염수분무 환경에서 알루미늄-크롬 용융도금강판의 부식생성물이 내식성에 미치는 영향

임병문,홍승현,정재인,최장현,정원섭 대한금속재료학회 2003 대한금속·재료학회지 Vol.41 No.10

The effect of corrosion products of hot-dip Al-Cr steel sheet on the corrosion resistance were investigated. The results of XRD and XPS measurements showed that there was not found a hydroxide type corrosion product on the surface of aluminized steel after salt spray test(SST) but there was found some cracks in the surface layer which accelerates corrosion during SST. In Al-Cr coated steel case, the main phase of the corrosion products after salt spray test was found to be Al(OH)₃. The polalization curves of aluminized steel after SST shows that there was no passivation layer. For the Al coated layer, a porosity in the Al-oxide film on the surface layer leads to preferential corrosion. After the Al coated layer was completely removed, the Al_(5)Fe₂layer was selectively corroded and then, the steel substrate was exposed to the electrolyte. However, the polalization curves of Al-Cr coated steel after SST shows that the passivation layer was formed, which could increase the corrosion resistance of Al-Cr coated steel. In case of the Al-Cr coated layer, the densely covered hydroxide layer of Al(OH)₃and the intermetallic compound layer of Al_(13)Cr₂became a barrier against further corrosion after the Al layer was removed. In this case, corrosion was not proceeded even through the same current density. The densely covered hydroxide of Al(OH)₃and the intermetallic compound layer of Al_(13)Cr₂were considered to be one of the reasons of high corrosion resistance for Al-Cr coating.

高溫에서 疲損勞傷이 Stainless Steel의 破壞靭性에 미치는 影響에 關한 硏究

鄭世喜,林載奎,李宗基 전북대학교 1982 論文集 Vol.24 No.-

The latest industrial machinery is usually used under the severe conditions such as high temperature, high pressure and high load because it needs the best efficiency. The austenitic stainless steels(SUS 316) are well suited for high temperature and high pressure service because of their creep resistance and high ductility. In this paper, in order to investigate the variation of fracture toughness of the specimens given repeat stress at 450℃, decreasing temperture of ductility, instrumented charpy impact test was carried out from-150℃ to 100℃. The results are summerized as follows ; 1. The fatigue life at 450℃ is reduced by 70 percent than that at room temperature. 2. When the specimens are damaged by the fatigue at 35kg/㎟ and at cyclic numbers with the same ratio on N_f, the difference between 450℃ and room temperature in hardness increasing ratio is 7%, and 5% at 30kg/㎟ 3. The maximum distance of work hardened zone by the fatigue damage at room temperature is larger than at 450℃. It means that the plastic deformation occurs easily because the yielding stress is lower at room temperature than at 450℃. 4. The fracture energy(E_f) decreases with the increase of nominal stress and rate of damage.

기무라씨병의 치험례 -2례 증례보고-

임재호,최재원,김우경,정전은 大韓成形外科學會 1990 Archives of Plastic Surgery Vol.17 No.5

Kimura's diseas is a distinct clinico-pathologic entity characterized by proliferation of vascular endothelial cells and lymphoid hyperplasia with florid germinal centers associated with lymphocytic, histiocytic and eosinopholic infiltration. Two cases of Kimura's disease are presented. The first was 53 year-old female patient who had a slow growing mass on right parotid area. The second case was a 25 year-old female patient with two irregular growing masses on both submandibular region. Both cases had markedly increased peripheral eosinophilia with 34% in first case and 31% in second case. The first was treated by superficial parotidectomy and the second by direct surgical excision of masses. The specimens were confirmed ad Kimura's disease on histopathologic examination and the two cases are presented with the review of literature.

Pre-strain狀態에서의 熔接後熱處理가 構造用鋼熔接熱影響部의 破壞靭性에 미치는 影響

林載奎,鄭世喜 全北大學校 1982 論文集 Vol.24 No.-

In order to study the change of fracture toughness owing to post weld heat treatment of welded specimens under the elastic bending deformation, after post weld heat treating of four different conditions, that holding time is 0, 1/4hr, 1hr and 10hr, on the welding joint of the high strength steel with bead on plate, tested the low temperature fracture toughness, observed the microstructure and measurred the microhardness. We obtained the results as follows. 1. Fracture toughness depends upon the heat treatment conditions. 2. Fracture toughness of the specimen under the pre-strain remarkablly increased until the holding time of the heat treatment is one hour, but it was almost saturated over the one hour. 3. Tempering the welding HAZ with the maximum (H_v=250), it became soft to H_v=170, but tempering under the elastic straining (ε=0.024), increased the hardness to the H_v=210. 4. Tempering at the condition of the elastic strain on the HAZ structure, fracture toughness greatly depends upon the hot working deformation.

畵夜間 溫度差(DIF)處理에 의한 고추 '녹광' 플러그苗의 生長反應

임기병,오중열,정재동 慶北大學校農業科學技術硏究所 1996 慶北大農學誌 Vol.14 No.-

고추 '녹광' 품종의 플러그 육묘시 주야간 온도차 처리에 따른 생육조사 결과 초장은 주간온도와 DIF에 의해 영향을 받으며 절간장도 초장과 비슷한 경향이었다. 엽전개속도는 주로 일 평균 온도에 의해 좌우되었다. 엽장, 엽폭은 일 평균 온도가 증가함에 따라 증가 하는 것으로 나타났으며 생체중은 주야간 온도가 15℃처리구에서 가장 낮았고 일평균 온도가 증가함에 따라 증가하는 경향이었다. 생체중과는 반대로 엽록소함량은 일평균 온도가 15℃처리구에서 가장 높게 나타났으며 전체적으로는 야간온도가 증가할수록 엽록소함량이 저하되었다. 줄기직경은 DT/NT=15/15처리구에서 가장 낮았고 다른 처리구는 비슷한 경향이었다. T/R율은 DT/NT=30/15℃(+15DIF)처리구에서 가장 높게 나타나 지상부가 지하부에 비해 과번무됨을 알수 있었다. 따라서 녹광 고추의 플러그 육묘시 충실한 묘를 생산하기 위해서는 주간온도가 22.5℃, 야간온도는 15-22.5℃범위의 0DIF또는 약한 +DIF조건에서 육묘하는 것이 강건한 묘생산에 유리할 것으로 판단된다. Capsicum annuum 'Nokkwang' plug seedlings were treated with 9 different day and night temperatures to investigate on growth and differentiation in controlled environment conditions. The plant height was the most affected by day temperature and DIF and stem length was the similler results as plant height. However, Leaf unfolding rate and leaf length and width increased as average daily temperature increased. and especially fresh weight was worst at ADT was 15℃ and increased as ADT increased. In contrast with fresh weight, chlorophyll content calculated highest when ADT was 15℃, and decreased as NT increased respectively. The stem lengths were not significantly different among treatments with exception of DT/NT=15/15℃ which significantly decreased. The ultimate +DIF condition, DT/NT=30/15℃, caused high T/R ratio due to abundant top growth. It is concluded that DT is 22.5℃, caused high T/R ratio due to abundant top growth. It is concluded that DT is 22.5℃, and NT is ranged from 15℃ to 22.5℃ to be produced short, healthy plug seedlings in Capsicumannuum 'Nokkwang'.

鋼 熔着金屬의 熱變形脆化에 關한 硏究

鄭世喜,金台永,林載奎,鄭熙敦,朴昌彦 全北大學校 1984 論文集 Vol.26 No.-

The susceptibility of weld metal(AWS, F76-EH14) on hot straining embrittlement has been examined. The sharp notch was machined on the weld metal of 1st bead and on coarse-grained HAZ transformed by next pass. After machining the notch, these specimens were bended at 250℃ to receive the hot straining embrittlement and they were done COD fracture toughness test by the three point bending, and then the change of plastic zone at notch tip was evaluated by microhardness test. The obtained results are summarized as follows. 1. Fracture toughness of weld metal was greater than that of base metal. 2. Fracture toughness of the coarse-grained HAZ was similar to that of weld metal. 3. Hardness of weld metal reheated by next pass was lower than that of weld metal owing to the effect of heat treatment. 4. Plastic deformation of the coarse-grained HAZ was less than that of weld metal.

Protein Methylase Ⅱ에 依한 Carboxylmethylation이 胎盤組織 Na^+, K^+―ATPase 活性에 미치는 影響

鄭顯,林圭,黃炳斗,李載欣 충남대학교 의과대학 지역사회의학연구소 1987 충남의대잡지 Vol.14 No.2

Partial purified human placental Na+, K+-ATPase and plasma membrane proteins were enzymically carboxylmethylated by human placental protein methylase II, and changes in their Na^+, K^+-ATPase acivities were studied. 1.. The rates of enzymatic carboxylmethylation by protein methylase II of the placental Na^+, K^+-ATPase fraction, which had been purified 19-fold, and of the plasma membrane proteins were 0.71 and 0.50 pmoles/mg protein/minute, respectively, when measured by the incorporation of ^3H-methyl group from S-adenosylmethionine into the proteins. 2. The enzymatic carboxylmethylation was found to be a function of the concentration of S-adenosylmethionine as well as of the substrates and incubation time. 3. More than 60% of the carboxylmethylated Na^+, K^+-ATPase fraction and plasma membranes were demethylated during 30 minutes incubation at pH 7.4, with the demethylation half time of 15 and 8 minutes, respectively. 4. The placental Na^+, K^+-ATPase fraction and plasma membrane proteins were found to be better substrates for protein methylase II than histone IIA. 5. Polyacrylamide gel electrophoresis of the carboxylmethylated plasma membrane proteins and Na^+, K^+-ATPase fraction showed multiple carboxylmethylated subfractions: in the plasma membrane, subfractions of molecular weight 95000, 43,000, 26,000 and less than 20,000, among which molecular weight 26,000 fraction was most strongly carboxylmethylated, and in the Na^+, K^+-ATPase fraction, subfractions of molecular weight 50,000, 40,000, 26,000, and less than 20,000 were carboxylmethylated. 6. Na^+, K^+-ATPase activities of the plasma membrane and the Na^+, K^+-ATPase fraction were increased by 36% and 9% when carboxylmethylated, and decreased by 25% and 21% after cAMP-dependent phosphorylation, respectively. These results suggest that protein merhylase II may have some indirect role in the regulation of Na+, K+-ATPase activity.

알루미늄-크롬 용융도금강판의 미세조직과 집합조직에 미치는 크롬의 영향

임병문,홍승현,정재인,최장현,정원섭 대한금속재료학회 2003 대한금속·재료학회지 Vol.41 No.10

Microstructure and texture changes of aluminized coatings on steel sheets having Cr ranging from 0.0% to 1.0% in the coated layer were investigated. The surface morphology of the Al-Cr coated steel is not influenced by the increase of Cr contents in the coated layer. While the coated layer of aluminized steel consisted of two phases of Al and Al_(5)Fe₂, the aluminized coating layer containing Cr was composed of three phases of Al, Al_(13)Cr₂, and Al_(13)Fe₄+Al_(5)Fe₂. The surface layer was Al, the middle layer was Al_(13)Cr₂, and the interfacial layer between the coating and the steel substrate was Al_(13)Fe₄and Al_(5)Fe₂. The texture of the aluminized coating without Cr was characterized as a {001} fiber texture which major orientation was {001}<110>. As the Cr content in the aluminized layer was increased to 1.0%, the texture of the aluminized coating was not changed but the intensity of the {001} fiber texture was increased. The major orientation in the {001} fiber texture was changed from the rotated cube orientation of the aluminized coating with 0.1%Cr to the cube orientation of the aluminized coating with 1.0%Cr.

수중운동 프로그램이 뇌성마비아의 체력에 미치는 영향

정재권,임석주 한국특수교육문제연구소 2002 특수교육저널 : 이론과 실천 Vol.3 No.3

본 연구는 수중운동 프로그램이 뇌성마비아들의 체력에 미치는 영향을 살펴보고자 뇌성마비학생 5명에게 12주 동안 수중운동 프로그램윤 적용하여 뇌성마비학생들의 근력,근 지구력,유연성,민첩성,평형성 등의 변인들을 측정 분석한 결과 근력인 악력,근 지구력인 윗몸 일으키기,민첩성인 왕복달리기,유연성인 체전굴,평형성인 한발로 서기에 긍정적인 변화가 있었다. 이상과 같은 연구 결과를 동하여 볼 때 수중운동은 체력 요인에 긍정적인 영향을 미쳐 체력 향상 및 건강증진에 많은 도움이 될 것으로 사료된다. The purpose of this study were to evaluate the effect of aquatic exercise on body composition, pulmonary function and physical fitness. The subjects for this study were five spasticity cerebral palsy(18 - 20 years). The aquatic exercise program consisted of 11 item, and performed for 30-40mins in a bout, 3 times a week at the intensity of HRmax(40-65%) for 12 weeks. And the change of body weight, %fat, fat mass, vital capacity, hand grip, sit-ups, trunk flexion, closed eyes foot balance and shuttle-run have been measured in baseline, post 4, 8 and 12 weeks respectively. The following results were obtained from this study. Hand grip(2-4kg), sit-ups(5-8 bouts), trunk flexion (1 -4cm) and closed eyes foot balance(O.25-2.43sec) were increased after individually aquatic exercise for 12 weeks respectively. And, shuttle-run(O.37 - 0.9secl was decreased after aquatic exercise. These results suggest that aqustic exercise for 12 weeks affects on body composition, pulmonary function and physical fitness to the spasticity cerebral palsy. On the other hand, long term regular aquatic exercise programs are applicable to the spasticity cerebral palsy with abnormal movement in safety through the re-composition of exercise intensity and mode.

Cr-Mo鋼 鎔接熱影響部의 鏞接後熱處理에 關한 硏究

林載奎,鄭世喜 全北大學校 1985 論文集 Vol.27 No.-

Post weld heat treatment(PWHT) of weldment of the low alloy steel, in general, is carried out not only to remove residual stress and hydrogen existing in weldment but to improve fracture toughness of weld HAZ. There occur some problems when PWHT is practiced. They are toughness drecrement and stress relief cracking(SRC), which especially exist in the coarse-grained region of weld HAZ taken the effect of tempering treatment because PWHT is conducted at high temperature more than 600℃. Therefore, in this study, the effect of heating rate during PWHT on fracture toughness under the various kinds of stresses simulated residual stress in weld HAZ of Cr-Mo steel were evaluated by crack opening displacement(COD) test and microhardness test. The experimental results are as follows; 1. Fracture toughness of weld HAZ was improved by PWHT, but it decreased as heat treated under the stress. 2. Fracture toughness of weld HAZ was dependant upon heating rate during PWHT. In case of no stress, it was decreased with increment of heating rate, but it was improved with increment of heating rate in case of stress. 3. The difference of transition temperature, (ΔT_tr)_(σ=0), was linearly changed to hardness ratio, Hv/(Hv)_(σ=0), due to the varity of heating rate. And fracture toughness was increased with decrement of hardness ratio at the heating rate of 600℃/hr and 220℃/hr, but it was the reverse at 60℃/hr.