• Journal of Microbiology and Biotechnology
• /
• v.25 no.6
• /
• pp.918-929
• /
• 2015

Microbial enhanced oil recovery (MEOR) is being used more widely, and the biological contributions involved in MEOR need to be identified and quantified for the improvement of field applications. Owing to the excellent interfacial activity and the wide distribution of producing strains in oil reservoirs, lipopeptides have proved to be an essential part of the complex mechanisms in MEOR. In this study, crude lipopeptides were produced by a strain isolated from an indigenous community in an oil reservoir. It was found that crude lipopeptides can effectively reduce the IFT (interfacial tension) to 10^-1~10^-2 mN/m under high salinity without forming stable emulsions, and the wettability of natural sandstone can be enhanced (Amott index, from 0.36 to 0.48). The results of core flooding experiments indicate that an additional 5.2% of original oil in place can be recovered with a 9.5% reduction of injection pressure. After the shut-in period, the wettability of the core, the reduction of injection pressure, and the oil recovery can be improved to 0.63, 16.2% and 9.6%, respectively. In the microscopic flooding experiments, the crude oil in membrane, cluster, and throat states contribute nearly 90% in total of the additional oil recovery, and the recovery of membranestate oil was significantly enhanced by 93.3% after shut in. Based on the results in macro and pore scale, the IFT reduction and the wettability alteration are considered primary contributors to oil recovery, while the latter was more dominant after one shut-in period.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.45 no.2
• /
• pp.105-116
• /
• 2019

Oil adsorption during hair or body washing is responsible for the hair conditioning. In this study, we established a method to extract oil from a substrate, and to determine amount of adsorbed oil upon substrate using a conventional absorption spectroscopy. We controlled the mole fraction of a surfactant in a mixture of anionic and amphoteric surfactants because that it induces the coacervate that regulates amount of adsorbed oil through the alteration of oil viscosity. Based on this, we established the optimized condition for adsorption and extraction for oil. UV absorbance were employed to estimate the amount of adsorbed oil using optical absorbance after extraction via adsorption. The estimation was confirmed by comparing with a mass analysis in HPLC and an adhesive energy in AFM. It has been proved that this method can be applied to all cases of oil adsorption from the results with various cationic polymers and a complex system of the polymers which regulate the oil adsorption.

• Corrosion Science and Technology
• /
• v.7 no.4
• /
• pp.208-211
• /
• 2008

Safety operation of main pipelines is primarily provided by anticorrosive monitoring. Anticorrosive monitoring of oil pipeline transportation objects is based on results of complex corrosion inspections, analysis of basic data including design data, definition of a corrosion residual rate and diagnostic of general equipment's technical condition. All the abovementioned arrangements are regulated by normative documents. For diagnostics of corrosion-technical condition of oil pipeline transportation objects one presently uses different methods such as in-line inspection using devices with ultrasonic, magnetic or another detector, acoustic-emission diagnostics, electrometric survey, general external corrosion diagnostics and cameral processing of obtained data. Results of a complex of diagnostics give a possibility: $\cdot$ to arrange a pipeline's sectors according to a degree of corrosion danger; $\cdot$ to check up true condition of pipeline's metal; $\cdot$ to estimate technical condition and working ability of a system of anticorrosive protection. However such a control of corrosion technical condition of a main pipeline creates the appearance of estimation of a true degree of protection of an object if values of protective potential with resistive component are taken into consideration only. So in addition to corrosive technical diagnostics one must define a true residual corrosion rate taking into account protective action of electrochemical protection and true protection of a pipeline one must at times. Realized anticorrosive monitoring enables to take a reasonable decision about further operation of objects according to objects' residual life, variation of operation parameters, repair and dismantlement of objects.

• Journal of Soil and Groundwater Environment
• /
• v.24 no.1
• /
• pp.17-23
• /
• 2019

Clean soil environment is of crucial importance to sustain lives of ecosystem and humans. With rapid industrialization, there has been a great increase of soil contamination by accidental releases of petroleum products. In general, soil remediation is an expensive and time-consuming process as compared to cleanup of water and air. Moreover, determining the source and responsible parties of soil pollution often turns into legal conflicts and that further delay the cleanup process of contaminated sites. In practice, total petroleum hydrocarbon (TPH) analysis has been employed to determine the petroleum species and to track down the responsible polluters. However, this approach often suffers from differentiating similar TPH species. In this study, we analyzed TPH chromatogram patterns of 24 domestic petroleum products in specific carbon ranges (${\sim}C_{10}$, $C_{10}-C_{12}$, $C_{12}-C_{36}$, and $C_{36}{\sim}$) and the fractional changes of THP ratio in the mixture products of gasoline, kerosene and diesel. The proposed TPH analysis method in this study could serve as a useful tool to better analyze the petroleum species in soils contaminated with complex oil mixtures, and ultimately be used to identify the polluters of soil.

• YAKHAK HOEJI
• /
• v.39 no.2
• /
• pp.175-184
• /
• 1995

The interaction of omeprazole(OMP) with $\gamma$-cyclodextrin($\gamma$-CyD) was investigated by solubility study and the complexation was confirmed by means of UV/VIS spectrophotometer, circular dichroism, differential scanning calorimeter, and $^{1}$H nuclear magnetic resonance spectra. The stability, dissolution rate, and partition coefficient of the complex were measured. The results present that the benzimidazole moiety and a part of pyridine ring containing sulfur atom of OMP might be included into the cavity of $\gamma$-CyD and the formation type of inclusion complex appeared to be B$_{s}$. The stoichiometric ratio of OMP to $\gamma$-CyD in the complex was found to be 1:1 and the stability constant of the complex found to be 97.1 M$^{-1}$. And the dissolution rate of OMP was markedly increased by inclusion complex formation with $\gamma$-CyD, and so it was above 90% in 5 min. from solid complex. Oil to water partition coefficient of OMP-$\gamma$-CyD complex was 60, which is significantly higher than that of OMP itself, 36.4. The degradation rate constant of OMP were greater than OMP-$\gamma$-CyD complex in aqueous solutions of various pHs, and the half lives of OMP and OMP-$\gamma$-CyD at pH 9 were 279.2 and 509.9 days, respectively, showing that the complex was more stable than OMP, therefore it was thought that OMP was stabilized by inclusion formation with $\gamma$-CyD.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.11 no.3 s.55
• /
• pp.53-62
• /
• 2007

This paper presents a new vibration control method for long-span bridges using complex damper system. The new system presents simple mechanical configuration with oil and elasto-plastic dampers which have velocity and displacement dependency in vibration energy absorbing. This system can produce various damping forces according to the applied external forces by the velocity and displacement-dependent characteristics of the dampers. The oil damper dissipates vibration energy for relatively frequent and small amplitude like in the case for small to moderate earthquakes, whereas the elasto-plastic damper system works for rare and large amplitude vibration such as high seismic excitation. Thus, the proposed system exhibits the advantage of low cost with high performance since the roles of the two different dampers are effectively separated. A numerical model is established for the complex damper system, and the response characteristics and effectiveness of the proposed system are presented through numerical simulations. Numerical results show that the proposed complex damper system can significantly improve the seismic performance of long-span bridge structures with much more effective damping mechanism than single conventional passive damper systems.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.47
• /
• pp.175-185
• /
• 2002

Rapeseed(Brassica napus L.) is an important oil crop as a vegetable oil, concentrated feed and industrial materials. The name "canola" was registered in 1979 by the Western Canadian Oilseed Crushers Association to describe "double-low" varieties. Double low indicates that the processed oil contains less than 2% erucic-acid and the meal less than 3mg/g of glucosinolates. Today annual worldwide production of rapeseed is approximately 35 million tons on 24 million hectares. China accounts for 33% of the world production and the European Economic Community for nearly 32%. Canola ranks 3rd in production among the world's oilseed crops following soybeans, sunflowers, peanuts and cottonseed. The recent advances in genomics and in gene function studies has allowed us to understand the detailed genetic basis of many complex traits, such as flowering time, height, and disease resistance. The manipulation of seed oil content via transgene insertion has been one of the earliest successful applications of modern biotechnology in agriculture. For example, the first transgenic crop with a modified seed composition to be approved for unrestricted commercial cultivation in the US was a lauric oil, rape-seed, grown in 1995. There were also some significant early successes, mostly notably the achievement of 40% to 60% lauric acid content in rapeseed oil, which normally accumulates little or no lauric acid. The name "$\textrm{Laurical}^{TM}$" was registered in 1995 by Calgene Inc. Nevertheless, attempts to achieve high levels of other novel fatty acids in seed oils have met with much less success and there have been several reports that the presence of novel fatty acids in transgenic plants can sometimes lead to the induction of catabolic pathways which break down the novel fatty acid, i.e. the plant recognizes the "strange" fatty acid and, far from tolerating it, may even actively eliminate it from the seed oil. It is likely that, in the future, transgenic oil crops and newly domesticated oil crops will both be developed in order to provide the increased amount and diversity of oils which will be required for both edible and industrial use. It is important that we recognize that both approaches have both positive and negative points. It will be a combination of these two strategies that is most likely to supply the increasing demands for plant oils in the 21st century and beyond.ant oils in the 21st century and beyond.

• Journal of ILASS-Korea
• /
• v.25 no.4
• /
• pp.162-169
• /
• 2020

The worldwide focus on reducing the emissions, fuel and lubricant consumption in T-GDI engines is leading engineers to consider the crankcase ventilation and oil mist separation system as an important means of control. In today's passenger cars, the oil mist separation systems mainly use the inertia effect (e.g. labyrinth, cyclone etc.). Therefore, this study has investigated high efficiency cylinder head-integrated oil-mist separator by using a compact multi-impactor type oil mist separator system to ensure adequate oil mist separation performance. For this purpose, engine dynamometer testing with oil particle efficiency measurement equipment and 3D two-phase flow simulation have been performed for various engine operating conditions. Tests with an actual engine on a dynamometer showed oil aerosol particle size distributions varied depending on operating conditions. For instance, high rpm and load increases bot only blow-by gases but the amount of small size oil droplets. Submicron-sized particles (less than 0.5 ㎛) were also observed. It is also found that the impactor type separator is able to separate nearly no droplets of diameter lower than 3 ㎛. CFD results showed that the complex aerodynamics processes that lead to strong impingement and break-up can strip out large droplets and generate more small size droplets.

• Proceedings of KOSOMES biannual meeting
• /
• 2006.05a
• /
• pp.85-92
• /
• 2006

Crude oil is complex mixture if thousands of different organic compound formed from a variety of organic materials that are chemically converted under differing geological conditions over long periods of time. Also oil composition varies according to crude source, refining, processing, handling and storage. The oil fingerprint method is application if specific knowledge of petrochemicals and use if sophisticated analytical equipment and techniques to identify the source(s) if oil pollution. KCG currently utilizes four primary analytical techniques: Gas Chromatography (GC), Fluorescence Spectroscopy(FL), Infrared Spectroscopy(IR) and Gas Chromatography mass spectrometer(GC/MS). Of all these techniques, GC technique are most widely used Gas Chromatography is used as a primary analytical method because high reliableness, high separating efficiency and repeatability.

• Archives of Pharmacal Research
• /
• v.8 no.4
• /
• pp.261-266
• /
• 1985

Many monoterpen-erivatives are contained in edible plants. Some monoterpen-derivatives have been assessed as negative factors in the food safety. Among them thuone and 4-caranone are important toxic constituents of many plant essential oils. In this study, convenient detection methods of thujone and 4-caranone in oil were developed. The colour reactions of toxic thujone and 4-caranone were performed in oder to detect those in foods and oils. Sodium pentacyanonitrosylferrate (II) react with thujone to produce thujzoximinocarboxylic acid which becomes the six ligand in the ferrate complex (red colour reaction for thujone). Sodium pentacyanonitrosylferrate (II) cleaves 4-caranone to the red ferrate complex of caranketonic acid.