• 상하수도학회지
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• 제26권6호
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• pp.807-813
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• 2012

Flocculation and flotation are used as pretreatment steps prior to the reverse osmosis (RO) process. During seawater treatment, high temperature can change the water chemistry of seawater during the process of coagulation. It also affects bubble volume concentration (BVC) and bubble characteristics. Coagulants such as alum and ferric salts at $40^{\circ}C$ can also change flux rates in the seawater reverse osmosis (SWRO) process. In this study, the bubble characteristics in dissolved air flotation (DAF), used as a SWRO pretreatment process, were studied in synthetic seawater at $20^{\circ}C$ and $40^{\circ}C$. The flux of an RO membrane was monitored after dosing the synthetic seawater with coagulants at different temperatures. Results showed that BVC increases as the operating pressure increases and as the salt concentration decreases. The bubble size released at $40^{\circ}C$ is far smaller than that at $20^{\circ}C$The addition of a ferric salt is effective for turbidity removal in synthetic seawater at $20^{\circ}C$; it is more effective than alum. When synthetic seawater was dosed with a ferric salt, the RO membrane flux increased by 27 % at $40^{\circ}C$.

• Carbon letters
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• 제9권4호
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• pp.303-307
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• 2008

The studies on integrated operation of fuel cell with fuel processor are very essential prior to its commercialization. In this study, Polymer Electrolyte Membrane Fuel Cell (PEMFC) was operated with a fuel processor, which is mainly composed of two parts, methanol steam reforming reaction and preferential oxidation (PROX). In fuel processor, ICI 33-5 (CuO 50%, ZnO 33%, $Al_2O_3$ 8%, BET surface area: $66\;m^2g^{-1}$) catalyst and CuO-$CeO_2$ catalyst were used for methanol steam reforming, preferential oxidation (PROX) respectively. PEMFC was operated by hydrogen fuel generated from fuel processor. The resulting gas from PROX reactor is used to operate PEMFC equipped with our prepared anode and cathode catalyst. PtRu/C catalyst gives more tolerance to CO.

• Journal of Photoscience
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• 제4권3호
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• pp.133-140
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• 1997

A system for studying oxidative hemolysis has been used by controling UV-irradiation and concentration of a novel molecular probe, N,N'-bis(2-hydroperoxy-2-methoxyethyl)-1,4,5,8-naphthalenetetra-carboxylic diimide (NP-III), which generates hydroxyl radical upon longer wavelength photoirradiation (> 350 nm). NP-III induces 25~30% of hemolysis at low concentration (50 $\mu$M) for 3h-irradiation of UVA. The simultaneous treatment of N-ethylmaleimide (NEM) with NP-IH completely hemotyzed erythrocytes under the same conditions as NP-III alone by both decreasing thiol group and increasing lipid peroxidation in erythrocyte membrane. However. thiol-reducing agents prevented the protein-crosslinking and lipid peroxidation on the NEM-synergistic hemolysis by partially scavenging hydroxyl radical and maintaining the thiol group of erythrocyte membrane in the reduced state. In addition, erythrocytes pretreated with 2,2,5,7,8-pentamethyl-6-hydroxychromane (PMC), vitamin E homologue was able to delay and decrease the lipid peroxidation when compared to cells pretreated with both NEM and PMC. We suggest that the presence of reduced thiols in inner membrane protein by GSH can prevent the protein-crosslinking and the lipid peroxidation, and eventually prevent the oxidative hemolysis of erythrocyte.

• 멤브레인
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• 제25권3호
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• pp.295-300
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• 2015

PDMS에 NaA zeolite를 0~40 wt% 가하여 PDMS-NaA zeolite 막을 제조하였다. SEM 관찰에 의하면 PDMS-NaA zeolite 막 내에 분산되어있는 NaA zeolite 입자의 크기는 $2{\sim}5{\mu}m$이었다. PDMS-NaA zeolite 막의 $N_2$와 $H_2$ 투과도는 막 내의 NaA zeolite 함량이 증가하면 증가하였고, $N_2$보다는 $H_2$의 투과도가 더 컸다. 그리고 PDMS-NaA zeolite 선택성($H_2/N_2$)은 NaA zeolite 함량이 증가하면 증가하였다.

• 멤브레인
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• 제26권3호
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• pp.173-178
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• 2016

본 총설에서는 고분자와 은염으로 구성된 고분자 전해질 분리막과 장시간 안정성을 해결하기 위한 방안들이 정리되었다. 특히 이온성 액체를 활용하여 $AgNO_3$를 새로운 운반체로 사용하기 위한 방안, 새로운 고분자 매트릭스로서 poly(ethylene phthalate) (PEP)를 활용하는 방안과 가장 최근 알루미늄 염을 활용하여 운반체의 안정성을 부여하는 연구결과들이 정리되었다. 올레핀 촉진수송을 위한 고분자 나노복합체 분리막의 경우, 운반체인 은 나노입자 표면을 극성화시킬 수 있는 전자수용체의 종류와 특징들이 소개되었으며, 최근 투과도 성능을 향상시킬 수 있는 연구결과들이 정리되었다.

• Journal of Microbiology and Biotechnology
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• 제16권9호
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• pp.1429-1433
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• 2006

Application of recombinant protein production and particularly their isotopic enrichment has stimulated development of a range of novel multidimensional heteronuclear NMR techniques. Peptides in most cases are amenable to assignment and structure determination without the need for isotopic labeling. However, there are many cases where the availability of $^{15}N$ and/or $^{13}C$ labeled peptides is useful to study the structure of peptides with more than 30 residues and the interaction between peptides and membrane. CRAMP (Cathelicidin-Related AntiMicrobial Peptide) was identified from a cDNA clone derived from mouse femoral marrow cells as a member of cathelicidin-derived antimicrobial peptides. CRAMP was successfully expressed as a GST-fused form in E. coli and purified using affinity chromatography and reverse-phase chromatography. The yield of the CRAMP was 1.5 mg/l 1. According to CD spectra, CRAMP adopted ${\alpha}$-helical conformation in membrane-mimetic environments. Isotope labeling of CRAMP is expected to make it possible to study the structure and dynamic properties of CRAMP in various membrane systems.

• 전기화학회지
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• 제10권4호
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• pp.235-238
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• 2007

과산화수소의 발생은 일반적으로 유기 산화제를 포함한 산업적 프로세스의 넓은 분야에 응용된다. 과산화수소는 펄프와 제지 공업의 기계적, 화학적 처리를 위하여 사용되고 염소를 기초로 둔 화학제품에 알칼리 처리로 사용된다. 본 연구에서는 Nafiom과 러시아 양이온 교환막인 MK-40, 제조된 SPEEK막을 가스확산전극이 포함된 과산화수소 발생용 전해 셀에서 비교 실험한다. 다른 양성자 교환막에 효과에 따른 과산화수소 발생의 전기화학적 셀의 전압과 전류 효율, 에너지 소모를 연구한다.

• Membrane and Water Treatment
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• 제5권3호
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• pp.207-219
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• 2014

Fouling is one of the critical factors associated with the application of membrane technology in treating palm oil mill effluent (POME), due to the presence of high concentration of solid organic matter, oil, and grease. In order to overcome this, chemical cleaning is needed to enhance the effectiveness of membranes for filtration. The potential use of sodium hydroxide (NaOH), sodium chloride (NaCl), hydrochloric acid (HCl), ethylenediaminetetraacetic acid (EDTA), and ultrapure water (UPW) as cleaning agents have been investigated in this study. It was found that sodium hydroxide is the most powerful cleaning agent, the optimum conditions that apply are as follows: 3% for the concentration of NaOH, $45^{\circ}C$ for temperature solution, 5 bar operating pressure, and solution pH 11.64. Overall, flux recovery reached 99.5%. SEM images demonstrated that the membrane surface after cleaning demonstrated similar performance to fresh membranes. This is indicative of the fact that NaOH solution is capable of removing almost all of the foulants from PES membranes.

• 멤브레인
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• 제13권2호
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• pp.125-129
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• 2003

은염이 함유된 고분자 전해질을 이용한 올리핀 촉진수송 분리막은 고체상에서 높은 올레핀/파라핀 분리 성능을 나타내었다 본 연구에서는, 프로필렌/프로판 분리 선택도와 투과도의 성능을 향상시키기 위해 아미노산의 일종인 valine을 고분자 전해질막에 첨가하였다. FT-lR 분광학을 통해 valine의 양이온과 은염의 음이온이 상호작용을 하고, 그 결과 valine은 은이온의 활성도를 증가시킴을 알 수 있었다. 따라서 valine을 포함하고 있는 촉진수송 분리막은 valine이 없을 때보다 더 높은 선택도와 투과도를 나타내었다.

• Membrane and Water Treatment
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• 제10권3호
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• pp.239-244
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• 2019

Plating wastewater containing various heavy metals can be produced by several industries. Specifically, we focused on the removal of copper (Cu2+) and nickel (Ni+) ions from the plating wastewater because all these ions are strictly regulated when discharged into watershed in Korea. The application of both nanofiltration (NF) and reverse osmosis (RO) technologies for the treatment of wastewater containing copper and nickel ions to reduce fresh water consumption and environmental degradation was investigated. In this work, the removal of copper (Cu2+) and nickel (Ni+) ions from synthetic water was studied on pilot scale remove by before using two commercial nanofiltration (NF) and reverse osmosis(RO) spiral-wound membrane modules (NE2521-90 and RE2521-FEN by Toray Chemical). The influence of main operating parameters such as feed concentration on the heavy metals rejection and permeate flux of both membranes, was investigated. Synthetic plating wastewater samples containing copper ($Cu^{2+}$) and nickel ($Ni^{2+}$) ions at various concentrations(1, 20, 100, 400 mg/L) were prepared and subjected to treatment by NF and RO in the pilot plant. The results showed that NF, RO process, with 98% and 99% removal for copper and nickel, respectively, could achieve high removal efficiency of the heavy metals.