Electron Cyclotron Resonance O_2 Plasma에서 증착한 규소 산화 박막의 특성

안명환,서문석,장재선,서성모,이기방,윤창주,이형재,남기석,최규현,손춘배,김용섭,강석희 全北大學校 基礎科學硏究所 1994 基礎科學 Vol.17 No.-

규소 산화막을 ECR-CVD(electron cyclotron resonance-chemical vapor deposition) 증착방법으로 5인치 기판위에 상온에서 증착하고, 증착공정조건인 증착율, 기판온도, 마이크로파의 세기변화 및 플라즈마 혼합기체의 비에 따른 규소 산화막의 특성을 조사하였다. 또한 산화막의 구조적인 특성을 비교하기 위해 FTIR을 이용하여 ECR-CVD 증착한 산화막, RPE-CVD(remote plasma enhanced-CVD) 증착한 산화막 및 열 산화막의 stretching frequency를 측정하였다. 측정된 결과 ECR-CVD로 증착된 산화막이 구조적인 면에서 열 산화막과 거의 같음을 보였다. ECR-CVD로 증착된 산화막의 전기적인 특성을 전류-전압 및 축전-전압 측정에의하여 분석하였다. 축전된 산화막의 전기적인 특성은 산화막의 전하 밀도는 1×10 exp (11)/㎠이였고, 평균 절연 파괴 전압은 약 6 MV/㎝이다. We have grown thin films of SiO_2 at room temperature by using an ECR-CVD system and have investigated the changes in the properties of the deposited films with changes in the processing conditions such as the deposition rate, the substrate temperature, the microwave power and the plasma gas mixing ratio. We also measured the stretching frequency of three kinds of oxides, and ECR-CVD-grown oxide, a PECVD-grown oxide, and a thermally grown oxide, using FTIR analysis to compare their structural properties. The result shows that the structural properties of the ECR-grown oxide are similar to those of the thermally grown oxide. Additionally, the electrical properties of the ECR-grown oxide were investigated by using current-voltage and capacitance-voltage measurements. These electrical results indicate that the oxide charge density and the average breakdown voltage are 1×10 exp (11) ㎝^-2 and 6 MV/㎝, respectively.

Two Stage 발효에 의한 고산도 식초 생산

이영철,이금용,김형찬,박기범,유익제,안평욱,최춘언,손세형 한국산업미생물학회 1992 한국미생물·생명공학회지 Vol.20 No.6

산업적으로 산도 17.0% 이상의 고산도 식초를 생산하기 위하여 반연속식인 1st stage와 유가식인 2nd stage로 구성된 two stage 초산 발효를 온도 30 ℃, 교반속도 600 rpm, 통기량 0.1 vvm에서 실시하였다. 1st stage에서 초기 에탄올 농도를 50.0 g/ℓ, 잔류 에탄올 농도를 5.0 g/ℓ로 정하여 반연속적으로 초산발효를 하고, 2nd stage 에서 발효시간의 경과에 따라 에탄올을 유가식으로 첨가하여 초산발효액내의 에탄올 농도를 5.0 g/ℓ에서 10.0 g/ℓ로 유지했을 때 산도가 17.6%인 고산도 식초를 생산할 수 있었으며, 또한 이 ??의 최대 초산 생산성은 3.3 g/ℓ·hr였다. The production of vinegar containing 16.0 ∼18.0% of acetic acid was examined in two stage fermentation consisting of semi-continuous and fed-batch type. The optimum conditions were obtained when the fermentation was carried out at agitation of 600 rpm, aeration of 0.1 vvm and temperature of 30℃. The initial and residual ethanol concentration in 1st stage were 50.0 g/ℓ and 5.0 g/ℓ, respectively, and the ethanol concentration in 2nd stage was maintained from 5.0 to 10.0 g/ℓ. The maximum productivity was 3.3 g/ℓ-hr and the acidity was 17.6% after the two days of acetic acid fermentation.

당밀의 첨가가 갈근탕박 사일리지의 품질과 산양의 기호성에 미치는 영향

김성복,문계봉,이봉덕,오홍록,배형철,이수기 충남대학교 농업과학연구소 2006 농업과학연구 Vol.33 No.1

Two experiments were conducted to investigate the effects of molasses supplementation to silage materials in ensiling Galgeuntang (herbal medicine) meal on the quality of silage, and its palatability in Korean native goats. In experiment Ⅰ, molasses was added at the levels of 0, 0.5, and 1.0% to Galgeuntang meal with three replicates per treatment. In experiment Ⅱ, three 1.5-yr-old Korean native goats were used to measure palatability. In experiment Ⅰ, lactic acid contents in molasses treatments were significantly(p<0.05) higher, and pH and butyric acid contents were lower than those of non-molasses treatment. In addition, molasses treatment increased total microbial cell counts in MRS medium for lactobacillus, but decreased total microbial cell counts in PDA medium for fungi. Molasses supplementation to silage materials increased in vitro dry matter disappearance. Molasses supplementation tended to increase silage intake in Korean native goat (experiment Ⅱ), but the difference was not significant(p>0.05). It is concluded that molasses supplementation to silage materials in ensiling herbal medicine meal could improve its preservability and palatability, the higher the better.

3D-CT를 이용한 골격성 III급 개방교합자의 악교정 수술 전, 후 설골 및 상기도의 변화

이윤섭,백형선,이기준,유형석 대한치과교정학회 2009 대한치과교정학회지 Vol.39 No.2

본 연구는 골격성 III급 개방교합자의 악교정 수술 전, 후 설골과 상기도의 변화를 3D-CT를 이용하여 관찰하고 이를 정상교합자와 비교하기 위하여 시행하였다. 전치부 개방교합을 동반한 골격성 III급 부정교합으로 진단되어 악교정 수술을 받은 환자 중 12명을 선정 후, 3D-CT를 통해 설골과 상기도의 3차원 입체영상을 분석하여, 악교정 수술 전, 후의 설골의 위치 변화 및 상기도의 부피 변화를 살펴보고, 이의 결과를 정상교합자 10명과 비교하였다. 설골은 골격성 III급 개방교합군에서 악교정 수술 전에 정상교합군의 설골에 비해 전방에 위치하고 있었고 악교정 수술 후 설골은 후, 상방으로 변화하였으나 유의성은 관찰되지 않았다. Hyoid plane과 mandibular plane이 이루는 각은 악교정 수술 전의 골격성 III급 개방교합군이 정상교합군보다 큰 값을 나타내었고, 악교정 수술 후에는 그 차이가 더욱 증가하였다. 골격성 III급 개방교합군의 상기도 부피는 정상교합자보다 작으며 이는, 악교정수술 후에 더욱 감소하였다. 3차원 영상 분석 결과, 골격성 III급 개방교합자의 상기도는 정상교합자에 비해 좁으며, 하악골 후퇴술 이후 더욱 감소하기 때문에 이는 수술적 개선의 안정성에 영향을 줄 수 있음을 알 수 있었다. Objective: The purpose of this study was to investigate the structural changes of the hyoid bone and upper airway after orthognathic surgery for skeletal class III anterior open bite patients, and make comparisons with normal occlusion. Methods: Pre- and post-operative computed tomography (CT) examinations were performed on 12 skeletal class III anterior open bite patients who were treated with mandibular setback osteotomy. Using the V-works 4.0 program, 3-dimensional images of the total skull, mandible, hyoid bone, and upper airway were evaluated. Results: In the Class III openbite group, the hyoid bone were all positioned anteriorly, compared to the Normal group (p < 0.05). The angle between the hyoid plane and mandibular plane in the Class III openbite group before surgery was greater than in the Normal group (p < 0.05), and the difference increased after surgery (p < 0.01). In the Class III openbite group, the volume of the upper airway decreased after surgery (p < 0.001) and the volume of the upper airway was smaller than the Normal group before and after surgery (p < 0.001). Conclusions: The narrow upper airway space in skeletal Class III openbite patients decreased after mandibular setback osteotomy. This may affect the post-surgical stability.

면역학적 접근법을 이용한 미소대장암의 진단 및 외과적 치료

이기형,이석환,고석환 경희대학교 1997 慶熙醫學 Vol.13 No.1

졸 - 겔법에 의한 다공성 알루미나 미분체 제조에 관한 연구 : 2 . 물과 알콕시드의 비가 알루미나 미분체의 결정화 공정에 미치는 영향 2 . The Effect of [ H2O ] / [ Al - alkoxide ]on The Crystallization Mechanism of As - Prepared Particles

이성원,박형상,윤호성,황운연,구기갑,유승준,김용렬,이정운 한국화학공학회 2001 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.39 No.2

알루미늄 알콕시드의 반응속도를 제어하기 위한 혼합용매와 입자제조 과정에서의 응집을 방지하기 위한 분산제로 HPC를 첨가하는 방법에 의하여 구형의 다공성 알루미나 미분체를 제조하였으며, XRD, FT-IR 및 TG-DTA 분석을 통하여 공정변수로 선정한 물과 알루미늄 알콕시드의 비가 제조된 미분체의 결정화 공정에 미치는 영향에 대하여 고찰하였다. 축중합 반응에 첨가된 물과 Al-알콕시드의 비는 제조된 미분체 및 하소 공정을 거친 미분체의 결정구조에 영향을 미침을 알 수 있었다. [H₂O]/[ASB]의 비가 증가할수록 제조된 미분체는 비정질의 Al(OH)₃로부터 점진적으로 AlO(OH)의 화학조성을 갖는 의사-보헤마이트로 결정성이 바뀌었다. 그리고 건조 공정을 거친 미분체의 결정성이 좋을수록 δ와 θ-Al₂O₃는 저온에서 생성되었으나, α-Al₂O₃는 고온에서 생성되었다. 이와 같은 결과는 Al^(3+)이온의 결정 내에서의 배위체 변화와 관계됨을 알 수 있었다. 그리고 [H₂O]/[ASB]=2의 조건에서 제조된 입자는 다른 시료와 달리 600℃에서 η-Al₂O₃로 1,100℃에서 α-Al₂O₃2로 상전이 되었다. Spherical porous alumina particles were prepared by mixed solvent to control the reaction rate of Al-alkoxide and the particle shape with hydroxy-propyl cellulose(HPC). HPC was used as a dispersant to prevent aggregation during the formation of particles. The effect of [H₂O]/[ASB] ratio on the crystallization reactions of as-prepared particles was studied by XRD, FT-IR, and TG-DTA analysis. The mole ratio of water and Al-alkoxide added in the condensation reaction had an important effect on the crystal structure of as-prepared particles and the calcined particles. As the [H₂O]/[ASB] ratio increase, the crystal structure of as-prepared particles was continuously varied from amorphous Al(OH)₃ to pseudo-boehmite with chemical composition of AIO(OH). The samples which have higher crystallinite after drying process were transformed into the δ- and θ-Al₂O₃ at lower calcination temperature, but these sample were transformed into α-Al₂O₃ at higher calcination temperature. This result was thought to be the transformation of the coordination number of Al^(3+) ion in the crystal structure. The particles prepared by [H₂O]/[ASB]=2 condition crystallized to α-Al₂O₃at 600℃ and converted to η-Al₂O₃at 1,100℃ without intermediate phases.

사립체 DNA 뉴클레오타이드 3243 A→G 돌연변이 [MTTL1^*MELAS3243G]에 의한 MELAS 증후군

박기형,김승현,이영주,김희태,김주한,김명호,박성섭 대한신경과학회 1998 대한신경과학회지 Vol.16 No.4

副腎皮質 腺腫을 同伴하는 原發生 Aldosteronism

이기형,전정열 慶熙大學校 1983 論文集 Vol.12 No.-

A 41-year-old-woman with hypertension and hypokalemia underwent adrenalectomy for primary aldosteronism, She was found to have and adenoma in right adrenocortical region on pathologic result. The diagnosis was made by finding low plasma renin activity, which could not be stimulated, and unsuppresable elevated plasma or urin aldosterone. The localization of an adenoma was accomplished by adrenal angioraphy, venography ultrasonogram, and CT. The CT was more helpful to identify the localization of the tumor than other radiologic studies. The patient was recovered completly from hypertension and hypokalemia after operation.

볼베어링 설계를 위한 접촉기구 규명에 관한 연구

임재환,이기형,정인성 全北大學校 1994 論文集 Vol.37 No.-

The performance of ball bearing is evaluated by both the lubrication between ball and race and the condition of the contact mechanism. The contact between ball and race of bearing is considered as point contact, and point contact generally occurs in the condition of the contact between two spheres or between sphere and plane which is basic form. Therefore, first we have to define the contact mechanism of ball and race to know the performance of the ball bearing. By this reason, in the paper we defined the contact mechanism by using the actual surface parameters.

TGA를 이용한 가교폴리에틸렌의 방사선 열화 평가

이청,김기엽,류부형,임기조 한국안전학회 2003 한국안전학회지 Vol.18 No.2

Radiation degradation of crosslinked polyethylene(XLPE) was investigated using thermogravimetric analysis (TGA), The results of TGA were compared with FT-IR, melting temperature, oxidation induction time, and elongation al break on the XLPE exposed by γ-ray. 5% decomposition temperature of γ-ray irradiated XLPE showed similar tendencies with the case of elongation at break. Both properties agreed below 1000 kGy, however, did not show any remarkable characteristics above 1000 kGy, these properties can be useful to evaluate the radiation degradation of XLPE for only low irradiated region. Above 1000 kGy, the thermal decomposition activation energy showed decreased, on the contrary, increasing below 1000 kGy. Compared with FT-IR spectrum of irradiated XLPE, it was confirmed that the oxidation reaction was still occurring below 1000 kGy. Radiation degradation of XLPE was dependent upon the irradiation doses, TGA can be a useful tool to evaluate the degradation.