당뇨병유발백서에서 급성패혈증 병발시 적혈구막지질과산화의 변화

박성우,홍성관,유형준,장대영,강승식,유재명,임성희,최문기,노정우,이규만 대한당뇨병학회 1994 Diabetes and Metabolism Journal Vol.18 No.3

배양된 혈관내피세포에서 uncoupling protein 2 유전자 과발현이 세포내 산화스트레스 및 endothelin - 1 mRNA 발현에 미치는 영향

강효경,한정희,홍성관,김하영,남궁일성,박기영,박혜선,이재담,박중열,이인규,이기업 한국지질학회 2001 韓國脂質學會誌 Vol.11 No.2

Mycobacterium Avium - in tracellulare Complex 와 M . Fortuitum 에 의한 폐항산균증(肺抗酸菌症) 3예

김상재,홍수표,배길한,김성진,진병환,정충모 대한미생물학회 1982 大韓微生物學會誌 Vol.17 No.1

Two cases of pulmonary disease in a 54 year-old female and a 70 year-old male patient due to Mycobacterium avium-intracellulare complex (MAIC) and a case of pulmonary infection in a 69 year-old male patient due to M fortuitum (MF) were found recently in this institute. All three patients bad a long history of anti-tuberculous chemotherapy because they were initially diagnosed as pulmonary tuberculosis. A 70 year-old male patient infected with MAIC had an unsuccessful chemotherapy history of isoniazid (INH), para-aminosalicylic acid (PAS) and streptomycin (SM) with an incomplete, temporary, symptomatic improvement, for three years since 1964 when he was first diagnosed as pulmonary tuberculosis on physical examination. A 54 year-old female patient infected with MAIC also had an unsuccessful chemotherapy history with the various anti-tuberculous drugs since 1958. Both patients discharged large number of MAIC in their sputum specimens for at least more than one year, but no M tuberculosis at all. A 69 year-old male patient infected with MF was diagnosed as moderately advanced pulmonary tuberculsis in 1977. Combined chemotherapy with INH+PAS+pyrazinamide (PZA) improved his clinical symptoms, however, his chest radiograph was deteriorated again in 1980 one year after he stopped therapy. Therefore he started chemotherapy again with INH+ethionamide (TH)+cycloserine(CS) but no improvement was noticed. MF was cultured from his sputum in August 1983 and he continuously discharged the same baeilli until last examination of January l982. Whether all three patients were initially infected with nontuberculous mycobacteria or complicated with predisposing tuberculosis was not clear because there were no reliable bacteriological Examination records.

제 2 형 당뇨병에서 미세혈관 합병증과 대혈관 합병증의 대비

강문호,이기영,정연실,김홍규,서찬종,송광식,박혜영,이원기 대한당뇨병학회 2001 Diabetes and Metabolism Journal Vol.25 No.2

Background: Type 2 diabetes is a heterogeneous disease. As to its complications, microangiopathy predominantly develop in some patients while macroangiopathy is more predominant in others. Therefore, this study was performed to identify the factors associated with such dissociation. Methods: Type 2 diabetic patients were classified into the macro and microangiopathy groups by carotid intima-medial thickness (IMT) and the presence of severe diabetic retinopathy. Patients with IMT ≤ 0.83 mm and severe NPDR or PDR were assigned to microangiopathy group; those with IMT 0.84 mm and no diabetic retinopathy were assigned to macroangiopathy group. Of 95 patients studied, 14 were classified as microangiopathy group and 20 as macroangiopathy group. Results: When the microangiopathy and macroangiopathy groups were compared, the microangiopathy group were significantly younger at the time of examination and at the onset of diabetes, and had longer duration of diabetes. Percentage of patients receiving insulin treatment was significantly higher and plasma C-peptide significantly lower in the microangiopathy group. However, HDL-cholesterol levels were significantly lower in the macroangiopathy group. Furthermore, the multiple logistic regression analyses revealed that younger onset of type 2 diabetes was an independent factor that was associated with the acceleration of microangiopathy. Conclusion: This study suggests that the age at onset of diabetes is an important independent risk factor that is associated with predominant development of microangiopathy in type 2 diabetic patients.

매설 천연가스배관의 지반침하에 의한 응력 분석

홍성호,김우식,김형식,방인완,오규환 한국산업안전학회 1998 한국안전학회지 Vol.13 No.2

This study was initiated to examine the stress and deformation characteristics of the pipelines which were subjected to various environmental conditions in order to confirm their integrity. As the part of them, this paper presents the analysis results for the effect of ground subsidence combined with main loads on buried natural gas pipelines. The ground subsidence which can occur for buried gas pipeline has been classified to the three cases. Finite element method was used to analyze the effect of ground subsidences on pipeline of 26 inch(0.660 m) and 30 inch(0.762 m) diameter used as high pressure (70㎏_f/㎠(6.86 ㎫)) main pipelines of KOGAS. This paper shows the result of stress analysis for the pipelines subjected to those three case ground subsidence. Comparing these results with safety criterion of KOGAS(0.9 σ_y), maximum allowable settlement and loads have been calculated.

황산암모늄에 의한 철산화물의 황산화반응

유영홍,이철태,박용성,홍상의 고려대학교 공학기술연구소 1986 고려대학교 생산기술연구소 생기연논문집 Vol.22 No.1

The reactions between iron oxides, such as α-hematite, magnetite and wuestite with ammonium sulfate were investigated in order to find the possibility of (NH₄)₂SO₄ being a sulfating agent and a new selective separation process of Fe component from natural ore. In these reactions, iron oxides were converted to (NH₄)₃Fe(SO₄)₃ or(NH₄)Fe(SO₄)₂ under various experimental conditions. In proportion to the increase of (NH₄)₂SO₄ mole ratio to iron oxide, the conversion ratio were increased. With an increased reaction temperature, the reaction rate and conversion ratio were increased. Under N₂ gas flow rate = 30㎤/min, reaction time = 3h, the optimum reaction temperature was 350℃ for all iron oxides, and the optimum (NH₄)₂SO₄ mole ratio to the iron oxide were 10.0 for α-Fe₂O₃, 21.0 for Fe₃O₄ and 5.0 for FeO, respectively. Under above mentioned conditions, the conversion of iron oxide to ammonium iron sulfate were 97.31% for α-Fe₂O₃3, 94.33% for Fe₃O₄ and 95.41% for FeO, respectively.

실리콘고무의 가교제 변화에 의한 유전특성

권병휘,이성일,홍진웅,이준웅,이원재 한국고무학회 1987 엘라스토머 및 콤포지트 Vol.22 No.1

The characteristic of the dielectric relaxation in silicone rubbers were studied in the frequency range of 1×10²∼3×10^6 ㎐ at the temperature range of 30℃∼170℃. As the results of the study, it has been confirmed that the silicone rubber containing the cross-linking agents of 2,5-bis(tert-butylperoxy)-2,5-dimethyl hexane exhibit the dissipation spectra of two kind(α, β dissipation) due to the siloxane and methyl groups. Particularly, the maximum value of dielectric loss spectra of silicone rubber combinning the cross-linking agents of 0.7phr to 1.0phr are on the increasing in high frequency region, but the specimen of above 1.0phr become smaller again The energy and the entropy of activation on the molicular motion obtained 18.32㎉/mole and 1.48㎈/mole·deg in measuring condition respectively.

후판 표면 산화층 색상에 미치는 산화층의 표면 현상 및 상분율의 영향

박신화,유경종,이중주,홍순태,손병준 대한금속재료학회(대한금속학회) 2001 대한금속·재료학회지 Vol.39 No.10

It was known that the color of Hematite(Fe₂O₃) is red, while Magnetite(Fe₃O₄) is dark blue. To clarify the origin of red color on the steel plate, the relationship between the volume fraction of oxide phases and the color of steel plate was investigated in this study. The volume fraction of Wu¨stite, Magnetite, and Hematite was quantitatively evaluated by a direct comparison X-ray method using crystal structure informations. Furthermore, the effect of volume fraction and the manufacturing process on the surface color of steel plate was investigated. It was found that FRT(final rolling temperature) played an important role on the plate color.

RF Plasma 법으로 증착된 TiCN 박막의 구조 및 기계적 거동에 관한 연구

위명용,백창현,박상렬,홍주화,강희재 한국열처리공학회 2000 熱處理工學會誌 Vol.13 No.2

The structure and mechanical properties of TiN and TiCN thin films deposited on STD61 steel substrates by the RF-sputtering methods has been studied by using XPS, XRD, micro-hardness tester, scratch tester, and wear-resistance tester. XPS results showed that the TiCN thin film formed with chemical bonding state. The TiN thin films grew with (111) orientation having the lowest strain energy by compressive stress, whereas the TiCN thin films grew with both (111) and (200) orientation, but (200) orientation having the lowest surface energy becomes dominant as carbon contents increase. The pre-etching treatment of substrate did not affect on the preferred orientation of thin films, but it played an important role in improving mechanical properties of thin films such as the hardness, adhesion and wear-resistance. Especially, the TiCN thin films showed the superior wear resistances due to high hardness and low friction coefficient compared with TiN thin films.

Mo 첨가에 의한 Zr 계 합금의 원자로심 재료 특성 향상

권숙인,김명호,이정횡,황선근 대한금속재료학회(대한금속학회) 2000 대한금속·재료학회지 Vol.38 No.6

The role of Mo in Zr-based alloys was studied in terms of the microstructure, texture and corrosion resistance. The base compositions of the experimental alloys were Zr-1Nb and Zr-1Nb-1Sn-0.1Fe to which Mo was added in varying amount up to 0.5%. Buttons of 300 g in weight have been produced by plasma arc remelting (PAR) and processed in sequence by hot forging, hot rolling, beta annealing, cold rolling and recrystallization annealing. It was confirmed that Mo addition resulted in grain refinement: beta grains as well as recrystallized alpha grains. This, in turn reduced the formation frequency and the size of twins and relaxed of the surface normal preferred orientation, f_n. In the corrosion test in water containing 220 ppm LiOH (360℃, 17.9 ㎫), the alloys with up to 0.2% Mo showed a good corrosion resistance whereas that with 0.5% Mo showed a degraded resistance. Apparently, the corrosion resistance was related to the density and morphology of the second phase particles. Alloys containing fine and uniformly distributed β-Nb particles showed good corrosion resistance whereas those containing excessive number or undesirable distribution of particles particularly in uncrystallized region showed degraded corrosion resistance. Overall, the present study suggests that alloying of up to 0.2% Mo should be favorably considered for improving the mechanical properties without impairing the corrosion resistance of Zr-based alloys for nuclear core applications.