Grantmakers for Effective Organizations

An acoustic emission (AE) system with eight channels of recording was used to monitor failure of a sandstone in plane-strain compression. The recorded wave forms were analyzed for event location and source characterization. The complicated deconvolution process was eliminated by assuming that the first peak of the signal recorded by an AE sensor corresponds to the first peak of the normal displacement at the sensor. The seismic moment tensor of each event was evaluated, and the source mechanisms were determined. The sources of the post-peak events were characterized as being caused predominantly by shear. The slip displacement of each acoustic emission was estimated from the seismic moment tensor by assuming a constant strain drop of 10−4 over the slip area. Within a certain portion of the post-peak regime where 110 events were captured, the slip displacement was 0.0217 mm from the seismic estimate and 0.0335 mm from the global measurement. The seismic energy per unit area from acoustic emission was compared with the strain energy release rate computed from the same portion of the post-peak, stress-displacement curve. The seismic estimate of energy release rate was 5.73 J/m2 from the 110 events and the global estimate was 8.67 J/m2.

Abstract A next-generation hybrid flow meter was developed and field validated for real-time monitoring of drilling mud. This advanced flow meter is meant to measure the multiphase mud flow rate of the mud returning from a well. The sensor integrates differential pressure and thermal dispersion technologies within a compact and rugged architecture designed to provide high accuracy and responsiveness, overcoming the limitations of the industry-standard employed sensor, maintaining its performance during gas influx, rapid mud density variation, and drilling fluid homogeneity with all the most commonly used drilling fluids. During its first field deployment in a deep drilling operation in Kuwait confirmed the sensor confirmed its reliability and early detection capability, enabling the detection of flow variation up to three minutes earlier than conventional Coriolis meters. This feature is particularly relevant for safety improvement and non-productive time reduction since an early kick detection may lead to prompt kick mitigation. The system demonstrates stable performance under severe inhomogeneous flow conditions, supporting uninterrupted flow monitoring and improved decision-making. These results highlight the potential operational and economic benefits led by a highly reliable and responsive sensor for flow monitoring. The robustness of the presented sensor paves the way for integration of advanced flow monitoring into standard and autonomous well-control workflows.

Reservoir-triggered landslides present critical challenges to the sustainable development of hydropower infrastructure in mountainous regions. This study focuses on a representative paleolandslide in the Gushui Hydropower Station reservoir, Upper Lancang River. An advanced fluid-solid coupling model integrating the finite discrete element (FDE) and smoothed particle hydrodynamics (SPH) methods was developed: the FDE method was designed to insert zero-thickness cohesive interface elements between finite elements, enabling simulation of the landslide mass’s deformation, progressive fragmentation, and movement. The SPH method, by contrast, was capable of flexibly handling the evolution of the free surface of water and wave propagation, and accurately simulating the dynamic coupling interaction between the landslide mass and water after the landslide mass enters the water. Simulation results reveal that the landslide fragmentation process consists of three stages: initial disintegration, movement fragmentation, and post-fragmentation. The destabilized landslide mass reaches a peak velocity of 80 m/s, generating impulse waves with a maximum surge velocity of 34 m/s and a maximum run-up of 50 m on the opposing shoreline. Comparative simulations using computational fluid dynamics methods demonstrate that the FDE-SPH framework more accurately captures real-world landslide motion by resolving discrete particle interactions and energy dissipation through fragmentation and collisions.

We present 3D CSEM inversion results from the Campos Basin, offshore Southeast Brazil, using real field data. An initial inversion with a homogeneous half-space model showed good data fit and agreement with well log resistivities. In a second phase, seismic and well log data were incorporated as a priori constraints: logs provided resistivity validation, while seismic data constrained the geometry of salt bodies and reservoirs. This integration significantly improved the resolution of the resistivity model, enhancing the ability to delineate hydrocarbon accumulations in thin post-salt settings. The inversion was performed using the ModEM-ON code, developed at Observatório Nacional. Our findings highlight the value of integrating CSEM with seismic and borehole information to reduce ambiguities and improve subsurface imaging in complex geological settings such as deep-water clastic reservoirs affected by salt tectonics.

Problem, research strategy, and findings An energy-just transition requires research and targeted solutions for energy insecurity. However, national data sets undergirding this work lack the granularity to document energy poverty and physical and behavioral energy insecurity. We present here an index to uncover physical energy insecurity in U.S. regions. Using county tax appraisal district data in Dallas County (TX), the index found 46,422 structures (8% of the total stock) with physical energy deficiencies. We used the index to identify energy-insecure neighborhoods requiring further qualitative research. We then conducted a community-based, qualitative assessment in a Dallas County unincorporated community to illuminate the complexities and heterogeneity of physical, economic, and behavioral insecurities faced by low-income residents at the household level. Takeaway for practice Our study provides three takeaways for practicing planners. First, we provide a method planners can use to identify energy-insecure communities in need of housing and energy upgrading and determine the content of these interventions. Second, our study of a peri-urban unincorporated community demonstrates the inadequacy of national data and the need for mixed-methods assessments of energy insecurity to inform targeted planning interventions in vulnerable communities. Third, we suggest participatory home energy upgrading to comprehensively address the needs of all vulnerable families and overcome difficulties in obtaining funding sources.

The application of differential protection on transformers at industrial facilities improves system reliability by isolating faults fast within the transformer zone, prevents further or catastrophic damage hence extending transformer lifespan, and improves safety by preventing further escalation of faults. This paper will discuss several aspects of applying transformer differential protection from current transformer (CT) selection to setting development and dealing with transformer inrush conditions. This paper will also explore modern advancements to further improve reliability and selectivity of transformer differential protection. Several real-world examples and field case studies will be discussed.

Humid heat stress and heatwaves pose significant risks for living organisms, from humans and wildlife to insects. These threats have wide-ranging health, ecological, and socio-economic impacts that are expected to worsen with climate change. How large-scale climate modes drive the week-to-month variability of humid heat remains poorly understood at the global scale. This limitation hinders the development of accurate forecasts necessary for risk-management measures, notably in the heavily populated and ecologically fragile regions of the tropics and subtropics. With forecast lead times up to several weeks, the Madden-Julian Oscillation (MJO), a global-scale intraseasonal tropical atmospheric disturbance circumnavigating earth in around 30-60 days, provides considerable predictability for weather conditions, and meteorological and oceanic extremes. Here we show that the MJO, and the associated boreal summer intraseasonal oscillation (BSISO), have a significant influence on humid heat and heatwaves over much of the tropics and subtropics across all seasons, both over terrestrial and marine regions. Humid heatwave likelihood can double or halve, depending on the MJO phase, in large areas of the Earth. The MJO/BSISO's influence on wet-bulb temperature is primarily via specific humidity rather than dry-bulb temperature anomalies. In the subtropics and other regions where we typically do not find a strong signal of the convection, we find that intraseasonal anomalies of specific humidity and dry-bulb temperature are influenced by horizontal advection in the planetary boundary layer. Particularly in the subtropics where advection of the climatological moisture and temperature gradient by MJO-related anomalous winds is an important term.

Climate change is forcing ports transformation. First, they must tackle carbon emissions and engage in their own energy transition. As big energy and fossil fuels consumers, ports can test and demonstrate the viability of low-carbon energy solutions. Second, the effects of climate change on weather conditions must be anticipated and addressed. Sea level rise, higher waves and stronger winds will increase the loads on ports infrastructures. Therefore, new protections might be required, and existing structures need to be reinforced. Based on these needs, WaveOp* has developed since 2019 the technology DIKWE: a breakwater structure integrating a wave energy convertor. The system is split into modules, each one being equipped with a flap whose axis is on top and oscillating under the action of waves. The movement of the flap is converted into hydraulic pressure, and then into electricity. The technological development of the solution was carried out together with the French scientific institute IFREMER. This scientific collaboration demonstrated the high energy conversion performances of the technology through the installation and study of a prototype in Saint-Anne-du-Portzic (Brittany, France) between May 2022 and May 2023 [Le Boulluec et al, 2024]. The technology has been developed to address the different configurations faced by ports: it can either be designed as a new independent structure offering an additional protection to the harbour or designed as a reinforcement of an existing breakwater. A DIKWE device installed in front of or integrated into an existing breakwater acts as a buffer to wave loads. Flume tests were carried out in June 2024 in the Laboratoire Ondes et Milieux Complexes in Le Havre, France (LOMC) to characterize the impact of DIKWE devices on the protective functions of an existing breakwater. Different integration solutions are modelled at a 1:35 scale and tested under extreme sea states for varying water depths and hydrodynamic forcings. In total XXX tests are performed. They are compared to the reference situation of the bare breakwater. Damage is calculated to measure the impact of the device on the structural behaviour of the existing breakwater. Overtopping is measured to estimate the benefit brought by the device on its hydraulic performance. In addition, fluid dynamics inside one of the module and the flap’s motion are recorded. The aim of this paper is to expose the methodology and the results of the tests. Significant reductions in damage and overtopping are shown for the three integration solutions tested. The energy efficiency of the technology was already established in 2022 [Le Boulluec et al, 2024], this present set of tests demonstrates the reinforcement capacity of the system on an existing structure. The installation of a scale 1:1 demonstrator composed of 3 modules and used as a reinforcement solution is planned for summer 2025 on the French coastline. * WaveOp is a joint venture company cocreated by the Groupe Legendre and Geps Techno

Abstract Sub‐Plinian eruptions often repeat at short intervals, and the magma discharge rate during these eruptions changes. The mechanism that controls the variation in discharge rate remains unclear; however, its understanding is essential for predicting the evolution of explosive eruptions and mitigating disasters. Here, we used petrological methods to investigate the magma ascent processes during the 1977 eruption of Usu volcano, which included four sub‐Plinian eruptions and two relatively small pumice‐rich eruptions. The water content of the melt inclusions in the first sub‐Plinian eruption indicated a pressure of 100–125 MPa under the assumption of water saturation. From the second to fourth sub‐Plinian eruptions, the minimum water content gradually decreased. The crystal size distributions of plagioclase microlites in the groundmass show large variations in small size (<1 μm), and these small crystals are inferred to crystallize at low pressure (<40 MPa), confirmed by decompression‐induced crystallization experiments. Based on these observations, we inferred the following scenario: the magma in the first sub‐Plinian eruption ascended from the magma reservoir at a depth of ∼4 km; however, the magma stagnated in a shallow conduit and then ascended to the surface during the second to fourth sub‐Plinian eruptions. Moreover, the position of the magma head in the conduit gradually became shallower. The results of this study indicate that the evolution of explosive eruptions during the 1977 eruption of Usu volcano originated from the processes and conditions of both the magma reservoir and the shallow parts of the conduit.