A numerical computation for determination transmission coefficient and resonant tunneling energies of multibarriers heterostructure has been investigated. Also, we have considered GaN/Al0.3Ga0.7N superlattice system to estimate the probability of resonance at specific energy values, which are less than the potential barrier height. The transmission coefficient is determined by using the transfer matrix method and accordingly the resonant energies are obtained from the T(E) relation. The effects of both well width and number of barriers (N) are observed and discussed. The numbers of resonant tunneling peaks are generally increasing and they become sharper with the increasing of N. The resonant tunneling levels are shifted inside the well by increasing the well width and vice versa. These features and the transmission coefficient as a function of incident energetic particles play an important role in fabrication of high speed devices and a good factor for determination the peak-to-valley ratio of resonant tunneling devices respectively.
The most important recommendations of this research are:-
1.The benefit of the other countries experiences about the transparency of the government performance, without depending on the transparency that imitating the other experiences; that may not fit with the Iraqi government units.
2.The Ministry of Finance has to prepare the citizen guidebook about the government performance which is considered an essential document, it should be simple and available for all the parties of relation; and for not specialized citizen for the purpose of simplifying the understanding of government performance details.
3.The benefit of the government units websites of inte
... Show MoreA calculation have been carried out for determination some of the spectroscopic properties of Hydrogen Iodide HI molecules such as, the intensity of the absorption spectrum as a function of the variation of the temperature ranging from 10 to 1000 K. This study shows that the populations and hence intensity of the molecule increased as the temperature increased. Another determination of the maximum rotational quantum number Jmax of N2 , CO , BrF AgCl and HI molecules has been carried out.
in this paper the second order neutral differential equations are incestigated are were we give some new suffucient conditions for all nonoscillatory
This research paper is about thevariationin the degree of Continentality climate of the
Iraq during (40) years for a number of climate station. Using Poresof formula, it is found out
that the climate of Iraq ranges between extreme Continentality and very extreme
Continentality, and that the Continentality degree is characterized with extreme frequency
from one year to another. In certain years, the degree of climate Continentality decreases
while in other years it rises in such a way that there is no similarity in the Continental degree
from one year to another for the same station.
As for the general trend of the degree of Continentality, the last years had noticed
special variations, which are divided in to thre
For a nonempty subset X of a group G and a positive integer m , the product of X , denoted by Xm ,is the set Xm = That is , Xm is the subset of G formed by considering all possible ordered products of m elements form X. In the symmetric group Sn, the class Cn (n odd positive integer) split into two conjugacy classes in An denoted Cn+ and Cn- . C+ and C- were used for these two parts of Cn. This work we prove that for some odd n ,the class C of 5- cycle in Sn has the property that = An n 7 and C+ has the property that each element of C+ is conjugate to its inverse, the square of each element of it is the element of C-, these results were used to prove that C+ C- = An exceptio
... Show MoreThe subgrade soil is the foundation plate form of the roadway; it should sustain its structural characteristics throughout the design life of the roadway with minimal requirements for maintenance. When Gypseous soil is implemented in the construction of subgrade, problems regarding collapsibility and poor structural capacity usually occur when the subgrade came in touch with excess water. Asphalt stabilization could furnish a proper solution to such problems. In this investigation, an attempt has been made to monitor the variations in compressibility characteristics of asphalt stabilized subgrade soil subjected to 30 cycles of (freezing-thawing) and (heating-cooling). Data have been observed after each 10 cycles, and compared with that of r
... Show MoreA one-dimensional hydraulic model was conducted to simulate the flow in Diyala River. The research aims to study the flow capacity along Diyala River and especially concerning on reach of the river within Baqubah City during flood seasons by using HEC-RAS, 5.07 software. Moreover, specifying the hydraulic problems and then the necessary treatments to overcome them were suggested. A 190 km length of the reach of Diyala River was included in this study, starts from Diyala submerged weir to the confluence of Diyala-Tigris River south of Baghdad City. Good agreement resulted between the measured and the simulation results with a determination coefficient (R2) value of 0.84 with Manning Co
Batch reactive distillation was studied in packed bed column. Esterification of methanol with acetic acid to produce methyl acetate and water with homogenous sulfuric acid as a catalyst was considered. This system was chosen because the reaction is reversible and the boiling point of reactant and products are different.
The reaction was carried out with and without distillation column and shows that the reactive distillation is more efficient from the conventional process (reactor and then separation). The conversion of acetic acid and concentration of methyl acetate increase by (30.43% and 75.14%) respectively at the best condition (reflux ratio 2, feed mole ratio 2 and batch time 90 minute).
The influence of various parameters, s
The region is defined by the spatial dimension, which consists of a set of stabilizers (towns and villages). The concept of the territory requires conditions on the nature of functional relations and the mutual influence of the regions within the region. Any territory must be based on the interdependence and interaction between the mother city and its surrounding countryside and cities, and when the interdependence is strong and the interaction is clear, it helps to define the territory. The regions are divided on different bases. There are geographically or national homogeneous regions, and there are cultural regions that want to preserve their culture in terms of language or religion. There are administrative regions to manage
... Show MoreAl-Huweizah Marsh is considered as the largest in Iraq. This research aims to maintain thesustainability of Al-Huweizah Marsh under all circumstances and within the limits of the
available natural resources from the Iraqi side and the absence of feeding from the Iranian sidedue to the recent Iranian separation dike along the international boundaries within the marsh.
Twelve scenarios have been suggested as a first step to restore the whole marsh. But the
uncontrolled Iranian feeders and exiguity of their discharges recently, it was necessary to studyonly the northern part of the marsh as an alternative case to ensure reasonable amounts of waterfor the purpose of maintaining and restore the marsh. Hydrological routing model was