Improving Gas Reactor Design with Complex Non-Standard Reaction Mechanisms in a Reactive Flow Model

Fluorinated gases are critical to a number of high-technology industries including semiconductor manufacturing and related processes such as flat panel display, LED, and photovoltaic manufacturing. These fluorinated gases have very high global warming potentials (GWPs) and, unfortunately are chemically very stable, in some cases lasting for thousands of years in the atmosphere. For environmental reasons, it is imperative that the release of these gases be minimized, but existing methods to destroy them requires a significant amount of energy. The goal of this project was to develop a more energy efficient method of destroying these high GWP gases using computational fluid dynamics, bringing together resources available at the national labs, including high-performance computing hardware and modern computational methods, in order to explore an industrially important problem with key environmental and economic impact. This exploratory project has demonstrated that HPC can indeed provide a unique view into a complex engineering problem - one that is simply inaccessible by any other means. The tools allow one to explore the details of the chemical process, and construct ``what-if'' scenarios to address shortcomings of the physical device in its current operating modes. However, as with many sources of completely new information, many new questions are illuminated with this capability. It will take considerable time, effort and experience before we learn to probe the solutions, pose operating scenarios and confirm modifications to the device that lead to real engineering advances

A spectral deferred correction strategy for low Mach number reacting flows subject to electric fields

We propose an algorithm for low Mach number reacting flows subjected to electric field that includes the chemical production and transport of charged species. This work is an extension of a multi-implicit spectral deferred correction (MISDC) algorithm designed to advance the conservation equations in time at scales associated with advective transport. The fast and nontrivial interactions of electrons with the electric field are treated implicitly using a Jacobian-Free Newton Krylov approach for which a preconditioning strategy is developed. Within the MISDC framework, this enables a close and stable coupling of diffusion, reactions and dielectric relaxation terms with advective transport and is shown to exhibit second-order convergence in space and time. The algorithm is then applied to a series of steady and unsteady problems to demonstrate its capability and stability. Although developed in a one-dimensional case, the algorithmic ingredients are carefully designed to be amenable to multidimensional applications

Improving Gas Reactor Design with Complex Non-Standard Reaction Mechanisms in a Reactive Flow Model

Fluorinated gases are critical to a number of high-technology industries including semiconductor manufacturing and related processes such as flat panel display, LED, and photovoltaic manufacturing. These fluorinated gases have very high global warming potentials (GWPs) and, unfortunately are chemically very stable, in some cases lasting for thousands of years in the atmosphere. For environmental reasons, it is imperative that the release of these gases be minimized, but existing methods to destroy them requires a significant amount of energy. The goal of this project was to develop a more energy efficient method of destroying these high GWP gases using computational fluid dynamics, bringing together resources available at the national labs, including high-performance computing hardware and modern computational methods, in order to explore an industrially important problem with key environmental and economic impact. This exploratory project has demonstrated that HPC can indeed provide a unique view into a complex engineering problem - one that is simply inaccessible by any other means. The tools allow one to explore the details of the chemical process, and construct ``what-if'' scenarios to address shortcomings of the physical device in its current operating modes. However, as with many sources of completely new information, many new questions are illuminated with this capability. It will take considerable time, effort and experience before we learn to probe the solutions, pose operating scenarios and confirm modifications to the device that lead to real engineering advances

OpenFOAM simulations of impinging coflow flames, including chemi-ionization and electric field

Electric fields can have several effects on the behavior of hydrocarbon flames: they may affect flame shape, burning velocity, temperature profile, speed of propagation, lift-off distance, species diffusion, stabilization, and extinction. The reason is that combustion of hydrocarbon fuels involves a chemi-ionization process, which generates electrically charged species, namely ions and electrons; external manipulation of these chemi-ions can potentially produce two major effects on the flame: (1) alteration of the chemical kinetics and (2) generation of a body force. The former arises because the chemistry of the system is affected by the redistribution of charges due to their mobility and to the direction of the applied electric field; the latter includes physical effects: ion wind and Ohmic heating.The applied electric field makes charged species acquire momentum, which is then lost during collisions with neutral molecules; these multiple collisions have two consequences. Chemi-ions gain a drift velocity, which depends on their mobility, that is what makes them travel toward the respective oppositely charged electrode; while neutral molecules gain a small net velocity in the same direction (known as ion wind effect), which produces a net force whose contribution is included in the momentum equation.The Ohmic heating represents the work done by electrostatic forces; it includes both the work done by the electric field on the charged species (by pushing them toward the electrode of opposite charge) and the work done by the chemi-ions themselves (because they have also a diffusion velocity).The aim of this thesis is to better understand, through numerical simulations, the effects of chemi-ionization and electric fields on a non-premixed coflow flame that impinges on a metallic plate; this configuration is very useful in order to investigate both how electric fields can be used to reduce carbon monoxide emissions and how they affect the heat flux on a solid surface. In order to analyze how chemi-ionization and electric fields influence the fluid dynamics and the chemistry of a flame in this configuration, numerical simulations have been performed using OpenFOAM. The validation of the numerical model has been performed by comparing numerical results to experimental result; these comparisons show that, taking into account some simplifying assumptions (e.g., axialsymmetric geometry, absence of radiation heat losses, unitary Lewis and Schmidt number) introduced in the model, results agree well with literature findings

Multidisciplinary Treatment for Childhood Obesity: A Two-Year Experience in the Province of Naples, Italy

Childhood obesity must be faced through an integrated multi-level preventive approach. This study was aimed at assessing the adherence and the outcomes of an outpatient service for childhood obesity treatment activated in the province of Naples, Italy, throughout a 2-year follow-up period. At first visit (T0), weight, height, waist circumference, and body composition of children were assessed, together with sociodemographic features and physical activity levels of children and parents. Anthropometric and body composition parameters of children were measured at 6 ± 3 months (T1) and 12 ± 3 months (T2). A total of 451 non-related children who accessed the service were analyzed: 220 (48.7%) of them returned at least once (attrition rate 51.3%). Returner outpatients showed higher age (p = 0.046) and father's educational level (p = 0.041) than non-returner ones. Adherence to the treatment was found to be related to father's (Rho = 0.140, p = 0.005) and mother's (Rho = 0.109, p = 0.026) educational level. All the outcomes improved between T0 and T1 (p < 0.001), while only body mass index (BMI) decreased significantly at T2. Changes in BMI-SDS were associated with baseline value (OR 0.158, 95%CI 0.017-0.298, p = 0.029). The multidisciplinary approach seems to be promising to treat childhood obesity in this geographic context. Lower parents' educational level should be considered as an attrition determinant

Adapted Physical Activity for the Promotion of Health and the Prevention of Multifactorial Chronic Diseases: the Erice Charter

The Erice Charter was unanimously approved at the conclusion of the 47th Residential Course "Adapted Physical Activity in Sport, Wellness and Fitness: New Challenges for Prevention and Health Promotion", held on 20-24 April 2015 in Erice, Italy, at the "Ettore Majorana" Foundation and Centre for Scientific Culture, and promoted by the International School of Epidemiology and Preventive Medicine "G. D'Alessandro" and the Study Group on Movement Sciences for Health of the Italian Society of Hygiene, Preventive Medicine and Public Health. After an intense discussion the participants identified the main points associated with the relevance of physical activity for Public Health, claiming the pivotal role of the Department of Prevention in coordinating and managing preventive actions. The participants underlined the importance of the physicians specialized in Hygiene, Preventive Medicine and Public Health. The contribution of other operators such as physicians specialized in Sport Medicine was stressed. Further, the holders of the new degree in Human Movement and Sport Sciences were considered fundamental contributors for the performance of physical activity and their presence was seen as a promising opportunity for the Departments of Prevention. Primary prevention based on recreational physical activities should become easily accessible for the population, avoiding obstacles such as certification steps or complex bureaucracy. The Sport Doctor is recognized as the principal referent for preliminary physical evaluation and clinical monitoring in secondary and tertiary prevention actions based on adapted physical activities. Developing research in the field is essential as well as implementing higher education on physical activity management in Schools of Public Health