EXAFS Investigations of the Local Thermal Properties of Solids

A thorough understanding of the e!ects of thermal disorder on EXAFS is important for two orders of reasons: it allows one to increase the accuracy of the structural parameters obtained from EXAFS analysis and it gives original insights on the local dynamical properties of m

Project E

On Art Art, in its broadest sense, includes all human activities - carried out individually or collectively - that leads to creative forms of aesthetic expression, relying on technical, innate abilities and behavioural rules derived from study and experience. At its today’s art is closely related to the ability to convey emotion, so the artistic expressions, while aiming to transmit “messages”, not a real language, as it does not have a clear code shared between all users, but instead are interpreted subjectively. [ http://it.wikipedia.org/wiki/Arte ] On Design In a larger sense for design means all stages of planning and scheduling of a set of activities that will lead to an expected result, which can be achieved in a total, partial or even be missed. Ultimately therefore almost all human activities occur, more or less effectively, to a design that means, strategies and actions necessary to achieve certain targets Nowadays the English word Design includes both aesthetic and technical aspects of industrial design. [ http://it.wikipedia.org/wiki/Disegno_industriale ] Almost by definition the function of Art is to create an emotional reaction departing from an individual perception of events, culture, identity. And that’s imply that the function of Art can be philosophical, as well as political or social. In the contrary the function of an Industrial designed objects is mostly practical and aim to achieve an artefact that “works”. In my research I would like to attempt a product that contains both artistic and Design qualities in symbiosis with each other starting from a no functional input. Where is the border in between artistic expression and practical function? How can I express both qualities in one object? What if a product also contains features that are not necessarily related to its prime function but encourage a different perspective , a no precise function that can be used subjectively? The starting point will be an existing project called Embrace. Embrace is a lounge chair that attempted to explore those questions without fully investigating them. In fact Embrace has many inconsistencies that make the project incomplete and undefined. Those conditions are ideal to test my new research questions . The idea is to take this early project and go backward in through its designing process and try to enhance the already existing inner qualities but also add external inputs. Eventually Embrace will be considered a new project and its function and meanings should be improved and/or modified. Embrace will became project EMaster i produktdesig

H2/H∞ output information-based disturbance attenuation for differential linear repetitive processes

Repetitive processes propagate information in two independent directions where the duration of one is finite. They pose control problems that cannot be solved by application of results for other classes of 2D systems. This paper develops controller design algorithms for differential linear processes, where information in one direction is governed by a matrix differential equation and in the other by a matrix discrete equation, in an H2/H∞ setting. The objectives are stabilization and disturbance attenuation, and the controller used is actuated by the process output and hence the use of a state observer is avoided

Directed graphs, 2D state models, and characteristic polynomials of irreducible matrix pairs

AbstractThe definition and main properties of a 2D digraph, namely a directed graph with two kinds of arcs, are introduced. Under the assumption of strong connectedness, the analysis of its paths and cycles is performed, based on an integer matrix whose rows represent the compositions of all circuits, and on the corresponding row module. Natural constraints on the composition of the paths connecting each pair of vertices lead to the definition of a 2D strongly connected digraph. For a 2D digraph of this kind the set of vertices can be partitioned into disjoint 2D-imprimitivity classes, whose number and composition are strictly related to the structure of the row module. Irreducible matrix pairs, i.e. pairs endowed with a 2D strongly connected digraph, are subsequently discussed. Equivalent descriptions of irreducibility, naturally extending those available for a single irreducible matrix, are obtained. These refer to the free evolution of the 2D state models described by the pairs and to their characteristic polynomials. Finally, primitivity is viewed as a special case of irreducibility, and completely characterized in terms of 2D-digraphs, characteristic polynomials, and 2D system dynamics

2D systems feedback compensation: an approach based on commutative linear transformations

AbstractAlgebraic properties of a pair of commutative matrices associated with an ideal in R[z1, z2] are exploited for characterizing the closed loop polynomial variety of a 2D system. Also algorithms are given to find under what constraints the closed loop variety can be assigned and to compute the MFD of a compensator

An XMM-Newton and NuSTAR study of IGR J18214-1318: a non-pulsating high-mass X-ray binary with a neutron star

IGR J18214-1318, a Galactic source discovered by the International Gamma-Ray Astrophysics Laboratory, is a high-mass X-ray binary (HMXB) with a supergiant O-type stellar donor. We report on the XMM-Newton and NuSTAR observations that were undertaken to determine the nature of the compact object in this system. This source exhibits high levels of aperiodic variability, but no periodic pulsations are detected with a 90% confidence upper limit of 2% fractional rms between 0.00003-88 Hz, a frequency range that includes the typical pulse periods of neutron stars (NSs) in HMXBs (0.1-10$^3$ s). Although the lack of pulsations prevents us from definitively identifying the compact object in IGR J18214-1318, the presence of an exponential cutoff with e-folding energy $\lesssim30$ keV in its 0.3-79 keV spectrum strongly suggests that the compact object is an NS. The X-ray spectrum also shows a Fe K$\alpha$ emission line and a soft excess, which can be accounted for by either a partial-covering absorber with $N_{\mathrm{H}}\approx10^{23}$ cm$^{-2}$ which could be due to the inhomogeneous supergiant wind, or a blackbody component with $kT=1.74^{+0.04}_{-0.05}$ keV and $R_{BB}\approx0.3$ km, which may originate from NS hot spots. Although neither explanation for the soft excess can be excluded, the former is more consistent with the properties observed in other supergiant HMXBs. We compare IGR J18214-1318 to other HMXBs that lack pulsations or have long pulsation periods beyond the range covered by our observations.Comment: 15 pages, 12 figures, 4 table