Previously, many empirical models have been used to predict corrosion rates under different CO2 corrosion parameters conditions. Most of these models did not predict the corrosion rate exactly, besides it determined effects of variables by holding some variables constant and changing the values of other variables to obtain the regression model. As a result the experiments will be large and cost too much. In this paper response surface methodology (RSM) was proposed to optimize the experiments and reduce the experimental running. The experiments studied effects of temperature (40 – 60 °C), pH (3-5), acetic acid (HAc) concentration (1000-3000 ppm) and rotation speed (1000-1500 rpm) on CO2 corrosion performance of the regression model calculated by RSM. The experiments were conducted in saturated solution of CO2 with 3.5 % NaCl solution. STATISTICA program version 10 was used for data analysis. In conclusion a quadratic model is proposed to predict the effect of mentioned variables in CO2 environment.
Abstract:The optimum design of the magnetic deflector with the lowest values of the radial and spiral distortion aberration coefficients was computed. The optimized calculations were made using three models, Glaser bell-shaped, Grivet-lenz and exponential models. By using the optimum axial field distribution, the pole pieces shape which gave rise to those field distributions was found by using the reconstruction method. The calculations show that the results of the three models coincide at the lower values of the excitation parameter. In general the Glaser- bell shaped model gives the optimum results at the whole range of the excitation parameter under investigation.The negative values of the spiral distortion aberration coefficient appears
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Radon concentrations are measured for water samples collected from twenty wells which were drilled in Hashimiya area in addition to twelve samples of surface water using Alpha Gaurd. 140 samples, 7 for each well, were collected represent wet season in continuous pumping and 20 samples, one for each well, were collected represent dry season. Concentration of radon in groundwater is many times of its concentration in surface water. The minimum concentration in groundwater is about (7) Bq/L and (5) Bq/L while the maximum concentration is about (31) Bq/L and (19) Bq/L in wet season and dry season respectively. The range of radon concentrations in river water is between (1.06) Bq/L and (1.21) Bq/L. This study has indicated that there is a flo
... Show MoreA (b,t)-blocking set B in PG(2,q) is set of b points such that every line of PG(2,q) intersects B in at least t points and there is a line intersecting B in exactly t points. In this paper we construct a minimal (b,t)-blocking sets, t = 1,2,3,4,5 in PG(2,5) by using conics to obtain complete arcs and projective codes related with them.
raisin on mice in comparison with negative (phosphate buffer saline (PBS) and positive Mitomycin-C (MMC) controls. Moreover, the effect on fertility hormones (follicles stimulation hormone/FSH, lutenising hormone/LH) was also measured. The effect of the extracted samples were measured by employing cytogenetic analysis which included (the mitotic index (MI), chromosomal aberrations (CAs) and micronucleus (MN)) parameters. Results showed that significant increase in MI and significant reduction in both CAs and MN percentage were seen after treatment with both alcoholic and water extracts of the two raisins and alcoholic extracts was more effective than water extracts. On the other hand both the gold and black raisin enhanced the levels of the
... Show MoreIn this study, composite materials consisting of Activated Carbon (AC) and Zeolite were prepared for application in the removal of methylene blue and lead from an aqueous solution. The optimum synthesis method involves the use of metakaolinization and zeolitization, in the presence of activated carbon from kaolin, to form Zeolite. First, Kaolin was thermally activated into amorphous kaolin (metakaolinization); then the resultant metakaolin was attacked by alkaline, transforming it into crystalline zeolite (zeolitization). Using nitrogen adsorption and SEM techniques, the examination and characterization of composite materials confirmed the presence of a homogenous distribution of Zeolite throughout the activated carbon.
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Samples from tap water were chosen to be examined as one of the possible modes of G. lamblia and other parasites transmission. 144 domestic filter units were randomly distributed to houses in Baghdad in Al-Sadr City and surrounding regions then the suspended materials were examined microscopically by direct wet mount after centrifugal sedimentation method, and after staining with modified Ziehl-Neelsen (acid fast) stain. The results showed that 5/144 (3.47%) samples contained G. lamblia cysts, 3/144 (2.08%) contained E. histolytica/E. dispar cyst, while each of Cryptosporidium spp. and Cyclospora cayetanensis oocysts were observed in two samples (1.38%); also free living amoeba, ciliates and flagellates were detected in all samples. This
... Show MoreThe characterization and design of this study of new liquid crystals with a V shape compounds containing thiazolidine-2,4-dione and 1,3-phenylene as a core unite with mesophase properties were reported. Preparation and characterization of chloroacetic acid, water, and thiourea to produce thiazolidine-2,4-dione [I] in the presence of strong hydrochloric acid. The 4-hydreoxybenzaldehyde and n-alkyl bromide were reacted with potassium hydroxide to create the n-alkoxy benzaldehyde., then the compound [I] reacted with [II]n in presence of piperidine to produce compounds [III]n. Also, converted resorcinol to a corresponding compound [IV] by refluxing pyridine and DMF with two moles of chlora
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This study was aimed to assess the efficiency of N.oleander to remove heavy metals such as Copper (Cu) from wastewater. A toxicity test was conducted outdoor for 65-day to estimate the ability of N.oleander to tolerate Cu in synthetic wastewater. Based on a previous range-finding test, five concentrations were used in this test (0, 50, 100, 300, 510 mg/l). The results showed that maximum values of removal efficiency was found 99.9% on day-49 for the treatment 50 mg/l. Minimum removal efficiency was 94% day-65 for the treatment of 510 mg/l. Water concentration was within the permissible limits of river conservation and were 0.164 at day-35 for the 50 mg/l treatment, decreased thereafter until the end of the observation, and 0.12 at d
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Some new 2,5-disubsituted-1,3,4-oxadiazole derivatives with azo group were synthesized by known reactions sequence . The structure of the synthesized compounds were confirmed by physical and spectral means .
The characterization and design of this study of new liquid crystals with a V shape compounds containing thiazolidine-2,4-dione and 1,3-phenylene as a core unite with mesophase properties were reported. Preparation and characterization of chloroacetic acid, water, and thiourea to produce thiazolidine-2,4-dione [I] in the presence of strong hydrochloric acid. The 4-hydreoxybenzaldehyde and n-alkyl bromide were reacted with potassium hydroxide to create the n-alkoxy benzaldehyde., then the compound [I] reacted with [II]n in presence of piperidine to produce compounds [III]n. Also, converted resorcinol to a corresponding compound [IV] by refl
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