Search results for "Current"

Effects of tDCS on Bimanual Motor Skills: A Brief Review

2018

Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique that allows the modulation of cortical excitability as well as neuroplastic reorganization using a weak constant current applied through the skull on the cerebral cortex. TDCS has been found to improve motor performance in general and motor learning in particular. However, these effects have been reported almost exclusively for unimanual motor tasks such as serial reaction time tasks, adaptation tasks, or visuo-motor tracking. Despite the importance of bimanual actions in most activities of daily living, only few studies have investigated the effects of tDCS on bimanual motor skills. The objectives …

Numerical construction of the density-potential mapping

2018

We demonstrate how a recently developed method Nielsen et al. [Nielsen et al., EPL 101, 33001 (2013)] allows for a comprehensive investigation of time-dependent density functionals in general, and of the exact time-dependent exchange-correlation potential in particular, by presenting the first exact results for two- and three-dimensional multi-electron systems. This method is an explicit realization of the Runge–Gross correspondence, which maps time-dependent densities to their respective potentials, and allows for the exact construction of desired density functionals. We present in detail the numerical requirements that makes this method efficient, stable and precise even for large and rap…

Great expectations: Learning the boundaries of design rights

2019

We present a case study of an increase in design right filings and concurrent design right litigations in an industry that previously had little experience of design right protection. The motives for and outcomes of filing, and how these changed over time are discussed. We go on to explore the events, which offered the decision makers opportunities to update their beliefs about the scope of design right protection. We find that filing motives changed from specific protection goals to freedom to operate over time. We also find that the actors faced several, but sometimes contradictory, learning opportunities. There are two types of learning relating to the usage of design rights: 1) learning…

A posteriori error control for Maxwell and elliptic type problems

2014

Net currents obtained from zero-average potentials in single amphoteric nanopores

2013

We have studied experimentally and theoretically the rectifying properties of a single asymmetric nanopore functionalized with amphoteric lysine groups and characterized the net current obtained with zero-average time dependent potentials. The pH-controlled rectification phenomena may be relevant to bio-electrochemistry, pH sensing and regulation, and energy conversion. (C) 2013 Elsevier B.V. All rights reserved.

Partnership formation and dissolution over the life course: applying sequence analysis and event history analysis in the study of recurrent events

2015

We present two types of approach to the analysis of recurrent events for discretely measured data, and show how these methods can complement each other when analysing co-residential partnership histories. Sequence analysis is a descriptive tool that gives an overall picture of the data and helps to find typical and atypical patterns in histories. Event history analysis is used to make conclusions about the effects of covariates on the timing and duration of the partnerships. As a substantive question, we studied how family background and childhood socio-emotional characteristics were related to later partnership formation and stability in a Finnish cohort born in 1959. We found that high se…

Experimental test of the performances of a photovoltaic modules model

2015

In this paper, a measurement-based modeling technique for PV panels oriented to power electronics design is proposed. The proposed modelling approach aims at an accurate modeling of the whole PV curve and not only around a few remarkable points. The proposed approach is based on an experimental characterization of the module under test. In fact, the incompleteness of manufacturers' data and the knowledge of physical parameters are the main source of inaccuracy in existing modelling approaches. The proposed approach is applied to a four lumped parameters model of a Conergy E215P solar module. Tests are performed under natural light. The parameter identification procedure is described in deta…

Photoelectron emission experiments with ECR-driven multi-dipolar negative ion plasma source

2017

Photoelectron emission measurements have been performed using a 2.45 GHz ECR-driven multi-dipolar plasma source in a low pressure hydrogen discharge. Photoelectron currents induced by light emitted from ECR zone and H− production region are measured from Al, Cu, Mo, Ta, and stainless steel (SAE 304) surfaces as a function of microwave power and neutral hydrogen pressure. The total photoelectron current from the plasma chamber wall is estimated to reach values up to 1 A for 900 W of injected microwave power. It is concluded that the volumetric photon emission rate in wavelength range relevant for photoelectron emission is a few times higher in arc discharge. peerReviewed

Partial Discharges in HVDC Cables - The Effect of the Temperature Gradient During Load Transients

2021

The paper investigates the role of the space charge accumulation phenomena in the inception of Partial Discharges (PD) in a defect within the bulk of the dielectrics of a High Voltage Direct Current (HVDC) cable. It is widespread accepted that the number of PD occurring in an HVDC cable during its lifetime is largely less than that under AC voltage stress. This is essentially due to higher values of the voltage between the conductor and the screen needed to trigger PD under a steady DC voltage than the same value under AC stress. Nevertheless, due to the dependency of the electrical conductivity of the insulation on the electric field and temperature, PD in HVDC cables is strongly influence…

The Fear of Covid-19 Scale (FCV-19S) in Spain: Adaptation and Confirmatory Evidence of Construct and Concurrent Validity

2021

Fear of the coronavirus has important implications on mental health. In western countries, a significant degree of vaccination has been achieved, but in Spain, less than 75% of the population has received both doses. The current situation is still seen as a threat by many people. Therefore, it is important to have reliable and valid measurement instruments to assess the impact of COVID-19 on the population. In this study, the Fear of COVID-19 Scale has been adapted to Spain, and its psychometric properties have been studied in a Spanish sample using Structural Equation Modeling. This methodology allows obtaining more reliable estimates, regardless of the measurement scale of the variables. …