Regulation of the luminescence mechanism of two-dimensional tin halide perovskites

Two-dimensional (2D) Sn-based perovskites are a kind of non-toxic environment-friendly luminescent material. However, the research on the luminescence mechanism of this type of perovskite is still very controversial, which greatly limits the further improvement and application of the luminescence performance. At present, the focus of controversy is defects and phonon scattering rates. In this work, we combine the organic cation control engineering with temperature-dependent transient absorption spectroscopy to systematically study the interband exciton relaxation pathways in layered A2SnI4 (A = PEA+, BA+, HA+, and OA+) structures. It is revealed that exciton-phonon scattering and exciton-defect scattering have different effects on exciton relaxation. Our study further confirms that the deformation potential scattering by charged defects, not by the non-polar optical phonons, dominates the excitons interband relaxation, which is largely different from the Pb-based perovskites. These results enhance the understanding of the origin of the non-radiative pathway in Sn-based perovskite materials.

Control of the COVID-19 System by Vaccination Using a New Control Engineering Technique

In this work, a novel control engineering method is proposed to achieve a control strategy by vaccination for the COVID-19 epidemic. A proper mathematical model with vaccination control is developed for the COVID-19 system based on the Susceptible-Exposed-Infectious-Recovered (SEIR) epidemiological model after conducting some analyses and assumptions that reflect the COVID-19 features. Then, the proposed control law is designed using the feedback linearization approach and the H-infinity control framework. In addition, a model reference control is incorporated to ensure that satisfactory time responses are obtained. The Black Hole Optimization (BHO) technique is used to attain the optimality of the proposed control method. Following that, the reported statistics and vaccination plan of the Lombardy region of Italy are utilized to assess the effectiveness of the proposed control law. Ultimately, the simulation results illustrate that the proposed control law can effectively control the COVID-19 system and correctly perform the vaccination plan by tackling the system’s nonlinearity and uncertainty and realizing elegant asymptotic tracking characteristics with reasonable control effort.

Control education in the software age

According to a commonplace saying, software is eating the world. Is software also eating control engineering? Software is currently transforming many industries including but not limited to automotive aiming at automated mobility services, agriculture moving to Agriculture 4.0, and factory automation with Industry 4.0. Software is simultaneously a flexible and universal functions enabler, and a driver of engineering complexity. At times, it seems that control engineers and software engineers are not understanding each other well enough. This article discusses two key engineering domains adjacent to control, systems and software engineering, covering engineering practice, design data exchange, and education. Finally, it suggests an extension to academic control curricula help to make control graduates even better team players.

Controlling forever love

A stable and rewarding love relationship is considered a key ingredient for happiness in Western culture. Building a successful long-term relationship can be viewed as a control engineering problem, where the control variable is the effort to be made to keep the relationship alive and well. We introduce a new mathematical model for the effort control problem of a couple in love who wants to stay together forever. The problem can be naturally formulated as a dynamic game in continuous time with nonlinearities. Adopting a dynamic programming approach, a tractable computational formulation of the problem is proposed together with an accompanying algorithm to find numerical solutions of the couple’s effort problem. The computational analysis of the model is used to explore feeling trajectories, effort control paths, happiness, and stabilization mechanisms for different types of successful couples. In particular, the simulation analysis provides insight into the pattern of change of both marital quality and effort making in intact marriages and how they are affected by certain level of heterogamy in the couple.

Kinetics and mechanisms of catalyzed dual-E (antithetic) controllers

Homeostasis plays a central role in our understanding how cells and organisms are able to oppose environmental disturbances and thereby maintain an internal stability. During the last two decades there has been an increased interest in using control engineering methods, especially integral control, in the analysis and design of homeostatic networks. Several reaction kinetic mechanisms have been discovered which lead to integral control. In two of them integral control is achieved, either by the removal of a single control species E by zero-order kinetics ("single-E controllers"), or by the removal of two control species by second-order kinetics ("antithetic or dual-E control"). In this paper we show results when the control species E 1 and E 2 in antithetic control are removed enzymatically by ping-pong or ternary-complex mechanisms. Our findings show that enzyme-catalyzed dual-E controllers can work in two control modes. In one mode, one of the two control species is active, but requires zero-order kinetics in its removal. In the other mode, both controller species are active and both are removed enzymatically. Conditions for the two control modes are put forward and biochemical examples with the structure of enzyme-catalyzed dual-E controllers are discussed.

Preface

The 5th International Conference on Chemical Engineering, Food and Biotechnology (ICCFB2021) Dear Authors, honored Readers, It is with my deep pleasure that I write this Foreword to the Manuscript Collection of the 5th ICCFB - International Conference on Chemical Engineering, Food and Biotechnology held in Ho Chi Minh City, Vietnam, in November 4-5, 2021. Unfortunately, since June 2021, the 4th outbreak of the COVID-19 pandemic has caused social distancing regulations in the whole Vietnam; therefore, the conference committees decided to change the meeting to a virtual format. The 5th ICCFB with the theme “Chemical, Food and Biological Process Development towards Sustainability and Digital Transformation” is expected that the emerging technologies and scientific advancements in all the fields will be disseminated during the Conference. It also intends to create a forum for strengthening partnership between academia and industry towards industrial applications. The papers contributed the most recent scientific knowledge known in the field of Animal and Plant Cell Technology, Protein Engineering, Bioenvironmental Engineering, Bioactive Compounds and Food Biotechnology, Catalyst and Reaction Engineering, Renewable Energy Technology, Environmental and Safety Engineering, Fundamental of Chemical, Engineering and Applied Chemistry, Industrial Chemical Engineering, Material Science and Technology, Process and Control Engineering. All the papers were carefully reviewed with a double-blind review process. In addition to the contributed papers, the keynote speeches were given to make the conference more productive and precious. I believe that this is also the driving force for further research and research in all these areas. We thank all distinguished guests, authors, participants for their contributions to make a successful conference and look forward to the 6th ICCFB in 2023. Dr. Tran Tan Viet Program Chair ICCFB2021 List of Conference Chairs and Editors, Invited Speakers, Technical Committees are available in this pdf.