Improved angular discretization and error analysis of the lattice boltzmann method for solving radiative heat transfer in a participating medium

In this paper, some improvements to the lattice Boltzmann method (LBM) for solving radiative heat transfer in a participating medium are presented and validated. Validation of the model is performed by investigating the effects of spatial and angular discretizations and extinction coefficient on the solution. The error analysis and the order of convergence of the scheme are also reporte

What Is Our Point of View on “Energy Independence and Research for Economic and Environmental Sustainability”?

The scope of this contribution is to stimulate critical debate on what are the implication of “energy independence” and “energy research” on the sustainable development of society. We point out how energy independence is strongly related to the penetration of renewable energy sources; and how the country's energy independence is not expected to be achieved in a short-medium period. Moreover, the trends of low found to the research on energy topics are not consistent with the pursuit of sustainable development of society. With these observations, we want to contribute to the debate on what policies that will have an impact on the sustainable development of society, suggesting to focus on the point of view of those actors that will play the main role in the next future

The role of electron capture decay in the precision era of Galactic cosmic-ray data

Electron capture (EC) decay relies on attachment and stripping cross-sections, that in turn, depend on the atomic number of the nucleus. We revisit the impact of EC decay in the context of the high-precision cosmic-ray fluxes measured by the AMS-02 experiment. We derive the solution of the steady-state fluxes in a 1D thin disk model including EC decay. We compare our results with relevant elemental and isotopic fluxes and evaluate the impact of this process, given the precision of recent AMS-02, ACE-CRIS, SuperTIGER, and Voyager data. We find this impact to be at the level or larger than the precision of recently collected data for several species, e.g. $_{31}$Ga and $_{33}$As, indicating that EC decay must be properly taken into account in the calculation.Comment: 8 pages, 3 figures, Proceedings for International Cosmic Ray Conference (ICRC) 202

Experimental Study of Extinguishing Shielded Fires by a Low-pressure Multi-orifice Water Mist Nozzle

The performance of a water mist system to suppress shielded fires is analyzed experimentally in this work. The diesel pool fire is used as the fire source in an enclosure with 2.4 m × 2.4 m × 3.1 m measurements, and a mechanism is designed to provide different shielding conditions by changing the obstacle size and height. The characteristics of a low-pressure multi-orifice nozzle including the drop diameter and the velocity are studied by a Phase Doppler Particle Analyzer (PDPA) system. In total, 10 cases with diverse shielding conditions are defined and different parameters including the temperature distribution, the gas concentrations, and the extinguishing time are measured. Based on the present data, mist droplets in some shielded fire scenarios were able to bypass the obstacle, overcome the fire plume thrust, and suppress the fire. In fire scenarios with the same obstruction size, the reduction of the distance between the obstacle and the nozzle led to an increased block ratio and consequently, the extinguishing time was decreased. It was found that the temperatures in the central axis above the fire and the lateral temperatures declined quickly in cases with short suppression time

The Bright and Dark Side of DNA Methylation: A Matter of Balance

DNA methylation controls several cellular processes, from early development to old age, including biological responses to endogenous or exogenous stimuli contributing to disease transition. As a result, minimal DNA methylation changes during developmental stages drive severe phenotypes, as observed in germ-line imprinting disorders, while genome-wide alterations occurring in somatic cells are linked to cancer onset and progression. By summarizing the molecular events governing DNA methylation, we focus on the methods that have facilitated mapping and understanding of this epigenetic mark in healthy conditions and diseases. Overall, we review the bright (health-related) and dark (disease-related) side of DNA methylation changes, outlining how bulk and single-cell genomic analyses are moving toward the identification of new molecular targets and driving the development of more specific and less toxic demethylating agents

Development of a methodology for studying tunnel climate in long railway tunnels and for optimizing the design process of cross-passage cooling systems

When it comes into operation in 2026, the Koralmtunnel in Austria will be the world́s seventh longest railway tunnel. The installation of the power supply, telecommunications and electro-mechanical services is currently ongoing. Parts of these systems have to be protected from temperature and humidity variations and from the high dust loads which are characteristic of the tunnel atmosphere. In particular, cooling systems are required to counteract the significant amounts of heat released by some installations. Information on a large number of parameters (e.g. tunnel air temperatures) is required in the design process. However, such information is only partly available in the design stage. Hence, a prediction of tunnel air temperatures has to be made. Additionally, since hardly any information about the tunnel climate in long railway tunnels is available and in-situ mea- surements are not possible, as thermal conditions differ significantly between the construction/equipping phase and the operation phase, a novel methodology for the prediction of the tunnel climate had to be developed. This article presents a description of a new method comprising four main investigative steps and of its application to the Koralmtunnel as a selected case study. While steps 1 and 2 provide information about the actual cooling requirement and tunnel air temperatures for a period of 50 years, steps three and four of the investigation aim at the technical and economic optimization of cooling systems

Feature Selection Techniques for CR Isotope Identification with the AMS-02 Experiment in Space

Isotopic composition measurements of singly charged cosmic rays (CR) provide essential insights into CR transport in the Galaxy. The Alpha Magnetic Spectrometer (AMS-02) can identify singly charged isotopes up to about 10 GeV/n. However, their identification presents challenges due to the small abundance of CR deuterons compared to the proton background. In particular, a high accuracy for the velocity measured by a ring-imaging Cherenkov detector (RICH) is needed to achieve a good isotopic mass separation over a wide range of energies. The velocity measurement with the RICH is particularly challenging for (Formula presented.) isotopes due to the low number of photons produced in the Cherenkov rings. This faint signal is easily disrupted by noisy hits leading to a misreconstruction of the particles’ ring. Hence, an efficient background reduction process is needed to ensure the quality of the reconstructed Cherenkov rings and provide a correct measurement of the particles’ velocity. Machine learning methods, particularly boosted decision trees, are well suited for this task, but their performance relies on the choice of the features needed for their training phase. While physics-driven feature selection methods based on the knowledge of the detector are often used, machine learning algorithms for automated feature selection can provide a helpful alternative that optimises the classification method’s performance. We compare five algorithms for selecting the feature samples for RICH background reduction, achieving the best results with the Random Forest method. We also test its performance against the physics-driven selection method, obtaining better results.</p