• Journal of Power System Engineering
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• v.5 no.1
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• pp.64-72
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• 2001

According to the regulation of IMO, oil discharge from ships is allowed under 15ppm only and an oil filtering equipment is essential. However, for large ships using heavy fuel oil of over S.G 0.98 and viscosity 380cSt and system oil, it has been in difficulty to process with existing filtering type of oily water separator. A parallel plate type oily water separator which is one of gravity type separators can be used as an assistant equipment for the oil filtering system to meet the present IMO standard of 15 ppm, because it is an efficient method in dealing with a large amount of rich oil with high specific gravity. This work is focused on the fundamental investigation of the performance of the plate type oily water separator by visualization method and PIV(Particle Image Velocimetry) measurement to acquire multi-point velocity data simultaneously. The experimental results showed that the space of the plates acts a significant role in separating process and it was found that an important point to minimize a vortex flow is to flow a large amount of fluid in space of the plates in order to promote the efficiency of separation.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.53 no.4
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• pp.404-412
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• 2017

A centrifugal cyclone dust collecting apparatus includes a hydro cyclone dust collecting apparatus for separating solid or liquid using liquid or suspension as a medium. In this study, the formation mechanism and improvement of air core and inner air layer were confirmed through Particle Image Velocimetry. These results showed that the modified experimental model was designed in the conventional method suitable for the separation of juvenile fish and eggs. The inlet speed of the multi-stage hydrocyclone dust collector, which can increase the inlet velocity and minimize floatage in the turbulence chamber, was increased from 0.15 to 0.30 m/s. As a result, the air core was stably formed, the inner air layer was increased with increasing speed. In addition, the dust collecting efficiency of egg and juvenile fish was 97.8% on average, It can infer that this system confirmed the ability to efficiently collect particles of $40{\mu}m$ or more.

• Food Science and Biotechnology
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• v.18 no.5
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• pp.1161-1172
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• 2009

Food nanoemulsion systems consisting of water and oleoresin capsicum (OC), polyoxythylene sorbitan esters (Tween 20, 40, 60, and 80), propylene glycol (PG), sucrose monostearate (SM), and their corresponding mixtures were formulated to use as food vehicles. Tween 80 produced OC nanoemulsions with stable dispersions as one-phase systems, and the dertermined emulsification efficiencies clearly distinguished the ability of the various surfactants to emulsify OC. The nanoemulsions were prepared by both ultrasonication and self-assembly, and the nanoemulsion areas were determined using phase diagrams by measuring the sizes of the emulsions. One-phase nanoemulsions were presented, with a multiple cloudy region and phase separation that were dependent on the particle size of the emulsion. The OC nanoemulsions prepared by ultrasonication using systems of OC/Tween 80/water, OC/Tween 80/water+PG, and OC/Tween 80/water+SM, resulted in particle sizes ranging from 15 to 100 nm. Finally, the nanoemulsions maintained their initial sizes during storage, ranging from 65 to 92 nm.

• Bulletin of the Korean Chemical Society
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• v.29 no.3
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• pp.609-614
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• 2008

A periodic mesoporous organosilica material was synthesized by microwave heating (PMO-M) using 1,2-bis(trimethoxysilyl)ethane as a precursor in a cationic surfactant solution, and textural properties were compared with those of the product produced by conventional convection heating (PMO-C). These synthesized materials were characterized using XRD, TEM/SEM, N2 adsorption isotherm, 29Si and 13C NMR, and TGA, which confirmed their good structural orders and clear arrangements of uniform 3D-channels. Synthesis time was reduced from 21 h in PMO-C to 2-4 h in PMO-M. PMO-M was made of spherical particles of 1.5-2.2 m m size, whereas PMO-C was made of decaoctahedron-shaped particles of ca. 8.0 m m size. Effect of synthesis temperature, time, and heating mode on the PMO particle morphology was examined. The particle size of PMO-M could be controlled by changing the heating rate by adjusting microwave power level. PMO-M demonstrated improved separation of selected organic compounds compared to PMO-C in a reversed phase HPLC experiment. Ti-grafted PMO-M also resulted in higher conversion in liquid phase cyclohexene epoxidation than by Ti-PMO-C.

• Geomechanics and Engineering
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• v.17 no.6
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• pp.543-551
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• 2019

In China, serious environmental problems are induced by the extremely soft construction waste slurries in many urban areas, and there is no appropriate method to treat it presently. In this paper, four model tests were conducted to investigate the efficiency of waste slurry treatment by combining three conditioning agents which can change characteristics of the slurries with a traditional vacuum preloading method. The tests of size analysis of particle aggregate were conducted to investigate the influence of different conditioning agents on the size distributions of particle aggregate. During the model test, the discharged water volumes were monitored. The pore-size distribution and void ratio of the waste slurries after the vacuum preloading were measured by mercury intrusion porosimetry (MIP). It is found that 1) During the natural precipitation, volume of water out of the organic agent is higher than that of the mixed agent, but it is smaller than that of the mixed agent in the vacuum preloading stage; 2) the mixed agent has a higher total volume of water out than the organic agent and the inorganic agent after test, while the organic agent and the inorganic agent have little difference with respect to the drainage effect. The results demonstrate that the combination of mixed conditioning agent and vacuum preloading for the solid-liquid separation in waste slurry has a satisfactory effect and can be applied in engineering practice.

• Steel and Composite Structures
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• v.32 no.4
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• pp.455-466
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• 2019

Despite the rapid advancement in computing resources, many real-life design and optimization problems in structural engineering involve huge computation costs. To counter such challenges, approximate models are often used as surrogates for the highly accurate but time intensive finite element models. In this paper, surrogates for first-order shear deformation based finite element models are built using a polynomial regression approach. Using statistical techniques like Box-Cox transformation and ANOVA, the effectiveness of the surrogates is enhanced. The accuracy of the surrogate models is evaluated using statistical metrics like $R^2$, $R^2{_{adj}}$, $R^2{_{pred}}$ and $Q^2{_{F3}}$. By combining these surrogates with nature-inspired multi-criteria decision-making algorithms, namely multi-objective genetic algorithm (MOGA) and multi-objective particle swarm optimization (MOPSO), the optimal combination of various design variables to simultaneously maximize fundamental frequency and frequency separation is predicted. It is seen that the proposed approach is simple, effective and good at inexpensively producing a host of optimal solutions.

• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.3
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• pp.317-324
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• 2020

Plastic wastes generated from domestic waste are separated by mixed discharge with foreign substances, and the cost of the separation and screening process increases, so recycling is relatively low. In this study, as a fundamental study for recycling mixed plastic wastes generated from domestic waste into concrete aggregates, changes in concrete properties according to the plastic waste types and the substitution rate were evaluated experimentally. The mixed plastic waste aggregate(MPWA) was found to have a lower density and a higher absorption rate compared to the coarse aggregate with good particle size distribution. On the other hand, the single plastic waste aggregate(SPWA) was composed of particles of uniform size, and both the density and the absorption rate were lower than that of the fin e aggregate. It was found that the MPWA substitution concrete did not cause a material separation phenomenon due to a relatively good particle size distribution even with the largest amount of plastic waste substitution, and the amount of air flow increased little. The compressive strength and flexural strength of the PWA substitution concrete decreased as the amount of substitution of the PWA increased due to the low strength of the PWA, the suppression of the cement hydration reaction due to hydrophobicity, and the low adhesion between the PWA and the cement paste. It was found that the degree of deterioration in compressive strength and flexural strength of concrete substituted with MPWA having good particle size distribution was relatively small.

• Journal of the Mineralogical Society of Korea
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• v.15 no.4
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• pp.293-304
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• 2002

Wet purification process for the selective separation of montmorillonite from Gampo 13 and 35 bentonite ores was studied using physical processes such as ultrasonic scrubbing, decantation and centrifugation. Ultrasonic Scrubbing of Gampo 13 and 35 bentonite ores was revealed excellent result at 7 wt.% of slurry density and was almost finished within 30 minutes in the sample of Gampo 13 and 10 minutes in the sample of Gampo 35, respectively After decantation, approximately 52 wt.% from the bentonite of Gampo 13 and 64wt.% from the bentonite of Gampo 35 were recovered as purified products and the CEC was reached up to 119.4 meq/100 g and 124.5 meq/100 g, respectively. Particle separation by centrifugation showed that most of the impurity minerals such as quartz and feldspar were removed within the condition of 1,000 rpm.

• Polymer(Korea)
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• v.30 no.2
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• pp.152-157
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• 2006

Anionic or Zwitter-ionic waterbone polyurethanes (WPU) based on mixtures of hydroxy terminated poly-butadiene and poly(propylene glycol) were prepared and their physical properties were characterized. Particle size of WPU increased with increasing the content of HTPB. It was observed that the microphase separation of soft segments and hart segments increased with increasing the content of HTPB in the WPUs. Zwitter-ionic WPU showed stronger hydrogen bonds between molecules than anionic WPU after drying. Polyurethane films obtained after drying of WPUs exhibit besmechanical properties when the HTPB content among polyols for WPUs were 25wt%. It is postulated that such mechanical properties resulted from different microphase separation of soft segments and hard segments of polyurethane films obtainec after drying of WPUs.

• Resources Recycling
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• v.3 no.1
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• pp.38-43
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• 1994

The separation of valuable metals from IC chip scrap generated by domestic electronic company was carried out using the mechanical beneficiation such as shredding, crushing, screening and magnetic separation. The distribution of metals in various sizes of crushed IC chip scrap was investigated and metals present in crushed products was separated with the magnetic separator. The particle size distribution of crushed IC chip scrap was 7.5% for +3mm, 17.0% for 3~1mm and 75.5% for -1mm. The weight loss of crushed IC chip scrap was 18% when roasted at $700^{\circ}C$. The content of metals was 96% for +3~1mm, 13% for 1~0.595mm, 3.7% for 0.95~0.5. Au of 99% was present in -1mm crushed IC chip scrap. Ni, Fe, Cu, Sn and Pb were separated from crushed IC chip scrap by the magnetic separator under 700 and 2, 500 Gauss.