13,352 research outputs found
Fracture strain of LPCVD polysilicon
A polysilicon bridge-slider structure in which one end of the bridge is fixed and the other is connected to a plate sliding in two flanged guideways, is designed and fabricated to study the strain at fracture of LPCVD polysilicon. In the experiments, a mechanical probe is used to push against the plate end, compressing and forcing the bridge to buckle until it breaks. The distance that the plate needs to be pushed to break the bridge is recorded. Nonlinear beam theory is then used to interpret the results of these axially-loaded-bridge experiments. The measured average fracture strain of as-deposited LPCVD polysilicon is 1.72%. High-temperature annealing of the bridge-sliders at 1000°C for 1 h decreases the average fracture strain to 0.93%
A study of longitudinal oscillations of propellant tanks and wave propagations in feed lines. Part V - Longitudinal oscillation of a propellant-filled flexible oblate spheroidal tank
Analytical method for determining axisymmetric longitudinal mode shapes and frequencies of incompressible and inviscid fluid in pressurized flexible oblate spheroidal propellant tan
Human Blood Cell Sensing with Platinum Black Electroplated Impedance Sensor
AC impedance sensing is an important method for biological cell analysis in flow cytometry. For micro impedance cell sensors, downsizing electrodes increases the double layer impedance of the metal-electrolyte interface, thus leaves no sensing zone in frequency domain and reduces the sensitivity significantly. We proposed using platinum black electroplated electrodes to solve the problem. In this paper, using this technique we demonstrated human blood cell sensing with high signal to noise ratio
A MEMS electrostatic particle transportation system
We demonstrate here an electrostatic MEMS system
capable of transporting particles 5-10ÎĽm in diameter in
air. This system consists of 3-phase electrode arrays
covered by insulators (Figs. 1, 2). Extensive testing of
this system has been done using a variety of insulation
materials (silicon nitride, photoresist, and Teflon),
thickness (0- 12ÎĽm), particle sizes (1-10ÎĽm), particle
materials (metal, glass, polystyrene, spores, etc),
waveforms, frequencies, and voltages. Although
previous literature [1-2] claimed it impractical to
electrostatically transport particles with sizes 5-10ÎĽm
due to complex surface forces, this effort actually
shows it feasible (as high as 90% efficiency) with the
optimal combination of insulation thickness, electrode
geometry, and insulation material. Moreover, we suggest a qualitative theory for our particle transportation system which is consistent with our data and finite-element electrostatic simulations
A Study of Longitudinal Oscillations of Propellant Tanks and Wave Propagations in Feed Lines. Part III - Wave Propagation in an Elastic Pipe Filled with Incompressible Viscous Streaming Fluid
Longitudinal wave propagation in elastic pipe filled with incompressible viscous streaming flui
DIFFERENCE IN RETAIL AND FOODSERVICE SEAFOOD BUYERS IMPRESSION OF AQUACULTURAL PRODUCT
Consumer/Household Economics,
A micro cell lysis device
A new micromachined cell lysis device is developed. It is designed for miniature bio-analysis systems where cell lysing is needed to obtain intracellular materials for further analysis such as DNA identification. It consists of muti-electrode pairs to apply electric fields to cells. We adopt the means of using electric field lysing because it can greatly simplify purification steps for preparation of biological samples, when compared to conventional chemical methods. Yeast, Chinese cabbage, radish cells and E. coli are tested with the device. The lysis of yeast, Chinese cabbage, radish cells is observed by a microscope. The experimental observation suggests E. coli are also lysed by the pulsed electric field. The range of electric field for the lysis is on the order of 1 kV/cm to 10 kV/cm. In addition, for practical reasons, we reduce the voltage required for lysing to less than 10 V by making the electrode gap on the order of microns
A study of longitudinal oscillations of propellant tanks and wave propagations in feed lines. Part 1 - Propagating pressure waves in a fluid-filled cylindrical shell
Theory and equations for propagating pressure waves in liquid filled cylindrical shell
Yang-Mills theory for non-semisimple groups
For semisimple groups, possibly multiplied by U(1)'s, the number of
Yang-Mills gauge fields is equal to the number of generators of the group. In
this paper, it is shown that, for non-semisimple groups, the number of
Yang-Mills fields can be larger. These additional Yang-Mills fields are not
irrelevant because they appear in the gauge transformations of the original
Yang-Mills fields. Such non-semisimple Yang-Mills theories may lead to physical
consequences worth studying. The non-semisimple group with only two generators
that do not commute is studied in detail.Comment: 16 pages, no figures, prepared with ReVTeX
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