6 research outputs found
Piezoelectricity: Quantized Charge Transport Driven by Adiabatic Deformations
We study the (zero temperature) quantum piezoelectric response of Harper-like
models with broken inversion symmetry. The charge transport in these models is
related to topological invariants (Chern numbers). We show that there are
arbitrarily small periodic modulations of the atomic positions that lead to
nonzero charge transport for the electrons.Comment: Latex, letter. Replaced version with minor change in style. 1 fi
Review of Coronal Oscillations - An Observer's View
Recent observations show a variety of oscillation modes in the corona. Early
non-imaging observations in radio wavelengths showed a number of fast-period
oscillations in the order of seconds, which have been interpreted as fast
sausage mode oscillations. TRACE observations from 1998 have for the first time
revealed the lateral displacements of fast kink mode oscillations, with periods
of ~3-5 minutes, apparently triggered by nearby flares and destabilizing
filaments. Recently, SUMER discovered with Doppler shift measurements loop
oscillations with longer periods (10-30 minutes) and relatively short damping
times in hot (7 MK) loops, which seem to correspond to longitudinal slow
magnetoacoustic waves. In addition, propagating longitudinal waves have also
been detected with EIT and TRACE in the lowest density scale height of loops
near sunspots. All these new observations seem to confirm the theoretically
predicted oscillation modes and can now be used as a powerful tool for
``coronal seismology'' diagnostic.Comment: 5 Figure
Development of a Web-Based Mass Transfer Processes Laboratory: System Development and Implementation
A web-based environment is utilized as a means to introduce advanced mass transfer processes concepts in environmental engineering and science courses. System development and implementation is presented, including detailed descriptions of the techniques employed to link software written in high level computer languages such as C++ and FORTRAN to an internet-based, user-friendly graphical user interface for both program input and output