Chemically and Green Synthesized ZnO Nanoparticles Alter Key Immunological Molecules in Common Carp (Cyprinus carpio) Skin Mucus

This study was conducted to compare the effects of commercially available (C) and green synthesized (GS) Zinc oxide nanoparticles (ZnO-NPs) on immunological responses of common carp (Cyprinus carpio) skin mucus. GS ZnO-NPs were generated using Thymus pubescent and characterized by UV–vis diffuse reflectance spectroscopy (DRS), Fourier-transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), scanning electron microscope (SEM), and energy-dispersive X-ray spectroscopy (EDX). Fish (n = 150) were randomly allocated into five groups in triplicate and received a waterborne concentration of 0% (control), 25%, and 50% of LC50 96 h of commercially available (C1 and C2) and green synthesized ZnO-NPs (GS1 and GS2) for 21 days. Results from XRD displayed ZnO-NPs with 58 nm in size and UV-vis DRS, EDX, and FT-IR analysis showed that some functional groups from plant extract bonded to the surface of NPs. The SEM images showed that ZnO-NPs have conical morphology. Acute toxicity study showed a higher dose of LC50_96h for green synthesized ZnO-NPs (78.9 mg.L⁻¹) compared to the commercial source (59.95 mg.L⁻¹). The highest activity of lysozyme and alternative complement activity (ACH50) were found in control and GS1 groups. A significant decrease in alkaline phosphatase activity (ALP) was found in C1 and C2 groups compared to other treatments. Protease activity (P) was significantly decreased in the C2 group compared to the control and GS groups. Total immunoglobulin (total Ig) content was the highest in the control. In addition, total Ig in the GS1 group was higher than GS2. The exposure to ZnO-NPs lowered total protein content in all experimental groups when compared to control. Present findings revealed lower induced immunosuppressive effects by green synthesized ZnO-NPs on key parameters of fish skin mucus.     

Naturally occurring halloysite nanotubes for enhanced durability of natural rubber/ethylene propylene diene monomer rubber vulcanizate

A facile approach of using halloysite nanotubes (HNTs) was proposed to address the durability performance demands of natural rubber (NR)/ethylene propylene diene monomer rubber (EPDM) blends and to protect them from the deleterious effects of the service environment including ozone, chemicals, abrasion, and cyclic loading. The introduction of HNTs substantially improved the stability of NR/EPDM when exposed to ozone (over fourfold enhancement with the addition of 5 phr HNTs). Moreover, the HNT-filled NR/EPDM vulcanizates offered approximately 66% reduction in the solvent-mediated swelling in comparison to the unfilled sample. Fatigue life studies showed that the HNT-reinforced NR/EPDM composite could withstand 30% more cycles to failure than the un-reinforced NR/EPDM blend. The effect of various HNT loading on the morphological, mechanical, physical, and rheological properties of nanocomposite vulcanizates based on NR/EPDM was also investigated. The morphological investigations revealed that the introduction of HNT into the NR/EPDM rubber matrix caused a rough morphology in fracture surface and a well-dispersed structure was obtained with the addition of up to 5 phr of HNTs. These findings were further supported by rheological, mechanical, and thermodynamical results.     

Compatibilized Polypropylene/Ethylene–Propylene–Diene-Monomer/Polyamide6 ternary blends: Effect of twin screw extruder processing parameters

Polypropylene (PP)/Polyamide6 (PA6)/Ethylene–Propylene–Diene-Monomer (EPDM) (70/15/15) ternary polymer blends compatibilized with Maleic-anhydride grafted EPDM (EPDM-g-MA) were prepared by melt blending using a twin screw extruder (TSE). Effect of TSE processing parameters including barrel temperature, screw speed and blending sequence on the mechanical properties of ternary polymer blends was investigated by application of Taguchi experimental design methodology. Three different levels of barrel temperature (220 °C, 230 °C, 240 °C), screw speed (90 rpm, 120 rpm, 150 rpm) and blending sequence (nominated as: S1, S2 and S3) were selected. The response variables were tensile properties and impact strength of the prepared samples which are directly affected by the blend microstructure. Investigation of the statistical–mathematical analysis results performed by the software depicted that the optimum processing conditions for the ternary blends investigated here, to achieve balanced tensile and impact properties, are 220 °C, 150 rpm and S2 blending sequence.     

Salep‐g‐poly(sodium acrylate)/alumina superabsorbent hydrogel composite as a smart material: Irradiation synthesis and investigation of its swelling behavior

A novel environmentally sensitive superabsorbent composite was synthesized via the gamma (γ)‐irradiation graft copolymerization of sodium acrylate onto a homogeneous blend of natural salep and alumina in an aqueous medium. The reaction parameters (i.e., acrylic acid amount, neutralization percentage, alumina/salep weight ratio, and γ‐irradiation total dose) affecting the water absorbency of the hydrogel composite were optimized by using a systematic method in order to achieve a composite with as high a swelling capacity as possible. FTIR spectroscopy was used to confirm the structure of the final product. Morphology of the synthesized composite was examined by scanning electron microscopy. The swelling behavior of the optimum superabsorbent composite was measured in various environments, and the results showed excellent on–off switching behaviors which made this novel smart composite material a nominee that can potentially be used in agriculture, pharmaceutics, and biosensors. J. VINYL ADDIT. TECHNOL., 2011. © 2011 Society of Plastics Engineers     

Preparation of carbon molecular sieve from lignocellulosic biomass: A review

A literature review on preparation of carbon molecular sieve (CMS) from lignocellulosic biomass is presented. The effect of various operation parameters such as pyrolytic temperature, flow rate of the carbonizing agent and time of pyrolysis on the carbonization of the lignocellulosic biomass as a carbon precursor was reviewed. Various physical and chemical processes for the activation of the biomass-based char and their effects on textural properties of the activated char were discussed. Conversion of activated chars to CMS as the final stage of the preparation process through different techniques of chemical vapor deposition (CVD) and controlled pyrolysis was assessed. Survey of literature revealed that production of CMS with BET surface area of 1247 m²/g and micropore volume of 0.51 cm³/g, under appropriate conditions has been reported. Also, maximum selectivity of 7.6 and 400 for separation of O₂/N₂ and CO₂/CH₄ was devoted to palm shell and coconut shell-based CMS, respectively.     

Novel Nanoporous Superabsorbent Hydrogel Based on Poly(acrylic acid) Grafted onto Salep: Synthesis and Swelling Behavior

Hydrogels of poly(acrylic acid) grafted onto salep with excellent water absorption and water retention abilities under neutral conditions were successfully synthesized for the first time and employed for different applications. The effect of reaction variables to achieve maximum swelling capacity was investigated. In our procedure, ammonium persulfate (APS) as a water‐soluble initiator and methylenebisacrylamide (MBA) as a suitable crosslinking agent were used and the best synthesis conditions described. The structure of the final product was confirmed by Fourier‐transform infrared (FTIR) spectroscopy, scanning electron microscopy SEM and TGA analysis and a mechanism for superabsorbent hydrogel formation was also suggested. The study of the surface morphology of hydrogels using SEM showed a highly nanoporous and cellular structure for the sample obtained under optimized condition. Furthermore, several factors which influence the water uptake of hydrogels, such as pH of water, sensitivity to salt solutions and solvent mixtures were examined.     

Synthesis and characterization of porous nanostructured Ni/PdNi electrode towards electrooxidation of borohydride

An electrochemical approach to nanostructured Ni/PdNi catalyst design using the electrodeposition process and galvanic replacement technique is presented. The procedure consisted of the electrodeposition of Ni–Zn on the Ni coating, with subsequent replacement of the zinc by palladium at open circuit in a palladium containing alkaline solution. The surface morphologies and compositions of coatings were determined by energy dispersive X-ray and scanning electron microscopy techniques. The results showed that the Ni/PdNi coatings were porous, and composed of discrete Pd nanoparticles with the crystallite size of about 58 nm. The electrocatalytic activity of Ni/PdNi electrodes towards electrooxidation of borohydride was studied using cyclic voltammetry and electrochemical impedance spectroscopy techniques. The anodic peak current density was found to be up to eight times higher on Ni/PdNi electrode for sodium borohydride compared to that for flat palladium. Therefore, the Ni/PdNi catalysts can be potential anode catalysts for the direct borohydride fuel cell.     

Minimizing the number of tardy jobs under piecewise-linear deterioration

In this paper, we consider a single machine scheduling problem with piecewise-linear deterioration where its objective is to minimize the number of tardy jobs, in which the processing time of each job depends on its starting time where all the jobs have a specific deterioration rate. The problem is known to be NP-hard; therefore a Branch and Bound algorithm and a heuristic algorithm with O(n²) are proposed. The proposed heuristic algorithm has been utilized for solving large scale problems and upper bound of the B&B algorithm. Computational experiments on 1840 problems demonstrate that the Branch and Bound procedure can solve problems with 28 jobs and 85.4% of all the sample problems optimally showing the high capability of the proposed procedure. Also it is shown that the average value of the ratio of optimal answer to the heuristic algorithm result with the objective ∑(1-_Ui)$\sum (1-U_i)$ is at last 1.08 which is more efficient in contrast to other proposed algorithms in related studies in the literature. According to high efficacy of the heuristic algorithm, large scale samples are also being solved and the results are presented. A specific form of this problem is also being considered and it is proven that the B&B procedure can handle problems with more jobs even up to 44 jobs.