Facile fabrication and structural elucidation of lignin based macromolecular green composites for multifunctional applications

The present work deals with the preparation and characterization of lignin based macromolecular polymeric composites and applications thereof. Here lignin is complexed with pectin and/ or gellan gum, to form two different macromolecular green composites LP and LPG. The best ratios screened out through evaluation of nanoparticle characterization and rheology, then confirmed by surface morphology. The superior thermal stability is proved by DSC analysis. The reaction groups involving in complexation are confirmed by FT-IR spectroscopic evaluation where the methoxy or methyl group of lignin interacts with the hydroxyl group of pectin and gellan gum to form nanocomposites. The reduced particle size and surface charge confirm the complexation due to interaction between ionizable functional groups. The applications of these composites are validated by their dye adsorption capacity and anti-microbial properties (after loading of green silver nanoparticles) which proves the multifunctional properties of novel composites. The maximum dye removal efficiency of both composites is independent of initial dye concentration. Dye adsorption capacity is best fitted by Freundlich adsorption isotherms that follow pseudo-second-order adsorption kinetics. The antibacterial study of developed silver nanoparticle loaded and unloaded composites shows wide spectrum activity against E. coli and S. aureus, with higher inhibition efficiency against gram-negative organism.     

Amorphous Silicon Thin-Film Transistor Backplanes Deposited at 200 °C on Clear Plastic for Lamination to Electrophoretic Displays

The transition of thin-film transistor (TFT) backplanes from rigid plate glass to flexible substrates requires the development of a generic TFT backplane technology on a clear plastic substrate. To be sufficiently stable under bias stress, amorphous-silicon (a-Si:H) TFTs must be deposited at elevated temperatures, therefore the substrate must withstand high temperatures. We fabricated a-Si:H TFT backplanes on a clear plastic substrate at 200degC. The measured stability of the TFTs under gate bias stress was superior to TFTs fabricated at 150degC. The substrate was dimensionally stable within the measurement resolution of 1, allowing for well-aligned 8 times 8 and 32 times 32 arrays of pixels. The operation of the backplane is demonstrated with an electrophoretic display. This result is a step toward the drop-in replacement of glass substrates by plastic foil.     

Adiabatic and friction heating on the open die extrusion of solid and hollow bodies

This paper deals with an experimental investigation concerning the open die extrusion (ODE) of three materials of varying physical properties and mechanical properties. Two geometrical configurations (solid and tube) and two methods (by direct and indirect techniques) were considered to examine the influence of these variables in the generation and retention of heat in the deformation zone with the objective of ensuring a greater achievable strain. Studies reveal that solid configuration supports the retention of heat as against tubular configuration. Low thermal conductivity, density, specific heat and high flow stress which characterise 99Ti make this material an excellent candidate for ODE as opposed to AISI 1020 steel and aluminium, which fail to meet all the above physical and mechanical properties. The indirect technique reduces the friction factor and thus enables greater strains to be achieved.     

A journey with prasad’s processing maps

The constitutive flow behavior of austenitic stainless steel types AISI 304L, 316L, and 304 in the temperature range of 873 K (600 °C) to 1473 K (1200 °C) and strain-rate range of 0.001 s⁻¹–100 s⁻¹ has been evaluated with a view to establishing processing-microstructure-property relationships during hot working. The technique adopted for the study of constitutive behavior is through establishing processing maps and instability maps, and interpreting them on the basis of dynamic materials model (DMM). The processing maps for 304L have revealed a domain of dynamic recrystallization (DRX) occurring at 1423 K (1150 °C) at 0.1 s⁻¹, which is the optimum condition for hot working of this material. The processing maps of 304 predict DRX domain at 1373 K (1100 °C) and 0.1 s⁻¹. Stainless steel type 316L undergoes DRX at 1523 K (1250 °C) and 0.05 s⁻¹. At 1173 K (900 °C) and 0.001 s⁻¹ this material undergoes dynamic recovery (DRY). In the temperature and strain rate regimes other than DRX and DRY domains, austenitic stainless steels exhibit flow localization. Large-scale experiments using rolling, forging, and extrusion processes were conducted with a view to validating the conclusions arrived at from the processing maps. The “safe” processing regime predicted by processing maps has been further refined using the values of apparent activation energy during deformation. The validity and the merit of this refining procedure have been demonstrated with an example of press forging trials on stainless steel 316L. The usefulness of this approach for manufacturing stainless steel tubes and hot rolled plates has been demonstrated.     

Composition Profiles and Functional Properties of Dietary Fiber Powder from Lime Residues: Effects of Pretreatment and Drying Methods

Lime residues after juice extraction have proven to be a potential raw material for producing dietary fiber (DF) powder due to their good functional properties. Compositions and antioxidant activity of DF powder from lime residues as affected by selected pretreatment (hot-water blanching and ethanolic soaking) and drying methods, viz. hot air drying, vacuum drying, and low-pressure superheated steam drying (LPSSD) at 60–80°C, were investigated. Fresh lime residues contained significant amounts of vitamin C, phenolic compounds, and flavonoids. Hesperidin was a major flavonoid and only one polymethoxyflavone (i.e., tangeretin) was detected in small amounts. A decrease in the amount of interested bioactive compounds and their antioxidant activity was noted at almost all steps of processing. Higher retention of bioactive compounds was noted when the residues were subject either to vacuum drying or LPSSD; the total antioxidant activities were 61–62% and 81–82% when being assessed by the β-carotene bleaching and DPPH assays, respectively. Vacuum drying at 80°C was the most suitable condition for preparing DF powder from lime residues due to its short required drying time and its ability to retain bioactive compounds. The in vitro analyses imply that DF powder prepared by vacuum drying at 80°C has the potential to reduce blood glucose and cholesterol levels by exhibiting high glucose retardation index (GRI) and bile acid retardation index (BRI).     

Separation of palladium from high level liquid waste of PUREX origin by solvent extraction and precipitation methods using oximes

Separation of palladium from high level liquid waste (HLLW) solution originated from the reprocessing of spent fuel by PUREX process is carried out by solvent extraction and precipitation methods using oximes. In solvent extraction, palladium is extracted from the waste using 1.1×10⁻²M α-benzoin oxime in Solvesso 100 as extractant. The loaded organic phase is scrubbed with water prior to the stripping of palladium using the strippants 0.05 M thiourea in 0.1 M HNO₃ and 4 M NH₄OH separately. The recovery of the method is found to be >99.5%. The method has been used to recover Pd in sub mg quantities from actual waste solution originated from the reprocessing of spent fuel from pressurised heavy water reactor (PHWR-HLLW). Studies are also carried out for the separation of palladium using an aqueous solution of sodium salt of dimethyl glyoxime (0.1% w/v) as precipitant. Various parameters which influence the precipitation of palladium such as concentration of the precipitant, concentration of nitric acid in the feed and the behaviour of uranium, plutonium and other fission products at the concentration level encountered in the waste are studied in detail. Under the optimized precipitation conditions separation of Pd is carried out from a synthetic PHWR-HLLW and the recovery is found to be >99.9%. The palladium product obtained from both the methods show high decontamination factors with respect to other fission products and constituents of the waste. Based on these results a scheme has been proposed for the recovery of palladium from HLLW.     

Gelation of Shark Meat under Mild Acidic Conditions: Physicochemical and Rheological Characterization of the Gel

Homogenate of washed shark meat in water was converted into a gel by lowering its pH to 3.5 by acetic acid. Unlike unacidified homogenate, water was strongly bound to the gel. The strength of the gel increased with increasing moisture content, while expressible water content was not affected. Gelation was associated with reduction in myosin heavy chain and sulfhydryl groups. Dynamic rheological measurements indicated viscoelastic nature of the gel. The storage modulus increased with increased temperature. The shear stress sweep of the gel dispersions as a function of temperature suggested pseudoplastic behavior.