This study presents an investigation about the effect of fire flame on the punching shear strength of hybrid fiber reinforced concrete flat plates. The main considered parameters are the fiber type (steel or glass) and the burning steady-state temperatures (500 and 600°C). A total of 9 half-scale flat plate specimens of dimensions 1500mm×1500mm×100mm and 1.5% fiber volume fraction were cast and divided into 3 groups. Each group consisted of 3 specimens that were identical to those in the other groups. The specimens of the second and the third groups were subjected to fire flame influence for 1 hour and steady-state temperature of 500 and 600°C respectively. Regarding the cooling process, water sprinkling was applied directly after the burning stage to represent the sudden cooling process. Generally, the obtained results exhibited a significant increase in the punching shear capacity of the fiber-reinforced slabs as compared to the corresponding no fiber-reinforced slabs even at elevated burning temperatures 600°C. The ultimate load was increased by about 16.6, 19, and 21.5% at temperatures of 25, 500, and 600°C respectively, for steel fiber reinforced slabs and by about 13.9, 27.2, and 34.6% for slabs containing two mixed types of fibers (steel and glass), as compared with the reference specimen at the same temperatures respectively. In addition, the results indicated that fibers' presence in concrete resulted in gradually punching failure with more ductile mode, whereas the failure was sudden with a brittle mode in the slabs that did not contain fibers.
A mercury porosimeter has been used to measure the intrusion volume of the three types mercury positive lead acid-battery plates. The intrusion volumes were used to calculate the pore diameter, pore volume, pore area, and pore size distribution. The variation of the pore area in positive lead acid-battery plates as well as of the pore volume has the following sequence. Paste positive > Uncured positive > Cured positive
A mercury porosimeter has been used to measure the intrusion volume of the three types mercury positive lead acid-battery plates. The intrusion volumes were used to calculate the pore diameter, pore volume, pore area, and pore size distribution. The variation of the pore area in positive lead acid-battery plates as well as of the pore volume has the following sequence. Paste positive > Uncured positive > Cured positive
The main objective of this study is to introduce a systematic design procedure for short-span segmental beams following a sophisticated ACI 440.2R-17 design procedure. The general aspects of innovative short-span segmental beams are easy to fabricate, economical and rapidly placed in pre-specified positions. Short-span segmental beams fabricated from individual precast plain-concrete blocks and CFRP plates. Recently, experimental tests performed on short-span segmental beams, by the authors, investigated CFRP plate-bonding, CFRP plate cross-sectional area, the thickness of plate-bonding epoxy resin, surface-to-surface condition of concrete blocks, as well as, interface condition of the bonding surface. The experimental program comprises tes
... Show MoreFor a given loading, the stiffness of a plate or shell structure can be increased significantly by the addition of ribs or stiffeners. Hitherto, the optimization techniques are mainly on the sizing of the ribs. The more important issue of identifying the optimum location of the ribs has received little attention. In this investigation, finite element analysis has been achieved for the determination of the optimum locations of the ribs for a given set of design constraints. In the conclusion, the author underlines the optimum positions of the ribs or stiffeners which give the best results.
Due to the large population of motorway users in the country of Iraq, various approaches have been adopted to manage queues such as implementation of traffic lights, avoidance of illegal parking, amongst others. However, defaulters are recorded daily, hence the need to develop a mean of identifying these defaulters and bring them to book. This article discusses the development of an approach of recognizing Iraqi licence plates such that defaulters of queue management systems are identified. Multiple agencies worldwide have quickly and widely adopted the recognition of a vehicle license plate technology to expand their ability in investigative and security matters. License plate helps detect the vehicle's information automatically ra
... Show MoreThis study experimentally investigated Free-Fall Gravity Drainage (FFGD) under combination-drive conditions in a two-dimensional Hele-Shaw model representing a water-drive reservoir. An initially high gravity potential from the oil column enabled early oil drainage before aquifer support became dominant. Three water-drive strengths were tested, demonstrating that a stronger aquifer (1.15 psig) accelerated oil recovery to approximately 75% of the original oil in place (OOIP) within 60 minutes, resulting in a final recovery of 79.5%. However, this was accompanied by rapid water breakthrough after 2.5 minutes and high-water cuts exceeding 90%. In contrast, a weaker aquifer (0.725 psig) stabilized the oil–water contact, delaying w
... Show MoreVitamin D is one of several nutrients essential for calcium metabolism. Body weight status and magnesium may influence vitamin D activity. To determine whether salivary vitamin D, magnesium, and calcium levels are associated with body weight status and dental caries severity in children, this cross‐sectional research was conducted.
The sample consisted of 180 boys aged 6–8 years. According to their body mass index (BMI), children were assigned to three groups of 60 boys (normal weight, overweight, and obese). Moreover,
Background: Osteoporosis is a systemic skeletal disorder that has an impact on general health, dental health and salivary composition. The mineralization of teeth happens simultaneously with that of the skeleton, but if mineral metabolism is disrupted, tooth failures will resemble those that affect bone tissue. Vitamin D plays a key role in bone and tooth mineralization.
Objective: to evaluate the impact of osteoporosis on teeth decay in relation to salivary vitamin D among menopause in Baghdad city.
Subjects and Methods: This study was cross sectional study. The study group consists of
... Show More<span lang="EN-US">Proper employment of Hybrid Wind/ PV system is often implemented near the load, and it is linked with the grid to study dynamic stability analysis. Generally, instability is because of sudden load demand variant and variant in renewable sources generation. As well as, weather variation creates several factors that affect the operation of the integrated hybrid system. So this paper introduces output result of a PV /wind via power electronic technique; DC chopper; that is linked to Iraqi power system to promote the facilitating achievement of Wind/ PV voltage. Moreover, PSS/E is used to study dynamic power stability for hybrid system which is attached to an effective region of Iraqi Network. The hybrid system
... Show MoreThe sensitivity of SnO2 nanoparticles/reduced graphene oxide hybrid to NO2 gas is discussed in the present work using density functional theory (DFT). The SnO2 nanoparticles shapes are taken as pyramids, as proved by experiments. The reduced graphene oxide (rGO) edges have oxygen or oxygen-containing functional groups. However, the upper and lower surfaces of rGO are clean, as expected from the oxide reduction procedure. Results show that SnO2 particles are connected at the edges of rGO, making a p-n heterojunction with a reduced agglomeration of SnO2 particles and high gas sensitivity. The DFT results are in