Recursos de colección

Caltech Authors (142.336 recursos)

Repository of works by Caltech published authors.

Type = Patent

Mostrando recursos 1 - 20 de 39

  1. Controlled transitory or sustained gliding flight with dihedral angle and trailing flaps

    Paranjape, Aditya A.; Chung, Soon-Jo
    A micro aerial vehicle capable of controlled transitory or sustained gliding flight. The vehicle includes a fuselage. A pair of articulated wings are forward of a center of gravity of the vehicle, the wings being articulated and having trailing edge flaps, and having actuators for controlling the dihedral angles of the wings and the flaps for effective yaw control across the flight envelope. The dihedral angles can be varied symmetrically on both wings to control the aircraft speed independently of the angle of attack and flight-path angle, while an asymmetric dihedral setting can be used to control yaw and the...

  2. Modeling Plant Development with Gene Regulation Networks Including Signaling and Cell Division

    Jonsson, H.; Shapiro, B. E.; Meyerowitz, E. M.; Mjolsness, E.
    The shoot apical meristem of Arabidopsis thaliana is an example of a developmental system which can be modeled at genetic and mechanical levels provided that suitable mathematical and computational tools are available to represent intercellular signaling, cell cycling, mechanical stresses, and a changing topology of neighborhood relationships between compartments. In this paper, we present a simplified dynamical 2-dimensional model of a growing plant. Cells in the shoot grow and proliferate, while the number of stem cells at the apex stays constant due to differentiation into tissue cells. Cell types are defined by protein concentrations within the cells, and the dynamics...

  3. System and method for making nanoparticles using atmospheric-pressure plasma microreactor

    Sankaran, R. Mohan; Giapis, Konstantinos P.; Flagan, Richard C.; Holunga, Dean M.
    A system and method for making nanoparticles. The system includes a first cathode including a first metal tube associated with a first end and a second end, a first anode including a second metal tube associated with a third end and a fourth end, and a first container including a first gas inlet. The first end and the third end are located inside the first container. The first end and the third end are separated by a first gap, the first metal tube is configured to allow a first gas to flow from the second end to the first end,...

  4. Cross-flow differential migration classifier

    Flagan, Richard C.
    A method, system, apparatus, and article of manufacture provide a cross-flow migration classifier capable of separating particles. The classifier provides a channel through which a sample, having one or more particles, passes in a first direction, wherein the channel comprises two or more walls that are permeable to a flow of fluid. A cross-flow enters the channel through one of the permeable walls and exits through another of the permeable walls. An imposed field is applied in a second direction that is counter to the cross-flow and having an orthogonal component to the first direction. The imposed field causes one...

  5. Micro-cavity gas and vapor sensors and detection methods

    Armani, Andrea M.; Su, Tsu-Te J.; Flagan, Richard C.; Fraser, Scott E.
    Micro-cavity gas or vapor sensors and gas or vapor detection methods. Optical energy is introduced into a resonant micro-cavity having a deformable coating such as a polymer. The coating swells or expands when it is exposed to or absorbs a gas or vapor, thereby changing the resonant wavelength of optical energy circulating within the micro-cavity/coating. Expansion or swelling of the coating may be reversible such that it contracts when gas or vapor diffuses from the coating. The coating deformation and/or a change of one or more optical properties of the optical energy circulating within the micro-cavity are used to detect...

  6. Click chemistry surface functionalization for resonant micro-cavity sensors

    Armani, Andrea M.; Alabi, Akinleye C.; Davis, Mark E.; Flagan, Richard C.; Fraser, Scott E.
    Micro-cavity resonant sensors have outer surfaces that are functionalized using click chemistry, e.g., involving a cycloaddition reaction of an alkyne functional group and an azide functional group. A first polymer linking element binds to an outer surface of the micro-cavity and has an azide functional group, which bonds to an alkyne functional group of a second polymer linking element as a result of a cycloaddition reaction. A functionalization element such as an antibody, antigen or protein for sensing a target molecule is bound to the second linking element.

  7. Particle surface treatment for promoting condensation

    Flagan, Richard C.; Kaufman, Stanley L.; Sem, Gilmore J.
    A system is disclosed for condensation particle counting in conjunction with modifying an aerosol to enhance the formation and growth of droplets of a selected working fluid, preferably water. Before saturation with the working fluid, the aerosol is exposed to an aerosol modifying component, preferably a vapor including molecules that are adsorbed onto surfaces of the particles or other elements suspended in the aerosol. Adsorption alters the surface character of the suspended elements towards increased affinity for the vapor of the working fluid, to promote the formation and growth of working fluid droplets. The droplets are optically detected to indicate...

  8. Control of aerodynamic forces by variable wetted surface morphology

    McKeon, Beverley J.
    Systems and methods for providing dynamic control to a vehicle in a dynamic fluid. The systems and methods of the invention relate to one or more morphable surfaces that can be controlled by a controller and an actuator in an active manner to provide asperities that interact with a fluid moving across the morphable surfaces. By controlling the size, shape and location of the asperities, one can exert control authority over the motion of the vehicle relative to the fluid, including a speed, a direction and an attitude of the vehicle. Examples of materials that provide suitable morphable surfaces include...

  9. Fluid flow control using boundary layer control

    Morrison, Jonathan Finlay; Dearing, Stella Silvana; Arthur, Graham G.; McKeon, Beverley Jane; Cui, Zheng
    A fluid flow control device (210) including an active actuator surface may be used to control boundary layer separation by controllably deforming the actuator surface to create a depression in an exterior face of the surface. Boundary layer control may thus be achieved by producing a turbulent state which is more resistant to separation than the original laminar flow by energising the boundary layer and preventing it from separating. The surface may comprise an electroactive polymer membrane (100) supported on a substrate (200) and a set of electrodes (300, 310) adjacent to a cavity in the substrate. The electrodes may...

  10. Control of aerodynamic forces by variable wetted surface morphology

    McKeon, Beverley J.
    Systems and methods for providing dynamic control to a vehicle in a dynamic fluid. The systems and methods of the invention relate to one or more morphable surfaces that can be controlled by a controller and an actuator in an active manner to provide asperities that interact with a fluid moving across the morphable surfaces. By controlling the size, shape and location of the asperities, one can exert control authority over the motion of the vehicle relative to the fluid, including a speed, a direction and an attitude of the vehicle. Examples of materials that provide suitable morphable surfaces include...

  11. Dynamic roughness for aerodynamic applications

    McKeon, Beverley J.; Yu, Christopher
    Systems and methods for providing dynamic control to a surface immersed in a dynamic fluid. The systems and methods of the invention relate to one or more morphable surfaces that can be control in an active manner to provide asperities that interact with a fluid moving across the morphable surfaces. By controlling the size, shape and location of the asperities, one can exert control authority over the motion of the surface relative to the fluid. Examples of materials that provide suitable morphable surfaces include ionic polymer metal composites and shape memory polymers, both of which types of material are commercially...

  12. Continuous flow mobility classifier interface with mass spectrometer

    Brunelli, Nicholas; Giapis, Konstantinos P.; Flagan, Richard C.; Beauchamp, Jesse L.; Neidholdt, Evan
    A continuous flow mobility classifier provide the ability to perform two-dimensional separation in mass spectrometry. An ionization system is used to ionize a sample. A differential mobility analyzer (DMA) (e.g., a nano-radial DMA) is coupled to the ionization system and to a mass spectrometer. The nano-RDMA is configured to separate the ionized sample by mobility for subsequent mass analysis by the mass spectrometer.

  13. Aerosol process for fabricating discontinuous floating gate microelectronic devices

    Flagan, Richard C.; Atwater, Harry A.; Ostraat, Michele L.
    A process for forming an aerosol of semiconductor nanoparticles includes pyrolyzing a semiconductor material-containing gas then quenching the gas being pyrolyzed to control particle size and prevent uncontrolled coagulation. The aerosol is heated to densify the particles and form crystalline nanoparticles. In an exemplary embodiment, the crystalline particles are advantageously classified by size using a differential mobility analyzer and particles having diameters outside of a pre-selected range of sizes, are removed from the aerosol. In an exemplary embodiment, the crystalline, classified and densified nanoparticles are oxidized to form a continuous oxide shell over the semiconductor core of the particles. The...

  14. Aerosol silicon nanoparticles for use in semiconductor device fabrication

    Flagan, Richard C.; Boer, Elizabeth A.; Ostraat, Michele L.; Atwater, Harry A.; Bell, Lloyd D. II
    A stratum or discontinuous monolayer of dielectric-coated semiconductor particles includes a high density of semiconductor nanoparticles with a tightly controlled range of particle sizes in the nanometer range. In an exemplary embodiment, the nanoparticles of the stratum are substantially the same size and include cores which are crystalline, preferably single crystalline, and include a density which is approximately the same as the bulk density of the semiconductor material of which the particle cores are formed. In an exemplary embodiment, the cores and particles are preferably spherical in shape. The stratum is characterized by a uniform particle density on the order...

  15. Fast mixing condensation nucleus counter

    Flagan, Richard C.; Wang, Jian
    A fast mixing condensation nucleus counter useful for detecting particles entrained in a sample gas stream is provided. The fast mixing condensation nucleus counter comprises a detector and a mixing condensation device having a mixing chamber adapted to allow gas to flow from an inlet to an outlet, wherein the outlet directs the gas flow to the detector. The mixing chamber has an inlet for introducing vapor-laden gas into the chamber and at least one nozzle for introducing a sample gas having particles entrained therein into the chamber. The inlet and nozzle are arranged such that the vapor-laden gas and...

  16. Techniques for characterizing cloud condensation nuclel

    Flagan, Richard C.; Chuang, Patrick Yung-Shie
    A cloud condensation nucleus spectrometer having a streamwise segmented condensation nucleus growth column. The condensation nucleus growth column includes alternating hot and cold temperature-maintaining segments arranged next to one another. The temperature difference between adjacent hot and cold temperature-maintaining segments increases from the input opening to an output opening of the condensation nucleus growth column to produce a supersaturation distribution that increases from the input opening to the output opening.

  17. Cloud condensation nucleus spectrometer

    Flagan, Richard C.; Chuang, Patrick Yung-Shie
    A cloud condensation nucleus spectrometer having a streamwise segmented condensation nucleus growth column. The condensation nucleus growth column includes alternating hot and cold temperature-maintaining segments arranged next to one another. The temperature difference between adjacent hot and cold temperature-maintaining segments increases from the input opening to an output opening of the condensation nucleus growth column to produce a supersaturation distribution that increases from the input opening to the output opening.

  18. Enhanced automated classified aerosol detector

    Flagan, Richard C.; Collins, Donald R.
    A scanning differential mobility analysis system having a charging device, a scanning differential mobility analyzer, a flow control, and a particle detector. The charging probability and the flow rates can be dynamically adjusted according to the instant size of the particles under measurement.

  19. Automated mobility-classified-aerosol detector

    Russell, Lynn M.; Flagan, Richard C.; Zhang, Shou-Hua
    An aerosol detection system for measuring particle number distribution with respect to particle dimension in an aerosol sample. The system includes an alternating dual-bag sampler, a radially classified differential mobility analyzer, and a condensation nucleus counter. Pressure variations in sampling are compensated by feedback control of volumetric flow rates using a plurality of flow control elements.

  20. Method of measuring aerosol particles using automated mobility-classified aerosol detector

    Russell, Lynn M.; Flagan, Richard C.; Zhang, Shou-Hua
    An aerosol detection system for measuring particle number distribution with respect to particle dimension in an aerosol sample. The system includes an alternating dual-bag sampler, a radially classified differential mobility analyzer, and a condensation nucleus counter. Pressure variations in sampling are compensated by feedback control of volumetric flow rates.

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