• Journal of Advanced Marine Engineering and Technology
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• v.38 no.10
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• pp.1251-1256
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• 2014

The use of lubrication oil is of many purposes and one among them is to drive the engine mounted on a ship. Hence the supply of clean lubrication oil is important. And an oil purifier is one of key components in marine diesel engines. At present, the element type full-flow oil filter has been widely used for cleaning the engine oil. The self-driven centrifugal oil purifier is a device which is used to remove the impurities in lubrication oil using a jet flow. The flow characteristics and the physical behaviors of particles in this self-driven oil purifier were investigated numerically and the filtration efficiencies were evaluated. For calculations, a Computational Fluid Dynamics method is used and the Shear Stress Transport turbulence model has been adopted. The Multi Frames of Reference method is used to consider the rotating effect of the flows. The influence of centrifugal forcehas been numerically investigatedto improve filtration efficiency of tiny particles. As a result of this research, it was found that the particle filtration efficiency using the only center axis rotating and outer wall rotating system are higher than that of the fully rotating system in the self-driven oil purifier.

• Journal of Microbiology and Biotechnology
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• v.14 no.3
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• pp.643-645
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• 2004

A $\beta$-xylosidase was purified from the culture of Trichoderma sp. SY. The ten-day-old culture filtrate was concentrated, followed by ion-exchange chromatography and gel filtration chromatography. As a result, $\beta$-xylosidase was finally purified about 53-fold and appeared as a single band by SDS-PAGE. The optimum pH and temperature were 5.0 and $55^{\circ}C$, respectively, and the molecular weight about 80 kDa. The purified $\beta$-xylosidase was found to be inhibited by various metal ions but not inhibited by xylose.

• Korean Journal of Pharmacognosy
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• v.21 no.4
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• pp.274-283
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• 1990

This study was conducted to further characterize mucilages from Dioscoreae Rhizoma, which have been known to be proteoglycans. We chose the two types of yams, Dioscorea batatas Dec. (club-like) and D. japonica Thunb. (cane-like). Repeated gel filtration of a dialyzed water extract of each fresh yam on Bio-gel P-100 and then Sephadex G-150 columns completely separated the mucilage from protein. Furthermore, gel filtration of a water extract from each yam processed by steaming and drying on the Bio-gel P-100 column gave only one polysaccharide peak without protein. These results revealed that the mucilages of yams were only composed of polysaccharide. Then we assessed some properties of the mucilages under three kinds of criteria: a complex-forming capacity between mucilage and alcian blue, mannose content in the mucilage, and viscosity. The complex-forming capacities of two types of fresh yams were closely similar with each other, but the processing of two types of the fresh yams greatly lowered the complex-forming capacity and viscosity.

• Journal of Environmental Science International
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• v.32 no.11
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• pp.801-809
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• 2023

The purpose of this study is to predict the reflection distance following to the pulsing pressure, total air supplying, filter bag size using numercial analysis techniques and use it as an efficient operation condition and economic data for off-line type pulse air jet bag filter. In this research, filtration area 6 m² condition, calculate filter resistance coefficient for simulation through the main experiments using coke dust. Ansys fluent V19.0 apply to CFD simulation, and analysis pulsing characteristics about pulsing pressure, filtration velocity and nozzle diameter. The maximum reflecting distance of off-line type pulse air jet bag filter is 1,000 mm regardless of total air supplying at over the 42 L/m² conditions, that indicates off-line type can extend filter bag length 1,000 mm than on-line type. In order to effective primary and secondary pulsing of off-line type pulse air jet bag filter, over the 5 bar of pulsing pressure and over the 42 L/m² of total air supplying are needed.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.05a
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• pp.237-240
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• 2005

The demand of micro electrical mechanical system (MEMS) bio/chemical sensor is rapidly increasing. To prevent the contamination of sensing area, a filtration system is required in on-chip total analyzing MEMS bio/chemical sensor. A nano-filter was mainly applied in some application detecting submicron feature size bio/chemical products such as bacteria, fungi and so on. We suggested a simple nano-filter fabrication process based on replication process. The mother pattern was fabricated by holographic lithography and reactive ion etching process, and the replication process was carried out using polymer mold and UV-imprinting process. Finally the nano-filter is obtained after removing the replicated part of metal deposited replica. In this study, as a practical example of the suggested process, a nano-dot array was replicated to fabricate nano-filter fur bacteria sensor application.

• Proceedings of the Materials Research Society of Korea Conference
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• 2009.11a
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• pp.18.2-18.2
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• 2009

Ceramics have some properties that are unmatched by other kind of materials like metals or polymers. The ability of high thermal and chemical resistance and in case of being superior in specific mechanical properties makes the ceramic materials suitable for arange of applications. The microstructure and morphology of a material arguably permit the use of many advanced application otherwise difficult to achieve.Porous structures have some important applications in biomedical and environmental field. For human hard tissue reconstruction and augmentation procedure suitable biomaterials are used with a desirable porosity. A range of porous bioceramics were fabricated with tailored design to meet the demand of specific applications. Channeled and interconnected porosity was introduced in alumina, zirconia, and hydroxyapatite or tri calcium phosphate ceramics by different methods like multi-pass extrusion process, bubble formation in viscous slurry,slurry dripping in immiscible liquid, sponge replica method etc. The detailed microstructural and morphological investigations were carried out to establish the unique features of each method and the developed systems. For environmental filters the porous structures were also very important. We investigated a range of channeled and randomly porous silicon based ceramic composites to enhance the material stability and filtration efficiency by taking advantage of the material chemistry of the element. Detailed microstructural and mechanical characterizations were carried out for the fabricated porous filtration systems.

• Journal of Korean Society on Water Environment
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• v.22 no.5
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• pp.865-870
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• 2006

The behavior and influence of EPS on membrane fouling by changing of hydraulic retention time was investigated, using lab. scale submerged membrane bio-reactor, which was operated with gravitational filtration and fed supernatant of primary sedimentation in waste water treatment plant as influent. The membrane was adopted micro-filter of polyethylene hollow fiber. EPS was analysed as polysaccharides and protein especially, into soluble and bound EPS separately. The concentration of soluble EPS was increased at short HRT, then membrane fouling was rapidly progressed and flux was depressed. The most of EPS clogged membrane pore were polysaccharides, while protein was important parameter affected on membrane fouling because of it's more accumulating in the more term operating.

• Membrane and Water Treatment
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• v.14 no.1
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• pp.11-18
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• 2023

This work addresses the development of microfiltration ceramic membrane from alumina using extrusion method. The membranes were sintered at different temperatures ranging between 1000 and 1300℃. The alumina was characterized with thermogravimetric analysis, particle size distribution, X-ray diffraction, Fourier transform infrared spectrometer and scanning electron microscope analysis. Subsequently, the effect of sintering temperature on the membrane properties such as porosity, flexural strength, and pure water permeability was investigated and optimized for the sintering temperature. It is observed that with increasing sintering temperature, the porosity of the membranes decreases and the flexural strength, and pure water permeability of the membranes increase. The uncoated and coated membranes were compared at constant flux mode of filtration. Under the turbidity solution recirculation alone at 100 NTU, trans-membrane pressure (TMP) of uncoated membrane remained constant when the filtration flux was below 121 Lm^-2 h ^-1 , while the coated membrane was 111 Lm_-2 h ^-1 . Although suction pressure increased more rapidly at higher turbidity, coated membrane filtration showed better removal efficiency of the turbidity.

• Membrane and Water Treatment
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• v.7 no.4
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• pp.313-325
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• 2016

South Africa recognises piped water as the main source of safe drinking water supply. Remote areas do not have access to this resource and they rely solely on surface water for survival, which exposes them to waterborne diseases. Interim point of use solutions are not practiced due to their laboriousness and alteration of the taste. Bio-ultra low pressure driven membrane system has been noted to be able to produce stable fluxes after one week of operation; however, there is limited literature on South African waters. This study was conducted on three rivers namely; Umgeni, Umbilo and Tugela. Three laboratory systems were setup to evaluate the performance of the technology in terms of producing stable fluxes and water that is compliant with the WHO 2008 drinking water guideline with regards to turbidity, total coliforms and E.coli. The obtained flux rate trends were similar to those noted in literature where they are referred to as stable fluxes. However, when further comparing the obtained fluxes to the normal dead-end filtration curve, it was noted that both the Umbilo and Tugela Rivers responded similarly to a normal dead-end filtration curve. The Umgeni River was noted to produce flux rates which were higher than those obtainable under normal dead-end. It can be concluded that there was no stabilisation of flux noted. However, feed water with low E.coli and turbidity concentrations enhances the flux rates. The technology was noted to produce water of less than 1 NTU and 100% removal efficiency for E.coli and total coliforms.

• Journal of Wetlands Research
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• v.16 no.3
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• pp.347-353
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• 2014

This work was performed to find the effect of operation parameters on the permeate flux through the activated sludge dynamic layer, and to indicate the relationship between the water quality of supernatant and flux based on the results. Since the effluent can be obtained through steady and stable formation of cake layer in the bio-filter media system, it is an important subject to keep and control microbes with activated state in the bio-reactor. Filtration resistance was drastically increased at more than 18000mg/L of MLSS. With filtration time continued, the flux was gradually decreased and the water qualities of supernatant monitored by turbidity and TOC were also deteriorated. This phenomenon indicated that the organic materials generated by microbes and accumulated in the reactor might affect the flux in the system. In addition, the decrease of flux was simultaneously observed in the sludge volume index. When SVI was controlled from 150 to 250, the flux was also decreased. The proper aeration time was recommended to 30 to 60 seconds in this system. In order to operate this system steadily, therefore, the control of water quality of supernatant and SVI should be proceeded.