Search results for " 25"
showing 10 items of 220 documents
Prescribing the behaviour of geodesics in negative curvature
2010
Given a family of (almost) disjoint strictly convex subsets of a complete negatively curved Riemannian manifold M, such as balls, horoballs, tubular neighborhoods of totally geodesic submanifolds, etc, the aim of this paper is to construct geodesic rays or lines in M which have exactly once an exactly prescribed (big enough) penetration in one of them, and otherwise avoid (or do not enter too much in) them. Several applications are given, including a definite improvement of the unclouding problem of [PP1], the prescription of heights of geodesic lines in a finite volume such M, or of spiraling times around a closed geodesic in a closed such M. We also prove that the Hall ray phenomenon desc…
La celebración del protocolo al tratado Antártico sobre protección del medio ambiente: Orígenes y negociaciones
1993
En el presente trabajo se analiza la historia de la celebración del Protocolo de Madrid al Tratado Antártico sobre protección del medio ambiente. Tras exponer los diversos intereses en presencia que llevaron a la decisión de negociar este Protocolo al Tratado Antártico, el examen se centra en cómo se consiguieron alcanzar acuerdos tan intensos en materias tan esquivas, como las que afectan a la protección del medio ambiente antártico.
La Méthode como hermenéutica musical Homenaje a Edgar Morin por su 100º cumpleaños
2021
The present work addresses the principles and properties of the complex thought formulated by the French thinker Edgar Morin and the way in which he was able me to articulate his conception of organizational complexity with one of the most important theories of musical analysis, which emerged at the beginning of the 20th century: the schenkerian analysis. It is a review and extension of a few pages of my doctoral thesis, which are intended to pay tribute to who has been, in addition to my teacher, Honorary President of Itamar since its first issue. His teachings and support has always been the engine for my quest for musical organization. On July 21, 2021, Morin celebrated his 100th birthda…
Polyamide/carbonaceous particles nanocomposites fibers: Morphology and performances
2015
In this work, the influence of carbonaceous particles with different sizes and shapes on the morphology and mechanical performances of polyamide (PA)-based fibers was investigated. Graphene nanoplatelets (GNP) are compared with spherical and rod-like carbon fillers such as carbon black (CB) and multiwall carbon nanotubes (CNTs). The increments of the complex viscosity as well as elastic and loss moduli, in the melt state, assessed by rheological analysis, are reduced by modifying polyamide (PA) matrix with nanofillers in a following order: CNTs > GNP > CB. All the nanocomposites, however, show viscosity and moduli higher than those of neat PA. The CB loading causes a mere increase of the vi…
On the role of multi-functional polyhedral oligomeric silsesquioxane in polystyrene-zinc oxide nanocomposites
2014
Abstract Multi-functional trisilanol phenyl (TSPH) and trisilanol isobutyl (TSIB) polyhedral oligomeric silsesquioxane (POSS) have been used in the formulation of advanced polystyrene (PS)-zinc oxide (ZnO) nanocomposites. The neat matrix and PS/ZnO-based nanocomposites have been characterized through rheological, morphological, mechanical, and dynamic thermo-mechanical analysis. Both TSPH and TSIB are able to improve the dispersion of ZnO into the polystyrene matrix; furthermore, adding TSIB leads to better results because it facilitates better solubility into the PS matrix and interaction/reaction with the ZnO nanopowder. Finally, the optical properties and photo-oxidative resistance of th…
Zvaigžņotā Debess: 2018, Vasara (240)
2018
Jauna hipotēze par I tipa pārnovu izcelšanos ; No 108 minūtēm līdz 96 dienām ; Maiņzvaigznes (astronomija skolā) ; O.Dumbrājs. Nēteres teorēmai 100 gadu ; K.Švarcs. Jauni novērojumi tālā un tuvā kvazārā ; I.P. Īsumā: ALMA un VLT iegūst liecību par zvaigžņu veidošanos tikai 250 miljonus gadu pēc Lielā Sprādziena ; I.Pundure. Lagūnas miglājs – zvaigžņu bērnistaba Habla skatījumā ; I.Pundure. ALMA un APEX atklāj veidojošos galaktiku megasaplūšanu agrīnajā Visumā ; K.Salmiņš. LU Astronomijas institūts pirmais veicis nanopavadoņa S-NET lāzermērījumus ; J.Jaunbergs. Zeme atpakaļskata spogulī ; J.Jaunbergs. Sniegotā Helēne un mazais Polideiks ; R.Misa. Latvijas uzņēmums Eventech piedalīsies Luna-2…
Prompt Photon Identification in the ALICE Experiment: The Isolation Cut Method
2007
Submitted for publication in NIM; The ALICE experiment at LHC will detect and identify prompt photons and light neutral mesons with the PHOS and EMCal detectors. Charged particles will be detected and identified by the central tracking system. In this paper, a method to identify prompt photons and to separate them from the background of hadrons and decay photons in PHOS with the help of isolation cuts is presented.
Identification of photon-tagged jets in the ALICE experiment
2007
30 pp.-- PACS numbers: 25.75.Nq, 24.10.Lx, 25.75.-q, 29.40.Vj.-- Published in: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. Volume 585, Issues 1-2, 21 January 2008, Pages 28-39.-- Final full-text version of the paper available at: http://dx.doi.org/10.1016/j.nima.2007.10.050.
Spectroscopy of 253No and its daughters
2011
Abstract New high-statistics data have been obtained on the decay properties of 253 No and its daughters using the reaction 207 Pb( 48 Ca, 2n) 253 No. This was made possible thanks to an improved transmission of fusion–evaporation residues through the VASSILISSA recoil separator and an increased efficiency of the GABRIELA detector setup. The decay schemes of 253 No and 249 Fm have been revisited. The known level scheme of 249 Fm has been confirmed, including a new level at 669 keV excitation energy. The observation of L X-rays in coincidence with the α decay of 249 Fm gives additional support to the ground-state configuration of 1 / 2 + [ 631 ] instead of 5 / 2 + [ 622 ] for 245 Cf. In both…
The electronion scattering experiment ELISe at the International Facility for Antiproton and Ion Research (FAIR) - A conceptual design study
2011
The electronion scattering experiment ELISe is part of the installations envisaged at the new experimental storage ring at the International Facility for Antiproton and Ion Research (FAIR) in Darmstadt, Germany. It offers an unique opportunity to use electrons as probe in investigations of the structure of exotic nuclei. The conceptual design and the scientific challenges of ELISe are presented. © 2011 Elsevier B.V. All rights reserved.