Measurements of the Net Charge Density of Space Plasmas

Schematic illustration of the hybrid method model. ρ is the net charge density calculated from cDFT. v is the velocity calculated from non-equilibrium MD simulation. b and αW are the slipping length and the surface properties, respectively.

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Interfacial net charge density of nonintimate Schottky junctions

Journal of Applied Physics ◽

10.1063/1.1453493 ◽

2002 ◽

Vol 91 (7) ◽

pp. 4281-4290 ◽

Cited By ~ 6

Author(s):

B. Cvikl ◽

D. Korošak

Keyword(s):

Charge Density ◽

Net Charge ◽

Schottky Junctions

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Forces between dissimilar colloidal plates for various surface conditions. II. Equilibrium adsorption effects

Canadian Journal of Chemistry ◽

10.1139/v81-281 ◽

1981 ◽

Vol 59 (13) ◽

pp. 1888-1897 ◽

Cited By ~ 5

Author(s):

G. M. Bell ◽

G. C. Peterson

Keyword(s):

Charge Density ◽

Double Layer ◽

Equilibrium Adsorption ◽

Total Charge ◽

Net Charge ◽

Adsorption Models ◽

Ionic Adsorption ◽

Counter Ions ◽

Weak Adsorption ◽

Anions And Cations

A method previously developed by the authors is used to study the effects of adsorption of ions on the electric double layer interaction between dissimilar colloidal plates immersed in 1:1 electrolyte. For adsorption models which permit the total charge on a plate to change sign, the double layer force remains finite at all plate separations, including zero. For weak adsorption of the ions on the plates the force between two dissimilar plates tends to be repulsive at small separations, looking rather like a weakened constant surface charge density model. Conversely for strong ionic adsorption the force tends to be attractive at small separations, rather as in the constant surface potential model. In this paper we discuss three adsorption models: (1) fixed primary charge density on the plates with secondary adsorption of both counter-ions and co-ions; (2) fixed primary charge density on the plates with secondary adsorption of the counter-ions only, but including the effects of a Stern layer and self-atmosphere potentials; (3) zero primary charge on both plates with equilibrium adsorption of both anions and cations from solution, the net charge density on the plates arising from differential adsorption of the ion types.

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Requirement for negatively charged dispersions of phospholipids for interaction with lipid-depleted adenosine triphosphatase

Biochemical Journal ◽

10.1042/bj1770265 ◽

1979 ◽

Vol 177 (1) ◽

pp. 265-273 ◽

Cited By ~ 16

Author(s):

M Isern de Caldentey ◽

K P Wheeler

Keyword(s):

Charge Density ◽

Protein Interaction ◽

Adenosine Triphosphatase ◽

Negative Charge ◽

Enzyme Reaction ◽

Enzyme Protein ◽

Net Charge ◽

Lipid Protein Interaction ◽

Acyl Chains

The basis of the requirement for a net negative charge on phospholipid dispersions able to re-activate lipid-depleted (Na++K+)-dependent adenosine triphosphatase was studied. The origin and density of the charge in phospholipid dispersions were varied before interaction with the adenosine triphosphatase protein, and the charge density on restored phospholipid-adenosine triphosphatase complexes was changed after interaction. The results indicated that: (a) re-activation requires a lamellar arrangement of the lipid molecules with sufficient density of negative charge, but not necessarily negatively charged phospholipid molecules; (b) the net charge appears to be necessary for the correct interaction between the enzyme protein and the phospholipids, although the amount of phospholipid that binds to the protein is also a function of the nature of the acyl chains; (c) it is not possible on the basis of these findings and those in the literature to decide unequivocally if the charge is also required for the enzyme reaction itself. The possible relevance of the findings to the situation in vivo is discussed in terms of the charge being concerned only with lipid-protein interaction.

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Protein and Nanoparticle Adsorption on Orthogonal, Charge-Density-Versus-Net-Charge Surface-Chemical Gradients

Langmuir ◽

10.1021/la203964a ◽

2012 ◽

Vol 28 (6) ◽

pp. 3159-3166 ◽

Cited By ~ 17

Author(s):

Eva Beurer ◽

Nagaiyanallur V. Venkataraman ◽

Marianne Sommer ◽

Nicholas D. Spencer

Keyword(s):

Charge Density ◽

Surface Chemical ◽

Net Charge ◽

Chemical Gradients

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Simulation of space charge transport in solid dielectric materials using transmission lines modeling method

Journal of Advanced Dielectrics ◽

10.1142/s2010135x19500516 ◽

2019 ◽

Vol 09 (06) ◽

pp. 1950051

Author(s):

Amin Shamsi ◽

Alireza Ganjovi ◽

Amirabbas Shayegani Akmal

Keyword(s):

Transmission Line ◽

Charge Density ◽

Space Charge ◽

Current Density ◽

Dielectric Material ◽

Dielectric Materials ◽

Solid Dielectric ◽

Recombination Rates ◽

Net Charge ◽

Charged Species

In this paper, a lumped RC circuit model, which is based on the Transmission Line Modeling (TLM) method, is used to describe the space charge production and displacement mechanisms in three different solid dielectric materials (LDPE, PTFE and FR4). Each dielectric material is considered as a transmission line with the capacitive and resistance elements. The obtained circuit equations are solved along with the continuity equations for the various charged species in the bulk of solid dielectric material. The electric potential and field, density of different charged species and their recombination rates, resistive and capacitive properties of the solid dielectric material are calculated. In addition, the effects of the variations in the applied voltage, dielectric permittivity and temperature on these physical parameters are examined. Besides, compared with LDPE and PTFE, the net charge density increment rate in FR4 is much higher. Moreover, the influences of temperature on the net charge density in LDPE are not significant. Furthermore, at the higher applied voltages, the current density is increased. Interestingly, the effects of temperature variations on the recombination rates, net charge and current density in LDPE are much lower. Hence, the suitability of LDPE as solid dielectric material is proved.

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Surface Charge Properties Of Kaolinite

MRS Proceedings ◽

10.1557/proc-432-87 ◽

1996 ◽

Vol 432 ◽

Cited By ~ 4

Author(s):

B.K. Schroth ◽

G. Sposito

Keyword(s):

Charge Density ◽

Surface Charge ◽

Mixing Time ◽

Mineral Dissolution ◽

Degree Of Crystallinity ◽

Charge Balance ◽

Net Charge ◽

Proton Charge ◽

Dependent Behavior ◽

Good Agreement

AbstractThe surface charge components of two Georgia kaolinites of differing degree of crystallinity (KGa-1 and KGa-2) were measured using procedures based on charge balance concepts. Permanent structural charge density (Σ0) was determined by measuring the surface excess of Cs, which is highly selective to permanent charge sites. The values of Σ0 determined were -6.3 ± 0.1 and -13.6 ± 0.5 mmol kg-1 for kaolinites KGa-l and KGa-2, respectively. The net proton surface charge density (σH) was determined as a function of pH by potentiometric titration in 0.01 mol dm-3 LiC1. Correction from apparent to absolute values of ΣH was made by accounting for Al release during dissolution, background ion adsorption, and charge balance. Lithium and Cl adsorption accounted for the remainder of the surface charge components. Changes in surface charge properties with time were measured after mixing times of 1, 3, and 15 hours (the latter representing “equilibrium”). Time-dependent behavior is believed to be caused by mineral dissolution followed by readsorption or precipitation of Al on the mineral surface. Both the point of zero net charge (p.z.n.c.) and the point of zero net proton charge (p.z.n.p.c.) changed with mixing time, generally increasing. The “equilibrium” p.z.n.c. values were approximately 3.6 and 3.3 for KGa-1 and KGa-2, respectively, while the corresponding p.z.n.p.c. values were about 5.0 and 5.4. The p.z.n.c. results were in good agreement with previous studies, but the values of p.z.n.p.c. were higher than other values reported for specimen kaolinite.

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PECVD Silicon Nitride Passivation on Boron Emitter: The Analysis of Electrostatic Charge on the Interface Properties

Advances in OptoElectronics ◽

10.1155/2010/487406 ◽

2010 ◽

Vol 2010 ◽

pp. 1-8 ◽

Cited By ~ 6

Author(s):

Natalita M. Nursam ◽

Yongling Ren ◽

Klaus J. Weber

Keyword(s):

Charge Density ◽

Substantial Reduction ◽

Chemical Vapour ◽

Surface Recombination ◽

Surface Concentration ◽

Surface Recombination Velocity ◽

Boron Diffusion ◽

Kelvin Probe ◽

Net Charge ◽

Significant Difference

The dependence of surface recombination of boron diffused and undiffused silicon surfaces passivated with a-Si:H on the net charge density is investigated in detail. The films are deposited by plasma-enhanced chemical vapour deposition using a 2.45 GHz microwave remote plasma system. The surface charge density on the samples is varied by depositing charge using a corona discharge chamber. Excess carrier lifetime, capacitance-voltage, and Kelvin probe measurements are combined to determine the surface recombination velocity and emitter saturation current density as a function of net charge density. Our results show that the application of negative charge causes a substantial reduction in the surface recombination of samples with boron diffused emitters, even for high boron surface concentrations of . The significant difference observed in surface recombination between boron diffused and undiffused sample under accumulation implies that the presence of boron diffusion has results in some degradation of the Si-Si interface. Further, (111) oriented surfaces appear more sensitive to the boron surface concentration than (100) oriented surfaces.

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