Rare earth metal oxides (REMOs) have gained considerable attention in recent years owing to their distinctive properties and potential applications in electronic devices and catalysts. Particularly, cerium dioxide (CeO2), also known as ceria, has emerged as an interesting material in a wide variety of industrial, technological, and medical applications. Ceria can be synthesized with various morphologies, including rods, cubes, wires, tubes, and spheres. This comprehensive review offers valuable perceptions into the crystal structure, fundamental properties, and reaction mechanisms that govern the well-established surface-assisted reactions over ceria. The activity, selectivity, and stability of ceria, either as a stand-alone catalyst or as supports for other metals, are frequently ascribed to its strong interactions with the adsorbates and its facile redox cycle. Doping of ceria with transition metals is a common strategy to modify the characteristics and to fine-tune its reactive properties. DFT-derived chemical mechanisms are surveyed and presented in light of pertinent experimental findings. Finally, the effect of surface termination on catalysis by ceria is also highlighted.
Jatropha L. is an exotic genus to Iraq and it has been cultivated in gardens for ornamental purposes because of the shiny red color of the flowers. The plant adapted to environmental conditions and succeeded in growing and blooming, which is why the species was interested to study. The species Jatropha integerrima Jacq. was examined and diagnosed for the first time in Iraq. Morphological and anatomical characteristics for leaves (considering that the variations are the most reliable and taxonomically important) were provided. The Phytochemical screening showed the presence of alkaloids, flavonoids, terpenes, tannins and saponins. The qualitative analysis by TLC indicated the presence of alkaloids and flavonoid that was detected by specia
... Show MoreBasically, this study aims to identify the extent to which Iraqi secondary school students use writing strategies and how proficiency level and students gender could affect writing strategy use. The study also examines the relationship between writing achievement and writing strategy use among Iraqi secondary school students. For this purpose, 140 Iraqi secondary school students were selected randomly from six different schools. Petric and Czarl’s questionnaire (2003) was adopted in the study as an instrument to collect the needed data. A software of SPSS used to analyze the collected data. The findings revealed that secondary school students appeared as low users of writing strategies; low proficient students do not show a sta
... Show MoreIn this paper, a theoretical study of the energy spectra and the heat capacity of one electron quantum dot with Gaussian Confinement in an external magnetic field are presented. Using the exact diagonalization technique, the Hamiltonian of the Gaussian Quantum Dot (GQD) including the electron spin is solved. All the elements in the energy matrix are found in closed form. The eigenenergies of the electron were displayed as a function of magnetic field, Gaussian confinement potential depth and quantum dot size. Explanations to the behavior of the quantum dot heat capacity curve, as a function of external applied magnetic field and temperature, are presented.
The development of information systems in recent years has contributed to various methods of gathering information to evaluate IS performance. The most common approach used to collect information is called the survey system. This method, however, suffers one major drawback. The decision makers consume considerable time to transform data from survey sheets to analytical programs. As such, this paper proposes a method called ‘survey algorithm based on R programming language’ or SABR, for data transformation from the survey sheets inside R environments by treating the arrangement of data as a relational format. R and Relational data format provide excellent opportunity to manage and analyse the accumulated data. Moreover, a survey syste
... Show MoreThe research aims to evaluate Islamic electronic libraries and their service for downloading research and illustrated books, explaining their origins, features and types. The research was limited to the libraries available on the Internet that provide the service for downloading research and illustrated books. The researcher relied on the survey approach to identify the libraries and a sample of them (20 libraries) was selected. For the purpose of evaluating it according to five criteria related to the preparation and publication of Islamic electronic libraries (the responsible party, the goals and objectives, the year, the services it provides, the sections and subject specializations of its contents) and five criteria related to the servi
... Show MoreThe present work aimed to study the efficiency of nanofiltration (NF) and reverse osmosis (RO) membrane for heavy metal removal from wastewater and study the factors affecting the performance of these two membranes: feed concentrations for heavy metal ions, pressure, and flow rate. The experimental results showed, heavy metals concentration in permeate increase with raise in feed concentrations, decline with increase in flow rate. The raise of pressure, heavy metals concentration decreases for RO membrane, but for NF membrane the concentration decrease and then at high pressure increase. The rejection percentage for chromium in NF and RO is 99.7% and 99.9%, for copper is 98.4% and 99.3%, for zinc is 97.9% and 99.5%, for nickel is 97.2% and
... Show MoreNew metal complexes of some transition metal ions Co(II), Cu(II) , Cd(II) and Zn(II) were prepared by their reaction with previously prepared ligands HLI= (P-methyl anilino) phenyl acetonitrile and HLII = (P-methyl anilino) –P– chloro phenyl acetonitrile . The two ligands were prepared by Strecker’s procedure which includ the reaction of p- toluidine with benzaldehyde and P- chlorobenzaldehyde respectively. Structures were proposed depending on atomic absorption , i.r. and u.v.visible spectra in addition to magnetic susceptibility and electrical conductivity measurements.
Background: Staphylococcus spp. are widely distributed in nature and can cause nosocomial, skin infections, and foodborne illness, and it may lead to severe financial losses in birds by causing systemic infection in numerous organs. Aim: This study was conducted to determine the prevalence of Staphylococcus spp. in humans and birds in Baghdad city. Methods: Seventy-six oral cavity swabs were collected, including 41 from birds and 35 from breeders. All samples were examined by bacteriological methods and identified by using the VITEK technique, the samples were then further studied to test the ability of biofilm formation, and MDR factors and MAR index were tested with the use of seven antibiotics. Results: Among the 76 oral swa
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