• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.99-104
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• 2002

In this paper the influence or specimen length on flexural compressive strength and parameter or equivalent rectangular stress block of polymer concrete was evaluated. For this purpose, a series of C-shaped specimens subjected to eccentric compression were tested using four different length-to-depth ratios(from 1.0, 2.0, 3.0 and 4.0) of specimens with compressive strength of 1,020kgf/cm$^2$. Results indicate that for the region of h/c$\leq$3.0 the reduction in equivalent rectangular stress block depth and flexural compressive strength with increase of length-to-depth ratios was apparent but for the region of h/c$\geq$3.0 they were nearly constant. It means that for the region of h/c$\geq$3.0 effect of specimen length on equivalent rectangular stress block depth and flexural compressive strength was negligible. It was also founded that the effect of specimen length on v, a coefficient of strength, that was from 0.84 to 0.86 regardless of h/c was petty. Finally, predictive equation is, suggested by using modified law of effect of specimen length and results.

• Journal of Korean Ophthalmic Optics Society
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• v.8 no.2
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• pp.91-97
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• 2003

The behaviors of diamond deposition using microwave plasma chemical vapor deposition method have been studied by varying the concentration of methane in the methane - hydrogen gas mixture. The carbonization is checked from peak intensities of D($sp^3$) and G($sp^2$) peaks in Raman spectra. The hydronization and C-H bonding status in films can also be determined from FTIR results. Both the bonding strength of C-H and the ratio of $sp^3$ to $sp^2$ in bonding are found to be slightly dependent of partial pressure of $CH_4$ Judging from above results, we can conclude that the best value for partial pressure of $CH_4$ in growing process of thick films is about 13.8%.

• Journal of Life Science
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• v.8 no.2
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• pp.145-157
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• 1998

We isolated 100 Vobrio sp. from marine products and sea from July to September, 1997. We attemped on purification of hemolysin produced by Vibrio sp. The growth, hemolysin production patterns by the 100 strains of Vibrio sp. showed identical, in general. V. unlnificus ys-1 produced hemolysis as the higtest titer. The optimal culture conditions for the hemolysin production by the V. vunificus ys-1 are followings; 1. Hemolysin production was optimal dering the late exponetial phage. 2. Maximal growth, hemolysin production were in heart infusion broth. 3. Maximal yields of hemolysin was obtained when the heart infusion broth had an intial pH of 8.0, 3$0^{\circ}C$, 3% NaCL. Hemolysin was purified from culture filtrate of the strain by ammonium sulfate recipitation, ion exchange and hydrophobic interaction chromatography. The results were as follows; 1. Hemogeneity of the purified hemolysin was demonstrated by revealing single band on SDS-PAGE. The molecular weight of purified hemolysin was 45KDa. 2. The absorbance rattern in ultraviolet wsa typical of those seen with most proteinb with 280nm. 3. Purified hemolysin was atable at 5$0^{\circ}C$ but 7$0^{\circ}C$ of the acivity was lost by heating for 30 min at 6$0^{\circ}C$/ Optimal temperature of purified hemolysin was 35$^{\circ}C$. 4. Purified hemolysin was stable at the pH range of 6~9, but in the less the pH5.0. above the pH 9.0, the hemolysin activity was lost completely.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.18 no.4
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• pp.439-455
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• 2020

Numerical model was developed that simulates radionuclide (3H and 14C) transport modeling at the 2nd phase facility at the Wolsong LILW Disposal Center. Four scenarios were simulated with different assumptions about the integrity of the components of the barrier system. For the design case, the multi-barrier system was shown to be effective in diverting infiltration water around the vaults containing radioactive waste. Nevertheless, the volatile radionuclide 14C migrates outside the containment system and through the unsaturated zone, driven by gas diffusion. 3H is largely contained within the vaults where it decays, with small amounts being flushed out in the liquid state. Various scenarios were examined in which the integrity of the cover barrier system or that of the concrete were compromised. In the absence of any engineered barriers, 3H is washed out to the water table within the first 20 years. The release of 14C by gas diffusion is suppressed if percolation fluxes through the facility are high after a cover failure. However, the high fluxes lead to advective transport of 14C dissolved in the liquid state. The concrete container is an effective barrier, with approximately the same effectiveness as the cover.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.05a
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• pp.118-122
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• 1996

1wt% Pt/MoO$_3$ gas sensors for detecting H$_2$ gas were fabricated by the pressed pellet method and surface structures of Pt/MoO$_2$ were investigated by TEM and XRD. It was observed that as the calcination temperature is increased, the overlayers of MoO$_3$ on Pt are produced, but the Cl content in PtCl$\_$x/ are decreased. H$_2$ gas sensing properties in N$_2$ ambient and in air ambient were investigated, respectively, and Pt/MoO$_3$ had high sensitivity at low working temp ; 7.8% at 50$^{\circ}C$, 97.7% at 100$^{\circ}C$, 97.1% at 150$^{\circ}C$ when the specimens are treated at 400$^{\circ}C$, and 99.6% at 150$^{\circ}C$ when they are treated at 200$^{\circ}C$. It shows the development of a low-power type sensor is possible by using Pt/MoO$_3$.

• Journal of the Korean Society for Heat Treatment
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• v.7 no.2
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• pp.129-138
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• 1994

The purpose of this study is to clarify the influence of the reaction temperature and $AlCl_3$ content on the aluminide coating formation on Ni-based superalloy IN713C in CVD process and to compare its throwing power with that of Pack Cementation process. Aluminide coating was formed by CVD in hot-wall stainless tube reactor from an $AlCl_3-H_2$ mixture in the temperature range $850{\sim}1050^{\circ}C$. At reaction temperature $850^{\circ}C$, the coating thickness and the content of aluminium at the surface were increased as $AlCl_3$ heating temperature was raised. At reaction temperature $1050^{\circ}C$, they were not influenced by the variation of $AlCl_3$ heating temperature. When $AlCl_3$ heating temperature was fixed $125^{\circ}C$, the phases of the coatings were varied from $Ni_2Al_3$ to Al-rich NiAl and to Ni-rich NiAl with the reaction temperature. Therefore, in this study the reaction temperature has been found to be a major factor in determining the phase formed in CVD process. The throwing power of CVD was superior to that of Pack Cementation.

• Journal of Animal Environmental Science
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• v.11 no.2
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• pp.103-110
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• 2005

The study was carried out to develop the real time measuring technique of ammonia and carbon dioxide concentration emitted from growing-finishing pig house in winter and estimate ammonia emission rate emitted from the pig house. As the study was carried out, environmental management technique for the pig house and odor abatement skill could be properly developed to reduce the residence's annoyance. The room temperature of the growing-finishing pig house was $10^{\circ}C$ higher than outdoor air temperature in spite of additional heating, because of heat emitted from body temperature of the pigs. The daily variation pattern of room temperature in the pig house shows the similar tendency with outdoor air temperature. The daily mean ventilation rate per head was $16\;m^3/h$ and ranged from $12\;m^3/h$ to $22.4\;m^3/h$. The difference of day and night for ventilation rate was about 2 times. The ammonia emission rate was $208{\pm}28\;mg/h{\cdot}pig$ per daily basics calculated with ventilation rate and ammonia concentration.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.3
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• pp.286-291
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• 2006

We studied possibility of mixing treatment of livestock wastewater and sewage using Phanerochaete chrysosporium PSBL-1. Our study showed that 97.6% of SS and 95% of T-P removal efficiency was achieved when 2 mL BF02(a coagulant) and 100 mL C-210EL(a cationic polymer) were added to the mixture(2:1, v/v) of livestock wastewater and sewage. We studied treatment characteristic of Phanerochaete chrysosporium PSBL-1, after were mixed pretreated wastewater and sewage by dillution ten times about livestock wastewater. The removal efficiency of NBDCOD(non-biodegradable COD), $NH_3-N$ and T-N was increased according to increase of pH. That is, T-N concentration of effluent was satisfied 60 mg/L by drain water waterqulity standard of livestock wastewater public treatment facilities with 35 mg/L from a lapse of five days at pH 6.7, 51 mg/L from a lapse of three days at pH 8 and 33 mg/L from a lapse of one day at pH 10. Moreover $COD_{Mn}$ concentration of effluent was satisfied 40 mg/L by drain water waterqulity standard of livestock wastewater public treatment facilities after a laps of one day at all pH. Organics and nitrogen concentrations of effluent were higher case with addition of V.A.(veratryl alcohol) than case without addition of V.A.(veratryl alcohol). $COD_{Mn}$ concentration of effluent satisfied drain water qulity standard of livestock wastewater public treatment facilities from a lapse of one day, when C/N rate(3:1) of influent was not controled. T-N satisfied that from a lapse of two days, when C/N rate was controled with $4{\sim}6$.

• Korean Journal of Microbiology
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• v.40 no.3
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• pp.217-220
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• 2004

The effect of media composition and culture condition on mycelial growth and cordycepin (3'-deoxyadenosine) production was determined using Cordyceps spp. Among the strains of C. militaris and C. sinensis tested, C. militaris KCTC 6862, C. militaris DGUM 32003 and C. militaris KCTC 16932 were excellent for the production of cordycepin. The optimal temperature and pH for production of cordycepin were $24^{\circ}C$ and pH ranged from 6.0 to 10, respectively. Among various sources of carbon and nitrogen tested, glucose and tryptone were very excellent for the production of cordycepin, respectively. After 5days cultivation with 1% of tryptone with nitrogen source, 39mg/l of cordycepin was produced. However, addition of phosphorus sources reduced the production of cordycepin.

• Korean Journal of Environmental Agriculture
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• v.30 no.2
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• pp.189-195
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• 2011

BACKGROUND: Wastewaters were collected from 25 sites of two industrial areas of Mymensingh and Gazipur in Bangladesh to assess metallic toxicity of wastewater for irrigation usage. METHODS AND RESULTS: The analyzed wastewaters were slightly alkaline to alkaline in nature and were problematic for irrigation except 3 samples. As per TDS values, 9 samples were rated as fresh water and the rest 16 were classified as brackish water. EC and SAR reflected that all samples were medium salinity (C2), high salinity (C3), very high salinity (C4) and low alkalinity (S1) hazard classes expressed as C2S1, C3S1 and C4S1. Wastewaters of different industries were graded as excellent, good, permissible and doubtful for irrigation purpose as per SSP. According to hardness ($H_T$), wastewater were under moderately hard, hard and very hard classes. Cd, Cr and Cu ions were treated as toxicant for irrigating soils and crops. Zn was problematic for long-term irrigation. The concentrations of Pb, Fe and Na were far below the toxic levels. Synergistic relationships were observed between pH-EC, pH-TDS, EC-TDS, SAR-SSP and SSP-hardness. CONCLUSION(s): If wastewater is applied for irrigation due to the fresh water shortage, it can contaminate soil due to some toxic metal ions.