• 대한기관식도과학회지
• /
• 제7권1호
• /
• pp.59-61
• /
• 2001

Lipomas is one of the most common benign neoplasm in the body, but only rarely occurs in the oral cavity We report here a case of a 49-year-old female with a lipoma of palatine tonsil. Microscopical examination revealed a stromal neoplasm composed of mature fat with the presence of a few thin and anastomosing fibrous septa. The surface epithelium was of nonkeratinizing stratified squamous type. There was the dense fibrous connective tissue between mature fat and surface epithelium. The histopathologic findings and literature on tonsillar lipoma is reviewed.

• Tribology and Lubricants
• /
• 제19권5호
• /
• pp.245-250
• /
• 2003

Water is known to playa crucial role on friction of moving parts in nanoscale contact. Little is, however, known about the tribological behavior of a solid surface that is covered with water adsorption layer. The objective of this study is to investigate the nanotribological behavior of the water layer in relation to water affinity of the surface and relative humidity. This paper presents an examination of the frictional behavior of water adsorption layer as 'confined liquid film'. It is shown that the friction is inversely proportional to the hydrophilicity of surface and relative humidity. On the other hand, friction of hydrophobic surface is not influenced by relative humidity. A model is proposed for the water-mediated contact in which it is shown that the water layer between two hydrophilic surfaces with high relative humidity behaves as a lubricant.

• 한국공작기계학회논문집
• /
• 제11권1호
• /
• pp.26-31
• /
• 2002

In this study an experimental investigation was conducted to find the grinding characteristics of ceramics, STD11 and STS304 materials. The grinding force and the microscopic observation of the workpieces were obtained in surface grinding. Grinding characteristics of ceramics were inspected through the microscopic examination the cutting force, and the surface roughness. It has been found that the finding force of ceramics is relatively low as compared to that of steels and that CBN wheel has an excellent performance. The surface roughness was measured according to the feedrate and the depth of out.

• Computers and Concrete
• /
• 제7권1호
• /
• pp.63-81
• /
• 2010

We present the shape determination method of 3-D reinforcement corrosion based on observed temperature on concrete surface. The non-destructive testing for reinforcement corrosion in concrete using a heat image on concrete surface have been proposed by Oshita. The position of the reinforcement of corrosion or the cavity can be found using that method. However, the size of those defects can not be precisely measured based on the heat image. We therefore proposed the numerical determination system of the shape for the reinforcement corrosion using the observed temperature on the concrete surface. The adjoint variable method is introduced to formulate the shape determination problem, and the finite element method is employed to simulate the heat transfer problem. Some numerical experiments and the examination for the number of the observation points are shown in this paper.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
• /
• pp.436-437
• /
• 2005

3-dimension object's feature measurement is used several industrial field to produce for examination of demanded high quality products by using optical measurement method. 3-dimension object's feature measurement is separated surface scanning and surface non-scanning. In this research, we illuminated interfero-pattern to object, it was constructed with Michelson interferometer by using laser is one of surface non-scanning method. And we extracted phase-map, it is one of featural measurement analysis of 3-dimensional object by using a phase shifting theory.

• 대한약학회:학술대회논문집
• /
• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
• /
• pp.236.1-236.1
• /
• 2003

Evaluation of solid surface properties is very important for formulation of solid dosage form, specially insoluble drugs. The contact angle of insoluble drugs was measured by the penetration rate into powder bed using Washburn equation and wicking method. From the measured contact angle data, the surface free energy value of pharmaceutical powders ${\gamma}$s was divided and analysized into the polar component, ${\gamma}$s$\^$p/ and the dispersion component, ${\gamma}$s$\^$d/. Furthermore, the data was interpreted for acid part, ${\gamma}$s$\^$+/ and base part, ${\gamma}$s$\^$$\square$/ of surface free energy. (omitted)

• Journal of Periodontal and Implant Science
• /
• 제27권3호
• /
• pp.575-584
• /
• 1997

The quality of periodontal instrument cutting edge is a basic element of effective root planing procedure. Using instruments, the sharp edge is changed into blunt or beveled edge. With the blunt instrument, the periodontal treatment can't be carried into accuracy and effective. The study on the wear of periodontal curet is insufficient, there are few publications about the change of sharpness of cutting egde after using instrument and a certen reports were published on the study of scanning electron microscope(SEM) examination. In this study, to declare the number of strokes for sharpening of instruments, the changes of cutting edge is measured by the clinical methods, tactile sensitivity examination and refraction light-white line test after scaling strokes and root planing strokes. SEM test was added for defined the changes of cutting edges. The 7/8 Gracey curets that have been never used was tested. Maxillary molars which were extracted from the School of Dental Medicine, Dankook University was used. Subjected teeth had attachment loss more than 6 mm in bucca-lingual surface and sufficient calculus of a band type in cervical area. The strokes of curet were executed 3, 5, 7, 9, 11, 13 times on scaling stroke and 10, 15, 20, 25, 30, 35 times on root planing stroke. A resident has periodontal experience over 3 years carried out the clinical examinations those tactile sensitivity examination and refraction light-white line test 5 times. The case there being tactile sensitivity certenly is 2, the case being felt tactile sensitivity is 1, and the case there not being tactile sensitivity is 0. The visual examination was recorded as following. The case that refracted white line is not recognised is 2, the case that uncerten is 1, and the case that acknowledged is 0. The results were obtained as follows. 1. After scaling strokes, the tactile sensitivity was reduced after 11 strokes and disappeared in 13 strokes. 2. In tactile sensitivity after root planing procedures, sensitivity was reduced after 25 strokes and disappeared in 35 strokes. 3. In case of visual examination, the detection of refracted white line was increased after 9 strokes of scaling procedures and the accuracy of wear wasn't showed after root planing procedures. 4. In SEM, metal projection was observed on new periodontal curet cutting edge and it was disappeared after scaling procedures. 5. In SEM, the cutting edge was showed changing linear into an aspect of the surface after 5 strokes of scaling procedures and 10 strokes of root planing procedures and showed beveled edge in 11 strokes of scaling procedures, 25 strokes of root planing procedures. The results of 3-type examination indicated that the sharpening of curet should be performed after 11 strokes of scaling procedures and 25 strokes of root planing procedures.

• Transactions on Electrical and Electronic Materials
• /
• 제3권4호
• /
• pp.10-15
• /
• 2002

Surface states of polydimethylsiloxane (PDMS) treated by plasma were investigated by the analysis by x-ray photoelectron spectroscopy (XPS) and surface voltage decay. Plasma treatment causes the silica-like(SiO$\_$x/, x=3∼4) oxidative layer, which is confirmed with XPS, and lowers surface resistivity from 1.78$\times$1014 Ω/square to 1.09$\times$10$\^$13/ Ω/square with increasing the plasma treatment time. By measuring the decay time constant of surface voltage, the calculated surface resistivity was compared with the value directly measured by a voltage-current method, so good agreement between two methods was obtained. It was observed that the plasma treatment led to decrease of the thermal activation energy of the surface conduction from 31.0 kJ/mol of untreated specimen to 21.8 kJ/mol. It is found that our results allow the examination of effects of plasma on electrical properties of PDMS.

• 한국치위생학회지
• /
• 제11권2호
• /
• pp.169-178
• /
• 2011

Objectives : This study was conducted to investigate the actual state of dental hygienist's behavior for infection control during dental practice and radiologic examination and to evaluate the dental hygienist's awareness of the importance of infection control in dental office. Methods : A survey on 218 dental hygienists was carried out. The respondents to complete a questionnaire were the dental hygienists who were in dental office on Gwang-ju area or attended complementary training conducted by the Seoul Branch of Korean Dental Hygienists Association in April 2010. The data were collected and analyzed with $x^2$ test, t-test, ANOVA using SPSS program. Results : The ratios of educational experience for infection control in dental practice and radiologic examination room accounted for 87.6% and 30.3% respectively. Behavior degree of mask-wearing in the dental practice and radiologic examination room were $4.60{\pm}0.70$ and $3.77{\pm}1.09$ respectively. Behavior degree of glove-wearing in the dental practice and radiologic examination room were $4.40{\pm}0.91$ and $3.68{\pm}1.17$ respectively. In case of the relation between educational experience and behavior degree in mask-wearing or glove-wearing, there was no significant difference in the performance of mask or glove wearing during dental practice, and mask-wearing during radiologic examination. However, there was a significant difference (p<0.05) in the performance of glove-wearing during radiologic examination, which revealed that behavior degree between the respondents having educational experience and the others no having it were $3.92{\pm}1.19$ and $3.58{\pm}1.14$ respectively. The surface disinfection control for radiation and protective equipments used in radiologic examination room was done by occasional needs without premeditated schedules. Conclusions : The result of this study shows lower behavior degree during radiologic examination compared with one during dental practice. We suggest that there are needs to raise the awareness of infection control and to improve infection control behavior, and through this study, the importance of education was verified.

• 비파괴검사학회지
• /
• 제35권1호
• /
• pp.52-60
• /
• 2015

원자력발전소에는 탄소강과 스테인리스강 용접을 위해 alloy600 용접재를 적용한 이종금속용접부가 다수 존재하며, 전 세계적으로 이종금속용접부에서 결함 발생 보고가 지속되고 있다. 주기적인 건전성 평가를 위해 이종금속용접부 초음파검사 일반절차서 (KPD-UT-10)를 적용하여 검사를 수행하고 있으며, 검사절차서에서는 탐촉자와 검사체 표면 사이의 간격을 최대 1/32"(0.8mm) 이내로 제한하고 있다. 국내의 일부 이종금속용접부는 테이퍼진 형상과 불규칙한 표면 형상을 가지고 있어, 가변형 위상배열초음파기술을 적용하여 검사 신뢰성을 높이고자 본 연구를 수행하였다. 연구 결과, 검사체 표면이 불규칙한 시편 내부의 인공결함에 대한 검출이 양호하였고, 이를 통해, 가변형 위상배열초음파기술의 현장 적용 가능성을 확인하였다.