• Journal of Power System Engineering
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• v.15 no.6
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• pp.16-21
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• 2011

Over the past years, many research works have been carried out to investigate the factors which govern the performance of diesel engine. The air pollutant emission from the diesel engine is still a significant environmental concern in many countries. In the present study, new system of smoke filtration of diesel engine is proposed. This new system is using vacuum equipment and filter for capture smoke. To verification new system experiments are performed at diesel vehicle and engine dynamometer. As a result it is founded that smoke is decreased of 67% at vehicle test and decrease of 45.2% at full load condition of engine dynamometer test.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.20 no.12
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• pp.820-824
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• 2008

Electret filter media are used in general ventilation filters, disposable respirators, vehicle cabin filters, vacuum cleaners and room air cleaners. There are basic mechanisms of interception, inertial impaction, diffusion, gravitational settling, electrostatic attraction by which an aerosol particle can be deposited onto a fiber in a filter. The ability of fine particle removal strongly depends on the electrostatic forces between particles and polarized fibers. Thus, the stability of the fiber polarization is a major factor in the reliability of electret filters. In this study, the electret filter is made by electrospinning process using Polystyrene which is dissolved by 5 : 5 of Tetrahydrofuran (THF) and Dimethylformamide (DMF). Also the electrical properties and the filtration performances of electrospun filter media are Quantitatively investigated. Electrical properties of electrospun filters have been studied on surface charge potential and surface charge density. Also the filtration performance of the electret filters are evaluated on collection efficiency. The surface charge potential and the surface charge density of electrospun PS filters are increased with increasing applied voltage and saturated at 30 kV of applied voltage. Also collection efficiency of electro spun filters is increased with increasing surface charge potential and surface charge density. But the surface charge potential is decreased by natural decay and it causes deterioration of particle collection efficiency.

• Membrane Journal
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• v.33 no.4
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• pp.201-210
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• 2023

Dust filter membranes play a crucial role in human life and various industries, as they contribute to several important aspects of human health, safety, and environmental protection. This study presents the development of a polysulfone@polyphenylene sulfide/polytetrafluoroethylene (PSf@PPS/ePTFE) composite dust filter membrane with excellent thermal stability and adhesion properties for high-temperature conditions. FT-IR analysis confirms successful impregnation of PSf adhesive onto PPS fabric and interaction with ePTFE support. FE-SEM images reveal improved fiber interconnection and adhesion with increased PSf concentration. PSf@PPS/ePTFE-5 exhibits the most suitable porous structure. The composite membrane demonstrates exceptional thermal stability up to 400℃. Peel resistance tests show sufficient adhesion for dust filtration, ensuring reliable performance under tough, high-temperature conditions without compromising air permeability. This membrane offers promising potential for industrial applications. Further optimizations and applications can be explored.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.3 no.3
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• pp.1-7
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• 1983

In spite of extensive knowledge of the surface chemistry and the transport mechanism in filtration systems, there is still insufficient understanding of the physical characteristics of suspensions and the system components. Because of this, no filtration mechanisms are mathematically generalized to the full extent. The purpose of this paper is to propose experimental equations for the filtration process. using the tracer study in filter layer. Some of results are as follows. (1) The Volume of the specific deposit (${\sigma}$) in filtration was directly measurable using the tracer study without interrupting the filtration. (2) It was also confirmed that the head loss in filtration was greatly in fluenced by the micro-air babbles. (3) The correction coefficient(f) was introduced into the Kozeny-Carman equation in order to apply it for the clogging filter media. The coefficient(f) was experimentally obtained. The total head loss of the filter media is given by next equation. $${\frac{h}{h_0}}={\frac{1}{L}}{\int}^{z=L}_{z=0}f({\sigma})g({\varepsilon}_0,{\sigma})dz$$ $$f=aexp(-b{\sigma})$$ The above equation was applicable without regard to the variation of the suspension concentration, the filter medium diameter, the filter depth, the filtration velocity, and the amount of aluminum in all continuous filtration experiments. (4) The total head loss was graphically generalized assuming mathematical filtration models I II (see fig. 7,8) (5) The total head loss was obtained from the filtration model in the field filtration conditions. (see fig. 9,10)

• Medical Lasers
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• v.8 no.2
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• pp.43-49
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• 2019

The plume produced by vaporizing tissue with a laser contains a variety of contaminants called laser-generated air pollutants (LGACs). LGACs consist of a mixture of toxic gas components, biomicroparticles, dead and living cells, and viruses. Toxic odors and thick smoke from surgical incisions and the coagulation of tissues can irritate eyes and airways, as well as cause bronchial and pulmonary congestion. Because of the potential risk of the smoke, it is advisable to appropriately remove it from the surgical site. We recommend using a smoke evacuator to remove the smoke. Suction nozzles should be placed as close as possible to the surgical site in a range of 2 cm or less. In-line filters should be used between the inlet and outlet of the surgical site. All air filtration devices should be capable of removing particles below 0.1 microns in size. The filter pack should be handled according to infection control procedures in the operating room. The laser mask can be an auxiliary protective device if it is properly worn. Some smoke inhaled under the nose wrap or over the side of the mask will not be filtered. As in electrosurgical operations, a suitable mask should be worn while smoke is present.

• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.5
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• pp.146-152
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• 2007

Recently, The air pollution problems become hot issues as the production of the diesel automotive increases. The ministry of environment has enforced a precise inspection law to decrease the vehicle emission. In this circumstances, the smoke measurement is somewhat complicated by the use of the different type smoke meters. Although the paper filtration type opacimeter has been used for measuring smoke widely but currently the light extinction type is being used for precise inspection law. These two type opacimeters are different in their measuring principles on each other. So, for the time being the regulation standards can be confused by these two type opacimeters. In this article, The correlation factor between these two type opacimeters is studied by using engine dynamometer and vehicle test. The result of the dynamometer test shows the light extinction type is more sensitive than the filtration type by 1.47 times. But the relation factor by the vehicle test achieved 1.37 value, which is lower than that of the dynamometer test. In the future study the more precise research is needed to estimate the relation factor on vehicle test.

• Journal of Microbiology and Biotechnology
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• v.16 no.6
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• pp.863-869
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• 2006

The behavior of submerged membrane bioreactor (SMBR) filtration systems utilizing rapid air backpulsing as a cleaning technique to remove reversible foulants was investigated using a genetic algorithm (GA). A customized genetic algorithm with suitable genetic operators was used to generate optimal time profiles. From experiments utilizing short and long periods of forward and reverse filtration, various experimental process parameters were determined. The GA indicated that the optimal values for the net flux fell between 263-270 LMH when the forward filtration time ($t_f$) was 30-37 s and the backward filtration time ($t_b$) was 0.19-0.27 s. The experimental data confirmed the optimal backpulse duration and frequency that maximized the net flux, which represented a four-fold improvement in 24-h backpulsing experiments compared with the absence of backpulsing. Consequently, the identification of a region of feasible parameters and nonlinear flux optimization were both successfully performed by the genetic algorithm, meaning the genetic algorithm-based optimization proved to be useful for solving SMBR flux optimization problems.

• Journal of Environmental Health Sciences
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• v.27 no.2
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• pp.30-36
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• 2001

This review begins with a brief expression of aerosol capture mechanism of fibrous filter(s) and performance of particulate removing respirators. The more complicated and detailed discussion is not included in this articles. Filtration efficiency and pressure drop are introduced as quality factor ( $q_{F}$) and the way in which filtration efficiency varies with particle size is discussed. Quality factors fro filters recently certified in USA were found to be very higher than those of filters made in Korea, China and USA filters certified with old certified standards. Electrically charged filters are widely used because they have high filtration efficiency and low pressure drop, but their efficiency decreases sharply at the condition occurring wet and oil mist. A discussion is given of respirator leakage through face seal and filter media with fit testing and total inward leakage testing. Since fit factor (FF) refers to the reciprocal of the fraction of the total air entering a respirator through face seal leakage , the degree of fitting performance for respirators is expected with FF. Because respirators made in Korea had generally lower FFs than respirators made in USA, it is necessary to develope respirators that fit properly for Koreans or establish regulations for fit testing.g.

• The KSFM Journal of Fluid Machinery
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• v.15 no.2
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• pp.20-29
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• 2012

The green house on the waterfront is air-conditioned by a water-source heat pump system with riverbank filtration water. In order to supply riverbank filtration water in alluvium aquifer, the riverbank filtration facility for water intake and recharge, two pumping wells and one recharge well, has been constructed. The research site in Jinju, Korea was chosen as a good site for riverbank filtration water supply by the surface geological survey, electrical resistivity soundings, and borehole surveys. In the results of two boreholes drilling at the site, it was revealed that the groundwater table is about 3 m under the ground, and that the sandy gravel aquifer layer in the thickness of 6.5 m and 3.5 m occurs at 5 m and 7 m in depth below the ground level respectively. To prevent the recharge water from affecting the pumped water which might be used as heat source or sink, the distance between pumping and recharge wells is designed at least 70 m with a quarter of recharged flow rate. It is predicted that the transfer term, the recharge water affects the pumping well, is over 6 months of heating season. Hydrogeological simulation and underground water temperature measurement have been carried out for the pumping and recharge well positions in order to confirm the capability of sustainable green house heating and cooling.

• Korean Chemical Engineering Research
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• v.53 no.4
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• pp.482-488
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• 2015

Biological treatment is promising alternative to conventional air pollution control method. Bioreactors for air pollution control have found most of their success in the treatment of dilute and high flow waste air streams containing volatile organic compounds and odor. The studies of mass transfer in biotrickling filters for air pollution control were of importance in order to control and optimize the purification process. The objectives of this study were to develop the experimental methodologies to evaluate the mass transfer coefficients of gas/liquid(trickling liquid), gas/solid(biomass) and liquid/solid in three phase biotrickling filtration. Also, this study characterized the influence factors on mass transfer such as dynamic holdup volume, gas/liquid flow rate ratio, biomass weight in reactor and recirculation rate of trickling medium for each phase of biotrickling filter.