Browsing NTNU Open by Author "Torgersen, Jan"
Now showing items 21-40 of 59
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Extending the limits of Pt/C catalysts with passivation-gas-incorporated atomic layer deposition
Xu, Shicheng; Kim, Yongmin; Park, Joonsuk; Higgins, Drew; Shen, Shih-Jia; Thian, Dickson; Provine, John; Torgersen, Jan; Graf, Tanja; Schladt, Thomas; Orazov, Marat; Liu, Bernard Haochih; Prinz, Fritz (Journal article; Peer reviewed, 2018)Controlling the morphology of noble metal nanoparticles during surface depositions is strongly influenced by precursor–substrate and precursor–deposit interactions. Depositions can be improved through a variety of means, ... -
Fatigue behavior of porous Ti-6Al-4V made by laser-engineered net shaping
Razavi, Seyed Mohammad Javad; Bordonaro, Giancarlo; Ferro, Paolo; Torgersen, Jan; Berto, Filippo (Journal article; Peer reviewed, 2018)The fatigue behavior and fracture mechanisms of additively manufactured Ti-6Al-4V specimens are investigated in this study. Three sets of testing samples were fabricated for the assessment of fatigue life. The first batch ... -
Fatigue strength of blunt V-notched specimens produced by selective laser melting of Ti-6Al-4V
Razavi, Seyed Mohammad Javad; Ferro, P; Berto, Filippo; Torgersen, Jan (Journal article, 2018)Selective Laser Melting (SLM) process is an Additive Manufacturing (AM) technique that allows producing metallic parts of any kind of geometry with densities greater than 99.5%. Complex shapes lead however to notches with ... -
Fracture assessment of magnetostrictive materials
Peron, Mirco; Razavi, Seyed Mohammed Javad; Berto, Filippo; Torgersen, Jan; Colussi, M (Journal article; Peer reviewed, 2017)Giant magnetostrictive materials are gaining interest in the field of smart material, especially the commercially known Terfenol-D, that is an alloy made out of iron, terbium and dysprosium (Tb0.3Dy0.7Fe1.9). Since these ... -
Fracture assessment of PEEK under static loading by means of the local strain energy density
Peron, Mirco; Javad Razavi, Seyed Mohammed; Torgersen, Jan; Berto, Filippo (Journal article; Peer reviewed, 2017)Polyetheretherketone (PEEK) has gained interest in many industrial applications due to its high strength-to-weight ratio, excellent heat tolerance and high corrosion resistance. Stress concentrators such as notches and ... -
Fracture behaviour of notched as-built EBM parts: Characterization and interplay between defects and notch strengthening behaviour
Peron, Mirco; Torgersen, Jan; Ferro, Paolo; Berto, Filippo (Journal article, 2018)Additive manufacturing (AM) offers the potential to economically produce customized components with complex geometries. However, the introduction of complex geometry goes hand in hand with the presence of notches. Thus, ... -
Frontiers of fracture and fatigue: Some recent applications of the local strain energy density
Javad Razavi, Seyed Mohammed; Berto, Filippo; Torgersen, Jan (Journal article; Peer reviewed, 2018)The phenomenon of brittle fracture occurs too often in various branches of engineering being the reason of unexpected termination of anticipated service lives of an engineering objects. This leads to unfortunate catastrophic ... -
High-concentration wide-angle tracking integration with stacked lens arrays
Johnsen, Håkon Jarand Dugstad; Aksnes, Astrid; Torgersen, Jan (Chapter, 2019)Tracking-integration can reduce or eliminate the need for external solar tracking in CPV (concentrator photovoltaics). Previous research has shown how tracking-integrated systems can achieve high concentration ratios, wide ... -
High-performance stationary solar tracking through multi-objective optimization of beam-steering lens arrays
Johnsen, Håkon Jarand Dugstad; Aksnes, Astrid; Torgersen, Jan (Peer reviewed; Journal article, 2020)Beam-steering lens arrays enable solar tracking using millimeter-scale relative translation between a set of lens arrays. This may represent a promising alternative to the mechanical bulk of conventional solar trackers, ... -
Local strain energy density for the fatigue assessment of hot dip galvanized welded joints: Some recent outcomes
Peron, Mirco; Razavi, Seyed Mohammed Javad; Berto, Filippo; Torgersen, Jan; Mutignani, F (Journal article; Peer reviewed, 2017)Since in literature only data about the effect of the hot-dip galvanizing coating on fatigue behavior of unnotched specimens are available, whereas very few for notched components and none for welded joints, the aim of ... -
Local strain energy density for the fracture assessment of polyurethane specimens weakened by notches of different shape
Peron, Mirco; Razavi, Seyed Mohammed Javad; Berto, Filippo; Torgersen, Jan; Marsavina, L (Journal article; Peer reviewed, 2017)Recent studies on local stress fields in proximity of crack and notch tips have shown that Strain Energy Density (SED), averaged in a circular control volume surrounding the point of stress singularities, represents a ... -
Mg and its alloys for biomedical applications: Exploring corrosion and its interplay with mechanical failure
Peron, Mirco; Torgersen, Jan; Berto, Filippo (Journal article; Peer reviewed, 2017)The future of biomaterial design will rely on temporary implant materials that degrade while tissues grow, releasing no toxic species during degradation and no residue after full regeneration of the targeted anatomic site. ... -
Minimizing Ski Friction through Nanostructured Hydrophobic Surfaces
Madsen, Tone Hjort (Master thesis, 2018)The correlation between ski friction and a ski base surface that can enhance hydrophobicity by geometry has been investigated. A review is given of existing knowledge about the linkage between ski friction mechanisms, ... -
Mode II brittle fracture: Recent developments
Campagnolo, A; Razavi, Seyed Mohammed Javad; Peron, Mirco; Torgersen, Jan; Berto, Filippo (Journal article; Peer reviewed, 2017)Fracture behaviour of V-notched specimens is assessed using two energy based criteria namely the averaged strain energy density (SED) and Finite Fracture Mechanics (FFM). Two different formulations of FFM criterion are ... -
Modelling Thermal Effects in a Battery Driven Formula Student Race Car
Beascoechea, Asier (Master thesis, 2019)Denne masteroppgaven er skrevet som en del av enstilling i Revolve NTNU Electric Team 2019 som kjølesystem ansvarlig. Revolve NTNU er en studentorganisasjon som representerer NTNU i verdens største ingeniørkonkurranse, ... -
New approaches to solar tracking and concentration through numerical optimization of lens arrays
Johnsen, Håkon Jarand Dugstad (Doctoral theses at NTNU;2020:405, Doctoral thesis, 2020)Solar concentrators are essential for enabling several solar energy applications, including high-efficiency photovoltaic conversion and high-temperature solar thermal energy. These concentrators require accurate solar ... -
Next Generation Design of Satellite Brackets - By Using Topology Optimization and Additive Manufacturing
Sanden, Øyvind (Master thesis, 2018)This thesis has explored how topology optimization and additive manufacturing can be used to improve the resonance performance of existing mechanical components. By using a sensitivity-based optimization algorithm for ... -
Notch stress intensity factors under mixed mode loadings: An overview of recent advanced methods for rapid calculation
Peron, Mirco; Razavi, Seyed Mohammed Javad; Berto, Filippo; Torgersen, Jan (Journal article; Peer reviewed, 2017)Recently some methods for the rapid calculation of notch stress intensity factors (NSIFs) have been developed and three of them are compared in this work. First, the criteria proposed by Lazzarin et al. and Treifi et al. ... -
Notched graphite under multiaxial loading
Razavi, Seyed Mohammed Javad; Peron, Mirco; Torgersen, Jan; Berto, Filippo (Journal article; Peer reviewed, 2017)Cylindrical specimens made of polycrystalline graphite and weakened by circumferential V-notches under mixed mode I/III loading were studied in this research. Different geometries of V-notches varying the notch opening ... -
Novel Low Cost Solar Thermal Energy Concepts for Developing Countries
Johnsen, Håkon Jarand Dugstad (Master thesis, 2017)Small scale solar thermal energy devices such as solar cookers are promising solutions for remote areas where other energy sources are limited, for instance in developing countries. These devices can be used directly for ...