scholarly journals Remote Sensing of Aerated Flows at Large Dams: Proof of Concept

2021 ◽  
Vol 13 (14) ◽  
pp. 2836
Author(s):  
Matthias Kramer ◽  
Stefan Felder
Keyword(s):  
Free Surface ◽  
Citizen Science ◽  
Scale Effects ◽  
Free Surface Flows ◽  
Design Guidelines ◽  
Full Scale ◽  
Stepped Spillway ◽  
Proof Of Concept ◽  
Science Data ◽  
Validation Data

Dams are important for flood mitigation, water supply, and hydroelectricity. Every dam has a water conveyance structure, such as a spillway, to safely release extreme floods when needed. The flows down spillways are often self-aerated and spillway design has typically been investigated in laboratory experiments, which is due to limitations in suitable full scale flow measurement instrumentation and safety considerations. Prototype measurements of aerated flows are urgently needed to quantify potential scale effects and to provide missing validation data for design guidelines and numerical simulations. Herein, an image-based analysis of free-surface flows on a stepped spillway was conducted from a top-view perspective at laboratory scale (fixed camera installation) and prototype scale (drone footage). The drone videos were obtained from citizen science data. Analyses allowed to remotely estimate the location of the inception point of free-surface aeration, air–water surface velocities, and their fluctuations, as well as the residual energy at the downstream end of the chute. The laboratory results were successfully validated against intrusive phase-detection probe data, while the prototype observations provided proof of concept at full scale. This study highlights the feasibility of image-based measurements at prototype spillways. It demonstrates how citizen science data can be used to advance our understanding of real world air–water flow processes and lays the foundations for the remote collection of long-missing prototype data.

Self-Aeration Modelling Using a Sub-Grid Volume-Of-Fluid Model

2017 ◽  
Vol 18 (7-8) ◽  
pp. 559-574 ◽  
Author(s):  
Pedro Lopes ◽  
Jorge Leandro ◽  
Rita F. Carvalho
Keyword(s):  
Free Surface ◽  
Source Term ◽  
Air Entrainment ◽  
Volume Of Fluid ◽  
Free Surface Flows ◽  
Stepped Spillway ◽  
Main Concern ◽  
Advection Diffusion Equation ◽  
Computational Performance ◽  
Good Agreement

AbstractThe accurate prediction of self-aerated flow is not always easy to obtain, particularly if the computational performance is the main concern. Two-fluid formulation is suitable to simulate the dispersed air in a continuous water phase (e.g. bubbly flows) in a fine mesh, whereas the interface tracking methods are used for sharp interfaces with two continuous and contiguous phases (e.g. free-surface flows). Several approaches have emerged to combine both methods; however all found a gap in the transition between resolved and unresolved scales of air at the interface. Including a source term that predicts the self-aeration process is viewed as a promising step to overcome such difficulty. In this work, we added to the volume-of-fluid formulation an extra advection-diffusion equation connected to a source of air at the free surface to simulate the dispersed bubble phase. One-way coupling and two-way coupling versions of this model are tested along with sensitivity tests to show the accuracy of the new source term that does not require calibration. The location of the aeration is analysed and investigated. Results are obtained in terms of free-surface flow depths, air–concentration profiles and velocity fields and compared to experimental data acquired in a scaled stepped spillway model with good agreement. The free-surface given by the air-entrainment model is in good agreement in both non-aerated and aerated zone of the spillway.

scholarly journals Experiences from the Danish Fungal Atlas: Linking mushrooming, nature conservation and primary biodiversity research 

2021 ◽  
Vol 5 ◽  
Author(s):  
Jacob Heilmann-Clausen ◽  
Tobias Frøslev ◽  
Jens Petersen ◽  
Thomas Læssøe ◽  
Thomas Jeppesen
Keyword(s):  
Nature Conservation ◽  
Dna Sequencing ◽  
Citizen Science ◽  
High Throughput Sequencing ◽  
Low Cost ◽  
Mobile App ◽  
Science Data ◽  
Global Biodiversity Information Facility ◽  
Validation Data ◽  
Species Discovery

The Danish Fungal Atlas is a citizen science project launched in 2009 in collaboration among the University of Copenhagen, Mycokey and the Danish Mycological Society. The associated database now holds almost 1 million fungal records, contributed by more than 3000 recorders. The records represent more than 8000 fungal species, of which several hundred have been recorded as new to Denmark during the project. In addition several species have been described as new to science. Data are syncronized with the Global Biodiversity Information Facility (GBIF) on a weekly basis, and is hence freely available for research and nature conservation. Data have been used for systematic conservation planning in Denmark, and several research papers have used data to explore subjects such as host selection in wood-inhabiting fungi (Heilmann‐Clausen et al. 2016), recording bias in citizen science (Geldmann et al. 2016), fungal traits (Krah et al. 2019), biodiversity patterns (e.g. Andrew et al. 2018), and species discovery (Heilmann-Clausen et al. 2019). The project database is designed to faciliate direct interactions and communication among volunteers. The validation of submitted records is interactive and combines species-specific smart filters, user credibility, and expert tools to secure the highest possible data credibility. In 2019, an AI (artificial intelligence) trained species identification tool was launched along with a new mobile app, enabling users to identify and record species directly in the field (Sulc et al. 2020). At the same time, DNA sequencing was tested as an option to test difficult identifications, and in 2021 a high-throughput sequencing facility was developed to allow DNA sequencing of hundreds of fungal collections at a low cost. The presentation will give details on data validation, data use and how we have worked with cultivation of volunteers to provide a truly coherent model for collaboration on mushroom citizen science.

scholarly journals Citizen science data suggest that a novel rig improves landing rate and reduces injury and handling time in recreational angling with artificial lures in Baltic pike (Esox lucius)

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4744
Author(s):  
Jens Jakob Bursell ◽  
Robert Arlinghaus
Keyword(s):  
Observational Data ◽  
Citizen Science ◽  
Experimental Studies ◽  
Handling Time ◽  
Esox Lucius ◽  
The Novel ◽  
Proof Of Concept ◽  
Science Data ◽  
Top Predators ◽  
Recreational Angling

The optimal terminal gear in hook-and-line recreational fishing maximizes landing rates and minimizes injury to the fish because some fish will be released after capture. We designed a novel rig configuration in artificial lure fishing for top predators and examined its effectiveness in angling for Baltic northern pike (Esox lucius) using a citizen science approach based on observational data collected from volunteer anglers in the field. The novel rig included two changes to traditional rig designs common to artificial lure angling. First, hooks were mounted in a way giving better hook exposure and eliminating lever-arm effects from the lure to the hooks once a fish is hooked. This construction allowed the second change, being a shift to hooks 4–5 sizes smaller than those used on traditional hook mounts. We analysed observational data collected by volunteer anglers using either the novel rig or a standard rig mount in two types of artificial lures (softbait and hardbait) of the same size (about 17 cm). UsingN = 768 pike contacts as input data, we showed the landing rates of pike targeted with artificial lures significantly and substantially increased from 45% with normal-rigs to 85% when the same lure types were fished with the novel rig configuration. Lure type and water temperature had no effects on landing rates. Moreover, hardbaits on normal-rigs produced significantly more injury, bleeding and elevated unhooking time compared to fish captured on hardbaits with release-rigs. We conclude that simple changes to traditional hook sizes and mounts in lure fishing may benefit both anglers and the fishes that are to be released and that citizen science projects with volunteer anglers are able to provide good data in proof-of-concept studies. Further experimental studies are needed to differentiate hook size from hook mount effects because both variables were confounded in the results of the observational data presented here.

scholarly journals Citizen science data suggest that a novel rig improves landing rate and reduces injury and handling time in recreational angling with artificial lures in Baltic pike (Esox lucius)

2018 ◽  
Author(s):  
Jens Jakob Bursell ◽  
Robert Arlinghaus
Keyword(s):  
Observational Data ◽  
Citizen Science ◽  
Experimental Studies ◽  
Handling Time ◽  
Esox Lucius ◽  
The Novel ◽  
Proof Of Concept ◽  
Science Data ◽  
Top Predators ◽  
Recreational Angling

The optimal terminal gear in hook-and-line recreational fishing maximizes landing rates and minimizes injury to the fish because some fish will be released after capture. We designed a novel rig configuration in artificial lure fishing for top predators and examined its effectiveness in angling for Baltic northern pike (Esox lucius ) using a citizen science approach based on observational data collected from volunteer anglers in the field. The novel rig included two changes to traditional rig designs common to artificial lure angling. First, hooks were mounted in a way giving better hook exposure and eliminating lever-arm effects from the lure to the hooks once a fish is hooked. This construction allowed the second change, being a shift to hooks 4-5 sizes smaller than those used on traditional hook mounts. We analysed observational data collected by volunteer anglers using either the novel rig or a standard rig mount in two types of artificial lures (softbait and hardbait) of the same size (about 17 cm). Using N = 768 pike contacts as input data, we showed the landing rates of pike targeted with artificial lures significantly and substantially increased from 45 % with normal-rigs to 85 % when the same lure types were fished with the novel rig configuration. Lure type and Water temperature had no effects on landing rates. Moreover, hardbaits on normal-rigs produced significantly more injury, bleeding and elevated unhooking time compared to fish captured on hardbaits with release-rigs. We conclude that simple changes to traditional hook sizes and mounts in lure fishing may benefit both anglers and the fishes that are to be released and that citizen science projects with volunteer anglers are able to provide good data in proof-of-concept studies. Further experimental studies are needed to differentiate hook size from hook mount effects because both variables were confounded in the results of the observational data presented here.

scholarly journals Citizen science data suggest that a novel rig improves landing rate and reduces injury and handling time in recreational angling with artificial lures in Baltic pike (Esox lucius)

2018 ◽  
Author(s):  
Jens Jakob Bursell ◽  
Robert Arlinghaus
Keyword(s):  
Observational Data ◽  
Citizen Science ◽  
Experimental Studies ◽  
Handling Time ◽  
Esox Lucius ◽  
The Novel ◽  
Proof Of Concept ◽  
Science Data ◽  
Top Predators ◽  
Recreational Angling

The optimal terminal gear in hook-and-line recreational fishing maximizes landing rates and minimizes injury to the fish because some fish will be released after capture. We designed a novel rig configuration in artificial lure fishing for top predators and examined its effectiveness in angling for Baltic northern pike (Esox lucius ) using a citizen science approach based on observational data collected from volunteer anglers in the field. The novel rig included two changes to traditional rig designs common to artificial lure angling. First, hooks were mounted in a way giving better hook exposure and eliminating lever-arm effects from the lure to the hooks once a fish is hooked. This construction allowed the second change, being a shift to hooks 4-5 sizes smaller than those used on traditional hook mounts. We analysed observational data collected by volunteer anglers using either the novel rig or a standard rig mount in two types of artificial lures (softbait and hardbait) of the same size (about 17 cm). Using N = 768 pike contacts as input data, we showed the landing rates of pike targeted with artificial lures significantly and substantially increased from 45 % with normal-rigs to 85 % when the same lure types were fished with the novel rig configuration. Lure type and Water temperature had no effects on landing rates. Moreover, hardbaits on normal-rigs produced significantly more injury, bleeding and elevated unhooking time compared to fish captured on hardbaits with release-rigs. We conclude that simple changes to traditional hook sizes and mounts in lure fishing may benefit both anglers and the fishes that are to be released and that citizen science projects with volunteer anglers are able to provide good data in proof-of-concept studies. Further experimental studies are needed to differentiate hook size from hook mount effects because both variables were confounded in the results of the observational data presented here.

scholarly journals Citizen science data suggest a novel rig improves landing rate and reduces injury and handling time in recreational angling with artificial lures in Baltic pike (Esox lucius)

2018 ◽  
Author(s):  
Jens Jakob Bursell ◽  
Robert Arlinghaus
Keyword(s):  
Observational Data ◽  
Citizen Science ◽  
Handling Time ◽  
Esox Lucius ◽  
Recreational Fishing ◽  
The Novel ◽  
Proof Of Concept ◽  
Science Data ◽  
Top Predators ◽  
Recreational Angling

The optimal terminal gear in hook-and-line recreational fishing maximizes landing rates and minimizes injury to the fish because some fish will be released after capture. We designed a novel rig configuration in artificial lure fishing for top predators and examined its effectiveness in angling for Baltic northern pike (Esox lucius ) using a citizen science approach based on observational data collected from volunteer anglers in the field. The novel rig included two changes to traditional rig designs common to artificial lure angling. First, the hooks were mounted in a way that eliminates lever-arm effects from the lure to the hooks once a fish is hooked. Second, the hook sizes used on the novel rig were 4-5 hook sizes smaller than on traditional lures. We analysed observational data collected by volunteer anglers using either the novel rig or a standard rig mount in two types of artificial lures (softbait and hardbait) of the same size (about 17 cm). Using N = 768 pike contacts as input data, we show the landing rates of pike targeted with artificial lures significantly and substantially increased from 45 % with normal-rigs to 85 % when the same lure types were fished with the novel rig configuration. Lure type and water temperature had no effects on landing rates. Moreover, hardbaits on normal-rigs produced significantly more injury, bleeding and elevated unhooking time compared to fish captured on hardbaits with release-rigs. We conclude that simple changes to traditional hook mounts in lure fishing may benefit both anglers and the fishes that are to be released and that citizen science projects with volunteer anglers are able to provide good data in proof-of-concept studies. Further experimental study is needed to differentiate hook size from hook mount effects because both variables were confounded in the results of the observational data presented here.

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