The investigation of natural convection in an annular space between two concentric cylinders partially filled with metal foam is introduced numerically. The metal foam is inserted with a new suggested design that includes the distribution of metal foam in the annular space, not only in the redial direction, but also with the angular direction. Temperatures of inner and outer cylinders are maintained at constant value in which inner cylinder temperature is higher than the outer one. Naiver Stokes equation with Boussinesq approximation is used for fluid regime while Brinkman-Forchheimer Darcy model used for metal foam. In addition, the local thermal equilibrium condition in the energy equation of the porous media is presumed to be applicable for the present investigation. CFD ANSYS FLUENT software package (version 18.2) is used as a solver to this problem. Various parameters are examined; Rayleigh number, Darcy number, and thermal conductivity ratio to study the effect of them on fluid flow and heat transfer inside the annuli space in the suggested design of metal foam layer. current model is compared with the available published results and good agreement is noticed. Results showed that as Rayleigh number increases the dominated of convection mode increases and Nusselt increases. Also, Nusselt is larger at the higher Darcy and thermal conductivity ratio. It was found that at Rayleigh of 106 and thermal conductivity ratio of 104 Nusselt reach its higher value which is 6.69 for Darcy of 0.1 and 6.77 for Darcy of 0.001. A comparison between this design and the traditional design was established for Darcy 0.001 and thermal conductivity ratio 102, and its showed a good enhancement in Nusselt number and the greatest enhancement percentage was 44% at Rayleigh equal 5*104 while the lowest percentage is 6% for Rayleigh equal106.
In this study, the researcher aims to analyze the content of the physics textbook for the 3rd intermediate grade according to the criteria for designing and producing infographics, and the research community consists of the content of the physics textbook for the 3rd intermediate grade intermediate grade for the academic year 2021-2022. The researcher adopted the analysis instruments with a number of the criteria for designing and producing infographics. The results revealed randomness in the percentage of the criteria included in the content of the physics textbook for the 3rd intermediate grade, and they are not compatible with the proposed criteria by the experts also.
We have focused the research problem through an assessment of the applicability of the third pillar of the decisions of the Basel Committee 11 (market discipline) or not and its impact on both the adequacy of bank capital, supervisory oversight and banking risks and the statement weaknesses commitment banking institutions and which in turn lead to the stability of the financial system as a whole. .
The research is important statement on the importance of big capital in the banking business and the attributes of a role in the absorption of losses suffered by the bank, which reflects the willin
Objective : To assess the efficiency for some disinfectants against the microorganisms isolated from
the wards of newborn and premature babies in Educational Baghdad Hospital .
Methodology :This study had done from 1\8\2014 untile 1\9\2014, we had selected three types of
disinfectants ( Incidine , Bleach and Microbac Forte )which were used for disinfection in the wards of
newborn babies at Educational Baghdad Hospital to assess their effect against the microorganisms
isolated from these wards and study the mixed affect of these disinfectants againt same
microorganisms .
Results : The results of the present study showed that there is affect of the different concentrations of
the used disinfectants against the micro
This paper describes the first occurrence of the monogenetic trematode Silurodiscoides
mediacanthus (Achmerow, 1952) in Iraq from gills of the cyprinid fish Barbus luteus from
Diyala river, Diyala province, Iraq. The description and measurements of this parasite were
given. In addition, key for the identification of the three species of Silurodiscoides, so far
recorded from freshwater fishes of Iraq, is included.
Government spending is the tool that the state uses to achieve its various goals. The research aims to identify the most important determinants of government spending in Iraq and to indicate the type and nature of the relationship between government spending and its determinants, which will contribute to understanding the movement of government spending. The results of the co-integration test using the border test methodology showed that the variables of population growth and oil prices have a long-term effect on government spending while inflation is not significant in the long run, and that 47% of the equilibrium imbalance (short-term imbalance) in government spending in the previous period (t-) can be corrected in the current period (t)
... Show MoreThe study aims to identify the role of Nizwa University in disseminating the concept of knowledge economy among students from the point of view of the faculty members. The researchers used the descriptive approach, as well as used a questionnaire consisting of (20) items distributed into (4) fields. It was administered to a sample of (93) Faculty members. The results of the study showed that the role of the Nizwa University in spreading the concept of knowledge economy among students from the point of view of the faculty members was of a moderate degree. The education and training field came first with the highest average, while the scientific research and innovation field came in the last level. There were no statistically significant d
... Show MoreAbstract
The study aims to know the degree of secondary school managers' practice of servant leadership in Gaza from their teachers’ perspective. It further aims to examine whether there are any statistically significant differences at (α 0.05≥) between the means of the study sample’s members attributed to variables such as (gender, educational qualification, and years of experience). To achieve the objectives of the study, the study adopted the descriptive survey method, using a questionnaire consisting of (30) items distributed to four domains: (workers service, ethical dealing, motivation & influence, and building an organized, integrated society). Then, the questionnaire was distributed to t
... Show MoreBackground: Tooth wear is one of the most common problems in the older dentate population which results from the interaction of three processes (attrition, abrasion and erosion) and it affects all societies, different age groups, and all cultures. This study was achieved to evaluate the prevalence and distribution of tooth wear among institutionalized residents in Baghdad city\ Iraq. Subjects and Methods: This survey was accomplished on four private and one governmental institution in Baghdad city. One-hundred twenty three (61 males, 62 females) aged 50-89 years were participated in this study. The diagnosis and recording of tooth wear were according to criteria of Smith and Knight. Results: The prevalence of tooth wear was 100% with a mean
... Show MoreThe study titled “The role of the social media sites of Iraqi satellite channels in prioritizing the public” is a field study for the public of Dhi Qar.
The emergence of the social networking sites we are currently experiencing has undergone radical and important changes in the role of the mass media in light of the growth and rapid spread of modern technologies Or the so-called new media، which led the media organizations to create satellite channels on the social networks، which led to bypass the traditional lines between the public and media institutions with the public gain the possibility of The purpose of the research is to determine the habits and patterns of public use of the social media sites of the Iraqi satellite cha