Abstract
With the growing importance of renewable energy, the interest in energy-harvesting technologies based on flow-induced vibrations of airfoils has been rekindled in the past few years. ...Compared to conventional turbines, these devices are centrifugal stress-free and hence they are structurally more robust. They are also environmentally friendly due to the relatively low speeds, thus reducing the impact on flying animals. In order to numerically investigate these types of devices, mesh motion techniques must be used so that the computational grid can adapt to the time-varying shape of the domain and boundaries, thus preserving its robustness and quality. During the last years, many different dynamic mesh approaches have been developed to better predict the behaviour of a flow interacting with solid moving bodies. The aim of the present work is to apply and validate the overset grid method offered by the OpenFOAM software. In this type of mesh, one or more grid blocks are allowed to overlap with other sets of cells to solve the fluid domain with moving bodies, thus showing many potential advantages compared to the other existing dynamic mesh approaches. In the first part of this work, a numerical investigation of the flow over a stationary SD 7003 airfoil at low Reynolds number has been performed using an unsteady RANS approach. The computed results have then been compared to experimental and high-fidelity computational data available from the literature in order to validate the presented model in terms of numerical domain configuration, mesh refinement, and turbulence modelling. Subsequently, unsteady RANS simulations have been performed on the SD 7003 and NACA 0012 airfoils for two different amplitudes of flapping motion, i.e., 30° and 45°. Finally, the results obtained with the OpenFOAM overset grid solver have been compared with the numerical and experimental benchmarks presented by Kurtulus, showing an excellent agreement with both computed and measured data.
•Numerical investigation of an industrial gas turbine lean premixed burner through a high-fidelity CFD approach.•Validation of the numerical setup through a direct comparison with experimental ...data.•Assessment of the flame shape prediction of two enhanced versions of the FGM and ATF combustion models.•Remarkable accuracy in predicting the flame topology exhibited by both models.•Assessment of both turbulent combustion models in supporting burner design phase.
In the pursuit of decarbonization, the reduction of greenhouse gas emissions from power generation through gas turbine (GT) engines plays a crucial role in the whole industrial sector. As industries strive to transition towards cleaner energy sources, the design and optimization of novel GT burners require a deep comprehension of the complex interaction between fluid dynamics and combustion processes embedded within the system. Computational Fluid Dynamics (CFD) plays a pivotal role in these processes by providing valuable insights into the complex flow patterns, flame topology, and stability limits within the combustor. Concurrently, the burner design phase necessitates a considerable number of simulations to ascertain flame stability limits under various burner designs and operating conditions. Therefore, it is imperative to control computational costs while ensuring a high level of accuracy. The present work is focused on a comprehensive comparative analysis of two widely employed turbulent combustion closure models: the Flamelet Generated Manifold (FGM) and the Artificially Thickened Flame (ATF). Both models utilize extended versions with specific modifications aimed at effectively addressing their respective limitations. The investigation is performed through a Large Eddy Simulation (LES) based CFD analysis within the context of a lean premixed burner designed by Baker Hughes and operated with methane at atmospheric pressure. The primary benchmark for numerical validation will be provided by detailed chemiluminescence images from a test campaign conducted by the University of Florence, thereby yielding valuable insights into flame topology and positioning. Furthermore, potential disparities in the flow field and fuel concentration at the burner exit between the two models will be revealed.
Five Lotus tenuis genotypes showing 2n pollen production greater than 5% and producing 4x progenies in 4x(male sterile Lotus corniculatus) × 2x crosses were found in different natural populations. ...Meiotic analyses of these plants showed some second metaphases with disoriented spindles, i.e. parallel and tripolar spindles which resulted in diads and triads, respectively. Because useful genes for winter growth and resistance to powdery mildew from L. tenuis can be introgressed into L. corniculatus via 2n gametes, a programme of selection was started to increase the occurrence of 2n gamete production in L. tenuis. Controlled crosses were performed between genotypes producing 2n gametes and the progenies were checked for 2n pollen production and meiotic aberration, following the same methodologies as used for the parental plants. Although in some progeny plants the frequency of 2n gamete production increased remarkably, the overall progeny level of 2n gamete production remained unchanged. This suggested that different genes for meiotic aberration exist in natural populations and/or differential seed‐setting ability exists between genotypes. Diallel crosses between selected genotypes confinned this hypothesis. Evaluation of 2n pollen production of clones grown under different temperature regimes (warm vs. temperate) showed that, in L. tenuis, the effects of genotype, temperature and genotype × temperature interaction are significant. In particular, high temperature increases the level of 2n gamete production in L. tenuis.
Two meiotic mutants of L. tenuis (2n = 2x = 12) producing unreduced pollen are described. When crossed to male sterile Locus corniculatus (2n = 4x = 24) plants, all progeny plants were ...morphologically similar to L. corniculatus, had 2n = 24 chromosomes, and in the cross, were fully compatible with L. corniculatus, indicating that the male parent plants were 2n-pollen producers. One of them also had 'giant' pollen grains. In metaphase 11 of both genotypes, there were parallel and tripolar spindles leading to dyad and triad formation, the latter being found most frequently. Since both the above-mentioned mechanisms result in first-division restitution-type microspores, the genotypes examined could be useful in breeding Lotus.
Introduction
In Italy, subjects with severe mental illness (SMI) considered “in danger of posing a threat to others” are hospitalized into structures known as “
REMS–Residenze per l’Esecuzione delle ...Misure di Sicurezza
”, designed to provide rehabilitating programs. There are also specialized forensic teams to support Community Mental Health Centers (CMHC) in helping patients who committed crimes. A better characterization of clinical and real-world functioning of forensic patients represents a topic of clinical interest (Caruso R
et al
. Curr Psychiatry Rep 2021; 7 29; Barlati
et al
. Eur Arch Psychiatry Clin Neurosci 2022,
in press
; Fazel
et al
. Br J Psychiatry. 213 609-614).
Objectives
Aims were to compare clinical and psychosocial functioning characteristics in three cohorts of SMI patients.
Methods
A total of 29 patients hospitalized in REMS facilities were included into this study; starting from this first group an equal number of individuals matched for sex, age, and diagnosis were included in other two groups of outpatients cared for by the forensic team and of non-forensic outpatients treated by CMHC. Clinical severity was measured through the Clinical Global Impression scale – Severity (CGI-S) and real-world functioning was measured through the Personal and Social Performance scale (PSP). Analyses included Chi-Square test for categorical variables and Kruskall-Wallis test for continuous variables with Mann-Withney U test for post/hoc comparisons. P values < 0.05 were considered significant.
Results
Significant between-groups differences emerged regarding psychosocial functioning (p=0.013): that was more compromised in the REMS group (mean:34.0) when compared to the forensic team subjects (mean:41.3) and to the subjects in the CMHC group (mean:47.7).
Results concerning clinical severity point in the opposite direction: more severe symptoms were observed in the CMHC group (mean:4.7) compared to the REMS group (mean: 4.3) and the forensic outpatients (mean:3.5). The difference in the CGI-S mean scores is significant for the forensic outpatients when compared to the REMS group (p=0.011) and to the CMHC group (p<0.001).
Conclusions
Specialized teams are central in the managing of forensic patients: of particular interest are the data regarding clinical symptoms severity, which could also be read with a de-stigmatizing focus, highlighting that a worse clinical severity is not associated with being more dangerous to other people and to the society in general.
Disclosure of Interest
None Declared
In the contemporary age of big data and sharing intelligence, tourism market has constantly changing scenario thanks to the unceasing communication technologies’ revolution. According to this growth ...perspective, cultural heritage tourism is increasing his offer quality standards, by giving evidence of its social and territorial identity value. In light of this, the research is focused on the study of hospitality places located along the Vie ROMEE maiores (Via Francigena, Via Romea Strata and Via Romea Germanica), the most famous slow tourism product in Italy, that has recently been promoted in such original ways. In particular, the paper describes the touristic system of San Pellegrino in Alpe, a village located on the Tuscan and Emilian Via Francigena route, with the final aim to suggest a touristic renovation model in light of the current Covid-19 changing scenario. Therefore, the research study shows how local stakeholders are able to foster territorial promotion activities, both for residents and for tourists, in order to empower local tourism system and local community awareness. In this context, the new marketing tools for virtual tourism, videomaking and crowdfunding play a strategic role for local tourism development; especially when they are used by stakeholders, such as Film Commissions and small local museums to assure a better quality of life in sustainable tourism destinations.
A ML=5.8 earthquake rocked the L'Aquila area on April 6, 2009. Several aftershocks characterized by 5<ML<4 followed the main seismic event. The depth of mainshock was about 9km and the same region ...has been hit by strong earthquakes during the past centuries. Possible phenomena related to underground fluid dynamics due to the seismic sequence were reported. Sensors capable of monitoring water level variations and temperatures in selected spring sources of Central Italy were placed in the studied area and their data processed. Fluid sensors located at different distances from the epicentral area were differently affected by the seismic sequence. Collected data during the seismic swarm are discussed and compared to contemporary data recorded by satellite-based techniques.
► Groundwaters were monitored during the April 2009 central Italy seismic swarm. ► The existence of postseismic, coseismic and preseismic signals is discussed. ► The signals pattern strongly influence the interpretation of local fluid related phenomena. ► Eventual preseismic crustal deformative processes could be happened far from epicenters.
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