• Applied Biological Chemistry
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• v.40 no.4
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• pp.277-282
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• 1997

Acetolactate synthase (ALS) was partially purified from Escherichia coli MF2000/pTATX containing Arabidopsis thaliana ALS gene. The partially purified ALS was examined for its sensitivity toward various modifying reagents such as iodoacetic acid, iodoacetamide, N-ethylmaleimide (NEM), 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB), p-chloromercuribenzoic acid (PCMB), and phenylglyoxal. It was found that PCMB inhibited the enzyme activity most strongly followed by DTNB and NEM. Since iodoacetic acid did not compete with substrate pyruvate, it appeared that cysteine is not involved in the substrate binding site. On the other hand, the substrate protected the enzyme partly from inactivation by phenylglyoxal, which might indicate interaction of arginine residue with the substrate. The partially purified enzyme was inhibited by end products, valine and isoleucine, but not by leucine. However, the ALS modified with PCMB led to potentiate the feedback inhibition of all end products. Additionally, derivatives of pyrimidyl sulfur benzoate, a candidate for a new herbicide for ALS, were examined for their inhibitory effects.

• Progress in Superconductivity
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• v.6 no.1
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• pp.64-68
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• 2004

We fabricated cube-textured Ni and Ni-W alloy substrates for coated conductors and characterized the effects of W addition on microstructure, mechanical strength, and magnetic properties of the substrate. Pure Ni and Ni-(2, 3, 5at.%)W alloys were prepared by plasma arc melting, heavily cold rolled and then annealed at various temperatures of $600-1300^{\circ}C$. The texture was evaluated by pole-figure and orientation distribution function (ODF) analysis. Mechanical properties were investigated by micro Vickers hardness and tension test. Ferromagnetism of the substrate was measured by physical property measurement system (PPMS). It was observed that Ni-W substrates had sharp cube texture, and the full-width at half-maximums (FWHMs) of in-plane texture was $^{\circ}$-5.57$4.42^{\circ}$, which is better than that of pure Ni substrate. In addition cube texture of Ni-W substrates was retained at higher temperature up to $1300^{\circ}C$. Microstructural observation showed that the Ni-W substrates had fine grain size and higher mechanical properties than the pure Ni substrate. These improvements are probably due to strengthening mechanisms such as solid solution hardening and/or grain size strengthening. PPMS analysis showed that addition of W effectively reduced saturation magnetization in applied magnetic field and Curie temperature.

• The Korean Journal of Mycology
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• v.5 no.1
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• pp.1-5
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• 1977

The studies were carried out to examine the influence of the quantities of the rice straw substrate and spawn on the yield in the cultivation of oyster mushroom, Pleurotus ostreatus(Fr.) Quel. using rice straw as growing substrate. The best yield of fresh sporophres was 102 kgs. when the substrate was increased by up to 90 kgs. per 3.3 sq. metre. In case of distributing the spawn over the surface, it was regularly possible to increase the yield using spawn rate of 8kgs. per 3.3 sq. metre and by increasing the ratio of spawn in the substrate, the mycelial growth also made rapid progress.

• Journal of the Korean Institute of Telematics and Electronics
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• v.13 no.3
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• pp.16-21
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• 1976

Transparent eloctroaes of polycrystalline till-oxide films doped with antimony are prepared on the substrate of microscopic cover g1ass by modified spray method and from SnCl4 Solution. Their electrical and optical properties are investigated in relation to the surface temperature of the substrate glass and to antimony concentration in the starting materials. The sheet.resiststrace of the film electrodes and transmittance for incandescent light depen on tile antimony concentration and surface temperature of substrates at the time of making films. The transmittance increases with decrease of sheet resistance of the film. The optimum sheet.resistance was obtianed in the case of the antimony concentration 0.6(%) approximately , and the max. transmittance was 93(%).

• Journal of Sensor Science and Technology
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• v.4 no.2
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• pp.58-63
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• 1995

The effects of substrate temperature, RF power, and $NH_{3}/SiH_{4}$ gas flow ratio on the dielectric constant and optical bandgap of amorphous silicon nitride (a-SiNx:H) thin films prepared by PECVD method using RF glow discharge decomposition of $SiH_{4}$ and $NH_{3}$ gas mixtures have been studied. The dielectric constant and optical bandgap of a-SiNx:H thin films were greatly exchanged as by increasing substrate temperature, RF power, and $NH_{3}/SiH_{4}$ gas flow ratio. The dielectric constant of a-SiNx:H films was increased and optical bandgap of a-SiNx:H films was decreased as the substrate temperature was increased. When the substrate temperature, RF power, gas pressure, $NH_{3}/SiH_{4}$ gas flow ratio, and thickness were $250^{\circ}C$, 20 W, 500 mTorr, 10 and $1500\;{\AA}$, respectively, the dielectric constant, breakdown field and optical bandgap of a-SiNx:H film were 4.3, 1 MV/cm, and 2.9 eV, respectively.

• Journal of the Korean Vacuum Society
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• v.7 no.4
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• pp.361-367
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• 1998

$\alpha$-Sexithiophene ($\alpha$-6T) thin films were deposited by organic molecular beam deposition (OMBD) technique. The $\alpha$-6T was synthesized and purified by the sublimation method. The thin films of the $\alpha$-6T were deposited under various deposition conditions. The effects of deposition rate, substrate temperature, and vacuum pressure on the formation of these films have been studied. The molecular orientation, crystallinity, and surface morphology of $\alpha$-6T films were investigated with angle-resolved UV/visible absorption spectroscopy, X-ray diffractometry (XRD), and atomic force microscopy (AFM). It was found that the crystalline structure of $\alpha$-6T films was monoclinic and independent uppon substrate temperature, deposition rate, and deposition pressure. On the other hand, the $\alpha$-6T molecules in the film deposited at a low deposition rate, higher substrate temperature, and under a high vacuum tended to be aligned perpendicular to the substrate.

• Korean Journal of Materials Research
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• v.5 no.7
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• pp.820-828
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• 1995

Ti-sillcides are formed on an atomically clean Si substrate and its phase transition and surface and interface morphologies are examined depending on the Ti-film thicknesses, deposition temperatures and Si substrate orientations. Ti film thicknesses of 400$\AA$ and 200$\AA$ have been deposited at elevated temperatures from 50$0^{\circ}C$ to 90$0^{\circ}C$ with increments of 10$0^{\circ}C$ on Si(100) and Si(111) Ti-silicides are formed and analyzed with using XRD, SEM, and TEM to verify the phase transition and the surface and interface morphologies. The phase transition from C49 to C54 is observed to occur around $650^{\circ}C$ and examined to show some retardation depending on the substrate orientation and film thickness. This retardation of phase transition is explained by the consideration based on the surface and volume free energies. A rough surface of C49 TiSi$_2$is exhibited because of characteristics of nonuniform diffusion across the interface while the smooth surface and island formation of C54 TiSi$_2$is examined.

• Korean Journal of Materials Research
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• v.22 no.8
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• pp.409-415
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• 2012

$TiO_2$ thin films for high energy density capacitors were prepared by r.f. magnetron sputtering at room temperature. Flexible PET (Polyethylene terephtalate) substrate was used to maintain the structure of the commercial film capacitors. The effects of deposition pressure on the crystallization and electrical properties of $TiO_2$ films were investigated. The crystal structure of $TiO_2$ films deposited on PET substrate at room temperature was unrelated to deposition pressure and showed an amorphous structure unlike that of films on Si substrate. The grain size and surface roughness of films decreased with increasing deposition pressure due to the difference of mean free path. X-ray photoelectron spectroscopy (XPS) analysis revealed the formation of chemically stable $TiO_2$ films. The dielectric constant of $TiO_2$ films was significantly changed with deposition pressure. $TiO_2$ films deposited at low pressure showed high dissipation factor due to the surface microstructure. The dielectric constant and dissipation factor of films deposited at 70 mTorr were found to be 100~120 and 0.83 at 1 kHz, respectively. The temperature dependence of the capacitance of $TiO_2$ films showed the properties of class I ceramic capacitors. $TiO_2$ films deposited at 10~30 mTorr showed dielectric breakdown at applied voltage of 7 V. However, the films of 500~300 nm thickness deposited at 50 and 70 mTorr showed a leakage current of ${\sim}10^{-8}{\sim}10^{-9}$ A at 100 V.

• Journal of the Korean Society for Heat Treatment
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• v.33 no.1
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• pp.20-24
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• 2020

Single crystal diamonds are in great demand in such fields as mechanical, electronic applications and optoelectronics. Large area single crystal diamonds are attracting attention in future industries for mass production and low cost. In this study, hot filament CVD (HFCVD) is used to grow large area single crystal diamond. However, the growth rate of large area single crystal diamond using HFCVD is known to be very low. The goal of this study is to use single crystal diamond substrates in HFCVD with methane-hydrogen gas mixtures to increase the growth rate of single crystal diamond and to optimize the conditions by analysing the effects of deposition conditions for high quality crystallinity. The deposition pressure, the ratio of CH₄/H₂ gas, the substrate temperature and the distance between the filament and the substrate were optimized. The sample used a 4×4 (mm²) size single crystal diamond substrate (100), the CH₄/H₂ gas ratio was fixed at 5%, the substrate temperature was synthesized to about 1000℃. At this time, the deposition pressure was changed to three types of 50, 75, 85 Torr and deposited. Finally, optimization was investigated under pressure conditions to analyse the growth rate and quality of single crystal diamond.

• Journal of the Korean Magnetics Society
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• v.2 no.1
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• pp.22-28
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• 1992

Barium ferrite thin films were reactively deposited with Fe and BaO composite targets by a facing tergects sputtering unit. When thermally oxidized silicon wafers were used as substrates, minimum substrate heating of $750^{\circ}C$ was necessary for the perfect c-axis alignment in barium ferrite films. To lower the critical substrate temperature for the good c-axis alignment, such seed layers as ZnO, ${\alpha}-Fe_{2}O_{3}$ and ${\gamma}-Fe_{2}O_{3}$ were tested. The excellent c-axis algnment of BaM was obtained at a substrate temperature of $600^{\circ}C$ on ZnO seed layer whose (002) plane was parallel to the substrate surface. The magnetic properties of the BaM film showed saturation magnetization of 295 emu/cc, perpendicular coercivity of 1.7 kOe and squareness of 0.75. Optimum deposition rate of $230\;{\AA}/min$ was obtained with the composite target and this was 5 to 20 times higher than those of other investigators with oxide targets.