The present work aimed to study the efficiency of nanofiltration (NF) and reverse osmosis (RO) process for water recovery from electroplating wastewater and study the factors affecting the performance of two membrane processes. Nanofiltration and reverse osmosis membranes are made from polyamide as spiral wound module. The inorganic materials ZnCl2, CuCl2.2H2O, NiCl2.6H2O and CrCl3.6H2O were used as feed solutions. The operating parameters studied were: operating time, feed concentrations for heavy metal ions, operating pressure, feed flow rate, feed temperature and feed pH. The experimental results showed, the permeate concentration increased and water flux decreased with increase in time from 0 to 70 min. The permeate concentrations increased and flux decreased with increase in feed concentrations from 10 to 300 mg/l. Raising of pressure from 1 to 4 bar, permeate concentration decreased for RO, for NF decreased and then increased at high pressure and increase the flux. The rises of flow rate from 20 to 50 l/h decreased permeate concentration and the flux increase. The rises of temperature from 26 to 40 °C, increased permeate concentration and increased the flux. The rise in pH from 4 to 7, decreased the flux as the pH goes from acidic side towards alkaline. The polyamide nanofiltration membrane had allowed permeation of chromium and copper ions to lower than permissible limits. Nanofiltration membrane had allowed permeation of nickel and zinc ions at low concentration of these ions. The polyamide RO membrane gave a high efficiency for removal of chromium, copper, nickel and zinc and it had allowed permeation of these ions to the lower than permissible limits. The rejection at first three minutes when the feed concentration approximately was constant for chromium in NF and RO, was 99.7% and 99.93%, for copper was 98.43% and 99.33%, for zinc was 97.96% and 99.49%, and for nickel was 97.18% and 99.49% respectively. The maximum recovery for chromium in NF and RO was 71.75% and 48.5%, for copper was 75.62% and 50.68%, for zinc was 80.87% and 54.56%, for nickel was 60.06% and 46.18% respectively. For a mixture of synthetic electroplating wastewater, nanofiltration and reverse osmosis membranes have a high rejection percentage for heavy metal ions. It was obtained pure water and concentrations of less than allowable limits for heavy metals in the case of the mixture.
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The 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
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Objective: the aim of the study is to assess the knowledge and practices for nurses that working in
words of Ibn Al-kuff hospital for spinal cord injuries.
Methodology: descriptive study from the period of (1st of July to the 30th August 2005) about the
knowledge and practical management when autonomic dysreflexia syndrome affects those patients
whom sleeping in the words of this hospital and its relationship with some variables.
The sample of the study consists of (100) nurses male and females are selected purposively. a
questionnaire check list was designed for study purpose and applied by (test - retest) to improve the
reliability, the validity of the assessment was determined through a panel of experts.
The da
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This study investigated the bioethanol production from green algae Chlorella vulgaris depending on its carbohydrate-enriched biomass. Four different phosphorous concentrations were employed to stimulate bioethanol production from Chlorella vulgaris. The impact of various phosphorous values on Chlorella vulgaris growth rate as well as primary product (carbohydrate) were evaluated. High performance liquid chromatography was utilized in this work. The stationary phase was identified as day 14, 12, 10 and 6 in treatments 6, 4, 2 and g/L, respectively. The findings suggest that the treatment without phosphorous addition had the highest record of carbohydrate content (22.64% dry weight) as well as the highest bioethanol yield (20.66% dry weight).
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In this paper, a new third kind Chebyshev wavelets operational matrix of derivative is presented, then the operational matrix of derivative is applied for solving optimal control problems using, third kind Chebyshev wavelets expansions. The proposed method consists of reducing the linear system of optimal control problem into a system of algebraic equations, by expanding the state variables, as a series in terms of third kind Chebyshev wavelets with unknown coefficients. Example to illustrate the effectiveness of the method has been presented.
Nearly a century and a half has passed since Sarah Orne Jewett published her much anthologized short story “A White Heron” (1886), but commentators on the tale missed one of the most important points in the text. It is the story’s similarity to the traditional Euro-centric fairy tale of “Little Red Riding Hood”. As an author, writing at the end of the ninetieth century, a time that witnessed the demise of the Romantic movement in America and the beginning of the age of Realism, Jewett did not romanticize her characters, despite the idyllic landscape in which “A White Heron” is set. Her story can be analyzed as a text that aims at disseminating ecological awareness among her young readers. This study focuses on Jewett
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The objective of the current research is to find an optimum design of hybrid laminated moderate thick composite plates with static constraint. The stacking sequence and ply angle is required for optimization to achieve minimum deflection for hybrid laminated composite plates consist of glass and carbon long fibers reinforcements that impeded in epoxy matrix with known plates dimension and loading. The analysis of plate is by adopting the first-order shear deformation theory and using Navier's solution with Genetic Algorithm to approach the current objective. A program written with MATLAB to find best stacking sequence and ply angles that give minimum deflection, and the results comparing with ANSYS.
Background: To assess the alveolar bone crest level (ABCL) by Cone Beam Computed To-mography (CBCT) and to investigate several variables as predictors for the height of the alveolar bone in adolescents. Materials and methods: Age, sex, and ethnic groups were rec-orded for each patient. CBCT images were used to obtain measurements of the interproximal alveolar bone level from the cementoenamel junction (CEJ) to the alveolar crest. The highest measurement in each sextant was recorded along with any presence of a vertical bone defect or calculus. Results: Total of 720 measurements were recorded for 120 subjects. No vertical bony defects or calculus were observed radiographically. Statistically significant (P< 0.05) differences were observed be
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