Reduced order modelling of combustion using convolutional neural network

It is well known that CFD simulations of a complex combustion system, such as Moderate or Intense Low-oxygen Dilution (MILD) combustion, requires consid- erable computational resources. This precludes various applications including the use of CFD in real time control systems. The idea of a reduced order model (ROM) was born from the desire to overcome this obstacle. A ROM, if properly instructed, returns the output of a requested CFD simulation in extremely short time. This one is an ideal mechanism with two basic gears: the input size reduction technique and the interpolation method. This project proposes a study on the applicability of convolutional neural network (CNN) as a dimensionality reduction technique. The code written for this purpose will be presented in detail, as well as pre and post processing. A sensibility analysis will be carry out to find out which parame- ters to adjust and how in order to achieve the optimum. Finally, the network will be compared in its peculiarity and its results with Principal Component Analysis (PCA), the technique used by the BURN group of Libre University of Bruxelles for the same purpose. Moreover with the desire to improve, we went further by trying to overcome the limits dictated by the rules of a legitimate comparation between PCA and CNN. Lastly, the author considers necessary to provide the theoretical basis in order to enrich and support what has just been described. Therefore, you will also find introductions / insights on MILD combustion, CFD of a combustion system, neural networks and the aspects related to them

Tecnología software de tiempo real y su implementación en protocolos de ciclo cerrado para neurociencia experimental

Tesis Doctoral inédita leída en la Universidad Autónoma de Madrid, Escuela Politécnica Superior, Departamento de Ingeniería Informática. Fecha de Lectura: 21-02-202

Measurement of the 235U(n,f) cross section relative to the 6Li(n,t) and 10B(n,a) standards from thermal to 170 keV neutron energy range at n_TOF

The 235U(n,f) cross section was measured in a wide energy range at n_TOF relative to 6Li(n,t) and 10B(n,alpha), with high resolution and in a wide energy range, with a setup based on a stack of six samples and six silicon detectors placed in the neutron beam. This allowed us to make a direct comparison of the reaction yields under the same experimental conditions, and taking into account the forward/backward emission asymmetry. A hint of an anomaly in the 10÷30 keV neutron energy range had been previously observed in other experiments, indicating a cross section systematically lower by several percent relative to major evaluations. The present results indicate that the evaluated cross section in the 9÷18 keV neutron energy range is indeed overestimated, both in the recent updates of ENDF/B-VIII.0 and of the IAEA reference data. Furthermore, these new high-resolution data confirm the existence of resonance-like structures in the keV neutron energy region. The new, high accuracy results here reported may lead to a reduction of the uncertainty in the 1÷100 keV neutron energy region. Finally, the present data provide additional confidence on the recently re-evaluated cross section integral between 7.8 and 11 eV.Preprin

Soil organic carbon significantly increases when perennial biomass plantations are reverted back to annual arable crops

Funding: This research was supported by funding from the Rural Developing Program (measure 16.01) of the Emilia Romagna region that financed the “FarmCO2Sink” EIP-AGRI operational group (grant number 5015651). Acknowledgments: The authors thank Mike Martin for his support in the modification of the ECOSSE source code.Peer reviewedPublisher PD

Prima misura simultanea delle reazioni 235U(n,f), 6Li(n,t) e 10B(n,α)

Sono indicate come "standard" un gruppo ristretto di sezioni d'urto di reazioni nucleari indotte da neutroni note con grande precisione e accuratezza, di grande importanza nel campo della fisica nucleare sperimentale. In questo lavoro è presentata l'analisi preliminare della prima misura simultanea delle sezioni d'urto standard 235U(n,f), 6Li(n,t) e 10B(n,alfa), realizzata presso la facility n_TOF (CERN) tramite un apparato di rivelazione basato su rivelatori allo stato solido in silicio. La misura è stata concepita in seguito ad anomalie sperimentali nell'intervallo fra 10 e 30 keV, rivelate in misure in cui la reazione 235U(n,f) era utilizzata come standard di riferimento, in particolare a LANSCE (USA) e nella precedente misura di flusso di n_TOF. In seguito all'analisi dei dati ed una caratterizzazione dell'apparato di rivelazione tramite simulazioni Monte Carlo, realizzate utilizzando il software Geant4, sono stati estratti i rapporti fra la sezione d'urto 235U(n,f) e gli standard 6Li(n,t) e 10B(n,alfa) nell'intervallo energetico dal termico (E_n = 0.0253 eV) a 100 keV. I risultati ottenuti sono generalmente in buon accordo con quelli presenti in letteratura, con deviazioni entro il 5%. Nell'intervallo energetico di maggiore interesse, ovvero fra 10 e 30 keV, si osserva invece una deviazione prossima al 10%, appare quindi confermata in questa regione una sovrastima della sezione d'urto 235U(n,f) nei dati presenti in letteratura

Reversible Total Vision Loss Caused by Severe Metformin-associated Lactic Acidosis: A Case Report.

INTRODUCTION: Metformin is a biguanide used to treat diabetes mellitus (DM). Metformin-associated lactic acidosis (MALA) carries a high mortality and can occur in patients with renal failure from drug bioaccumulation. Reversible vision loss is a highly unusual, rarely reported complication of MALA. We present a case of a patient whose serum metformin concentration was unusually high and associated with vision loss. CASE REPORT: A 60-year-old woman presented to an outside hospital emergency department with acute vision loss after being found at home confused, somnolent, and hypoglycemic, having last being seen normal two days prior. She reported vomiting and diarrhea during that time and a recently treated urinary tract infection. The visual loss resolved with continuous renal replacement therapy. CONCLUSION: This novel case of a patient with Type II DM prescribed metformin and insulin who developed reversible vision loss while suffering from MALA highlights the potential for vision loss in association with MALA

Assessment of Failure Frequencies of Pipelines in Natech Events Triggered by Earthquakes

During a seismic event, underground pipelines can undergo to significant damages with severe implications in terms of life safety and economic impact. This type of scenarios falls under the definition of Natech. In recent years, quantitative risk analysis became a pivotal tool to assess and manage Natech risk. Among the tools required to perform the quantitative assessment of Natech risk, vulnerability models are required to characterize equipment damages from natural events. This contribution is focused on the review of the pipeline vulnerability models available for the case of earthquakes. Two main categories of models have been identified in the literature. A first category proposes the repair rate as performance indicator for the damage of pipeline due to seismic load, and gives as output the number of required repairs per unit length. A second category proposes fragility curves associated with risk states depending on the mechanism of ground failure. In the framework of Natech risk assessment, the latter have the important advantage of having clearly and unambiguously defined the risk status (and thus the extent of the release) with which they are associated. A subset of vulnerability models deemed more appropriate to be applied in the framework of Natech risk assessment is then identified. Their application to the assessment of the expected frequencies of release events due to pipeline damage is provided, enabling their comparison and the discussion of the relative strengths and weaknesses