• Environmental Engineering Research
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• 제18권3호
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• pp.163-168
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• 2013

In this study, an innovative media, iron mixed ceramic pellet (IMCP) has been developed for arsenic (As) removal from groundwater. A porous, solid-phase IMCP (2-3 mm) was manufactured by combining clay soil, rice bran, and Fe(0) powder at $600^{\circ}C$. Both the As(III) and As(V) adsorption characteristics of IMCP were studied in several batch experiments. Structural analysis of the IMCP was conducted using X-ray absorption fine structure (XAFS) analysis to understand the mechanism of As removal. The adsorption of As was found to be dependent on pH, and exhibited strong adsorption of both As(III) and As(V) at pH 5-7. The adsorption process was described to follow a pseudo-second-order reaction, and the adsorption rate of As(V) was greater than that of As(III). The adsorption data were fit well with both Freundlich and Langmuir isotherm models. The maximum adsorption capacities of As(III) and As(V) from the Langmuir isotherm were found to be 4.0 and 4.5 mg/g, respectively. Phosphorus in the water had an adverse effect on both As(III) and As(V) adsorption. Scanning electron microscopy results revealed that iron(III) oxides/hydroxides are aggregated on the surface of IMCP. XAFS analysis showed a partial oxidation of As(III) and adsorption of As(V) onto the iron oxide in the IMCP.

• 융합보안논문지
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• 제20권3호
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• pp.3-11
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• 2020

사회관계망서비스(SNS)는 무료이지만 통신사에 지불하는 데이터 이용요금과 회원의 정보는 직·간접으로 제공이 되어야 한다. 그리고 SNS는 스마트 폰과 PC 등 송·수신 기기의 사양이 날로 높아가는 반면에 주로 단문 메시지를 이용하여 작업지시 등을 하는 오염지역이나 반도체 제조공장 등 특수 환경에서 범용 전송 프로토콜을 이용하는 것은 기기조작이 자유롭지 못하고, 보안에 취약한 문제점을 가지고 있다. 본 논문은 위험과 오염 그리고 크린 존(clean zone)등 특수 환경에서 웨어러블을 지향하는 저전력 저비용의 메시지 전송 프로토콜 IMCP를 ATmega128 기반으로 구현하여 동작 시험 통하여 실용성 검증하였다.