• Bulletin of the Korean Chemical Society
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• v.29 no.5
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• pp.1007-1012
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• 2008

Spray pyrolysis has been found as an excellent method for the preparation of mesoporous barium sulfate at higher temperature. Ethylene glycol, a reducing agent, and solvents had good inhibition effect for the preparation of $BaSO_4$ nano particles. The $BaSO_4$ solution was sprayed at 500 & 800 ${^{\circ}C}$ using different solvents such as methanol, ethanol, propanol and n-butyl alcohol. $N_2$ adsorption-desorption isotherm revealed that $BaSO_4$ is micropore free, possessing narrow mesopores size distribution and high BET surface areas of 72.52 $m^2\;g^{-1}$ at 800 ${^{\circ}C}$ using propanol as an additive. Scanning electron microscopy (SEM) indicates that the morphology of $BaSO_4$ nano material shows uniform shell like particles. Transmission electron microscopy (TEM) proved that the resulting BaSO4 nano particles were uniform in size and the average particle size was 4-8 nm. The surface functionality and ethylene glycol peaks were assessed by Fourier transform infrared resonance (FTIR) spectroscopy. Low intensity ethylene glycol specific absorption peak was observed in propanol which proved that propanol had good inhibition effect on the structural morphology of nano particles.

• The Research Journal of the Costume Culture
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• v.19 no.4
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• pp.851-862
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• 2011

The purposes of this study were to identify the material manipulation techniques for paper garments and their characteristics. Reference books or articles were reviewed and catalogues from paper garments exhibition or show, brochures from Paper Museums, and internet sites of paper fashion designers were selected for analysis. Paper has much similarity with natural cellulose textiles in appearances and contents but has much distinct differences in their physical characteristics such as strength, durability, washability, and resilience, and could be treated as one category of textiles. Paper garments were developed with practicality and functionality for the poor and Buddist monks at first but progressed into more aesthetics later for the rich. Paper garments could be divided into 4 categories of garments made of paper, paper thread fabric or knit, modified paper with wanter, and beaten bark of mulburry bush. Paper can be manipulated by coloring & cutting, bonding, or quilting and bonding or quilting can reenforce the strength of paper but cannot increase flexibility. Paper manipulated by weaving or knitting has very similar physical properties as cotton or linen and ideal for summer textiles. Paper can be manipulated with water to make a paper paste and bodice can be moulded with paper paste or Joomchied. Also we can express beautiful patterns on the surface of paper by washouting. Konnyaku paste or lacquer can be used to make paper garments to be waterproof.

• Journal of the Korean Society of Safety
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• v.29 no.1
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• pp.70-79
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• 2014

This paper is on a new design of a household fire extinguisher with an increased initial responsiveness in case of fire. A public survey was taken prior to the new design and 133 faithfully answered surveys among the respondents were used as the research material. The survey was divided into the contents on the recognition of the fire extinguisher, the general requirements and improvement, and it was carried out to be classified on the basis of the results. Design summaries based on the results of surveys conducted are: First, the distance of fire distinguishing material to reach was made to be controlled for more responsiveness in terms of functionality. Second, the head of the fire extinguisher is in red and the spray button is in luminous paint to glow in the dark in terms of visibility. Third, it is made smaller and added a separate handle for bigger sized fire extinguishers in terms of mobility. Fourth, it is made in an aerosol type and has a friendly character on it in terms of approachability. Finally, colors of vivid tones, harmonious pastel tones or light greyish tones were used in terms of aesthetics. With the above study results applied to existing fire extinguisher design, it may contribute to reducing any fire damage.

• Coupled systems mechanics
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• v.6 no.1
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• pp.29-40
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• 2017

This work employed density functional theory to investigate the structural and ferroelectric properties of the Ruddlesden-Popper (RP) phase of lead titanate, $Pb_2TiO_4$, as well as its phase transitions with epitaxial strain. A wealth of novel structural instabilities, which are absent in the host $PbTiO_3$ material, were identified in the RP phase through phonon soft-mode analysis. Our calculations showed that the ground state of $Pb_2TiO_4$ is antiferroelectric, distinct from the dominant ferroelectric phase in the corresponding host material. In addition, applied epitaxial strain was found to play a key role in the interactions among the instabilities. The induction of a sequence of antiferroelectric and antiferrodistortive (AFD) phase transitions by epitaxial strain was demonstrated, in which the ferroic instability and AFD distortion were cooperative rather than competitive, as is the case in the host $PbTiO_3$. The RP phase in conjunction with strain engineering thus represents a new approach to creating ferroic orders and modifying the interplay among structural instabilities in the same constituent materials, enabling us to tailor the functionality of perovskite oxides for novel device applications.

• Steel and Composite Structures
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• v.34 no.2
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• pp.227-239
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• 2020

The aim of this study is to obtain the nonlinear and post-buckling responses of relatively thick functionally graded plates with oblique elliptical cutouts using a new semi-analytical approach. To model the oblique elliptical hole in a FGM plate, six plate-elements are used and the connection between these elements is provided by the well-known Penalty method. Therefore, the semi-analytical technique used in this paper is known as the plate assembly technique. In order to take into account for functionality of the material in a perforated plate, the volume fraction of the material constituents follows a simple power law distribution. Since the FGM perforated plates are relatively thick in this research, the structural model is assumed to be the first order shear deformation theory and Von-Karman's assumptions are used to incorporate geometric nonlinearity. The equilibrium equations for FGM plates containing elliptical holes are obtained by the principle of minimum of total potential energy. The obtained nonlinear equilibrium equations are solved numerically using the quadratic extrapolation technique. Various sets of boundary conditions for FGM plates and different cutout sizes and orientations are assumed here and their effects on nonlinear response of plates under compressive loads are examined.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.34 no.4
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• pp.262-268
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• 2021

For the past several decades, various next-generation patterning methods have been developed to obtain well-designed nano-to-micro structures, such as imprint lithography, nanotransfer printing (nTP), directed self-assembly (DSA), E-beam lithography, and so on. Especially, nTP process has much attention due to its low processing cost, short processing time, and good compatibility with other patterning techniques in achieving the formation of high-resolution functional patterns. To transfer functional patterns onto desirable substrates, the use of soft materials is required for precise replication of master mold. Here, we introduce a simple and practical nTP method to create highly ordered structures using various polymeric replica materials. We found that polymethyl methacrylate (PMMA), polystyrene (PS), and polyvinylpyridine (PVP) are possible candidates for replica materials for reliable duplication of Si master mold based on systematic analysis of pattern visualization. Furthermore, we successfully obtained well-defined metal and oxide nanostructures with functionality on target substrates by using replica patterns, through deposition and transfer process. We expect that the several candidates of replica materials can be exploited for effective nanofabrication of complex electronic devices.

• Korean Journal of Materials Research
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• v.31 no.5
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• pp.264-271
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• 2021

Porous carbons have been widely used as electrode material for supercapacitors. However, commercial porous carbons, such as activated carbons, have low electrochemical performance. Nitrogen-doping is one of the most promising strategies to improve electrochemical performance of porous carbons. In this study, nitrogen self-doped porous carbon (NPC) is prepared from melamine foam by carbonization to improve the supercapacitive performance. The prepared NPC is characterized in terms of the chemical structures and elements, morphology, pore structures, and electrochemical performance. The results of the N₂ physisorption measurement, X-ray diffraction, and Raman analyses reveal that the prepared NPC has bimodal pore structures and pseudo-graphite structures with nitrogen functionality. The NPC-based electrode exhibits a gravimetric capacitance of 153 F g^-1 at 1 A g^-1, a rate capability of 73.2 % at 10 A g^-1, and an outstanding cycling ability of 97.85 % after 10,000 cycles at 10 A g^-1. Thus, the NPC prepared in this study can be applied as electrode material for high-performance supercapacitors.

• International Journal of Computer Science & Network Security
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• v.23 no.9
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• pp.37-46
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• 2023

The main aim of the article is to solve the problem of automating price monitoring using marketing forecasting methods and Excel functionality under martial law. The study used the method of algorithms, trend analysis, correlation and regression analysis, ANOVA, extrapolation, index method, etc. The importance of monitoring consumer price developments in market pricing at the macro and micro levels is proved. The introduction of a Dummy variable to account for the influence of martial law in market pricing is proposed, both in linear multiple regression modelling and in forecasting the components of the Consumer Price Index. Experimentally, the high reliability of forecasting based on a five-factor linear regression model with a Dummy variable was proved in comparison with a linear trend equation and a four-factor linear regression model. Pessimistic, realistic and optimistic scenarios were developed for forecasting the Consumer Price Index for the situation of the end of the Russian-Ukrainian war until the end of 2023 and separately until the end of 2024.

• Food Science of Animal Resources
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• v.30 no.4
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• pp.661-668
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• 2010

This study was carried out to optimize microencapsulation conditions for Inonotus obliquus extract powder with mediumchain triacylglycerol (MCT) using response surface methodology (RSM), and to determine the possibility of adding encapsulated I. obliquus extract to milk toward improving the functionality of milk. and to investigate the effects of added encapsulated I. obliquus extract on the physicochemical and sensory properties of the product. The microencapsulation efficiency of I. obliquus extract powder was investigated with respect to three variables (ratios of core material to coating material, amounts of water added, and spray pressure) in RSM. The optimal conditions for microencapsulation of I. obliquus extract powder were obtained from the ratio of core material to coating material (2.92:10) and the amount of water added (0.5 mL); the spray pressure had an insignificant effect on the microencapsulation (p<0.05). Adding encapsulated I. obliquus extract into milk did not significantly affect either color (L, a and b values) or thiobarbituric acid (TBA) values. Sensory test revealed that there were significant improvements in brownish, herb flavor, and bitterness scores for encapsulated I. obliquus extract-added milk as compared with those for uncapsulated I. obliquus extract-added milk. Based on the data obtained from the present study, it is concluded that microcapsules of I. obliquus extract powder could be applicable to milk without remarkably adverse effects on physicochemical and sensory properties

• Textile Coloration and Finishing
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• v.25 no.4
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• pp.314-326
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• 2013

The purpose of this research is to analyze the effects of Dansam and Sappan wood extract to perform combination dyeing on silk fabrics, with respect to color changes, fastness (washing, dry cleaning, perspiration, rubbing and light fastness), and functionality (antibacterial activity and deodorization). Combination dyeing was performed by first combining Dansam with Sappan wood, then Sappan wood with Dansam, in these orders. Given the changes in the combination ratio, pre-mordant treatment was performed. Looking at the surface colors of each dye, Dansam generally produces YR color series, while Sappan wood produces YR, R, and RP color series. The effects of changing the order in which combination dying was performed on the surface colors were as follows. First, combination dyeing (A) was performed by using Dansam before Sappan wood, to produce YR and R color series. Then combination dyeing (B) was performed by using Sappan wood before Dansam, to produce YR, R, and RP color series. By visual inspections, more similar color changes of the combination dyeing were noticed with the post-dyeing material rather than the pre-dyeing material. Therefore, it was presumably confirmed that surface color changes of combination dyeing were greatly influenced by the post-dyeing color. Individual dyeing tests for fastness showed that Dansam was comparatively superior to Sappan wood, which demonstrated lower fastness to washing, dry cleaning, perspiration, and light, relatively. The fastness of combination dyed samples was shown middle, but similar fastness to the post-dye material, The fastness of (B) method was higher than (A) method in the washing and light fastness. This confirms that color fastness from combination dyeing was considerably influenced by the post-dye material. It was found that all dyed samples had a very high bacterial reduction rate of 99.9% and high deodorization rate of 95%.