• Journal of Electrochemical Science and Technology
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• v.13 no.1
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• pp.148-158
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• 2022

The electrochemical CO₂ reduction (ECR) to produce value-added fuels and chemicals using clean energy sources (like solar and wind) is a promising technology to neutralize the carbon cycle and reproduce the fuels. Presently, the ECR has been the most attractive route to produce carbon-building blocks that have growing global production and high market demand. The electrochemical CO₂ reduction could be extensively implemented if it produces valuable products at those costs which are financially competitive with the present market prices. Herein, the electrochemical conversion of CO₂ obtained from flue gases of a power plant to produce diesel and formic acid using a consistent techno-economic approach is presented. The first scenario analyzed the production of diesel fuel which was formed through Fischer-Tropsch processing of CO (obtained through electroreduction of CO₂) and hydrogen, while in the second scenario, direct electrochemical CO₂ reduction to formic acid was considered. As per the base case assumptions extracted from the previous outstanding research studies, both processes weren't competitive with the existing fuel prices, indicating that high electrochemical (EC) cell capital cost was the main limiting component. The diesel fuel production was predicted as the best route for the cost-effective production of fuels under conceivable optimistic case assumptions, and the formic acid was found to be costly in terms of stored energy contents and has a facile production mechanism at those costs which are financially competitive with its bulk market price. In both processes, the liquid product cost was greatly affected by the parameters affecting the EC cell capital expenses, such as cost concerning the electrode area, faradaic efficiency, and current density.

• Proceedings of the Materials Research Society of Korea Conference
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• 2009.11a
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• pp.6.2-6.2
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• 2009

Nanostructured materials arecurrently receiving much attention because of their unique structural andphysical properties. Research has been stimulated by the envisagedapplications for this new class of materials in electronics, optics, catalysisand magnetic storage since the properties derived from nanometer-scalematerials are not present in either isolated molecules or micrometer-scalesolids. This study presents the experimental results derived fromthe various functional materials processed in nano-scale using pulsed laserablation, since those materials exhibit new physical phenomena caused by thereduction dimensionality. This presentation consists of three mainparts to consider in pulsed laser ablation (PLA) technique; first nanocrystallinefilms, second, nanocolloidal particles in liquid, and third, nanocoating fororganic/inorganic hybridization. Firstly, nanocrystalline films weresynthesized by pulsed laser deposition at various Ar gas pressures withoutsubstrate heating and/or post annealing treatments. From the controlof processng parameters, nanocystalline films of complex oxides and non-oxidematerials have been successfully fabricated. The excellentcapability of pulsed laser ablation for reactive deposition and its ability totransfer the original stoichiometry of the bulk target to the deposited filmsmakes it suitable for the fabrication of various functionalmaterials. Then, pulsed laser ablation in liquid has attracted muchattention as a new technique to prepare nanocolloidal particles. Inthis work, we represent a novel synthetic approach to directly producehighly-dispersed fluorescent colloidal nanoparticles using the PLA from ceramicbulk target in liquid phase without any surfactant. Furthermore, novel methodbased on simultaneous motion tracking of several individual nanoparticles isproposed for the convenient determination of nanoparticle sizedistributions. Finally, we report that the GaAs nanocrystals issynthesized successfully on the surface of PMMA (polymethylmethacrylate)microspheres by modified PLD technique using a particle fluidizationunit. The characteristics of the laser deposited GaAs nanocrytalswere then investigated. It should be noted that this is the first successfultrial to apply the PLD process nanocrystals on spherical polymermatrices. The present process is found to be a promising method fororganic/inorganic hybridization.

• Journal of the Korean Home Economics Association
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• v.19 no.3
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• pp.47-61
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• 1981

The Siuejunsuh is a book of Korean woman's life in the Yi-dynasty which published late in 18 century by unknown author. I have studied the food habits of the Yi-dynasty that wrote in siuejunsuh as following. The staple foods ae Bab (boiled cooked rice) 2, Juk(gruel) 6, Mieum(thin rice gruel) 3, Uee (liquid) 1, D'ockguk 2, Mandu3 Kinds I this book. the side dishes are Guk(soup) 24, Jochi 7, jungol 2, J'im 16, Sinsollo 1, Bockuem 5, Sun 6, Gui 16, Jock 10, jon 12, jorim 7, Namul 14, Sangchae 4, Hyae 17, Joban 2, Nooruemi 1, Sooranpoached egg) 2, Sondae 2, jockpyun 1, Choe 1, Muchim 11, Pyunuk 2, Jockgall 6, Po 9, Ssam 4, Jup 1, Jangaji 27, Kimchi 20, and other 27 Kinds. the desserts are D'ock 41, jabgwa 52, Beverages 17 kinds. the alcohol and frutie liquor are 18 kinds. The seasonings are soybean sauce, Jinjang, red peper bean paste, Zupjang, Dampukjang, Chunggukjang, honey, vinegar, mustard, Yunzup etc. Storage foods are vegetables,fruits and beans etc. There are 62 kinds of table ware and cooking kitchen utensiles, but many of them came to usefulness. 16 kinds of measuring unit are very non-scientific because that is not by weight but by bulk or volume. Thee are many food making terms which are 179 kinds of prepared cooking term, 22 kinds of cutting term and 16 kinds of boiling term. And 20 kinds of expression of taste can be seen in this book. Food serving methods are D'ockiserving method, fruits and dried food serving methode in chanhap (food packed in a nest of boxes) Guksoo serving method, Jock serving method, fruits serving method, Seup serving method etc. Table setting methods ae 9 sets of dinner, 7 sets of dinner, 5 sets of dinner, side table setting, liquor table setting, Sinsollo table setting, food's dab table setting etc.

• Korea-Australia Rheology Journal
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• v.14 no.3
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• pp.129-138
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• 2002

A cationic surfactant, cetyltrimethylammonium $\rho$-toluenesufonate (CTA$\rho$TS), forms long threadlike micelles in aqueous solution. The threadlike micelles make concentrated entanglement networks, so that the solution shows pronounced viscoelastic behavior as concentrated polymer systems do. However, a mechanism for a process responsible for the longest relaxation time of the threadlike micellar system is different from that of semi-dilute to concentrated polymer systems. The threadlike micellar system exhibits unique viscoelasticity described by a Maxwell model. The longest relaxation time of the threadlike micellar system is not a function of the concentration of CTA$\rho$TS, but changes with that of $\rho$-toluenesufonate ($\rho$$TS^{-}$) ions in the bulk aqueous phase supplied by adding sodium $\rho$-toluenesulfonate (NapTS). The rates of molecular motions in the threadlike micelles are not influenced by the concentration of $\rho$$TS^{-}$ anions, therefore, molecular motions in the threadlike micelles (micro-dynamics) are independent of the longest relaxation mechanism (macro-dynamics). A nonionic surfactant, oleyldimethylamineoxide (ODAO), forms long threadlike micelles in aqueous solution without any additives. The aqueous threadlike micellar system of ODAO also shows Maxwell type viscoelastic behavior. However, the relaxation mechanism for the longest relaxation process in the system should be different from that in the threadlike micellar systems of CTA$\rho$TS, since the system of ODAO does not contain additive anions. Because increase in the average degree of protonation of head groups of ODAO molecules in micelles due to adding hydrogen bromide causes the relaxation time remarkably longer, changes in micro-structure and micro-dynamics in the threadlike micelle are closely related to macro-dynamics in contrast with the threadlike micellar system of CTA$\rho$TS.

• Restorative Dentistry and Endodontics
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• v.37 no.4
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• pp.207-214
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• 2012

Objectives: This study evaluated the influence of chlorhexidine (CHX) on the microtensile bonds strength (${\mu}TBS$) of resin core with two adhesive systems to dentin in endodontic cavities. Materials and Methods: Flat dentinal surfaces in 40 molar endodontic cavities were treated with self-etch adhesive system, Contax (DMG) and total-etch adhesive system, Adper Single Bond 2 (3M ESPE) after the following surface treatments: (1) Priming only (Contax), (2) CHX for 15 sec + rinsing + priming (Contax), (3) Etching with priming (Adper Single Bond 2), (4) Etching + CHX for 15 sec + rinsing + priming (Adper Single Bond 2). Resin composite build-ups were made with LuxaCore (DMG) using a bulk method and polymerized for 40 sec. For each condition, half of specimens were submitted to ${\mu}TBS$ after 24 hr storage and half of them were submitted to thermocycling of 10,000 cycles between $5^{\circ}C$ and $55^{\circ}C$ before testing. The data were analyzed using ANOVA and independent t-test at a significance level of 95%. Results: CHX pre-treatment did not affect the bond strength of specimens tested at the immediate testing period, regardless of dentin surface treatments. However, after 10,000 thermocycling, all groups showed reduced bond strength. The amount of reduction was greater in groups without CHX treatments than groups with CHX treatment. These characteristics were the same in both self-etch adhesive system and total-etch adhesive system. Conclusions: 2% CHX application for 15 sec proved to alleviate the decrease of bond strength of dentin bonding systems. No significant difference was shown in ${\mu}TBS$ between total-etching system and self-etching system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.3
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• pp.444-453
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• 2007

This paper deals with a powerful countermeasure for power quality problems caused by the operation of electrical arc furnace in bulk power systems. The rapid active load fluctuations of electrical arc furnace could produce several problems such as voltage flicker and active power oscillations. The typical methods using only the reactive power compensation have their own limitation in solving the power quality problems caused by active load variations. The coordination of both active and reactive power compensation is required to solve the power quality problems. This paper focuses on the impacts and the dynamic phenomena caused by the active load fluctuation. This paper proposes the optimal algorithm for the active power compensation based on the function of 1(n ratio and the concepts for the active power compensation. The results from a case study show that the proposed methods can be a practical tool for the power quality problems in power systems.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.183-183
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• 2011

Multiferroic materials have been widely studied in recent years, because of their abundant physics and potential applications in the sensors, data storage, and spintronics. $BiFeO_3$ is one of the well-known single-phase multiferroic materials with $ABO_3$ structure and G-type antiferromagnetic behavior below the Neel temperature $T_N$ ~ 643 K, but the ferroelectric behavior below the Curie temperature $T_c$~1,103 K. In this study, the $BiFe_{1-x}Ni_xO_3$ (x=0 and 0.05) bulk ceramics were prepared by solid-state reaction and rapid sintering with high-purity $Bi_2O_32$, $Fe_3O_4$ and NiO powders. The powders of stoichiometric proportions were mixed, as in the previous investigations, and calcined at 450$^{\circ}C$ for $BiFe_{1-x}Ni_xO_3$ for 24 h. The obtained powders were grinded, and pressed into 5-mm-thick disks of 1/2-inch diameter. The disks were directly put into the oven, which has been heated up to 800$^{\circ}C$ and sintered in air for 20 min. The sintered disks were taken out from the oven and cooled to room temperature within several min. The phase of samples was checked at room temperature by powder x-ray diffraction using a Rigaku Miniflex diffractometer with Cu K${\alpha}$ radiation. The Raman measurements were carried out by employing a hand-made Raman spectrometer with 514.5-nm-excitation $Ar^+$ laser source under air ambient condition on a focused area of 1-${\mu}m$ diameter. The field-dependent magnetization measurements were performed with a superconducting quantum-interference-device magnetometer.

• Explosives and Blasting
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• v.32 no.1
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• pp.23-30
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• 2014

The overall management for explosives in domestic and regulation for blasting is managed by the control Act of guns, sword, explosives etc. On the details for handling and method, delivery, storage, use and management for explosives and work safety for the accident prevention is recommended to the related business site through Standard safety work guideline of blasting which set by safety & health 27 Act handling. In this study, It reviews the standard safety work guideline of blasting notified by Ministry of employment & labor. We propose the new products introduced into domestic explosives market, definition of explosives word when the newest blasting technology is revised, emulsion explosives, bulk explosives and electronic detonators which increased in the latest. Indeed, We propose a typical handling method of non-electric detonator and electronic in order to make the renewed Standard safety work guideline of Blasting on work guideline.

• Korean Journal of Food Science and Technology
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• v.16 no.1
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• pp.37-40
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• 1984

A simple and low cost autogenous-type extruder with a capacity of about 400kg/hr for rice bran-oil stabilization was developed. Specific energy consumption of the extruder was 0.060-0.070 KWH/kg of rice bran during extrusion. Rice bran was easily extruded to form flakes or pellets with an increase of bulk density. And also the desired extrusion temperature of $95^{\circ}C{\;}to{\;}150^{\circ}C$ could be easily obtained without any water addition when the rice bran was properly parametered with feed rate. The moisture content of bran was reduced and peroxidase was significantly inactivated after extrusion. The rice bran stabilized by the extrusion process was excellent in storage stability without considerable increase in free fatty acids.

• Journal of the East Asian Society of Dietary Life
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• v.15 no.4
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• pp.437-443
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• 2005

Quality characteristic of Kipfel cookies with 0, 20, 40 and $60\%$ of freeze dried chitosan-chungkukjang(CC), which was fermented for 24 hours at $40^{\circ}C$ with steamed soybean added with $0.25\%$ of chitosan(MW 2,025 kDa) powder and inoculated $2\%$ of Bacillus lichenifomis, were investigated Bulk density was higher in the CC cookie, but there were no difference among the CC cookies. While hardness was decreased, brittleness and springiness were increased in the higher ratio of CC, but no significant difference was observed in cohesiveness and gumminess. According to increasing the CC ratio, L$\ast$ values and hue angle were decreased from 62.69 and 96.71 to 44.41 and 69.30, respectively. While a$\ast$ values were increased from -1.94 to 4.95, and no changes were observed in b$\ast$ values. Glucosamine content was $27.34 mg\%$ in the control cookie, $40{\~}93.75 mg\%$ in the CC cookies. Antioxidant activity of the CC cookies were higher than the control. The activity of the control cookie was decreased during storage, while it was maintained in CC cookies. There were no differences in the sour, sweet and savory taste. Off-flavor did not detected in the $0{\~}40\%$ CC cookies, but the chungkukjang odor was slightly detected in the $60\%$ CC cookie. The $20{\~}40\%$ CC cookies did not affect on native odor of Kipfel cookie. Color acceptability also did not affect by addition of CC $20{\~}40\%$ but it was lower in $60\%$ CC cookie. Overall acceptability was the best in the $20\%$ CC cookie.