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.
The oxidative degradation of Orange G dye by nanosized CeO2 catalyst has been performed in this study. The catalyst was prepared by precipitation method. Various characterization techniques were carried out to study the physical and chemical properties of the synthesized catalyst. The XRD result confirms well the formation of CeO2 cubic phase. The FTIR result showed the effect of calcination temperature for CeO2 was clearly observed due to reduction in band intensity compared to uncalcined Ce nitrate sample. Meanwhile, the diffused reflection spectra recorded reflection spectra at 414 nm with an energy gap of 3.2 ev. The decolorization of Orange G dye by oxidation process were carried out unde
... Show MoreDifferent cooking conditions were examined for aluminum content in food cooked while wrapped with aluminum foil. The influence of each anticipated factor (the acidity of the cooking medium, type of acids normally used in cuisines namely acetic and tartaric acids, various cooking temperatures, influence of the presence of sodium chloride salt, the effect of cooking oil, and the length of time of cooking) was studied thoroughly as a function of aluminum degraded out of the aluminum foils to the medium. The experimental samples were digested with nitric acid upon fulfillment of examining each factor separately before quantifying aluminum with the sensitive technique of atomic absorption spectroscopy. The outcomes of the study have shown that t
... Show MoreThe electoral poster is the most important means and methods of the electoral campaign because of its advantages and capabilities if it is organized properly. It is an intensive propaganda message with psychological figures and semiotic connotations belonging to sub-culture. Its construction depends on a group of elements (logo, photo symbols, color and picture) and their consistency is varying from one to another. Posters must be committed the determinants of attraction, excitement, simplicity and clarity. They are working according to the following base: (fixed audience X moved recipients) and walking towards (moving X moving) due to the technical development of optical screens. These developments require double the force of the impact
... Show MoreObjective. This study aimed to evaluate and compare the force degradation of two types of elastomeric chains following different periods of immersion in zinc-containing mouthwashes. Materials and Methods. Four hundred and forty pieces of Elasto-Force and Super Elasto-Force elastomeric chains were divided into two control and eight experimental groups. The pieces were stretched to 25 mm on pins mounted on an acrylic block and stored in distilled water at 37°C. The experimental groups were immersed in four different types of mouthwash for one minute twice a day throughout the test period. Ten continuous thermocycles per day between cold and hot water baths (5–55°C) were carried out. Forces were measured at six-time intervals (in
... Show MoreThis research presents a statistical study of radiation generated from communication towers in the Nineveh Plain region Baghdeda. The intensity of radiation energy was measured at 10 meters away from the communication tower in different locations, using a (1PC XH-901 Dosimeter/ Personal Dose Alarm / Radiation Detector, dosage rate: 0.01 μSv/h to 150μSv/h) to measure the amount of radiation at various times. Energy densities were measured and compared with standard limits provided by other authorities, such as the International Committee for Radiation Protection. Results were analyzed using SPSS version 26 to implement the data. The results show that the means of the radiation levels measured at all the zones do not statistically differ
... Show MoreOur research is based on the fact that the reflection of entertainment programs in Arab satellite channels on the social behavior of Iraqi youth … a field analysis of the Arab ldol program) and that its importance is the entertainment programs and their reflection on social behavior، which occupies
large areas of time from Satellite channels in the form of various episodes and each episode contains several categories، or in the form of templates and forms of various goals and contents، but the problem of
research boils down to (how far iraqi youth follow the entertainment programs in Arab satellite channels and what are the motives for watching the Program Arab ldol )) by For Iraqi youth and what are the positive and negative
The research aims to formulate a model for research on the dimensions of the Leader-member exchange theory according to the ideas and thoughts of Liden /Maslyn, Hammer and impact on job satisfaction and measure these dimensions at asiacell communications to identify the extent of convergence between theoretical dimensions share leader – member Exchange (LMX) with leadership style used in this company, we have been building scale contains two variables, independent variable Leader-member exchange theory five dimensions (effect , Loyalty, contribution, respect professional, and support) the certified job satisfaction variable dimensions (job security, The Style of management, organizational climate, appreciation, and work itself)
... Show MoreRole of public relations (PR) and from one community to another, depending on the different cultures of these societies in General, and different ethical values established by their practitioners in these communities organizations , public relations in developed societies, and in some developing countries have taken great strides to contribute to the strategic planning and decision-making, in the framework of their commitment to the values and ethical standards for practitioners, In contrast, we find that applied in Iraq still skips phase coordinate with different communication means with the aim of advertising and publicity for the organization. As a result of the limited recognition of the strategic and vital
... Show MoreBackground: EBV infection in tissue micro-environment is challenged by the precisely regulated survivaland apoptosis mechanisms. Abnormal bcl-2 proto-oncogene expression in colonic carcinomas allowsaccumulation and propagation of these genetically altered cells.Objective: To analyze the relevant concordance of BCL-2 gene , EBNA1 s and LMP-1-EBV expression inissues from a group of Iraqi patients with colonic adenocarcinomas.Patients and Methods: One hundred (100) tissue biopsies, belonged to (40) patients with colorectalcancers, (40) patients with benign colon tumors, and (20) apparently normal colorectal control tissues,were enrolled in this study. The detection of EBNA1 s and LMP-1-EBV as well as BCL-2 was done byimmunohistochemist
... Show MoreThe research aims to determine the impact of employees’ retention strategy on organizational memory. This research is historical, descriptive, and analytical. The sample consists of 158 faculty members in five private colleges in Baghdad. The technique used to analyze the data is SEM (Structural Equation Modeling), and SPSS (Statistical Package for the Social Sciences). The research concludes that the employees retaining strategy plays a vital role in retaining employees and hence maintains organizational memory. The findings and recommendations of this research assure the administrations of private colleges that employees retention strategy play a vital role in retaining its employee and hence maintains organizational memory. T
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