Search results for "Simulation"

A quasi chemistry-transport model mode for EMAC

2010

Abstract. A quasi chemistry-transport model mode (QCTM) is presented for the numerical chemistry-climate simulation system ECHAM/MESSy Atmospheric Chemistry (EMAC). It allows for a quantification of chemical signals through suppression of any feedback between chemistry and dynamics. Noise would otherwise interfere too strongly. The signal is calculated from the difference of two QCTM simulations, a reference simulation and a sensitivity simulation. In order to avoid the feedbacks, the simulations adopt the following offline chemical fields: (a) offline mixing ratios of radiatively active substances enter the radiation scheme, (b) offline mixing ratios of nitric acid enter the scheme for re-…

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…

Dynamic thermal simulation of buildings: a case study to validate ESP-r software

2008

Energy aspects and environmental problems have a key role in the definition of building’s design, management and maintenance. The energy saving and the decrease of environmental impact throughout the life cycle assessment of buildings maintaining an high level of comfort are Key points for a modern and sustainable construction (total quality of the building). In fact, the building’s design has to be considered the result of a multi-objective problem. Furthermore the European Directive 2002/91/EC issues the sustainable themes on the energy performance of buildings [1], and include the energy certification of new buildings with effect from 2006

EXPOSURE OF Gd2O3-ALANINE AND Gd2O3-AMMONIUM TARTRATE ESR DOSIMETERS TO THERMAL NEUTRONS: EXPERIMENTS AND MONTE CARLO SIMULATIONS

2008

Pathway network inference from gene expression data

2014

[EN] Background: The development of high-throughput omics technologies enabled genome-wide measurements of the activity of cellular elements and provides the analytical resources for the progress of the Systems Biology discipline. Analysis and interpretation of gene expression data has evolved from the gene to the pathway and interaction level, i.e. from the detection of differentially expressed genes, to the establishment of gene interaction networks and the identification of enriched functional categories. Still, the understanding of biological systems requires a further level of analysis that addresses the characterization of the interaction between functional modules. Results: We presen…

Système distribué d'alerte de la qualité de l'eau pour la rivière Mudan basé sur l'EFDC et les SIG

2016

Simulation and Early Warning System (SEWS) is a powerful tool for river water quality monitoring. Mudan River, an important river in northeastern cold regions of China, can run out of China into Russia. Thus, the water quality of Mudan River is highly concerned not only locally andregionally but also internationally. Objective of this study is to establish an excellent SEWS of water quality so that the spatio-temporal distribution of water quality in both open-water and ice-covered periods can be accurately simulated and visualized to understand the spatial variation of pollutants along the river course. The dissertation is structured into 7 chapters, chapter 1 outlines the background of th…

Latent force models for earth observation time series prediction

2016

We introduce latent force models for Earth observation time series analysis. The model uses Gaussian processes and differential equations to combine data driven modelling with a physical model of the system. The LFM presented here performs multi-output structured regression, adapts to the signal characteristics, it can cope with missing data in the time series, and provides explicit latent functions that allow system analysis and evaluation. We successfully illustrate the performance in challenging scenarios of crop monitoring from space, providing time-resolved time series predictions.

Life cycle assessment of roads: Material and process related energy savings

2018

The need for climate change mitigation calls for significant actions to match the sustainable development goals and, in this context, road construction and management play a relevant role (cf. EU Green Public Procurement Criteria for Road Design, Construction and Maintenance and Environmental Product Declarations - EPD). In such a context, the role of the Life Cycle Assessment (LCA) methodology is broadly recognized as a tool to quantify sustainability of processes and systems. This study aims at calculating the life-cycle energy and carbon footprint of a typical Italian urban road, including materials production, transportation, construction, maintenance, and rehabilitation. The LCA approa…

Revisiting the role of top-down and bottom-up controls in stabilisation of nutrient-rich plankton communities

2019

Understanding the conditions for successful control of phytoplankton by zooplankton in eutrophic ecosystems is a highly important research area with a wide implementation of mathematical modelling. Theoretical models generally predict destabilisation of food webs in eutrophic environments with large-amplitude oscillations of population densities which would eventually result in species extinction. On the other hand, these theoretical predic- tions are often at odds with ecological observations demonstrating stable dynamics even for a high nutrient load. This apparent discrepancy is known in the literature as Rosen- zweig’s “paradox of enrichment”. Recent theoretical works emphasize a crucia…

Conditions for the spread of conspicuous warning signals: A numerical model with novel insights

2007

The initial evolution of conspicuous warning signals presents an evolutionary problem because selection against rare conspicuous signals is presumed to be strong, and new signals are rare when they first arise. Several possible solutions have been offered to solve this apparent evolutionary paradox, but disagreement persists over the plausibility of some of the proposed mechanisms. In this paper, we construct a deterministic numerical simulation model that allows us to derive the strength of selection on novel warning signals in a wide range of biologically relevant situations. We study the effects of predator psychology (learning, rate of mistaken attacks, and neophobia) on selection. We a…