Aug 13

The response of common minnows, Phoxinus phoxinus, to visual cues under flowing and static water conditions

The response of common minnows, Phoxinus phoxinus, to visual cues under flowing and static water conditions

James Miles, Andrew Vowles, Paul Kemp

The International Centre for Ecohydraulics Research, Faculty of Engineering and Physical Sciences, University of Southampton

Animal Behaviour

Volume 179, September 2021, Pages 289-296
 Available online 13 August 2021.
Animal Behaviour

Highlights

 

Minnows associated strongly with static visual cues (vertical stripes).

Association increased in flowing water and decreased when in a group.

Visual cues likely provide a reference point from which to control position.

Strong individual association may reflect a sheltering or refuge seeking response.

Reduced use of visual cues by groups may reflect security or information transfer.

While fixed visual cues provide reliable reference points for navigation in static water, it remains unclear whether fish energetically benefit from their presence in flowing water. Furthermore, benefits of visual feedback from fixed sources may be less for group members that can gain additional information from others. Using an open-channel flume, this study investigated how the response of fish to stationary visual stimuli is influenced by flow and group membership under two treatments: vertical black and white stripes placed on (1) both side walls of the channel or (2) one side wall only compared to a control where both walls were uniform white. The responses were compared in flowing and static water, and between individuals and groups of five. Fish exhibited a positive affiliation for the visual cues, travelling more slowly and spending more time closer to the striped walls. Fish were more edge oriented under flowing conditions, presumably utilizing the lower velocities at the wall boundary to reduce energy expenditure. When only one wall presented visual cues, individual fish spent more time associated with it in flowing water, suggesting some energetic benefit in lotic conditions. This may result from a greater ability to maintain station or control position relative to a reference point and/or the use of visual stimuli as a proxy indicator of physical structure which may provide drag-reducing refuge. A lesser association with the striped wall in static water suggests that visual cues provide other nonhydrodynamic benefits, such as physical refuge from predators or opportunities for crypsis. Conversely, less association of shoals with the striped walls may reflect a greater dependence on information provided by conspecifics or increased security associated with being part of a group. This study indicates that fixed visual cues likely provide several benefits that vary depending on flow and group membership.

Keywords

collective behaviour
environmental stimulus
fish
group behaviour
optic flow

Jul 30

Fatigue crack growth in IN718/316L multi-materials layered structures fabricated by laser powder bed fusion

Fatigue crack growth in IN718/316L multi-materials layered structures fabricated by laser powder bed fusion

M.S.Duval-ChaneacabN.GaoaR.H.U.KhancM.GilesaK.GeorgilasbX.ZhaoaP.A.S.Reeda

Materials Research Group, Faculty of Engineering and Physical Sciences, University of Southampton
b
NSIRC, TWI Ltd. Cambridge
c
TWI Ltd., Cambridge

International Journal of Fatigue

Volume 152, November 2021, 106454 Available online 30 July 2021.

Highlights

Layered specimen of 316L and IN718 has been fabricated by multiple material additive manufacturing.

The crack propagation mechanism was investigated under three point bending, and recorded via direct current potential drop method, then analysed via correlation between the stress intensity factor and the final fracture surface.

Mechanisms of shielding and antishielding in the crack propagation were investigated through a 4 alternated layer specimen.

Relation between the as-built microstructure and the tensile properties of each alloy was used to put in perspective the results obtained in the different crack propagation tests.

Abstract

Multi-materials additive manufacturing (MMAM) allows the functional optimisation of components by tailoring the addition of alloys at different design locations in a single operation. In this study Laser Powder Bed Fusion (L-PBF) technique was used to manufacture layered specimens combining IN718 and 316L materials. The microstructure and mechanical properties were studied by scanning electron microscopy (SEM), tensile, micro and nanohardness testing. The fatigue tests were performed to determine the crack propagation process through multi-layer specimens in the as-built (AB) state.

Keywords

Multi-materials
Additive manufacturing (AM)
Interface
Fatigue analysis
Crack growth rate

    Jul 22

    Life after the CDT

    The CDT SIS and SIC seminar on Thursday 22nd July 2021.

    Presentation by Diego Panici, Post doctoral researcher at the University of Exeter.

    Diego was a PGR in the first cohort of CDT SIS students starting in 2014 and he graduated in 2019 with his iPhD. This presentation shows the development of his research work from the first summer project through PhD research into the start his academic career. His interest in debris jams at bridge piers in rivers has developed and he told us that the work he did and support he received in the CDT SIS has shaped the research he is doing now.

    CDT-SIS presentation – Diego Panici

    CDT SIS research images

     

    Jul 05

    Understanding fish-hydrodynamic interactions within Cylindrical Bristle Cluster arrays to improve passage over sloped weirs

    Understanding fish-hydrodynamic interactions within Cylindrical Bristle Cluster arrays to improve passage over sloped weirs

    Daniella Montali-Ashworth

    The International Centre for Ecohydraulics Research, School of Engineering, Faculty of Engineering and Physical Sciences, Southampton Boldrewood Innovation Campus University of Southampton, Southampton,
    Received 03 Dec 2020, Accepted 11 May 2021, Published online: 05 Jul 2021

    Anthropogenic infrastructure in rivers (e.g. culverts, dams and weirs) can block the movements of fish and negatively impact their communities. Recent research has shown that fish passage at such barriers can be improved through the use of cylindrical bristle cluster (CBC) arrays. The relationship between the hydrodynamic environment created by different CBC array geometries and passage efficiency, the number of fish that passed as a percentage of those that attempted to do so, and swimming behaviour of a native wide spread European cyprinid species, the roach (Rutilus rutilus), was investigated. Passage efficiency was a function of cluster diameter and spacing; efficiency was highest (>80%) when the ratio of lateral cluster spacing (centre to centre) (Sc) to diameter was less than 5. Fish exhibited a range of swimming behaviours while manoeuvring through the CBC array to ascend the weir, the most common of which was zigzagging between two lines of clusters. Additionally, fish utilised lower velocity areas when swimming through a CBC array, often combining different swimming behaviours to successfully navigate at burst speeds. Fish passage efficiency can be improved by increasing the size of the wake behind clusters and the overall hydraulic resistance created within the array while ensuring sufficient space is available for fish to manoeuvre.

    Keywords: Multi Species, fish passage, swimming behaviour, roach

    Jul 01

    SHAASAN Webinar 1 – Sustainable Hydropower in South America

    SHAASAN Webinar I – Sustainable Hydropower in South America hosted by the University of Concepcion and University of Southampton.

    14th July 2021 2.00pm BST

    Hector Vera- Alcaraz, Paul Kemp and Oscar Link introduced the SHAASAN network in this webinar hosted by the University of Concepcion and University of Southampton.


    This event was held online, a meeting link was sent to participants in advance of the event.

    SHAASAN – Sustainable Hydropower for Africa, Asia and South America Network aims to improve the sustainability of hydropower by protecting the fisheries on which low-income fishing communities in developing nations depend for food security. This will advance environmental impact mitigation technology and develop more sustainable operations and planning practices. We will disseminate outputs and build research capability to benefit other DAC nations, principally the Least Developed and Lower Middle Income Countries in Africa, Asia, and South America.

    SHAASAN – Sustainable Hydropower for Africa, Asia and South America Network is funded through the Global Challenges Research Fund

    Presenters

    Hector Vera- Alcaraz (Paraguay) and Paul Kemp (United Kingdom): Introduction to the SHAASAN Network

    Oscar Link : Chilean context

    Luz Fernanda and Scott Winton : Colombian context

    Paul van Damme : Bolivian context

    Raquel Fontes : Brazilian context

    For further information about the Sustainable Hydropower for Africa, Asia and South America Network SHAASAN please visit:

    http://www.icer.soton.ac.uk/sustainable-hydropower-network/

    Hosted with ICER – International Centre for Ecohydraulics Research, CDT Sustainable Infrastructure Systems http://www.cdt-sis.soton.ac.uk/ and CDT Sustainable Infrastructure for Cities https://cdt-sicities.soton.ac.uk

    Jun 24

     Mitigating the effects of marine renewable energy infrastructure on marine mammals and fish

    The CDT SIS and SIC seminar on Thursday 24 June 2021.

    Presentation by Nick Flores Martin from Natural Resources Wales who has just had his iPhD viva.

    Mitigating the effects of marine renewable energy infrastructure on marine mammals and fish

    About Nick:

    “ I work as a marine mammal specialist advisor with Natural Resources Wales. Successfully defended my viva just over a month ago. My PhD thesis focused on using bubbles and sound as a behavioural deterrent for freshwater fish by trapping sound between bubbles (so a bit like a humpback whale bubble feeding net) – although my background’s more oceanography and fisheries related.”

    Nick Flores Martin NRW Presentation PDF

    Jun 24

    A Virtuous Circle? Increasing Local Benefits from Ports by Adopting Circular Economy Principles

    A Virtuous Circle? Increasing Local Benefits from Ports by Adopting Circular Economy Principles

    by

    Infrastructure Group, Faculty of Engineering and Physical Sciences, University of Southampton,

    Transportation Group, Faculty of Engineering and Physical Sciences, University of Southampton,

    Ramboll UK Ltd., Southampton

    Ramboll UK Ltd., Edinburgh

    Sustainability 202113(13), 7079; https://doi.org/10.3390/su13137079

    Published: 24 June 2021
    As ports seek to maintain support for their operations amidst growing environmental awareness and social pressure, it is important they provide benefits for the local population to offset negative impacts. Ports can add additional economic benefits for the cities they are located in by encouraging maritime clusters, industrial development, a circular economy, and waterfront development. The current level of adoption, interest in future adoption, barriers to implementation, and attitudes towards the views of the local population were assessed via an online questionnaire sent to port authorities in 26 countries. The potential and willingness of ports to be on the frontline of the transition to a circular economy globally has been clearly identified for the first time, seeing a 60% increase between current levels of adoption and future interest in adoption. Barriers to a circular economy are comparable to barriers to widely adopted methods, such as industrial development and a waterfront economy. It is likely that circular economy activities in port cities will add additional local benefits and reduce the negative impacts of a port. A new framework is proposed to help ports and cities collaborate and encourage greater adoption of the circular economy.

    Jun 17

    Artistic impression of a port-city of the future

     

    CDT SIS PhD researcher and amateur artist Toby Roberts won the People’s Choice award at the Doctoral College Festival of Research Awards on 10th June 2021. The Research Awards and Director’s Awards are part of the Festival of Doctoral Research which recognises and celebrates exceptional achievements and contributions of the University’s postgraduate researchers.

    Creative Representations of Research Competition challenged postgraduate researchers to have fun exploring all the different ways in which they can represent and share the essence of their research.

    Port-Cites of the Future

    This painting depicts a port-city of the future, with some potential solutions to reducing the negative impacts of ports whilst increasing the local benefits. Some examples of this in the painting are renewable energy, green architecture, shore-to-ship power and circular economy (in this case a greenhouse to capture waste CO2 and heat for agriculture).

    Toby started painting at the start of his PhD study as a way to relax and he enjoys painting landscapes and seascapes.

    Toby’s research work includes creating a new system of classification for port-cities that includes cargo and passenger ships. “Port-cities have a key role in international trade and provide essential services to the local, regional and national economies. Port-cities can boost manufacturing and growth of port-related industries, contributing jobs to the local area. They can also be popular start- and end-points and destinations for tourist activities, such as cruises. The presence of the port may bring additional opportunities in areas such as employment, renewable energy, circular economy, culture and identity.

    Establishing sustainable cities and communities is one of the 17 United Nations Sustainable Development Goals (SDGs) (SDG number 11). Port-cities are vitally important to efforts to encourage sustainability. It is therefore important to gain a greater understanding and critical evaluation of port-cities, what their requirements and challenges are, how they differ and how they can be better utilised to produce more benefits and fewer negative impacts. As a strong focus is placed on understanding the environmental impacts of ports and sustainability, a system to effectively group port-cities by their size and potential impacts is needed.

    ‘The Southampton System’, combines passenger numbers and cargo tonnage on one axis with urban population on another in a 4 × 4 matrix, creating 16 groupings of port-cities. The Southampton System provides an effective and broader method for port-city classification, enabling more effective future study into, and policy recommendations for, port-cities.”

    Research Article

    The Southampton System: a new universal standard approach for port-city classification

    Toby Roberts Ian Williams  & John Preston 

    Published online for Taylor and Francis: 10 Aug 2020

     

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