The present work reports the performance of three types of polyethersulfone (PES) membrane in the removal of highly polluting and toxic lead Pb2+ and cadmium Cd2+ ions from a single salt. This study investigated the effect of operating variables, including pH, types of PES membrane, and feed concentration, on the separation process. The transport parameters and mass transfer coefficient (k) of the membranes were estimated using the combined film theory-solution-diffusion (CFSD), combined film theory-Spiegler-Kedem (CFSK), and combined film theory-finely-porous (CFFP) membrane transport models. Various parameters were used to estimate the enrichment factors, concentration polarization modulus, and Péclet number. The pH values significantly affected the permeation flux of the Pb2+ solution but only had a slight effect on the Cd2+ solution. However, Cd2+ rejection was highly improved by increasing the pH value. The rejection of the PES membranes increased greatly as the heavy metal concentration rose, while the heavy metal concentration moderately affected the permeation flux. The maximum rejection of Pb2+ in a single-salt solution was 99%, 97.5%, and 98% for a feed solution containing 10 mg Pb/L at pH 6, 6.2, and 5.7, for PES1, PES2, and PES3, respectively. The maximum rejection of Cd2+ in single-salt solutions was 78%, 50.2%, and 44% for a feed solution containing 10 mg Cd/L at pH 6.5, 6.2, and 6.5, for PES1, PES2, and PES3, respectively. The analysis of the experimental data using the CFSD, CFSK, and CFFP models showed a good agreement between the theoretical and experimental results. The effective membrane thickness and active skin layer thickness were evaluated using the CFFP model, indicating that the Péclet number is important for determining the mechanism of separation by diffusion.
الغرض من البحث دراسة تأثير ادارة المعرفة (استراتيجية الشخصنة والترميز) في تحقيق التفوق الاستراتيجي في بيئة المصارف الاهلية العراقية ، وتم اعتماد منهج البحث الوصفي والتحليلي ، لذا اعتمد الباحث الفلسفة الوضعية وفق المنهج الاستنباطي لغرض اشتقاق فرضية البحث الاولى من الجانب النظري وتوصل البحث الى مجموعة من النتائج اهمها ان استراتيجية الشخصنة حققت تقدماً كبيراً في قدرتها على التأثير في التفوق الاستراتيجي بوصف
... Show MoreThe investigation of determining solutions for the Diophantine equation over the Gaussian integer ring for the specific case of is discussed. The discussion includes various preliminary results later used to build the resolvent theory of the Diophantine equation studied. Our findings show the existence of infinitely many solutions. Since the analytical method used here is based on simple algebraic properties, it can be easily generalized to study the behavior and the conditions for the existence of solutions to other Diophantine equations, allowing a deeper understanding, even when no general solution is known.
Abstract
The current research aims to find out the role of administrative leadership in the implementation of public policies and their effectiveness and their ability to do so, As well as analysis and testing of influence and correlations between research variables, The researcher has the descriptive and analytical approach, And several tools used to gather information consisted of personal interviews and field visits, While distributed questionnaire tool that consists of (35) items on a sample consisting of (147) individuals formed of staff of the Baghdad Provincial Council.
The research was based on a set of assum
... Show MoreThe theatrical field has witnessed a huge development that included the semantic and formal sides, considering that the theatrical experience has gone through a long period of description and the dominance of literature and linguistics, thus the theatrical experience has been open to many workings and uses of high quality in forming and composing the visual system. The semiotics had a role in presenting transformed sign forms and features generated in the theatrical space. Thus (costumes, décor, makeup, lighting, and actor) are considered elements with sign forms and attributes that together constitute integrated semiotic unit that include all the layouts in the scenographic space. The two researchers determined on semiotics due to its
... Show MoreThe primary objective of this study is to examine the effects of a do-it-yourself (DIY) technique on the reading comprehension performance of fifth-grade students in preparatory schools. In order to accomplish the objective of this research, it is posited that a null hypothesis can be established, suggesting that there are no statistically significant disparities between the average scores of the experimental group, which is instructed using a do-it-yourself (DIY) strategy, and the control groups, which are instructed using a prescribed method, in terms of their reading comprehension attainment. Developing a pre- and post-achievement test. Both groups have been equalized in terms of characteristics such as parental educational leve
... Show MoreObjectives: The study aims at identifying the nurses’ knowledge about peritoneal dialysis complications, to
construct an education program for nurses in peritoneal dialysis units, to determine the effectiveness of the
education program upon the nurses' knowledge about complications of peritoneal dialysis, and to identify the
relationship between the nurses’ knowledge and their demographic characteristics of level of education and
years of experience.
Methodology: A quasi-experimentai study was carried out at the peritoneal dialysis units of Baghdad teaching
hospitals, from April 2004 to April 2006.
٨ purposive sample of (50) nurse was selected from Baghdad teaching hospitals. These nurses working at the
perit
The paper aims to measure and analysis the impact Public Spending on Iraq economy (Kaldor Variables).
(variables of the magic square Kaldor) and them in after 2003.
The paper adopted econometric Methods to test the stationarity of the Variables under consideration. For the period (2005-2016) by using multiple regression and estimation the Impulse response function (IRF), by adopting Eviews 10 program.
The results of Impulse response function for the following five-years after the period under consideration reflexes that public expenditure (PEX) was fluctuating between positive and negative in all the variables of the research and this shows the fragility of the performance of fiscal policy in Iraq.
T
... Show MoreIn this research, we study the changing structural properties of ZnO with changing annealing temp., in the range (473-773)K prepared by chemical bath deposition method at temp. (353)K, where deposited on glasses substrates at thickness (500±25)nm, the investigation of (XRD) indicates that the (ZnO) films are polycrystalline type of Hexagonal.
The results of the measuring of each sample from grain size, microstrain, dislocation density, integral breadth, shape factor and texture coefficient, show that annealing process leads to increase the grain size (26.74-57.96)nm, and decrease microstrain (0.130-0.01478), dislocation density (1.398-0.297)*1015
... Show MoreThe high carbon dioxide emission levels due to the increased consumption of fossil fuels has led to various environmental problems. Efficient strategies for the capture and storage of greenhouse gases, such as carbon dioxide are crucial in reducing their concentrations in the environment. Considering this, herein, three novel heteroatom-doped porous-organic polymers (POPs) containing phosphate units were synthesized in high yields from the coupling reactions of phosphate esters and 1,4-diaminobenzene (three mole equivalents) in boiling ethanol using a simple, efficient, and general procedure. The structures and physicochemical properties of the synthesized POPs were established using various techniques. Field emission scanning elect
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