Search results for "Simulations"
showing 10 items of 288 documents
Sodium bis(2-ethylhexyl)sulfosuccinate self-aggregation in vacuo: molecular dynamics simulation.
2010
Molecular dynamics (MD) simulations were conducted for systems in vacuo consisting of n AOT(-) anions (bis(2-ethylhexyl)sulfosuccinate ions) and n+/- 1 or n Na(+) ions up to n = 20. For n = 15, positively charged systems with Li(+), K(+), and Cs(+) cations were also considered. All systems were observed to form reverse micelle-like aggregates whose centre is occupied by cations and polar heads in a very compact solid-like way, while globally the aggregate has the form of an elongated and rather flat ellipsoid. Various types of statistical analyses were carried out on the systems to enlighten structural and dynamical properties including gyration radius, atomic pair correlation functions, at…
Estimation of statistical time-to-cure in cancer patients
2019
Three million people are living in France with a personal past of cancer and undergo difficulties in accessing loans and insurance. Since 2016, the French law « modernisation de notre système de santé » set the "right to be forgotten" (time beyond which insurance applicants with a past of cancer will no longer have to declare it) at 10 years after the end of treatment. From a statistical point of view, this delay can be considered as the time from which mortality due to cancer (excess mortality) disappears. After this time, the net survival curves reach a plateau corresponding to the proportion of cured patients. The verification of this hypothesis is based on two criteria: a negligible exc…
A rational expectations model for simulation and policy evaluation of the Spanish economy
2010
This paper presents the model used for simulation purposes within the Spanish Ministry of Economic Affairs and Finance. REMS (a Rational Expectations Model for the Spanish economy) is a small open economy dynamic general equilibrium model in the vein of the New-Neoclassical-Keynesian synthesis models, with a strongly micro-founded system of equations. In the long run REMS behaves in accordance with the neoclassical growth model. In the short run, it incorporates nominal, real and financial frictions. Real frictions include adjustment costs in consumption (via habits in consumption and rule-of-thumb households) and investment into physical capital. Due to financial frictions, there is no per…
Monte Carlo simulation of the energy released by neutrons on organic compounds for EPR dosimetry
2022
In this work we report the analyses of the energy released per unit mass in organic compounds used for EPR dosimetry exposed to neutron beams in order to predict the increase in dose achievable by addition of gadolinium (Gd) inside the pellets. In particular, Monte Carlo (MC) simulations were carried out for alanine, ammonium tartrate and phenolic compounds irradiated with neutron beams with different energy spectra at various depths inside a water phantom. The addition of gadolinium increases sensitivity of these dosimeters to neutrons thanks to the high gadolinium cross section for neutron capture and to the large number of secondary particles (mainly Auger and internal conversion electro…
Ettringite surface chemistry: Interplay of electrostatic and ion specificity
2011
International audience; This paper presents a detailed experimental study combined with Monte Carlo (MC) simulations within the primitive model of the physical chemistry at the ettringite-water interface over a wide range of pH and bulk conditions for which ettringite exists thanks to its solubility in aqueous solutions. Ettringite, which is an important phase in hydrated cement-based systems, bears a permanent and positive structural charge. In contrast with previous studies, electrokinetic measurements together with the careful chemical analysis of the equilibrium solutions of the dispersions have brought strong support to designate sulfate as being the ion determining the potential. Simu…
Free Energy, Enthalpy and Entropy from Implicit Solvent End-Point Simulations
2018
Free energy is the key quantity to describe the thermodynamics of biological systems. In this perspective we consider the calculation of free energy, enthalpy and entropy from end-point molecular dynamics simulations. Since the enthalpy may be calculated as the ensemble average over equilibrated simulation snapshots the difficulties related to free energy calculation are ultimately related to the calculation of the entropy of the system and in particular of the solvent entropy. In the last two decades implicit solvent models have been used to circumvent the problem and to take into account solvent entropy implicitly in the solvation terms. More recently outstanding advancement in both impli…
Implementation of walk-through audits for designing energy management system: A first step towards an efficient campus
2020
Abstract The purpose of this study is to design a concept of energy management control system (EMCS) at the UNSADA campus, Jakarta, Indonesia by utilizing the results of the previous walkthrough audit. EMCS is an important first step by involving all parties on campus to be concerned the sustainable energy savings. The energy efficiency program utilizes the campus as an energy laboratory to identify, recommend, implement and evaluate the energy consumption, so that the expected energy efficiency targeted by the top managements can be achieved. This program is motivated by several reasons, such as; to support government policies in reducing dependence on fossil energy by implementing energy …
Energy measurements at Skarpnes zero energy homes in Southern Norway: Do the loads match up with the on-site energy production?
2017
Five houses are designed as zero-energy homes in Skarpnes, Norway. The energy goal is to achieve net zero-energy balance on an annual basis. The houses have heat pumps and solar cells (PV). Energy use and delivered energy have been monitored from June 2015. Variations between calculations and measurements are explained by technical and non-technical reasons. For the first year, higher than expected energy loads result in a solar energy cover factor of 65–87% of delivered electricity. The PV generation performs satisfactorily, hence, it may be possible to achieve energy goals during later years provided technical adjustments or behavioral changes. Acknowledgements. This report has been writt…
Modular, customisable, accomodation-friendly antenna system for satellite avionics: Development, prototyping and validation
2014
In the frame of ESA program AO/1- 6737/11/NL/MH, an innovative X-band antenna system for satellite avionics has been studied, demonstrated and validated at Proof of Concept Model level. The innovative contribution of such an antenna system relies on modularity, customizability and accommodation friendliness. The antenna concept is based on a Plug and Play architecture, where the basic module is a 2.7 cm-cube with a mass of 53 gr, which can be clustered in array configuration. A catalogue of predefined and ready-to-use clusters could be developed with the possibility of adapting the antenna systems to various platform types by tuning just a few control parameters. Different levels of customi…
Using FEM simulation to predict structural performances of a sailing dinghy
2017
The use of finite element method (FEM) tools is proposed to investigate the structural response of an eco-sustainable sailing yacht to different loading conditions, typical of those acting during regattas. The boat is, in particular, a 4.60 m dinghy with the hull and the deck made of an hybrid flaxâcork sandwich and internal reinforcements made of marine plywood. A preliminary activity has consisted in the refitting of an existing model in order to reduce the hull weight and to improve performances during manoeuvrings. These tasks have been interactively simulated in the virtual environment of the boat CAD model, where longitudinal and transversal reinforcements were enlightened and the m…