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21.
Sorption isotherms of lemon juice (LE) powders with and without additives—18% maltodextrin (MA) or 18% gum Arabic (GA)—were determined at 20–50°C. Addition of additives was shown to affect the isotherms in such a way that, at the same water activity, samples LE + GA and LE + MA presented lower equilibrium moisture content and were not so affected by varying temperature. The net isosteric heats of sorption of juice powders with additives were higher (less negative) than those of lemon juice powders, suggesting that there are more active polar sites in the product without addition of GA or MA. In general, the quality properties decreased with the addition of maltodextrin and gum arabic and it was obtained similar values for LE + GA and LE + MA. 相似文献
22.
Anna Martinelli 《International journal of molecular sciences》2014,15(4):6488-6503
The reaction pathway during the formation of silica via a two-component “non-aqueou” sol-gel synthesis is studied by in situ time-resolved Raman spectroscopy. This synthetic route is followed with and without the addition of the protic ionic liquid 1-ethylimidazolium bis(trifluoromethanesulfonyl)imide (C2HImTFSI) in order to investigate its effect on the reaction pathway. We demonstrate that Raman spectroscopy is suitable to discriminate between different silica intermediates, which are produced and consumed at different rates with respect to the point of gelation. We find that half-way to gelation monomers and shorter chains are the most abundant silica species, while the formation of silica rings strongly correlates to the sol-to-gel transition. Thus, curling up of linear chains is here proposed as a plausible mechanism for the formation of small rings. These in turn act as nucleation sites for the condensation of larger rings and thus the formation of the open and polymeric silica network. We find that the protic ionic liquid does not change the reaction pathway per se, but accelerates the cyclization process, intermediated by the faster inclusion of monomeric species. 相似文献
23.
Emanuele Salerno Francesca Martinelli Anna Tonazzini 《International Journal on Document Analysis and Recognition》2013,16(2):177-187
The problem of see-through cancelation in digital images of double-sided documents is addressed. We show that a nonlinear convolutional data model proposed elsewhere for moderate show-through can also be effective on strong back-to-front interferences, provided that the recto and verso pure patterns are estimated jointly. To this end, we propose a restoration algorithm that does not need any classification of the pixels. The see-through PSFs are estimated off-line, and an iterative procedure is then employed for a joint estimation of the pure patterns. This simple and fast algorithm can be used on both grayscale and color images and has proved to be very effective in real-world cases. The experimental results we report in this paper demonstrate that our algorithm outperforms the ones based on linear models with no need to tune free parameters and remains computationally inexpensive despite the nonlinear model and the iterative solution adopted. Strategies to overcome some of the residual difficulties are also envisaged. 相似文献
24.
S. Sanna R. De Renzi G. Lamura C. Ferdeghini A. Martinelli A. Palenzona M. Putti M. Tropeano T. Shiroka 《Journal of Superconductivity and Novel Magnetism》2009,22(6):585-588
We report μSR measurements on SmFeAsO1−x
F
x
which helped us to identify the signature of diluted ferromagnetic inclusions, ubiquitous in the iron pnictides. These impurities
are characterized by a Curie temperature close to room temperature and they seem responsible for a non negligible magnetic
relaxation of the implanted muons, which should not be confused with intrinsic pnictide properties.
相似文献
25.
Mohammed Ismail José Rodellar Gennaro Carusone Marco Domaneschi Luca Martinelli 《Acta Mechanica》2013,224(3):525-547
This paper presents the results of an extensive series of simulation tests to identify the mechanical characteristics of an innovative isolation device known as the Roll-N-Cage (RNC) isolator. The seismic performance of an RNC passive control scheme is subsequently investigated on a model of the cable-stayed bridge benchmark. Starting from different configurations studied in the laboratory for a 1/10 reduced-scale prototype, the RNC isolator stiffness and damping properties are investigated in terms of cyclic tests with different parameters. Tests at the ultimate level state consisting of monotonic shear and axial loading have been also carried out as a part of the qualification process. The goal of this study is twofold: first, to examine the main integrated mechanisms of the RNC isolator through sophisticated 3D finite element simulation models using a multi-purpose finite element code. The main result of this step is to attempt modeling the force–displacement relationship using the standard Bouc–Wen model of smooth hysteresis. The second aim of this study is the numerical assessment of the device efficiency through its implementation into a bridge model considering several ground motions as external excitations. Based on these extensive studies, it was found that the RNC isolator is promising as a reliable isotropic horizontal isolation device for bridge structures. 相似文献
26.
Luciano?GamberiniEmail author Anna?Spagnolli Paolo?Cottone Massimiliano?Martinelli Laura?Bua 《Cognition, Technology & Work》2004,6(1):45-48
The purpose of this study is to see in which forms and under which conditions social presence turns into collaboration. Eight couples were asked to find some objects in a virtual environment in which collaboration was allowed but not mandatory. The qualitative analysis of the video recordings shows that all participants resorted to collaboration in forms that were justified by the requirements of the task, the environmental affordances and the different expertise.
相似文献
Luciano GamberiniEmail: Phone: +39-049-8276605Fax: +39-049-8276600 |
27.
Journal of Materials Science - 相似文献
28.
29.
The depolarizing properties of a fiber ring structure have been analyzed, and the analytical solution to the device optimization has been found. The result proves that a tunable fiber ring depolarizer can completely depolarize light for any input state of polarization. 相似文献
30.
Felix CL Bewley WW Vurgaftman I Bartolo RE Stokes DW Meyer JR Yang MJ Lee H Menna RJ Martinelli RU Garbuzov DZ Connolly JC Maiorov M Sugg AR Olsen GH 《Applied optics》2001,40(6):806-811
We review the recent progress of electrically injected and optically pumped mid-IR lasers based on antimonide quantum wells with the type II W configuration. W quantum-well diodes have achieved cw operation up to 195 K at lambda = 3.25 mum. Optically pumped devices that employ the diamond pressure bond heat sink have reached 290 K at 3 mum and 210 K at 6 mum. Pulsed power conversion efficiencies of up to 7% at 220 K have been attained by use of an optical pumping injection cavity approach, in which an etalon cavity for the pump beam significantly enhances its absorptance. The angled-grating distributed-feedback configuration has been used to obtain near-diffraction-limited output for an optical pumping stripe width of 50 mum. 相似文献