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Measuring Relative Component Motion and Stability in Total Hip Replacements Using a Magnetic Position and Orientation Sensing System
Get PDFAn instrumented total hip replacement (THR) implant capable of remote and continuous monitoring would be an attractive prospect for a surgeon to conveniently track the recovery of their patients. Measuring the relative motion of the prosthesis components would provide insight into joint kinematics and contribute to the detection of adverse events including impingement and subluxation. The aim of this study was to develop a sensing system to measure the relative orientation and translation of the prosthesis components. A tri-axis magnetometer and a permanent magnet were integrated into clinically available THR components, forming a magnetic position and orientation sensing system. A robotic arm was used to articulate the components through controlled motion routines and record the orientation of the components. The output of the robot arm and a camera tracking system were used to validate the performance of the sensing system. The sensing system measured the relative orientation of the components to two degrees of freedom with an RMSE of <4.0° and measured the displacement of the femoral head during an impingement-driven subluxation motion with an RMSE of 0.2 mm. This proof-of-concept work has shown that magnetic sensing technology can track the position and orientation of THR components. With further development, this sensing method could feature within an instrumented THR implant
A review of industrial pumps for viscous and non-Newtonian slurry transport
Get PDFThis paper presents a concise review of industrial pumps for viscous and non-Newtonian slurry transport. It combines both the computational fluid dynamics (CFD) and experimental analysis to investigate the performance and limitations of various rotodynamic and positive displacement (PD) pumps for various slurry transport applications. The factors influencing head, efficiency and reliability in rotodynamic and PD pumps were evaluated for viscous and non-Newtonian fluids applications. Available literature showed that centrifugal pumps experience head losses of ≥ 8 m and efficiency reduction of 20 % when viscosity approaches 800–1000 cP, whereas the blade and volute optimisation could improve the overall efficiency. The performance of the multiphase pump showed a sharp decline when handling non-Newtonian fluids, primarily due to the formation of complex vortex structures and tip‑leakages. This study also highlighted key geometric parameters for optimisation to improve overall performance and enable the integration of multiphase pumps as a prime mover in a jet pump system, for a robust handling of highly viscous and solid‑laden fluids. While the special‑effect jet pumps had lower peak efficiencies compared to other rotodynamic pumps, robustness and passability for abrasive and multiphase flows were demonstrated, achieving up to 40 % efficiency in sand slurry applications. PD pumps, such as the reciprocating plunger and diaphragm designs, exhibited the highest viscosity tolerance, however, their performance was limited by valve response and mechanical complexity. This review particularly focused on the capabilities of Tesla disc pump for handling highly viscous and abrasive fluids. Literature on Tesla disc pumps emphasised that geometric optimisation of the disc impeller, combined with the use of a dedicated volute, could significantly enhance its efficiency and position it as a complementary solution to both centrifugal and PD pumps. The analysis of life cycle cost (LCC) showed that the Tesla disc pump maintained moderate costs for harsh applications, indicating a sustainable operational life cycle
Investigating the Bio-orthogonality of Isocyanides
No full textIsocyanides have been applied in bio-orthogonal reactions as triggers for uncaging reactions. However, emerging evidence suggests that they may label proteins covalently and are not bio-orthogonal.1 We synthesized a fluorophore-bound isocyanide and analysed its protein reactivity. Our results suggest that isocyanides cannot be considered to be bio-orthogonal in chemical biology
AMPLE: An adaptive multiple path loss exponent radio propagation model considering environmental factors
Get PDFWe present AMPLE - a novel multiple path loss exponent (PLE) radio propagation model that can adapt to different environmental factors. In the proposed model, the scenario under consideration is classified into region types from a raster map, and each type of region is assigned with a PLE. The path loss is then computed based on a straight line between the transmitter (Tx) and receiver (Rx), which records the intersected regions and the weighted region path loss. To regress the model, those PLEs are extracted via measurement and the region map. We also verify the model in two suburban areas and compare with the 3GPP path loss model and the Alpha-Beta-Gamma (ABG) model. The results show that the AMPLE model outperforms the aforementioned models. To the best of our knowledge, this is the first time that a practical multi-slope model precisely maps PLEs and region types. Besides, this model can be integrated into map systems by creating a new path loss attribute for digital maps
Seismic resilience analysis of high-speed railway tunnels across fault zones using ensemble learning approach
Get PDFSevere damage to the Daliang high-speed railway tunnel during earthquakes primarily results from the dynamic interplay between fault dislocation and intense seismic forces near fault lines, accompanied by their complex feedback mechanisms. This study introduces a novel hybrid finite element model to explore the impact of fault dislocation-induced earthquakes on tunnel lining integrity. The influence of seismic characteristics on factors such as peak ground acceleration, tunnel structure form, and the shear modulus of surrounding rock is analyzed. Extensive numerical simulations investigate the coupling effects of faults and various seismic motions on tunnel structures. Additionally, a rapid resilience assessment model for tunnels crossing strike-slip faults is developed using the Adaboost algorithm. This model evaluates the seismic fragility and resilience of such tunnels, offering insights into the anti-seismic behaviors of three distinct tunnel lining configurations under the combined stresses of fault dislocation and significant seismic activity. Furthermore, the fault damage characteristics of the crossing-fault high-speed railway tunnel are assessed, based on real earthquake damage classification and current seismic codes. Findings demonstrate that the evaluation model is both highly accurate and efficient, serving as an effective alternative to traditional nonlinear time-history analysis of tunnel structures. Research shows that critical factors influencing seismic fragility and resilience include the structural design of the tunnel, shear modulus of the surrounding rock, peak ground acceleration, and tunnel height. Simulations reveal that tensile and compressive damage are significantly reduced in circular tunnels with a shock-absorbing joint compared to original tunnel prototypes. Overall, damage assessments from actual faults in crossing-fault high-speed railway tunnels correlate well with numerical predictions, providing essential references for structural recovery and safety evaluations post-earthquake
The Contribution of Volume Change in Preserving High-P Metastable Assemblages
Get PDFIncomplete retrograde reaction of sodic–calcic pyroxene occurred during the exhumation of Eocene eclogite and blueschist in NE New Caledonia. Sodic–calcic pyroxene is well-preserved in reaction relationships with paragonite and structurally late albite, in conflict with the prediction that it should transform efficiently during decompression to albite, paragonite, glaucophane and quartz. The microstructural distribution of albite accompanying crenulation cleavage development is consistent with albite growth having been restricted by space-filling requirements. In contrast, domains of high strain enable the accommodation of volume and fluid infiltration, increasing the size of the equilibration volume leading to the complete conversion of sodic–calcic clinopyroxene to albite. Despite decompression-driven dehydration, limited volume accommodation presents a plausible mechanism to metastably preserve high-P (up to 18 kbar) sodic–calcic clinopyroxene-bearing assemblages to lower-P conditions (~10 kbar) that should stabilise albite. Efficient retrogression is facilitated by dynamic recrystallisation inducing dilation
Design of low-power vertical-axis wind turbine based on parametric method
Get PDFThe parametric design of a low-power (<1 kW) H-type vertical-axis wind turbine tailored to the wind conditions of the Yucatán Peninsula is presented. Nine airfoils were evaluated using the Double Multiple Streamtube method and Qblade Lifting-Line Theory numerical simulations, considering variations in solidity (σ = 0.20–0.30), aspect ratio (Ar = H/R = 2.6–3.0), number of blades (2–5), and a swept-area constraint of 4 m2. The parametric study shows that fewer blades increase Cp, although a three-blade rotor improves start-up torque, vibration mitigation, and load smoothing. The recommended configuration—three blades, Ar = 2.6, σ = 0.30 and S1046 (or NACA 0018) operated near λ ≈ 3.75—balances efficiency and start-up performance. For the representative mean wind velocity of 5 m/s, typical of the Yucatán Peninsula, the VAWT achieves a maximum output of 136 W at 220 rpm. Under higher-wind conditions observed in specific sites within the region, the predicted maximum output increases to 932 W at 380 rpm
Co-production with marginalised workers: working with homecare workers and managers caring for people approaching end-of-life
Get PDFBackground
Co-production is important due to its effectiveness in creating relevant and meaningful outputs for use in social and healthcare practice, however, frontline staff such as homecare workers (also known as aides, personal assistants or domiciliary care workers providing paid care within the home) are a key group within the social care workforce who are under-represented in this approach. Here, we report our coproduction process engaging with this workforce to develop training resources for workers providing end-of-life homecare.
Aim
To co-produce training resources with homecare workers and their managers to support and educate workers delivering end-of-life homecare using evidence from our larger qualitative interview study.
Methods
We conducted a series of 12 co-production workshops with UK-based homecare workers and managers (partners) to design training resources and recommendations for homecare providers informed by research findings. We adopted the five key principles of co-production: Sharing of power; Including all perspectives and skills; Respecting and valuing knowledge; Reciprocity; and Building and maintaining relationships. A co-production advisory group of homecare workers as well as the workshop partners gave valuable oversight throughout the workshop series.
Results
77 partners (31 homecare workers, 46 managers) participated in 12 workshops (one face-to-face; 11 online). Our approach enabled power-sharing, inclusivity, respect, collaboration and reciprocity, relationship-building, and identification of effective flexible approaches to co-production. Specific forms of training resources were co-created. Training recommendations (content, delivery formats, access during working hours, etc.) were also developed together. Challenges were non-attendance and lack of engagement by some partners during sessions.
Conclusion
These workshops are the first, to our knowledge, to successfully co-produce end-of-life care training resources with homecare workers and managers, a poorly represented workforce in co-production. Challenges included inconsistent attendance and poor engagement by a minority of partners. The five key principles of co-production enabled true engagement with the process, thereby enriching the final outputs
Parent’s reflections on the impacts of the UK’s ‘hostile environment’ policies on young asylum-seeking and refugee children
Get PDFThe need to shield young children from adversity is well documented, and reflected in both UK policy and the current UK Labour government’s pledge to ‘set every child up for the best start in life’. Yet, conversely, the UK operationalises a raft of measures to create a ‘hostile environment’ for asylum seekers and refugees. The hostile environment policies force asylum-seeking and refugee children to endure poverty and insecurity, associated with negative consequences for children’s physical, social, emotional and educational development. This paper employs critical phenomenology to understand the material, psychological and phenomenological effects of the ‘hostile environment’ on young asylum-seeking and refugee children in the UK. Data is drawn from semi-structured interviews with parents from 11 asylum-seeking and refugee families with young children (0–8). The findings reveal that asylum-seeking children are forced to live in conditions of material adversity and a state of limbo characterised by insecurity that pervades all aspects of their lives. Refugees have more stability than asylum seekers, but the psychological and phenomenological effects of living under hostile environment conditions continue to persist. The parents in this study expressed how they felt the cumulative effects of material adversity and insecurity negatively influenced their mental state and negatively impacted their children. As such, this paper indicates the contradiction between these negative effects of the hostile environment and the ‘best start in life’ for young children that the previous and current UK Governments ostensibly support. The paper is timely as the 2024 election of the new Labour Government presents a significant opportunity to influence policy responses to asylum seekers
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