• Journal of fish pathology
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• v.12 no.1
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• pp.56-62
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• 1999

Since 1998, mass mortality of the Japanese flounder has widely occurred in the south and west coastal area of Korea. A new serotype birnavirus was isolated during the investigation of the cause of the disease. By the electromicroscopic examination, the isolated virus particles appeared hexagonal and unenveloped with an average diameter 52 to 56 nm. Birnavirus specific fragment was amplified by RT-PCR. High yield of virus (10.3 to 10.8 log $TCID_{50}/ml$) was produced in CHSE-214. RTG-2 and RTE-2 cells. Typical birnavirus CPE was observed in these cells. On the contrary, the virus CPE was not shown in the FHM and EPC cells. By a cross-neutralization test with IPNV Ab, IPNV Sp, IPNV VR-299 and MBV Y6, the isolated virus was closely related to marine birnavirus (MBV).

• Korean Journal of Agricultural Science
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• v.14 no.2
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• pp.401-408
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• 1987

Nine monoclonal antibodies directed against infectious bovine rhinotracheitis virus (IBRV) were prepared by using cell hybridization technique, and the biological properties of the antibodies were investigated by means of immunofluorescence, serum neutralization, and electrophoretic analysis. Eight of 9 monoclonal antibodies reacted specifically with the antigenic constituents of IBRV, infectious laryngotracheitis virus, Marek's disease virus, turkey herpesvirus, hog cholera virus, porcine parvovirus and transmissible gastroenteritis virus. However, the remaining one, 26-2 clone, was found to be cross-reactive with pseudorabies virus. Two monoclonal antibodies, 7-C-2 and 12-A-2, which had neutralizing activity, were reactive with the molecular weights of 72 kilo daltons (72K) and 125K of IBRV proteins electrophoretically separated, respectively. The monoclonal antibody, 3-H-3, which is corresponding to 94K of IBRV proteins, revealed no neutralizing activity. The cross-reactive monoclonal antibody, 26-2, was proved by electrophoretical analysis to be reactive with 100K of IBRV proteins and 40K of pseudorabies virus.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.269-269
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• 2012

A new ion source has been designed, fabricated, and installed at the NBTS (Neutral Beam Test Stand) at the KAERI (Korea Atomic Energy Research Institute) site. The goalis to provide a 100 keV, 2MW deuterium neutral beam injection as an auxiliary heating of KSTAR (Korea Super Tokamak Advanced Research). To cope with power demand, an ion current of 50 A is required considering the beam power loss and neutralization efficiency. The new ion source consists of a magnetic cusp bucket plasma generator and a set of tetrode accelerators with circular copper apertures. The plasma generator for the new ion source has the same design concept as the modified JAEA multi-cusp plasma generator for the KSTAR prototype ion source. The dimensions of the plasma generator are a cross section of $59{\times}25cm^2$ with a 32.5 cm depth. The anode has azimuthal arrays of Nd-Fe permanent magnets (3.4 kG at surface) in the bucket and an electron dump, which makes 9 cusp lines including the electron dump. The discharge properties were investigated preliminarily to enhance the efficiency of the beam extraction. The discharge of the new ion source was mainly controlled by a constant power mode of operation. The discharge of the plasma generator was initiated by the support of primary electrons emitted from the cathode, consisting of 12 tungsten filaments with a hair-pin type (diameter = 2.0 mm). The arc discharge of the new ion source was achieved easily up to an arc power of 80 kW (80 V/1000 A) with hydrogen gas. The 80 kW capacity seems sufficient for the arc power supply to attain the goal of arc efficiency (beam extracted current/discharge input power = 0.8 A/kW). The accelerator of the new ion source consists of four grids: plasma grid (G1), gradient grid (G2), suppressor grid (G3), and ground grid (G4). Each grid has 280 EA circular apertures. The performance tests of the new ion source accelerator were also finished including accelerator conditioning. A hydrogen ion beam was successfully extracted up to 100 keV /60 A. The optimum perveance is defined where the beam divergence is at a minimum was also investigated experimentally. The optimum hydrogen beam perveance is over $2.3{\mu}P$ at 60 keV, and the beam divergence angle is below $1.0^{\circ}$. Thus, the new ion source is expected to be capable of extracting more than a 5 MW deuterium ion beam power at 100 keV. This ion source can deliver ~2 MW of neutral beam power to KSTAR tokamak plasma for the 2012 campaign.

• Korean Chemical Engineering Research
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• v.49 no.5
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• pp.521-529
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• 2011

Methanol-to-olefin (MTO) reaction was studied over MWW zeolite with independently developed two pores (circular and straight) and MFI zeolite with intercrossed sinusoidal and straight pores in order to investigate the effect of pore structure on their catalytic behavior. MWW and MFI zeolites with similar acidity exhibited commonly high conversion and slow deactivation in the MTO reaction, but their product selectivities were considerably different: linear hydrocarbons of $C_3-C_9$ were mainly produced on MWW, while the yield of $C_2{^=}$ and aromatics were high on MFI. Polyaroamatic hydrocarbons (PAHs) were accumulated on MWW, but a small amount of benzene and aromatics on MFI. The impregnation of phosphorous on MWW caused significant decreases in the catalytic activity and toluene adsorption, but the decreases were relatively small on MFI. Although the straight pores of MWW were inactive in the MTO reaction due to the accumulation of PAHs, its circular pores which suppressed the formation of PAHs sustained catalytic activity for the production of linear hydrocarbons. Therefore, the impregnation of phosphorous on the circular pores of MWW caused a significant decrease in catalytic activity. The phosphorous impregnation on the cross sections of MFI altered the product selectivity due to the neutralization of strong acid sites, but catalytic deactivation was negligible. The difference of MWW and MFI zeolites in the MTO reaction was explained by their difference in pore structure.

• Korean Journal of Veterinary Research
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• v.34 no.3
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• pp.517-527
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• 1994

An attempt was made to isolate a causative viral agents from the fecal specimens of the diseased dogs with the gastroenteritis symptoms. Two coronavirus-like agents were isolated by serial dilution end point method and plaque assay. The isolates were characterized in terms of cytopathology, antigenicity, replication, physicochemical and morphological properties. The results obtained through the experiment were as follows; 1. Among 7 fecal specimens collected from the dogs with enteric disease, 2(28.6%)coronavirus-like agents showing typical cytopathic effects of canine coronavirus were isolated, and designated as CCV D1 and CCV D2, respectively. 2. By the cross-neutralization test and indirect immunofluoresence antibody test, the isolates were antigenically indentified as the standard CCV. The viruses were replicated only in the cytoplasm of A-72 cells. 3. The isolates showed no haemagglutinating activity against the erythrocytes from 11 kinds of animals. 4. The electron microscopic observation for the isolates showed spherical and pleomorphic features, covered with club-shaped projections on the surface. The size of particles was ranged from 70 to 150nm. 5. In one-step growth curve for the isolates in A-72 cells, maximum titers of intracellular vius was $10^{4.6}$ $TCID_{50}/0.1ml$ at 46 hrs postinoculation(pi) of CCV Dl and $10^{4.4}$ $TCID_{50}/0.1ml$ at 34 hrs pi of CCV D2. The maximum titers of extracellular virus was $10^{5.5}$ $TCID_{50}/0.1ml$ at 58 hrs pi of CCV D1 and $10^{5.8}$ $TCID_{50}/0.1ml$ at 46 hrs pi of CCV D2. 6. In physicochemical property test, the isolates were very sensitive to choroform and were found to be RNA virus. The viruses was stable at pH 3.0 for 1 hr and at $22{^{\circ}C}$ for 5 hrs. However, infectivity titers reduced remarkably by treatment with $56{^{\circ}C}$ for 10min.

• Journal of Animal Science and Technology
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• v.51 no.5
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• pp.407-412
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• 2009

This study was performed to produce specific egg yolk antibodies against bovine rotavirus (BRV) and bovine coronavirus (BCV) that are major pathogens causing diarrhea in calves. Chickens were immunized with BRV and BCV intramuscularly in the breast muscle by injection 5 times at two weeks interval. At 6 weeks after the first immunization of BRV or BCV, cross reactivity of each serum derived from BRV- or BCV-immunized hens was tested. Each serum antibody against BRV or BCV was reacted with only specific BRV or BCV antigens. Serum and egg yolk-antibody titers of hens against BRV or BCVwere highest at 8~12 weeks after first immunization. Specific serum and egg yolk-antibody titers against BRV were about 104,000 and 107,000, respectively, and those against BCV were about 145,000 and 155,000, respectively. Hemagglutination inhibition titers in the immunized egg yolk antibodies against BRV and BCV were 5,120 and 1,280, respectively, and were ${\geq}8$ times higher than that in non-immunized control. These results suggested that the immunized egg yolk antibodies could effectively neutralize BRV and BCV.

• Journal of Conservation Science
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• v.37 no.5
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• pp.411-425
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• 2021

The Stupa of State Preceptor Jigwang from Beopcheonsa Temple Site in Wonju (National Treasure) is a representative stupa of the Goryeo Dynasty, with outstanding Buddhist carvings and splendid patterns, clearly indicating its honoree and year of construction. However, it was destroyed by bombing during the Korean War (1950-1953) and repaired and restored with cement and reinforcing bars in 1957. The surface condition of the original stone shows long-term deterioration due to the m ortar used in past restorations. In order to identify the exact causes of deterioration, the m ortar and surface contaminants on the original stone were analyzed. Portlandite, calcite, ettringite, and gypsum from the mortar were identified, and its ongoing deterioration was observed through pH measurements and the neutralization reaction test. Analysis of surface contaminants identified calcite and gypsum, both poorly water-soluble substances, and their growth in volume among rock-forming minerals was observed by microscopy. Based on those results, semi-quantitative analysis of Ca and S contents significantly influencing the formation of salt crystals was conducted using P-XRF to analyze the basis of surface deterioration, and cross-validation was performed by comparing the body stone affected by the mortar and the upper stylobate stone unaffected by the mortar. Results indicate that the elements are directly involved in the surface deterioration of the body stone.

• Resources Recycling
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• v.17 no.1
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• pp.80-87
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• 2008

Cementation and solvent extraction processes were studied to separate nickel and iron ions from the $H_2SO_4$ leaching solution with 47 g/L $Fe(Fe^{2+}/Fe^{3+}=1.03),$, 23.5 g/L Ni and 0.90M $H_2SO_4$ which leached from Fe-Ni alloy. Iron powder was used as a reducing agent for the cementation of Ni ion from the leaching solution. The reduction percentage of Ni ion was $17{\sim}20%$ by adding 4 times stoichiometric amount of iron powder at $60{\sim}80$. This may result from the fact that the cementation of Ni ion occurred after the reduction of $Fe^{3+}$ to $Fe^{2+}$ and the neutralization of $H_2SO_4$ with iron powder. The cementation process was proved to be unfeasible for the separation/recovery of Ni ion from the leaching solution including $Fe^{3+}$ as a major component. $Fe^{2+}$ present in the leaching solution was converted to $Fe^{3+}$ for solvent extraction of Fe ion using D2EHPA in kerosene as a extractant. The oxidation of $Fe^{2+}$ to $Fe^{3+}$ was completed by the addition of 1.2 times stoichiometric amount of 35% $H_2SO_4$. 99.6% $Fe^{3+}$ was extracted from the leaching solution (23.5 g/L $Fe^{3+}$) by 4 stages cross-current extraction using 20 vol.% D2EHPA in kerosene. $NiSO_4$ solution with 98.5% purity was recovered from the $H_2SO_4$ leaching solution of scrapped Fe-Ni alloy.

• Cross-Cultural Studies
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• v.45
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• pp.295-324
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• 2016

This essay attempts a contrapuntal reading of Thomas More's Utopia. Contrapunctual reading, proposed by Edward Said. attempts to make a text speak across temporal, cultural, and ideological boundaries to a topic of present. I examine two opposite readings of Utopia around 2011 by both pro- and anti-Occupy Wall Street positions. On the one hand, the opponents of Occupy find its limits as a utopian social movement echoing in the fictional character of Hythrodaeus and the alternative society verbally sketched by him in Book Two of Utopia. On the other, Occupy's advocates read More's text as embodying its radial possibility. However, each shares the tendency to denounce Book Two, praising Book One in which Hythrodaeus vehemently criticizes England; they read Hythrodaeus not as an utopian idealist but as a social critic. The Occupy, as a result, is seen here as having an ambivalent relationship to utopianism. I reinterpret the radical possibilities of Book Two criticized by both pro- and anti-Occupy invocations of Utopia. Book Two provides a utopian space in which the existing social contradictions are cancelled, revealing the limits of the three partial utopias proposed at the end of Book One. Following Louis Marin's argument, I argue, the "utopic" space does not lie in the so-called ideal society described in the text but in the inconsistencies between the text's description(discourse) and topography(map). In Book Two the existence of a king is described, yet his space is not found in the topography of utopia; likewise market is described as existing at the center of a city, yet its space is not found either. These inconsistencies create a neutral space in which the ideological contradictions of the text are cancelled, and the space opens up the possibility of communal society beyond modern sovereign power and capitalism I argue this utopian dream needs to be summoned once again in our time as a compelling alternative to the corporate, capitalist order.

• Korean Journal of Microbiology
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• v.17 no.3
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• pp.97-130
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• 1979

Many industrial processes those employ bacteria are subjected to phage infestations. In L-glutamic acid fermentions using acetic acid, the phage infestations of the organisms have been recently recognized. In efforts to elucidate the sources of phage contamination involved in the abnormal fermentation, a series of study was conducted to isolate the phages both from the contents of abnormally fermented tanks and the soil or sewage samples from the surroundings of a fermentation factory, to define major charateristics of the phage isolates, and finally to determine the correlation between the phage isolates and temperate phages originating from the miscellaneous bacterial species isolated from the soil or sewage samples. The results are summarized as follows; 1) All phages were isolated from the irregular fermentation tanks and soil or sewage samples, and they were designated as phage PR-1, PR-2, PR-3, PR-4, PR-5, PR-6, and PR-7, in the order of isolation. These PR-series phages were proved to be highly specific for the variant strains of Br. lactofermentum only, namely, phage PR-1 and PR-2 for Br. lactofermentum No. 468-5 and phage PR-3~PR-7 for Br. lactofemrentum No. 2256. By cross-neutralization test, the 7 phagescould be subdivided into 3 groups, i. e., phage PR-I and PR-2 the first, phage PR-3, PR-4, PR-5, PR-6 the second, and the phage PR-7 the third. 2) The 7 phages were virulent under the experimental conditions. They produced plaques with clear and relatively sharp margins without distinct halo. The mean sizes of plaques were 1.5mm in diameter for phage PR-1 and PR-2, and 1. Omm for phages PR-3~PR-7. Double layer technique modified by Hongo and described by Adams, was applied to assay of the PR-series phages. The factors influencing the plaques were as follows;young age cells of host bacteria cultured for 3-6 hours represented the largest number and size, optimum was pH 7.0, incubation temperature was $30^{\circ}C$, and agar concentration and amount of overlayer medium were 0.6% and 0.2ml, respectively. 3) PR-series phages were stable in 0.05M tris buffer and 0.1M ammonium acetate buffer solution. The addition of $5{\times}10^{-3}M$ magnesium ion effectively increased the stability. Thermostability experiments indicated that PR-series phages were stable at the teinperture between $50^{\circ}{\sim}55^{\circ}C$ in nutrient medium, $45^{\circ}{\sim}50^{\circ}C$ in buffer solution. However, the phages mere completely inactivated at 603C and 65$^{\circ}$C within 10 minutes. The phages were stable at the range of pH6~9 in nutrient medium and of pH 8-9 in buffer solution, respectively. Exposure of the phages to UV for 25, 60 and 100 seconds resulted in the complete loss of infectivily, respectively. 4) Electron microscopy showed that PR-series phage particles exhibited rather similar morphology, differing in the size All of PR-series phages had a multilateral head and had a simple long tiil about three to five times long as compared with head. By the size, phage PR-1 and PR-2, PR-3, PR-4, PR-5, and PR-6 and PR-7 were classified into same groups, respectively. The head and tail size of phage PR-1, PR-5, PR-5(T) and PR-7 were 85nm, 74nm and 235nm and 350mm, and 72nm and 210nm, respectively. 5) Nucleic acids of PR-series phages were double stranded DNA. The G+C contents of phage PR-1, PR-5 and PR-7 were 56.1, 52.9 and 53.7, respectively. The values of G+C contents derived from the $T_m$ were in agreement with the chemically determined values. 6) PR-series phages effectively adsorbed on their host bacteria at the rate of more than 90% during 5 min. K value for phage PR-1, PR-5 and PR-7 were calculated to be $6{\times}10^9 ml$ per minute, respectiveky. The pH of the medium did effect adsorption rate, but both temperature and age of host cells did not. Generally, optimum adsorption condition of phages seemed to be almost same as optimum growth conditions of host bacteria. 7) In one-step growth experiments, the latent periods at $30^{\circ}C$ for PR-1, and PR-7 were about 70, 50 and 55 min, respectively. The corresponding average burst size was 200, 70 and 90, respectively. Lpsis period according to the multiplicity of infection and a phage series. In case of m. o. i. 100, strain No. 2256 (PR-5) and No. 468-5(PR-1) failed to grow and turbidity decreased after 50 and 70min, respectively. 8) In the lysate of a plaque purified phage PR-5 infected bacteria, there observed 2 types ofphage particles, i. e., phage PR-5 and PR-5 (T) of similar morphology but differing at the length of phage tail, and phage tail like particles. The phage taillike particles could be divided into 4 types by the length. Induction experiments of Br. lactofermentum with UV irradiation, mitomycin C or bacitracin treatment produced neither phage PR-5 (T) or phage tail-like particles. 9) No lysis occured when the growth of 7 strains of miscellaneous bacteria, isolated from soil and sewage samples, were inoculated with either phage PR-5 (T) or phage tail-like particles the inoculation of phage PR-5 pellet resulted in the growth inhibition of the orgainsms in the spot test. The lysates obtained from 3 miscellaneous soil derived bacteria following mitomycin C treatment the growth of Br. lactofermentum, but did not lyze the bacterium.