198 research outputs found
Effects of microplastics on evaporation dynamics in porous media
No full textMicroplastics (MPs) pollution is an emerging threat to soil ecosystems. The present study aims to investigate the impacts of MPs on soil water evaporation dynamics and patterns. Two series of laboratory experiments were conducted using sand particles and clay mixed with different MPs to investigate how evaporation dynamics and patterns are influenced by the presence of MPs. Quartz sand including 0, 0.75, 1.5, and 4.5% of Polyethylene (PE) and Polyvinylchloride (PVC) were used to evaluate MPs effects on evaporation rates while bentonite mixed with sand and 0, 0.75, 1.5, 4.5, 6, 8, and 10% of PE and PVC were used to investigate evaporation-induced cracking patterns. The experiments were conducted under controlled laboratory conditions in a climate chamber at constant ambient temperature. Our results suggest that the addition of MPs led to more water evaporation compared to the samples without MPs. Microscopic imaging and analysis enabled us to evaluate the possible MPs effects on the modification of soil characteristics and pore structure affecting the evaporation behavior. Moreover, although increasing MPs concentrations appeared to induce only minor effects on the crack morphology formed as a result of evaporation from the mixture of sand and bentonite, the type of MPs (PE vs PVC) had more notable effects on the drying-induced cracking patterns. The reported experimental data and analysis extend our physical understanding of the parameters influencing soil water evaporation in the presence of MPs
The complementary relationship between actual and potential evaporation for spatially heterogeneous surfaces
No full textThe Complementary Relationship (CR) between actual and potential evaporation offers an attractive framework for estimating actual evaporation of drying land surfaces from simple meteorological measurements. Land surfaces are often heterogeneous with variable soil types, land cover, and local hydrologic conditions that give rise to spatially variable evaporation dynamics. The main aim is to incorporate effects of spatial heterogeneities on estimates of actual evaporation in the CR framework. The study extends the physically based approach of Aminzadeh et al. (2016) and proposes upscaling schemes for land-atmosphere interactions affecting reference evaporation from heterogeneous surfaces comprised of vegetation and bare soil patches. For small-scale surface heterogeneity relative to the extent of convective boundary layer (CBL), area-averaged atmospheric boundary conditions were imposed over the domain of interest to integrate contributions from patches with different dynamics. For large-scale heterogeneity (large patches relative to the scale of the mean CBL), fluxes from each patch were weighted by their respective areas. Preliminary results are in reasonable agreement with available field measurements and illustrate various effects of heterogeneous surface evaporative fluxes on the CR response. The results also highlight hidden dynamics not captured by standard CR, such as ability of vegetated patches to support steady evaporative fluxes until the onset of water stress while bare soil has already dried out. The study provides new insights into the roles of different vegetation types, land cover fraction, and atmospheric conditions on regional CR behavior hence advancing predictive capabilities of actual evapotranspiration from spatially heterogeneous land surfaces.Funding by the Swiss National Science Foundation (200021–113442) is gratefully acknowledged. The authors greatly appreciate the generous assistance of Matthew McCabe and Bruno Aragon Solorio (KAUST) in providing data from the eddy covariance station in the Tawdeehiya farm (Saudi Arabia), and the insightful comments provided by the Associate Editor and three anonymous reviewers. Results of this study made use of eddy covariance data from Oensingen (Switzerland) and Wetzstein (Germany) acquired by the FLUXNET community; we are grateful for accessing to these data sets
Global distribution of small reservoirs and their role in surface water storage
No full textSmall on-farm reservoirs play a vital role in sustaining irrigation and livestock water demands, particularly in regions facing acute water scarcity (Aminzadeh et al., 2024). However, comprehensive understanding of their global distribution and contribution to local water budgeting and management remains limited. This research leverages high-resolution satellite data from Sentinel 1 and Sentinel 2 to develop a global database of small agricultural reservoirs (<0.1 km2) across geographic and climatic zones. Machine learning algorithms are employed to improve the accuracy of reservoir detection from satellite imagery. In addition to mapping the spatial and temporal distribution of these reservoirs, we estimate their storage capacity by correlating surface area and depth metrics. The study enables monitoring of surface water storages across scales thus offering critical insights into the role of small reservoirs in water budgeting and accounting, particularly in water-stressed regions of the world
Evaporation dynamics and energy partitioning over drying porous surfaces - from pores to landscapes
No full text
Insignificant but overlooked : evaporative losses from small reservoirs in southern Europe
No full textThe application of agricultural ponds and small engineered impoundments (often < 0.1 km2 area) is growing globally to support livestock, irrigation, and local municipal and industrial demands during dry spells. However, evaporation diminishes the storage efficiency of these popular but often un-inventoried resources. This study provides a reliable framework for estimating global abundance of small reservoirs and associated evaporative hotspots under different climate change scenarios serving as a basis for future water management and planning. To show the applicability of the proposed method and the utility of the insights it provides, we use satellite data to identify spatio-temporal distribution of small reservoirs (~0.001 to 0.1 km2 area) in southern Europe (Italy, Spain, and Portugal) where irrigation heavily depends on water storage in agricultural ponds. While current estimates of evaporative water losses from small reservoirs often rely on pan measurements or Penman-type approaches with locally calibrated heat and mass transfer coefficients, we employ a physically-based model [Aminzadeh et al., 2018] that accounts for inherent reservoir characteristics (e.g., depth and light attenuation), and radiative energy storage within the water body to quantify energy balance and evaporation dynamics from small water reservoirs. Our preliminary results indicate that cumulative area of small reservoirs in the study area has increased from 518 km2 in 2000 to 614 km2 in 2020 (18.5% increase) with cumulative evaporative losses that may exceed 400 Mm3 during warm months (April to September). Although the estimated evaporative water loss looks negligible relative to the annual agricultural water use (< 2%), its significance could be gauged by societal impacts in these regions with chronic water stress problems or the cost of alternate water sources (e.g., desalinated water)
Can the complementary relationship between actual and potential evaporation be used to quantify heatwaves?
No full textISSN:1029-7006ISSN:1607-7962ISSN:1607-796
Home-Based Virtual Reality for Upper Limb Stroke Rehabilitation: Supervised vs. Unsupervised Approaches – A Systematic Review with Meta-Analysis of Unsupervised Interventions
No full textThis systematic review and meta-analysis aims to evaluate the effectiveness of **unsupervised home-based virtual reality (VR)** interventions compared to **active home exercise programs** on upper limb functional recovery in adult stroke survivors (≥18 years).
**Purpose**:
Upper limb impairment affects 55–85% of stroke survivors and significantly limits activities of daily living. Home-based VR has been promoted as a cost-effective, accessible, and motivating rehabilitation tool to increase therapy dose post-discharge. However, existing evidence is conflicting, particularly when VR is compared to dose-matched active controls without therapist supervision. This review addresses a critical gap by focusing exclusively on **unsupervised** VR interventions to determine whether the technology itself confers additional benefit beyond structured exercise.
**Methods**:
A comprehensive search was conducted in PubMed, Scopus, and Web of Science from inception to October 2025. Only randomized controlled trials (RCTs) involving home-based VR (with or without exergaming), adult stroke survivors, and quantitative upper limb outcomes (e.g., Fugl-Meyer Assessment–Upper Extremity, Action Research Arm Test) were included. Two independent reviewers performed study selection, data extraction, and risk of bias assessment using the Cochrane RoB 2 tool. A random-effects meta-analysis was conducted on homogeneous studies (n=2) using standardized mean difference (SMD). Heterogeneity was assessed with I², and certainty of evidence was rated using GRADE. A narrative synthesis was performed for clinically heterogeneous studies.
**Results (Completed Review)**:
Seven RCTs (n=414 participants) were included. The meta-analysis of two large, homogeneous trials (n=291) showed no significant difference between unsupervised home-based VR and active home exercise (SMD = -0.06; 95% CI: -0.29 to 0.17; P = 0.62; I² = 0%). Narrative synthesis revealed positive effects in studies incorporating remote therapist supervision (telerehabilitation), but not in unsupervised settings. Risk of bias was high across all studies due to lack of blinding. GRADE certainty was rated **Very Low**.
**Expected/Observed Outcomes**:
- No superiority of unsupervised home-based VR over active home exercise.
- Therapist supervision appears to be a key determinant of efficacy, not the VR technology per se.
- Future high-quality RCTs should compare supervised vs. unsupervised models and assess long-term adherence and cost-effectiveness.
**Registration Note**:
This protocol was registered **retrospectively** in OSF Registries due to initial oversight as a novice researcher. A detailed a priori protocol was followed throughout to minimize bias. The full review has been completed and is under peer review.
**Keywords**: stroke, virtual reality, home-based rehabilitation, upper extremity, systematic review, meta-analysi
Damage accumulation analysis of cfrp cross-ply laminates under different tensile loading rates
No full textThis paper investigates the loading rate effect on both mechanical properties and damage accumulation process of [0°2/90°4]S carbon fiber-polymer laminates under tensile loading. In-situ edge observations, Acoustic Emission and Digital Image Correlation techniques were utilized simultaneously to monitor the state of damage in real time. Results showed that the axial modulus and strength were less sensitive to loading rates than failure strain, which increased with the decrease of the loading rate. In the viewpoint of damage accumulation process, high density and uniform distribution of transverse matrix cracks, and H-shape crack patterns, incorporating inter-laminar cracks, were more likely to occur at low loading rates while variable crack spacing occurred at higher rates. When loading rates were lower than a certain level, maximum transverse matrix crack density decreased slightly due to the restriction of relatively widely generated inter-laminar cracks. Furthermore, the cumulative acoustic emission energy of low-frequency signals was linearly correlated to transverse matrix crack density, providing a promising way to quantify crack accumulation in real time. Finally, spatial consistence was observed between transverse matrix cracks at edges and stress concentrations at the exterior 0° ply, and the peaks of axial strain at local concentration regions locate either near the newest cracks or at the place with minimum crack spacing.Structural Integrity & Composite
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