The reduction of vibration properties for composite material (woven roving E-glass fiber plies in thermosetting polyester matrix) is investigated at the prediction time under varied combined temperatures (60 to -15) using three types of boundary conditions like (CFCF, CCCF, and CFCC). The vibration properties are the amplitude, natural frequency, dynamic elastic moduli (young modulus in x, y directions and shear modulus in 1, 2 plane) and damping factor. The natural frequency of a system is a function of its elastic properties, dimensions, and mass. The woven roving glass fiber has been especially engineered for polymer reinforcement; but the unsaturated thermosetting polyester is widely used, offering a good balance of vibration properties at moderate or ambient temperatures, and also at relatively low cost. The mismatch between matrix and fiber yarns gives a predominant role for the fiber's mechanics where the matrix is the area where most damage mechanisms develop. The free vibration test was carried out for (5, 10, 15, 20, 25, 30) minutes. The composite plate was exposed to (75) of thermal gradient for ten times in various times at different stages. The results were classified into experimental and finite element using software ANSYS Ver. 9.
In this research, a selection of some mineral water was selected on the basis of being the most marketed by the owners of shops in Najaf province, with six types, where daily samples of this water were taken by 50 ml for two months from (1/11/2018 -1/1/2019). The following ions concentrations were measured (Br-, Cl-, F-, NO3-, SO42-, Na+, K+, Ca2+, Mg2+), pH and the electrical conductivity were measured and the results were compared with the allowable rates according to the international organizations. It was noted that they conform to international and Iraqi standards.
Radiotherapy is the branch of clinical medicine concerned with the application of ionizing radiation in the treatment of disease. And it is used to killing of cancer cells in a tissue using ionizing radiation while keeping the sparing of healthy cells at acceptable level. X-ray beams are used to deposit absorbed dose at depth within a patient at the site of the tumor. The aim of this work is studying the relationship between the depth dose and the field size in water phantom and homogenous actual planning. In our work, the dose distribution at different depths (zero-18 cm) deep at1cm interval treated with field size (10×10 and 20×20) cm2 were studied. Results show that high similarity between water phantom and actual planning for
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The current research aims to reveal the extent to which all scoring rubrics data for the electronic work file conform to the partial estimation model according to the number of assumed dimensions. The study sample consisted of (356) female students. The study concluded that the list with the one-dimensional assumption is more appropriate than the multi-dimensional assumption, The current research recommends preparing unified correction rules for the different methods of performance evaluation in the basic courses. It also suggests the importance of conducting studies aimed at examining the appropriateness of different evaluation methods for models of response theory to the
... Show MoreThe world witnessed variables influenced on entirely education essential mean to grantee the required adaption of inner and external motivations circumstances this gives us opportunity of the best selection means to achieve the goals for progress individual and community .
From here appeared the needs of scientific study interest in new styles of education locate the old place that become non able to granting students and their tendency n
... Show MoreRecent research have aimed to know the effect of rational inquiry strategy on acquisition basic science processes for second intermediate students in physics. To verify the aim of this research , the researchers added the following zero hypotheses : No statistically significant differences at the level of significance (0.05) between the students mean scores of the two groups on basic science Processes test. The research was carried out on the second intermediate grade male students in Alam Al Yakeen school in Baghdad; belong to Education Directorate Al- Karkh/2, for the Academic Year (2014-2015) A.D. Prepared research requirements included ] selected the scientific subject chapters (6,7,8,9) from physics textbook, the formulation of beha
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Nations managed today to achieve progress in the field of modern technology. Science has changed many beliefs and trendiness that people have held for long time, skills and scientific thinking developed, and made scientific observation and experiment replace narration and taking from others. That is attributed to examining the educational systems searching for the locations of defect, and shortage.
In the light of educational modernizations, many models of teaching incliuding a model for social tracing attributed to Herbart Thelen, which is a model to develop skills of social participation in the democratic process (Al-Khawalda,1993,335).
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