NOS/NGS activities to support development of radio interferometric surveying techniques

National Geodetic Survey activities towards the development of operational geodetic survey systems based on radio interferometry are reviewed. Information about the field procedures, data reduction and analysis, and the results obtained to date is presented

Synchronizing Sequencing Software to a Live Drummer

Copyright 2013 Massachusetts Institute of Technology. MIT allows authors to archive published versions of their articles after an embargo period. The article is available at

Cylindrical, periodic surface lattice — theory, dispersion analysis, and experiment

A two-dimensional surface lattice of cylindrical topology obtained via perturbing the inner surface of a cylinder is considered. Periodic perturbations of the surface lead to observation of high-impedance, dielectric-like media and resonant coupling of surface and non-propagating volume fields. This allows synthesis of tailored-for-purpose "coating" material with dispersion suitable, for instance, to mediate a Cherenkov type interaction. An analytical model of the lattice is discussed and coupled-wave equations are derived. Variations of the lattice dispersive properties with variation of parameters are shown, illustrating the tailoring of the structure's electromagnetic properties. Experimental results are presented showing agreement with the theoretical model

Persistence of artificial sweeteners in a 15-year-old septic system plume

pre-printGroundwater contamination from constituents such as NO3 -, often occurs where multiple sources are present making source identification difficult. This study examines a suite of major ions and trace organic constituents within a well defined septic system plume in southern Ontario, Canada (Long Point site) for their potential use as wastewater tracers. The septic system has been operating for 20 years servicing a large, seasonal-use campground and tritium/helium age dating indicates that the 200 m long monitored section of the plume is about 15 years old. Four parameters are elevated along the entire length of the plume as follows; the mean electrical conductivity value (EC) in the distal plume zone is 926 μS/cm which is 74% of the mean value below the tile bed, Na+ (14.7 33 mg/L) is 43%, an artificial sweetener, acesulfame (12.1 μg/L) is 23% and Cl- (71.5 mg/L) is 137%. EC and Cl- appear to be affected by dispersive dilution with overlying background groundwater that has lower EC but has locally higher Cl- as result of the use of a dust suppressant (CaCl2) in the campground. Na, in addition to advective dilution, could be depleted by weak adsorption. Acesulfame, in addition to the above processes could be influenced by increasing consumer use in recent years. Nonetheless, both Na+ and acesulfame remain elevated throughout the plume by factors of more than 100 and 40 1000 respectively compared to background levels, and are strong indicators of wastewater impact at this site. EC and Cl- are less useful because their contrast with background values is much less (EC) or because other sources are present (Cl-). Nutrients (NO3 -, NH4 +, PO4 3-, K+) and pathogens (E. coli) do not persist in the distal plume zone and are less useful as wastewater indicators here. The artificial sweetener, acesulfame, has persisted at high concentrations in the Long Point plume for at least 15 years (and this timing agrees with tritium/helium-3 dating) and this compound likely occurs at uniquely high concentrations in domestic wastewater. As such, it holds considerable promise as a powerful new tracer of wastewater impact in groundwater

Diffuse Neutron Scattering Study of Relaxor Ferroelectric (1-x)Pb(Zn1/3Nb2/3)O3-xPbTiO3(PZN-xPT)

Diffuse neutron scattering is a valuable tool to obtain information about the size and orientation of the polar nanoregions that are a characteristic feature of relaxor ferroelectrics. In this paper, we present new diffuse scattering results obtained on Pb(Zn1/3Nb2/3)O3 (PZN for short) and (1-x)Pb(Zn1/3Nb2/3)O3-xPbTiO3(PZN-xPT)single crystals (with x=4.5 and 9%), around various Bragg reflections and along three symmetry directions in the [100]-[011] zone. Diffuse scattering is observed around reflections with mixed indices, (100), (011) and (300), and along transverse and diagonal directions only. No diffuse scattering is found in longitudinal scans. The diffuse scattering peaks can be fitted well with a Lorentzian function, from which a correlation length is extracted. The correlation length increases with decreasing temperatures down to the transition at Tc, first following a Curie-Weiss law, then departing from it and becoming flat at very low temperatures. These results are interpreted in terms of three temperature regions: 1) dynamic polarization fluctuations (i.e. with a finite lifetime) at high temperatures, 2) static polarization reorientations (condensation of polar nanoregions) that can still reorient as a unit (relaxor behavior) at intermediate temperatures and 3) orientational freezing of the polar nanoregions with random strain fields in pure PZN or a structural phase transition in PZN-xPT at low temperatures. The addition of PT leads to a broadening of the diffuse scattering along the diagonal ([111]) relative to the transverse ([100]) direction, indicating a change in the orientation of the polar regions. Also, with the addition of PT, the polar nanoregions condense at a higher temperature above Tc.Comment: AIP 6x9 style files, 9 pages, 5 figures, Conference-Fundamental Physics of Ferroelectrics 200

Remarks on the Extended Characteristic Uncertainty Relations

Three remarks concerning the form and the range of validity of the state-extended characteristic uncertainty relations (URs) are presented. A more general definition of the uncertainty matrix for pure and mixed states is suggested. Some new URs are provided.Comment: LaTex, 4 pages, no figure

Uncollected Essays

Foreword by Paul A. Olson • Buzones, an Alternative Etymology • The Manuel des Péchés and an English Episcopal Decree • Correspondence – The Manuel des Péchés • A Note on the Classical Origin of ‘Circumstances’ in the Medieval Confessional • A Study of Certain Aspects of the Cultural Tradition of ‘Handlyng Synne’ • The Cultural Tradition of Handlyng Synne • Marie de France, Lais, Prologue, 13-16 • Cumhthach Labhras an Lonsa • Chaucerian Tragedy • St. Foy among the Thorns • Amors de terra lonhdana • The Subject of the De Amore of Andreas Capellanus • Why the Devil Wears Green • A Further Note on Conjointure • The Book of the Duchess • Chaucer Criticism • “And for my land thus hastow mordred me?” Land Tenure, the Cloth Industry, and the Wife of Bath • Chaucer and the “Commune Profit”: The Manor • The Intellectual, Artistic and Historical Context • Religion and Stylistic History • Simple Signs from Everyday Life in Chaucer • Chaucer and Christian Tradition • The Wife of Bath and Midas • The Probable Date and Purpose of Chaucer’s Troilus • Who Were “The People”? • Chaucer and the Economic and Social Consequences of the Plague • The Probable Date and Purpose of Chaucer’s Knight’s Tale • The Physician’s Comic Tale • Wisdom and “The Manciple’s Tale”: A Chaucerian Comic Interlude ISBN: 978-1-60962-113-1 doi: 10.13014/K23776W6https://digitalcommons.unl.edu/zeabook/1060/thumbnail.jp