Search

Imaging the internal architecture of fast-vibrating structures at micrometer scale and kilohertz frequencies poses great challenges for numerous applications, including the study of biological oscillators, mechanical testing of materials, and process engineering. Over the past decade, X-ray microtomography with retrospective gating has shown very promising advances in meeting these challenges. However, breakthroughs are still expected in acquisition and reconstruction procedures to keep improving the spatiotemporal resolution, and study the mechanics of fast-vibrating multiscale structures. Thereby, this works aims to improve this imaging technique by minimising streaking and motion blur artefacts through the optimisation of experimental parameters. For that purpose, we have coupled a numerical approach relying on tomography simulation with vibrating particles with known and ideal 3D geometry (micro-spheres or fibres) with experimental campaigns. These were carried out on soft composites, imaged in synchrotron X-ray beamlines while oscillating up to 400 Hz, thanks to a custom-developed vibromechanical device. This approach yields homogeneous angular sampling of projections and gives reliable predictions of image quality degradation due to motion blur. By overcoming several technical and scientific barriers limiting the feasibility and reproducibility of such investigations, we provide guidelines to enhance gated-CT 4D imaging for the analysis of heterogeneous, high-frequency oscillating materials. [ABSTRACT FROM AUTHOR]

Modelling real processes often results in several suitable models. In order to be able to distinguish, or discriminate, which model best represents a phenomenon, one is interested, e.g., in so-called T-optimal designs. These consist of the (design) points from a generally continuous design space at which the models deviate most from each other under the condition that they are best fitted to those points. Thus, the T-criterion represents a bi-level optimization problem, which can be transferred into a semi-infinite one but whose solution is very unstable or time consuming for non-linear models and non-convex lower- and upper-level problems. If one considers only a finite number of possible design points, a numerically well tractable linear semi-infinite optimization problem arises. Since this is only an approximation of the original model discrimination problem, we propose an algorithm which alternately and adaptively refines discretizations of the parameter as well as of the design space and, thus, solves a sequence of linear semi-infinite programs. We prove convergence of our method and its subroutine and show on the basis of discrimination tasks from process engineering that our approach is stable and can outperform the known methods. [ABSTRACT FROM AUTHOR]

Plastic waste is an environmental challenge, but also presents a biotechnological opportunity as a unique carbon substrate. With modern biotechnological tools, it is possible to enable both recycling and upcycling. To realize a plastics bioeconomy, significant intrinsic barriers must be overcome using a combination of enzyme, strain, and process engineering. This article highlights advances, challenges, and opportunities for a variety of common plastics. The way we generate and treat plastic waste is a key consideration in the transition from a take-make-waste model to a truly circular economy. Here, authors discuss their views on how biotechnology could contribute to solving the plastic problem, and the barriers we need to overcome to make such approaches a reality. [ABSTRACT FROM AUTHOR]

Chemical leaching of coals would be required to produce cleaner coals for some special applications where physical beneficiation may not be effective enough. This would also help in recovering Li and rare earth metals besides in the sequestration of CO2. About 20 Indian coals having complexly distributed moderate to high ash contents were sequentially treated with various alkali–acid such as NaOH-HCl, HF, HCl, HCl-HF, and NaOH-HCl-HF leaching. This aimed to establish and design the best stepwise sequential process for the highest degree of demineralisation through a chemical leaching process. Kinetics and process intensification studies were carried out. More than 80% demineralisation of Madhaipur and Neemcha coals was observed using the best sequential treatment designed presently. The repeated stepwise treatment of the alkali and the acid was also studied, which was found to significantly enhance the degree of demineralisation of coals. The integrated process of alkali–acid leaching followed by solvent extraction (Organo-refining) and vice versa of the treated coal was also studied for producing cleaner coals. [ABSTRACT FROM AUTHOR]

Blue denim, a billion-dollar industry, is currently dyed with indigo in an unsustainable process requiring harsh reducing and alkaline chemicals. Forming indigo directly in the yarn through indican (indoxyl-β-glucoside) is a promising alternative route with mild conditions. Indican eliminates the requirement for reducing agent while still ending as indigo, the only known molecule yielding the unique hue of blue denim. However, a bulk source of indican is missing. Here, we employ enzyme and process engineering guided by techno-economic analyses to develop an economically viable drop-in indican synthesis technology. Rational engineering of PtUGT1, a glycosyltransferase from the indigo plant, alleviated the severe substrate inactivation observed with the wildtype enzyme at the titers needed for bulk production. We further describe a mild, light-driven dyeing process. Finally, we conduct techno-economic, social sustainability, and comparative life-cycle assessments. These indicate that the presented technologies have the potential to significantly reduce environmental impacts from blue denim dyeing with only a modest cost increase. Conventional blue denim dyeing has both environmental and health-related consequences. Here, Bidart et al. use enzyme engineering to develop a viable method for the bulk production of indican and demonstrate dying processes which could significantly reduce the negative consequences of this billion-dollar industry. [ABSTRACT FROM AUTHOR]

This article discusses the role of hydrogen in the transition away from carbon-based energy sources. It highlights the importance of process systems engineering (PSE) in guiding the operation and control of the industrial metabolism during this transition. The article emphasizes the need for engineering solutions that consider factors such as energy efficiency, storage alternatives, and the transportability and safety of hydrogen as an energy carrier. It also explores the potential of hydrogen in various sectors, such as oil refining, ammonia synthesis, and transportation. The article concludes by discussing the challenges and opportunities associated with the energy transition and the importance of technology-driven policies in evaluating energy efficiency and affordability. [Extracted from the article]

This document is a correction notice for an article titled "Evaluation of physical parameters and spectral characterization of the quality of soaps containing by-products from the food industry." The original article was published in Scientific Reports and can be found online. The correction addresses the omission of the Funding section in the original version of the article. The corrected version now includes information about the funding received from the Ministry of Education and Science in Poland. The authors of the article are Patrycja Łusiak, Renata Różyło, Jacek Mazur, Paweł Sobczak, and Arkadiusz Matwijczuk. [Extracted from the article]