The inhibitive action of a blend of sodium nitrite/sodium hexametaphosphate (SN+SHMP) on corrosion of carbon steel in simulated cooling water systems (CWS) has been investigated by weight loss and electrochemical polarization technique. The effect of temperature, velocity, and salts concentrations on corrosion of carbon steel were studied in the absence and presence of mixed inhibiting blend. Also the effect of inhibitors blend concentrations (SN+SHMP), temperatures, and rotational velocity, i.e., Reynolds number (Re) on corrosion rate of carbon steel were investigated using Second-order Rotatable Design (Box-Wilson Design) in performing weight loss and corrosion potential approach. Electrochemical polarization measurements were used to study the behavior of carbon steel in different salts concentrations of (CWS) with pH = 7.5 in absence and presence of the inhibiting blend. The results show that the regression model (Box-Wilson Design) that has been developed using experimental data was used to verify that the interaction term of temperature with inhibitors blend and the square term of inhibitors blend are significant for corrosion rate in 0.05 N NaCl solution while the main variables are not pronounced. Also, it is found that the corrosion rate of carbon steel is increased with increasing temperature, rotational velocity, and NaCl salts concentration in uninhibited and inhibited solutions. Inhibition performance of NaNO2+ Na(PO3)6 was found to increase with its concentration up to 800 ppm inhibitors blend, and the corrosion potential is shifted to more positive direction with increasing rotational velocity, and inhibitor blend concentration.
Two dimensional meso-scale concrete modeling was used in finite element analysis of plain concrete beam subjected to bending. The plane stress 4-noded quadrilateral elements were utilized to model coarse aggregate, cement mortar. The effect of aggregate fraction distribution, and pores percent of the total area – resulting from air voids entrapped in concrete during placement on the behavior of plain concrete beam in flexural was detected. Aggregate size fractions were randomly distributed across the profile area of the beam. Extended Finite Element Method (XFEM) was employed to treat the discontinuities problems result from double phases of concrete and cracking that faced during the finite element analysis of concrete beam. Crac
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This study aims at identifying thinking, its aspects, controls, thinker’s characteristics, and the attempts that followed by Ibrahim’s people. This was achieved under Ibrahim’s story, (peace and blessing be upon him), in the Holy Qur’an. The study used the descriptive method through induction and deduction. The study reached the following results: thinking is an organized reasonable human action, which includes all human life in the fields of science, knowledge, and calling for Allah. It depends on remembering what is already in the memory and it should be subjected by revelation and Islamic legislation. The study illustrated that the most important thinking controls are monotheism, piety, Islamic legislation, the Holy Qur’an,
... Show MoreThis paper presents a study to investigate the behavior of post-tensioned segmental concrete beams that exposed to high-temperature. The experimental program included fabricating and testing twelve simply supported beams that divided into three groups depending on the number of precasting concrete segments. All specimens were prepared with an identical length of 3150 mm and differed in the number of the incorporated segments of the beam (9, 7, or 5 segments). To simulate the genuine fire disasters, nine out of twelve beams were exposed to a high-temperature flame for one hour. Based on the standard fire curve (ASTM – E119), the temperatures of 300◦C (572◦F), 500◦C (932◦F), and 700◦C (1292◦F) were adopted. Consequently,
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This research shows the experimental results of the bending moment in a flexible and rigid raft foundation rested on dense sandy soil with different embedded depth throughout 24 tests. A physical model of dimensions (200mm*200mm) and (320) mm in height was constructed with raft foundation of (10) mm thickness for flexible raft and (23) mm for rigid raft made of reinforced concrete. To imitate the seismic excitation shaking table skill was applied, the shaker was adjusted to three frequencies equal to (1Hz,2Hz, and 3Hz) and displacement magnitude of (13) mm, the foundation was located at four different embedment depths (0,0.25B = 50mm,0.5B = 100mm, and B = 200mm), where B is the raft width. Generally, the maximum bending
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Everywhere carriers incur a measure of liability for the safety of the goods. Carriers are liable for any damage or for the loss of the goods that are in their possession as carriers unless they prove that the damage or loss is attributable to certain excepted causes. Damaged and lost items can unfortunately be a common problem when shipping freight. Legal responsibilities arise due to loss or damage during transit while cargo is in their care. This study intends to investigate the nature of the liability of the maritime carrier when this liability is realized, and the extent to which it can be paid or disposed of given the risks realized from the transportation process, which may result in damage or loss of the goods, and the damag
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This paper introduces an experimental study on the behavior of confined concrete filled aluminum tubular (CFT) column to improve strength design, ductility and durability of concrete composite structures under concentrically loaded in compression to failure. To achieve this: seven column specimens with same concrete diameter 100mm and without steel reinforcement have been examined through experimental testing, which are used to study the effects of the thickness of the aluminum tube encased concrete ( thickness : 0mm, 2mm, 3mm, 4mm and 5mm with same length of column 450mm), length of column (thickness 5mm and length of column 700mm) and durability (thickness 5mm and length of column 450mm) on the structural behavior of &
... Show MoreObjectiveIs to study the causes of bloody diarrhea in in (50)cases (37%) , Shigella spp in (25) cases (18% and
children under five years of age and to clarify their relations Campylobacter jejuni Icases only (0.75%)
to the type offood and mothers educational level ConciusionBloody diarrehea is common in children under
methods Ahospital based study was carried out at tikreet 5years age who were admitted to Tikreet Teaching Hospital
teaching Hospital in Tikreet city on 133 children who were in Tikreet city , There is astrong positive relationship
admitted to the hospital with bloody diarrehea their ages between the occurrence of bloody diarrehea and the type of
range between one month -5years. The period study is from foo