• Title/Summary/Keyword: Internal contour

Search Result 87, Processing Time 0.023 seconds

Finite Element Stress Analysis in Supporting Bone according to Crest Module Shape of Fixture in Internal Connection System (내측연결 시스템에서 임플란트 고정체의 경부 형태에 따른 지지골에서의 유한요소 응력분석)

  • Park, Young-Nam;Kim, Hee-Jung;Oh, Sang-Ho;Chung, Chae-Heon
    • Journal of Dental Rehabilitation and Applied Science
    • /
    • v.22 no.1
    • /
    • pp.55-74
    • /
    • 2006
  • The external contour of an implant can have significant effects on the load transfer characteristics and may result in different bone failure rates for different implant system. The purpose of this study was to investigate the effects of crest module shape and occlusal load direction on bone failure modes of five commercially available dental implant systems. Five different implant systems with internal connection; ITI (Model 1), Astra (Model 2), Bicon (Model 3), Friadent (Model 4), and Paragon (Model 5), comparable in size, but different in thread profile and cest module shapes, were compared using the finite element method. Conclusively, in the internal connection system of the implant-abutment connection methods, the stress-induced pattern at the supporting bone according to the abutment connection form had differenence among them, and implants with narrowing crestal module cross-sections at the top of the cortical bone created more favorable load transfer characteristics in this region. But it is considered that the future study is necessary about how this difference in the magnitude of the stress have an effect on the practical clinic.

Observation of Semi-diurnal Internal Tides and Near-inertial Waves at the Shelf Break of the East China Sea

  • Park, Jae-Hun;Lie, Heung-Jae;Guo, Binghuo
    • Ocean and Polar Research
    • /
    • v.33 no.4
    • /
    • pp.409-419
    • /
    • 2011
  • Semi-diurnal internal tides and near-inertial waves are investigated using moored current meter measurements at four sites along the shelf break of the East China Sea during August 1987 and May-June 1988. Each mooring is equipped with four current meters spanning from near surface to near bottom. Spectral analyses of all current data reveal dominant spectra at the semi-diurnal frequency band, where the upper and lower current measurements show out-of-phase relationship between them with significant coherences. These are consistent with typical characteristics of the first-mode semi-diurnal internal tide. Strong intensification of the near-bottom baroclinic currents is observed only at one site, where the ratio of the bottom slope to the slope of the internal-wave characteristics at the semi-diurnal frequency is close to unity. An energetic near-inertial wave event is observed during the first half of May-June 1988 observation at two mooring sites. Rotary spectra reveal that the most dominant signal is clockwise rotating motion at the near-inertial frequency band. Upward phase and downward energy propagations, shown in time-depth contour plots of near-inertial bandpass filtered currents, are confirmed by cross correlations between the upper- and lower-layer current measurements. The upward-propagating phase speed is estimated to be about 0.13 cm $s^{-1}$ at both sites. Significant coherences and in-phase relationships of near-inertial currents at the same or similar depths between the two sites are observed in spite of their long distance of about 110 km.

Effect of the speed sintering schedule on the marginal and internal gaps of multi-layered zirconia prothesis (급속소결이 다층 지르코니아 치과보철물의 변연 및 내면 적합도에 미치는 영향)

  • Kim, Se-Yeon;Kim, Jae-Hong
    • Journal of Technologic Dentistry
    • /
    • v.44 no.1
    • /
    • pp.1-7
    • /
    • 2022
  • Purpose: The purpose of this in vitro study is to evaluate the clinical acceptability of the marginal discrepancies and internal spacing of multi-layered zirconia prothesis by speed sintering. Methods: The two specimen types come from the same manufacturer but differ in the ingredients in layered zirconia and indication, that is anterior and posterior. The designs of both specimens were full contour crowns, and a total of 20 pieces were repeatedly fabricated, 10 for each group. The specimens were divided into two subgroups (n=10) and sintered with various total times (4 hours, 8 hours) at the maximum temperature (1,530℃). The gap between the two groups of multi-layered zirconia prostheses was measured using a silicone replica technique of 2D analysis method. The independent sample t-test was then used to compare and analyze the data obtained from the two groups (α=0.05). Results: The marginal and internal gap was superior in the 8-hour compared to the 4-hour group, and the results exhibited significant differences (p<0.05). All specimens showed that using the speed sintering schedule does not exceed the clinically permitted value of 120 ㎛, meaning zirconia prothesis using the speed sintering was adequate. Conclusion: The sintering condition is shown to affect the marginal and internal gaps of multi-layered zirconia restoration.

The Use of the Internal Mammary Vessel Perforator as a Recipient Vessel for Free TRAM Breast Reconstruction (유리 횡복직근피판술을 이용한 유방의 재건에서 수혜부 혈관으로 내유방혈관 천공지의 사용)

  • Park, Myong-Chul;Lee, Jung-Hoon;Chung, Jae-Ho;Lee, Sung-Hun
    • Archives of Reconstructive Microsurgery
    • /
    • v.10 no.2
    • /
    • pp.105-110
    • /
    • 2001
  • Breast reconstruction is an aesthetically critical procedure and should be peformed to match the opposite breast in shape, contour, and position. Many methods were introduced to reconstruct the breast with autogenous tissue. But, free tissue transfer for breast reconstruction has become common method. The transverse rectus abdominis myocutaneous flap technique has been a widely accepted method of breast reconstruction after mastectomy, since the first introduction of free abdominoplasty flap in 1979. In breast reconstruction with a free flap the selection of suitable recipient vessels remains one of the most critical decision for surgeon. The most common recipient site for free flap breast reconstruction is the axillar system. But, the use of the axillary system as a recipient site limits flap movement and flexibility in breast shaping. The use of internal mammary vessels as a recipient site be able to achieve ideal breast symmetry, but that technique require the rib resection. The selection of suitable recipient vessels is most important for successful free tissue transfer. We have performed breast reconstruction with TRAM flaps anastomozed to the internal mammary vessel perforator. We came to the conclusion that this vessel perforator is useful as a recipient site in cases of immediate breast reconstruction with free TRAM flap.

  • PDF

A Study on Minimal Expression Techniques Depicted in Modern Fashion Design (현대패션에 나타난 최소표현기법에 관한 연구)

  • 김은덕;김민자
    • Journal of the Korean Society of Costume
    • /
    • v.24
    • /
    • pp.157-176
    • /
    • 1995
  • The purpose of this treatise is to study external form and internal meaning of minimal expression fashion which appeared as a major stream in modern fashion trends to understand one aspect of modernism in fashion and also to gain insight into internal value of human beings through fashion. The results can be summarized as follows : Firstly , minimalism is a trend in art attempting to seek essence of the object by presenting simple and disciplined expressions by minimal formative means and minimal production process. Secondly, minimal expression in fashion means seeking simplicity an dpurity by using minimum design elements and minimal productive process. Thirdly, external from of minimal expression fashion can be created through application of following minimal expression techniques. 1. Minimal expression techniques in terms of line mean smooth curve flowing along body contours, straight lines of diagonal lines into desciplined silhouette or rendering internal contour lines. 2. Minimum expression techniques in terms of forms mean forms of smooth curves flowing along boyd or forms with simple geometric forms from qualitative aspects, In terms of volume it means quest for essence of pure body itself by revealing body as it is by minimizing the size of dress or its area and herein is contained using simple geometric pattern or utilizing textiles without any patterns.3. Minimal expression techniques by colors mean simple colors such as primary colors, colors without clear distinctions or natural colors and in terms of quantity it means quest for one color within one item of dress or combination of each items when getting dressed. 4. Minimal expression techniques in terms of fabrics mean fabrics with simple surfaced. In terms of quantity it means quest for essence of tight fitting thin textiles to human body or using transparent materials to human body thus exposing body contours as it is. 5. Minimal expression techniques in terms of productive process mean minimizing process of tailoring , sewing or ornamenting and seeking for simplicity and purity. 6. Minimal expression techniques in terms of manufacturing process mean selection of technique conveying simple image with disciplined simple image. Fourthly, minimal expression fashion with external expression as mentioned in the above lay body-priority style and its internal meaning can be asummed as quest for essence and purity of human body.

  • PDF

Correction of Fibrous Dysplasia through Malarplasty without Internal Fixation

  • Oh, Young-Il;Yoon, Kyu-Ho;Park, Kwan-Soo;Cheong, Jeong-Kwon;Bae, Jung-Ho;Lee, Kwon-Woo;Han, Jung-Gil;Shin, Jae-Myung;Baik, Jee-Seon
    • Maxillofacial Plastic and Reconstructive Surgery
    • /
    • v.35 no.5
    • /
    • pp.337-341
    • /
    • 2013
  • Fibrous dysplasia is a chronic developmental disease of the skeleton involving formation of immature bone. Involvement of facial bones can result in deformation of facial contour. Prominent cheek area is often treated with malarplasty, which has a variety of modifications, depending on the surgeon's preference. The authors report on a case of polyostotic fibrous dysplasia in which the patient's right cheek had a prominent appearance. The prominence was corrected with malarplasty without internal fixation. The soft nature of bone involved in fibrous dysplasia could provide greater flexibility for modification of the traditional surgery.

Numerical simulation on starting transients in supersonic exhaust diffuser; evolution of internal shock structures with different initial cell pressures (초음속 디퓨져 시동 과정에 관한 수치 모사; 초기 진공도에 따른 디퓨져 내부 충격파 구조의 발달 과정)

  • Park Byung-Hoon;Lim Ji-Hwan;Yoon Woong-Sup
    • Proceedings of the Korean Society of Propulsion Engineers Conference
    • /
    • 2005.11a
    • /
    • pp.46-55
    • /
    • 2005
  • For the sea-level performance test of rocket motor designed to operate in the upper atmosphere, ejectors with no induced secondary flow are generally used, which serves dual purposes of evacuating the test cell and performing as a supersonic exhaust diffuser (SED). The main concern of this research is to simulate starting transients in order to visualize evolution of internal shock structures in SED with different initial cell (vacuum chamber) pressures. RANS code with low Reynolds $k-\varepsilon$ turbulence model was employed for these computations. Numerical results were compared with the pressure measurements previously performed [Proceedings of 2004 Annual Conference, KIMST], and showed good agreements with pressure-time history of measured data. In the case of low vacuum chamber pressure, abrupt impingement of the under-expanded supersonic jet from the nozzle onto the diffuser wall was observed, whereas initial impingement point was located downstream and moved slowly upstream in the case of non-vacuum chamber pressure. In spite of initially dissimilar evolution of shock structures, iso-mach contour revealed that the steady shock structures had little difference except the location of flow separation and normal shock.

  • PDF

Minimally Invasive Coronary Artery Bypass without Extracorporeal Circulation - One case report - (심폐바이패스없이 제한적 전흉부개흉술로 시행한 관상동맥우회술 1례)

  • 서필원;김삼현;이상민;김영권;박이태
    • Journal of Chest Surgery
    • /
    • v.29 no.11
    • /
    • pp.1263-1266
    • /
    • 1996
  • We have experienced a case of coronary artery bypass surgery without extracorporeal circulation through limited anterior thoracotomy. The lesion was a single vessel disease involving the take off of the left anterior descending artery(LAD) which showed tubular lesion with irregular contour and eccentric stenosis of more than 95% luminal narrowing. Percutaneous transluminal coronary angioplasty(PTCA) seemed to have moderate success rate and moderate complication rate. A segment of left internal mammary artery(LIMA) from the second rib down to the sixth rib was harvested through the bed of resected fourth costal cartilage. Anastomosis between LIMA and LAD was performed under beating condition. The patient was extubated in the operation room and showed excellent postoperative course without complications. The coronary angiography on the postoperative 7th day revealed good patency at the anastomosis site.

  • PDF

Optimum Shoulder Height Design using Non-dimensional Shape Variables of Ball Bearing (볼 베어링의 무차원 형상변수를 이용한 최적 턱 높이 설계)

  • Choi, DongChul;Kim, TaeWan
    • Tribology and Lubricants
    • /
    • v.35 no.1
    • /
    • pp.37-43
    • /
    • 2019
  • This paper presents an optimization method to determine the shoulder height of an angular contact ball bearing by 3D contact analysis using nondimensional-shaped variables. The load analysis of the ball bearing is performed to calculate the internal load distributions and contact angles of each rolling element. From the results of bearing load analysis and the contact geometry between the ball and inner/outer raceway, 3D contact analyses using influence function are conducted. The nondimensional shoulder height and nondimensional load are defined to give the generalized results. The relationship between the shoulder height and radius of curvature of the shoulder under various loading conditions is investigated in order to propose a design method for the two design parameters. Using nondimensional parameters, the critical shoulder heights are optimized with loads, contact angles, and conformity ratios. We also develop contour maps of the critical shoulder height as functions of internal loads and contact angles for the different contact angles using nondimensional parameters. The results show that the dimensionless shoulder height increased as the contact angle and dimensionless load increased. Conversely, when the conformity ratio increased, the critical shoulder height decreased. Therefore, if the contact angle is reduced and the conformity ratio is increased within the allowable range, it will be an efficient design to reduce the shoulder height of ball bearings.

A Study on the Estimation of Temperature in Track Components due to Hystresis Loss. (히스테리시스 손실에 의한 괘도부품의 온도 추정에 관한 연구)

  • Kim, H.J.;Kim, B.T.;Baek, W.K.
    • Journal of Power System Engineering
    • /
    • v.5 no.3
    • /
    • pp.48-55
    • /
    • 2001
  • In many applications. rubber components undergo dynamic stresses or deformations of fairly large magnitude. Since rubbers are not fully elastic, a part of the mechanical energy is converted into heat due to the hysteresis loss. Heat generation without adequate heat dissipation leads to heat build up. i. e. internal temperature rise. The purpose of this paper is to predict temperature rise caused by the hysteresis loss, in a rubber pad subjected to complex dynamic deformation. In this unsteady thermal analysis, the temperature distributions of track components are displayed in contour shapes and the temperature variations of some important nodes are represented graphically with respect to the running time of the tank.

  • PDF