Sr Surface Enrichment in Solid Oxide Cells – Approaching the Limits of EDX Analysis by Multivariate Statistical Analysis and Simulations

In solid oxide cells, Sr segregation has been correlated with degradation. Yet, the atomistic mechanism remains unknown. Here we begin to localize the origin of Sr surface nucleation by combining force field based simulations, energy dispersive X-ray spectroscopy (EDX), and multi-variate statistical analysis. We find increased ion mobility in the complexion between yttria-stabilized zirconia and strontium-doped lanthanum manganite. Furthermore, we developed a robust and automated routine to detect localized nucleation seeds of Sr at the complexion surface. This hints at a mechanism originating at the complexion and requires in-depth studies at the atomistic level, where the developed routine can be beneficial for analyzing large hyperspectral EDX datasets

Corrosion Inhibition Using Harmal Leaf Extract as an Eco-Friendly Corrosion Inhibitor

Extract of natural plants is one of the most important metallic corrosion inhibitors. They are readily available, nontoxic, environmentally friendly, biodegradable, highly efficient, and renewable. The present project focuses on the corrosion inhibition effects of Peganum Harmala leaf extract. The equivalent circuit with two time constants with film and charge transfer components gave the best fitting of impedance data. Extraction of active species by sonication proved to be an effective new method to extract the inhibitors. High percent inhibition efficacy IE% of 98% for 283.4 ppm solutions was attained using impedance spectroscopy EIS measurements. The values of charge transfer Rct increases while the double layer capacitance Cdl values decrease with increasing Harmal extract concentration. This indicates the formation of protective film. The polarization curves show that the Harmal extract acts as a cathodic-type inhibitor. It is found that the adsorption of Harmal molecules onto the steel surface followed Langmuir isotherm. Fourier-transform infrared spectroscopy FTIR was used to determine the electron-rich functional groups in Harmal extract, which contribute to corrosion inhibition effect. Scanning electron microscopy SEM measurement of a steel surface clearly proves the anticorrosion effect of Harmal leaves

SYNTHESIS AND PRELIMINARY PHARMACOLOGICAL EVALUATION OF NEW NAPROXEN ANALOGUES HAVING 1, 2, 4-TRIAZOLE-3-THIOL

Objective: The objective of this search was to synthesize a new naproxen analogues having a 1,2,4-triazole-3-thiol heterocyclic ring, and preliminary pharmacological assessment of the anti-inflammatory activity of the synthesized compounds. Methods: The synthesis of naproxen analogues that having 1,2,4-triazole-3-thiol heterocyclic ring occur through esterification of naproxen, and then its reaction with hydrazine hydrate, and carbon disulfide, finally different aromatic aldehydes reacted with triazole derivatives of naproxen containing amino group to produce schiff bases.Results: In vivo acute anti-inflammatory activity of the synthesize compounds (Va-Vd) was evaluated in rats using egg-white induced edema model of inflammation in a dose equivalent to (50 mg/kg) of naproxen. All tested compounds were produced a significant reduction in paw edema with respect to the effect of propylene glycol 50% v/v (control group). Compound Vd produced superior anti-inflammatory activity compared to naproxen.Conclusion: The results obtained in this work give evidence about the valid synthesis of 1,2,4 triazole-3-thiol derivatives of naproxen, which reacted with different aldehydes to yield several schiff bases. The incorporation of benzaldehyde possess para-electron donating group (para-hydroxyl benzaldehyde) will increase the anti-inflammatory activity of naproxen

New spectrofluorometric application for the determination of ternary mixtures of drugs

A new spectrofluorometric method was developed for the determination of a ternary mixture of dexamethasone, dexchlorpheniramine maleate, and fluphenazine hydrochloride in dosage forms where the literature did not reveal any method for analysis of this mixture. The method was based on the use of the first and second derivatives of the ratio of the emission spectra with a zero-crossing technique. The ratio spectra were obtained by dividing the emission spectrum of the mixture by that of one of the components. The concentrations of the other components were then determined from their respective calibration graphs treated similarly. The method can resolve the spectral overlapping of the three components and was applied successfully for the determination of these drugs in synthetic mixtures and in commercial dosage forms.Peer reviewe

Derivative-ratio spectrophotometric method for the determination of ternary mixture of aspirin, paracetamol and salicylic acid

A derivative spectrophotometric method was developed for the assay of a ternary mixture of aspirin (ASP), paracetamol (PAR) and salicylic acid (SAL). The method is based on the use of the first and second derivatives of the ratio spectra and measurement at zero-crossing wavelengths. The ratio spectra were obtained by dividing the absorption spectrum of the mixture by that of one of the components. The concentration of the other components are then determined from their respective calibration curves treated similarly. The described method was applied for the determination of these combinations in synthetic mixtures and dosage forms. The results obtained were accurate and precise.Peer reviewe

Analysis of eprosartan-hydrochlorothiazide and irbesartan-hydrochlorothiazide binary mixtures by derivative spectrophotometry

Two simple and accurate spectrophotometric methods were presented for the determination of binary mixtures of each of Eprosartan and Irbesartan with Hydrochlorothiazide in dosage forms. Concerning the first mixture (Eprosartan/Hydrochlorothiazide mixture), Eprosartan was assayed by first derivative zero crossing technique, while Hydrochlorothiazide was determined by the second derivative zero crossing technique after extraction with ethyl acetate. On the other hand, for the second mixture (Irbesartan/Hydrochlorothiazide mixture), Irbesartan was determined by the first derivative zero crossing technique after extraction with chloroform, while Hydrochlorothiazide was determined by a specific colorimetric method using chromotropic acid. The aim of this work was to provide new analytical methods for both mixtures. These methods proved to be accurate and precise and were highly able to cope with the strong

Photodegradation of Congo Red by Modified P25-Titanium Dioxide with Cobalt-Carbon Supported on SiO₂ Matrix, DFT Studies of Chemical Reactivity

Congo red is a hazardous material in the environment. The present work describes the synthesis of TiO2/CoC@SiO2-bipy (1) and TiO2/CoC@SiO2-phen (2) nanocomposites for the photodegradation of azo-dye Congo red (CR) dye in aqueous solution, by combining pure TiO2 with CoC@SiO2-bipy (s1) and CoC@SiO2-phen (s2) nanoparticles. The prepared nanocomposites were evaluated in term of photocatalytic activity rates in aqueous solution using CR. The nanocomposites TiO2/CoC@SiO2-bipy (1) and TiO2/CoC@SiO2-phen (2) were prepared from TiO2 (75%) and CoC@SiO2-bipy (s1) or CoC@SiO2-phen (s2) (25%) (weight ratio). Ultra-sonication and milling were used to prepare the heterogeneous nano catalysts. The pH, initial dye concentration, and catalyst dosage appeared to have a significant impact on the photocatalytic degradation performance. Molecular oxygen and other active species played a significant role in the photocatalyst degradation of CR with sunlight energy (UV-index 5.0). The chemical reactions were accelerated depending upon electrophilicity (ω) and energy gap (Eg) of azo dye species CR-N=N, CR-N=NH and CR=N-NH species which were calculated by density function theory (DFT). It can be concluded that the rate of electron–hole recombination of the TiO2 catalyst, when adding CoC@SiO2-bipy (s1) or CoC@SiO2-phen (s2), not only enhances the degradation but also effectively removes toxic dye molecules and their by-products. The newly prepared TiO2/CoC@SiO2-bipy (1) nanocomposites showed increased photocatalytic efficiency at low catalyst dose and faster rate of degradation of Congo red compared to TiO2/CoC@SiO2-phen (2) and TiO2 catalysts. The novel catalysts (1) and (2) can be easily separated by centrifugation and filtration, from the reaction mixture compared to TiO2