The effect of time (or corrosion products formation) on corrosion rates of carbon steel pipe in aerated 0.1N NaCl
solution under turbulent flow conditions is investigated. Tests are conducted using electrochemical polarization
technique by determining the limiting current density of oxygen reduction in Reynolds number range of 15000 to 110000
and temperature range of 30 to 60oC. The effect of corrosion products formation on the friction factor is studied and
discussed. Corrosion process is analyzed as a mass transfer operation and the mass transfer theory is employed to
express the corrosion rate. The results are compared with many proposed models particularly those based on the
concept of analogy among momentum, heat, and mass transport. The capability of these models to predict corrosion
rates in presence of corrosion products is examined and discussed. It is found that formation of corrosion products with
time decreases the corrosion rate (or mass transfer rate) at low Reynolds number and temperature while it increases the
corrosion rate at high Re and temperature. It increases momentum transport and this increase depends on temperature,
Reynolds number, and corrosion rate. Increasing roughness due to the formation of corrosion products causes
overestimation of analogy correlations results by increasing friction factor and decreasing corrosion rate.
In this study, a three-dimensional finite element analysis using ANSYS 12.1 program had been employed to simulate simply supported reinforced concrete (RC) T-beams with multiple web circular openings subjected to an impact loading. Three design parameters were considered, including size, location and number of the web openings. Twelve models of simply supported RC T-beams were subjected to one point of transient (impact) loading at mid span. Beams were simulated and analysis results were obtained in terms of mid span deflection-time histories and compared with the results of the solid reference one. The maximum mid span deflection is an important index for evaluating damage levels of the RC beams subjected to impact loading. Three experi
... Show MoreThere is an interesting potential for the use of GFRP-pultruded profiles in hybrid GFRP-concrete structural elements, either for new constructions or for the rehabilitation of existing structures. This paper provides experimental and numerical investigations on the flexural performance of reinforced concrete (RC) specimens composite with encased pultruded GFRP I-sections. Five simply supported composite beams were tested in this experimental program to investigate the static flexural behavior of encased GFRP beams with high-strength concrete. Besides, the effect of using shear studs to improve the composite interaction between the GFRP beam and concrete as well as the effect of web stiffeners of GFRP were explored. Encasing the GFRP
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This research aims to assess the practice of physical activities by people with intellectual disabilities and its challenges during the Coronavirus (COVID-19) pandemic from their families' point of view. The research sample consisted of (87) individuals from families with intellectual disabilities in the Makkah region. The sample was selected by the simple random method where the researcher used the descriptive analytical approach. A questionnaire of (32) items was used as the research tool to collect data. The findings of the study showed that the assessment level of practicing physical activities by people with intellectual disabilities was low. The public facilities dimension ranked first with a moder
... Show MorePermeability estimation is a vital step in reservoir engineering due to its effect on reservoir's characterization, planning for perforations, and economic efficiency of the reservoirs. The core and well-logging data are the main sources of permeability measuring and calculating respectively. There are multiple methods to predict permeability such as classic, empirical, and geostatistical methods. In this research, two statistical approaches have been applied and compared for permeability prediction: Multiple Linear Regression and Random Forest, given the (M) reservoir interval in the (BH) Oil Field in the northern part of Iraq. The dataset was separated into two subsets: Training and Testing in order to cross-validate the accuracy
... Show MoreThis paper presents a new approach to discover the effect of depth water for underwater visible light communications (UVLC). The quality of the optical link was investigated with varying water depth under coastal water types. The performance of the UVLC with multiple input–multiple output (MIMO) techniques was examined in terms of bit error rate (BER) and data rate. The theoretical result explains that there is a good performance for UVLC system under coastal water.
The study aimed to identification the effect of brainstorming in linguistically grow of garten child the sample of study is composed from (48)male and female children have been distributed for two groups,one of them is experimental and another is disciplined for every per of garten and pre education,and they have been awarded in a number of variations. For measuring the subordinate variation(linguistically grow)the researcher prepared ascale for this purpose that consist of two parts:the first part the scale of linguistically grow of garten child(4-5 years)and the second part the scale of linguistically grow of pre education child (5-6 years).Consist of every one from (20)shapes of linguistically grow shapes for garten chil
... Show MoreThe present work aimed to investigate the neuraminidase (nan1) gene expression in 32 different clinical isolates of Pseudomonas aeruginosa to explore the role of the enzyme in different types of infection and might give a better understanding of host cell-pathogens interaction. In addition, the effect of monosaccharide D-mannose on neuraminidase gene expression in eight isolates was studied by utilizing a reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The results demonstrated that the highest expression of nan1 gene was in otitis samples (208,913.81) which were significantly higher than that from other infections (P < 0.01). While, the concentrations of gene copies obtained from urin
... Show MoreCarbamazepine (CBZ) is a narrow therapeutic index drug used in the treatment of trigeminal neuralgia and psychiatric disorders. Valerian (VAL) is a popular herbal product which should be prescribed to treat insomnia and anxiety. The study was designed to investigate the presence of significant pharmacokinetic (PK) interaction between Valerian (VAL) at different concentrations on Carbamazepine (CBZ) pharmacokinetic parameters in healthy male rabbits. In an in vivo, parallel-randomized controlled trial, the rabbits in three groups "first (control), second and third" were given oral doses of CBZ (50 mg/kg), for "second and third" groups (as test groups) rabbits were given (20 and 40 mg/kg/day) of the VAL respectively, as suspensi
... Show MoreBearing capacity of a concrete pile in fine grained cohesive soils is affected by the degree of saturation of the surrounding soil through the contribution of the matric suction. In addition, the embedded depth and the roughness of the concrete pile surface (expressed as British Pendulum Number BPN) also have their contribution to the shear strength of the concrete pile, consequently its bearing capacity. Herein, relationships among degree of saturation, pile depth, and surface roughness, were proposed as a mathematical model expressed as an equation where the shear strength of a pile can be predicted in terms of degree of saturation, depth, and BPN. Rel
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