Saint Anselm College

About: Saint Anselm College is a education organization based out in Manchester, New Hampshire, United States. It is known for research contribution in the topics: Politics & Nurse education. The organization has 255 authors who have published 522 publications receiving 7222 citations.

Quantum Relativity of Subsystems

Abstract: One of the most basic notions in physics is the partitioning of a system into subsystems, and the study of correlations among its parts. In this work, we explore these notions in the context of quantum reference frame (QRF) covariance, in which this partitioning is subject to a symmetry constraint. We demonstrate that different reference frame perspectives induce different sets of subsystem observable algebras, which leads to a gauge-invariant, frame-dependent notion of subsystems and entanglement. We further demonstrate that subalgebras which commute before imposing the symmetry constraint can translate into non-commuting algebras in a given QRF perspective after symmetry imposition. Such a QRF perspective does not inherit the distinction between subsystems in terms of the corresponding tensor factorizability of the kinematical Hilbert space and observable algebra. Since the condition for this to occur is contingent on the choice of QRF, the notion of subsystem locality is frame-dependent.

Prototype holographic atmospheric scanner for environmental remote sensing

Abstract: A ground-based atmospheric lidar system that utilizes a holographic optical telescope and scanner has been developed and successfully operated to obtain atmospheric backscatter profiles The Prototype Holographic Atmospheric Scanner for Environmental Remote Sensing is built around a volume phase reflection holographic optical element (HOE) This single optical element both directs and collimates the outgoing laser beam as well as collects, focuses, and filters the atmospheric laser backscatter while offering significant weight savings over existing telescope mirror technology Conical scanning is accomplished as the HOE rotates on a turntable sweeping the 12 mrad field of view around a 42° cone During this technology demonstration, atmospheric aerosol and cloud return signals have been received in both stationary and scanning modes The success of this program has led to the further development of this technology for integration into airborne and eventually satellite Earth-observing scanning lidar telescopes

Differentiation of Hypocaust and Floor Tiles at Coriglia, Castel Viscardo (Umbria, Italy) Using Principal Component Analysis (PCA) and Portable X-ray Fluorescence (XRF) Spectrometry

Abstract: Portable X-ray Fluorescence (XRF) spectrometry was used to collect elemental data for in situ hypocaust tiles and floors at an archaeological excavation site near Orvieto, Italy. Data obtained from 2009 to 2011 using three different XRF instruments are compared. Both quantitative results and spectral data were utilized for graphical and chemometric evaluation of the samples' elemental compositions. Despite the different instrumental conditions, changes in data collection protocols, and various data evaluation procedures used with each instrument, conclusions about the archaeological relationships among the tiles remained the same across the three-year study. Utilization of fused data did provide some improvements in differentiation of the materials but at the cost of significantly increased analysis times. The robustness of portable XRF instruments for differentiation of in situ archaeological samples is clearly demonstrated.

Non-Clausius heat transfer: The method of the nonstationary Langevin equation.

Abstract: Compared to other formulations of the second law of thermodynamics, the Clausius statement that heat does not spontaneously flow from cold to hot concerns a system in nonequilibrium states, and in that respect is more ambitious but also more ambiguous. We discuss two scenarios when the Clausius statement in its plain form does not hold. First, for ergodic systems, the energy transfer may be consistent with the statement on a coarse-grained timescale, but be anomalously directed during time intervals shorter than the thermalization time. In particular, when an initially colder system is brought in contact to a hotter bath, the internal energy of the former increases with time in a long run but not monotonically. Second, the heat transfer may not respect the Clausius statement on any timescale in nonergodic systems due to the formation of localized vibrational modes. We illustrate the two scenarios with a familiar model of an isotope atom attached to a semi-infinite harmonic atomic chain. Technically, the discussion is based on a Langevin equation for the isotope, using the initial condition when the isotope and chain are initially prepared in uncorrelated canonical states under the constraint that the boundary atom between the isotope and chain is initially fixed and later released. In such setting, the noise in the Langevin equation is nonstationary, and the fluctuation-dissipation relation has a nonstandard form.