Magnetic stochasticity in gyrokinetic simulations of plasma microturbulence

Analysis of the magnetic field structure from electromagnetic simulations of tokamak ion temperature gradient turbulence demonstrates that the magnetic field can be stochastic even at very low plasma pressure. The degree of magnetic stochasticity is quantified by evaluating the magnetic diffusion coefficient. We find that the magnetic stochasticity fails to produce a dramatic increase in the electron heat conductivity because the magnetic diffusion coefficient remains small

Platelet‐Derived Growth Factor Promotes Periodontal Regeneration in Localized Osseous Defects: 36‐Month Extension Results From a Randomized, Controlled, Double‐Masked Clinical Trial

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141092/1/jper0456.pd

Platelet‐Derived Growth Factor Stimulates Bone Fill and Rate of Attachment Level Gain: Results of a Large Multicenter Randomized Controlled Trial

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141430/1/jper2205.pd

Asymptotics and local constancy of characters of p-adic groups

In this paper we study quantitative aspects of trace characters $\Theta_\pi$ of reductive $p$-adic groups when the representation $\pi$ varies. Our approach is based on the local constancy of characters and we survey some other related results. We formulate a conjecture on the behavior of $\Theta_\pi$ relative to the formal degree of $\pi$, which we are able to prove in the case where $\pi$ is a tame supercuspidal. The proof builds on J.-K.~Yu's construction and the structure of Moy-Prasad subgroups.Comment: Proceedings of Simons symposium on the trace formul

The Grizzly, November 16, 1984

College Acquires New Properties • Crime and Punishment: The New System • Officials Seek Return of Missing Air Masks • Editorial: Force Feeding the Student Body • Letters: Campus Sage Defends Lever Pullers; Group Claims Silent Coup • Study Abroad: A Student\u27s Trip to Scotland • Steady GPA Increase for Math and Poli Sci • Shorts: Pops Concert Scheduled; Shyness Workshop; Three Students Receive Award • Gridders Defeat Dickinson, 45-14 • X-Country Runner Earns Trip to Nationals • Swimmin\u27 women....and the Mermen • CPA Urges Students to Consider Optionshttps://digitalcommons.ursinus.edu/grizzlynews/1128/thumbnail.jp

The Grizzly, November 9, 1984

Program Board Attends Activities Conference • Fraternity Sponsors Thanksgiving Food Drive • Smith Addresses Value of Liberal Arts • Editorials: Newspaper Reflects Campus News and Views; Pulling the Big Lever • Letters to the Editor: Mock Election Coverage Questioned; Intervention Policy Must Go • College Bowl Season Underway • Ursinus in a Box • Shorts: Ec. Council Programs; Photo Exhibit in Library; Turkey Trot; UPB Trips Scheduled; Dutch Folk Songs; USGA Report • Bear Booters Win ECA Conference Bid • Runners Second in MAC\u27s • A Student\u27s View of The Training Facility • Mers Shine at Relay Carnival • Middle East Forum Scheduled • Theater Review: A Thurber Carnival • Student Teachers Hard at Work • News of Yesteryear: Judy Collins to Appear in Concert at Ursinushttps://digitalcommons.ursinus.edu/grizzlynews/1127/thumbnail.jp

Strong "quantum" chaos in the global ballooning mode spectrum of three-dimensional plasmas

The spectrum of ideal magnetohydrodynamic (MHD) pressure-driven (ballooning) modes in strongly nonaxisymmetric toroidal systems is difficult to analyze numerically owing to the singular nature of ideal MHD caused by lack of an inherent scale length. In this paper, ideal MHD is regularized by using a $k$-space cutoff, making the ray tracing for the WKB ballooning formalism a chaotic Hamiltonian billiard problem. The minimum width of the toroidal Fourier spectrum needed for resolving toroidally localized ballooning modes with a global eigenvalue code is estimated from the Weyl formula. This phase-space-volume estimation method is applied to two stellarator cases.Comment: 4 pages typeset, including 2 figures. Paper accepted for publication in Phys. Rev. Letter

Validation in Fusion Research: Towards Guidelines and Best Practices

Because experiment/model comparisons in magnetic confinement fusion have not yet satisfied the requirements for validation as understood broadly, a set of approaches to validating mathematical models and numerical algorithms are recommended as good practices. Previously identified procedures, such as verification, qualification, and analysis of error and uncertainty, remain important. However, particular challenges intrinsic to fusion plasmas and physical measurement therein lead to identification of new or less familiar concepts that are also critical in validation. These include the primacy hierarchy, which tracks the integration of measurable quantities, and sensitivity analysis, which assesses how model output is apportioned to different sources of variation. The use of validation metrics for individual measurements is extended to multiple measurements, with provisions for the primacy hierarchy and sensitivity. This composite validation metric is essential for quantitatively evaluating comparisons with experiments. To mount successful and credible validation in magnetic fusion, a new culture of validation is envisaged.Comment: 27 pages, 1 table, 6 figure

The Grizzly, November 9, 1984

Program Board Attends Activities Conference • Fraternity Sponsors Thanksgiving Food Drive • Smith Addresses Value of Liberal Arts • Editorials: Newspaper Reflects Campus News and Views; Pulling the Big Lever • Letters to the Editor: Mock Election Coverage Questioned; Intervention Policy Must Go • College Bowl Season Underway • Ursinus in a Box • Shorts: Ec. Council Programs; Photo Exhibit in Library; Turkey Trot; UPB Trips Scheduled; Dutch Folk Songs; USGA Report • Bear Booters Win ECA Conference Bid • Runners Second in MAC\u27s • A Student\u27s View of The Training Facility • Mers Shine at Relay Carnival • Middle East Forum Scheduled • Theater Review: A Thurber Carnival • Student Teachers Hard at Work • News of Yesteryear: Judy Collins to Appear in Concert at Ursinushttps://digitalcommons.ursinus.edu/grizzlynews/1127/thumbnail.jp

Effects of hydroxyapatite and PDGF concentrations on osteoblast growth in a nanohydroxyapatite-polylactic acid composite for guided tissue regeneration

The technique of guided tissue regeneration (GTR) has evolved over recent years in an attempt to achieve periodontal tissue regeneration by the use of a barrier membrane. However, there are significant limitations in the currently available membranes and overall outcomes may be limited. A degradable composite material was investigated as a potential GTR membrane material. Polylactic acid (PLA) and nanohydroxyapatite (nHA) composite was analysed, its bioactive potential and suitability as a carrier system for growth factors were assessed. The effect of nHA concentrations and the addition of platelet derived growth factor (PDGF) on osteoblast proliferation and differentiation was investigated. The bioactivity was dependent on the nHA concentration in the films, with more apatite deposited on films containing higher nHA content. Osteoblasts proliferated well on samples containing low nHA content and differentiated on films with higher nHA content. The composite films were able to deliver PDGF and cell proliferation increased on samples that were pre absorbed with the growth factor. nHA–PLA composite films are able to deliver active PDGF. In addition the bioactivity and cell differentiation was higher on films containing more nHA. The use of a nHA–PLA composite material containing a high concentration of nHA may be a useful material for GTR membrane as it will not only act as a barrier, but may also be able to enhance bone regeneration by delivery of biologically active molecules