@article {315, title = {Microfluidic gas-flow profiling using remote-detection NMR}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {102}, year = {2005}, note = {P Natl Acad Sci USA977NZTimes Cited:41Cited References Count:26}, month = {Oct 18}, pages = {14960-14963}, abstract = {

We have used nuclear magnetic resonance (NMR) to obtain spatially and temporally resolved profiles of gas flow in microfluidic devices. Remote detection of the NMR signal both overcomes the sensitivity limitation of NMR and enables time-of-flight measurement in addition to spatially resolved imaging. Thus, detailed insight is gained into the effects of flow, diffusion, and mixing in specific geometries. The ability for noninvasive measurement of microfluidic flow, without the introduction of foreign tracer particles, is unique to this approach and is important for the design and operation of microfluidic devices. Although here we demonstrate an application to gas flow, extension to liquids, which have higher density, is implicit.

}, keywords = {mri}, isbn = {0027-8424}, doi = {Doi 10.1073/Pnas.0507566102}, url = {://WOS:000232811800006}, author = {Hilty, C. and McDonnell, E. E. and Granwehr, J. and Pierce, K. L. and Han, S. I. and Pines, A.} } @article {319, title = {Time-of-flight flow imaging using NMR remote detection}, journal = {Physical Review Letters}, volume = {95}, year = {2005}, note = {Phys Rev Lett955SGTimes Cited:35Cited References Count:29}, month = {Aug 12}, abstract = {

A time-of-flight imaging technique is introduced to visualize fluid flow and dispersion through porous media using NMR. As the fluid flows through a sample, the nuclear spin magnetization is modulated by rf pulses and magnetic field gradients to encode the spatial coordinates of the fluid. When the fluid leaves the sample, its magnetization is recorded by a second rf coil. This scheme not only facilitates a time-dependent imaging of fluid flow, it also allows a separate optimization of encoding and detection subsystems to enhance overall sensitivity. The technique is demonstrated by imaging gas flow through a porous rock.

}, keywords = {mri}, isbn = {0031-9007}, doi = {Doi 10.1103/Physrevlett.95.075503}, url = {://WOS:000231247300028}, author = {Granwehr, J. and Harel, E. and Han, S. and Garcia, S. and Pines, A. and Sen, P. N. and Song, Y. Q.} } @article {321, title = {Hyperpolarized xenon nuclear spins detected by optical atomic magnetometry}, journal = {Physical Review Letters}, volume = {93}, year = {2004}, note = {Phys Rev Lett863ATTimes Cited:32Cited References Count:22}, month = {Oct 15}, abstract = {

We report the use of an atomic magnetometer based on nonlinear magneto-optical rotation with frequency-modulated light to detect nuclear magnetization of xenon gas. The magnetization of a spin-exchange-polarized xenon sample (1.7 cm(3) at a pressure of 5 bars, natural isotopic abundance, polarization 1\%), prepared remotely to the detection apparatus, is measured with an atomic sensor. An average magnetic field of similar to10 nG induced by the xenon sample on the 10 cm diameter atomic sensor is detected with signal-to-noise ratio similar to10, limited by residual noise in the magnetic environment. The possibility of using modern atomic magnetometers as detectors of nuclear magnetic resonance and in magnetic resonance imaging is discussed. Atomic magnetometers appear to be ideally suited for emerging low-field and remote-detection magnetic resonance applications.

}, keywords = {mri}, isbn = {0031-9007}, doi = {Doi 10.1103/Physrevlett.93.160801}, url = {://WOS:000224533300012}, author = {Yashchuk, V. V. and Granwehr, J. and Kimball, D. F. and Rochester, S. M. and Trabesinger, A. H. and Urban, J. T. and Budker, D. and Pines, A.} }