ABSTRACT: Polypyrrole and polypyrrole / silver nanocomposites were fabricated by in-situ polymerization employing Ammonium Persulphate as an oxidizing agent. Nanocomposites were synthesized by combining polypyrrole and silver nanoparticles in various weight percentages (0.1%, 0.5%, 3%, 5% and 7% wt.). Crystallographic data were collected using X-ray diffraction. PPy particles were found to have an orthorhombic symmetry. In contrast, PPy/Ag nanocomposites were reported to have monoclinic structure. The crystallite size was determined by XRD using Scherrer equation and considered to be within 49 nm range. DC conductivity of pelletized samples was evaluated in the temperature range of 323.15k to 453.15k. The conductivity displayed an increase when the temperature is increased from 323.15k to 453.15k. Activation energies were determined from plots of Arrhenius for all nanocomposites. The findings indicated that the activation energy decrease with increasing the weight percentage of Ag nanoparticles in the nanocomposites.
يهتم هذا البحث بدراسة الأجوبة المسكتة,وهي أجوبة سريعة وحاسمة تقطع حجة الخصم وتفحمه وتغلقالحوار.وقد أرتكز البحث على منهجية تداولية تنظرإلى فاعلية الجواب المسكت في المحاورة وإنهائها من زواياإنجازية و حجاجية.وقد تكون البحث من ديباجة ممهدةوثلاثة مباحث.وسلطتالديباجةالممهدةالضوء علىمفهومالجواب المسكتوشيوعهفي كتب الأدبوالأخبارونوادر الكلاموكيف يمكن النظر لهبوصفه وحدة حوارية تنبنيمنها المحادثة؟أما المبحث ا
... Show MoreBelgium is one of the countries that headed towards federalism through a peaceful transition, and over a few decades the country has witnessed deep transformations in its institutions, from a unified and central state in the early nineteenth century to a federal union, regional operations began since 1970 up and constitutionally established its diversity Linguistic and regional, the so -called "state reforms" have been implemented, which led to the emergence of political repercussions. The country has suffered about two decades ago, which caused many national governments that are considered to be among the Luxor in the modern political history of Belgium, However, institutional reforms to achieve the stability of the political system began,
... Show MoreMaxillofacial trauma in females is not widely reported. This study aimed to analyze the clinical characteristics and the patterns of maxillofacial injuries in females and to determine the differences in these patterns among different causes. This retrospective study analyzed several variables, including demographic, social, injury-related, and treatment-related variables, and compared these variables in relation to the main etiologies of maxillofacial trauma. The main etiologies of maxillofacial injuries involving females were assault, followed by road traffic accidents, and falls. There were significant differences in relation to the 3 etiologies in age groups (
Аннотация
В статье считается национально-культурная специфика и языковое изменчивость выражения заключений в художественном тексте. В настоящее время в изучении художественного текста существует множество взаимодополняющих подходов и концепций, которые способствуют лучшему пониманию его языковых и культурных аспектов. Художественный текст как «воспроизведение» и от
... Show MoreInfluence of combined square nozzle with helical tape inserted in a constant heat flux tube on heat transfer enhancement for turbulent airflow for Reynolds number ranging from 7000 to 14500 were investigated experimentally. Three different pitch ratios for square nozzle (PR = 5.8, 7.7 and 11.6) according to three different numbers of square nozzle (N = 3, 4 and 5) and constant pitch ratios for helical tape were used. The results observed that the Nusselt number and friction factor for combination with winglets were found to be up to 33.8 % and 21.4 %, respectively higher than nozzle alone for pitch ratio PR=5.8. The maximum value of thermal performance for using combination with winglets was about 1.351 for pitch ratio= 5.8. Nusselt numb
... Show MoreBiological drugs have an active substance that is made by a living organism or derived from a living organism. They are one of the important therapy options used in a wide range of diseases especially life-threatening diseases. Biological therapy opens new opportunities for treating different diseases for which drug therapy is minimal, but they have considerable differences in the safety consequences in comparison with non-biological drugs. The aim of the current study was to assess the post-marketing safety profile of biological drugs used in Iraqi hospitals by the analysis of the reported adverse drug reactions regarding their severity, seriousness, preventability, expectedness, and outcome. It is a retrospective study of the individu
... Show MoreRacism changes its meaning, shape, purpose or function according to various factors such as time, place, motives, and backgrounds; among others. It seems, however, to have deep roots back in the history of mankind. Such a concept stems from a perceived difference with the other. It is fed by the feeling of being hierarchically superior in opposition to another party that is depicted as inferior. Since ancient times, racism is disguised in different forms and manifests itself on various levels. It is a truism that this ideology can be best presented via language.
Due to its negative implication, racism lends itself to a critical kind of research. As such, this paper is a critical pragmatic investigation for this phenomenon a
... Show MoreIn this paper, the effect of wear in the fluid film journal bearings on the dynamic behavior of rotor bearing system has been studied depending on the analytical driven of dynamic stiffness and damping coefficients of worn journal bearing. The finite element method was used to modeling rotor bearing system. The unbalance response, critical speed and natural frequency of rotor bearing system have been studied to determine the changes in these parameters due to wear. MATLAB software was used to find the analytical values of dynamic coefficients of journal bearing. The results of rotor mounted on fluid film journal bearings showed that the wear in journal bearing increases the amplitude of unbalance response and decrease critical speed, sta
... Show MoreAs a kind of linguistic study, the study of presupposition in drama is one of captivating topic to explore, because of the capability of this topic to make people perceive the presupposition differently. Presupposition is one of the most important concepts in linguistics. It refers to the implicit inferences made in communication between people. These inferences are necessary to understand the utterances correctly. The research particularly endeavors to focus on the linguistic constructions that activate presupposition.