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Metal hydrides are known for their outstanding performance as materials for hydrogen storage and processing. These materials find applications for short- and long-term energy storage, compression and supply of hydrogen gas, thermal energy storage, as electrodes and electrolytes in rechargeable batteries, for the microstructural optimisation of functional materials, in thin film technologies, as catalysts, getters and in many other uses. After the discovery of the first binary metal hydrides back in the 19th century, their studies covered all possible binary M-H systems and expanded rapidly into the field of ternary hydrides following the recognition of the excellent hydrogen storage performance of LaNi5- and TiFe-based materials, which operate efficiently at room temperature and at near-ambient H2 pressures. This review aims to provide an overview of the early works, as well as selected recent results on various classes of metal hydrides. It also covers the recent activities from the major contributing countries and continents, including USA, Europe, Japan, China and Australia. These studies relate to achieving the hydrogen storage systems goals set by the Department of Energy in the United States which inspired the research activities at the national and international level, through execution of the tasks on hydrogen-based energy storage managed by the International Energy Agency. The review is prepared by international experts in the field and covers the most important past developments and also presents the recent achievements in the field.
Permanent storage of gigatons of carbon in basalt requires thick, uncompartmentalized sequences that allow lateral dissipation of CO2 away from injection sites. Here we assess the presence of flow barriers by evaluating the variations in 87Sr/86Sr patterns in pore water, a method used extensively in sedimentary successions. Present-day pore water 87Sr/86Sr was measured from residual salts in core samples, while past water compositions were reconstructed from carbonate cements of different ages. We reveal smooth and uninterrupted trends in strontium isotopes through a 100 m thick basalt section indicating a common fluid reservoir unaffected by low-permeability massive lava flow interiors. The data further indicate that unconsolidated overburden sediments act as a good seal preventing seawater to mix with in situ pore water, and buoyant supercritical CO2 to leak. Finally, basaltic sequences form viable targets for CO2 storage and suggests that fractures may bypass low-permeability units to create a well-connected reservoir system. 87Sr/86Sr pattern of residual salts from a 100 m basalt section reveal a vertically connected pore water system unaffected by massive lava flow interiors, supporting continental margin basalt sequences as viable reservoirs for permanent CO2 storage.
Conventional wastewater treatment technologies are often ineffective in eliminating persistent micropollutants, such as neonicotinoid pesticides, which pose significant risks to ecosystems and human health. To address this challenge, silicon-modified black titanium dioxide (Si-b-TiO2) photocatalysts were synthesised via a sol-gel route followed by chemical reduction, targeting sustainable environmental remediation under full-spectrum solar irradiation. Controlled Si incorporation (1-15 wt%) tuned the structural, optical, and electronic properties of black TiO2, as confirmed by XRD, TEM, and XPS and FT-IR analyses. Silicon modification suppressed electron-hole recombination and enhanced visible-light absorption, accompanied by increased generation of reactive oxygen species, as evidenced by hydroxyl radical (HO center dot) probing using terephthalic acid fluorescence. The optimised Si1-b-TiO2 photocatalyst achieved an imidacloprid degradation efficiency of approximately 70% within 180 min under full-spectrum irradiation, compared to similar to 34% for pristine black TiO2, corresponding to an apparent rate constant of k = 6.84 & sdot; 10(-3) min(-1). In addition, the catalyst retained more than 90% of its initial activity after five consecutive degradation cycles, demonstrating good operational stability. At higher Si loadings (>= 5 wt%), performance decreased due to pore blockage and recombination, underlining the importance of controlled doping. This work demonstrates that Si-modified black TiO2 provides a cost-effective and scalable material platform for solar-driven water purification, contributing to the development of sustainable technologies for mitigating micropollutants.
The prevalence of social robots is increasing, with examples such as customer service robots in malls and airports. This trend highlights the importance of transparency, particularly in data-sharing interactions with social robots operating in public spaces, where users may be asked to provide personal information to receive personalized experiences. This article investigates how design transparency influences user trust and data-sharing behavior in human-robot interactions. We conducted an experiment with 143 participants who interacted with the social robot ARI under two transparency conditions: low and high transparency. In the low-transparency condition, participants were informed about the data being collected and could choose to save or delete it. In the high-transparency condition, the robot additionally indicated the sensitivity level of each data item: low (e.g., scenario preference), medium (e.g., name and e-mail), and high (e.g., religious beliefs), allowing participants to make more informed decisions. Participants were presented with two scenarios: exploring city events and discovering local attractions. They received personalized recommendations based on their preferences, with the option to provide personal data (name, phone number, e-mail) for possible future communication. After the interaction, participants decided whether to save or delete the data they had shared. The results indicated that while transparency did not significantly affect trust in the robot, it influenced data-sharing behavior. In particular, participants in the high-transparency condition demonstrated more cautious behavior, opting to save less data and delete more. Furthermore, the results showed that both sensitivity levels and transparency influenced the participants’ data-sharing choices. Low-level sensitivity data led to the highest rates of saving and the lowest rates of deleting, while medium-level sensitivity data showed the opposite pattern. These findings highlight the need to align data categorization with user perceptions to address data sharing concerns more effectively.
Rare earth elements (REEs) flotation from carbonatitic ores remains challenging due to the complex association between REE-bearing minerals and carbonate-rich gangue phases. Although previous studies have reported REE beneficiation from the Fen Deposit, the influence of depressant type, sodium silicate dosage, EDTA addition, and collector selection on flotation selectivity remains poorly understood. Therefore, this study presents a preliminary assessment of different reagent schemes for the flotation of REE-bearing minerals from the Fen Deposit. Chemical and mineralogical characterization confirmed the predominance of light REEs, mainly Ce and La, associated with monazite and fluorocarbonate minerals of the bastn & auml;site-parisite-synchysite group. Flotation screening tests revealed limited gangue rejection, particularly for Ca- and Ba-bearing minerals, indicating that mineralogical complexity strongly influences flotation selectivity. Among the depressants evaluated, sodium silicate and citric acid exhibited the most promising performance, while EDTA enhanced the total rare earth oxides (TREO) grade at higher sodium silicate dosages. Collector tests resulted in moderate REE enrichment in the overflow products, with NaOL yielding the highest recovery (similar to 62%). However, TREO grades remained relatively low (similar to 2.3-2.7%), suggesting that reagent selection alone is insufficient to overcome the flotation limitations imposed by the ore from the Fen Deposit. The results provide an exploratory evaluation of reagent schemes for Fen carbonatite ore and identify key challenges and opportunities for future process optimization.
