This study thoroughly investigates the potential of niobium oxide (Nb2O5) thin films as UV-A photodetectors. The films were precisely fabricated using dc reactive magnetron sputtering on Si(100) and quartz substrates, maintaining a consistent power output of 50W while varying substrate temperatures. The dominant presence of hexagonal crystal structure Nb2O5 in the films was confirmed. An increased particle diameter at 150°C substrate temperature and a reduced Nb content at higher substrate temperatures were revealed. A distinct band gap with high UV sensitivity at 350 nm was determined. Remarkably, films sputtered using 50W displayed the highest photosensitivity at 514.89%. These outstanding optoelectronic properties highlight Nb2O5 thin films' potential for use in optoelectronic circuits and UV-A sensors, especially in the visible-blind range. These findings underscore Nb2O5 thin films' promise in advancing UV-A photodetector technology.
A 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
... Show MoreColloidal crystals (opals) made of close-packed polymethylmethacrylate (PMMA) were fabricated and grown by Template-Directed methods to obtain porous materials with well-ordered periodicity and interconnected pore systems to manufacture photonic crystals. Opals were made from aqueous suspensions of monodisperse PMMA spheres with diameters between 280 and 415 nm. SEM confirmed the PMMA spheres crystallized uniformly in a face-centered cubic (FCC) array. Optical properties of synthesized pores PMMA were characterized by UV–Visible spectroscopy. It shows that the colloidal crystals possess pseudo photonic band gaps in the visible region. A combination of Bragg’s law of diffraction and Snell’s law of refraction were used to calculate t
... Show MoreThree phenol-formaldehyde resins having pendant maleimides were prepared by poly condensation of N-(hydroxyphenyl) maleimides with formaldehyde under conditions similar to those in Novolac preparation. The prepared resins were modified by two methods, the first one includes esterification of phenolic hydroxyl groups in the prepared resins via their treatment with benzoyl, acryloyl, methacryloyl and cinnamoyl chlorides respectively in the presence of triethylamine, while the second modification includes free radical polymerization of vinylic bonds in the prepared resins to produce cross-linked thermally stable polymers.
Manganese-zinc ferrite MnxZn1-xFe2O4 (MnZnF) powder was prepared using the sol-gel method. The morphological, structural, and magnetic properties of MnZnF powder were studied using X-ray diffraction (XRD), atomic force microscopy (AFM), energy dispersive X-ray (EDX), field emission-scanning electron microscopes (FE-SEM), and vibrating sample magnetometers (VSM). The XRD results showed that the MnxZn1-xFe2O4 that was formed had a trigonal crystalline structure. AFM results showed that the average diameter of Manganese-Zinc Ferrite is 55.35 nm, indicating that the sample has a nanostructure dimension. The EDX spectrum revealed the presence of transition metals (Mn, Fe, Zn, and O) in Mang
... Show MoreThis work aims to investigate the inhibition of vitality of Streptococcus mutans, which is the causative agent of caries. A 632.8 nm He-Ne laser with the output power of 4.5mW was used in combination with toluidine blue O (TBO) at the concentration of 50μg/ml as a photosensitizer. Streptococcus mutans was isolated from 35 patients if carious teeth. Three isolates were chosen and exposed to different energy densities of He – Ne laser light 3.8, 11.7, 34.5 and 104.1 J/cm². After irradiation, substantial reduction was observed in the number of colony forming units (CFU)/ ml. The reduction in the number of CFU was increasing as the dose increased.
AgInSe2 (AIS) thin films solar cell involving of n-type AgInSe2 and Si of p-type substrate by using thermal evaporation method. The influence of annealing of the preparation AgInSe2 were considered to find the best properties of solar device. Thin film AIS have been deposited under the vacuum of 1.5*10-6 Torr with (400) nm thickness at R.T and annealing temperatures (473,573) K. Polycrystalline tetragonal structure for AIS thin films from XRD and increasing of surface roughness from AFM, energy gap values decreasing with increasing annealing temperatures, all films were negative type, I-V characteristics show increasing of efficiency with increasing of annealing temperatures.
Chemical spray pyrolysis technique was used at substrate temperature 250 ˚C with annealing temperature at 400 ˚C (for 1hour) to deposition tungsten oxide thin film with different doping concentration of Au nanoparticle (0, 10, 20, 30 and 40)% wt. on glass substrate with thickness about 100 nm. The structural, optical properties were investigated. The X-ray diffraction shows that the films at substrate temperature (250 ˚C) was amorphous while at annealing temperature have a polycrystalline structure with the preferred orientation of (200), all the samples have a hexagonal structure for WO3 and Au gold nanoparticles have a cubic structure. Atomic force microscopy (AFM) was used to characterize the morphology of the films. The optical pr
... Show MoreIn this work, an investigation for the dynamic analysis of thin composite cylindrical and spherical shells is presented. The analytical solution is based upon the higher order shear deformation theory of elastic shells from which the developed equations are derived to deal with orthotropic layers. This will cover the determination of the fundamental natural frequencies and mode shapes for simply supported composites cylindrical and spherical shells.
The analytical results obtained by using the derived equations were confirmed by the finite element technique using the well known Ansys package. The results have shown a good agreement with a maximum percentage of discrepancy, which gives a confidence o
... Show MorePVA:PEG/MnCl2 composites have been prepared by adding (MnCl2) to the mixture of the poly vinyl alcohol (PVA) and poly ethylene glycol (PEG) with different weight percentages (0, 2, 4, 6, 8 and 10) wt.% by using casting method. The type of charge carriers, concentration (nH) and Hall mobility (μH) have been estimated from Hall measurements and show that the films of all concentration have a negative Hall coefficient. In D.C measurement increase temperature leads to decrease the electrical resistance. The D.C conductivity of the composites increases with the increasing of the concentration of additive particles and temperature. The activation energy decreases for all composites with increasing the concentration of the additive particles.
... Show MoreBackground: techniques of image analysis have been used extensively to minimize interobserver variation of immunohistochemical scoring, yet; image acquisition procedures are often demanding, expensive and laborious. This study aims to assess the validity of image analysis to predict human observer’s score with a simplified image acquisition technique. Materials and methods: formalin fixed- paraffin embedded tissue sections for ameloblastomas and basal cell carcinomas were immunohistochemically stained with monoclonal antibodies to MMP-2 and MMP-9. The extent of antibody positivity was quantified using Imagej® based application on low power photomicrographs obtained with a conventional camera. Results of the software were employed
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