502 research outputs found
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Energy intensity and global warming potential of corn grain ethanol production in Wisconsin (USA)
Increasing demand for renewable alternative fuels, such as ethanol, is driven by decreasing availability of fossil resources and increasing attention to climate change. Life cycle assessment (LCA) is the tool used to evaluate environmental impacts, such as energy intensity (EI) and global warming potential (GWP), from ethanol production, but the application of this tool varies greatly. The goals of this study were to enumerate the life cycle EI, net energy value (NEV), and GWP of corn grain ethanol production in Wisconsin, to explore ethanol production scenarios which differ at the treatment of the whole stillage (WS) coproduct, and to evaluate the various solutions to the multifunctionality problem which arises in LCA. In Scenario 1, all suggested solutions to the multifunctionality problem are considered by transforming WS into the animal feed dried distillers grains with solubles (DDGS). Scenario 2 avoids allocation using an integrated system which recycles the WS with an anaerobic biodigester and a combined heat and power (CHP) plant to provide electricity and steam to the ethanol refinery and returns the residue to the land as fertilizer. Based on the Scenario 1 analysis, we recommend the use of the subdivision (SD) solution to the multifunctionality problem because it enables clear comparisons between different ethanol production systems, it distinguishes between the environmental impacts from ethanol production and coproduct processing and it reduces the number of assumptions in the LCA calculations. From the comparison of both scenarios, we find that recycling the WS into electricity, heat, and fertilizer is the most environmentally beneficial coproduct use because it results in a 54% lower EI and a 67% lower GWP than the processing of WS into DDGS
Water footprint analysis for the assessment of milk production in Brandenburg (Germany)
The working group "Adaptation to Climate Change" at the Leibniz-Institute for Agricultural Engineering Potsdam-Bornim (ATB) is introduced. This group calculates the water footprint for agricultural processes and farms, distinguished into green water footprint, blue water footprint, and dilution water footprint.
The green and blue water demand of a dairy farm plays a pivotal role in the regional water balance. Considering already existing and forthcoming climate change effects there is a need to determine the water cycle in the field and in housing for process chain optimisation for the adaptation to an expected increasing water scarcity. Resulting investments to boost water productivity and to improve water use efficiency in milk production are two pathways to adapt to climate change effects.
In this paper the calculation of blue water demand for dairy farming in Brandenburg (Germany) is presented. The water used for feeding, milk processing, and servicing of cows over the time period of ten years was assessed in our study. The preliminary results of the calculation of the direct blue water footprint shows a decreasing water demand in the dairy production from the year 1999 with 5.98×109 L/yr to a water demand of 5.00×109 L/yr in the year 2008 in Brandenburg because of decreasing animal numbers and an improved average milk yield per cow. Improved feeding practices and shifted breeding to greater-volume producing Holstein-Friesian cow allow the production of milk in a more water sustainable way. The mean blue water consumption for the production of 1 kg milk in the time period between 1999 to 2008 was 3.94±0.29 L.
The main part of the consumed water seems to stem from indirect used green water for the production of feed for the cows
Synthetic beta-solenoid proteins with the fragment-free computational design of a beta-hairpin extension
The ability to design and construct structures with atomic level precision is one of the key goals of nanotechnology. Proteins offer an attractive target for atomic design, as they can be synthesized chemically or biologically, and can self-assemble. However the generalized protein folding and design problem is unsolved. One approach to simplifying the problem is to use a repetitive protein as a scaffold. Repeat proteins are intrinsically modular, and their folding and structures are better understood than large globular domains. Here, we have developed a new class of synthetic repeat protein, based on the pentapeptide repeat family of beta-solenoid proteins. We have constructed length variants of the basic scaffold, and computationally designed de novo loops projecting from the scaffold core. The experimentally solved 3.56 ËšA resolution crystal structure of one designed loop matches closely the designed hairpin structure, showing the computational design of a backbone extension onto a synthetic protein core without the use of backbone fragments from known structures. Two other loop designs were not clearly resolved in the crystal structures and one loop appeared to be in an incorrect conformation. We have also shown that the repeat unit can accommodate whole domain insertions by inserting a domain into one of the designed loops
Modeling the water demand on farms
The decreasing availability of water caused by depletion and climate change combined with a growing world population requires the productive use of water now and in the future. The young researcher group "AgroHyd" at the Leibniz-Institute for Agricultural Engineering Potsdam-Bornim (ATB) is currently modeling the water demand for agricultural processes at the farm scale and developing indicators to link the hydrological and agricultural perspectives. The aim of the group is to increase productivity in agriculture by raising water productivity in plant production and livestock farming. The effects of various agronomic measures, individual and in combination, on water productivity are assessed using several indicators. Scenarios of agricultural measures, climate and diets are used to test to what extent the water demand for food production will increase due to growing global change in different regions of the world
Priorities for energy efficiency measures in agriculture.
This report provides a compilation of energy efficiency measures in agriculture, their
opportunities and constraints to implement energy efficient agricultural systems across
Europe as a result of the AGREE (Agriculture & Energy Efficiency) Coordination and Support
Action funded by the 7th research framework of the EU (www.agree.aua.gr). The report
dwells on earlier reports of the consortium, which listed potential energy efficiency
measures (Project Deliverable 2.3: Energy Saving Measures in Agriculture – Overview on the Basis of National Reports) and identified trade-offs and win-win situations of various energy efficiency measures in agriculture (Project Deliverable 3.1: Economic and environmental
analysis of energy efficiency measures in agriculture). It shows research gaps in crop
production, greenhouse production, animal husbandry and system approaches, which can
be regarded as priorities for energy efficiency measures in agriculture. The report is na important input for the strategic research agenda, which is one of the main outputs of the AGREE project
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Grain Size And Cap Layer Effects On Electromigration Reliability Of Cu Interconnects: Experiments And Simulation
This paper combined experiments and simulation to investigate the grain size and cap layer effects on electromigration (EM) reliability of Cu interconnects. First the statistical distribution of EM lifetime and failure modes were examined for in laid Cu interconnects of large and small grain structures with two different cap layers of SiCN vs. CoWP. The CoWP cap was found to significantly improve the EM lifetime due to the suppression of the interfacial mass transport as a result of strengthening of the Cu/cap interface bonding. In addition, the grain size was observed to affect the EM reliability significantly, particularly for the CoWP capped structures. Resistance traces and failure analysis revealed two distinct failure modes: mode I with voids formed near the cathode via corner and mode II with voids formed in the trench several microns away from the cathode via. It was found that large grain size and strong cap interface reduced the mass transport rate and the void diffusion in the Cu line, leading to a longer EM lifetime and a higher proportion of mode II failures. A statistical simulation of EM lifetimes was also applied to Cu interconnects with grain structures generated by the Monte Carlo method. The simulation results for different grain sizes and cap interfaces are in good agreement with the experimental observations.Microelectronics Research Cente
Down a rabbit hole: burrowing behaviour and larger home ranges are related to larger brains in leporids
Studies on the evolution of brain size variation usually focus on large clades encompassing broad phylogenetic groups. This risks introducing ‘noise’ in the results, often obscuring effects that might be detected in less inclusive clades. Here, we focus on a sample of endocranial volumes (endocasts) of 18 species of rabbits and hares (Lagomorpha: Leporidae), which are a discrete radiation of mammals with a suitably large range of body sizes. Using 60 individuals, we test five popular hypotheses on brain size and olfactory bulb evolution in mammals. We also address the pervasive issue of missing data, using multiple phylogenetic imputations as to conserve the full sample size for all analyses. Our analyses show that home range and burrowing behaviour are the only predictors of leporid brain size variation. Litter size, which is one of the most widely reported constraints on brain size, was unexpectedly not associated with brain size. However, a constraining effect may be masked by a strong association of litter size with temperature seasonality, warranting further study. Lastly, we show that unreasonable estimations of phylogenetic signal (Pagel’s lamba) warrant additional caution when using small sample sizes, such as ours, in comparative studies
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Performative Work: Bridging Performativity and Institutional Theory in the Responsible Investment Field
Callon’s performativity thesis has illuminated how economic theories and calculative devices shape markets, but has been challenged for its neglect of the organizational, institutional and political context. Our seven-year qualitative study of a large financial data company found that the company’s initial attempt to change the responsible investment field through a performative approach failed because of the constraints posed by field practices and organizational norms on the design of the calculative device. However, the company was subsequently able to put in place another form of performativity by attending to the normative and regulative associations of the device. We theorize this route to performativity by proposing the concept of performative work, which designates the necessary institutional work to enable translation and the subsequent adoption of the device. We conclude by considering the implications of performative work for the performativity and the institutional work literatures
Universities and Pricing on Higher Education Markets
Markets and prices in higher education. When can we speak of markets, and when markets exist, how are prices set
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