New developments for a chiral effective theory of nuclear matter

2011 ◽  
Author(s):  
J. A. Oller ◽  
A. Lacour ◽  
U.-G. Meißner
2012 ◽  
Vol 18 ◽  
pp. 182-190 ◽  
Author(s):  
CÉSAR A. Z. VASCONCELLOS ◽  
JORGE HORVATH ◽  
DIMITER HADJIMICHEF ◽  
ROSANA O. GOMES

Nuclear science has developed many excellent descriptions that embody various properties of the nucleus, and nuclear matter at low, medium and high densities. However, a full microscopic understanding of nuclear systems is still lacking. The aim of our theoretical research group is to shed some light on such challenges and particularly on open questions facing the high density nuclear many-body problem. Here we focus our attention on the conceptual issue of naturalness and its role in shaping the baryon-meson phase space dynamics in the description of the equation of state (EoS) of nuclear matter. In particular, in order to stimulate possible new directions of research, we discuss relevant aspects of a recently developed relativistic effective theory for nuclear matter with natural parametric couplings and genuine many-body forces. Among other topics we discuss in this work the connection of this theory with other known effective QHD models of the literature and its potentiality in describing a new physics for dense matter.


2004 ◽  
Vol 13 (07) ◽  
pp. 1223-1228
Author(s):  
CLÁUDIO M. MAEKAWA ◽  
MOISÉS RAZEIRA ◽  
EDUARDO F. LÜTZ ◽  
CÉSAR A. Z. VASCONCELLOS ◽  
MANFRED DILLIG

In the investigation of the role of naturalness in effective theory, we focus on dense hadronic matter in a generalized relativistic multi-baryon Lagrangian density mean field approach which contains nonlinear self-couplings of the σ and δ meson fields interacting with the fundamental baryon octet and with the ω and ϱ meson fields and compare its predictions with estimates obtained within a phenomenological naive dimensional analysis based on the naturalness of the coupling constants of the Lagrangian model; our investigation is limited however to the scalar sector of the theory. Upon adjusting the model parameters to describe bulk static properties of ordinary nuclear matter, we show that our approach represents a natural modelling of nuclear matter under the extreme conditions of density as found in the interior of neutron stars.


Author(s):  
P.A. Crozier ◽  
M. Pan

Heterogeneous catalysts can be of varying complexity ranging from single or double phase systems to complicated mixtures of metals and oxides with additives to help promote chemical reactions, extend the life of the catalysts, prevent poisoning etc. Although catalysis occurs on the surface of most systems, detailed descriptions of the microstructure and chemistry of catalysts can be helpful for developing an understanding of the mechanism by which a catalyst facilitates a reaction. Recent years have seen continued development and improvement of various TEM, STEM and AEM techniques for yielding information on the structure and chemistry of catalysts on the nanometer scale. Here we review some quantitative approaches to catalyst characterization that have resulted from new developments in instrumentation.HREM has been used to examine structural features of catalysts often by employing profile imaging techniques to study atomic details on the surface. Digital recording techniques employing slow-scan CCD cameras have facilitated the use of low-dose imaging in zeolite structure analysis and electron crystallography. Fig. la shows a low-dose image from SSZ-33 zeolite revealing the presence of a stacking fault.


2013 ◽  
Vol 23 (2) ◽  
pp. 49-61 ◽  
Author(s):  
Jamie Perry ◽  
Graham Schenck

Despite advances in surgical management, it is estimated that 20–30% of children with repaired cleft palate will continue to have hypernasal speech and require a second surgery to create normal velopharyngeal function (Bricknell, McFadden, & Curran, 2002; Härtel, Karsten, & Gundlach, 1994; McWilliams, 1990). A qualitative perceptual assessment by a speech-language pathologist is considered the most important step of the evaluation for children with resonance disorders (Peterson-Falzone, Hardin-Jones, & Karnell, 2010). Direct and indirect instrumental analyses should be used to confirm or validate the perceptual evaluation of an experienced speech-language pathologist (Paal, Reulbach, Strobel-Schwarthoff, Nkenke, & Schuster, 2005). The purpose of this article is to provide an overview of current instrumental assessment methods used in cleft palate care. Both direct and indirect instrumental procedures will be reviewed with descriptions of the advantages and disadvantages of each. Lastly, new developments for evaluating velopharyngeal structures and function will be provided.


2002 ◽  
Vol 59 (11) ◽  
pp. 571-576 ◽  
Author(s):  
Gratwohl

Die Transplantation hämatopoietischer Stammzellen umfasst heute Stammzellen aus Knochenmark, peripherem Blut oder Nabelschnurblut. Leukämien, Lymphoproliferative Erkrankungen, aplastische Anämie und schwere angeborene Erkrankungen des Knochenmarkes sind Hauptindikationen für allogene, lymphoproliferative Erkrankungen, Leukämien, solide Tumoren und schwere Autoimmunkrankheiten Hauptindikationen für autologe Transplantationen. Neue Verfahren wie reduzierte Konditionierung und selektive Gabe von Spenderlymphozyten eröffnen die Stammzelltransplantation auch für ältere Patienten und für solche mit vorbestehender Komorbidität. Wenn immer möglich, wird die Transplantation ab Diagnose in den Behandlungsplan integriert. Die Wahl des Verfahrens und des geeigneten Zeitpunktes wird nach individuellem Risikoprofil erstellt. Alter oder Diagnose sind nicht mehr alleinige Entscheidungskriterien. Als etablierte Therapieform dürfte die hämatopoietische Stammzelltransplantation als Modell dienen für Stammzelltransplantationen auch anderer Organe.


Author(s):  
Peter Vorderer

This paper points to new developments in the context of entertainment theory. Starting from a background of well-established theories that have been proposed and elaborated mainly by Zillmann and his collaborators since the 1980s, a new two-factor model of entertainment is introduced. This model encompasses “enjoyment” and “appreciation” as two independent factors. In addition, several open questions regarding cultural differences in humans’ responses to entertainment products or the usefulness of various theoretical concepts like “presence,” “identification,” or “transportation” are also discussed. Finally, the question of why media users are seeking entertainment is brought to the forefront, and a possibly relevant need such as the “search for meaningfulness” is mentioned as a possible major candidate for such an explanation.


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