Holographic Imaging Based on Time-Domain Data of Natural-Fiber Containing Materials
Microwave and millimeter-wave holographic imaging has been well developed at PNNL [1-12]. Near real time imaging systems using this technology have been developed using linear arrays of microwave/millimeter wave antennas that are sequentially switched electronically to allow high-speed sampling along the array axis. Mechanical scanning in a perpendicular direction to the array axis then completes the sampling of a two dimensional aperture of wideband holographic image data. This data can then be reconstructed using the wideband holographic imaging algorithm resulting in a focused image. The wideband holographic imaging technique is described in detail in [4]. A similar scanning technique can be employed in a cylindrical fashion using a linear array that is scanned over a circular path around the target to be imaged [3, 5, 7]. The invention described in this report, is concerned with a specific technique used to spatially scan, or sample, along the axis of the array that results in a reduction of the number of physical antenna elements needed by approximately one-half compared to established techniques.
Low Pressure Electrospray Ionization System and Process for Effective Transmission of Ions
Achieving high sensitivity in electrospray ionization mass spectrometry (ESI-MS) is the key to effective analysis of complex biological sample. Every significant improvement in ESI-MS detection limit will enable applications otherwise impractical. Advances in ESI-MS sensitivity can also increase the dynamic range over which quantitative measurements can be performed. Currently, most sensitivity loss in ESI-MS is in the atmospheric pressure ESI interface region. The ion transmission through this interface is essentially limited by the small MS sampling inlet (typically 400 to 500 ƒÝm in diameter as required to maintain a good vacuum pressure in MS analyzer chamber) resulting in a
COLLECTION, RELEASE, AND DETECTION OF ANALYTES WITH POLYMER COMPOSITE SAMPLING MATERIALS (iEdison No. 0685901-14-0005)
A unique fiber core sampler composition, related systems, and techniques for designing, making, and using the same are described. The sampler is used to interface with existing field instrumentation, such as Ion Mobility Spectrometer (IMS) equipment. Desired sampler characteristics include its: stiffness/flexibility; thermal mass and conductivity; specific heat; trace substance collection/release dependability, sensitivity and repeatability; thickness; reusability; durability; stability for thermal cleaning; and the like. In one form the sampler has a glass fiber core with a thickness less than 0.3 millimeter that is coated with a polymer including one or more of: polymeric organofluorine, polyimide, polyamide, PolyBenzlmidazole (PBI), PolyDiMethylSiloxane (PDMS), sulfonated tetrafluoroethylene (PFSA) and Poly(2,6-diphenyl-p-phenylene Oxide) (PPPO). Multiple polymer coatings with the same or different polymer types may be included, core/substrate surface functionalization utilized, and/or the core/substrate may be at partially filled with thermally conductive particles.
SURFACE DETERMINATION SYSTEMS, THREAT DETECTION SYSTEMS AND MEDICAL TREATMENT SYSTEMS (NIH iEdison No. 0685901-20-0022, Grant No. CA227586)
This invention consists of new methods for accurately estimating the surface of the human body or objects that are scanned by active wideband microwave or millimeter-wave imaging systems. The invention improves upon the state of the art by carefully focusing the images to preserve phase information inherent in the propagation of the electromagnetic waves used to form the images, and then exploiting the fact that the phase of the reconstructed image follows the surface. This means that surfaces of constant phase in the reconstruction follow the contours of the body or target. Furthermore, if the image reconstruction is performed in an exacting manner, the surface of the body tracks the zero-phase contour precisely. The surface can therefore be estimated by forming a high-resolution image using backprojection or similar methods and then finding the surface by numerically finding the zero-phase position over a lattice of positions. High-resolution active wideband microwave and millimeter-wave imaging systems are typically formed by mechanically, or electronically scanning a transceiver over a 2D aperture. At each point in the aperture the transceiver emits a wideband signal that interacts with the target and is captured coherently by the receiver. The subsequent data are then three-dimensional consisting of two spatial axes and one frequency axis. These data can then be focused using backprojection or other similar methods. Resolution in microwave imaging is limited by diffraction in the lateral dimensions and by bandwidth in the range or depth dimension. Tracking the surface is typically done after image formation by taking the magnitude image and forming iso-surfaces, or surfaces of constant amplitude. This process causes errors in the surface estimation since it inherently assumes that brightness is related to position. A brighter zone in the image will appear closer than a dimmer zone, even if they are at the same depth. The new methods in this invention achieve high accuracy by eliminating the bias caused by the image amplitude variations and by exploiting the image phase. The image phase varies approximately 360 degrees for every half-wavelength in depth variation. The zero-phase position can be estimated to accuracies of better than a few degrees. Therefore, the surface can be estimated to small fraction of one-half wavelength. Normal methods are limited by the depth resolution, which is typically much larger than one-half wavelength.
SYSTEM AND METHOD OF PRECONCENTRATING ANALYTES IN A MICROFLUIDIC DEVICE
Electrokinetic injection is used almost exclusively for microchip electrophoresis. We describe a new approach, based on pneumatic valving, that overcomes the limitations of electrokinetic injection. A detailed description is in the attached file.
Ion manipulation device (iEdison NIH 0685901-13-0004.)
An ion manipulation method and device is disclosed. The device includes a pair of substantially parallel surfaces. An array of inner electrodes is contained within, and extends substantially along the length of, each parallel surface. The device includes a first outer array of electrodes and a second outer array of electrodes. Each outer array of electrodes is positioned on either side of the inner electrodes, and is contained within and extends substantially along the length of each parallel surface. A DC voltage is applied to the first and second outer array of electrodes. A RF voltage, with a superimposed electric field, is applied to the inner electrodes by applying the DC voltages to each electrode. Ions either move between the parallel surfaces within an ion confinement area or along paths in the direction of the electric field, or can be trapped in the ion confinement area.