• Journal of Korean Society on Water Environment
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• v.20 no.6
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• pp.652-656
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• 2004

Both surface wash and backwash are considered as one of the most important methods that can improve the filtration efficiency in the existing water treatment plant. This study has mainly focused on the improvement of filtering efficiency by controlling surface wash and backwash time, and water level before backwash (when drained up to the trough, when drained up to 10 cm above filter bed, and when drained below 10 cm filter bed). Filtration efficiency was shown a little bit of differences depending on the operating conditions like surface wash injection pressure, the distance control between filter bed and the facility, and the types of surface wash. When the water level before backwash was reached up to 10 cm below filter bed after draining, however, the filtration velocity and the turbidity removal efficiency in the filter bed was improved. When the surface wash followed by backwash is longer, it showed a similar result. Because the proper adjustment of surface washing time makes filtration efficiency higher, therefore, it is necessary to set up the backwash time moderately.

• Textile Coloration and Finishing
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• v.11 no.6
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• pp.24-35
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• 1999

This study was carried out to investigate the changes of surface characteristics of polyester fabrics on the deposition and the removal of oily soils from polyester fabrics in detergency, The relations between the removal of soil and the changes of surface properties of polyester fabrics treated with water- and oil-repellent agents were discussed before and after various wash cycles. Two kinds of fluoropolymers were selected as water-and oil-repellent finishing agents. The effects of water- and oil-repellent finishes were determined by the water repellency and oil repellency. The surface properties of untreated and treated polyester fabrics were evaluated with respect to contact angle and wicking time. The treatment of polyester fabrics with fluoropolymers improved efficiently water repellency, oil repellency, contact angle and wicking time. But those properties were greatly decreased after 3 times of wash cycles in detergency The deposition of oily soils on the untreated fabrics was drastically increased with increasing of wash cycles. The deposition and the removal of oily soils from fabrics treated with fluoropolymer having hydrophobic components were very low after various wash cycles. The deposition and the removal of oily soils on the fabrics treated with fluoropolymer having hydrophilic components were high comparatively after various wash cycles. Even though the surface properties of treated fabrics were greatly decreased with the increasing of wash cycles, the remains of oily soils on the fabrics were lower than those of untreated fabrics in various wash cycles. But the remains of soils were drastically increased after 10 times of wash cycles in any cases.

• The Journal of Korean Academy of Prosthodontics
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• v.49 no.2
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• pp.138-144
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• 2011

Purpose: The purpose of this study was to evaluate the cleansing effect of recently developed alkaline ionized water, e-WASH, on microorganisms of the denture surface. Materials and methods: Removable partial and complete dentures were randomly assigned to the experimental group of 41 dentures, and the control group of 26. The denture was immersed in the e-WASH solution (experimental group), or tap water (control group) for 5 minutes. The plaque was collected from the denture surface before and after immersion, and smeared on the slide glass. Amount and motility of microorganisms were compared according to the morphology and strain of microorganisms, using the phase contrast microscope. Statistical analysis was accomplished with paired t-test and independent t-test at 95% confidence level (P<.05). Results: 1. The amount of cocci, bacilli, filamentous, spiral/comma, and the motility of bacilli, filamentous, and spiral/comma were decreased after denture cleansing with the alkaline ionized water, e-WASH (P<.05). But in the control group, only the amount of cocci showed a significant difference (P<.05), but no difference from the others. There were no differences in other analysis. 2. In the experimental group, the amount of cocci, bacilli, filamentous, spiral/comma, and the motility of bacilli, filamentous, and spiral/comma were smaller and more inactive compared to the control group (P<.05). Conclusion: These results indicated that the alkaline ionized water, e-WASH could effectively reduce the amount and motility of the experimented microorganisms on the denture surface, and that e-WASH could be recommended as an effective denture cleanser.

• Fibers and Polymers
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• v.4 no.3
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• pp.124-128
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• 2003

Dark brown Alpaca fiber was reduced in shade via selective bleaching with peroxide. Two selective oxidative bleaching methods were tested on alpaca top to assess their effectiveness for color removal and fiber quality properties. Color change, bundle strength, weight loss, fiber diameter, surface modification, dye-ability and dye wash fastness were assessed for both methods and compared with the original brown top. Bleach method 1 (BL-I) showed little surface modification, 5.8% weight loss and 2.4% strength loss. D1925 yellowness index was reduced to 74.3 from 83.1 and provided a good base for the dyeing of medium to deep shades. Bleach method 2 (BL-II) displayed considerable surface modification, 7.8% weight loss and 18% strength loss. BL-II also resulted in a mean diameter reduction of 1.9 micron during bleaching. Yellowness was reduced to 64.5 from 83.1 and provided a very good base for the dyeing of medium to deep shades. BL-I showed better exhaustion of the premetallised dye Lanaset Violet B than BL-II. Wash fastness for BL-II was 1 grey scale unit poorer than BL-I. BL-II showed far better color clarity at pale depths however the wash fastness of the finished product was not good enough to maintain the depth or clarity of the color. BL-I showed poorer clarity of color but exhibited better wash fastness results.

• 유체기계공업학회:학술대회논문집
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• 2006.08a
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• pp.357-360
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• 2006

In the present study, the air jet flow characteristics of the dryer in the automatic car wash machine were numerically predicted by commercial CFD code. The effects of the dryer shape and the nozzle width variations on the performance of the automatic car wash machine were discussed. To optimize the geometric parameters, the response surface method(RSM) with CFD was used. Predicted jet velocity distributions for the optimized geometry were compared with experimental data and the comparisons show generally good agreements. Also, the performance of the dryer was improved with the optimized results.

• Asian Journal of Atmospheric Environment
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• v.7 no.1
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• pp.1-7
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• 2013

To establish the method for investigating the behavior of aerosol particles deposited on the leaf surface against fog water under natural conditions, scanning electron microscopy with energy-dispersive X-ray (SEM-EDX) analysis and wash water analysis by ion chromatography after the washing treatment were performed using leaves of white birch collected from low part of the tree crown and the top of the tree in Sapporo City, Hokkaido, northern Japan. Each of collected leaves was divided into two parts according to the treatment performed: leaf surface (adaxial side) was 1) untreated, and 2) washed with deionized water with a pipette. In untreated samples, many particles of various shapes, including soil particles and organic debris, were deposited on the surface. Particles containing S were found on the surface of samples collected from only low part of the tree crown. After the washing treatment, SEM-EDX analysis revealed that soil particles and particles containing S had been washed off with water, although some particles such as soil particles and organic debris still remained on the leaf surface. The major anion such as $SO{_4}^{2-}$ was detected in wash water of all samples, although the peak of S in X-ray spectra was not detected from samples collected at top of the tree. The combination of SEM-EDX analysis with wash water analysis indicated that $SO{_4}^{2-}$ was deposited on the leaf surface in dissolved state and/or in state of submicron particles. These results suggested that fog water could remove soil particles and particles containing S and $SO{_4}^{2-}$ from the leaf surfaces, but not all particles. There was no difference in sampling position in the tree crown. Our study suggested that combination with SEM-EDX analysis and wash water analysis would be effective for investigation of the behavior of particles on the leaf surface against fog water.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.9
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• pp.1491-1497
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• 1997

The purpose of this research is to improve the surface roughness of cast-iron pipe porduced by the centrifugal casting. A twin-fluid atomizer of mold-wash slurry is designed for this project. New atomizer is equipped with the existing manufacturing facility to produce pipes. Cast-iron pipes (.cent.125*L3000mm) are produced and the surface roughnesses of those are analysed by UBM. The average surface roughness of new products is 6.7.mu.m while the old products of sand-resin coating method have 17.0.mu.m of average surface roughness. The surface roughness of cast-iron pipe is improved very much than before.

• The KSFM Journal of Fluid Machinery
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• v.10 no.5
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• pp.34-40
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• 2007

An optimization approach is investigated for the design of new nozzle system in a automatic car wash machine. Three-dimensional computational fluid dynamics and design of experiment methods have been employed to know the mutual interaction between the nozzle shape in the automatic car wash machine and the airflow velocity distribution on the vehicle surface. The performances of air nozzle system were defined as the velocity magnitude and the uniformity of the velocity on the surface of the car. Predicted jet velocity distributions for the optimized geometry were compared with experimental data and the comparisons showed generally good agreements. Also, the performance of the dryer was improved with the optimized results.

• 보존과학연구
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• s.24
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• pp.81-98
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• 2003

The biodeterioration on Iksan Mireuksaji pagoda has been studied with fucus on application of K201 as a chemical treatment. Total of 39species, including 10 algae, 16 lichens, 6 mosses and 7 unidentified bacteria and fungi, were collected and identified on the surface of the pagoda. Most of them caused serious discoloration on the surface. The effectiveness and stability of K201 was examined by applying it on some part of the pagoda. A mild spraying of solution diluted to half of original reagent was good enough to eliminate all the deteriorating species on the surface. Most of discoloration disappeared after the treatment except the red color caused by iron substance. The effectiveness of the regent was compared with water wash. The stone was first washed with water and the dirt on the surface was scrubbed off from the surface. The initial surface of the stone was clearer in water wash. However, many of the deteriorating species reappear in 4 weeks after water wash. Although spraying of the reagent K201 could noteliminate all the remnant of dead organisms as good as scrubbing the surface, no deteriorating algae or lichen was observed until two month after treatment. Therefore, spraying method with chemicals seems more stable and reliable way to remove the biodeterioration than physical scrubbing of the surface.

• Clean Technology
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• v.25 no.3
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• pp.256-262
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• 2019

Hydroxylammonium nitrate (HAN)-based liquid propellants are attracting attention as environmentally friendly propellants because they are not carcinogens and the combustion gases have little toxicity. The catalyst used to decompose the HAN-based liquid propellant in a thruster must have both low temperature activity and high heat resistance. The objective of this study is to prepare an Ru/alumina/metal foam catalyst by supporting alumina slurry on the surface of NiCrAl metal foam using a washing coating method and then to support a ruthenium precursor thereon. The decomposition activity of a HAN aqueous solution of the Ru/alumina/metal foam catalyst was evaluated. The effect of the number of repetitive coatings of alumina slurry on the physical properties of the alumina/metal foam was analyzed. As the number of alumina wash coatings increased, mesopores with a diameter of about 7 nm were well-developed, thereby increasing the surface area and pore volume. It was optimal to repeat the wash coating alumina on the metal foam 12 times to maximize the surface area and pore volume of the alumina/metal foam. Mesopores were also well developed on the surface of the Ru/alumina/metal foam catalyst. It was found that the metal form itself without the active metal and alumina can promote the decomposition reaction of the HAN aqueous solution. In the case of the Ru/alumina/metal foam-550 catalyst, the decomposition onset temperature was significantly lowered compared with that of the thermal decomposition reaction, and ${\Delta}P$ could be greatly increased in the decomposition of the HAN aqueous solution. However, when the catalyst was calcined at $1,200^{\circ}C$, the catalytic activity was lowered inevitably because the surface area and pore volume of the catalyst were drastically reduced and Ru was sintered. Further research is needed to improve the heat resistance of Ru/alumina/metal foam catalysts.