This paper aims to study the effect of circular Y-shaped fin arrangement to improve the low thermal response rates of a double-tube heat exchanger containing Paraffin phase change material (PCM). ANSYS software is employed to perform the computational fluid dynamic (CFD) simulations of the heat exchanger, including fluid flow, heat transfer, and the phase change process. The optimum state of the fin configuration is derived through sensitivity analysis by evaluating the geometrical parameters of the Y-shaped fin. For the same height of the fins (10 mm), the solidification time is reduced by almost 22%, and the discharging rate is enhanced by almost 26% using Y-shaped fins compared with the straight fins. The results demonstrate that the solidification time is inversely proportional to the fin's length. The heat release rate for the case with the longest fins (stem length of 10 mm) is 39 W, almost 2.8 times higher than that with the fins' stem length of 5 mm. The case with the tributary's angle of 22.5o solidified in 55 min, faster than the other studied angles. Increasing the number of fins significantly affects the solidification time and discharging rate. By increasing the number of fins from 3 to 9, the heat transfer rate improves by 194%. The advantages of circular Y-shaped fins are well known in heat transfer applications and therefore are characterized toward higher performance in this study for the first time during the solidification process.
This research aims to study the influence of organizational power on the achievement of entrepreneurship for business organizations. It is an analytical study of the views of a sample of managers in the Iraqi Ministry of Education. The research highlights the contribution that can be made from the knowledge of the theory of business organizations in achieving organizational success. The organizational power of the organization contributes to achieving entrepreneurship in the business environment and achieving a competitive position in the work environment. The research dealt with two variables: the first is the independent variable, the organizational power in its dimensions (Expend Power, Structural Power, Prestige Power). And t
... Show MoreThe study aims at diagnosing the importance of environmental analysis (external, industrial and internal) in the organization's strategy for the development of public organizations. The theoretical problem derived from the existence of a knowledge gap for studies and research that dealt with the variables of the study. Three public organizations were selected as the study society (the Civil Defense Directorate, the Directorate of Nationality, Passports and Residency, the General Traffic Directorate). The sample of the study was a sample of (215) managers (managers, department managers, Analysis of the data and hypothesis testing using the appropriate statistical tools, Pearson, the simple and multiple regression coefficient to te
... Show MoreHydrothermal process method using different dimensions reactors with volume 100 ml (homemade) was employed to prepare titanium sub-oxide Ti6O11, where one gram of TiO2 nanoparticles 30-50 nm and 3M (20 ml) of NaOH as suspension was used . The samples are characterized using X-ray diffraction, Raman spectroscopy, and Field Emission Scanning Electron Microscopy (FE-SEM). X-ray diffraction revealed the formation of sub- oxide titanium Ti6O11 of triclinic structure with Magneli phase, when the temperature applied was 363K for 9h.While FE-SEM showed uniform hierarchical structures with planar grass-like shapes. A novel phase has been found from rutile titanium.
Pregnancy-induced hypertension (PIH) is a major pregnancy complication that causes pregnant women mortality. Here, we had scrutinized the correlation between serum levels of -hCG and biochemical parameters in PIH. Serum samples were collected from eighty Iraqi women (forty women with pregnancy-induced hypertension as patients group, twenty normotensive pregnant women as a positive control, and twenty normotensive non-pregnant women as a negative control) all groups were diagnosed clinically. All -hCG hormone level was measured for all studied groups, also serum uric acid, albumin, and total protein levels were measured as biochemical parameters. Data analysis showed that serum level of -hCG hormone was significant increase (p≤
... Show MoreThis paper argues the accuracy of behavior based detection systems, in which the Application Programming Interfaces (API) calls are analyzed and monitored. The work identifies the problems that affecting the accuracy of such detection models. The work was extracted (4744) API call through analyzing. The new approach provides an accurate discriminator and can reveal malicious API in PE malware up to 83.2%. Results of this work evaluated with Discriminant Analysis
In this research the Empirical Bayes method is used to Estimate the affiliation parameter in the clinical trials and then we compare this with the Moment Estimates for this parameter using Monte Carlo stimulation , we assumed that the distribution of the observation is binomial distribution while the distribution with the unknown random parameters is beta distribution ,finally we conclude that the Empirical bayes method for the random affiliation parameter is efficient using Mean Squares Error (MSE) and for different Sample size .
Background:
The rubber ropes exercises affected muscle groups, which in turn affects the corners of the conditions of the body before and over the barrier where affected the time passed. To change the angle of the approaching and payment impact on passing each times the barrier 1-5. That passed over the barrier 1and gate 5 impacts on the nature of the achievement, where time has become less. Find the values of cruise missiles and other phases and stages of pitch angle other categories which it enshrines stood as compelling rejection men's 110m hurdles. Find the value of the instant messaging distances between different barriers and stages. Studies by adding rubber sling barriers race categories, measurement of kinematic variables. Emphasis on the devel
... Show More