• Textile Coloration and Finishing
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• v.29 no.4
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• pp.202-210
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• 2017

In recent years, the water-based ink have been widely used in various industrial applications due to environmental problems. Dispersibility of the pigment for applications of the water-based ink is the one of the most important technical factors to produce uniform color products. Thus, in this study, the three-roll mill process was used to improve the dispersion of the water-based ink. The results indicated that the three-roll mill reduced the size of pigment particles in the ink more than 50%. In addition, the dispersant showed an important role to maintain the dispersion stability of the pigment in the water-based ink over 120 hours. We also confirmed the optimum contents of the ink stock solution, drying temperature and drying time by the colorimeter and colorfastness tests on produced PET synthetic suedes.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.1
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• pp.87-92
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• 2016

With the population growth and industrialization, the characteristics of discharged waste water and sewage have become more diverse. The removal of phosphorus (P) in the wastewater is essential for the prevention of eutrophication in the river and stream. This study was performed in order to estimate the field application of the Bacillus sp. 3434 BRRJ. Bacillus sp. 3434 BRRJ was cultured in the raw wastewater and synthetic medium at the 5 L reactor. The best optimum conditions for P removal by Bacillus sp. 3434BRRJ in the synthetic medium at the 5 L reactor were as follows: temperature, $30^{\circ}C$; P concentration, 20 mg/L; carbon sources, glucose + acetate (1:1); oxygen concentration, alternatively anaerobic and aerobic conditions. P removal efficiency under the optimum condition was 89.4%. In case of wastewater, P removal efficiency was 95.5% under controlled at $30^{\circ}C$. Through this study we confirmed that P removal by Bacillus sp. 3434BRRJ in case of wastewater was as effective as the synthetic medium. It is considered that Bacillus sp. 3434 BRRJ can be applied to the treatment of wastewater in order to biologically remove P from the wastewater on a large scale.

• Advances in nano research
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• v.5 no.1
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• pp.27-34
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• 2017

One of the methods of removing cyanide from wastewater is surface adsorption. We simulated the removal of cyanide from a synthetic wastewater in the presence of Titanium dioxide nano-particles absorbent uses VISUAL MINTEQ 3.1 software. Our aim was to determine the factors affecting the adsorption of cyanide from synthetic wastewater applying simulation. Synthetic wastewater with a concentration of 100 mg/l of potassium cyanide was used for simulation. The amount of titanium dioxide was 1 g/l under the temperature of $25^{\circ}C$. The simulation was performed using an adsorption model of Freundlich and constant capacitance model. The results of simulation indicated that three factors including pH, nanoparticles of titanium dioxide and the primary concentration of cyanide affect the adsorption level of cyanide. The simulation and experimental results had a good agreement. Also by increasing the pH level of adsorption increases 11 units and then almost did not change. An increase in cyanide concentration, the adsorption level was decreased. In simulation process, rising the concentrations of titanium dioxide nanoparticles to 1 g/l, the rate of adsorption was increased and afterward no any change was observed. In all cases, the coefficient of determination between the experimental data and simulation data was above 0.9.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.2
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• pp.151.2-151.2
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• 2011

IGRINS (Immersion GRating INfrared Spectrometer) will provide the spectra with high-resolution and an instantaneous spectral coverage of H and K band in NIR region. Therefore, it is expected that the wide coverage of wavelength would make a production of an extensive NIR high-resolution spectra of standard stars as a prior program of IGRINS. As a counter part of these NIR spectra, we have planned to obtain the high-resolution spectra of those standard stars in optical band. These optical high-resolution spectra would give us an opportunity to produce the library of high-resolution stellar spectra covering from optical to NIR band, and to confirm the method to determine the stellar parameters and chemical abundances from the NIR high-resolution spectra. Before using the NIR high-resolution spectra, we have tested the method to determine the stellar parameters by comparing between the observed spectra and the synthetic spectra in optical band. In order to make the synthetic spectra, we have used the Kurucz ATLAS9 model grids and the SYNTH code described by Fiorella Castelli (http://wwwuser.oat.ts.astro.it/castelli/). For the cross-check against the parameters that would be derived from the NIR spectra, the stellar parameters such as effective temperature and surface gravity were determined using the optical spectra of the solar-like stars, as preliminary results.

• Journal of Environmental Health Sciences
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• v.19 no.4
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• pp.38-43
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• 1993

The characteristics of food wastewater treatment in an anaerobic packed bed reactor (APBR) with polyurethane as a packing material and sludge bed reactor (ASBR) was studied. The reactor of 9cm-ID, 150cm-height was fed in a continuous mode from bottom of reactor. For the purpose of constant temperature of reactor, water jacket was installed. The used packing materials was polyurethane sponge foam. Methane which was produced by decomposed organics collected at the top of the reactor for using as a fuel. The substrates used were synthetic, mixed and food wastewater. For the acclimatization of microorganisms, mixed wastewater was used. The major analyses were gas production, COD, pH and volatile acids. Based upon the completed works, the results are as follows: When food wastewater was fed the quantity of produced gas was less than that of synthetic wastewater, but food process saw higher methane content than synthetic process. As well as COD removal efficiency of food process reached at about 85%. In aspect of effluent volatile acid, food process showed low concentration of below 500 mg/l, therefore anaerobic reaction stabled. Conclusively food wastewater used can be digested by anaerobic treatment, especially anaerobic packed bed reactor showed 82% of COD removal, 75% of methane content, 10 l of gas production, and anaerobic sludge bed reactor did 79% of COD removal, 75% of methane content, 81 of gas production at 4 kgCOD/m$^3$day, 36$\circ$C.

• Journal of the Korea Institute of Military Science and Technology
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• v.19 no.2
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• pp.185-194
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• 2016

It is essential for generating the synthetic image to test and evaluate a guided missile system in the hardware-in-the-loop simulation. In order to make the evaluation results to be more reliable, the extent of fidelity and rendering performance of the synthetic image cannot be left ignored. There are numerous challenges to simulate the LWIR sensor signature of sea surface depending on the incident angle, especially in the maritime environment. In this paper, we investigate the key factors in determining the apparent temperature of sea surface and propose the approximate formula consisting of optical characteristics of sea surface and sky radiance. We find that the greater the incident angle increases, the larger the reflectivity of sea surface, and the greater the water vapor concentration in atmosphere increases, the larger the amount of sky radiance. On the basis of this information, we generate the virtual maritime environment in LWIR region using the SE-WORKBENCH, physically based rendering software. The margin of error is under seven percentage points.

• 한국연소학회:학술대회논문집
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• 2013.06a
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• pp.109-110
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• 2013

This paper describes gas turbine combustion characteristics of synthetic natural gas which contains a small amount hydrogen content. By conducting ambient pressure high temperature combustion test at gas turbine relevant combustor geometry, the combustion characteristics such as combustion instability, NOx and CO emission, temperatures at turbine inlet, nozzle and dump plane, and flame structure from high speed OH chemiluminescence images were investigated when changing hydrogen content from zero to 5%. From the results, qualitative and quantitative relationships are derived between key aspects of combustion performance, notably NOx/CO emission and combustion instability. Natural gas containing hydrogen up to 5% does not show significant difference in view of all combustion characteristics except combustion instability. Only up to 1% hydrogen addition could not change the pressure fluctuation and phase gas between fluctuations of pressure and heat release. From the results, it can be concluded that synthetic national gas which contains 1% of hydrogen can be guaranteed for the stable and reliable operation of natural gas firing gas turbine.

• Clean Technology
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• v.26 no.4
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• pp.257-262
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• 2020

Two-dimensional (2D) metal organic framework (MOF) nanosheets (NSs) have recently gained considerable interest owing to their structural advantages, such as large surface area and exposed active sites. Two different types of 2D MOF NSs have been reported, including inherently layered MOFs and non-layered ones. Although several studies on inherently layered 2D MOFs have been reported, non-layered 2D MOFs have been rarely studied. This may be because the non-layered MOFs have a strong preference to form three-dimensionality intrinsically. Furthermore, the non-layered MOFs are typically synthesized in the presence of the surfactant or modulator, and thus developing facile and clean synthetic routes is highly pursued. In this study, a facile and clean synthetic methodology to grow non-layered 2D cobalt-based zeolitic imidazolate framework (ZIF-67) NSs is suggested, without using any surfactant and modulator at room temperature. This is achieved by directly converting ultrathin α-Co(OH)2 layered hydroxide salt (LHS) NSs into non-layered 2D ZIF-67 NSs. The comprehensive characterizations were conducted to elucidate the conversion mechanism, structural information, thermal stability, and chemical composition of the non-layered 2D ZIF-67. This facile and clean approach could produce a variety of non-layered 2D MOF NS families to extend potential applications of MOF materials.

• Journal of Environmental Science International
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• v.31 no.12
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• pp.1103-1115
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• 2022

The adsorption characteristics of four pesticides (phosphamidon, fenitrothion, triadimefon, and diniconazole) on natural clinoptilolite (CLI_N) and three synthetic zeolites were investigated. The synthetic zeolites included faujasite (FAU_F) synthesized from coal fly ash; the mixture of FAU and Na-P1 (FAU + Na-P1)_SF synthesized using Jeju scoria and coal fly ash at the ratio of 1.5 by weight; and waste fluid catalytic cracking catalyst (FCC_W). The distribution coefficient, K_D and the Freundlich constant, K_F decreased in the following sequence: FCC_W > FAU_F > (FAU + Na-P1)_SF > CLI_N among the zeolites and diniconazole>fenitrothion> triadimefon> phosphamidon among the pesticides. The pesticide adsorptivity increased with increasing temperature for FAU_F, (FAU+Na-P1)_SF and FCC_W, however, it decreased for CLI_N, regardless of the type of pesticide. The adsorptivity of pesticides was independent of pH for phosphamidon, fenitrothion and triadimefon, whereas it decreased with increasing pH for diniconazole, regardless of zeolite type.

• YAKHAK HOEJI
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• v.42 no.2
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• pp.153-158
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• 1998

Calcium hydrogen phosphate was synthesized by reacting calcium chloride and sodium hydrogen phosphate solution in this study. It is well known that the particle size and yield o f calcium hydrogen phosphate produced is greatly affected by the synthetic conditions such as the reactant concentration, reaction temperature, reacting fine, mole ratio and drying temperature, etc. The purpose of this study is to investigate the optimum synthesis condition from the viewpoint of yield and sedimentation volume of the prepared calcium hydrogen phosphate powder according to a randomized complete block design proposed by G.E.P. Box and K.B. Wilson. It was found that the optimum synthetic conditions of calcium hydrogen phosphate were as follows: It was found that optirnum temperature range of reactant solutions was $28-38^{\circ}C$ and $32-42^{\circ}C$ respectively, on the viewpoint of yield and sedimentation volume. The optimum concentration range of reactant solutions was 5.5-10.0% and 6.9-7.4% respectively, on the viewpoint of yield and sedimentation volume. The optimum mole ratio of $CaCl_2$ to $Na_2HPO_4$ was in the range of 1.2-2.0 and the optimum reacting time range was 8.5-11.0 minutes. The optimum drying temperature range was $39-41^{\circ}C$ from the viewpoint of yield, but it was $39-43^{\circ}C$ on the basis of sedimentation volume. Crystallographic analysis to X-ray diffraction patterns of commercially available ecalcium hydrogen phosphate and calcium hydrogen phosphate samples prepared in this study suggested that all samples tested belonged to monoclinic crystal system characteristic of $CaHP0_4{\cdot}2H_20$ crystals.