154 research outputs found
Discrepancy bounds for normal numbers generated by necklaces in arbitrary base
Mordechay B. Levin has constructed a number which is normal in base
2, and such that the sequence
has very small discrepancy . Indeed we have . This construction technique of Levin was
generalized by Becher and Carton, who generated normal numbers via perfect
nested necklaces, and they showed that for these normal numbers the same upper
discrepancy estimate holds as for the special example of Levin. In this paper
now we derive an upper discrepancy bound for so-called semi-perfect nested
necklaces and show that for the Levin's normal number in arbitrary prime base
this upper bound for the discrepancy is best possible, i.e., with for infinitely many . This result
generalizes a previous result where we ensured for the special example of Levin
for the base , that is best
possible in . So far it is known by a celebrated result of Schmidt that for
any sequence in , with for infinitely
many . So there is a gap of a factor in the question, what is the
best order for the discrepancy in that can be achieved for a normal number.
Our result for Levin's normal number in any prime base on the one hand might
support the guess that is the best order in
that can be achieved by a normal number, while generalizing the class of known
normal numbers by introducing e.g. semi-perfect necklaces on the other hand
might help for the search of normal numbers that satisfy smaller discrepancy
bounds in than .Comment: 29 page
Heat transfer challenge and design evaluation for a multi-stage temperature swing adsorption (TSA) process
Functionalized solid amine-based temperature swing adsorption (TSA) processes have recently been proposed as a potential way to reduce the energy-penalty of post-combustion carbon capture processes (1). If TSA is to be carried out at large scale and with high energy-efficiency, continuously operated counter-current contactors are required for thermodynamic reasons. This could, generally, be achieved by using moving bed contactors. However, the heat exchange requirement of TSA is significant and heat transfer is poor in fixed and moving beds. Therefore, multi-stage fluidized bed contactors with counter-current flow of solids and gas phase and immersed heat exchange surfaces may solve the heat transfer challenge while maintaining the thermodynamic process requirements. Experiments have shown that adsorption and desorption kinetics of suitable functionalized amine sorbents are fast and equilibrium loadings are practically reached in the stages (1). Thus, heat exchange is the dominant limiting factor for a practical stage design in multi-stage fluidized bed TSA. The present work rationally develops design requirements for TSA stages based on the necessary heat exchange rates. The considered particles are Geldart Type B (diameter 200-300 µm, particle density 1000-1500 kg/m3). Scalability of the design proposal is considered and vertically orientated heat exchanger tubes are compared to horizontal tube bundles. The net movement and mixing of particles within the bubbling bed stage must be maintained in spite of the emulsified heat exchangers (possible dead zones in the area of the tube bundles). It is shown that the pressure drop of multi-stage fluidized bed TSA units for flue gas CO2 capture is practically determined by the heat exchange requirement and not by the space-time of the solids for the adsorption. Future work will employ a bubbling fluidized bed heat exchange testing device for optimization of the heat exchanger geometry with respect to heat transfer rates and particle residence time distribution in the stage. Heat exchange measurement devices have been presented recently in literature for horizontal tube bundles and Geldart Type A particles (2), but the importance of the heat exchanger issue in continuous fluidized bed TSA requires the detailed investigation for the Geldart B range, potentially considering the macroscopic particle movement relative to the heat exchangers within each individual TSA stage.
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Die Festivalisierung der Stadt
Diese Diplomarbeit beschäftigt sich mit der „Stadt“ und der Festivalisierung in der Stadt. Hierbei werden u.a. die Themen „Entwicklung der Stadt“, „Stadtpolitik“, „Stadtplanung“, „Stadtmarketing“, aber auch wichtige Parameter der Festivalisierung, wie z.B. deren Entstehung, die Gründe für die Festivalisierung, ihre Funktionen und ihre Alternativen behandelt.
Ein Hauptpunkt dieser Diplomarbeit ist die Festivalisierung der Stadt Wien, wobei hier nicht nur der Rathausplatz behandelt und analysiert wird, sondern auch viele andere Locations bzw. Feste Wiens (Heldenplatz, Donauinselfest, Wiener Stadtfest, Wiener Kirtage,...).
Der Stadt Wien stehen für die Festivalisierung die „stadt-wien-marketing-und-prater-service-gmbh“ und der Wiener Tourismusverband „WienTourismus“ zur Verfügung.
Um die Entwicklung der Festivalisierung veranschaulichen zu können, wurde in dieser Arbeit als Beispiel der Wiener Rathausplatz gewählt, da man in den letzten Jahren feststellen konnte, dass der Rathausplatz immer mehr bespielt wird bzw. das ganze Jahr hindurch „verbaut“ ist.
Der Wandel dieses Platzes vom großen Parkplatz zur wichtigsten Event-Location mit den großen Veranstaltungen „Adventzauber“ (1986), „Silvesterpfad“ (1990/91), „Opern Filmfestival“ (1991) und „Eistraum“ (1996) dauerte ca. 25 Jahre. Ab dem Ende der 1990er Jahre ist dieser Platz bereits eine nahezu 365-Tage bespielte Location, die nur noch sehr wenige Zeitfenster für weitere Veranstaltungen bietet und daher kaum noch eine quantitative Steigerung zulässt. Heute kann das Interesse der Bürger bzw. der Touristen nur durch eine qualitative Verbesserung des Veranstaltungsprogramms weiterhin gesteigert bzw. erhalten werden
Expression of the transcriptional regulator Egr-1 in experimental glomerulonephritis: Requirement for mesangial cell proliferation
Expression of the transcriptional regulator Egr-1 in experimental glomerulonephritis: Requirement for mesangial cell proliferation. The early growth response gene-1 (Egr-1), a zinc finger transcriptional regulator, was induced in a rat model of mesangioproliferative glomerulonephritis (GN). Northern blot analysis revealed a maximal 14.9-fold increase in glomerular Egr-1 mRNA at day 6 of GN. By immunohistochemistry Egr-1 protein expression was demonstrated to be mainly confined to glomerular mesangial cells (MC). To test whether Egr-1 directly regulates MC proliferation, cultured MCs were stimulated with platelet-derived growth factor (PDGF) after preincubation with different Egr-1 antisense oligonucleotides (ASOs). PDGF-induced Egr-1 mRNA levels were inhibited by up to 75% and protein levels by up to 91%. In addition Egr-1-specific ASOs blocked PDGF-induced rise in 3H-thymidine uptake by 83% and almost completely abrogated increase in MC number. We conclude that Egr-1 induction is of critical importance for PDGF-induced mitogenic signaling in MCs, and inhibition of Egr-1 in vivo may offer an approach to oppose glomerular MC proliferation in glomerular inflammatory disease
Prognose der österreichischen Wirtschaft 1997/98: Jahresmodell LIMA/97 ; Ökonometrisches Forschungsprogramm des Instituts für Höhere Studien
aus dem Inhaltsverzeichnis: Einleitung und Zusammenfassung; Die internationale Konjunktur; Die österreichische Außenwirtschaft; Perspektiven der Inlandskonjunktur; Monetäre Prognose
Critical and direct involvement of the CD23 stalk region in IgE binding
BackgroundThe low-affinity receptor for IgE, FcεRII (CD23), contributes to allergic inflammation through allergen presentation to T cells, regulation of IgE responses, and enhancement of transepithelial allergen migration.ObjectiveWe sought to investigate the interaction between CD23, chimeric monoclonal human IgE, and the corresponding birch pollen allergen Bet v 1 at a molecular level.MethodsWe expressed 4 CD23 variants. One variant comprised the full extracellular portion of CD23, including the stalk and head domain; 1 variant was identical with the first, except for an amino acid exchange in the stalk region abolishing the N-linked glycosylation site; and 2 variants represented the head domain, 1 complete and 1 truncated. The 4 CD23 variants were purified as monomeric and structurally folded proteins, as demonstrated by gel filtration and circular dichroism. By using a human IgE mAb, the corresponding allergen Bet v 1, and a panel of antibodies specific for peptides spanning the CD23 surface, both binding and inhibition assays and negative stain electron microscopy were performed.ResultsA hitherto unknown IgE-binding site was mapped on the stalk region of CD23, and the non–N-glycosylated monomeric version of CD23 was superior in IgE binding compared with glycosylated CD23. Furthermore, we demonstrated that a therapeutic anti-IgE antibody, omalizumab, which inhibits IgE binding to FcεRI, also inhibited IgE binding to CD23.ConclusionOur results provide a new model for the CD23-IgE interaction. We show that the stalk region of CD23 is crucially involved in IgE binding and that the interaction can be blocked by the therapeutic anti-IgE antibody omalizumab
Structure of the double-stranded DNA-binding type IV secretion protein TraN from Enterococcus
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