الهدف من الدراسه تحضير فئه جديده من بوليمرات السليكون P1-P4 والتي تمت على اساس استحدام ثنائي مثيل ثنائي كلورو سيلان((DCDMS مع بعض المركبات العضويه التي تحتوي مجاميع الهيدروكسيل الطرفيه والتي حضرت لاول مره M1-M4، بأستخدم البلمره التكثيفيه .كما تم تحضير متراكباتها النانويهP′1-P′4 بوجود جسيمات الفضه النانويه (Ag-NPs) باستخدام طريقة صب المحاليل. شخصت جميع التراكيب للمونمرات والبوليمرات المحضره باستخدام مطيافية FTIR و H1NMR (لبعض البوليمرات) مما سمح بتحديد المجموعات الوظيفية الفعاله للمونومرات وبوليمرات السيليكون. اجريت التحاليل الحراريه الوزنيه TGAوالمسح المسعري التفاضلي DSC لتقييم السلوك الحراري وتاثير وجود جسيمات الفضه النانويهAgNPs .اظهرت نتائج التحليل الحراري ان وجود حلقات الفنيل اظهرت استقرارحراري لبوليمرات السيليكون النقية P1-P4 وان اقحام جسيمات الفضه النانويه بوزن 7 ٪ اظهرت تحسن في الاداء الحراري للمتراكبات النانويه P′1-P′4 مقارنة ببوليمرات السليكون النقيه، ممايعني ان درجة الحراره لفقدان الوزن TGA كانت اعلى لمعظم المتراكبات النانويه P′1-P′4 مقارنة الى بوليمرات السليكون النقيه ، حيث ازدادت درجة الحراره لفقدان الوزن TGA للبوليمر P2 من 127 الى 196 للمتراكبه التانويه P′2 ،وهذا قد بعود الى ملئ الفراغات الحره بين السلاسل البوليمريه بواسطة جسيمات الفضه النانويه .استخدمت تقنية حيود الاشعه السينيه XRD لتشخيص وجود جسيمات الفضة النانويه حيث اظهرت XRD وجود الفضه بحجم نانوي يتراوح بين 20-30 نانوميتر بالاضافه الى دراسة شكل وحجم جسيمات الفضه يتقنية مجهر القوة الذريه وكما تم دراسة مورفولجية السطح باستخدام تقنية مجهر المسح الالكتروني والذي اظهرنوعا ما سطح موحد للمتراكبه النانويه.
In this work the effect of annealing temperature on the structure and the electrical properties of Bi thin films was studied, the Bi films were deposited on glass substrates at room temperature by thermal evaporation technique with thickness (0.4 µm) and rate of deposition equal to 6.66Å/sec, all samples are annealed in a vacuum for one hour. The X-ray diffraction analysis shows that the prepared samples are polycrystalline and it exhibits hexagonal structure. The electrical properties of these films were studied with different annealing temperatures, the d.c conductivity for films decreases from 16.42 ? 10-2 at 343K to 10.11?10-2 (?.cm)-1 at 363K. The electrical activation energies Ea1 and Ea2 increase from 0.031 to 0.049eV and
... Show MoreManganese-zinc ferrite MnxZn1-xFe2O4 (MnZnF) powder was prepared using the sol-gel method. The morphological, structural, and magnetic properties of MnZnF powder were studied using X-ray diffraction (XRD), atomic force microscopy (AFM), energy dispersive X-ray (EDX), field emission-scanning electron microscopes (FE-SEM), and vibrating sample magnetometers (VSM). The XRD results showed that the MnxZn1-xFe2O4 that was formed had a trigonal crystalline structure. AFM results showed that the average diameter of Manganese-Zinc Ferrite is 55.35 nm, indicating that the sample has a nanostructure dimension. The EDX spectrum revealed the presence of transition metals (Mn, Fe, Zn, and O) in Mang
... Show MoreA new hetrocyclic liquid crystal compounds containing 1,3,4-oxadiazole with different substituted in para position (Bromo, Chloro, Nitro and Methyl) were synthesized and characterized by melting points, FTIR Spectroscopy and 1HNMR spectroscopy for [Cl-SR6] and [NO2-SR6] compounds. The liquid crystalline properties of the synthesized compounds were studied by using hot-stage polarizing optical microscopy (POM), so they determined the transition enthalpies and entropies by using differential scanning calorimetery (DSC). All of the compounds show mesomorphic properties. The compounds [Br-SR6], [Cl-SR6] and [NO2SR6] exhibit an enantiotropic dimorphism smectic (Sm) phase, while the compounds [MeSR6] showed nematic (N) phase throw cooli
... Show MoreBackground: Environmental chemicals are thought to
adversely affect human reproductive function.
Objective : To estimate the concentration of cadmium(Cd)
, lead ( Pb ) and Zinc ( Zn ) in serum and seminal plasma
among infertile men .
Methods: A sample of 70 infertile men was investigated.
The relationship of trace elements concentration in serum and
seminal plasma was studied in relation to sperm density,
motility and sperm count.
Results: Except for Zinc the concentration of (Pb) and (Cd)
were generally higher in serum than in seminal plasma. The
mean concentration of (Zn) in seminal plasma was more than
25 times higher than in serum There were no statistical
significant differences observed in the
Human beings have an innate and natural aim to achieve their self-interests and to show their ability to overcome challenges in a better way, therefore the move towards self determination is expressed by intrinsic motivation. The desire of absorbing in this task is to enjoy the task in it self and benefitting from it such a motivation is the desire rooted in human nature to judge and choose in which individual is conscious in his self, abilities and adequacy that help him in control the different situations of life passed by him. His choices and actions are voluntary and non-restricted to intervention or external control because control is inner and subjective, while his behavior is self-regulated with the feeling of
... Show MoreGhrelin and leptin are hunger hormones related to type 2 diabetes mellitus (T2DM), and the pathogenesis of T2DM is the abnormality in insulin secretion and insulin resistance (IR). The aim of this study is to evaluate ghrelin and leptin concentrations in blood and to specify the relationship of these hormones as dependent variables with some biochemical and clinical measurements in T2DM patients. In this study, forty one T2DM and forty three non-diabetes mellitus (non-DM) subjects, aged between 40-60 years and with normal weight, were enrolled. Fasting serum ghrelin and leptin were estimated by enzyme-linked immunosorbent assay (ELISA). In our results ghrelin was significantly increased, and leptin was significantly decreased, in T2DM pa
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