High magnetic field thermal-expansion and elastic properties of CeRhIn5_5

We report high magnetic field thermal-expansion and magnetostriction results on CeRhIn$_5$ 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 $| \pm 5/2>$ 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

Synthesis and characterization of multiferroic BiMn7_7O12_{12}

We report on the high pressure synthesis of BiMn$_7$O$_{12}$, a manganite displaying a "quadruple perovskite" structure. Structural characterization of single crystal samples shows a distorted and asymmetrical coordination around the Bi atom, due to presence of the $6s^{2}$ lone pair, resulting in non-centrosymmetric space group Im, leading to a permanent electrical dipole moment and ferroelectric properties. On the other hand, magnetic characterization reveals antiferromagnetic transitions, in agreement with the isostructural compounds, thus evidencing two intrinsic properties that make BiMn$_7$O$_{12}$ a promising multiferroic material.Comment: 4 pages, 3 figure

Construction Stage Analysis for a New Mixed Structure Building in Milan

In this study the Construction Stage Analysis (CSA) of a new mixed structure building is discussed in order to identify the best timing and execution activities scheduling. The building is part of a new university campus that will be realized close to the center of the city. The CSA is carried out by the implementation of two models: the finite element model for the structural analyses and the BIM model for controlling the sequence of the construction phases. Once fixed the structural model, in the preliminary design phase, different sequences are analyzed in order to optimize the construction management in terms of timing and costs. Moreover, the optimization of the construction phases is set by considering the creep and shrinkage of the concrete material

Improving the TB case management: The International Standards for Tuberculosis Care.

Tuberculosis (TB) is currently the leading cause of death from a curable infectious disease. The World Health Organization (WHO) estimates that 8.9 million new TB cases occurred in 2004 (of which 3.9 million were sputum smear positive), although only about half of the estimated number were reported by public health systems. Whilst the highest TB incidence rate is in sub-Saharan Africa (estimated to be 356 new cases per 100,000 population per yr), in most countries of the former Soviet Union the estimated incidence rate exceeds 100 new cases per 100,000 population per yr. Although the rate of increase in the TB incidence rate is decreasing, the global TB notification grew by 1% between 2003 and 2004, the last year for which data are available. This continued increase is largely the result of the striking increase in cases in sub-Saharan Africa and, to a lesser extent, in the former USSR. Whilst the worsening of the TB incidence in Africa is due to the HIVepidemic compounded by an insufficient health infrastructure, it is due to different causes in Eastern Europe, including economic decline, increased poverty, social disruption and sub-standard health services. In addition, as a result of these factors, .10% of new TB cases in the Baltic states and in some parts of Russia are multidrug-resistant (MDR-TB), i.e. resistant to at least isoniazid and rifampicin. In the European region, 445,000 new TB cases and nearly 70,000 deaths were estimated to have resulted from TB in 2004. In the Eastern part of the region, the levels of directly observed treatment, short-course (DOTS) strategy coverage and case detection are the lowest among the world regions, and the overall treatment success rate is the second lowest (75%) after Africa

Young but fading radio sources: searching for remnants among compact steep-spectrum radio sources

The incidence of young but fading radio sources provides important information on the life cycle of radio emission in radio-loud active galactic nuclei. Despite its importance for constraining the models of radio source evolution, there are no systematic studies of remnants in complete samples of young radio sources. We report results on the study of 18 compact steep-spectrum (CSS) radio sources, selected from the statistically complete B3-VLA CSS sample, characterized by a steep optically-thin spectrum (alpha > 1.0) and no core detection in earlier studies. Our deep multi-frequency Very Large Array (VLA), pc-scale Very Long Baseline Array (VLBA), and eMERLIN observations allowed us to locate the core component in 10 objects. In 3 CSS sources there is no clear evidence of present-time active regions, suggesting they are likely in a remnant phase. Among sources with core detection, we find 3 objects that have no clear active regions (hotspots) at the edges of the radio structure, suggesting that the radio emission may have just restarted. Our results support a power-law distribution of the source ages, although the poor statistics prevents us from setting solid constraints on the percentage of remnants and restarted sources in sub-populations of radio sources.Comment: 33 pages, 8 figures, 7 tables. Accepted for publication in MNRA

Elastic and thermodynamic properties of the shape-memory alloy AuZn

The current work reports on the elastic shear moduli, internal friction, and the specific heat of the B2 cubic ordered alloy AuZn as a function of temperature. Measurements were made on single-crystal and polycrystalline samples using Resonant Ultrasound Spectroscopy (RUS), semi-adiabatic calorimetry and stress-strain measurements. Our results confirm that this alloy exhibits the shape-memory effect and a phase transition at 64.75 K that appears to be continuous (second-order) from the specific heat data. It is argued that the combination of equiatomic composition and a low transformation temperature constrain the chemical potential and its derivatives to exhibit behavior that lies at the borderline between that of a first-order (discontinuous) and a continuous phase transition. The acoustic dissipation does not peak at the transtion temperature as expected, but shows a maximum well into the low-temperature phase. The Debye temeprature value of 219 K, obtained from the low-temperature specific heat data is in favorable agreement with that determined from the acoustic data (207 K) above the transition.Comment: 25 pages, 6 figures, submitted to Phys. Rev.