• Resources Recycling
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• v.4 no.1
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• pp.31-37
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• 1995

This study was to investigate the effects oi agitation speed, pulp concentration, ion concentration ill the slurry solution, printed area of the waste newspaper, immerwng time and the temperature on the defiberation process for the waste newspaper. The defikration efficiency at 50% is twice that of 16%. The efficiency is improved as two times according to elevate the agtation speed as two times in the range of 200-2WO r.p.m.. Defiberation with NaOH 1X10-'M solution has higher efficiency than that of NaOH 1 x 1 0 - M solution as 3 times at the conditions of 16%, 1200 r.p.m, and 1% pulp concentration The temperature of immersing salut~on aifects on the efficiency more than immersing time does. Increasing the printed area of newspaper decreases the velocity of defiberation. The alkaline solution is effective to defiberate and the defiberation efficiency at the same dosage of alkalinity is in the order a1 NaOH) KOH) Na,SiO, ) Na,CO, ) Ca(OH)2.

• Korean Journal of Crystallography
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• v.12 no.2
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• pp.97-101
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• 2001

Phillipsite-type zeolite powders were synthesized from domestic coal fly ash by hydrothermal reaction with 2.0 M-3.5M NaOH solution at $80^{\circ}C{\sim}120^{\circ}C$ for 24 h. The properties of zeolite were investigated by XRD, SEM and IR spectroscopy. The effects of chemical composition of fly ash, reaction temperature and NaOH concentration on the zeolite synthesis were well appeared on IR spectra. It is found that the $TO_4$(T=Si, Al) tetrahedra have a well ordered structure as the $SiO_2$ content, synthesis temperature and NaOH concentration become high.

• Journal of Mushroom
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• v.3 no.2
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• pp.65-70
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• 2005

This study was carried out to select oyster mushroom strains tolerant to salinity and characteristic cultivation by different NaCl concentration. Among the 64 strains, Kimjae-10ho, Nongki-2-1ho, Myungyul, Byungneutari-1ho, Bupyungsoyae-1ho, Sambok and Chunchu-2ho resulted in higher mycelial growth and density on PDA medium containing NaCl. The maxium NaCl concentration possible to fruit body formation was 0.5% NaCl in Myungyul, 1.0% NaCl in Kimjae-10ho and Bupyungsoyae-1ho, 1.5% NaCl in Nongki-2-1ho, Byungneutari-1ho, Sambok and Chunchu-2ho, respectively. Increased NaCl concentration on sawdust medium prolonged culture period, while decreased total quantity and come to be short and thin in Length and thickness of stipe. Higher NaCl concentration in the medium decreased the uptake rate of $K_2O$ and CaO, whereas increased the NaCl uptake rate.

• Journal of Mushroom
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• v.3 no.2
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• pp.79-84
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• 2005

The research for incubation period, mycelial density, day required for primordial formation after inoculation(below DPI), number of valid stipes, individual weight and accumulation amounts of organic selenium for P. cornucopiae by treating 100, 200, 300, 400, 500(${\mu}g/50g$) of $Na_2SeO_3$ is following. Incubation periods of P. cornucopiae are 20~23 days per each low concentration treatment with $Na_2SeO_3$. Compared to the control which took 22 days of incubation period, it is reduced 1 or 2 days. Mycelial density of P. cornucopiae treated with $Na_2SeO_3$ between 100 and $500{\mu}g/50g$ is very compact. DPI of P. cornucopiae treated with $Na_2SeO_3$ between 100 and $400{\mu}g/50g$ was reduced 1 or 2days, but $500{\mu}g/50g$ was increased 1 day. Number of valid stipes of P. cornucopiae treated with $Na_2SeO_3$ between 100 and $400{\mu}g/50g$ is between 19 and 20. It was increased 1 or 2, as compared to 18 of control, but $500{\mu}g/50g$ was reduced to 1. Individual weight of P. cornucopiae treated with $Na_2SeO_3$ between 100 and $400{\mu}g/50g$ was between 129 and 138g/850cc. It was increased 4.9~12.2% as compared to 123g/850cc of the control but $500{\mu}g/50g$ was 122g/50g. Accumulation amount of organic selenium for P. cornucopiae treated with $Na_2SeO_3$ between 100 and $500{\mu}g/50g$ was $2.73{\sim}8.19{\mu}g/g/dry$. It was increased 55~164 times as the concentration increased when compared to $0.05{\mu}g/g/dry$ of the control. In conclusion, incubation period, mycelial density, DPI, number of valid stipes, individual weight and accumulation amounts of organic selenium for P. cornucopiae by treating 100, ${\sim}400{\mu}g$ of $Na_2SeO_3$ was increased, but $500{\mu}g/50g$ was reduced. So more than $500{\mu}g/50g$ concentration treatments are required research.

• Journal of Korea Water Resources Association
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• v.38 no.2
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• pp.133-142
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• 2005

The settling concentration of fine suspended solid particles(alumina(Al$_2$O$_3$) and quartz(SiO$_2$)) is investigated with the physico-chemical effects(initial concentration, pH and NaCl). Laboratory tests have confirmed the significant influence of increasing initial concentration and salinity which can lead to flocculation due to the intermolecular attraction. Furthermore, the influence of the pH value on the concentration-time corves of alumina has been on firmed. Besides a numerical model to predict the behaviour of cohesive deposit under still water is analyzed by solving the unsteady one-dimensional diffusion-advection equation with a explicit, implicit, Crank-Nicolson and finite difference scheme. The model predicts the existence of an equilibrium concentration. Application of the model with implicit centered difference to data from settling experiments shows a similar distribution.

• KSBB Journal
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• v.20 no.4
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• pp.271-277
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• 2005

The polyunsaturated fatty acids (PUFAs) are mostly synthesized by the marine original microorganisms. In this study, the effect of concentrations of glucose, NaCl, and $MgSO_4{\cdot}7H_2O$ on both the growth and the production of lipid and Docosahexaenoic acid (DHA) was investigated using Thraustochytrium aureum ATCC 34304. $Y_{Lipid/X}\;and\;Y_{DHA/Lipid}$ increased according to the increase of initial glucose concentration until 15 g/L of glucose. The maximum values of $Y_{Lipid/X}\;and\;Y_{DHA/Lipid}$ were 0.18 g/g and 0.41 g/g respectively at 15 g/L of glucose. The biomass yield, $Y_{x/s}$, however, was constant as 0.378 g/g regardless of initial glucose concentrations in the range of 5 g/L to 25 g/L. The specific growth rate of T. aureum increased also with initial glucose concentration from 5 g/L and 15 g/L. The maximum value was $0.79\;day^{-1}$ at 15 g/L of glucose, and the growth rate decreased to $0.57\;day^{-1}$ and remained constant according to initial sugar concentration in the range of higher than 15 g/L of glucose. The concentration of NaCl was changed from 0 g/L to 48 g/L, in order to study the characteristics of the growth and the production of lipid and DHA according to NaCl concentration. The growth and the production of lipid as well as DHA stopped all at 0 g/L of NaCl and the maximum values of all the three variables occurred at 24 g/L. The effect of $MgSO_4{\cdot}7H_2O$ concentration was also investigated not to find the growth and the production of lipid and DHA at 0 g/L. However, the growth and the Production with $MgSO_4{\cdot}7H_2O$ concentration increased to reach the maximum values at 18 g/L of $MgSO_4{\cdot}7H_2O$.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.52 no.7
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• pp.293-297
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• 2003

Silicon dioxide (SiO$_2$) layers were fabricated on Si$_3$N$_4$/SiO$_2$/Si layer structures by low pressure chemical vapor deposition (LPCVD). Potassium and aluminum were then coimplanted by implanting potassium ions with the energy of 100 ［keY］ and dose of 5x10$^{16}$ [cm￣$^2$］ and 1x10$^{17}$ [cm￣$^2$］ into an aluminum buffer layer on the SiO$_2$Si$_3$N4/SiO$_2$/Si structure. The pH, pNa, and pK ion sensitivities of the resulting layers were investigated and compared to those of as-deposited silicon dioxide layer. The pK-sensitivity of the silicon dioxide was enhanced by the K and Al coimplantation. On the contrary, the pH and pNa-sensitivities of the coimplanted silicon dioxides were quite lower than that of the as-deposited silicon dioxide.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.12 no.6
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• pp.329-334
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• 2002

The $CaTio_3$powder with perovskite structure was synthesized by mixing anatase $TiO_2$and $Ca(OH)_2$powders as starting materials, and KOH or NaOH as mineralizer, followed by hydrothermal method. The change of crystal structure, particle shape and size of the synthesized $CaTiO_3$powder was investigated with kind and concentration of mineralizer. It was found that the spherical particles of 0.7 $\mu$m were obtained when using 1N KOH and the hexahedrons particles of 3$\mu$m were obtained for the case of using 10 N KOH. With increasing KOH concentration, the particle shape was changed from sphere to hexahedrons and its size also increased. When using 1 N NaOH, the powder was consisted of 0.5~1 $\mu$m particle in size, whereas hexahedrons of 1~4 $\mu$m and whiskers more than 10$\mu$m in size was obtained for the 10 N NaOH solution. With increasing NaOH concentration, the particle shape was varied from hexahedrons to whiskers, showing the similar result with the KOH case. It was confirmed from EDS analysis that Na element, which was detected in hexahedrones was not contained in the whiskers.

• Journal of the Korean Ceramic Society
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• v.31 no.12
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• pp.1521-1528
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• 1994

To improve mechanical strength of bioglass, it is considered to use the glass as a coating material to alumina, but the difference in thermal expansion coefficient between two materials is too high to make a good coating. The aim of the present study, therefore, is to find out proper glass composition matching its thermal expansion coefficient to that of alumina without losing biocompatibility. In the present work, various glasses were prepared by substituting B2O3 and CaO for Na2O in the glass system of 55.1%SiO2-2.6%P2O5-20.1%Na2O-13.3%CaO-8.9%CaF2 (in mole%), and the thermal expansion property and reaction property in tris-buffer solution for the resulting glasses were measured. The thermal expansion coefficient of the glass was decreased with the substitution of B2O3 for Na2O, and it became close to that of alumina in the glass in which 8 mole% of CaO was substituted for Na2O. Hydroxyapatite formation was enhanced and silica rich layer thickness was decreased with B2O3 substitution for Na2O. CaO substitution for Na2O didn't deteriorated the hydroxyapatite development.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.61 no.2
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• pp.113-118
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• 2016

This experiment was conducted to identify the variations in inorganic nutrients and plant growth in millet (Panicum miliaceum L.) due to soil salinity. The soil series was Munpo and soil texture was silt loam. The experimental soil was amended so that the soil had salinities of $0.8dS\;m^{-1}$, $1.6dS\;m^{-1}$, $3.2dS\;m^{-1}$ and $4.8dS\;m^{-1}$. Millet was transplanted 15 days after sowing. As soil salinity increased, the degree of reduced growth was in the order of seed production > root dry matter > plant dry matter > culm length > tiller number > stem thickness > Panicle length. Seed production was decreased to 18.9% in soil salinity of $1.6dS\;m^{-1}$, 36.9% in of $3.2dS\;m^{-1}$, and 50.7% in EC of $4.8dS\;m^{-1}$. Root dry matter decreased to 35.8% in EC of $3.2dS\;m^{-1}$, and to 40.5% in EC of $4.8dS\;m^{-1}$. As soil salinity increased, Total nitrogen content increased in all aboveground parts, roots and seeds. However, There was no difference in CaO, $P_2O_5$, $K_2O$ and, MgO in soils of different salinity. On the other hand, $Na_2O$ content was higher in the order roots> shoots> seed, and in the case of roots, $Na_2O$ content increased to 1.02% in soil salinity of $4.8dS\;m^{-1}$. However, up to soil salinity of $1.6dS\;m^{-1}$, the $Na_2O$ content of the seed was similar to that in plant grown in the Control conditions($0.8dS\;m^{-1}$). In conclusion, taking into consideration economic factors, millet could be cultivated in soil with salinities of up to approximately $1.6dS\;m^{-1}$, and seed produced from reclaimedland would be suitable for human consumption.