Multilayered folding with voids

In the deformation of layered materials such as geological strata, or stacks of paper, mechanical properties compete with the geometry of layering. Smooth, rounded corners lead to voids between the layers, while close packing of the layers results in geometrically-induced curvature singularities. When voids are penalized by external pressure, the system is forced to trade off these competing effects, leading to sometimes striking periodic patterns. In this paper we construct a simple model of geometrically nonlinear multi-layered structures under axial loading and pressure confinement, with non-interpenetration conditions separating the layers. Energy minimizers are characterized as solutions of a set of fourth-order nonlinear differential equations with contact-force Lagrange multipliers, or equivalently of a fourth-order free-boundary problem. We numerically investigate the solutions of this free boundary problem, and compare them with the periodic solutions observed experimentally

Game prototype for understanding safety issues of life boat launching process.

Novel advanced game techniques provide us with new possibilities to mimic a complicated training process, with the benefit of safety enhancement. In this paper, we design and implement a 3D game which imitates the lifeboat launching process. Lifeboat launching is such a complex but vital process which can on one side saving people's life on sea and on the other side associating many potential hazards. It involves both the tractor manoeuvres and boat operations. The primary objective of the game is to allow novices to better understand the sequence of the operations in launching process and manager the potential hazards happening during the launching. There is also great educational significance with the promotion of the game to the general public for enhanced awareness of safety issues. The key modules of the game are designed based on physical simulation which gives the players enhanced plausible cognition and enjoyable interaction

Mass transport in PEM water electrolysers: A review

While hydrogen generation by alkaline water electrolysis is a well-established, mature technology and currently the lowest capital cost electrolyser option; polymer electrolyte membrane water electrolysers (PEMWEs) have made major advances in terms of cost, efficiency, and durability, and the installed capacity is growing rapidly. This makes the technology a promising candidate for large-scale hydrogen production, and especially for energy storage in conjunction with renewable energy sources – an application for which PEMWEs offer inherent advantages over alkaline electrolysis. Improvements in PEMWE technology have led to increasingly high operational current densities, which requires adequate mass transport strategies to ensure sufficient supply of reactant and removal of products. This review discusses the current knowledge related to mass transport and its characterisation/diagnosis for PEMWEs, considering the flow channels, liquid-gas diffusion layer, and polymer electrolyte membrane in particular

High dose, dose-intensive chemotherapy with doxorubicin and cyclophosphamide for the treatment of advanced breast cancer.

Eighteen patients with advanced breast cancer were commenced on treatment with high dose doxorubicin (100 mg m-2) or doxorubicin (100 mg m-2) and cyclophosphamide (500 mg m-2) at 2 weekly intervals. Three cycles of treatment were planned. rG-CSF was given subcutaneously for 10 days, starting 24 h after each cycle of chemotherapy. Sixteen out of 18 patients responded (89%) of whom six (33%) achieved a complete remission. Twelve (67%) completed the three planned cycles, four (22%) received two cycles and two (11%) received one cycle only. The median time to progression was 5 1/2 months and the median survival was 18 1/2 months. Neutropenia occurred after 89% of courses and 65% of courses were accompanied by a significant (WHO grade III or IV) infection. The duration of neutropenia was short (mean 5.4 days) and mean time to absolute neutrophil count recovery (ANC > 1,000 x 10(6) litre) from the start of treatment was 11 days. Moderate to severe epithelial toxicity (WHO grade 3 or 4) accompanied 43% of courses and was dose limiting. Conclusion: High dose, dose intensive chemotherapy has an excellent initial therapeutic effect in advanced breast cancer but does not prolong duration of remission or overall survival beyond that of standard treatment. Although subcutaneous rG-CSF curtailed the expected duration of neutropenia substantially, the overall incidence of neutropenia and of infections requiring intravenous antibiotics was high. Furthermore, almost half of the courses were complicated by moderate to severe oral mucositis and/or mild to moderate palmar and plantar inflammation. The lack of survival benefit and excess toxicity seriously limits the wider application of this regime. It should not be used in place of standard dose palliative chemotherapy for metastatic breast cancer

A probabilistic peridynamic framework with an application to the study of the statistical size effect

This is the final version. Available from Elsevier via the DOI in this record. Data availability: No data was used for the research described in the article.The high computational expense of peridynamic models remains a major limitation, hindering ‘outer-loop’ applications that require a large number of simulations, for example, uncertainty quantification. This contribution presents a framework that makes such computations feasible. By employing a Multilevel Monte Carlo framework, where the majority of simulations are performed using a coarse mesh, and performing relatively few simulations using a fine mesh, a significant reduction in computational cost can be realised, and statistics of structural failure can be estimated. The maximum observed speed-up factor is 16 when compared to a standard Monte Carlo estimator, thus enabling the efficient forward propagation of uncertain parameters in a computationally expensive peridynamic model. Furthermore, the multilevel method provides an estimate of both the discretisation error and sampling error, thereby improving confidence in numerical predictions. The performance of the approach is demonstrated through an examination of the statistical size effect in quasi-brittle materials.Turing Fellowshi

Open-circuit dissolution of platinum from the cathode in polymer electrolyte membrane water electrolysers

Platinum is the state-of-the-art catalyst for hydrogen evolution in polymer electrolyte membrane (PEM) water electrolysers; however, its stability has only been characterized to a limited extent in situ. This study measures platinum dissolving from the cathode during intermittent operation of a 3-electrode PEM electrolyser cell, using a differential pulse voltammetry technique that provided detection limits for platinum of less than 2 ng L−1. Water samples were periodically taken during on-off current cycling, and during periods of open-circuit voltage (OCV) platinum dissolution was detected when the cathode potential rose above 0.85 V NHE due to diffusion of oxygen from the anode. This reached a maximum dissolution rate at the highest cathode potential of 1.02 V NHE, and gradually decayed over a 90 h period. The average total amount of platinum dissolved per 90 h OCV period was estimated to be 152 ng cm−2 or 0.005% of the initial electrode catalyst mass. The dissolution mechanism was predicted to be the same as that occurring in PEM fuel cell cathodes, although being kinetically hindered in PEM electrolysers by the slow diffusion of oxygen from the anode to the cathode

Oxygen evolution catalysts under proton exchange membrane conditions in a conventional three electrode cell vs. electrolyser device: a comparison study and a 3D-printed electrolyser for academic labs dagger

Developing active and stable oxygen evolution reaction (OER) catalysts that can operate in electrolyser environments is of utmost important in order to produce H2 gas for electricity generation. Currently in academia, many of these studies are carried out in conventional three-electrode cell set-ups; however, this configuration may not accurately represent conditions experienced under practical electrolyser conditions. Herein, a range of transition metal oxide (TMO) catalysts are evaluated and compared in a three-electrode cell and in an electrolyser. We show that the same catalyst significantly underperforms in a three-electrode cell. Hence, many OER catalysts in academic labs may have been erroneously omitted from further optimisation processes due to showing ‘poor’ performance in conventional three-electrode cells. Herein, we wish to show this discrepancy experimentally and suggest a solution to scientists wanting to find active OER catalysts by using 3D-printing to inexpensively manufacture electrolyser devices for OER catalyst evaluation

Shared understanding in psychiatrist–patient communication: Association with treatment adherence in schizophrenia

Objective Effective doctor–patient communication, including a shared understanding, is associated with treatment adherence across medicine. However, communication is affected by a diagnosis of schizophrenia and reaching a shared understanding can be challenging. During conversation, people detect and deal with possible misunderstanding using a conversational process called repair. This study tested the hypothesis that more frequent repair in psychiatrist–patient communication is associated with better treatment adherence in schizophrenia. Methods Routine psychiatric consultations involving patients with (DSM-IV) schizophrenia or schizoaffective disorder were audio-visually recorded. Consultations were coded for repair and patients’ symptoms and insight assessed. Adherence was assessed six months later. A principal components analysis reduced the repair data for further analysis. Random effects models examined the association between repair and adherence, adjusting for symptoms, consultation length and the amount patients spoke. Results 138 consultations were recorded, 118 were followed up. Patients requesting clarification of the psychiatrist's talk and the clarification provided by the psychiatrist was associated with adherence six months later (OR 5.82, 95% CI 1.31–25.82, p = 0.02). Conclusion The quality of doctor–patient communication also appears to influence adherence in schizophrenia. Practice implications Future research should investigate how patient clarification can be encouraged among patients and facilitated by psychiatrists’ communication

Acoustic time-of-flight imaging of polymer electrolyte membrane water electrolysers to probe internal structure and flow characteristics

Acoustic time-of-flight (AToF) imaging has been demonstrated as a low-cost, rapid, non-destructive, operando tool to characterize processes in the flow channels and liquid-gas diffusion layer (LGDL) of polymer electrolyte membrane water electrolysers (PEMWEs). An array of 64 piezoelectric sensors was used, with all sensors emitting input pulses and detecting the acoustic wave reflected by the sample (pulse-echo mode). The shape and intensity of this reflected waveform depends on the ratio of reflection and transmission at phase interfaces and is strongly affected by resonant scattering of acoustic waves by gas bubbles. This AToF imaging technique was deployed to produce reflection intensity maps of the anode flow-field and LGDL; by measuring the AToF response for current densities ranging from 0.00 A cm−2 to 2.00 A cm−2, a close correlation was found between the acoustic attenuation in the flow-field and the production and removal of oxygen gas through the flow channels. Furthermore, a close link between the AToF response and water thickness in the LGDL was demonstrated, as supported by literature data. The application of the AToF technique has been established as a novel way of investigating PEMWE operation and as an alternative to more complex imaging techniques such as neutron imaging