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排序方式: 共有379条查询结果,搜索用时 15 毫秒
31.
32.
A. Chiappone Jijeesh R. NairC. Gerbaldi L. JabbourR. Bongiovanni E. ZenoD. Beneventi N. Penazzi 《Journal of power sources》2011,196(23):10280-10288
Methacrylic-based thermo-set gel-polymer electrolyte membranes obtained by a very easy, fast and reliable free radical photo-polymerisation process and reinforced with microfibrillated cellulose particles are here presented. The morphology of the composite electrolytes is investigated by scanning electron microscopy and their thermal behaviour (characteristic temperatures, degradation temperature) are investigated by thermo-gravimetric analysis and differential scanning calorimetry. The composite membranes prepared exhibit excellent mechanical properties, with a Young's modulus as high as about 80 MPa at ambient temperature. High ionic conductivity (approaching 10−3 S cm−1 at 25 °C) and good overall electrochemical performances are maintained, enlightening that such specific approach would make these hybrid organic, cellulose-based composite polymer electrolyte systems a strong contender in the field of thin and flexible lithium based power sources. 相似文献
33.
Terenzio Bertuzzi Silvia Rastelli Annalisa Mulazzi Gianluca Donadini Amedeo Pietri 《Food Control》2011,22(12):2059-2064
The occurrence of ochratoxin A, trichothecenes, fumonisins and aflatoxins in a sample of 106 beers produced in several European countries, was investigated. The analyses were conducted using high-performance liquid chromatography with fluorimetric detection for ochratoxin A and aflatoxins, gas-chromatography and high-performance liquid chromatography, both coupled with mass spectrometer, for trichothecenes and fumonisins, respectively. Aflatoxins were not detected in any samples, whereas ochratoxin A, deoxynivalenol and fumonisins were found in a relatively high number of samples. Their presence was at low levels in all samples; however, some differences were observed between the European countries. As regards ochratoxin A, beer samples from southern Europe showed levels always lower than 0.040 μg l?1, while the samples from other European countries showed significantly higher values, up to 0.189 μg l?1 (P < 0.001). For fumonisins, the levels of Italian beers were significantly higher compared to the samples from other countries (P = 0.006). 相似文献
34.
Novella Bartolini Tiziana Calamoneri Emanuele Guido Fusco Annalisa Massini Simone Silvestri 《Wireless Networks》2010,16(3):607-625
Mobile sensor networks are important for several strategic applications devoted to monitoring critical areas. In such hostile
scenarios, sensors cannot be deployed manually and are either sent from a safe location or dropped from an aircraft. Mobile
devices permit a dynamic deployment reconfiguration that improves the coverage in terms of completeness and uniformity. In
this paper we propose a distributed algorithm for the autonomous deployment of mobile sensors called Push & Pull. According
to our proposal, movement decisions are made by each sensor on the basis of locally available information and do not require
any prior knowledge of the operating conditions or any manual tuning of key parameters. We formally prove that, when a sufficient
number of sensors are available, our approach guarantees a complete and uniform coverage. Furthermore, we demonstrate that
the algorithm execution always terminates preventing movement oscillations. Numerous simulations show that our algorithm reaches
a complete coverage within reasonable time with moderate energy consumption, even when the target area has irregular shapes.
Performance comparisons between Push & Pull and one of the most acknowledged algorithms show how the former one can efficiently
reach a more uniform and complete coverage under a wide range of working scenarios. 相似文献
35.
Giulia Bernardini Maurizio Comanducci Stefania Bambini Giovanni Renzone Andrea Scaloni Giovanna Morelli Mark Achtman Giulio Ratti Annalisa Santucci 《Proteomics. Clinical applications》2009,3(10):1251-1254
We previously described the first reference map for the proteome of one strain of serogroup A Neisseria meningitidis (MenA), a major cause of epidemic meningitis in humans. As a preliminary finding, in that work we noted that 2‐DE protein maps of closely related MenA isolates from different epidemics spreads could be easily compared to detect minor differences and that 2‐DE phenotypes attributable to the well‐known epidemiological marker tbpB agreed with the genoclouds model of MenA epidemiological variation during pandemic waves. We explored here the possibility that an extended comparative study of 2‐DE maps of isolates representative of the nine genoclouds described by Achtman and collaborators could be used to discriminate between strains otherwise undistinguishable. We showed the example of 14 proteins with different 2‐DE spot patterns in different genoclouds that could be considered as putative tracers for alike‐strains discrimination. We introduce the novel concept that comparative proteomics can be useful in identifying new epidemiological markers for N. meningitidis. 相似文献
36.
Different strategies for modelling and reducing the effect of uncertainties on the dynamic behaviour of coupled structures are discussed in this paper. In assembled structures, each component satisfies specifications about material properties and dimensional tolerances. Variability of design specifications within the tolerance field may affect the dynamic behaviour of the assembled structure more than that of any individual component substructure. Among modelling strategies, non-predictive techniques such as post-processing of data from a set of randomly assembled structures and analysis of sensitivities to uncertain variables are considered. However, emphasis is placed on a less trivial yet simple strategy such as the use of design of experiments to fit a regression model. Different reduction strategies are considered according to whether small design changes (even revised tolerance allocation) are still possible or not. In the latter case, selective assembly is extended to problems where the performance requirement is not the clearance between two parts, but a prescribed dynamic behaviour. 相似文献
37.
Annalisa Di Piazza Maria Carmela Di Piazza Antonella Ragusa Gianpaolo Vitale 《Renewable Energy》2011,36(3):1063-1074
This paper presents a statistical approach based on the k-means clustering technique to manage environmental sampled data to evaluate and to forecast of the energy deliverable by different renewable sources in a given site. In particular, wind speed and solar irradiance sampled data are studied in association to the energy capability of a wind generator and a photovoltaic (PV) plant, respectively. The proposed method allows the sub-sets of useful data, describing the energy capability of a site, to be extracted from a set of experimental observations belonging the considered site. The data collection is performed in Sicily, in the south of Italy, as case study. As far as the wind generation is concerned, a suitable generator, matching the wind profile of the studied sites, has been selected for the evaluation of the producible energy. With respect to the photovoltaic generation, the irradiance data have been taken from the acquisition system of an actual installation. It is demonstrated, in both cases, that the use of the k-means clustering method allows data that do not contribute to the produced energy to be grouped into a cluster, moreover it simplifies the problem of the energy assessment since it permits to obtain the desired information on energy capability by managing a reduced amount of experimental samples. In the studied cases, the proposed method permitted a reduction of the 50% of the data with a maximum discrepancy of 10% in energy estimation compared to the classical statistical approach. Therefore, the adopted k-means clustering technique represents an useful tool for an appropriate and less demanding energy forecast and planning in distributed generation systems. 相似文献
38.
Polyphasic characterization of indigenous lactobacilli and lactococci from PDO Canestrato Pugliese cheese 总被引:1,自引:0,他引:1
Lucia Aquilanti Emanuele Zannini Annalisa Zocchetti Andrea Osimani Francesca Clementi 《LWT》2007,40(7):1146-1155
A polyphasic approach, involving both genotypic and phenotypic analyses was used to characterize 33 isolates of lactic acid bacteria from the raw milk Protected Designation of Origin (PDO) Canestrato Pugliese cheese, in order to select candidate strains that can be used as autochthonous starter cultures in the dairy industry. Randomly amplified polymorphic DNA (RAPD) analysis and clustering by the unweighted pair-group method with arithmetic averages (UPGMA) were used to evaluate the genotypic diversity, while phenotypic characterization was performed through miniaturized assays and traditional biochemical tests. Technological properties of major interest for cheese-making (acidification, tendency to lysis, proteolytic and peptidase activity) were also evaluated, and selected subset of data was statistically examined by the one-way ANOVA and the Tukey-Kramer HSD test, to highlight strain-specific and species-specific differences among the isolates. A high degree of diversity appeared in the phenotypic and technological traits in opposition to a relatively low genotypic diversity. Although none of the isolates showed the best performances in all the activities, an appropriate mixture of strains could be selected for providing an efficacious autochthonous starter culture. 相似文献
39.
Immacolata Ruggiero Monica Terracciano Nicola M Martucci Luca De Stefano Nunzia Migliaccio Rosarita Tatè Ivo Rendina Paolo Arcari Annalisa Lamberti Ilaria Rea 《Nanoscale research letters》2014,9(1):329
Diatomite is a natural fossil material of sedimentary origin, constituted by fragments of diatom siliceous skeletons. In this preliminary work, the properties of diatomite nanoparticles as potential system for the delivery of drugs in cancer cells were exploited. A purification procedure, based on thermal treatments in strong acid solutions, was used to remove inorganic and organic impurities from diatomite and to make them a safe material for medical applications. The micrometric diatomite powder was reduced in nanoparticles by mechanical crushing, sonication, and filtering. Morphological analysis performed by dynamic light scattering and transmission electron microscopy reveals a particles size included between 100 and 300 nm. Diatomite nanoparticles were functionalized by 3-aminopropyltriethoxysilane and labeled by tetramethylrhodamine isothiocyanate. Different concentrations of chemically modified nanoparticles were incubated with cancer cells and confocal microscopy was performed. Imaging analysis showed an efficient cellular uptake and homogeneous distribution of nanoparticles in cytoplasm and nucleus, thus suggesting their potentiality as nanocarriers for drug delivery.
PACS
87.85.J81.05.Rm; 61.46. + w 相似文献40.
Annalisa Dalmoro Anna Angela Barba Marina Lamberti Mina Mazzeo Vincenzo Venditto Gaetano Lamberti 《Journal of Materials Science》2014,49(17):5986-5996
In this work, the degradation phenomena and the release kinetics of an active molecule from matrices systems made of random copolymers of ε-caprolactone (CL) and l-lactide (LA) were investigated by exposing the matrices, shaped as thin films, to simulated physiological environments. α-tocopherol was incorporated into the films as hydrophobic model molecule with the aim to investigate both its release pattern and its effect on erosion phenomena. In particular, the films have been kept at controlled conditions (temperature, stirring, pH) and they were characterized in terms of weight loss, water uptake, thermal properties, and change of number average molecular weight, in order to explain the molecule release kinetics and the degradation pathways of the copolymers. The main findings of this study are that the erosion phenomena take place significantly only when a critical value of the molecular mass was obtained in the sample; that the presence of the drug stabilizes the matrix and it decreases the rate of molecular mass decrease; and that crystallinity, reducing the chain mobility, causes lower erosion rates. 相似文献