SH-TM mathematical analogy for the two-layer case. A magnetotellurics application

The same mathematical formalism of the wave equation can be used to describe anelastic and electromagnetic wave propagation. In this work, we obtain the mathematical analogy for the reflection/refraction (transmission) problem of two layers, considering the presence of anisotropy and attenuation -- viscosity in the viscoelastic case and resistivity in the electromagnetic case. The analogy is illustrated for SH (shear-horizontally polarised) and TM (transverse-magnetic) waves. In particular, we illustrate examples related to the magnetotelluric method applied to geothermal systems and consider the effects of anisotropy. The solution is tested with the classical solution for stratified isotropic media

WASTE PLASTICS MANAGEMENT IN MUNICIPALITIES: LOGISTICS AND PROCESSES IN LOMBARDIA (NORTHERN ITALY)

A partnership of 49 Municipalities lying in Lombardia (Northern Italy) and belonging to the District \u201cMonza and Brianza\u201d has entrusted the management of the Municipal Solid Waste (MSW) to two Public Companies: \u201cC.E.M. Ambiente S.p.A.\u201d - which owns and operates a transfer station and a multi-material centre - and \u201cSERUSO S.p.A.\u201d, whose single facility is set up and equipped for a high performance factory sorting of the dry fraction of the urban waste. The catchment area is populated by 448 000, living in an area of 366 km2. The management system starts with household sorting for multi-bin curbside collection; followed by hauling to selection and physical treatment facilities; and last, transport of the selected fractions to final destinations. The yearly throughput of \u201cC.E.M. Ambiente\u201d is about 296 000 t, of which over 70% home-sorted. Extra-CEM customers add to this amount about 40 000 t/yr. When calculated on the partner municipalities, the waste generation rate is almost 1.8 kg/capita per day including waste from craftsmen and workshops. Less than 1% of the collected waste goes to landfill and about 8% to incineration with energy recovery (WTE). Since \u201cC.E.M. Ambiente\u201d operates mainly the logistics, however; and part of the materials recovery is actually made downstream its gate at \u201cSERUSO\u201d facility, where some by-products are unavoidably generated; the overall share of WTE will be slightly higher. Electric energy produced from the combustible by-products of \u201cC.E.M. Ambiente\u201d and \u201cSERUSO\u201d covers largely the energy needs of the recovery and cleaning processes. It is worthwhile stressing that in this district also waste from street sweeping \u2013 as much as 8 200 t/yr \u2013 is turned into sand, gravel and like for civil works. \u201cC.E.M. Ambiente\u201d uses also fuel energy, to operate collection and hauling vehicles and factory handling machines, all of them powered by Diesel engines. Fuel requirements for TS and MMC in 2011 were 78 405 and 14 605 litres, respectively. Regrettably, these needs cannot be satisfied in any way with recovered energy

SH-TM mathematical analogy for the two-layer case. A magnetotellurics application

The same mathematical formalism of the wave equation can be used to describe anelastic and electromagnetic wave propagation. In this work, we obtain the mathematical analogy for the reflection/refraction (transmission) problem of two layers, considering the presence of anisotropy and attenuation -- viscosity in the viscoelastic case and resistivity in the electromagnetic case. The analogy is illustrated for SH (shear-horizontally polarised) and TM (transverse-magnetic) waves. In particular, we illustrate examples related to the magnetotelluric method applied to geothermal systems and consider the effects of anisotropy. The solution is tested with the classical solution for stratified isotropic media

Estimating pore-space gas hydrate saturations from well log acoustic data

This paper is not subject to U.S. copyright. The definitive version was published in Geochemistry Geophysics Geosystems 9 (2008): Q07008, doi:10.1029/2008GC002081.Relating pore-space gas hydrate saturation to sonic velocity data is important for remotely estimating gas hydrate concentration in sediment. In the present study, sonic velocities of gas hydrate–bearing sands are modeled using a three-phase Biot-type theory in which sand, gas hydrate, and pore fluid form three homogeneous, interwoven frameworks. This theory is developed using well log compressional and shear wave velocity data from the Mallik 5L-38 permafrost gas hydrate research well in Canada and applied to well log data from hydrate-bearing sands in the Alaskan permafrost, Gulf of Mexico, and northern Cascadia margin. Velocity-based gas hydrate saturation estimates are in good agreement with Nuclear Magneto Resonance and resistivity log estimates over the complete range of observed gas hydrate saturations

Geophysical signature of a World War i tunnel-like anomaly in the Forni Glacier (Punta Linke, Italian Alps)

Global warming and the associated glacier retreat recently revealed the entrance to an ice\u2013rock tunnel, at an altitude of 3c3600 m a.s.l., in the uppermost portion of the Forni Glacier in the Central Italian Alps. The tunnel served as an entrance to an Austro-Hungarian cableway station excavated in the rocks during the Great War just behind the frontline. A comprehensive geophysical survey, based on seismic and ground-penetrating radar profiling, was then undertaken to map other possibleWorldWar I (WWI) remains still embedded in the ice. The ice\u2013rock interface was reconstructed over the entire saddle and in the uppermost portion of the glacier. A prominent linear reflector was surprisingly similar to the common response of buried pipes. The reflector orientation, almost longitudinal to the slope, does not seem to be compatible with a glacial conduit or with other natural features. Numerical simulations of a series of possible targets constrained interpretation to a partly water-filled rounded shape cavity. The presence of a preserved WWI tunnel connecting Mount Vioz and Punta Linke could be considered a realistic hypothesis. The Forni glacier could be still considered polythermal and comprised of cold ice without basal sliding in its top portion

A Sustainable Hydroxypropyl Cellulose-Nanodiamond Composite for Flexible Electronic Applications

Designing fully green materials for flexible electronics is an urgent need due to the growing awareness of an environmental crisis. With the aim of developing a sustainable, printable, and biocompatible material to be exploited in flexible electronics, the rheological, structural and charge transport properties of water-based hydroxypropyl cellulose (HPC)-detonation nanodiamond (DND) viscous dispersions are investigated. A rheological investigation disclosed that the presence of the DND affects the orientation and entanglement of cellulose chains in the aqueous medium. In line with rheological analyses, the NMR diffusion experiments pointed out that the presence of DND modifies the hydrodynamic behavior of the cellulose molecules. Despite the increased rigidity of the system, the presence of DND slightly enhances the ionic conductivity of the dispersion, suggesting a modification in the charge transport properties of the material. The electrochemical analyses, performed through Cyclic Voltammetry (CV) and Electrochemical Impedance Spectroscopy (EIS), revealed that the HPC-DND system is remarkably stable in the explored voltage range (−0.1 to +0.4 V) and characterized by a lowered bulk resistance with respect to HPC. Such features, coupled with the printability and filmability of the material, represent good requirements for the exploitation of such systems in flexible electronic applications

Combined Use of Phenotypic Screening and of a Novel Commercial Assay (REALQUALITY Carba-Screen) for the Rapid Molecular Detection of Carbapenemases: A Single-Center Experience

Carbapenem resistance is a serious public health threat, causing numerous deaths annually primarily due to healthcare-associated infections. To face this menace, surveillance programs in high-risk patients are becoming a widespread practice. Here we report the performance of the combined use of a recently approved commercial multiplex real-time PCR assay (REALQUALITY Carba-Screen kit) with conventional phenotypic screening. In this three-month study, 479 rectal swabs from 309 patients across high-risk units were evaluated by combining the two approaches. Although the molecular assay showed a higher positivity rate than phenotypic screening (7.1% vs. 5%), it should be noted that the molecular method alone would have missed eight carbapenem-resistant isolates, while using only phenotypic screening would not have detected sixteen isolates. This demonstrates the complementary strengths of each method. Our study confirms the need for a combined approach to maximize the possible clinical impact of this kind of screening, ensuring a more comprehensive detection of resistant strains

Organic Bioelectronics Development in Italy: A Review

In recent years, studies concerning Organic Bioelectronics have had a constant growth due to the interest in disciplines such as medicine, biology and food safety in connecting the digital world with the biological one. Specific interests can be found in organic neuromorphic devices and organic transistor sensors, which are rapidly growing due to their low cost, high sensitivity and biocompatibility. This trend is evident in the literature produced in Italy, which is full of breakthrough papers concerning organic transistors-based sensors and organic neuromorphic devices. Therefore, this review focuses on analyzing the Italian production in this field, its trend and possible future evolutions