Switch on, switch off: stiction in nanoelectromechanical switches

We present a theoretical investigation of stiction in nanoscale electromechanical contact switches. We develop a mathematical model to describe the deflection of a cantilever beam in response to both electrostatic and van der Waals forces. Particular focus is given to the question of whether adhesive van der Waals forces cause the cantilever to remain in the ‘ON’ state even when the electrostatic forces are removed. In contrast to previous studies, our theory accounts for deflections with large slopes (i.e. geometrically nonlinear). We solve the resulting equations numerically to study how a cantilever beam adheres to a rigid electrode: transitions between free, ‘pinned’ and ‘clamped’ states are shown to be discontinuous and to exhibit significant hysteresis. Our findings are compared to previous results from linearized models and the implications for nanoelectromechanical cantilever switch design are discussed

The Distribution of Natural Enemies of the Corn Leaf Aphid (Homoptera: Aphdidae) on Field Corn

(excerpt) The corn leaf aphid (CLA), Rhopalosiphum maidis (Fitch), is found on field corn in the midwest Cnited States each year. Except for infrequent and scattered outbreaks, CLA populations remain at low levels. Injury to corn occurs during tasseling (Snelling et aL 1941) and is caused by CLAs which are the progeny of colonizers that arrived 2-3 weeks earlier when the corn was in the whorl stage (Bryson 1934, Falter 1963)

Liquid rocket metal tanks and tank components

Significant guidelines are presented for the successful design of aerospace tanks and tank components, such as expulsion devices, standpipes, and baffles. The state of the art is reviewed, and the design criteria are presented along with recommended practices. Design monographs are listed

Information on the structure of the a1 from tau decay

The decay $\tau\to \pi\pi\pi\nu$ is analysed using different methods to account for the resonance structure, which is usually ascribed to the a1. One scenario is based on the recently developed techniques to generate axial-vector resonances dynamically, whereas in a second calculation the a1 is introduced as an explicit resonance. We investigate the influence of different assumptions on the result. In the molecule scenario the spectral function is described surprisingly well by adjusting only one free parameter. This result can be systematically improved by adding higher order corrections to the iterated Weinberg-Tomozawa interaction. Treating the a1 as an explicit resonance on the other hand leads to peculiar properties

Physical State of the Deep Interior of the CoRoT-7b Exoplanet

The present study takes the CoRoT-7b exoplanet as an analogue for massive terrestrial planets to investigate conditions, under which intrinsic magnetic fields could be sustained in liquid cores. We examine the effect of depth-dependent transport parameters (e.g., activation volume of mantle rock) on a planet's thermal structure and the related heat flux across the core mantle boundary. For terrestrial planets more massive than the Earth, our calculations suggest that a substantial part of the lowermost mantle is in a sluggish convective regime, primarily due to pressure effects on viscosity. Hence, we find substantially higher core temperatures than previously reported from parameterized convection models. We also discuss the effect of melting point depression in the presence of impurities (e.g., sulfur) in iron-rich cores and compare corresponding melting relations to the calculated thermal structure. Since impurity effects become less important at the elevated pressure and temperature conditions prevalent in the deep interior of CoRoT-7b, iron-rich cores are likely solid, implying that a self-sustained magnetic field would be absent.Comment: 4 pages, 3 figures. IAU 276 Proceeding

Nurses Alumni Association Bulletin, Fall 2000

2000 - 2001 Meeting Date Calendar 2001 Annual Luncheon & Meeting Notice 2000 Fall Social Officers and Committee Chairs Bulletin Publication Committee The President\u27s Message Treasurer\u27s Report Resume of Minutes Alumni Office News Committee Reports Nurses Relief Trust Fund Clara Melville - Adele Lewis Scholarship Fund Satellite Report - Harrisburg Satellite The Fall Luncheon Nominating Alumni Bulletin Development News about our Graduates Presentation on Leadership -Tribute to Janet C. Hindson Thank You Patient Assimilators Third Janet C. Hindson Award Janet C. Hindson Award Qualifications Pinning Ceremony Jeff HOPE Keepsakes Memoirs Happy Birthday 50th Anniversary Class Luncheon Photos Kodak Moment In Memoriam, Names of Deceased Graduates Class News Scholarship Fund Application Certification Reimbursement Application Relief Fund Application Pins, Transcripts, Class Address List, Change of Address Forms Notes Campus Map List of Hotel