Facile single-step synthesis of Cu-rGO nanocomposite through simultaneous reduction process and its peroxidase mimic activity

2021 ◽  
Vol 95 ◽  
pp. 388-396
Author(s):  
Kyungjun Kim ◽  
Kiran N. Chaudhari ◽  
Shinik Kim ◽  
Yeonho Kim ◽  
Kuan Soo Shin
Metals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 58
Author(s):  
Víctor Hugo Gutiérrez Pérez ◽  
Juan Daniel Osorio Hernández ◽  
Ricardo Gerardo Sánchez Alvarado ◽  
Alejandro Cruz Ramírez ◽  
Seydy Lizbeth Olvera Vázquez ◽  
...  

Lead was recovered through a direct smelting reduction route from a lead concentrate by using mixtures of Na2CO3 and SiC to 1000 °C. The lead concentrate was obtained from the mining State of Zacatecas, México by traditional mineral processing and froth flotation. The experimental trials showed that 86 wt.% of lead with a purity up to 97% can be recovered from the lead concentrate by a single step reduction process when 40 wt.% Na2CO3 and 0.4 g SiC were used in the initial charge. The process was modeled in the thermodynamic software FactSage 7.3 to evaluate the effect of adding different amounts of Na2CO3 on the lead recovery rates while holding constant the SiC amount and temperature. The stability phase diagram obtained showed that an addition of 34 wt.% Na2CO3 was enough to reach the highest lead recovery. It was observed that the interaction of Na2CO3 and SiC at a high temperature promotes the formation of C and Na2O, and SiO2, respectively, where the Na2O partially bonds with silica and sulfur forming Na2S and sodium silicates which may decrease the SO2 emissions and increase the weather degradation of the slag. The PbS was mainly reduced by the produced C and CO formed by the interaction between Na2CO3 and SiC at 1000 °C. The predicted results reasonably match with those obtained experimentally in the lead recovery rates and compounds formation.


2019 ◽  
Vol 25 (4) ◽  
pp. 579-587 ◽  
Author(s):  
Jongte Lalmalsawmi ◽  
Zirlianngura ◽  
Diwakar Tiwari ◽  
Seung-Mok Lee

Novel silane grafted bentonite was obtained using the natural bentonite as precursor material. The material which is termed as nanocomposite was characterized by the Fourier Transform Infra-red (FT-IR) and X-ray diffraction (XRD) methods. The surface imaging and elemental mapping was performed using Scanning Electron Microscopic (SEM/EDX) technique. The electroanalytical studies were performed using the nanocomposite electrode. The electroactive surface area of nanocomposite electrode was significantly increased than the pristine bentonite or bare carbon paste based working electrode. The impedance spectroscopic studies were conducted to simulate the equivalent circuit and Nyquist plots were drawn for the carbon paste electrode and nanocomposite electrodes. A single step oxidation/reduction process occurred for As(III) having ΔE value 0.36 V at pH 2.0. The anodic stripping voltammetry was performed for concentration dependence studies of As(III) (0.5 to 20.0 μg/L) and reasonably a good linear relationship was obtained. The detection limit of the As(III) detection was calculated as 0.00360±0.00002 μg/L having with observed relative standard deviations (RSD) less than 4%. The presence of several cations and anions has not affected the detection of As(III) however, the presence of Cu(II) and Mn(II) affected the detection of As(III). The selectivity of As(III) was achieved using the Tlawng river water sample spiked with As(III).


2017 ◽  
Vol 19 (2) ◽  
pp. 23
Author(s):  
Emperatriz Farje Ocampo ◽  
Fidel Vargas Escalante ◽  
Croswel Aguilar Quiroz

Se estudió el proceso de obtención de energía eléctrica por la descomposición del almidón con HCl (0.0762N) en una sola etapa. Se propone realizar las reacciones de hidrólisis y óxido-reducción en forma casi simultánea. Las variables de estudio son: temperatura (14-36ºC), relación de Almidón (g)/Agua (mL) (1/80- 1/160), relación concentración de HCl (1x10-3,2.5x10-3,4.8x10-3 y 9x10-3 N) y el tiempo de vida útil. Se utilizaron celdas voltaicas conteniendo agua y almidón pero separadas por una membrana de acetato de celulosa. Se adicionó HCl solo a una semicelda. Se completa el circuito con electrodos de grafito y un multitester para medir el voltaje. Los resultados obtenidos muestran que los mayores voltajes se obtienen cuando la concentración del HCl es de 9x10-3 N, para menores concentraciones el sistema es inestable y se obtienen menores voltajes. Altas concentraciones de HCl producen el rompimiento de la cadena, y por lo tanto, habría mayor cantidad de moléculas reaccionando para la oxidación-reducción y el sistema se estabiliza rápidamente para la producción de energía. A temperaturas de 28 a 30°C se generaron los mayores voltajes. Así mismo, la relación Agua (ml)/Almidón (g) de 150/1 generó mayores voltajes, posiblemente porque favorece la disociación del HCl. Así, habría una mayor concentración de protones que pasan a través de la membrana a la otra semicelda, y genera reacciones de óxido- reducción que se traduce en mayor voltaje en las celdas. Bajo las condiciones estudiadas las celdas tienen un tiempo de vida útil de 338 horas (14 días), que es el mismo número de días que Jacacody reporto en su trabajo acerca de la lintnerizacion de gránulos de almidón de cereales. El mayor voltaje registrado al final de suvidaútiles214.0mV. Palabras clave.-Bioceldas, Hidrolisis acida, Reacciones de óxido–reducción. ABSTRACTThe processis is studies for obtaining electrical energy from the decomposition of starch using HCl (0.0762N) in a single step it is proposed to make the reactions of hydrolysis and oxidation- reduction almost simultaneously. The study variables are: temperature (14-36 ° C), ratio of starch (g) / water (mL) (1/80- 1/160), relative concentration of HCl (1x10-3, 2.5x10-3, 4.8x10-3 and 9x10-3 N) and lifetime. Voltaic cells were used containing water and starch, separated by a membrane of cellulose acetate. HCl was added only to half a cell it. [Graphite electrodes and a voltage measuring multitester completes the circuit voltages are obtained when the concentration of HCl is 9x10-3N, lower concentrations make the system unstable with very low voltages. High concentrations of HCl produce the breaking of the starch chain, therefore more molecules react for oxidation-reduction process stabilizing the system for energy production. At temperatures of 28 to 30 ° C were generated higher voltages. Likewise, the ratio Water (ml) / Starch (g) of 150/1 led to higher voltages, possibly because they favor the dissociation of HCl. Thus, it would have a higher concentration of protons to pass through the membrane to the other half cell, and generates oxidation-reduction reactions which results in higher voltage in the cells. Under the studied conditions the cells have a lifespan of 338 hours (14 days), which is the same number of days reported in their work Jacacody about lintnerization of cereal starch granules. The highest voltage recorded at the end of their useful life is 214.0 mV]. Keywords.- Bio cells, Acid hydrolysis, Oxido-reduction reactions.


2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Jacinto Sá

AbstractWe report an in situ time-resolved high-energy resolution off-resonant spectroscopy (HEROS) study with unprecedented 100 ms time resolution revealing the unoccupied electronic states of platinum during regenerative oxidation and reduction cycles. The study depicted a slowed oxidation step in comparison with reduction. The oxidation cycle is composed of two characteristic stages, namely adsorption of dissociated oxygen followed by partial oxidation of Pt subsurface. Besides improved temporal resolution of the experiment, the detected reduction process of platinum showed no intermediate features and was completed in a single step within a few seconds.


2015 ◽  
Vol 5 (1) ◽  
pp. 22-30 ◽  
Author(s):  
Marek Wojnicki ◽  
Magdalena Luty-Błocho ◽  
Krzysztof Mech ◽  
Justyna Grzonka ◽  
Krzysztof Fitzner ◽  
...  

Pharmaceutics ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 575
Author(s):  
Dasom Kim ◽  
Reeju Amatya ◽  
Seungmi Hwang ◽  
Sumi Lee ◽  
Kyoung Ah Min ◽  
...  

Silver nanoparticles (NPs) have attracted a considerable interest in the field of cancer research due to their potential utility in cancer therapy. In the present study, we developed bovine serum albumin (BSA)-coated silver NPs (BSA-Silver NPs) and characterized in vitro multimodal therapeutic activities of NPs for the treatment of skin cancer. BSA-Silver NPs were synthesized by a single-step reduction process, and the successful preparation was verified through a list of physical characterizations, including transmission electron microscopy (TEM), ultraviolet-visible (UV–VIS) light spectroscopy, dynamic light scattering (DLS), and Fourier transform infrared (FT-IR) spectroscopy. The synthesized BSA-Silver NPs showed marked cytocidal effects on B16F10 melanoma cells, which was likely caused by oxidative stress. BSA-Silver NPs also elicited significant anti-angiogenic effects on HUVEC (human umbilical vein endothelial cell) by inhibiting their proliferation, migration, and tube formation. Moreover, BSA-Silver NPs showed a considerable light-to-heat conversion ability, suggesting their utility as photothermal agents. Overall, our findings suggest that BSA-Silver NPs may be promising candidates for the multimodal therapy of skin cancer.


RSC Advances ◽  
2015 ◽  
Vol 5 (102) ◽  
pp. 84093-84103 ◽  
Author(s):  
Rachel E. Priestley ◽  
Alexander Mansfield ◽  
Joshua Bye ◽  
Kevin Deplanche ◽  
Ana B. Jorge ◽  
...  

Schematic showing the possible electronic interactions betweenE. coli, Pd(ii) and GO during the simultaneous reduction process leading to enhanced crystallinity in bacterial biomass.


Electronics ◽  
2022 ◽  
Vol 11 (2) ◽  
pp. 170
Author(s):  
Yasser Albagory ◽  
Fahad Alraddady

Antenna arrays have become an essential part of most wireless communications systems. In this paper, the unwanted sidelobes in the symmetric linear array power pattern are reduced efficiently by utilizing a faster simultaneous sidelobes processing algorithm, which generates nulling sub-beams that are adapted to control and maintain steep convergence toward lower sidelobe levels. The proposed algorithm is performed using adaptive damping and heuristic factors which result in learning curve perturbations during the first few loops of the reduction process and is followed by a very steep convergence profile towards deep sidelobe levels. The numerical results show that, using the proposed adaptive sidelobes simultaneous reduction algorithm, a maximum sidelobe level of −50 dB can be achieved after only 10 iteration loops (especially for very large antenna arrays formed by 256 elements, wherein the processing time is reduced to approximately 25% of that required by the conventional fixed damping factor case). On the other hand, the generated array weights can be applied to practical linear antenna arrays under mutual coupling effects, which have shown very similar results to the radiation pattern of the isotropic antenna elements with very deep sidelobe levels and the same beamwidth.


2005 ◽  
Vol 173 (4S) ◽  
pp. 240-240
Author(s):  
Premal J. Desai ◽  
David A. Hadley ◽  
Lincoln J. Maynes ◽  
D. Duane Baldwin

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