Dynamic testing of complex structures

Response of structure is determined under impulses large enough to create severe strains. Electrodynamic shaker can provide impulses to nearly any point on structure and can deliver repeated pulses of varying force and duration

Mathematical modelling with experimental validation of viscoelastic properties in non-Newtonian fluids

The paper proposes a mathematical framework for the use of fractional-order impedance models to capture fluid mechanics properties in frequency-domain experimental datasets. An overview of non-Newtonian (NN) fluid classification is given as to motivate the use of fractional-order models as natural solutions to capture fluid dynamics. Four classes of fluids are tested: oil, sugar, detergent and liquid soap. Three nonlinear identification methods are used to fit the model: nonlinear least squares, genetic algorithms and particle swarm optimization. The model identification results obtained from experimental datasets suggest the proposed model is useful to characterize various degree of viscoelasticity in NN fluids. The advantage of the proposed model is that it is compact, while capturing the fluid properties and can be identified in real-time for further use in prediction or control applications. This article is part of the theme issue 'Advanced materials modelling via fractional calculus: challenges and perspectives'

Different fractional order models for an experimental smart beam system

The applicability of fractional calculus in system engineering outperforms classic identification techniques due to its ability to depict physical phenomena with increased accuracy. The present study explores the increased accuracy and flexibility of a fractional order model applied to an experimental smart beam depicting an airplane wing. The paper details the fractional order system identification of the beam and explores the possibility of realization of the model

Ovotestis in Adolescence: 2 Case Reports

We present 2 patients found to have ovotesticular disorder of sexual development (otDSD) in late adolescence. Two 15-year-old phenotypically male patients presented to a large pediatric hospital with different complaints: 1 with concern for testicular rupture after a straddle injury; 1 with gynecomastia. Further workup, including imaging and laboratory tests, was performed before surgical exploration. The first patient had unilateral ovotestis, contralateral testis, and SRY-negative 46,XX karyotype. The second patient with gynecomastia had unilateral ovotestis with hemi-uterus and fallopian tube, contralateral ovarian tissue, and 46,XX/47,XXY Klinefelter mosaic karyotype. Although rare, phenotypically normal male patients may present later with ovotesticular disorder of sexual development

Bicuspid Aortic Valve Morphology and Outcomes After Transcatheter Aortic Valve Replacement

BACKGROUND Bicuspid aortic stenosis accounts for almost 50% of patients undergoing surgical aortic valve replacement in the younger patients. Expanding the indication of transcatheter aortic valve replacement (TAVR) toward lower-risk and younger populations will lead to increased use of TAVR for patients with bicuspid aortic valve (BAV) stenosis despite the exclusion of bicuspid anatomy in all pivotal clinical trials.OBJECTIVES This study sought to evaluate the association of BAV morphology and outcomes of TAVR with the new-generation devices.METHODS Patients with BAV confirmed by central core laboratory computed tomography (CT) analysis were included from the international multicenter BAV TAVR registry. BAV morphology including the number of raphe, calcification grade in raphe, and leaflet calcium volume were assessed with CT analysis in a masked fashion. Primary outcomes were all-cause mortality at 1 and 2 years, and secondary outcomes included 30-day major endpoints and procedural complications.RESULTS A total of 1,034 CT-confirmed BAV patients with a mean age of 74.7 years and Society of Thoracic Surgeons score of 3.7% underwent TAVR with contemporary devices (n = 740 with Sapien 3; n = 188 with Evolut R/Pro; n = 106 with others). All-cause 30-day, 1-year, and 2-year mortality was 2.0%, 6.7%, and 12.5%, respectively. Multivariable analysis identified calcified raphe and excess leaflet calcification (defined as more than median calcium volume) as independent predictors of 2-year all-cause mortality. Both calcified raphe plus excess leaflet calcification were found in 269 patients (26.0%), and they had significantly higher 2-year all-cause mortality than those with 1 or none of these morphological features (25.7% vs. 9.5% vs. 5.9%; log-rank p < 0.001). Patients with both morpho-logical features had higher rates of aortic root injury (p < 0.001), moderate-to-severe paravalvular regurgitation (p = 0.002), and 30-day mortality (p = 0.016).CONCLUSIONS Outcomes of TAVR in bicuspid aortic stenosis depend on valve morphology. Calcified raphe and excess leaflet calcification were associated with increased risk of procedural complications and midterm mortality. (c) 2020 by the American College of Cardiology Foundation.Cardiolog