| 1. |
- Busse, Christian, 1989-
(författare)
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Aspects of Crack Growth in Single-Crystal Nickel-Base Superalloys
- 2017
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This Licentiate of Engineering thesis is a product of the results generated in the research project KME-702, which comprises modelling, microstructure investigations and material testing of cast nickel-base superalloys.The main objective of this work is to model the fatigue crack propagation behaviour in single-crystal nickel-base superalloys. To achieve this, the influence of the crystal orientations on the cracking behaviour is assessed. The results show that the crystal orientation is strongly affecting the material response and must be accounted for. Furthermore, a linear elastic crack driving force parameter suitable for describing crystallographic cracking has been developed. This parameter is based on resolved anisotropic stress intensity factors and is able to predict the correct crystallographic cracking plane after a transition from a Mode I crack. Finally, a method to account for inelastic deformations in a linear elastic fracture mechanics context was investigated. A residual stress field is extracted from an uncracked finite-element model with a perfectly plastic material model and superimposed on the stress field from the cracked model with a linear elastic material model to account for the inelastic deformations during the determination of the crack driving force. The modelling work is validated by material testing on two different specimen geometries at different temperatures.This Licentiate of Engineering thesis consists of two parts, where Part I gives an introduction and background to the research area, while Part II consists of three papers.
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| 2. |
- Busse Nielsen, Anders, et al.
(författare)
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Municipal woodland in Denmark: resources, governance and management
- 2013
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Ingår i: Scandinavian Journal of Forest Research. - : Informa UK Limited. - 0282-7581 .- 1651-1891. ; 28, s. 49-63
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Tidskriftsartikel (refereegranskat)abstract
- Urban woodlands are the subject of complex decision-making that requires a strategic overview of the resource. This article contributes a national study of municipal woodland in Denmark. Data were collected among all Danish municipalities through a postal survey (with a response rate of 52%). As much as 83% of the woodland units were located within urban settlements or at their fringe, emphasising that municipalities are important urban woodland providers. Municipal woodland resources were typically divided into many separate units of varying size. On average, the responding municipalities owned 12.6 woodland units with an allocated area of 265 ha, resulting in a mean size of 21.5 ha. A general lack of management plans, and a significant drop in recreational facilities provided with decreasing woodland size indicate that the recreational use potential of small woodland units was largely overlooked. Municipal woodland units frequently bordered other woodland or nature areas of different ownership. Thus even small municipal woodlands can play a key role in the development of multifunctional green infrastructures in the urban landscape. Only municipalities with extensive woodland property had issued a woodland policy, and/or certified woodland management. This indicates a need for development of governance and strategic management instruments attractive to municipalities with limited woodland property.
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| 3. |
- Busse Nielsen, Anders, et al.
(författare)
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Spatial configurations of urban forest in different landscape and socio-political contexts: identifying patterns for green infrastructure planning
- 2017
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Ingår i: Urban Ecosystems. - : Springer Science and Business Media LLC. - 1083-8155 .- 1573-1642. ; 20, s. 379-392
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Tidskriftsartikel (refereegranskat)abstract
- Abstract Rapid urbanisation and climate change have motivated the development of urban green infrastructure (UGI) as a planning strategy to support the wellbeing of urban people and ecosystems while parallel adapting cities to climate change. Forest (tree-covered areas >0.5 ha) is a key UGI component that afford a wider range of ecosystem services and mitigate urban heat islands more effectively than non-wooded green spaces. However, understanding of spatial configurations (variation in patch size and frequency) of forests across the gradient of urbanisation and between cities is limited to case studies. This represents a considerable knowledge gap for identification of general patterns that can inform integration of forest resources in UGI planning that have value beyond the individual city level. In this study we used Geographic Information Systems to explore the spatial configuration of forests across cities located within landscapes characterised by different levels of anthropogenic modification (degree of forest cover) and socio-political contexts, i.e. all Danish and Swedish cities >10,000 inhabitants (n = 176). We applied general linear modelling to investigate the relationship between forest cover, patch size and frequency with 1) regional landscape type, 2) demographic trends 1960-2010, and 3) the gradient of urbanisation (measured in three zones: urban core (0.2 km from city boundary), urban fringe (0.2-2 km), and urban periphery (2-5 km)). Regardless of demographic trends, forest cover was lowest in cities settled in large-scale agricultural regions, higher in regions with mosaics of forest and farming, and highest in forest-dominated regions. However, in all cities forest cover was lowest in the urban zone and peaked on the urban fringe rather than on the urban periphery. Furthermore, pocket woods (0.5-2 ha) accounted for over 50 % of patches in all three urban zones, irrespective of regional landscape type. We conclude by discussing how these general patterns could inform strategies for integration of urban forests in UGI planning.
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| 4. |
- Foessl, Ines, et al.
(författare)
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Bone Phenotyping Approaches in Human, Mice and Zebrafish – Expert Overview of the EU Cost Action GEMSTONE (“GEnomics of MusculoSkeletal traits TranslatiOnal NEtwork”)
- 2021
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Ingår i: Frontiers in Endocrinology. - : Frontiers Media SA. - 1664-2392. ; 12
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Forskningsöversikt (refereegranskat)abstract
- A synoptic overview of scientific methods applied in bone and associated research fields across species has yet to be published. Experts from the EU Cost Action GEMSTONE (“GEnomics of MusculoSkeletal Traits translational Network”) Working Group 2 present an overview of the routine techniques as well as clinical and research approaches employed to characterize bone phenotypes in humans and selected animal models (mice and zebrafish) of health and disease. The goal is consolidation of knowledge and a map for future research. This expert paper provides a comprehensive overview of state-of-the-art technologies to investigate bone properties in humans and animals – including their strengths and weaknesses. New research methodologies are outlined and future strategies are discussed to combine phenotypic with rapidly developing –omics data in order to advance musculoskeletal research and move towards “personalised medicine”.
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| 5. |
- Jovanovic, Milena, et al.
(författare)
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Perturbed bone composition and integrity with disorganized osteoblast function in zinc receptor/Gpr39-deficient mice
- 2018
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Ingår i: FASEB Journal. - 0892-6638. ; 32:5, s. 2507-2518
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Tidskriftsartikel (refereegranskat)abstract
- Changes in bone matrix composition are frequently found with bone diseases and may be associated with increased fracture risk. Bone is rich in the trace element zinc. Zinc was established to play a significant role in the growth, development, and maintenance of healthy bones; however, the mechanisms underlying zinc effects on the integrity of the skeleton are poorly understood. Here, we show that the zinc receptor (ZnR)/Gpr39 is required for normal bone matrix deposition by osteoblasts. Initial analysis showed that Gpr39-deficient (Gpr39-/-) mice had weaker bones as a result of altered bone composition. Fourier transform infrared spectroscopy analysis showed high mineral-to-matrix ratios in the bones of Gpr39-/- mice. Histologic analysis showed abnormally high numbers of active osteoblasts but normal osteoclast numbers on the surfaces of bones from Gpr39-/- mice. Furthermore, Gpr39-/- osteoblasts had disorganized matrix deposition in vitro with cultures exhibiting abnormally low collagen and high mineral contents, findings that demonstrateacell-intrinsic role for ZnR/Gpr39 in these cells. We show that both collagen synthesis and deposition by Gpr39-/- osteoblasts are perturbed. Finally, the expression of the zinc transporter Zip13 and a disintegrin and metalloproteinase with thrombospondin motifs family of zinc-dependent metalloproteases that regulate collagen processing was downregulated in Gpr39-/- osteoblasts. Altogether, our results suggest that zinc sensing by ZnR/Gpr39 affects the expression levels of zinc-dependent enzymes in osteo-blasts and regulates collagen processing and deposition.
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| 6. |
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| 7. |
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| 8. |
- Richnau, Gustav, et al.
(författare)
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Planting clonal shade-tolerant herbs in young urban woodlands-Effects of compost on plant growth, flowering and survival
- 2016
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Ingår i: Urban Forestry & Urban Greening. - : Elsevier BV. - 1618-8667 .- 1610-8167. ; 17, s. 158-165
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Tidskriftsartikel (refereegranskat)abstract
- Rich herbaceous layers supply important ecosystem functions and amenity values in urban woodlands. However, due to poor dispersal and recruitment, typical woodland herbs often remain absent in woodlands established on post-agricultural and post-industrial sites, especially in fragmented urban landscapes. Efficient methods for active restoration of the herbaceous layer are therefore needed. In a plantation experiment in an 11-year-old oak stand established on post-agricultural land just outside Malmo City, southern Sweden, this study investigated the effects of compost addition and weed control on post-planting survival, growth and flowering of three typical shade-tolerant woodland herb species: Galium odoratum, Lamiastrum galeobdolon and Stellaria holostea. Removal of competing weed vegetation did not affect plant performance, but compost addition dramatically increased growth and flowering of all three species during the first two growing seasons, and also increased survival in S. holostea. This positive treatment effect probably derived from a more suitable top soil structure and a higher soil moisture in the compost treatment. We conclude that combined use of planting and composting is an effective method for rapid achievement of profusely flowering carpets of summer-green woodland herbs, which can provide important amenity values in the many woodlands established in and around cities in north-west Europe in recent decades. The method may also be applicable in other woodland restoration projects, where it can promote colonisation by typical shade-tolerant woodland herb species. (C) 2016 Elsevier GmbH. All rights reserved.
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| 9. |
- Wiström, Björn, et al.
(författare)
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BATAG – en skötselmodell för skogsbryn i infrastrukturmiljöer
- 2015
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Utvidgade skötselgator som skapas vid trädsäkring av järnvägar kan röjas selektivt för att utveckla trädsäkra skogsbryn som även kan bidra till naturvården och landskapsbilden. För detta krävs robusta skötselmodeller för skogsbryn anpassade till infrastrukturmiljöer. Baserat på inventering och analys av 78 lokaler stratifierat slumpade längs med hela södra stambanan mellan Malmö och Stockholm, redovisar denna rapport en överblick över artsammansättningen och dess grupperingar längs sträckan. Utifrån detta konceptualiseras och diskuteras BATAG (Röjning av endast Björk, Asp, Tall, Al och Gran) som en skötselmodell för skogsbryn i infrastrukturmiljöer, som inte kräver en stor artkunskap av utföraren men samtidigt gynnar en stor mängd av olika småträd och buskar.
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| 10. |
- Wiström, Björn, et al.
(författare)
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Decisive environmental characteristics for woody regrowth in forest edges - Patterns along complex environmental gradients in Southern Sweden
- 2016
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Ingår i: Forest Ecology and Management. - : Elsevier BV. - 0378-1127 .- 1872-7042. ; 363, s. 47-62
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Tidskriftsartikel (refereegranskat)abstract
- Early and late successional stages of forest edge development were studied across long, complex environmental gradients in order to disentangle and assess the woody species composition and functional traits' relations to abiotic and biotic environmental characteristics at site and landscape scale. Data were sampled from 78 randomly stratified locations along a 610-km railway corridor between the cities of Stockholm and Malmo, Sweden, and subsequently analysed in multiple steps of unconstrained, constrained and partial constrained ordination and variation partitioning. Different analytical methods were applied at each step and only the environmental characteristics that repeatedly showed significant impacts on woody species composition were selected for analysis of average weighted community traits to provide verification and a more detailed understanding. Following this approach, 10 environmental characteristics were identified as decisive for the woody species composition of the forest edges. The variation partitioning revealed a marked shift in the relative explanatory power of the environmental variables in relation to the succession of the forest edges. In the early successional stage, the abiotic variables related to site productivity (as reflected by field layer type and soil moisture) and climate (humidity and altitude) dominate, while in the late successional stages of forest edges more complex patterns evolved due to hierarchical and dynamic filter effects, where biotic variables reflecting structural aspects at site (forest edge profile, canopy stratification and canopy cover) and landscape (forest continuity and the shape and contrast of edges in the surrounding landscape) level were equally important as the abiotic variables. We concluded that management efforts in early succession stages of forest edges should depart from basic abiotic gradients of site fertility and moisture; and that it is crucial to incorporate vegetation structure variables at site and landscape level into long-term management planning. (C) 2015 Elsevier B.V. All rights reserved.
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