928 research outputs found

    User's guide to computer programs JET 5A and CIVM-JET 5B to calculate the large elastic-plastic dynamically-induced deformations of multilayer partial and/or complete structural rings

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    These structural ring deflections lie essentially in one plane and, hence, are called two-dimensional (2-d). The structural rings may be complete or partial; the former may be regarded as representing a fragment containment ring while the latter may be viewed as a 2-d fragment-deflector structure. These two types of rings may be either free or supported in various ways (pinned-fixed, locally clamped, elastic-foundation supported, mounting-bracket supported, etc.). The initial geometry of each ring may be circular or arbitrarily curved; uniform-thickness or variable-thickness rings may be analyzed. Strain-hardening and strain-rate effects of initially-isotropic material are taken into account. An approximate analysis utilizing kinetic energy and momentum conservation relations is used to predict the after-impact velocities of each fragment and of the impact-affected region of the ring; this procedure is termed the collision-imparted velocity method (CIVM) and is used in the CIVM-JET 5 B program. This imparted-velocity information is used in conjunction with a finite-element structural response computation code to predict the transient, large-deflection, elastic-plastic responses of the ring. Similarly, the equations of motion of each fragment are solved in small steps in time. Provisions are made in the CIVM-JET 5B code to analyze structural ring response to impact attack by from 1 to 3 fragments, each with its own size, mass, translational velocity components, and rotational velocity. The effects of friction between each fragment and the impacted ring are included

    Feral Goats and Sheep

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    Sheep and goats are among the earliest animals domesticated by mankind (Zeder 2009). Both goats and sheep may have made better candidates for domestication than other animals like deer because they follow a single dominant leader, the herdsman (Geist 1971). They now have a nearly ubiquitous worldwide distribution, and they are among the most abundant of all commensal animals. However, they have also become some of the most widespread invasive feral mammals, particularly on the 100 or more islands throughout the world where they have been introduced, causing severe damage to island ecosystems, in some cases for hundreds of years (Rudge 1984; Chynoweth 2013). Problems caused by feral goats and sheep are a subset of the larger problem of domestic livestock and natural systems. Feral goats are perhaps more widespread than feral sheep because goats have not been as highly modified by the process of domestication (Francis 2015). The Bezoar ibex (Capra aegagrus) is the most likely ancestor of domestic goats (C. hircus) from both genetic and paleontological evidence (Pidancier et al. 2006). The domestication process started at least 10,000 years ago in highlands of western Iran, beginning with the selective harvesting of subadult males and the transition from hunting to herding of the species (Zeder and Hesse 2000). Multiple independent domestication events may have occurred or domestication may have incorporated multiple ancestral lineages (Pidancier et al. 2006). Traits selected during domestication include behavior, dairy, meat, skins, pelage color, mohair, cashmere, horns, pathogen resistance, and even intestines for catgut. Selection for reduced body size may have been related to the ability to better survive in hot and arid environments (Zeder 2009). A profound reduction in horn size occurred after humans began to control breeding, particularly in males, possibly associated with the absence of selective pressures for large horns used in mate competition (Zeder 2009)

    Integrated waveguides and deterministically positioned nitrogen vacancy centers in diamond created by femtosecond laser writing

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    Diamond's nitrogen vacancy (NV) center is an optically active defect with long spin coherence times, showing great potential for both efficient nanoscale magnetometry and quantum information processing schemes. Recently, both the formation of buried 3D optical waveguides and high quality single NVs in diamond were demonstrated using the versatile femtosecond laser-writing technique. However, until now, combining these technologies has been an outstanding challenge. In this work, we fabricate laser written photonic waveguides in quantum grade diamond which are aligned to within micron resolution to single laser-written NVs, enabling an integrated platform providing deterministically positioned waveguide-coupled NVs. This fabrication technology opens the way towards on-chip optical routing of single photons between NVs and optically integrated spin-based sensing

    The Ursinus Weekly, April 22, 1940

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    Speakers urge more humor, courtesy and Christian living at all-Ursinus conference • Governor names Mr. Helfferich to Pa. educ. council • Next forum to present Dr. Everett R. Clinchy • Women to hold hobby conference, Wednesday • F.D.R. wins straw vote at Harrisburg conclave • Daniel Reed to do monologues on Spoon River Anthology • Ursinus is represented by three at TKA convention • Barnard upholds Amer. govt. for basic pol. science class • Historical encyclopedia contains articles by Carter • Pres. McClure will address Girard College student body • Fireside chats analyze Christianity in college • Co-eds rush preparation for medieval May pageant: The King\u27s daughters • Registrar Sheeder addresses Pennsburg School assembly • I.R.C. will sponsor mock trial of Hitler • Club hears talk in French • German Club holds quiz • Physician talks to pre-meds. on causes of eye diseases • Team eyes weather as busy program appears • Jingmen down Lehigh in season opener, 2-0 • Seven girl courtsters to be honored Wed. • Callow thinks job is to form impressions • Jayvees hopeful for beginner with Perkiomen on Wednesday • Twelve aspirants report for tennis; to meet Mules Wed. • Cricket season to start with game at Princeton, Saturday • Cliff Calvert to coach baseball and football for Merchantville • Jing Johnson\u27s career includes coaching at Bucknell and Lehigh • Preceptresses addressed by ex-dean of women at Whittier • Alspach names John Wise head of class day committee • Seven from Ursinus attend collegiate chemistry meeting • Meistersingers close season; group attends opera Aida • Pre-meds arrange for trip to visit centers of medicine • Dr. White injured • Allen to speak at English Clubhttps://digitalcommons.ursinus.edu/weekly/1841/thumbnail.jp

    Coupling a superconducting quantum circuit to a phononic crystal defect cavity

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    Connecting nanoscale mechanical resonators to microwave quantum circuits opens new avenues for storing, processing, and transmitting quantum information. In this work, we couple a phononic crystal cavity to a tunable superconducting quantum circuit. By fabricating a one-dimensional periodic pattern in a thin film of lithium niobate and introducing a defect in this artificial lattice, we localize a 6 gigahertz acoustic resonance to a wavelength-scale volume of less than one cubic micron. The strong piezoelectricity of lithium niobate efficiently couples the localized vibrations to the electric field of a widely tunable high-impedance Josephson junction array resonator. We measure a direct phonon-photon coupling rate g/2π≈1.6 MHzg/2\pi \approx 1.6 \, \mathrm{MHz} and a mechanical quality factor Qm≈3×104Q_\mathrm{m} \approx 3 \times 10^4 leading to a cooperativity C∼4C\sim 4 when the two modes are tuned into resonance. Our work has direct application to engineering hybrid quantum systems for microwave-to-optical conversion as well as emerging architectures for quantum information processing.Comment: 9 pages, 7 figure
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