• Transactions of Materials Processing
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• v.27 no.6
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• pp.370-378
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• 2018

Cold forging, carried out at room temperature, leads to high dimensional accuracy and excellent surface integrity as compared to other forging methods such as warm and hot forgings. In the cold forging process, WC-Co (Tungsten Carbide-Cobalt) alloy is the mainly used material as a core dies because of its superior hardness and strength as compared to other structural materials. For cold forging, die life is the most significant factor because it is directly related to the manufacturing cost due to periodic die replacement in mass production. To investigate die life of WC-Co alloy for cold forging, mechanical properties such as strength and fatigue are essentially necessary. Generally, uniaxial tensile test and fatigue test are the most efficient and simplest testing method. However, uniaxial tension is not efficiently application to WC-Co alloy because of its sensitivity to alignment of the specimen due to its brittleness and difficulty in thread machining. In this study, shape of specimen, tools, and testing methods, which are appropriate for uniaxial tensile test for WC-Co alloy, are proposed. The test results such as Young's modulus, tensile strength and stress-strain curves are compared to those in previous literature to validate the proposed testing methods. Based on the validation of test results it was concluded that the newly developed testing method is applicable to other cemented carbides like Titanium carbides with high strength and brittleness, and also can be utilized to carry out fatigue tests for further investigation on die life of cold forging.

• Korean journal of food and cookery science
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• v.18 no.4
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• pp.399-406
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• 2002

Steam cakes were prepared with the addition of pine needle powder(Pinus densiflora Seib. et Zucc) at 0%, 1%, 2%, 3%, 4%, and their sensory quality and mechanical characteristics were compared. Sensory evaluation was performed and compared between the subjects in twenties and forties of age. As a result of the sensory evaluation in forties, steam cake with 3% pine needle powder showed the highest score in overall acceptability; however, in the group of twenties, control cake with no pine needle powder showed the highest score. In the measurement of color changes, L value(lightness) was decreased, but a value(redness) and b value(yellowness) were increased as the addition of pine needle powder increased. In textural characteristics, the hardness, springiness, gumminess and brittleness of steam cake were decreased by the increase of pine needle powder. The hardness and brittleness were increased as the storage time increased.

• Journal of the Korean Applied Science and Technology
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• v.37 no.2
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• pp.183-191
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• 2020

This study monitored the rheological properties of jams manufactured using the black ginseng and black garlic. The conditions for mixing black jam were black ginseng (X₁, 30-54 g), black garlic (X₂, 75-135 g), pectin 4.5 g, apple paste 270 g, and fructo-oligosaccharide 360 g. The response surface analysis was performed with springiness, cohesiveness, chewiness, brittleness and gumminess. The R²s of the regression equation for springiness, cohesiveness, chewiness, brittleness and gumminess were recognized at a significant level of 5 to 10 %, with 0.8948, 0.9103, 0.9032, 0.9097, and 0.8561, respectively. The combination conditions of black ginseng and black garlic with the highest springiness of black jam were found to be 194.39% (springiness) with black ginseng 54.00 g and black garlic 105.83 g, while the conditions of black ginseng and black garlic mixing with the lowest springiness were found to be 164.11% with black ginseng 31.48 g and black garlic 119.43 g. The mixing conditions of black ginseng and black garlic with the highest cohesiveness of black jam and its consistency were 40.96% (cohesiveness) with black ginseng 48.85 g and black garlic 129.62 g, while black ginseng and black garlic combination conditions with the lowest cohesiveness were found to be 32.96% with black ginseng 50.06 g and black garlic 82.77 g. Black ginseng and black garlic mixing conditions, which have the highest chewiness of black jam, was 43.19 g (chewiness) from black ginseng 42.95 g and black garlic 106.83 g. Black ginseng and black garlic mixing conditions and their brittleness were found to be the highest in black ginseng 32.10 g and black garlic 88.04 g to 16,874 g. Black ginseng and black garlic mixing conditions and their brittleness were found to be 678 g from black ginseng 50.53 g and black garlic 83.91 g. Black ginseng and black garlic mixing conditions and their gumminess were 14.06 g with black ginseng content of 32.91 g and black garlic content of 124.60 g. By examining the relationship between black ginseng/black garlic ratio and the rheological property of black jam from above results, it is believed that black jam can be produced for anyone to enjoy using health function material.

• Journal of the Korean Society of Food Culture
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• v.30 no.2
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• pp.213-219
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• 2015

This study was conducted to promote the utilization of fish paste containing four different amounts (0%: control, 2, 4, and 6%) of cheonggukjang powder. For Hunter color values, L values of samples decreased as concentration of cheonggukjang powder increased, and a and b values increased. Folding tests for all samples showed good flexibility. In the texture meter test, hardness, cohesiveness, and springiness increased according to increasing concentrations of cheonggukjang powder. However, gumminess and brittleness of fish paste were reduced upon addition of cheonggukjang powder. In the sensory evaluation, fish paste prepared with 2% cheonggukjang powder was more preferred over other fish pastes. This study suggests that addition of 2% cheonggukjang powder to fish paste could be a good way to increase cheonggukjang powder without decreasing texture acceptability.

• Journal of the Korea Safety Management & Science
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• v.6 no.1
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• pp.311-323
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• 2004

This paper is to study the energy absorption characteristics of CF/Epoxy(Carbon Fiber/Epoxy Resin) laminated shell with the various curvatures subjected to transverse impact loadings under the low impact velocity in consideration of design of structural members for use of transportation machine, which are consisted of the characteristics of high stiffness, strength and lightweight. The curvature radius are associated with the energy absorption characteristics of CF/Epoxy laminated shell which is brittleness material. In all tests, maximum load of CF/Epoxy laminated plate is higher than that of laminated shell with curvature, but maximum deflection is lower. And then absorbed energy of laminated shell with curvature is higher than laminated plate(curvature radius is unlimited), As curvature radius is increased, the absorbed energy is increased in laminated shell with curvature.

• Korean journal of food and cookery science
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• v.17 no.6
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• pp.611-616
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• 2001

This study was carried out to investigate the effect of various lipids on the quality of Yackwa. Sesame oil, soybean oil, margarine for cream, margarine for pie and shortening were used as lipid for making dough of Yackwa in this study. The expansion rate of Yackwa ranked in the order of shortening, margarine for pie, soybean oil, margarine for cream and sesame oil. The Yackwa made with shortening showed low hardness, cohesiveness, gumminess and brittleness such as the ones made with sesame oil. The Yackwa made with sesame oil was oily and showed the lowest acceptability, but the Yackwa of shortening gained the highest score of acceptability in sensory evaluation. In conclusion. this experimental result indicated that shortening would be very useful as a substitute for sesame oil in making Yackwa.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2101-2106
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• 2011

It is reported that about more than 45% of damage shown in railroad rails include breakage of rail end which cross the center of Thermit welded zone. Thermite welding is always accompanied by numerous aluminum oxide and secondary inclusions, which may have a negative influence on the ductility and toughness of the weld metal. In this study the aluminum powder recycled by waste aluminum can was used for iron oxide generated after the process of welding rod and the remain aluminum was reduced by minimizing the quantity of aluminum. And complete dissolution was induced by using ferro Mn powder as the additive element. This study reviewed the applicability of heat treatment in the welded zone of rail using ceramic heating pad by carrying it out. This study could observe the improvement of the mechanical characteristics (UTS and elongation) and the changes of failure mechanism from brittleness to ductility. It could be found that improved strength and elongation result from pearilte fine structure.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.5 no.1
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• pp.33-38
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• 2006

Silicon has been widely used in electronic parts as a semiconductor equipment. It, however, requires much effort to grind without microcrack and chipping because of its high hardness and brittleness. So far, many studies for the grinding of engineering ceramics have been done, but not for the grinding of silicon. In this paper, a theoretical analysis on the grinding forces is introduced. Grinding experiments were performed at various grinding conditions including grinding directions (Up grinding and Down grinding), table speeds and depth of cuts. The grinding forces were measured to compare at various grinding conditions. The experimental values agree well with theoretical ones.

• Korean journal of food and cookery science
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• v.27 no.6
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• pp.723-733
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• 2011

This study was performed to examine the optimum addition amount of Hizikia fusiformis powder to be used with rice flour in the preparation of Hizikia fusiformis Sulgidduk (traditional rice cake). Hizikia fusiformis powder was added to rice powder at ratios of 5, 10, 15 and 20% (w/w). The moisture content of Sulgidduk was increased with the addition of Hizikia fusiformis powder, whereas the pH content was decreased. The addition also lowered the lightness and yellowness values but increased the greenness value. Mineral contents were increased. Hardness, springiness, and brittleness were decreased, and cohesiveness was increased as the added powder content also increased. In the sensory evaluation of Hizikia fusiformis Sulgidduk, color, flavor, taste, softness, chewiness, moistness, cohesiveness, and overall acceptability characteristics were all highest at the 10% addition level. Thus it can be proposed that this is the ideal level of Hizikia fusiformis addition in terms of the sensory properties of the cooked product.

• Computers and Concrete
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• v.2 no.3
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• pp.215-238
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• 2005

This work is based on a nonlinear finite-element model with proven capacity for yielding realistic predictions of the response of reinforced-concrete structures under static monotonically-increasing loading. In it, the material description relies essentially on the two key properties of triaxiality and brittleness and, thus, is simpler than those of most other material models in use. In this article, the finite-element program is successfully used in investigating the behaviour of a series of RC walls under static cyclic loading. This type of loading offers a more strenuous test of the validity of the proposed program since cracks continuously form and close during each load cycle. Such a test is considered to be essential before attempting to use the program for the analysis of concrete structures under seismic excitation in order to ensure that the solution procedure adopted is numerically stable and can accurately predict the behaviour of RC structures under such earthquake-loading conditions. This is achieved through a comparative study between the numerical predictions obtained presently from the program and available experimental data.