• The Journal of the Korean dental association
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• v.12 no.1
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• pp.37-42
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• 1974

To ascertain if the ultrasonic cleaning technique caused any dimensional changes in heat and cold curing and fluid resin denture bases and in addition to evaluate the dimensional changes of the resin denture bases stored in water and air, the author measured the distance between the outsides of two pins embedded in methyl methacrylate test denture bases by mean of 12 inch vernier caliper, accurate to 0.02mm. The results were as follows; (1) Ultrasonic cleaning didn't cause any permanent dimensional changes, but only affected temporary dimensional expansion in 16 test denture bases. (2) Temporary expansion rate caused by 10 minutes' ultrasonic cleaning was 0.29% and at the maximal temperature of the cleaning solution it was 0.64%. (3) The half of the denture bases stored in water showed the dimensional expansion rate of 0.47% while the others stored in air showed the dimensional shrinkage rate of 0.15% after 4 months.

• The Journal of Advanced Prosthodontics
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• v.7 no.2
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• pp.151-159
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• 2015

PURPOSE. To describe and characterize the surface topography and cleanliness of CAD/CAM manufactured zirconia abutments after steaming and ultrasonic cleaning. MATERIALS AND METHODS. A total of 12 ceramic CAD/CAM implant abutments of various manufacturers were produced and randomly divided into two groups of six samples each (control and test group). Four two-piece hybrid abutments and two one-piece abutments made of zirconium-dioxide were assessed per each group. In the control group, cleaning by steam was performed. The test group underwent an ultrasonic cleaning procedure with acetone, ethyl alcohol and antibacterial solution. Groups were subjected to scanning electron microscope (SEM) analysis and Energy-dispersive X-ray spectroscopy (EDX) to verify and characterize contaminant chemical characterization non- quantitatively. RESULTS. All zirconia CAD/CAM abutments in the present study displayed production-induced wear particles, debris as well as organic and inorganic contaminants. The abutments of the test group showed reduction of surface contamination after undergoing an ultrasonic cleaning procedure. However, an absolute removal of pollutants could not be achieved. CONCLUSION. The presence of debris on the transmucosal surface of CAD/CAM zirconia abutments of various manufacturers was confirmed. Within the limits of the study design, the results suggest that a defined ultrasonic cleaning process can be advantageously employed to reduce such debris, thus, supposedly enhancing soft tissue healing. Although the adverse long-term influence of abutment contamination on the biological stability of peri-implant tissues has been evidenced, a standardized and validated polishing and cleaning protocol still has to be implemented.

• 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

• Air Cleaning Technology
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• v.8 no.2 s.29
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• pp.48-70
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• 1995

• Korean Chemical Engineering Research
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• v.48 no.3
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• pp.401-404
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• 2010

A spray-type cleaning agent in utilizing dust-remover on PCB was chosen to study. In cleaning of electronic and semiconductor equipment, a substrate(IPC-A-36) was used to test the jet forces of the agent. And according to the jet forces time of the cleaning agent, the corresponding moving distances were compared with the spray times, and for the pollutants of iron powder and dust, the cleaning efficiency was tested with the IPC-A-36 by a weight method. The moving distance increased with the spray cleaning time longer. For a spray cleaning time of 3sec, the cleaning efficiency decreased with the amount of dust and the iron powder. It was also observed that the dust was remarkably removed, compared to the iron powder.

• Safety and Health at Work
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• v.13 no.4
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• pp.487-492
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• 2022

Objective: The exposure levels of disease-causing bacteria and germs were assessed on aircraft cleaning workers on multiple different aircrafts. Method: Five measuring points were selected depending on the aircraft types. Four aircraft cleaning agencies were selected for the test. Aircraft cleaning work was classified as intensive cleaning and general cleaning work. Ventilation in aircraft when sampling during the cleaning operation was categorized into forced ventilation and natural ventilation. The collection of airborne microorganisms was made through inertial impactors which were installed 1.5 meters above the bottom of the aircraft. The airborne bacteria and fungus growth badges were selected by Trytpic Soy Agar and Sabouraud Dextrose Agar. Results: The average concentrations of bacteria in the air were higher in the order of small, medium, and large airplanes. Rainy days had higher concentrations inside and outside the aircraft as compared to those in sunny days. Regarding ventilation, concentrations in natural ventilation were higher than concentrations in forced ventilation. According to the type of work, the concentrations in the intensive cleaning groups (cleaning one plane a day) were lower than those of the ordinary cleaning groups (cleaning several planes per day). Conclusion: The concentration levels of airborne bacteria and fungi in the aircraft surveyed were lower than the indoor environmental standards of Korea (800 cfu/m³ and 500 cfu/m³). The average concentrations of bacteria in the air and fungi in the air were highest in small aircraft owned by Company D.

• Journal of the Korean Society of Clothing and Textiles
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• v.12 no.2 s.27
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• pp.207-216
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• 1988

This study is to examine the cleaningproof by dry cleaning runs and parts(shoulder, belly, butt) of garment leathers tanned chrome. This study is composed of three methods of test; color difference test, surface view by scanning electron micrographs, mechanical properties measurement by KES-FB system. The results obtained were as follows: 1. In stiffening of parts of sample, the belly is the best degree in smoothness, fullness, softness. But that of the butt have been found to be the worst degree and to be thick. 2. In fading of parts, the shoulder is an extreme case, but the belly is the best among three parts. 3. In dry cleaning runs, the view after 3 runs has been found to be the best result. 4. The stiffening after dry cleaning 1 run have been low grade, for the sample absorb much solvent of dry cleaning. And, the fading and the decoloration are to be worse after 5 runs. Because the leather surface is affected by dry cleaning runs.

• Journal of the Korean Home Economics Association
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• v.20 no.4
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• pp.113-124
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• 1982

We have investited on the efficiency of the electric vacuum cleaners for household use. On this experiment, we have used the Expired Gas Analyer IHO6(SAN-EI, K.K) to get energy expenditure of house cleaning. The testing items are, (1) The difference of energy expenditure of cleaning for the each types of the test floors: Which are P-tile, Tatami, and 4 kinds of carpets. (2) The energy expenditure of cleaning for the room with a given quantity of furnitures: The volumes of furnitures are 0, 3, 10, 20% of the room with 2 kinds of chair. The results of the experiments are as follows. 1. The energy expenditure of cleaning for the types of test floors: Setting the energy expenditure on the basis of P-tile, Tatami needs 20~24% energy expenditure than P-tile, and carpet needs 60~64% energy expenditure than P-tile. 2. Cleaning time: The more the room has many furnitures, the more it takes longer. The types of vacuum cleaners, the Shoulder-type cleaner needs 1.19 times of the Upright-type, and the Cylender-type needs 1.08 times of the Upright-type. 3. The energy expenditure of cleaning for a given quantity of furnitures: The more the rooms has many furnitures, the more the energy expenditure increase. A 10% (20%) increases in the volume of the furniture causes a 100% (200%) increases in the energy expenditure of vacuum cleaners.

• Journal of Energy Engineering
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• v.28 no.1
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• pp.57-64
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• 2019

In this study, the blasting nozzle for surface treatment of the curved surface of parts in power plant industry was designed and the cleaning performance was examined through the compressible flow analysis. At this time, the outlet of the curved nozzle was designed as a curved surface along the surface of the part. After the nozzle was made by 3-D printing, the abrasive was sprayed on the surface of the cylindrical specimen and the cleaning performance test was performed. The effective cleaning area obtained after the analysis was similar to the size and shape of the effective cleaning area obtained after the experiment. From this, the validity and effectiveness of the curved nozzle design was confirmed.

• Nuclear Engineering and Technology
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• v.26 no.1
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• pp.140-148
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• 1994

A qualification test was performed for the iron removal chemical cleaning of the secondary side of nuclear steam generators at the selected temperature, 1$25^{\circ}C$, higher than the standard application temperature, 93$^{\circ}C$. The field cleaning condition for a nuclear unit was tested in a bench scale test loop including a SUS 316 stainless steel autoclave with one gallon capacity as a test vessel. The kinetics of sludge dissolution, corrosion of the secondary side materials and change of solvent chemistry were monitored. Test results indicated that more thorough cleaning was accomplished in less than half of the cleaning time required at 93$^{\circ}C$. And the total corrosions of the secondary side materials were found to be less than the values at 93$^{\circ}C$. While the solvent is recirculated and heated by an external chemical cleaning equipment for the conventional 93$^{\circ}C$ process, the secondary side is heated by the lateral heat of the primary coolant without the recirculation of the cleaning solution, and the solvent is mixed by vigorous boiling induced by periodic ventilation for the high temperature process. The requirement that the reactor coolant pumps should be running during the cleaning operation is the major disadvantage of the high temperature process which also should be considered when chemical cleaning is planned for steam generators under operation.