Abstract: The present disclosure relates to a chimeric influenza virus hemagglutinin (HA) polypeptide, comprising one or more stem domain sequence, each having at least 60% homology with a stem domain consensus sequence of H1 subtype HA (H1 HA) and/or H5 subtype HA (H5 HA), fused with one or more globular head domain sequence, each having at least 60% homology with a globular head domain consensus sequence of H1 subtype HA (H1 HA) or H5 subtype HA (H5 HA).

Abstract: The present disclosure relates to a chimeric influenza virus hemagglutinin (HA) polypeptide, comprising one or more stem domain sequence, each having at least 60% homology with a stem domain consensus sequence of H1 subtype HA (H1 HA) and/or H5 subtype HA (H5 HA), fused with one or more globular head domain sequence, each having at least 60% homology with a globular head domain consensus sequence of H1 subtype HA (H1 HA) or H5 subtype HA (H5 HA).

Abstract: A weather identification system is provided which employs a first photosensitive receiver positioned directly in the path of a beam of light a predetermined distance from a partially coherent light beam source. The first photosensitive receiver is in direct optical communication with the light beam source to produce electronic signals in response to scintillations caused by particle movement between the source and the first receiver. A second photosensitive receiver is positioned out of the path of the beam of light and is oriented at an oblique angle relative thereto to provide an output indicative of forward scattering of light from scintillations that occur in the beam of light. The signals from the second photosensitive receiver are AC coupled to provide an output indicative of rate of fluctuation and having a signal strength characteristic that even distinguishes between light drizzle and fog.

Abstract: An optical flow sensor determines the velocity of a moving flow of air or other gas utilizing a plurality of photodetectors spaced apart in a direction parallel to the direction of gas flow. An optical beam is transmitted to the photodetectors across the flowing gas. Scintillations that occur in the flowing gas due to eddies and particulates in the gas are detected in the photodetectors at slightly different times. The output signals of the photodetectors are conditioned, amplified and transformed to digital form. Temporal cross correlation analysis is then performed on the digitized signals in a digital signal processor utilizing a fast correlation algorithm in which the total number of calculations is proportional to 2N, as contrasted with conventional systems in which the number of correlations is proportional to N2. A time differential between signals from the different photodetectors is then calculated electronically.

Abstract: An optical flow sensor determines the velocity of a moving flow of air or other gas utilizing a plurality of photodetectors spaced apart in a direction parallel to the direction of gas flow. An optical beam is transmitted to the photodetectors across the flowing gas. Scintillations that occur in the flowing gas due to eddies and particulates in the gas are detected in the photodetectors at slightly different times. The output signals of the photodetectors are conditioned, amplified and transformed to digital form. Temporal cross correlation analysis is then performed on the digitized signals in a digital signal processor utilizing a fast correlation algorithm in which the total number of calculations is proportional to 2N, as contrasted with conventional systems in which the number of correlations is proportional to N2. A time differential between signals from the different photodetectors is then calculated electronically.

Abstract: An optical flow sensor determines the velocity of a moving flow of air or other gas utilizing a plurality of photodetectors spaced apart in a direction parallel to the direction of gas flow. An optical beam is transmitted across the flowing gas and falls upon the photodetectors. Scintillations that occur in the flowing gas due to eddies and particulates in the gas are detected in all of the photodetectors, but at slightly different times due to the longitudinal separation of the photodetectors in the direction of gas flow. The output signals of the photodetectors are conditioned and amplified and transformed to digital form. Temporal cross correlation analysis is then performed on the digitized signals in a digital signal processor. A time differential between signals from the different photodetectors is then calculated electronically.

Abstract: An open-air optical communication system is provided which enhances accuracy and reliability of signal transmission by utilizing multiple optical receivers. Two or more receivers are positioned within the path of a collimated optical beam emitted by a remote transmitter. The receiving lenses are of equal size and are positioned apart in a plane perpendicular to the optical beam a distance at least as great as the receiving lens diameter. The receiving lenses thereby receive two or more signals through different optical paths. All of these signals are electronically combined to yield one composite received signal that is better than any one of the individual received signals. The system employs automated gain control circuitry to further eliminate any signal fluctuations caused by atmospheric phenomena such as turbulence, fog, smoke, dust, rain, snow, etc. By utilizing multiple receivers, degradation of the transmitted signal due to atmospheric turbulence induced optical scintillation is significantly reduced.

Abstract: An optical scintillometer is provided which is operative to measure atmospheric wake vortex turbulence intensity up to a distance of ten kilometers. The optical scintillometer provides real time continuous measurements of aircraft generated wake vortex turbulence intensity in the field of operations employing a transmitter, receiver, and digital processing circuitry. The signal is digitized before comparison with a threshold to eliminate events attributable to objects moving through the path of the optical transmitter and receiver. The system is thereby able to perform calculations to adjust the first order log-amplitude variance function in the saturation regime. An extremely important aspect of the invention is the digitization of the signal and its comparison with the threshold signal. Because a digital signal is compared with a threshold signal level, invalid signal inputs are excluded from the calculation of path-averaged turbulence intensity.

Abstract: An optical scintillometer is provided which is operative to measure atmospheric turbulence intensity up to a distance of two and a half kilometers. The optical scintillometer provides real time continuous measurements of turbulence intensity in the field of operations employing a transmitter, receiver, and digital processing circuitry. The signal is digitized before comparison with a threshold to eliminate events attributable to objects moving through the path of the optical transmitter and receiver. The system is thereby able to perform calculations to adjust the first order log-amplitude variance function in the saturation regime. An extremely important aspect of the invention is the digitization of the signal and its comparison with the threshold signal. Because a digital signal is compared with a threshold signal level, invalid signal inputs are excluded from the calculation of path-averaged turbulence intensity.

Abstract: An optical weather identification system employing a light beam source that transmits a partial coherent beam of light along a prescribed path to detect precipitation and distinguish rain from snow is improved by the provision of another channel that is further able to distinguish solidified precipitation, namely sleet and hail. The additional output is derived from an acoustic, rather than an optical input. An acoustic receiver is positioned at a remote site to be monitored, along with an optical transmitter and receiver. The acoustic receiver employs a microphone located beneath the center of the underside of a domed top of the acoustic receiver casing. Falling precipitation is optically detected using prior optical precipitation detection techniques. However, if the particles of precipitation are solidified, as in the case of sleet and hail, the microphone will detect the impact of the sleet and hail on the domed receiver casing as an audible input.

Abstract: A weather identification system is provided which employs a first photosensitive receiver positioned directly in the path of a beam of light a predetermined distance from a partially coherent light beam source. The first photosensitive receiver is in direct optical communication with the light beam source to produce electronic signals in response to scintillations caused by particle movement between the source and the first receiver. Signals from the detected scintillations are filtered to provide an output having a frequency range above one kilohertz indicative of rain intensity, and a second output having a frequency range lower than two hundred fifty hertz indicative of snow intensity. A second photosensitive receiver is positioned out of the path of the beam of light and is oriented at an oblique angle relative thereto to provide an output indicative of forward scattering of light from scintillations that occur in the beam of light.

Abstract: A weather identification system is provided for remotely detecting precipitation and for determining the nature of precipitation in an open environment, as at an aircraft landing field. The system employs an optical transmitter and receiver, wherein particles of precipitation passing through a light beam from the transmitter cause scintillations which are detected at the receiver. A drastic reduction in spatial separation between the light transmitter and receiver makes possible the use of a partially coherent light beam in place of a conventional laser beam. The transmitter and receiver are spaced apart a distance of approximately one meter, and the product of one half of the angle of incoherency multiplied by the spatial separation between the transmitter and receiver is no greater than about 2.5 millimeters. Rain passing through the light beam produces scintillations with substantial frequency components above one kilohertz. Snow induced frequencies are primarily below a few hundred hertz.

Abstract: A precipitation gauge is provided for remotely detecting precipitation and for measuring the rate of precipitation in an open environment, such as an aircraft landing field. The system employs an optical transmitter and receiver, wherein particles of precipitation passing through a light beam from the transmitter cause scintillations at the receiver. The spatial separation between the light transmitter and receiver is quite small, typically substantially less than one meter. The small separation between the transmitter and the receiver is made possible by the use of a partially coherent light beam, in place of a conventional laser beam. The transmitter and receiver are spaced apart a distance of approximately 0.6 meters. The product of one half of the angle of incoherency multiplied by the spatial separation between the transmitter and receiver is preferably about 1.5 millimeters.

Abstract: A new class of dispersant compounds and compositions and a series of novel lubricant compositions are disclosed. Polyalkylene glycol succinimides which may be derived from maleic acids and anhydrides are useful as dispersants in, for example, polyglycol base fluids. Lubricating compositions including such dispersant compositions are also described.