Effects of area,year and climatic factors on Barbera wine characteristics studied by the combination of 1H-NMR metabolomics and chemometrics

Barbera is one of the most common red grape in Italy, found in almost every region of the country. The widespread market of the corresponding wine deserves studies on its traceability and authenticity. To this end, the ¹H-NMR database of several wine metabolites was built using spectra recorded in a wine-like matrix containing ethanol and tartaric acid with pH precisely adjusted. The combination of ¹H-NMR metabolomics study and chemometrics (multivariate data analysis) is able to discriminate between samples of such a wine produced in three different areas of Piedmont. The influence of climatic factors on the wine characteristics has also been studied.     

Sensory, physical, chemical and microbiological changes in European sea bass (Dicentrarchus labrax) fillets packed under modified atmosphere/air or prepared from whole fish stored in ice

Quality changes and shelf‐life in European sea bass fillets packed under 40% CO₂: 60% N₂ (MAP) and air (AIR) or prepared from the whole ungutted fish stored in ice (ROUND) were compared. Raw and cooked sensory scores, pH, colour, expressible water, malonaldehyde, total viable count, Pseudomonas spp., H₂S‐producing bacteria, Lactobacillus spp., Streptococcus spp., Staphylococcus spp., coliforms and proteolytic counts, were determined until AIR and MAP raw fillet spoilage. Raw ROUND fillets had the best quality and shelf‐life (10 vs. 8 vs. 7 days after slaughtering in ROUND, MAP and AIR, respectively), while the MAP fillets had better sensorial scores, lower pH values and better microbiological counts, but greater lightness values than the corresponding AIR fillets. MAP fillets also had the highest malonaldehyde levels. The higher correlation between Streptococcus spp. and odour scores (r = ?0.971, P < 0.01) compared to the other species could suggest that it is a specific spoilage organism in the MAP condition used.     

Effects of metacognitive strategy training within a cooperative group learning context on computer achievement and anxiety: An aptitude–treatment interaction study.

Two aptitude–treatment interaction studies examined the comparative effects of metacognitive strategy training in self-questioning within a cooperative group learning context and a traditional direct instruction approach, on the acquisition of computing competencies, learning anxiety, and positive cognitions. When prior competence in using computers is controlled, students' initial aptitudes interact significantly with teaching method. Cooperative groups scored significantly better on achievement tests, self-concept, and sense of control-mastery than did the direct instruction groups. Paradoxically, for the initially high-anxious learners, some aspects of computing anxiety remained high in the cooperative group relative to the direct instruction group, suggesting that anxiety may facilitate learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Formation of pores and amorphous-nanocrystalline phases in porous TiNi alloys made by self-propagating high-temperature synthesis (SHS)

The objective of this study was to examine the mechanism how the surface of porous TiNi compounds produced by SHS method evolves. The prepared samples were investigated using light-microscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy dispersive x-ray spectroscopy (EDS). The results indicated that the surface of all pores is represented by a granular stratum due to dendrite liquation by peritectic crystallization mechanism. The voids of 2–15?μm in size are formed owing to a capillary spreading of the liquid. Reaction gases with dissociated carbon, nitrogen, and oxygen are responsible for heat-and-mass transfer through the forming pores. High pressure-temperature effect of reaction gases on the melt causes the forming voids to coalesce, as well as transfers the peritectic liquid (PL) throughout the open pores catalyzing a distinctive spitted topography. It is through the chemisorption of gasiform nonmetallics by the pore surface melt, where these impurities are chemically bound, that it was formed a massive corrosion-resistant amorphous-nanocrystalline stratified shell deduced as an intermetallic oxycarbonitride layer.     

A mixed numerical–analytical stable pseudo‐inversion method aimed at attaining an almost exact tracking

This paper considers the problem of computing the input u(t) of an internally asymptotically stable, possibly non‐minimum phase, linear, continuous time system Σ yielding a very accurate tracking of a pre‐specified desired output trajectory . The main purpose of the new approach proposed here is to alleviate some limitations that inherent the classical methods developed in the framework of the preview‐based stable inversion, which represents an important reference context for this class of control problems. In particular, the new method allows one to deal with arbitrary and possibly uncertain initial conditions and does not require a pre‐actuation. The desired output to be exactly tracked in steady state is here assumed to belong to the set of polynomials, exponential, and sinusoidal time functions. The desired transient response is specified to obtain a fast and smooth transition toward the steady‐state trajectory , without under and/or overshoot in the case of a set point reset. The transient control input u_t(t) is a priori assumed to be given by a piecewise polynomial function. Once has been specified, this allows the computation of the unknown u_t(t) as the approximate least squares solution of the Fredholm's integral equation corresponding to the explicit formula of the output forced response. The steady‐state input u_s(t) is analytically computed exploiting the steady‐state output response expressions for inputs belonging to the same set of . Copyright © 2013 John Wiley & Sons, Ltd.     

Parallel algebraic multilevel Schwarz preconditioners for a class of elliptic PDE systems

Algebraic multilevel preconditioners for algebraic problems arising from the discretization of a class of systems of coupled elliptic partial differential equations (PDEs) are presented. These preconditioners are based on modifications of Schwarz methods and of the smoothed aggregation technique, where the coarsening strategy and the restriction and prolongation operators are defined using a point-based approach with a primary matrix corresponding to a single PDE. The preconditioners are implemented in a parallel computing framework and are tested on two representative PDE systems. The results of the numerical experiments show the effectiveness and the scalability of the proposed methods. A convergence theory for the twolevel case is presented.     

Antonelli’s Dome for San Gaudenzio: Geometry and Statics

In this brief note the authors describe the studies undertaken to date regarding the dome of the Basilica of San Gaudenzio in Novara designed by Alessandro Antonelli, with particular emphasis on the geometry and statics of the external dome. Following a brief summary of the events and vicissitudes attendant on the construction of the dome, the structure will be examined from the point of view of the geometry, the construction techniques, and the materials used, in order to clarify the static behaviour and the stability of the whole set of structural and constructive elements of which the dome is composed. These studies have allowed us to obtain the necessary information for evaluating the complex and ambitious structural achievement of a significant element of Antonelli’s basilica.     

Development of convection in binary mixture with soret effect

The future Space experiment IVIDIL is planned to study the influence of vibration stimuli on the measurements of diffusion and thermodiffusion coefficients. A binary mixture of water and isopropanol is chosen as a working liquid. The principle of the Space experiment and ground based research are outlined. In addition preparatory experiments might be performed during parabolic flights. Results of 3D numerical simulations of thermal vibrational convection in binary mixture at the conditions of the parabolic flight are presented. Heat and mass transport arising in the system with increasing of vibration actions is discussed.     

Oxidation Processes for Alloys in the Ni – Zr System. Part 2. Phase Composition of Scale Formed on Ni7Zr2

We have used x-ray and metallographic layer-by-layer phase analysis to study the structure and composition of scale formed on the alloy Ni₇Zr₂ during its oxidation in air over a period of 1 h and 10 h in the temperature range 500-1200°C. In the scale we find NiO, the cubic and monoclinic modifications of ZrO₂, and also Ni and Ni₅Zr. The phase components are nonuniformly distributed over the thickness of the scale. The outer scale consists of the oxides NiO and ZrO₂, while the composition of the inner scale includes Ni and Ni₅Zr in addition to monoclinic ZrO₂. Cubic ZrO₂ is formed on the surface of the specimen in the initial stages of its oxidation at 500-700°C. For T ≥ 900°C, on the surface of the scale we find both modifications of ZrO₂, while the nickel phase is itself a solid solution Ni(Zr). We note that the mechanisms for the formation of low-temperature (T ≤ 800°C) and high-temperature (T ≥ 900°C) scales are different. It is hypothesized that these differences are determined mainly by the fact that at high temperatures, diffusion of zirconium ions toward the outer boundary of the scale is superimposed on diffusion of oxygen toward the scale – alloy boundary.     

A DNA origami plasmonic sensor with environment-independent read-out

Nano Research - DNA origami is a promising technology for its reproducibility, flexibility, scalability and biocompatibility. Among the several potential applications, DNA origami has been proposed...