Experimental investigations had been done in this research to demonstrate the effect of carbon fiber and Ceramic fillers contents on the tribological behaviour of (15% volume fraction) carbon-epoxy composite system under varying volume fraction, load, time and sliding distance. The wear resistance were investigated according to ASTM G99-05standard using pin on disc machine to present the composite tribological behaviour. The influence of three ceramic fillers, granite, perlite and calcium carbonate (CaCO3), on the wear of the carbon fabric reinforced epoxy composites under dry sliding conditions has been investigated. The effect of variants in volume fraction, applied load, time and sliding distance on the wear behaviour of polymer composites is studied by measuring the weight changes . In the experiments with wear test pin having flat face in contact with hardening rotating steel disc, sliding speed, time and loads in the range of 200 RPM, 300–900s and 40–60 N respectively was used. It is observed that the wear resistance increase with the increasing of reinforcement material volume fraction while, the wear rate increases with increasing of applied load, time and sliding distance. The results showed that the filler of granite perlite and CaCO3 as filler materials in carbon epoxy composites will increase the wear resistance of the composite greatly than carbon fiber fillers epoxy composite only and granite filled CE Composite exhibited the maximum wear resistance.
Bigheaded carps (bighead carp, Hypophthalmichthys molitrix, and silver carp, Hypophthalmichthys nobilis) and their hybrids play an important ecological and economic role in their original habitat, while their introduced stocks may pose serious ecological risks. To address questions about the persistence and invasiveness of these fish, we need to better understand their population structures. The genetic structures of bigheaded carp populations inhabiting Lake Balaton and the Tisza River were examined with ten microsatellite markers and a mitochondrial DNA marker (COI). The Lake Balaton stock showed higher genetic diversity compared with the Tisza River stock. Based on hierarchical clustering, the Tisza population was characterized o
... Show MoreFor more than seven decades, the Palestinian-Israeli conflict has not ended, and every one claims his right to the land, waters, airspace and wealth of Palestine. This conflict was reflected in the political, military, social and cultural aspects, and the cinema had a prominent role in conveying messages to the world about this conflict. On the geopolitical dimensions and their impact on the cinematic image in the films of the Palestinian cause), the researchers divided the research into four frameworks that came as follows: (methodological framework) and included the research problem, its importance, research objectives, research limits and sealing the chapter by defining the terms. And (theoretical framework): it was divided into two s
... Show MoreThis Study presents and provides Variable thoughts and aspects for representing Scientific topics " Physics for instance " as Play Shows for high School Students, by Showing a suggested Method that will Contribute in illustrating the Steps of writing the educational Scientific topic, and this method will help teachers to deliver their message to the Students " receivers " easily.The researcher have used Puppets in this method as the assisting tool for teachers, to help them deliver message Clearlym easily and Joyful.The researcher in his experiment used " Archimedes Principle " as a typical example, by Converting it into a theatrical Script, with respect to the Concept of Science, and in accordance to the Scientific educational Curriculu
... Show MoreOur aim was to investigate the changes in the myocardium stiffness index for patients suffering from systemic hypertension, and to assess their left ventricular performance. We studied 263 hypertensive patients and 166 healthy subjects as a control group. By using conventional Doppler echocardiography, the following parameters were measured—Left ventricular end diastolic diameter, left ventricular end systolic diameter, transmitral early velocity, isovolumic relaxation time, and isovolumic contraction time. Tissue Doppler imaging (TDI) was used in the measurements of the early mitral annular velocity (Ea) and the diastolic stiffness was obtained by calculating the ratio E\Ea\LVIDd. Index myocardial performance (IMP) was calculated
... Show MoreThis paper has dealing with experimentally works which includes properties of materials and testing program. The testing program includes rotine characterization tests, chemical, and physical tests for samples of gypseous soil. Samples of disturbed and undisturbed soil was obtained of seven different locations of Salah-Aldeen province. The unified classification system was adopted of study region. Except sample 7, soil categorization (as poorly graded sand) was a good graded sand soil. Samples had non plasticity rate (NP). The results of laboratory tests (by using Arc-Map GIS program) were enhanced by spatial interpolation mapping utilizing Inverse Distance Weighted Scheme.
Relying on modern work strategies, such as adopting scientific inductions, consolidates the information in the learner’s memory, develops the skill work of the football player, and raises the efficiency of their motor abilities. From this standpoint, the researcher, who is a teacher at the University of Baghdad, College of Physical Education and Sports Sciences, and follows most of the sports club teams in youth football, believes that there must be From extrapolations through the machine and employing it in the field to serve the skill aspect and benefit from scientific technology in development and making it a useful tool to serve the sports field in football, as the goal of the research was the efficiency of machine extrapolation in de
... Show MoreThis study was based on the determination of aphid species that infested Chrysanthemum sp. (Asterales, Asteraceae) in the middle of Iraq; five aphid species belong to subfamily Aphidinae were recorded: Aphis fabae Scopoli, 1763, Aphis gossypii Glover, 1877, Coloradoa rufomaculata (Wilson, 1908), Macrosiphoniella sanborni (Gillette, 1908) and Myzus persicae (Sulzer, 1776). A. gossypii was the most dominant species throughout the study period while M. persicae is the lesser species.
A summary of the main taxonomic characters is presented here and a pictorial key which was designed to separate aphi
... Show MoreObjective(s): The present study aims at identifying the Iraqi Colleges of Nursing Deans' leadership
behaviors effectiveness and faculty members' motivation towards work in these colleges.
Methodology: Descriptive design has been used for the sample survey manner, which is the
appropriate approach to the study of social phenomena in the field where provides data on the reality of
these phenomena and relations between the causes and consequences and an analysis of it and perhaps
the factors affecting it and how it appears. The study relies on a questionnaire to collect data from the
participants which is composed of (86) items distributed on three axes: First, the demographic
characteristics which are composed of (8) i
In parallel with the shell model using the harmonic oscillator's single-particle wave functions, the Hartree-Fock approximation was also used to calculate the neutron skin thickness, the mirror charge radii, and the differences in proton radii for 13O-13B and 13N-13C mirror nuclei. The calculations were done for both mirror nuclei in the psdpn model space. Depending on the type of potential used, the calculated values of skin thickness are affected. The symmetry energy and the symmetry energy's slope at nuclear saturation density were also determined, and the ratio of the density to the saturation density of nuclear matter and the symmetry energy has a nearly linear correlation. The mirror ener
... Show MoreAbstract
Binary logistic regression model used in data classification and it is the strongest most flexible tool in study cases variable response binary when compared to linear regression. In this research, some classic methods were used to estimate parameters binary logistic regression model, included the maximum likelihood method, minimum chi-square method, weighted least squares, with bayes estimation , to choose the best method of estimation by default values to estimate parameters according two different models of general linear regression models ,and different s
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