ZnO nanostructures were synthesized by hydrothermal method at different temperatures and growth times. The effect of increasing the temperature on structural and optical properties of ZnO were analyzed and discussed. The prepared ZnO nanostructures were characterized by X-ray diffraction (XRD), UV–Vis. absorption spectroscopy (UV–Vis.), Photoluminescence (PL), and scanning electron microscopy (SEM). In this work, hexagonal crystal structure prepared ZnO nanostructures was observed using X-ray diffraction (XRD) and the average crystallite size equal 14.7 and 23.8 nm for samples synthesized at growth time 7 and 8 hours respectively. A nanotubes-shaped surface morphology was found using scanning electron microscopy (SEM). The optical properties showed that the samples had good absorbance in the UV-Vis. region and wide band gap. The PL spectrum displayed that the intensity of ultraviolet (UV), band gap and defect bands depend on the growth temperature of the ZnO nanostructure. The largest band gap was 3.351 eV for ZnO nanostructure synthesized at 100 °C and growth time 8h.
Abstract: Under high-excitation irradiance conditions to induce fluorescence, the dependence of photobleaching of Coumarin 307 (C307) and acriflavine (ACF) laser dyes in liquid and solid phases have been studied. A cw LD laser source of 1 mW and 407 nm wavelength was used as an exciting source. For one hour exposure time, it was found that the solid dye samples suffer photobleaching more than the liquid dye samples. This is because in liquid solutions the dye molecules can circulate during the irradiation, while the photobleaching is a serious problem when the dye is incorporated into solid matrix and cannot circulate.
Carbon fibre reinforced polymers are widely used to strengthen steel structural elements. These structural elements are normally subjected to static, dynamic and fatigue loadings during their life-time. A number of studies have focused on the characteristics of CFRP sheets bonded to steel members under static, dynamic and fatigue loadings. However, there is a gap in understanding the bonding behaviour between CFRP laminates and steel members under impact loading. This paper shows the effect of different load rates from quasi-static to 300 × 103 mm/min on this bond. Two types of CFRP laminate, CFK 150/2000 and CFK 200/2000, were used to strengthen steel joints using Araldite 420 epoxy. The results show a significant bond strength enhancemen
... Show MoreThe digital camera which contain light unit inside it is useful with low illumination but not for high. For different intensity; the quality of the image will not stay good but it will have dark or low intensity so we can not change the contrast and the intensity in order to increase the losses information in the bright and the dark regions. . In this search we study the regular illumination on the images using the tungsten light by changing the intensities. The result appears that the tungsten light gives nearly far intensity for the three color bands(RGB) and the illuminated band(L).the result depend on the statistical properties which represented by the voltage ,power and intensities and the effect of this parameter on the digital
... Show MoreTwo field experiments were carried out for cultivating yellow maize crop Zea mays L. during the autumn planting season 2019 in two sites with soils of different textures. The first site is a loamy texture in one of the fields of the Medhatia Agriculture Division, Babylon Governorate. The second was silty loam by an alluvial mixture in one of the fields of Al-Nouriah Research Station, Ministry of Agriculture located in Al-Nouriah sub-district, Al-Qadisiyah governorate. It was found through the results that the uniformity, efficiency, and adequacy of the irrigation efficiency of the sprinkler irrigation method is better than that of the sprinkler irrigation method, and it ranged between (88.6-88.7) for uniformity and (84-86)% of the irrigatio
... Show MoreThe preparation of a new Azo compounds of highly conjugated dimeric and polymeric liquid crystal to achieve the crystalline characteristics Which have structures assigned based on elemental analysis, IR 1HNMR and CHNS-O while mesogenic properties have been set for DSC and hot-stage polarizing optical microscopy. The compounds show enantiotropicnematic phase being displayed. The compounds show photoluminescence properties in the organic solution at room temperature, with the fluorescence band centered around 400 nm.
Motivated by the vital role played by transition metal nitride (TMN) composites in various industrial applications, the current study reports electronic properties, thermodynamic stability phase diagram, and vacancy formation energies of the plausible surfaces of NiAs and WC-type structures of δ3-MoN and δ-WN hexagonal phases, respectively. Low miller indices of various surface terminations of δ3-MoN and δ-WN namely, (100), (110), (111), and (001) have been considered. Initial cleaving of δ3-MoN bulk unit cell offers separate Mo and N terminations signified as δ3-MoN (100): Mo, δ3-MoN(100):N, δ3-MoN(111):Mo, δ3-MoN(111):Mo, and δ3-MoN(001):Mo. However, the (110) plane reveals mix-truncated with both molybdenum and nitrogen atoms i
... Show MoreLanguages were not found in our life in a way utter coincidence , and it’s not flounce on people’s tongue randomly ‚ but laws are the controlling in languages‚ these laws could be lift to the same level of natural laws‚ phonetics form the main part in producing those languages‚ the Arabic language is one of those languages ‚ it’s largest dialects in Arabian Peninsula according to speakers number ‚ Arabic language link with these dialects through properties and phenomena sound and grammar‚ from this point my topic search is came Similar and different between Arabic and Arabian peninsula Accents balance linguistic–study voice of the Seine typically ) . and Similar and different of the ph
... Show More
Liquefied petroleum gas (LPG), Natural gas (NG) and hydrogen were used to operate spark ignition internal combustion engine Ricardo E6, to compare NOx emissions emitted from the engine, with that emitted from engine fueled with gasoline as a fuel.
The study was done when engine operated at HUCR for gasoline, compared with its operation at HUCR for each fuel. Compression ratio, equivalence ratio and spark timing were studied at constant speed 25rps.
The results appeared that NOx concentrations will be at maximum value in the lean side near the stoichiometric ratio, and reduced with moving away from this ratio for mixture at both s
... Show MoreHuman cerebral cortex is the outer folded neuronal layer and represents major part of the cerebrum with enormous functions. It is a laminar structure, easily visualized grossly. Previous studies showed that the Superior Temporal gyrus is one of the thickest cerebral cortex regions, reaching (about 4 mm). The Electron microscope study was made on 6 samples taken to measure the neuronal soma dimension of the large pyramidal cells present in the internal pyramidal cortical layer V in different age groups and gender. Aging process was obvious on the large pyramidal cells of the cerebral cortex, in which their neuronal soma dimensions showed shrinkage with age progression. But statistically there was no differences in the values between males an
... Show More