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.
Old New York was Wharton's term to describe this wealthy and elite class at the top of
the developing city's social hierarchy, a society which was utterly intent on maintaining its
own rigid stability. Even though, the roles of women in American society changed drastically
from 1820’s to 1860’s due to the civil war and such a progression was due in part to the
revolutionary thoughts. Women started taking their right to speak up openly and frankly and
become more like men. The role of many women had changed from being homemaker to
being able to provide for the family by either getting a job or start to be allowed to have a
voice. They had important roles not only in helping the family, but in sharing to rebuild th
Academic Buoyancy of High School students at the Distinguished Schools
The study aimed to get acquainted with kindergarten teachers in the development of
emotional intelligence in children, To achieve this a study too, which consisted of 40 items,
within four areas was condncted: (managing emotions, emotional knowledge, empathy, social
networking) The study tool was applied to the sample amounting (200) teachers of the
kindergarten teachers in the province of Jerash and after analyzing the results statistically
using arithmetic averages standard deviations and variance analysis quartet the following
results were reached :
- presence of statistically significant differences at the level of (α =0,05) is attributable to the
impact of the educational level in the areas of empathy and so
Logic in the philosophy of ethical behavior in business organizations
In this study, some attenuation parameters of gamma shields were studied. This shields consisting of composite materials of Unsaturated polyester as a base material and Nano iron oxide (Fe2O3) and, micro iron (Fe) as reinforcement materials at different percentages (1, 3,5,7and 9)wt%, and with different thickness (1, 1.5, 2, 2.5, 3, 3.5and 4) cm. The results showed that the use of nanoparticles is better than the microparticales in the field of radiation shielding. It has been shown that the values of attenuation parameters of gamma it bitter in the case of nanoparticles than case of the use of micro material.
Alkaloids are a group of naturally occurring chemical compounds that contain mostly basic nitrogen atoms . They are a large family of compounds synthesized by plants in addition to the bacteria, fungi, and animals, they often have pharmacological effects. The aim of this study is to isolate and identified alkaloids in a newly studied, wild Iraqi plant named
... Show MoreDestiny functional theory (DFT) calculations are undertaken in order to scrutinize the electrochemical and calcium (Ca) storage characteristics of a graphyne-like aluminum nitride monolayer (G-AlNyen) as an electrode material for Ca-ion batteries (CIBs). The results show that the change in internal energy as well as the cell voltage values for the CIB with the G-AlNyen anode are comparable to others with two-dimensional 2D nano-materials. It is shown that Ca is adsorbed primarily onto the center of a hexagonal and triangular ring of G-AlNyen with absorption energies of −2.06 and −0.42 eV. After increasing the concentration of Ca atoms on G-AlNyen, the adsorption energy as well as the cell voltage decreases. Lower values of 0.15–0.32 e
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