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- ItemAn extended hybrid input-output model applied to fossil- and bio-based plastics(Amsterdam [u.a.] : Elsevier, 2021) Jander, WiebkeMatrix augmentation method is developed further and described transparently for enabling more specific input-output analyses of bio- vs. fossil-based sectors. A number of economic and environmental effects of substitution can be estimated, compared, and managed. While the model was applied for the first time to the German plastics industry, it can be well integrated into existing bioeconomy monitorings to represent substitution in sectors and countries. • Original matrix augmentation method is described in much detail for the first time considering available data for bio- and fossil-based industries. • Particular attention is paid to balancing cost and benefit in model building so that indicators can be integrated in a continuous monitoring of the bioeconomy. Hence, industry data is prefered to process data whenever possible. • Input structures of bio-based imports are considered in single-region input-output analysis.
- ItemMethane emissions from the storage of liquid dairy manure: Influences of season, temperature and storage duration(Amsterdam [u.a.] : Elsevier, 2021) Cárdenas, Aura; Ammon, Christian; Schumacher, Britt; Stinner, Walter; Herrmann, Christiane; Schneider, Marcel; Weinrich, Sören; Fischer, Peter; Amon, Thomas; Amon, BarbaraMethane emissions from livestock manure are primary contributors to GHG emissions from agriculture and options for their mitigation must be found. This paper presents the results of a study on methane emissions from stored liquid dairy cow manure during summer and winter storage periods. Manure from the summer and winter season was stored under controlled conditions in barrels at ambient temperature to simulate manure storage conditions. Methane emissions from the manure samples from the winter season were measured in two time periods: 0 to 69 and 0 to 139 days. For the summer storage period, the experiments covered four time periods: from 0 to 70, 0 to 138, 0 to 209, and 0 to 279 continuous days, with probing every 10 weeks. Additionally, at the end of all storage experiments, samples were placed into eudiometer batch digesters, and their methane emissions were measured at 20 °C for another 60 days to investigate the potential effect of the aging of the liquid manure on its methane emissions. The experiment showed that the methane emissions from manure stored in summer were considerably higher than those from manure stored in winter. CH4 production started after approximately one month, reaching values of 0.061 kg CH4 kg−1 Volatile Solid (VS) and achieving high total emissions of 0.148 kg CH4 kg−1 VS (40 weeks). In winter, the highest emissions level was 0.0011 kg CH4 kg−1 VS (20 weeks). The outcomes of these experimental measurements can be used to suggest strategies for mitigating methane emissions from manure storage.
- ItemSustainable food protein supply reconciling human and ecosystem health: A Leibniz Position(Amsterdam [u.a.] : Elsevier, 2020) Weindl, Isabelle; Ost, Mario; Wiedmer, Petra; Schreiner, Monika; Neugart, Susanne; Klopsch, Rebecca; Kühnhold, Holger; Kloas, Werner; Henkel, Ina M.; Schlüter, Oliver; Bußler, Sara; Bellingrath-Kimura, Sonoko D.; Ma, Hua; Grune, Tilman; Rolinski, Susanne; Klaus, SusanneMany global health risks are related to what and how much we eat. At the same time, the production of food, especially from animal origin, contributes to environmental change at a scale that threatens boundaries of a safe operating space for humanity. Here we outline viable solutions how to reconcile healthy protein consumption and sustainable protein production which requires a solid, interdisciplinary evidence base. We review the role of proteins for human and ecosystem health, including physiological effects of dietary proteins, production potentials from agricultural and aquaculture systems, environmental impacts of protein production, and mitigation potentials of transforming current production systems. Various protein sources from plant and animal origin, including insects and fish, are discussed in the light of their health and environmental implications. Integration of available knowledge is essential to move from a dual problem description (“healthy diets versus environment”) towards approaches that frame the food challenge of reconciling human and ecosystem health in the context of planetary health. This endeavor requires a shifting focus from metrics at the level of macronutrients to whole diets and a better understanding of the full cascade of health effects caused by dietary proteins, including health risks from food-related environmental degradation. © 2020
- ItemExperimental evaluation and application of genetic programming to develop predictive correlations for hydrochar higher heating value and yield to optimize the energy content(Amsterdam [u.a.] : Elsevier, 2022) Marzban, Nader; Libra, Judy A.; Hosseini, Seyyed Hossein; Fischer, Marcus G.; Rotter, Vera SusanneThe hydrothermal carbonization (HTC) process has been found to consistently improve biomass fuel characteristics by raising the higher heating value (HHV) of the hydrochar as process severity is increased. However, this is usually associated with a decrease in the solid yield (SY) of hydrochar, making it difficult to determine the optimal operating conditions to obtain the highest energy yield (EY), which combines the two parameters. In this study, a graph-based genetic programming (GP) method was used for developing correlations to predict HHV, SY, and EY for hydrochars based on published values from 42 biomasses and a broad range of HTC experimental systems and operating conditions, i.e., 5 ≤ holding time (min) ≤ 2208, 120 ≤ temperature (°C) ≤ 300, and 0. 0096 ≤ biomass to water ratio ≤ 0.5. In addition, experiments were carried out with 5 pomaces at 4 temperatures and two reactor scales, 1 L and 18.75 L. The correlations were evaluated using this experimental data set in order to estimate prediction errors in similar experimental systems. The use of the correlations to predict HTC conditions to achieve the maximum EY is demonstrated for three common feedstocks, wheat straw, sewage sludge, and a fruit pomace. The prediction was confirmed experimentally with pomace at the optimized HTC conditions; we observed 6.9 % error between the measured and predicted EY %. The results show that the correlations can be used to predict the optimal operating conditions to produce hydrochar with the desired fuel characteristics with a minimum of actual HTC runs.
- ItemMeasures to increase the nitrogen use efficiency of European agricultural production(Amsterdam [u.a.] : Elsevier, 2020) Hutchings, Nicholas J.; Sørensen, Peter; Cordovil, Cláudia M.d.S.; Leip, Adrian; Amon, BarbaraInputs of nitrogen to agricultural production systems are necessary to produce food, feed and fibre, but nitrogen (N) losses from those systems represent a waste of a resource and a threat to both the environment and human health. The nitrogen use efficiency (NUE) of an agricultural production system can be seen as an indicator of the balance between benefits and costs of primary food, feed and fibre production. Here, we used modelling to follow the fate of the virgin N input to different production systems (ruminant and granivore meat, dairy, arable), and to estimate their NUE at the system scale. We defined two ruminant meat production systems, depending on whether the land places constraints on farming practices. The other production systems were dairy, granivore and arable production on land without constraints. Two geographic regions were considered: Northern and Southern Europe. Measures to improve NUE were identified and allocated to Low, Medium and High ambition groups, with Low equating to the current situation in Europe for production systems that are broadly following good agricultural practice. The NUE of the production systems was similar to or higher in Southern than Northern Europe, with the maximum technical NUEs if all available measures are implemented were for North and South Europe, respectively, 82% and 92% for arable systems, 71% and 80% for granivores, 50% and 36% for ruminant meat production on constrained land, 53% and 55% for dairy production on unconstrained land and 46% and 62% for ruminant meat production on unconstrained land. The values for NUE found here tend to be higher than reported elsewhere, possibly due to the accounting for long-term residual effects of fertiliser and manure in our method. The greatest increase in NUE with the progressive implementation of higher ambition measures was in unconstrained granivore systems and the least was in constrained ruminant meat systems, reflecting the lower initial NUE of granivore systems and the larger number of measures applicable to confined livestock systems. Our work supports use of NUE as an indicator of the temporal trend in the costs and benefits of existing agricultural production systems, but highlights problems associated with its use as a sustainability criteria for livestock production systems. For arable systems, we consider well-founded the NUE value of 90% above which there is a high risk of soil N depletion, provided many measures to increase NUE are employed. For systems employing fewer measures, we suggest a value of 70% would be more appropriate. We conclude that while it is feasible to calculate the NUE of livestock production systems, the additional complexity required reduces its value as an indicator for benchmarking sustainability in practical agriculture. © 2020 The Authors
- ItemIntegrative programming for simulation of packaging headspace and shelf life of fresh produce(Amsterdam [u.a.] : Elsevier, 2021) Jalali, Ali; Linke, Manfred; Geyer, Martin; Mahajan, PramodFresh horticultural products are exposed to different environmental conditions from farm to fork. Barrier properties of packaging and physiological behaviour of produce, namely respiration and transpiration can affect headspace conditions surrounding produce and consequently remaining shelf life. Packaging material also plays a role in heat and mass transfer, such as thermal conduction and permeation of O2, CO2 and water vapour. All of these behaviours are integrated together in the form of ordinary differential equations and solved using numerical methods in MATLAB. • The simulation program is useful for designing the size and number of perforations to achieve equilibrium modified atmosphere alone or in combination with packaging material having a higher water transmission rate or active moisture absorber. • The simulation program is also useful for predicting the shelf life of fresh produce under the actual supply chain conditions. • The simulation program provides a flexible system to input predefined supply chain conditions and the properties of fresh produce and packaging material, thus, minimizing the costly and time consuming experimental procedures for selecting the optimum packaging material for fresh produce.
- ItemLaser induced diffuse reflectance imaging – Monte Carlo simulation of backscattering measured on the surface(Amsterdam [u.a.] : Elsevier, 2020) Baranyai, LászlóThe Monte Carlo simulation algorithm of photon trajectory computation is implemented in object oriented R code. Diffuse reflectance, also called backscattering, is modeled in semi-infinite homogeneous media. Spatial photon flux leaving the surface of the media is collected. The profile of intensity along radii relative to the incident point is used to simulate measurement of computer vision systems. Four optical parameters of the media are used: absorption coefficient, scattering coefficient, anisotropy factor and refractive index. Five parameters are used to describe configuration of the vision system: number of photons, radius of circular light beam, limiting energy level of photons, radius of observed area, spatial resolution of the vision system. • The incident angle of the light beam is included in the photon launch procedure. Initial direction is typically assumed to be normal with x,y,z coordinates of 0,0,1. In the proposed modification, initial move vector is calculated based on the incident angle and refractive index of the media. Additionally, elliptic distortion of the circular light beam on the surface is calculated based on the incident angle. • Photon flux leaving media through the surface is corrected with Lambertian method to measure intensity captured by an imaging device in normal position. • The software implementing the method is written in R language, the R code is available as standard package.