This research aims to study the optical characteristics of semiconductor quantum dots (QDs) composed of CdTe and CdTe/CdSe core-shell structures. It utilizes the refluxed method to synthesize these nanoscale particles and aims to comprehend the growth process by monitoring their optical properties over varied periods of time and pH 12. Specifically, the optical evolution of these QDs is evaluated using photoluminescence (PL) and ultraviolet (UV) spectroscopy. For CdTe QDs, a consistent absorbance and peak intensity increase were observed across the spectrum over time. Conversely, CdTe/CdSe QDs displayed distinctive absorbance and peak intensity variations. These disparities might stem from irregularities in forming selenium (Se) layers around CdTe QDs during growth stages, which could potentially induce quenching in the emission spectrum. The optical examinations unveiled a discernible redshift towards higher wavelength values as the reaction progressed. This spectral shift was coupled with an enlargement in QDs size and a decrease in the energy gap. Using PL and UV analysis techniques enabled a comprehensive study of the optical attributes of the CdTe and CdTe/CdSe QD systems. Our findings underscored the influence of growth conditions and shell materials on the optical properties of QDs. The observed changes in absorbance, peak intensity, wavelength values, QDs size, and energy gap with increasing reaction time provided valuable insights into the growth dynamics of these QD structures.
Abstract
The decision maker needs to understand the strategic environment to be addressed through different means and methods. It is obvious that there is a difference between the three strategic environments (conflict environment, peace environment, post- peace environment) in terms of inputs and strategies to deal with each one of them. There is an urgent need to understand each pattern separately, analyze its inputs, and identify the factors and variables that affect the continuity of this situation (conflict, peace, post-peace). It is not appropriate to identify treatment without diagnosis of the condition, so it is very important to understand the type of strategic environment to be dealt with it.
... Show MoreThe relationship between blood group antigens and peptic ulcer disease has been widely evaluated in the past, but only one study relating H pylori seroprevalence to ABO blood groups among Iraqi patients with peptic ulcer disease is available. We aimed to evaluate the frequency of peptic ulcer disease among different ABO blood groups in Iraqi patients, and we thought it was worthwhile to try to determine whether these components take some part in disease etiology. One hundred and six patients with peptic ulcer disease (PUD) (43 male and 63 female; mean age: 48 ± 18 years) who attended Baghdad teaching hospital and Al- Yarmouk teaching hospital endoscopy centers were enrolled , and 238 control Subjects. Fing
... Show MoreThe present study aimed to asspssment the nutrition a program to sample of student from internal departments of Baghdad University (AL-Jadiriya Complex) and the University of AL-MustanSiriya four grades and aged (19-24) year study included 150 male and female students by (75) male and (75) of female register height, weight nd body mass index were study habits and food pattern of the same sample (150) and by aspecial form and take the personal information interviews and record information on food intake during 24 hour .noted adifference practie in the weights and longths of male and female (sample).
BMI rates were within the normal weight as the value of BMI for males aged (19- 21)and (22-24) and (22.21) and (23,37),respectively and th
The study aimed to measure the concentration of some heavy metal elements and represented by (Pb, Cd,Cu) through the use of atomic absorption spectrometer Flame AAS-7000 type SHIMADZU underwent a process modeling to twelve samples from the soil of electricity Dezlat al Jadiriyah station in the Baghdad University compound at a depth of 30-60 cm from the surface and divided the samples into two groups first included six samples from inside the station while the second included six samples from outside the station. For the element of Pb was higher concentration reached by 29.32ppm and less concentration 17.56ppm. were elements Cd and Cu are growing and less and proportions of certain while the highest concentration of copper 9.69 ppm and le
... Show MoreIn this paper the nuclear structure of some of Si-isotopes namely, 28,32,36,40Si have been studied by calculating the static ground state properties of these isotopes such as charge, proton, neutron and mass densities together with their associated rms radii, neutron skin thicknesses, binding energies, and charge form factors. In performing these investigations, the Skyrme-Hartree-Fock method has been used with different parameterizations; SkM*, S1, S3, SkM, and SkX. The effects of these different parameterizations on the above mentioned properties of the selected isotopes have also been studied so as to specify which of these parameterizations achieves the best agreement between calculated and experimental data. It can be ded
... Show MoreIn this research the Inter-Particle Expectation Values have been studied for atomics Helium (He) and Beryllium (Be) also for He-like ions, Be-like ions (Li-1, B+1? Li+1, Be+2, B+3) by using Hartree-Fock wave functions, We compared the results to some ions which have the same atomic number from each group with atomic number, We compared the results with published calculations to the last studied .
Broadcasting across satellites has become an important media phenomenon and largely available for watchers. As the receiver can see the events at the very moment and at any spot in the world. This study aims to discover the degree of the extent of exposure of Iraqi people to the news broadcasting satellites in Arabic language, (Al Jazeera, Al Arabiya, Al Ekhbariya Satellite Channels) as one of the media that serves the public; and to discover the range of these Satellite Channels in covering the local Iraqi situation in different sides and aspects; and to know the significance of the Iraqi people in watching those news programmers; and state the motives behind the Iraqi public's dependence on these channels.
The
... Show MoreAbstract
Agricultural investment is one of the main requirements in most economies of the world for its importance in the development of the agricultural sector through the agricultural and technological infrastructure and agricultural research, as well as its impact on most economic, social and service activities, especially if managed and employed scientifically, which generates income and productive capacities and services and new commodities, Unemployed as agricultural investments in Iraq fell significantly after 2003 due to economic, political, social