Progress in rapid detection and identification of unknown human and agricultural pathogens

The medical industry is driving pathogen detection technology from its present characteristics of 50/sample, 100 sample capability systems, with several day time responses, having several percent error rates in reported outcomes. The systems described above are capable of providing samples at < 5/test, managing several million samples, &lt; 1-hour cycle times, (or just minutes in some cases) and &lt; 0.1% error rates. Because of their importance to the medical and agricultural communities, all ''important'' pathogens will have detection kits available (within air transport times, anywhere in the world) by 2020, and the most well known pathogens will have kits available within a few years. Many are available now. Because of the importance of the food supply to modern nations, these technologies will be employed everywhere in this industry. For example, the United States imports 30 B tons of food a year, but inspects &lt; 1%. Portable inspection systems will make it possible to test for dangerous pathogens in feed lots, food processing plants, markets, and points of use. Outbreaks of animal or plant disease will be immediately detectable using field instrumentation, and more complex samples can be sent to central testing laboratories where more sophisticated test systems will be available. Unusual pathogens either naturally or purposefully selected or developed, will require special attention because there is not a commercial economic driver for the development of detection systems and curative agents. Their development, and production for sufficient availability, will require significant investments by the world community. The strategy and costs for developing vaccines or curative drugs will be very expensive and will need special attention. However it is important that attention be directed to these problems because such attention has a strong deterrent effect on potential developers or users. The capacity to use the full information content contained in pathogen systems, such as their full genomic information, can be very helpful in identifying malevolent users. In addition, it is undoubtedly true that an understanding of replication and human or other sensitivity to pathogens will improve our medical understanding of human health in general

Nova: the laser fusion breakeven experiment

A new laboratory building is being constructed adjacent to the Shiva laser to house the Phase I $137M ten-beam Nova laser and a target chamber designed for twenty beams. The first ten beams will be operational in early 1980. Following Phase I, it is planned that the Shiva laser will be shut down and upgraded into ten Nova laser beams. These beams will then be combined with Nova Phase I beams to provide the full twenty beams having a minimum output energy of 300 kJ in a 3 nc pulse, or a power capability of 300 terawatts (10/sup 12/ watts) in a 100 ps pulse. This paper will describe the Phase I engineering project

Ultraefficient Thermophotovoltaic Power Conversion By Band-Edge Spectral Filtering

Thermophotovoltaic power conversion utilizes thermal radiation from a local heat source to generate electricity in a photovoltaic cell. It was shown in recent years that the addition of a highly reflective rear mirror to a solar cell maximizes the extraction of luminescence. This, in turn, boosts the voltage, enabling the creation of record-breaking solar efficiency. Now we report that the rear mirror can be used to create thermophotovoltaic systems with unprecedented high thermophotovoltaic efficiency. This mirror reflects low-energy infrared photons back into the heat source, recovering their energy. Therefore, the rear mirror serves a dual function; boosting the voltage and reusing infrared thermal photons. This allows the possibility of a practical \u3e50% efficient thermophotovoltaic system. Based on this reflective rear mirror concept, we report a thermophotovoltaic efficiency of 29.1 ± 0.4% at an emitter temperature of 1,207 °C

Direct and indirect measures of speech articulator motions using low power EM sensors

ABSTRACT Low power Electromagnetic (EM) Wave sensors can measure general properties of human speech articulator motions, as speech is produced. See Holzrichter, Burnett, Ng, and Lea, J.Acoust.Soc. Am. 103 (1) 622 (1998). Experiments have demonstrated extremely accurate pitch measurements (&lt; 1 Hz per pitch cycle) and accurate onset of voiced speech. Recent measurements of pressure-induced tracheal motions enable very good spectra! and amplitude estimates of a voiced excitation function. The use of the measured excitation tinctions and pitch synchronous processing enable the determination of each pitch cycle of an accurate transfer function and, indirectly, of the corresponding articulator motions. In addition, direct measurements have been made of EM wave reflections from articulator interfaces, including jaw, tongue, and palate, simultaneously with acoustic and glottal open/close signals. While several types of EM sensors are suitable for speech articulator measurements, the homodyne sensor has been found to provide good spatial and temporal resolution for several applications

Preheat Effects on Microballoon Laser-Fusion Implosions

Nonequilibrium hydroburn simulations of early laser-driven compression experiments indicate that low energy photons from the vicinity of the ablation surface are preheating the microballoon-pushers, thereby severely limiting the compressions achieved (similar degradation may result from 1 to 4 percent energy deposition by superthermal electrons). This implies an 8- to 27-fold increase in the energy requirements for breakeven, unless radiative preheat can be drastically reduced by, say, the use of composite ablator-pushers. (auth

Lawson criterion for ignition exceeded in an inertial fusion experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion

Use of low power EM radar sensors for speech articulator measurements

Very low power electromagnetic (EM) wave sensors are being used to measure speech articulator motions such as the vocal fold oscillations, jaw, tongue, and the soft palate. Data on vocal fold motions, that correlate well with established laboratory techniques, as well as data on the jaw, tongue, and soft palate are shown. The vocal fold measurements together with a volume air flow model are being used to perform pitch synchronous estimates of the voiced transfer functions using ARMA (autoregressive moving average) techniques. 6 refs., 5 figs

Shiva laser system performance

On November 18, 1977, after four years of experimentation, innovation, and construction, the Shiva High Energy Laser facility produced 10.2 kJ of focusable laser energy delivered in a 0.95 ns pulse. The Shiva laser, with its computer control system and delta amplifiers, demonstrated its versatility on May 18, 1978, when the first 20-beam target shot with delta amplifiers focused 26 TW on a target and produced a yield of 7.5 x 10/sup 9/ neutrons