• Journal of Adhesion and Interface
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• v.7 no.3
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• pp.10-15
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• 2006

After anchoring 3-(2-aminoethylamino)propyltriethoxysilane (APTES) onto the surfaces of the channels within ordered mesoporous silica, SBA-15, we dispersed $Cu^{2+}$-perfluorophthalocyanine into the modified SBA-15 channels. From small-angle X-ray scattering (SAXS) patterns and transmission electron microscopy (TEM) images, we confirmed that both the calcined and $Cu^{2+}$-perfluorophthalocyanine-incorporated SBA-15 samples possessed ordered periodic structures and hexagonal symmetry lattices (p6mm). The value of the $d_{100}$ spacing was decreased after the incorporation of $Cu^{2+}$-perfluorophthalocyanine into the modified SBA-15 channels. We used FTIR and UV-Vis spectroscopy and thermogravimetric analysis (TGA) to characterize both the modified SBA-15 and the $Cu^{2+}$-perfluorophthalocyanine-incorporated SBA-15 samples. From scanning electron microscopy (SEM) images and $N_2$ sorption measurements, we found that the $Cu^{2+}$-perfluorophthalocyanine units were incorporated within the modified SBA-15 channels, rather than on the external surfaces of the modified SBA-15 channels.

• Journal of Electrochemical Science and Technology
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• v.2 no.2
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• pp.124-129
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• 2011

A simple process of fabricating micropillar structure and its influence upon enhancing electrochemical biosensor response were studied in this work. Conducting polymer PEDOT was used as a base material in formulating a composite with PVA. Micro porous PC membrane filter was used as a template for the micropillar of the composite on ITO electrode. This structure could provide plenty of encapsulating space for enzyme species. After dosing enzyme solution into this space, Nafion film tent was cast over the pillar structure to complete the micropillar cavity structure. In this way, the encapsulation of enzyme could be accomplished without any chemical modification. The amount of enzyme species was easily controllable by varying the concentration of the dosing solution. The more amount of enzyme is stored in the sensor, the higher the electrochemical response is produced. One more reason for the sensitivity improvement comes from the large surface area of the micropillar structure. Application of 0.7 V produced the best current response under the condition of pH 7.4. This biosensor showed linear response to the glucose in 0.1~1 mM range with the average sensitivity of $14.06{\mu}A/mMcm^2$. Detection limit was 0.01 mM based on S/N = 3.

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.385-385
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• 2009

Uniform polyaniline nanofibers (PANI NFs), and chemically doped sulfamic acid(SFA) PANI NFs, synthesized via template free interfacial polymerization process, were used as new counter electrodes materials for the fabrication of the highly-efficient dyesensitized solar cells (DSSCs). The PANI NFs based fabricated DSSCs exhibited a solarto-electricity conversion efficiency of ~ 4.02% while, the SFA doped PANI NFs based DSSC demonstrated ~ 27% improvement in the solar-to-electricity conversion efficiency. The obtained solar-to-electricity conversion efficiency for SFA doped PANI NFs based DSSC was 5.47% under 100mW/$cm^2$(AM1.5). The enhancement in the conversion efficiency was due to the incorporation of SFA into the PANI NFs which resulted to the higher electrocatalytic activity for the $I^{3-}/I^-$ redox reaction.

• Journal of Microbiology and Biotechnology
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• v.15 no.2
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• pp.403-411
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• 2005

The relationship between plasmid (~9.5 kb) and pediocin PA-1 in P. acidilactici K10 was confirmed by plasmid curing. The pediocin operon of P. acidilactici K10 was amplified by PCR (polymerase chain reaction), and the nucleotide sequence was analyzed. The sequence of the pediocin operon of P. acidilactici K10 was similar to those of P. acidilactici strains producing pediocin PA-1/ AcH. For the expression of pediocin PA-1 in E. coli, a pQEPED (pQE-30 Xa::mature pedA) was constructed. His-tagged recombinant pediocin PA-1 (-6.5 kDa) was translated by cell-free in vitro transcription and translation using pQEPED as a DNA template. Theresult of slot blotting assay showed that transcription of recombinant pedA in E. coli M15 was induced by the addition of isopropyl-$\beta$-D-thiogalactopyranoside (IPTG) at the final concentration of 1 mM. Although the recombinant pediocin PA-1 inhibited the growth of E. coli, it was expressed in the host strain and purified by nickel-nitrilotriacetic acid (Ni-NTA) metal-affinity chromatography under denaturing condition. This is the first report for the production and one-step purification of biologically active recombinant pediocin PA-1 in E. coli.

• Bulletin of the Korean Chemical Society
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• v.35 no.4
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• pp.1110-1116
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• 2014

The cuprous oxide cubes with the special porous surface constructed by nano-prisms have been successfully fabricated by a solvothermal method. The template-free method is simple and facile without any surfactant. The X-ray powder diffraction (XRD) pattern suggests that the as-prepared product is the pure primitive cubic $Cu_2O$. The effects of the experimental parameters, such as the reaction temperature, reaction time and the concentration of sodium acetate anhydrous, on the morphologies of the products were investigated in detail by the scanning electron microscopy (SEM). Based on the time-dependent experiments, the possible formation mechanism was proposed. Using photocatalytic degrading reactive dyes as the model reaction and xenon lamp to simulate sunlight, the $Cu_2O$ cubes with the porous surface might possess higher photocatalytic activity than those of the commercial $Cu_2O$ powder in the visible-light region, indicating the excellent photocatalytic performance.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.27 no.6
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• pp.575-580
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• 2005

Transitional implants were developed to support provisional restorations and to allow for load-free osseointegration of conventional implants while a patient was provided with immediate esthetics and function and are usually placed simultaneously at the time of definitive implant placement. Transitional implants are placed in a non-submerged fashion in a single-stage surgery and are designed to be immediately loaded. They generally are made of commercially pure titanium or titanium alloy and are designed as 1-piece implants composed of root and crown replacement segments. Transitional implants can be used in a wide range of indications, such as basic use as temporary implant, to support and protect the primary implants during the healing phase, single crown in the edentulous anterior region of mandibular, anchorage for orthodontic treatment, support a surgical and radiographic template, and primary implant to extremely atrophied alveolar crests of the mandible and maxilla. This article describes the clinical use of transitional implants to support the provisional complete denture and single crown in the restricted edenturous central incisor region of mandible.

• Advances in nano research
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• v.3 no.2
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• pp.111-121
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• 2015

$CoFe_2O_4$ nanotubes and porous nanorods were prepared via a simple one-pot template-free hydrothermal method and were used as an adsorbent for the removal of dye contaminants from water. The properties of the synthesized nanotubes and porous nanorods were characterized by electron diffraction, transmission electron microscopy and x-ray powder diffraction. The Adsorption characteristics of the $CoFe_2O_4$ were examined using polar red dye and the factors affecting adsorption, such as, initial dye concentration, pH and contact time were evaluated. The overall trend followed an increase of the sorption capacity reaching a maximum of 95% dye removal at low pHs of 2-4. An enhancement in the removal efficiency was also noticed upon increasing the contact time between dye molecules and $CoFe_2O_4$ nanoparticles. The final results indicated that the $CoFe_2O_4$ nanotubes and porous nanorods can be considered as an efficient low cost and recyclable adsorbent for dye removal with efficiency 94% for Cobalt ferrite nanotubes and for Cobalt ferrite porous nanorods equals 95%.

• Carbon letters
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• v.18
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• pp.30-36
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• 2016

Well-dispersed Ag₃VO₄ nanoparticles @polyacrylonitrile (PAN) nanofibers were synthesized by an easily controlled, template-free method as a photo-catalyst for the degradation of methylene blue. Their structural, optical, and photocatalytic properties have been studied by X-ray diffraction, transmission electron microscopy, field-emission scanning electron microscopy equipped with rapid energy dispersive analysis of X-ray, photoluminescence, and ultraviolet-visible spectroscopy. The characterization procedures revealed that the obtained material is PAN nanofibers decorated by Ag₃VO₄ nanoparticles. Photocatalytic degradation of methylene blue investigated in an aqueous solution under irradiation showed 99% degradation of the dye within 75 min. Finally, the antibacterial performance of Ag₃VO₄ nanoparticles @PAN composite nanofibers was experimentally verified by the destruction of Escherichia coli. These results suggest that the developed inexpensive and functional nanomaterials can serve as a non-precious catalyst for environmental applications.

• Restorative Dentistry and Endodontics
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• v.26 no.6
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• pp.492-498
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• 2001

The purpose of this study was to evaluate four different composite resins in vitro for microleakage in Class II box type restorations that have gingival margins apical to the cementoenamel junction. Forty caries free extracted human molars were used in this study. The Class II cavities were prepared 1.0mm below cementoenamel junction with a #701 carbide bur. The teeth were randomly divided into four groups, each group comprising 20 treated cavities according to adhesives and filling materials ; Group 1: Scotchbond Multipurpose/Z 100. Group 2: Ariston Liner/Ariston pHc, Group 3: One Step/Pyramid, Group 4: Prime & Bond NT/SureFil. To simulate the clinical situation during restoration placement, a restoration template was fabricated and composite resin was filled using a three sited light-curing incremental technique. The specimens were stored in the 100% humidity for 7 days prior to thermocycling. The specimens were immersed in 2% methylene blue dye solution for 24 hours and then embeded in transparent acrylic resin and sectioned mesiodistally with a diamond wheel saw. The degree of marginal leakage was scored under the stereomicroscope($\times$20) and the data were analyzed by Kruskal Wallis test and Mann Whitney test. (omitted)

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.172-172
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• 2010

In the area of optoelectronic devices based on GaN and related ternary compounds, the two-dimensional system like as quantum wells (QWs) has been investigated as an effective structure for improving the light-emitting efficiency. Generally, the quantum well active regions in III-nitride light-emitting diodes grown on conventional c-plane sapphire substrates have critical problems given by the quantum confined Stark effect (QCSE) due to the effects of strong piezoelectric and spontaneous polarizations. However, the QWs grown on nonpolar templates are free from the QCSE since the polar-axis lies within the growth plane of the template. Also the unique characteristic of linear polarized light emission from nonpolar QW structures is attracting attentions because it is proper to the application of back-light units of liquid crystal display. In this study, we characterized optical properties of the a-plane InGaN/GaN QW structures by temperature-dependent photoluminescence (TDPL) measurements. From the photoluminescence (PL) spectrum measured at 300 K, green emission centered at 520 nm was observed for the QW region. Since indium incorporation on nonpolar QWs is lower than that on c-plane, this high indium-doping on a-plane InGaN QWs is not common. Therefore, the effect of high indium composition on optical properties in a-plane InGaN QWs will be extensively studied.