• Food Science of Animal Resources
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• v.35 no.3
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• pp.315-321
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• 2015

The aim of the present work was to investigate the effect of NaCl concentration on the emulsifying and rheological properties of porcine myofibrillar protein (MF)-stabilized soybean oil and fish oil emulsion (SO-EMs and FO-EMs). Emulsions (EMs) were prepared from 1% MF with 10% SO or FO at various NaCl concentration (0-0.5 M). The emulsifying ability index (EAI) of the EMs increased with increasing NaCl concentration for both oil types. Conversely, increasing NaCl manifested decrease in the emulsion stability index (ESI). In addition, creaming index (CI) also increased with NaCl concentration. From the microscopic observation, droplets of the EMs were more aggregated at relatively higher NaCl concentrations, especially for FO-EMs. All EMs had a gel-like structure owing to G' > G" from the rheological analysis. Comparing the oil types, the emulsifying capacity of SO-EMs was more stable than that of FO-EMs at all NaCl concentrations as determined from the CI value and microscopic observation. Therefore, it can be concluded that SO-EMs and FO-EMs are more stable at relatively lower concentrations of NaCl. In addition, the dispersed stability of SO-EMs was better than that of FO-EMs at the same concentration of NaCl.

• Journal of Korea Port Economic Association
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• v.23 no.1
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• pp.95-113
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• 2007

Recently, International institution such as IMO and major maritime countries have introduced various regulations and steps to reduce port pollution. However, recognition of environmental pollution from ports is not sufficient for Korean policy makers and port communities. The purpose of this paper is to examine solutions to port pollution problems and suggests some implications to Korean ports to become a green port. To this aim, necessity of regulation on environmental pollution from port operation; literature survey on port's environmental pollution; current conditions of international port pollution; various regulations and policies governing major ports are conducted in this paper. Our main findings are as follows; first, air pollution from ship can be reduced by providing electric power at docks while at berth, Second, in case of cargo-handling equipment, retire old equipment and switch to cleaner fuel such as low-sulfur fuel and diesel emulsions. Third, offering incentives for the installation of pollution controls and minimizing idling by enforcing idling limits or by installing idle shutoff controls can be recommended for reduction of air pollution of truck and rail at ports.

• Applied Chemistry for Engineering
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• v.5 no.3
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• pp.537-546
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• 1994

The physical characteristics of polymer modified asphalt depend on many parameters, such as, the polymer nature, polymer content and the asphalt properties. The objective of this study is to investigate the temperature susceptibility of polymer modified asphalt. The asphalts employed in this study were two different grades : a soft(200/300) grade and a hard(85/100) grade. And chlorinated polyethylene of two different characteristics were used : plastomer(Tyrin 2552) and elastomer(Tyrin CM0730). Temperature susceptibility of asphalt is a fundamental feature for characterizing asphalt and modified asphalt. It can be quantified by the penetration index(PI) and pen-vis number(PVN). These indices were obtained from the measurements of penetration and viscosity of the asphalt samples. For both of asphalts, the addition of the polymers increases the value of PI and PVN. Plastomer modified asphalt shows higher value of PI and PVN than elastomer modified asphalt. Soft grade shows more temperature susceptibility than hard grade at elevated temperatures.

• Biomolecules & Therapeutics
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• v.6 no.4
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• pp.358-363
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• 1998

Intravenous lipid emulsion is used extensively as a major component of parenteral nutrition for patients in the surgical intensive care unit. Abnormal cardiovascular function related to lipid infusion has been reported although conflicting results exist. In the present study, we investigated the effects of intravenous emulsions of long-chain triglyceride (LCT) and medium-chain triglyceride (MCT) on myocardial ischemia/ reperfusion injury and on platelet aggregation in rat. There was no difference between LCT and MCT considering the effects on left ventricular developed pressure (LVDP) and coronary flow rate (CFR) before and after ischemia/reperfusion in isolated rat heart. On the other hand, a difference was found between LCT and MCT with regard to their effects on heart rate (HR) and end diastolic pressure (EDP) after ischemia/reperfusion. After ischemia/reperfusion, HR was significantly (P<0.05) reduced and EDP significantly (P<0.05) inc.eased by LCT (18$\pm$2.0% and 42.8$\pm$8.9%, respectively), but not by MCT Ex vivo platelet aggregation induced by collagen was reduced by LCT infusion, but not by MCT These findings suggest that MCT may have slightly more favorable effect than LCT on the myocardial function after ischemia/reperfusion in rat.

• Applied Biological Chemistry
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• v.35 no.4
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• pp.265-271
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• 1992

Derivatives (microcrystalline chitin, carboxymethylchitin, acetylchitin, N-acetylchitosan, ethylchitosan and chitosansulfate) of chitin and chitosan were synthesized, and the physicochemical properties of the derivatives were compared with those of chitin and chitosan. Carboxymethylchitin was soluble in water or acetic acid, whereas chitosan and ethylchitosan were soluble in acetic acid alone. The water binding capacity of N-acetylchitosan was two fold higher than that of chitin. Lipid binding capacity of carboxymethylchitin was the highest, holding 1800%, and that of chitin was the lowest, holding 511% among the derivatives. Carboxymethylchitin among the derivatives showed the highest emulsifying capacity, however chitin and chitosan didn't produce emulsions. Dye binding capacity of acetylchitin was the highest, holding 0.93 mg dye/g sample (Blue R-250) and 0.96 mg dye/g sample (Red No. 2). It was concluded that carboxymethylchitin is a good emulsifier and N-acetylchitosan, chitosansulfate and chitosan are suitable for use as dye absorbents.

• International Journal of Highway Engineering
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• v.19 no.2
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• pp.75-85
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• 2017

PURPOSES : The purpose of this study was to determine the optimum mix design of the content of 100 % reclaimed asphalt pavement (RAP) for spray injection application with different binder types. METHODS : Literature review revealed that spray injection method is the one of the efficient and economical methods for repairing a small defective area on an asphalt pavement. The Rapid-Setting Polymer modified asphalt mixtures using two types of rapid setting polymers-asphalt emulsion and a quick setting polymer asphalt emulsion-were subjected to the following tests to determine optimum mix designs and for performance comparison: 1) Marshall stability test, 2) Retained stability test, 3) Wet track abrasion test, and 4) Dynamic stability test. RESULTS and CONCLUSIONS : Type A, B, and C emulsions were tested with different mix designs using RAP aggregates, to compare the performances and determine the optimum mix design. Performance of mixtures with Type A emulsion exceeded that of mixtures with Type B and C emulsion in all aspects. In particular, Type A binder demonstrated the highest performance for WTAT at low temperature. It demonstrated the practicality of using Type A mixture during the cold season. Furthers studies are to be performed to verify the optimum mix design for machine application. Differences in optimum mix designs for machine application and lab application will be corrected through field tests.

• Korean Journal of Materials Research
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• v.22 no.8
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• pp.433-438
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• 2012

A chemical process involves polymerization within microspheres, whereas a physical process involves the dispersion of polymer in a nonsolvent. Nano-sized monodisperse microspheres are usually prepared by chemical processes such as water-based emulsions, seed suspension polymerization, nonaqueous dispersion polymerization, and precipitation polymerizations. Polymerization was performed in a four-necked, separate-type flask equipped with a stirrer, a condenser, a nitrogen inlet, and a rubber stopper for adding the initiator with a syringe. Nitrogen was bubbled through the mixture of reagents for 1 hr. before elevating the temperature. Functional silane (3-mercaptopropyl)trimethoxysilane (MPTMS) was used for the modification of silica nanoparticles and the self-assembled monolayers obtained were characterized by X-ray photoelectron spectroscopy (XPS), laser scattering system (LSS), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), elemental analysis (EA), and thermogravimetric analysis (TGA). In addition, polymer microspheres were polymerized by radical polymerization of ${\gamma}$-mercaptopropyl modified silica nanoparticles (MPSN) and acrylamide monomer via precipitation polymerization; then, their characteristics were investigated. From the elemental analysis results, it can be concluded that the conversion rate of acrylamide monomer was 93% and that polyacrylamide grafted to MPSN nanospheres via the radical precipitation polymerization with AAm in ethanol solvent. The microspheres were successfully polymerized by the 'graft from' method.

• Journal of Microbiology and Biotechnology
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• v.11 no.3
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• pp.369-375
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• 2001

Urushiol, a natural monomeric oil, was used to prepare a detergentless micro-emulsion with water and 2-propanol The formation of micro-emulsion was verified by conductivity measurements and dynamic light scattering. The conductivity data showed phase change dynamics, a characteristics of micro-emulsions, and subsequent dynamic light scattering study further confirmed the phenomenon. Average water droplet diameter was 10 nm to 500 nm when the molar ratio of 2-propanol ranged from 0.40 to 0.44 . Earlier studies were performed on toluene and hexane, in which the insoluble substrate in water phase was added to the solvents to be reacted on by enzymes. However, in the present urushiol system, urushiol was used as both solvent and substrate in the laccase polymerization of urushiol. The laccase activity in the system was examined using polymerization of urushiol. The laccase activity in the system was examined using syringaldezine as a substrate, and the activity increased rapidly near the molar ratio of 2-propanol at 0.4, where micro-emulsion started. The activity rose until 0.46 and fell dramatically thereafter. The study of laccase activity in differing mole fractions of 2-propanol showed the existence of an ‘optimal zone’, where the activity of laccase was significantly higher. In order to analyze urushiol polymerization by laccase, a bubble column reactor using a detergentless micro-emulsion system was constructed. Comparative study using other organic solvents systems were conducted and the 2-propanol system was shown to yield the highest polymerization level. The study of laccase activity at a differing mole fraction of 2-propanol showed the existence of an ‘optimal zone’ where the activity was significantly higher. Also, 3,000 cP viscosity was achieved in actual urushi processing, using only 1/100 level of laccase present in urushi.

• Polymer(Korea)
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• v.36 no.5
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• pp.579-585
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• 2012

Polystyrene/carbon nanotube (CNT) microcellular foams were prepared to have electrically conductive properties via high internal phase emulsion polymerization. In this study, we have investigated the effects of surface modification of CNT, surfactant content and dispersion time to improve the stability of emulsion and the electrical conductivity of foam. Acid treatment and a surfactant were used to effectively disperse CNTs in the aqueous phase. In the organic phase, CNTs were used after a surface modification with organic functional groups. The degree of dispersion of CNTs was estimated by the electrical conductivity of resultant microcellular foams. With raw CNTs dispersed with the surfactant in the aqueous phase, substantial conductivity increase was observed but the foams were slightly shrunk. The foams prepared with organically modified CNTs dispersed in the organic phase showed stable cell morphology without shrinkage, but displayed limitation to improve the conductivity.

• Journal of Adhesion and Interface
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• v.16 no.2
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• pp.76-82
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• 2015

W/O emulsions were prepared from the aqueous solution containing NIPAAm, MBA, and APS in the continuous phase of toluene and mineral oil mixture with HMP and Span80 by using SPG membrane emulsification, and followed by the formation of PNIPAAm hydrogel microspheres through UV photopolymerization. As the ratio of mineral oil to toluene increased in the continuous phase, both particle size of the hydrogel increased and density of PNIPAAm polymer in the hydrogel particle increased, and which significantly affected swelling/deswelling ratio ($V/V_o$) with temperature change around VPTT. When the polymerization temperature was below LCST ($20^{\circ}C$), PNIPAAm hydrogel showed filled particle morphology; however, it was turned out to hollow particle morphology with thick shell layer with $40^{\circ}C$. Both density of PNIPAAm and gel content of the hydrogel increased with the increase in MBA concentration.