Porous silicon (PS) layers were formed on n-type silicon (Si) wafers using Photo- electrochemical Etching technique (PEC) was used to produce porous silicon for n-type with orientation of (111). The effects of current density were investigated at: (10, 20, 30, 40, and50) mA/cm2 with etching time: 10min. X-ray diffraction studies showed distinct variations between the fresh silicon surface and the synthesized porous silicon. The maximum crystal size of Porous Silicon is (33.9nm) and minimum is (2.6nm) The Atomic force microscopy (AFM) analysis and Field Emission Scanning Electron Microscope (FESEM) were used to study the morphology of porous silicon layer. AFM results showed that root mean square (RMS) of roughness and the grain size of porous silicon decreased as etching current density increased and FESEM showed that a homogeneous pattern and confirms the formation of uniform porous silicon. The chemical bonding and structure were investigated by using Fourier transformation infrared spectroscopy (FTIR). The band gap of the samples obtained from photoluminescence (PL). These results showed that the band gap of porous silicon increase with increasing porosity.
Copper oxide thin films were deposited on glass substrate using Successive Ionic Layer Adsorption and Reaction (SILAR) method at room temperature. The thickness of the thin films was around 0.43?m.Copper oxide thin films were annealed in air at (200, 300 and 400°C for 45min.The film structure properties were characterized by x-ray diffraction (XRD). XRD patterns indicated the presence of polycrystalline CuO. The average grain size is calculated from the X-rays pattern, it is found that the grain size increased with increasing annealing temperature. Optical transmitter microscope (OTM) and atomic force microscope (AFM) was also used. Direct band gap values of 2.2 eV for an annealed sample and (2, 1.5, 1.4) eV at 200, 300,400oC respect
... Show MoreIn this experimental and numerical analysis, three varieties of under-reamed piles comprising one bulb were used. The location of the bulb changes from pile to pile, as it is found at the bottom, center, and top of the pile, respectively.
The experiment was conducted at the period from 20th Dec. 2015 to 30th Mar. 2016 to know the effect of growth medium and nodes number on the acclimatization success of tissue propagated potatoes seedlings (Burrin class) and study some plant physiological properties. The first experiment involved testing growth media: loam, peat moss, and perlite with different portions (1:1) to plant tissue propagated potato tubers, while the second experiment involved testing the nodes number where 9, 8, 7, 6, and 5 plant nodes were chosen. Results of the first experiment showed the superiority of the culture media of peat moss + perlite to other culture media by giving the higher values of shoot system studied properties: plant height, branches number, le
... Show MoreThe purpose and goal of the research revolve around the diagnosis of intellectual capital as the logical indicator to study an effective human resource management practice and its influential role in determining the overall quality management of higher education institutions and scientific research in Baghdad.
To achieve the purpose of the research, an upgraded standard questionnaire was used to collect data and distribute it to the selected sample in a statistical manner from the study population of (5) institutions affiliated with the Ministry of Higher Education and Scientific Resear
... Show MoreAquatic macrophyte communities and environmental factors were studied at four Al-Hawizeh marsh sites from December 2017 until November 2018. Quantitative data from thirty species of aquatic plants were collected to investigate density, vegetation cover, biomass and their relationship to the environmental factors. For emerging plants, relative abundance reached the highest values (36%) than submerged and wet species, while free-floating plants produced the lowest value (17%).Physical and chemical properties have been studied including water temperature ranging from 11.3 ° C in January to 31.4 ° C in August, dissolved oxygen (DO)ranging from 1.88 mg/L in September to 10.5 mg / L in Ap
Abstract
The current research aims to identify the typical effect of Flower and Coscroft on expressive performance and the development of lateral thinking among literary fifth-grade students. To achieve the research objective, the researcher chose a sample of (90) female students from the fifth literary grade, with two experimental groups and a control group. The research groups are of six subjects. The research found that the two experimental groups have more expressive performance than the control group. Students of the first experimental group outperformed the students of the second experimental group in expressive performance and lateral thinking tests. In light of the findings of the research, the researcher
... Show MoreObjective: The aim of this study was to evaluate the effect of pumice, burning investment material
and black sand on the surface roughness of heat cure acrylic resin.
Methodology: Sixty specimens were prepared from pink heat cure acrylic resin, the specimens
where grouped into; 20 specimens which polished with pumice and water (control group); 20
specimens which polished with investment material (after burning it) and water; and 20 specimens
which polished with black sand and water. The average surface roughness of specimens after
polishing procedure had been determined by profilometer (surface roughness tester).
Results: Through the application of ANOVA and LSD tests, the result of this study showed that there
wa
Background: White spot lesion is the first visible sign of dental caries that is characterized by demineralized lesion underneath an intact surface. Several studies demonstrated that they could be treated using noninvasive techniques like the use of fluoride or casein phospho-peptide and amorphous calcium phosphate. Improvement in aesthetic outcomes by covering the demineralized enamel is one of the advantages of the use of resin infiltration and opal-ustre microabrasion, which are two new techniques that had been used for treatment of white spot lesion. The purpose of this study was to evaluate the impact of resin infiltration and microabrasion in the microhardness of the artificial white spot lesions at various depths. Material and method
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