Flow pattern and pressure drop in horizontal viscous oil-water flows

Paper presented to the 10th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Florida, 14-16 July 2014.Despite recent discoveries of light oil in the Brazil's pre-salt layer, about 25% of its' reserves will still consist of viscous oil. In the case of light oil, commercial software are able to provide, with an admissible uncertainty, pressure drop and holdup of oil-water flows, however when they are used for the same flow predictions involving viscous oils there is a large discrepancy between the experimental data and predictions. In this work, experimental data of pressure gradient, characterization of flow patterns in horizontal viscous oil-water flows and spatial transition of the stratified flow to intermittent flow were acquired at the experimental facility of the LETeF (Thermal and Fluids Engineering Laboratory) of the Engineering School of Sao Carlos of the University of Sao Paulo in Brazil. The experimental facility consists of 12 m length glass pipeline of 26 mm i.d. It is equipped with positive displacement pumps and volumetric flow meters for oil and water. Oil with viscosity of 300 mPa.s and density of 845 kg/m³ at 20°C and tap water were the working fluids. A high speed camera was used to film the flow and characterize flow patterns. The movies were taken at transparent sections placed at the pipeline filled with water to reduce distortion effects. The observed flow patterns were: smooth stratified, wavy stratified, stratified with mixture at the interface, drops of oil in water, plug flow (intermittent flow), core-annular flow, and dispersion of oil in water. The pressure drop was measured using a high speed differential pressure transducer from Validyne™. It was observed that as the flow pattern changes, the behaviour of the variation of the pressure drop also changes. The experimental data are being used to improve the two-phase flows models, e.g. the one dimensional two-fluid model.cf201

Encountering religious diversity : multilevel governance of Islamic education in Finland and Ireland

Recent decades have witnessed a change in European governments’ policies from benign neglect to active management of religious diversity, where Islam is often seen as the most challenging for the European social order. However, the ways that this “management” is justified and undertaken varies from country to country and depends on the issues at hand. This paper will take up the issue of Islamic education in Finland and Ireland where it is incorporated into the public school system and where the state has taken an active role in order to control Islam in the field of education. The main argument of this article is that the “management” of Islamic education in both of the above-mentioned countries is ridden with contradictions arising from the difficulty to balance between an emphasis on particular national traditions, on the one hand, and public policies concerning religious diversity, on the other hand. Theoretically, the article will employ the perspective of multilevel governance which helps to widen the perspective from the state as a primary explanatory to different agents of the civil society in encountering religious diversity.Peer reviewe

Amyloids - A functional coat for microorganisms

Amyloids are filamentous protein structures ~10 nm wide and 0.1–10 µm long that share a structural motif, the cross-β structure. These fibrils are usually associated with degenerative diseases in mammals. However, recent research has shown that these proteins are also expressed on bacterial and fungal cell surfaces. Microbial amyloids are important in mediating mechanical invasion of abiotic and biotic substrates. In animal hosts, evidence indicates that these protein structures also contribute to colonization by activating host proteases that are involved in haemostasis, inflammation and remodelling of the extracellular matrix. Activation of proteases by amyloids is also implicated in modulating blood coagulation, resulting in potentially life-threatening complications.

A novel route to trans-THFs and the synthesis of sylvaticin

trans-2,5-Disubstituted-tetrahydrofurans (THFs) are a common structural motif in many biologically active natural products, particularly in the Annonaceous acetogenins. This thesis develops a new route for their synthesis and applies it to the total synthesis of the Annonaceous acetogenin sylvaticin. Chapter 1: Introduction – Synthetic routes to trans-2,5-substituted tetrahydrofurans This chapter reviews methods for the synthesis of trans-2,5-THFs that have been applied to natural products synthesis. Chapter 2: Results & Discussion – A Novel Route to trans-THFs The rearrangement of activated 2,5-disubstituted cis-THFs is reviewed and is developed into a new synthetic method for the synthesis of trans-THFs. The reaction proceeds via a hydride shift mechanism to form an oxonium ion. Intramolecular reduction by a tethered hydrosilane stereoselectively forms the trans-THF. The mechanism of the rearrangement is investigated with the use of different stereoisomers and a deuterium labelling study. A cross-over study is carried out which confirms the reaction occurs via the proposed hydride shift mechanism. Chapter 3: Introduction – The Annonaceous Acetogenins This chapter introduces the Annonaceous acetogenins, a biologically active class of natural products often found with THF rings in their structure. The three key areas for their synthesis are explored- the synthesis of the THF core, the synthesis of the butenolide ring, and their coupling. Chapter 4: Results & Discussion – The Synthesis of Sylvaticin The Annonaceous acetogenin sylvaticin is introduced, and its isolation in nature and biological activity reviewed. With the aid of a model system study to extend the scope of the reaction, the methodology developed in Chapter 2 is then applied to the synthesis of sylvaticin. The synthesis, the first to be reported, is completed in a total of 19 linear steps starting from commercially available tetradecatetraene. In order to prove the obtained structure is that found in nature, a comprehensive investigation is undertaken using Mosher ester derivatives and the synthesis of its bis-epimer, 4,36-epi,epi sylvaticin. Chapter 5: Experimental Full experimental procedures and characterisation of compounds are reported