Abstract: In this research, nanofibers have been prepared by using an electrospinning method. Three types of polymer (PVA, VC, PMMA) have been used with different concentration. The applied voltage and the gap length were changed. It was observed that VC is the best polymer than the other types of polymers.
The nonlinear refractive (NLR) index and third order susceptibility (X3) of carbon quantum dots (CQDs) have been studied using two laser wavelengths (473 and 532 nm). The z-scan technique was used to examine the nonlinearity. Results showed that all concentrations have negative NLR indices in the order of 10−10 cm2/W at two laser wavelengths. Moreover, the nonlinearity of CQDs was improved by increasing the concentration of CQDs. The highest value of third order susceptibility was found to be 3.32*10−8 (esu) for CQDs with a concentration of 70 mA at 473 nm wavelength.
Samples of tea leaves (Green tea, Gugarate tea and Black tea used commonly in Iraq) are dried, grinded, pressed and submitted for the elemental analysis by x-ray fluorescence technique (XRF). The concentrations of major, minor and trace elements are determined. The major elements were Na, Mg, Al, K, Si, Ca, Mn, Fe, S and P. Of these elements, Ca, concentration in Gugarate tea leaves is three times, it's level in the other types of tea. Titanium, Cl, Rb and Sr are found as minor elements, while other elements such as Cu, Zn, V, Cr, Co, ...etc are found as trace elements. Of these trace elements considerable concentration values are found for some toxic elements Hg, Cd, Pb and As. Green tea contains 1.1 ppm Hg and 4.4 ppm Pb. Gugarate tea
... Show MoreThe performance of flexible pavements is significantly impacted by the permanent deformation (rutting) of asphalt pavements. Rutting shortens the pavement's useful service life and poses significant risks to those using the highway since it alters vehicle handling characteristics.. The aim of this research is to evaluate the permanent deformation of asphalt mixtures under different conditions,to achieve this aim 108 cylindrical specimens has been prepared and tested under repeated loading in uniaxial compression mode. Five factors were considered in this research, these factors represent the effect of environmental condition and traffic loading as well as mixture properties, they include testing temperature, loading condition (stress level
... Show MoreThe study included evaluation of cell surface charge and hydrophobicity of Escherichia coli, Klebsilla aerogenes, Proteus spp, Bacillus cereus, Staphylococcus epidermidis, Staphylococcus aureus(1) and Staphylococcus aureus(2) were determined by hydrocarbon adherence and hydrophobic interaction chromatography. The results showed that the negative charge of cell surface of gram negative bacteria was much higher than on gram positive once when these bacteria were grown on nutrient agar at 37 c for 18 h . E.coli was more negative charged than Klebsilla aerogenes and Proteus spp. The hydrophobicity of gram positive bacteria was much
... Show MoreThe fauna of bees (Hymenoptera, Apoidea) from different regions of Iraq is surveyed in this study; there were 16 species, 13 genera that belong to four families which are collected in this investigation.
Also, all the species that are recorded for Iraq in previous investigations are revised; totally there are 110 species, 32 genera belonging to five families: Apidae, Andernidae, Colletidae, Halictidae and Megachilidae were listed.
It has been a well-known practice to use seeds and the essential oil of Carum copticum as a strongly antiseptic , antispasmodic , aromatic , bitter , diaphoretic , digestive , diuretic , expectorant and tonic. Also used for cure influenza, asthma, and rheumatoid arthritis. To our knowledge it will be the first time to use the seeds of this herb as a urinary tract stone lithotripsy.This research aimed to the use of these seeds as a lithotripsian against different types of urinary stones and determine the efficiency of these preparation against which types of stone.A liquid solution was prepared from dissolving the seeds powder in cow milk and then concentration this prep
... Show MoreThe electron correlation effect for inter-shell have been analysed in terms of Fermi hole and partial Fermi hole for Li-atom in the excited states (1s2 3p) and (1s2 3d) using Hartree-Fock approximation (HF). Fermi hole Δf(r12) and partial Fermi hole Δg(r12 ,r1) were determined in position space. Each plot of the physical properties in this work is normalized to unity. The calculation was performed using Mathcad 14 program.
This work is concerned with the vibration attenuation of a smart beam interacting with fluid using proportional-derivative PD control and adaptive approximation compensator AAC. The role of the AAC is to improve the PD performance by compensating for unmodelled dynamics using the concept of function approximation technique FAT. The key idea is to represent the unknown parameters using the weighting coefficient and basis function matrices/vectors. The weighting coefficient vector is updated using Lyapunov theory. This controller is applied to a flexible beam provided with surface bonded piezo-patches while the vibrating beam system is submerged in a fluid. Two main effects are considered: 1) axial stretching of the vibrating beam that leads
... Show MoreA twisted-fin array as an innovative structure for intensifying the charging response of a phase-change material (PCM) within a shell-and-tube storage system is introduced in this work. A three-dimensional model describing the thermal management with charging phase change process in PCM was developed and numerically analyzed by the enthalpy-porosity method using commercial CFD software. Efficacy of the proposed structure of fins for performing better heat communication between the active heating surface and the adjacent layers of PCM was verified via comparing with conventional longitudinal fins within the same design limitations of fin material and volume usage. Optimization of the fin geometric parameters including the pitch, numb
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