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3. |
- Hagberg, Cecilia, et al.
(author)
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Lättviktsgrindar av höghållfast stål för säkrare djurhantering och arbetsmiljö
- 2021
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Reports (other academic/artistic)abstract
- Lightweight gates of high-strength steel for improved worker safety and cattle handling This report presents the work with developing a lightweight gate of high-strength steel for the handling of cattle. The project was conducted as a European Innovation Partnership (EIP) project. The project group consisted of co-workers from the unit of Agriculture and Horticulture and the unit of Process and Environmental Engineering at Research Institutes of Sweden (RISE Jordbruk och trädgård och RISE Kretsloppsteknik), Parsteel AB (former Nilssons Plåtindustri AB), SSAB EMEA AB, Sophie Atkinson at Smart Animal Handling, Swedish University of Agricultural Sciences (SLU) in Skara and the cattle farmer Lars Olsson. The main objectives of the project were to develop a lightweight gate weighing at least 50% less and being three times as strong as a traditional gate for cattle handling. The main motive was to improve the ergonomic conditions and working environment for the animal handlers. Additionally, for the safety of both animals and handlers, the gate must withstand the loads from cattle. Other objectives were to design and construct a gate that does not exceed the price of a high-quality gate and not contribute to increased negative environmental impact. A lightweight gate can be made of various materials such as plastic, fiberglass or steel. Regarding the project group's participants and their competencies, in addition to the numerous requirements placed on a lightweight gate, the choice fell on high-strength steel. High-strength steel is characterized by having high yield strengths, up to 1300 MPa, in comparison with traditional construction steel with yield strength of 355 MPa. For the specific lightweight gate, steel pipes with a yield strength of approximately 750 MPa were chosen. These pipes are mainly used in the automotive and engine industry, where high demands are placed on strength while at the same time a light construction is desired. The gate itself was designed during the project and several details were examined and developed in regard to functionality and safety for both cattle and handlers. The work environment legislation states that gates must be dimensioned and anchored so that the animals cannot break out (AFS 2008:17). The gates must also not pose a risk of injury to the cattle. In order to work safely with cattle, knowledge of cattle behavior is essential and consequently the report contains a chapter describing cattle senses and behavior. Both the lightweight gates and the handling system, built up by the gates, must be adapted to the cattle. In the project, the bud box handling system was tested. The handling system was originally developed to make use of the behavioral characteristics of cattle to encourage forward movement in the desired direction. In the project the handling system's functionality and safety, by using lightweight gates and additional equipment and components, were further designed. The handling system was tested in two groups of heifers at the SLU Götala Beef and Lamb Research Centre. The lightweight gates were also tested in a dairy herd and a beef herd, while hoof trimming, and at a small-scale abattoir. Generally, the light weight of the gates was considered an advantage as the handling of the gates is simplified also resulting in more frequent use of the gates, increasing safety for both animals and humans. During the project, several strength tests were performed by building unique test rigs. In one test rig, the weld of the pipes of the lightweight gate was tested. In another test rig, the strength of lightweight gates, compared with traditional gates on the market, were tested. The outcome of the tests confirmed the original aim of the project, a lightweight gate made of high-strength steel, about 50% lighter and at least three times as strong as traditional gates, had been developed and designed during the project period.
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6. |
- Waldenström, Cecilia, et al.
(author)
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Bioenergy From Agriculture : Challenges for the Rural Development Program in Sweden
- 2016
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In: Society & Natural Resources. - : Routledge. - 0894-1920 .- 1521-0723. ; , s. 1-16
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Journal article (peer-reviewed)abstract
- This article addresses the challenges for the EU Rural Development Program (RDP) to promote sustainable bioenergy production from agriculture. Drawing on the Swedish example, we identify opportunities for farmers and discuss agricultural-based bioenergy production in relation to the program objectives for agricultural competitiveness, sustainability and climate effects, and rural development. The sustainability and climate effects of agricultural-based bioenergy can be ascertained only through contextual analysis, and research indicates that rural development may be best promoted through local collaborative energy systems. Contrasting two ideal-type roles farmers may assume in bioenergy production, we discuss Swedish institutional contexts of energy production. In Sweden, the national energy policy tends to favor large-scale energy solutions and farmers taking on the roles as suppliers of primary products in large-scale energy systems. For RDP objectives to be realized, this tendency needs to be countered, local solutions need to be supported, and a national three-tiered energy policy integration needs to be furthered.
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7. |
- Ahlgren, Serina, et al.
(author)
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EU sustainability criteria for biofuels : Uncertainties in GHG emissions from cultivation
- 2012
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In: Biofuels. - : Informa UK Limited. - 1759-7269 .- 1759-7277. ; 3:4, s. 399-411
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Journal article (peer-reviewed)abstract
- Background: Cultivation of raw material represents a large proportion of biofuelś GHG emissions. The EU renewable energy directive 2009/28/EC specifies a GHG emission default value for cultivation of biofuel raw material (23 g CO2-e/MJ ethanol for wheat). The aim of this study was to quantify the uncertainty in GHG emissions for wheat cultivation in Sweden, considering uncertainty and variability in data at farm level. Results: Two levels of data collection at farm level were analyzed; simple (only yield and amount of N) and advanced (also including amounts and types of energy). The 2.5-97.5 percentile uncertainty for Swedish winter wheat was 20-27 g CO 2-e/MJ, which can be considered large in the context of the Directives threshold of 23 g (to two significant figures). Conclusion: It is concluded that quantifying GHG emissions in order to regulate biofuels is a difficult task, especially emissions from cultivation, since these are biological systems with large variability.
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9. |
- Andersson, Sandra, et al.
(author)
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Insufficient antibody validation challenges oestrogen receptor beta research
- 2017
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In: Nature Communications. - : NATURE PUBLISHING GROUP. - 2041-1723. ; 8
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Journal article (peer-reviewed)abstract
- The discovery of oestrogen receptor beta (ER beta/ESR2) was a landmark discovery. Its reported expression and homology with breast cancer pharmacological target ER alpha (ESR1) raised hopes for improved endocrine therapies. After 20 years of intense research, this has not materialized. We here perform a rigorous validation of 13 anti-ER beta antibodies, using well-characterized controls and a panel of validation methods. We conclude that only one antibody, the rarely used monoclonal PPZ0506, specifically targets ER beta in immunohistochemistry. Applying this antibody for protein expression profiling in 44 normal and 21 malignant human tissues, we detect ER beta protein in testis, ovary, lymphoid cells, granulosa cell tumours, and a subset of malignant melanoma and thyroid cancers. We do not find evidence of expression in normal or cancerous human breast. This expression pattern aligns well with RNA-seq data, but contradicts a multitude of studies. Our study highlights how inadequately validated antibodies can lead an exciting field astray.
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10. |
- Azzi, Elias, et al.
(author)
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Biochar in Swedish agriculture – straw pyrolysis as a first step towards net-zero
- 2022
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Reports (other academic/artistic)abstract
- Biochar is a method for carbon dioxide removal through long-term storage of biogenic carbon in soil. Quantifying biochar impacts on agricultural greenhouse gas emissions requires a systems perspective since biochar can be produced from various agricultural feedstocks, and will have various effects when applied on cropland. In this report, climate impacts are quantified in a life cycle assessment of wheat production in Sweden using biochar produced from straw. When comparing wheat production with biochar to either ploughing straw back into soil, or using straw for heat production, the climate impact of wheat is reduced by about 45%. Some factors that have large influence on the result are the assumptions on the energy system, long-term biochar stability, and effects of biochar on crop yield. Biochar sustainability, potential and implementation are also discussed in the report. In total, the prospects for biochar as a climate solution for Swedish food and agriculture are complex but also diverse and promising.
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11. |
- Azzi, Elias, 1992-
(author)
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Biochar systems across scales in Sweden : An industrial ecology perspective
- 2021
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Doctoral thesis (other academic/artistic)abstract
- Biochar – the carbon rich residue derived from biomass pyrolysis – is recognised as a potential solution to remove carbon dioxide from the atmosphere, while simultaneously delivering socio-environmental benefits through biochar use as a material. Perceived as a sustainable innovation, biochar has raised interest throughout the world. Sweden has witnessed a rising interest for biochar over the past decade, leading to investments in modern biochar production capacity and the development of various biochar-based products. However, as for any emerging technology, it is necessary to study its environmental performance in a systematic manner to guarantee that environmental expectations meet reality, and to enable science-based policy support.This thesis examined the energy, climate and environmental impacts of biochar production and use, supporting on-going and future projects in Sweden. Four case studies were designed, set respectively in Stockholm, Nyköping, Helsingborg and Uppsala areas. The case studies analysed biochar production at various scales, from different biomass feedstocks, and biochar use in urban and rural applications. The main method applied was life cycle assessment, complemented with material flow analysis and energy systems modelling. In addition, a framework was developed to conceptualise and classify environmental effects of biochar in a life cycle perspective. The results showed that biochar systems can deliver more climate change mitigation than conventional bioenergy when energy systems are already rather decarbonised and if biochar stability is high. Biochar carbon sequestration provided the main climate change benefit, but smaller additional benefits were obtained from some material uses of biochar. When compared with reference systems, biochar solutions lead to shifts of burdens between sectors and environmental impact categories. It is possible to integrate pyrolysis to both large district heating networks and decentralised heating systems, but it will lead to a net increase in biomass consumption and related environmental impacts, relative to direct combustion of biomass. In the second half of the century, the need for management of biochar-containing soil masses will arise from today’s emerging urban applications. The case studies illustrated new uses of biochar and quantified several environmental benefits from biochar use. However, gaps remain between biochar effects present in the public discourse and their quantification in life cycle assessment. These differences were attributed to variability in the biochar effects, lack of knowledge, or inappropriate accounting framework. Overall, the thesis stresses the importance of analysing the potential of innovations to contribute to environmental goals by using parametrized life cycle models, depicting multiple contexts, and striving to identify suitability conditions rather than providing a definitive static answer.
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12. |
- Azzi, Elias, et al.
(author)
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Guidelines for estimation of biochar durability : Background report
- 2023
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Reports (other academic/artistic)abstract
- Biochar is produced by heating biomass in the total or partial absence of oxygen. This report addresses the long-term persistence of biochar in soil and how this can be managed in climate calculations and reporting. The report consists of this summary and four chapters, which can be read independently.Different terms have been used to describe the durability of biochar carbon storage, but also the physical presence of biochar in soils, e.g. persistence, permanence, recalcitrance, residence times, stability. Today, the term “durability of carbon storage” is preferred in policy contexts, but various academic disciplines such as soil science have other established terms like “persistence”. Here, both durability and persistence are used, rather interchangeably. It is important to be aware of differences in meaning that exist between disciplines.The purpose of this report is to present the state of knowledge regarding the proportion of carbon in biochar that remains in the soil over time and provide recommendations for calculating this. There is a need to calculate the persistence of biochar in soil for national climate reporting, corporate climate reporting, carbon credit trading, and life cycle assessments for various purposes.On the persistence of biocharThe amount of biochar remaining after a certain time depends on the properties of the biochar and the environment in which it is located. Nearly all research on biochar persistence has focused on its application in agricultural soils.The main reason for the high durability of biochar carbon storage is the formation of fused aromatic stable structures during biomass pyrolysis. A high degree of fused aromatic structures makes biochar much less prone to microbial decomposition than fresh biomass.Different biochars have different properties, and this influences how long they persist in the soil. To achieve biochar with properties that provide higher persistence, it should be produced at higher temperatures for a sufficient duration.Measuring and calculating biochar persistenceEstablished quantification methods of 100-year biochar persistence (e.g. referenced in IPCC inventory guidelines and used in voluntary carbon markets, to date) extrapolate short-term soil decomposition processes, and do not fully consider the processes that may explain millennial persistence.Calculations regarding biochar persistence have traditionally used a time span of 100 years to describe the amount of remaining carbon after a certain time. The use of specifically 100 years lacks a well founded scientific reason, but has been regarded as “far enough” into the future from a climate perspective and close enough for modelling to be meaningful.An active area of research relevant for the understanding biochar carbon storage durability is the development of advanced analytical characterisation methods of biochar that will enable measurement of the physicochemical heterogeneity in carbon structures present in biochar.Another area of continued research is biochar incubation, with a focus on field conditions, to elucidate both differences from laboratory conditions, and how transport processes affect biochar in the field.Recommendation and conclusionIn the project, available research data has been aggregated into a functional model that calculates how much of the carbon in biochar remains after a given number of years. The model is based on the H/C ratio of the biochar placed in the soil and the annual average temperature at the location.The model is made freely accessible to provide biochar market actors with the best available knowledge for estimating the durability of biochar carbon.Existing research results provide a sufficient foundation for estimation of the amount of biochar expected to remain over time. Future research results are expected to lead to increased knowledge regarding the decomposition properties of biochar, in particular biochars with a very low H/C ratio. Therefore, this recommendation will be revised by the end of the project in 2025.
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13. |
- Azzi, Elias, et al.
(author)
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Modelling biochar long-term carbon storage in soil with harmonized analysis of decomposition data
- 2024
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In: Geoderma. - 0016-7061 .- 1872-6259. ; 441
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Journal article (peer-reviewed)abstract
- The climate change mitigation benefits of biochar systems arise largely from carbon storage in biochar. However, while biochar is increasingly recognized as a carbon dioxide removal technology, there are on-going scientific discussions on how to estimate the persistence of biochar carbon when biochar is used in soils. Estimates vary from decades to millennia, building on different modelling approaches and evidence. Here, we revisited the persistence estimates derived from extrapolation of biochar incubation experiments, with the aims of making incubation data available, modelling choices transparent, and results reproducible. An extensive dataset of biochar incubations, including 129 biochar decomposition time series, was compiled and is made available alongside code for its analysis. Biochar persistence correlations were sensitive to data selection procedures and to the curve fitting modelling step, while soil temperature adjustments methods had less impact. Biochar H/C ratio remained the main predictor of biochar persistence, in line with previous research, regardless of the extrapolation assumptions (multi-pool exponential functions or power function) used in curve fitting. The relation between H/C and percentage of biochar carbon remaining after 100 years (BC100) was better explained by a power model than a linear model, with R2 values between 0.5 and 0.9. Using multi-pool exponential functions, estimated BC100 varied between 90 % and 60 % for H/C from 0 to 0.7. However, using power functions, BC100 was constrained between 90 % and 80 % for the same H/C range. Additional information about the biochar, the pyrolysis conditions or the environmental incubation conditions did not significantly increase explained variance. Notably, the dataset lacks observations at H/C ratios below 0.2, of biochar made from manure and biosolids, biochar from processes other than slow pyrolysis, field studies, and incubation temperatures below 10 °C, which should guide future experimental work. The detailed analysis performed in this study does not cast doubts on the longevity of biochar carbon storage; rather, it confirms previous knowledge by critically examining the modelling, elucidating the assumptions and limitations, and making the analysis fully reproducible. There is a need for further interdisciplinary work on integration of various theories and approaches to biochar persistence, ultimately leading to the formulation of policy-relevant conclusions.
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14. |
- Azzi, Elias, et al.
(author)
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Revisiting biochar decomposition data and long-term stability estimates: a transparent and reproducible analysis
- 2023
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Conference paper (other academic/artistic)abstract
- Accurately predicting the stability of a biochar sample placed in the environment is important for guiding climate policies and the emerging voluntary market for carbon removal. The stability of biochar in soils varies with feedstock type, pyrolysis parameters, and environmental conditions. Previous assessments have correlated biochar stability estimates to single features – like pyrolysis temperature, elemental molar ratios, or incubation duration – but these assessments used different datasets and methodologies and reached different conclusions. Therefore, our aim was to develop an open dataset of biochar decomposition experiments, and to develop a transparent data preparation and processing toolchain, enabling reproducibility of scientific results. We first made an inventory of all published biochar incubation experiments, and then collected the incubation data and an extensive set of associated metadata (i.e., biomass and biochar properties, pyrolysis and incubation conditions). In a second step, we developed a data analysis toolchain, including functions for extrapolation of the incubation data to longer times and models for correlation between metadata and estimated biochar stability. In the extrapolation step, the incubation data was fitted to decay functions. Care was taken to explore the effect of using different fitting algorithms and constraints, and to apply a recalibration of the incubation temperature. For the correlation step, several strategies were applied, including both single-feature linear regressions to reproduce previous results and multi-feature regressions based on decision trees. So far, a dataset of 135 observations with more than 8000 data elements was collected making it one of the largest biochar stability datasets available. For the first time, raw biochar decomposition data is also compiled for 111 observations (mostly laboratory incubations). The initial data exploration revealed that although pyrolysis temperatures in the range 350 to 700°C are well represented, there is a data gap at higher temperatures with only a few data points at 1200°C. Likewise, only two observations are available with a molar H/C ratio below 0.2. These gaps can guide design of future incubation studies, as these parameters are often seen as indicators of stability. During curve fitting with single, double, or triple exponential models, we noted that the choice of initial conditions was important for finding a good fit, but we also noted that in many cases fitting uncertainties were high, residuals were not necessarily randomly distributed, and that some observations did not fit well to any type of exponential model (likely due to experimental conditions). Nevertheless, we were able to approximately reproduce the fitting results reported in Woolf et al. (2021). Finally, linear correlations were established between predicted stability and pyrolysis temperature, molar H/C ratio, but also other features available in the dataset, yielding similar correlation coefficients as previously reported (0.1 to 0.4). Attempts to understand the variability in predicted stability (using principal component analysis) and to develop multi-variate and non-linear models have so far not significantly improved model performance without overfitting. Opportunities remain to use the compiled data for other types of modelling, e.g. in soil carbon models.
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15. |
- Azzi, Elias Sebastian, et al.
(author)
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Assessing the diverse environmental effects of biochar systems : An evaluation framework
- 2021
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In: Journal of Environmental Management. - : Elsevier BV. - 0301-4797 .- 1095-8630. ; 286
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Journal article (peer-reviewed)abstract
- 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.
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16. |
- Azzi, Elias Sebastian, et al.
(author)
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Life cycle assessment of urban uses of biochar and case study in Uppsala, Sweden
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Other publication (other academic/artistic)abstract
- Biochar is a material derived from biomass pyrolysis that is used in urban applications. The environmental impacts of new biochar products has however not been assessed. Here, the life cycle assessments of 5 biochar products were performed for 7 biochar supply-chains in 2 energy contexts. The biochar products (tree planting, green roofs, landscaping soil, charcrete, and biofilm carrier) were benchmarked against reference products and the 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 if biochar stability is high, all biochar products had a better climate performance than the reference, 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, depending on biochar supply-chains and materials substituted, with trade-offs between sectors and impact categories. This said, several use phase effects of biochar were not included in the assessment due to knowledge limitations. In Uppsala’s new district, biochar demand was around 1700 m3 year-1 during the 25 years of construction. By 2100, 23% of the biochar accumulated in landfills, raising questions for 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.
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17. |
- Azzi, Elias Sebastian, et al.
(author)
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Life cycle assessment of urban uses of biochar and case study in Uppsala, Sweden
- 2022
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In: Biochar. - : Springer Nature. - 2524-7972 .- 2524-7867. ; 4:1
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Journal article (peer-reviewed)abstract
- 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.
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18. |
- Azzi, Elias Sebastian, et al.
(author)
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Prospective Life Cycle Assessment of Large-Scale Biochar Production and Use for Negative Emissions in Stockholm
- 2019
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In: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 53:14, s. 8466-8476
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Journal article (peer-reviewed)abstract
- Several cities in Sweden are aiming for climate neutrality within a few decades and for negative emissions thereafter. Combined biochar, heat, and power production is an option to achieve carbon sequestration for cities relying on biomass-fuelled district heating, while biochar use could mitigate environmental pollution and greenhouse gas emissions from the agricultural sector. By using prospective life cycle assessment, the climate impact of the pyrolysis of woodchips in Stockholm is compared with two reference scenarios based on woodchip combustion. The pyrolysis of woodchips produces heat and power for the city of Stockholm, and biochar whose potential use as a feed and manure additive on Swedish dairy farms is explored. The climate change mitigation trade-off between bioenergy production and biochar carbon sequestration in Stockholm's context is dominated by the fate of marginal power. If decarbonisation of power is achieved, building a new pyrolysis plant becomes a better climate option than conventional combustion. Effects of cascading biochar use in animal husbandry are uncertain but could provide 10-20% more mitigation than direct biochar soil incorporation. These results help design regional biochar systems that combine negative carbon dioxide emissions with increased methane and nitrous oxide mitigation efforts and can also guide the development of minimum performance criteria for biochar products.
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19. |
- Azzi, Elias Sebastian, et al.
(author)
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Small-scale biochar production on Swedish farms : A model for estimating potential, variability, and environmental performance
- 2021
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In: Journal of Cleaner Production. - : Elsevier Ltd. - 0959-6526 .- 1879-1786. ; 280
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Journal article (peer-reviewed)abstract
- Several small-scale pyrolysis plants have been installed on Swedish farms and uptake is increasing in the Nordic countries. Pyrolysis plants convert biomass to biochar for agricultural applications and syngas for heating applications. These projects are driven by ambitions of achieving carbon dioxide removal, reducing environmental impacts, and improving farm finances and resilience. Before policy support for on-farm pyrolysis projects is implemented, a comprehensive environmental evaluation of these systems is needed. Here, a model was developed to jointly: (i) simulate operation of on-farm energy systems equipped with pyrolysis units; (ii) estimate biochar production potential and its variability under different energy demand situations and designs; and (iii) calculate life cycle environmental impacts. The model was applied to a case study farm in Sweden. The farm's heating system achieved net carbon dioxide removal through biochar carbon sequestration, but increased its impact in several other environmental categories, mainly due to increased biomass throughput. Proper dimensioning of heat-constrained systems is key to ensure optimal biochar production, as biochar production potential of the case farm was reduced under expected climate change in Sweden. To improve the environmental footprint of future biochar systems, it is crucial that expected co-benefits from biochar use in agriculture are realised. The model developed here is available for application to other cases.
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20. |
- Boström, Cecilia, et al.
(author)
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Design proposal of electrical system for linear generator wave power plants
- 2009
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In: 35TH ANNUAL CONFERENCE OF IEEE INDUSTRIAL ELECTRONICS. - : IEEE. - 9781424446483 - 9781424446506 ; , s. 4180-4185
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Conference paper (peer-reviewed)abstract
- This paper describes an electrical system layout for a wave power plant connecting linear generators to the grid. The electrical power out from the wave energy converters must be converted before they can be connected to the grid. The conversion is carried out in marine substations that will be placed on the seabed.The paper presents experimental power data from a wave energy converter that has been in operation at the Lysekil research site since March 2006. Moreover, results and analyses from experiments and simulations from tests with the generator connected to a rectifier and filter are presented. A simulation is made to show the difference between having the generator connected to a linear load and a nonlinear load, which would be the case when the generator is connected to the grid.
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21. |
- Cerutti, P. O., et al.
(author)
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The socioeconomic and environmental impacts of wood energy value chains in Sub-Saharan Africa : A systematic map protocol
- 2015
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In: Environmental Evidence. - : Springer Science and Business Media LLC. - 2047-2382. ; 4:1
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Journal article (peer-reviewed)abstract
- Background: The vast majority of households in Sub-Saharan Africa (SSA) depend on wood energy - comprising firewood and charcoal - for their daily energetic needs. Such consumption trends are expected to remain a common feature of SSA's wood energy production and supply chains, at least in the short- to medium-terms. Notwithstanding its importance, wood energy generally has low priority in SSA national policies. However, the use of wood energy is often considered a key driver of unsustainable management and negative environmental consequences in the humid and dry forests. To date, unsystematic assessments of the socio-economic and environmental consequences of wood energy use have underplayed its significance, thus further hampering policy debates. Therefore, a more balanced approach which considers both demand and supply dynamics is needed. This systematic map aims at providing a comprehensive approach to understanding the role and impacts of wood energy across all regions and aspects in SSA. Methods: The objective of this systematic map is to collate evidence from studies of environmental and socio-economic impacts of wood energy value chains, by considering both demand and supply within SSA. The map questions are framed using a Populations, Exposure, Comparators and Outcomes (PECO) approach. We name the supply and demand of wood energy as the "exposure," composed of wood energy production, harvesting, processing, and consumption. The populations of interest include both the actors involved in these activities and the forest sites where these activities occur. The comparator is defined as those cases where the same wood energy activities occur with i) available/accessible alternative energy sources, ii) regulatory frameworks that govern the sector and iii) alternative technologies for efficient use. The outcomes of interest encompass both socioeconomic and environmental impacts that can affect more than the populations named above. For instance, in addition to the direct socioeconomic impacts felt by participants in the wood energy value chain, forest dwellers may experience livelihood changes due to forest degradation caused by external harvesters. Moreover, intensified deforestation in one area may concurrently lead to forest regeneration in another.
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23. |
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24. |
- Ekenros, Linda, et al.
(author)
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Impact of Menstrual cycle-based Periodized training on Aerobic performance, a Clinical Trial study protocol—the IMPACT study
- 2024
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In: Trials. - : BioMed Central (BMC). - 1745-6215. ; 25:1
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Journal article (peer-reviewed)abstract
- Background: The menstrual cycle and its impact on training and performance are of growing interest. However, evidence is lacking whether periodized exercise based on the menstrual cycle is beneficial. The primary purpose of this proposed randomized, controlled trial, the IMPACT study, is to evaluate the effect of exercise periodization during different phases of the menstrual cycle, i.e., comparing follicular phase-based and luteal phase-based training with regular training during the menstrual cycle on physical performance in well-trained women.Methods: Healthy, well-trained, eumenorrheic women between 18 and 35 years (n = 120) will be recruited and first assessed for physical performance during a run-in menstrual cycle at different cycle phases and then randomized to three different interventions: follicular phase-based training, luteal phase-based training, or regular training during three menstrual cycles. The training intervention will consist of high-intensity spinning classes followed by strength training. The menstrual cycle phases will be determined by serum hormone analysis throughout the intervention period. Assessment of aerobic performance (primary outcome) and muscle strength, body composition, and blood markers will be performed at baseline and at the end of the intervention.Discussion: With a robust methodology, this study has the potential to provide evidence of the differential effects of exercise periodization during different phases of the menstrual cycle in female athletes.Trial registration: ClinicalTrials.gov NCT05697263 . Registered on 25 January 2023
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25. |
- Eklind, Ylva, et al.
(author)
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Carbon Turnover and Ammonia Emissions during Composting of Biowaste at Different Temperatures
- 2007
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In: Journal of Environmental Quality. - : Wiley. - 0047-2425 .- 1537-2537. ; 36:5, s. 1512-1520
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Journal article (peer-reviewed)abstract
- The effects of different process temperatures (40, 55, and 67°C) during composting of source-separated household waste were studied in a 200 L compost reactor at an oxygen concentration of 16%. The overall decomposition measured as carbon mineralization, decomposition of different carbon constituents, and the dynamics of nitrogen mineralization and the microbial community, are reported. Ammonia emissions at 67°C were more than double those at lower temperatures, and they were lowest at 40°C. The decomposition rate, measured as CO2 emission, was highest at 55°C. Decomposition of crude fat was slower at 40°C than at 55 and 67°C. The peak in microbial biomass was largest in the run at 40°C, where substantial differences were seen in the microbial community structure and succession compared to thermophilic temperatures. Biowaste composting can be optimized to obtain both a high decomposition rate and low ammonia emissions by controlling the process at about 55°C in the initial, high-rate stage. To reduce ammonia emissions it seems worthwhile to reduce the temperature after an initial high-temperature stage.
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