Abstract:
A device is presented for assisting an insufficient aortic valve. The device is configured as an auxiliary valve and comprises a resilient deformable sleeve-like valve, deformation of the sleeve-like valve shifting the valve between its closed and opened positions.
Abstract:
A device and method for manipulating a direction of motion of current carriers are presented. The device comprises a structure containing a two-dimensional gas of current carriers configured to define at least one region of inhomogeneity which is characterized by a substantially varying value of at least one parameter from the following: a spin-orbit coupling constant, density of the spin carriers, and a mobility of the gas. The device may be configured and operable to perform spin manipulation of a flux of the spin carrying current carriers to provide at least one of the following types of deviation of said spin-carrying current carriers: spin dependent refraction, spin dependent reflection and spin dependent diffraction on desired deviation angles of a direction of motion of the spin-carrying current carriers being incident on said at least one region of inhomogeneity. The device may also be configured and operable to allow emission of the current carriers from a diffusive region at one side of the region of inhomogeneity to a ballistic region at the opposite side of the region of inhomogeneity to provide the current carriers propagation in multiple directions in the ballistic region with a wide angular range of these directions.
Abstract:
A display device is presented. The display device includes an electrodes' arrangement and an electrons' extractor. The electrodes' arrangement comprises a Cathode electrode layer having at least one Cathode electrode and an Anode electrode layer having at least one Anode electrode, the Cathode and Anode electrode layers being accommodated in a spaced-apart relationship with a gap between them. The Anode layer carries a luminescent screen assembly on its surface. The electrodes arrangement is operable to create a desired electrical field between the electrodes. The electrons' extractor operates to extract electrons from at least a selected region of the Cathode electrode layer by illuminating this Cathode region with exciting illumination of a predetermined wavelength range to cause the electron emission from the illuminated Cathode region.
Abstract:
A method and device are provided for automatically generating a key and a conjugate key to be used in an optical code division multiple access system. The method comprises applying a down conversion process to pump input light to thereby produce down converted broadband signal and idler fields that are complex conjugates of each other. The signal and idler fields thus serve as the key and its conjugate. Also provided according to the invention is a method for use in coding/decoding a signal in an optical code division multiple access system.
Abstract:
The present invention provides a new method for the synthesis of a novel kind of high-surface-area structures. A substrate is provided having pores or channels functionalized with an agent capable of binding nanoparticles, said pores or channels having a cross-sectional size of from about several nanometers to about 100 microns. A colloid solution comprising stabilized nanoparticles and a solvent is passed through said substrate, so as to bind and form more than one layer of nanoparticles in the pores or channels, where the bound nanoparticles spontaneously coalesce to form a coherent material having a substantially hollow structure and being composed of nanoparticles, where said structure follows the shape of said pores or channels in the substrate. The structures properties can be modified by deposition of another material, to form structures coated by the other material on their surface. The structures (with or without modification) can be separated from the porous substrate to obtain a material having a desired structure, for example a tubular structure.
Abstract:
An auto-focusing method and device are presented for determining an in-focus position of a sample supported on a substrate plate made of a material transparent with respect to incident electromagnetic radiation. The method utilizes an optical system capable of directing incident electromagnetic radiation towards the sample and collecting reflections of the incident electromagnetic radiation that are to be detected. A focal plane of an objective lens arrangement is located at a predetermined distance from a surface of the substrate, which is opposite to the sample-supporting surface of the substrate. A continuous displacement of the focal plane relative to the substrate along the optical axis of the objective lens arrangement is provided, while concurrently directing the incident radiation towards the sample through the objective lens arrangement to thereby focus the incident radiation to a location at the focal plane of the objective lens arrangement. Reflected components of the electromagnetic radiation collected through said objective lens arrangement are continuously detected. The detected reflected components are characterized by a first intensity peak corresponding to an in-focus position of said opposite surface of the substrate, and a second intensity peak spaced in time from the first intensity peak and corresponding to an in-focus position of said sample-supporting surface of the substrate. This technique enables imaging of the sample when in the in-focus position of the sample-supporting surface of the substrate.
Abstract:
The present invention provides a method for producing carbon structures by laser irradiation, the method comprising:(i) providing a substrate, at least a portion of whose surface being covered with a sample comprising one or more thermally degradable organic compounds, said sample being in the form of homogeneous solution, suspension or emulsion; (ii) irradiating said covered surface portion locally by applying a focused laser beam, thus resulting in local deposition of carbon, and (iii) repeating step (ii) by moving either the laser beam or the sample, thus creating a desired pattern of carbon structures. The present invention further provides carbon structures produced by the method of the invention.
Abstract:
A central solar receiver comprising a tubular housing (1) with a central axis, a radiation admitting aperture (5) and an absorber chamber having an outer wall, two oppositely located ends (2, 3), an inner-wall-forming substantially tubular transparent window (6) co-axial with the tubular housing. The solar receiver further comprises injection means (26) near a first of the oppositely located ends and at least one egress opening means (30) near a second of the oppositely located ends. The injection means are capable of injecting into the absorber chamber a multicomponent fluid mixture comprising at least one radiation absorbing component and are so designed that the fluid mixture is injected into the absorber chamber adjacent and essentially tangentially to the outer wall, whereby contact between the mixture and the window is reduced. The egress opening enables the egress of the fluid mixture from the absorber chamber.
Abstract:
A transparent window (4) for a solar radiation receiver assembly and a solar receiver assembly using the same, which assembly comprising a housing (2) having an aperture (3) and holding a volumetric solar absorber (5), the transparent window (4) mounted in the aperture (3) for the admission of incident concentrated solar radiation, shielding the volumetric solar absorber so as to form a sealed absorber chamber capable of holding a fluid medium, and means for the ingress and egress of the fluid medium. The transparent window (4) consists of a plurality of discrete transparent window segments (11, 12) set in a common matrix (10) and is capable of withstanding high temperature.
Abstract:
The invention provides a multilayered nanostructure comprising at least one first layered nanotube being of at least one first inorganic material and having an inner void holding at least one second layered nanotube being of at least one second inorganic material; wherein said at least one first nanotube and at least one second nanotube differ in at least one of structure and material. The invention further provides processes for the manufacture of multilayered nanostructures and uses thereof.