An experimental and numerical study was carried out to investigate the heat transfer by natural convection in a three dimensional annulus enclosure filled with porous media (silica sand) between two inclined concentric cylinders with (and without) annular fins attached to the inner cylinder under steady state condition. The experiments were carried out for a range of modified Rayleigh number (0.2 ≤Ra*≤ 11) and extended to Ra*=500 for numerical study and for annulus inclination angle of (δ = 0˚, 30˚, 60˚ and 90˚). The numerical study was to give the governing equation under assumptions that used Darcy law and Boussinesq’s approximation and then it was solved numerically using finite difference approximation. It was found that the average Nusselt number depends on (Ra*, Hf, δ and Rr ). The results showed that the increasing of the fin length increases the heat transfer rate for any fin pitch unless the area of the inner cylinder exceeds that of the outer one; then the heat will be stored in the porous media. A comparison was made between the results of the present work and those of other researches for the case without fins and excellent agreement was obtained.
Euphemism is an important linguistic phenomenon that tends to soften written or oral expressions. Thus, when translators or interpreters face expressions including euphemism, they need to know how to deal with them. The problem of the current paper lies in the effect of rendering euphemistic expressions inaccurately, as such expressions represent the cultural and terminological sense of the original language. Thus, rendering them improperly will affect the sense of the interpreted speech. For this, it is essential for translators in general and simultaneous interpreters in particular to know the importance of utilizing euphemism in the simultaneous interpreting field, which is the main aim of this paper. To this end, a systematic review
... Show MoreThis research aims to evaluate the teaching methods used by intermediate Arabic language teachers. To achieve the goal, the researcher followed the descriptive-analytical approach. The research sample was limited to Arabic language teachers at intermediate school for the academic year (2017-2018) the researcher chose a random sample included (155) teachers which form a (40%) Of the original community at Baghdad/ Rusafa1th. The researcher has developed standards of teaching methods which are (7) standards with (39) paragraphs included three alternatives. The results showed the need to pay attention to the use of various modern teaching methods. Moreover, the researcher suggested making an evaluation of the teaching methods used by Arabic
... Show MoreObjective: To compare two positioning approaches in the surgical treatment of unstable intertrochanteric femoral fractures fixed by proximal femoral nailing, the supine versus lateral decubitus position Methodology: This randomized prospective comparative study on 26 patients with unstable intertrochanteric fractures was carried out from January 2020 and June 2022. We randomly divided patients into two groups: group A (13 patients) were operated using the traction table in the supine position for implant insertion, and group B (13 patients) were operated using the lateral decubitus position. We compared both groups regarding the setup time, operative time, tip-to-apex distance, collodiaphyseal angle, time for fluoroscopic time expo
... Show MoreThis work is concerned with the vibration attenuation of a smart beam interacting with fluid using proportional-derivative PD control and adaptive approximation compensator AAC. The role of the AAC is to improve the PD performance by compensating for unmodelled dynamics using the concept of function approximation technique FAT. The key idea is to represent the unknown parameters using the weighting coefficient and basis function matrices/vectors. The weighting coefficient vector is updated using Lyapunov theory. This controller is applied to a flexible beam provided with surface bonded piezo-patches while the vibrating beam system is submerged in a fluid. Two main effects are considered: 1) axial stretching of the vibrating beam that leads
... Show MoreThe present work included study of the effects of weather conditions such as solar radiation and ambient temperature on solar panels (monocrystalline 30 Watts) via proposed mathematical model, MATLAB_Simulation was used by scripts file to create a special code to solve the mathematical model , The latter is single –diode model (Five parameter) ,Where the effect of ambient temperature and solar radiation on the output of the solar panel was studied, the Newton Raphson method was used to find the output current of the solar panel and plot P-V ,I-V curves, the performance of the PV was determined at Standard Test Condition (STC) (1000W/m2)and a comparison between theoretical and experimental results were done .The best efficiency
... Show MoreThe problem of Bi-level programming is to reduce or maximize the function of the target by having another target function within the constraints. This problem has received a great deal of attention in the programming community due to the proliferation of applications and the use of evolutionary algorithms in addressing this kind of problem. Two non-linear bi-level programming methods are used in this paper. The goal is to achieve the optimal solution through the simulation method using the Monte Carlo method using different small and large sample sizes. The research reached the Branch Bound algorithm was preferred in solving the problem of non-linear two-level programming this is because the results were better.
Background: Decalcification of surface enamel adjacent to fixed orthodontic appliances, in the form of white spot lesions, is a wide spread and familiar well-known side effect of orthodontic treatment. The present study was carried out to evaluate the effect of enamel protective agent (Clinpro white varnish) on shear and tensile bond strength of Dentaurum orthodontic stainless steel brackets by using 3M Unitek and Ormco as orthodontic adhesive agents. Materials and methods: Sixty-four extracted human upper first premolar teeth were selected and randomly divided into two groups with 32 teeth each, representing the shear and tensile bond strength testing groups. Then according to the type of bonding adhesive and the addition of Clinpro before
... Show MoreThe world and the business environment are constantly witnessing many economic changes that have led to the expansion of the business' volume due to mergers and the increase in an investments volume and the complexity of business and the transformation of some systems, which was reflected on the size of the risk and uncertainty which led to necessity of a presence of transparent and objective accounting information In the way that reflects the financial performance of the economic units to be available to all users of that information, therefore, The need for the existence of indicators for transparency in the disclosure of accounting information that these units adhere to. Standards & Poor's indicators, which included items
... Show MorePolycyclicacetal was prepared from the reaction of PEG with aldehyde derived from Erythro-ascorbic acid (pentulosono-ɣ-lactone-2,3-enedianisoate).All these compounds were characterized by Thin Layer Chromatography (TLC) and FTIR spectra and aldehyde was also characterized by (U.V-Vis), 1HNMR, 13CNMR, and mass spectra.The inhibitory effect of prepared polymer on the activity of human serum AcetylCholinesterase has been studied in vitro. The polymer showed a remarkable activity at low concentration (4.7x10-3 – 4.7x10-8M).
This study was included preparing acold aqueous extract of clove buds The study also comprised the isolation and studying the proteinous compound,which was seperated using gel filtration technique and determined approximately molecular weight of this isolated compound(6799) dalton . The aim of the study demonstrate effects of the crude aqueous, non proteinous extract, proteinous precipitate and proteinous compound on serum glucose, total cholesterol, triglyceride and high density lipoprotein-cholesterol levels, also glutathione and malondialdehyde levels in liver and kidney tissues in diabetic mice-induced alloxan.Extracts were administerated interaperitioneally. The results were indicated that the crude aqueous, non proteinous extr
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