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.
The aim of this study is to develop the science textbook for the 1st intermediate grade by analyzing it according to life skills. Its core areas were mental skills, environmental skills, and health skills. The analysis tool was used after verifying its validity and stability in analyzing the science textbook for the 1st intermediate grade, and the results of the study resulted in the inclusion of mental skills on a high percentage of repetitions, while we find that this percentage is low in the inclusion of environmental and health skills. The study recommended the importance of achieving balance and justice in including skills in the science textbook for the 1st intermediate grade, by emphasizing the environmental and health skills by incr
... Show MoreEducation specialists have differed about determining the best ways to detect the
talented. Since the appearance of the mental and psychological measurement movement, some
scholars adopted intelligence ratios as a criterion to identify the talented and others went to
rely on the degree of academic achievement. Each of these two methods has its own flaws and
mistakes and a large number of talented children were victims of these two methods.
Therefore the need to use other scales for the purpose of detection of talented children
appeared because they provide valuable information which may not be obtained easily
through objective tests and these scales are derived from consecutive studies of gifted andtalented children
Objectives: The study intends to identify the sources of work-related stress that might face the nurses working at
psychiatric wards in Baghdad psychiatric hospitals and to find out a relationship between the levels of stress and
some demographic characteristics.
Methodology: A descriptive study was achieved from the 10th of December, 2013 through the 10th of March, 2014.
Non-probability purposive samples of 94 nurses who work in psychiatric wards of Baghdad psychiatric hospitals
were recruited to meet the study objectives. Psychological Stress Inventory (PSI) the Arabic version, which was
modified by Abu Al-Hussein (2010) (20), was used. Data were analyzed by using the statistical analysis program of
SPSS 19th versi
The current environment is witnessing several developments as a result of the changes taking place in all areas of economic, social , political and legal that led to the transformation of the industrial economy , which depends based on quantitative production to a knowledge economy which relies based on information and knowledge , as the central pillar of this economy during the trading of these information and knowledge between all individuals in general and decision makers , in particular, through information and communication technology of computers and the Internet to achieve sustainable human development in the social dimension. &
... Show MoreA study of the singlet and triplet states of two electron systems in the first excited state was performed using a simple quantum mechanical model, which assigns the 1s,and 2s orbital with two different variational parameters. Our results agree with a high level calculation used by Snow and Bills.
This study focuses on evaluating the suitability of three interpolation methods in terms of their accuracy at climate data for some provinces of south of Iraq. Two data sets of maximum and minimum temperature in February 2008 from nine meteorological stations located in the south of Iraq using three interpolation methods. ArcGIS is used to produce the spatially distributed temperature data by using IDW, ordinary kriging, and spline. Four statistical methods are applied to analyze the results obtained from three interpolation methods. These methods are RMSE, RMSE as a percentage of the mean, Model efficiency (E) and Bias, which showed that the ordinary krigingis the best for this data from other methods by the results that have b
... Show MoreIn this paper, we establish the conditions of the occurrence of the local bifurcations, such as saddle node, transcritical and pitchfork, of all equilibrium points of an eco-epidemiological model consisting of a prey-predator model with SI (susceptible-infected) epidemic diseases in prey population only and a refuge-stage structure in the predators. It is observed that there is a transcritical bifurcation near the axial and free predator equilibrium points, near disease-free equilibrium point is a saddle-node bifurcation and near positive (coexistence) equilibrium point is a saddle-node bifurcation, a transcritical bifurcation and a pitchfork bifurcation. Further investigations for Hopf bifurcation near coexistence equilibrium point
... Show MoreThe research mainly seeks to predict the amounts of non- oil Iraqi exports which concludes ) Food & Animals , Raw materials and non- tanned Leather and fur , Mineral fuels and Lubricating Oil , Chemical substances and amounts , Manufactured goods , Electrical and non - electrical machines , Supplies and Total non- Oil exports ) by using Markov Chain as one of Statistical approach to forecasting in future . In this search We estimate the transliteration probabilities matrix according to Maximum Likelihood on a data collected from central organization for Statistics and information technology represents an index numbers of non- Oil exports amount in Iraq from 2004 to 2015 depending on 2007 as a basic year . Results shown that trend of index
... Show More