Frequent CEO Turnover and Firm Performance: The Resilience Effect of Workforce Diversity

© 2020, Springer Nature B.V. CEO turnover (or succession) is a critical event in an organization that influences organizational processes and performance. The objective of this study is to investigate whether workforce diversity (i.e., age, gender, and education-level diversity) might have a resilience effect on firm performance under the frequency of CEO turnover. Based on a sample of 409 Korean firms from 2010 to 2015, our results show that firms with more frequent CEO turnover have a lower firm performance. However, firms with more gender and education-level diversity could buffer the disruptive effect of frequent CEO turnover on firm performance to offer a benefit to the organization. Our theory and findings suggest that effectively managing diverse workforce can be a resilience factor in an uncertain organizational environment because diverse workforce has complementary skills and behaviors that can cope better with uncertainty and signals social inclusion of an organization, thus fostering a long-term exchange relationship. These findings contribute to the literature on CEO turnover (or succession) and diversity

Synthesis, Structures, and Optical Properties of Ruthenium(II) Complexes of the Tris(1-pyrazolyl)methane Ligand

Four new complex salts [Ru^(II)Cl(Tpm)(L^A)_2][PF_6]_n [Tpm = tris(1-pyrazolyl)methane; n = 1, L^A = pyridine (py) 1 or ethyl isonicotinate (EIN) 2; n = 3, L^A = N-methyl-4,4′-bipyridinium (MeQ^+) 3 or N-phenyl-4,4′-bipyridinium (PhQ^+) 4] have been prepared and characterized. Electronic absorption spectra show intense d → π^* metal-to-ligand charge-transfer (MLCT) absorption bands, while cyclic voltammetry reveals a reversible Ru^(III/II) wave, accompanied by quasireversible or irreversible L^A-based reductions for all except 1. Single crystal X-ray structures have been obtained for 1•Me_2CO, 2, and 3•Me_2CO. For 2–4, molecular first hyperpolarizabilities β have been measured in acetonitrile solutions via the hyper-Rayleigh scattering (HRS) technique at 800 nm. Stark (electroabsorption) spectroscopic studies on the MLCT bands in frozen butyronitrile allow the indirect estimation of static first hyperpolarizabilities β_0. The various physical data obtained for 3 and 4 are compared with those reported previously for related cis-{Ru^(II)(NH_3)_4}^(2+) species [Coe, B. J. et al. J. Am. Chem. Soc. 2005, 127, 4845]. TD-DFT calculations on the complexes in 1–4 confirm that their lowest energy absorption bands are primarily Ru^(II) → L^A MLCT in character, while Ru^(II) → Tpm MLCT transitions are predicted at higher energies. DFT agrees with the Stark, but not the HRS measurements, in showing that β_0 increases with the electron-accepting strength of L^A. The 2D nature of the chromophores is evidenced by dominant β_(xxy) tensor components

Enabling flexible CHP operation for grid support by exploiting the DHN thermal inertia

As a result of the increased penetration of intermittent renewable energy sources, Combined Heat and Power (CHP) units are being looked upon as one of the sources that might provide for the ever growing need for electrical flexibility. However, CHP units are often considered as must-run units on the grid for their main purpose is generally to cover the heat demand of an adjoining District Heating Network (DHN). This paper demonstrates how a CHP–DHN system may be used as a frequency reserve without excessively compromising the lifetime of the CHP, using either a specific storage tank or the DHN's thermal inertia in order to compensate for the resulting heat imbalance. In the latter case, it is shown that a buffer tank, although smaller than a specific Thermal Energy Storage (TES), is required due to restrictions for acceptable DHN temperature gradients. In both approaches, the size of the tank has been mapped out considering frequency reserve's duration and capacity. The results show that a simplistic static model of the DHN is sufficient for the design of a specific TES, while a detailed dynamic simulation is required when the DHN is used as storage, to prevent overestimating the flexibility of the CHP–DHN system. This research could be used to assess the potential for improving CHP–DHN systems flexibility, using them as frequency reserves, and to design the required storage or buffer tanks.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Trajectory driven multidisciplinary design optimization of a sub-orbital spaceplane using non-stationary Gaussian process

This paper presents the multidisciplinary optimization of an aircraft carried sub-orbital spaceplane. The optimization process focused on three disciplines: the aerodynamics, the structure and the trajectory. The optimization of the spaceplane geometry was coupled with the optimization of its trajectory. The structural weight was estimated using empirical formulas. The trajectory was optimized using a pseudo-spectral approach with an automated mesh refinement that allowed for increasing the sparsity of the Jacobian of the constraints. The aerodynamics of the spaceplane was computed using an Euler code and the results were used to create a surrogate model based on a non-stationary Gaussian process procedure that was specially developed for this study.Aerodynamics, Wind Energy & PropulsionAerospace Engineerin