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A distributed-temperature-sensing-based soil temperature profiler
No full textStorage change in heat in the soil is one of the main components of the energy balance and is essential in studying the land-Atmosphere heat exchange. However, its measurement proves to be difficult due to (vertical) soil heterogeneity and sensors easily disturbing the soil. Improvements in the precision and resolution of distributed temperature sensing (DTS) equipment has resulted in its widespread use in geoscientific studies. Multiple studies have shown the added value of spatially distributed measurements of soil temperature and soil heat flux. However, due to the spatial resolution of DTS measurements (g1/430gcm), soil temperature measurements with DTS have generally been restricted to (horizontal) spatially distributed measurements. This paper presents a device which allows high-resolution measurements of (vertical) soil temperature profiles by making use of a 3D-printed screw-like structure. A 50gcm tall probe is created from segments manufactured with fused-filament 3D printing and has a helical groove to guide and protect a fiber-optic (FO) cable. This configuration increases the effective DTS measurement resolution and will inhibit preferential flow along the probe. The probe was tested in the field, where the results were in agreement with the reference sensors. The high vertical resolution of the DTS-measured soil temperature allowed determination of the thermal diffusivity of the soil at a resolution of 2.5gcm, many times better than what is feasible using discrete probes. A future improvement in the design could be the use of integrated reference temperature probes, which would remove the need for DTS calibration baths. This could, in turn, support making the probes "plug and play"into the shelf instruments without the need to splice cables or experience in DTS setup design. The design can also support the integration of an electrical conductor into the probe and allow heat tracer experiments to derive both the heat capacity and the thermal conductivity over depth at high resolution.Atmospheric Remote SensingWater Resource
The ulnar collateral ligament response to valgus stress, repetitive pitching, and elbow muscle contraction in asymptomatic baseball pitchers
No full textBackground: In baseball, repetitive pitching leads to medial elbow injuries, particularly to the ulnar collateral ligament (UCL). To prevent pitchers from UCL injuries, it is important to quantify the response to elbow stress. Repetitive elbow external valgus torque and muscular fatigue induced by repetitive pitching could affect markers of the response, that is, humeroulnar joint gap and UCL morphology. The aims of the study were three-folded: to investigate the effect of (1) exerted handgrip force on the humeroulnar joint gap, (2) repetitive pitching on the humeroulnar joint gap and the UCL morphology, and (3) exerted handgrip force on the humeroulnar joint gap for different levels of elbow valgus stress is different after compared to before repetitive pitching in asymptomatic baseball pitchers. Methods: Medial elbow ultrasound images were collected in 15 asymptomatic male baseball pitchers. Three levels of static elbow valgus stress (0N, 50N, 100N) were applied with a TELOS device before and after repetitive pitching and with or without handgrip force. These images were used to assess the humeroulnar joint gap size and UCL length and thickness. After 110 fastball pitches or when 80% self-perceived fatigue on a VAS scale was reached, participants were instructed to stop throwing. Repeated measures ANOVAs were used to statistically test significant differences. Results: Handgrip force did not significantly affect the humeroulnar joint gap. The UCL thickness and length and the humeroulnar joint gap were also not different after compared to before repetitive pitching. While higher levels of applied valgus stress significantly increased the humeroulnar joint gap (P < .001), this effect was not significantly different in the interaction with handgrip force and repetitive pitching. Conclusion: The humeroulnar joint gap changes for different levels of elbow valgus stress. However, adult baseball pitchers did not respond to elbow stress after a single pitching session with or without submaximal handgrip force in the humeroulnar joint gap and UCL morphology.Biomechatronics & Human-Machine Contro
Insights into the structure of the Mongol-Okhotsk suture zone, Adaatsag ophiolite, and tectonic boundaries of the Central Asian Orogenic Belt (Mongolia) from electrical resistivity imaging and seismic velocity models
No full textThe Mongol-Okhotsk suture and the Adaatsag ophiolite belt are associated with the closure of the Mongol-Okhotsk paleo-ocean and are located within the Central Asian Orogenic Belt (CAOB) and Mongolia. The suture zone is flanked by volcanic-plutonic belts that host significant metallogenic zones, containing deposits of copper and gold. The tectonic evolution of this region is not fully understood and the lithospheric structure has been poorly studied. We analyze magnetotelluric data and generate a model of the electrical resistivity distribution across this region. Whereas the northern segment has a sharp transition from a high-resistivity upper crust to a low-resistivity lower crust, as observed beneath the Hangai Dome, the southern segment does not show this transition. A wide, low-resistivity zone (1–100 Ωm) imaged in the crust and lithospheric mantle is coincident with the Mongol-Okhotsk suture and ophiolite, revealing a clear and significant lithospheric-scale feature. Across the profile, numerous narrow, vertically oriented, low-resistivity features (1–100 Ωm) are spatially associated remarkably well with the proposed boundaries of tectonic domains. These results confirm ideas about the development of the CAOB. Some of these low-resistivity features are beneath the surface locations of large mineral zones, and likely represent fossil fluid pathways. We show congruent seismic velocity models for comparison and the results show a large-scale low-velocity anomaly (decrease of 2%–3%) that correlates with the location of the low-resistivity anomaly below the Mongol-Okhotsk suture. The geophysical results, combined with geological and geochemical data, provide insights into the structure of this region and help shed light on unanswered questions.Applied Geophysics and Petrophysic
Ontwerpen met natuur en landschap voor toekomstbestendige steden: Concevoir avec la nature et le paysage pour des villes à l'épreuve du temps
No full textDuurzame verstedelijking, klimaatadaptatie en biodiversiteitsontwikkeling vragen om een ontwerpaanpak die het landschap als uitgangspunt neemt. In een dergelijke aanpak staat het ontwerpen met natuurlijke en sociaalculturele processen centraal. Naast natuur zijn mensen een belangrijk element van een landschappelijke aanpak. Het landschap verbindt mensen, thema’s en schaalniveaus met de natuurlijke context. Het is de drager van de stad en biedt structuur, ecologische samenhang en variatie, maar is ook flexibel en multifunctioneel.L'urbanisation durable, l'adaptation au climat et le développement de la biodiversité nécessitent une approche de conception qui prend le paysage comme point de départ. Dans une telle approche, la conception intégrant des processus naturels et socioculturels est centrale. Outre la nature, l'être humain est un élément important de l'approche paysagère. Le paysage relie les personnes, les thèmes et les niveaux d'échelle au contexte naturel. Il soutient la ville et assure structure, cohérence et variations écologiques, mais il est également flexible et multifonctionnel.In samenwerking met: Belgische Federatie Groenvoorzieners, De Bloeimeesters en Embuild VlaanderenLandscape Architectur
Waste Houses: Messing up The Netherlands
No full textThe Netherlands has the ambition to transition to a fully circular economy before 2050. Between this future and where we stand now, there is still a large gap. The Netherlands produces 60 million tonnes of waste per year. This fact contains two problems that this project aims to deal with: 1) the heigh of this number in the first place, and 2) that approximately 20% of the waste does not find its way back into the system. In 2020, 7.6 million tonnes of waste was incinerated and 32.7 million tonnes of waste was exported to non-EU countries, where waste often ends up in landfill or is send for incineration with adverse health effects.This project takes the radical stance to stop incineration and export, which means the Netherlands must take responsibility for the waste it produces. For much of the waste that currently follows one of these trajectories, there are no adequate solutions for reuse or recycling. Hence, we designed a system of waste collection, sorting, and storage where materials can be stored in waste houses until they find their way back into the system (problem 1). The piling up of the waste will create awareness of the consequences of unresponsible consumption, affecting the behaviour of people through confrontation (problem 2).The system we design aims to create a disruption of the existing linear system at different levels. The large-scale societal perception of production-consumption-waste generation will slowly change, while the waste houses will create a sense of urgency at the small scale. This will stimulate niche innovations to find innovative solutions to deal with waste that is stored. Our project is thus both an instigator of change and part of the change itself in the transition to the circular economy.If the project is successful, the waste houses will gradually become obsolete as consumption and waste production go down. In the far future, the former waste houses can house different functions, or they can be demolished in a circular way, returning the materials into the resource loop.AR2U086 R&D Studio – Spatial Strategies for the Global MetropolisArchitecture, Urbanism and Building Sciences | Urbanis
Measuring up to Stability: Guidelines towards accurate energy consumption measurement results of Rust benchmarks
No full textIn Sustainable Software Engineering there is a need for tooling and guidelines for developers. In this research we aim to provide such guidelines. We find that for our experimental setup and set of benchmarks 500 samples gives results that are likely stable at a 1% threshold in their Relative Confidence Interval Width. Running benchmarks with a variable CPU clock-speed can lead to higher variability of measurements; as well as initialising benchmarks with random data. Likewise we investigate the effect of the length of benchmarks on their stability but we can not rule out that this is caused by the experiment setup. Lastly we identify control flow statements and code related to memory accesses as potential large influences of instability.Electrical Engineering | Embedded System
The Potential Future Role of Floating Wind Turbines and Airborne Wind Energy Systems in the North Sea Region
No full textExperimental tests and numerical simulation of delamination and fiber breakage in AP-PLY composite laminates
No full textThe behavior of delaminations and fiber breakage resulting from three-point bending test is a major concern in the study of composites. This research focused on analyzing fiber breakage and delaminations in advanced placed ply composite laminates through a series of tests. In order to compare simulation results with the experimental data, the cohesive zone model was implemented for analyzing the damage in the model. The results of the simulation were validated using experimental results. The predicted damage initiation load exhibited an approximate 20% deviation from the actual test loads and the discrepancy stems are analyzed.Aerospace Structures & Computational MechanicsGroup De Breuke
Air entrapment modelling in water supply networks during pipe filling events
No full textIntermittent water supply systems are prone to air entrapments during the pipe filling phase. This work aims to analyse and discuss the numerical results obtained by applying the recently developed AirSWMM model, an extension of SWMM incorporating air phase, to a laboratory network. Experimental data consisting of pressure-head at multiple locations and video recordings of air entrapments are collected in a single loop network with a high point, for different pipe-filling conditions, system layouts and node elevations. Experimental tests have shown that the air entrapment occurred not only at the high point but also throughout the pipe network, creating air pockets with elongated shapes and larger volumes than for single pipes. AirSWWM model with air-entrapment formation, growth and transport is tested in the pipe network, and results are compared with measurements. AirSWWM model can correctly locate large air pockets but underestimates their volume.Education AESanitary Engineerin
Reachability-Based Confidence-Aware Probabilistic Collision Detection in Highway Driving
No full textRisk assessment is a crucial component of collision warning and avoidance systems for intelligent vehicles. Reachability-based formal approaches have been developed to ensure driving safety to accurately detect potential vehicle collisions. However, they suffer from over-conservatism, potentially resulting in false–positive risk events in complicated real-world applications. In this paper, we combine two reachability analysis techniques, a backward reachable set (BRS) and a stochastic forward reachable set (FRS), and propose an integrated probabilistic collision–detection framework for highway driving. Within this framework, we can first use a BRS to formally check whether a two-vehicle interaction is safe; otherwise, a prediction-based stochastic FRS is employed to estimate the collision probability at each future time step. Thus, the framework can not only identify non-risky events with guaranteed safety but also provide accurate collision risk estimation in safety–critical events. To construct the stochastic FRS, we develop a neural network-based acceleration model for surrounding vehicles and further incorporate a confidence-aware dynamic belief to improve the prediction accuracy. Extensive experiments were conducted to validate the performance of the acceleration prediction model based on naturalistic highway driving data. The efficiency and effectiveness of the framework with infused confidence beliefs were tested in both naturalistic and simulated highway scenarios. The proposed risk assessment framework is promising for real-world applications.Learning & Autonomous Contro