Porous silicon (PSi) is a nanostructured material possessing a huge surface area per unit volume. In consequence, the adsorption and diffusion of oxygen in PSi are particularly important phenomena and frequently cause significant changes in its properties. In this paper, we study the thermal oxidation of p+-type free-standing PSi fabricated by anodic electrochemical etching. These free-standing...

Textile industries consume large volumes of water for dye processing, leading to undesirable toxic dyes in water bodies. Dyestuffs are harmful to human health and aquatic life, and such illnesses as cholera, dysentery, hepatitis A, and hinder the photosynthetic activity of aquatic plants. To overcome this environmental problem, the advanced oxidation process is a promising technique to minerali...

A kinetic and spectroscopic characterization of the ferryl intermediate (APO-II) from APO, the heme-thiolate peroxygenase from Agrocybe aegerita, is described. APO-II was generated by reaction of the ferric enzyme with metachloroperoxybenzoic acid in the presence of nitroxyl radicals and detected with the use of rapid-mixing stopped-flow UV-visible (UV-vis) spectroscopy. The nitroxyl radicals s...

Objective(s): Pyocyanin is a blue-greenish redox-active pigment, produced by Pseudomonas aeruginosa, with a wide range of biological and biotechnological applications. Pyocyanin biosynthesis is regulated by the quorum-sensing (QS) system in which the expression of QS genes and QS-controlled virulence genes may be affected by serum as a complex medium. In the current study, effects of adult bovi...

Ultraviolet UV absorbance measurements are subject to significant error using a standard spectrophotometer when particles or aggregates that scatter light are present. True UV absorbance for highly turbid waters should be measured using integrating sphere IS spectrophotometry that allows the collection of reflected and transmitted radiation simultaneously. This is especially important when the ...

New methods for the production of colloidal Ga nanoparticles (GaNPs) are introduced based on the evaporation of gallium on expendable aluminum zinc oxide (AZO) layer. The nanoparticles can be prepared in aqueous or organic solvents such as tetrahydrofuran in order to be used in different sensing applications. The particles had a quasi mono-modal distribution with diameters ranging from 10 nm to...

Validation of UV-visible aerosol optical thickness retrieved from spectroradiometer measurements C. Brogniez, V. Buchard, and F. Auriol LOA/CNRS, Université des Sciences et Technologies de Lille, France Received: 18 January 2008 – Accepted: 21 January 2008 – Published: 26 February 2008 Correspondence to: C. Brogniez ([email protected]) Published by Copernicus Publications on behal...

Abstract The leaves of Phaleria macrocarpa (Scheff.) Boerl is traditionally used to treat various diseases. contain flavonoids, alkaloids, tannins, glycosides, saponins, and steroids. This study aimed identify the simplicia extract, as well ethanol extract’s antioxidant activity, from leaves. extract was quantitatively tested using UV-Visible Spectrophotometry for its total phenol flavonoid con...

In this research, undoped and doped (Fe, Ce, and Ag) antibacterial coatings of nanostructured TiO2 films were prepared by a sol-gel dip coating method. Doped and undoped TiO2 films were excited with ultraviolet (UV) radiation to improve their photo catalytic activity. The antibacterial activity against Staphylococcus Aureus bacteria was studied using an antibacterial–drop test and colony count ...

In this study, biosynthesis and in vitro phytochemical composition, antibacterial antioxidant activities of silver nanoparticles were investigated by using aqueous leaf, flower root extracts Primula vulgaris (P. subsp. vulgaris). The synthesized (AgNPs) confirmed color conversion ultraviolet-visible (UV-visible) spectrophotometry. appearance a dark brown UV absorption spectrum range at 440 nm t...