2,806 research outputs found
Riccati parameter modes from Newtonian free damping motion by supersymmetry
We determine the class of damped modes \tilde{y} which are related to the
common free damping modes y by supersymmetry. They are obtained by employing
the factorization of Newton's differential equation of motion for the free
damped oscillator by means of the general solution of the corresponding Riccati
equation together with Witten's method of constructing the supersymmetric
partner operator. This procedure leads to one-parameter families of (transient)
modes for each of the three types of free damping, corresponding to a
particular type of %time-dependent angular frequency. %time-dependent,
antirestoring acceleration (adding up to the usual Hooke restoring
acceleration) of the form a(t)=\frac{2\gamma ^2}{(\gamma t+1)^{2}}\tilde{y},
where \gamma is the family parameter that has been chosen as the inverse of the
Riccati integration constant. In supersymmetric terms, they represent all those
one Riccati parameter damping modes having the same Newtonian free damping
partner modeComment: 6 pages, twocolumn, 6 figures, only first 3 publishe
Pauli's Theorem and Quantum Canonical Pairs: The Consistency Of a Bounded, Self-Adjoint Time Operator Canonically Conjugate to a Hamiltonian with Non-empty Point Spectrum
In single Hilbert space, Pauli's well-known theorem implies that the
existence of a self-adjoint time operator canonically conjugate to a given
Hamiltonian signifies that the time operator and the Hamiltonian possess
completely continuous spectra spanning the entire real line. Thus the
conclusion that there exists no self-adjoint time operator conjugate to a
semibounded or discrete Hamiltonian despite some well-known illustrative
counterexamples. In this paper we evaluate Pauli's theorem against the single
Hilbert space formulation of quantum mechanics, and consequently show the
consistency of assuming a bounded, self-adjoint time operator canonically
conjugate to a Hamiltonian with an unbounded, or semibounded, or finite point
spectrum. We point out Pauli's implicit assumptions and show that they are not
consistent in a single Hilbert space. We demonstrate our analysis by giving two
explicit examples. Moreover, we clarify issues sorrounding the different
solutions to the canonical commutation relations, and, consequently, expand the
class of acceptable canonical pairs beyond the solutions required by Pauli's
theorem.Comment: contains corrections to minor typographical errors of the published
versio
Translated Literature in Your Library: The Mildred L Batchelder Award
Translated books represent a unique bridge between cultures for young readers. This article discusses recent trends and practical applications for award-winning literature that has been translated into English and published in the United States. Winner and honour titles earning the Mildred L Batchelder Award for their publishers often include European languages of origins and settings. Despite this homogeneity, the books represent a quality option as a way to diversify a library collection for English-speaking patrons, particularly young adults, and to enhance teaching lessons with the integration of this global literature
Curation in Translation: Promoting Global Citizenship Through Literature
As curators of the school library collection, librarians ensure the resources they select are of high quality and that they meet students\u27 social needs, including diverse perspectives representative of our world and supportive of global citizenship skills and dispositions. The Mildred L. Batchelder Award given to English translations published in the United States is an option for librarians seeking such cultural diversity for their collections. Using the United Nations\u27 Declaration of the Rights of the Child (1959), the research identifies the strong potential these titles hold for engaging youth and promoting global citizenship
A shallow water ferrous-hulled shipwreck reveals a distinct microbial community.
This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY).Shipwrecks act as artificial reefs and provide a solid surface in aquatic systems for many different forms of life to attach to, especially microbial communities, making them a hotspot of biogeochemical cycling. Depending on the microbial community and surrounding environment, they may either contribute to the wreck’s preservation or deterioration. Even within a single wreck, preservation and deterioration processes may vary, suggesting that the microbial community may also vary. This study aimed to identify the differences through widespread sampling of the microbial communities associated with the Pappy Lane shipwreck (NC shipwreck site #PAS0001), a shallow water ferrous-hulled shipwreck in Pamlico Sound, North Carolina to determine if there are differences across the wreck as well as from its surrounding environment. Loose shipwreck debris, drilled shipcores, surrounding sediment, and seawater samples were collected from the Pappy Lane shipwreck to characterize the microbial communities on and around the shipwreck. Results indicated that the shipwreck samples were more similar to each other than the surrounding sediment and aquatic environments suggesting they have made a specialized niche associated with the shipwreck. There were differences between the microbial community across the shipwreck, including between visibly corroded and non-corroded shipwreck debris pieces. Relative abundance estimates for neutrophilic iron-oxidizing bacteria (FeOB), an organism that may contribute to deterioration through biocorrosion, revealed they are present across the shipwreck and at highest abundance on the samples containing visible corrosion products. Zetaproteobacteria, a known class of marine iron-oxidizers, were also found in higher abundance on shipwreck samples with visible corrosion. A novel Zetaproteobacteria strain, Mariprofundus ferrooxydans O1, was isolated from one of the shipwreck pieces and its genome analyzed to elucidate the functional potential of the organism. In addition to iron oxidation pathways, the isolate has the genomic potential to perform carbon fixation in both high and low oxygen environments, as well as perform nitrogen fixation, contributing to the overall biogeochemical cycling of nutrients and metals in the shipwreck ecosystem. By understanding the microbial communities associated with shallow water ferrous-hulled shipwrecks, better management strategies and preservation plans can be put into place to preserve these artificial reefs and non-renewable cultural resources.ECU Open Access Publishing Support Fun
Telecommunications systems design techniques handbook
Handbook presents design and analysis of tracking, telemetry, and command functions utilized in these systems with particular emphasis on deep-space telecommunications. Antenna requirements are also discussed. Handbook provides number of tables outlining various performance criteria. Block diagrams and performance charts are also presented
Wind and air pollution control study of Yerba Buena Center
For McCue - Boone - Tomsick.CER71-72JEC-FHC-ACH-JAG15.June 1972.Includes bibliographical references
Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 parsecs: The Northern Sample I
We have embarked on a project, under the aegis of the Nearby Stars (NStars)/
Space Interferometry Mission Preparatory Science Program to obtain spectra,
spectral types, and, where feasible, basic physical parameters for the 3600
dwarf and giant stars earlier than M0 within 40 parsecs of the sun. In this
paper we report on the results of this project for the first 664 stars in the
northern hemisphere. These results include precise, homogeneous spectral types,
basic physical parameters (including the effective temperature, surface gravity
and the overall metallicity, [M/H]) and measures of the chromospheric activity
of our program stars. Observed and derived data presented in this paper are
also available on the project's website at http://stellar.phys.appstate.edu/
The effect of udder irrigation and milking interval on milk secretion
Publication authorized February 6, 1936.Digitized 2007 AES.Includes bibliographical references (pages 38-39)
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