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Otosaka, I.N. (author), Shepherd, Andrew (author), Ivins, Erik R. (author), Schlegel, Nicole-Jeanne (author), Amory, Charles (author), Simon, K.M. (author), Schrama, Ernst (author), van der Wal, W. (author), Wouters, B. (author)Ice losses from the Greenland and Antarctic ice sheets have accelerated since the 1990s, accounting for a significant increase in the global mean sea level. Here, we present a new 29-year record of ice sheet mass balance from 1992 to 2020 from the Ice Sheet Mass Balance Inter-comparison Exercise (IMBIE). We compare and combine 50 independent...journal article 2023
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Schrama, Ernst (author), Visser, P.N.A.M. (author)In this paper we review the precision orbit determination (POD) performance of the CryoSat-2 mission where we used all tracking data between June-2010 and Jan-2023; with station and beacon coordinates provided in the ITRF2020 reference system, we use a mean gravity model, and we use spacecraft specific models for modeling drag and radiation...journal article 2023
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- Dettmering, D. (author), Schrama, Ernst (author) contribution to periodical 2023
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Scheinert, Mirko (author), Engels, Olga (author), Schrama, Ernst (author), van der Wal, W. (author), Horwath, Martin (author)Geodynamic processes in Antarctica such as glacial isostatic adjustment (GIA) and post-seismic deformation are measured by geo-detic observations such as global navigation satellite systems (GNSS) and satellite gravimetry. GNSS measurements have comprised both continuous measurements and episodic measurements since the mid-1990s. The...journal article 2023
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Naeije, M.C. (author), Schrama, Ernst (author), Di Bella, Alessandro (author), Bouffard, Jerome (author)ESA’s Earth Explorer CryoSat-2 precisely measures the changes in the thickness of marine ice floating on the polar oceans and variations in the thickness of the vast ice sheets that overlie Greenland and Antarctica. The data delivered by the CryoSat-2 mission completes the picture to determine and understand the ice role in the Earth system in...poster 2022
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Nederstigt, Tom A.P. (author), Peijnenburg, Willie J.G.M. (author), Schrama, Maarten (author), van Ommen, J.R. (author), Vijver, Martina G. (author)Recently, the delivery of pesticides through novel controlled-release (nano-)formulations has been proposed intending to reduce (incidental) pesticide translocation to non-target sites. Concerns have however been raised with regards to the potentially enhanced toxicity of controlled-release (nano-)formulations to non-target organisms and...journal article 2022
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Schrama, F.N.H. (author)In this PhD thesis, the desulphurisation in 21st century iron- and steelmaking is investigated. The current state of the art in sulphur removal in ironmaking and oxygen steelmaking is discussed (Part I of this thesis) and optimisation of the hot metal desulphurisation (HMD) slag, which is an important aspect of present day desulphurisation, is...doctoral thesis 2021
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Schrama, F.N.H. (author), Beunder, Elisabeth M. (author), Emami, Ali (author), Barnes, Chris M. (author), van Boggelen, Johan W.K. (author), Sietsma, J. (author), Boom, R. (author), Yang, Y. (author)The HIsarna process is one of the emerging low-CO<sub>2</sub> ironmaking processes that could help the steel industry in achieving their carbon footprint goals. HIsarna hot metal contains 3–4 times more sulfur than hot metal from blast furnaces (BFs). Therefore, a literature study, a thermodynamic analysis, and plant data analysis from Tata...journal article 2021
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Schrama, F.N.H. (author), Beunder, Elisabeth M. (author), Panda, Sourav K. (author), Visser, Hessel Jan (author), Moosavi-Khoonsari, Elmira (author), Sietsma, J. (author), Boom, R. (author), Yang, Y. (author)In hot metal desulphurisation (HMD) the slag will hold the removed sulphur. However, the iron that is lost when the slag is skimmed off, accounts for the highest costs of the HMD process. These iron losses are lower when the slag has a lower viscosity, which can be achieved by changing the slag composition. A lower slag basicity decreases the...journal article 2021
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Schrama, F.N.H. (author), Beunder, Elisabeth M. (author), Panda, Sourav K. (author), Visser, Hessel Jan (author), Moosavi-Khoonsari, Elmira (author), Hunt, Adam (author), Sietsma, J. (author), Boom, R. (author), Yang, Y. (author)The optimal hot metal desulphurisation (HMD) slag is defined as a slag with a sufficient sulphur removal capacity and a low apparent viscosity (η<sub>slag</sub>) which leads to low iron losses. In part I of this study, the fundamentals behind the optimal slag were discussed. In this part these fundamentals are explored by a Monte Carlo...journal article 2021
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Schrama, F.N.H. (author), Ji, Fuzhong (author), Hunt, Adam (author), Beunder, Elisabeth M. (author), Woolf, Rhian (author), Tuling, Alison (author), Warren, Peter (author), Sietsma, J. (author), Boom, R. (author), Yang, Y. (author)To lower the iron losses of the hot metal desulphurisation (HMD) process, slag modifiers can be added to the slag. Slag modifiers decrease the apparent viscosity of the HMD slag. Most common slag modifiers in industry contain fluoride as a fluidiser. However, fluoride leads to a higher magnesium consumption and has health, safety and...journal article 2020
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Lopez Jimenez, Sergi (author), Pastor-Rodríguez, Alejandro (author), Setty, Srinivas J. (author), Escobar Anton, Diego (author), Schrama, Ernst (author), Agueda Mate, Alberto (author)Regular products within the field of Space Surveillance and Tracking (SST) and Space Traffic Management (STM), such as high-risk collisions, upcoming re-entries or fragmentations, rely both on the estimated state and associated uncertainty of detectable resident space objects (RSOs). Classical orbit determination (OD) algorithms provide the...abstract 2019
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Schrama, F.N.H. (author), Beunder, Elisabeth M. (author), Visser, H. (author), Boom, R. (author), Sietsma, J. (author), Yang, Y. (author)During the magnesium-lime co-injection process for hot metal desulphurisation, graphite can precipitate as a result of carbon oversaturation. The formed graphite is known to form a layer between the slag and the hot metal. This potentially blocks the sulphides, that are formed during the desulphurisation process, to reach the slag phase thus...conference paper 2019
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Schrama, F.N.H. (author), Beunder, Elisabeth M. (author), Visser, H. (author), Sietsma, J. (author), Boom, R. (author), Yang, Y. (author)Carbon may precipitate during the hot metal desulfurization (HMD) process as a result of carbon oversaturation because of temperature decrease. The precipitated carbon flakes form a layer between hot metal and slag. It is postulated that this carbon layer hampers desulfurization with magnesium by preventing MgS particles from reaching the...journal article 2019
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Groh, Andreas (author), Horwath, Martin (author), Horvath, Alexander (author), Meister, Rakia (author), Wouters, B. (author), Ditmar, P.G. (author), Ran, J. (author), Klees, R. (author), Schrama, Ernst (author)Satellite gravimetry data acquired by the Gravity Recovery and Climate Experiment (GRACE) allows to derive the temporal evolution in ice mass for both the Antarctic Ice Sheet (AIS) and the Greenland Ice Sheet (GIS). Various algorithms have been used in a wide range of studies to generate Gravimetric Mass Balance (GMB) products. Results from...journal article 2019
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Cazenave, Anny (author), Riva, R.E.M. (author), Schrama, Ernst (author)Global mean sea level is an integral of changes occurring in the climate system in response to unforced climate variability as well as natural and anthropogenic forcing factors. Its temporal evolution allows changes (e.g., acceleration) to be detected in one or more components. Study of the sea-level budget provides constraints on missing or...journal article 2018
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Schrama, F.N.H. (author), Beunder, Elisabeth M. (author), Ji, Fuzhong (author), Woolf, Rhian (author), Barnes, Chris (author), Sietsma, J. (author), Boom, R. (author), Yang, Y. (author)At the hot metal desulphurisation (HMD) stations of Tata Steel’s BOS plant in Port Talbot (UK), KAlF4 is injected together with magnesium in order to increase the fluidity of the slag and thus to decrease the iron loss. Although KAlF4 is successfully contributing to a lower iron loss during HMD, it also has a negative effect on the...conference paper 2018
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Schrama, F.N.H. (author), Beunder, Elisabeth M. (author), van Boggelen, J.W.K. (author), Boom, R. (author), Yang, Y. (author)HIsarna is a smelting reduction ironmaking process that is currently in the pilot plant development phase. HIsarna produces hot metal with higher sulphur, lower phosphorus and manganese, almost no silicon and titanium and a lower temperature compared to the blast furnace. Because of that, desulphurisation of the HIsarna hot metal is one of the...conference paper 2017
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Schrama, F.N.H. (author), Beunder, E.M. (author), van den Berg, B (author), Yang, Y. (author), Boom, R. (author)Sulphur removal in the ironmaking and oxygen steelmaking process is reviewed. A sulphur balance is made for the steelmaking process of Tata Steel IJmuiden, the Netherlands. There are four stages where sulphur can be removed: in the blast furnace (BF), during hot metal (HM) pretreatment, in the converter and during the secondary metallurgy (SM...journal article 2017
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Xu, Z. (author), Schrama, Ernst (author), van der Wal, W. (author), van den Broeke, MR (author), Enderlin, EM (author)In this study, we use satellite gravimetry data from the Gravity Recovery and Climate Experiment (GRACE) to estimate regional mass change of the Greenland ice sheet (GrIS) and neighboring glaciated regions using a least squares inversion approach. We also consider results from the input–output method (IOM). The IOM quantifies the difference...journal article 2016