• The Journal of the Korean Society for Microbiology
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• v.20 no.1
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• pp.91-102
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• 1985

The advantages of enzyme-linked immunosorbent assay(ELISA) are its senstivity and simplicity in detecting IgG, IgM and IgA antibody. To apply ELISA to diagnosis of typhoid fever, antigen such as lipopolysaccharide of Salmonella typhi or killed whole cell must be coated on solid phase. It is easy to coat lipopolysaccharide on ELISA plate but troublesome to purify it. As it is easy to obtain the killed whole cells, the development of the appropriate method by which those antigens of S. typhi are optimally coated on solid phase is needed. To establish the appropriate method, carbonate buffer, methanol or poly-L-lysine was applied as binding substance on polystyrene or polyvinylchloride plate as solid phase when the killed whole cell antigens of S. typhi varided as follows: $10^6$, $10^7$, $10^8$ and $10^9\;cell/ml$. The criteria of the optimal method were determined as follows: 1. The optical density of positive sera is above 1.0(0.6 in IgM) at 1:10 serum dilution and is 0.3(0.2 in IgM) higher than that of negative sera: 2. The O.D. of sera is flat or lowering according to serum dilution: 3. It must be that the O.D. of negative sera is lower than 0.2 at the point of serum dilution where the O.D. of positive sera is higher than 1.0(0.5 in IgM). The results obtained were summarized as follows: 1. The methods which fitted the above criteria were to use poly-L-lysine as binding substance, polyvinylchloride plate as solid phase and $10^7\;cell/ml$ as antigen concentration of S. typhi(poly-L-lysine/polyvinylchloride/$10^7$) and poly-L-lysine/polyvinylchloride/$10^8$ in detecting IgG antibody, methanol/polystyrene/$10^9$, poly-L-lysine/polyvinylchloride/$10^8$ and poly-L-lysine/polyvinylchloride/$10^9$ in IgM and carbonate buffer/polystyrene/$10^8$, carbonate buffer/polystyrene/$10^9$, methanol/polystyrene/$10^8$, methanol/polyvinylchloride/$10^8$, methanol/polyvinylchloride/$10^9$, poly-L-lysine/polyvinylchloride/$10^8$ and poly-L-lysine/polyvinylchloride/$10^9$ in IgA. 2. The coaling method using poly-L-lysine, polyvinylchloride plate and $10^8\;cell/ml$ was best to assay IgG, IgM and IgA antibody all in one. By this method, to assay the each immunoglobulin calss with an appropriate fixed serum dilution, 1:320 dilution was best.

• 전기의세계
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• v.26 no.2
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• pp.89-94
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• 1977

In order to investigate the properties of radiation resistance together with dielectric, and mechanical relaxation behaviors of polyvinylcholoride exposed to several different doses under the .gamma.-ray of Co$^{60}$ source, several observations were carried out on the exposed specimens propared by mixing dibutyl-tin-dilaulate and dibutyl-tin-dimaleate as stabilizer with or without adding dioctyl-phthalate as plasticizer. Conclusions obtained from the study are as follows: The origin of the absorption band at 1,540-1,640$cm^{-1}$ / on I.R. spectrum seems to be RCOO- ion originated from ionization of the stabilizer, and this peak can be useful as a measure of radiation resistance on polyvinylchloride. Addition of increasing plasticizer to polyvinylchloride exhibits increasing radiation resistance and the reason for this result may be attributed to aromatic resonance absorption of radiation energy by diotylphthalate. On dose dependent dielectric characteristics, nonplastized specimen shows a peak at about 10 Mrad and that this peak disappears on the plastification of specimens. Those phenomena may be explainable in considering the statistical distribution of scissored chain molecular segments as well as the plastification process of plasticizer to polyvinylchloride chain molecules.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 1997.10a
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• pp.58-58
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• 1997

The corrosion rate of polymer polyethylene terephtalate and polyvinylchloride was characterized at various condition by potentiostate / galvanostate method. The cell and working electrode used for this study was specially preparatain, The potential was scanned at foward scan -2V to 3V and reward scan 3V to -2V, at 50mv/s (R: auto - compensation).

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.2 no.2
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• pp.91-98
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• 1998

In this study, we carried out the experiments for measuring the variations of corrosion potential and current density for polarization curves with polyvinylchloride. The results exhibited especially the influence affecting the corrosion potential and various conditions (temperature, day, pH, bacteria, and added salt). The second anodic current density peak and the minimum passive current density are designated $I_P/I_0,$ respectively. The value of $I_P/I_O$ is used as a measurement for the extent of degradation of the polyvinylchloride. The potentiodpnamics parameters of the corrosion were obtained using Tafel equation.

• Journal of the Korea Safety Management & Science
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• v.11 no.3
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• pp.217-226
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• 2009

The combustion reaction of polyvinylchloride(PVC) was investigated using a thermogravimetric technique under an air atmosphere condition at several heating rates from 10 to $50^{\circ}C$/min. To obtain information on the kinetic parameters, the dynamic thermogravimetric analysis curve and its derivative were analyzed by a variety of analytical methods such as Kissinger, Friedman, Chatterjee-Conrad, Ozawa and Coats-Redfern methods. The combustion reaction of PVC proceeded in two steps; the first step was caused by the dehydrochlorination process in PVC, and the second step by the combustion of polyene. The comparative works for the kinetic results obtained from various methods should be performed to determine the kinetic parameters, because there are tremendous differences in the calculated kinetic parameters depending upon the mathematical method taken in the analysis.

• Elastomers and Composites
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• v.45 no.4
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• pp.250-255
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• 2010

From the three element non-Newtonian model of one non-Newtonian viscoelastic Maxwell elements and a elastic spring, the stress relaxation equation was derived. The various model parameters of this equation were evaluated by appling the experimental results of stress relaxation to the stress relaxation equation. The theoretical curves calculated from this model parameters agreed with the experimental stress relaxation curves. From the parameters of nonlinear viscoelastic model, the hole volume, fine structure, viscoelastic properties and mechanical properties of polymer fibers were studied. The experiments of stress relaxation were carried out using the tensile tester with the solvent chamber. The stress relaxation curves of the two types polyacrylonitrile-polyvinylchloride copolymer and another two types PVC monofilament fibers were obtained in air and water of various temperatures.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.3 no.3
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• pp.159-167
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• 1999

This study performed experiments for measuring corrosion potential and current density variations in the polarzation curves of polyvinylchloride. The results were examined to identify particular influences affectingthe corrosion potential such as temperature, pH, enzyme, and salt. The lines representing active anodic dissolution were only slightly shifted in the potential direction by temperature, pH, enzyme and salt. The Tafel slope for the anodic dissolution was determined using the polarization effect with varying conditions. The slope of the polarization curves describing the active-to-passive transition region was noticeably shifted in the potential direction. In addition, using the variation in conditions, the best temperature and pH were determined for the corrosion rate, and resistance of corrosion. The second anodic current density peak and maximum passive current density were designated as degraded(IP/I0). The value of IP/I0 was used in measuring the extent of the degradation of the polyvinychloride. The potentiodynamic parameters of the corrosion were obtained using a Tafel plot.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.14 no.2
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• pp.53-56
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• 2008

Polyvinylchloride(PVC) is variously used to produce food packaging, wrap film, sealing compound of drinking bottle cap. Safety of these PVC food package is controlled by Food Code, PVC regulation. This study was carried out researches on manufacture process, physical, chemical properties and monomer(CAS No., common name, molecular structure) of PVC to help the understanding of PVC material. Also, this study helps us the understanding of regulation through researches on the foundation of PVC regulation, the purpose of test and the comment of test method. It is considered that these informations of material properties and explanations of test method are very useful to PVC producers, users and analyzers of them.

• Journal of Radiation Protection and Research
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• v.3 no.1
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• pp.23-28
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• 1978

In order to investigate corelation between contents of dioctylphthalate in polyvinylchloride blent dibutyl tin dilaulate with dibutyl tin maleate as stabilizer and the behaviors of radiation resistance as well as electrical conductivity on irradiated specimens, several observations were carried out. A characteristic peak observed in the range of $1,540-1,640cm^{-1}$ on infrared spectra shows such a sensitive response to radiation as the intensity decreases with increasing doses and that this tendency strongly depressed in the presence of plasticizer. It is seemingly attributed for origin of the peak to the existence of RCOO- ion resulting from dissociation of stabilizere, further the depressive effect of decreasing peak intensity influenced by radiation seems to be caused by resonance absorption in benzen ring being a consistituent of plasticizer. It is also suggestive to be use the peak behavior influenced by radiation as a criterion for the evaluation of radiation resistance of PVC. Further the results obtained from electrical conductivity measurement also exhibit reasonable characteristics explainable with views used for the interpretation of the peak behavior mentioned previousely.

• Applied Chemistry for Engineering
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• v.33 no.4
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• pp.367-372
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• 2022

The effect of the addition of a polyvinylchloride (PVC) non-solvent to a PVC-tetrahydrofuran (THF) solution on the surface properties of the PVC thin film was analyzed. The non-solvents used were composed of alcohol-based and non-alcoholic ones. Surface morphologies of PVC thin films according to the addition of the non-solvent were compared. In addition, the hydrophobic properties relying on the surface characteristics were compared. The micro-bubbles generated in the preparation of PVC-THF solution affected the surface morphology of the thin film. In order to implement the normal surface physical properties of the coating thin film at the relatively high concentration of PVC-THF solution, the selection of appropriate drying method was required. When an alcohol-based non-solvent was added, a PVC thin film having a granular porous surface was obtained and exhibited super hydrophobic properties. The volume ratio of the PVC-THF solution to the non-solvent affects the surface shape of the coating thin film. The larger the amount of non-solvent was added, the more advantageous it was to form a super hydrophobic PVC thin film.