2,374 research outputs found
BESDUI: A Benchmark for End-User Structured Data User Interfaces
The Semantic Web Community has invested significant research efforts in developing systems for Semantic Web search and exploration. But while it has been easy to assess the systems’ computational efficiency, it has been much harder to assess how well different semantic systems’ user interfaces help their users. In this article, we propose and demonstrate the use of a benchmark for evaluating such user interfaces, similar to the TREC benchmark for evaluating traditional search engines. Our benchmark includes a set of typical user tasks and a well-defined procedure for assigning a measure of performance on those tasks to a semantic system. We demonstrate its application to two such system, Virtuoso and Rhizomer. We intend for this work to initiate a community conversation that will lead to a generally accepted framework for comparing systems and for measuring, and thus encouraging, progress towards better semantic search and exploration tools
Functionalised Poly(Vinyl Alcohol)/Graphene Oxide as Polymer Composite Electrolyte Membranes
[EN] Crosslinked poly(vinyl alcohol) (PVA) based composite films were prepared as polyelectrolyte membranes for low temperature direct ethanol fuel cells (DEFC). The membranes were functionalised by means of the addition of graphene oxide (GO) and sulfonated graphene oxide (SGO) and crosslinked with sulfosuccinic acid (SSA). The chemical structure was corroborated and suitable thermal properties were found. Although the addition of GO and SGO slightly decreased the proton conductivity of the membranes, a significant reduction of the ethanol solution swelling and crossover was encountered, more relevant for those functionalised with SGO. In general, the composite membranes were stable under simulated service conditions. The addition of GO and SGO particles permitted to buffer the loss and almost retain similar proton conductivity than prior to immersion. These membranes are alternative polyelectrolytes, which overcome current concerns of actual commercial membranes such as the high cost or the crossover phenomenon.The authors would like to thank the support of the European Union through the European Regional Development Funds (ERDF). The Spanish Ministry of Economy, Industry and Competitiveness, is thanked for the research project POLYDECARBOCELL (ENE2017-86711-C3-1-R). The Spanish Ministry of Education, Culture and Sports is thanked for the FPU grant for O. Gil-Castell (FPU13/01916).Gil Castell, Ó.; Cerveró, R.; Teruel Juanes, R.; Badia, JD.; Ribes Greus, MD. (2019). Functionalised Poly(Vinyl Alcohol)/Graphene Oxide as Polymer Composite Electrolyte Membranes. Journal of Renewable Materials. 7(7):655-665. https://doi.org/10.32604/jrm.2019.04401S6556657
Functionalised poly (vinyl alcohol)/graphene oxide as polymer composite electrolyte membranes
Crosslinked poly(vinyl alcohol) (PVA) based composite films were prepared as polyelectrolyte membranes for low temperature direct ethanol fuel cells (DEFC). The membranes were functionalised by means of the addition of graphene oxide (GO) and sulfonated graphene oxide (SGO) and crosslinked with sulfosuccinic acid (SSA). The chemical structure was corroborated and suitable thermal properties were found. Although the addition of GO and SGO slightly decreased the proton conductivity of the membranes, a significant reduction of the ethanol solution swelling and crossover was encountered, more relevant for those functionalised with SGO. In general, the composite membranes were stable under simulated service conditions. The addition of GO and SGO particles permitted to buffer the loss and almost retain similar proton conductivity than prior to immersion. These membranes are alternative polyelectrolytes, which overcome current concerns of actual commercial membranes such as the high cost or the crossover phenomenon
Material Properties of GaN in the Context of Electron Devices
AbstractWide bandgap nitride semiconductors have recently attracted a great level of attention owing to their direct bandgaps in the visible to ultraviolet regions of the spectrum as emitters and detectors. However, this material system with its favorable heterojunctions and transport properties began to produce very respectable power levels in microwave amplifiers. If and when the breakdown fields achieved experimentally approaches the predicted values, this material system may also be very attractive for switching power devices. In addition to the premature breakdown, a number of scientific challenges remain including a clear experimental investigation of polarization effects. In this paper, transport properties as pertained to electronic devices and potential switching devices, and polarization effects will be treated
Verificación de un nivel óptico
El objetivo de este trabajo consiste en implementar y analizar un método de campo para verificar si el instrumento se encuentra apto para la realización de una determinada tarea según la Norma ISO 4463-1. S e utilizó el procedimiento simplificado de la Norma ISO 17123-2 (Óptica e instrumentos ópticos-Procedimientos de campo para pruebas de instrumentos topográficos y geodésicos – Parte 2 Niveles). Durante la ejecución del trabajo y por cuestiones prácticas se utilizó el Nivel Automático Sokkia C28 (disponible en el Departamento de Agrimensura) cuya desviación estándar establecida en el Manual del Fabricante es de 2 mm en una nivelación de 1 km ida y vuelta.Facultad de Ingenierí
Caracterização morfométrica das lesões do colo uterino relacionadas ao vírus da papilomatose humana
Este estudo é voltado para os seguintes aspectos ligados às lesões cervicais relacionadas ao Vírus da Papilomatose Humana (VPH): 1) identificação do vírus em tecido histologicamente normal; 2) diferenciação morfométrica das alterações induzidas pelo subtipo do VPH em condilomas, e 3) as diferenças morfométricas entre condiloma puro e Neoplasia Cervical lntraepitelial do Grau 1 (NIC 1). Usamos o índice morfométrico núcleo/citoplasmático para as medidas da área, perímetro e máximo diâmetro, da célula e do núcleo celular. Quarenta e oito lâminas de biópsias cervicais foram estudadas e os achados, classificados dentro de três grupos: normal (22 casos), condiloma (20 casos) e NIC 1 (6 casos). A presença do DNA do VPH, detectada usando-se a metodologia da hibridização in situ, foi usada para estudar se o tecido histologicamente normal seria reconhecido como sendo infectado pelo VPH. Os casos de condiloma foram então comparados por meio de análise morfométrica para o subtipo do DNA do VPH por hibridização in situ, a fim de diferenciar os subtipos de VPH de baixo e alto risco. Os parâmetros foram avaliados por análise multivariada e demonstraram classificar corretamente todos os casos, exceto dois, com uma probabilidade posterior bastante elevada. Concluímos que os dados morfométricos foram úteis no diagnóstico diferencial entre as lesões cervicais relacionadas ao VPH
Solving the mu problem with a heavy Higgs boson
We discuss the generation of the mu-term in a class of supersymmetric models
characterized by a low energy effective superpotential containing a term lambda
S H_1 H_2 with a large coupling lambda~2. These models generically predict a
lightest Higgs boson well above the LEP limit of 114 GeV and have been shown to
be compatible with the unification of gauge couplings. Here we discuss a
specific example where the superpotential has no dimensionful parameters and we
point out the relation between the generated mu-term and the mass of the
lightest Higgs boson. We discuss the fine-tuning of the model and we find that
the generation of a phenomenologically viable mu-term fits very well with a
heavy lightest Higgs boson and a low degree of fine-tuning. We discuss
experimental constraints from collider direct searches, precision data, thermal
relic dark matter abundance, and WIMP searches finding that the most natural
region of the parameter space is still allowed by current experiments. We
analyse bounds on the masses of the superpartners coming from Naturalness
arguments and discuss the main signatures of the model for the LHC and future
WIMP searches.Comment: Extended discussion of the LHC phenomenology, as published on JHEP
plus an addendum on the existence of further extremal points of the
potential. 47 pages, 16 figure
TAML/H2O2 oxidative degradation of metaldehyde: Pursuing better water treatment for the most persistent pollutants.
The extremely persistent molluscicide, metaldehyde, widely used on farms and gardens, is often detected in drinking water sources of various countries at concentrations of regulatory concern. Metaldehyde contamination restricts treatment options. Conventional technologies for remediating dilute organics in drinking water, activated carbon and ozone, are insufficiently effective against metaldehyde. Some treatment plants have resorted to effective, but more costly UV/H2O2. Here we have examined if TAML/H2O2 can decompose metaldehyde under laboratory conditions to guide development of a better real world option. TAML/H2O2 slowly degrades metaldehyde to acetaldehyde and acetic acid. Nuclear magnetic resonance spectroscopy ((1)H NMR) was used to monitor the degradation-the technique requires a high metaldehyde concentration (60 ppm). Within the pH range of 6.5-9, the reaction rate is greatest at pH 7. Under optimum conditions, one aliquot of TAML 1a (400 nM) catalyzed 5% degradation over 10 hours with a turnover number of 40. Five sequential TAML aliquots (2 μM overall) effected a 31% removal over 60 hours. TAML/H2O2 degraded metaldehyde steadily over many hours, highlighting an important long-service property. The observation of metaldehyde decomposition under mild conditions provides a further indication that TAML catalysis holds promise for advancing water treatment. These results have turned our attention to more aggressive TAML activators in development, which we expect will advance the observed technical performance
Selenium and impaired physical function in US and Spanish older adults
Background: Selenium (Se) is a trace element with a narrow safety margin.
Objectives: To evaluate the cross-sectional and longitudinal dose-response association between Se exposure and
measures of impaired physical function and disability in older adults.
Design: NHANES 2011–2014 cross-sectional (US, n = 1733, age ≥60 years) and Seniors-ENRICA-2 2017–2019
cross-sectional and longitudinal (Spain, n = 2548 and 1741, respectively, age ≥65 years) data were analyzed.
Whole blood and serum Se levels were measured using inductively coupled plasma-mass spectrometry. Lowerextremity
performance was assessed with the Short Physical Performance Battery, and muscle weakness with
a dynamometer. Incident mobility and agility limitations, and disability in instrumental activities of daily living
(IADL) were ascertained with standardized questionnaires. Analyses were adjusted for relevant confounders,
including physical activity. Results across studies were pooled using random-effects meta-analysis.
Results: Meta-analyzed odds ratios (95% confidence interval) per log2 increase in whole blood Se were 0.54
(0.32; 0.76) for weakness, 0.59 (0.34; 0.83) for impaired lower-extremity performance, 0.48 (0.31; 0.68) for
mobility limitations, 0.71 (0.45; 0.97) for agility limitations, and 0.34 (0.12; 0.56) for disability in at least one
IADL. Analyses for serum Se in NHANES showed similar results. Findings suggest the inverse association with
grip strength is progressive below 140 μg/L (p-value for non-linear trend in the Seniors-ENRICA-2 study = 0.13),
and above 140 μg/L (p-value for non-linear trend in NHANES = 0.11). In the Seniors-ENRICA-2 cohort, with a
2.2 year follow-up period, a doubling in baseline Se levels were associated with a lower incidence of weakness
[odds ratio (95% confidence interval): 0.45 (0.22; 0.91)], impaired lower-extremity performance [0.63 (0.32;
1.23)], mobility [0.43 (0.21; 0.91)] and agility [0.38 (0.18; 0.78)] limitations.
Discussion: In US and Spanish older adults, Se concentrations were inversely associated with physical function
limitations. Further studies are needed to elucidate underlying mechanisms.Instituto de Salud Carlos III
European Commission
PI18/287
16/609State Secretary of R + D + I
PID2019-108973RB-C21/C22European Social Fund (ESF)
European Commissio
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