• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2012.05a
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• pp.322-323
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• 2012

This study discussed the formation of phosphate conversion coatings on AZ31 Mg alloy (AZ31) from the zinc phosphating bath with various concentrations of sodium fluoride (NaF). The effects of NaF on the formation, structure, composition and electrochemical behavior of the phosphate coatings were examined using scanning electron microscopy (SEM), X-ray diffraction (XRD) weight balances, open circuit potential (OCP) transients, potentiodynamic polarization curves and immersion test. The coatings were composed of two layers: an outer $Zn_2(PO_4)_3.4H_2O$ (hopeite) crystal layer and an inner amorphous of $MgZn_2(PO_4)_2$. NaF concentration is emphasized to be highly effective in the formation of the hopeite crystal and etching and coating rates. Potentiodynamic polarization and immersion test showed that the coatings formed in the zinc phosphating bath with addition of NaF have much higher corrosion resistance than bare AZ31.

• Journal of Veterinary Clinics
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• v.22 no.3
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• pp.239-243
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• 2005

Current treatments for canine Giardia infections include albendazole, fenbendazole and metronidazole in the most cases. To compare efficacy of these antimicrobial drugs for treating naturally infected giardiasis in dogs, we used the zinc sulfate concentration technique(ZSCT) to figure out naturally infected with Giardia. In this study, feces were collected from 150 asymptomatic dogs at a kennel, 28 asymptomatic Giardia infected dogs were used by the allocated four group to receive albendazole(group A, 25 mg/kg, PO, bid, 7 days), fenbendazole(group F, 50 mg/kg, PO, sid, 7 days), metronidazole (group M, 50 mg/kg, PO, sid, 7 days), nontreated control(group NC) respectively. Fecal samples from each dog were examined for Giardia cysts within 3 days of the last treatment. Giardia cysts were not detected in the feces of any dog in group F. Cysts were detected in the feces 1 of 7 dogs in group A or in the feces 2 of 7 dogs in group M. In the group NC, cysts were detected in the feces of 7 of 7 dogs. Finally, there was significant difference for efficacy between antimicrobial drugs against Giardia in dogs. Fenbendazo1e is the most efficacy to have giardiacidal activity.

• Journal of the Korean Ceramic Society
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• v.37 no.8
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• pp.817-823
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• 2000

A solid-state electrochemicall cell for sensing CO2 gas was fabricated using a solid electrolyte of Li2CO3-Li3PO4-Al2O3 mixture and a reference electrode of LiMn2O4. The e.m.f. (electromotive force) of sensor showed a good accordance with theoretical Nernst slope (n=2) for CO2 gas concentration range of 100-10000 ppm above 35$0^{\circ}C$. The e.m.f. of sensor was constant regardless of oxygen partial pressure at the high temperature above 0.1 atm. It was, however, a little depended on oxygen partial pressure as the pressure decreased below 0.1 atm. The oxygen-dependency of our sensor gradually disappeared as the operating temperature increased. The sensing behavior of our CO2 sensor was affected by the presence of water vapor, but its effect was small comparing with other sensors.

• Korean Journal of Acupuncture
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• v.24 no.2
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• pp.193-216
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• 2007

Objectives : The aim of this study was to examine the effect of electroacupuncture (EA) at the PC8 on normal human beings by using power spectral analysis. Methods : EEG (Electroencephalogram) power spectrum exhibits site-specific and state-related differences in specific frequency bands. In this study, power spectrum was used as a measure of complexity. 32 channels EEG study was carried out in 20 subjects (20 males; age=26.8 years old). Results : In ${\alpha}(alpha)$ band, the power values at F7, F8, P3 channels(p<0.05) during the $PC_8-acupoint$ treatment significantly decreased. In ${\beta}(beta)$ band, the power values at F4, F8, P3 channels(P<0.05) during the PC8-acupoint treatment significantly decreased. In ${\delta}(delta)$ band, the power values at F7, F8, P3 Po2 channels(p<0.05) during the $PC_8-acupoint$ treatment significantly decreased. In ${\theta}(theta)$ band, the power values at F7, Fz, F4 F8, FTC1, FTC2, CP2, TT2, P3, Pz, Po2 channels(p<0.05) during the PC8-acupoint treatment significantly decreased. Conclusions : This results suggest that Electroacupuncture at the PC8 mostly affect the change on theta(11 channels) bands.

• Journal of the Korean Chemical Society
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• v.65 no.3
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• pp.197-202
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• 2021

In this study, activated clay treated with H₂SO₄ (20% by weight) and heat at 90 ℃ for 8 h for acid white soil was used as an adsorbent for the removal of PO₄^3--P in water. Prior to the adsorption experiment, the characteristics of activated clay was examined by X-ray Fluorescence Spectrometry (XRF) and BET surface area analyser. The adsorption of PO₄^3--P on activated clay was steeply increased within 0.25 h and reached equilibrium at 4 h. At 5 mg/L of low PO₄^3--P concentration, roughly 98% of adsorption efficiency was accomplished by activated clay. The adsorption data of PO₄^3--P were introduced to the adsorption isotherm and kinetic models. It was seen that both Freundlich and Langmuir isotherms were applied well to describe the adsorption behavior of PO₄^3--P on activated clay. For adsorption PO₄^3--P on activated clay, the Freundlich and Langmuir isotherm coefficients, K_F and Q, were found to be 8.3 and 20.0 mg/g, respectively. The pseudo-second-order kinetics model was more suitable for adsorption of PO₄^3--P in water/activated clay system owing to the higher correlation coefficient R² and the more proximity value of the experimental value q_e,exp and the calculated value q_e,cal than the pseudo-first-order kinetics model. The results of study indicate that activated clay could be used as an efficient adsorbent for the removal of PO₄³-P from water.

• Journal of the Mineralogical Society of Korea
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• v.22 no.1
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• pp.63-72
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• 2009

Carbon-coated lithium iron phosphate ($LiFePO_4/C$) composites are synthesized by the modified mechanical activation method (modified MA process) and studied by the Rietveld structural refinement. Rietveld indices of $LiFePO_4/C$ indicate good fitting with $R_p=8.14%,\;R_{wp}=11.1%,\;R_{exp}=9.09%,\;R_B=3.88%$, and S (GofF, Goodness of fit) = 1.2, respectively. $LiFePO_4/C$ with a space group Pnma shows a = 10.3229(3)${\AA}$, b = 6.0052(2) ${\AA}$, c = 4.6939(1) ${\AA}$, and V = 290.98(1) ${\AA}^3$ in dimension, indicating good agreements with those of previous works. Synthetic powders are nano-sized ($65{\sim}90nm$) homogeneous particles with high purity. Thus the modified MA method will be an efficient process to get a high quality cathode material for commercial lithium batteries.

• Horticultural Science & Technology
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• v.18 no.2
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• pp.98-102
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• 2000

This experiment was conducted to determine the effect of chemicals and their concentrations, priming temperature and duration, and different germination temperature on germinability of salvia seeds. The highest percentage of germination was obtained with 50 or 100 mM $KH_2PO_4$, or with -0.50 or -0.75 MPa PEG 8000. When number of days to attain 50% of the final germination percentage (T50) and mean number of days to germination (MDG) were taken into account, 50 mM $KH_2PO_4$ or -0.50 MPa PEG was most effective for early germination. No seeds germinated when primed in $K_3PO_4$ or NaOH solution. Priming the seeds at $20^{\circ}C$ was better than priming at $15^{\circ}C$ or $25^{\circ}C$. Priming at $20^{\circ}C$ for 4 or 6 days reduced the MDG by 2.3 days compared with nonprimed seeds. Seeds primed with -0.50 MPa PEG at $20^{\circ}C$ showed a high germination percentage with reduced T50 and MDG. When seeds were primed in a mixture of -0.50 MPa PEG and 50 mM $KH_2PO_4$ solution and germinated at $30^{\circ}C$ or $35^{\circ}C$, percent germination was lower than nonprimed seeds. However, the combined treatment retained the priming effect for reducing T50 and MDG.

• 보존과학연구
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• s.15
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• pp.128-136
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• 1994

To restore the Under glaze Blue -White porcelain kiln site of choson period, where is located at 114, SanBon 2 Dong GunPo city. it was used to the conservation method, particularly F.R.P.(Fiber glass Reinforced plastic) for moving the kiln site from the present area to historic site No. 342 after restoration.

• The Journal of Korean Physical Therapy
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• v.3 no.1
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• pp.59-73
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• 1991

The purpose of this study was to phychosomatic health status of physical therapy college mans. 130college mans analysis sex, habitation, religion, blood type, drinking, somoking by the todai health index questionaire. THI was modified front cornell medical index. Physical therapy college man showed complain score (E) Nervousness. (J) Mental irritability. (H) Impulsiveness. (F) Aggressiveness. (G) Irregular life (I), (L) Multiple subjective symtom(I), Live scale(L), (K) Depression. (C) Digestive, (A), (B) Respiratory(A), Eye and Skin(B). (D) Mouth and Anus.

• Carbon letters
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• v.6 no.2
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• pp.89-95
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• 2005

Crushed peach stone shells were impregnated with $H_3PO_4$ of increasing concentrations (30-70%) followed by heat treatment at 773 K for 3 h. Produced carbons (ACs) were characterized by $N_2$ adsorption at 77 K using the BET-equation and the ${\alpha}$-method. High surface area microporous ACs were obtained, with enhanced internal pore volume, as function of % $H_3PO_4$. Adsorption isotherms from aqueous solution were determined for methylene blue (MB) and p-nitrophenol (PNP), as representatives for dye and phenolics pollutant molecules. Application of the Langmuir model proved the high limiting capacity towards both solute molecules, MB was uptaken in increasing amounts as function of $H_3PO_4$ concentration and generated porosity. High removal of PNP was almost the same irrespective of porosity characteristics. Competitive adsorption of $H_2O$ molecules on the hydrophilic carbon surface seems to partially reduce the available area to the PNP molecules. Application of the pseudo-second order law described well the fast adsorption (${\leq}$ 120 min) at two initial dye concentrations.