This work concerns the thermal and sound insulation as well as the mechanical properties of polymer matrix composite reinforced with glass fibers. These fibers may have dangerous effect during handling, for example the glass fibers might cause some damage to the eyes, lungs and even skin. For this reason the present work, investigates the behavior of polymer composite reinforced with natural fibers (Plant fibers) as replacement to glass fibers. Unsaturated Polyester resin was used as matrix material reinforced with two types of fibers, one of them is artificial (Glass fibers) and the other type is natural (Jute, Fronds Palm and Reed Fibers) by hand lay-up technique. All fibers are untreated with any chemical solvent. The Percentage of mixing was (90 wt. %) of the matrix while the weight fraction of each type of fibers was fixed (10 wt. %). The mechanical tests included impact and flexural strength tests. The results showed that the impact strength and flexural strength of the composites reinforced with Jute fibers is higher than that of Glass fibers and other natural fibers. The coefficients of thermal conductivity of the composites were measured by Lee's disc apparatus, the results show that the thermal insulation of the composite reinforced with jute fibers is higher than that of glass fibers and other natural fibers. The acoustic insulation of the composites reinforced with Jute fibers showed excellent result in insulation compared with glass fibers and other natural fibers.
The use of essential services in modern constructions, such pipes, and ducts, became important, placing these pipes and ducts underneath the soffit of the beam. They made a ceiling sandwich, and that causes to reduce the height of the floor, so the presence of the opening in the beam saves the height of the floor. In this paper, the investigation of the beam response of reinforced concrete simply supported rectangle beams with square web openings is presented, including a number of the web openings (two, four, and eight), in addition to its use in strengthening the member at the openings (when the beam is planned before casting, internal deformation steel bar is used, and in case of the opening is existing in the b
... Show MoreHeat transfer process and fluid flow in a solar chimney used for natural ventilation are investigated numerically in the present work. Solar chimney was tested by selecting different positions of absorber namely: at the back side, front side, and at the middle of the air gap. CFD analysis based on finite volume method is used to predict the thermal performance, and air flow in two dimensional solar chimney under unsteady state condition, to identify the effect of different parameters such as solar radiation. Results show that a solar chimney with absorber at the middle of the air gap gives better ventilation performance. A comparison between the numerical and previous experimental results shows fair agreement.
KE Sharquie, WS Al-Dori, IK Sharquie, AA Al–Nuaimy, Hospital, 2004 - Cited by 20
Land snails constitute an important group of mollusks distributed worldwide. This study reports on land snails found in Iraq. A survey of terrestrial gastropods was performed during their activity seasons in gardens, agricultural lands and nurseries in Iraq from March 2022 to September 2023. Fifteen terrestrial snails belonging to seven families were documented. The species Euchondrus michonii (Bourguignat, 1853) was identified and recorded based on several distinct conchological characters for the first time in Iraq. The recently collected specimens, along with those previously recorded in Iraq, were included in this checklist. Essential information on each species is also presented. As there is no previous checklist or study that
... Show MoreS Khalifa E, N Adil A, K Nabeel O…, 2008
Infection of the gastric mucosa with Helicobacter pylori is strongly associated with chronic gastritis, peptic ulcer and gastric cancer. Helicobacter pylori virulence factors include a variety of proteins that are involved in its pathogenesis, such as VacA and CagA. Another group of virulence factors is clearly important for colonization of H.pylori in the gastric mucosa. These include urease, motility factors (flagellin), and Superoxide dismutase (SOD). Because of this organism's microaerophilic nature and the increased levels of reactive oxygen in the infected host, we expect that other factors involved in the response to oxidative stress are likely to be required for virulence. Superoxide dismutase is a near
... Show MorePotential health and environmental effects of nanoparticles need to be thoroughly assessed before their widespread commercialization. The present investigation was planned with the aims to determine the effects of gold nanoparticles (GNPs) on blast (BI) and mitotic (MI) indices of cultured lymphocytes. The results revealed that BI (50.3±2.3, 30.2±1.9, 10.5±0.7 and 0.0%, respectively) and MI (70.1±2.9, 20.4±1.1, 5.3±0.1 and 0.0%, respectively) showed a gradual decreased percentage as the concentration of GNPs was increased from 0.085 to 0.66 µg/mL, and the difference was significant compared to control culture (81.6±2.5 and 90.2±3.7%, respectively). A maximum inhibition of BI and MI was occurred at the concentration 0.66 µg/mL. In
... Show MoreStatement of the Problem. The use of orthodontic fixed appliances may adversely affect oral health leading to demineralizing lesions and the development of gingival problems. Aims of the Study. The study aimed to coat orthodontic archwires with chlorhexidine hexametaphosphate nanoparticles (CHX-HMP NPs) and to evaluate the elusion of CHX from CHX-HMP NPs. Materials and Methods. A solution of CHX-HMP nanoparticles with an overall concentration of 5 mM for both CHX and HMP was prepared, characterized (using atomic force microscope and Fourier transformation infrared spectroscopy), and used to coat orthodontic stainless steel (SSW) and NiTi archwires (NiTiW). The coated segments were characterized (using scanning electron microscopy
... Show MoreA numerical method is developed to obtain two-dimensional velocity and pressure distribution through a cylindrical pipe with cross jet flows. The method is based on solving partial differential equations for the conservation of mass and momentum by finite difference method to convert them into algebraic equations. This well-known problem is used to introduce the basic concepts of CFD including: the finite- difference mesh, the discrete nature of the numerical solution, and the dependence of the result on the mesh refinement. Staggered grid implementation of the numerical model is used. The set of algebraic equations is solved simultaneously by “SIMPLE” algorithm to obtain velocity and pressure distribution within a pipe. In order to
... Show MoreIn this research we assumed that the number of emissions by time (𝑡) of radiation particles is distributed poisson distribution with parameter (𝑡), where < 0 is the intensity of radiation. We conclude that the time of the first emission is distributed exponentially with parameter 𝜃, while the time of the k-th emission (𝑘 = 2,3,4, … . . ) is gamma distributed with parameters (𝑘, 𝜃), we used a real data to show that the Bayes estimator 𝜃 ∗ for 𝜃 is more efficient than 𝜃̂, the maximum likelihood estimator for 𝜃 by using the derived variances of both estimators as a statistical indicator for efficiency