This work presents an experimental study of heat transfer and flow of distilled water and metal oxide nanofluid Fe3O4-distilled water at concentrations of (φ = 0.3, 0.6, 0.9 %) by volume in a horizontal pipe with constant magnetic field. All the tests are carried out with Reynolds number range (2900-9820) and uniform heat flux (11262-19562 W/m2). The results show that, the nanofluid concentration and magnetic intensity increase, the Nusselt number increases. The maximum enhancement in Nusselt number with magnetic nanofluid is (5.4 %, 26.4 %, 42.7 %) for volume concentration (0.3, 0.6, 0.9 %) respectively. The enhancement is maximized with magnetic intensity (0.1, 0.2, 0.3 tesla) respectively to (43.9, 44.3, 46 %) with volume concentration (0.9 %). The heat transfer enhancement decreases with the increasing of Reynold number with using magnets. The friction factor increases with nano volume concentration increase and the intensity of magnet and decreases with increase of Reynold number.
Abstract
The research aims to identify tax exemptions, their objectives and types, as well as to shed light on the concept of sustainable development, its objectives, dimensions and indicators (economic, social and environmental), as well as to analyze the relationship between tax exemptions and economic development, in addition to measuring and analyzing the impact of tax exemptions on economic development in Iraq for the period ( 2015 - 2021) using the NARDL model. The research problem centers on the fact that failure to employ financial policy tools correctly led to a weakness in achieving economic justice, which leads to a failure to improve social welfar
... Show MoreShell-and-double concentric tube heat exchanger is one of the new designs that enhance the heat transfer process. Entransy dissipation is a recent development that incorporates thermodynamics in the design and optimization of heat exchangers. In this paper the concept of entransy dissipation is related to the shell-and-double concentric tube heat exchanger for the first time, where the experiments were conducted using hot oil with temperature of 80, 100 and 120°C, flow rate of cold water was 0.667, 1, and 1.334 kg/m3 respectively and the temperature of inlet cold water was 20°C. The entransy dissipation rate due to heat transfer and to fluid friction or pressure drop was studied.
Methotrexate (MTX) is one of the most effective medications to treat rheumatoid arthritis (RA).Aserum of 60 Iraqi male patients suffering from RA as (G1) was newly diagnosis and the same patient in G1 after taking MTX as G2 and 40 Iraqi male healthy control as G3. Nesfatin-1 (Nf-1) is belong to the adipokine family withpleiotropic effect. Nf-1 has been found in different tissues, including stomach, pancreas, bone cells, cartilage and heart. Retinol binding protein (RBP4) was known as transpoter of retinol from its storage sites in the liver to the extrahepatic tissues. Moreover, RBP4 acts as adipokine and contributes in the pathophsyology of prototypic inflammatory disease, rheumatoid arthritis (RA). The results showed a significant increas
... Show MoreIschemic heart disease is a major causes of heart failure. Heart failure patients have predominantly left ventricular dysfunction (systolic or diastolic dysfunction, or both). Acute heart failure is most commonly caused by reduced myocardial contractility, and increased LV stiffness. We performed echocardiography and gated SPECT with Tc99m MIBI within 263 patients and 166 normal individuals. Left ventricular end systolic volume (LVESV), left ventricular end diastolic volume (LVEDV), and left ventricular ejection fraction (LVEF) were measured. For all degrees of ischemia, there was a significant difference between ejection fraction values measured by SPECT and echo
To identify the importance of the role of succession planning in developing human capital in organizations in light of the accelerating and dynamic events and changes in the work environment, and the research problem indicated the seriousness of employees retiring or leaving their positions for any reason and the extent of its impact on the organization in creating gaps in leadership and problems In managing the talent injection because there will be a shortage of talent, which in turn will affect the general performance of the business in the researched institute, so the importance of research appears in trying to present a set of solutions through which some of the problems facing the organization in quest
... Show MoreThe research aims to shed light on the impact of the application of the electronic services system on electronic banking activities in a sample of Iraqi banks, as investment in technology is the most important factor for the success and future growth of administrative companies in general, and banking in particular, as global economic developments in the field of Technology has led the majority of banking sectors in the world to undergo deep reforms and radical changes in the entity of their systems and mechanisms to confront competition and keep pace with economic changes, as the concept of banking services and its diversity changed with it, especially since persistence in the traditional approach no longer gi
... Show MoreMixed-effects conditional logistic regression is evidently more effective in the study of qualitative differences in longitudinal pollution data as well as their implications on heterogeneous subgroups. This study seeks that conditional logistic regression is a robust evaluation method for environmental studies, thru the analysis of environment pollution as a function of oil production and environmental factors. Consequently, it has been established theoretically that the primary objective of model selection in this research is to identify the candidate model that is optimal for the conditional design. The candidate model should achieve generalizability, goodness-of-fit, parsimony and establish equilibrium between bias and variab
... Show MoreThis study aimed to know the impact of the capital structure measured by the ratio of financing to short-term capital and the ratio of financing to long-term capital on the profitability of companies, as measured by the rate of return on assets and the rate of return on equity. The study was applied to industrial sector companies listed in the Iraq Stock Exchange. The financial number of (14) companies, and (4) companies were selected that met the conditions for selecting the study sample. The study methodology relies on the analytical method as it is more appropriate to the nature, scope and objectives of the study, and the ready-made statistical program "SPSS" will be used to analyze the relationships and influence between the
... Show MoreThe research aims to investigate the relationship and impact of e-governance as an independent variable in achieving creative performance as a dependent variable. These variables have been studied in the Directorate of Passports Affairs, and seek to come up with a set of recommendations that help in promoting e-governance in the researched organization, and the researcher adopted the descriptive-analytical approach, included The sample (122) of the total (194) individuals distributed in several administrative levels (officers, associates, and administrative staff). By adopting the questionnaire, which included (49) paragraphs as the main tool for the collection of data and information, as well as personal interviews and field obs
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