Achieving accurate FTIR measurements on high performance bandpass filters

The sources of ordinate error in FTIR spectrometers are reviewed with reference to measuring small out-of-band features in the spectra of bandpass filters. Procedures for identifying instrumental artefacts are described. It is shown that features well below 0.01%T can be measured reliably

Cooled Infrared Dichroic Beamsplitters and Filters for the MIRI Spectrometer and Imager (5-29µm)

The spectral design and fabrication of cooled (7K) mid-infrared dichroic beamsplitters and bandpass filter coatings for the MIRI spectrometer and imager are described. Design methods to achieve the spectral performance and coating materials are discussed

Effects of strontium content on the microstructure and ionic conductivity of samarium-doped ceria

We thank the School of Chemistry, University of St Andrews for a PhD studentship for TS.Due to its high oxygen ion conductivity at elevated temperatures, samarium-doped ceria (SDC) is a very promising material for application in solid state electrochemical devices and especially in the electrolytes of solid oxide fuel cells. Several prior studies have reported a further improvement in the ionic conductivity of SDC on doping with small amounts of strontium. It is suggested that strontium acts as a sintering aid—improving the microstructure of SDC—and as a scavenger of silicon impurities, decreasing its tendency to form resistive phases at grain boundaries. However, because of the range of preparation methods and the resulting differences in microstructure and silicon levels, some inconsistencies exist in the literature. Furthermore, the effect of strontium on the intrinsic (bulk) conductivity of SDC is not often discussed. To address these issues, a systematic, combined microstructural and conductivity study has been performed on a compositional series with a range of strontium contents, Ce0.8−xSm0.2SrxO2−δ (x = 0, 0.002, 0.005, 0.01, 0.02, 0.03, 0.04). A low temperature synthesis affording products with low silicon was employed. Total bulk and grain boundary conductivity data were obtained over a wide temperature range. Increasing strontium content caused a general decrease in total and intrinsic conductivity, but there was an improvement in grain boundary conductivity at the lowest strontium levels. These results were interpreted by reference to the microstructures using, among other parameters, the blocking, and normalised blocking, factors.Publisher PDFPeer reviewe

A New Outcrop of the Rockville Conglomerate

During the summer of 1953, an outcrop of ferruginous pebble conglomerate was found in central Jones county, Iowa. This outcrop is located about three miles north of the town of Olin, along the eastern edge of Iowa Highway 38 between Olin and the junction of Highways 38 and 64. It is near the center of the SE¼ of section 25, T. 84 N., R. 3W. (Jackson Township) Jones County. Topographically, it occurs about midway up the gentle north side of the valley of the Wapsipinicon River. The rock at this locality extends horizontally for about thirty feet and has about five feet of its thickness exposed. Along the tops of the exposed bedding planes, weathering has produced a mottled black-gray color. On fresh surfaces and on some of the vertical fractures, the rock is light-gray, pale yellow-brown, or dull-red in color

Repositioning the Culture of Power: Advocating for Systemic Change in Public Affairs Education

The present study sets out to characterize and analyze difficulties that typically face faculty of color who teach at Predominantly White Institutions (PWIs). Using personal narratives of junior faculty at a PWI, we explore the themes of shifting identity and marginality for faculty of color as these intersect with the presentation of public selves in university settings. This exploration is consistent with development of the themes of intersectionality and multiplicity in the work of Rivera and Ward in their Spring, 2008 Social Equity and Diversity symposium (2008). We as authors were initially unsure whether the effort to analyze concerns surrounding multiple identities in a PWI was an act of empowerment, or a strategic response to a work setting where some refused to recognize us as we defined ourselves. Building on this framing question and a review of pertinent literature, we set out to explore how the institutional context shapes our identities as faculty of color. Ultimately, we argue that, in addition to creating inclusive strategies for faculty of color at this level, in order to empower them the PWI must also engage in a critique of the culture of power that still prevails in higher-education institutions

Whither Maine’s Population

Demographic changes affect many aspects of a state’s economic and community well-being. Mageean, AvRuskin and Sherwood describe some of the potential impacts of Maine’s changing population. They note that the state’s population is aging; the percentage of Maine’s youth is declining faster than in other New England states; and that rates of growth remain relatively slow throughout most counties. The authors describe each of these trends, and discuss the implications for Maine’s labor force, education and health care systems. They also note that these trends will not be experienced similarly by all parts of the state. While some counties may be faced with school closures, others should begin planning now for school expansions. Similarly, in order to take care of the state’s growing elderly population, rural, poorer areas may need to adopt different strategies from urban, more prosperous areas. The authors caution readers to interpret their population predictions carefully. While predictions on births and deaths are reasonably stable, migration trends are notoriously sensitive to economic conditions. Hence, much depends on the economic health of Maine and the region in the years to come

Cooled optical filters for Q-band infrared astronomy (15-40 μm)

With a growing interest in mid- and far-infrared astronomy using cooled imaging and spectrometer instruments in high-altitude observatories and spaceflight telescopes, it is becoming increasingly important to characterise and assess the spectral performance of cooled multilayer filters across the Q-band atmospheric window. This region contains spectral features emitted by many astrophysical phenomena and objects fundamental to circumstellar and planetary formation theories. However extending interference filtering to isolate radiation at progressively longer wavelengths and improve photometric accuracy is an area of ongoing and challenging thin-film research. We have successfully fabricated cooled bandpass and edge filters with high durability for operation across the 15-30 µm Q-band region. In this paper we describe the rationale for selection of optical materials and properties of fabricated thin-film coatings for this region, together with FTIR spectral measurements and assessment of environmental durability