Facile synthesis of multifunctional Ag/Fe3O4-CS nanocomposites for antibacterial and hyperthermic applications

Ngoan Thi Nguyen,Dai Lam Tran,Duc Cuong Nguyen,Thai Loc Nguyen,Thi Cham Ba,Binh Hai Nguyen,Thi Duong Ba,Nam Hong Pham,Dzung Tuan Nguyen,Thai Hoa Tran,Gia Dien Pham 한국물리학회 2015 Current Applied Physics Vol.15 No.11

Nanocomposites containing two or more functional constituents are attractive candidates for advanced nanomaterials. In this study, multifunctional Ag/Fe3O4-CS nanocomposites were successfully prepared, using chitosan as a stabilizing and cross-linking agent. The as-synthesized nanocomposites were characterized by Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), Energy-dispersive X-ray spectroscopy (EDS), UVevisible spectrophotometer (UVeVis) and vibrating sample magnetometer (VSM). The results demonstrated that Ag/Fe3O4-CS composite nanoparticles (NPs) were composed of parent components, Fe3O4 and Ag NPs, which were uniformly dispersed in the chitosan matrix. The hybrid NPs exhibited strong antibacterial property against Pseudomonas aeruginosa. With high magnetization value (67 emu/g), the synthesized Ag/Fe3O4-CS composite can be easily separated or recycled in potential biomedical applications. Furthermore, the results showed that the multicomponent hybrid nanostructures appeared to be the promising material for local hyperthermia, which can be used as thermoseeds for localized hyperthermia treatment of cancers.

Development of honeycomb discharge for the selective catalytic reduction of NO_x with hydrocarbon

( Nguyen Duc Ba ),( Nosir Matyakubov ),( Saud Shirjana ),목영선 한국공업화학회 2020 한국공업화학회 연구논문 초록집 Vol.2020 No.-

There are inhibited for a packed-bed reactor in plasma-catalyst for NO_x removal with a large flow rate, namely, pressure drop and scale-up. These issues can be solvent with a honeycomb plasma discharge, due to the honeycomb structure consisted of massive channels, the structure is the prevention of pressure drop and mechanical stability. Here, we will develop plasma discharge in a honeycomb monolith assisted in selectivity catalyst reduction of NO_x with hydrocarbon in a lowtemperature range below 300°C. The honeycomb discharge is carried out in a corona reactor, which comprised two perforated disks serving as electrodes and covered both monolith sides.

Removal of NOx by selective catalytic reduction coupled with plasma under temperature fluctuation condition

Duc Ba Nguyen,Van Toan Nguyen,허일정,목영선 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.72 No.-

The hydrocarbon selective catalytic reduction (HC-SCR) of nitrogen oxides (NOx) over Ag/α–Al2O3 withtemperaturefluctuation in the range of 150–350 C was investigated in a packed-bed dielectric barrierdischarge plasma reactor. The results revealed that the HC-SCR coupled with plasma maintained highNOx reduction efficiency around 74% regardless of the temperature variations in the range from 150 to350 C (10–40 C/min). In comparison, the NOx reduction efficiency of the HC-SCR-alone process wasvaried from 37.6 to 63.4%, depending on the reaction temperaturefluctuations. Consequently, the strongtemperature dependence of catalytic activity can be resolved by integrating plasma and catalysis.

Selective catalytic reduction of NO<SUB>x</SUB> with hydrocarbon in a honeycomb plasma reactor

Duc Ba Nguyen,Nosir Matyakubov,Shirjana Saud,Iljeong Heo(허일정),Young Sun Mok(목영선) 한국연소학회 2020 KOSCOSYMPOSIUM논문집 Vol.2020 No.9

Comparison of different applied voltage waveforms on CO2 reforming of CH4 in an atmospheric plasma system

Duc Ba Nguyen,이원규 한국화학공학회 2015 Korean Journal of Chemical Engineering Vol.32 No.1

Sinusoidal and pulse waveforms of applied voltage were employed for CO2 reforming of CH4 to syngas inan atmospheric dielectric barrier discharge reactor. The discharge power of a pulse waveform was higher than that ofsinusoidal waveform at the same applied voltage. The plasma reaction by a pulse waveform enhanced the conversion ofCO2 and CH4 and the selectivity of H2 and CO. It was confirmed that CO2 reforming of CH4 can be improved by theadaption of pulse-type power supply in a dielectric barrier discharge reactor immersed in an electrically insulating oilbath.

Effects of self-heating in a dielectric barrier discharge reactor on CHF₃ decomposition

Nguyen, Duc Ba,Lee, Won Gyu Elsevier 2016 CHEMICAL ENGINEERING JOURNAL -LAUSANNE- Vol.294 No.-

<P><B>Abstract</B></P> <P>A dielectric barrier discharge reactor, either exposed to atmosphere or immersed in an oil bath, was used to investigate the effects of self-heating on CHF<SUB>3</SUB> decomposition. In the ambient air condition, considerable amounts of energy were delivered to the plasma system in conjunction with high temperatures of the reactor wall, which were due to self-heating. In addition, a great deal of power was used for heating. A comparison of these two ambient conditions on plasma reactions demonstrated that the reactor in oil showed a stable discharge and yielded a greater energy efficiency, suggesting that the immersion of the plasma reactor in electrically insulating oil improved the performance of CHF<SUB>3</SUB> decomposition.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Immersing a reactor in oil bath prevents rapid heating during plasma reaction. </LI> <LI> Self-heating in plasma reactor gave some effects on degree of CHF<SUB>3</SUB> decomposition. </LI> <LI> Plasma reaction in oil ambient showed greater energy efficiency and stable operation. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Enhanced performance at an early state of hydrocarbon selective catalyst reduction of NOx by atmospheric pressure plasma

NGUYEN DUC BA,허일정,목영선 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.68 No.-

The improvement of NOx reduction by Ag/γ-Al2O3 with a hydrocarbon (n-C7H6) in the early state was investigated in a packed-bed dielectric barrier discharge plasma reactor. The results revealed that the combination of plasma with the catalyst enhanced NOx reduction efficiency at low operating temperatures, depending on the temperature and specific input energy. To sum up, the poor performance of the catalytic NOx reduction at low temperatures in the early stage before reaching thermochemical steady state can be greatly compensated for by using the atmospheric-pressure plasma generated in the catalyst bed.

Amount of Cassava Powder Fed as a Supplement Affects Feed Intake and Live Weight Gain in Laisind Cattle in Vietnam

Ba, Nguyen Xuan,Van, Nguyen Huu,Ngoan, Le Duc,Leddin, Clare M.,Doyle, Peter T. Asian Australasian Association of Animal Productio 2008 Animal Bioscience Vol.21 No.8

An experiment was conducted in Vietnam to test the hypothesis that supplementation with cassava powder up to 2% of live weight (LW)/d (DM basis) would linearly increase digestible organic matter intake and LW gain of Laisind cattle. There were five treatments: a basal diet of elephant grass fed at 1.25% of LW and rice straw fed ad libitum or this diet supplemented with cassava powder, containing 2% urea, at about 0.3, 0.7, 1.3 or 2.0% LW. The cattle fed cassava powder at about 2.0% LW did not consume all of the supplement, with actual intake similar to the 1.3% LW treatment. Organic matter, digestible organic matter and digestible energy intakes increased (p<0.001) curvilinearly with increased consumption of cassava powder. Rice straw intake declined curvilinearly with increasing intake of cassava powder (p<0.001), and there was a small linear decline (p = 0.01) in grass intake. The substitution rate of cassava powder for forage was between 0.5 and 0.7 kg DM reduction in forage intake per kg DM supplement consumed, with no difference between treatments. Apparent digestibility of organic matter increased (p<0.001) in a curvilinear manner, while digestibility of neutral detergent fibre declined (p<0.001) in a curvilinear manner with increased consumption of cassava powder. Live weight gain increased (p<0.01) linearly with increased consumption of supplement. It was concluded that the amount of cassava powder fed should be limited to between 0.7 and 1.0% LW.

Effects of Amount of Concentrate Supplement on Forage Intake, Diet Digestibility and Live Weight Gain in Yellow Cattle in Vietnam

Ba, Nguyen Xuan,Van Huu, Nguyen,Ngoan, Le Duc,Leddin, Clare M.,Doyle, Peter T. Asian Australasian Association of Animal Productio 2008 Animal Bioscience Vol.21 No.12

Two experiments were conducted in central Vietnam to test the hypothesis that supplementation with a concentrate, comprising rice bran (45% fresh basis), maize (49%), fish meal (3%), urea (2%) and salt (1%), up to 2% of live weight (LW)/d (dry matter (DM) basis) would linearly increase digestible organic matter intake and LW gain of yellow cattle. In both experiments, there were five treatments, namely a basal diet of fresh grass fed at 1.25% of LW (experiment 1, elephant grass, Pennisetum purpureum; experiment 2, native grass) and rice straw (Oryza sativa) fed ad libitum or this diet supplemented with concentrate at about 0.3, 0.7, 1.3 or 2.0% LW. There were 4 male growing cattle per treatment in experiment 1 and 3 in experiment 2. Diets were fed for 44 (experiment 1) or 49 (experiment 2) days, with feed intake recorded daily, LW measured about weekly and digestibility measurements made over 7 days commencing on day 24 (experiment 1) or day 10 (experiment 2). The elephant grass and native grass had neutral detergent fibre (NDF) concentrations of 82 and 73% DM, and nitrogen concentrations of 1.3 and 1.8% DM, respectively. The rice straw used had a NDF concentration of 79-84% DM and nitrogen concentration of 0.8% DM. The concentrate had NDF and nitrogen concentrations of 33 and 2.8% DM. In both experiments, DM intake increased (p<0.001) linearly as the amount of concentrate consumed increased. Rice straw intake declined (p<0.001) (experiment 1: 1.24 to 0.48 kg DM/d; experiment 2: 0.95 to 0.50 kg DM/d) as concentrate intake increased. Grass intake was not significantly affected by concentrate intake in either experiment. The lowest amount of concentrate supplement increased forage intake, after which substitution rate increased as the amount of concentrate consumed increased. However, substitution rates at the highest amount of concentrate consumed were modest at 0.3 to 0.5 kg DM reduction in forage intake/kg DM supplement consumed. In both experiments, digestible organic matter intake increased linearly (p<0.001) (experiment 1: 1.16 to 2.38 kg/d; experiment 2: 1.30 to 2.49 kg/d) as the amount of supplement consumed increased, as did LW gain (experiment 1: 0.15 to 0.81 kg/d; experiment 2: 0.15 to 0.77 kg/d). This was associated with significant (p<0.01) linear increases in organic matter intake and apparent organic matter digestibility. Neutral detergent fibre digestibility declined as concentrate intake increased, but the effect was not significant (p = 0.051) in experiment 2. These results are discussed in relation to existing literature and potential to improve the profitability of cattle fattening in central Vietnam.

Enhancement of energy efficiency of plasma-catalyst reduction of NO_x by intermittent dielectric barrier discharge plasma

( Nguyen Duc Ba ),목영선 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.1

Selective catalyst reduction of NO_x conjugated with atmospheric pressure plasma presented high archived NO_x removal at temperature fluctuation and low range of operation temperature (≤ 350 °C). However, to obtained high performance of NO_x removal, considerable input energy through plasma is required, suggesting a challenge of the plasma-catalyst technology from the viewpoint of practical application. The role of plasma during the NO_x process is partial oxidation of hydrocarbon or diesel fuel to hydrocarbon derivatives such as aldehyde compounds by energetic internal plasma. Therefore, continuous plasma process will be large energy consumption. Similar simulate batch process, we proposal the intermittent plasma, which can be provided energetic internal plasma but reduced absolute energy consumption by plasma. In this study, plasma-catalyst of NO_x removal will investigate with an intermittent plasma.