Bla i på forfattere "Lie, Bernt"

Adapting dynamic mathematical models to a pilot anaerobic digestion reactor
Haugen, Finn; Bakke, Rune; Lie, Bernt (Journal article; Peer reviewed, 2013)A dynamic model has been adapted to a pilot anaerobic reactor fed diarymanure. Both steadystate data from online sensors and laboratory analysis anddynamic operational data from online sensors are used in the model ... 
Algorithm with improved accuracy for realtime measurement of flow rate in open channel systems
Agu, Cornelius Emeka; Hjulstad, Åsmund; Elseth, Geir; Lie, Bernt (Journal article; Peer reviewed, 2017)Most methods for flow rate measurement in open channels usually have low accuracy over a range of flow rates due to varying fluid properties, flow conditions and channel length. This paper suggests an algorithm to improve ... 
A Sensor Fusion Algorithm for Filtering Pyrometer Measurement Noise in the Czochralski Crystallization Process
Komperød, Magnus; Bones, John Atle; Lie, Bernt (Journal article; Peer reviewed, 2011)The Czochralski (CZ) crystallization process is used to produce monocrystalline silicon for solar cell wafers and electronics. Tight temperature control of the molten silicon is most important for achieving high crystal ... 
A solution method for onedimensional shallow water equations using flux limiter centered scheme for open Venturi channels
Welahettige, Prasanna Kumara Welahetti; Vågsæther, Knut; Lie, Bernt (Journal article; Peer reviewed, 2018)The onedimensional shallow water equations were modified for a Venturi contraction and expansion in a rectangular open channel to achieve more accurate results than with the conventional onedimensional shallow water ... 
Comparison of elastic vs. inelastic penstock model using OpenModelica
Vytvytskyi, Liubomyr; Lie, Bernt (Journal article; Peer reviewed, 2017)The possibility for modelling and simulating hydropower systems as accurately as possible take an important role in order to develop a control structure and to make efficient analysis tools for testing a designed controller ... 
Comparison of Linear Controllers for Nonlinear, Openloop Unstable Reactor
Khalili, Mohammad; Lie, Bernt (Journal article; Peer reviewed, 2018)Many industrially important reactors are operated over a regime where they exhibit nonlinear behavior. Exothermal reactors are often openloop unstable. For such reactors, safe operation with good performance requires good ... 
Comparison of simulation tools for dynamic models
Sund, Sveinung Martinius; Plouvier, Marianne; Lie, Bernt (Journal article; Peer reviewed, 2018)Macroscopic models are used extensively in process engineering, and can often be posed as DAE (Differential Algebraic Equation) models. Three generic tools for solving such DAEs are compared: OpenModelica, Julia, and MATLAB. ... 
Computational fluid dynamics study of flow depth in an open Venturi channel for Newtonian fluid
Welahettige, Prasanna Kuma; Lie, Bernt; Vågsæther, Knut (Journal article; Peer reviewed, 2017)Open Venturi channel flow measurement could be a cheap method to be used in drill bit pressure control. The main objective of this study is to identify the factors related with the flow depth in an open Venturi channel. A ... 
Dynamic Model of an Ammonia Synthesis Reactor Based on Open Information
Jinasena, Asanthi; Lie, Bernt; Glemmestad, Bjørn (Chapter; Peer reviewed, 2016)Ammonia is a widely used chemical, hence the ammonia manufacturing process has become a standard case study in the scientific community. In the field of mathematical modeling of the dynamics of ammonia synthesis reactors, ... 
Empirical Modeling of Heating Element Power for the Czochralski Crystallization Process
Komperød, Magnus; Lie, Bernt (Journal article, 2010)The Czochralski (CZ) crystallization process is used to produce monocrystalline silicon. Monocrystalline silicon is used in solar cell wafers and in computers and electronics. The CZ process is a batch process, where ... 
Flood Control of Lake Toke: Model Development and Model Fitting
Kvam, Kristian D.; Furenes, Beathe; Hasaa, Åsmund; Gjerseth, Alexander Zhang; Skeie, NilsOlav; Lie, Bernt (Journal article; Peer reviewed, 2017) 
Flow regime changes at hydraulic jumps in an open Venturi channel for Newtonian fluid
Welahettige, Prasanna Kuma; Lie, Bernt; Vågsæther, Knut (Journal article; Peer reviewed, 2017) 
Hydropower Systems: Comparison of Mechanistic and Table Lookup Turbine Models
Splavska, Valentyna; Vytvytskyi, Liubomyr; Lie, Bernt (Journal article; Peer reviewed, 2017)In this paper, a detailed overview of hydropower system components is given. Components of the system include intake race, upstream and downstream surge tanks, penstock, turbine and draft tube. A case study which includes ... 
Improved model for solar heating of buildings
Lie, Bernt (Conference object; Peer reviewed, 20151125)A considerable future increase in the global energy use is expected, and the effects of energy conversion on the climate are already observed. Future energy conversion should thus be based on resources that have negligible ... 
Linearization for Analysis of a Hydropower Model using Python API for OpenModelica
Vytvytskyi, Liubomyr; Lie, Bernt (Journal article; Peer reviewed, 2018)Even though almost all processes in the real world are described by nonlinear models, nonlinear theory for analysis of these models is far less developed than the theory for linear models. Therefore model linearization is ... 
Machine Learning in Python for Weather Forecast based on Freely Available Weather Data
Abrahamsen, Erik Boye; Brastein, Ole Magnus; Lie, Bernt (Journal article; Peer reviewed, 2018)Forecasting weather conditions is important for, e.g., operation of hydro power plants and for flood management. Mechanistic models are known to be computationally demanding. Hence, it is of interest to develop models that ... 
Model based control for runofriver system. Part 1: Model implementation and tuning
Vytvytskyi, Liubomyr; Sharma, Roshan; Lie, Bernt (Journal article; Peer reviewed, 2015)Optimal operation and control of a runofriver hydro power plant depends on good knowledge of the elements of the plant in the form of models. River reaches are often considered shallow channels with free surfaces. A ... 
Model based control for runofriver system. Part 2: Comparison of control structures
Vytvytskyi, Liubomyr; Sharma, Roshan; Lie, Bernt (Journal article; Peer reviewed, 2015)Optimal operation and control of a runofriver hydro power plant depend on good knowledge of the elements of the plant in the form of models. Both the control architecture of the system, i.e. the choice of inputs and ... 
Modeling and Simulation of Triclosan Kinetics and Distribution in Humans Using a PBPK Model
Maharjan, Samee; Sharma, Roshan; Husøy, Trine; Dirven, Hubert; Andreassen, Monica; Lie, Bernt (Conference object; Peer reviewed, 20151125)Personal care products (PCPs) such as soaps, perfumes, toothpastes, lotions, etc. contain various chemicals. Triclosan (TCS) is widely used as an antibacterial additive in PCPs. Traces of TCS are found in human plasma and ... 
Modeling and Simulation of Triclosan Kinetics and Distribution in Humans Using PBPK Model
Cascella, Vincenza; Andreassen, Monica; Husøy, Trine; Dirven, Hubert; Lie, Bernt (Journal article; Peer reviewed, 2018)Triclosan (TCS) has been used as an antibacterial additive in several personal care products (PCPs) for more than 40 years. In animals studies, it is observed that TCS in rats has adverse effects on the endocrine function ...