Thermoconvective instability and local thermal non-equilibrium in a porous layer with isoflux-isothermal boundary conditions

The effects of lack of local thermal equilibrium between the solid phase and the fluid phase are taken into account for the convective stability analysis of a horizontal porous layer. The layer is bounded by a pair of plane parallel walls which are impermeable and such that the lower wall is subject to a uniform flux heating, while the upper wall is isothermal. The local thermal non-equilibrium is modelled through a two-temperature formulation of the energy exchange between the phases, resulting in a pair of local energy balance equations: one for each phase. Small-amplitude disturbances of the basic rest state are envisaged to test the stability. Then, the standard normal mode procedure is adopted to detect the onset conditions of convective rolls. Beyond the Darcy-Rayleigh number, playing the role of order parameter for the transition to instability, the relevant dimensionless parameters are the inter-phase heat transfer parameter and the thermal conductivity ratio. The disturbance governing equations, formulated as an eigenvalue problem, are solved numerically by a shooting method. Results are reported for the neutral stability curves and for the critical values for the onset of instability

A New Approach for the Modelization of Water and Steam Mixing at High Pressure Conditions

Abstract In the present paper a zero-dimensional thermodynamic model of liquid water and steam mixing is presented. The model provides the temperature distribution during the mixing process, as an exponential function of time. A comparison with experimental data is performed, showing an excellent agreement. In the experimental set up, steam from an adiabatic high pressure storage is mixed, in a mixing chamber, together with liquid water. Measures of the temperature both on the inner and outer surface of the mixing chamber are taken. A comparison between the experimental data and the thermodynamic model proposed shows that the heat transfer between the mixing chamber and the environment is negligible. Moreover, a discussion on the time dependency of the experimental pressure and of the theoretical internal energy of the steam is presented

Gill's problem in a sandwiched porous slab

The classical Gill's stability problem for the stationary and parallel buoyant flow in a vertical porous slab with impermeable and isothermal boundaries kept at different temperatures is reconsidered in a different perspective. A three-layer slab is studied instead of a homogeneous slab as in Gill's problem. The three layers have a symmetric configuration where the two external layers have a high thermal conductivity, while the core layer has a much lower conductivity. A simplified model is set up where the thermal conductivity ratio between the external layers and the internal core is assumed as infinite. It is shown that a flow instability in the sandwiched porous slab may arise with a sufficiently large Rayleigh number. It is also demonstrated that this instability coincides with that predicted in a previous analysis for a homogeneous porous layer with permeable boundaries, by considering the limiting case where the permeability of the external layers is much larger than that of the core layer

Data-driven social innovation: a methodology to support employees of retail shops

Showrooming is a social issue of small-medium shops at the worldwide level. This problem means customers are going to physical stores to try products and buy on-line from the competitor. It is a pressing issue for both shops owners and sales assistants. Shop owners are suffering from the reduction of revenue and number of customers, who are buying on-line (i.e. e-commerce Giants are more convenient in terms of pricing and delivery of products). And sales assistants are being pressured to work more and having their performance tracked every day. From this phenomenon, this research analyzes the way a public-private partnership (PPP) is developing data-driven social innovation. The main contribution of this paper is a methodology to support sales assistants of small-medium shops to increase performance and well-being. The results of this paper expand the field of social innovation by creating a new method capable of increasing employee performance and well-being

“Longe, mas juntos”: experiências vividas em um festival de ginástica para todos em tempos de pandemia

Covid-19 pandemic has brought changes in different spheres of the society around the world. In sport, besides the training routine, an important aspect was impacted during this period, sports events. Based on the phenomenological theory of Merleau-Ponty, the aim of this study was to describe lived experiences in a Gymnastics for All festival, held remotely. We adhere to the phenomenological analysis using triangulation of documentary data, field notes and focus groups within gymnasts that raised two themes: a) Apart, but together and b) Virtuality “modus operandi”. Although remote, the perception of the experience listed typical feelings and sensations of sports and the value of events, such as the aesthetic attitude, the search for (self) overcoming, recognition and social belonging.La pandemia de covid-19 instituido cambios en diversos ámbitos de la sociedad en todo el mundo. En el deporte, más allá de los entrenamientos rutinarios, una importante esfera ha sufrido impactos en este periodo, la de los eventos. Basado en la teoría fenomenológica de Merleau-Ponty, el objetivo de este estudio es describir las experiencias vividas en un festival de Gimnasia para Todos realizado en forma remota. Adherimos al análisis fenomenológico en la triangulación de datos documentales, diarios de campo y grupos focales con gimnastas participantes alrededor de dos temas: a) “Distantes, pero juntos”; b) “El modus operandi de la virtualidad”. Aunque remota, la percepción de la experiencia recogía sentimientos y sensaciones típicas del quehacer deportivo y una valoración positiva de los eventos, así como la actitud estética intrínseca a la gimnasia,la  búsqueda de la (auto) superación, el reconocimiento y  la pertenencia social.A pandemia de covid-19 vem instituindo mudanças em diferentes âmbitos da sociedade no mundo. No esporte, para além dos treinos rotineiros, uma importante esfera sofreu impactos neste período, a dos eventos. Pautado na teoria fenomenológica de Merleau-Ponty, o objetivo deste estudo foi descrever experiências vividas em um festival de Ginástica para Todos realizado de maneira remota. Aderimos à análise fenomenológica na triangulação de dados documentais, diários de campo e grupos focais com ginastas participantes que suscitaram em duas temáticas: a) “Distantes, mas juntos” e b) “O modus operandi da virtualidade”. Ainda que remoto, a percepção da experiência elencou sentimentos e sensações típicas do fazer-esportivo e sua estima aos eventos, como a atitude estética intrínseca à ginástica, busca de (auto) superação, reconhecimento e pertencimento social

Down-regulation of the LXR transcriptome provides the requisite cholesterol levels to proliferating hepatocytes

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Development of a tool to optimize economic and environmental feasibility of food waste chains

11 figures, 6 tables.-- Supplementary information available.The Sustainable Development Goal 12.3 focuses on food and its inedible parts that exit the supply chain and thus are lost or wasted. This work addresses the food waste problem by presenting the development of a tool to design business models to reduce the production of food waste. This has been developed within the LIFE16 project iRexfo, coordinated by the University of Perugia. The tool aims at transferring the results obtained in a pilot region (Umbria, Italy) to 4 other regions in Europe. It has been coded in Python and has a graphical user interface (GUI) to insert inputs and display outputs. The GUI has been developed in FLASK and it is hosted in the website of PythonAnywhere. A case study on the application of the software is also presented, mainly based on data retrieved in the Umbria region, Italy. Together with economic analysis, also, environmental assessment is performed.Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. i-REXFO LIFE (LIFE16ENV/IT/000547) is a project funded by the EU under the LIFE 2016 program. This work has been partially funded by the GTCLC-NEG project that has received funding from the European Union’s Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement No. 101018756.Peer reviewe

Accumulative Difference Image Protocol for Particle Tracking in Fluorescence Microscopy Tested in Mouse Lymphonodes

The basic research in cell biology and in medical sciences makes large use of imaging tools mainly based on confocal fluorescence and, more recently, on non-linear excitation microscopy. Substantially the aim is the recognition of selected targets in the image and their tracking in time. We have developed a particle tracking algorithm optimized for low signal/noise images with a minimum set of requirements on the target size and with no a priori knowledge of the type of motion. The image segmentation, based on a combination of size sensitive filters, does not rely on edge detection and is tailored for targets acquired at low resolution as in most of the in-vivo studies. The particle tracking is performed by building, from a stack of Accumulative Difference Images, a single 2D image in which the motion of the whole set of the particles is coded in time by a color level. This algorithm, tested here on solid-lipid nanoparticles diffusing within cells and on lymphocytes diffusing in lymphonodes, appears to be particularly useful for the cellular and the in-vivo microscopy image processing in which few a priori assumption on the type, the extent and the variability of particle motions, can be done

Notulae to the Italian flora of algae, bryophytes, fungi and lichens: 14

In this contribution, new data concerning bryophytes, fungi and lichens of the Italian flora are presented. It includes new records and confirmations for the algal genus Chara, for the bryophyte genera Bryum, Grimmia, Cephaloziella, Hypnum, Nogopterium, Physcomitrium, Polytrichastrum, Rhynchostegiella, Saelania, and Schistostega, the fungal genera Cortinarius, Lentinellus, Omphalina, and Xerophorus, and the lichen genera Acarospora, Agonimia, Candelariella, Cladonia, Graphis, Gyalolechia, Hypogymnia, Lichinella, Megalaria, Nephroma, Ochrolechia, Opegrapha, Peltigera, Placidium, Ramalina, Rhizoplaca, Ropalospora, Strangospora, Toniniopsis, Usnea, and Zahlbrucknerell