• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.7
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• pp.4388-4397
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• 2015

The purpose of this study was to research the property change of acrylic resins depending on the induced-beam change and research the improved physical property of dry-heat and microwave-cured dental place acrylic resin in order to develop the acrylic resins with the optimum characteristic. As a result of observing flexural rigidity, hardness and color difference, the dry-heat-cured specimens of Vertex RS and Paladent 20 showed ideal property at 5, 15, and 25 kGy irradiation. The microwave-cured specimens of Vertex RS and Paladent 20 showed ideal property at 5 kGy irradiation. The correlation analysis showed a positive correlation among ARD, flexural rigidity (0 418), E coefficient (0.675) and Barcol hardness (0 588). The radiation cure technology is helpful for relieving the contamination caused by the manufacture of polymer composite. It can significantly contribute to the fusion of ultra violet cure technology and nano technology and the improvement of mechanical property without giving effect to the workability of polymer.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.11a
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• pp.255-257
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• 2012

Epoxy resin without any hardener can harden in the presence of hydroxide ions in cement mortars and concretes at ambient temperature. The purpose of present study is to examine the hardening properties of hardener-free epoxy-modified mortars by curing conditions. The hardener-free epoxy-modified mortars using diglycidyl ether of A epoxy resin are prepared with various polymer-cement ratios, and subjected to initial moist/dry curing, initial steam(90℃) curing, initial steam/heat(80℃, 100℃) curing.As a result, degree of hardening of epoxy resin in initial moist/dry cured, initial steam cured and initial steam/heat(80℃) cured hardener-free epoxy-modified mortars is decreased with increasing polymer-cement ratio. However, it is markedly improved with additional dry-curing periods. On the other hand, regardless of the polymer-cement ratio and dry curing periods, degree of hardening of hardener-free epoxy-modified mortars with initial steam/heat(100℃) cure is over 95%.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2009.11a
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• pp.55-59
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• 2009

The epoxy resin without hardener can harden by a ring-opening reaction in the presence of the alkalies produced by the hydration of cement in epoxy-modified mortars and concretes. This paper investigates the effect of curing conditions on the strength improvement of polymer-modified mortars using bisphenol A-type epoxy resin without hardener. The polymer-modified mortars using epoxy resin are prepared with various polymer-cement ratios, and subjected to ideal, water, dry and heat cures. In the heat cure, the epoxy-modified mortars are sealed or unsealed with a PVDC (polyvinylidene chloride) film. The epoxy-modified mortars are tested for flexural and compressive strengths at desired curing methods. The microstructures of the epoxy-modified mortars are also observed by scanning electron microscope. The effects of curing conditions on the strength development of the epoxy-modified mortars are examined. From the test results, the marked effectiveness of the heat cure under the PVDC film sealing against the development of the strength of the epoxy-modified mortar without the hardener is recognized. The flexural and compressive strengths of 7-day-90℃ heat-cured, PVDC film-sealed epoxy-modified mortars without hardener reach 7 to 17MPa and 24 to 44MPa respectively, and are two to three times of Unmodified mortar. Such high strength development of the epoxy-modified mortars may be achieved by the dense microstructure formation by cement hydrates and the hardening of the epoxy resin in the mortars.

• The Journal of Advanced Prosthodontics
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• v.7 no.1
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• pp.47-50
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• 2015

PURPOSE. This study aimed to discover a way to increase the bond strength between bis-acryl resins, using a comparison of the shear bond strengths attained from bis-acryl resins treated with light curing, pressure, oxygen inhibition, and heat. MATERIALS AND METHODS. Self-cured bis-acryl resin was used as both a base material and as a repair material. Seventy specimens were distributed into seven groups according to treatment methods: pressure - stored in a pressure cooker at 0.2 Mpa; oxygen inhibition- applied an oxygen inhibitor around the repaired material,; heat treatment - performed heat treatment in a dry oven at $60^{\circ}C$, $100^{\circ}C$, or $140^{\circ}C$. The shear bond strength was measured with a universal testing machine, and the shear bond strength (MPa) was calculated from the peak load of failure. A comparison of the bond strength between the repaired specimens was conducted using one-way ANOVA and Tukey multiple comparison tests (${\alpha}$=.05). RESULTS. There were no statistically significant differences in the shear bond strength between the control group and the light curing, pressure, and oxygen inhibition groups. However, the heat treatment groups showed statistically higher bond strengths than the groups treated without heat, and the groups treated at a higher temperature resulted in higher bond strengths. Statistically significant differences were seen between groups after different degrees of heat treatment, except in groups heated at $100^{\circ}C$ and $140^{\circ}C$. CONCLUSION. Strong bonding can be achieved between a bis-acryl base and bis-acryl repair material after heat treatment.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.9 no.1
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• pp.19-24
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• 1976

To examine the storage effect of the dry cured cultured undaria pinnetifida, its components were researched according to different places and periods of production and in heat treatment of it, how the different time, temperature and salt concentration can effect on its storage was researched as follows. In Pohang and Yeosu districts the most suitable period of processing was around the end of December and in Wando district, around the end of January. When it was heat-treated separately at $90^{\circ}C\;and\;100^{\circ}C$ there of occurred the comparative low increase of organic acids and volatile acids, and the slight decrease of pigment. When it was heat-treated in sea water and satuarated NaCl solution, the obvious change was not found in all components, and in fresh water organic acids and volatile acids were conspicuously increased. When it was heat-treated according to the different heating time (long or short), there was no remarkable change in all components, but when heat-treated for 20 sec. the decrease of carotenoid was conspicuous. When heat-treated for 40 sec. separately at $90^{\circ}C\;and\;100^{\circ}C$ in sea water, better effect for storage was resulted.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.4
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• pp.982-989
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• 2004

The following is the conclusion drawn from a review on the clinical cases cured by Jaeumkangwha-tang in perspective of Hyungsang medicine. Jaeumkangwha-tang originated from the modified Jibaiksamul-tang in 'Manbyunghuichun(萬病回春)' and applied to the diseases induced by flaming fire due to deficiency of Yin. In 'Donguibogam', there are two kinds of Jaeumkangwha-tang. One in the chapter of kidney is mainly prescribed to replenish the Jung of kidney and applicable to the cases with configuration and symptom of kidney along with fire. The other one in the chapter of fire is applied to the symptoms of flaming fire due to deficiency of Yin. The characteristics of the patients treated by Jaeumkangwha-tang from the viewpoint of Hyungsang medicine can be classified as follows : ① configuration: Dam type, Shin type, inverted triangular type(:天垂象), bird type, round eyes, thin lips, slender waist, thin leg, pretty face, sparkling eyes, prominent upper lip and upward eyes and nose. ② color : dark red complexion, red cheek bone, red lips and red glabella. ③ pulse : fine and fast pulse and pulsation on the Chuk(尺) in man and so forth. ④ symptoms: agility, talkativeness, pimpled face, crooked back, weakness to the heat of summer, light eating, timidity, blood-shot eyes, night sweat, cough, abundant phlegm, hemoptysis, bloody spittle, enervation, emaciation, back pain, flaccidity of lower limbs, involuntary emission, nocturnal emission, heat sensation in the chest palms and soles, anger, flush on cheek bone, red lips and dry mouth, reddish tongue, stiff excrement, scanty yellow urine, etc.

• Journal of the Korea Concrete Institute
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• v.25 no.4
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• pp.457-465
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• 2013

This study discussed the influence of mixtures and curing conditions on the development of strength and microstructure of RPC using ternary pozzolanic materials. Through pilot experiment, various RPC was manufactured by adding single or mixed ternary pozzolanic materials such as silica fume, blast furnace slag and fly ash by mass of cement, up to 0~65%, and cured by using 4 types of method which are water and air-dried curing at $20^{\circ}C$, steam and hot-water curing at $90^{\circ}C$. The results show that the use of ternary pozzolanic materials and a suitable curing method are an effective method for improving development of strength and microstructure of RPC. The unit volume of cement was greatly reduced in RPC with ternary pozzolanic materials and unlike hydration reaction in cement, the pozzolanic reaction noticeably contributes to a reduction in hydration heat and dry shrinkage. A considerable improvement was found in the flexural strength of RPC using ternary pozzolanic materials, and then the utilization of a structural member subjected to bending was expected. The X-ray diffractometer (XRD) analysis and Scanning Electronic Microscope (SEM) revealed that the microstructure of RPC was denser by using the ternary pozzolanic materials than the original RPC containing silica fume only.