The two dimensional steady, combined forced and natural convection in vertical channel is
investigated for laminar regime. To simulate the Trombe wall channel geometry properly, horizontal
inlet and exit segments have been added to the vertical channel. The vertical walls of the channel are
maintained at constant but different temperature while horizontal walls are insulated. A finite
difference method using up-wind differencing for the nonlinear convective terms, and central
differencing for the second order derivatives, is employed to solve the governing differential
equations for the mass, momentum, and energy balances. The solution is obtained for stream
function, vorticity and temperature as dependent variables by iterative technique known as successive
substitution with overrelaxation. The flow and temperature patterns in the channel are obtained for
Reynolds numbers and Grashof number ranging from 25 to 100 and (100 to 1,000,00,) respectively.
A computer program ( Fortran 90 ) is built to calculate the fraction factor and the total
average Nusselt number (Nu) also the average heat transfer Q in steady state and for Aspect ratio Ar
(10) and Grashof number GR (10 2 − 10 5 ), the fluid Prandtl number is fixed at (Pr=0.733) and
Reynolds number Re (25-100).
The results show reasonable representation to the relation between Nusselt number and friction
factor with other parameters (Ar, GR and Re). Nu is increased with increasing Re and GR but it
decreases with Ar increase and (Q) is increased with increasing Re ,GR and Ar. At the same time, the
product friction factor(fRe) increased with (GR) and (Ar)increased and (Re )decrease.
Comparison of the result with the previous work shows a good agreement
Infrastructure projects take a long time, are complex, multidisciplinary, use different materials and products, and have high risk. These characteristics affect the process of supplying materials. The current paper studies the ability to improve the supply chain process and decrease its cost by identifying the factors that affect it. These factors are used as variables in the mathematical model, which is working under uncertain conditions when the consumption rate of materials is not constant. The information used in this model is obtained from Building Information Modeling (BIM) and Geographical Information System (GIS) techniques and the genetic algorithm is utilized to determine the optimal supplier and the quantities of supplies
... Show MoreFormation of emulsions during oil production is a costly problem, and decreased water content in emulsions leads to increases productivity and reduces the potential for pipeline corrosion and equipment used. The chemical demulsification process of crude oil emulsions is one of the methods used for reducing water content. The demulsifier presence causes the film layer between water droplets and the crude oil emulsion that to become unstable, leading to the accelerated of water coalescence. This research was performed to study the performance of a chemical demulsifier Chimec2439 (commercial) a blend of non-ionic oil-soluble surfactants. The crude oils used in these experiments were Basrah and Kirkuk Iraqi crude oil. These
... Show MoreThis study included a survey and review of the scientific names of the marsh insects (aquatic and surrounding it) for the purpose of unifying and updating the database.
The survey reveals 109 species under 77 genera that belong to 32 families and 7 orders as follow: Coleoptera (44 species), Diptera (7 species) Ephemeroptera (2 species), Hemiptera (14 species), Hymenoptera (11 species), Lepidoptera (2 species) and Odonata with 29 species.
Information of specimens' collection for each species, synonyms and geographical distribution were provided.
The typographical elements work significantly in engaging a recipient and attracting his attention to the idea and content of the printed work with all its types and goals for which<br /> it is designed. This is because of the fact that the typographical elements have tremendous expression capabilities that reflect the content of the artistic work in a simple way without any complexities. These elements have a special effect in achieving a clear, readable design, besides their effective contribution to the reception and understanding of the designs by the recipient. Accordingly, the designs of the electronic advertisement poster with their promoting goals of its products are considered among the graphic achieveme
... Show MoreA 2D geological model for Mauddud Formation in the Badra oil field is built using Rockworks 16 software. Mauddud Formation produces oil from limestone units; it represents the main reservoir in the Badra oil field. Six wells (BD-1, BD-2, BD-4, BD-5, P-15, and P-19) are selected to build facies and petrophysical (Porosity and Water saturation) models. Wells data are taken from the core and cutting samples and studied through the microscopic. The petrophysical data (effective porosity and water saturation) are derived from computer processes interpretation results that are calculated by using Interactive Petrophysics software. The 2D models are built to illustrate the vertical and horizontal distribution of petrophysical properties between we
... Show MoreThe movement is considered one of the important factors which attracts the receiver attention in designing artificial works in general, and especially in the advertisements, moreover the subject of the movement in the designing advertisements needs more care and study by the scholars. From this importance and from reaching to the basic streams of the research topic (the effect of the movement in the graphic design) the problem of the research has been set according to the following wonder:
- What is the designing process that establishes the movement in the commercial advertisements designs?
The researche
... Show MoreGod Almighty has imposed on us obligations and set limits on us, and among these obligations is the prayer, which is considered a pillar of Islam. And recently on the statement of its importance, and through extensive explanations, they elaborated on the statement of its pillars, its obligations, its Sunnahs, its rituals, and its bodies, and it is known that the imam in prayer is an important part of the parts of prayer. Whoever assumes this responsibility must be aware of these conditions, the most important of which is jurisprudence in religion, and there has been a disagreement between the jurists, especially the owners of the four schools of thought, about who is qualified to lead the imamate, and this is within many and wide details
... Show MoreEducation is the most powerful and important weapon in fighting poverty and unemployment because it provides students with new skills that appropriate the new market requirements and fair distribution of natural resources. It also transfers knowledge, skills, and ethics over generations. Education aims to create effective leaders who go under training and rehabilitation process, create a new human and instill faith, generate the creativity and innovation, and keep abreast with scientific process, updating curriculum, and finally, applying the technical education
A lab-scale packed Bio film reactor was used for ethanol production by fermentation of sugar solution using a local
isolated yeast saccharomyces cerevisia and glutaraldelryde on gelating as a covalent bounding agent. In this study four
types of packing in the reactor were used. They are; polypropylene mesh, glass rashig rings, ceramic rashig rings and
glass beads. Glucose solutions were used as substrate with four concentrations; (5, I 0, I 5, 20 g/l). Results show that the
ethanol productivity was increase with increasing sugar concentration. Also it was found that polypropylene mesh
packing give the highest productivity while glass beads gives the lowest productivity. The experiments were conducted at
three temperatur
International law has proven that it is an evolving and flexible law over the years, and despite that, this development takes a very long time, as the concept of peremptory norms took 83 years to crystallize and have concrete and impactful applications, and within this development another modern concept emerged, which is the obligations Erga Omnes in the Barcelona Traction case 1970. We have concluded that these two concepts fall under a broader concept, which is peremptory norms, and this concept represents the common supreme interests of the international community, and consists of rules that transcend all other rules in international law, and it is not permissible to derogate or deviate from them. On the other hand, it bears the oblig
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