The main objective of this research is to design and select a composite plate to be used in fabricating wing skins of light unman air vehicle (UAV). The mechanical properties, weight and cost are the basis criteria of this selection. The fiber volume fraction, fillers and type of fiber with three levels for each were considered to optimize the composite plate selection. Finite element method was used to investigate the stress distribution on the wing at cruise flight condition in addition to estimate the maximum stress. An experiments plan has been designed to get the data on the basis of Taguchi technique. The most effective parameters at the process to be find out by employing L9 (33) orthogonal array, signal to noise ratio (S/N), main effect and analysis of variance (ANOVA). The results show that, the experimental and the predicted results are very close. It was found that the type of fiber is the most effective parameter on the plate selection, followed by filler content and then the fiber volume fraction. The best parameters combinations are ((E-glass woven roving + unidirectional carbon) fiber, 7.5% graphite filler and 30% fiber volume fraction). This combination provides good mechanical properties, high safety factor, acceptable cost, and offers weight savings on average by 40% percent as compared to aluminum alloy.
يهدف البحث الى التعرف على مستوى الشغف الدراسي عند طلبة المرحلة المتوسطة والتعرف على الفروق تبعاً اناث(، وتحقيقا 423 وطالبة، ً لمتغير الجنس )ذكور- ألهداف البحث الحالي تم اختيار عينة من الطلبة بلغت ) ( طالباً وقد أعد الباحثان أداة البحث، وهو مقياس الشغف الدراسي، الذي تألف من )30 )فقرة ومن خمسة مجاالت )فاعلية الذات، والسيطرة غير المؤكدة، واالندماج الدراسي، والقلق الدراسي، والعالقة بين المدرس والطالب(، على وفق نظرية )
... Show MoreResearch was: 1- known as self-efficacy when students perceived the university. 2- know the significance of statistical differences in perceived self-efficacy according to gender and specialty. Formed the research sample of (300) students were chosen from the original research community by way of random (150) male specialization and scientific and humanitarian (150) females specialized scientific and humanitarian. The search tool to prepare the yard tool to measure perceived self-efficacy based on measurements and previous literature on the subject of perceived self-efficacy. The researcher using a number of means, statistical, including test Altaúa and analysis of variance of bilateral and results showed the enjoyment of the research s
... Show MoreThe current research tries to study the reasons for lying since its
inception, as it is interesting to a child's moral growth, which can benefit from
the results of this research by institutions of socialization, parents and
teachers in the treatment and care of children.
The objective of this research is to highlight the reasons for lying to the
children from the viewpoint of teachers and the answer to the paragraphs of
research designed research instrument (questionnaire) was distributed to a
sample of teachers was clear from the analysis that the reasons lie that
received a high percentage of members of the sample are: -
- The fear of severe punishment
- Child rid himself of a specific problem
- To sat
This research is an attempt to unveil the cover and unveil a matter that has become mysterious to those who came after Sibweh of the grammar scholars; It took place as a result of the work of the scribes.
Context and its influence in direction of reference by Abi Hussein Al Basri
In this paper we use Bernstein polynomials for deriving the modified Simpson's 3/8 , and the composite modified Simpson's 3/8 to solve one dimensional linear Volterra integral equations of the second kind , and we find that the solution computed by this procedure is very close to exact solution.
The wear behavior of alumina particulate reinforced A332 aluminium alloy composites produced by a stir casting process technique were investigated. A pin-on-disc type apparatus was employed for determining the sliding wear rate in composite samples at different grain size (1 µm, 12µm, 50 nm) and different weight percentage (0.05-0.1-0.5-1) wt% of alumina respectively. Mechanical properties characterization which strongly depends on microstructure properties of reinforcement revealed that the presence of ( nano , micro) alumina particulates lead to simultaneous increase in hardness, ultimate tensile stress (UTS), wear resistances. The results revealed that UTS, Hardness, Wear resistances increases with the increase in the percentage of
... Show MoreTin:antimony oxides composites have given great attention due to their unique properties and many application in various fields like optoelectronic devices, gas sensors. The synthesis and characterization of (SnO2)1-x(Sb2O3)x was conducted in order to comprehend the structure and discuss the optical and dielectric properties of this composites. The x-ray showed that the prepared pure tin oxide thin film was had a polycrystalline structure and that the peaks were identical with the tetragonal phase while the peaks were identical with antimony oxide for x=0.1 to x=0.5. The average crystal size along the preferred level of growth of tin oxide as well as of antimony oxide showed non regular change by i
... Show Morethe contemporary Arab scholars deal with semiotics as an approach that helps them understand the texts, its meaning, and its structural functionalism . that’s why every now and then we find some
studies and researches using semiotics as an approach in study and comparatives, some of them even used the semiotic approach in analyzing old and new texts, while others think that semiotic holds and important place in critical approaches .
even though some of them considers semiotic just a trend of fashion this really didn’t lessen the value of semiotic as a scientific and procedural approach in literary and media studies as well as in analyzing literary and journalistic texts. for this reason it is considered as an important approa