240 research outputs found

    Emulation of TPM on Raspberry Pi

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    The Trusted Platform Module (TPM) is a dedicated microprocessor designed to secure hardware by integrating cryptographic keys into the non-volatile memory of the module. TPM is specified by the Trusted Computing Group (TCG). TCG is an initiative started in 2003 by several multinational semiconductor and IT-companies. The initiative is an effort to develop standards for Trusted Computing where hardware is used to provide security support to software. The TPM is typically connected to the LPC bus on the motherboard of a PC and can be used to create and store cryptographic keys, generate random numbers, hash values and encrypt data. The purpose of this thesis is to develop a TPM learning environment and a laboratory manual for introductory courses in computer security where the students are able to learn about the functionalities of the TPM as a means to secure hardware. The functions of the TPM will be emulated on the ARM based single board computer Raspberry Pi developed by the Raspberry Pi foundation. The TPM commands will be executed from a PC which will connect to the Raspberry Pi remotely through TCP. Several exercises related to TPM and its functionalities are provided as an appendix to this report. The exercises are intended for students or others interested in Trusted Computing. This report also provides exercises related to the creation of TPM applications using TSS (Trusted Computing Software Stack)

    Small-scale biochar production on Swedish farms

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    Several small-scale pyrolysis plants have been installed on Swedish farms and the trend is also expanding in the Nordic countries. These projects are driven by ambitions of achieving carbon dioxide removal, reducing environmental impacts and improving farmers’ economy and resilience. The pyrolysis plants are fuelled with either commercial pellets or agricultural residues. The pyrolysis plants co-produce heat for the farm’s buildings, biochar for non-oxidative applications, mostly agricultural ones, and electricity in some cases. In the Nordic context, on-farm biochar production potential is thus linked to energy consumption. The main research question investigated is whether farms producing biochar can meet their own biochar needs in an energy-efficient way. The research also provides insights on how biochar production at various scales, centralized and decentralized, can be integrated in a given landscape. Please click Additional Files below to see the full abstract

    Assessing the diverse environmental effects of biochar systems: An evaluation framework

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    Biochar has been recognised as a carbon dioxide removal (CDR) technology. Unlike other CDR technologies, biochar is expected to deliver various valuable effects in e.g. agriculture, animal husbandry, industrial processes, remediation activities and waste management. The diversity of biochar side effects to CDR makes the systematic environmental assessment of biochar projects challenging, and to date, there is no common framework for evaluating them. Our aim is to bridge the methodology gap for evaluating biochar systems from a life-cycle perspective. Using life cycle theory, actual biochar projects, and reviews of biochar research, we propose a general description of biochar systems, an overview of biochar effects, and an evaluation framework for biochar effects. The evaluation framework was applied to a case study, the Stockholm Biochar Project. In the framework, biochar effects are classified according to life cycle stage and life cycle effect type; and the biochar?s end-of-life and the reference situations are made explicit. Three types of effects are easily included in life cycle theory: changes in biosphere exchanges, technosphere inputs, and technosphere outputs. For other effects, analysing the cause-effect chain may be helpful. Several biochar effects in agroecosystems can be modelled as future productivity increases against a reference situation. In practice, the complexity of agroecosystems can be bypassed by using empirical models. Existing biochar life cycle studies are often limited to carbon footprint calculations and quantify a limited amount of biochar effects, mainly carbon sequestration, energy displacements and fertiliser-related emissions. The methodological development in this study can be of benefit to the biochar and CDR research communities, as well as decision-makers in biochar practice and policy

    Life cycle assessment of urban uses of biochar and case study in Uppsala, Sweden

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    Biochar is a material derived from biomass pyrolysis that is used in urban applications. The environmental impacts of new biochar products have however not been assessed. Here, the life cycle assessments of 5 biochar products (tree planting, green roofs, landscaping soil, charcrete, and biofilm carrier) were performed for 7 biochar supply-chains in 2 energy contexts. The biochar products were benchmarked against reference products and oxidative use of biochar for steel production. Biochar demand was then estimated, using dynamic material flow analysis, for a new city district in Uppsala, Sweden. In a decarbonised energy system and with high biochar stability, all biochar products showed better climate performance than the reference products, and most applications outperformed biomass use for decarbonising steel production. The climate benefits of using biochar ranged from - 1.4 to - 0.11 tonne CO2-eq tonne(-1) biochar in a decarbonised energy system. In other environmental impact categories, biochar products had either higher or lower impacts than the reference products, depending on biochar supply chain and material substituted, with trade-offs between sectors and impact categories. However, several use-phase effects of biochar were not included in the assessment due to knowledge limitations. In Uppsala's new district, estimated biochar demand was around 1700 m(3) year(-1) during the 25 years of construction. By 2100, 23% of this biochar accumulated in landfill, raising questions about end-of-life management of biochar-containing products. Overall, in a post-fossil economy, biochar can be a carbon dioxide removal technology with benefits, but biochar applications must be designed to maximise co-benefits

    A spatial framework for prioritizing biochar application to arable land: A case study for Sweden

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    The biochar-agriculture nexus can potentially generate several benefits ranging from soil carbon sequestration to the reduction in nutrient leaching from arable soils. However, leveraging these benefits requires spatially-explicit information on suitable locations for biochar application. This study provides a flexible multicriteria framework that delivers spatial indications on biochar prioritization through a biochar use indication map (BUIM). The framework was exemplified as a case study for Swedish arable land through three different prioritization narratives. The BUIM for all the narratives revealed that a significant fraction of the Swedish arable land could potentially benefit from biochar application. Furthermore, arable land that scored high for a given narrative did not necessarily score high in the others, thus indicating that biochar application schemes can be adjusted to various objectives and local needs. The framework presented here aims to promote the exploration of different avenues for deploying biochar in the agricultural sector

    A spatial framework for prioritizing biochar application to arable land: A case study for Sweden

    Get PDF
    The biochar-agriculture nexus can potentially generate several benefits ranging from soil carbon sequestration to the reduction in nutrient leaching from arable soils. However, leveraging these benefits requires spatially-explicit information on suitable locations for biochar application. This study provides a flexible multicriteria framework that delivers spatial indications on biochar prioritization through a biochar use indication map (BUIM). The framework was exemplified as a case study for Swedish arable land through three different prioritization narratives. The BUIM for all the narratives revealed that a significant fraction of the Swedish arable land could potentially benefit from biochar application. Furthermore, arable land that scored high for a given narrative did not necessarily score high in the others, thus indicating that biochar application schemes can be adjusted to various objectives and local needs. The framework presented here aims to promote the exploration of different avenues for deploying biochar in the agricultural sector

    Morphological characterization of intra-articular HMGB1 expression during the course of collagen-induced arthritis

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    High-mobility group chromosomal box protein 1 (HMGB1) is a structural nuclear protein that promotes inflammation when present extracellularly. Aberrant, extracellular HMGB1 expression has been demonstrated in human and experimental synovitis. The aim of the present study was to elucidate the temporal and spatial expression of HMGB1 compared to that of the central mediators tumor necrosis factor (TNF) and interleukin-1-beta (IL-1β) during the course of collagen-induced arthritis. Thus, Dark Agouti rats were immunized with homologous type II collagen and synovial tissue specimens were obtained at various time points prior to and during the course of clinical arthritis. Local cytokine responses were assessed by immunohistochemistry and by in situ hybridization. We demonstrate a distinct nuclear expression of HMGB1 at early disease-preceding time points. Preceding clinical onset by a few days, cytoplasmic HMGB1 expression was evident in synoviocytes within the non-proliferative lining layer. Pronounced cytoplasmic and additional extracellular HMGB1 expression coincided with the progression of clinical disease. In advanced arthritis, the number of cells with cytoplasmic HMGB1 expression was quantitatively comparable to that of cells expressing TNF and IL-1β. Interestingly, although HMGB1 was abundantly expressed throughout the inflamed synovium at a protein level, upregulation of HMGB1 mRNA was restricted mainly to areas of cartilage and bone destruction. In conclusion, these new findings implicate a role for HMGB1 in both inducing and perpetuating inflammatory events of significant importance in the destructive processes in chronic arthritis

    Structural diversity in the type IV pili of multidrug-resistant Acinetobacter

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    Acinetobacter baumannii is a Gram-negative coccobacillus found primarily in hospital settings that has recently emerged as a source of hospital-acquired infections. A. baumannii expresses a variety of virulence factors, including type IV pili, bacterial extracellular appendages often essential for attachment to host cells. Here, we report the high resolution structures of the major pilin subunit, PilA, from three Acinetobacter strains, demonstrating thatA. baumannii subsets produce morphologically distinct type IV pilin glycoproteins. We examine the consequences of this heterogeneity for protein folding and assembly as well as host-cell adhesion by Acinetobacter. Comparisons of genomic and structural data with pilin proteins from other species of soil gammaproteobacteria suggest that these structural differences stem from evolutionary pressure that has resulted in three distinct classes of type IVa pilins, each found in multiple species
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