Full potential linear augmented plane wave calculations of Electronic and Optical properties in ZnO

 In this work we present self-consistent calculations for the electronic and optical properties of Zinc oxide. A theoretical investigation of the electronic properties (band structure, density of charge and contour map) and optical properties (refractive index, absorption coefficient, dielectric constants and reflectivity) of Zinc oxide semiconductor ZnO. A full-potential linearized augmented plane-wave (FPLAPW) method was used within the density functional theory (DFT) along with the generalized gradient approximation (GGA96) exchange correlation potential. The results are compared with the experimental data available and some other theoretical work. We found that the GGA approximation yields only a small improvement to the band gap, however, if we allow for a rigid shift of the band structure, the so-called scissors operator, the optical properties are excellently reproduced

Study on anisotropies and momentum densities in AlN, GaN and InN by positron annihilation

The independent particle model (IPM) coupled with empirical pseudopotential method (EPM) was used to compute the thermalized positron charge densities in specific family of binary tetrahedrally coordinated crystals of formula ANB8-N. Initial results show a clear asymmetrical positron charge distribution relative to the bond center. It is observed that the positron density is maximum in the open interstices and is excluded not only, from the ion cores but also to a considerable degree from the valence bonds. Electron-positron momentum densities are calculated for the (001,110) planes. The results are used to analyze the positron effects in AlN, GaN and InN compounds. Our computational technique provides the theoretical means of interpreting the k-space densities obtained experimentally using the twodimensional angular correlation of annihilation radiation (2D-ACAR)

Forced degradation study of quinapril by UPLC-DAD and UPLC/MS/MS: Identification of by-products and development of degradation kinetics.

International audienceQuinapril undergoes a significant degradation in the solid state, specially in the presence of humidity, temperature and pharmaceutical excipients. Since dissolution increases the degradation, hydrolytic reactions are among the most common processes involved in drug degradation. Improving the knowledge regarding drug stability, particularly concerning the critical factors that can influence the stability of the active substance in solutions, such as the temperature, the pH and the concentration of catalytic species usually acids or bases are essential for pharmaceutical use. The aim of this study was therefore to develop a new chromatographic method for rapidly and accurately assessing the chemical stability of quinapril and to study the mechanism of quinapril degradation in acidic, neutral and alkaline media at 80°C according to the ICH guidelines. Ultra High Performance Liquid Chromatography (UPLC) coupled with electrospray ionization tandem mass spectrometry and/or diode array detector was used for the rapid and simultaneous analysis of quinapril and its by-products. Separation was achieved using a BEH C18 column and a mixture of acetonitrile-ammonium hydrogencarbonate buffer (pH 8.2; 10 mM) (65:35, v/v) at a flow rate of 0.4 mL/min as a mobile phase. This method allowed drug byproducts profiling, identification, structure elucidation and quantitative determination under stress conditions. The developed method also provides the determination of the kinetic rate constants for the degradation of quinapril and the formation of its major by-products. A complete model including degradation pathway observed under all tested conditions was proposed according to the kinetic study and the structure elucidation of by-products

Combined electrochemical and biological treatment for pesticide degradation - Application to phosmet

International audienceThe aim of this study was to determine the feasibility of coupling an electrochemical process with a biological treatment in order to degrade phosmet, an organophosphorous pesticide. The absence of biodegradability of phosmet by Pseudomonas fluorescens and activated sludge was verified in our operational conditions. So, a conventional biological treatment is not appropriate for phosmet polluted effluents. Electrochemical behavior of phosmet was studied by cyclic voltammetry and the feasibility of an electrochemical pretreatment was thus demonstrated. Preliminary results with activated sludge showed a diminution of 26% for COD (chemical oxygen demand) measured when the electrolyzed solution was used as the sole carbon and nitrogen sources. When glucose and ammonium were added as supplementary carbon and nitrogen sources, the COD diminution reached 34% after 79 h of culture. This study demonstrates the feasibility of an electrochemical pre-treatment prior to biotreatment

In Vitro Anticoccidial Activity of Olive Pulp (Olea europaea L. var. Chemlal) Extract Against Eimeria Oocysts in Broiler Chickens

Aim: The objective of the present study was to investigate in vitro anticoccidial effect of olive pulp (Olea europaea L var. Chemlal) extract on the destruction of Eimeria spp. oocysts isolated from infected chickens naturally. Materials and methods: The olive pulp (OP) powder was stirred manually in aqueous ethanol in preparation for extraction using the microwave-assisted extraction system. The identification of the phenolic compounds was obtained by ultra-high-performance liquid chromatography–mass spectrometry with electrospray ionisation (HPLC–ESI–MS). The treatment of Eimeria oocyst with OP extract and standard compounds (quercetin and oleuropein) leads to their lysis as shown by the release of substances absorbing at 273 nm. Results: Our results showed that the maximum number of reduced oocysts was recorded after 8 h of incubation of optimum OP extract, quercetin and oleuropein for different periods of time. Also, the number of Eimeria oocysts decreased considerably with increase concentrations after adding the optimum of OP extract in concentration ranging from 0.023 to 0.371 mg/ml. Positive correlation between the optimum OP extract concentrations and the number of Eimeria oocysts reduced was R2 = 0.959. From this in vitro experiment, it can be concluded that the OP extract possesses an anti-Eimeria spp activity. Conclusion: To our knowledge, this is the first time that quercetin and oleuropein were tested to evaluate their anticoccidial activity. The findings of this study showed that phenolic compound of OP extract tested separately possesses anti-Eimeria spp. effect. Further studies should be carried out to test its in vivo efficacy of the OP bioactive compounds in broiler chickens

Relevance of Lipid-Based Products in the Management of Dry Eye Disease

Components of the ocular surface synergistically contribute to maintaining and protecting a smooth refractive layer to facilitate the optimal transmission of light. At the air-water interface, the tear film lipid layer (TFLL), a mixture of lipids and proteins, plays a key role in tear surface tension and is important for the physiological hydration of the ocular surface and for ocular homeostasis. Alterations in tear fluid rheology, differences in lipid composition, or downregulation of specific tear proteins are found in most types of ocular surface disease, including dry eye disease (DED). Artificial tears have long been a first line of treatment in DED and aim to replace or supplement tears. More recently, lipid-containing eye drops have been developed to more closely mimic the combination of aqueous and lipid layers of the TFLL. Over the last 2 decades, our understanding of the nature and importance of lipids in the tear film in health and disease has increased substantially. The aim of this article is to provide a brief overview of our current understanding of tear film properties and review the effectiveness of lipid-based products in the treatment of DED. Liposome lid sprays, emulsion eye drops, and other lipid-containing formulations are discussed.Peer reviewe

Seasonal variation of plasma testosterone levels in Algerian male Arabia goats

The aim of the present work was to evaluate the general monthly averages of the testosterone hormone and the influence of  season and photoperiod on plasma testosterone levels in Arabia bucks of Algeria. Testosterone concentrations were determined throughout one year in blood samples collected every fortnight of the month from nine males of Arabia goat breeds, fed a constant diet, maintained without interactions with female goat. Plasma testosterone level was measured by radioimmunoassay. Analyses performed show that the monthly averages of the testosterone hormone vary during the year; higher levels were recorded during August (T=8.57±6.72, P=0.00***) however, bucks displayed the same change tendency during the same period (P=0.79). Plasma testosterone concentrations vary significantly between seasons (P=0.00***) being higher during autumn (6.15±3.81ng/ml) compared with spring (0.90 ± 1.27ng/ml) when hormone synthesis reaches its lowest levels. In conclusion, Arabia bucks of Algeria displayed a clear seasonality of plasma testosterone concentration with very low levels in winter and spring (from January to May) and high levels in summer and autumn (from July to November).Keywords: Arabia bucks, testosterone, season, photoperiod

Exploring the Influence of Sr Concentration on the Structural and Catalytic Properties of CuO/SrSO4 Nanocomposites for Organic Dye Degradation

Pure CuO and CuO/SrSO4 nanocomposites were synthesized via the hydrothermal method to explore their catalytic efficacy in degrading methylene blue (MB). CuSO4\ub75H2O, NaOH, and SrCl2\ub76H2O were used as primary reagents. XRD characterization unveiled the monoclinic structure (C2/c) of pure CuO NPs, exhibiting well-defined crystallinity with crystallite sizes ranging from 9.64 to 26.08 nm. Notably, samples with Sr concentrations exceeding 2wt% exhibited a secondary SrSO4 phase with an orthorhombic structure (Pnma). Infrared and Raman spectroscopy confirmed Cu-O, S-O, and Sr-O bond vibrations, validating CuO and SrSO4 synthesis. SEM micrographs depicted irregular platelet-like morphology with a surface area of up to 0.061 μm2 and nanometric thickness for pure CuO NPs, while this morphology varied for CuO/SrSO4 nanocomposites. BET analysis revealed a relatively large specific surface area (9.04 to 15.12 m2 /g), potentially advantageous for catalytic activity. Catalytic degradation of MB in aqueous solution by pure CuO NPs exhibited limited efficiency (19.77% in 60 min), markedly enhanced to 100% in 40 min with the addition of H2O2. Despite H2O2 presence, CuO/SrSO4 nanocomposites showed lower MB degradation efficiency due to sulfate SO4 2- ion poisoning. Monitoring the formation of SrSO4 phase is a synthesis strategy to adjust the poisoning effect by sulfate ions. The sample with a Sr concentration of 6 wt% demonstrated the highest degradation rate (83.78% in 40 min), attributed to its larger specific surface area. Furthermore, synthesized materials displayed satisfactory catalytic stability upon recycling for MB degradation

Investigating the Efficacy of Oily Water Treatment at a De-Oiling Facility in the Northern Industrial Center of CINA - Hassi Messaoud: A Statistical Physics Assessment

Environmental protection is becoming a primary objective when choosing processes andtechnologies for treating oily waters resulting from hydrocarbon production. The focus of treatingoily waters is to eliminate contaminants from effluents before discharging them into the receivingenvironment while adhering to discharge standards. Our work aims to analyze the treatment processfor oily waters in the API unit of the North Industrial Center (CINA), which involves a physical–chemical treatment using activated silica and Kurifix. The study aims to improve the treatmentprocess used for oily water treatment to ensure water conservation for reuse. To enhance the CINAHMDoily water treatment process, we created coagulants with different doses (C1–C6) using sodiumsilicate, activated silicate (sodium silicate + sulfuric acid), distilled water, Kurifix, and an oxygenscavenger while measuring pH, HC (hydrocarbon), and SS (suspended solids) levels. Coagulationand flocculation processes were used to remove suspended solids and hydrocarbons from the water.The results show that the coagulant used reduces suspended matter and hydrocarbon content andincreases pH. The best treatment is achieved with a coagulant prepared with distilled water, 5%sodium silicate, and 2% sulfuric acid. The optimal dose of coagulant is 16 ppm. Automatic dosingprovides better efficiency than manual dosing. The study recommends continuous verification ofchemical preparation and injection, periodic cleaning of settling tanks, and monitoring of oily waterentering the station