• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.04a
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• pp.150-151
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• 2022

Blasting is a method that uses explosives to crush the ground. This method is a highly efficient ground cleaning method that can secure high efficiency in a short time. However, explosions can damage local properties and produce high noise and vibration. Therefore, it is important to be careful because there are disadvantages such as the occurrence of many complaints from the surrounding area. In this paper measured and analyzed the noise and vibration generated during blasting at the blasting site in Korea. The noise and vibration generated during blasting were measured by ES03303.2b and ES03402.2a at a distance of 6 m, 12 m from the blasting point. As a result of the measurement, there was little difference between small and medium scale except for precision vibration blasting at a distance of 6m, but noise difference according to blasting scale was evident at a distance of 12m. As a result of the measurement, the maximum noise level was reduced to 5.5 dB(A) and the vibration level was reduced to 7.7 dB(V). In the future, the reliability of the test results can be further improved through additional tests, and it is judged that noise and vibration prediction models based on blasting methods, amount of charge, measuring distance, etc. can be developed.

• Journal of the Korea Organic Resources Recycling Association
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• v.20 no.4
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• pp.97-105
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• 2012

This study examined for possibility of the food wastewater incineration treatment method as one of overland treatment method by incineration through liquefied spray of food wastewater when incinerating domestic wastes under operation and for the relationship, etc of air discharge material discharged in incineration, and the results of study are as follow: The food wastewater as one of overland treatment method was analysed 94-96% of moisture contents. Temperature of incinerator outduct during mixed incineration of food wastewater with MSW was average $897^{\circ}C$ and incineration of only MSW was $925^{\circ}C$. Temperature of the mixed incineration of food wastewater was dropped about $28^{\circ}C$ by incineration of only MSW. Concentration of nitrogen oxides(NOx) among air discharge gases was studied by 50ppm, 46ppm when inputting $200{\ell}/hr$, $300{\ell}/hr$ into the incinerator as the quantity of food wastewater. In the mixed incineration of food wastewater, generation speed of scales in the inside of a tubular exhaust gas boiler became rapid and the scale generation quantity became large but the exhaust gas boiler normally operated since scales were removed in cleaning of the tube with a compressive air cleaning facility and there was no opening clogging phenomena in a filter cloth of the filtering dust collector. The overland treatment method, not ocean dumping of food wastewater can be proposed as a technology since mixed incineration of food wastewater with MSW in the existing domestic waste incineration plant is possible, and operation costs of the incineration facility were reduced since use of chemicals such as ammonia and urinary hydrogen ion excretion, etc used in incineration facilities for removing nitrogen oxides(NOx).

• Applied Chemistry for Engineering
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• v.16 no.5
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• pp.664-671
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• 2005

In this study, the effect of sosurfactant on microemulsion phase behavior was investigated in ternary systems containing alkyl ethoxylates nonionic surfactant, water and d-limonene. The addition of a cosurfactant produced a microemulsion phase over a wide range of temperature and promoted formation of a microemulsion phase at lower temperatures. In particular, small amounts of n-propanol, as a cosurfactant, were found to be the most effective in extending a microemulsion phase region over a wide range of temperature. Temperature sensitivity of a nonionic surfactant system was effectively relieved by addition of the anionic surfactant sodium dodecyl sulfate. And the formation of one phase microemulsion was not affected by pH, hardness concentration and addition of an antioxidation agent. The cleaner candidates were determined from microemulsion phase behavior study, and their cleaning efficiency was tested using a dipping method. All the cleaner candidates selected during this study showed excellent removal efficiency for abietic acid over a temperature range from 30 to $40^{\circ}C$ presumably due to a decrease in interfacial tension.

• The Journal of Engineering Geology
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• v.23 no.1
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• pp.29-36
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• 2013

The application of appropriate rehabilitation methods can improve the efficiency of clogged wells and extend their life. In this paper, we study the feasibility of well cleaning using high-voltage pulsed discharge, in which electrical energy is used to produce impulsive pressure in water, in contrast to conventional methods that employ chemical or pneumatic energy sources. This technique utilizes the compressive shock wave generated by the expansive force of hot, dense plasma that is produced during a pulsed discharge in the gap between electrodes immersed in water. Compared with conventional techniques, this method is simple, and easy to handle and control. Using a capacitive pulsed power system with an electrical energy of 200 J, an impulsive pressure of 10.7 MPa is achieved at the position 6 cm away from the discharge gap. The amplitude of the impulsive pressure was easily controlled by adjusting the charging voltage of the capacitor and was almost linearly proportional to peak discharge current. The technique achieved good results in cleaning feasibility tests with mock-up specimens similar to clogged well screens.

• Journal of Conservation Science
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• v.30 no.2
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• pp.123-136
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• 2014

Considering that decision in conservation treatment for damaged objects should consider not only various options of methodology of intervention but also possible consequences of different types of intervention, it is a difficult task to decide and propose clear and safest solution of preserving an object. In addition, it should be constantly challenged by conservators even if it is proved technique or methodology in a past treatment. Therefore, there is no absolute solution which can be applied to all practice but each decision can be different case by case. It is not possible to estimate the way how the present condition of material and environmental aspects would affect to the condition of an object in future. However if conservators keep trying to set out various ways of analysing pro and against effect of past treatments, it would be able to provide useful logics of proving efficiency and appropriateness of a certain treatment. Understanding that the advantage of laser technique is to adopt a way of cleaning an object without making a direct contact, which is different from other techniques, this paper aims at securing stability of laser techniques, although it remains a limitation in the compatibility to all other materials. This study has examined reacting process on the painted pigments against laser beam by using CLSM in order for it to display both the problems from such reacting process and the efficiency of it as a cleaning methodology. It has intended to estimate the result of laser techniques and propose the range of applicability.

• Journal of Conservation Science
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• v.30 no.1
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• pp.27-32
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• 2014

The sample book was printed in 1935. Since the books in the early twentieth century were printed using acidic paper, the color of the paper would change to brown over time due to iron corrosion. In addition to corroding iron cores, the acidity of the paper (pH 3.2) also made the paper brown and fragile, as was true in the case of the sample book. To clean the paper of the sample book and to make it strong, we replaced the iron core and performed wet cleaning on the paper to remove contaminants. Then we pressed the sample book dry, and subsequently linening every page with Minoshi($4g/m^2$). Generally, book conservator rebinding the book using wires or threads: however we have devised a new method to rebind the book using colored iron cores. To color the iron core brown, they were dipped in an aqueous coloring solution ($H_2O$, $C_2H_5OH$, $CuSO_4{\cdot}5H_2O$, $FeCl_3{\cdot}6H_2O$); subsequently, a 20% paraloid B-72 was applied to protect the colored iron cores from corrosion.

• Journal of Conservation Science
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• v.29 no.2
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• pp.127-138
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• 2013

Plastic, widely used as a material for contemporary art, get damaged as directly exposed to temperature, humidity, ultra violet, etc. And it is very quickly damaged in early time, once damaged, it can't recover into original state. But like this characteristics, there is a few advanced research in Korea. So this study deal with a rising value of plastic artifacts in other country, United Kingdom and France, current conservation state, identification and cleaning method. Also 5 types of cleaners(distilled water, ethanol, acetone, eraser) and adhesives(cyanoacrylate, epoxy, acrylic, chloroprene rubber) were evaluated by produced plastics(PVC, PE, PP, PS, PU). As a result of experiment, ethanol and acetone that were previous evaluated in other research performed in other country are the best cleaner. Result of degradation after adhesive, cyanoacrylate and epoxy resin showed better performance and stability. As a basic research, this study is expected that can be used in future researches.

• Journal of the Korean Recycled Construction Resources Institute
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• v.11 no.2
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• pp.153-160
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• 2023

In this study, nano-sized C-S-H crystals were synthesized using the liquid phase reaction method and their properties were investigated. The synthesized C-S-H crystals were added to the cement composite in suspension form to determine their effect on the hydration properties of the cement. The amount of chemical admixture was varied to obtain nano-sized C-S-H crystals with optimal agglomerated morphology, and SEM photographs were analyzed. A cleaning process was added to remove harmful substances other than the synthesiz ed C-S-H crystals. It was found that the concentration of harmful substances was reduced in the case of C-S-H crystals subjected to the cleaning process. The synthesized C-S-H suspensions were prepared with and without the cleaning process, and cement composites were prepared with the cement weight content as the main variable. The effect of C-S-H crystals on the initial hydration properties of the cement was confirmed by microhydration heat analysis. In addition, mortar specimens were prepared to measure the compressive strength over time. The test results showed that the nano-sized C-S-H crystals act as nucleation sites in the cement paste to promote the early hydration of the cement and increase the early compressive strength.

• Analytical Science and Technology
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• v.18 no.2
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• pp.112-119
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• 2005

This study reports on the efficiency of cleaning enameled magnet wire using a sulfuric acid $H_2SO_4$ and removal of dissolved organic material using hydrogen peroxide $H_2O_2$ and nitric acid $HNO_3$ at $80^{\circ}C$. The method involves the addition of pure $H_2SO_4$ and $H_2O_2$ or $HNO_3$. Layers of enameled organic material were dissolved by 90% $H_2SO_4$ and the solution was maintained as 35% $H_2O_2$ or 60% $HNO_3$. $H_2O_2$ content in aqueous $H_2O_2$ was maintained as 8.8 : 1.0. An initial concentration of $H_2SO_4$ in dissolution conditions was accomplished within 15 min, with a stripping time of about 2 h. The concentrations of $H_2O_2$ and $HNO_3$ in the processing bath were relatively low, but sufficient enough to produce an effective amount of power in the bath for the removal of the enamel material. The cleaning effect of enameled organic material involves the dehydration by $H_2SO_4$ and the oxidation by $H_2O_2$ or $HNO_3$.

• The Korean Fashion and Textile Research Journal
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• v.15 no.1
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• pp.138-146
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• 2013

Chemical compositions and biological functions of brown colorants extracted from pine bark(Pinus densiflora) have been studied. Dyeing test using multifiber fabrics with extracted colorants were preliminary carried out. Dyeing conditions and fastness tests of selected fabrics have been also studied. The brown colorants were produced 1.5% concentrations by solvent extraction from milled pine bark using methanol. The colorants were extracted with 80% methanol as best choice by a criteria of solid quantity and dyeability on fabrics. The chemical compositions were identified as mixtures of taxifolin epicatechin and procyanidin by LC/MS analysis. The brown colorants could be dyed not only natural fibers such as cotton, silk and wool but also synthetic fiber as nylon and semi-synthetic fiber as viscose rayon. Maximum K/S values was shown at 400 nm according to different fiber with color appearance of redish brown. Optimum pH and temperature of dyeing conditions was 4 and above $80^{\circ}C$, respectively. The brown colorants had a strong antioxidant activity compared to Butylated hydroxyanisole as standard and weak antimicrobial activity against E. coli. compared to kanamycin. Washing, rubbing, perspiration, dry cleaning and light fastness for cotton, nylon and silk dyed with the brown colorants were carried out by KS K method. Most of color fastness such as washing, rubbing, perspiration, and dry cleaning were represented as 4-5 grade. However, light fastness was reported as 2-3 grade. From this studies, brown colorants produced pine bark have a high potentials for natural dyeing on fabrics with antioxidant activity.