The CLT Panels in Structural Restoration: Characteristics and Technical Regulations

Wood can represent a valid and important alternative to the most commonly used structural materials for the restoration of masonry buildings, with a view to efficient, effective and "conscious" renovation. Today, the modern technologies allows to overcome the structural limits of solid wood due to its own anisotropy. The use of composite wood elements makes possible to obtain excellent mechanical performances that consent to evaluate aspects such as the use of low environmental impact retrofit strategies. The aim of this work is the analysis of mechanical parameters related to CLT (cross laminated timber) panels in order to determine their possible use in the structural restoration of masonry buildings. The CLT panels consist of solid wood planks superimposed so that each layer has the fibres rotated ninety degrees with respect to the adjacent layer. The layers (always in odd number and at least three) can be connected by discrete joints, pins and nails, or glued together. This onfiguration enables to product large structural elements with considerable thickness. Two different experimental test campaigns were carried out on samples of panels with three and five glued layers. The purpose of experimentation activities was to evaluate the bending deformation of the wooden elements and shear strength of the bonding sections. All the tests were processed according to the provisions contained in the UNI standards. The test results were then compared with different theoretical calculation models to determine the one that best represents the tested material. The tests outcomes have shown that some characteristics of the material, such as the remarkable ductility, open different scenarios of use for the CLT panels in the field of structural restoration of masonry buildings

Microwave intermodulation distortion of MgB2 thin films

The two tone intermodulation arising in MgB2 thin films deposited in-situ by planar magnetron sputtering on sapphire substrates is studied. Samples are characterised using an open-ended dielectric puck resonator operating at 8.8 GHz. The experimental results show that the third order products increase with the two-tone input power with a slope ranging between 1.5 and 2.3. The behaviour can be understood introducing a mechanism of vortex penetration in grain boundaries as the most plausible source of non linearities in these films. This assumption is confirmed by the analysis of the field dependence of the surface resistance, that show a linear behaviour at all temperatures under test.Comment: 13 pages, 3 figures; to be published in Appl. Phys. Let

Transport in strongly-coupled graphene-LaAlO3/SrTiO3 hybrid systems

We report on the transport properties of hybrid devices obtained by depositing graphene on a LaAlO3/SrTiO3 oxide junction hosting a 4 nm-deep two-dimensional electron system. At low graphene-oxide inter-layer bias the two electron systems are electrically isolated, despite their small spatial separation, and very efficient reciprocal gating is shown. A pronounced rectifying behavior is observed for larger bias values and ascribed to the interplay between electrostatic depletion and tunneling across the LaAlO3 barrier. The relevance of these results in the context of strongly-coupled bilayer systems is discussed.Comment: 10 pages, 3 figure

Experimental evidence of s-wave superconductivity in bulk CaC6_{6}

The temperature dependence of the in-plane magnetic penetration depth, $\lambda_{ab}(T)$, has been measured in a c-axis oriented polycrystalline CaC$_{6}$ bulk sample using a high-resolution mutual inductance technique. A clear exponential behavior of $\lambda_{ab}(T)$ has been observed at low temperatures, strongly suggesting isotropic s-wave pairing. Data fit using the standard BCS theory yields $\lambda_{ab}(0)=(720\pm 80)$ Angstroem and $\Delta(0)=(1.79\pm 0.08)$ meV. The ratio $2\Delta(0)/k_{_B}T_{c}=(3.6\pm 0.2)$ gives indication for a conventional weakly coupled superconductor.Comment: To appear in Phys. Rev. Let

Infodemiological patterns in searching medication errors: Relationship with risk management and shift work

INTRODUCTION: Western world health care systems have been trying to improve their efficiency and effectiveness in order to respond properly to population aging and non-communicable diseases epidemic. Treatment of the elderly population is becoming complex due to the high number of prescribed drugs because of multimorbidity. Errors in drugs administration in different health care related settings are an actual important issue due to different causes. Aim of this observational study is to measure the online interest in seeking medication errors information related to risk management and shift work. MATERIALS AND METHODS: We investigated Google Trends® for popular search relating to medication errors, risk management and shift work. Relative search volumes (RSVs) were evaluated from 2008 to 2018. A comparison between RSV curves related to medication errors, risk management and shift work was carried out. Then, we compared the world to Italian search. RESULTS: RSVs were persistently higher for risk management than for medication errors (mean RSVs 069 vs. 48%) and RSVs were stably higher for medication errors than shift work (mean RSVs 48 vs. 22%). In Italy, RSVs were much lower compared to the rest of the world, and RSVs for medication errors during the study period were negligible. Mean RSVs for risk management and shift work were 3 and 25%, respectively. RSVs related to medication errors and clinical risk management were correlated (r=0.520, p<0.0001). CONCLUSIONS: Google Trends® search query volumes related to medication errors, risk management and shift work are different. RSVs for risk management are higher, and they are correlated with medication errors. Also, shift work search appears to be lower. These results should be interpreted in order to correctly evaluate how to decrease the number of medication errors in different health care related setting

Clearance Operation of Teulada Site (Italy): A Novel Approach for Short Term MCM Missions in Seafloor Hard Conditions

In May 2007, following a request by Italian Navy (ITN), NURC agreed to provide the technology, developed during the port protection studies and 2006 MCM ops. in Baltic sea for Estonian Navy, to survey part of the Capo Teulada firing range (Sardinia Island, Italy), used by NATO Armed Forces. The goal of the service, fully funded by ITN, was to survey part of the firing range with acoustic, magnetic and optical instruments in order to detect and classify the ordnance laying on the seafloor. The team operated from CRV Leonardo to produce a detailed acoustic and magnetic map of the area. The positions of the targets of interest have been provided to Italian Navy for further identification and disposal. The activities have demonstrated that the NURC Autonomous Underwater Vehicles (AUVs) Remus type equipped with high frequency side scan sonar can detect and classify targets of the dimensions of unexploded ordnance laying proud on the sea floor. A multiple sonar images technique has also been used to improve the classification performances. However, in some areas, targets that were completely buried or concealed in Posidonia fields wouldn’t have been detectable with AUV sonar. To overcome this limitation, INGV supported the NURC team by using a new high definition magnetometer technique to detect and classify buried metal targets. A proton Overhauser sensor was towed from Leonardo vessel and a magnetometer reference station was set ashore in an appropriate site. A subset of interesting contacts (acoustic and magnetic) have been identified optically by means of the video camera installed on the ROV (Pluto Plus type by Gaymarine) operated from Leonardo. The positioning accuracy achieved was fully compatible with the reacquisition by ROV and then by divers or mine hunters for future disposal ops. The survey has also produced an accurate map of the Posidonia fields and a detailed bathymetry of the area. More than 300 contacts have been acquired and more than 200 were classified in less than 15 days. The success of Teulada operation has convinced ITN to ask NURC for a common development programme with the aim to validate at sea a fully integrated multi-sensor approach (sonar, magnetic and optical) in MCM short term ops. using USV/AUV platforms

Unmanned Aerial Vehicle (UAV)-based remote sensing to monitor grapevine leaf stripe disease within a vineyard affected by esca complex

Foliar symptoms of grapevine leaf stripe disease (GLSD, a disease within the esca complex) are linked to drastic alteration of photosynthetic function and activation of defense responses in affected grapevines several days before the appearance of the first visible symptoms on leaves. The present study suggests a methodology to investigate the relationships between high-resolution multispectral images (0.05 m/pixel) acquired using an Unmanned Aerial Vehicle (UAV), and GLSD foliar symptoms monitored by ground surveys. This approach showed high correlation between Normalized Differential Vegetation Index (NDVI) acquired by the UAV and GLSD symptoms, and discrimination between symptomatic from asymptomatic plants. High-resolution multispectral images were acquired during June and July of 2012 and 2013, in an experimental vineyard heavily affected by GLSD, located in Tuscany (Italy), where vines had been surveyed and mapped since 2003. Each vine was located with a global positioning system, and classified for appearance of foliar symptoms and disease severity at weekly intervals from the beginning of each season. Remote sensing and ground observation data were analyzed to promptly identify the early stages of disease, even before visual detection. This work suggests an innovative methodology for quantitative and qualitative analysis of spatial distribution of symptomatic plants. The system may also be used for exploring the physiological bases of GLSD, and predicting the onset of this disease.

Discrete model analysis of the critical current density measurements in superconducting thin films by a single coil inductive method

The critical current density of a superconducting film can be easily determined by an inductive and contactless method. Driving a sinusoidal current in a single coil placed in front of a superconducting sample, a non zero third harmonic voltage V_3 is induced in it when the sample goes beyond the Bean critical state. The onset of V_3 marks the value of current beyond which the sample response to the magnetic induction is no more linear. To take into account, in a realistic way, the magnetic coupling between the film and the coil we have developed a discrete model of the inducing and induced currents distribution. In the framework of this model the magnetic field profile on the sample surface and the coefficient linking the current flowing in the coil and the critical current density J_C of superconducting thin films is evaluated. The numerical results are checked measuring J_C of several thin films of YBa_2Cu_3O_(7-d) of known superconducting properties, used as a control material.Comment: to be published in Journal of Applied Physic