• Analytical Science and Technology
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• v.19 no.2
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• pp.163-171
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• 2006

This study was performed to develop an analytical method in specified wastes for preventing the environmental pollution from hazardous wastes. Few analytical methods were developed using the waste standard reference materials of sludge, waste oil, bottom ash, etc. which contain As, CN, Cd, Cr, Cu, Pb, and Hg compounds. The pre-treatment method was considered by whether or not the synchronous analysis is possible. Waste samples obtained from the 34 representative facilities, which are emitting the hazardous substances, were analyzed.

• Journal of the Korean Society of Radiology
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• v.8 no.6
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• pp.333-338
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• 2014

The fact is that in addition to an increase in social needs that must be managed systematically unnecessary exposure in the field of medical Recent important that the shield has emerged. However, products that are now in practical use, are not subdivided as compared to various medical radiology. Therefore, in the present study, we tried to present with the help of Monte Carlo simulation the structure of the shielding material that has been optimized. Simulated estimation result, the energy of the mammography for (30 kVp) spectrum, check the shielding rate of 90% or more $30{\mu}mPb$, at 2 mmAl case of shielding material of a single, at design time of 1 mmAl and 0.03 mmPb a double shield structure it is determined that more efficient. Also, check the blocking rate of 90% or more $340{\mu}mPb$, at 30 mmAl energy captured general in (80 kVp) spectra, it is considered that a double shield structure, design 1 mmAl and 0.3 mmPb is useful. These results, be used as basic material for the development of commercialization customized products for dose reduction is expected.

• Proceedings of the KAIS Fall Conference
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• 2002.05a
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• pp.67-69
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• 2002

주얼리 제품에서 마스터패턴 제작비는 최종제품의 20% 정도로 전체 주얼리제품 시장에서 매우 큰 비중을 차지한다. 기존 주얼리 제품을 제작하는 일반 공정인 ‘디자인 시안→상세도면 제작→1왁스형 제작→석고 플라스크 제작→은 마스터패턴의 제작→왁스패턴의 대량생산→정밀주조→최종제품’의 복잡한 단계를 ‘CAD 디자인 시안→쾌속조형기 듀라폼 음각몰드 제작→저융점 합금으로 마스터패턴 제작→정밀주조→최종제품’의 공정으로 단순화하면서도 대폭시간을 단축할 수 있는 신공정을 제안하였다. 주요공정인 selective laster sintering (SLS)형 쾌속조형기(rapid prototype: RP)를 이용해서 분해온도가 190℃인 듀라폼 분말로 미리 3D CAD로 설계한 직경 20mm의 구, 링 요소를 각각 상하형의 합체형 몰드와 일체형 몰드로 제작하였다. 제작된 몰드에 융점이 70℃인 Pb-Sn-Bi-Cd 저융점 합금을 주입하여 마스터패턴을 제조하였다. 완성된 마스터패턴은 목표형상에 비해 치수 변형율이 2% 이내로 우수하고 주입공정 및 후가공공정이 용이하여 주얼리용 마스터패턴으로 응용이 가능하였다.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.7
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• pp.112-119
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• 2009

The purpose of this study is to evaluate the evaluation of process yield performed by using Sn & Cu treatment on the surface to optimize process condition for Lead-free solder application. The materials which are used for the New Surface Treatment study are Semi-Dulling plating for high speed Sn/Cu alloy of Soft Alloy GTC-33 Pb free known as "UEMURA Method" and plating substrate is alloy 42.Especially in lead-free plating process, it is important to control plating thickness and Copper composition than Sn/Pb plating. Evaluated and controlled plating thickness $12{\pm}3um$, Copper composition $2{\pm}1%$, plating particle and visual inspection. The optimization of these parameters and condition makes it makes possible to apply Sn/Cu Lead-free solder from Sn/Pb alloy.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.2
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• pp.127-138
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• 2014

As increasing concerns about potential risks and hazards in children's products, the laws and regulations for heavy metals and phthalate retardants contained in the children's products have been reinforced in many countries. Especially, in Korea, environment and health laws and regulations for children's products was declared in 2009. This study was researched in terms of contents and migration of phthalates and heavy metals in 124 children's products sold in the Korean market. The results for contents of heavy metals showed that 123 products contained different 14 heavy metals depending on kinds of products. As the results of migration by sucking, the heavy metals in the products such as black, plastic dolls, wood toys, and bottom mat for swimming were transferred into extraction solution. Ba, Cu, Zn, and Sn were transferred from most of these products into the extraction solution and Co, Ni and Pb were additionally transferred into several products. As the results of migration through a skin, while Ba, Cu, and Zn were transferred from most products containing the heavy metals, as for accessories, Cr, Ba, Ni, Zn, and Cu were migrated. The results of contents of phthalates presented that 21 products contained DBP, DEHP and DINP. Only 2 products showed the migration of DEHP by sucking. DEHP in most products were transferred and DBP for 2 products and DINP for 7 products were migrated.

• Journal of Food Hygiene and Safety
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• v.22 no.1
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• pp.52-56
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• 2007

In order to offer monitoring data about standard and specification of metallic kitchenware, we carried out the material test and migration test of lead and antimony in 71 kinds of kitchenwares. As a result of this study, Pb was detected less than 0.06% at the material test and Sb was not defected in 71 kinds of kitchenwares. Pb was also detected less than 0.41 mg/L at the migration test. Currently according to the Food Code of Korea, Pb and Sb in metal product shall not exceed 10% and 5%, respectively and Pb migrated from metal product shall not exceed 1.0 mg/L. Therefore, our all data are not exceeding the standard and specification of metal product and show that all the kitchenwares in domestic circulation may be safe.

• Journal of Distribution Science
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• v.10 no.10
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• pp.35-43
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• 2012

Purpose - The current analysis has been done in order to verify the difference between consumer attitudes on the distributor's PB products in terms of practical shopping value and attitudes about the product according to its perceived quality. Research design, data, and methodology - The target respondents of this study were those who have bought PB products at large-scale discount stores within the past six months. We asked homemakers, office workers, and students who live in Seoul or Daejon to respond to a questionnaire by filling out self-evaluations, and collected the completed questionnaires. To test the hypothesis, a t-test was carried out by group for 25 percent of the high and low rankings, including a quarter of the total respondents, to verify attitudes toward products and brands, purchase satisfaction, and re-purchase intention according to the practical shopping value and recognized quality of PB products. A variance analysis was conducted to see if there were differences among groups in terms of practical shopping value and perceived quality. Scheffe's back testing was used to identify differences between groups. Results - The result of the investigation of consumer attitudes according to practical shopping value is as follows. First, it was verified that consumer attitudes about PB products increase as practical shopping value increases. Second, there was no significant. Third, it was verified that repurchase intentions for PB products get higher as the practical shopping value of the consumer increases. The following is the result of the investigation of consumer attitudes according to the perceived quality of PB products. First, it was verified that the product attitude improves as the perceived quality of PB products increases. Second, the research confirmed that the brand attitude improves as the perceived quality of PB products increases. Third, consumer satisfaction is higher when the perceived quality of PB products is high. Fourth, this study verified that repurchase intentions for PB products are higher as the perceived quality of the product increases. Finally, the results of identifying differences between groups for perceived quality and shopping value are as follows. It was identified that there were differences in shopping value according to the characteristics of the groups. However, perceived quality does not change according to the characteristics of groups. Conclusions - These results have practical implications for the marketing strategy of PB products in order to satisfy consumer demands and provide a differentiated service by the distributor. In addition, it is suggested that a communication strategy may be necessary to increase brand loyalty and ensure the continual growth and value creation of PB products as symbolic products for distributors.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2012.05a
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• pp.136-136
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• 2012

최근 전자제품의 크기가 소형화, 고성능화 되어감에 따라 전자제품을 구성하는 부품 크기도 작아지고, 배선의 피치 또한 미세화 되고 있다. 따라서 패키징 과정도 미세하고 정확한 제어를 필요로 하게 되었으며, 전해도금을 통한 정밀 패키징 공정이 도입되고 있다. 그러나 기존에는 패키징용 메인기판과 부품을 연결하는 솔더는 기존의 Sn-Pb 조성의 납을 포함하는 소재가 사용되었다. 하지만 납의 환경적 문제에 의해 사용을 금지하게 된 상태로 이를 대체하기 위한 무연 조성의 솔더가 연구되고 있다.

• Journal of Welding and Joining
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• v.31 no.3
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• pp.22-30
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• 2013

Due to ELV banning, automotive electronics cannot use four kinds of heavy metal element (Pb, Hg, Cd, $Cr^{6+}$) from 2016. Therefore, this study was focused on degradation characteristics of Sn-3.0Ag-0.5Cu Lead-free solder joint with OSP and ENIG finsh under various reliability assessment method, as like to thermal shock test and high temeprature/high humidity test with test duration for cabin electronics. Also, we compared bonding strength degradation to other advanced research results of electronic control unit for engine room because of difference service temperature with mount location in automotive. Whisker growth phenomenon and mitigation method which were essentially consideration items for Pb-free car electronics were examined. Conformal coating is a strong candidate for mitigating whisker growth in automotive electronics. Necessary condition to adapt Pb-free in car electronics was shown.

• Journal of the Korean Wood Science and Technology
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• v.19 no.4
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• pp.18-26
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• 1991

This study was carried out to examine not only the effect and the process of activation of aluminum sulfate for the manufacture of PB and MDF, but also application of the activation treatment to PB and MOF made with MDI adhesive. The results were as follows: 1. For the manufacture of PB, activating effect did not take place Because the low moisture content of 30% in the process of activation treatment made probably insufficient activation. It needs to examine higher moisture content for the uniform and enough activation same as that of MOF. 2. In the case of MOF, Activating effect was excellent, it showed not only better results of MOR 48%, MOE 29%, IB 60% than those of the control but also better dimensional stability. 3. Application of alum activation to the PB and MDF made with MDI adhesive yielded no effects. Maybe it was the reson that the curing mechanism of MDI is different. 4. Modifing the wood surface was the oxidation and wettability was not the variable limiting glueline performance. It is necessary to make a more study about activating reaction.