Remote Monitoring of Emissions using On-Vehicle Sensing and Vehicle to Roadside Communications

Recent developments in on-vehicle electronics makes practical remote monitoring of vehicle emissions compliance with CARB and EPA regulations. A system consisting of emission controls malfunction sensors, an on-board computer (OBC), and vehicle-to-roadside communications (VRC) would enable enforcement officials to remotely and automatically detect vehicle out-of-compliance status. Remote sensing could be accomplished at highway speeds as vehicles pass a roadside RF antenna and reader unit which would interrogate the on- vehicle monitoring and recording system. This paper will focus on the hardware system components require to achieve this goal with special attention to the VRC; a key element for remote monitoring. this remote sensing concept piggybacks on the development of inexpensive VRC equipment for automatic vehicle identification for electronic toll collection and intelligent transportation applications. Employing an RF transponder with appropriate interface to the OBC and malfunction sensors, a practical monitoring system can be developed with potentially important impact on air quality and enforcement. With such a system in place, the current -- and costly and ineffective -- emission control strategy of periodic smog checking could be replaced or modified

Drum vortons in high density QCD

Recently it was shown that high density QCD supports of number of topological defects. In particular, there are U(1)_Y strings that arise due to K^0 condensation that occurs when the strange quark mass is relatively large. The unique feature of these strings is that they possess a nonzero K^+ condensate that is trapped on the core. In the following we will show that these strings (with nontrivial core structure) can form closed loops with conserved charge and currents trapped on the string worldsheet. The presence of conserved charges allows these topological defects, called vortons, to carry angular momentum, which makes them classically stable objects. We also give arguments demonstrating that vortons carry angular momentum very efficiently (in terms of energy per unit angular momentum) such that they might be the important degrees of freedom in the cores of neutron stars.Comment: 11 pages, accepted for publication in Physical Review

Global Strings in High Density QCD

We show that several types of global strings occur in colour superconducting quark matter due to the spontaneous violation of relevant U(1) symmetries. These include the baryon U(1)_B, and approximate axial U(1)_A symmetries as well as an approximate U(1)_S arising from kaon condensation. We discuss some general properties of these strings and their interactions. In particular, we demonstrate that the U(1)_A strings behave as superconducting strings. We draw some parallels between these strings and global cosmological strings and discuss some possible implications of these strings to the physics in neutron star cores.Comment: LaTeX JHEP-format (26 pages) Option in source for REVTeX4 forma

Potato nutritional management changes and challenges into the next century

Plant nutrients are important components of the intensive production system used for potatoes. Nutrient management practices need to be improved for sustained and increased productivity. Better mangement decisions will be made when accurate information is available about (a) crop residues and rotation effects on nutrient cycling, (b) the nutritional characteristics and requirements of each variety, (c) bioavailability of nutrients in soils, and (d) fertilization and tillage effects on nutrient-use efficiencies. Plant growth and nutrient uptake responses to different nutrient availabilities must also be understood to maximize growth and nutrient efficiencies. Diagnostic management techniques for nutrients need to be related to fundamental chemical and biological processes in the soil and plant system to be applicable to different environments. This information can then be packaged with other knowledge into a comprehensive crop management system. These changes should bring our agronomic practices into better harmony with the natural processes of the production system, and yet be responsive to social and environmental concerns, and economic reality

Temporal multiplexing for economical measurement of power versus time on NIF

The researchers have designed an economical device to measure the power time history in the National Ignition Facility`s (NIF) 192 beam laser. The heart of the system is a commercial, high-speed, four-channel digitizer with a 15,000 point record length. Samples of several beams are taken with fiberoptic pickoffs, separated in time with appropriate fiberoptic delays and presented to high-speed vacuum photodiodes, which convert the samples to electrical signals for the digitizer. Amplitude and time multiplexing are used to cover the required dynamic range and to record 12 samples on the digitizer, making the cost per sample competitive with alternative approaches. Forty-eight digitizers can record the required three samples from each of the 192 beams. An additional similar but lower bandwidth system is used to record the backreflected light from the main laser amplifiers and elsewhere. The recording electronics are discussed in detail