Preferred Language
Articles
/
mhftXI8BVTCNdQwCyXMR
Ab initio structural and vibrational properties of GaAs diamondoids and nanocrystals
...Show More Authors

Gallium arsenide diamondoids structural and vibrational properties are investigated using density functional theory at the PBE/6-31(d) level and basis including polarization functions. Variation of energy gap as these diamondoids increase in size is seen to follow confinement theory for diamondoids having nearly equiaxed dimensions. Density of energy states transforms from nearly single levels to band structure as we reach larger diamondoids. Bonds of surface hydrogen with As atoms are relatively localized and shorter than that bonded to Ga atoms. Ga-As bonds have a distribution range of values due to surface reconstruction and effect of bonding to hydrogen atoms. Experimental bulk Ga-As bond length (2.45 Å) is within this distribution range. Tetrahedral and dihedral angles approach values of bulk as we go to higher diamondoids. Optical-phonon energy of larger diamondoids stabilizes at 0.037 eV (297 cm-1) compared to experimental 0.035 eV (285.2 cm-1). Ga-As force constant reaches 1.7 mDyne/Å which is comparable to Ga-Ge force constant (1.74 mDyne/Å). Hydrogen related vibrations are nearly constant and serve as a fingerprint of GaAs diamondoids while Ga-As vibrations vary with size of diamondoids.

Scopus Clarivate Crossref
View Publication
Publication Date
Sun Feb 01 2009
Journal Name
Materials Science And Engineering: B
Microstructure, electrical properties and Hall coefficient of europium-doped Li–Ni ferrites
...Show More Authors

View Publication
Scopus (42)
Crossref (42)
Scopus Clarivate Crossref
Publication Date
Sat Oct 01 2011
Journal Name
Iraqi Journal Of Physics
The Structure and Electrical Properties of Porous Silicon Prepared by Electrochemical Etching
...Show More Authors

Porous silicon was prepared by using electrochemical etching process. The structure, electrical, and photoelectrical properties had been performed. Scanning Electron Microscope (SEM) observations of porous silicon layers were obtained before and after rapid thermal oxidation process. The rapid thermal oxidation process did not modify the morphology of porous layers. The unique observation was the pore size decreased after oxidation; pore number and shape were conserved. The wall size which separated between pore was increased after oxidation and that effected on charge transport mechanism of PS

View Publication Preview PDF
Publication Date
Fri Jul 01 2011
Journal Name
Materials Chemistry And Physics
Gadolinium substitution and sintering temperature dependent electronic properties of Li–Ni ferrite
...Show More Authors

View Publication
Scopus (61)
Crossref (59)
Scopus Clarivate Crossref
Publication Date
Tue Jun 01 2021
Journal Name
Iop Conf. Series: Materials Science And Engineering
Enhancing the mechanical properties of lightweight concrete using mono and hybrid fibers
...Show More Authors
Abstract<p>This investigation aims to study some properties of lightweight aggregate concrete reinforced by mono or hybrid fibers of different sizes and types. In this research, the considered lightweight aggregate was Light Expanded Clay Aggregate while the adopted fibers included hooked, straight, polypropylene, and glass. Eleven lightweight concrete mixes were considered, These mixes comprised of; one plain concrete mix (without fibers), two reinforced concrete mixtures of mono fiber (hooked or straight fibers), six reinforced concrete mixtures of double hybrid fibers, and two reinforced concrete mixtures of triple hybrid fibers. Hardened concrete properties were investigated in this study. G</p> ... Show More
Crossref (4)
Crossref
Publication Date
Mon Feb 04 2019
Journal Name
Iraqi Journal Of Physics
Gamma ray effect on the properties of R590 and C480 laser dyes
...Show More Authors

In the current research, we investigated the absorption spectrum for R590 and C480 dyes in ethanol solvent for different dye solution concentrations of 10-4, 10-5 and 10-6M. These dyes have been prepared and studied before and after gamma irradiation (first, second ionization) using cesium-137 source with absorbed doses of 18.36 Gy (time exposure of 10 days) and 73.44 Gy (with time exposure of 40 days). We noticed that the absorption intensity was decreased with decreasing concentration, before gamma irradiation while the absorption spectrum peak shifted towards the short wavelength (blue shift). It was also found that the intensity of absorption spectrum increased and shifted the absorption spectrum peak towards the long wavelength (red

... Show More
View Publication Preview PDF
Crossref
Publication Date
Tue Jun 01 2021
Journal Name
Civil Engineering Journal
Marshall Performance and Volumetric Properties of Styrene-Butadiene-Styrene Modified Asphalt Mixtures
...Show More Authors

The durability of asphalt pavement is associated with the properties and performance of the binder. This work-study intended to understand the impact of blending Styrene-Butadiene-Styrene (SBS) to conventional asphalt concrete mixtures and calculating the Optimum Asphalt Content (OAC) for conventional mixture also; compare the performance between SBS modified with the conventional mixture. Two different kinds of asphalt penetration grades, A.C. (40-50) and A.C. (60-70), were improved with 2.5 and 3.5% SBS polymer, respectively. Marshall properties were determined in this work. Optimum Asphalt Content (OAC) was 4.93 and 5.1% by weight of mixture for A.C. (40-50) and (60-70), respectively. Marshall properties results show an increasem

... Show More
Scopus (13)
Crossref (10)
Scopus Clarivate Crossref
Publication Date
Tue Dec 01 2020
Journal Name
Iraqi Journal Of Physics
Wettability, Thermal Stability, and Antibacterial Properties of Polycaprolactone /ZnO Nanocomposites in Packaging
...Show More Authors

Polycaprolactone is one of the natural biodegradable polymers mainly used in bioplastics production for packaging, usually composed of non-toxic compounds and biodegradable. The aim was to examine the role of zinc oxide (ZnO) nanopowder on the,wettability , thermal and anti-bacterial effect nanocomposites.  Pure PCL and PCL-based bio- nanocomposites doped with various ratios of ZnO nanoparticles from 0% to 5wt% were prepared through the arrangement of throwing procedure.  The results show that wettability properties in relation to ideal PCL and that they were increasingly hydrophobic from 57º.8 to 69º.53 because add ZnO  nanocomposites,the thermal stability between 300 and 400 ° C makes them perfect for the application

... Show More
View Publication Preview PDF
Crossref (5)
Crossref
Publication Date
Wed Jan 01 2020
Journal Name
Advanced Composites Letters
Enhanced thermal and electrical properties of epoxy/carbon fiber–silicon carbide composites
...Show More Authors

The silicon carbide/carbon fiber (SiC/CF) hybrid fillers were introduced to improve the electrical and thermal conductivities of the epoxy resin composites. Results of Fourier transform infrared spectroscopy revealed that the peaks at 3532 and 2850 cm−1 relate to carboxylic acid O–H stretching and aldehyde C–H stretching appearing deeper with an increased volume fraction of SiC. Scanning electron microscopic image shows a better interface bonding between the fiber and the matrix when the volume fraction of SiC particles are increased. As frequency increases from 102 Hz to 106 Hz, dielectric constants decrease slightly. Dissipation factor (tan δ) values keep low a

... Show More
View Publication
Scopus (30)
Crossref (38)
Scopus Clarivate Crossref
Publication Date
Sun Feb 20 2022
Journal Name
Papers In Physics
Electronic and optical properties of nickel-doped ceria: A computational modelling study
...Show More Authors

Cerium oxide (CeO2), or ceria, has gained increasing interest owing to its excellent catalytic applications. Under the framework of density functional theory (DFT), this contribution demonstrates the eect that introducing the element nickel (Ni) into the ceria lattice has on its electronic, structural, and optical characteristics. Electronic density of states (DOSs) analysis shows that Ni integration leads to a shrinkage of Ce 4f states and improvement of Ni 3d states in the bottom of the conduction band. Furthermore, the calculated optical absorption spectra of an Ni-doped CeO2 system shifts towards longer visible light and infrared regions. Results indicate that Ni-doping a CeO2 system would result in a decrease of the band gap. Finally,

... Show More
View Publication Preview PDF
Scopus (18)
Crossref (14)
Scopus Clarivate Crossref
Publication Date
Tue Dec 09 2025
Journal Name
Petroleum And Coal
Extraction and Analysis of Compressional, Shear, and Stoneley Slowness, Rock Mechanical Properties, and Shear Anisotropy Using Sonic Scanner Data
...Show More Authors

The Sonic Scanner is a multifunctional instrument designed to log wells, assess elastic characteristics, and support reservoir characterisation. Furthermore, it facilitates comprehension of rock mechanics, gas detection, and well positioning, while also furnishing data for geomechanical computations and sand management. The present work involved the application of the Sonic Scanner for both basic and advanced processing of oil-well-penetrating carbonate media. The study aimed to characterize the compressional, shear, Stoneley slowness, rock mechanical properties, and Shear anisotropy analysis of the formation. Except for intervals where significant washouts are encountered, the data quality of the Monopole, Dipole, and Stoneley modes is gen

... Show More
View Publication Preview PDF