• Bulletin of the Korean Chemical Society
• /
• v.28 no.8
• /
• pp.1299-1304
• /
• 2007

New sulfur functionalized cyclopentadiene ligands, 1-[2-(thioanisole)]-2,5-dimethylcyclopentadiene (3), 1-[2- (thioanisole)]-2,3,5-trimethylcyclopentadiene (4), and 1-[2-(thioanisole)]-2,3,4,5-tetramethylcyclopentadiene (5), were prepared. In these ligands, the S-donor atom is connected to a cyclopentadiene ring by a rigid phenylene spacer. CpCo(III)-diiodo half-sandwich complexes (6-8) were obtained from reaction the ligands (3- 5) with Co2(CO)8, followed by treatment of I2. Substitution reaction of CpCo(III)-diiodo complexes with MeLi yielded the corresponding CpCo(III)-dimethyl complexes (9-11). Further transformation to the corresponding cationic cobalt complexes (12-14) were achieved by reaction of the CpCo(III)-dimethyl complexes with HB(ArF)4·2Et2O and trapping with CD3CN. The new sulfur functionalized cyclopentadiene ligands having a rigid phenylene spacer and the corresponding cobalt complexes were characterized by 1H, 13C and 19F NMR spectroscopy. The diiodo Complex 6 was also characterized by a single crystal X-ray diffraction method.

• Korean Journal of Materials Research
• /
• v.16 no.8
• /
• pp.473-478
• /
• 2006

The coherent interface energies and misfit strain energies of Fe/XN (X=Ti, Zr, Hf) systems were calculated by first principles method. The interface energies in Fe/TiN, Fe/ZrN and Fe/HfN systems were 0.343, 0.114, and 0.030 $J/m^2$, respectively. Influence of bond energy was estimated using the discrete lattice plane/nearest neighbor broken bond(DLP/NNBB) model. It was found that the dependence of interface energy on the type of nitride was closely related to changes of the bond energies between Fe, X and N atoms before and after formation of the Fe/XN interfaces. The misfit strain energies in Fe/TiN, Fe/ZrN, and Fe/HfN systems were 0.239, 1.229, and 0.955 eV per 16 atoms(Fe; 8 atoms and XN; 8 atoms). More misfit strain energy was generated as the difference of lattice parameters between the bulk Fe and the bulk XNs increased.

• Korean Journal of Crystallography
• /
• v.13 no.2
• /
• pp.86-90
• /
• 2002

The structure of N-(Diphenylmethylene)aminomethylphosphonate has been determined by X-ray diffraction methods. The crystal system is triclinic, space group P(equation omitted), unit cell constants, a＝8.967(2) (equation omitted), b＝9.309(2) (equation omitted), c＝ 10.981(2) (equation omitted), α＝101.42(2)°, β＝92.22(2)°, γ＝92.23(2)°, V=896.8(3) (equation omitted), T＝296 K, Z＝2, D/sub c/＝1.227 Mgm/sup -3/. The intensity data were collected on an Enraf-Nonius CAD-4 Diffractometer with graphite monochromated MoKα radiation (λ＝0.7107(equation omitted)). The molecular structure was solved by direct methods and refined by full-matrix least-squares to a final R＝7.3% for 979 unique observed F/sub o/>4σ(F/sub o/) refections and 209 parameters.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.10 no.6
• /
• pp.84-90
• /
• 2011

In this paper, a dual-band pseudo-combline narrow bandpass filter is proposed. The proposed bandpass filter adopts the open resonant stubs and the proposed bandpass filter can be used for ITS(Intelligent Transport System) and X-band satellite systems application. The proposed bandpass filter has the insertion and return losses of 1.72 dB and 15.5 dB at the bandwidth of 3.6 % and center frequency of 5.8 GHz, respectively. Also, the second operating frequency band for insertion and return losses are 1.92 dB and 16.3 dB at the bandwidth of 3% and center frequency of 8.5 GHz, respectively.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.25 no.3B
• /
• pp.541-548
• /
• 2000

In the MPEG-4 standardization phase, many methods for coding the irregular shaped VOP (video object Plane) have been researched. Texture coding is one of interesting research items in the MPEG-4. There are the Low pass extrapolation (LPE) padding, the shape adaptive DCT (SA-DCT), and the Extension-Interpolation (EI)/2D-DCT proposed in [1] as texture coding methods. the EI/2D-DCT is the method extending and interpolating luminance values from and Arbitrarily Shaped (AS) image segment into an 8 x 8 block and transforming the extended and interpolated luminance values by the 8x8 DCT. although the EI/2D-DCT and the SA-DCT work well in coding the As image segments. they are degraded since they use one-dimensional (1-D) methods such as the 1D-EI and the 1D-DCT in the two-dimensional (2-D) space. in this paper, we analyze the performance of the EI/2D-DCTand propose a new non-symmetric sig-sag scanning method, which non-symmetrically scans the quantized coefficients in the DCT domain to improve the EI/2D-DCT.

• Journal of Preventive Medicine and Public Health
• /
• v.28 no.1 s.49
• /
• pp.73-84
• /
• 1995

This study was conducted to measure the lead level in the blood, scalp hair and toenail of the elementary schoolchildren and assess the relationship among those samples. Lead concentration of the blood, scalp hair and toenail was measured for 100(male 50, female 50) fourth grade elementary schoolchildren in Taegu city. The mean lead level in the blood, scalp hair and toenail was $6.00{\pm}2.44{\mu}g/dl,\;6.68{\pm}3.54{\mu}g/g,\;and\;7.33{\pm}3.18{\mu}g/g. The mean lead level in the blood of schoolboys was $6.43{\pm}2.77{\mu}g/dl$, and that of schoolgirls was $5.59{\pm}2.01{\mu}g/dl$. The mean lead level in the scalp hair of schoolboys was $7.66{\pm}2.97{\mu}g/g$ and that of schoolgirls was $6.88{\pm}3.54{\mu}g/g$. The mean lead level in the toenail of schoolboys was $8.19{\pm}3.5{\mu}g/g$ and that of schoolgirls was $6.47{\pm}2.52{\mu}g/g$ and their difference was statistically significant. In schoolboys, the correlation coefficient between the lead level in the blood and scalp hair was 0.4909, and the data were fitted best by the regression equation Y = 0.5255X+4. 2810, where Y and X are scalp hair and blood concentration. In schoolgirls the correlation coefficient between the lead level in the blood and scalp hair was 0.3778, and the data were fitted best by the regression equation Y = 0.6655X+2.9632, where Y and X are scalp hair and blood concentration. In schoolboys, the correlation coefficient between the lead level in the blood and in the toenail was 0.5533, and the data were fitted best by the regression equation Y = 0.7076X+3. 6472, where Y and X are toenail and blood concentration. In schoolgirls the correlation coefficient between the lead level in the blood and in the toenail was 0.2738, and the data were fitted best by the regression equation Y = 0.3431X+4.5570, where Y and X are toenail and blood concentration In schoolboys, the correlation coefficient between the lead level in the scalp hair and in the toenail, in the schoolboys was 0.4148, and the data were fitted best by the regression equation Y = 0.4956X+4.3986, where Y and X are toenail and scalp hair concentration. In schoolgirls, the correlation coefficient between the lead level in the scalp hair and in the toenail was 0.1159, and the data were fitted best by the regression equation Y = 0.0825X+5. 9214, where Y and X are toenail and scalp hair concentration. Correlation among lead concentration in the blood, scalp hair and toenail of schoolchildren were statistically significant except between scalp hair and toenail in schoolgirls. These finding suggest that blood, scalp hair and toenail can be used as substitutive samples between each others.

• Journal of the Chungcheong Mathematical Society
• /
• v.8 no.1
• /
• pp.105-110
• /
• 1995

Suppose A is a local global ring (with many units) and $T{\subset}A$ is a preordering. Let $a_i{\in}A^*$, $i=1,2,{\cdots},n$ and $a{\in}({\sum}_{i=1}^{l-1}\;a_iT){\cap}A^*$. Then, for any integer l, 1 < l ${\leq}$ n, there exist $x{\in}({\sum}_{i=1}^{l-1}\;a_iT){\cap}A^*$ and $y{\in}({\sum}_{i=l}^n\;a_iT){\cap}A^*$ such that a=x+y.

• Journal of applied mathematics & informatics
• /
• v.8 no.1
• /
• pp.111-128
• /
• 2001

In this paper, we consider the oscillation of the second-order neutral difference equation Δ²(x/sub n/ - px/sub n-r/) + q/sub n/f(x/sub n/ - σ/sub n/) = 0 as well as the oscillatory behavior of the corresponding ordinary difference equation Δ²z/sub n/ + q/sub n/f(R(n,λ)z/sub n/) = 0

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.5 no.3
• /
• pp.238-243
• /
• 1981

An empirical formula for the mass flow rate in natural convection flume above a spherical heated body which is submerged in a finite fluid contained in a tank was determined. The ratio of depth of submergence to diameter of the sphere for which the sphere sensed as infinite medium was found to be bigger than 7. A dimensionless heat transfer correlation for the natural convection from a sphere was determined for Gr.Prq etween 7x10$\^$7/ and 2x10$\^$8/ also.

• Applied Microscopy
• /
• v.8 no.1
• /
• pp.17-22
• /
• 1978

Two cases of Histiocytosis X, a Hand-Schuller-Christian disease and a Letterer-Siwe disease, are,examined light and electron microscopically. Many of the histiocytes without appreciable lipid contained numerous rod-shaped structure identical to Langerhan's granules in the cytoplasm. The significance of this structure was discussed together with review of literature.