This research is devoted to investigating the thermal buckling analysis behaviour of laminated composite plates subjected to uniform and non-uniform temperature fields by applying an analytical model based on a refined plate theory (RPT) with five unknown independent variables. The theory accounts for the parabolic distribution of the transverse shear strains through the plate thickness and satisfies the zero-traction boundary condition on the surface without using shear correction factors; hence a shear correction factor is not required. The governing differential equations and associated boundary conditions are derived by using the virtual work principle and solved via Navier-type analytical procedure to obtain critical buckling temperature. Results are presented for: uniform and linear cross-ply lamination with symmetry and antisymmetric stacking, simply supported boundary condition, different aspect ratio (a/b), various orthogonality ratio (E1/E2), varying ratios of coefficient of uniform and linear thermal expansion (α2⁄α1), uniform and linearly varying temperature thickness ratio (a/h) and numbers of layers on thermal buckling of the laminated plate. It can be concluded that this theory gives good results compared to other theories.
Abstract
The Classical Normal Linear Regression Model Based on Several hypotheses, one of them is Heteroscedasticity as it is known that the wing of least squares method (OLS), under the existence of these two problems make the estimators, lose their desirable properties, in addition the statistical inference becomes unaccepted table. According that we put tow alternative, the first one is (Generalized Least Square) Which is denoted by (GLS), and the second alternative is to (Robust covariance matrix estimation) the estimated parameters method(OLS), and that the way (GLS) method neat and certified, if the capabilities (Efficient) and the statistical inference Thread on the basis of an acceptable
... Show MoreObjective: To determine the functional and radiological outcomes of lower third tibia closed fractures fixed by nail or plate osteosynthesis. Methodology: This randomized controlled trial included 20 patients presenting with closed fracture lower third tibia in Al-Kindy teaching hospital, Baghdad, Iraq. The patients were divided as every other one into two equal groups; group I had fractures fixed by 3.5 mm locked plate and group II by intramedullary locking nail. We followed all patients for 24 weeks to assess surgical complications, fracture union, alignment and functional outcome based on Knee society score (KSS). Results: The mean union time in both groups was 10.2 ± 1.48 and 9.3 ± 1.77 weeks, respectively (p = 0.003). Mean KSS in bot
... Show MoreCeramic coating compose from a ceramic mixture (MgO, Al2O3) and metall (Al-Ni) were produced by Thermal Spray Technique. The mixed ratio of used materials Al:Ni (50%) and 40% of Al2O3 and 10% MgO. This mixture was spray on a stainless steel substrate of type (316 L) by using thermal spray with flame method and at spraying distances (8, 12, 16 and 20) cm, then the prepared films were treated by laser and thermal treatment. After that performing a hardness and adhesion tests were eximined. The present study shows that the best value of the thermal treatment is 1000 ℃ for 30 mint; the optimum spray distance is 12 cm and most suitable laser is 500 mJ where the microscopic and mechanical character
... Show MoreFallacies are incorrect reasoning that make an argument seem less logically credible and easier to be identified as unsound. They are widespread; individuals commit them while engaging in various activities, including at work, at home, while creating advertisements, and in the media. This study aims to investigate the rhetorical strategies accompanied with producing the fallacious arguments selected from the American Film “12 Angry Men (1957)”. The study adopts Damer’s (2009) model for the identification of fallacy. As for rhetorical analysis, the study adopts Aristotle’s triangle of rhetoric and McGuigan’s (2007) taxonomy of rhetorical devices. The results uncover that the most violated criteria are relevance, acceptabili
... Show MoreThe interplay of species in a polluted environment is one of the most critical aspects of the ecosystem. This paper explores the dynamics of the two-species Lokta–Volterra competition model. According to the type I functional response, one species is affected by environmental pollution. Whilst the other degrades the toxin according to the type II functional response. All equilibrium points of the system are located, with their local and global stability being assessed. A numerical simulation examination is carried out to confirm the theoretical results. These results illustrate that competition and pollution can significantly change the coexistence and extinction of each species.
This research is a theoretical study that deals with the presentation of the literature of statistical analysis from the perspective of gender or what is called Engendering Statistics. The researcher relied on a number of UN reports as well as some foreign sources to conduct the current study. Gender statistics are defined as statistics that reflect the differences and inequality of the status of women and men overall domains of life, and their importance stems from the fact that it is an important tool in promoting equality as a necessity for the process of sustainable development and the formulation of national and effective development policies and programs. The empowerment of women and the achievement of equality between men and wome
... Show MoreAlmost all thermal systems utilize some type of heat exchanger. In a lot of cases, evaporators are important for systems like organic Rankine cycle systems. Evaporators give a share in a large portion of the capital cost, and their cost is significantly attached to their size or transfer area. Open-cell metal foams with high porosity are taken into consideration to enhance thermal performance without increase the size of heat exchangers. Numerous researchers have tried to find a representation of the temperature distribution closer to reality due to the different properties between the liquid and solid phases. Evaporation heat transfer in an annular pipe of double pipe heat exchanger (DPHEX) filled with cooper foam is investigated numerical
... Show MoreThis paper examines the use of one of the most common linguistic devices which is hyperbole. It shows how hyperbolic devices are used as an aspect of exaggeration or overstatement for an extra effect in which the speaker can use hyperbole to add something extra to a situation in order to exaggerate his idea or speech. It is, like other figures of speech, used to express a negative or positive attitude of a specific unit of language. Thus, this paper is set against a background of using hyperbole concerning two main fields (advertisements and propaganda). So, the use of hyperbole will be implied by analyzing them concerning their meaning) literal and non-literal). Methodology of this
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