This work deals with the study of the morphodynamics, history of development of landforms and the origin of the Ga’ara depression. The depression is a suboval erosional topographic feature extending in E-Wdirection and located about 50 km north of Rutba Town, at the Western Desert of Iraq. The area is characterized by fresh and clean surfaces, scarcity of vegetation, abundance of rills, intense drainage and immature soil. These clues indicate that the erosion in the study area is effective. Four types of erosion features are recognized in this area namely sheet, rill, badland and wind erosion. The extent of the wind erosion depends on its position in relation to the prevailing wind direction. Water, wind and gravity are the main agents of erosion although the former seems more effective. In general, the valleys are dense in the hard rocks which indicate intensive erosion. Two types of drainage pattern can be distinguished in the study area, a dendritic pattern, especially at the exposure area of the Mulussa dolostone, and a centripetal pattern at the central part of the depression at the confluence of the main wadis. The valleys are V-shaped in their upper reaches and gradually change to flat-bottom shallow valleys in their lower reaches. Two major types of mass wasting are recognized, namely, rock fall and slump. Rock fall is the most common process whereby most of the talus accumulates at the base of the cliff. Slump is frequent at the south and southwestern rims of the depression. The slope surfaces are generally composite of the type free-face concave pediment. The depression is asymmetrical having steeper slopes in the south and thewestwhereas the northern and eastern scarps are wider and gentler, respectively. History of landform development is investigated in the Ga’ara area. Seven episodes are distinguished according to emergence and paleoclimatic conditions. The landforms of the study area were formed and further developed during the emergence episodes. The history of the development of the Ga’ara depression is studied too.
This contribution provides an atomistic understanding into the impact of W, Nb, and Mo co-substitution at Hf-site of cubic HfO2 lattice to produce Hf1−xTMxO2 system at x = 25%. The calculations have been performed under the framework of density functional theory supported by Habbured parameter (DFT+U). Structural analysis demonstrates that the recorded lattice constants is in good coherence with the previously published results. For the lattice parameters, contraction by 1.33% comparing with the host system has been reported. Furthermore, the doping effect of TM on the band gap leads to its reduction in the resulting Hf0.75TM0.25O2 configurations. The partial density of states (PDOS) indicate that hybridization through localized electroni
... Show MoreThis work presents a five-period chaotic system called the Duffing system, in which the effect of changing the initial conditions and system parameters d, g and w, on the behavior of the chaotic system, is studied. This work provides a complete analysis of system properties such as time series, attractors, and Fast Fourier Transformation Spectrum (FFT). The system shows periodic behavior when the initial conditions xi and yi equal 0.8 and 0, respectively, then the system becomes quasi-chaotic when the initial conditions xi and yi equal 0 and 0, and when the system parameters d, g and w equal 0.02, 8 and 0.09. Finally, the system exhibits hyperchaotic behavior at the first two conditions, 0 and 0, and the bandwidth of the chaotic
... Show MoreThis research focuses on the epidemic of Job burnout and seeks to achieve sustainable preeminence among the employees of the University of Baghdad. It also identifies the meaning of the differences between the two genders of males and females according to the variables, and it also does the correlation between the two variables. First, the two researchers developed a test of job burnout that incorporates 18 items, which has been proven to be statistically fit. Moreover, they developed a competitive superiority measure consisting of 22 items in it, and its psychometric properties confirm their fit. The two tools were applied to a sample of 120 employees who were randomly selected from six colleges at the University of Baghdad, alongside univ
... Show MoreObjectives: The purpose of this in vitro study was to compare the effect of adding poloxamer surfactant to irrigant solutions on the penetration de..
Generally the a.c. conductivity shows a power law in frequency s () where the exponent s ≤ 1. As the frequency goes to zero the conductivity become frequency independent. The a.c. conductivity was studied for the Ge1-xSex thin films to see how the selenium contents affect the permittivity and the permeability for the Ge1-x Sex. The thin films prepared by thermal evaporation at room temperature and under vacuum (~2 x10-5toor) using Edward coating unit model 306A. From the relation between ln conductivity and ln w, the effect of selenium contents in Ge1-x Sex thin films on the exponent value, the relaxation time and the maximum barrier height. An algebric fitting method for circles and circular arcs was used to find the permit
... Show MoreFor a mathematical model the local bifurcation like pitchfork, transcritical and saddle node occurrence condition is defined in this paper. With the existing of toxicity and harvesting in predator and prey it consist of stage-structured. Near the positive equilibrium point of mathematical model on the Hopf bifurcation with particular emphasis it established. Near the equilibrium point E0 the transcritical bifurcation occurs it is described with analysis. And it shown that at equilibrium points E1 and E2 happened the occurrence of saddle-node bifurcation. At each point the pitch fork bifurcation occurrence is not happened.