Blar i NTNU Open på forfatter "Nepstad, Raymond"
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A comparison of Eulerian and Lagrangian methods for vertical particle transport in the water column
Nordam, Tor; Kristiansen, Ruben; Nepstad, Raymond; van Sebille, Erik; Booth, Andy (Journal article, 2023)A common task in oceanography is to model the vertical movement of particles such as microplastics, nanoparticles, mineral particles, gas bubbles, oil droplets, fish eggs, plankton, or algae. In some cases, the distribution ... -
Effects of Exposure Timing on cyp1a Expression, PAH Elimination, and Lipid Utilization in Lumpfish Embryos Exposed to Produced Water
Hansen, Bjørn Henrik; Arukwe, Augustine Ebeku; Knutsen, Hannah Marie; Skarpnord, Kaja Skyrud; Farkas, Julia; Veylit, Lara; Nepstad, Raymond; Khan, Essa Ahsan; Nordtug, Trond; Sørensen, Lisbet (Peer reviewed; Journal article, 2023)Intentional discharges of produced water from oil production platforms to the marine environment contain a complex mixture of toxicants, including polycyclic aromatic hydrocarbons (PAHs). Early life stages of fish are ... -
Guidelines and best available techniques for submarine tailings disposal in Norwegian fjords: Recommendations from the NYKOS project
Ramirez-Llodra, Eva; Andersen, Guri Sogn; Bekkby, Trine; Brooks, Steven; Escudero-Oñate, Carlos; Gundersen, Hege; Schaanning, Morten; Trannum, Hilde Cecilie; Yakushev, Evgeniy; Baeten, Nicole; Lepland, Aivo; Ibragimova, Olga; Kleiv, Rolf Arne; Nepstad, Raymond; Muñoz, María; Høgaas, Helge; Sandøy, Roar (NIVA-rapport;, Research report, 2019)The NYKOS project aimed at addressing some of the main knowledge gaps on the environmental impacts of submarine tailing disposal (STD) to facilitate the development of techniques, practices and management measures that ... -
High-resolution numerical modelling of a marine mine tailings discharge in Western Norway
Nepstad, Raymond; Muñoz, Maria Liste; Alver, Morten; Nordam, Tor; Davies, Emlyn John; Glette, Tormod (Peer reviewed; Journal article, 2020)Waste from mining operations includes mine tailings, a slurry of fine-grained mineral particles and processing chemicals that remains after the desired compounds have been extracted from the ore. In some cases, the method ... -
An impact-based environmental risk assessment model toolbox for offshore produced water discharges
Nepstad, Raymond; Kotzakoulakis, Konstantinos; Hansen, Bjørn Henrik; Nordam, Tor; Carroll, JoLynn (Peer reviewed; Journal article, 2023)We present a novel approach to environmental risk assessment of produced water discharges based on explicit impact and probability, using a combination of transport, fate and toxicokinetic-toxicodynamic models within a ... -
Implementing and reviewing a published cellular automaton model for simulating erosion and deposition processes due to turbidity currents
Gundersen, Steinar Brattøy (Master thesis, 2019)Gruveindustrien har i lengre tid benyttet seg av sjødeponi for lagring av "tailings". I slike sjødeponi er det vanlig at turbiditetsstrømmer oppstår som følge av utslippet, hvilket medfører at partiklene fraktes en lengre ... -
New insights into submarine tailing disposal for a reduced environmental footprint: Lessons learnt from Norwegian fjords
Ramirez-Llodra, Eva; Trannum, Hilde Cecilie; Andersen, Guri Sogn; Baeten, Nicole; Brooks, Steven; Escudero-Oñate, Carlos; Gundersen, Hege; Kleiv, Rolf Arne; Ibragimova, Olga; Lepland, Aivo; Nepstad, Raymond; Sandøy, Roar; Schaanning, Morten; Shimmield, Tracy; Yakushev, Evgeniy; Ferrando-Climent, Laura; Høgaas, Per Helge (Peer reviewed; Journal article, 2022)Submarine tailing disposal (STD) in fjords from land-based mines is common practice in Norway and takes place in other regions worldwide. We synthesize the results of a multidisciplinary programme on environmental impacts ... -
Numerical analysis of boundary conditions in a Lagrangian particle model for vertical mixing, transport and surfacing of buoyant particles in the water column
Nordam, Tor; Kristiansen, Ruben; Nepstad, Raymond; Röhrs, Johannes (Journal article; Peer reviewed, 2019)Lagrangian particle models are used for many applications in the ocean sciences, including transport modelling of oil spills, fish eggs and larvae, plastics, and sediment particles. In the context of oil spill modelling, ... -
Numerical Integration and Interpolation in Marine Pollutant Transport Modelling
Nordam, Tor; Brönner, Ute; Skancke, Jørgen; Nepstad, Raymond; Rønningen, Petter; Alver, Morten (Chapter, 2018) -
On the use of random walk schemes in oil spill modelling
Nordam, Tor; Nepstad, Raymond; Litzler, Emma; Röhrs, Johannes (Journal article; Peer reviewed, 2019)In oil spill models, vertical mixing due to turbulence is commonly modelled by random walk. If the eddy diffusivity varies with depth, failing to take the derivative of the diffusivity into account in the random walk scheme ... -
SubSea Dispersant lnjection (SSDI)- a "state of the art" and the need for further documentations
Daling, Per Snorre; Brakstad, Odd Gunnar; Brandvik, Per Johan; Davies, Emlyn J.; Grøsvik, Bjørn Einar; Meier, Sonnich; Nepstad, Raymond; Nordtug, Trond; Vikebø, Frode Bendiksen (;2017:00007 A, Research report, 2017)The aim of this pre-project has been to give a "State-of the art" and describe the R&D challenges and documentation needed in order to perform robust NEBA (Net Environmental Benefit Analysis) where SubSea Dispersant Injection ...