Search results for "Ferro"
showing 10 items of 2451 documents
A New Valence Tautomerism Example in an Electroactive Ferrocene Substituted Triphenylmethyl Radical
2003
A new molecular system combining an open-shell organic radical that acts as an acceptor group, different from an o-quinone moiety, covalently linked to a ferrocene moiety, acting as the donor group, is shown to exhibit valence tautomerism.
Biferrocene Amino Acid, a Ferrocenylogoue of Ferrocene Amino Acid: Synthesis, Cross-Linking, and Redox Chemistry
2010
Access of the novel biferrocene amino acid 7 is provided by two different routes, namely, via desymmetrization of a biferrocene and via palladium-catalyzed cross-coupling of two substituted ferrocenes. The dissymmetric biferrocene 7 is head−head coupled to ureylene-bridged bis(biferrocene) 9 and also head−tail coupled to amide-bridged bis(biferrocene) 14. The monomer 7 and the dimers 9 and 14 are oxidized to mixed-valent cations 7+, 9+, 92+, and 142+. The valencies are trapped in the solid state as shown by Mossbauer and EPR spectroscopy and by X-ray diffraction analysis of [7](I3). Paramagnetic NMR shift studies (7 → 7+) suggest that the hole is localized at the N-substituted ferrocene uni…
Road Functional Classification Using Pattern Recognition Techniques
2019
The existing international standards suggest a methodology to assign a specific functional class to a road, by the values of some features, both geometrical and use-related. Sometimes, these characteristics are in contrast with each other and direct the analyst towards conflicting classes for a road or, worse, one or more of these features vary heterogeneously along the road. In these conditions, the analyst assigns the class that, by his capability and experience, he retains the most appropriate, in a very subjective way. On the contrary, the definition of an automatic procedure assuring an objective identification of the most appropriate functional class for each road would be desirable. …
EFFETTI DINAMICI DELL’INNALZAMENTO DEL CARICO PER ASSE DI ROTABILI FERROVIARI PER TRASPORTO MERCI
2011
Lo sviluppo di un sistema di trasporto ferroviario merci richiede di minimizzare i tempi di percorrenza e massimizzare la capacità di carico dei convogli. Questo obiettivo può essere raggiunto mediante tre diverse strategie, che possono essere adottate separatamente o in modo congiunto. Le strategie consistono sostanzialmente nell’aumento della capacità di carico del singolo carro, nell’aumento della lunghezza del convoglio e nell’aumento della velocità del veicolo. La possibilità di attuare simultaneamente le tre strategie è possibile solo disponendo di infrastrutture dedicate e utilizzando una progettazione specifica della linea e dei veicoli. Il lavoro illustra gli effetti di un innalzam…
THE DESIGN OF WAITING AREAS TO OPTIMIZE THE STORAGE CAPACITY IN THE MARINE INTERMODAL TERMINALS
2009
The appropriate sizing of storage areas to optimize the management of intermodal transport, the adoption of environment protection systems and the appropriate flow’s regulations inside manoeuvre’s zones can solve many problems encountered today in a intermodal marine terminal. For these reasons the “integrated design” of storage areas for vehicles and containers is considered essential to ensure efficiency and functionality for all harbour-system. So is here proposed a simulative model as a tool for a more correct design of waiting areas by considering the real stochastic conditions of the process of the arrivals. For the sizing of areas for containers in the harbours, it is necessary to re…
Improvement of high modulus asphalt mixtures with average quality aggregate and bitumen by application of polymeric additives
2018
Abstract The paper deals with the development of asphalt mixtures for high performing binder and base courses, modified with both commercial and waste polymeric additives, via dry process. The focus was on the mix design of high performing mixtures making use of average quality aggregate and average penetration grade bitumen (as locally available) instead of the usually required high quality components, manly very hard bitumen, thus aiming to improve the reference mixture as made possible by suitable polymers. Mixtures were subjected not only to conventional tests for mix design purposes, but also to advanced tests for performance evaluation such as rutting resistance and fatigue resistance…
Rotationally symmetric 1-harmonic flows from D2 TO S 2: Local well-posedness and finite time blowup
2010
The 1-harmonic flow from the disk to the sphere with constant Dirichlet boundary conditions is analyzed in the case of rotational symmetry. Sufficient conditions on the initial datum are given, such that a unique classical solution exists for short times. Also, a sharp criterion on the boundary condition is identified, such that any classical solution will blow up in finite time. Finally, nongeneric examples of finite time blowup are exhibited for any boundary condition.
Magnetorheology for suspensions of solid particles dispersed in ferrofluids
2006
In this work, the magnetorheological properties of suspensions of micron-sized iron particles dispersed in magnetite ferrofluids were studied. With this aim, the flow properties of the suspensions in the steady-state regime were investigated using a commercial magnetorheometer with a parallel-plate measuring cell. The effect of both magnetite and iron concentration on the magnitude of the yield stress was studied for a broad range of magnetic fields. In addition, the experimental values of the yield stress were compared with the predictions from the chain model. With this purpose the values of the yield stress were obtained by means of finite element calculations. Interestingly, it was foun…
Ferromagnetic kinetic exchange interaction in magnetic insulators
2020
The superexchange theory predicts dominant antiferromagnetic kinetic interaction when the orbitals accommodating magnetic electrons are covalently bonded through diamagnetic bridging atoms/groups. Here we show that explicit consideration of magnetic and (leading) bridging orbitals, together with the electron transfer between the former, reveals a strong ferromagnetic kinetic exchange contribution. First principle calculations show that it is comparable in strength with antiferromagnetic superexchange in a number of magnetic materials with diamagnetic metal bridges. In particular, it is responsible for a very large ferromagnetic coupling ($-10$ meV) between the iron ions in a Fe$^{3+}$-Co$^{…
Spin and charge currents driven by the Higgs mode in high-field superconductors
2020
The Higgs mode in superconducting materials describes slowly decaying oscillations of the order parameter amplitude. We demonstrate that in superconductors with a built-in spin-splitting field the Higgs mode is strongly coupled to the spin degrees of freedom, allowing for the generation of time-dependent spin currents. Converting such spin currents to electric signals by spin-filtering elements provides a tool for the second-harmonic generation and the electrical detection of the Higgs mode generated by the external irradiation. The nonadiabatic spin torques generated by these spin currents allow for the magnetic detection of the Higgs mode by measuring the precession of the magnetic moment…