A Hall effect thruster plume model including large-angle elastic scattering

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76556/1/AIAA-2001-3355-806.pd

Impact of Heavy Aircraft Operations on Airport Capacity at Newark Liberty International Airport

Aviation System Performance Metrics (ASPM) departure and arrival rate data is collected for four common airport confi gurations at Newark Liberty International Airport (EWR) under Visual Meteorological Conditions (VMC) for the period 2007-2008. The effect of the number of Heavy (including Boeing 757) operations on overall airport throughput is then investigated. The investigation shows that Heavy departures and arrivals negatively impact overall airport capacity. Mechanisms by which controllers mitigate the e ffects of Heavy arrivals and departures are also identifi ed. A preliminary quanti fication of the impact of operations of Heavy aircraft is performed with a parametric estimation of the capacity of the airport. The findings of this empirical study highlight that Heavy aircraft departures introduce a very small effi ciency loss in terms of airport departure capacity. By contrast, under some runway con figurations, Heavy aircraft arrivals have a more detrimental e ffect on airport departure capacity

Between-airport heterogeneity in air toxics emissions associated with individual cancer risk thresholds and population risks

Abstract Background Airports represent a complex source type of increasing importance contributing to air toxics risks. Comprehensive atmospheric dispersion models are beyond the scope of many applications, so it would be valuable to rapidly but accurately characterize the risk-relevant exposure implications of emissions at an airport. Methods In this study, we apply a high resolution atmospheric dispersion model (AERMOD) to 32 airports across the United States, focusing on benzene, 1,3-butadiene, and benzo [a]pyrene. We estimate the emission rates required at these airports to exceed a 10-6 lifetime cancer risk for the maximally exposed individual (emission thresholds) and estimate the total population risk at these emission rates. Results The emission thresholds vary by two orders of magnitude across airports, with variability predicted by proximity of populations to the airport and mixing height (R2 = 0.74–0.75 across pollutants). At these emission thresholds, the population risk within 50 km of the airport varies by two orders of magnitude across airports, driven by substantial heterogeneity in total population exposure per unit emissions that is related to population density and uncorrelated with emission thresholds. Conclusion Our findings indicate that site characteristics can be used to accurately predict maximum individual risk and total population risk at a given level of emissions, but that optimizing on one endpoint will be non-optimal for the other.</p

Simultaneous Measurement of Normal and Friction Forces Using a Cantilever-Based Optical Interfacial Force Microscope

We measured normal and friction forces simultaneously using a recently developed cantilever-based optical interfacial force microscope (COIFM) technique for studies of interfacial structures and mechanical properties of nanoscale materials. We derived how the forces can be incorporated into the detection signal using the classical Euler equation for beams. A lateral modulation with the amplitude of one nanometers was applied to create the friction forces between tip and sample. We demonstrated its capability by measuring normal and friction forces of interfacial water at the molecular scale over all distance ranges

Assessing institutional relations in development partnerships: the Land Development Corporation and the Hong Kong Government prior to 1997

This paper interprets and develops contemporary notions of partnership in relation to Hong Kong's Land Development Corporation. It demonstrates how such agencies are likely to become overdependent on their private-sector partners or ineffective in policy delivery, unless endowed with adequate powers and resources. In this context, it suggests that the LDC's capacity to promote urban renewal was undermined particularly by the institutional requirement to assemble redevelopment sites in multiple ownership principally through negotiation. While seeking to explain this weakness in relation to the socio-cultural context of Hong Kong, it warns that, in applying the Western experience of partnership elsewhere, full account must be taken of local circumstances and constraints

Integrating Commercial Healthcare Datasets for Aeromedical Risk Analyses

693KA8-22-C-00001The Federal Aviation Administration (FAA) Office of Aerospace Medicine requires comprehensive longitudinal healthcare datasets to augment internal data for the purpose of conducting safety risk assessments to update medical standards (i.e. data dirven, risk based decision making). The Federal Aviation Administration (FAA) tasked The MITRE Corporation\u2019s Center for Advanced Aviation System Development (MITRE CAASD), in its Innovation Partner role, to identify commercial healthcare datasets that hold potential value in forecasting medical risk and are suitable for integration into the Aeromedical Data Environment. MITRE CAASD performed a market survey of existing healthcare datasets available commercially or for public use. This market survey led to the identification of over 40 healthcare data sources, many of which contain numerous subordinate sets. An initial set of screening criteria ensured that candidate data sources were sufficiently suitable for modeling objectives; this screening reduced the set to three final candidate data sources. These three data sources were compared using a set of features relevant to risk modeling of aeromedically relevant outcomes by condition. This set of comparison features included their coverage of medical conditions of interest to the FAA, as well as factors impacting integration into the aeromedical data environment

The environmental security debate and its significance for climate change

Policymakers, military strategists and academics all increasingly hail climate change as a security issue. This article revisits the (comparatively) long-standing “environmental security debate” and asks what lessons that earlier debate holds for the push towards making climate change a security issue. Two important claims are made. First, the emerging climate security debate is in many ways a re-run of the earlier dispute. It features many of the same proponents and many of the same disagreements. These disagreements concern, amongst other things, the nature of the threat, the referent object of security and the appropriate policy responses. Second, given its many different interpretations, from an environmentalist perspective, securitisation of the climate is not necessarily a positive development

Ambient-aware continuous care through semantic context dissemination

Background: The ultimate ambient-intelligent care room contains numerous sensors and devices to monitor the patient, sense and adjust the environment and support the staff. This sensor-based approach results in a large amount of data, which can be processed by current and future applications, e. g., task management and alerting systems. Today, nurses are responsible for coordinating all these applications and supplied information, which reduces the added value and slows down the adoption rate. The aim of the presented research is the design of a pervasive and scalable framework that is able to optimize continuous care processes by intelligently reasoning on the large amount of heterogeneous care data. Methods: The developed Ontology-based Care Platform (OCarePlatform) consists of modular components that perform a specific reasoning task. Consequently, they can easily be replicated and distributed. Complex reasoning is achieved by combining the results of different components. To ensure that the components only receive information, which is of interest to them at that time, they are able to dynamically generate and register filter rules with a Semantic Communication Bus (SCB). This SCB semantically filters all the heterogeneous care data according to the registered rules by using a continuous care ontology. The SCB can be distributed and a cache can be employed to ensure scalability. Results: A prototype implementation is presented consisting of a new-generation nurse call system supported by a localization and a home automation component. The amount of data that is filtered and the performance of the SCB are evaluated by testing the prototype in a living lab. The delay introduced by processing the filter rules is negligible when 10 or fewer rules are registered. Conclusions: The OCarePlatform allows disseminating relevant care data for the different applications and additionally supports composing complex applications from a set of smaller independent components. This way, the platform significantly reduces the amount of information that needs to be processed by the nurses. The delay resulting from processing the filter rules is linear in the amount of rules. Distributed deployment of the SCB and using a cache allows further improvement of these performance results

Securities Purchase and Exchange Agreement

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