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Articles 1 - 9 of 9
Full-Text Articles in Physical Sciences and Mathematics
Electric Field And Plasmadensity Measurements In The Strongly-Driven Daytime Equatorial Electrojet: 1. The Unstablelayer And Gradient Drift Waves, R. F. Pfaff, M. C. Kelley, E. Kudeki, Bela G. Fejer, K. D. Baker
Electric Field And Plasmadensity Measurements In The Strongly-Driven Daytime Equatorial Electrojet: 1. The Unstablelayer And Gradient Drift Waves, R. F. Pfaff, M. C. Kelley, E. Kudeki, Bela G. Fejer, K. D. Baker
Bela G. Fejer
Electric field and plasma density instrumentation on board a sounding rocket launched from Punta Lobos, Peru, detected intense electrostatic waves indicative of plasma instabilities in the daytime equatorial electrojet. Simultaneous measurements taken by the Jicamarca radar showed strong 3-m type 1 electrojet echoes as well as evidence of kilometer scale horizontally propagating waves. The in situ electric field wave spectra displayed three markedly different height regions within the unstable layer: (1) a two-stream region on the topside between 103 and 111 km where the electron current was considered to be strongest, (2) a gradient drift region between 90 and 106.5 …
The Condor Equatorial Electrojetcampaign: Radar Results, E. Kudeki, Bela G. Fejer, D. T. Farley, C. Hanuise
The Condor Equatorial Electrojetcampaign: Radar Results, E. Kudeki, Bela G. Fejer, D. T. Farley, C. Hanuise
Bela G. Fejer
A review of the experimental and theoretical background to the Condor equatorial electrojet campaign is followed by the presentation and discussion of VHF radar interferometer and HF radar backscatter data taken concurrently with two rocket in situ experiments reported in companion papers (Pfaff et al., this issue (a, b). Both experiments were conducted in strongly driven periods with the on-line radar interferometer displaying signatures of what has been interpreted in earlier radar work (Kudeki et al., 1982) as kilometer scale gradient drift waves. Low-frequency density fluctuations detected by in situ rocket sensors confirm the earlier interpretation. VHF radar/rocket data comparisons …
Electric Field And Plasmadensity Measurements In The Strongly-Driven Daytime Equatorial Electrojet: 2. Two-Streamwaves, R. F. Pfaff, M. C. Kelley, E. Kudeki, Bela G. Fejer, K. D. Baker
Electric Field And Plasmadensity Measurements In The Strongly-Driven Daytime Equatorial Electrojet: 2. Two-Streamwaves, R. F. Pfaff, M. C. Kelley, E. Kudeki, Bela G. Fejer, K. D. Baker
Bela G. Fejer
Both primary and secondary two-stream (Farley-Buneman) waves have been detected by in situ electric field and plasma density probes in the strongly driven daytime equatorial electrojet over Peru. Simultaneous Jicamarca radar observations showed strong vertical and oblique 3-m type 1 echoes, also indicative of the two-stream mechanism. The rocket data show the two-stream region on the topside of the unstable layer to be situated between 103 and 111 km where the electron current was the strongest. This region was characterized by broadband plasma oscillations extending past 1 kHz in the rocket frame. Furthermore, above 106.5 km, where the electron density …
On The Height Variation Of The Equatorial F-Region Vertical Plasmadrifts, J. E. Pingree, Bela G. Fejer
On The Height Variation Of The Equatorial F-Region Vertical Plasmadrifts, J. E. Pingree, Bela G. Fejer
Bela G. Fejer
We have used improved incoherent scatter radar measurements at the Jicamarca Radio Observatory to study the height variation of the F region vertical plasma drift velocity (driven by the zonal electric field) during moderately quiet conditions. Preliminary results indicate a nearly linear change of the vertical drift velocity with altitude between 200 and 700 km, but with considerable day-to-day variations in the value of the slope. On the average, the velocity gradients are positive in the late night and morning periods and negative during the afternoon and evening hours. Simultaneous vertical and zonal drift measurements confirm that the measured height …
Higher-Dimensional Self-Consistent Solution With Deformed Internal Spaces, T. -C. Shen, J. Sobczyk
Higher-Dimensional Self-Consistent Solution With Deformed Internal Spaces, T. -C. Shen, J. Sobczyk
T. -C. Shen
We study a system of gravity and free massless scalar fields minimally coupled to gravity in a 7- dimensional background which is a direct product of a 4-dimensional Minkowski space and a 3- dimensional homogeneously deformed three-sphere. Compactification is caused by the vacuum energy of scalar fields. The effective potential as a function of two parameters (scale and deformation) is calculated numerically after dimensional regularization. We find the effective potential decreases rapidly toward negative infinity in both prolate and oblate directions. The classical curvature, however, can balance the quantum effect and yields three extrema. In addition to the round S …
Primary And Secondary Basis Set Superposition Error At The Scf And Mp2 Levels. H3n‐‐Li+ And H2o‐‐Li+, Zdzisław Latajka, Steve Scheiner
Primary And Secondary Basis Set Superposition Error At The Scf And Mp2 Levels. H3n‐‐Li+ And H2o‐‐Li+, Zdzisław Latajka, Steve Scheiner
Steve Scheiner
The primary basis set superposition error (BSSE) results from the artificial lowering of the energy of each subunit of a pair by the presence of ‘‘ghost orbitals’’ of its partner. In addition, these ghost orbitals perturb the one‐electron properties of the molecule, causing a change in the interaction energy, an effect known as secondary BSSE which is not corrected by the counterpoise procedure. The primary and secondary BSSE are calculated for the interactions of NH3 and H2O with Li+, using a variety of different basis sets. It is found that the 2° BSSE can be …
Vibrational Frequencies And Intensities Of H-Bonded Systems. 1:1 And 1:2 Complexes Of Nh3 And Ph3 With Hf, I. J. Kurnig, M. M. Szczesniak, Steve Scheiner
Vibrational Frequencies And Intensities Of H-Bonded Systems. 1:1 And 1:2 Complexes Of Nh3 And Ph3 With Hf, I. J. Kurnig, M. M. Szczesniak, Steve Scheiner
Steve Scheiner
Frequencies and intensities are calculated by ab initio methods for all vibrational modes of the 1:1 H3X–HF and 1:2 H3X–HF–HF complexes (X=N,P). The HF stretching frequencies are subject to red shifts, roughly proportional to the strength of the H bond, and to manyfold increases in intensity. Although the intramolecular frequency shifts within the proton acceptors are relatively modest, the intensities of the NH3 stretches are magnified by several orders of magnitude as a result of H bonding (in contrast to PH3 which exhibits little sensitivity in this regard). …
Simple Scheme For Variable High Power Laser Beam Attenuation, Stephen E. Bialkowski
Simple Scheme For Variable High Power Laser Beam Attenuation, Stephen E. Bialkowski
Stephen E. Bialkowski
A venetian style infrared attenuator placed prior to a pinhole spatial filter results in variable high‐power laser attenuation. This attenuation scheme has a wide dynamic range, results in high‐quality Gaussian beams, does not introduce beam walk‐off error, and is independent of polarization.
Optimal Estimation Of Impulse‐Response Signals Through Digital Innovations And Matched Filtersmoothing, Stephen E. Bialkowski
Optimal Estimation Of Impulse‐Response Signals Through Digital Innovations And Matched Filtersmoothing, Stephen E. Bialkowski
Stephen E. Bialkowski
A real‐time digital filter is described which may be most useful for optimal determination of the magnitude of impulse‐response functions found in pulsed, repetitive experiments of low duty cycle. This filter is based on a matched filter but employs an interference orthogonalization step. This results in a signal magnitude estimate which is independent of coherent interference. The filter updates the signal magnitude estimate upon each repetition of the experimental cycle. Comparisons to signal estimation using gated sampling devices are given.