• Journal of the Korean Chemical Society
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• v.66 no.2
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• pp.86-91
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• 2022

The manure made of chaff and sawdust as litter was collected separately at a cowshed of a livestock farm in Andondg city. The fermentation efficiency of excreta is greatly influenced by the type and characteristics of litter and a factor to be considered for reducing N and P, the causes of eutrophication. Changes in weight with temperature and constituents of sample were examined using TG-DTA and XRF, respectively. NO₂^-, NO₃^-, and PO₄^3- ions and NH₄⁺, T-P and T-N eluted from manure by rain were analyzed using ion chromatograph and UV/Vis spectrometry, respectively. As a result, the fermentation efficiency of excreta in sawdust manure is three times higher as compared with chaff manure. The higher the fermentation efficiency, ammonia nitrogen was highly de-nitrogenated and organic phosphorous were also changed into phosphorous ions. Furthermore, phosphorous ions can be removed by transforming insoluble salts such as calcium phosphate (CaHPO₄·3H₂O) and struvite (NH₄MgPO₄·6H₂O) with addition of Ca and Mg.

• Journal of the Korean Chemical Society
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• v.19 no.5
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• pp.325-330
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• 1975

Complex formation between ferric ion and phosphoric acid has been studied in the wide range of the acid concentration(0${\sim}40{\%}$) by uv-visible spectroscopy and by characterization of the isolated products. The electronic spectra of Fe(III)-containing phosphoric acid solutions exhibit two visible bands at 19.2 and 24.1 kK, which are characteristic of Fe(III)-phosphate complex formation. The measurements of acid concentration dependence of the opical density of the 24.1 kK band indicates the presence of two distinct forms of Fe(Ⅲ)-phosphate complexes possibly $[Fe(H_xPO_4)]^{x+}\;and\;[Fe_2 (H_xPO_4)]^{(3+x)+}$. The 1:1 complex has been isolated for characterization, and the phosphate ion was found to be coordinated to the metal in monobasic state whereas the isolation of the dimeric species was unsuccessful.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.3
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• pp.192-200
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• 2009

Soil testing is one of the best management practices for sustainable agriculture. Recently, as increasing soil testing needs, simplification of soil analytical procedure has been required. To determine recommendable multi-element extractant, the soil testing results of available phosphate and exchangeable cations between the conventional methods (Lancaster and 1M $NH_4OAc) and multi-element extraction methods such as Mehlich III, Modified Morgan and Kelowna methods were compared. There were highly significant correlation between the conventional methods and multi-element extraction methods (Mehlich III, Modified Morgan and Kelowna) for available phosphate and exchangeable K, Ca, Mg and Na. The coefficients of determination ($R^2) between available phosphate extracted by Lancaster method and multielement extraction methods were in the order of Mehlich III ($0.979^{***}$) > Kelowna ($0.977^{***}$) > Modified(Mod.). Morgan ($0.553^{***}$). For exchangeable cations, there were highly significant correlations between 1M $NH_4OAc method and Mehlich III, Mod. Morgan and Kelowna. However, exchangeable K, Ca and Mg by Mehlich III method were more highly correlated with conventional method than other methods. Therefore, Mehlich III extraction method could be recommended as a single extractant for simultaneous measurement using ICP in the analysis of avaliable phosphate and exchangeable cations.

• Applied Biological Chemistry
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• v.44 no.2
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• pp.92-96
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• 2001

Soil physical-chemical properties and phosphorous adsorption characteristics were investigated to obtain the informations of the appropriate fertilization and soil management in Baicheng region, China, where agricultural circumstances at present forces to consider the use of land for crop production. Soils were collected from one uncultivated and three cultivated lands on August 1993. Soil $_PH$ was very higher in uncultivated land than in cultivated land, their values were 10.2 and 7.4, respectively. Regardless of cultivation, soil organic matter contents were below 2%, and concentrations of available soil phosphorus expressed as Bray 1 P and Olson P were less than 10 mg P $kg^{-1}$, however, cation exchange capacity was higher than 20 cmol(+) $kg^{-1}$. For uncultivated soil, the values of exchangeable sodium percent and calcium saturation percent were higher than 100%. The major cation of soil saturation paste extracts was Na regardless of land use type. Based on electrical conductivity and sodium adsorption ratio of saturation paste extracts, uncultivated soil was classified as saline-sodic soil and cultivated soil was classified as sodic or normal soil. The maximum adsorption capacity of phosphorus calculated by Langmuir isotherm ranged from 406 to 521 mg P ,$kg^{-1}$. The constraints of soils in Baicheng regions for agricultural cops werw high salt concentration, unfavorable soil chemical composition such as low concentration of available phosphorous, and poor drainage due to soil dispersion by high Na concentration. Therefore, the soil in Baicheng region, need the application of phosphorus fertilizer to increase the soil fertility and the proper soil management to improve the soil physical property especially permeability and soil structure.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.285-285
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• 2013

수산화인회석(Hydroxyapatite, HAP)은 인체 내 뼈와 치아의 주성분으로서 칼슘과 인산염으로 구성된 물질이다. 암모늄을 이용하여 pH를 조절함으로서 hexagonal 형태의 HAP를 수열합성법으로 합성하였다. XRD pattern을 통하여 수산화인회석의 결정구조를 확인하였으며, 전이금속 중의 하나인 Fe(III) 이온을 이온교환반응을 통하여 수산화인회석 표면에 도입하였다. ICP 측정을 통해 Fe 함량을 정량하였고 SEM과 TEM image를 통하여 크기와 형태를 관찰하였다.

• Journal of Environmental Science International
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• v.12 no.9
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• pp.1011-1016
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• 2003

Adsorption of phosphate, sulfate, and copper ion to goethite was investigated. Goethite was prepared in the alkaline solution. In the single adsorbate systems, the final equilibrium plateau reached within 20 min. The adsorption isotherms of the individual ions could be well described by the Langmuir equation. The maximum adsorption capacities (q$\_$max/) were calculated as 0.483 m㏖/g and 0.239 m㏖/g at pH 3 for phosphate and sulfate ion, and 0.117 m㏖/g at pH 6 for copper ion, respectively, In competitive adsorption system with phosphate and sulfate, phosphate ion was a stronger competitor for adsorption on goethite than sulfate ion, which was consistent with higher affinity of phosphate ion for the surface compared to sulfate ion. The existence of sulfate ion enhanced the adsorption of copper ion but the adsorption of sulfate was inhibited when copper ion was present.

• Applied Biological Chemistry
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• v.43 no.3
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• pp.163-168
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• 2000

To remove phosphate accumulated in the soil and water, Acinetobacter lwoffi PO8 possessing a high ability to accumulate phosphate was isolated from a active sludge. Bacterium was cultured in the liquid medium containing $150\;{\mu}g/mL$ of phosphate at $30^{\circ}C$ in different culture conditions to examine intracellular phosphate uptake. The initial pH in the range of $7.5{\sim}8.5$ was effective on the growth and phosphate uptake of the strain. Glycerol and arabinose used as a carbon sources showed 93 and 91% the phsphate uptake, respectively. Among the nitrogen sources, ammonium salt such as $NH_4NO_3$ and $(NH_4)_2SO_4$ was effectively utilized on the phosphate uptake compared with amino compounds. The rate of phosphate uptake of $NH_4NO_3$, and $(NH_4)_2SO_4$, was 95 and 96%, respectively The growth and Phosphate uptake ability in the strain were significantly promoted when metal ions were added in the medium; $Co^{2+}$, however, was not utilized by the strain. The capacity of phosphate uptake was enhanced to $10{\sim}20%$ when arginine, methionine, or lysine was added. Using $^{32}P$ to examine the uptake Pattern of intracellular phosphate, experiment result showed that polyphosphate was largely found in the fraction of intracellular inorganic phosphate of Acinetobacter lwoffi PO8.

• Korean Journal of Soil Science and Fertilizer
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• v.41 no.5
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• pp.348-353
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• 2008

With the aim to explore the possible role of phosphate-solubilizing bacteria in soil, we conducted a survey of phosphate-solubilizing microorganisms colonizing in upland and plastic film house soils. Soil EC, pH, organic matter, available phosphate, exchangeable cation such as potassium, calcium and magnesium, and total P of plastic film house soils were higher than those of upland soils. Phosphate-solubilizing bacteria population was higher in plastic film house soils than upland soils, but species of phosphate-solubilizing bacteria was more diverse in the upland soils than the plastic film house soils. There was significant positive correlation between phosphate solubilization and phosphate-solubilizing bacteria in soils. Bacillus, Cedecea, Brevibacillus, Paenibacillus, Pseudomonas, Serratia spp. were isolated from upland soils and Bacillus and Cellulomonas spp. were from plastic film house soils.

• Journal of the Korean Applied Science and Technology
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• v.37 no.5
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• pp.1222-1228
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• 2020

The adsorption and ion exchange properties of tin phosphate were studied in an aqueous solution of KCl, varing the pH and metal ion concentration in the solution. The data were explained on the basis of chemical equilibrium. Tin phosphate behaved as an acidic ion exchanger and had an adsorption selectivity toward the bivalent transition metal ions in the following order : Cu⁺² > Co⁺² > Ni⁺². As in the case of a weekly acidic exchanger, the change in hydration of metal ions played the dominant role in determining the selectivity of tin phosphate. In all cases the extent of adsorption increased with an increase in temperature and concentration. The apperance of irregular kinks in the titration curves justified the presence of several exchangeable adsorption sites with different pKa values.

• The Korean Journal of Pharmacology
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• v.30 no.1
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• pp.111-116
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• 1994

The role of $Ca^{2+}$/calmodulin-dependent protein kinase II in the increase of myofilament $Ca^{2+}$ sensitivity by agonist and GTP was investigated in rabbit mesenteric ${\alpha}-toxin$ permeabilized artery. $0.3{\mu}M\;Ca^{2+}$ increased myosin light chain phosphorylations monotonically. $10\;{\mu}M$ norepinephrine and $10\;{\mu}M$ GTP potentiated increase of myosin light chain phosphorylations by $0.3{\mu}M\;Ca^{2+}$, which reaches a peak at 5 min and gradually declines to the $Ca^{2+}$ alone level at 20 min. At the early phase (1 min), $10\;{\mu}M$ KN 62, the inhibitor of $Ca^{2+}$/calmodulin-dependent protein kinase II , decreased myosin light chain phosphorylation levels by $10\;{\mu}M$ norepinephrine and $10\;{\mu}M$ GTP in the presence of $0.3{\mu}M\;Ca^{2+}.\;However\;10\;{\mu}M$ KN-62 did not affect the myosin light chain phosphorylations by $10\;{\mu}M$ norepinephrine and $10\;{\mu}M$ GTP in the presence of $0.3{\mu}M\;Ca^{2+}$ at the peak (5 min) and plateau phases (20 min). From these results, the role of $Ca^{2+}$/calmodulin-dependent protein kinase II may be different depending on time, which may play a role in increase of myofilamint $Ca^{2+}$ sensitivity by norepinephrine and GTP resulting from increase of myosin light chain phosphorylations at the early phase. However, at plateau phase, $Ca^{2+}$/calmodulin-dependent protein kinase II may not be involved in the increase of myofilament $Ca^{2+}$ sensitivity by norepinephrine and GTP in rabbit mesenteric ${\alpha}-toxin$ permeabilized artery.