scholarly journals Calculations of current densities for neutral and doubly charged persubstituted benzenes using effective core potentials

2017 ◽  
Vol 19 (10) ◽  
pp. 7124-7131 ◽  
Author(s):  
Markus Rauhalahti ◽  
Stefan Taubert ◽  
Dage Sundholm ◽  
Vincent Liégeois
Keyword(s):  
Current Density ◽  
Induced Current ◽  
Current Densities ◽  
Doubly Charged ◽  
Effective Core Potentials

Magnetically induced current density of C6I62+ using GIMIC method and effective core potentials.

Magnetically induced current density in triple-layered beryllium–boron clusters

2019 ◽  
Vol 21 (13) ◽  
pp. 7105-7114 ◽  
Author(s):  
Slađana Đorđević ◽  
Slavko Radenković
Keyword(s):  
Current Density ◽  
Induced Current ◽  
Boron Clusters ◽  
Aromatic Character ◽  
Current Densities

Magnetically induced current densities reveal the double aromatic character of the examined Be–B clusters.

scholarly journals Analysis of the magnetically induced current density of molecules consisting of annelated aromatic and antiaromatic hydrocarbon rings

2016 ◽  
Vol 18 (23) ◽  
pp. 15934-15942 ◽  
Author(s):  
Dage Sundholm ◽  
Raphael J. F. Berger ◽  
Heike Fliegl
Keyword(s):  
Current Density ◽  
Induced Current ◽  
Current Densities ◽  
Aromatic Pathway

The aromatic pathway of molecules with annelated aromatic and antiaromatic rings has been studied by calculating magnetically induced current densities.

scholarly journals The B2 Structural Motif as a Tool for Modulating Ring Currents in Monocyclic Li Clusters

Chemistry ◽  
2021 ◽  
Vol 3 (3) ◽  
pp. 1063-1073
Author(s):  
Slađana Đorđević ◽  
Slavko Radenković
Keyword(s):  
Current Density ◽  
Structural Motif ◽  
Induced Current ◽  
Continuous Transformation ◽  
Structural Modifications ◽  
Ring Currents ◽  
Current Densities

Magnetically induced current densities, calculated at the M06-2X/def2-TZVP level using the diamagnetic-zero version of the continuous transformation of origin of current density (CTOCD-DZ) method, were employed to study the aromaticity in Li3B2− and Li4B2. It was found that the Li3/Li4 rings in Li3B2− and Li4B2 remarkably resemble the monocyclic Li3+ and Li42+ clusters. Unlike the parent Li3+ and Li42+ systems that sustain negligibly weak global current density circulation, the Li3B2− and Li4B2 clusters exhibit a strong diatropic current density. The present work demonstrates how structural modifications introduced by the B2 unit can be used for modulating the current density in cyclic Li-based clusters.

scholarly journals Aromaticity of the doubly charged [8]circulenes

2016 ◽  
Vol 18 (13) ◽  
pp. 8980-8992 ◽  
Author(s):  
Gleb V. Baryshnikov ◽  
Rashid R. Valiev ◽  
Nataliya N. Karaush ◽  
Dage Sundholm ◽  
Boris F. Minaev
Keyword(s):  
Induced Current ◽  
Current Densities ◽  
Doubly Charged

Magnetically induced current densities and current pathways have been calculated for a series of fully annelated dicationic and dianionic tetraphenylenes, which are also named [8]circulenes.

scholarly journals New insights into aromatic pathways of carbachlorins and carbaporphyrins based on calculations of magnetically induced current densities

2016 ◽  
Vol 18 (17) ◽  
pp. 11932-11941 ◽  
Author(s):  
Isaac Benkyi ◽  
Heike Fliegl ◽  
Rashid R. Valiev ◽  
Dage Sundholm
Keyword(s):  
Current Density ◽  
Induced Current ◽  
Current Densities

The aromatic pathways of carbaporphyrins and carbachlorins that are based on magnetically induced current density DFT-GIMIC calculations are presented and discussed.

Facet Topography and Dislocation Structure as a Possible Source for Electrical Heterogeneity in [001] TILT Bicrystals of YBa2Cu3O7-δ

1996 ◽  
Vol 54 ◽  
pp. 338-339
Author(s):  
I-Fei Tsu ◽  
D.L. Kaiser ◽  
S.E. Babcock
Keyword(s):  
Grain Boundary ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Electromagnetic Properties ◽  
Length Scale ◽  
Density Values ◽  
Current Densities ◽  
Applied Fields ◽  
A Current

A current theme in the study of the critical current density behavior of YBa2Cu3O7-δ (YBCO) grain boundaries is that their electromagnetic properties are heterogeneous on various length scales ranging from 10s of microns to ˜ 1 Å. Recently, combined electromagnetic and TEM studies on four flux-grown bicrystals have demonstrated a direct correlation between the length scale of the boundaries’ saw-tooth facet configurations and the apparent length scale of the electrical heterogeneity. In that work, enhanced critical current densities are observed at applied fields where the facet period is commensurate with the spacing of the Abrikosov flux vortices which must be pinned if higher critical current density values are recorded. To understand the microstructural origin of the flux pinning, the grain boundary topography and grain boundary dislocation (GBD) network structure of [001] tilt YBCO bicrystals were studied by TEM and HRTEM.

Electron-beam damage of oxides at high current densities

1989 ◽  
Vol 47 ◽  
pp. 634-635
Author(s):  
M. R. McCartney ◽  
J. K. Weiss ◽  
David J. Smith
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Current Density ◽  
Transition Metal Oxides ◽  
Time Resolved ◽  
Rapid Acquisition ◽  
Resolution Electron ◽  
Current Densities ◽  
Electron Stimulated Desorption ◽  
Channel Analyzer

It is well-known that electron-beam irradiation within the electron microscope can induce a variety of surface reactions. In the particular case of maximally-valent transition-metal oxides (TMO), which are susceptible to electron-stimulated desorption (ESD) of oxygen, it is apparent that the final reduced product depends, amongst other things, upon the ionicity of the original oxide, the energy and current density of the incident electrons, and the residual microscope vacuum. For example, when TMO are irradiated in a high-resolution electron microscope (HREM) at current densities of 5-50 A/cm2, epitaxial layers of the monoxide phase are found. In contrast, when these oxides are exposed to the extreme current density probe of an EM equipped with a field emission gun (FEG), the irradiated area has been reported to develop either holes or regions almost completely depleted of oxygen. ’ In this paper, we describe the responses of three TMO (WO3, V2O5 and TiO2) when irradiated by the focussed probe of a Philips 400ST FEG TEM, also equipped with a Gatan 666 Parallel Electron Energy Loss Spectrometer (P-EELS). The multi-channel analyzer of the spectrometer was modified to take advantage of the extremely rapid acquisition capabilities of the P-EELS to obtain time-resolved spectra of the oxides during the irradiation period. After irradiation, the specimens were immediately removed to a JEM-4000EX HREM for imaging of the damaged regions.

scholarly journals Effect of Plating Current Density on the Ball-On-Disc Wear of Sn-Plated Ni Coatings on Cu Foils

Coatings ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 56
Author(s):  
Ashutosh Sharma ◽  
Byungmin Ahn
Keyword(s):  
Current Density ◽  
Wear Loss ◽  
Wear Properties ◽  
Friction Behavior ◽  
Track Geometry ◽  
Cu Substrates ◽  
Current Densities ◽  
The Impact ◽  
Sliding Distance ◽  
Ball On Disc

Metallic and alloyed coatings are used widely in several decorative and technology-based applications. In this work, we selected Sn coatings plated on Cu substrates for joining applications. We employed two different plating baths for the fabrication of Sn and Ni coatings: acidic stannous sulfate for Sn and Watts bath for Ni layer. The plating current densities were varied from 100–500 mA/cm2. Further, the wear and friction behavior of the coatings were studied using a ball-on-disc apparatus under dry sliding conditions. The impact of current density was studied on the morphology, wear, and coefficient of friction (COF) of the resultant coatings. The wear experiments were done at various loads from 2–10 N. The sliding distance was fixed to 7 m. The wear loss was quantified in terms of the volume of the track geometry (width and depth of the tracks). The results indicate that current density has an important role in tailoring the composition and morphology of coatings, which affects the wear properties. At higher loads (8–10 N), Sn coatings on Ni/Cu had higher volume loss with a stable COF due to a mixed adhesive and oxidative type of wear mechanism.

Chronic receptor-mediated activation of Gi/o proteins alters basal t-tubular and sarcolemmal L-type Ca2+ channel activity through phosphatases in heart failure

2012 ◽  
Vol 302 (8) ◽  
pp. H1645-H1654 ◽  
Author(s):  
Toshihide Kashihara ◽  
Tsutomu Nakada ◽  
Hisashi Shimojo ◽  
Miwa Horiuchi-Hirose ◽  
Simmon Gomi ◽  
...  
Keyword(s):  
Heart Failure ◽  
Current Density ◽  
Ventricular Myocytes ◽  
Heterotrimeric G Proteins ◽  
Channel Activity ◽  
Open Probability ◽  
Current Densities ◽  
Fractional Shortening ◽  
Pp2a Inhibitor

L-type Ca2+ channels (LTCCs) play an essential role in the excitation-contraction coupling of ventricular myocytes. We previously found that t-tubular (TT) LTCC current density was halved by the activation of protein phosphatase (PP)1 and/or PP2A, whereas surface sarcolemmal (SS) LTCC current density was increased by the inhibition of PP1 and/or PP2A activity in failing ventricular myocytes of mice chronically treated with isoproterenol (ISO mice). In the present study, we examined the possible involvement of inhibitory heterotrimeric G proteins (Gi/o) in these abnormalities by chronically administrating pertussis toxin (PTX) to ISO mice (ISO + PTX mice). Compared with ISO mice, ISO + PTX mice exhibited significantly higher fractional shortening of the left ventricle. The expression level of Gαi2 proteins was not altered by the treatment of mice with ISO and/or PTX. ISO + PTX myocytes had normal TT and SS LTCC current densities because they had higher and lower availability and/or open probability of TT and SS LTCCs than ISO myocytes, respectively. A selective PKA inhibitor, H-89, did not affect LTCC current densities in ISO + PTX myocytes. A selective PP2A inhibitor, fostriecin, did not affect SS or TT current density in control or ISO + PTX myocytes but significantly increased TT but not SS LTCC current density in ISO myocytes. These results indicate that chronic receptor-mediated activation of Gi/o in vivo decreases basal TT LTCC activity by activating PP2A and increases basal SS LTCC activity by inhibiting PP1 without modulating PKA in heart failure.

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