Forward velocity effects on fan noise and the influence of inlet aeroacoustic design as measured in the NASA Ames 40 x 80 foot wind tunnel

The inlet radiated noise of a turbofan engine was studied. The principal research objectives were to characterize or suppress such noise with particular regard to its tonal characteristics. The major portion of this research was conducted by using ground-based static testing without simulation of aircraft forward speed or aircraft installation-related aeroacoustic effects

Sensitivity of terrestrial precipitation trends to the structural evolution of sea surface temperatures

Pronounced intermodel differences in the projected response of land surface precipitation (LSP) to future anthropogenic forcing remain in the Coupled Model Intercomparison Project Phase 5 model integrations. A large fraction of the intermodel spread in projected LSP trends is demonstrated here to be associated with systematic differences in simulated sea surface temperature (SST) trends, especially the representation of changes in (i) the interhemispheric SST gradient and (ii) the tropical Pacific SSTs. By contrast, intermodel differences in global mean SST, representative of differing global climate sensitivities, exert limited systematic influence on LSP patterns. These results highlight the importance to regional terrestrial precipitation changes of properly simulating the spatial distribution of large-scale, remote changes as reflected in the SST response to increasing greenhouse gases. Moreover, they provide guidance regarding which region-specific precipitation projections may be potentially better constrained for use in climate change impact assessments

Extending the Strategy Based Risk Model Using the Delphi Method: An Application to the Validation Process for Research and Developmental (R&D) Satellites

The validation between a research and developmental satellite and its ground system is critical to ensuring the success on-orbit. However, the exact process for completing validation is not documented, frequently underfunded, and accomplished ad hoc. This leads to debate regarding maintenance of budget and schedule, while ensuring on-orbit success. This thesis examines readiness and on-orbit activities within the U.S. Air Force Space Development and Test Wing\u27s Research Development Test and Evaluation Support Complex. Combining historical data with the consultation of subject matter experts, a validation process was defined. Risks associated with this process were then analyzed using the Strategy Based Risk Model, and were evaluated based on the probability of occurrence and severity of impact. The validation process and associated costs were validated using the Delphi Method. Next, we transformed the results into a simulation that generates distributions of possible costs and risk outcomes. Finally we applied the simulation to a program, and distributed it to program managers for feedback. The simulation will be distributed to program offices to support tailoring a validation plan relative to their budget. The simulation will give decision makers greater fidelity into the expected risks and costs associated with the selected validation process

The impact of ENSO on Southern African rainfall in CMIP5 ocean atmosphere coupled climate models

We study the ability of 24 ocean atmosphere global coupled models from the Coupled Model Intercomparison Project 5 (CMIP5) to reproduce the teleconnections between El Niño Southern Oscillation (ENSO) and Southern African rainfall in austral summer using historical forced simulations, with a focus on the atmospheric dynamic associated with El Niño. Overestimations of summer rainfall occur over Southern Africa in all CMIP5 models. Abnormal westward extensions of ENSO patterns are a common feature of all CMIP5 models, while the warming of the Indian Ocean that happens during El Niño is not correctly reproduced. This could impact the teleconnection between ENSO and Southern African rainfall which is represented with mixed success in CMIP5 models. Large-scale anomalies of suppressed deep-convection over the tropical maritime continent and enhanced convection from the central to eastern Pacific are correctly simulated. However, regional biases occur above Africa and the Indian Ocean, particularly in the position of the deep convection anomalies associated with El Niño, which can lead to the wrong sign in rainfall anomalies in the northwest part of South Africa. From the near-surface to mid-troposphere, CMIP5 models underestimate the observed anomalous pattern of pressure occurring over Southern Africa that leads to dry conditions during El Niño years

Impaired vocal cord mobility in the setting of acute suppurative thyroiditis

Background Acute suppurative thyroiditis is an increasingly rare entity, accounting for less than 0.1% of thyroid surgery. This is the first report in the literature of acute thyroiditis causing a unilateral reversible vocal cord paralysis. Methods A 41-year old woman was initially seen with a unilateral vocal cord paralysis resulting from acute suppurative thyroiditis. Results The vocal cord paralysis resolved following surgical drainage of the thyroid abscess and treatment with intravenous antibiotics. Conclusions We present this case to emphasize the need for a complete and thorough head and neck exam including preoperative documentation of vocal cord mobility. © 1997 John Wiley & Sons, Inc. Head Neck 19: 235–237, 1997.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/35112/1/13_ftp.pd

On the Reliability of Meta-Analytic Reviews

The article addresses the issue of intercoder reliability in meta-analyses. The current practice of reporting a single, mean intercoder agreement score in meta-analytic research leads to systematic bias and overestimates the true reliability. An alternative approach is recommended in which average intercoder agreement scores or other reliability statistics are calculated within clusters of coded variables. These clusters form a hierarchy in which the correctness of coding decisions at a given level of the hierarchy is contingent on decisions made at higher levels. Two separate studies of intercoder agreement in meta-analysis are presented to assess the validity of the model.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67840/2/10.1177_0193841X9301700303.pd