Search Result of "Aroonjarattham, P"

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ที่มา:วิทยาสารเกษตรศาสตร์ สาขา วิทยาศาสตร์

หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Effect of Mechanical Axis on Strain Distribution after Total Knee Replacement)

ผู้เขียน:ImgPanya Aroonjarattham, ImgKitti Aroonjarattham, Imgนายชาคริต สุวรรณจำรัส, อาจารย์

สื่อสิ่งพิมพ์:pdf

Abstract

A total knee replacement is one of the most successful orthopedic procedures to enable the patient’s return to a normal, active lifestyle. The angle of the mechanical axis depends on the surgeon’s decision, which effects the strain distribution on the femoral bone and may lead to a fracture of the femur . This study evaluated the equivalent total strain on the femoral shaft under daily activities using various models of the lower extremity with a varus knee deformity and the lower extremity with a total knee prosthesis, which was inserted at five different angles—0?, 3? valgus, 5? valgus, 3? varus and 5? varus. The results showed that the insertion of a total knee replacement in the case of a bowleg helped to reduce the equivalent total strain on the bone. The position of the prosthesis with a 3? valgus angle produced less strain distribution on the femoral bone. From the results, the mechanical axis affected the risk of the bone fracture. Considering the plastic spacer, it was found that there was an increase in the von Mises stress in the medial side of the model leg with a knee prosthesis of 3? valgus .

Article Info
Agriculture and Natural Resources -- formerly Kasetsart Journal (Natural Science), Volume 048, Issue 2, Mar 14 - Apr 14, Page 263 - 282 |  PDF |  Page 

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ที่มา:วิทยาสารเกษตรศาสตร์ สาขา วิทยาศาสตร์

หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Diffusion Jet Flame Models Using Open Source Code CFD Software)

ผู้เขียน:Imgนายชาคริต สุวรรณจำรัส, อาจารย์, ImgPanya Aroonjarattham

สื่อสิ่งพิมพ์:pdf

Abstract

Open-source code software (OpenFOAM) based on computational fluid dynamics (CFD) was implemented and applied to simulate the diffusion of a jet flame. The large eddy simulation (LES) of the turbulence combustion model was written using the C++ language. The mixture fraction approach, an infinitely-fast chemistry assumption and radiative heat transfer were combined with this LES model. The finite volume method was performed to solve and simulate diffusion jet flame models under varying methane flow rates and environmental pressures. The results of the jet flame simulation comprising the percentage of maximum burning temperature, the heat release rate and oxygen from the oxygen fraction were defined to be the flame shape for validation with experiments. It was found that the flame length measured using the heat release rate from the results of simulations had the best agreement with the experiments. An average error of less than 5.84% was obtained by a comparison between the developed CFD model and the experiment when the CFD flame length was depicted by the heat release rate.

Article Info
Agriculture and Natural Resources -- formerly Kasetsart Journal (Natural Science), Volume 049, Issue 3, May 15 - Jun 15, Page 465 - 473 |  PDF |  Page 

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ที่มา:วิทยาสารเกษตรศาสตร์ สาขา วิทยาศาสตร์

หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Biomechanical Effect of Filled Biomaterials on Distal Thai Femur by Finite Element Analysis)

ผู้เขียน:ImgPanya Aroonjarattham, ImgKittiAroonjarattham, ImgManeerat Chanasakulniyom

สื่อสิ่งพิมพ์:pdf

Abstract

Giant cell tumors are frequently detected at the lower end of the distal femur. Surgery is the most effective treatment for these tumors. The experience of the surgeons determines the amount of bone removal containing the giant cell tumors (excision) and what biomaterials should be used for the bone replacement; however, the strength of the reconstructed bone has been a concern. Finite elements analysis was employed in this study to analyze the direction to fill and the appropriate quantity of biomaterial, namely polymethylmethacrylate (PMMA) or hydroxyapatite (HA), which was used to replace the bone. With PMMA replacement, increased quantities of PMMA replacement made the maximum von Mises stress nearly constant. The surgeon should fill the PMMA replacement from the lateral to the medial side to reduce the maximum von Mises stress on PMMA. With HA replacement from the lateral to the medial side, the maximum von Mises stress slightly increased when the biomaterials were added under walking conditions and were nearly stable when added under stair climbing conditions. However, HA replacement from the medial to the lateral side produced the highest maximum von Mises stress when three parts of biomaterial were added under both conditions. The surgeon should fill the HA replacement from the lateral to the medial side to minimize the maximum von Mises stress on the HA. In addition, finite elements analysis seemed to be a useful tool, combined with the surgeons’ experience to validate suitable biomaterial or an appropriate procedure for better results in bone surgery.

Article Info
Agriculture and Natural Resources -- formerly Kasetsart Journal (Natural Science), Volume 049, Issue 2, Mar 15 - Apr 15, Page 263 - 276 |  PDF |  Page 

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ที่มา:วิทยาสารเกษตรศาสตร์ สาขา วิทยาศาสตร์

หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Development of a Wear Testing Machine for Dental Crown Application)

ผู้เขียน:ImgPanya Aroonjarattham, Imgนายชาคริต สุวรรณจำรัส, อาจารย์, Imgเอกชัย ชัยชนะศิริ

สื่อสิ่งพิมพ์:pdf

Abstract

A three axes wear testing machine for a dental crown was developed for human tooth application. There were two main sections of the controllers: the application of an AC servomotor (Z-axis) for creating and controlling the force which is used in testing and the application of a step motor (X-axis and Y-axis) for creating and controlling the motion. This study aimed to compare the ability of the controlling force of the AC servomotor on two different surfaces—a smooth fl at surface and a dental crown surface. Three testing cases were considered at frequencies of 0.5, 0.75, and 1 Hz in a range of motion of 1 mm: 1) simulating the force of chewing (0–60 N) and the motion of a circular process, 2) simulating a constant force (60 N) of one way movement in a circular process and 3) simulating a constant force (60 N) of the reciprocating movement in a circular process. The machine was tested using a dental crown, which was made of zirconia, by simulating the force, the motion and the various conditions of the teeth in the oral cavity. The force which occurred in all three axes was measured by the load cell. According to the experiment, the AC servomotor was able to control the force exerted on two different surfaces with nearly similar results. The average force errors on the smooth surface and the dental crown surface were 13.70 and 13.82%, respectively. The root mean square errors of the smooth surface and the dental crown surface were 17.47 and 16.99, respectively.

Article Info
Agriculture and Natural Resources -- formerly Kasetsart Journal (Natural Science), Volume 047, Issue 5, Sep 13 - Oct 13, Page -  |  PDF |  Page 

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Researcher

ดร. ธัญญะ เกียรติวัฒน์, รองศาสตราจารย์

ที่ทำงาน:ภาควิชาวิศวกรรมเครื่องกล คณะวิศวกรรมศาสตร์ บางเขน

สาขาที่สนใจ:Applied Mechanics, Finite Element Analysis, Machine Design

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