288 research outputs found
Carbon Capture; Transport and Storage in Europe: A Problematic Energy Bridge to Nowhere?
This paper is a follow up of the SECURE-project, financed by the European Commission to study âSecurity of Energy Considering its Uncertainties, Risks and Economic Implicationsâ. It addresses the perspectives of, and the obstacles to a CCTS-roll out, as stipulated in some of the scenarios. Our main hypothesis is that given the substantial technical and institutional uncertainties, the lack of a clear political commitment, and the available alternatives of low-carbon technologies, CCTS is unlikely to play an important role in the future energy mix; it is even less likely to be an âenergy bridgeâ into a low-carbon energy futureCarbon Capture, Transport, Storage
Mathematical modeling, simulation, and optimization of loading schemes for isometric resistance training
In this thesis, we present a novel mathematical model-based approach to optimize loading schemes of isometric resistance training (RT) sessions for different training goals. To this end, we develop a nonlinear ordinary differential equation model of the time course of maximum voluntary isometric (MVIC) force under external isometric loading. To validate the model, we set up multi-experiment parameter estimation problems using a comprehensive dataset from the literature. We solve these problems numerically via direct multiple shooting and the generalized Gauss-Newton method. Moreover, we use the proposed model to examine hypotheses about fatigue and recovery of MVIC force. Then, we mathematically formulate key performance indicators and optimality criteria for loading schemes of isometric RT sessions identified in sports science and incorporate these into multi-stage optimal control problems. We solve these problems numerically via direct multiple shooting and structure-exploiting sequential quadratic programming. We discuss the results from a numerical and sports scientific point of view. Based on the proposed model, we additionally formulate the estimation of critical torque as a nonlinear program. This allows us to reduce the experimental effort compared to conventional testing when estimating these quantities. Furthermore, we formulate multi-stage optimum experimental design problems to reduce the statistical uncertainty of the parameter estimates when calibrating the model. We solve these problems numerically via direct single shooting and sequential quadratic programming. We discuss the solutions from a numerical and physiological point of view. For our approach, a small amount of data obtained in a single testing session is sufficient. Our approach can be extended to more elaborate physiological models and other forms of resistance training once suitable models become available
CO2 Highways for Europe: Modelling a Carbon Capture, Transport and Storage Infrastructure for Europe. CEPS Working Document No. 340/November 2010
This paper presents a mixed integer, multi-period, cost-minimising model for a carbon capture, transport and storage (CCTS) network in Europe. The model incorporates endogenous decisions about carbon capture, pipeline and storage investments. The capture, flow and injection quantities are based on given costs, certificate prices, storage capacities and point source emissions. The results indicate that CCTS can theoretically contribute to the decarbonisation of Europeâs energy and industrial sectors. This requires a CO2 certificate price rising to âŹ55 per tCO2 in 2050, and sufficient CO2 storage capacity available for both on- and offshore sites. Yet CCTS deployment is highest in CO2-intensive industries where emissions cannot be avoided by fuel switching or alternative production processes. In all scenarios, the importance of the industrial sector as a first-mover to induce the deployment of CCTS is highlighted. By contrast, a decrease in available storage capacity or a more moderate increase in CO2 prices will significantly reduce the role of CCTS as a CO2 mitigation technology, especially in the energy sector. Furthermore, continued public resistance to onshore CO2 storage can only be overcome by constructing expensive offshore storage. Under this restriction, reaching the same levels of CCTS penetration would require a doubling of CO2 certificate prices
CO2 Highways for Europe: Modeling a Carbon Capture, Transport and Storage Infrastructure for Europe
We present a mixed integer, multi-period, cost-minimizing carbon capture, transport and storage (CCTS) network model for Europe. The model incorporates endogenous decisions about carbon capture, pipeline and storage investments; capture, flow and injection quantities based on given costs, certificate prices, storage capacities and point source emissions.The results indicate that CCTS can theoretically contribute to the decarbonization of Europe's energy and industry sectors. This requires a CO2 certificate price rising to 55 EUR in 2050, and sufficient CO2 storage capacity available for both on and offshore sites. However, CCTS deployment is highest in CO2-intensive industries where emissions cannot be avoided byfuel switching or alternative production processes. In all scenarios, the importance of the industrial sector as a first mover to induce the deployment of CCTS is highlighted. By contrast, a decrease of available storage capacity or a more moderate increase in CO2 prices will significantly reduce the role of CCTS as a CO2 mitigation technology, especially in the energy sector. Continued public resistance to onshore CO2 storage can only be overcome by constructing expensive offshore storage. Under this restriction, to reach the same levels of CCTS penetration will require doubling of CO2 certificate prices.carbon capture and storage, pipeline, infrastructure, optimization
Hohe Unsicherheiten bei der CO2-Abscheidung: eine EnergiebrĂŒcke ins Nichts?
Am 14. Juli 2010 brachte die Bundesregierung zum zweiten Mal einen Gesetzesentwurf zur CO2-Abscheide-, Transport- und Speichertechnologie (Carbon Capture, Transport, and Storage, CCTS) in das parlamentarische Verfahren ein. Der erste VorstoĂ war unter der GroĂen Koalition im Jahr 2009 am Widerstand der unionsgefĂŒhrten LĂ€nder gescheitert. Der nun vorliegende Entwurf bleibt weit hinter den notwendigen MaĂnahmen zurĂŒck, die eine groĂtechnische Erprobung der gesamten CCTS-Prozesskette ermöglichen wĂŒrde. Er schafft somit keine verlĂ€ssliche Grundlage fĂŒr die kommerzielle Entwicklung und Verbreitung dieser Technologie in Deutschland. Ohnehin haben sich die Aussichten, dass die CCTS-Technologie mittelfristig ein wichtiger Pfeiler der CO2-Vermeidungsstrategie der deutschen Energiewirtschaft sein wird, in der jĂŒngeren Vergangenheit stark eingetrĂŒbt. GrĂŒnde hierfĂŒr sind unter anderen Schwierigkeiten bei der technischen Umsetzung der CO2-Abscheidung, ungelöste regulatorische Fragen des Transports, eine deutliche Reduzierung der zu erwartenden Speicherpotentiale sowie die starke Ablehnung der gesamten Prozesskette durch die jeweils betroffene Bevölkerung und einige Landespolitiker. So bleibt der Einsatz von CCTS in der zukĂŒnftigen Energieversorgung unter den heutigen Bedingungen in Deutschland und Europa eher fraglich.CCTS
An LLVM Instrumentation Plug-in for Score-P
Reducing application runtime, scaling parallel applications to higher numbers
of processes/threads, and porting applications to new hardware architectures
are tasks necessary in the software development process. Therefore, developers
have to investigate and understand application runtime behavior. Tools such as
monitoring infrastructures that capture performance relevant data during
application execution assist in this task. The measured data forms the basis
for identifying bottlenecks and optimizing the code. Monitoring infrastructures
need mechanisms to record application activities in order to conduct
measurements. Automatic instrumentation of the source code is the preferred
method in most application scenarios. We introduce a plug-in for the LLVM
infrastructure that enables automatic source code instrumentation at
compile-time. In contrast to available instrumentation mechanisms in
LLVM/Clang, our plug-in can selectively include/exclude individual application
functions. This enables developers to fine-tune the measurement to the required
level of detail while avoiding large runtime overheads due to excessive
instrumentation.Comment: 8 page
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