Unequal Charge Research Articles

On the Electrostatic Interaction across a Salt Solution between Two Bodies Bearing Unequal Charges

We consider two parallel planar charged surfaces bearing unequal surface charge densities interacting across a region in ionic equilibrium with a neutral salt solution. Combining rules are derived appropriate for interactions across distances of separation greater than the characteristic Debye length. When ions are excluded from the regions behind the interacting surfaces there can be repulsion between charged surfaces of opposite sign; but surfaces bearing charges of the same sign never attract one another. Also, surfaces bearing electrostatic potential of like sign can attract.

A Droplet Generator with Electronic Control of Size, Production Rate, and Charge

A droplet generator has been developed which can produce small droplets one at a time, in groups with adjustable time intervals between droplets or in a continuous stream with controllable production rates of up to 100 per second for the smallest size. Size, charge, and time of production as well as horizontal position at the time the droplet is made may be changed electronically from droplet to droplet. Droplets are produced with nine adjustable and overlapping size ranges covering radii from 4 to 130μ. An application is described where one droplet generator is used in a cloud physics study of collisions between pairs of droplets of unequal size and charge.

Characterization of Platinum Electrodes in H2‐Saturated Sulfuric Acid Solution: I . Transient Conditions

A single cycle of anodic‐cathodic constant current pulses (1–3 A/cm2) were applied to a normal hydrogen Pt electrode. Following anodic charging to between 0.4 and 1.75V, the total faradaic and nonfaradaic cathodic charge to the H2 evolution plateau was equal to the net anodic charge. The distribution of total faradaic charge into hydrogen and oxygen processes in each half‐cycle, as based on a geometric separation of charging regions, showed that anodic charging gave a much better resolution of each of these processes. The irreversible reduction of occurred in two separate regions of unequal charge content. The two regions represent a complex reduction of where the O is held with different bonding energies rather than a sequence of two one electron steps. The amount of H deposited up to the negative limiting potential plateau where H2 evolution occurred is numerically equal to the amount of H that is associated with Pt at the normal H+/H2 equilibrium.

Implications of Unequal Charge Asymmetry inKL0→π±e∓νandKL0→π±μ∓ν

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Metallic Interfaces. II. Influence of the Exchange-Correlation and Lattice Potentials

An electron-gas model of a metallic interface is constructed by joining two semi-infinite half-planes of unequal positive charge and adding electrons until a charge-neutral system is achieved. Our earlier treatment of this model is extended in several directions. The exchange-and-correlation effective one-electron potential, formerly taken in the "dipole approximation" to equal its bulk value in each material, is calculated using the local-density approximation. In the case where the low-density material has the smaller separation energy, the size of its depletion region and the height of the barrier potential are increased. In the case where the low-density material has the larger separation energy, the use of the local-density exchange-and-correlation potential scarcely alters the results obtained using the dipole approximation. A modified self-consistent free-electron model of a metal-intrinsic semiconductor junction adequately accounts for several features of the experimental data concerning the dependence of the barrier height on the components and method of fabrication of the junction. A primary effect of energy gaps associated with the periodic potential is the introduction of a long-range contribution to the junction potential in the semiconductor. An examination of (solvable) one-dimensional models suggests that if the semiconductor energy gaps are small relative to the metal bandwidth, then the modified free-electron model correctly describes the modification of the short-range (\ensuremath{\sim}1-5 \AA{}) dipole layers at the metal-semiconductor interface. In this case the modified free-electron model adequately determines the barrier height at the interface, although it never describes the details of the space-charge potential in the semiconductor.

Electronic Interaction in the Free-Electron Network Model for Conjugated Systems. III. Spectra of Hydrocarbons Other Than Even Alternants

The effects on spectral calculations of including interaction between the ground and lower excited states are investigated by the free-electron model for some hydrocarbons in which such interaction should occur in principle, viz., phenanthrene, perinaphthenylium cation, and azulene. The resultant lowering of the ground state energy is less than 150 cm—1 when the ground and excited states have equal charge densities. For azulene, with unequal charge densities, the interaction is about 4000 cm—1, and the agreement with experiment for the two lower singlet levels is considerably improved. The free-electron calculations for the nonalternant ions C5H5; and C7H7+ are also reported.

Two-Center Heteronuclear Hybrid Coulomb-Exchange Integrals

The method introduced by Sklar and Lyddane, and used by Parr and Crawford, to evaluate two-center hybrid Coulomb-exchange integrals involving atoms with equal effective nuclear charges has been extended to include the case of unequal effective nuclear charges. Formulas for all thirty nonvanishing integrals of this type involving 2s and 2p Slater atomic orbitals (assuming that the 2s and 2p orbitals on the same atom have the same screening) are given in a form convenient for numerical calculations. These formulas are valid for both the homonuclear and the heteronuclear cases. The method here given has the advantage that all the integrals are expressed in terms of natural logarithms, exponentials, and exponential integrals, adequate tables of which are readily available. Exact numerical values obtained by this method for thirty hybrids involving carbon and oxygen atomic orbitals in CO2 are given. These exact values have been used as a check on the validity of an approximation previously employed for these integrals.

Simple Kinetic Theory of Ionic Exchange for Ions of Unequal Charge

Simple Kinetic Theory of Ionic Exchange for Ions of Unequal Charge

Nuclear Fission

This article pertains to the most newly-discovered and most sensational mode of transmutation, in which the entry of a neutron into a massive atom-nucleus brings about an internal explosion in which the nucleus is “fissured” or divided into two fragments which share the total mass and charge between them in nearly equal proportions, (In all other modes of transmutation except those affecting the very lightest elements, the division is into fragments of very unequal mass and charge.) The conversion of rest-mass into kinetic energy, or (as is more commonly said) the release of energy, is unprecedented in scale. A multitude of radioactive bodies, many hitherto unknown, is formed; and there is spontaneous emission of fresh neutrons in great quantities, possibly sufficient to convert the process once initiated into a self-perpetuating one under realizable conditions.

The conditions for identical orbits in the case of two charged particles of unequal mass and unequal charge

The conditions for identical orbits in the case of two charged particles of unequal mass and unequal charge

Electrical separation between identical solid surfaces

When one insulating solid is rubbed along and perpendicular to an identical one they acquire charges, -ve and +ve, respectively. Continued rubbing so affects the surfaces of rubber and rubbed that their properties change, with reversal of sign to +ve and -ve respectively. The effect 2 is permanent, unless the surfaces be restored by heat treatment. Oblique impact of two identical solids generates on them unequal charges. The net charge is, in general, -ve.