Determination of cloud liquid water content using the SSM/I

As part of a calibration/validation effort for the Special Sensor Microwave/Imager (SSM/I), coincident observations of SSM/I brightness temperatures and surface-based observations of cloud liquid water were obtained. These observations were used to validate initial algorithms and to derive an improved algorithm. The initial algorithms were divided into latitudinal-, seasonal-, and surface-type zones. It was found that these initial algorithms, which were of the D-matrix type, did not yield sufficiently accurate results. The surface-based measurements of channels were investigated; however, the 85 V channel was excluded because of excessive noise. It was found that there is no significant correlation between the SSM/I brightness temperatures and the surface-based cloud liquid water determination when the background surface is land or snow. A high correlation was found between brightness temperatures and ground-based measurements over the ocean     

Acoustic rhinometry in the study of the acute nasal allergic response

Acoustic rhinometry is a recently developed method for the objective assessment of nasal patency. In this study, acoustic rhinometry was used to measure changes in nasal cavity dimensions in the immediate response to nasal allergen challenge in eight pollen-sensitive subjects. Acoustic rhinometric changes were compared with subjective symptoms, as well as histamine in nasal secretions, cytology of nasal mucosal scrapings, and changes in olfactory function. A significantly greater decrease in nasal airway caliber occurred following allergen challenge as compared to buffer diluent challenge in the same individuals (70% +/- 7% versus 22% +/- 5%). During an allergic response, a strong correlation was found between the minimum cross-sectional area and the volume of the nasal cavity measured by acoustic rhinometry (r = .9). However, no correlation was observed between nasal airway caliber and concomitant subjective congestion reported by the subjects. A modest decrease in olfactory function was seen following allergen challenge (3.1 +/- 1.4 fewer odors identified correctly out of 20; p = .08). However, the alterations of olfactory function did not correlate with changes in nasal patency. The results presented in this study demonstrate that acoustic rhinometry has great potential as a reproducible method for the objective assessment of nasal obstruction occurring in nasal allergen challenge studies.     

Considerations for Microwave Remote Sensing of Ocean-Surface Salinity

Parametric calculations of the microwave emission from the ocean surface are presented to determine the optimum electromagnetic wavelength for measuring salinity. At 800 MHz, a target accuracy of 240 parts per million is within the state of the art provided that emission due to surface roughness is negligible, or correctable, and that the error resulting from galactic radiation can be removed using an upward-looking antenna. Examples of salinity measurements relevant to physical oceanography are presented, and a possible spacecraft University of Massachusetts, Amherst, MA 01003.system is discussed.     

“Open” systems relaying

This paper describes a development in relaying hardware and philosophy which has been made possible by DSPs and industrial grade PCs. Details are given of a prototype design capable of being assembled and configured by a utility and results of tests on this prototype using the RTDS at the Manitoba HVDC Research Centre are presented. The project is a joint effort between the University of Manitoba and Manitoba Hydro     

A new SONOS memory using source-side injection for programming

We reported a new polysilicon-oxide-nitride-oxide-silicon (SONOS) nonvolatile memory using channel hot electron injection for high-speed programming. For the first time, we demonstrated that source-side injection technique, which is commonly used in floating gate nonvolatile memories for its high programming efficiency, can also be used in a SONOS device for achieving high-speed programming. Erase of the device is achieved by tunneling of electrons through the thin top oxide of the ONO charge storage stack. Since the thin top oxide is grown from the nitride layer, the self-saturated nature of the oxidation allows better thickness control. Endurance characteristics indicates that quality of the thin top grown from nitride is as good as the tunnel oxide grown from the silicon substrate. By increasing the top oxide thickness, it is possible to achieve ten years of retention requirement. The self-aligned sidewall gate structure allows small cell size for high density applications     

The Input Admittance of a Rectangular Waveguide-Fed Aperture Under an Inhomogeneous Plasma: Theory and Experiment

The admittance of a waveguide-fed rectangular aperture under an inhomogeneous plasma is derived and experimentally verified. For both flowing and stationary inhomogeneoas plasmas, the agreement is at least as accurate as presently available plasma diagnostic techniques will allow. It is shown that there is a clear separation of the dependence of aperture-admittance properties upon plasma properties, such as electron density, profile shape and collision frequency, over two to three decades of peak electron density, change. The collision frequency primarily affects the aperture conductance, particularly for critical and overdense plasmas. The profile shape, i.e., a boundary layer, primarily affects the aperture susceptance.     

Minimum depth electron probe x-ray microanalysis as a means for determining the sulphur content of the human hair surface

By using incident electron energies as low as 3 keV it has been shown both theoretically and practically that the maximum depth for the excitation of sulphur Kα x-rays from a sulphur-containing proteinaceous solid can be restricted to 110 nm. This approach has been used to determine the concentration of sulphur in the immediate surface of human hair, and more particularly associated with the A-layer subcomponent of the hair cuticle. The value obtained was 11.8 weight % (± 0.92, n = 10).