• Title/Summary/Keyword: EuP

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A study on the analysis of rare earth elements by differential pulse anode stripping voltammetry (시차펄스 양극벗김 전압-전류법에 의한 희토류 원소의 분석에 관한 연구)

  • Kim, Jae-Kyun;Cha, Ki-Won
    • Analytical Science and Technology
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    • v.18 no.5
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    • pp.369-375
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    • 2005
  • The differential pulse anode stripping voltammograms of some rare earth elements and their complexes with catechol have been investigated in various pH and electrolytes. In a 0.1 M LiCl and pH 5.3 solution, $Euv^{3+}$ and $Pr^{3+}$ showed a single oxidation peak at -0.2 V and the oxidation currents were linearly increased with the concentration of those ions. $Tm^{3+}$, $Tb^{3+}$, $Yb^{3+}$ and $Sm^{3+}$ showed two oxidation peaks at -0.5 V and -0.2 V and the oxidation currents at -0.5 V were increased with the concentration increase of those ions. The linear range of those calibration curves was in 1 ppm-10 ppm. In the case of voltammograms of catechol complexes of rare earth elements, $Tb^{3+}$-catechol and $Eu^{3+}$-catechol complex showed a single oxidation peak at -0.95 V and -0.65V, respectively and $Sm^{3+}$-catechol, $Pr^{3+}$-catechol, $Tm^{3+}$-catechol and $Yb^{3+}$-catechol complexes showed two oxidation peaks. The linear range of the calibration curves of those complex was 0.1 ppm~1.0 ppm.

Phylogenetic Analysis on Wild Cordyceps Collected from Miryang Region of South Korea (밀양근교에서 채집한 야생 동충하초 계통의 PCR 산물에 근거한 계통 유전학적 연구)

  • Park, Hyeancheal;Lee, Sangmong;Park, Namsook
    • Korean Journal of Plant Resources
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    • v.34 no.1
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    • pp.1-16
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    • 2021
  • The phylogenetic relationships among thirty-two strains (P1~P32; including Cordyceps sp., Paecilomyces sp., Beauveria sp., Aranthomyces sp., Isaria sp. and Himenostilbe sp.) in Miryang region located in the southern part of Korea, were investigated based on internal transcribed spacer (ITS) sequences of ribosomal DNA. A fragment of ITS region was amplified by polymerase chain reaction (PCR) using the specific primer pairs ITS1 and ITS4. After obtained same size of PCR products from various strains, we cloned them into a pGEM-T easy vector to determine their sequences. BLAST analyses of the nucleotide sequence ITS1, 5.8S and ITS2 gene fragments revealed the identity and their phylogenetic relationship. Among 32 strains isolated from Miryang region, Cordyceps militaris was shared 100% sequences with Genbank (AY49191, EU825999, AY491992), while some species are not shared perfectly with reported sequences. For example, strain P17 (P. tenuipes in Ulju-gun Gaji Mountain) has some differences among the other strains of P. tenuipes (Miryang-si Jocheon-eup, Miryang-si Gaji Mountain) and those of gene bank. We conclude that ITS analyses with strains in the suburbs of Miryang in this study can be effectively used as a tool for classification, evaluation and collection of the natural eco-type genetic resources.

Comparison of the Detection Efficiency $a-Se_{1-x}As_x$ in X-ray Detection Sensor of $Gd_2O_2S(Eu^{2+})/a$-Se Structure ($Gd_2O_2S(Eu^{2+} )/a$-Se$ 구조의 X선 검출 센서에서 $a-Se_{1-x}As_x$의 검출효율 비교)

  • Kang, Sang-Sik;Park, Ji-Koon;Lee, Dong-Gil;Mun, Chi-Wung;Nam, Sang-Hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.11a
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    • pp.436-439
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    • 2002
  • Recently, It has performed that the basic research of the photoconductive material and the development and application of the digital radiograph detector which is divided into the direct and indirect method. The objective of this study investigate the effect of the electric characteristic about changing the composition of Arsenic in hybrid detector system for compensating a defect of conventional. We fabricated samples using the amorphous Selenium and Arsenic alloy with various concentrations of the Arsenic{seven step 0.1%, 0.3%, 0.5%, 1%, 1.5%, 3%, 5%). And using EFIRON optical adhesives the formed multi-layer$(Gd_{2}O_{2}S(Eu^{2+}))$ composed phosphor layer. X-ray and light sensitivity was measured to study x-ray response characteritics. As results, highest value was measured as output net charge and SNR were $315.7pC/cm^2/mR$ and 99.4 at 0.3%As doping ratio.

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Understanding and Improvement of the K-BREF (Korea BAT reference documents) for the Corrugated Cardboard Manufacturing Industry (골판지원지 제조업 최적가용기법 기준서의 이해와 개선사항)

  • Seo, Kyungae;Kim, Eunseok;Kim, Gahee;Khan, Jongbeom;Hong, Sukyoung;Kang, Philgoo
    • Journal of Environmental Science International
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    • v.29 no.5
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    • pp.559-573
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    • 2020
  • The purpose of this study analyzed the overview of corrugated cardboasrd manufacturing industry and then provide direction for improvement. The BREF (BAT reference document) is an important reference for licensees and officer, including the best available techniques for the industry and achievable environmental performance, technical characteristics, and economic information. In the corrugated cardboard manufacturing process, wastewater pollutants are generated throughout the production process, and water is used in the dissociation and aging process. Atmospheric emissions are mostly generated by steam production from boilers and incinerators for the dry process. SO2, NOx, CO2, CO, HCl, dust, VOC, and odor were common. In the EU-BREF (European union BAT reference documents) BAT for wastewater have taken up a relatively large proportion. Items of water pollutants in wastewater were common in COD, BOD, N, P, SS, and however EU-BREF had different pollutants such as AOX and salt compared to K-BREF. In order to improve the quality of the K-BREF, it is necessary to devise basic data research method and data acqusitiom method. Consideration should be given to additional environmental management techniques that reflect the emissions characteristics of the corrugated cardboard manufacturing process. In addition, further research is needed to develop methodologies for selecting BATs considering environmental and economic feasibility.

Geochemistry and Petrogenesis of Pan-african Granitoids in Kaiama, North Central, Nigeria

  • Aliyu Ohiani Umaru;Olugbenga Okunlola;Umaru Adamu Danbatta;Olusegun G. Olisa
    • Economic and Environmental Geology
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    • v.56 no.3
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    • pp.259-275
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    • 2023
  • Pan African granitoids of Kaiama is comprised of K-feldspar rich granites, porphyritic granites, and granitic gneiss that are intruded by quartz veins and aplitic veins and dykes which trend NE-SW. In order to establish the geochemical signatures, petrogenesis, and tectonic settings of the lithological units, petrological, petrographical, and geochemical studies was carried out. Petrographic analysis reveals that the granitoids are dominantly composed of quartz, plagioclase feldspar, biotite, and k-feldspar with occasional muscovites, sericite, and opaque minerals that constitute very low proportion. Major, trace, and rare earth elements geochemical data reveal that the rocks have moderate to high silica (SiO2=63-79.7%) and alumina (Al2O3=11.85-16.15) contents that correlate with the abundance of quartz, feldspars, and biotite. The rocks are calc-alkaline, peraluminous (ASI=1.0-<1.2), and S-type granitoids sourced by melting of pre-existing metasedimentary or sedimentary rocks containing Al, Na, and K oxides. They plot dominantly in the WPG and VAG fields suggesting emplacement in a post-collisional tectonic setting. On a multi-element variation diagram, the granitoids show depletion in Ba, K, P, Rb, and Ti while enrichment was observed for Th, U, Nd, Pb and Sm. Their rare-earth elements pattern is characterized by moderate fractionation ((La/Yb)N=0.52-38.24) and pronounced negative Eu-anomaly (Eu/Eu*=0.02-1.22) that points to the preservation of plagioclase from the source magma. Generally, the geochemical features of the granitoids show that they were derived by the partial melting of crustal rocks with some input from greywacke and pelitic materials in a typical post-collisional tectonic setting.

미국테러사태 이후의 미국의 통상정책과 하이닉스 문제에 대한 미국의 입장

  • Korea Electronics Association
    • Journal of Korean Electronics
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    • v.21 no.11
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    • pp.24-32
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    • 2001
  • 최근 세계통상환경은 WTO 뉴라운드 출범, EU의 일반특혜관세 개정, 전자제품 환경문제 등 중요한 변수가 산재해 있으며 여기에 9월 11일 미 테러 사태로 인한 미국의 대외통상정책 변화 가능성 등 예기치 못했던 새로운 무역환경이 대두되고 있어 본회 국제 통상 팀에서는 지난 9월 25일 한국과학기술회관에서 "전자산업 국제 통상 세미나"를 개최하였다. 이에 본란에서는 미국의 저명한 로펌인 Kaye Scholer사에 근무하면서 다년간 한국관련 통상케이스를 직접 담당해온 Mr. Michael P.House가 발표한 자료를 요약 정리하였다.

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Effects of Dissolved Oxygen and Agitation on Production of Serratiopeptidase by Serratia Marcescens NRRL B-23112 in Stirred Tank Bioreactor and its Kinetic Modeling

  • Pansuriya, Ruchir C.;Singhal, Rekha S.
    • Journal of Microbiology and Biotechnology
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    • v.21 no.4
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    • pp.430-437
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    • 2011
  • The effects of the agitation and aeration rates on the production of serratiopeptidase (SRP) in a 5-L fermentor (working volume 2-l) were systematically investigated using Serratia marcescens NRRL B-23112. The dissolved oxygen concentration, pH, biomass, SRP yield, and maltose utilization were all continuously measured during the course of the fermentation runs. The efficiencies of the aeration and agitation were evaluated based on the volumetric mass transfer coefficient ($K_La$). The maximum SRP production of 11,580 EU/ml with a specific SRP productivity of 78.8 EU/g/h was obtained with an agitation of 400 rpm and aeration of 0.075 vvm, which was 58% higher than the shake-flask level. The $K_La$ for the fermentation system supporting the maximum production (400 rpm, 0.075 vvm) was 11.3 $h^{-1}$. Under these fermentor optimized conditions, kinetic modeling was performed to understand the detailed course of the fermentation process. The resulting logistic and Luedeking-Piret models provided an effective description of the SRP fermentation, where the correlation coefficients for cell growth, SRP formation, and substrate consumption were 0.99, 0.94, and 0.84, respectively, revealing a good agreement between the model-predicted and experimental results. The kinetic analysis of the batch fermentation process for the production of SRP demonstrated the SRP production to be mixed growth associated.

Development of Superior Fe-Si Sintered Magnetic Cores Equivalent to Wrought Si-steels

  • Hamano, Aya;Isihara, Chio;Asaka, Kazuo
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2006.09b
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    • pp.799-800
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    • 2006
  • Wrought Si-steels are generally used for electromagnetic valves, which are needed good response. To date, Hitachi Powdered Metals Co., Ltd. have produced Fe-Si base sintered magnetic material, EU-52, which shows a magnetic flux density of more than 1.25T at 2000A/m and a maximum permeability of more than 3500. However these magnetic properties are lower than that of wrought Si-steels. Because EU-52 has a low density of $7.2Mg/m^3$. For improving the magnetic properties, it is necessary to increase the density of sintered cores. To increase density, a new mixing method of coating fine Si powders on atomized iron powders was developed, for avoiding the Kirkendall effect. As the result, developed P/M Fe-Si magnetic cores shows higher density of $7.38Mg/m^3$, higher magnetic flux density of 1.48T at 2000A/m and higher maximum permeability of 6800.

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A Study on Strengthening Domestic Personal Information Impact Assessment(PIA)

  • Young-Bok Cho
    • Journal of the Korea Society of Computer and Information
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    • v.29 no.6
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    • pp.61-67
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    • 2024
  • In this paper, we presented a strengthening plan to prevent personal information leakage incidents by securing legal compliance for personal information impact assessment and suggesting measures to strengthen privacy during personal information impact assessment. Recently, as various services based on big data have been created, efforts are being made to protect personal information, focusing on the EU's GDPR and Korea's Personal Information Protection Act. In this society, companies entrust processing of personal information to provide customized services based on the latest technology, but at this time, the problem of personal information leakage through consignees is seriously occurring. Therefore, the use of personal information by trustees.