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.
The research aims to provide an integrated knowledge framework for the two basic research topics of (marketing deception, organizational reputation), their main dimensions, and framing the knowledge within them in a serious attempt to provide appropriate answers to the questions of the research problem by diagnosing the nature of the relationship between the components of marketing deception to identify the elements and how to activate it via reputable organizational components. The research was based on the analytical survey method. The research sample targeted (364) pharmacies within the capital Baghdad exclusively, the main tool of the research was the questionnaire, as well as the design of models prepared fo
... Show MoreAn aqueous chemical reaction has been used to prepare antifungal ZnS: Mn nanostructures, from manganese chloride, zinc acetate and thioacetamide in aqueous solution. The nanoparticle size has been controlled using thioglycolic acid as a capping factor. The major feature of the ZnS:Mn nanoparticles of average diameter ~ 2.73 nm is that possible preparing the sample from sources non-toxic precursors. The manufactured ZnS:Mn nanoparticles were identified and characterized to investigate the structure, morphology, composition of components of the nanoparticles and optical properties using (XRD, SEM, EDS and UV-Vis spectroscopy) techniques respectively. The agar dilution mechanism used to evaluate of the antifungal activity using ZnS:Mn nanopart
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Conventional hardening, sometimes, is not economically viable due to consuming additional costs and energy. This makes applying selective hardening on specific regions an attractive alternative for members subjected to local friction and wear. This work is devoted for applying cold working hardening on discrete values on regions of aluminum 6061-O alloy using nanosecond fiber laser of 100 W average power and pulse duration of 81 ns. An exaggerated plasma pressure resulted from ablation a thin coat layer on the metal surface was built in order to cause cold plastic deformation and increase the surface hardness of the alloy. The power density (Pd) and pulse overlap percentage (OV) were employed as working parameters. Due to the sensit
... Show MoreThe current research focuses on a major problem: the weak role of disclosing corporate information in the application of laws, regulations and instructions related to the application of corporate governance principles weakens the ability to protect the rights of shareholders and investors in companies listed on the Iraqi Stock Exchange and the study aims to study and analyze the role of disclosure and transparency in achieving the necessary protection to ensure the rights of shareholders. The study was applied to a sample of (42) analysis samples representing (84%) of the total questionnaires distributed to investors and shareholders in all listed companies in the Iraqi Stock Exchange. The results confirm the shareholder's right to obtai
... Show MoreThe audit profession today gets an increasing interest by the financial , economic and legal contemporary societies , because of the importance of the technical & neutral auditor’s opinion to the financial reports beneficiaries in order to enable them making their investment decisions , but some of them whom suffered damage or loss when they made that decisions according to the mentioned financial statements which consolidated with auditor’s report , exposed the function to a responsibility and credibility crisis in addition to missing the trust especially at the latest years. They always ask why or what is the reason that cause the auditor didn’t giving us any warning signs about the economic mater for that companies.
The objective of this study is to determination the content of some heavy metals (lead, cadmium, chromium) in colored tattoo stickers. twelve kinds of colored tattoo stikcers were collected from Baghdad markets, it was estimated heavy metals using atomic absorption spectrophotometer (Shimadzu A5000). The results indicated the concentrations of lead in all samples (1.61_1.00 mg / kg) and chromium in the three samples (0.85_0.97 mg / kg) while other samples are free of chromium , and cadmium. These elements are the components of printing inks and dyes in tattoo stickers, and this does not conform to the health and safety conditions for the packaging of food according to the organizations of the health and safety of
... Show MoreIntroduction: This study aimed to assess the color change of human teeth with artificial enamel white spot lesions (WSLs) after sandblasting with bioactive glass, resin infiltration, and microabrasion and to test color stability after pH cycling. Methods: Fifty extracted human mandibular first molars were randomly assigned into five groups: Sound, WSLs (untreated), and WSLs sandblasted with bioactive glass (Sylc), WSLs treated by resin infiltration (ICON), and WSLs treated by microabrasion (Opalustre), respectively. All specimens underwent a pH cycling procedure. The color parameters for each specimen were assessed using an Easyshade dental spectrophotometer at different time stages then the color changes (ΔE) were calculated. Results: The
... Show MoreThe aim of this study was to increasing natural carotenoides production by a locally isolate Rodotorula mucilagenosa M. by determination of the optimal conditions for growth and production of this agents, for encouragest to use it in food application permute artificial pigments which harmfull for consumer health and envieronmental. The optimal condition of carotenoides production from Rhodotorula mucilaginosa M were studied. The results shows the best carbon and nitrogen source were glucose and yeast extract. The carotenoids a mount production was 47430 microgram ̸ litter and 47460 microgram ̸ litter, respectively, and the optimum temperature was 30°C, PH 6, that the carotenoides a mount was 47470 microgram ̸ litter and 47670 microgr
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The research aims to study the effect of the commodity dumping phenomenon that Iraq suffered after 2003 on the consumption pattern of individuals, towards the acquisition of non-essential goods (luxury). To achieve our goal we relied on the questionnaire as a main tool for obtaining information related to the research, and it was distributed on a random sample of consumers in the city of Baghdad with 250 questionnaires. The answers of the research sample were analyzed using the statistical program (SPSS). The percentage weights and the factorial analysis method were used also to arrange the variables that affected on changing consumption patterns. The research reached a set of conclusions:
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