• Membrane and Water Treatment
• /
• 제9권1호
• /
• pp.1-7
• /
• 2018

The principal objective of this study is to investigate the effect of Polyethylene Glycol (PEG) crosslinking in Polyvinylidene Fluoride (PVDF) in immobilization of Fe and bimetallic Fe/Cu and Cu/Fe zero valent particles on the membrane and its efficiency on removal of nitrate in wastewater. PVDF/PEG polymer solution of three weight compositions was prepared to manipulate the viscosity of the polymer. PEG crosslinking was indirectly controlled by the viscosity of the polymer solution. In this study, PEG was used as a modifier of PVDF membrane as well as a cross-linker for the immobilization of the zero valent particles. The result demonstrates improvement in immobilization of metallic particles with the increase in crosslinking of PEG. Nitrate removal efficiency increases too.

• 대한화학회지
• /
• 제61권3호
• /
• pp.97-103
• /
• 2017

In this study, the functional hydrogel ophthalmic lens containing tungsten oxide nanoparticles, 2,4-dihydroxy benzophenone and 2-hydroxy-4-(methacryloyloxy) benzophenone were manufactured. HEMA (2-hydroxyethyl methacrylate), MMA (methyl methacrylate), AA(acrylic acid), the cross-linker EGDMA (ethylene glycol dimethacrylate), the initiator AIBN (azobisisobutyronitrile) and the functional additives including tungsten oxide nanoparticles, 2,4-dihydroxy benzophenone, and 2-hydroxy-4-(methacryloyloxy) benzophenone were used respectively. The measurements of water content and refractive index of the sample was decreased and increased, respectively. And also, the UV transmittance of produced lens containing 2,4-dihydroxy benzophenone, 2-hydroxy-4-(methacryloyloxy) benzophenone and tungsten oxide nanoparticles was measured. Based on the results of this study, it is judged that the performance improvement increased over time when 2-hydroxy-4-(methacryloyloxy) benzophenone was used as an additive, while the use of tungsten oxide nanoparticles influenced on blue-ray-blocking effect of the hydrophilic lens.

• 한국생물공학회:학술대회논문집
• /
• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
• /
• pp.701-702
• /
• 2000

대장균에 대한 항체를 수정결정상의 금전극에 고정화하여 압전류적 항체센서 시스템을 제작하고 그 특성을 평가하였다. 그 결과, 정상상태의 센서반응을 얻는데 소요되는 시간이 20분 이내로 단축되었으며 항원 ${\cdot}$ 항체결합에 의한 진동수변화도 대단히 안정적으로 나타났다.

• Journal of Plant Biology
• /
• 제38권3호
• /
• pp.259-266
• /
• 1995

To investigate how the dyad symmetry region (DSR) and the distance between vir box and -35 sequence of the virE promoter plays a role in virE gene expression, two mutants were constructed by base substitution and insertional mutagenesis. The base substitutional mutation, a AAlongrightarrowCG substitution at positions -39 and -40 on the DSR, showed the level of $\beta$-galactosidase activity approximately 91% of the wild type virE promoter activity. Therefore, the native structure of the DSR seems to be not essential for virE expression. The insertional mutation, constructed by inserting 8 bp ClaI linker between -49 and -50, displayed the $\beta$-galactosidase activity at 12% of the native virE promoter activity. However, this striking reduction appears to be not caused by destruction of the native DSR structure, but by shifting the vir box far from putative -35 sequence.

• Fibers and Polymers
• /
• 제7권2호
• /
• pp.95-104
• /
• 2006

In order to improve the water swelling, thermal/mechanical and adhesion properties of waterborne polyurethane (WBPU), a series of the crosslinkable WBPUs containing hydrophilic ionic component, dimethylol propionic acid (20 mole%), were prepared by in-situ polymerization using a cross-linker hexakis (methoxymethyl) melamine (HMMM). Effects of the HMMM content (2, 4, and 6 wt%) and curing temperature on these properties of the crosslinked WBPUs samples were investigated. All properties were found to increase with increasing HMMM content. It was found that the optimum curing temperature of the WBPU films and adhesives was near $120^{\circ}C$, which was not dependent on the HMMM content.

• 대한전기학회논문지:전기물성ㆍ응용부문C
• /
• 제53권11호
• /
• pp.572-576
• /
• 2004

Various devices for diagnosing arrester soundness are suggested, and most of them simply measure magnitude of leakage current. However, such kind of devices do not provide detailed information needed for the diagnosis. In this study, we designed and fabricated a new arrester analyzer by means of measuring the magnitude, the phase vs. wave height and the harmonics of total leakage currents. The analyzer is composed of a current detector, an optical linker, and a main device operated by a microprocessor. The main device is connected with leakage current detector optically not to be influenced by electromagnetic interference. The analyzer developed measures only total leakage currents, but analyzes most parameters needed for the arrester diagnostics.

• 통합자연과학논문집
• /
• 제13권1호
• /
• pp.13-18
• /
• 2020

This study used cerium iron hydroxide nanoparticle with HEMA (2-hydroxyethyl methacrylate), the cross-linker EGDMA (ethylene glycol dimethacrylate), NVP (N-vinyl-2-pyrrolidone) and the initiator AIBN (azobisisobutyronitrile) for copolymerization. Also, the physical properties of the prepared lenses were compared, and their applicability as polymers for ophthalmic materials was experimented. The results of the measurement showed that the UV blocking rate and the wettability increased with the cerium iron hydroxide nanoparticles addition ratio, and the refractive index and water content were not affected. Thus, the produced copolymer is expected to be useful as a functional contact lens material while satisfying the basic physical properties of the hydrogel contact lens.

• Bulletin of the Korean Chemical Society
• /
• 제32권10호
• /
• pp.3575-3580
• /
• 2011

This paper reports a methodology for preparing close-packed two dimensional gold nanoprism films and hexagonal nanoplate films at a hexane/water interface. By controlling the concentration of linker molecules in the hexane layer and the temperature of the colloid solution, highly ordered close-packed nanoplate arrays can be fabricated. These films were investigated to compare their corresponding surface enhanced Raman scattering (SERS) efficiencies. It was demonstrated that the Au nanoprism films resulted in a stronger SERS enhancement than the Au hexagonal nanoplate films. The difference in the SERS enhancement is attributed to the film array difference, demonstrating that Au nanoprism films have a higher line contact density than their Au hexagonal analogues.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2005년도 추계학술대회 논문집
• /
• pp.783-788
• /
• 2005

Detection of small leakage current is the most important technique in arrester diagnosis. Various types of leakage current detector have been commercialized, but they are not available for the railway arresters including voltage harmonics, and do not furnish enough information needed for arrester diagnosis. This paper describes the development of a leakage current detector which is suitable for the railway arresters. The detector is consisted of a sensor unit with amplifier, an optical linker and main analyzer. Frequency bandwidth and measuring range of the detector is 9[Hz]$\~$850[Hz] and 50[uA]$\~$5[mA], respectively.

• Bulletin of the Korean Chemical Society
• /
• 제33권4호
• /
• pp.1285-1289
• /
• 2012

RAP80 plays a key role in DNA damage responses by recognizing K63-linked polyubiquitin moieties through its two ubiquitin-interacting motif (UIM) domains. The linker between the two UIMs possesses a phosphorylation site, but the relationship between phosphorylation and polyubiquitin recognition remains elusive. We investigated the interaction between a phosphorylation-mimic RAP80 mutant S101E and linear polyubiquitins, structurally equivalent to the K63-linked ones, using isothermal titration calorimetry (ITC). ITC analysis revealed differential binding affinities for linear tetraubiquitin by otherwise equivalent UIMs in S101E. Mutational analysis supported such differential polyubiquitin recognition by S101E. Our results suggest a potential crosstalk between polyubiquitin recognition and phosphorylation in RAP80.