Synthesis of Poly(methacrylic acid)-functionalized SBA-15 and its Adsorption of Phenol in Aqueous Media

Vo, Vien,Kim, Hee-Jin,Kim, Ha-Yeong,Kim, Youngmee,Kim, Sung Jin Korean Chemical Society 2013 Bulletin of the Korean Chemical Society Vol.34 No.12

Poly(methacrylic acid)-functionalized SBA-15 silicas (denoted as P-x-PMA/SBA-15 where x is molar ratio of TSPM/(TEOS+TSPM) in percentage in the initial mixture) were synthesized by co-condensation of tetraethoxysilane and varying contents of 3-(trimethoxysilyl)propyl methacrylate in acidic medium with the block copolymer Pluronic 123 as a structure directing agent and then polymerization by methacrylic acid in the presence of ammonium persulfate as an initiator. The functionalized materials were characterized by PXRD, TEM, SEM, IR, and $N_2$ adsorption-desorption at 77 K. The investigation of phenol adsorption in aqueous solution on the materials showed that the poly(methacrylic acid)-functionalized mesoporous silicas possess strong adsorption ability for phenol with interaction of various kinds of hydrogen bonds. The adsorption data were fitted to Langmuir isotherms and the maximum adsorption capacity of the three functionalized materials P-5-PMA/SBA-15, P-10-PMA/SBA-15, and P-15-PMA/SBA-15 to be 129.37 mg/g, 187.97 mg/g, and 78.43 mg/g, respectively, were obtained. The effect of the pH on phenol adsorption was studied.

Impact of Corporate Social Responsibility on Repurchase Intention: A Case Study in the FMCG Industry in Vietnam

Minh Sang VO(Minh Sang VO ),Minh Quoc PHAM(Minh Quoc PHAM ),Thuy Bao Thu LE(Thuy Bao Thu LE ),Le Kim Ngan NGUYEN(Le Kim Ngan NGUYEN ),Xuan Tung DAO(Xuan Tung DAO ),Huynh To Nhi PHAM(Huynh To Nhi PHAM 한국유통과학회 2023 The Journal of Asian Finance, Economics and Busine Vol.10 No.2

The study aims to evaluate the impact of corporate social responsibility on customers’ repurchase intention in Vietnam’s fast-moving consumer goods (FMCG) industry. This study employs primary data surveyed from 417 Vietnamese consumers, and the sample is selected based on the willingness to participate in providing information. The results show corporate social responsibility’s positive impact on repurchase intention in the FMCG industry in the Vietnam market. There are three components of corporate social responsibility, including ethical responsibility, legal responsibility, and economic responsibility have a positive impact on repurchase intention. The economic responsibility component has the greatest effect on repurchase intention. There is not enough statistical basis for the philanthropic responsibility component of corporate social responsibility to recognize its impact on repurchase intention. The findings of this study suggest that companies dealing in the FMCG industry in Vietnam need to invest more in further developing their corporate social responsibility, it not only helps to improve their customer loyalty to businesses but also contributes to promoting the country’s economic and social development in a better and more sustainable direction.

DRG2 Deficient Mice Exhibit Impaired Motor Behaviors with Reduced Striatal Dopamine Release

Lim, Hye Ryeong,Vo, Mai-Tram,Kim, Dong Jun,Lee, Unn Hwa,Yoon, Jong Hyuk,Kim, Hyung-Jun,Kim, Jeongah,Kim, Sang Ryong,Lee, Jun Yeon,Yang, Chae Ha,Kim, Hee Young,Choi, June-Seek,Kim, Kijeong,Yang, Esther MDPI AG 2020 INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES Vol.21 No.1

<P>Developmentally regulated GTP-binding protein 2 (DRG2) was first identified in the central nervous system of mice. However, the physiological function of DRG2 in the brain remains largely unknown. Here, we demonstrated that knocking out DRG2 impairs the function of dopamine neurons in mice. DRG2 was strongly expressed in the neurons of the dopaminergic system such as those in the striatum (Str), ventral tegmental area (VTA), and substantia nigra (SN), and on neuronal cell bodies in high-density regions such as the hippocampus (HIP), cerebellum, and cerebral cortex in the mouse brain. DRG2 knockout (KO) mice displayed defects in motor function in motor coordination and rotarod tests and increased anxiety. However, unexpectedly, DRG2 depletion did not affect the dopamine (DA) neuron population in the SN, Str, or VTA region or dopamine synthesis in the Str region. We further demonstrated that dopamine release was significantly diminished in the Str region of DRG2 KO mice and that treatment of DRG2 KO mice with l-3,4-dihydroxyphenylalanine (L-DOPA), a dopamine precursor, rescued the behavioral motor deficiency in DRG2 KO mice as observed with the rotarod test. This is the first report to identify DRG2 as a key regulator of dopamine release from dopamine neurons in the mouse brain.</P>

Pyrolysis characteristics and kinetics of microalgal <i>Aurantiochytrium</i> sp. KRS101

Vo, The Ky,Ly, Hoang Vu,Lee, Ok Kyung,Lee, Eun Yeol,Kim, Chul Ho,Seo, Jeong-Woo,Kim, Jinsoo,Kim, Seung-Soo Pergamon Press 2017 Energy Vol.118 No.-

<P><B>Abstract</B></P> <P>Microalgae have recently attracted tremendous attention as a possible feedstock for biofuel production. In this study, the pyrolysis characteristics and kinetics of <I>Aurantiochytrium</I> sp. KRS101, a kind of heterotrophic oleaginous microalgae, were investigated by means of thermogravimetric analysis and pyrolysis in a micro-tubing reactor. Most biochemical components of the microalgae (carbohydrates, proteins, and lipids) were decomposed between 150 and 600 °C at heating rates of 5–20 °C/min. Derivative thermogravimetry (DTG) curves were deconvoluted to more fully understand the separate decompositions of carbohydrates, proteins, and lipids. Experimental results of pyrolysis in the micro-tubing reactor were consistent with the predictions of the proposed lumped kinetic model, and the kinetic rate constants indicated that the predominant reaction pathway under the investigated pyrolysis conditions was from biomass to bio-oil rather than from biomass to gas.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Systematic study and first attempt at pyrolysis of <I>Aurantiochytrium</I> sp. KRS101. </LI> <LI> Investigation of pyrolysis characteristics and kinetics by means of non-isothermal TGA and isothermal pyrolysis experiments. </LI> <LI> Study of the influence of pyrolysis conditions upon product yield distribution and composition. </LI> <LI> Application of a quantitative kinetic model and mechanism study for pyrolysis of microalgae. </LI> </UL> </P>

Highly CO selective Cu(I)-doped MIL-100(Fe) adsorbent with high CO/CO₂ selectivity due to π complexation: Effects of Cu(I) loading and activation temperature

Vo, The Ky,Bae, Youn-Sang,Chang, Bong-Jun,Moon, Su-Young,Kim, Jeong-Hoon,Kim, Jinsoo Elsevier 2019 Microporous and mesoporous materials Vol.274 No.-

<P><B>Abstract</B></P> <P>Cu(I) doping of octahedral MIL-100(Fe) was successfully performed by means of impregnation and consequent reduction under vacuum conditions. Although MIL-100(Fe) adsorbed CO<SUB>2</SUB> better than CO, Cu(I)@MIL-100(Fe) showed selective CO adsorption compared to CO<SUB>2</SUB> owing to π complexation between CO and Cu(I). Effects of Cu(I) loading concentration, activation temperature, and adsorption temperature upon CO/CO<SUB>2</SUB> adsorption properties were systematically investigated. The adsorption behaviors of CO and CO<SUB>2</SUB> on MIL-100(Fe) and Cu(I)@MIL-100(Fe) were well described by the dual-site Langmuir–Freundlich (DSLF) model. Ideal adsorbed solution theory (IAST) was used to predict adsorption isotherms of equimolar CO and CO<SUB>2</SUB> mixtures and to predict CO/CO<SUB>2</SUB> selectivities as a function of bulk pressure. The obtained results showed that 45 wt% Cu(I)-doped MIL-100(Fe) had CO adsorption capacity of 3.10 mmol g<SUP>−1</SUP> and CO/CO<SUB>2</SUB> selectivity of 420 at 298 K and 1 bar. In addition, a large CO working capacity of 1.39 mmol g<SUP>−1</SUP> was observed for 45 wt% Cu(I)-doped MIL-100(Fe) in the pressure range of 10–100 kPa. Cu(I)-doped MIL-100(Fe) thus appears promising as an adsorbent material for effective CO/CO<SUB>2</SUB> separation.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Cu(I) was doped onto MIL-100(Fe) for highly selective adsorption of CO compared to CO<SUB>2</SUB>. </LI> <LI> The effects of metal loading, activation temperature, and adsorption temperature were investigated. </LI> <LI> Cu(I)@MIL-100(Fe) exhibited the high CO adsorption capacity of 3.10 mmol g<SUP>−1</SUP>. </LI> <LI> The IAST prediction of CO/CO<SUB>2</SUB> selectivity was 420 at 298 K and 1 bar. </LI> <LI> The CO working capacity of 1.39 mmol g<SUP>−1</SUP> was obtained for 45Cu(I)@MIL-100(Fe). </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Additional effects of bisphenol A and paraben on the induction of calbindin-D(9K) and progesterone receptor via an estrogen receptor pathway in rat pituitary GH3 cells.

Kim, S M,Jung, E M,An, B S,Hwang, I,Vo, T T,Kim, S R,Lee, S M,Choi, K C,Jeung, E B The Society 2012 Journal of physiology and pharmacology Vol.63 No.5

<P>There are concerns about the combined estrogenic effects of chemicals since mixtures of these chemicals exist in our environment. This study investigated potential additional interactions between bisphenol A (BPA) and isobutylparaben (IBP), which are major xenoestrogens used in the manufacture of plastics, cosmetics, drugs, and other products. The combined effects of these two chemicals were analyzed by measuring the expression of calbindin-D(9k) (CaBP-9k) in rat pituitary cancer GH3 cells. GH3 cells were treated with single and combination doses of both chemicals (BPA single doses: 10(-7), 10(-6) and 10(-5) M; IBP single doses: 10(-7), 10(-6) and 10(-5) M, and each of the BPA and IBP doses combined). Prior to treatment, cells were temporarily transfected with a plasmid containing an ERE-luciferase reporter gene. Luciferase activity was measured as an indicator of ER activation by 17β-estradiol (E2), BPA, and IBP. BPA (10(-5) M) combined with IBP (10(-7) M and 10(-6) M) induced a significant increase in the luciferase activity. Twenty-four hours after treatment, dose-dependent effects were observed in both single and combined dose groups, and several combination doses induced significant increases in the expression of CaBP-9k and progesterone receptor (PR) at both transcriptional and translational levels. Pre-treatment with ICI 182,780, a pure estrogen antagonist, significantly reversed BPA- and IBP-induced CaBP-9k and PR upregulation in GH3 cells. Taken together, these results indicate that BPA and IBP may have additionally increased estrogenic potency via an estrogen receptor-mediated pathway.</P>

Exploring scavenger receptor class F member 2 and the importance of scavenger receptor family in prediagnostic diseases

Vo Thuy-Trang T.,Kong Gyeyeong,Kim Chaeyeong,Juang Uijin,Gwon Suhwan,Jung Woohyeong,Nguyen Huonggiang,Kim Seon-Hwan,Park Jongsun 한국독성학회 2023 Toxicological Research Vol.39 No.3

Scavenger Receptor Class F Member 2 (SCARF2), also known as the Type F Scavenger Receptor Family gene, encodes for Scavenger Receptor Expressed by Endothelial Cells 2 (SREC-II). This protein is a crucial component of the scavenger receptor family and is vital in protecting mammals from infectious diseases. Although research on SCARF2 is limited, mutations in this protein have been shown to cause skeletal abnormalities in both SCARF2-deficient mice and individuals with Van den Ende-Gupta syndrome (VDEGS), which is also associated with SCARF2 mutations. In contrast, other scavenger receptors have demonstrated versatile responses and have been found to aid in pathogen elimination, lipid transportation, intracellular cargo transportation, and work in tandem with various coreceptors. This review will concentrate on recent progress in comprehending SCARF2 and the functions played by members of the Scavenger Receptor Family in pre-diagnostic diseases.

Genetically engineered hybrid poplars for the pyrolytic production of bio-oil: Pyrolysis characteristics and kinetics

Vo, The Ky,Cho, Jin-Seong,Kim, Seung-Soo,Ko, Jae-Heung,Kim, Jinsoo Pergamon 2017 Energy Conversion and Management Vol. No.

<P><B>Abstract</B></P> <P>In this study, hybrid poplars were genetically engineered to increase their biomass volume and change their biochemical composition to improve the pyrolytic production of bio-oil. Wild-type hybrid poplars (WT) and genetically engineered hybrid poplars (TP) were comparatively investigated with regard to their pyrolysis characteristics and kinetics via thermogravimetric analysis (TGA) and isothermal pyrolysis within a micro-tubing reactor. Model-free methods were used to determine the activation energy for the thermal decomposition of the WT and TP samples. The results showed that the activation energy of the WT sample was always greater than that of the TP sample at the same level of conversion. Isothermal pyrolysis experiments of the two biomass samples were performed at various temperatures (360–400°C) and durations (1–5min) using a micro−tubing reactor. The pyrolytic product distributions and chemical compositions were compared. The obtained results showed that the TP sample yielded a higher quantity of bio-oil compared to the WT sample under the same conditions with different chemical compositions. A reaction network and quantitative kinetic model were proposed for pyrolysis of the WT and TP samples. Kinetic parameters were obtained through an optimization function and used to explore the parameter space in order to predict product yields as a function of reaction time and temperature for both WT and TP feedstocks.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Genetic modification of hybrid poplars to improve the pyrolytic production of bio-oil. </LI> <LI> Pyrolysis characteristics and kinetics of wild-type and transgenic hybrid poplars. </LI> <LI> Lower activation energy and higher bio-oil yield after genetic modification. </LI> <LI> Application of a kinetic model to predict pyrolytic product yields. </LI> </UL> </P>

Surfactant-assisted ammonium vanadium oxide as a superior cathode for calcium-ion batteries

Vo, Thuan Ngoc,Kim, Hyeongwoo,Hur, Jaehyun,Choi, Wonchang,Kim, Il Tae The Royal Society of Chemistry 2018 Journal of materials chemistry. A, Materials for e Vol.6 No.45

<P>Ammonium vanadium oxide (NH4V4O10) was adopted as an efficient and high-capacity cathode for Ca-ion batteries. The conventional hydrothermal process allowed an NH4V4O10 cathode to exhibit an initial capacity of 125 mA h g<SUP>−1</SUP> at 0.1 A g<SUP>−1</SUP>. However, the process led to a size range of hundreds of nanometers to a few microns, which limited the electrochemical performance. Accordingly, we created uniform rod-like NH4V4O10 particles approximately 100 nm in breadth by adding the surfactant sodium dodecylbenzenesulfonate as a soft template during the sample preparation. The addition of the surfactant not only reduced the crystal size but also generated an Na-doping effect; as a result, it increased the proportion of V<SUP>4+</SUP>/V<SUP>5+</SUP> active sites. The Na-doped NH4V4O10 electrode delivered an initial capacity of 150 mA h g<SUP>−1</SUP> and maintained the capacity by demonstrating coulombic efficiencies of 90-95% without notable fading after 100 cycles in a three-electrode system. Moreover, the material produced <I>via</I> the new route required less time to be activated before reaching the highest-capacity state. <I>Ex situ</I> X-ray diffraction analysis indicated the formation of new phases during the migration of Ca ions, and the small change in the lattice plane suggested that NH4V4O10 can exhibit stable electrochemical performance during prolonged cycling. Finally, a full-cell study demonstrated that the Na-doped NH4V4O10 electrode delivered a maximum discharging capacity of 75 mA h g<SUP>−1</SUP> with both high coulombic efficiency (∼80%) and ∼100% capacity retention for 100 cycles.</P>

Application to Speed Control of Brushless DC Motor Using Mixed H₂/H<SUB>∞</SUB> PID Controller with Genetic Algorithm

VO HOANG DUY,NGUYEN HUNG,SANG-KWUN JEONG,HAK-KYEONG KIM,SANG-BONG KIM 한국해양공학회 2008 韓國海洋工學會誌 Vol.22 No.4

This paper proposes a mixed H₂/H∞ optimal PID controller with a genetic algorithm based on the dynamic model of a brushless direct current (BLDC) motor and applies it to speed control. In the dynamic model of the BLDC motor with perturbation, the proposed controller guarantees arobust and optimal tracking performance to the desired speed of the BLDC motor. A genetic algorithm was used to obtain parameters for the PID controller that satisfy the mixed H2/H∞ constraint. To implement the proposed controller, a control system based on PIC18F4431 was developed. Numerical and experimental results are shown to prove that the performance of the proposed controller was better than that of the optimal PID controller.