Effect of Moisture, Hydrogen, and Water–Gas Shift Reaction on the Prereduction Behavior of Comilog and Nchwaning Manganese Ores

The ore–gas reactions in the prereduction zone in a ferromanganese furnace are largely decisive of the overall energy efficiency, carbon consumption, and climate gas emissions in ferromanganese production. An increased understanding of the prereduction zone is thus vital for optimization of the furnace operation. The ore–gas reactions are well known to be governed by kinetics rather than thermodynamics. The raw materials contain various amounts of both chemically bound and surface moisture when fed to the furnace, which may influence the reaction kinetics. This paper presents the investigation of the potential influence of moisture on the prereduction kinetics of two commercial manganese ores, i.e., Comilog and Nchwaning. TGA experiments were carried out by comparing dry and wet ore, as well as introducing H2(g) or H2O(g) to the CO–CO2 gas mixture.publishedVersio

Humor i romantisk text : om Jean Pauls estetik i svensk romantik: C.F. Dahlgrens Mollbergs epistlar (1820), C.J.L. Almqvists Amorina (1822) och C. Livijns Spader Dame (1825)

The three works analyzed here were published at the culmination of Swedish romanticism. The strange mixture of the high and the low, the sacred and the profane that is typical for them has been an interesting challenge for literary scholars. For instance, in older research one sometimes spoke of poor handwork, or bad taste of the writers or it was explained that these works were a stage between the end of romanticism and the beginning of realism. A common approach in the last years has been to leave such biographical and contextual discussions aside to investigate these semantic tensions as something typical of all forms of literary texts. However, the aim here has been to analyze some of the tension-filled passages in these works for their humor by using the cognitive humor theory of linguistics which describes the phenomenon as a bifurcated logical process – first the creation of discrepancy in the text being followed by the insight that the logical opposites may be related to each other when using the logic of the absurd. This analysis combines the approaches of the cognitive humor theory with the terminology and analytic model of Michael Riffaterre developed in his Semiotics of Poetry (1978), where he shares the theoretical views of the linguists but focuses on literary texts. The results of this analysis are in a second stage related to a contemporary discussion of humor, above all the stand taken by the German writer Jean Paul in his Vorschule der Ästhetik (1804) and demonstrated in his novels Titan (1800-1803) and Des Luftschiffers Giannozzo Seebuch (1801). The first step taken in the thesis shows that the tensions in the three chosen texts can be understood as deliberate, that is, as a form of humor, and that it can be said that these three texts share a common aesthetic. In opposition to the view often found in research that the texts are a transition from the romantic to realism the second comparative part of the thesis shows that this humoristic aesthetic in many ways is close to the discussion of humor and of Witz to be found in Jean Pauls Vorschule der Ästhetik. A fruitful result of this analysis is the important place Christianity takes in this humoristic aesthetic. This partly opens new fields for research in the functions of allusions in these romantic texts to the Old and New Testaments, but also in the role that emblems and the tradition of devotional literature play in these works

Fåmansföretagsreglerna – från stopp till topp (och tillbaka?)

Uppsatsen redogör för hur fåmansföretagsreglernas syfte, ändamål och värderingar har förändrats under tidsperioden 1991 till 2015, samt göra en förutsägelse hur fåmansföretagsreglerna kommer förändras i framtiden. Förutom fåmansföretagsreglernas instiftande 1991 behandlas 2006 och 2014 års lagändringar. För att besvara frågeställningarna har framförallt förarbeten studerats. Fåmansföretagsreglerna började med att 1991 vara en stopplagstiftning vars primära syfte var att motverka inkomstomvandling. Reglerna gjordes succesivt mer generösa och 2006 var den verkliga vändpunkten då syftet ändrades från att inte bara motverka inkomstomvandling, utan att också stimulera mindre och nystartade fåmansföretag. Reglerna gjordes så fördelaktiga för skattskyldig att denne i många fall hellre bedriv verksamhet i ett fåmansföretag än någon annan bolagsform. Fåmansföretagsreglerna blev så pass förmånliga att lagstiftaren var tvungna att införa vissa restriktioner 2014 som gjorde reglerna mindre förmånliga för att motverka felanvändning av de förmånliga reglerna. I ljuset av det nu liggande kommittédirektivet och de olika fåmansföretagsreglerna under tidsperioden 1991 till 2015, kan de framtida fåmansföretagsreglerna förutsägas. Att lagstiftaren stramar åt reglerna och gör de mindre förmånliga är ganska troligt. Lagstiftaren kommer troligtvis försöka göra reglerna mer preventiva utan att för den skull bli lika preventiva som 1991 års lagstiftning, men samtidigt bibehålla syftet att stimulera mindre och nystartade fåmansföretag

Reaction Rate Analysis of Manganese Ore Prereduction in CO-CO2 Atmosphere

publishedVersio

TuNet: End-to-end Hierarchical Brain Tumor Segmentation using Cascaded Networks

Glioma is one of the most common types of brain tumors; it arises in the glial cells in the human brain and in the spinal cord. In addition to having a high mortality rate, glioma treatment is also very expensive. Hence, automatic and accurate segmentation and measurement from the early stages are critical in order to prolong the survival rates of the patients and to reduce the costs of the treatment. In the present work, we propose a novel end-to-end cascaded network for semantic segmentation that utilizes the hierarchical structure of the tumor sub-regions with ResNet-like blocks and Squeeze-and-Excitation modules after each convolution and concatenation block. By utilizing cross-validation, an average ensemble technique, and a simple post-processing technique, we obtained dice scores of 88.06, 80.84, and 80.29, and Hausdorff Distances (95th percentile) of 6.10, 5.17, and 2.21 for the whole tumor, tumor core, and enhancing tumor, respectively, on the online test set.Comment: Accepted at MICCAI BrainLes 201

Hole concentration in a diluted ferromagnetic semiconductor

We consider a mean-field approach to the hole-mediated ferromagnetism in III-V Mn-based semiconductor compounds to discuss the dependence of the hole density on that of Mn sites in Ga_{1-x}Mn_xAs. The hole concentration, p, as a function of the fraction of Mn sites, x, is parametrized in terms of the product m*J_{pd}^2 (where m* is the hole effective mass and J_{pd} is the Kondo-like hole/local-moment coupling), and the critical temperature Tc. By using experimental data for these quantities, we have established the dependence of the hole concentration with x, which can be associated with the occurrence of a reentrant metal-insulator transition taking place in the hole gas. We also calculate the dependence of the Mn magnetization with x, for different temperatures (T), and found that as T increases, the width of the composition-dependent magnetization decreases drammatically, and that the magnetization maxima also decreases, indicating the need for quality-control of Mn-doping composition in diluted magnetic semiconductor devices.Comment: 4 pages, 3 figures, RevTeX 3; Fig. 1 changed, new references adde

Structural and magnetic properties of GaMnAs layers with high Mn content grown by Migration Enhanced Epitaxy on GaAs(100) substrates

We have grown the ferromagnetic semiconductor GaMnAs containing up to 10% Mn by migration enhanced epitaxy at a substrate temperature of 150^oC. The alternate supply of As2 molecules and Ga and Mn atoms made it possible to grow single crystalline GaMnAs layers at very low substrate temperature, at which conventional molecular beam epitaxial growth under excess As supply is not possible due to As condensation. Secondary ion mass spectroscopy and X-ray diffraction measurements confirmed a higher Mn content in the films grown by this method in comparison to the GaMnAs layers grown by low temperature molecular beam epitaxy. The lattice constant of hypothetical zinc-blende structure MnAs is determined to be 5.9 \AA, which deviates somewhat from previously reported values. This deviation is ascribed to growth-condition dependent density of point defects. It is stressed that this effect must be taken into account for any assessment of Mn content from X-ray diffraction data. Magnetization measurements showed an onset of ferromagnetic ordering around 75 K for the GaMnAs layer with 10% Mn. This means that the trend of falling Curie temperatures with increasing Mn concentrations above 5.5% is broken. We tentatively assign this to the variation of the carrier concentration, including contributions from donor and acceptor centers formed by antisite defects and Mn doping, and increased density of magnetically active Mn ions.Comment: No LaTeX source; gzipped postscript text + 3 gzipped postscript figure