Effect of repeated mowing to reduce graminoid plant cover on the moss carpet at a Sphagnum farm in North America

Sphagnum farming is defined as the sustainable production of non-decomposed Sphagnum biomass on a cyclical and renewable basis. In this article, the influence and necessity of mowing graminoid plants to optimise Sphagnum growth in Sphagnum farming basins are examined. Repeated mowing was applied to reduce graminoid plant cover at two different stages of the production cycle (one-year-old and seven-year-old Sphagnum moss carpet at the beginning of the experiment) at an experimental Sphagnum farm in eastern Canada. Sphagnum growth (cover, biomass, moss layer thickness) was measured after three years of mowing. In addition, a greenhouse experiment was carried out to determine whether there is a threshold for graminoid plant cover beyond which mowing becomes necessary. Sphagnum cover and biomass were not affected by repeated mowing, even if mowing reduced the cover of graminoid plants. Thus, it appears that mowing is unnecessary if the dominant vascular species is a graminoid plant such as Eriophorum angustifolium, which accumulates minimal amounts of litter. Furthermore, high cover of Eriophorum angustifolium (up to 85 %) did not affect Sphagnum cover in a density-controlled greenhouse experiment. When the specific goal is Sphagnum fibre production, decisions about control of graminoid plants should be made after considering the cover, life form and litter accumulation potentials of the dominant graminoid species involved

Sphagnum farming from species selection to the production of growing media : a review

Sphagnum farming - the production of Sphagnum biomass on rewetted bogs - helps towards achieving global climate goals by halting greenhouse gas emissions from drained peat and by replacing peat with a renewable biomass alternative. Large-scale implementation of Sphagnum farming requires a wide range of know-how, from initial species selection up to the final production and use of Sphagnum biomass based growing media in horticulture. This article provides an overview of relevant knowledge accumulated over the last 15 years and identifies open questions.Peer reviewe

Mesh Simplification for Unfolding*

We present a computational approach for unfolding 3D shapes isometrically into the plane as a single patch without overlapping triangles. This is a hard, sometimes impossible, problem, which existing methods are forced to soften by allowing for map distortions or multiple patches. Instead, we propose a geometric relaxation of the problem: We modify the input shape until it admits an overlap‐free unfolding. We achieve this by locally displacing vertices and collapsing edges, guided by the unfolding process. We validate our algorithm quantitatively and qualitatively on a large dataset of complex shapes and show its proficiency by fabricating real shapes from paper.Computer Graphics ForumOriginal Article44

Mesh Simplification for Unfolding

International audienceAbstract We present a computational approach for unfolding 3D shapes isometrically into the plane as a single patch without overlapping triangles. This is a hard, sometimes impossible, problem, which existing methods are forced to soften by allowing for map distortions or multiple patches. Instead, we propose a geometric relaxation of the problem: We modify the input shape until it admits an overlap‐free unfolding. We achieve this by locally displacing vertices and collapsing edges, guided by the unfolding process. We validate our algorithm quantitatively and qualitatively on a large dataset of complex shapes and show its proficiency by fabricating real shapes from paper

Atomiseur : au-delà du tranchage non planaire pour la fabrication par dépôt de fil fondu

Proceedings of the Symposium on Geometry ProcessingInternational audienceAbstract Fused filament fabrication (FFF) enables users to quickly design and fabricate parts with unprecedented geometric complexity, fine‐tuning both the structural and aesthetic properties of each object. Nevertheless, the full potential of this technology has yet to be realized, as current slicing methods fail to fully exploit the deposition freedom offered by modern 3D printers. In this work, we introduce a novel approach to toolpath generation that moves beyond the traditional layer‐based concept. We use frames, referred to as atoms , as solid elements instead of slices. We optimize the distribution of atoms within the part volume to ensure even spacing and smooth orientation while accurately capturing the part's geometry. Although these atoms collectively represent the complete object, they do not inherently define a fabrication plan. To address this, we compute an extrusion toolpath as an ordered sequence of atoms that, when followed, provides a collision‐free fabrication strategy. This general approach is robust, requires minimal user intervention compared to existing techniques, and integrates many of the best features into a unified framework: precise deposition conforming to non‐planar surfaces, effective filling of narrow features – down to a single path – and the capability to locally print vertical structures before transitioning elsewhere. Additionally, it enables entirely new capabilities, such as anisotropic appearance fabrication on curved surfaces.La fabrication par dépôt de filament fondu (FFF) permet aux utilisateurs de concevoir et de fabriquer rapidement des pièces présentant une complexité géométrique inédite, tout en ajustant finement les propriétés structurelles et esthétiques de chaque objet. Néanmoins, le plein potentiel de cette technologie reste encore à exploiter, car les méthodes de tranchage actuelles n’utilisent pas pleinement la liberté de dépôt qu’offrent les imprimantes 3D modernes.Dans ce travail, nous introduisons une nouvelle approche de génération de trajectoires d’outils qui dépasse le concept traditionnel basé sur les couches. Nous utilisons des atomes, comme éléments solides plutôt que des tranches. Nous optimisons la distribution des atomes dans le volume de la pièce afin de garantir un espacement régulier et une orientation fluide, tout en capturant fidèlement la géométrie de l’objet. Bien que ces atomes représentent collectivement l’objet complet, ils ne définissent pas en eux-mêmes un plan de fabrication. Pour y remédier, nous calculons une trajectoire d’extrusion sous forme d’une séquence ordonnée d’atomes qui, une fois suivie, fournit une stratégie de fabrication sans collisions.Cette approche générale est robuste, nécessite une intervention minimale de l’utilisateur par rapport aux techniques existantes, et intègre de nombreuses fonctionnalités de pointe dans un cadre unifié : dépôt précis épousant des surfaces non planes, remplissage efficace de caractéristiques étroites — jusqu’à une seule trajectoire —, et possibilité d’imprimer localement des structures verticales avant de passer ailleurs. De plus, elle ouvre la voie à de nouvelles capacités, telles que la fabrication d’apparences anisotropes sur des surfaces courbes

Sphagnum farming from species selection to the production of growing media: a review

Sphagnum farming - the production of Sphagnum biomass on rewetted bogs - helps towards achieving global climate goals by halting greenhouse gas emissions from drained peat and by replacing peat with a renewable biomass alternative. Large-scale implementation of Sphagnum farming requires a wide range of know-how, from initial species selection up to the final production and use of Sphagnum biomass based growing media in horticulture. This article provides an overview of relevant knowledge accumulated over the last 15 years and identifies open question