• Journal of the Korean Recycled Construction Resources Institute
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• v.2 no.2
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• pp.93-100
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• 2006

Building materials are trending toward environmental materials nowadays and the market share of those is growing. So those researches and developments for environmental property are proceeding now. The main properties of environmental products are far infrared emission, negative ion emission, electro magnetic wave shielding, and anti fungus, these products are used with shape of mortar, and spray on the finish material. But There are not much researches for the concrete, main material in construction field, with those functional properties. So in this research we evaluated slump, compressive strength and air content as basic properties for concrete using functional materials of sericite, wood pattern sand stone, carbon black and nanometric silver solution and functional properties like far infrared emission, negative ion emission, electro magnetic wave shielding, and anti fungus. The results were as follows. The most useful material in the functional materials was carbon black. Sericite and nanometric silver solution had a little effect on functional property, so it was difficult to apply to concrete, and wood pattern sand stone had a high functional property but low compressive strength, can be applied to a factory product. Anti fungus of the concrete using nanometric silver solution was not clear but if those specimens were aged in $CO_2$ gas for a long time it might apparent.

• International Journal of Concrete Structures and Materials
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• v.18 no.3E
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• pp.165-171
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• 2006

Environment-friendly materials are increasingly used as building construction materials nowadays, and the market share of those is growing. Accordingly, the research and developments in terms of environmental value are progressing steadily now. The main characteristics of environmental products are far-infrared radiation, negative-ion emission, electromagnetic wave shielding, and antimicrobial property. These products are often used in mortar and as spray on the finishing material. Nevertheless, there are hardly any research on the functional properties of concrete, the main material in construction field. Thus, we evaluated such basic properties of concrete as slump, compressive strength and air content while using such functional materials as sericite, wood-pattern sandstone, carbon black and nano-metric silver solution to focus on their functional properties like far-infrared radiation, negative ion emission, electro magnetic wave shielding, and antimicrobial activity in this research. The results indicated that the most useful material in the functional materials was carbon black. Sericite and nano-metric silver solution had a little effect on the functional property. Moreover, although wood-pattern sandstone had very high functional property, it exhibited too low compressive strength to be applied, to concrete as a factory product. Antimicrobial property of nano-metric silver solution in the concrete was not clear demonstrated, but if these specimens were to be aged in $CO_2$ gas for a long time, it might be apparent.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.12 s.189
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• pp.88-94
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• 2006

In this study, the dynamic impact analysis for the passenger air-bag(PAB) module has been carried out by using FEM to predict the dynamic characteristics of vehicle ride safety against head impact. The impact performance of vehicle air-bag is directly related to the design parameters of passenger air-bag module assembly, such as the tie bar bracket's width and thickness, respectively, However, the product's design of PAB module parameters are estimated through experimental trial and error according to the designer's experience, generally. Therefore, the dynamic analysis of head impact test of the passenger air-bag module assembly of automobile is needed to construct the analytical methodology At first, the FE models, which are consist of instrument panel, PAB Module, and head part, are combined to the whole module system. Then, impact analysis is carried out by the explicit solution procedure with assembled FE model. And the dynamic characteristics of the head impact are observed to prove the effectiveness of the proposed method by comparing with the experimental results. The better optimized impact performance characteristics is proposed by changing the tie bracket's width md thickness of module. The proposed approach of impact analysis will provides an efficient vehicle to improve the design quality and reduce the design period and cost. The results reported herein will provide a better understanding of the vehicle dynamic characteristics against head impact.

• Journal of Food Hygiene and Safety
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• v.31 no.3
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• pp.201-209
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• 2016

Many atmospheric pollutants including chemical agents, house dust, and microorganisms cause building-related illnesses through respiration in humans. This study was conducted to analyze the profiles of microbial pollutants in air purifiers used in home, office and playschool. Dominant eleven species of microorganisms were isolated and identified in environmental air and air purifiers. Among them, Staphylococcus sp., Micrococcus sp. and Bacillus sp. are the most dominant species. By phylogenetic analysis of the 16S rRNA gene, the dominant bacteria were identified as Staphylococcus epidermidis, Micrococcus luteus and Bacillus epidermidis, respectively. It has been known that these bacterial species are closely related with food spoilage and human infectious disease. Thus, these results indicate that microbial pathogens related with human illnesses through respiration will be contaminated in air purifiers and also need to develop a method to control those of pathogens for human health.

• Carbon letters
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• v.8 no.2
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• pp.101-107
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• 2007

Activated carbons were prepared by impregnation of crushed clean date pits in concentrated solutions of phosphoric acid or zinc chloride followed by carbonization in absence of air at $600^{\circ}C$. Steam-activated carbon was prepared by gasifying $600^{\circ}C$-carbonization product at $950^{\circ}C$ to a burn-off = 50%. KOH- activated carbon was prepared by impregnating date pitscarbonization product obtained at $450^{\circ}C$ in concentrated KOH solution followed by carbonization at $840^{\circ}C$. Textural properties of these carbons were determined from nitrogen adsorption at $-196^{\circ}C$ and the chemistry of the carbon surface was investigated by determination and of the surface carbon-oxygen (C-O) groups using bases of variable strength and dilute HCl. The adsorption of endosulphan at $27^{\circ}C$ on all the carbons prepared was undertaken. Adsorption of this pesticide at 32 and $37^{\circ}C$ was also undertaken for steam-activated and KOH-activated carbons. Phosphoric acid-activated carbons and steamactivated carbons are mainly microporous and have high surface concentration of C-O groups of acidic nature. Steamactivated and KOH-activated carbons exhibited surface areas > 1000 $m^2/g$ and contain micro and non-micrpores. The adsorption of endosulphan was related to the surface area of non-micropores and was retarded by the high concentration of surface C-O groups. The thermodynamic properties indicated the feasibility of the adsorption process and the possible regeneration of the carbon for further use.

• Journal of Fashion Business
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• v.19 no.2
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• pp.23-35
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• 2015

In this study, the effect of shrink-resist treatment agent on the wool finishing, specifically anti-felting of wool product was studied. We aimed at providing preliminary data leading to the diversification of high-value added fashionable wool product. Two type of wool fabrics, dense and sheer, were employed. The fabric specimens were treated with solutions of shrink-resist treatment agent with wet pick-up rate 110%, 130%, and 150%, respectively, by using a padding mangle. The solution treated fabric specimens were then dried at room temperature first, at $90^{\circ}C$ for 15 minutes in a drying oven, and finally cured at $130^{\circ}C$ for 3 minutes. Cured wool fabric specimens were then subjected to a felting process. The physical and mechanical properties, including shrinkage rate along warp/filling direction, thickness at specified measurement pressure, drape stiffness, and air-permeability, were analyzed. After felting process, the shrinkage rates of wool fabric specimens, treated with shrink-resist treatment agent, were lower than those of control wool fabric specimens. The stiffness values of wool fabric specimens measured by using Flexometer were increased.

• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.2
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• pp.139-147
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• 1991

The preservative effect of cellophane film packing on the quality of semi-salted and dried mackerel was studied. The product(P) of semi-salted and dried mackerel was prepared from raw mackerel by filleting, cleaning, soaking in 15%9v/w) salt solution for 30min, draining, packing with cellophane film (PT# 300, thickness:$20{\mu}{\textrm}{m}$) and drying for 4 hrs at $40^{\circ}C$ in hot air dryer. The product (C) was also prepared without cellophane film packing after draining. The product (C) and (P) were stored at $5.0{\pm}0.5^{\circ}C$. After processing and during storage, moisture content of product (P) was higher than that of product (C), but contents of VBN(volatile basic nitrogen), amino nitrogen and TMA of product (P) on dry basis were lower than those of product (C). Viable cell count, TBA value, peroxide value and decreasing rate of polyenoic acid of product (P) were also lower than those of product (C). In sensory evaluation, the shelf life of product (C) was about 9 days and that of product (P) was about 14 days. From the results of chemical and sensory evaluation, it was concluded that cellophane film packing was a good condition for preserving the quality of semi-salted and dried mackerel.

• Advanced Composite Materials
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• v.18 no.2
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• pp.187-195
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• 2009

Much attention has been paid to the processing of inorganic whisker, especially calcium carbonate whisker, which can be used as reinforcement materials of polymer composite due to its low price. Unfortunately, the present synthesis technique of calcium carbonate whisker starts from calcinations of limestone, which involves high energy consumption and furthermore is a highly environment polluting reaction. In this report, needle-like aragonite was synthesized with a reversible solution reaction from limestone without calcination. Optical microscopy, scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques were used to characterize the morphology and crystal structure of intermediates as well as that of the product, aragonite. GCC (grinding calcium carbonate) powder was dissolved in an aqueous solution of magnesium sulfate with reflux and air flush. EDTA titration was used to evaluate reaction rate of the dissolution. A kinetics equation of the dissolution reaction was constructed, which displayed second-order kinetics with respect to the concentration of magnesium sulfate. A rate constant of $0.0015\;l^{-3}{\cdot}mol^{-1}{\cdot}h^{-1}$ was obtained. The dissolution reaction gave fiber-like magnesium hydroxide sulfate and gypsum crystal. Then needle-like aragonite with a length of $9.13\;{\pm}\;1.02\;{\mu}m$ and an aspect ratio of $5.64\;{\pm}\;1.37$ was synthesized from the dissolution product with $CO_2$ bubbling at $70^{\circ}C$.

• Applied Chemistry for Engineering
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• v.22 no.3
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• pp.296-300
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• 2011

In this work, various wood biomasses were used to determine the combustion characteristics for the fuel of cogeneration plant. Combustion characteristics of four types, i.e., (i) forest products, (ii) recycled wood, (iii) empty fruit bunch, and (iv) palm kernel shell, were examined via thermal gravimetric analyzer (TGA) in air atmosphere and coal was used as a comparison group. From the TGA results, the combustion of the wood biomass was occurred in the range of 280 to $420^{\circ}C$, which was lower than that of coal. Forest product showed the lowest activation energy (0.4 kJ/mol) compared to that of other wood biomasses (about 6 to 14 kJ/mol) and coal (64 kJ/mol). In addition, the reaction rate constant of the wood biomass was lower than that of coal. These results indicate the higher combustion initiation rate of wood biomass due to the high content of volatile matter, which had a low boiling point.

• ETRI Journal
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• v.44 no.5
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• pp.715-732
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• 2022

Despite the successful launch of Advanced Television Systems Committee (ATSC) 3.0 broadcasting worldwide, broadcasters are facing obstacles in constructing void-less large-scale single-frequency networks (SFNs). The bottleneck is the absence of decent on-channel repeater (OCR) solutions necessary for SFNs. In the real world, OCRs suffer from the maleficent feedback interference (FI) problem, which overwhelms the desired input signal. Moreover, the undesired multipaths between studio-linked transmitters and the OCR deteriorate the forward signals' quality as well. These problems crucially restrict the feasibility of conventional OCR systems, arousing the strong need for cost-worthy advanced OCR solutions. This paper presents an ATSC 3.0-specific solution of advanced OCR that solves the FI problem and refines the input signal. To this end, the FI canceler and channel equalizer functionalities are carefully implemented into the OCR system. The presented OCR system is designed to be fully compliant with the ATSC 3.0 specifications and performs a fast and efficient signal processing by exploiting the specific frame structure. The real product of ATSC 3.0 OCR is fabricated as well, and its feasibility is verified via field and laboratory experiments. The implemented solution is installed at a commercial on-air site and shown to provide substantial coverage gain in practice.