Methodology To Estimate Particulate Matter Emissions From Certified Commercial Aircraft Engines

Today, about one-fourth of U.S. commercial service airports, including 41 of the busiest 50, are either in nonattainment or maintenance areas per the National Ambient Air Quality Standards. U.S. aviation activity is forecasted to triple by 2025, while at the same time, the U.S. Environmental Protection Agency (EPA) is evaluating stricter particulate matter (PM) standards oA the basis of documented human health and welfare impacts. Stricter federal standards are expected to impede capacity and limit aviation growth if regulatory mandated emission reductions occur as for other non-aviation sources (i.e., automobiles, power plants, etc.). In addition, strong interest exists as to the role aviation emissiolis play in air quality and climate change issues. These reasons underpin the need to quantify and understand PM emissions from certified commercial aircraft engines, which has led to the need for a methodology to predict these emissions. Standardized sampling techniques to measure volatile and nonvolatile PM emissions from aircraft engines do not exist. As such, a first-order approximation (FOA) was derived to fill this need based on available information. FOA1.0 only allowed prediction of nonvolatile PM. FOA2.0 was a change to include volatlle PM emissions on the basis of the ratio of nonvolatile to volatile emissions. Recent collaborative efforts by industry (manufacturers and airlines), research establishments, and regulators have begun to provide further insight into the estimation of the PM emissions. The resultant PM measurement datasets are being analyzed to refine sampling techniques and progress towards standardized PM measurements. These preliminary measurement datasets also support the continued refinement of the FOA methodology. FOA3.0 dis-aggregated the prediction techniques to allow for independent prediction of nonvolatile ano volatile emissions on a more theoretical basis. The Committee for Aviation Environmental Protection of the International Civil Aviation Organization endorsed the use of FOA3.0 in February 2007. Further commitment was made to improve the FOA as new data become available, until such time the methodology is rendered obsolete by a fully validated database of PM emission indices for today\u27s certified commercial fleet. This paper discusses related assumptions and derived equations for the FOA3.0 methodology used worldwide to estimate PM emissions from certified commercial aircraft engines within the vicinity of airports. Copyright 2009 Air & Waste Management Association

Aedt Global NoX Demonstration

The Global NOx (Oxides of Nitrogen) demonstration is the first Capability Demonstrator (CD) sample problem of the Aviation Environmental Design Tool (AEDT). AEDT is intended to facilitate the analysis of tradeoffs between noise and emissions and make the evaluation of air quality and noise impact seamless between the local and global domains. This CD marks an initial step toward creating a harmonized air quality module suitable for local and global analyses by leveraging the work already invested in developing the Emissions and Dispersion Modeling System (EDMS), the System for assessing Aviation\u27s Global Emissions (SAGE), the Integrated Noise Model (INM), and the Model for Assessing Global Exposure from Noise of Transport Airplanes (MAGENTA). This initial CD focused on building a tool that assesses the impacts of different NOx stringencies to support the development of NOx emissions standards and highlights improvements over the previous modeling capabilities in many ways. AEDT implements Boeing Fuel Flow Method 2 (BFFM2) which allows for the use of thrust-specific emission indices corrected for atmospheric conditions, instead of relying on the sea level static certification data collected in the ICAO Aircraft Engine Exhaust Emissions Databank. BFFM2 is implemented in conjunction with a new, gate-to-gate, dynamic aircraft performance module based on the Society of Automotive Engineers\u27 Aerospace Information Report 1845 (SAE-AIR-1845) and EUROCONTROL\u27s Base of Aircraft Data (BADA). AEDT also implements input data processing enhancements to enable a more detailed fleet mix to be modeled. AEDT combines the International Official Airline Guide (IOAG) and FAA\u27s Enhanced Traffic Management System (ETMS) data with the CAEP-developed fleet forecast from their Forecasting and Economics Support Group (FESG) to produce a comprehensive global operations forecast. The resultant aircraft-type-specific route information, allows the results to be aggregated in multiple ways, as opposed to being limited to only assessing global performance. The methodologies used in this demonstration of AEDT capabilities are described in the paper

Flavonoids and hERG channels: Friends or foes?

The cardiac action potential is regulated by several ion channels. Drugs capable to block these channels, in particular the human ether-à-go-go-related gene (hERG) channel, also known as KV11.1 channel, may lead to a potentially lethal ventricular tachyarrhythmia called “Torsades de Pointes”. Thus, evaluation of the hERG channel off-target activity of novel chemical entities is nowadays required to safeguard patients as well as to avoid attrition in drug development. Flavonoids, a large class of natural compounds abundantly present in food, beverages, herbal medicines, and dietary food supplements, generally escape this assessment, though consumed in consistent amounts. Continuously growing evidence indicates that these compounds may interact with the hERG channel and block it. The present review, by examining numerous studies, summarizes the state-of-the-art in this field, describing the most significant examples of direct and indirect inhibition of the hERG channel current operated by flavonoids. A description of the molecular interactions between a few of these natural molecules and the Rattus norvegicus channel protein, achieved by an in silico approach, is also presented