A numerical investigation of mixed convection in a horizontal annulus filled with auniform fluid-saturated porous medium in the presence of internal heat generation is carried out.The inner cylinder is heated while the outer cylinder is cooled. The forced flow is induced by thecold outer cylinder rotating at a constant angular velocity. The flow field is modeled using ageneralized form of the momentum equation that accounts for the presence of porous mediumviscous, Darcian and inertial effects. Discretization of the governing equations is achieved usinga finite difference method. Comparisons with previous works are performed and the results showgood agreement. The effects of pertinent parameters such as the Richardson number and internalRayleigh number on the flow and heat transfer characteristics are considered in the present study.The obtained results depict that the Richardson number plays a significant role on the heattransfer characterization within the annulus. The present results show that an increase inReynolds number has a significant effect on the flow patterns within the annulus. Categorizationof the flow and isotherms regimes is established for various Richardson numbers (PDF) Convection Heat Transfer in Horizontal Annulus Porous Media with Rotating Outer Cylinder. Available from: https://www.researchgate.net/publication/320934745_Convection_Heat_Transfer_in_Horizontal_Annulus_Porous_Media_with_Rotating_Outer_Cylinder [accessed Mar 29 2024].
Background: Polymethylmethacrylate (PMMA) has relatively unsatisfactory mechanical properties such as low flexural strength and impact strength also dimensional instability. Material and method: Zirconium silicate nanoparticles were coated with a layer of trimethoxysilylpropylmethacrylate (TMSPM) before sonication in monomer (MMA) with the percentages 1% and 1.5% by weight then mixed with powder using conventional procedure, (150) samples were prepared and divided into three groups, each group consisted of (50) samples, the first group prepared from PMMA without addition (control), another group with the addition of 1% wt Zrsio4 nanoparticles (experimental) and the third one with 1.5% wt Zrsio4 nanoparticles (experimental). Each group
... Show MoreBackground: Heat-cured poly (methyl methacrylate) the principal material for the fabrication of denture base have a relatively poor mechanical properties. The aim of this study was to investigate the effect of glass flakes used as reinforcement on the surface hardness and surface roughness of the heat-processed acrylic resin material. Material and method: Glass flakes (product code: GF002) pretreated with silane coupling agent were added to Triplex® denture base powder using different concentrations. A total of 100 specimens of similar dimensions (65 x 10 x 2.5) mm were prepared, subdivided into 2 main groups of 50 specimens for each of the study tests. Ten specimens for the control group and 40 specimens for each of the experimental gro
... Show MoreBackground: Denture fracture is one of the most common problems encountered by the patients and prosthodontists. The objective of present study was to evaluate the transverse strength of nylon denture base resin repaired by using conventional heat polymerized, autopolymerized and visible light cure {VLC} resins, surface treatment that used for repair and adjustment of insufficient nylon denture bases and in case of addition of artificial teeth. As these corrective procedures are common chair side procedures in dental clinic. Materials and methods: One hundred twenty nylon specimens were prepared by using metal patterns with dimension of (65x10x2.5 mm) length, width, and thickness respectively for transverse strength test while for tensile b
... Show MoreBackground: Polymethyl methacrylate (PMMA) is the most commonly used material in denture fabrication. The material is far from ideal in fulfilling the mechanical requirements. Midline fracture; poor thermal conductivity and water sorption, are common problem in this material. The purpose of this study was to evaluate the effect of addition of surface treated Aluminum oxide nano fillers on some properties of heat cured (PMMA). Materials and methods: In addition to controlled group of heat cured PMMA the silanized (Al2O3) nanoparticles was added to PMMA powder by weight in three different percentages 1wt%, 2wt% and 3wt%, mixed by probe ultra-sonication machine. 200 specimens were constructed and divided into 5 groups according to the test (e
... Show MoreThe study aimed to establish the association of miR-153-3p expression with treatment response to IM in CML patients. Sixty CML patients were included and divided into two groups consistent with their response to treatment whether sensitive or resistant to IM. Ten healthy normal participants were enrolled as control group. RNA was extracted from serum to work out miR-153-3p expression utilizing real-time quantitative reverse transcription polymerase chain reaction. The primers were supplied by Macrogen Inc. Twenty seven patients were sensitive to imatinib and 33 were resistant to imatinib. The ratio of male to female was 1.14:1. The bulk (58%) of patients were within the age range of 41-60 years. Weight and gender did not significantly diffe
... Show MoreBackground: migraine is a chronic neurovascular disorder characterized by intermittent attacks of sever headache with or without aura that can include various combinations of neurological, gastrointestinal tract (G.I.T), and autonomic changes, without evidence of primary structural abnormalities. The Autonomic nervous system involvement suggested by many symptoms and signs including nausea, diarrhea, constipation, coldness in the extremities, paroxysmal tachycardia and chest pain.
Objectives: To evaluate autonomic functions in patients with migraine and to clarify the autonomic dysfunction weather its sympathetic, parasympathetic, or combined. Also to assess the severity of this dysfunction and its relation to age, gender and type of
The UN organization is considered one of the most important organizations at the international level. It has accomplished multiple tasks and roles of many different issues and events that hit the developing and advanced world countries. It has performed a series of procedures and laws that have had an impact on ending the wars and conflicts that plagued some countries and continued for a period of time in the past. Moreover, it has improved the level of the international relations between a number of countries due to the problems and incidents took place between them. It has relied on finding solutions and treatments for humanitarian problems such as the preservation of the environment, preventing the spread of epidemics and diseases Thi
... Show MoreObjective: Pregnancy-induced hypertension (PIH) is a major pregnancy complication that leads to maternal mortality. Here, we have scrutinized the correlation between serum levels of hydrogen peroxide (H2O2) and superoxide dismutase (SOD) in PIH.Methods: Serum samples were collected from 80 Iraqi women (40 women with PIH as patients group, 20 normotensive pregnant women as a positive control, and 20 normotensive non-pregnant women as a negative control) all groups were diagnosed clinically.Results: Serum of H2O2 and SOD levels was measured for all studied groups. Results showed that there were no significant variances in age and gestational age distribution between all studied groups. Furthermore, result showed that the serum level o
... Show MoreHydrogen peroxide was determined by a new , accurate , sensitive and rapid method via continuous mode of FIA coupled with total luminescence measurement which include the chemiluminescence generated ,based on the oxidation of Luminol which is loaded on poly acrylic acid gel beads by hydrogen peroxide in presence of Cobalt (II) ion as a chemiluminescence catalyst and the fluorescence that was created by the insitu radiation of the released chemiluminescence light. Fluorescien molecule was used as an accepter fluorophore where it is irradiated internally and instantly by the generation of luminol chemiluminescence light as internal source for irradiation of fluorescien molecule (Fluorescence Energy Transfer (FRET) ) . It can easily give fl
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