ACTL strong negation and its application to hybrid systems verification

Model checking procedures for verifying properties of hybrid dynamic systems are based on the construction of finite-state abstractions. If the property is not satisfied by the abstraction, the verification is inconclusive and the abstraction needs to be refined so that a less conservative model can be checked. If the hybrid system does not satisfy the property, this verify–refine procedure usually will not terminate. This paper introduces the concept of strong negation for ACTL formulas as an auxiliary condition that can be verified to obtain a conclusive negative verification result from a finite-state abstraction in certain cases. The concepts are illustrated with an example from automotive powertrain control.     

Application of modern approaches to the synthesis of biohydrogen from organic waste

Hydrogen production with the use of biological processes and renewable feedstock may be considered an economical and sustainable alternative fuel. The high calorific value and zero emission in the production of biohydrogen make it the best possible source for energy security and environmental sustainability. Solar energy, microorganisms, and feedstock such as organic waste and lignocellulosic biomasses of different feedstock are the only requirements of biohydrogen production along with specific environmental conditions for the growth of microorganisms. Hydrogen is also named as ‘fuel of the future’. This study presents different pathways of biohydrogen production. Because of breakthroughs in R&D, biohydrogen has been elevated to the status of a viable biofuel for the future. However, significant problems such as the cost of preprocessing, oxygen-hypersensitive enzymes, a lack of uniform light illumination for photobiological processes, and other expenses requiring intensification process limits are faced throughout the biohydrogen production process. Despite concerns regarding nanoparticle (NP) toxicity at higher concentrations, proper NP concentrations may improve hydrogen production dramatically by dissolving the substrates for bacterial hydrogen transformation. The data-driven Machine Learning (ML) model allows for quick response approximation for fermentative biohydrogen production while accounting for non-linear interactions between input variables. Scaling up biohydrogen production for future commercial-scale applications requires combining cost-benefit evaluations and life cycle effects with machine learning.     

Evaluation of the technological properties of rice starch modified by high hydrostatic pressure (HHP)

This aim of the study was to evaluate the technological properties of rice starch modified by high hydrostatic pressure (HHP). Black rice starch (BRS) was dispersed in 20% water and then HHP was applied at pressures of 200, 400 and 600 MPa for 30 min, where morphological, structural, functional and thermal parameters were evaluated. High pressure (BRS600) provided greater morphological damage, such as surface cavities and loss of crystallinity. The treatment HHP > 400 MPa the type of diffraction pattern was changed from type A to type V. The FT-IR spectra showed differences in intensity, especially for control, which revealed better defined peaks of greater intensity. The modified starch showed a greater affinity for water and oil absorption than the native starch as well as for milk absorption, exhibiting a higher binding capacity for the whole milk. HHP treatment is a fast and efficient non-thermal method to improve the technological properties of BRS.     

A new hydrogenation-coupling approach for supra-equilibrium conversion in a water–gas shift reaction: Simultaneous hydrogen generation and chemical storage

This work reports a practical system of hydrogenation-coupled water–gas shift reaction (HC-WGSR) for simultaneous hydrogen production and storage. The performance of the HC-WGSR system was predicted through thermodynamic simulation. The proof-of-concept tandem water–gas shift and propene hydrogenation strategy was successfully demonstrated using a bifunctional catalyst. The hydrogen produced from the WGSR was successfully stored in propane simultaneously, and the overall CO conversion of nearly 100% overcame the equilibrium limitation of the WGSR over a wide range of space velocities (3000 - 6000 h⁻¹) at 200 ^°C and 1 bar. This study demonstrated that the in situ removal/storage of H₂ using the hydrogenation-coupling approach is promising even in a CO₂-rich environment (20% CO₂). The new approach shall see a great opportunity in using organic hydrogen carriers, e.g., benzene, toluene, N-ethylcarbazole, to expand the industrial applications, underpinning the global supply chain for hydrogen energy.