Domestic well vulnerability to drought duration and unsustainable groundwater management in California's Central Valley

Millions of Californians access drinking water via domestic wells, which are vulnerable to drought and unsustainable groundwater management. Groundwater overdraft and the possibility of longer drought duration under climate change threatens domestic well reliability, yet we lack tools to assess the impact of such events. Here, we leverage 943 469 well completion reports and 20 years of groundwater elevation data to develop a spatially-explicit domestic well failure model covering California's Central Valley. Our model successfully reproduces the spatial distribution of observed domestic well failures during the severe 2012-2016 drought (n = 2027). Next, the impact of longer drought duration (5-8 years) on domestic well failure is evaluated, indicating that if the 2012-2016 drought would have continued into a 6 to 8 year long drought, a total of 4037-5460 to 6538-8056 wells would fail. The same drought duration scenarios with an intervening wet winter in 2017 lead to an average of 498 and 738 fewer well failures. Additionally, we map vulnerable wells at high failure risk and find that they align with clusters of predicted well failures. Lastly, we evaluate how the timing and implementation of different projected groundwater management regimes impact groundwater levels and thus domestic well failure. When historic overdraft persists until 2040, domestic well failures range from 5966 to 10 466 (depending on the historic period considered). When sustainability is achieved progressively between 2020 and 2040, well failures range from 3677 to 6943, and from 1516 to 2513 when groundwater is not allowed to decline after 2020

THE TRUNK ORIENTATION DURING SPRINT START ESTIMATED USING A SINGLE INERTIAL SENSOR

Sprint start and block acceleration are two very important phases which could determine the result of a sprint. Tellez & Doolittle (1984) showed that these two phases account for 64% of the total result for a 100m sprint. Sprinters have to move from a crouch to a standing position, trying to reach their maximal velocity as fast as possible. Many authors have delved into the biomechanical factors concerning both phases (Fortier et al., 2005; Harland & Steele, 1997; Schot & Knutzen, 1992). Trunk orientation is considered by coaches one of the key elements in moving from the crouch to the upright position, however only a few studies focused specifically on this parameter (Čoh et al., 1998; Čoh et al., 2006; Natta et al., 2006). Moreover, the experimental setups used in the latter studies are quite cumbersome and limited in terms of acquisition volume (motion capture systems, high-speed cameras or optical contact time meters), therefore, they are hardly usable during everyday training sessions. Wearable inertial measurement units (IMU), that embed 3D linear acceleration and angular rate sensors (accelerometers and gyroscopes), can be effectively used to perform in-field biomechanical analysis of sprint running, providing information useful for performance optimisation and injury prevention. In particular, IMUs provide an estimate of body segment rotations relative to an inertia system of reference with one axis oriented as the gravitational field. The aim of this pilot study is to validate the use of a single IMU to estimate the trunk orientation angle in the progression plane during a sprint start from the blocks

Boosting intermediate temperature performance of solid oxide fuel cells via a tri‐layer ceria–zirconia–ceria electrolyte

Using cost-effective fabrication methods to manufacture a high-performance solid oxide fuel cell (SOFC) is helpful to enhance the commercial viability. Here, we report an anode-supported SOFC with a three-layer Gd$_{0.1}$Ce$_{0.9}$O$_{1.95}$ (gadolinia-doped-ceria [GDC])/Y$_{0.148}$Zr$_{0.852}$O$_{1.926}$ (8YSZ)/GDC electrolyte system. The first dense GDC electrolyte is fabricated by co-sintering a thin, screen-printed GDC layer with the anode support (NiO–8YSZ substrate and NiO–GDC anode) at 1400°C for 5 h. Subsequently, two electrolyte layers are deposited via physical vapor deposition. The total electrolyte thickness is less than 5 μm in an area of 5 × 5 cm$^2$, enabling an area-specific ohmic resistance as low as 0.125 Ω cm$^{−2}$ at 500°C (under open circuit voltage), and contributing to a power density as high as 1.2 W cm$^{−2}$ at 650°C (at an operating cell voltage of 0.7 V, using humidified [10 vol.% H$_2$O] H$_2$ as fuel and air as oxidant). This work provides an effective strategy and shows the great potential of using GDC as an electrolyte for high-performance SOFC at intermediate temperature

Post cardiac surgery vasoplegia is associated with high preoperative copeptin plasma concentration

International audienceABSTRACT: INTRODUCTION: Post cardiac surgery vasodilatation is possibly related to a vasopressin deficiency that could be related to a chronic stimulation of the adeno-hypophysis. To assess vasopressin system activation, perioperative course of copeptin and vasopressin plasma concentrations have been studied in consecutive patients operated on cardiac surgery. METHODS: 64 consecutive patients scheduled for elective cardiac surgery with cardiopulmonary bypass were studied. Haemodynamic, laboratory and clinical data were recorded before and during cardiopulmonary bypass, and at the 8th post-operative hour (H8). At the same time, point's blood was withdrawn to determine plasma concentrations of arginine-vasopressin (AVP, radioimmunoassay) and copeptin (immunoluminometric assay). Post cardiac surgery vasodilation (PCSV) was defined as a mean arterial blood pressure less than 60 mmHg with a cardiac index [equal to or greater than] 2.2 L * min^-1 * m^-2, and was treated with norepinephrine (NE) in order to restore a mean blood pressure > 60 mmHg. Patients with PCSV were compared to the other patients (controls). Student's t, Fisher's exact test, or non parametric tests (Mann Whitney, Wilkoxon) were used when appropriate. A correlation between AVP and copeptin has been evaluated and a receiver-operator characteristic (ROC) analysis was calculated to assess the utility of preoperative copeptin to distinguish between controls and PCSV patients. RESULTS: Patients who experienced a PCSV have significantly higher copeptin plasma concentration before cardiopulmonary bypass (P <0.001) but lower AVP concentrations at H8 (P <0.01) than controls. PCSV patients had preoperative hyponatremia and decreased left ventricle ejection fraction, and experienced more complex surgery (redo). The area under the ROC curve of preoperative copeptin concentration was 0.86[plus/minus]0.04 [95%CI: 0.78-0.94] (P <0.001). The best predictive value for preoperative copeptin plasma concentration was 9.43 pmol/L with a sensitivity of 90% and a specificity of 77%. CONCLUSIONS: High preoperative copeptin plasma concentration is predictive of PSCV and suggests an activation of the AVP system before surgery that may facilitate depletion of endogenous AVP stores and a relative AVP deficit after surgery

Tectonic Regime as a Control Factor for Crustal Fault Zone (CFZ) Geothermal Reservoir in an Amagmatic System: A 3D Dynamic Numerical Modeling Approach

Crustal fault zones provide interesting geological targets for high-temperature geothermal energy source in naturally deep-fractured basement areas. Field and laboratory studies have shown the ability of these systems to let fluid flow down to the brittle–ductile transition. However, several key questions about exploration still exist, in particular the fundamental effect of tectonic regimes on fluid flow in fractured basement domains. Based on poro-elasticity assumption, we considered an idealized 3D geometry and realistic physical properties. We examined a model with no tectonic regime (benchmark experiment) and a model with different tectonic regimes, namely a compressional, an extensional and a strike-slip tectonic regime. Compared to the benchmark experiment, the results demonstrate that different tectonic regimes cause pressure changes in the fault/basement system. The tectonic-induced pressure changes affect convective patterns, onset of convection as well as the spatial extent of thermal plumes and the intensity of temperature anomalies. Driven by poro-elastic forces, temperature anomalies around vertical faults in a strike-slip tectonic regime have a spatial extent that should be considered in preliminary exploratory phases

G0^0 Electronics and Data Acquisition (Forward-Angle Measurements)

The G$^0$ parity-violation experiment at Jefferson Lab (Newport News, VA) is designed to determine the contribution of strange/anti-strange quark pairs to the intrinsic properties of the proton. In the forward-angle part of the experiment, the asymmetry in the cross section was measured for $\vec{e}p$ elastic scattering by counting the recoil protons corresponding to the two beam-helicity states. Due to the high accuracy required on the asymmetry, the G$^0$ experiment was based on a custom experimental setup with its own associated electronics and data acquisition (DAQ) system. Highly specialized time-encoding electronics provided time-of-flight spectra for each detector for each helicity state. More conventional electronics was used for monitoring (mainly FastBus). The time-encoding electronics and the DAQ system have been designed to handle events at a mean rate of 2 MHz per detector with low deadtime and to minimize helicity-correlated systematic errors. In this paper, we outline the general architecture and the main features of the electronics and the DAQ system dedicated to G$^0$ forward-angle measurements.Comment: 35 pages. 17 figures. This article is to be submitted to NIM section A. It has been written with Latex using \documentclass{elsart}. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment In Press (2007

Performances of Solid Oxide Cells with La0.97_{0.97}Ni0.5_{0.5}Co0.5_{0.5}O3−δ_{3-\delta} as Air-Electrodes

Based on previous studies of perovskites in the quasi-ternary system LaFeO$_{3}$–LaCoO$_{3}$–LaNiO$_{3}$, La$_{0.97}$Ni$_{0.5}$Co$_{0.5}$O$_{3}$ (LNC) is chosen as the most promising air-electrode material in the series for solid oxide cells (SOCs). The properties of the material itself have been investigated in detail. However, the evaluation of LNC97 air electrodes in practical SOCs is still at a very early stage. In the present study, SOCs were prepared based on LNC97 air electrodes. The I-U performance of the SOCs in both solid oxide fuel cell (SOFC) and solid oxide electrolysis cell (SOEC) modes, i.e. reversible SOCs (r-SOCs), was investigated systematically for different air-electrode designs, temperatures and fuel gases. In general, the performance of the r-SOCs tested in the present study is higher than the published results of other LaFeO$_{3}$–LaCoO$_{3}$–LaNiO$_{3}$-based SOCs and is comparable to or even better than state-of-the-art La$_{1-x}$Sr$_{x}$Fe$_{1-y}$Co$_{y}$O$_{3}$ (LSCF)-based SOCs. Mid-term operation of about 1000 h for SOCs in both SOFC and SOEC modes primarily proved the stability of LNC97-based air electrodes. Impedance spectra were systematically applied to understand the polarization processes of the SOCs