The purpose of this study to synthesize and characterize silver nanoparticles using phenolic compounds obtained from Camellia sinensis, to test the antibacterial properties of biosynthesized nanoparticles on the formation of biofilms in multidrug-resistant Pseudomonas aeruginosa. Ten isolates of P. aeruginosa were obtained from the Genetic Engineering and Biotechnology Institute laboratories of the University of Baghdad. By using the VITEK-2 system and culturing the isolates on cetrimide agar, the diagnosis was confirmed. Camellia sinensis silver nanoparticles (CAgNPs) were created using an extract of the plant's aqueous and methanolic leaves. Based on the results of the nanoparticle synthesis, spherical nanoparticles that may be single or mixed were included in both the aqueous and methanolic extracts of silver nanoparticles. By comparing their retention times to those of the reference compounds, the HPLC findings revealed that two phenolic compounds (gallic acid and caffeine) had been discovered. Utilising the disc diffusion technique, the antibacterial activity of (CAgNPs) was assessed. The results indicated that the methanolic (CAgNPs) extract was more effective than the aqueous (CAgNPs) extract at 375 and 750 ppm, giving the highest inhibition zone 17.67 and 21.33 mm, respectively, when compared to the aqueous (CAgNPs) extract, which produced inhibitory zones 13.00 and 16.33 mm, respectively. The MIC findings indicated that the methanolic CAgNPs extract was more effective than the aqueous CAgNPs extract; the MIC of the methanolic CAgNPs extract was 23.43 μg/ml in all P. aeruginosa isolates, except the isolates No. 9 and 10, which was 11.718 μg/ml. While in the aqueous extract, the MIC in all P. aeruginosa isolates was 187.5 μg/ml, with the exception of isolates No. 9 and 10, which was 93.75 μg/ml. Additionally, the methanolic CAgNPs extract entirely inhibited P. aeruginosa from building a biofilm when used at 23.43 μg/ml. However, at 46.87 μg/ml of the aqueous CAgNPs extract, totally reduced the biofilm forming activity on P. aeruginosa isolates
Thin filis have been prepared from the tin disulphide (SnS2 ), the pure and the doped with copper (SnS2:Cu) with a percentages (1,2,3,4)% by using ahemical spray pyrolysis techniqee on substrate of glass heated up to(603K)and sith thicknesses (0.7±0.02)?m ,after that the films were treated thermally with a low pressure (10-3mb) and at a temperature of (473K) for one hour. The influence of both doping with copper and the thermal treatment on some of the physical characteristics of the prepared films(structural and optical) was studied. The X-ray analysis showed that the prepared films were polycrystalline Hexagonal type. The optical study that included the absorptance and transmitance spectra in the weavelength range (300-900)nm
... Show MoreA mathematical model was proposed to study the microkinetics of esterification reaction of oleic acid with ethanol over prepared HY zeolite catalyst. The catalyst was prepared from Iraqi kaolin source and its properties were characterized by different techniques. The esterification was done under different temperature (40 to 70˚C) with 6:1 for molar ratio of ethanol to oleic acid and 5 % catalyst loading.
The microkinetics study was done over two period of time each period was examined individually to calculate the reaction rate constant and activation energy. The impact of the mass transfer resistance to the reactant was also investigated; two different studies have been accomplished to do this purpose.
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... Show MoreA mathematical model was proposed to study the microkinetics of esterification reaction of oleic acid with ethanol over prepared HY zeolite catalyst. The catalyst was prepared from Iraqi kaolin source and its properties were characterized by different techniques. The esterification was done under different temperature (40 to 70˚C) with 6:1 for molar ratio of ethanol to oleic acid and 5 % catalyst loading. The microkinetics study was done over two period of time each period was examined individually to calculate the reaction rate constant and activation energy. The impact of the mass transfer resistance to the reactant was also investigated; two different studies have been accomplished to do this purpose. The e
... Show MoreCadmium oxide thin films were prepared by D.C magnetron plasma sputtering using different voltages (700, 800, 900, 1000, 1100 and 1200) Volt. The Cadmium oxide structural properties using XRD analysis for just a voltage of 1200 volt at room temperature after annealing in different temperatures (523 and 623) K were studied .The results show that the films prepared at room temperature have some peaks belong to cadmium element along the directions (002), (100), (102) and (103) while the other peaks along the directions of (111), (200) and (222) belong to cadmium oxide. Annealed samples display only cadmium oxide peaks. Also, the spectroscopic properties of plasma diagnostic for CdO thin films were determined and the results show that the el
... Show MoreZinc oxide thin films were deposited by chemical spray pyrolysis onto glass substrates which are held at a temperature of 673 K. Some structural, electrical, optical and gas sensing properties of films were studied. The resistance of ZnO thin film exhibits a change of magnitude as the ambient gas is cycled from air to oxygen and nitrogen dioxide
Tin Selenide (SnSe) Nano crystalline thin films of thickness 400±20 nm were deposited on glass substrate by thermal evaporation technique at R.T under a vacuum of ∼ 2 × 10− 5 mbar to study the effect of annealing temperatures (as-deposited, 100, 150 and 200) °C on its structural, surface morphology and optical properties. The films structure was characterized using X-ray diffraction (XRD) which showed that all the films have polycrystalline in nature and orthorhombic structure, with the preferred orientation along the (111) plane. These films was synthesized of very fine crystallites size of (14.8-24.5) nm, the effect of annealing temperatures on the cell parameters, crystallite size and dislocation density were observed.
... Show MoreCdS and CdS:Sn thin films were successfully deposited on glass
substrates by spray pyrolysis method. The films were grown at
substrate temperatures 300 C°. The effects of Sn concentration on the
structural and optical properties were studied.
The XRD profiles showed that the films are polycrystalline with
hexagonal structure grown preferentially along the (002) axis. The
optical studies exhibit direct allowed transition. Energy band gap
vary from 3.2 to 2.7 eV.
Undoped and Iodine (I)–doped chrome oxide (Cr2O3)thin films have been prepared by chemical spray pyrolysis technique at substrate temperatures(773K) on glass substrate. Absorbance and transmittance spectra have been recorded as a function of wavelength in the range (340-800 nm) in order to study the optical properties such as reflectance, Energy gap of allowed direct transition, extinction coefficient refractive index, and dielectric constant in real and imagery parts all as a function of wavelength. It was found that all the investigated parameters affect by the doping ratios.
Spray pyrolysis technique (SPT) is employed to synthesize cadmium oxide nanostructure with 3% and 5% Cobalt concentrations. Films are deposited on a glass substrate at 350 ᵒC with 150 nm thickness. The XRD analysis revealed a polycrystalline nature with cubic structure and (111) preferred orientation. Structural parameters represent lattice spacing, crystallite size, lattice parameter and dislocation density. Homogeneous surfaces and regular distribution of atoms were showed by atomic force microscope (AFM) with 1.03 nm average roughness and 1.22 nm root mean square roughness. Optical properties illustrated a high transmittance more than 85% in the range of visible spectrum and decreased with Co concentration increasing. The absorption
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