Physics Commons^™

Gathering Leadership Momentum Across Great Distances: Creating An Online Community Of Practice, Erin L. Davis, Danielle Theiss-White

Erin Davis

At the 2007 Mountain Plains Library Association Leadership (MPLA) Institute, held in New Mexico, USA, eight academic librarians formed an online multi-state, multigenerational community of practice. MPLA is a twelve-state library association within the United States. Using Google Groups™, the members formed an online environment called the MPLA Community of Practice for continuing development of the leadership skills presented at the Institute. These early-career librarians represent diverse educational backgrounds and work in libraries serving varied populations with differing disciplinary emphases.

The group meets monthly with each member preparing and facilitating online discussions, complete with personal assessments, topical readings, and questions. …

Elliptical Orbit Node Passage Time, Eric Addison

Eric Addison

The node passage time is calculated in order to gain an understanding of the kind of velocities and time scales will be involved in BEMRI simulations during close encounters with the SMBH. The result is generalized to produce a function of time with respect to theta, t(θ).

Living Anionic Polymerization Using A Microfluidic Reactor, Kazunori Iida, Thomas Q. Chastek, Kathryn L. Beers, Kevin Cavicchi, Jaehun Chun, Fasolka J. Michael

Kevin Cavicchi

Living anionic polymerizations were conducted within aluminum-polyimide microfluidic devices. Polymerizations of styrene in cyclohexane were carried out at various conditions, including elevated temperature (60 degrees C) and high monomer concentration (42%, by volume). The reactions were safely maintained at a controlled temperature at all points in the reactor. Conducting these reactions in a batch reactor results in uncontrolled heat generation with potentially dangerous rises in pressure. Moreover, the microfluidic nature of these devices allows for flexible 2D designing of the flow channel. Four flow designs were examined (straight, periodically pinched, obtuse zigzag, and acute zigzag channels). The ability to use …

Alamethicin In Lipid Bilayers: Combined Use Of X-Ray Scattering And Md Simulations, Jianjun Pan, D. Peter Tieleman, John F. Nagle, Norbert Kučerka, Prof. Stephanie Tristram-Nagle Ph.D.

Prof. Stephanie Tristram-Nagle Ph.D.

We study fully hydrated bilayers of two di-monounsaturated phospholipids diC18:1PC (DOPC) and diC22:1PC with varying amounts of alamethicin (Alm). We combine the use of X-ray diffuse scattering and molecular dynamics simulations to determine the orientation of alamethicin in model lipids. Comparison of the experimental and simulated form factors shows that Alm helices are inserted transmembrane at high humidity and high concentrations, in agreement with earlier results. The X-ray scattering data and the MD simulations agree that membrane thickness changes very little up to 1/10 Alm/ DOPC. In contrast, the X-ray data indicate that the thicker diC22:1PC membrane thins with added …

Patent Citation Networks Revisited: Signs Of A Twenty-First Century Change, Katherine J. Strandburg, Gabor Csardi, Laszlo Zalanyi, Jan Tobochnik, Peter Erdi

Katherine J. Strandburg

This Article reports an empirical study of the network composed of patent “nodes” and citation “links” between them. It builds on an earlier study, in which we argued that trends in the growth of the patent citation network provide evidence that the explosive growth in patenting in the late twentieth century was due at least in part to the issuance of increasingly trivial patents. We defined a measure of patent stratification based on comparative probability of citation; an increase in this measure suggests that the USPTO is issuing patents of comparatively less technological significance. Provocatively, we found that stratification increased …

Appearance Of A Fractional Stokes-Einstein Relation In Water And A Structural Interpretation Of Its Onset, L. Xu, F. Mallamace, Z. Yan, Francis W. Starr, S. V. Buldyrev, H. E. Stanley

Francis Starr

The Stokes–Einstein relation has long been regarded as one of the hallmarks of transport in liquids. It predicts that the self-diffusion constant D is proportional to (τ/T)−1, where τ is the structural relaxation time and T is the temperature. Here, we present experimental data on water confirming that, below a crossover temperature T× ≈ 290 K, the Stokes– Einstein relation is replaced by a ‘fractional’ Stokes–Einstein relation D ∼ (τ/T)−ζ with ζ ≈ 3/5 (refs 1–6). We interpret the microscopic origin of this crossover by analysing the OH- stretch region of the Fourier transform infrared spectrum over a temperature range …

Review Of Biocd Physics And Technology, David D. Nolte

David D Nolte

Spinning biodisks have advantages that make them attractive for specialized biochip applications. The two main classes of spinning biodisks are microfluidic disks and bio-optical compact disks BioCD. Microfluidic biodisks take advantage of noninertial pumping for lab-on-a-chip devices using noninertial valves and switches under centrifugal and Coriolis forces to distribute fluids about the disks. BioCDs use spinning-disk interferometry, under the condition of common-path phase quadrature, to perform interferometric label-free detection of molecular recognition and binding. The optical detection of bound molecules on a disk is facilitated by rapid spinning that enables high-speed repetitive sampling to eliminate 1/ f noise through common-mode …

Problems Of Local Fractional Definite Integral Of The One-Variable Non-Differentiable Function, Yang Xiao-Jun

Xiao-Jun Yang

It is proposed that local fractional calculas introduced by Kolwankar and Gangal is extended by the concept of Jumarie’s fractional calculus and local fractional definite integral is redefined. The properties and the theorems of local fractional calculus are discussed in this paper.

Multilayered Structures In The Ionosphere F2 Region And Impulse-Like Increase Of The Nightglow Red 630 Nm Line Intensity As A Result Of Influence Of Shear Excited Atmospheric Vortical Perturbations, G. G. Didebulidze, Levan Lomidze, N. B. Gudadze, M. Todua

Levan Lomidze

It is shown that the formation of multilayered structures in the midlatitude ionosphere F 2 layer can be caused by atmospheric vortical perturbation (shear wave) evolving in the meridional wind with linear zonal shear and can be accompanied by an impulse-like increase (with duration about 1–3 h) in the red 630 nm line total nightglow intensity. The shear wave can produce an enhancement of the northward wind (or decrease in the southward one), which can cause a downward motion of the F 2 layer peak height resulting in the impulse-like increase in the red line intensity. An important increase in …