193 research outputs found

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

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    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

    Is it possible to predict which patients are most likely to benefit from intra-articular corticosteroid injections? A systematic review.

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    Aim: Intra-articular corticosteroid injections (IACIs) can reduce osteoarthritis-related pain, with differing levels of response across patient groups. This systematic review investigates what is known about the positive and negative predictors of outcomes in patients with osteoarthritis who undergo IACIs.Methods:We systematically searched the Medline, Embase and Cochrane databases to May 2023 for studies that evaluated patients undergoing IACIs for osteoarthritis and reported on predictors of outcomes in these patients.Results: Eight studies were included. Two were placebo-controlled trials, six were observational studies. Due to the heterogeneity of outcomes and variables between the studies, it was not possible to pool the results for formal meta-analysis. Higher baseline pain, older age, higher BMI, lower range of movement, higher Kellgren-Lawrence radiographic score, joint effusion and aspiration were shown to be predictors of a positive response to IACIs in some of the included studies. However, other studies showed no difference in response with these variables, or a negative correlation with response. Sex, smoking, mental health status, hypertension/ischaemic heart disease, diabetes mellitus, duration of symptoms, and socioeconomic status did not demonstrate any correlation with the prediction of positive or negative outcomes after IACIs.Conclusion: Several patient features have been identified as positive predictors of outcomes following IACIs. However, this systematic review has identified inconsistent and variable findings across the existing literature. Further research with standardisation of IACI administration and outcome measures is required to facilitate further analysis of the reliability and significance of predictive factors for response to IACIs

    Is 8:30 a.m. Still Too Early to Start School? A 10:00 a.m. School Start Time Improves Health and Performance of Students Aged 13-16.

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    While many studies have shown the benefits of later school starts, including better student attendance, higher test scores, and improved sleep duration, few have used starting times later than 9:00 a.m. Here we report on the implementation and impact of a 10 a.m. school start time for 13 to 16-year-old students. A 4-year observational study using a before-after-before (A-B-A) design was carried out in an English state-funded high school. School start times were changed from 8:50 a.m. in study year 0, to 10 a.m. in years 1-2, and then back to 8:50 a.m. in year 3. Measures of student health (absence due to illness) and academic performance (national examination results) were used for all students. Implementing a 10 a.m. start saw a decrease in student illness after 2 years of over 50% (p < 0.0005 and effect size: Cohen's d = 1.07), and reverting to an 8:50 a.m. start reversed this improvement, leading to an increase of 30% in student illness (p < 0.0005 and Cohen's d = 0.47). The 10:00 a.m. start was associated with a 12% increase in the value-added number of students making good academic progress (in standard national examinations) that was significant (<0.0005) and equivalent to 20% of the national benchmark. These results show that changing to a 10:00 a.m. high school start time can greatly reduce illness and improve academic performance. Implementing school start times later than 8:30 a.m., which may address the circadian delay in adolescents' sleep rhythms more effectively for evening chronotypes, appears to have few costs and substantial benefits

    The Vehicle, Spring 2002

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    Table of Contents Black Lace Under White OxfordAmee Bohrerpage 4 We Have ForgottenAubrey Bonannopage 4 The Grand Old Drink of the SouthNatalie Espositopage 5 SymphonyChristie Jean Hallpage 6 Sol from the CityJeremy Hartzellpage 7-10 Yellow TimeErika Larsonpage 10 Death of a Salesman\u27s WifeErika Larsonpage 11-12 This SideErika Larsonpage 12 JuiceTimothy Lockmanpage 13 Chess GameMike Scalespage 13 Facing HimTimothy Lockmanpage 14 ShameRon Lybargerpage 15 Sunlit HydrantMike Scalespage 15 11-22-63Reginald Mansfieldpage 16 four cornersDave Moutraypage 17 regretting PamDave Moutraypage 18-19 Chicago SummertimeLisa Sarmpage 19 Hands of TimeJessica Shekletonpage 20 An AppointmentJosh Sopiarzpage 21 Our Fates and Old Men\u27s GlassesJosh Sopiarzpage 22 An Apple Orchard PicnicJosh Sopiarzpage 23 November GraysJoe Webbpage 24 The AxJanet Windeguthpage 25-31 The Old Porch SwingJoe Webbpage 32 Green MachineQynn McCrory, H.S. Writing Contest Winnerpage 33 My Little PonyJ. Benjamin Blount, H.S. Writing Contest Winnerpage 34 Biographiespage 35-36https://thekeep.eiu.edu/vehicle/1077/thumbnail.jp

    Identifying the Best Times for Cognitive Functioning Using New Methods: Matching University Times to Undergraduate Chronotypes

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    University days generally start at fixed times in the morning, often early morning, without regard to optimal functioning times for students with different chronotypes. Research has shown that later starting times are crucial to high school students' sleep, health, and performance. Shifting the focus to university, this study used two new approaches to determine ranges of start times that optimize cognitive functioning for undergraduates. The first is a survey-based, empirical model (SM), and the second a neuroscience-based, theoretical model (NM). The SM focused on students' self-reported chronotype and times they feel at their best. Using this approach, data from 190 mostly first and second year university students were collected and analyzed to determine optimal times when cognitive performance can be expected to be at its peak. The NM synthesized research in sleep, circadian neuroscience, sleep deprivation's impact on cognition, and practical considerations to create a generalized solution to determine the best learning hours. Strikingly the SM and NM results align with each other and confirm other recent research in indicating later start times. They add several important points: (1) They extend our understanding by showing that much later starting times (after 11 a.m. or 12 noon) are optimal; (2) Every single start time disadvantages one or more chronotypes; and (3) The best practical model may involve three alternative starting times with one afternoon shared session. The implications are briefly considered

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

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    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
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