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Mathematics, Physics, and Computer Science Faculty Articles and Research

1997

Articles 1 - 7 of 7

Full-Text Articles in Physical Sciences and Mathematics

Module Embedding, Atanas Radenski Dec 1997

Module Embedding, Atanas Radenski

Mathematics, Physics, and Computer Science Faculty Articles and Research

This paper proposes a code reuse mechanism called module embedding that enables the building of new modules from existing ones through inheritance, overriding of procedures, and overriding of types; the paper also describes an implementation scheme for this mechanism. Module embedding is beneficial when modules and classes are used in combination and need to be extended together, or when modules are more appropriate medium than classes.

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Multiwavelength Blazar Studies, Menas Kafatos Jan 1997

Multiwavelength Blazar Studies, Menas Kafatos

Mathematics, Physics, and Computer Science Faculty Articles and Research

The present report concerns the following projects 'High energy emission from hot accretion disks from active galactic nuclei'; 'OSSE spectral timing and monitoring observations of Cygnus X- 1'; 'OSSE observations of blazars'; and 'Search for correlated time variations of bright EGRET blazars'. The most favored model for the central engine inAGNs is the supermassive black hole hypothesis (Rees 1978). The observed luminosities range from approx. 10 logical and 44-45 erg /s for objects such as Mk 421 and Seyferts to as much as approx. 10logical and 47 for powerful QSOs such as 3C 273 and 3C 279, a large fraction …

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Multifrequency Studies, Menas Kafatos Jan 1997

Multifrequency Studies, Menas Kafatos

Mathematics, Physics, and Computer Science Faculty Articles and Research

The present report concerns the following projects 'Multifrequency observations of the BL Lacertae object MK 421"; "EUVE and multifrequency observations of the quasars 3C 273 and 3C 279"; "EUVE observations of the symbiotic star RAquarii"; and "Morphology of the local HI void and ionization of He in the local ISM". The common theme of the above projects is UV observations and analysis of a wide range of astrophysical classes or objects, from the diffuse interstellar medium, to symbiotic stars (R Aqr), to active galactic nuclei (AGNs). Understanding the local (primarily neutral hydrogen or HI) interstellar medium is of great importance …

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Hartogs' Phenomenon For Polyregular Functions And Projective Dimension Of Related Modules Over A Polynomial Ring, W. W. Adams, P. Loustaunau, V. P. Palamadov, Daniele C. Struppa Jan 1997

Hartogs' Phenomenon For Polyregular Functions And Projective Dimension Of Related Modules Over A Polynomial Ring, W. W. Adams, P. Loustaunau, V. P. Palamadov, Daniele C. Struppa

Mathematics, Physics, and Computer Science Faculty Articles and Research

In this paper we prove that the projective dimension of Mn = R^4/(An) is 2n -1, where R is the ring of polynomials in 4n variables with complex coefficients and (An) is the module generated by the columns of a 4x4n matrix which arises as the Fourier transform of the matrix of differential operators associated with the regularity condition for a function of n quaternionic variables. As a corollary we show that the sheaf R of regular functions has flabby dimension 2n -1, and we prove a cohomology vanishing theorem for open sets in the space Hn of quaternions. We …

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Voltage Responses To Optical Pulses Of Unbiased Normal And Superconducting Samples, D. Van Vechten, K. S. Wood, G. G. Fritz, J. S. Horitz, G. M. Daly, J. B. Thrasher, D. M. Photiadis, J. Ding, J. F. Pinto, M. G. Blamire, G. Burnell, A. L. Gyulamiryan, V. H. Vartanyan, R. B. Akopyan, Armen Gulian Jan 1997

Voltage Responses To Optical Pulses Of Unbiased Normal And Superconducting Samples, D. Van Vechten, K. S. Wood, G. G. Fritz, J. S. Horitz, G. M. Daly, J. B. Thrasher, D. M. Photiadis, J. Ding, J. F. Pinto, M. G. Blamire, G. Burnell, A. L. Gyulamiryan, V. H. Vartanyan, R. B. Akopyan, Armen Gulian

Mathematics, Physics, and Computer Science Faculty Articles and Research

The direct transformation of the energy of an incident high-energy photon into a measurable potential difference within an absorbing metal is investigated. Experimental evidence is presented that the effect arises from the inherent energy dependence of the electronic density of states, rather than from a simple temperature excursion. The similarities between the results on Al and YBa2Cu3O7 samples indicate that the effect is universal in nature. We assert it may be used as the basis of a fast, energy resolving, individual photon detector for the ultraviolet radiation and x-rays.

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Contemporaneous Iue, Euve, And High-Energy Observations Of 3c 273, E. Ramos, Menas Kafatos, A. Fruscione, F. C. Bruhweiler, I. M. Mchardy, R. C. Hartman, L. G. Titarchuk, C. Von Montigny Jan 1997

Contemporaneous Iue, Euve, And High-Energy Observations Of 3c 273, E. Ramos, Menas Kafatos, A. Fruscione, F. C. Bruhweiler, I. M. Mchardy, R. C. Hartman, L. G. Titarchuk, C. Von Montigny

Mathematics, Physics, and Computer Science Faculty Articles and Research

We present the results of our 1994 January and 1995 January observations of the quasar 3C 273 obtained with the International Ultraviolet Explorer (IUE) and the Extreme-Ultraviolet Explorer (EUV E). These observations were part of a large multiwavelength campaign to observe 3C 273 from radio through γ-rays. Our 1995 January photometric observations with the EUV E Lexan/B Deep Survey (DS) instrument indicate strong evidence for variability, at a 99% confidence level, during the 12 day observing period. We have utilized ROSAT PSPC soft X-ray power-law models to correlate with EUV E count rates. Besides variations in the normalization level between …

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Lateral Shock Of The R Aquarii Jet, J. M. Hollis, J. A. Pedelty, Menas Kafatos Jan 1997

Lateral Shock Of The R Aquarii Jet, J. M. Hollis, J. A. Pedelty, Menas Kafatos

Mathematics, Physics, and Computer Science Faculty Articles and Research

The R Aqr jet was observed with the VLA B-configuration at two epochs separated by ~13.2 yr. Comparison of the resulting 6 cm continuum images show that the radio jet has undergone a lateral counterclockwise rotation of ~6-12 on the plane of the sky. The model of jet parcels on independent trajectories is difficult to reconcile with these observations and leads us to consider a path-oriented jet (i.e., younger parcels follow the same path as older parcels). Comparison of the most recent radio image with a nearly contemporaneous HST /FOC ultraviolet image at ~2330 A suggests that the ultraviolet emission …

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