Heaping, Secondary Flows and Broken Symmetry in Flows of Elongated Granular Particles

In this paper we report experiments where we shear granular rods in split-bottom geometries, and find that a significant heap of height of least 40% of the filling height can form at the particle surface. We show that heaping is caused by a significant secondary flow, absent for spherical particles. Flow reversal transiently reverses the secondary flow, leading to a quick collapse and slower regeneration of the heap. We present a symmetry argument and experimental data that show that the generation of the secondary flow is driven by a misalignment of the mean particle orientation with the streamlines of the flow. This general mechanism is expected to be important in all flows of sufficiently anisometric grains.Comment: Accepted for Soft Matte

Testing of a Radiant Wall Cooling System with Pipes Coupled to Aerated Blocks

Thermal output, surface temperatures, and supply and return water temperature were measured for a wall cooling system involving pipe attached to a wall section made of thermally insulating blocks. The experiment was performed for warm climatic conditions typical of, e.g., summer in Central and Northern Europe. The outdoor environment was simulated by a climatic chamber while the indoor climate was simulated by attaching a hotbox to the wall surface. The sensitivity of thermal output to several design parameters was investigated by 2D numerical simulations. The measurements showed a fast thermal response of the wall system. The cooling output was 38.3 W per m2 of the cooling area which equalled about 4.8 W/m2 per 1 K temperature difference between water and hotbox. The lowest surface temperature of 19.6 °C was measured at the pipe. Thus, the cooling output could be enhanced by reducing the surface temperature closer to the dew point temperature. The temperature of water in the pipe was very close to the surface temperature. It was illustrated how this characteristic of the wall cooling system tested positively affects the efficiency and cooling capacity of an air-to-water heat pump

Strategy abundance in 2x2 games for arbitrary mutation rates

We study evolutionary game dynamics in a well-mixed populations of finite size, N. A well-mixed population means that any two individuals are equally likely to interact. In particular we consider the average abundances of two strategies, A and B, under mutation and selection. The game dynamical interaction between the two strategies is given by the 2x2 payoff matrix [(a,b), (c,d)]. It has previously been shown that A is more abundant than B, if (N-2)a+Nb>Nc+(N-2)d. This result has been derived for particular stochastic processes that operate either in the limit of asymptotically small mutation rates or in the limit of weak selection. Here we show that this result holds in fact for a wide class of stochastic birth-death processes for arbitrary mutation rate and for any intensity of selection.Comment: version 2 is the final published version that contains minor changes in response to referee comment

Framing gender equality in the European Union and its current and future Member States. Deliverable No. 61: Final LARG Report

Published versio

Munkaerő-megtartási stratégiák és kihívások élelmiszerfeldolgozóipari példán keresztül

Based on the peculiarities of today’s labor market, we can see quite a lot of research papers about labor shortage, labor force fluctuaction and employee retention. Most of these papers are based on the aspects of the employer. This research focuses on analyzing and evaluating the most commonly used labor retention techniques used by companies. The publishers were trying to find out which factors were the most important in earning and employee’s loyalty, to strenghten a company’s employee retention. Based on the research, we can identify having a steady job as one of the most important factors, and that (material) benefits are not as important, as they used to be. To lower fluctuation and to strenghten labor retention, an important first step is to create an adequate workplace atmosphere, in which the main role falls to the leadership, and to affiliative coworkers. The fact that different measures will have different results can also be determined. There is a difference between the preferences of different labor groups, which makes the assessment of every worker’s individual need a company’s necessity, in hope of effective labor retainment