135 research outputs found

    Keeping it modern, making it sustainable. Monitoring and energy retrofitting the Urbino University Colleges

    Get PDF
    This paper presents a research to balance building conservation, users’ comfort and energy efficiency of a masterpiece of XX century architecture. The Urbino University Colleges were designed by architect Giancarlo de Carlo and built since 1962 to 1983 beside the Renaissance city. They host more than 1,000 students within 5 dormitories and 62,000 m2 surface. Authors discuss some outcomes from the “Keeping it modern” research program financed by the Getty Foundation in 2016, which aims at providing the Colleges with a sustainable conservation plan. The goal is to lower heating and operational costs to allow funds in conservation activities. Specific issues regard: the striking dimensions of the complex, the constructive features (brickwork walls, exposed concrete structures, single-glazed windows) and the lack of data about the hygrothermal performances. The research thus includes a hygrothermal analysis, a proposal for the energy retrofitting, a building-HVAC model, a test on a pilot site. Authors have monitored surface temperatures, indoor air temperature and humidity for one year, even mapping their distribution through a digital psychrometer. Thermal imaging has been used to detect heat losses, thermal bridges and heat gains due to the solar radiation. Data have fed a building-HVAC model, which was a reference to design an appropriate strategy for retrofitting and improving the energy efficiency of the complex. Some solutions are being implemented on a pilot site. The building performances before and after retrofitting are compared. Results provide indications to merge conservation and sustainability of a XX century heritage building. In conclusion, the solid knowledge of each case confirms being required to support a retrofit proposal of a heritage building, moreover in case of a XX century building, as the cultural value of such a huge heritage is often disregarded to improve its energy performance

    HOST STATUS OF PLANT SPECIES WITH NEMATICIDAL ACTIVITY AGAINST MELOIDOGYNE GRAMINICOLA (GOLDEN & BIRCHFIELD)

    Get PDF
    The rice root-knot nematode, Meloidogyne graminicola (Golden & Birchfield), is a nematode first described in 1965 from grasses and oats in Louisiana (US), and currently spread in rice crops in Asia, parts of the Americas and Africa. It can be detected in a wide range of more than 98 host plant species. In 2016 M. graminicola was detected for the first time in some rice fields of Northern Italy. In this paper, two greenhouse experiments (the first at 21-22 °C and the second one at 26-28 °C) are reported and discussed, in which three species containing bioactive compounds, Lepidium campestre (L.) R. Br., Eruca sativa Mill. cv. Nemat, and Crotalaria juncea L., were compared with Cucumis sativus L., a good host of M. graminicola, as control. Seedlings of each plant species were transplanted in pots containing mean 50 J2s 100 cm−3 soil. Three assessments were carried out about 30, 60, 90 days after transplantation, on both soil and roots. Temperature influenced M. graminicola life cycle, which was never completed at 21-22 °C; conversely, at 26-28 °C, both E. sativa and C. juncea reached a reproduction rate (R) = 0.01, confirming to be poor hosts, effective in decreasing the nematode infestation on the roots and in the soil, while L. campestre (R = 4.01) demonstrated to be a good host of M. graminicola more than the control C. sativus (R = 2.12), increasing considerably the nematode population after about 90 days

    Photocatalytic activity of nanotubular TiO2films obtained by anodic oxidation: A comparison in gas and liquid phase

    Get PDF
    The availability of immobilized nanostructured photocatalysts is of great importance in the purification of both polluted air and liquids (e.g., industrial wastewaters). Metal-supported titanium dioxide films with nanotubular morphology and good photocatalytic efficiency in both environments can be produced by anodic oxidation, which avoids release of nanoscale materials in the environment. Here we evaluate the effect of different anodizing procedures on the photocatalytic activity of TiO2nanostructures in gas and liquid phases, in order to identify the most efficient and robust technique for the production of TiO2layers with different morphologies and high photocatalytic activity in both phases. Rhodamine B and toluene were used as model pollutants in the two media, respectively. It was found that the role of the anodizing electrolyte is particularly crucial, as it provides substantial differences in the oxide specific surface area: nanotubular structures show remarkably different activities, especially in gas phase degradation reactions, and within nanotubular structures, those produced by organic electrolytes lead to better photocatalytic activity in both conditions tested

    Multi-wavelength observations of 1RXH J173523.7-354013: revealing an unusual bursting neutron star

    Get PDF
    On 2008 May 14, the Burst Alert Telescope aboard the Swift mission triggered on a type-I X-ray burst from the previously unclassified ROSAT object 1RXH J173523.7-354013, establishing the source as a neutron star X-ray binary. We report on X-ray, optical and near-infrared observations of this system. The X-ray burst had a duration of ~2 h and belongs to the class of rare, intermediately long type-I X-ray bursts. From the bolometric peak flux of ~3.5E-8 erg/cm^2/s, we infer a source distance of D<9.5 kpc. Photometry of the field reveals an optical counterpart that declined from R=15.9 during the X-ray burst to R=18.9 thereafter. Analysis of post-burst Swift/XRT observations, as well as archival XMM-Newton and ROSAT data suggests that the system is persistent at a 0.5-10 keV luminosity of ~2E35 (D/9.5 kpc)^2 erg/s. Optical and infrared photometry together with the detection of a narrow Halpha emission line (FWHM=292+/-9 km/s, EW=-9.0+/-0.4 Angstrom) in the optical spectrum confirms that 1RXH J173523.7-354013 is a neutron star low-mass X-ray binary. The Halpha emission demonstrates that the donor star is hydrogen-rich, which effectively rules out that this system is an ultra-compact X-ray binary.Comment: Accepted for publication in MNRAS, 13 pages, 6 figures, 5 table

    The Optical Polarisation of the Vela Pulsar revisited

    Full text link
    In this work we present a revised measurement of the phase-averaged optical polarisation of the Vela pulsar (PSR B0833-45), for which only one value has been published so far (Wagner & Seifert 2000). Our measurement has been obtained through an accurate reanalysis of archival polarisation observations obtained with the FORS instrument at the VLT. We have measured a phase-averaged linear polarisation degree P=9.4% +/- 4% and a position angle 146 +/- 11 deg, very close to the ones of the axis of symmetry of the X-ray arcs and jets detected by Chandra and of the pulsar proper motion.We have compared the measured phase-averaged optical polarisation with the expectations of different pulsars' magnetosphere models. We have found that all models consistently predict too large values of the phase-averaged linear polarization with respect to the observed one. This is probably a consequence of present models' limitations which neglect the contributions of various depolarisation effects. Interestingly, for the outer gap model we have found that, assuming synchrotron radiation for the optical emission, the observed polarisation position angle also implies an alignment between the pulsar rotational axis and the axis of symmetry of the X-ray arcs and jets.Comment: 8 pages, 4 figure

    A Combined Raman Spectroscopy and Atomic Force Microscopy System for In Situ and Real-Time Measures in Electrochemical Cells

    Get PDF
    : An innovative and versatile set-up for in situ and real time measures in an electrochemical cell is described. An original coupling between micro-Raman spectroscopy and atomic force microscopy enables one to collect data on opaque electrodes. This system allows for the correlation of topographic images with chemical maps during the charge exchange occurring in oxidation/reduction processes. The proposed set-up plays a crucial role when reactions, both reversible and non-reversible, are studied step by step during electrochemical reactions and/or when local chemical analysis is required

    Residual tumor micro-foci and overwhelming regulatory T lymphocyte infiltration are the causes of bladder cancer recurrence

    Get PDF
    Bladder cancer has an unexplained, high recurrence rate. Causes of recurrence might include the presence of sporadic tumor micro-foci in the residual urothelial tissue after surgery associated with an inverted ratio between intratumoral effector and regulatory T cell subsets. Hence, surgical specimens of both tumors and autologous, macroscopically/histologically free-of-tumor tissues were collected from 28 and 20 patients affected by bladder or renal cancer, respectively. The frequencies of effector (IFN?+ and IL17+ T cells) and regulatory (CD4+CD25hiCD127lo and CD8+CD28-CD127loCD39+ Treg) T cell subpopulations among tumor infiltrating lymphocytes were analyzed by immunofluorescence, while the gene expression of MAGE-A1 and MAGE-A2 tumor-associated antigens was studied by RT-PCR. The results show that both the T cell infiltrate and the frequency of MAGE-A1/A2 gene expression were comparable in tumors and in autologous free-of-tumor tissues in bladder cancer, while the autologous free-of-tumor renal tissues showed reduced T cell infiltrate and frequency of MAGE gene expression as compared to the autologous tumors. Importantly, the intra-tumor T effector/Treg cell ratio was consistently &lt;1 in bladder cancer patients (n. 7) who relapsed within two years, while it was always &gt;1 in patients (n. 6) without recurrence (regardless of tumor stage) (P = 0.0006, Odds ratio = 195). These unprecedented findings clarify the pathogenic mechanism of bladder cancer recurrence and suggest that microscopically undetectable micro-foci of tumor may predispose to recurrence when associated with an inverted intratumoral T effector/Treg cell ratio

    Digital volume correlation can be used to estimate local strains in natural and augmented vertebrae: An organ-level study

    Get PDF
    Digital Volume Correlation (DVC) has become popular for measuring the strain distribution inside bone structures. A number of methodological questions are still open: the reliability of DVC to investigate augmented bone tissue, the variability of the errors between different specimens of the same type, the distribution of measurement errors inside a bone, and the possible presence of preferential directions. To address these issues, five augmented and five natural porcine vertebrae were subjected to repeated zero-strain micro-CT scan (39 Όm voxel size). The acquired images were processed with two independent DVC approaches (a local and a global one), considering different computation sub-volume sizes, in order to assess the strain measurement uncertainties. The systematic errors generally ranged within ±100 microstrain and did not depend on the computational sub-volume. The random error was higher than 1000 microstrain for the smallest sub-volume and rapidly decreased: with a sub-volume of 48 voxels the random errors were typically within 200 microstrain for both DVC approaches. While these trends were rather consistent within the sample, two individual specimens had unpredictably larger errors. For this reason, a zero-strain check on each specimen should always be performed before any in-situ micro-CT testing campaign. This study clearly shows that, when sufficient care is dedicated to preliminary methodological work, different DVC computation approaches allow measuring the strain with a reduced overall error (approximately 200 microstrain). Therefore, DVC is a viable technique to investigate strain in the elastic regime in natural and augmented bones

    The Solar Twin Planet Search. V. Close-in, low-mass planet candidates and evidence of planet accretion in the solar twin HIP 68468

    Get PDF
    [Methods]. We obtained high-precision radial velocities with HARPS on the ESO 3.6 m telescope and determined precise stellar elemental abundances (~0.01 dex) using MIKE spectra on the Magellan 6.5m telescope. [Results]. Our data indicate the presence of a planet with a minimum mass of 26 Earth masses around the solar twin HIP 68468. The planet is a super-Neptune, but unlike the distant Neptune in our solar system (30 AU), HIP 68468c is close-in, with a semi-major axis of 0.66 AU, similar to that of Venus. The data also suggest the presence of a super-Earth with a minimum mass of 2.9 Earth masses at 0.03 AU; if the planet is confirmed, it will be the fifth least massive radial velocity planet discovery to date and the first super-Earth around a solar twin. Both isochrones (5.9 Gyr) and the abundance ratio [Y/Mg] (6.4 Gyr) indicate an age of about 6 billion years. The star is enhanced in refractory elements when compared to the Sun, and the refractory enrichment is even stronger after corrections for Galactic chemical evolution. We determined a NLTE Li abundance of 1.52 dex, which is four times higher than what would be expected for the age of HIP 68468. The older age is also supported by the low log(R'HK) (-5.05) and low jitter. Engulfment of a rocky planet of 6 Earth masses can explain the enhancement in both lithium and the refractory elements. [Conclusions]. The super-Neptune planet candidate is too massive for in situ formation, and therefore its current location is most likely the result of planet migration that could also have driven other planets towards its host star, enhancing thus the abundance of lithium and refractory elements in HIP 68468. The intriguing evidence of planet accretion warrants further observations to verify the existence of the planets that are indicated by our data and to better constrain the nature of the planetary system around this unique star.Comment: A&A, in pres
    • 

    corecore