G-code Modeling for 3D Printer Quality Assessment

The Department of Computer Science at the University of North Dakota (UND) has been evaluating optical/imaging methods for measuring the quality of 3D printed parts. In particular, we are interested in optical/imaging methods that can detect and measure such quality issues as layer shifting, layer separation and splitting, overheating, dimensional accuracy, and infill errors. This paper describes our work towards the analysis of infill errors as the quality of the infill does impact the structural integrity of the part being made. Externally, a part may look acceptable, but if the infill is faulty the part may be structurally unsound. Furthermore, once a part is finished printing it is usually not possible to see the infill. Therefore, monitoring of the infill must be done while the part is being printed

Wild-boar disturbance increases nutrient and C stores of geophytes in subalpine grasslands

Premise of the study: Wild-boar soil disturbance (i.e., rooting) increases the abundance of some species of geophytes (i.e., plants with underground renewal buds) in upland meadows. However, the mechanisms that could lead to such enhanced prevalence remain unexplored. Methods: We analyzed the effects of wild-boar disturbance on the size, nutrient (N, P, K, C, and total ash), and nonstructural carbohydrate (soluble sugars, starch plus fructans, and total nonstructural carbohydrate) content of the storage organs of fi ve taxa of upland geophytes. Results were explored in relation to the nutrient availability (total N, available P, and K) in the soil. Key results: Wild-boar rooting increased the size and the nutrient content of the storage organs of geophytes. Such enhanced storage was further promoted by rooting recurrence and intensity. Although we could not detect a direct impact of rooting on soil nutrient concentrations, plants were clearly N limited and such limitation was ameliorated in areas rooted by wild boar. Furthermore, plant-soil interactions for N were different in rooted areas, where plant N-concentrations responded positively to soil N. Conclusions: Geophytes growing in rooted areas have an increased nutrient value, which may promote the revisit of wild boars to previously rooted areas, with further positive feed-back effects on plant quality. This plant-animal interaction may shape upland geophyte communities. © 2013 Botanical Society of America.The authors thank A. Donellan, T. Bork, and J. Tapia for help with fi eld work and sample processing, as well as P. Kotanen and two anonymous reviewers for providing useful comments to earlier versions of the manuscript. Research was funded by projects CGL2011-26654, CGL 2010- 21642 and CGL2010-16880 from the Ministerio de Ciencia e Innovación and the project ARBALMONT (786-2012) from the Organismo Autónomo de Parques Nacionales. The fi rst author was funded by a Juan de la Cierva Contract from the MCI (Spain). C.G.B. is benefi ciary of a postdoctoral grant from the AXA Research Fund and an Honorary Izaak Walton Killam fellowship from the University of Alberta.Peer Reviewe