• The Korean Journal of Food And Nutrition
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• v.7 no.1
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• pp.29-35
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• 1994

Photolysis of diazotetracyanocyclopentadiene has been investigated by means of IR and UV-vis spec troscopy in Ar matrix. Parent carbene is produced in low yield and could be detected by UV-vis spectroscopy and IR spectroscopy. The carbene produced from the diazo compound is very photolabile and also decay thermally at temperature as low as 10K. When the diazo compound is photolyzed the Arrhenius plots show a tunneling effect that is not shown as non linearity.

• Proceedings of the Korean Fiber Society Conference
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• 1990.06b
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• pp.67-67
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• 1990

Three non-ionic and two anioinic spin probes, differing in size and substituent, were synthesized. Their mobility in dried nylon 6 film was investicated by the spin probe technique using electron spin resonance spectrometer. When the size of a spin probe was large and the interaction between the probe molecules and polymer chains existed, the mobility of spin probes decreased. From Arrhenius plots of rotational correlation time, one discontinuity point ($T_d$) was determined. The activation energies for rotation below and above $T_d$ were discussed in terms of the mode of probe rotation. Three spin probes could be viewed as azo dyes having a built-in nitroxide radical. Photolysis of them in dimethylformamide and in nylon 6 film was performed by exposure to 254 nm UV light in the presence of air. It was found that dyes having a built-in nitroxide radical showed better photostability than dyes derived from ${\bata}-naphthol$..

• Clean Technology
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• v.18 no.4
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• pp.360-365
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• 2012

With rapid increase in municipal solid waste (MSW) due to the rising economy, solid waste gasification emerges as one of the promising technologies. Separation of the carbon monoxide (CO) and hydrogen ($H_2$) from syngas obtained by gasification of MSW was studied using the polyamide composite membrane. The separation characteristics of the CO and $H_2$ were studied at different gas flow rates and stage cuts. The permeability of CO and $H_2$ along with the selectivity of $H_2$ with respect to CO was obtained. Furthermore, the Arrhenius plots were obtained to estimate the activation energies of CO and $H_2$ permeabilites.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.10
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• pp.763-766
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• 2010

By improving the conducting process of metal source/drain (S/D) in direct contact with the channel, schottky barrier metal-oxide-semiconductor field effect transistors (SB MOSFETs) reveal low extrinsic parasitic resistances, offer easy processing and allow for well-defined device geometries down to the smallest dimensions. In this work, we investigated the arrhenius plots of the SB MOSFETs with different S/D schottky barrier (SB) heights between simulated and experimental current-voltage characteristics. We fabricated SB MOSFETs using difference S/D metals such as Cr (${\Phi}_{Cr}$ ~4.5 eV) and Ni (${\Phi}_{Ni}$~5.2 eV), respectively. Schottky barrier height (${\Phi}_B$) of the fabricated devices were measured to be 0.25~0.31 eV (Cr-S/D device) and 0.16~0.18 eV (Ni-S/D device), respectively in the temperature range of 300 K and 475 K. The experimental results have been compared with 2-dimensional simulations, which allowed bandgap diagram analysis.

• Journal of the Korean Ceramic Society
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• v.18 no.1
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• pp.27-34
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• 1981

The phase separation of low-alkali borosilicate glass with the composition of $6.25Na_2O$.$18.75B_2O_3$.$75.00SiO_2$(mole%) substituting $Li_2O$ for $Na_2O$ was studied. The phase separation in the temperature range of transformation was examined with various heating temperatures and soaking times. Durability to water, thermal expansion and specific density of the specimen were investigated and the microstructure of the separated phase was also observed by transmission electron micrograph techniques. The maximum alkali extraction result with the best phase separation effect was obtained when $Na_2O$ of the base glass was replaced with $1.88Li_2O$ (mole %) and electron micrograph of carbon film replica of $1.88Li_2O$$4.37Na_2O$.$18.75B_2O_3$.$75.00SiO_2$ (mole %) glass showed that the glass consisted of homogeneous two phases. The minimum specific density was shown with the specimen treated at 57$0^{\circ}C$ and it was also shown that the longer the treating time the lower the specific density. The apparent activation energies of approximately 45 kcal/mole by the alkali extraction and 43kcal/mole by the thermal expansion method were derived from the Arrhenius plots, respectively.

• Korean Journal of Materials Research
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• v.9 no.7
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• pp.675-679
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• 1999

An investigation was performed to prepare spherical cobalt powder with about particle size of 400nm from aqueous cobalt hydroxide slurry under hydrothermal reduction conditions using palladium chloride as a catalyst. The reduction kinetics was in good agreement with a surface reaction core model equation. and the activation energy obtained from Arrhenius plots was 55.6 KJ/mol at the temperature range of $145~195^{\circ}C$. Additionally, the study showed that the cobalt reduction rate is proportional to the initial hydrogen pressure with a reaction order of n=0.63. which corresponds to the gas chemisorption reaction type.

• Journal of the Korean Ceramic Society
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• v.40 no.10
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• pp.1015-1020
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• 2003

The Corrosion behavior of the matrix of the $\rho$-alumina bonded alumina vibrated castable was, on the basis of Jabsen's theory, elucidated by use of the Kingery's reaction mechanism. Corrosion of the matrix during induction period was controlled by the molecular diffusion. The temperature dependence of activation process is well established by the Arrhenius plots. The difference of Ca concentration between slag and interface is 23.2%, which causes a driving force of the materials transfer. The extent of the corrosion of the matrix is more deeper than that of the sintered mullite, but the corrosion mechanism can be well employed as the reaction mechanism proposed by the Kingery. The life time of the castable may be well estimated by the corrosion mechanism of Kingery.

• Archives of Pharmacal Research
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• v.24 no.2
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• pp.159-163
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• 2001

The accelerated stability of dimethoxy biphenyl monocarboxylate.HCl (DDB-S) was investigated in 6 mg/mL water solution in the pH ranging 2-10 and the temperature of $45-85^{\circ}C$. The observed rate of degradation followed first-order kinetics. The energy of activation for DDB-S degradation was calculated to be 14.1 and 16.5 $Kcal/mole$ at pH 5 and in distilled watery respectively. The degradation rate constant ($K_{25^{\circ}C}$) obtained by trending line analysis of Arrhenius plots for DDB-S was $5.3{\times}10^{-6}h^{-1}$. The times to degrade 10% ($t_{10}$) and 50% $t_{500}$) at $K_{25^{\circ}C}$ were 829 and 5,416 days, respectively. DDB-S exhibited the fastest degradation at pH 10 and the slowest rate at pH 5. In addition, at $K_{65^{\circ}C}$, degradation rate constants of DDB-S were 0.066, 0.059, 5.460, 32.171, and $1.4{\times}10^{-6}h^{-1}$ at pH 2, 5, 8, 10 and in distilled water, respectively. These observations indicated that the rate-pH profile of DDB-S showed general acid-base catalysis reaction in the range of pH 2-10.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.27 no.10
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• pp.668-672
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• 2014

Carbon nanotubes(CNT) has chemical stability and great sensitivity characteristics. In particular, the gas sensor required characteristics such as rapid, selectivity and sensitivity sensor. Therefore, CNT are ideal materials to gas sensor. So, we fabricated the NOx gas sensors of MOS-FET type using the MWCNT (multi-walled carbon nanotube). The fabricated sensor was used to detect the NOx gas for the variation of $V_{gs}$(gate-source voltage) and electrode changed electrode spacing=30, 60, 90[${\mu}m$]. The gas sensor absorbed with the NOx gas molecules showed the decrease of resistance, and the sensitivity of sensor was increased by magnification of electrode spacing. Furthermore, when the voltage($V_{gs}$) was applied to the gas sensor, the decrease in resistance was increased. On the other hand, the sensor sensitivity for the injection of NOx gas was the highest value at the electrode spacing $90[{\mu}m]$. We also obtained the adsorption energy($U_a$) using the Arrhenius plots by the reduction of resistance due to the voltage variations. As a result, we obtained that the adsorption energy was increased with the increment of the applied voltages.

• Bulletin of the Korean Chemical Society
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• v.21 no.6
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• pp.571-576
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• 2000

Electrocatalytic effects for the reduction of thionyl chloride in $LiAICI_4/SOCl_2$ electrolyte solution containing Schiff base M(II) (M; Co and Fe) complexes are evaluated by determining kinetic parameters with cyclic voltammetry and chronoamperometry at a glassy carbon electrode. The charge transfer process during the reduction of thionyl chloride is affected by the concentration of the catalyst. The catalytic effects are demonstrated from both a shift of the reduction potential for the thionyl chloride toward a more positive direction and an increase in peak currents. Catalytic effects are larger in thionyl chloride solutions containing the binuclear [M(II) $_2$ (TSBP)] complex rather than mononuclear [M(II)(BSDT)] complexes. Significant improvements in the cell performance have been noted in terms of both thermodynamics and activation energy for the thionyl chloride reduction. The activation energy calculated from the Arrhenius plots is 4.5-5.9 kcal/mole at bare glassy carbon electrodes. The activation energy calculated for the catalyst containing solution is 3.3-4.9 kcalmole, depending on whether the temperature is lowered or rasied.