Sunflower Protein Concentrates and Isolates Prepared from Oil Cakes Have High Water Solubility and Antioxidant Capacity

Increasing the applications of industrial by-products is of great interest. Therefore, in the present study, sunflower oil cake from a local oil manufacturing company was used to obtain soluble protein concentrates and isolates with different content of phenolic compounds. All the extraction procedures evaluated resulted in concentrates and isolates with water solubility higher than 75% but with different chemical composition, color and physicochemical properties (i.e. surface hydrophobicity, thermal stability, and polypeptide composition). Since no extraction process led to a complete extraction of phenolic compounds, all the products exhibited antioxidant activity, which depended on the concentration of such compounds. Phenolic compounds give a dark color to sunflower protein concentrates and isolates; nevertheless their final color tone was more dependent on the conditions used in the preparation process than on the amount of phenolic compounds in the product. The results demonstrate the value of sunflower industrial oil cake as a source of proteins with high water solubility, good physicochemical properties and antioxidant activity.     

Electrodeposition of pristine and composite poly(3,4-ethylenedioxythiophene) layers studied by electro-acoustic impedance measurements

Composite layers of poly(3,4-ethylenedioxythiophene) and diamond nanoparticles were prepared by an electrocodeposition procedure from an electrolyte containing the monomer 3,4-ethylenedioxythiophene and a suspension of diamond nanoparticles in acetonitrile/water mixtures. For the in situ monitoring of the deposition process we used piezoelectric quartz crystals with gold electrodes as substrates (electrochemical quartz crystal microbalance, EQCM). The inclusion of the diamond particles increases the stiffness of the layers. This effect can be directly quantified via the electroacoustic impedance of the quartz crystal. We use a mean field model for the interpretation of our EQCM data which yields the complex shear modulus of the composite layers. The volume fraction of diamond (as determined by ex situ XPS) enters as a parameter in the evaluation procedure. Finally, we could estimate the solvent content of the composite layers and the shear moduli of the pure dry PEDOT matrix.     

Development of a method to determine Ni and Cd in biodiesel by graphite furnace atomic absorption spectrometry

This paper proposes a low cost, simple, fast method for determining Ni and Cd in biodiesel samples by graphite furnace atomic absorption spectrometry (GFAAS). The method was evaluated in biodiesel from different sources. Tungsten was used as a permanent modifier and the samples were prepared in the form of microemulsions, by mixing about 0.5 g of biodiesel with 5 g of surfactant (Triton X-100) in volumetric flasks and completing the volume with HNO₃ 1% (v/v). The detection limits obtained for Ni and Cd in microemulsions were ≤0.9 and 0.1 μg L⁻¹, respectively. The relative standard deviation (% R.S.D., n = 12) was ≤8.20% for Ni (washed animal fat sample) and ≤4.71% for Cd (sunflower oil sample). Accuracy was checked based on addition and recovery experiments, which yielded recovery rates varying from 93% to 108% for Ni and from 98% to 116% for Cd. Sample preparation is rapid and easy, and the use of an inorganic standard for calibration makes this sample preparation procedure suitable for routine applications.     

Hollow cathode synthesis of crystalline CN films

We describe a novel carbon hollow-cathode RF plasma reactor which has been used to prepare deposits of carbon nitride. Results of the characterization of the deposits by Fourier transform infrared (FTIR) microscopy, Raman microscopy, transmission electron microscopy (TEM), energy-dispersive X-ray analysis and X-ray diffraction are presented. The variation of the properties of the deposits as a function of the deposition conditions is discussed. The inclusion of small quantities of methane in the gas mixture was found to enhance the formation of the CN deposit, but for conditions of maximum enhancement C–H and N–H groups were observed in the deposit. Elemental analysis of the deposit showed that the nitrogen content was 57 at.%. A crystalline deposit was obtainable at low substrate temperatures, and the crystals were seen to grow preferentially on defects on the substrate surface.     

Surface properties,thermal, and mechanical characteristics of poly(vinyl alcohol)–starch‐bacterial cellulose composite films

Nanocomposite films for food packaging applications were developed using bacterial cellulose (BC) nanofibers in different amount in a poly(vinyl alcohol)/starch (PVA/St) matrix. In search of a better method to reduce the harmful ingredients in food packaging, the cellulose nanofibers were obtained by the mechanical defibrillation of BC pellicles thus avoiding the addition of chemicals in the final packaging material. Improved mechanical performances were obtained starting from just 1% BC nanofibers in PVA/St. Atomic force microscopy images showed a uniform dispersion of BC nanofibers on the surface of nanocomposites. A twofold increase of both tensile strength and modulus was obtained for 2 wt % BC in the composite. BC nanofibers have greatly improved the barrier properties of PVA/St matrix, a twofold increase of water vapor permeability being obtained for only 2 wt % BC nanofibers in the composite film. PVA/St/2BC was proposed as a high potential material for food packaging applications. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45800.     

An interpretation of neural networks as inference engines with application to transformer failure diagnosis

An artificial neural network concept has been developed for transformer fault diagnosis using dissolved gas-in-oil analysis (DGA). A new methodology for mapping the neural network into a rule-based inference system is described. This mapping makes explicit the knowledge implicitly captured by the neural network during the learning stage, by transforming it into a Fuzzy Inference System. Some studies are reported, illustrating the good results obtained.     

Novel synthesis of phosphorus containing polymers under inverse phase transfer catalysis

A novel synthesis of polyphosphates by inverse phase transfer catalysis (IPTC) was investigated. The reaction of methylphosphoric dichloride (MPD) and sodium salt of bisphenol A (BA) in two-phase H₂O/CH₂Cl₂ medium under IPTC is presented and the results are evaluated by the yield and inherent viscosity values. The biphasic medium does not require rigorous stirring. The polyphosphate was characterized by IR, ¹H NMR, ³¹P NMR, inherent viscosity, thermal analysis, and molar mass. Pyridine (Py), pyridine-oxide (PNO) and 4-dimethylamino-pyridine (DMAP) were used as the inverse phase transfer catalysts. DMAP was found to be the best catalyst.     

Effect of the underlayer on the microstructure and surface evolution in Al-0.5wt.%Cu polycrystalline thin films

The effects of the Ti underlayer on the evolution of grain morphology, crystallographic texture, and surface roughness of Al-0.5wt.%Cu thin films during sputter deposition have been characterized. In comparison to SiO₂ substrates, Ti underlayers reduce the AlCu thickness at which film continuity is reached, reduce the AlCu columnar grain size, and allow exact Al (111) fiber texture development. The AlCu films on both Ti and SiO₂ are primarily randomly oriented at early stages of deposition. A near-(111) Al fiber texture in AlCu/SiO₂ films initiates during the preferential growth of ≈5° offset islands prior to film continuity, seeding the near Al (111) texture as film continuity is reached. The exact Al (111) fiber orientation in AlCu/Ti films develops after film continuity. The near-(111) and exact (111) fiber textures strengthen with further deposition due to combined normal and abnormal grain growth. Film coalescence and grain growth lead to a significant smoothing effect during the early stages of deposition.     

Delayed involution of the mammary epithelium in BALB/c-p53null mice

In mammals, weaning of neonates and subsequent milk stasis initiates removal of the secretory epithelium of the mammary gland by apoptosis. The p53 tumor suppressor gene is induced rapidly following weaning of neonates, but its role in the process of involution has not been defined. Therefore, experiments were performed to identify the cell types in which the p53 gene is expressed during involution and determine the consequences of its absence in BALB/c-p53null mice. Both p53 mRNA and protein were detected in the mammary epithelium within 48 h following weaning and resulted in an eightfold increase in levels of p21WAF1 mRNA. Induction of p21WAF1 mRNA was absent in BALB/c-p53null mice, and therefore, was shown to be p53-dependent. The BALB/c-p53null mice exhibited delayed involution of the mammary epithelium, as measured by 60% greater epithelial area compared to BALB/c-p53(wt) mice through 5 days post-weaning. The delay was transient with no differences being apparent at 7 days post-weaning. Expression of the stromal protease stromelysin-1 was unaffected by the absence of p53 suggesting that stromal responses were intact. These data demonstrate that p53 participates in the first stage of involution initiated by the epithelium itself, but does not affect the second phase during which stromal proteases are induced.