• Journal of the Korean Society of Radiology
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• v.17 no.1
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• pp.37-46
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• 2023

This study aims to evaluate the usefulness of Deep Learning Image Reconstruction (TrueFidelity, TF), the image quality of existing Filtered Back Projection (FBP) and Adaptive Statistical Iterative Reconstruction-Veo (ASIR-V) were compared. Noise, CNR, and SSIM were measured by obtaining images with doses fixed at 17.29 mGy and altered to 10.37 mGy, 12.10 mGy, 13.83 mGy, and 15.56 mGy in reconstruction techniques of FBP, ASIR-V 50%, and TF-H. TF-H has superior image quality compared to FBP and ASIR-V when the reconstruction technique change is given at 17.29 mGy. When dose changes were made, Noise, CNR, and SSIM were significantly different when comparing 10.37 mGy TF-H and FBP (p<0.05), and no significant difference when comparing 10.37 mGy TF-H and ASIR-V 50% (p>0.05). TF-H has a dose-reduction effect of 30%, as the highest dose of 15.56 mGy ASIR-V has the same image quality as the lowest dose of 10.37 mGy TF-H. Thus, Deep Learning Reconstruction techniques (TF) were able to reduce dose compared to Iterative Reconstruction techniques (ASIR-V) and Filtered Back Projection (FBP). Therefore, it is considered to reduce the exposure dose of patients.

• Journal of the Korean Chemical Society
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• v.17 no.6
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• pp.428-433
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• 1973

The quantitative separations of a mixture containing equal amount of each anion such as Si(IV), As(V), P(V), S(VI), W(VI) and Cr(VI) are carried out by the elution through 20${\times}3.14cm^2$ column of anion exchange resin, Dowex 1${\times}$8. The eluents are a mixture of 0.07 M hydrochloric acid and 0.03 M sodium chloride (pH = 1.30) for Si(IV), As(V) and P(V) species, a mixture of 0.6 M sodium chloride and 0.3 M sodium hydroxide for S(VI), W(VI) and Cr(VI) species, and 0.1 N sodium sulfite (pH = 3.48) for P(V) and As(V) species. The subsidiary anions in a standard mixture such as Si(IV), As(V), S(VI), P(V) and W(VI) are separated together from large amount of Fe(III) by the elution through 30cm${\times}3.14cm^2$ column of the resin, Dowex${\times}$50w${\times}$12, using a mixture of 0.1 M sodium nitrate and 2 percent dimethylsulfoxide aqueous solution as an eluent. Si(IV), As(V), S(VI), P(V) and W(VI) eluted together are separated quantitatively under the same conditions as in the separations of the anion mixture. By the conditions obtained in the separations of the standard mixture, Fe(III) and all of the subsidiary anions in steel are quantitatively separated.

• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.183-187
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• 2015

We use ALLWISE data release W1- and W2-band epoch photometry collected by the Wide-Field Infrared Survey Explorer (WISE) to determine slopes of the period-luminosity relations for RR Lyrae stars in 15 globular clusters in the corresponding bands. We further combine these results with V- and K-band photometry of Galactic field RR Lyrae stars to determine the metallicity slopes of the log $P_F-[Fe/H]-M_K$, log $P_F-[Fe/H]-M_{W1}$, and log $P_F-[Fe/H]-M_{W2}$ period-metallicity-luminosity relations. We infer the zero points of these relations and determine the kinematical parameters of thick-disk and halo RR Lyraes via statistical parallax, and estimate the RR Lyrae-based distances to 18 Local-Group galaxies including the center of the Milky Way.

• Analytical Science and Technology
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• v.11 no.4
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• pp.235-242
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• 1998

Membrane electrode based on chitin(po1y-[$1{\rightarrow}4$]-${\beta}$-N-acetyl-D-glucosamine) was prepared by mixing uniformly grounded of chitin (100 mesh) with PVC and DOS. We investigated the potential response of chitin membrane electrode to metal ions. It was observed that the response slopes for $Cd^{2+}$(34.9 mV/decade) and $Cu^{2+}$(34.0 mV/decade) were larger than those for other ions in pH 4 acetate buffer. The potentiometric response of chitin electrode to varying pH was nearly constant in the pH range of 2~12.

• Applied Biological Chemistry
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• v.37 no.2
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• pp.124-129
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• 1994

The rate of hydrolysis of insecticidal $O,O-diethyl-{\alpha}-cyanobenzylideneamino-oxyphosphorothioate\;(Volaton^{\circledR})$ has been studied in 25% (v/v) aqueous dioxane. On the basis of solvent effect (pH 6.0; m=0.21, n=1.55, pH 12.0; m=0.42, n=3.14 & $|m|{\ll}|l|$), general base catalysis, hydrolysis product analysis, calculation of molecular orbital (MO) and rate equation, it may be concluded that the hydrolysis of Volaton proceeds through the $A_{AC}2$ mechanism via trigonal bipyramidal $(sp^3d^2)$ intermediate below pH 7.0, while above pH 9.0 the hydrolysis proceeds through the $B_{AC}2$ mechanism. Hydrolysis reactivity of Volaton depends on positive charge strength $(p{\gg}{\alpha}C_2)$ rather than steric hindrance. In the range between pH 7.0 and pH 9.0, these two reactions occur competitively.

• Analytical Science and Technology
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• v.9 no.1
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• pp.78-83
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• 1996

Hydrogen ion-selective membrane electrodes based on tribenzylamine(TBA), tetrabenzylethylenediamine(TBEDA), pentabenzyldiethylenetriamine(PBDETA) as neutral carriers were shown good selectivity and linearity in the range of pH 1~pH 9, pH 2~pH 12, pH 4~pH 12. The pH selectivity of this membrane electrodes have nothing relation with the numbers of unshared electron pair in TBA, TBEDA, PBDETA and were shown a slope of 43.8mV/pH, 46.9mV/pH, 43.6mV/pH respectively. The selectivity coefficients were determined by the separate solution method for alkali($Li^+$, $Na^+$, $K^+$), alkaline earth metal($Ba^{2+}$, $Ca^{2+}$, $Mg^{2+}$) and transition metal ions($Mn^{2+}$, $Co^{2+}$, $Ni^{2+}$, $Cu^{2+}$, $Zn^{2+}$). The membrane electrode based on TBEDA appeared the best results as hydrogen ion electrode.

• Journal of Applied Biological Chemistry
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• v.54 no.3
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• pp.153-158
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• 2011

Optimal culture conditions were characterized for production of crude biosurfactant of Bacillus subtilis JK-1. During incubation of B. subtilis JK-1, the bacterial growth pattern, changes of the surface tension at variable temperatures, pH and NaCl concentrations in bacterial culture medium were studied. The strain was able to grow and produce biosurfactant at $15-45^{\circ}C$, in the pH range of 6-10, and at 0-10% (w/v) NaCl. In case, culture broth pH was gradually changed to neutral or weak alkaline. Optimal culture conditions for crude biosurfactant production were at $35^{\circ}C$ and pH 7.0 after 48 h incubation and the surface tension of biosurfactant was 24.0 mN/m. Besides, as the concentration of NaCl was increased from 0 to 10% (w/v), the growth was decreased, pH of the culture broth was converted from weak alkaline to acidic, and the surface tension rised.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.13 no.2
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• pp.1-4
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• 1977

The author determined the relationship between the hauling veloicty and the hydrodynamic resistance of the sablefish pot shaped conic frustum like, and induced the formulae to determine the diameter of the main line and the net horse power of the pot hauler. The results are summarized as follows: 1. The maximum hydrodynamic resistance (with its weight in water) of the pot T(kg), when the bottom webbing is covered by a cloth to imitate the catches are scattered on the bottom, is eatimated as $$ T=120v^{1.1} (0.3{\leqq}v{\leqq}0.8) $$ where v denotes the hauling velocity of the pot in m/sec. 2. When P. P. 3 strand rope is used as main line, the diameter d(mm)is recommended to satisfy the formula $$ d=72 \frac{D}{H} V^{1.1} where H denotes the depth of the fishing ground and D the intervals of the pots linked to the main in m respectively. 3. The pot hauler must displace the net horse power p(ps) of $$ P= \frac{75}{120} \frac{D}{H} v^{2.1}$$

• Korean Chemical Engineering Research
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• v.51 no.1
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• pp.111-115
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• 2013

The optimum synthetic conditions of poly(p-phenylphenol) by horseradish peroxidase in dioxane:water (80:20 v/v) mixtures were studied. The stability against thermal degradation and structural properties of the synthesized phenolic resins were investigated by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), respectively. The synthetic yield of poly(p-phenylphenol) increased upon the increase of the amount of enzyme up to 0.25 mg HRP/mL, then leveled off for further increase of the enzyme usage. When sodium acetate (100 mM, pH 4~6) and sodium phosphate (100 mM, pH 7~9) were used as the buffering salts for the aqueous component (20% v/v), the synthetic yield of the resin increased at higher pH of the aqueous buffer. But when the pHs of the aqueous buffer were 6 and 9, the synthetic yield strongly depended on the types of the buffering salts; if sodium phosphate was used instead of sodium acetate at pH 6, the yield decreased by about 15% and if sodium bicarbonate was used instead of sodium phosphate, the yield decreased by almost 20%. When the pH range of the aqueous buffer was from 4 to 7, the addition of a radical mediator, 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonate) (ABTS), up to 2 mM improved the synthetic yield of the resin by about 10%. TGA experiments revealed that the thermal stability of the resin synthesized in dioxane:water (100 mM sodium phosphate, pH 9) (80:20 v/v) was high having the char yield of 47% upon the heating at $800^{\circ}C$. DCS results showed that the structures of the polymers synthesized in acidic aqueous buffers were different from those of the polymers synthesized in the basic aqueous buffers. However, all the synthesized resins were found to have the property of the thermosetting resins.

• Journal of the Korean Chemical Society
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• v.62 no.4
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• pp.269-274
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• 2018

Surface renewable nano-$RuO_2$/poly(methyl methacrylate) polymeric composite pH electrodes were prepared. The composite electrode with 53 wt% of nano-$RuO_2$ showed similar good response characteristics to nano-$IrO_2$ composite electrode reported earlier. It showed response slope of -58.7 mV/pH, response time of <1 s, surface renewability of $-57.0{\pm}0.3mV/pH$ (n=5) and long time stability for a month as well as low interferences but high interferences by electrochemically active species like $I^-$ and $Fe(CN){_6}^{3-}$. However, the response slope and time became worse at higher pH than 9 compared to those of nano-$IrO_2$ composite electrodes possibly due to the difference of physical properties resulting from higher content of nano-$RuO_2$ in polymeric composite matrix.