STUDIES ON THE EFFECT OF GERMINATION TIME AND TEMPERATURE ON MALTING OF RICE

The effect of germination conditions on rice malt quality was studied by germinating rice for different periods of time up to 7 days over a range of temperatures (22° to 32°C). Germination time and temperature had a significant effect on rice malt diastatic power, cold and hot water extracts, total reducing sugars, and free alpha amino nitrogen. In general, diastatic power, cold water extract, hot water extract, total reducing sugars and free alpha amino nitrogen, all increased with germination time and temperature. Germination temperatures of 28°C and 30°C were good for the development of diastatic power, cold water extract, hot water extract, total reducing sugars and free alpha amino nitrogen. However germinating at 30°C gave maximum result. The mashing trials with rice malted for 6 days showed a slow and incomplete saccharification, slow filtration rate, and high total available extract in spent grains.     

Miscibility and morphological properties of quaternized polysulfone blends with polystyrene and poly(4‐vinylpyridine)

Quaternized polysulfones were synthesized by the quaternization reaction of chloromethylated polysulfone with different tertiary amines −N,N‐dimethylethylamine (DMEA) and N,N‐dimethyloctylamine (DMOA), respectively. New blends from these quaternized polysulfones (PSF‐DMEA or PSF‐DMOA) with polystyrene (PS) or poly(4‐vinylpyridine) (P4VP) were prepared by the solution casting method. Pure quaternized polysulfones, in N,N‐dimethylformamide (DMF)/methanol (MeOH) and DMF/water solvent/nonsolvent mixtures, and their blends with PS and P4VP, as well, were investigated by shear viscometry and viscoelasticity, atomic force microscopy, differential scanning calorimetry, and surface properties. The results obtained revealed that the blends have good miscibility. Surface morphology is characterized by roughness and nodules formations, depending on the alkyl radical lengths, composition of the polymer mixtures, including specific electron‐donor or electron‐acceptor characteristics of polymers. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers     

A new material model for 2D numerical simulation of serrated chip formation when machining titanium alloy Ti–6Al–4V

A new material constitutive law is implemented in a 2D finite element model to analyse the chip formation and shear localisation when machining titanium alloys. The numerical simulations use a commercial finite element software (FORGE 2005^®) able to solve complex thermo-mechanical problems. One of the main machining characteristics of titanium alloys is to produce segmented chips for a wide range of cutting speeds and feeds. The present study assumes that the chip segmentation is only induced by adiabatic shear banding, without material failure in the primary shear zone. The new developed model takes into account the influence of strain, strain rate and temperature on the flow stress and also introduces a strain softening effect. The tool chip friction is managed by a combined Coulomb–Tresca friction law. The influence of two different strain softening levels and machining parameters on the cutting forces and chip morphology has been studied. Chip morphology, cutting and feed forces predicted by numerical simulations are compared with experimental results.     

Copolymerization of the pair maleic anhydride–dicyclopentadiene: I. Copolymerization and post‐copolymerization at high conversion

The present study describes the kinetic investigation of the complex binary copolymerization system maleic anhydride (MA)—dicyclopentadiene (DCPD). All syntheses were carried out in homogeneous solution; high conversions in soluble and linear copolymer are achievable when starting from an equimolecular monomer feed. Excess of DCPD would limit the attainable conversions, while surplus of MA would induce crosslinking of the copolymers. The findings of the thorough kinetic study were sustained by structural assessment from IR and NMR spectra recorded for various copolymers, both soluble and gels. Copyright © 2004 Society of Chemical Industry     

Sensitization of as Rolled and Stable Annealed Alloy 625

Alloy 625 is used as cladding material in the oil and gas industry. Different annealing conditions are used, these are stable annealed and as rolled. Both conditions have been isothermally sensitized in a laboratory resistance furnace. The annealing temperature was up to 1050?°C and the annealing time up to 10 h. Susceptibility to intergranular corrosion has been investigated by means of a conventional immersion tests according to ASTM G28A and the Double Loop—Electrochemical Potentiokinetic Reactivation Test (DL-EPR method). Scanning electron microscopy (SEM) was used to evaluate microstructure and type of attack after testing. The chemical composition of precipitated phases was characterized by SEM and Transmission Electron Microscopy (TEM). High-resolution investigations with concentration profiles proved high molybdenum precipitates to determine the degree of sensitization.     

Viscoelastic behaviour of self‐assembling polyurethane and poly(vinyl alcohol)

The rheological behaviour of polyurethane (PU) and poly(vinyl alcohol) (PVA) was investigated in aqueous solution and the hydrogel state. The dependence of viscosity on polymer concentration is discussed. The formation of supramolecular structures induced by temperature increase or shear conditions was evidenced. In PU solutions, as temperature increases, a self‐assembling process occurs due to hydrogen bonding and hydrophobic interactions determining a thermoreversible hydrogel formation. In creep and recovery tests, the weak PU network presents high elasticity only at low shear stress (below 10 Pa); it recovers only 15%–20% of strain above 40 Pa and the hydrogel structure fails at high shear stress (above 150 Pa). Also, PU hydrogel is not able to recover its structure after being submitted to successive low and high deformations. In PVA solutions, a shear induced aggregation was observed at 37 °C. PVA hydrogels obtained by the freezing–thawing method present high elasticity and stability due to the strong polymer–polymer interactions established between the polymer chains. Physical networks based on PU/PVA mixtures synergistically combine the characteristics of the two polymers, showing high elasticity when a shear stress up to 3000 Pa is applied during the creep test followed by a fast recovery of the hydrogel structure after exhibiting successive levels of deformation (self‐healing ability). Therefore, these hydrogels are suitable materials for tissue engineering applications. © 2019 Society of Chemical Industry     

Enhanced Suppression of Immune Cells In Vitro by MSC Overexpressing FasL

Mesenchymal stromal cells (MSC) display several mechanisms of action that may be harnessed for therapeutic purposes. One of their most attractive features is their immunomodulatory activity that has been extensively characterized both in vitro and in vivo. While this activity has proven to be very efficient, it is transient. We aimed to enhance it by transforming MSC to overexpress a first apoptosis signal (Fas) ligand (FasL). In this study, our goal was to induce FasL overexpression through adenoviral transduction in MSC to improve their immunomodulatory activity. We characterized the impact of FasL overexpression on the morphology, proliferation, viability, phenotype, multilineage differentiation potential and immunomodulation of MSC. Moreover, we determined their suppressive properties in mixed reactions with A20 cells, as well as with stimulated splenocytes. Our findings demonstrate that FasL-overexpressing MSC exhibit improved immunosuppressive properties, while maintaining their MSC-characteristic features. In conclusion, we establish, in a proof-of-concept set-up, that FasL-overexpressing MSC represent good candidates for therapeutic intervention targeted at autoimmune disorders.