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41.
Rheokinetic and phase separation behavior of diglycidylether of bisphenol‐A–4,4′‐diaminodiphenyl methane epoxy mixtures, modified with a constant amount (15 wt %) of poly(methyl methacrylate) (PMMA), have been investigated. Stoichiometric epoxy/amine mixtures precured at 80°C several times presented various levels of miscibility. Differential scanning calorimetry (DSC) and dynamic mechanic thermal analysis were used for rheokinetic studies of curing and also for testing the thermal behavior of the fully cured mixtures. Phase separation, through curing, was simultaneously studied by transmission optical microscopy and DSC, showing an excellent correlation between the results obtained with both techniques. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 772–780, 1999 相似文献
42.
Amalia Di Petrillo Celestino Santos-Buelga Benedetta Era Ana Maria González-Paramás Carlo Ignazio Giovanni Tuberoso Rosaria Medda Francesca Pintus Antonella Fais 《Food science and biotechnology》2018,27(1):139-146
Sardinian honeys obtained from different floral sources (Arbutus, Asphodelus, Eucalyptus, Thistle, and Sulla) were evaluated for their ability to inhibit tyrosinase and xanthine oxidase enzymes and for their antioxidant activity. Physicochemical parameters, total phenolic, and flavonoids content were also determined. Honey from Arbutus flowers had the highest antioxidant activity followed by Eucalyptus and Thistle ones. These three honeys showed good tyrosinase and xanthine oxidase inhibition properties. Thus, these Sardinian honeys could have a great potential as antioxidant sources for pharmaceutical and cosmetic applications. 相似文献
43.
Laura Russo Stefano Zanini Paolo Giannoni Elena Landi Anna Villa Monica Sandri Claudia Riccardi Rodolfo Quarto Silvia M. Doglia Francesco Nicotra Laura Cipolla 《Journal of materials science. Materials in medicine》2012,23(11):2727-2738
The development of advanced materials with biomimetic features in order to elicit desired biological responses and to guarantee tissue biocompatibility is recently gaining attention for tissue engineering applications. Bioceramics, such as hydroxyapatite-based biomaterials are now used in a number of different applications throughout the body, covering all areas of the skeleton, due to their biological and chemical similarity to the inorganic phases of bones. When bioactive sintered hydroxyapatite (HA) is desired, biomolecular modification of these materials is needed. In the present work, we investigated the influence of plasma surface modification coupled to chemical grafting on the cell growth compliance of HA 3D scaffolds. 相似文献
44.
Benedetta Marmiroli Gianluca Grenci Fernando Cacho-Nerin Barbara Sartori Peter Laggner Luca Businaro Heinz Amenitsch 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2010,268(3-4):329-333
Recently, we have designed, fabricated and tested a free-jet micromixer for time resolved small angle X-ray scattering (SAXS) studies of nanoparticles formation in the <100 μs time range. The microjet has a diameter of 25 μm and a time of first accessible measurement of 75 μs has been obtained. This result can still be improved. In this communication, we present a method to estimate whether a given chemical or biological reaction can be investigated with the micromixer, and to optimize the beam size for the measurement at the chosen SAXS beamline. Moreover, we describe a system based on stereoscopic imaging which allows the alignment of the jet with the X-ray beam with a precision of 20 μm. The proposed experimental procedures have been successfully employed to observe the formation of calcium carbonate (CaCO3) nanoparticles from the reaction of sodium carbonate (Na2CO3) and calcium chloride (CaCl2). The induction time has been estimated in the order of 200 μs and the determined radius of the particles is about 14 nm. 相似文献
45.
B. Riccardi P. Gavila R. Giniatulin V. Kuznetsov R. Rulev N. Klimov D. Kovalenko V. Barsuk V. Koidan S. Korshunov 《Fusion Engineering and Design》2013,88(9-10):1673-1676
The experimental evaluation of the divertor plasma facing components (PFCs) lifetime under transient events, such as edge localized modes (ELMs) and high heat flux (HHF) thermal fatigue expected during ITER normal operations and slow transient events is here presented. The experiments have been performed in the frame of an EU/RF collaboration. For carbon fiber composite material the erosion is caused by PAN fiber damage whilst the erosion of tungsten is determined by the melt layer movement and crack formation. The conclusion of this study is that, in addition to the structural change produced in the armor materials by ELMs-like loads, some mock ups showed also a degradation of the thermal fatigue performances 相似文献
46.
M. Pisarra A. SindonaP. Riccardi 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2011,269(9):981-984
Electron excitation and emission phenomena, due to Na+ ion impact on Au (1 0 0) surfaces, are studied at incident projectile energies below the threshold for kinetic electron emission. The trajectories and velocities of the projectile and the target atoms are simulated with molecular dynamics. This information are used to calculate the energy loss by electronic stopping as a series of discrete events, localized in space and time, that are treated as sources of excitation energy. The diffusion of the energy deposited by the projectile into the solid is converted into electron yield as proposed by Duvenbeck and coworkers [14]. The results show similar trends to available experimental data. 相似文献
47.
Silvia Francesca Storti Emanuela Formaggio Deborah Moretto Alessandra Bertoldo Francesca Benedetta Pizzini Alberto Beltramello Antonio Fiaschi Gianna Maria Toffolo Paolo Manganotti 《Magma (New York, N.Y.)》2014,27(2):171-184
Objective
Among other neuroimaging techniques, functional magnetic resonance imaging (fMRI) can be useful for studying the development of motor fatigue. The aim of this study was to identify differences in cortical neuronal activation in nine subjects on three motor tasks: right-hand movement with minimum, maximum, and post-fatigue maximum finger flexion.Materials and methods
fMRI activation maps for each subject and during each condition were obtained by estimating the optimal model of the hemodynamic response function (HRF) out of four standard HRF models and an individual-based HRF model (ibHRF).Results
ibHRF was selected as the optimal model in six out of nine subjects for minimum movement, in five out of nine for maximum movement, and in eight out of nine for post-fatigue maximum movement. As compared to maximum movement, a large reduction in the total number of active voxels (primary sensorimotor area, supplementary motor area and cerebellum) was observed in post-fatigue maximum movement.Conclusion
This is the first approach to the evaluation of long-lasting contraction effort in healthy subjects by means of the fMRI paradigm with the use of an individual-based hemodynamic response. The results may be relevant for defining a baseline in future studies on central fatigue in patients with neuropathological disorders. 相似文献48.
Domenico Strazza Benedetta Grassi Marco Demori Vittorio Ferrari Pietro Poesio 《Chemical engineering science》2011,66(12):6099
An analysis of high viscosity oil/water flow in horizontal and slightly inclined pipe is presented. We propose experimental flow maps – in particular we focus on the core-annular flow pattern boundary – pressure drops, and oil hold-up measurements. Experimental data are used to validate some models present in literature. Since hold-up measurement in liquid–liquid systems is particularly challenging and, therefore, only few data are available in literature, they are analyzed and commented in detail. The slip ratio computed by hold-up data is also provided and analyzed. 相似文献
49.
P. Di Filippo C. Riccardi F. Incoronato F. Sallusti S. Spicaglia A. Cecinato 《Polycyclic Aromatic Compounds》2013,33(5):393-406
The organic fraction of airborne particulate matter includes a wide variety of organic compounds, but the present research focus is on Polycyclic Aromatic Hydrocarbons (PAHs) and their nitrated derivatives (nitro-PAHs) because of the well-known health risk associated with these organics. In order to identify and assess the sources of hydrocarbon inputs into the environment n-alkanes content and the relative carbon preference index were utilized. Special consideration was given to nitro-PAHs. The aim of this work was to demonstrate the presence in atmosphere of nitro-PAHs not usually studied, which may be responsible for part of the high direct-acting mutagenic activity of unknown origin observed for the airborne particulate material. Of the 38 particulate-associated nitro-PAH compounds measured, 21 were described for the first time and 17 were detected in real samples, although those 21 nitro-PAHs were reported as positional isomers of corresponding PAHs, with the position of the NO2 group not determined. 相似文献
50.
A.Z. Simões E.C. Aguiar C.S. Riccardi E. Longo J.A. Varela 《Materials Characterization》2009,60(5):353-356
Fatigue-free Bi3.25La0.75Ti3O12 (BLT) thin films were grown on LaNiO3 bottom electrodes grown in a microwave furnace at 700 °C for 10 min from the polymeric precursor method. It was found that LaNiO3 (LNO) bottom electrode with pseudocubic structure strongly promote the formation of (00l) texture of BLT films. The remanent polarization (Pr) and the drive voltage (Vc) were 11 μC/cm2 and 1.3 V respectively, and are better than the values found in the literature. The polarization of the Au/BLT/LNO/SiO2/Si (100) capacitors with a thickness of 280 nm exhibited no degradation after 1 × 1010 switching cycles at an applied voltage of 5 V with a frequency of 1 MHz. After several tests the capacitors retain 77% of its polarization upon a retention time of 104 s. 相似文献