23 research outputs found

    Large plate monitoring using guided ultrasonic waves

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    Areas of stress concentration around welded structures are likely to lead to fatigue cracks and corrosion pitting during the life time of technical machinery. Performing periodical non-destructive testing of the critical area is crucial for the maintenance of structural integrity and the prevention of unforeseen shutdowns of the system. Low frequency guided ultrasonic waves can propagate along thin structures and allow for the efficient testing of large components. Structural damage can be localized using a distributed array of guided ultrasonic wave sensors. Guided waves might be employed to overcome the accessibility problem for stiffened plate structures where access to some parts of the inspected structure is not possible. The transmission and reflection of the A0 Lamb wave mode for a variation of the stiffener geometry and excitation frequency was investigated numerically and verified experimentally. The dispersive behaviour of the guided waves has been studied to ascertain a frequency thickness product that provides limited pulse distortion. The limitations of the plate geometry as well as the excitation and monitoring locations were discussed. The radial spreading of the incident, transmitted and reflected waves from a stiffener has been investigated. The efficient quantification of the transmitted and reflected waves from the stiffener for a wide range of angles has been obtained from a single Finite Element model containing two parallel lines of nodes in front of and past the stiffener. The research outcomes have shown the dependency of the scattered wave on the incident angle and stiffener dimensions. Reasonably good A0 wave mode transmission was obtained from the oblique wave propagation (up to an angle of 45o) across realistic stiffener geometries. The choice of an optimum excitation frequency, which can ensure maximum transmission across the stiffener for specific plate geometry, was recommended. The ability for defect detection in inaccessible areas has been investigated numerically and validated experimentally. The possibility of detecting and characterizing the reflection of a guided wave pulse (A0 mode) from a through-thickness notch located behind the stiffener has been discussed. Two different approaches, based on the access to the sides of the stiffener on the plate, were employed. The limitations of the detectable defect size and location behind the stiffener have been investigated. The energy of the transmitted wave across the stiffener was adequate to detect simulated damage behind the stiffener. The evaluation has shown that defect detection in inaccessible areas behind stiffeners is achievable if the signal-to-noise ratio is high enough. In experimental measurements the noise level was of similar magnitude to the observed reflections at the defect. Thus, there is necessity to enhance the signal-to-noise ratio in experimental measurements

    Pharmacy

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    This chapter concentrates on community pharmacy and General Practice pharmacist issues. Prescribing issues are covered in Chapter 7. The starting case highlights the anticholinergic burden of drugs and the role of community (and practice) pharmacists in identifying interactions.The size of primary care prescribing (75% of NHS medications) means that this is a key carbon (as well as quality of life and cost) issue when estimates suggest that 10% of medications are unnecessary. The overlap between current good practice and sustainability agendas suggests the importance of weaving sustainability into stories about how to take medications. The role of pharmacists in clinical consultations and reviews, and their use of guides and use of technology to maximise their effectiveness is reviewed.The importance of effective prescribing management systems for repeats or after-hospital care is highlighted. Centre for Sustainable Healthcare’s four principles of sustainable health care suggest how community pharmacies can be better at preventing illness (lifestyle inputs and green social prescribing), empowering patients (personalised care and sick-day rules, multi-compartment compliance aids, medicines disposal, and antimicrobial resistance), designing and delivering leaner service (paperless prescribing, stock management, collection checks) and offering low carbon alternatives (e.g., liquid medication alternatives).Toolkits for greener pharmacy are introduced, and the chapter addresses the importance of pharmacy education programmes, as well as acknowledges the barriers to sustainable pharmacy practice

    Improving Antimicrobial Use to Protect the Environment: What Is the Role of Infection Specialists?

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    Anthropogenic environmental changes are causing severe damage to the natural and social systems on which human health depends. The environmental impacts of the manufacture, use, and disposal of antimicrobials cannot be underestimated. This article explores the meaning of environmental sustainability and four sustainability principles (prevention, patient engagement, lean service delivery, and low carbon alternatives) that infection specialists can apply to support environmental sustainability in health systems. To prevent inappropriate use of antimicrobials and consequent antimicrobial resistance (AMR) requires international, national, and local surveillance plans and action supporting antimicrobial stewardship (AMS). Engaging patients in addressing environmental sustainability, for example through public awareness campaigns about the appropriate disposal of unused and expired antimicrobials, could drive environmentally sustainable changes. Streamlining service delivery may include using innovative methods such as C-reactive protein (CRP), procalcitonin (PCT), or genotype-guided point of care testing (POCT) to reduce unnecessary antimicrobial prescribing and risk of adverse effects. Infection specialists can assess and advise on lower carbon alternatives such as choosing oral (PO) over intravenous (IV) antimicrobials where clinically appropriate. By applying sustainability principles, infection specialists can promote the effective use of healthcare resources, improve care quality, protect the environment, and prevent harm to current and future generations

    Review of Evidence for Adult Diabetic Ketoacidosis Management Protocols

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    BACKGROUND: Diabetic ketoacidosis (DKA) is an endocrine emergency with associated risk of morbidity and mortality. Despite this, DKA management lacks strong evidence due to the absence of large randomised controlled trials (RCTs). OBJECTIVE: To review existing studies investigating inpatient DKA management in adults, focusing on intravenous (IV) fluids; insulin administration; potassium, bicarbonate, and phosphate replacement; and DKA management protocols and impact of DKA resolution rates on outcomes. METHODS: Ovid Medline searches were conducted with limits "all adult" and published between "1973 to current" applied. National consensus statements were also reviewed. Eligibility was determined by two reviewers' assessment of title, abstract, and availability. RESULTS: A total of 85 eligible articles published between 1973 and 2016 were reviewed. The salient findings were (i) Crystalloids are favoured over colloids though evidence is lacking. The preferred crystalloid and hydration rates remain contentious. (ii) IV infusion of regular human insulin is preferred over the subcutaneous route or rapid acting insulin analogues. Administering an initial IV insulin bolus before low-dose insulin infusions obviates the need for supplemental insulin. Consensus-statements recommend fixed weight-based over "sliding scale" insulin infusions although evidence is weak. (iii) Potassium replacement is imperative although no trials compare replacement rates. (iv) Bicarbonate replacement offers no benefit in DKA with pH > 6.9. In severe metabolic acidosis with pH < 6.9, there is lack of both data and consensus regarding bicarbonate administration. (v) There is no evidence that phosphate replacement offers outcome benefits. Guidelines consider replacement appropriate in patients with cardiac dysfunction, anaemia, respiratory depression, or phosphate levels <0.32 mmol/L. (vi) Upon resolution of DKA, subcutaneous insulin is recommended with IV insulin infusions ceased with an overlap of 1-2 h. (vii) DKA resolution rates are often used as end points in studies, despite a lack of evidence that rapid resolution improves outcome. (viii) Implementation of DKA protocols lacks strong evidence for adherence but may lead to improved clinical outcomes. CONCLUSION: There are major deficiencies in evidence for optimal management of DKA. Current practice is guided by weak evidence and consensus opinion. All aspects of DKA management require RCTs to affirm or redirect management and formulate consensus evidence-based practice to improve patient outcomes
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