SPH simulations of turbulence in fixed and rotating boxes in two dimensions with no-slip boundaries

In this paper we study decaying turbulence in fixed and rotating boxes in two dimen- sions using the particle method SPH. The boundaries are specified by boundary force particles, and the turbulence is initiated by a set of gaussian vortices. In the case of fixed boxes we recover the results of Clercx and his colleagues obtained using both a high accuracy spectral method and experiments. Our results for fixed boxes are also in close agreement with those of Monaghan1 and Robinson and Monaghan2 obtained using SPH. A feature of decaying turbulence in no-slip, square, fixed boundaries is that the angular momentum of the fluid varies with time because of the reaction on the fluid of the viscous stresses on the boundary. We find that when the box is allowed to rotate freely, so that the total angular momentum of box and fluid is constant, the change in the angular momentum of the fluid is a factor ~ 500 smaller than is the case for the fixed box, and the final vorticity distribution is different. We also simulate the behaviour of the turbulence when the box is forced to rotate with small and large Rossby number, and the turbulence is initiated by gaussian vortices as before. If the rotation of the box is maintained after the turbulence is initiated we find that in the rotating frame the decay of kinetic energy, enstrophy and the vortex structure is insensitive to the angular velocity of the box. On the other hand, If the box is allowed to rotate freely after the turbulence is initiated, the evolved vortex structure is completely different

Development of efficient micropropagation protocol for Withania coagulans (Stocks) Dunal

The present study describes the development of efficient micropropagation protocol for a commercially important medicinal plant Withania coagulans. Nodal segments were immersed in various concentrations of cefotaxime, viz 100, 250, 500 and 750 mgl-1 for 5 min and implanted on Murashige and Skoog medium (MS) medium fortified with 6-benzyladenine (BA) (2 to 4 mgl-1) or indolebutyric acid (IBA) (0.25 to 0.5 mgl-1) either alone or in combination with different concentrations. Of the four concentrations of cefotaxime tested, the 250 mgL-1 showed nonphytotoxic effect on cultures and completely eliminated bacterial infection. Direct multiple shoots differentiation occurred in cultured explants without intervening callus phase and the maximum number of shoots (7.2 ± 1.0 per explant) and elongation (7 ± 1.4 cm) were achieved on MS media containing 2 mgl-1 BA + 0.5 mgl-1 IBA. For induction of stout root system, the shoot buds were cultured on ½MS medium fortified with different concentrations of IBA (1 to 4 mgl-1), indole-3-acetic acid (IAA) (0.25 to 1.0 mgl-1) and kinetin (Kin) (1 to 2 mgl-1). MS medium with 2 mgl-1 IBA was found most effective for the induction of stout root system. Well-rooted plantlets were transferred to outside pots containing sterile soil, and sand mixture (2:1) showed 75% survival.Key words: In vitro, medicinal plant, propagation, Withania coagulans

Parametrised polyconvex hyperelasticity with physics-augmented neural networks

In the present work, neural networks are applied to formulate parametrised hyperelastic constitutive models. The models fulfill all common mechanical conditions of hyperelasticity by construction. In particular, partially input-convex neural network (pICNN) architectures are applied based on feed-forward neural networks. Receiving two different sets of input arguments, pICNNs are convex in one of them, while for the other, they represent arbitrary relationships which are not necessarily convex. In this way, the model can fulfill convexity conditions stemming from mechanical considerations without being too restrictive on the functional relationship in additional parameters, which may not necessarily be convex. Two different models are introduced, where one can represent arbitrary functional relationships in the additional parameters, while the other is monotonic in the additional parameters. As a first proof of concept, the model is calibrated to data generated with two differently parametrised analytical potentials, whereby three different pICNN architectures are investigated. In all cases, the proposed model shows excellent performance

Essential oil constituents and biological activities of leaf extracts of semenovia suffruticosa from Iran

Semenovia suffruticosa (Freyn et Bornm.) Manden. is one of the species of genus Semenovia (Apiaceae family). The essential oil of S. suffruticosa was obtained by hydrodistillation and analysed by gas chromatography coupled to mass spectrometry (GC/MS). The main components were cis-\uce\ub2-ocimene (12.9%), linalool (9.5%), \uce\ub3-terpinene (9.0%) and \uce\ub1-terpinolene (7.4%), representing the 38.8% of the oil. Antibacterial activity of S. suffruticosa ethanol, chloroform, ethyl acetate and aqueous leaf extracts was evaluated for the first time. The various extracts were tested by the disc-diffusion assay for antimicrobial activity against common animal and human infectious bacteria. Pseudomonas aeruginosa exhibited the highest sensitivity against the extracts, with a 13-15 mm zone of inhibition. Antiradical activity of S. suffruticosa ethanol, chloroform, ethyl acetate and aqueous leaf extracts was determined by DPPH (2,2-diphenyl-1-picrylhydrazyl) radical, FRAP (ferric reducing antioxidant power) and \uce\ub2-carotene/linoleic acid assays. Ethanol extract was the most powerful free radical scavenger in all these methods. These results, though preliminary, suggest that leaf extracts of S. suffruticosa exert promising antioxidant and antibacterial activities

A Meta-analysis on the Diagnostic Utility of Ultrasound in Pediatric Distal Forearm Fractures

Pediatric distal forearm fractures, comprising 30% of musculoskeletal injuries in children, are conventionally diagnosed using radiography. Ultrasound has emerged as a safer diagnostic tool, eliminating ionizing radiation, enabling bedside examinations with real-time imaging, and proving effective in non-hospital settings. The objective of this study is to evaluate the diagnostic efficacy of ultrasound for detecting distal forearm fractures in the pediatric population. A systematic review and meta-analysis were conducted through a comprehensive literature search in PubMed, Scopus, Web of Science, and Embase databases until October 1, 2023, following established guidelines. Eligible studies, reporting diagnostic accuracy measures of ultrasound in pediatric patients with distal forearm fractures, were included. Relevant data elements were extracted, and data analysis was performed. The analysis included 14 studies with 1377 patients, revealing pooled sensitivity and specificity of 94.5 (95% CI 92.7-95.9) and 93.5 (95% CI 89.6-96.0), respectively. Considering pre-test probabilities of 25%, 50%, and 75% for pediatric distal forearm fractures, positive post-test probabilities were 83%, 44%, and 98%, while negative post-test probabilities were 2%, 6%, and 15%, respectively. The bivariate model indicated significantly higher diagnostic accuracy in the subgroup with trained ultrasound performers vs. untrained performers (p = 0.03). Furthermore, diagnostic accuracy was significantly higher in the subgroup examining radius fractures vs. ulna fractures (p \u3c 0.001), while no significant differences were observed between 4-view and 6-view ultrasound subgroups or between radiologist ultrasound interpreters and non-radiologist interpreters. This study highlighted ultrasound\u27s reliability in detecting pediatric distal forearm fractures, emphasizing the crucial role of expertise in precisely confirming fractures through ultrasound examinations

Disparities in Computed Tomography Utilization for Pediatric Blunt Trauma: a Systematic Review and Meta-analysis Comparing Pediatric and Non-pediatric Trauma Centers

Pediatric blunt trauma is a major cause of morbidity and mortality, and computed tomography (CT) imaging is vital for accurate evaluation and management. Pediatric trauma centers (PTCs) have selective CT practices, while non-PTCs may differ, resulting in potential variations in CT utilization. The objective of this study is to delineate disparities in CT utilization for pediatric blunt trauma patients between PTCs and non-PTCs. A systematic review and meta-analysis were conducted following established guidelines, searching PubMed, Scopus, and Web of Science up to March 3, 2023. All studies examining CT utilization in the management of pediatric (aged \u3c 21 years) blunt trauma and specifying the type of trauma center(s) were included, and data were extracted and analyzed using STATA software version 17.0. An analysis of 30 studies revealed significant variations in CT scan utilization among pediatric blunt trauma patients across different types of trauma centers. PTCs exhibited lower pooled rates of abdominopelvic CT scans (35.4% vs. 44.9%, p \u3c 0.01), cranial CT scans (36.9% vs. 42.9%, p \u3c 0.01), chest CT scans (14.5% vs. 25.4%, p \u3c 0.01), and cervical spine CT scans (23% vs. 45%, p \u3c 0.01) compared to adult or mixed trauma centers (ATCs/MTCs). PTCs had a pooled rate of 54% for receiving at least one CT scan, while ATCs/MTCs had a higher rate of 69.3% (p \u3c 0.05). The studies demonstrated considerable heterogeneity. These findings underscore the need to conduct further research to understand the reasons for the observed variations and to promote appropriate imaging usage, minimize radiation exposure, and encourage collaboration between pediatric and adult trauma centers

Microwave studies of the fractional Josephson effect in HgTe-based Josephson junctions

The rise of topological phases of matter is strongly connected to their potential to host Majorana bound states, a powerful ingredient in the search for a robust, topologically protected, quantum information processing. In order to produce such states, a method of choice is to induce superconductivity in topological insulators. The engineering of the interplay between superconductivity and the electronic properties of a topological insulator is a challenging task and it is consequently very important to understand the physics of simple superconducting devices such as Josephson junctions, in which new topological properties are expected to emerge. In this article, we review recent experiments investigating topological superconductivity in topological insulators, using microwave excitation and detection techniques. More precisely, we have fabricated and studied topological Josephson junctions made of HgTe weak links in contact with two Al or Nb contacts. In such devices, we have observed two signatures of the fractional Josephson effect, which is expected to emerge from topologically-protected gapless Andreev bound states. We first recall the theoretical background on topological Josephson junctions, then move to the experimental observations. Then, we assess the topological origin of the observed features and conclude with an outlook towards more advanced microwave spectroscopy experiments, currently under development.Comment: Lectures given at the San Sebastian Topological Matter School 2017, published in "Topological Matter. Springer Series in Solid-State Sciences, vol 190. Springer

RF characterisation of new coatings for future circular collider beam screens

For the future high energy colliders being under the design at this moment, the choice of a low surface impedance beam screen coating material has become of fundamental importance to ensure sufficiently low beam impedance and consequently guaranteed stable operation at high currents. We have studied the use of high-temperature superconducting coated conductors as possible coating materials for the beam screen of the FCC-hh. In addition, amorphous carbon coating and laser-based surface treatment techniques are effective surface treatments to lower the secondary electron yield and minimise the electron cloud build-up. We have developed and adapted different experimental setups based on resonating structures at frequencies below 10 GHz to study the response of these coatings and their modified surfaces under the influence of RF fields and DC magnetic fields up to 9¿T. Taking the FCC-hh as a reference, we will show that the surface resistance for REBCO-CCs is much lower than that of Cu. Further we show that the additional surface modifications can be optimised to minimise their impact on the surface impedance. Results from selected coatings will be presented.Work supported by CERN under Grants FCC-GOV-CC-0210 (KE4945/ATS), FCC-GOV-CC-0209 (KE4946/ATS) and FCC-GOV-CC0208 (KE4947/ATS). ICMAB funding through RTI2018-095853-B-C21 SuMaTe from MICINN and co-financing by the European Regional Development Fund, 2017-SGR 1519 from Generalitat de Catalunya, and COST Action NANOCO-HYBRI (CA16218) from EU, the Center of Excellence award Severo Ochoa CEX2019-000917-S. UPC funding through the Unit of Excellence Maria de Maetzu MDM2016-0600. N. Tagdulang and A. Romanov acknowledge MSCA-COFUND-2016-754397 for the PhD grant.Peer ReviewedPostprint (published version