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Underground gas storage (UGS) in depleted hydrocarbon reservoirs is a strategic practice to cope with the growing energy demand and occurs in many places in Europe and North America. In response to summer gas injection and winter gas withdrawal the reservoir expands and contracts essentially elastically as a major consequence of the fluid (gas and water) pore pressure fluctuations. Depending on a number of factors, including the reservoir burial depth, the difference between the largest and the smallest gas pore pressure, and the geomechanical properties of the injected formation and the overburden, the porous medium overlying the reservoir is subject to three‐dimensional deformation with the related cyclic motion of the land surface being both vertical and horizontal. We present a methodology to evaluate the environmental impact of underground gas storage and sequestration from the geomechanical perspective, particularly in relation to the ground surface displacements. Long‐term records of injected and removed gas volume and fluid pore pressure in the “Lombardia” gas field, northern Italy, are available together with multiyear detection of vertical and horizontal west‐east displacement of the land surface above the reservoir by an advanced permanent scatterer interferometric synthetic aperture radar (PSInSAR) analysis. These data have been used to calibrate a 3‐D fluid‐dynamic model and develop a 3‐D transversally isotropic geomechanical model. The latter has been successfully implemented and used to reproduce the vertical and horizontal cyclic displacements, on the range of 8–10 mm and 6–8 mm, respectively, measured between 2003 and 2007 above the reservoir where a UGS program has been underway by Stogit‐Eni S.p.A. since 1986 following a 5 year field production life. Because of the great economical interest to increase the working gas volume as much as possible, the model addresses two UGS scenarios where the gas pore overpressure is pushed from the current 103%pi, where pi is the gas pore pressure prior to the field development, to 107%pi and 120%pi. Results of both scenarios show that there is a negligible impact on the ground surface, with deformation gradients that remain well below the most restrictive admissible limits for the civil structures and infrastructures. Key Points Evaluation of the environmental impact of UGS projects Set‐up and calibration of a 3‐D FE transversally isotropic geomechanical model PSInSAR analysis to measure vertical/horizontal movements of the land surface

Knowledge of ground compressibility in unloading/reloading conditions is of paramount importance in several geomechanical processes, but its estimate is often affected by large uncertainties, especially for deep rocks. Satellite measurements of the land motion can help improve this information. The present study investigates the ground response due to underground gas storage activities as revealed by satellite interferometric measurements in three gas fields of the Po river basin, Italy. The ground proves to behave elastically, moving upwards and downwards in response to gas injection and extraction, respectively. The accurate calibration of a detailed geomechanical, transversely isotropic, finite-element model allows for an indirect estimate of the vertical ground compressibility in unloading/reloading conditions, which proves consistent with the results already available from the same basin. Assuming a hypo-plastic constitutive model for the compressibility in virgin loading conditions, the ratio between I cycle and II cycle compressibility at the load inversion turns out to be between 3·5 and 4·0 in the depth range 1100–1500 m, again proving to be in good agreement with other results obtained in the same basin.

Recent numerical studies based on a simplified lithostratigraphy of the Venice subsurface suggest that the city may be raised by pumping seawater into deep aquifers through 12 wells located on a 10 km diameter circle. Using an updated 3‐D reconstruction of the Quaternary deposits, developed very recently from about 1050 km of multichannel seismic profiles and eight exploration wells, along with a more accurate representation of the injection boreholes, novel finite‐element predictions are performed. The new model simulates the lithostratigraphy of the lagoon subsurface and allows for a reliable assessment of the water volumes injected into the geologic formations based on the actual bottom hole overpressure that can vary both in space and time. Pumping occurs into two Pleistocene sequences that are originated from the Alps and Apennine sedimentation and terminate just south and north of Venice, respectively, and the shelf portion of a Pliocene sequence that is rather continuous below the central lagoon with arenite layers to depths as much as 1000 m below mean sea level. With a proper tuning of the injection pressure the new hydrogeologic model allows for a prediction of a quite uniform 25–30 cm uplift over 10 years after the inception of injection. The gradient of the vertical displacement ξz does not exceed 5 × 10−5 and 1 × 10−5 in the whole lagoon and Venice, respectively, i.e., well below the most conservative bound recommended for the safety of the structures. If ad hoc calibrated injection overpressures are implemented in each single well, ξz may be reduced to as much as 0.1 × 10−5 throughout the city. Key Points Injecting seawater significantly contributes to city protection from high water A novel 3D geologic model of the Venice subsurface based on 1050km seismic lines A proper tuning of injection pressures allows for a uniform 25 cm Venice uplift

The generation and manipulation of single photons is important for quantum information and metrology. Highly bright and stable single-photon sources are now identified in silicon carbide, a wide-bandgap semiconductor widely used for photonic and electronic devices. Over the past few years, single-photon generation has been realized in numerous systems: single molecules 1 , quantum dots 2 , 3 , 4 , diamond colour centres 5 and others 6 . The generation and detection of single photons play a central role in the experimental foundation of quantum mechanics 7 and measurement theory 8 . An efficient and high-quality single-photon source is needed to implement quantum key distribution, quantum repeaters and photonic quantum information processing 9 . Here we report the identification and formation of ultrabright, room-temperature, photostable single-photon sources in a device-friendly material, silicon carbide (SiC). The source is composed of an intrinsic defect, known as the carbon antisite–vacancy pair, created by carefully optimized electron irradiation and annealing of ultrapure SiC. An extreme brightness (2×10 6  counts s −1 ) resulting from polarization rules and a high quantum efficiency is obtained in the bulk without resorting to the use of a cavity or plasmonic structure. This may benefit future integrated quantum photonic devices 9 .

Approximately 800 million people worldwide are infected with one or more species of skin-penetrating nematodes. These parasites persist in the environment as developmentally arrested third-stage infective larvae (iL3s) that navigate toward host-emitted cues, contact host skin, and penetrate the skin. iL3s then reinitiate development inside the host in response to sensory cues, a process called activation. Here, we investigate how chemosensation drives host seeking and activation in skin-penetrating nematodes. We show that the olfactory preferences of iL3s are categorically different from those of free-living adults, which may restrict host seeking to iL3s. The human-parasitic threadworm Strongyloides stercoralis and hookworm Ancylostoma ceylanicum have highly dissimilar olfactory preferences, suggesting that these two species may use distinct strategies to target humans. CRISPR/Cas9-mediated mutagenesis of the S. stercoralis tax-4 gene abolishes iL3 attraction to a host-emitted odorant and prevents activation. Our results suggest an important role for chemosensation in iL3 host seeking and infectivity and provide insight into the molecular mechanisms that underlie these processes.

Electrically driven single-photon emitting devices have immediate applications in quantum cryptography, quantum computation and single-photon metrology. Mature device fabrication protocols and the recent observations of single defect systems with quantum functionalities make silicon carbide an ideal material to build such devices. Here, we demonstrate the fabrication of bright single-photon emitting diodes. The electrically driven emitters display fully polarized output, superior photon statistics (with a count rate of >300 kHz) and stability in both continuous and pulsed modes, all at room temperature. The atomic origin of the single-photon source is proposed. These results provide a foundation for the large scale integration of single-photon sources into a broad range of applications, such as quantum cryptography or linear optics quantum computing. Single-photon emitters are required for quantum cryptography and computation and single-photon metrology. Here, Lohrmann et al . fabricate electrically driven, single-photon emitting diodes in silicon carbide with a fully polarized output, high emission rates and stability at room temperature.

Los viajes de toda la vida de Paul Bourget a Italia parecen haber influido en su carrera literaria y en su evolución intelectual, de diletante a novelista de éxito y crítico psicológico. ¿Cómo condicionaron estas sensaciones artísticas italianas a Bourget para establecer una crítica psicológica cada vez más sistemática? ¿Cómo se refleja esta italianización en sus novelas y cuáles son las referencias artísticas que determinaron esta inclinación? Siguiendo el curso de esta peregrinación y el desarrollo de sus escritos, Italia parece un punto de inflexión en la evolución del pensamiento psicológico de Bourget. El objetivo de este artículo es precisamente arrojar luz sobre esta hipótesis y dar algunas claves de lectura para entender mejor la crítica del escritor.

Objectives: To explore the effectiveness of alcohol drinking and tobacco smoking cessation in reducing esophageal cancer risk, taking into account the key characteristics of each habit and the simultaneous exposure to both habits. Methods: Data from a series of five hospital-based case-control studies of incident squamous-cell carcinoma of the esophagus conducted by the International Agency for Research on Cancer (IARC, Lyon, France) in high-risk areas in South America were combined and analyzed by multivariate logistic regression procedures. A total of 2063 men (655 case patients and 1408 control subjects) were included in the pooled analysis. Results: For either habit, the risk of esophageal cancer decreased rapidly, strongly and significantly with longer periods of abstention. The risk reduction was statistically significant regardless of the intensity and duration of each habit and the type of tobacco or alcoholic drink consumed. For subjects exposed to both risk factors, the protective effect of quitting both habits appeared to be synergistic, reaching, after only five to nine years of simultaneous cessation of both exposures, a 70% risk reduction, a reduction that clearly overlapped with the risk intervals of both never-smokers and never-drinkers. The risk benefit of merely quitting alcohol drinking was delayed (>10 years of cessation) unless it was also accompanied by a few years of smoking cessation. Conclusions: Our findings solidly demonstrate for the first time the effectiveness of smoking and drinking cessation in reducing esophageal cancer risk. For the large proportion of subjects in the general population exposed to both risk factors, our results further emphasize the importance of smoking cessation to effectively reduce cancer risk.

We model the broadband enhancement of single-photon emission from color centres in silicon carbide nanocrystals coupled to a planar hyperbolic metamaterial, HMM resonator. The design is based on positioning the single photon emitters within the HMM resonator, made of a dielectric index-matched with silicon-carbide material. The broadband response results from the successive resonance peaks of the lossy Fabry Perot structure modes arising within the high-index HMM cavity. To capture this broadband enhancement in the single photon emitters spontaneous emission, we placed a simple gold based cylindrical antenna on top of the HMM resonator. We analyzed the performance of this HMM coupled antenna structure in terms of the Purcell enhancement, quantum efficiency, collection efficiency and overall collected photon rate. For perpendicular dipole orientation relative to the interface, the HMM coupled antenna resonator leads to a significantly large spontaneous emission enhancement with Purcell factor of the order of 250 along with a very high average total collected photon rate, CPR of about 30 over a broad emission spectrum, 700 nm to 1000 nm. The peak CPR increases to about 80 at 900 nm, corresponding to the emission of silicon-carbide quantum emitters. This is a state of the art improvement considering the previous computational designs have reported a maximum average CPR of 25 across the nitrogen-vacancy centre emission spectrum, 600 nm to 800 nm with the highest value being about 40 at 650 nm.

We investigate the microwave magnetic field confinement in several microwave 3D-cavities, using 3D finite-element analysis to determine the best design and achieve strong coupling between microwave resonant cavity photons and solid state spins. Specifically, we design cavities for achieving strong coupling of electromagnetic modes with an ensemble of nitrogen vacancy (NV) defects in diamond. We report here a novel and practical cavity design with a magnetic filling factor of up to 4 times (2 times higher collective coupling) than previously achieved using 1D superconducting cavities with small mode volume. In addition, we show that by using a double-split resonator cavity, it is possible to achieve up to 200 times better cooperative factor than the currently demonstrated with NV in diamond. These designs open up further opportunities for studying strong and ultra-strong coupling effects on spins in solids using alternative systems with a wider range of design parameters.