Semi-modified okara whey diet increased insulin secretion in diabetic rats fed a basal or high fat diet

Food Science and Biotechnology - Lifestyle and diet preferences are primarily responsible for developing type 2 diabetes. In this study, okara was manufactured into okara whey crackers (OWC) to...     

Role of isophorone diisocyanate in the optimization of adhesion tendency of polyurethane pressure sensitive adhesives

The present work describes the role of accurate selection of diisocyanate on the adhesion strength of polyurethanes (PUs). The concentration of diisocyanate induces the hard segment (HS) in the main architecture of PUs which decides the viscoelastic properties of the polymers. A balanced ratio of viscoelastic properties ultimately determines the adhesion strength. The composition of the polymers consists of a blend of macrodiol of hydroxyl-terminated polybutadiene and polypropylene glycol with different molecular weights. Isophorone diisocyanate (IPDI) is used to develop the urethane linkages by maintaining its contribution from 28 to 67% as HS contents. It determines the adhesion strength of the final product. The adhesion strength is evaluated by texture analyzer and 180° peel test. The probe tack analysis shows maximum adhesion energy of 156.2 J cm⁻² and 180° peel test shows 18.80 N/25 mm peel force. The glass-transition (T _g) values obtained through differential scanning calorimetry are in good agreement with theoretically calculated Flory–Fox temperature. The proportion of the loss tangent to the storage modulus (tan δ/E′) shows the optimum value of 2.80 MPa⁻¹. The ideal concentration of IPDI results to achieve better adhesion properties of PU pressure sensitive adhesives. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47124.     

Influence of cornstarch on thermomechanical behavior of poly(vinyl) chloride bioplastics

The diverse and ubiquitous consumption of polymers urges the necessity to make these materials easily available. However, the excessively used petrochemical-based polymers such as poly(vinyl) chloride (PVC) are nonbiodegradable, which is a motivation to modify it with “green” alternatives. In the present study, PVC (M_w = 48 000 g mol⁻¹⁾ has been incorporated with cornstarch (CS) to synthesize a series of 25 samples of bioplastics in addition to blank polymer samples. The films of five various thicknesses (0.1, 0.2, 0.3, 0.5, and 1.0 mm) have been synthesized using in situ polymerization. Each sample of pure PVC film and bioplastic has been induced with different concentrations of CS in the range of 1–5 wt %. The synthesized samples were subjected to the structural characterization by using Fourier transform infrared. Thermogravimetric analysis has demonstrated the three-step degradation with the improved stability of 250 °C. The 3% concentration of CS has shown the optimum storage modulus (E′) of 1 660 MPa from dynamic mechanical analysis and Tan δ as 0.50. The swelling test performed using water has shown an induction of hydrophilicity in PVC up to 4%. CS-induced bioplastics can be a potential ecofriendly alternative of conventional polymers. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48493.     

Gelation of Plasticized Polyvinyl Chloride Compounds in a Co‐Kneader

The co‐kneader is a proper tool for processing polyvinyl chloride (PVC) compounds. Gelation of PVC is complex because of a narrow processing window. At low temperature, gelation is incomplete and leads to poor mechanical properties, while at high temperature, degradation may occur. The aim of this study is to gain a fundamental understanding of the gelation process of PVC in co‐kneaders. Careful examination of the gelation state of extruded PVC samples was carried out qualitatively by swelling the extruded samples in acetone and quantitatively by differential scanning calorimetry measurements. Gelation in various conditions of temperature and shear was firstly studied in a capillary device that ensures both pre‐shearing and extrusion through a circular die. This provided a reference basis for comparison with gelation state obtained in the co‐kneader. Samples were collected in the co‐kneader by means of opening the barrel. The gelation state was particularly examined in connection with the measured temperature at a fixed position along the screw at which a temperature sensor was positioned. The obtained results showed that the co‐kneader allows fast gelation with a mixing energy value lower than 200 kJ/kg when the temperature is higher than a critical value of 165°C for the studied formulation. J. VINYL ADDIT. TECHNOL., 2019. © 2019 Society of Plastics Engineers J. VINYL ADDIT. TECHNOL., 26:316–324, 2020. © 2019 Society of Plastics Engineers     

Sun drying of cocoa with firebrick thermal storage materials

The thin-layer drying process of N38 cocoa beans using open-sun and a solar drying (SD) system with firebrick heat storage materials (FTSM) has been modeled. The 10 kg capacity force convective SD system was developed and used to carry out the experiments. The choice of the best model was based on a comparison of statistical indicators including determination coefficient (R²), reduced chi-square (χ²), root mean square error (RMSE), sum of square error (SSE), and normalized root mean square error (NRMSE) after fitting the experimental results to 11 common thin layer models in the literature. The results revealed that under open-sun drying and SD processes, the Midilli et al model provided the best drying characteristics of cocoa beans. Therefore, in the experimental context, this model can be assumed to reflect the solar/sun drying behavior of cocoa. The effective diffusivity values for the open-sun and SD of cocoa with FTSMA and FTSMB were 4.25× 10⁻¹¹, 6.64× 10⁻¹¹, and 5. 95 × 10⁻¹¹ m²/s respectively. The predicted pre-exponential factor and activation energy were 5.81 × 10⁻¹¹ m²/s and 22.79 kJ/mol respectively.     

A numerical study of ductile void growth under dynamic loading conditions

A numerical study of void growth at differing global strain rates in the range 149 s^–1–2240 s^–1 and at start temperatures between 173 K and 573 K has been carried out for a material containing a three-dimensional periodic array of equally spaced, initially spherical voids. To take account of the effect of strain rate and temperature on the flow stress under dynamic adiabatic conditions, the well-established Zerilli-Armstrong constitutive relations for pure copper and iron have been employed. An instability criterion based on the maximum mean tensile stress has been used to identify the point at which unstable void growth occurs. For both materials, the strain at instability has been found to be dependent on stress triaxiality and start temperature but only weakly affected by strain-rate     

Thermal,FTIR and UV spectral studies on tellurite glasses doped with cerium oxide

Tellurium oxide-based glasses in the form of 75TeO₂ – 10ZnO – (10-x)Nb₂O₅ – 5Li₂O – xCe₂O₃; where x = 0.5, 1, 1.5, 2, 2.5 mol%, were prepared by using the melt-quenching method. X-Ray Diffraction pattern (XRD) detected the amorphous nature of all the prepared glasses. Physical properties like density (ρ), molar volume $(V_m)$, and oxygen packing density (OPD), have been determined and calculated. Fourier transform infrared spectroscopy (FTIR) studies showed that the glass network contains TeO₄, TeO₃₊₁/TeO₃, ZnO₄, and NbO₆ as structural units. The glass transition temperature (T_g), onset of glass crystallization temperature (T_x), crystallization temperature (T_c), and melting temperature (T_m) have been determined by using differential scanning calorimetry (DSC). The optical band gap (E_opt), the Urbach energy (?E), and the cut off wavelength (λc) were determined through the optical absorption data.     

Prediction-based secured handover authentication for mobile cloud computing

Mobile cloud computing (MCC) is a new technology that brings cloud computing and mobile networks together. It enhances the quality of service delivered to mobile clients, network operators, and cloud providers. Security in MCC technology, particularly authentication during the handover process, is a big challenge. Current vertical handover authentication protocols encounter different problems such as undesirable delays in real-time applications, the man in the middle attack, and replay attack. In this paper, a new authentication protocol for heterogeneous IEEE 802.11/LTE-A mobile cloud networks are proposed. The proposed protocol is mainly based on the view of the 3GPP access network discovery and selection function, which uses the capacities given by the IEEE 802.11 and the 3GPP long term evolution-advanced (LTE-A) standards interconnection. A prediction scheme, with no additional load over the network, or the user is utilized to handle cloud computing issues arising during authentication in the handover process. The proposed handover authentication protocol outperformed existing protocols in terms of key confidentiality, powerful security, and efficiency which was used to reduce bandwidth consumption.

     

Recent advances and perspectives on starch nanocomposites for packaging applications

Starch nanocomposites are popular and abundant materials in packaging sectors. The aim of this work is to review some of the most popular starch nanocomposite systems that have been used nowadays. Due to a wide range of applicable reinforcements, nanocomposite systems are investigated based on nanofiller type such as nanoclays, polysaccharides and carbonaceous nanofillers. Furthermore, the structures of starch and material preparation methods for their nanocomposites are also mentioned in this review. It is clearly presented that mechanical, thermal and barrier properties of plasticised starch can be improved with well-dispersed nanofillers in starch nanocomposites.