Impact of reconfiguration on the flow downstream of a flexible foliated plant

This paper explores the impacts of reconfiguration and leaf morphology on the flow downstream of a flexible foliated plant. 3D acoustic Doppler velocimetry and particle image velocimetry were used to experimentally investigate the hydrodynamic interaction between a foliated plant and the flow, testing two plants with different leaves morphology under different bulk flow velocities. The model vegetation was representative of riparian vegetation species in terms of plants hydrodynamic behavior and leaf to stem area ratio. To explore the effects of the seasonal variability of vegetation on the flow structure, leafless conditions were tested. Reconfiguration resulted in a decrease of the frontal projected area of the plants up to the 80% relative to the undeformed value. Such changes in plant frontal area markedly affected the spatial distributions of mean velocity and turbulence intensities, altering the local exchanges of momentum. At increasing reconfiguration, the different plant morphology influenced the mean and turbulent wake width. The leafless stem exhibited a rigid behavior, with the flow in the wake being comparable to that downstream of a rigid cylinder. The study revealed that the flexibility-induced reconfiguration of plants can markedly affect the local distribution of flow properties in the wake, potentially affecting transport processes at the scale of the plant and its subparts

The 40s Omega-loop plays a critical role in the stability and the alkaline conformational transition of cytochrome c

The structural and redox properties of a non-covalent complex reconstituted upon mixing two non-contiguous fragments of horse cytochrome c, the residues 1 - 38 heme-containing N-fragment with the residues 57 - 104 C-fragment, have been investigated. With respect to native cyt c, the complex lacks a segment of 18 residues, corresponding, in the native protein, to an omega ( W)loop region. The fragment complex shows compact structure, native-like alpha-helix content but a less rigid atomic packing and reduced stability with respect to the native protein. Structural heterogeneity is observed at pH 7.0, involving formation of an axially misligated low-spin species and consequent partial displacement of Met80 from the sixth coordination position of the heme-iron. Spectroscopic data suggest that a lysine ( located in the Met80-containing loop, namely Lys72, Lys73, or Lys79) replaces the methionine residue. The residues 1 - 38/57 - 104 fragment complex shows an unusual biphasic alkaline titration characterized by a low (pK(a1)= 6.72) and a high pK(a)-associated state transition (pK(a2)= 8.56); this behavior differs from that of native cyt c, which shows a monophasic alkaline transition ( pK(a)= 8.9). The data indicate that the 40s Omega-loop plays an important role in the stability of cyt c and in ensuring a correct alkaline conformational transition of the protein

Evaluating the Impact of Nature-Based Solutions: A Handbook for Practitioners

The Handbook aims to provide decision-makers with a comprehensive NBS impact assessment framework, and a robust set of indicators and methodologies to assess impacts of nature-based solutions across 12 societal challenge areas: Climate Resilience; Water Management; Natural and Climate Hazards; Green Space Management; Biodiversity; Air Quality; Place Regeneration; Knowledge and Social Capacity Building for Sustainable Urban Transformation; Participatory Planning and Governance; Social Justice and Social Cohesion; Health and Well-being; New Economic Opportunities and Green Jobs. Indicators have been developed collaboratively by representatives of 17 individual EU-funded NBS projects and collaborating institutions such as the EEA and JRC, as part of the European Taskforce for NBS Impact Assessment, with the four-fold objective of: serving as a reference for relevant EU policies and activities; orient urban practitioners in developing robust impact evaluation frameworks for nature-based solutions at different scales; expand upon the pioneering work of the EKLIPSE framework by providing a comprehensive set of indicators and methodologies; and build the European evidence base regarding NBS impacts. They reflect the state of the art in current scientific research on impacts of nature-based solutions and valid and standardized methods of assessment, as well as the state of play in urban implementation of evaluation frameworks

Acoustic Doppler Velocimetry (ADV) data on flow-vegetation interaction in partly vegetated channels with flexible and rigid vegetation

This dataset contains measurements of 3D instantaneous flow velocity with acoustic Doppler velocimetry (ADV) in partly vegetated channels with natural-like foliated flexible vegetation and with rigid cylinders. Experiments with natural-like vegetation (F experiments) were carried out at the Environmental Hydraulics Lab of Aalto University (Espoo, Finland), while experiments with rigid cylinders (R experiments) were performed at the Laboratory of Hydraulics of University of Naples Federico II (Naples, Italy). Velocity measurements were carried out for steady, fully developed turbulent flows in partly vegetated channels, along mid-depth transversal transects. 3D instantaneous point velocity was measured with ADV at 200 and 100 Hz, for duration of 120 and 240 s, for F and R experiments, respectively. For each test series three conditions were investigated: F1, F2 and F3, with increasing vegetation reconfiguration (for F experiments); and R1, R2 and R3, with decreasing cylinder density (for R experiments). The ADV measurements for each test run and the video recordings of plants motion (for F experiments) are included in this dataset. The detailed description of the laboratory setup, the experimental conditions, the measurement technique, together with additional information on the provided data are included in the data article linked to this dataset (https://doi.org/10.1016/j.dib.2020.106080)

Acoustic Doppler Velocimetry (ADV) data on flow-vegetation interaction in partly vegetated channels with flexible and rigid vegetation

This dataset contains measurements of 3D instantaneous flow velocity with acoustic Doppler velocimetry (ADV) in partly vegetated channels with natural-like foliated flexible vegetation and with rigid cylinders. Experiments with natural-like vegetation (F experiments) were carried out at the Environmental Hydraulics Lab of Aalto University (Espoo, Finland), while experiments with rigid cylinders (R experiments) were performed at the Laboratory of Hydraulics of University of Naples Federico II (Naples, Italy). Velocity measurements were carried out for steady, fully developed turbulent flows in partly vegetated channels, along mid-depth transversal transects. 3D instantaneous point velocity was measured with ADV at 200 and 100 Hz, for duration of 120 and 240 s, for F and R experiments, respectively. For each test series three conditions were investigated: F1, F2 and F3, with increasing vegetation reconfiguration (for F experiments); and R1, R2 and R3, with decreasing cylinder density (for R experiments). The ADV measurements for each test run and the video recordings of plants motion (for F experiments) are included in this dataset. The detailed description of the laboratory setup, the experimental conditions, the measurement technique, together with additional information on the provided data are included in the data article linked to this dataset (https://doi.org/10.1016/j.dib.2020.106080)

Hydrodynamics of sinuous channel with seepage

An experimental investigation was conducted in a sinuous channel to study the hydrodynamics of the channel under two different conditions: (1) no seepage and (2) downward seepage. In particular, the effects on mean and turbulent flow structure has been described. In the two different conditions, three-dimensional flow parameters such as time-averaged velocity, Reynolds shear stress and turbulence intensity shows modifications in their distributions. The presence of helical flow in bends was revealed by the Reynolds stress distribution. Downward seepage allows water to move out from the porous boundaries of the channel in lateral direction. The flow at the interface between the surface water and the groundwater increases with downward seepage. The results can be relevant for the understanding of the hydrodynamics in sinuous natural channels with downward seepage

Impianti oculari di 108 impianti di lenti intraoculari.

Follow-up di 108 impianti intraoculari

Enhancing the Urban Resilience to Flood Risk Through a Decision Support Tool for the LID-BMPs Optimal Design

Urban areas are becoming increasingly susceptible to flooding because of high urbanization levels and changes in the precipitation patterns caused by climate change. The effective management of urban water drainage systems is particularly relevant to control and regulate the runoff impacts. Nevertheless, the mitigation of climate change effects and the adaptation to its impacts call for the implementation of new sustainable strategies and solutions. In this context, a key role can be played by Low Impact Development (LID) technologies of Best Management Practices (BMPs). Such innovative design approaches can lead to more sustainable and effective strategies for urban runoff control. In this paper, a methodology to increase the urban resilience to flooding risk through LID-BMPs is proposed and discussed. A tool for the optimal selection and design of different LID-BMPs is presented. The tool couples GIS processing with hydraulic simulations, constituting a Decision Support System (DSS) based on the meta-heuristic optimization algorithm Harmony Search (HS). The methodology was tested on the case study site of Soccavo, a suburban area in the Municipality of Naples (Italy). Several LID measures, including bio-retention systems, porous pavements, green roofs, were considered. Then, the effectiveness of combining LIDs with grey solutions to carry out hybrid solutions was also assessed. Results showed the capability of the proposed approach in detecting technically and economically viable solutions

Turbulence at water-vegetation interface in open channel flow: Experiments with natural-like plants

Riparian shrubs and trees present a complex, seasonally variable morphology, with flexible stems and leaves efficiently adapting to the flow forcing (reconfiguration). The aim of this paper is to investigate how foliage and reconfiguration affect the flow and mixing in a partly vegetated channel. Specific attention was placed on the velocity statistics, onset and coherence of turbulent structures, and lateral momentum transport at the horizontal interface between vegetation and open water. The experimental flume arrangement was novel in that it allowed investigating the lateral shear layer induced by flexible riparian plants. The natural-like vegetation consisted of emergent woody plants and a grassy understory, with density, morphology and reconfiguration behavior comparable to those found in real riparian areas. Investigations were conducted under foliated and leafless conditions to determine the seasonality effects. The mean and turbulent flow structure was determined with acoustic Doppler velocimetry, and dynamic plant motions were investigated from video footage. The presence of foliage enhanced the drag discontinuity at the interface, resulting in more pronounced velocity gradients between the vegetated and open areas compared to the leafless conditions. Foliation induced stronger shear layer-scale mixing, whereas, under leafless conditions, the local mixing induced by stems was more important. The reconfiguration decreased the coherence of the two-dimensional large-scale vortices at the interface while their characteristic frequency was consistent with the canonical mixing layer theory. Our results indicated that shear layer dynamics in partly vegetated channels was influenced strongly by morphology and reconfiguration of complex plants, with more efficient lateral momentum transport at the interface in the foliated conditions than previously reported for shear layers induced by simpler vegetation