Tankesett og førestellingar i Danmark-Noreg kring slavehandelen og slaveriet i perioden 1750-1820.

Samandrag: I denne masteroppgåve har eg sett på tankesett og førestellingar om slaveri og slavehandel i Danmark-Noreg før, under og etter den 14. forordning av 1792, altså vedtaket om avskaffinga av slavehandelen i Danmark-Noreg og i dansk-norsk Vestindien. Tema for denne oppgåva er kva argument og informasjon ein kan finne i perioden 1750-1820, og korleis dette representer mentaliteten, altså meiningar, tankar og kjensler kring slavehandelen og slaveriet i samtida. Eg har brukt kjelder som er tilgjengelege på Nasjonalbiblioteket sine nettsider. Dette inkluderer reisedagbøker, aviser, bøker og andre sekundære kjelder frå samtida. Desse kjeldene har gitt innsikt i kva argumentasjon som vart brukt for og i mot slaveriet og slavehandelen, og kva informasjon som var i fokus. Det har vore viktig i dette arbeidet å vurdere desse kjeldene i samanheng med den varierande grada av ytrings- og trykke-fridom som var i Danmark-Noreg i perioden. Oppgåva syner at det fantes ei rekkje ytringar knytt til slavehandel og slaveri. Dette var ytringar som bidrog til å spreie informasjon og tankesett kring slavehandel og slaveri. Kjeldene syner også til førestellingar om at slavehandelen var naturleg. Der var også førestellingar om at slavehandelen og slaveriet var naudsynt for kristning og sivilisering av afrikanarane. På same måte viser ytringane også at der var motstandarar som meinte at slavehandelen og slaveriet var i strid med humanismen. Vi ser og at der er forskjellege økonomiske syn i samtida, der lønsamheita og fordelaktigheita vert sett opp mot kvarandre. I den endelege avskaffinga, var det nettopp tankesetta og førestellingane om humanisme og lønsamheit som vart viktige, medan religiøse tankesett som hadde vore mykje brukt for å legitimere slavehandelen, vart lagt mindre vekt på i den 14. forordninga av 1792

Tankesett og førestellingar i Danmark-Noreg kring slavehandelen og slaveriet i perioden 1750-1820

I denne masteroppgåve har eg sett på tankesett og førestellingar om slaveri og slavehandel i Danmark-Noreg før, under og etter den 14. forordning av 1792, altså vedtaket om avskaffinga av slavehandelen i Danmark-Noreg og i dansk-norsk Vestindien. Tema for denne oppgåva er kva argument og informasjon ein kan finne i perioden 1750-1820, og korleis dette representer mentaliteten, altså meiningar, tankar og kjensler kring slavehandelen og slaveriet i samtida. Eg har brukt kjelder som er tilgjengelege på Nasjonalbiblioteket sine nettsider. Dette inkluderer reisedagbøker, aviser, bøker og andre sekundære kjelder frå samtida. Desse kjeldene har gitt innsikt i kva argumentasjon som vart brukt for og i mot slaveriet og slavehandelen, og kva informasjon som var i fokus. Det har vore viktig i dette arbeidet å vurdere desse kjeldene i samanheng med den varierande grada av ytrings- og trykke-fridom som var i Danmark-Noreg i perioden. Oppgåva syner at det fantes ei rekkje ytringar knytt til slavehandel og slaveri. Dette var ytringar som bidrog til å spreie informasjon og tankesett kring slavehandel og slaveri. Kjeldene syner også til førestellingar om at slavehandelen var naturleg. Der var også førestellingar om at slavehandelen og slaveriet var naudsynt for kristning og sivilisering av afrikanarane. På same måte viser ytringane også at der var motstandarar som meinte at slavehandelen og slaveriet var i strid med humanismen. Vi ser og at der er forskjellege økonomiske syn i samtida, der lønsamheita og fordelaktigheita vert sett opp mot kvarandre. I den endelege avskaffinga, var det nettopp tankesetta og førestellingane om humanisme og lønsamheit som vart viktige, medan religiøse tankesett som hadde vore mykje brukt for å legitimere slavehandelen, vart lagt mindre vekt på i den 14. forordninga av 1792

Microfluidic Study on the Attachment of Crude Oil Droplets to Gas Bubbles

Gas flotation is often used during treatment of the oilfield produced water. It relies on the generation of gas bubbles and their attachment to oil drops, for example, by forming an oil film on the surface of a gas bubble. In this paper, we present a microfluidic technique for investigating the attachment of crude oil drops to gas bubbles through the spreading mechanism. The developed method allowed us to systematically study the effect of the oil, water, and gas phases, where the investigated parameter was the amount of oil droplets attached to gas bubbles through spreading. The highest attachment efficiency was observed at low or neutral pH. By reducing the salinity, the electrostatic repulsion increased, which had a negative effect on the attachment. The presence of dissolved components stabilized the oil drops and gas bubbles, which decreased their attachment through spreading. Replacing nitrogen with methane improved the attractive interactions between bubbles and oil droplets, enhancing the attachment of oil. The results confirm the potential of microfluidics in studying bubble–droplet interactions, relevant for industrial processes

Effect of Low-Molecular-Weight Alcohols on Emulsion Stabilization with Lignosulfonates

Lignosulfonates are biobased surfactants and specialty chemicals, which are described as water-soluble polyelectrolyte macromolecules that are generated during the sulfite pulping of lignocellulose biomass. Due to their amphiphilic nature, lignosulfonates have made their way into various applications, such as plasticizers, dispersants, and suspension or emulsion stabilizer. The stabilization efficiency for oil-in-water emulsions is affected, among other aspects, by the presence of alcohols. Low-molecular-weight alcohols can improve the performance of lignosulfonates; however, the effects of such additive have not yet been fully explored. In this article, we hence studied emulsion stability in dependence of alcohol concentration and other parameters, such as salinity. One or two regions of improved stability were found, which occurred at approximately 0.001–0.01 M alcohol in water, and in some cases additionally at 1–3 M. The four lignosulfonate samples responded distinctly to the alcohol additives. Little difference was found for varying lignosulfonate concentration or the alcohol type, that is, methanol, ethanol, or 2-propanol. Adding ethanol at high salinity (720 mM NaCl) showed a destabilizing effect. A decrease in interfacial tension was noted when adding 1 M ethanol or more, but the surface pressure of lignosulfonates decreased progressively at 0.3 M ethanol and above. These effects are counteracting, which could explain why increasing alcohol concentration would either enhance or impair stability. Overall, emulsion stability was affected by concentration effects and not cosurfactant action of the alcohols. Composition changes can influence the dielectric properties of the bulk solvent, further affecting the anionic functional groups, which was evidenced by alcohol addition affecting the lignosulfonates with lower hydrophobicity more strongly and by ethanol exhibiting the destabilizing effect at high salinity. In conclusion, adding low-molecular-weight alcohols may hence influence the behavior of lignosulfonates and render them more accessible for interactions with hydrophobic interfaces

Sol-Gel Synthesis of Non-Silica Monolithic Materials

Monolithic materials have become very popular because of various applications, especially within chromatography and catalysis. Large surface areas and multimodal porosities are great advantages for these applications. New sol-gel preparation methods utilizing phase separation or nanocasting have opened the possibility for preparing materials of other oxides than silica. In this review, we present different synthesis methods for inorganic, non-silica monolithic materials. Some examples of application of the materials are also included

Microfluidic Investigation of Crude Oil Droplet Coalescence: Effect of Oil/Water Composition and Droplet Aging

The coalescence between crude oil droplets is a major factor influencing the efficiency of most produced water treatment processes. As the droplets grow bigger in size, it is easier to remove them from the continuous water phase, which will improve the quality of produced water and help meet increasingly stricter environmental and process regulations. Here, we investigate the coalescence process of crude oil drops in water with the use of previously reported microfluidic tools. It was shown that the composition of both oil and water phases heavily impacts the merging between droplets, both outcome (final droplet size distribution) and the kinetics of the phenomena (coalescence time). In the droplet aging experiments, the coalescence was always most extensive for the droplets with the shortest aging time, while the coalescence typically decreased with increasing droplet size distribution; however, this was oil-specific. Overall, the results underline the importance of crude oil and produced water chemistries during the water treatment process

Lignosulfonate Salt Tolerance and the Effect on Emulsion Stability

In this article, we adapted and compared methods to assess lignosulfonates for technical applications. Salt-induced agglomeration and precipitation were studied via mechanical separation and subsequent UV spectrometry. The effect of lignosulfonates on emulsion stability was investigated in two steps: measuring the amount of oil separated after centrifugation and subjecting the remaining emulsion to shear in a rheometer. To complement the results, interfacial tension (IFT) was measured by the spinning drop technique, and the droplet size distribution was determined via a laser scattering technique. The observed trends in lignosulfonate salt tolerance and emulsion stabilization efficiency were opposite; that is, samples with low salt tolerance generally exhibited better emulsion stabilization and vice versa. This tendency was further matched by the hydrophobic characteristic of the lignosulfonates. The droplet size distributions of lignosulfonate-stabilized emulsions were similar. The effect of lignosulfonates on IFT depended on the oil phase and sample concentration. As a general trend, the IFT was lower for lignosulfonates with low average molecular weights. It was concluded that the adapted techniques allowed for detailed assessment of lignosulfonates with respect to salt tolerance and emulsion stabilization. In addition, it was found that the suitability for these applications can to some extent be predicted by the analytical data

Adsorption of crude oil components at mineral surfaces followed by quartz crystal micro-balance and contact angle measurements: The effect of oil composition, simulated weathering and dispersants

Improved knowledge of interactions between crude oil and solid surfaces is of great importance for understanding oil spill responses as well as oil spill behavior on land and in the near-shore environment. Here, the goal was to study how crude oils with various physicochemical properties interacted with model shoreline surfaces. In addition, the influence of simulated weathering and addition of dispersants was investigated for selected crude oils. A quartz crystal microbalance was used to follow the adsorption from 13 different crude oils on silica, aluminosilicate, and calcium carbonate surfaces, whereas the corresponding wettability alterations were followed by contact angle measurements. The polar crude oil components adsorbed in considerably higher amounts on the calcium carbonate surfaces than on the silica and aluminosilicate surfaces. The simulated weathering of oils resulted in increased adsorption onto both the silica and aluminosilicate surfaces, whereas it had a little effect on the calcium carbonate surface. The presence of dispersants generally reduced the amounts adsorbed on the surfaces. In the presence of seawater, the crude oil with a higher total acid number interacted strongest with the calcium carbonate surface.acceptedVersio

Viscoelastic properties of interfacial lignosulfonate films and the effect of added electrolytes

New evidence is presented, which confirmed interfacial gelling of lignosulfonates in presence of di- and trivalent cations. In this article, the viscoelastic properties of lignosulfonate films at the water-xylene interface were studied by dilatational interfacial rheology and interfacial shear rheology. Both techniques showed that increasing lignosulfonate concentration would first increase and then decrease the interfacial modulus. The same trend was observed for increasing salinity. The maximum interfacial modulus corresponded with lignosulfonate aggregation or precipitation and accounted for the best emulsion stability. The film strength increased progressively with the cation charge number. It was argued that multivalent cations provided intermolecular bridging between lignosulfonate molecules, which increased film strength and led to gelling. The decrease of interfacial film strength at high salinity was explained by two mechanisms: (1) For sodium cations, the polyelectrolyte contraction at high ionic strength yielded screening of the functional groups, which are deemed responsible for attractive interactions between lignosulfonate molecules or aggregates. (2) For calcium and aluminum cations, precipitation would reduce the effective bulk concentration, yielding a lower surface coverage. Modelling of the interfacial properties was conducted in addition, which showed that lignosulfonate adsorption was not diffusion-controlled and that lignosulfonate aggregation was affecting the adsorption process. In conclusion, our results revealed a more detailed picture of the mechanisms, which govern the interfacial behavior and properties of lignosulfonates

Viscoelastic properties of interfacial lignosulfonate films and the effect of added electrolytes

New evidence is presented, which confirmed interfacial gelling of lignosulfonates in presence of di- and trivalent cations. In this article, the viscoelastic properties of lignosulfonate films at the water-xylene interface were studied by dilatational interfacial rheology and interfacial shear rheology. Both techniques showed that increasing lignosulfonate concentration would first increase and then decrease the interfacial modulus. The same trend was observed for increasing salinity. The maximum interfacial modulus corresponded with lignosulfonate aggregation or precipitation and accounted for the best emulsion stability. The film strength increased progressively with the cation charge number. It was argued that multivalent cations provided intermolecular bridging between lignosulfonate molecules, which increased film strength and led to gelling. The decrease of interfacial film strength at high salinity was explained by two mechanisms: (1) For sodium cations, the polyelectrolyte contraction at high ionic strength yielded screening of the functional groups, which are deemed responsible for attractive interactions between lignosulfonate molecules or aggregates. (2) For calcium and aluminum cations, precipitation would reduce the effective bulk concentration, yielding a lower surface coverage. Modelling of the interfacial properties was conducted in addition, which showed that lignosulfonate adsorption was not diffusion-controlled and that lignosulfonate aggregation was affecting the adsorption process. In conclusion, our results revealed a more detailed picture of the mechanisms, which govern the interfacial behavior and properties of lignosulfonates