Because of Cadmium selenide quantum dots (CdSe quantum dots) has a tuning energy gap in the visible light range, therefore; it is provided a simple theoretical model for the absorption coefficient of CdSe quantum dots, where the absorption coefficient determines the extent to which the light of a material can penetrate a specific wavelength before it is absorbed. CdSe quantum dots have an energy gap can be controlled through two effects: the temperature and the dot size of them. It is found that; there is an absorption threshold for each directed wavelength, where CdSe quantum dots begin to absorb the visible spectrum at a size of 1.4 nm at room temperature for a directed wavelength 300 nm. It has been observed that; when the wavelength is increasing its absorption threshold is increased. For wavelengths (400, 500, 600) nm, the absorption thresholds for each quantum sizes are (1.8, 2.2. 3.2)nm respectively. On the other hand, a rising of the temperature led to reduces the absorption coefficient value, that at 400 K for all quantum sizes, the absorption coefficient increases >2000cm−1(According to the directed wavelength) than it is at 0 K. CdSe quantum dots can be considered as one of the most promising materials because it has a tuning gap for the visible wavelengthsfor different applications, such as light-emitting diodes in different colors of the visible spectrum. It is found that; there is a good agreement between our theoretical calculations and experimental results.
The study aimed to show the jurisprudential impact of the multiplicity of directing the syntactic movement of the Qur’anic readings, and it was based on the inductive, descriptive and analytical approach. , such as the difference in explaining the ruling on washing the feet, and the one who meditates on the Qur’anic readings notices in it a picture of the Qur’anic miracles, and this is what is manifested by the brevity of the speech. Collapse the research, and the research tried to trace the Qur’anic readings, contained in the verses, and the readings were limited to what is related to the explanatory meaning mentioned by the commentators, by clarifying the explanatory relationship between the Qur’anic readings and the me
... Show MoreLet M be a n-dimensional manifold. A C1- map f : M M is called transversal if for all m N the graph of fm intersect transversally the diagonal of MM at each point (x,x) such that x is fixed point of fm. We study the minimal set of periods of f(M per (f)), where M has the same homology of the complex projective space and the real projective space. For maps of degree one we study the more general case of (M per (f)) for the class of continuous self-maps, where M has the same homology of the n-dimensional sphere.
As regional development, as a matter of course, poses a number of systemic, scientific and political problems. While the issue of development is primarily at the national level to the limits of World War II in the industrialized world and to the 1960s borders in most Third World countries, the increasing awareness of regional disparities has led to the regional issue Were taken into consideration in the early 1960s and 1970s in most industrialized and developing countries alike. The local issue was only introduced in the early 1980s. The awareness of regional disparities and the fact that the regions do not have the same potential and that some regions have the resources to enable them to develop, grow and develop, unlike other r
... Show MoreIn this paper, the Normality set will be investigated. Then, the study highlights some concepts properties and important results. In addition, it will prove that every operator with normality set has non trivial invariant subspace of .
This work has been done with using of epoxy resin mixed with Granite powder were weighted by percent volume (5,10,15, and 20)%and then mixed with epoxy polymer to compose polymer composite. Hand lay-up technique is used in fabrication of the composite samples. Hardness test was carried out for the proper samples in both normal condition and after immersion in HCL (1 M and 2 M) solutions for periods ranging up to 10 weeks. After comparing the results between the polymer and their composite, the hardness increased with increasing Granite weight percent, it was found that Hardness were greater for the composites before immersion compared with their values after immersion.
The research aims to know the effect of investment risks measured by the beta coefficient on the efficiency of stock pricing measured by the pricing error. The research was applied in the banks listed in the Iraq market for the period (2017-2020). That affects the value of the shares of the companies listed in it and the risks associated with it, as the risks are a dynamic process that changes over time depending on the variables that affect the general development of the economy, so these fluctuations should be taken into account to achieve maximizing returns and reducing risks and what is reflected in stock prices in the Iraqi markets Securities, through which the following question was asked: How does investment risk affect the efficienc
... Show MoreAt atmospheric pressure and at a frequency of 9.1 kHz, a constructed magnetically stabilized tornado gliding arc discharge (MSGAD) system was utilized in this study to generate a non-thermal plasma with an alternating voltage source from 2,4,6,8 to 10 kV. Argon gas was used to generate the arc plasma with an adjustable flow rate using a flow meter regulator to stabilize the gas flow rate to 2 L/min. A gliding plasma discharge is achieved by a magnetic field for the purpose of a planned investigation. The influence of the magnetically stabilized tornado gliding arc discharge parameters such as magnetic field and applied voltage on microscopic tornado plasma parameters was studied. The electron temperature1was measured using a Boltzmann plot
... Show MoreAbstract:
The research aims to define the theoretical framework for corporate governance and its mechanisms and shed light on corporate governance in Iraq as well as the theoretical framework for the quality of financial reports and their relationship and the role of corporate governance in activating them. A commercial bank as a sample for the research, and a survey list was prepared to show the extent to which the research sample banks are committed to applying internal governance mechanisms. imposed on them by the local environment, which leads to improving the quality of financial reports for these banks.