• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.21 no.5
• /
• pp.397-401
• /
• 2008

Most of the topic in PCB industry was about increasing the volume of product for the development of electronics in numerous industrial application area. However, it has been emerged that yield improvement quality manufacturing via detecting any suspicious process in order to minimize the scrapped product and material waste. In addition, recently, restriction of hazardous substances (RoHS) claims that electronic manufacturing environment should reduce the harmful chemicals usage, thus the importance of monitoring copper etchant and detecting any mis-processing is crucial for electronics manufacturing. In this paper, we have developed real-time chemical monitoring system using RGB sensor, which is simpler but more accurate method than commercially utilized oxidation reduction potential (ORP) technique. The developed Cu etchant monitoring system can further be utilized for copper interconnect process in future nano-semiconductor process.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2007.06a
• /
• pp.148-149
• /
• 2007

현재 전자부품 시장은 RoHS 규정으로 인하여 lead free화가 진행되고 있으며 많은 주목을 받고 있다. 본 논문에서는 반도체 패키지 및 부품표면일장에서 사용 되는 무전해 주석 도금과정 중 산 탈지 후 막의 표면 거칠기 정도가 도금 후의 표면 거칠기 정도에 미치는 영향을 평가 한다. 실험의 효율성을 높이기 위해 통계적인 실험계획법을 사용하였으며 실험의 횟수를 줄이고 표면 거칠기 정도는 이미지 프로세싱을 통하여 분석하였으며 통계적인 모델링을 통해 micro etch가 도금 표면의 거칠기에 주는 영향을 분석하였다.

• Korean Journal of Head & Neck Oncology
• /
• v.13 no.1
• /
• pp.9-15
• /
• 1997

Malignant histiocytosis(MH)-like hemophagocytic syndrome(HS) is a fatal complication of nasal angiocentric lymphoma(AL) and difficult to distinguish from MH. Ten of total 42 patients with nasal AL had HS and 9 of them were initially suspected to have MH. Five patients had HS as initial manifestation, 3 at the time of relapse, and 2 during the clinical remission of lymphoma. Four patients were treated by combination chemotherapy(CHOP) and others had only supportive care. Immunohistochemical study and in situ hybridization were performed on the specimen obtained from 10 patients. The median survival of all patients from HS was 18 days(range 2 - 44 days) and all had fatal outcome regardless of the treatment-modality. All cases were positive for UCHL1(CD45RO) and Epstein-Barr virus (EBV) by EBER in situ hybridization. MH-like HS is a fatal complication of nasal AL and has a high association with EBV. Reactivation of EBV may contribute to HS and further investigation of predictive factors and effective treatment of HS should be pursued in future.

• Journal of the East Asian Society of Dietary Life
• /
• v.27 no.3
• /
• pp.348-363
• /
• 2017

We analyzed the mixed culture characteristics of isolated brewing fungi obtained from Korean traditional nuruk for their development as fermentation starters. In a previous study, we selected appropriate fungi strains based on their large fungi bodies and strong enzyme activities. These fungi strains were mixed cultured under various combination of ratios, pHs and temperatures. As a result, total acidities of R. delemar mixed culture media were higher than those of A. oryzae cultured at $20^{\circ}C$ and $37^{\circ}C$. The pHs of A. luchuensis 34-1 and A. oryzae 37-7 as well as R. delemar 58-8 and A. oryzae 37-7 mixed culture media gradually increased with the culture period. On the contrary, total acidities of the mixed culture media gradually decreased. ${\alpha}-Amylase$ activities of R. delemar 26-4 and R. oryzae 82-7 mixed culture media were strong at $20^{\circ}C$ and pH 4, glucoamylase activities of R. delemar 58-8 and A. oryzae 37-7 were strong at $37^{\circ}C$, pH 3 and 1:2 ratio, and acidic protease activities of R. delemar 26-4 and A. oryzae 78-5 were strong at $20^{\circ}C$, pH 4 and 1:4 ratio. This study provides the optimal mixed culture conditions for fermentation starters based on changes in pH and total acidity, favorable enzyme activities, and fungi varieties.

• Journal of Korean Society of Environmental Engineers
• /
• v.39 no.4
• /
• pp.180-185
• /
• 2017

For the management of mercury-containing products, the products were selected to do material flow analysis in preference of not having selected in previous studies. Domestically mercury have been added to pigment for prevention of bacterial growth. So, in this study paint containing pigment was selected as a target. 71 samples of paint products collected in 2014 and data of 38 samples of wastes (dust, sludge, paint) analyzed in 2010 were used in material flow analysis. The result shows that mercury was 0~0.25 mg/kg in products and 0.23~0.69 mg/kg in the wastes. In the material flow analysis, the amount of flow in the process of distribution was 10.06 kg/year, but the amount of flow in disposal like a landfill, incineration and recycling was much than distribution as 25.27 kg/year. It was caused by different sampling period between collecting products and data of wastes. Therefore, It could be possible to be affected from regulation by RoHS like decreasing usage of mercury in paint products or eradicated in the industry. Mercury contents in current paint products are very low to affect discharging to the environment.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.36 no.11B
• /
• pp.1383-1388
• /
• 2011

Due to many recent activities on enforcement of the intensified environmental regulation such as the policies of curbing the greenhouse gas and the Restriction of Hazardous Substances (RoHS), the usage of Light emitting diode (LED) has been rapidly increased and energy efficient management of LED light system is regarded as an important technology to enhance the energy efficiency. In this paper, we propose an energy-efficient control scheme of LED light, being composed of multiple light sources. The proposed scheme controls the intensity of LED light source to minimize the total intensity while providing the quality of lighting service. The intensity of light is assumed to be proportional to power consumption, thus the objective is to minimize the total power consumption. A linear programming problem is formulated to find the optimal intensity of each light source and procedure to apply the proposed scheme in the real system is suggested. The performance evaluation results elucidate that the proposed scheme achieves over 20% improvement in power consumption of light intensity in comparison with the conventional dimming control scheme.

• Analytical Science and Technology
• /
• v.25 no.5
• /
• pp.273-283
• /
• 2012

Phthalate plasticizers are regulated by RoHS, REACH and CPSC as hazardous substances. Responding to these international environmental restrictions, we developed ABS certified reference material (CRM) for determination of phthalate plasticizers such as DMP, DEP, DBP, BBP, DEHP and DnOP. The candidate material has been made with ABS resin widely used in electric and electronic products and 6 kinds of phthalate plasticizers. The making of the material involved a series of processes like extruding, cooling, pelletizing, and drying using twin screw extruder. Then it has been certified according to ISO Guide 35. Using isotope dilution-gas chromatography/mass spectrometry (ID-GC/MS), homogeneity, short-term stability, and long-term stability were evaluated. The certified values were determined by using primary reference material (PRM) of KRISS for traceability. From now on, we will provide ABS CRM to national and international companies and research institutes after certification as certified reference material and registering on COMAR (code of reference material).

• Journal of the Microelectronics and Packaging Society
• /
• v.26 no.4
• /
• pp.163-169
• /
• 2019

Sn-Pb solder alloys in electronics rapidly has been replaced to Pb free solder alloys because of various environmental regulations such as restriction of hazardous substances directive (RoHS), European Union waste electrical, waste electrical and electronic equipment (WEEE), registration evaluation authorization and of chemicals (REACH) etc. Because Sn58%Bi (in wt.%) solder alloy has low melting point and higher mechanical properties than that of Sn-Pb solder, it has been studied to manufacture electronic components. However, the reliability of Sn58%Bi solder could be lowered because of the brittleness of Bi element included in the solder alloy. Therefore, we observed the microstructures of Sn58%Bi composite solders with various contents of Sn-decorated multiwalled carbon nanotube (Sn-MWCNT) particles and evaluated bonding strength of the FR-4 components assembled with Sn58%Bi composite solder. Also, microstructures and bonding strengths of the Sn58%Bi composite solder joints were evaluated with the number of reflows from 1 to 7 times, respectively. Bonding strengths and fracture energies of the Sn58%Bi composite solder joints were measured by die shear test. Microstructures and fracture modes were observed with scanning electron microscope (SEM). Microstructures in the Sn58%Bi composite solder joints were finer than that of only Sn58%Bi solder joint. Bonding strength and fracture energy of Sn58%Bi composite solder including 0.1 wt.% of Sn-decorated MWCNT particles increased up to 20.4% and 15.4% at 5 times in reflow, respectively.

• Korean Journal of Plant Resources
• /
• v.37 no.2
• /
• pp.101-109
• /
• 2024

In this study, we investigated the antioxidant effects and active ingredients of Gynura Procumbens extracts obtained through various extraction methods for the development of natural-based cosmetics and pharmaceutical materials. The contents of compounds, total flavonoids, chlorogenic acid, and caffeic acid were compared at different concentrations, revealing the highest content of active ingredients in the 100% ethanol extract. Antioxidant activity assessed by DPPH and ABTS radical scavenging assays showed a concentration-dependent increase in antioxidant activity with the ethanol concentration. Additionally, we validated the DNA damage inhibition and anti-inflammatory effects of Gynura Procumbens extracts through UVB irradiation on Hs68 cell models. The 100% ethanol extract demonstrated significant inhibition of the expression of p-p53, γ-H2AX, iNOS, and COX-2 induced by UVB, indicating its potential in alleviating photodamage effects. Consequently, the efficient extraction of Gynura Procumbens for skin functional material development was confirmed, suggesting the suitability of ethanol or alcohol-based solvents.

• International Commerce and Information Review
• /
• v.14 no.3
• /
• pp.381-403
• /
• 2012

The purpose of this study is to examine Technology Trade of Korea China for Korea China FTA. For this purpose, to analysis the present condition of technology trade and Trade Specialization Index(TSI), Technical Barriers to Trade(TBT). The Technology trade of Korea China is the surplus Technology trade of Korea but reducing to surplus scale. Also as a result of TSI analysis, Chemistry, plastic, primary metal, Medical precision industry, basic materials industries have weakened the Korea. In addition to Technical Barriers to Trade of China is very complexity for example, China Compulsory Certificate(CCC), China RoHS, China REACH. Therefore the Policy Technology Trade of Kore against China have to the centerpiece of Korea Technology export drive to expand in China.