• Membrane and Water Treatment
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• v.8 no.3
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• pp.245-257
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• 2017

The separation of nicotine and tobacco-specific N-nitrosamines is a tough problem in tobacco industry. In this study, separation of nicotine from 4-(methylnitrosamino) -1-(3-pyridyl)-1-butanone (NNK) mixtures was investigated using electrodialysis by taking the principle of the protonation status difference between these two components. The results indicated that the solution pH has a dominant impact on the separation process. In a pH range of 5-7, nicotine molecules are existed as mono- and di-protonated ions and can be separated from the uncharged NNK molecules. The acidic electrolyte is conducive to the separation process from the point of flux and energy consumption; while the alkaline electrolyte has negative impact on the separation process. A current density of $10mA/cm^2$ is an appropriate value for the separation process. The lowest energy consumption of the separation process is 0.58 kWh/kg nicotine with the process cost to be estimated at only $0.208 /kg nicotine. Naturally, electrodialysis is a high-efficiency, cost-effective, and environmentally friendly process to separate and purify nicotine from tobacco juice.

• Journal of Aquaculture
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• v.18 no.3
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• pp.189-195
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• 2005

By testing the separation performance for a fine settleable solid removal system in an aquaculture system using polystyrene particles as an experimental substitute, the optimal geometric dimensions for a Low-Pressure Hydrocyclone (LPH) were obtained. The design approach far the LPH took into consideration two inflow diameters (Di: 30, 50 mm), three overflow diameters (Do: 60, 70, 100 mm) and four cylinder lengths (Lc: 250, 345, 442, 575 mm), while the cylinder diameter (Dc) at 335 mm, the underflow diameter (Du) at 50 mm and the cone angle (${\theta}$) at $68^{\circ}$ were kept constant. The separation performances of 19 different dimension combinations of LPH were tested, ranging from 300 to 1200 ml/sec of inflow rate using substitute polystyrene particles (0.4-0.7 mm dia., ${\rho}_s=1.05g/cm^3$). These polystyrene particles exhibit a similar density and settling velocity to the fine fecal debris of the common carp. The total separation efficiency for the inflow rate ranged from a high of 97% to a low of 20%. Experimental results obtained by ANCOVA and the Tukey test (${\alpha}=0.05$) showed that the separation performances of the LPH were significantly affected (P<0.05) by the fi, Di, Do and Lc. The maximum separation performance was detected at a dimension combination of 30 mm of inflow diameter (Di), 60 mm of overflow diameter (Do), 442 and 575 mm of cylinder length (Lc). The dimension proportions were 0.09, 1.32-1.72, 0.18 and 0.15 for Di/Dc, Lc/Dc, Do/Dc and Du/Dc respectively.

• Applied Chemistry for Engineering
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• v.4 no.3
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• pp.515-521
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• 1993

Separation of deasphalted oil from atmospheric residue using n-pentane as a solvent was carried out to obtain the valuable heavy hydrocarbon products that can be used lube base oil. After separation experiments, it is shown that the separation yield of oil from atmospheric residue was dependent on n-pentane density and increased in the critical region of n-pentane. Also, the metal content of separated oil was much lowered when compared with that of atmospheric residue. However, there's slight differences in sulfur removal between above two cases.

• 한국전산유체공학회:학술대회논문집
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• 2008.03b
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• pp.218-219
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• 2008

A gas-liquid centrifugal separator is widely used in industry because of its simple geometry and little maintenance. Also, these separators have considerable advantages over filters, scrubbers or precipitators in term of compact design, low pressure drop and higher capacity. A gas-liquid centrifugal separator is a device that utilizes centrifugal force and low pressure to separate liquid from gas by density difference. Design parameters such as length of separation space, swirl vane exit angle, inlet to outlet pipe diameter ratio, models for separation efficiency and low pressure drop as a function of physical dimension are not available in literature. In present study, length of separation space (from vane to gas exit opening) has been studied using CFD. The 3-D Navier-Stokes equations are numerically solved using a fully implicit finite volume scheme. Based upon the obtained solutions, tangential velocities, centrifugal forces, vortices and total pressure losses are analyzed to find the best design parameters.

• Transactions of the Korean hydrogen and new energy society
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• v.21 no.2
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• pp.117-122
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• 2010

BCY($Ba(Ce_{0.9}Y_{0.1})O_{3-\delta}$) oxide, shows high protonic conductivity at high temperatures, and are referred to as hydrogen separation membrane. For high efficiency of hydrogen separation ($H_2$ flux and selectivity) and low fabrication cost, ultimate thin and dense BCY-Ni layer have to be coated on a porous substrate such as $ZrO_2$. Aerosol depostion (AD) process is a novel technique to grow ceramic film with high density and nano-crystal structure at room-temperature, and would be applied to the fabrication process of AD integration ceramic layer effectively. XRD and SEM measurements were conducted in order to analyze the characteristics of BCY-Ni membrane fabricated by AD process.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.1
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• pp.49.2-49.2
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• 2012

We present an investigation of X-ray hot gas halo in 12 isolated early-type galaxies from cross-matched sample of XMM-Newton and SDSS DR 7(0.025 < z < 0.08588 and Mr <-19.5). Isolated galaxies that the separation between galaxy and the closest neighbor is farther than its virial radius are not affected by environments, and their X-ray hot gas halo can be studied without contribution of intragalactic medium in all circumstances. We find that isolated galaxies in low density have correlation of $L_X-L_R$ and those in high density have no trend. This suggests that internal process is much effective in low density and environmental effects play important role of this relationship in high density. We also find the galaxies affected by environments in the large scale structure. In this paper, we report preliminary results for the study.

• Progress in Superconductivity
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• v.11 no.2
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• pp.112-117
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• 2010

We examine phase transition of the spin density wave and $\pi$ phase shifted superconductivity in the Fe pnictide superconductors. The phase diagram is described in the plane of the temperature T and the doping x with the combination of Ginzburg-Landau expansion of the free energy near the multi-critical temperature $T_c$ and the self-consistent numerical iterations of the gap equations. The phase separation or coexistence is determined by computing the 4-th order terms of the free energy which is confirmed by the numerical calculations. We can show the phase coexistence when the spin density wave is incommensurate. And the first order phase transition is observed near the boundary between commensurate and incommensurate spin density wave.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.402-404
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• 2000

In this study, we have developed an ultrasonic separation system for plant cells and its operating conditions in terms of voltage, flow rate and concentration were examined. For plant cell, the operation of ultrasonic separator highly depended on concentration of cells. Holding capacity highly depended on flow rate in chamber. Optimum voltage was 30V in high density culture

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2018.11a
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• pp.181-182
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• 2018

• Resources Recycling
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• v.19 no.5
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• pp.31-43
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• 2010

To fabricate porous SiC candle filter for filtration facility of the IGCC system, the candle type filter preforms were fabricated by ramming and vacuum extrusion process. A commercially available ${\alpha}$-SiC powders with various particle size were used as starting raw materials, and $44\;{\mu}m$ mullite, $CaCO_3$ powder were used as non-clay based inorganic sintering additive. The candle typed preforms by ramming process and vacuum extrusion were sintered at $1400^{\circ}C$ for 2h in air atmosphere. The effect of forming method and particle size of filter matrix on porosity, density, strength (flexural and compressive strength) and microstructure of the sintered porous SiC candle tilters were investigated. The sintered porous SiC filters which were fabricated by ramming process have more higher density and strength than extruded filter in same particle size of the matrix, and its maximum density and 3-point bending strength were $2.00\;g/cm^3$ and 45 MPa, respectively. Also, corrosion test of the sintered candle filter specimens by different forming method was performed at $600^{\circ}C$ for 2400h using IGCC syngas atmosphere for estimation of long-term reliability of the candle filter matrix.