A quadtree-polygon-based scaled boundary finite element method for image-based mesoscale fracture modelling in concrete

A quadtree-polygon scaled boundary finite element-based approach for image-based modelling of concrete fracture at the mesoscale is developed. Digital images representing the two-phase mesostructure of concrete, which comprises of coarse aggregates and mortar are either generated using a take-and-place algorithm with a user-defined aggregate volume ratio or obtained from X-ray computed tomography as an input. The digital images are automatically discretised for analysis by applying a balanced quadtree decomposition in combination with a smoothing operation. The scaled boundary finite element method is applied to model the constituents in the concrete mesostructure. A quadtree formulation within the framework of the scaled boundary finite element method is advantageous in that the displacement compatibility between the cells are automatically preserved even in the presence of hanging nodes. Moreover, the geometric flexibility of the scaled boundary finite element method facilitates the use of arbitrary sided polygons, allowing better representation of the aggregate boundaries. The computational burden is significantly reduced as there are only finite number of cell types in a balanced quadtree mesh. The cells in the mesh are connected to each other using cohesive interface elements with appropriate softening laws to model the fracture of the mesostructure. Parametric studies are carried out on concrete specimens subjected to uniaxial tension to investigate the effects of various parameters e.g. aggregate size distribution, porosity and aggregate volume ratio on the fracture of concrete at the meso-scale. Mesoscale fracture of concrete specimens obtained from X-ray computed tomography scans are carried out to demonstrate its feasibility

The Indigenous Australian Human Papillomavirus (HPV) Cohort Study 2, Continuation for 5 to 10 Years: Protocol for a Longitudinal Study

Background: Human papillomavirus (HPV) infection, a common sexually transmitted disease, is associated with cancers of the cervix, vulva, vagina, penis, anus, and head and neck. Oropharyngeal squamous cell carcinoma (OPSCC; throat cancer) is a type of cancer involving the head and neck area that is rapidly increasing across the globe. There are higher rates of OPSCC among Indigenous populations relative to non–Indigenous Australian populations, although the HPV-attributable fraction remains unknown. For the first time at a global level, we plan to extend an Indigenous Australian adult cohort to monitor, screen, and ultimately prevent HPV-associated OPSCC and to undertake extensive cost-effectiveness modelling around HPV vaccination. Objective: This study aims to (1) extend follow-up to a minimum of 7 years post recruitment to describe the prevalence, incidence, clearance, and persistence of oral HPV infection; and (2) conduct clinical examinations of the head and neck, oral cavity, and oropharynx and collect saliva samples for early-stage OPSCC testing. Methods: We will continue to implement a longitudinal design for the next study phase, where we will ascertain the prevalence, incidence, clearance, and persistence of oral HPV infection at 48, 60, and 72 months; undertake clinical examinations/saliva assessments to detect early-stage OPSCC; and refer for treatment. The primary outcome measures are changes in oral HPV infection status, biomarker measures of early HPV-related cancer, and clinical evidence of early-stage OPSCC. Results: Participant 48-month follow-up will commence in January 2023. The first results are expected to be submitted for publication 1 year after 48-month follow-up begins. Conclusions: Our findings have potential to change the way in which OPSCC among Australian Indigenous adults is managed, with desired impacts including cost-savings on expensive cancer treatments; improved nutritional, social, and emotional outcomes; and improved quality of life for both Indigenous adults and the Indigenous community more broadly. Continuing a large, representative Indigenous adult cohort to track oral HPV infection and monitor early OPSCC is essential to yield critical information to include in the management armamentarium of health and well-being recommendations for Australia’s First Nations.Joanne Hedges, Sneha Sethi, Gail Garvey, Lisa J Whop, Karen Canfell, Zell Dodd, Priscilla Larkins, Annika Antonsson, Megan A Smith, Murthy Mittinty, Catherine Leane, Nicolas Reid, Eng H Ooi, Xiangqun Ju, Richard Logan, Lisa Jamieso

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Three-dimensional solution for acoustic and transport problems using the radial basis integral equation method

The radial basis integral equations method (RBIEM) has been applied for solution of three-dimensional (3D) acoustic and transport problems. The acoustic problem is often described using the Helmholtz equation, while the transport problems are usually described using the Laplace equation (diffusion only), the Poisson equation (diffusion with sources/sinks) and the convection–diffusion equation. The accuracy of the numerical scheme employing the first and second order Duchon splines augmented by first and second order polynomials, respectively, was examined. The effect of the number of interpolation points used in the radial basis function approximation on the condition number of the system was investigated. Numerical results obtained for the convection–diffusion equation were compared with the solutions obtained using the multi-domain dual reciprocity boundary element method (DRM-MD). The RBIEM formulation was found to be more accurate than the DRM-MD formulation. The implementation does not involve discretization over the boundaries of the subdomains used in the RBIEM formulation when evaluating the integral

Fatty acid modulation of antiestrogen action and antiestrogen-binding protein in cultured lymphoid cells

Experientia46101032-1037EXPE

Manuka honey sinus irrigations in recalcitrant chronic rhinosinusitis: phase 1 randomized, single-blinded, placebo-controlled trial

Abstract not availableMian Li Ooi, Arvind Jothin, Catherine Bennett, Eng H. Ooi, Sarah Vreugde, Alkis J. Psaltis and Peter-John Wormal

Targeting for carbon sequestration retrofit planning in the power generation sector for multi-period problems

Carbon constrained energy planning (CCEP) is useful to ensure that the CO2 emissions limit for a region is met through deployment of low-carbon technologies. The increased demand in energy consumption due to economic growth requires additional energy supply and generation which would subsequently increase the carbon emissions. Nevertheless, most countries are now committed to reduce carbon emission to achieve long term sustainability goals. However, the development of alternative energy sources or carbon capture and storage (CCS) initiatives for power plants entails major capital investments. This paper demonstrates how these issues may be handled using CCEP with insight- and optimisation-based targeting techniques for multi-period scenarios. Both approaches were developed recently for CCEP problems, but previous techniques were limited to single-period planning. The extensions to multi-period scenarios are demonstrated in this work with hypothetical illustrative examples, as well as a Malaysian case study. © 2013 Elsevier Ltd

The action of adenosine in relation to that of insulin on the low-K(m) cyclic AMP phosphodiesterase in rat adipocytes

Biochemical Journal2273815-821BIJO

Process integration approaches to optimal planning of unconventional gas field development

In recent years, the oil and gas industry has been moving to develop unconventional gas fields, which include those contaminated with high carbon dioxide (CO2) content. Typically, the CO2 has to be separated from the natural gas (NG) in offshore processing facilities (in situ) before the NG can be sent for processing at the gas plant onshore. To date, commercial-scale CO2 capture and storage (CCS) has proven to be viable mainly for CO2 that is separated from NG and subsequently injected at or near the gas field itself for permanent storage (CO2 sequestration) or utilized for the purpose of Enhanced Oil Recovery (EOR). In the case of multiple adjacent reservoirs exhibiting variations in NG quality and CO2 content, it may be necessary to have in situ CO2 removal using NG sweetening processes (e.g. membrane or amine absorption) to achieve a quality level such that the pooled NG streams meets the sales gas specification required for further processing at an onshore facility for sales. In this work, new process integration approaches are proposed to aid in the integrated planning of such joint field development projects, to rationalize the development of contaminated gas fields together with conventional sweet gas fields in meeting the required sales gas specifications of CO2 content. These approaches are based on analogous techniques previously developed for distributed effluent treatment systems and carbon capture planning for the power generation sector. A case study is used to illustrate how general insight-based policies for gas field development can be drawn from process integration perspectives. © 2016 Elsevier Ltd

An algebraic targeting approach for optimal planning of gas sweetening problem in non-conventional gas field development

An algebraic technique based on pinch analysis has been developed for the planning of non-conventional natural gas (NG) field development projects. The development of NG fields with high carbon dioxide (CO2) content has become increasingly common in the oil and gas industry. In such cases, the raw NG needs to be treated in situ for CO2 removal to meet the sales gas specifications before being sent to the onshore gas processing plants (GPPs). The captured CO2 can either be reinjected into the reservoir for permanent storage, or utilised for enhanced oil recovery (EOR), for which partial sequestration may also be achieved. These options create the need to develop systematic techniques to provide high-level decision support for field development planning. The algebraic technique developed in this work overcomes the limitations of a recently developed graphical technique (Foo et al., 2016), as it relaxes the previous simplistic assumptions on stream purity requirements. Two case studies are used to illustrate the methodology. © 2018 Institution of Chemical Engineer