Categorical Dimensions of Human Odor Descriptor Space Revealed by Non-Negative Matrix Factorization

In contrast to most other sensory modalities, the basic perceptual dimensions of olfaction remain unclear. Here, we use non-negative matrix factorization (NMF) – a dimensionality reduction technique – to uncover structure in a panel of odor profiles, with each odor defined as a point in multi-dimensional descriptor space. The properties of NMF are favorable for the analysis of such lexical and perceptual data, and lead to a high-dimensional account of odor space. We further provide evidence that odor dimensions apply categorically. That is, odor space is not occupied homogenously, but rather in a discrete and intrinsically clustered manner. We discuss the potential implications of these results for the neural coding of odors, as well as for developing classifiers on larger datasets that may be useful for predicting perceptual qualities from chemical structures

Review of next generation hydrogen production from offshore wind using water electrolysis

\ua9 2023 The Author(s)Hydrogen produced using renewable energy from offshore wind provides a versatile method of energy storage and power-to-gas concepts. However, few dedicated floating offshore electrolyser facilities currently exist and therefore conditions of the offshore environment on hydrogen production cost and efficiency remain uncertain. Therefore, this review focuses on the conversion of electrical energy to hydrogen, using water electrolysis located in offshore areas. The challenges associated with the remote locations, fluctuating power and harsh conditions are highlighted and recommendations for future electrolysis system designs are suggested. The latest research in polymer electrolyte membrane, alkaline and membraneless electrolysis are evaluated in order to understand their capital costs, efficiency and current research status for achieving scaled manufacturing to the GW scale required in the next three decades. Operating fundamentals that govern the performance of each device are investigated and future recommendations of research specifically for the integration of water electrolysers with offshore wind turbines is presented

A Simple and Efficient Non-Noble Cathode Catalyst Based on Carbon Hollow Nanocapsules Containing Cobalt-Based Materials for Anion Exchange Membrane Water Electrolyzer

\ua9 2025 Wiley-VCH GmbH.An efficient approach for fabrication of non-noble metal-based electrocatalyst is desirable for designing the energy storage and conversion devices in real-world usages due to low cost and excellent catalytic properties. The preparation of hollow carbon capsules (HCC) containing cobalt (Co)-based electrocatalyst is reported by a simple synthesis process without using templates for the first time. Initially, cobalt phenylphosphonate (Co-MOF) nanorods are fabricated through a simple hydrothermal approach. The as-formed Co-MOF is covered with a thin coating of polydopamine (DP-Co-MOF) through chemical polymerization of dopamine in Tris-HCl (pH 8.5). The DP-Co-MOF is used as self-degraded template for the formation of HCC under pyrolysis. The formation mechanism and hydrogen evolution reaction (HER) activity of HCC are investigated. The hollow structure derived under N2 exhibits a low overpotential (295 mV at 100 mA cm−2) with excellent stability (90.98%) for 150 h, which is further verified by density functional theory (DFT) calculations. Finally, the designed anion exchange membrane (AEM) water electrolyzer based on C─Co─N as cathode delivers a current density of 500 mA cm−2 (at 2.19 V) and 1000 mAcm−2 (at 2.33 V) in 1.0 m KOH at 60 \ub0C. The fabricated new Co-based electrocatalyst is highly beneficial for the fabrication of cost-effective and high-performance AEMWEs

Boosting the oxygen evolution activity in non-stoichiometric praseodymium ferrite-based perovskites by A site substitution for alkaline electrolyser anodes

Sustainable fossil fuel free systems are crucial for tackling climate change in the global energy market, and the identification and understanding of catalysts needed to build these systems plays a vital role in their development. ABO3−δ perovskite oxides have been observed to be potential replacement materials for the high-performing, but low ionic conducting and economically unfavourable Pt and IrO2 water splitting catalysts. In this work increased addition of Sr2+ aliovalent dopant ions into the crystal lattice of Pr1−xSrxFeO3−δ perovskites via A site substitution was seen to drastically improve the electrocatalytic activity of the oxygen evolution reaction (OER) in alkaline environments. The undoped PrFeO3−δ catalyst was not catalytically active up to 1.70 V against the reversible hydrogen electrode (RHE), whilst an onset potential of 1.62 V was observed for x = 0.5. Increased strontium content in Pr1−xSrxFeO3−δ was found to cause a reduction in the lattice parameters and crystal volume whilst retaining the orthorhombic Pbnm space group throughout all dopant levels, analysed using the Rietveld method. However, it was noted that the orthorhombic distortion was reduced as more Sr2+ replaced Pr3+. The mechanism for the increased electrocatalytic activity with increased strontium is due to the increasing concentration of oxygen vacancy (δ), leading to increased catalyst site availability, and the increased average oxidation state of Fe cations, consistent with the iodometric titration results. This results in shifting the average d shell eg electron filling further towards unity. X-ray photoelectron spectrum of the O 1s core level also shows the presence of lattice oxide and surface hydroxide/carbonate. This work shows promise in that using the more abundant and more economically friendly material of strontium allows for improved OER catalytic activity in otherwise inactive perovskite catalyst oxides

Efficient ethane production via SnCl4 Lewis acid-enhanced CO2 electroreduction in a flow cell electrolyser

\ua9 2025 The Royal Society of Chemistry. The development of efficient and selective catalysts for electrochemical CO2 reduction (ECR) is critical for advancing sustainable energy solutions. Here, we report a unique catalyst system based on SnCl4 Lewis acid-modified Cu2O, demonstrating enhanced performance in CO2 electroreduction to ethane. The SnCl4 modification introduces chloride ions directly onto the Cu2O surface, creating a synergistic interaction between Sn, Cl, and Cu active sites that optimizes the electronic environment for ECR. The SnCl4 catalyst was deposited on Cu2O coated gas diffusion electrode (GDE) and tested in a flow cell electrolyser, integrating a Fumasep bipolar membrane and platinum (Pt) foil anode. This system achieved a peak faradaic efficiency of 34.8% for ethane production at −1.0 V vs. RHE, along with 11.3% efficiency for ethylene. Electrochemical studies revealed that the SnCl4-modified Cu2O exhibits low charge transfer resistance and high stability during prolonged electrolysis, achieving a total current density of 74.8 mA cm−2 with a Tafel slope of 92.3 mV dec−1 at 0.4 V overpotential. Mechanistic investigations, supported by density functional theory, Raman, XRD, and electrochemical impedance spectroscopy analyses, highlight the critical role of chloride ions in stabilizing CO intermediates and facilitating C-C bond formation, essential for C2 product generation. Operating in a flow cell configuration, the system demonstrated high energy efficiency and selectivity, establishing the SnCl4-modified Cu2O (CTC) as a promising catalyst for ECR. These findings offer a scalable and economically viable pathway for renewable hydrocarbon production, paving the way for practical applications in carbon-neutral energy cycles

Innovative Tin and hard carbon architecture for enhanced stability in lithium-ion battery anodes

\ua9 2024Tin (Sn), with a theoretical capacity of 994 mAh g-1, is a promising anode material for lithium-ion batteries (LIBs). However, fundamental limitations like large volume expansion during charge-discharge cycle and confined electronic conductivity limit its practical utility. Here, we report a new material design and manufacturing method of LIB anodes using Sn and Hard Carbon (HC) architecture, which is produced by Physical Vapor Deposition (PVD). A bilayer HC/Sn anode structure is deposited on a carbon/copper sheet as a function of deposition time, temperature, and substrate heat treatment. The developed anodes are used to make cells with a lithium-ion electrolyte using a specific fabrication process. The morphology, atomic structure, conductivity, and electrochemical performance of the developed HC/Sn anodes are studied with SEM, TEM, XPS, and electrochemical techniques. At a discharge rate of 0.1C, the Snheated + HC anode performs exceptionally well, offering a capacity of 763 mAh g-1. It is noteworthy that it achieves a capacity of 342 mAh g-1 when fast charging at 5C, demonstrating exceptional rate capability. The Snheated + HC anode maintains >97 % Coulombic efficiency of its capacity after 3000 cycles at a rate of 0.1C after 3000 cycles 730.5 mAh g-1 recorded, demonstrating an impressive cycle life. The novel material design approach of the Snheated + HC anode, which has a multi-layered structure and HC acting as a barrier against volumetric expansion and improving electronic conductivity during battery cycling, is perceived as influential in uplifting anode\u27s performance

Acetic Acid Bacteria: Physiology and Carbon Sources Oxidation

Acetic acid bacteria (AAB) are obligately aerobic bacteria within the family Acetobacteraceae, widespread in sugary, acidic and alcoholic niches. They are known for their ability to partially oxidise a variety of carbohydrates and to release the corresponding metabolites (aldehydes, ketones and organic acids) into the media. Since a long time they are used to perform specific oxidation reactions through processes called “oxidative fermentations”, especially in vinegar production. In the last decades physiology of AAB have been widely studied because of their role in food production, where they act as beneficial or spoiling organisms, and in biotechnological industry, where their oxidation machinery is exploited to produce a number of compounds such as l-ascorbic acid, dihydroxyacetone, gluconic acid and cellulose. The present review aims to provide an overview of AAB physiology focusing carbon sources oxidation and main products of their metabolism