Model-based Inversion for Flash Thermography

The thermal image sequences from thermography experiments are blurred by lateral diffusion and therefore hard to interpret. The widely used one-dimensional heat flow model provides a robust interpretation of thickness or delamination from “break time” where lateral diffusion is significant, but is less effective otherwise. As a result, it remains quite common to interpret defects by contrast from the surrounding “acreage” rather than by the intrinsic properties of the defect signal itself. In this paper, we present an approach for model-based inversion of flash thermography image sequences that attempts to approximately reconstruct the flow or back-surface geometry from the thermal image sequence. The reconstruction is based on representing reflectors as buried heatsources and interpretingthe spatial and temporal heat distribution on the surface as a linear combination of the Green’s functions of those sources through linear inversion. The result is a spatial map of reflector intensity at a series of layers. Resolution decreases with depth, representing the inherent blurring due to thermal diffusion. The reconstruction is not perfect; the representation of lateral diffusion is approximate and the reconstruction causes substantial noise gain. Defects behind or nearly behind other defects may not be represented correctly. But the reconstruction does provide a physical interpretation that includes lateral heat flows observed in a flash thermography experiment

Registration of ‘Rasmusson’ barley

‘Rasmusson’ (Reg. No. CV-345, PI 658495) is a spring, six-rowed, malting barley (Hordeum vulgare L.) released by the Minnesota Agricultural Experiment Station in January 2008. It was named after Donald Rasmusson, who worked as a barley breeder at the University of Minnesota from 1958 to 2000. Rasmusson has the pedigree M95/‘Lacey’ and is the product of advanced cycle breeding derived from crosses among elite breeding lines within the University of Minnesota breeding program. Rasmusson was released based on its superior yield performance across the Upper Midwest of the United States and surrounding regions in Canada and favorable malting quality, in particular, high malt extract. Rasmusson is resistant to spot blotch [caused by Cochliobolus sativus (Ito and Kuribayashi) Drechs. ex Dastur] and the prevalent races of stem rust (caused by Puccinia graminis Pers.: Pers. f. sp. tritici Erikss. & E. Henn)

Registration of ‘Quest’ spring malting barley with improved resistance to Fusarium head blight

‘Quest’ (Reg No. CV-348, PI 663183) is a spring, six-rowed, malting barley (Hordeum vulgare L.) released by the Minnesota Agricultural Experiment Station in January 2010 on the basis of its improved resistance to Fusarium head blight [FHB; caused by Fusarium graminearum Schwabe; teleomorph Gibberella zeae (Schwein) Petch]. Quest was developed over three breeding cycles of selection for yield, malting quality, and FHB resistance. Disease resistance traces to the Midwest cultivar MNBrite and the two-rowed accession from China Zhedar1. Quest has about half the level of disease and about 40% less of the associated mycotoxin, deoxynivalenol, compared to the historically important cultivar in the region ‘Robust’. Quest is similar in yield to the current dominant varieties in the region and was approved as a malting variety by the American Malting Barley Association

Model-based Inversion for Flash Thermography

The thermal image sequences from thermography experiments are blurred by lateral diffusion and therefore hard to interpret. The widely used one-dimensional heat flow model provides a robust interpretation of thickness or delamination from “break time” where lateral diffusion is significant, but is less effective otherwise. As a result, it remains quite common to interpret defects by contrast from the surrounding “acreage” rather than by the intrinsic properties of the defect signal itself. In this paper, we present an approach for model-based inversion of flash thermography image sequences that attempts to approximately reconstruct the flow or back-surface geometry from the thermal image sequence. The reconstruction is based on representing reflectors as buried heatsources and interpretingthe spatial and temporal heat distribution on the surface as a linear combination of the Green’s functions of those sources through linear inversion. The result is a spatial map of reflector intensity at a series of layers. Resolution decreases with depth, representing the inherent blurring due to thermal diffusion. The reconstruction is not perfect; the representation of lateral diffusion is approximate and the reconstruction causes substantial noise gain. Defects behind or nearly behind other defects may not be represented correctly. But the reconstruction does provide a physical interpretation that includes lateral heat flows observed in a flash thermography experiment.</p