Inductive Charge Research Articles

Intramolecular electronic interaction in phosphorus compounds

The intramolecular electronic interaction in a series of phosphorus compounds is considered on the basis of effects operative in these compounds: inductive, dπ-pπ conjugation, and positive charge effect.

Intramolecular electronic interaction in a series of organosilicon compounds

The intramolecular electronic interaction in a series of silicon compounds is considered in terms the inductive, dπ-pπ conjugation, and positive charge effects.

Charge structure and lightning sensitivity in a simulated multicell thunderstorm

A three‐dimensional dynamic cloud model is used to investigate electrification of the full life cycle of an idealized continental multicell storm. Five laboratory‐based parameterizations of noninductive graupel‐ice charge separation are compared. Inductive (i.e., electric field‐dependent) charge separation is tested for rebounding graupel‐droplet collisions. Each noninductive graupel‐ice parameterization is combined with variations in the effectiveness of inductive charging (off, moderate, and strong) and in the minimum ice crystal concentration (10 or 50 L−1). Small atmospheric ion processes such as hydrometeor attachment and point discharge at the ground are treated explicitly. Three of the noninductive schemes readily produced a normal polarity charge structure, consisting of a main negative charge region with an upper main positive charge region and a lower positive charge region. Negative polarity cloud‐to‐ground (CG) flashes occurred when the lower positive charge (LPC) region had sufficient charge density to cause high electric fields. Two of the three also produced one or more +CG flashes. The other two noninductive charging schemes, which are dependent on the graupel rime accretion rate, tended to produce an initially inverted polarity charge structure and +CG flashes. The model results suggest that inductive graupel‐droplet charge separation could play a role in the development of lower charge regions. Noninductive charging, on the other hand, was also found to be capable of producing strong lower charge regions in the tests with a minimum ice crystal concentration of 50 L−1.

Adhesion measurements for electrostatic powder coatings using a vertical drop test rig and LabVIEW software

The total forces holding a layer of electrostatically charged powder onto a metal work piece results from the combination effect of an interfacial electrochemical phenomenon, an inter-particle/particle cohesive force and a bulk electrostatic image attractive force. An attempt has been made to obtain the total integrated effect by subjecting the powder coating to a mechanical impulsive force parallel to the metal substrate. This is a destructive measurement which is obtained by dropping the work piece down a vertical chute which incorporates an inductive charge pick up device to measure the charge of the powder coating during free fall. The sample is brought to rest at the bottom of the chute and dislodged powder is collected in a micro balance incorporated inside a Faraday cage. The exact charge/mass ratio of dislodged powder can be obtained and the technique enables the calibration of the inductive probe. All the measurements are taken with the powder layer before fusing. LabVIEW by National Instruments is a user friendly and powerful graphical development environment used for signal acquisition, measurement analysis, and data presentation. It is a package designed to acquire, analyse and present. Data acquired from the unit under test can be fed through DAQ cards, instruments or PXI systems and connected to a PC running LabVIEW for analysis. With multiple built-in functions and libraries that cover functions such as analysing and processing and also data visualization and report generation, LabVIEW is highly useful in this application.

Crystal Growth and Some Properties of Lead Indium Niobate-Lead Titanate Single Crystals Produced by Solution Bridgman Method

A single crystal about 15 mm in diameter and 10 mm in length of the lead indium niobate-lead titanate, (1-x)Pb(In1/2Nb1/2)O3–xPbTiO3[PIN–PT(1-x/x)] solid solution system near a morphotropic phase boundary was obtained by the solution Bridgman method using PbO–B2O3 flux. X-ray diffraction study reveals that the ingot cut perpendicularly to the cylindrical as-grown PIN–PT(63/37)(the starting composition) single crystal length exhibits the (110) plane of the perovskite phase, and the wafers cut 2 mm and 10 mm from the bottom of the cylindrical PIN–PT single crystal exhibit the rhombohedral phase and tetragonal one at room temperature, respectively. The crystal growth was almost along the [110] direction. The Ti contents x of these wafers cut at 2 mm and at 10 mm were determined by Inductive Charge Plasma (ICP) chemical analysis to be 0.31 and 0.35, respectively. The Ti content of the as-grown PIN–PT(63/37)(the starting composition) single crystal was found to increase with growth away from the nucleation point. For x=0.31, the relative permittivity εr has a peak (37000 at 10 kHz) at the Curie temperature Tc, 300°C and then a shoulder at the ferroelectric rhombohedral to tetragonal phase transition temperature, 120°C with cooling. For x=0.35, the εr has a peak (25000 at 10 kHz) at Tc, 313°C.

Crossover from space-charge-limited to recombination-limited transport in polymer light-emitting diodes

By performing admittance spectroscopy as a function of frequency on polymer light-emitting diodes, inductive and capacitive charge-relaxation processes with different characteristic time scales are separated. The inductive contributions arise from the finite transit time of injected carriers, while the capacitive contributions stem from dielectric redistribution of charge density in the device. The crossover from inductive charge relaxation at low bias to capacitive charge relaxation at high bias marks the transition from space-charge-limited to recombination-limited current flow. This unexpected result shows that, while the individual carrier mobilities are strongly enhanced by the applied field, the recombination mobility remains unaffected.

Growth, Electric and Thermal Properties of Lead Scandium Niobate-Lead Magnesium Niobate-Lead Titanate Ternary Single Crystals

Single crystals of the xPb(Sc1/2Nb1/2)O3–yPb(Mg1/3Nb2/3)O3–zPbTiO3 (PSMNT 100x/100y/100z) ternary system have successfully been grown by a flux method using 71.4 mol% PbO–28.6 mol% B2O3 flux. The crystals were grown in a platinum crucible by mass crystallization achieved by the slow cooling of a 50PbO:20B2O3:30PSMNT 29/34/37 (mol%) molten solution from 1,200°C to 880°C at 1.2°C/h. The resulting two types of crystals, 2–3 mm in length with perovskite structure and 5–7 mm in length with pyrochlore structure, coexist. Inductive charge plasma (ICP) chemical analysis revealed that the composition of the pulverized powder of perovskite crystal is PSMNT 43/17/40, which is slightly different from the charged composition of PSMNT 29/34/37. One of the single crystals near the morphotropic phase boundary (MPB) showed a dielectric constant peak of 200°C. The grown PSMNT crystals show good thermal stability of the perovskite phase with partical decomposition starting at 1128°C and peritectic melting at 1308°C.

Pulsed currents carried by whistlers. V. Detailed new results of magnetic antenna excitation

A low frequency, oblique whistler wave packet is excited from a single current pulse applied to a magnetic loop antenna. The magnetic field is mapped in three dimensions. The dominant angle of radiation is determined by the antenna dimensions, not by the resonance cone. Topological properties of the inductive and space charge electric fields and space charge density confirm an earlier physical model. Transverse currents are dominated by Hall currents, while no net current flows in the parallel direction. Electron-ion collisions damp both the energy and the helicity of the wave packet. Landau damping is negligible. The radiation resistance of the loop is a few tenths of an Ohm for the observed frequency range. The loop injects zero net helicity. Rather, oppositely traveling wave packets carry equal amounts of opposite signed helicity.

On a new approach to the thermonuclear ignition problem and its propulsion potential

If an electron cloud, magnetically confined inside a long solenoid and generated by inductive charge injection, is compressed in the radial direction, its front, expanding in the axial direction, becomes a Lorentz contracted disc consisting of a very intense pulse of ultrarelativistic electrons. In making an impact on a cylindrical thermonuclear target, the energy stored in the disc is converted into magnetic energy, imploding and igniting the target. The very large magnetic fields reached in the implosion greatly enhance thermonuclear burn. Because this ignition concept converts (1) electric energy stored in capacitors into (2) magnetic energy stored in the coil (3) and from there into the electric magnetic and kinetic energy of an ultrarelativistic electron cloud and (4) finally upon impact into magnetic energy, it leads to a focused energy pulse of very high power. Since it only uses energy conversion by electromagnetic means, it has a high efficiency. Because of the high efficiency, both in the conversion of the energy stored for ignition, but also because of the large magnetic fields in the imploded thermonuclear target, it promises to be much more compact than other ignition concepts based on laser or particle beams. Therefore, if technically feasible, the concept should be well suited for propulsion.

Pulsed currents carried by whistlers. IV. Electric fields and radiation excited by an electrode

Electromagnetic properties of current pulses carried by whistler wave packets are obtained from a basic laboratory experiment. While the magnetic field and current density are described in the preceding companion paper (Part III), the present analysis starts with the electric field. The inductive and space charge electric field contributions are separately calculated in Fourier space from the measured magnetic field and Ohm’s law along B0. Inverse Fourier transformation yields the total electric field in space and time, separated into rotational and divergent contributions. The space-charge density in whistler wave packets is obtained. The cross-field tensor conductivity is determined. The frozen-in condition is nearly satisfied, E+ve×B≂0. The dissipation is obtained from Poynting’s theorem. The waves are collisionally damped; Landau damping is negligible. A radiation resistance for the electrode is determined. Analogous to Poynting’s theorem, the transport of helicity is analyzed. Current helicity is generated by a flow of helicity between pulses traveling in opposite directions which carry opposite signs of helicity. Helicity is dissipated by collisions. These observations complete a detailed description of whistler/current pulses which can occur in various laboratory and space plasmas.

Thermonuclear microexplosion ignition by imploding a disk of relativistic electrons

A new ignition concept for thermonuclear reactions is described, in which an electron cloud produced by inductive charge injection and reaching the Brillouin limit, is magnetically compressed inside a long cylindrical solenoid. For sufficiently fast compression, the front of the cloud becomes a relativistically contracted annular disk of high-energy density, which upon impact on a grounded target leads to a cylindrical implosion easily exceeding the power fluxes required for the ignition of thermonuclear microexplosions. Unlike concepts proposed in the past to ignite thermonuclear microexplosions by relativistic electron beams, the energy delivered to the target is not in the form of kinetic particle energy but in the form of an intense electromagnetic pulse.

Pulsed currents carried by whistlers. II. Excitation by biased electrodes

The transport of time-dependent current between electrodes in contact with a large laboratory magnetoplasma is examined experimentally. Single electrodes biased with respect to the chamber wall or pairs of electrically floating electrodes are used to produce pulsed currents (ωci≪2π/Δt≪ωce). The associated magnetic field vector, B(r,t), is measured in space and time, and the total current density is calculated from J(r,t)=∇×B(r,t)/μ0. The current front is found to propagate at a characteristic wave speed, which does not depend on current amplitude or polarity. The transient current spreads across B0 within a conical region, which depends on source geometry and plasma parameters. It is shown by Fourier transforming B(r,t) into B(k,ω) that the transient fields consist of a spectrum of oblique low-frequency whistler waves. In Fourier space, the inductive and space charge electric fields are calculated from Faraday’s law and the assumption that Etot=Eind+Esc along B0 is negligible. Inverse transforming yields E(r,t). The transient wave fields (B,J,E) exhibit multiple induction effects and the formation of space charges. The results are relevant to pulsed Langmuir probes, beams, and antennas as well as moving steady-state magnetic/current sources such as particle collectors on spacecraft and magnetized asteroids (e.g., Gaspra).

Inductive and space charge electric fields in a whistler wave packet.

A low-frequency whistler wave packet is excited with a pulsed magnetic loop antenna in a large laboratory plasma (1 m diam\ifmmode\times\else\texttimes\fi{}2.5 m, ${\mathit{n}}_{\mathit{e}}$=7\ifmmode\times\else\texttimes\fi{}${10}^{11}$ ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}3}$, ${\mathrm{kT}}_{\mathrm{e}}$=1.3 eV, ${\mathit{B}}_{0}$=20 G). Multipoint (${10}^{4}$) measurements of the wave magnetic field, B(r,t), and 4D fast Fourier transformation, B(k,\ensuremath{\omega}), both verify the dispersion of oblique plane whistler modes and permit the calculation of the wave electric field, decomposed into its rotational (inductive) and irrotational (space charge) contributions, E(r,t)=${\mathbf{E}}_{\mathrm{ind}}$+${\mathbf{E}}_{\mathrm{sc}}$. The space charge density, \ensuremath{\rho}(r,t), for a whistler wave is also shown.

Modeling of inductive charge separation in rainshafts with variable vertical electric fields

The inductive dissipation of uniform vertical electric fields in warm clouds is assessed with a parallel‐capacitor model and with raindrops in 20 size classes having diameters between 0.1 and 4 mm. The collision/breakup parameterization of Low and List [1982 a, b] is used together with the inductive charging proposed by Latham and Mason [1962] and confirmed by Canosa and List [this issue]. The selection of collision, breakup, coalescence, and bouncing events is made on the basis of probabilistic considerations. The results are: (1) The original field decays rapidly and sinusoidally at rainfall rates > 2.4 mm h−1. This dissipative effect has not been recognized in earlier warm‐cloud electrification models. It is a consequence of drop interaction experiments that show standard breakup configurations with the large fragments below the separating smaller fragments (disjection) (2) For disjection, electric fields and raindrop charges oscillate sinusoidally in damped fashion, with the period decreasing with increasing rainrate (3) The results for an initial field of −10 kV m−1 can be linearly scaled to any other initial field. (4) In light rain, inductive charging may produce buildup of vertical fields, but this is not sufficient to cause significant electrification. Threshold limits are given for this process to occur.

Molecular structure and crystal packing of five 4-aminophenyl (4-substituted phenyl) sulfones. Correlations between structural distortions, spectroscopic parameters and electronic substituent effects

The crystal structures of five 4-aminophenyl 4-X-phenyl sulfones (X = NO2, CN, F, OCH3, NH2) are reported. The molecules present a relevant degree of charge redistribution where electronic charge transfer mainly occurs from the amino to the sulfonyl group with consequent shortening of C–N and C–S distances and increase of the quinoid character of the phenylene group. The p-aminophenylsulfonyl moiety is characterized by a substantial geometrical constancy in spite of the fact that the p-X-phenyl group is able to modulate the properties of the whole molecule as shown by the strict intercorrelation between the Hammett constant σp of the substituent X on one side and the proton NMR chemical shift of the p-amino group on the other side. The electronic effects of X are transmitted without increasing the quinoid character of the attached phenylene, and change only its S–C distance. This suggests an inductive charge transfer, without resonance components, from X to the SO2 sulfur, whose partial charge can modulate the properties of the terminal aminic group through the almost constant π-delocalization of the p-aminophenylsulfonyl moiety. A detailed analysis of the hydrogen bonds present in the packing of the five crystals has been carried out. It is shown that the hydrogen bond scheme is mainly controlled by p-aminophenylsulfonyl moieties forming linear chains or bidimensional networks of π-resonant hydrogen bonds linking the molecules by means of N–H ⋯ OS interactions. The N ⋯ O distances and the IR frequencies show that these hydrogen bonds are rather weak and similar to those found in p-nitroaniline derivatives.

Inductive charge dispersal in the solvolysis of 3-substituted bicyclo[1.1.1] pentyl bromides

Abstract Solvolysis rates and products of 3-substituted bicyclo[1.1.1]pentyl bromides indicate extremely strong inductive charge dispersal in the ionization to bicyclo[1.1.1]pentyl-1-cations, the precursors of 3-methylenecyclobutanols.

ChemInform Abstract: Polar Effects. Part 14. Inductive Charge Dispersal in Bicyclo[2.2.2]oct‐1‐yl Cations.

AbstractCorrelation of the rate constants for solvolysis of (I)‐(III) in 80% ethanol with the inductive substituent constants leads to the reaction constants p = ‐ 1.54 (‐ 1.12, ‐ 1.22).

Polar Effects. Part 14. Inductive Charge Dispersal in Bicyclo[2.2.2]oct‐1‐yl Cations

AbstractThe rate constants (log k) for solvolysis of 2‐, 3‐, and 4‐substituted bicyclo[2.2.2]octyl p‐nitrobenzenesulfonates 10, 11 and 12, respectively, correlate linearly with the corresponding inductive substituent constants s̀. The formation of the ion pairs 9 is, therefore, controlled by the I effect of neighboring substituents. It follows from the corresponding reaction constants ρ1 of −1.54, −1.12, and −1.22 that inductivity is highest at the positions α to C(1). It is lower and practically equal at the β‐ and γ‐positions. Therefore, charge dispersal is similar to that previously observed in the quinuclidinium ion 7.

ChemInform Abstract: INDUCTIVE CHARGE DISPERSAL IN THE SOLVOLYSIS OF 2‐EXO‐ AND 2‐ENDO‐NORBORNYL TOLUENESULFONATES

Chemischer InformationsdienstVolume 16, Issue 41 Preparative Organic Chemistry ChemInform Abstract: INDUCTIVE CHARGE DISPERSAL IN THE SOLVOLYSIS OF 2-EXO- AND 2-ENDO-NORBORNYL TOLUENESULFONATES F. FUSO, F. FUSOSearch for more papers by this authorC. A. GROB, C. A. GROBSearch for more papers by this authorP. SAWLEWICZ, P. SAWLEWICZSearch for more papers by this authorG.-W. YAO, G.-W. YAOSearch for more papers by this author F. FUSO, F. FUSOSearch for more papers by this authorC. A. GROB, C. A. GROBSearch for more papers by this authorP. SAWLEWICZ, P. SAWLEWICZSearch for more papers by this authorG.-W. YAO, G.-W. YAOSearch for more papers by this author First published: October 15, 1985 https://doi.org/10.1002/chin.198541078AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume16, Issue41October 15, 1985 RelatedInformation

Inductive Charge Dispersal in Quinuclidinium Ions. Polar Effects, Part 13

AbstractInductive charge dispersal to the α‐ β‐ and γ‐positions of the solvated quinuclidinium ion has been examined by comparing the pKa and the derived inductivities ρI of several 2‐ 3‐ and 4‐substituted quinuclidinium perchlorates 4, 5, and 6, respectively. The same inductivity is observed at the practically equidistant β‐ and γ‐positions. It, therefore, appears that polar substituent effects are transmitted directly through the molecule. As expected, inductivity is considerably higher at the α‐positions where through‐bond and direct induction coincide. The fact that the pKa of all three series of salts correlate linearly with each other points to the common nature of these inductive electron displacements.