806 research outputs found

    Window acoustic study for advanced turboprop aircraft

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    An acoustic analysis was performed to establish window designs for advanced turboprop powered aircraft. The window transmission loss requirements were based on A-weighted interior noise goals of 80 and 75 dBA. The analytical results showed that a triple pane window consisting of two glass outer panes and an inner pane of acrylic would provide the required transmission loss and meet the sidewall space limits. Two window test articles were fabricated for laboratory evaluation and verification of the predicted transmission loss. Procedures for performing laboratory tests are presented

    Sonic environment of aircraft structure immersed in a supersonic jet flow stream

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    Test methods for determining the sonic environment of aircraft structure that is immersed in the flow stream of a high velocity jet or that is subjected to the noise field surrounding the jet, were investigated. Sonic environment test data measured on a SCAT 15-F model in the flow field of Mach 1.5 and 2.5 jets were processed. Narrow band, lateral cross correlation and noise contour plots are presented. Data acquisition and reduction methods are depicted. A computer program for scaling the model data is given that accounts for model size, jet velocity, transducer size, and jet density. Comparisons of scaled model data and full size aircraft data are made for the L-1011, S-3A, and a V/STOL lower surface blowing concept. Sonic environment predictions are made for an engine-over-the-wing SST configuration

    Development and testing of cabin sidewall acoustic resonators for the reduction of cabin tone levels in propfan-powered aircraft

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    The use of Helmholtz resonators to increase the sidewall transmission loss (TL) in aircraft cabin sidewalls is evaluated. Development, construction, and test of an aircraft cabin acoustic enclosure, built in support of the Propfan Test Assessment (PTA) program, is described. Laboratory and flight test results are discussed. Resonators (448) were located between the enclosure trim panels and the fuselage shell. In addition, 152 resonators were placed between the enclosure and aircraft floors. The 600 resonators were each tuned to a propfan fundamental blade passage frequency (235 Hz). After flight testing on the PTA aircraft, noise reduction (NR) tests were performed with the enclosure in the Kelly Johnson Research and Development Center Acoustics Laboratory. Broadband and tonal excitations were used in the laboratory. Tonal excitation simulated the propfan flight test excitation. The resonators increase the NR of the cabin walls around the resonance frequency of the resonator array. Increases in NR of up to 11 dB were measured. The effects of flanking, sidewall absorption, cabin absorption, resonator loading of trim panels, and panel vibrations are presented. Resonator and sidewall panel design and test are discussed

    Analytical study of interior noise control by fuselage design techniques on high-speed, propeller-driven aircraft

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    The acoustical treatment mass penalties required to achieve an interior noise level of 80 dBA for high speed, fuel efficient propfan-powered aircraft are determined. The prediction method used is based on theory developed for the outer shell dynamics, and a modified approach for add-on noise control element performance. The present synthesis of these methods is supported by experimental data. Three different sized aircraft are studied, including a widebody, a narrowbody and a business sized aircraft. Noise control penalties are calculated for each aircraft for two kinds of noise control designs: add-on designs, where the outer wall structure cannot be changed, and advanced designs where the outer wall stiffness level and the materials usage can be altered. For the add-on designs, the mass penalties range from 1.7 to 2.4 percent of the takeoff gross weight (TOGW) of the various aircraft, similar to preliminary estimates. Results for advanced designs show significant reductions of the mass penalties. For the advanced aluminum designs the penalties are 1.5% of TOGW, and for an all composite aircraft the penalties range from 0.74 to 1.4% of TOGW

    Transport composite fuselage technology: Impact dynamics and acoustic transmission

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    A program was performed to develop and demonstrate the impact dynamics and acoustic transmission technology for a composite fuselage which meets the design requirements of a 1990 large transport aircraft without substantial weight and cost penalties. The program developed the analytical methodology for the prediction of acoustic transmission behavior of advanced composite stiffened shell structures. The methodology predicted that the interior noise level in a composite fuselage due to turbulent boundary layer will be less than in a comparable aluminum fuselage. The verification of these analyses will be performed by NASA Langley Research Center using a composite fuselage shell fabricated by filament winding. The program also developed analytical methodology for the prediction of the impact dynamics behavior of lower fuselage structure constructed with composite materials. Development tests were performed to demonstrate that the composite structure designed to the same operating load requirement can have at least the same energy absorption capability as aluminum structure

    Mostra de cores: uma abordagem contextualizada

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    Anais do II Seminário Seminário Estadual PIBID do Paraná: tecendo saberes / organizado por Dulcyene Maria Ribeiro e Catarina Costa Fernandes — Foz do Iguaçu: Unioeste; Unila, 2014Este trabalho apresenta uma Mostra de Cores realizada no Colégio Estadual Presidente Castelo Branco da cidade de Toledo/PR. A Mostra foi apresentada a 5 (cinco) turmas no Ensino Médio regular e de Formação Docente. Com o objetivo de divulgar o projeto PIBID no colégio, de maneira diferenciada e dinâmica, discutir sobre a Química das Cores. A mostra foi divida em 2 partes: a parte histórica e experimental sobre as cores. Utilizamos um questionário investigativo sobre o tema trabalhado e apresentamos aqui os resultados obtidos com as respostas de 2 (duas) turmas do curso de Formação Docente, composta por 61 estudantes, na qual a maioria consegue relacionar as cores com a personalidade e ainda que, o destaque maior foi atribuído à influência das cores influenciam no tamanho de um objeto e os estudos envolvendo as core

    Efficacy and Safety of Taspoglutide Versus Sitagliptin for Type 2 Diabetes Mellitus (T-Emerge 4 Trial)

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    INTRODUCTION: The efficacy and safety of taspoglutide, a long-acting human glucagon-like peptide-1 analog, were compared with sitagliptin or placebo, as adjunct to metformin, in patients with inadequately controlled type 2 diabetes. METHODS: In this randomized, double-blind, double-dummy, parallel-group trial, patients were randomized to taspoglutide 10 mg once weekly (QW), 20 mg QW, 100 mg sitagliptin once daily (QD), or placebo for 24 weeks, followed by 28-week short-term and 104-week long-term extension periods. The primary endpoint was change in glycosylated hemoglobin (HbA(1c)) after 24 weeks. RESULTS: In this study, 666 patients (baseline HbA(1c), 7.96% [SD, 0.87]; fasting plasma glucose, 9.61 mmol/L [2.56]; body weight, 92.4 kg [19.3]) were randomized to taspoglutide 10 mg QW (n = 190), 20 mg QW (n = 198), 100 mg sitagliptin QD (n = 185), or placebo (n = 93) for 24 weeks. After 24 weeks, least squares mean (SE) HbA(1c) reductions were greater with taspoglutide 10 mg (−1.23% [0.06]) and 20 mg (−1.30% [0.06]) versus sitagliptin (−0.89% [0.06]) or placebo (−0.10% [0.08]). Mean treatment differences with taspoglutide 10 mg and 20 mg were −0.34 (95% confidence intervals [CI]: −0.49, −0.19) and −0.41 (−0.56, −0.26) versus sitagliptin; and −1.13 (−1.31, −0.95) and −1.20 (−1.38, −1.02) versus placebo. Weight loss was greater with taspoglutide 10 mg (−1.8 kg [0.3]) and 20 mg (−2.6 kg [0.3]) than sitagliptin (−0.9 kg [0.3]) or placebo (−0.5 kg [0.4]). Effects on HbA(1c) and weight loss continued through 52 weeks of treatment. No cases of severe hypoglycemia occurred with any active treatment. Gastrointestinal adverse events, and allergic and injection-site reactions were higher in the taspoglutide groups, causing higher discontinuation rates. Anti-taspoglutide antibodies were confirmed in 46% of patients. CONCLUSION: Taspoglutide demonstrated better efficacy on glycemic control and weight loss than sitagliptin, but a high incidence of adverse events led to high discontinuation rates. The safety profile of taspoglutide in this trial was similar to other trials in the clinical program, and led to the discontinuation of dosing

    Local Knowledge and Social Sensors: Integrated Models of Text Analysis for Disaster Response

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    The present doctoral research investigates the role of local knowledge in supporting disaster response, by applying cognitive, predictive and ontological models to the study of text message exchange in relevant Social Networks. The lack of studies on local knowledge in risk domains, along with the growing attention of scholars and decision makers to open governance processes, underpin the three main research questions that have been addressed. As for the relevance of local knowledge to disaster response, human communication – in real or simulated emergency situations – seems to be imbued with culturally mediated understandings of spatiality, relationality and actions. Innovative spatial data science tools are therefore needed for tacit and vernacular knowledge to be adequately modelled and operationalized. With respect to the use of text messages in disaster response, it appears that distributed systems (which combine crowdsourcing methods with collaborative hypertext editors) may effectively complement volunteered or public participation GIS – to harness the potential of all-purpose social networks to reach out to the wider internet community. Finally, to foster the interpretation of text messages, three separate taxonomies (regarding Spatial Location, Needs and Actors) – each being linked to a terminal entity in DOLCE foundational ontology –, helped develop a shared conceptualization of risk. Future developments of the present work could concern the further integration between machine learning and ontological models, and advancing text classification methods

    Addition of or switch to insulin therapy in people treated with glucagon-like peptide-1 receptor agonists : a real-world study in 66 583 patients

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    Background Real world outcomes of addition or switch to insulin therapy in type 2 diabetes (T2DM) patients on glucagon-like paptide-1 receptor agonist (GLP-1RA) with inadequately controlled hyperglycaemia, are not known. Materials and methods Patients with T2DM (n = 66 583) with a minimum of 6 months of GLP-1RA treatment and without previous insulin treatment were selected. Those who added insulin (n = 39 599) or switched to insulin after GLP-1RA cessation (n = 4706) were identified. Adjusted changes in glycated haemoglobin (HbA1c), weight, systolic blood pressure (SBP), and LDL cholesterol were estimated over 24 months follow-up. Results Among those who continued with GLP-1RA treatment without adding or switching to insulin, the highest adjusted mean HbA1c change was achieved within 6 months, with no further glycaemic benefits observed during 24 months of follow-up. Addition of insulin within 6 months of GLP-1RA initiation was associated with 18% higher odds of achieving HbA1c <7% at 24 months, compared with adding insulin later. At 24 months, those who added insulin reduced HbA1c significantly by 0.55%, while no glycaemic benefit was observed in those who switched to insulin. Irrespective of intensification with insulin, weight, SBP and LDL cholesterol were significantly reduced by 3 kg, 3 mm Hg, and 0.2 mmol/L, respectively, over 24 months. Conclusions Significant delay in intensification of treatment by addition of insulin is observed in patients with T2DM inadequately controlled with GLP-1RA. Earlier addition of insulin is associated with better glycaemic control, while switching to insulin is not clinically beneficial during 2 years of treatment. Non-responding patients on GLP-1RA would benefit from adding insulin therapy, rather than switching to insulin
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