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 work, production of silicon metal at high purity of 99% by using Iraqi–starting materials (Iraqi sand and plant coal)was reported, electric arc–furnaces assembly was manufactured inside, the graphite electrodes were made from graphite scrap, this system is operate to produce about 800 gm /6hr of silicon metal to meet the need for manufacturing silicon oils, resins, solar cells, and electronic parts. The procedure, equipments and analysis data were described as well.
The world of Contemplations is a controversial concept among scholars, writers, thinkers and the public. The theory of the dialogue of souls indicates that souls communicate and think with each other despite the distances. Islamic studies have researched this concept, and this research paper aims to explain the concept of the world of Contemplations and what is the dialogue between God Almighty and the souls that God brought forth from the back of Adam and took from them the covenant and pledge to unify Him, and its effects on human life in this world. The researcher found that scholars and writers differ in proving the existence of the world of Contemplations despite the existence of examples of it in verses of the Holy Quran, and that the
... Show MoreThe authentic traditional architecture proved that it is very convenient to the environmental and social regulations where it appeared and lasted for hundred of years.
This traditional architecture got the intelligence in providing thermal comfort for their occupants by the intelligent usage of the building materials and the intelligent planning and designs which took in consideration the climatic condition and the aerodynamics of the whole city as one ecological system starting from the cold breeze passing through its narrow streets till it enters the dwelling units and glides out through the wind catchers.
This architecture had been neglected and replaced by modern imported architecture which had collap
... Show MoreBackground: Prosthodontists estimated the parallelism of the occlusal plane to different anatomical landmarks, which was somewhat arbitrary and depended mainly on their vision. The aim of this research was to assess the degree of accuracy of prosthodontists in determining the parallelism of two lines. This research was aimed to assess which technique would be more accurate for the prosthodontist to distinguish parallelism; the comparison of the occlusal plane with the interpupillary line or with the inferior border of the earlobes. Materials and methods: Twenty eight prosthodontic specialists were included in this research. Illustrations of two lines with different tilts were presented to the participants to distinguish whether parallel or
... Show MoreThe analysis, behavior of two-phase flow incompressible fluid in T-juction is done by using "A Computational Fluid Dynamic (CFD) model" that application division of different in industries. The level set method was based in “Finite Element method”. In our search the behavior of two phase flow (oil and water) was studed. The two-phase flow is taken to simulate by using comsol software 4.3. The multivariable was studying such as velocity distribution, share rate, pressure and the fraction of volume at various times. The velocity was employed at the inlet (0.2633, 0.1316, 0.0547 and 0.0283 m/s) for water and (0.1316 m/s) for oil, over and above the pressure set at outlet as a boundary condition. It was observed through the program
... Show MoreAmoxicillin is commercially available in the form of capsules and tablets containing 250mg or 500mg for oral administration. It is also available in the form of suspension containing "25mg/ml†. Amoxicillin is presently used as the most common antibiotics .Ten healthy Human volunteers were characterized respected to their pharmacokinetic and bioavailability of two formulations of Amoxicillin from two sources of industrial companies after a single dose administration was given orally. A procedure is described for determination the concentration levels of Amoxicillin in human plasma of healthy volunteers using high performance liquid chromatography (HPLC) with reversed-phase isocratic column at low wave length of UV-visib
... Show MoreThe Cassia glauca Lam. is the tree that belongs to the Fabaceae family and is native to India has many uses in indigenous systems of medicine, folk medicine, and traditional Brazilian medicine. Has many pharmacological activities such as anti-diabetic, antibacterial, antifungal, antioxidant, anti-hemolytic, anticancer, cardio-protective, and Hepato-protection. The aim of study is to Isolation, identification, and quantification of some compounds from aerial parts of Cassia glauca since no phytochemical investigation had previously been done in Iraq for this plant. The aerial parts were defatted in n. hexane for 48 hours. The defatted materials were extracted in 85% ethanol using the hot method (soxhlet), then the extract was fra
... Show MoreThis study has applied the theoretical framework of conceptual metaphor theory to the analysis of the source and target domains of metaphors that are used in two English nineteenth century sonnets, both written by contemporaneous female poets. The quantitative and qualitative results of the textual analysis have clearly revealed that Elizabeth Barrett Browning’s sonnet 23 centres around the conceptual mapping of the journey of love and life with that of possession. In contrast, Christina Rossetti’s sonnet Remember tackles the central conceptual mapping of death as a journey in relation to its further experiential connections. In addition, the application of conceptual metaphor theory in identifying the frequencies and densities of metap
... Show MoreMany writers and scientists hardly differentiate between the two instruments of use
(If) and (if) to convergence in the meaning, as they perform the meaning of the penalty and condition, as the answer relates to his condition, but when linguistic meditation we find a great difference in use in terms of meaning, so this research came to reveal these meanings and was extrapolated applied in Surat al-Maidah By counting the verses in which (if) and (if) the cops were given and looking at their contexts, the connotation of the cops in most places was within the context of probability, which is the origin of its use, given in twenty places of Surat al-Ma'idah, and it had multiple connotations according to the contexts of the verses received