• Clean Technology
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• v.10 no.4
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• pp.203-213
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• 2004

Natural gas thermal decomposition method is the technology of converting natural gas (methane) into hydrogen and carbon at high temperature. The most advantage of thermal decomposition method is that hydrogen and carbon can be produced without emitting carbon dioxide. In this study, the generation of hydrogen and carbon was investigated by this natural gas (methane) thermal decomposition method. We found that pyrocarbon was created on the surface of reactor, carbon black was deposited on the pyrocarbon and final plugging phenomenon took place. To solve this problem, we tried several attempts such as introduction of double pipe reactor instead of single pipe reactor or oxidization of carbon black using $O_2$ or $CO_2$ at regular intervals of reaction. Therefore, some plugging phenomenon was resolved by this methods. Also, carbon particle size was measured by SEM (Scanning Electron Microscope) image and the size was about 200 nm.

• Journal of Magnetics
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• v.19 no.3
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• pp.210-214
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• 2014

The effects of manganese substitution on the crystallographic and magnetic properties of Li-Zn-Cu ferrite, $Li_{0.5}Zn_{0.2}Cu_{0.4}Mn_xFe_{2.1-x}O_4$ ($0.0{\leq}x{\leq}0.8$), were investigated. Ferrites were synthesized via a conventional ceramic method. We confirmed the formation of crystallized particles using X-ray diffraction, field emission scanning electron microscopy and $M{\ddot{o}}ssbauer$ spectroscopy. All of the samples showed a single phase with a spinel structure, and the lattice constants linearly decreased as the substituted manganese content increased, and the particle size of the samples also somewhat decreased as the doped manganese content increased. All the $M{\ddot{o}}ssbauer$ spectra can be fitted with two Zeeman sextets, which are the typical spinel ferrite spectra of $Fe^{3+}$ with A- and B-sites, and one doublet. The cation distribution was determined from the variation of the $M{\ddot{o}}ssbauer$ parameters and of the absorption area ratio. The magnetic behavior of the samples showed that an increase in manganese content led to a decrease in the saturation magnetization, whereas the coercivity was nearly constant throughout. The maximum saturation magnetization was 73.35 emu/g at x = 0.0 in $Li_{0.5}Zn_{0.2}Cu_{0.4}Mn_xFe_{2.1-x}O_4$.

• Korean Journal of Environmental Agriculture
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• v.11 no.3
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• pp.195-200
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• 1992

Heavy metal adsorption on peat was studied to examine the utilization of abundant natural resouces as pollution control. The smaller the peat particle size, the more the heavy metals studied were adsorbed. Adsorption of heavy metals on peat was greater in single metal solutions than in mixed solutions, and the order of adsorption amount on peat was Cu > Cd > Zn. The most effective pH range of the adsorption of Cd, Zn, and Cu was between 4 and 6. With increasing the concentration of heavy metals the amount of adsorption on peat was increased, but the adsorption ratio was decreased. The adsorption of heavy metals on peat was fitted to the Freundlich isotherm and peat was appeared to be an effective adsorbent of the heavy metals. The treatment of polyethyleneimine(PEI) on the peat surface effectively increased adsorption capacity of the heavy metals. Because of its higher energy content, the heavy metal adsorbed peat could be utilized as a energy source. After burning the peat, the reduced peat volume could be save the expenses for waste disposal.

• 한국신재생에너지학회:학술대회논문집
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• 2007.11a
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• pp.17-18
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• 2007

Solid oxide fuel cells are clean, pollution-free technology for the electrochemical generation of electricity at high efficiency. Specially, the polarization resistance between electrolyte and electrode of SOFC unit cell is of importance, because it is desirable to develop SOFC operating at intermediate temperature below $800^{\circ}C$. The LSCF cathode prepared using modified oxalate method was investigated with different electrolyte. A precursor was prepared with oxalic acid, ethanol and $NH_4OH$ solution. The LSCF precursor was prepared at $80^{\circ}C$, and pH control was 2, 6, 8, 9 and 10. The precursor powder was calcined at $800^{\circ}C$, $1000^{\circ}C$ and $1200^{\circ}C$ for 4hrs. The crystal of LSCF powders show single phase at pH 2, 6, 8 and 9, and the average particle size was about $3{\mu}m$. The LSCF cathode with heat treatment at $1200^{\circ}C$ showed a plot of electric conductivity versus temperature. Unit cell prepared from the LSCF cathode, buffer layer between cathode and electrolyte and the LSGM, YSZ, ScSZ and CeSZ electrolyte. Also interface reaction between LSCF, buffer layer and electrolyte were measured by EPMA and the polarization resistance for unit cell with cycle measure using a Solatron 1260 analyzer.

• Biomolecules & Therapeutics
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• v.18 no.1
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• pp.99-105
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• 2010

The purpose of this study was to evaluate relative bioavailability of the coenzyme Q10 (CoQ10) in emulsion and three liposome formulations after a single oral administration (60 mg/kg) into rats. Emulsion formulation of CoQ10 was prepared by conventional method using Phospholipon 85G as an emulsifier, and three liposome formulations (neutral, anionic, and cationic) of CoQ10 were prepared by traditional lipid film hydration technique using Phospholipon 85G, cholesterol, and charge carrier lipids (1,2-dioleoyl-3-trimethylammonium-propane chloride salt for cationic liposome and 1,2-dimyristoyl-sn-glycero-3-phosphate monosodium salt for anionic liposome). Mean particle size of all CoQ10-loaded liposome was less than a micron, and size distribution of the liposome population was homogeneous. Bioavailability of CoQ10 in emulsion was 1.5 to 2.6-fold greater than liposome formulations in terms of $AUC_{0-24\;h}$. $T_{max}$ was 3 h when administered as emulsion while it was greater than 6 h in liposome formulations. Notably, it was approximately 8 h in cationic liposome. $C_{max}$ was highest in emulsion and was significantly decreased when administered as liposome. Charged liposome showed even lower $C_{max}$ than neutral liposome, especially in cationic liposome. In conclusion, therefore, it is suggested that clinicians and patients consider bioavailability issue a primary concern when choosing a CoQ10 product, especially when very high plasma level is required such as in the treatment of heart failure and Parkinson's disease.

• Journal of the Korean Ceramic Society
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• v.50 no.3
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• pp.195-200
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• 2013

Here, we report preparation of cyan ceramic nano-pigment for inkjet printing and the Ni substitutional effects on the cyan color. $MgAl_2O_4$ was selected as the crystalline host network for the synthesis of nickel-based cyan ceramic nano-pigments. Various compositions of $Ni_xMg_{1-x}Al_2O_4$ ($0{\leq}x{\leq}1$) powders were prepared using the polymerized complex method. The powder was then preheated at $400^{\circ}C$ for 5 h and finally calcined at $1000^{\circ}C$ for 5 h. XRD patterns of $Ni_xMg_{1-x}Al_2O_4$ showed a single phase of the spinel structure in all the compositions. The particle sizes ranged from 20 to 50 nm in TEM observations. The characteristics of the color tones of $Ni_xMg_{1-x}Al_2O_4$ were analyzed by UV-Visible spectroscopy and CIE $L^*a^*b^*$ measurement. CIE $L^*a^*b^*$ measurement results indicate that the pigment color changes from light cyan to deep cyan due to the decrease of the $a^*$ and $b^*$ values with an increase of an Ni substitutional amount. In addition, the thermal stability and the binding nature of $Ni_xMg_{1-x}Al_2O_4$ are also discussed using TG-DSC and FT-IR results respectively.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.6
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• pp.486-490
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• 2012

$La_{7.33}Bi_2(SiO_4)_6O_2$ specimens were fabricated by standard solid-state synthesis route for solid oxide electrolytes. The calcined powders exhibited uniform particles with a mean particle size of about $28{\mu}m$. The room-temperature structure of $La_{7.33}Bi_2(SiO_4)_6O_2$ specimens was analyzed as hexagonal, space group P63 or P63/m, and the unit cell volume increased with increase a sintering temperature. The specimens sintered at $1,175^{\circ}C$ showed X-ray patterns of homogeneous apatite single phase without the second phase such as $La_2Si_2O_7$ and $La_2SiO_5$. The specimen sintered at $1,175^{\circ}C$ showed the maximum sintered density of 5.49 $g/cm^3$. Increasing the sintering temperature, total conductivities increased, activation energy decreased and the values were $1.98{\times}10^{-5}Scm-1$ and 1.23 eV, respectively.

• Journal of Korean Society for Atmospheric Environment
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• v.21 no.3
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• pp.343-355
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• 2005

Cloud/fog water was collected at Daegwallyeong, a typical clean environmental area, by using an active fog sampler during the foggy period in 2002, The pH ranged from 3,7 to 6,5 with a mean of 5,0, but the pH calculated from average concentrations of $H^+$ was 4.4. $SO_4^{2-},\;NO_3^-\;and\;NH_4^+$ were predominant ions with average concentrations of 473,3, 463,3 and $576,0\;{\mu}eq/L$, respectively, This showed that cloud/fog water was slightly acidified, but the concentrations of major pollutants were as high as those for polluted area, suggesting effect from long range transported pollutants, Samples were categorized into four groups (E, W, S, N) by applying 48-h back trajectory analysis using the Hybrid Single-Particle Largrangian Integrated Trajectory (HYSPLIT) model. Concentrations of seasalt $(Na^+\;and\;Cl^-)$ were the highest for group E, indicating large input of seasalts by air masses transported from the East Sea. The concentrations of $SO_4^{2-}$ were slightly higher in group W but the difference was not significant. However, the concentrations of $NO_3^-$ were significantly higher in group W than those in other three groups, The median values of cloud/fog water pH for group N and W were below 4,5, which is significantly lower than median values in group E and group S, This suggests that the acidifying pollutants were transported from the Asia continents and Seoul metropolitan area cause acidification of the cloud/fog water in Daegwallyeong.

• Asian Journal of Atmospheric Environment
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• v.5 no.1
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• pp.47-55
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• 2011

Variations in ambient atmospheric carbon monoxide(CO) observed at an inland mining site in the Indo-Gangetic plains, Jaduguda ($22^{\circ}38'N$, $86^{\circ}21'E$, 122m MSL, ~75 km away from the coast of the Bay of Bengal) during the Tsunami of 26 December 2004 were monitored. CO mixing ratio over this site was measured using a non-dispersive infrared analyzer (Monitor Europe Model 9830 B). Back trajectory analysis data obtained using NOAA Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) Model was also used for this study. Variations in CO mixing ratio at a coastal site, Thiruvananthapuram ($8^{\circ}29'N$, $76^{\circ}57'E$, located ~2 km from the Arabian Sea coast) have also been investigated using CO data retrieved from the Measurement Of Pollution In The Troposphere (MOPITT) instrument. Ground-based measurements indicated abnormal variations in CO mixing ratio at Jaduguda from 25 December 2004 evening (previous day of the Tsunami). MOPITT CO data showed an enhancement in CO mixing ratio over Thiruvananthapuram on the Tsunami day. Back trajectory analyses over Thiruvananthapuram and Jaduguda for a period of 10 days from $21^{st}$ to $30^{th}$ December 2004 depicted that there were unusual vertical movements of air from high altitudes from 25 December 2004 evening. CO as well as the back trajectory analyses data showed that the variations in the wind regimes and consequently wind driven transport are the most probable reasons for the enhancement in CO observed at Jaduguda and Thiruvananthapuram during the Tsunami.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2000.11a
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• pp.91-97
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• 2000

The conventional model did not take momentum conservation into consideration when the electron absorbs and emits the photons. II-ray provides momentum conservations on any directions of the entering photons, and also the electrons have radial momentum conservations and fully elastic bouncing between two atoms, in the new atom model. Conventional atom model must be criticized on the following four points. (1) Natural motions between positive and negative entities are not circular motions but linear going and returning ones, for examples sexual motion, tidal motion, day and night etc. Because the radius of hydrogen atom's electron orbit is the order of 10$^{-11}$ m and the radia of the nucleons in the nucleus are the order of 10$^{-l4}$m and then the converging n-gamma rays to the nucleus have so great circular momentum, the electron can not have a circular motion. We can say without doubt that any elementary mass particle can have only linear motion because of the n-rays' hindrances, near the nucleus. (2) Potential energy generation was neglected when electron changes its orbit from outer one to inner one. The h v is the kinetic energy of the photo-electron. The total energy difference between orbits comprises kinetic and potential energies. (3) The structure of the space must be taken into consideration because the properties of the electron do not change during the transition from outer orbit to inner one even though it produces photon. (4) Total energy conservation law applies to the energy flow between mind and matter because we daily experiences a interconnection between mind and body. An understanding of the mechanisms responsible for the control of normal proliferation and differentiation of the various cell types which make up the human body will undoubtedly allow a greater insight into the abnormal growth of cells, A large body of biochemical evidence was eventually used to generate a receptor model with an external ligand binding domain linked through a single trans-membrane domain to the cytoplasmic tyrosine kinase and autophosphory-lation domains. The ligand induced conformational change in the external domain generates either a push-pull or rotational signal which is transduced from the outside to the inside of cell.l.ell.