Physics Commons^™

The Physical Tourist, A Science Guide For The Traveler, Tom Greenslade

Thomas B. Greenslade, Jr.

Typical travel guides have sections on architecture, art, literature, music and cinema. Rarely are any science-related sites identified. For example, a current travel guide for Germany contains one tidbit on science: Einstein is identified as the most famous citizen of Ulm. By contrast, this travel guide walks a tourist through Berlin and identifies where Max Planck started the quantum revolution, where Einstein lived and gave his early talks on general relativity, and where, across the street, Einstein’s books were burned by the Nazis. Or, if you are walking in Paris, this guide tells you where radioactivity was discovered and where …

The Physical Tourist, Tom Greenslade

Thomas B. Greenslade, Jr.

Typical travel guides have sections on architecture, art, literature, music and cinema. Rarely are any science-related sites identified. For example, a current travel guide for Germany contains one tidbit on science: Einstein is identified as the most famous citizen of Ulm. By contrast, this travel guide walks a tourist through Berlin and identifies where Max Planck started the quantum revolution, where Einstein lived and gave his early talks on general relativity, and where, across the street, Einstein’s books were burned by the Nazis. Or, if you are walking in Paris, this guide tells you where radioactivity was discovered and where …

Characterization Of Physical, Thermal And Spectroscopic Properties Of Biofield Energy Treated P-Phenylenediamine And P-Toluidine, Mahendra Kumar Trivedi, Alice Branton, Dahryn Trivedi, Gopal Nayak, Ragini Singh, Snehasis Jana

Mahendra Kumar Trivedi

Partition-Based Weighted Sum Filters For Image Restoration, Kenneth Barner, Ahmad Sarhan, Russell Hardie

Russell C. Hardie

We develop the concept of partitioning the observation space to build a general class of filters referred to as partition-based weighted sum (PWS) filters. In the general framework, each observation vector is mapped to one of M partitions comprising the observation space, and each partition has an associatedfiltering function. We focus on partitioning the observation space utilizing vector quantization and restrict the filtering function within each partition to be linear. In this formulation, a weighted sum of the observation samples forms the estimate, where the weights are allowed to be unique within eachpartition. The partitions are selected and weights tuned …

1-Butaneboronic Acid Binding To Aeromonas Proteolytica Aminopeptidase:  A Case Of Arrested Development, Carin C. De Paola, Brian Bennett, Richard C. Holz, Dagmar Ringe, Gregory A. Petsko

Richard C. Holz

Hydrolases containing two metal ions connected by a bridging ligand catalyze reactions important in carcinogensis, tissue repair, post-translational modification, control and regulation of biochemical pathways, and protein degradation. The aminopeptidase from Aeromonas proteolytica serves as a paradigm for the study of such bridged bimetallic proteases since its three-dimensional structure is known to very high resolution and its catalytic reaction is amenable to spectroscopic examination. Herein, we report the X-ray crystal structure at 1.9 Å resolution of AAP complexed with 1-butaneboronic acid (BuBA). This structure suggests that this complex represents a snapshot of the proteolytic reaction in an arrested form between …

High Electron Mobility In Free-Standing Gan Substrates, A. Saxler, David Look, Said Elhamri, J. Sizelove, D. Cull, William Mitchel, Michael Callahan, David Bliss, Lionel Bouthillette, Sheng-Qi Wang, C. Sung, Seong-Ju Park, K. Lee

Said Elhamri

High peak electron mobilities were observed in free-standing c-plane GaN substrates. Two layers, a low mobility degenerate layer and a high mobility bulk layer, were present in these samples. The carrier concentrations and mobilities for the layers were extracted using two methods: 1) magnetic field dependent Hall effect analysis and 2) a simple two carrier model with the assumption that one of the layers is degenerate. In addition, measurements were performed after etching away the degenerate layer. The mobility of the bulk layer is found to peak at nearly 8000 cm2/Vs at 60K using the magnetic field dependent Hall effect …

Deep Centers In Semi-Insulating Current Topics In Solid State Physics Fe-Doped Native Gan Substrates Grown By Hydride Vapour Phase Epitaxy, Z-Q. Fang, Bruce Claflin, David Look, Said Elhamri, H. Smith, William Mitchel, D. Hanser, E. Preble, K. Evans

Said Elhamri

Electrical properties, Fe concentration, and deep centers in semi-insulating Fe-doped GaN substrates grown by hydride vapor phase epitaxy (HVPE) were characterized by temperature-dependent Hall-effect measurements, secondary ion mass spectroscopy, and thermally stimulated current (TSC) spectroscopy, Five adjacent samples from a low-[Fe] wafer displayed very high resistivity, dominated by a center at 0,94 eV. At least six traps were observed in the samples by TSC, with trap (0.56-0.60 eV) being dominant. A metastable trap A, at similar to 0.82 eV appeared after white-light illumination at 300 K-A sample from a high-[Fe] wafer displayed a lower resistivity, dominated by a center at …

Video Feature — Banned Books And The Stuart Rose Collection, Robert Brecha, Una Cadegan, John Inglis, Paul Morman

Robert J. Brecha

A faculty panel discussion in two sessions:

Session 1:
The Index: Una Cadegan (history) looks at the current scholarship on the Index of Forbidden Books.
Galileo: Robert Brecha (physics) highlights the banning of Galileo and observational science.

Session 2:
Thomas Aquinas: John Inglis (philosophy) speaks on the banning of Thomas Aquinas's Summa Theologica, the most important book in Catholic intellectual tradition.
Descartes and the Index of Forbidden Books: Paul Morman (history, Distinguished Service Professor) highlights the book by Descartes that he was not allowed to study while a student at UD in the 1960s.