A haptic-enabled multimodal interface for the planning of hip arthroplasty

Multimodal environments help fuse a diverse range of sensory modalities, which is particularly important when integrating the complex data involved in surgical preoperative planning. The authors apply a multimodal interface for preoperative planning of hip arthroplasty with a user interface that integrates immersive stereo displays and haptic modalities. This article overviews this multimodal application framework and discusses the benefits of incorporating the haptic modality in this area

A Procedure for Performing Nonlinear Pushover Analysis for Tsunami Loading to ASCE 7

The new ASCE 7-16 Chapter 6 offers a comprehensive and practical methodology for the design of structures for tsunami loads and effects. While it provides prescriptive tsunami loading and design requirements, Chapter 6 also allows for the use of performance-based nonlinear analysis tools. However, the specifics of load application protocol and system and component evaluation for such a nonlinear approach are not provided. This paper presents a procedure for performing nonlinear static pushover analysis for tsunami loading within the framework of the ASCE 7-16 standard. Through this approach, the user can both estimate the effective systemic lateral load-resisting capacity of a building and the local component demand. This enables the identification of deficiencies in structural elements with respect to the ASCE 7-16 standard acceptance criteria. To demonstrate the procedure, a prototypical reinforced concrete multistory building exposed to high tsunami hazard on the US Northwest Pacific Coast is assessed. This is a building with sufficient height to provide last-resort refuge for people having insufficient time to evacuate outside the inundation zone. The results of the nonlinear static pushover analyses show that the structural system has sufficient lateral strength to resist ASCE 7-16 prescribed tsunami loads, but fails the checks for component-based loading, with the exterior ground-story columns observed to fail in flexure and shear. The example demonstrates that use of the tsunami nonlinear static analysis procedure allows the identification of structural deficiencies such that a targeted strengthening of the building can be conducted (i.e., flexural and shear strengthening of the seaward and inland columns for the case study building presented), leading to significantly reduced costs

A nonlinear static procedure for the tsunami design of a reinforced concrete building to the ASCE7 Standard

New ASCE 7-16 Chapter 6 offer a comprehensive and practical methodology for the design of structures for tsunami loads and effects. While they provide prescriptive tsunami loading and design requirements, they also allow for the use of performance-based analysis tools. However, no guidance is provided as to how the performance-based analysis should be performed. This paper presents an improved nonlinear static pushover procedure for the assessment of the nonlinear capacity of structures to tsunami, within the framework of the ASCE 7-16 provisions. For this purpose, a prototypical reinforced concrete multi-storey building exposed to high tsunami hazard in the US Northwest Pacific coast is assessed. This is a building with sufficient height to provide last-resort refuge for people having insufficient time to evacuate outside the inundation zone. Two different tsunami load discretisation methods are applied to investigate the structural capacity under tsunami systemic and component loading, respectively. The results of the nonlinear static pushover analyses show that the structural system has sufficient lateral strength to resist ASCE 7-16 prescribed tsunami loads. However, when component-based loading is considered, the seaward ground storey columns are observed to fail in shear, precipitating structural failure. This is in agreement with the ASCE 7-16 simplified systemic acceptance criteria, i.e. that the structure is unsafe for use as a refuge, and that it would require significant strengthening. However, the use of the VDPO provides information of what needs to be strengthened in order to improve the tsunami performance of the structure

Design, Manufacture and Measurement of three Permanent Magnet Dipoles for FASER Experiment

FASER, the ForwArd Search ExpeRiment, is designed to search for new, yet undiscovered, light and weakly-interacting particles and study the interactions of high-energy neutrinos. Three dipoles, one 1.5 m-long and the other two 1.0 m-long each, installed upstream of the ATLAS experiment at CERN, are required to achieve sufficient separation of pairs of oppositely charged, high-energy Standard Model particles originating from decays of new physics particles. The dipoles have an aperture of 200 mm in diameter and a required magnetic field at the centre ≥ 0.55 T. Due to tight space constraints, a design based on permanent magnet technology was proposed. This paper describes the design, manufacturing, assembly and magnetic measurement of these large Halbach array dipoles

On the seismic design of one-story precast structures for P-Δ effects

P-Δ effects can reduce the seismic safety of structures under seismic actions and they can be vital for one-story precast buildings because of the large flexibility of columns. According to European building code, P-Δ effects can be taken into account by following some design requirements. Such requirements can significantly influence the design of the structures since they may provide the amplification of the seismic demand by means of the stability factor as well as the oversizing of the elements. This study investigates the influence of P-Δ effects on the seismic performance of precast one-story structures. An extensive parametric study is performed on one-story precast structures by varying some geometric features of the structure and the seismicity level of the site. Nonlinear dynamic analyses are performed by using Newmark’s method on all the case studies and the results of the first order and second order analysis are compared and discussed. Moreover, different design approaches are adopted in order to assess the Eurocode provisions for P-Δ effects. The results of the nonlinear dynamic analyses demonstrate that the overstrength, due to seismic detailing of columns and the materials overstrength, induces very low ductility demand for the structures. Indeed, even if P-Δ effects are totally neglected in the design phase, the overstrength due to other code prescriptions (e.g. minimum longitudinal reinforcement ratio) can still induce low ductility demand. Moreover it is demonstrated that the code prescriptions on P-Δ effects do not generally increase the structural safety and an alternative design approach is proposed, which gives both safer and cheaper structures than the ones currently designed according to Eurocodes

Time-resolved energy transfer from single chloride terminated nanocrystals to graphene

We examine the time-resolved resonance energy transfer of excitons from single n-butyl amine-bound, chloride-terminated nanocrystals to two-dimensional graphene through time-correlated single photon counting. The radiative biexponential lifetime kinetics and blinking statistics of the individual surface-modified nanocrystal elucidate the non-radiative decay channels. Blinking modification as well as a 4 times reduction in spontaneous emission were observed with the short chloride and n-butylamine ligands, probing the energy transfer pathways for the development of graphene-nanocrystal nanophotonic devices

Fragility functions for a reinforced concrete structure subjected to earthquake and tsunami in sequence

Many coastal regions lying on subduction zones are likely to experience the catastrophic effects of cascading earthquake and tsunami observed in recent events, e.g., 2011 Tohoku Earthquake and Tsunami. The influence of earthquake on the response of the structure to tsunami is difficult to quantify through damage observations from past events, since they only provide information on the combined effects of both perils. Hence, the use of analytical methodologies is fundamental. This paper investigates the response of a reinforced concrete frame subjected to realistic ground motion and tsunami inundation time histories that have been simulated considering a seismic source representative of the M9 2011 Tohoku earthquake event. The structure is analysed via nonlinear time-history analyses under (a) tsunami inundation only and (b) earthquake ground motion and tsunami inundation in sequence. Comparison of these analyses shows that there is a small impact of the preceding earthquake ground shaking on the tsunami fragility. The fragility curves constructed for the cascading hazards show less than 15% reduction in the median estimate of tsunami capacity compared to the fragility functions for tsunami only. This outcome reflects the fundamentally different response of the structure to the two perils: while the ground motion response of the structure is governed by its strength, ductility and stiffness, the tsunami performance of the structure is dominated by its strength. It is found that the ground shaking influences the tsunami displacement response of the considered structure due to the stiffness degradation induced in the ground motion cyclic response, but this effect decreases with increasing tsunami force

A cnidarian homologue of an insect gustatory receptor functions in developmental body patterning.

Insect gustatory and odorant receptors (GRs and ORs) form a superfamily of novel transmembrane proteins, which are expressed in chemosensory neurons that detect environmental stimuli. Here we identify homologues of GRs (Gustatory receptor-like (Grl) genes) in genomes across Protostomia, Deuterostomia and non-Bilateria. Surprisingly, two Grls in the cnidarian Nematostella vectensis, NvecGrl1 and NvecGrl2, are expressed early in development, in the blastula and gastrula, but not at later stages when a putative chemosensory organ forms. NvecGrl1 transcripts are detected around the aboral pole, considered the equivalent to the head-forming region of Bilateria. Morpholino-mediated knockdown of NvecGrl1 causes developmental patterning defects of this region, leading to animals lacking the apical sensory organ. A deuterostome Grl from the sea urchin Strongylocentrotus purpuratus displays similar patterns of developmental expression. These results reveal an early evolutionary origin of the insect chemosensory receptor family and raise the possibility that their ancestral role was in embryonic development