• Biomedical Science Letters
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• v.11 no.3
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• pp.295-299
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• 2005

Staphylococcus aureus is an important animal and human pathogen implicated in a variety of disease including food-poisoning caused by staphyloccal enterotoxins (SEs). In order to investigate the difference in genomic types and to monitor the transmission of S. aureus isolates, a total of 25 S. aureus isolates from different sources were determined for their genotypic characteristics by pulsed-field gel electrophoresis (PFGE) in addition to their ability to enterotoxin production and antibiotic resistance patterns in this study. All the isolates were susceptible to amikacin, and the resistance pattern to ampicillin and penicillin were most common among 14 different patterns. Eleven of 24 isolates produced one of three SEs, SEA, SEC or SED. Sixteen representative PFGE patterns were obtained by Smal restriction fragments of S. aureus isolates. Analysis of dendrogram based on PFGE band patterns suggested that food-poisoning outbreaks be caused by the diverse sources of food, of which their raw materials were infected with S. aureus. Also, it could be concluded that PFGE was a powerful tool for epidemiological tracing of infection source for food-initiated outbreaks.

• Transactions on Electrical and Electronic Materials
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• v.7 no.2
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• pp.67-71
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• 2006

In this paper, we have investigated the structure and dielectric properties of the $(Ba_{0.6}Sr_{0.4})TiO_3$ (BST) thin films fabricated on MgO(100)/Si substrate by an alkoxide-based sol-gel method. Both the structure and morphology of those films were analyzed by x-ray diffraction (XRD) and atomic force microscope (AFM). For the MgO(100)/Si substrate, the BST thin films exhibited highly (100) orientation. The highly (100)-oriented BST thin films showed high dielectric constant, tunability, and figure of merit (FOM). The dielectric constant, dielectric loss and tunability of the BST thin films annealed at $700^{\circ}C$ deposited on the MgO(100)/Si substrate measured at 10 kHz were 515.9, 0.0082, and 54.3%, respectively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.05b
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• pp.33-36
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• 2005

Colloidal Silica(CS)/silane sol solutions were prepared in variation with synthesizing parameters such as ratio of CS to silane and reaction time. In the case of LHSA CS/tetramethoxysilane(TMOS)/methyltrimethoxysilane(MTMS) CS/silane sol, coating film had stable contact angle with increasing reaction time excepting for 48hours. Also, the LHSA CS/TMOS/MTMS coating film had more enhanced flat surface with increasing the amount of MTMS and increasing reaction time. In the case of thermal stability, thermal dissociation of LHSA CS/MTMS sol did not occur up to $550^{\circ}C$.

• Journal of the Korean Chemical Society
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• v.52 no.4
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• pp.387-393
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• 2008

• Transactions of Materials Processing
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• v.11 no.7
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• pp.569-574
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• 2002

Recently, thick PZT films are required for the cases of micro piezoelectric devices with high driving force, high breakdown voltage and high sensitivity, and so on. In this work, thick PZT films were fabricated by Sol-Gel multi-coating method. Microstructures, and electrical properties of films were investigated by XRD, FESEM, impedance analyzer, and P-E hysteresis. PZT films with 2.7$mu extrm{m}$ to 4.4${\mu}{\textrm}{m}$ thickness were fabricated. Dielectric constant, loss, remnant polarization and coercive field of them were 880~1650 at 1kHz, 2~3% at 1kHz, 26~32 $\mu$C/$ extrm{cm}^2$, and 33~60kV/cm, respectively. Also a transverse piezoelectric coefficient $(e_{31,f})$ measurement system was fabricated and tested for thick film samples.

• Proceedings of the KIEE Conference
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• 1994.07b
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• pp.1472-1474
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• 1994

In this paper, $TiO_2-V_2O_5$ thin films are fabricated by Sol-Gel method and their humidity-sensing characteristics have been investigated. The microstructure of specimen is porous. The humidity-sensing characteristics of thin films are good according to increasing heat treatment temperature and decreasing measurement frequency.

• Journal of the Korean Ceramic Society
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• v.23 no.4
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• pp.78-84
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• 1986

Zirconium acetate solution which was obtained from $ZrOCl_2$.$8H_2O$ was condensed polymerized and drawn to fibers by pulling method. Drawn gel fibers fired at 130$0^{\circ}C$ were short porous and mechanically weak. But addition of CaO about 13m/o caused the fibers to have the cubic structure and relatively dense microstructure. In order to clarify the condition for the synthesis of zirconia fibers viscosity measurement DTA-TG analysis X-ray diffraction infrared spectroscopy, SEM and specific surface area were studied.

• Proceedings of the Korea Association of Crystal Growth Conference
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• 1998.09a
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• pp.103-111
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• 1998

Au fine particle dispersed TiO2 film was prepared on silica glass substrate by sol-gel dip and firing process. The films were fabricated from the system of titanium tetraisoproxie-EtOh-HCl_H2O-hydrogen tetrachloroaurate(III) tetrahydrate. The conditions for the formation of the clear solution and dissolving high concentration of Au compound were examined. And a photoreduction process was adopted to control the size of gold metal particles. Phase evolution of matrix TiO2 and variation of Au particle with UV irradiation were investigated by XRDA, SEM, TEM and UV-visible spectrophotometer. And the effect of CPCl(Cetylpyridinium chloride monohydrate) as a dispersion agent was evaluated.

• Bulletin of the Korean Chemical Society
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• v.33 no.6
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• pp.1856-1860
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• 2012

$SnO_2/SiO_2$ nanocomposite has been synthesized by using sol-gel method. Prepared catalytic materials has been well characterized by using X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FT-IR), Brunauer-Emmer-Teller (BET) surface area, and temperature-programmed desorption of ammonia ($NH_3$-TPD). $SnO_2/SiO_2$ nanocomposite catalyzed synthesis of 2-arylbenzothiazoles by the cyclocondensation of 2-aminothiophenol and aromatic aldehydes under reflux condition in 1:1 EtOH:$H_2O$. After completion of the reaction, catalyst can be recovered efficiently and reused with consistent activity.

• Transactions on Electrical and Electronic Materials
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• v.6 no.2
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• pp.35-38
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• 2005

Pb(Zr$_{0.8}$Ti$_{0.2}$)O$_{3}$ powders, prepared by the sol-gel method, were mixed with an organic vehicle and the PZT thick films were fabricated by the screen-printing techniques on Pt/Ah03 substrates. The structural properties were examined as a function of sintering temperature. The particle size distribution of the PZT powder derived from the sol-gel process is uniform with the mean particle size of about 2.6 m. As a result of the DTA, the formation of the polycrystalline perovskite phase was observed at around $890^{circ}$CC. In the X-ray diffraction analysis, all PZT thick films showed a perovskite polycrystalline structure without a pyrochlore phase. The perovskite crystallization temperature of PZT thick films was about $890^{circ}$C. The average thickness of the PZT thick films was approximately 80-90 m.