An in situ modified Hummers method (without the use of any surfactants) has been used for the deposition of bismuth (Bi) nanoparticles onto the surface of reduced graphene oxide (RGO) sheets. The ...as-synthesized nanocomposites were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, transmission electron microscopy (TEM), thermogravimetry (TG) and differential scanning calorimetry (DSC). The morphology of the RGO/Bi nanocomposites provides a better choice as an electrode material for detection of heavy metal ions due to its better functional properties over the Bi film electrode. Trace analysis of heavy metal ions like Cd+2, Pb+2, Cu+2 and Zn+2 in water is carried out by stripping voltammetric analysis using RGO/Bi nanocomposite as an electrode material. The sensitivity and detection limit of the electrode were quantitatively estimated from the analysis. The three sigma detection limits at different deposition potential for Cd2+, Pb2+, Zn2+ and Cu2+ were obtained as 2.8, 0.55, 17 and 26μgL−1, respectively. Copper detection using Bi-film electrode was a major challenge, which has been resolved using the RGO/Bi nanocomposite electrode.
► RGO/Bi nanocomposite synthesized by modified Hummers method without surfactant. ► Reduction of GO and formation of Bi nanoparticles are accomplished simultaneously. ► Trace analysis of heavy ions with composite as electrode by stripping voltammetry. ► Detection limit for Cd2+, Pb2+, Zn2+, Cu2+ were 2.8, 0.55, 17 and 26μgL−1. ► Copper detection using Bi-film electrode resolved using these composites.
Display omitted
•A twostep relatively green method adopted to synthesize nanocomposite materials.•RGO/MnFe2O4/Polyaniline nanocomposite synthesized using the method.•Analytical method of detection ...with detection limit 0.015 μM developed.•Mechanism of interaction between the nano composite and nitrite explained.•Method has been applied in real sample analysis.
In the present investigation fibrous nanocomposite of reduced graphene oxide, manganese ferrite and polyaniline (RGO/MnFe2O4/Polyaniline) has been synthesized through a facile two-step greener approach by a solvent less thermolysis synthesis procedure. Long-chain amine is used as the solvent, reducing agent and surface functionalizing agent. Morphology and chemical functionalities of the nanocomposites are characterized using microscopic and spectroscopic measurements. Modified electrode is fabricated using the nanocomposite material and the electrochemical property of nitrite has been investigated using cyclic voltammetry measurements, an analytical method of detection of nitrite is developed using the modified electrode based on differential pulse voltammetry. Under optimum conditions, RGO/MnFe2O4/PANI fibrous nanocomposite based modified electrode have shown the linear dynamic range from 0.05 to 12000 μM with a detection limit of 0.015 μM for the detection of nitrite. The nanocomposite modified electrode showed good anti-interference ability against various common metal ions and some organic interfering agents. The nanocomposite modified electrodeis applied to determine the nitrite level in tap water. The indicative performance of the RGO/MnFe2O4/PANI fibrous nanocomposite modified electrode widens the scope of applications of RGO/MnFe2O4/PANI fibrous nanocomposite materials for on-site monitoring of nitrite.
Corrosion inhibition effect of
Justicia gendarussa extract (JGPE) on mild steel in 1
M HCl medium has been investigated by weight loss and electrochemical techniques. Inhibition efficiency of 93% was ...achieved with 150
ppm JGPE at 25
°C. The polarization studies showed that JGPE acts as mixed-type inhibitor. The Nyquist plots showed that on increasing JGPE concentration, increases charge transfer resistance and decreases double layer capacitance. JGPE obeys the Langmuir adsorption isotherm. AFM and ESCA confirmed the adsorption of JGPE on mild steel surface. Finally, JGPE inhibition efficiency was discussed in terms of adsorption and protective film formation.
A novel and low cost electrochemical method has been developed for the non-enzymatic detection of the hydrogen peroxide using cobalt ferrite (CoFe2O4), carbon nano tubes (CNTs) modified glassy carbon ...electro (GCE), and the sensor has been named as CoFe2O4/CNTs/GCE. The CoFe2O4/CNTs nanocomposite has been successfully synthesized through a facile one-step hydrothermal method. The crystal structure, morphology and composition of the nanocomposite are characterized by XRD, Raman, XPS, FE-SEM, and HR-TEM measuremnets. The particle size of ferrite nano composite is obtained as ~17 nm. Electrochemical properties of the CoFe2O4/CNTs/GCE are investigated using various electrochemical techniques such as; cyclic voltammetry, electrochemical impedance spectroscopy and square wave voltammetry. The constructed CoFe2O4/CNTs/GCE showed superior electrochemical activity towards H2O2 sensing compared with the CoFe2O4/GCE and bare GCE. The sensor produces a linear response in the range of 5–50 μM and the detection limit is obtained as 0.05 μM (S/N = 3) using chronoamperometry techniques and the square wave voltammetry technique generated the linear response in the range of 5–100 μM and the detection limit of 0.02 μM (S/N = 3). The developed sensor has shown suitable anti-interfering property with good stability towards the detection of H2O2. The CoFe2O4/CNTs modified electrode has been applied to determine H2O2 in the commercially available juice samples. The performance of the sensor is comparable or superior to several others commonly sensors used for the analysis of H2O2, which indicates its promising practical application.
Display omitted
•Cobalt ferrite and CNT nano composite has been synthesized using hydrothermal route.•Nano composite materials has been characterized with suitable redox states.•Materials shown excellent electrocatalytic activity for hydrogen peroxide oxidation.•Analytical method is developed with limit of detection 0.02 μM (S/N = 3).•Chronoamperometry could be obtained, suitable for continuous monitoring.
This article describes a wideband filter-less radio frequency (RF) power amplifier (PA) with in-band harmonics suppression using a polyphase network. The novel passive polyphase (three-way ...three-phase) network helps in suppressing both the second and third harmonics of the PA present within the operating band. The architecture uses three extended continuous class F (CCF) PAs, which are combined using the proposed polyphase network. The output power of the overall system varies between 41.7 and 42.4 dBm from 0.65 to 2.05 GHz. The second and third harmonic suppression levels are improved by 15-28 and 12-15 dB, respectively, when compared with that of the standalone PA.
This Article reports detailed extended X-ray absorption fine structure (EXAFS) analysis of spray pyrolysis synthesized TiO2 thin films to locate the position of nitrogen in N-doped phase pure ...(anatase) TiO2 and evaluate Ti–O bond distances and the coordination number of Ti. The thin films were synthesized at three different substrate temperatures viz. 400, 450, and 500 °C leading to concomitant occurrence of varying nitrogen concentration (N/Ti) of 0.282, 0.237, and 0.24, respectively. The coordination number extracted from the EXAFS fitting revealed that films synthesized at 450 °C are stoichiometric, whereas those synthesized at 400 and 500 °C are substoichiometric. The intensity of near edge peaks in XAS was employed to delineate the contribution from both symmetry of TiO6 polyhedra and particle size. The axial and equatorial Ti–O bond distances, corresponding to the different nitrogen concentrations, extracted from the EXAFS fitting, showed good agreement with those calculated from density functional theory calculations quoted in the literature. An increase in the axial and equatorial bond distances with respect to pristine TiO2 is observed and is attributed to the dominant effect of nitrogen occupancy in the interstitial position.
Pasteurella multocida causes acute septicemic and respiratory diseases, including haemorrhagic septicaemia, in cattle and buffalo with case fatality of 100%. In the present study, mice were infected ...with P. multocida (1.6 × 103 cfu, intraperitoneal) to evaluate host gene expression profile at early and late stages of infection using high throughput microarray transcriptome analyses. Several differentially expressed genes (DEGs) at both the time points were identified in P.multocida infected spleen, liver and lungs. Functional annotation of these DEGs showed enrichment of key pathways such as TLR, NF-κB, MAPK, TNF, JAK-STAT and NOD like receptor signaling pathways. Several DEGs overlapped across different KEGG pathways indicating a crosstalk between them. The predicted protein-protein interaction among these DEGs suggested, that the recognition of P. multocida LPS or outer membrane components by TLR4 and CD14, results in intracellular signaling via MyD88, IRAKs and/or TRAF6 leading to activation of NFκB and MAPK pathways and associated cytokines.
In present investigation, differential expression of transcriptome after classical swine fever (CSF) vaccination has been explored at the cellular level in crossbred and indigenous (desi) piglets. ...RNA Sequencing by Expectation-Maximization (RSEM) package was used to quantify gene expression from RNA Sequencing data, and differentially expressed genes (DEGs) were identified using EBSeq, DESeq2, and edgeR softwares. After analysis, 5222, 6037, and 6210 common DEGs were identified in indigenous post-vaccinated verses pre-vaccinated, crossbred post-vaccinated verses pre-vaccinated, and post-vaccinated crossbred verses indigenous pigs, respectively. Functional annotation of these DEGs showed enrichment of antigen processing-cross presentation, B cell receptor signaling, T cell receptor signaling, NF-κB signaling, and TNF signaling pathways. The interaction network among the immune genes included more number of genes with greater connectivity in vaccinated crossbred than the indigenous piglets. Higher expression of
IRF3
,
IL1β
,
TAP1
,
CSK
,
SLA2
,
SLADM
, and
NF-kB
in crossbred piglets in comparison to indigenous explains the better humoral response observed in crossbred piglets. Here, we predicted that the processed CSFV antigen through the T cell receptor signaling cascade triggers the B cell receptor-signaling pathway to finally activate MAPK kinase and NF-κB signaling pathways in B cell. This activation results in expression of genes/transcription factors that lead to B cell ontogeny, auto immunity and immune response through antibody production. Further, immunologically important genes were validated by qRT-PCR.
► Optimization of color removal and COD removal done by response surface approach. ► The experiments were designed using Box–Behnken spherical design. ► Two quadratic polynomial models were developed ...for the responses. ► Single point numerical optimization was done considering three constraints. ► Validation by performing the experiment under optimized conditions.
Photocatalytic degradation of methyl blue (MYB) was studied using Ag+ doped TiO2 under UV irradiation in a batch reactor. Catalytic dose, initial concentration of dye and pH of the reaction mixture were found to influence the degradation process most. The degradation was found to be effective in the range catalytic dose (0.5–1.5g/L), initial dye concentration (25–100ppm) and pH of reaction mixture (5–9). Using the three factors three levels Box–Behnken design of experiment technique 15 sets of experiments were designed considering the effective ranges of the influential parameters. The results of the experiments were fitted to two quadratic polynomial models developed using response surface methodology (RSM), representing functional relationship between the decolorization and mineralization of MYB and the experimental parameters. Design Expert software version 8.0.6.1 was used to optimize the effects of the experimental parameters on the responses. The optimum values of the parameters were dose of Ag+ doped TiO2 0.99g/L, initial concentration of MYB 57.68ppm and pH of reaction mixture 7.76. Under the optimal condition the predicted decolorization and mineralization rate of MYB were 95.97% and 80.33%, respectively. Regression analysis with R2 values >0.99 showed goodness of fit of the experimental results with predicted values.
We demonstrate that the pulsed-time structure and high-peak ion intensity provided by the laser-ablation process can be directly combined with the high resolution, high efficiency, and low background ...offered by collinear resonance ionization spectroscopy. This simple, versatile, and powerful method offers new and unique opportunities for high-precision studies of atomic and molecular structures, impacting fundamental and applied physics research. We show that even for ion beams possessing a relatively large energy spread, high-resolution hyperfine-structure measurements can be achieved by correcting the observed line shapes with the time-of-flight information of the resonantly ionized ions. This approach offers exceptional advantages for performing precision measurements on beams with large energy spreads and allows measurements of atomic parameters of previously inaccessible electronic states. The potential of this experimental method in multidisciplinary research is illustrated by performing, for the first time, hyperfine-structure measurements of selected states in the naturally occurring isotopes of indium,In113,115. Ab initio atomic-physics calculations have been performed to highlight the importance of our findings in the development of state-of-the-art atomic many-body methods, nuclear structure, and fundamental-physics studies.
PDF
