A new approach and code for spinning black holes in modified gravity

We discuss and implement a spectral method approach to computing stationary and axisymmetric black hole solutions and their properties in modified theories of gravity. The resulting code is written in the Julia language and is transparent and easily adapted to new settings. We test the code on both general relativity and on Einstein-Scalar-Gauss-Bonnet gravity. It is accurate and fast, converging on a spinning solution in these theories with tiny errors ($\sim \mathcal{O}\left(10^{-13}\right)$ in most cases) in a matter of seconds.Comment: 40 pages, 14 figures. GitHub repository: https://github.com/pgsfernandes/SpinningBlackHoles.jl ; v2: added references, accepted for publication in Classical and Quantum Gravit

RECONSTRUCTION ERROR OF CALIBRATION VOLUME’S COORDINATES FOR 3D SWIMMING KINEMATICS

The aim of this study was to investigate the accuracy and reliability of above and underwater 3D reconstruction of a calibration volume used for swimming analysis. The calibration volume (3x2x3m3) was positioned half above and half below the water surface. Recordings with four underwater and two above water synchronised cameras were done and DLT algorithm used to estimate marker locations. Reconstruction accuracy was determined by the RMS error of 12 validation points and reliability by the standard deviation of all digitisations of the same marker. Comparison among different number of control points showed the set of 24 points to be the most accurate for both environments. Although, the RMS values above water were lower than the RMS values presented underwater. The calibration volume was found to have high accuracy and reliability

Surgical Treatment of Intravenous Leiomyomatosis: The Role of the IVC Filter

IntroductionIntravenous leiomyomatosis is a rare, life-threatening intravenous tumor associated with uterine leiomyomata.ReportThis report describes the case of a 45-year-old woman with a history of weakness and exertional dyspnea, and an extensive intracaval mass extending to the right side of the heart. The tumor was successfully removed in a two-stage surgical procedure with an inferior vena cava (IVC) filter deployed before the second stage. An extensive DVT was observed postoperatively.DiscussionSurgical removal is the only effective treatment for intravenous leiomyomatosis, and the rate of recurrence remains unclear. An IVC filter should be placed routinely to prevent postoperative or late (in case of recurrence) pulmonary embolism

MUSCULAR FATIGUE DURING 200 M FRONT CRAWL

The purpose of this study was to evaluate muscle fatigue in upper and lower limbs as well as trunk muscles during a 200 m all-out front crawl effort. Surface electromyogram was collected from the flexor carpi radialis, biceps brachii, triceps brachii, pectoralis major, trapezius pars superior, rectus femoris, biceps femoris and tibialis anterior of 13 international level male swimmers. Velocity, stroke frequency and stroke length were calculated based on 3D video analysis. Spectral Indices of Muscle Fatigue (IMF) were calculated for each stroke of the each 25 m lap. During the 200 m, the rate of IMF changed against the first lap and increased gradually across successive laps, reflecting the evolvement of muscle fatigue for all studied muscles

Quantification of upper limb kinetic asymmetries in front crawl swimming

This study aimed at quantifying upper limb kinetic asymmetries in maximal front crawl swimming and to examine if these asymmetries would affect the contribution of force exertion to swimming performance. Eighteen high level male swimmers with unilateral breathing patterns and sprint or middle distance specialists, volunteered as participants. A load-cell was used to quantify the forces exerted in water by completing a 30s maximal front crawl tethered swimming test and a maximal 50 m free swimming was considered as a performance criterion. Individual force-time curves were obtained to calculate the mean and maximum forces per cycle, for each upper limb. Following, symmetry index was estimated and breathing laterality identified by questionnaire. Lastly, the pattern of asymmetries along the test was estimated for each upper limb using linear regression of peak forces per cycle. Asymmetrical force exertion was observed in the majority of the swimmers (66.7%), with a total correspondence of breathing laterality opposite to the side of the force asymmetry. Forces exerted by the dominant upper limb presented a higher decrease than from the non-dominant. Very strong associations were found between exerted forces and swimming performance, when controlling the isolated effect of symmetry index. Results point that force asymmetries occur in the majority of the swimmers, and that these asymmetries are most evident in the first cycles of a maximum bout. Symmetry index stood up as an influencing factor on the contribution of tethered forces over swimming performance. Thus, to some extent, a certain degree of asymmetry is not critical for short swimming performance.UBI/FCSH/Santander/2010info:eu-repo/semantics/publishedVersio

Verification and validation of openInjMoldSim, an open-source solver to model the filling stage of thermoplastic injection molding

In the present study, the simulation of the three-dimensional (3D) non-isothermal, non-Newtonian fluid flow of polymer melts is investigated. In particular, the filling stage of thermoplastic injection molding is numerically studied with a solver implemented in the open-source computational library O p e n F O A M ® . The numerical method is based on a compressible two-phase flow model, developed following a cell-centered unstructured finite volume discretization scheme, combined with a volume-of-fluid (VOF) technique for the interface capturing. Additionally, the Cross-WLF (Williams–Landel–Ferry) model is used to characterize the rheological behavior of the polymer melts, and the modified Tait equation is used as the equation of state. To verify the numerical implementation, the code predictions are first compared with analytical solutions, for a Newtonian fluid flowing through a cylindrical channel. Subsequently, the melt filling process of a non-Newtonian fluid (Cross-WLF) in a rectangular cavity with a cylindrical insert and in a tensile test specimen are studied. The predicted melt flow front interface and fields (pressure, velocity, and temperature) contours are found to be in good agreement with the reference solutions, obtained with the proprietary software M o l d e x 3 D ® . Additionally, the computational effort, measured by the elapsed wall-time of the simulations, is analyzed for both the open-source and proprietary software, and both are found to be similar for the same level of accuracy, when the parallelization capabilities of O p e n F O A M ® are employed.This work is funded by FEDER funds through the COMPETE 2020 Programme and National Funds through FCT (Portuguese Foundation for Science and Technology) under the projects UID-B/05256/2020, UID-P/05256/2020, MOLDPRO-Aproximações multi-escala para moldação por injeção de materiais plásticos (POCI-01-0145-FEDER-016665), and FAMEST-Footwear, Advanced Materials, Equipment’s and Software Technologies (POCI-01-0247-FEDER-024529)