Resistive Plate Chambers detectors are extensively used in several domains of Physics. In High Energy Physics, they are typically operated in avalanche mode with a high-performance gas mixture based on Tetrafluoroethane (C2H2F4), a fluorinated high Global Warming Potential greenhouse gas. The RPC EcoGas@GIF++ Collaboration has pursued an intensive R&D activity to search for new gas mixtures with low environmental impact, fulfilling the performance expected for the LHC operations as well as for future and different applications. Here, results obtained with new eco-friendly gas mixtures based on Tetrafluoropropene and carbon dioxide, even under high-irradiation conditions, will be presented. Long-term aging tests carried out at the CERN Gamma Irradiation Facility will be discussed along with their possible limits and future perspectives.
New 1,4-disubstituted pyrazoles featuring benzodioxane as the basic skeleton have been synthesized successfully through a copper-catalyzed cycloaddition reaction of alkynes with 3-arylsydnones, a process that is typically challenging using conventional methods. These newly synthesized compounds have been identified through comprehensive analysis of NMR (1H and 13C). Furthermore, the structures of 5d and 5f were resolved by single crystal X-ray diffraction (SCXRD) analysis. Both compounds crystallize in the monoclinic system in the space group C2/c. The structures were stabilized by C-H & sdot;& sdot;& sdot;O and C-H & sdot;& sdot;& sdot;N hydrogen bonds with C-H & sdot;& sdot;& sdot;pi and pi & sdot;& sdot;& sdot;pi interactions. Hirshfeld surface analysis for crystal packing indicates that the most important contributions are H & ctdot;H (40.3% 5d, 37.8% 5f), O & ctdot;H/H & ctdot;O (18.8% 5d, 21.7% 5f), and C...H/H...C (22.8% 5d, 21.8% 5f) interactions. DFT calculations were carried out for 4a-c and 5a-f using B3LYP/6-31G(d, p) methodology to predict their preferred interaction sites. Natural bond orbital (NBO) analysis was carried out to investigate the intramolecular interactions of all molecules. Through molecular docking studies, strong interactions between 1,4-disubstituted pyrazole featuring benzodioxane and the active sites of both acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) were observed. They were particularly notable for their affinity with key amino acid residues within the active sites. Such revelations illuminate a promising path forward, suggesting that the 1,4-disubstituted pyrazole featuring benziodioxane holds significant potential for Alzheimer's therapy.
The greatest challenge in strengthening deep reinforced concrete beams is overcoming brittle shear failure. Premature shear failure limits reliable flexural strengthening by preventing the full structural capacity of FRP reinforcement from being mobilized. To address this limitation, 36 RC T-beams with low shear span-to-depth ratios (a/d < 2.5), including under- and over-reinforced sections, were experimentally investigated. The beams were strengthened using externally bonded CFRP and bidirectional E-glass woven roving GFRP composites, the latter systematically evaluated as an economical strengthening alternative. An innovative NSM technique employing epoxy-impregnated rolled FRP sheets inserted into pre-cut grooves, acting similarly to conventional NSM FRP bars, was also developed. The experimental results showed that the effectiveness of FRP strengthening depended strongly on the reinforcement configuration and the governing failure mechanism. While selected configurations produced significant improvements in load-carrying capacity, ductility, and energy absorption, the tested beams predominantly exhibited diagonal cracking and brittle shear-dominated failure, which limited the full utilization of the FRP reinforcement. Across the four experimental series, the investigated FRP configurations produced a maximum 49.01% increase in load-carrying capacity, achieved with the U ±45° configuration, demonstrating the effectiveness of inclined FRP reinforcement in intercepting shear cracks and improving stress transfer. In terms of ductility, the configuration combining longitudinal reinforcement for the opening with 45° cross reinforcement exhibited the most pronounced improvement, with a 220.7% increase in energy-based ductility relative to the control beam. These findings demonstrate that, although FRP strengthening can substantially enhance the structural response of deep RC T-beams, shear remains a critical limiting mechanism. Integrated flexural shear strengthening is therefore essential to fully exploit the capacity of FRP systems in shear-dominated deep RC T-beams.
Logicism is the thesis that mathematics can be derived from logic. In both The Principles of Mathematics and Principia Mathematica, Russell sets out to demonstrate that mathematics can be deduced from a small number of “indefinable” concepts and “primitive propositions.” But until now, little attention has been paid to the conception of mathematics induced by this logicist approach: What mathematics were the logicians seeking to reduce? How did they treat the differences between mathematical disciplines (as, for example, the differences between arithmetic, algebra, geometry, etc.)? Did they consider that the demarcations between fields within mathematics had to be derived logically, or did they consider, on the contrary, that this was unnecessary? This chapter addresses this question and shows, by examining the organization of both The Principles and Principia Mathematica, that the ambition of Russellian logicism was not only to deduce the content of mathematics but also to account for its architecture.
