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Although organometallic porous polymer networks are recognized as promising heterogeneous catalysts, the relationship between ligand/monomer geometry and network parameters is usually not well understood due to the lack of atom-resolved characterization methods for the amorphous network matrix. In this work, a series of copper(II) salen-type metal complexes was synthesized, using trans- and cis-1,2-diaminocyclohexane segments, and thoroughly characterized by single-crystal X-ray diffraction and solution- and solid-state NMR spectroscopy. Terminal ethynyl groups of the complexes were then transformed into polyacetylene chains by coordination chain-growth homopolymerization, resulting in highly porous (458–655 m2 g−1) organometallic polymer networks with a copper(II) ion content of about 12 wt%. The presence of paramagnetic copper(II) moieties in these complexes and respective polymer networks required the application of tailored NMR techniques, which together with X-ray crystallography and DFT calculations of the paramagnetic NMR shifts made it possible to investigate the differences in the complex geometry in liquid, powder and crystalline form and compare it with the complex geometry in polymer networks. All prepared organometallic polymer networks were also tested as heterogeneous catalysts for styrene oxidation with uncommonly high substrate conversions and compared with their low-molecular-weight analogues. The high reusability of such heterogeneous polymer-based catalysts was also proven. [ABSTRACT FROM AUTHOR]

This paper deals with the effects of education-job (mis)match on the earnings of higher education graduates in the context of higher education expansion and different phases of the economic cycle in the Czech Republic in 2006–2018. It aims to contribute to knowledge about the effects of education-job (mis)match on earnings in two ways. First, it concentrates on both the vertical and the horizontal dimensions of education-job (mis)match. Second, it considers the effects of contextual variables: the share of graduates in the population and the unemployment rate of graduates. The paper is based on assumptions derived from assignment theory. The authors use data of graduates’ self-evaluation collected in national and international graduate surveys – REFLEX, REFLEX 2010, REFLEX 2013, and Absolvent 2018. The data for contextual variables come from Eurostat and the Czech Statistical Office. The analyses focus on graduates four to five years after graduation. They are examined both as a whole and in groups based on the field of study using the method of weighted least squares. Overeducation usually has significant negative effects on earnings. Horizontal match effects are contradictory. The education-job (mis)match effects are relatively small in comparison with other factors. The role of contextual variables is mostly predictable, however, some exceptions uncover specifics of the labour market in the Czech Republic. There are important differences among groups of graduates in different fields of study.

The article concentrates on the impact of selected aspects of governance - the level of autonomy and the involvement of stakeholders in the internal governance of a university - on the research performance of universities measured by indicators of international university rankings in cross-country comparisons. The analyses are geographically situated in Europe. They follow two paths which are from the theoretical point of view based on the concepts of the principal-agent problem and stakeholder theory. Using linear regression, the author identifies statistically significant aspects of governance and compares them with results of previous studies. The findings serve as a basis for a discussion regarding how to create appropriate conditions for universities in order to improve their prospects for international success in research. The limitations of the results relating to the data, methodology and their application in the European context are discussed and general recommendations are formulated.

The aim of this paper is to describe the methodology of modelling fluid flow and heat transfer tasks for testing electronic motion sensors, especially PIR (passive infra-red) motion sensors. The motion sensor measures changes in electromagnetic radiation in the infrared range caused by the movement of warmer objects compared to its surroundings. Distortion of the perception of the environment can lead to false alarms or insensitivity of the detector. PIR motion sensors should be designed and located to minimize heating of the lens by ambient air. The sensor may be exposed to conditions not specified in the basic standards. The practical part of this article deals with a non-standard test. A single-phase transient simulation in a specific test cabinet for two specific motion sensor models was performed using the computational fluid dynamics (CFD) method. The aim of these simulations was to evaluate the effect of hot flowing air on the lens and to compare the designs of both models. Comparison and analysis of the results showed that the test configuration does not guarantee a defined flow at the outlet of the pipeline, so a new configuration was designed.

Two series of hyper-cross-linked microporous polyacetylene networks containing either -[CH=C(CH=O)]- or -[CH=C(CH2OH)]- monomeric units are reported. Networks are prepared by chain-growth copolymerization of acetal-protected propargyl aldehyde and acetal-protected propargyl alcohol with a 1,3,5-triethynylbenzene cross-linker followed by hydrolytic deprotection/detemplating. Deprotection not only liberates reactive CH=O and CH2OH groups in the networks but also modifies the texture of the networks towards higher microporosity and higher specific surface area. The final networks with CH=O and CH2OH groups attached directly to the polyene main chains of the networks have a specific surface area from 400 to 800 m2/g and contain functional groups in a high amount, up to 9.6 mmol/g. The CH=O and CH2OH groups in the networks serve as active centres for the reversible capture of CO2 and water vapour. The water vapour capture capacities of the networks (up to 445 mg/g at 297 K) are among the highest values reported for porous polymers, making these materials promising for cyclic water harvesting from the air. Covalent modification of the networks with (R)-(+)-3-aminopyrrolidine and (S)-(+)-2-methylbutyric acid enables the preparation of porous chiral networks and shows networks with CH=O and CH2OH groups as reactive supports suitable for the anchoring of various functional molecules. [ABSTRACT FROM AUTHOR]

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Several ponds were built in the vicinity of the city of Zábřeh (Czech Republic) during the 15th century, all of which disappeared over time, leaving only one (Oborník) that survived to the present day. Currently, the only proof of the existence of these ponds in the landscape are the dams, preserved in varying degrees of quality. Another potential proof of the presence of ponds is pond sediment, the existence and extent of which are the subject of this text. The abandoned Leštinský pond, located to the east of Zábřeh, was chosen for this research. This pond was only captured on the maps from the 1st military mapping, it is no longer depicted on newer maps. Its presence is indicated by a partially preserved dam, which is not very distinct in the landscape but is visible in Lidar images. The pond sediments were investigated through a combination of geological survey (shallow boreholes) and geophysical prospecting (electrical resistivity tomography and ground penetrating radar). A total of 5 drill cores were taken on which magnetic susceptibility, grain size, geochemical composition and spectral reflectance were measured. Four facies were identified based on the lithology and the used analyses. These facies are interpreted as a recent soil (facie P1), pond sediment (facie R) and buried alluvial soil developed on fluvial sediments (facie P2) and coarse-grained sands (facie F). The data from geophysical survey correlates with boreholes lithology and extends this information spacially. Above all, ground penetrating radar (GPR) of facie RF3, interpreted as the base of pond sediments, can be easily observed in GPR profiles. The obtained results provide information about the presence and thickness of the pond sediment. Pond sediment was captured in boreholes at thickness ranging from 12 to 38 cm, with no internal pond sediment stratigraphy being observed. The probable reason for such a limited sediment thickness could be the initially shallow depth of the pond or the pond's summering process ("letnění"), during which no water was present in the pond and the removal of the pond sediment occurred in regular cycles. [ABSTRACT FROM AUTHOR]