83 research outputs found
Interior Noise Predictions in the Preliminary Design of the Large Civil Tiltrotor (LCTR2)
A prediction scheme was established to compute sound pressure levels in the interior of a simplified cabin model of the second generation Large Civil Tiltrotor (LCTR2) during cruise conditions, while being excited by turbulent boundary layer flow over the fuselage, or by tiltrotor blade loading and thickness noise. Finite element models of the cabin structure, interior acoustic space, and acoustically absorbent (poro-elastic) materials in the fuselage were generated and combined into a coupled structural-acoustic model. Fluctuating power spectral densities were computed according to the Efimtsov turbulent boundary layer excitation model. Noise associated with the tiltrotor blades was predicted in the time domain as fluctuating surface pressures and converted to power spectral densities at the fuselage skin finite element nodes. A hybrid finite element (FE) approach was used to compute the low frequency acoustic cabin response over the frequency range 6-141 Hz with a 1 Hz bandwidth, and the Statistical Energy Analysis (SEA) approach was used to predict the interior noise for the 125-8000 Hz one-third octave bands
Influence of ocean freshening on shelf phytoplankton dynamics
Author Posting. © American Geophysical Union, 2007. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 34 (2007): L24607, doi:10.1029/2007GL032010.Climate change-induced freshening of the ocean can enhance vertical stratification and alter circulation patterns in ways that influence phytoplankton dynamics. We examined the timing of spring phytoplankton blooms and the magnitude of net primary productivity in the Nova Scotian Shelf (NSS) - Gulf of Maine (GoM) region with respect to seasonal and interannual changes in surface water freshening from 1998 to 2006. The general pattern of temporal westward progression of the phytoplankton bloom corresponds with the gradient of increasing sea surface salinity from the NSS in the east to the western GoM. Increased freshening enhances the spatial gradients in bloom timing by stimulating earlier blooms upstream (NSS), but it has less impact downstream (the western GoM). Strong spatial gradients (increasing westward) of mean chlorophyll concentration and net primary productivity during post-bloom months (MayâJune) indicate that lower sea surface salinity upstream can likely impede nutrient fluxes from deep water and therefore affect overall productivity.We thank NSF grant OCE-0727033 and
NOAA grant NA17RJ1223 to RJ, CSD and RCB, NSF grants OCE-
0606612 and OCE-0726577 to DWT, and NSF grants OCE-0606928 and
OCE-0726851 to CC
Experimental Feedback Control of Flow Induced Cavity Tones
Discrete-time, linear quadratic methods were used to design feedback controllers for reducing tones generated by flow over a cavity. The dynamics of a synthetic jet actuator mounted at the leading edge of the cavity as observed by two microphones in the cavity were modeled over a broad frequency range using state space models computed from experimental data. Variations in closed loop performance as a function of model order, control order, control bandwidth, and state estimator design were studied using a cavity in the Probe Calibration Tunnel at NASA Langley. The controller successfully reduced the levels of multiple cavity tones at the tested flow speeds of Mach 0.275, 0.35, and 0.45. In some cases, the closed loop results were limited by excitation of sidebands of the cavity tones, or the creation of new tones at frequencies away from the cavity tones. Nonetheless, the results validate the combination of optimal control and experimentally-generated state space models, and suggest this approach may be useful for other flow control problems. The models were not able to account for non-linear dynamics, such as interactions between tones at different frequencies
The Role of Endocarditis, Myocarditis and Pericarditis in Qualitative and Quantitative Data Analysis
The current study is the first scientometric analysis of research activity and output in the field of inflammatory disorders of the heart (endo-, myo- and pericarditis). Scientometric methods are used to compare scientific performance on national and on international scale to identify single areas of research interest. Interest and research productivity in inflammatory diseases of the heart have increased since 1990. The majority of publications about inflammatory heart disorders were published in Western Europe and North America. The United States of America had a leading position in terms of research productivity and quality; half of the most productive authors in this study came from American institutions. The analysis of international cooperation revealed research activity in countries that are less established in the field of inflammatory heart disorder research, such as Brazil, Saudi Arabia and Tunisia. These results indicate that future research of heart inflammation may no longer be influenced predominantly by a small number of countries. Furthermore, this study revealed weaknesses in currently established scientometric parameters (i.e., h-index, impact factor) that limit their suitability as measures of research quality. In this respect, self-citations should be generally excluded from calculations of h-index and impact factor
Description and evaluation of an EBM curriculum using a block rotation
BACKGROUND: While previous authors have emphasized the importance of integrating and reinforcing evidence-based medicine (EBM) skills in residency, there are few published examples of such curricula. We designed an EBM curriculum to train family practice interns in essential EBM skills for information mastery using clinical questions generated by the family practice inpatient service. We sought to evaluate the impact of this curriculum on interns, residents, and faculty. METHODS: Interns (n = 13) were asked to self-assess their level of confidence in basic EBM skills before and after their 2-week EBM rotation. Residents (n = 21) and faculty (n = 12) were asked to assess how often the answers provided by the EBM intern to the inpatient service changed medical care. In addition, residents were asked to report how often they used their EBM skills and how often EBM concepts and tools were used in teaching by senior residents and faculty. Faculty were asked if the EBM curriculum had increased their use of EBM in practice and in teaching. RESULTS: Interns significantly increased their confidence over the course of the rotation. Residents and faculty felt that the answers provided by the EBM intern provided useful information and led to changes in patient care. Faculty reported incorporating EBM into their teaching (92%) and practice (75%). Residents reported applying the EBM skills they learned to patient care (86%) and that these skills were reinforced in the teaching they received outside of the rotation (81%). All residents and 11 of 12 faculty felt that the EBM curriculum had improved patient care. CONCLUSIONS: To our knowledge, this is the first published EBM curriculum using an individual block rotation format. As such, it may provide an alternative model for teaching and incorporating EBM into a residency program
Multi-ancestry genome-wide association meta-analysis of Parkinson?s disease
Although over 90 independent risk variants have been identified for Parkinsonâs disease using genome-wide association studies, most studies have been performed in just one population at a time. Here we performed a large-scale multi-ancestry meta-analysis of Parkinsonâs disease with 49,049 cases, 18,785 proxy cases and 2,458,063 controls including individuals of European, East Asian, Latin American and African ancestry. In a meta-analysis, we identified 78 independent genome-wide significant loci, including 12 potentially novel loci (MTF2, PIK3CA, ADD1, SYBU, IRS2, USP8, PIGL, FASN, MYLK2, USP25, EP300 and PPP6R2) and fine-mapped 6 putative causal variants at 6 known PD loci. By combining our results with publicly available eQTL data, we identified 25 putative risk genes in these novel loci whose expression is associated with PD risk. This work lays the groundwork for future efforts aimed at identifying PD loci in non-European populations
From which point do we begin? : on combining the multiliteral and multiperspectival
This text below transcribes a hypothetical and âpataphysical dialogue by a group of interlocutors inquiring into the âwhat and howâ of multimodal, Content and Language Integrated Learning (CLIL) methodology. It builds on a unique research paradigm concerned with combining CLIL and multiliteracies theory in the Japanese tertiary education context (Bradley, 2015; Bradley & Cole, 2016; Bradley, Hunt, & Cole, 2017). Synthesizing research on CLIL methodology and multiliteracies theory, the paper simultaneously manifests and explores a dialogic âthinking modelâ for examining complex philosophical and ethical issues with students at beginning or intermediate English levels. Faced with the Japanese government demand to offer more content courses or content-based-instruction (CBI) solely in English, we explore the potential of a CLIL-inspired multiliteracies approach, analyzing numerous examples taken from actual classroom experiences that illustrate how such an approach can overcome the lack of critical thinking and critical media literacy among students. This paper contributes to research on CLIL (Coyle, 2008; Koike, 2016) by demonstrating the applicability of a thinking model for teachers working with low-to intermediate English. It is presented in a dialogic, âpataphysical format as a way to question the âpoint of viewâ of academic research and indeed to transform the practice of academic writing itself
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