Demonstration test of burner liner strain measurements using resistance strain gages

A demonstration test of burner liner strain measurements using resistance strain gages as well as a feasibility test of an optical speckle technique for strain measurement are presented. The strain gage results are reported. Ten Kanthal A-1 wire strain gages were used for low cycle fatigue strain measurements to 950 K and .002 apparent strain on a JT12D burner can in a high pressure (10 atmospheres) burner test. The procedure for use of the strain gages involved extensive precalibration and postcalibration to correct for cooling rate dependence, drift, and temperature effects. Results were repeatable within + or - .0002 to .0006 strain, with best results during fast decels from 950 K. The results agreed with analytical prediction based on an axisymmetric burner model, and results indicated a non-uniform circumferential distribution of axial strain, suggesting temperature streaking

High temperature strain gage technology for hypersonic aircraft development applications

An experimental evaluation of Pd 13 percent Cr and of BCL-3 alloy wire strain gages was conducted on IN100 and Cu 0.15 percent Zr alloy substrates. Testing included apparent strain, drift, gage factor, and creep. Maximum test temperature was 1144 K (1600 F). The PdCr gages incorporated Pt temperature compensation elements. The PdCr gages were found to have good resistance stability below 866 K (1100 F). The BCL 3 gages were found to have good resistance stability above 800 K (981 F), but high drift around 700 K (800 F)

THE NEW WAVE OF REGIONALISM: DOES OUTSIDER/INSIDER STATUS AFFECT THE COMPETITIVENESS OF U.S. AGRICULTURAL EXPORTS?

The degree to which countries are pursuing regional trade agreements (RTAs) has been nothing short of extraordinary. The topic of regional integration is “breeding concern” among academics and policymakers as to the intra- and extra-regional effects of these agreements. This study constructs and uses an updated database of agricultural trade flows from 1992-2008 to shed light on the degree to which insider and outsiders status affects U.S. agricultural exporters and its competing suppliers. Regarding outsider status, we modify the existing approach by incorporating region-specific extra-bloc trade flow variables to examine the degree to which RTAs divert trade from specific regions of the world. The results are quite illuminating. While RTAs may not be trade diverting on net, all RTAs considered exhibit trade diversion with respect to at least some regions. The results have important policy implications for nations that are not actively participating in the latest wave of regionalism.International Relations/Trade,

Studies of satellite support to weather modification in the western US region

The applications of meteorological satellite data to both summer and winter weather modification programs are addressed. Appraisals of the capability of satellites to assess seedability, to provide real-time operational support, and to assist in the post-experiment analysis of a seeding experiment led to the incorporation of satellite observing systems as a major component in the Bureau of Reclamations weather modification activities. Satellite observations are an integral part of the South Park Area cumulus experiment (SPACE) which aims to formulate a quantitative hypothesis for enhancing precipitation from orographically induced summertime mesoscale convective systems (orogenic mesoscale systems). Progress is reported in using satellite observations to assist in classifying the important mesoscale systems, and in defining their frequency and coverage, and potential area of effect. Satellite studies of severe storms are also covered

Sparse approximation of multivariate functions from small datasets via weighted orthogonal matching pursuit

We show the potential of greedy recovery strategies for the sparse approximation of multivariate functions from a small dataset of pointwise evaluations by considering an extension of the orthogonal matching pursuit to the setting of weighted sparsity. The proposed recovery strategy is based on a formal derivation of the greedy index selection rule. Numerical experiments show that the proposed weighted orthogonal matching pursuit algorithm is able to reach accuracy levels similar to those of weighted $\ell^1$ minimization programs while considerably improving the computational efficiency for small values of the sparsity level

Ross’s Gull (Rhodostethia rosea) Breeding in Penny Strait, Nunavut, Canada

We found a small, previously undiscovered breeding colony of Ross’s gulls (Rhodostethia rosea) in Nunavut, Canada, approximately 80 km from a previous colony location occupied during the 1970s. The birds nested in association with arctic terns (Sterna paradisaea). The collective observations from this region of the High Arctic suggest that Ross’s gulls may move colonies each year, or that colony occupation is intermittent.Nous avons repéré une petite colonie de reproduction de mouettes rosées (Rhodostethia rosea) non découverte jusqu’à ce moment-là au Nunavut, au Canada, à environ 80 kilomètres de l’emplacement d’une autre colonie occupée dans les années 1970. Les oiseaux nichaient avec des sternes arctiques (Sterna paradisaea). Les observations collectives de cette région de l’Extrême-Arctique laissent supposer que les mouettes rosées peuvent changer de colonie chaque année ou que l’occupation des colonies est intermittente