• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.405-406
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• 2006

Raw materials from different sources, produced by a given process and having equal chemical composition, are supposed to be equivalent. The differences in sintering behavior have been investigated on P/M steels obtained from four diffusion-bonded powders (Fe + Ni + Cu + Mo) on atomized iron base, at the same alloy contents. Two levels of carbon and two sintering conditions have been investigated. Dimensional changes, C content, hardness, microhardness pattern, universal hardness, fractal analysis, pore features, microstructure features, and rupture strength have been compared to characterize different raw materials. The results show that the claimed equivalence is not confirmed by experimental data.

• 수산해양교육연구
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• 제4권1호
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• pp.62-74
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• 1992

The effect of additional amounts of subsidiary materials on texture of fish meat paste were examined using Instron Universal Testing Machine to obtain fundamental data for steamed Alaska pollack meat paste showing good quality. The hardness revealed the good correlation with jelly strength among the six kinds of parameters of Instron texturometer. Products with higher hardness showed a better quality, but those with hardness higher than 16kg showed decreasing quality with increasing hardness. Predicting the quality of steamed Alaska pollack meat paste with various additional amounts of subsidiary materials as a function of hardness, H, the equation could be deduced as follows: H=11.56+0.54Xcs, H=12.22-0.23Xsp and H=11.65-7.13Xpp. The reasonable equations for predicting the quality of steamed Alaska pollack meat paste with various additional amounts of mixed subsidiary materials could be summarized as follows: H=11.57+0.53Xcs+0.44Xsp, H=11.97-1.83Xpp-0.17Xcs, and H=11.58+0.08Xpp-0.23Xsp.

• 대한치과의사협회지
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• 제20권12호통권163호
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• pp.1073-1081
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• 1982

The purpose of this study was to measure and compare the tensile strengths, elongation and Vicker's hardness values by heat treatments of three·commercial dental casting gold-silver-palladium alloys(Type A,B and G-50 alloys) used in Korea. Instron universal testing instrument and Vicker's hardness tester were used to determine their physical properties. The following results were obtained with the alloys tested. 1. It was determined that the tensile strengths generally tended to increase as the hardened condition (55.50 - 72.98 Kg/mm₂)than in softened condition (28.75 - 41.16 Kg/mm₂). 2. The results indicated that the elongation was the highest in the softened condition(12.30 - 27.0 %), and was the smallest in the hardened condition (3.6 - 5.8 %). 3. It was found that the Vicker's hardness number was the greatest in type G-50 hardened alloys (304.0), and the smallest in the type A softened alloys (130.0).

• 한국식품영양과학회지
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• 제27권4호
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• pp.659-663
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• 1998

Mook is a traditional Korean food made from the sediment of mungbean, cowpea, buckwheat or acorn. The air-dried sediment of cowpea(6~9%, dry basis) was heated to 80~95$^{\circ}C$ by continuous(method A) or instantaneous(method B) heating method and held at that temperature for 20min and then cooled at 15$^{\circ}C$ for 3hrs. The optimum deformation rate for the measurements of hardness and cohesiveness of cowpea mook by Instron Universal Testing Machine was 55~65% by method A and 60~70% by method B. The hardness of mook made by method A was the highest at heating temperature of 9$0^{\circ}C$, whereas that by method B was linearly decreased as the heating temperature increased at all concentrations. The mook made by method B had higher cohesiveness than that by method A. The ratio of cohesiveness to hardness was also higher in mook made by method B.

• 한국식품과학회지
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• 제20권3호
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• pp.310-316
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• 1988

식품과 유사하도록 수분, 전분, 단백질을 조합하여 모형식품을 만들고 가열온도와 가열시간을 변하시켜 가며 만든 gel의 texture를 universal testing machine으로 측정, 비교 분석하였다. 모형식품의 hardness, springiness, cohesiveness, gumminess 및 chewiness는 모두 고형분 함량과 높은 상관관계를 보였으며 $80^{\circ}C$, 20분 가열한 모형식품의 수분함량과 hardness에 대한 희 귀 식 은 $H(P_0S_4)=18.6405-3.8201M+0.1959M^2,\;H(P_1S_1)=244.7933-5.692M+0.0332M^2,\;H(P_4S_0)=693.0292-16.6884M+0.1005M^2$이였으며 이때의 상관계수는 각각 $0.996^{**},\;0.998^{**}$및 $0.998^{**}$이였다. 조직특성치와 가열온도 및 시간관의 상관관계는 모형 식품에 따라 달랐으며 단백질 식품에서는 유의성이 인정되지 않았고 특성치간의 상관관계는 비례적이나 전분질 식품의 hardness와 cohesiveness는 반비례적이였다. 저고형분 함량에서는 일정수준의 함량이 넘어서면서부터 증가하기 시작하여 순단백질 젤이 전분 제보다 높은 값을 나타냈다. $80^{\circ}C$, 20분간 가열한 모형식품의 harness와 단백질 함량과의 희귀식은 Hardness(고형분 20%)=5.6856-13.5670P+$9.7758P^2$이며 이때의 상관계수는 $0.95^{**}$였다.

• The Journal of Advanced Prosthodontics
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• 제5권2호
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• pp.110-117
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• 2013

PURPOSE. Polymethyl methacrylate (PMMA) is the most commonly used denture base material despite typically low in strength. The purpose of this study was to improve the physical properties of the PMMA based denture base resins (QC-20, Dentsply Ltd., Addlestone, UK; Stellon, AD International Ltd, Dentsply, Switzerland; Acron MC; GC Lab Technologies Inc., Alsip, Japan) by copolymerization mechanism. MATERIALS AND METHODS. Control group specimens were prepared according to the manufacturer recommendations. In the copolymer groups; resins were prepared with 5%, 10%, 15% and 20% acrylamide (AAm) (Merck, Hohenbrunn, Germany) content according to the moleculer weight ratio, respectively. Chemical structure was characterized by a Bruker Vertex-70 Fourier transform infrared spectroscopy (FTIR) (Bruker Optics Inc., Ettlingen, Germany). Hardness was determined using an universal hardness tester (Struers Duramin, Struers A/S, Ballerup, Denmark) equipped with a Vickers diamond penetrator. The glass transition temperature ($T_g$) of control and copolymers were evaluated by Perkin Elmer Diamond DSC (Perkin Elmer, Massachusetts,USA). Statistical analyses were carried out using the statistical package SPSS for Windows, version 15.0 (SPSS, Chicago, IL, USA). The results were tested regarding the normality of distribution with the Shapiro Wilk test. Data were analyzed using ANOVA with post-hoc Tukey test (P<.01). RESULTS. The copolymer synthesis was confirmed by FTIR spectroscopy. Glass transition temperature of the copolymer groups were higher than the control groups of the resins. The 10%, 15% and 20% copolymer groups of Stellon presented significantly higher than the control group in terms of hardness. 15% and 20% copolymer groups of Acron MC showed significantly higher hardness values when compared to the control group of the resin. Acrylamide addition did not affect the hardness of the QC-20 resin significantly. CONCLUSION. Within the limitation of this study, it can be concluded that copolymerization of PMMA with AAm increased the hardness value and glass transition temperature of PMMA denture base resins.

• 한국식품조리과학회지
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• 제1권1호
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• pp.57-64
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• 1985

This study was conducted to investigate the effect of fat on structure and texture of soybean curds by partial or whole replacement of soybean with defatted soy flour, The textural properties of soybean curd were examined by Instron universal testing machine, and the microscopic structure of soybean curds was examined by Scanning electron microscope(SEM). The results obtained were as follows ; 1. Textural parameters determined by Instron universal testing machine showed that hardness and gumminess of soybean curs were significantly increased as the fat contents of the samples decreased. On the while, springiness of the samples were significantly lowered as the fat content decreased. 2. Microscopic structure of soybean curds examined by SME demonstrated that samples with high fat had more fat globules and thinner network layer which were assumed to surround moisture with.

• 대한치과보철학회지
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• 제41권4호
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• pp.493-502
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• 2003

Statement of problem : Removable partial denture and complete denture often require denture base relines to improve the fittness against tissue-bearing mucosa because of the gradual change in edentulous ridge contour and resorption of underlyng bony structure. Self-curing hard reline resins offers the immediate and relatively inexpensive means to be recondition the surface of denture base directly However weak bond between denture base resin and reline material can harbor bacteria, promote staining, or result in complete separation of the two materials. Purpose : The purpose of this study was to evaluate the effect of denture cleansers on bond strength and surface hardness of reline resin to denture base resin Denture base resin beams($60.0{\times}15.0{\times}3.0mm$) were made with Lucitone 199. Material and methods : 10mm section was removed from the center of each specimen. The samples were replaced in the molds and the space of l0mm sections were packed with Tokuso Rebase reline material. The specimens were immersed in denture cleansers (Polident, Cleadent) and were evaluated after 1 week, 2 weeks, and 4 weeks. The bond strength and surface hardness of self-curing hard reline materials to heat-curing denture base resin were measured using an UTM (universal testing machine). Results and conclusion : 1) There was no significant difference of usage, kind, and denture cleaner by application time on the bonding strength of self-curing hard reline resin to denture base resin. 2) There was no significant difference of usage, kind, and denture cleaner by application time on the surface hardness, but the surface hardness showed decreasing tendency, as the time of immersion was extended. 3) The failure modes of the specimens was initially adhesive failure and finally cohesive failure of self-curing hard reline resin.

• 한국식품조리과학회지
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• 제10권4호
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• pp.351-356
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• 1994

Comparisions were made for cooking times, internal temperatures, thiamin contents and textural properties of various portion weights of egg mixture cooked in a microwave oven at high and/or low power levels and in a conventional double boiler. The mean internal temperatures of conventionally cooked egg mixtures were 76.4~80.7$^{\circ}C$. When cooking was made by steaming, the mean internal temperature were comparable among samples. With the microwave cooking, the range of mean temperature was 83.8~96.4$^{\circ}C$, and they were significantly higher than the conventionally cooked egg mixtures. The hardness determination was conducted using universal testing machine and a taste panel. Samples cooked with steam or with larger portion weight had softer texture than samples cooked by microwaves or smaller amount, respectively. Mean internal temperature was significantly(r=0.99, p<0.05) correlated with mechanical hardness determination. Statistical analyses indicated no significant difference in the thiamin content among various treatments.

• 대한가정학회지
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• 제23권3호
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• pp.63-73
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• 1985

This study was conducted to investigate the effects of fermentation time and the proportion of wheat flour to rice flour on Jeung-Pyun's texture. Textural characteristics were examined through sensory Evaluation and Instron Universal testing machine. The properties examined through sensory evaluation were grain, softness, sourness, chewiness and overall quality. Wigh Instron, hardness, cohesivenessm elasticity, gumminess and chewiness were measured. RESULTS : 1. Sensory evaluation data indicated that Jeung-Pyun containing 25% wheat flour and fermented 2 hrs were obtained higher scores than any other Jeug-Pyuns in the grain, softness and overall quality. 2. pHs of Jeung-pyundough and Jeung-Pyun containing 100% rice flour were lower than pHs of those with wheat flour added. 3. Volume of Jeung-Pyun increased as the proportion of wheat flour to rice flour and the length of fermentation time increased. 4. Instron measurement indicated that the hardness of Jeung-Pyun with 50% wheat flour added and 2hrs fermentation time was higher than of others.