• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제18권3호
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• pp.257-268
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• 2014

The objective of the present study is to investigate thermal diffusion and radiation effects on unsteady MHD flow past a linearly accelerated vertical porous plate with variable temperature and also with variable mass diffusion in presence of heat source or sink under the influence of applied transverse magnetic field. The fluid considered here is a gray, absorbing/emitting radiation but a non-scattering medium. At time t > 0, the plate is linearly accelerated with a velocity $u=u_0t$ in its own plane. And at the same time, plate temperature and concentration levels near the plate raised linearly with time t. The dimensionless governing equations involved in the present analysis are solved using the closed analytical method. The velocity, temperature, concentration, skin-friction, the rate or heat transfer and the rate of mass transfer are studied through graphs in terms of different physical parameters like magnetic field parameter (M), radiation parameter (R), Schmidt parameter (Sc), Soret number (So), Heat source parameter (S), Prandtl number (Pr), thermal Grashof number (Gr), mass Grashof number (Gm) and time (t).

• 대한족부족관절학회지
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• 제10권2호
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• pp.201-206
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• 2006

Purpose: To evaluate the advantages of the antiglide plate fixation procedure for Danis-Weber type B lateral malleolar fractures of ankle compared to other methods of lateral plate fixation. Materials and Methods: We reviewed 70 cases that antiglide plate fixation and lateral plate fixation procedures were performed from Mar. 2001 through Mar. 2006. Of the total 70 cases, they were divided into two groups ; 22 cases were treated with the antiglide plate procedure (Group I) and 48 cases were treated with the lateral plate procedure (Group II). The results of the two groups were analyzed both radiographically and clinically using Ankle-Hindfoot scale of the American Orthopedic Foot and Ankle Society (AOFAS). Results: All fractures were healed at average of 8 weeks both radiographically and clinically. According to the Ankle-Hindfoot scale, all cases of Group I and 48 cases of Group II were above 80 points. 2 cases (9%) in Group I complained of peroneal tendinitis, while 19 cases (39%) in Group II showed skin irritation resulting from the screw or the plate. A total of 6 cases (27%) in Group I and 27 cases (55%) in Group II complained cosmetic problems. Conclusion: we concluded that the antiglide plate fixation for Danis-Weber type B lateral malleolar fractures is one of the good methods. But, further analysis will be need to find a solution for the peroneal tendinitis.

• 한국추진공학회지
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• 제10권2호
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• pp.87-94
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• 2006

모델 표면의 임의 영역에서 나타나는 이차원 전단응력의 분포를 측정하는 실험적 연구가 수행되었다. 오일막 위에 형성된 간섭영상을 이용한 이 측정법은 시험부 표면에 있는 오일막의 국소 기울기의 분포로부터 오일 윤활이론을 적용하여 전단응력의 분포를 얻어낼 수 있다. 평판 위에 수직으로 설치된 원형 실린더 전방의 박리영역에 이 측정법을 적용되어 전단응력의 이차원 분포가 측정되었다. 실험에서 관찰된 전단응력 분포는 유사한 유동조건에서 얻어진 과거 실험 및 수치결과와 비교분석 되었으며, 연구에서 전단응력 분포가 다른 연구결과들과 서로 잘 일치하고 있음이 관찰되어 이 측정법의 응용성이 검증되었다.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제20권4호
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• pp.355-374
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• 2016

This work is devoted to investigate heat and mass transfer effects on MHD natural convection flow past an inclined plate with ramped temperature numerically. The dimensionless governing equations for this investigation are solved by using finite element method. The effects of angle inclination, buoyancy ratio parameter, permeability parameter, magnetic parameter, Prandtl number, heat generation, thermal radiation, Eckert number, Schmidt number, chemical reaction parameter and time on velocity, temperature and concentration fields are studied and presented with the aid of figures. The effects of the pertinent parameters on skin friction, rate of heat transfer and mass transfer coefficients are presented in tabular form. The numerical results are compared graphically with previously published result as special case of the present investigation and results found to be in good agreement.

• 대한기계학회논문집
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• 제19권1호
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• pp.240-250
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• 1995

A CPM (computational preston tube method) was developed to measure wall shear stress in a transitional boundary layer on a flat plate using Preston tubes. Correlation for the displacement factor of Preston tubes was improved for a CPM to be used in the transitional boundary layer. The distribution of skin-friction coefficient was reasonably predicted in the uniform free stream of 3.1% turbulence intensity. Reasonable and accurate estimation of displacement factor of Preston tubes was found to be of crucial importance for the CPM, especially in the laminar boundary layer. The mean velocity profiles of the boundary layer on the plate were also measured and presented.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제22권4호
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• pp.241-251
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• 2018

The present study is carried out to examine the combined effect of heat absorption on flow model. The model consists of unsteady flow of a viscous, incompressible and electrically conducting fluid. The flow is along an impulsively started oscillating vertical plate with variable mass diffusion. The magnetic field is applied perpendicular to the plate. The fluid model under consideration has been solved by Laplace transform technique. The numerical data obtained is discussed with the help of graphs and table. The numerical values obtained for skin-friction have been tabulated. To shorten the lengthy equations in the solution some symbols have been assumed, which are mentioned in appendix. The appendix is included in the article as the last section of the manuscript.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제23권3호
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• pp.157-178
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• 2019

The present correspondence is conveyed on to consider the fascinating and novel characteristics of radiative hydromagnetic convective flow of a chemically reacting fluid over an exponentially accelerated inclined porous plate. Exact solutions for the fluid velocity, temperature and species concentration, under Boussinesq approximation, are obtained in closed form by the two term perturbation technique. The interesting parts of thermal dispersing outcomes are accounted in this correspondence. Graphical evaluation is appeared to depict the trademark direct of introduced parameters on non dimensional velocity, temperature and concentration profiles. Also, the numerical assortment for skin friction coefficient, Nusselt number and Sherwood number is examined through tables. The certification of current examination is confirmed by making an examination with past revelations available in composing, which sets a benchmark for utilization of computational approach.

• 대한두개안면성형외과학회지
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• 제19권2호
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• pp.114-119
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• 2018

Background: The ideal absorbable plating system should provide sufficient rigidity and then be absorbed within a timely manner. The Resorb-X has been recently developed as a plating system with a mixture ratio of 50:50 poly(D, L-lactide). Methods: We present seven of 121 patients who experienced delayed degradation with this absorbable plate. One hundred twenty-one patients with facial bone fracture underwent surgical treatment from March 2011 to March 2015, and rigid fixation was achieved with the Resorb-X. Results: Of 121 patients, seven (5.8%) developed complications at the surgical sites. Six of 102 cases underwent fixation of the infraorbital rim and one of 73 underwent fixation of the frontozygomatic buttress; the other sites of fixation did not develop delayed degradation. Foreign body granuloma developed at the earliest by postoperative 20 months and at the latest by postoperative 28 months (average, 23.5 months). Conclusion: We observed that the use of absorbable plates in incision sites or areas with thin skin can increase the possibility of delayed degradation. When performing surgery in these areas, the normal skin above the fixed location should be covered sufficiently.

• Structural Engineering and Mechanics
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• 제17권5호
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• pp.611-626
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• 2004

On the basis of a structural analysis of radial gate (i.e. Tainter gate), the current paper focuses on weight minimization according to the location of the arms on a radial gate. In spite of its economical significance, there are hardly any previous studies on the optimum design of radial gate. Accordingly, the present study identifies the optimum position of the support point for a radial gate that guarantees the minimum weight satisfying the strength constraint conditions. This study also identifies the optimum position for 2 or 3 radial arms with a convex cylindrical skin plate relative to a given radius of the skin plate curvature, pivot point, water depth, ice pressure, etc. These optimum designs are then compared with previously constructed radial gates. Local genetic and hybrid-type genetic algorithms are used as the optimum tools to reduce the computing time and enhance the accuracy. The results indicate that the weights of the optimized radial gates are appreciably lower than those of previously constructed gates.

• Steel and Composite Structures
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• 제46권2호
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• pp.263-277
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• 2023

Free vibration analysis of multi-directional porous functionally graded (FG) sandwich plate has been performed for two cases namely: FG skin with homogeneous core and FG core with homogeneous skin. Hamilton's principle was employed and the solution was obtained using Navier's technique. This theory imposes traction-free boundary conditions on the surfaces and does not require shear correction factors. The results obtained are validated with those available in the literature. The composition of metal-ceramic-based functionally graded material (FGM) changes in longitudinal and transverse directions according to the power law. Imperfections in the functionally graded material introduced during the fabrication process were modeled with different porosity laws such as evenly, unevenly distributed, and logarithmic uneven distributions. The effect of porosity laws and geometry parameters on the natural frequency was investigated. On comparing the natural frequency of two cases for perfect and imperfect sandwich plates a reverse trend in natural frequency result was seen. The finding shows a multidirectional functionally graded structures perform better compared to uni-directional gradation. Hence, critical grading parameters and imperfection types have been identified which will guide experimentalists and researchers in selecting fabrication routes for improving the performance of such structures.