Modeling Thickness Shear Mode Quartz Sensors for Increased Downhole Pressure & Temperature Applications
G.R. Kirikera, W. Patton, and S.M. Behr
Geophysical Research Company LLC, Tulsa, OK, USA
Numerous sensors based on various sensing principles are used to measure pressures and temperatures in wellbores. Of all these sensors, piezoelectric quartz is the most preferred means of sensing pressure and temperature and is probably the only sensor to meet stringent downhole measurement requirements. The sensor consists of a quartz piezoelectric resonator hermetically sealed between two ...
Characterization of an AlGaN/GaN Electrostatically Actuated Cantilever Using the Finite Element Method
N. DeRoller, M. Qazi, J. Liu, and G. Koley
University of South Carolina, Columbia, SC, USA
AlGaN/GaN heterostructures are unique because the 2DEG at the interface is created by the difference in polarization properties of the AlGaN and the GaN layers; not due to intentional doping. In this work, a 3D model of an electrostatically actuated micro cantilever has been developed using COMSOL for characterization using the finite element method (FEM). The microcantilever has AlGaN/GaN HFET ...
S. Khushrushahi, and M. Zahn
Massachusetts Institute of Technology, Cambridge, MA, USA
A fully filled sphere of ferrofluid has constant demagnetizing factors in all three Cartesian directions such that when subjected to a uniform external rotating magnetic field the internal field is also uniform, and ultrasound measurements give no observable flow. Non-uniform magnetic fields or a non-uniform distribution of susceptibility are necessary conditions for ferrofluid spin-up flows in ...
University of Miami, Miami, FL, USA
Insulin released by the beta-cells of pancreatic islets is the main regulator of glucose homeostasis, hence, insulin secretion models are of considerable interest for many possible applications. Building on our previous oxygen consumption and cell viability model for avascular islets of Langerhans, we developed an exploratory insulin secretion model that couples the hormone production rate to ...
G.D. Cole, M. Aspelmeyer, and I. Wilson-Rae
University of Vienna, Vienna, Austria
Technical University Munich, Munich, Germany
Micro-and nanoscale mechanical resonators have recently emerged as ubiquitous devices for use in advanced technological applications, for example in mobile communications and inertial sensors, and as novel tools for fundamental scientific endeavors. We report a significant advancement towards understanding and controlling support-induced losses through the demonstration of an efficient numerical ...
Y. Sheng, S. Rancourt-Grenier, P. Bareil, P. Duval, M. Wei, A. Chiou, and J. Bai
University Laval, Quebec, QC, Canada
National Yang-Ming University, Taipei, Taiwan
A dual-trap optical tweezers is used for deforming the red blood cell (RBC) in suspension and studying its elasticity. The 3D deformation of the cells was computed with the elastic membrane theory. The calculated deformation can fit to experimental data resulting in cell’s elasticity coefficient. The static approach is valid only for small deformation (5-10%). For a large deformation such as ...
C.J. Forster, and M.K. Smith
Georgia Institute of Technology, Atlanta, GA, USA
The use of an acoustic field to control the boiling process has the potential to increase the overall rate of heat transfer and delay the critical transition to film boiling. This system is being investigated through the development of a model of a single boiling bubble near a flat, heated, horizontal surface in the presence of an acoustic field. The dynamics of the bubble interface is ...
Y. Beauregard, M. Gobian, and F. Garisto
University of Western Ontario, London, ON, Canada
Nuclear Waste Management Organization, Toronto, ON, Canada
In the Canadian concept for a deep geological repository for used nuclear fuel, the used fuel bundles are placed in containers consisting of an inner steel vessel surrounded by a copper shell. The filled containers are placed in excavated tunnels or boreholes and surrounded by a compacted bentonite clay buffer material. In the event of container failure, the rate of migration of radionuclides ...
Pryor Knowledge Systems Inc., Bloomfield Hills, MI, USA
This paper presents one approach to the modeling of an abrupt junction PIN photodiode light sensor using COMSOL Multiphysics software and the incorporated SPICE® capability. The current model is built using the capabilities of SPICE in COMSOL Multiphysics 4.0. This model demonstrates the use of SPICE and the AC/DC Module to build a conduction current, rather than an electrostatic, model. This ...
S. Kargar, and D. Bardot
University of Alabama, Huntsville, AL, USA
In this paper we compare the results from a bending cantilever beam experiment with the theoretical values and COMSOL finite element simulation results. In the experiment a simple cantilever beam with a hole is loaded at the end. Measurements are recorded by four strain gauges mounted on the beam, three near the hole and one at a location where the nominal stress is equivalent to that of a ...