Cryogenic flux-concentrator

Flux concentrator has high primary to secondary coupling efficiency enabling it to produce high magnetic fields. The device provides versatility in pulse duration, magnetic field strengths and power sources

Scene simulation for passive IR systems

The development of large mosaic detector arrays will allow for the construction of staring long wave infrared (LWIR) sensors which can observe large fields of view instantaneously and continuously. In order to evaluate and exercise these new systems, it will be necessary to provide simulated scenes of many moving targets against an infrared clutter background. Researchers are currently developing a projector/screen system. This system is comprised of a mechanical scanner, a diffuse screen, and a miniature blackbody. A prototype of the mechanical scanner, which is comprised of four independently driven scanners, has been designed, fabricated, and evaluated under room and cryogenic vacuum conditions. A large diffuse screen has been constructed and tested for structural integrity under cryogenic/vacuum thermal cycling. Construction techniques have been developed for the fabrication of miniature high-temperature blackbody sources. Finally, a concept has been developed to use this miniature blackbody to produce a spectrally tailorable source

AVIRIS data characteristics and their effects on spectral discrimination of rocks exposed in the Drum Mountains, Utah: Results of a preliminary study

Airborne Visible and Infrared Imaging Spectrometer (AVIRIS) data collected over a geologically diverse field site and over a nearby calibration site were analyzed and interpreted in efforts to document radiometric and geometric characteristics of AVIRIS, quantify and correct for detrimental sensor phenomena, and evaluate the utility of AVIRIS data for discriminating rock types and identifying their constituent mineralogy. AVIRIS data acquired for these studies exhibit a variety of detrimental artifacts and have lower signal-to-noise ratios than expected in the longer wavelength bands. Artifacts are both inherent in the image data and introduced during ground processing, but most may be corrected by appropriate processing techniques. Poor signal-to-noise characteristics of this AVIRIS data set limited the usefulness of the data for lithologic discrimination and mineral identification. Various data calibration techniques, based on field-acquired spectral measurements, were applied to the AVIRIS data. Major absorption features of hydroxyl-bearing minerals were resolved in the spectra of the calibrated AVIRIS data, and the presence of hydroxyl-bearing minerals at the corresponding ground locations was confirmed by field data

Carbon-13 and proton nuclear magnetic resonance analysis of shale-derived refinery products and jet fuels and of experimental referee broadened-specification jet fuels

A proton and carbon-13 nuclear magnetic resonance (NMR) study was conducted of Ashland shale oil refinery products, experimental referee broadened-specification jet fuels, and of related isoprenoid model compounds. Supercritical fluid chromatography techniques using carbon dioxide were developed on a preparative scale, so that samples could be quantitatively separated into saturates and aromatic fractions for study by NMR. An optimized average parameter treatment was developed, and the NMR results were analyzed in terms of the resulting average parameters; formulation of model mixtures was demonstrated. Application of novel spectroscopic techniques to fuel samples was investigated

LIVESTOCK PRICING IN THE NORTHERN KENYAN RANGELANDS

This paper uses detailed, transactions-level data and a structural-heteroskedasticity-in-mean model to identify the determinants of livestock producer prices for pastoralists in the drylands of northern Kenya. The empirical results confirm the importance of animal characteristics, periodic events that predictably shift local demand or supply, and especially rainfall on the prices pastoralists receive for animals. Price risk premia are consistently negative in these livestock markets. The imposition of quarantines has a sharp negative effect on expected producer prices in the pastoral areas, revealing a distributionally regressive approach to animal disease control in Kenya.Demand and Price Analysis, Livestock Production/Industries,

Promoting independent learning skills using video on digital language laboratories

This is the author's PDF version of an article published in Computer assisted language learning ©2006. The definitive version is available at http://www.informaworld.com/The article discusses the potential for developing independent learning skills using the digital language laboratory with particular reference to exploiting the increasingly available resource of digital video. It investigates the potential for recording and editing video clips from online sources and digitalising clips from analogue recordings and reflects on the current status quo regarding the complex copyright regulations in this area. It describes two pilot self-access programmes based on video clips which were undertaken with University College Chester undergraduates and reflects on the value of the experience for students in developing a wide range of language skills as well as independent learning skills using their feedback on the experience

The volatile acid production of starters and of organisms isolated from them

The introduction of starters represents one of the distinct advances made in the field of dairying. Altho starters have been widely used their careful study has been very much neglected and the men who handle them extensively are often unable to explain the results obtained. The increasing use that is being made of starters in the manufacture of butter, various types of cheese, and fermented milk drinks makes it essential that they be studied with the idea of securing information regarding the reasons for the variations that occur in the quality. The present paper gives the results secured in a study of the volatile acid production of starters and of cultures of the bacteria isolated from them