Investigation of tectonically affected groundwater systems through a multidisciplinary approach

This study uses a multidisciplinary approach to obtain a complete picture of the groundwater system of complex mountain aquifers. An Alpine region (the north-western area of Lake Como, Italy), characterized by two regional fault systems (The Breglia and Grona fault systems) containing different lithologies, was investigated using the multidisciplinary approach described here. The use of Principal Components Analysis (PCA), classical geochemical bivariate and trivariate diagrams of major and trace elements, and geostructural data, including remote sensing, permitted the identification of three principal groups of water. The first group, characterized by an enrichment of Ca2+ and HCO3-, flow in limestone. The second group is enriched in HCO3-, Ca2+ and Mg2+ and circulates through dolomite rocks. The third group, characterized by a decrease of Ca2+ and Mg2+, an increase of Na++K+ and a high Si/electrical conductivity (EC) ratio, flow in the basement rocks. Nevertheless, some peculiarities were evident. The matching of PCA, hydrochemical and geostructural information explains the role played by faults in water circulation. In particular, the Breglia fault permits the rise of deep water from crystalline basement and dolomite. Similarly, the Grona fault plays a role on drainage in proximity to the contact between the crystalline basement and the sedimentary cover. The springs located near the Grona fault rise into the crystalline basement but reflect a dolomite water chemistry. The multidisciplinary approach allowed understanding of the groundwater system and identification of fault systems not detectable with a geostructural survey

Nanocrystalline diamond-glass platform for the development of three-dimensional micro- and nanodevices

Low-cost and robust platforms are key for the development of next-generation 3D micro- and nanodevices. To fabricate such platforms, nanocrystalline diamond (NCD) is a highly appealing material due to its biocompatibility, robustness, and mechanical, electrical, electrochemical, and optical properties, while glass substrates with through vias are ideal interposers for 3D integration due to the excellent properties of glass. However, developing devices that comprise NCD films and through glass vias (TGVs) has rarely been attempted due to a lack of effective process strategies. In this work, a low-cost process - free of photolithography and transfer-printing - for fabricating arrays of TGVs that are sealed with suspended portions of an ultra-thin NCD film on one side is presented. These highly transparent structures may serve as a platform for the development of microwells for single-cell culture and analysis, 3D integrated devices such as microelectrodes, and quantum technologies. The process is demonstrated by fabricating TGVs that are sealed with an NCD film of thickness 175 nm and diameter 60 mu m. The technology described can be extended by replacing NCD with silicon nitride or silicon carbide, allowing for the development of complex heterogeneous structures on the small scale

Spatially Offset Raman Spectroscopic (SORS) Analysis of Wine Alcoholic Fermentation: A Preliminary Study

Spatially offset Raman spectroscopy (SORS) is a non-invasive analytical technique that allows the analysis of samples through a container. This makes it an effective tool for studying food and beverage products, as it can measure the sample without being affected by the packaging or the container. In this study, a portable SORS equipment was used for the first time to analyse the alcoholic fermentation process of white wine. Different sample measurement arrangements were tested in order to determine the most effective method for monitoring the fermentation process and predicting key oenological parameters. The best results were obtained when the sample was directly measured through the glass container in which the fermentation was occurring. This allowed for the accurate monitoring of the process and the prediction of density and pH with a root mean square error of cross-validation (RMSECV) of 0.0029 g·L−1 and 0.04, respectively, and R2 values of 0.993 and 0.961 for density and pH, respectively. Additionally, the sources of variability depending on the measurement arrangements were studied using ANOVA-Simultaneous Component Analysis (ASCA)

Boundary curvature effect on the wrinkling of thin suspended films

A relation between the boundary curvature κ and the wrinkle wavelength λ of a thin suspended film under boundary confinement is demonstrated. Experiments were performed with nanocrystalline diamond films of approximate thickness 184nm grown on glass substrates. By removing portions of the substrates after growth, suspended films with circular boundaries of radius 30–811 μm were fabricated. Due to residual stresses, the portions of the film bonded to the substrate are of approximate compressive prestrain 11×10⁻⁴ and the suspended portions of the film are azimuthally wrinkled at their boundary. Measurements show that λ decreases monotonically with κ, and a simple model that is in line with this trend is proposed. The model can be applied to design devices with functional wrinkles and can be adapted to gain insight into other systems such as plant leaves. A method for measuring residual compressive strain in thin films, which complements standard strain characterization methods, is also described

Improvement in the sustainability and stability of acrylic protective coatings for outdoor bronze artworks

Outdoor bronze artworks are an entrenched part of our urban landscape. They are usually covered by a patina resulting from their exposition to the environment. This patina plays an important aesthetic role and may provide some passivation on the surface, nonetheless it does not prevent the degradation processes promoted by external factors such as pollution, light and humidity. One of the strategies to slow down these unwanted processes is the application of protective coatings. The products currently available have some limitations due to the loss of effectiveness over time and poor environmental sustainability. With the aim of proposing more performing alternatives, coatings based on Paraloid (R) B44 modified with corrosion inhibitors and light stabilizers were prepared and characterized. Two non-toxic corrosion inhibitors were studied, 5-mercapto-1-pheniltetrazole (MPT) and 5-ethyl-1,3,4-thiadiazol-2-amine (AEDTA), comparing them with the traditional benzotriazole (BTA). The approach used aimed to identify the blend providing the most stable coatings. The chemical and physical properties of the coatings, such as colour, solubility, glass transition and composition, were studied and monitored over time. All coatings have shown adequate visual properties; however, corrosion inhibitors degrade some other properties of the coatings and need to be used in conjunction with light stabilizers. The permanence of corrosion inhibitors in the coatings over time was also studied by investigating the role of the support. The establishment of specific interactions between inhibitors and the bronze surface lengthens their permanence in the coatings compared to what happens with inert supports. Especially for AEDTA, the inhibitor retention within the coating and at the coating-bronze interface is better than for BTA and MPT. The effect of each of the additives on the photooxidation stability of the coating was evaluated and the most promising inhibitor and stabilizer combination was identified

Ferroelectric switching in epitaxial GeTe films

In this paper, using a resonance-enhanced piezoresponse force microscopy approach supported by density functional theory computer simulations, we have demonstrated the ferroelectric switching in epitaxial GeTe films. It has been shown that in films with thickness on the order of several nanometers reversible reorientation of polarization occurs due to swapping of the shorter and longer Ge-Te bonds in the interior of the material. It is also hinted that for ultra thin films consisting of just several atomic layers weakly bonded to the substrate, ferroelectric switching may proceed through exchange of Ge and Te planes within individual GeTe layers

Assessment of variability sources in grape ripening parameters by using FTIR and multivariate modelling

The variability in grape ripening is associated with the fact that each grape berry undergoes its own biochemical processes. Traditional viticulture manages this by averaging the physicochemical values of hundreds of grapes to make decisions. However, to obtain accurate results it is necessary to evaluate the different sources of variability, so exhaustive sampling is essential. In this article, the factors “grape maturity over time” and “position of the grape” (both in the grapevine and in the bunch/cluster) were considered and studied by analyzing the grapes with a portable ATR-FTIR instrument and evaluating the spectra obtained with ANOVA–simultaneous component analysis (ASCA). Ripeness over time was the main factor affecting the characteristics of the grapes. Position in the vine and in the bunch (in that order) were also significantly important, and their effect on the grapes evolves over time. In addition, it was also possible to predict basic oenological parameters (TSS and pH with errors of 0.3 °Brix and 0.7, respectively). Finally, a quality control chart was built based on the spectra obtained in the optimal state of ripening, which could be used to decide which grapes are suitable for harvest

Fetal growth and spontaneous preterm birth in high‐altitude pregnancy: A systematic review, meta‐analysis, and meta‐regression

Abstract: Objective: To understand the relationship between birth weight and altitude to improve health outcomes in high‐altitude populations, to systematically assess the impact of altitude on the likelihood of low birth weight (LBW), small for gestational age (SGA), and spontaneous preterm birth (sPTB), and to estimate the magnitude of reduced birth weight associated with altitude. Methods: PubMed, OvidEMBASE, Cochrane Library, Medline, Web of Science, and clinicaltrials.gov were searched (from inception to November 11, 2020). Observational, cohort, or case‐control studies were included if they reported a high altitude (>2500 m) and appropriate control population. Results: Of 2524 studies identified, 59 were included (n = 1 604 770 pregnancies). Data were abstracted according to PRISMA guidelines, and were pooled using random‐effects models. There are greater odds of LBW (odds ratio [OR] 1.47, 95% confidence interval [CI] 1.33–1.62, P < 0.001), SGA (OR 1.88, 95% CI 1.08–3.28, P = 0.026), and sPTB (OR 1.23, 95% CI 1.04–1.47, P = 0.016) in high‐ versus low‐altitude pregnancies. Birth weight decreases by 54.7 g (±13.0 g, P < 0.0001) per 1000 m increase in altitude. Average gestational age at delivery was not significantly different. Conclusion: Globally, the likelihood of adverse perinatal outcomes, including LBW, SGA, and sPTB, increases in high‐altitude pregnancies. There is an inverse relationship between birth weight and altitude. These findings have important implications for the increasing global population living at altitudes above 2500 m

Engineering the semiconductor/oxide interaction for stacking twin suppression in single crystalline epitaxial silicon(111)/insulator/Si(111) heterostructures

The integration of alternative semiconductor layers on the Si material platform via oxide heterostructures is of interest to increase the performance and/or functionality of future Si-based integrated circuits. The single crystalline quality of epitaxial (epi) semiconductor-insulator-Si heterostructures is however limited by too high defect densities, mainly due to a lack of knowledge about the fundamental physics of the heteroepitaxy mechanisms at work. To shed light on the physics of stacking twin formation as one of the major defect mechanisms in (111)-oriented fcc-related heterostructures on Si(111), we report a detailed experimental and theoretical study on the structure and defect properties of epi-Si(111)/Y2O 3/Pr2O3/Si(111) heterostructures. Synchrotron radiation-grazing incidence x-ray diffraction (SR-GIXRD) proves that the engineered Y2O3/Pr2O3 buffer dielectric heterostructure on Si(111) allows control of the stacking sequence of the overgrowing single crystalline epi-Si(111) layers. The epitaxy relationship of the epi-Si(111)/insulator/Si(111) heterostructure is characterized by a type A/B/A stacking configuration. Theoretical ab initio calculations show that this stacking sequence control of the heterostructure is mainly achieved by electrostatic interaction effects across the ionic oxide/covalent Si interface (IF). Transmission electron microscopy (TEM) studies detect only a small population of misaligned type B epi-Si(111) stacking twins whose location is limited to the oxide/epiSi IF region. Engineering the oxide/semiconductor IF physics by using tailored oxide systems opens thus a promising approach to grow heterostructures with well-controlled properties. © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft

Induction of controlled hypoxic pregnancy in large mammalian species.

Progress in the study of pregnancy complicated by chronic hypoxia in large mammals has been held back by the inability to measure long-term significant reductions in fetal oxygenation at values similar to those measured in human pregnancy complicated by fetal growth restriction. Here, we introduce a technique for physiological research able to maintain chronically instrumented maternal and fetal sheep for prolonged periods of gestation under significant and controlled isolated chronic hypoxia beyond levels that can be achieved by habitable high altitude. This model of chronic hypoxia permits measurement of materno-fetal blood gases as the challenge is actually occurring. Chronic hypoxia of this magnitude and duration using this model recapitulates the significant asymmetric growth restriction, the pronounced cardiomyopathy, and the loss of endothelial function measured in offspring of high-risk pregnancy in humans, opening a new window of therapeutic research.This work was supported by The British Heart Foundation and The Royal Society. DG is Professor of Cardiovascular Physiology & Medicine at the Department of Physiology Development & Neuroscience at the University of Cambridge, Professorial Fellow and Director of Studies in Medicine at Gonville & Caius College, a Lister Institute Fellow and a Royal Society Wolfson Research Merit Award Holder.This is the final version of the article. It was first available from the American Physiological Society via http://dx.doi.org/10.14814/phy2.1261