• Proceedings of the Korean Society of Precision Engineering Conference
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.1483-1486
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• 2004

Purpose of this paper is to accummulate database of automotive steel sheet from mild steel to high strength steel in cold rolled steel sheets. Physical properties, mainly mechanical properties, of steel sheet are tested and all data are arranged to one sheet. Methods of test are composed of FLD, tensile strength test, chemical composition, surface roughness and product conditions. Finally this database will be helpful to automotive body designers and die designers to design automotive body parts and tools in a material point of view.

• Fibers and Polymers
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• 제2권3호
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• pp.141-147
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• 2001

The effect of compositions of isophorone diisocyanate (IPDl)/4.4'-diphenylmethane diisocyalate (MDI) and polypropylene oxide diol (PPG, $M_w$: 3000)/1,4-butane diol (BD) on the properties of UV-cured polyurethane acrylate films based on 2-hydroxyethyl acrylate (HEA) was examined. UV-curable polyurethane acrylates were formulated from the prepolymer. trimethylol propane triacrylate (TMPTA) as a reactive diluent, and 1-hydroxycyclohexyl ketone (Irgacure 184) as a photoinitiator. Dynamic mechanical thermal properties and elastic properties of UV-cured polyurethane acrylates was fecund to depend on the chemical composition of IPDl/MDl and PPG/BD. As the BD content increased, the tensile storage modulus of all series samples increased significantly. The storage modulus increased in the order of samples A (IPDI based samples)> samples B (IPDI/MDl (7/3 molar ratio) based samples) > samples C (IPDI/MDl (5/5 molar ratio) based samples at the same composition. Two distinct louts modulus peaks for all samples are observed owing to the softs segment glass transition temperature ($T_gh$) and hard segment glass transition temperature ($T_gh$). The difference between $T_gh$, and $T_gh$, (Δ$T_g$) increases in the order of A > B > C at the same composition. In cycle test, the initial onset strain (%) was found to decrease with increasing BD content in PPG/BD and with increasing MDI content in IPDI/MDl.

• Journal of the Korea Institute of Military Science and Technology
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• 제14권1호
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• pp.15-21
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• 2011

In this paper, the results of experimental analysis for the chemical composition and strengh verification of Bailey Panel Bridge have been presented. Some of main sections of bailey bridge colllected from military engineer troops were prepared for the chemical composition and strengh verification. The composition test and strength verification were conducted by using the optical microscope and Scanning Electron Microscope(SEM), Automatic Control Spark Emission Spectrometer(OBLF), X-ray Fluorescence Spectroscopy(XRF) and Instron measurement. The results showed that currently used sections of bailey bridge passed the strength verification and could be operated in drill of troops and battle fields.

• Journal of the Korea Institute of Military Science and Technology
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• 제17권3호
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• pp.289-295
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• 2014

The composition of bright flash device is a pyrotechnic mixture consisting of metal powder, oxidizer and additives. A pyrotechnic mixture of bright flash device generates a bright flash through burning after being ignited by initiator. The function of bright flash is to distract or incapacitate electro optical sensor systems and enemy eyes temporally. This study is to develop composition of pyrotechnic mixture of bright flash and to analyze the test results by considering intensity and efficiency of light.

• Journal of the Korean institute of surface engineering
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• 제43권2호
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• pp.64-72
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• 2010

CuSnZn electroplating was investigated as alternative to Ni plating. Evaluation of electrolyte and plating process was performed to control physical characteristics of the film, and to collect practical data for application. Hull-cell test was conducted for basic comparison of two commercialized products and developed product. Based on hull-cell test results, long term test of three electrolytes was performed. Various analysis on long term tested electrolyte and samples have been done. Reliable and practical data was collected using FE-SEM (FEI, Sirion), EDX (ThermoNoran SIX-200E), ICP Spectrometer (GBC Scientifi c, Integra XL), FIB (FEI, Nova600) for anlysis. Physical analysis and reliability test of the long term tested film were also carried out. Through this investigation plating time, plating speed, electrolyte composition, electrolyte metal consumption, hardness and corrosion resistance has been compared. This set of data is used to predict and control the chemical composition of the film and modify the physical characteristics of the CuSnZn alloy.

• Animal Bioscience
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• 제36권10호
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• pp.1568-1577
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• 2023

Objective: A study was conducted to determine the chemical composition of banana meal and rice bran from Australia or South-East Asia and test the hypothesis that there are no differences in rice bran produced in different countries, but there are differences between full-fat and defatted rice bran. Methods: Two sources of banana meal and 22 sources of rice bran (full-fat or defatted) from Australia or South-East Asia were used. All samples were analyzed for dry matter, gross energy, nitrogen, amino acids (AA), acid hydrolyzed ether extract (AEE), ash, minerals, total starch, insoluble dietary fiber, and soluble dietary fiber. Banana meal was also analyzed for sugars including glucose, fructose, maltose, sucrose, stachyose, and raffinose. Results: Chemical analysis demonstrated that banana meal from the Philippines is primarily composed of starch. Full-fat rice bran from Australia had greater (p<0.05) concentrations of AEE, lysine, and glycine than samples from the Philippines and Vietnam. Full-fat rice bran from Australia and Thailand had greater (p<0.05) concentrations of gross energy and most AA than rice bran from Vietnam. Full-fat rice bran from Australia had greater (p<0.05) concentrations of tryptophan and manganese than all other sources, but full-fat rice bran from the Philippines contained less (p<0.05) zinc than all other sources of rice bran. Gross energy, AEE, and copper were greater (p<0.05) in full-fat rice bran compared with defatted rice bran, but defatted rice bran contained more (p<0.05) crude protein, ash, insoluble dietary fiber, total dietary fiber, AA, and some minerals than full-fat rice bran. Conclusion: Banana meal is a high-energy source that can be used as an alternative ingredient in livestock diets. Full-fat rice bran from Australia and Thailand contained more concentrations of AEE and AA than samples from the Philippines or Vietnam. Full-fat rice bran had more gross energy and AEE than defatted rice bran, whereas defatted rice bran contained more crude protein, ash, and total dietary fiber.

• Natural Product Sciences
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• 제25권1호
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• pp.38-43
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• 2019

Microbial wound infection prolonged the hospitalization and increase the cost for wound management. Silver is commonly used as antimicrobial wound dressing. However, it causes several adverse side effects. Hence, this study was aimed to evaluate the antimicrobial efficiency of Swietenia macrophylla seed extract on clinical wound pathogens. Besides, the bioactive constituents of the seed extract were also determined. S. macrophylla seeds were extracted with methanol by maceration method. The seed extract inhibited 5 test bacteria and 1 yeast on disc diffusion assay. The antibacterial activity was broad spectrum, as the extract inhibited both Gram positive and Gram negative bacteria. On kill curve analysis, the antibacterial activity of the seed extract was concentration-dependent, the increase of extract concentration resulted in more reduction of bacterial growth. The extract also caused 99.9% growth reduction of Bacillus subtilis relative to control. A total of 21 compounds were detected in gas chromatography- mass spectrometry analysis. The predominant compounds present in the extract were oleic acid (18.56%) and linoleic acid (17.72%). In conclusion, the methanolic extract of S. macrophylla seeds exhibited significant antimicrobial activity on clinical wound pathogens. Further investigations should be conducted to purify other bioactive compounds from the seeds of S. macrophylla.

• Analytical Science and Technology
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• 제11권2호
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• pp.125-129
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• 1998

The purpose of this study was to give a quantitative analysis for assessing the tarnish resistance of alloys at the artificial saliva, 0.9% NaCI solution and Ringer's solution. In light of development in low-nobility alloys, it is important that tarnish test is standardized to analyse the tarnish properties of the compositions. There are concerns with the long term chemical stability of these alloys and the resistance to tarnish. Chemical stability is a complex problem involving alloy composition, nobility, microstructure and environment.

• The Bulletin of The Korean Astronomical Society
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• 제43권1호
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• pp.63.3-63.3
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• 2018

A comparison study between two low temperature opacity tables has been conducted. The opacity is the one of the major input physics in stellar model construction. Opacity is generally provided in a tabular form and as a function of 3 parameters, ie, density, temperature and chemical composition. Among available opacity tables, it has been common practice to utilize OPAL opacity table (Iglesias & Rogers, 1996) augmented with Ferguson opacity table (Ferguson et al. 2005) for the low temperature domain. For low temperature domain, another table, AESOPUS (Marigo & Aringer, 2009), has been announced in 2007. Reportedly, this opacity covers even lower temperature region, and is compatible with that of Ferguson in the overlapping temperature domain. To test the compatibility, stellar models and isochrones for various ranges in mass, metallicity and chemical composition, have been constructed. It is confirmed that there is no significant difference in the stellar models and isochrones constructed with the two different low temperature opacities. Therefore, in the construction of stellar models and isochrones, Ferguson low temperature opacity can be replaced with the AESOPUS opacity. The wider range in the temperature and chemical mixtures, and the easier accessibility make AESOPUS favorable in practical purpose.

• Journal of the Korean Applied Science and Technology
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• 제25권1호
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• pp.1-14
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• 2008

To prepare weather-resistant modified silane acrylic resin coatings for an architectural purpose, tetrapolymers were synthesized by radical polymerization. 3-Methacryloxypropyltrimethoxysilane (MPTS) as a silicone monomer and n-butyl acrylate, methyl methacrylate, and n-butyl methacrylate as acrylic monomers were used. The composition of monomers was adjusted to fix the glass transition temperature of acrylic polymer for $20^{\circ}C$. The composition of MPTS in the synthesized polymer were varied from 10 wt% to 30 wt%. On the basis of synthesized resin amber paints were prepared and their physical properties and effects on weatherability were examined. The presence of MPTS in modified silane acrylic resins generally resulted in low molecular weight and broad molecular weight distribution, and also lowered the viscosity of the copolymers. The coated films prepared from these resins showed good and balanced properties in general. Adhesion to the substrate was outstanding in particular. Weatherability tests were carried out in three different types such as outdoor exposure, QUV, and SWO. The test results showed that the modified silane acrylic resins containing 30 wt% of MPTS had superior weathering properties.