Evaluation of the peptide profile with a view to authenticating buffalo mozzarella cheese

Electrophoretic and chromatographic techniques were used to determine water‐soluble peptide profiles aiming to identify the adulteration of buffalo milk mozzarella cheese by the addition of cow's milk. Thus, cheeses were produced with contents of cow's milk varying from 0% to 100%, and the peptides extracted after production and after 20 days of refrigeration. Polyacrylamide gel electrophoresis under denaturing conditions in the presence of sodium dodecyl sulphate (SDS‐PAGE) identified a potential peptide marker of exclusively bovine origin with a size of about 21 kDa for the addition of cow's milk above 30%. Reverse‐phase high‐performance liquid chromatography (RP‐HPLC) indicated the existence of two potential peptides present in higher concentrations in buffalo milk and one exclusive for cow's milk, the latter making it possible to estimate the addition of cow's milk to buffalo milk. Six commercial brands of buffalo mozzarella cheese were evaluated, and indications of adulteration found in four of them.     

Steel Microstructure Effect on Mechanical Properties and Corrosion Behavior of High Strength Low Carbon Steel

Different thermomechanical treatments were applied to a high strength low carbon steel with a novel chemical composition. As a result, three different microstructures were produced with dissimilar mechanical and corrosion properties. Subsequently, a tempering heat treatment was applied to redistribute the phases in the steel. Microstructure A with 56 pct martensite and 32 pct bainite presented high strength but medium ductility; microstructure C with 95 pct ferrite and 3 pct martensite/austenite resulted in low strength and high ductility, and finally microstructure B with 98 pct bainite and 2 pct martensite/austenite resulted in high strength and ductility. Alternatively the corrosion behavior obtained by polarization curves was characterized in 0.1 M H₂SO₄, 3 M H₂SO₄, 3.5 wt pct NaCl, and NS4 solutions resulting in similar magnitudes, while the corrosion behavior acquired by electrochemical impedance spectroscopy had slightly differences in 3 M H₂SO₄.     

Nucleation and Crystallization of New Glasses from Fly Ash Originating from Thermal Power Plants

The nucleation and crystallization kinetics of new glasses obtained by melting mixtures of a Spanish carbon fly ash with glass cullet and dolomite slag at 1500°C has been evaluated by a calculation method. These glasses, whose microstructure was examined by TEM carbon replica, were susceptible to controlled crystallization in the 800°–1100°C range. The resulting glass-ceramics developed acicular and branched wollastonite crystals or a network of dendritic pyroxene mixed with anorthite feldspar (SEM and EDX analysis). The time–temperature–transformation curves (processing of the XRD data) showed the crystallization kinetics and the critical cooling rate to be in the 12°–42°C/min range.     

Harmonic modelling of PV systems for probabilistic harmonic load flow studies

Probabilistic harmonic load flow (HLF) is currently enjoying renewed popularity. This is not surprising since in the near future, thousands of photovoltaic (PV) systems will be integrated into distribution systems. However, as yet, there is no model capable of explaining PV harmonic current behaviour in probabilistic HLF studies. To fill this gap, the harmonic modelling of PV systems proposed in this paper has three key points. First, it provides an effective model of the relationship between PV harmonic current emission and background harmonic voltages. Second, it statistically characterises PV harmonic currents (relative magnitude and phase angle) at different fundamental‐frequency current output intervals using historical time‐series data. In this statistical characterisation, the first fifth moments of each PV harmonic current are used to accurately approximate the raw probability density function (PDF) by means of the Legendre series. Finally, the third key point of this harmonic modelling is a method capable of determining the distribution functions of PV harmonic currents (absolute magnitude and phase angle), based on the statistical characterisation and a fundamental‐frequency probabilistic PV model. The numerical results obtained confirm the effectiveness of this PV model. Copyright © 2014 John Wiley & Sons, Ltd.     

Troubleshooting in geoelectrical prospecting using real‐coded genetic algorithm with chromosomal extrapolation

This work presents a genetic operator developed from mathematical methods of curve extrapolation applied in solving problems in geoelectrical prospection. This operator will assist the production of fitter individuals in the population of a genetic algorithm in which inherent patterns of the best individuals of each generation are recognized. The proposed operator in conjunction with a real‐coded genetic algorithm is compared to five alternative optimization techniques known and used in the application to problems in geoelectrical prospection. Copyright © 2014 John Wiley & Sons, Ltd.     

A Wildland–Urban Interface Typology for Forest Fire Risk Management in Mediterranean Areas

The transitional areas that lie between wildlands and urbanized spaces, generally defined as wildland–urban interfaces (WUI), represent an increasing risk factor in Mediterranean areas; these define a new scenario in forest fire fighting and prevention. We have developed a methodological approach in order to assess the hazard and vulnerability of WUI which is based on landscape analysis, on the use of Geographic Information Systems (GIS) techniques and remote sensing. Unlike traditional approaches which are based on local scale characterization of WUI, we propose a progressive multi-scale approach. In order to reach an operative classification of the WUI the methodology was developed in three stages: a regional urban development model, a landscape character assessment and finally, a WUI typology. The last WUI typology has been based on the identification of different urban morphologies and their context within the type of landscape in which they occur.     

Optimization of osmotic dehydration of yacon slices

Osmotic dehydration assisted by ultrasound (ODAU) at low temperatures reduces water activity (a_w) and maintains nutrients. The influence of solution concentration (SC; 20 to 60° Brix, xylitol and sorbitol) and ultrasound application time (t_us, 0 to 40 min) in ODAU of yacon was studied with the aid of a response surface method. The optimum condition with respect to mass transfer parameters, a_w, and fructan retention was SC of 60° Brix for both solutions and t_us of 2.67 min for xylitol samples and 0 min for sorbitol samples. The application of ultrasound improved dehydration but resulted in depolymerization of fructans.