136 research outputs found
Potentiostatic infrared titration of 11-Mercaptoundecanoic acid monolayers
Acknowledgment This work was supported by the Spanish DGICYT under grant CTQ2008-00371 and by the Junta de Andalucía under grant P07-FQM-02492.Peer reviewedPostprin
Non-covalent interactions at electrochemical interfaces : one model fits all?
Acknowledgements Funding from the DGI (Spanish Ministry of Education and Science) through Project CTQ2009-07017 is gratefully acknowledged. E.P.M.L. wishes to thank the Universidad Nacional de Co´rdoba, Argentina, for a grant within the ‘‘Programa de Movilidad Internacional de Profesores Cuarto Centenario’’.Peer reviewedPublisher PD
Importance of Acid–Base Equilibrium in Electrocatalytic Oxidation of Formic Acid on Platinum
This work was supported by Japanese Society for the Promotion of Science (JSPS) KAKENHI Grants Nos. 24550143 and 24750117 and MEXT Project of Integrated Research on Chemical Synthesis. M.T.M.K. gratefully acknowledges the award of Long-Term Fellowship of JSPS (No. L-11527) and Visiting Professorship of Hokkaido University. T.U. acknowledges Grants-in-Aid for Regional R&D Proposal-Based Program from Northern Advancement Center for Science & Technology of Hokkaido, Japan. J.J. acknowledges scholarship of Asian Graduate School, Hokkaido University.Peer reviewedPostprin
Cognitive resource allocation determines the organization of personal networks
[Póster presentado a]: XXII Congreso de Física Estadística (FisEs'18), Madrid, 18-20 de octubre de 2018.The typical human personal social network contains about 150 relationships including kin, friends, and acquaintances, organized into a set of hierarchically inclusive layers of increasing size but decreasing emotional intensity. Data from a number of different sources reveal that these inclusive layers exhibit a constant scaling ratio of ∼3. While the overall size of the networks has been connected to our cognitive capacity, no mechanism explaining why the networks present a layered structure with a consistent scaling has been proposed. Here we show that the existence of a heterogeneous cost to relationships (in terms of time or cognitive investment), together with a limitation in the total capacity an individual has to invest in them, can naturally explain the existence of layers and, when the cost function is linear, explain the scaling between them. We develop a one-parameter Bayesian model that fits the empirical data remarkably well. In addition, the model predicts the existence of a contrasting regime in the case of small communities, such that the layers have an inverted structure (increasing size with increasing emotional intensity). We test the model with five communities and provide clear evidence of the existence of the two predicted regimes. Our model explains, based on first principles, the emergence of structure in the organization of personal networks and allows us to predict a rare phenomenon whose existence we confirm empirically
Cognitive resource allocation determines the organization of personal networks
The typical human personal social network contains about 150 relationships including kin, friends, and acquaintances, organized into a set of hierarchically inclusive layers of increasing size but decreasing emotional intensity. Data from a number of different sources reveal that these inclusive layers exhibit a constant scaling ratio of 3. While the overall size of the networks has been connected to our cognitive capacity, no mechanism explaining why the networks present a layered structure with a consistent scaling has been proposed. Here we show that the existence of a heterogeneous cost to relationships (in terms of time or cognitive investment), together with a limitation in the total capacity an individual has to invest in them, can naturally explain the existence of layers and, when the cost function is linear, explain the scaling between them. We develop a one-parameter Bayesian model that fits the empirical data remarkably well. In addition, the model predicts the existence of a contrasting regime in the case of small communities, such that the layers have an inverted structure (increasing size with increasing emotional intensity). We test the model with five communities and provide clear evidence of the existence of the two predicted regimes. Our model explains, based on first principles, the emergence of structure in the organization of personal networks and allows us to predict a rare phenomenon whose existence we confirm empirically.I.T., J.A.C., and A.S. were supported in part by Fundación Banco Bilbao Vizcaya Argentaria through Grant Los Números de Dunbar y la Estructura de las Sociedades Digitales: Modelización y Simulación; by Ministerio de Economía, Innovación y Competitividad (Spain) through Grants FIS2015-64349-P VARIANCE (Ministerio
de Economía y Empresa/Fondo Europeo de Desarrollo Regional, Unión Europea);
and by the European Commission through FET Open Research and
Innovation Action 662725 Bridging the Gap: From Individual Behaviour to
the Socio-Technical Man and FET Proactive RIA 640772 Distributed Global
Financial Systems for Society. R.I.M.D. was supported by the European
Research Council Advanced Investigator through Grant 295663
Super-Nernstian Shifts of Interfacial Proton-Coupled Electron Transfers : Origin and Effect of Noncovalent Interactions
The support of the University of Aberdeen is gratefully acknowledged. C.W. acknowledges a summer studentship from the Carnegie Trust for the Universities of Scotland. E.P.M.L. acknowledges SeCYT (Universidad Nacional de Cordoba), ́ CONICET- PIP 11220110100992, Program BID (PICT 2012-2324), and PME 2006-01581 for financial support.Peer reviewedPostprin
A theorem on the absence of phase transitions in one-dimensional growth models with onsite periodic potentials
We rigorously prove that a wide class of one-dimensional growth models with
onsite periodic potential, such as the discrete sine-Gordon model, have no
phase transition at any temperature . The proof relies on the spectral
analysis of the transfer operator associated to the models. We show that this
operator is Hilbert-Schmidt and that its maximum eigenvalue is an analytic
function of temperature.Comment: 6 pages, no figures, submitted to J Phys A: Math Ge
Stability of the personal relationship networks in a longitudinal study of middle school students
The personal network of relationships is structured in circles of
friendships, that go from the most intense relationships to the least intense
ones. While this is a well established result, little is known about the
stability of those circles and their evolution in time. To shed light on this
issue, we study the temporal evolution of friendships among teenagers during
two consecutive academic years by means of a survey administered on five
occasions. We show that the first two circles, best friends and friends, can be
clearly observed in the survey but also that being in one or the other leads to
more or less stable relationships. We find that being in the same class is one
of the key drivers of friendship evolution. We also observe an almost constant
degree of reciprocity in the relationships, around 60%, a percentage influenced
both by being in the same class and by gender homophily. Not only do our
results confirm the mounting evidence supporting the circle structure of human
social networks, but they also show that these structures persist in time
despite the turnover of individual relationships -- a fact that may prove
particularly useful for understanding the social environment in middle schools.Comment: 10 pages, 7 figures, requires wlscirep.cls, jabbrv.sty,
jabbrv-ltwa-all.ldf, and jabbrv-ltwa-en.ldf (included
Phase Transitions in Two-Dimensional Traffic Flow Models
We introduce two simple two-dimensional lattice models to study traffic flow
in cities. We have found that a few basic elements give rise to the
characteristic phase diagram of a first-order phase transition from a freely
moving phase to a jammed state, with a critical point. The jammed phase
presents new transitions corresponding to structural transformations of the
jam. We discuss their relevance in the infinite size limit.Comment: RevTeX 3.0 file. Figures available upon request to e-address
[email protected] (or 'dopico' or 'molera' or 'anxo', same node
- …