• Journal of the Korean Chemical Society
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• v.36 no.2
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• pp.248-254
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• 1992

Bis(phosphine)ruthenium derivatives $({\eta}^5-C_5Me_5)RuCl(PR_3)_2(PR_3=PMe_3,\; PMe_2Ph,\;PEt_3,\;PMePh_2$, 1/2DPPE, 1/2DPPB) (2a${\sim}$2f) have been synthesized by the reaction of $[({\eta}^5-C_5Me_5)RuCl_2]_2$ (1) with excessive phosphine in ethanol. The reaction of complexes $({\eta}^5-C_5Me_5)Ru(PR_3)_2Cl\;with\;NaBH_4$ in ethanol gave the corresponding hydride complexes $({\eta}^5-C_5Me_5)Ru(PR_3)_2H (PR_3=PMe_3, PEt_3, PMePh_2$, 1/2 DPPE, 1/2DPPB) (3a${\sim}$3e). Chloride complexes (2a${\sim}$2f) and hydride complexes (3a${\sim}$3e) were isolated as crystals, which were characterized by IR, $^1H-NMR$ , and elemental analysis.

• Bulletin of the Korean Chemical Society
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• v.1 no.1
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• pp.1-4
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• 1980

During the study of the kinetics of Cl atom reactions by atomic fluorescence method we observed anomalous fluorescence emission for some atomic transitions. Instead of usual decrease of the fluorescence intensity by adding substrate, 1363 A transition $(^2P^{\circ}_{3/2}{\to}^2P_{1/2})$ intensity increased by adding substrate. From the normally behaved fluorescence lines the absolute rate constant for the reaction, Cl + $CH_3Cl{\to}$, was found to be $4.2{\times}10^{-13}$ cc/molecule sec at $20^{\circ}C$.

• Korean Journal of Materials Research
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• v.16 no.9
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• pp.578-583
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• 2006

We studied the physical properties of Ni-Zn ferrites by adding different chemicals such as $SO_4$, Cl, and $NO_3$. Specimens were prepared by the coprecipitation method and sintered at temperatures $950^{\circ}C,\;1,150^{\circ}C,\;and\;1,350^{\circ}C$, respectively. X-ray diffractions showed a spinel structure and the optical microscopy revealed grain size of 0.3 to 0.6 ${\mu}m$. The optimum sintering temperature to obtain fine, sintered microstructure depended on the additive : Cl and $NO_3\;at\;950^{\circ}C\;and\;SO_4\;at\;1,150^{\circ}C$. According to particle size analysis, higher magnetic permeability and magnetization value were observed with Cl and $NO_3\;than\;SO_4$. As sintering temperature was raised from $950^{\circ}C$ to $1,350^{\circ}C$, the average grain diameter, initial permeability and the magnetic moment also increased.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.4
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• pp.413-419
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• 1995

This study was conducted to find out the suitable NaCl concentration and temperature for investigating the varietal difference of salinity tolerance in Italian ryegrass. Seeds of 20 cultivars including 9 diploid and 11 tetraploid were exposed to eight levels of NaCl concentration ranging from 0 to 350mM under three temperature levels of 15, 20 and $25^{\circ}C$. The NaCl concentration(C50%) inhibited germination of 50% of the viable seeds for the cultivars at 15$^{\circ}C$ was 354mM, and those at 2$0^{\circ}C$ and $25^{\circ}C$ were 342mM and 325mM, respectively. There were significant correlations among C50% at three levels of temperature, and correlation coefficient for C50% between 2$0^{\circ}C$ and 15$^{\circ}C$ was higher than that between $25^{\circ}C$ and 15$^{\circ}C$ or 2$0^{\circ}C$. C50% was positively correlated only with germination speed at 10 days after sowing when the plants were exposed to 350mM NaCl at 2$0^{\circ}C$. For the germination speed at 10 days after sowing in 350mM NaCl at 2$0^{\circ}C$, the cultivars used could be classified into three groups. Wase Aoba, Bettina, E. K -11, Tetrone, Lira Sand, Tetra Florum and Billiken belonged to the tolerant group, and Tuchi Was, Wase Yutaka, Sakura Wase, Magnolia, Limella and Delita were as the semi-susceptible group, and Atalja, Barmultra, Ajax, Liberta, LM-16, Elving and Wilo were as the susceptible group.

• Journal of Positioning, Navigation, and Timing
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• v.4 no.4
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• pp.151-160
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• 2015

GPS L2C signal is a recently added civil signal to L2 frequency and is constructed by time division multiplexing of civil moderate (L2-CM) and civil long (L2-CL) code signals. While the L2-CM code is 20 ms-periodic and modulates satellite navigation message, the L2-CL code is 1.5s-periodic with 767,250 chips long code sequence and carries no data. Therefore, the L2-CL code signal allows receivers to perform a very long coherent integration. However, due to the length of the L2-CL code, the acquisition of the L2-CL code signal may take too long or require too much hardware resources. In this paper, we propose a three-step ultra-fast L2-CL code acquisition (TSCLA) technique for dual band GPS receivers. In the proposed TSCLA technique, a dual band GPS receiver sequentially acquires the coarse/acquisition (C/A) code signal at L1 frequency, the L2-CM code signal, and the L2-CL code signal to minimize mean acquisition time (MAT). The theoretical performance analysis and numerous Monte Carlo simulations show the significant advantage of the proposed TSCLA technique over conventional techniques introduced in the literature.

• Analytical Science and Technology
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• v.16 no.1
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• pp.48-58
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• 2003

The effects of physico-chemical properties of soils on PCBs analysis in Korea was studied Three kinds of extraction solvents(toluene, acetone:hexane, dichloromethane) was selected to apply three different soils. The silicagel, florisil and alumina column cleanup also performed to compare the elution patterns, and three different methods (EPA, Japan, Proposed method in this study) of 62 PCBs also compared the individual peaks recoveries. The solvent average recovery was surveyed the order of toluene, acetone:hexane, dichloromethane as 77.94%, 58.59%, 54.20% for soil A, 53.65%, 80.32%, 68.27% for soil B and 44.52%, 60.35%, 56.36% for soil C, respectively. The average recovery was depended on the soil characters. The highest recoveries of each soil were obtained the toluene for soil A, acetone:hexane for soil B and C. However, the coplanar PCBs was obtained the highest recovery with dichloromethane. Thus, to select the solvent for the analysis of PCBs in solid, the selected compounds have to consider to get good result. The silicagel, florisil, alumina I and alumina II column cleanup process were surveyed the range of 38.73%~98.26%, and the higher chlorinated compounds was obtained the lower recovery compared to the low chlorinated compounds, generally. This results are also consistent with the coplanar PCBs isomers. The compared results of three different countries were obtained the 37.15% for USA, 45.92% for Japan and 44.46% for proposed method in this study.

• Bulletin of the Korean Chemical Society
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• v.23 no.6
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• pp.845-851
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• 2002

The synthesis of the intramolecular donor - stabilized silyl and germyl complexes of the type ($Cab^c.p) MMe_2X$ (2a:M=Si, X=Cl;2b;M= Ge, X=Cl;2e;M=Si,X=H) was achieved by the reaction of $LiCab^c,p$ (1) with $Me_2SiClX$ and $Me_2GeCl_2$ respectively. The intramolecular M←P interacion in 2a-2c is provided by $^1H$, $13^C.$, $31^P$ and $29^Si$ NMR spectroscopy. The salt elimination reactions of dichlorotetramethyldisilane and -digermane with 1 afforded the $bis(\sigma-carboranylphosphino)disilane$ and disgermane [$(Cab^C.P)MMe_2]_2(4a;M$ = Si;4b: M=Ge). The oxidative addition reaction of 4a-4b with $pd_2(dba)_3CHCl_3afforded$ the bis(silyl)-and bis(germyl)-palladium complexes. The chloro-bridged dipalladium complexes were obtained by the reaction of 2a-2b with $pd_2(dba)_3CHCl_3$ The crystal structures of 5a and 7b were determined by X-ray structural studies.

• Bulletin of the Korean Chemical Society
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• v.28 no.10
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• pp.1781-1786
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• 2007

Two copper(II) complexes, [CuL3](ClO4)2 bearing one N-CH2CH2CONH2 group as well as one N-CH2CH2CN group and [CuL4](ClO4)2 bearing two N-CH2CH2CONH2 groups, have been prepared by the selective hydrolysis of [CuL2](ClO4)2 (L2 = C-meso-1,8-bis(cyanoethyl)-5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane). The complex [CuL5](ClO4)2 bearing one N-CH2CH2C(=NH)OCH3 and one N-CH2CH2CN groups has been prepared as the major product from the reaction of [CuL2](ClO4)2 with methanol in the presence of triethylamine. In acidic aqueous solution, the N-CH2CH2C(=NH)OCH3 group of [CuL5](ClO4)2 undergoes hydrolysis to yield [CuL6](ClO4)2 bearing both N-CH2CH2COOCH3 and N-CH2CH2CN groups. The crystal structure of [CuL5](ClO4)2 shows that the complex has a slightly distorted square-pyramidal coordination polyhedron with an apical Cu-N (N-CH2CH2C(=NH)OCH3 group) bond. The apical Cu-N bond distance (2.269(3) A) is ca. 0.06 A longer than the apical Cu-O (N-CH2CH2CONH2 group) bond of [CuL4](ClO4)2. The pendant amide group of [CuL3](ClO4)2 is involved in coordination. The carboxylic ester group of [CuL6](ClO4)2 is also coordinated to the metal ion in various solvents but is removed from the coordination sphere in the solid state.

• Korean journal of food and cookery science
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• v.15 no.6
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• pp.633-638
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• 1999

This study was conducted to investigate the effect of quality preservatives on minimally processed white radish for Kkakttugi, hot radish Kimchi, preparation during storage at $4^{\circ}C$ and $20^{\circ}C$. The firmness of minimally processed white radish decreased during storage at $4^{\circ}C$ and $20^{\circ}C$. However 1% $CaCl_2$ and 2% NaCl+2% sucrose treatments were effective to maintain the firmness of cut radishs. For color, Hunter L values decreased more in the samples stored at $20^{\circ}C$ than at $4^{\circ}C$, while a values showed a slight increase at both storage temperatures. The b values (browning index) showed a notable increase during storage at $4^{\circ}C$ and $20^{\circ}C$. Vitamin C content decreased during storage at both temperatures by 10.4% ~ 95.9%. At both storage temperatures, vitamin C content was highest in the samples treated with 1% NaCl+1% sucrose. For organic acid, while the content of malic acid decreased those of lactic and acetic acid increased during storage.

• Journal of the Korean Chemical Society
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• v.36 no.6
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• pp.872-878
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• 1992

Some vanadium(III) complexes have been prepared by the reaction of VCl3${\cdot}$3MeCN with ligands and characterized by elemental analysis, 1H-NMR, infrared and UV-Visible spectroscopy. 3,5-lutidine(lutd), 8-hydroxyquinoline(oxine), 1,2-phenylenediamine(phda), ethylenediamine(en), and sym-diphenylethylenediamine(dpen) were chosen as coordinating ligands. ${\nu}$(V-Cl) of lutidine complex occurs at 418 $cm^{-1}$ and the other complexes (oxine, phda, en, dpen) occur at 337∼347 $cm^{-1}$. The value of ${\nu}$(V-Cl) indicates that the former complex has trigonal bipyramid structure and the latter complexes have octahedral structure. The ${\nu}$(C${\equiv}$N) of acetonitrile in oxine and phda complexes are characteristically shifted to about 70 $cm^{-1}$ higher frequency compared with that of free ligand (2260 $cm^{-1}$). The ${\delta}$(C${\equiv}$N) is also shifted to about 60 $cm^{-1}$ higher frequency compared with that of free ligand (377 $cm^{-1}$). Finally each vanadium(III) complex showed the following formulation; [$VCl_3(lutd)_2$], [$VCl(oxine)_2$MeCN]$Cl_2$, [$VCl(phda)_2$MeCN]$Cl_2$, [$VCl_2(en)_2$]Cl, [$VCl_2(dpen)_2$]Cl.