Optimal resource allocation in General Cournot-competitive equilibrium

Conventional economic theory stipulates that output in Cournot competition is too low relative to that which is attained in perfect competition. We revisit this result in a General Cournot-competitive Equilibrium model with two industries that differ only in terms of productivity. We show that in general equilibrium, the more efficient industry produces too little and the less efficient industry produces too much compared to an optimal scenario with perfect competition

The transition in settling velocity of surfactant-covered droplets from the Stokes to the Hadamard-Rybczynski solution

The exact solution for a small falling drop is a classical result by Hadamard and Rybczynski. But experiments show that small drops fall slower than predicted, giving closer agreement with Stokes' result for a falling hard sphere. Increasing the drop size, a transition between these two extremes is found. This is due to surfactants present in the system, and previous work has led to the stagnant-cap model. We present here an alternative approach which we call the continuous-interface model. In contrast to the stagnant-cap model, we do not consider a surfactant advection-diffusion equation at the interface. Taking instead the normal and tangential interfacial stresses into account, we solve the Stokes equation analytically for the falling drop with varying interfacial tension. Some of the solutions thus obtained, e.g. the hovering drop, violate conservation ofenergy unless energy is provided directly to the interface. Considering the energy budget of the drop, we show that the terminal velocity is bounded by the Stokes and the Hadamard-Rybczynski results. The continuous-interface model is then obtained from the force balance for surfactants at the interface. The resulting expressions gives the transition between the two extremes, and also predicts that the critical radius, below which drops fall like hard spheres, is proportional to the interfacial surfactant concentration. By analysing experimental results from the literature, we confirm this prediction, thus providing strong arguments for the validity of the proposed model

Extending a serial 3D two-phase CFD code to parallel execution over MPI by using the PETSc library for domain decomposition

To leverage the last two decades' transition in High-Performance Computing (HPC) towards clusters of compute nodes bound together with fast interconnects, a modern scalable CFD code must be able to efficiently distribute work amongst several nodes using the Message Passing Interface (MPI). MPI can enable very large simulations running on very large clusters, but it is necessary that the bulk of the CFD code be written with MPI in mind, an obstacle to parallelizing an existing serial code. In this work we present the results of extending an existing two-phase 3D Navier-Stokes solver, which was completely serial, to a parallel execution model using MPI. The 3D Navier-Stokes equations for two immiscible incompressible fluids are solved by the continuum surface force method, while the location of the interface is determined by the level-set method. We employ the Portable Extensible Toolkit for Scientific Computing (PETSc) for domain decomposition (DD) in a framework where only a fraction of the code needs to be altered. We study the strong and weak scaling of the resulting code. Cases are studied that are relevant to the fundamental understanding of oil/water separation in electrocoalescers.Comment: 8 pages, 6 figures, final version for to the CFD 2014 conferenc

A robust method for calculating interface curvature and normal vectors using an extracted local level set

The level-set method is a popular interface tracking method in two-phase flow simulations. An often-cited reason for using it is that the method naturally handles topological changes in the interface, e.g. merging drops, due to the implicit formulation. It is also said that the interface curvature and normal vectors are easily calculated. This last point is not, however, the case in the moments during a topological change, as several authors have already pointed out. Various methods have been employed to circumvent the problem. In this paper, we present a new such method which retains the implicit level-set representation of the surface and handles general interface configurations. It is demonstrated that the method extends easily to 3D. The method is validated on static interface configurations, and then applied to two-phase flow simulations where the method outperforms the standard method and the results agree well with experiments.Comment: 31 pages, 18 figure

Everyday life with prostate cancer : a qualitative study of men`s and spouses` experiences

The papers of this thesis are not available in Munin: 1. Ervik, B., Nordøy T. and Asplund K.: 'Hit by waves : living with local advanced or localized prostate cancer treated with Endocrine Therapy or under Active Surveillance', Cancer Nursing (2010), vol.33(5):382-389. Available at http://dx.doi.org/10.1097/NCC.0b013e3181d1c8ea 2. Ervik B. and Asplund K.: 'Dealing with a troublesome body : a qualitative interview study of men’s experiences living with prostate cancer treated with endocrine therapy', European Journal of Oncology Nursing (2012), vol.16(2):103-108. Available at http://dx.doi.org/10.1016/j.ejon.2011.04.005 3. Ervik, B., Nordøy T. and Asplund K.: 'In the middle and on the sideline : the experiences of spouses of men with prostate cancer', Cancer Nursing (2012), Published online before print. Available at http://dx.doi.org/10.1097/NCC.0b013e31824fe1efProstatakreft er den hyppigste kreftformen hos menn i Norge med ca. 4300 nye tilfeller hvert år. De vanligste behandlingsformene ved prostatakreft medfører bivirkninger som impotens og urinlekkasje, som for noen vedvarer resten av livet. Mange menn har korte opphol/konsultasjoner i institusjon ved utredning og behandling og ulike spørsmål viser seg først etter hjemkomst. Hensikten med studien er å belyse menns og ektefellers erfaringer med prostatakreft i hverdagen og sykdommens betydning i forhold til daglige aktiviteter, kroppslige endringer og det ekteskapelig forholdet. Studien har en fenomenologisk hermeneutisk tilnærming og bygger på kvalitative intervju av 13 menn med prostatakreft og 9 ektefeller. Resultatene viser at det å få (prostata) kreft opplevdes som en eksistensiell trussel som medførte usikkerhet for framtiden. Følger av behandling som impotens, nedsatt seksuell lyst og urinlekkasje hadde betydning for mennenes opplevelse av maskulinitet og for forholdet mellom ektefellene. Begge parter uttrykte stor omsorg for hverandre. Noen opplevde at sykdommen medførte større avstand i forholdet, mens andre opplevde at sykdommen førte dem tettere sammen. Andre kroppslige endringer ble en kilde til usikkerhet og uro, og ledet til refleksjoner knyttet til opplevelsen av å være frisk eller å være syk. Mange menn følte seg overlatt til seg selv hjemme med ubesvarte spørsmål. Ektefellene var sentrale støttespillere for mennene. Samtidig opplevde kvinnene å måtte undertrykke egne behov for støtte for å kunne være støttende for sine ektemenn. For noen førte dette til slitenhet over tid. Informasjon, fellesskap, oppmuntring, humor og livsmot var sentrale elementer i mestring av dagliglivet for menn og ektefeller. Begge parter prøvde å leve så normalt som mulig og unngå at sykdommen dominerte dagliglivet. Imidlertid medførte kreftdiagnosen og uroen for framtiden til en ny ettertenksomhet i hverdagen, og begge parter levde med en type ”beredskap” for nye endringer ift utvikling av sykdommen. Prostate cancer, experience, spouse, partner, every day life, sexuality, embodiment, humour, life courage, qualitative, nursing, phenomenology, hermeneuti

Phase behaviour of DNA in presence of DNA-binding proteins

To characterize the thermodynamical equilibrium of DNA chains interacting with a solution of non-specific binding proteins, a Flory-Huggins free energy model was implemented. We explored the dependence on DNA and protein concentrations of the DNA collapse. For physiologically relevant values of the DNA-protein affinity, this collapse gives rise to a biphasic regime with a dense and a dilute phase; the corresponding phase diagram was computed. Using an approach based on Hamiltonian paths, we show that the dense phase has either a molten globule or a crystalline structure, depending on the DNA bending rigidity, which is influenced by the ionic strength. These results are valid at the thermodynamical equilibrium and should therefore be consistent with many biological processes, whose characteristic timescales range typically from 1 ms to 10 s. Our model may thus be applied to biological phenomena that involve DNA-binding proteins, such as DNA condensation with crystalline order, which occurs in some bacteria to protect their chromosome from detrimental factors; or transcription initiation, which occurs in clusters called transcription factories that are reminiscent of the dense phase characterized in this study.Comment: 20 pages, 9 figures, accepted for publication at The Biophysical Journa

Critique of Exaggeration : Thinking Beyond

This study examines the function of exaggeration for thinking beyond the current concepts of God and the human. An example of thinking beyond in philosophy is the exaggeration “beyond being” in Plato’s Republic. In the philosophy of religion, generally, we deal with the questions of God. The present study discerns as an instance of thinking beyond the thinking about God and the human. The study aims to develop and demonstrate the critique of exaggeration as an approach to the thinking beyond. The critique of exaggeration locates and examines the point at which thinking goes beyond the subject at hand, which is also the subject of clear and distinct understanding. The study takes the starting point in Jacques Derrida’s Writing and Difference, and Alexander Garcia Düttmann’s philosophical concept of exaggeration for the analysis of exaggeration in René Descartes’ Meditations on First Philosophy, George Bataille’s Madame Edwarda, and Antonin Artaud’s To Have Done with the Judgement of God. The study demonstrates the decisive role of exaggeration in the creation of concepts. Finally, the study proposes the critique of exaggeration as the approach to the eccentric, transgressive, and extravagant discourses in philosophy and philosophising in literature, art, and theatre

Malnutrition in cancer patients receiving palliative care

Masteroppgave i klinisk ernæringNUCLI395MAMD-NUCL

Experimental and computational studies of water drops falling through model oil with surfactant and subjected to an electric field

The behaviour of a single sub-millimetre-size water drop falling through a viscous oil while subjected to an electric field is of fundamental importance to industrial applications such as crude oil electrocoalescers. Detailed studies, both experimental and computational, have been performed previously, but an often challenging issue has been the characterization of the fluids. As numerous authors have noted, it is very difficult to have a perfectly clean water-oil system even for very pure model oils, and the presence of trace chemicals may significantly alter the interface behaviour. In this work, we consider a well- characterized water-oil system where controlled amounts of a surface active agent (Span 80) have been added to the oil. This addition dominates any trace contaminants in the oil, such that the interface behaviour can also be well-characterized. We present the results of experiments and corresponding two-phase- flow simulations of a falling water drop covered in surfactant and subjected to a monopolar square voltage pulse. The results are compared and good agreement is found for surfactant concentrations below the critical micelle concentration.Comment: 7 pages, 9 figures, to be presented at the ICDL 2014 conferenc