The use of Near-Surface Mounted (NSM) Carbon-Fiber-Reinforced Polymer (CFRP) strips is an efficient technology for increasing flexural and shear strength or for repairing damaged Reinforced Concrete (RC) members. This strengthening method is a promising technology. However, the thin layer of concrete covering the NSM-CFRP strips is not adequate to resist heat effect when directly exposed to a fire or at a high temperature. There is clear evidence that the strength and stiffness of CFRPs severely deteriorate at high temperatures. Therefore, in terms of fire resistance, the NSM technique has a significant defect. Thus, it is very important to develop a set of efficient fire protection systems to overcome these disadvantages. This paper presents a numerical study that investigates the fire behavior of thermally insulated RC beams flexurally strengthened with NSM-CFRP strips and subjected to fire exposure according to the ISO 834 standard. The numerical study considered three-dimensional finite element models in the ABAQUS software that have been developed to simulate and predict the performance (thermal and structural response) of fire endurance tests on strengthened, uninsulated strengthened, and thermally insulated beams strengthened with NSM-CFRP strips, which were exposed to fire and had different fire insulation schemes. The insulation used was plaster from local material with a thickness range of 25 to 50mm. The variation of the thermal and mechanical properties with the temperature of the constituent materials was considered. All beams' mechanical and thermal responses were adequately simulated using numerical models. The results of the numerical simulations were in good agreement with the experimental data. The fire behavior of the NSM-CFRP strengthened RC beams was examined and particularly the efficiency of the NSM strengthening system during the fire. The behavior in the fire of the NSM-CFRP strengthening system on the RC beams thermally protected with different fire insulation schemes was assessed. Finally, the effectiveness of fire insulation was studied.
Investigating the thermal and electrical gains and efficiencies influence the designed photovoltaic thermal hybrid collector (PVT) under different weather conditions. The designed system was manufactured by attaching a fabricated cooling system made of serpentine tubes to a single PV panel and connecting it to an automatic controlling system for measuring, monitoring, and simultaneously collecting the required data. A removable glass cover had been used to study the effects of glazed and unglazed PVT panel situations. The research was conducted in February (winter) and July (summer), and March for daily solar radiation effects on efficiencies. The results indicated that electrical and thermal gains increased by the incre
... Show MoreFounding a System to secure deposits and protecting the depositors is considered one of the important and exchanged subjects out there in the banking system/field in Iraq at the current time, and the reason behind the exchange and spread of this subject is due to the financial crisis of which the banking sector is suffering from and the stumbling of many banks, those factors have had led to the insecurity of the depositors and their mistrust towards banks, thus, it is necessary to create a system to secure deposits in which depositors would be compensated for the losses caused by the banks' failures. in addition, it could be a countermeasure system which maintains the banking stability, protects the rights of depositors and gains
... Show MoreBackground: This study was aimed to investigate the effect of three lingual button (Nickel free / rectangular base, Nickel free / round base and Composite) and bonding environment, wet and dry enamel surface, on: the shear bond strength (SBS) of light and self-cured Resin Modified Glass Ionomer Cements, and the debonding failure sites. Materials and method: One hundred twenty no-carious, free of cracks maxillary first premolar teeth were selected. Three types of orthodontic lingual buttons were used in this study: Nickel free / rectangular base, Nickel free / round base and Composite buttons. The teeth were divided into two groups of sixty teeth each. One group was used for testing the chemically cured GC Fuji Ortho Resin modified Glass Io
... Show MoreBackground: Nanoparticles are clusters of atoms in a size range from (1-100) nm. Nano dentistry creates amazing useful structures from individual atoms or molecules (nanoparticles), which provides a new alternative and a possibly superior strategy in prevention and treatment of dental caries through management of dental plaque biofilms. The aim of the study was to test the sensitivity of Streptococcus mutans to different concentrations of hydroxyapatite and iron oxide nanoparticles suspension solutions, in comparison to chlorhexidine, and de-ionized water, in vitro. Materials and methods: Agar well technique was applied to test the sensitivity of Streptococcus mutans to different concentrations of hydroxyapatite and iron oxide nanoparticle
... Show MoreOne of the costliest problems facing the production of hydrocarbons in unconsolidated sandstone reservoirs is the production of sand once hydrocarbon production starts. The sanding start prediction model is very important to decide on sand control in the future, including whether or when sand control should be used. This research developed an easy-to-use Computer program to determine the beginning of sanding sites in the driven area. The model is based on estimating the critical pressure drop that occurs when sand is onset to produced. The outcomes have been drawn as a function of the free sand production with the critical flow rates for reservoir pressure decline. The results show that the pressure drawdown required to
... Show MoreIn this work the corrosion behavior of Ti-6Al-4V alloy was studied by using galvanostatic measurements at room temperature in different media which includ sodium chloride (food salt), sodium tartrate (presence in jellies, margarine, and sausage casings,etc.), sodium oxalate (presence in fruits, vegetables,etc.), acetic acid (presence in vinegar), phosphoric acid (presence in drink), sodium carbonate (presence in 7up drink,etc.), and sodium hydroxide in order to compare.
Corrosion parameters were interpreted in th
... Show MoreAdaptive responses in larval behavior may be of two kinds: Taxis: This involves a change in direction relative to source of a stimulus. Kinesis: Kinesis has no directional component, but involves change in the rate of performance in response to a stimulus. Drosophila larvae exhibited flexible behavioral responses associated with food acquisition and selection for different environmental conditions. In this investigation, we are concerned explosively with kinetic responses to food viability. Third instar larvae were subjected to test for thirty minutes in each of the following conditions i) in distilled water, ii) in Ringer's solution, iii) in glucose solution and on live yeast suspension. In each case the larva was in a thin layer of solu
... Show MoreLogic in the philosophy of ethical behavior in business organizations