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  • Author: Octavian Ionescu x
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Abstract

We identified a notable lack of academic literature on the issue of third-country auditors and the main contribution of our article is to address this gap. This research builds on adjacent audit oversight and capital markets literature and we extend this literature by providing evidence on third-country auditors. Specifically, we test the relationship between market capitalization and number of foreign IPOs of listed companies in representative EU countries (on one hand) and the existence of third-country auditors in those respective countries (on the other hand). Our research was performed in the second half of 2018 and is based on the latest data available. We have found that there are about 200 third-country auditors present in the public registers of audit oversight bodies in 11 EU countries. According to our network analysis, only European countries with a developed capital market have attracted third-country auditors. Most of the relationships of these developed EU capital markets are nurtured with non-EU capital markets that are at the same level of development (e.g. USA, Switzerland, Canada, Israel, and Australia). Our research hypotheses were validated: (1) the higher the market capitalization of a EU country, the higher the likelihood for the registration of third-country auditors; (2) the higher the number of foreign IPOs relative to the total IPOs on the stock exchange market, the higher the likelihood for the registration of third-country auditors.

Abstract

Bulk nanocrystalline graphite has been investigated as a possible candidate for piezoresistive sensors. The thin films were grown using capacitively coupled plasma enhanced chemical vapor deposition and a technological workflow for the transfer of the active material onto flexible substrates was established in order to use the material as a piezoresitive element. Preliminary electrical measurements under mechanical strain were performed in order to test the piezoresistive response of the material and promising GF values of 50 − 250 at 1% strain were obtained.

Abstract

The paper presents the morphological, structural and compositional properties of the sonochemically prepared ZnO-1.4wt% Graphene (Z-G) nanocomposites as a function of pH value of suspension varying from 8.5 to 14 and thermal annealing at 450°C in nitrogen or air ambient. The SEM analysis of the Z-G hybrids dried at 150°C in air has shown a nano-flower like nanostructure for a pH value of 14. The XRD analysis of dried Z-G hybrids revealed a crystallite size increase from 3.5 nm to 18.4 nm with pH increase, and this result was explained in terms of colloids zeta potential evolution with pH value. The Raman and EDS spectroscopy have shown a split of the G band (1575 cm−1) of graphene into two bands (1575 cm−1 and 1605 cm−1), an increased height of D (1323 cm−1) band, and an additional amount of carbon due to CO2 absorption from the air, respectively. The carbon incorporation increased with the decrease of pH, and was associated with a hydrozincite phase, Zn5(CO3)2(OH)6. The formation of dried Z-G nanocomposite was clearly demonstrated only at a pH value equal to 14, where two ZnO Raman active bands at 314.9 cm−1 and 428.2 cm−1 appeared. This result may indicate the sensitivity of the Raman spectroscopy to the nanoflower-like nanostructure of dried Z-G hybrids prepared at pH=14. The thermal treatment of Z-G hybrids in N 2 at 450°C has increased the number of ZnO Raman bands as a function of pH value, it has decreased the amount of additional carbon by conversion of hydrozincite to ZnO and preserved the graphene profile. The thermal treatment in air at 450°C has increased the crystalline symmetry and stoichiometry of the ZnO as revealed by high and narrow Raman band from 99 cm−1 specific to Zn optical phonons, but it has severely affected the graphene profile in the Z-G hybrid, due to combustion of graphene in oxygen from the ambient.