This research was aimed to study the efficiency of microfiltration membranes for the treatment of oily wastewater and the factors affecting the performance of the microfiltration membranes experimental work were includes operating the microfiltration process using polypropylene membrane (1 micron) and ceramic membrane (0.5 micron) constructed as candle; two methods of operation were examined: dead end and cross flow. The oil emulsion was prepared using two types of oils: vegetable oil and motor oil (classic oil 20W-50). The operating parameters studied are: feed oil concentration 50 – 800 mg/l, feed flow rate 10 – 40 l/h, and temperature 30 – 50 oC, for dead end and cross flow microfiltration.
It was found that water flux decreases with increasing operating time and feed oil concentration and increases with increasing operating temperature, feed flow rate and pore size of membrane. Also, it was found that rejection percentage of oil increases with increasing flow rate and rejection percentage decreases with increasing time, feed oil concentration, feed temperature and pore size of membrane for dead end and cross flow microfiltration. In cross flow microfiltration, reject concentration (concentrate) increases with increasing flow rate, feed concentration, time and feed temperature. The dead end filter has more flux compared to cross flow filter, while, in cross flow the oil rejection percentage is best than dead end. Flux for vegetable oil is more than motor oil but rejection percentage for vegetable oil is less than that for motor oil. The highest recovery ratio was found is 44.8% for cross flow process with recirculation of concentrating stream to feed vessel. The highest rejection percentage of oil was found is 98 % and 97.8 % for cross flow and dead ends respectively.
The effect of the initial pressure upon the laminar flame speed, for a methane-air mixtures, has been detected paractically, for a wide range of equivalence ratio. In this work, a measurement system is designed in order to measure the laminar flame speed using a constant volume method with a thermocouples technique. The laminar burning velocity is measured, by using the density ratio method. The comparison of the present work results and the previous ones show good agreement between them. This indicates that the measurements and the calculations employed in the present work are successful and precise
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Background: Surface treatment of machined dental zirconia for enhancement of the adhesion to resin cement, using Er,Cr:YSGG Laser. Materials and Methods: Total number of 42 zirconia disc specimens (9 mm diameter, and 2 mm height) was sintered according to the manufacturer instruction. They are divided into six groups, each group of seven samples. Laser groups (Experiment parameters) were depend on laser total irradiation time, pulse duration, and power. Group (A): 20 sec., 60 µs pulse duration. Group (B): 30 sec., 60 µs pulse duration. Group (C): 40 sec., 60 µs pulse duration. Group (D): 20 sec., 700 µs pulse duration. Group (E): 30 sec., 700 µs pulse duration, with different powers used (1, 1
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Find interested in the harmonization of variables and determinants of supply chain planning needs of the material, leading to the results start effective supply chain management, and end up quickly modify the sizes to suit the demand and turnover in the market. As well as identifying relationships between variables, and type of relationship used by the company with the processors and their feasibility, and indicate the level of interest and willingness to redesign the supply chain Company for Electrical Industries and build an integrated model for supply chain with the MRP system can be applied in the company.
Research depend on quantitative and descriptive method, It
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In this study, we design narrow band pass filter for window (3_5) ?m dependent on the needle optimization method , and a comparison with global designs published -Also, the effect of change parameter design on the optical performance of filter was studded and being able to overcome the difficulties of the design.In this study, the adoption of homogeneous optical properties materials as thin film depositing on a substrate of germanium at wavelength design (? = 4 ?m). For design this kind of filters we used advanced computer program (Matlab )to build a model design dependent both matrix characteristic and Needle technique. In this paper we refer to the type of Mert function , which is used for correct optical performance acces
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The Russian foreign policy of the post-cold-war era faced dilemmas in the light of the international and regional realities of the disintegration of the Soviet Union and the formation of a new unipolar international order led by the United States of America. Thus, Russian foreign policy-making was divided over the nature of the foreign policy to be followed. The achievement of the Russian goals, especially as the objectives of Russian foreign policy have been set within the framework of trying to regain the status and leading role, as well as the establishment of some fundamental changes to be consistent with the new international situation of the post-one The Russian Federation has adopted in the sphere of its foreign policy to the vari
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In this work, we first construct Hermite wavelets on the interval [0,1) with it’s product, Operational matrix of integration 2^k M×2^k M is derived, and used it for solving nonlinear Variational problems with reduced it to a system of algebric equations and aid of direct method. Finally, some examples are given to illustrate the efficiency and performance of presented method.
This research aims to identify the cognitive distortion of kindergarten children and its relationship to their parenting reinforcement. The researcher used the descriptive approach, being the closest to reaching the study objectives, To measure the relationship between the research variables, the researcher prepared two questionnaire tools for this purpose, the first for measuring "cognitive distortion", And the second is to measure "parental reinforcement", and each tool consisted of (20) items.
After ensuring the validity and reliability of the two research tools and their suitabi
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Receipt date: 12/28/2020 accepted date: 20/1/2021 Publication date: 12/31/2021
This work is licensed under a Creative Commons Attribution 4.0 International License.
Russia has emerged as a rising and influential power in the international arena, especially with Vladimir Putin's assumption of power and his desire for the rise of Russia and the end of the "unipolarism" represented by the hegemony of the United States of
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