• Journal of Environmental Science International
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• v.25 no.6
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• pp.817-827
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• 2016

The resistance in series model has been frequently used for determination of various filtration resistance to correctly understand the membrane fouling behaviour in MBR (membrane bio-reactor) for wastewater treatment. The cake layer resistance ($R_c$) which is commonly determined by calculation of flux dataset that are obtained empirically before and after removing the cake layer on membrane surface. However, the calculated Rc values are very dependent on the cleaning methods adapted for removal of cake layer. This study investigated how the various cleaning options affect $R_c$. Seven different cleaning methods were employed: i) ultrasonication (100 W, 10 min), ii) ultrasonication (200 W, 60 min), iii) ultrasonication (400 W, 120 min), iv) water rinsing in a shaker (100 rpm, 10 min), v) water rinsing in a shaker (300 rpm, 60 min), vi) water rinsing, vii) sponge scrubbing. For the hydrophilic PES membrane, the cake layer removal efficiencies ranged from 64% to 10%, indicating that the removal of cake layer was highly dependent on the cleaning options. For the hydrophobic PVDF membrane, the cake layer removal efficiencies ranged from 79% to 97%. Consequently, a standardized method for cake layer removal to determine cake resistance ($R_c$) is needed for correct interpretation of the fouling phenomena.

• Air Cleaning Technology
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• v.11 no.2 s.41
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• pp.40-49
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• 1998

• Journal of the Korean Home Economics Association
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• v.20 no.3
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• pp.55-63
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• 1982

We are studying on the home economics, particularly tools and machines used in household affairs. The object of this paper is to rationalize house cleaning method and to improve the used cleaning tools. We have made a social survey in Korea about the real situation of house cleaning as the first phase of this research. The contents are as follows: 1) The consciousness of housemakers for house cleaning. 2) The methods of house cleaning. 3) The used type of vacuum cleaner. 4) Merits and demerits of vacuum cleaner. 5) Troubles of vacuum cleaner etc. The results has been made in comparison with the same social survey in japan and a small scale different survey in The United States of America by auther in 1979. The results are as follow (in Korea). 1. The almost of housemakers are affirmative in charge of household affairs(95%). 2. In household affairs, only 9% of housemakers dislike cleaning work, but 40% of housemakers do not a cleaning work as a daily periodically. 3. In general household, they do a cleaning work with broom, duster and dust cloth, and then the cleaning work is faily backward in mechanization(The possession of vacuum is 19%). 4. The main dissatisfaction of vacuum cleaner is a noise, and also the difficulty of the cleaning in a corner of the room is shown in high percentage too.

• Journal of Food Hygiene and Safety
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• v.38 no.4
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• pp.228-235
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• 2023

Peanut is a well-known food allergen that causes adverse reactions ranging from mild urticaria to life-threatening anaphylaxis. Consumers suffering from peanut allergies should thus avoid consuming undeclared peanuts in processed foods. Therefore, effective cleaning methods are needed to remove food allergens from manufacturing facilities. To address this, wet cleaning methods with washing water at different temperatures, abstergents (peracetic acid, sodium bicarbonate, dilute sodium hypochlorite, detergent), and cleaning tools (brush, sponge, paper towel, and cotton) were investigated to remove peanuts from materials used in food manufacture, including plastics, wood, glass, and stainless steel. Peanut butter was coated on the surface of the glass, wood, stainless steel, and plastic for 30 min and cleaned using wet cleaning. The peanut residue on the cleaned surfaces was swabbed and determined using an optimized enzyme-linked immunosorbent assay (ELISA). Cleaning using a brush and hot water above 50℃ showed an effective reduction of peanut residue from the surface. However, removing peanuts from wooden surfaces was complicated. These results provide information for selecting appropriate materials in food manufacturing facilities and cleaning methods to remove food allergens. Additionally, the cleaning methods developed in this study can be applied to further research on removing other food allergens.

• Journal of the Korean Society of Clothing and Textiles
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• v.18 no.5
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• pp.674-681
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• 1994

In this study, four kinds of vapor-permeable waterproofed fabrics were selected and their properties and the changes of properties were investigated after laundering, petroleum drycleaning or tetrachloroethylene drycleaning (each 1, 5, 10 times). The results were as follows: 1) In the water resistance, only Gore Tex satisfied its minimum property requirements, $1.0kg/cm^2$ It decreased after laddering and drycleaning. Hipora-1000, Hipora-2000, Aitac decreased slightly by petroleum drycleaning and Gore Tex decreased slightly by all three methods. 2) In the moisture vapor transmission, three except Hipora-2000 satisfied its minimum property requirement, $4000g/m^2{\cdot}24hr$.24hr. After laundering and drycleaning, it increased regardless of cleaning methods. 3) In the water repellency, Hipora-lOOG, Hipora-2000 were not almost decreased after laundering and drycleaning. Aitac decreased slightly by petrolem drycleaning and Gore Tex decreased slightly by laundering and petroleum drycleaning. 4) Air permeability of Aitac increased with increasing of cleaning times regardless of cleaning methods. 5) In the bond strength, only Gore Tex dissatisfied its minimum property requirements, 250g/cm. Regardless of cleaning method, bond strength decreased with increasing of cleaning times. 6) Color difference was large in case of Hipora-1000 by laundering, Hipora-2000 by laundering and tetrachloroethylene drycleaning Aitac by tetrachloroethylene drycleaning, Gore Tex by laundering. To diminish property change of vaper-permeable waterproofed fabric, petroleum drycleaning is more effective than laundering and tetrachloroethylene drycleaning.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.3
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• pp.795-801
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• 2010

As the fabrication technology of LCDs (Liquid Crystal Displays) advances, the size of mother glass substrates is getting larger, and the fabrication process is becoming finer. Accordingly, the importance of cleaning processes grows in the fabrication process of LCDs. In this study, we have compared and evaluated the particle removal efficiency for three different methods of physical cleaning, which are brush, bubble jet, and aqua/air cleaning. Using the seventh generation glass substrate, the particle removal efficiency has been investigated by changing operation conditions such as a flow rate of deionized water, pressure, contact depth between a brush bristle and a glass substrate, and so forth. In the case of brush cleaning, the cleaning efficiency barely changes after a critical point when the contact depth is varied. While the cleaning efficiency of bubble jet cleaning is almost independent of pressure, that of aqua/air cleaning is affected by pressure up to a critical point, but is not changed after it. We note the brush cleaning is the most effective among the three cleaning methods under our experimental conditions.

• Journal of the Korea Society of Computer and Information
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• v.14 no.11
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• pp.31-40
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• 2009

The most common cleaning methods of cleaning robot can be divided into two categories: the random and the boustrophedon method. A cleaning robot using the random method moves straight until it bumps into an obstacle. If it collides with an obstacle, the cleaning robot turns a specific angle and continues moving straight. Therefore, the random method often tends to clean the already clean area repeatedly. In addition, it takes a long time to complete cleaning. A cleaning robot using the boustrophedon method moves straight until it collides with an obstacle. If it meets an obstacle, the cleaning robot moves to the next uncleaned space through turning and moving ahead. when resuming cleaning from the new region, a cleaning robot moves in the direction opposite to the direction of the previous cleaning. Because the boustrophedon method cleans a cleaning space more densely, its performance is excellent in an obstacle-free space or a small space. However, In a space with obstacles or a complex structure, it takes a long time to complete the cleaning work. Cleaning should be systematically approached with a good understanding of the work area. The virtual map-based cleaning robot proposed in this paper cleaned a work space efficiently. The efficiency of the proposed method was measured through simulation.

• Journal of the Korean Applied Science and Technology
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• v.41 no.1
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• pp.19-26
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• 2024

Recently, separation membranes have been applied to fields such as water supply, sewage treatment, gray water reuse, and air pollution control. Chemical cleaning technology is attracting attention among the methods of reusing these expensive separation membranes. It was found that the separation membrane could be regenerated using chemical cleaning. Specifically, it was found that the use time of the separation membranes regenerated by chemical cleaning was sustainable for more than 1,700 hours. Additionally, it was found that the flux recovery ratio after chemical cleaning was maintained at least 60%. In addition, the flux recovery ratio of HYDREX 4710, an organic membrane cleaner, and 4703, an inorganic membrane cleaner, was 76% and 62%, respectively, showing the highest flux recovery ratio among the chemicals used. Considering that the target raw water of this study is biological secondary treatment water, it was suggested that chemical cleaning could be actively used to regenerate separation membranes in future water treatment.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.88-89
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• 2009

In this paper, we investigated about wet cleaning effect as deep trench formation methods for Power chip devices. Deep trench structure was classified by two methods, PSU (Poly Stick Up) and Non-PSU structure. In this paper, we could remove residue defect during wet. cleaning after deep trench etch process for non-PSU structure device as to change wet cleaning process condition. V-SEM result showed void image at the trench bottom site due to residue defect and residue component was oxide by EDS analysis. In order to find the reason of happening residue defect, we experimented about various process conditions. So, defect source was that oxide film was re-deposited at trench bottom by changed to hydrophobic property at substrate during hard mask removal process. Therefore, in order to removal residue defect, we added in-situ SCI during hard mask removal process, and defect was removed perfectly. And WLR (Wafer Level Reliability) test result was no difference between normal and optimized process condition.

• The Journal of Advanced Prosthodontics
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• v.4 no.4
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• pp.192-196
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• 2012

PURPOSE. The purpose of this study was to evaluate the effect of provisional cement removal by different dentin cleaning protocols (dental explorer, pumice, cleaning bur, Er:YAG laser) on the shear bond strength between ceramic and dentin. MATERIALS AND METHODS. In total, 36 caries-free unrestored human third molars were selected as tooth specimens. Provisional restorations were fabricated and cemented with eugenol-free provisional cement. Then, disc-shaped ceramic specimens were fabricated and randomly assigned to four groups of dentin cleaning protocols (n = 9). Group 1 (control): Provisional cements were mechanically removed with a dental explorer. Group 2: The dentin surfaces were treated with a cleaning brush with pumice Group 3: The dentin surfaces were treated with a cleaning bur. Group 4: The provisional cements were removed by an Er:YAG laser. Self-adhesive luting cement was used to bond ceramic discs to dentin surfaces. Shear bond strength (SBS) was measured using a universal testing machine at a 0.05 mm/min crosshead speed. The data were analyzed using a Kolmogorov Smirnov, One-way ANOVA and Tukey HSD tests to perform multiple comparisons (${\alpha}$=0.05). RESULTS. The dentin cleaning methods did not significantly affect the SBS of ceramic discs to dentin as follows: dental explorer, pumice, cleaning bur, and Er:YAG laser. CONCLUSION. The use of different cleaning protocols did not affect the SBS between dentin and ceramic surfaces.