• 한국연소학회:학술대회논문집
• /
• 2006.10a
• /
• pp.260-265
• /
• 2006

An experimental study on the catalytic reformer adopted in the auxiliary power unit system of solid oxide fuel cell was conducted. A 3-fluid nozzle, by which liquid fuel such as diesel, water and air are sprayed and uniformed mixed, was designed and used in this study. An electrically heated monolith inserted in the reformer was used for the vaporization of fuel and water in the transient state of reformer. The reformer uses the partial oxidizing reaction at the catalyst and the supply of water prevents the flame combustion in the spraying zone and lessens the deactivation of catalyst. The result showed that the reforming of liquid fuel can be started by the electrically heated monolith and the 3-fluid nozzle can give the uniform mixing of fuel, water and air. It was also found that the reformer fueled by n-hexadecane can make the reformate, at best, containing $H_2$ at 15.5% and CO at 11.5% that are used as fuel in the solid oxide fuel cell.

• Journal of Sensor Science and Technology
• /
• v.13 no.4
• /
• pp.298-302
• /
• 2004

Thick films of $LaNiO_{3}$ having perovskite structure impregnated with indium and bismuth oxides have been used as sensing material for acetonitrile ($CH_{3}CN$) gas. The sensor response for $CH_{3}CN$ is quite good with an excellent recovery for partial pressure from 3 ppm to 20 ppm between 200 and $250^{\circ}C$. $LaNiO_{3}$ alone has exhibited low response, but after impregnation of $In_{2}O_{3}$ and $Bi_{2}O_{3}$ have given increased sensitivity even with 3 ppm partial pressure of $CH_{3}CN$ at $200^{\circ}C$. It is assumed that $CH_{3}CN$ is undergoing oxidation reaction on surface of the film.

• Food Science of Animal Resources
• /
• v.40 no.4
• /
• pp.649-658
• /
• 2020

This study compared aroma compositions and sensory aroma attributes of raw and cooked Tenebrio molitor larvae (mealworms). Main sensory aroma attributes of raw mealworms were strong wet-soil-like, and less-intense oily, shrimp-like and sweet-corn-like. Quantitatively, the major aroma components of raw mealworms were hydrocarbons and aldehydes. As cooking proceeded, sweet-corn-like, roasted, and fried-oil-like sensory attributes were increasingly perceived with steaming, roasting, and frying, respectively. Some pyrazines, pyrrolidines, and carbonyls increased or appeared in roasted and fried mealworms. Partial least squares regression also showed differences in raw and cooked mealworms based on aroma components and their sensory attributes. Unlike raw mealworms, steamed mealworms had a relatively strong sweet-corn-like aroma attribute, which was related to 2,4,6-trimethyl-heptane, 2,4-dimethyl-dodecane, and 3,5-dihydroxy-6-methyl-2,3-dihydropyran-4-one. In comparison, roasted and fried mealworms exhibited roasted, shrimp-like, and fried-oil-like aroma attributes, which were associated with intermediates of the Maillard reaction and lipid oxidation, such as pyrazines, alcohols, and aldehydes. This result during thermal reactions was very similar to those of meat and/or seafood. The use of mealworms as a savory-type flavor enhancer can be expected.

• Journal of Korean Society on Water Environment
• /
• v.22 no.4
• /
• pp.711-719
• /
• 2006

The effluent from anaerobic digestion process of slurry-type piggery waste has a characteristic of very low C/N ratio. Because of high nitrogen content, it is necessary to evaluate nitrogen removal alternative rather than conventional nitrification-denitrification scheme. In this study, two parallel treatment schemes of SBR-like partial nitritation reactor coupled with anaerobic ammonium oxidation (ANAMMOX) reactor, and a nitritation reactor followed by nitrite denitrification process were evaluated with a slurry-type piggery waste. The feed to reactors adjusted with various $NH_4-N$ and organics concentration. The nitrite accumulation was successfully accomplished at the loading rate of about $1.0kgNH_4-N/m^3-day$. The $NO_2-N/NH_4-N$ ratio 1~2.6 in nitritated effluent that operated at HRT of 1 day indicated that SBR-like partial nitritation was applicable to ANAMMOX operation. Meanwhile, the nitrite accumulation of 87% was achieved at SBR operated with HRT of 3 days and $0.4mgO_2/L$ for denitritation. Experimental results further suggested that HRT (SRT) and free ammonia(FA) rather than DO are an effective control parameter for nitrite accumulation in piggery waste.

• Electrical & Electronic Materials
• /
• v.7 no.1
• /
• pp.32-41
• /
• 1994

In this study, the TSC spectroscopy has been applied to investigate the influence of structural change due to a process of curing reaction on the electrical properties of epoxy composites cured with acid-anhydride. Five TSC peaks appeared in -160-250[.deg.C]: in the low temperature region below glass transition temperature(T$\_$g/), three relaxation mode peaks due to action of side chains, substitution group or terminal groups have been observed, a peak associated with T$\_$g/, appeared in 110[.deg. C] and p peak due to ionic space charges located in 150[.deg.C]. Each peak was separated into elementary peaks by the partial polarization procedure, and the distribution of activation energy and relaxation time were analized to clearify the origin of each peak. Also, overaboundantly added hardener separated a .betha. peak near 10[.deg. C] into two peaks of .betha.$\_$1/(10.deg. C) and .betha.$\_$2/(20.deg. C) according to increasement of forming field, and the separated hardener was oxidated thermally with increasing surrounding temperatures. The expansion of the free volume need in molecular motion and the reduction of the structural packing density through thermal oxidation process increased TSC between .alpha. peak and .betha. peak and decreased T$\_$g/.

• Proceedings of the Korean Society for Agricultural Machinery Conference
• /
• 1996.06c
• /
• pp.918-925
• /
• 1996

The effect of structured water by dissolution of xenon was examined from the view point of the suppression of both browning and respiratory metabolism of broccoli. The structured water is formed duet to hydrophobic interaction when xenon gas dissolves into water. NMR measurements were carried out to determine proton spin-spin relaxation time, T2, for water. There was a difference in proton T2 between distilled water and structured water. This can be interpreted as the change of water structure. Fro the broccoli cut in half stored for 16 days at 279K, the section color did not change appreciably for the sample whose water was structured by dissolution of xenon whose initial partial pressure was 0.39MPa. In contrast to this, the browning of section surface was observed for the sample stored under the condition of nitrogen gas at the same partial pressure as xenon and for the sample stored under atmospheric condition . These results led to the conclusion that the suppression of b owning by oxidation was due to structured water but not to applied pressure. Adding to this, the water structured by xenon has resulted in suppression of respiratory metabolism of broccoli.

• Journal of the Korean Ceramic Society
• /
• v.34 no.7
• /
• pp.722-730
• /
• 1997

The nonstoichiometry (x) of UO2+x and (Er0.06U0.94)O2+x has been in-situ measure against oxygen activity (Po2) at elevated temperatures by a coulometric titration method. From the dependence of the oxygen excess (x) of UO2+x on Po2 at 1000℃, it has been concluded that (2Vo2Oia2Oib)〃〃and (2Vo2Oia2Oib)' clusters are prevailing at low oxygen partial pressure [log(Po2/atm) -10.6] and at high oxygen partial pressure [log(Po2/atm) -10.6], respectively. The nonstoichiometry is found to be reduced with the addition of Er, which is ascribed to the fact that the fixed-valent Er3+ reduces the oxidation capacities of UO2+x. The enthalpy of oxygen incorporation in (Er0.06li0.94)O2+x has been evaluated from the mean valences of U-ion as -180±70 kJ/mole.

• Resources Recycling
• /
• v.11 no.6
• /
• pp.47-54
• /
• 2002

Copper concentrate particles were fed from the top of vertical reaction tube of 2.8 cm ID and 65 cm long with an $O_2$-$N_2$ gas mixture. The reaction tube was heated to 1000 K to 1400 K. The copper concentrate particles were very rapidly oxidized and melted down during their descent in the reaction tube. The particle temperature were calculated by combining an unreacted core model, mass transfer between gas and particles, and heat transfer between gas, particles and tube wall. The particle temperature reached its maximum at the height of 20 to 30 cm from the top of the reaction tube, and it attained about 1700 K at higher oxy-gen partial pressure. The most particles were melted at the oxygen partial pressure above 0.2 atm.

• Journal of the Mineralogical Society of Korea
• /
• v.15 no.3
• /
• pp.183-194
• /
• 2002

Biotite and its weathering Products in the weathering Profile of Andong granite were examined using X-ray diffraction, chemical analysis, and electron microscopy. Major weathering product of biotite was oxidized biotite, which is decomposed into kaolinite in the upper part. Discrete vermiculite or hydrobiotite was not detected although minor vermiculite (5%) was randomly interstratified with oxidized biotite. Excess positive charge induced by iron oxidation was balanced by release of Fe (16%) and Mg (12%) from octahedral site and K (13%) from interlayer site. After slight chemical and structural modification induced by iron oxidation, oxidized biotite persists through the weathering profiles with partial decomposition in the upper part of the profile. Formation environments and dissolution experiments of oxidized biotite highly resistant to weathering are required to understand the elemental behavior in the surface environments on the biotite-bearing bedrocks.

• Journal of the Korean Chemical Society
• /
• v.18 no.2
• /
• pp.117-125
• /
• 1974

The catalytic reaction between carbon monoxide and oxygen was investigated in the presence of catalysts which were specially treated by applying an annealing method at different monoxide and oxygen and at reaction temperatures in the region of partial pressures of carbon $40^{\circ}C$ to $95^{\circ}C$. The oxidation rate is highest on NiO annealed at low temperature in vacuum. The data has been correlated with the first order kinetics, and the activation energies from the Arrhenius equation are found to be 4Kcal/mole in the region of the experimental temperatures. The excess oxygen in NiO obtained from the decomposition of $NiCO_3$does not cause activation at $95^{\circ}C$. But NiO catalysts annealed again in vacuum display activation even at $40^{\circ}C$. The quantity of the excess oxygen in NiO surfaces seems to be the controlling factor in determining the rates of oxidation of carbon monoxide.