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Showing 1 to 20 of 766 for “"Helical"”.
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Thermomechanics of helical strands and helical-fiber-reinforced rods
Helical strands, or helically wound cables, are made of layers of individual wires wrapped around a common central axis. They are seen in ropes and power transmission cables. Similar structures are also present in biological tissues in the form of helical fiber reinforced composites. Regardless of …
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Broadband Helical Dipole Arrays
Made available in DSpace on 2014-12-08T22:23:53Z (GMT). No. of bitstreams: 1 6604305.pdf: 4848445 bytes, checksum: c3ad9d46a6ac38b12e2e8584b9595b2b (MD5) Previous issue date: 1965
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Helical Reconstruction in RELION
Helical assemblies of proteins are ubiquitous in nature and they perform vital functions in a wide range of organisms. The recent development of direct electron detectors and other imaging techniques in cryo-electron microscopy (cryo-EM) has opened new possibilities in solving helical structures at …
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Multifilar Hemispherical Helical Antennas
Helices are broadband antennas that provide moderate gain, largely real input impedance and circular polarization when operating in the axial mode regime. A modified form of the helix, the spherical helix, has been shown to yield similar polarization and gain characteristics over a narrow bandwidth …
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The spherical helical antenna
The spherical helical antenna is investigated as a new variation of the conventional helical antenna. The spherical helix is a wire antenna in a helix shape that is wound over a spherical surface instead of the standard cylindrical one. Analysis of this structure requires numerical methods and …
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The Spiro-Helical Antenna
… made of a spiral wire wrapped into a larger helical shape is introduced. The geometry of this antenna, which is a doubly helical structure, is fully described by five independent parameters, including two radial dimensions, two pitch angles, and the number of turns. Radiation properties of …
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Microwave Properties of Helical Resonators
… investigates the electromagnetic resonances of helical structures at microwave frequencies through both modelling and experimentation, with a particular emphasis on the relatively unexplored higher-order modes. By systematically varying geometric parameters, especially pitch, this study reveals …
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Tri-helical direct gravure coating
Tri-helical, gravure roll coating, operated in reverse mode, is investigated via a combined experimental, theoretical and computational approach. New experiments were conducted on a pilot coating rig, designed to simulate the industrial process. Flow visualisations reveal the underlying flow …
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Large Deflections of Helical Springs
The problem analyzed is that of a helical spring subjected to end couples and forces which produce large deflections of the spring. These deflections are such that the angle of rotation of one end of the spring centerline with respect to the other end of the spring centerline exceeds the range …
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Induction Motors With Rotor Helical Motion
… The rotor can move rotary, linearly or with helical motion. The linear motion generates dynamic end effect on both linear and rotary armature. Modeling such an effect in rotary armature is a significant challenge as it requires a solution considering motion with two degrees of mechanical …
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Investigations of Normal Mode Helical Dipoles
Made available in DSpace on 2014-12-08T22:24:33Z (GMT). No. of bitstreams: 1 6910889.pdf: 3630401 bytes, checksum: e8957c6b1d2164e72fbb5db99142af43 (MD5) Previous issue date: 1968
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Helical waves in Earth's outer core
… the waves has the potential to drive a \emph{helical wave dynamo} \citep{davidson2014}.
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Self-Assembly of Functional Helical Metallopolymers
… conjugated imine-based ligand strands that are helically wrapped around a linear array of closely spaced Cu atoms. To date, their development has been faced with several synthetic challenges. Moreover, the absence of methodologies to characterise and control the structures of these …
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Electromagnetic wave propagation on helical conductors
Thesis (Sc.D.) Massachusetts Institute of Technology. Dept. of Electrical Engineering, 1951.
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Helical Antennas with Truncated Spherical Geometry
A new variation of the spherical helical antenna made of a wire wound over a hemispherical surface and backed by a conducting ground plane is introduced. A constant spacing is maintained between the turns of winding. The geometry of this antenna is fully described by the number of turns and the …
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Helical Antenna Optimization Using Genetic Algorithms
The genetic algorithm (GA) is used to design helical antennas that provide a significantly larger bandwidth than conventional helices with the same size. Over the bandwidth of operation, the GA-optimized helix offers considerably smaller axial-ratio and slightly higher gain than the conventional …
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