Method for bulk separation of single-walled tubular fullerenes based on chirality, US6669918, 12/30/2003

A method for bulk separation of single-walled tubular fullerenes based on chirality is provided wherein a first step is the formation of a template on a crystalline substrate. The template has a plurality of openings which are oriented to energetically favor adsorption of a respective plurality of single-walled fullerenes having a tubular contour and a selected chirality. Next, the template is exposed to a suspension of single-walled tubular fullerenes of random chiralities for adsorption of single-walled tubular fullerenes of the selected chirality into the openings of template. Then, the template is removed from exposure to the suspension and the adsorbed single-walled tubular fullerenes of the selected chirality are removed from the template. The template may then be reused to adsorb further tubular fullerenes of the selected chirality from a suspension of tubular fullerenes of random chiralities.

Dual-band quadrifilar helix antenna, US6653987, 11/25/2003

Dual-band quadrifilar helix antennas, comprising four radiating elements arranged helically to define a cylinder of constant radius, each radiating element having an upper portion and a lower portion and a gap there between, each upper portion having an open end, and each lower portion having a feed point for receiving feed signals in phase quadrature. Disposed within each gap and electrically connected to each upper and lower portion is a corresponding parallel LC circuit configured to have a first impedance at a first frequency, and a second impedance greater than the first impedance, at a second frequency. Alternative embodiments include structures with ground planes and top-fed helices without ground planes.

Traffic flow management method and system for weather problem resolution, US6606553, 8/12/2003

Weather problem resolution in air traffic flow management is accomplished by automatically deriving a flow of constrained areas from a weather forecast product, generating a candidate flight list including conflict flights predicted to be affected by the flow constraint areas for each conflict flight from the candidate flight list order, generating reroute corridors available, and selecting the best available reroute corridor. Sector workloads are estimated which are affected by rerouting of the conflict flight onto the selected corridor. The corridor is accepted for the conflict flight if sector workloads are below preset limits, or, if the flight would cause the sector workloads to increase beyond the preset workload limits, a check is made for ground delaying the flight, and if found impossible, rejecting the corridor and examining the next available corridor for rerouting the flight.

Method for generating conflict resolutions for air traffic control of free flight operations, US6604044, 8/5/2003

A computationally efficient method for automatically generating lateral resolutions for air traffic control problems for a given aircraft allows for prediction and evaluation of required separation between aircraft, between aircraft and airspace, and problems with assigned metering time. Upon a possible problem being predicted, lateral resolutions are created which provide plans to re-route the original flight trajectory of the aircraft in order to avoid a possible problem by examining the space surrounding the aircraft, iteratively adding data on each conflict encountered into a conflict database, calculating and probing maneuver trajectories for all conflicts in the conflict database, and selecting the most appropriate of the created maneuver trajectories.

Spatial null steering microstrip antenna array, US6597316, 7/25/2003

A spatial null steering microstrip antenna array comprising two concentric microstrip patch antenna elements. An inner circular antenna is used as an auxiliary element in nulling interference received by an outer annular ring antenna disposed around the inner antenna. The outer annular antenna is resonant in a higher order mode but forced to generate a right hand circularly polarized lower order (TM11) far field radiation pattern, thereby allowing co-modal phase tracking between the two antenna elements for adaptive cancellation. Each antenna element is appropriately excited by symmetrically spaced probes. Other applications of the antenna array include GPS multipath suppression, simultaneous satellite and terrestrial communications, and co-site interference suppression. Dual frequency band applications are achieved by stacked array configurations.

Apparatus and method for measuring concentrations of a chemical/biological/nuclear agent in an environment, US6539311, 03/25/2003

An apparatus and method for measuring chemical, biological, and nuclear agents in an environment which includes several detectors capable of measuring concentrations of the agents and a processor capable of operating an algorithm which, based on two sequential measures of the agent's concentration, estimates decay or elevation rate of the agent's concentration and feeds this estimated change rate to a Kalman filter which predicts the next measurement. The predicted next measurement of concentration is compared with the measured concentration and the error is calculated based on the discrepancy between the measured and predicted concentrations of the agent in the environment. Using this error, the attributes of the Kalman filter are adjusted to lower noise signals and improve further predictions of the concentration of the agent during the mission time.

Movement history based selective distribution of generally broadcast information, US6522250, 02/18/2003

A message filtering system is provided for filtering generally broadcast messages received by a movable unit. The generally broadcast message includes an information segment including location, time, and/or velocity details relating to an event of potential interest for the unit. The movement history of the unit is stored along with data selection information. A determination is made as to whether the information contained in the broadcast information segment is of interest based on this stored information.