This work characterizes the fractographic features of the neat epoxy and ZrO2 epoxy nanocomposites. All samples were subjected to a tensile test to determine the tensile strength and tensile modulus. SEM images were used to study the morphology of the fractured surface. The fractographic of the fracture surfaces were studied by microstructure analysis program (j-images) to specify the effect of ZrO2 nanoparticles on tensile performance and failure mechanism for ZrO2 epoxy nanocomposites. The tensile test results show that the addition of ZrO2 nanoparticles (2, 4, 6, 8, and 10 vol.%) to the epoxy matrix leads to increase the tensile strength about 40% for optimal content of ZrO2 nanoparticles at 4 vol.%, tensile modules of ZrO2 epoxy nanocomposites increased about 200% for optimal content of ZrO2 nanoparticles at 4 vol.%. SEM images show that the patterns of fractured surfaces of ZrO2 epoxy nanocomposites are different from the pattern of the neat epoxy. The fracture roughness of ZrO2 epoxy nanocomposites increased with the increases of the percentages of ZrO2 nanoparticles, where the increment of fracture roughness about 30% for optimal content of ZrO2 nanoparticles at 4 vol.% can be indicator for the improvement of mechanical properties (tensile strength and modules).
The aim of the present research is to know the following : What are the Science and technology, society and environment issues (S.T.S.E) which included in the content of thechemistry Book second grade intermediate ? And to achieve the objective of search The two researchers has prepares a list of science and technology, society and environment issues (STSE) consisted of (9) key issues namely (Air quality and the atmosphere, sustainable development, water security, health and preventive security, mineral resources investment, pollution of various kinds, energy, food industry, production of weapons technology) and from which (70) sub-issues emerge,Arbitrators competent agreement has been received . Then, thetwo researchers analyzed the con
... Show Moreوفقأ للدراسات السابقة تم تحضير ليكاند آزو جديد (ن-(3-اسيتايل-2-هيدروكسي-5-مثيل-فنيل)ن-(4-كاربوكسي-سايكلوهكسيل مثيل)-ملح الدايازونيوم) وبعد التحقق من الصيغة المقترحة وفق نتائج التحاليل وبعد استخدام الليكاند لتحضير سلسلة ن المعقدات باستخدام نسب مولية متساوية (1:1) من الليكاند وتفاعلها مع كل من املاح المنغنيز والكوبلت والنيكل والنحاس والخارصين وبعد التحقق وفق تقنيات التحاليل الطيفية والتشخيصية(الاشعة فوق البنف
... Show MoreThis systematic review aimed to analyse available evidence to answer two focused questions about the efficacy of erythritol powder air‐polishing (EPAP) (i) as an adjunctive during active periodontal therapy (APT) and (ii) as an alternative to hand/ultrasonic instrumentation during supportive periodontal therapy (SPT). Additionally, microbiological outcomes and patient's comfort/perceptions were assessed as secondary outcomes.
PubMed, Cochrane and Medline were searched for relevant articles published before February 2021 following PRISMA guidelines. The search was conducted by three indep
Background: Odontogenic tumors are a diverse group of lesions with a variety of clinical behavior and histopathologic subtypes, from hamartomatous and benign to malignant. The study aimed to examine the clinical and pathological features of odontogenic tumors in Baghdad over the last 11 years (2011–2021). Materials and Methods: The present retrospective study analyzed all formalin-fixed, paraffin-embedded tissue blocks of patients diagnosed with an odontogenic tumor that were retrieved from archives at a teaching hospital/College of Dentistry in Baghdad University, Iraq, between 2011 and 2021. The diagnosis of each case was confirmed by examining the hematoxylin and eosin stained sections by two expert pathologists. Data from pati
... Show MoreDeveloping and researching antenna designs are analogous to excavating in an undiscovered mine. This paper proposes a multi-band antenna with a new hexagonal ring shape, theoretically designed, developed, and analyzed using a CST before being manufactured. The antenna has undergone six changes to provide the best performance. The results of the surface current distribution and the electric field distribution on the surface of the hexagonal patch were theoretically analyzed and studied. The sequential approach taken to determine the most effective design is logical, and prevents deviation from the work direction. After comparing the six theoretical results, the fifth model proved to be the best for making a prototype. Measured results rep
... Show MoreIn this paper we study the selection of cognitive elements and criteria of the inflectional structure of the Russian and Arabic languages in the process of speech communication. Phonetic-physiological principle is the main parameter by which the elements and criteria of cognitive activity in the presented study are distinguished. On the basis of the above mentioned parameter, we select the investigated criteria and elements. The first criterion is semantic, reflects the accordance of the elements of thinking to sound combinations in the studied languages, and allows us to distinguish the second criterion – morphonological. The second criterion depends on the phonetic changes of these combinations occurring in the process of speech activit
... Show MoreHippuric acid and 3-amino phenol were used to make the 4-(2-Amino-4-hydroxy-phenylazo)-benzoylamino-acetic acid diazonium salt, a new Azo molecule that is a derivative of the (4-Amino-benzoylamino)-acetic acid diazonium salt. We found out what the ligand's chemical structures were by using information from 1HNMR, FTIR, CHN, UV-Vis, LC-mass spectroscopy, and thermal analyses. To make metal complexes of the azo ligand with Co(II), Cu(II), Ru(III), and Rh(III) ions, extra amounts of each azo ligand were mixed with metal chloride salts in a 2:2 mole ratio. The stereochemical structures and geometries of the metal complexes that were studied were guessed based on the fact that the ligand exhibited tetradentate bonding behavior when combined w
... Show MoreA nano manganese dioxide (MnO2) was electrodeposited galvanostatically onto a carbon fiber (CF) surface using the simple method of anodic electrodeposition. The composite electrode was characterized by field emission scanning electron microscopy (FESEM), and X-ray diffraction (XRD). Very few studies investigated the efficiency of this electrode for heavy metals removal, especially chromium. The electrosorption properties of the nano MnO2/CF electrode were examined by removing Cr(VI) ions from aqueous solutions. NaCl concentration, pH, and cell voltage were studied and optimized using the Box-Behnken design (BDD) to investigate their effects and interactions on the electrosorption process. The results showed that the
... Show MoreAbstract: Choosing suitable artificial teeth for partially edentulous patients and arranging these teeth in a way to look natural is difficult. An important factor in dentures construction is the mesiodistal width of anterior teeth, because a denture would not appearance natural if artificial teeth are of incorrect size. While for a successful orthodontic treatment, mesiodeistal width of teeth is important for space analysis and for establishing proper occlusion. The aim of this study is to determine the correlation between the average mesiodistal width of anterior and posterior teeth in male and female Iraqi population. 40 Iraqi subjects with normal occlusion participated in this study. Mesiodistal measurement of all teeth was carried out
... Show MoreThe preparation, spectroscopic characterisation of complexes derived from the mixed ligands with CdII, ZnII and CoII metal ions with Schiff base, Dithiocarbamates (DTCs) and 8-Hydroxyquinoline are reported. The compounds that prepared have been defined via; chloride content, F.T-IR, UV-Vis 1H-NMR spectroscopy and C.H.N.S, as well as conductance and magnetic susceptibility.All data which collected from such methods specified complexes with 6 coordinates in solution and solid states. The biologicalactivity that is related to all the prepared compounds which were screened for their antimicrobial activitiesagainst (G+ and (G- )). The data that collected from biological activity indicate that complexes will have extra activity against such teste
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