149 research outputs found
Pairing and alpha-like quartet condensation in N=Z nuclei
We discuss the treatment of isovector pairing by an alpha-like quartet
condensate which conserves exactly the particle number, the spin and the
isospin. The results show that the quartet condensate describes accurately the
isovector pairing correlations in the ground state of systems with an equal
number of protons and neutronsComment: 4 pages, to appear in Journal of Physics: Conference Serie
“Now everyone knows I’m a serial killer” Spontaneous Intentionality in Conversational Metaphor and Story-Telling
Drawing on data from a series of informal conversations about public safety and police-community relations, we distinguish between a speaker’s generalized communicative intentions with respect to metaphor use and story-telling, based on what Chafe (1994, p. 145) calls “unifying ideas that persist in semiactive consciousness” and the spontaneous intentions that arise within the short-term focus or spotlight of consciousness and guide the production of actual utterances. Although speakers occasionally enter a conversation with a fixed intention to express an idea with a particular metaphor, tell a particular story in a particular style, or accomplish some other speech act, such as persuading or informing, more commonly in ordinary conversations speakers begin with only a generalized intention to engage in the social interaction, sometimes but not always accompanied by generalized intentions regarding a particular topic or a particular form of expression. We argue that these “unifying ideas” interact with the contents of the short-term focus or spotlight of consciousness to generate spontaneous communicative intentions that in turn guide the production of metaphors, stories, and other language segments. Often these spontaneous communicative intentions arise interactively in response to other participants’ utterances; sometimes they arise in response to unforeseen opportunities in the speaker’s own utterances. Consequently, in ordinary casual conversations the spontaneous communicative intentions behind metaphor, story-telling and humor are often formed ‘on the fly,’ in response to the dynamic social interaction, and sometimes as a result of collaboration with other participants
Progress and perspective on different strategies to achieve wake-up-free ferroelectric hafnia and zirconia-based thin films
In the last decade orthorhombic hafnia and zirconia films have attracted tremendous attention arising from the discovery of ferroelectricity at the nanoscale. However, an initial wake-up pre-cycling is usually needed to achieve a ferroelectric behaviour in these films. Recently, different strategies, such as microstructure tailoring, defect, bulk and interface engineering, doping, NH3 plasma treatment and epitaxial growth, have been employed to obtain wake-up free orthorhombic ferroelectric hafnia and zirconia films. In this work we review recent developments in obtaining polar hafnia and zirconia-based thin films without the need of any wake-up cycling. In particular, we discuss the rhombohedral phase of hafnia/ zirconia, which under a constrained environment exhibits wake-up-free ferroelectric behaviour. This phase could have a strong impact on the current investigations of ferroelectric binary oxide materials and pave the way toward exploiting ferroelectric behaviour for next-generation memory and logic gate applications.This work was supported by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding Contract UIDB/04650/2020 and by DST-SERB, Govt. of India through Grant Nr. ECR/2017/00006. R. F. Negrea and L. Pintilie acknowledge funding through project CEPROFER/ PN-III-P4-ID-PCCF-2016-0047 (contract 16/2018, funded by UEFISCDI). J.L.M-D. thanks the Royal Academy of Engineering Chair in Emerging Technologies Grant, CIET1819_24, the EPSRC grant EP/T012218/1- ECCS – EPSRC, and the grant EU-H2020-ERC-ADG # 882929, EROS
Progress and perspective on different strategies to achieve wake-up-free ferroelectric hafnia and zirconia-based thin films
In the last decade orthorhombic hafnia and zirconia films have attracted tremendous attention arising from the discovery of ferroelectricity at the nanoscale. However, an initial wake-up pre-cycling is usually needed to achieve a ferroelectric behaviour in these films. Recently, different strategies, such as microstructure tailoring, defect, bulk and interface engineering, doping, NH3 plasma treatment and epitaxial growth, have been employed to obtain wake-up free orthorhombic ferroelectric hafnia and zirconia films. In this work we review recent developments in obtaining polar hafnia and zirconia-based thin films without the need of any wake-up cycling. In particular, we discuss the rhombohedral phase of hafnia/ zirconia, which under a constrained environment exhibits wake-up-free ferroelectric behaviour. This phase could have a strong impact on the current investigations of ferroelectric binary oxide materials and pave the way toward exploiting ferroelectric behaviour for next-generation memory and logic gate applications.This work was supported by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding Contract UIDB/04650/2020 and by DST-SERB, Govt. of India through Grant Nr. ECR/2017/00006. R. F. Negrea and L. Pintilie acknowledge funding through project CEPROFER/ PN-III-P4-ID-PCCF-2016-0047 (contract 16/2018, funded by UEFISCDI). J.L.M-D. thanks the Royal Academy of Engineering Chair in Emerging Technologies Grant, CIET1819_24, the EPSRC grant EP/T012218/1- ECCS – EPSRC, and the grant EU-H2020-ERC-ADG # 882929, EROS
Ferroelectricity modulates polaronic coupling at multiferroic interfaces
Physics of the multiferroic interfaces is currently understood mostly within a phenomenological framework based on screening of the polarization field and depolarizing charges. Additional effects still unexplored are the band dependence of the interfacial charge modulation and the associated changes of the electron-phonon interaction, coupling the charge and lattice degrees of freedom. Here, multiferroic heterostructures of the colossal-magnetoresistance manganite La1-xSrxMnO3 buried under ferroelectric BaTiO3 and PbZrxTi1-xO3 are investigated using soft-X-ray angle-resolved photoemission. The experimental band dispersions from the buried La1-xSrxMnO3 identify coexisting two-dimensional hole and three-dimensional electron charge carriers. The ferroelectric polarization modulates their charge density, affecting the coupling of the 2D holes and 3D electrons with the lattice which forms large Fröhlich polarons inherently reducing mobility of the charge carriers. Our k-resolved results on the orbital occupancy, band filling and electron-lattice interaction in multiferroic oxide heterostructures modulated by the ferroelectric polarization disclose most fundamental physics of these systems needed for further progress of beyond-CMOS ferro-functional electronics
Opinionated texts in social media: A proposal for evaluative judgement methodology
The paper reports on a pilot study devoted to the analysis of opinions expressed by Facebook discussants related to the immigration crisis in Europe. Opinions were conceptualised as the subjective expression of evaluation. The data were investigated in line with an original, tripartite typology consisting of 46 criteria of evaluative language coming from distinct scholarly traditions: media studies, linguistics and Critical Discourse Analysis. Generally speaking, the proposed templates proved effective when mapped onto social media data; however, as there is a partial overlap of some of the categories used in the pilot study, the number of categories needs to be reduced in the subsequent investigation. The secondary objective of this paper is to present computational tools employed in the study, which, as the study shows, can enrich research methodology in communication studies, and these comprise the “R” package used for data visualisation and lexical and sentence-based embeddings based on LLM.Niniejszy artykuł stanowi raport z badania pilotażowego poświęconego analizie opinii wyrażanych przez dyskutantów na Facebooku na temat kryzysu imigracyjnego w Europie. Opinie rozumiane są w tym badaniu jako subiektywne wyrażanie oceny. Dane zostały przeanalizowane według zaproponowanej trójczłonowej typologii składającą się z 46 kryteriów języka oceniającego. Kryteria te pochodzą z różnych tradycji naukowych: medioznawstwa, językoznawstwa i krytycznej analizy dyskursu. Zaproponowane szablony okazały się skuteczne w odniesieniu do danych z mediów społecznościowych; jednakże, ze względu na częściowe nakładanie się niektórych kategorii użytych w badaniu pilotażowym, w dalszych badaniach liczba kategorii musi zostać zmniejszona. Drugim celem tego artykułu jest przedstawienie narzędzi komputerowych użytych w niniejszej analizie. Jak wskazuje zaprezentowana analiza narzędzia te mogą wzbogacić metodologię badań w dziedzinie komunikacji. Zastosowane narzędzia to pakiet „R” używany do wizualizacji danych, biblioteki Python oraz osadzenia (embeddings) leksykalne i zdaniowe oparte na LLM.info:eu-repo/semantics/publishedVersio
Start spreading the news: A comparative experiment on the effects of populist communication on political engagement in sixteen European countries
Pulsed reverse electrochemical synthesis of Ag-TiO2 composites from deep eutectic solvents: Photocatalytic and antibacterial behaviour
Data availability:
No data was used for the research described in the article.Supplementary materials are available online at: https://www.sciencedirect.com/science/article/pii/S2666523925000571#sec0015 .This study presents an environmentally friendly approach for synthesis Ag-TiO2 composite using pulsed reverse current (PRC) electrodeposition from green electrolytes, specifically deep eutectic solvents (DESs). The combination of PRC and DESs offers better control over nanoparticle synthesis while eliminating the need for toxic or expensive precursors, representing a significant advancement in sustainable nanomaterial synthesis. Different electrochemical parameters were adjusted, and their influence on the structure and morphology of the composite was investigated using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). TEM analysis revealed that silver nanoparticles (Ag NPs) are attached to TiO2 nanopowder, with the coexistence of TiO2 and Ag further confirmed by XRD and XPS. The recorded UV–Vis diffuse reflectance spectra (DRS) displayed a broad peak in the range of 400 – 650 nm, associated with the localized surface plasmon resonance (LSPR) of Ag NPs on the semiconductor’s surface. The photocatalytic activity of TiO2 nanopowder and Ag-TiO2 composite was evaluated based on the degradation of methyl orange (MO) dye under UV and visible light illumination. Our findings clearly demonstrated that the incorporation of Ag improved the photocatalytic efficiency. The mechanism of MO dye degradation was explored by using various scavengers, revealing that superoxide radicals (•O−
2 ) play a dominant role. Furthermore, the incorporation of Ag NPs significantly enhanced the antimicrobial activity of the oxide against both Gram-positive (B. subtilis) and Gram-negative (E.coli) strains.The present work was supported by the Romanian National Grant GNAC ARUT 2023 project (No. 7/06.10.2023), NANO_NP_DES, entitled "Electrochemical synthesis of hybrid nanoparticles Ag/TiO2 and Ag/Fe3O4 with biomedical applications". Also, the work was supported by the IMT Core Program µNanoEl, within the PNCDI 2022-2026, carried out with the support of Romanian Ministry of Research, Innovation and Digitization, project No. 23070201.
N.D. acknowledges the support by the contract PN 23 21 01 06 sponsored by the Romanian Ministry of Research, Innovation, and Digitization.
Additionally, National and European funds financially supported the work through FCT under Research Grant UIDB/00081/2020 (https://doi.org/10.54499/UIDB/00081/2020)- CIQUP, LA/P/0056/2020 (https://doi.org/10.54499/LA/P/0056/2020) – IMS
Accurate Prediction of Secreted Substrates and Identification of a Conserved Putative Secretion Signal for Type III Secretion Systems
The type III secretion system is an essential component for virulence in many Gram-negative bacteria. Though components of the secretion system apparatus are conserved, its substrates—effector proteins—are not. We have used a novel computational approach to confidently identify new secreted effectors by integrating protein sequence-based features, including evolutionary measures such as the pattern of homologs in a range of other organisms, G+C content, amino acid composition, and the N-terminal 30 residues of the protein sequence. The method was trained on known effectors from the plant pathogen Pseudomonas syringae and validated on a set of effectors from the animal pathogen Salmonella enterica serovar Typhimurium (S. Typhimurium) after eliminating effectors with detectable sequence similarity. We show that this approach can predict known secreted effectors with high specificity and sensitivity. Furthermore, by considering a large set of effectors from multiple organisms, we computationally identify a common putative secretion signal in the N-terminal 20 residues of secreted effectors. This signal can be used to discriminate 46 out of 68 total known effectors from both organisms, suggesting that it is a real, shared signal applicable to many type III secreted effectors. We use the method to make novel predictions of secreted effectors in S. Typhimurium, some of which have been experimentally validated. We also apply the method to predict secreted effectors in the genetically intractable human pathogen Chlamydia trachomatis, identifying the majority of known secreted proteins in addition to providing a number of novel predictions. This approach provides a new way to identify secreted effectors in a broad range of pathogenic bacteria for further experimental characterization and provides insight into the nature of the type III secretion signal
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