The research involves preparing gold nanoparticles (AuNPs) and studying the factors that influence the shape, sizes and distribution ratio of the prepared particles according to Turkevich method. These factors include (reaction temperature, initial heating, concentration of gold ions, concentration and quantity of added citrate, reaction time and order of reactant addition). Gold nanoparticles prepared were characterized by the following measurements: UV-Visible spectroscopy, X-ray diffraction and scanning electron microscopy. The average size of gold nanoparticles was formed in the range (20 -35) nm. The amount of added citrate was changed and studied. In addition, the concentration of added gold ions was changed and the calibration curve was calculated used to estimate Au ions in different samples. The effectiveness of gold nanoparticles prepared according to Turkevich method was studied as antibacterial agents against E. coli bacteria. The minimum inhibition concentration of gold nanoparticles that inhibit bacterial growth was calculated using the broth dilution method, which is based on several dilutions to determine the inhibition concentration.
Background: Brush cytology is an accepted technique that gets renewed interest. It is now used as an aid for the diagnosis and observation of possible epithelial changes that could be associated with oral mucosal diseases. This study aimed to evaluate the cytomorphometric changes in gingiva and buccal mucosa of type II diabetics and to assess their relation to oral symptoms and glycemic status. Materials and methods: Cytological Papanicolaou stained smear were prepared from cheek and gingiva of 20 non treated cases, 20 treated diabetics and 20 healthy persons of both sex after measuring their HbA1c and recording their oral symptoms. Hundred unfolded epithelial cells were evaluated qualitatively using MCID software to measure nuclear and cy
... Show MoreRG Majeed, AS Ahmed, Jornal of Al-Muthanna for Agricultural Sciences, 2023
This study aims to find out the effectiveness of instructional scaffolding strategy in the development of academic achievement and critical thinking of female second grade secondary mathematics students. Semi-experimental and relational descriptive method was used. The sample of the study consisted of (50) students divided into an experimental group and a control group. The experimental group was taught using scaffolding strategy whereas the control group was taught using traditional method. Pre- and Post-tests were used to achieve the objective of the study. The results of the study revealed that there are statistically significant differences in the mean scores of the experimental and control groups in the posttest for both the academi
... Show MoreThe Risks Faced by Britain in their Areas of Influence at the Beginning of the Twentieth Century Drove her to the Alliance with the State of European such as France, and Contributed to the Tireless and made by the British and French Politicians in the Consolidation of Friendly Relations between the two Countries Efforts and Strengthened Cooperation in a Positive Way to Visit the king of Britain's Edward VII to France, Offset by Visit French President Loubet to Britain in the Same Year, those Negotiations Bore Fruit between the two Countries for Reaching a Contract Arbitration and Decisiveness between Britain and France Treaty on the Fourteenth of November 1903, Promised that Treaty First Step that Paved the Way for a General Agreement be
... Show MoreIt is shown that pure and 3% boron doped a-Si0.1Ge0.9:H and a-Si0.1Ge0.9:N thin films
could be prepared by flash evaporation processes. The hydrogenation and nitrogenation
are very successful in situ after depositing the films. The FT-IR analysis gave all the
known absorbing bonds of hydrogen and nitrogen with Si and Ge.
Our data showed a considerable effect of annealing temperature on the structural and
optical properties of the prepared films. The optical energy gap (Eopt.) of a-Si0.1Ge0.9
samples showed to have significant increase with annealing temperature (Ta) also the
refractive index and the real part of dielectric constant increases with Ta, however the
extinction coefficient and imaginary part of dielect
Abstract Portable communication devices such as WLAN, WiMAX, LTE, ISM, and 5G utilize one or more of the triple bands at (2.32.7 GHz,3.4–3.6GHz,and5–6GHz)andsufferfromtheeffectofmultipathproblemsbecausetheyareusedinurbanregions.To date, no one has performed a review of the antennas used for these types of wireless communications. This study reviewed two types of microstrip antennas (slot and fractal) that have been reported by researchers (as a single element) using a survey that included the evaluation of several important specifications of the antennas in previous research, such as operating bandwidth, gain, efficiency, axial ratio bandwidth (ARBW), and size. The weaknesses in the design of all antennas were carefully identified to de
... Show MoreMultiple linear regressions are concerned with studying and analyzing the relationship between the dependent variable and a set of explanatory variables. From this relationship the values of variables are predicted. In this paper the multiple linear regression model and three covariates were studied in the presence of the problem of auto-correlation of errors when the random error distributed the distribution of exponential. Three methods were compared (general least squares, M robust, and Laplace robust method). We have employed the simulation studies and calculated the statistical standard mean squares error with sample sizes (15, 30, 60, 100). Further we applied the best method on the real experiment data representing the varieties of
... Show MoreOne of most the important compounds which have active hydrogen (substrate) is the thiols which used in a wide field in preparation of Mannich bases . A large number of Mannich bases have been prepared as a biologically active compound (pharmaceutical, pesticides, bactericidal, fungicidal and tuberculostatic) and in order to correlate their structure and reactivity with their pharmacological activity such as . It has been reported that the reaction is easily proceeded by using primary and secondary amine beside formaldehyde. But when we tried the reaction of thiols as substrate and formaldehyde and succinimide instead of amine, the reaction did not proceed to give Mannich base but product were methylenene – bis – sulfide . Mann
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