A macroscopic particle modelling approach for non-isothermal solid-gas and solid-liquid flows through porous media

© 2019 Elsevier Ltd The complexity of multiphase flows in many engineering systems such as heat exchangers signify the need to develop new and advanced numerical models to analyse the interactions the working fluid and unwanted solid foulants. Fouling is present in a myriad of industrial and domestic processes and it has a negative impact on the economy and the environment. The mechanisms that govern non-isothermal solid-fluid flow through porous metal foam heat exchangers are complex and poorly understood. In this research, a coupled finite volume method (FVM) and macroscopic particle model (MPM) is developed and implemented in ANSYS Fluent to examine the transient evolution of a non-isothermal multiphase solid-fluid flow and the interaction between coupled interactions of solid particles, fluid, and porous media. The maximum particle temperature is dependent on the fluid and solid particle thermo-physical properties in addition to the temperature of the cylindrical ligaments of the porous media. The present results show that the smallest solid particles reach the highest temperatures in the porous heat exchanger and at low inlet velocities, the highest particle temperatures are realized. The results pertaining to maximum particle temperatures are prevalent in many industrial processes and acquiring knowledge of the maximum particle temperature serves as a steppingstone for comprehending complex multiphase solid-fluid flows such as the cohesiveness between the particles and the particle adhesion with the walls. The results of these studies could potentially be used in the future to optimize metal foam heat exchanger designs

Acute health shocks and labour market outcomes

We investigate the labour supply response to acute health shocks experienced in the post-crash labour market by individuals of working age, using data from Understanding Society. Identification exploits uncertainty in the timing of an acute health shock, defined by the incidence of cancer, stroke, or heart attack. Results, obtained through a combination of coarsened exact and propensity score matching, show acute health shocks significantly reduce participation, with younger workers displaying stronger labour market attachment. The impact on older, more educated, women suggests an important role for preferences, financial constraints, and intra-household division of labour determining labour supply decisions

Market structure and technology: evidence from the Italian National Health Service

Sutton (1991, Sunk costs and market structure. Cambridge: MIT Press; 1998, Technology and market structure. Cambridge: MIT Press) theorised that industries evolve into distinct market configurations in terms of concentration, depending upon product homogeneity and whether R&D or advertising are relevant relative to set-up costs. This paper tests the existence of such a relationship between technological profiles and market structure empirically, using the health care services provided by the Italian National Health Service as the specific economic framework. Our results support the empirical predictions made by Sutton. In particular, inmarkets where the technological intensity is low the lower bound to concentration converges monotonically to zero when the market size increases, for any level of product homogeneity. Conversely, in markets where the technological intensity is high the lower bound of concentration converges to some positive (non-zero) value when market size increases, while the lower bound increases (from zero) when the level of product homogeneity increases

Market structure and technology: evidence from the Italian National Health Service

Sutton (1991, 1998) theorised that industries evolve into distinct market configurations in terms of concentration, depending upon product homogeneity and whether R&D or advertising are relevant relative to set-up costs. This paper tests the existence of such a relationship between technological profiles and market structure empirically, using the health care services provided by the Italian National Health Service as the specific economic framework. Our results support the empirical predictions made by Sutton. In particular, in markets where the technological intensity is low the lower bound to concentration converges monotonically to zero when the market size increases, for any level of product homogeneity. Conversely, in markets where the technological intensity is high the lower bound of concentration converges to some positive (non-zero) value when market size increases, while the lower bound increases (from zero) when the level of product homogeneity increases

Struttura di mercato e tecnologia: un\u92analisi empirica del Servizio sanitario nazionale italiano

L’accelerazione dello sviluppo tecnologico e la tendenza verso il decentramento dell’intervento pubblico, caratteristiche dei mercati sanitari negli ultimi decenni, hanno contribuito ad accrescere l’autonomia decisionale dei soggetti che operano in questi mercati, rendendone il funzionamento simile a quello dei settori industriali tradizionali. Un riferimento standard dell’economia industriale sulla relazione tra la tecnologia e la struttura di mercato è offerto dal contributo di Sutton (1991, 1998), secondo cui i settori industriali assumono configurazioni differenti in termini di concentrazione di mercato a seconda della diversa incidenza delle spese di R&S e di pubblicità e dell’omogeneità dei prodotti in essi offerti. L’obiettivo di questo lavoro è testare empiricamente alcune delle relazioni evidenziate da Sutton nell’ambito di uno specifico contesto economico, quello delle prestazioni sanitarie offerte dal Servizio sanitario nazionale italiano. L’analisi si basa su un dataset, fornito dal Ministero della salute, che raccoglie informazioni sulle prestazioni sanitarie (sia in regime di ricovero ordinario che day-hospital) offerte nel 2001 da tutte le strutture ospedaliere operanti nell’ambito del Servizio sanitario nazionale. I risultati sono in linea con le predizioni empiriche della teoria di Sutton, secondo le quali nei mercati a bassa intensità di R&S esiste un lower bound per la concentrazione d’equilibrio, e tale lower bound converge monotonicamente a zero all’aumentare della dimensione del mercato (rapportata ai costi di set-up), indipendentemente dal livello di omogeneità del prodotto. Nei mercati ad alta intensità di R&S, invece, il lower bound alla concentrazione converge ad un valore positivo diverso da zero all’aumentare della dimensione di mercato, mentre cresce a partire da zero all’aumentare del livello di omogeneità del prodotto

Contractual Conditions, Working conditions, Health and Well-Being in the British Household Panel Survey

We consider the effects of contractual and working conditions on self-assessed health and psychological well-being using twelve waves (1991/92 – 2002/2003) of the British Household Panel Survey. While one branch of the literature suggests that “atypical” contractual conditions have a significant impact on health and well-being, another suggests that health is damaged by adverse working conditions. As far as we are aware, previous studies have not explicitly considered the two factors jointly. Our aim is to combine the two branches of the literature to assess the distinct effects of contractual and working conditions on health and psychological well-being and how these effects vary across individuals. For self-assessed health the dependent variable is categorical, and we estimate non-linear dynamic panel ordered probit models, while for psychological well-being we estimate a dynamic linear specification. Our estimates show that being unsatisfied with the number of hours worked has a negative influence on the health of individuals who have a part-time job. Having a high level of employability appears to influence positively the health and psychological well-being of individuals with temporary job arrangements. Family structure appears to influence the health and well-being of workers with atypical contractual conditions.working conditions, contractual conditions, self assessed health, psychological well-being, dynamic panel data models