• Journal of Animal Science and Technology
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• v.46 no.5
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• pp.841-848
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• 2004

Rapid detection of viable Salmonella in pasteurized milk is important to protect public health from food poisoning. Reverse transcriptase-polymerase chain reaction(RT-PCR) is recognized as a molecular genetical method to differentiate between live and dead bacteria The RT-PCR in this study was designed to detect specifically viable Salmonella in milk by using the primers whose nucleotide sequences were determined based on fimA gene which encodes the submit of type 1 fimbriae. Treatment of RNA preparation with RNase-free DNase was adequate enough to destroy DNA, which may otherwise be amplified in the RT PCR Seven strains of Salmonella were detected in the RT-PCR but Escherichia coli, Shigella sonnei, Citrobacter freundii, and Klebsiella pneumoniae were not. $10^7/ml$ and $10^6/ml$ of dead Salmonella which were heat-treated in milk were detectable by using the RT-PCR but $10^5{\sim}10/ml$ of the dead bacteria were not. The sensitivity of the RT-PCR in detecting viable Salmonella was 100 cells/ml.

• Journal of the Korean Society for Advanced Composite Structures
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• v.1 no.3
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• pp.10-16
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• 2010

In construction industries, new construction materials are needed to overcome some problems associated with the use of conventional construction materials due to the change of environmental and social requirements. Accordingly, the requirements to be satisfied in the design of civil engineering structures are diversified. As a new construction material in the civil engineering industries, fiber reinforced polymeric plastic (FRP) has a superior corrosion resistance, high specific strength/stiffness, etc. Therefore, such properties can be used to mitigate the problems associated with the use of conventional construction materials. Nowadays, new types of bridge piers and marine piles are being studied for new construction. They are usually made of concrete filled fiber reinforced polymeric plastic tubes (CFFT). In this paper, a new type of FRP-concrete composite pile which is composed of reinforced concrete filled FRP tube (RCFFT) is proposed to improve compressive strength as well as flexural strength. The load carrying capacity of proposed RCFFT compression member is discussed based on the result of experimental and analytical investigations.

• Journal of the Korean Society for Advanced Composite Structures
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• v.1 no.2
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• pp.20-28
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• 2010

In this paper, new type CFFT (Concrete Filled FRP Tube) was suggested in order to improve the flexural stiffness. Since the existing CFFT was produced by filament winding process, re-bar for concrete may be necessary in order to ensure structural safety under flexure re-bar. In comparison with existing type CFFT, new type CFFT was reinforced by circular shaped pultrusion FRP without re-bar. Filament winding FRP was attached to the outer layer of pultrusion FRP. Structural behavior of new type CFFT filled with concrete (HCFFT) was investigated by the mechanical property test for the component element and the FE analysis. Furthermore, compressive strength of the HCFFT member based on the equation suggested in previous studies.

• Journal of the Korean Chemical Society
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• v.33 no.5
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• pp.510-515
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• 1989

New nickel(II) and coppr(II) complexes of a saturated pentaaza macrobicyclic ligand $[Ni(D)]^{2+},\;[Cu(D)]^{2+},\;and\;[Cu(D)Cl]^+$, where D is 1,3,6,9,12-pentaazabicyclo[10,2,l]pentadecane, have been prepared by the template condensation reaction of tetraethylenepentamine and formaldehyde in the presence of the metal ion. The complexes contain one imidazolidine ring in the macrobicyclic ligand, D. The complexes $[Ni(D)]^{2+}\;and\;[Cu(D)]^{2+}$ have square planar geometry with 5-5-5-6 chelate ring sequence. The electronic spectra of $[Cu(D)Cl]^+$indicate that the complex has square pyramidal geometry. Synthesis, charactrization, and the spectroscopic and chemical properties of the macrobicyclic nickel(II) and copper(II) complexes are described.

• Korean Chemical Engineering Research
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• v.46 no.4
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• pp.777-782
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• 2008

Using ultrasonic-induced polymerization of pyrrole, mesoporous $TiO_2$ thin film with polypyrrole nanoparticles was prepared. Polypyrrole nanoparticles were ultrasonically synthesized in the mother solution of mesoporous $TiO_2$ before spin-coating. The polypyrrole particles were well dispersed in the solution. After spin-coating and calcinations process, the nanocomposite films have well-organized pore channels without pore-collapse, and polypyrrole nanoparticles are well dispersed in mesoporous $TiO_2$ matrix. The pore size and light absorbance of the mesoporous nanocomposite thin films were controlled by using different template materials, and by using different amount of pyrrole monomer, respectively.

• Clean Technology
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• v.18 no.1
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• pp.38-42
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• 2012

Photonic crystals (PCs) are highly ordered porous materials which have been much attention because of its potential for controlling the light sauces. There are many methods for synthesizing this kind of materials among them we chose the supercritical deposition. With this method the reactants can easily infiltrate into the complex structure. In this paper, supercritical carbon dioxide ($scCO_2$) was used as a reaction medium, which is known as a sustainable solvent due to its nontoxic and noninflammable characteristics. We coated the colloidal template with metal alkoxide by using $scCO_2$ and then obtained macro-porous inverse opals. The reaction was carried out at $40^{\circ}C$ and 80 bar. We synthesized two different inverse opals which called silica and titania inverse opals by use of tetraethyl orthosilicate (TEOS) and titanium isopropoxide (TTIP) as a precursor, respectively.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.33 no.6
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• pp.203-209
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• 2023

Cobalt sulfide nanocomposites were synthesized through a simple hydrothermal method as anode materials for sodium ion batteries (SIBs). In this work, a cobalt sulfide nanoparticle (CoS-NF) and a cobalt sulfide nanocomposite integrated with reduced graphene oxide (CoS@G-NC) were fabricated for electrochemical energy storage performance of battery. The as-prepared CoS@G-NC electrode exhibited reversible and stable cycle performance (62 % after 30 cycles at current density of 200 mA g^-1). The improved electrochemical property was attributed to the small grain growth and uniform distribution of cobalt sulfide during synthesis, which maximized the diffusion pathway for sodium ions and effectively suppressed the delamination and volume expansion of cobalt sulfide during the conversion reaction. The results provide promising anode materials for next-generation SIBs.

• Journal of the Korea Concrete Institute
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• v.14 no.4
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• pp.503-512
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• 2002

Generally, the girder spacing of the two-girder composite bridge is from 5m up to 15m. To ensure the structural safety according to Korean Bridge Design Specification, the deck depth should be from 33 cm upto 73 cm. Using the transversal prestressing strands in concrete deck, we can reduce its depth about 10％. However, there is little experience on the design and construction of prestressed concrete(PSC) decks in Korea. This paper focuses on the behaviors of PSC deck. A literature survey is performed widely. Considering the characteristics of the two-girder bridge and the construction conditions in Korea, a cast-in-place PSC deck is recommended for the two-girder bridge with 6m girder spacing. To examine its structural behaviors and safety, three partial model deck specimens(3 m$\times$5 m) with real scale are fabricated md tested. One(PS34-RS) is 34cm depth with the stiffness restraint in longitudinal edges for simulating the real bridge deck. Another(PS34-NS) is same depth without the stiffness restraint, and the other(PS28-NS) is 28cm depth with the stiffness restraint. Under the static patch loading, each specimen had a larger ultimate flexural strength than the design value. Specimens with the stiffness restraint (PS34-RS and PS28-RS) showed the punching shear failure mode and specimen without that(PS34-NS) showed the flexural failure mode.

• Journal of Life Science
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• v.19 no.3
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• pp.305-310
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• 2009

Plasmid pGKV21 contains a 229-nucleotide (nt) single-strand DNA initiation (ssi) signal. Using asymmetric PCR, we prepared a small single-stranded (ss) DNA fragment of the ssi signal and, using the 229-nt ssDNA fragment, determined the requirements of RNA polymerase for priming and DNA-protein interaction. The ssi fragment prepared was able to generate primer RNAs with almost the same efficiency as the $M13{\Delta}lac182/229$ phage DNA. However, the cssi (complementary strand of the ssi signal) fragment could not synthesize primer RNAs. This result suggests that the 229-nt ssi signal functions in a strand specific manner. Gel retardation and DNase I footprinting demonstrated that the synthesized ssi fragment could interact with both E. coli RNA polymerase and SSB protein to synthesize primer RNA. In Escherichia coli [pWVAp], an addition of rifampicin resulted in an accumulation of ssDNA, indicating that the host-encoded RNA polymerase is involved in the conversion of ssDNA to double-stranded plasmid DNA.

• Korean Journal of Microbiology
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• v.47 no.1
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• pp.30-37
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• 2011

This ultra real-time PCR (UPCR) based diagnosis system for avian influenza A virus (AIV) subtype was designed. The target primer in this study was derived from H5N1 subtype-specific 133 bp partial gene of hemagglutinin (HA), and was synthesized by using PCR-based gene synthesis on the ground of safety. UPCR was operated by Mini-Opticon Q-PCR Quantitative Thermal Cycler using aptamer-based molecular beacon, total 10 ${\mu}l$ of reaction mixture with extraordinarily short time in each steps in PCR. The detection including UPCR and analysis of melting temperature was totally operated within 15 min. The AIV-specific 133 bp PCR product was correctly amplified until 5 molecules of HA gene as minimum of templates. This kind of PCR was drafted as UPCR in this study and it could be used to detect not only AIV subtype, but also other pathogens using UPCR-based diagnosis.