• Applied Biological Chemistry
• /
• v.34 no.1
• /
• pp.54-60
• /
• 1991

Serratia marcescens CK-3, decomposing chitin which is a mar component of cell wall in phyitopathogenic fungi, was isolated from the continuous cropping rhizosphere of pepper and cucumber and its enzymatic property was examined. S. marcescens CK-3 was found tn have an tagonistic effects against, Fusarium axysporum and Rhizoctonia solani and to have complex enzyme system such as chitinase, laminarinase, and proteinase. The preferable composition of the medium for production of chitinase was fond and was as follows : colloidal chitin 1.5%, tryptone 0.5%, glucose 1.0%, peptone 0.2%, $MgSO_4{\cdot}7H_2O\;0.1%,\;K_2HPO_4\;0.1%,\;and\;NaCl\;0.1%$(w/v), pH 6.8. The maximum enzyme production was observed after culture of 72 hours at $30^{\circ}C$ using a medium containing the above chemical composition. The optimal pH and temperature for in vitro activity of chitinase from S. marcescens CK-3 were pH 7.5 and $50^{\circ}C$, respectively. The enzyme activity in-creased by metal ions such as$Ag^+$ and $Mn^{++}$.

• Journal of the Korean Chemical Society
• /
• v.33 no.5
• /
• pp.516-521
• /
• 1989

Reaction between the $N_2O_2-type$ tetradentate ligand, ethylenediamine-N,N'-di-S-${\alpha}$-isobutylacetic acid (SS-emiba) and $RhCl_3{\cdot}3H_2O$ has yielded ${\Delta}-s-cis-\;and\;{\wedge}-uns-cis-[Rh(SS-eniba)Cl_2]-$. ${\Delta}-s-cis-[Rh(SS-eniba)Cl_2]^-$ has been utilized to react with S-methyl-L-cystcine(Smc) to give ${\Delta}-s-cis-[Rh(SS-eniba(Smc)]^+$. The oxidation of ${\Delta}-s-cis-[Rh(SS-eniba(Smc)]^+$ using $H_2O_2$ has produced ${\Delta}-s-cis-[Rh(SS-eniba)(Smc-o)]^+$, in which the coordinated sulfur has been converted into the sulfoxide group. In a separate series of experiments the S-methyl-L-cysteine is oxidized by $H_2O_2$ to give S-methyl-L-cysteine sulfoxide, which is then coordinated to ${\Delta}-s-cis-[Rh(SS-eniba)Cl2]^-$ to make the standard complet of ${\Delta}-s-cis-[Rh(SS-eniba)(Sme-o)]+$ for comparison with the complex obtained from the oxidation of ${\Delta}-s-cis-[Rh(SS-eniba)(Smc)]^+\;by\;H_2O_2.$

• Journal of the Korean Chemical Society
• /
• v.36 no.4
• /
• pp.540-545
• /
• 1992

Kinetics and mechanism on the solvent extraction of nickel(Ⅱ) with 8-hydroxyquinoline (HOx) was studied spectrophotometrically. Absorbance variation was measured by changing the 8-hydroxyquinoline concentration in the chloroform organic phase and the pH values in the aquous phase. By analyzing absorbance data the reaction rate was found to be the first order for 8-hydroxyquinoline concentration and the inverse first one for [H$^+$]. Therefore the rate determining step of the extraction reaction is the formation of the one-to-one metal chelate NiOx$^+$ and the rate equation is as follows; -d[Ni$^{2+}$]/dt = k[Ni$^{2+}$][Ox$^-$] = k'[Ni$^{2+}$][HOx]$_0$/[H$^+$]. The value of k' was evaluated from the slope of plot of log [Ni$^{2+}$]$_0$/[Ni$^{2+}$]$_t$ versus time and the rate constant k was calculated according to the equation k' = k ${\times}$ K$_{HOx}$ / K$_{D,HOx}$. From the temperature dependence of the extraction rate, the activation energy E$_a$ = 6.26 kcal/mol is calculated, and activation parameters, ${\Delta}$G$^{\neq}_{298}$ = 6.59 kcal/mol, ${\Delta}$H$^{\neq}_{298}$ = 5.68 kcal/mol, ${\Delta}$S$^{\neq}_{298}$ = -3.09 eu/mol are estimated.

• Journal of the Korean Chemical Society
• /
• v.27 no.2
• /
• pp.83-94
• /
• 1983

The effects of cis and trans configurations of ligands for $[M(II)O_3N_3]$ and $[Ni(II) O_2N_4]$ type complexes [M(II) = Co(III), Ni(II) and Cu(II)] on the calculated dipole moments have been investigated, adpoting the eigenvectors of EHT calculation. The calculated dipole moments for cis complexes are higher than those of trans complexes. The calculated dipole moments for the octahedral trans $[Co(III)O_3N_3]$ type complex fall in the range of experimental values. However the calculated dipole moments for cis $[Ni(II) O_2N_4]$ type complexes fall in the range of the experimental values. These results predicts the trans structure for $[Co(III)O_3N_3]$ and $[Ni(II) O_2N_4]$ type complexes. Those structures are in agreement with the experimental one (Three bidentate (O-N) ligands in $[M(II)O_3N_3]$ type complexes coordinate to the metal ion and two tridentate (O-N-N) ligands in [Ni(II)O2N4] type complexes coordinate to Ni(II) ion).

• Journal of Conservation Science
• /
• v.28 no.1
• /
• pp.53-62
• /
• 2012

The archival objects are tangible evidence related to the public service. They are unique and offer information representing the specific events, time or person. The archival objects as modern cultural heritage do not have the guideline to classify, manage and conserve them. Especially, it is difficult to apply general conservation process for burial artifacts, because there are few study example of conservation for metal archival objects and they have complex administrative value. We tried to find suitable material and application method for consolidation of copper alloy archival object. We choose three kinds of wax and acrylic resin for burial artifacts and had done comparative analysis of their characterizations following kinds and coating methods. As a result of evaluation by several surface analysis such as optical microscope, measuring film thickness, adhesive strength, contact angle and yellowing test, acrylic resin can use to archival objects of copper alloy, effectively but the method of heating after dip-coating with Wax B used before can get best effect of consolidation.

• Journal of Conservation Science
• /
• v.32 no.4
• /
• pp.491-500
• /
• 2016

Fog is atmospheric in which tiny drops of water vapor are suspended in the air near the ground. Its form, occurrence, etc., change according to the temperature, relative humidity, wind and geographical features of the space around it. In particular, fog tends to occur near a source of water because of temperature and relative humidity difference. These days, climate change is increasingly affecting the occurrence of fog. Therefore the purpose of this study was to investigate how fog affects materials that are part of our cultural properties through outdoor exposure tests and artificial degradation. The degradation evaluation of materials as a function of fog occurrence frequency, showed that the color of metals changed noticeably, whereas dyed silk and Dancheong showed degradation on the surface and color differences but no particular tendencies. Therefore, damage prediction by color differences as a function of fog occurrence frequency was based on metal samples, which showed constant color differences. Through a comparison of the predictive value and color difference by outdoor exposure, the accuracy and applicability of the damage prediction formula was confirmed. If a more complex damage prediction formula is created, it is expected that prediction of the degree of material damage in the field would be possible.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.19 no.2
• /
• pp.47-62
• /
• 2016

An integrated database(DB) system was developed to manage the marine geological data and geophysical data acquired from around the Korean peninsula from 2009 to 2013. Geological data such as size analysis data, columnar section images, X-ray images, heavy metal data, and organic carbon data of sediment samples, were collected in the form of text files, excel files, PDF files and image files. Geophysical data such as seismic data, magnetic data, and gravity data were gathered in the form of SEG-Y binary files, image files and text files. We collected scientific data from research projects funded by the Ministry of Oceans and Fisheries, data produced by domestic marine organizations, and public data provided by foreign organizations. All the collected data were validated manually and stored in the archive DB according to data processing procedures. A geographic information system was developed to manage the spatial information and provide data effectively using the map interface. Geographic information system(GIS) software was used to import the position data from text files, manipulate spatial data, and produce shape files. A GIS DB was set up using the Oracle database system and ArcGIS spatial data engine. A client/server GIS application was developed to support data search, data provision, and visualization of scientific data. It provided complex search functions and on-the-fly visualization using ChartFX and specially developed programs. The system is currently being maintained and newly collected data is added to the DB system every year.

• Journal of the Korean Chemical Society
• /
• v.14 no.1
• /
• pp.65-74
• /
• 1970

Formation of the complexes of alkaline earths with citrate ions in aqueous, acetone-water and ethanol-water solutions was studied at room temperature by the equilibrium exchange technique. This technique involved the measurements of distribution of radioactivity between cation exchange resin and solution phase after the radioactive metal ions were equilibriated with the cation exchange resin in the presence of citrate ions ($Cit^{3-}$) of varying concentrations. The pH of the solutions was controlled to 7.2-7.5, and the ionic strength of the solutions was kept at 0.10-0.12. The present study revealed that both barium and strontium ions formed the one to one citrate complexes, $[M Cit]^-$ in all solvent systems examined. It was also observed that calcium ions formed the one to one citrate complex in aqueous solution. In acetone-water and ethanol-water solutions, however, calcium ions were observed to form both one to one and one to two complexes, $[Ca Cit]^-$ and $[Ca\;Cit_2]^{4-}$. The results of the present study indicated also that relative stabilities of the complexes increased in the order; $Ba^{++}\;<\;Sr^{++}\;<\;Ca^{++}$, and in the order of increasing concentration of the organic components in the mixed solvent systems.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2008.06a
• /
• pp.169-169
• /
• 2008

To keep pace with scaling trends of CMOS technologies, high-k metal oxides are to be introduced. Due to their high permittivity, high-k materials can achieve the required capacitance with stacks of higher physical thickness to reduce the leakage current through the scaled gate oxide, which make it become much more promising materials to instead of $SiO_2$. As further studying on high-k, an understanding of the relation between the etch characteristics of high-k dielectric materials and plasma properties is required for the low damaged removal process to match standard processing procedure. There are some reports on the dry etching of different high-k materials in ICP and ECR plasma with various plasma parameters, such as different gas combinations ($Cl_2$, $Cl_2/BCl_3$, $Cl_2$/Ar, $SF_6$/Ar, and $CH_4/H_2$/Ar etc). Understanding of the complex behavior of particles at surfaces requires detailed knowledge of both macroscopic and microscopic processes that take place; also certain processes depend critically on temperature and gas pressure. The choice of $BCl_3$ as the chemically active gas results from the fact that it is widely used for the etching o the materials covered by the native oxides due to the effective extraction of oxygen in the form of $BCl_xO_y$ compounds. In this study, the surface reactions and the etch rate of $Al_2O_3$ films in $BCl_3/Cl_2$/Ar plasma were investigated in an inductively coupled plasma(ICP) reactor in terms of the gas mixing ratio, RF power, DC bias and chamber pressure. The variations of relative volume densities for the particles were measured with optical emission spectroscopy (OES). The surface imagination was measured by AFM and SEM. The chemical states of film was investigated using X-ray photoelectron spectroscopy (XPS), which confirmed the existence of nonvolatile etch byproducts.

• Journal of the Korean Chemical Society
• /
• v.55 no.1
• /
• pp.28-37
• /
• 2011

Spectroscopic (infrared, electronic and $1^H$-NMR), elemental analyses CHN, molar conductivity, thermogravimetric analyses (TGA/DTG) and biological studies, of both benzanthrone derivatives 3-N-2-hydroxy ethylamine benzanthrone (HEAB) and 3-N-2-amino ethylamine benzanthrone (AEAB) with Cu(II), Co(II) and Ni(II) chlorides were discussed herein. Based on the above studies, HEAB ligand was suggested to be coordinated to each metal ions via hydroxo and amino groups to form [Cu(HEAB)$(Cl)_2$].$2H_2O$, [Co(HEAB)$(Cl)_2(H_2O)_2$].$8H_2O$ and [Ni(HEAB)$(Cl)_2(H_2O)_2$].$7H_2O$ coordinated complex. On the other hand, AEAB has an octahedral coordinated feature with formulas [Cu(AEAB)$(Cl)_2(H_2O)_2$].$2H_2O$, [Co(AEAB)$(Cl)_2(H_2O)_2$].$4H_2O$ and [Ni(AEAB)$(Cl)_2(H_2O)_2$]. $6H_2O$. The molar conductance values at $25{\circ}C$ for all complexes in DMF are slightly higher than free ligands; this supported the presence of chloride ions inside the coordination sphere. Both benzanthrone ligands and their complexes have been screened against different kinds of bacteria.