• Archives of Plastic Surgery
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• v.35 no.6
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• pp.659-662
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• 2008

Purpose: Silicone gel sheet(SGS) is used for preventing and treating keloid or hypertrophic scars. Because the product is weak in tear strength and adherence, it requires several replacements, which requires high cost. As a solution for this problem, we developed a new silicone gel sheet, named as Scar Clinic, and confirmed its physical properties. Methods: Tensile strength, elongation rate, adhesiveness, and water vapor transmission rate were experimentally compared between the most commonly used SGS product and the Scar Clinic. Results: The newly developed SGS showed better results compared to the existed SGS in regards to tensile strength, elongation rate, adhesiveness, and water vapor transmission rate. Conclusion: The Scar Clinic showed higher durability and flexibility. It will be a useful product for treating scars clinically.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.275-280
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• 2008

To improve the durability of a hydrogen pressure vessel which is applied high-pressure, it needs the autofrettage process which induces compressive residual stress in the Aluminum liner. This study presents the elasto-plastic analysis to predict the behavior of structure accurately, and the Tsai-Wu failure criterion is applied to predict failure of pressure vessel of Aluminum liner and composite materials. Generally, plastic analysis is more complex than elastic analysis and has much time to predict. To complement its weakness, the AxicomPro(EXCEL program), applied radial return algorithm and nonlinear classical laminate theory (CLT), is developed for predicting results with more simple and accurate than the existing finite element analysis programs.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.6
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• pp.961-967
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• 2012

The metal is frequently used in the air-conditioner frame, which must have the durability from the various external environments, but has difficulties in being manufactured for many complex shapes. On the other hand, the plastic, used as a material of injection molding, enables the realization of various shapes and the mass-production of complex ones and leads low production cost. As the air-conditioner frame becomes increasingly complex and detailed, the plastic material is highlighted as an alternative for the frame. But the product molded by plastic with a complex shape might have a noise problem. Therefore this study attempts to design the product through TRIZ in order to reduce the noise of the air-conditioner with the frame of plastic material.

• International Journal of Automotive Technology
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• v.6 no.5
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• pp.507-511
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• 2005

Recently, many solution have been suggested to development of plastic products. Among many manufacturing technologies for plastic parts, the injection molding process is very attractive because of its low production cost and short cycle time. In this paper, the plastic ball seat of a ball joint, one of the essential components for automotive suspension or steering system, was studied to enhance its mechanical performance and durability by using PA66 that is reinforced polymeric plastic resin. But ball seat has some trouble in manufacture process. And strength of molded part is not enough to use. For the quality stabilization and reliability of injection molded parts, we designed the mold cavities through analytical simulation software and tested the mechanical performance for the injection molded ball-seat parts. After modification, tensile strength increases by about $13.5\%$. Strength and quality stabilization is improved.

• Archives of Plastic Surgery
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• v.50 no.2
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• pp.156-159
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• 2023

Breast implants whether used for cosmetic or reconstructive purposes can be placed in pockets either above or below the pectoralis major muscle, depending on clinical circumstances such as subcutaneous tissue volume, history of radiation, and patient preference. Likewise, cardiac implantable electronic devices (CIEDs) can be placed above or below the pectoralis major muscle. When a patient has both devices, knowledge of the pocket location is important for procedural planning and for durability of device placement and performance. Here, we report a patient who previously failed subcutaneous CIED placement due to incision manipulation with prior threatened device exposure requiring plane change to subpectoral pocket. Her course was complicated by submuscular migration of the CIED into her breast implant periprosthetic pocket. With subcutaneous plane change being inadvisable due to patient noncompliance, soft tissue support of subpectoral CIED placement with an acellular biologic matrix (ABM) was performed. Similar to soft tissue support used for breast implants, submuscular CIED neo-pocket creation with ABM was performed with durable CIED device positioning confirmed at 9 months postprocedure.

• Journal of The Korean Society of Agricultural Engineers
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• v.66 no.1
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• pp.39-48
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• 2024

Plastic greenhouses are simple structures consisting of lightweight materials such as steel pipes and polyvinyl chloride. However, serious damage occurs due to heavy winds and typhoon every year. To prevent a collapse of structural members, the Ministry of Agriculture and Rural Development has distributed plans and specifications for disaster-resistant standards. Despite these efforts, more than 50% of greenhouses still do not satisfy the disaster-resistant standards. Among the greenhouses that do not meet these standards, 85% are single-span greenhouses proposed 20 years ago. Consequently, there is a need to evaluate the safety of wind loads for the single-span greenhouse. Unfortunately, there are no design specifications for the greenhouses under wind loads. Therefore, a Korean design standard (KDS) has been utilized. KDS is defined with reference to wind speeds occurring once every 500 years, raising concerns about potential overdesign when considering the durability of plastic greenhouses. To address this, the modified wind load, considering the durability of the plastic greenhouse, was calculated, and a safety evaluation was conducted for sigle G-type plastic greenhouse. It was observed that the moment acting on the windward surface was substantial, and there was a risk of the foundation being pulled out if the basic wind speed exceeded 32 m/s. In terms of the combination strength ratio, it was less than 1.0 only on the leeward side when the basic wind speed was 24 m/s and 26 m/s. However, in all other cases, it exceeded 1.0, indicating an unsafe condition and highlighting the necessity for reinforcement.

• Journal of the Korea institute for structural maintenance and inspection
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• v.20 no.3
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• pp.140-148
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• 2016

This study examined the durability of face-slab concrete in Concrete-Faced Rock-filled Dams(CFRDs). The durability of face-slab concrete can be improved by optimizing the amount of fly ash in the cement mixture. Durability tests including plastic shrinkage, permeability, abrasion resistance, and repeated freezing and thawing were done on face-slab concrete specimens with different amounts of fly ash and blended PVA(Poly Vinyl Alcohol) fibre. When the effect of the fly ash content on concrete durability was evaluated, the results showed that a 15% fly ash content and 0.1% blended PVA fiber yielded the optimum durability level for concrete-faced rock-filled dams.

• Transactions of the Korean hydrogen and new energy society
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• v.23 no.5
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• pp.484-492
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• 2012

The TMS(Thermal Management System) heater in a fuel cell vehicle has been developed to prevent a decline of fuel cell durability and cold start durability. Main functions of the COD(Cathode Oxygen Depletion) heater are depletion of oxygen in a cathode as heat energy and consumption of electric power for rapid warming up of a fuel cell stack. This paper covers subjects including the design specification of a heater, heater controller for detection of overheat and reliability assessment including coolant pressure cycle test of a heater. To verify the design concept, burst pressure and deformation analysis of plastic housing were carried out. Also, temperature distribution analysis of heater surface and coolant inside of housing were carried out to verify the design concept. By designing the plastic housing instead of a steel housing, the 30% weight lightening and 50% cost reduction were attained. A module-based design of a TMS system including a heater or reducing the watt density of a heater is a problem to be solved in the near future work.

• Advances in materials Research
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• v.13 no.2
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• pp.115-128
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• 2024

Concrete is the most significant material in the construction industry which is required to construct several facilities like roads, buildings, and bridges etc. which leads to the economic development of a country. But now days, in view of sustainable development and environmental problems, plastic waste management is one of the major environmental issues due to its non-biodegradable nature which allows it to stay in the landfills until they are cleaned up. To overcome all these concerns, plastic waste may be used as a substitute of natural fine and coarse aggregate in concrete and a valuable solution to utilize the plastic items which causes several problems. In order to, present study is focused on the affecting properties of concrete as workability, compressive strength, and tensile strength of concrete with using plastic waste and without using plastic waste. Based on the detailed literature, it was observed that the plastic waste is not affecting the quality and consistency of concrete. However, as the number of PVC particles in the mixture increased, the drying shrinkage values decreased and the inclusion of plastic flakes can mitigate drying shrinkage cracking which leads the higher durability of concrete. Based on the comprehensive literature, it was also observed that the plastic aggregate found to be suitable for low and medium strength concrete. However, the investigation on the application of plastic aggregate in the high strength concrete is found limited. It was concluded that the optimum percentage of the plastic aggregate was found about 20%.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.2
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• pp.223-230
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• 2003

Stress patterns are created in the plastic spur gear tooth body by introducing a hole or a steel pin to improve stress distribution. Static analysis using finite element method is carried out to show the effect. The result shows that maximum stress as well as tooth tip displacement is dependent on the size and location of a hole or a steel pin. When a hole located on the tooth center line, the maximum static stress level and the tooth tip deflection is always higher than that of a solid gear. But, a considerable reduction in the maximum stress and tooth tip displacement is achieved by insertion of steel pin.