In the present study, advanced oxidation treatment, the TiO2 /UV/H2O2 process was applied to decolorisation of the reactive yellow dyes in aqueous solution. The UV radiation was carried out with a 6 W low-pressure mercury lamp. The rate of color removal was studied by measuring the absorbency at a characteristic wavelength. The effects of H2O2 dosage, dye initial concentration and pH on decolorisation kinetics in the batch photoreactor were investigated. The highest decolorisation rates were observed (98.8) at pH range between 3 and 7. The optimal levels of H2O2 needed for the process were examined. It appears that high levels of H2O2 could reduce decolorisation by scavenging the *OH. The color degradation rate decreases as the dye concentration increases. The rate coefficient (k=0.0319 min-1) of degradation, follows the pseudo-first-order kinetics.
Electrocoagulation is an electrochemical method for treatment of different types of wastewater whereby sacrificial anodes corrode to release active coagulant (usually aluminium or iron cations) into solution, while simultaneous evolution of hydrogen at the cathode allows for pollutant removal by flotation or settling. The Taguchi method was applied as an experimental design and to determine the best conditions for chromium (VI) removal from wastewater. Various parameters in a batch stirred tank by iron metal electrodes: pH, initial chromium concentration, current density, distance between electrodes and KCl concentration were investigated, and the results have been analyzed using signal-to-noise (S/N) ratio. It was found that the r
... Show MoreThe High Power Amplifiers (HPAs), which are used in wireless communication, are distinctly characterized by nonlinear properties. The linearity of the HPA can be accomplished by retreating an HPA to put it in a linear region on account of power performance loss. Meanwhile the Orthogonal Frequency Division Multiplex signal is very rough. Therefore, it will be required a large undo to the linear action area that leads to a vital loss in power efficiency. Thereby, back-off is not a positive solution. A Simplicial Canonical Piecewise-Linear (SCPWL) model based digital predistorters are widely employed to compensating the nonlinear distortion that introduced by a HPA component in OFDM technology. In this paper, the genetic al
... Show MoreThe distribution of chilled water flow rate in terminal unit is an important factor used to evaluate the performance of central air conditioning unit. A prototype of A/C unit has been made, which contains three terminal units with a complete set of accessories (3-way valve, 2-way valve, and sensors) to study the effect of the main parameters, such as total water flow rate and chilled water supply temperature with variable valve opening. In this work, 40 tests were carried out. These tests were in two groups, 20 test for 3-way valve case and 20 test for 2-way valve case. These tests were performed at three levels of valve opening, total water flow rate and water supply temperature according to the design matrices establis
... Show MoreIn this paper new methods were presented based on technique of differences which is the difference- based modified jackknifed generalized ridge regression estimator(DMJGR) and difference-based generalized jackknifed ridge regression estimator(DGJR), in estimating the parameters of linear part of the partially linear model. As for the nonlinear part represented by the nonparametric function, it was estimated using Nadaraya Watson smoother. The partially linear model was compared using these proposed methods with other estimators based on differencing technique through the MSE comparison criterion in simulation study.
A total of 258 voluntary blood donors (males 101; females 157) in the age range of 18-52 yr among males and 18-55 yr among females were examined for Toxoplasma gondii antibodies (IgG), and (IgM) by immunological technique (Enzyme linked Immunosorbant Assay) during the period from March 2009 to April 2010. This study covered a wide range of factors including immunological, age ,sex , place of residence and symptoms that may have a possible relationship with toxoplasmosis. Results presented in this study showed clearly that 38 (14.7%) of individuals participated in this study having IgG Toxoplasma Ab, among those 10 samples (9.9%) were males and 28 samples (17.8%) were females. Moreover, we found the prevalence of IgM seropositivity in th
... Show MoreSimple, precise and economic batch and flow injection analysis (FIA)-spectrophotometric methods have been established for simultaneous determination of salbutamol sulfate (SLB) in bulk powder and pharmaceutical forms. Both methods based on diazotization coupling reaction of SLB with another drug compound (sulfadimidine) as a safe and green diazotization agent in alkaline medium. At 444 nm, the maximum absorption of the orange azo-dye product was observed. A thorough investigation of all chemical and physical factors was conducted for batch and FIA procedures to achieve high sensitivity. Under the optimized experimental variables, SLB obeys Beer’s law in the concentration range of 0.25-4 and 10-100 μg/mL with limits of detection of 0.0
... Show MoreSimple, precise and economic batch and flow injection analysis (FIA)-spectrophotometric methods have been established for simultaneous determination of salbutamol sulfate (SLB) in bulk powder and pharmaceutical forms. Both methods based on diazotization coupling reaction of SLB with another drug compound (sulfadimidine) as a safe and green diazotization agent in alkaline medium. At 444 nm, the maximum absorption of the orange azo-dye product was observed. A thorough investigation of all chemical and physical factors was conducted for batch and FIA procedures to achieve high sensitivity. Under the optimized experimental variables, SLB obeys Beer’s law in the concentration range of 0.25-4 and 10-100 μg/mL with limits of detection o
... Show MoreIn this research we prepared nanofibers by electrospinning from
poly (Vinyl Alcohol) /TiO2. The spectrum of the solution (Emission)
was studied and found to be at 772 nm, several process parameters
were such as concentration of TiO2 , and the effect of distance from
nozzle tip to the grounded collector (gap distance). The result of the
lower concentration of, the smaller the diameter of nanofiber is.
Increasing the gap distance will affect nanofibers diameter
The Dielectric properties of EP/TiO2 and MgO nanocomposite at
a frequency range of (102-106 Hz) were studied. The composite were
prepared with the state volume ratio (0, 0.05, 0.1) for EP/TiO2 and
MgO respectively. The impedance, dielectric constant and dielectric
loss were found decrease with frequency increase.
ِabstract:In this research we prepared nanofibers by electrospinning from poly (Vinyl Alcohol) /TiO2. The spectrum of the solution (Emission) was studied and found to be at 772 nm, several process parameters were such as concentration of TiO2 , and the effect of distance from nozzle tip to the grounded collector (gap distance). The result of the lower concentration of, the smaller the diameter of nanofiber is. Increasing the gap distance will affect nanofibers diameter.