• Transactions of Materials Processing
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• v.18 no.2
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• pp.160-165
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• 2009

A Study on Effects of the Runner and the Gate of double shot injection molded Parts using CAE Double shot injection molding can inject two different materials or two different colors in the same mold in a injection molding process. Double shot injection molded parts can be characterized that the base part maintains strength and specified part can inject soft-material. It can reduce the production cost by single automatic operations. In this paper, we designed double shot injection mold for automobile emote control To inject secondary part, this part is used as an insert after external appearance of product is injected. CAE analysis was progressed gate location and runner size as variables. The analysis result is reflected in mold design process. As a result, it could solve problems which are generated in the conventional mold. Additionally, cost can be downed by reducing runner weight. As well as it could omit painting process because the surface of finished product is improved through new mold.

• Journal of Environmental Science International
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• v.18 no.5
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• pp.517-525
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• 2009

We measured ambient concentrations of hazardous air pollutants such as volatile organic compounds (VOCs) and aldehydes in residential areas nearby small and medium scale shipbuilding companies. The VOC concentrations were higher during the normal operation periods than vacation at which almost all operations were shutdown. Concentrations of VOCs was higher, as the sampling site was nearer from shipbuilding companies. The major components of VOCs were m,p-xylene, ethylbenzene, o-xylene, toluene, and 1,3,5-trimethylbenzene which had been found as major VOC compounds emitted from painting processes of shipbuilding in the previous studies. The major components of aldehydes analyzed were benzaldehyde, acrolein, formaldehyde, and acetaldehyde. The concentration of aldehydes was highest at the furthest sampling point from shipbuilding companies because the formation of aldehyde compounds could be occurred by the secondary chemical reactions of VOCs. The results of this study shows a proper counterplan need to be established for the reduction of hazardous air pollutants emitted from small and medium scale shipping companies.

• Journal of Technologic Dentistry
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• v.9 no.1
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• pp.51-55
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• 1987

One of the primary advantages of acrylic resin teeth is their ability to bond chemically to the denture base resins. Fracture od acrylic resin teeth from a maxillary denture, however, is not uncommon. Bonding failures have been attributed to faulty boil-out procedures that fail to eliminate all traces of wax from the ridge lap surfaces of the teeth and to contamination of the ridge lap surface by careless application of tinfoil substitute. Attempts to increase the strength of the bond between acrylic resin teeth and heat-cured denture base resin include grinding the glossy ridge lap surface (in fluid system), painting the ridgelap surface of the teeth with monomer-polymer solution, and cutting retention grooves in the ridge lap surface of the teeth. This latter method has been tested by applying a tensile force in a labial direction to the incisal part of the lingual surface of the acrylic resin teeth. A progressive shear compressive load was applied at an angle to the lingual surface of acrylic resin teeth bonded to denture base acrylic resin. No statistically singificant advantage was derived by preparing retention grooves of different shapes in the ridgelap surface of the denture teeth.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.244-249
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• 2004

In this paper, shielding effectiveness(SE) of the shielding paint of electromagnetic(EM) waves was investigated with actual experiments. The shielding paint used in this study were made of powder of conductive materials - Ag, Cu, Al, Sn, Ni. Cr, Graphite and Charcoal etc. with a solubility in oil and water. Also, the paper was used as a base sheet. The experiment was carried out by using a shielding evaluator(Shielding box) TR17302 with an ADVANTEST spectrum analyzer, model R3361C. It was found from the experimental results that silver, copper, nickel were good candidates as a shielding material against the EM waves with increasing the SE as the composite was laminated. The characteristics of the SE against the EM waves depended on a mode of preparation of specimen. The effects of density of particles on the SE were studied about the EM shielding paint. The SE strongly depended on the electric resistance by density of painting particles. SE increased as the density of particles was increasing.

• Journal of the Korea Furniture Society
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• v.20 no.4
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• pp.317-325
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• 2009

On the ground of that toy as for infants is an important tool for education as well as play and furthermore it has a great influences on their growth and development, the present study intends to analyze the characteristics of the infant-oriented toys made of wood, the environment-friendly material. Object of the study includes the infants aged 2 to 7, and the wooden toy not only in domestic also international cases are investigated and analyzed from the point of function and design in particular, and the infant-oriented wooden toy is finally characterized. The wooden toys are classified in 5 items according to functions. There are toy helping a physical development like small muscles, toy improving the creativity, toy assisting language learning like Korean & English, toy contributing to number understanding and counting, and toy for imitation of social roles. The characteristics of the wooden toy are that the natural color & grain of wood are shown first, and also the natural texture & aroma of wood are felt secondly, and geometric design and shape are often presented thirdly, and recycling is available fourthly, and it is expensive finally. In order to revitalize the wooden toys lagging behind the cheap and diverse toys made of plastic, it is highly needed that development of the environment-friendly painting, unique design, marketing strategy of enterprises and use of domestic wood material.

• Design & Manufacturing
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• v.2 no.6
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• pp.49-55
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• 2008

Double-injection molding can inject two different materials or two colors in the same mold and process. If this injection process use, product has ability because the base part maintain strength and specified part can inject soft-material. It makes the cost down by single operation automatically for saving wages. In this paper, we designed double-injection mold for automobile remote control to inject secondary using this part as insert after inject external appearance of product. CAE analysis was progressed gate location and runner size as variable and analysis result is reflected in mold design process. As a result, it could solved badness that is generated at the conventional mold. Additionally, cost is downed by reducing loss of runner as well as could omit painting process because surface of finished product is improved through new mold.

• Journal of Gifted/Talented Education
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• v.3_4 no.1
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• pp.148-157
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• 1994

"Is a given boy or girl gifted in physics\ulcorner" That is a very complicated question and it is not easy to answer it as creativity and talents have many aspects. The lecture is devoted to analysis of several of them. In particular, we shall discuss the following points: 1) "Poets in physics". Some pupils have a seldom ability to create very beautiful, intellectual constructions starting from very few assumptions. Any building consists of commonly used bricks or other building elements, any book contains only several tens of commonly used letters or other graphic elements, also any painting may be created by appropriate use of several colors. Some buildings are nice, some not. Some paintings are beautiful, some not. Certain pupils, by appropriate use of several simple laws, are able to create beautiful constructions. They are like poets writing poetry by using several tens of letters known to everybody. 2) "Free hunters". Some pupils solve even very typical problems in a very untypical ways. Their independence in thinking is especially valuable. 3) "Small discoverers". Even very rich syllabuses do not contain whole physics. Some pupils e.g. during solving problems discover laws or rules that are absent in the syllabus. For example, some of them are able to make use of symmetry or dimensional analysis without any preliminary knowledge of that matter. The considerations are illustrated with different examples taken from physics or mathematics. The subject is very large and, of course, we are not able to present the problem in a complete way.o present the problem in a complete way.

• Journal of environmental and Sanitary engineering
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• v.17 no.2
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• pp.26-33
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• 2002

Ultimate objective of industrial hygiene is the prevention of health impairment that may result from exposure to chemicals at workplace. Workers in solvent thinner-using occupation environment may be highly exposed to VOCs (volatile organic compounds) because solvent thinner has been used extensively such as painting, spraying, degreasing, coating and so on in Korea. The purpose of this study was to recognize, evaluate, and propose the control methods of VOCs from solvent thinner-using workplace. Five target volatile organic compounds (benzene, toluene, ethylbenzene, o-xylene, and m-xylene) were monitored in H company of Shiwa Industrial Complex and analyzed in perosnal, occupational indoor and outdoor during working hours simultaneously. Engineering control such as local ventilation should be made in considering the long-term exposure, though measured VOCs concentration did not exceed the workplace exposure standards. In addition, air cleaning device should be installed in local ventilation because Shiwa Industrial Complex has had the serious ambient air pollution. Currently, environmental purification using $TiO_2$ photocatalyst have attracted a great deal of attention with increasing number of recent environmental problems. In this study, $TiO_2$ sol coated on the ceramic bead was prepared by sol-gel method and the photodegradation of target compounds was investigated in gas phase by the exposure to UV-A lamp(365nm) in a batch system.

• Journal of Energy Engineering
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• v.13 no.2
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• pp.112-117
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• 2004

Volatile organic compounds (VOCs) are low calorific value gases (LCVG) emitted from chemical processes such as painting booth, dye works and drying processes etc. Characteristics of VOCs are low calorific values less than 150kcal/㎥, high activation energy for ignition and low energy output. These characteristics usually make combustion unstable and its treatment processes needs high-energy consumption. The cyclone combustion system is suitable for LCVG burning because it can recirculate energy through a high swirling flow to supply the activation energy for ignition, increases energy density In make a combustion temperature higher than usual swirl combustor and also increases mixing intensity. This research was conducted to develop optimized cyclone combustion system for thermal oxidation of VOCs. This research was executed to establish the effect of swirl number with respect to the combustion temperature and composition of exhausted gas in the specific combustor design.

• BMB Reports
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• v.43 no.10
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• pp.664-669
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• 2010

The present study aimed to investigate the membrane stabilizing effect of Thymoquinone (TQ) on cell surface glycoconjugates and cytokeratin expression against DMBA induced hamster buccal pouch carcinogenesis. 0.5% DMBA painting (three times per week) in hamster buccal pouches for 14 weeks resulted in the formation of well developed oral squamous cell carcinoma. We observed 100% tumor formation with marked abnormalities of glycoconjugates status in tumor bearing hamsters as compared to control animals. Oral administration of TQ at a dose of 30 mg/kg body weight, to DMBA painted hamsters on alternate days for 14 weeks, reduced the tumor formation as well as protected the levels of cell surface glycoconjugates in DMBA painted hamsters. The present study thus suggests that TQ has potent chemopreventive efficacy as well as protected the abnormalities on cell surface glycoconjugates during DMBA induced hamster buccal pouch carcinogenesis.