Beschäftigungswirkungen beim Übergang zu einer alternativen Energiestruktur

"Konfrontiert mit der stetigen Verknappung von Öl und Gas, mit Sicherheits- und Umweltproblemen in Verbindung mit Kohle - und Kern-Energie sowie mit den steigenden Preisen dieser nicht regenerierbaren Brennstoffe, konzentriert sich das Interesse in steigendem Maße auf die Möglichkeiten einer alternativen Energiestruktur und auf die Frage nach den Beschäftigungswirkungen, die sich dabei ergeben würden. Das hier im Gegensatz zu herkömmlichen Projektionen für die USA entwickelte Szenario stellt im Schwerpunkt auf rationelle Energieverwendung sowie direkte und indirekte Nutzung von Sonnenenergie ab. Vorgesehen wird im einzelnen eine bessere Isolation von Privat- und Geschäftsgebäuden sowie Ausstattung mit passiven und aktiven Solarsystemen. Im industriellen Bereich werden energieeffizientere Methoden, wie Kraft-Wärme-Kopplung, Solarkollektoren und mehr Recycling erwartet. Das Transportwesen soll durch leistungsfähigere Kraftfahrzeuge und den verstärkten Einsatz von Massentransportmitteln verbessert werden. Methan- und Alkoholgewinnung aus Biomasse-Abfällen, die Verwendung von Solarzellen sowie wind- und sonnenbetriebene Generatoren sollen weitere Energiepotentiale nutzbar machen. In den USA sind hierfür bis 1990 Investitionen in Höhe von 500 Mrd. $(in Preisen von 1978) erforderlich, ab 1990 jährliche Investitionen in Höhe von 66 Mrd.$, das sind 13% der privaten Bruttoanlageinvestitionen. Die vorgesehenen Maßnahmen zur rationelleren Energieverwendung und Nutzung von regenerierbaren Energiequellen würde bis 1990 in der Gesamtwirtschaft per Saldo zu zusätzlich 2.170.000 Arbeitsplätzen führen. Ein Viertel der Investitionen und Arbeitsplätze entfallen dabei auf die rationelle Energieverwendung, drei Viertel auf die direkte und indirekte Nutzung der Solarenergie, deren Anteil bis 1990 auf 13% steigen könnte. Durch die Maßnahmen könnte 1990 insgesamt, einschließlich Solarenergie, mit 76 quads nicht mehr Energie verbraucht werden als 1977. Der Verbrauch an erschöpfbarer Energie sänke sogar um 15%, der Stromverbrauch um 29%. Damit verbunden würde sich die Zahl der Arbeitsplätze in den brennstoff- und elektrizitätserzeugenden Wirtschaftszweigen (einschließlich Vor- und Zulieferer) um 1.137.000 verringern. Andererseits entstünde durch die Energieeinsparung ein zusätzlich verfügbares Einkommen, das, wenn es für andere Güter und Dienstleistungen ausgegeben wird, zusätzlich 1.870.000 Arbeitsplätze schaffen würde. Insgesamt ergäbe sich also bei diesem Szenario ein Netto-Beschäftigungseffekt von 2.903.000 neuen Arbeitsplätzen. Weitere positive Effekte werden in der dann aufgrund der spezifischen Technologie entstehenden dezentralen Beschäftigungsstruktur gesehen, sowie in dem Umstand, daß die vorgesehenen alternativen Energiegewinnungs- und Verwendungsverfahren arbeitsintensivere Produktionsprozesse erforderlich machten, so daß mit einem tendenziellen Rückgang der Arbeitslosigkeit zu rechnen wäre."regenerative Energie, Beschäftigtenstruktur, Solarenergie, USA

Subtractive renormalization of the NN interaction in chiral effective theory up to next-to-next-to-leading order: S waves

We extend our subtractive-renormalization method in order to evaluate the 1S0 and 3S1-3D1 NN scattering phase shifts up to next-to-next-to-leading order (NNLO) in chiral effective theory. We show that, if energy-dependent contact terms are employed in the NN potential, the 1S0 phase shift can be obtained by carrying out two subtractions on the Lippmann-Schwinger equation. These subtractions use knowledge of the the scattering length and the 1S0 phase shift at a specific energy to eliminate the low-energy constants in the contact interaction from the scattering equation. For the J=1 coupled channel, a similar renormalization can be achieved by three subtractions that employ knowledge of the 3S1 scattering length, the 3S1 phase shift at a specific energy and the 3S1-3D1 generalized scattering length. In both channels a similar method can be applied to a potential with momentum-dependent contact terms, except that in that case one of the subtractions must be replaced by a fit to one piece of experimental data. This method allows the use of arbitrarily high cutoffs in the Lippmann-Schwinger equation. We examine the NNLO S-wave phase shifts for cutoffs as large as 5 GeV and show that the presence of linear energy dependence in the NN potential creates spurious poles in the scattering amplitude. In consequence the results are in conflict with empirical data over appreciable portions of the considered cutoff range. We also identify problems with the use of cutoffs greater than 1 GeV when momentum-dependent contact interactions are employed. These problems are ameliorated, but not eliminated, by the use of spectral-function regularization for the two-pion exchange part of the NN potentialComment: 40 pages, 21 figure

A New Path-Integral Representation of the TT-Matrix in Potential Scattering

We employ the method used by Barbashov and collaborators in Quantum Field Theory to derive a path-integral representation of the $T$-matrix in nonrelativistic potential scattering which is free of functional integration over fictitious variables as was necessary before. The resulting expression serves as a starting point for a variational approximation applied to high-energy scattering from a Gaussian potential. Good agreement with exact partial-wave calculations is found even at large scattering angles. A novel path-integral representation of the scattering length is obtained in the low-energy limit.Comment: 9 pages, 1 figure, Latex with amsmath, amssym; v2: some typos corrected, matches published versio

Four-path interference and uncertainty principle in photodetachment microscopy

We study the quantal motion of electrons emitted by a pointlike monochromatic isotropic source into parallel uniform electric and magnetic fields. The two-path interference pattern in the emerging electron wave due to the electric force is modified by the magnetic lens effect which periodically focuses the beam into narrow filaments along the symmetry axis. There, four classical paths interfere. With increasing electron energy, the current distribution changes from a quantum regime governed by the uncertainty principle, to an intricate spatial pattern that yields to a semiclassical analysis.Comment: submitted to Europhysics Letter

Matter Wave Scattering and Guiding by Atomic Arrays

We investigate the possibility that linear arrays of atoms can guide matter waves, much as fiber optics guide light. We model the atomic line as a quasi-1D array of s wave point scatterers embedded in 2D. Our theoretical study reveals how matter wave guiding arises from the interplay of scattering phenomena with bands and conduction along the array. We discuss the conditions under which a straight or curved array of atoms can guide a beam focused at one end of the array.Comment: Submitted to Phys. Rev.

Electron Entanglement via a Quantum Dot

This Letter presents a method of electron entanglement generation. The system under consideration is a single-level quantum dot with one input and two output leads. The leads are arranged such that the dot is empty, single electron tunneling is suppressed by energy conservation, and two-electron virtual co-tunneling is allowed. This yields a pure, non-local spin-singlet state at the output leads. Coulomb interaction is the nonlinearity essential for entanglement generation, and, in its absence, the singlet state vanishes. This type of electron entanglement is a four-wave mixing process analogous to the photon entanglement generated by a Chi-3 parametric amplifier.Comment: 4 page

The Coulomb Interaction between Pion-Wavepackets: The piplus-piminus Puzzle

The time dependent Schr\"odinger equation for $\pi^+$--$\pi^-$ pairs, which are emitted from the interaction zone in relativistic nuclear collisions, is solved using wavepacket states. It is shown that the Coulomb enhancement in the momentum correlation function of such pairs is smaller than obtained in earlier calculations based on Coulomb distorted plane waves. These results suggest that the experimentally observed positive correlation signal cannot be caused by the Coulomb interaction between pions emitted from the interaction zone. But other processes which involve long-lived resonances and the related extended source dimensions could provide a possible explanation for the observed signal.Comment: 12 pages, LaTeX, 1 figur

Trapping of Projectiles in Fixed Scatterer Calculations

We study multiple scattering off nuclei in the closure approximation. Instead of reducing the dynamics to one particle potential scattering, the scattering amplitude for fixed target configurations is averaged over the target groundstate density via stochastic integration. At low energies a strong coupling limit is found which can not be obtained in a first order optical potential approximation. As its physical explanation, we propose it to be caused by trapping of the projectile. We analyse this phenomenon in mean field and random potential approximations. (PACS: 24.10.-i)Comment: 15 page

A Generative Approach to Poetic Syntax

Poetic syntax has always been of interest to teachers and scholars alike. Up to the present, however, there has been no workable or reliable means for such analysis, and those forms employed thus far have often left much to be desired in the areas of explanation and illustration. This study presents a new approach to syntactic analysis: generative transformation grammar. It presents basic procedures of generative grammar and applies them to two poems: Not to Keep by Robert Frost, and this man\u27s heart\u27 by e.e. cummings. The results of this analysis illustrates stylistic characteristics unique to these authors and shows that generative grammar can be used as a means of syntactic analysis of poetry. Generative grammar is composed of a very rigorous system that allows for a greater degree of objectivity than was possible in the past and also has the advantage of a clearly pictured graphic representation which is ideal for classroom explanation as well as individual study. Taken together, these two advantages seem to make the case that generative analysis of poetic syntax offers more objectivity and more illustrative techniques than previously available

Renormalization in Nonrelativistic Quantum Mechanics

The importance and usefulness of renormalization are emphasized in nonrelativistic quantum mechanics. The momentum space treatment of both two-body bound state and scattering problems involving some potentials singular at the origin exhibits ultraviolet divergence. The use of renormalization techniques in these problems leads to finite converged results for both the exact and perturbative solutions. The renormalization procedure is carried out for the quantum two-body problem in different partial waves for a minimal potential possessing only the threshold behavior and no form factors. The renormalized perturbative and exact solutions for this problem are found to be consistent with each other. The useful role of the renormalization group equations for this problem is also pointed out.Comment: 16 page