A telemetry antenna system for unmanned air vehicles

This paper presents a low VSWR high gain telemetry antenna system manufactured for UAVs that provides 360± coverage in the roll plane of the UAV. Proposed telemetry antenna system includes four telemetry antennas, one power divider that has one input and four output terminals which feeds the telemetry antennas with equal magnitude and phase. Proposed high gain telemetry antennas are based on the feeding of the microstrip patch antenna via aperture coupling. Full coverage in the roll plane of the UAV is obtained by using circular array configuration of telemetry antennas. RF power divider is designed by using couple of Wilkinson power dividers with equal line lengths and impedance sections from input terminal to the all four output terminals

Energy Materials: Meeting the Challenge

Track IV: Materials for Energy ApplicationsIncludes audio file (19 min.)Increasing awareness of environmental factors and limited energy resources have led to a profound evolution in the way we view the generation and supply of energy. Although fossil and nuclear sources will remain the most important energy provider for many more years, flexible technological solutions that involve alternative means of energy supply and storage need to be developed urgently. The search for cleaner, cheaper, smaller and more efficient energy technologies has been driven by recent developments where materials technology will play a particularly important role in meeting the needs of the future. The most pronounced breakthroughs are currently taking place for technologies using renewable energy sources. At the same time, the use of these technologies requires reliable and effective ways of storing energy, and exciting developments are occurring in the fields of hydrogen storage, rechargeable batteries, capacitors and high-temperature superconductivity. Among various energy conversion systems, fuel cells are an important enabling technology for the Hydrogen Future and offer cleaner, more-efficient alternatives to the combustion of gasoline and other fossil fuels. Although the potential benefits of hydrogen and fuel cells are significant, many challenges, technical and otherwise, must be overcome before hydrogen and fuel cells will offer a competitive alternative for consumers. These challenges include hydrogen production and delivery, hydrogen storage, fuel cell cost and durability, safety and public acceptance. With regard to energy storage, future electrical and power distribution systems will critically depend on advances in dielectric materials with high energy and power densities. Advanced electric guns and high-power microwave systems will require pulsed power units that store 10- 500 MJ and utilize large-volume capacitors. Since capacitors occupy >70% of the overall volume in conventional power converters, capacitor performance, size, cost, and reliability must be dramatically improved to meet the requirements of current and future energy storage systems. Dielectric permittivity and applied electric field magnitude are key parameters governing capacitor energy density. The applied electric field in a capacitor is significantly lower than the intrinsic dielectric breakdown field, and capacitor energy densities for pulsed power and power electronic capacitors are typically 10 J/cm3 in a fully packaged capacitor, new approaches must be developed to substantially increase intrinsic dielectric energy densities while achieving reliable operation near the dielectric breakdown limit. The presentation will address the recent research activities on the development of solid oxide fuel cell and high energy density capacitor materials at Missouri S&T. On the education site, a course on “Energy Materials” is one of the educational programs offered on the Missouri S&T campus. The objective of this multidisciplinary course is to focus on what materials-based solutions provide and to understand how the rational design and improvement of chemical and physical properties of these materials can lead to energy alternatives that can compete with existing technologies.The presentation will address the recent research activities on the development of solid oxide fuel cell and high energy density capacitor materials at Missouri S&T

Cyclic Regeneration of Nanostructured Composites for Catalytic Applications

A cermet catalyst material, defining a matrix having interconnected open pores, the matrix selected from the group consisting of YSZ and CGO and defining a substrate, a ceramic coating having a general formula AyBnOx at least partially coating the pores, and a plurality of metal particles A at least partially embedded in the ceramic coating. A is selected from the group consisting of Co, Cu, Ce, Ni, Ti, and combinations thereof and B is selected from the group consisting of Mo, W, Ce, and combinations thereof. When the coating is in a first oxidizing atmosphere and at a temperature between 400 degrees Celsius and 800 degrees Celsius the metal particles are absorbed into the coating in the form of metal cations, giving the coating the general formulation AyBnOx. When the coating is in a reducing atmosphere and at a temperature between about 400 degrees Celsius and about 800 degrees Celsius the B metal cations emerge from the coating to yield a plurality of B metal particles at least partially embedded in the coating, wherein the reduced coating has a general formula Ay-zBnOx, wherein y \u3e z and x′ \u3e x

Optimization of aperture coupled microstrip patch antennas

Aperture coupled microstrip patch antennas (ACMPA) are special class of microstrip antennas with high gain and wide impedance bandwidth. These antennas differ from other microstrip antennas with their feeding structure of the radiating patch element. Input signal couples to the radiating patch through the aperture that exists on the ground plane of the microstrip feedline. These special antennas are multilayer stacked type of antennas with so many design variables that will affect the antenna performance. This paper presents the design and optimization procedure of ACMPA while taking care of all possible design variables and parameters to get the highest possible antenna gain and minimum VSWR

Evaluating Pre-Service Teachers’ Design of Mathematical Modelling Tasks

This study aims to examine pre-service teachers’ competencies in designing authentic mathematical modelling tasks. The participants of this study were 22 pre-service teachers enrolled in a mathematical modelling course during their second year in a mathematics teacher education program. The participants designed 20 problems, which were evaluated based on four criteria for mathematical modelling: reality, openness, complexity, and model eliciting. The results indicate that even though the participants were successful in developing problems that had real-world scenarios, only five of them were classified as modelling problems. The majority of the problems fulfilled the reality criterion (12 out of 17); only five of them fulfilled the criteria of openness and model eliciting, and only six of them fulfilled the criterion of complexity. These findings contribute to the importance of supporting teachers’ competencies in the teaching and learning of mathematical modelling for integration into K-12 classrooms

Tailoring spin-orbit torque in diluted magnetic semiconductors

We study the spin orbit torque arising from an intrinsic linear Dresselhaus spin-orbit coupling in a single layer III-V diluted magnetic semiconductor. We investigate the transport properties and spin torque using the linear response theory and we report here : (1) a strong correlation exists between the angular dependence of the torque and the anisotropy of the Fermi surface; (2) the spin orbit torque depends nonlinearly on the exchange coupling. Our findings suggest the possibility to tailor the spin orbit torque magnitude and angular dependence by structural design.Comment: 5 pages, 4 figures. Accepted for publication in Applied Physics Letter