• Membrane Journal
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• v.32 no.4
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• pp.227-234
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• 2022

Wastewater is released from leather, textile, paint, wood, or dye processing industries as well as petroleum refining industries. Wastewater from these industries contains water pollutant such as heavy metals and nitrogen compounds and has high chemical oxygen demand (COD). While there various filtering pollutants from wastewater for safe disposal, membrane-based technology is one of the most efficient methods for its high efficiency and low cost. Among various membranes, zeolite membranes gain spotlight for its cost-effectiveness and have undergone a lot of research. This review is focused on recent progress in zeolite membrane for wastewater treatment in following order: i) wastewater treatment, ii) microfiltration membrane, iii) hollow fiber membrane, and iv) ultrafiltration membrane.

• Advances in environmental research
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• v.9 no.2
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• pp.135-150
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• 2020

Many industries, such as textiles, chemical refineries, leather, plastics and paper, use different dyes in various process steps. At the same time, these industrial sectors are responsible for discharging contaminants that are harmful and toxic to humans and microorganisms by introducing synthetic dyes into wastewater. Of these dyes, methylene blue dye, which is classified as basic dyes, is accepted as a model dye. For this reason, methylene blue dye was selected in the study and its removal from the water was studied. In this study, two efficient biosorbents were developed from chitosan and sunflower waste, an agro-industrial waste and modified using iron nanoparticles. The biosorption efficiency was evaluated for methylene blue (MB) dye removal from aqueous solution under various parameters such as treating agent, solution pH, biosorbent dosage, contact time, initial dye concentration and temperature. We investigated the kinetic properties of dye removal from water for Chitosan-Sunflower (CS), Chitosan-Sunflower-Nanoiron (CSN). When the wavelength of MB dye was spectrophotometrically scanned, the maximum absorbance was determined as 660 nm. For the core shell biosorbents we obtained, we found that the optimum time for removal of MB from wastewater was 60 min. The pH of the best pH was determined as 5 in the studied pH. The most suitable temperature for the experiment was determined as 30℃. SEM-EDAX, TEM, XRD, and FTIR techniques were used to characterize biosorbents produced and modified in the experimental stage and to monitor the change of biosorbent after dye removal. The interactions of the paint with the surface used for removal were explained by these techniques. It was calculated that 80% of CS and 88% of CSN removed MB in optimum conditions. Also, the absorption of MB dye onto the surface was investigated by Langmiur and Frendlinch isotherms and it was determined from the results that the removal was more compatible with Langmiur isotherm.

• Journal of Fashion Business
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• v.5 no.2
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• pp.15-34
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• 2001

Ornaments are accessories for the decoration of the body or dress. They aren't unavoidably required one, but serve to make one's dress perfect as decorative industrial art objects. In Morocco, ornaments were initially used as a sign of social position or the class or an incantatory symbol. In effect, they were originally employed to adjust one's dress, not just for decoration, and they were of use for household economy. Gold, silver and handcraft available for exchange were a means of increasing one's property and an indication of social standing and wealth. In particular, the dress and jewelry of a bride was a measure of her family's wealth, regarded as a symbol of her chastity and value. The ornaments symbolically back up people's faith in supernatural power, and their real value is based on implicit form or way of decoration, not the external shape. Specifically, there is a tendency to use the form of animal as a protector, not one to frighten people. In the artistic tradition of Morocco, fish pattern stands for water and rain, and eagle and bird are considered to be related to fate. Scorpion and lizard are depicted as an inquirer of sun, and snake is a symbol of abundance and sexual instinct, being viewed to have an ability to cure disease. Turtle pattern is a symbol of saint because it protects one from the evil. The ornaments are made of gold, silver, amber, clam, garnet, glass, nielle, enamel, glaze, coral or tree, and symbolic patterns are used, including hand(a symbol of five numerals), turtle, lizard, scorpion, eye, triangle, bird and eggs. They are very big and diverse, being categorized into ornaments for the head or the chest, neckless, fibula, earring, bracelet and ring. For Moroccans, make-up is a sort of instinctive behavior to meet aesthetic and sexual desire. They also wear make-up for practical purpose of protection, intentionally inflict a wound on the skin for ceremonial or religious purpose, paint the skin with pigment, or have the part of the body tattooed for incantatory purpose. All this actions are regarded as make-up. The raw material of cosmetics is aker, a vegetable dye. They get the lips or cheeks turn red and paint eyebrows with yellow saffran powder to have a bad devil lose its strength. Tattooing is mainly done by women and viewed as a sign of their value or social organization they belong to. Sometimes that is used to represent a woman's being old enough to marry or getting married already or the frequency of marriage. Besides, tattoo is believed to prevent or remedy loose bowels or cough, depending on its location or pattern, and they often change tattoo according to the change of beauty art.

• Applied Chemistry for Engineering
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• v.16 no.2
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• pp.250-256
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• 2005

Coating appearance is the most important problem in automotive industry. To increase the coating appearance quality, the corrosion resistance and the coating adhesion on metal substrates must be basically solved. The phosphating film made by the pretreatment of metal substrate is important factor to increase the coating adhesion. During the cathodic electrodeposition, the pH at the cathode surface increases up to about 12. In such a highly alkaline condition, the dissolution of metal substrate and phosphate film occurs. These phenomena result in the decrease of the bonding strength between the phosphating film and the substrate. Generally, the structure of zinc phosphating film is hopeite or phosphophyllite. It has been known that the phosphophyllite film contains better corrosion resistance and paint adhesion for hot water immersion test because of the decrease of dissolving amount of both metal substrate and phosphating film during the cathodic electrodeposition. It is found that the addition of Ni and Mn composition increase P-ratio and then can improve the paint adhesion on metal surface and the corrosion resistance.

• Journal of the Society of Disaster Information
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• v.16 no.4
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• pp.701-711
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• 2020

Purpose: In this study, the risk of flammability of a liquid mixture was experimentally confirmed because the purpose of this study was to confirm the increase or decrease of the flammability risk in a mixture of two substances (combustible+combustible) and to present the risk of the mixture. Method: Flash point test method and result processing were tested based on KS M 2010-2008, a tag sealing test method used as a flash point test method for crude oil and petroleum products. The manufacturer of the equipment used in this experiment was Japan's TANAKA. The flash point was measured with a test equipment that satisfies the test standards of KS M 2010 with equipment produced by the company, and LP gas was used as the ignition source and water as the cooling water. In addition, when measuring the flash point, the temperature of the cooling water was tested using cooling water of about 2℃. Results: First of all, in the case of flammable + combustible mixtures, there was little change in flash point if the flash point difference between the two substances was not large, and if the flash point difference between the two substances was low, the flash point tended to increase as the number of substances with high flash point increased. However, in the case of toluene and methanol, the flash point of the mixture was lower than that of the material with a lower flash point. Also, in the case of a paint thinner, it was not easy to predict the flash point of the material because it was composed of a mixture, but as a result of experimental measurement, it was measured between -24℃ and 7℃. Conclusion: The results of this study are to determine the risk of mixtures through experimental studies on flammable mixtures for the purpose of securing the effectiveness of the details of the criteria for determining dangerous goods in the existing dangerous goods safety management method and securing the reliability and reproducibility of the determination of dangerous goods Criteria have been presented, and reference data on experimental criteria for flammable liquids that are regulated in firefighting sites can be provided. In addition, if this study accumulates know-how on differences in test methods, it is expected that it can be used as a basis for research on risk assessment of dangerous goods and as a basis for research on dangerous goods determination.

• International Journal of Fluid Machinery and Systems
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• v.1 no.1
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• pp.1-9
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• 2008

In the first part of the paper, Computational Fluid Dynamics analysis of the combusting flow within a high-swirl lean premixed gas turbine combustor and over the $1^{st}$ row nozzle guide vanes is presented. In this analysis, the focus of the investigation is the fluid dynamics at the combustor/turbine interface and its impact on the turbine. The predictions show the existence of a highly-rotating vortex core in the combustor, which is in strong interaction with the turbine nozzle guide vanes. This has been observed to be in agreement with the temperature indicated by thermal paint observations. The results suggest that swirling flow vortex core transition phenomena play a very important role in gas turbine combustors with modern lean-premixed dry low emissions technology. As the predictability of vortex core transition phenomena has not yet been investigated sufficiently, a fundamental validation study has been initiated, with the aim of validating the predictive capability of currently-available modelling procedures for turbulent swirling flows near the sub/supercritical vortex core transition. In the second part of the paper, results are presented which analyse such transitional turbulent swirling flows in two different laboratory water test rigs. It has been observed that turbulent swirling flows of interest are dominated by low-frequency transient motion of coherent structures, which cannot be adequately simulated within the framework of steady-state RANS turbulence modelling approaches. It has been found that useful results can be obtained only by modelling strategies which resolve the three-dimensional, transient motion of coherent structures, and do not assume a scalar turbulent viscosity at all scales. These models include RSM based URANS procedures as well as LES and DES approaches.

• Conservation Science in Museum
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• v.17
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• pp.101-116
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• 2016

Ceramic cultural artifacts restored with gypsum-based materials are prone to decay over time due to gypsum's natural absorption and release of atmospheric moisture, often leading to distortion and peeling of painted layers. This study proposes a new restoration material which utilizes extra hard stone, significantly superior in strength to regular gypsum. In order to enhance its physical properties and make it suitable for restoration of ceramics, extra hard stone is mixed with metakaolin. This mixture far surpasses regular gypsum in compressive strength(119MPa vs. 26MPa) while also maintaining a much lower wear rate(0.88% vs. 2.53%). Furthermore, the water absorption rate(2.9%) of the mixed material is over five times lower than that of regular gypsum(17.2%). When examined using a SEM(Scanning Electron Microscope), this mixture also proved superior to extra hard stone in terms of hardened density. The addition of metakaolin increases the mixture's strength and water resistance over that of extra hard stone and also improves its surface density, making it ideal for the restoration of ceramics. It has already been used to repair ceramic objects in the Museum's collection: Clay basin(sinan 18892), Buncheong ware bottle with incised peony design(jubsu 2034), Buncheong ware bowl with chrysanthemum(jubsu 1730). Results thus far have shown the mixture to be easy to inject and layer as well as harden into an even surface, which allows for smooth application of paint for color matching.

• Economic and Environmental Geology
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• v.55 no.3
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• pp.281-293
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• 2022

We examined degradation characteristics of lead based pigments(white lead, Red lead, Litharge) according to atmospheric environmet condition, for example atmospheric gas(CO₂, NO₂) and soluble salt. Painted samples not changed material compositions but were occured the color change(𝚫E 4~31) after exposed UV irradiation. All sample were not affected by CO₂ gas not only color but chemical composition. However, samples were remakably changed color exposed NO₂ gas and it was formed secondary product like as lead nitrate. Such as red lead and white lead samples' color difference were 𝚫E 2 and 𝚫 10 respectively and became dark, along with litharge became bright and color difference was 𝚫E 5 after react with NO₂ gas. It confirm that NO₂ was influential factor than CO₂ in the case of same concentration. Furthermore salt spray test was taken to figure out soluble salt influence in fine dust. The result showed noticeable color change and secondary product was formed on samples' surface. The glue film peeled off or hole, and color changed around the secondary products. After salt spray, XRD pattern showed decrease peak intensity and lower crystalinity. As a result of salt spray test, white lead was formed new product litharge and litharge was formed litharge and minium. According to the results, influential atmospheric factors for conservation of paint pigments were UV, NO₂, soluble salt, and litharge was most weakness throughout lead base pigments.

• Journal of Environmental Health Sciences
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• v.50 no.2
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• pp.146-156
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• 2024

Background: Children who use playground facilities are exposed to potential risks due to the high concentration of heavy metals contained in the finishing materials of facilities in children's playgrounds. Objectives: The purpose of this study was to investigate the concentration of heavy metals in the finishing materials of outdoor children's playgrounds where harmful heavy metals exist in Gwangju and to conduct human risk assessment for children and adults by age to find the risks and limitations. Methods: The bottom and top layers of double-painted paint were peeled off and collected together from the finishing materials of children's play facilities such as slides, swings, and seesaws in 147 children's parks in Gwangju. Heavy metals were analyzed using ICP-OES, etc., and human risk assessment was performed using the concentrations of heavy metals. Results: Based on 1.0E-04, which requires legal regulation, CTE was found to pose a carcinogenic risk for preschool children and no carcinogenic risk for the rest of the age groups. However, RME showed that both men and women of all ages had a carcinogenic risk. For reference, when the carcinogenic risk was based on 1.0E-06, CTE was found to pose a carcinogenic risk from infants to elementary school students, and RME was found to have a carcinogenic risk in all age groups. It was judged that there is a non-carcinogenic risk if the non-carcinogenic risk exceeds 1 based on the hazard index (HI) 1. In CTE, there was no non-carcinogenic risk, and RME for preschooler males (1.49E+00) and females (1.56E+00) were found to have non-carcinogenic risk. Conclusions: This study was meaningful in that it examines the differences in the current management of heavy metals concentration standards and potential carcinogenic and non-carcinogenic risks to the human body and discusses the relationship between heavy metals and human health effects.

• Journal of Navigation and Port Research
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• v.36 no.6
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• pp.459-463
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• 2012

In the present study, experiments have been performed to investigate the effects of the type of adsorbent, pH, and ionic strength on the adsorption of nutrients (nitrate and phosphate in artificial solution) onto the dredged sediment from a coastal fishery. In addition, this study aims to evaluate the possibility of removing the nutrients from the water using the dredged sediment. In the adsorption experiments of the nutrients, the reactions were completed within 10 minutes using ${NO_3}^-$-N($100{\mu}M$, 10mM) and ${PO_4}^{3-}$-P($100{\mu}M$, 10mM). In the steady state, 61% and 77% of the initial amounts were removed respectively for $100{\mu}M$ ${NO_3}^-$-N and $100{\mu}M$ ${PO_4}^{3-}$-P. The thermal treatment of the dredged sediment at $900^{\circ}C$ was not helpful to increase the removal efficiencies of the nutrients. Additives such as CaO and MgO dropped the removal efficiency of ${NO_3}^-$ to 0%, but increased that of ${PO_4}^{3-}$ up to 98%. Adsorption isotherms of ${NO_3}^-$ and ${PO_4}^{3-}$ could be explained by the Freundlich equation ($R^2$>0.99). The adsorption reaction was little influenced by the pH and ionic strength. Based on the results showing short reaction time and considerably high removal efficiencies of the nutrients, it is proposed to apply the dredged sediment from a coastal fishery to removing nutrients such as nitrate and phosphate in the water.