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51.
Paola Fabbri Massimo Messori Monica Montecchi Francesco Pilati Rosa Taurino Claudio Tonelli Maurizio Toselli 《应用聚合物科学杂志》2006,102(2):1483-1488
A commercial perfluoropolyether containing alkoxysilane functionalities was employed to prepare organic–inorganic hybrid coatings by using the sol‐gel process in the presence of tetraethoxysilane. Contact angle analysis revealed a strong hydrophobic and oleophobic character of the coatings almost independently from the molecular weight of the starting fluorinated oligomer. Surface tension values were in the range of 14–16 mN/m, suggesting a preferential segregation of fluorinated segments onto the surface of the coating. Atomic force microscopy showed the presence very smooth surfaces permitting to neglect the contribution of the surface roughness to wettability. Friction coefficient values were markedly lower with respect to the value of uncoated glass substrate. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1483–1488, 2006 相似文献
52.
An experimental study was carried out on the ultrafiltration (UF) of protein-containing solutions under different conditions, as compared with a solution of a linear synthetic polymer. Three different fluidynamic regimes were investigated, namely, unstirred batch system, stirred batch system, and recirculating system. The results obtained substantially agree with the predictions of the gel polarization model. A significant effect of the electrolytes on the UF flux has been observed, which can be attributed to solute–solute interaction. The influence of different UF membranes has also been investigated. 相似文献
53.
Minh-Son Dao Duc-Tien Dang-Nguyen Francesco G. B. De Natale 《Multimedia Tools and Applications》2014,70(1):25-53
Analyzing personal photo albums for understanding the related events is an emerging trend. A reliable event recognition tool could suggest appropriate annotation of pictures, provide the context for single image classification and tagging, achieve automatic selection and summarization, ease organization and sharing of media among users. In this paper, a novel method for fast and reliable event-type classification of personal photo albums is presented. Differently from previous approaches, the proposed method does not process photos individually but as a whole, exploiting three main features, namely Saliency, Gist, and Time, to extract an event signature, which is characteristic for a specific event type. A highly challenging database containing more than 40.000 photos belonging to 19 diverse event-types was crawled from photo-sharing websites for the purpose of modeling and performance evaluation. Experimental results showed that the proposed approach meets superior classification accuracy with limited computational complexity. 相似文献
54.
Stefano Cozzini Deepika Vaddi Savita Goel Francesco De Giorgi S. K. Dash 《Journal of Grid Computing》2014,12(2):303-320
In this paper, we present a possible approach to use different Grid infrastructures across Europe and India for regional climate simulations and discuss in details the advantages and limitations in using them. The application taken into consideration is the Regional Climate Model RegCM4, which has been recently re-written for making it more efficient and easier to be fully exploited on any kind of computational infrastructure. We describe here the methods applied to port this package on the Grid infrastructures made available by the EU-IndiaGrid project. We also discuss different approaches, the way to run the model on both European and Indian infrastructures and our promising approach to deal with data management issues. Use of RegCM on Grid infrastructure has further been compared with that on HPC resources. The domain worked upon for these tests is the South-Asia CORDEX domain, which is of great importance for the Indian Summer Monsoon. Our final conclusion is that, for certain class of experiments, RegCM4 model can be efficiently and easily integrated on Grid infrastructures, by means of the procedures described in this paper. 相似文献
55.
Vladimir A. Tyurin Gianfranca Carta Yulia Y. Tyurina Sebastiano Banni Billy W. Day Francesco P. Corongiu Valerian E. Kagan 《Lipids》1997,32(2):131-142
Recent studies provide extensive evidence for the importance of carotenoids in protecting against oxidative stress associated
with a number of diseases. In particular, reactions of carotenoids with phenoxyl radicals generated by peroxidasecatalyzed
one-electron metabolism of phenolic compounds may represent an important antioxidant function of carotenoids. To further our
understanding of the antioxidant mechanisms of carotenoids, we used in the present work two different phenolic compounds,
phenol and a polar homologue of vitamin E (2,2,5,7,8-pentamethyl-6-hydroxychromane, PMC), as representatives of two different
types of phenols to study reactions of their respective phenoxyl radicals with carotenoids in cells and in model systems.
We found that phenoxyl radicals of PMC did not oxidize β-carotene in either HL-60 cells or in model systems with horseradish
peroxidase (HRP)/H2O2. In contrast, the phenoxyl radicals generated from phenol (by native myeloperoxidase in HL-60 cells or HRP/H2O2 in model systems) effectively oxidized β-carotene and other carotenoids (canthaxanthin, lutein, lycopene). One-electron reduction
of the phenoxyl radical by ascorbate (assayed by electron spin resonance-detectable formation of semidehydroascorbyl radicals)
prevented HRP/H2O2-induced oxidation of β-carotene. PMC, but not phenol, protected β-carotene against oxidation induced by a lipid-soluble azo-initiator
of peroxyl radicals. No adducts of peroxidase/phenol/H2O2-induced β-carotene oxidation intermediates with phenol were detected by high-performance liquid chromatography-mass spectrometry
analysis of the reaction mixture. Since carotenoids are essential constituents of the antioxidant defenses in cells and biological
fluids, their depletion through the reaction with phenoxyl radicals formed from endogenous, nutritional and environmental
phenolics, as well as phenolic drugs, may be an important factor in the development of oxidative stress. 相似文献
56.
Edoardo Zonta Francesco Valentini Andrea Dorigato Luca Fambri Alessandro Pegoretti 《Polymer Engineering and Science》2021,61(1):136-153
The thermomechanical behavior of ethylene propylene diene monomer (EPDM) foams produced with the salt leaching method has been investigated and compared with the behavior of EPDM foams obtained from conventional blowing agents. Moreover, the salt-leaching process has been optimized to minimize salt residues and the influence of different parameters (such as average particle size and particle size distribution) has been investigated. Scanning electron microscopy and density measurements highlighted that salt-leaching leads to the formation of open-cell porosity with cell dimensions of around 60 to 80 μm, while foams obtained with the two traditional foaming agents lead to closed-cell porosity. Compression set values indicate that the behavior of the foams produced with salt leaching are more similar to the unfoamed rubber, characterized by higher elasticity and low residual deformation. Two theoretical models were successfully applied to the compression curves (Mooney-Rivlin and Exponential-Logarithmic) and they highlighted the effect of foaming on the properties of EPDM rubber and in particular the higher chain extensibility obtained through the salt leaching foaming method. 相似文献
57.
Frank Bonnet Yuta Kato José Halloy Francesco Mondada 《Artificial Life and Robotics》2016,21(3):239-246
Robotic fish are nowadays developed for various types of research, such as bio-inspiredrobotics, biomimetics and animal behavior studies. In the context of our research on the social interactions of the zebrafish Danio Rerio, we developed a miniature robotic fish lure for direct underwater interaction with the living fish. This remotely controlled and waterproof device has a total length of 7.5 cm with the same size ratio as zebrafish and is able to beat its tail with different frequencies and amplitudes, while following the group of living animals using a mobile robot moving outside water that is coupled with the robotic lure using magnets. The robotic lure is also equipped with a rechargeable battery and can be used autonomously underwater for experiments of up to 1 h. We performed experiments with the robot moving inside an aquarium with living fish to analyze its impact on the zebrafish behavior. We found that the beating rate of the tail increased the attractiveness of the lure among the zebrafish shoal. We also demonstrated that the lure could influence a collective decision of the zebrafish shoal, the swimming direction, when moving with a constant linear speed inside a circular corridor. This new robotic fish design and the experimental results are promising for the field of fish–robot interaction. 相似文献
58.
Xin Lin Chris M. J. Tampère Francesco Viti Ben Immers 《Networks and Spatial Economics》2016,16(1):349-369
Increasing numbers of hard environmental constraints are being imposed in urban traffic networks by authorities in an attempt to mitigate pollution caused by traffic. However, it is not trivial for authorities to assess the cost of imposing such hard environmental constraints. This leads to difficulties when setting the constraining values as well as implementing effective control measures. For that reason, quantifying the cost of imposing hard environmental constraints for a certain network becomes crucial. This paper first indicates that for a given network, such cost is not only related to the attribution of environmental constraints but also related to the considered control measures. Next, we present an assessment criterion that quantifies the loss of optimality under the control measures considered by introducing the environmental constraints. The criterion can be acquired by solving a bi-level programming problem with/without environmental constraints. A simple case study shows its practicability as well as the differences between this framework and other frameworks integrating the environmental aspects. This proposed framework is widely applicable when assessing the interaction of traffic and its environmental aspects. 相似文献
59.
Michele Amoretti Alessandro Grazioli Francesco Zanichelli 《Peer-to-Peer Networking and Applications》2016,9(6):1226-1241
The rise of Cloud Computing has progressively dimmed the interest in volunteer and peer-to-peer computing, in general. However, efficient and cost-effective large scale distributed collaborative environments cannot be achieved leveraging upon the Cloud alone. In this paper, we propose a novel hybrid P2P/cloud approach where components and protocols are autonomically configured according to specific target goals, such as cost-effectiveness, reliability and availability. The proposed approach is based on the Networked Autonomic Machine (NAM) framework, which allows distributed system designers to include different kinds of cost and performance constraints. As an example, we show how the NAM-based approach can be used to design collaborative storage systems, enabling the definition of an autonomic policy to decide, according to cost minimization and data availability goals, how to part data chunks among peer nodes and Cloud, based on the local perception of the P2P network. 相似文献
60.
Rachid El-Azouzi Francesco De Pellegrini Habib B.A. Sidi Vijay Kamble 《Computer Networks》2013,57(4):1003-1018
In this paper, we apply evolutionary games to non-cooperative forwarding control in Delay Tolerant Networks (DTNs). The main focus is on mechanisms to rule the participation of the relays to the delivery of messages in DTNs. Thus, we express the success probability as a function of the competition that takes place within a large population of mobiles, and we characterize the effect of reward-based mechanisms on the performance of such systems. Devices acting as active relays, in fact, sacrifice part of their batteries in order to support message replication and thus increase the probability to reach the destination. In our scheme, a relay can choose the strategy by which they participate to the message relaying. A mobile that participates receives a unit of reward based on the reward mechanism selected by the network. A utility function is introduced as the difference between the expected reward and the energy cost, i.e., the cost spent by the relay to sustain forwarding operations. We show how the evolution dynamics and the equilibrium behavior (called Evolutionary Stable Strategy – ESS) are influenced by the characteristics of inter contact time, energy expenditure and pricing characteristics.We extend our analysis to mechanisms that the system can introduce in order to have the message delivered to the destination with high probability within a given deadline and under energy constraints which bound the number of released copies per message. Finally, we apply our findings in order to devise decentralized forwarding algorithms that are rooted in the theory of stochastic approximations. Thus, we demonstrate that the ESS can be attained without complete knowledge of the system state and letting the source monitor number of released copies per message only. We provide extensive numerical results to validate the proposed scheme. 相似文献