Reverse Thrust Aerodynamics of Variable Pitch Fans

Abstract Variable pitch fans are of interest for future low-pressure ratio fan systems since they provide improved operability relative to fixed pitch fans. If they can also be re-pitched such that they generate sufficient reverse thrust they could eliminate the engine drag and weight penalty associated with bypass duct thrust reversers. This paper sets out to understand the details of the 3D fan stage flow field in reverse thrust operation. This study uses the Advanced Ducted Propulsor variable pitch fan test case, which has a design fan pressure ratio of 1.29. Comparison with spanwise probe measurements show that the computational approach is valid for examining the variation of loss and work in the rotor in forward thrust. The method is then extended to a reverse thrust configuration using an extended domain and appropriate boundary conditions. Computations, run at two rotor stagger settings, show that the spanwise variation in relative flow angle onto the rotor aligns poorly to the rotor inlet metal angle. This leads to two dominant rotor loss sources: one at the tip associated with positive incidence and the second caused by negative incidence at lower span fractions. The second loss is reduced by opening the rotor stagger setting, and the first increases with rotor suction surface Mach number. The higher mass flow at more open rotor settings provide higher gross thrust, up to 49% of the forward take-off value, but is limited by the increased loss at high speed.Rolls-Royce pl

The power of the Monstrous: An introduction to the special issue

Alterity and Otherness have often been the privileged field of contemplation within Western philosophy. Since the Presocratic philosophers, Being has been defined in relation to – and more often opposed to – non-Being, just as Goodness has been considered in relation to Evil, Beauty in relation to the Ugly, Society in relation to Nature, and the examples could be multiplied ad libitum. Every identity is shaped in opposition to an excluded other, an outside, or some thing. Identity and alterity are thus constructed as two inseparable sides of a single, coherent philosophical discourse, or rather a field of various discourses that comprise a philosophy, associated with - although not limited to - the early centuries of what we call modernity

Modelling the Progression of Male Swimmers’ Performances through Adolescence

Insufficient data on adolescent athletes is contributing to the challenges facing youth athletic development and accurate talent identification. The purpose of this study was to model the progression of male sub-elite swimmers’ performances during adolescence. The performances of 446 males (12–19 year olds) competing in seven individual events (50, 100, 200 m freestyle, 100 m backstroke, breaststroke, butterfly, 200 m individual medley) over an eight-year period at an annual international schools swimming championship, run under FINA regulations were collected. Quadratic functions for each event were determined using mixed linear models. Thresholds of peak performance were achieved between the ages of 18.5 ± 0.1 (50 m freestyle and 200 m individual medley) and 19.8 ± 0.1 (100 m butterfly) years. The slowest rate of improvement was observed in the 200 m individual medley (20.7%) and the highest in the 100 m butterfly (26.2%). Butterfly does however appear to be one of the last strokes in which males specialise. The models may be useful as talent identification tools, as they predict the age at which an average sub-elite swimmer could potentially peak. The expected rate of improvement could serve as a tool in which to monitor and evaluate benchmarks

Programas Parentales Para la Prevención del Castigo Corporal: Una Revisión Sistemática

Estudios demuestran que el castigo corporal contra los niños es una práctica común y causa daños a su desarrollo. Dado que los principales perpetradores de las agresiones son padres/madres, es necesario promover programas parentales para guiarlos a criar a sus hijos sin violencia. Este estudio condujo una revisión sistemática de evaluaciones de programas parentales con contenido específico sobre la práctica de los castigos corporales. Se identificaron los procedimientos de intervención utilizados, diseños, resultados y limitaciones. Se utilizó el protocolo PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) para informar de los resultados. El estudio de la literatura fue conducido en bases de datos brasileñas y e internacionales entre 1994-2014, con sólo cuatro ensayos clínicos aleatorios (ECA). Todos los estudios informaron resultados satisfactorios en la disminución de la agresión de los padres contra sus hijos. La promoción de estudios con el debido rigor metodológico en el área se hace necesaria.Estudos evidenciam que o castigo corporal contra crianças é uma prática familiar frequente e causa prejuízos ao desenvolvimento infantil. Dado que os principais autores das agressões são pais/mães, torna-se necessário o desenvolvimento de programas parentais para orientá-los a educar os filhos sem violência. O presente estudo realizou uma revisão sistemática sobre avaliações de programas parentais com conteúdo específico para redução da prática do castigo corporal. Foram identificados procedimentos de intervenção, delineamentos, resultados e limitações. Utilizou-se o protocolo PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) para relatar os resultados A revisão compreendeu bases de dados nacionais e internacionais no período de 1994-2014. Um estudo brasileiro e oito internacionais foram selecionados como relevantes, sendo que apenas quatro utilizaram ensaio clínico randomizado (RCT). Todos os estudos relataram resultado satisfatório na diminuição das agressões dos pais aos filhos. Salienta-se a necessidade da promoção de estudos na área com o devido rigor metodológico.Studies have shown that corporal punishment against children is a common family practice, causing damage to child development. Considering that parents are the main perpetrators of this type of aggression, parenting programs are needed to raise children without violence. This study aimed at performing a systematic review of parenting programs evaluations to reduce corporal punishment. Intervention procedures, as well as design, results and limitations were identified for each study. The PRISMA protocol (Preferred Reporting Items for Systematic reviews and Meta-Analyses) was used for reporting the results. A literature survey was conducted in Brazilian databases, as well as English ones from 1994-2014. One Brazilian study and eight international studies were selected as relevant, and only four used randomized controlled trials (RCT). All studies reported satisfactory results in decreasing aggression by parents against their children. Further research in the area with solid methodology is recommended

Prediction of peak oxygen uptake using the modified shuttle test — Methodological concerns and implications for clinical practice

This is the author accepted manuscrip

Exercise-induced fatigue in young people: advances and future perspectives

This is the author accepted manuscript. The final version is available from Springer Verlag via the DOI in this record.PURPOSE: In recent decades, the interest for exercise-induced fatigue in youth has substantially increased, and the effects of growth on the peripheral (muscular) and central (neural) mechanisms underpinning differences in neuromuscular fatigue between healthy children and adults have been described more extensively. The purpose of this review is to retrieve, report, and analyse the findings of studies comparing neuromuscular fatigue between children and adults. Objective measures of the evaluation of the physiological mechanisms are discussed. METHOD: Major databases (PubMed, Ovid, Scopus and Web of Science) were systematically searched and limited to English language from inception to September 2017. RESULT: Collectively, the analyzed studies indicate that children experience less muscular and potentially more neural fatigue than adults. However, there are still many unknown aspects of fatigue regarding neural (supraspinal and spinal) and peripheral mechanisms that should be more thoroughly examined in children. CONCLUSION: Suitable methods, such as transcranial magnetic stimulation, transcranial electrical stimulation, functional magnetic resonance imaging, near-infrared spectroscopy, tendon vibration, H-reflex, and ultrasound are recommended in the research field of fatigue in youth. By designing studies that test the fatigue effects in movements that replicate daily activities, new knowledge will be acquired. The linkage and interaction between physiological, cognitive, and psychological aspects of human performance remain to be resolved in young people. This can only be successful if research is based on a foundation of basic research focused on the mechanisms of fatigue while measuring all three above aspects

Recognition-Controlled Membrane Translocation for Signal Transduction across Lipid Bilayers

Membrane signaling proteins transduce information across lipid bilayer membranes in response to extra-cellular binding of chemical messengers. The design of chemical systems that initiate transmembrane signal transduction through molecular binding events is a critical step toward preparing responsive synthetic vesicles. Here we report a vesicle-based signaling system controlled by a metal cation binding event. Competition between binding of copper ions to a membrane-embedded synthetic transducer and to an extra-vesicle messenger (EDTA) is used to control translocation of the transducer across the lipid bilayer. The translocation process is coupled to activation of a catalyst that turns over encapsulated substrates on the inside of the vesicle to generate an amplified fluorescence output signal. External EDTA and copper ions can be used to reversibly switch catalysis inside the vesicles on and off in a controlled manner

Using social media to detect and locate wildfires

This is the final version of the article. Available from AAAI via the URL in this record.Methods for detecting and tracking natural hazards continue to increase in coverage, resolution and reliability. However, information on the social impacts of natural hazards is often lacking. Here we test the feasibility of using social media data (Twitter and Instagram) to detect and map an important class of natural hazard: wildfires. We analyse social media posts associated with wildfires over several time periods and compare them with wildfire occurrence data derived from satellite-based remote sensing data and on-the-ground observations. For the whole of the contiguous United States, we find significant temporal correlations between wildfire-related social media activity and wildfire occurrence, but also that there is substantial variation in the strength of this relationship at smaller spatial scales (states and counties). We then explore the utility of social media for location of wildfire events, finding good evidence to support further development of such methods. We conclude by discussing several challenges and opportunities for application of this novel data resource to provide information on impacts of natural hazards.The authors were supported by a Research on Changes of Variability and Environmental Risk (RECoVER) grant funded by EPSRC (EP/M008495/1)

Cardiac autonomic function, cardiovascular risk and physical activity in adolescents.

This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.The aims of this study were to investigate in adolescents: 1) the relationships of physical activity (PA) and cardiorespiratory fitness (CRF) to traditional CVD risk factors, rest and recovery autonomic function; and 2) whether autonomic function strengthens the associations between PA, CRF and CVD risk. Fifty-four (22 girls) adolescents had traditional CVD risk factors, rest and recovery autonomic function evaluated. CRF was measured using a steep ramp cycle test and PA was assessed with accelerometers. Resting HRV (and RMSSD30) and heart rate recovery (T30, HHRτ) were used. Clustered traditional (CVDRtrad) and autonomic (CVDRauto) risk scores were created and added to form a composite clustered CVD risk score (CVDRcom). PA and CRF were significantly and negatively associated with traditional CVD risk factors. Moderate (MPA) and vigorous (VPA) were positively related to resting RMSSD, and negatively related to T30 and HHRτ (all P<0.05). RMSSD30 recovered faster in the high compared to low median split for VPA. Stronger associations for CVDRcom compared to CVDRtrad were observed for MPA (CVDRcom: r2=0.32, P=<0.001; CVDRtrad: r2=0.17, P=0.002), and VPA (CVDRcom: r2=0.18, P=0.001; CVDRtrad: r2=0.06, P=0.08). These findings strengthen the proposed additional beneficial effects of PA on autonomic function above traditional CVD risk factors.RSO is funded by Science Without Borders, CAPES, Brazil, under the process number:10423-13-3

Pulse-Administered Toceranib Phosphate Plus Lomustine for Treatment of Unresectable Mast Cell Tumors in Dogs.

BackgroundNonresectable mast cell tumors (MCT) in dogs remain a therapeutic challenge, and investigation of novel combination therapies is warranted. Intermittent administration of tyrosine kinase inhibitors (TKI) combined with cytotoxic chemotherapy may effectively chemosensitize canine MCT while decreasing cost and adverse effects associated with either agent administered as monotherapy.Hypothesis/objectivesThe primary study objectives were to (1) identify the maximally tolerated dose (MTD), (2) determine the objective response rate (ORR) and (3) describe the adverse event profile of pulse-administered toceranib phosphate (TOC) combined with lomustine.AnimalsForty-seven client-owned dogs with measurable MCT.MethodsToceranib phosphate was given PO on days 1, 3 and 5 of a 21-day cycle at a target dosage of 2.75 mg/kg. Lomustine was given PO on day 3 of each cycle at a starting dosage of 50 mg/m(2) . All dogs were concurrently treated with diphenhydramine, omeprazole, and prednisone.ResultsThe MTD of lomustine was established at 50 mg/m(2) when combined with pulse-administered TOC; the dose-limiting toxicity was neutropenia. Forty-one dogs treated at the MTD were evaluable for outcome assessment. The ORR was 46% (4 complete response, 15 partial response) and the overall median progression-free survival (PFS) was 53 days (1 to &gt;752 days). On multivariate analysis, variables significantly associated with improved PFS included response to treatment, absence of metastasis, and no previous chemotherapy.Conclusions and clinical importanceCombined treatment with pulse-administered TOC and lomustine generally is well tolerated and may be a reasonable treatment option for dogs with unresectable or metastatic MCT