• Korea-Australia Rheology Journal
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• v.13 no.2
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• pp.89-95
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• 2001

Effects of particulate size and frictional characteristics were examined on the melting behavior of PP(polypropylene) in a twin screw extruder. Powder and pellet types of PP were used and each component was blended with PE(polyethylene) wax and clay, respectively. It was observed that small size particulates, 1.e. powder systems exhibit accelerated melting behavior; and it was also found that the abrasive auditive acts as an effective agent for fast melting of PP powder. Retardation of melting due to the reduced friction was observed in both types of PP, contrary to the result found in a batch mixer. The tendency observed in variation of torque and exit temperature was explained in terms of frictional effect and length of compacted region formed during evolution of melting.

• The Bulletin of The Korean Astronomical Society
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• v.35 no.1
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• pp.70.1-70.1
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• 2010

We present the far-ultraviolet (FUV) emission line morphologies in the whole region of the supernova remnant G65.3+5.7 using the FIMS/SPEAR data. The morphologies of the C IV ${\lambda}{\lambda}1548$, 1551, $H2{\lambda}1608 $, He II ${\lambda}1640$, and O III] ${\lambda}{\lambda}1661$, 1666 lines appear to correlate clearly with the optical emission line images or the ROSAT X-ray (0.11-0.284 keV) image obtained in some of the previous studies. We found that a foreground dust cloud, resonant scattering, and incompleteness of radiative shocks have made the definite differences between the morphologies of the above FUV emission lines. We also present the FUV spectra and line intensities from a few sub-regions.

• Journal of Microbiology and Biotechnology
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• v.16 no.2
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• pp.212-218
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• 2006

Three out of fourteen Microcystis-dominant cyanobacterial blooms in Central India were found to be toxic to mice ($LD_{50}$ ranging from 35-450 mg bloom dry mass/kg body weight). The liver architecture of the treated mice showed characteristic symptoms of hepatotoxicity relative to the untreated controls, with increased enzyme activities of serum lactate dehydrogenase (LDH), serum glutamate oxaloacetate transaminase (SGOT), alkaline phosphatase (ALP), and serum glutamate pyruvate transaminase (SGPT). RP-HPLC revealed the presence of microcystin-LR, microcystin-RR, and desmethyl microcystin-RR in the given region to maximum amounts of 390, 1,030, and $860{\mu}g/g$ bloom dry weight, respectively, corresponding to a maximum of 2.8 mg/l microcystin-LR in the lake water. Further confirmation of the microcystin variants was conducted using a MALDI-TOF MS analysis.

• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.87-88
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• 2015

We present results of our R-band polarimetry of a bright-rimmed cloud, IC1396A (with BRC 36), associated with the H II region S131 and the cometary globule LDN 1616 to study their magnetic field geometry. The distances of these clouds have been reported to be ~ 750 pc and ~ 450 pc, respectively in the literature. The young open cluster Trumpler 37 in the vicinity of IC1396A and the high mass stars in the Orion belt near L1616 are found to be responsible for the structure of these clouds. We made polarimetry of foreground stars inferred from their distances measured by the Hipparcos satellite to subtract the foreground contribution to the observed polarization results. We discuss the optical polarimetric results and compare our findings with MHD simulations towards BRCs and CGs.

• 전기의세계
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• v.27 no.6
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• pp.49-53
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• 1978

This paper investigates on the electric input characterisitcs of plasma electron beam in H$_{2}$ gas chamber with various pressures, effected by the shape and dimension of hollow screen cathode during electron beam is formed. The result are as follows: (1)Electron beam is formed in the region of positive resistance on the characteristic curve which shows the relation between the voltage and current of electron beam, independent of the shape and dimension of hollow screen cathode. (2)At a given electron beam current, electron beam voltage increases with the decreases of hollow screen cathode length and screen mesh number of it. (3)At a given electron beam current, electron beam voltage increases with the diameters of hollow screen cathode and electron beam hole of it.

• YAKHAK HOEJI
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• v.52 no.3
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• pp.225-231
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• 2008

To clarify effects of the structural changes of Fur protein on the resistance to metronidazole (Mtz), the mutational analysis of structure and function of the protein in Helicobacter pylori (Hp) was undertaken. It was identified that some changes in Hp Fur protein resulted in increase of resistance to Mtz, and other changes resulted in decrease of resistance. Increase of Mtz resistance came from the enzyme's decreased ability of reducing prodrug Mtz to the form of bactericidal agent. Some sites that affects Mtz resistance (i) in Fur's N terminal extension, and (ii) in its central region, which links DNA binding and Fe-binding modules were identified. It was also found that the addition of FLAG tag to Fur's C terminus also significantly impairs Fur function.

• Applied Biological Chemistry
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• v.36 no.6
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• pp.553-556
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• 1993

Soybean nuclear extracts were prepared to examine the expression of SEF3 (soybean embryo factors 3), which binds to the upstream region of soybean ${\beta}-conglycinin$ ${\alpha}'$ subunit gene and is presumed to be a trans-acting factor for the expression of the gene. The relative levels of SEF3 binding activity in nuclear extracts of maturing soybean embryos were determined using the SE3 DNA probe containing two AACCCA hexanucleotides for gel mobility shift assay. The SEF3 activity increased in developing embryos from 16 to 32 days after pollination, whereas the mobility of the SE3-SE3-SEF3 complex decreased. The mobility of the complex was increased by the treatment of nuclear extracts with alkaline phosphatese, which could be inhibited by phosphate. Formation of the SE3-SEF3 complex was not affected by the binding buffer pH between 6.8 and 8.5.

• Transactions of the Korean hydrogen and new energy society
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• v.25 no.1
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• pp.59-71
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• 2014

An experimental study has been conducted to investigate the heat transfer characteristics of laminar syngas/air mixture with 10% hydrogen content impinging normally to a flat plate of cylinder. Effects of impinging distance, Reynolds number and equivalence ratio as major parameters on heat fluxes of stagnation point and radial direction were examined experimentally by the direct photos and data acquisitions from heat flux sensor. In this work, we could find the incurved flame behavior of line shaped inner top-flame in very closed distance between flat plate and burner exit, which has been not reported from general gas-fuels. There were 3 times of maximum and 2 times minimum heat flux of stagnation point with respect to the impinging distance for the investigation of Reynolds number and equivalence ratio effect. It was confirmed that the maximum heat flux of stagnation point in 1'st and 2'nd peaks increased with the increase of the Reynolds number due to the Nusselt number increment. There was a third maximum rise in the heat flux of stagnation point for larger separation distances and this phenomenon was different each for laminar and turbulent condition. The heat transfer characteristics between the stagnation and wall jet region in radial heat flux profiles was investigated by the averaged heat flux value. It has been observed that the values of averaged heat flux traced well with the characteristics of major parameters and the decreasing of averaged heat flux was coincided with the decreasing trend of adiabatic temperature in spite of the same flow condition, especially for impinging distance and equivalence ratio effects.

• Journal of the Korean Chemical Society
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• v.34 no.1
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• pp.29-36
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• 1990

Cholesteryl pentyl carbonate $(C_{33}H_{56}O_3)$ is monoclinic, space group P21, with a = 12.484(3), b = 9.043(3), c = 14.053(3)$\AA$, ${\beta} = 94.12(2)^{\circ}$ and z = 2. The intensity data were measured for the 2969 reflections within sin $\theta/\lambda = 0.52 {\AA}^{-1}$, using an automatic four--circle diffractometer and graphite monochromated Mo-K$\alpha$ radiation. The atomic coordinates from cholesteryl octanoate were used in an initial trial structure and the structure was refined by full-matrix least squares methods. The final R-factor was 0.12 for 1164 observed reflections. The pentyl group has shortened bond lengths due to the high thermal vibrations in this region. Adjacent molecules are related by $2_1$ screw axis so that they are arranged in an antiparallel array, corresponding to the Monolayer Type II packing mode. There are close packings of cholesteryl groups within the monolayers. This packing type is similar to those of cholesteryl hexanoate, octanoate, hexyl carbonate and oleate.

• Journal of Astronomy and Space Sciences
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• v.21 no.4
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• pp.249-262
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• 2004

The variations of the dynamical substructures of NGC 6934 have been investigated by means of performing point spread function stellar photometry and the surface photometry on BV CCD images of NGC 6934. Our results show that overall variations of ellipticity and position angle range in $0.02{\sim}0.08\;and\;-90^{\circ}{\sim}+90^{\circ}$, respectively out to three times the half light radius. The inner ($r_{eff}) substructures of NGC 6934 inferred from the variations of ellipticity and position angle are mainly affected by the bright red giant populations, while the effects of the other giant populations are weaker than those of the bright red giant populations. Horizontal branch populations and faint red giant star populations affect the dynamical substructures of NGC 6934 in the region of $r_h.