• Journal of the Korean Chemical Society
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• v.25 no.5
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• pp.311-317
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• 1981

A new nickel(II) compound, $Ni(CH_2SiMe_3)_2((C_6H_5)_2PCH_2CH_2P(C_6H_5)_2)$, 1, has been prepared by the reaction of $NiCl_2((C_6H_5)_2PCH_2CH_2P(C_6H_5)_2)$ with $Me_3SiCH_2Li$. The compound, 1, is stable under nitrogen at room temperature both in solution and in the solid state. Thermal decomposition of 1 in solution or in the solid produces the reductive coupling product, $Me_3SiCH_2CH_2SiMe_3$ which is also afforded by the reactions of 1 with CO and $O_2$ at room temperature, and with $(C_6H_5)_2PCH_2CH_2P(C_6H_5)_2$ at 80${\circ}$C.

• Journal of the Korean Chemical Society
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• v.39 no.7
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• pp.552-558
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• 1995

The tetranuclear complexes, $X_2[M_{O4}O_12{R'C(NH_2)NO}_2](X= n-Bu_4N^+$, $R'=(CH_3)_2CH$, $CH_3CH_2CH_2$, $CH_3SCH_2$; $X=(CH_3)_2CHC(=NH_2)NH_2^+$, $R'=(CH_3)_2CH$; $X = CH_3CH_2CH_2C(=NH_2)NH_2^+$, $R'=CH_3_CH_2CH_2$; $X=CH_3SCH_2C(=NH_2)NH_2^+$, $R'=CH_3SCH_2)$ have been synthesized by the reactions of monomeric and polynuclear complexes with isobutyl-, butyl- and thiomethylacetamidoxime. The prepared complexes were identified by elemental analysis, infrared, $^1H$ NMR and $^{13}C$ NMR spectroscopy. The structure of complex ${(CH_3)_2CHC(NH_2)_2}_2[M_{O4}O_{12}{(CH_3)_2CHC(NH_2)NO}_2]$ was determined by X-ray single crystal diffraction. Crystal data are follows: Monoclinic, $P2_{1/c}$, $a=10.168(3){\AA}$, $b=11.768(1){\AA}$, $c=13.557(1){\AA}$, ${\beta}=102.08(1)^{\circ}$, $V=1586.2(5){\AA}^3$, Z=2, final R=0.026 for 2951($F_0>3s(F_0)$). This complex is composed of a planar cyclic $[Mo_4({\mu}-O)_4]$ and two ${\mu}_4$-amidoximate.

• Bulletin of the Korean Chemical Society
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• v.18 no.3
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• pp.311-316
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• 1997

The synthesis and characterization of the mononuclear group 13 heterocyclic carboxaldehyde methyldithiocarbazate complexes Me2M[NC5H4CRNNC(S)SCH3] (M=Al, R=H(1); M=Ga, R=H(2); M=Al, R=CH3(3); M-Ga, R=CH3(4); M=In, R=CH3(5)) are described. Compounds 1-5 were prepared by the reaction of MMe3 (M=Al, Ga, In) with 2-formy or 2-acetylpyridine-S-methyldithiocarbazate in toluene. These compounds 1-5 have been characterized by microanalysis, NMR (1H, 13C) spectroscopy, mass spectra, and single-crystal X-ray diffraction. X-ray single-crystal diffraction analyses reveal that 4-5 are mononuclear metal compounds with coordination number of 5 and N,N,S coordination mode.

• Journal of the Korean Chemical Society
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• v.39 no.6
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• pp.434-439
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• 1995

Six-coordinate molybdenum(Ⅴ)-oxo complexes, (R4N)[MoO(NCS)2L](R=CH3, C2H5, n-C4, H9) with S-methyl-3-(2-hydroxy-x-phenyl)methylenedithiocarbazate(L1: x=5-H) and its derivatives (L2:x=5-CH3, L3: x=3-CH3O, L4: x=5,6-C4H4 and L5: x=5-NO2) have been synthesized and the structural, spectral and electrochemical properties of the complexes have been characterized by elemental analysis, molar conductivity, UV-Vis, IR, 1H NMR, and CV (cyclic voltammetry).

• Bulletin of the Korean Chemical Society
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• v.20 no.11
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• pp.1295-1298
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• 1999

Novel platinum(IV) complexes with asymmetric chiral diamine ligands cis,cis,trans-A2PtCl2(X)2 (X = OH, OCOCH3, OCOC2H5, A2 =NH2CH(CH3)CH2NH(c-C6H11)(apcha), NH2CH(CH3)CH2NH(c-C5H9)(apcpa)) have been prepared. One of the platinum(IV) complexes, (apcpa)PtCl2(OCOC2H5)2(6), was subjected to X-ray crystallographic analysis. The crystal structure of (apcpa)PtCl2(OCOC2H5)2 (monoclinic, P21 (No. 4), a = 9.1391(1), b = 22.2517(1), c = 10.0687(1)Å, β= 109.105(1)。 , V = 1934.80(3)Å3 , Z = 4, R1 = 0.0532) exhibits that the platinum atom achieves a typical octahedral arrangement with two nitrogen atoms in cis positions and two carboxylato group in trans positions. The spectroscopic data disclose that these platinum(IV) complexes are stable and their molecular structures are retained in aqueous solution. The title complexes are highly cytotoxic in vitro but do not exhibit oral anticancer activity in vivo.

• Journal of the Korean Society for Marine Environment & Energy
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• v.13 no.3
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• pp.165-173
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• 2010

A cloud detection method is introduced to improve the reliability of NOAA/AVHRR Sea Surface Temperature (SST) data processed during the daytime and nighttime in the TeraScan System. In daytime, the channels 2 and 4 are used to detect a cloud using the three tests, which are spatial uniformity tests of brightness temperature (infrared channel 4) and channel 2 albedo, and reflectivity threshold test for visible channel 2. Meanwhile, the nighttime cloud detection tests are performed by using the channels 3 and 4, because the channel 2 data are not available in nighttime. This process include the dual channel brightness temperature difference (ch3 - ch4) and infrared channel brightness temperature threshold tests. For a comparison of daytime and nighttime SST images, two data used here are obtained at 0:28 (UTC) and 21:00 (UTC) on May 13, 2009. 6 parameters was tested to understand the factors that affect a cloud masking in and around Korean Peninsula. In daytime, the thresholds for ch2_max cover a range 3 through 8, and ch4_delta and ch2_delta are fixed on 5 and 2, respectively. In nighttime, the threshold range of ch3_minus_ch4 is from -1 to 0, and ch4_delta and min_ch4_temp have the fixed thresholds with 3.5 and 0, respectively. It is acceptable that the resulted images represent a reliability of SST according to the change of cloud masking area by each level. In the future, the accuracy of SST will be verified, and an assimilation method for SST data should be tested for a reliability improvement considering an atmospheric characteristic of research area around Korean Peninsula.

• Journal of Veterinary Clinics
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• v.19 no.2
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• pp.165-173
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• 2002

The purpose of this study was to evaluate the effect of chitosan-calcium sulfate mixture on early bony consolidation in osteodistracted dogs. The experimental group was divided into 3 groups: saline group(Control), chitosan group(Group CH) and chitosan-calcium sulfate mixture group(Group CH+CS). Four dogs were allocated to each group and classified into B week observation subgroups and 5 week observation subgroups, respectively. Two dogs were allocated to each subgroup. The lateral surface of the left mandibular body was exposed in the subperiosteal plane and vertical osteotomy was carried out on the mandibular body. An external distraction device was applied to the mandibular body. Mandibular distraction was started 5 days after the osteotomy at a rate of 1 m per day for a total of 10 w distraction for 10 days. After completion of distraction, chitosan, chitosan-calcium sulfate and saline were injected into the distracted zone of the group CH, group CH+CS and control. The external device was left in place for 3 or 5 weeks to allow for bony consolidation. Serial radiographs were carried out every week. Two dogs of each group, six dogs in total, were sacrificed at 3 weeks, and the other six dogs at 5 week after distraction. Bone specimens of the distracted mandibles were taken for histologic examination. New bone was not noted in the distracted zone of 3 week observation subgroups in the control and group CH. However, new bone was developed in the group CH+CS with a narrow fibrous interzone in the area of the distracted zone. While osteogenesis was mild in the margin of the distracted Bone of 5 week observation subgroup in the control, new bone was noted much in the group CH and group CH+CS. However, osteogenesis was noted more significantly in the group CH+CS than that of group CH. In conclusion, chitosan-calcium sulfate mixture was more effective on early bony consolidation in distraction osteogenesis

• Korean Journal of Materials Research
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• v.21 no.4
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• pp.207-211
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• 2011

Ni 8 wt.%-doped tin oxide ($SnO_2$) thick films were fabricated into gas sensors by the method of screen printing onto alumina substrates. The particle size of $SnO_2$ was controlled by changing the ball-mill time between 0~120 h. The structural and morphological properties of these thick films were investigated using X-ray diffraction and scanning electron microscopy. The structural properties of $SnO_2$ powders showed a tetragonal phase with (110) dominant orientation. The particle size of the $SnO_2$:Ni powders after ball-mill of 120 h was about 0.05 ${\mu}m$. The gas sensitivity (S = Rg/Ra) to 5 ppm $CH_4$ gas and $CH_3CH_2CH_3$ gas was measured at room temperature by comparing the resistance in air (Ra) with that of the target gases (Rg). The sensitivity of the $SnO_2$ gas sensors was enhanced by increasing the ball-mill time. There was an association between the sensitivity of both the $CH_4$ gas and the $CH_3CH_2CH_3$ gas and the particle size of the $SnO_2$. $SnO_2$ gas sensors prepared by 72 h ball-mill showed a sensitivity of about 13 to 5 ppm $CH_4$ gas and $CH_3CH_2CH_3$ gas. The response time of the $SnO_2$:Ni gas sensors to the $CH_4$ gas was about 20 seconds.

• Polymer(Korea)
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• v.32 no.3
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• pp.239-245
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• 2008

Block copolymers of the general formula $[(-CO-R'-CO-HN-Ar-NH-CO-R'-CO)_xNH(CH_2)_3-(Me_2SiO)_y(CH_2)_3NH_2]_n$, [n=18.00 to 1175.0] where $R'=CH_2CH(CH_2GeCl_3)$;$CH_2CHGeCl_3CH_2$; and $Ar=-C_6H_4$;$-(o.CH_3C_6H_4)_2$;$-o.CH_3OC_6H_4)_2$;$-(o.CH_3C_6H_4)$ were prepared by a polycondensation reaction of polyamide containing a pendant trichlorogermyl group and terminal acid chloride $Cl(-CO-R'-CO-NH-Ar-NH-CO-R'-CO-)_xCl$ with aminopropyl-terminated polydimethylsiloxane $H_2N(CH_2)_3(Me_2SiO)_y-(CH_2)_3NH_2]$, (PDMS). These polymers were characterized by elemental analysis, $T_g$, FT-IR, $^1H$-NMR, solid state $^{13}C$-NMR, and molecular weight determination. The thermal stability of these copolymers was examined using thermal analysis techniques, such as TGA and DSC. Their molecular weights as determined by laser light scattering technique ranged $5.13{\times}10^5$ to $331{\times}10^5\;g/mol$. These polymers display their $T_g$ in the range of 337 to $393^{\circ}C$ with an average decomposition temperature at $582^{\circ}C$.

• Journal of the Korean Ceramic Society
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• v.40 no.8
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• pp.758-764
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• 2003

The cylindrical ${\gamma}$-alumina pellets were prepared by forming, hydration, drying and calcination after mixing amorphous alumina and pore generating agent with water. Concentration of Fe(NO$_3$)$_3$ㆍ9$H_2O$ that was catalyst precursor was fixed and made mixing solution that changed concentration of $CH_3$COOH in range of 2.5~20%, and here ${\gamma}$-alumina pellets were immerged and were hydrothermaly treated for 3 h at $200^{\circ}C$. And then we investigated creation and change of crystal, pore characteristics, $N_2$ adsorption and desorption isotherms, changes of acid site and mechanical strengths etc. According to the concentration of $CH_3$COOH, the crystals grew to acicular shape of 0.5~2${\mu}m$ length, and crystal structure showed the pseudo-boehmite structure. When hydrothermaly treated in 10% $CH_3$COOH solution, pore volume between 100~1000 $\AA$ was highest by 0.86 cc/g, and width of hysteresis curved line due to $N_2$ adsorption/desorption appeared as was smallest. When concentration of $CH_3$COOH was in range of 5~15%, new C-H functional groups were formed. Mechanical strength of pellets was highest by 1.35 MPa when $CH_3$COOH concentration was 2.5%.