On pressure-driven Poiseuille flow with non-monotonic rheology.

Shear thickening fluids are liquids that stiffen as the applied stress increases. If many of these types of fluids follow a monotonic rheological curve, some experimental and numerical studies suggest that certain fluids, like cornstarch, may exhibit a non-monotonic, S-shaped rheology. Such non-monotonic behavior has however proved very difficult to observe experimentally in classical rheometer.

High-performance work practices and employee wellbeing: organizational identification as a mediator.

Aim: The aim of this study was to examine how high-performance work practices affect engagement and workplace bullying, two different aspects of employee wellbeing. Furthermore, the study sought to examine the potential mediating role of organizational identification in these relationships.

Method: A two-wave survey study ( = 213) was conducted among psychologists in Finland.

High-Performance Work Practices and Interpersonal Relationships: Leadership as a Risk Factor.

Although high-performance work practices (HPWPs) have been shown to increase organizational performance and improve employee attitudes, it still remains unclear how they impact interpersonal relations in the workplace. While some argue that HPWPs lead to better interpersonal relations, others fear that HPWPs may increase competition and uncivil and abusive behaviors. In response to this, our aim is to examine whether and when HPWPs are associated with increased levels of competition and thereby more incivility.

High Performance Work Systems, Justice, and Engagement: Does Bullying Throw a Spanner in the Works?

High performance work systems (HPWS) have typically been shown to positively influence employee attitudes and well-being. Research in the realm of HPWS has, in this respect, established a clear connection between these systems and employee engagement through organizational justice. In this study, we analyzed if being bullied affects this relationship.

Bullying behavior and employee well-being: how do different forms of social support buffer against depression, anxiety and exhaustion?

Purpose: Workplace bullying has severe negative consequences for the well-being of targeted employees. Previous research suggests that social support may buffer against such adverse effects. However, it remains unclear if different forms of support have equally strong effects and if support buffers equally effectively against different outcomes.

The last resort: Workplace bullying and the consequences of changing jobs.

This study investigated the consequences of changing jobs for employees subjected to workplace bullying. First, we hypothesized that bullied employees would be more likely to change jobs than non-bullied employees. Moreover, we hypothesized that changing jobs would result in a reduction of exposure to bullying behaviors and an alleviation of mental health problems for those bullied at baseline.

Putting workplace bullying in context: The role of high-involvement work practices in the relationship between job demands, job resources, and bullying exposure.

Previous research has demonstrated the crucial association between employee stressors and workplace bullying. In this article, we argue that a nurturing organizational context will protect employees from exposure to workplace bullying and will interact with individual demands and resources known to have effect on exposure to bullying in the workplace. In specific, we look at high-involvement work practices (HIWPs)-which include participation, information-sharing, competence development, and rewards.

Catalytic Antioxidant Activity of Bis-Aniline-Derived Diselenides as GPx Mimics.

Herein, we describe a simple and efficient route to access aniline-derived diselenides and evaluate their antioxidant/GPx-mimetic properties. The diselenides were obtained in good yields via ipso-substitution/reduction from the readily available 2-nitroaromatic halides (Cl, Br, I). These diselenides present GPx-mimetic properties, showing better antioxidant activity than the standard GPx-mimetic compounds, ebselen and diphenyl diselenide.

Real-Time Analysis of the Dynamic Foot Function: A Machine Learning and Finite Element Approach.

Finite element analysis (FEA) has been widely used to study foot biomechanics and pathological functions or effects of therapeutic solutions. However, development and analysis of such foot modeling is complex and time-consuming. The purpose of this study was therefore to propose a method coupling a FE foot model with a model order reduction (MOR) technique to provide real-time analysis of the dynamic foot function.

Gender Matters: Workplace Bullying, Gender, and Mental Health.

The aim of this study was to examine the role of gender in the process of workplace bullying. In particular, we examined how gender affects reported prevalence rates and health consequences of bullying. In addition, we pay particular attention to if the measurement method - self-labelling or behavioural experience methods - affects potential gender differences.

Targets' Social Relationships as Antecedents and Consequences of Workplace Bullying: A Social Network Perspective.

Research on workplace bullying has largely focused on individual and organizational factors that place individuals in a vulnerable position. Although theorists have highlighted social aspects of workplace bullying and its antecedents, the role of individuals' social relations with other members of their organization has rarely been examined empirically. Drawing on insights from social network research and research on social rejection, the purpose of this study was to examine the relationship between exposure to bullying and employees' informal social relationships (here: friendships; negative relationships) with other members of their organization.

Effort-Reward Imbalance: A Risk Factor for Exposure to Workplace Bullying.

Previous research shows that work environment factors are important antecedents of workplace bullying (WB), because of the stress they may induce. While previous studies have typically used Karasek's Job Demand-Control model or the Demands-Resources model, the present study investigates whether another important occupational stress model, that is the Effort-Reward Imbalance model, is also associated to WB. A survey study in 19 Belgian organizations ( = 5727) confirmed that employees experiencing an imbalance between efforts and reward were more likely to be targets of exposure to bullying.

Avalanches dynamics in reaction fronts in disordered flows.

We report on numerical studies of avalanches of an autocatalytic reaction front in a porous medium. The front propagation is controlled by an adverse flow resulting in upstream, static, or downstream regimes. In an earlier study focusing on front shape, we identified three different universality classes associated with this system by following the front dynamics experimentally and numerically.

Implementation of reflex loops in a biomechanical finite element model.

In the field of biomechanics, the offer of models which are more and more realistic requires to integrate a physiological response, in particular, the controlled muscle bracing and the reflexes. The following work aims to suggest a unique methodology which couples together a sensory and motor loop with a finite element model. Our method is applied to the study of the oscillation of the elbow in the case of a biceps brachial stretch reflex.

Experimental Evidence for Three Universality Classes for Reaction Fronts in Disordered Flows.

Self-sustained reaction fronts in a disordered medium subject to an external flow display self-affine roughening, pinning, and depinning transitions. We measure spatial and temporal fluctuations of the front in 1+1 dimensions, controlled by a single parameter, the mean flow velocity. Three distinct universality classes are observed, consistent with the Kardar-Parisi-Zhang (KPZ) class for fast advancing or receding fronts, the quenched KPZ class (positive-qKPZ) when the mean flow approximately cancels the reaction rate, and the negative-qKPZ class for slowly receding fronts.

History effects on nonwetting fluid residuals during desaturation flow through disordered porous media.

We investigate experimentally the sweeping of a nonwetting fluid by a wetting one in a quasi-two-dimensional porous medium consisting of random obstacles. We focus primarily on the resulting phase distributions and the residual nonwetting phase saturation as a function of the normalized wetting fluid flow rate-the capillary number Ca-at steady state. The wetting liquid is then flowing in the medium partially saturated by immobile nonwetting liquid blobs.

Risk factors of workplace bullying for men and women: the role of the psychosocial and physical work environment.

Workplace bullying has been shown to be a severe social stressor at work, resulting in high costs both for the individuals and organizations concerned. The aim of this study is to analyze risk factors in a large, nationally representative sample of Finnish employees (n = 4,392). The study makes three important contributions to the existing literature on workplace bullying: first, it demonstrates the role of the physical work environment alongside the psychosocial work environment - employees with a poor physical work environment are more likely than others to report having been subjected to or having observed bullying.

Low Reynolds number suspension gravity currents.

The extension of a gravity current in a lock-exchange problem, proceeds as square root of time in the viscous-buoyancy phase, where there is a balance between gravitational and viscous forces. In the presence of particles however, this scenario is drastically altered, because sedimentation reduces the motive gravitational force and introduces a finite distance and time at which the gravity current halts. We investigate the spreading of low Reynolds number suspension gravity currents using a novel approach based on the Lattice-Boltzmann (LB) method.

Autocatalytic reaction fronts inside a porous medium of glass spheres.

We analyze experimentally chemical wave propagation in the disordered flow field of a porous medium. The reaction fronts travel at a constant velocity that drastically depends on the mean flow direction and rate. The fronts may propagate either downstream and upstream but, surprisingly, they remain static over a range of flow rate values.

CHEMO-hydrodynamic coupling between forced advection in porous media and self-sustained chemical waves.

Autocatalytic reaction fronts between two reacting species in the absence of fluid flow, propagate as solitary waves. The coupling between autocatalytic reaction front and forced simple hydrodynamic flows leads to stationary fronts whose velocity and shape depend on the underlying flow field. We address the issue of the chemico-hydrodynamic coupling between forced advection in porous media and self-sustained chemical waves.

Drying in porous media with gravity-stabilized fronts: experimental results.

In a recent paper [Yiotis et al., Phys. Rev.

Analytical solutions of drying in porous media for gravity-stabilized fronts.

We develop a mathematical model for the drying of porous media in the presence of gravity. The model incorporates effects of corner flow through macroscopic liquid films that form in the cavities of pore walls, mass transfer by diffusion in the dry regions of the medium, external mass transfer over the surface, and the effect of gravity. We consider two different cases: when gravity opposes liquid flow in the corner films and leads to a stable percolation drying front, and when it acts in the opposite direction.

Numerical simulations of a buoyant autocatalytic reaction front in tilted Hele-Shaw cells.

We present a numerical analysis of solutal buoyancy effects on the shape and the velocity of autocatalytic reaction fronts, propagating in thin tilted rectangular channels. We use two-dimensional (2D) lattice Bathnagar-Gross-Krook (BGK) numerical simulations of gap-averaged equations for the flow and the concentration, namely a Stokes-Darcy equation coupled with an advection-diffusion-reaction equation. We do observe stationary-shaped fronts, spanning the width of the cell and propagating along the cell axis.

Measurement of the temperature profile of an exothermic autocatalytic reaction front.

Autocatalytic reactions may propagate as solitary waves, namely, at a constant front velocity and with a stationary concentration profile, resulting from a balance between molecular diffusion and chemical reaction. When the reaction is exothermic, a thermal wave is linked to the chemical front. As the thermal diffusivity is nearly two orders of magnitude larger than the molecular one, the temperature profile spreads over length scales (mm) two orders of magnitude larger than the concentration one.