An experimental and numerical study was carried out to investigate the heat transfer by natural convection in a three dimensional annulus enclosure filled with porous media (silica sand) between two inclined concentric cylinders with (and without) annular fins attached to the inner cylinder under steady state condition. The experiments were carried out for a range of modified Rayleigh number (0.2 ≤Ra*≤ 11) and extended to Ra*=500 for numerical study and for annulus inclination angle of (δ = 0˚, 30˚, 60˚ and 90˚). The numerical study was to give the governing equation under assumptions that used Darcy law and Boussinesq’s approximation and then it was solved numerically using finite difference approximation. It was found that the average Nusselt number depends on (Ra*, Hf, δ and Rr ). The results showed that the increasing of the fin length increases the heat transfer rate for any fin pitch unless the area of the inner cylinder exceeds that of the outer one; then the heat will be stored in the porous media. A comparison was made between the results of the present work and those of other researches for the case without fins and excellent agreement was obtained.
The present work aims to study the efficiency of coagulation/ flocculation as 1st stage, natural gravity water filter or microfiltration (MF) as 2nd stage and nanofiltration (NF) technology as final stage for treatment of water of main outfall drain (MOD) for injection in Nasiriyah oil field. Effects of operating parameters such as coagulant dosage, speed and time of slow mixing step and settling time in the 1st stage were studied. Also feed turbidity and total suspended solids (TSS) in the 2
... Show More
(13)
(14)
Diese Forschungsarbeit versteht sich als ein Versuch zur Bestimmung einer der neuen Unterrichtsmethoden, die den Lernenden im Fach Deutsch besonders interessant vorkommen.Der Unterricht soll in einer Atmosphäre, die frei von Zeitdruck, Angst und Zensurdruck ablaufen lassen, damit werden die Studenten ermutigt, die Nutzung von Spiel zu ihrer eigenen Sache machen, um die Spielziele Spaß, Empathie, Zusammenarbeit und Kommunikation zu realisieren. Das Hauptlernziel des Fremdsprachenunterrichts ist es, Lernenden zu ermöglichen, in der Zielsprache zu kommunizieren.
Wir konzentrieren uns in diesem Beitrag auf eine wichtige sprachliche Fertigkeit, die den rezeptiven Fertigkeiten gehört, die ist das Hörverstehen.
Das Hörvers
... Show MoreThis study compared in vitro the microleakage of a new low shrink silorane-based posterior composite (Filtek™ P90) and two methacrylate-based composites: a packable posterior composite (Filtek™ P60) and a nanofill composite (Filtek™ Supreme XT) through dye penetration test. Thirty sound human upper premolars were used in this study. Standardized class V cavities were prepared at the buccal surface of each tooth. The teeth were then divided into three groups of ten teeth each: (Group 1: restored with Filtek™ P90, Group 2: restored with Filtek™ P60, and Group 3: restored with Filtek™ Supreme XT). Each composite system was used according to the manufacturer's instructions with their corresponding adhesive systems. The teeth were th
... Show MoreBacteriophage of E. Coli interspecies from sewage samples were isolated , the phage particles were isolated from two different sewage samples . The first sample was collected from sewage sample of Baghdad university and the second sample was isolated from domestic sewage sample , first sample showed phages specialized for three E. Coli interspecies bacteria (first plate ) and two E. Coli interspecies bacteria (second plate ) , meanwhile second sample showed phage specialized for two E. Coli. interspeciesThe study of appearance of E coli phages from first sample showed three types of E. coli phages with different size of inhibition zone ( 1 , 0.7,0.5 )Cm respectively ( first plate ) , meanwhile E. Coli interspecies bacteria showed phages
... Show More
Background: Invasion in oral cancer involves alterations in cell-cell and cell-matrix interactions that accompanied by loss of cell adhesion. Catenins stabilize cellular adherence junctions by binding to E-cadherin, which further mediates cell-cell adhesion and regulates proliferation and differentiation of epithelial cells. The Wnt/β-catenin pathway is one of the major signaling pathways in cell proliferation, oncogenesis, and epithelial-mesenchymal transition. Aims of the study: to detect immunohistochemical distribution pattern and different subcellular localization of β-catenin in oral squamous cell carcinoma and relate such expression to Bryne’s invasive grading system. Materials and Methods: This study included 30 paraffi
... Show More
(1)
Background: Obesity is a serious public health concern that has reached epidemic proportions; the prevalence, as well as the severity of obesity in adolescents is increasing at an alarming rate. A close relationship was found between weight status and dental caries. Thus this research aimed to assess the prevalence and severity of dental caries among overweight adolescent females in relation to physicochemical characteristics of stimulated whole saliva in comparison with normal weight adolescent females. Materials and methods: The total sample involved for nutritional status assessment is composed of 2678 females aged 13-15 years. This was performed using Body Mass Index specific for age and gender according to CDC growth chart (2000). The
... Show MoreThe corona virus epidemic outbreak has urged an extreme worldwide effort for re‐purposing obtainable approved medications for its treatment. In this review, we're focusing on the chemicals properties andpharmacologicaleffectiveness of medicationsofsmallmolecule that are presently being evaluated in clinical trials for the management of corona virus (COVID‐19). The current review sheds light on a number of drugs that have been diagnosed to treat COVID‐19 and their biological effects.