Publications by authors named "A B Nadykto"
Article Synopsis
- Tools with chamfered edges enhance cutting toughness and reduce wear during high-speed machining of hard materials like AISI 4340 steel, but they also create a "dead metal zone" (DMZ) that influences cutting efficiency.
- The study uses numerical simulation to investigate how factors like chamfer angle, cutting speed, and friction affect the formation and size of the DMZ, demonstrating that a smaller DMZ is associated with higher cutting speeds and lower friction.
- Findings indicate that machining forces increase with larger chamfer angles and higher friction coefficients, while they decrease with increased cutting speeds, providing insights for improving machining processes and surface quality on difficult-to-machine materials.
Propionamide (PA), an important pollutant emitted into the atmosphere from a variety of sources, is abundant in many areas worldwide, and could be involved in new particle formation (NPF). In this study, the enhancement of the HSO (SA)-based NPF by PA was evaluated through investigating the formation mechanism of (PA) (SA) ( = 0-3 and = 0-3) clusters using computational chemistry and kinetics modeling. Our study proved that the formation of all the PA-containing clusters is thermodynamically favorable.
View Article and Find Full Text PDFArticle Synopsis
- The study investigates how three common atmospheric bases (dimethylamine, methylamine, and ammonia) interact with HSO, a key precursor, and 14 organic acids found in the atmosphere, using advanced computational methods.
- It finds that these interactions generally create more stable mixed clusters compared to HSO alone, highlighting the importance of organic acids in the early stages of atmospheric nucleation.
- Additionally, while amines often outperform ammonia as stabilizers, there are situations where ammonia forms even more stable clusters, suggesting a need for deeper exploration of the role of organic acids in new particle formation.
By theoretical calculations, the gas-phase SO hydration reaction assisted by methylamine (MA) and dimethylamine (DMA) was investigated, and the potential contribution of the hydrated product to new particle formation (NPF) also was evaluated. The results show that the energy barrier for aliphatic amines (MA and DMA) assisted SO hydration reaction is lower than the corresponding that of water and ammonia assisted SO hydration. In these hydration reactions, nearly barrierless reaction (only a barrier of 0.
View Article and Find Full Text PDFArticle Synopsis
- The study investigates the molecular characteristics of Dissolved Organic Nitrogen (DON) from wet deposition in the Erhai basin using advanced mass spectrometry techniques.
- It identifies that about 18.3% of the wet deposition is DON, primarily consisting of single nitrogen atom species, with a typical molecular mass between 200-400 Da.
- The findings suggest a low degree of aromaticity and humification in the samples, highlighting the effectiveness of combining multiple analytical methods for a deeper understanding of DON structure and composition.