Search results for "Expo"

Poincaré inequalities and Steiner symmetrization

1996

A complete geometric characterization for a general Steiner symmetric domain Ω ⊂ Rn to satisfy the Poincare inequality with exponent p > n−1 is obtained and it is shown that this range of exponents is best possible. In the case where the Steiner symmetric domain is determined by revolving the graph of a Lipschitz continuous function, it is shown that the preceding characterization works for all p > 1 and furthermore for such domains a geometric characterization for a more general Sobolev–Poincare inequality to hold is given. Although the operation of Steiner symmetrization need not always preserve a Poincare inequality, a general class of domains is given for which Poincare inequalities are…

Floquet theory: exponential perturbative treatment

2001

We develop a Magnus expansion well suited for Floquet theory of linear ordinary differential equations with periodic coefficients. We build up a recursive scheme to obtain the terms in the new expansion and give an explicit sufficient condition for its convergence. The method and formulae are applied to an illustrative example from quantum mechanics.

Flow resistance in gravel-bed channels with large-scale roughness

2003

A previously published mixing length (ML) model for evaluating the Darcy–Weisbach friction factor for a large-scale roughness condition (depth to sediment height ratio ranging from 1 to 4) is briefly reviewed and modified (MML). Then the MML model and a modified drag (MD) model are experimentally tested using laboratory measurements carried out for gravel-bed channels and large-scale roughness condition. This analysis showed that the MML gives accurate estimates of the Darcy–Weisbach coefficient and for Froude number values greater than 0·5 the MML model coincides with the ML one. Testing of the MD model shows limited accuracy in estimating flow resistance. Finally, the MML and MD models are com…

Cracking behavior of zeolites with connected 12- and 10-member ring channels: The influence of pore structure on product distribution

1997

n-Heptane has been cracked on a CIT-1 zeolite which has connected 12- and 10-member ring (MR) channels, and its behavior was compared with that of MCM-22 with nonconnected 12- and 10-MR channels, and SSZ-24 and BETA with unidirectional and tridirectional 12-MR channels, respectively. The kinetic rate constant is highest for CIT-1, and the decay constant is lowest. From the selectivity point of view, its behavior can be better represented by a system with large cavities (the intersections between the 12- and 10-MR) connected by windows. This gives a behavior typical of that of large pore zeolites. CIT-1 produces a remarkably high selectivity toi-C4, and specially to isobutane. This zeolite s…

Medical Research and Innovation

2021

This volume is dedicated to multidisciplinary research at the interface between basic biomedicine and clinical practice. This book guides best practice in the diagnosis and therapy while dealing with difficult-to-treat disorders of yet unclear etiology. Chapters address such disorders as granulomatosis with polyangiitis causing autoimmune-related multiorgan inflammation of blood vessels, increasingly widespread allergy to peanuts, occupational exposure to zinc oxide, and immunogenic responses to pneumococcal and influenza vaccination underlying their preventive effectiveness. Other hot issues deal with the proper use of fluid therapy in the perioperative period and a cognitive decline in lu…

Perfluorinated Compounds in Food: A Global Perspective

2011

Perfluorinated compounds (PFCs) are resistant to breakdown and are turning up in unexpected places around the world, becoming emerging food contaminants. Although these chemicals have been used in countless products since the 1950s, they have been subject to little control until now. There is still an insufficient knowledge of their sources, occurrence, and hazards for food safety decision making. This article provides a comprehensive review of the food contamination levels and dietary intake risks posed by PFCs, as well as the specific methods developed for their determination. It is based on the evaluation of the published literature between 2004 and the beginning of 2010, with special em…

Mechanisms of protein expression in the rat optic nerve: Modifications by alcohol exposure

2005

espanolObjetivos: Nuestros trabajos previos han demostrado que el consumo abusivo de etanol durante la gestacion induce retraso en el desarrollo y alteraciones estructurales en los ojos y en la vision (Pinazo-Duran et al., Teratology ’93; Eur J Ophthalmol ’97; Stromland and Pinazo-Duran, Teratology ’94; Alcohol Alcoholism ’02). Nos proponemos estudiar a un nivel celular y molecular si el etanol modifica la expresion de proteinas marcadoras del desarrollo glial durante los estadios pre- y postnatal de la rata, que puedan contribuir a la dismorfogenesis del nervio optico. Metodo: Para estudiar las acciones del etanol sobre el desarrollo del nervio optico de ratas sometidas a un proceso de alc…

Fixation des honoraires d'avocat en l'absence de convention

2013

International audience

Zvaigžņotā Debess: 2012, Rudens (217)

2012

Saturs: P.Stučkas LVU ieguldījums astronomijas speciālistu sagatavošanā ; Starp "maldugunīm" un zvaigznēm ; A.Alksnis. Dawn kosmosa misija palīdz atklāt asteroīda Vesta noslēpumus ; D.Docenko. Komentārs: Par Higsa bozona atklāšanu ; I.P. Frīdriha Candera 125.dzimšanas dienai Krievijas Pasts izdevis marku ; P.Leckis. Mākoņu pārklātais pavadonis ; D.Kotlere, I.Šmelds. Kosmisko atlūzu novērojumi Ventspils Starptautiskajā radioastronomijas centrā ; Pirmo reizi “ZvD”: Dace Kotlere ; I.P. Divas dienas, godinot Jāni Ikaunieku (28.IV 1912.–27.IV 1969.) ; I.Pundure. Jāņa Ikaunieka devums Latvijas astronomijai ; N.Cimahoviča, Imants Vilks, R.Saveļjeva, T.Millers, A.Krastiņš. Atmiņas par Ikaunieku ; E…

José Vidal-Beneyto entrevista a Consuelo Ciscar: "Hoy más que nunca lo local es universal"

2004