We have recently proposed a new concept for deployable reflectors consisting of a thin parabolic carbon-fibre-reinforced-plastic (CFRP) shell stiffened along the edge by an elastically collapsible stiffener. Here we show that a stiffener accounting for less than 10% of the total mass of the reflector increases the stiffness of the softest deformation mode of the deployed reflector by 48 times, ...

This paper reports on the design and implementation of high efficiency, nonmetallic reflectors integrated on the sidewalls of micromachined cavities. Due to shadowing from deposition within a cavity, significant variation in the thicknesses of the dielectric thin films composing the reflectors are encountered when the layers are deposited by Plasma Enhanced Chemical Vapor Deposition (PECVD). Th...

using qcd factorization for the hadronic matrix elements, we show that existing data, inparticular the branching ratios br ( b →j/ψk) and br ( b →j/ψπ), can be accounted for in this approach.we analyze the decay b j /k( ) within the framework of qcd factorization. the calculation of therelevant hard-scattering kernels for twist-2 and twist-3 is completed. we calculate this decay in a special...

Acoustic bottom-interacting measurements from the Shallow Water '06 experiment experiment (frequency range 1-20 kHz) are presented. These are co-located with coring and stratigraphic studies showing a thin (approximately 20 cm) higher sound speed layer overlaying a thicker (approximately 20 m) lower sound speed layer ending at a high-impedance reflector (R reflector). Reflections from the R ref...

To create a next-generation mobile satellite communication system that offers large communication capacity, the onboard antenna system must be a multi-beam system consisting of a light weight 20-m class reflector and a light weight 100-beam class antenna feed system. We clarify that the antenna gain decrease created by the reflector surface distortion in orbit is relatively large. This paper pr...

We review recent studies demonstrating a nonuniversal (continuously variable) survival exponent for history-dependent random walks, and analyze a new example, the hard movable partial reflector. These processes serve as a simplified models of infection in a medium with a history-dependent susceptibility, and for spreading in systems with an infinite number of absorbing configurations. The memor...

This paper presents a new deployable reflector concept for an Earth observation mission that requires a low-cost L-band Synthetic Aperture Radar (SAR) instrument with a large aperture. A novel “hollow solid” structural concept is proposed that comprises curved surfaces formed from thin sheets of carbon-fiber-reinforced-plastic connected by flexible hinges along the edges. The front surface of t...

This paper describes a constructive procedure aimed at developing a CAD/CAE/ CAM system for designing the reflector of an automobile headlight for a given light intensity distribution on the target (road), considering the styling of modern passenger cars. A design concept is described in which the reflector alone produces the specified illumination pattern. Consider a reflector system consistin...

Cassegrain Reflector Antenna Design consists of various effects caused by blockage and its effect on overall performance. The design for minimum blockage condition results in geometry that offers lower amount of blockage and increased spillover past the subreflector. To avoid this, optimized design of the antenna results in geometry that offers lower amount of spillover past the edges of the ma...

Vortex extrusion (VE) is a severe plastic deformation technique which is based on the synergies between high strain accumulation and high hydrostatic pressure. Such a high amount of pressure, places a mandate to seek the method for investigation of the load under processing conditions. For this, kinematically admissible velocity field and upper bound terms based on Bezier formulation are develo...