Anja Røyne

• Dziadkowiec, Joanna & Røyne, Anja (2025). Ion-Dependent Calcium Carbonate Cohesion: Insights from Surface Forces Measured between Calcite Surfaces. Reviews in Mineralogy and Geochemistry, Mineralogical Society of America. ISSN 1529-6466. 91A(1), s. 251–293. doi: 10.2138/rmg.2025.91A.08. Fulltekst i vitenarkiv
• Mirmotahari, Omid; Gasparini, Andrea Alessandro; Velden, Maja Van Der; Røyne, Anja & Komissarova, Tatsiana (2025). Miljøparadokset i kunstig intelligens: En balansegang mellom teknologisk fremskritt og bærekraft. Nordic Journal of STEM Education. 9(2), s. 250–254. doi: 10.5324/njsteme.v9i2.6403. Fulltekst i vitenarkiv Vis sammendrag

  I takt med at kunstig intelligens (KI) og andre avanserte teknologier revolusjonerer vårt samfunn, vokser bekymringen for deres miljøpåvirkning. Dette posisjonsdokumentet undersøker det paradoksale forholdet mellom teknologisk utvikling og miljømessig bærekraft, med særlig fokus på ressursbruk og energiforbruk. Vi drøfter hvordan utviklingen av stadig mer kraftfulle systemer står i konflikt med bærekraftsmål, og utforsker potensielle løsninger for å balansere teknologisk fremskritt med miljøansvar. Særlig vektlegger vi betydningen av å integrere bærekraftsperspektiver og digital kompetanse i STEM-utdanning for å forberede fremtidens forskere, designere, ingeniører og beslutningstakere på tvers av naturvitenskap, teknologi, ingeniørfag og matematikk.

• Razbani, Mohammad Amin; Røyne, Anja & Jettestuen, Espen (2024). A One-Dimensional Reactive Transport Model for Microbially Induced Calcium Carbonate Precipitation (MICP) in Phreeqc. Geomicrobiology Journal. ISSN 0149-0451. s. 1–11. doi: 10.1080/01490451.2024.2425295. Fulltekst i vitenarkiv Vis sammendrag

  Microbially induced calcium carbonate precipitation (MICP) is a geotechnical solution with a low ecological footprint. Conducting MICP inside a porous medium can be used for biocementation. Despite many models and tools being published for simulating MICP, a computationally light, easy-to-use, and freely-available simulation tool is lacking. In this work, we present a reactive transport model using the native capabilities of the Phreeqc software (a free and open-source geochemical solver). We model MICP inside a column packed with sands and inoculated with bacteria. Our model is a one-dimensional representation of the column that accounts for the kinetics of precipitation and ureolysis as well as porosity change. We verify our model by simulating previously published MICP experiments to show our model gives reasonably well predictions. Sensitivity analysis of our model’s input parameters and discussions around their range are presented. Additionally, we calculate the supersaturation of calcite as a function of space and time—a feature that could be important for precipitation, but it is commonly ignored in MCIP modeling. Our scripts developed for running simulations are accessible publicly. Due to the low computational effort required for the simulations, our Phreeqc scripts can be used to design and test different treatment recipes for conducting MICP.

• Perilla, Ana Lucia Campana; Gomez-Bolivar, Jamie; Merroun, Mohamed; Joudeh, Nadeem; Saragliadis, Athanasios & Røyne, Anja [Vis alle 8 forfattere av denne artikkelen] (2024). Characterization of Bimetallic Pd-Fe Nanoparticles Synthesized in Escherichia coli. ACS Applied Bio Materials (AABM). 7(12), s. 8573–8589. doi: 10.1021/acsabm.4c01354. Fulltekst i vitenarkiv Vis sammendrag

  Biologically mediated nanoparticle (NP) synthesis offers a reliable and sustainable alternative route for metal NP production. Compared with conventional chemical and physical production methods that require hazardous materials and considerable energy expenditure, some microorganisms can reduce metal ions into NPs during standard metabolic processes. However, to be considered a feasible commercial option, the properties and inherent activity of bio-NPs still need to be significantly improved. In this work, we present an Escherichia coli-mediated synthesis method for catalytically active Pd–Fe NPs. The produced biogenic Pd–Fe NPs with varying Fe content were characterized using complementary analytical techniques to assess their size, composition, and structural properties. In addition, their catalytic performance was assessed by using standardized chemical reactions. We demonstrate that the combination of Pd with Fe leads to synergistic effects that enhance the catalytic performance of Pd NPs and make biogenic Pd–Fe NPs excellent potential substitutes for currently used catalysts. Briefly, the apparent rates for the model reaction of 4-nitrophenol reduction to 4-aminophenol catalyzed by Pd-based nanoparticles were as high as 0.1312 min–1 using bimetallic Pd–Fe NPs, which is far superior to the rates of monometallic Pd NPs counterparts. This study provides a feasible strategy for the synthesis of multimetallic Pd-based NPs using common microbial processes. It emphasizes the potential of biogenic Pd–Fe NPs as efficient and sustainable catalysts for hydrogenation reactions, offering an environmentally friendly synthesis for various applications, including wastewater treatment and the production of fine chemicals.

• Heier, Nicholas; Chakravarti, Anika; Røyne, Anja & Parrish, Kristen (2023). Exploring How Lean Project Delivery Supports Carbon Capture, Utilization, and Storage for Industrial Retrofits. Annual Conference of the International Group for Lean Construction. ISSN 2309-0979. s. 531–539. doi: 10.24928/2023/0238. Fulltekst i vitenarkiv Vis sammendrag

  The “lean construction ideal” is to maximize stakeholder value, minimize waste, and emphasize collaboration throughout the design, construction, and operating stages of a building project. In practice, lean construction relies on methods such as the Integrated Project Delivery (IPD) system to align stakeholder interests and share risks throughout the project lifecycle. IPD effectively enfranchises various project stakeholders as parties to one agreement, integrating their involvement throughout the design and construction process. While lean construction methods are evidenced to enhance project efficiency in cost and schedule while improving quality, the collaboration fostered by IPD also creates a project environment conducive to innovation and the adoption of new technologies. To that end, lean construction environments, and IPD projects in particular, may offer an opportunity to increase the adoption rates of more environmentally-conscious design alternatives, particularly as the construction industry continues to trend in a more sustainable direction. This paper explores how the lean project delivery system supports incorporating innovative design options on retrofit construction projects (i.e., on existing facilities), and leverages incorporating carbon capture, utilization, and storage (CCUS) systems on cement plants as a proof of concept.

• Razbani, Mohammad Amin; Jettestuen, Espen & Røyne, Anja (2023). Direct Pore-Scale Numerical Simulation of Microbially Induced Calcium Carbonate Precipitation. Water Resources Research. ISSN 0043-1397. 59(1), s. 1–14. doi: 10.1029/2022WR032988. Fulltekst i vitenarkiv Vis sammendrag

  Microbially induced calcium carbonate precipitation (MICP) is a promising method for eco-friendly solutions in geotechincal engineering. MICP involves highly coupled processes in geochemistry and bacterial metabolism that take place in a porous medium. Advancement of these processes drives calcite crystal growth which leads to a decrease in porosity and permeability of the medium. Mathematical models are being developed and used to predict the fate of system at different conditions. Micro-scale and local bio-geochemical evolution and its role on the overall macroscopic fate of MICP needs further investigation. In this work, a pore-scale reactive transport model of MICP for biocementation is developed in a closed system. MICP is simulated in a sample porous geometry in 2D using a native geochemical solver and a lattice Boltzmann solver that handles diffusive transport. We present reactive-transport factors to up-scale pore-scale effects and quantify the efficiency of MICP at different stages of the process. Our results show that pore-scale effects on the average concentration of urea and calcium are not significant after the initial 20% of urea have been consumed. On the other hand, the pH evolution in the system is significantly affected by pore-scale effects. We also explored effects of biomass density and biomass distribution on the reactive transport factors, as well as the effect of the urea to calcium ratio on the resulting crystallization patterns. We found that a higher ratio of rate of ureolysis to rate of precipitation leads to more nucleation sites and more uniform calcite precipitation in the geometry.

• Li, Lei; Kohler, Felix; Dziadkowiec, Joanna; Røyne, Anja; Marzal, Rosa M. Espinosa & Bresme, Fernando [Vis alle 8 forfattere av denne artikkelen] (2022). Limits to Crystallization Pressure. Langmuir. ISSN 0743-7463. 38(37), s. 11265–11273. doi: 10.1021/acs.langmuir.2c01325. Fulltekst i vitenarkiv Vis sammendrag

  Crystallization pressure drives deformation and damage in monuments, buildings, and the Earth’s crust. Even though the phenomenon has been known for 170 years, there is no agreement between theoretical calculations of the maximum attainable pressure and experimentally measured pressures. We have therefore developed a novel experimental technique to image the nanoconfined crystallization process while controlling the pressure and applied it to calcite. The results show that displacement by crystallization pressure is arrested at pressures well below the thermodynamic limit. We use existing molecular dynamics simulations and atomic force microscopy data to construct a robust model of the disjoining pressure in this system and thereby calculate the absolute distance between the surfaces. On the basis of the high-resolution experiments and modeling, we formulate a novel mechanism for the transition between damage and adhesion by crystallization that may find application in Earth and materials sciences and in conservation of cultural heritage.

• Dziadkowiec, Joanna; Ban, Matea; Javadi, Shaghayegh; Jamtveit, Bjørn & Røyne, Anja (2021). Ca2+ ions decrease adhesion between two (104) calcite surfaces as probed by Atomic Force Microscopy. ACS Earth and Space Chemistry. 5(10), s. 2827–2838. doi: 10.1021/acsearthspacechem.1c00220. Fulltekst i vitenarkiv Vis sammendrag

  Solution composition-sensitive disjoining pressure acting between the mineral surfaces in fluid-filled granular rocks and materials controls their cohesion, facilitates the transport of dissolved species, and may sustain volume-expanding reactions leading to fracturing or pore sealing. Although calcite is one of the most abundant minerals in the Earth’s crust, there is still no complete understanding of how the most common inorganic ions affect the disjoining pressure (and thus the attractive or repulsive forces) operating between calcite surfaces. In this atomic force microscopy study, we measured adhesion acting between two cleaved (104) calcite surfaces in solutions containing low and high concentrations of Ca2+ ions. We detected only low adhesion between calcite surfaces, which was weakly modulated by the varying Ca2+ concentration. Our results show that the more hydrated calcium ions decrease the adhesion between calcite surfaces with respect to monovalent Na+ at a given ionic strength, and thus Ca2+ can sustain relatively thick water films between contacting calcite grains even at high overburden pressures. These findings suggest a possible loss of cohesion and continued progress of reaction-induced fracturing for weakly charged minerals in the presence of strongly hydrated ionic species.

• Zehner, Jennifer Simone; Røyne, Anja & Sikorski, Pawel (2021). Calcite seed-assisted microbial induced carbonate precipitation (MICP). PLOS ONE. 16(2). doi: 10.1371/journal.pone.0240763. Fulltekst i vitenarkiv Vis sammendrag

  Microbial-induced calcium carbonate precipitation (MICP) is a biological process inducing biomineralization of CaCO3. This can be used to form a solid, concrete-like material. To be able to use MICP successfully to produce solid materials, it is important to understand the formation process of the material in detail. It is well known that crystallization surfaces can influence the precipitation process. Therefore, we present in this contribution a systematic study investigating the influence of calcite seeds on the MICP process. We focus on the changes in the pH and changes of the optical density (OD) signal measured with absorption spectroscopy to analyze the precipitation process. Furthermore, optical microscopy was used to visualize the precipitation processes in the sample and connect them to changes in the pH and OD. We show, that there is a significant difference in the pH evolution between samples with and without calcite seeds present and that the shape of the pH evolution and the changes in OD can give detailed information about the mineral precipitation and transformations. In the presented experiments we show, that amorphous calcium carbonate (ACC) can also precipitate in the presence of initial calcite seeds and this can have implications for consolidated MICP materials.

• Zehner, Jennifer Simone; Røyne, Anja & Sikorski, Pawel (2021). A sample cell for the study of enzyme-induced carbonate precipitation at the grain-scale and its implications for biocementation. Scientific Reports. 11. doi: 10.1038/s41598-021-92235-7. Fulltekst i vitenarkiv Vis sammendrag

  Biocementation is commonly based on microbial-induced carbonate precipitation (MICP) or enzyme-induced carbonate precipitation (EICP), where biomineralization of CaCO3 in a granular medium is used to produce a sustainable, consolidated porous material. The successful implementation of biocementation in large-scale applications requires detailed knowledge about the micro-scale processes of CaCO3 precipitation and grain consolidation. For this purpose, we present a microscopy sample cell that enables real time and in situ observations of the precipitation of CaCO3 in the presence of sand grains and calcite seeds. In this study, the sample cell is used in combination with confocal laser scanning microscopy (CLSM) which allows the monitoring in situ of local pH during the reaction. The sample cell can be disassembled at the end of the experiment, so that the precipitated crystals can be characterized with Raman microspectroscopy and scanning electron microscopy (SEM) without disturbing the sample. The combination of the real time and in situ monitoring of the precipitation process with the possibility to characterize the precipitated crystals without further sample processing, offers a powerful tool for knowledge-based improvements of biocementation.

• Claxton, James Benedict; Joudeh, Nadeem; Røyne, Anja; Linke, Dirk & Mikheenko, Pavlo (2020). Sequential magnetic mapping of bacteria loaded with Pd-Fe nanoparticles, 2020 IEEE 10th International Conference on “Nanomaterials: Applications & Properties” (NAP – 2020). IEEE (Institute of Electrical and Electronics Engineers). ISSN 9781728185064. s. 01NIC01-1–01NIC01-5. doi: 10.1109/NAP51477.2020.9309619. Fulltekst i vitenarkiv Vis sammendrag

  Magnetic nanoparticles are of widespread use in nanotechnology. One of the most unusual are magnetic palladium nanoparticles that combine magnetism with high catalytic activity. These nanoparticles could be obtained biologically by exposing bacteria to a palladium salt. Due to their small size and weak magnetism, however, it is challenging to measure their magnetic properties. One of the solutions to enhance their magnetism is to incorporate a small amount of iron atoms into them. After this procedure, the nanoparticles together with bacteria can be embedded in resin and characterized by the technique of magnetic force microscopy. This technique allows imaging cross-sections of the bacteria with nanoparticles, but cannot give information from the depth of the sample. Here we report on an approach partially solving this problem. Its novelty lies in measurements of consecutive thin slices of resin, which allows mapping cross-sections of individual bacteria and different parts of the material surrounding the same bacterium. An interesting observed feature is the formation of magnetic chains of nanoparticles outside of the bacteria.

• Perilla, Ana Lucia Campaña; Joudeh, Nadeem; Høyer, Henrik; Røyne, Anja; Linke, Dirk & Mikheenko, Pavlo (2020). Probing van der Waals and magnetic forces in bacteria with magnetic nanoparticles, 2020 IEEE 10th International Conference on “Nanomaterials: Applications & Properties” (NAP – 2020). IEEE (Institute of Electrical and Electronics Engineers). ISSN 9781728185064. s. 01NSSA03-1–01NSSA03-5. doi: 10.1109/NAP51477.2020.9309722. Fulltekst i vitenarkiv Vis sammendrag

  Bioinspired metal-based nanoparticles have potential uses in many applications, but before a possible commercial exploitation, it is important to clarify the pathways of their production and deposition inside the organisms, for example in bacteria. The technique of magnetic force microscopy (MFM) could be used to evaluate the nanoparticles magnetic properties, in addition to allowing tracing their location inside or outside of bacteria, which could help to understand pathways of their biosynthesis. In this work, using MFM and analyzing the interaction of magnetic tip with nanoparticles and bacteria imbedded in resin at different heights above the surface, and comparing gradients of forces recorded by magnetic and non-magnetic tips, a condition was found, which allows to measure pure magnetic response of Pd-Fe nanoparticles. For these nanoparticles, the interplay between magnetic and van der Waals forces is described at small distances to the surface. Experimental data are compared with simulations, based on the calculation of the distribution of magnetic field around a nanoparticle, which defines magnetic force acting on the MFM tip.

• Zehner, Jennifer Simone; Røyne, Anja; Wentzel, Alexander & Sikorski, Pawel (2020). Microbial-induced calcium carbonate precipitation: an experimental toolbox for in situ and real time investigation of micro-scale pH evolution. RSC Advances. 10(35), s. 20485–20493. doi: 10.1039/d0ra03897k. Fulltekst i vitenarkiv Vis sammendrag

  Concrete is the second most consumed product by humans, after water. However, the production of conventional concrete causes more than 5% of anthropogenic CO2 emissions and therefore there is a need for emission-reduced construction materials. One method to produce a solid, concrete-like construction material is microbial-induced calcium carbonate precipitation (MICP). To get a better understanding of MICP it is important to be able to follow local pH changes in dissolution and precipitation processes of CaCO3. In this work we present a new method to study processes of MICP at the micro-scale in situ and in real time. We present two different methods to monitor the pH changes during the precipitation process of CaCO3. In the first method, the average pH of small sample volumes is measured in real time, and pH changes are subsequently correlated with processes in the sample by comparing to optical microscope results. The second method is introduced to follow local pH changes at a grain scale in situ and in real time. Furthermore, local pH changes during the dissolution of CaCO3 crystals are monitored. We demonstrate that these two methods are powerful tools to investigate the pH changes for both MICP precipitation and CaCO3 dissolution for knowledge-based improvement of MICP-based material properties.

• Høgberget, Jørgen; Røyne, Anja; Dysthe, Dag Kristian & Jettestuen, Espen (2020). Microscopic modeling of contact formation between confined surfaces in solution. arXiv.org. ISSN 2331-8422. Fulltekst i vitenarkiv Vis sammendrag

  We derive a Kinetic Monte Carlo model for studying how contacts form between confined surfaces in an ideal solution. The model incorporates repulsive and attractive surface-surface forces between a periodic (2+1)-dimensional solid-on-solid (SOS) crystal surface and a confining flat surface. The repulsive interaction is derived from the theory of electric double-layers, and the attractive interactions are Van der Waals interactions between particles on the SOS surface and the confining surface. The confinement is induced by a constant external pressure normal to the surfaces which is in mechanical equilibrium with the surface-surface forces. The system is in thermal equilibrium, and particles can deposit to and dissolve from the SOS surface. The size of stable contacts formed between the surfaces in chemical equilibrium show a non-trivial dependency on the external pressure which is phenomenologically similar to the dependency of oscillatory hydration forces on the surface-surface separation. As contacts form we find classical phenomena such as Ostwald ripening, coalescence, and primary and secondary nucleation stages. We find contacts shaped as islands, bands or pits, depending solely on the contact size relative to the system size. We also find the model to behave well out of chemical equilibrium. The model is relevant for understanding processes where the force of crystallization and pressure solution are key mechanisms.

• Dziadkowiec, Joanna & Røyne, Anja (2020). Nanoscale Forces between Basal Mica Surfaces in Dicarboxylic Acid Solutions: Implications for Clay Aggregation in the Presence of Soluble Organic Acids. Langmuir. ISSN 0743-7463. 36(49), s. 14978–14990. doi: 10.1021/acs.langmuir.0c02290. Fulltekst i vitenarkiv Vis sammendrag

  The stability of organomineral aggregates in soils has a key influence on nutrient cycling, erosion, and soil productivity. Both clay minerals with distinct basal and edge surfaces and organic molecules with reactive functional groups offer rich bonding environments. While clay edges often promote strong inner-sphere bonding of −COOH-laden organics, we explore typically weaker, outer-sphere bonding of such molecules onto basal planes and its significance in organomineral interactions. In this surface force apparatus study, we probed face-specific interactions of negatively charged mica basal surfaces in solutions containing carboxyl-bearing, low-molecular-weight dicarboxylic acids (DAs). Our experiments provide distance-resolved, nanometer-range measurements of forces acting between two (001) mica surfaces and simultaneously probe DA adsorption. We show that background inorganic ions display crucial importance in nanoscale forces acting between basal mica surfaces and in DA adsorption: Na+ contributes to strong repulsion and little binding of dicarboxylic anions, while small amounts of Ca2+ are sufficient to screen the basal surface charge of mica, facilitate strong adhesion, and enhance dicarboxylic anion adsorption by acting as cationic bridges. Despite reversible and weak adsorption of DAs, we resolve their multilayer binding via assembly of hydrophobic chains in the presence of Ca2+, pointing the importance of abundant, less reactive basal clay surfaces in organomineral interactions.

• Myhr, Anders; Røyne, Frida; Brandtsegg, Andreas Saur; Bjerkseter, Catho; Throne-Holst, Harald & Borch, Anita [Vis alle 8 forfattere av denne artikkelen] (2019). Towards a low CO2 emission building material employing bacterial metabolism (2/2): Prospects for global warming potential reduction in the concrete industry. PLOS ONE. 14(4). doi: 10.1371/journal.pone.0208643. Fulltekst i vitenarkiv Vis sammendrag

  The production of concrete is one of the most significant contributors to global greenhouse gas emissions. This work focuses on bio-cementation-based products and their potential to reduce global warming potential (GWP). In particular, we address a proposed bio-cementation method employing bacterial metabolism in a two-step process of limestone dissolution and recrystallisation (BioZEment). A scenario-based techno-economic analysis (TEA) is combined with a life cycle assessment (LCA), a market model and a literature review of consumers’ willingness to pay, to compute the expected reduction of global GWP. Based on the LCA, the GWP of 1 ton of BioZEment is found to be 70–83% lower than conventional concrete. In the TEA, three scenarios are investigated: brick, precast and onsite production. The results indicate that brick production may be the easiest way to implement the products, but that due to high cost, the impact on global GWP will be marginal. For precast production the expected 10% higher material cost of BioZEment only produces a marginal increase in total cost. Thus, precast production has the potential to reduce global GWP from concrete production by 0–20%. Significant technological hurdles remain before BioZEment-based products can be used in onsite construction scenarios, but in this scenario, the potential GWP reduction ranges from 1 to 26%. While the potential to reduce global GWP is substantial, significant efforts need to be made both in regard to public acceptance and production methods for this potential to be unlocked.

• Røyne, Anja; Phua, Yi Jing; Le, Simone Balzer; Eikjeland, Ina Grosås; Josefsen, Kjell Domaas & Markussen, Sidsel [Vis alle 10 forfattere av denne artikkelen] (2019). Towards a low CO2 emission building material employing bacterial metabolism (1/2): The bacterial system and prototype production. PLOS ONE. 14(4). doi: 10.1371/journal.pone.0212990. Fulltekst i vitenarkiv Vis sammendrag

  The production of concrete for construction purposes is a major source of anthropogenic CO2 emissions. One promising avenue towards a more sustainable construction industry is to make use of naturally occurring mineral-microbe interactions, such as microbial-induced carbonate precipitation (MICP), to produce solid materials. In this paper, we present a new process where calcium carbonate in the form of powdered limestone is transformed to a binder material (termed BioZEment) through microbial dissolution and recrystallization. For the dissolution step, a suitable bacterial strain, closely related to Bacillus pumilus, was isolated from soil near a limestone quarry. We show that this strain produces organic acids from glucose, inducing the dissolution of calcium carbonate in an aqueous slurry of powdered limestone. In the second step, the dissolved limestone solution is used as the calcium source for MICP in sand packed syringe moulds. The amounts of acid produced and calcium carbonate dissolved are shown to depend on the amount of available oxygen as well as the degree of mixing. Precipitation is induced through the pH increase caused by the hydrolysis of urea, mediated by the enzyme urease, which is produced in situ by the bacterium Sporosarcina pasteurii DSM33. The degree of successful consolidation of sand by BioZEment was found to depend on both the amount of urea and the amount of glucose available in the dissolution reaction.

• Dziadkowiec, Joanna; Zareeipolgardani, Bahareh; Dysthe, Dag Kristian & Røyne, Anja (2019). Nucleation in confinement generates long-range repulsion between rough calcite surfaces. Scientific Reports. 9. doi: 10.1038/s41598-019-45163-6. Fulltekst i vitenarkiv Vis sammendrag

  Fluid-induced alteration of rocks and mineral-based materials often starts at confined mineral interfaces where nm-thick water films can persist even at high overburden pressures and at low vapor pressures. These films enable transport of reactants and affect forces acting between mineral surfaces. However, the feedback between the surface forces and reactivity of confined solids is not fully understood. We used the surface forces apparatus (SFA) to follow surface reactivity in confinement and measure nm-range forces between two rough calcite surfaces in NaCl, CaCl2, or MgCl2 solutions with ionic strength of 0.01, 0.1 or 1 M. We observed long-range repulsion that could not be explained by changes in calcite surface roughness, surface damage, or by electrostatic or hydration repulsion, but was correlated with precipitation events which started at µm-thick separations. We observed a submicron-sized precipitate that formed in the confined solution. This liquid-like viscous precipitate did not undergo any spontaneous ripening into larger crystals, which suggested that confinement prevented its dehydration. Nucleation was significantly postponed in the presence of Mg2+. The long-range repulsion generated by nucleation between confined mineral surfaces can have a crucial influence on evolution of the microstructure and therefore the macroscopic strength of rocks and materials.

• Li, Lei; Sanchez, Jesus Rodriguez; Kohler, Felix; Røyne, Anja & Dysthe, Dag Kristian (2018). Microfluidic control of nucleation and growth of CaCO3. Crystal Growth & Design. ISSN 1528-7483. 18(8), s. 4528–4535. doi: 10.1021/acs.cgd.8b00508. Fulltekst i vitenarkiv Vis sammendrag

  A novel method for studying nucleation and growth of CaCO3 crystals in situ has been developed and tested rigorously. We demonstrate that precise flow control is essential and how this is achieved. The method has the advantage that one may study single crystals of polymorphs that are thermodynamically unstable in collections of many crystals and that one obtains precise and accurate growth rates without any extra assumptions. We also demonstrate that, at low supersaturations where 2D nucleation does not occur, we measure the growth rate constant of calcite to be 5 times larger than that reported by batch methods and 2 orders of magnitude larger than that measured by atomic force microscopy. Considering the large interest in calcite growth in, for example, geoscience, environmental science, and industry, it is important to explain the discrepancy of growth rate constants between different methods. The method presented here can easily be applied to many other minerals.

• Javadi, Shaghayegh & Røyne, Anja (2018). Adhesive forces between two cleaved calcite surfaces in NaCl solutions: The importance of ionic strength and normal loading. Journal of Colloid and Interface Science. ISSN 0021-9797. 532, s. 605–613. doi: 10.1016/j.jcis.2018.08.027. Fulltekst i vitenarkiv Vis sammendrag

  The mechanical strength of calcite bearing rocks is influenced by pore fluid chemistry due to the variation in nano-scale surface forces acting at the grain contacts or close to the fracture tips. The adhesion of two contacting surfaces, which affects the macroscopic strength of the material, is not only influenced by the fluid chemistry but also by the surface topography. In this paper, we use Atomic Force Microscope (AFM) to measure the interfacial forces between two freshly cleaved calcite surfaces in CaCO3-saturated solutions with varying NaCl concentration. We show that calcite contacts become stronger with increasing NaCl concentration (> 100 mM), as a result of progressively weaker secondary hydration and increasing attraction due to instantaneous ion-ion correlation. Moreover, we discuss the effect of normal applied force (Fn) and surface roughness on the measured adhesion forces (Fad). We show that the measured pull-off force (adhesion) is linearly correlated with the magnitude of Fn, where an increase in applied force results in increased adhesion. This is attributed to a larger number of contacting surface asperities and thus increase in real contact area and the contact-bond strength. We discuss that the possible variation in local topography at contacts, together with strong dependence on ionic strength of the solution, can explain the inconsistent behavior of calcite rocks in NaCl solutions.

Se alle arbeider i NVA

• Røyne, Anja (2025). Livet, døden, krig og korn. Historier om nitrogen. Humanist Forlag. ISBN 9788282823012. 316 s. doi: https:/www.humanistforlag.no/boker/livet-doden-krig-og-korn/. Fulltekst i vitenarkiv
• Røyne, Anja (2023). Klimaendringer - enkelt forklart. Universitetsforlaget. ISBN 9788215061504. Fulltekst i vitenarkiv
• Røyne, Anja (2020). Varm klode, kaldt hode. Løsninger på klimakrisen. Kagge Forlag AS. ISBN 9788248926344. 231 s. Fulltekst i vitenarkiv
• Røyne, Anja (2020). Fysikk - enkelt forklart. Universitetsforlaget. ISBN 9788215034454. 159 s. Fulltekst i vitenarkiv

Se alle arbeider i NVA

• Jemterud, Torkild; Delsett, Lene Liebe; Røyne, Anja & Hrubos-Strøm, Harald (2025). Hvorfor får du dårlig ånde av å sove? - Abels tårn - NRK Radio. [Radio]. NRKP2. Fulltekst i vitenarkiv Vis sammendrag

  Sammen med et ekspertpanel gir tårndiktator Torkild Jemterud svar på alt du ikke visste du lurte på. Send oss dine spørsmål i appen NRKradio. Søk opp Abels tårn og trykk på snakkebobla

• Skogvoll, Vidar; Garvang, Even Sletteng; Wahl, Andreas Solberg; Dahlen, Pia Ve; Andersen, Gard Lilledal & Røyne, Anja (2025). Under Kappa #55 - Fantastiske 4: Mysteriet i Oslo. doi: https:/www.youtube.com/watch?app=desktop&v=phUVkoJXPJM. Fulltekst i vitenarkiv
• Røyne, Anja; Simon, Nina; Nyheim, Martine & Haynes, Helene Victoria (2025). Tverrfaglig kompetanse og bærekraftskompetanse: hvordan fremme integrasjon i prosjektarbeid? Fulltekst i vitenarkiv
• Røyne, Anja & Simon, Nina (2025). Including consumer behavior in assessing the systems wide environmental impacts of business decisions in sustainability transitions. Fulltekst i vitenarkiv
• Dziadkowiec, Joanna; Liberto, Teresa; Bellotto, Maurizio; Robisson, Agathe; Røyne, Anja & Valtiner, Markus (2024). Measurements of surface forces between reactive mineral surfaces. Fulltekst i vitenarkiv
• Skogvoll, Vidar; Garmann-Aarhus, Benedicte; Røyne, Anja & Bråthen, Ole Markus (2023). Real læring - ChatGPT: Fagformidling med robothjelp. [Radio]. Podcast. Fulltekst i vitenarkiv
• Jemterud, Torkild; Skogvoll, Vidar; Røyne, Anja; Eriksen, Anita; Gravensteen, Ida Kathrine & Ellingsen-Dalskau, Kristian (2023). Abels tårn - Abels Påskemix - Hvorfor liker vi surt godteri, sånn rent evolusjonært? [Radio]. P2. Fulltekst i vitenarkiv
• Røyne, Anja (2023). Gruvedrift på havbunnen må vente. Fulltekst i vitenarkiv
• Engebretsen, Solveig; Bøckman, Petter; Røyne, Anja & Jemterud, Torkild (2023). Abels tårn - Hvorfor faller ikke skyene ned. [Radio]. NRK P2. Fulltekst i vitenarkiv
• Jemterud, Torkild; Skogvoll, Vidar; Eriksen, Anita & Røyne, Anja (2023). Abels tårn - Abels påsketårn - Myrlik og mørkets dragning. [Radio]. P2. Fulltekst i vitenarkiv
• Skogvoll, Vidar; Jemterud, Torkild; Bøckman, Petter & Røyne, Anja (2022). Abels tårn - Det iler i skrittet når jeg ser smerte! Fulltekst i vitenarkiv
• Dziadkowiec, Joanna; Javadi, Shaghayegh; Ban, Matea; Jamtveit, Bjørn & Røyne, Anja (2022). Ion-dependent adhesion between calcite surfaces. Fulltekst i vitenarkiv
• Perilla, Ana Lucia Campana; Joudeh, Nadeem; Merroun, Mohamed; Gomez-Bolivar, Jamie; Røyne, Anja & Linke, Dirk [Vis alle 7 forfattere av denne artikkelen] (2022). Biosynthesis and characterization of Palladium-Based Nanoparticles using Escherichia coli. Fulltekst i vitenarkiv
• Dziadkowiec, Joanna; Zareeipolgardani, Bahareh; Cheng, Hsiu-Wei; Dysthe, Dag Kristian; Røyne, Anja & Valtiner, Markus (2021). Forces between reactive surfaces. Fulltekst i vitenarkiv Vis sammendrag

  Adhesive and repulsive, nm-range surface forces acting between mineral grains control colloidal stability and mineral aggregation but less is known about how these forces are affected by surface reactivity and to what extent these grain-scale forces can influence various deformation processes in rocks. In this experimental work, we explore and quantify the surface forces acting between dynamic mineral surfaces that undergo recrystallization or are chemically reactive in contact with water or aqueous salt solutions. Our experimental setup consists of the surface forces apparatus (SFA) coupled with the multiple beam interferometry (MBI). This setup can excellently reproduce a typical grain contact geometry with nanometer-thin water films confined between contacting mineral grains over relatively large, micron-sized contact areas. Owing to the use of MBI, both surface growth or dissolution processes can be monitored during force measurements in real-time. As such, SFA can provide information about the links between surface reactivity and adhesive or repulsive surface forces. Using the examples of force measurements between recrystallizing or chemically reactive mineral surfaces such as carbonates, hydroxides, and silicates, we comment on the relationship between the measured surface forces and surface reactivity. We link our findings with the observed changes in mineral phases, surface topographies, or surface roughness. We also comment on how the micron-scale confinement in the SFA affects the growth and dissolution processes in contrast to less confined regions. The magnitude of the forces associated with dynamic mineral surfaces and the potential significance of these forces to macroscopic deformation processes and cohesion in rocks are discussed.

• Røyne, Anja (2021). Klimafiksing. Fulltekst i vitenarkiv
• Røyne, Anja (2021). Bokprat: Varm klode, kaldt hode. Fulltekst i vitenarkiv
• Røyne, Anja (2021). Varm klode, kaldt hode. [Internet]. Podcastopptak for Viken fylkesbibliotek. Fulltekst i vitenarkiv
• Røyne, Anja (2021). Digitalt frokostmøte: klimakrisen trenger ledere som Hamlet. [Internet]. Nationaltheatret. Fulltekst i vitenarkiv
• Røyne, Anja & Eriksen, Thomas Hylland (2021). Varm klode, kaldt hode. [Internet]. Stavanger sakprosafestival. Fulltekst i vitenarkiv
• Dziadkowiec, Joanna; Ban, Matea; Javadi, Shaghayegh; Jamtveit, Bjørn & Røyne, Anja (2021). Ion-specific adhesion between brittle calcite surfaces. Fulltekst i vitenarkiv
• Dziadkowiec, Joanna & Røyne, Anja (2021). Do soluble organic acids bind to basal mica surfaces? Fulltekst i vitenarkiv Vis sammendrag

  Soluble organic acids are constantly supplied to soils as a result of the oxidative decomposition of organic matter by the plant roots and microorganisms. These carboxylic group-bearing organic molecules can interact with soil clay minerals and affect the formation and stability of organomineral aggregates. While it has been suggested that –COOH laden organics can strongly bind to broken clay edges, less is known about how such soluble acids interact with negatively charged basal clay surfaces. This work presents a Surface Forces Apparatus (SFA) study of interactions between two mica surfaces in dicarboxylic acid molecules with 2 to 7 carbon atoms. SFA allows measuring nanoscale surface forces acting between macroscopic surfaces as a function of surface separation. Since, unlike as in atomic force microscopy, the absolute surface separation in the SFA is known, it is possible simultaneously probe the adsorption of dicarboxylic acids onto mica. The results show that significant amounts of dicarboxylic acids can adsorb on mica surfaces, but only in the presence of Ca2+ ions. Ca2+ acts as cationic bridges between the negatively charged mica surface and deprotonated –COO- functionalities. In addition, the multilayer binding of larger dicarboxylic acids (C5-C7) via an assembly of hydrophobic chains is resolved. Na+ does not promote any substantial dicarboxylic acid adsorption and induce strong repulsion between mica surfaces. In summary, although these face-specific SFA measurements show that dicarboxylic acids adsorb onto mica basal surfaces only by weak forces including electrostatic, hydrophobic, and likely hydrogen bonding, they demonstrate that even such weak outer-sphere adsorption can affect adhesion between clay surfaces and play a role in the organomineral aggregate formation. Acknowledgments: This study has been financed by the Research Council of Norway (grant No 286733) and the European Union Horizon 2020 (grant No 642976-Nano-Heal).

• Einevoll, Gaute & Røyne, Anja (2020). Om løsninger på klimakrisen. [Internet]. Podcast: Vett og vitenskap med Gaute Einevoll. Fulltekst i vitenarkiv
• Einevoll, Gaute; Samset, Bjørn Hallvard; Sverdrup-Thygeson, Anne; Svihus, Birger; Østby, Hilde & Røyne, Anja [Vis alle 7 forfattere av denne artikkelen] (2020). Om å gi alle jordas mennesker gode liv uten å ødelegge miljøet. [Internet]. Podcast: Vett og vitenskap med Gaute Einevoll. Fulltekst i vitenarkiv
• Røyne, Anja & Seehusen, Joachim (2020). Lager betong med bakterier – gir store reduksjoner i CO₂-utslipp. [Journal]. Teknisk Ukeblad. Fulltekst i vitenarkiv
• Dziadkowiec, Joanna; Zareeipolgardani, Bahareh; Dysthe, Dag Kristian & Røyne, Anja (2020). Confined Nucleation of Calcium Carbonate Studied in the Surface Forces Apparatus. Fulltekst i vitenarkiv
• Dziadkowiec, Joanna; Cheng, Hsiu-Wei; Røyne, Anja & Valtiner, Markus (2020). Interfacial processes at dissimilarly charged mineral surfaces in contact – a surface forces apparatus study. Fulltekst i vitenarkiv
• Dziadkowiec, Joanna; Cheng, Hsiu-Wei; Røyne, Anja & Valtiner, Markus (2020). Interactions between reactive mineral surfaces studied with the surface forces apparatus. Fulltekst i vitenarkiv
• Røyne, Anja (2020). Menneskets grunnstoffer. Fulltekst i vitenarkiv
• Røyne, Anja (2020). Ekko: Abels Tårn. [Radio]. NRK P2. Fulltekst i vitenarkiv
• Røyne, Anja (2020). Menneskets grunnstoffer. Fulltekst i vitenarkiv
• Røyne, Anja (2020). Ekko. Løsninger på klimakrisen. [Radio]. NRK P2. Fulltekst i vitenarkiv
• Røyne, Anja (2020). Menneskets grunnstoffer. Fulltekst i vitenarkiv
• Røyne, Anja (2020). Menneskets grunnstoffer. Fulltekst i vitenarkiv
• Røyne, Anja (2020). Ekko: Abels tårn. [Radio]. NRK P2. Fulltekst i vitenarkiv
• Røyne, Anja; Samset, Bjørn Hallvard; Sundal, Anja; Storelvmo, Trude & Joner, Erik (2020). Boklansering: Varm klode, kaldt hode. Løsninger på klimakrisen. Fulltekst i vitenarkiv
• Perilla, Ana Lucia Campaña; Joudeh, Nadeem; Høyer, Henrik; Røyne, Anja; Linke, Dirk & Mikheenko, Pavlo (2020). Probing van der Waals and magnetic forces in bacteria with magnetic nanoparticles. Fulltekst i vitenarkiv Vis sammendrag

  Bioinspired metal-based nanoparticles have potential uses in many applications, but before a possible commercial exploitation, it is important to clarify the pathways of their production and deposition inside the organisms, for example in bacteria. The technique of magnetic force microscopy (MFM) could be used to evaluate the nanoparticles magnetic properties, in addition to allowing tracing their location inside or outside of bacteria, which could help to understand pathways of their biosynthesis. In this work, using MFM and analyzing the interaction of magnetic tip with nanoparticles and bacteria imbedded in resin at different heights above the surface, and comparing gradients of forces recorded by magnetic and non-magnetic tips, a condition was found, which allows to measure pure magnetic response of Pd-Fe nanoparticles. For these nanoparticles, the interplay between magnetic and van der Waals forces is described at small distances to the surface. Experimental data are compared with simulations, based on the calculation of the distribution of magnetic field around a nanoparticle, which defines magnetic force acting on the MFM tip.

• Claxton, James; Joudeh, Nadeem; Røyne, Anja; Linke, Dirk & Mikheenko, Pavlo (2020). Sequential magnetic mapping of bacteria loaded with Pd-Fe nanoparticles. Fulltekst i vitenarkiv Vis sammendrag

  Magnetic nanoparticles are of widespread use in nanotechnology. One of the most unusual are magnetic palladium nanoparticles that combine magnetism with high catalytic activity. These nanoparticles could be obtained biologically by exposing bacteria to a palladium salt. Due to their small size and weak magnetism, however, it is challenging to measure their magnetic properties. One of the solutions to enhance their magnetism is to incorporate a small amount of iron atoms into them. After this procedure, the nanoparticles together with bacteria can be embedded in resin and characterized by the technique of magnetic force microscopy. This technique allows imaging cross-sections of the bacteria with nanoparticles, but cannot give information from the depth of the sample. Here we report on an approach partially solving this problem. Its novelty lies in measurements of consecutive thin slices of resin, which allows mapping cross-sections of individual bacteria and different parts of the material surrounding the same bacterium. An interesting observed feature is the formation of magnetic chains of nanoparticles outside of the bacteria.

• Røyne, Anja (2020). Blir det tomt? Ressurser, forbruk og fremtiden. Fulltekst i vitenarkiv
• Røyne, Anja (2020). Menneskets og økosystemets grunnstoffer i et evig kretsløp? Fulltekst i vitenarkiv
• Røyne, Anja (2020). Menneskets grunnstoffer. Fulltekst i vitenarkiv
• Røyne, Anja & Einevoll, Gaute (2019). Vett og vitenskap: Om grunnstoffer. [Internet]. Podcast. Fulltekst i vitenarkiv
• Røyne, Anja (2019). Menneskets grunnstoffer. Fulltekst i vitenarkiv
• Røyne, Anja (2019). Menneskets grunnstoffer. Fulltekst i vitenarkiv
• Røyne, Anja (2019). Prosalong: Menneskets grunnstoffer. Fulltekst i vitenarkiv
• Røyne, Anja (2019). Klima for dummies. Fulltekst i vitenarkiv
• Røyne, Anja (2019). Menneskets grunnstoffer. Fulltekst i vitenarkiv
• Røyne, Anja (2019). Menneskets grunnstoffer. Fulltekst i vitenarkiv
• Røyne, Anja (2019). Jorda før livet. Fulltekst i vitenarkiv
• Røyne, Anja (2019). Mennesket grunnstoffer. Fulltekst i vitenarkiv
• Røyne, Anja (2019). Hva alt er laget av og hvor det kommer fra. Fulltekst i vitenarkiv
• Røyne, Anja (2019). Menneskets grunnstoffer. Fulltekst i vitenarkiv
• Røyne, Anja (2019). Hva er egentlig verden bygd opp av? Fulltekst i vitenarkiv
• Røyne, Anja (2019). Grunnstoffer: Verdens framtid og deg. Fulltekst i vitenarkiv
• Røyne, Anja (2019). Menneskets grunnstoffer. Fulltekst i vitenarkiv
• Røyne, Anja (2019). Menneskets grunnstoffer. Fulltekst i vitenarkiv
• Røyne, Anja (2019). Historien om verden og grunnstoffene på syv dager. Naturfag. ISSN 1504-4564. Fulltekst i vitenarkiv
• Røyne, Anja (2019). Menneskets grunnstoffer. Fulltekst i vitenarkiv
• Røyne, Anja (2019). Mennesket grunnstoffer. Fulltekst i vitenarkiv
• Røyne, Anja (2019). Fysikkshow for barn. Fulltekst i vitenarkiv
• Røyne, Anja (2019). Menneskets grunnstoffer. Fulltekst i vitenarkiv
• Røyne, Anja (2019). Ekko: Abels Tårn. [Radio]. NRK P2. Fulltekst i vitenarkiv
• Dziadkowiec, Joanna; Javadi, Shaghayegh & Røyne, Anja (2019). Contacts between reactive surfaces. Fulltekst i vitenarkiv
• Vollsnes, Ane Victoria; Røyne, Anja; Leira, Torkjell & Torgersen, Eivind (2019). Regnskogene er ikke jordas lunger – så hvor kommer oksygenet vi puster fra? [Journal]. titan.uio.no. Fulltekst i vitenarkiv
• Razbani, Mohammad Amin; Zehner, Jennifer Simone; Jettestuen, Espen; Røyne, Anja; Sikorski, Pawel & Malthe-Sørenssen, Anders (2019). A pore-scale model of microbially induced calcium carbonate precipitation. Fulltekst i vitenarkiv
• Joudeh, Nadeem; Røyne, Anja; Mikheenko, Pavlo & Linke, Dirk (2019). Bio-Engineered Palladium Nanoparticles (BEDPAN). Fulltekst i vitenarkiv
• Mikheenko, Pavlo; Mikheenko, Iryna; Joudeh, Nadeem; Claxton, J. B.; Røyne, Anja & Linke, Dirk (2019). Imaging magnetism of biologically produced palladium nanoparticles. Fulltekst i vitenarkiv
• Røyne, Anja; Torgersen, Eivind & Tarjem, Guro (2019). Ekko - Grunnstoffer 3:6 titan kan gjøre oss til kyborger. [Radio]. NRK P2. Fulltekst i vitenarkiv
• Røyne, Anja; Torgersen, Eivind & Tarjem, Guro (2019). Ekko - Grunnstoffer 4:6 Aluminium kan forandre verden. [Radio]. NRK P2. Fulltekst i vitenarkiv
• Zehner, Jennifer Simone; Karlsen, Emil; Razbani, Mohammad Amin; Jettestuen, Espen; Malthe-Sørensen, Anders & Wentzel, Alexander [Vis alle 9 forfattere av denne artikkelen] (2019). The quest for bio-concrete: crossing disciplinary boundaries and wrangling bacteria to enable cleaner construction. Fulltekst i vitenarkiv
• Dziadkowiec, Joanna; Zareeipolgardani, Bahareh; Bratvold, Jon E.; Nilsen, Ola; Dysthe, Dag Kristian & Røyne, Anja (2019). Long-range repulsive forces between reactive calcite surfaces are generated due to nucleation in a confined solution. Fulltekst i vitenarkiv
• Røyne, Anja; Torgersen, Eivind & Tarjem, Guro (2019). Ekko - Grunnstoffer 5:6 Det livsviktige fosforet. [Radio]. NRK P2. Fulltekst i vitenarkiv
• Røyne, Anja (2018). Kan vi gå tom for råstoffer? Er plan B å hente dem fra verdensrommet? Aftenposten Viten. ISSN 2464-3033. Fulltekst i vitenarkiv
• Dziadkowiec, Joanna; Javadi, Shaghayegh; Bratvold, Jon E.; Nilsen, Ola & Røyne, Anja (2018). Adhesive and repulsive forces between calcite surfaces. Fulltekst i vitenarkiv
• Perilla, Ana Lucia Campana; Linke, Dirk; Mikheenko, Pavlo & Røyne, Anja (2024). Palladium-based nanoparticles produced by Escherichia coli: Insights into synthesis and physicochemical characterization of microbial nanoparticles. Universitetet i Oslo. Fulltekst i vitenarkiv Vis sammendrag

  Microorganisms such as bacteria can produce a wide range of metallic nanoparticles, including the highly versatile palladium nanoparticles (Pd NPs). Current industrial methods for NP production often require large amounts of energy, use toxic chemicals, and generate waste. Microbial processes offer a green alternative for NP production, and the possibility to engineer these processes using genetic tools. Pd NPs are invaluable tools across numerous exciting applications in medicine, engineering, electronics, and chemistry. Understanding and controlling the synthesis of Pd NPs is crucial as their magnetic and catalytic properties are strongly dependent on their size, shape, and on the presence of other metals such as iron (Fe) that could enhance their performance even further. Surprisingly, little is known about the production of Pd-Fe nanoparticles by bacteria, despite their promising uses. In this thesis, we employed various advanced techniques to characterize Pd and Pd-Fe NPs produced by Escherichia coli bacteria, uncovering valuable insights into their composition, size, localization, and catalytic activity. These results will enable the use of bacterial Pd-Fe NPs as efficient and sustainable catalysts for applications like wastewater treatment and fine chemical synthesis in the future. Additionally, our novel methodology for studying the magnetism of Pd-based NPs directly within bacterial cells opens doors for exciting future research.

• Røyne, Anja & Brekke, Kjell Arne (2023). The economics of nitrogen fertilizer in the green transition. Universitetet i Oslo. Fulltekst i vitenarkiv Vis sammendrag

  Global food production today is critically dependent on synthetic nitrogen fertilizer, the production of which has a significant climate impact. For the fertilizer industry to become part of the ongoing transition to a zero emissions economy, production needs to shift to one of two alternative methods: conventional, natural gas based production with added carbon capture and storage (”blue ammonia”), or replacing natural gas with electrolysis of water based on renewable electricity (”green ammonia”). These options each come with their own set of benefits in the short and long term, and policy mechanisms that may drive the technological transitions along each of the two paths are likely to differ. The aim of this thesis is therefore to combine economic theory with technological insight to better understand what strategies may promote or hinder a desired development. It is useful to view green ammonia as what in the environmental eco- nomics literature is often referred to as a ”breakthrough technology”: a new technology that starts out as more costly than the current, con- ventional alternative, but that may provide the best societal outcome over time. Market mechanisms will typically direct investments toward the more mature technology, resulting in what is often called techno- logical lock-in. Simply raising the price on emissions is most likely not sufficient to break the lock-in. Instead, policy mechanisms are needed to increase the investment level in the breakthrough technology, so that cost reductions due to learning effects can become substantial enough to make the new technology preferable to the conventional alternative. This can be done through direct subsidies to green ammonia producers, or by regulations that increase demand for green ammonia in the agricultural sector and/or emerging new markets, such as the use of ammonia as a fuel in maritime transport. Such regulations may be administratively costly, so countries should weigh their benefit against more simple directed subsidies. Forming coalitions or partnerships can also help reduce the economic burden of single countries in developing a new technology. Economic theory applied to the specific numbers relevant for this industry suggest that gains for coalition members are likely to be moderate compared with the gain for non-cooperating countries. However, in the context of heterogeneous countries, both in terms of their possibility to do technological development and of their historical contributions to climate change, this may still turn out to be a good overall solution.

• Røyne, Anja & Javadi, Shaghayegh (2019). Interaction between two calcite surfaces in aqueous solutions: Study of nano-scale interfacial forces using AFM and SFA. Universitetet i Stavanger. Fulltekst i vitenarkiv Vis sammendrag

  Carbonate-bearing rocks in the upper Earth’s crust are prone to continuous changes under influences of various physical and chemical processes. The macroscopic mechanical strength of carbonates is generally controlled by the cohesion between contacting grains at a molecular scale. These grains deform in contact regions due to the chemistry of pore fluid. The repulsive and attractive forces that perate at the grain contacts may be affected by the dissolution and recrystallization kinetics at the mineral-liquid interfaces. The processes by which the nano-scale interfacial forces are influenced by changing properties of the confined fluid are largely unknown. In this thesis, I investigate these processes and their possible contribution to the strength of calcite-bearing rocks and materials. The Atomic Force Microscope (AFM) and Surface Force Apparatus (SFA) are two powerful tools that provide an opportunity of direct observation of mineral reactions to the contacting fluid and measuring the surface forces at nano-scale in air and liquid environments. In this project, we perform an extended number of experiments using the AFM and SFA to improve our understanding of variation in interfacial forces linked to the strength of calcite and calcite-bearing rocks. In the AFM experiments, we bring an in situ fabricated calcite probe into contact with an opposing freshly cleaved calcite surface in a fluid cell containing aqueous solutions with varying chemical compositions. We also combine the AFM force measurements with a technique called inverse imaging, for in situ simultaneous characterization of the calcite probes. Based on these experiments, we discuss that the possible variation in local topography of contacts, together with a strong dependence on ionic strength of the solution, can explain the variation in strength of calcite rocks in aqueous solutions. With the SFA, we can perform in situ observations of the possible changes in the surfaces via light interferometry technique while measuring the interfacial interactions at nano-scale. At this scale, interactions between contacting surface asperities define the nature of interfacial forces, repulsive or attractive. We discuss how the crystal growth, dissolution and changes in surface roughness affect these interaction forces and their implications on the strength of calcite-bearing rocks.

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