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.
This study aimed to identify the degree of frustration and guilt among addicts who hurt themselves with drug, and to know the addicts perspective who are in treatment clinics and rehabilitation centers in Palestine, in order to achieve this goal aDeterminationThe study population has been identified , this study population consisted of ' (82) addict, the researcher used the descriptive analytical method which is appropriate for this study, so the researcher questioned the addicts who are in treatment clinics and rehabilitation centers in Palestine and analyze their responses in light of some of the variables.
The study results showed that drug addicts who ar
... Show MoreBiodiversity, biological diversity, biological diversity, biological diversity, biological diversity, biological diversity, biological diversity (by developmental factors) environmental factors and environmental factors environmental factors and environmental factors and environmental factors Correlation between biology and the succession of geological and historical factors of living organisms and geological and historical factors to the site and what It is surrounded by natural and tourist attractions and the pursuit of scientific methods in order to advance the studies of biological diversity in the region .
In the current study, haemoglobin analytes dissolved in a special buffer (KH2PO4(1M), K2HPO4(1M)) with pH of 7.4 were used to record absorption spectra measurements with a range of concentrations from (10-8 to 10-9) M and an absorption peak of 440nm using Broadband Cavity Enhanced Absorption Spectroscopy (BBCEAS) which is considered a simple, low cost, and robust setup. The principle work of this technique depends on the multiple reflections between the light source, which is represented by the Light Emitting Diode 3 W, and the detector, which is represented by the Avantes spectrophotomer. The optical cavity includes two high reflectivity ≥99% dielectric mirrors (dia
... Show MoreBased on a finite element analysis using Matlab coding, eigenvalue problem has been formulated and solved for the buckling analysis of non-prismatic columns. Different numbers of elements per column length have been used to assess the rate of convergence for the model. Then the proposed model has been used to determine the critical buckling load factor () for the idealized supported columns based on the comparison of their buckling loads with the corresponding hinge supported columns . Finally in this study the critical buckling factor () under end force (P) increases by about 3.71% with the tapered ratio increment of 10% for different end supported columns and the relationship between normalized critical load and slenderness ratio was g
... Show MoreThe study aims to identify the level of existential frustration and the level of recrimination among the students of universities, identify the statistical differences between the existential frustration and recrimination based on gender, and finally, identify the correlation between the existential frustration and recrimination. To do this, the researcher adopted the existential frustration scale of ( al-saaedi, 2009) that consisted of (43) item, he also adopted the recrimination scale of ( al-zugeibi,2008) which composed of (31) item. The total sample was (120) male and female student were chosen randomly from four colleges within the university of Baghdad for the academic year ( 2015-2016). The results revealed that the targeted sampl
... Show MoreInformation about soil consolidation is essential in geotechnical design. Because of the time and expense involved in performing consolidation tests, equations are required to estimate compression index from soil index properties. Although many empirical equations concerning soil properties have been proposed, such equations may not be appropriate for local situations. The aim of this study is to investigate the consolidation and physical properties of the cohesive soil. Artificial Neural Network (ANN) has been adapted in this investigation to predict the compression index and compression ratio using basic index properties. One hundred and ninety five consolidation results for soils tested at different construction sites
... Show MoreThe study aims to identify the Traumatic Symptoms (physiological, emotional, and cognitive) of earthquakes among the targeted sample; it also aims to identify the significant differences between psychological, emotional, and cognitive traumatic symptoms of earthquakes according to the gender and age of participants. The study additionally seeks to identify thepsychological positive-negative reactions associated with earthquakes according to gender and age of the participants. To measure the traumatic symptoms of earthquakes, a 4-point Likert scale questionnaire with (20) items (questions) accompanied with a 4-point Likert scale questionnaire with (18) items (questions) were used to measure the Psychological positive-n
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