An electrochemical sensor based on manganese dioxide nanorodMnO2and Graphene oxide (GO) functionalized with 4-amino, 3-substituted 1H, 1, 2, 4 Triazole 5(4H) thion (FGO)/MnO2Nanocompositewas developed for voltammetric determination of Tetracycline (TET).The working electrode WE of SPCE was modified bya drop casting method. X-ray powder diffractometer (XRD), scanning electron microscopy (SEM) and FT-IR were employed to characterize the synthesized FGO/MnO2. The determination of TET at the modified electrode was studied by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) in the phosphate buffer solution (PBS).TET show sharp increase in the oxidation peaks in the pH 2.Voltammetric characteristics of TET (Epa, Ipa) were estimated. From effect of scan rate, the average surface coverage (Γ) of TET on the surface of SPCE modified with FGO/MnO2 nanocomposite, the electron transfer coefficient and electron transfer constant rate ket was obtained as 10.56×1014 molecule cm-2, 0.5, and 10.41 cm.s-1respectively. Under the optimal conditions, the peak current shows linear relationship with concentration of Tetracycline (TET) ranges 1–9 μM with the detection limit of 0.2μ M. The modified SPCE was successfully used to detect TET
An accurate and sensitive spectrophotometric method has been developed for the determination of carbamazepine (CRN.) in pure and dosage forms. The method is based on the oxidation of 2,4-dinitrophenylhydrazine (2,4-DNPHz) by potassium periodate than coupling with carbamazepine (CRN.) in alkaline medium to form a stable yellowish brown colored water-soluble dye with a maximum absorption at 485 nm. The variables that affect the completion of reaction have been carefully optimized. Beer’s law is obeyed over the concentration range of (4-50 μg.mL-1) with molar absorptivity of (6.7335×103 L.mol-1.cm1). The limit of detection was (0.1052 μg.mL-1) and Sandell’s sensitivity value was 0.0350 μg.cm-2.
... Show MoreA new, simple and sensitive spectrophotometric method was described for the determination of famotidine (FAM) as a pure material and in pharmaceutical formulation. This method was based on diazotization and coupling reaction between famotidine and diazotized solution of metochlopramide hydrochloride (DMPH) in the presence of phosphate buffer solution to give a compound of azo dye having orange color soluble in water with high absorptivity at a wave length of 478 nm. The data shows that FAM and DMPH combine in the molar ratio of 1:1 at PH 7.0 .The method obeys Beer's law over concentration range of 1-40 ?g.ml-1 of famotidine with a correlation coefficient of 0.9955 and a detection limit of 0.10 ?g.ml-1. The apparent molar absorptivity re
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Stainless steel (AISI 304) has good electrical and thermal conductivities, good corrosion resistance at ambient temperature, apart from these it is cheap and abundantly available; but has good mechanical properties such as hardness. To improve the hardness and corrosion resistance of stainless steel its surface can be modified by developing nanocomposite coatings applied on its surface. The main objective of this paper is to study effect of electroco-deposition method on microhardness and corrosion resistance of stainless steel, and to analyze effect of nanoparticles (Al2O3, ZrO2 , and SiC) on properties of composite coatings. I
... Show MoreThis study investigates the characterization and mechanical performance of Stone Mastic Asphalt (SMA) mixtures modified with two types of polymers: styrene–butadiene–styrene (SBS) and high-molecular-weight polyethylene (PE). Neat asphalt cement PG 64-16 was modified using a higher content of SBS and PE at concentrations of 6%, 7%, and 8% by weight of asphalt through the dry blending method to produce Highly Modified Asphalts (HiMA). The physical and rheological properties of the modified binders were evaluated using penetration, softening point, rotational viscosity, and dynamic shear rheometer (DSR) tests. Also, their phase compatibility and morphological changes were evaluated using the storage stability testing and scanning electron
... Show MoreThe effect of air injection device on the performance of airlift pump used for water pumping has been studied numerically and experimentally. An airlift pump of dimensions 42mm diameter and 2200 mm length with conventional and modified air injection device was considered. A modification on conventional injection device (normal air-jacket type) was carried out by changing injection angle from 90 (for conventional) to 22.5 (for modified). Continuity and Navier-Stokes equations in turbulent regime with an appropriate two-phase flow model (VOF) and turbulent model ( ) in two dimensions axisymmetry flow were formulated and solved by using the known package FLUENT version (14.5). The numerical and experimental investiga
... Show MoreThe cost of microalgae harvesting constitutes a heavy burden on the commercialization of biofuel production. The present study addressed this problem through economic and parametric comparison of electrochemical harvesting using a sacrificial electrode (aluminum) and a nonsacrificial electrode (graphite). The harvesting efficiency, power consumption, and operation cost were collected as objective variables as a function of applied current and initial pH of the solution. The results indicated that high harvesting efficiency obtained by using aluminum anode is achieved in short electrolysis time. That harvesting efficiency can be enhanced by increasing the applied current or the electrolysis time for both electrode materials, where 98
... Show MoreTwo modes of electrochemical harvesting for microalgae were investigated in the current work. A sacrificial anode (aluminum) was used to study the electrocoagulation-flotation process, and a nonsacrificial anode (graphite) was used to investigate the electroflotation process. The study inspected the effect of chloride ions concentration and the interelectrode distance on the performance of the electrochemical harvesting processes. The results demonstrated that both electrodes achieved maximum harvesting efficiency with a 2 g/L NaCl concentration. Interestingly, by increasing the NaCl concentration to 5 g/L, the harvesting efficiency reduced dramatically to its lowest value. Generally, the energy consumption decreased with increasing
... Show MoreThis study successfully synthesized high-performance photodetectors based on Ag-WO3 core–shell heterostructures using a simple and economical two-step pulsed laser ablation in water method and has investigated the electrical characteristics of the Ag@WO3 nanocomposite heterojunction. The Hall effect tests indicate that the synthesized Ag@WO3 exhibits n-type conduction with a Hall mobility of 1.25 × 103 cm2V-1S-1. Dark current–voltage properties indicated that the created heterojunctions displayed rectification capabilities, with the highest rectification factor of around 1.71 seen at a 5 V bias. A photodetector’s responsivity reveals the existence of two response peaks, which are situated in the ultraviolet and visible region. The ph
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