Analysis of Bulk Concentration on Double-Layer Structure for Electrochemical Capacitors

Khaing Nee Nee Khaing,Tin Tin Hla 한국재료학회 2022 한국재료학회지 Vol.32 No.7

Double-layer capacitors (DLCs) are developed with high surface electrodes to achieve a high capacitance value. In the present work, the initial bulk concentration of 1 mol/m3 and 3 mol /m3 are selected to show the consequential effects on the performance of a double-layer capacitor. A 1D model of COMSOL Multiphysics has been developed to analyze the electric field and potential in cell voltage, the electric displacement field and polarization induced by the field, and energy density in a double-layer structure. The electrostatics and the electric circuit modes in COMSOL are used to simulate the electrochemical processes in the double-layer structure. The analytical analysis of a double-layer capacitor with different initial bulk concentrations is investigated by using Poisson-Nernst-Plank equations. From the simulation results, the differential capacitance changes as a function of compact layer thickness and initial bulk concentration. The energy density varies with the differential capacitance and voltage window. The values of energy density are dominated by the interaction of ions in the solution and electrode surface.

한국어와 미얀마어의 공간형용사 ‘높다’에 대한 의미 대응연구

카잉카잉툰 ( Khaing Khaing Htun ) 한국외국어대학교 외국어교육연구소 2022 외국어교육연구 Vol.36 No.4

This paper examines the original and extended meanings of spatial adjectives ‘to be high’ in Korean and Myanmar Languages correspondingly. It presents the connection between these two adjectives including their characteristics (typical features), distinctness and usage. This corresponding study highlights the similarities and differences between the uses of spatial adjectives in these languages. As a result of comparing the basic meanings of Korean ‘높다’(to be high) and Myanmar ‘□’[mjiṉ](high) are almost the same, but there is a difference in expression of human height. In Myanmar, it is used as ‘□’[mjiṉ](high) and ‘□’[ja](long) for people's height. But in Korean, it does not match because ‘크다’(big) is used for people's height. According to the results of the corresponding study of the extended meaning of ‘높다’(to be high) in Korean and ‘□’[mjiṉ](high) in Myanmar, 5 correspondences, 6 non-correspondences, and 1 correspondence/ non-correspondence were derived out of 12. For this study, the primary data are collected from Lexicons, Korean Grammar, Myanmar Grammar, dictionaries, novels and articles. The principle of spatial adjectives are described and the similarities and differences of the two languages are also analyzed. ‘to be high’ and ‘□’[mjiṉ](high) are studied intensely in this study. It observes that the Korean ‘높다’(to be high)is not used to express a person’s height, but in Myanmar language ‘□’[mjiṉ](high) indicates a person’s height which convey the same meaning of ‘to be high’. The result shows that there are many similarities even while the different types of change from extension to abstractness. This study will help the students who learn Korean and Myanmar languages to understand the adjectives ‘to be high’ easily. It will also contribute to the study of the Korean spatial adjectives.

Inferring variance and invariance in multi-individual behavior of zebrafish (Danio rerio) responding to chemical stress

Kha Quang Quach,김형수,Tuyen Van Nguyen,Chunlei Xia,조운석,전태수 한국통합생물학회 2015 Animal cells and systems Vol.19 No.4

Variance and invariance residing in multi-individual movement of zebrafish under chemical stress were addressed concurrently before and after treatment with formaldehyde. Variance was observed in movement parameters. Without treatment, linear speed was highest in groups with two-individuals, followed by those with one- and four-individuals. Following treatment, linear speed decreased significantly in groups with one- and two-individuals, but not in those with four-individuals. Inter-distances between two-individuals in groups with two-individuals decreased markedly after treatment, whereas inter-distances between two randomly selected individuals in the groups with four-individuals were not affected. The zero- and peak-values in the time-lag of autocorrelation of inter-distances decreased further after treatment in groups of two individuals relative to those in groups of four individuals. However, the empirical transition probability matrix between predefined behavioral patterns remained invariant among groups with different numbers of individuals as well as before and after treatment. Variance and invariance in multi-individual behaviors are suitable in expressing complex behaviors under chemical stress and could be a reference for detecting contaminants in the environment using indicator species.

IRS-aided NOMA for Rate Fairness in Downlink Networks

Kha-Hung Nguyen,Hieu V. Nguyen,Oh-Soon Shin 한국통신학회 2020 한국통신학회 학술대회논문집 Vol.2020 No.11

N-Terminal Modifications of Ubiquitin via Methionine Excision, Deamination, and Arginylation Expand the Ubiquitin Code

Kha The Nguyen,주신영,Sang-Yoon Kim,이창석,Cheolju Lee,Cheol-Sang Hwang 한국분자세포생물학회 2022 Molecules and cells Vol.45 No.3

Ubiquitin (Ub) is post-translationally modified by Ub itself or Ub-like proteins, phosphorylation, and acetylation, among others, which elicits a variety of Ub topologies and cellular functions. However, N-terminal (Nt) modifications of Ub remain unknown, except the linear head-to-tail ubiquitylation via Nt-Met. Here, using the yeast Saccharomyces cerevisiae and an Nt-arginylated Ub-specific antibody, we found that the detectable level of Ub undergoes Nt-Met excision, Nt-deamination, and Nt-arginylation. The resulting Nt-arginylated Ub and its conjugated proteins are upregulated in the stationary-growth phase or by oxidative stress. We further proved the existence of Nt-arginylated Ub in vivo and identified Nt-arginylated Ub-protein conjugates using stable isotope labeling by amino acids in cell culture (SILAC)-based tandem mass spectrometry. In silico structural modeling of Nt-arginylated Ub predicted that Nt-Arg flexibly protrudes from the surface of the Ub, thereby most likely providing a docking site for the factors that recognize it. Collectively, these results reveal unprecedented Nt-arginylated Ub and the pathway by which it is produced, which greatly expands the known complexity of the Ub code.

Enhanced electromechanical performance of P(VDF-TrFE-CTFE) thin films hybridized with highly dispersed carbon blacks

Kha Tu, Nguyen Dien,Noh, Myoung-Sub,Ko, Youngpyo,Kim, Jong-Ho,Kang, Chong Yun,Kim, Heesuk Elsevier 2018 Composites Part B, Engineering Vol.152 No.-

<P><B>Abstract</B></P> <P>The fluoride-based electrostrictive terpolymers are attractive in electromechanical applications. To obtain high electromechanical performance, the terpolymers are hybridized with various fillers such as carbon materials. However, the previous hybrid films have been fabricated with thickness of 20–100 μm due to poor dispersion of the fillers, indicating that these electrostrictive films require high driving voltages of more than 200 V. Herein, we have demonstrated the electrostrictive P(VDF-TrFE-CTFE) thin film hybridized with highly dispersed carbon blacks (CB). The CBs were chemically oxidized to improve the dispersion in the polymer matrix, thus leading to a successful fabrication of the oxidized CB/P(VDF-TrFE-CTFE) hybrid films with 8 μm thickness using solution casting method. The P(VDF-TrFE-CTFE) thin film with 2.75 wt% oxidized CB shows 1.6 fold increased dielectric constant and maximum polarization with low loss factor compared to the pure terpolymer. These enhancements of the 8 μm thick hybrid film enable to yield useful mechanical output at low driving voltages below 100 V. To evaluate the electromechanical performance of hybrid thin films, a unimorph cantilever was fabricated. With a low applied voltage of 90 V, the cantilever based on P(VDF-TrFE-CTFE) thin film with 2.75 wt% oxidized CB produces a displacement twice as high as that of the pure terpolymer. These results provide the first feasibility study of electrostrictive composites for practical applications, particularly human-related applications requiring a low driving voltage.</P>

Control of protein degradation by N-terminal acetylation and the N-end rule pathway

Kha The Nguyen,문상현,이창석,황철상 생화학분자생물학회 2018 Experimental and molecular medicine Vol.50 No.-

Nα-terminal acetylation (Nt-acetylation) occurs very frequently and is found in most proteins in eukaryotes. Despite the pervasiveness and universality of Nt-acetylation, its general functions in terms of physiological outcomes remain largely elusive. However, several recent studies have revealed that Nt-acetylation has a significant impact on protein stability, activity, folding patterns, cellular localization, etc. In addition, Nt-acetylation marks specific proteins for degradation by a branch of the N-end rule pathway, a subset of the ubiquitin-mediated proteolytic system. The N-end rule associates a protein’s in vivo half-life with its N-terminal residue or modifications on its N-terminus. This review provides a current understanding of intracellular proteolysis control by Nt-acetylation and the N-end rule pathway.

Effect of Torrefaction on Chemical Characteristics and Grindability of Lignocellulosic Biomass

( Dao Kha Giang ),( Jae-won Lee ) 한국목재공학회 2020 한국목재공학회 학술발표논문집 Vol.2020 No.1

In this study, larch and yellow poplar were torrefied in bench scale tubular reactor at 220, 250 and 280°C with residence time 50 min. Effect of torrefaction on properties, chemical composition, grandability and microstructure and morphology of biomass was observed depending on torrefaction conditions. Chemical composition of torrefied biomass changed significantly with increase of torrefaction seversity. The grindability of larch and yellow poplar were improved by torrefaction treatment. XRD analysis revealed that the degradation of amorphous hemicellulose and amorphous regions of cellulose resulted in increases of crystallinity of torrefied biomass. The color of the torrefied biomass was darker with increasing temperature.

Optimization of efficient protocorm-like body (PLB) formation of Phalaenopsis and Dendrobium hybrids

Soe, Khaing Wah,Myint, Khin Thida,Naing, Aung Htay,Kim, Chang Kil Institute of Agricultural Science and Technology 2014 慶北大農學誌 Vol.32 No.4

Optimization of the protocorm-like body (PLB) formation of Phalaenopsis and Dendrobium hybrids was performed by determining the effects of plant growth regulators (PGRs) and different parts and division sizes of the PLB. For both genera, the base part was the best for the proliferation of PLBs, yielding the highest number of PLBs on a PGR-free medium for Phalaenopsis and medium containing $0.1{\mu}M$ NAA and $10.0{\mu}M$ BAP for Dendrobium. As regards the division size, four-division sections resulted in a higher PLB formation efficiency for Phalaenopsis, while two-division sections produced a higher PLB formation efficiency for Dendrobium. It is expected that these findings will be applicable to efficient PLB formation of other Phalaenopsis and Dendrobium orchids.

Molecular identification of four Panonychus species (Acari: Tetranychidae) in Korea, including new records of P. caglei and P. mori

TINMOE KHAING,심재경,이경열 한국곤충학회 2015 Entomological Research Vol.45 No.6

Four species of the genus Panonychus are identified in Korea including two previously known species P. citri (McGregor) and P. ulmi (Koch) and two newly identified species P. mori Yokoyama and P. caglei Mellot. Morphological diagnostics were observed among the four species in the color of dorsal tubercles and in the shape of male aedeagus. The dorsal tubercles of P. citri, P. ulmi, P. mori and P. caglei are red, white, whitish red and light red, respectively. The aedeagi of male adults are diagnostic in sigmoid‐shaped at the distal end and its shape and length was different among four species. Molecular comparison of the internal transcribed spacer 2 (ITS2) sequence of nuclear DNA and cytochrome‐c oxidase subunit I (COI) nucleotide sequence of mitochondrial DNA among the four species showed divergences 8–12% and 9–12%, respectively. Molecular analysis of the ITS2 and COI sequences revealed their divergences were slightly different among four species. In addition, species‐specific primer sets were designed at the base on ITS2 sequences to precisely diagnose these four species at the molecular level.