Browsing Institutt for energi og prosessteknikk by Title
Now showing items 2685-2704 of 4198
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New techniques for measuring thermal properties and surface heat transfer applied to food freezing
(Doktoravhandlinger ved NTNU, 1503-8181; 2007:6, Doctoral thesis, 2007)This thesis presents two different works. The first part introduces a thermal multimeter which measures heat capacity, thermal conductivity and density. The instrument gives continuous measurement data within a temperature ... -
New technologies for purification and carbon capture in hydrogen production from natural gas
(Master thesis, 2015)In a society increasingly concerned with environmentally friendly solutions for energy extraction, hydrogen is expected to be an important energy carrier. Hydrogen can originate from various feedstocks, where fossil fuels ... -
New type of energy exchanger for ventilation air
(Master thesis, 2016)Energieffektive varmevekslere er viktige for å minimalisere energien som kreves for oppvarming og ventilasjon. I bygninger med sentralisert luftbehandlingsaggregat er det viktig å unngå lekkasjer mellom avkast og tilluft. ... -
A new version of the Hermite-Hadamard inequality for Riemann-Liouville fractional integrals
(Peer reviewed; Journal article, 2020)Integral inequalities play a critical role in both theoretical and applied mathematics fields. It is clear that inequalities aim to develop different mathematical methods. Thus, the present days need to seek accurate ... -
New zeotropic CO<inf>2</inf>-based refrigerant mixtures for cascade high-temperature heat pump to reach heat sink temperature up to 180 °C
(Peer reviewed; Journal article, 2023)There is a great demand for clean, high-temperature heating in industries. The present work demonstrates the modeling and analysis of a high-temperature heat pump (HTHP) using a two-stage cascade refrigeration system with ... -
Next generation of ejector-supported R744 booster systems for commercial refrigeration at all climates
(Peer reviewed; Journal article, 2023)The pernicious effects of synthetic refrigerants on different environmental aspects leave natural refrigerants as the only alternative for vapour compressions systems. Among natural refrigerants, CO2 (R744) has become the ... -
The NExus Solutions Tool (NEST) v1.0: An open platform for optimizing multi-scale energy-water-land system transformations
(Peer reviewed; Journal article, 2020)The energy–water–land nexus represents a critical leverage future policies must draw upon to reduce trade-offs between sustainable development objectives. Yet, existing long-term planning tools do not provide the scope or ... -
Ni/NiO nanosheets for alkaline hydrogen evolution reaction: In situ electrochemical-Raman study
(Journal article; Peer reviewed, 2020)Nickel/Nickel oxide (Ni/NiO) nanosheets heterostructure is a cheap and active catalyst for hydrogen evolution reaction (HER) in alkaline electrolytes. However, the reason for this activity is still under debate. Herein ... -
NiCu mixed metal oxide catalyst for alkaline hydrogen evolution in anion exchange membrane water electrolysis
(Peer reviewed; Journal article, 2021)We report on the optimization of nickel-copper catalysts for superior performance as a cathode catalyst in anion exchange membrane (AEM) water electrolysis. The bifunctional system of NiCu mixed metal oxide (MMO) nanosheets ... -
No-mix vanadium redoks flytbatteri
(Bachelor thesis, 2022)Hensikten med denne oppgaven er å eksperimentelt verifisere litteraturen som peker på at no-mix vanadium redoks flytbatterier (VRFB), utnytter elektrolytten bedre enn, og har høyere virkningsgrad enn, mer konvensjonelle ... -
No-Slip Boundary Conditions for the Lattice Boltzmann Method and High Order Accurate Interface Representation for Volume Tracking
(Doktoravhandlinger ved NTNU, 1503-8181; 2011:268, Doctoral thesis, 2011)The present thesis focuses on two distinct topics of computational fluid dynamics. The first one, treated in part I, focuses on the no-slip boundary conditions for the lattice Boltzmann method, whereas the second one, ... -
A Non-Compact Effective Impedance Model for Can-To-Can Acoustic Communication: Analysis and Optimization of Damping Mechanisms
(Peer reviewed; Journal article, 2021)Can-annular combustors can feature azimuthal instabilities even if the acoustic coupling between the individual cans is weak. Recently, various studies have focused on modeling the acoustic communication between adjacent ... -
Non-Intrusive Data Monitoring and Analysis of Occupant Energy-Use Behaviors in Shared Office Spaces
(Peer reviewed; Journal article, 2020)A non-intrusive data collection framework is developed to analyze the desk-level occupancy and energy use patterns of occupants in shared office spaces. The framework addresses the limitations of previous studies in the ... -
Non-Newtonian Analysis of a Counter-flow Mixing Reactor for Fast Hydrothermal Liquefaction
(Chapter, 2020)A CFD (computational fluid dynamics) model has been developed in ANSYNS Fluent for studying the use of the nozzle reactor concept for fast HTL of biomass. A Newtonian system was first assumed to make it possible to utilize ... -
Non-perturbative theory of dispersion interactions
(Journal article; Peer reviewed, 2015)Some open questions exist with fluctuation-induced forces between extended dipoles. Conventional intuition derives from large-separation perturbative approximations to dispersion force theory. Here, we present a full ... -
Nonlinear interaction between clustered unstable thermoacoustic modes in can-annular combustors
(Peer reviewed; Journal article, 2020)A can-annular combustor consists of a set of nominally identical cans, in which the flames burn in an essentially isolated manner. However, adjacent cans are able to communicate acoustically, which provides dynamic coupling ... -
The Nonlinear Thermoacoustic Eigenvalue Problem and Its Rational Approximations: Assessment of Solution Strategies
(Peer reviewed; Journal article, 2022)Nonlinear eigenvalue problems (NLEVPs) arise in thermoacoustics by considering the temporal evolution of small perturbations in the relevant governing equations. In this work, two solution strategies are compared: (i) a ... -
Nonperturbative theory for the dispersion self-energy of atoms
(Journal article; Peer reviewed, 2014)We go beyond the approximate series expansions used in the dispersion theory of finite-size atoms. We demonstrate that a correct, and nonperturbative, theory dramatically alters the dispersion self-energies of atoms. The ... -
Nonsmooth Analysis In Process Modeling, Design And Optimization
(Chapter, 2019)Nonsmooth models provide a powerful, compact and intuitive modeling paradigm that can represent a growing spectrum of physical phenomena over broad ranges of conditions in terms of the original process variables. This paper ... -
Nonsmooth Formulation for Handling Unclassified Process Streams in the Optimization of Work and Heat Exchange Networks
(Peer reviewed; Journal article, 2019)Pinch analysis provides a systematic methodology for improving efficiency through enhanced process integration. Originally, the methodology focused on heat integration with heat exchanger network (HEN) synthesis. However, ...