872 research outputs found
Employing photoluminescence to rapidly follow aggregation and dispersion of cellulose nanofibrils
Venture Capital and Business Angels and the Creation of Innovative Firms in Poland
The article also points out that conditions fostering further development of the described types of entrepreneurship and innovation financing and a dynamic environment generating innovative capacity should be created.W artykule zasygnalizowano również potrzebę kreowania uwarunkowań sprzyjających rozwojowi opisanych form finansowania przedsiębiorczości, innowacyjności i dynamicznego otoczenia generującego zdolności innowacyjne
Energy efficiency considerations in integrated IT and optical network resilient infrastructures
The European Integrated Project GEYSERS - Generalised Architecture for Dynamic Infrastructure Services - is concentrating on infrastructures incorporating integrated optical network and IT resources in support of the Future Internet with special emphasis on cloud computing. More specifically GEYSERS proposes the concept of Virtual Infrastructures over one or more interconnected Physical Infrastructures comprising both network and IT resources. Taking into consideration the energy consumption levels associated with the ICT today and the expansion of the Internet in size and complexity, that incurring increased energy consumption of both IT and network resources, energy efficient infrastructure design becomes critical. To address this need, in the framework of GEYSERS, we propose energy efficient design of infrastructures incorporating integrated optical network and IT resources, supporting resilient end-to-end services. Our modeling results quantify significant energy savings of the proposed solution by jointly optimizing the allocation of both network and IT resources
The use of information and communication technologies in family support across Europe:A narrative review
Influence of severe plastic deformation on the precipitation hardening of a FeSiTi steel
The combined strengthening effects of grain refinement and high precipitated
volume fraction (~6at.%) on the mechanical properties of FeSiTi alloy subjected
to SPD processing prior to aging treatment were investigated by atom probe
tomography and scanning transmission electron microscopy. It was shown that the
refinement of the microstructure affects the precipitation kinetics and the
spatial distribution of the secondary hardening intermetallic phase, which was
observed to nucleate heterogeneously on dislocations and sub-grain boundaries.
It was revealed that alloys successively subjected to these two strengthening
mechanisms exhibit a lower increase in mechanical strength than a simple
estimation based on the summation of the two individual strengthening
mechanisms
Immobilization of chromium complexes in zeolite Y obtained from biosorbents : synthesis, characterization and catalytic behaviour
The goal of this study is the preparation of new heterogeneous catalytic materials to be used in oxidation reactions under mild conditions through the valuation of heavy metals in wastewater. The samples used in the immobilization of chromium complexes were prepared from a dichromate solution of 100 mgCr L−1. The zeolite CrNaY was prepared from a robust biosorption system consisting of a bacterial biofilm, Arthrobacter viscosus, supported on zeolite NaY. The biofilm performs the reduction of Cr(VI) to Cr(III) and this cation is retained in the zeolite by ion exchange. The immobilization of chromium complexes with heterocyclic ligands in the supercages of Y zeolite was performed by the in situ synthesis with three different ligands, 3-methoxy-6-chloropyridazine (A), 3-piperidino-6-chloropyridazine (B) and 1-(2-pyridylazo)-2-naphthol (C). A sample loaded with Cr from a liquid solution with the same initial concentration was prepared as a reference through the traditional direct ion-exchange method and coordinated with ligand (A). The resulting catalysts were fully characterized by different techniques (FTIR, XRD, TGA, SEM, Raman, cyclic voltammetric studies and chemical analysis) and the results confirmed that the Cr complexes were immobilized in supercages of NaY. Catalytic studies were performed in liquid phase for the cyclohexene oxidation, at 40 °C, using tert-butyl hydroperoxide (TBHP) as the oxidizing agent. All the prepared catalysts exhibited catalytic activity for the oxidation reaction.União Europeia. Fundo Europeu de Desenvolvimento Regional (FEDER)Fundação para a Ciência e a Tecnologia (FCT) - ref. POCTI/44449/CTA/2002, POCTI-SFA-3-68
Dynamics and Critical Behaviour of the q-model
The -model, a random walk model rich in behaviour and applications, is
investigated. We introduce and motivate the -model via its application
proposed by Coppersmith {\em et al.} to the flow of stress through granular
matter at rest. For a special value of its parameters the -model has a
critical point that we analyse. To characterise the critical point we imagine
that a uniform load has been applied to the top of the granular medium and we
study the evolution with depth of fluctuations in the distribution of load.
Close to the critical point explicit calculation reveals that the evolution of
load exhibits scaling behaviour analogous to thermodynamic critical phenomena.
The critical behaviour is remarkably tractable: the harvest of analytic results
includes scaling functions that describe the evolution of the variance of the
load distribution close to the critical point and of the entire load
distribution right at the critical point, values of the associated critical
exponents, and determination of the upper critical dimension. These results are
of intrinsic interest as a tractable example of a random critical point. Of the
many applications of the q-model, the critical behaviour is particularly
relevant to network models of river basins, as we briefly discuss. Finally we
discuss circumstances under which quantum network models that describe the
surface electronic states of a quantum Hall multilayer can be mapped onto the
classical -model. For mesoscopic multilayers of finite circumference the
mapping fails; instead a mapping to a ferromagnetic supersymmetric spin chain
has proved fruitful. We discuss aspects of the superspin mapping and give a new
elementary derivation of it making use of operator rather than functional
methods.Comment: 34 pages, Revtex, typo correcte
- …