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511.
Corinna L. Koch Dandolo Marcello Picollo Costanza Cucci Peter Uhd Jepsen 《Journal of Infrared, Millimeter and Terahertz Waves》2016,37(11):1148-1156
The potentials of the Terahertz Time-Domain Imaging (THz-TDI) technique for a non-invasive inspection of panel paintings have been considered in detail. The THz-TD data acquired on a replica of a panel painting made in imitation of Italian Renaissance panel paintings were processed in order to provide insights as to the limits and potentials of the technique in detecting different kinds of underdrawings and paint layers. Constituent layers, construction techniques, and anomalies were identified and localized by interpreting the extracted THz dielectric stratigraphy. 相似文献
512.
The total-lipid composition of 21 lichens of the ascomycetous genera Cladonia (11) and Cladina (1) of the family Cladoniacea, Cladia (1), Parmotrema (3), Ramalina (2), Leptogium (1), Cetraria (1), and the basidiomycetous genus Dictyonema (1) was determined. Analyses of those of Dictyonema glabratum were carried out with a total extract and those obtained after successive extractions with various solvents. Each extract
was partitioned between n-heptane/isopropanol and 1 M sulfuric acid, giving triglycerides (TG) in the upper phase. Extracts were methanolyzed and the
resulting methyl esters were analyzed by gas chromatography-mass spectrometry. Methanolyzates of TG unexpectedly contained
esters of 9-oxodecanoic, 9-methyl-tetradecanoic, 6-methyl-tetradecanoic, 3-hydroxy-decanoic, nonanedioic, and decanedioic
acids, as well as common fatty acids. Fatty acid methyl ester profiles from the lichens were submitted to cluster analysis,
and the resulting dendogram showed a cluster consistent with Cladonia spp., suggesting an efficient aid to lichen taxonomy. The total carbohydrate content of each lipid extract was determined
by a modified phenol-sulfuric acid method, which compensated for the presence of pigments. 相似文献
513.
Juan Guillen-Scholten Farhad Arbab Frank de Boer Marcello Bonsangue 《Electronic Notes in Theoretical Computer Science》2006,154(1):121
In this paper, we discuss how to model systems that communicate through and are coordinated by mobile channels. Mainly, we focus on modeling the exogenous coordination behavior imposed by these channels. We use Petri Nets as our modeling language, for they provide a graphically and mathematically founded modeling formalism. We give Petri Nets for a set of mobile channel types. This allows us to construct models of applications, by taking the Petri Net of each component and each mobile channel, and composing them together. For this purpose, we define a special Petri Net composition function. We also discuss analysis and simulation of these models and their exogenous coordination behavior. 相似文献
514.
Low-cost mass fabrication methods and label-free capacitive biosensors are needed for many applications. This article presents a electronic microarrays, with single-chip implementations in CMOS technology. Although biochemical operations in CMOS-based arrays are almost the same as in optical devices, the simple readout of integrated CMOS sensors greatly facilitates system integration. These chips can perform a significant amount of sensor data processing and produce digital output signals in standardized form. They can be easily connected to simple, inexpensive, handheld or even wearable readers. However, these devices are in their infancy. Only a small subset of them are at the level of complete single-die integration of sensors, transducers, and data-conditioning circuits. Our purpose in this article is to outline the main technology, design, and implementation challenges involved in developing these highly integrated research prototypes. 相似文献
515.
In this work, several procedures for the fault detection and isolation (FDI) on general aviation aircraft sensors are presented. In order to provide a comprehensive wide-pectrum treatment, both linear and nonlinear, model-based and data-driven methodologies are considered. The main contributions of the paper are related to the development of both FDI polynomial method (PM) and FDI scheme based on the nonLinear geometric approach (NLGA). As to the PM, the obtained results highlight a good trade-off between solution complexity and resulting performances. Moreover, the proposed PM is especially useful when robust solutions are required for minimising the effects of modelling errors and noise, while maximising fault sensitivity. As to the NLGA, the proposed work is the first development and robust application of the NLGA to an aircraft model in flight conditions characterised by tight-oupled longitudinal and lateral dynamics. In order to verify the robustness of the residual generators related to the previous FDI techniques, the simulation results adopt a typical aircraft reference trajectory embedding several steady-tate flight conditions, such as straight flight phases and coordinated turns. Moreover, the simulations are performed in the presence of both measurement and modelling errors. Finally, extensive simulations are used for assessing the overall capabilities of the developed FDI schemes and a comparison with neural networks (NN) and unknown input Kalman filter (UIKF) diagnosis methods is performed. 相似文献
516.
517.
Costantini Marcello; Bueti Domenica; Pazzaglia Mariella; Aglioti Salvatore M. 《Canadian Metallurgical Quarterly》2007,21(2):242
The ability to detect left-sided stimuli (visual or tactile) was studied in visual and tactile extinction (RBD) patients and in healthy (C) subjects. Stimuli were single or double; double stimuli were always cross-modal and could be released across the 2 hemispaces or within the same hemispace. Moreover, the stimuli could be either simultaneous or separated by 1 of 3 different asynchronies (105, 505, 905 ms). C subjects were perfect in all conditions. RBD patients omitted the contralesional tactile stimulus in bilateral trials (across space, classical extinction). They also omitted the tactile stimulus in unilateral left trials (within hemispace). Both effects showed the same temporal modulation with lower extinction rates at longer stimulus onset asynchronies. Results suggest that attentional processing of a visual stimulus inhibits processing of a tactile one, even if both are delivered in the same contralesional hemispace. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
518.
Teresa Tropea Damiano Rigiracciolo Milena Esposito Marcello Maggiolini Maurizio Mandal 《International journal of molecular sciences》2022,23(11)
Increasing levels of estrogens across gestation are partly responsible for the physiological adaptations of the maternal vasculature to pregnancy. The G protein-coupled estrogen receptor (GPER) mediates acute vasorelaxing effects in the uterine vasculature, which may contribute to the regulation of uteroplacental blood flow. The aim of this study was to investigate whether GPER expression and vasorelaxation may occur following pregnancy. Elucidation of the functional signalling involved was also investigated. Radial uterine and third-order mesenteric arteries were isolated from non-pregnant (NP) and pregnant rats (P). GPER mRNA levels were determined and—concentration–response curve to the GPER-specific agonist, G1 (10−10–10−6 M), was assessed in arteries pre-constricted with phenylephrine. In uterine arteries, GPER mRNA expression was significantly increased and vasorelaxation to G1 was significantly enhanced in P compared with NP rats. Meanwhile, in mesenteric arteries, there was a similar order of magnitude in NP and P rats. Inhibition of L-type calcium channels and extracellular signal-regulated kinases 1/2 significantly reduced vasorelaxation triggered by G1 in uterine arteries. Increased GPER expression and GPER-mediated vasorelaxation are associated with the advancement of gestation in uterine arteries. The modulation of GPER is exclusive to uterine arteries, thus suggesting a physiological contribution of GPER toward the regulation of uteroplacental blood flow during pregnancy. 相似文献
519.
520.
Fabrizio Roncaglia Marcello Romagnoli Simone Incudini Elena Santini Manuel Imperato Luca Spinelli Alessandro di Bona Roberto Biagi Adele Mucci 《International Journal of Hydrogen Energy》2021,46(5):4407-4416
Bipolar plates (BPs) are key components of Proton Exchange Membrane Fuel Cells mainly employed in hydrogen-powered electric vehicles. Here, a reliable and detailed experimental method to prepare graphite-epoxy composites suitable for manufacturing BPs is reported. Dry and wet mixing procedures were compared and a simple composition was optimized, with regard to electrical conductivity. The adoption of wet mixing of the components and the choice of the conductive filler were the main factors that contributed to the achievement of good electrical and mechanical properties. The addition of a small percentage of carbon black as a secondary filler was also advantageous. The effects of molding parameters (pressure, temperature and time) on a fixed-composition graphite-epoxy composite were modeled using a Design Of Experiments approach, which provided valuable information for future improvements. Conductivity values well above the US DOE requirements were obtained. 相似文献