• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.13 no.7
• /
• pp.3261-3266
• /
• 2012

Sodium borohydride($NaBH_4$) known as the material of hydrogen generation and storage can produce the hydrogen via catalytic hydrolysis. This protide chemical could be used in the hydrogen supply system for residential and mobile fuel cells, and thus many researches and developments regarding to these chemicals and decomposition reactions have been implemented. We experimented the hydrolysis of $NaBH_4$ alkaline solution by metal oxide-supported PGM(platinum group metal) catalysts and measured the generation rate of hydrogen which is product of decomposition reaction. We compared oxides as catalyst supports, and the precious metals, Pt and Ru for the catalysts and studied the effects of amounts of catalyst added and $NaBH_4$ concentrations on the hydrogen generation rates and patterns.

• Food Science of Animal Resources
• /
• v.21 no.4
• /
• pp.329-336
• /
• 2001

The experiments were carried out to investigate the aging effect between loin muscles from Hanwoo and Helstein. Two kinds of loin samples were prepared from the carcasses of grade B2 from Hanwoo and D from Holstein. The carcasses were chilled for 24 hours after slaughter. The carcasses was obtained by chilling the loin fort 1 day after wrapping it. On the other hand. was obtained divided by 500g and stored at 2$^{\circ}C$ for 11 days after air packing. In the case of fresh beef pH and lactic acid of grade B2 were lower than that of grade D. Hardness and chewiness of grade B2 were lower than that of grade D, but myofibrillar fragmentation index(MFI) of glade B2 were higher than that of grade D. Total concentrations of free amino acid of grade B2 were higher than those of D. The contents of monounsaturated fatty acid of grade B2 was lower than grade D, and monosaturated fatty acid/saturated fatty acid(MUFA/SFA) of grade B2 were higher than grade D. The contents of nonprotein nitrogen of the aged beef was higher than the fresh beef, and beef of grade B2 was higher than that of grade D. In case of aging beef. cooking loss of grade B2 was lower than grade D.

• Journal of Korean Society of Environmental Engineers
• /
• v.29 no.6
• /
• pp.678-683
• /
• 2007

We isolated a toluene-degrading bacterium, TDB-4, from a bioreactor which designed to remove volatile organic compounds (VOCs) from the contaminated air. Based on the results of 16S rRNA gene analysis, it was classified as Pseudomonas sp. The toluene degradability was estimated in the variable toluene and bacterial concentrations. The bacterial growth and degradation rate was higher in the samples supplied with 50 ${\mu}mole/vial$ of toluene than with 10 ${\mu}mole/vial$. It was decreased, however, in the samples with 100 ${\mu}mole/vial$, indicating that toluene inhibit the growth or degradation activity of TDB-4 at high concentration. When the degradation ability of other compounds was examined, TDB-4 can degrade other VOCs such as styrene, benzene, and xylene. These results will be helpful to optimize the operating conditions to improve the efficiency of a bioreactor in detoxification of VOCs.

• Journal of Conservation Science
• /
• v.26 no.2
• /
• pp.203-211
• /
• 2010

Analytic research on the surface pollutant of the three storied-pagoda at the west of Gameunsaji site as well as studies of previous wet cleaning cases was undertaken in order to decide cleaning method for removing inorganic pollutants. The status of pollutant was examined by naked eye observation, SEM-EDS, XRD. Then it was compared and categorized through qualitive and quantitative analysis. The result showed that the surface pollutants consisted of iron compounds or sulfur compounds and it was crystallized in the form of circle, oval, needle, etc. Result, Low-pressure rotating vortex process cleaning, with which particular matters are sprayed in swirl, is considered to be the best method to remove the pollutants.

• Applied Biological Chemistry
• /
• v.33 no.2
• /
• pp.120-124
• /
• 1990

The occurrence of falcarinol(n-heptadeca-1, 9-dien-4,6-diyn-3-ol)in the umbelliferous plants such as Ladebouriella seseloides WOLFF., Cnidium officinale MAKINO, Foeniculum vulgare GAERTNER, Torilis japonica(HOUTT.) DC. Bupleurum falcatum L.,Angelica gigas NAKAI, Oenanthe javanica (BL.) DC. and Daucus carota var. sativa DC. was investigated using gas chromatography/mass spectrometry(GC/MS). Falcarinol was found in the root of Ledebouriella seseloides, the stem and the root of Oenanthe javanica, and the root of Daucus carota var. sativa in which its contents were $1,055\;{\mu}g/g$, $289\;{\mu}g/g$, $179\;{\mu}g/g$, and $212\;{\mu}g/g$, respectively, while it was not found in the other plants.

• Journal of the Korean Chemical Society
• /
• v.20 no.5
• /
• pp.398-405
• /
• 1976

A new compound, 1,2-bispyrazyl ethylene,is synthesized starting from pyrazine carboxylic acid and methyl pyrazine. The compound is characterized utilizing UV-VIS, IR, NMR and mass spectra along with elemental analysis. Spectroscopic properties are studied from UV-VIS and fluorescence spectra. From unusual salt effects on fluorescence spectra, it is believed that $(n,\;{\pi}^*)$ state has about the same energy as $({\pi},\;{\pi}^*)$ state. The compound fluoresces from $({\pi},\;{\pi}^*)$ state with the quantum yield of 0.025 at $77^{\circ}K$ compared to near unity for stilbene at the same temperature indicating the efficient intersystem crossing to triplet state, because of strong $(n,\;{\pi}^*)$ and $({\pi},\;{\pi}^*)$ mixing in the lowest excited state.

• Journal of the Korean Electrochemical Society
• /
• v.13 no.2
• /
• pp.96-102
• /
• 2010

Effects of specimen area on the corrosion rate of low alloy steel were studied in sulfuric acid solution. The corrosion behavior of specimen was tested by electrochemical impedance spectroscopy (EIS), linear polarization resistance measurement (LPR) and potentiodynamic polarization measurement. The surface was analyzed by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and electron probe X-ray micro analyzer (EPMA). As surface area was increased, corrosion rate was increased by the effect of small anode-large cathode.

• Resources Recycling
• /
• v.26 no.3
• /
• pp.17-25
• /
• 2017

Electric arc furnace steelmaking dust has various physicochemical properties as volatile components generated in the melting process of steel scraps in an electric arc furnace, which is captured in oxide form as fine powder by reacting with oxygen in the air. In order to efficiently recycle these electric arc furnace dust, a kinetic basic experiment and a pilot production test were carried out in parallel. As a result, it was found that the electric arc furnace dust contain a large amount of Cl and alkali components, thus it was expected that the compounds have a great adverse effect on the actual operation for the recycling. It was confirmed that the volatilization behavior was progressing actively at $1100^{\circ}C$ and the electric arc furnace dust was melted at $1250^{\circ}C$. These results are the same as a result of pilot test for the formation behavior of zinc oxide and reduced iron. These results should be useful as basic data for designing the recycling plant of the electric arc furnace dust and establishing the operating conditions.

• Korean Chemical Engineering Research
• /
• v.53 no.4
• /
• pp.457-462
• /
• 2015

Hemicellulosic hydrolysates contain not only sugars but also several kinds of ethanol fermentation inhibitory substances such as carboxylic acids, furans and phenolic compounds. In this work, emulsion liquid membrane (ELM) was chosen as a separation technology to remove the inhibitors. A basic simulated hemicellulosic hydrolysate was composed of xylose as sugar, dilute sulfuric acid solution as solvent, and acetic acid as carboxylic acid, and furfural as furan derivative or p-hydroxybenzoic acid(HBA) as phenolic compound was added to the hydrolysate when necessary. Acetic acid and HBA as weak acid could be selectively removed from the hydrolysates in all the ELM systems considered here, but furfural as aldehyde was quite hard to remove. Also, when HBA was added to the basic simulated hemicellulosic hydrolysate, both of acetic acid and HBA in the feed phase could be selectively removed up to 99% in an ELM system with tributyl phosphate as extractant.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2017.05a
• /
• pp.475-481
• /
• 2017

In this paper, high speed camera images were used to analyze the supercritical injection behavior of liquid hydrocarbon compounds used as main components of propellant fuel. Decane and Methylcyclohexane (MCH), which have different critical points among kerosene constituents, were selected as experimental fluid and Shadowgraphy technique was used for the analysis. The difference in the temperature variation from the initial injector state of the subcritical condition until the vaporization occurs was represented by the different behaviors of Decane and MCH. However, under the Supercritical conditions, the enthalpy of vaporization near the critical point approaches zero and the phase change to the Supercritical phase occurs instead of vaporization process. In the phase change of the Supercritical system, there was no rapid density change, so the liquid state image was observed in both the Decane and MCH.