The high cost of chemical analysis of water has necessitated various researches into finding alternative method of determining portable water quality. This paper is aimed at modelling the turbidity value as a water quality parameter. Mathematical models for turbidity removal were developed based on the relationships between water turbidity and other water criteria. Results showed that the turbidity of water is the cumulative effect of the individual parameters/factors affecting the system. A model equation for the evaluation and prediction of a clarifier’s performance was developed:

Model: T = T₀(-1.36729 + 0.037101∙10^λpH + 0.048928t + 0.00741387∙alk)

The developed model will aid the predictiv

The most influential theory of ‘Politeness’ was formulated in 1978 and revised in 1987 by Brown and Levinson. ‘Politeness’, which represents the interlocutors’ desire to be pleasant to each other through a positive manner of addressing, was claimed to be a universal phenomenon. The gist of the theory is the intention to mitigate ‘Face’ threats carried by certain ‘Face’ threatening acts towards others.

            ‘Politeness Theory’ is based on the concept that interlocutors have ‘Face’ (i.e., self and public – image) which they consciously project, try to protect and to preserve. The theory holds that various politeness strategies are used to prot

Abstract

    Binary polymer blend was prepared by mechanical mixing method of unsaturated polyester resin with Nitrile Butadiene Rubber (NBR) with different weight ratios (0, 5, 10 and 15) % of (NBR). Tensile characteristics and wear rates of these blends were studied for all mixing ratios. The microstructure of fracture surfaces of the prepared samples were investigated by optical microscope. The results were showed that strain rates of the resin material increase after blending it with rubber while the ultimate tensile strength and Young’s modulus values of it will decrease. It is also noticed that the wear rate of resin decreases with increasing of (NBR) content.

Keywords:<

The research aimed mainly to discover the effectiveness of the (PEOE) model in teaching science to develop the skills of generating and evaluating information and the emotional side of the scientific sense of the intermediate first grade students. An experimental approach with a quasi-experimental design called pre-test and post-test control design was used. The research sample consisted of (60) students, who were selected in a random cluster method, (30) students in the experimental group studied the unit "The Nature of Material" using the (PEOE) model, and (30) students in the control group studied according to the prevailing method of teaching. The research materials and tools were represented in: a teacher's guide for teaching the un

Samples of the green algae were collected from water of Shatt al-Arab in Garmat Ali in Basra. After purification, the green algae identified on Enteromorpha sp. The samples were dried and milled, then sulfated polysaccharides were extracted with hot water at 90°C precipitated with absolute ethanol, dialysed and lyophilized. The chemical composition was total sugars 56.4%, protein 1.3% and sulfur 19.7%. Antioxidation activity of sulfated polysaccharides was studied by four method and included estimation of ability of scavenging hydroxylated radicals, the results showed an increased in ability with increasing concentrations. Ability of scavenging and was 59.86% at the concentration of 2.5 mg/ ml, but BHT was 81.36%. Ability of scavenging

Abstract

In this paper presents two dimensional turbulent flow of different nanofluids and ribs configuration in a circular tube have been numerically investigation using FLUENT 6.3.26. Two samples of CuO and, ZnO nanoparticles with 2% v/v concentration and 40 nm as nanoparticle diameter combined with trapezoidalribs with aspect ratio of p/d=5.72 in a constant tube surface heat flux were conducted for simulation. The results showed that heat flow as Nusselt number for all cases raises with Reynolds number and volume fraction of nanofluid, likewise the results also reveal that ZnO with volume fractions of 2% in trapezoidal ribs offered highest Nusselt number at Reynolds number of Re= 30000.

Key

The aim of the research is to indicate the degree of arrangement of the tax branches discussed and the level of efficiency of their performance according to the dimensions approved in the tax diagnostic tool (TADAT). The checklist has been approved as a main tool in collecting data and information from the tax branches of the General Authority for Taxes and the number (8) branches represented by (Karrada , Karakh Center, Al-Rusafa, New Baghdad, Al-Dora, Karakh Al-Tafim, Al-Kadhimiya, Al-Bayaa),  The statistical program (spss) was used to calculate the weighted arithmetic media, and we reached the research to a number of conclusions, the most important of which were: - Each of the subsections (Karkh Al-Ahram and Karrada) achieved an