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Mie computations are performed to evaluate light scattering on the virtual microstructures relevant to lithium disilicate glass internal crystallisation. The computations are expressed in the form of optical transmission (OT) patterns evolved on a scale of growing lithium disilicate crystals. Input data include the crystals number density, their size, the wavelength of the incident electromagnetic radiation, the indices of refraction of the lithium disilicate glassy and crystalline phases and the thickness of the virtual glass slab. In the computations, the spherical shape of crystals and their random distribution are assumed. The results reveal the quantitative effects of individual input data constants on the overall course of the computed OT patterns. They also relate the computed OT data magnitudes to the corresponding glass crystallinity (α). In addition, they point to singular combinations of the input data constants defining the conditions under which the OT data could potentially stand for the kinetically important α data. Finally, the results aid better recognition of some fundamental as well as practical properties of the optical thermal methods based on the optical transmission measurements.

Purpose The COVID-19 pandemic and subsequent efforts to contain it have started economic downturn that may even surpass the global financial crisis (GFC). The purpose of this study is to uncover the features of enterprises’ resilience during and after an external shock such as the GFC might be helpful in predicting the shock impact on enterprises and setting proper policy measures for the upcoming COVID-19 crisis. Design/methodology/approach The authors analysed the impact of the GFC on the entrepreneurial population in/of the Czech Republic using marginal effects method on a large random sample of 4,478 enterprises. In this analysis, the authors defined two groups of enterprises – “winners” and “losers” – based on the company’s dissolution and performance indicators. Findings The GFC struck the enterprise population asymmetrically in terms of the enterprises’ characteristics but also in terms of time. Micro and small size companies are the most vulnerable to external shocks such as the GFC. Technological level plays an important role in the recovery phase, especially in the case of manufacturing micro enterprises. Research limitations/implications Although there are differences between the GFC and the COVID-19 crisis, the GFC was the only comparable shock in modern history in its global nature, depth and unpredicted occurrence. It can be expected that the impact on enterprises can be partly similar. Practical implications Government support of micro size companies should be the priority in the upcoming COVID-19 crisis. Supporting the innovation and technology progress might accelerate the recovery phase after the crisis especially in micro companies as well. Originality/value This paper presents interesting insights into the impact of external shocks such as the GFC or COVID-19 on enterprises. It uncovers typical features of “winners” or “losers” of such shocks.

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