Study of the effect of processing conditions on the co‐injection of PBS/PBAT and PTT/PBT blends for parts with increased bio‐content

This work studies the effect of processing parameters on mechanical properties and material distribution of co‐injected polymer blends within a complex mold shape. A partially bio‐sourced blend of poly(butylene terephthalate) and poly(trimethylene terephthalate) PTT/PBT was used for the core, with a tough biodegradable blend of poly (butylene succinate) and poly (butylene adipate‐co‐terephthalate) PBS/PBAT for the skin. A ½ factorial design of experiments is used to identify significant processing parameters from skin and core melt temperatures, injection speed and pressure, and mold temperature. Interactions between the processing effects are considered, and the resulting statistical data produced accurate linear models indicating that the co‐injection of the two blends can be controlled. Impact strength of the normally brittle PTT/PBT blend is shown to increase significantly with co‐injection and variations in core to skin volume ratios to have a determining role in the overall impact strength. Scanning electron microscope images were taken of co‐injected tensile samples with the PBS/PBAT skin dissolved displaying variations of mechanical interlocking occurring between the two blends. © 2014 The Authors Journal of Applied Polymer Science Published by Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41278.     

Application of electrostatic precipitator in collection of smoke particles from hospital wastes combustion

The paper reports the development and implementation of a cost-effective electrostatic precipitator (ESP) prototype for the medical wastes incinerator of university hospital centre (CHU) of Sidi-Bel-Abbes, using a water washing system for cleaning electrodes. The impact of medical waste incineration on human health is a topical debate. The incineration process is a safe mode of disposal [OK] of such waste, but it is not an effective solution and needs a pollution control system. Generally, in Africa, cost is the major constraint for manufacturers and users. A half-scale ESP model was initially used for an experimental study in the laboratory. Thereafter, a full-scale model was produced and installed for the incinerator based on the optimal values obtained from this preliminary study.     

Numerical Modeling of Ti Deformation for the Development of a Titanium and Stainless Steel Transition Joint

Finite element analysis (FEA) was used to model the joining of titanium grade 2 (Ti) to AISI 321 stainless steel (SS) transition joint of lap configuration with grooves at the interface on SS side. The hot forming of Ti for filling the grooves without defects was simulated. FEA involving large plastic flow with sticking friction condition was initially validated using compression test on cylindrical specimen at 900 °C. The barreled shape and a no-deformation zone in the sample predicted by FEA matched with those of the compression experiments. For the joining process, FEA computed the distribution of strain and hydrostatic stress in Ti and the minimum ram load required for a defect-free joint. The hot forming parameters for Ti to fill the grooves without defects and any geometrical distortion of the die were found to be 0.001 s^?1 at 900 °C. Using these conditions a defect-free Ti-SS joint was experimentally produced.     

Adsorption‐concentration polarization model for ultrafiltration in mixed matrix membrane

Adsorption has been found to be significant in ultrafiltration by mixed matrix membrane. Removal of very low molecular weight solutes compared to the molecular weight cut off of the membrane is facilitated by adsorption. The modeling of the adsorption coupled with concentration polarization is presented based on the mathematical approach developed by Gekas et al. (Gekas et al. Chem Eng Sci. 1993;48:2753–2765), from the first principles. However, extensive modifications were included in theoretical development including those suggested by Ruiz‐Bevia et al. (Ruiz‐Bevia et al. Chem Eng Sci. 1997;52:2343–2352). The developed model captured the rejection dynamics with the help of retention factor. The model equations were solved under the framework of boundary layer analysis, using the integral approach. Effects of the adsorption isotherm and the different parameters affecting the system performance were also investigated. Further, experimental validation of the model results with two different mixed matrix ultrafiltration studies was also elucidated. © 2014 American Institute of Chemical Engineers AIChE J, 60: 2354–2364, 2014     

Modulatory Effects of Biosynthesized Gold Nanoparticles Conjugated with Curcumin and Paclitaxel on Tumorigenesis and Metastatic Pathways—In Vitro and In Vivo Studies

Background: Breast cancer is the most common cancer in women globally, and diagnosing it early and finding potential drug candidates against multi-drug resistant metastatic breast cancers provide the possibilities of better treatment and extending life. Methods: The current study aimed to evaluate the synergistic anti-metastatic activity of Curcumin (Cur) and Paclitaxel (Pacli) individually, the combination of Curcumin–Paclitaxel (CP), and also in conjugation with gold nanoparticles (AuNP–Curcumin (Au-C), AuNP–Paclitaxel (Au-P), and AuNP–Curcumin–Paclitaxel (Au-CP)) in various in vitro and in vivo models. Results: The results from combination treatments of CP and Au-CP demonstrated excellent synergistic cytotoxic effects in triple-negative breast cancer cell lines (MDA MB 231 and 4T1) in in vitro and in vivo mouse models. Detailed mechanistic studies were performed that reveal that the anti-cancer effects were associated with the downregulation of the expression of VEGF, CYCLIN-D1, and STAT-3 genes and upregulation of the apoptotic Caspase-9 gene. The group of mice that received CP combination therapy (with and without gold nanoparticles) showed a significant reduction in the size of tumor when compared to the Pacli alone treatment and control groups. Conclusions: Together, the results suggest that the delivery of gold conjugated Au-CP formulations may help in modulating the outcomes of chemotherapy. The present study is well supported with observations from cell-based assays, molecular and histopathological analyses.     

Managing the Topological Expansion of Computer Networks in an Optimal Way

This article describes a subgradient-based near-optimal heuristic algorithm designed for minimizing the search of links that need to be added to an existing telecommunications network to enhance the survivability and routability of the network.     

Performance Evaluation and Biodegradation Study of Polyvinyl Chloride Films with Castor Oil-based Plasticizer

In the present study, a renewable resource-based plasticizer was synthesized by the lipase-catalyzed esterification reaction of furfuryl alcohol (FA) and castor oil fatty acid (COFA). The resultant ester (FA-COFA ester) was used as secondary plasticizers to the polyvinyl chloride (PVC) films. The PVC films were formulated using the combination of a conventional plasticizer di-butyl phthalate (DBP) and FA-COFA ester as a secondary plasticizer at different concentrations. Films were characterized by X-ray diffraction analysis, scanning electron microscopy, thermal analysis, mechanical performance, and migration stability. A biodegradability study of the PVC films showed increased degradability with increasing concentration of the FA-COFA ester in the PVC film. The study showed that ester of FA and COFA could be a substitute of DBP by as much as 80% of the total plasticizer with improved elongation and tensile properties, and such a kind of sustainable resource-based PVC blend films could be used as a good packaging material with biodegradable property.     

Statistical design of sustainable composites from poly(lactic acid) and grape pomace

Biocomposites from poly(lactic acid) (PLA) and grape pomace (GP) were created via injection molding to examine the effects of GP in a PLA matrix. To optimize the mechanical performance the biocomposites were compatibilized with maleic anhydride grafted PLA (MA-g-PLA). The objective of this work was to create a model that could accurately predict the mechanical properties of GP/PLA biocomposites. A region of feasibility for the biocomposites was determined using a statistical design of experiments. Linear regression was used to model the mechanical performance and predicted results with an error of 10% for both tensile and flexural strength and 16% for impact strength. The model was verified with a biocomposite of PLA/GP/MA-g-PLA with a ratio of 62/36/2. This biocomposite had a tensile strength, flexural modulus, and impact strength of 25.8 MPa, 40.0 MPa, and 18.4 J/m, respectively. It was found that a linear model can accurately predict the mechanical properties of PLA/GP/MA-g-PLA biocomposites.