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This article presents the design of a test device for cryogenic testing of concrete samples. Cryogenic tests consisted of compression and expansion tests of liquid nitrogen on cylindrical concrete specimens and their scope was to determine the linear coefficient of thermal expansion of the concrete material at temperatures from zero to minus 160° C. This article presents a design. Τhe test chamber and the new strategies that were used; along with the corresponding challenges posed by the heating and measurement problems. Affected heat transfer transient and steady state problems, which were realized using digital analysis using commercial FEM software, are presented along with the measurement equipment and methods that were used to match the numerically calculated temperature profiles along with the measured ones. In addition, the sample temperature measurement topology that was chosen for the experiments is compared with conventional ones in their ability to provide information representing the temperature state of the sample. Finally, the raw data from three tests are analyzed and the results are presented in appropriate graphs, taking into account the systematic errors introduced by thermal compression of the metrological equipment used for measuring length. The results are consistent with those available in the concrete literature.

The busbars for the HL-LHC magnets are made of Nb-Ti/Cu conductor, the insulation system, and the auxiliary equipment to align the busbars with respect to the magnet coldmasses. This paper presents design options concerning the integration of the busbars inside the coldmass with a fixed point, and a reinforced insulation system for the flexible busbar part using thin PEEK tubes. Prototype splices for interconnecting Nb3Sn and Nb-Ti Rutherford cables, and round and flat 18 kA Nb-Ti cable have been produced and first test results are presented.

This paper presents an analysis of the contact and bending stresses of certain self-aligning automotive spur gear designs under various degrees of misalignment. The resulting deflection and stress fields are studied under quasi-static conditions and compared for different design variants. The proposed solution not only seems to eliminate the necessity to conduct gear tooth crowning, but also makes practical the increase of gear width and a corresponding reduction of the gear module, potentially further benefitting gear dynamics and efficiency.

High-ratio compound stepped planetary transmissions are typically characterised by poor overall efficiencies, even if the individual mesh efficiencies are high, because of the very high sliding velocities imposed by the kinematics of their topologies. Here, a parametric exploration of the design space is presented for a stepped transmission topology, which is assessed in terms of transmission ratio, efficiency, and power density. It is confirmed that high ratio per (compound) stage is accompanied by low mechanical efficiency and/or large volume for the most part of the parametric design space, as is also anticipated by prior research. At the same time, specific niche regions of particular importance are identified that combine high-ratio, high-efficiency, and good power density.