• Applied Chemistry for Engineering
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• v.33 no.1
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• pp.28-37
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• 2022

The lignite and bituminous coal are mainly used in thermal power plant. They exhaust green house gas (GHG) such as CO₂, and become deplete, thus require alternative energy resources. To solve the problem, the hydrochar production from biomass is suggested. In this study, both hydrothermal carbonization (HTC) and solvothermal carbonization (STC) were used to produce high quality hydrochar. To improve the reactivity of water solvent process in HTC, STC process was conducted using ethanol solution. The experiments were carried out by varying the solid-liquid ratio (1:4, 1:8, 1:12), reaction temperature (150~300 ℃) and retention time (15~120 min) using kenaf. The characteristic of hydrochar was analyzed by EA, FT-IR, TGA and SEM. The carbon content of hydrochar increased up to 48.11%, while the volatile matter decreased up to 39.34%. Additionally, the fuel characteristic of hydrochar was enhanced by reaction temperature. The results showed that the kenaf converted to a fuel by HTC and STC process, which can be used as an alternative energy source of coal.

• Applied Chemistry for Engineering
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• v.34 no.4
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• pp.331-346
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• 2023

Recently, green processes that can be directly used in an energy-efficient and electrified society to achieve carbon neutrality are attracting attention. Existing heat and pressure-based desalination technologies that consume tremendous amounts of energy are no exception, and the growth of next-generation electrochemical-based desalination technologies is remarkable. One of the most representative electrochemical desalination technologies is electrochemical ion separation (EIONS) technology, which includes capacitive desalination (CDI) and battery desalination (BD) technology. In the research field of EIONS, various system applications have been developed to improve system performance, such as capacity and cyclability. However, it is very difficult to understand the meaning and novelty of these applications immediately because there are only a few papers that summarize the research background for domestic readers. Therefore, in this review paper, we aim to describe the technological advances and individual characteristics of each system in clear and specific detail about the latest EIONS research. The driving principle, research background, and strengths and weaknesses of each EIONS system are explained in order. In addition, this paper concluded by suggesting the future development and research direction of EIONS. Researchers who are just beginning out in EIONS research can also benefit from this study because it will help them understand the research trend.

• Journal of Applied Biological Chemistry
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• v.66
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• pp.519-526
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• 2023

Present study explored immunostimulatory effects of Astragalus membranaceus and Zanthoxylum schinifolium 1:1 (w:w) mixture (AZM-1:1) in Raw264.7 cells, mouse macrophage derived cells. Treatment with 100-400 ㎍/mL of AZM-1:1 in Raw264.7 cells significantly increased nitric oxide production in parallel with inducible nitric oxide synthase mRNA expression without affecting cytotoxicity. In addition, AZM-1:1 dose-dependently increased prostaglandin E₂ production in conditioned medium along with cyclooxygenase-2 mRNA induction. Moreover, AZM-1:1 induces the transcription of tumor necrosis factor-α, interleukin-1β, interleukin-6, and monocyte chemoattractant protein-1. Immunoblot analyses revealed that AZM-1:1 significantly increased the phosphorylation of mitogen-activated protein kinases, provoked phosphorylation-mediated degradation of inhibitory-κBα, and phosphorylated p65. Furthermore, treatment with AZM-1:1 promoted phagocytosis of Escherichia coli particle labeled with green fluorescence. Taken together, AZM-1:1 may be a promising nutraceutical for stimulation the innate immune system, including macrophages.

• Journal of Microbiology and Biotechnology
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• v.26 no.1
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• pp.1-8
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• 2016

The new movement towards green chemistry and renewable feedstocks makes microbial production of chemicals more competitive. Among the numerous chemicals, organic acids are more attractive targets for process development efforts in the renewable-based biorefinery industry. However, most of the production costs in microbial processes are higher than that in chemical processes, among which over 60% are generated by separation processes. Therefore, the research of separation and purification processes is important for a promising biorefinery industry. This review highlights the progress of recovery processes in the separation and purification of organic acids, including their advantages and disadvantages, current situation, and future prospects in terms of recovery yields and industrial application.

• Journal of Microbiology and Biotechnology
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• v.26 no.1
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• pp.151-159
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• 2016

Nanoparticles have wide-scale applications in various areas, including medicine, chemistry, electronics, and energy generation. Several physical, biological, and chemical methods have been used for synthesis of silver nanoparticles. Green synthesis of silver nanoparticles using plants provide advantages over other methods as it is easy, efficient, and eco-friendly. Nanoparticles have been extensively studied as potential antimicrobials to target pathogenic and multidrug-resistant microorganisms. Their applications recently extended to development of antivirals to inhibit viral infections. In this study, we synthesized silver nanoparticles using Cinnamomum cassia (Cinnamon) and evaluated their activity against highly pathogenic avian influenza virus subtype H7N3. The synthesized nanoparticles were characterized using UVVis absorption spectroscopy, scanning electron microscopy, and Fourier transform infrared spectroscopy. Cinnamon bark extract and its nanoparticles were tested against H7N3 influenza A virus in Vero cells and the viability of cells was determined by tetrazolium dye (MTT) assay. The silver nanoparticles derived from Cinnamon extract enhanced the antiviral activity and were found to be effective in both treatments, when incubated with the virus prior to infection and introduced to cells after infection. In order to establish the safety profile, Cinnamon and its corresponding nanoparticles were tested for their cytotoxic effects in Vero cells. The tested concentrations of extract and nanoparticles (up to 500 μg/ml) were found non-toxic to Vero cells. The biosynthesized nanoparticles may, hence, be a promising approach to provide treatment against influenza virus infections.

• Textile Coloration and Finishing
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• v.28 no.2
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• pp.57-62
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• 2016

We have synthesized five novel phthaloperinone dyes via a condensation reaction to be applied as yellow colorants for liquid crystal display(LCD) color filters. The reaction between 1,8-naphthalic anhydride(1a), 4-chloro-1,8-naphthalic anhydride(1b), 4-bromo-1,8-naphthalic anhydride(1c), 3-nitro-1,8-naphthalic anhydride(1d), 4-nitro-1,8-naphthalic anhydride(1e) and 1,2-diaminoanthraquinone(2) proceeded readily giving a product in 72-88% yields. The synthesized dyes were characterized by UV-Vis, mass spectrometry and elemental analysis. The spectral properties and thermal stability of the dyes were examined. The dyes absorb at around 400-450nm. All five dyes showed satisfactory thermal stability: the dyes retain 99-100% of its original weight at $300^{\circ}C$, 98-100% at $350^{\circ}C$, 92-98% at $400^{\circ}C$, and 84-92% at $450^{\circ}C$. We have quantitatively evaluated the reaction mechanism and reactivity of dye molecules by means of Pariser-Parr-Pople Molecular Orbital Method(PPP-MO).

• Journal of the Korean Electrochemical Society
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• v.17 no.2
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• pp.79-85
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• 2014

Silicon (Si) has been investigated as promising negative-electrode (anode) materials because its theoretical specific capacity of 4200 mAh/g for $Li_{4.4}Si$ is far higher than that of carbonaceous anodes in current commercial products. However, in practice, the application of Si to Li-ion batteries is still quite challenging because Si suffers from severe volume expansion and contraction and lead to a continuous solid electrolyte interphase (SEI)-filming process by cracking of Si. This process consumes the limited $Li^+$ source, builds up thick and unstable SEI layer on the Si active materials, and will eventually disable the cell. Since unstable SEI reduces electrochemical performance and thermal stability of the Si anode, the surface chemistry of the anode should be modified by using a functional additive. It is found that lithium bis(oxalato)borate (LiBOB) as an additive effectively protected the Si anode surface, improved capacity retention when stored at $60^{\circ}C$, and alleviated exothermic thermal reactions of fully lithiated Si anode.

• Membrane Journal
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• v.23 no.6
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• pp.432-438
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• 2013

Mixed-matrix membranes (MMMs) containing MIL-100(Fe), a MOF type, were fabricated in this study. MMMs up to 30 wt% MOF loading were prepared, and their gas permeabilities were tested. $H_2$, $CO_2$, $O_2$, $N_2$, and $CH_4$ gas permeabilities increased with the MOF loading, while $SF_6$, the largest kinetic diameter in this study, exhibited reduction of gas permeability with the loading. Ideal gas selectivity of $N_2/SF_6$ improved by 40% as compared with pure polyimide membrane, suggesting the proposed MMMs were suitable for $N_2/SF_6$ separation.

• Journal of Environmental Science International
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• v.24 no.12
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• pp.1583-1590
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• 2015

The aim of this study was to examine the morphological responses of Hosta longipes, an ornamental plants for heavy metal contaminated soils in urban landscaping, to heavy metals Cd, Pb, and Zn. Plants were grown in artificial soil amended with Cd, Pb, and Zn at concentation of 0, 100, 250, and 500 mg/kg. Plant height, leaf length, leaf width, total leaf number, deaf leaf number, new leaf number, chlorophyll contents, and ornamental value were monitored from May to August. At 4 months after planting, the survival and morphological responses of H. longipes grown in soil amended with Cd at concentrations ${\geq}100mg/kg$ were severely affected compared to those grown in the control soil. Relative leaf length rate and relative leaf width rate were significantly decreased when the concentration of Pb was increased. Total leaf number, chlorophyll contents, and ornamental value were the lowest value in plants grown in soil amended with Pb at level of 500 mg/kg. Relative leaf length rate and relative leaf width rate, total leaf number, dead leaf number, new leaf number, and ornamental values had a tendency of decrease when plants were grown in soils amended with Zn. However, no significant difference was found among treatments except for plants were grown in soils amended with 500 mg/kg Zn. Therefore, Hosta longipes might be useful for phytoremediation of Zn contaminated sites as herbaceous ornamental plants.

• Journal of the Korean Ceramic Society
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• v.39 no.3
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• pp.299-307
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• 2002

In this proposed study, a new emerging shape forming technique Direct Coagulation Casting(DCC) which enables to fabricate complex-shaped ceramic parts has been investigated using colloid surface chemistry. Various process variables affected by dispersant, coagulation agent and sintering additives, have been evaluated in order to achieve highly concentrated stabilized silicon nitride suspensions. A high solid loading of 51 vol% in the dispersed silicon nitride suspension was prepared with 1.0wt% Tetraethylammonium Hydroxide (TEAH), which obtained a stable silicon nitride suspension with sintering additives $(Al_2O_3\;and\;Y_2O_3)$ in alkaline regions. The addition of hydroxyaluminium diacetate into the suspension, which decomposed at elevated temperatures, led to coagulate of a silicon nitride suspension. In a basic medium, aluminum ions precipitated to aluminum hydroxide $(Al(OH)_3)$, leading to decreased $OH^-$ concentration and, thus, coagulated suspension.