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Search Results: 1 - 10 of 17739 matches for " Andrew Walton "
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A Golfer's Resource: Huron Hills Golf Course, Ann Arbor, Michigan
Andrew Walton
Solstice : Electronic Journal of Geography and Mathematics , 2004,
Abstract: The link to the fulltext on a current website is given below. Should that link fail to work, please go to this persistent URL and download the associated file for this issue. http://deepblue.lib.umich.edu/handle/2027.42/58219While you are there, take a look around and see if there are other issues and documents that are related to your interests!
Dermatology training and career options in the U.K. for Indian graduates
Walton Shernaz,Finlay Andrew
Indian Journal of Dermatology, Venereology and Leprology , 2004,
Characterization of Reinforced Carbon Composites with Full Field Measurements: Long Gauge Length Compressive Apparatus  [PDF]
Mathieu Colin de Verdiere, Alexandros A. Skordos, Andrew Walton
Open Journal of Composite Materials (OJCM) , 2013, DOI: 10.4236/ojcm.2013.31002

A new compressive testing apparatus is developed and used in this research. It has long gauge length to allow digital image correlation monitoring and anti buckling guides to prevent buckling. It allows the optical recording of strains and displacements. The novel setup is used to study the compressive response of tufted and untufted Carbon non crimp fabric composites with full field measurements. Experimental results show that the specimens are not bending in the apparatus under compression. Results also show reduced strain concentrations and a large strain field that provides a good environment for material compressive stiffness characterization. The test proves particularly successful for bias direction layup of [+45/-45] for which large damage mechanism occurs. However for [0/90] specimens a scatter in compressive ultimate strength was noticed which is due to the difficulty to prepare specimens with best minute accurate geometry. The compressive apparatus has shown to be a good alternative to existing setups and to provide significantly more information as well as having the possibility to be used in dynamics with a drop tower.

Key results from an XMM-Newton and Chandra study of a new sample of extreme ULXs from the 2XMM catalogue
Andrew D. Sutton,Timothy P. Roberts,Dominic J. Walton
Physics , 2010, DOI: 10.1002/asna.201011500
Abstract: We present highlights from a study of a sample of 10 extreme-luminosity candidate ultraluminous X-ray sources (L_X > 5 x 10^(40) erg sec^(-1)), all at distances < 100 Mpc, identified from a cross-correlation of the RC3 catalogue of galaxies with the 2XMM catalogue. Five of the sample have also been observed by Chandra. Of the 10 sources, seven reside in the disc or arms of spiral galaxies, and the remaining three are close to large elliptical galaxies. Unlike many less luminous ultraluminous X-ray sources, temporal variability is observed on short (ks) and long (year) timescales for most sources in our sample. Long term spectral variability is also evident in some sources. In one case, we use archival Chandra data to demonstrate that a hyperluminous X-ray source candidate identified by XMM-Newton is actually resolved into multiple point sources at high spatial resolution, but note that the other candidates remain unresolved under Chandra's intense scrutiny.
Composite Photon Theory versus Elementary Photon Theory  [PDF]
Walton A. Perkins
Journal of Modern Physics (JMP) , 2014, DOI: 10.4236/jmp.2014.518205
Abstract: The purpose of this paper is to show that the composite photon theory measures up well against the Standard Model’s elementary photon theory. This is done by comparing the two theories, area by area. Although the predictions of quantum electrodynamics are in excellent agreement with experiment (as in the anomalous magnetic moment of the electron), there are some problems, such as the difficulty in describing the electromagnetic field with the four-component vector potential because the photon has only two polarization states. In most areas the two theories give similar results, so it is impossible to rule out the composite photon theory. Pryce’s arguments in 1938 against a composite photon theory are shown to be invalid or irrelevant. Recently, it has been realized that in the composite theory the antiphoton does not interact with matter because it is formed of a neutrino and an antineutrino with the wrong helicity. This leads to experimental tests that can determine which theory is correct.
An efficient and practical entry to 2-amido-dienes and 3-amido-trienes from allenamides through stereoselective 1,3-hydrogen shifts
Ryuji Hayashi,John B. Feltenberger,Andrew G. Lohse,Mary C. Walton
Beilstein Journal of Organic Chemistry , 2011, DOI: 10.3762/bjoc.7.53
Abstract: Preparations of de novo acyclic 2-amido-dienes and 3-amido-trienes through 1,3-hydrogen shifts from allenamides are described. These 1,3-hydrogen shifts could be achieved thermally or they could be promoted by the use of Br nsted acids. Under either condition, these processes are highly regioselective in favour of the α-position, and highly stereoselective in favour of the E-configuration. In addition, 6π-electron electrocyclic ring-closure could be carried out with 3-amido-trienes to afford cyclic 2-amido-dienes, and such electrocyclic ring-closure could be rendered in tandem with the 1,3-hydrogen shift.
Open and Arthroscopic Surgical Anatomy of the Ankle
Rachel M. Frank,Andrew R. Hsu,Christopher E. Gross,David M. Walton,Simon Lee
Anatomy Research International , 2013, DOI: 10.1155/2013/182650
Abstract: Ankle-related complaints are among the most commonly encountered problems for musculoskeletal clinicians. Ankle pathology is widely variable, including, but not limited to, fractures, deformity, infection, oncologic diseases, neuromuscular conditions, and arthritis. While nonoperative management with activity modification, bracing and/or shoe modifications, and medications is usually indicated as first line of treatment, surgical intervention may become necessary. A thorough understanding of the complex anatomy and biomechanics of the ankle, and in particular, the potential neurovascular structures that may be encountered, is important to reduce complications and obtain good surgical outcomes. The purpose of this review is to discuss the most common open and arthroscopic exposures to the ankle with a focus on surgically relevant anatomy for each approach. 1. Introduction Symptoms and complaints regarding the ankle are some of the most commonly encountered problems seen by musculoskeletal care providers. Ankle injuries encompass a broad array of pathology including trauma, deformity, reconstruction, and sports medicine. For nontraumatic injuries, physicians typically provide nonoperative treatment modalities to start including activity modification, rest, immobilization, bracing, orthotics, nonsteroidal anti-inflammatory medications, intra-articular injections, and physical therapy. When patient symptoms worsen and begin to negatively affect quality of living, surgical intervention often becomes necessary for definitive management. Patients with traumatic injuries, including fractures and/or dislocations, often require immediate surgical intervention. Regardless of the specific surgical technique performed, these procedures all require adequate visualization of the ankle pathology to be performed correctly. A thorough understanding of the anatomy about the ankle joint, including the osseous, muscular, ligamentous, tendinous, and neurovascular structures, is critical to perform safe and effective ankle surgery. Open surgical exposures allow complete visualization of the tibiotalar articular surface and are the most commonly employed surgical approaches to the ankle. In recent years, less invasive ankle techniques including miniopen approaches and ankle arthroscopy have become more commonly used. The purpose of this review is to discuss the most common open and arthroscopic exposures used in the surgical treatment of ankle pathology with a focus on surgically relevant anatomy. 2. General Overview The ankle joint is comprised of three bones including the
A collaborative theoretical and experimental study of the structure and electronic excitation spectrum of the BAr and B(Ar)2 complexes
Millard H. Alexander,Andrew Walton,Moonbong Yang,Xin Yang,Eunsook Hwang,Paul J. Dagdigian
Physics , 1997, DOI: 10.1063/1.473621
Abstract: We report the investigation of the 3s <- 2p transition in the BAr2 cluster. In a supersonic expansion of B atoms entrained in Ar, at high beam source backing pressures we observe several features in the fluorescence excitation spectrum which cannot be assigned to the BAr diatom. Using BAr(X, B) potential energy curves which reproduce our experimental observations on this molecule and an Ar-Ar interaction potential, we employ a pairwise additive model, along with variational and diffusion Monte-Carlo treatments of the nuclear motion, to determine the lowest vibrational state of the BAr2 cluster. A subsequent simulation of the fluorescence excitation spectrum reproduces nearly quantitatively the strongest feature in our experimental spectrum not assignable to BAr. Because of the barrier in the BAr(B 2Sigma+) potential energy curve, the 3s <- 2p transition in the BAr2 cluster is predicted to have an asymmetric profile, as is found experimentally.
Suzaku Observation of the Black Hole Candidate MAXI J1836-194 in a Hard/Intermediate Spectral State
Rubens C. Reis,Jon M. Miller,Mark T. Reynolds,Andrew C. Fabian,Dominic J. Walton
Physics , 2011, DOI: 10.1088/0004-637X/751/1/34
Abstract: We report on a Suzaku observation of the newly discovered X-ray binary MAXI J1836-194. The source is found to be in the hard/intermediate spectral state and displays a clear and strong relativistically broadened iron emission line. We fit the spectra with a variety of phenomenological, as well as physically motivated disk reflection models, and find that the breadth and strength of the iron line is always characteristic of emission within a few gravitational radii around a black hole. This result is independent of the continuum used and strongly points toward the central object in MAXI J1836-194 being a stellar mass black hole rotating with a spin of $a=0.88\pm0.03$ (90% confidence). We discuss this result in the context of spectral state definitions, physical changes (or lack thereof) in the accretion disk and on the potential importance of the accretion disk corona in state transitions.
The most extreme ultraluminous X-ray sources: evidence for intermediate-mass black holes?
Andrew D. Sutton,Timothy P. Roberts,Dominic J. Walton,Jeanette C. Gladstone,Amy E. Scott
Physics , 2012, DOI: 10.1111/j.1365-2966.2012.20944.x
Abstract: We present the results from an X-ray and optical study of a new sample of eight extreme luminosity ultraluminous X-ray source (ULX) candidates, which were selected as the brightest ULXs (with L_X > 5x10^40 erg/s) located within 100 Mpc identified in a cross correlation of the 2XMM-DR1 and RC3 catalogues. These objects are so luminous that they are difficult to describe with current models of super-Eddington accretion onto all but the most massive stellar remnants; hence they are amongst the most plausible candidates to host larger, intermediate-mass black holes (IMBHs). Two objects are luminous enough in at least one observation to be classed as hyperluminous X-ray source (HLX) candidates, including one persistent HLX in an S0 galaxy that (at 3x10^41 erg/s) is the second most luminous HLX yet detected. The remaining seven sources are located in spiral galaxies, and several appear to be closely associated with regions of star formation as is common for many less luminous ULXs. However, the X-ray characteristics of these extreme ULXs appear to diverge from the less luminous objects. They are typically harder, possessing absorbed power-law continuum spectra with photon indexes ~ 1.7, and are potentially more variable on short timescales, with data consistent with ~ 10-20 per cent rms variability on timescales of 0.2-2 ks. These properties appear consistent with the sub-Eddington hard state, which given the observed luminosities of these objects suggests the presence of IMBHs with masses in the range 10^3-10^4 M_Sun. As such, this strengthens the case for these brightest ULXs as good candidates for the eventual conclusive detection of the highly elusive IMBHs. However, we caution that a combination of the highest plausible super-Eddington accretion rates and the largest permitted stellar black hole remnants cannot be ruled out without future, improved observations.
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