363 research outputs found

    STOCHSIMGPU Parallel stochastic simulation for the Systems\ud Biology Toolbox 2 for MATLAB

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    Motivation: The importance of stochasticity in biological systems is becoming increasingly recognised and the computational cost of biologically realistic stochastic simulations urgently requires development of efficient software. We present a new software tool STOCHSIMGPU which exploits graphics processing units (GPUs)for parallel stochastic simulations of biological/chemical reaction systems and show that significant gains in efficiency can be made. It is integrated into MATLAB and works with the Systems Biology Toolbox 2 (SBTOOLBOX2) for MATLAB.\ud \ud Results: The GPU-based parallel implementation of the Gillespie stochastic simulation algorithm (SSA), the logarithmic direct method (LDM), and the next reaction method (NRM) is approximately 85 times faster than the sequential implementation of the NRM on a central processing unit (CPU). Using our software does not require any changes to the user’s models, since it acts as a direct replacement of the stochastic simulation software of the SBTOOLBOX2

    Biodegradable and compostable alternatives to conventional plastics

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    This article is available open access through the publisher’s website at the link below. Copyright @ 2009 The Royal Society.Packaging waste forms a significant part of municipal solid waste and has caused increasing environmental concerns, resulting in a strengthening of various regulations aimed at reducing the amounts generated. Among other materials, a wide range of oil-based polymers is currently used in packaging applications. These are virtually all non-biodegradable, and some are difficult to recycle or reuse due to being complex composites having varying levels of contamination. Recently, significant progress has been made in the development of biodegradable plastics, largely from renewable natural resources, to produce biodegradable materials with similar functionality to that of oil-based polymers. The expansion in these bio-based materials has several potential benefits for greenhouse gas balances and other environmental impacts over whole life cycles and in the use of renewable, rather than finite resources. It is intended that use of biodegradable materials will contribute to sustainability and reduction in the environmental impact associated with disposal of oil-based polymers. The diversity of biodegradable materials and their varying properties makes it difficult to make simple, generic assessments such as biodegradable products are all ‘good’ or petrochemical-based products are all ‘bad’. This paper discusses the potential impacts of biodegradable packaging materials and their waste management, particularly via composting. It presents the key issues that inform judgements of the benefits these materials have in relation to conventional, petrochemical-based counterparts. Specific examples are given from new research on biodegradability in simulated ‘home’ composting systems. It is the view of the authors that biodegradable packaging materials are most suitable for single-use disposable applications where the post-consumer waste can be locally composted.EPSR

    Longitudinal Beam Stabilization at FAIR by Means of a Derivative Estimation

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    During acceleration in SIS18/SIS100 at GSI/FAIR longitudinal beam-oscillations are expected to occur. To reduce emittance blow-up, dedicated LLRF beam feedback systems are planned. To date longitudinal beam oscillations have been damped in machine experiments with a finite-impulse-response (FIR) filter controller with 3 filter taps. An alternative approach implementing the FIR filter as a derivative estimator controller is simulated and tested. This approach shares the same controller topology and can therefore be easily integrated in the system. It exploits the fact that the sampling rate of the feedback hardware is considerably higher than the frequency of the beam oscillations. It is therefore capable of damping oscillations without overshoot within one oscillation period

    Interactive impacts of meteorological and hydrological conditions on the physical and biogeochemical structure of a coastal system

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    The German Bight was exposed to record high riverine discharges in June 2013, as a result of flooding of the Elbe and Weser rivers. Several anomalous observations suggested that the hydrodynamical and biogeochemical states of the system were impacted by this event. In this study, we developed a biogeochemical model and coupled it with a previously introduced high-resolution hydrodynamical model of the southern North Sea in order to better characterize these impacts and gain insight into the underlying processes. Performance of the model was assessed using an extensive set of in situ measurements for the period 2011–2014. We first improved the realism of the hydrodynamic model with regard to the representation of cross-shore gradients, mainly through inclusion of flow-dependent horizontal mixing. Among other characteristic features of the system, the coupled model system can reproduce the low salinities, high nutrient concentrations and low oxygen concentrations in the bottom layers observed within the German Bight following the flood event. Through a scenario analysis, we examined the sensitivity of the patterns observed during July 2013 to the hydrological and meteorological forcing in isolation. Within the region of freshwater influence (ROFI) of the Elbe–Weser rivers, the flood event clearly dominated the changes in salinity and nutrient concentrations, as expected. However, our findings point to the relevance of the peculiarities in the meteorological conditions in 2013 as well: a combination of low wind speeds, warm air temperatures and cold bottom-water temperatures resulted in a strong thermal stratification in the outer regions and limited vertical nutrient transport to the surface layers. Within the central region, the thermal and haline dynamics interactively resulted in an intense density stratification. This intense stratification, in turn, led to enhanced primary production within the central region enriched by nutrients due to the flood but led to reduction within the nutrient-limited outer region, and it caused a widespread oxygen depletion in bottom waters. Our results further point to the enhancement of the current velocities at the surface as a result of haline stratification and to intensification of the thermohaline estuarine-like circulation in the Wadden Sea, both driven by the flood event

    Modeling and Simulation of Broadband RF Cavities in PSpice

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    Barrier bucket systems are planned for the SIS100 Synchrotron (part of the future accelerator facility FAIR) and the ESR storage ring to facilitate several longitudinal beam manipulations [9] [15]. In order to achieve a single-sine gap signal of the desired amplitude and quality, effects in the linear and nonlinear region of the RF systems have to be investigated and included in the design of the overall system. Therefore, the cavities and the amplifier stages are to be modeled in PSpice. In this contribution, a cavity model will be presented. In a first step, a model for the magnetic alloy (MA) ring cores, which highly account for the properties of the cavity, has been found based on measurement data. In a second step, the future setup of the cavity is systematically created using the MA ring core models. The model of the cavity allows simulations in frequency domain as well as time domain. The results show good agreement with former measurements

    Investigation and Assessment of Resource Consumption of Process Chains

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    AbstractMany different technologies and processes have been established in production within the last decades. These technologies have to be integrated into sophisticated process chains to achieve today's requirements of high performance products. For most of these products the costs can be determined or at least estimated accurately. However, resource intensive and thus cost intensive processes and their potential within the process chains are often neither identified nor quantified. For identifying, measuring and subsequently assessing the need of resources, like energy or material and their monetary as well as environmental impact, four different process chains of high industrial relevance have been chosen and investigated with regards to their resource consumption. These process chains are used for manufacturing turbine blades made of Inconel and titanium aluminide as well as for comparisons of a conventional and an innovative process chain to manufacture an insert for an injection mold. By measuring and assessing their resource consumption the most resource intensive and thus influential processes have been identified and their potential for resource reduction has been evaluated. Due to the change of single processes to reduce resource consumption and thus the conditions for subsequent processes, the requirements might change and lead to adaptions within the entire process chain. For the assessment of the process chains and the changes within the processes themselves, a scenario based assessment has been modelled. This results in an economic and ecologic evaluation of these process chains and enables a comparison of these to choose the most meaningful process chain

    A MULTIDISCIPLINARY APPROACH TO INJURY RISK MANAGEMENT IN PROFESSIONAL RUGBY UNION

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    PURPOSE: Injuries result from complex interactions between a variety of internal and external risk factors. Due to the complex-systems nature of injuries it is not possible to place responsibility for injury risk management solely within a single domain of professional practice. Instead, an interdisciplinary collaboration between technical/tactical coaches, strength and conditioning coaches, team doctors, physical therapists and sport scientists is more likely to have a meaningful impact on injury risk. The purpose of this study is to describe the development and application of a multidisciplinary model for reducing team injury risk in professional rugby union. METHODS: Epidemiological injury data was collected from a team of professional rugby union players over the course of 5 consecutive season. Following each season, a multidisciplinary audit was conducted to identify areas where risk mitigation strategies could be applied within the team environment. These strategies took the form of technical/tactical, strength and conditioning, player monitoring medical and therapeutic interventions that were all applied concurrently (Figure 1). The effectiveness of this program was assessed against the total team injury burden per season, as well as the burden from contact and non-contact injuries. 95% confidence intervals were calculated using standard equations, and values were considered significantly different if the 95% confidence intervals did not overlap. RESULTS: Overall team injury burden decreased significantly (9, 95%CI 5 to 13 %) from 2012 to 2016. Non-contact injuries were also significantly reduced (39, 95%CI 34 to 44 %), while contact injury burden was increased to a lesser degree (21, 95%CI 15 to 27 %) during the same period. Specific examples of multidisciplinary interventions are provided. CONCLUSIONS: The range of skills required to effectively manage injury risk in professional collision sport crosses disciplinary boundaries. The evidence presented here points to the effectiveness of a multidisciplinary approach to reducing injury risk. PRACTICAL APPLICATION: The multidisciplinary model of injury risk management will encourage increased collaboration across professional disciplines within sport. This model will likely be applicable across a range of team and individual sports
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