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,

Hydrogen sulfide (H₂S) gas sensor based on cobalt–manganese spinel oxide MnCo₂O₄ thin films that were prepared by chemical precipitation and green synthesis methods. Structural, morphological, and compositional characterizations of MnCo₂O₄ thin films were performed using XRD, FE-SEM, EDS, and AFM. It was found through XRD patterns that MnCo₂O₄ was formed in a cubic spinel structure for both methods; however, the chemically precipitated thin films possessed better crystallinity and larger crystallite sizes, whereas the green-synthesized films exhibited slightly lower crystallinities and smaller sizes, as evidenced by the broader peaks observed. In addition, FE-SEM and AFM images revealed that the MnCo₂O₄ films prepared by

    In light of this, attention should be paid to tax reform as part of a comprehensive economic reform program. Therefore, the research started from the problem of the weak efficiency of the tax reform process in the General Authority for Taxation, as well as the need to know the addition of new taxes or increase taxes.The research aims study the relative importance of each disabled person, whether organizational, human, financial, legislative or technical. The research led to a number of conclusions, the most important of which were that the financial obstacles occupy the highest importance of the other obstacles and for the success of the tax reform, the material resources must be provided in order to provide the n

Abstract

          Binary logistic regression model used in data classification and it is the strongest most flexible tool in study cases variable response binary when compared to linear regression. In this research, some classic methods were used to estimate parameters binary logistic regression model, included the maximum likelihood method, minimum chi-square method, weighted least squares, with bayes estimation , to choose the best method of estimation by default values to estimate parameters according two different models of general linear regression models ,and different s

This work presents a five-period chaotic system called the Duffing system, in which the effect of changing the initial conditions and system parameters d, g and w, on the behavior of the chaotic system, is studied. This work provides a complete analysis of system properties such as time series, attractors, and Fast Fourier Transformation Spectrum (FFT). The system shows periodic behavior when the initial conditions xi and yi equal 0.8 and 0, respectively, then the system becomes quasi-chaotic when the initial conditions xi and yi equal 0 and 0, and when the system parameters d, g and w equal 0.02, 8 and 0.09. Finally, the system exhibits hyperchaotic behavior at the first two conditions, 0 and 0, and the bandwidth of the chaotic

The electrospun nanofibers membranes (ENMs) have gained great attention due to their superior performance. However, the low mechanical strength of ENMs, such as the rigidity and low strength, limits their applications in many aspects which need adequate strength, such as water filtration. This work investigates the impact of electrospinning parameters on the properties of ENMs fabricated from polyacrylonitrile (PAN) solved in N, N-Dimethylformamide (DMF). The studied electrospinning parameters were polymer concentration, solution flow rate, collector rotating speed, and the distance between the needle and collector. The fabricated ENMs were characterized using scanning electron microscopy (SEM) to understand the surface morphology and es

The present study aimed to explain the dose-dependent possible deleterious effects of 30 day administration of Tramadol on some hematological and biochemical parameters of laboratory male rats (Rattus norvegicus), the study consisted of eighteen adult male rats randomly divided into three equal groups (each of six). Group 1 (control) were treated by intraperitoneal injection of normal saline solution (0.2 ml), group two (low dose) was treated by intraperitonealy (i.p) injection of Tramadol at a dose of 50 mg/kg/day, group three (high dose) was treated by intraperitonealy injection of Tramadol at a dose of 100 mg/kg/day for 30 days. At the end of experimental period, rats were sacrificed. Blood were collected by cardiac puncture to inv

In this work, two groups of nanocomposite material, was prepared from unsaturated polyester resin (UPE), they were prepared by hand lay-up method. The first group was consisting of (UPE) reinforced with individually (ZrO2) nanoparticles with particle size (47.23nm). The second group consists of (UPE) reinforced with hybrid nanoparticles consisting of zirconium oxide and yttrium oxide (70% ZrO2 + 30% Y2O3) with particles size (83.98nm). This study includes the effect of selected volume fraction (0.5%, 1%, 1.5%, 2%, 2.5%, 3%) for both reinforcement nano materials. Experimental investigation was carried out by analyzing the thermo-physical properties like thermal conductivity, thermal diffusivity and specific heat for the polymeric composit

There is a theoretical controversy in the books of Usul al-Fiqh, in the past and the present, about whether the ruling should be attached to its reason (al-Hikmah), or its apparent and stable cause (al-Illah). Looking at the practical cases of the jurists, we found them sometimes attaching rulings to its reason, and sometimes to its cause, so there is a need to know the factors that affect their choices. By extrapolation, the researcher reached at nine factors that affect referring the ruling to its cause or to its reason in jurisprudential cases.

The research aims at recognition of The rate of performing tasks done by the scientific committees in the scientific departments in the University of Baghdad, within the evaluative perspective of the departments’ Heads. To find any statistically significant differences in the responses of the research sample to the rates performance of the scientific committees in scientific departments in the University of Baghdad, within the evaluative perspective of the departments’ Heads, according to the two variables of the social gender; male and females, and field of specialization of Scientific and Humanities. The research sample consisted if (107) heads of the scientific department in the University of Baghdad. The researchers designed a