• Journal of the Korean Institute of Telematics and Electronics
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• v.18 no.4
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• pp.49-61
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• 1981

A generally applicable computer simulation program for diffused silicon solar cells has been developed on the basis of the experimental results. The program can be easily used to obtain the spectral response and I-V characteristics for N+P, P+N N+PP+, P+NN+cells by changing various input parameters. The insolated spectra can be taken from AMI and constant intensity and GE - ELH lamp light sources. The options for AR coating are Si3N4 film and materials with constant reflectance including zero reflectance for ideal case. The computer simulation demonstrates successful results compared with the measured values for the short circuit current, open circuit voltage, efficiency, spectral response, quantum efficiency, I-V characteristics, etc. This program was used to optimize doping concentration, cell thickness, light concentration, junction depth, and to obtain the limit values for front surface recornbination velocity, effective carrier life time in the depletion regions and shunt resistance, and also to drive the changing rate in conversion efficiency depending on operation temperature, series resistance and electric field strength in N+P+ bulk regions.

• Journal of Sericultural and Entomological Science
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• v.27 no.2
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• pp.40-46
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• 1985

The equilibrium sorptions of C.I. Reactive Blue 19 and C.I. Reactive Blue 19 and C.I. Acid Blue 138 on Silk fibroin were investigated in the range of 50$^{\circ}C$, 70$^{\circ}C$, 90$^{\circ}C$ and to the pH range from 2.0 to 10.5. The results obtained are summarized as follows: 1) The amount of sorption of reactive dye was increased with the decrease of pH in dyeing solution and temperature. The amount of fixation showed the maximum value to pH 8.5 and 70$^{\circ}C$. 2) In acidic region, the sorption behavior of acid dye was similar to that of reactive dye, and Langmuir adsorption constant was increased with the decrease of pH. 3) Langmuir constant of both dyes was decreased with the increase of temperature, while standard affinity was increased. 4) The reaction of both dyes was exothermic and the values of $\Delta$S$^{\circ}$ were positive. 5) It was found that the sorption behavior of dyes against Silk fibroin could be described as Langmuir adsorption and Nernst distribution in lower pH region.

• Journal of the Mineralogical Society of Korea
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• v.9 no.1
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• pp.1-6
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• 1996

Woolastonite from Susan occurs as intercalations in limestone beds of Lower Paleozoic Joseon Supergroup. It is a thermal metamorphic product of impure limestone. Electron microprobe analysis shows that it is considerably pure wollastonite. It has triclinic cell with a=7.932$\AA$, b=7.328$\AA$, c=7.069$\AA$, $\alpha$=89.995$^{\circ}$, $\beta$=$95.255^{\circ}$, and $ \Upsilon=103.367^{\circ}$.Dissolution behaviors of wollastonite have been studied conducting three different dissolution experiments; two different reactions with HC1 (one batch and one re-initialization experiment) and one traction with distilled water. In the batch type powder wollastonite-HCl reaction, pH of solution rapidly increases in the early stage and then its rate of increase slows down to reach plateau resulting in parabolic relationship with time. It is represented by the early rapid rise and fall in pH giving a sharp pH-edge and succeeding slow rise in the re-initialization experiment. The early rapid rise in pH is due to the rapid sorption of H- in solution to oxygens on the reactive surface of wollastonite and the fall in pH means that all reactive surface sites are occupied by H- ions and no more H- adsorption occurs. The slow rise in pH following the pH- edge is due to the dissolution of wollastonite as evidenced by the correlation of pH variation and cation concentration. Dissolution of powder wollastonite in HCl shows linear trend with time. Si is dissolved predominantly over Ca at a constant rate. Ca is dissolved predominantly in the very early stage. Dissolution rate of coarse-grained wollastonite fragments in distilled water is parabolic with times howing a rapid reaction in the early stage and a slow reaction in the advanced stage. The Ca/Si ratio in solution is high in the case of coarse-grained wollastonite fragment as compared with powder wollastonite. The coarse-grained wollastonite fragment-water (acid) reaction resulted in the solution with an elevated constant pH value (alkaline) giving an important significance on the environmental view point.

• Journal of Korean Society of Water and Wastewater
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• v.18 no.6
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• pp.731-741
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• 2004

The purpose of this study was to evaluate the potential of a gamma ray irradiation to decompose hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) in an aqueous solution. The decomposition reaction of RDX by gamma ray irradiation was a first-order kinetic over the applied initial concentrations (10-40mg/L). The dose constant was strongly dependent on the initial concentration of the RDX. The removal of RDX was more efficient at pH below 3 and at pH above 11 than at neutral pH (pH 5-9). The required irradiation dose to remove 99% of the RDX (40mg/L) was 4, 8 and 1 kGy, at pH 2, 7 and 13, respectively. The dose constant was increased by two folds and over twelve folds at pH 2 and 13, respectively, when compared with that at pH 7. When an irradiation dose of 20 kGy was applied, the removal efficiencies of TOC were 80, 57 and 91% at pH 2, 7 and 13, respectively. Ammonia and nitrate were detected as the main nitrogen byproducts of RDX and formic acid was detected as an organic byproduct. The results showed that a gamma ray irradiation was an attractive method for the decomposition of RDX in an aqueous solution and it was found that a strong alkaline pH over 12 should be applied to the decomposition reaction of RDX.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.38 no.4
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• pp.302-312
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• 2001

As the data transfer rate between chips gets higher, both crosstalk and SSN (Simultaneous Switching Noise) deteriorate seriously the performance of a system. The proposed interface scheme uses P-CTR and N-CTR(Positive/Negative Constant Transition Rate) which encodes data at both falling and rising edges, where the transition directions of N-CTR and P-CTR are opposite. And the proposed bus system places two P-CTR drivers and two N-CTR drivers alternatively. In the proposed P/N-CTR interface scheme, the signals of neighboring interconnection lines at both sides of a bus will not switch simultaneously in the same direction, which leads to reduction in the maximum crosstalk and SSN compared to conventional interfaces. For verification of noise reduction of the proposed interface scheme, the scheme is applied to several kinds of bit-wide buses with various interconnection structures, and HSPICE simulation was performed with 0.35 ${\mu}{\textrm}{m}$ SPICE parameters. The simulation results show that in the 32-bit or less wide bus, the maximum SSN and crosstalk are reduced to at least 26.78% and 50%, respectively in comparison with the conventional interface scheme.

• Journal of the Korean Chemical Society
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• v.24 no.2
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• pp.129-138
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• 1980

The formation constants of the mixed-ligand complexes in the Cd(II), Cu(II) and Pb(II)-Trien-OH system were studied by polarograph. The formation constant $(log{\beta}_{ij})$ was determined at $25^{\circ}C$ in the ionic strength of 0.1. It was also confirmed that the mixed ligand complexes in this system were formed above pH 10.2, 10.5 and 9.0 for Cu(II), Cd(II) and Pb(II) by the calculation of the distribution for complexes at the various pH. Masking of Cd(II) by conversion to anionic EDTA-complexes has been used to separate Cu(II) from Cd(II) through passage of a combined Trien-EDTA solution on an cationic resin column. The optimal condition for the separation of Cu(II) from Cd(II) is confirmed at the pH range above 9.0, not only by considering the theoretical equation of the conditional-exchange-constant of metal on the cation exchange resin,but also by calculating the distribution of the mixed ligand complexes in the resin at the various pH with computer. By analyzing the synthetic sample of Cu(II) and Cd(II) with a EDTA masking at pH 9.5, it is found that the results of the experiment are satisfied with the theoretical value.

• Korean Journal of Poultry Science
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• v.21 no.4
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• pp.249-256
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• 1994

This study was conducted to investigate the effects of the addition of varied levels of NaCI and phosphates to the breast meat of spent layers(2 \pm 0.2 kg), which were stabilized for over 24 h before slaughter, on the protein extractability, thiobarbituric acid(TBA) and volatile basic nitrogen (VBN). Within 1 h after slaughter, breast meat was removed and treated with NaCI(0, 1, 2, 3%) and phosphates(0.25% and 0.5%) using a hot-salted method. The breast meat samples were stored at 4\pm$1^{\circ}C$ for 3 d. The results obtained were summarized as follows. 1. Soluble protein contents of salt-treated groups were significantly higher than that of control (P<0.05) and showed a positive relationship with the levels of salt. At a constant level of NaCI, the soluble protein content was proportionately elevated by the levels of phosphates (P<0.05). It decreased significantly in both control and salt-treated groups during storage (P<0.05). 2. TBA values of salt-treated groups were significantly higher than that of control(P<0.05) and showed a positive relationship with the levels of salt. At a constant level of NaCI, TBA values in 0.5% phosphates treatment groups were significantly lower than that in 0.25%(P<0.05). It increased significantly in both control and salt-treated groups during storage(P<0.05). 3. VBN values of salt-treated groups were significantly lower than that of control(P<0.05) They increased significantly by the salt treatment for the first day of storage(P<0.05), but not from the second day of storage. VBN values in both control and salt-treated groups were significantly increased during storage(P<0.05). After the first day of storage and at the same level of NaCI, no significant difference in VBN value was observed between the two levels of phosphates.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.3
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• pp.241-247
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• 2010

The Effects of operating parameters such as initial pH, gaseous ozone concentration, supplied gas flow rate on dissolved ozone concentration and phenol degradation in ozone contact reactor were investigated. Dissolved ozone concentrations were saturated to constant values after a certain ozone contact time. The saturation values were influenced by experimental parameters. Dissolved ozone concentration decreased with the increase of initial pH because the ozone is unstable in high pH regions. The gaseous ozone concentration in a constant gas supply affected the saturation concentration of dissolved ozone and the injection rate of gas with a constant ozone concentration determined the rate to reach dissolved ozone saturation. Effects of operating parameters on phenol degradation were closely related with those of parameters on dissolved ozone concentration. Phenol degradation was enhanced by the increase of initial pH, because the degradation of dissolved ozone gave birth to free radicals which have much higher reactivity with phenol. Increase of gaseous ozone concentration and gas flow rate promoted the phenol degradation through the generation of dissolved ozone which plays the role in phenol degradation. The injection of methanol deteriorated the phenol degradation through the scavenging effect on OH radicals.

• Bulletin of the Korean Mathematical Society
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• v.26 no.2
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• pp.185-190
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• 1989

In [4], J. Leray introduced the notion of partial hyperbolicity to characterize the operators for which the non-characteristic Cauchy problem is solvable in the Geverey class for any data which are holomorphic in a part of variables x"=(x$_{2}$,..,x$_{l}$ ) in the initial hyperplane x$_{1}$=0. A linear partial differential operator is called partially hyperbolic modulo the linear subvarieties S:x"=constant if the equation P$_{m}$(x, .zeta.$_{1}$, .xi.')=0 for .zeta.$_{1}$ has only real roots when .xi.'is real and .xi."=0, where P$_{m}$ is the principal symbol of pp. Limiting to the case of operators with constant coefficients, A. Kaneko proposed a new sharper condition when S is a hyperplane [3]. In this paper, we generalize this condition to the case of general linear subvariety S and show that it is sufficient for the solvability of Cauchy problem for the hyperfunction Cauchy data which contains variables parallel to S as holomorphic parameters.blem for the hyperfunction Cauchy data which contains variables parallel to S as holomorphic parameters.

• Magazine of the Korean Society of Agricultural Engineers
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• v.26 no.3
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• pp.90-98
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• 1984

In this paper, the anthor made a basic study of the storage function model and examined several constants in applying the storage function model to flood run-off analysis by dealing with the data in the Supyung and Hoyng Syung watershed, the applicabilities of the storage function model are examined by searching this optimum model parameters in two watersheds. The results are summarized as follows, 1) The optimum values of the exponential constants, P, in the storage function model showed to be 0.77 to 0.87 in two watersheds observed, therefore it was confirmed that the storage fumction model was approaching to the surface runoff model. 2) It was confirmed that the interval of variation of the storage constant, K, Showed to be larger than that of the exponential constant, p. 3) Relative erros in the discharge obtained by using the storage function model and the SDFP mothod showed to be 20 and 17 percent respectively to the observed discharge, therefore it was confirmed that the applicability of the storage function model using the SDFP method are excellent for runoff analysis. 4) A simple method is proposed for estimating the lag time in the storage function model.