The unsteady state laminar mixed convection and radiation through inclined
cylindrical annulus is investigated numerically. The two heat transfer mechanisms of
convection and radiation are treated independently and simultaneously. The outer
cylinder was kept at a constant temperature while the inner cylinder was heated with
constant heat flux. The study involved numerical solution of the governing equations
which are continuity, momentum and energy equations using finite difference method
(FDM), where the body fitted coordinate system (BFC) was used to generate the grid
mesh for computational plane. A computer program (Fortran 90) was built to calculate
the bulk Nusselt number (Nub) after reaching steady state condition for fluid Prandtl
number fixed at (Pr =0.7) (for air) with radius ratio ( =1.5, 2.6, 5.0), Rayleigh number
(0≤Ra≤103),Reynolds number (50≤Re≤2000), dimensionless heat generation (0≤Q≤10),
Conduction-Radiation parameter (0≤N≤10), optical thickness (0 ≤ t
≤ 10) and different
annulus inclination with horizontal plane (0°≤δ≤90°). For the range of parameters
considered, results show that radiation enhance heat transfer. It is also indicated in the
results that Nu increase with the increasing of inclination angle δ, Ra, Re, and Q. The
correlation equations are concluded to describe the radiation effect.
Comparison of the result with the previous work shows a good agreement.
In the present study, the effect of new cross-section fin geometries on overall thermal/fluid performance had been investigated. The cross-section included the base original geometry of (triangular, square, circular, and elliptical pin fins) by adding exterior extra fins along the sides of the origin fins. The present extra fins include rectangular extra fin of 2 mm (height) and 4 mm (width) and triangular extra fin of 2 mm (base) 4 mm (height). The use of entropy generation minimization method (EGM) allows the combined effect of thermal resistance and pressure drop to be assessed through the simultaneous interaction with the heat sink. A general dimensionless expression for the entropy generation rate is obtained by con
... Show MoreSocial risks posed a great challenge to the development path in Iraq, which resulted in widening the development gaps, whether these gaps were between rural and embargoed areas, or between Iraqi governorates, and the gender gap. Besides, the nature of the reciprocal relationship between the social risks and the development process requires the adoption of development trends that are sensitive to the risks that take upon themselves the prompt and correct response to these risks, away from randomness and confusion that Iraq suffered from for decades. However, currently, the situation has differed a great deal. This is because the size and types of such gaps have widened and become more complicated than before; a matter which has led to hav
... Show MoreRotaviruses, a major cause of gastroenteritis in children worldwide accounts for around half a million deaths annually. Vaccine against the virus has been recommended by the WHO to be involved in the national immunization program.To evaluate the genetic characterization of rotavirus among children with acute gastroenteritis in Babylon province is warranted. Children complained of diarrhea with rotavirus infection detected in their stool were involved in the study. The age range was 10 months to 60 months and with retrogradechecking of rotavirus vaccine history. Rotavirus genotypes were detected by reverse transcription-polymerase chain reaction (RT-PCR).A total number of 40 children with rotavirus gastroenteritis were used to examine the
... Show MoreHuman resources constitute the most important recourses that the organization owned today, as it may have developed financial and technology resources to achieve their goals, but they are not able to use it with required efficiency and effective and quality desired unless there is human resources that have good skills, experiences and talents that able to directing and exploited ideally that compatible with market requirements, where today's market and business organizations which compete naturally inherent talent, so the task is to attracting and developing talented resources and preservation these talented resources from the challenges that facing organizations.
The research seek to achieve
... Show MoreAI in teaching English is reshaping language learning. While interest in AI-supported education is growing worldwide, research in this area is still emerging in Iraq. This review synthesizes empirical AI-based intervention studies to enhance English language learning in Iraqi higher education, and the perceptions of stakeholders regarding AI tools in language instruction. The reviewed intervention studies, comprising studies employed different AI platforms to support grammar instruction, speaking fluency, writing feedback, and pragmatic competence. These interventions yielded improvements in learners’ performance, motivation, and communicative confidence. In parallel, perception-focused studies revealed positive attitudes toward A
... Show MoreGod saw his servants with truth and light, and made him easy for them, and he commanded those who help them, including a counselor, guide and preacher, so if a Muslim sees deficiencies or defects, he must help him to reform and refine it. That it was in the hands of the prophets, God Almighty created the human being together straight, then melted on those scholars and researchers in all religions on psychological counseling and religious sychotherapy, stressing the importance of religious values in the process of understanding man in the process of psychotherapy and in controlling human behavior. A lot of research and studies have been published. I dealt with the religious approach in the process of treating mental disorders and the aim of
... Show MoreThe research aims to highlight the significance and composition and the diversity of meanings and the Quranic context in the necessary and transgressive verbs in Surat (Abs).
This research consists of : a preamble , and two studies . The researcher addressed in the preliminary the importance of the phenomenon of necessity and infringement, the signs of the necessary action , the structure and controls of the act , the methods of infringement , its sections and signs.
As for the first topic : The researcher addressed the necessary verbs in Surat Abs , an applied study in terms of grammati
... Show MoreThe Study was achieved adjectives physical and chemical water wells in the district of
Samarra , where a study has 42 sample groundwater in different regions of the judiciary
randomly distributed all over the judiciary and examined in vitro.
The study showed that the quality of groundwater in the general area of study
Kipritateh punctuated Klordih water quality and other quality Bicarboonatih.
Varied the key components of groundwater in the study area in concentrations
between periods of rain and drought, especially because of the cation ion exchange processes
as well as mitigation as a result of filtering rain water and dominated the calcium ion,
followed by sodium.
As for the negative ions has dominated ion s
The importance of the research comes from dealing with the problem of lack of traffic awareness, which causes accidents and the occurrence of human and material losses, and the research aims to study the role of satellite channels in forming traffic awareness among the public, and a sample was chosen from Baghdad consisting of (280) individuals, male and female, and used the questionnaire tool. To obtain the data, which included several questions, the results were analyzed statistically and several results were reached, the most important of which is that there is an interest among the public in following traffic programs at a rate of one to two hours to receive information through traffic programs and to identify and apply gener
... Show MoreObjectives: The study aims at:
1- Measuring the level of lead in workers’ saliva and blood in the factory.
2- Studying the correlation between the saliva lead level and the infection that caused by microorganisms, isolation and
identification.
3-Studying the influence of high blood lead level on the total white blood cells.
Methodology: This study has been conducted for the period from March 15th, 2010 to May, 20th
, 2010. A total of (60)
saliva and blood samples were collected from workers in batteries industry factory in Baghdad and another (20) samples
were collected as a control group. Lead level had been measured in blood and saliva samples, then microorganisms were
isolated the from the saliva samples.