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.
Zinc oxide (ZnO) nanostructures were synthesized through the hydrothermal method at various conditions growth times (6,7 and 8 hrs.) and a growth temperature (70, 90, and 100 ºC). The prepared ZnO nanostructure samples were described using scanning electron microscopy (SEM) and X-ray diffractometer to distinguish their surface morphologies and crystal structures. The ZnO samples were confirmed to have the same crystal type, with different densities and dimensions (diameter and length). The obtained ZnO nanostructures were used to manufacture gas sensors for NO2 gas detection. Sensing characteristics for the fabricated sensor to NO2 gas were examined at different operating temperatures (180, 200, 220, and 240) ºC with a low gas concentrati
... Show MoreBackground: Toxin-producing Shiga Escherichia coli has been identified as a new foodborne pathogen that poses a significant health risk to humans. Shiga toxin-producing Escherichia coli can be found in raw cow milk and its derivatives. A small number of Escherichia coli strains that produce shiga toxin are pathogenic. Aim of study: The study aimed to see if there were any virulence genes in 50 milk samples that were typical of Entero-haemorrhagic E. coli and evaluate the Myrtus communis effects on these bacteria. Materials and Method: Milk samples were used to isolate E. coli bacteria (n= 27), biochemically analyzed, and genetically screened for virulence genes using a multiplex (PCR). The hydro-alcoholic extraction of Myrtus communis leave
... Show MoreThis study aimed at some of the criteria used to determine the form of the river basins, and exposed the need to modify some of its limitations. In which, the generalization of the elongation and roundness ratio coefficient criterion was modified, which was set in a range between (0-1). This range goes beyond determining the form of the basin, which gives it an elongated or rounded feature, and the ratio has been modified by making it more detailed and accurate in giving the basin a specific form, not only a general characteristic. So, we reached a standard for each of the basins' forms regarding the results of the elongation and circularity ratios. Thus, circular is (1-0.8), and square is (between 0.8-0.6), the blade or oval form is (0.6-0
... Show MoreThe continuous technical development in the means of communication and information technologies has led to an increase in competition in the provision of service and product on the part of the organizations, as this competition does not know silence and stability on specific methods, but rather it is a world that is constantly moving and renewed in approaches, methods and approaches, and the focus of attention of integrated marketing communications practitioners are Customers, for them, organizations sell their goods, products, services, and ideas, and with them, they become stronger in competition.
This scientific study aimed to identify the trends of the initiators towards the integrated marketing communications of (the Emirates Tel
In this paper, a miniaturized 2 × 2 electro-optic plasmonic Mach– Zehnder switch (MZS) based on metal–polymer–silicon hybrid waveguide is presented. Adiabatic tapers are designed to couple the light between the plasmonic phase shifter, implemented in each of the MZS arms, and the 3-dB input/output directional couplers. For 6 µm-long hybrid plasmonic waveguide supported by JRD1 polymer (r33= 390 pm/V), a π-phase shift voltage of 2 V is obtained. The switch is designed for 1550 nm operation wavelength using COMSOL software and characterizes by 2.3 dB insertion loss, 9.9 fJ/bit power consumption, and 640 GHz operation bandwidth
The study included identification of Leishmania parasites from cases of cutaneous leishmaniasis, by examination of smears for LD bodies , isolation of parasites by culture in media , and characterisation of the isolated parasites by Isoenzyme analysis.Out of 100 cases suspected for cutaneous leishmaniasis ; 85 were diagnosed on culture for Leishmania promastigotes and this method was found to be superior to direct microscopy for amastgotes (LD bodies) .The cases included in this study belonged to different areas of Wasit/Iraq. There were 30 cases from Hay, 35 from Badra, and 35 cases from Suwaira.The distribution of infection in different age groups indi
... Show MoreThe task of an educational institution such as kindergartens need to run by managers possess the knowledge to manage the administration of the importance in the development of kindergarten has been the goal of research to identify knowledge management at Riyadh managers, and achieve the objectives of Search selected sample of directors of kindergartens in the city of Baghdad was (160) director was Akhtarhn simple random way, been building measure for knowledge management and presented to the group of experts and extracted stability in a way re-testing and Alvakronbach and reach search to a discrepancy between managers Riyadh in knowledge management and put the researcher set of recommendations including the establishment of seminars and
... Show MoreThe main objective of this study is to understand the work of the pile caps made of lightweight aerated foam concrete and study the many factors affecting the ability and the capacity of the shear. The study was done by analyzing previous practical and theoretical experiences on the reinforced concrete pile caps. The previous practical results indicated that all specimens failed by shear diagonal compression or tension modes except one specimen that failed flexural-shear mode. Based on test specimens' practical results and behavior, some theoretical methods for estimating the ultimate strength of reinforced concrete pile caps have been recommended, some of which evolved into the design documents available on the subject.
... Show MoreBACKGROUND: Febrile neutropenia occurs in more than 80% of patients with hematological malignances specially after chemotherapy cycles and an infectious source is identified in approximately 20–30%. Various bacterial, viral, and fungal pathogen contribute to the development of neutropenic fever and without prompt antibiotic therapy mortality rate can be as high as 70%. AIM: The objective of the study was to document the current sites of infection in patients with febrile neutropenia in hematological ward in Baghdad Teaching Hospital, the microorganisms and antibiotic susceptibly in culture positive cases and mortality rate in 1 week and 4 weeks after episode of fever. PATIENTS AND METHODS: One hundred cases of febrile neutrop
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