• Proceedings of the KAIS Fall Conference
• /
• 2007.11a
• /
• pp.305-307
• /
• 2007

Struvite(MAP) 및 hydroxyapatite(HAP) 결정화로 질소 및 인을 제거하기 위한 최적조건을 평가하기 위한 실험을 실시하였으며, $Mg^{2+}$, $NH_4^+$, $PO_4^{3-}$ 및 $Ca^{2+}$용액을 이용하여 인공폐수를 조제하였으며 각 이온의 몰비 조건을 1:1:1에서 실험을 수행하였다. $Ca^{2+}$ 및 $PO_4^{3-}$를 이용한 HAP 결정화는 알칼리조건의 pH 범위에서는 pH에 큰영향을 받지 않고 HAP가 형성되었으며, MAP 및 HAP 동시 결정화를 위한 실험에서는 pH가 증가하면서 $NH_4^+$, $PO_4^{3-}$ 제거효율은 감소하며 $Ca^{2+}$ 및 $Mg^{2+}$는 모든 pH에서 99% 이상 제거되었다. 폐수중에 $Ca^{2+}$이 포함되어 있다면 pH 9.5에서 $Mg^{2+}:NH_4^+:PO_4^{3-}:Ca^{2+}$는 1.2:1.0:1.2:2.0의 몰비로 존재했을 때 MAP 및 HAP 생성 최적조건인 것으로 나타났다. 그러나 pH가 10이상이 되면 부반응으로 인해 각종 무정형 결정체가 생성되므로 MAP 생성을 위해서는 pH 9.5로 운영을 하는 것이 가장 바람직하다.

• Journal of the Korean Ceramic Society
• /
• v.25 no.5
• /
• pp.437-442
• /
• 1988

We have suffered number of problems in supplying bone ash for bone china bodies as raw materals, because of its impurity and quantity. To reduce these problems, we have synthesized tricalcium phosphate that was reacted by H2PO4 and CaCO3 ; 3Ca(OH)2＋2H3PO4longrightarrowCa3(PO4)2＋6H2O. Therefore, we have studied solid reactions of synthesized tricalcium phosphate withkaoline, limestone, feldspar and silica, respectively.

• Korean Journal of Microbiology
• /
• v.42 no.3
• /
• pp.223-229
• /
• 2006

To develop multifunctional microbial inoculant, an insluble phosphate-solubilizing bacterium with antifungal activity was isolated from plant rhizospheric soil. On the basis of its morphological, cultural and physiological characteristics and Biolog analysis, this bacterium was identified as Pseudomonas fluorescens RAF15. P. fluorescens RAF15 showed antifungal activities against phytopathogenic fungi Botrytis cinerea and Rhizoctonia solani. The optimal medium composition and cultural conditions for the solubilization of insoluble phosphate by P. fluorescens RAF15 were 1.5% of glucose, 0.005% of urea, 0.3% $MgCl_2{\cdot}6H_2\;0.01%\;of\;MgSO_4{\cdot}7H_2O\;0.01%,\;of\;CaCl_2{\cdot}2H_2O$, and 0.05% of NaCl along with initial pH 7.0 at $30^{\circ}C$. The soluble phosphate production under optimum condition was 863 mg/L after 5 days of cultivation. The solubilization of insoluble phosphates was associated with a drop in the pH of the culture medium. P. fluorescens RAF15 showed resistance against different environmental stresses like $10-35^{\circ}C$ temperature, 1-4% salt concentration and pH 2-11 range. The strain produced soluble phosphate to the culture broth with the concentrations of 971-1121 mg/L against $CaHPO_4$, 791-908 mg/L against $Ca_3(PO_4){_2}$, and 844 mg/L against hydroxyapatite, respectively. However, the strain produced soluble phosphate to the culture broth with the concentrations of 15 mg/L against $FePO_4$, and 5 mg/L against $AlPO_4$, respectively.

• Bulletin of the Korean Chemical Society
• /
• v.22 no.7
• /
• pp.782-784
• /
• 2001

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.5 no.3
• /
• pp.223-232
• /
• 1995

Abstract Urea($(NH_2)_2CO$) and THAMP (Tris(hydroxymethyl) aminomethane phosphate) are new organic nonlinear optical materials (NLO) for the device application such as the frequency conversion of laser radiation. The single crystals of urea and THAMP have been grown by the falling temperature method and the temperature difference method. The crystal growth parameters were presented associated with the molphology of the grown crystals. Based on the solubility measurements, methanol was a suitable solvent for the growth of urea. The solubilities of urea have a positive temperature coefficient and the heat of solution of urea was estimated to be -2.58 kcal/mol. The grown crystals of urea have the preferential growth habit in the z-axis. Additives such as $NH_4_H_2PO_4$, KCL, $H_3PO_4$, $CaCl_2{\cdot}2H_2O$, $C_2H_5OH$ were used for the favourable growth in the x - and y-axis and the preventive growth in the z-axis. The moleratio of THAM and H3P04 for the solution of THAMP was 1 : 1. The solubilities of THAMP have a positive temperature coefficient. The heat of solution was estimated to be - 1.70 kcal/ mol.

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

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.4 no.4
• /
• pp.311-320
• /
• 2006

Removal characteristics of $H^{14}CO_3$ ion from IRN-150 mixed resin contaminated with $^{14}C$ radionuclide and a gasification behavior of $^{14}C$ radionuclide to $^{14}CO_2$ were investigated. The stripping solutions used for the removal of $^{14}C$ from spent resin were $NaNO_3,\;Na_3PO_4,\;NH_4H_2PO_4,\;H_3PO_4$. The influence of stripping solution concentration on the desorption characteristics of inactive $HCO_3$ ion into stripping solution from IRN-150 mixed resin and the gasification of this ion to $CO_2$ was analyzed. The gasification behavior to $CO_2$ by using NaOH, $HNO_3$, HCl was also compared to that of phosphate solution. Real spent resin stored in Wolsung nuclear power plant was used to evaluate the gasification characteristics of $^{14}C$ radionuclide to $^{14}CO_2$. Gamma radionuclides such as $^{137}Cs,\;^{60}Co$ in residual striping solutions after desorption experiment were analyzed.

• Applied Biological Chemistry
• /
• v.30 no.1
• /
• pp.77-87
• /
• 1987

The mutant with high productivity, X. malvacearum SNUF 560-6, was acquired from the X. malvacearum SNUF 560 with low productivity by UV-light irradiation. It was preserved is lyophilized stock culture and it was transferred to PDA slant to maintain viability fortnightly. Fermentations were started by retransfering to MY agar slant from PDA stok culture. The experiments for optimal xanthan gum production were studied in a chemically defined medium. Of the carbon and nitrogen sources tested, 0.4% sucrose medium and 10mM glutamic acid medium yielded the highest xanthan gun production respectively. The addition of 10g/l succinic acid stimulated xanthan gum production. Also 65mM $PO_4\;^{-3}\;(12.6g/l\;KH_2PO_4)$ was effective on xanthan gum production. Finally, medium 1 and medium 2 which have high xanthan gum production potencies were achieved in this stud. The components of medium 1 and medium 2 were as follows: Medium 1 : sucrose 40g/l glutamate 10mM $PO_4\;^{-3}\;54mM\;(KH_2PO_4\;12.65g/l)$ Citrate 2g/l $MgSO_4{\cdot}7H_2O\;0.2g/l$ $H_3BO_3\;0.005/l$ ZnO 0.006/l $FeCl_2{\cdot}6H_2O\;0.0024g/l$ $CaCO_3\;0.02g/l$ Medium 2 : $Sucrose\;40g/l\;(NH_4)_2SO_4\;2g/l$ $PO_4\;^{-3}\;65mM\;(KH_2PO_4\;12.65g/l)$ Succinate 10g/l $MgSO_4{\cdot}7H_2O\;0.02g/l$ $H_3BO_3\;0.06g/l$ ZnO 0.006g/l $FeCl_2{\cdot}6H_2O\;0.0024g/l$ $CaCO_3\;0.02g/l$.

• Journal of the Korean GEO-environmental Society
• /
• v.7 no.6
• /
• pp.5-12
• /
• 2006

This study was conducted to investigate the effect of operational parameters such as dosage of magnesium and phosphate, pH, reaction time and existence crystal core for the removal of nitrogen and phosphorus in anaerobic fermentation supernatant by struvite crystallization. Optimal mole ratio of $Mg^{2+}:NH_4{^+}:PO_4{^{3-}}$ was 1.2:1.0:1.2. Under the optimal molar ratio, removal ratio and reaction rate constant of $NH_4{^+}-N$ and $PO_4{^{3-}}-P$ were 79.2, 96.8%, 0.157 and $0.344min^{-1}$, respectively. Optimal pH and reaction time were 11 and 10 minutes, respectively, in the optimal molar ratio. Residual concentration of $NH_4{^+}-N$ and $PO_4{^{3-}}-P$ showed lowest value with 1 g/L of crystal core addition. SEM analysis of struvite crystallization with crystal core showed higher crystal core growth than that of without crystal core. Struvite precipitate proved to be orthorhomic crystal structure by XRD analysis.

• Journal of Veterinary Clinics
• /
• v.30 no.3
• /
• pp.196-200
• /
• 2013

A 7 years-old intact female dog (4.8 kg) was referred with primary complaints of enlarged surface lymph nodes, cardiac murmur, coughing and exercise intolerance. Diagnostic imaging studies found cardiomegaly with distended caudal vena cava, marked left ventricular and interventrciular septal thickening and flattening, severe aortic and pulmonic stenosis (~5 m/s), and mitral and tricuspid regurgitation (~4 m/s). Cytology for the samples obtained from submandibular lymph node and left ventricle revealed high grade malignant lymphoma. The case was diagnosed as cardiac lymphoma. The dog was treated with prednisolone (2 mg/kg, PO, q24h), lomustine (80 $mg/m^2$ PO, q3wk), diltiazem (1 mg/kg, PO, q12h) and enalalpril (0.5 mg/kg, PO, q12h). The clinical signs were improved after therapy. The dog is still on the chemotherapy and regularly checked up.