Novel Self‐Reinforced Films Based on Poly (3‐Hydroxybutyrate‐Co‐3‐Hydroxyvalerate) (PHBV) and PHBV Microparticles

Biodegradable self‐reinforced films of poly (3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) (PHBV) and PHBV microparticles were prepared through the solvent casting method (srPHBV). Differential scanning calorimetry (DSC), wide angle X‐ray scattering (WAXS) and polarized optical microscopy results confirmed the nucleating effect of PHBV microparticles. WAXS proved that diffractograms of PHBV and srPHBV‐6 films at room temperature contain the main characteristic diffraction peaks of an orthorhombic α‐type crystalline structure. Small angle X‐ray scattering (SAXS) showed a similar decrement rate of long spacing in PHBV and srPHBV films. SAXS/WAXS data revealed that when the amount of filler was increased, lamellae thickness grew. Transmission electron microscopy images illustrated well filler dispersion in the srPHBV films. Scanning electron microscopy results exhibited a significant reduction in porosity for srPHBV films once the PHBV microparticles were added. Atomic force microscopy analysis showed higher surface roughness after filler incorporation. Samples of srPHBV films showed higher barrier properties against water vapor, oxygen, and carbon dioxide. Combined properties of srPHBV films revealed the possibility of being suitable candidates for food packaging applications. POLYM. ENG. SCI., 59:E120–E128, 2019. © 2018 Society of Plastics Engineers     

Color evolution during a coating process of pharmaceutical tablet cores by random spraying

Placebo white tablet cores (lactose anhydrous [47.6%], corn starch [23.8%], microcrystalline cellulose [19.1%], polyvinylpyrrolidone [7.9%], magnesium stearate [0.8%], and talcum powder [0.8%]) were coated with a colorant (hydroxypropyl methylcellulose [8% w/v], titanium dioxide [0.2% w/v], FD&C yellow No. 6 with aluminum lacquer [0.8% w/v], polyethylene glycol 4000 [0.4% w/v], and purified water [q.s.p. 100 mL]) using a random spraying method during 130 minutes. During the coating process, batches of 21 samples were extracted every 10 minutes and measured with a DigiEye imaging system. The initial cores showed very similar and uniform colors (Mean Color Difference from the Mean [MCDM] of 0.8 CIELAB units), but partially coated tablets showed lower uniformity (MCDM below 2.0 CIELAB units). There was a high color variability (MCDM about 4.0 CIELAB units) among tablets of the same batch in the period between 10 and 30 minutes, which decreased as the coating process progressed, until achieving a final acceptable value (MCDM below 2.0 CIELAB units). During the coating process, L^* decreased, C^*_ab strongly increased, and h _ab remained nearly constant (disregarding results at 0 and 10 minutes). CIELAB and CIEDE2000 color differences (mainly chroma differences) with respect to the initial color of the tablets were modeled as a function of time by exponential functions with three coefficients. The color change in the interval from 90 to 130 minutes (4.3 CIELAB units, or 2.6 CIEDE2000 units), may be considered negligible bearing in mind the color variability in the batches of 21 samples and typical values of visual color thresholds.     

Scalable and flexible wireless distributed architecture for intelligent video surveillance systems

Multimedia Tools and Applications - This paper presents a novel distributed intelligent video surveillance architecture based on Wireless Multimedia Sensor Networks (WMSNs). This architecture is...     

Modeling (2-2) piezocomposites partially sliced in the polymer phase

Different attempts have been suggested to improve the efficiency of piezocomposites. Here, a new design which consists of subdicing the passive part of (2-2) composites is presented. A theoretical model based on the series-parallel connections of elastic sections has been developed. It is shown that the cuts increase the electromechanical coupling coefficient. The model shows that, at high ceramic percent, the resonance frequency decreases when cutting the composite. At low ceramic percent the behavior is the opposite. Samples of (2-2) piezocomposites with low, medium, and high ceramic percent have been made, comparing predictions with experimental results. The agreement is satisfactory. With this composite structure, another design parameter is added to the search for better piezocomposite performance.     

Set-based extended aggregation functions

Inspired by the Zadeh approach to fuzzy connectives in fuzzy set theory and by some applications, we introduce and study set-based extended functions, and in particular, set-based extended aggregation functions. These functions reflect neither reordering nor repetition of input values, and, linking different arities, they introduce serious constraints for extended functions. A complete characterization of set-based extended (aggregation) functions is given, and some constructions of such functions are also proposed, including several examples.     

A novel ordered weighted averaging weight determination based on ordinal dispersion

One of the most common techniques to find the adequate weights in ordered weighted averaging (OWA) operators is based on the orness concept, where the weights are determined by maximizing the entropy (variation) for a fixed orness value. But such an entropy represents a dispersion measure for nominal variables, while weights in an OWA operator are essentially ordinal rather than nominal. Hence, in this paper, we propose a novel way to determine OWA weights based upon ordinal dispersion measures instead of an standard entropy measure. From this approach, we find an explicit formula for the weights, and we illustrate differences by means some multicriteria decision-making examples.     

Effects of gibberellic acid (GA3) on strawberry PAL (phenylalanine ammonia-lyase) and TAL (tyrosine ammonia-lyase) enzyme activities

Gibberellic acid (GA₃) treatments (30 and 60 μg litre⁻¹) were applied to young plants (Fragaria ananassa cv Chandler). Fruits were harvested at various developmental stages (14, 21, 28 and 35 days from fruit set). Weight and size, phenolic compounds (total polyphenols and anthocyanins) and enzyme activities, phenylalanine ammonia-lyase (PAL) and tyrosine ammonia-lyase (TAL) were determined. Our aim was to obtain detailed information about PAL and TAL activities related to the strawberry colour during development and ripening processes and to determine the effects of exogenous treatments of GA₃ on PAL and TAL activities. Exogenous treatments of GA₃ improve weight, size and colour of strawberry fruits, and affect PAL and TAL activities. We found that the anthocyanin content and PAL activity are enhanced by the exogenous treatment of GA₃ in the range of 30 μg litre⁻¹. However, with the higher GA₃ treatment, only the anthocyanin content is affected in that way. These findings suggest that gibberellic acid effect on PAL, TAL and ultimately anthocyanin enhancement is dosage related and saturation of the response occurs at 30 μg litre⁻¹. © 1998 SCI.     

Physico-chemical and film-forming properties of bovine-hide and tuna-skin gelatin: A comparative study

A bovine-hide gelatin and a tuna-skin gelatin, both characterized on the basis of their amino acid composition and molecular weight distribution, were used to prepare edible films by casting with glycerol and sorbitol added as plasticizers. The molecular weight distribution of the tuna-skin gelatin exhibited appreciably higher quantities of β-components (covalently linked α-chain dimers), whereas bovine-hide gelatin showed a certain degradation of α₁-chains being indicative of a greater proteolysis. Intrinsic differences in the gelatin attributes affected in diverse manner some of the physical properties of the films. Thus, water vapour permeability was higher in the bovine-hide gelatin film, whereas deformability was considerably higher (10 times higher) in the tuna-skin gelatin film. In contrast, breaking force and water solubility were basically unaffected by gelatin origin. Analysis of the thermal properties revealed both films to be wholly amorphous with similar glass transition temperature values thanks to the plasticizing effects of the glycerol and sorbitol and the low moisture contents.