• Membrane and Water Treatment
• /
• v.4 no.1
• /
• pp.11-25
• /
• 2013

Emulsion liquid membrane (ELM) process suffers from emulsion instability problem. So far, emulsion produced by mechanical methods such as stirrer and homogenizer has big size and high emulsion breakage. This paper discussed the application of emulsion produced by sonicator to extract cadmium in a batch ELM system. The emulsions consist of N,N-Dioctyl-1-octanamine (trioctylamine/TOA), nitrogen trihydride (ammonia/NH4OH), sorbitan monooleate (Span 80), and kerosene as carrier, stripping solution, emulsifying agent, and organic diluent, respectively. Effects of comprehensive parameters on extraction efficiency of Cd(II) such as emulsification time, extraction time, stirring speed, surfactant concentration, initial feed phase concentration, carrier concentration, volume ratio of the emulsion to feed phase, and pH of initial feed phase were evaluated. The results showed that extraction efficiencies of Cd(II) greater than 98% could be obtained under the following conditions: 15 minutes of emulsification time, 4 wt.% of Span 80 concentration, 4 wt.% of TOA concentration, 15 minutes of extraction time, 250 rpm of stirring speed, 100 ppm of initial feed concentration, volume ratio of emulsion to feed phase of 1:5, and initial feed pH of 1.53.

• KIEAE Journal
• /
• v.6 no.4
• /
• pp.11-16
• /
• 2006

This work has carried out some preliminary studies for the utilization of a solar mini-dish system capable of concentrating solar rays to higher densities. A typical mini-dish system considered employs an array of solar mini-dishes where major components are light and compact. It consists of small mini-dishes, optical fiber bundles and diffusers at the end. Each mini-dish (typically has a 20 to 30 cm in diameter) is designed with a simple parabolic profile, concentrating sunlight (after the glass glazing cover to avoid dust deposition on the reflector and facilitate cleaning) onto a centrally-located small mirror which is placed on the bottom side of the transparent glass cover. The focused sunlight is reflected by the mirror surface onto a focal point where the receiving aperture of a homogenizer is located. Optical fibers are used to carry high-density solar rays to the other end where diffusers are mounted for indoor illumination. The proposed high density mini-dish system could make an efficient daylighting system as it excludes large moving parts and expandable if necessary. Each component of the system could be made from the off-the-shelf technology and thus, make the generic unit inexpensive to manufacture. Depending on spatial demand or characteristics, the amount of introducing daylight could be controlled. Preliminary tests have been carried out for a trial system to check any functional problems when in operation. Suggestions are also made to improve the design enhancing its performance and applicability.

• Food Science of Animal Resources
• /
• v.32 no.3
• /
• pp.369-375
• /
• 2012

The current study was carried out to investigate the impact of extraction conditions on the free amino acid level and type in beef longissimus muscle. The sample blocks were chiller aged for 1 d and 7 d at $4^{\circ}C$. There are three homogenization speeds (11,000, 19,000 and 24,000 rpm) for bigger and two speeds (11,000 and 13,000 rpm) for smaller homogenizer's dispersing tools were used for evaluation. Results showed that chiller ageing greatly (p<0.05) increased extractable free amino acids, except cystine. Homogenization with the bigger dispersing tool at 24,000 rpm resulted in the highest free amino acid levels for both 1 and 7 d samples. Significant differences (p<0.05) in the mean values of most amino acids due to the effect of speed and interactions between ageing times. However, the speed effect and interaction between ageing with homogenization speed were not significant (p>0.05) for most of the amino acids except valine and isoleucine when using the smaller dispensing tools. The current data indicated that a standardized method for free amino acid types and levels of aged beef samples. In addition, the results also suggested that utilization of a big dispensing tool at high homogenization speed is a better condition for releasing free amino acid contents in beef samples.

• Journal of Dairy Science and Biotechnology
• /
• v.26 no.2
• /
• pp.45-49
• /
• 2008

We studied the feasibility of monitoring and controlling the manufacturing process of an infant formula with rice starch by testing in-process samples using rheology. We used DSC to first determine the gelatinization temperature of the rice starch, a key ingredient of this product. With this characteristic temperature and the process design known, rheological measurements were conducted on the in-process samples for detecting the presence and extent of gelatinization and retrogradation of rice starch; in-process samples were collected from the carbohydrate tank, after the homogenizer, and the finished product tank. The correlation between the rheological measurements on these samples and manufacturing performance proved that rheology is a very sensitive tool for monitoring the structural development of this infant formula during main process, and their influence on sterilization efficiency. We observed that the lower degree of gelatinization during main process, a shorter residence time in the finished product tank, and using caustic flush rather than clean-in-place additively lead to higher sterilization efficiency. These findings can be utilized for a rational design and analysis of the manufacturing process for infant formulas containing rice starch.

• Korean Journal of Materials Research
• /
• v.19 no.3
• /
• pp.156-162
• /
• 2009

Lubricant-based nanofluids were prepared by dispersing carbon nanoparticles in gear oil. In this study, the effects of the particle size, shape and dispersity of the particles on the tribological properties of nanofluids were investigated. Dispersion experiments were conducted with a high-speed bead mill and an ultrasonic homogenizer, and the surfaces of the nanoparticles were simultaneously modified with several dispersants. The effective thermal conductivity of the nanofluids was measured by the transient hot-wire method, and the tribological behaviors of the nanofluids were also investigated with a disk-on-disk tribo-tester. The results of this study clearly showed that the combination of the nanoparticles, the deagglomeration process, the dispersant and the dispersion solvent is very important for the dispersity and tribological properties of nanofluids. Lubricant-based nanofluids showed relatively low thermal conductivity enhancement, but they were highly effective in decreasing the frictional heat that was generated. For nanofluids containing 0.1vol.% graphite particles in an oil lubricant, The friction coefficient in the boundary and fluid lubrication range was reduced to approximately 70% of the original value of pure lubricant.

• Korean Journal of Materials Research
• /
• v.17 no.9
• /
• pp.493-499
• /
• 2007

Oil-based nanofluids were prepared by dispersing nonconducting fibrous $Al_2O_3$ and spherical AlN nanoparticles in transformer oil. In this study, the effects of wet grinding and surface modification of particles on thermal and electrical properties of nanofluids were investigated. Grinding experiments were conducted with high-speed bead mill and ultrasonic homogenizer and nanoparticles were surface modified by oleic acid and polyoxyethylene alkyl acid ester(PAAE) in n-hexane or transformer oil, at the same time. It is obvious that the combination of nanoparticle, dispersant and dispersion solvent is very important for the dispersity of nanofluids. For nanofluids containing 1.0vol.% AlN particles in transformer oil, the enhancement of thermal conductivity was 11.6% compared with pure transformer oil. However, the electric-insulating property of AlN nanofluids was very low due to used dispersant itself. Therefore, the effect of the dispersant on thermal/electrical/physical properties of the transformer oil should be considered before selecting a proper dispersant.

• Fibers and Polymers
• /
• v.3 no.4
• /
• pp.159-168
• /
• 2002

Polyurethane foams were produced by using a homogenizer as a mixing equipment. Effects of stirring speed on the foam structure were investigated with SEM observations. Variation of the bubble size, density of the foam, compressive strength, and thermal conductivity were studied. A hybrid foam consisting of polyurethane foam and commercial polystyrene foam is produced. Mechanical and thermal properties of the hybrid foam were compared with those of pure polyurethane foam. Advancement of flow front during mold filling was observed by using a digital camcorder. Four types of mold geometry were used for mold filling experiments. Flow during mold filling was analyzed by using a two-dimensional control volume finite element method. Variation of foam density with respect to time was experimentally measured. Creeping flow, uniform density, uniform conversion, and uniform temperature were assumed for the numerical simulation. It was assumed for the numerical analysis that the cavity has thin planar geometry and the viscosity is constant. The theoretical predictions were compared with the experimental results and showed good agreement.

• Proceedings of the SAREK Conference
• /
• 2006.06a
• /
• pp.162-167
• /
• 2006

Nanofluid is a kind of new engineering material consisting of nanoparticles dispersed in base fluid. Nanofluids could have various applications such as magnetic fluids, heat exchanger working fluids, lubricants, drug delivery and so on in present study, various nanoparticles, such as MWCNT (Multi-walled Carbon Nanotube), fullerene, copper oxide, and silicon dioxide are used to produce nanofluids. As base fluids, DI-water, ethylene glycol, oil, and silicon oil are used. To investigate the thermo-physical properties of nanofluids, thermal conductivity and kinematic viscosity are measured. Stability estimation of nanofluid is conducted with UV-vis spectrophoto-meter. In this study, the high pressure homogenizer is the most effective method to produce nanofluid with the prepared nanoparticle and base fluid. Excellently stable nanofluids are produced with the magnetron sputtering system. Thermal conductivity of nanofluid increases with increasing particle volume fraction except water-based fullerene nanofluid which has lower thermal conductivity than base fluid due to its lower thermal conductivity, 0.4 W/mK. The experimental results can't be predicted by Jang and Choi model.

• Journal of Practical Agriculture & Fisheries Research
• /
• v.23 no.2
• /
• pp.33-41
• /
• 2021

The effect of homogenization treatment on the suspension stability of makgeolli was evaluated. The non-soluble solids of makgeolli that were not homogenized were precipitated at 1.0-68 mm after 10 minutes of standing and 2.0-70.5 mm after 30 minutes of standing. On the other hand, in the makgeolli homogenized with a blender for more than 20 seconds, no precipitated non-soluble solids were observed during the initial 10 minutes, and when it was left still for 30 minutes, it showed precipitation of 2.0 mm (control 58.0 mm). The makgeolli treated with a high-pressure homogenizer did not show any sedimentation until 30 minutes of standing. In the sensory evaluation, the high-pressure homogenized makgeolli had a score of 3.93, whereas non-treated had a score of 2.80, which was improved by 40% by homogenization.

• Korean Journal of Food Science and Technology
• /
• v.48 no.2
• /
• pp.111-116
• /
• 2016

To determine the optimum condition for the extraction of active components, noni adventitious roots were extracted under various conditions employing various solvents including methanolic water at different ratio (20, 40, 60, 80, and 100% water), extraction times and extraction methods. Anthraquinones, phenolic compounds, and flavonoids extraction using different solvents showed that 1 h of ultrasonic extraction was effective in 60-80% methanol, and 2 h of reflux extraction was effective in 80% methanol. To compare the extraction efficiency of active components according to different extraction methods and extraction times for noni adventitious roots, the active components were extracted by ultrasonic extraction, shaking extraction, reflux extraction, homogenizer extraction, high-pressure extraction, and soaking extraction. The highest phenolic contents were found in the extracted from ultrasonic extraction and anthraquinones and flavonoids contents were highest in the reflux extraction.