Search results for "space"
showing 10 items of 21658 documents
From Caristi’s Theorem to Ekeland’s Variational Principle in ${0}_{\sigma }$ -Complete Metric-Like Spaces
2014
We discuss the extension of some fundamental results in nonlinear analysis to the setting of ${0}_{\sigma }$ -complete metric-like spaces. Then, we show that these extensions can be obtained via the corresponding results in standard metric spaces.
Fixed point results for α-implicit contractions with application to integral equations
2016
Recently, Aydi et al. [On fixed point results for α-implicit contractions in quasi-metric spaces and consequences, Nonlinear Anal. Model. Control, 21(1):40–56, 2016] proved some fixed point results involving α-implicit contractive conditions in quasi-b-metric spaces. In this paper we extend and improve these results and derive some new fixed point theorems for implicit contractions in ordered quasi-b-metric spaces. Moreover, some examples and an application to integral equations are given here to illustrate the usability of the obtained results.
Flat bands and strongly correlated Fermi systems
2019
Many strongly correlated Fermi systems including heavy-fermion (HF) metals and high-Tc superconductors belong to that class of quantum many-body systems for which Landau Fermiliquid (LFL) theory fails. Instead, these systems exhibit non-Fermi-liquid properties that arise from violation of time-reversal (T) and particle-hole (C) invariance. Measurements of tunneling conductance provide a powerful experimental tool for detecting violations of these basic symmetries inherent to LFLs, which guarantee that the measured differential conductivity dI/dV, where I is the current and V the bias voltage, is a symmetric function of V. Thus, it has been predicted that the conductivity becomes asymmetric …
Os, Sr, Nd, Pb, O isotope and trace element data from the Ferrar flood basalts, antarctica: evidence for an enriched subcontinental lithospheric sour…
1996
Os, Sr, Nd, Pb and O isotopes and trace element data are reported for basaltic andesite and andesite whole rocks and, in part, for selected mineral separates from the Jurassic Ferrar flood basalt province. Radiogenic Sr (> 0.709), unradiogenic Nd (εNd= −3 to −5), and radiogenic Pb isotopes, as well as low Nb/La ratios of 0.4 – 0.6 and Nb/La ratios between 0.45 and 0.6 are found for all rocks including our most primitive sample (Mg# = 71.9). This indicates involvement of either continental crust or enriched lithospheric mantle in magma genesis. 187Re/188Os correlates strongly with 187Os/188Os, with an age of 172 ± 5 Ma, in agreement with published Arsingle bondAr data. Initial 187Os/188Os of…
METAPHORS, HYRIDISATION AND SOCIAL SPACE
2018
Il contributo è il risultato dell'attività di ricerca condotta durante il workshop internazionale promosso dal Raffles Design Institute di Hong Kong e dall'Università di Palermo e organizzato con lo scopo di generare nuovi progetti nelle due città, evocando "nuove immagini per nuovi significati "e riconfigurando spazi e comunità. L'articolo descrive alcuni dei risultati del workshop partendo dal concetto delle metafore come giustapposizione di immagini apparentemente distanti, ma che, come risultato della stessa metafora, sono ricomposte in un'immagine diversa, carica di nuovi significati semantici. The contribution is the result of the research activity during an international workshop: th…
Source Mechanisms of Laboratory Earthquakes During Fault Nucleation and Formation
2021
Identifying deformation and pre-failure mechanisms preceding faulting is key for fault mechanics and for interpreting precursors to fault rupture. This study presents the results of a new and robust derivation of first motion polarity focal mechanism solutions (FMS) applied to acoustic emission (AE). FMS are solved using a least squares minimization of the fit between projected polarity measurements and the deviatoric stress field induced by dilatational (T-type), shearing (S-type), and compressional (C-type) sources. 4 × 10 cm cylindrical samples of Alzo Granite (AG, porosity <1%) and Darley Dale Sandstone (DDS, porosity ≈14%) underwent conventional triaxial tests in order to investigat…
Mangiar fuori. Spazi urbani e pratiche conviviali
2021
The article investigates the world of restaurants from a semiotic perspective, attempting to link the spatiality of restaurants to the convivial practices they propose.
Strategie spaziali e guerre di segni: brand della ristorazione non convenzionale
2021
Nell’ambito della ristorazione non convenzionale – da metà Novecento a oggi, e chissà per quanto ancora – è in atto una guerra di segni che mette in campo differenti concezioni dello spazio. A scorrere, e ricostruire testualmente, i principali marchi del food (fast, slow e derivati) si percepisce come questo tenace conflitto tenga in costante connessione – al modo del principio hjelmsleviano d’espansione/condensazione del discorso – i logo aziendali con l’architettura dei locali, dove i primi alludono ai secondi e, viceversa, i secondi danno fisicamente riscontro alla topologia che i primi incessantemente mettono in opera. Se, come sappiamo, l’uomo è ciò che mangia, lo è perché pasteggia se…
ITS1 region of the nuclear ribosomal DNA of the mycoparasite Pythium periplocum, its taxonomy, and its comparison with related species.
2000
Pythium periplocum Drechsler was isolated from some soil samples taken in the botanical garden of Tenerife, Canary Islands. This fungus has been found to be an aggressive mycoparasite of Botrytis cinerea. It is unique amongst the members of the genus Pythium because of the character combination of inflated filamentous type of sporangia and ornamented oogonia. The taxonomic description of this fungus and its comparison with related species, together with the polymerase chain reaction of the internal transcribed spacer of its nuclear ribosomal DNA, are discussed in this article.
Phylogeny, biogeography and evolution of Triglochin L. (Juncaginaceae) – Morphological diversification is linked to habitat shifts rather than to gen…
2015
A species-level phylogeny is presented for Triglochin, the largest genus of Juncaginaceae (Alismatales) comprising about 30 species of annual and perennial herbs. Triglochin has an almost cosmopolitan distribution with Australia as centre of species diversity. Trans-Atlantic and trans-African disjunctions exist in the genus. Phylogenetic analyses were conducted based on molecular data obtained from nuclear (ITS, internal transcribed spacer) and chloroplast sequence data (psbA-trnH spacer, matK gene). Based on the phylogeny of the group divergence times were estimated and ancestral distribution areas reconstructed. Our data confirm the monophyly of Triglochin and resolve relationships betwee…