197,832 research outputs found
Shear-induced particle segregation in binary mixtures: Verification of a percolation theory
No full textGranular materials composed of different-sized grains may experience undesired segregation. Segregation is detrimental for a lot of industries because it leads to an increase in production costs and wastes. For these reasons, the segregation phenomena have been intensively studied in the last decades, and a lot of models have been provided by many researchers. However, these models are mainly based on empirical relations rather than physical considerations. This paper aims to confirm the main assumptions made by Volpato, Tirapelle, and Santomaso (2020) in their percolation theory by means of DEM simulations. The simulated geometry is a tilting shear box filled with few tracer particles in a bed of coarser sized grains, and simulations are performed for a range of tilting frequencies and size ratios. The results provide meaningful insight on the mathematical model parameters and allow us to say that the percolation theory relies on physically consistent assumptions
A moralidade vinculada à ação comunicativa e ao direito em Habermas
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Filosofia e Ciências Humanas, Programa de Pós-graduação em Filosofia, Florianópolis, 2010Neste trabalho investigar-se-á a moralidade proposta por Jürgen Habermas no sentido de determinar a relação desta com a ação comunicativa e com o sistema jurídico defendidos por este autor. Para isso, inicialmente, se verificará por que esse autor considera que sua ação comunicativa é capaz de obter consensos racionais como solução para conflitos, entre eles, conflitos morais. O que implica, entre outras coisas, na demonstração do princípio universal de sua ética e o que defende por princípio do discurso. Este último definido por ele como necessário de ser respeitado não só na solução de conflitos morais, mas também na solução do que essa teoria compreende por conflitos éticos e por conflitos pragmáticos. Tal defesa, conforme se observará aqui, é um dos quesitos que essa teoria respeita para vincular os conteúdos justificados por meio dela à condição histórica dos indivíduos sobre os quais se aplica. Investigar-seá a análise habermasiana de críticas de Hegel a Kant para verificar por que essa ética considera essa vinculação necessária para a efetivação dos seus consensos morais, bem como também para verificar por que Habermas considera que realiza essa vinculação. Porém, a pluralidade cultural presente nas sociedades pós-tradicionais obriga a este autor lançar mão de um sistema jurídico para a moralidade se realizar nessas. Analisar-se-á aqui esse sistema de modo a se verificar como esse possibilita o uso da argumentação racional para a obtenção de suas normas, o que implica na compreensão do princípio democrático habermasiano, e de como, por meio da coação jurídica, contribui para a efetivação e para a própria obtenção dessas normas de modo que a moralidade seja respeitada nesses processos.This thesis investigated the morality as proposed by Jürgen Habermas in order to determine its relation to communicative action and the legislative system, as defended by the author. To achieve that, at first, the author's observation was verified to comprehend why he believes communicative action can obtain rational consensus as conflict solution, such as, moral conflicts. What has been brought about as a consequence to Habernas demonstration of ethics universal principle, which he defends as discourse principle: defined as necessary of respect, not only to solve moral conflicts, but also, to solve what the theory comprehends as ethical and pragmatical conflicts. Such argument has been observed as one of the aspects employed in the theory to bond the defended contents over which it is applied. Hebermas analysis on Hegel's and Kant's critiques was also investigated to verify why does ethics consider the correlation necessary to moral consensus effectiveness, as well as to verify why does it consider and performs this correlation. However, post-traditional societies cultural plurality has required the author to account for a legislative system to moralitys achievement on such contexts. This system was analyzed in order to verify the formulation of possibilities of rational argumentation to obtain its rules, which implied on the understanding of Habermas democratic principle as well as on how judicial coercion contributes to these rules effectiveness and achievement so that morality came to be respected in these processes
Monstrous BPS-algebras and the superstring origin of moonshine
No full textWe provide a physics derivation of Monstrous moonshine. We show that the McKay-Thompson series Tg, g ∈ M, can be interpreted as supersymmetric indices counting spacetime BPS-states in certain heterotic string models. The invariance groups of these series arise naturally as spacetime T-duality groups and their genus zero property descends from the behaviour of these heterotic models in suitable decompactification limits. We also show that the space of BPS-states forms a module for the Monstrous Lie algebras mg, constructed by Borcherds and Carnahan. We argue that mg arise in the heterotic models as algebras of spontaneously broken gauge symmetries, whose generators are in exact correspondence with BPS-states. This gives mg an interpretation as a kind of BPS-algebra
Synthesis of a group of novel Xanomeline/77-LH-28-1 hybrid ligands and their FRET investigation at muscarinic acetylcholine receptor subtypes
No full textIn connection with our interest in investigating novel rationally designed bitopic (i.e., orthosteric/allosteric) derivatives targeting muscarinic acetylcholine receptor (mAChR) subtypes (1,2,3), in this study we designed and synthesized a new set of ligands that integrate in the same molecular skeleton the pharmacophoric moieties of Xanomeline and of 77-LH-28-1 (1-[3-(4-butyl-1-piperidinyl)propyl]-3,4-dihydro-2(1H)-quinolinone). Xanomeline is a well-known M1/M4-preferring orthosteric agonist, which ameliorated cognitive impairments in Alzheimer’s disease patients and showed activity in various models of schizophrenia, thus being potentially beneficial for treatment of positive, negative and cognitive symptoms (4). On the other hand, 77-LH-28-1 was characterized as an M1-selective, positive allosteric modulator, thus representing an interesting pharmacological tool with cognition enhancing properties (5). As illustrated below, we planned the novel bipharmacophoric derivatives as merged structures, with the tetrahydropyridine nucleus of Xanomeline as the central core.
In the last years, different receptor sensors, based on the fluorescence resonance energy transfer (FRET), were generated for various G protein-coupled receptors, and represented a valuable tool to investigate real time receptor activation as well as ligand-receptor interactions. Recently, this analysis was performed also on a set of bitopic ligands designed for a selective interaction with M1 mAChRs (6). Our preliminary results on the group of Xanomeline/77-LH-28-1 hybrid compounds indicate, for the M1 sensor, a reproducible activation response, which depends on the linker length. Conversely, no FRET-related effect could be detected at the M2 sensor. Thus, a critical spacer length of the hybrid compounds induces conformational changes with a degree of selectively for the M1 muscarinic receptor. The synthesis and the results of pharmacological investigation will be presented and discussed.
References: 1. J. Antony, K. Kellershohn, M. Mohr-Andrä, A. Kebig, S. Prilla, M. Muth, E. Heller, T. Disingrini, C. Dallanoce et al., FASEB J 2009, 23, 442-450. 2. A. Bock, B. Chirinda, F. Krebs, R. Messerer, J. Bätz, M. Muth, C. Dallanoce et al., Nat. Chem. Biol. 2014, 10, 18-20. 3. A. Bock, M. Bermudez, F. Krebs, C. Matera, B. Chirinda, D. Sydow, C. Dallanoce et al., J. Biol. Chem. 2016, 291, 16375-16389. 4. S. Barak, I. Weiner, Int. J. Neuropsychoph. 2011, 14, 1233-1246. 5. C. J. Langmead, N. E. Austin, C. L. Branch, J. T. Brown, K. A. Buchanan, C. H. Davies, I. T. Forbes et al., Br. J. Pharmacol. 2008, 154, 1104-1115. 6. R. Messerer, M. Kauk, D. Volpato, M. C. Alonso Canizal, J. Klöckner, U. Zabel, S. Nuber, C. Hoffmann, U. Holzgrabe, ACS Chem. Biol. 2017, 12, 833-843
Libri, edizioni, biblioteche tra Cinque e Seicento: con un percorso bibliografico
No full textrec. a: M. Santoro, Libri, edizioni, biblioteche tra Cinque e Seicento: con un percorso bibliografico, Manziana, Vecchiarelli, 200
BPS algebras, genus zero and the heterotic Monster
No full textIn this note, we expand on some technical issues raised in (Paquette et al 2016 Commun. Number Theory Phys. 10 433-526) by the authors, as well as providing a friendly introduction to and summary of our previous work. We construct a set of heterotic string compactifications to 0 + 1 dimensions intimately related to the Monstrous moonshine module of Frenkel, Lepowsky, and Meurman (and orbifolds thereof). Using this model, we review our physical interpretation of the genus zero property of Monstrous moonshine. Furthermore, we show that the space of (second-quantized) BPS-states forms a module over the Monstrous Lie algebras m(g)-some of the first and most prominent examples of Generalized Kac-Moody algebras-constructed by Borcherds and Carnahan. In particular, we clarify the structure of the module present in the second-quantized string theory. We also sketch a proof of our methods in the language of vertex operator algebras, for the interested mathematician
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