6,380 research outputs found
Quadruplex digital flight control system assessment
Described are the development and validation of a double fail-operational digital flight control system architecture for critical pitch axis functions. Architectural tradeoffs are assessed, system simulator modifications are described, and demonstration testing results are critiqued. Assessment tools and their application are also illustrated. Ultimately, the vital role of system simulation, tailored to digital mechanization attributes, is shown to be essential to validating the airworthiness of full-time critical functions such as augmented fly-by-wire systems for relaxed static stability airplanes
The economic ecology of small businesses in Oxfordshire
Report by the Oxfordshire Economic Observatory (OEO) for the Federation of Small Businesses (FSB), Oxfordshire Branch
The Role of Water Quality Perceptions in Modeling Lake Recreation Demand
Recreation demand models typically incorporate measures of the physical attributes of recreational sites; e.g., Secchi depth or phosphorous levels in case of water quality. Moreover, most studies show that individuals do respond to these physical characteristics in choosing where to recreate. However, the question remains as to whether the available physical measures accurately capture individual perceptions of water quality and if there is a additional role to be played by elicited perception measures in modeling recreation demand. In this paper, we use data from the 2004 Iowa Lakes Survey to model recreation demand as a function of both the physical water quality at 131 lakes in the state and household perceptions of lake water quality. In general, water quality perceptions are correlated with the available physical measures, but not perfectly so, and both actual and perceived water quality are found to significantly impact recreational site choice.
On magnetic structure of CuFe2Ge2: constrains from the 57Fe Mossbauer spectroscopy
57Fe Mossbauer spectroscopy measurements were performed on a powdered
CuFe2Ge2 sample that orders antiferromagnetically at ~ 175 K. Whereas a
paramagnetic doublet was observed above the Neel temperature, a superposition
of paramagnetic doublet and magnetic sextet (in approximately 0.5 : 0.5 ratio)
was observed in the magnetically ordered state, suggesting a magnetic structure
similar to a double-Q spin density wave with half of the Fe paramagnetic and
another half bearing static moment of ~ 0.5 - 1 mu_B. These results call for a
re-evaluation of the recent neutron scattering data and band structure
calculations
Beebots-a-lula, Where's My Honey?: Design Fictions and Beekeeping
The honey bee is a powerful cultural motif that remains an important symbol for the future. Their role as pollinators, alongside a myriad of other species, is critical to the continued diets of humankind. This Future Scenario explores a possible near future where human intervention poses new risks to their survival. Drawing on folklore and contemporary beekeeping practices, Mr Shore's Downfall tells a tale of discovery and loss as a young beekeeper is introduced to the world of honey bees. Three imagined artefacts are revealed through the story and discussed with consideration of their cultural context, desirability and relation to socio-economic factors. Themes from Mr Shore's Downfall are examined, and the potential of writing practice for design fiction practitioners is considered
Bonding machine for forming a solar array strip
A machine is described for attaching solar cells to a flexable substrate on which printed circuitry has been deposited. The strip is fed through: (1) a station in which solar cells are elevated into engagement with solder pads for the printed circuitry and thereafter heated by an infrared lamp; (2) a station at which flux and solder residue is removed; (3) a station at which electrical performance of the soldered cells is determined; (4) a station at which an encapsulating resin is deposited on the cells; (5) a station at which the encapsulated solar cells are examined for electrical performance; and (6) a final station at which the resulting array is wound on a takeup drum
Valuing Water Quality As a Functionof Water Quality Measures
This paper incorporates a rich set of physical water quality attributes, as well as site and household characteristics, into a model of recreational lake usage in Iowa. Our analysis shows individuals are responsive to physical water quality measures. Willingness-to-pay estimates are reported based on improvements in these measures.
The iconography of Asphyxiophilia: From fantasmatic fetish to forensic fact
This is a post print version of the article. The official published version can be accessed from the link below
The resistivity and microstructure of heavily drawn Cu‐Nb alloys
A combined resistivitytransmission electron microscopy(TEM) study has been done on heavily drawn Cu‐20 vol % Nb alloys (so‐called i n s i t u alloys). The results show that electron scattering at Cu‐Nb interfaces makes the major contribution to resistivity in heavily drawn wire. The dislocation contribution is small and constant at deformation strains greater than around 4, apparently as a result of dynamic recovery/recrystallization of the Cu matrix which occurs during room‐temperature drawing. Results of this study and other recent TEM dislocation studies indicate that the dislocation density in heavily drawn Cu‐20 vol % Nb material does not exceed 101 1 cm− 2. It is demonstrated here that the 101 3‐ cm− 2 dislocation density predicted by the resistivity study of Karasek and Bevk [J. Appl. Phys. 5 2, 1370 (1981)] is high because the interface scattering contribution is more strongly reduced by coarsening than they assumed. It is shown that resistivitymeasurements provide a means of evaluating an average Cu channel diameter in the aligned composite alloys formed at large deformation strains
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