Evaluation of process condition impact on copper and lead ions removal from water using goethite incorporated nanocomposite ultrafiltration adsorptive membranes.

Polyacrylonitrile (PAN) adsorptive membrane incorporated with nanosize-goethite (α-FeO(OH)) hydrous metal oxide particles (GNPs), prepared with optimal flux and Cu(II) removal in the previous study, was used to evaluate the process parameter on the Cu(II) removal. Box-Behnken Design (BBD) based on the Response Surface Methodology (RSM) was employed to evaluate the impact of Cu(II) feed solution characteristics such as pH, initial concentration of metal ion, and transmembrane pressure (TMP) on copper removal efficiency. The outcomes indicated that the RSM optimization technique could be utilized as an applicable method to find the optimum condition for the maximum Cu(II) removal with slight variance compared with the experimentally measured data. The effect of each process parameter and the coupling effect of parameters on the Cu(II) removal was assessed. Finally, the optimum condition of pH, Cu(II) concentration, and transmembrane pressure (TMP) to obtain high copper removal efficiency was decided. In the optimum condition of the Cu(II) removal, the removal of lead (Pb(II)) metal ion was evaluated by the same membrane

Assessment of CGCM 3.1 wind field in the Persian Gulf

Increasing of the greenhouse gases emission causes the climate changes. Therefore, usage of the marine renewable energy resources such as wind and wave energies has been increased during the last decades. Climate variability can change the wind and consequently wave patterns and the available energy amounts. Therefore, assessment of the potential effect of climate change on the wind regime is important. In this paper, wind characteristics obtained from a global climate model (CGCM 3.1) is used for assessing the effects of climate change on the wind regime in the Persian Gulf. CGCM 3.1 results were compared quantitatively with those of ECMWF in the Persian Gulf and the results showed that in comparison to ECMWF, CGCM 3.1 wind speeds are mostly underestimated for both average and maximum values. Dominant wind directions represented by two wind fields are nearly similar except for a point located in Strait of Hormuz. Variations of the annual wind speed in this area were also evaluated until 2100 and time series of annual averages of the wind speeds and statistical analysis indicate a decreasing trend in all points in the domain. Variation of wind speed frequency based on CGCM 3.1 winds was also assessed for different intervals and the results showed that the variations of wind speed frequencies are marginal. Although there is a insignificant reduction in the average wind speed, this can lead to large variations in the wind and wave energies and also extreme values of wave characteristics.Full Tex

Can 3D imaging and digital software increase the ability to predict dental arch form after orthodontic treatment?

Introduction: This study aimed to evaluate the ability of dental clinicians to predict posttreatment dental arch forms in patients with malocclusion with the aid of 3D imaging and digital software in comparison with a conventional method. Methods: Pretreatment and posttreatment dental plaster casts of 100 patients (200 maxillary models and 200 mandibular models) were selected. Three orthodontists selected the best-fitted archwires among 5 commercially available preformed nickel-titanium archwires using 2 methods. In the conventional method, they fit the archwires to pretreatment casts, and in the digital method, they fit the scanned wire to a 3D digital model, using Ortho-Aid, a locally developed 3D software, using clinical bracket points as reference for wire fitness. The predicted posttreatment archwire in each method was compared with the best-fit archwire on the actual posttreatment model of each patient in both methods, and the level of agreement was calculated. The interobserver agreement between the 3 orthodontists in each method was evaluated using intraclass correlation coefficient and the Dahlberg formula. Results: Orthodontists predicted the final treatment outcome in 50% of cases using the conventional method and 58% using the digital method. However, the range of method error was significantly higher in the conventional method (0.425-3.853 mm for the conventional vs 0.451-0.584 mm for the digital). Conclusions: Although the clinicians' ability to predict the final dental arch form after orthodontic treatment and the agreement between clinicians increased by the use of digital equipment, orthodontists can predict the final arch form in about 60% of patients

Developing a thin film composite membrane with hydrophilic sulfonated substrate on nonwoven backing fabric support for forward osmosis

This study describes the fabrication of sulfonated polyethersulfone (SPES) as a super-hydrophilic substrate for developing a composite forward osmosis (FO) membrane on a nonwoven backing fabric support. SPES was prepared through an indirect sulfonation procedure and then blended with PES at a certain ratio. Applying SPES as the substrate affected membrane properties, such as porosity, total thickness, morphology, and hydrophilicity. The PES-based FO membrane with a finger-like structure had lower performance in comparison with the SPES based FO membrane having a sponge-like structure. The finger-like morphology changed to a sponge-like morphology with the increase in the SPES concentration. The FO membrane based on a more hydrophilic substrate via sulfonation had a sponge morphology and showed better water flux results. Water flux of 26.1 L m−2 h−1 and specific reverse solute flux of 0.66 g L−1 were attained at a SPES blend ratio of 50 wt % when 3 M NaCl was used as the draw solution and DI water as feed solution under the FO mode. This work offers significant insights into understanding the factors affecting FO membrane performance, such as porosity and functionality