PUMP 加壓 管水路의 經濟的 管經決定

梁相鉉,金煥起,裵主星 全北大學校 1978 論文集 Vol.20 No.-

The laying cost for the pipe line pressed by a pump is depend on the costs for the pump and pipes. The most economical pipe diameter is obtained when the summation of costs for the pump and pipes is minimum. Author studied on the most economical pipe diameters of PVC and cast-iron pipe lines in the water supply works, and obtained the general and occasional formula based on our social situations.

타타늄의 열처리 조건에 따른 동전위 양극분극특성 및 표면 미세구조 변화

주동현,이용렬,정영화,양홍서,박상원,이도재,송호준,박영준 大韓齒科器材學會 2002 대한치과재료학회지 Vol.29 No.2

The corrosion resistance of metallic implants is essential for successful implant osseointegration. Moreover, the implant surface should have appropriate surface roughness for the attachment of the osteoblast and collagen fibrils. When titanium is exposed to air a thermodynamically very stable oxide film is formed at once. This oxide is very thin and yet it protects the metal from corrosion instantaneously. However, the oxide would not be ideal, and it would be supposed that the state of oxide film would be various by the different conditions when it is formed. The objective of this study was to evaluate the electrochemical properties and surface microstructural changes of titanium after passivation treatment or exposure to high heat (in vacuum or in air). ASTM grade 2 commercially pure titanium (Ti) disks of 10㎜ diameter were wet ground and polished with 240 and 600 grit SiC, and then ultrasonically cleaned with distilled water and ethanol. Cleansed as-received samples (As-R group) were passivated with 30% nitric acid solution at 50℃ for 15 minutes to make the Pas group. The Std-V samples were made by treating the Ti disks in vacuum quartz tube (10^-8 Torr) at 530℃ for 40 min for stress relieving, followed by annealing at 700℃ for 90 min, and then slow cooling to room temperature. The Std-A samples undergo identical procedure as the Std-V group except that it is done in air. For 530℃-V samples, Ti disks were heated at 530℃ for 40 minutes and slow cooled to room temperature. The 1000℃-V samples were produced by heating Std-V specimens again at 1000℃ for 2 hr, followed by cooling to room temperature. 530℃-A and 1000℃-A samples were also prepared. Potentiodynamic anodic polarization measurement, SEM, AFM and XRD analysis were performed to evaluate the effects of the various treatments. The difference in the mean values of E_corr between groups showed statistically significant difference (P<0.05), but that of I_corr did not show significance (P>0.05). When Ti surface was passivated there was a shift of corrosion potential (E_corr) in the noble direction and a lower corrosion current density (I_corr) value. Std-A samples showed most noble E_corr value among the tested groups. 530℃-V samples showed more noble E-corr than other tested groups except Std-A group. 1000℃-V samples showed more noble E-corr than those of Std-V sample. In the case of Std-, 530℃- and 1000℃-groups, -A sub-groups showed better corrosion resistant characteristics than -V sub-groups in regard to E-corr and I_corr values. In the SEM observations, the surfaces of the As-R samples showed only scratch line on smooth surface. In Pas samples, thick oxide layer covered the surface under high magnification observation. 530℃-A samples were covered by oxide granules, and Std-A samples had 25~50 nm-thick acicular oxides. The 1000℃-A samples were covered by coarse oxide crystals with a granule diameter of 0.1~0.6 μm having a gross appearance of milky white color, which was identified by XRD as a rutile. On the other hand, 1000℃-V samples showed an Widmansta¨tten structrue of which the orientation of the lattice is formed along crystallographic planes of the parent crystals. On the AFM observation, 530℃-A samples showed RMS roughness of 79.38 nm which is 5 times rougher than those of the As-R samples. Std-A sample had a roughness of 330.47 nm which is about 20-times rougher than that of the As-R sample. 1000℃-A samples were covered by coarse granular oxides and the roughness were about 0.56 μm. Vacuum sub-group samples showed a more smooth surface than air sub-group samples, and the oxide film was more dense. Due to variability of the surface treatment and heat treatment conditions, the process of the oxide formation seems to be affected thereby making the corrosion properties and surface micro-morphology different. However, more various electrochemical analysis together with surface analysis, and an investigation for the effects of those on the osteoblast cell adhesion and calcium phosphate apposition are needed for the improvement of the osseointegration rates of the titanium implants.

Verticillium sp.가 생산하는 cellulase의 정제 및 그 성질

유주현,홍대희,양융,진효상 연세대학교 산업기술연구소 1986 논문집 Vol.18 No.1

The cellulase of verticillium sp. was purified to investigate its some properties. The enzyme purification was carried out by ammonium sulfate fractionation, and column chromatography of Sephadex G-50, G-100 and DEAE Sephadex A-25, with its specific activity increased to 17 fold. The molecular weight was estimated to be 46,000 by gel filtration. The optimum pH and temperature were pH 7 and 50℃, respectively. The enzyme was stable over the range of pH5-7 at 50℃ for 1 hour. But half of its activity was lost after 2 hour. The km value was calculated to be 1.2mg of CMC/㎖.

불소방출성 콤포짓트 레진계 수복재의 특성

김상훈,백병주,김재곤,양연미,박정렬 大韓小兒齒科學會 2008 大韓小兒齒科學會誌 Vol.35 No.3

본 연구에서는 구강 환경과 유사한 조건에서 불소방출성을 보이는 콤포짓트 레진계 수복재의 내구성과 불소방출성을 조사하기 위해 4종의 콤포머와 1종의 불소방출성 콤포짓트 레진을 실험재료로 선택하고 5℃와 55℃ 수중에서의 열순환 처리 후의 인장강도, 열순환 처리 후 칫솔에 대한 작용력 1.5N으로 100,000회 칫솔질을 시행하였을 때의 표면조도 및 불소치약 칫솔질 후 37℃ 수중에서의 불소이온 용출 양상을 조사한 결과 다음과 같은 결론을 얻었다. 1. 인장강도는 TC(Tetric^(ⓡ) Ceram)군에서 32.3 MPa, CF(Compoglass F)군에서 16.8 MPa이고, TC군과 DF(Dyract^(ⓡ) flow)군 및 CF군에서 유의한 차이를 보였다(P<0.05). 2. 칫솔질 마모시험 후의 표면조도 Ra는 TC군에서 0.287, FT(F2000)군에서 1.516이고, FT군과 나머지 시험군 사이에 유의한 차이를 보였다(P<0.05). 3. 칫솔질 마모시험 후의 표면에서는 필러의 돌출과 탈락 양상이 관찰되었다. 4. 불소치약 Perio Alpine Herb로 칫솔질 한 후 콤포머는 초기에 높은 용출을 보인 후 시간이 경과하면서 용출량이 감소하는 양상을 보였지만, 불소방출성 콤포짓트 레진의 TC군에서는 초기단계부터 낮으면서도 지속적인 용출을 보였다. 5. 불소치약 Perio Alpine Herb로 칫솔질 한 후 1시간이 경과하였을 때의 불소이온 용출량은 CF군에서 2.064μg/cm², TC군에서 0.1119μg/cm²이고, CF군의 용출량이 나머지 시험군에 비해 유의하게 높은 값을 보였다(P<0.05). The objectives of this study were to examine the properties of fluoride-releasing resin composite restorative materials. Four commercially available compomer materials (Compoglass F: CF, Dyract^(ⓡ) AP: DA. Dyract^(ⓡ) flow:DF, F2000: FT) and one fluoride-releasing composite resin (Tetric^(ⓡ) Ceram: TC) were selected as experimental materials. Rectangular-shaped tensile test specimens were fabricated in a teflon mold giving 5 mm in gauge length and 2 mm in thickness. Disk-shaped specimens were fabricated in the split teflon mold with diameter of 15mm and thickness of 1 mm. After curing for an hour, specimens were immersed in deionized water at 37℃±1℃ for 30 days. All specimens were thermocycled for 10,000 cycles with 15 seconds of dwelling time in each 5℃ and 55℃ water baths. Toothbrush abrasion test was conducted under a load of 1.5 N and the abraded surfaces were examined with surface roughness tester (SV-3000, Mitutoyo Co, Japan) and SEM (JSM-5800, JEOL, Japan). Fluoride recharging was done by toothbrushing for 3 min. using a fluoride toothpaste (Perio Alpine Herb, LG Household & Health Care, Korea). The results obtained were summarized as follows; 1. The highest tensile strength value of 32.3 MPa was observed in TC group and the lowest value of 16.8 MPa was observed in CF group. The tensile strength of TC group was significantly higher than those of CF and DF groups (P<0.05). 2. The lowest Ra value of 0.287 was observed in TC group and the highest value of 1.516 was observed in FT group. The Ra value of FT group was significantly higher than other groups (P<0.05). 3. The abraded surfaces revealed the increase of surface roughness due to the protrusion and missing of filler particles. 4. The release of fluoride of compomers after tooth brushing by Perio Alpine Herb was initially large and then followed by small and continuously. But it remains small and constant in fluoride-releasing composite resin of TC. 5. The highest value of fluoride release after toothbrushing by Perio Alpine Herb was 2.064 μg/cm² in CF group and the lowest value was 0.119μg/cm² in TC group. The amount of fluoride release of CF group was significantly higher than other groups (P<0.05).

하악 전치부에 발생한 과잉치 : A CASE REPORT

김성희,박종하,양연미,김재곤,백병주 大韓小兒齒科學會 2004 大韓小兒齒科學會誌 Vol.31 No.1

과잉치는 유치열에서 0.3-0.8%, 영구치열에서 1.0-3.5% 정도로 발생하며, 2:1로 남자에게 호발, 9:1로 상악에서 호발한다. 그 중 하악 전치부에서 발생하는 빈도는 전체 과잉치중에서 2-4%의 매우 낮은 빈도를 보인다고 보고되었다. 과잉치가 계속 존재할 경우 나타날 수 있는 합병증으로서 치간이개, 인접한 정상치아의 맹출장애, 치관의 형성이상, 인접치의 치근흡수, 함치성 낭종 등을 들 수 있으며, 치열 발육 중인 어린이의 경우 성장 중임을 감안하여 바람직한 교합유도를 위한 정확한 진단과 함께 적절한 처치가 필요하다. 본 증례는 전복대학교병윈 소아치과에 내원한 6세 환아의 하악 전치부에서 발견된 양측성 매복 과잉치로서 그 중 한개는 영구치와 융합된 경우를 보고하는 바이다. Supernumerary tooth describes an excess of tooth number, which are found in primary dentition with 0.3-0.8%, permanent dentition with 1.0-3.5% prevalence. Their frequency is about 2:1 (male vs female) and 9:1 (maxilla vs mandible). However, occurrence is very rare in the incisor region of the mandible. We need a early diagnosis and appropriate treatment plan because of possibility of diastema, eruption failure, displacement, rotation of the associated permanent teeth, root resorption, dentigerous cyst, with presence of the supernumerary teeth. This is a case report about two impacted supernumerary teeth found in madibular anterior region of 6 years old girl. One was extracted and another was retained because of fusion with permanent central incisor on the labial surface.

치과 방문 시 어린이와 부모의 치과 불안도의 상관 관계

김성희,백병주,김재곤,양연미,권병우 大韓小兒齒科學會 2005 大韓小兒齒科學會誌 Vol.32 No.2

어린이에게 있어서 치과 불안의 문제는 오랫동안 환자 행동조절의 문제로서 여겨져 왔으며 이러한 문제로 인해 치료 시의 비협조도, 치료 악속 취소 및 회피 둥이 발생할 수 있다. 따라서 치과의사 및 치과 팀에게 가능한 한 빨리 어린이의 치과 불안을 인지하여 적절히 대처할 것이 요구 되어진다. 한편, 부모의 치과 불안이 그들의 아이의 치과 불안과 치료 협조도에 영향을 줄 수 있음이 이전의 여러 연구들로부터 언급 되어지고 있다. 또한 치과 방문 결정의 주체가 어린이라기보다는 부모임을 고려할 때, 부모와 어린이 사이의 치과 불안도의 관계 규명이 중요하다 하겠다. 본 연구는 전북대학교 병원 소아치과에 내원한 3~10세(평균 연령 5.27세, 표준 편차 2.172세)의 어린이 78명(남아 45명, 여아 33명)과 그들의 부모 78명을 대상으로 하였으며, 치과 치료 전의 어린이의 치과 불안도 평가를 위해 Venham Picture Scale을, 부모의 치과 불안도 평가를 위해 Corah's dental anxiety scale을 사용하여 두 값을 비교하였다. 또한 어린이의 치료 시 협조도, 기질, 성별, 나이, 부모의 교육 정도를 평가하여 치과 불안도와 비교하였다. 이에 다음과 같은 결론을 얻었다. 1. 어린이의 치과 불안도와 부모의 치과 불안도 사이의 상관 분석 및 회귀분석에서 상호 관계성이 존재하였다(P<0.02). 2. 어린이의 치과 불안도와 치료 협조도사이의 상관 분석 및 교차 분석에서 음의 상호 관계를 나타내었다(P<0.001). 3. 어린이의 치과 불안도와 기질에 관한 Student's t-test에서 낮은 불안도와 높은 불안도 그룹의 네 가지 기질 평균 점수비교 시, 낮은 불안도 그룹에서 모두 약간 낮은 평균 점수를 보였으나 통계학적 유의차는 없었다(P>0.1) 4. 어린이의 치과 불안도와 어린이의 성별, 나이에 관한 Student's t-test에서, 여아에서 높은 불안도, 3~6세의 어린 그룹에서 높은 불안을 보였다(P<0.001). 5. 부모의 치과 불안도와 부모의 학력에 관한, Student's t-test에서, 대학교육을 받지 않은 저학력 부모 그룹에서 더 높은 불안도를 보였으나 통계학적 유의차는 없었다(P>0.1). In children, dental anxiety of dental treatment has been recognized as a source of problems in patient management for many years. Dental anxiety can be causes of negative cooperation, cancel and avoid of dental treatment. Therefore, dentist and dental team should recognize of child's dental anxiety as early as possible and manage appropriately. In previous studies, it is reported that parental dental anxiety affect dental anxiety and cooperation of their child. And it is parental decision which results in a child's visit to the dentist, rather than a child's decision in most cases. Therefore, it is important to identify the relationship of dental anxiety between child and parent. We estimated child's dental anxiety before dental treatment using Venham Picture Scale that is useful even a very young child and parental dental anxiety using Corah's dental anxiety scale. Then, two values above were compared. Child's cooperation, temperament, sex, age, parental education were estimated and compared with dental anxiety, too. The results were as follows: 1. There are positive relationship of dental anxiety between child and parent with the correlation analysis (P<0.02). 2. There are negative relationship of child's dental anxiety and child's cooperation with the correlation and regression analysis (P<0.001). 3. Low anxiety group has lower mean value of four temperament item with the Student's t-test. But, there is no statistical differences (P>0.1). 4. Girl and younger group have higher mean value of dental anxiety than boy and older group with the Student s t-test (P<0.001). 5. Low educated parents have higher mean value of dental anxiety than high educated parents with the Student s t-test (P>0.1).

상호작용적인 코스웨어를 위한 다중매체 저작도구 설계에 관한 연구

변상용,양창우,강명주 제주대학교 1993 논문집 Vol.37 No.-

. This paper deals with design of integrated authoring tool which supports multimedia. Multimedia authoring tools must have some functions such as programming supporting for courseware to help teaching design, user interface for multimedia and system expansion, usability, and friendliness. To satisfy these functions, we decide objects into text, graphics, image, sound, moving picture, animation, interaction objects, and construct object editor and object processor for each medium. We also construct interaction processor which includes internal variables and function, and supports couseware interactions. We use icons and menus for user interface, and for the usability and friendliness, it is developed with Microsoft Windows.

소아의 최대개구량에 관한 연구

백병주,김상훈,양연미,김재곤 大韓小兒齒科學會 2001 大韓小兒齒科學會誌 Vol.28 No.4

최근에 측두하악장애(Temporomandibular Disorder, TMD)는 해마다 증가하는 경향을 보이고 있다. 측두하악장애는 저작근, 측두하악관절 및 그와 관련된 구조물의 많은 임상증상을 포함하는 포괄적인 용어이다. 측두하악장애로 치과에 내원하는 환자는 여성이 많으며, 각 연령별 분포에서 보면 10대 후반에서 20대 후반에 호발한다. 그러나 최근에는 호발연령이 낮아지는 경향을 보이고 있다. 이에 측두하악장애의 조기진단의 필요성이 요구되어지며, 본 논문에서는 진단의 한 방법으로 간편하면서 쉽게 시행할 수 있는 최대개구량을 측정하였다. 최대개구량에 관한 여러 보고가 있지만, 소아기의 전 연령을 대상으로 광범위하게 조사된 보고는 희귀하다. 이에 저자는 4세부터 13세까지 1775명의 어린이를 대상으로 최대개구량을 측정하였으며, 최대개구량과 연련, 신장, 체중에 관한 상관관계를 조사하여 악관절장애 진단의 기초적인 참고자료로 이용하고자한다. 본 연구에서는 4세에서 13세까지의 1775명(남자943명, 여자832명)을 대상으로 최대개구량과 연령, 신장, 체중의 상관관계에 관한 비교분석을 시행하여 다음의 결론을 얻었다. 1. 4세에서 12세까지의 연령군중 4세, 8세, 12세의 평균 최대개구량을 보면 남자의 경우 각각 40.16mm, 47.32mm, 50.54mm였고, 여자의 경우 각각 39.79mm, 44.85mm, 48.09mm였다. 2. 연령이 증가함에 따라 최대개구량은 증가하는 경향을 보였고, 남자가 여자보다 큰 측정치를 보였다. 3. 신장이 증가함에 따라 최대개구량은 증가하는 경향을 보였으며, 105cm 이상 115cm 미만을 제외하고는 남자가 여자보다 큰 측정치를 보였다. 4. 체중이 증가함에 따라 최대개구량은 증가되는 경향을 보였으며, 모든 군에서 남자가 여자보다 큰 측정치를 보였다. 5. 최대개구량과 연령, 신장, 체중간의 관계에서 유의한 순상관 관계를 보였으며, 신장이 가장 높은 상관성을 보였다. Recently, tempormandibular disorder(TMD) shows an tendency to increase every year. TMD is a collective term embracing a number of clinical problems that involve the masticatory musculature, temporomandibular joint(TMJ) and associated structures, or both. TMD, viewed in distribution of age, often occurred from late teens to late twenties. But recently, the age of occurrence tends to be lower. Accordingly, early diagnosis of tempormandibular disorder is very important. In this study, we measured the maximum mouth opening which is simple and easy to carry out as a way of TMD diagnosis. In this study, the maximum mouth opening was examined for 1,775 children from 4 to 12 years of age. We compared the relationship between the maximum mouth opening with the age, height, and weight. The results obtained were summarized as follows; 1. The mean maximum mouth openings of 4, 8, and 12 year of age were respectively 40.16mm, 47.32mm, 50.54mm for male, 39.79mm, 44.85mm, 48.09mm for female. 2. The maximum mouth opening increased with age, and the values were greater in male than in female. 3. The maximum mouth opening increased wit height, and the values were greater in male than in female except between 105cm and 115cm. 4. The maximum mouth opening increased with weight, and the values were greater in male than in female. 5. The correlation between the maximum mouth opeing with the age, height, and weight was all significant and height showed the highest correlation.

신체화장애 환자의 스트레스 대처방식 및 심리적 특성

이주연,이무석,윤진상,양종철,문지웅,정해원,은성종 大韓神經精神醫學會 2006 신경정신의학 Vol.45 No.6

Objectives : The purpose of this study was to investigate the stress coping strategies and psychological charactehstics, such as combined psychopathology and tendency of symptom interpretation, in patients with somatization disorder. Methods : Thirty patients meeting the criteria of DSM-IV somatization disorder were compared with thirty controls. We evaluated the subjects using Symptom Checklist-90-Revised (SCL-90-R), Somato-Sensory Amplification Scale (SSAS), Symptom Interpretation Questionnaire (SIQ), and The Ways of Stress Coping Questionnaire (SCQ). Independent t-test and Pearson correlation analysis were used. Results : From the results of SCL-90-R subscales, the scores of somatization, obsession-compulsion, depression, anxiety, and psychoticism were significantly higher in patients with somatization disorder than nonnal controls. Somatization disorder patients had greater amplification of physical sensation in SSAS and significantly higher score in physical interpretation of SIQ compared with psychological or environmental interpretation, In the SCQ of somatization disorder patients, we observed generallylower levels of total coping scores than the control group and significant positive correlation between passive coping style of SCQ and psychological interpretation of SIQ. Conclusion : These results show that patients with somatization disorder have various psychopathology, greater amplification of physical sensation, physical interpretation tendency of symptoms, and insufficient copying strategy.

골종양의 병리조직학적 검색

이상원,이주희,야문호 慶熙大學校 醫科大學 1987 慶熙 醫大 論文集 Vol.12 No.1