• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.7
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• pp.357-364
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• 2017

In this paper, we investigated the influence of flow and compressive strength on the mixing ratio and water-to-binder (W/B) ratio of magnesia - potassium phosphate composites for controlling the quality of the Magnesia-Potassium Phosphate Composites(Magnesia-Potassium Phosphate Composites, MPPC) as a matrix material for biological panels. MPPC was produced at 7 W/B ratios (30, 35, 40, 45, 50, 55 and 60 vol.%) and 4 P:M ratios (1:0.5, 1:1.0, 1:2.0 and 1:3.0). The experiment results confirmed that the flow and compressive strength of MPPC depend strongly on both P:M and W/B ratios. The flow of MPPC showed that as P: M was increased, the mixing did not occur due to the shortage of the compounding amount for the reaction, because of the large density difference between P and M. The compressive strength of MPPC showed a tendency to decrease with increasing P:Mratio but there was a contradictory result with no proportional change according to W/B ratio. These results indicate that the optimum compounding ratio exists for MPPC according to W/B ratio. These results will be used as the basis data for quality control of the fluidity and compressive strength of matrix materials in terms of material in biological panel design.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.31 no.2
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• pp.242-248
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• 1986

To study the effect of cold water irrigation at the reproductive growth stage of rice plants on several growth characters related to source and sink and nutrient uptake, the present experiment was carried out under the different conditions of water temperature and water depth. Deep irrigation with normal temperature water increased culm length, panicle length and panicle exsertion but with cold water resulted adversely. Most sensi-tive response in 5 cm water-depth appeared at reduction division stage and in 20 cm depth at panicle formation stage. Secondary branches and spikelets were increased in number by deep irrigation with normal temperature water, but decreased and degenerated by deep irrigation with cold water at panicle formation stage resulting in high spikelet sterility and low grain filling. Deep irrigation with normal temperature water increased the contents of total nitrogen, phosphate, potassium and silicate in leaf blades, branches and chaff. However, cold water irrigation reduced the uptake of phosphate, potassium and silicate except nitrogen particularly in deep irrigation. Ratios of phosphate, potassium and silicate to total nitrogen content were decreased by cold water irrigation. Branches seemed to have higher requirements for phosphate, potassium and silicate than leaf blades and chaff. Silicate-to-total nitrogen ratio in leaf blades, branches and chaff had significant correlations with yield showing closer relationship between yield and the ratio of silicate to total nitrogen in branches in particu-lar.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.13 no.1
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• pp.29-35
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• 1987

Purely synthesized L-ascorbic acid 2 phosphate Mg salt (1 AsA PMg) improved the weak point of ascorbic acid which is easily decomposed in water solution. This compound is hydrolyzed with phosphatase of skin to corresponding ascorbic acid giving Vitamine C activities. The buffer solution of potassium acetate 0.5% and citric acid 0.005% and the sodium sulfite respectively showed good stabilizing effect of the AsA PMg solution. Compared to the other ascorbic acid derivatives the good solubility of AsA PMg gives broad application to cosmetic field.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.414-417
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• 2001

This research was compared the amount of phosphate solublized by Pantoea agglomerans which can solublize the insoluble phosphate salt hydroxyapatite with the phosphate produced by being treated with various acids. When P. agglomerans grows in the BY medium containing potassium dihydrogenphosphate of phosphate source without hydroxyapatite, it consumed 361mg/L phosphate, during 72hours cultivation. When 4% hydroxapatite was treated with 0.01N citric acid and oxalic aicd, the amount of solublized phosphate was 702mg/L and 537mg/L more than that by P.agglomerans. The maximum amount of solublized phosphate by P. agglomerans was 465mg/L after 48 hours cultivation.

• Korean Journal of Soil Science and Fertilizer
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• v.16 no.1
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• pp.36-41
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• 1983

These studies were carried out to investigate the effects of potassium salts on the changes of chemical properties in submerged soil. Rice plants were cultured in submerged soil using potassium salts. Obtained results were as follows. In the submerged soil cultured with rice plants the value of pH was higher in the potassium chloride plot than in the potassium sulfate plot. The leaching of cations such as calcium, magnesium, potassium and ammonium were higher in the potassium chloride plot than in the potassium sulfate plot. On the other hand, the leaching of phosphate ion was slightly higher in the potassium sulfate plot than in the potassium chloride plot. The leaching of iron was higher in the planted plot than in the non-planted plot, but that of silica was higher in the non-planted plot than in the planted plot. However, the leaching of iron and silica was not affected by potassium salts.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.2
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• pp.314-322
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• 2004

The production of a glucan was affected by the concentration of ions and buffer solutions, and nutrients in an oral cavity. In this study, the effects of ions and buffer solutions on the mRNA expression of gtfD gene in Streptococcus mutans, an important causative agent of dental caries, were investigated by Fluorescent in situ hybridization(FISH). At first, ions and buffer solutions had little effect on the multiplication of Streptococcus mutans. The green fluorescence according to the mRNA expression of gtfD gene was detected in the BHI broth containing 1% sucrose. The intensities of the green fluorescence were strong at 0.25mM of $CaCl_2$. Little fluorescence was detected by the addition of KCl, except far 10mM KCl at which fluorescence intensities were similar to those of the control. Fluorescence intensities were weak at each concentration of $MgCl_2$ when compared to the control. As for buffer solutions, fluorescence intensities were similar to those of the control at each concentration of buffer solutions, except that they were little detected at 100mM of potassium phosphate.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.3
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• pp.265-270
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• 2016

Accumulated Phosphate can be released by ligand exchange reaction of organic acids. The objective of this study was to evaluate effects of the organic acids on the availability of phosphate and the growth of crop in phosphate and salts accumulated soil. Soil samples were collected from farmer's plastic film house. Available phosphate and electrical conductivity of soil were $3,005mg\;kg^{-1}$ and $16.63mg\;kg^{-1}$ which were 6 and 8 times higher than the optimum range of soil for crop growth, respectively. Corns were cultivated in pots for 2 months. Treatments were no treatment (control), phosphate fertilizer (P), citric acid (CA) 1, 5, 10 mM, and oxalic acid (OA) 1, 5, 10 mM. Water soluble phosphorus, available phosphate, corn growth and uptake were determined after cultivation. Results showed that organic acids increased water soluble phosphorus and available phosphate. For the level of 10 mM, the order of effectiveness of organic acids for water soluble P was citric acid (44%) > oxalic acid (32%). Height and dry weight of corns were increased significantly by the treatment of citric acid 1 and 5 mM. Also, corn absorbed more phosphorus, nitrogen, potassium, calcium and magnesium in the treatment of citric acid 1 mM than these of other treatments. Even though phosphate availability of soil was enhanced by addition of citric acid 10 mM, the growth of corns decreased because high concentration of citric acid caused salt damage by increasement of electrical conductivity. Thus, the citric acid of 1 mM has the potential to improve the availability of phosphate and the healthy growth of corns.

• The Korean Journal of Mycology
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• v.23 no.1 s.72
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• pp.53-60
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• 1995

Nutritional requirements for the growth of Flammulina velutipes were studied. Mannitol, glutamic acid and ammonium nitrate were chosen for the maximum mycelial growth when various carbon and nitrogen sources tested. Optimum C : N ratio for the mycelial growth was 20 : 1. Potassium dihydrogen phosphate was selected among the phosphate sources. Magnesium sulphate and thiamine HCl stimulate mycelial growth. Final compositions of optimized chemically defined medium were 1.5% mannitol, 0.082% $NH_4NO_3$, 0.312% glutamic acid, 0.25% $KH_2PO_4$, 0.06% $MgSO_4{\cdot}7H_2O\;and\;0.3\;{\mu}g/l$ thiamin HCl. This medium not only support mycelial growth but also induce fruit body formation.

• Korean Journal of Soil Science and Fertilizer
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• v.2 no.1
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• pp.31-38
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• 1969

This experiment was carried out to determine the effect of different levels of phosphate and potash firtilizers applied on yields and quality of leaf tobacco. It was done at all varying levels of phosphate and potassium fertilizers $S_0$ (non-fertilizer plot);N:P:K=0:0:0 (Kg/10a) $S_1$ (1/2 amount plot);N:P:K=10:7.5:10 (Kg/10a) $S_2$ (standard plot);N:P:K=10:15:20 (Kg/10a) $S_3$ (1.5 times plot);N:P:K=10:22.5:30(Kg/10a) $S_4$ (2.0times plot);N:P:K==10:30:40 (Kg/10a) Urea was applied as nitrogen, triple superphosphate as phosphate, potassium sulfate as potash source. The total amount of fertilizers was applied as basal dressing per one plant. This experiment was carried out by using randomized block design with 3 replication. The results obtained in terms of yields and quality are summarized as follows. 1. By increasing the amounts of phosphate and potassium fertilizers, growing status of the largest leaf length, the largest leaf width and stem size of tobacco increased in the order of $S_4>S_3>S_2>S_1>S_0$. 2. By increasing the amount of phosphate and potassium fertilizers, yield was increased in the order of $S_4>S_3>S_2>S_1>S_0$, This increase showed generally high significance among various levels of treatments. 3. The regressive equation was derived from the relationship between treatment levels and tobacco leaf yield. The most desirable treatment level for the maximum yield was estimated as the 2.87 times as much as the treatment level of phosphate and potasium fertilizers of standard plot. 4. By increased application of phosphate and potash fertilizers, the contents of $P_2O_5$ and $K_2O$ in the tobacco leaf became greater while the content of nicotine was decreased. Thus, a negative correlation between fertilizer application and nicotine content has been observed.

• Korean Journal of Crystallography
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• v.12 no.3
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• pp.145-149
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• 2001

The hydrothermal reaction between zinc(II) nitrate Zn₃(PO₄)₂(H₂O) and potassium phosphate dibasic (K₂HPO₄) in the presence of pyrazine gave a three-dimensional zinc-phosphate coordination polymer with an empirical formula of Zn₃(PO₄)₂(H₂O) (1). Compound 1 was characterized by IR spectroscopy, and X-ray diffraction. Crystallographic data for 1: monoclinic space group. P2₁/c, a=8.970(1)Å, b=4.901(1)Å, c=16.759(3)Å, β=94.98(2)°, Z=4, R(wR₂)=0.0332(0.0927).