Nitrides as ammonia synthesis catalysts and as potential nitrogen transfer reagents

In this article, an overview of the application of selected metal nitrides as ammonia synthesis catalysts is presented. The potential development of some systems into nitrogen transfer reagents is also described

The impact of key audit matters and firm performance on investor reaction: An empirical study on the Philippine stock exchange index from 2016 to 2019

As the number of investors and traders engaging in stock market activities in the Philippine Stock Market increase due to the ease and accessibility that online trading platforms have provided, establishing which financial or nonfinancial information that can be useful in making investment decisions has become necessary. As such, the study aims to determine the impact that the disclosure of key audit matters and the firm performance of companies have on investor reaction. Financial statements and audit reports of the companies listed in the Philippine Stock Exchange Index during the years 2016 to 2019 were used in the gathering of data to be used in the study. The gathered data were then statistically analyzed using descriptive statistics, panel data regression, and classic assumption tests. Results revealed that both Key Audit Matters and Firm Performance, as measured by Financial Ratios, did not significantly impact investor reaction. This can be attributed to the behavior of investors towards internal and external factors influencing the market, thus making stock prices more dynamic. Keywords: Key Audit Matters, Firm Performance, Financial Ratios, Investor Reaction, Cumulative Abnormal Retur

Characterization of particle emissions from consumer fused deposition modeling 3D printers

<p>Particle emissions from multiple fused deposition modeling consumer 3D printers were systematically quantified utilizing an established emission testing protocol (Blue Angel) to allow quantitative exposure assessments for printers operating in different environments. The data are consistent with particle generation from volatilization of the polymer filament as it is heated by the extruder. Typically, as printing begins, a burst of new particle formation leads to the smallest sizes and maximum number concentrations produced throughout the print job. For acrylonitrile butadiene styrene (ABS) filaments, instantaneous concentrations were up to 10⁶ #/cm³ with mean particle sizes of 20 to 40 nm when measured in a well mixed 1 m³ chamber with 1 air change per hour. Particles are continuously formed during printing and the size distribution evolves consistent with vapor condensation and particle coagulation. Particles emitted per mass of filament consumed (particle yield) varied widely due to factors including printer brand, and type and brand of filament. Higher extruder temperatures result in larger emissions. For filament materials tested, average particle number yields ranged from 7.3 × 10⁸ to 5.2 × 10¹⁰ g⁻¹ (approximately 0.65 to 24 ppm), with trace additives apparently driving the large variations. Nanoparticles (diameters less than 100 nm) dominate number distributions, whereas diameters in the range of 200 to 500 nm contribute most to estimated mass. Because 3D printers are often used in public spaces and personal residences, the general public and particularly susceptible populations, such as children, can be exposed to high concentrations of non-engineered nanoparticles of potential toxicity.</p> <p>Copyright © 2017 American Association for Aerosol Research</p> <p><a href="http://www.tandfonline.com/pb-assets/tandf/Migrated/UAST1_VideoAbstract_Transcript.pdf" target="_blank">Read the transcript</a></p> <p><a href="https://vimeo.com/266868807" target="_blank">Watch the video on Vimeo</a></p