Numerical simulations have been carried out on the solar chimney power plant systems. This paper gives the flow field analysis for a solar chimney power generation project located in Baghdad. The continuity, Naver-stockes, energy and radiation transfer equations have been solved and carried out by Fluent software. The governing equations are solved for incompressible, 3-D, steady state, turbulent is approximated by a standard k - model with Boussiuesq approximation to study and evaluate the performance of solar chimney power plant in Baghdad city of Iraq. The different geometric parameters of project are assumed such as collector diameter and chimney height at different working conditions of solar radiation intensity (300,450,600,750 and 900 W/m2) to gain the optimal designed structure. The results show that the change of collector diameter and chimney height has considerable effects on the performance of the system. The velocity increase when the collector diameter and chimney height increase and reach to the maximize value at H=D 12 m and when solar intensity (900 W/m2). The study shows that Iraqi weather are suitable for this system.
The two dimensional steady, combined forced and natural convection in vertical channel is
investigated for laminar regime. To simulate the Trombe wall channel geometry properly, horizontal
inlet and exit segments have been added to the vertical channel. The vertical walls of the channel are
maintained at constant but different temperature while horizontal walls are insulated. A finite
difference method using up-wind differencing for the nonlinear convective terms, and central
differencing for the second order derivatives, is employed to solve the governing differential
equations for the mass, momentum, and energy balances. The solution is obtained for stream
function, vorticity and temperature as dependent variables
An experiment during the two seasons 2019, 2020. The experiment conducted according to Split Plot Design by two factors; the first was addition Nano NPK with five levels (control, addition 7.5 g.plant-1, addition 15 g.plant-1, spray 1 g.L-1, spray 2 g.L-1). The second factor was four levels of Mineral NPK which were (control, 50 g.plant-1, 100 g.plant-1, 50 g.plant-1+1.5 g.L-1) respectively. N3 (spray 1 g.L-1 ) increased plant height, stem diameter first season, branch number se
The available experimental data of proton electronic stopping power for Polyethylene, Mylar, Kapton and Polystyrene are compared with Mathematica, SRIM2013, PSTAR and libdEdx programs or databases. The comparison involves sketching out both experimental and databases data for each polymer to discuss the agreement. Further, we use statistical means via standard deviation resulting from the mean normalized difference to describe the precise agreement among the databases and the experimental data. We found that there is not a specific one database can describe the experimental data for certain material at given proton energy.
This study proposed a biometric-based digital signature scheme proposed for facial recognition. The scheme is designed and built to verify the person’s identity during a registration process and retrieve their public and private keys stored in the database. The RSA algorithm has been used as asymmetric encryption method to encrypt hashes generated for digital documents. It uses the hash function (SHA-256) to generate digital signatures. In this study, local binary patterns histograms (LBPH) were used for facial recognition. The facial recognition method was evaluated on ORL faces retrieved from the database of Cambridge University. From the analysis, the LBPH algorithm achieved 97.5% accuracy; the real-time testing was done on thirty subj
... Show MoreStenography is the art of hiding the very presence of communication by embedding secret message into innocuous looking cover document, such as digital image, videos, sound files, and other computer files that contain perceptually irrelevant or redundant information as covers or carriers to hide secret messages.
In this paper, a new Least Significant Bit (LSB) nonsequential embedding technique in wave audio files is introduced. To support the immunity of proposed hiding system, and in order to recover some weak aspect inherent with the pure implementation of stego-systems, some auxiliary processes were suggested and investigated including the use of hidden text jumping process and stream ciphering algorithm. Besides, the suggested
... Show MoreIn this paper, we applied the concept of the error analysis using the linearization method and new condition numbers constituting optimal bounds in appraisals of the possible errors. Evaluations of finite continued fractions, computations of determinates of tridiagonal systems, of determinates of second order and a "fast" complex multiplication. As in Horner's scheme, present rounding error analysis of product and summation algorithms. The error estimates are tested by numerical examples. The executed program for calculation is "MATLAB 7" from the website "Mathworks.com
This study aims to identify the role of satellite channels in imparting behavior to children from the point of view of their parents in Tulkarm city. The researcher used a descriptive technique. A sample of (18000) males and females married couples was used above 20 years old in the city of Tulkarm. The study sample size is (201) married couples. It took place in September 2020. The questionnaire was the main tool for collecting data. The study found that the total degree of satellite channels contribution in imparting negative behaviors to children was high, as it reached (72.20%). The total degree of the role of satellite channels in imparting positive behaviors to children was medium, reaching (69.20%). Moreover, the results also indi
... Show MoreBackground: Pain, swelling and trismus are the main minor complications encountered after surgical extraction of impacted third molars, minimizing these postoperative complications is the center of many studies, one proposed method is the prophylactic administration of corticosteroids, the aim of this study is to evaluate the effect of prophylactic Dexamethasone administration on facial swelling and trismus after surgical extraction of impacted third molars. Materials and methods: 20 patients were included in this study, they were randomly divided into 2 groups of 10 patients each; a study group in which patients were given 8 mg. Dexamethasone 1 hour before surgical extraction of impacted third molar and 4 mg. 6 hours postoperatively, and a
... Show MoreThis survey investigates the thermal evaporation of Ag2Se on glass substrates at various thermal annealing temperatures (300, 348, 398, and 448) °K. To ascertain the effect of annealing temperature on the structural, surface morphology, and optical properties of Ag2Se films, investigations and research were carried out. The crystal structure of the film was described by Xray diffraction and other methods.The physical structure and characteristics of the Ag2Se thin films were examined using X-ray and atomic force microscopy (AFM) based techniques. The Ag2Se films surface morphology was examined by AFM techniques; the investigation gave average diameter, surface roughness, and grain size mutation values with increasing annealing temperature
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