• Korea-Australia Rheology Journal
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• v.16 no.1
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• pp.35-45
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• 2004

Rates of chemical absorption of $CO_2$ in water-in-oil (w/o) emulsion were measured in a flat-stirred vessel at $25^{\circ}C$. The w/o emulsion was composed of aqueous monoethanolamine (MEA) droplets as a dispersed phase and non-Newtonian viscoelastic benzene solutions of polybutene (PB) and polyisobutylene (PIB) as a continuous phase. The liquid-side-mass transfer coefficient ($k_L$) was obtained from the dimensionless empirical equation containing Deborah number expressed as the properties of pseudoplasticity of the non-Newtonian liquid. $k_L$ was used to estimate the enhancement factor due to chemical reaction between $CO_2$ and MEA in the aqueous phase. PIB with elastic property of non-Newtonian liquid made the rate of chemical absorption of $CO_2$ accelerate compared with Newtonian liquid.

• Korean Chemical Engineering Research
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• v.49 no.3
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• pp.314-319
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• 2011

In this study, the flow behavior of Newtonian and non-Newtonian coating liquids inside slot die has been scrutinized for the purpose of optimal internal die design in slot coating system from three-dimensional computations by CFD Fluent solver. A hybrid slot die could be optimally designed by changing the chamber or manifold structure to guarantee the uniform velocity distribution of coating liquids at die exit. Especially, for the non-Newtonian coating liquids, the length of coat-hanger for the uniform coating has been properly chosen, according to the degree of their shearthinning properties.

• Korea-Australia Rheology Journal
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• v.17 no.4
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• pp.199-205
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• 2005

Carbon dioxide was absorbed into aqueous polyethylene oxide (PEO) solution containing AMP in a flat-stirred vessel to investigate the effect of non-Newtonian rheological behavior of PEO on the rate of chemical absorption of $CO_2$, where the reaction between $CO_2$ and AMP was assumed to be a first-order reaction with respect to the molar concentration of $CO_2$ and AMP respectively. The liquid-side mass transfer coefficient, which was obtained from the dimensionless empirical equation containing the properties of viscoelasticity of the non-Newtonian liquid, was used to estimate the enhancement factor due to chemical reaction. PEO with elastic property of non-Newtonian liquid made the rate of chemical absorption of $CO_2$ accelerate compared with Newtonian liquid based on the same viscosity of the solution.

• Bulletin of the Korean Chemical Society
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• v.33 no.7
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• pp.2207-2212
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• 2012

Dimethylaluminum isopropoxide (DMAI, $(CH_3)_2AlO^iPr$) as a single precursor, which contains one aluminum and one oxygen atom, has been adopted to deposit non-stoichiometric aluminum oxide ($AlO_x$) films by low pressure metal organic chemical vapor deposition without an additional oxygen source. The atomic concentration of Al and O in the deposited $AlO_x$ film was measured to be Al:O = ~1:1.1 and any serious interfacial oxide layer between the film and Si substrate was not observed. Gaseous by-products monitored by quadruple mass spectrometry show that ${\beta}$-hydrogen elimination mechanism is mainly contributed to the $AlO_x$ CVD process of DMAI precursor. The current-voltage characteristics of the $AlO_x$ film in Au/$AlO_x$/Ir metalinsulator-metal (MIM) capacitor structure show high ON/OFF ratio larger than ${\sim}10^6$ with SET and RESET voltages of 2.7 and 0.8 V, respectively. Impedance spectra indicate that the switching and memory phenomena are based on the bulk-based origins, presumably the formation and rupture of filaments.

• Journal of the Semiconductor & Display Technology
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• v.6 no.3
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• pp.1-6
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• 2007

The integrated thermal-chemical-mechanical (TCM) material removal model presented in the companion paper is dynamically simulated in this work. The model is applied to a Cu CMP process for the simulation and the results of the three individual ingredients composing the model are presented separately first. These results are then incorporated to calculate the total material removal rate (MRR) of the Cu CMP. It is shown that the non-linear trend of MRR with respect to the applied mechanical power (i.e., non-Prestonian behavior), which is not well explained with the models established in principle on conventional contact mechanics, may be due to the chemical reaction(s) varying non-linearly with the temperature in the wafer.

• Journal of the Korean Society of Clothing and Textiles
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• v.27 no.9_10
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• pp.1144-1152
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• 2003

Kenaf has been cultivated in Jeju Island. After being harvested at 105 DAP(day after planting) and separated from kenaf stalks , decorticated kenaf basts were treated with different concentration/temperature/time combinations in order to do chemical rotting. The following fiber properties were compared; rotting effects, colors, crystallinity, molecular structures, dyeabilities, and non-cellulose contents such as pectins, lignins, & hemicellulose. The best results of chemical rotting were obtained from the specimens treated with low concentration/ low temperature/short time. Their colors were bright yellow. The lumens of specimens diminished with the affect of NaOH. The structures of chemically rotted kenaf fibers were cellulose 1. The degree of crystallinity of chemically retted kenaf fibers were very high. Non-cellulose content, especially hemicellulose, was low in the specimens treated with the high NaOH concentration. Dyeabilities of kenaf fibers were higher among the specimens without the non-cellulose content than those with the non-cellulose content.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.33 no.3
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• pp.265-272
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• 2023

Objectives: Since the material safety data sheets(MSDS) submission and non-disclosure review system was introduced in January 2021, the implementation status of MSDS for chemical manufacturing and importing workplaces being supervised for the first time. Methods: A supervisory team consisting of two labor inspectors and one from the Korea Occupational Safety and Health Agency directly visited the selected workplaces to check compliance with the MSDS system as a whole. Results: As a result of supervising 214 chemical substance manufacturing/importing workplaces, a total of 241 violations of the law were found in 121 workplaces, or 57% of them. In response, the Ministry of Employment and Labor took legal action on 8 cases in 6 locations, imposed a fines totaling of 249.69 million won on 120 chemical handling workplaces, and took action to correct the violations immediately. Conclusions: Major violations were in the order of non-request for warning signs, non-submission of MSDS, non-execution of MSDS training, and non-posting of MSDS. This shows the reality that employers who handle chemical substances are sufficiently communicating chemical information to workers. In the future, the government will actively implement preparation and submission support and system guidance for the implementation of the MSDS system, while making efforts to ensure that the MSDS system works well in the field through thorough on-site supervision in the future.

• Bulletin of the Korean Chemical Society
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• v.34 no.8
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• pp.2441-2445
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• 2013

Chitosan non-woven fabrics were acetylated to improve their antimicrobial properties. The active chlorine content, antimicrobial properties, storage stability, and surface properties of acetylated chitosan non-woven fabrics were investigated. The active chlorine content of the fabrics increased upon reduction of the degree of the acetylation or increase in sodium hypochlorite concentration. Acetylated chitosan non-woven fabrics showed powerful antimicrobial activity by efficiently killing Escherichia coli and forming a growth inhibition zone for Staphylococcus aureus. Furthermore, scanning electron microscopy observations demonstrated that the acetylated chitosan non-woven fabrics were not damaged in sodium hypochlorite solution.

• Korean Chemical Engineering Research
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• v.48 no.1
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• pp.121-127
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• 2010

This study is to optimize the enzyme(lipase) activity for biodiesel production. The ion-exchanged non-woven fabrics(EtA, DEA-EtA non-woven fabric) containing ethanolamine, diethylamine groups are used by radiation induced grafted polymerization onto a non-woven fabric for more effective immobilization of lipase. Since the porous hollow fiber membranes are showed the low throughputibehe non-woven fabric membranes are used for biodiesel production. The physical charateristics of enzyme immobilized and the enzyme activity to EtA and DEA-EtA non-woven fabrics are studied. The EtA non-woven fabrics are quite similar to DEA-EtA non-woven fabric for the amount of enzyme immobilized(EtA non-woven fabric:15.69 mg/g, DEA-EtA non-woven fabric:14.45 mg/g) but DEA-EtA non-woven fabrics have shown the lower permeabiliquite the organic solvent than the EtA non-woven fabrics(EtA non-woven fabric:$3.50mol/h{\cdot}kg$, DEA-EtA non-woven fabric:$0.38mol/h{\cdot}kg$). Optimum characteristics of ehe non-woven fabric membranes and the limilaractivity are also investigated for the effective biodiesel production.

• Bulletin of the Korean Chemical Society
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• v.21 no.7
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• pp.712-714
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• 2000

Non-Lorentyian resonance is predicted to occur in two-photon photoabsorption processes due to the detuning off the intermediate levels. This type of non-Lorentzian resonance is distinct from the asymmetric resonance resulting from the effects of q uantum interference between competing indistinguishable dynamic pathways. The product distributions are shown to be constant near this type of resonance.