• Journal of the Korean Society for Precision Engineering
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• v.30 no.4
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• pp.390-396
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• 2013

Due to the development of technology, there is a considerable increase in the number of skyscrapers in the world. Accordingly, there are rapid growing requests about maintenances such as cleaning, painting, and inspection. However, it is extremely dangerous working the walls of buildings, and crashes from buildings have accounted for large proportion of constructional accidents. Especially, as the number of buildings with irregular shapes increases, the accident rate during the maintenance work increases each year, and most of the accidents lead to death. An alternative solution must be developed with the commercialization of automatic systems. In this research, a fundamental research has been conducted for drafting and commercializing an automation tool that is carried in the built-in guide system, which can perform cleaning.

• Environmental Engineering Research
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• v.23 no.4
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• pp.474-484
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• 2018

The cleaning efficiency of reverse osmosis (RO) membranes inevitably fouled by organic foulants depends upon both chemical (type of cleaning agent, concentration of cleaning solution) and physical (cleaning time, flowrate, temperature) parameters. In attempting to determine the optimal procedures for chemical cleaning organic-fouled RO membranes, the design of experiments concept was employed to evaluate key factors and to predict the flux recovery rate (FRR) after chemical cleaning. From experimental results and based on the predicted FRR of cleaning obtained using the Central Composite Design of Minitab 17, a modified regression model equation was established to explain the chemical cleaning efficiency; the resultant regression coefficient ($R^2$) and adjusted $R^2$ were 83.95% and 76.82%, respectively. Then, using the optimized conditions of chemical cleaning derived from the response optimizer tool (cleaning with 0.68 wt% disodium ethylenediaminetetraacetic acid for 20 min at $20^{\circ}C$ with a flowrate of 409 mL/min), a flux recovery of 86.6% was expected. Overall, the results obtained by these experiments confirmed that the equation was adequate for predicting the chemical cleaning efficiency with regards to organic membrane fouling.

• Journal of the Korean institute of surface engineering
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• v.45 no.4
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• pp.143-150
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• 2012

Laser cleaning have been found to be a useful cleaning tool to remove contaminants without inducing damage to the substrate and making secondary pollutant. In this study, the effect of Nd:YAG laser cleaning system, emitting at 1064 nm and 532 nm, on acrylic resin applied onto copper coupons and pieces of bronze was investigated. The samples after laser cleaning tests were examined using microscopy, FT-IR, SEM-EDS. As a result, the acrylic resin could be removed from most of the samples at low laser energy density. Laser wavelength 532 nm was more effective than 1064 nm because of using lower laser energy density, which could reduce heat damage to substrates. Although the acrylic resin was easily removed, it revealed melted surfaces and removed bronze patina which must remain. The problems should be solved by future studies using different laser system or laser wavelengths.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.6
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• pp.815-820
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• 2013

With the development of technology, there has been a considerable increase in the number of skyscrapers in the world. Accordingly, there are increasing requirements with regard to maintenance, such as cleaning, painting, and inspection. However, it is extremely dangerous to work on the walls of buildings, and falls from buildings have accounted for a large proportion of construction accidents. In particular, as the number of buildings with irregular shapes increases, the accident rate during maintenance work has increased each year, with most accidents leading to deaths. An alternative solution must be developed with the commercialization of automatic systems. In this study, fundamental research has been conducted for drafting and commercializing an automation tool with a built-in guide system that can perform cleaning.

• Journal of Korean Society of Water and Wastewater
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• v.25 no.3
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• pp.285-291
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• 2011

Membrane fouling is an unavoidable phenomenon and major obstacle in the economic and efficient operation under sea water reverse osmosis (SWRO). When fouling occurs on the membrane surface, the permeate quantity and quality decrease, the trans-membrane pressure (TMP) and operation costs increase, and the membrane may be damaged. Therefore, chemical cleaning process is important to prevent permeate flow from decreasing in RO membrane filtration process. This study focused on proper chemical cleaning condition for Shuaibah RO plant in Saudi Arabia. Several chemical agents were used for chemical cleaning at different contact time and concentrations of chemicals. Also autopsy analysis was performed using LOI, FT-IR, FEEM, SEM and EDX for assessment of fouling. Specially, FEEM analysis method was thought as analyzing and evaluating tool available for selection of the first applied chemical cleaning dose to predict potential organic fouling. Also, cleaning time should be considered by the condition of RO membrane process since the cleaning time depends on the membrane fouling rate. If the fouling exceeds chemical cleaning guideline, to perfectly remove the fouling, certainly, the chemical cleaning is increased with membrane fouling rate influenced by raw water properties, pre-treatment condition and the point of the chemical cleaning operation time. Also choice of cleaning chemicals applied firstly is important.

• The Journal of Korea Robotics Society
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• v.4 no.1
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• pp.74-80
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• 2009

This paper presents a remote monitoring and simulation system for a building cleaning mobile robot. It provides a tool of convenient 3D graphical map construction including network camera image viewer and status information of the robot. The 3D map is reconstructed from existing 2D building CAD data with DXF format using OpenGL graphic API. Through this system, it is possible to monitor and control the cleaning mobile robot from remote place. A practical experiment is performed to show the reliability and convenience of the monitoring system. The proposed system is expected to give efficient way of control and monitoring to building cleaning mobile robot.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1769-1770
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• 2007

To prevent an insulator failure, an automatic cleaning robot was developed for suspension insulator strings. The robot autonomously moves along the insulator string using the clamps installed on its two moving frames, and adopts a dry cleaning method using rotating brushes and a circular motion guide. In addition, a mechanized brush bristles and a voltage-balancing contactor are devised to increase cleaning efficiency and to prevent arc generation under live-line conditions, respectively. Moreover, a manual tool for its installation and removal is presented. We confirmed its effectiveness through experiments.

• Journal of Power System Engineering
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• v.18 no.1
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• pp.63-68
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• 2014

The numerical analysis of fluid flow in the tube cleaning system is examined. The working flow used in this study is seawater, and the temperature change is not considered as the temperature change of seawater in the tube cleaning system is negligible. Also, the analysis is performed under the assumption of steady state. The screens of complicated morphologies are simplified for the analysis, and only one fourth of the tube cleaning system is modeled as the system has a symmetrical shape. The velocity inlet boundary condition is employed for the seawater inlet, whereas the outflow boundary condition is employed for two seawater outlets. In applying the outflow boundary condition for the system with more than two outlets, the flow rate can be arbitrarily assigned. In the analysis, the finite-volume method based numerical analysis tool, the pressure based solver, the standard k-$\varepsilon$ model are utilized, and the under relaxation factor is modified appropriately. From the analysis, the distribution of velocity vectors, pressure and path lines are obtained, and the physical characteristics of fluid flow in the tube cleaning system is well-examined.

• Journal of Conservation Science
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• v.19
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• pp.19-30
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• 2006

Alteration of physical and chemical characteristics and the effect of removal of mineral substances in waterlogged archaeological woods by different cleaning processes were examined using oak wood(Quercus spp.) that was excavated from wetland near Gwangju, Korea. Cleaning methods employed in the present work were (1) tools, (2) deaeration, (3) EDTA and (4) ultrasonic cleaning, which are being currently applied in the field of preservation treatment. Cleaning process were performed independently or continuously. Composition of mineral substances in the waterlogged archaeological wood was almost same as the that of soil in which waterlogged archaeological woods were buried. In case of independent cleaning, tools cleaning efficiently removed the mineral substances on surface. Surface color become brighter after cleaning with EDTA. In contrast, deaeration and ultrasonic cleaning did not show any significant removal of mineral substances. In continuous cleaning process, tool cleaning as the first step treatment showed the same effect as shown in independent cleaning. Although deaeration as the second step cleaning did not remove the mineral substances, it could be assumed to contribute the infiltration of dimensional agents by homogenization of wood. EDTA treatment (the third step cleaning) removed the iron(Fe) and increased the whiteness of wood color. The ultrasonic treatment (the fourth step cleaning) removed the sodium(Na) remained after EDTA treatment and the fine mineral substances.

• Journal of Conservation Science
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• v.10 no.1 s.13
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• pp.10-20
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• 2001

Since the feasibility for the application of laser to the conservation of artworks had been demonstrated by John F. Asmus at 1972 it was known from many experiments that laser cleaning technology Provided superior characteristics over conventional cleaning methods based on mechanical and chemical actions. Then, the research and development of the cleaning technology was carried out strongly in Europe and many successful cleaning applications such as stone, painting, stained glass, paper, leather, and metal have been reported. However this is not familiar as a cleaning tool in the restoration of artworks in oriental countries including Korea. Therefore, this article aims to introduce a laser cleaning technology and its characteristics for the applications to art restoration. The contents in this article include general principles and characteristics of laser, the introduction of laser cleaning technology, and real laser applications for artwork restoration.