Cobalt substituted nickel copper ferrite samples with general formula Ni0.95-xCoxCu0.05Fe2O4, where (x= 0.00, 0.01, 0.02, 0.03, 0.04 and 0.05) were prepared by solid-state reactions method at 1373 K for 4h. The samples prepared were examined by X-ray diffraction (XRD(, atomic force microscope (AFM), Fourier transform infra-red spectroscopy (FTIR) and Vickers hardness. X-ray diffraction patterns confirm the formation of a single phase of cubic spinel structure in all the prepared samples . XRD analysis showed that the increase in the cobalt concentration causes an increase in the lattice constant, bulk density (ρm) and the x-ray density (ρx), whereas porosity (p) and crystallite size (D) decrease. The Topography of the surface observed was found to be more uniform and homogeneous when the cobalt concentration increases, leading to a decrease in the roughness of the surface while average grains size increases. The FTIR spectra show two absorption bands, namely the high frequency band (υ1) in the range (1078-1081) cm-1 and the low frequency band (υ2) in the range (418–459) cm-1, which due to the vibrations of the tetrahedral and octahedral sites of Fe+3–O−2, respectively, these bands confirm the spinel structure of the prepared ferrite nanoparticles. Vickers hardness was found to increase with cobalt concentration increases.
In this work, functionally graded materials were synthesized by centrifugal technique at different
volume fractions 0.5, 1, 1.5, and 2% Vf with a rotation speed of 1200 rpm and a constant rotation time, T
= 6 min . The mechanical properties were characterized to study the graded and non-graded nanocomposites
and the pure epoxy material. The mechanical tests showed that graded and non-graded added alumina
(Al2O3) nanoparticles enhanced the effect more than pure epoxy. The maximum difference in impact strength
occurred at (FGM), which was loaded from the rich side of the nano-alumina where the maximum value was
at 1% Vf by 133.33% of the sample epoxy side. The flexural strength and Young modulus of the fu
In batch experiments, a natural chitosan adsorbent was employed to extract cobalt ions from industrial wastewater under varied parameters of starting concentration, adsorbent weight, pH, and contact duration. The adsorbent was examined using FTIR, XRD, and AFM. For an initial cobalt ion concentration of 5x10-2 mol/l at pH 6, time 35 minutes, temperature 25 °C, and adsorbing dose 0.1 g, the results showed a maximum removal percentage of 99.0 percent. The Freundlich isotherm and the pseudo-second order kinetic model both suit the experimental data well. According to thermodynamic studies, the process was spontaneous and endothermic.
Background : Knee flexors tightness has been documented in apparently healthy adults and in those with musculoskeletal problems, but the influence of age on the tightness has not been studied in Iraq. This study was therefore designed to determine the influence of age on knee flexors tightness in apparently healthy subjects.Methods: Knee flexors tightness was measured using the active knee extension test (AKET) in 200 apparently healthy male and female subjects, aged 13 to 59 years. The subjects were recruited into 5 age groups using the purposive sampling technique.Knee flexors tightness was compared across the age groups using one-way analysis ofvariance (ANOVA). The independent t-test was used to compare knee flexors tightness on both
... Show MoreWith the revolutionized expansion of the Internet, worldwide information increases the application of communication technology, and the rapid growth of significant data volume boosts the requirement to accomplish secure, robust, and confident techniques using various effective algorithms. Lots of algorithms and techniques are available for data security. This paper presents a cryptosystem that combines several Substitution Cipher Algorithms along with the Circular queue data structure. The two different substitution techniques are; Homophonic Substitution Cipher and Polyalphabetic Substitution Cipher in which they merged in a single circular queue with four different keys for each of them, which produces eight different outputs for
... Show MoreBackground: the placement of orthodontic appliances creates a favorable environment for the accumulation of microbiota, therefore this study is to assess
the relationship between removable orthodontic appliance and oral microflora.
Materials and methods: a sample 45 patients who come to orthodontic department at the collage of dentistry/Baghdad university, divided into 3 groups:
group 1 (15) without appliance, group2 (15) with appliance for 2 weeks-2 months, and group 3 (15) with appliance for 2 -4 months, then examine the oral microflora
and compared between the 3 groups.
Results: the result showed eleven types of microorganisms appear in group 3 then followed by seven types in group 2 but only three t
the films of cdse pure and doped with copper ratio glass substrate effect od cucomcentration technique thikness doped with copper is an anonmg and the density of state increases
Zinc sulfide(ZnS) thin films of different thickness were deposited on corning glass with the substrate kept at room temperature and high vacuum using thermal evaporation technique.the film properties investigated include their absorbance/transmittance/reflectance spectra,band gap,refractive index,extinction coefficient,complex dielectric constant and thickness.The films were found to exhibt high transmittance(59-98%) ,low absorbance and low reflectance in the visible/near infrared region up to 900 nm..However, the absorbance of the films were found to be high in the ultra violet region with peak around 360 nm.The thickness(using optical interference fringes method) of various films thichness(100,200,300,and 400) nm.The band gap meas
... Show MoreThe rheological and fusion behavior of polyvinyl chloride (PVC) compounds plays a dominant role in
the processing operations and in the development of physical properties in the processed material. A
comprehensive study was made in this work to evaluate the effect of shear and thermal history on stability, mechanical and rheological properties of rigid PVC compounds. Different samples of Rigid Poly vinyl chloride including dry blend powder, granules, and bottles molded from both were examined. A study was also made on recycled RPVC where 25% of reclaimed material was continuously blended with fresh dry blend and processed for 15 cycles. Results showed that compaction of the PVC material took place in the brabender plastograph at co
This study aimed to explore whether green synthesized copper nanoparticles (CuNPs) can function as an anti-biofilm agent produced by P. mirabilis. The nanoparticles were synthesized from cells free extract of P. mirabilis. Characterization of biosynthesized copper nanoparticles was carried out to determine the chemical and physical properties of the product using atomic-force microscopy (AFM), transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD) and UV-visible spectroscopy. The hexagonal structure was confirmed by XRD, size range was marked 13-19nm by TEM. FESEM was used to confirm the surface morphology. AFM analysis was used to reveal the roughne
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