Finite-Element Simulations of Field and Current Distributions in Multifilament Superconducting Films

The separation of high-temperature superconducting (HTS) tapes in filaments is a viable approach to reduce AC losses in HTS high-power applications, where AC currents and/or fields may be applied in addition to any DC field present. Methods such as mechanical, laser scribing, photolithography, or direct printing on buffered substrates using inkjet deposition have been used to create the filaments in the second-generation HTS coated conductors in order to reduce hysteretic losses. However, losses of the finely striated tapes can still be noticeably larger than predicted by analytical expressions, due to the addition of coupling currents or lack of field penetration, and such deviation tends to grow with increasing filament density. In order to reduce the magnetic coupling between filaments and the associated AC losses, an in-depth understanding of flux and current dynamics in the multifilamentary HTS, in realistic conditions, is required.

Posted in: Briefs, Electronics & Computers, Finite element analysis, Electromagnetic compatibility, Voltage regulators, Conductivity

Nozzles for Focusing Aerosol Particles

Several nozzles have been designed to aerodynamically focus aerosol particles into a small-diameter jet, so that individual particles can be illuminated by a laser beam and their light scattering and/or laser-induced fluorescence (LIF) spectra can be measured. An additional nozzle can aerodynamically puff selected particles out of the airstream so that they can be sorted and collected.

Posted in: Briefs, Mechanical Components, Nozzles, Test procedures, Aerodynamics

Parallel Hybrid Vehicles Using Fuzzy Logic Control

A fuzzy logic controller for hybrid vehicles with parallel configuration was proposed. Using the state-of-charge (SOC) of the energy storage, the driver command, and the motor/generator speed, a set of rules was developed. The fuzzy logic controller can determine the split between the electric motor and the internal combustion engine to achieve better fuel economy and low emission performance without losing vehicle performance.

Posted in: Briefs, Mechanical Components, Fuzzy logic, Architecture, Hybrid electric vehicles, Vehicle performance

Development of an Electrochemical Biosensor for Organophosphate Chemicals

Detection of organophosphate (OP) compounds has attracted much attention in terms of safeguarding human health, owing to their frequent use as pesticides in agriculture and their potential use as chemical warfare agents. Among a variety of biological methods based on the biocatalytic activity of organophosphorus hydrolase (OPH), amperometric, potentiometric, and optical biosensing devices have been developed for detecting OPs. Electrochemical biosensors in particular have been widely investigated to monitor various pesticides including OP compounds such as paraoxon, parathion, sarin, and soman via an enzyme-catalyzed hydrolysis reaction by OPH due to their fast speed, high efficiency, low cost, and small sample size.

Posted in: Briefs, Physical Sciences, Sensors and actuators, Volatile organic compounds, Medical, health, and wellness

Novel Active Transient Cooling Systems

Energy-efficient cooling technology is extremely important in today’s society, considering the need for energy conservation and the urgent need to mitigate global warming. Near-room-temperature magnetic refrigeration is an emerging cooling technology that has several advantages compared to conventional gas-compression technology. It utilizes the magnetocaloric effect (MCE) in which heating and cooling of a magnetocaloric material (MCM) is induced by a varying external magnetic field. The magnetocaloric effect (the temperature change of a magnetic material due to the application of an external magnetic field) is the cornerstone of magnetic cooling.

Posted in: Briefs, Physical Sciences, Energy conservation, Cooling, Magnetic materials

Diode Laser Sensor for Scramjet Inlets

The supersonic combustion ramjet (scramjet) engine is one of the more promising high-speed flight propulsion technologies. One of the reasons for this is the simplicity of the engine design, having no moving parts and requiring no external ignition source, and the fact that scramjets do not need to provide their own oxidizer. Despite this simplicity, several obstacles to the use of scramjet propulsion systems have become apparent, including the ability to produce sufficient fuel-air mixing at high speed, large total pressure losses, reduction in specific impulse with increasing flight Mach number, and the sensitivity of combustion to inlet temperature. This last problem can be very significant.

Posted in: Briefs, Physical Sciences, Lasers, Sensors and actuators, Combustion and combustion processes, Scramjet engines

MALDI-MSI Imaging of Latent Fingerprints

For years, forensic scientists have been seeking new methods to improve existing techniques for the visualization of latent fingerprints. The structured combination of optical methods (diffused reflection, luminescence, UV absorption and reflection), physical methods (powdering, vacuum metal deposition, small particle reagent), physico-chemical methods (physical developer, multi-metal-deposition, iodine, cyanoacrylate), and chemical methods (ninhydrin and its analogues, DFO, etc.), permits a highly efficient processing of the secretions deposited by the fingers on a great variety of substrates. To visualize these developed fingerprints, alternative light sources or laser-based detection methods are commonly used. However, like all other existing techniques, these optical methods do not work in all possible cases, and certain types of latent fingerprints or object surfaces with unique characteristics may be problematic.

Posted in: Briefs, Physical Sciences, Imaging, Lasers, Optics, Spectroscopy, Identification

Compressive Oversampling for Robust Data Transmission in Sensor Networks

A paper discusses recent developments in the area of Compressive Sensing (CS) for data loss in wireless sensing applications. Since many physical signals of interest are known to be sparse or compressible, employing CS not only compresses the data and reduces the effective transmission rate, but also improves the robustness of the system to channel erasures. This is possible because reconstruction algorithms for compressively sampled signals are not hampered by the stochastic nature of wireless link disturbances, which has traditionally plagued attempts at proactively handling the effects of these errors.

Posted in: Briefs, Physical Sciences, Mathematical models, Data exchange, Wireless communication systems, Reliability

Video Camera

Goodrich Corp.’s ISR Systems Princeton (Princeton, NJ) has introduced the SU640HSX mil-hardened, indium gallium arsenide (InGaAs) shortwave infrared (SWIR) uncooled video camera for military imaging systems and covert surveillance. The camera features a 640 × 512 pixel format with a 25-micron pitch, dynamic range enhancements, expanded configuration memory, and an operating temperature range from -40 to 70 °C. The camera can image through atmospheric obscurants such as fog, haze, and smoke.

Posted in: Products

Using Parallel Processing on GPUs to Accelerate Finite-Difference Time-Domain Algorithms for Electromagnetic and Seismic Applications

Many scientific, technical and engineering applications in finance, medical imaging, modeling, simulation, and image processing can benefit greatly from the floating point acceleration offered by modern general purpose graphics processing units (GPGPU). Today’s graphics processors have evolved into sophisticated, massively-parallel, highly-programmable compute engines ideally suited for algorithms with a high degree of data parallelism. Combined with modern parallel programming languages and application interfaces such as industry standard OpenCL™, GPGPU offers a new paradigm for high-performance computing (HPC).

Posted in: Articles, Articles, Electronics & Computers, Mathematical models, Architecture, Displays