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.
Introduction: The study was intended for Roseomonas gilardii NTCC 13290 strain pigment extraction and characterization. Methodology: The pigment-producing bacterial were cultured on Columbia blood agar and nutrient media agar. Then the pigments were extracted by ethanol. The candidate pigment was further characterized by different biotechnological techniques: UV-Vis spectroscopy, FT-IR to analyze the functional group of the targeted pigment, and TLC media. Results: The cultivation of Roseomonas gilardii on media showed pink color and nearly runny texture. The bacterial colonies were microscopically gram stained and examined, the R. gilardii was seen as coccobacillus colonies that mostly form pairs arranged as short chains. The R. gilardii b
... Show MoreThe childhood of the most important stages throughout the human and which have been more vulnerable to various factors surrounding it and with the scientific and cognitive development in all fields surfaced many psychological phenomena that play a large role in influencing children and their behavior trends is the susceptibility of the lure of psychological phenomena which plays a major role in the social attitudes of individuals it may not be predictable so that individuals vary in between them in terms of vulnerability Balasthoa You do this only _bl that the same individual at different influenced Balasthoa different depending on the positions and this was research to achieve its objectives and that are known:
_ alasthoa The childre
With the increasing rate of unauthorized access and attacks, security of confidential data is of utmost importance. While Cryptography only encrypts the data, but as the communication takes place in presence of third parties, so the encrypted text can be decrypted and can easily be destroyed. Steganography, on the other hand, hides the confidential data in some cover source such that the existence of the data is also hidden which do not arouse suspicion regarding the communication taking place between two parties. This paper presents to provide the transfer of secret data embedded into master file (cover-image) to obtain new image (stego-image), which is practically indistinguishable from the original image, so that other than the indeed us
... Show MoreAugust Wilson’s major concern is to communicate the African American cultural awareness; to establish a counter-culture based on self-confidence and assertiveness. He advocates an encouraging attitude to elevate the African Americans’ spiritual consciousness and to teach them how to sublimate their aims in life. He aspires to win the everlasting battle against racial discrimination, oppression, injustice, and identity confusion. Sublimation, as a defense mechanism, will be Wilson’s new ammunition to re-read and to re-interpret the psychic constitution of his people, to help them get out of their self-imposed fences and this is the core of Wilson’s new culture. Sublimation is the process in which the psyche directs the negative drive
... Show MoreThe topic of supra.topological.spaces considered one of the important topics because it is a generalization to topological.spaces. Many researchers have presented generalizations to supra open sets such as supra semi.open and supra pre.open sets and others. In this paper, the concept of δ∼open sets was employed and introduced in to the concept of supra topology and a new type of open set was extracted, which was named S∼δ∼open. Our research entails the utilization of this category of sets to form a new concepts in these spaces, namely S∼δ∼limit points and S∼δ∼derive points, and examining its relationship with S∼open and S∼reg∼open. Based on this class of sets, we have introduced other new concepts such as S∼isolate
... Show MoreThe present study was designed to evaluate the immunological status in a sample of Iraqi males with primary infertility and them age range18-55 years, who were attending the Centre of Infertility and in vitro Fertilization (Kamal Al-Samaraie Hospital, Baghdad) during the period December 2008 – April 2009. They were divided into three groups; 40 patients with anti-sperm antibodies (ASA), 20 patients with Asthenozoospermia (AST) and 20 patients with azoospermia (AZO). In adition to20 fertile males was as control group. The parameters of evaluations were standard seminal fluid analysis, anti-sperm antibodies and anti-mitochondrial antibodies in serum, Therefore, two types of samples were collected from each subject; seminal fluid and blood.
... Show MoreIn the South of yement, when the accupation of Aden in 1839 by the British, British politics has proceeded in accordance with interests in promoting the existence and exploitation of this important site to implement their interests. Historians believe that Britain played a major role in the conflicts that have taken place on the land of Yemen, through a series of military and political dealings between them and the Ottoman Empire prior to withdrawal of Yemen and between local authorities and power to Yemen, such interactions have led to very serious consequences for the future of Yemen and Yemen was often divided into three parts, the northern areas under the authority of Imam Yahya, and the South, under the control of Britain, Asir and
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