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To generate enough thrust for a Tunnel Boring Machine (TBM) to excavate a soil and advance, several jacks are typically used to apply force to the last installed ring that acts as a reaction frame. These loads generate bursting stresses that might cause cracks in the longitudinal direction of the segments. Many studies dedicated to evaluating this phenomenon focus mainly on elements with similar height-to-length ratios. To cover the wide variety of dimensions and load application patterns, additional experimental assessments are required. The objectives of the present paper are to extend the study of with different height-to-length ratios subjected to concentrated loads and to validate analytical formulations for the verification of concrete segments in SLS and ULS. To accomplish this, an experimental program was constructed using small-scale specimens with and without fibre reinforcement. The results obtained were used to validate the formulations derived from a struts-and-ties model. Finally, an application of the formulation proposed to the case study of Line 9 in Barcelona is presented. This study represents a contribution towards the development of simplified tools for the design of segmented linings both in the SLS and in the ULS.

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The design of effective supporting matrices to efficiently cycle Si nanoparticles is often difficult to achieve and requires complex preparation strategies. In this work, we present a simple synthesis of low-cost and environmentally benign aAnatase TiO nanoparticles as buffering filler for Si nanoparticles (Si@TiO ). The average anatase TiO crystallite size was approximately 5 nm. A complete structural, morphological, and electrochemical characterization was performed. Electrochemical test results show very good specific capacity values of up to 1000 mAh g and cycling at several specific currents, ranging from 500 to 2000 mA g , demonstrating a very good tolerance to high cycling rates. Postmortem morphological analysis shows very good electrode integrity after 100 cycles at 500 mA g specific current.

Fe3O4 nanoparticles synthesized by a base catalyzed method are tested in an All-Solid-State (ASLB) battery using a sulfide electrolyte. The pristine nanoparticles were morphologically characterized showing an average size of 12 nm. The evaluation of the electrochemical properties shows high specific capacity values of 506 mAhg−1 after 350 cycles at a specific current of 250 mAg−1, with very high stability and coulombic efficiency.

Conversion‐enabled transition metal oxides are mostly characterized by environmental benignity, low cost, and high theoretical capacities, which make them suitable as candidate anode materials for Li‐ion batteries. To ensure high efficiency and stability, the use of novel and tailored morphologies is recommended. Among the other methods, the use of natural extracts as templates is one of the possible strategies to accomplish this task. In this work, Fe2O3 nanoparticles are synthesized by using vanillin as a soft templating agent, and fully characterized on a morphological, structural and electrochemical level. Poly(acrylic acid) binder and ethanol for electrode preparation ensure a fully environmentally benign process from synthesis to electrode testing. The cells deliver capacity values up to 700 mAh g−1 under prolonged galvanostatic cycling at 500 mA g−1, as well as excellent rate capability and high efficiency.

Composite anode material based on Fe3O4 and reduced graphene oxide is prepared by base-catalysed co-precipitation and sonochemical dispersion. Structural and morphological characterizations demonstrate an effective and homogeneous embedding of Fe3O4 nanoparticles in the carbonaceous matrix. Electrochemical characterization highlights specific capacities higher than 1000 mAh g−1 at 1C, while a capacity of 980 mAhg−1 is retained at 4C, with outstanding cycling stability. These results demonstrate a synergistic effect by nanosize morphology of Fe3O4 and inter-particle conductivity of graphene nanosheets, which also contribute to enhancing the mechanical and cycling stability of the electrode. The outstanding capacity delivered at high rates suggests a possible application of the anode material for high-power systems.

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