In-vitro digestibility,textural and quality characteristics of ditalini pasta fortified with green banana flour and its type -IV modified starch

Resistant starch in unripe banana offers a possibility to alter the glycemic properties in convenience foods, such as pasta. In this study, pasta formulations were tried by replacing 30% semolina with varying proportions of green banana flour (GBF) and banana-modified starch (MS). The effect of substitution on physicochemical and functional properties, including in-vitro starch digestibility, antioxidant property and consumer acceptability, was evaluated. Among the composite flours, MS recorded higher swelling power and water holding capacity. The replacement of semolina with GBF resulted in higher resistant starch, 4–5 times enhanced indigestible fraction, phenols, flavonoids and antioxidant activity in pasta. Pronounced increment was also observed in potassium, calcium and magnesium content in blended pasta. Optimal cooking time was reduced with the addition of GBF, whereas it was enhanced with MS. GBF and MS in the blends, decreased the hydrolysis rate (up to 24%) and glycemic index (up to 17%) of pasta. However, the addition of MS beyond 10% negatively influenced springiness and chewiness. Microstructural studies explained the positive structural changes with the addition of GBF and MS. Sensory attributes disclosed that the addition of 25% GBF and 5% MS is a desirable proportion for pasta with a functional characteristics.     

Structural,electrical and electrochemical properties of polyacrylonitrile-ammonium hexaflurophosphate polymer electrolyte system

Polyacrylonitrile (PAN) based polymer electrolyte membranes complexed with Ammonium hexafluorophosphate (NH₄PF₆) with different molar concentration are prepared by solution casting method. Increase in the amorphous nature by the addition of Ammonium salt and the formation of polymer-salt complex are confirmed by X ray diffraction studies and infrared spectroscopy respectively. The glass transition temperature is measured for all membranes and it showed a lowest value for the PAN complexed with 20 mol% of NH₄PF₆. Electrical properties are studied by AC impedance spectroscopy. An ionic conductivity of the order of 10^?3 Scm^?1 is obtained for the 80 PAN / 20 NH₄PF₆ polymer electrolyte. Conductivity, dielectric and modulus spectra from the impedance data are analysed to understand the ionic transport mechanism. Transference number measurement is done to study the ionic contribution to the charge transport. A proton battery with the configuration, Zn+ ZnSO₄. 7H₂O /80 PAN / 20 NH₄PF₆ / PbO₂ +V₂O₅ has been constructed and its discharge characteristics are studied.     

Performance of a divided flow exchanger

An analysis is presented of a 1-2 divided flow exchanger where the temperature of shell and tube streams depend on tube arrangement. Effect of having unbalanced tube passes is assessed for two possible cases. Graphs are plotted that show the variation of thermal effectiveness and logarithmic mean temperature difference correction factor with ratio of heat capacity rates and number of transfer units. Combination of such exchangers is also studied.     

Biopolymer agar‐agar doped with NH4SCN as solid polymer electrolyte for electrochemical cell application

A new polymer electrolyte based on the biopolymer Agar‐Agar doped with ammonium thiocyanate (NH₄SCN) has been prepared and characterized by FTIR analysis, X‐ray diffraction measurements, AC impedance spectroscopy, transference number measurements, and DSC analysis. The Fourier transform infrared analysis confirms the complex formation between agar and NH₄SCN. The amorphous nature of the polymer electrolyte has been revealed from X‐ray diffraction analysis. The highest ionic conductivity has been observed for the sample of composition 1:1 between Agar and NH₄SCN. As a function of temperature, the ionic conductivity of this sample exhibits Arrhenius behavior increasing from 1.03 × 10^?3 S cm^?1 at ambient temperature to 3.16 × 10^?3 S cm^?1 at 343 K. The transference number has been estimated by the dc polarization method, and it has been proven that the conducting species are predominantly cations. Using the highest conductivity polymer electrolyte, solid state electrochemical cell has been fabricated and cell parameters are reported. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44702.     

1H NMR,thermal, and conductivity studies on PVAc based gel polymer electrolytes

The lithium‐ion conducting gel polymer electrolytes (GPE), PVAc‐DMF‐LiClO₄ of various compositions have been prepared by solution casting technique. ¹H NMR results reveal the existence of DMF in the gel polymer electrolytes at ambient temperature. Structure and surface morphology characterization have been studied by X‐ray diffraction analysis (XRD) and scanning electron microscopy (SEM) measurements. Thermal and conductivity behavior of polymer‐ and plasticizer‐salt complexes have been studied by differential scanning calorimetry (DSC), TG/DTA, and impedance spectroscopy results. XRD and SEM analyses indicate the amorphous nature of the gel polymer‐salt complex. DSC measurements show a decrease in T_g with the increase in DMF concentrations. The thermal stability of the PVAc : DMF : LiClO₄ gel polymer electrolytes has been found to be in the range of (30–60°C). The dc conductivity of gel polymer electrolytes, obtained from impedance spectra, has been found to vary between 7.6 × 10^?7 and 4.1 × 10^?4 S cm^?1 at 303 K depending on the concentration of DMF (10–20 wt %) in the polymer electrolytes. The temperature dependence of conductivity of the polymer electrolyte complexes appears to obey the VTF behavior. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Synthesis and characterization of proton conducting polymer electrolyte based on poly(N‐vinyl pyrrolidone)

This work aims at developing and characterizing a proton conducting polymer electrolyte based on Poly(N‐vinyl pyrrolidone) (PVP) doped with ammonium bromide (NH₄Br). Proton conducting polymer electrolytes based on PVP doped NH₄Br in different molar ratios have been prepared by solution casting technique using distilled water as solvent. The XRD pattern confirms the dissociation of salt. The FTIR analysis confirms the complex formation between the polymer and the salt. The conductivity analysis shows that the polymer electrolyte with 25 mol % NH₄Br has the highest conductivity equal to 1.06 × 10^?3 S cm^?1 at room temperature. Also it has been observed that the activation energy evaluated from the Arrhenius plot is low (0.50 eV) for 25 mol % NH₄Br doped polymer electrolyte. The influence of salt concentration on dc conductivity and activation energy of the polymer electrolyte has been discussed. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013