Corrosion- induced damage in reinforced concrete structure such as bridges, parking garages, and buildings, and the related cost for maintaining them in a serviceable condition, is a source of major concern for the owners of these structures.
Fly ash produced from south Baghdad power plant with different concentrations (20, 25 and 30) % by weight from the cement ratio were used as a corrosion inhibitor as a weight ratio from the cement content.
The concrete batch ratio under study was (1:1.5:3) cement, sand and gravel respectively which is used in Iraq. All the raw materials used were locally manufactured.
Concrete slabs (250x250x70) mm dimensions were casted, using Poly-wood molds. Two steel bars were embedded in the central position of each slab at the mid- height (about 35 mm), with a space of 100 mm between each other.
A 16 concrete slabs were prepared (0, 20, 25 and 30) wt. % of fly ash. The specimens were partially immersed in 3.5 wt. % NaCl solution in order to predict the corrosion.
Half-cell potential test technique was used to estimate the corrosion rate which is occurred in the steel bar due to the migration of chloride ions through the concrete, depending on the ASTM C876-08.
The result shows that the potential values of steel in concrete were shifts to the positive direction with increasing the percentage of fly ash, because the reduction of porosity by the addition of fly ash which fill the pores and inhibit the chloride ions to reach to steel.
The results also show that the further increase of fly ash (30%) the possibility of carbonation is increased which result in reduction its alkalinity, thereby permitting corrosion of embedded steel.
Water flow into unsaturated porous media is governed by the Richards’ partial differential equation expressing the mass conservation and Darcy’s laws. The Richards’ equation may be written in three forms,where the dependent variable is pressure head or moisture content, and the constitutive relationships between water content and pressure head allow for conversion of one form into the other. In the present paper, the “moisture-based" form of Richards’ equation is linearized by applying Kirchhoff’s transformation, which
combines the soil water diffusivity and soil water content. Then the similarity method is used to obtain the analytical solution of wetting front position. This exact solution is obtained by means of Lie’s
(2)
Based on collections made during March to September 2012. A totals of 58 species belong to 33 genera were identified from extra north to extra south of Erbil governorate, among them 30 species are registered as a new record to flora of Iraq. Most attention was paid to the most common and abundant lichens that present almost in most locations, which were Collema cristatum, Diploschistes scruposus, Lecanora dispersa, Lecanora murales, Pertusaria flavicunda, Placidium lacinulatum, Thelomma californicum and Verrucaria Maura.
The possibility of using zero-valent iron as permeable reactive barrier in removing lead from a contaminated groundwater was investigated. In the batch tests, the effects of many parameters such as contact time between adsorbate and adsorbent (0-240 min), initial pH of the solution (4-8), sorbent dosage (1-12 g/100 mL), initial metal concentration (50-250 mg/L), and agitation speed
(0-250 rpm) were studied. The results proved that the best values of these parameters achieve the maximum removal efficiency of Pb+2 (=97%) were 2 hr, 5, 5 g/100 mL, 50 mg/L and 200 rpm respectively. The sorption data of Pb+2 ions on the zero-valent iron have been performed well by Langmuir isotherm model in compared with Freundlich model under the studied
(5)
The present study aimed to investigated Giardia duodenalis in cattle in some different areas of Wasit province by using molecular study and verification of the genotype of Giardia duodenalis. Collected one hundred fecal samples from cattle, the result showed that the rate of infection was 83% (100) . DNA was extracted from the 100 positive samples from the cattle then amplified using the special tris-phosphatesomerase gene for genotyping A and B. The result of type A infection was (69%) and (45%) of the genotype B. The purpose of this study was to investigate the genotypes of cattle in Wasit province and compare them with previous sources at the NCBI data bank.
The aim of this study is to propose mathematical expressions for estimation of the flexural strength of plain concrete members from ultrasonic pulse velocity (UPV) measurements. More than two hundred pieces of precast concrete kerb units were subjected to a scheduled test program. The tests were divided into two categories; non-destructive ultrasonic and bending or rupture tests. For each precast unit, direct and indirect (surface) ultrasonic pulses were subjected to the concrete media to measure their travel velocities. The results of the tests were monitored in two graphs so that two mathematical relationships can be drawn. Direct pulse velocity versus the flexural strength was given in the first relationship while the second equation des
... Show MoreIn this study, sawdust as a cheap method and abundant raw material was utilized to produce active carbon (SDAC). Physiochemical activation was utilized where potassium hydroxide used as a chemical activating agent and carbon dioxide was used as a physical activating agent. Taguchi method of experimental design was used to find the optimum conditions of SDAC production. The produced SDAC was characterized using SEM to investigate surface morphology and BET to estimate the specific surface area. SDAC was used in aqueous lead ions adsorption. Adsorption process was modeled statistically and represented by an empirical model. The highest specific surface area of SDAC was 688.3 m2/gm. Langmuir and Freundlich isotherms were used to
... Show MoreThe cuneiform texts considered one of the most important resources which play an important role help us to know how was the economic , politic and religious manner and every thing have relation of the history of Mesopotamia which contain many of information that enrich our knowldgement every side of Mesopotamia civilization since using writing as away to register the science and human knowldgement . The city of Sippar (Abu –Habba ) was one of most important city of ancient Mesopotamia which mentioned as one of first five Mesopotamian cities found before floating and it exposed through excavating rich one of them tablet which some of it dated to old Babylon period . The king Ammi-Saduqa has a big share of tablet we study number of thi
... Show MoreThis study is designed to isolate and molecular identification of C. gattii, C. gattii is pathogenic yeast and effect immunocomposed and immunocompetent, Methods: collect 50 samples from eucalyptus leaves. The collection time was extended from November 2021 to February 2022 and then culture at SDA, Cryptococcus Differential Agar esculin agar and Eucalyptus leaves agar, Brain heart infusion agar with methyldopa and Brain heart infusion agar with methyldopa media, biochemical test including urease test, and then confirm identification by molecular identification by PCR technique sequencing and genetic analysis. The results showed that 4 swaps taken from eucalyptus leaves included cryptococcus neoformans. This study indicated that the virulenc
... Show MoreThe study aimed to identify how to raise grateful children from an Islamic educational perspective. For that objective to be achieved, the researcher used both of deductive and descriptive approaches using the method of documentary research. The study's results show that children are the real wealth of the community and the foundation of cultural building; therefore, paying attention their raising is a responsibility that must be shared by everyone; gratitude is part parcel of the Islamic doctrine, which is one of the greatest virtues; the virtue of gratitude is the attitude of the believers which in turn strengthens the bonds and expands the network of positive social relationships; It is also considered a cultural significance
... Show MoreABSTRACT:. The Lower Cretaceous Zubair formation is comprised of sandstones intercalated with shale sequences. The main challenges that were encountered while drilling into this formation included severe wellbore instability-related issues across the weaker formations overlaying the reservoir section (pay zone). These issues have a significant impact on well costs and timeline. In this paper, a comprehensive geomechanical study was carried out to understand the causes of the wellbore failure and to improve drilling design and drilling performance on further development wells in the field. Failure criteria known as Mogi-Coulomb was used to determine an operating mud weight window required for safe drilling. The accuracy of the geomechanical
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