• Journal of Technologic Dentistry
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• v.7 no.1
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• pp.53-59
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• 1985

This paper aims to examine baes metal alloy in all its aspects - the roles of elements, the content of every element according to uses, characters, laboratory technique methods and the kind of artificial base metal alloy registered in A.D.A. Specification. The results are as follows; 1. Base metal alloy is used widely bacaues it is rather cheap, but it should be handled appropriately in operating because its quality is bad. 2. Classifying base metal alloy, it is classified into Co-Cr alloy, Ni-Cr alloy, and Ni-Cr-Co alloy according to element, it is classified into partial denture alloy, surgical alloy and crown & bridge alloy according to use. 3. Among elements of base metal alloy, Bellium lowers the melting point of the alloy and increases the strength, but the amount should be limited when it is used because it destroys the organization of a living body. 4. The investments for base metal alloy are ethyl silcate bonded investment and phosphate bonded investment which endure well at high burn out temperature. 5. A.D.A specification No.14 in Kore contains Niranium, Nobilium, regalloy, Ticonium and Vitallium.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.6
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• pp.449-453
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• 2009

This study focused on the content characteristics of regulated hazardous substances in specific wastes. Regulated heavy metal such as Cu, Pb, Cd analyzed the 108 waste samples that it choice from the representative facilities. Analytical method used content test method, suggested on the basis of analytical method of developing country, and the results as compared with limited standard in Austria Petroleum, primary metalworking and electronic industry had high content of Cu more than 100 mg/kg of Austria limited standard. Pb detected high level concentration the sample that dust producted at Primary metalworking industry. In case of total Cr was show that high content at KSIC 18, 19, 23 etc but result analyzed Cr(VI), it was shown that high level at dust producted from sewing clothes and fur industry.

• Korean Journal of Agricultural and Forest Meteorology
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• v.8 no.4
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• pp.222-228
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• 2006

This study was conducted to evaluate the heavy metal content (As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Zn) of forest soil and of Lonicera japonica and to understand the correlation in contents of heavy metal between forest soil and L. japonica near the Onsan industrial region. The content of As, Cd, Cu, Pb and Zn was higher in the industrial region than in forest regions, but re, Mn and Ni content was higher in forest regions than in the industrial region. Among heavy metals, the content of Cd, Cu, Pb and Zn in leaf, stem and root of L. japonica growing near industrial regions was significantly higher (p<0.05) than in forest regions. The content of As, Cd, Cu, Pb and Zn in L. japonica tissues showed a positive or negative correlation with those in forest soils. Correlation coefficients of Cu content between forest soil and organs of L. japonica ranged from 0.93 to 0.99 (p<0.01). It was concluded that L. japanica could be used in heavy metal (Cd, Cu, Pb, and Zn) decontamination of forest soils of industrial regions.

• Journal of the Korean Society of Fashion and Beauty
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• v.2 no.2 s.2
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• pp.93-100
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• 2004

This study is to measure the heavy metal content of permanent wave products which on marketing correctly as estimating the extent of exposure by a hair permanent wave scientifically. We would like to prevent an affair from arising health obstruction as to the heavy metal who is using those and also show the basic data for proposing the new standard. The results were as follows.: in case of the average heavy metal content for a wave type thioglycol acid ingredient includes 1.61ppm(Pb), 0.03ppm(Cd), 0.05ppm(Ni), 0.27ppm(Mn), 0.82ppm(Cu) and those were recognized the significant gap between products all the heavy metals. In case of a cysteine acid ingredient includes 0.86ppm(Pb), 0.01ppm(Cd), 0.05ppm(Ni), 0.20ppm(Mn) and 0.66ppm(Cu) and those were recognized the significant gap between products except a nickel. Straight type of permanent wave reductant includes 2.11ppm(Pb), 0.01ppm(Cd), 0.27ppm(Ni), 0.66ppm(Mn), 2.53ppm(Cu) and those were recognized the significant gap between products all the heavy metals. Permanent wave reducing agent includes 1.43ppm(Pb), 0.01ppm(Cd), 0.09ppm(Ni), 0.66ppm(Mn), 0.75ppm(Cu) and those were approved the significant gap between products except a cadmium. Exposure level of the heavy metal contents per onetime permanent waving were 242.3ppm(Pb), 2.5ppm(Cd), 17.7ppm(Ni), 89.0ppm(Mn), 174.7ppm(Cu).

• Journal of Welding and Joining
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• v.34 no.6
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• pp.42-46
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• 2016

Hydrogen assisted cracking (HAC) is one of the most complicated problem in welding. Huge amount of studies have been done for decades. Based on them, various standards have been established to avoid HAC. But it is still a chronic problem in industrial field. It is well known that the main causes of the hydrogen crack are residual stress, crack susceptible micro structures and a certain critical level of hydrogen concentration. Even though the exact generating mechanism is unclear till today, it has been reported that the hydrogen level in the weld metal should be managed less than a certain amount to prevent it. Matsuda studied that the residual hydrogen level in the weld metal can be varied even if the initial hydrogen content is same. It is also insisted in this report that the residual hydrogen concentration is in stronger correlation with hydrogen crack than the initial hydrogen content. But, in practical point of view, the residual hydrogen is still hard to consider because measuring hydrogen level is time and cost consuming process. In this regard, numerical analysis is the only solution for considering the residual hydrogen content. Meanwhile, Takahashi showed the possibility of predicting the residual hydrogen by a rigorous FE analysis. But, few commercial software suitable for solving the weld metal hydrogen has been reported yet. In this study, two dimensional thermal - hydrogen coupled analysis was developed by using the commercial FE software MARC. Since the governing equation of the hydrogen diffusion is similar to the heat transfer, it is shown that the heat transfer FE analysis in association with hydrogen diffusion property can be used for hydrogen diffusion analysis. A series of simulation was performed to verify the accuracy of the model. For BOP (Bead-On-Plate) and the multi-pass butt welding simulations, remaining hydrogen contents in the weld metal is well matched with measurements which are referred from Kim and Masamitsu.

• Conservation Science in Museum
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• v.28
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• pp.89-108
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• 2022

Among about 500,000 characters in metal types in National Museum of Korea, this study conducts a statistical analysis of 62 metal types from the early Joseon Dynasty, including 33 gabinja (甲寅字) types and 29 eulhaeja (乙亥字) Hangeul types by examining the shape, measuring the specific gravity, and identifying the components based on previously-studied Joseon metal types. Among them, 33 gabinja types and 24 eulhaeja types were made of two-component bronze (copper and tin) (Group A), and four eulhaeja types were produced with three-component bronze (copper, tin and lead). (Group B), and one eulhaeja type was created with two-component bronze (copper and tin) with a high tin content (Group C). By comparing with imjinja (壬辰字) types of the late Joseon Dynasty based on multiple statistical analyses of type components, this study confirms that late-Joseon types have low copper content and high zinc and lead content, and therefore it may be possible to distinguish between the types of early and late Joseon Dynasty.

• Journal of Life Science
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• v.19 no.11
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• pp.1562-1567
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• 2009

Heavy metal contamination levels in Andong reservoir and Imha reservoir were measured with heavy metal contents in both water and sediment, and analyzed with heavy metal accumulation level in inhabitant fish, Carassius auratus, using an inductively coupled plasma spectrometer and an atomic absorption spectrometer. High levels of heavy metal contents in water, sediment and the tissues of C. auratus were detected. Likewise, relatively high levels of As were detected in water and sediment from Andong reservoir. In addition, higher levels of Cr, Cu, Cd and As content were detected in muscle and bone tissues of fish from Andong reservoir than those from Imha reservoir. As a result, the heavy metal content of water, sediment and inhabitant fish, C. auratus, in Andong reservoir was higher than Imha reservoir. We proposed that heavy metal contamination in water and inhabitant fish is attributed to various metals derived from abandoned mines and farmlands that are upstream of Andong reservoir.

• Journal of Welding and Joining
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• v.5 no.4
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• pp.36-46
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• 1987

The impact toughness and SCC resistance of duplex stainless steel weldment made by GTAW, GMAW and SMAW processes was studied. The impact toughness of GTA weld metal was higher than that of GMA weld metal which contained more ferrite phase than GTA weld metal. The impact toughness of SMA weld metal was the lowest due to the harmful effect of inclusions inspite of richness of more ductile austenite phase. From these facts, it can be concluded that the important factors determining the weld metal toughness were the amount of ferrite phase and the cleaness of weld metal. While the SCC resistance of SMA weld metal was lower than that of base metal and nay other weld metal, the SCC resistance of GMA and GTA weld metal was higher than that of base metal but that of all the HAZ's were lower than that of base metal. Therefore, the impact toughness and SCC resistance of GTA and GMA weldment was pretty good as long as phase ratio was propertly controlled. Although the phase ratio was controlled, SMA weld metal could not get a good combination because the lack of shielding from the environment results in a high content of inclusions in weld metal.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.2
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• pp.87-92
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• 2015

The injection molding process is widely used in the production of most plastic products. In order to make metal-colored plastic products like those found in modern luxury home alliances, metallic pigments are mixed with a basic resin material for injection molding. However, process control for metal-colored plastic products is extremely difficult due to the non-uniform melt flow of the metallic resin pigments. In this study, the effect of process parameters on the quality of a metal-colored plastic product is evaluated. A rapid mold cooling method using a compressed cryogenic fluid is also proposed to decrease the content of undesired compounds within the plastic product.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2000.04a
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• pp.139-142
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• 2000

The SiCp/AC8A composites were fabricated by the pressureless metal infiltration process successfully. The effect of additional Mg, which were mixed with SiC particles to promote interfacial wetting between the reinforcement and matrix alloy, and particle size on the mechanical properties was investigated. By increasing the additional Mg content the hardness of SiCp/AC8A composites was increased due to the hard reaction products, but the bending strength was decreased by the excess reaction of Mg and high porosity level when the additional Mg content is over 7%. The Hardness and bending strength was increased by decreasing the size of SiC particle.