The 1 to 100 nm nanoscale is a scale at which chemical reactions and biomolecular interactions can occur; the human skin is no exception. Regarding dermal exposure, engineered nanoparticles are used in numerous cosmetic formulations such as sunscreen, cleansers, creams, lotions, and makeup products. Their ability to improve ultraviolet protection, pigmentation, moisturization, and promote skin repair, and skin retention is appreciated. On the skin, nanomaterials first encounter resident bacteria and small molecules, i.e., the microbiome, and later interact with the superficial skin cells. The interaction of nanomaterials with the skin is complex because of their different compositions, reactivity, and scale. Physical and chemical features, composition, persistence in the environment, and transport across media are all factors that will affect nanomaterials' potential toxicity on humans and the environment. This review article focuses on current cosmetic ingredients claiming a nano nature, the unique characteristics of nanomaterials and their behaviour on the skin, how they can be suitable for natural cosmetics and how they behave in the environment.

Carbon nanotubes (CNTs) have remarkable mechanical, electrical, and thermal properties, making them highly attractive as foundational elements for advanced materials. However, translating their nanoscale potential into macroscale reliability and longevity requires a holistic design approach that integrates precise architectural control with robust damage mitigation strategies. This review presents a synergistic perspective on enhancing the durability of CNT-based systems by critically examining the interplay between molecular assembly, self-repair mechanisms, and the advanced characterization techniques required for their validation. We first establish how foundational architectural control—achieved through strategies like chemical functionalization, field-directed alignment, and dispersion—governs the ultimate performance of CNT materials. A significant focus is placed on advanced functionalization, such as fluorination, and its verification using high-powered spectroscopic tools, including X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. Subsequently, this manuscript delves into the mechanisms of self-repair, systematically analyzing both the intrinsic capacity of the carbon lattice to heal atomic-level defects and the extrinsic strategies that incorporate engineered healing agents into composites. This discussion is uniquely supplemented by an exploration of the experimental techniques, such as electron energy loss spectroscopy (EELS) and Auger electron spectroscopy (AES), that provide crucial evidence for irradiation-induced healing dynamics. Finally, we argue that a “characterization gap” has limited the field’s progress and highlight the critical role of techniques like in situ Raman spectroscopy for quantitatively monitoring healing efficiency at the molecular level. By identifying current challenges and future research frontiers, this review underscores that the creation of truly durable materials depends on an integrated understanding of how to build, repair, and precisely measure CNT-based systems.

Escalators have been recommended instead of elevators during the COVID-19 pandemic since it allows transportation for a large number of people without being enclosed in a small indoor space. Escalators have a tremendous capacity to move large numbers of people and are commonly used in various public facilities such as shopping centers, supermarkets, airports, and subways. This current study focused on investigating the transmission of cough droplets from an infected source person traveling on an Upward Moving Escalator (UME) using the ANSYS FLUENT. The Eulerian-Lagrangian method combined with two-way coupling was used to numerically obtain the aerosol transport, spatial distribution, and deposition information in the UME. The effect of UME operational speed and Relative Humidity (RH) was also investigated through multiphase flow. Finally, multi-objective optimization was performed using a Genetic Algorithm (GA). The investigation revealed that the hand railings were one of the most susceptible contaminated surfaces to the expelled respiratory droplets. The cough droplets expelled from the mouth entered the recirculation zones via the upper portion of the shoulder and wake zone behind the torso. The droplets contaminated the lower portion of the human body at lower operational speed if another passenger stood two steps behind the infected person. Higher operational speeds and lower RH demonstrated higher penetration lengths. The optimization indicated higher operational speed and lower RH to maintain lower concentration with higher penetration length.

We investigated the effectiveness of TiO₂ cenospheres in reducing the concentrations of three common harmful compounds, ammonium, nitrate, and nitrite, in fish aquariums. These cenospheres can contribute to more sustainable and eco-friendly aquarium filtration systems while also improving the health of fish. We designed a 30-day experiment with three treatment groups based on the filter type: (1) a control group with a conventional aquarium filter, (2) a group with a TiO₂ cenosphere filter, and (3) a group with a dark TiO₂ cenosphere filter. The water quality was the same baseline in all groups, and each tank was monitored daily for changes in temperature, pH, ammonia, nitrate, and nitrite concentrations. We found that the TiO₂ cenosphere filter was effective in reducing the concentrations of all three pollutants. By the end of the experimental period, the average concentration of nitrite in the control group was 10.7 µM, while the average concentration in the TiO₂ cenosphere filter group dropped 55% to 4.7 µM from the baseline. The average concentration of nitrate was reduced by 17% and ammonia by 28% in the cenosphere-treated group. Hence, the cenospheres were effective in reducing the concentrations of all three pollutants, with the greatest reduction seen for nitrite. These findings support further investigation for incorporating TiO₂ cenospheres into aquarium filtration to help reduce the environmental burden of the aquarium industry.