Catalytic ozonation process using PAC/γ-Fe2O3 to Alizarin Red S degradation from aqueous solutions: a batch study

In the catalytic ozonation process used in this study, adsorption and chemical reactions were performed at the catalyst surface. This process can increase the efficiency of plain ozonation. The main aim of this study was to investigate the efficiency of the catalytic ozonation process in removing Alizarin Red S dye from colored water by Fe₂O₃ coated on PAC. In this work, activated carbon powder/γ-Fe₂O₃ nano-composite was modified. The BET results showed that the surface area in PAC and PAC-γ-Fe₂O₃ nano-composite was 654 and 450?m² g^?1, respectively. In this study, the best pH for removal of ARS was found to be 9. At a higher pH, the efficiency of the process decreased gradually. According to studies, catalysts increase surface area and active sites for more ozone degradation. Also, the characterization of the catalyst will play a very important role in the COP. Also, the maximum removal efficiency was observed in catalyst dose 1.1?g l^?1. The study results showed that the highest mineralization rate in ARS degradation was related to O₃/PAC/γ-Fe₂O₃. The amount of mineralization in the SOP, O₃-PAC, and O₃/PAC/γ-Fe₂O₃ was 13, 25, and 40%, respectively. The finding of mineralization of ARS using the SOP reflected the low power of the ozonation process for the mineralization of pollutants.     

Designing and synthesis of bis(2,4-dihydroxybenzylidene)-1,6-diaminohexane and its efficient application as neutral carrier for preparation of new copper selective electrode

A new copper carbon paste electrode (CPE) based on incorporation bis(2, 4-dihydroxybenzyliden)-1,6-diaminohexane (DHBDAH) in graphite powder matrix has been described. The influence of variables including an amount of graphite, sodium tetraphenylborate (NaTPB), DHBDAH and nujol on the Cu²⁺ carbon paste electrode response was studied and optimized. The optimum carbon paste composition was set as follows, graphite powder: NaTPB: Nujol: DHBDAH with amount of 150:2.3:30:4 mg, respectively. At the optimum conditions, the potential response is linear over the concentration range of 5.0 × 10^? 8 to 1.0 × 10^? 1 mol L^? 1 with a Nernstian slope of 29.5 ± 1.1 mV per decade of Cu²⁺ ion concentration. The good performance of electrode such as low detection limit of (LOD) (4 × 10^? 8 mol L^? 1), wide applicable pH range (2.5–5.5), fast response time (?10 s) and adequate shelf life (69 days) indicate the utility of the proposed electrode for evaluation of Cu²⁺ ion content in various analysis. Due to moderate potentiometric selectivity coefficients of proposed electrode obtained by fixed interference method (FIM) and separate solution method (SSM), the proposed electrode successfully can be applied for the determination of Cu²⁺ ions content in some real samples.     

Fabrication of PLA/MWCNT/Fe3O4 composite nanofibers for leukemia cancer cells

The efficient delivery of daunorubicin loaded poly (lactic acid) (PLA)/multiwalled carbon nanotubes (MWCNT)/Fe₃O₄ composite nanofibers was investigated. The synthesized nanofibers were characterized using SEM, TEM, and XRD analysis. The proliferation inhibition effect of PLA/MWCNT/Fe₃O₄ nanofibrous scaffolds on leukemia K562 cell lines was investigated. The effect of nanofiber concentration on the daunorubicin delivery in the absence and presence of external magnetic field was also evaluated. The results indicated that the incorporation of daunorubicin into the prepared nanofibrous scaffold under applied magnetic field could have synergistic cytotoxic effect on leukemia cancer cells. The drug release mechanism followed the non-Fickian transport.     

Multimodal 3D American sign language recognition for static alphabet and numbers using hand joints and shape coding

Multimedia Tools and Applications - American sign language recognition is still a research focus in computer vision community. Recently, most researches mainly extract low-level features for hand...     

Efficient Removal of Methylene Blue Using a Hybrid Organic–Inorganic Hydrogel Nanocomposite Adsorbent Based on Sodium Alginate–Silicone Dioxide

In this work, we reported synthesis, structure characterization and methylene blue (MB) adsorption of a novel organic–inorganic hydrogel nanocomposite adsorbent (HNA) based on sodium alginate (NaAlg) and silicone dioxide nanoparticles (SiO₂-NPs). The HNAs were prepared using grafting of acrylic acid (AA) onto NaAlg by using ammonium persulfate as a free radical initiator and methylene bisacrylamide as a crosslinker in the presence of SiO₂-NPs, which synthesized in situ from the base-catalyzed hydrolysis of tetraethylorthosilicate (TEOS). The structure of HNAs were characterized by FTIR, SEM, EDX, TEM, XRD, UV–Vis and TGA techniques and a proposed mechanism for preparation of adsorbents was also suggested. The swelling capacity of HNAs was examined in buffer solutions with pH ranged 1.0–14.0. The nanocomposites exhibited a pH-responsiveness character so that a swelling-deswelling pulsatile behavior was recorded at pHs 2.0 and 9.0. The swelling kinetics of HNA was also preliminary investigated. Moreover, the effects of agitation time, pH, initial dye concentration, adsorbent dose, TEOS content, AA concentration and temperature were optimized with respect to dye adsorption capacity of HNAs in detail. Furthermore, the kinetic and adsorption isotherm of MB dye onto HNAs were investigated in detail. The HNAs also showed excellent regeneration capacity after five consecutive cycles of dye adsorption–desorption. In general, the results indicated that the synthesized adsorbents with biodegradability and biocompability properties can be used in wastewater treatment via dye adsorption.     

Investigation of the properties of conductive hydrogel composite containing Zn particles

In this work, the conductive hydrogel composites containing Zn particle synthesized and their electrical and thermal properties were investigated. Polyacrylamide/Zn composites were synthesized by free radical polymerization in aqueous solution. The effect of preparation conditions such as the influence of crosslinker amount, initiator amount, Zn amount, and water absorbency on electrical conductivity of hydrogel was investigated. The effect of preparation conditions on thermal properties has been characterized using thermogravimetric analysis (TGA) method. The structures of metal‐composites were evaluated by FTIR and scanning electron microscopy (SEM) methods. SEM revealed a more uniform pore size when Zn particles were used when compared with pure polyacrylamide. TGA curves showed that both hydrogels were stable upto 600°C. The Zn/polyacrylamide hydrogels have a good conductivity of 4.30 mS cm^?1. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Hydrogen adsorption,structural, electronic,and spectroscopic properties of C32, B16N16, and B8C24 by DFT calculations

We used DFT calculations at B3LYP/6-31G(d) level of theory to investigate the structural, electronic and spectral properties of C₃₂, B₁₆N₁₆, and B₈C₂₄ nanocages. The C₃₂ found as the most stable one and the bond lengths was approximately constant for the considered nanocages. We also found that B₁₆N₁₆ has greater atomic charges than C₃₂ and B₈C₂₄. Very low conductivity and reactivity of B₁₆N₁₆, and higher conductivity and reactivity of B₈C₂₄ and C₃₂ were also revealed in this research. C₃₂ is the best electron donor cage and B₈C₂₄ is the best electron acceptor among the studied fullerenes. Simple infrared spectrum of fullerenes was revealed in which a few spectral regions can be identified as fingerprints of related samples. At last the binding energy of hydrogen molecules with the fullerenes was investigated.     

Synthesis of polyaniline/graphite composite as a cathode of Zn-polyaniline rechargeable battery

The characteristics of polyaniline/graphite composites (PANi/G) have been studied in aqueous electrolyte. PANi/G films with different graphite particle sizes were deposited on a platinum electrode by means of cyclic voltammetry. The film was employed as a positive electrode (cathode) for a Zn-PANi/G secondary battery containing 1.0 M ZnCl₂ and 0.5 M NH₄Cl electrolyte at pH 4.0. The cells were charged and discharged under a constant current of 0.6 mA cm⁻². The assembled battery showed an open-circuit voltage (OCV) of 1.55 V. All the batteries were discharge to a cut off voltage of 0.7 V. Maximum discharge capacity of the Zn-PANi/G battery was 142.4 Ah kg⁻¹ with a columbic efficiency of 97–100% over at least 200 cycles. The mid-point voltage (MPV) and specific energy were 1.14 V and 162.3 Wh kg⁻¹, respectively. The constructed battery showed a good recycleability. The structure of these polymer films was characterized by FTIR and UV–vis spectroscopies. Electrochemical impedance spectroscopy (EIS) was used as a powerful tool for investigation of charge transfer resistance in cathode material. The scanning electron microscopy (SEM) was employed as a morphology indicator of the cathodes.