Experimental methods in chemical engineering: Data processing and data usage in decision-making

Industrial facilities collect large volumes of data, store them according to prescribed protocols, and then interpret them for process decision-making. Several sources and types of error contaminate these data for various reasons, but especially because they come from unreliable or unpredictable instruments. Data (or signal) processing corrects measurement errors to improve fidelity. Here, we highlight decision-making applications and signal processing methods. To fully appreciate the state-of-the-art, we interviewed plant data experts and software developers in the pulp and paper industry to examine how they apply signal processing methods in the context of decision-making, including the value of process data, how these data are used, and the major barriers that prevent plants from using data. Process experts clean data thoroughly with basic approaches compared to the advanced techniques available in the recent literature. The interviews demonstrate that decisions in industry are primarily based on steady-state process operating data. Challenges and barriers that prevent the use of process data to their full potential relate to resource limitations (people, time, and money), an entrenched culture, and access to recent technology. In practice, experts consider, implicitly or explicitly, data that represent the process operating under steady-state conditions. A plant model that represents steady-state operations is easier to interpret, is presented in a form that is usable by plant operators, and in this way, better enables decision-making.     

Single-Atom Catalysts with Ultrahigh Catalase-Like Activity Through Electron Filling and Orbital Energy Regulation

Developing nanomaterials with high H₂O₂-decomposition capacity to replace traditional biological enzymes is of great importance in environmental, semiconductor, and medical fields. However, a lack of understanding of the reaction mechanism leads to aimless catalyst design and limits further improvement of catalytic activity. Here, the regulatory mechanism based on the electron filling and orbital energies of the metal active centers is demonstrated and a rational catalyst design strategy is provided to achieve ultrahigh H₂O₂-decomposition activity. Among the five platinum-group-metal active centers investigated in this study, the Ir–N₄ with partially occupied d_x2−y2 and d_xz orbitals and the highest d-band center most strongly interacts with H₂O₂, and show the lowest energy barrier for H₂O₂ decomposition. As expected, the single-atom Ir catalyst (Ir-NC) shows an ultrahigh H₂O₂-decomposition capacity, which is 1614-times higher than that of natural catalase. Surface-adsorbed atomic oxygen is observed and verified to be the key intermediate for O₂ generation. Biocompatible Ir-NC is effective in scavenging intracellular reactive oxygen species and holds great potential for clinical therapeutics associated with oxidative stress. This study advances the mechanistic understanding of H₂O₂ decomposition and provides useful guidance for rational design of high-performance artificial nanozymes.     

Reconstruction of Low Dimensional Electronic States by Altering the Chemical Arrangement at the SrTiO3 Surface

Developing reliable methods for modulating the electronic structure of the 2D electron gas (2DEG) in SrTiO₃ is crucial for utilizing its full potential and inducing novel properties. Herein, it is shown that relatively simple surface preparation reconstructs the 2DEG at the SrTiO₃ (STO) surface, leading to a Lifshitz-like transition. Combining experimental methods, such as angle-resolved photoemission spectroscopy (ARPES) and X-ray photoemission spectroscopy with ab initio calculations, that the modulation of the surface band structures can be effectively achieved via transforming the chemical composition at the atomic scale is found. In addition, ARPES experiments demonstrate that vacuum ultraviolet light can be efficiently employed to alter the band renormalization of the 2DEG system and control the electron-phonon interaction . This study provides a robust and straightforward route to stabilize and tune the low-dimensional electronic structure via the chemical degeneracy of the STO surface.     

The architecture of the (post) studio: Jackson Pollock’s barn and Andy Warhol’s Silver Factory

This article will discuss a false dichotomy between two models, the modern art studio and the post-studio, which oppose the private and the public, the individual and the collective, hiding and the revealing. We will begin by analysing Daniel Buren’s position in his canonical text “Fonction de l’Atelier” and his practice, where the artist defines the foundations of post-studio work. As the text also describes a New York studio type that must be left behind, we will analyse Jackson Pollock’s and Andy Warhol’s workspaces through drawing reconstructions to demonstrate that these meet the defining characteristics of both models. It will be shown that the artists have used design strategies to retain certain aspects of studio culture while exploring others of the post-studio. This turning point reveals that the current belief about the obsolescence of the studio in a global era defined by communication, networking and mobility ignores its emerging post-studio qualities. This work aims to acknowledge this shift, obtaining a critical vision that will allow us to design contemporary workspaces avoiding stereotypical and reductionist approaches.     

Succinate-based plasticizers: Effect of plasticizer structure on the mechanical and thermal performance of poly(vinyl chloride) plastic formulations

A new family of succinate-based plasticizers, consisting of molecules with a linear alkyl chain capped with n-alkyl succinates on both ends, was evaluated as potential bio-based plasticizers for stiff polymers. The influence of the central and side alkyl chain lengths on the mechanical and thermal properties as well as the migration behavior of poly(vinyl chloride) (PVC)/plasticizer blends was evaluated. The central chain length had the greatest influence on plasticizer performance, with shorter chains leading to blends with higher stress at break and surface hardness, whereas long chains produced softer blends. An optimum chain central length of five carbon atoms was observed, with longer chains leading to reduced compatibility and exudation of the plasticizer at higher plasticizer concentrations. The entire family of plasticizers performed comparably or better than the commercial plasticizer di(2-ethylhexyl) phthalate (DEHP) when incorporated into the blend at concentrations of 20–60 parts per hundred resin (phr). Overall, the succinate-based plasticizers/PVC blends all exhibited equal or improved tensile properties (by up to 77%), surface hardness (reduced by up to 43%), glass transition temperature (reduced by up to 11°C), and migration into organic media (reduced by up to 38%) when compared with blends with DEHP at 40 phr.     

Touchable Electrochemical Hydrogel Sensor for Detection of Reactive Oxygen Species-induced Cellular Senescence in Articular Chondrocytes

In this study, a reactive oxygen species (ROS)-responsive hydrogel sensor (PD/MnO₂ hydrogel) is developed that can efficiently detect senescent cells. Using immature murine articular chondrocytes with serial passages, the sensor can identify small interfering RNA (siRNA) knockdown of peroxisome proliferator-activated receptor-alpha (PPARα) based on the concentration of ROS in cells, simultaneously maintaining its balance via scavenging activity to prevent cartilage degradation in osteoarthritis (OA). The hydrogel sensor exhibits a change in electronic properties, with a distinct resistance from 201.9 kΩ for P0 to 362.9 kΩ for P3, and fluorescence off/on performance with an increase in passaging time. In vitro investigation using PPARα-specific siRNA reveals a correlation between pressure sensitivity and senescent activity, wherein an elevation in observed signal occurred (41.5%). In vivo analysis reveals significant decrease in degradation of the cartilage of both young, 3 months old aged, 18 months old, and PPARα^−/− mice compared to PPARα^+/+ mice based on safranin O stains. The expression level of interleukin-1β is reduced in the cartilage of aged PPARα^−/− mice after implantation with hydrogel, indicating the potential of PD/MnO₂ hydrogel as a therapeutic modality against OA.