• Food Science of Animal Resources
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• v.40 no.2
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• pp.209-220
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• 2020

Milk fat globule membrane (MFGM) is a lipid carrier in mammals including humans that consists mainly of polar lipids, like phospholipids and glycolipids. In this study, a process to enrich polar lipids in commercial butter and whey powder, including polar lipids of MFGM, was developed. WPC (whey protein concentrate) 60 was selected as the most suitable raw material based on the yield, phospholipid, protein, and lactose content of the polar lipid fraction obtained by ethanol extraction of two WPC (WPC60 and WPC70) and two buttermilk (A and B). After fractionation under optimum conditions, the polar-lipid enriched fraction from WPC60 contained 38.56% phospholipids. The content of glycolipids, cerebroside, lactosylceramide, ganglioside GM3, ganglioside GD3, was 0.97%, 0.55%, 0.09%, and 0.14%, respectively. Rancimat results showed that the oxidation stability of fish oil increased with an increase in the polar-lipid fraction by more than 30 times. In addition, the secretion of IL-6 and TNF-α decreased in a concentration-dependent manner after treatment of RAW 264.7 cells with 0.1 to 100 ppm of the polar lipid fraction. In this study, polar lipid concentrates with antioxidant and anti-inflammatory activity, were prepared from milk processing by-products. The MFGM polar lipid concentrates made from by-products are not only additives for infants, but are also likely to be used as antioxidants in cooking oils and as active ingredients for functional foods.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2005.10a
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• pp.175-179
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• 2005

Treatment of Emulsion is very important to development of Bilge Separator for new IMO Regulation. It is too difficult to demulsify the emulsion in the bilge waste water, so we use chemical treatment to break emulsion stability. Broken oil particle is treated by flotation. Bilge Separator on the Ship doesn't have enough time to treat Bilge waste water because of small space in the ship. For the solution to this problem, we experiment to find primary factor as coagulator, pH, and amount of coagulator. As the basis of test, we decided coagulator, pH and quantity of coagulator.

• Journal of Climate Change Research
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• v.9 no.1
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• pp.59-67
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• 2018

In this study, the $N_2O$, emitted from combustion facility, were analyzed by using simulated gas and field samples to find out how long samples can be stored in Tedlar bag. According to the results of the experiment using simulated gases (1 ppm, 5 ppm, 10 ppm) in Tedlar bag, After 144hr, $N_2O$ concentration of simulated gases changed that 1 ppm is 5.3%, 5 ppm is 12.8%, and 10ppm is 10.5%. The higher initial concentration of simulated gas was, the larger rate of $N_2O$ concentration was changed. In case of high concentration samples, it need to be careful when it was analyzed after 144 hr. Stability evaluation in Tedlar bag was carried out through field samples such as combustion facility of bituminous coal, B-C oil and LNG. The concentration rate of field samples, which is under 1 ppm of average initial concentration, was evaluated using statistical method. As a result, $N_2O$ concentrations were changed to field samples in the bag even when 96 hr had passed. And after sampling, it is necessary that sample analysis should be quickly as soon as possible.

• Microbiology and Biotechnology Letters
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• v.48 no.4
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• pp.491-505
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• 2020

A newly isolated strain, Proteus vulgaris OR34, from olive mill waste was found to secrete an alkaline extracellular lipase at 11 U·ml-1 when cultivated on an optimized liquid medium. This lipase was purified 94.64-fold with a total yield of 9.11% and its maximal specific activity was shown to be 3232.58 and 1777.92 U·mg-1 when evaluated using the pH-stat technique at 55℃ and pH 9 and Tributyrin TC4 or olive oil as the substrate. The molecular mass of the pure OR34 lipase was estimated to be around 31 kDa, as revealed by SDS-PAGE and its substrate specificity was investigated using a variety of triglycerides. This assay revealed that OR34 lipase preferred short and medium chain fatty acids. In addition, this lipase was stable in the presence of high concentrations of bile salt (NaDC) and calcium ions appear not to be necessary for its activity. This lipase was inhibited by THL (Orlistat) which confirmed its identity as a serine enzyme. In addition, the immobilization of OR34 lipase by adsorption onto calcium carbonate increased its stability at higher temperatures and within a larger pH range. The immobilized lipase exhibited a high tolerance to organic solvents and retained 60% of its activity after 10 months of storage at 4℃. Finally, the OR34 lipase was applied in biodiesel synthesis via oleic acid mediated esterification of methanol when using hexane as solvent. The best conversion yield (67%) was obtained at 12 h and 40℃ using the immobilized enzyme and this enzyme could be reused for six cycles with the same efficiency.

• Proceedings of KOSOMES biannual meeting
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• 2006.05a
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• pp.103-108
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• 2006

Treatment of O/W Emulsion is very important to develop 15ppm Bilge Separator for new IMO regulation It is too difficult to demulsify the emulsion in the bilge waste water, so we use chemical treatment to break emulsion stability. Broken oil particle is treated by flotation 15ppm Bilge Separator on the Ship doesn't have enough time to treat Bilge waste water because of limited space in the ship. For the solution to this problem, we experiment to find primary factors as coagulant, pH, amount of inputting coagulant, and type of flotation. On the basis of test results, we decided primary factors.

• Journal of Advanced Marine Engineering and Technology
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• v.31 no.1
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• pp.26-33
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• 2007

The intake swirl motion, as one of dominant effects for an engine combustion. is very effective for turbulence enhancement during the compression process in the cylinder of 2-valve engine. Because the combustion flame speed is determined by the turbulence that is mainly generated from the mean flow of the charge air motion in intake port system. This paper describes the experimental results of swirl flow and combustion characteristics by using the oil spot method and back-scattering Laser Doppler velocimeter (LDV) in 2-valve single cylinder transparent LPG engine using the liquid phase LPG injection. For this. various intake port configurations were developed by using the flow box system and swirl ratios for different intake port configurations were determined by impulse swirl meter in a steady flow rig test. And the effects of intake swirl ratio on combustion characteristics in an LPG engine were analyzed with some analysis parameters that is swirl ratio. mean flow coefficient, swirl mean velocity fuel conversion efficiency. combustion duration and cyclic variations of indicated mean effective pressure(IMEP). As these research results, we found that the intake port configuration with swirl ratio of 2.0 that has a reasonable lean combustion stability is very suitable to an $11{\ell}$ heavy-duty LPG engine with liquid phase fuel injection system. It also has a better mean flow coefficient of 0.34 to develope a stable flame kernel and to produce high performance. This research expects to clarify major factor that effects on the design of intake port efficiently with the optimized swirl ratio for the heavy duty LPG engine.

• Proceedings of the Korean Society for Rock Mechanics Conference
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• 2000.09a
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• pp.93-103
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• 2000

The concrete plug in an underground cavern prevents the stored product (oil, gas, etc) from leaking and the excessive show of underground water, so it plays an important role in construction and operation of the storage cavern. Additionally, it should maintain its stability under every possible loading condition. Once the plug is constructed, the cavern is isolated from the external access. Therefore, mechanical and hydraulic consideration should be made in construction to fulfill its function. Therefore, in this study, numerical analyses were conducted to study the optimal shape and thickness of the plug with respect to the various conditions of installation depth, the shape of the plug, in-situ stress ratio (K), the condition of rock-plug interface, and the effect of Excavation Damaged Zone (EDZ). This paper also presents the effect of slot depth on the hydraulic behavior of the plug. These analyses were carried out by using the 2-dimensional finite difference code, rm FLAC, and the 3D code, m FLA $C^{3D}$./.

• Korean Journal of Food Science and Technology
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• v.20 no.3
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• pp.344-349
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• 1988

Proteolysis of 7S and 11S soy protein-rich fraction(PRF) with commercial proteases(alcalase and pronase) apperently increased protein solubility at pH 5, heat coagulation and calcium tolerence, while decreasing emulsifying capacity and foam stability regardless of the kind of protein and protease used. However, the proteolysis decreased the protein solubility of 7S PRF at pH 6 and 11S PRF at pH 4. The proteolysis of 11S PRF increased oil absorption and foam expansion, while slight decrease or almost no change was noted on 7S PRF. Heat stabilities of the emulsion and kinetic viscosities changed very little by the proteolysis.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.12
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• pp.1483-1487
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• 2013

Water injection pump outputs oil with high pressure during this process, seawater is injected into the well to recover the well pressure and maintain high productivity. A water injection pump has high productivity, and therefore, it serves as a key piece of equipment in marine plants. In this light, water injection pumps are being studied widely in industry. In this study, the rotor dynamics is analyzed to determine the natural frequency according to the bearing stiffness and operation speed change. This study aims to establish the pump reliability through critical speed, stability, and unbalance response analysis.

• Membrane Journal
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• v.31 no.6
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• pp.393-403
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• 2021

Enzymes are important class of catalyst for biotransformation. Stability and reusability of enzymes during the catalysis process is a key issue. Activity of enzyme can be enhanced by its immobilization on a suitable substrate by creation of specific microenvironment. A variety of membranes has been used as substrate due to the biocompatibility and simpler method to tune hydrophilicity/hydrophobicity property of the membrane surface. In this review, polymer membranes including cellulose, polyacrylonitrile (PAN), polydimethylsiloxane (PDMS), polyvinylidene fluoride (PVDF), polyethersulfone (PES) are introduced and discussed in detail. Biodegradation of organic contaminants by immobilized enzyme is an environmental friendly process to reduce the contamination of environment in pharmaceutical company and textile industries. The controlled hydrolysis of oil can be performed in enzyme immobilized membrane bioreactor (EMBR), resulting in reducing carbon emission and reduced environmental pollution. Bioethanol and biodiesel are considered alternative fossil fuels that can be prepared in EMBR.