• Fisheries and Aquatic Sciences
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• v.17 no.1
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• pp.67-73
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• 2014

The oil in mackerel muscle was extracted using an environment friendly solvent, supercritical carbon dioxide (SC-$CO_2$) at a semibatch flow extraction process and an n-hexane. The SC-$CO_2$ was maintained at a temperature of $45^{\circ}C$ under pressures ranging from 15 to 25 MPa. The flow rate of $CO_2$ (27 g/min) was constant during the entire 2 h extraction period. The fatty acid composition of the oil was analyzed using gas chromatography (GC). Significant concentrations of eicosapentaenoic acid (EPA) acid and docosahexaenoic acid (DHA) acid were present in the SC-$CO_2$ extracted oil. The oil extracted using SC-$CO_2$ exhibited increased stability compared with n-haxane extracted oil. Particles of mackerel oil together with the biodegradable polymer, polyethylene glycol (PEG) were formed using a gas saturated solution process (PGSS) with SC-$CO_2$ in a thermostatted stirred vessel. Different temperatures ($45-55^{\circ}C$), pressures (15-25 MPa) and a nozzle size $400{\mu}m$ were used for PGSS with a 1 h reaction time. The stability of mackerel oil in the particles did not changed significantly.

• Advances in nano research
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• v.1 no.2
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• pp.93-103
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• 2013

An ultrasonic-mediated assisted stepwise method has been developed for depositing transparent ZnO films from aqueous solution. Rinsing in low ethylene glycol temperature was easy to produce intermediate phase of $Zn(OH)_2$, rinsing in $120^{\circ}C$ ethylene glycol was observed the diffraction peak of intermediate $Zn(OH)_2$ in early report, the rinsing temperature plays an important role in the process of $Zn(OH)_2$ phase transformed to ZnO, high rinsing temperature actually improved the intermediate phase. However, the effect of rinsing on the intermediate phase is yet to be understood clearly. The effect of different rinsing procedures, involving either of or a combination of successive ionic layer adsorption and reaction (SILAR) and ultrasonic-assisted rinsing, prior to hydrolysis in ethylene glycol was found to improve the occurrence $Zn(OH)_2$ in ZnO thin films. In the zinc complex ($[Zn(NH_3)_4]^{2+}$) solution, excess ($[Zn(NH_3)_4]^{2+}$) absorbed in glass substrate transformed incompletely to ZnO and exist as $Zn(OH)_2$ phase in thin films. In films deposited at low temperature, rinsing procedure is applied to improve excess $Zn(OH)_2$ and obtain smoother transparent thin films.

• Polymer(Korea)
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• v.25 no.1
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• pp.15-24
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• 2001

In this study, the effects of different glycol molar ratios of unsaturated polyester(UPE) resins on the curing behaviors were investigated. The cross linking process was checked or monitored by differential scanning calorimetry(DSC) and by viscoelastic properties of rigid-body pendulum model. The knife-edge from which the pendulum is suspended, is immersed in a reaction mixture, and the change of the viscoelastic behavior brings on those of the period(T) and logarithmic decrement(${\Delta}$) of the damped free oscillations of the pendulum. The values of T and ${\Delta}$ obtained are related to the dynamic modulus(E') and modulus loss(E'). The information on the viscoelastic behavior of unsaturated polyester(UPE) resins during the curing process are shown to illustrate the usefulness of the techniques. As the content of NPG in a propylene glycol(PG)/NPG glycol mixture increased, both the cycle time during cure and the change of damping during cure of UPE resin decreased.

• Journal of Powder Materials
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• v.10 no.5
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• pp.310-317
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• 2003

Two-component ceramic (alumina-zirconia) composites were fabricated by a soft-solution process in which polyethylene glycol (PEG) was used as a polymeric carrier. Metal salts and PEG were dissolved in ethyl alcohol without any precipitation in 1:1 volume ratio of alumina and zirconia. In the non-aqueous system, the flammable solvent made explosive, exothermic reaction during drying process. The reaction resulted in formation of volume expanded, porous precursor powders by a vigorous decomposition of organic components in the precursor sol. The PEG content affected the grain size of sintered composites as well as the morphology of precursor powders. The difference of microstructure in sintered composite was attribute to the solubility and homogeneity of metal cations in precursor sol. At the optimum amount of the PEG polymer, the metal ions were dispersed effectively in solution and a homogeneous polymeric network was formed. It made less agglomerated particles in the precursor sol and affected on uniform grain size in sintered composite.

• Journal of Yeungnam Medical Science
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• v.2 no.1
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• pp.175-181
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• 1985

Agrobacterium tumefaciens induces cancerous growths called crown galls at wound sites on dicotyledonous plants. A large plasmid called Ti plasmid is responsible for virulence. Upon tumor induction, part of the plasmid, termed T-DNA, becomes integrated into plant genome and its genetic sequences are expressed. These properties allow Ti plasmids to be used as gene vectors in plants. Several in vitro methods for the transfer of Ti plasmid into plant cell have been developed. One of them is the treatment of bacterial spheroplasts and plant protoplasts mixture with polyethylene glycol that is generally used as fusogen in cell-to-cell fusion. Several workers investigated the interaction of bacterial spheroplasts with plant protoplasts in the presence of polyethylene glycol and suggested that the interaction is not fusion but endocytosis. In this report we observed the interaction of Agrobacterium tumefaciens spheroplasts with Nicotiana tabacum protoplasts by electron microscope. Agrobacterium tumefaciens spheroplasts and Nicotiana tabacum protoplasts were prepared and mixed in the presence of polyethylene glycol and high pH-high $Ca^{2+}$ buffer. Then the interaction of the spheroplasts with the protoplasts was examined by transmission electron microscope. After the treatment of polyethylene glycol the spheroplasts adhered to the surface of the protoplasts and then they were engulfed by the protoplasts. After the high pH-high $Ca^{2+}$ buffer treatment the engulfed spheroplasts lost their cell integrity. No fusion process was observed. Thus all these observations suggest that the introduction process of Agrobacterium tumefaciens spheroplasts into Nicotiana tabacum protoplasts with the aid of polyethylene glycol is endocytosis.

• Clean Technology
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• v.22 no.4
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• pp.241-249
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• 2016

In this study, comparative work has been performed between two-columns and three-columns configurations for an extractive distillation process to produce highly purified ethanol with not less than 99.7 wt% using dimethyl sulfoxide (DMSO) and ethylene glycol (EG) as extracting agents. Optimal ethanol concentration at a concentrator top stream which minimized the total reboiler heat duties was determined for a three-columns configuration for two different solvents. For the thermodynamic model, NRTL liquid activity coefficient model was used and PRO/II with PROVISION 9.4 at Schneider electric company was utilized. DMSO was proved to be a better solvent than EG and three-columns configuration is better than two- columns configuration in the total utility consumptions since some of the liquid water contained in the feed stream was removed at a concentrator bottom liquid stream.

• Korean Chemical Engineering Research
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• v.53 no.2
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• pp.181-192
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• 2015

The aim of this study is to obtain optimum process condition for using two tower distribution to recycle the waste Propylene Glycol Monomethyl Ether Acetate (PGMEA) that is formed after washing LCD. The optimum process condition for the content of PGMEA, which is dependent variable, at 1st distillation was calculated according to Bottom temperature (BTM temperature), Reflux amount, Feed amount, Feed temperatures, and the optimum process conditions and optimum factors for the content of PGMEA at 2nd distillation according to Bottom temperature (BTM temperature), Reflux amount, Feed amount, Feed temperatures. At 1st distillation, Reflux amount, Feed amount, and Feed temperature are significant variables. However, it is found that the BTM temperature range is not significant in the range of process condition used in this study. The optimum process conditions are based on $5700{\ell}$ of Feed amount, $2500{\ell}$ of Reflux amount, $165^{\circ}C$ of BTM temperature, and $130^{\circ}C$ of Feed temperature. For the this condition, the predicted content of PGMEA was calculated as 92.12~94.62%. Significant factors at 2nd distillation are Reflux amount, Feed amount, and BTM temperature. Multicollinearity is between Reflux amount and BTM temperature. BTM was omitted in the multiple regression equation because there is a strong positive correlation between Reflux amount and BTM temperature. Base on $199^{\circ}C$ of BTM temperature, The optimum process conditions are based on $4275{\ell}$ of Feed amount, $6200{\ell}$ of Reflux amount and $130^{\circ}C$ of Feed temperature. In this condition, the predicted content of PGMEA was calculated as 99.0~99.5%.

• Journal of Environmental Science International
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• v.12 no.6
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• pp.635-641
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• 2003

A recycling process for the waste FRP from boats was developed. The recycling process is composed of decomposition of waste FRP with propylene glycol and synthesis of recycled unsaturated polyester resin from the decomposed liquid material. Prior to the decomposition, waste FRP was cut into 2cm x 5cm segments and mechanical impact was applied by press roller to give gaps between cumulated laminates. Propylene glycol effectively decomposed the waste FRP segments and glass fibers were easily separated from decomposed liquid material. Recycled unsaturated polyester resin could be made from the decomposed liquid material by reaction with maleic anhydride and phthalic anhydride.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.24 no.3
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• pp.365-370
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• 2014

Objectives: The major objective is development of an eco-friendly non-phthalate plasticizer using crude glycol derived from the biodiesel process. Methods: Glycerol monolaurate(GML) was synthesized from glycol and triglyrcerides. Glycerol diacetomonolaurate(GDAL) was synthesized from GML and acetic acid. Results: The synthesis of the GDAL plasticizer was measured with nuclear magnetic resonance spectroscopy(NMR). Mechanical properties were measured by universal testing machine(UTM) and the experimental values were compared with phthalate plasticizers such as dioctyl phthalate(DOP). In particular, the values for tensile strength and elongations with GDAL were higher than with DOP. Conclusions: We confirmed the development of an eco-friendly non-phthalate plasticizer by NMR. Based on our results, applicability for food and drug packaging materials was found.

• Archives of Pharmacal Research
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• v.26 no.6
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• pp.504-510
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• 2003

The aim of this study is to prepare biodegradable microspheres without the use of surfactants or emulsifiers for a novel sustained delivery carriers of protein drugs. A poly($\varepsilon$-caprolactone)/poly(ethylene glycol)/poly($\varepsilon$-caprolactone) (CEC) triblock copolymer was synthesized by the ring-opening of $\varepsilon$-caprolactone with dihydroxy poly (ethylene glycol) to prepare surfactant-free microspheres. When dichloromethane (DCM) or ethyl formate (EF) was used as a solvent, the formation of microspheres did not occur. Although the microspheres could be formed prior to lyophilization under certain conditions, the morphology of microspheres was not maintained during the filtration and lyophilization process. Surfactant-free microspheres were only formed when ethyl acetate (EA) was used as the organic solvent and showed good spherical micro-spheres although the surfaces appeared irregular. The content of the protein in the micro-sphere was lower than expected, probably because of the presence of water channels and pores. The protein release kinetics showed a burst release until 2 days and after that sustained release pattern was showed. Therefore, these observations indicated that the formation of microsphere without the use of surfactant is feasible, and, this the improved process, the protein is readily incorporated in the microsphere.