The influence of Cr3+ doping on the ground state properties of SrTiO 3 perovskite was evaluated using GGA-PBE approximation. Computational modeling results infered an agreement with the previously published literature. The modification of electronic structure and optical properties due to Cr3+ introducing into SrTiO 3 were investigated. Structural parameters assumed that Cr3+ doping alters the electronic structures of SrTiO 3 by shifting the conduction band through lower energies for the Sr and Ti sites. Besides, results showed that the band gap was reduced by approximately 50% when presenting one Cr3+ atom into the SrTiO 3 system and particularly positioned at Sr sites. Interestingly, substituting Ti site by Cr3+ led to eliminating the band gap indicated a new electrical case of transferring semiconducting material into a conducting material which intern enhance conductivity. Furthermore, it was found that Cr 3+ doping either at Sr or Ti positions could effectively develop the SrTiO3 dielectric constant properties. In addition, the absorption spectra was extended to cover the visible light region of the electromagnetic radiation, indicating the capability of this compound in harvesting sunlight for solar cell applications. Consequently, it can be said that Cr 3+ is an effective dopant which opening up new prospects for various industrial and technological applications.
The present study aimed to identify teaching problems which facing the teachers for first three grades classes, and if these problems different according to some variables teacher qualification, experience period, class grade). The study sample consist of (137 )
female teachers who teach the first three grades in Braimy city in Oman, teachers spread in five government schools. Both researchers developed questionnaire to measure problems faced by the mentioned teachers, consist of 50 questions distributed into 4 dimensions (teacher, students, the curriculum, the evaluations), Also researchers checked questionnaire validity and stability. The results indicate to: The most common probl
... Show MoreObjective: To conduct a standardized method for cavity preparation on the palatal surface of rat maxillary molars and to introduce a standardized method for tooth correct alignment within the specimen during the wax embedding procedure to better detect cavity position within the examined slides. Materials and methods: Six male Wistar rats, aged 4-6 weeks, were used. The maxillary molars of three animals were sectioned in the frontal plane to identify the thickness of hard tissue on the palatal surface of the first molar which was (250-300µm). The end-cutting bur (with a cutting head diameter of 0.2mm) was suitable for preparing a dentinal cavity (70-80µm) depth. Cavity preparation was then performed using the same bur on the tooth surf
... Show MoreThis study is the first and new record to the spider Scytodes univittata Simon, 1882 (Araneae:Scytodidae)in Baghdad /Iraq , the spiders Scytodes univittata were collect from province Baghdad in Iraq , genus Scytodes belong to the family Scytodidae it is one of the most family are wide distribution around the world have 6 eyes and are slow moving , the genus Scytodes are known from the names spitting spiders ,.Female Scytodes univittata can be characteristic by :large round cephalothorax length:4.45 mm , abdomen length 3.50, total body length 7.95 mm and V-shaped of fovea, scutela triangle and large with long thin legs femur I have two row of spines then spineless are in IV femur , coloration is yello
... Show MoreBackground: Factor V Leiden mutation is the most common cause of hereditary thrombophilia . this mutation was found to be highly prevalent in the Eastern Mediterranean region , with recently reported prevalence of 3% in random Iraqi blood donors.
Aim of study: to document the case reports of factor V leiden in association with venous thrombosis in Iraqi patients.
Sub. & Methods: Six patients with Doppler confirmed Deep Venous thrombosis attending the Medical City Hospital were evaluated haemostatically and by PCR for the presence of factor Vleiden mutation. The patients had ages ranging between 22-60 years , and included 5 females and one male.
Results: Four were found to be heterozygous, while two were homozygous for this m
The Old World Screwworm Fly Chrysomya bezziana is a new insect pest on cattles and other domestic recor¬ded for the first from Iraq. It was first observed in cow's vagina in September of 1996 in Shaikh Hammed (Tarmiya), near Baghdad city. Chrysomya bezziana Villeneuve is well known as one of the most important insect pests of livestock. Its larvae infest living tissues by causing myiasis. In a wide range of worm-blooded host species (Spradbery and Vanningham, 1980; Spradbery and Kirk. 1992). It is widely dist¬ributed species over an extensive area of tropical and subtropical Africa, the Arabian Gulf countries, Iran. Indian subcontinent. South-East Asia. Indonesia, and as far east as Papua New Guinea (Zurapt, 1965; Djalayer et al. 1978;
... Show MoreMetal corrosion is a destructive process for many industrial operations, including oil well acidizing and acid pickling. Therefore, numerous efforts made by many researchers to control the steel corrosion. In the present work, A (E)-4-(((4-(5-mercapto-1,3,4-oxadiazol-2-yl) phenyl) amino) methyl)-2-methoxyphenol (MOPM) has been synthesized and characterized as a new corrosion inhibitor for mild steel in 0.1 M hydrochloric acid. FTIR and 1 HNMR were used in the diagnosis of MOPM, while electrochemical polarization technique was employed to test the performance of inhibitor at various temperatures and inhibitor concentrations. Electrochemical studies showed that MOPM acts as a mixed-type inhibitor with a maximum inhibition efficiency of
... Show MoreIn the present study, a novel ligand (L) made of 2-hydroxynaphthaldehyde and 3-hydrazone-1,3-dihydro-indole-2-one(3-[(3-hydroxynaphthalen-2-yl-ethylidene)-hydrazono]-1,3-dihydro-indol-2-one). The ligand was characterized by FTIR, UV-vis, mass, 1H-NMR, 13C-NMR, and CHN elemental analysis. New complexes of this ligand were created by treating methanol and a drop of DMF solution of the produced ligand with the hydrated metal salts of Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) in a molar ratio of 2:1 (L:M). As a result, complexes have been emerged and identified FTIR, UV-vis, C.H.N., chloride-containing, molar conductance, magnetic susceptibility, and atomic absorption. The characterization result for each complex indicated complexes wi
... Show MoreBanks represents financial institutions that influence the economy of any country and their evolution and development is the need to seek all states , communities, maintain and control a guarantee of the beneficiaries investors and to promote confidence, so the specialized organizations trying to set principles and rules must be adhered to and are Basel (II) of the necessary effects to be introduced and work on their application. Banks exposed by various risks one of them operational risks that have multiple effects on the activity of the institution itself, as well as the national economy, so this study was to find out what those effects and to find solutions and appropriate proposals to avoid Iraqi banks from the effects of risk,
... Show MoreSamarium ions (Sm +3), a rare-earth element, have a significant optical emission within the visible spectrum. PMMA samples, mixed with different ratios of SmCl3.6H2O, were prepared via the casting method. The composite was tested using UV-visible, photoluminescence and thermogravimetric analysis (TGA). The FTIR spectrometry of PMMA samples showed some changes, including variation in band intensity, location, and width. Mixed with samarium decreases the intensity of the CO and CH2 stretching bands and band position. A new band appeared corresponding to ionic bonds between samarium cations with negative branches in the polymer. These variations indicate complex links between the Sm +3 ion and oxygen in the ether group. The optical absorption
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