Inverter ratio failure detector

A failure detector which detects the failure of a dc to ac inverter is disclosed. The inverter under failureless conditions is characterized by a known linear relationship of its input and output voltages and by a known linear relationship of its input and output currents. The detector includes circuitry which is responsive to the detector's input and output voltages and which provides a failure-indicating signal only when the monitored output voltage is less by a selected factor, than the expected output voltage for the monitored input voltage, based on the known voltages' relationship. Similarly, the detector includes circuitry which is responsive to the input and output currents and provides a failure-indicating signal only when the input current exceeds by a selected factor the expected input current for the monitored output current based on the known currents' relationship

Potential application of artificial concepts to aerodynamic simulation

The concept of artificial intelligence as it applies to computational fluid dynamics simulation is investigated. How expert systems can be adapted to speed the numerical aerodynamic simulation process is also examined. A proposed expert grid generation system is briefly described which, given flow parameters, configuration geometry, and simulation constraints, uses knowledge about the discretization process to determine grid point coordinates, computational surface information, and zonal interface parameters

Summary of Coral Cay Conservation's habitat mapping data from Utila, Honduras

IIThe coral reefs of Honduras are of vital national and international importance,both ecologically and economically, but are threatened because of rapid economicand population growth.? During work on Utila between 1999 and 2000 (the ?Bay Islands 2000? project),Coral Cay Conservation developed a programme of surveys, training andconservation education aimed at assessing the status of local reefs and improvingenvironmental awareness amongst neighbouring communities.? This summary report provides an overview of the habitat mapping data collectedby the Bay Islands 2000 project.? CASA provided software, hardware and skills, on a charitable basis to ensure thatthe data collected by CCC could be developed into a GIS, not only for mappingthe status of the coral reefs of Honduras, but also to provide analysis of the aerialextent of these reefs.? Data were collected within individual ?study areas?, to facilitate analysis at a rangeof spatial scales, and utilised the CCC standard baseline survey technique for therapid assessment of the characteristics of reef communities. The surveys,therefore, utilised a series of transects, perpendicular to the reef.? Baseline transects discriminated nine benthic and six geomorpholgical classeswhich indicates Utila has a high habitat diversity. Habitat diversity is importantsince the number of habitat types has been shown to be a good representation ofspecies biodiversity.? The nine benthic classes that were distinguished were all relatively coral poorbecause of a suite of relatively long-term local and regional factors, exacerbatedby the combination of Hurricane Mitch and coral bleaching in 1995 and 1998.? Damselfish were the most abundant reef associated fish recorded during baselinetransect surveys. Commercially important fish were less abundant that wouldnormally be expected in unfished systems.? A recurring pattern in the baseline transect data was the greater abundance anddiversity of fish in coral rich classes. However, although the link between fishabundance and coral cover was clear, not all species were necessarily mostabundant in the most coral rich areas.? Invertebrates were generally uncommon, partly because of fishing pressure, andthe abundances of many invertebrate taxa were correlated with coral cover.? A habitat map is presented within this report as an indication of the distribution ofhabitat types around Utila.? Using the map, estimates of areal extents of each benthic class and habitat type areinstructive. For example, there is only approximately 27 km2 of reefal habitatsaround Utila. Furthermore, the area supporting the most coral rich benthic classesis only approximately 4 km2 (15%). These statistics both highlight the damagecaused by the bleaching event and Hurricane Mitch and other anthropogenicimpacts and the need to conserve remaining coral rich areas.? If further reserves were to be created, it would be important to try to protect arange of reef and habitat types. For this reason, it appears that the Turtle HarbourWildlife Refuge is well placed since this areas includes a wide range of habitattypes. However, placement of reserves in Utila should favour relatively coral richhabitats over sand dominated areas.? This study led to six recommendations:Summary Utila habitat mapping reportIII? One or more agencies should collect additional ground-truthing data fromaround Utila to facilitate both classification of currently ?Unknown? polygonsand an accuracy assessment of the map.? Establish an integrated GIS and associated meta-database for Utila, includingdata from the Bay Islands 2000 project.? Examine the potential of using data collected by the Bay Islands 2000 projectas the basis of national habitat classification scheme and subsequent nationalhabitat map.? Continue to aim to establish one or more additional multiple use marineprotected areas around Utila, with an integrated monitoring programme tomeasure their efficacy, and strengthen the enforcement of regulations in theTurtle Harbour Wildlife Sanctuary. Establish regulations, and enforce existinglegislation, to minimise the detrimental effects of coastal development on reefhealth.? Additional marine reserves in Utila should integrate factors such as thepreference of many fish species for coral rich habitats and the protection ofareas incorporating a range of habitat types, including mangroves and seagrassbeds, in order to allow for nursery areas, ontogenetic shifts and species thatrely on non-coral rich habitats. The corollary of the preference of fish speciesfor coral rich habitats is to protect coral cover within the reserves.? The reef on the south coast of Utila appears to be a good candidate forprotection because it is relatively sheltered from storm and hurricane damage

Chiral discrimination in optical binding

The laser-induced intermolecular force that exists between two or more particles in the presence of an electromagnetic field is commonly termed “optical binding.” Distinct from the single-particle forces that are at play in optical trapping at the molecular level, the phenomenon of optical binding is a manifestation of the coupling between optically induced dipole moments in neutral particles. In other, more widely known areas of optics, there are many examples of chiral discrimination—signifying the different response a chiral material has to the handedness of an optical input. In the present analysis, extending previous work on chiral discrimination in optical binding, a mechanism is identified using a quantum electrodynamical approach. It is shown that the optical binding force between a pair of chiral molecules can be significantly discriminatory in nature, depending upon both the handedness of the interacting particles and the polarization of the incident light, and it is typically several orders of magnitude larger than previously reported