• Journal of Adhesion and Interface
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• v.14 no.1
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• pp.21-27
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• 2013

Cellulose-based rayon fibers or fabrics can be thermally decomposed very fast within a narrow temperature window during stabilization process. Therefore the stabilization stage is critically important for producing rayon-based carbon fibers. Consequently, in the present study the effects of isothermal stabilization and ultrasonic cleaning on the weight loss, chemical composition, microstructure, and fabric texture of cellulose-based rayon fabrics were explored. The temperature of the isothermal stabilization process performed in the range of $200{\sim}240^{\circ}C$ influenced the processing time, carbon and oxygen contents, cellulose structural change, and fabric texture. The ultrasonic cleaning, which was conducted prior to the stabilization process, played a role in shortening the stabilization time, increasing the carbon contents, decreasing the oxygen contents, and changing the XRD pattern. Also, it was considered that the ultrasonic cleaning contributed to retarding the weight loss, to reducing the thermal shrinkage, and further to reducing the fast physical change of rayon fabrics.

• Journal of Adhesion and Interface
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• v.14 no.3
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• pp.146-159
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• 2013

In the present study, stabilized rayon fabrics were prepared from fast isothermal stabilization processes, which were carried out within four minutes at $350^{\circ}C$. The effects of ultrasonic cleaning and chemical pre-treatment on the chemical composition, physical characteristics, X-ray diffraction pattern, thermal stability and shape of the stabilized rayon fabrics were investigated extensively. In order to reduce the weight loss and thermal shrinkage of rayon fabrics occurring during the stabilization process, ultrasonic cleaning was first conducted and then chemical pre-treatments using $NH_4Cl$, $Na_3PO_4$, $H_3PO_4$, and $ZnCl_2$ were performed, respectively. The results indicated that both ultrasonic cleaning and chemical pre-treatment influenced the weight loss, thermal shrinkage, microstructure, carbon content, thermal stability and fabric shape of stabilized rayon fabrics. Also the results depended on the fast-stabilization time and the type of chemical pre-treatment agents used.

• Journal of radiological science and technology
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• v.41 no.3
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• pp.241-247
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• 2018

The purpose of this study was to compare the ultrasound gel container washing methods for the sterilization of contaminants and to find the useful methods for the prevention of infection caused by the ultrasonic gel containers. In this experiment, a 250 mL ultrasonic gel container was used, and the ultrasonic gel used was a non-sterile gel (ECO GEL 99, SeungWon Medical, Korea). In order to evaluate the degree of contamination, new 250 mL 15 containers were divided into 5 groups to perform five types of washing by no treatment, washing with water, washing with soap, washing with bottle cleaner and high disinfection level washing. After the washing process, filled the gel container with gel and after 2 weeks, the number of colonies in the gel container was sampled repeatedly twice in the same ultrasonic laboratory and compared before and after washing. As a result of among the five cleaning methods used in this study, 87.2% and 88.9% of the soapy water washing (p = 0.028) and high level washing (p = 0.027) showed significant bacterial reduction rates, respectively. Our findings conclusively an ultrasonic gel container cleaning method for removing contaminants has been found to be an effective sterilization method at a low cost with a soapy water cleaning method. Therefore, it is expected that it will be helpful to prevent the infection caused by the ultrasonic gel container by suggesting the sterilization cleaning method that is practically useful in this study.

• The Journal of Advanced Prosthodontics
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• v.14 no.5
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• pp.273-284
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• 2022

PURPOSE. Computer-aided design and manufacturing (CAD-CAM) of implant abutments has been shown to result in surface contamination from site-specific milling and fabrication processes. If not removed, these contaminants can have a potentially adverse effect and may trigger inflammatory responses of the peri-implant tissues. The aim of the present study was to evaluate the bacterial disinfection and cleaning efficacy of ultrasonic reprocessing in approved disinfectants to reduce the microbial load of CAD-CAM abutments. MATERIALS AND METHODS. Four different types of custom implant abutments (total N = 32) with eight specimens in each test group (type I to IV) were CAD-CAM manufactured. In two separate contamination experiments, specimens were contaminated with heparinized sheep blood alone and with heparinized sheep blood and the test bacterium Enterococcus faecium. Abutments in the test group were processed according to a three-stage ultrasonic protocol and assessed qualitatively and quantitatively by determination of residual protein. Ultrasonicated specimens contaminated with sheep blood and E. faecium were additionally eluted and the dilutions were incubated on agar plates for seven days. The determined bacterial counts were expressed as colony-forming units (CFU). RESULTS. Ultrasonic reprocessing resulted in a substantial decrease in residual bacterial protein to less than 80 ㎍ and a reduction in microbiota of more than 7 log levels of CFU for all abutment types, exceeding the effect required for disinfection. CONCLUSION. A three-stage ultrasonic cleaning and disinfection protocol results in effective bacterial decontamination. The procedure is reproducible and complies with the standardized reprocessing and disinfection specifications for one- or two-piece CAD-CAM implant abutments.

• Fashion & Textile Research Journal
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• v.25 no.3
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• pp.386-397
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• 2023

In this study, the efficacy of ultrasonic washing in cotton and wool fabrics was compared and evaluated against conventional washing in terms of cleaning properties and fabric deformation. Factors such as washing temperature, time, liquid ratio, and detergent concentration were kept varied, and the cleaning properties of sebum-soiled fabrics were assessed using different detergents such as alcohol ethoxylate, linear alkylbenzenesulfonate, and IEC 60456 Reference Detergent A^*. In addition, the effects and emulsification power of enzymes and oxygen bleach were examined. To compare the cleaning properties with general washing, a launder-O-meter was used. To investigate fabric deformation during the washing process, the loosening test cloth, shrinkage test cloth, and mechanical strength test cloth were compared between ultrasonic washing machines and household drum washing machines. The results indicate that ultrasonic washing exhibits superior cleaning properties than launder-O-meter when the temperature is low and the washing time is short. Furthermore, there is less deformation and damage during the washing process. It was also observed that the activity of the detergent increases when ultrasonic waves are applied to the washing process. Considering the increasing tendency to pursue convenience and simplicity in clothing management as well as the anticipated commercialization of smart clothing with built-in electric circuits, ultrasonic laundry could serve as a new alternative to existing laundry methods.

• Journal of Korean Ophthalmic Optics Society
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• v.18 no.2
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• pp.101-106
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• 2013

Purpose: This research was to evaluate the sterilization effectiveness for bacterial contamination by general cleaning method of glasses for vision correction. Methods: From 82 eyeglass wearers the number of bacteria before and after cleaning was counted to check the status of the eradication. Results: The results after ultrasonic cleaning by using the tap water did not showed change of bacterial species. Ultrasonic cleaning using the 70% rubbing alcohol showed cleaning of 46.2% of bacteria. Ultrasonic cleaning using the 70% rubbing alcohol after brushing with general detergent showed clearing of 85.7% of bacteria. Conclusions: When glasses were brushed with a detergent, opportunities infectious bacteria in glasses for vision correction were removed effectively. These results can be suggested as a guideline for management of clean glasses.

• Journal of Korean Dental Science
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• v.3 no.2
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• pp.26-33
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• 2010

We searched at the "PubMed.gov" and "jendodon.com" sites to conduct a literature review on dental instruments that are reused in clinical settings and on infection control involving pre-disinfection or sterilization cleaning/rinsing. The keyword "dental clean" was used for the Web search. We found the present official definition of instrument cleaning performed prior to disinfection or sterilization rather limiting ("removal of foreign matter (soil, organism, etc.) from the instruments"). Thus, we proposed to expand the definition to include the removal of oils applied to protect the metallic instruments and from corrosion, stains, and rust resulting from the frequent reuse of the instruments. Clinicians are found to clean their dental instruments (a) immediately after treating their patients or (b) following their treatment but not immediately afterward. In the latter case, we recommend presoaking to be added. Ultrasonic sterilization of 5~15 minutes is found to be more effective in terms of eliminating residual matter from the instruments compared to other methods. To check on the cleaning results, we recommend visual inspection, which can be quick and practical in clinical settings. The latest products being developed and marketed on the market address the related problems. Nonetheless, research must be continued on the effects of presoak, cleaning/rinsing, disinfection, and high-temperature or heating-based sterilization on the dental instruments and on dental clinicians' practices in cleaning, disinfection, and sterilization. We advise dental clinicians to select the proper cleaning methods and detergents for their instruments to help eliminate or prevent corrosion, staining, and rusting, to reduce the maintenance costs, and to ensure user-friendly instruments/apparatuses.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.295-303
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• 2022

Residential heating systems in South Korea are largely based on the use of ondol pipelines. Heat is transferred to the floor by passing hot water through a metal or plastic pipe buried within the concrete of the floor. Consequently, it is difficult to clean the inside of these pipes after installation. Over time, foreign substances such as scale accumulate in the pipe when the ondol heating method is used for an extended period. Therefore, in the past, pipes were cleaned by removing foreign substances attached to the inside surfaces of the pipes using high-pressure water or by disassembling the pipes and removing foreign substances with chemical agents. Recently, a method for removing foreign substances through the cavitation effect of ultrasound has been proposed. This idea might lead to the development of new technologies for cleaning pipe interiors. Consequently, this study investigated the use of ultrasound to clean pipes embedded in concrete. In this study, devices that generated ultrasonic waves with various frequencies and directions were prepared. After preparing arbitrarily contaminated pipes, the appropriate frequency, output strength, and output direction for each foreign substance were determined through repeated experiments. The results of this experiment could provide important information for future methods of cleaning the interior of ondol piping systems.

• Clean Technology
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• v.19 no.3
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• pp.219-225
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• 2013

Environment-friendly and surfactant-free aqueous cleaning agents have been developed in order to solve various problems generated by surfactants in the aqueous cleaning agents. Aqueous surfactant-free cleaning agents, S-1 and S-2 have been formulated with water-soluble solvents such as propylene glycol and propylene glycol ether on their main components and with some additives. These solvents were chosen because of their good solubility in water and excellent solubility of fluxes which are major contaminants of printed circuit board in the electronic industry. Physical properties of the formulated and the imported cleaning agents were measured to predict their cleaning performance, and their cleaning abilities of flux and solder contaminants were evaluated under the various ultrasonic frequencies by a gravimetric method. The measurement results show that the physical properties of cleaning agent V are generally similar with those of formulated cleaning agents S-1 and S-2. Both the cleaning agent V and the formulated cleaning agents S-1 and S-2 showed similar trends that their pH decrease in the beginning and then increases later on with the increase of their dilution in water. It is considered that the wetting indices of the cleaning agents calculated with experimental values do not not have any influence on their cleaning ability. In ultrasonic cleaning tests under three ultrasonic frequencies of 28, 45, and 100 kHz, their best performances of cleaning solder and flux were obtained at 45 kHz and 28 kHz, respectively, and the cleaning performance of the formulated cleaning agents S-1 and S-2 was better than that of the cleaning agent V. However, in the case of the recommended diluted concentration of 25 wt% cleaning solution, the cleaning performance of the cleaner V for solder and flux was better in the initial stage of cleaning compared to the formulated cleaners. And it may be concluded that the formulated cleaning agents S-1 and S-2 can be applied to cleaning of solder and flux in the industry, based on the experimental results in this study.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.2
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• pp.197-206
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• 2006

This study evaluated the effect of ultrasonic irradiation on improving the flux and cleaning efficiency in membrane process which is widely applied for the treatment of landfill leachate. The experiments on improvement of membrane flux according to the types of membranes(hallowfiber microfiltration, MF and tubular ultrafiltration, UF) were performed with changing frequency($40{\sim}120$ kHz), intensity ($200{\sim}500$ W) and irradiation time of ultrasound as well us operation pressure($0.1{\sim}2.3kg/cm^2$). Membrane was fouled for the first 50 min with primary treated leachate and then the change in flux according to ultrasonic irradiation period was observed for 70 min. Parameters influenced to the recovery ratio corresponding the net flux on pure water and to the enhancement ratio applied after ultrasonic irradiation on the flux were analyzed. In same condition, the flux was improved in proportion to ultrasonic intensity while the improvement of flux was inversely proportional to ultrasonic frequency. The cleaning effect of membrane was delayed and reduced when operation pressure of membrane was high. The recovery ratio and enhancement ratio for $0.1{\mu}m$ MF membrane were 10% and 500%, respectively while those were maximized at $75{\sim}98%\;and\;40{\sim}50%$ for UF membrane for 10,000 and 100,000 MWCO, respectively. In conclusion, it was confirmed that ultrasonic cleaning using mechanical vibration is alternative to water or chemical cleaning for improving membrane flux.