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The application of carbon fiber reinforced polymers (CFRP) as method of strengthening for concrete structures is replacing the conventional strengthening through the bonding of steel plates. However, since it is a recent technique, several codes from different countries still do not consider this type of strengthening. In this work, seven reinforced concrete beams were tested and analyzed. One was used as a reference beam and six were strengthened through the application of CFRP, with some variations regarding the strengthening, with the aim of verifying the efficiency of each system compared to the reference beam. For the computational analysis, the software ANSYS was used along with the plugin ACP (ANSYS Composite PrepPost), by comparing the results obtained in the simulation of the experimental results. Through the laboratory tests and the finite element simulation, it was concluded that the strengthening was efficient in all situations, but it was less efficient in cases where the strengthening was extended to the regions of simple flexure without proper anchorage. It was also possible to notice that the behavior of the simulated beams properly represented the reality, with the beams behaving comparably to the beams of the experimental test.

The Event Horizon Telescope (EHT) Collaboration recently published the first images of the supermassive black holes in the cores of the Messier 87 and Milky Way galaxies. These observations have provided a new means to study supermassive black holes and probe physical processes occurring in the strong-field regime. We review the prospects of future observations and theoretical studies of supermassive black hole systems. Current ground-based very-long-baseline interferometry (VLBI) arrays like the EHT and proposed future extensions like the next-generation Event Horizon Telescope will greatly enhance the capabilities of black-hole imaging interferometry. These enhancements will open up several previously inaccessible avenues of investigation, thereby providing important new insights into the properties of supermassive black holes and their environments. This review describes the current state of knowledge for five key science cases, summarising the unique challenges and opportunities for fundamental physics investigations that future mm/sub-mm VLBI developments will enable.

Observers in relative motion or at different gravitational potentials measure disparate clock rates. These predictions of relativity have previously been observed with atomic clocks at high velocities and with large changes in elevation. We observed time dilation from relative speeds of less than 10 meters per second by comparing two optical atomic clocks connected by a 75-meter length of optical fiber. We can now also detect time dilation due to a change in height near Earth's surface of less than 1 meter. This technique may be extended to the field of geodesy, with applications in geophysics and hydrology as well as in space-based tests of fundamental physics.

This review is focused on tests of Einstein’s theory of general relativity with gravitational waves that are detectable by ground-based interferometers and pulsar-timing experiments. Einstein’s theory has been greatly constrained in the quasi-linear, quasi-stationary regime, where gravity is weak and velocities are small. Gravitational waves will allow us to probe a complimentary, yet previously unexplored regime: the non-linear and dynamical strong-field regime. Such a regime is, for example, applicable to compact binaries coalescing, where characteristic velocities can reach fifty percent the speed of light and gravitational fields are large and dynamical. This review begins with the theoretical basis and the predicted gravitational-wave observables of modified gravity theories. The review continues with a brief description of the detectors, including both gravitational-wave interferometers and pulsar-timing arrays, leading to a discussion of the data analysis formalism that is applicable for such tests. The review ends with a discussion of gravitational-wave tests for compact binary systems.

This paper presents an analysis and results of experimental tests of full-scale prefabricated balcony sets with dimensions (width × length × height): 2.0 m × 2.78 m × 0.186 m (in a slope to 0.17 m). The sets consist of reinforced concrete slabs (balcony and ceiling) connected with each other with double-type balcony connections. The paper analyses the impact of variable parameters on the load bearing capacity of the elements. Additionally, an overview of current scientific and technical papers in the field of balcony connections is provided.

This paper presents an analysis and results of experimental tests of full-scale prefabricated balcony sets with dimensions (width × length × height): 2.0 m × 2.78 m × 0.186 m (in a slope to 0.17 m). The sets consist of reinforced concrete slabs (balcony and ceiling) connected with each other with double-type balcony connections. The paper analyses the impact of variable parameters on the load bearing capacity of the elements. Additionally, an overview of current scientific and technical papers in the field of balcony connections is provided.

A search for the doubly charmed baryon Ξ c c + is performed through its decay to the Λ c + K − π + final state, using proton-proton collision data collected with the LHCb detector at centre-of-mass energies of 7, 8 and 13 TeV. The data correspond to a total integrated luminosity of 9 fb −1 . No significant signal is observed in the mass range from 3.4 to 3.8 GeV/ c 2 . Upper limits are set at 95% credibility level on the ratio of the Ξ c c + production cross-section times the branching fraction to that of Λ c + and Ξ c c + + baryons. The limits are determined as functions of the Ξ c c + mass for different lifetime hypotheses, in the rapidity range from 2.0 to 4.5 and the transverse momentum range from 4 to 15 GeV/ c .

The problem of the durability of reinforced concrete structures is arisen, dramatically, in the last decades, showing that one of the most dangerous degradation phenomena is connected to the rebars corrosion. When active corrosion grows the oxides occupy a volume of about 2–4 times, with respect to the sound bar, causing a loss of bond, cracking and cover spalling. In this paper the corrosion effects at the steel–concrete interface are analysed. At this aim, pull-out tests are carried out, with different corrosion levels, for the definition of the bond-slip constitutive relationships of the damaged rebars. Furthermore, an analytical model is developed for evaluating the internal pressure due to corrosion products, for concrete specimens without stirrups, in order to provide a procedure for the definition of the maximum bond as a function of the corrosion percentage. Finally the analytical results are validated through a comparison with the experimental outcomes.

The paper concerns the effects of electrodynamic forces that act on the current paths of the industrial low-voltage busbar. This work is composed of experimental and simulation sections. In the experimental section, the short circuit tests were presented, and the occurrence of electrodynamic forces was demonstrated. The formation of electrodynamic forces in the current circuits of electrical energy distribution systems is related to the flow of high currents, mostly short circuit currents. To highlight those phenomena a detailed specification of parameters during tests was displayed. In the simulation section, the physical phenomenon of electrodynamic forces is captured by employing a detailed real-scale model of a commercial busbar. Therefore, the authors proposed the employment of the FEA (finite element analysis) to obtain values of electrodynamic forces acting on the current paths by executing a detailed 3D coupled simulation. The analysis of the results and aftermath effects of their interactions led to interesting conclusions that concerned the operation of such power distribution circuits under short-circuit conditions.

The goal of this paper is to improve the mechanical strength-to-weight ratios of metal cubic lattice structures using unit cells with fillet shapes inspired by triply periodic minimal surfaces (TPMS). The lattice structures here presented were fabricated from AA6082 aluminum alloy using lost-PLA processing. Static and dynamic flat and wedge compression tests were conducted on samples with varying fillet shapes and fill factors. Finite element method simulations followed the static tests to compare numerical predictions with experimental outcomes, revealing a good agreement. The TPSM-type fillet shape induces a triaxial stress state that significantly improves the mechanical strength-to-weight ratio compared to fillet radius-free lattices, which was also confirmed by analytical considerations. Dynamic tests exhibited high resistance to flat impacts, while wedge impacts, involving a high concentrated-load, brought out an increased sensitivity to strain rates with a short plastic deformation followed by abrupt fragmentation, indicating a shift towards brittle behavior.