Morphology and sintering behaviour of yttria stabilised zirconia (8-YSZ) powders synthesised by spray pyrolysis

This work is focused on the synthesis of nano-crystallised yttria stabilised zirconia (YSZ) powders by the spray pyrolysis method, the aim of the study being a better understanding of the influence of the spray pyrolysis parameters on the morphology of the produced powders. Spray pyrolysed powder consists of polycrystalline particles, which are spherical. Each particle consists of nanometric primary grains. The morphology of these polycrystalline particles was characterised by scanning electron microscopy (SEM), helium pycnometry, thermogravimetric analysis (TGA) and mass spectroscopy (MS), and the results are compared. Thus, particle size, particle size distribution and particle porosity were determined and correlated to the process parameters. Finally, by dilatometric measurements, sintering curves of pellets prepared from different sets of powders were analysed in regard of their morphologies. Two main conclusions could be deduced from these studies. Firstly, the process parameters influence both internal porosity and particle size distribution of the synthesised powders. Secondly, the morphologies of the spray pyrolysed nano-powders lead to particularly high sintering activities.     

The properties of blends of maleic‐anhydride‐grafted polyethylene and thermoplastic starch using hyperbranched polyester polyol as a plasticizer

The first aim of this study was to prepare thermoplastic starch (TPS), namely blends of tapioca starch and hyperbranched polyester polyol and to evaluate the hyperbranched polyester polyol (HBP) as a plasticizing agent for tapioca starch. The second aim was to prepare blends of maleic‐anhydride‐grafted low‐density polyethylene (LDPE‐g‐MA) and TPS, and to evaluate the effect of the mass ratio LDPE‐g‐MA/TPS on the structural, thermal, rheological, morphological, and mechanical properties of the blends. The melting and crystallization temperatures of the LDPE‐g‐MA/TPS blends did not correlate well with the ratio of LDPE‐g‐MA/TPS. The blends exhibited a reduction in the A‐type crystallinity and a pseudoplastic rheological behavior. V‐type crystallinity was not observed for neither TPS nor LDPE‐g‐MA/TPS blends. Scanning electronic microscophy provided an evidence for the presence of starch granules in all the blends and for low interaction degree between LDPE‐g‐MA and TPS. Young's modulus and tensile strength of the LDPE‐g‐MA/TPS blends decreased with the decreasing LDPE‐g‐MA/TPS ratio. POLYM. ENG. SCI., 55:2526–2533, 2015. © 2015 Society of Plastics Engineers     

Engineering a Constrained Peptidic Scaffold towards Potent and Selective Furin Inhibitors

We report the engineering of the monocyclic sunflower trypsin inhibitor (SFTI‐1[1,14]) into a potent furin inhibitor. In a rational approach, we converted the native scaffold of this trypsin‐like serine protease inhibitor into a subtilisin‐like one by substitutions in the canonical and, particularly, in the substrate‐binding loop. Although the substrate sequence for furin is Arg‐X‐Arg/Lys‐Arg↓, the most potent inhibitor had a lysine at position P1. C‐terminally truncated versions demonstrated the strongest activity, thus suggesting a lack of interaction between this motif and the surface of furin. This observation was further supported by molecular modeling. With an inhibition constant of 0.49 nm , the engineered peptide H‐KRCKKSIPPICF‐NH₂ is a promising compound for further development of furin inhibitors aimed at controlling the activity of this protease in vitro and in vivo.     

Acorn (<Emphasis Type="Italic">Quercus</Emphasis> spp.) fruit lipids: Saponifiable and unsaponifiable fractions: A detailed study

The composition of the oils extracted from the acorn fruit of three species of Mediterranean oaks, Quercus ilex L., Q. suber L., and Q. faginea L., was characterized. Both major and minor components, including FA, TG, sterols, methyl sterols, triterpenic and aliphatic alcohols, tocopherols, and hydrocarbons, were identified by standard methods and MS. High-resolution GLC and HPLC were used for quantification. The FA profile, together with the equivalent carbon numbers and TG carbon numbers, was compared with data for other edible vegetable oils. Oil yield, expressed as wet weight, was 5% (w/w). Sterol content was remarkable for the three species (8,563–11,420 mg/kg), with β-sitosterol being the most abundant (80%). Oils were also high in tocopherol, with a wide variation between species (165–456 mg/kg) but with γ-tocopherol predominating in all three oils (90% of the total tocopherol content). Also, high terpenic alcohol contents were found (1527–2984 mg/kg), with dammaradienol and β-amyrin being the most abundant (33–60% of the total alcohol content). Bioactive properties and industrial applications of this underutilized native product are also discussed.     

In situ study of electric-field-induced ferroelectric and antiferromagnetic domain switching in polycrystalline BiFeO3

Antiferromagnetic domain switching induced by ferroelectric polarization switching has previously been observed in situ in both multiferroic BiFeO₃ single crystals and thin films. Despite a number of reports on macroscopic magnetoelectric measurements on polycrystalline BiFeO₃, direct in situ observation of electric-field-induced antiferromagnetic domain switching in this material has not been addressed due to the lack of high-quality samples capable of electrical poling. Here, the electric field control of antiferromagnetic domain texture is identified in polycrystalline BiFeO₃ using in situ neutron diffraction, showing the resultant magnetic domain reorientation induced by an electric field. An antiferromagnetic domain reorientation to a value of 2.2-2.5 multiples of a random distribution (MRD) is found to be induced by an electric field that provides a non-180° ferroelectric-ferroelastic domain texture of 2.2-2.5 MRD along the field direction. The current results show well-controlled coupling of multiferroic domain texturing in single-phase polycrystalline BiFeO₃.     

Imidazolium,Pyridinium and Dimethyl-Ethylbenzyl Ammonium Derived Compounds as Mixed Corrosion Inhibitors in Acidic Medium

Seven cationic surfactants: 1-methyl-3-tetradecyl imidazolium bromide, 1-methyl-3-hexadecyl imidazolium bromide, N,N-tetradecyl pyridinium bromide, N,N-hexadecyl pyridinium bromide, N,N-dimethyl-N-ethylbenzyl ammonium bromide, N,N-dimethyl-N-ethylbenzyl ammonium laurate and N,N-dimethyl-N-ethylbenzyl ammonium acetate, were investigated at different doses (10, 25, 50, 100, and 200 ppm) as corrosion inhibitors for steel grade API 5L X52 in hydrochloric acid 2 M using a weight loss technique, impedance and polarization resistance methods. The corrosion inhibition of steel grade API 5L X52 of the cationic surfactants was attributed to their molecular structure (heterocyclic ring, hydrophobic chain length and counterion) that enhances adsorption onto steel surface. The best protective efficiency of the film was higher than 90% (N,N-Dimethyl-N-ethylbenzyl ammonium acetate). It is important to know how organic inhibitor films grown on the metallic surface in order to achieve superior corrosion inhibition, hence experimental findings were described by Langmuir adsorption isotherm. The Electrochemical Impedance Spectroscopy spectrums were fitted by means of the Voigt model.     

Interpolation,extrapolation, and truncation in computations of CIE tristimulus values

This article addresses some general practices for the computation of CIE tristimulus values (TSVs), including different methods used for the interpolation, extrapolation, and truncation of data in the visible wavelength range. In each case, a quantitative analysis is presented on the basis of a dataset with 2365 spectral reflectances covering a wide color gamut, assuming six CIE illuminants and the two CIE standard colorimetric observers. For interpolation, it is found that among five tested methods, the (cubic) spline method is the best one when the spectral reflectance factors are uniformly sampled over the visible wavelength range. For extrapolation, it is found that the second‐order extrapolation method gives better results than the use of nearest available data points or linear extrapolation methods. With respect to truncation, considering five different usual truncated ranges, it is found that the range from 360 to 780 nm provides more accurate results than the range from 380 to 780 nm currently recommended by CIE for nonfluorescent samples, and the use of the truncated range from 400 to 700 nm in place of the CIE‐recommended range of 360 to 830 nm leads to TSVs with considerably high color differences of up to 0.9 CIELAB units. © 2016 Wiley Periodicals, Inc. Col Res Appl, 42, 10–18, 2017     

Color harmony in two‐piece garments

Using a categorical scale of 10 U, we have assessed color harmony in two‐piece garments (jackets‐trousers) considering a vicenarian and a quinquagenarian style. The experiment was performed by a panel of 59 Chinese observers (26 males and 33 females) with normal color vision and ages ranging 20–78 years, considering 300 color combinations for each of the two styles. For a given color combination, comparing results in the vicenarian/quinquagenarian styles for female/male observers, and observers below/above 45 years old, we found generally higher harmony scores for the vicenarian style, male observers, and observers older than 45 years. We found statistically significant differences (Welch two‐sample t test, P < 0.001) between color‐harmony results for the vicenarian and quinquagenarian styles, as well as considering the scores reported both by male/female observers and by observers below/above 45 years old. We propose a very simple lineal model fitting our current results with an average root mean square error (RMSE) of 0.70 U in our 10‐unit scale, which is below the one achieved by other complex models previously proposed, and also below the inter‐ and intra‐observer variability in our experiment. From our total experimental results, each of the five traditional color‐harmony principles (complementary hues and equal lightness, chroma, tone, and hue) was found to be valid at a low percentage (53–58% of the cases). © 2016 Wiley Periodicals, Inc. Col Res Appl, 42, 498–511, 2017     

Comprehensive color solutions: CAM16, CAT16, and CAM16‐UCS

The CIECAM02 color‐appearance model enjoys popularity in scientific research and industrial applications since it was recommended by the CIE in 2002. However, it has been found that computational failures can occur in certain cases such as during the image processing of cross‐media color reproduction applications. Some proposals have been developed to repair the CIECAM02 model. However, all the proposals developed have the same structure as the original CIECAM02 model and solve the problems concerned at the expense of losing accuracy of predicted visual data compared with the original model. In this article, the structure of the CIECAM02 model is changed and the color and luminance adaptations to the illuminant are completed in the same space rather than in two different spaces, as in the original CIECAM02 model. It has been found that the new model (named CAM16) not only overcomes the previous problems, but also the performance in predicting the visual results is as good as if not better than that of the original CIECAM02 model. Furthermore the new CAM16 model is simpler than the original CIECAM02 model. In addition, if considering only chromatic adaptation, a new transformation, CAT16, is proposed to replace the previous CAT02 transformation. Finally, the new CAM16‐UCS uniform color space is proposed to replace the previous CAM02‐UCS space. A new complete solution for color‐appearance prediction and color‐difference evaluation can now be offered.     

An approach to assess the synergistic effect of natural antioxidants on the performance of the polypropylene stabilizing systems

A study on the efficiency of natural antioxidants from agri‐food industry wastes as long‐term antioxidants for polypropylene (PP) is reported. Special attention is paid to the usage of vegetal wastes as a source of natural antioxidants such as alternatives to synthetic long‐term antioxidants. The potential of the lignin‐derived fractions generated during autoydrolysis processing of lignocellulosic agricultural, forestal, and food wastes was assessed. The measurements of oxidation induction time were used for obtaining information on long‐term antioxidant effectiveness, showing the protective effect of natural extracts. The protective effect was improved in combinations of natural extracts with 0.1% and 0.2% of Irgafos 168 (short‐term antioxidant) besides a synergistic effect was exhibited when 0.4% of Irgafos 168 is added. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012