Search results for "current"

Current density maps, magnetizability, and nuclear magnetic shielding tensors of bis-heteropentalenes. III. Thieno-thiophene isomers

2005

Near Hartree–Fock values of the magnetic susceptibility and nuclear magnetic shielding of bis-heteropentalenes consisting of two thiophene units ([2,3-b], [3,2-b], [3,4-b], and [3,4-c] isomers) have been estimated via computational schemes relying on continuous transformation of the origin of the current density within the coupled Hartree–Fock approximation and extended gaugeless Gaussian basis sets. The results are compared with those obtained via London gauge-including orbitals. Maps of streamlines and the modulus of the ring current density induced by a magnetic field normal to the molecular plane are reported for the three isomers of higher symmetry, showing that the intense diamagnetic…

Study of the pyroelectricity in LiIns2 crystal

2002

Abstract Pyroelectric current measurements performed on a LiInS2 monodomain single crystal show a linear variation of the current between 120 and 260 K. Near room temperature, a space charge relaxation screens pyroelectricity. The pyroelectric coefficient follows a linear thermal dependence leading to an extrapolated value of 6×10−10 C K−1 cm−2 at 300 K. As for other oxide-type pyroelectric compounds, this value is shown to be proportional to the electro-optic coefficient r333 of LiInS2.

Evidence of validity and measurement invariance by gender of the Vaccination Attitudes Examination (VAX) scale in Colombian university students

2022

Background: Having a valid tool to assess attitudes toward vaccination and identify the concerns that drive vaccine refusal can facilitate population studies and help guide public health interventions. The objective of this study has been to adapt the Vaccination Attitudes Examination (VAX) scale in Colombian university students and to study its psychometric properties in a non-probabilistic sample of 1074 Colombian university students. Methods: A confirmatory factor analysis was used to study the factorial structure. A structural equation model was tested to study concurrent validity and to check whether the factors predicted having received the coronavirus vaccine. Gender-based measuremen…

Light induced electropolymerization of poly(3,4-ethylenedioxythiophene) on niobium oxide

2010

Abstract The photoelectrochemical polymerization of poly(3,4-ethylenedioxythiophene), PEDOT, was successfully realized on anodic film grown to 50 V on magnetron sputtered niobium. Photocurrent Spectroscopy was employed to study the optical properties of Nb/Nb 2 O 5 /PEDOT/electrolyte interface in a large range of potential, and to get an estimate of the band gap and flat band potential of both the oxide and the polymer. Scanning Electron Microscopy was used to study the morphology of PEDOT. Both the optical and morphological features of the photoelectrochemically grown polymer were compared with those showed by PEDOT electropolymerized on gold conducting substrate.

New foundings of contourite deposits in an active continental margin (Southern Tyrrhenian Sea)

2014

The effect of the axial heat transfer on space charge accumulation phenomena in HVDC cables

2020

To date, it has been widespread accepted that the presence of space charge within the dielectric of high voltage direct current (HVDC) cables is one of the most relevant issues that limits the growing diffusion of this technology and its use at higher voltages. One of the reasons that leads to the establishment of space charge within the insulation of cables is the temperature dependence of its conductivity. Many researchers have demonstrated that high temperature drop over the insulation layer can lead to the reversal of the electric field profile. In certain conditions, this can over-stress the insulation during polarity reversal (PR) and transient over voltages (TOV) events accelerating …

Investigation of the Temperature Sensitivity of 20-Years Old Field-Aged Photovoltaic Panels Affected by Potential Induced Degradation

2022

One effect of moisture ingress on solar panels is potential induced degradation (PID). Solar panels affected by PID experience large leakage currents between the solar cells and the module’s frame, which leads to substantial power degradation. In the present work, the temperature coefficients of 3 old PV panels affected by PID were investigated. In the electroluminescence images, solar cells nearer to the edge of the modules appear darker due to ohmic shunting. IR thermal images acquired under clear sky outdoor conditions show that the majority of the warmer cells (hotspots) were located closer to the edge of the modules. The difference in cell temperature (∆T) due to PID effect…

Simulations of convectively-driven density currents in the Atlas region using a regional model: Impacts on dust emission and sensitivity to horizonta…

2009

[1] During the SAMUM field campaign in southern Morocco in May and June 2006 density currents generated by evaporative cooling after convective precipitation were frequently observed at the Sahara side of the Atlas Mountain chain. The associated strong surface cold-air outflow during such events has been observed to lead to dust mobilization in the foothills. Here a regional model system is used to simulate a density current case on 3 June 2006 and the subsequent dust emission. The model studies are performed with different parameterization schemes for convection, and with different horizontal model grid resolutions to examine to which extent the model system can be used for reproducing dus…

Generalization of a finite-difference numerical method for the steady-state and transient solutions of the nernst—planck flux equations

1985

Abstract A generalization of the numerical method of Brumleve and Buck for the solution of Nernst—Planck equations when convective flux and electric current are involved has been developed. The simulation procedure was applied to a specific case: transport of strong electrolytes in a wide-pore membrane with simultaneous diffusion, convection and electric current. Good agreement was found between experimental data and computed results.

Psychometric properties of the stress control mindset measure in university students from Australia and the UK

2021

Abstract Introduction Beliefs about the consequences of stress, stress mindsets, are associated with health and performance outcomes under stress. This article reports the development and examination of the psychometric properties of a measure of stress mindset: The Stress Control Mindset Measure (SCMM). The measure is consistent with theory on mindsets about self‐attributes and conceptualizes stress mindset as the extent to which individuals endorse beliefs that stress can be enhancing. Methods The study adopted a correlational cross‐sectional survey design in two student samples. Undergraduate students from an Australian university (Sample 1, N = 218) and a UK university (Sample 2, N = 21…