1,016 research outputs found
High magnetic field thermal-expansion and elastic properties of CeRhIn
We report high magnetic field thermal-expansion and magnetostriction results
on CeRhIn single crystals. Several transitions, both first and second
order, are observed when the field is applied perpendicular to the
crystallographic c-axis. The magnetic field dependence of the thermal-expansion
coefficient above 15 K, where the magnetic correlations are negligible, can be
explained supposing an almost pure ground state doublet, in
apparent contradiction with neutron scattering experiments. Although the
spin-lattice interaction is relevant in this compound, the effect of the
magnetic correlations on the elastic properties is relatively weak, as revealed
by resonant ultrasound spectroscopy experiments.Comment: 5 pages, 6 figure
Folds and Buckles at the Nanoscale: Experimental and Theoretical Investigation of the Bending Properties of Graphene Membranes
The elastic properties of graphene crystals have been extensively investigated, revealing unique properties in the linear and nonlinear regimes, when the membranes are under either stretching or bending loading conditions. Nevertheless less knowledge has been developed so far on folded graphene membranes and ribbons. It has been recently suggested that fold-induced curvatures, without in-plane strain, can affect the local chemical reactivity, the mechanical properties, and the electron transfer in graphene membranes. This intriguing perspective envisages a materials-by-design approach through the engineering of folding and bending to develop enhanced nano-resonators or nano-electro-mechanical devices. Here we present a novel methodology to investigate the mechanical properties of folded and wrinkled graphene crystals, combining transmission electron microscopy mapping of 3D curvatures and theoretical modeling based on continuum elasticity theory and tight-binding atomistic simulations
Argument structure, alignment and auxiliaries between Latin and Romance. A diachronic syntactic account
Although Latin displays many characteristics of nominative/accusative alignment, it also exhibits a number of properties that are typical of active/inactive linguistic systems. More specifically, the Latin verbal clause displays an active/inactive distinction, as it regularly marks, through the occurrence of dedicated morphological strategies, the presence of non-agentive as opposed to agentive contexts.
This dissertation explores the syntactic motivations behind this opposition, addressing the crucial question about the relationship between syntax and morphology. The claim is made that verbal morphology in Latin is always syntactically motivated, since it directly reflects the difference between active and inactive structures. In particular, deponent verbs are shown not to be a case of syntax-morphology mismatch: these verbs exhibit inactive morphology because of their non-agentive properties. Moreover, it will be argued that syntax and semantics are closely related to each other within the syntactic computation.
From this perspective, this thesis also provides an account of the development of a number of analytic constructions in Romance: perfective, possessive and deontic periphrases. Substantial attention is devoted to the diachronic study of the Romance auxiliation patterns occurring in these constructions and to their relationship with alignment and argument structure. The main claim is that the Romance outcomes of these periphrases are closely related to the active/inactive opposition characterizing the Latin system and to the alignment changes that characterized the passage from Latin to Romance. Therefore, these developments cannot be seen as isolated phenomena, but must be understood as the various manifestations of a systematic change affecting the whole linguistic system. Finally, the analysis and investigation of these diachronic facts confirms that syntactic reanalysis is one of the major forces at the basis of language change.
This study will be of relevance to anyone interested in diachronic syntax, historical linguistics, classical philology and Italian dialectology.Theoretical and Experimental Linguistic
Predicting the effect of improved socioeconomic health determinants on the tuberculosis epidemic
Two important public health documents have recently established programmatic goals for tuberculosis control. The first is WHO's End TB Strategy, which represents the evolution of previous DOTS (directly observed treatment, short-course) and Stop TB strategies.1 End TB is built around three pillars: pillar 1 focuses on diagnosis, treatment, and prevention; pillar 2 on ways to tackle socioeconomic factors (eg, poverty reduction, social protection, and universal access); and pillar 3 on scientific research
AFS Pool Account Users - GSSKLOG and LCMAPS extension to support AFS users as EGEE pool account users
This paper describes the extensions to the gssklog and lcmaps packages that make possible the utilization of AFS users as LCMAPS/VOMS pool account users. This work has been performed in the framework of the integration of ENEA-GRID and EGEE infrastructure
Remotely Readable Fiber Optic Compass
PatentA remotely readable fiber optic compass. A sheet polarizer
is affixed to a magnet rotatably mounted in a compass
body, such that the polarizer rotates with the magnet.
The optical axis of the sheet polarizer is preferably
aligned with the north-south axis of the magnet. A single
excitation light beam is divided into four identical
beams, two of which are passed through the sheet polarizer
and through two fixed polarizing sheets which have
their optical axes at right angles to one another. The
angle of the compass magnet with respect to a fixed axis
of the compass body can be determined by measuring
the ratio of the intensities of the two light beams. The
remaining ambiguity as to which of the four possible
quadrants the magnet is pointing to is resolved by the
second pair of light beams, which are passed through
the sheet polarizer at positions which are transected by
two semicircular opaque strips formed on the sheet
polarizer. The incoming excitation beam and the four
return beams are communicated by means of optical
fibers, giving a remotely readable compass which has
no electrical parts
One-step synthesis of metal/oxide nanocomposites by gas phase condensation
Metallic nanoparticles (NPs), either supported on a porous oxide framework or finely dispersed within an oxide matrix, find applications in catalysis, plasmonics, nanomagnetism and energy conversion, among others. The development of synthetic routes that enable to control the morphology, chemical composition, crystal structure and mutual interaction of metallic and oxide phases is necessary in order to tailor the properties of this class of nanomaterials. With this work, we aim at developing a novel method for the synthesis of metal/oxide nanocomposites based on the assembly of NPs formed by gas phase condensation of metal vapors in a He/O2 atmosphere. This new approach relies on the independent evaporation of two metallic precursors with strongly different oxidation enthalpies. Our goal is to show that the precursor with less negative enthalpy gives birth to metallic NPs, while the other to oxide NPs. The selected case study for this work is the synthesis of a Fe-Co/TiOx nanocomposite, a system of great interest for its catalytic and magnetic properties. By exploiting the new concept, we achieve the desired target, i.e., a nanoscale dispersion of metallic alloy NPs within titanium oxide NPs, the structure of which can be tailored into TiO1-\u3b4 or TiO2 by controlling the synthesis and processing atmosphere. The proposed synthesis technique is versatile and scalable for the production of many NPs-assembled metal/oxide nanocomposites
Improving tuberculosis surveillance in Europe is key to controlling the disease.
As underlined by the joint ECDC and World Health Organization Regional Office for Europe TB report, launched on 18 March the importance of good surveillance to stem this trend cannot be underestimated.
Where do we go with surveillance in Europe? Can we do more? How many MDR and XDR TB cases occur because of sub-optimal patient management?
This issue of Eurosurveillance casts light on these important questions with four interesting articles.
The results of the studies reported in this issue of Eurosurveillance allow us to point out some key topics:
\u2022The completeness of reporting information (including treatment outcomes), the proportion of culture-confirmed TB cases reported as well as the proportion of strains on which DST for both first- and second-line drugs is performed and reported are still sub-optimal overall in Europe. The relevance of these pitfalls goes beyond the \u201csimple\u201d surveillance limitation, having the potential to affect other important TB control pillars, e.g. infection control and case-management.
\u2022MDR and XDR TB still persist in Europe. The high proportion of MDR TB identified among new TB cases reported by certain countries indicates that sub-optimal infection control practices are likely to occur, while the high percentage of MDR TB notified among retreatment cases is probably the result of sub-optimal case management in the past decade
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