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71.
Sandra Pati Domenico La Notte Maria Lisa Clodoveo Giuseppe Cicco Marco Esti 《European Food Research and Technology》2014,239(4):595-602
When the vintage is poor, different must concentration techniques are used for overcoming grape compositional deficiency, such as evaporative or freeze concentration, and membrane processes. The membrane filtration works at low temperature, preserving must components from degradation. The aim of the present work was to tailor reverse osmosis and nanofiltration technologies applied to grape juice testing several membranes for different grape varieties from southern Italy. The main oenological parameters, including sugar content, acidity, pH, color and total phenol content, were evaluated in comparison with the addition of rectified concentrated must. Quality characteristics of all musts showed to be improved by means of membrane processes, which could be successfully implemented in the cases of premature harvest carried out for obtaining wines with enhanced acidity. 相似文献
72.
Emilio Gambacorta Amalia Simonetti Nunzia Garrisi Immacolata Intaglietta Annamaria Perna 《International Journal of Food Science & Technology》2014,49(10):2260-2268
The geographical origin greatly influences the qualitative and nutraceutical characteristics of honey. In this study, a total of twenty‐four sulla honeys from eight different geographical areas of Southern Italy have been examined for total phenolic content (Folin–Ciocalteu method), antioxidant activity (FRAP and DPPH assays), colour intensity (ABS450), and identification and quantification of phenolic acids (RP‐HPLC/UV‐VIS method). The total phenolic content ranged from 47.9 (Potentino honeys) to 248.3 mg GAE per kg honey (Penisola Sorrentina honeys). The antioxidant activity ranged from 47.06% (Basso Pollino honeys) to 88.25% (Penisola Sorrentina honeys), and from 98.26 μM Fe (II) (Potentino honeys) to 786.53 μm Fe (II) (Tarantino honeys) for DPPH and FRAP assays, respectively. Major phenolic acids identified in analysed samples were gallic, caffeic and ferulic acids. Correlations between the parameters analysed were statistically significant (P < 0.05). The results of the study showed that the parameters studied are greatly affected by the peculiarities of their production area. 相似文献
73.
Agnieszka Witkowska Sonia Dsoke Emiliano Principi Roberto Marassi Andrea Di Cicco Valerio Rossi Albertini 《Journal of power sources》2008
The paper presents a preliminary structural investigation of the 20% Pt–Co (1:1) alloy on Vulcan XC-72 catalyst using X-ray absorption spectroscopy (XAS), transmission electron microscopy (TEM) and X-ray diffraction (XRD). XAS results have been obtained ex situ and in situ using a specially optimized for XAS measurement fuel cell (down to 6 keV). The results are compared with those obtained for pure Pt catalyst on the same carbon support under the same working conditions. 相似文献
74.
Robust stability analysis of Smith predictor-based congestion control algorithms for computer networks 总被引:1,自引:0,他引:1
Congestion control is a fundamental building block in packet switching networks such as the Internet due to the fact that communication resources are shared. It has been shown that the plant dynamics is essentially made up of an integrator plus time delay and that a proportional controller plus a Smith predictor defines a simple and effective controller. It has also been shown that the TCP congestion control can be modelled using a Smith predictor plus a proportional controller. Due to the importance of this control structure in the field of data network congestion control, we analyse the robust stability of the closed-loop system in the face of delay uncertainties that are present in data networks due to queuing. In particular, by applying a geometric approach, we derive a bound on the proportional controller gain which is necessary and sufficient to guarantee the closed-loop stability for a given bound on the delay uncertainty. 相似文献
75.
Nunzia Carbonara 《国际生产研究杂志》2018,56(15):5249-5271
The purpose of this paper is to assess the value of postponement as strategy for mitigating supply chain disruptions. To accomplish this objective, we develop a real option computational model that quantifies the value of postponement in mitigating both supply and demand disruptions by taking into account the value of managerial flexibility to decide whether exploiting or not the strategy, if and when disruptions occur, and whenever product differentiation proves valuable based on information available at that time. Numerical experiments show the importance of incorporating an option valuation method when pricing the value of postponement. This ensures managers implement postponement only when it is valuable, thus avoiding burdening the company with its initial sunk costs. By modelling the postponement implementation under different conditions, we identify the situations in which postponement performs better as supply chain disruptions mitigation strategy. We derive the operational configurations, in terms of decoupling point position, and external conditions, in terms of riskiness of the environment, which make the postponement an effective mitigation strategy. 相似文献
76.
Nunzia DOnofrio Elisa Martino Giuseppina Chianese Francesca Coppola Luigi Picariello Luigi Moio Maria Luisa Balestrieri Angelita Gambuti Martino Forino 《International journal of molecular sciences》2021,22(11)
Dietary phenolic compounds possess potent bioactivity against inflammatory pathways of chronic inflammatory conditions, such as type 2 diabetes. Here, the phenolic profile and bioactivity of Italian red wines Gaglioppo, Magliocco, and Nerello Mascalese were characterized. NMR, HPLC/UV-Vis and spectrophotometric characterization showed that Magliocco was the richest wine in monomeric anthocyanins (two-fold), catechins, and low molecular weight phenolics (LMWP). A positive correlation was observed between the polyphenolic content and antioxidant capacity (p < 0.05), with Magliocco displaying the highest antioxidant capacity (p < 0.01). In vitro evidence on the endothelial cell models of insulin resistance and hyperglycemia showed the ability of Magliocco to reduce reactive oxygen species (ROS) (p < 0.01) and cytokine release (p < 0.01) and to upregulate SIRT1 and SIRT6 (p < 0.01). On the whole, the results indicated that the quantitative and qualitative phenolic profiles of red wines influence their in vitro beneficial effects on oxidative and proinflammatory milieu in endothelial cells, showing a positive modulation of SIRT1 and SIRT6, both implied in vascular aging. 相似文献
77.
A method of simple implementation is presented for the measurement of the specific heat of thick film layers. It has to do with a system, operating at room temperature in accordance with a dynamic non-adiabatic technique, whose function regards the transient phase of a heating process between two steady states. It consists of a compact ensemble of three elements: a small plate thermistor serving as a heater, an alumina disk as a sample support and a tiny calibrated thermistor as a temperature sensor. The voltage across the heater and temperature from the sensor are monitored. An accurate evaluation of the dissipated energy allows the absorbed energy, responsible for the temperature variation, to be brought out. That makes possible the determination of thermal capacity of a small mass material deposited on a substrate. The achievement of the result simply involves the recording of a voltage and temperature during the transient phase, a fitting procedure with given analytical functions and a mathematical elaboration. The measuring system, its calibration procedure together with the transient operation are described. An application concerning screenprinted ferroelectric thick films on alumina substrate is presented and the results discussed. 相似文献
78.
De Cicco G. Morten B. Prudenziati M. 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》1997,44(5):992-996
A new ultrasonic transducer operating in air and fabricated by thick film technology is presented. It consists of a composite mechanical structure in which three active elements, made with planar alumina substrates supporting PZT-based piezoelectric films, behave as elastic guides. The active elements have a constant rectangular cross-section and are radially placed, 120° apart. They are mounted between a rigid base (operating as the acoustic backing) and an alumina disk. On both sides of each substrate a piezoelectric layer has interdigital thick-film electrodes embedded in layer itself, so that it can be polarized parallel to the long side of the active element; consequently, it allows the creation of periodic surface stresses responsible for symmetric extensional strains in the alumina plates. The elements, synchronously driven in phase, form, with the disk, a vibrating resonant structure, which radiates acoustic energy perpendicular to the disk surface. The assembly of active elements, acoustic backing and radiating disk forms a composite ultrasonic transducer operating in air without the need of any acoustic matching layer. Among the prominent features offered by the transducer design are: a transduction efficiency of 25% at an exiting voltage of 100 Vp and a high directivity of the emitted beam 相似文献
79.
80.
Lazzeri L Cascone MG Danti S Serino LP Moscato S Bernardini N 《Journal of materials science. Materials in medicine》2007,18(7):1399-1405
Biodegradable synthetic polymers such as poly(lactic acid) (PLA) are widely used to prepare scaffolds for cell transplantation
and tissue growth, using different techniques set up for the purpose. However the poor hydrophilicity of these polymers represents
the main limitation to their use as scaffolds because it causes a low affinity for the cells. An effective way to solve this
problem could be represented by the addition of biopolymers that are in general highly hydrophilic. The present work concerns
porous biodegradable sponge-like systems based on poly(l-lactic acid) (PLLA) and gelatine. Morphology and porosity characteristics of the sponges were studied by scanning electron
microscopy and mercury intrusion porosimetry respectively. Blood compatibility was investigated by bovine plasma fibrinogen
(BPF) adsorption test and platelet adhesion test (PAT). The cell culture method was used in order to evaluate the ability
of the matrices to work as scaffolds for tissue regeneration. The obtained results indicate that the sponges have interesting
porous characteristics, good blood compatibility and above all good ability to support cell adhesion and growth. In fact viable
and metabolically active animal cells were found inside the sponges after 8 weeks in culture. On this basis the systems produced
seem to be good candidates as scaffolds for tissue regeneration. 相似文献