| 1. |
- Beal, Jacob, et al.
(författare)
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Robust estimation of bacterial cell count from optical density
- 2020
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Ingår i: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
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Tidskriftsartikel (refereegranskat)abstract
- Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data.
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| 2. |
- Dimitriou, Ioannis, et al.
(författare)
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A RANDOM ACCESS G-NETWORK: STABILITY, STABLE THROUGHPUT, AND QUEUEING ANALYSIS
- 2021
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Ingår i: Probability in the engineering and informational sciences (Print). - : CAMBRIDGE UNIV PRESS. - 0269-9648 .- 1469-8951. ; 35:1, s. 111-137
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Tidskriftsartikel (refereegranskat)abstract
- The effect of signals on stability, stable throughput region, and delay in a two-user slotted ALOHA-based random-access system with collisions is considered. This work gives rise to the development of random access G-networks, which can model security attacks, expiration of deadlines, or other malfunctions, and introduce load balancing among highly interacting queues. The users are equipped with infinite capacity buffers accepting external bursty arrivals. We consider both negative and triggering signals. Negative signals delete a packet from a user queue, while triggering signals cause the instantaneous transfer of packets among user queues. We obtain the exact stability region, and show that the stable throughput region is a subset of it. Moreover, we perform a compact mathematical analysis to obtain exact expressions for the queueing delay by solving a non-homogeneous Riemann boundary value problem. A computationally efficient way to obtain explicit bounds for the expected number of buffered packets at user queues is also presented. The theoretical findings are numerically evaluated and insights regarding the system performance are derived.
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| 3. |
- Dimitriou, Ioannis
(författare)
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Bio-hubs as keys to successful biomass supply integration for bioenergy within the bioeconomy : Report from joint IEA Bioenergy task 43 & BioEast initiative workshop 10th October 2019, Sopron, Hungary
- 2020
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Rapport (refereegranskat)abstract
- IEA Bioenergy Task 43: Sustainable Biomass Supply Integration for Bioenergy Within the Broader Bioeconomy has launched an initiative to identify successful examples of biomass logistic and distribution points for bioenergy and the bioeconomy: bio-hubs. The goal of this initiative is to explore integrated bioeconomy supply chains to develop solutions for the reliable production and supply of higher-quality biomass for energy. These examples are also meant to serve as sources of inspiration that other biomass producers can use to enhance the sustainability of their own activities, as well as for policy makers to familiarize themselves with the bio-hub concept.The Sopron workshop took bioenergy a step forward towards new biomass supply chains within a concept of bioeconomy. The innovative examples selected for this workshop show how biomass can be produced together with wood products and food in sustainably managed landscapes. The aim of the workshop was to develop a framework for the successful establishment of bio-hubs in support of the bioeconomy. The workshop had a proactive format, consisting of showcase presentations and participatory SWOT analysis. Examples of four existing and emerging bio-hubs were presented, and workshop participants had the opportunity to consider how different biomass supply chains (forestry, agriculture, SRC) could evolve to bio-hub concepts. In the second part of the workshop, biomass as a commodity was presented. Participants jointly outlined strengths, weaknesses, opportunities and threats (SWOT analysis) of having bio-hub as an alternative to the existing biomass supply. The SWOT analysis was performed in real -time, capturing, scoring and ranking inputs from 30 workshop attendees using the Sli.do application. The joint IEA Bioenergy Task 43 and BioEast Initiative workshop was well attended with 55 participants from 17 countries. Most participants (64%) were from the BioEast macro-region and 90% of participants from the EU, but reaching as far as to Australia, Canada and New Zealand (10%).BioEast Initiative and IEA Bioenergy foresee that the gathered knowledge and shared experience at the workshop will contribute to the improvement of sustainable biomass mobilisation for energy purposes, notably in the BioEast macro-region and in other member countries of the IEA Bioenergy Technology Collaboration Programme. The results of the workshop will feed into the development of the framework for bio-hubs, which will then be further applied and tested as part of following activities.To access the workshop presentations, please visit the IEA Bioenergy Task 43 website.
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| 4. |
- Dimitriou, Ioannis, et al.
(författare)
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From preferences to concerted policy on mandated share for renewable energy in transport
- 2021
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Ingår i: Energy Policy. - : Elsevier BV. - 0301-4215 .- 1873-6777. ; 155
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Tidskriftsartikel (refereegranskat)abstract
- Environmental, energy, transport and agriculture policies are intersecting when deciding on renewable energy in transport (RES-T) implementation strategies. The uncertainty related to the advanced biofuels, limitations and underperformance of readily available technologies for decarbonization of transport sector challenges RES-T policy making. This paper employs partitioning as a choice architecture tool to create a concerted RES-T policy. The approach collects the preferred attributes of an alternative fuel rather than the preferred fuel by guiding stakeholders through RES-T policy, ensuring that all aspects of concerted policy are covered. Fuzzy analytical hierarchical process (fAHP) has been superimposed on the partitioning related to the biofuels to mathematically weight the alternatives. fAHP ranks the weighted preferences on biofuels to build a consensus among stakeholder groups, later translated to the actual RES-T mix, quantities and investments needed to meet the mandated share. Applied on Croatia, the preferences of three stakeholder groups were weighted and ranked; whereas some discrepancies were identified, the consensus outlined the national transport decarbonization policy with related investments. When the consensual RES-T mix contrasted with the least-cost alternative, the investment needed was reduced to a quarter. The collaborative management process proved to be a time-effective participatory approach for a silo-based policy structure.
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| 5. |
- Dimitriou, Ioannis
(författare)
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Long-Term Effects of Soil Remediation with Willow Short Rotation Coppice on Biogeographic Pattern of Microbial Functional Genes
- 2022
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Ingår i: Microorganisms. - : MDPI AG. - 2076-2607. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Short rotation coppice (SRC) is increasingly being adopted for bioenergy production, pollution remediation and land restoration. However, its long-term effects on soil microbial communities are poorly characterized. Here, we studied soil microbial functional genes and their biogeographic pattern under SRC with willow trees as compared to those under permanent grassland (C). GeoChip analysis showed a lower functional gene diversity in SRC than in C soil, whereas microbial ATP and respiration did not change. The SRC soil had lower relative abundances of microbial genes encoding for metal(-oid) resistance, antibiotic resistance and stress-related proteins. This indicates a more benign habitat under SRC for microbial communities after relieving heavy metal stress, consistent with the lower phytoavailability of some metals (i.e., As, Cd, Ni and Zn) and higher total organic carbon, NO3--N and P concentrations. The microbial taxa-area relationship was valid in both soils, but the space turnover rate was higher under SRC within 0.125 m(2), which was possibly linked to a more benign environment under SRC, whereas similar values were reached beyond thisarea. Overall, we concluded that SRC management can be considered as a phytotechnology that ameliorates the habitat for soil microorganisms, owing to TOC and nutrient enrichment on the long-term.
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| 6. |
- Dimitriou, Ioannis, et al.
(författare)
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Positioning the biofuel policy in the bioeconomy of the BioEast macro-region
- 2022
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Ingår i: Biofuels. - : Informa UK Limited. - 1759-7269 .- 1759-7277. ; 13, s. 833-842
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Tidskriftsartikel (refereegranskat)abstract
- This study outlines and reviews the concerted biofuels' policy for transport of eleven countries in central and eastern Europe (BioEast macro-region). Policy preferences collected from relevant government representatives of the region are analyzed using choice architecture and fuzzy Analytical Hierarchy Process. The experts' preferences concerning criteria related to land use, decarbonization and development of a national market are ranked with similar importance, with a slight preference for the latter. The results demonstrate a great variation in the priorities for forming and implementing biofuel policies in the region, strongly related to national realities (e.g. available land for biofuel production, target fulfilment). Countries delaying in their biofuel targets aim at policies that fulfil internal demands without considering other criteria related to land use issues and own sources. The results show a general agreement (95% consensus) of having about 66% of renewable energy in transport covered from biofuels resulting from domestic biomass supply. Yet, there are differing preferences in the policy options at country level, which makes a single consensus policy for the macro-region challenging. Finally, the results highlight the different degrees of policy intervention that are implicit in the policy preferences of the national decision makers.
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| 7. |
- Dimitriou, Ioannis
(författare)
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The Contributions of Biomass Supply for Bioenergy in the Post-COVID-19 Recovery
- 2021
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Ingår i: Energies. - : MDPI AG. - 1996-1073. ; 14
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Tidskriftsartikel (refereegranskat)abstract
- This research investigates how biomass supply chains (BSChs) for bioenergy within the broader bioeconomy could contribute to the post-COVID-19 recovery in three dimensions: boosting economic growth, creating jobs, and building more resilient and cleaner energy systems in four future scenarios, in the short term (by 2023) and long term (by 2030). A SWOT analysis on BSChs was used for generating a questionnaire for foresight by a two-round Delphi study. To interpret the results properly, a short survey and literature review is executed to record BSChs behavior during the pandemic. In total, 23 (55% response rate) and 28 (46% response rate) biomass experts from three continents participated in the Delphi and the short survey, respectively. The strongest impact from investment in BSChs would be on economic growth, followed by a contribution to the resilient and cleaner energy systems and job creation. The effects would be more visible in the long- than in the short-term period. Investments with the most impact on recovery are those that improve biomass material efficiency and circularity. Refurbishment of current policies to enhance the supply of biomass as a renewable resource to the future economy is a must.
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| 8. |
- Englund, Oskar, et al.
(författare)
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Beneficial land-use change in Europe : deployment scenarios for multifunctional riparian buffers and windbreaks
- 2024
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- The land sector needs to increase biomass production to meet multiple demands while reducing negative land use impacts and transitioning from being a source to being a sink of carbon. The new Common Agricultural Policy of the EU (CAP) steers towards a more needs-based, targeted approach to addressing multiple environmental and climatic objectives, in coherence with other EU policies. In relation to this, new schemes are developed to offer farmers direct payments to adapt practices beneficial for climate, water, soil, air and biodiversity. Multifunctional biomass production systems have potential to reduce environmental impacts from agriculture while maintaining or increasing biomass production for the bioeconomy across Europe. Here, we present the first attempt to model the deployment of two such systems, riparian buffers and windbreaks, across >81.000 landscapes in Europe (EU27 + UK), aiming to quantify the resulting ecosystem services and environmental benefits, considering three deployment scenarios with different incentives for implementation. We found that these multifunctional biomass production systems can reduce N emissions to water and soil loss by wind erosion, respectively, down to a “low” impact level all over Europe, while simultaneously providing substantial environmental co-benefits, using less than 1% of the area under annual crops in the EU. The GHG emissions savings of utilizing the biomass produced in these systems for replacing fossil alternatives, combined with the increases in soil organic carbon, correspond to 1-1,4% of total GHG emissions in EU28. The introduction of “eco-schemes” in the new CAP may resolve some of the main barriers to implementation of large-scale multifunctional biomass production systems. Increasing the knowledge of these opportunities among all EU member states, before designing and introducing country-specific Eco-scheme options in the new CAP, is critical.
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| 9. |
- Englund, Oskar, et al.
(författare)
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Beneficial land use change: Strategic expansion of new biomass plantations can reduce environmental impacts from EU agriculture
- 2020
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Ingår i: Global Environmental Change. - : Elsevier BV. - 0959-3780 .- 1872-9495. ; 60
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Tidskriftsartikel (refereegranskat)abstract
- Society faces the double challenge of increasing biomass production to meet the future demands for food, materials and bioenergy, while addressing negative impacts of current (and future) land use. In the discourse, land use change (LUC) has often been considered as negative, referring to impacts of deforestation and expansion of biomass plantations. However, strategic establishment of suitable perennial production systems in agricultural landscapes can mitigate environmental impacts of current crop production, while providing biomass for the bioeconomy. Here, we explore the potential for such “beneficial LUC” in EU28. First, we map and quantify the degree of accumulated soil organic carbon losses, soil loss by wind and water erosion, nitrogen emissions to water, and recurring floods, in ∼81.000 individual landscapes in EU28. We then estimate the effectiveness in mitigating these impacts through establishment of perennial plants, in each landscape. The results indicate that there is a substantial potential for effective impact mitigation. Depending on criteria selection, 10–46% of the land used for annual crop production in EU28 is located in landscapes that could be considered priority areas for beneficial LUC. These areas are scattered all over Europe, but there are notable “hot-spots” where priority areas are concentrated, e.g., large parts of Denmark, western UK, The Po valley in Italy, and the Danube basin. While some policy developments support beneficial LUC, implementation could benefit from attempts to realize synergies between different Sustainable Development Goals, e.g., “Zero hunger”, “Clean water and sanitation”, “Affordable and Clean Energy”, “Climate Action”, and “Life on Land”.
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| 10. |
- Englund, Oskar, 1982, et al.
(författare)
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Large-scale deployment of grass in crop rotations as a multifunctional climate mitigation strategy
- 2023
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Ingår i: GCB Bioenergy. - : Wiley. - 1757-1707 .- 1757-1693. ; 15:2, s. 166-184
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Tidskriftsartikel (refereegranskat)abstract
- The agriculture sector can contribute to climate change mitigation by reducing its own greenhouse gas (GHG) emissions, sequestering carbon in vegetation and soils, and providing biomass to substitute for fossil fuels and other GHG-intensive products. The sector also needs to address water, soil, and biodiversity impacts caused by historic and current practices. Emerging EU policies create incentives for cultivation of perennial plants that provide biomass along with environmental benefits. One such option, common in northern Europe, is to include grass in rotations with annual crops to provide biomass while remediating soil organic carbon (SOC) losses and other environmental impacts. Here, we apply a spatially explicit model on >81,000 sub-watersheds in EU27 + UK (Europe) to explore the effects of widespread deployment of such systems. Based on current accumulated SOC losses in individual sub-watersheds, the model identifies and quantifies suitable areas for increased grass cultivation and corresponding biomass- and protein supply, SOC sequestration, and reductions in nitrogen emissions to water as well as wind and water erosion. The model also provides information about possible flood mitigation. The results indicate a substantial climate mitigation potential, with combined annual GHG savings from soil-carbon sequestration and displacement of natural gas with biogas from grass-based biorefineries, equivalent to 13%–48% of current GHG emissions from agriculture in Europe. The environmental co-benefits are also notable, in some cases exceeding the estimated mitigation needs. Yield increases for annual crops in modified rotations mitigate the displacement effect of increasing grass cultivation. If the grass is used as feedstock in lieu of annual crops, the displacement effect can even be negative, that is, a reduced need for annual crop production elsewhere. Incentivizing widespread deployment will require supportive policy measures as well as new uses of grass biomass, for example, as feedstock for green biorefineries producing protein concentrate, biofuels, and other bio-based products.
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