Blar i USN Open Archive på forfatter "Bjerketvedt, Dag"
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Laminar burning velocity in hydrogen-oxygen-nitrogen mixtures
Thang, Yone Kyin (Master thesis, 2022)As today’s world is demanding a greener environment where greenhouse gas emission and global warming are much reduced, hydrogen has become the most promising element among others from periodic table. As today’s world is ... -
Laminar burning velocity of the dimethyl carbonate–air mixture formed by the Li-ion electrolyte solvent
Henriksen, Mathias; Vågsæther, Knut; Gaathaug, Andre Vagner; Lundberg, Joachim; Forseth, Sissel; Bjerketvedt, Dag (Peer reviewed; Journal article, 2020)If a Li-ion cell fails and the electrolyte leaks out into air, a flammable premixed gas cloud can be formed. The electrolyte combustion energy is 65–70% of the total energy content of the cell. The main objective of this ... -
Makrofotografering med blitz av objekter i mørkefelt
Bjerketvedt, Dag; Andersen, Ragnvald (Journal article; Peer reviewed, 1984) -
Minimum ignition energy of hydrogen and hydrogen-carrying fuels
Jakar, Sarthak (Master thesis, 2022)Hydrogen is touted to be the fuel of the future leading to low carbon emissions globally. But as this fuel is being popularized all over the world for all the industry sectors, very little is known about the combustion ... -
Modeling an image analysis of FAE
Vågsæther, Knut; Christensen, Svein Olav; Bjerketvedt, Dag (Conference lecture, 2008-09) -
Numerical study of premixed gas explosion in a 1-m channel partly filled with 18650 cell-like cylinders with experiments
Henriksen, Mathias; Vågsæther, Knut; Lundberg, Joachim; Forseth, Sissel; Bjerketvedt, Dag (Peer reviewed; Journal article, 2022)Abused and defective Li-ion cells can cause a catastrophic failure of a Li-ion battery (LIB), leading to severe fires and explosions. In recent years, several numerical and experimental studies have been conducted on the ... -
One-dimensional model of turbulent flow of non-Newtonian drilling mud in non-prismatic channels
Welahettige, Prasanna Kumara Welahetti; Lundberg, Joachim; Bjerketvedt, Dag; Lie, Bernt; Vågsæther, Knut (Peer reviewed; Journal article, 2019)One-dimensional model of non-Newtonian turbulent flow in a non-prismatic channel is challenging due to the difficulty of accurately accounting for flow properties in the 1-D model. In this study, we model the 1-D Saint–Venant ... -
Petrifilm TM som alternativt medium for dyrking av bakterier i vann
Rosef, Olav; Odland, Arvid; Bjerketvedt, Dag (Journal article, 2002)Metoden NS-EN ISO 6222 er sammenlignet med Petrifilm for påvisning og telling av mikroorganismer i overflatevann (råvann) og i drikkevann (behandlet vann). De dyrkingstemperaturene som gjeldende drikkevannsforskrift angir ... -
Re-initiation of detonation across an inert region
Bjerketvedt, Dag (Doktor ingeniøravhandling;374, Doctoral thesis, 1985)Re-initiation of gaseous C-J detonation waves across a region of air has been studied experimentally. The experimental apparatus consisted of a 9 meter long square tube with internal dimensions of 125 mm. The Random Choice ... -
Reinsdyrstammen på Hardangervidda for stor
Bjerketvedt, Dag (Journal article, 1981)Hardangervidda, in Southern Norway, is the largest mountain plateau in Europe (Fig. 1). It is approximately 10000 km2 in area and lies mostly between 1100 and 1300 m a.s.l. The topography and vegetational cover produce a ... -
Release of high-pressure hydrogen into the air
Afshar Ghasemi, Keivan (Master thesis, 2021)Hydrogen as an energy carrier is one of the available alternatives to fossil fuels for decarbonizing the global energy system. Regarding to the very low volumetric energy content of gaseous hydrogen, for practical and ... -
Release of liquid CO2 from the bottom of a duct
Mohammed Ibrahim, Osama Kabbashi; Gaathaug, Andre Vagner; Hansen, Per Morten; Bjerketvedt, Dag; Vågsæther, Knut (Peer reviewed; Journal article, 2023)This paper presents experimental results of the rapid phase transition of liquid CO2 released from the bottom of a small rectangular duct (BR). The aim is to consider the factors influencing the phase transitions and the ... -
Simulation of burning velocities in gases vented from thermal run-a-way lithium ion batteries
Johnsplass, Jonathan; Henriksen, Mathias; Vågsæther, Knut; Lundberg, Joachim; Bjerketvedt, Dag (Journal article; Peer reviewed, 2017)This paper describes the results from simulations of laminar burning velocities in the premixed air and flammable gases vented from abused Li-ion batteries. The released mixture from such batteries contain mixtures of ... -
Simulation of FA and DDT in a channel with repeated obstacles with an under-resolved mesh
Vågsæther, Knut; Bjerketvedt, Dag (Conference object; Peer reviewed, 2009) -
Simulation of flame acceleration and DDT in H-2-air mixture with a flux limiter centered method
Vågsæther, Knut; Knudsen, Vegeir; Bjerketvedt, Dag (Journal article; Peer reviewed, 2007)Flame acceleration and deflagration to detonation transition (DDT) is simulated with a numerical code based on a flux limiter centered method for hyperbolic differential equations. The energy source term is calculated by ... -
Simulation of flame acceleration in an obstructed tube with LES
Vågsæther, Knut; Bjerketvedt, Dag (Conference object; Peer reviewed, 2007) -
Structural response analysis of explosions in hydrogen-air mixtures in tunnel-like geometries
Bratland, Magne; Bjerketvedt, Dag; Vågsæther, Knut (Peer reviewed; Journal article, 2021)This paper presents a structural response analysis based on the results of experiments involving gas explosions in inhomogeneous hydrogen-air mixtures in a channel. The channel was 3 m long, with a cross-section of 100 mm ... -
Superoxide dismutase polymorphisms in wild populations of herb Paris (Paris quadrifolia L., Trilliaceae)
Jogaitė, Vaida; Kleizaitė, Violeta; Stapulionyte, Asta; Bjerketvedt, Dag (Journal article, 2003)Polymorphism of superoxide dismutase (SOD) was investigated in leaves of herb Paris (Paris quadrifolia L., Trilliaceae). The plants were collected during the summer and autumn of 2001 from different natural locations in ... -
The effect of water spray and mist on the hydrogen-air explosion
Thapa, Suraj (Master thesis, 2022)With the world shifting to greener energy, hydrogen has received more traction than any other alternative fuel in the last decade. With it comes the risk of hydrogen-air explosion. The effects of water mist in explosion ... -
The growth and phenology patterns of herb Paris (Paris quadrifolia L., Trilliaceae): relation to soil and air temperatures
Bjerketvedt, Dag; Odland, Arvid; Lazutka, Juozas R.; Naujalis, Jonas (Journal article; Peer reviewed, 2003)The phenology and development of Paris quadrifolia L. has been related to variations in soil and air temperatures during four seasons (1997-2000). Its emergence appeared to be strongly dependant on soil temperature. Plants ...