GOx/CNT/Silica Composites for Bioelectrodes

Composites of glucose oxidase (GOx), carbon nanotubes (CNTs), and biologically synthesized silica have been synthesized and tested. These composites are prototypes of biological/electrical interfacial materials and could enable the development of the next generation of devices for a variety of medical, scientific, industrial, and military applications. In particular, it is envisioned that materials based on these prototypes will be integrated into bioelectrodes for biosensors and biofuel cells.

Posted in: Briefs, Materials, Biomaterials, Composite materials, Materials properties, Nanotechnology

Planning Observations by Unmanned Surface Vessels

Three algorithms, and software that implements the algorithms, have been conceived and analyzed as means of effecting automated planning of scientific observations by a fleet of unmanned surface vessels (USVs) equipped with sensors and operating over a large and possibly changing ocean area. Typical observations envisioned in the development of these algorithms include water-temperature measurements ahead of the path of a hurricane (see figure) and fluorometer readings to track harmful algal blooms.

Posted in: Briefs, Information Technology

Progress in Design and Synthesis of Nanostructured Materials

A five-and-a-half-year integrated multidisciplinary research project has been characterized by three themes pertinent to the development of advanced materials having tailorable microstructures and/or nanostructures. These themes are (1) biocompatible nanolithographic methods of patterning and templating of materials to have two- and three-dimensional nanostructures; (2) nucleic-acid-based approaches to preparing (both in solution and from predesigned, nanostructured surface templates) supramolecular structures tailored to perform specific functions; and (3) protein-based or inspired molecular and supramolecular architectures. The contributions of this and other related research projects can be expected to lead to the development of diverse nanostructured organic and inorganic materials and structures, including catalytic peptide tubes, hostguest materials for molecular separations, quantum-dot and magnetic-particle arrays, bio-nanoelectronic circuitry, photonicbandgap and three-dimensional electronic power structures, and novel biowarfare- detection materials.

Posted in: Briefs, Materials, Research and development, Fabrication, Nanomaterials, Nanotechnology

Mixing and Combustion in Turbulent, High-Speed Flows

A collection of reports presents a detailed description of a research program that focused on fundamental investigations of mixing and combustion in turbulent subsonic and supersonic flows like those encountered in high-speed air-breathing aircraft engines. The research included close coordination of effort between experiments and numerical simulations. Recent advances in instrumentation, including some made as part of this program, were utilized in the experiments. The research has been responsible for significant progress in the understanding of molecular mixing in high-speed flows in complicated geometries relevant to scramjet combustors and to high-speed aircraft engines in general. The research included a study oriented toward improving predictions of hydrocarbon flames in such flows and understanding the requirements for combustion of hydrocarbons and holding flames. The study involved comparisons of detailed experiments and detailed predictions of phenomena in stagnation-flame environments that replicate the fundamental effects that influence the stability and extinction of flames. An investigation of the three-dimensional structure of scalar dispersion, with a focus on grid turbulence, has been started and already has yielded new information with relevance to applications of turbulent mixing, including non-premixed combustion and dispersion of pollutants.

Posted in: Briefs, Physical Sciences

Microcompression Tests of a BMG and a Tungsten/BMG Composite

Uniaxial-compression tests of micron-scale specimens (microcompression tests) of a bulk metallic glass (BMG) and of a tungsten/BMG composite have been performed to contribute to understanding of size-dependent mechanical properties of these and other, similar materials. There is increasing interest in fabricating micro- electromechanical systems from BMGs, and in fabricating kinetic-energy (ballistic) penetrators from BMGs and tungsten/ BMG composites. While the mechanical properties and deformation mechanisms of macroscopic, monolithic BMGs in bulk form are generally well understood, these properties are not necessarily equivalent for the BMG alloys cast in composite form or for micron-scale specimens. In a tungsten/BMG composite, dissolution of tungsten in the BMG matrix frequently manifests itself in the formation of complex crystalline phases and the concomitant decrease in the overall amorphous content of the matrix. Hence, it becomes important to compare the properties and deformation mechanisms of the monolithic BMG with those of the BMG as found in the composite accompanied by other phases and heterogeneities.

Posted in: Briefs, Physical Sciences

Kinetic Modeling of Laser-Induced D-T Fusion

A computational- simulation study was performed to assess the feasibility of laser-induced fusion of deuterium nuclei with tritium nuclei as a means of generating neutrons for use in neutron radiography. [D-T fusion reactions produce α particles (He nuclei) plus the desired neutrons.] As in prior studies of laser-induced D-T fusion, the basic idea is to irradiate a small deuterium-and- tritium-containing target with a brief, intense laser pulse that causes a shock wave to propagate into the target. The shock wave ionizes and accelerates a substantial portion of the D and/or T molecules, resulting in, among other phenomena, collisions between D and T nuclei. The question of feasibility is essentially the question of whether, by use of a realistic target and a realistic laser pulse, a sufficient number of ions could be accelerated to sufficient kinetic energy such that the number of resulting D-T fusion reactions would suffice to produce a radiographically usefully large number of neutrons.

Posted in: Briefs, Materials, Computer simulation, Lasers, Forming, Radiation

Techniques for Cooling Power and Other Electronic Devices

All electronic devices generate heat due to their unavoidable internal losses and inefficiencies. The higher the efficiency rating of the device, the less internal heat is generated within it. If we could achieve 100% efficiency, and technology is getting ever closer to that elusive goal, no heat would be generated within the device and, therefore, no cooling would be required. Until then, the generated heat must be dissipated to maximize the end product's reliability and prevent its premature failure.

Posted in: Articles, Articles, Electronics & Computers, Electronic equipment, Power electronics, Cooling

Prototyping PMC Daughterboards

The PMC, or PCI Mezzanine Card, follows the IEEE P1386.1 standard for printed circuit boards. PMCs combine the electrical characteristics of the PCI bus with the mechanical dimensions of the Common Mezzanine Card, or CMC, format. Within the PMC format single PMC boards measure 74mm × 149mm. While the standard also defines a double-sized card, this format is rare. For PMC cards, as defined by the standard, connector configurations can be:

2 bus connectors (P1 and P2) supporting 32-bit PCI signals, 3 bus connectors (P1, P2 and P3) supporting 64 bit PCI signals, and/or 4th bus connector (P4) supporting non-specified I/O signals.
Posted in: Articles, Articles, Electronics & Computers, Architecture, Integrated circuits, Standardization

Touch Screen Technology 101

What makes the iPhone so great? Touch screen technology. Touch screens are changing the way we interact with technology and with iPhone, Apple has opened the floodgates of innovation for the function and design of handheld devices.

Posted in: Articles, Articles, Electronics & Computers, Electronic equipment, Human machine interface (HMI), Displays

The Virtual Becomes Reality at Iowa State University

The colonel has a problem. He has eight unmanned aerial vehicles (UAVs) flying over the outskirts of Baghdad, looking for potential insurgent activity. Are those people he sees moving through the streets insurgents or are they a US infantry patrol? If he alters the flight path of one UAV to loiter over the suspicious activity, how should he deploy the other seven UAVs to pick up the first's original mission? How does he keep track of the positions of the eight UAVs, what they are seeing, and the locations of nearby US troops, all in real-time?

Posted in: Application Briefs, Application Briefs, Electronics & Computers, Virtual reality, Human machine interface (HMI), Defense industry, Unmanned aerial vehicles