1,881 research outputs found
Techno-economic analysis of residential thermal flexibility for demand side management
The continuing rise in solar and wind production leads to an increasing demand of flexibility to stabilize the electricity grid. Furthermore, we can assume a gradual but intensive rise in the use of electrical heatpumps for household spatial heating, for different reasons. Therefore, this paper investigates the feasibility and viability of entering the flexibility market by aggregating residential thermal loads. For this research, a dataset of 200 dwellings in the Netherlands, equipped with a heatpump and smart metering infrastructure, is analysed. By means of a greybox modeling approach, a thermal model and control framework have been set up for every house, in order to identify the load shift potential and the accompanying cost of providing flexibility for the houses. We find that thermal flexibility is asymmetric: downwards flexibility is, apart from much more dependent on outdoor temperature than upwards flexibility, strictly lower than upwards flexibility. The cost for downwards flexibility is strictly negative in terms of the prosumer. Concerning upwards flexibility, the cost is most of the time positive. Moreover, it can be concluded that there is a potentially viable business case for the flexibility aggregator
Transcriptome profiling reveals significant changes in the gastric muscularis externa with obesity that partially overlap those that occur with idiopathic gastroparesis
BACKGROUND:
Gastric emptying is impaired in patients with gastroparesis whereas it is either unchanged or accelerated in obese individuals. The goal of the current study was to identify changes in gene expression in the stomach muscularis that may be contributing to altered gastric motility in idiopathic gastroparesis and obesity.
METHODS:
Quantitative real time RT-PCR and whole transcriptome sequencing were used to compare the transcriptomes of lean individuals, obese individuals and either lean or obese individuals with idiopathic gastroparesis.
RESULTS:
Obesity leads to an increase in mRNAs associated with muscle contractility whereas idiopathic gastroparesis leads to a decrease in mRNAs associated with PDGF BB signaling. Both obesity and idiopathic gastroparesis were also associated with similar alterations in pathways associated with inflammation.
CONCLUSIONS:
Our findings show that obesity and idiopathic gastroparesis result in overlapping but distinct changes in the gastric muscularis transcriptome. Increased expression of mRNAs encoding smooth muscle contractile proteins may be contributing to the increased gastric motility observed in obese subjects, whereas decreased PDGF BB signaling may be contributing to the impaired motility seen in subjects with idiopathic gastroparesis
Clinical implications of the anisotropic analytical algorithm for IMRT treatment planning and verification
PURPOSE:
To determine the implications of the use of the Anisotropic Analytical Algorithm(AAA) for the production and dosimetric verification of IMRT plans for treatments of the
prostate, parotid, nasopharynx and lung.
METHODS:
72 IMRT treatment plans produced using the Pencil Beam Convolution (PBC)algorithm were recalculated using the AAA and the dose distributions compared. 24 of the
plans were delivered to inhomogeneous phantoms and verification measurements made using a pinpoint ionisation chamber. The agreement between the AAA and measurement
was determined.
RESULTS:
Small differences were seen in the prostate plans, with the AAA predicting slightly lower minimum PTV doses. In the parotid plans, there were small increases in the lens and
contralateral parotid doses while the nasopharyngeal plans revealed a reduction in the volume of the PTV covered by the 95% isodose (the V95%) when the AAA was used. Large
changes were seen in the lung plans, the AAA predicting reductions in the minimum PTV dose and large reductions in the V95%. The AAA also predicted small increases in the mean
dose to the normal lung and the V20. In the verification measurements, all AAA calculations were within 3% or 3.5mm distance to agreement of the measured doses.
Conclusions: The AAA should be used in preference to the PBC algorithm for treatments involving low density tissue but this may necessitate re-evaluation of plan acceptability
criteria. Improvements to the Multi-Resolution Dose Calculation algorithm used in the inverse planning are required to reduce the convergence error in the presence of lung tissue. There was excellent agreement between the AAA and verification measurements for all sites
A femtoscopic Correlation Analysis Tool using the Schr\"odinger equation (CATS)
We present a new analysis framework called "Correlation Analysis Tool using
the Schr\"odinger equation" (CATS) which computes the two-particle femtoscopy
correlation function , with being the relative momentum for the
particle pair. Any local interaction potential and emission source function can
be used as an input and the wave function is evaluated exactly. In this paper
we present a study on the sensitivity of to the interaction potential
for different particle pairs: p-p, p-, -p,
-p, p- and -.
For the p-p Argonne and Reid Soft-Core potentials have been tested.
For the other pair systems we present results based on strong potentials
obtained from effective Lagrangians such as EFT for p-,
J\"ulich models for -N and Nijmegen models for
-. For the p- pairs we
employ the latest lattice results from the HAL QCD collaboration. Our detailed
study of different interacting particle pairs as a function of the source size
and different potentials shows that femtoscopic measurements can be exploited
in order to constrain the final state interactions among hadrons. In
particular, small collision systems of the order of 1~fm, as produced in pp
collisions at the LHC, seem to provide a suitable environment for quantitative
studies of this kind.Comment: 16 pages, 13 figures, submitted to EPJ
DELAYED KIDNEY TRANSPLANTATION AFTER 83 HOURS OF COLD ISCHEMIA TIME IN COMBINED LIVER-KIDNEY TRANSPLANT
First-principles equation of state of CHON resin for inertial confinement fusion applications
A wide-range (0 to 1044.0 g/cm3 and 0 to 109 K) equation-of-state (EOS) table for a CH1.72O0.37N0.086 quaternary compound has been constructed based on density-functional theory (DFT) molecular-dynamics (MD) calculations using a combination of Kohn-Sham DFT MD, orbital-free DFT MD, and numerical extrapolation. The first-principles EOS data are compared with predictions of simple models, including the fully ionized ideal gas and the Fermi-degenerate electron gas models, to chart their temperature-density conditions of applicability. The shock Hugoniot, thermodynamic properties, and bulk sound velocities are predicted based on the EOS table and compared to those of C-H compounds. The Hugoniot results show the maximum compression ratio of the C-H-O-N resin is larger than that of CH polystyrene due to the existence of oxygen and nitrogen; while the other properties are similar between CHON and CH. Radiation hydrodynamic simulations have been performed using the table for inertial confinement fusion targets with a CHON ablator and compared with a similar design with CH. The simulations show CHON outperforms CH as the ablator for laser-direct-drive target designs
Transition of EMRIs through resonance: Corrections to higher order in the on-resonance flux modification
Extreme mass ratio in-spirals (EMRIs) are candidate events for gravitational
wave detection in the millihertz range (by detectors like LISA and eLISA).
These events involve a stellar-mass black hole, or a similar compact object,
descending in the gravitational field of a supermassive black hole, eventually
merging with it. Properties of the in-spiralling trajectory away from resonance
are well known and have been studied extensively, however little is known about
the behaviour of these binary systems at resonance, when the radial and lateral
frequencies of the orbit become commensurate. We describe the two existing
models, the instantaneous frequency approach used by Gair, Bender, and Yunes,
and the standard two timescales approach implemented by Flanagan and Hinderer.
In both cases, the exact treatment depends on the modelling of the
gravitational self-force, which is currently not available. We extend the
results in Gair, Bender and Yunes to higher order in the on-resonance flux
modification, and argue that the instantaneous frequency approach is also a
valid treatment of the resonance problem. The non-linear differential equations
which arise in treating resonances are interesting from a mathematical view
point. We present our algorithm for perturbative solutions and the results to
third order in the infinitesimal parameter, and discuss the scope of this
approach
Game theory framework for MAC parameter optimization in energy-delay constrained sensor networks
Optimizing energy consumption and end-to-end (e2e) packet delay in energy-constrained, delay-sensitive wireless sensor networks is a conflicting multiobjective optimization problem. We investigate the problem from a game theory perspective, where the two optimization objectives are considered as game players. The cost model of each player is mapped through a generalized optimization framework onto protocol-specific MAC parameters. From the optimization framework, a game is first defined by the Nash bargaining solution (NBS) to assure energy consumption and e2e delay balancing. Secondy, the Kalai-Smorodinsky bargaining solution (KSBS) is used to find an equal proportion of gain between players. Both methods offer a bargaining solution to the duty-cycle MAC protocol under different axioms. As a result, given the two performance requirements (i.e., the maximum latency tolerated by the application and the initial energy budget of nodes), the proposed framework allows to set tunable system parameters to reach a fair equilibrium point that dually minimizes the system latency and energy consumption. For illustration, this formulation is applied to six state-of-the-art wireless sensor network (WSN) MAC protocols: B-MAC, X-MAC, RI-MAC, SMAC, DMAC, and LMAC. The article shows the effectiveness and scalability of such a framework in optimizing protocol parameters that achieve a fair energy-delay performance trade-off under the application requirements
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