A numerical study of the double-diffusive laminar natural convection in a right triangular solar collector has been investigated in present work. The base (absorber) and glass cover of the collector are isothermal and isoconcentration surfaces, while the vertical wall is considered adiabatic and impermeable. Both aiding and opposing buoyancy forces have been studied. Governing equations in vorticity-stream function form are discretized via finite-difference method and are solved numerically by iterative successive under relaxation (SUR) technique. Computer code for MATLAB software has been developed and written to solve mathematical model. Results in the form of streamlines, isotherms, isoconcentration, average Nusselt, and average Sherwood number, are presented for wide range of the buoyancy ratio , angle of inclined glass cover with horizontal coordinate , Lewis number , thermal Rayleigh number , and Prandtl number . The results show that above parameters have strong influences on the patterns of streamline, isotherms, isoconcentration, average Nusselt number and average Sherwood number. Results show that a decrease in the angle of inclined glass cover with horizontal coordinate ( leads to increase average Nusselt number and average Sherwood number. For (N > 0), both average Nusselt number and average Sherwood number increase with increasing of buoyancy ratio and Rayleigh number. By contrast for ( these values decreases. Also, increasing of the buoyancy ratio for positive (N > 0), at the same Rayleigh number enhance the heat and mass transfer rate. A comparison is made with the previous numerical results and it found to be reveal a good agreement.
This paper studies the demonstratives as deictic expressions in Standard Arabic and English by outlining their phonological, syntactic and semantic properties in the two languages. On the basis of the outcome of this outline, a contrastive study of the linguistic properties of this group of deictic expressions in the two languages is conducted next. The aim is to find out what generalizations could be made from the results of this contrastive study.
Our research deals with the role of theatrical decoration in creating visual thumbs and the effect achieved as a result in the theatrical presentation in terms of supporting the idea of centralization of the dramatic construction of the show, as the researcher emphasizes that this topic has begun with a new horizon removed many technical concepts and knowledge in the theater.
Horizon knowledge and discoveries based on the structures of light and sight to achieve an existing transformation from steel to ethereal. According to these new concepts, systems other than those based on old methods of presentation have been formed.
In light of this, the researcher divided his research into:
First: the problem of research and the need fo
Marriage is considered one of the strongest ties that links between two human beings , but after the evolutions that happened in our Arab communities and specifically in the Iraqi community , marriage through the internet websites appeared . this kind of marriage is considered one of the new phenomena that appeared in the present time in many societies. That was through internet websites like yahoo , Facebook and other websites that have chat features.
The Islamic sharia looks negatively at marriage through the internet announcing that this way is harmful for both the man and the woman
Abstract
Due to the momentum of winning in the streets of the city of Baghdad as a result of the large number of checkpoints so felt researcher to conduct a field visit to find out the main reasons that led to this congestion and to find practical solutions to mitigate wastage winning the arrival time citizen to where you want the least possible time.
This research aims to overcome the difficulties experienced by citizens to reach their places of work and reduce waste at the time of service and waiting time as well as reduce the cost of waiting.
Has emerged study a set of conclusions, including the use of model queue (G / G / C) and the mome
... Show MoreThe Gas Assisted Gravity Drainage (GAGD) process has become one of the most important processes to enhance oil recovery in both secondary and tertiary recovery stages and through immiscible and miscible modes. Its advantages came from the ability to provide gravity-stable oil displacement for improving oil recovery, when compared with conventional gas injection methods such as Continuous Gas Injection (CGI) and Water – Alternative Gas (WAG). Vertical injectors for CO2 gas were placed at the top of the reservoir to form a gas cap which drives the oil towards the horizontal oil producing wells which are located above the oil-water-contact. The GAGD process was developed and tested in vertical wells to increase oil r
... Show MoreProblem of water scarcity is becoming common in many parts of the world. Thus to overcome this problem proper management of water and an efficient irrigation systems are needed. Irrigation with buried vertical ceramic pipe is known as a very effective in management of irrigation water. The two- dimensional transient flow of water from a buried vertical ceramic pipe through homogenous porous media is simulated numerically using the software HYDRUS/2D to predict empirical formulas that describe the predicted results accurately. Different values of pipe lengths and hydraulic conductivity were selected. In addition, different values of initial volumetric soil water content were assumed in this simulation a
... Show MoreFriction stir spot welding (FSSW) is a relatively new welding process that may have significant advantages compared to the fusion processes as follows joining of conventionally non-fusion weldable alloys, reduced distortion and improved mechanical properties of weldable alloys joints due to the pure solidstate joining of metals. In this paper, a three-dimensional model based on finite element analysis is used to study the thermal history in the spot-welding of aluminum alloy 2024. The model take place the thermomechanical property on the process of the welded metals. The thermal history and the evolution results with numerical model at the measured point in the friction stirred spot weld have a good matching, then the prediction of the t
... Show MoreWe present a reliable algorithm for solving, homogeneous or inhomogeneous, nonlinear ordinary delay differential equations with initial conditions. The form of the solution is calculated as a series with easily computable components. Four examples are considered for the numerical illustrations of this method. The results reveal that the semi analytic iterative method (SAIM) is very effective, simple and very close to the exact solution demonstrate reliability and efficiency of this method for such problems.
Harriet Jacobs was a writer and a reformer. As a female writer in the nineteenth century, Jacobs wrote her narrative as a means of resisting the system of slavery. She wrote her book Incidents in the Life of a Slave Girl: Written by Herself, (1842) to reflect upon the exploitation of the black people and the need to change the hierarchal attitude that governs white/black relations. She was engaged in many abolitionist events and her anti-slavery approach appeared clearly in her writings. She shares Du Bios ideas about freedom and emancipation and the need for a political and cultural change. Thus, Du Bois’s theory provides a framework for her autobiographical novel where she portrays Linda Brent, the main character, a strong w
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