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.
In developing countries, individual students and researchers are not able to afford the high price of the subscription to the international publishers, like JSTOR, ELSEVIER,…; therefore the governments and/or universities of those countries aim to purchase one global subscription to the international publishers to provide their educational resources at a cheaper price, or even freely, to all students and researchers of those institutions. For realizing this concept, we must build a system that sits between the publishers and the users (students or researchers) and act as a gatekeeper and a director of information: this system must register its users and must have an adequate security to e
... Show MorePhenol oxidation by Fenton's reagent (H2O2 + Fe+2) in aqueous solution has been studied for the purpose of learning
more about the reactions involved and the extent of the oxidation process, under various operating conditions. An initial
phenol concentration of 100 mg/L was used as representative of a phenolic industrial wastewater. Working temperature
of 25C was tested, and initial pH was set at 5.6 . The H2O2 and the Fe+2 doses were varied in the range of
(H2O2/Fe+2/phenol = 3/0.25/1 to 5/0.5/1). Keeping the stirring speed of 200 rpm.
The results exhibit that the highest phenol conversion (100%) was obtained under (H2O/Fe+2/phenol ratio of 5/0.5/1)
at about 180 min. The study has indicated that Fenton's oxidation i
A field experiment was conducted at experimental field of Mechanization Agriculture , the
College of Agriculture , Abu – Ghraib , University of Baghdad .To measure transmitted vibration to
seat tractor during operation tillage , mold board plow with New Holland 66-S- 80 tractor as one
machinery unit , Soil was treated at soil constant moisture ( 18 – 20 % ) with two depths of plowing
(15 and 20 cm ) and three speed of tractor 2.0 , 3.5, 6.8 km / h . Three main dimensions in seat
tractor measurement vertical, longitudinal and lateral acceleration. Split plot design under
completes block design with three replicates
(1)
If the Industrial Revolution has enabled the replacement of humans with machines, the digital revolution is moving towards replacing our brains with artificial intelligence, so it is necessary to consider how this radical transformation affects the graphic design ecosystem. Hence, the research problem emerged (what are the effects of artificial intelligence on graphic design) and the research aimed to know the capabilities and effects of artificial intelligence applications in graphic design, and the study dealt in its theoretical framework with two main axes, the first is the concept of artificial intelligence, and the second is artificial intelligence applications in graphic design. The descriptive approach adopted a method of content
... Show More
(1)
The study aimed to design a test of pre-writing skills for public kindergartens in Baghdad city. The test consisted of (25) items applied on a sample of (150) kindergarteners to identify these skills as well as to identify the significant difference between male and female children and if there is a difference between pre-school children and kindergarteners. The results showed the presence of pre-writing skills with a high degree in kindergarten children. The differences were clear in these skills between male and female children and those in pre-school than those in kindergartens. The researcher suggested a number of recommendations and proposals.
Pancreatic adenocarcinoma is one of the major causes of cancer death in the world. Alterations in p53 tumor suppressor gene
Fatigue cracking is the most common distress in road pavement. It is mainly due to the increase in the number of load repetition of vehicles, particularly those with high axle loads, and to the environmental conditions. In this study, four-point bending beam fatigue testing has been used for control and modified mixture under various micro strain levels of (250 μƐ, 400 μƐ, and 750 μƐ) and 5HZ. The main objective of the study is to provide a comparative evaluation of pavement resistance to the phenomenon of fatigue cracking between modified asphalt concrete and conventional asphalt concrete mixes (under the influence of three percentage of Silica fumes 1%, 2%, 3% by the weight of asphalt content), and (chan
... Show More
(4)
(1)
