Search results for "Materials Science | Hot Paper"
showing 10 items of 1457 documents
Comparison among different rainfall energy harvesting structures
2018
In this paper, an experimental comparison between different rainfall harvesting devices through the study of the electrical rectifying circuit is proposed. In more detail, three harvesting structures are considered: the cantilever, the bridge and the floating circle. Different waveforms were acquired and discussed. The processed data were compared in order to suggest the best choice for the rectifying circuit, from the simplest one to that most frequently endorsed in the technical literature.
Computer simulation studies of finite-size broadening of solid–liquid interfaces: from hard spheres to nickel
2009
Using Molecular Dynamics (MD) and Monte Carlo (MC) simulations interfacial properties of crystal-fluid interfaces are investigated for the hard sphere system and the one-component metallic system Ni (the latter modeled by a potential of the embedded atom type). Different local order parameters are considered to obtain order parameter profiles for systems where the crystal phase is in coexistence with the fluid phase, separated by interfaces with (100) orientation of the crystal. From these profiles, the mean-squared interfacial width w^2 is extracted as a function of system size. We rationalize the prediction of capillary wave theory that w^2 diverges logarithmically with the lateral size o…
PLLA scaffolds produced by thermally induced phase separation (TIPS) allow human chondrocyte growth and extracellular matrix formation dependent on p…
2016
Damage of hyaline cartilage species such as nasoseptal or joint cartilage requires proper reconstruction, which remains challenging due to the low intrinsic repair capacity of this tissue. Implantation of autologous chondrocytes in combination with a biomimetic biomaterial represents a promising strategy to support cartilage repair. The aim of this work was to assess the viability, attachment, morphology, extracellular matrix (ECM) production of human articular and nasoseptal chondrocytes cultured in vitro in porous poly(L-lactic) (PLLA) scaffolds of two selected pore sizes (100 and 200 μm). The PLLA scaffolds with 100 and 200 μm pore sizes were prepared via ternary thermally induced ph…
New fitting scheme to obtain effective potential from Car-Parrinello molecular dynamics simulations: Application to silica
2008
A fitting scheme is proposed to obtain effective potentials from Car-Parrinello molecular dynamics (CPMD) simulations. It is used to parameterize a new pair potential for silica. MD simulations with this new potential are done to determine structural and dynamic properties and to compare these properties to those obtained from CPMD and a MD simulation using the so-called BKS potential. The new potential reproduces accurately the liquid structure generated by the CPMD trajectories, the experimental activation energies for the self-diffusion constants and the experimental density of amorphous silica. Also lattice parameters and elastic constants of alpha-quartz are well-reproduced, showing th…
Preventing early age chloride migration into low-carbon concrete
2019
The use of substituting cementitious materials (SCMs) to produce low-carbon concrete is escalating. This contributes to reducing the anthropogenic emission of CO2, and to reduce harmful temperature gradients during cement hydration in massive structures. Mature low-carbon concretes are known to perform well on both strength and durability. However, the maturity process is slow compared to that of standard concrete. Structures made from low-carbon concrete are subject to penetration of agents like chloride at early age, accelerating degrading processes. Chloride penetration is a major problem especially to infrastructure, due to seawater proximity and the use of de-icing agents. Solutions fo…
Effect of Sheep Wool Fibers on Thermal Insulation and Mechanical Properties of Cement-Based Composites
2019
The use of sheep wool as a filler of cement in order to produce mortar or plaster involves several advantages for environment and energy. Moreover, it is considered as a waste and, therefore, its use is characterized by low cost. The aim of this paper is to evaluate the influence of wool fibers on thermal conductivity and mechanical properties of cement. The samples were prepared using wool fibers, obtained from a breed of Sicilian sheep, with three different lengths (i.e., 1, 6, and 20 mm). Furthermore, in order to evaluate the influence of fiber content, the samples were prepared by varying the fiber weight fraction. The thermal conductivity of the samples was analyzed by using a heat flo…
An expeditious synthesis of spinasterol and schottenol, two phytosterols present in argan oil and in cactus pear seed oil, and evaluation of their bi…
2015
International audience; Spinasterol and schottenol, two phytosterols present in argan oil and in cactus pear seed oil, were synthesized from commercially available stigmasterol by a four steps reactions. In addition, the effects of these phytosterols on cell growth and mitochondrial activity were evaluated on 158N murine oligodendrocytes, C6 rat glioma cells, and SK-N-BE human neuronal cells with the crystal violet test and the MTT test, respectively. The effects of spinasterol and schottenol were compared with 7-ketocholesterol (71CC) and ferulic acid, which is also present in argan and cactus pear seed oil. Whatever the cells considered, dose dependent cytotoxic effects of 71CC were obser…
Color encoding for polychromatic single-channel optical pattern recognition
2010
The common multichannel system for recognizing colored images is replaced by a color-encoded single-channel system. Amethod inspired by the Munsell color system is used for encoding the different colors as phase and amplitude functions. It is shown that for many practical cases the phase information part of the color code is sufficient for obtaining good results. An implementation based on a liquid-crystal television panel that works in a phase-modulation mode is suggested. Computer simulations that demonstrate the capabilities of the suggested method are given as well as a comparison with previously published multichannel performance.
Nonlinear pattern recognition correlators based on color-encoding single-channel systems.
2004
In color pattern recognition, color channels are normally processed separately and afterward the correlation outputs are combined. This is the definition of multichannel processing. We combine a single-channel method with nonlinear filtering based on nonlinear correlations. These nonlinear correlations yield better discrimination than common matched filtering. The method codes color information as amplitude and phase distributions and is followed by correlations related to binary decompositions. The technique is based on binary decompositions of the red, green, and blue and the hue, saturation, and intensity monochromatic channels of the reference and of the input scene, after which the bin…
Electronic Structure and Bonding of Icosahedral Core–Shell Gold–Silver Nanoalloy Clusters Au144–xAgx(SR)60
2011
Atomically precise thiolate-stabilized gold nanoclusters are currently of interest for many cross-disciplinary applications in chemistry, physics and molecular biology. Very recently, synthesis and electronic properties of "nanoalloy" clusters Au_(144-x)Ag_x(SR)_60 were reported. Here, density functional theory is used for electronic structure and bonding in Au_(144-x)Ag_x(SR)_60 based on a structural model of the icosahedral Au_144(SR)_60 that features a 114-atom metal core with 60 symmetry-equivalent surface sites, and a protecting layer of 30 RSAuSR units. In the optimal configuration the 60 surface sites of the core are occupied by silver in Au_84Ag_60(SR)_60. Silver enhances the electr…