This contribution aims to investigate volume-dependent thermal and mechanical properties of the two most studied phases of molybdenum nitride (c-MoN and h-MoN) by means of the quasi-harmonic approximation approach (QHA) via first-principles calculations up to their melting point and a pressure of 12 GPa. Lattice constants, band gaps, and bulk modulus at 0 K match corresponding experimental measurements well. Calculated Bader’s charges indicate that Mo–N bonds exhibit a more ionic nature in the cubic MoN phase. Based on estimated Gibbs free energies, the cubic phase presents thermodynamic stability higher than that detected for hexagonl, with no phase transition observed in the selected T–P conditions as detected experimentally. The elastic stiffness coefficients of MoN in hexagonal structure revealed that it is stable elastically; in contrast to the cubic structure. The temperature dependence on the bulk modulus is more profound on the dense cubic phase than on the hexagonal phase. Overall, the two considered structures of molybdenum nitride display very minimal harmonic effects, evidenced by the slight variation of thermal and mechanical properties with the increase of pressure and temperature. The optical conductivity of both phases near a zero photon energy coincides well with their metallic character inferred by their corresponding DOS curves. It is expected that the thermo-elastic properties of saturated molybdenum nitrides reported in this study will aid in the continuous pursuit to enhance their catalytic and mechanical utilizations.
Background: Esthetic treatment is the options of patient seeking orthodontic treatment. Therefore this study was conducted to measure the concentration of Aluminum, Nickel, Chromium and Iron ions released from combination of monocrysralline brackets with different arch wires immersed in artificial saliva at different duration, to evaluate the corrosion point on different parts of the orthodontic appliances before and after immersion in artificial saliva, and to evaluate the corrosion potential of each group of the orthodontic appliances. Material and methods: Eighty orthodontic sets prepared. Each set represents half fixed orthodontic appliance, from the central incisor to the first molar, for the maxillary arch, each set consisted of molar
... Show MoreThe novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused a pandemic of coronavirus disease 2019 (COVID-19) which represents a global public health crisis. Based on recent published studies, this review discusses current evidence related to the transmission, clinical characteristics, diagnosis, management and prevention of COVID-19. It is hoped that this review article will provide a benefit for the public to well understand and deal with this new virus, and give a reference for future researches.
The hydrological process has a dynamic nature characterised by randomness and complex phenomena. The application of machine learning (ML) models in forecasting river flow has grown rapidly. This is owing to their capacity to simulate the complex phenomena associated with hydrological and environmental processes. Four different ML models were developed for river flow forecasting located in semiarid region, Iraq. The effectiveness of data division influence on the ML models process was investigated. Three data division modeling scenarios were inspected including 70%–30%, 80%–20, and 90%–10%. Several statistical indicators are computed to verify the performance of the models. The results revealed the potential of the hybridized s
... Show MoreEncasing glass fiber reinforced polymer (GFRP) beam with reinforced concrete (RC) improves stability, prevents buckling of the web, and enhances the fire resistance efficiency. This paper provides experimental and numerical investigations on the flexural performance of RC specimens composite with encased pultruded GFRP I-sections. The effect of using shear studs to improve the composite interaction between the GFRP beam and concrete was explored. Three specimens were tested under three-point loading. The deformations, strains in the GFRP beams, and slippages between the GFRP beams and concrete were recorded. The embedded GFRP beam enhanced the peak loads by 65% and 51% for the composite specimens with and without shear connectors,
... Show MoreThe involvement of maxillofacial tissues in SARS‐CoV‐2 infections ranges from mild dysgeusia to life‐threatening tissue necrosis, as seen in SARS‐CoV‐2‐associated mucormycosis. Angiotensin‐converting enzyme 2 (ACE2) which functions as a receptor for SARS‐CoV‐2 was reported in the epithelial surfaces of the oral and nasal cavities; however, a complete understanding of the expression patterns in deep oral and maxillofacial tissues is still lacking.
The immunohistochemical expression of ACE2 was analyzed in 95 specimens from maxillofacial tissues and 10 specimens o
Abstract: Fluoroquinolones drugs are an important class of wide
... Show MoreThe current study aims to identify the level of adaptation of the curriculum for visually handicapped pupils from the point of view of their teachers as well as to identify the level of adaptation of the educational programs offered to visually handicapped pupils from the point of view of their teachers. In order to achieve the goals of the research, the researcher developed two tools to measure the adaptation of curricula and educational programs for pupils with visual handicapped from the point of view of teachers. The sample included (60) teachers from Al Noor Institute for Blinders in Baghdad, the two tools were applied to them, and then the Reliability and Validity coefficients were extracted. The results sh
... Show MoreGypseous soil covers approximately 30% of Iraqi lands and is widely used in geotechnical and construction engineering as it is. The demand for residential complexes has increased, so one of the significant challenges in studying gypsum soil due to its unique behavior is understanding its interaction with foundations, such as strip and square footing. This is because there is a lack of experiments that provide total displacement diagrams or failure envelopes, which are well-considered for non-problematic soil. The aim is to address a comprehensive understanding of the micromechanical properties of dry, saturated, and treated gypseous sandy soils and to analyze the interaction of strip base with this type of soil using particle image
... Show MoreThe contractual imbalance is perceived today by the majority of the doctrine as being one of the pitfalls to the execution of the contracts. As a result, most legislations grant judges the power to intervene to restore it. Granting the judge the power to complete the contract raises the question of the extent to which the judge can obtain such power. Is it an absolute authority that is not limited? If so, is it a broad discretion in which the judge operates in his conscience, or is it a power of limited scope by specific legal texts and conventions? This is what we will try to answer in this research.