A supplement to a bibliography of samplers for benthic invertebrates

A supplement to the earlier bibliography compiled by Elliott and Tullett 1978 (FBA Occas. Publ. No. 4) covering literature from December 1977 - December 1982 on samplers that could be used for the rapid removal of benthic intertebrates from the natural substrata of rivers and streams. In addition it includes papers on marine samplers that have been or could be used in freshwater

Advanced Bionic Attachment Equipment Inspired by the Attachment Performance of Aquatic Organisms: A Review

In nature, aquatic organisms have evolved various attachment systems, and their attachment ability has become a specific and mysterious survival skill for them. Therefore, it is significant to study and use their unique attachment surfaces and outstanding attachment characteristics for reference and develop new attachment equipment with excellent performance. Based on this, in this review, the unique non-smooth surface morphologies of their suction cups are classified and the key roles of these special surface morphologies in the attachment process are introduced in detail. The recent research on the attachment capacity of aquatic suction cups and other related attachment studies are described. Emphatically, the research progress of advanced bionic attachment equipment and technology in recent years, including attachment robots, flexible grasping manipulators, suction cup accessories, micro-suction cup patches, etc., is summarized. Finally, the existing problems and challenges in the field of biomimetic attachment are analyzed, and the focus and direction of biomimetic attachment research in the future are pointed out

Rehabilitation of structures below the earths surface using fibre reinforced polymer shell augers and fabrication of plastic compounder

Many ageing highway bridges are in distress, requiring urgent repairs or rehabilitation. About 10% of the total highway bridges require rehabilitation in United States of America (Houlihan, April 2015). Reconstruction of these bridges requires large sums of money and time consuming conventional rehab schemes. Herein, a novel rehab scheme with Fiber Reinforced Polymer (FRP) composites has been evaluated in the laboratory as FRPs exhibit high strength to weight ratio, high stiffness and excellent corrosion resistance. Current methods to repair pile systems are limited by access issues as the piles are extended typically underwater and below the mudline. Traditional methods require cofferdams or other barrier systems to work in the dry or divers to work in the wet. Access is also hindered as the piles support the existing bridge; i.e. there is a structure overhead and repairs have to be made around the existing pile supporting super structure. Proper repairs typically require digging below the mudline, which complicates any traditional repair method. The repair method proposed herein seeks to solve both the access and excavation issues by combining an augering attachment to FRP formwork that can be installed around an existing pile. Twisting the FRP formwork engages the auger, which drives the forms below the mudline. This method can be adopted above water, eliminating the need for barrier systems or divers. The auger attachment can be modified based on soil conditions. As the shell bores down, additional shells can be attached to the previously attached shell by an overlapping joint and also reinforcing the shell with FRP composite wrap to prevent potential buckling under torsion and to minimize moisture ingress through the shell. Based on the compactness of the soil and/or hardness, FRP composites can be selected with proper fiber volume fraction and orientation. In this study, field conditions have been replicated in lab and three different kinds of Auger attachments to the FRP composite shell are tested with manual application of torque to understand various challenges in driving these shells below the mudline. The stresses developed in the shell, both by the application of torque and resistance offered by soil are measured using of strain gages. The strain gage readings are evaluated with respect to strain limits of FRP composite to understand the FRP-soil interaction and to attain safe shell design. Plastic waste is the other major issue at present. The production is increasing every year rapidly but the recycling is not. The plastic waste that is not recycled is dumped in oceans or landfilled causing disturbance in ecological cycle. To reduce ecological disturbance, a compounding machine converting the plastic waste into a structurally useful product has been discussed herein as a second part of this report

The Design of Pumpjets for Hydrodynamic Propulsion

A procedure for use in the design of a wake adapted pumpjet mounted on the aft end of a body of revolution is presented. To this end, a pumpjet is designed for the Akron airship. The propulsor mass flow is selected to minimize kinetic energy losses through the duct and in the discharge jet. The shaft speed and disk size are selected to satisfy specified limits of cavitation performance and to provide acceptable blade loading. The streamtubes which pass through a propulsor mounted on a tapered afterbody follow essentially conical surfaces. A method is provided for defining these surfaces as a function of shroud geometry, rotor head distribution, and the energy distribution of the ingested mass flow. The three-dimensional effects to which the conical flow subjects the cylindrical blade design sections are described and a technique is presented which permits incorporation of these effects in the blade design procedure

Measurement of underwater noise arising from marine aggregate dredging operations

This is the final report for project MALSF MEPF 09/P108, funded by the Aggregate Levy Sustainability Fund, the aim of which is to provide data for the typical underwater radiated noise levels from marine aggregate dredgers in the UK fleet during normal operations. The work is aligned with the stated aims of the ALSFMEPF to reduce the environmental footprint of marine extraction of aggregates, and follows directly from the key knowledge gap identified in the initial scoping study conducted in MEPF Project 08/P21 [Thomsen et al, 2009]. The key finding of the study is the noise output of dredging vessels is similar to a ‘noisy merchant vessel’ and is substantially quieter in terms of acoustic energy output than some other anthropogenic noise sources such as seismic airguns and marine pile driving. This project has been an extensive study of the noise generated by the UK’s fleet of trailing suction hopper dredgers during marine aggregate extraction. The objectives of the work were (i) to develop a suitable methodology for measuring underwater noise radiated by dredgers, (ii) undertake measurements on UK dredgers at up to four sites and report, whilst disseminating the results to the wider stakeholder community. In the report, data is presented for 6 vessels, measured across 3 different areas around the UK’s coast

Coastal Geohazard and Offshore Geotechnics

With rapid developments being made in the exploration of marine resources, coastal geohazard and offshore geotechnics have attracted a great deal of attention from coastal geotechnical engineers, with significant progress being made in recent years. Due to the complicated nature of marine environmnets, there are numerous natural marine geohazard preset throughout the world’s marine areas, e.g., the South China Sea. In addition, damage to offshore infrastructure (e.g., monopiles, bridge piers, etc.) and their supporting installations (pipelines, power transmission cables, etc.) has occurred in the last decades. A better understanding of the fundamental mechanisms and soil behavior of the seabed in marine environments will help engineers in the design and planning processes of coastal geotechnical engineering projects. The purpose of this book is to present the recent advances made in the field of coastal geohazards and offshore geotechnics. The book will provide researchers with information reagrding the recent developments in the field, and possible future developments. The book is composed of eighteen papers, covering three main themes: (1) the mechanisms of fluid–seabed interactions and the instability associated with seabeds when they are under dynamic loading (papers 1–5); (2) evaluation of the stability of marine infrastructure, including pipelines (papers 6–8), piled foundation and bridge piers (papers 9–12), submarine tunnels (paper 13), and other supported foundations (paper 14); and (3) coastal geohazards, including submarine landslides and slope stability (papers 15–16) and other geohazard issues (papers 17–18). The editors hope that this book will functoin as a guide for researchers, scientists, and scholars, as well as practitioners of coastal and offshore engineering

Maintenance Concept Study for Deep Subsea Tunnels: Rogfast Tunnel as a Case

Today, Norway has 1259 road tunnels, 1185 are categorized as inland tunnels and 41 are categorized as subsea tunnels. In fact, the number of subsea tunnels has doubled in the last 20 years and entering a more challenging era as deeper and longer underwater tunnels are either already built, in progress, or planned. Keeping such complex assets available at minimal operations and maintenance cost requires effective maintenance engineering analysis to be considered during the early design and project phase. Therefore, the purpose of this thesis is to explore the state of the practice of maintenance engineering for deep underwater tunnels, specifically in Norway. To explore that, a case study method has been applied where the Rogfast tunnel is purposefully selected and analysed. Rogfast will be the deepest and longest underwater tunnel in the whole world and it is currently in the middle of the project phase. The case study has focused on the five main aspects of maintenance engineering: technical hierarchy, consequence classification, failure mode analysis, maintenance data exchange, and reliability and availability analysis. The case study has utilized data from existing tunnels, e.g., Ryfylke tunnel, Mastrafjord tunnel and Karmoy tunnel, to extract failure modes, failure rate, mean time to repair. The findings indicate a lack in the current practice of maintenance engineering at the project phase, due to the domination of safety over other consequences like availability, operating cost, and environmental impact. Considering availability, operating cost, and environmental issues provide a more realistic image of the potential operating expenditures. It will also enable the need to collect specific data categories according to standardized technical hierarchy and data exchange framework and initiate analysis regarding potential failure modes, system reliability and availability, prioritizing maintenance concepts and tasks. Therefore, this thesis proposes and demonstrates a more customised technical hierarchy and consequence classification matrix to enable maintenance engineering analysis and maintenance data exchange. It is found that the Rogfast tunnel has a unique configuration due to the roundabout at Kvitsoy that might be utilized to gain a higher level of tunnel availability. It is also demonstrated how new trends and maintenance programs like condition-based, predictive and perspective maintenance can be explored. The methodology applied in this thesis complies with NORSOK Z-008 and is well known for oil and gas sector. However, it is customised in this thesis to fit the tunnel industry