Analyzing library collections with starfield visualizations

This paper presents a qualitative and formative study of the uses of a starfield-based visualization interface for analysis of library collections. The evaluation process has produced feedback that suggests ways to significantly improve starfield interfaces and the interaction process to improve their learnability and usability. The study also gave us clear indication of additional potential uses of starfield visualizations that can be exploited by further functionality and interface development. We report on resulting implications for the design and use of starfield visualizations that will impact their graphical interface features, their use for managing data quality and their potential for various forms of visual data mining. Although the current implementation and analysis focuses on the collection of a physical library, the most important contributions of our work will be in digital libraries, in which volume, complexity and dynamism of collections are increasing dramatically and tools are needed for visualization and analysis

Experiences with starfield visualizations for analysis of library collections

This paper presents a qualitative and formative study of the uses of a starfield-based visualization interface for analysis of library collections. The evaluation process has produced feedback that suggests ways to significantly improve starfield interfaces and the interaction process to improve their learnability and usability. The study also gave us clear indication of additional potential uses of starfield visualizations that can be exploited by further functionality and interface development. We report on resulting implications for the design and use of starfield visualizations that will impact their graphical interface features, their use for managing data quality and their potential for various forms of visual data mining. Although the current implementation and analysis focuses on the collection of a physical library, the most important contributions of our work will be in digital libraries, in which volume, complexity and dynamism of collections are increasing dramatically and tools are needed for visualization and analysis

Cumulant expansion for the treatment of light–matter interactions in arbitrary material structures

This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in The Journal of Chemical Physics 152.3 (2020): 034108 and may be found at https://aip.scitation.org/toc/jcp/152/3Strong coupling of quantum emitters with confined electromagnetic modes of nanophotonic structures may be used to change optical, chemical, and transport properties of materials, with significant theoretical effort invested toward a better understanding of this phenomenon. However, a full theoretical description of both matter and light is an extremely challenging task. Typical theoretical approaches simplify the description of the photonic environment by describing it as a single mode or few modes. While this approximation is accurate in some cases, it breaks down strongly in complex environments, such as within plasmonic nanocavities, and the electromagnetic environment must be fully taken into account. This requires the quantum description of a continuum of bosonic modes, a problem that is computationally hard. We here investigate a compromise where the quantum character of light is taken into account at modest computational cost. To do so, we focus on a quantum emitter that interacts with an arbitrary photonic spectral density and employ the cumulant, or cluster, expansion method to the Heisenberg equations of motion up to first, second, and third order. We benchmark the method by comparing it with exact solutions for specific situations and show that it can accurately represent dynamics for many parameter rangesThis work was funded by the European Research Council through Grant No. ERC-2016-StG-714870 and the Spanish Ministry for Science, Innovation, and Universities—Agencia Estatal de Investigación through Grant Nos. RTI2018-099737-B-I00, PCI2018-093145 (through the QuantERA program of the European Commission), and MDM-2014-0377 (through the María de Maeztu program for Units of Excellence in R&D

Participation and Influence of the libero in recepcion and defence, in volleyball U-19

El objetivo fue conocer la participación e influencia líbero en fase de ataque y defensa, en etapas de formación. La muestra fueron 6948 acciones de juego, realizadas por los jugadores de los 21 equipos del Campeonato de España Juvenil masculino. Las variables fueron: función del receptor/defensor, zona de recepción/defensa en profundidad y lateralidad, eficacia de recepción/defensa, zona donde se realiza colocación en recepción/defensa, zona hacia donde se realiza la colocación en recepción/defensa, tiempo de ataque/contraataque y eficacia de ataque/contraataque. En recepción, existió asociación significativa entre función del receptor y zona de recepción en profundidad-lateralidad, y zona donde se realiza la colocación. En defensa, existió asociación significativa entre función del defensor y zona de defensa en profundidad-lateralidad, eficacia de defensa, zona donde se realiza la colocación, zona hacia donde se realiza la colocación y tiempo de contraataque. La influencia del líbero, en estas etapas, se manifiesta más en defensa que en recepciónThe aim was to know the participation and influence of the libero in side-out phase and counter-attack, in young athletes. The sample was 6948 game actions, carried out by the players of the 21 teams that participate in the Under-19 Spanish Championship. The variables were: player that intervened in reception/dig, depth and laterality reception/dig zone, reception/dig efficacy, setting zone in reception/dig, set´s area in reception/dig, tempo of attack/counterattack and attack/counterattack efficacy. In reception, showed significant association between player that intervened in reception, depth-laterality reception zone and the setting zone. In defense, showed significant association between the player that intervened in dig and the depth-laterality dig zone, dig efficacy, setting zone, set´s area and tempo of counterattack. The influence of the participation of the libero, in young athletes, appeared more often in defense than in the receptio

Coupling of mass transfer and reactive transport for nonlinear reactions in heterogeneous media

Fast chemical reactions are driven by mixing‐induced chemical disequilibrium. Mixing is poorly represented by the advection‐dispersion equation. Instead, effective dynamics models, such as multirate mass transfer (MRMT), have been successful in reproducing observed field‐scale transport, notably, breakthrough curves (BTCs) of conservative solutes. The objective of this work is to test whether such effective models, derived from conservative transport observations, can be used to describe effective multicomponent reactive transport in heterogeneous media. We use a localized formulation of the MRMT model that allows us to solve general reactive transport problems. We test this formulation on a simple three‐species mineral precipitation problem at equilibrium. We first simulate the spatial and temporal distribution of mineral precipitation rates in synthetic hydraulically heterogeneous aquifers. We then compare these reaction rates to those corresponding to an equivalent (i.e., same conservative BTC) homogenized medium with transport characterized by a nonlocal in time equation involving a memory function. We find an excellent agreement between the two models in terms of cumulative precipitated mass for a broad range of generally stationary heterogeneity structures. These results indicate that mass transfer models can be considered to represent quite accurately the large‐scale effective dynamics of mixing controlled reactive transport at least for the cases tested here, where individual transport paths sample the full range of heterogeneities represented by the BTC

Establishment of a method for determination of arsenic species in seafood by LC-ICP-MS

An analytical method for determination of arsenic species (inorganic arsenic (iAs), methylarsonic acid (MA), dimethylarsinic acid (DMA), arsenobetaine (AB), trimethylarsine oxide (TMAO) and arsenocholine (AC)) in Brazilian and Spanish seafood samples is reported. This study was focused on extraction and quantification of inorganic arsenic (iAs), the most toxic form. Arsenic speciation was carried out via LC with both anionic and cationic exchange with ICP-MS detection (LC-ICP-MS). The detection limits (LODs), quantification limits (LOQs), precision and accuracy for arsenic species were established. The proposed method was evaluated using eight reference materials (RMs). Arsenobetaine was the main species found in all samples. The total and iAs concentration in 22 seafood samples and RMs ranged between 0.27-35.2 and 0.02-0.71 mg As kg-1, respectively. Recoveries ranging from 100% to 106% for iAs, based on spikes, were achieved. The proposed method provides reliable iAs data for future risk assessment analysis

The colored Hanbury Brown--Twiss effect

The Hanbury Brown--Twiss effect is one of the celebrated phenomenologies of modern physics that accommodates equally well classical (interferences of waves) and quantum (correlations between indistinguishable particles) interpretations. The effect was discovered in the late thirties with a basic observation of Hanbury Brown that radio-pulses from two distinct antennas generate signals on the oscilloscope that wiggle similarly to the naked eye. When Hanbury Brown and his mathematician colleague Twiss took the obvious step to propose bringing the effect in the optical range, they met with considerable opposition as single-photon interferences were deemed impossible. The Hanbury Brown--Twiss effect is nowadays universally accepted and, being so fundamental, embodies many subtleties of our understanding of the wave/particle dual nature of light. Thanks to a novel experimental technique, we report here a generalized version of the Hanbury Brown--Twiss effect to include the frequency of the detected light, or, from the particle point of view, the energy of the detected photons. In addition to the known tendencies of indistinguishable photons to arrive together on the detector, we find that photons of different colors present the opposite characteristic of avoiding each others. We postulate that fermions can be similarly brought to exhibit positive (boson-like) correlations by frequency filtering.Comment: 18 pages, includes supplementary material of the derivation

Coarse-grain molecular dynamics simulation framework to unravel the interactions of surfactants on silica surfaces for oil recovery

A coarse-grained molecular dynamics (CG-MD) framework, based on the MARTINI 3.0 model, was developed to characterise the interactions between surfactants and oil-silica substrates to resemble chemical enhanced oil recovery (EOR) processes. Previous computational studies, at the atomistic scale, addressed interactions between surfactants and oil over diverse surfaces. Even though simulations provided significant information involved throughout different stages of oil extraction from surfaces, atomistic scale simulations fail when approaching the time and size scale required to address the surfactant phase behaviour that can also impact the oil detachment. Our coarse-grained model aims to overcome the lack of computer approaches that can tackle the surfactant self-assembly and the formation of ordered structures in the removal of oil from silica substrates. A new MARTINI 3.0 coarse-grain framework to model silica surfaces and aqueous solutions of CiEj and C16TAB surfactants is presented. Coarse-grained simulations entailing a silica surface, covered by dodecane or eicosane were brought in contact with aqueous solutions of C16TAB and four nonionic CiEj (C8E6, C8E12, C12E6, C16E12) surfactants to resemble EOR processes with a size/time scale several orders of magnitude larger than previous simulations. The impact of concentration and hydrophilic-lipophilic balance (HLB) of surfactants on the detachment of dodecane and eicosane from the silica surface was evaluated by visual inspection of the simulation snapshots and the evolution of the solvent accessible surface areas (SASA). In contrast with previous atomistic simulations, nonionic surfactants seem the best candidates for an optimal oil removal from silica-based surfaces whereas the presence of charged moieties hinders the process. Diluted nonionic CE aqueous solutions were shown to be the most effective solutions, unlike more concentrated ones. When compared with dodecane, eicosane was less prone to be removed from the silica surface due to the increased alkyl chain length. Our study demonstrates that not only the surfactant nature but also the phase behaviour, clearly impact the detachment of oil from silica surfaces. This is an important aspect to consider for a proper choice of surfactants in EOR processes, that is only attainable through a coarse-grained framework.publishe

Dripping Faucet Dynamics Clarified by an Improved Mass-Spring Model

An improved mass-spring model for a dripping faucet is presented. The model is constructed based on the numerical results which we recently obtained from fluid dynamical calculations. Both the fluid dynamical calculations and the present mass-spring model exhibit a variety of complex behavior including transition to chaos in good agreement with experiments. Further, the mass-spring model reveals fundamental dynamics inherent in the dripping faucet system.Comment: 17 pages, 17 figure

South American Expert Roundtable : increasing adaptive governance capacity for coping with unintended side effects of digital transformation

This paper presents the main messages of a South American expert roundtable (ERT) on the unintended side effects (unseens) of digital transformation. The input of the ERT comprised 39 propositions from 20 experts representing 11 different perspectives. The two-day ERT discussed the main drivers and challenges as well as vulnerabilities or unseens and provided suggestions for: (i) the mechanisms underlying major unseens; (ii) understanding possible ways in which rebound effects of digital transformation may become the subject of overarching research in three main categories of impact: development factors, society, and individuals; and (iii) a set of potential action domains for transdisciplinary follow-up processes, including a case study in Brazil. A content analysis of the propositions and related mechanisms provided insights in the genesis of unseens by identifying 15 interrelated causal mechanisms related to critical issues/concerns. Additionally, a cluster analysis (CLA) was applied to structure the challenges and critical developments in South America. The discussion elaborated the genesis, dynamics, and impacts of (groups of) unseens such as the digital divide (that affects most countries that are not included in the development of digital business, management, production, etc. tools) or the challenge of restructuring small- and medium-sized enterprises (whose service is digitally substituted by digital devices). We identify specific issues and effects (for most South American countries) such as lack of governmental structure, challenging geographical structures (e.g., inclusion in high-performance transmission power), or the digital readiness of (wide parts) of society. One scientific contribution of the paper is related to the presented methodology that provides insights into the phenomena, the causal chains underlying “wanted/positive” and “unwanted/negative” effects, and the processes and mechanisms of societal changes caused by digitalization