Polyimide/MWCNTs nanocomposites have been fabricated by solution mixing process. In the present study, we have investigated electrical conductivity and dielectric properties of PI/MWCNT nanocomposites in frequency range of 1 kHz to 100 kHz at different MWCNTs concentrations from 0 wt.% to 15 wt.%. It has been observed that the electrical conductivity and dielectric constants are enhanced significantly by several orders of magnitude up to 15 wt.% of MWCNTs content. The electrical conductivity increases as the frequency is increased, which can be attributed to high dislocation density near the interface. The rapid increase in the dielectric constant at a high MWCNTs content can be explained by the formation of a percolative path of the conducting network through the sample for a concentration corresponding to the percolation threshold. The high dielectric constant at a low frequency (1 kHz) is thought to originate from the space charge polarization mechanism. I-V characteristics of these devices indicate a significant increase in current with an increase in multi-walled carbon nanotube concentration in the composites. The SEM images show improved dispersion of MWCNTs in the PI matrix; this is due to the strong interfacial interactions.
The normalized difference vegetation index (NDVI) is an effective graphical indicator that can be used to analyze remote sensing measurements using a space platform, in order to investigate the trend of the live green vegetation in the observed target. In this research, the change detection of vegetation in Babylon city was done by tracing the NDVI factor for temporal Landsat satellite images. These images were used and utilized in two different terms: in March 19th in 2015 and March 5th in 2020. The Arc-GIS program ver. 10.7 was adopted to analyze the collected data. The final results indicate a spatial variation in the (NDVI), where it increases from (1666.91 𝑘𝑚2) in 2015 to (1697.01 𝑘𝑚2)) in 2020 between the t
... Show MoreBackground: Adolescence is one of the most dynamic stages of human development. However, Oral health is an integral part of public health, significantly impacts on the quality of life. OHE program is an important issue that should be given to them. The aim of this study was to evaluate oral health outcomes on adolescents' oral health by teachers and mothers Materials and Methods: The study was carried out in seven schools of Diyala - Baquba city. This 14-weeks duration study assessed the effectiveness of school OHE program on oral hygiene status, gingival health, and halitosis assessment of 80, 12 year-old, both genders of school adolescents. From the selected schools, one group was supervised by the teachers and the other was supervised
... Show MoreA simple indirect spectrophotometric method for determination of mebendazol in pure and pharmaceutical formulation was presented in this study. UV-Visible spectrophotometry using the optimal conditions was developed for determination of mebendazole in pure drug and different preparation samples. The method is based on the oxidation of drug by nbromosuccinimide with hydrochloric acid and the left amount of oxidizing agent was determined by the reaction with tartarazine and the absorbance was measured at 428 nm. Calibration curves were linear in the range of 5 to 30 µg.mL-1 with molar absorptivity 8437.2 L.mol-1 .cm-1 . The limits of detection and quantification were determined and found to be 0.7770 µg.mL-1 and 2.3400 µg.mL-1 respec
... Show MoreIn the field of civil engineering, the adoption and use of Falling Weight Deflectometers (FWDs) is seen as a response to the ever changing and technology-driven world. Specifically, FWDs refer to devices that aid in evaluating the physical properties of a pavement. This paper has assessed the concepts of data processing, storage, and analysis via FWDs. The device has been found to play an important role in enabling the operators and field practitioners to understand vertical deflection responses upon subjecting pavements to impulse loads. In turn, the resultant data and its analysis outcomes lead to the backcalculation of the state of stiffness, with initial analyses of the deflection bowl occurring in conjunction with the measured or assum
... Show Moretotal of 17 Escherichia coli isolates were collected from urine specimens of patients with urinary tract infection. Antibiotics sensitivity test indicated that amikacin followed by chloramphenicol and ciprofloxacin are the most effective antibiotics. The isolates showed multidruge resistant, nine isolates were resistant to 11-15 antibiotics, 3 were resistant to 16-20 antibiotics and 5 were resistant to 21-25 antibiotic. Two isolates were selected, the first (ED1) was resistant to (22) antibiotics while the second isolate (ED2) was resistant to (14) antibiotics (out of 25). Minimum inhibitory concentration (MIC) of the black and green tea water boiled extracts were determined towards (ED1,ED2).Results showed that MIC of black tea extr
... Show MoreThis paper presents a hybrid genetic algorithm (hGA) for optimizing the maximum likelihood function ln(L(phi(1),theta(1)))of the mixed model ARMA(1,1). The presented hybrid genetic algorithm (hGA) couples two processes: the canonical genetic algorithm (cGA) composed of three main steps: selection, local recombination and mutation, with the local search algorithm represent by steepest descent algorithm (sDA) which is defined by three basic parameters: frequency, probability, and number of local search iterations. The experimental design is based on simulating the cGA, hGA, and sDA algorithms with different values of model parameters, and sample size(n). The study contains comparison among these algorithms depending on MSE value. One can conc
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