615 research outputs found
Levenscyclusanalyse groencompost: grootschalig en zelf composteren.
Door PPO-AGV is in 2009 een studie uitgevoerd om in een levenscyclusanalyse (LCA) de bereiding van groencompost op het agrarisch bedrijf te vergelijken met de bereiding van groencompost op regioschaal door gespecialiseerde composteerbedrijven.
Bereiding van groencompost op het agrarisch bedrijf heeft het voordeel dat flink bespaard kan worden op energieverbruik en vrachtvervoer op de weg. Daar staat tegenover dat gespecialiseerde groencomposteerders gebruik kunnen maken van schaalgroottevoordelen, betere sturing kunnen geven aan gewenste composteercondities en dat zij gebruik kunnen maken van groenafval van natuurgebieden. De studie bouwt voort op de studie die in 2008 is uitgevoerd, waarbij o.a. een LCA voor GFT-compost is opgesteld. Voor zover dat mogelijk is, zijn de kengetallen voor de bereiding van groencompost vergeleken met die van GFTcompost
A Virtual Conversational Agent for Teens with Autism: Experimental Results and Design Lessons
We present the design of an online social skills development interface for
teenagers with autism spectrum disorder (ASD). The interface is intended to
enable private conversation practice anywhere, anytime using a web-browser.
Users converse informally with a virtual agent, receiving feedback on nonverbal
cues in real-time, and summary feedback. The prototype was developed in
consultation with an expert UX designer, two psychologists, and a pediatrician.
Using the data from 47 individuals, feedback and dialogue generation were
automated using a hidden Markov model and a schema-driven dialogue manager
capable of handling multi-topic conversations. We conducted a study with nine
high-functioning ASD teenagers. Through a thematic analysis of post-experiment
interviews, identified several key design considerations, notably: 1) Users
should be fully briefed at the outset about the purpose and limitations of the
system, to avoid unrealistic expectations. 2) An interface should incorporate
positive acknowledgment of behavior change. 3) Realistic appearance of a
virtual agent and responsiveness are important in engaging users. 4)
Conversation personalization, for instance in prompting laconic users for more
input and reciprocal questions, would help the teenagers engage for longer
terms and increase the system's utility
Measurement-induced focusing and the magnitude of loss aversion:The difference between comparing gains to losses and losses to gains
Research has identified loss aversion as a strong and robust phenomenon, but has also revealed some moderators affecting the magnitude of its effect on decision making. In the current article, we draw attention to the fact that even the measurement of loss aversion itself may affect its magnitude by inducing a focus on either losses or gains. In three studies, we provide empirical evidence for such a measurement-induced focus. In all studies we used coin-toss gambles---in which there is a 50/50 chance to win or to lose---to assess gain/loss ratios as a measure of loss aversion. Participants either filled out the loss side or the gain side of this gain/loss ratio. The studies consistently showed that---using within- and between-subject designs and anticipated and real coin-toss gambles---the strength of loss aversion depended on the measurement format (fill-in-the-loss versus fill-in-the-gain); filling in the loss side increased loss aversion. Moreover, loss aversion was more affected by the stakes of the gamble in the fill-in-the-loss format than in the fill-in-the-gain format
Subdominant modes and optimization trends of DIII-D reverse magnetic shear configurations
Alfven Eigenmodes and magneto-hydrodynamic modes are destabilized in DIII-D
reverse magnetic shear configurations and may limit the performance of the
device. We use the reduced MHD equations in a full 3D system, coupled with
equations of density and parallel velocity moments for the energetic particles
(with gyro-fluid closures) as well as the geodesic acoustic wave dynamics. The
aim of the study consists in finding ways to avoid or minimize MHD and AE
activity for different magnetic field configurations and neutral beam injection
operational regimes. The simulations show at the beginning of the discharge,
before the reverse shear region is formed, a plasma that is AE unstable and
marginally MHD stable. As soon as the reverse shear region appears, ideal MHD
modes are destabilized with a larger growth rate than the AEs. Both MHD modes
and AEs coexist during the discharge, although the MHD modes are more unstable
as the reverse shear region deepens. The simulations indicate the
destabilization of Beta induced AE, Toroidal AE, Elliptical AE and Reverse
Shear AE at different phases of the discharges. A further analysis of the NBI
operational regime indicates that the AE stability can be improved if the NBI
injection is off axis, because on-axis injection leads to AEs with larger
growth rate and frequency. In addition, decreasing the beam energy or
increasing the NBI relative density leads to AEs with larger growth rate and
frequency, so an NBI operation in the weakly resonant regime requires higher
beam energies than in the experiment. The MHD linear stability can be also
improved if the reverse shear region and the q profile near the magnetic axis
are in between the rational surfaces q=2 and q=1, particularly if there is a
region in the core with negative shear, avoiding a flat q profile near the
magnetic axis
Subdominant modes and optimization trends of DIII-D reverse magnetic shear configurations
Alfvén Eigenmodes (AE) and magneto-hydrodynamic (MHD) modes are destabilized in DIII-D reverse magnetic shear configurations and may limit the performance of the device. We use the reduced MHD equations in a full 3D system, coupled with equations of density and parallel velocity moments for the energetic particles (with gyro-fluid closures) as well as the geodesic acoustic wave dynamics, to study the properties of instabilities observed in DIII-D reverse magnetic shear discharges. The aim of the study consists in finding ways to avoid or minimize MHD and AE activity for different magnetic field configurations and neutral beam injection (NBI) operational regimes. The simulations show at the beginning of the discharge, before the reverse shear region is formed, a plasma that is AE unstable and marginally MHD stable. As soon as the reverse shear region appears, ideal MHD modes are destabilized with a larger growth rate than the AEs. Both MHD modes and AEs coexist during the discharge, although the MHD modes are more unstable as the reverse shear region deepens. The simulations indicate the destabilization of Beta induced AE (BAE), Toroidal AE (TAE), elliptical AE (EAE) and reverse shear AE (RSAE) at different phases of the discharges, showing a reasonable agreement between the frequency range of the dominant modes in the simulations and the diagnostic measurements (...)This material based on work is supported both by
the U.S. Department of Energy, Office of Science, under
Contract DE-AC05-00OR22725 with UT-Battelle,
LLC and U.S. Department of Energy, Oce of Science,
Oce of Fusion Energy Sciences, using the DIII-D National
Fusion Facility, a DOE Oce of Science user facility, under Award No. DE-FC02-04ER54698. This research was sponsored in part by the Ministerio of EconomĂa y Competitividad of Spain under project no.ENE2015-68265-P. DIII-D data shown in this paper
can be obtained in digital format by following the links
at https://fusion.gat.com/global/D3D DMP.Publicad
Barriers for prosumers’ open business models: a resource-based view on assets and data-sharing in electricity markets
This article explores the barriers for open business models in support of sustainability in electricity markets. It puts forward privacy and data protection concerns about sharing prosumers’ physical assets as well as data due to to their critical role in decentralized modes of electricity/flexibility trading. In particular, it uses a multiple case study approach to identify actors’ resources, examine other interested actors in each resource, define their objectives, and consider privacy and data protection concerns of sharing prosumers’ physical assets and data. The findings yield new insights into sharing opportunities beyond electricity/flexibility trading. In doing so, our study contributes to theories of the firm by applying the resource-based view in a new context and to the business model literature by shedding light on barriers in applying open business models
Weer beĂŻnvloedt werking herbiciden
Gegevens in bijgaande tabellen: 1) Minimum em maximum temperatuur en relatieve luchtvochtigheid in de luchtlaag op 10 cm boven het grondoppervlak op de dag van toepassing van de middelen; 2) Gewicht per plant perzikkruid na bespuiting met vier doseringen Basagra
Nonlinear dynamics and transport driven by energetic particle instabilities using a gyro-Landau closure model
Energetic particle (EP) destabilized Alfvén eigenmode (AE) instabilities are simulated for a DIII-D experimental case with a pulsed neutral beam using a gyro-Landau moments model which introduces EP phase-mixing effects through closure relations. This provides a computationally efficient reduced model which is applied here in the nonlinear regime over timescales that would be difficult to address with more complete models. The long timescale nonlinear evolution and related collective transport losses are examined including the effects of zonal flow/current generation, nonlinear energy cascades, and EP profile flattening. The model predicts frequencies and mode structures that are consistent with experimental observations. These calculations address issues that have not been considered in previous modelling: The EP critical gradient profile evolution in the presence of zonal flows/currents, and the dynamical nature of the saturated state. A strong level of intermittency is present in the predicted instability-driven transport; this is connected to the zonal flow growth and decay cycles and nonlinear energy transfers. Simulation of intermittent AE-enhanced EP transport will be an important issue for the protection of plasma facing components in the next generation of fusion devices.This material is based upon work supported by the US Department
of Energy, Office of Science using the DIII-D National
Fusion Facility, a DOE Office of Science user facility, under
Awards DE-AC05-00OR22725, DE-FC02-04ER54698,
and the US DOE SciDAC ISEP Center. Support is also
acknowledged from project 2019-T1/AMB-13648 founded
by the Comunidad de Madrid and Comunidad de Madrid
(Spain)—multiannual agreement with UC3M Excelencia
para el Profesorado Universitario EPUC3M14 Fifth
regional research plan 2016-2020. This research used
resources of the National Energy Research Scientific Computing
Center (NERSC), a US Department of Energy Office
of Science User Facility located at Lawrence Berkeley
National Laboratory, operated under Contract No. DE-AC02-
05CH11231. We would like to thank Matt Beidler of Oak
Ridge National Laboratory for helpful suggestions on this
manuscript
Modulation of prompt fast-ion loss by applied n=2 fields in the DIII-D tokamak
Energy and pitch angle resolved measurements of escaping neutral beam ions (E approximate to 80 keV) have been made during DIII-D L-mode discharges with applied, slowly rotating, n = 2 magnetic perturbations. Data from separate scintillator detectors (FILDs) near and well below the plasma midplane show fast-ion losses correlated with the internal coil (I-coil) fields. The dominant fast-ion loss signals are observed to decay within one poloidal transit time after beam turn-off indicating they are primarily prompt loss orbits. Also, during application of the rotating I-coil fields, outboard midplane edge density and bremsstrahlung emission profiles exhibit a radial displacement of up to delta R approximate to 1 cm. Beam deposition and full orbit modeling of these losses using M3D-C1 calculations of the perturbed kinetic profiles and fields reproduce many features of the measured losses. In particular, the predicted phase of the modulated loss signal with respect to the I-coil currents is in close agreement with FILD measurements as is the relative amplitudes of the modulated losses for the co and counter-current beam used in the experiment. These simulations show modifications to the beam ion birth profile and subsequent prompt loss due to changes in the edge density; however, the dominant factor causing modulation of the losses to the fast-ion loss detectors is the perturbed magnetic field (delta B/B approximate to 10(-3) in the plasma). Calculations indicate total prompt loss to the DIII-D wall can increase with application of the n = 2 perturbation by up to 7% for co-current injected beams and 3% for counter-current injected beams depending on phase of the perturbation relative to the injected beam.US Department of Energy DE-FC02-04ER54698, SC-G903402, DEAC02- 09CH11466, DE-FG02-04ER54761, DE-FG02- 05ER5480
Fast-ion redistribution and loss due to edge perturbations in the ASDEX Upgrade, DIII-D and KSTAR tokamaks
The impact of edge localized modes (ELMs) and externally applied resonant and non-resonant magnetic perturbations
(MPs) on fast-ion confinement/transport have been investigated in the ASDEX Upgrade (AUG), DIII-D and KSTAR
tokamaks. Two phases with respect to the ELM cycle can be clearly distinguished in ELM-induced fast-ion losses.
Inter-ELM losses are characterized by a coherent modulation of the plasma density around the separatrix while
intra-ELM losses appear as well-defined bursts. In high collisionality plasmas with mitigated ELMs, externally
applied MPs have little effect on kinetic profiles, including fast-ions, while a strong impact on kinetic profiles is
observed in low-collisionality, low
q
95
plasmas with resonant and non-resonant MPs. In low-collisionality H-mode
plasmas, the large fast-ion filaments observed during ELMs are replaced by a loss of fast-ions with a broad-band
frequency and an amplitude of up to an order of magnitude higher than the neutral beam injection prompt loss signal
without MPs. A clear synergy in the overall fast-ion transport is observed between MPs and neoclassical tearing
modes. Measured fast-ion losses are typically on banana orbits that explore the entire pedestal/scrape-off layer. The
fast-ion response to externally applied MPs presented here may be of general interest for the community to better
understand the MP field penetration and overall plasma response.Ministerio de EconomĂa y Empresa ((RYC-2011-09152 y ENE2012-31087)Marie Curie (Grant PCIG11-GA-2012-321455)US Department of Energy (DE-FC02-04ER54698, SC-G903402, DE-FG02-04ER54761, DE-AC02-09CH11466 and DE-FG02- 08ER54984)NRF Korea contract 2009-0082012MEST under the KSTAR projec
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