Boro-Nitriding 처리한 FC-25계 편상흑연주철의 표면특성에 관한 연구

허인창,손근수,윤재홍,조동율,박봉규,김현수,김인수 국립7개대학공동논문집간행위원회 2004 공업기술연구 Vol.4 No.-

Surface properties and oxidation behaviors were studied for FC-25 gray cast iron (GCI), plasma nitrided FC-25 GCI (P-N GCI), powder boronized FC-25 GCI (B GCI) and powder boronized N GCI (B-N GCI). A boride (Fe2B, FeB) layer with a tooth shape was formed by boronizing GCI at temperatures of about 650℃. The thickness and hardness of the layers were proportional to the boronizing temperature and time. The hardness was decreased by increasing boronizing depth. The activation energy for boride formation was 73.8kJ/mol. The thickness of the graphite layer formed by boronizing was increased by the temperature and time. A silicon layer insoluble in borides was accumulated under the boride layer. The major phases were Fe4N, Fe3N and FeN in a nitride layer formed by plasma. The thickness and hardness of the layer were increased with nitriding temperatures and time under the Fe4N decomposition temperature of 680℃. The hardness was maximum at the surface and decreased with nitrided depth on B-N GCI at 700℃, above the decomposition temperature of the Fe4N. Hardness of B-N GCI at the layer depth of 10 ㎛ was ≒1000Hv, which was lower than ≒1500Hv of the B GCI at the same condition. Also the layer thickness was 50 ㎛; deeper than that of B GCI by 10 ㎛ The reasons were that the nitrogen given off by the decomposition made the layer porous and facilitated the diffusion of oxygen and other reactants. The samples were oxidated at 800℃ for 48hrs under atmospheric air. Oxidation rate was in decreasing order of N GCI, GCI, B GCI and G-N GCI. Oxidation rates were greatly influenced by the diffusion of nitrogen formed by Fe4N decomposition over the decomposition temperature of 680℃ and by the oxidation barrier of the less corrosive boride layer.

Decomposition of excess sludge in a membrane bioreactor using a turbulent jet flow ozone contactor

Hwang, B.K.,Son, H.S.,Kim, J.H.,Ahn, C.H.,Lee, C.H.,Song, J.Y.,Ra, Y.H. Korean Society of Industrial and Engineering Chemi 2010 Journal of industrial and engineering chemistry Vol.16 No.4

<P>We have investigated the decomposition of excess sludge generated in a membrane bioreactor using a turbulent jet flow ozone contactor (TJC), which induced both hydrodynamic cavitation and ozonation reactions. We monitored the effects of various TJC operating parameters on the properties of the sludge, including the particle sizes, the particle size distribution, and the levels of soluble COD, total COD, and mixed liquor suspended solids. The TJC enhanced the degree of sludge reduction while consuming less energy, relative to conventional ozonation treatment systems, because of the synergic effects of hydrodynamic cavitation and zonation. The hydrodynamic cavitation generated in the TJC increased the ozone mass transfer efficiency, which in turn promoted the rate of disintegration and solubilization of the sludge particles. Crown Copyright (C) 2010 Published by Elsevier B.V. on behalf of The Korean Society of Industrial and Engineering Chemistry. All rights reserved.</P>

Temperature Dependent Study of Random Telegraph Noise in Gate-All-Around PMOS Silicon Nanowire Field-Effect Transistors

Hong, B B,Choi, L,Jung, Y C,Hwang, S W,Cho, K H,Yeo, K H,Kim, D,Jin, G Y,Park, D,Song, S H,Lee, Y Y,Son, M H,Ahn, D IEEE 2010 IEEE TRANSACTIONS ON NANOTECHNOLOGY Vol.9 No.6

<P>We report the random telegraph noise observed in gate-all-around (GAA) PMOS silicon nanowire FETs (SNWFETs) with the radius of 5 nm, at various temperatures (s) down to 4.2 K. From the -dependence of the capture/emission time, we obtain the energy and the charging status of the trap states. The gate bias dependence and the -dependence of the scattering coefficient-mobility product extracted from the relative fluctuation amplitude of the drain current are consistent with the fact that the surface roughness scattering is dominant in GAA PMOS SNWFETs.</P>

약(葯)배양 기법 이용한 이탈리안 라이그라스 식물체 생산

김기용,강경민,최기준,임용우,장요순,성병렬,손대영,이병현,조진기 Plant molecular biology and biotechnology research 2002 Plant molecular biology and biotechnology research Vol.2002 No.-

We obtained regenerated Italian ryegrass (Lolium multiflorum Lam.) plants by anther culture. When Italian ryegrass anther was incubated for 20 days on callus induction medium, MS medium containing 30 g/ℓ of NAA and 1 mg/ℓ of kinetin its callus was induced. The ratio of callus induction was 9.2 %, the mean of callus weight was 8.6 mg/callus/anther. When Italian ryegrass callus was incubated for 50 days on plant regeneration medium, MS medium containing 30 g/ℓ of sucrose, 1 mg/ℓ of NAA and 2 mg/ℓ of kinetin, Italian ryegrass plant was regenerated. The ratio of plant regeneration was 26%.

소의 동결수정란이 수태에 미치는 영향;3. 오단계부유에 의한 그리세롤제거란의 외과적이식의 영향

이광원,지설하,조윤연,손동수,임경순,오대균,석호봉,김호중,오성용,윤충근,지디마혼 한국축산학회 1984 한국축산학회지 Vol.26 No.5

Frozen embryos with highest genetic-potency were imported from America in cooperation with the Holstein-Friesian of America and transferred to the recipients in the National Animal Breeding Institute. The estrus synchronization were induced with 64 cows by intramuscular injections of 25㎎ PGF₂α between 11 days interval. The frozen embryos thawed at 32℃ were rehydrated within the medium at 5 steps in order to remove glycerol. The embryos were transferred to 30 recipients with surgical method and the results were as follows: 1. Among 64 cows, heat inducing rate after 1st and 2nd injections of PGF₂α was 53.1 and 76.6%, respectively. 2. Most of synchronized estrus was induced within 2-4 days after PGF₂α injections, however prevalent one was within 3 days. 3. Heat inducing rate after 1st and 2nd injections of PGF₂α was 35.5 and 77.4% in the heifer and 69.7 and 75.8% in the cow. The rate after 2nd injection was much higher than 1st injection and the cow showed much higher rate than the heifer in 1st injection. 4. Among 30 recipients, 20 cows (66.7%) has corpus luteum in right ovary and 10 cows (33.3%) in the left. Three cows in 16 cows with A-class CL, 7 cows in 12 cows with B-class CL and 1 cow in 2 cows with C-class CL showed highest conception rate. 5. The frozen embryos staged from late morula to expended blastocysts were transferred and concepted. Conception was possible even in the C-class embryo. 6. Among 30 recipients, 11 cows (36.7%) were concepted and the cows (37.5%) showed slightly higher conception rate than the heifer (36.7%). 7. The conception rate of frozen embryo was 1 S.8% in first trial with 6 steps glycerol equilibration, 16.7% in 2nd trial with 2 steps sucrose equilibration and 36.7% in this 3rd trial with S steps glycerol equilibration. Third trial showed highest conception rate. 8. Among 79 recipients, 26 cows (32.9%) were concepted and farrowed. The conception rate of fresh embryos (55.6%) was higher than the frozen (26.2%) and that of the surgical (35.0%) was slightly higher than the nonsurgical (30.8%).

유전질환 등록 시스템 운영, 유전자 정보 Database 구축 및 유전자 진단 시스템 확립

구수경,이환석,손용규,김성수,이광수,김지인,서일선,진수정,정동기,오범석,정성철,이진성 국립보건연구원 2000 국립보건원보 Vol.37 No.-

Peroxiredoxin 6 expression is inversely correlated with nuclear factor-κB activation during Clonorchis sinensis infestation

Pak, J.H.,Son, W.C.,Seo, S.B.,Hong, S.J.,Sohn, W.M.,Na, B.K.,Kim, T.S. Pergamon ; Elsevier Science Ltd 2016 FREE RADICAL BIOLOGY AND MEDICINE Vol.99 No.-

Clonorchis sinensis is a carcinogenic human liver fluke. Its infection promotes persistent oxidative stress and chronic inflammation environments in the bile duct and surrounding liver tissues owing to direct contact with worms and their excretory-secretory products (ESPs), provoking epithelial hyperplasia, periductal fibrosis, and cholangiocarcinogenesis. We examined the reciprocal regulation of two ESP-induced redox-active proteins, NF-κB and peroxiredoxin 6 (Prdx6), during C. sinensis infection. Prdx6 overexpression suppressed intracellular free-radical generation by inhibiting NADPH oxidase2 and inducible nitric oxide synthase activation in the ESP-treated cholangiocarcinoma cells, substantially attenuating NF-κB-mediated inflammation. NF-κB overexpression decreased Prdx6 transcription levels by binding to two κB sites within the promoter. This transcriptional repression was compensated for by other ESP-induced redox-active transcription factors, including erythroid 2-related factor 2 (Nrf2), hypoxia inducible factor 1α (HIF1α), and CCAAT/enhancer-binding protein β (C/EBPβ). Distribution of immunoreactive Prdx6 and NF-κB was distinct in the early stages of infection in mouse livers but shared concomitant localization in the later stages. The intensity and extent of their immunoreactive staining in infected mouse livers are proportional to lesion severity and infection duration. The constitutive elevations of Prdx6 and NF-κB during C. sinensis infection may be associated with more severe persistent hepatobiliary abnormalities mediated by clonorchiasis.

성장홀몬과 내분비계 질환

박창윤,최규옥,김기황,허갑범,유경자,이혜리,손희영 대한핵의학회 1979 핵의학 분자영상 Vol.13 No.1

1976년 1월부터 1979년 3월까지 연세대학교 부속 세브란스병원에 내원하여 뇌하수체 기능부전이 의심되어 성장홀몬의 분비능을 관찰하기 위해 L-Dopa 자극시험을 실행했던 35명과 L-Dopa 자극시험과 포도당 부가반응을 관찰하였던 4예의 달단비대증 환자를 연구 검토하여 다음과 같은 결과를 얻었다. 1) 각종 질환에서 성장홀몬의 기저치는 Sheehan씨 증후군에서는 평균치는 대조군보다 낮으나 통계적으로 유의한 차이는 없었고 당뇨병 환자에서도 평균치는 높으나 통계적으로 유의한 차이는 아니었다. 말단비대증 환자 4예 모두 대조군보다 현저한 증가를 보여주었다. 2) 당뇨병 환자 13명종 9명은 당뇨병성 망막증이 합병되었던 환자였고 이중 6명에서 L-Dopa 자극에 성장홀몬의 분비항진을 보여주었다. 망막증이 없었던 4명 중 1명에서만 분비 항진을 보여주었다. 3) Sheehan씨 증후군 10예중 L-Dopa에 분비항진을 보여준 경우는 2예였다. 4) 뇌하수체 혐염기성선종 8예중 L-Dopa 자극반응에 분비항진을 관찰한 수 있었던 것은 1예였다. 5) 4명의 말단비대증 환자중 3명은 호산성 선공이였고 1명은 혐염기성 선종이였다. 이중 3명에서 L-Dopa 자극시험을 행하였는데 1명은 그 측정치가 80 ng/ml 이상이어 반응 판정이 불가능했고 2명은 L-Dopa에 paradoxical response를 보여주었다. 포도당 부가검사를 시행한 2명 모두에서 포도당 투여후 억제반응을 보여주었다. 6) 두개인두종 2예중 1예에서 L-Dopa 자극반응을 보여주었 저신장(short statas)는 2예중 1예에서 L-Dopa 자극후 분비 항진을 보여주었다. This is an analysis of 39 patients studied at the Yonsei Medical Center from January, 1976 to March 1979. Of these 35 patient were suspected of having hypothalamic insufficiency and subjected to the L-Dopa stimulation test to observe growth hormone sceretory function while four acromegaly patient received the glucose loading test and L-Dopa stimulation test. The results are as follows: 1) The basal level of GH in the various disease was as follows: a) The basal level was lower than the control level but was not statisfically significant b) In diabetes the mean value tended to higher than the control level but was not significant statistically c) In all four acromegaly patients the GH level was significantly higher than the control level 2) Of 13 patients with diabetes, nine had diabetic retinopathy, and of those nine, six showed increased L-Dopa response. However, of the four non retinopathic DM patients, onl one showed increased response to L-Dopa. 3) Two patients out of ten with Sheehan's syndrome responded to L-Dopa stimulation. 4) One Patient of eight prith pituitary chromophobe adenoma responded to L-Dopa stimulation. 5) Four acromegaly patients revealed 3 acidophilic adenoma and one chromophobe adenoma histologically. Of patients receiving the L-Dopa stimulation test. Two showed a paradoxical response. Two patients who received the glucose loading test showed supressed response. 6) Of two craniopharyngioma patients, one showed increased GH response after L-Dopa stimulation. Increased response of GH after L-Dopa stimulation was seen in one two craniopharyngioma patients and also in one of two patients with short statasture.

박막자기헤드의 집적공정 기술개발에 관한 연구

이석윤,허명수,손동수,황병철,조동율,천희곤,오태희,송병무,송한식,이우형,이광철,김오규,권영규,구경완 경북대학교 센서기술연구소 1995 센서技術學術大會論文集 Vol.6 No.1

The thin film growing processes and the photolithographic techniques involved in the manufacturing of thin film magnetic heads are discussed. The thin film heads are composed of the hundreds of electromagnetic transducers on a single wafer and are made of Al_(2)O_(3)-TiC substrate on which Al_(2)O_(3) film as a insulating, protective layer and gap material, Cu film as a multi-turn coil and permalloy film as a magnetic material are deposited and patterned. In this article we will introduce how the thin film heads is fabricated and differ from an integrated semiconductor device. An effort is devoted to develop the formation of PR frame using a lithography process and finally the thin film heads manufacturing technologies.

Thermoelectric properties of Bi2Te2.7Se0.3 nanocomposites embedded with MgO nanoparticles

Joo, S. J.,Son, J. H.,Min, B. K.,Lee, J. E.,Kim, B. S.,Ryu, B.,Park, S. D.,Lee, H. W. 한국물리학회 2016 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol. No.

<P>Bi2Te2.7Se0.3 bulk materials containing x vol% MgO nanoparticles (average particle size ae 100 nm, x = 0, 0.5, 1.0, 1.5) were synthesized by using high-energy ball milling and plasma- activated sintering (PAS) without any special process for nanoparticle dispersion. A microstructure investigation using a scanning electron microscope (SEM) confirmed that MgO nanoparticles were properly dispersed in the Bi2Te2.7Se0.3 matrix and that the grain size was smaller in MgO-containing samples due to suppressed grain growth. The resistivity and the maximum Seebeck coefficient of Bi2Te2.7Se0.3 increased with increasing MgO content whereas the thermal conductivity decreased in the measurement temperature range of 298 K - 573 K. As a result, the maximum dimensionless figure of merit, ZT (max), increased about 8.5% in this study, from 0.806 for pristine Bi2Te2.7Se0.3 to 0.875 when x = 1.5. The ZT (max) was observed to shift to lower temperature, the electron concentration to decrease, and the electron mobility to increase with increasing x, which were explained using a hypothesis that the Te (Bi) antisite defect concentration decreased as the MgO content increased. In summary, the addition of MgO nanoparticles has been shown to be a simple and effective method to improve the low-temperature thermoelectric properties of n-type Bi2Te3 materials.</P>