Constituents from the Stem Barks of Canarium bengalense with Cytoprotective Activity against Hydrogen Peroxide-induced Hepatotoxicity

Hoang Thi Le,나민균,Do Thi Ha,Chau Thi Anh Minh,Tae Hoon Kim,Phan Van Kiem,Nguyen Duy Thuan 대한약학회 2012 Archives of Pharmacal Research Vol.35 No.1

Phytochemical investigation of the stem barks of Canarium bengalense (Burseraceace) resulted in the isolation of a new flavone glycoside (5) together with six known compounds (1-4, 6, and 7). The chemical structure of the new compound was elucidated as 3'-hydroxy-7,4'-dimethoxyflavone-5-O-α-L-arabinofuranosyl-(1→6)-β-D-glucopyranoside by means of 1D and 2D NMR (1H-1H COSY, HMQC, and HMBC) and MS analyses. To evaluate the in vitro cytoprotective effect, the isolates (1-7) were tested against hydrogen peroxide (H2O2)-induced damage in primary cultured hepatocytes. The viability of hepatocytes was increased by treatment with each compound, except compound 1. Compounds 3, 4, and 7 exerted cytoprotective effects comparable to curcumin, the positive control. Our results suggest that the cytoprotective constituents of C. bengalense may contribute to its traditional use in the treatment of tumor and liver damage.

Microstructure and Magnetic Properties of Au-doped Finemet-type Alloy

Anh-Tuan Le,Chong-Oh Kim,Nguyen Duy Ha,Nguyen Chau,Nguyen Duc Tho,Heebok Lee 한국자기학회 2006 Journal of Magnetics Vol.11 No.1

In this report, we demonstrate a comprehensive analysis of the effects of Au addition on the microstructure and magnetic properties of Fe73.5Si13.5B9Nb₃Au₁ Finemet-type alloy. It was found that the as-quenched alloys were the amorphous state and turned into nanocrystalline state under heat treatments. The DSC analysis indicates that the sharply exothermal peak corresponding to the crystallization of the α-Fe(Si) was observed at 547- 579℃ depending on the heating rates, which is little higher than that of original Finemet (542-570℃, respectively). Besides, the thermomagnetic result confirmed that the full substitution of Cu by Au with the single phase structure in the M(T) curve along cooling cycle. Ultrasoft magnetic properties of the nanocrystallized samples were significantly enhanced by the proper annealing such as the increase of permeability and the decrease of the coercivity. The optimum annealing condition was found at the annealing temperature of 540℃ and the increase of the annealing time up to 90 min.

AFM Study and Magnetic Properties of Nanocrystalline Fe<SUB>73.5</SUB>-xCrxSi<SUB>13.5</SUB>B<SUB>9</SUB>Nb₃Au₁ (x = 1~5) Alloys

Anh-Tuan Le,Nguyen Chau,Nguyen Duy Cuong,Ngo Duc The,Chong-Oh Kim,Jang-Roh Rhee,Heebok Lee 한국자기학회 2006 Journal of Magnetics Vol.11 No.1

In this paper, the influences of microstructural and surface morphological developments on the soft magnetic properties and giant magneto-impedance (GMI) effect of the Fe73.5-xCrxSi13.5B9Nb₃Au₁ (x = 1, 2, 3, 4, 5) alloys have been presented. It was found that the Cr addition slightly decreased the mean grain size of α-Fe(Si) grains. AFM results indicate a large variation of surface morphology of density and size of protrusions along the ribbon plane due to microstructural changes caused by thermal annealing with increasing Cr content. Ultrasoft magnetic properties of the nanocrystallized samples were noticeably enhanced by properly heat treatments at Ta=540℃ such as an increase of the magnetic permeability and the decrease of coercivity, which is likely due to the formation of nanoscale α-Fe(Si) phase which reduced the magnetoelastic anisotropy of samples. Accordingly, the GMI effect was observed in the annealed samples. The correlation between the microstructure, surface morphology, and soft magnetic properties were explained by nucleation and growth model.

Effect of Annealing Temperature on the Permeability and Magneto-Impedance Behaviors of Fe<SUB>68.5</SUB>Mn<SUB>5</SUB>Si<SUB>13.5</SUB>B<SUB>9</SUB>Nb₃Cu₁ Amorphous Alloy

Anh-Tuan Le,Nguyen Duy Ha,Chong-Oh Kim,Jang-Roh Rhee,Nguyen Chau,Nguyen Quang Hoa,Nguyen Duc Tho,Heebok Lee 한국자기학회 2006 Journal of Magnetics Vol.11 No.1

The effect of annealing temperature on the permeability and giant magneto-impedance (GMI) behaviors of Fe68.5Mn5Si13.5B9Nb₃Cu₁ amorphous alloy has been systematically investigated. The nan℃rystalline Fe68.5Mn5- Si13.5B9Nb3Cu1 alloys consisting of ultra-fine (Fe,Mn)₃Si grains embedded in an amorphous matrix were obtained by annealing their precursor alloy at the temperature range from 500℃ to 600℃ for 1 hour in vacuum. The permeability and GMI profiles were measured as a function of external magnetic field. It was found that the increase of both the permeability and the GMI effect with increasing annealing temperature up to 535℃ was observed and ascribed to the ultrasoft magnetic properties in the sample, whereas an opposite tendency was found when annealed at 600℃ which is due to the microstructural changes caused by high-temperature annealing. The study of temperature dependence on the permeability and GMI effect showed some insights into the nature of the magnetic exchange coupling between nan℃rystallized grains through the amorphous boundaries in nan℃rystalline magnetic materials.

Double characteristic BNO-SPI-TENGs for robust contact electrification by vertical contact separation mode through ion and electron charge transfer

Cheedarala, Ravi Kumar,Duy, Le Chau,Ahn, Kyoung Kwan unknown 2018 Nano energy Vol.44 No.-

<P><B>Abstract</B></P> <P>• Contact-electrification is a conventional triboelectrification technique for generating current through charge transfer when two different polarized materials are brought into contact. For the first time, in-built alternate hydrophilic and hydrophobic nano channels were developed where both ionic and electronic charge transfer mechanisms were realized through contact separation mode between BNO-SPI films and PTFE. In this paper, we examined the dynamic interaction between these materials and observed adequate output performance. The novel BNO-SPI-TENGs (i.e. SO3H.BNO-SPI-TENG, SO3Li.BNO-SPI-TENG, and SO3H.TEA.BNO-SPI-TENG) produced 75V and 1µA, 43V and 0.6µA, and 9V and 0.13µA of open-circuit voltages (Voc) and short-circuit currents (Jsc) at 6Hz, respectively. Particularly, the SO3H-BNO-SPI was dramatically boosted up the performance of TENG, up to 733% of Voc and 669% of Jsc, with respect to the SO3H.TEA-BNO-SPI because the mobility of H+ ions is very high on the device surface compared to the other two Li+ and TEA bulky ions. The developed dual characteristic BNO-SPI-TENGs are very good candidates for fulfilling the need for alternate contact separation mode TENGs.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Novel double characteristic hydrophilic and hydrophobic nano channel oriented BNO-SPI films were proposed. </LI> <LI> Contact electrification process was took place on the BNO-SPI films that followed ion and electron transfer mechanisms. </LI> <LI> An electron-donor-acceptor complex mechanism was proposed for the electron transfer mechanism. </LI> <LI> High triboelectric (V<SUB>oc</SUB>) and (J<SUB>sc</SUB>) were observed from BNO-SPI-TENGs, in particular, 75V and 1µA for SO<SUB>3</SUB>H.BNO-SPI-TENG at 6Hz. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Mechanically Active Transducing Element Based on Solid-Liquid Triboelectric Nanogenerator for Self-Powered Sensing

Cong Phat Vo,M. Shahriar,Chau Duy Le,Kyoung Kwan AHN 한국정밀공학회 2019 International Journal of Precision Engineering and Vol.6 No.4

As power generation from the electronically active materials has been made remarkable progress to scavenge the ambient mechanical energy, harnessing energy from fluidics with liquid–solid contact electrification charging from the flow has become new capabilities to be applied as the sensory module. In this paper, a mechanical fluidic nanogenerator based on solid–liquid contact triboelectrification is demonstrated in which liquid electricity signal can be transferred into from the mechanical motion. This simply designed device is composed of Polytetrafluoroethylene (PTFE) tube and copper electrodes at both ends. To evaluate the effectiveness of the device, deionized water (DI) is poured into the tube and the movement is controlled by air flow from the internal volume difference of the rotating mechanism. The peak current value of the mechanical active transducing element based triboelectric nanogenerator (MAT-TENG) signal is used for analyzing movement speed. Speed gradient was applied for back and forth motion of the liquid column with a stable peak of short circuit current and open circuit voltage was about 0.23 µA and 2.31 V, respectively, at the length of the motion amplitude of 23 mm and frequency of 1 Hz. Finally, the flexible MAT-TENG has shown distinct response with the change of the motion length and speed of the liquid and the results have been achieved with better linearity ~ R2 = 0.99. Therefore, the velocity transducing can be very effective in the practical applications of the TENGs based for self-powered sensing.

Preliminary study of doxycycline adsorption from aqueous solution on alkaline modified biochar derived from banana peel

Van-Truc Nguyen,Thanh-Binh Nguyen,Thi-Dieu-Hien Vo,Nguyen Duy Dat,Thi-Kim Quyen Vo,Xuan Cuong Nguyen,Viet-Cuong Dinh,Thi-Ngoc-Chau Le,Thi-Giang-Huong Duong,Manh-Ha Bui,Xuan-Thanh Bui 대한환경공학회 2023 Environmental Engineering Research Vol.29 No.3

This study explores the adsorption of doxycycline (DOX) from aqueous solutions onto biochar derived from banana peel, which was prepared using a potassium hydroxide activation method (KOH-BPB). The biochar properties were characterized based on morphology, surface area (SBET of 710.241 ㎡ g<SUP>−1</SUP>), functional groups, and surface charge (pHPZC = 7.7). Parameters, including initial pH, DOX concentration, and ionic strength, that influenced the DOX adsorption capacity of KOH-BPB were examined. Adsorption equilibrium of DOX on KOH-BPB was assessed through four isothermal models: the Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich models. The obtained data were most compatible with the Langmuir model (R² = 0.9879). KOH-BPB has a maximum DOX absorption capacity of 121.95 mg g<SUP>-1</SUP> which exceeds that of many comparable absorbents. The maximum DOX removal was 96.7% at pH 6, a DOX concentration of 20 mg L<SUP>-1</SUP>, and a KOH-BPB dose of 1.0g L<SUP>-1</SUP>. These findings reveal that biochar from banana peel effectively removes antibiotic residues from water. This study provides a potential, low-cost, and environmentally friendly adsorbent.

A study on modeling of a hybrid wind wave energy converter system

Tri Dung Dang,Cong Binh Phan,Hoai Vu Anh Truong,Chau Duy Le,Minh Tri Nguyen,Kyoung-Kwan Ahn 제어로봇시스템학회 2016 제어로봇시스템학회 국제학술대회 논문집 Vol.2016 No.10

A model of a hybrid wind wave energy converter (HWWEC) system is proposed in this paper. The HWWEC includes two wave buoys and a vertical axis wind turbine (VAWT) system, which co-works to drive a generator. Wave buoys are arranged in an arc pattern to capture efficiently wave energy from many directions. The hydrodynamic forces are calculated by the Wave Analysis at Massachusetts Institute of Technology WAMIT software. In order to bring the system into resonance with the incident wave frequencies, a variable inertia hydraulic flywheel is employed so that the power output is maximized. Specifications and working principle of the whole system are presented and described. WEC unit model and hybrid mechanism are also presented. Simulations are carried out to evaluate the performance the HWWEC with the given specifications. Then, simulation results under some phase differences are taken to investigate the influence on the overall efficiency.