Percolation and jamming phenomena are investigated for anisotropic sequential deposition of dimers (particles occupying two adjacent adsorption sites) on a square lattice. The influence of dimer alignment on the electrical conductivity was examined. The percolation threshold for deposition of dimers was lower than for deposition of monomers. Nevertheless, the problem belongs to the universality class of random percolation. The lowest percolation threshold (pc = 0.562) was observed for isotropic orientation of dimers. It was higher (pc = 0.586) in the case of dimers aligned strictly along one direction. The state of dimer orientation influenced the concentration dependence of electrical conductivity. The proposed model seems to be useful for description of the percolating properties of anisotropic conductors.PACS. 64.60.Ak Renormalization-group, fractal, and percolation studies of phase transitions -64.60.Cn Order-disorder transformations; statistical mechanics of model systems

We consider site percolation of dimers ("neadles") on simple cubic lattice. The percolation threshold is estimated as p perc c ≈ 0.2555 ± 0.0001. The jamming threshold is estimated as p jamm c = 0.799 ± 0.002. PACS. 64.60.Ak Renormalization-group, fractal, and percolation studies of phase transitions -05.10.-a Computational methods in statistical physics and nonlinear dynamics -81.20.Fw Sol-gel processing, precipitation

This study explores the firm-level relationship between earnings quality and investment efficiency. Higher quality of reported results has the capacity to positively impact the efficiency of company's investment levels by over-and underinvestment reduction. The research is carried out on the sample of 7546 companies from Eastern Europe for the period 2010-2015. Eastern European countries have a unique institutional and business environment that is relevant to the purpose of this paper. We divide the sample into 2 fundamentally different economic sectors -industrial and retail -and test the significance of each factor in the main relationship. We also examine the factor of the firm's ownership form by comparing earnings quality with investment efficiency values between public and private companies. Our main results show that a higher earnings quality mitigates both overinvestment and underinvestment issues. The relationship between earnings quality and underinvestment turns out to be stronger in the industrial sector. As for the comparison of public and private firms, public companies on average demonstrate a higher earnings quality and lower overinvestment issues.

This study explores the impact of a company’s financial flexibility on the effectiveness of its investments.The number of companies that have financial flexibility was calculated with the application of thespare debt capacity method. The research identifies the impact of financial flexibility on investment activity and on the level of suboptimal investments. The data from 1,736 companies in theAsian region, during the 2005-2015time period, are presented. The Asian region has unique institutional, economic and commercial environments that present a great basis for this paper. The results of the research reveal that financially flexible companies spend more on their investment expenditure and conduct more effective investment policiesby reducing the level of over- and underinvestment. Financial flexibility helps companies to make effective investments during a crisis period, but the difference in the flexibility between developed and developing countries and between large and small companies was not observed.

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