• 한국해양학회지
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• v.17 no.1
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• pp.19-26
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• 1982

12 or 25 hours continuous observations were made for the variations of nutrients and chlorophyll ${\alpha}$ with tidal cycle at a fixed station located at a mid-channel of the Masan Bay. High nitrate concentrations were observed at the time of low tides whereas high phosphate concentrations at the time of high tides. It is suggested that anoxic bottom waters could also be the possible source of high phosphates in the outer bay. Chlorophyll ${\alpha}$ concentrations were related to the nitrates in April and to the phosphates in June and August. The possible role of growth stimulators in causing the extensive blooms of red tide organisms is suggested.

• Journal of the Korean Chemical Society
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• v.24 no.6
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• pp.463-468
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• 1980

Tris(hydroxyethyl) phosphate, ethylphosphoramidic dichloride, N,N-diethylphosphoramidic dichloride, bis(hydroxyethyl) N-ethylphosphoramidate and bis(hydroxyethyl) N,N-diethylphosphoramidate were synthesized and characterized. Phosphate and phosphoramidates were polymerized with the elimination of ethylene glycol when heated under reduced pressure and they gave no molecular ion peaks in their mass spectra. And also ethylphosphoramidic dichloride gave polymeric products at 180$^{\circ}C$ with the evolution of HCl. IR spectra showed characteristic P=O streching bands in the range of 1,300 to$ 1,200 cm^{-1}.$

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.04a
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• pp.201-204
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• 2004

Immobilization is seen as a promising technology for lead remediation. In a laboratory experiment, immobilization of lead with soluble P was tested as a function of reaction time and P concentration. The P treated with an acidic solution to enhance heavy metal immobilization was worked into the soil, and within 7 days, lead was stabilized. Different molar ratios of soluble phosphates (super-phosphate and KH$_2$PO$_4$) would be considerably effective to accelerate the formation of highly insoluble minerals due to the lack of leachable Pb in the contaminated soil. Although it was demonstrated that the addition of soluble phosphates with an acidic solution significantly reduced available lead in soil up to over 95%, remaining phosphorus in soil matrix might cause a possible groundwater eutrophication in the near future.

• Journal of Korean Society on Water Environment
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• v.23 no.1
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• pp.81-86
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• 2007

This paper describes a study on the role of limestone which might affect the dissolution of phosphates when phosphate containing sediments are put under anaerobic conditions. A small quantity of calcium hydroxy-apatite, alone or mixed with limestone powder, was put in contact with aqueous solution of acetic acid or carbonic acid, and variations of phosphate concentration were determined time dependantly. The results showed that the concentration was remarkably low in the presence of limestone, signifying that the coexistence of limestone suppresses the dissolution of phosphate by organic acid and/or carbonic acid. Separate experiments conducted by developing an anaerobic condition, after mixing lake sediments with dried leaves and limestone, showed that the existence of limestone suppressed the dissolution of phosphate. These results show that the application of limestone might be a useful measure to prevent deterioration of water quality originated from eutrophication by inhibiting the internal loading of P in eutrophic water-bodies.

• 한국해양학회지
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• v.19 no.1
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• pp.89-93
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• 1984

Vertical and horizontal distributions of chemical oceanograthic parameters were measured in Jinhae Bay in July, 1983. On the Masan-Gadeog section, high amounts of dissolved nitrates, ammonia, chlorophylla-a, and particulate carbon and nitrogen were observed in waters with low salinity. In the inner Masan Bay, high concentrations of dissolved ammonia and phosphates were shown. The C/N ratio in the surface waters was higer in the outer bay. Concentrations of dissolved inorganic nitrogen and phosphates in the surface waters seemed to be sufficient for red tides to occur.

• Bulletin of the Korean Chemical Society
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• v.25 no.8
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• pp.1151-1155
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• 2004

The chemosenssor that consists of [$Zn_2$(1,3-bis[bis(2-pyridylmethyl)aminomethyl]benzene)]$^{4+}$ (receptor) and pyrecatechol violet (signaling unit) detects with naked eyes di- and tri-phosphates conjugated to nucleosides or in free forms. The blue color of the aqueous solution (pH 7.0) of the sensor turns to yellow upon exposing to the analytes.

• Korean Journal of Microbiology
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• v.19 no.1
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• pp.23-30
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• 1981

1.Each cells homogenized from Undaria were reacted in reaction micture to persue the phosphate metabolism in Undaria cell. Aliquots of the cells were taken out at the begin-ning and at intervals during the reaction, and analyzed for the content of total-P in various fractions of the cell constituents. 2.The P-contents in fraction of polyphosphate "B" decreased remarkably, while that in fraction of RNA polyphosphate "C" showed slow increase. 3.As well as in Chlorella cells, inorganic phosphates in DNA-P, protein-P, and lipid-P were transferred from polyphosphate, RNA-P turnovered from inorganic phosphate that is in cytoplasm, and RNA polyphosphate complex from polyphosphate, and it was suggested that inorganic phosphates in polyphosphate "B" could transformed into polyphosphate "A" & "C", and polyphosphate "C" into polyphosphate "A".

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2000.11a
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• pp.3-8
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• 2000

Chemical nature of nascent metal surfaces which is one of the important active sources for tribochemical reactions was investigated using a newly developed method. Some enhanced activities were observed. For example, organic compounds chemisorbed on nascent gold surfaces and aromatic compounds decomposed on nascent nickel surfaces resulting in hydrogen evolution. Non-polar compounds such as organic sulfides had a higher chemisorption activity on nascent steel surfaces than polar compounds such as fatty acids and phosphates. Organic sulfides reacted directly with nascent steel surfaces and the surface was covered with metal sulfides. The activity for the chemisorption of organic compounds was closely dependent on the electronic structure of metals. Although benzene chemisorbed very easily on nascent surfaces of transition metals, it did not chemisorb ell nascent surfaces of simple metals. Boundary lubricating behaviors of extreme pressure additives were explained on the bases of the chemical activities of nascent surfaces obtained in this investigation. Under mild conditions, polar compounds such as fatty acids and phosphates were effective for boundary lubrication, because surfaces are covered with oxide layers. On the other hand, sulfides were more effective under severe conditions where the oxide layers were removed and the nascent surfaces were formed.

• Journal of Industrial and Engineering Chemistry
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• v.68
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• pp.220-228
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• 2018

In this study, we found a simple surface biofunctionalization of biphasic calcium phosphate (BCP) based on the high affinity between alendronate and the calcium ions of BCP, and the strong interaction between heparin and bone morphogenic protein-2 (BMP-2). The biofunctionalized BCP did not be precipitated well and display a remarkable enhancement of osteogenic activity of human adipose-derived stem cells by showing increased alkaline phosphatase (ALP), calcium deposition and osteogenic-related genes (i.e., Runx-2, ALP, osteocalcin, and osteopontin), and bone regeneration in the calvarial defect model. Therefore, this simple surface technique can be used to easily functionalize various calcium phosphates.

• Bulletin of the Korean Chemical Society
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• v.18 no.4
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• pp.428-432
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• 1997

The dephosphorylation specificity of protein phosphatase 2A (PP2A), calcineurin (PP2B) and protein phosphatase 2C (PP2C) were studied in vitro using myelin basic protein (MBP) as a model substrate which was fully phosphorylated at multiple sites by protein kinase C (PKC) or cyclic AMP-dependent protein kinase (PKA). In order to determine the site specificity of phosphates in myelin basic protein, the protein was digested with trypsin and the radioactive phosphopeptide fragments were isolated by high performance liquid chromatography (HPLC) on reversed-phase column. Subsequent analysis and/or sequential manual Edman degradation of the purified phosphopeptides revealed that Thr-65 and Ser-115 were most extensively phophorylated by PKA and Ser-55 by PKC. For the dephosphorylation kinetics, the phosphorylated MBP was treated with calcineurin or PP2C with various time intervals and the reaction was terminated by direct tryptic digest. Both Thr-65 and Ser-115 residues were dephosphorylated more rapidly than any other ones by phosphatases. However it can be differentiated further by first-order kinetics that the PP2B dephosphorylated both Thr-65 and Ser-115 with almost same manner, whereas PP2C dephosphorylated somewhat preferentially the Ser-115.