Contemporary performance measurement systems: A review of their consequences and a framework for research

The main purpose of this paper is to develop a conceptual framework for understanding the literature on the consequences of contemporary performance measurement (CPM) systems and the theories that explain these consequences. The framework is based on an in-depth review of 76 empirical studies published in high-quality academic journals in the areas of accounting, operations, and strategy. The framework classifies the consequences of CPM into three categories: people's behaviour, organizational capabilities, and performance consequences. This paper discusses our current knowledge on the impact of CPM, highlighting inconsistencies and gaps as well as providing direction for future research

On the effect of the thermostat in non-equilibrium molecular dynamics simulations

The numerical investigation of the statics and dynamics of systems in nonequilibrium in general, and under shear flow in particular, has become more and more common. However, not all the numerical methods developed to simulate equilibrium systems can be successfully adapted to out-of-equilibrium cases. This is especially true for thermostats. Indeed, even though thermostats developed to work under equilibrium conditions sometimes display good agreement with rheology experiments, their performance rapidly degrades beyond weak dissipation and small shear rates. Here we focus on gauging the relative performances of three thermostats, Langevin, dissipative particle dynamics, and Bussi-Donadio-Parrinello under varying parameters and external conditions. We compare their effectiveness by looking at different observables and clearly demonstrate that choosing the right thermostat (and its parameters) requires a careful evaluation of, at least, temperature, density and velocity profiles. We also show that small modifications of the Langevin and DPD thermostats greatly enhance their performance in a wide range of parameters.Comment: 13 pages, 9 figure

Terahertz optically tunable dielectric metamaterials without microfabrication

We theoretically investigate the terahertz dielectric response of a semiconductor slab hosting an infrared photoinduced grating. The periodic structure is due to the charge carries photo-excited by the interference of two tilted infrared plane waves so that the grating depth and period can be tuned by modifying the beam intensities and incidence angles, respectively. In the case where the grating period is much smaller than the terahertz wavelength, we numerically evaluate the ordinary and extraordinary component of the effective permittivity tensor by resorting to electromagnetic full-wave simulation coupled to the dynamics of charge carries excited by infrared radiation. We show that the photoinduced metamaterial optical response can be tailored by varying the grating and it ranges from birefringent to hyperbolic to anisotropic negative dielectric without resorting to microfabrication.Comment: 3 pages, 2 figure

Extrinsic electromagnetic chirality in all-photodesigned one-dimensional THz metamaterials

We suggest that all-photodesigned metamaterials, sub-wavelength custom patterns of photo-excited carriers on a semiconductor, can display an exotic extrinsic electromagnetic chirality in terahertz (THz) frequency range. We consider a photo-induced pattern exhibiting 1D geometrical chirality, i.e. its mirror image can not be superposed onto itself by translations without rotations and, in the long wavelength limit, we evaluate its bianisotropic response. The photo-induced extrinsic chirality turns out to be fully reconfigurable by recasting the optical illumination which supports the photo-excited carriers. The all-photodesigning technique represents a feasible, easy and powerful method for achieving effective matter functionalization and, combined with the chiral asymmetry, it could be the platform for a new generation of reconfigurable devices for THz wave polarization manipulation.Comment: 11 page

Fracture locus of a CORTEN steel: Finite Element calibration based on experimental results

Abstract In order to protect low-alloy steel from corrosion in outdoor applications, it is common practice to use surface treatments e.g. painting or galvanization. The costs of these specific treatments and further maintenance can be reduced by exploiting weathering steel, the so-called CORTEN steel. The rust of this material forms a protective layer, adherent and self-regenerative, capable to stop the oxidation of the raw material. This characteristic, called self-passivation, is achieved by adding Cu, Cr and P in the alloy. Furthermore, its natural rust-color inspired architects, artists and civil engineers that start using CORTEN for bridges, building facades, artworks etc.. The harmony of CORTEN with natural environments boosts its application for guardrails (safety barriers) along the highway and alpine roads of the South-Tyrolean region. These components, in addition to aesthetic characteristics, have to fulfill safety requirements, especially during crash events. During an impact, the main goal of guardrails is to absorb and dissipate energy. Large deformations take place. Therefore, the most important mechanical characteristic for guardrails' materials is the tenacity related to the ductile behavior. However, despite CORTEN guardrails are homologated through experimental tests, in some specific conditions the passivation process could fail. Therefore, its energy absorption capabilities can be jeopardized by corrosion. In order to verify and/or optimize specific guardrails' geometries for safety applications, it is important to be able to model the ductile behavior and fracture locus of CORTEN within finite elements. The goal of this paper is to characterize the ductile behavior of CORTEN through experimental quasi-static tests with different geometries, thus different level of triaxiality. The test configurations were numerically reproduced, to retrieve the actual stress state, quantify the plastic strain at failure and calibrate a ductile damage model

Patterns of variability in early life traits of a Mediterranean coastal fish

Spawning dates and pelagic larval duration (PLD) are early life traits (ELT) crucial for understanding life cycles, properly assessing patterns of connectivity and gathering indications about patchiness or homogeneity of larval pools. Considering that little attention has been paid to spatial variability in these traits, we investigated variability of ELT from the analysis of otolith microstructure in the common two-banded sea bream Diplodus vulgaris. In the southwestern Adriatic Sea, along ~200 km of coast (∼1° in latitude, 41.2° to 40.2°N), variability of ELT was assessed at multiple spatial scales. Overall, PLD (ranging from 25 to 61 d) and spawning dates (October 2009 to February 2010) showed significant variability at small scales (i.e. <6 km), but not at larger scales. These outcomes suggest patchiness of the larval pool at small spatial scales. Multiple causal processes underlying the observed variability are discussed, along with the need to properly consider spatial variability in ELT, for example when delineating patterns of connectivity. Copyright © 2013 Inter-Research

Plants with less Chlorophyll: a global change perspective

The necessary reduction of greenhouse gas (GHG) emissions may lead in the future to an increase in solar irradiance (solar brightening). Anthropogenic aerosols (and their precursors) that cause solar dimming are in fact often co\u2010emitted with GHGs. While the reduction of GHG emissions is expected to slow down the ongoing increase in the greenhouse effect, an increased surface irradiance due to reduced atmospheric aerosol load might occur in the most populated areas of the earth. Increased irradiance may lead to air warming, favour the occurrence of heatwaves and increase the evaporative demand of the atmosphere. This is why effective and sustainable solar radiation management strategies to reflect more light back to space should be designed, tested and implemented together with GHG emission mitigation. Here we propose that new plants (crops, orchards and forests) with low\u2010chlorophyll (Chl) content may provide a realistic, sustainable and relatively simple solution to increase surface reflectance of large geographical areas via changes in surface albedo. This may finally offset all or part of the expected local solar brightening. While high\u2010Chl content provides substantial competitive advantages to plants growing in their natural environment, new plants with low\u2010Chl content may be successfully used in agriculture and silviculture and be as productive as the green wildtypes (or even more). The most appropriate strategies to obtain highly productive and highly reflective plants are discussed in this paper and their mitigation potential is examined together with the challenges associated with their introduction in agriculture