Nonlinear vibration absorbers for ropeway roller batteries control

This work investigates a nonlinear passive control strategy designed to reduce the peak accelerations in ropeway roller batteries systems by deploying an array of nonlinearly visco-elastic vibration absorbers. The control effectiveness is compared with that of an equivalent array made of linearly visco-elastic absorbers. A nonlinear parametric model describing the interactions between the different parts of this mechanical multibody system previously developed by the present authors is here extended to include the passive vibration control system aimed to mitigate the acceleration peaks induced by the vehicles transit at different operational speeds. To this aim, a set of linearly visco-elastic vibration absorbers is first optimized through the Differential Evolution (DE) algorithm seeking to minimize the area below the frequency-response curves of the linear equations of motion. Then, a new group of nonlinearly visco-elastic absorbers, that can be largely tuned (i.e., they can exhibit either softening or hardening behaviors), is proposed to mitigate the accelerations induced in the roller by the vehicle transit. These nonlinearly visco-elastic absorbers are optimized by means of the DE algorithm and comparisons with the control achieved by the linear absorbers are carried out to show the higher performance of the proposed nonlinear device. A possible design of the nonlinearly visco-elastic absorber, based on the hysteresis of a wire rope assembly undergoing flexural cycles, is also proposed and discussed

Monitoring truck's operations at freight intermodal terminals: traffic observation by scanning on-board devices

Monitoring operations at freight intermodal terminals are useful for estimating their performance, while collecting traffic data allows them to properly manage and control truck flows. Nevertheless, the key role of observation can be in contrast with users' privacy. A valuable solution to obtain traffic information preserving players' anonymity may be provided by scanning radio signals emitted by commonly used on-board devices, which can be locally identified by their unique media access control address. In this solution, no personal, freight or vehicle information is collected. An uncommon application of bluetooth scanners for monitoring operation of truck flows inside terminals is presented, based on a simple methodology for data processing. The algorithm starts from the data collection and the selection of information at relevant points of the terminal, then the network observation is composed by matching the data recorded in connected points. Finally, key performance indicators are estimated, starting from vehicle trajectories, node by node, and their travel time. The method is applied with on-field tests in a large-size rail-road terminal, where the detected counting results are lower than the ground truth, being not all the users equipped with bluetooth devices; however, the pioneering application results replicable in other contexts related to logistics

Composite material identification as micropolar continua via an optimization approach

A strategy based on material homogenization and heuristic optimization for the structural identification of composite materials is proposed. The objective is the identification of the constitutive properties of a micropolar continuum model employed to describe the mechanical behaviour of a composite material made of rigid blocks and thin elastic interfaces. The micropolar theory (Cosserat) has been proved to be capable of properly accounting for the particles arrangements as well as their size and orientation. The constitutive parameters of the composite materials, characterized by different textures and dimensions of the rigid blocks, are identified through a homogenization procedure. Thus, the identification is repeated exploiting the static or modal response of the composite materials and using the Differential Evolution algorithm. The benchmark structures assumed as target are represented by discrete models implemented in ABAQUS where the blocks and the elastic interfaces are modelled by rigid bodies and elastic interfaces, respectively. The obtained results show that proposed strategies provide accurate results paving the way to the experimental validation and in field applications

A novel, efficient synthesis of N-aryl pyrroles via reaction of 1-boronodienes with arylnitroso compounds

A one-pot hetero-Diels–Alder/ring contraction cascade is presented from the reaction of 1-boronodienes and arylnitroso derivatives to derive N-arylpyrroles in moderate to good yields (up to 82%)

Element-resolved x-ray ferrimagnetic and ferromagnetic resonance spectroscopy

We report on the measurement of element-specific magnetic resonance spectra at gigahertz frequencies using x-ray magnetic circular dichroism (XMCD). We investigate the ferrimagnetic precession of Gd and Fe ions in Gd-substituted Yttrium Iron Garnet, showing that the resonant field and linewidth of Gd precisely coincide with Fe up to the nonlinear regime of parametric excitations. The opposite sign of the Gd x-ray magnetic resonance signal with respect to Fe is consistent with dynamic antiferromagnetic alignment of the two ionic species. Further, we investigate a bilayer metal film, Ni$_{80}$Fe$_{20}$(5 nm)/Ni(50 nm), where the coupled resonance modes of Ni and Ni$_{80}$Fe$_{20}$ are separately resolved, revealing shifts in the resonance fields of individual layers but no mutual driving effects. Energy-dependent dynamic XMCD measurements are introduced, combining x-ray absorption and magnetic resonance spectroscopies.Comment: 16 pages, 8 figure

Environment and classical channels in categorical quantum mechanics

We present a both simple and comprehensive graphical calculus for quantum computing. In particular, we axiomatize the notion of an environment, which together with the earlier introduced axiomatic notion of classical structure enables us to define classical channels, quantum measurements and classical control. If we moreover adjoin the earlier introduced axiomatic notion of complementarity, we obtain sufficient structural power for constructive representation and correctness derivation of typical quantum informatic protocols.Comment: 26 pages, many pics; this third version has substantially more explanations than previous ones; Journal reference is of short 14 page version; Proceedings of the 19th EACSL Annual Conference on Computer Science Logic (CSL), Lecture Notes in Computer Science 6247, Springer-Verlag (2010

Three qubit entanglement within graphical Z/X-calculus

The compositional techniques of categorical quantum mechanics are applied to analyse 3-qubit quantum entanglement. In particular the graphical calculus of complementary observables and corresponding phases due to Duncan and one of the authors is used to construct representative members of the two genuinely tripartite SLOCC classes of 3-qubit entangled states, GHZ and W. This nicely illustrates the respectively pairwise and global tripartite entanglement found in the W- and GHZ-class states. A new concept of supplementarity allows us to characterise inhabitants of the W class within the abstract diagrammatic calculus; these method extends to more general multipartite qubit states.Comment: In Proceedings HPC 2010, arXiv:1103.226

The GHZ/W-calculus contains rational arithmetic

Graphical calculi for representing interacting quantum systems serve a number of purposes: compositionally, intuitive graphical reasoning, and a logical underpinning for automation. The power of these calculi stems from the fact that they embody generalized symmetries of the structure of quantum operations, which, for example, stretch well beyond the Choi-Jamiolkowski isomorphism. One such calculus takes the GHZ and W states as its basic generators. Here we show that this language allows one to encode standard rational calculus, with the GHZ state as multiplication, the W state as addition, the Pauli X gate as multiplicative inversion, and the Pauli Z gate as additive inversion.Comment: In Proceedings HPC 2010, arXiv:1103.226

Correlating matched-filter model for analysis and optimisation of neural networks

A new formalism is described for modelling neural networks by means of which a clear physical understanding of the network behaviour can be gained. In essence, the neural net is represented by an equivalent network of matched filters which is then analysed by standard correlation techniques. The procedure is demonstrated on the synchronous Little-Hopfield network. It is shown how the ability of this network to discriminate between stored binary, bipolar codes is optimised if the stored codes are chosen to be orthogonal. However, such a choice will not often be possible and so a new neural network architecture is proposed which enables the same discrimination to be obtained for arbitrary stored codes. The most efficient convergence of the synchronous Little-Hopfield net is obtained when the neurons are connected to themselves with a weight equal to the number of stored codes. The processing gain is presented for this case. The paper goes on to show how this modelling technique can be extended to analyse the behaviour of both hard and soft neural threshold responses and a novel time-dependent threshold response is described

Primary culture of hepatic cells from Metynnis roosevelti (Pisces, Teleostei, Characidae)

In order to achieve monolayers and adhesion in cell cultures of hepatocytes from the subtropical fish Metynnis roosevelti (Pisces, Teleostei, Characidae) three different methodologies were used: enzyme cell dissociation by means of a system containing trypsin and versene 0.25%; by means of bovine fetal serum and by the use of blood serum obtained from adult specimens of M. roosevelti. The cell medium used has been a modified F10-199 by the addition of 2 mM L-glutamine, 10 µg/mL insulin, 50 µg/mL fibronectin; and antibiotics. The best results in terms of cell dissociation as well as in terms of adhesion and confluence of the cells monolayer has been achieved by means of the enzymatic cell dissociation.A fim de obter culturas celulares e monocamada de células hepáticas do peixe subtropical Metynnis roosevelti, foram comparadas três metodologias: dissociação celular enzimática com tripsina versene 0,25%; utilização do soro fetal bovino; e soro homólogo, obtido por meio da punção da veia caudal, de exemplares adultos da mesma espécie de peixe. O meio de cultura utilizado foi F10-199 acrescido de L-glutamina 2 mM, insulina 10 µg/mL, fibronectina 50 µg/mL; e antibióticos. A dissociação celular enzimática apresentou maior eficiência na adesão e confluência da monocamada celular em comparação a outras metodologias utilizadas