• Journal of Conservation Science
• /
• v.26 no.4
• /
• pp.417-427
• /
• 2010

This study is to examine the manufacturing technique based on scientific investigation and analysis on Steel-Plated Jewel Beetle's Adornment gilt-bronze openwork remains excavated from No. 100 site at Hwango-dong Gyeongju. As a result of the investigation on the manufacturing revealed that riveting was adopted to connect gilt-bronze openwork plates and steel plates, followed by mercury amalgam plating method and carving of the patterns by means of the dotted line engraving technique. There were some traces on the surface of Jewel Beetle wings that show the use of pins for fixing, which seems to be the result of recycling or processing. The sectional analysis shows the high possibilities that varnishing with lacquer was adopted for wing adhesion, and it was confirmed that varnishing with lacquer was used on the strap pendant plate to prevent corrosion.

• Journal of the Korean Ceramic Society
• /
• v.38 no.12
• /
• pp.1162-1166
• /
• 2001

NiZn-ferrite was synthesized from waste catalysts, which were produced from styrene monomer process and buried underground as an industrial wastes, and its magnetic properties were investigated. Nickel oxide and zinc oxide powders were mixed with finely ground waste catalysts, and spinel type ferrite was obtained by calcination at 900$\^{C}$ and sintering at 1230$\^{C}$ for 5 hours. The intial permeability was measured and reflection loss was calculated from S-parameters for the composition of Ni$\_$x/Zn$\_$1-x/Fe$_2$O$_4$(x=0.36, 0.50, 0.66). NiZn-ferrite synthesized from waste iron oxide catalyst showed a feasibility for the use as electromagnetic wave absorber in X-band.

• Journal of Korea Port Economic Association
• /
• v.26 no.2
• /
• pp.99-118
• /
• 2010

This objective of this study is to thoroughly analyze the policies of international organizations and major advanced countries relevant to the realization of Green port To construct Green ports, there first must be competition to build such ports in sustainable, fixed quantities. Second, there is a great need for cooperation and support networks made binding by mutual agreements on ship recycling. Third, there is a need for scientific research on responses to changes in environmental regulations and on environmental issues. Today, the majority of the world's ports use gasoline or electric energy, and improving capacities for self-sufficiency through development of new and renewable energy is judged to be a pressing task. The conditions for an eco-friendly port is that it must be an important center for economic and industrial activity, and valuable as a site where people live and work, with residences and work places existing in close proximity.

• Food Science and Biotechnology
• /
• v.16 no.1
• /
• pp.127-132
• /
• 2007

[ ${\alpha},\;{\alpha}$ ]-Trehalose was efficiently modified by a transgalactosylation reaction of Escherichia coli ${\beta}-galactosidase$ using lactose as a donor to yield two galactosyl trehalose trisaccharides. The reaction products of trehalose by the enzyme were observed by thin layer chromatography (TLC) and high performance anion exchange chromatography (HPAEC) and were purified by BioGel P2 gel permeation chromatography and recycling preparative HPLC. Liquid chromatography-mass spectrometry (LC-MS) and ^{13}C$ nuclear magnetic resonance (NMR) analyses revealed that the structures of the main products were $6^2-{\beta}-D-galactosyl$ trehalose (1) and $4^2-{\beta}-D-galactosyl$ trehalose (2). A reaction of 30%(w/v) trehalose and 15%(w/v) lactose at pH 7.5 and $45^{\circ}C$ resulted in a total yield of approximately 27-30% based on the amount of trehalose used. The galactosyl trehalose products were not hydrolyzed by trehalose. In addition the mixture of transfer products (9:1 ratio of 1 to 2) showed higher thermal stability than glucose, lactose, and maltose, but less than trehalose, against heat treatment over $100^{\circ}C$ at pH 4 and 7. It also exhibited better thermal stability than sucrose at pH 4 alone.

• Korean Chemical Engineering Research
• /
• v.44 no.6
• /
• pp.579-587
• /
• 2006

Recently, each country has been trying to promote Eco-Industrial Park (EIP) development for industrial sustainability. Technological modeling is required to realize EIP practically even though the project contains the political concerns for many companies, government, and self-governing bodies. The four main technologies of the EIP developments include energy exchange, material flow analysis, water pinch, and life cycle assessment. Material flow analysis (MFA) methodology can be utilized in EIP modeling in view of the fact that the analysis of material flows and the optimized modeling are major purposes for the technological modeling of EIP. Through MFA methodology in POHANG EIP project, how to apply MFA modeling to EIP modeling and how to utilize software for MFA modeling are shown in this research.

• Journal of Environmental Health Sciences
• /
• v.35 no.3
• /
• pp.226-234
• /
• 2009

The main objective of this study was to evaluate the effects on shape and size, compressive strength, water absorption and heavy metals leaching with various weight mixing ratios in waste ash brick products using waste recycling MSWI(Municipal Solid Waste Incinerator) bottom ash, steel slag and waste building material. The manufacturing processes for the waste ash brick consist of screening, mixing, conveyor transmission, compaction.forming, and curing steps of raw materials. The weight mixing ratios of steel slag around bottom ash were adjusted within the ranges of 10% to 30%. The reported results show that the width and thickness of the manufactured waste ash brick could be satisfied with $90{\pm}2mm\;and\;57{\pm}2mm$, respectively which are K.S. standards of products qualities. And in case of length, only 20-Ba50Ss30, 20-Ba60Wb20 and 20-Ba50Wb30 for the mixing ratios could be satisfied with $190{\pm}2mm$ that is K.S. standards of products quality. The compressive strength and water absorption for 20-Ba50Ss30 and 20-Ba70Wb10 were over $8N/mm^2$ and below 15% respectively that are K.S. standards of manufactured waste ash brick. The results of tests for the heavy metals leaching in the all manufactured waste ash bricks are also passed to the wastes management regulations. The cost analysis of 20-Ba50Ss30 is evaluated. The manufacturing cost is evaluated 34.3 won/brick with 8 hours and 20tons of raw material per day. Incinerators with problems in bottom ash disposal can therefore derive significant benefits from the application of waste ash brick production.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.8 no.2
• /
• pp.161-166
• /
• 2020

In accordance with the amendment of the Industrial Safety and Health Act of 2007, Korea completely prohibited the import, distribution and manufacture of asbestos like Europe and Japan. Accordingly, the current problem of asbestos is the safe maintenance and disposal of asbestos construction material, the disposal of asbestos, and the final disposal of asbestos building materials. If the asbestos building material is made harmless, it may be classified as general waste or as recyclable waste. Therefore, this study evaluated the physical and chemical characterization of detoxified asbestos powder and the applicability of secondary products. In this study, it was found that applying the appropriate temperature and pressure for catalysis during asbestos desalination through low temperature chemical treatment was the most important factor.

• Journal of Energy Engineering
• /
• v.26 no.1
• /
• pp.1-8
• /
• 2017

This study was carried out to physicochemical properties and free CaO contents of coal ash in domestic circulating fludized bed combustion power plant using ethylene glycol method. Results of physicochemical properties, there are many differences in CaO contents for the region position in CFBC plant. The reason, It is considered to be reflected that regulation of exhaust concentration for oxides of sulfur and other operation characteristics of region position in CFBC plant. Free CaO contents are 1.96 ~ 10.78% of fly ash and 0.07~4.24 % of bottom ash, fly ash is higher than in the bottom ash. besides CaO contents of raw materials, particle distribution have a lot of influence Free CaO contents.

• Smart Structures and Systems
• /
• v.24 no.4
• /
• pp.541-552
• /
• 2019

Construction development and greenhouse gas emissions have globally required a strategic management to take some steps to stain and maintain the environment. Nowadays, recycled aggregates, in particular ceramic waste, have been widely used in concrete structures due to the economic and environmentally friendly solution, requiring the knowledge of recycled concrete. Also, one of the materials used as a substitute for concrete cement is wollastonite mineral to decrease carbon dioxide (CO2) from the cement production process by reducing the concrete consumption in concrete. The purpose of this study is to investigate the effect of wollastonite on the mechanical properties and durability of conventional composite concrete, containing recycled aggregates such as compressive strength, tensile strength (Brazilian test), and durability to acidic environment. On the other hand, in order to determine the strength and durability of the concrete, 5 mixing designs including different wollastonite values and recovered aggregates including constant values have been compared to the water - cement ratio (w/c) constant in all designs. The experimental results have shown that design 5 (containing 40% wollastonite) shows only 6.1% decrease in compressive strength and 4.9% decrease in tensile strength compared to the control plane. Consequently, the use of wollastonite powder to the manufacturing of conventional structural concrete containing recycled ceramic aggregates, in addition to improving some of the properties of concrete are environmentally friendly solutions, providing natural recycling of materials.

• Journal of Convergence for Information Technology
• /
• v.11 no.10
• /
• pp.171-181
• /
• 2021

This study tried to derive improvement measures by identifying the perceptions of industrial college instructors and learners in the technology convergence sector, where various technologies are combined, as distance education at colleges are prolonged due to COVID-19 and difficulties for instructors and learners continue. To this end, an online survey was conducted on automobile professors and students at the end of the second semester of 2020. As a result of the survey analysis, it was found that professors and students had similar perceptions about the advantages of online classes, such as freedom of time and space, repeatable learning, and recycling. In terms of difficulties, it was found that students felt a decrease in learning immersion due to a lack of sense of presence, and both professors and students felt the difficulty of interaction relatively large. This study is meaningful in that it prepares suggestions and basic data on college policy support for online education at industrial colleges during and after COVID-19.