This work examines numerically the effects of particle size, particle thermal conductivity and inlet velocity of forced convection heat transfer in uniformly heated packed duct. Four packing material (Aluminum, Alumina, Glass and Nylon) with range of thermal conductivity (from200 W/m.K for Aluminum to 0.23 W/m.K for Nylon), four particle diameters (1, 3, 5 and 7 cm), inlet velocity ( 0.07, 0.19 and 0.32 m/s) and constant heat flux ( 1000, 2000 and 3000 W/ m 2) were investigated. Results showed that heat transfer (average Nusselt number Nuav) increased with increasing packing conductivity; inlet velocity and heat flux, but decreased with increasing particle size.Also, Aluminum average Nusselt number is about (0.85,2.
... Show MoreCocrystallization is an emerging approach for improving physico-chemical characteristics of an active pharmaceutical ingredient (API) for instance dissolution rate, solubility, stability in addition to mechanical properties without affecting their therapeutic activity. It is of great importance when other approaches like salt or polymorph formation do not encounter the estimated targets. In this review article, an outline of pharmaceutical cocrystals will be presented, with highlighting on factors affecting cocrystallization which include ∆pKa, donors and acceptors hydrogen bonds, molecular recognition point, synthon forming functional groups flexibility, dicarboxylic acid coformers carbon chain length and solvent effe
... Show MoreCarbon Fiber-Reinforced Polymer (CFRP) bars have several advantages over traditional steel reinforcement, including low density, erosion resistance, and higher tensile strength. The ACI 440.11-22 code permits CFRP as reinforcement; however, there are limited experimental studies on its application in Reinforced Concrete (RC) columns under combined loads. This study utilized theoretical analysis and Finite Element Analysis (FEA) to investigate 25 square slender concrete columns (kL/r = 17) affected by concentric and eccentric loads, examining variables, like CFRP bar contribution, eccentricity-to-depth ratio, and reinforcement arrangement. The results demonstrated CFRP's effectiveness in these columns, with failure modes varying from
... Show MoreThe present search aims to develop a test for selective attention, cognitive load and thinking mistakes and measuring these concepts among Baghdad university students. To make a comparison between the selective attention, cognitive load, and the mistakes of thinking among students in term of gender. To identify the relationship among the selective attention, cognitive load and the mistakes of thinking of university students. To achieve these purposes, the searcher has developed a test for selective attention, cognitive load, and the mistakes of thinking. Then, these tools were applied to a sample of (200) university students were selected from (21) college. The researcher used t-test of one sample, t-test of two independent
... Show MoreSulphated zirconia (SZ) is one of the most important solid acid catalysts was synthesize at different operating conditions, different calcination temperature and sulfonating time has been used. The prepared catalyst was distinguished by X-ray Diffraction (XRD), particle size and morphology of catalyst were checked by atomic force microscopy (AFM) and scanning electron microscopy (SEM) respectively, in addition to analysis by (DTA) Differential thermally and Energy Dispersive X-Ray (EDX). Finally, the N2 adsorption-desorption was used to measure the surface area (BET) and pore volume. High degree of tetragonal crystallinity was obtained 90 %, and surface area of 169 m2/g and pore volume of 0.39 cm3g-1 at 600°C calcination temperature for 3
... Show MoreThe growing population and the rising standard of living in cities as well as the increased commercial, industrial and agricultural activities around the world led to
massive production of waste containing different materials and one of them is the municipal solid waste (MSW), so there is a major problem facing the cities around the world about the waste, how to collect, transfer it and how to discard it. Because the accumulation of wastes, whether in the city alleys or in its squares and especially in its residential areas affect the health of their populations besides this situation will be a major indication of the deteriorating quality of life in the city, as hygiene considered a fundamental criterion for the city beauty as well
Two different polyvinyl alcohol/polyvinyl chloride (PVA/PVC) hollow fiber composite nanofiltration membranes were prepared after PVC hollow fiber membranes were coated using dip-coating method with PVA aqueous solution, which was composed of PVA, fatty alcohol polyoxyethylene ether (AEO9), and water [PVA/AEO9/water (4:0.5:95.5) wt%]. Effect of two different PVC hollow fiber immersion times in coating solution were studied. Cross-section, internal and external surfaces of the PVC hollow fibers and PVA/PVC composite nanofiltration membranes structures were characterized by scanning electron microscopy (SEM), pure water permeation flux and solutes rejection. It was found that, the coating layer thickness on the outer surface of the 19 wt% P
... Show MoreThe simulation is the oldest theory in art, since it appeared in the Greek aesthetic thought of the philosopher Plato, as we find in many of the thinkers and philosophers over a wide period of time to reach our world today. Our fascination with art in general and design art in particular is due to the creativity and innovations of the artist through the simulation, as well as the peculiarities in this simulation, which give objects signs and signals that may have an echo that sometimes does not exist in their physical reality.
The real representation of life and design construction, descriptions of the expression of each of them in the form of intellectual construction and the ideas of producti
... Show MoreThe primary focus of the study factor reverse polymerization styrene polymer kinetics and distribution weight Aljaia in Blma Aldhur free reverse The study was conducted wi Mamahakah and using the Monte Carlo method