료학회지 Vol.30 No.2

The objective of this study was to evaluate the effect of various enamel surface treatments on the bond strength of a composite resin to enamel (n=15). Ground bovine enamel specimens were divided into seven groups. A composite resin (Z250. 3M) was bonded to the specimens using different enamel surface treatments. Four groups examined the effect of application of all-in-one adhesives (Prompt L-Pop (POP), One-Up Bond F (ONE)) with respect to static priming (SP) or dynamic priming (DP). The other two examined use of the POP and ONE after phosphoric acid etching (PE). And the control group provided bond strength of the composite resin to phosphoric acid etched enamel with a resin bonding system (Single bond, SB, 3M). Shear bond strengths for the specimens were measured after 24 hours storage in water at 37 ℃. Effects of various surface treatments on enamel were examined by SEM. Dynamic priming resulted in higher enamel bond strengths than static priming and the best bond strengths were obtained when the enamel was etched with phosphoric acid. SEM analysis showed that depth of etching was related to the bond strengths measured. The enamel etch pattern after static priming showed little retentive surfaces. After dynamic priming, the enamel rod structure has become apparent in the shallow etch. SEM view showed that the resin tags and resin penetration were related to the bond strengths measured. SEM showed minimal resin penetration into enamel following static priming. After application of adhesives to phosphoric acid etched enamel, SEM showed more extended tags that are reflective of the deeper etch pattern.

CAD를 이용한 양수장 및 배수장설비 설계의 표준화

권병철,권경우,김기길,명태식,박찬호,박귀용 한밭대학교 산업과학기술연구소 1995 논문집 Vol.3 No.-

This paper is to be illustrated automation in the design of Pumping Station and Draining Station. Program for design automation applying Auto LISP, DCL can be used to design and draw simultaneously. The study result are as follows. 1. Optimal design has been introduced and precise design has been possible using CAD. 2. Dialog design is possible with introduction the concept of design automation, and design cost can be reduced greatly.