102 research outputs found
Enforcement of Financial Reporting Regulation: Insights From New Data
We collect new data on the enforcement of reporting regulation. Our data is novel in two ways: we substantially expand the scope and the time-series coverage of existing datasets. It includes 32 enforcement variables measured from 2005 to 2022 in 29 European countries. Based on these data, we document two stylized facts. First, in terms of the level of enforcement, we observe contrasting patterns for enforcement “on the book” and “in practice”. While the former appears to have increased over recent years, the latter exhibits the opposite trend. Second, we observe that the variation in enforcement has decreased significantly over time. While there is a downward trend for both enforcement “on the books” and enforcement in “in practice”, the decrease is much more pronounced for the latter. These patterns have potential implications for our understanding of the recent evolution of the European enforcement system, which could provide potential lessons for other jurisdictions
Exfoliated Nanocomposites Based on Polyaniline and Tungsten Disulfide
Nanocomposite materials consisting of polyaniline (PANI) and exfoliated WS2 were synthesized. The WS2 was prepared by reacting tungstic acid with thiourea at 500°C under nitrogen flow. Samples were prepared with a WS2 content of 1, 5, 7.5, 10, 12.5, 15, 20, 37, and 64% by mass. An improvement in the electronic conductivity value of the PANI was observed through the incorporation of exfoliated WS2. The electronic conductivity of PANI-15%WS2 was 24.5 S/cm, an eightfold increase when compared to pure PANI. Powder X-ray diffraction (XRD), transmission electron microscopy (TEM) and electron paramagnetic resonance (EPR) provided evidence that the nanocomposites are in an exfoliated state. XRD and TEM showed that the nanocomposites were completely amorphous, suggesting lack of structural order in these materials, while their EPR signals were considerably narrower compared to pure PANI, indicating the formation of genuine exfoliated systems. Furthermore, our research showed that WS2 can be used as a filler to improve activation energy of decomposition of the polymer. By using the Ozawa method, we studied the decomposition kinetics for the nanocomposites, as well as for the pure polymer. The activation energy for the decomposition of pure PANI was found to be 131.2 kJ/mol. Increasing the amount of WS2 to 12.5% in the PANI increases the activation energy of decomposition to 165.4 kJ/mol, an enhancement of 34.2 kJ/mol over the pure polymer
Experimental Validation of a Numerical Forward Model for Tunnel Detection Using Cross-Borehole Radar
Thermal Transport in Micro- and Nanoscale Systems
Small-scale (micro-/nanoscale) heat transfer has broad and exciting range of applications. Heat transfer at small scale quite naturally is influenced – sometimes dramatically – with high surface area-to-volume ratios. This in effect means that heat transfer in small-scale devices and systems is influenced by surface treatment and surface morphology. Importantly, interfacial dynamic effects are at least non-negligible, and there is a strong potential to engineer the performance of such devices using the progress in micro- and nanomanufacturing technologies. With this motivation, the emphasis here is on heat conduction and convection. The chapter starts with a broad introduction to Boltzmann transport equation which captures the physics of small-scale heat transport, while also outlining the differences between small-scale transport and classical macroscale heat transport. Among applications, examples are thermoelectric and thermal interface materials where micro- and nanofabrication have led to impressive figure of merits and thermal management performance. Basic of phonon transport and its manipulation through nanostructuring materials are discussed in detail.
Small-scale single-phase convection and the crucial role it has played in developing the thermal management solutions for the next generation of electronics and energy-harvesting devices are discussed as the next topic. Features of microcooling platforms and physics of optimized thermal transport using microchannel manifold heat sinks are discussed in detail along with a discussion of how such systems also facilitate use of low-grade, waste heat from data centers and photovoltaic modules.
Phase change process and their control using surface micro-/nanostructure are discussed next. Among the feature considered, the first are microscale heat pipes where capillary effects play an important role. Next the role of nanostructures in controlling nucleation and mobility of the discrete phase in two-phase processes, such as boiling, condensation, and icing is explained in great detail. Special emphasis is placed on the limitations of current surface and device manufacture technologies while also outlining the potential ways to overcome them. Lastly, the chapter is concluded with a summary and perspective on future trends and, more importantly, the opportunities for new research and applications in this exciting field
Analyst information precision and small earnings surprises
This study proposes and tests an alternative to the extant earnings management explanation for zero and small positive earnings surprises (i.e., analyst forecast errors). We argue that analysts’ ability to strategically induce slight pessimism in earnings forecasts varies with the precision of their information. Accordingly, we predict that the probability that a firm reports a small positive instead of a small negative earnings surprise is negatively related to earnings forecast uncertainty, and we present evidence consistent with this prediction. Our findings have important implications for the earnings management interpretation of the asymmetry around zero in the frequency distribution of earnings surprises. We demonstrate how empirically controlling for earnings forecast uncertainty can materially change inferences in studies that employ the incidence of zero and small positive earnings surprises to categorize firms as suspected of managing earnings
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