SrTiO₃첨가에 따른 (x)BaTiO₃-(1-x)SrTiO₃의 유전적, 전기적 특성

정해덕,장동환,김덕근,홍경진,최창주 木浦大學校 工業技術硏究所 1998 工業技術硏究誌 Vol.8 No.-

In this paper, a ferroelectric material BaTiO3 was added to SrTiO3, then (x)BaTiO3-(1-x)SrTiO3(0.7≤x≤1) ceramics were fabricated with stable electrical properties in high voltage. Microstructures and electrical properties were investigated according to mixing conditions of addition material SrTiO3. As a result of the investigation of all experiments, the shrinkage was excellent in 0.9BaTioO3-0.1SrTiO3. The grain size was increased, the curie temperature was shifted low temperature. The 0.9BaTiO3-0.1SrTiO3 was appeared stable property in temperature vs. permittivity. Also, 0.9BaTiO3-0.1SrTiO3 was showed stable dielectric properties at 25~85[C]. V-I properties of specimen were observed in the temperature range of 21~143[C], were divided into three regions. the region I below 10[kV/cm] was shown Ohmic conduction, the region II from 10 to 30[kV/cm] was explained by the poole-Frenkel emission theory and the region III above 30[kV/cm] was analysed by the tunneling effect.

노인의 특성을 반영한 단위세대 리모델링 제안 : 장애정도가 낮고 일상생활이 가능한 임대아파트 거주 독거노인 2인을 대상으로

홍유석,제해성,권순정 한국의료복지시설학회 2007 의료·복지 건축 Vol.13 No.2

As a result of rapid aging speed in our society, it is necessary to supply a lot of housing for older people in near future. When we think that high portion of residence in rental housing complex composed of small units is the elderly, the housing units in those apartments have to be designed for the physical, mental, social, and economical conditions of elderly people who lives in such a residential complex. Considering these living conditions of the elderly, this study proposes a remodeling prototype of a living unit for older people in rental housing complex. For the research of this topic, various characteristics of the elderly and the environmental requirements for them firstly have been analysed from the literature survey and the interviews with two residents living in a rental apartment. And the design considerations for each space of the housing unit such as entrance, living room, bed room, bath room, and so forth have been explored. Based on the design guidelines above, the remodeling plan of a housing unit for older people has been propose as a result of this study.

CO₂아크 용접 근로자의 뇌 MRI 고신호강도 3례

홍영습,정해관,김준연,이용희,김지용,사공준,임현술,이중정,임명아 동아대학교 부설 산업의학연구소 1999 산업의학연구소 논총 Vol.- No.4

We experienced three cases of high signal intensity observed by Brain Magnetic Resonance Imaging in CO₂ are welders of steel-frame manufacturing industry. Case 1 was a 35 years old man who has been an CO₂ arc welder for 10 years, admitted a sudden onset of tonic clonic seizure. He complained fever, chilling and myalgia since 3 days before admission. On admission, in the test of manganese exposure indices, manganese concentrations of blood, urine and scalp hair were 5.17 ㎍/dl, 22.00 ㎍/l and 31.25 ppm respectively. Case 2 was a 35 years old man who has been an CO₂ arc welder for 20 years. On admission, He complained fatigue, numbness and weakness of extremities, and decrease of libido. In the test of manganese exposure indices, manganese concentrations of blood, urine and scalp hair were 6.34 ㎍/㎗, 14.62 ㎍/l and 57.87 ppm respectively. In neurologic examination, Palmo-mentle reflex and Myerson sign were observed. Case 3 was a 33 years old man who has been an CO₂ arc welder for 16 years. On admission, He complained loss of appetite, numbness of extremities, fatigue and decrease of attention. In the test of manganese exposure indices, manganese concentrations of blood, urine and scalp hair were 5.14 ㎍/㎗, 13.79 ㎍/l and 50.08 ppm respectively. In neurologic examination, Myerson sign was observed. In brain magnetic resonance imaging, T1WI showed symmetrical high signal intensity in basal ganglia and midbrain of three cases. Authors argued that they were developed by manganese exposure, and we considered that follow up study would be necessary.

전위된 상악 견치 및 하악 측절치의 치험례

권해숙,현홍근,김영재,김정욱,장기택,김종철,한세현,이상훈 大韓小兒齒科學會 2009 大韓小兒齒科學會誌 Vol.36 No.4

Tooth transposition is an anomaly of eruption characterized by the interchanged positions of two adjacent teeth, which is divided into complete and incomplete transposition. There are three common approaches for treating transposition: aligning the involved teeth in their transposed positions, moving them to their correct anatomic position in the arch and extracting one of the transposed teeth. Considerations in treatment plans are esthetic, function, risk of jeopardizing the roots and damaging the supporting structures, position of the root apex, developmental stages of teeth and expected compliance. The presented case reports described one maxillary canine-the first premolar transposition and two mandibular lateral incisor-canine transpositions. The former transposed teeth were arranged in their transposed position, and the latter transposed teeth were rearranged into their normal position. 치아전위란 인접한 두 치아의 위치가 서로 바뀐 치아 위치 이상을 말하며, 치관과 치근의 위치에 따라 완전전위와 불완전전위로 나눌 수 있다. 하악보다는 상악에 편측성으로 호발하며, 특히 상악 견치에서 자주 발생한다. 전위는 발견 시기와 전위된 양상에 따라 치료방법이 달라질 수 있다. 본 증례는 상악 견치와 제1소구치 간의 전위가 일어난 10세 7개월의 환아와 하악 측절치와 견치 간의 전위가 일어난 8세 11개월 환아와 8세 9개월 환아의 교정치료에 대한 것으로 양호한 치료 결과를 얻었고, 증례 별로 치료방법의 차이점에 관한 고찰을 하였기에 이를 보고하는 바이다.

Bethe-Salpeter 방정식의 특성과 해Ⅰ. : Bethe-Salpeter 방정식의 특성분석 Review and Analysis of Properties of the Bethe-Salpeter Equation

김정홍,박해용 全北大學校 1983 論文集 Vol.25 No.-

In order to understand the role of the relative time (or energy) variable and to find some clues to the actual properties of the Bethe-Salpeter equation for the relativistic two-body bound states we have reviewed and analyzed its properties. Thus we have discussed the orthonormality, Lorentz deformation of the Bethe-Salpeter wave function, as well as the gauge invariances for the relativistic two-body scatterings and bound states in quantum electrodynamics.

장기투석을 받은 만성 신부전 환자에서 발생한 종양에 관한 고찰

황정화,이혜경,홍현숙,박재성,김대호,권귀향,최득린,황승덕,이희발 순천향의학연구소 1996 Journal of Soonchunhyang Medical Science Vol.2 No.2

The authors tried to evaluate tumor occurrence in long-term dialysis patients with chronic renal failure. Among 359 patients, 20 patients (about 5.6%) were diagnosed with malignancy during long-term dialysis from the period of 1983 to 1995 at our nephrology department. The ultrasonographic and computed tomographic findings including the clinical features of 20 patients that were retrospectively reviewed. The mean age of the patients was 53 (37-75)years old and the ratio of male to female was 9:1. Among the 20 cases, 7 cases of hepatoma (35%) were developed. Among them, urinary tract tumors such as renal and bladder cancer were developed in 4 (20%) and 2 (10%) of the cases. Other malignant tumors were lymphoma, stomach cancer, uterine cervical cancer, cholangiocarcinoma, lung cancer, meningioma, and acoustic neuroma one case of each (each of 5.3%). The most common tumor in patients with chronic renal failure, who were receiving long-term dialysis, was hepatoma and the second most common tumor was cancer of the urinary tract such as kidney and bladder.

레진시멘트의 중합방법이 포스트의 결합강도와 접착계면에 미치는 영향

김문홍,김혜정,조영곤 대한치과보존학회 2009 Restorative Dentistry & Endodontics Vol.34 No.2

본 연구에서는 2종의 이원중합 레진시멘트 (RelyX ARC와 Variolink Ⅱ)를 이용하여 접착제와 레진시멘트의 중합방법 (자가중합과 광중합)이 섬유포스트와 근관 상아질의 결합강도와 접착계면에 미치는 영향을 상호 비교하기 위하여 시행하였다. 단근관을 갖는 발거된 32개의 하악 소구치에 근관을 충전한 후, FRC Postec system의 Reamer로 9 mm 깊이의 포스트 공간을 형성하였다. 레진시멘트의 종류와 중합방법에 따라 4개의 군 (R-SC 군,. R-LC군, V-SC군, V-LC군)으로 분류하였다. 포스트 공간에 각 군의 접착제를 도포한 후 레진시멘트틀 주입하고, No. 3 FRC Postec 포스트를 위치시켜 자가중합 또는 광중합시켰다. 각 군의 치근을 실온의 증류수에 24시간동안 보관한 다음, 저속의 diamond wheel saw를 이용하여 치관부에서 치근단두를 향해 1.5 mm 두께로 연속적으로 횡절단하여 1개의 치근에서 3개의 절편을 얻었다. 각 군의 절편 (21개)은 만능시험기에서 push-out 검사를 시행하였고, 각 군의 강도 값은 반복측정 two-way ANOVA와 one-way ANOVA를 이용하여 비교 분석하였다. 각 군의 절편 (3개)은 주사전자현미경하에서 섬유포스트, 레진시멘트 및 치근 상아질 간의 계면을 관찰, 비교하였다. 본 연구의 결과 전 부식 레진시멘트를 이용하여 섬유포스트를 포스트 공간에 합착할 경우, 접착제와 레진시멘트의 중합방법은 근관 상아질의 결합강도에 영향을 주었으며, 광중합보다 자기중합 방법이 우수한 결합강도와 계면을 나타내었다. The purpose of this study was to compare the effect of curing methods of adhesive resins and resin cements in the root canal. Crown portions of 32 single-rooted mandibular premolars were removed Routine endodontic treatment was done and 9 mm deep post spaces were prepared within root canals No. 3 FRC Postec posts (Ivoclar-Vivadent AG. Liechtenstein) were cemented in the post spaces by self-(SC) or light-curing (LC) using two dual-cured adhesives (Adper Scotchbond multi-purpose plus and Exite DSC ) and resin cements (RelyX ARC and Variolink Ⅱ). They were assigned to 4 groups (n=8): R-SC, R-LC, V-SC, V-LC group. After stored in distilled water for 24 hours each root was transversally sectioned with 1.5 mm thick and made three slices. The speimens were subjected to push-out test in a universal testing machine (EZ Test Shimadzu Co., Japan) with a crosshead speed of 1 mm/min. The data were analyzed with repeated ANOVA and one-way. ANOVA. Also the interface of post-resin cement and resin cement-canal wall of each group was observed under FE-SEM. When fiber posts were cemented into the root canal using total-etch adhesives, the bond strength and adaptation between post and root canal dentin was affected by curing method. Self-cure of adhesives and resin cements showed higher bond strength and closer adaptation than light-cure of them.

서울의 Penicillinase Producing Neisseria gonorrhoeae 발생빈도(1998)

김재홍,김준호,반재용,이정우,황성주,정준규,정성태,강진문,조흔정,홍창의,정혜신,이한승,김이선,이봉길,이종호,선영우,한기덕,윤성필,이성훈,안종성,박석범,문승현,조항래,김형섭,류지호,황재영,박준홍,손상욱 한양대학교 의과대학 2001 한양의대 학술지 Vol.21 No.1

In recent years, gonorrhea has been pandemic and remains one of the most common STDs in the world, especially in developing countries. For the detection of a more effective therapeutic regimen and assessing the prevalence of Penicillinase Producing Neisseria gonorrhoeae(PPNG), we have been trying to study the patients who have visited the Venereal Disease Clinic of Choong-Ku Public Health Center in Seoul since 1980 by menas of the chromogenic cephalosporin method. In 1998, 93 strians of N. genorrhoeae were isolated, among which 60(64.5%) were PPNG. The prevalence of PPNG in Seoul, which had been decreased to 39% in 1996 after a peak of 74.3% in 1993, is increased to 64.5% in 1998.

유치 수복물에 따른 주변 법랑질의 탈회 저항성 : QLF를 이용한 연구

권해숙,현홍근,김영재,김정욱,장기택,김종철,한세현,이상훈 大韓小兒齒科學會 2010 大韓小兒齒科學會誌 Vol.37 No.1

본 연구에서는 유치 수복물의 불소 방출 여부에 따른 주변 법랑질의 탈회 저항성과 재광화 효과를 살펴보고자 하였다. 건전 유전치 48개를 16개씩 임의로 세 군으로 나누어, FiltekTM Z250(1군), F2000(2군), KetacTM N100(3군)을 사용하여 제조사의 지시에 따라 충전하였다. 3일 동안 인공 우식 병소를 유발한 후, 14일 동안 인공 타액에 담가 재광화를 유발하였다. Quantitative light-induced fluorescence(QLF)를 이용하여 실험 단계와 시간에 따른 무기질 소실량(ΔQ)의 변화를 관찰한 결과는 다음과 같다. 1. 탈회가 일어난 인공 우식 병소의 ΔQ 값은 3군, 2군, 1군 순으로 작게 나타났고, 이 중 3군은 1군에 비해 유의한 탈회 저항성을 보였다. 2. 1군, 2군, 3군 모두 재광화 1일 후부터 초기 인공 우식 병소의 ΔQ 값과 비교 시 유의한 차를 보였으며, 관찰 기간 동안 지속적인 증가 양상을 나타내었다. 3. 재광화 속도를 의미하는 Δ(ΔQ)/일 값은 각 군에서 처음 1일 동안 유의성 있게 크게 나타났으며, 그 이후 급속히 감소하였다. 4. 수복 재료에 따른 재광화 정도는 각 군 간에 유의한 차이가 없었다. The objective of this in vitro study was to detect and monitor demineralization and remineralization of primary teeth according to restorative materials using quantitative light-induced fluorescence (QLF). A single bur hole was drilled on the each sound forty eight primary anterior teeth, and the specimens were divided into three groups. The cavity was restored with FiltekTM Z250(Group 1), F2000(Group 2), KetacTM N100(Group 3) following the manufacturer's instructions. The teeth were subjected to the demineralizing buffer for 3 days, and then subjected to a remineralizing buffer for 14 days. The change of mineral loss(ΔQ) according to the stages was evaluated by QLF and the following results were obtained: 1. When demineralization was done, ΔQ was increased as follows. : Group 1 (-110.79 ± 27.77) < Group 2 (-104.84 ± 28.95) < Group 3 (-90.16 ± 21.87) : Resistance to demineralization was statistically significant in Group 3. 2. There was a statistically significant increase in ΔQ of all groups since 1st day of remineralization 3. The rate of remineralization, Δ(ΔQ)/day, showed significant high value in each group on the 1st day then decreased rapidly. 4. There was no statistically significant difference in the degree of remineralization among restorative materials.

Escherichia coli 패혈증 환자에 합병된 대칭적 하지 말단 괴사증 1예

남해성,유진홍,권순석,민준기,조현선,박민경,심병주,남유정,이지인,김진수,길욱현,조근종,신완식 대한감염학회 2005 감염과 화학요법 Vol.37 No.6

We have encountered a rare case of symmetrical peripheral gangrene complicating Escherichia coli sepsis in a 47-years-old male. He was successfully treated with antibiotics, anticoagulants, and vasodilator. To our knowledge, this is the first report on symmetrical peripheral gangrene complicating E. coli sepsis in Korea.