Advanced Low NO Sub X Combustors for Supersonic High-Altitude Aircraft Gas Turbines

A test rig program was conducted with the objective of evaluating and minimizing the exhaust emissions, in particular NO sub x, of three advanced aircraft combustor concepts at a simulated, high altitude cruise condition. The three combustor designs, all members of the lean reaction, premixed family, are the Jet Induced Circulation (JIC) combustor, the Vortex Air Blast (VAB) combustor, and a catalytic combustor. They were rig tested in the form of reverse flow can combustors in the 0.127 m. (5.0 in.) size range. Various configuration modifications were applied to each of the initial JIC and VAB combustor model designs in an effort to reduce the emissions levels. The VAB combustor demonstrated a NO sub x level of 1.1 gm NO2/kg fuel with essentially 100% combustion efficiency at the simulated cruise combustor condition of 50.7 N/sq cm (5 atm), 833 K (1500 R) inlet pressure and temperature respectively and 1778 K (3200 R) outlet temperature on Jet-A1 fuel. Early tests on the catalytic combustor were unsuccessful due to a catalyst deposition problem and were discontinued in favor of the JIC and VAB tests. In addition emissions data were obtained on the JIC and VAB combustors at low combustor inlet pressure and temperatures that indicate the potential performance at engine off-design conditions

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

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

Abstract 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

302. FIBROID ASSOCIATED HEAVY MENSTRUAL BLEEDING: CORRELATION OF CLINICAL SYMPTOMS, DOPPLER ULTRASOUND ASSESSMENT OF VASCULATURE AND TISSUE GENE EXPRESSION PROFILES

Understanding of the mechanisms that cause fibroid associated heavy menstrual bleeding (HMB) is limited. Despite many fibroids having a highly vascular peri-fibroid myometrial (PFM) zone, angiogenic gene expression in this area has never been investigated. The aim of this study was to correlate clinical symptoms, ultrasound appearances and tissue gene expression profiles in women scheduled for hysterectomy due to symptomatic fibroids. We hypothesised that fibroid heterogeneity, colour flow and spectral Doppler resistive indices would correlate with differences in gene expression profiles. It was thought and that increased peri-fibroid gene expression of key angiogenic genes would correlate with increased peri-fibroid vascularity. N = 6 patients underwent B-mode, colour and spectral Doppler ultrasound assessment. Following hysterectomy tissue samples collected from three areas – fibroid, PFM and distant myometrium (DM) were analysed using quantitative RT-PCR and a customised angiogenesis PCR array. A higher mean peak systolic velocity (PSV) in the PFM region when compared to mean PSV within the fibroid (P &lt; 0.001) was seen. Differences in angiogenic gene expression were consistent with the heterogeneity of the clinical data collected. One fibroid sample showed dissimilar gene expression to all other fibroids; at ultrasound and sample collection significant degenerative features were observed. Fibroid heterogeneity within a single uterus was also demonstrated, with two fibroids from the one uterus having significantly dissimilar gene profiles and ultrasound appearances. No differences in gene expression were found between PFM and DM. Despite this, gene interaction maps showed different interaction of genes between fibroid and PFM regions compared to genes between the fibroid and the DM. These are the first molecular data demonstrating that the PFM region may be functionally distinct from distant myometrium. </jats:p

Advanced Low NOx Combustors for Supersonic High-Altitude Aircraft Gas Turbines

In recent years, the role of oxides of nitrogen (NOX) within the overall production mechanism of photochemical smog has been recognized, if not completely understood, and in consequence, these oxides are currently considered as serious, immediate, environmental pollutants.</jats:p