Science.gov

Sample records for air transport models

  1. Synchronizing production and air transportation scheduling using mathematical programming models

    NASA Astrophysics Data System (ADS)

    Zandieh, M.; Molla-Alizadeh-Zavardehi, S.

    2009-08-01

    Traditional scheduling problems assume that there are always infinitely many resources for delivering finished jobs to their destinations, and no time is needed for their transportation, so that finished products can be transported to customers without delay. So, for coordination of these two different activities in the implementation of a supply chain solution, we studied the problem of synchronizing production and air transportation scheduling using mathematical programming models. The overall problem is decomposed into two sub-problems, which consists of air transportation allocation problem and a single machine scheduling problem which they are considered together. We have taken into consideration different constraints and assumptions in our modeling such as special flights, delivery tardiness and no delivery tardiness. For these purposes, a variety of models have been proposed to minimize supply chain total cost which encompass transportation, makespan, delivery earliness tardiness and departure time earliness tardiness costs.

  2. Air transport

    NASA Technical Reports Server (NTRS)

    Page, F Handley

    1924-01-01

    I purpose (sic) in this paper to deal with the development in air transport which has taken place since civil aviation between England and the Continent first started at the end of August 1919. A great deal of attention has been paid in the press to air services of the future, to the detriment of the consideration of results obtained up to the present.

  3. DESCRIPTION OF ATMOSPHERIC TRANSPORT PROCESSES IN EULERIAN AIR QUALITY MODELS

    EPA Science Inventory

    Key differences among many types of air quality models are the way atmospheric advection and turbulent diffusion processes are treated. Gaussian models use analytical solutions of the advection-diffusion equations. Lagrangian models use a hypothetical air parcel concept effecti...

  4. Air Quality Modeling Technical Support Document for the 2015 Ozone NAAQS Preliminary Interstate Transport Assessment

    EPA Pesticide Factsheets

    In this technical support document (TSD) EPA describes the air quality modeling performed to support the 2015 ozone National Ambient Air Quality Standards (NAAQS) preliminary interstate transport assessment Notice of Data Availability (NODA).

  5. Recommended direct simulation Monte Carlo collision model parameters for modeling ionized air transport processes

    SciTech Connect

    Swaminathan-Gopalan, Krishnan; Stephani, Kelly A.

    2016-02-15

    A systematic approach for calibrating the direct simulation Monte Carlo (DSMC) collision model parameters to achieve consistency in the transport processes is presented. The DSMC collision cross section model parameters are calibrated for high temperature atmospheric conditions by matching the collision integrals from DSMC against ab initio based collision integrals that are currently employed in the Langley Aerothermodynamic Upwind Relaxation Algorithm (LAURA) and Data Parallel Line Relaxation (DPLR) high temperature computational fluid dynamics solvers. The DSMC parameter values are computed for the widely used Variable Hard Sphere (VHS) and the Variable Soft Sphere (VSS) models using the collision-specific pairing approach. The recommended best-fit VHS/VSS parameter values are provided over a temperature range of 1000-20 000 K for a thirteen-species ionized air mixture. Use of the VSS model is necessary to achieve consistency in transport processes of ionized gases. The agreement of the VSS model transport properties with the transport properties as determined by the ab initio collision integral fits was found to be within 6% in the entire temperature range, regardless of the composition of the mixture. The recommended model parameter values can be readily applied to any gas mixture involving binary collisional interactions between the chemical species presented for the specified temperature range.

  6. COMIS -- an international multizone air-flow and contaminant transport model

    SciTech Connect

    Feustel, H.E.

    1998-08-01

    A number of interzonal models have been developed to calculate air flows and pollutant transport mechanisms in both single and multizone buildings. A recent development in multizone air-flow modeling, the COMIS model, has a number of capabilities that go beyond previous models, much as COMIS can be used as either a stand-alone air-flow model with input and output features or as an infiltration module for thermal building simulation programs. COMIS was designed during a 12 month workshop at Lawrence Berkeley National Laboratory (LBNL) in 1988-89. In 1990, the Executive Committee of the International Energy Agency`s Energy Conservation in Buildings and Community Systems program created a working group on multizone air-flow modeling, which continued work on COMIS. The group`s objectives were to study physical phenomena causing air flow and pollutant (e.g., moisture) transport in multizone buildings, develop numerical modules to be integrated in the previously designed multizone air flow modeling system, and evaluate the computer code. The working group supported by nine nations, officially finished in late 1997 with the release of IISiBat/COMIS 3.0, which contains the documented simulation program COMIS, the user interface IISiBat, and reports describing the evaluation exercise.

  7. Air transportation energy efficiency

    NASA Technical Reports Server (NTRS)

    Williams, L. J.

    1977-01-01

    The energy efficiency of air transportation, results of the recently completed RECAT studies on improvement alternatives, and the NASA Aircraft Energy Efficiency Research Program to develop the technology for significant improvements in future aircraft were reviewed.

  8. An Integrated Framework for Modeling Air Carrier Behavior, Policy, and Impacts in the U.S. Air Transportation System

    NASA Technical Reports Server (NTRS)

    Horio, Brant M.; Kumar, Vivek; DeCicco, Anthony H.; Hasan, Shahab; Stouffer, Virginia L.; Smith, Jeremy C.; Guerreiro, Nelson M.

    2015-01-01

    The implementation of the Next Generation Air Transportation System (NextGen) in the United States is an ongoing challenge for policymakers due to the complexity of the air transportation system (ATS) with its broad array of stakeholders and dynamic interdependencies between them. The successful implementation of NextGen has a hard dependency on the active participation of U.S. commercial airlines. To assist policymakers in identifying potential policy designs that facilitate the implementation of NextGen, the National Aeronautics and Space Administration (NASA) and LMI developed a research framework called the Air Transportation System Evolutionary Simulation (ATS-EVOS). This framework integrates large empirical data sets with multiple specialized models to simulate the evolution of the airline response to potential future policies and explore consequential impacts on ATS performance and market dynamics. In the ATS-EVOS configuration presented here, we leverage the Transportation Systems Analysis Model (TSAM), the Airline Evolutionary Simulation (AIRLINE-EVOS), the Airspace Concept Evaluation System (ACES), and the Aviation Environmental Design Tool (AEDT), all of which enable this research to comprehensively represent the complex facets of the ATS and its participants. We validated this baseline configuration of ATS-EVOS against Airline Origin and Destination Survey (DB1B) data and subject matter expert opinion, and we verified the ATS-EVOS framework and agent behavior logic through scenario-based experiments that explored potential implementations of a carbon tax, congestion pricing policy, and the dynamics for equipage of new technology by airlines. These experiments demonstrated ATS-EVOS's capabilities in responding to a wide range of potential NextGen-related policies and utility for decision makers to gain insights for effective policy design.

  9. Modeling the air-soil transport pathway of perfluorooctanoic acid in the mid-Ohio Valley using linked air dispersion and vadose zone models

    NASA Astrophysics Data System (ADS)

    Shin, Hyeong-Moo; Ryan, P. Barry; Vieira, Verónica M.; Bartell, Scott M.

    2012-05-01

    As part of an extensive modeling effort on the air-soil-groundwater transport pathway of perfluorooctanoic acid (PFOA), this study was designed to compare the performance of different air dispersion modeling systems (AERMOD vs. ISCST3), and different approaches to handling incomplete meteorological data using a data set with substantial soil measurements and a well characterized point source for air emissions. Two of the most commonly used EPA air dispersion models, AERMOD and ISCST3, were linked with the EPA vadose zone model PRZM-3. Predicted deposition rates from the air dispersion model were used as input values for the vadose zone model to estimate soil concentrations of PFOA at different depths. We applied 34 years of meteorological data including hourly surface measurements from Parkersburg Airport and 5 years of onsite wind direction and speed to the air dispersion models. We compared offsite measured soil concentrations to predictions made for the corresponding sampling depths, focusing on soil rather than air measurements because the offsite soil samples were less likely to be influenced by short-term variability in emission rates and meteorological conditions. PFOA concentrations in surface soil (0-30 cm depth) were under-predicted and those in subsurface soil (>30 cm depth) were over-predicted compared to observed concentrations by both linked air and vadose zone model. Overall, the simulated values from the linked modeling system were positively correlated with those observed in surface soil (Spearman's rho, Rsp = 0.59-0.70) and subsurface soil (Rsp = 0.46-0.48). This approach provides a useful modeling scheme for similar exposure and risk analyses where the air-soil-groundwater transport is a primary contamination pathway.

  10. Integrating air pollution modelling with scenario testing in road transport planning: the TRAEMS approach.

    PubMed

    Affum, J K; Brown, A L; Chan, Y C

    2003-08-01

    Transport add-on environmental modelling system (TRAEMS) is a GIS-based environmental modelling system designed to evaluate the environmental consequences of road traffic in urban areas. Its development has been underpinned by the premises that the evaluation of road traffic impacts is best undertaken during the early planning stages of road networks, and that this can utilise much of the data generated by the transport planners themselves as they apply their travel demand models as to planning of road networks. The system integrates information about traffic-usually from travel-forecasting models-with information about land use, to provide the input data to a range of commonly used models that estimate pollution from a road traffic system, and the energy consumption of that system. TRAEMS facilitates this integration and allows land use, transport and environmental planners to have rapid feedback on the environmental effects of road transport network scenarios that are being developed and tested. Its purpose is to aid in the selection of environmentally-preferred road networks and to highlight where management of pollution levels on future road networks will be required. TRAEMS has a modular structure. This paper describes the main features of the air pollution and fuel consumption modules of the system and illustrates the system's utility through case studies at both metropolitan-wide- and local-area scales.

  11. An integrated computer modeling environment for regional land use, air quality, and transportation planning

    SciTech Connect

    Hanley, C.J.; Marshall, N.L.

    1997-04-01

    The Land Use, Air Quality, and Transportation Integrated Modeling Environment (LATIME) represents an integrated approach to computer modeling and simulation of land use allocation, travel demand, and mobile source emissions for the Albuquerque, New Mexico, area. This environment provides predictive capability combined with a graphical and geographical interface. The graphical interface shows the causal relationships between data and policy scenarios and supports alternative model formulations. Scenarios are launched from within a Geographic Information System (GIS), and data produced by each model component at each time step within a simulation is stored in the GIS. A menu-driven query system is utilized to review link-based results and regional and area-wide results. These results can also be compared across time or between alternative land use scenarios. Using this environment, policies can be developed and implemented based on comparative analysis, rather than on single-step future projections. 16 refs., 3 figs., 2 tabs.

  12. Impact of air pollutants from surface transport sources on human health: A modeling and epidemiological approach.

    PubMed

    Aggarwal, Preeti; Jain, Suresh

    2015-10-01

    This study adopted an integrated 'source-to-receptor' assessment paradigm in order to determine the effects of emissions from passenger transport on urban air quality and human health in the megacity, Delhi. The emission modeling was carried out for the base year 2007 and three alternate (ALT) policy scenarios along with a business as usual (BAU) scenario for the year 2021. An Activity-Structure-Emission Factor (ASF) framework was adapted for emission modeling, followed by a grid-wise air quality assessment using AERMOD and a health impact assessment using an epidemiological approach. It was observed that a 2021-ALT-III scenario resulted in a maximum concentration reduction of ~24%, ~42% and ~58% for carbon monoxide (CO), nitrogen dioxide (NO2) and particulate matter (PM), respectively, compared to a 2021-BAU scenario. Further, it results in significant reductions in respiratory and cardiovascular mortality, morbidity and Disability Adjusted Life Years (DALY) by 41% and 58% on exposure to PM2.5 and NO2 concentrations when compared to the 2021-BAU scenario, respectively. In other words, a mix of proposed policy interventions namely the full-phased introduction of the Integrated Mass Transit System, fixed bus speed, stringent vehicle emission norms and a hike in parking fees for private vehicles would help in strengthening the capability of passenger transport to cater to a growing transport demand with a minimum health burden in the Delhi region. Further, the study estimated that the transport of goods would be responsible for ~5.5% additional VKT in the 2021-BAU scenario; however, it will contribute ~49% and ~55% additional NO2 and PM2.5 concentrations, respectively, in the Delhi region. Implementation of diesel particulate filters for goods vehicles in the 2021-ALT-IV-O scenario would help in the reduction of ~87% of PM2.5 concentration, compared to the 2021-BAU scenario; translating into a gain of 1267 and 505 DALY per million people from exposure to PM2.5 and NO

  13. An effort for developing a seamless transport modeling and remote sensing system for air pollutants

    NASA Astrophysics Data System (ADS)

    Nakajima, T.; Goto, D.; Dai, T.; Misawa, S.; Uchida, J.; Schutgens, N.; Hashimoto, M.; Oikawa, E.; Takenaka, H.; Tsuruta, H.; Inoue, T.; Higurashi, A.

    2015-12-01

    Wide area of the globe, like Asian region, still suffers from a large emission of air pollutants and cause serious impacts on the earth's climate and the public health of the area. Launch of an international initiative, Climate and Clean Air Coalition (CCAC), is an example of efforts to ease the difficulties by reducing Short-Lived Climate Pollutants (SLCPs), i.e., black carbon aerosol, methane and other short-lived atmospheric materials that heat the earth's system, along with long-lived greenhouse gas mitigation. Impact evaluation of the air pollutants, however, has large uncertainties. We like to introduce a recent effort of projects MEXT/SALSA and MOEJ/S-12 to develop a seamless transport model for atmospheric constituents, NICAM-Chem, that is flexible enough to cover global scale to regional scale by the NICAM nonhydrostatic dynamic core (NICAM), coupled with SPRINTARS aerosol model, CHASER atmospheric chemistry model and with their three computational grid systems, i.e. quasi homogeneous grids, stretched grids and diamond grids. A local ensemble transform Kalman filter/smoother with this modeling system was successfully applied to data from MODIS, AERONET, and CALIPSO for global assimilation/inversion and surface SPM and SO2 air pollution monitoring networks for Japanese area assimilation. My talk will be extended to discuss an effective utility of satellite remote sensing of aerosols using Cloud and Aerosol Imager (CAI) on board the GOSAT satellite and Advanced Himawari Imager (AHI) on board the new third generation geostationary satellite, Himawari-8. The CAI has a near-ultraviolet channel of 380nm with 500m spatial resolution and the AHI has high frequency measurement capability of every 10 minutes. These functions are very effective for accurate land aerosol remote sensing, so that a combination with the developed aerosol assimilation system is promising.

  14. Urban airshed modeling of air quality impacts of alternative transportation fuel use in Los Angeles and Atlanta

    SciTech Connect

    1997-12-01

    The main objective of NREL in supporting this study is to determine the relative air quality impact of the use of compressed natural gas (CNG) as an alternative transportation fuel when compared to low Reid vapor pressure (RVP) gasoline and reformulated gasoline (RFG). A table lists the criteria, air toxic, and greenhouse gas pollutants for which emissions were estimated for the alternative fuel scenarios. Air quality impacts were then estimated by performing photochemical modeling of the alternative fuel scenarios using the Urban Airshed Model Version 6.21 and the Carbon Bond Mechanism Version IV (CBM-IV) (Geary et al., 1988) Using this model, the authors examined the formation and transport of ozone under alternative fuel strategies for motor vehicle transportation sources for the year 2007. Photochemical modeling was performed for modeling domains in Los Angeles, California, and Atlanta, Georgia.

  15. The development of a model for predicting passenger acceptance of short-haul air transportation systems

    NASA Technical Reports Server (NTRS)

    Kuhlthau, A. R.; Jacobson, I. D.

    1977-01-01

    Meaningful criteria and methodology for assessing, particularly in the area of ride quality, the potential acceptability to the traveling public of present and future transportation systems were investigated. Ride quality was found to be one of the important variables affecting the decision of users of air transportation, and to be influenced by several environmental factors, especially motion, noise, pressure, temperature, and seating. Models were developed to quantify the relationship of subjective comfort to all of these parameters and then were exercised for a variety of situations. Passenger satisfaction was found to be strongly related to ride quality and was so modeled. A computer program was developed to assess the comfort and satisfaction levels of passengers on aircraft subjected to arbitrary flight profiles over arbitrary terrain. A model was deduced of the manner in which passengers integrate isolated segments of a flight to obtain an overall trip comfort rating. A method was established for assessing the influence of other links (e.g., access, terminal conditions) in the overall passenger trip.

  16. The Market Demand for Air Transportation

    NASA Technical Reports Server (NTRS)

    Taneja, N.

    1972-01-01

    Although the presentation will touch upon the areas of market for air transportation, the theoretical foundations of the demand function, the demand models, and model selection and evaluation, the emphasis of the presentation will be on a qualitative description of the factors affecting the demand for air transportation. The presentation will rely heavily on the results of market surveys carried out by the Port of New York Authority, the University of Michigan, and Census of Transportation.

  17. MODELING ASSESSMENT OF TRANSPORT AND DEPOSITION PATTERNS OF MERCURY AIR EMISSIONS FROM THE U.S. AND CANADA

    EPA Science Inventory

    In December 1997, the U.S. EPA submitted the Mercury Study Report to Congress which included a regional-scale modeling assessment of the transport and deposition of U.S. air emissions of mercury. This modeling was performed with a modified version of the Regional Lagrangian Mode...

  18. SPECIES - EVALUATING THERMODYNAMIC PROPERTIES, TRANSPORT PROPERTIES & EQUILIBRIUM CONSTANTS OF AN 11-SPECIES AIR MODEL

    NASA Technical Reports Server (NTRS)

    Thompson, R. A.

    1994-01-01

    Accurate numerical prediction of high-temperature, chemically reacting flowfields requires a knowledge of the physical properties and reaction kinetics for the species involved in the reacting gas mixture. Assuming an 11-species air model at temperatures below 30,000 degrees Kelvin, SPECIES (Computer Codes for the Evaluation of Thermodynamic Properties, Transport Properties, and Equilibrium Constants of an 11-Species Air Model) computes values for the species thermodynamic and transport properties, diffusion coefficients and collision cross sections for any combination of the eleven species, and reaction rates for the twenty reactions normally occurring. The species represented in the model are diatomic nitrogen, diatomic oxygen, atomic nitrogen, atomic oxygen, nitric oxide, ionized nitric oxide, the free electron, ionized atomic nitrogen, ionized atomic oxygen, ionized diatomic nitrogen, and ionized diatomic oxygen. Sixteen subroutines compute the following properties for both a single species, interaction pair, or reaction, and an array of all species, pairs, or reactions: species specific heat and static enthalpy, species viscosity, species frozen thermal conductivity, diffusion coefficient, collision cross section (OMEGA 1,1), collision cross section (OMEGA 2,2), collision cross section ratio, and equilibrium constant. The program uses least squares polynomial curve-fits of the most accurate data believed available to provide the requested values more quickly than is possible with table look-up methods. The subroutines for computing transport coefficients and collision cross sections use additional code to correct for any electron pressure when working with ionic species. SPECIES was developed on a SUN 3/280 computer running the SunOS 3.5 operating system. It is written in standard FORTRAN 77 for use on any machine, and requires roughly 92K memory. The standard distribution medium for SPECIES is a 5.25 inch 360K MS-DOS format diskette. The contents of the

  19. Mammoth Lakes Route 203 transportation project: a case study in air-quality modeling and mitigation. Final report

    SciTech Connect

    Benson, P.; Nokes, W.; Cramer, R.

    1985-06-01

    An evaluation is made of the effects on carbon monoxide concentrations of transportation improvements incorporated in the Route 203 highway project. This includes a comparison of preconstruction and postconstruction field-sampling studies. The performance of the CALINE4 air-quality model is evaluated for use in complex terrain. The report describes the problems encountered in applying the model to mountainous locations, the tracer-release study used for assessing model performance, and the model-verification analysis.

  20. Intercontinental Transport of Air Pollution

    NASA Technical Reports Server (NTRS)

    Rogers, David; Whung, Pai-Yei; Einaudi, Franco (Technical Monitor)

    2001-01-01

    The development of the global economy goes beyond raising our standards of living. We are in an ear of increasing environmental as well as economic interdependence. Long-range transport of anthropogenic atmospheric pollutants such as ozone, ozone precursors, airborne particles, heavy metals (such as mercury) and persistent organic pollutants are the four major types of pollution that are transported over intercontinental distances and have global environmental effects. The talk includes: 1) an overview of the international agreements related to intercontinental transport of air pollutants, 2) information needed for decision making, 3) overview of the past research on intercontinental transport of air pollutants - a North American's perspective, and 4) future research needs.

  1. Comparing three vegetation monoterpene emission models to measured gas concentrations with a model of meteorology, air chemistry and chemical transport

    NASA Astrophysics Data System (ADS)

    Smolander, S.; He, Q.; Mogensen, D.; Zhou, L.; Bäck, J.; Ruuskanen, T.; Noe, S.; Guenther, A.; Aaltonen, H.; Kulmala, M.; Boy, M.

    2013-11-01

    Biogenic volatile organic compounds (BVOCs) are essential in atmospheric chemistry because of their chemical reactions that produce and destroy tropospheric ozone, their effects on aerosol formation and growth, and their potential influence on global warming. As one of the important BVOC groups, monoterpenes have been a focus of scientific attention in atmospheric research. Detailed regional measurements and model estimates are needed to study emission potential and the monoterpene budget on a global scale. Since the use of empirical measurements for upscaling is limited by many physical and biological factors such as genetic variation, temperature and light, water availability, seasonal changes, and environmental stresses, comprehensive inventories over larger areas are difficult to obtain. We applied the boundary layer-chemistry-transport model SOSA to investigate Scots pine (Pinus sylvestris) monoterpene emissions in a boreal coniferous forest at the SMEAR II site, Southern Finland. SOSA was applied to simulate monoterpene emissions with three different emission modules: the semi-empirical G95, MEGAN 2.04 with improved descriptions of temperature and light responses and including also carbonyl emissions, and a process-based model SIM-BIM. For the first time, the emission models included seasonal and diurnal variations in both quantity and chemical species of emitted monoterpenes, based on parameterizations obtained from field measurements. Results indicate that modelling and observations agreed reasonably well, and that the model can be used for investigating regional air chemistry questions related to monoterpenes. The predominant modelled monoterpene concentrations, α-pinene and Δ3-carene, are consistent with observations.

  2. Energy conservation and air transportation

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Air transportation demand and passenger energy demand are discussed, in relation to energy conservation. Alternatives to air travel are reviewed, along with airline advertising and ticket pricing. Cargo energy demand and airline systems efficiency are also examined, as well as fuel conservation techniques. Maximum efficiency of passenger aircraft, from B-747 to V/STOL to British Concorde, is compared.

  3. Comparing three vegetation monoterpene emission models to measured gas concentrations with a model of meteorology, air chemistry and chemical transport

    NASA Astrophysics Data System (ADS)

    Smolander, S.; He, Q.; Mogensen, D.; Zhou, L.; Bäck, J.; Ruuskanen, T.; Noe, S.; Guenther, A.; Aaltonen, H.; Kulmala, M.; Boy, M.

    2014-10-01

    Biogenic volatile organic compounds (BVOCs) are essential in atmospheric chemistry because of their chemical reactions that produce and destroy tropospheric ozone, their effects on aerosol formation and growth, and their potential influence on global warming. As one of the important BVOC groups, monoterpenes have been a focus of scientific attention in atmospheric research. Detailed regional measurements and model estimates are needed to study emission potential and the monoterpene budget on a global scale. Since the use of empirical measurements for upscaling is limited by many physical and biological factors, such as genetic variation, temperature and light, water availability, seasonal changes, and environmental stresses, comprehensive inventories over larger areas are difficult to obtain. We applied the boundary-layer-chemistry-transport model SOSA (model to Simulate the concentrations of Organic vapours and Sulphuric Acid) to investigate Scots pine (Pinus sylvestris) monoterpene emissions in a boreal coniferous forest at the SMEAR (Station for Measuring forest Ecosystem-Atmosphere Relations) II site, southern Finland. SOSA was applied to simulate monoterpene emissions with three different emission modules: the semiempirical G95, MEGAN (Model of Emissions of Gases and Aerosols from Nature) 2.04 with improved descriptions of temperature and light responses and including also carbonyl emissions, and a process-based model SIM-BIM (Seasonal Isoprenoid synthase Model - Biochemical Isoprenoid biosynthesis Model). For the first time, the emission models included seasonal and diurnal variations in both quantity and chemical species of emitted monoterpenes, based on parameterizations obtained from field measurements. Results indicate that modelling and observations agreed reasonably well and that the model can be used for investigating regional air chemistry questions related to monoterpenes. The predominant modelled monoterpene concentrations, α-pinene and Δ3-carene

  4. Rotorcraft air transportation

    NASA Technical Reports Server (NTRS)

    Gilbert, G. A.

    1983-01-01

    Intermodal relationships and the particular ways in which they affect public transportation applications of rotorcraft are addressed. Some aspects of integrated services and general comparisons with other transportation modes are reviewed. Two potential application scenarios are discussed: down-to-downtown rotorcraft service and urban public transport rotorcraft service. It is concluded that to integrate well with ground access modes community rotorcraft service should be limited stop service with published schedules, and operate on a few specific routes between a few specific destinations. For downtown-to-downtown service, time savings favorable to rotorcraft are benefits that reflect its more direct access, relatively higher line-haul travel speeds, and less circuitous travel. For the scenario of public transport within urban areas, first, improving cruise speeds has a limited potential due to allowing for a ""station spacing'' effect. Secondly, public acceptance of higher acceleration/deceleration rates may be just as effective as a technological innovation as achieving higher cruise speeds.

  5. Optimizing Air Transportation Service to Metroplex Airports. Par 2; Analysis Using the Airline Schedule Optimization Model (ASOM)

    NASA Technical Reports Server (NTRS)

    Donoue, George; Hoffman, Karla; Sherry, Lance; Ferguson, John; Kara, Abdul Qadar

    2010-01-01

    The air transportation system is a significant driver of the U.S. economy, providing safe, affordable, and rapid transportation. During the past three decades airspace and airport capacity has not grown in step with demand for air transportation; the failure to increase capacity at the same rate as the growth in demand results in unreliable service and systemic delay. This report describes the results of an analysis of airline strategic decision-making that affects geographic access, economic access, and airline finances, extending the analysis of these factors using historic data (from Part 1 of the report). The Airline Schedule Optimization Model (ASOM) was used to evaluate how exogenous factors (passenger demand, airline operating costs, and airport capacity limits) affect geographic access (markets-served, scheduled flights, aircraft size), economic access (airfares), airline finances (profit), and air transportation efficiency (aircraft size). This analysis captures the impact of the implementation of airport capacity limits, as well as the effect of increased hedged fuel prices, which serve as a proxy for increased costs per flight that might occur if auctions or congestion pricing are imposed; also incorporated are demand elasticity curves based on historical data that provide information about how passenger demand is affected by airfare changes.

  6. Diagnostic Evaluation of Ozone Production and Horizontal Transport in a Regional Photochemical Air Quality Modeling System

    EPA Science Inventory

    A diagnostic model evaluation effort has been performed to focus on photochemical ozone formation and the horizontal transport process since they strongly impact the temporal evolution and spatial distribution of ozone (O3) within the lower troposphere. Results from th...

  7. Transportation, Air Pollution, and Climate Change

    MedlinePlus

    ... Share Facebook Twitter Google+ Pinterest Contact Us Transportation, Air Pollution, and Climate Change Accomplishments & Successes View successes from ... reduce carbon pollution. Carbon pollution from transportation Other Air Pollution Learn about smog, soot, ozone, and other air ...

  8. Assessment of potential long-range transport of particulate air pollution using trajectory modeling and monitoring data

    NASA Astrophysics Data System (ADS)

    Pongkiatkul, Prapat; Kim Oanh, Nguyen Thi

    2007-07-01

    Quantification of the long-range transport (LRT) contribution to ambient air pollution levels at a location is a challenging task and is normally done with a high uncertainty. In the lack of accurate emission data over the large regional domain for dispersion modeling, this study attempts to use both trajectory analysis and monitoring data to assess the potential contribution of LRT to particulate air pollution (PM) in the Bangkok Metropolitan Region (BMR). The 10-day backward trajectories of air masses arriving at BMR from January 2002 to December 2004 were determined using Hybrid Single-Particle Langrangian Integrated Trajectory model version 4 (HYSPLIT4) and were categorized by k-means clustering into 6 clusters. Subsequently, PM levels in the BMR associated with each air mass cluster during this period were analyzed. Clusters 1 and 6 were observed with the highest and 2nd highest average PM 10 and PM 2.5 levels in the BMR, respectively, which commonly have a longer air mass pathway over populated South East Asia (SEA). The third highest PM levels were associated with air masses from the east (clusters 2 and 5), which enter the BMR via the Gulf of Thailand without passing the SEA regions. The other two clusters (3 and 4) are characterized with a long pathway of air masses over the Indian Ocean and the lowest PM levels. High PM days, which are defined based on the spatial coverage of high PM levels in the BMR, were identified and analyzed for the possibility of long-range transport contribution of PM. The potential source contribution function (PSCF) and air mass trajectories show that on high PM day, the air masses commonly originated and passed over populated regions before arriving at the BMR, which suggests a possible LRT contribution. Considerations are made for surface ozone, SO 42-/SO 2 and average SO 2, PM 2.5/PM 10, and weekday-weekend traffic emission within each air mass trajectory cluster to reveal the possible LRT contribution.

  9. Systemic Analysis Approaches for Air Transportation

    NASA Technical Reports Server (NTRS)

    Conway, Sheila

    2005-01-01

    Air transportation system designers have had only limited success using traditional operations research and parametric modeling approaches in their analyses of innovations. They need a systemic methodology for modeling of safety-critical infrastructure that is comprehensive, objective, and sufficiently concrete, yet simple enough to be used with reasonable investment. The methodology must also be amenable to quantitative analysis so issues of system safety and stability can be rigorously addressed. However, air transportation has proven itself an extensive, complex system whose behavior is difficult to describe, no less predict. There is a wide range of system analysis techniques available, but some are more appropriate for certain applications than others. Specifically in the area of complex system analysis, the literature suggests that both agent-based models and network analysis techniques may be useful. This paper discusses the theoretical basis for each approach in these applications, and explores their historic and potential further use for air transportation analysis.

  10. Method for Fusing Observational Data and Chemical Transport Model Simulations To Estimate Spatiotemporally Resolved Ambient Air Pollution.

    PubMed

    Friberg, Mariel D; Zhai, Xinxin; Holmes, Heather A; Chang, Howard H; Strickland, Matthew J; Sarnat, Stefanie Ebelt; Tolbert, Paige E; Russell, Armistead G; Mulholland, James A

    2016-04-05

    Investigations of ambient air pollution health effects rely on complete and accurate spatiotemporal air pollutant estimates. Three methods are developed for fusing ambient monitor measurements and 12 km resolution chemical transport model (CMAQ) simulations to estimate daily air pollutant concentrations across Georgia. Temporal variance is determined by observations in one method, with the annual mean CMAQ field providing spatial structure. A second method involves scaling daily CMAQ simulated fields using mean observations to reduce bias. Finally, a weighted average of these results based on prediction of temporal variance provides optimized daily estimates for each 12 × 12 km grid. These methods were applied to daily metrics of 12 pollutants (CO, NO2, NOx, O3, SO2, PM10, PM2.5, and five PM2.5 components) over the state of Georgia for a seven-year period (2002-2008). Cross-validation demonstrates a wide range in optimized model performance across pollutants, with SO2 predicted most poorly due to limitations in coal combustion plume monitoring and modeling. For the other pollutants studied, 54-88% of the spatiotemporal variance (Pearson R(2) from cross-validation) was captured, with ozone and PM2.5 predicted best. The optimized fusion approach developed provides daily spatial field estimates of air pollutant concentrations and uncertainties that are consistent with observations, emissions, and meteorology.

  11. 22 CFR 228.22 - Air transportation.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Air transportation. 228.22 Section 228.22... for USAID Financing § 228.22 Air transportation. (a) The eligibility of air transportation is determined by the flag registry of the aircraft. The term “U.S. flag air carrier” means one of a class of...

  12. 22 CFR 228.22 - Air transportation.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Air transportation. 228.22 Section 228.22... for USAID Financing § 228.22 Air transportation. (a) The eligibility of air transportation is determined by the flag registry of the aircraft. The term “U.S. flag air carrier” means one of a class of...

  13. Investigating the role of transportation models in epidemiologic studies of traffic related air pollution and health effects.

    PubMed

    Shekarrizfard, Maryam; Valois, Marie-France; Goldberg, Mark S; Crouse, Dan; Ross, Nancy; Parent, Marie-Elise; Yasmin, Shamsunnahar; Hatzopoulou, Marianne

    2015-07-01

    In two earlier case-control studies conducted in Montreal, nitrogen dioxide (NO2), a marker for traffic-related air pollution was found to be associated with the incidence of postmenopausal breast cancer and prostate cancer. These studies relied on a land use regression model (LUR) for NO2 that is commonly used in epidemiologic studies for deriving estimates of traffic-related air pollution. Here, we investigate the use of a transportation model developed during the summer season to generate a measure of traffic emissions as an alternative to the LUR model. Our traffic model provides estimates of emissions of nitrogen oxides (NOx) at the level of individual roads, as does the LUR model. Our main objective was to compare the distribution of the spatial estimates of NOx computed from our transportation model to the distribution obtained from the LUR model. A secondary objective was to compare estimates of risk using these two exposure estimates. We observed that the correlation (spearman) between our two measures of exposure (NO2 and NOx) ranged from less than 0.3 to more than 0.9 across Montreal neighborhoods. The most important factor affecting the "agreement" between the two measures in a specific area was found to be the length of roads. Areas affected by a high level of traffic-related air pollution had a far better agreement between the two exposure measures. A comparison of odds ratios (ORs) obtained from NO2 and NOx used in two case-control studies of breast and prostate cancer, showed that the differences between the ORs associated with NO2 exposure vs NOx exposure differed by 5.2-8.8%.

  14. Modelling and prediction of air pollutant transport during the 2014 biomass burning and forest fires in peninsular Southeast Asia.

    PubMed

    Duc, Hiep Nguyen; Bang, Ho Quoc; Quang, Ngo Xuan

    2016-02-01

    During the dry season, from November to April, agricultural biomass burning and forest fires especially from March to late April in mainland Southeast Asian countries of Myanmar, Thailand, Laos and Vietnam frequently cause severe particulate pollution not only in the local areas but also across the whole region and beyond due to the prevailing meteorological conditions. Recently, the BASE-ASIA (Biomass-burning Aerosols in South East Asia: Smoke Impact Assessment) and 7-SEAS (7-South-East Asian Studies) studies have provided detailed analysis and important understandings of the transport of pollutants, in particular, the aerosols and their characteristics across the region due to biomass burning in Southeast Asia (SEA). Following these studies, in this paper, we study the transport of particulate air pollution across the peninsular region of SEA and beyond during the March 2014 burning period using meteorological modelling approach and available ground-based and satellite measurements to ascertain the extent of the aerosol pollution and transport in the region of this particular event. The results show that the air pollutants from SEA biomass burning in March 2014 were transported at high altitude to southern China, Hong Kong, Taiwan and beyond as has been highlighted in the BASE-ASIA and 7-SEAS studies. There are strong evidences that the biomass burning in SEA especially in mid-March 2014 has not only caused widespread high particle pollution in Thailand (especially the northern region where most of the fires occurred) but also impacted on the air quality in Hong Kong as measured at the ground-based stations and in LulinC (Taiwan) where a remote background monitoring station is located.

  15. Computer codes for the evaluation of thermodynamic properties, transport properties, and equilibrium constants of an 11-species air model

    NASA Technical Reports Server (NTRS)

    Thompson, Richard A.; Lee, Kam-Pui; Gupta, Roop N.

    1990-01-01

    The computer codes developed provide data to 30000 K for the thermodynamic and transport properties of individual species and reaction rates for the prominent reactions occurring in an 11-species nonequilibrium air model. These properties and the reaction-rate data are computed through the use of curve-fit relations which are functions of temperature (and number density for the equilibrium constant). The curve fits were made using the most accurate data believed available. A detailed review and discussion of the sources and accuracy of the curve-fitted data used herein are given in NASA RP 1232.

  16. A Seasonal Air Transport Climatology for Kenya

    NASA Technical Reports Server (NTRS)

    Gatebe, C. K.; Tyson, P. D.; Annegarn, H.; Piketh, S.; Helas, G.

    1998-01-01

    A climatology of air transport to and from Kenya has been developed using kinematic trajectory modeling. Significant months for trajectory analysis have been determined from a classification of synoptic circulation fields. Five-point back and forward trajectory clusters to and from Kenya reveal that the transport corridors to Kenya are clearly bounded and well defined. Air reaching the country originates mainly from the Saharan region and northwestern Indian Ocean of the Arabian Sea in the northern hemisphere and from the Madagascan region of the Indian Ocean in the southern hemisphere. Transport from each of these source regions show distinctive annual cycles related to the northeasterly Asian monsoon and the southeasterly trade wind maximum over Kenya in May. The Saharan transport in the lower troposphere is at a maximum when the subtropical high over northern Africa is strongly developed in the boreal winter. Air reaching Kenya between 700 and 500 hPa is mainly from Sahara and northwest India Ocean flows in the months of January and March, which gives way to southwest Indian Ocean flow in May and November. In contrast, air reaching Kenya at 400 hPa is mainly from southwest Indian Ocean in January and March, which is replaced by Saharan transport in May and November. Transport of air from Kenya is invariant, both spatially and temporally, in the tropical easterlies to the Congo Basin and Atlantic Ocean in comparison to the transport to the country. Recirculation of air has also been observed, but on a limited and often local scale and not to the extent reported in southern Africa.

  17. The Integrated Air Transportation System Evaluation Tool

    NASA Technical Reports Server (NTRS)

    Wingrove, Earl R., III; Hees, Jing; Villani, James A.; Yackovetsky, Robert E. (Technical Monitor)

    2002-01-01

    Throughout U.S. history, our nation has generally enjoyed exceptional economic growth, driven in part by transportation advancements. Looking forward 25 years, when the national highway and skyway systems are saturated, the nation faces new challenges in creating transportation-driven economic growth and wealth. To meet the national requirement for an improved air traffic management system, NASA developed the goal of tripling throughput over the next 20 years, in all weather conditions while maintaining safety. Analysis of the throughput goal has primarily focused on major airline operations, primarily through the hub and spoke system.However, many suggested concepts to increase throughput may operate outside the hub and spoke system. Examples of such concepts include the Small Aircraft Transportation System, civil tiltrotor, and improved rotorcraft. Proper assessment of the potential contribution of these technologies to the domestic air transportation system requires a modeling capability that includes the country's numerous smaller airports, acting as a fundamental component of the National Air space System, and the demand for such concepts and technologies. Under this task for NASA, the Logistics Management Institute developed higher fidelity demand models that capture the interdependence of short-haul air travel with other transportation modes and explicitly consider the costs of commercial air and other transport modes. To accomplish this work, we generated forecasts of the distribution of general aviation based aircraft and GA itinerant operations at each of nearly 3.000 airport based on changes in economic conditions and demographic trends. We also built modules that estimate the demand for travel by different modes, particularly auto, commercial air, and GA. We examined GA demand from two perspectives: top-down and bottom-up, described in detail.

  18. Quantitative Evaluation of an Air-monitoring Network Using Atmospheric Transport Modeling and Frequency of Detection Methods.

    PubMed

    Rood, Arthur S; Sondrup, A Jeffrey; Ritter, Paul D

    2016-04-01

    A methodology has been developed to quantify the performance of an air-monitoring network in terms of frequency of detection. Frequency of detection is defined as the fraction of "events" that result in a detection at either a single sampler or network of samplers. An "event" is defined as a release to the atmosphere of a specified amount of activity over a finite duration that begins on a given day and hour of the year. The methodology uses an atmospheric transport model to predict air concentrations of radionuclides at the samplers for a given release time and duration. Another metric of interest determined by the methodology is called the network intensity, which is defined as the fraction of samplers in the network that have a positive detection for a given event. The frequency of detection methodology allows for evaluation of short-term releases that include effects of short-term variability in meteorological conditions. The methodology was tested using the U.S. Department of Energy Idaho National Laboratory Site ambient air-monitoring network consisting of 37 low-volume air samplers in 31 different locations covering a 17,630 km region. Releases from six major facilities distributed over an area of 1,435 km were modeled and included three stack sources and eight ground-level sources. A Lagrangian Puff air dispersion model (CALPUFF) was used to model atmospheric transport. The model was validated using historical Sb releases and measurements. Relevant 1-wk release quantities from each emission source were calculated based on a dose of 1.9×10 mSv at a public receptor (0.01 mSv assuming release persists over a year). Important radionuclides were Am, Cs, Pu, Pu, Sr, and tritium. Results show the detection frequency was over 97.5% for the entire network considering all sources and radionuclides. Network intensity results ranged from 3.75% to 62.7%. Evaluation of individual samplers indicated some samplers were poorly located and added little to the overall

  19. Groundwater flow and contaminant transport modelling at an air weapons range

    NASA Astrophysics Data System (ADS)

    Bordeleau, Geneviève; Martel, Richard; Schäfer, Dirk; Ampleman, Guy; Thiboutot, Sonia

    2008-07-01

    Numerical modelling was done at the Cold Lake Air Weapons Range, Canada, to test whether the dissolved RDX and nitrate detected in groundwater come from the same sources, and to predict whether contamination poses a threat to the surface water receptors near the site. Military live fire training activities may indeed pose a risk of contamination to groundwater resources, however field investigations on military bases are quite recent, and little information is available on the long-term behaviour of munition residues related contaminants. Very limited information was available about the contaminant source zones, which were assigned based on our knowledge of current training activities. The RDX plume was well represented with the model, but the heterogeneous distribution of nitrate concentrations was more difficult to reproduce. It was nonetheless determined that both contaminants originate from the same areas. According to the model, both contaminants should reach the nearby river, but concentrations in the river should remain very low if the source zone concentration does not change. Finally, the model allowed the recommendation of a new location for the main bombing target, which would offer added protection to the river and the lake into which it flows.

  20. Large scale air pollution estimation method combining land use regression and chemical transport modeling in a geostatistical framework.

    PubMed

    Akita, Yasuyuki; Baldasano, Jose M; Beelen, Rob; Cirach, Marta; de Hoogh, Kees; Hoek, Gerard; Nieuwenhuijsen, Mark; Serre, Marc L; de Nazelle, Audrey

    2014-04-15

    In recognition that intraurban exposure gradients may be as large as between-city variations, recent air pollution epidemiologic studies have become increasingly interested in capturing within-city exposure gradients. In addition, because of the rapidly accumulating health data, recent studies also need to handle large study populations distributed over large geographic domains. Even though several modeling approaches have been introduced, a consistent modeling framework capturing within-city exposure variability and applicable to large geographic domains is still missing. To address these needs, we proposed a modeling framework based on the Bayesian Maximum Entropy method that integrates monitoring data and outputs from existing air quality models based on Land Use Regression (LUR) and Chemical Transport Models (CTM). The framework was applied to estimate the yearly average NO2 concentrations over the region of Catalunya in Spain. By jointly accounting for the global scale variability in the concentration from the output of CTM and the intraurban scale variability through LUR model output, the proposed framework outperformed more conventional approaches.

  1. A fugacity approach for modeling the transport of airborne organic chemicals in an air/plant/soil system

    SciTech Connect

    Oliver, L.D. ); McKone, T.E. )

    1991-05-01

    An important issue facing both public and private agencies is the identification and quantification of exposures by indirect pathways to toxic chemicals released to the atmosphere. With recent public concerns over pesticides such as malathion and alar in foods, greater attention is being given to the process of chemical uptake by plants. Whether chemicals taken up by plants can accumulate and ultimately enter the human food chain are important questions for determining health risks and safe levels of toxic air-pollutant emissions and pesticide application. A number of plant-toxicokinetic, or botanicokinetic,'' models have been developed to give estimates of how chemicals are partitioned and transported within plants. In this paper, we provide a brief review of these models, describing their main features and listing some of their advantages and disadvantages. We then describe and demonstrate a five-compartment air/plant/soil model, which builds on and extends the features included in previous models. We apply this model to the steady-state chemical partitioning of perchloroethylene, hexachlorobenzene, and 2,3,7,8-tetrachlorodibenzo-p-dioxin in grass as test cases. We conclude with a discussion of the advantages and limitations of the model.

  2. A fugacity approach for modeling the transport of airborne organic chemicals in an air/plant/soil system

    SciTech Connect

    Oliver, L.D.; McKone, T.E.

    1991-05-01

    An important issue facing both public and private agencies is the identification and quantification of exposures by indirect pathways to toxic chemicals released to the atmosphere. With recent public concerns over pesticides such as malathion and alar in foods, greater attention is being given to the process of chemical uptake by plants. Whether chemicals taken up by plants can accumulate and ultimately enter the human food chain are important questions for determining health risks and safe levels of toxic air-pollutant emissions and pesticide application. A number of plant-toxicokinetic, or ``botanicokinetic,`` models have been developed to give estimates of how chemicals are partitioned and transported within plants. In this paper, we provide a brief review of these models, describing their main features and listing some of their advantages and disadvantages. We then describe and demonstrate a five-compartment air/plant/soil model, which builds on and extends the features included in previous models. We apply this model to the steady-state chemical partitioning of perchloroethylene, hexachlorobenzene, and 2,3,7,8-tetrachlorodibenzo-p-dioxin in grass as test cases. We conclude with a discussion of the advantages and limitations of the model.

  3. Development of the Air Transport Industry

    NASA Technical Reports Server (NTRS)

    Taneja, N.

    1972-01-01

    The major developments are outlined in the U.S. scheduled air transport industry both domestic and international, together with a brief history of the European air transport system. The role and formulation of the U.S. Civil Aeronautics Board, International Civil Aviation Organization, and International Air Transport Association are also covered.

  4. Chemical Transport and Reduced-Form Models for Assessing Air Quality Impacts of Current and Future Energy Scenarios

    NASA Astrophysics Data System (ADS)

    Adams, P. J.

    2015-12-01

    Though essential for informed decision-making, it is challenging to estimate the air quality and public health impacts associated with current and future energy generation scenarios because the analysis must address the complicated atmospheric processes that air pollutants undergo: emissions, dispersion, chemistry, and removal. Employing a chemical transport model (CTM) is the most rigorous way to address these atmospheric processes. However, CTMs are expensive from a computational standpoint and, therefore, beyond the reach of policy analysis for many types of problems. On the other hand, previously available reduced-form models used for policy analysis fall short of the rigor of CTMs and may lead to biased results. To address this gap, we developed the Estimating Air pollution Social Impacts Using Regression (EASIUR) method, which builds parameterizations that predict per-tonne social costs and intake fractions for pollutants emitted from any location in the United States. Derived from a large database of tagged CTM simulations, the EASIUR method predicts social costs almost indistinguishable from a full CTM but with negligible computational requirements. We found that the average mortality-related social costs from inorganic PM2.5 and its precursors in the United States are 150,000-180,000/t EC, 21,000-34,000/t SO2, 4,200-15,000/t NOx, and 29,000-85,000/t NH3. This talk will demonstrate examples of using both CTMs and reduced-form models for assessing air quality impacts associated with current energy production activities as well as a future deployment of carbon capture and sequestration.

  5. Model analyses of atmospheric mercury: present air quality and effects of transpacific transport on the United States

    NASA Astrophysics Data System (ADS)

    Lei, H.; Liang, X.-Z.; Wuebbles, D. J.; Tao, Z.

    2013-11-01

    Atmospheric mercury is a toxic air and water pollutant that is of significant concern because of its effects on human health and ecosystems. A mechanistic representation of the atmospheric mercury cycle is developed for the state-of-the-art global climate-chemistry model, CAM-Chem (Community Atmospheric Model with Chemistry). The model simulates the emission, transport, transformation and deposition of atmospheric mercury (Hg) in three forms: elemental mercury (Hg(0)), reactive mercury (Hg(II)), and particulate mercury (PHg). Emissions of mercury include those from human, land, ocean, biomass burning and volcano related sources. Land emissions are calculated based on surface solar radiation flux and skin temperature. A simplified air-sea mercury exchange scheme is used to calculate emissions from the oceans. The chemistry mechanism includes the oxidation of Hg(0) in gaseous phase by ozone with temperature dependence, OH, H2O2 and chlorine. Aqueous chemistry includes both oxidation and reduction of Hg(0). Transport and deposition of mercury species are calculated through adapting the original formulations in CAM-Chem. The CAM-Chem model with mercury is driven by present meteorology to simulate the present mercury air quality during the 1999-2001 period. The resulting surface concentrations of total gaseous mercury (TGM) are then compared with the observations from worldwide sites. Simulated wet depositions of mercury over the continental United States are compared to the observations from 26 Mercury Deposition Network stations to test the wet deposition simulations. The evaluations of gaseous concentrations and wet deposition confirm a strong capability for the CAM-Chem mercury mechanism to simulate the atmospheric mercury cycle. The general reproduction of global TGM concentrations and the overestimation on South Africa indicate that model simulations of TGM are seriously affected by emissions. The comparison to wet deposition indicates that wet deposition patterns

  6. The Pathway for Oxygen: Tutorial Modelling on Oxygen Transport from Air to Mitochondrion: The Pathway for Oxygen.

    PubMed

    Bassingthwaighte, James B; Raymond, Gary M; Dash, Ranjan K; Beard, Daniel A; Nolan, Margaret

    2016-01-01

    The 'Pathway for Oxygen' is captured in a set of models describing quantitative relationships between fluxes and driving forces for the flux of oxygen from the external air source to the mitochondrial sink at cytochrome oxidase. The intervening processes involve convection, membrane permeation, diffusion of free and heme-bound O2 and enzymatic reactions. While this system's basic elements are simple: ventilation, alveolar gas exchange with blood, circulation of the blood, perfusion of an organ, uptake by tissue, and consumption by chemical reaction, integration of these pieces quickly becomes complex. This complexity led us to construct a tutorial on the ideas and principles; these first PathwayO2 models are simple but quantitative and cover: (1) a 'one-alveolus lung' with airway resistance, lung volume compliance, (2) bidirectional transport of solute gasses like O2 and CO2, (3) gas exchange between alveolar air and lung capillary blood, (4) gas solubility in blood, and circulation of blood through the capillary syncytium and back to the lung, and (5) blood-tissue gas exchange in capillaries. These open-source models are at Physiome.org and provide background for the many respiratory models there.

  7. Model analyses of atmospheric mercury: present air quality and effects of transpacific transport on the United States

    NASA Astrophysics Data System (ADS)

    Lei, H.; Liang, X.-Z.; Wuebbles, D. J.; Tao, Z.

    2013-04-01

    Atmospheric mercury is a toxic air and water pollutant that is of significant concern because of its effects on human health and ecosystems. A mechanistic representation of the atmospheric mercury cycle is developed for the state-of-the-art global climate-chemistry model, CAM-Chem (Community Atmospheric Model with Chemistry). The model simulates the emission, transport, transformation and deposition of atmospheric mercury (Hg) in three forms: elemental mercury (Hg(0)), reactive mercury (Hg(II)), and particulate mercury (PHg). Emissions of mercury include those from human, land, ocean, biomass burning and volcano related sources. Land emissions are calculated based on surface solar radiation flux and skin temperature. A simplified air-sea mercury exchange scheme is used to calculate emissions from the oceans. The chemistry mechanism includes the oxidation of Hg(0) in gaseous phase by ozone with temperature dependence, OH, H2O2 and chlorine. Aqueous chemistry includes both oxidation and reduction of Hg(0). Transport and deposition of mercury species are calculated through adapting the original formulations in CAM-Chem. The CAM-Chem model with mercury is driven by present meteorology to simulate the present mercury air quality during the 1999-2001 periods. The resulting surface concentrations of total gaseous mercury (TGM) are then compared with the observations from worldwide sites. Simulated wet depositions of mercury over the continental United States are compared to the observations from 26 Mercury Deposition Network stations to test the wet deposition simulations. The evaluations of gaseous concentrations and wet deposition confirm a strong capability for the CAM-Chem mercury mechanism to simulate the atmospheric mercury cycle. The results also indicate that mercury pollution in East Asia and Southern Africa is very significant with TGM concentrations above 3.0 ng m-3. The comparison to wet deposition indicates that wet deposition patterns of mercury are more

  8. Financing the Air Transportation Industry

    NASA Technical Reports Server (NTRS)

    Lloyd-Jones, D. J.

    1972-01-01

    The basic characteristics of the air transportation industry are outlined and it is shown how they affect financing requirements and patterns of production. The choice of financial timing is imperative in order to get the best interest rates available and to insure a fair return to investors. The fact that the industry cannot store its products has a fairly major effect on the amount of equipment to purchase, the amount of capital investment required, and the amount of return required to offset industry depriciation.

  9. Study of low density air transportation concepts

    NASA Technical Reports Server (NTRS)

    Webb, H. M.

    1972-01-01

    Low density air transport refers to air service to sparsely populated regions. There are two major objectives. The first is to examine those characteristics of sparsely populated areas which pertain to air transportation. This involves determination of geographical, commercial and population trends, as well as those traveler characteristics which affect the viability of air transport in the region. The second objective is to analyze the technical, economic and operational characteristics of low density air service. Two representative, but diverse arenas, West Virginia and Arizona, were selected for analysis: The results indicate that Arizona can support air service under certain assumptions whereas West Virginia cannot.

  10. The air transportation/energy system

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The changing pattern of transportation is discussed, and the energy intensiveness of various modes of transportation is also analyzed. Sociopsychological data affecting why people travel by air are presented, along with governmental regulation and air transportation economics. The aviation user tax structure is shown in tabular form.

  11. Air support facilities. [interface between air and surface transportation systems

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Airports are discussed in terms of the interface between the ground and air for transportation systems. The classification systems, design, facilities, administration, and operations of airports are described.

  12. A review of reaction rates and thermodynamic and transport properties for the 11-species air model for chemical and thermal nonequilibrium calculations to 30000 K

    NASA Technical Reports Server (NTRS)

    Gupta, Roop N.; Yos, Jerrold M.; Thompson, Richard A.

    1989-01-01

    Reaction rate coefficients and thermodynamic and transport properties are provided for the 11-species air model which can be used for analyzing flows in chemical and thermal nonequilibrium. Such flows will likely occur around currently planned and future hypersonic vehicles. Guidelines for determining the state of the surrounding environment are provided. Approximate and more exact formulas are provided for computing the properties of partially ionized air mixtures in such environments.

  13. Reducing Air Pollution from International Transportation

    EPA Pesticide Factsheets

    Because of their reliance on petroleum-based fuels and their dramatic growth rates in recent decades, air and sea transport are responsible for significant emissions of both traditional air pollutants and greenhouse gases.

  14. Representing the Effects of Long-Range Transport and Lateral Boundary Conditions in Regional Air Pollution Models

    EPA Science Inventory

    The Community Multiscale Air Quality (CMAQ) modeling system was applied to a domain covering the northern hemisphere; meteorological information was derived from the Weather Research and Forecasting (WRF) model run on identical grid and projection configuration, while the emissio...

  15. Modeling of Trans-boundary Transport of Air Pollutants in the California-Mexico Border Region during Cal-Mex 2010

    NASA Astrophysics Data System (ADS)

    Bei, N.; Zavala, M. A.; Lei, W.; Li, G.; Molina, L. T.

    2010-12-01

    The US and Mexico share a common air basin along the ~200 km border between California and Baja California. The economical activities in this region are heavily influenced by the international trade and commerce between Mexico and the US that mainly occurs through the borders of the sister cities of San Diego-Tijuana and Calexico-Mexicali. The diversity and differences in the characteristics of emissions sources of air pollutants in the California-Mexico border region make this an important area for the study of the chemistry and trans-boundary transport of air pollutants. During May-June of 2010, the Cal-Mex 2010 field campaign included a series of measurements aimed at characterizing the emissions from major sources in the California-Mexico border region and assessing the possible impacts of these emissions on local and regional air quality. In this work we will present the results of the use of the Comprehensive Air quality model with extensions (CAMx) in a modeling domain that includes the sister cities of San Diego-Tijuana and Calexico-Mexicali for studying events of trans-boundary transport of air pollutants during Cal-Mex 2010. The measurements obtained during the Cal-Mex 2010 field campaign are used in the evaluation of the model performance and in the design of air quality improvement policies in the California-Mexico border region.

  16. Air ambulance medical transport advertising and marketing.

    PubMed

    2011-01-01

    The National Association of EMS Physicians (NAEMSP), the American College of Emergency Physicians (ACEP), the Air Medical Physician Association (AMPA), the Association of Air Medical Services (AAMS), and the National Association of State EMS Officials (NASEMSO) believe that patient care and outcomes are optimized by using air medical transport services that are licensed air ambulance providers with robust physician medical director oversight and ongoing quality assessment and review. Only air ambulance medical transport services with these credentials should advertise/market themselves as air ambulance services.

  17. PAT-2 (Plutonium Air-Transportable Model 2) safety analysis report

    SciTech Connect

    Andersen, J.A.; Davis, E.J.; Duffey, T.A.; Dupree, S.A.; George, O.L. Jr.; Ortiz, Z.

    1981-07-01

    The PAT-2 package is designed for the safe transport of plutonium and/or uranium in small quantities. The PAT-2 package is resistant to severe accidents, including that of a high-speed jet aircraft crash, and is designed to withstand such environments as extreme impact, crushing, puncturing and slashing loads, severe hydrocarbon-fueled fires, and deep underwater immersion, with no escape of contents. The package meets the requirements of 10 CFR 71 for Fissile Class I packages with a cargo of 15 grams of Pu-239, or other isotopic forms described herein, not to exceed 2 watts of thermal activity. This SAR presents design and oprational information including evaluations and analyses, test results, operating procedures, maintenance, and quality assurance information.

  18. MODELING TRANSPORT AND TRANSFORMATION OF HG COMPOUNDS IN CONTINENTAL AIR MASSES

    EPA Science Inventory

    The global mercury cycle involves both continental and marine environments. However, there are special considerations for modeling atmospheric mercury over continents. Most anthropogenic sources of atmospheric mercury are on continents and they emit a large fraction in oxidized ...

  19. Compressed Air/Vacuum Transportation Techniques

    NASA Astrophysics Data System (ADS)

    Guha, Shyamal

    2011-03-01

    General theory of compressed air/vacuum transportation will be presented. In this transportation, a vehicle (such as an automobile or a rail car) is powered either by compressed air or by air at near vacuum pressure. Four version of such transportation is feasible. In all versions, a ``c-shaped'' plastic or ceramic pipe lies buried a few inches under the ground surface. This pipe carries compressed air or air at near vacuum pressure. In type I transportation, a vehicle draws compressed air (or vacuum) from this buried pipe. Using turbine or reciprocating air cylinder, mechanical power is generated from compressed air (or from vacuum). This mechanical power transferred to the wheels of an automobile (or a rail car) drives the vehicle. In type II-IV transportation techniques, a horizontal force is generated inside the plastic (or ceramic) pipe. A set of vertical and horizontal steel bars is used to transmit this force to the automobile on the road (or to a rail car on rail track). The proposed transportation system has following merits: virtually accident free; highly energy efficient; pollution free and it will not contribute to carbon dioxide emission. Some developmental work on this transportation will be needed before it can be used by the traveling public. The entire transportation system could be computer controlled.

  20. Mathematically modeling the transport of hazardous air pollutants from multiple sources

    SciTech Connect

    Lin, J.S.; Hildemann, L.M.

    1995-11-01

    Analytical solutions of the atmospheric diffusion equation with wind speed and eddy diffusivities expressed as power functions of height have been restricted to total reflection at the boundaries (Neumann-type boundary conditions), and limited to a single isolated point source located at the origin. In reality, however, due to partial adsorption or deposition at the earth`s surface, the actual concentrations of airborne pollutants near groundlevel most often fall between Dirichlet (total adsorption) and Neumann boundary types. In addition, multiple-source dispersion modeling is still done almost exclusively using the Gaussian plume model. It is therefore the purpose of this publication to systematically study the solutions of the atmospheric diffusion equation for several boundary condition types, and to apply the Green`s function concept to the multiple-source problem, where the sources can be located anywhere in the region of interest.

  1. Studies in the demand for short haul air transportation

    NASA Technical Reports Server (NTRS)

    Kanafani, A.; Gosling, G.; Taghavi, S.

    1975-01-01

    Demand is analyzed in a short haul air transportation corridor. Emphasis is placed on traveler selection from available routes. Model formulations, estimation techniques, and traffic data handling are included.

  2. Air medical transportation in India: Our experience

    PubMed Central

    Khurana, Himanshu; Mehta, Yatin; Dubey, Sunil

    2016-01-01

    Background and Aims: Long distance air travel for medical needs is on the increase worldwide. The condition of some patients necessitates specially modified aircraft, and monitoring and interventions during transport by trained medical personnel. This article presents our experience in domestic and international interhospital air medical transportation from January 2010 to January 2014. Material and Methods: Hospital records of all air medical transportation undertaken to the institute during the period were analyzed for demographics, primary etiology, and events during transport. Results: 586 patients, 453 (77.3%) males and 133 (22.6%) females of ages 46.7 ± 12.6 years and 53.4 ± 9.7 years were transported by us to the institute. It took 3030 flying hours with an average of 474 ± 72 min for each mission. The most common indication for transport was cardiovascular diseases in 210 (35.8%) and central nervous system disease in 120 (20.4%) cases. The overall complication rate was 5.3% There was no transport related mortality. Conclusion: Cardiac and central nervous system ailments are the most common indication for air medical transportation. These patients may need attention and interventions as any critical patient in the hospital but in a difficult environment lacking space and help. Air medical transport carries no more risk than ground transportation. PMID:27625486

  3. Fate and Transport Modeling of Selected Chlorinated Organic Compounds at Hangar 1000, U.S. Naval Air Station, Jacksonville, Florida

    USGS Publications Warehouse

    Davis, J. Hal

    2003-01-01

    The Jacksonville Naval Air Station occupies 3,800 acres adjacent to the St. Johns River in Jacksonville, Florida. Two underground storage tanks at Hangar 1000 contained solvents from the late 1960s until they were removed in 1994. Ground-water samples at one of the tank sites had levels of trichloroethene (TCE) and total dichloroethene (DCE) of 8,710 micrograms per liter (mg/L) and 4,280 mg/L, respectively. Vinyl chloride (VC) at the site is the result of the biodegradation of DCE. Ground water beneath Hangar 1000 flows toward a storm sewer. TCE and DCE plumes travel with the ground water and presumably have reached the storm sewer, which discharges to the St. Johns River. Simulation of solute transport indicates that the traveltime from the storage tank site to the storm sewer is 16, 14, and 12 years for TCE, DCE, and VC respectively. TCE has the longest traveltime because it has the highest retardation factor at 2.5, DCE takes less time with a retardation factor of 2.0, and VC has the quickest traveltime because it has the lowest retardation factor of 1.7. Based on modeling results, the release of contaminants in the aquifer occurred more than 16 years ago. Model-derived dispersivity values at Hangar 1000 were: longitudinal 1.5 feet (ft), transverse 0.27 ft, and vertical 0.27 ft. The model-derived first order decay rates for biodegradation of TCE, DCE, and VC were 0.0002 per day (d-1), 0.0002 d-1, and 0.06 d-1, respectively. These rates are equivalent to half-lives of 13.7 years for TCE and DCE and 17 days for VC. Source area reductions in contaminant concentrations of 50 and 100 percent were modeled to simulate remediation. As expected, reducing the source concentration by 50 percent resulted in eventual TCE, DCE, and VC concentrations that were half of the original concentrations. About 16 years were needed for new steady-state TCE concentrations to develop, about 14 years for DCE, and about 12 years for VC. Reducing the source area concentrations by 100

  4. Statewide air medical transports for Massachusetts.

    PubMed

    Garthe, Elizabeth; Mango, Nicholas K; Prenney, Brad

    2002-01-01

    In 1997, the Massachusetts Department of Public Health (MDPH) established a process to centralize air medical transport information. This database is one of the first statewide, population-based sources for civilian rotary-wing air medical transports (U.S. Coast Guard, police, and military missions are not included). The purpose of this database is to facilitate MDPH review of air medical transport service utilization, with input from a multidisciplinary committee. This article discusses the challenges in producing uniform data from multiple service submissions and presents aggregate "baseline" utilization information for 1996. These data served as a starting point for later studies using data linkage. This indexed article is the first to report statewide, population-based data for all types of air medical helicopter transports. The only other indexed "statewide air medical transport" paper focused on scene transports to trauma centers in Pennsylvania. A previous article by the authors in the July-September 2000 Air Medical Journal provided an overview of air medical transports for fatal motor vehicle crashes for 1 region of the state.

  5. User Guide for Air Force Base Automotive Transportation Simulation Model -BATS. Volume I. Data Collection and Reduction.

    DTIC Science & Technology

    1979-09-01

    Engineer Chief, Assessment Technology & Energy Br EMIL C. FREIN , Maj, USAF 6 iOSEPH S. PIZZUTO, Col, USAF, BSC Chief, Environics Division Commander... community near an air base proposed routing some buses to the base and wished to predict the change in air pollution and in peak hour congestion due...operating 2 than without. The civilian community might further use the models to evaluate the cost effectiveness of the proposed bus service as compared to

  6. Modelling the Contribution of Long-range Transport of Ammonium Nitrates to Urban Air Pollution and Human Exposure in the United Kingdom

    NASA Astrophysics Data System (ADS)

    Reis, S.; Vieno, M.; Beck, R.; Ots, R.; Moring, A.; Steinle, S.; Heal, M. R.; Doherty, R. M.

    2014-12-01

    Urban air pollution and its effects on human health remain to be a challenge in spite of substantial reductions in the emissions of air pollutants (e.g. sulphur dioxide, nitrogen oxides) over the past decades in Europe. While primary pollutants play a vital role in urban air pollution, recent model studies highlight and quantify the relevance of long-range transport of secondary pollution (e.g. secondary inorganic aerosols such as ammonium sulphates and nitrates, or ground level ozone) for the exceedance of local air quality limit values in urban areas across Europe. This contribution can be seen in recurring episodes, for instance in spring 2014, with very high levels of fine particulate matter (PM2.5) in Paris, London and other European cities, as well as in elevated background levels throughout the year. While we will focus on the contribution to exceedances of PM2.5 limit values here, this transboundary transport has wider implications for the deposition of reactive nitrogen far from the source as well. As local authorities are tasked with ensuring the attainment of air quality limit values, exceedances caused by long-range transport, with emissions originating from sources outside of their jurisdiction present substantial challenges. Furthermore, while policy measures have successfully addressed emissions from large point sources in the past, and made progress towards reducing pollution from road vehicles, emissions of ammonia from agricultural sources - a key component for the long-range transport of secondary inorganic aerosols - have remained relatively stable in Europe. Using the example of Europe and the UK, we demonstrate in our presentation how atmospheric chemistry transport modelling across different scales (from regional to local) can provide vital insight in the mechanisms of and relative contributions to the formation of secondary inorganic aerosols. In addition, we illustrate how this modelling capability can inform the design of efficient control

  7. A review of reaction rates and thermodynamic and transport properties for an 11-species air model for chemical and thermal nonequilibrium calculations to 30000 K

    NASA Technical Reports Server (NTRS)

    Gupta, Roop N.; Yos, Jerrold M.; Thompson, Richard A.; Lee, Kam-Pui

    1990-01-01

    Reaction rate coefficients and thermodynamic and transport properties are reviewed and supplemented for the 11-species air model which can be used for analyzing flows in chemical and thermal nonequilibrium up to temperatures of 3000 K. Such flows will likely occur around currently planned and future hypersonic vehicles. Guidelines for determining the state of the surrounding environment are provided. Curve fits are given for the various species properties for their efficient computation in flowfield codes. Approximate and more exact formulas are provided for computing the properties of partially ionized air mixtures in a high energy environment. Limitations of the approximate mixing laws are discussed for a mixture of ionized species. An electron number-density correction for the transport properties of the charged species is obtained. This correction has been generally ignored in the literature.

  8. Simulating smoke transport from wildland fires with a regional-scale air quality model: sensitivity to spatiotemporal allocation of fire emissions.

    PubMed

    Garcia-Menendez, Fernando; Hu, Yongtao; Odman, Mehmet T

    2014-09-15

    Air quality forecasts generated with chemical transport models can provide valuable information about the potential impacts of fires on pollutant levels. However, significant uncertainties are associated with fire-related emission estimates as well as their distribution on gridded modeling domains. In this study, we explore the sensitivity of fine particulate matter concentrations predicted by a regional-scale air quality model to the spatial and temporal allocation of fire emissions. The assessment was completed by simulating a fire-related smoke episode in which air quality throughout the Atlanta metropolitan area was affected on February 28, 2007. Sensitivity analyses were carried out to evaluate the significance of emission distribution among the model's vertical layers, along the horizontal plane, and into hourly inputs. Predicted PM2.5 concentrations were highly sensitive to emission injection altitude relative to planetary boundary layer height. Simulations were also responsive to the horizontal allocation of fire emissions and their distribution into single or multiple grid cells. Additionally, modeled concentrations were greatly sensitive to the temporal distribution of fire-related emissions. The analyses demonstrate that, in addition to adequate estimates of emitted mass, successfully modeling the impacts of fires on air quality depends on an accurate spatiotemporal allocation of emissions.

  9. A compartment model of alveolar-capillary oxygen diffusion with ventilation-perfusion gradient and dynamics of air transport through the respiratory tract.

    PubMed

    Jaworski, Jacek; Redlarski, Grzegorz

    2014-08-01

    This paper presents a model of alveolar-capillary oxygen diffusion with dynamics of air transport through the respiratory tract. For this purpose electrical model representing the respiratory tract mechanics and differential equations representing oxygen membrane diffusion are combined. Relevant thermodynamic relations describing the mass of oxygen transported into the human body are proposed as the connection between these models, as well as the influence of ventilation-perfusion mismatch on the oxygen diffusion. The model is verified based on simulation results of varying exercise intensities and statistical calculations of the results obtained during various clinical trials. The benefit of the approach proposed is its application in simulation-based research aimed to generate quantitative data of normal and pathological conditions. Based on the model presented, taking into account many essential physiological processes and air transport dynamics, comprehensive and combined studies of the respiratory efficiency can be performed. The impact of physical exercise, precise changes in respiratory tract mechanics and alterations in breathing pattern can be analyzed together with the impact of various changes in alveolar-capillary oxygen diffusion. This may be useful in simulation of effects of many severe medical conditions and increased activity level.

  10. Modelling Hot Air Balloons.

    ERIC Educational Resources Information Center

    Brimicombe, M. W.

    1991-01-01

    A macroscopic way of modeling hot air balloons using a Newtonian approach is presented. Misleading examples using a car tire and the concept of hot air rising are discussed. Pressure gradient changes in the atmosphere are used to explain how hot air balloons work. (KR)

  11. MODELING THE TRANSPORT AND CHEMICAL EVOLUTION OF ONSHORE AND OFFSHORE EMISSIONS AND THEIR IMPACT ON LOCAL AND REGIONAL AIR QUALITY USING A VARIABLE-GRID-RESOLUTION AIR QUALITY MODEL

    SciTech Connect

    Kiran Alapaty

    2005-05-13

    This second annual report summarizes the research performed from 17 April 2004 through 16 April 2005. Major portions of the research in several of the project's current eight tasks have been completed. We have successfully developed the meteorological inputs using the best possible modeling configurations, resulting in improved representation of atmospheric processes. The development of the variable-grid-resolution emissions model, SMOKE-VGR, is also completed. The development of the MAQSIP-VGR has been completed and a test run was performed to ensure the functionality of this air quality model. Thus, the project is on schedule as planned. During the upcoming reporting period, we expect to perform the first MAQSIP-VGR simulations over the Houston-Galveston region to study the roles of the meteorology, offshore emissions, and chemistry-transport interactions that determine the temporal and spatial evolution of ozone and its precursors.

  12. Three-dimensional Simulations of the Mean Air Transport During the 1997 Forest Fires in Kalimantan, Indonesia Using a Mesoscale Numerical Model

    NASA Astrophysics Data System (ADS)

    Roswintiarti, O.; Raman, S.

    - This paper describes the meteorological processes responsible for the mean transport of air pollutants during the ENSO-related forest fires in Kalimantan, Indonesia from 00 UTC 21 September to 00 UTC 25 September, 1997. The Fifth Generation of the Pennsylvania State University-National Center for Atmospheric Research (PSU-NCAR) Mesoscale Model (MM5) is used to simulate three-dimensional winds at 6-hourly intervals. A nonhydrostatic version of the model is run using two nested grids with horizontal resolutions of 45 km and 15 km. From the simulated wind fields, the backward and forward trajectories of the air parcel are investigated using the Vis5D model.The results indicate that the large-scale subsidence over Indonesia, the southwest monsoon low-level flows (2-8 m s-1), and the shallow planetary boundary layer height (400-800 m) play a key role in the transport of air pollutants from Kalimantan to Malaysia, Singapore and Brunei.

  13. Coupled modeling of water transport and air-droplet interaction in the electrode of a proton exchange membrane fuel cell

    NASA Astrophysics Data System (ADS)

    Esposito, Angelo; Pianese, Cesare; Guezennec, Yann G.

    In this work, an accurate and computationally fast model for liquid water transport within a proton exchange membrane fuel cell (PEMFC) electrode is developed by lumping the space-dependence of the relevant variables. Capillarity is considered as the main transport mechanism within the gas diffusion layer (GDL). The novelty of the model lies in the coupled simulation of the water transport at the interface between gas diffusion layer and gas flow channel (GFC). This is achieved with a phenomenological description of the process that allows its simulation with relative simplicity. Moreover, a detailed two-dimensional visualization of such interface is achieved via geometric simulation of water droplets formation, growth, coalescence and detachment on the surface of the GDL. The model is useful for optimization analysis oriented to both PEMFC design and balance of plant. Furthermore, the accomplishment of reduced computational time and good accuracy makes the model suitable for control strategy implementation to ensure PEM fuel cells operation within optimal electrode water content.

  14. Modeling the Transport and Chemical Evolution of Onshore and Offshore Emissions and their Impact on Local and Regional Air Quality Using a Variable-Grid-Resolution Air Quality Model

    SciTech Connect

    Kiran Alapaty

    2006-04-16

    This Annual report summarizes the research performed from 17 April 2005 through 16 April 2006. Major portions of the research in several of the project's current eight tasks have been completed. We have successfully developed the meteorological inputs using the best possible modeling configurations, resulting in improved representation of atmospheric processes. The development of the variable-grid-resolution emissions model, SMOKE-VGR, is also completed. The development of the MAQSIP-VGR has been completed and a test run was performed to ensure the functionality of this air quality model. We have incorporated new emission data base to update the offshore emissions. However, we have faced some bottleneck problems in the testing the integrity of the new database. For this reason, we have asked for a no cost extension of this project to tackle these scientific problems. Thus, the project is on a one-year delay schedule. During the reporting period, we solved all problems related to the new emission database. We are ready to move to developing the final product, implementation and testing of the variable grid technology into the Community Multiscale Air Quality Model (CMAQ) to develop the CMAQ-VGR. During the upcoming months we will perform the first CMAQ-VGR simulations over the Houston-Galveston region to study the roles of the meteorology, offshore emissions, and chemistry-transport interactions that determine the temporal and spatial evolution of ozone and its precursors.

  15. Air transport of plutonium metal: content expansion initiative for the plutonium air transportable (PAT01) packaging

    SciTech Connect

    Caviness, Michael L; Mann, Paul T

    2010-01-01

    The National Nuclear Security Administration (NNSA) has submitted an application to the Nuclear Regulatory Commission (NRC) for the air shipment of plutonium metal within the Plutonium Air Transportable (PAT-1) packaging. The PAT-1 packaging is currently authorized for the air transport of plutonium oxide in solid form only. The INMM presentation will provide a limited overview of the scope of the plutonium metal initiative and provide a status of the NNSA application to the NRC.

  16. A Global Airport-Based Risk Model for the Spread of Dengue Infection via the Air Transport Network

    PubMed Central

    Gardner, Lauren; Sarkar, Sahotra

    2013-01-01

    The number of travel-acquired dengue infections has seen a consistent global rise over the past decade. An increased volume of international passenger air traffic originating from regions with endemic dengue has contributed to a rise in the number of dengue cases in both areas of endemicity and elsewhere. This paper reports results from a network-based risk assessment model which uses international passenger travel volumes, travel routes, travel distances, regional populations, and predictive species distribution models (for the two vector species, Aedes aegypti and Aedes albopictus) to quantify the relative risk posed by each airport in importing passengers with travel-acquired dengue infections. Two risk attributes are evaluated: (i) the risk posed by through traffic at each stopover airport and (ii) the risk posed by incoming travelers to each destination airport. The model results prioritize optimal locations (i.e., airports) for targeted dengue surveillance. The model is easily extendible to other vector-borne diseases. PMID:24009672

  17. [Air transport, aeronautic medicine, health].

    PubMed

    Cupa, Michel

    2009-10-01

    There were 3.2 billion airline passengers in 2006, compared to only 30 million in 1950. Intercontinental health disparities create a risk of pandemics such as SARS and so-called bird flu. Precautions are now being implemented both in airports and in aircraft, in addition to measures intended to prevent the spread of malaria and arboviral diseases, such as vector eradication, elimination of stagnant water, malaria prophylaxis, vaccination, and use of repellents. These measures are dealt with in international health regulations, which have existed since 1851 and were last updated on 15 June 2007. Flying on an airliner also carries a risk of hypobaria (cabin pressure at 2000 m), which can aggravate respiratory problems. Other problems include relative hypoxia, gas expansion, air dryness, ozone, cosmic rays, airsickness, jet lag, the effects of alcohol and tobacco, and, more recently, deep vein thrombosis (DVT) and pulmonary embolism (PE), collectively known as "coach class syndrome". A new type of medicine has appeared, in the form of on-board medical assistance. The European Civil Aviation Committee has recommended first-aid training for cabin crews and onboard medical equipment such as first-aid kits and defibrillators. Airline statistics show that one in-flight medical incident occurs per 20 000 passengers, as well as one death per 5 million passengers and one medical reroute per 20 000 flights (40% of reroutes turn out to be unjustified). More than 80% of long-haul flights have a physician travelling on board. However, depending on his or her specialty, problems of competence and legal responsibility may arise. Ground-based medical centers can provide help via satellite telephone, but this implies the need for airline staff training. International cooperation is the only way to minimize the health risks associated with the growth in global air travel.

  18. Comparing three vegetation monoterpene emission models to measured gas concentrations with a model of meteorology, air chemistry and chemical transport

    SciTech Connect

    Smolander, S.; He, Q.; Mogensen, Ditte; Zhou, L.; Back, J.; Ruuskanen, T.; Noe, S.; Guenther, Alex B.; Aaltonen, H.; Kulmala, M.; Boy, Michael

    2014-10-07

    Biogenic volatile organic compounds (BVOCs) are essential in atmospheric chemistry because of their chemical reactions that produce and destroy tropospheric ozone, their effects on aerosol formation and growth, and their potential influence on global warming. As one of the important BVOC groups, monoterpenes have been a focus of scientific attention in atmospheric research. Detailed regional measurements and model estimates are needed to study emission potential and the monoterpene budget on a global scale. Since the use of empirical measurements for upscaling is limited by many physical and biological factors such as genetic variation, temperature and light, water availability, seasonal changes, and environmental stresses, comprehensive inventories over larger areas are difficult to obtain.

  19. Formal Methods Applications in Air Transportation

    NASA Technical Reports Server (NTRS)

    Farley, Todd

    2009-01-01

    The U.S. air transportation system is the most productive in the world, moving far more people and goods than any other. It is also the safest system in the world, thanks in part to its venerable air traffic control system. But as demand for air travel continues to grow, the air traffic control system s aging infrastructure and labor-intensive procedures are impinging on its ability to keep pace with demand. And that impinges on the growth of our economy. Air traffic control modernization has long held the promise of a more efficient air transportation system. Part of NASA s current mission is to develop advanced automation and operational concepts that will expand the capacity of our national airspace system while still maintaining its excellent record for safety. It is a challenging mission, as efforts to modernize have, for decades, been hamstrung by the inability to assure safety to the satisfaction of system operators, system regulators, and/or the traveling public. In this talk, we ll provide a brief history of air traffic control, focusing on the tension between efficiency and safety assurance, and the promise of formal methods going forward.

  20. UZ Colloid Transport Model

    SciTech Connect

    M. McGraw

    2000-04-13

    The UZ Colloid Transport model development plan states that the objective of this Analysis/Model Report (AMR) is to document the development of a model for simulating unsaturated colloid transport. This objective includes the following: (1) use of a process level model to evaluate the potential mechanisms for colloid transport at Yucca Mountain; (2) Provide ranges of parameters for significant colloid transport processes to Performance Assessment (PA) for the unsaturated zone (UZ); (3) Provide a basis for development of an abstracted model for use in PA calculations.

  1. Environmental injustices of children's exposure to air pollution from road-transport within the model British multicultural city of Leicester: 2000-09.

    PubMed

    Jephcote, Calvin; Chen, Haibo

    2012-01-01

    The significant contribution of road-transport to air pollution within the urban arena is widely acknowledged, and traditionally explored in relation to health outcomes across a temporal scale. However, the structure of the urban environment is also of importance in dictating the existence of extremely variable traffic pollutant levels, which often tend to be linked with social disparities. Nevertheless 'Environmental Justice' studies have rarely tackled the adverse health implications of exposures from mobile sources (Chakraborty, 2009), or have applied statistical techniques that are appropriate for such spatial data (Gilbert and Chakraborty, 2011). This article addresses these gaps by spatially examining the distribution of respiratory hospitalisation incidents of children aged 0-15 years in relation to social circumstances and residential exposures of annual PM(10) road-transport emissions within Leicester during 2000-09. Continuing upon the theme of 'Environmental Justice', the research explores the intra-urban spatial distribution of those who produce and residentially experience the majority of road-transport emissions. The findings indicate significant global relationships to exist between children's hospitalisation rates and social-economic-status, ethnic minorities, and PM(10) road-transport emissions within Leicester. Local Indicators of Spatial Association (LISA) and Geographically Weighted Regression (GWR) identified important localised variations within the dataset, specifically relating to a double-burden of residentially experienced road-transport emissions and deprivation effecting inner city children's respiratory health. Furthermore, affluent intra-urban communities tended to contribute the highest levels of emission from private transport, while residentially experiencing relatively low exposure of transport emissions. This would suggest that environmental injustices prevail across the model British multicultural city of Leicester.

  2. Using High and Low Resolution Profiles of CO2 and CH4 Measured with AirCores to Evaluate Transport Models and Atmospheric Columns Retrieved from Space

    NASA Astrophysics Data System (ADS)

    Membrive, O.; Crevoisier, C. D.; Sweeney, C.; Hertzog, A.; Danis, F.; Picon, L.; Engel, A.; Boenisch, H.; Durry, G.; Amarouche, N.

    2015-12-01

    Over the past decades many methods have been developed to monitor the evolution of greenhouse gases (GHG): ground networks (NOAA, ICOS, TCCON), aircraft campaigns (HIPPO, CARIBIC, Contrail…), satellite observations (GOSAT, IASI, AIRS…). Nevertheless, precise and regular vertical profile measurements are currently still missing from the observing system. To address this need, an original and innovative atmospheric sampling system called AirCore has been developed at NOAA (Karion et al. 2010). This new system allows balloon measurements of GHG vertical profiles from the surface up to 30 km. New versions of this instrument have been developed at LMD: a high-resolution version "AirCore-HR" that differs from other AirCores by its high vertical resolution and two "light" versions (lower resolution) aiming to be flown under meteorological balloon. LMD AirCores were flown on multi-instrument gondolas along with other independent instruments measuring CO2 and CH4 in-situ during the Strato Science balloon campaigns operated by the French space agency CNES in collaboration with the Canadian Space Agency in Timmins (Ontario, Canada) in August 2014 and 2015. First, we will present comparisons of the vertical profiles retrieved with various AirCores (LMD and Frankfurt University) to illustrate repeatability and impact of the vertical resolution as well as comparisons with independent in-situ measurements from other instruments (laser diode based Pico-SDLA). Second, we will illustrate the usefulness of AirCore measurements in the upper troposphere and stratosphere for validating and interpreting vertical profiles from atmospheric transport models as well as observations of total and partial column of methane and carbon dioxide from several current and future spaceborne missions such as: ACE-FTS, IASI and GOSAT.

  3. CMAQ Involvement in Air Quality Model Evaluation International Initiative

    EPA Pesticide Factsheets

    Description of Air Quality Model Evaluation International Initiative (AQMEII). Different chemical transport models are applied by different groups over North America and Europe and evaluated against observations.

  4. Green Propulsion Technologies for Advanced Air Transports

    NASA Technical Reports Server (NTRS)

    Del Rosario, Ruben

    2015-01-01

    Air transportation is critical to U.S. and Global economic vitality. However, energy and climate issues challenge aviations ability to be sustainable in the long term. Aviation must dramatically reduce fuel use and related emissions. Energy costs to U.S. airlines nearly tripled between 1995 and 2011, and continue to be the highest percentage of operating costs. The NASA Advanced Air Transports Technology Project addresses the comprehensive challenge of enabling revolutionary energy efficiency improvements in subsonic transport aircraft combined with dramatic reductions in harmful emissions and perceived noise to facilitate sustained growth of the air transportation system. Advanced technologies and the development of unconventional aircraft systems offer the potential to achieve these improvements. The presentation will highlight the NASA vision of revolutionary systems and propulsion technologies needed to achieve these challenging goals. Specifically, the primary focus is on the N+3 generation; that is, vehicles that are three generations beyond the current state of the art, requiring mature technology solutions in the 2025-30 timeframe, which are envisioned as being powered by Hybrid Electric Propulsion Systems.

  5. Green Propulsion Technologies for Advanced Air Transports

    NASA Technical Reports Server (NTRS)

    Del Rosario, Ruben

    2015-01-01

    Air transportation is critical to U.S. and Global economic vitality. However, energy and climate issues challenge aviation's ability to be sustainable in the long term. Aviation must dramatically reduce fuel use and related emissions. Energy costs to U.S. airlines nearly tripled between 1995 and 2011, and continue to be the highest percentage of operating costs. The NASA Advanced Air Transports Technology Project addresses the comprehensive challenge of enabling revolutionary energy efficiency improvements in subsonic transport aircraft combined with dramatic reductions in harmful emissions and perceived noise to facilitate sustained growth of the air transportation system. Advanced technologies and the development of unconventional aircraft systems offer the potential to achieve these improvements. The presentation will highlight the NASA vision of revolutionary systems and propulsion technologies needed to achieve these challenging goals. Specifically, the primary focus is on the N+3 generation; that is, vehicles that are three generations beyond the current state of the art, requiring mature technology solutions in the 2025-30 timeframe.

  6. Modeling the Emission, Transport, and Dispersion of Post-wildfire Dust from Western Sagebrush Landscapes within a Regional Air Quality Framework

    NASA Astrophysics Data System (ADS)

    Chung, S. H.; Wagenbrenner, N. S.; Lamb, B. K.

    2014-12-01

    Millions of hectares are burned by wildfires each year in the western US. The resulting burn scars are extremely wind erodible surfaces with high loadings of easily entrained ash and soil. Previous work has demonstrated that wind erosion from these burn scars can release large amounts of dust and ash as particulate matter (PM) into the atmosphere, resulting in large impacts on downwind air quality and visibility. Sagebrush-dominated landscapes, where often essentially all vegetation is consumed by the fire, appear to be particularly vulnerable. Climate change predictions indicate more wildfire activity in the western US and, hence, more potential for wind erosion from burn scars. However, these PM sources are not yet accounted for in regional air quality models. Here we describe a modification to the AIRPACT regional air quality modeling framework for simulating the emission, transport and dispersion of PM from post-wildfire burn scars. We present results from a 2012 sagebrush fire in southeast Oregon as a case study. Modeled PM emission rates and downwind concentrations are compared against observations for two major dust events, one which resulted in exceedances of the PM10 National Ambient Air Quality Standard in Boise, Idaho the month after the fire and another which resulted in a significant dust on snow event and subsequent snowmelt in the Owyhee Mountains of southwest Idaho the following spring. Additionally, we present model estimates of annual emissions from all wildfires that occurred in sagebrush landscapes of the western US during the 2012 fire year as an estimate of annual post-fire PM loading potential.

  7. A high-fidelity multiphysics model for the new solid oxide iron-air redox battery. part I: Bridging mass transport and charge transfer with redox cycle kinetics

    NASA Astrophysics Data System (ADS)

    Jin, Xinfang; Zhao, Xuan; Huang, Kevin

    2015-04-01

    A high-fidelity two-dimensional axial symmetrical multi-physics model is described in this paper as an effort to simulate the cycle performance of a recently discovered solid oxide metal-air redox battery (SOMARB). The model collectively considers mass transport, charge transfer and chemical redox cycle kinetics occurring across the components of the battery, and is validated by experimental data obtained from independent research. In particular, the redox kinetics at the energy storage unit is well represented by Johnson-Mehl-Avrami-Kolmogorov (JMAK) and Shrinking Core models. The results explicitly show that the reduction of Fe3O4 during the charging cycle limits the overall performance. Distributions of electrode potential, overpotential, Nernst potential, and H2/H2O-concentration across various components of the battery are also systematically investigated.

  8. A high-fidelity multiphysics model for the new solid oxide iron-air redox battery part I: Bridging mass transport and charge transfer with redox cycle kinetics

    SciTech Connect

    Jin, XF; Zhao, X; Huang, K

    2015-04-15

    A high-fidelity two-dimensional axial symmetrical multi-physics model is described in this paper as an effort to simulate the cycle performance of a recently discovered solid oxide metal-air redox battery (SOMARB). The model collectively considers mass transport, charge transfer and chemical redox cycle kinetics occurring across the components of the battery, and is validated by experimental data obtained from independent research. In particular, the redox kinetics at the energy storage unit is well represented by Johnson-Mehl-Avrami-Kolmogorov (JIVIAK) and Shrinking Core models. The results explicitly show that the reduction of Fe3O4 during the charging cycle limits the overall performance. Distributions of electrode potential, overpotential, Nernst potential, and H-2/H2O-concentration across various components of the battery are also systematically investigated. (C) 2015 Elsevier B.V. All rights reserved.

  9. Opportunities to Improve Air Quality through Transportation Pricing Programs

    EPA Pesticide Factsheets

    This document is intended to give state and local air quality and transportation planners,elected government officials, and other interested parties background information on transportation pricing programs.

  10. Transformations in Air Transportation Systems For the 21st Century

    NASA Technical Reports Server (NTRS)

    Holmes, Bruce J.

    2004-01-01

    Globally, our transportation systems face increasingly discomforting realities: certain of the legacy air and ground infrastructures of the 20th century will not satisfy our 21st century mobility needs. The consequence of inaction is diminished quality of life and economic opportunity for those nations unable to transform from the 20th to 21st century systems. Clearly, new thinking is required regarding business models that cater to consumers value of time, airspace architectures that enable those new business models, and technology strategies for innovating at the system-of-networks level. This lecture proposes a structured way of thinking about transformation from the legacy systems of the 20th century toward new systems for the 21st century. The comparison and contrast between the legacy systems of the 20th century and the transformed systems of the 21st century provides insights into the structure of transformation of air transportation. Where the legacy systems tend to be analog (versus digital), centralized (versus distributed), and scheduled (versus on-demand) for example, transformed 21st century systems become capable of scalability through technological, business, and policy innovations. Where air mobility in our legacy systems of the 20th century brought economic opportunity and quality of life to large service markets, transformed air mobility of the 21st century becomes more equitable available to ever-thinner and widely distributed populations. Several technological developments in the traditional aircraft disciplines as well as in communication, navigation, surveillance and information systems create new foundations for 21st thinking about air transportation. One of the technological developments of importance arises from complexity science and modern network theory. Scale-free (i.e., scalable) networks represent a promising concept space for modeling airspace system architectures, and for assessing network performance in terms of robustness

  11. Air Cargo Transportation Route Choice Analysis

    NASA Technical Reports Server (NTRS)

    Obashi, Hiroshi; Kim, Tae-Seung; Oum, Tae Hoon

    2003-01-01

    Using a unique feature of air cargo transshipment data in the Northeast Asian region, this paper identifies the critical factors that determine the transshipment route choice. Taking advantage of the variations in the transport characteristics in each origin-destination airports pair, the paper uses a discrete choice model to describe the transshipping route choice decision made by an agent (i.e., freight forwarder, consolidator, and large shipper). The analysis incorporates two major factors, monetary cost (such as line-haul cost and landing fee) and time cost (i.e., aircraft turnaround time, including loading and unloading time, custom clearance time, and expected scheduled delay), along with other controls. The estimation method considers the presence of unobserved attributes, and corrects for resulting endogeneity by use of appropriate instrumental variables. Estimation results find that transshipment volumes are more sensitive to time cost, and that the reduction in aircraft turnaround time by 1 hour would be worth the increase in airport charges by more than $1000. Simulation exercises measures the impacts of alternative policy scenarios for a Korean airport, which has recently declared their intention to be a future regional hub in the Northeast Asian region. The results suggest that reducing aircraft turnaround time at the airport be an effective strategy, rather than subsidizing to reduce airport charges.

  12. Modeling the Transport and Chemical Evolution of Onshore and Offshore Emissions and their Impact on Local and Regional Air Quality Using a Variable-Grid-Resolution Air Quality Model

    SciTech Connect

    Kiran Alapaty

    2004-10-16

    This semiannual report summarizes the research performed from 17 April through 16 October 2004. Major portions of the research in several of the project's current eight tasks have been completed, and the results obtained are briefly presented. We have successfully developed the meteorological inputs using the best possible modeling configurations, resulting in improved representation of atmospheric processes. Ingestion of satellite-derived sea surface temperatures in conjunction with the use of our new surface data assimilation technique have resulted in largely improved meteorological inputs to drive the MAQSIP-VGR. The development of the variable-grid-resolution emissions model, SMOKE-VGR, is also largely complete. We expect to develop the final configuration of the SMOKE-VGR during the upcoming reporting period. We are in the process of acquiring the newly released emissions database and offshore emissions data sets to update our archives. The development of the MAQSIP-VGR has been completed and a test run was performed to ensure the functionality of this air quality model. During the upcoming reporting period, we expect to perform the first MAQSIP-VGR simulations over the Houston-Galveston region to study the roles of the meteorology, offshore emissions, and chemistry-transport interactions that determine the temporal and spatial evolution of ozone and its precursors.

  13. NODA for EPA's Updated Ozone Transport Modeling

    EPA Pesticide Factsheets

    Find EPA's NODA for the Updated Ozone Transport Modeling Data for the 2008 Ozone National Ambient Air Quality Standard (NAAQS) along with the ExitExtension of Public Comment Period on CSAPR for the 2008 NAAQS.

  14. Lagrangian Sampling of 3-D Air Quality Model Results for Regional Transport Contributions to Sulfate Aerosol Concentrations at Baltimore, MD in Summer of 2004

    EPA Science Inventory

    The Lagrangian method provides estimates of the chemical and physical evolution of air arriving in the daytime boundary layer at Baltimore. Study results indicate a dominant role for regional transport contributions of those days when sulfate air pollution is highest in Baltimor...

  15. Transport and urban air pollution in India.

    PubMed

    Badami, Madhav G

    2005-08-01

    The rapid growth in motor vehicle activity in India and other rapidly industrializing low-income countries is contributing to high levels of urban air pollution, among other adverse socioeconomic, environmental, health, and welfare impacts. This paper first discusses the local, regional, and global impacts associated with air pollutant emissions resulting from motor vehicle activity, and the technological, behavioral, and institutional factors that have contributed to these emissions, in India. The paper then discusses some implementation issues related to various policy measures that have been undertaken, and the challenges of the policy context. Finally, the paper presents insights and lessons based on the recent Indian experience, for better understanding and more effectively addressing the transport air pollution problem in India and similar countries, in a way that is sensitive to their needs, capabilities, and constraints.

  16. 29 CFR 1202.12 - National Air Transport Adjustment Board.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... § 1202.12 National Air Transport Adjustment Board. Under section 205, title II, of the Railway Labor Act... 29 Labor 4 2010-07-01 2010-07-01 false National Air Transport Adjustment Board. 1202.12 Section... four representatives to constitute a Board known as the National Air Transport Adjustment Board....

  17. 29 CFR 1202.12 - National Air Transport Adjustment Board.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... § 1202.12 National Air Transport Adjustment Board. Under section 205, title II, of the Railway Labor Act... 29 Labor 4 2011-07-01 2011-07-01 false National Air Transport Adjustment Board. 1202.12 Section... four representatives to constitute a Board known as the National Air Transport Adjustment Board....

  18. Hybrid regional air pollution models

    SciTech Connect

    Drake, R.L.

    1980-03-01

    This discussion deals with a family of air quality models for predicting and analyzing the fine particulate loading in the atmosphere, for assessing the extent and degree of visibility impairment, and for determining the potential of pollutants for increasing the acidity of soils and water. The major horizontal scales of interest are from 400km to 2000km; and the time scales may vary from several hours, to days, weeks, and a few months or years, depending on the EPA regulations being addressed. First the role air quality models play in the general family of atmospheric simulation models is described. Then, the characteristics of a well-designed, comprehensive air quality model are discussed. Following this, the specific objectives of this workshop are outlined, and their modeling implications are summarized. There are significant modeling differences produced by the choice of the coordinate system, whether it be the fixed Eulerian system, the moving Lagrangian system, or some hybrid of the two. These three systems are briefly discussed, and a list of hybrid models that are currently in use are given. Finally, the PNL regional transport model is outlined and a number of research needs are listed.

  19. The magnitude and spatial range of current-use urban PCB and PBDE emissions estimated using a coupled multimedia and air transport model.

    PubMed

    Csiszar, Susan A; Diamond, Miriam L; Daggupaty, Sreerama M

    2014-01-21

    SO-MUM, a coupled atmospheric transport and multimedia urban model, was used to estimate spatially resolved (5 × 5 km(2)) air emissions and chemical fate based on measured air concentrations and chemical mass inventories within Toronto, Canada. Approximately 95% and 70% of Σ5PCBs (CB-28, -52, -101, -153, and -180) and Σ5PBDEs (BDE-28, -47, -100, -154, and -183) emissions of 17 (2-36) and 18 (3-42) kg y(-1), respectively, undergo atmospheric transport from the city, which is partly over Lake Ontario. The urban air plume was found to reach about 50 km for PCBs and PBDEs, in the direction of prevailing winds which is almost twice the distance of the wind-independent plume. The distance traveled by the plume is a function of prevailing wind velocity, the geographic distribution of the chemical inventory, and gas-particle partitioning. Soil wash-off of historically accumulated Σ5PCBs to surface water contributed ∼ 0.4 kg y(-1) (of mainly higher congeners) to near-shore Lake Ontario compared with volatilization of ∼ 6 kg y(-1) of mainly lighter congeners. Atmospheric emissions from primary sources followed by deposition to surface films and subsequent wash-off to surface water contributed ∼ 1 kg y(-1) and was the main route of Σ5PBDE loadings to near-shore Lake Ontario which acts as a net PBDE sink. Secondary emissions of PCBs and PBDEs from at least a ∼ 900,000 km(2) rural land area would be needed to produce the equivalent primary emissions as Toronto (∼ 640 km(2)). These results provide clear support for reducing inventories of these POPs.

  20. Principle Component Analysis of the Evolution of the Saharan Air Layer and Dust Transport: Comparisons between a Model Simulation and MODIS Retrievals

    NASA Technical Reports Server (NTRS)

    Wong, S.; Colarco, P. R.; Dessler, A.

    2006-01-01

    The onset and evolution of Saharan Air Layer (SAL) episodes during June-September 2002 are diagnosed by applying principal component analysis to the NCEP reanalysis temperature anomalies at 850 hPa, where the largest SAL-induced temperature anomalies are located. The first principal component (PC) represents the onset of SAL episodes, which are associated with large warm anomalies located at the west coast of Africa. The second PC represents two opposite phases of the evolution of the SAL. The positive phase of the second PC corresponds to the southwestward extension of the warm anomalies into the tropical-subtropical North Atlantic Ocean, and the negative phase corresponds to the northwestward extension into the subtropical to mid-latitude North Atlantic Ocean and the southwest Europe. A dust transport model (CARMA) and the MODIS retrievals are used to study the associated effects on dust distribution and deposition. The positive (negative) phase of the second PC corresponds to a strengthening (weakening) of the offshore flows in the lower troposphere around 10deg - 20degN, causing more (less) dust being transported along the tropical to subtropical North Atlantic Ocean. The variation of the offshore flow indicates that the subseasonal variation of African Easterly Jet is associated with the evolution of the SAL. Significant correlation is found between the second PC time series and the daily West African monsoon index, implying a dynamical linkage between West African monsoon and the evolution of the SAL and Saharan dust transport.

  1. Estimates of radioxenon released from Southern Hemisphere medical isotope production facilities using measured air concentrations and atmospheric transport modeling.

    PubMed

    Eslinger, Paul W; Friese, Judah I; Lowrey, Justin D; McIntyre, Justin I; Miley, Harry S; Schrom, Brian T

    2014-09-01

    The International Monitoring System (IMS) of the Comprehensive-Nuclear-Test-Ban-Treaty monitors the atmosphere for radioactive xenon leaking from underground nuclear explosions. Emissions from medical isotope production represent a challenging background signal when determining whether measured radioxenon in the atmosphere is associated with a nuclear explosion prohibited by the treaty. The Australian Nuclear Science and Technology Organisation (ANSTO) operates a reactor and medical isotope production facility in Lucas Heights, Australia. This study uses two years of release data from the ANSTO medical isotope production facility and (133)Xe data from three IMS sampling locations to estimate the annual releases of (133)Xe from medical isotope production facilities in Argentina, South Africa, and Indonesia. Atmospheric dilution factors derived from a global atmospheric transport model were used in an optimization scheme to estimate annual release values by facility. The annual releases of about 6.8 × 10(14) Bq from the ANSTO medical isotope production facility are in good agreement with the sampled concentrations at these three IMS sampling locations. Annual release estimates for the facility in South Africa vary from 2.2 × 10(16) to 2.4 × 10(16) Bq, estimates for the facility in Indonesia vary from 9.2 × 10(13) to 3.7 × 10(14) Bq and estimates for the facility in Argentina range from 4.5 × 10(12) to 9.5 × 10(12) Bq.

  2. Estimates of Radioxenon Released from Southern Hemisphere Medical isotope Production Facilities Using Measured Air Concentrations and Atmospheric Transport Modeling

    SciTech Connect

    Eslinger, Paul W.; Friese, Judah I.; Lowrey, Justin D.; McIntyre, Justin I.; Miley, Harry S.; Schrom, Brian T.

    2014-09-01

    Abstract The International Monitoring System (IMS) of the Comprehensive-Nuclear-Test-Ban-Treaty monitors the atmosphere for radioactive xenon leaking from underground nuclear explosions. Emissions from medical isotope production represent a challenging background signal when determining whether measured radioxenon in the atmosphere is associated with a nuclear explosion prohibited by the treaty. The Australian Nuclear Science and Technology Organisation (ANSTO) operates a reactor and medical isotope production facility in Lucas Heights, Australia. This study uses two years of release data from the ANSTO medical isotope production facility and Xe-133 data from three IMS sampling locations to estimate the annual releases of Xe-133 from medical isotope production facilities in Argentina, South Africa, and Indonesia. Atmospheric dilution factors derived from a global atmospheric transport model were used in an optimization scheme to estimate annual release values by facility. The annual releases of about 6.8×1014 Bq from the ANSTO medical isotope production facility are in good agreement with the sampled concentrations at these three IMS sampling locations. Annual release estimates for the facility in South Africa vary from 1.2×1016 to 2.5×1016 Bq and estimates for the facility in Indonesia vary from 6.1×1013 to 3.6×1014 Bq. Although some releases from the facility in Argentina may reach these IMS sampling locations, the solution to the objective function is insensitive to the magnitude of those releases.

  3. DEVELOPMENTS AND APPLICATIONS OF CFD SIMULATIONS OF MICROMETEOROLOGY AND POLLUTION TRANSPORT IN SUPPORT OF AIR QUALITY MODELING

    EPA Science Inventory

    Development and application of computational fluid dynamics (CFD) simulations are being advanced through case studies for simulating air pollutant concentrations from sources within open fields and within complex urban building environments. CFD applications have been under deve...

  4. AIR Model Preflight Analysis

    NASA Technical Reports Server (NTRS)

    Tai, H.; Wilson, J. W.; Maiden, D. L.

    2003-01-01

    The atmospheric ionizing radiation (AIR) ER-2 preflight analysis, one of the first attempts to obtain a relatively complete measurement set of the high-altitude radiation level environment, is described in this paper. The primary thrust is to characterize the atmospheric radiation and to define dose levels at high-altitude flight. A secondary thrust is to develop and validate dosimetric techniques and monitoring devices for protecting aircrews. With a few chosen routes, we can measure the experimental results and validate the AIR model predictions. Eventually, as more measurements are made, we gain more understanding about the hazardous radiation environment and acquire more confidence in the prediction models.

  5. Air pollution in the Benelux/Rhine-Ruhr area: Numerical simulations with a multi-scale regional chemistry-transport model

    NASA Astrophysics Data System (ADS)

    Memmesheimer, M.; Jakobs, H. J.; Wurzler, S.; Friese, E.; Piekorz, G.; Ebel, A.

    2009-04-01

    The Rhine-Ruhr area is a strongly industrialized region with about 10 Million inhabitants. It is one of the regions in Europe, which has the characteristics of a megacity with respect to population density, traffic, industry and environmental issues. The main centre of European steel production and the biggest inland port of the world is located in Duisburg, one of the major cities in the Rhine-Ruhr area. Together with the nearby urban agglomerations in the Benelux area including Brussels, Amsterdam and in particular Rotterdam as one of the most important sea-harbours of the world together with Singapore and Shanghai, it forms one of the regions in Europe heavily loaded with air pollutants as ozone, NO2 and particulate matter. Ammonia emissions outside the urban agglomerations but within the domain are also on a quite high level due to intense agricultural usage in Benelux, North-Rhine-Westphalia and lower Saxony. Therefore this area acts also as an important source region for gaseous precursors contributing to the formation of secondary particles in the atmosphere. The Benelux/Rhine-Ruhr area therefore has been selected within the framework of the recently established FP7 research project CityZen as one hot spot for detailed investigations of the past and current status of air pollution and its future development on different spatial and temporal scales. Some examples from numerical simulations with the regional multi-scale chemistry transport model EURAD for Central Europe and the Rhine-Ruhr area will be presented. The model calculates the transport, chemical transformations and deposition of trace constituents in the troposphere from the surface up to about 16 km using MM5 as meteorological driver, the RACM-MIM gas-phase chemistry and MADE-SORGAM for the treatment of particulate matter. Horizontal grid sizes are in the range of 100 km down to 1 km for heavily polluted urbanized areas within Benelux/Rhine-Ruhr. The planetary boundary layer is resolved by 15

  6. Modelin the Transport and Chemical Evolution of Onshore and Offshore Emissions and Their Impact on Local and Regional Air Quality Using a Variable-Grid-Resolution Air Quality Model

    SciTech Connect

    Adel Hanna

    2008-10-16

    The overall objective of this research project was to develop an innovative modeling technique to adequately model the offshore/onshore transport of pollutants. The variable-grid modeling approach that was developed alleviates many of the shortcomings of the traditionally used nested regular-grid modeling approach, in particular related to biases near boundaries and the excessive computational requirements when using nested grids. The Gulf of Mexico region contiguous to the Houston-Galveston area and southern Louisiana was chosen as a test bed for the variable-grid modeling approach. In addition to the onshore high pollution emissions from various sources in those areas, emissions from on-shore and off-shore oil and gas exploration and production are additional sources of air pollution. We identified case studies for which to perform meteorological and air quality model simulations. Our approach included developing and evaluating the meteorological, emissions, and chemistry-transport modeling components for the variable-grid applications, with special focus on the geographic areas where the finest grid resolution was used. We evaluated the performance of two atmospheric boundary layer (ABL) schemes, and identified the best-performing scheme for simulating mesoscale circulations for different grid resolutions. Use of a newly developed surface data assimilation scheme resulted in improved meteorological model simulations. We also successfully ingested satellite-derived sea surface temperatures (SSTs) into the meteorological model simulations, leading to further improvements in simulated wind, temperature, and moisture fields. These improved meteorological fields were important for variable-grid simulations, especially related to capturing the land-sea breeze circulations that are critical for modeling offshore/onshore transport of pollutants in the Gulf region. We developed SMOKE-VGR, the variable-grid version of the SMOKE emissions processing model, and tested and

  7. Proceedings of the Air Transportation Management Workshop

    NASA Technical Reports Server (NTRS)

    Tobias, Leonard (Editor); Tashker, Michael G. (Editor); Boyle, Angela M. (Editor)

    1995-01-01

    The Air Transportation Management (ATM) Workshop was held 31 Jan. - 1 Feb. 1995 at NASA Ames Research Center. The purpose of the workshop was to develop an initial understanding of user concerns and requirements for future ATM capabilities and to initiate discussions of alternative means and technologies for achieving more effective ATM capabilities. The topics for the sessions were as follows: viewpoints of future ATM capabilities, user requirements, lessons learned, and technologies for ATM. In addition, two panel sessions discussed priorities for ATM, and potential contributions of NASA to ATM. The proceedings contain transcriptions of all sessions.

  8. Operating systems in the air transportation environment.

    NASA Technical Reports Server (NTRS)

    Cherry, G. W.

    1971-01-01

    Consideration of the problems facing air transport at present, and to be expected in the future. In the Northeast Corridor these problems involve community acceptance, airway and airport congestion and delays, passenger acceptance, noise reduction, and improvements in low-density short-haul economics. In the development of a superior short-haul operating system, terminal-configured vs cruise-configured vehicles are evaluated. CTOL, STOL, and VTOL aircraft of various types are discussed. In the field of noise abatement, it is shown that flight procedural techniques are capable of supplementing ?quiet engine' technology.

  9. [Long-haul intensive care transports by air].

    PubMed

    Graf, Jürgen; Seiler, Olivier; Pump, Stefan; Günther, Marion; Albrecht, Roland

    2013-03-01

    The need for inter-hospital transports over long distances aboard air ambulances or airlines has increased in recent years, both in the civil as well as the military sector. More often severely ill intensive care patients with multiple organ failure and appropriate supportive care (e.g. mechanical ventilation, catecholamines, dialysis, cardiac assist devices) are transported by air. Despite the fact that long-haul intensive care transports by air ambulance and airlines via Patient Transport Compartment (PTC) are considered established modes of transport they always provide a number of challenges. Both modes of transport have distinct logistical and medical advantages and disadvantages. These-as well as the principal risks of an air-bound long-haul intensive care transport -have to be included in the risk assessment and selection of means of transport. Very often long-haul intensive care transports are a combination of air ambulance and scheduled airlines utilizing the PTC.

  10. Railway switch transport model.

    PubMed

    Horvat, Martin; Prosen, Tomaž; Benenti, Giuliano; Casati, Giulio

    2012-11-01

    We propose a simple model of coupled heat and particle transport based on zero-dimensional classical deterministic dynamics, which is reminiscent of a railway switch whose action is a function only of the particle's energy. It is shown that already in the minimal three-terminal model, where the second terminal is considered as a probe with zero net particle and heat currents, one can find extremely asymmetric Onsager matrices as a consequence of time-reversal symmetry breaking of the model. This minimalistic transport model provides a better understanding of thermoelectric heat engines in the presence of time-reversal symmetry breaking.

  11. An Integrated Safety Analysis Methodology for Emerging Air Transport Technologies

    NASA Technical Reports Server (NTRS)

    Kostiuk, Peter F.; Adams, Milton B.; Allinger, Deborah F.; Rosch, Gene; Kuchar, James

    1998-01-01

    The continuing growth of air traffic will place demands on NASA's Air Traffic Management (ATM) system that cannot be accommodated without the creation of significant delays and economic impacts. To deal with this situation, work has begun to develop new approaches to providing a safe and economical air transportation infrastructure. Many of these emerging air transport technologies will represent radically new approaches to ATM, both for ground and air operations.

  12. 49 CFR 1544.223 - Transportation of Federal Air Marshals.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 9 2011-10-01 2011-10-01 false Transportation of Federal Air Marshals. 1544.223 Section 1544.223 Transportation Other Regulations Relating to Transportation (Continued) TRANSPORTATION SECURITY ADMINISTRATION, DEPARTMENT OF HOMELAND SECURITY CIVIL AVIATION SECURITY AIRCRAFT OPERATOR...

  13. 49 CFR 1544.223 - Transportation of Federal Air Marshals.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 9 2014-10-01 2014-10-01 false Transportation of Federal Air Marshals. 1544.223 Section 1544.223 Transportation Other Regulations Relating to Transportation (Continued) TRANSPORTATION SECURITY ADMINISTRATION, DEPARTMENT OF HOMELAND SECURITY CIVIL AVIATION SECURITY AIRCRAFT OPERATOR...

  14. 49 CFR 1544.223 - Transportation of Federal Air Marshals.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 9 2012-10-01 2012-10-01 false Transportation of Federal Air Marshals. 1544.223 Section 1544.223 Transportation Other Regulations Relating to Transportation (Continued) TRANSPORTATION SECURITY ADMINISTRATION, DEPARTMENT OF HOMELAND SECURITY CIVIL AVIATION SECURITY AIRCRAFT OPERATOR...

  15. 49 CFR 1544.223 - Transportation of Federal Air Marshals.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 9 2013-10-01 2013-10-01 false Transportation of Federal Air Marshals. 1544.223 Section 1544.223 Transportation Other Regulations Relating to Transportation (Continued) TRANSPORTATION SECURITY ADMINISTRATION, DEPARTMENT OF HOMELAND SECURITY CIVIL AVIATION SECURITY AIRCRAFT OPERATOR...

  16. 49 CFR 1544.223 - Transportation of Federal Air Marshals.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 9 2010-10-01 2010-10-01 false Transportation of Federal Air Marshals. 1544.223 Section 1544.223 Transportation Other Regulations Relating to Transportation (Continued) TRANSPORTATION SECURITY ADMINISTRATION, DEPARTMENT OF HOMELAND SECURITY CIVIL AVIATION SECURITY AIRCRAFT OPERATOR...

  17. Lagrangian Sediment Transport Model

    NASA Astrophysics Data System (ADS)

    Maderych, V.; Brovchenko, I.; Fenical, S.; Shepsis, V.

    2004-12-01

    A new two-dimensional Lagrangian sediment transport model was developed to simulate a wide-range of sediment transport processes, including sediment mobility under combined current and wave action, sediment transport and bed change under wave and currents effects, sediment transport patterns at nearshore coastal and offshore structures, and turbidity and sediment motion during dredging and dredged material placement. The Lagrangian technique was used to simulate transport of sediments, deposition, and re-suspension. The model can be applied to cohesive, non-cohesive, or mixed sediments. The sediment transport is simulated using bathymetry data, bed resistance characteristics, wave height and period, depth-averaged current velocity and bed material type, size and gradation, which vary throughout the model domain.The non-cohesive sediment transport model is based on a solution of two-dimensional mass conservation equations for the bed layer material and 2D equations for movement of sediment fractions either bed load or suspended load. The water column and bottom are divided into a set of layers: water layer, active layer, several active bed layers, and the bed layer. The model also takes into account the effects of armoring and changes in the bed composition. Cohesive sediments move entirely as suspended load in the water layer and sediment transport computations are based on a solution of the two-dimensional mass conservation equations for the bed layer material and two-dimensional equations for movement of sediment as suspended load. The water column and bed, as for non-cohesive sediments, was divided into a set of layers. Following the approach of Van Ledden (2002), the erosion of sediments made up of mud and sand mixtures is non-cohesive if the mud content is below a critical level. Above a critical mud content, the bed behaves cohesively. Deposition fluxes of mud and sand are independent. The sediment concentration in the water and active layer is represented by

  18. Systems evaluation of low density air transportation concepts

    NASA Technical Reports Server (NTRS)

    Bruce, R. W.; Webb, H. M.

    1972-01-01

    Methods were studied for improving air transportation to low-density population regions in the U.S. through the application of new aeronautical technology. The low-density air service concepts are developed for selected regions, and critical technologies that presently limit the effective application of low-density air transportation systems are identified.

  19. 49 CFR 1510.7 - Air transportation advertisements and solicitations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 9 2010-10-01 2010-10-01 false Air transportation advertisements and... PASSENGER CIVIL AVIATION SECURITY SERVICE FEES § 1510.7 Air transportation advertisements and solicitations... part as “September 11th Security Fee” in all its advertisements and solicitations for...

  20. MODELING THE TRANSPORT AND CHEMICAL EVOLUTION OF ONSHORE AND OFFSHORE EMISSIONS AND THEIR IMPACT ON LOCAL AND REGIONAL AIR QUALITY USING A VARIABLE-GRID-RESOLUTION AIR QUALITY MODEL

    SciTech Connect

    Kiran Alapaty

    2003-12-01

    This document, the project's first semiannual report, summarizes the research performed from 04/17/2003 through 10/16/2003. Portions of the research in several of the project's eight tasks were completed, and results obtained are briefly presented. We have tested the applicability of two different atmospheric boundary layer schemes for use in air quality model simulations. Preliminary analysis indicates that a scheme that uses sophisticated atmospheric boundary physics resulted in better simulation of atmospheric circulations. We have further developed and tested a new surface data assimilation technique to improve meteorological simulations, which will also result in improved air quality model simulations. Preliminary analysis of results indicates that using the new data assimilation technique results in reduced modeling errors in temperature and moisture. Ingestion of satellite-derived sea surface temperatures into the mesoscale meteorological model led to significant improvements in simulated clouds and precipitation compared to that obtained using traditional analyzed sea surface temperatures. To enhance the capabilities of an emissions processing system so that it can be used with our variable-grid-resolution air quality model, we have identified potential areas for improvements. Also for use in the variable-grid-resolution air quality model, we have tested a cloud module offline for its functionality, and have implemented and tested an efficient horizontal diffusion algorithm within the model.

  1. Seasonal cycle and interannual variability of the total CH4 mixing ratios in West Siberia: Results from AIRS/AMSU and chemistry transport models for 2003-2013

    NASA Astrophysics Data System (ADS)

    Lagutin, Anatoly; Mordvin, Egor

    Methane (CH4) is an important greenhouse gas. It has much higher global warming potential comparing to carbon dioxide on per mass emitted basis. Atmospheric methane also plays an important role in atmospheric ozone chemistry and is the main source of water vapor in the stratosphere. The recent increase of CH4 in 2007-2008, after a nearly stable period of about one decade, is attributed to the increased emissions from tropical and Arctic wetlands. However, many uncertainties regarding natural and anthropogenic methane emissions still exist. For example, the total CH4 emissions from wetlands in West Siberia are estimated to be in the range from 1.6 to 20 Tg/year. The main causes leading to such large uncertainties are significant spatial and temporal variation of CH4 emissions and the sparseness of ground observational networks. The purpose of this study is to investigate the seasonal cycle and interannual variability of the total CH4 mixing ratios (CH4-Tot) in West Siberia for 2003-2013 using the AIRS/AMSU-Aqua measurements and the results from chemistry transport models MOZART4 and ACTM-CCSR/NIES/FRCGC. The key feature of the proposed approach is chemistry transport model-based regression equation linking CH4-Tot with mid-upper tropospheric CH4 (in the layer from 50 to 250 hPa below the tropopause), the tropopause height and the surface temperature. The observational information in our approach comes from the AIRS/AMSU measurements. Comparison of the retrieved CH4-Tot with the measurements of CH4 from the Total Carbon Column Observing Network (TCCON) have shown that the model captures observed seasonal cycles and interannual variability at mid-latitude sites. The spatial and temporal distributions of CH4-Tot in West Siberia for 2003-2013 are presented. Analysis of deseasonalized time-series indicates that the total CH4 mixing ratios increases about 4 ppbv/yr from 2007. This work was supported in part by the Russian Foundation for Basic Research (grant No 13

  2. Maximizing algebraic connectivity in air transportation networks

    NASA Astrophysics Data System (ADS)

    Wei, Peng

    In air transportation networks the robustness of a network regarding node and link failures is a key factor for its design. An experiment based on the real air transportation network is performed to show that the algebraic connectivity is a good measure for network robustness. Three optimization problems of algebraic connectivity maximization are then formulated in order to find the most robust network design under different constraints. The algebraic connectivity maximization problem with flight routes addition or deletion is first formulated. Three methods to optimize and analyze the network algebraic connectivity are proposed. The Modified Greedy Perturbation Algorithm (MGP) provides a sub-optimal solution in a fast iterative manner. The Weighted Tabu Search (WTS) is designed to offer a near optimal solution with longer running time. The relaxed semi-definite programming (SDP) is used to set a performance upper bound and three rounding techniques are discussed to find the feasible solution. The simulation results present the trade-off among the three methods. The case study on two air transportation networks of Virgin America and Southwest Airlines show that the developed methods can be applied in real world large scale networks. The algebraic connectivity maximization problem is extended by adding the leg number constraint, which considers the traveler's tolerance for the total connecting stops. The Binary Semi-Definite Programming (BSDP) with cutting plane method provides the optimal solution. The tabu search and 2-opt search heuristics can find the optimal solution in small scale networks and the near optimal solution in large scale networks. The third algebraic connectivity maximization problem with operating cost constraint is formulated. When the total operating cost budget is given, the number of the edges to be added is not fixed. Each edge weight needs to be calculated instead of being pre-determined. It is illustrated that the edge addition and the

  3. Modeling the Transport and Chemical Evolution of Onshore and Offshore Emissions and their Impact on Local and Regional Air Quality Using a Variable-Grid-Resolution Air Quality Model

    SciTech Connect

    Kiran Alapaty; Adel Hanna

    2006-10-16

    This research project has two primary objectives: (1) to further develop and refine the Multiscale Air Quality Simulation Platform-Variable Grid Resolution (MAQSIP-VGR) model, an advanced variable-grid-resolution air quality model, to provide detailed, accurate representation of the dynamical and chemical processes governing the fate of anthropogenic emissions in coastal environments; and (2) to improve current understanding of the potential impact of onshore and offshore oil and gas exploration and production (E&P) emissions on O{sub 3} and particulate matter nonattainment in the Gulf of Mexico and surrounding states.

  4. Intercontinental Transport of Aerosols: Implication for Regional Air Quality

    NASA Technical Reports Server (NTRS)

    Chin, Mian; Diehl, Thomas; Ginoux, Paul

    2006-01-01

    Aerosol particles, also known as PM2.5 (particle diameter less than 2.5 microns) and PM10 (particle diameter less than 10 microns), is one of the key atmospheric components that determine ambient air quality. Current US air quality standards for PM10 (particles with diameter < 10 microns) and PM2.5 (particles with diameter 2.5 microns) are 50 pg/cu m and 15 pg/cu m, respectively. While local and regional emission sources are the main cause of air pollution problems, aerosols can be transported on a hemispheric or global scale. In this study, we use the Goddard Chemistry Aerosol Radiation and Transport (GOCART) model to quantify contributions of long-range transport vs. local/regional pollution sources and from natural vs. anthropogenic sources to PM concentrations different regions. In particular, we estimate the hemispheric impact of anthropogenic sulfate aerosols and dust from major source areas on other regions in the world. The GOCART model results are compared with satellite remote sensing and ground-based network measurements of aerosol optical depth and concentrations.

  5. Air transportation energy efficiency - Alternatives and implications

    NASA Technical Reports Server (NTRS)

    Williams, L. J.

    1976-01-01

    Results from recent studies of air transportation energy efficiency alternatives are discussed, along with some of the implications of these alternatives. The fuel-saving alternatives considered include aircraft operation, aircraft modification, derivative aircraft, and new aircraft. In the near-term, energy efficiency improvements should be possible through small improvements in fuel-saving flight procedures, higher density seating, and higher load factors. Additional small near-term improvements could be obtained through aircraft modifications, such as the relatively inexpensive drag reduction modifications. Derivatives of existing aircraft could meet the requirements for new aircraft and provide energy improvements until advanced technology is available to justify the cost of a completely new design. In order to obtain significant improvements in energy efficiency, new aircraft must truly exploit advanced technology in such areas as aerodynamics, composite structures, active controls, and advanced propulsion.

  6. Combined Heat, Air, Moisture, and Pollutants Transport in Building Environmental Systems

    NASA Astrophysics Data System (ADS)

    Zhang, Jianshun Jensen S.

    Combined heat, air, moisture and pollutants transport (CHAMP) exists across multi-scales of a building environmental system (BES): around the building, through the building shell/envelope, inside a multizone building, and in the micro-environments around occupants. This paper reviews previous work and presents a system model for simulating these transport processes and their impacts on indoor environmental quality. Components of the system model include a multizone network flow model for whole building, a room model for air and pollutant movement in ventilated spaces, a coupled heat, air, moisture, and pollutant transport model for building shell, an HVAC model for describing the dynamics of the heating, ventilating and air-conditioning (HVAC) system, and shared databases of weather conditions, transport properties of building materials, and volatile organic compounds (VOCs) emissions from building materials and furnishings. The interactions among the different components, and challenges in developing the CHAMP system model for intelligent control of BES are also discussed.

  7. Reactive transport modeling

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This special section in the Vadose Zone Journal focusing on reactive transport modeling was developed from a special symposium jointly sponsored by the Soil Physics and Soil Chemistry Divisions of the Soil Science Society of America at the 2010 annual meetings held in Long Beach, CA. It contains eig...

  8. Space Weather affects on Air Transportation

    NASA Astrophysics Data System (ADS)

    Jones, J. B. L.; Bentley, R. D.; Dyer, C.; Shaw, A.

    In Europe, legislation requires the airline industry to monitor the occupational exposure of aircrew to cosmic radiation. However, there are other significant impacts of space weather phenomena on the technological systems used for day-to-day operations which need to be considered by the airlines. These were highlighted by the disruption caused to the industry by the period of significant solar activity in late October and early November 2003. Next generation aircraft will utilize increasingly complex avionics as well as expanding the performance envelopes. These and future generation platforms will require the development of a new air-space management infrastructure with improved position accuracy (for route navigation and landing in bad weather) and reduced separation minima in order to cope with the expected growth in air travel. Similarly, greater reliance will be placed upon satellites for command, control, communication and information (C3I) of the operation. However, to maximize effectiveness of this globally interoperable C3I and ensure seamless fusion of all components for a safe operation will require a greater understanding of the space weather affects, their risks with increasing technology, and the inclusion of space weather information into the operation. This paper will review space weather effects on air transport and the increasing risks for future operations cause by them. We will examine how well the effects can be predicted, some of the tools that can be used and the practicalities of using such predictions in an operational scenario. Initial results from the SOARS ESA Space Weather Pilot Project will also be discussed,

  9. UK airmisses involving commercial air transport, January-April 1991

    NASA Astrophysics Data System (ADS)

    In the introduction the following are briefly discussed: origination of an airmiss; purpose of airmiss reports; investigation of airmiss reports; categorization of airmisses; involvement of commercial air transport aircraft; airmisses related to flying hours. Tabulated statistics of the following are presented: the number of incidents of commercial air transport airmisses; commercial air transport aircraft involved in airmisses; commercial air transport airmisses related to flying hours. Reports on the commercial air transport airmisses from Jan. - Apr. 1991 are presented. These contain summaries of: pilot reports, transcripts of relevant RT frequencies; radar video recordings, and reports from appropriate air traffic control and operating authorities. The working groups discussion is summarized, and the risk and cause assessed.

  10. A design methodology for evolutionary air transportation networks

    NASA Astrophysics Data System (ADS)

    Yang, Eunsuk

    The air transportation demand at large hubs in the U.S. is anticipated to double in the near future. Current runway construction plans at selected airports can relieve some capacity and delay problems, but many are doubtful that this solution is sufficient to accommodate the anticipated demand growth in the National Airspace System (NAS). With the worsening congestion problem, it is imperative to seek alternative solutions other than costly runway constructions. In this respect, many researchers and organizations have been building models and performing analyses of the NAS. However, the complexity and size of the problem results in an overwhelming task for transportation system modelers. This research seeks to compose an active design algorithm for an evolutionary airline network model so as to include network specific control properties. An airline network designer, referred to as a network architect, can use this tool to assess the possibilities of gaining more capacity by changing the network configuration. Since the Airline Deregulation Act of 1978, the airline service network has evolved into a distinct Hub-and-Spoke (H&S) network. Enplanement demand on the H&S network is the sum of Origin-Destination (O-D) demand and transfer demand. Even though the flight or enplanement demand is a function of O-D demand and passenger routings on the airline network, the distinction between enplanement and O-D demand is not often made. Instead, many demand forecast practices in current days are based on scale-ups from the enplanements, which include the demand to and from transferring network hubs. Based on this research, it was found that the current demand prediction practice can be improved by dissecting enplanements further into smaller pieces of information. As a result, enplanement demand is decomposed into intrinsic and variable parts. The proposed intrinsic demand model is based on the concept of 'true' O-D demand which includes the direction of each round trip

  11. 10 CFR 71.88 - Air transport of plutonium.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 2 2014-01-01 2014-01-01 false Air transport of plutonium. 71.88 Section 71.88 Energy... Controls and Procedures § 71.88 Air transport of plutonium. (a) Notwithstanding the provisions of any... citation of 49 CFR chapter I, as may be applicable, the licensee shall assure that plutonium in any...

  12. 10 CFR 71.88 - Air transport of plutonium.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Air transport of plutonium. 71.88 Section 71.88 Energy... Controls and Procedures § 71.88 Air transport of plutonium. (a) Notwithstanding the provisions of any... citation of 49 CFR chapter I, as may be applicable, the licensee shall assure that plutonium in any...

  13. 10 CFR 71.88 - Air transport of plutonium.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 2 2013-01-01 2013-01-01 false Air transport of plutonium. 71.88 Section 71.88 Energy... Controls and Procedures § 71.88 Air transport of plutonium. (a) Notwithstanding the provisions of any... citation of 49 CFR chapter I, as may be applicable, the licensee shall assure that plutonium in any...

  14. 10 CFR 71.88 - Air transport of plutonium.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 2 2011-01-01 2011-01-01 false Air transport of plutonium. 71.88 Section 71.88 Energy... Controls and Procedures § 71.88 Air transport of plutonium. (a) Notwithstanding the provisions of any... citation of 49 CFR chapter I, as may be applicable, the licensee shall assure that plutonium in any...

  15. 10 CFR 71.88 - Air transport of plutonium.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 2 2012-01-01 2012-01-01 false Air transport of plutonium. 71.88 Section 71.88 Energy... Controls and Procedures § 71.88 Air transport of plutonium. (a) Notwithstanding the provisions of any... citation of 49 CFR chapter I, as may be applicable, the licensee shall assure that plutonium in any...

  16. 14 CFR 221.5 - Unauthorized air transportation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Unauthorized air transportation. 221.5... PROCEEDINGS) ECONOMIC REGULATIONS TARIFFS General § 221.5 Unauthorized air transportation. Tariff publications shall not contain fares or charges, or their governing provisions, applicable to foreign...

  17. 14 CFR 221.5 - Unauthorized air transportation.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Unauthorized air transportation. 221.5... PROCEEDINGS) ECONOMIC REGULATIONS TARIFFS General § 221.5 Unauthorized air transportation. Tariff publications shall not contain fares or charges, or their governing provisions, applicable to foreign...

  18. 22 CFR 226.1003 - Air transportation. [Reserved

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Air transportation. 226.1003 Section 226.1003 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT ADMINISTRATION OF ASSISTANCE AWARDS TO U.S. NON-GOVERNMENTAL ORGANIZATIONS USAID-Specific Requirements § 226.1003 Air transportation....

  19. Air modeling: Air dispersion models; regulatory applications and technological advances

    SciTech Connect

    Miller, M.; Liles, R.

    1995-09-01

    Air dispersion models are a useful and practical tool for both industry and regulatory agencies. They serve as tools for engineering, permitting, and regulations development. Their cost effectiveness and ease of implementation compared to ambient monitoring is perhaps their most-appealing trait. Based on the current momentum within the U.S. EPA to develop better models and contain regulatory burdens on industry, it is likely that air dispersion modeling will be a major player in future air regulatory initiatives.

  20. Transport of continental air to the subantarctic Indian Ocean

    NASA Technical Reports Server (NTRS)

    Balkanski, Yves J.; Jacob, Daniel J.

    1990-01-01

    The occurrence of high Rn-222 episodes (radonic storms) observed at three islands (Crozet, Kerguelen, and Amsterdam) in the subantarctic Indian Ocean is simulated using a three-dimensional chemical tracer model. The chemical tracer model is described and the simulated time series of Rn-222 concentrations at the three islands are compared to observations. The origin, seasonal frequencies, and periodicities of the storms are examined. It is found that the storms are due to fast boundary layer advection of air from South Africa, made possible by the conjunction of a subtropical high SE of Madagascar and a midlatitudes low off the southern tip of Africa. The implications of the results for the transport of continental air to the subantarctic Indian Ocean are discussed.

  1. Modeling, Monitoring and Fault Diagnosis of Spacecraft Air Contaminants

    NASA Technical Reports Server (NTRS)

    Ramirez, W. Fred; Skliar, Mikhail; Narayan, Anand; Morgenthaler, George W.; Smith, Gerald J.

    1996-01-01

    Progress and results in the development of an integrated air quality modeling, monitoring, fault detection, and isolation system are presented. The focus was on development of distributed models of the air contaminants transport, the study of air quality monitoring techniques based on the model of transport process and on-line contaminant concentration measurements, and sensor placement. Different approaches to the modeling of spacecraft air contamination are discussed, and a three-dimensional distributed parameter air contaminant dispersion model applicable to both laminar and turbulent transport is proposed. A two-dimensional approximation of a full scale transport model is also proposed based on the spatial averaging of the three dimensional model over the least important space coordinate. A computer implementation of the transport model is considered and a detailed development of two- and three-dimensional models illustrated by contaminant transport simulation results is presented. The use of a well established Kalman filtering approach is suggested as a method for generating on-line contaminant concentration estimates based on both real time measurements and the model of contaminant transport process. It is shown that high computational requirements of the traditional Kalman filter can render difficult its real-time implementation for high-dimensional transport model and a novel implicit Kalman filtering algorithm is proposed which is shown to lead to an order of magnitude faster computer implementation in the case of air quality monitoring.

  2. Air quality simulation over South Asia using Hemispheric Transport of Air Pollution version-2 (HTAP-v2) emission inventory and Model for Ozone and Related chemical Tracers (MOZART-4)

    NASA Astrophysics Data System (ADS)

    Surendran, Divya E.; Ghude, Sachin D.; Beig, G.; Emmons, L. K.; Jena, Chinmay; Kumar, Rajesh; Pfister, G. G.; Chate, D. M.

    2015-12-01

    This study presents the distribution of tropospheric ozone and related species for South Asia using the Model for Ozone and Related chemical Tracers (MOZART-4) and Hemispheric Transport of Air Pollution version-2 (HTAP-v2) emission inventory. The model present-day simulated ozone (O3), carbon monoxide (CO) and nitrogen dioxide (NO2) are evaluated against surface-based, balloon-borne and satellite-based (MOPITT and OMI) observations. The model systematically overestimates surface O3 mixing ratios (range of mean bias about: 1-30 ppbv) at different ground-based measurement sites in India. Comparison between simulated and observed vertical profiles of ozone shows a positive bias from the surface up to 600 hPa and a negative bias above 600 hPa. The simulated seasonal variation in surface CO mixing ratio is consistent with the surface observations, but has a negative bias of about 50-200 ppb which can be attributed to a large part to the coarse model resolution. In contrast to the surface evaluation, the model shows a positive bias of about 15-20 × 1017 molecules/cm2 over South Asia when compared to satellite derived CO columns from the MOPITT instrument. The model also overestimates OMI retrieved tropospheric column NO2 abundance by about 100-250 × 1013 molecules/cm2. A response to 20% reduction in all anthropogenic emissions over South Asia shows a decrease in the anuual mean O3 mixing ratios by about 3-12 ppb, CO by about 10-80 ppb and NOX by about 3-6 ppb at the surface level. During summer monsoon, O3 mixing ratios at 200 hPa show a decrease of about 6-12 ppb over South Asia and about 1-4 ppb over the remote northern hemispheric western Pacific region.

  3. Fate and Transport Modeling of Selected Chlorinated Organic Compounds at Operable Unit 1, U.S. Naval Air Station, Jacksonville, Florida

    USGS Publications Warehouse

    Davis, J. Hal

    2007-01-01

    The U.S. Naval Air Station occupies 3,800 acres adjacent to the St. Johns River in Jacksonville, Florida. The Station was placed on the U.S. Environmental Protection Agency's National Priorities List in December 1989 and is participating in the U.S. Department of Defense Installation Restoration Program, which serves to identify and remediate environmental contamination. One contaminated site, the old landfill, was designated as Operable Unit 1 (OU1) in 1989. The major source of ground-water contamination was from the disposal of waste oil and solvents into open pits, which began in the 1940s. Several remedial measures were implemented at this site to prevent the spread of contamination. Recovery trenches were installed in 1995 to collect free product. In 1998, some of the contamination was consolidated to the center of the old landfill and covered by an impermeable cap. Currently, Operable Unit 1 is being reevaluated as part of a 5-year review process to determine if the remedial actions were effective. Solute transport modeling indicated that the concentration of contaminants would have reached its maximum extent by the 1970s, after which the concentration levels would have generally declined because the pits would have ceased releasing high levels of contaminants. In the southern part of the site, monitoring well MW-19, which had some of the highest levels of contamination, showed decreases for measured and simulated concentrations of trichloroethene (TCE) and dichloroethene (DCE) from 1992 to present. Two upgradient disposal pits were simulated to have ceased releasing high levels of contamination in 1979, which consequently caused a drop in simulated concentrations. Monitoring well MW-100 had the highest levels of contamination of any well directly adjacent to a creek. Solute transport modeling substantially overestimated the concentrations of TCE, DCE, and vinyl chloride (VC) in this well. The reason for this overestimation is not clear, however, it indicates

  4. Emissions and Air Quality Impacts of Freight Transportation

    NASA Astrophysics Data System (ADS)

    Bickford, Erica

    Diesel freight vehicles (trucks + trains) are responsible for 20% of all U.S. nitrogen oxide (NOx) and 3% of fine particulate (PM2.5) emissions - pollutants that are harmful to human health. Freight tonnage is also projected to double over the next several decades, reaching 30 billion tons by 2050, increasing freight transport activity. Air quality impacts from increased activity, trade-offs between activity and vehicle technology improvements, as well as where to make infrastructure investments that encourage sustainable freight growth, are important considerations for transportation and air quality managers. To address these questions, we build a bottom-up roadway-by-roadway freight truck inventory (WIFE) and employ it to quantify emissions impacts of swapping biodiesel blends into the Midwest diesel freight truck fleet, and investigate emissions and air quality impacts of truck-to-rail freight modal shifts in the Midwest. We also evaluate the spatial and seasonal freight performance of WIFE modeled in a regional photochemical model (CMAQ) against satellite retrievals of nitrogen dioxide (NO2) from the Ozone Monitoring Instrument (OMI). Results show that spatial and seasonal distribution of biodiesel affects regional emissions impacts. Summer high-blend deployment yields a larger annual emissions reduction than year-round low-blend deployment, however, technological improvements in vehicle emissions controls between 2009 and 2018 dwarf the impacts of biodiesel. Truck-to-rail modal shift analysis found 40% of daily freight truck VMT could be shifted to rail freight, causing a 26% net reduction in NOx emissions, and 31% less carbon dioxide (CO2) emissions. Despite significant emissions impacts, air quality modeling results showed mostly localized near roadway air quality improvements, with small regional net changes; yet, federal regulation of CO2 emissions and/or rising costs of diesel fuel could motivate shifting freight to more fuel efficient rail. Evaluation of

  5. Air Transport of Spent Nuclear Fuel (SNF) Assemblies

    SciTech Connect

    Haire, M.J.; Moses, S.D.; Shapovalov, V.I.; Morenko, A.

    2007-07-01

    Sometimes the only feasible means of shipping research reactor spent nuclear fuel (SNF) among countries is via air transport because of location or political conditions. The International Atomic Energy Agency (IAEA) has established a regulatory framework to certify air transport Type C casks. However, no such cask has been designed, built, tested, and certified. In lieu of an air transport cask, research reactor SNF has been transported using a Type B cask under an exemption with special arrangements for administrative and security controls. This work indicates that it may be feasible to transport commercial power reactor SNF assemblies via air, and that the cost is only about three times that of shipping it by railway. Optimization (i.e., reduction) of this cost factor has yet to be done. (authors)

  6. TYPE A FISSILE PACKAGING FOR AIR TRANSPORT PROJECT OVERVIEW

    SciTech Connect

    Eberl, K.; Blanton, P.

    2013-10-11

    This paper presents the project status of the Model 9980, a new Type A fissile packaging for use in air transport. The Savannah River National Laboratory (SRNL) developed this new packaging to be a light weight (<150-lb), drum-style package and prepared a Safety Analysis for Packaging (SARP) for submission to the DOE/EM. The package design incorporates unique features and engineered materials specifically designed to minimize packaging weight and to be in compliance with 10CFR71 requirements. Prototypes were fabricated and tested to evaluate the design when subjected to Normal Conditions of Transport (NCT) and Hypothetical Accident Conditions (HAC). An overview of the design details, results of the regulatory testing, and lessons learned from the prototype fabrication for the 9980 will be presented.

  7. Modeling ozone and aerosol formation and transport in the pacific northwest with the community Multi-Scale Air Quality (CMAQ) modeling system.

    PubMed

    O'Neill, Susan M; Lamb, Brian K; Chen, Jack; Claiborn, Candis; Finn, Dennis; Otterson, Sally; Figueroa, Cristiana; Bowman, Clint; Boyer, Mike; Wilson, Rob; Arnold, Jeff; Aalbers, Steven; Stocum, Jeffrey; Swab, Christopher; Stoll, Matt; Dubois, Mike; Anderson, Mary

    2006-02-15

    The Community Multi-Scale Air Quality (CMAQ) modeling system was used to investigate ozone and aerosol concentrations in the Pacific Northwest (PNW) during hot summertime conditions during July 1-15, 1996. Two emission inventories (El) were developed: emissions for the first El were based upon the National Emission Trend 1996 (NET96) database and the BEIS2 biogenic emission model, and emissions for the second El were developed through a "bottom up" approach that included biogenic emissions obtained from the GLOBEIS model. The two simulations showed that elevated PM2.5 concentrations occurred near and downwind of the Interstate-5 corridor along the foothills of the Cascade Mountains and in forested areas of central Idaho. The relative contributions of organic and inorganic aerosols varied by region, but generally organic aerosols constituted the largest fraction of PM2.5. In wilderness areas near the 1-5 corridor, organic carbon from anthropogenic sources contributed approximately 50% of the total organic carbon with the remainder from biogenic precursors, while in wilderness areas in Idaho, biogenic organic carbon accounted for 80% of the total organic aerosol. Regional analysis of the secondary organic aerosol formation in the Columbia River Gorge, Central Idaho, and the Olympics/Puget Sound showed that the production rate of secondary organic carbon depends on local terpene concentrations and the local oxidizing capacity of the atmosphere, which was strongly influenced by anthropogenic emissions. Comparison with observations from 12 IMPROVE sites and 21 ozone monitoring sites showed that results from the two El simulations generally bracketed the average observed PM parameters and that errors calculated for the model results were within acceptable bounds. Analysis across all statistical parameters indicated that the NW-AIRQUEST El solution performed better at predicting PM2.5, PM1, and beta(ext) even though organic carbon PM was over-predicted, and the NET96 El

  8. Dynamic Flow Management Problems in Air Transportation

    NASA Technical Reports Server (NTRS)

    Patterson, Sarah Stock

    1997-01-01

    In 1995, over six hundred thousand licensed pilots flew nearly thirty-five million flights into over eighteen thousand U.S. airports, logging more than 519 billion passenger miles. Since demand for air travel has increased by more than 50% in the last decade while capacity has stagnated, congestion is a problem of undeniable practical significance. In this thesis, we will develop optimization techniques that reduce the impact of congestion on the national airspace. We start by determining the optimal release times for flights into the airspace and the optimal speed adjustment while airborne taking into account the capacitated airspace. This is called the Air Traffic Flow Management Problem (TFMP). We address the complexity, showing that it is NP-hard. We build an integer programming formulation that is quite strong as some of the proposed inequalities are facet defining for the convex hull of solutions. For practical problems, the solutions of the LP relaxation of the TFMP are very often integral. In essence, we reduce the problem to efficiently solving large scale linear programming problems. Thus, the computation times are reasonably small for large scale, practical problems involving thousands of flights. Next, we address the problem of determining how to reroute aircraft in the airspace system when faced with dynamically changing weather conditions. This is called the Air Traffic Flow Management Rerouting Problem (TFMRP) We present an integrated mathematical programming approach for the TFMRP, which utilizes several methodologies, in order to minimize delay costs. In order to address the high dimensionality, we present an aggregate model, in which we formulate the TFMRP as a multicommodity, integer, dynamic network flow problem with certain side constraints. Using Lagrangian relaxation, we generate aggregate flows that are decomposed into a collection of flight paths using a randomized rounding heuristic. This collection of paths is used in a packing integer

  9. Journal of Air Transportation; Volume 9, No. 3

    NASA Technical Reports Server (NTRS)

    Bowen, Brent D. (Editor); Kabashkin, Igor (Editor)

    2004-01-01

    The mission of the Journal of Air Transportation (JAT) is to provide the global community immediate key resource information in all areas of air transportation. The goal of the Journal is to be recognized as the preeminent scholarly journal in the aeronautical aspects of transportation. As an international and interdisciplinary journal, the JAT will provide a forum for peer-reviewed articles in all areas of aviation and space transportation research, policy, theory, case study, practice, and issues. While maintaining a broad scope, a focal point of the journal will be in the area of aviation administration and policy.

  10. Journal of Air Transportation, Volume 10, No. 1

    NASA Technical Reports Server (NTRS)

    Bowen, Brent D. (Editor); Kabashkin, Igor (Editor); Lucas, Sarah (Editor); Scarpellini-Metz, Nanette (Editor)

    2005-01-01

    The mission of the Journal of Air Transportation (JA is to provide the global community immediate key resource information in all areas of air transportation. The goal of the Journal is to be recognized as the preeminent scholarly journal in the aeronautical aspects of transportation. As an international and interdisciplinary journal, the JAT will provide a forum for peer-reviewed articles in all areas of aviation and space transportation research, policy, theory, case study, practice, and issues. While maintaining a broad scope, a focal point of the journal will be in the area of aviation administration and policy.

  11. Journal of Air Transportation, Volume 11, No. 3

    NASA Technical Reports Server (NTRS)

    Bowen, Brent (Editor); Kabashkin, Igor (Editor); Fink, Mary (Editor)

    2007-01-01

    The mission of the Journal of Air Transportation (JAT) is to provide the global community immediate key resource information in all areas of air transportation. The goal of the Journal is to be recognized as the preeminent scholarly journal in the aeronautical aspects of transportation. As an international and interdisciplinary journal, the JAT will provide a forum for peer-reviewed articles in all areas of aviation and space transportation research, policy, theory, case study, practice, and issues. While maintaining a broad scope, a focal point of the journal will be in the area of aviation administration and policy

  12. Fate and transport modeling of selected chlorinated organic compounds at Operable Unit 3, U.S. Naval Air Station, Jacksonville, Florida

    USGS Publications Warehouse

    Davis, J. Hal

    2000-01-01

    Ground water contaminated by the chlorinated organic compounds trichloroethene (TCE), cis-dichloroethene (DCE), and vinyl chloride (VC) has been found in the surficial aquifer beneath the Naval Aviation Depot at the U.S. Naval Air Station, Jacksonville, Florida. The affected area is designated Operable Unit 3 (OU3) and covers 134 acres adjacent to the St. Johns River. Site-specific ground-water flow modeling was conducted at OU3 using MODFLOW, and solute-transport modeling was conducted using MT3DMS. Simulations using a low dispersivity value, which resulted in the highest concentration discharging to the St. Johns River, gave the following results. At 60 years traveltime, the highest concentration of TCE associated with the Area C plume had discharged to St. Johns River at a level that exceeded 1x103 micrograms per liter (ug/L). At 100 years traveltime, the highest concentration of TCE associated with the Area D plume had discharged to the river at a level exceeding 3x103 ug/L. At 200 years traveltime, the Area B plume had not begun discharging to the river. Simulations using a first-order decay rate half-life of 13.5 years (the slowest documented) at Area G caused the TCE to degrade before reaching the St. Johns River. If the ratio of the concentrations of TCE to cis-DCE and VC remained relatively constant, these breakdown products would not reach the river. However, the actual breakdown rates of cis-DCE and VC are unknown. Simulations were repeated using average dispersivity values with the following results. At 60 years traveltime, the highest concentration of TCE associated with the Area C plume had discharged to St. Johns River at a level exceeding 4x102 ug/L. At 100 years traveltime, the highest concentration of TCE associated with the Area D plume had discharged to the river at a level exceeding 1x103 ug/L. At 200 years traveltime, the Area B plume had not begun discharging to the river. 'Pump and treat' was simulated as a remedial alternative. The

  13. A methodology for long-range prediction of air transportation

    NASA Technical Reports Server (NTRS)

    Ayati, M. B.; English, J. M.

    1980-01-01

    A framework and methodology for long term projection of demand for aviation fuels is presented. The approach taken includes two basic components. The first was a new technique for establishing the socio-economic environment within which the future aviation industry is embedded. The concept utilized was a definition of an overall societal objective for the very long run future. Within a framework so defined, a set of scenarios by which the future will unfold are then written. These scenarios provide the determinants of the air transport industry operations and accordingly provide an assessment of future fuel requirements. The second part was the modeling of the industry in terms of an abstracted set of variables to represent the overall industry performance on a macro scale. The model was validated by testing the desired output variables from the model with historical data over the past decades.

  14. Agenda and Presentations from Circumpolar Workshop: Transport and Clean Air

    EPA Pesticide Factsheets

    EPA and its partners convened Transport and Clean Air, a Circumpolar Workshop held in December 2013. This seminar allowed leading experts to share best practices on reducing emissions of particulates and black carbon from diesel sources in the Arctic.

  15. Measuring the Air Quality and Transportation Impacts of Infill Development

    EPA Pesticide Factsheets

    This report summarizes three case studies. The analysis shows how standard forecasting tools can be modified to capture at least some of the transportation and air quality benefits of brownfield and infill development.

  16. Impact of Clean Air Regulations on Nitrogen Fate and Transport in Neuse River Basin

    EPA Science Inventory

    We investigated impacts of Clean Air Act (CAA) nitrogen emissions regulations on the fate and transport of nitrogen for two watersheds in the Neuse River Basin. The Soil and Water Assessment Tool (SWAT) and the Community Multi-Scale Air Quality (CMAQ) models were used. Two scenar...

  17. Community rotorcraft air transportation benefits and opportunities

    NASA Technical Reports Server (NTRS)

    Gilbert, G. A.; Freund, D. J.; Winick, R. M.; Cafarelli, N. J.; Hodgkins, R. F.; Vickers, T. K.

    1981-01-01

    Information about rotorcraft that will assist community planners in assessing and planning for the use of rotorcraft transportation in their communities is provided. Information useful to helicopter researchers, manufacturers, and operators concerning helicopter opportunities and benefits is also given. Three primary topics are discussed: the current status and future projections of rotorcraft technology, and the comparison of that technology with other transportation vehicles; the community benefits of promising rotorcraft transportation opportunities; and the integration and interfacing considerations between rotorcraft and other transportation vehicles. Helicopter applications in a number of business and public service fields are examined in various geographical settings.

  18. Peterson Air Force Base Transportation Plan Final Environmental Assessment

    DTIC Science & Technology

    2013-03-01

    Final Environmental Assessment Peterson Air Force Base Transportation Plan March 2013 FELSBURG H O L T & U L L E V I G Report Documentation Page Form...ABSTRACT unclassified c . THIS PAGE unclassified Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 PETERSON AIR...4-1 4.2 Off-Base Activities

  19. Joint University Program for Air Transportation Research, 1985

    NASA Technical Reports Server (NTRS)

    Morrell, Frederick R. (Compiler)

    1987-01-01

    Air transportation research being carried on at the Massachusetts Institute of Technology, Princeton University, and Ohio University is discussed. Global Positioning System experiments, Loran-C monitoring, inertial navigation, the optimization of aircraft trajectories through severe microbursts, fault tolerant flight control systems, and expert systems for air traffic control are among the topics covered.

  20. INEEL AIR MODELING PROTOCOL ext

    SciTech Connect

    C. S. Staley; M. L. Abbott; P. D. Ritter

    2004-12-01

    Various laws stemming from the Clean Air Act of 1970 and the Clean Air Act amendments of 1990 require air emissions modeling. Modeling is used to ensure that air emissions from new projects and from modifications to existing facilities do not exceed certain standards. For radionuclides, any new airborne release must be modeled to show that downwind receptors do not receive exposures exceeding the dose limits and to determine the requirements for emissions monitoring. For criteria and toxic pollutants, emissions usually must first exceed threshold values before modeling of downwind concentrations is required. This document was prepared to provide guidance for performing environmental compliance-driven air modeling of emissions from Idaho National Engineering and Environmental Laboratory facilities. This document assumes that the user has experience in air modeling and dose and risk assessment. It is not intended to be a "cookbook," nor should all recommendations herein be construed as requirements. However, there are certain procedures that are required by law, and these are pointed out. It is also important to understand that air emissions modeling is a constantly evolving process. This document should, therefore, be reviewed periodically and revised as needed. The document is divided into two parts. Part A is the protocol for radiological assessments, and Part B is for nonradiological assessments. This document is an update of and supersedes document INEEL/INT-98-00236, Rev. 0, INEEL Air Modeling Protocol. This updated document incorporates changes in some of the rules, procedures, and air modeling codes that have occurred since the protocol was first published in 1998.

  1. Test Report for Perforated Metal Air Transportable Package (PMATO) Prototype.

    SciTech Connect

    Bobbe, Jeffery G.; Pierce, Jim Dwight

    2003-06-01

    A prototype design for a plutonium air transport package capable of carrying 7.6 kg of plutonium oxide and surviving a ''worst-case'' plane crash has been developed by Sandia National Laboratories (SNL) for the Japan Nuclear Cycle Development Institute (JNC). A series of impact tests were conducted on half-scale models of this design for side, end, and comer orientations at speeds close to 282 m/s onto a target designed to simulate weathered sandstone. These tests were designed to evaluate the performance of the overpack concept and impact-limiting materials in critical impact orientations. The impact tests of the Perforated Metal Air Transportable Package (PMATP) prototypes were performed at SNL's 10,000-ft rocket sled track. This report describes test facilities calibration and environmental testing methods of the PMATP under specific test conditions. The tests were conducted according to the test plan and procedures that were written by the authors and approved by SNL management and quality assurance personnel. The result of these tests was that the half-scale PMATP survived the ''worst-case'' airplane crash conditions, and indicated that a full-scale PMATP, utilizing this overpack concept and these impact-limiting materials, would also survive these crash conditions.

  2. A state-of-the-art review of transportation systems evaluation techniques relevant to air transportation, volume 1. [urban planning and urban transportation using decision theory

    NASA Technical Reports Server (NTRS)

    Haefner, L. E.

    1975-01-01

    Mathematical and philosophical approaches are presented for evaluation and implementation of ground and air transportation systems. Basic decision processes are examined that are used for cost analyses and planning (i.e, statistical decision theory, linear and dynamic programming, optimization, game theory). The effects on the environment and the community that a transportation system may have are discussed and modelled. Algorithmic structures are examined and selected bibliographic annotations are included. Transportation dynamic models were developed. Citizen participation in transportation projects (i.e, in Maryland and Massachusetts) is discussed. The relevance of the modelling and evaluation approaches to air transportation (i.e, airport planning) is examined in a case study in St. Louis, Missouri.

  3. Transportation by Air-On the Ground

    NASA Technical Reports Server (NTRS)

    1985-01-01

    A Rolair air flotation system is a spinoff of NASA/General Motors technology developed for the Apollo Program. It allows heavy loads to be moved easily by separating the load from the ground by a thin air cushion, virtually eliminating surface friction. Rolair Systems, Inc. was formed by former General Motors engineers and has successfully employed the system for both aerospace and nonaerospace industries.

  4. Analysis of air quality management with emphasis on transportation sources

    NASA Technical Reports Server (NTRS)

    English, T. D.; Divita, E.; Lees, L.

    1980-01-01

    The current environment and practices of air quality management were examined for three regions: Denver, Phoenix, and the South Coast Air Basin of California. These regions were chosen because the majority of their air pollution emissions are related to mobile sources. The impact of auto exhaust on the air quality management process is characterized and assessed. An examination of the uncertainties in air pollutant measurements, emission inventories, meteorological parameters, atmospheric chemistry, and air quality simulation models is performed. The implications of these uncertainties to current air quality management practices is discussed. A set of corrective actions are recommended to reduce these uncertainties.

  5. Estimation of economic costs of particulate air pollution from road transport in China

    NASA Astrophysics Data System (ADS)

    Guo, X. R.; Cheng, S. Y.; Chen, D. S.; Zhou, Y.; Wang, H. Y.

    2010-09-01

    Valuation of health effects of air pollution is becoming a critical component of the performance of cost-benefit analysis of pollution control measures, which provides a basis for setting priorities for action. Beijing has focused on control of transport emission as vehicular emissions have recently become an important source of air pollution, particularly during Olympic games and Post-games. In this paper, we conducted an estimation of health effects and economic cost caused by road transport-related air pollution using an integrated assessment approach which utilizes air quality model, engineering, epidemiology, and economics. The results show that the total economic cost of health impacts due to air pollution contributed from transport in Beijing during 2004-2008 was 272, 297, 310, 323, 298 million US (mean value), respectively. The economic costs of road transport accounted for 0.52, 0.57, 0.60, 0.62, and 0.58% of annual Beijing GDP from 2004 to 2008. Average cost per vehicle and per ton of PM 10 emission from road transport can also be estimated as 106 US /number and 3584 US $ t -1, respectively. These findings illustrate that the impact of road transport contributed particulate air pollution on human health could be substantial in Beijing, whether in physical and economic terms. Therefore, some control measures to reduce transport emissions could lead to considerable economic benefit.

  6. Journal of Air Transportation, Volume 10, No. 2

    NASA Technical Reports Server (NTRS)

    Bowen, Brent (Editor); Unal, Mehmet (Editor); Gudmundsson, Sveinn Vidar (Editor); Kabashkin, Igor (Editor)

    2005-01-01

    Topics discussed include: Mitigation Alternatives for Carbon Dioxide Emissions by the Air Transport Industry in Brazil; Air Transport Regulation Under Transformation: The Case of Switzerland; An Estimation of Aircraft Emissions at Turkish Airports; Guide to the Implementation of Iso 14401 at Airports; The Impact of Constrained Future Scenarios on Aviation and Emissions; The Immediate Financial Impact of Transportation Deregulation on the Stockholders of the Airline Industry; Aviation Related Airport Marketing in an Overlapping Metropolitan Catchment Area: The Case of Milan's Three Airports; and Airport Pricing Systems and Airport Deregulation Effects on Welfare.

  7. NASA technology program for future civil air transports

    NASA Technical Reports Server (NTRS)

    Wright, H. T.

    1983-01-01

    An assessment is undertaken of the development status of technology, applicable to future civil air transport design, which is currently undergoing conceptual study or testing at NASA facilities. The NASA civil air transport effort emphasizes advanced aerodynamic computational capabilities, fuel-efficient engines, advanced turboprops, composite primary structure materials, advanced aerodynamic concepts in boundary layer laminarization and aircraft configuration, refined control, guidance and flight management systems, and the integration of all these design elements into optimal systems. Attention is given to such novel transport aircraft design concepts as forward swept wings, twin fuselages, sandwich composite structures, and swept blade propfans.

  8. The impact of changing technology on the demand for air transportation

    NASA Technical Reports Server (NTRS)

    Kneafsey, J. T.; Taneja, N. K.

    1978-01-01

    Demand models for air transportation that are sensitive to the impact of changing technology were developed. The models are responsive to potential changes in technology, and to changing economic, social, and political factors as well. In addition to anticipating the wide differences in the factors influencing the demand for long haul and short haul air travel, the models were designed to clearly distinguish among the unique features of these markets.

  9. Environic implications of lighter than air transportation

    NASA Technical Reports Server (NTRS)

    Horsbrugh, P.

    1975-01-01

    The advent of any new system of transportation must now be reviewed in the physical context and texture of the landscape. Henceforward, all transportation systems will be considered in respect of their effects upon the environment to ensure that they afford an environic asset as well as provide an economic benefit. The obligations which now confront the buoyancy engineers are emphasized so that they may respond to these ethical and environic urgencies simultaneously with routine technical development.

  10. Air Modeling - Observational Meteorological Data

    EPA Pesticide Factsheets

    Observed meteorological data for use in air quality modeling consist of physical parameters that are measured directly by instrumentation, and include temperature, dew point, wind direction, wind speed, cloud cover, cloud layer(s), ceiling height,

  11. Community Multiscale Air Quality Modeling System (CMAQ)

    EPA Pesticide Factsheets

    CMAQ is a computational tool used for air quality management. It models air pollutants including ozone, particulate matter and other air toxics to help determine optimum air quality management scenarios.

  12. Air pollution exposure: An activity pattern approach for active transportation

    NASA Astrophysics Data System (ADS)

    Adams, Matthew D.; Yiannakoulias, Nikolaos; Kanaroglou, Pavlos S.

    2016-09-01

    In this paper, we demonstrate the calculation of personal air pollution exposure during trips made by active transportation using activity patterns without personal monitors. We calculate exposure as the inhaled dose of particulate matter 2.5 μg or smaller. Two modes of active transportation are compared, and they include cycling and walking. Ambient conditions are calculated by combining mobile and stationary monitoring data in an artificial neural network space-time model. The model uses a land use regression framework and has a prediction accuracy of R2 = 0.78. Exposure is calculated at 10 m or shorter intervals during the trips using inhalation rates associated with both modes. The trips are children's routes between home and school. The average dose during morning cycling trips was 2.17 μg, during morning walking trips was 3.19 μg, during afternoon cycling trips was 2.19 μg and during afternoon walking trips was 3.23 μg. The cycling trip dose was significantly lower than the walking trip dose. The air pollution exposure during walking or cycling trips could not be strongly predicted by either the school or household ambient conditions, either individually or in combination. Multiple linear regression models regressing both the household and school ambient conditions against the dose were only able to account for, at most, six percent of the variance in the exposure. This paper demonstrates that incorporating activity patterns when calculating exposure can improve the estimate of exposure compared to its calculation from ambient conditions.

  13. Minority Transportation Expenditure Allocation Model

    SciTech Connect

    Vyas, Anant D.; Santini, Danilo J.; Marik, Sheri K.

    1993-04-12

    MITRAM (Minority TRansportation expenditure Allocation Model) can project various transportation related attributes of minority (Black and Hispanic) and majority (white) populations. The model projects vehicle ownership, vehicle miles of travel, workers, new car and on-road fleet fuel economy, amount and share of household income spent on gasoline, and household expenditures on public transportation and taxis. MITRAM predicts reactions to sustained fuel price changes for up to 10 years after the change.

  14. Stochastic models of intracellular transport

    NASA Astrophysics Data System (ADS)

    Bressloff, Paul C.; Newby, Jay M.

    2013-01-01

    The interior of a living cell is a crowded, heterogenuous, fluctuating environment. Hence, a major challenge in modeling intracellular transport is to analyze stochastic processes within complex environments. Broadly speaking, there are two basic mechanisms for intracellular transport: passive diffusion and motor-driven active transport. Diffusive transport can be formulated in terms of the motion of an overdamped Brownian particle. On the other hand, active transport requires chemical energy, usually in the form of adenosine triphosphate hydrolysis, and can be direction specific, allowing biomolecules to be transported long distances; this is particularly important in neurons due to their complex geometry. In this review a wide range of analytical methods and models of intracellular transport is presented. In the case of diffusive transport, narrow escape problems, diffusion to a small target, confined and single-file diffusion, homogenization theory, and fractional diffusion are considered. In the case of active transport, Brownian ratchets, random walk models, exclusion processes, random intermittent search processes, quasi-steady-state reduction methods, and mean-field approximations are considered. Applications include receptor trafficking, axonal transport, membrane diffusion, nuclear transport, protein-DNA interactions, virus trafficking, and the self-organization of subcellular structures.

  15. Simplified curve fits for the transport properties of equilibrium air

    NASA Technical Reports Server (NTRS)

    Srinivasan, S.; Tannehill, J. C.

    1987-01-01

    New, improved curve fits for the transport properties of equilibruim air have been developed. The curve fits are for viscosity and Prandtl number as functions of temperature and density, and viscosity and thermal conductivity as functions of internal energy and density. The curve fits were constructed using grabau-type transition functions to model the tranport properties of Peng and Pindroh. The resulting curve fits are sufficiently accurate and self-contained so that they can be readily incorporated into new or existing computational fluid dynamics codes. The range of validity of the new curve fits are temperatures up to 15,000 K densities from 10 to the -5 to 10 amagats (rho/rho sub o).

  16. Universal bursty behavior in the air transportation system

    NASA Astrophysics Data System (ADS)

    Ito, Hidetaka; Nishinari, Katsuhiro

    2015-12-01

    Social activities display bursty behavior characterized by heavy-tailed interevent time distributions. We examine the bursty behavior of airplanes' arrivals in hub airports. The analysis indicates that the air transportation system universally follows a power-law interarrival time distribution with an exponent α =2.5 and an exponential cutoff. Moreover, we investigate the mechanism of this bursty behavior by introducing a simple model to describe it. In addition, we compare the extent of the hub-and-spoke structure and the burstiness of various airline networks in the system. Remarkably, the results suggest that the hub-and-spoke network of the system and the carriers' strategy to facilitate transit are the origins of this universality.

  17. SENSITIVITY OF OZONE AND AEROSOL PREDICTIONS TO THE TRANSPORT ALGORITHMS IN THE MODELS-3 COMMUNITY MULTI-SCALE AIR QUALITY (CMAQ) MODELING SYSTEM

    EPA Science Inventory

    EPA's Models-3 CMAQ system is intended to provide a community modeling paradigm that allows continuous improvement of the one-atmosphere modeling capability in a unified fashion. CMAQ's modular design promotes incorporation of several sets of science process modules representing ...

  18. VALMET: a valley air pollution model. Final report. Revision 1

    SciTech Connect

    Whiteman, C.D.; Allwine, K.J.

    1985-04-01

    An air quality model is described for predicting air pollution concentrations in deep mountain valleys arising from nocturnal down-valley transport and diffusion of an elevated pollutant plume, and the fumigation of the plume on the valley floor and sidewalls after sunrise. Included is a technical description of the model, a discussion of the model's applications, the required model inputs, sample calculations and model outputs, and a full listing of the FORTRAN computer program. 55 refs., 27 figs., 6 tabs.

  19. Emerging Climate-data Needs in the Air Transport Sector

    NASA Astrophysics Data System (ADS)

    Thompson, T. R.

    2014-12-01

    This paper addresses the nature of climate information needed within the air-transport sector. Air transport is not a single economic sector with uniform needs for climate data: airport, airline, and air-navigation services are the principal sub-sectors, each with their own particular climate-related decision contexts. For example, airports function as fixed infrastructure that is primarily affected by probabilities of extreme events that could hamper runway/taxiway operations, interfere with worker availability, or impede travel to and from the airport by passengers. Airlines, in contrast, are more concerned with changes in atmospheric conditions (upper-air turbulence, convective weather events, etc.) that might require consideration in long-term decisions related to flight-planning processes and aircraft equipage. Air-navigation service providers have needs that are primarily concerned with assurance of safe spatial separation of aircraft via sensor data and communications links. In addition to present-day commercial air transport, we discuss what climate data may be needed for new types of air transport that may emerge in the next couple of decades. These include, for example, small aircraft provided on-demand to non-pilot travelers, high-altitude supersonic business and commercial jets, and very large numbers of un-manned aircraft. Finally, we give examples relating to key technical challenges in providing decision-relevant climate data to the air-transport sector. These include: (1) identifying what types of climate data are most relevant the different decisions facing the several segments of this industry; (2) determining decision-appropriate time horizons for forecasts of this data; and (3) coupling the uncertainties inherent in these forecasts to the decision process.

  20. 14 CFR 234.13 - Reports by air carriers on incidents involving animals during air transport.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... carrier that provides scheduled passenger air transportation shall, within 15 days of the end of the month... Consumer Protection Division a report on any incidents involving the loss, injury, or death of an...

  1. 14 CFR 234.13 - Reports by air carriers on incidents involving animals during air transport.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... carrier that provides scheduled passenger air transportation shall, within 15 days of the end of the month... Consumer Protection Division a report on any incidents involving the loss, injury, or death of an...

  2. 14 CFR 234.13 - Reports by air carriers on incidents involving animals during air transport.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... carrier that provides scheduled passenger air transportation shall, within 15 days of the end of the month... Consumer Protection Division a report on any incidents involving the loss, injury, or death of an...

  3. 14 CFR 234.13 - Reports by air carriers on incidents involving animals during air transport.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... carrier that provides scheduled passenger air transportation shall, within 15 days of the end of the month... Consumer Protection Division a report on any incidents involving the loss, injury, or death of an...

  4. 14 CFR 234.13 - Reports by air carriers on incidents involving animals during air transport.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... carrier that provides scheduled passenger air transportation shall, within 15 days of the end of the month... Consumer Protection Division a report on any incidents involving the loss, injury, or death of an...

  5. Transport of Aerosols: Regional and Global Implications for Climate, Weather, and Air Quality

    NASA Technical Reports Server (NTRS)

    Chin, Mian; Diehl, Thomas; Yu, Hongbin; Bian, Huisheng; Remer, Lorraine; Kahn, Ralph

    2008-01-01

    Long-range transport of atmospheric aerosols can have a significant impact on global climate, regional weather, and local air quality. In this study, we use a global model GOCART together with satellite data and ground-based measurements to assess the emission and transport of pollution, dust, biomass burning, and volcanic aerosols and their implications. In particular, we will show the impact of emissions and long-range transport of aerosols from major pollution and dust source regions to (1) the surface air quality, (2) the atmospheric heating rates, and (3) surface radiation change near the source and downwind regions.

  6. Air pollutant transport in a street canyon

    SciTech Connect

    Luke Chen; Hsu-Cheng Chang

    1996-12-31

    An air pollutant (CO) distribution in a typical street canyon is simulated to evaluate pedestrian exposure. In this study, we consider factors those may affect the pollutant distribution in a typical street canyon. The considered factors include aspect ratio of a street canyon, atmospheric stability, traffic load and turbulent buoyancy effect. A two-dimensional domain that includes suburban roughness and urban street canyon is considered. The factors such as atmospheric stability, traffic load and turbulent buoyancy are imposed through the associated boundary conditions. With numerical simulation, the critical aspect ration of a street canyon the includes two vortices and results in pollutant accumulation are found. The buoyant effect is found to raise the same pollutant concentration up to the position higher than the results come out from the case without buoyancy. The pedestrian exposure to the street air pollutant under various traffic loads and atmospheric stability are evaluated. This study conclude that the local building regulations that specify the building height/street width ratio will not cause significant pedestrian exposure to the street air pollution in most of traffic loads and atmospheric stability conditions.

  7. Analysis of the Chinese provincial air transportation network

    NASA Astrophysics Data System (ADS)

    Du, Wen-Bo; Liang, Bo-Yuan; Hong, Chen; Lordan, Oriol

    2017-01-01

    The air transportation system is of a great impact on the economy and globalization of a country. In this paper, we analyze the Chinese air transportation network (ATN) from a provincial perspective via the complex network framework, where all airports located in one province are abstracted as a single node and flights between two provinces are denoted by a link. The results show that the network exhibits small-world property, homogeneous structure and disassortative mixing. The variation of the flight flow within 24 h is investigated and an obvious tide phenomenon is found in the dynamics of Chinese provincial ATN for high output level of tertiary industry. Our work will offer a novel approach for understanding the characteristic of the Chinese air transportation network.

  8. Conceptual and Numerical Models for UZ Flow and Transport

    SciTech Connect

    H. Liu

    2000-03-03

    The purpose of this Analysis/Model Report (AMR) is to document the conceptual and numerical models used for modeling of unsaturated zone (UZ) fluid (water and air) flow and solute transport processes. This is in accordance with ''AMR Development Plan for U0030 Conceptual and Numerical Models for Unsaturated Zone (UZ) Flow and Transport Processes, Rev 00''. The conceptual and numerical modeling approaches described in this AMR are used for models of UZ flow and transport in fractured, unsaturated rock under ambient and thermal conditions, which are documented in separate AMRs. This AMR supports the UZ Flow and Transport Process Model Report (PMR), the Near Field Environment PMR, and the following models: Calibrated Properties Model; UZ Flow Models and Submodels; Mountain-Scale Coupled Processes Model; Thermal-Hydrologic-Chemical (THC) Seepage Model; Drift Scale Test (DST) THC Model; Seepage Model for Performance Assessment (PA); and UZ Radionuclide Transport Models.

  9. Forecasting the demand potential for STOL air transportation

    NASA Technical Reports Server (NTRS)

    Fan, S.; Horonjeff, R.; Kanafani, A.; Mogharabi, A.

    1973-01-01

    A process for predicting the potential demand for STOL aircraft was investigated to provide a conceptual framework, and an analytical methodology for estimating the STOL air transportation market. It was found that: (1) schedule frequency has the strongest effect on the traveler's choice among available routes, (2) work related business constitutes approximately 50% of total travel volume, and (3) air travel demand follows economic trends.

  10. The accelerated growth of the worldwide air transportation network

    NASA Astrophysics Data System (ADS)

    Azzam, Mark; Klingauf, Uwe; Zock, Alexander

    2013-01-01

    Mobility by means of air transportation has a critical impact on the global economy. Especially against the backdrop of further growth and an aggravation of the energy crisis, it is crucial to design a sustainable air transportation system. Current approaches focus on air traffic management. Nevertheless, also the historically evolved network offers great potential for an optimized redesign. But the understanding of its complex structure and development is limited, although modern network science supplies a great set of new methods and tools. So far studies analyzing air transportation as a complex network are based on divers and poor data, which are either merely regional or strongly bounded time-wise. As a result, the current state of research is rather inconsistent regarding topological coefficients and incomplete regarding network evolution. Therefore, we use the historical, worldwide OAG flight schedules data between 1979 and 2007 for our study. Through analyzing by far the most comprehensive data base so far, a better understanding of the network, its evolution and further implications is being provided. To our knowledge we present the first study to determine that the degree distribution of the worldwide air transportation network is non-stationary and is subject to densification and accelerated growth, respectively.

  11. Evaluation of the impact of transportation changes on air quality

    NASA Astrophysics Data System (ADS)

    Titos, G.; Lyamani, H.; Drinovec, L.; Olmo, F. J.; Močnik, G.; Alados-Arboledas, L.

    2015-08-01

    Transport regulation at local level for the abatement of air pollution has gained significant traction in the EU. In this work, we analyze the effect of different transportation changes on air quality in two similarly sized cities: Granada (Spain) and Ljubljana (Slovenia). Several air pollutants were measured at both sites before and after the implementation of the changes. In Ljubljana, a 72% reduction of local black carbon (BC), from 5.6 to 1.6 μg/m3, was observed after the restriction was implemented. In Granada, statistically significant reductions of 1.3 μg/m3 (37%) in BC and of 15 μg/m3 (33%) in PM10 concentrations were observed after the public transportation re-organization. However, the improvement observed in air quality was very local since other areas of the cities did not improve significantly. We show that closing streets to private traffic, renewal of the bus fleet and re-organization of the public transportation significantly benefit air quality.

  12. Radiant heat test of Perforated Metal Air Transportable Package (PMATP).

    SciTech Connect

    Gronewald, Patrick James; Oneto, Robert; Mould, John; Pierce, Jim Dwight

    2003-08-01

    A conceptual design for a plutonium air transport package capable of surviving a 'worst case' airplane crash has been developed by Sandia National Laboratories (SNL) for the Japan Nuclear Cycle Development Institute (JNC). A full-scale prototype, designated as the Perforated Metal Air Transport Package (PMATP) was thermally tested in the SNL Radiant Heat Test Facility. This testing, conducted on an undamaged package, simulated a regulation one-hour aviation fuel pool fire test. Finite element thermal predictions compared well with the test results. The package performed as designed, with peak containment package temperatures less than 80 C after exposure to a one-hour test in a 1000 C environment.

  13. The technical challenge of air transportation - A Government view

    NASA Technical Reports Server (NTRS)

    Roberts, L.

    1977-01-01

    This paper reviews the research and technology that must be conducted, and the facility investments that must be made, in order to assure that the United States is adequately prepared to meet the challenges that air transportation will provide in the future. The technical focal points for the next decade are reviewed in the context of the emerging pattern of air transportation needs for the remainder of the Century and the prospects for satisfying these needs are discussed. Particular attention is given to the responsibility that the Government must assume in aviation R&T and to the relationship that must be encouraged between the Government, the Industry and the University Community.

  14. Source term estimation of radioxenon released from the Fukushima Dai-ichi nuclear reactors using measured air concentrations and atmospheric transport modeling.

    PubMed

    Eslinger, P W; Biegalski, S R; Bowyer, T W; Cooper, M W; Haas, D A; Hayes, J C; Hoffman, I; Korpach, E; Yi, J; Miley, H S; Rishel, J P; Ungar, K; White, B; Woods, V T

    2014-01-01

    Systems designed to monitor airborne radionuclides released from underground nuclear explosions detected radioactive fallout across the northern hemisphere resulting from the Fukushima Dai-ichi Nuclear Power Plant accident in March 2011. Sampling data from multiple International Modeling System locations are combined with atmospheric transport modeling to estimate the magnitude and time sequence of releases of (133)Xe. Modeled dilution factors at five different detection locations were combined with 57 atmospheric concentration measurements of (133)Xe taken from March 18 to March 23 to estimate the source term. This analysis suggests that 92% of the 1.24 × 10(19) Bq of (133)Xe present in the three operating reactors at the time of the earthquake was released to the atmosphere over a 3 d period. An uncertainty analysis bounds the release estimates to 54-129% of available (133)Xe inventory.

  15. Motor transport related harmful PM2.5 and PM10: from onroad measurements to the modelling of air pollution by neural network approach on street and urban level

    NASA Astrophysics Data System (ADS)

    Lozhkina, O.; Lozhkin, V.; Nevmerzhitsky, N.; Tarkhov, D.; Vasilyev, A.

    2016-11-01

    The level of PM10 and PM2.5 concentrations in the air on seven roads in St. Petersburg, Russia, were investigated using gravimetry and nephelometry measurement techniques in 2013-2015. The effects of meteorological conditions (temperature, relative humidity, wind direction, and speed) and the intensity of traffic flows on the results of the measurements were also evaluated. On the base of the measurements, there was developed a neural network modelling approach that allowed to quantify exhaust / non-exhaust PM10 and PM 2.5 emissions and carry out numerical investigations of air pollution by transport related PM2.5 and PM10 on street and urban level in St. Petersburg.

  16. Investigation of air transportation technology at Princeton University, 1986

    NASA Technical Reports Server (NTRS)

    Stengel, Robert F.

    1988-01-01

    The Air Transportation Technology Program at Princeton proceeded along four avenues: Guidance and control strategies for penetration of microbursts and wind shear; Application of artificial intelligence in flight control systems; Computer aided control system design; and Effects of control saturation on closed loop stability and response of open loop unstable aircraft. Areas of investigation relate to guidance and control of commercial transports as well as general aviation aircraft. Interaction between the flight crew and automatic systems is a subject of prime concern.

  17. High temperature transport properties of air

    NASA Technical Reports Server (NTRS)

    Levin, E.; Partridge, Harry; Stallcop, J. R.

    1987-01-01

    A general computer code was developed to allow calculation of atom-atom and ion-atom transport collision integrals from accurate potential energy curves described by a set of discrete data points for a broad range of scattering conditions. This code is based upon semiclassical approximations that properly account for quantum mechanical behavior such as tunneling effects near a barrier maximum, resonance charge exchange, and nuclear symmetry effects. Transport collision integrals were determined for N-N, O-O, N(+)-N, and O(+)-O interactions from complete sets of accurate potential functions derived from combined experimental and ab initio structure calculations. For the O-O case, this includes results for excited states. The calculated values of the N(+)-N and O(+)-O resonance charge exchange cross section Q(ex) agree well with measurements from beam experiment that are available at high energies where the diffusion cross section Q(d) satisfies Q(d) approximately equal to 2Q(ex).

  18. Contamination transport modeling with CTSP (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Brieda, Lubos

    2016-09-01

    CTSP (Contamination Transport Simulation Program) is a simulation program for performing detailed molecular and particulate contaminant transport analyses using complex, CAD-generated geometries. CTSP concurrently traces many simulation macroparticles, allowing it to compute contaminant partial pressures. The code uses a detailed surface model that supports multiple trapped gases and a multi-component surface layer. The molecular residence time is computed by considering surface temperature and activation energies. This paper describes the implemented algorithms and demonstrates the code with several test cases. These include outgassing in a vacuum chamber, spacecraft venting, particulate transport in an air flow, and redistribution of paint flakes on an orbiting satellite. The paper is concluded by summarizing the on-going effort to parallelize the code and utilize GPUs, and to add support for electrostatic return modeling by computing space potential using Green's functions.

  19. Influence of lateral and top boundary conditions on regional air quality prediction: A multiscale study coupling regional and global chemical transport models

    NASA Astrophysics Data System (ADS)

    Tang, Youhua; Carmichael, Gregory R.; Thongboonchoo, Narisara; Chai, Tianfeng; Horowitz, Larry W.; Pierce, Robert B.; Al-Saadi, Jassim A.; Pfister, Gabriele; Vukovich, Jeffrey M.; Avery, Melody A.; Sachse, Glen W.; Ryerson, Thomas B.; Holloway, John S.; Atlas, Elliot L.; Flocke, Frank M.; Weber, Rodney J.; Huey, L. Gregory; Dibb, Jack E.; Streets, David G.; Brune, William H.

    2007-05-01

    The sensitivity of regional air quality model to various lateral and top boundary conditions is studied at 2 scales: a 60 km domain covering the whole USA and a 12 km domain over northeastern USA. Three global models (MOZART-NCAR, MOZART-GFDL and RAQMS) are used to drive the STEM-2K3 regional model with time-varied lateral and top boundary conditions (BCs). The regional simulations with different global BCs are examined using ICARTT aircraft measurements performed in the summer of 2004, and the simulations are shown to be sensitive to the boundary conditions from the global models, especially for relatively long-lived species, like CO and O3. Differences in the mean CO concentrations from three different global-model boundary conditions are as large as 40 ppbv, and the effects of the BCs on CO are shown to be important throughout the troposphere, even near surface. Top boundary conditions show strong effect on O3 predictions above 4 km. Over certain model grids, the model's sensitivity to BCs is found to depend not only on the distance from the domain's top and lateral boundaries, downwind/upwind situation, but also on regional emissions and species properties. The near-surface prediction over polluted area is usually not as sensitive to the variation of BCs, but to the magnitude of their background concentrations. We also test the sensitivity of model to temporal and spatial variations of the BCs by comparing the simulations with time-varied BCs to the corresponding simulations with time-mean and profile BCs. Removing the time variation of BCs leads to a significant bias on the variation prediction and sometime causes the bias in predicted mean values. The effect of model resolution on the BC sensitivity is also studied.

  20. Air-quality-model update

    SciTech Connect

    Penner, J.E.; Walton, J.J.

    1982-01-15

    The Livermore Regional Air Quality Model (LIRAQ) has been updated and improved. This report describes the changes that have been made in chemistry, species treatment, and boundary conditions. The results of smog chamber simulations that were used to verify the chemistry as well as simulations of the entire air quality model for two prototype days in the Bay Area are reported. The results for the prototype day simulations are preliminary due to the need for improvement in meteorology fields, but they show the dependence and sensitivity of high hour ozone to changes in selected boundary and initial conditions.

  1. Arrow 227: Air transport system design simulation

    NASA Technical Reports Server (NTRS)

    Bontempi, Michael; Bose, Dave; Brophy, Georgeann; Cashin, Timothy; Kanarios, Michael; Ryan, Steve; Peterson, Timothy

    1992-01-01

    The Arrow 227 is a student-designed commercial transport for use in a overnight package delivery network. The major goal of the concept was to provide the delivery service with the greatest potential return on investment. The design objectives of the Arrow 227 were based on three parameters; production cost, payload weight, and aerodynamic efficiency. Low production cost helps to reduce initial investment. Increased payload weight allows for a decrease in flight cycles and, therefore, less fuel consumption than an aircraft carrying less payload weight and requiring more flight cycles. In addition, fewer flight cycles will allow a fleet to last longer. Finally, increased aerodynamic efficiency in the form of high L/D will decrease fuel consumption.

  2. Theoretical Transport Model for Tokamaks

    NASA Astrophysics Data System (ADS)

    Ghanem, Elsayed Mohammad

    In the present thesis work a theoretical transport model is suggested to study the anomalous transport of plasma particles and energy across the axisymmetric equilibrium toroidal magnetic flux surfaces in tokamaks. The model suggests a linear combination of two transport mechanisms; drift waves, which dominate the transport in the core region, and resistive ballooning modes, which dominate the transport in the edge region. The resulting unified model has been used in a predictive transport code to simulate the plasma transport in different tokamak experiments operating in both the ohmic heating phase and the low confinement mode (L-mode). For ohmic plasma, the model was used to study the saturation of energy confinement time at high plasma density. The effect of the resistive ballooning mode as a possible cause of the saturation phenomena has been investigated together with the effect of the ion temperature gradient mode. For the low confinement mode plasmas, the study has emphasized on using the model to obtain a scaling law for the energy confinement time with the various plasma parameters compared to the scaling laws that are derived based on fitting the experimental data.

  3. Groundwater flow and transport modeling

    USGS Publications Warehouse

    Konikow, L.F.; Mercer, J.W.

    1988-01-01

    Deterministic, distributed-parameter, numerical simulation models for analyzing groundwater flow and transport problems have come to be used almost routinely during the past decade. A review of the theoretical basis and practical use of groundwater flow and solute transport models is used to illustrate the state-of-the-art. Because of errors and uncertainty in defining model parameters, models must be calibrated to obtain a best estimate of the parameters. For flow modeling, data generally are sufficient to allow calibration. For solute-transport modeling, lack of data not only limits calibration, but also causes uncertainty in process description. Where data are available, model reliability should be assessed on the basis of sensitivity tests and measures of goodness-of-fit. Some of these concepts are demonstrated by using two case histories. ?? 1988.

  4. Assessing Impact of Aerosol Intercontinental Transport on Regional Air Quality and Climate: What Satellites Can Help

    NASA Technical Reports Server (NTRS)

    Yu, Hongbin

    2011-01-01

    Mounting evidence for intercontinental transport of aerosols suggests that aerosols from a region could significantly affect climate and air quality in downwind regions and continents. Current assessment of these impacts for the most part has been based on global model simulations that show large variability. The aerosol intercontinental transport and its influence on air quality and climate involve many processes at local, regional, and intercontinental scales. There is a pressing need to establish modeling systems that bridge the wide range of scales. The modeling systems need to be evaluated and constrained by observations, including satellite measurements. Columnar loadings of dust and combustion aerosols can be derived from the MODIS and MISR measurements of total aerosol optical depth and particle size and shape information. Characteristic transport heights of dust and combustion aerosols can be determined from the CALIPSO lidar and AIRS measurements. CALIPSO liar and OMI UV technique also have a unique capability of detecting aerosols above clouds, which could offer some insights into aerosol lofting processes and the importance of above-cloud transport pathway. In this presentation, I will discuss our efforts of integrating these satellite measurements and models to assess the significance of intercontinental transport of dust and combustion aerosols on regional air quality and climate.

  5. Investigation of air transportation technology at Princeton University

    NASA Technical Reports Server (NTRS)

    Stengel, R. F.

    1983-01-01

    The Air Transportation Technology Program at Princeton University, a program emphasizing graduate and undergraduate student research, proceeded along six avenues during the past year: investigation of fuel use characteristics of general aviation aircraft, experimentation with an ultrasonic altimeter, single pilot instrument flight, application of fiber optics in flight control systems, voice recognition inputs for navigation/communication receiver tuning, and computer aided aircraft design.

  6. Airline Transport Pilot-Airplane (Air Carrier) Written Test Guide.

    ERIC Educational Resources Information Center

    Federal Aviation Administration (DOT), Washington, DC. Flight Standards Service.

    Presented is information useful to applicants who are preparing for the Airline Transport Pilot-Airplane (Air Carrier) Written Test. The guide describes the basic aeronautical knowledge and associated requirements for certification, as well as information on source material, instructions for taking the official test, and questions that are…

  7. Contact Information for EPA's Office of Transportation and Air Quality

    EPA Pesticide Factsheets

    You will find an EPA employee by name or by topic of interest, also, you will know who to contact if you want to find a specific transportation and air quality document, importing a vehicle to the US, and other frequently asked questions.

  8. Joint University Program for Air Transportation Research, 1982

    NASA Technical Reports Server (NTRS)

    1983-01-01

    A summary of the research on air transportation is addressed including navigation; guidance, control and display concepts; and hardware, with special emphasis on applications to general aviation aircraft. Completed works and status reports are presented also included are annotated bibliographies of all published research sponsored on these grants since 1972.

  9. Stratospheric Transport Times From Observations and Models

    NASA Astrophysics Data System (ADS)

    Hoor, P. M.; Lelieveld, J.; Boenisch, H.; Joeckel, P.; Steil, B.; Bruehl, C.; Strahan, S.

    2007-12-01

    Transport time scales in the stratosphere are crucial to understand and calculate the effects of chemical active species on stratospheric chemistry. In general CO2 or SF6 have been used to calculate mean ages of air in the stratosphere, whereas shorter lived trace gases like CO are used to investigate cross tropopause transport and mixing on short time-scales close to the tropopause. Besides mean ages and their assocated mean trace gas mixing ratios at a given point in the atmosphere other quantities of the trace gas distributions can be used to constrain stratospheric transport times, such as variability and slope. In particular the younger part of the age spectrum needs to be constrained since it determines the extent to which shorter lived compounds can be transported into the stratosphere. We investigate transport times in the stratosphere based on observations of CO, N2O and CO2 and test a new approach to deduce transport times. For that purpose we compare observations from the ER-2 and other platforms. The approach is applied to global models (ECHAM5/MESSy, Combo GMI) to identify barriers as well as regions of rapid mixing and transport.

  10. 48 CFR 47.403-2 - Air transport agreements between the United States and foreign governments.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Air transport agreements....-Flag Carriers 47.403-2 Air transport agreements between the United States and foreign governments... attend, the use of a foreign-flag air carrier that provides transportation under an air...

  11. 14 CFR Sec. 19-5 - Air transport traffic and capacity elements.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Air transport traffic and capacity elements... AIR CARRIERS Operating Statistics Classifications Sec. 19-5 Air transport traffic and capacity... reported as applicable to specified air transport traffic and capacity elements. (b) These reported...

  12. 14 CFR 19-5 - Air transport traffic and capacity elements.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Air transport traffic and capacity elements... CERTIFICATED AIR CARRIERS Operating Statistics Classifications Sec. 19-5 Air transport traffic and capacity... reported as applicable to specified air transport traffic and capacity elements. (b) These reported...

  13. Statistical Analysis of the Impacts of Regional Transportation on the Air Quality in Beijing

    NASA Astrophysics Data System (ADS)

    Huang, Zhongwen; Zhang, Huiling; Tong, Lei; Xiao, Hang

    2016-04-01

    From October to December 2015, Beijing-Tianjin-Hebei (BTH) region had experienced several severe haze events. In order to assess the effects of the regional transportation on the air quality in Beijing, the air monitoring data (PM2.5, SO2, NO2 and CO) from that period published by Chinese National Environmental Monitoring Center (CNEMC) was collected and analyzed with various statistical models. The cities within BTH area were clustered into three groups according to the geographical conditions, while the air pollutant concentrations of cities within a group sharing similar variation trends. The Granger causality test results indicate that significant causal relationships exist between the air pollutant data of Beijing and its surrounding cities (Baoding, Chengde, Tianjin and Zhangjiakou) for the reference period. Then, linear regression models were constructed to capture the interdependency among the multiple time series. It shows that the observed air pollutant concentrations in Beijing were well consistent with the model-fitted results. More importantly, further analysis suggests that the air pollutants in Beijing were strongly affected by regional transportation, as the local sources only contributed 17.88%, 27.12%, 14.63% and 31.36% of PM2.5, SO2, NO2 and CO concentrations, respectively. And the major foreign source for Beijing was from Southwest (Baoding) direction, account for more than 42% of all these air pollutants. Thus, by combining various statistical models, it may not only be able to quickly predict the air qualities of any cities on a regional scale, but also to evaluate the local and regional source contributions for a particular city. Key words: regional transportation, air pollution, Granger causality test, statistical models

  14. Acoustophoretic contactless transport and handling of matter in air.

    PubMed

    Foresti, Daniele; Nabavi, Majid; Klingauf, Mirko; Ferrari, Aldo; Poulikakos, Dimos

    2013-07-30

    Levitation and controlled motion of matter in air have a wealth of potential applications ranging from materials processing to biochemistry and pharmaceuticals. We present a unique acoustophoretic concept for the contactless transport and handling of matter in air. Spatiotemporal modulation of the levitation acoustic field allows continuous planar transport and processing of multiple objects, from near-spherical (volume of 0.1-10 μL) to wire-like, without being limited by the acoustic wavelength. The independence of the handling principle from special material properties (magnetic, optical, or electrical) is illustrated with a wide palette of application experiments, such as contactless droplet coalescence and mixing, solid-liquid encapsulation, absorption, dissolution, and DNA transfection. More than a century after the pioneering work of Lord Rayleigh on acoustic radiation pressure, a path-breaking concept is proposed to harvest the significant benefits of acoustic levitation in air.

  15. Acoustophoretic contactless transport and handling of matter in air

    PubMed Central

    Foresti, Daniele; Nabavi, Majid; Klingauf, Mirko; Ferrari, Aldo; Poulikakos, Dimos

    2013-01-01

    Levitation and controlled motion of matter in air have a wealth of potential applications ranging from materials processing to biochemistry and pharmaceuticals. We present a unique acoustophoretic concept for the contactless transport and handling of matter in air. Spatiotemporal modulation of the levitation acoustic field allows continuous planar transport and processing of multiple objects, from near-spherical (volume of 0.1–10 μL) to wire-like, without being limited by the acoustic wavelength. The independence of the handling principle from special material properties (magnetic, optical, or electrical) is illustrated with a wide palette of application experiments, such as contactless droplet coalescence and mixing, solid–liquid encapsulation, absorption, dissolution, and DNA transfection. More than a century after the pioneering work of Lord Rayleigh on acoustic radiation pressure, a path-breaking concept is proposed to harvest the significant benefits of acoustic levitation in air. PMID:23858454

  16. Technological change and productivity growth in the air transport industry

    NASA Technical Reports Server (NTRS)

    Rosenberg, N.; Thompson, A.; Belsley, S. E.

    1978-01-01

    The progress of the civil air transport industry in the United States was examined in the light of a proposal of Enos who, after examining the growth of the petroleum industry, divided that phenomenon into two phases, the alpha and the beta; that is, the invention, first development and production, and the improvement phase. The civil air transport industry developed along similar lines with the technological progress coming in waves; each wave encompassing several new technological advances while retaining the best of the old ones. At the same time the productivity of the transport aircraft as expressed by the product of the aircraft velocity and the passenger capacity increased sufficiently to allow the direct operating cost in cents per passenger mile to continually decrease with each successive aircraft development.

  17. 19 CFR 122.117 - Requirements for transit air cargo transport.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 19 Customs Duties 1 2011-04-01 2011-04-01 false Requirements for transit air cargo transport. 122...; DEPARTMENT OF THE TREASURY AIR COMMERCE REGULATIONS Transit Air Cargo Manifest (TACM) Procedures § 122.117 Requirements for transit air cargo transport. (a) Transportation—(1) Port to port. Transit air cargo may...

  18. 19 CFR 122.117 - Requirements for transit air cargo transport.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 19 Customs Duties 1 2012-04-01 2012-04-01 false Requirements for transit air cargo transport. 122...; DEPARTMENT OF THE TREASURY AIR COMMERCE REGULATIONS Transit Air Cargo Manifest (TACM) Procedures § 122.117 Requirements for transit air cargo transport. (a) Transportation—(1) Port to port. Transit air cargo may...

  19. 19 CFR 122.117 - Requirements for transit air cargo transport.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 19 Customs Duties 1 2013-04-01 2013-04-01 false Requirements for transit air cargo transport. 122...; DEPARTMENT OF THE TREASURY AIR COMMERCE REGULATIONS Transit Air Cargo Manifest (TACM) Procedures § 122.117 Requirements for transit air cargo transport. (a) Transportation—(1) Port to port. Transit air cargo may...

  20. 19 CFR 122.117 - Requirements for transit air cargo transport.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Requirements for transit air cargo transport. 122...; DEPARTMENT OF THE TREASURY AIR COMMERCE REGULATIONS Transit Air Cargo Manifest (TACM) Procedures § 122.117 Requirements for transit air cargo transport. (a) Transportation—(1) Port to port. Transit air cargo may...

  1. 19 CFR 122.117 - Requirements for transit air cargo transport.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 19 Customs Duties 1 2014-04-01 2014-04-01 false Requirements for transit air cargo transport. 122...; DEPARTMENT OF THE TREASURY AIR COMMERCE REGULATIONS Transit Air Cargo Manifest (TACM) Procedures § 122.117 Requirements for transit air cargo transport. (a) Transportation—(1) Port to port. Transit air cargo may...

  2. Source Term Estimation of Radioxenon Released from the Fukushima Dai-ichi Nuclear Reactors Using Measured Air Concentrations and Atmospheric Transport Modeling

    SciTech Connect

    Eslinger, Paul W.; Biegalski, S.; Bowyer, Ted W.; Cooper, Matthew W.; Haas, Derek A.; Hayes, James C.; Hoffman, Ian; Korpach, E.; Yi, Jing; Miley, Harry S.; Rishel, Jeremy P.; Ungar, R. Kurt; White, Brian; Woods, Vincent T.

    2014-01-01

    Systems designed to monitor airborne radionuclides released from underground nuclear explosions detected radioactive fallout from the Fukushima Daiichi nuclear accident in March 2011. Atmospheric transport modeling (ATM) of plumes of noble gases and particulates were performed soon after the accident to determine plausible detection locations of any radioactive releases to the atmosphere. We combine sampling data from multiple International Modeling System (IMS) locations in a new way to estimate the magnitude and time sequence of the releases. Dilution factors from the modeled plume at five different detection locations were combined with 57 atmospheric concentration measurements of 133-Xe taken from March 18 to March 23 to estimate the source term. This approach estimates that 59% of the 1.24×1019 Bq of 133-Xe present in the reactors at the time of the earthquake was released to the atmosphere over a three day period. Source term estimates from combinations of detection sites have lower spread than estimates based on measurements at single detection sites. Sensitivity cases based on data from four or more detection locations bound the source term between 35% and 255% of available xenon inventory.

  3. VALMET-A valley air pollution model

    SciTech Connect

    Whiteman, C.D.; Allwine, K.J.

    1983-09-01

    Following a thorough analysis of meteorological data obtained from deep valleys of western Colorado, a modular air-pollution model has been developed to simulate the transport and diffusion of pollutants released from an elevated point source in a well-defined mountain valley during the nighttime and morning transition periods. This initial version of the model, named VALMET, operates on a valley cross section at an arbitrary distance down-valley from a continuous point source. The model has been constructed to include parameterizations of the major physical processes that act to disperse pollution during these time periods. The model has not been fully evaluated. Further testing, evaluations, and development of the model are needed. Priorities for further development and testing are provided.

  4. The Air Quality Model Evaluation International Initiative ...

    EPA Pesticide Factsheets

    This presentation provides an overview of the Air Quality Model Evaluation International Initiative (AQMEII). It contains a synopsis of the three phases of AQMEII, including objectives, logistics, and timelines. It also provides a number of examples of analyses conducted through AQMEII with a particular focus on past and future analyses of deposition. The National Exposure Research Laboratory (NERL) Computational Exposure Division (CED) develops and evaluates data, decision-support tools, and models to be applied to media-specific or receptor-specific problem areas. CED uses modeling-based approaches to characterize exposures, evaluate fate and transport, and support environmental diagnostics/forensics with input from multiple data sources. It also develops media- and receptor-specific models, process models, and decision support tools for use both within and outside of EPA.

  5. Journal of Air Transportation, Volume 9, No. 2. Volume 9, No. 2

    NASA Technical Reports Server (NTRS)

    Bowen, Brent (Editor); Kabashkin, Igor (Editor); Gudmundsson, Sveinn Vidar (Editor); Scarpellini, Nanette (Editor)

    2004-01-01

    The following articles from the "Journal of Air Transportation" were processed: Future Requirements and Concepts for Cabins of Blended Wing Body Configurations:A Scenario Approach; Future Scenarios for the European Airline Industry: A Marketing-Based Perspective; An Application of the Methodology for Assessment of the Sustainability of the Air Transport System; Modeling the Effect of Enlarged Seating Room on Passenger Preferences of Domestic Airlines in Taiwan; Developing a Fleet Standardization Index for Airline Pricing; and Future Airport Capacity Utilization in Germany: Peaked Congestion and/or Idle Capacity).

  6. What should ``damaged`` mean in air transport of fissile packages

    SciTech Connect

    Luna, R.E.; Falci, F.P.; Blackman, D.

    1995-12-31

    It is likely that the ongoing process to produce the 1996 version of the IAEA Regulation for the Safe Transport of Radioactive Materials, IAEA Safety Series 6(SS 6) will result in a more stringent package qualification standard for air transport of large quantities of radioactive materials (RAM) than is included in the 1990 version. During the process to define the scope of the new requirements there was extensive discussion of their impact on, and application to, fissile material package qualification criteria. Since fissile materials are shipped in a variety of packagings ranging from exempt to Type B, each packaging of each type must be evaluated for its ability to maintain subcriticality both alone and in arrays and in both damaged and undamaged condition. In the 1990 version of SS 6 ``damaged`` means the condition of a package after it had undergone the ``tests for demonstrating the ability to withstand accident conditions in transport,`` i.e., Type B qualification tests. These tests conditions are typical of severe accidents in surface modes, but are less severe than air mode qualification test environments to be applied to Type C packages. As a result, questions arose about the need for a corresponding change in the 1996 SS 6 to define ``damaged`` to include the Type C test regime for criticality evaluations of fissile packages in air transport.

  7. Vehicle expectations in air transportation for the year 2000

    NASA Technical Reports Server (NTRS)

    Hearth, D. P.

    1980-01-01

    This paper is intended to provide an overview of the air transportation system for the year 2000 in terms of vehicle expectations. Emphasis is placed on civil air transportation with the time period approached from the standpoint of evolutionary changes for the near term and also with the assumption of more revolutionary changes for the far term. The view along the evolutionary path begins with a historical review of airline market growth and the impact that technologies have had on airplane designs. Projections of the life expectancy of existing, derivative, and new airplanes are examined in terms of their productivity and fuel efficiency in view of the present and projected fuel usage and availability. The factors influencing airline growth are outlined and some views on whether another new generation of subsonic airplanes are in the offing are given along with an assessment of the economic viability of an advanced commercial supersonic transport in terms of its higher speed, higher productivity, and higher fuel usage. With regard to revolutionary changes, major technology breakthroughs are assumed to occur at a specified date. As an example, the impact of a dramatic reduction in skin friction drag is examined in terms of its effect on the airplane configuration, its propulsion systems, it projected fuel usage, and the air transportation system in which it must operate.

  8. Next Generation Transport Phenomenology Model

    NASA Technical Reports Server (NTRS)

    Strickland, Douglas J.; Knight, Harold; Evans, J. Scott

    2004-01-01

    This report describes the progress made in Quarter 3 of Contract Year 3 on the development of Aeronomy Phenomenology Modeling Tool (APMT), an open-source, component-based, client-server architecture for distributed modeling, analysis, and simulation activities focused on electron and photon transport for general atmospheres. In the past quarter, column emission rate computations were implemented in Java, preexisting Fortran programs for computing synthetic spectra were embedded into APMT through Java wrappers, and work began on a web-based user interface for setting input parameters and running the photoelectron and auroral electron transport models.

  9. Air transportation energy consumption - Yesterday, today, and tomorrow

    NASA Technical Reports Server (NTRS)

    Mascy, A. C.; Williams, L. J.

    1975-01-01

    The energy consumption by aviation is reviewed and projections of its growth are discussed. Forecasts of domestic passenger demand are presented, and the effect of restricted fuel supply and increased fuel prices is considered. The most promising sources for aircraft fuels, their availability and cost, and possible alternative fuels are reviewed. The energy consumption by various air and surface transportation modes is identified and compared on typical portal-to-portal trips. A measure of the indirect energy consumed by ground and air modes is defined. Historical trends in aircraft energy intensities are presented and the potential fuel savings with new technologies are discussed.

  10. Transportation Costs as a Consideration in Air Force Contracts.

    DTIC Science & Technology

    1979-03-10

    46556 _______________________ II. CONTROLLING OFFICE NAME AND ADDR ESS 12. REPORT DATE .4 - . 79Mar 10 AIR _~~~~~~~~~~ ØJSIN~~S RESEARC~1 MANN3~ 4~NT...these costs be understood and controlled . Many transportation decisions are made by the con trac tor under F.O.B. destination contracts versus those...imperative therefore , that these costs be understood and controlled . Like many business organiza tions , the United States Air Force faces problems of

  11. Investigation of air transportation technology at Princeton University, 1984

    NASA Technical Reports Server (NTRS)

    Stengel, Robert F.

    1987-01-01

    The Air Transportation Technology Program at Princeton University, a program emphasizing graduate and undergraduate student research, proceeded along four avenues during 1984: (1) guidance and control strategies for penetration of microbursts and wind shear; (2) application of artificial intelligence in flight control systems; (3) effects of control saturation on closed loop stability; and (4) response of open loop unstable aircraft. Areas of investigation relate to guidance and control of commercial transports as well as to general aviation aircraft. Interaction between the flight crew and automatic systems is a subject of principle concern. These areas of investigation are briefly discussed.

  12. Mathematical Modeling of Kidney Transport

    PubMed Central

    Layton, Anita T.

    2013-01-01

    In addition to metabolic waste and toxin excretion, the kidney also plays an indispensable role in regulating the balance of water, electrolytes, nitrogen, and acid-base. In this review, we describe representative mathematical models that have been developed to better understand kidney physiology and pathophysiology, including the regulation of glomerular filtration, the regulation of renal blood flow by means of the tubuloglomerular feedback mechanisms and of the myogenic mechanism, the urine concentrating mechanism, epithelial transport, and regulation of renal oxygen transport. We discuss the extent to which these modeling efforts have expanded our understanding of renal function in both health and disease. PMID:23852667

  13. Investigation of air transportation technology at Princeton University, 1981

    NASA Technical Reports Server (NTRS)

    Stengel, R. F.

    1982-01-01

    A summary of the air transportation technology program is presented. The following topics were examined: (1) fuel use characteristics of general aviation aircraft; (2) dead-reckoning concept incorporating a fluidic rate sensor; (3) experimentation with an ultrasonic altimeter; (4) development of laser-based collision avoidance systems; (5) flight path reconstruction from sequential DME data; (6) application of fiber optics in flight control systems; and (7) voice recognition inputs for navigation/communication receiver tuning.

  14. Joint University Program for Air Transportation Research, 1989-1990

    NASA Technical Reports Server (NTRS)

    Morrell, Frederick R. (Compiler)

    1990-01-01

    Research conducted during the academic year 1989-90 under the NASA/FAA sponsored Joint University Program for Air Transportation research is discussed. Completed works, status reports and annotated bibliographies are presented for research topics, which include navigation, guidance and control theory and practice, aircraft performance, human factors, and expert systems concepts applied to airport operations. An overview of the year's activities for each university is also presented.

  15. Investigation of air transportation technology at Ohio University, 1984

    NASA Technical Reports Server (NTRS)

    Mcfarland, Richard H.

    1987-01-01

    The operational development of Loran-C for enroute navigation and nonprecision approaches was studied, and is only one of the many projects funded by the Joint University Program for Air Transportation at Ohio University. Other projects included work on the DATAC data bus monitor, global positioning system test bed receiver development, fiber optic data bus application in general aviation aircraft, and advanced remote monitoring techniques.

  16. Joint University Program for Air Transportation Research, 1986

    NASA Technical Reports Server (NTRS)

    Morrell, Frederick R. (Compiler)

    1988-01-01

    The research conducted under the NASA/FAA sponsored Joint University Program for Air Transportation Research is summarized. The Joint University Program is a coordinated set of three grants sponsored by NASA and the FAA, one each with the Mass. Inst. of Tech., Ohio Univ., and Princeton Univ. Completed works, status reports, and bibliographies are presented for research topics, which include computer science, guidance and control theory and practice, aircraft performance, flight dynamics, and applied experimental psychology. An overview of activities is presented.

  17. Journal of Air Transportation, Volume 11, No. 1

    NASA Technical Reports Server (NTRS)

    Bowen, Brent (Editor); Kabashkin, Igor (Editor); Fink, Mary (Editor)

    2006-01-01

    Topics covered include: Analysis of System-wide Investment in the National Airspace System: A Portfolio Analytical Framework and an Example; Regional Air Transport in Europe: The Potential Role of the Civil Tiltrotor in Reducing Airside Congestion; The Development of Jomo Kenyatta International Airport as a Regional Aviation Hub; Corporate Social Responsibility in Aviation; The Competitive Effects of Airline Mergers and Acquisitions: More Capital Market Evidence; and The Competitive Position of Hub Airports in the Transatlantic Market.

  18. Potential Impact of Clean Air Act Regulations on Nitrogen Fate and Transport in the Neuse River Basin: a Modeling Investigation Using CMAQ and SWAT

    EPA Science Inventory

    There has been extensive analysis of Clean Air Act Amendment (CAAA) regulation impacts to changes in atmospheric nitrogen deposition; however, few studies have focused on watershed nitrogen transfer particularly regarding long-term predictions. In this study, we investigated impa...

  19. Development of an Air Transport Type A Fissile Package

    SciTech Connect

    Blanton, P.; Ebert, K.

    2011-07-13

    This paper presents the summary of testing by the Savannah River National Laboratory (SRNL) to support development of a light weight (<140 lbs) air transport qualified Type A Fissile Packaging. The package design incorporates features and materials specifically designed to minimize packaging weight. The light weight package is being designed to provide confinement to the contents when subjected to the normal and hypothetical conditions required of an air transportable Type A Fissile radioactive material shipping package. The objective of these tests was to provide design input to the final design for the LORX Type A Fissile Air Transport Packaging when subjected to the performance requirements of the drop, crush and puncture probe test of 10CFR71. The post test evaluation of the prototype packages indicates that all of the tested designs would satisfactorily confine the content within the packaging. The differences in the performance of the prototypes varied significantly depending on the core materials and their relative densities. Information gathered from these tests is being used to develop the final design for the Department of Homeland Security.

  20. Evaluation of the Community Multiscale Air Quality model version 5.1

    EPA Science Inventory

    The Community Multiscale Air Quality model is a state-of-the-science air quality model that simulates the emission, transport and fate of numerous air pollutants, including ozone and particulate matter. The Atmospheric Modeling and Analysis Division (AMAD) of the U.S. Environment...

  1. Synthesized voice approach callouts for air transport operations

    NASA Technical Reports Server (NTRS)

    Simpson, C. A.

    1980-01-01

    A flight simulation experiment was performed to determine the effectiveness of synthesized voice approach callouts for air transport operations. Flight deck data was first collected on scheduled air carrier operations to describe existing pilot-not-flying callout procedures in the flight context and to document the types and amounts of other auditory cockpit information during different types of air carrier operations. A flight simulation scenario for a wide-body jet transport airline training simulator was developed in collaboration with a major U.S. air carrier and flown by three-man crews of qualified line pilots as part of their normally scheduled recurrent training. Each crew flew half their approaches using the experimental synthesized voice approach callout system (SYNCALL) and the other half using the company pilot-not-flying approach callout procedures (PNF). Airspeed and sink rate performance was better with the SYNCALL system than with the PNF system for non-precision approaches. For the one-engine approach, for which SYNCALL made inappropriate deviation callouts, airspeed performance was worse with SYNCALL than with PNF. Reliability of normal altitude approach callouts was comparable for PNF on the line and in the simulator and for SYNCALL in the simulator.

  2. Advanced Air Transportation Technologies Project, Final Document Collection

    NASA Technical Reports Server (NTRS)

    Mogford, Richard H.; Wold, Sheryl (Editor)

    2008-01-01

    This CD ROM contains a compilation of the final documents of the Advanced Air Transportation Technologies (AAIT) project, which was an eight-year (1996 to 2004), $400M project managed by the Airspace Systems Program office, which was part of the Aeronautics Research Mission Directorate at NASA Headquarters. AAIT focused on developing advanced automation tools and air traffic management concepts that would help improve the efficiency of the National Airspace System, while maintaining or enhancing safety. The documents contained in the CD are final reports on AAIT tasks that serve to document the project's accomplishments over its eight-year term. Documents include information on: Advanced Air Transportation Technologies, Autonomous Operations Planner, Collaborative Arrival Planner, Distributed Air/Ground Traffic Management Concept Elements 5, 6, & 11, Direct-To, Direct-To Technology Transfer, Expedite Departure Path, En Route Data Exchange, Final Approach Spacing Tool - (Active and Passive), Multi-Center Traffic Management Advisor, Multi Center Traffic Management Advisor Technology Transfer, Surface Movement Advisor, Surface Management System, Surface Management System Technology Transfer and Traffic Flow Management Research & Development.

  3. 14 CFR 206.4 - Exemption of air carriers for military transportation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Exemption of air carriers for military transportation. 206.4 Section 206.4 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION... AUTHORIZATIONS AND EXEMPTIONS § 206.4 Exemption of air carriers for military transportation. Air...

  4. 14 CFR 206.4 - Exemption of air carriers for military transportation.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Exemption of air carriers for military transportation. 206.4 Section 206.4 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION... AUTHORIZATIONS AND EXEMPTIONS § 206.4 Exemption of air carriers for military transportation. Air...

  5. 14 CFR 206.4 - Exemption of air carriers for military transportation.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Exemption of air carriers for military transportation. 206.4 Section 206.4 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION... AUTHORIZATIONS AND EXEMPTIONS § 206.4 Exemption of air carriers for military transportation. Air...

  6. The Conference Proceedings of the 2003 Air Transport Research Society (ATRS) World Conference, Volume 5

    NASA Technical Reports Server (NTRS)

    Bowen, Brent (Editor); Gudmundsson, Sveinn (Editor); Oum, Tae (Editor)

    2003-01-01

    The UNO Aviation Institute Monograph Series began in 1994 as a key component of the education outreach and information transfer missions of the Aviation Institute and the NASA Nebraska Space Grant & EPSCoR Programs. The series is an outlet for aviation materials to be indexed and disseminated through an efficient medium. Publications are welcome in all aspects of aviation. Publication formats may include, but are not limited to, conference proceedings, bibliographies, research reports, manuals, technical reports, and other documents that should be archived and indexed for future reference by the aviation and world wide communities. The Conference proceedings of the 2003 Air Transport Research Society (ATRS) world conference, volume 5 is presented. The topics include: 1) The Temporal Configuration of Airline Networks in Europe; 2) Determination and Applications of Environmental Costs at Different Sized Airports-Aircraft Noise and Engine Emissions; 3) Cost Effective Measures to Reduce CO2 Emissions in the Air Freight Sector; 4) An Assessment of the Sustainability of Air Transport System: Quantification of Indicators; 5) Regulation, Competition and Network Evolution in Aviation; 6) Regulation in the Air: Price and Frequency Cap; 7) Industry Consolidation and Future Airline Network Structures in Europe; 8) Application of Core Theory to the U.S. Airline Industry; 9) Air Freight Transshipment Route Choice Analysis; 10) A Fuzzy Approach of the Competition on Air Transport Market; and 11) Developing Passenger Demand Models for International Aviation from/to Egypt: A Case Study of Cairo Airport and Egyptair.

  7. Removing volatile contaminants from the unsaturated zone by inducing advective air-phase transport

    USGS Publications Warehouse

    Baehr, A.L.; Hoag, G.E.; Marley, M.C.

    1989-01-01

    Organic liquids inadvertently spilled and then distributed in the unsaturated zone can pose a long-term threat to ground water. Many of these substances have significant volatility, and thereby establish a premise for contaminant removal from the unsaturated zone by inducing advective air-phase transport with wells screened in the unsaturated zone. In order to focus attention on the rates of mass transfer from liquid to vapour phases, sand columns were partially saturated with gasoline and vented under steady air-flow conditions. The ability of an equilibrium-based transport model to predict the hydrocarbon vapor flux from the columns implies an efficient rate of local phase transfer for reasonably high air-phase velocities. Thus the success of venting remediations will depend primarily on the ability to induce an air-flow field in a heterogeneous unsaturated zone that will intersect the distributed contaminant. To analyze this aspect of the technique, a mathematical model was developed to predict radially symmetric air flow induced by venting from a single well. This model allows for in-situ determinations of air-phase permeability, which is the fundamental design parameter, and for the analysis of the limitations of a single well design. A successful application of the technique at a site once contaminated by gasoline supports the optimism derived from the experimental and modeliing phases of this study, and illustrates the well construction and field methods used to document the volatile contaminant recovery. ?? 1989.

  8. Air transport of infants in Newfoundland and Labrador.

    PubMed Central

    Johnson, M. A.; Owers, J.; Horwood, P.

    1978-01-01

    Air transportation of 33 infants in small unpressurized aircraft over long distances is described. Twenty-six of the infants were transported more than 320 km in environmental temperatures varying from -35 to +21 degrees C. A commercially available incubator was used. Although more than half the infants had a rectal temperature within the normal range at the time of arrival at hospital, 12 infants had rectal temperatures above 37.5 degrees C as a result of efforts to diminish heat loss. Adequate oxygenation of infants at 3000 m in unpressurized aircraft can be difficult. Cold and vibration can affect equipment, and at high altitudes the readings from oxygen analysers may not be true. The use of an expanded transport team, which includes experienced nonmedical personnel, is particularly important in these cases. Images FIG. 1 FIG. 3 PMID:679112

  9. Mathematical model of one-man air revitalization system

    NASA Technical Reports Server (NTRS)

    1976-01-01

    A mathematical model was developed for simulating the steady state performance in electrochemical CO2 concentrators which utilize (NMe4)2 CO3 (aq.) electrolyte. This electrolyte, which accommodates a wide range of air relative humidity, is most suitable for one-man air revitalization systems. The model is based on the solution of coupled nonlinear ordinary differential equations derived from mass transport and rate equations for the processes which take place in the cell. The boundary conditions are obtained by solving the mass and energy transport equations. A shooting method is used to solve the differential equations.

  10. An Air MEDEVAC Asset Dispatching and Prioritized Casualty Transporting Model for Military Medical Evacuation Systems with Distinguishable Medical Treatment Facilities and Errors in Triage

    DTIC Science & Technology

    2014-02-13

    allows for batch arrival of casualties to the system. The MDP is solved with a value iteration algorithm. The optimal policy is compared to three...casualties to the system. The MDP is solved with a value iteration algorithm. The optimal policy is compared to three heuristic casualty transport policies...transport decisions are interrelated and more accurate information is collected at the scene. This paper formulates a Markov decision process ( MDP

  11. The ASAC Air Carrier Investment Model (Third Generation)

    NASA Technical Reports Server (NTRS)

    Wingrove, Earl R., III; Gaier, Eric M.; Santmire, Tara E.

    1998-01-01

    To meet its objective of assisting the U.S. aviation industry with the technological challenges of the future, NASA must identify research areas that have the greatest potential for improving the operation of the air transportation system. To accomplish this, NASA is building an Aviation System Analysis Capability (ASAC). The ASAC differs from previous NASA modeling efforts in that the economic behavior of buyers and sellers in the air transportation and aviation industries is central to its conception. To link the economics of flight with the technology of flight, ASAC requires a parametrically based model with extensions that link airline operations and investments in aircraft with aircraft characteristics. This model also must provide a mechanism for incorporating air travel demand and profitability factors into the airlines' investment decisions. Finally, the model must be flexible and capable of being incorporated into a wide-ranging suite of economic and technical models flat are envisioned for ASAC.

  12. Journal of Air Transportation, Volume 12, No. 1

    NASA Technical Reports Server (NTRS)

    Bowers, Brent D. (Editor); Kabashkin, Igor (Editor)

    2007-01-01

    Topics discussed include: a) Data Mining Methods Applied to Flight Operations Quality Assurance Data: A Comparison to Standard Statistical Methods; b) Financial Comparisons across Different Business Models in the Canadian Airline Industry; c) Carving a Niche for the "No-Frills" Carrier, Air Arabia, in Oil-Rich Skies; d) Situational Leadership in Air Traffic Control; and e) The Very Light Jet Arrives: Stakeholders and Their Perceptions.

  13. A portfolio evaluation framework for air transportation improvement projects

    NASA Astrophysics Data System (ADS)

    Baik, Hyeoncheol

    This thesis explores the application of portfolio theory to the Air Transportation System (ATS) improvement. The ATS relies on complexly related resources and different stakeholder groups. Moreover, demand for air travel is significantly increasing relative to capacity of air transportation. In this environment, improving the ATS is challenging. Many projects, which are defined as technologies or initiatives, for improvement have been proposed and some have been demonstrated in practice. However, there is no clear understanding of how well these projects work in different conditions nor of how they interact with each other or with existing systems. These limitations make it difficult to develop good project combinations, or portfolios that maximize improvement. To help address this gap, a framework for identifying good portfolios is proposed. The framework can be applied to individual projects or portfolios of projects. Projects or portfolios are evaluated using four different groups of factors (effectiveness, time-to-implement, scope of applicability, and stakeholder impacts). Portfolios are also evaluated in terms of interaction-determining factors (prerequisites, co-requisites, limiting factors, and amplifying factors) because, while a given project might work well in isolation, interdependencies between projects or with existing systems could result in lower overall performance in combination. Ways to communicate a portfolio to decision makers are also introduced. The framework is unique because (1) it allows using a variety of available data, and (2) it covers diverse benefit metrics. For demonstrating the framework, an application to ground delay management projects serves as a case study. The portfolio evaluation approach introduced in this thesis can aid decision makers and researchers at universities and aviation agencies such as Federal Aviation Administration (FAA), National Aeronautics and Space Administration (NASA), and Department of Defense (DoD), in

  14. Thermodynamic and Transport Properties of Real Air Plasma in Wide Range of Temperature and Pressure

    NASA Astrophysics Data System (ADS)

    Wang, Chunlin; Wu, Yi; Chen, Zhexin; Yang, Fei; Feng, Ying; Rong, Mingzhe; Zhang, Hantian

    2016-07-01

    Air plasma has been widely applied in industrial manufacture. In this paper, both dry and humid air plasmas' thermodynamic and transport properties are calculated in temperature 300-100000 K and pressure 0.1-100 atm. To build a more precise model of real air plasma, over 70 species are considered for composition. Two different methods, the Gibbs free energy minimization method and the mass action law method, are used to determinate the composition of the air plasma in a different temperature range. For the transport coefficients, the simplified Chapman-Enskog method developed by Devoto has been applied using the most recent collision integrals. It is found that the presence of CO2 has almost no effect on the properties of air plasma. The influence of H2O can be ignored except in low pressure air plasma, in which the saturated vapor pressure is relatively high. The results will serve as credible inputs for computational simulation of air plasma. supported by the National Key Basic Research Program of China (973 Program)(No. 2015CB251002), National Natural Science Foundation of China (Nos. 51521065, 51577145), the Science and Technology Project Funds of the Grid State Corporation (SGTYHT/13-JS-177), the Fundamental Research Funds for the Central Universities, and State Grid Corporation Project (GY71-14-004)

  15. WASP TRANSPORT MODELING AND WASP ECOLOGICAL MODELING

    EPA Science Inventory

    A combination of lectures, demonstrations, and hands-on excercises will be used to introduce pollutant transport modeling with the U.S. EPA's general water quality model, WASP (Water Quality Analysis Simulation Program). WASP features include a user-friendly Windows-based interfa...

  16. Transportation Secure Data Center: Real-World Data for Environmental and Air Quality Analysis (Fact Sheet)

    SciTech Connect

    Not Available

    2013-01-01

    The National Renewable Energy Laboratory (NREL) and the U.S. Department of Transportation (DOT) have launched the free, web-based Transportation Secure Data Center (TSDC). The TSDC (www.nrel.gov/tsdc) preserves respondent anonymity while making vital transportation data available to a broad group of users through secure, online access. The TSDC database provides free-of-charge web-based access to valuable transportation data that can be used for: Emissions and air pollution modeling, Vehicle energy and power analysis, Climate change impact studies, Alternative fuel station planning, and Validating transportation data from other sources. The TSDC's two levels of access make composite data available with simple online registration, and allow researchers to use detailed spatial data after completing a straight forward application process.

  17. Transboundary health impacts of transported global air pollution and international trade.

    PubMed

    Zhang, Qiang; Jiang, Xujia; Tong, Dan; Davis, Steven J; Zhao, Hongyan; Geng, Guannan; Feng, Tong; Zheng, Bo; Lu, Zifeng; Streets, David G; Ni, Ruijing; Brauer, Michael; van Donkelaar, Aaron; Martin, Randall V; Huo, Hong; Liu, Zhu; Pan, Da; Kan, Haidong; Yan, Yingying; Lin, Jintai; He, Kebin; Guan, Dabo

    2017-03-29

    Millions of people die every year from diseases caused by exposure to outdoor air pollution. Some studies have estimated premature mortality related to local sources of air pollution, but local air quality can also be affected by atmospheric transport of pollution from distant sources. International trade is contributing to the globalization of emission and pollution as a result of the production of goods (and their associated emissions) in one region for consumption in another region. The effects of international trade on air pollutant emissions, air quality and health have been investigated regionally, but a combined, global assessment of the health impacts related to international trade and the transport of atmospheric air pollution is lacking. Here we combine four global models to estimate premature mortality caused by fine particulate matter (PM2.5) pollution as a result of atmospheric transport and the production and consumption of goods and services in different world regions. We find that, of the 3.45 million premature deaths related to PM2.5 pollution in 2007 worldwide, about 12 per cent (411,100 deaths) were related to air pollutants emitted in a region of the world other than that in which the death occurred, and about 22 per cent (762,400 deaths) were associated with goods and services produced in one region for consumption in another. For example, PM2.5 pollution produced in China in 2007 is linked to more than 64,800 premature deaths in regions other than China, including more than 3,100 premature deaths in western Europe and the USA; on the other hand, consumption in western Europe and the USA is linked to more than 108,600 premature deaths in China. Our results reveal that the transboundary health impacts of PM2.5 pollution associated with international trade are greater than those associated with long-distance atmospheric pollutant transport.

  18. Dynamic airspace configuration algorithms for next generation air transportation system

    NASA Astrophysics Data System (ADS)

    Wei, Jian

    The National Airspace System (NAS) is under great pressure to safely and efficiently handle the record-high air traffic volume nowadays, and will face even greater challenge to keep pace with the steady increase of future air travel demand, since the air travel demand is projected to increase to two to three times the current level by 2025. The inefficiency of traffic flow management initiatives causes severe airspace congestion and frequent flight delays, which cost billions of economic losses every year. To address the increasingly severe airspace congestion and delays, the Next Generation Air Transportation System (NextGen) is proposed to transform the current static and rigid radar based system to a dynamic and flexible satellite based system. New operational concepts such as Dynamic Airspace Configuration (DAC) have been under development to allow more flexibility required to mitigate the demand-capacity imbalances in order to increase the throughput of the entire NAS. In this dissertation, we address the DAC problem in the en route and terminal airspace under the framework of NextGen. We develop a series of algorithms to facilitate the implementation of innovative concepts relevant with DAC in both the en route and terminal airspace. We also develop a performance evaluation framework for comprehensive benefit analyses on different aspects of future sector design algorithms. First, we complete a graph based sectorization algorithm for DAC in the en route airspace, which models the underlying air route network with a weighted graph, converts the sectorization problem into the graph partition problem, partitions the weighted graph with an iterative spectral bipartition method, and constructs the sectors from the partitioned graph. The algorithm uses a graph model to accurately capture the complex traffic patterns of the real flights, and generates sectors with high efficiency while evenly distributing the workload among the generated sectors. We further improve

  19. Transportation Sector Model of the National Energy Modeling System. Volume 2 -- Appendices: Part 1

    SciTech Connect

    1998-01-01

    This volume contains input data and parameters used in the model of the transportation sector of the National Energy Modeling System. The list of Transportation Sector Model variables includes parameters for the following: Light duty vehicle modules (fuel economy, regional sales, alternative fuel vehicles); Light duty vehicle stock modules; Light duty vehicle fleet module; Air travel module (demand model and fleet efficiency model); Freight transport module; Miscellaneous energy demand module; and Transportation emissions module. Also included in these appendices are: Light duty vehicle market classes; Maximum light duty vehicle market penetration parameters; Aircraft fleet efficiency model adjustment factors; and List of expected aircraft technology improvements.

  20. Modeling axisymmetric flow and transport

    USGS Publications Warehouse

    Langevin, C.D.

    2008-01-01

    Unmodified versions of common computer programs such as MODFLOW, MT3DMS, and SEAWAT that use Cartesian geometry can accurately simulate axially symmetric ground water flow and solute transport. Axisymmetric flow and transport are simulated by adjusting several input parameters to account for the increase in flow area with radial distance from the injection or extraction well. Logarithmic weighting of interblock transmissivity, a standard option in MODFLOW, can be used for axisymmetric models to represent the linear change in hydraulic conductance within a single finite-difference cell. Results from three test problems (ground water extraction, an aquifer push-pull test, and upconing of saline water into an extraction well) show good agreement with analytical solutions or with results from other numerical models designed specifically to simulate the axisymmetric geometry. Axisymmetric models are not commonly used but can offer an efficient alternative to full three-dimensional models, provided the assumption of axial symmetry can be justified. For the upconing problem, the axisymmetric model was more than 1000 times faster than an equivalent three-dimensional model. Computational gains with the axisymmetric models may be useful for quickly determining appropriate levels of grid resolution for three-dimensional models and for estimating aquifer parameters from field tests.

  1. Modeling axisymmetric flow and transport.

    PubMed

    Langevin, Christian D

    2008-01-01

    Unmodified versions of common computer programs such as MODFLOW, MT3DMS, and SEAWAT that use Cartesian geometry can accurately simulate axially symmetric ground water flow and solute transport. Axisymmetric flow and transport are simulated by adjusting several input parameters to account for the increase in flow area with radial distance from the injection or extraction well. Logarithmic weighting of interblock transmissivity, a standard option in MODFLOW, can be used for axisymmetric models to represent the linear change in hydraulic conductance within a single finite-difference cell. Results from three test problems (ground water extraction, an aquifer push-pull test, and upconing of saline water into an extraction well) show good agreement with analytical solutions or with results from other numerical models designed specifically to simulate the axisymmetric geometry. Axisymmetric models are not commonly used but can offer an efficient alternative to full three-dimensional models, provided the assumption of axial symmetry can be justified. For the upconing problem, the axisymmetric model was more than 1000 times faster than an equivalent three-dimensional model. Computational gains with the axisymmetric models may be useful for quickly determining appropriate levels of grid resolution for three-dimensional models and for estimating aquifer parameters from field tests.

  2. Modeling Radionuclide Transport in Clays

    SciTech Connect

    Zheng, Liange; Li, Lianchong; Rutqvist, Jonny; Liu, Hui -Hai; Birkholzer, Jens

    2012-05-01

    tests (e.g. Garcia-Gutierrez et al. 2006, Soler et al. 2008, van Loon et al. 2004, Wu et al. 2009) and numerical modeling (de Windt et al. 2003; 2006), the effects of THMC processes on radionuclide transport are not fully investigated. The objectives of the research activity documented in this report are to improve a modeling capability for coupled THMC processes and to use it to evaluate the THMC impacts on radionuclide transport. This research activity addresses several key Features, Events and Processes (FEPs), including FEP 2.2.08, Hydrologic Processes, FEP 2.2.07, Mechanical Processes and FEP 2.2.09, Chemical Process— Transport, by studying near-field coupled THMC processes in clay/shale repositories and their impacts on radionuclide transport. This report documents the progress that has been made in FY12. Section 2 discusses the development of THMC modeling capability. Section 3 reports modeling results of THMC impacts on radionuclide transport. Planned work for the remaining months of FY12 and proposed work for FY13 are presented in Section 4.

  3. Evaluation of the Community Multi-scale Air Quality Model Version 5.2

    EPA Science Inventory

    The Community Multiscale Air Quality (CMAQ) model is a state-of-the-science air quality model that simulates the emission, transport and fate of numerous air pollutants, including ozone and particulate matter. The Computational Exposure Division (CED) of the U.S. Environmental Pr...

  4. Evaluation of the Community Multi-scale Air Quality (CMAQ) Model Version 5.2

    EPA Science Inventory

    The Community Multiscale Air Quality (CMAQ) model is a state-of-the-science air quality model that simulates the emission, transport and fate of numerous air pollutants, including ozone and particulate matter. The Computational Exposure Division (CED) of the U.S. Environmental Pr...

  5. Evaluation of the Community Multi-scale Air Quality (CMAQ) Model Version 5.1

    EPA Science Inventory

    The Community Multiscale Air Quality (CMAQ) model is a state-of-the-science air quality model that simulates the emission, transport and fate of numerous air pollutants, including ozone and particulate matter. The Computational Exposure Division (CED) of the U.S. Environmental Pr...

  6. Overview and Evaluation of the Community Multiscale Air Quality Model Version 5.2

    EPA Science Inventory

    The Community Multiscale Air Quality (CMAQ) model is a state-of-the-science air quality model that simulates the emission, transport and fate of numerous air pollutants, including ozone and particulate matter. The Computational Exposure Division (CED) of the U.S. Environmental Pr...

  7. Implementation of Satellite Techniques in the Air Transport

    NASA Astrophysics Data System (ADS)

    Fellner, Andrzej; Jafernik, Henryk

    2016-06-01

    The article shows process of the implementation satellite systems in Polish aviation which contributed to accomplishment Performance-Based Navigation (PBN) concept. Since 1991 authors have introduced Satellite Navigation Equipment in Polish Air Forces. The studies and researches provide to the Polish Air Force alternative approaches, modernize their navigation and landing systems and achieve compatibility with systems of the North Atlantic Treaty Organization (NATO) and International Civil Aviation Organization (ICAO). Acquired experience, conducted military tests and obtained results enabled to take up work scientifically - research in the environment of the civil aviation. Therefore in 2008 there has been launched cooperation with Polish Air Navigation Services Agency (PANSA). Thanks to cooperation, there have been compiled and fulfilled three fundamental international projects: EGNOS APV MIELEC (EGNOS Introduction in European Eastern Region - APV Mielec), HEDGE (Helicopters Deploy GNSS in Europe), SHERPA (Support ad-Hoc to Eastern Region Pre-operational in GNSS). The successful completion of these projects enabled implementation 21 procedures of the RNAV GNSS final approach at Polish airports, contributing to the implementation of PBN in Poland as well as ICAO resolution A37-11. Results of conducted research which served for the implementation of satellite techniques in the air transport constitute the meaning of this material.

  8. Air pollution modeling and its application III

    SciTech Connect

    De Wispelaere, C.

    1984-01-01

    This book focuses on the Lagrangian modeling of air pollution. Modeling cooling tower and power plant plumes, modeling the dispersion of heavy gases, remote sensing as a tool for air pollution modeling, dispersion modeling including photochemistry, and the evaluation of model performances in practical applications are discussed. Specific topics considered include dispersion in the convective boundary layer, the application of personal computers to Lagrangian modeling, the dynamic interaction of cooling tower and stack plumes, the diffusion of heavy gases, correlation spectrometry as a tool for mesoscale air pollution modeling, Doppler acoustic sounding, tetroon flights, photochemical air quality simulation modeling, acid deposition of photochemical oxidation products, atmospheric diffusion modeling, applications of an integral plume rise model, and the estimation of diffuse hydrocarbon leakages from petrochemical factories. This volume constitutes the proceedings of the Thirteenth International Technical Meeting on Air Pollution Modeling and Its Application held in France in 1982.

  9. The Conference Proceedings of the 1998 Air Transport Research Group (ATRG) of the WCTR Society. Volume 1

    NASA Technical Reports Server (NTRS)

    Oum, Tae Hoon (Editor); Bowen, Brent D. (Editor)

    1998-01-01

    This report (Volume 1) is comprised of 5 sessions of the Air Transport Research Group (ATRG) Conference held in Antwerp, Belgium, July 1998. The sessions contain 3-4 papers (presentations) each. The session numbers and their respective headings are: (1) Airline alliances; (2) Airline Competition and Market Structure; (4) Liberalization, Open Skies, and Policy Issues; (5) Yield Management and Other Models; and (11) Air Traffic Control (ATC) and Air Navigational Systems (ANS).

  10. Transport and transformation of air pollutants from Israel's coastal area

    NASA Astrophysics Data System (ADS)

    Luria, M.; Almog, H.; Peleg, M.

    The occasional high ozone levels measured in Jerusalem could not be attributed solely to local sources such as vehicular traffic or industry. A satellite monitoring station was set up outside the city limits to explore the possibility of transport and transformation of air pollutants from the highly populated and industrialized coastal area of Israel to the inland hilly region. This study revealed that the high ozone levels were always associated with a parallel increase of SO 2 and that power plants and/or vehicles operating in the coastal region are a major source for the nitrogen oxides which undergo photochemical transformation to form ozone during inland travel of the air parcel under conditions of intense sunlight.

  11. Air transportation in the California Corridor of 2010

    NASA Technical Reports Server (NTRS)

    Cameron, M.; Mahaffy, K.; Yanagi, G.; Lechmanski, L.; Riddle, T.; Howard, K.; Chan, C.; Gorman, M.; Bauer, B.

    1989-01-01

    The topic of the 1988-1989 NASA/USRA Advanced Design Project at California Polytechnic State University, San Luis Obispo, was the development of an air transportation system to meet the needs of the California Corridor for the year 2010. As aircraft design is taught by two instructors having different philosophies about the teaching process, the two classes took different approaches to address the problem. The first part of this summary (California Air Transit System) represents the work done by the students of Professor A. E. Andreoli, who followed a systems approach, emphasizing the determination of the proper mission. The second part of the summary (Four Aircraft to Service the California Corridor) contains the four aircraft designed by Dr. D. R. Sandlin's class based on specifications determined from work done in previous years.

  12. Joint University Program for Air Transportation Research, 1991-1992

    NASA Technical Reports Server (NTRS)

    Morrell, Frederick R. (Compiler)

    1993-01-01

    This report summarizes the research conducted during the academic year 1991-1992 under the FAA/NASA sponsored Joint University Program for Air Transportation Research. The year end review was held at Ohio University, Athens, Ohio, June 18-19, 1992. The Joint University Program is a coordinated set of three grants sponsored by the Federal Aviation Administration and NASA Langley Research Center, one each with the Massachusetts Institute of Technology (NGL-22-009-640), Ohio University (NGR-36-009-017), and Princeton University (NGL-31-001-252). Completed works, status reports, and annotated bibliographies are presented for research topics, which include navigation, guidance and control theory and practice, intelligent flight control, flight dynamics, human factors, and air traffic control processes. An overview of the year's activities for each university is also presented.

  13. Joint University Program for Air Transportation Research, 1984

    NASA Technical Reports Server (NTRS)

    Morrell, Frederick R. (Compiler)

    1987-01-01

    The research conducted during 1984 under the NASA/FAA sponsored Joint University Program for Air Transportation Research is summarized. The Joint University Program is a coordinated set of three grants sponsored by NASA Langley Research Center and the Federal Aviation Administration, one each with the Massachusetts Institute of Technology, Ohio University, and Princeton University. Completed works, status reports, and bibliographies are presented for research topics, which include navigation, guidance, control and display concepts. An overview of the year's activities for each of the schools is also presented.

  14. Joint University Program for Air Transportation Research, 1988-1989

    NASA Technical Reports Server (NTRS)

    Morrell, Frederick R. (Compiler)

    1990-01-01

    The research conducted during 1988 to 1989 under the NASA/FAA-sponsored Joint University Program for Air Transportation Research is summarized. The Joint University Program is a coordinated set of three grants sponsored by NASA Langley Research Center and the Federal Aviation Administration, one each with the Massachusetts Institute of Technology, Ohio University, and Princeton University. Completed works, status reports, and annotated bibliographies are presented for research topics, which include computer science, guidance and control theory and practice, aircraft performance, flight dynamics, and applied experimental psychology. An overview of the year's activities for each university is also presented.

  15. SBIR Advanced Technologies in Aviation and Air Transportation System 2016

    NASA Technical Reports Server (NTRS)

    Nguyen, Hung D.; Steele, Gynelle C.; Kaszeta, Richard W.; Gold, Calman; Corke, Thomas C.; McGowan, Ryan; Matlis, Eric; Eichenlaub, Jesse; Davis, Joshua T.; Shah, Parthiv N.

    2017-01-01

    This report is intended to provide a broad knowledge of various topics associated with NASA's Aeronautics Research Mission Directorate (ARMD), with particular interest on the NASA SBIR contracts awarded from 2011-2012 executed by small companies. The content of this report focuses on the high-quality, cutting-edge research that will lead to revolutionary concepts, technologies, and capabilities that enable radical change to both the airspace system and the aircraft that fly within it, facilitating a safer, more environmentally friendly, and more efficient air transportation system.

  16. Journal of Air Transportation, Volume 10, No. 3

    NASA Technical Reports Server (NTRS)

    Bowen, Brent D. (Editor); Kabashkin, Igor (Editor)

    2005-01-01

    The following topics are discussed: The Effects of Safety Information on Aeronautical Decision Making; Design, Development, and Validation of an Interactive Multimedia Training Simulator for Responding to Air Transportation Bomb Threats; Discovering the Regulatory Considerations of the Federal Aviation Administration: Interviewing the Aviation Rulemaking Advisory Committee; How to Control Airline Routes from the Supply Side: The Case of TAP; An Attempt to Measure the Traffic Impact of Airline Alliances; and Study Results on Knowledge Requirements for Entry-level Airport Operations and Management Personnel.

  17. Joint University Program for Air Transportation Research, 1983

    NASA Technical Reports Server (NTRS)

    Morrell, Frederick R. (Compiler)

    1987-01-01

    The research conducted during 1983 under the NASA/FAA sponsored Joint University Program for Air Transportation Research is summarized. The material was presented at a conference held at the Federal Aviation Administration Technical Center, Altantic City, New Jersey, December 16, 1983. The Joint University Program is a coordinated set of three grants sponsored by NASA Langley Research Center and the Federal Aviation Administration, one each with the Massachusetts Institute of Technology, Ohio University, and Princeton University. Completed works, status reports, and bibliographies are presented for research topics, which include navigation, guidance, control, and display concepts. An overview of the year's activities for each of the universities is also presented.

  18. Joint University Program for Air Transportation Research, 1987

    NASA Technical Reports Server (NTRS)

    Morrell, Frederick R. (Compiler)

    1989-01-01

    The research conducted during 1987 under the NASA/FAA sponsored Joint University Program for Air Transportation Research is summarized. The Joint University Program is a coordinated set of 3 grants sponsored by NASA-Langley and the FAA, one each with the MIT, Ohio Univ., and Princeton Univ. Completed works, status reports, and annotated bibliographies are presented for research topics, which include computer science, guidance and control theory and practice, aircraft performance, flight dynamics, and applied experimental psychology. An overview of the year's activities for each university is also presented.

  19. Investigation of air transportation technology at Princeton University, 1985

    NASA Technical Reports Server (NTRS)

    Stengel, Robert F.

    1987-01-01

    The program proceeded along five avenues during 1985. Guidance and control strategies for penetration of microbursts and wind shear, application of artificial intelligence in flight control and air traffic control systems, the use of voice recognition in the cockpit, the effects of control saturation on closed-loop stability and response of open-loop unstable aircraft, and computer aided control system design are among the topics briefly considered. Areas of investigation relate to guidance and control of commercial transports as well as general aviation aircraft. Interaction between the flight crew and automatic systems is the subject of principal concern.

  20. High-Speed Civil Transport Will Revolutionize Air Travel

    NASA Technical Reports Server (NTRS)

    1998-01-01

    NASA is developing advanced technologies that will allow industry to build a high-speed civil transport that will revolutionize overseas air travel. The technology challenges include developing low-cost materials and structural concepts as well as supersonic engines that can meet stringent noise and emissions standards. NASA's goal is to provide enabling technologies that will reduce the travel time to the Far East by 50 percent within 25 years, and do so at today's subsonic ticket prices. This research is part of NASA's Aeronautics and Space Transportation Technology (ASTT) Enterprise's strategy to sustain U.S. leadership in aeronautics and space. The Enterprise has set bold goals that are grouped into Three Pillars: Global Civil Aviation, Revolutionary Technology Leaps and Access to Space.

  1. Sustainable development of urban transport systems and human exposure to air pollution.

    PubMed

    Colvile, R N; Kaur, S; Britter, R; Robins, A; Bell, M C; Shallcross, D; Belcher, S E

    2004-12-01

    DAPPLE (Dispersion of Air Pollution and Penetration into the Local Environment, http://www.dapple.org.uk) is a major research project that will provide the understanding necessary to assess the sustainability of urban road transport in terms of exposure to traffic-related air pollution as an alternative to current indicators based on emissions, roadside, or far-from-road air pollution levels. The methodology is described, which combines on-street and laboratory measurement with modelling of the movement of air, vehicles, and vehicle exhaust emissions. The relationship between this kind of assessment and more realistic indicators of sustainability is discussed. The value of large-scale interdisciplinary research in this area is thus demonstrated.

  2. Two-phase flow and transport in the air cathode of proton exchange membrane fuel cells

    NASA Astrophysics Data System (ADS)

    Wang, Z. H.; Wang, C. Y.; Chen, K. S.

    Two-phase flow and transport of reactants and products in the air cathode of proton exchange membrane (PEM) fuel cells is studied analytically and numerically. Single- and two-phase regimes of water distribution and transport are classified by a threshold current density corresponding to first appearance of liquid water at the membrane/cathode interface. When the cell operates above the threshold current density, liquid water appears and a two-phase zone forms within the porous cathode. A two-phase, multicomponent mixture model in conjunction with a finite-volume-based computational fluid dynamics (CFD) technique is applied to simulate the cathode operation in this regime. The model is able to handle the situation where a single-phase region co-exists with a two-phase zone in the air cathode. For the first time, the polarization curve as well as water and oxygen concentration distributions encompassing both single- and two-phase regimes of the air cathode are presented. Capillary action is found to be the dominant mechanism for water transport inside the two-phase zone of the hydrophilic structure. The liquid water saturation within the cathode is predicted to reach 6.3% at 1.4 A cm -2 for dry inlet air.

  3. Effects of trans-Eurasian transport of air pollutants on surface ozone concentrations over Western China

    NASA Astrophysics Data System (ADS)

    Li, Xiaoyuan; Liu, Junfeng; Mauzerall, Denise L.; Emmons, Louisa K.; Walters, Stacy; Horowitz, Larry W.; Tao, Shu

    2014-11-01

    Due to a lack of industrialization in Western China, surface air there was, until recently, believed to be relatively unpolluted. However, recent measurements and modeling studies have found high levels of ozone (O3) there. Based on the state-of-the-science global chemical transport model MOZART-4, we identify the origin, pathway, and mechanism of trans-Eurasian transport of air pollutants to Western China in 2000. MOZART-4 generally simulates well the observed surface O3 over inland areas of China. Simulations find surface ozone concentrations over Western China on average to be about 10 ppbv higher than Eastern China. Using sensitivity studies, we find that anthropogenic emissions from all Eurasian regions except China contribute 10-15 ppbv surface O3 over Western China, superimposed upon a 35-40 ppbv natural background. Transport from European anthropogenic sources to Northwestern China results in 2-6 ppbv O3 enhancements in spring and summer. Indian anthropogenic sources strongly influence O3 over the Tibetan Plateau during the summer monsoon. Transport of O3 originating from emissions in the Middle East occasionally reach Western China and increase surface ozone there by about 1-4 ppbv. These influences are of similar magnitude as trans-Pacific and transatlantic transport of O3 and its precursors, indicating the significance of trans-Eurasian ozone transport in hemispheric transport of air pollution. Our study further indicates that mitigation of anthropogenic emissions from Europe, the Indian subcontinent, and the Middle East could benefit public health and agricultural productivity in Western China.

  4. Development and application of air quality models at the US ...

    EPA Pesticide Factsheets

    Overview of the development and application of air quality models at the U.S. EPA, particularly focused on the development and application of the Community Multiscale Air Quality (CMAQ) model developed within the Computation Exposure Division (CED) of the National Exposure Research Laboratory (NERL). This presentation will provide a simple overview of air quality model development and application geared toward a non-technical student audience. The National Exposure Research Laboratory (NERL) Computational Exposure Division (CED) develops and evaluates data, decision-support tools, and models to be applied to media-specific or receptor-specific problem areas. CED uses modeling-based approaches to characterize exposures, evaluate fate and transport, and support environmental diagnostics/forensics with input from multiple data sources. It also develops media- and receptor-specific models, process models, and decision support tools for use both within and outside of EPA.

  5. Modeling oil weathering and transport in sea ice.

    PubMed

    Afenyo, Mawuli; Khan, Faisal; Veitch, Brian; Yang, Ming

    2016-06-15

    This paper presents a model of oil weathering and transport in sea ice. It contains a model formulation and scenario simulation to test the proposed model. The model formulation is based on state-of-the-art models for individual weathering and transport processes. The approach incorporates the dependency of weathering and transport processes on each other, as well as their simultaneous occurrence after an oil spill in sea ice. The model is calibrated with available experimental data. The experimental data and model prediction show close agreement. A sensitivity analysis is conducted to determine the most sensitive parameters in the model. The model is useful for contingency planning of a potential oil spill in sea ice. It is suitable for coupling with a level IV fugacity model, to estimate the concentration and persistence of hydrocarbons in air, ice, water and sediments for risk assessment purposes.

  6. Developing of a New Atmospheric Ionizing Radiation (AIR) Model

    NASA Technical Reports Server (NTRS)

    Clem, John M.; deAngelis, Giovanni; Goldhagen, Paul; Wilson, John W.

    2003-01-01

    As a result of the research leading to the 1998 AIR workshop and the subsequent analysis, the neutron issues posed by Foelsche et al. and further analyzed by Hajnal have been adequately resolved. We are now engaged in developing a new atmospheric ionizing radiation (AIR) model for use in epidemiological studies and air transportation safety assessment. A team was formed to examine a promising code using the basic FLUKA software but with modifications to allow multiple charged ion breakup effects. A limited dataset of the ER-2 measurements and other cosmic ray data will be used to evaluate the use of this code.

  7. Thermal analysis of Perforated Metal Air Transportable Package (PMATP) prototype.

    SciTech Connect

    Oneto, Robert; Levine, Howard; Mould, John; Pierce, Jim Dwight

    2003-08-01

    Sandia National Laboratories (SNL) has designed a crash-resistant container, the Perforated Metal Air Transportable Package (PMATP), capable of surviving a worst-case plane crash, including both impact and subsequent fire, for the air transport of plutonium. This report presents thermal analyses of the full-scale PMATP in its undamaged (pre-test) condition and in bounding post-accident states. The goal of these thermal simulations was to evaluate the performance of the package in a worst-case post-crash fire. The full-scale package is approximately 1.6 m long by 0.8 m diameter. The thermal analyses were performed with the FLEX finite element code. This analysis clearly predicts that the PMATP provides acceptable thermal response characteristics, both for the post-accident fire of a one-hour duration and the after-fire heat-soak condition. All predicted temperatures for the primary containment vessel are well within design limits for safety.

  8. 14 CFR 1300.3 - Supplementary regulations of the Air Transportation Stabilization Board.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Supplementary regulations of the Air Transportation Stabilization Board. 1300.3 Section 1300.3 Aeronautics and Space AIR TRANSPORTATION SYSTEM STABILIZATION OFFICE OF MANAGEMENT AND BUDGET AVIATION DISASTER RELIEF-AIR CARRIER GUARANTEE LOAN...

  9. Development of a model for radon concentration in indoor air.

    PubMed

    Jelle, Bjørn Petter

    2012-02-01

    A model is developed for calculation of the radon concentration in indoor air. The model takes into account various important parameters, e.g. radon concentration in ground, radon diffusion resistance of radon barrier, air permeance of ground, air pressure difference between outdoor ground and indoor at ground level, ventilation of the building ground and number of air changes per hour due to ventilation. Characteristic case studies are depicted in selected 2D and 3D graphical plots for easy visualization and interpretation. The radon transport into buildings might be dominated by diffusion, pressure driven flow or a mixture of both depending on the actual values of the various parameters. The results of our work indicate that with realistic or typical values of the parameters, most of the transport of radon from the building ground to the indoor air is due to air leakage driven by pressure differences through the construction. By incorporation of various and realistic values in the radon model, valuable information about the miscellaneous parameters influencing the indoor radon level is gained. Hence, the presented radon model may be utilized as a simple yet versatile and powerful tool for examining which preventive or remedial measures should be carried out to achieve an indoor radon level below the reference level as set by the authorities.

  10. 75 FR 12328 - Application of Charter Air Transport, Inc. for Commuter Authority

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-15

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF TRANSPORTATION Office of the Secretary Application of Charter Air Transport, Inc. for Commuter Authority AGENCY... it should not issue an order finding Charter Air Transport, Inc., fit, willing, and able,...

  11. The ASAC Air Carrier Investment Model (Second Generation)

    NASA Technical Reports Server (NTRS)

    Wingrove, Earl R., III; Johnson, Jesse P.; Sickles, Robin C.; Good, David H.

    1997-01-01

    To meet its objective of assisting the U.S. aviation industry with the technological challenges of the future, NASA must identify research areas that have the greatest potential for improving the operation of the air transportation system. To accomplish this, NASA is building an Aviation System Analysis Capability (ASAC). The ASAC differs from previous NASA modeling efforts in that the economic behavior of buyers and sellers in the air transportation and aviation industries is central to its conception. To link the economics of flight with the technology of flight, ASAC requires a parametrically based mode with extensions that link airline operations and investments in aircraft with aircraft characteristics. This model also must provide a mechanism for incorporating air travel demand and profitability factors into the airlines' investment decisions. Finally, the model must be flexible and capable of being incorporated into a wide-ranging suite of economic and technical models that are envisioned for ASAC. We describe a second-generation Air Carrier Investment Model that meets these requirements. The enhanced model incorporates econometric results from the supply and demand curves faced by U.S.-scheduled passenger air carriers. It uses detailed information about their fleets in 1995 to make predictions about future aircraft purchases. It enables analysts with the ability to project revenue passenger-miles flown, airline industry employment, airline operating profit margins, numbers and types of aircraft in the fleet, and changes in aircraft manufacturing employment under various user-defined scenarios.

  12. Coupled transport in rotor models

    NASA Astrophysics Data System (ADS)

    Iubini, S.; Lepri, S.; Livi, R.; Politi, A.

    2016-08-01

    Steady nonequilibrium states are investigated in a one-dimensional setup in the presence of two thermodynamic currents. Two paradigmatic nonlinear oscillators models are investigated: an XY chain and the discrete nonlinear Schrödinger equation. Their distinctive feature is that the relevant variable is an angle in both cases. We point out the importance of clearly distinguishing between energy and heat flux. In fact, even in the presence of a vanishing Seebeck coefficient, a coupling between (angular) momentum and energy arises, mediated by the unavoidable presence of a coherent energy flux. Such a contribution is the result of the ‘advection’ induced by the position-dependent angular velocity. As a result, in the XY model, the knowledge of the two diagonal elements of the Onsager matrix suffices to reconstruct its transport properties. The analysis of the nonequilibrium steady states finally allows to strengthen the connection between the two models.

  13. Transport Properties for Combustion Modeling

    SciTech Connect

    Brown, N.J.; Bastein, L.; Price, P.N.

    2010-02-19

    This review examines current approximations and approaches that underlie the evaluation of transport properties for combustion modeling applications. Discussed in the review are: the intermolecular potential and its descriptive molecular parameters; various approaches to evaluating collision integrals; supporting data required for the evaluation of transport properties; commonly used computer programs for predicting transport properties; the quality of experimental measurements and their importance for validating or rejecting approximations to property estimation; the interpretation of corresponding states; combination rules that yield pair molecular potential parameters for unlike species from like species parameters; and mixture approximations. The insensitivity of transport properties to intermolecular forces is noted, especially the non-uniqueness of the supporting potential parameters. Viscosity experiments of pure substances and binary mixtures measured post 1970 are used to evaluate a number of approximations; the intermediate temperature range 1 < T* < 10, where T* is kT/{var_epsilon}, is emphasized since this is where rich data sets are available. When suitable potential parameters are used, errors in transport property predictions for pure substances and binary mixtures are less than 5 %, when they are calculated using the approaches of Kee et al.; Mason, Kestin, and Uribe; Paul and Warnatz; or Ern and Giovangigli. Recommendations stemming from the review include (1) revisiting the supporting data required by the various computational approaches, and updating the data sets with accurate potential parameters, dipole moments, and polarizabilities; (2) characterizing the range of parameter space over which the fit to experimental data is good, rather than the current practice of reporting only the parameter set that best fits the data; (3) looking for improved combining rules, since existing rules were found to under-predict the viscosity in most cases; (4

  14. Linking Meteorology, Air Quality Models and Observations to ...

    EPA Pesticide Factsheets

    Epidemiologic studies are critical in establishing the association between exposure to air pollutants and adverse health effects. Results of epidemiologic studies are used by U.S. EPA in developing air quality standards to protect the public from the health effects of air pollutants. A major challenge in environmental epidemiology is adequate exposure characterization. Numerous health studies have used measurements from a few central-site ambient monitors to characterize air pollution exposures. Relying solely on central-site ambient monitors does not account for the spatial-heterogeneity of ambient air pollution patterns, the temporal variability in ambient concentrations, nor the influence of infiltration and indoor sources. Central-site monitoring becomes even more problematic for certain air pollutants that exhibit significant spatial heterogeneity. Statistical interpolation techniques and passive monitoring methods can provide additional spatial resolution in ambient concentration estimates. In addition, spatio-temporal models, which integrate GIS data and other factors, such as meteorology, have also been developed to produce more resolved estimates of ambient concentrations. Models, such as the Community Multi-Scale Air Quality (CMAQ) model, estimate ambient concentrations by combining information on meteorology, source emissions, and chemical-fate and transport. Hybrid modeling approaches, which integrate regional scale models with local scale dispersion

  15. Preliminary results of the MLAM (Multi-Layer Air Mass) Lagrangian transport model simulation of ANATEX (Across North America Tracer Experiment)

    NASA Astrophysics Data System (ADS)

    Davis, William E.; Olsen, Anthony R.; Erb, Trudy A.

    1989-01-01

    The 1987 Across North America Tracer Experiment (ANATEX), for the study of regional to continental-scale transport and diffusion, released perfluorocarbon tracers for three hours every 2.5 days in January, February and March (Draxler et. al. 1985, 1987). The experiment resulted in 33 days of releases at two sites; Glasgow, Montana and St. Cloud, Minnesota. Each release consisted of approximately 50 kg of perfluoro ortho-dimenthoyl cyclohexane (PDCH) at St. Cloud and 83 kg of perfluoro trimethyl cyclohexane (PTCH) at Glasgow. The experiment included the release of a third tracer, 50 kg of perfluoro methyl cyclohexane (PMCH), every five days from St. Cloud; designed to serve as a means to distinguish consecutive releases from St. Cloud. A surface sampling network of 77 sampling sites, located east of 105 degree longitude in the United States and Canada, measured 24-hour average tracer concentrations out to a distance of 3000 km from Glasgow. The network, organized in eight arcs east of Glasgow, collected daily concentrations of each tracer from January 5 through March 29, 1987. The network design provides average daily surface footprint information for the three tracers.

  16. Preliminary results of the MLAM (Multi-Layer Air Mass) Lagrangian transport model simulation of ANATEX (Across North America Tracer Experiment)

    SciTech Connect

    Davis, W.E.; Olsen, A.R.; Erb, T.A.

    1989-01-01

    The 1987 Across North America Tracer Experiment (ANATEX), for the study of regional to continental-scale transport and diffusion, released perfluorocarbon tracers for three hours every 2.5 days in January, February and March (Draxler et. al. 1985, 1987). The experiment resulted in 33 days of releases at two sites; Glasgow, Montana and St. Cloud, Minnesota. Each release consisted of approximately 50 kg of perfluoro-ortho-dimenthoyl-cyclohexane (PDCH) at St. Cloud and 83 kg of perfluoro-trimethyl-cyclohexane (PTCH) at Glasgow. The experiment included the release of a third tracer, 50 kg of perfluoro-methyl-cyclohexane (PMCH), every five days from St. Cloud; designed to serve as a means to distinguish consecutive releases from St. Cloud. A surface sampling network of 77 sampling sites, located east of 105/degree/ longitude in the United States and Canada, measured 24-hour average tracer concentrations out to a distance of 3000 km from Glasgow. The network, organized in eight arcs east of Glasgow, collected daily concentrations of each tracer from January 5 through March 29, 1987. The network design provides average daily surface footprint information for the three tracers. 8 refs., 2 figs.

  17. REGIONAL MODELING OF THE ATMOSPHERIC TRANSPORT AND DEPOSITION OF ATRAZINE

    EPA Science Inventory

    A version of the Community Multiscale Air Quality (CMAQ) model has been developed by the U.S. EPA that is capable of addressing the atmospheric fate, transport and deposition of some common trace toxics. An initial, 36-km rectangular grid-cell application for atrazine has been...

  18. DEVELOPMENT OF THE HS99 AIR TRANSPORT TYPE A FISSILE PACKAGE

    SciTech Connect

    Blanton, P.; Eberl, K.

    2012-07-10

    An air-transport Type A Fissile radioactive shipping package for the transport of special form uranium sources has been developed by the Savannah River National Laboratory (SRNL) for the Department of Homeland Security. The Package model number is HS99 for Homeland Security Model 99. This paper presents the major design features of the HS99 and highlights engineered materials necessary for meeting the design requirements for this light-weight Type AF packaging. A discussion is provided demonstrating how the HS99 complies with the regulatory safety requirements of the Nuclear Regulatory Commission. The paper summarizes the results of structural testing to specified in 10 CFR 71 for Normal Conditions of Transport and Hypothetical Accident Conditions events. Planned and proposed future missions for this packaging are also addressed.

  19. A NEW COMBINED LOCAL AND NON-LOCAL PBL MODEL FOR METEOROLOGY AND AIR QUALITY MODELING

    EPA Science Inventory

    A new version of the Asymmetric Convective Model (ACM) has been developed to describe sub-grid vertical turbulent transport in both meteorology models and air quality models. The new version (ACM2) combines the non-local convective mixing of the original ACM with local eddy diff...

  20. Modeling Trends in Air Pollutant Concentrations over the ...

    EPA Pesticide Factsheets

    Regional model calculations over annual cycles have pointed to the need for accurately representing impacts of long-range transport. Linking regional and global scale models have met with mixed success as biases in the global model can propagate and influence regional calculations and often confound interpretation of model results. Since transport is efficient in the free-troposphere and since simulations over Continental scales and annual cycles provide sufficient opportunity for “atmospheric turn-over”, i.e., exchange between the free-troposphere and the boundary-layer, a conceptual framework is needed wherein interactions between processes occurring at various spatial and temporal scales can be consistently examined. The coupled WRF-CMAQ model is expanded to hemispheric scales and model simulations over period spanning 1990-current are analyzed to examine changes in hemispheric air pollution resulting from changes in emissions over this period. The National Exposure Research Laboratory (NERL) Atmospheric Modeling and Analysis Division (AMAD) conducts research in support of EPA mission to protect human health and the environment. AMAD research program is engaged in developing and evaluating predictive atmospheric models on all spatial and temporal scales for forecasting the air quality and for assessing changes in air quality and air pollutant exposures, as affected by changes in ecosystem management and regulatory decisions. AMAD is responsible for pr

  1. CMAQ MODELING FOR AIR TOXICS AT FINE SCALES: A PROTOTYPE STUDY

    EPA Science Inventory

    Toxic air pollutants (TAPs) or hazardous air pollutants (HAPs) exhibit considerable spatial and temporal variability across urban areas. Therefore, the ability of chemical transport models (CTMs), e.g. Community Multi-scale Air Quality (CMAQ), to reproduce the spatial and tempor...

  2. Urban Air Quality Modelling with AURORA: Prague and Bratislava

    NASA Astrophysics Data System (ADS)

    Veldeman, N.; Viaene, P.; De Ridder, K.; Peelaerts, W.; Lauwaet, D.; Muhammad, N.; Blyth, L.

    2012-04-01

    The European Commission, in its strategy to protect the health of the European citizens, states that in order to assess the impact of air pollution on public health, information on long-term exposure to air pollution should be available. Currently, indicators of air quality are often being generated using measured pollutant concentrations. While air quality monitoring stations data provide accurate time series information at specific locations, air quality models have the advantage of being able to assess the spatial variability of air quality (for different resolutions) and predict air quality in the future based on different scenarios. When running such air quality models at a high spatial and temporal resolution, one can simulate the actual situation as closely as possible, allowing for a detailed assessment of the risk of exposure to citizens from different pollutants. AURORA (Air quality modelling in Urban Regions using an Optimal Resolution Approach), a prognostic 3-dimensional Eulerian chemistry-transport model, is designed to simulate urban- to regional-scale atmospheric pollutant concentration and exposure fields. The AURORA model also allows to calculate the impact of changes in land use (e.g. planting of trees) or of emission reduction scenario's on air quality. AURORA is currently being applied within the ESA atmospheric GMES service, PASODOBLE (http://www.myair-eu.org), that delivers information on air quality, greenhouse gases, stratospheric ozone, … At present there are two operational AURORA services within PASODOBLE. Within the "Air quality forecast service" VITO delivers daily air quality forecasts for Belgium at a resolution of 5 km and for the major Belgian cities: Brussels, Ghent, Antwerp, Liege and Charleroi. Furthermore forecast services are provided for Prague, Czech Republic and Bratislava, Slovakia, both at a resolution of 1 km. The "Urban/regional air quality assessment service" provides urban- and regional-scale maps (hourly resolution

  3. System and method for air temperature control in an oxygen transport membrane based reactor

    DOEpatents

    Kelly, Sean M

    2016-09-27

    A system and method for air temperature control in an oxygen transport membrane based reactor is provided. The system and method involves introducing a specific quantity of cooling air or trim air in between stages in a multistage oxygen transport membrane based reactor or furnace to maintain generally consistent surface temperatures of the oxygen transport membrane elements and associated reactors. The associated reactors may include reforming reactors, boilers or process gas heaters.

  4. The impact of energy, transport, and trade on air pollution in China

    SciTech Connect

    Poon, J.P.H.; Casas, I.; He, C.F.

    2006-09-15

    A team of U.S.- and China-based geographers examines the relationship between China's economic development and its environment by modeling the effects of energy, transport, and trade on local air pollution emissions (sulfur dioxide and soot particulates) using the Environmental Kuznets model. Specifically, the latter model is investigated using spatial econometrics that take into account potential regional spillover effects from high-polluting neighbors. The analysis finds an inverted-U relationship for sulfur dioxide but a U-shaped curve for soot particulates. This suggests that soot particulates such as black carbon may pose a more serious environmental problem in China than sulfur dioxide.

  5. Cost/benefit trade-offs for reducing the energy consumption of commercial air transportation (RECAT)

    NASA Technical Reports Server (NTRS)

    Gobetz, F. W.; Leshane, A. A.

    1976-01-01

    The RECAT study evaluated the opportunities for reducing the energy requirements of the U.S. domestic air passenger transport system through improved operational techniques, modified in-service aircraft, derivatives of current production models, or new aircraft using either current or advanced technology. Each of these fuel-conserving alternatives was investigated individually to test its potential for fuel conservation relative to a hypothetical baseline case in which current, in-production aircraft types are assumed to operate, without modification and with current operational techniques, into the future out to the year 2000. Consequently, while the RECAT results lend insight into the directions in which technology can best be pursued for improved air transport fuel economy, no single option studied in the RECAT program is indicative of a realistic future scenario.

  6. Studies in short haul air transportation in the California corridor: Effects of design runway length; community acceptance; impact of return on investment and fuel cost increases. Volume 2: Appendices

    NASA Technical Reports Server (NTRS)

    Shevell, R. S.; Jones, D. W., Jr.

    1973-01-01

    The development of a forecast model for short haul air transportation systems in the California Corridor is discussed. The factors which determine the level of air traffic demand are identified. A forecast equation for use in airport utilization analysis is developed. A mathematical model is submitted to show the relationship between population, employment, and income for indicating future air transportation utilization. Diagrams and tables of data are included to support the conclusions reached regarding air transportation economic factors.

  7. Evaluation of Transport in the Lower Tropical Stratosphere in a Global Chemistry and Transport Model

    NASA Technical Reports Server (NTRS)

    Douglass, Anne R.; Schoeberl, Mark R.; Rood, Richard B.; Pawson, Steven

    2002-01-01

    A general circulation model (GCM) relies on various physical parameterizations and provides a solution to the atmospheric equations of motion. A data assimilation system (DAS) combines information from observations with a GCM forecast and produces analyzed meteorological fields that represent the observed atmospheric state. An off-line chemistry and transport model (CTM) can use winds and temperatures from a either a GCM or a DAS. The latter application is in common usage for interpretation of observations from various platforms under the assumption that the DAS transport represents the actual atmospheric transport. Here we compare the transport produced by a DAS with that produced by the particular GCM that is combined with observations to produce the analyzed fields. We focus on transport in the tropics and middle latitudes by comparing the age-of-air inferred from observations of SF6 and CO2 with the age-of-air calculated using GCM fields and DAS fields. We also compare observations of ozone, total reactive nitrogen, and methane with results from the two simulations. These comparisons show that DAS fields produce rapid upward tropical transport and excessive mixing between the tropics and middle latitudes. The unrealistic transport produced by the DAS fields may be due to implicit forcing that is required by the assimilation process when there is bias between the GCM forecast and observations that are combined to produce the analyzed fields. For example, the GCM does not produce a quasi-biennial oscillation (QBO). The QBO is present in the analyzed fields because it is present in the observations, and systematic implicit forcing is required by the DAS. Any systematic bias between observations and the GCM forecast used to produce the DAS analysis is likely to corrupt the transport produced by the analyzed fields. Evaluation of transport in the lower tropical stratosphere in a global chemistry and transport model.

  8. Fatigue and associated performance decrements in air transport operations

    NASA Technical Reports Server (NTRS)

    Lyman, E. G.; Orlady, H. W.

    1981-01-01

    A study of safety reports was conducted to examine the hypothesis that fatigue and associated performance decrements occur in air transport operations, and that these are associated with some combination of factors: circadian desynchronosis, duty time; pre-duty activity; sleep; work scheduling; workload; and environmental deprivation. The findings are based on a selected sample of reported incidents in which the reporter associated fatigue with the occurrence. In comparing the fatigue reports with a control set, significant performance decrements were found to exist related to time-of-day, awareness and attention to duty, less significantly, final phases of flights. The majority of the fatigue incidents involved such unsafe events as altitude deviations, takeoffs and landing without clearance, and the like. Considerations of duty and sleep are the major factors in the reported fatigue conditions.

  9. The Economic Effect of Competition in the Air Transportation Industry

    NASA Technical Reports Server (NTRS)

    Hubbard, H. B.

    1972-01-01

    The air transportation industry has been described as a highly-competitive, regulated oligopoly or as a price-regulated cartel with blocked entry, resulting in excessive service and low load factors. The current structure of the industry has been strongly influenced by the hypotheses that increased levels of competition are desirable per se, and that more competing carriers can be economically supported in larger markets, in longer haul markets, with lower unit costs, and with higher fare levels. An elementary application of competition/game theory casts doubt on the validity of these hypotheses, but rather emphasizes the critical importance of the short-term non-variable costs in determining economic levels of competition.

  10. Modeling photon transport in transabdominal fetal oximetry

    NASA Astrophysics Data System (ADS)

    Jacques, Steven L.; Ramanujam, Nirmala; Vishnoi, Gargi; Choe, Regine; Chance, Britton

    2000-07-01

    The possibility of optical oximetry of the blood in the fetal brain measured across the maternal abdomen just prior to birth is under investigated. Such measurements could detect fetal distress prior to birth and aid in the clinical decision regarding Cesarean section. This paper uses a perturbation method to model photon transport through a 8- cm-diam fetal brain located at a constant 2.5 cm below a curved maternal abdominal surface with an air/tissue boundary. In the simulation, a near-infrared light source delivers light to the abdomen and a detector is positioned up to 10 cm from the source along the arc of the abdominal surface. The light transport [W/cm2 fluence rate per W incident power] collected at the 10 cm position is Tm equals 2.2 X 10-6 cm-2 if the fetal brain has the same optical properties as the mother and Tf equals 1.0 X 10MIN6 cm-2 for an optically perturbing fetal brain with typical brain optical properties. The perturbation P equals (Tf - Tm)/Tm is -53% due to the fetal brain. The model illustrates the challenge and feasibility of transabdominal oximetry of the fetal brain.

  11. Survey of projected growth and problems facing air transportation, 1975 - 1985

    NASA Technical Reports Server (NTRS)

    Williams, L. J.; Wilson, A.

    1975-01-01

    Results are presented of a survey conducted to determine the current opinion of people working in air transportation demand forecasting on the future of air transportation over the next ten years. In particular, the survey included questions on future demand growth, load factor, fuel prices, introduction date for the next new aircraft, the priorities of problems facing air transportation, and the probability of a substantial change in air transportation regulation. The survey participants included: airlines, manufacturers, universities, government agencies, and other organizations (financial institutions, private research companies, etc.). The results are shown for the average responses within the organization represented as well as the overall averages.

  12. Proceedings of the Monterey Conference on Planning for Rotorcraft and Commuter Air Transportation

    NASA Technical Reports Server (NTRS)

    Stockwell, W. L.

    1983-01-01

    Planning and technological issues involved in rotorcraft and commuter fixed-wing air transportation are discussed. Subject areas include the future community environment, aircraft technology, community transportation planning, and regulatory perspectives.

  13. Modeling of air pollution from the power plant ash dumps

    NASA Astrophysics Data System (ADS)

    Aleksic, Nenad M.; Balać, Nedeljko

    A simple model of air pollution from power plant ash dumps is presented, with emission rates calculated from the Bagnold formula and transport simulated by the ATDL type model. Moisture effects are accounted for by assumption that there is no pollution on rain days. Annual mean daily sedimentation rates, calculated for the area around the 'Nikola Tesla' power plants near Belgrade for 1987, show reasonably good agreement with observations.

  14. Centrifuge modeling of air sparging - a study of air flow through saturated porous media.

    PubMed

    Marulanda, C; Culligan, P J; Germaine, J T

    2000-02-25

    The success of air sparging as a remedial technology for treatment of contaminated aquifers is well documented. However, there is no consensus, to date, on the mechanisms that control the flow of injected air through the saturated ground. Currently, only qualitative results from laboratory experiments are available to predict the zone of influence of a sparging well. Given that the patterns of air flow through the soil will ultimately determine the efficiency of an air sparging treatment, it is important to quantify how sparged air travels through a saturated porous medium. The main objective of this research is to develop a model that describes air transport through saturated porous media. This paper presents results from an ongoing study that employs centrifuge modeling to reproduce in situ air sparging conditions. Centrifuge testing is an experimental technique that allows reduced-scale duplication, in the laboratory, of the stresses and pressure distributions encountered in the field. In situ conditions are critical in the development of actual air flow patterns. Experiments are being conducted in a transparent porous medium consisting of crushed borosilicate glass submerged in fluids of matching indices of refraction. Air is observed as it flows through the porous medium at varying gravitational accelerations. Recorded images of experiments allow the determination of flow patterns, breakthrough velocities, and plume shapes as a function of g-level and injection pressure. Results show that air flow patterns vary from fingering, at low g-levels, to pulsing at higher accelerations. Grain and pore size distribution of the porous medium do not exclusively control air flow characteristics. Injector geometry has a definite effect on breakthrough velocities and air plume shapes. Experiments have been conducted to compare the velocity of air flow through the saturated porous medium to that of air in pure liquids. Results show that the velocity of air through the medium

  15. Multimodel estimates of premature human mortality due to intercontinental transport of air pollution

    NASA Astrophysics Data System (ADS)

    Liang, C.; Silva, R.; West, J. J.; Sudo, K.; Lund, M. T.; Emmons, L. K.; Takemura, T.; Bian, H.

    2015-12-01

    Numerous modeling studies indicate that emissions from one continent influence air quality over others. Reducing air pollutant emissions from one continent can therefore benefit air quality and health on multiple continents. Here, we estimate the impacts of the intercontinental transport of ozone (O3) and fine particulate matter (PM2.5) on premature human mortality by using an ensemble of global chemical transport models coordinated by the Task Force on Hemispheric Transport of Air Pollution (TF HTAP). We use simulations of 20% reductions of all anthropogenic emissions from 13 regions (North America, Central America, South America, Europe, Northern Africa, Sub-Saharan Africa, Former Soviet Union, Middle East, East Asia, South Asia, South East Asia, Central Asia, and Australia) to calculate their impact on premature mortality within each region and elsewhere in the world. To better understand the impact of potential control strategies, we also analyze premature mortality for global 20% perturbations from five sectors individually: power and industry, ground transport, forest and savannah fires, residential, and others (shipping, aviation, and agriculture). Following previous studies, premature human mortality resulting from each perturbation scenario is calculated using a health impact function based on a log-linear model for O3 and an integrated exposure response model for PM2.5 to estimate relative risk. The spatial distribution of the exposed population (adults aged 25 and over) is obtained from the LandScan 2011 Global Population Dataset. Baseline mortality rates for chronic respiratory disease, ischemic heart disease, cerebrovascular disease, chronic obstructive pulmonary disease, and lung cancer are estimated from the GBD 2010 country-level mortality dataset for the exposed population. Model results are regridded from each model's original grid to a common 0.5°x0.5° grid used to estimate mortality. We perform uncertainty analysis and evaluate the sensitivity

  16. A Transportation Model for a Space Colonization and Manufacturing System: A Q-GERT Simulation.

    DTIC Science & Technology

    1982-12-01

    RAD-RI247685 A TRANSPORTATION MODEL OR A SPACE COLONIZATION AND1/ MANUFACTURING SYSTEM:..U) AIR FORCE INST OF TECH NRIGHT-PATTERSON AFB OH SCHOOL OF...it$ ""distribution is unlimitd- L CTF r DEPARTMENT OF THE AIR FORCE FEB 22 3 C.. AIR UNIVERSITY (ATC) • AIR FORCE INSTITUTE OF TECHNOLOG L&J Wright...Patterson Air Force Base, Ohio _ rig 2Z. 1" 7 AF IT/GSO/OS/82D-6 A TRANSPORTATION MODEL F AR SPACE . I a, cND MANUFACTURING SY-TEM: A 0--CtERT

  17. Lagrangian Transport in a coupled Chemistry Climate Model

    NASA Astrophysics Data System (ADS)

    Hoppe, C.; Müller, R.; Günther, G.; Hoffmann, L.

    2012-04-01

    We describe the implementation of a Lagrangian transport core in a chemistry climate model (CCM). This is motivated by the problem that in many cases trace gas distributions in the stratosphere can not be represented properly in a classical Eulerian framework with a fixed model grid, especially in regions where strong trace gas gradients occur. Here, we focus on stratospheric water vapor, which is an important driver of surface climate change on decadal scales. In this case, the transport representation is particularly important in the tropical tropopause layer (TTL), where tropospheric air enters into the stratosphere, i.e. , where the entry level of stratospheric water vapor is determined. For this purpose, the Chemical Lagrangian Model of the Stratosphere (CLaMS) is coupled with the ECHAM/MESSy Atmospheric Chemistry Model (EMAC). The latter includes the ECHAM5 climate model, and a coupling interface, which allows for flexible coupling and switching between different submodels. The chemistry transport model CLaMS provides a full Lagrangian transport representation to calculate constituent transport on a set of air parcels that move along trajectories. In the Lagrangian frame of reference, different vertical velocity representations can be used to drive the trajectories: - kinematic transport in isobaric coordinates with omega as vertical velocity, - diabatic transport in isentropic coordinates, where thetadot calculated from diabatic heatingrates is used as vertical velocity. Since vertical winds in the statosphere derived with the kinematic method from the continuity equation often suffer from excessive numerical noise and errors, we expect that constituent transport using the diabatic method will improve the simulations of stratospheric water vapor. We will present preliminary results illustrating how the different transport representations influence simulated tracer distributions.

  18. Short-haul CTOL aircraft research. [on reduced energy for commercial air transportation

    NASA Technical Reports Server (NTRS)

    Williams, L. J.

    1978-01-01

    The results of the reduced energy for commercial air transportation studies on air transportation energy efficiency improvement alternatives are reviewed along with subsequent design studies of advanced turboprop powered transport aircraft. The application of this research to short-haul transportation is discussed. The results of several recent turboprop aircraft design are included. The potential fuel savings and cost savings for advanced turboprop aircraft appear substantial, particularly at shorter ranges.

  19. Modeling energy transport in nanostructures

    NASA Astrophysics Data System (ADS)

    Pattamatta, Arvind

    Heat transfer in nanostructures differ significantly from that in the bulk materials since the characteristic length scales associated with heat carriers, i.e., the mean free path and the wavelength, are comparable to the characteristic length of the nanostructures. Nanostructure materials hold the promise of novel phenomena, properties, and functions in the areas of thermal management and energy conversion. Example of thermal management in micro/nano electronic devices is the use of efficient nanostructured materials to alleviate 'hot spots' in integrated circuits. Examples in the manipulation of heat flow and energy conversion include nanostructures for thermoelectric energy conversion, thermophotovoltaic power generation, and data storage. One of the major challenges in Metal-Oxide Field Effect Transistor (MOSFET) devices is to study the 'hot spot' generation by accurately modeling the carrier-optical phonon-acoustic phonon interactions. Prediction of hotspot temperature and position in MOSFET devices is necessary for improving thermal design and reliability of micro/nano electronic devices. Thermoelectric properties are among the properties that may drastically change at nanoscale. The efficiency of thermoelectric energy conversion in a material is measured by a non-dimensional figure of merit (ZT) defined as, ZT = sigmaS2T/k where sigma is the electrical conductivity, S is the Seebeck coefficient, T is the temperature, and k is the thermal conductivity. During the last decade, advances have been made in increasing ZT using nanostructures. Three important topics are studied with respect to energy transport in nanostructure materials for micro/nano electronic and thermoelectric applications; (1) the role of nanocomposites in improving the thermal efficiency of thermoelectric devices, (2) the interfacial thermal resistance for the semiconductor/metal contacts in thermoelectric devices and for metallic interconnects in micro/nano electronic devices, (3) the

  20. A Program in Air Transportation Technology (Joint University Program)

    NASA Technical Reports Server (NTRS)

    Stengel, Robert F.

    1996-01-01

    The Joint University Program on Air Transportation Technology was conducted at Princeton University from 1971 to 1995. Our vision was to further understanding of the design and operation of transport aircraft, of the effects of atmospheric environment on aircraft flight, and of the development and utilization of the National Airspace System. As an adjunct, the program emphasized the independent research of both graduate and undergraduate students. Recent principal goals were to develop and verify new methods for design and analysis of intelligent flight control systems, aircraft guidance logic for recovery from wake vortex encounter, and robust flight control systems. Our research scope subsumed problems associated with multidisciplinary aircraft design synthesis and analysis based on flight physics, providing a theoretical basis for developing innovative control concepts that enhance aircraft performance and safety. Our research focus was of direct interest not only to NASA but to manufacturers of aircraft and their associated systems. Our approach, metrics, and future directions described in the remainder of the report.

  1. Fixed Wing Project: Technologies for Advanced Air Transports

    NASA Technical Reports Server (NTRS)

    Del Rosario, Ruben; Koudelka, John M.; Wahls, Richard A.; Madavan, Nateri

    2014-01-01

    The NASA Fundamental Aeronautics Fixed Wing (FW) Project addresses the comprehensive challenge of enabling revolutionary energy efficiency improvements in subsonic transport aircraft combined with dramatic reductions in harmful emissions and perceived noise to facilitate sustained growth of the air transportation system. Advanced technologies and the development of unconventional aircraft systems offer the potential to achieve these improvements. Multidisciplinary advances are required in aerodynamic efficiency to reduce drag, structural efficiency to reduce aircraft empty weight, and propulsive and thermal efficiency to reduce thrust-specific energy consumption (TSEC) for overall system benefit. Additionally, advances are required to reduce perceived noise without adversely affecting drag, weight, or TSEC, and to reduce harmful emissions without adversely affecting energy efficiency or noise.The presentation will highlight the Fixed Wing project vision of revolutionary systems and technologies needed to achieve these challenging goals. Specifically, the primary focus of the FW Project is on the N+3 generation; that is, vehicles that are three generations beyond the current state of the art, requiring mature technology solutions in the 2025-30 timeframe.

  2. 77 FR 17394 - Hazardous Materials: Approval and Communication Requirements for the Safe Transportation of Air...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-26

    ... transportation of hazardous materials by highway, rail, vessel, and air. The scope of the HMR includes hazardous.... Congress expressly authorized DOT to issue variances in the Hazardous Materials Transportation Act of 1975... include: The safety record for hazardous materials transported; transportation operations......

  3. An Application of the Methodology for Assessment of the Sustainability of Air Transport System

    NASA Technical Reports Server (NTRS)

    Janic, Milan

    2003-01-01

    An assessment and operationalization of the concept of sustainable air transport system is recognized as an important but complex research, operational and policy task. In the scope of the academic efforts to properly address the problem, this paper aims to assess the sustainability of air transport system. It particular, the paper describes the methodology for assessment of sustainability and its potential application. The methodology consists of the indicator systems, which relate to the air transport system operational, economic, social and environmental dimension of performance. The particular indicator systems are relevant for the particular actors such users (air travellers), air transport operators, aerospace manufacturers, local communities, governmental authorities at different levels (local, national, international), international air transport associations, pressure groups and public. In the scope of application of the methodology, the specific cases are selected to estimate the particular indicators, and thus to assess the system sustainability under given conditions.

  4. Model transport directional solidification apparatus

    SciTech Connect

    Mason, J.T.; Eshelman, M.A.

    1986-07-01

    A model transport directional solidification apparatus is described. It has three functional components, each of which are described: the temperature gradient stage, the motor and drive mechanism, and the measuring systems. A small amount of sample is held between two glass slides on the temperature gradient stage so that the portion of sample in the hot chamber is molten and the portion in the cold chamber is solidified. Conditions are set so that the solid-liquid interface occurs in the gap between the chambers and can be observed through the microscope system. In-situ directional solidification is observed by driving the sample from the hot chamber to the cold chamber and observing the solidification process as it occurs. (LEW)

  5. Understanding Air Transportation Market Dynamics Using a Search Algorithm for Calibrating Travel Demand and Price

    NASA Technical Reports Server (NTRS)

    Kumar, Vivek; Horio, Brant M.; DeCicco, Anthony H.; Hasan, Shahab; Stouffer, Virginia L.; Smith, Jeremy C.; Guerreiro, Nelson M.

    2015-01-01

    This paper presents a search algorithm based framework to calibrate origin-destination (O-D) market specific airline ticket demands and prices for the Air Transportation System (ATS). This framework is used for calibrating an agent based model of the air ticket buy-sell process - Airline Evolutionary Simulation (Airline EVOS) -that has fidelity of detail that accounts for airline and consumer behaviors and the interdependencies they share between themselves and the NAS. More specificially, this algorithm simultaneous calibrates demand and airfares for each O-D market, to within specified threshold of a pre-specified target value. The proposed algorithm is illustrated with market data targets provided by the Transportation System Analysis Model (TSAM) and Airline Origin and Destination Survey (DB1B). Although we specify these models and datasources for this calibration exercise, the methods described in this paper are applicable to calibrating any low-level model of the ATS to some other demand forecast model-based data. We argue that using a calibration algorithm such as the one we present here to synchronize ATS models with specialized forecast demand models, is a powerful tool for establishing credible baseline conditions in experiments analyzing the effects of proposed policy changes to the ATS.

  6. Simulation model air-to-air plate heat exchanger

    SciTech Connect

    Wetter, Michael

    1999-01-01

    A simple simulation model of an air-to-air plate heat exchanger is presented. The model belongs to a collection of simulation models that allows the eflcient computer simulation of heating, ventilation, and air-conditioning (HVAC) systems. The main emphasis of the models is to shorten computation time and to use only input data that are known in the design process of an HVAC system. The target of the models is to describe the behavior of HVAC components in the part-load operation mode, which is becoming increasingly important in energy eficient HVAC systems. The models are intended to be used for yearly energy calculations or load calculations with time steps of about 10 minutes or larger. Short- time dynamic effects, which are of interest for different aspects of control theory, are neglected. The part-load behavior is expressed in terms of the nominal condition and the dimensionless variation of the heat transfer with change of mass flow and temperature. The effectiveness- NTU relations are used to parametrize the convective heat transfer at nominal conditions and to compute the part-load condition. If the heat transfer coefficients on the two exchanger sides are not equal (i. e. due to partial bypassing of air), their ratio can be easily calculated and set as a parameter. The model is static and uses explicit equations only. The explicit model formulation ensures short computation time and numerical stability, which allows using the model with sophisticated engineering methods like automatic system optimization. This paper fully outlines the algorithm description and its simplifications. It is not tailored for any particular simulation program to ensure easy implementation in any simulation program.

  7. Modeling Transport Through Synthetic Nanopores

    PubMed Central

    Aksimentiev, Aleksei; Brunner, Robert K.; Cruz-Chú, Eduardo; Comer, Jeffrey; Schulten, Klaus

    2011-01-01

    Nanopores in thin synthetic membranes have emerged as convenient tools for high-throughput single-molecule manipulation and analysis. Because of their small sizes and their ability to selectively transport solutes through otherwise impermeable membranes, nanopores have numerous potential applications in nanobiotechnology. For most applications, properties of the nanopore systems have to be characterize at the atomic level, which is currently beyond the limit of experimental methods. Molecular dynamics (MD) simulations can provide the desired information, however several technical challenges have to be met before this method can be applied to synthetic nanopore systems. Here, we highlight our recent work on modeling synthetic nanopores of the most common types. First, we describe a novel graphical tool for setting up all-atom systems incorporating inorganic materials and biomolecules. Next, we illustrate the application of the MD method for silica, silicon nitride, and polyethylene terephthalate nanopores. Following that, we describe a method for modeling synthetic surfaces using a bias potential. Future directions for tool development and nanopore modeling are briefly discussed at the end of this article. PMID:21909347

  8. Climatology of wintertime long-distance transport of surface-layer air masses arriving urban Beijing in 2001-2012

    NASA Astrophysics Data System (ADS)

    Chen, Bin; Xiang-De, XU

    2017-02-01

    In this study, the FLEXPART-WRF coupled modeling system is used to conduct 12-year Lagrangian modeling over Beijing, China, for the winters of 2001-2012. Based on large trajectory tracking ensembles, the long-range air transport properties, in terms of geographic source regions within the atmospheric planetary boundary layer (PBL) and large-scale ventilation, and its association with air quality levels were quantified from a climatological perspective. The results show the following: (1) The air masses residing in the near-surface layer over Beijing potentially originate from broader atmospheric boundary-layer regions, which cover vast areas with the backward tracking time elapsed. However, atmospheric transport from northeastern China and, to a lesser extent, from the surrounding regions of Beijing is important. (2) The evolution of air quality over Beijing is negatively correlated with large-scale ventilation conditions, particularly at a synoptic timescale. Thus, the simple but robust backward-trajectory ventilation (BV) index defined in this study could facilitate operational forecasting of severe air pollution events. (3) By comparison, the relatively short-range transport occurring over transport timescales of less than 3 days from southern and southeastern Beijing and its surrounding areas plays a vital role in the formation of severe air pollution events during the wintertime. (4) Additionally, an interannual trend analysis suggests that the geographic sources and ventilation conditions also changed, at least over the last decade, corresponding to the strength variability of the winter East Asian monsoon.

  9. A Fuzzy Approach of the Competition on the Air Transport Market

    NASA Technical Reports Server (NTRS)

    Charfeddine, Souhir; DeColigny, Marc; Camino, Felix Mora; Cosenza, Carlos Alberto Nunes

    2003-01-01

    The aim of this communication is to study with a new scope the conditions of the equilibrium in an air transport market where two competitive airlines are operating. Each airline is supposed to adopt a strategy maximizing its profit while its estimation of the demand has a fuzzy nature. This leads each company to optimize a program of its proposed services (frequency of the flights and ticket prices) characterized by some fuzzy parameters. The case of monopoly is being taken as a benchmark. Classical convex optimization can be used to solve this decision problem. This approach provides the airline with a new decision tool where uncertainty can be taken into account explicitly. The confrontation of the strategies of the companies, in the ease of duopoly, leads to the definition of a fuzzy equilibrium. This concept of fuzzy equilibrium is more general and can be applied to several other domains. The formulation of the optimization problem and the methodological consideration adopted for its resolution are presented in their general theoretical aspect. In the case of air transportation, where the conditions of management of operations are critical, this approach should offer to the manager elements needed to the consolidation of its decisions depending on the circumstances (ordinary, exceptional events,..) and to be prepared to face all possibilities. Keywords: air transportation, competition equilibrium, convex optimization , fuzzy modeling,

  10. Journal of Air Transportation, Volume 8, No. 2. Volume 8, No. 2

    NASA Technical Reports Server (NTRS)

    Bowen, Brent (Editor); Kabashkin, Igor (Editor); Nickerson, Jocelyn (Editor)

    2003-01-01

    The mission of the Journal of Air Transportation (JAT) is to provide the global community immediate key resource information in all areas of air transportation. This journal contains articles on the following:Fuel Consumption Modeling of a Transport Category Aircraft: A FlightOperationsQualityAssurance (F0QA) Analysis;Demand for Air Travel in the United States: Bottom-Up Econometric Estimation and Implications for Forecasts by Origin and Destination Pairs;Blind Flying on the Beam: Aeronautical Communication, Navigation and Surveillance: Its Origins and the Politics of Technology: Part I1 Political Oversight and Promotion;Blind Flying on the Beam: Aeronautical Communication, Navigation and Surveillance: Its Origins and the Politics of Technology: Part 111: Emerging Technologies;Ethics Education in University Aviation Management Programs in the US: Part Two B-Statistical Analysis of Current Practice;Integrating Human Factors into the Human-computer Interface: and How Best to Display Meteorological Information for Critical Aviation Decision-making and Performance.

  11. Turbulent transport across an interface between dry and humid air in a stratified environment

    NASA Astrophysics Data System (ADS)

    Gallana, Luca; de Santi, Francesca; di Savino, Silvio; Iovieno, Michele; Ricchiardone, Renzo; Tordella, Daniela

    2014-11-01

    The transport of energy and water vapor across a thin layer which separates two decaying isotropic turbulent flows with different kinetic energy and humidity is considered. The interface is placed in a shearless stratified environment in temporal decay. This system reproduces a few aspects of small scale turbulent transport across a dry air/moist air interface in an atmospheric like context. In our incompressible DNS at Reλ = 250 , Boussinesq's approximation is used for momentum and energy transport while the vapor is modeled as a passive scalar (Kumar, Schumacher & Shaw 2014). We investigated different stratification levels with an initial Fr between 0.8 and 8 in presence of a kinetic energy ratio equal to 7. As the buoyancy term becomes of the same order of the inertial ones, a spatial redistribution of kinetic energy, dissipation and vapor concentration is observed. This eventually leads to the onset of a well of kinetic energy in the low energy side of the mixing layer which blocks the entrainment of dry air. Results are discussed and compared with laboratory and numerical experiments. A posteriori estimates of the eventual compression/expansion of fluid particles inside the interfacial mixing layer are given (Nance & Durran 1994).

  12. Community Multi-scale Air Quality (CMAQ) Modeling System for Air Quality Management

    EPA Pesticide Factsheets

    CMAQ simultaneously models multiple air pollutants including ozone, particulate matter and a variety of air toxics to help air quality managers determine the best air quality management scenarios for their communities, regions and states.

  13. Numerical Simulations of Dynamic Deformation of Air Transport Fresh Fuel Package in Accidental Impacts

    SciTech Connect

    Ryabov, A. A.; Romanov, V. I.; Sotskov, G. I.

    2003-02-24

    Results of numerical investigations of dynamic deformations of packages for air transportation of fresh nuclear fuel from Nuclear Power Plants are presented for the cases of axis and on-side impacts with hard surface at a speed of 90 meters/second (m/s). Modeling results on deformed structure shapes and kinematical parameters (displacements, decelerations, cramping) for axis impact are compared with experimental data. Use of this numerical-experimental technology gives new capabilities to analyze correctly the safety of such a package in accidents through modeling, which does not require implantation of expensive testing, thereby saving money.

  14. The world's air transportation services : data as to passengers, mail, and goods carried by American and European transportation services

    NASA Technical Reports Server (NTRS)

    1922-01-01

    This report presents detailed descriptions, statistics, and graphs on European and American air transport. The European countries listed are Belgium, Czecho-Slovakia, Denmark, France, Germany, Great Britain, Holland, and Italy.

  15. Air Pollution Modeling Using A 3-d Hemispheric Nested Model

    NASA Astrophysics Data System (ADS)

    Frohn, L. M.; Christensen, J. H.; Brandt, J.; Hertel, O.

    A 3-D Eulerian transport-chemistry model based on modules and parameterisations from models developed over the last decade at the National Environmental Research Institute (DREAM, DEHM, ACDEP and DEOM) has been developed. The model is hemispheric with currently two nests implemented. The horizontal resolution in the mother domain is 150 km x 150 km. First nest covers the European area wit,h a 50 km x 50 km resolution, second covers the Scandinavian area with a resolution of 16.67 km x 16.67 km. The model employs a chemical scheme (originally 53 species) which has been modified to include a detailed description of the nitrogen chemistry. The concentration of air pollutants, such as sulfur and nitrogen in various forms, has been calculated with the model, applying no nesting as well as one and two nests. The calculated values have been validated by comparison to measurements from more than 200 EMEP monitoring stations. Furthermore deposition of nitrogen to marine waters has been estimated with the model. The goal is to obtain an improved description of spatial and temporal variations in the nutrient deposition to the marine environment. In the presentation the physics and chemistry of the model will be shortly described. Validations of the model calculations by comparison to EMEP measurements will be shown and discussed together with the results of the deposition calculations.

  16. 76 FR 2744 - Disclosure of Code-Share Service by Air Carriers and Sellers of Air Transportation

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-14

    ... Office of the Secretary Disclosure of Code-Share Service by Air Carriers and Sellers of Air... Department is publishing the following notice on the enforcement of its rules relating to disclosure of code... Transportation, Office of the Secretary, Washington, DC Guidance on Disclosure of Code-Share Service Under...

  17. Emission estimates for air pollution transport models.

    SciTech Connect

    Streets, D. G.

    1998-10-09

    The results of studies of energy consumption and emission inventories in Asia are discussed. These data primarily reflect emissions from fuel combustion (both biofuels and fossil fuels) and were collected to determine emissions of acid-deposition precursors (SO{sub 2} and NO{sub x}) and greenhouse gases (CO{sub 2} CO, CH{sub 4}, and NMHC) appropriate to RAINS-Asia regions. Current work is focusing on black carbon (soot), volatile organic compounds, and ammonia.

  18. Journal of Air Transportation, Volume 11, No. 2

    NASA Technical Reports Server (NTRS)

    Bowen, Brent (Editor); Kabashkin, Igor (Editor); Gudmundsson, Sveinn Vidar (Editor); EspiritoSanto, Jr. Respicio (Editor)

    2006-01-01

    The following topics were covered: How Do Airlines Perceive That Strategic Alliances Affect Their Individual Branding?; Airline Choice for Domestic Flights in Sao Paulo Metropolitan Area: An Application of the Conditional Logit Model; Consequences of Feeder Delays for the Success of A380 Operations; Inside the Mechanics of Network Development: How Competition and Strategy Reorganize European Air Traffic; The Opportunities and Threats of Turning Airports into Hubs; Another Approach to Enhance Airline Safety: Using System Safety Tools; A Simulation Based Approach for Contingency Planning for Aircraft Turnaround Activities in Airline Hubs; and The Council on Aviation Accreditation: Part One- Historical Foundation.

  19. COMMUNITY SCALE AIR TOXICS MODELING WITH CMAQ

    EPA Science Inventory

    Consideration and movement for an urban air toxics control strategy is toward a community, exposure and risk-based modeling approach, with emphasis on assessments of areas that experience high air toxic concentration levels, the so-called "hot spots". This strategy will requir...

  20. NASA/Air Force Cost Model: NAFCOM

    NASA Technical Reports Server (NTRS)

    Winn, Sharon D.; Hamcher, John W. (Technical Monitor)

    2002-01-01

    The NASA/Air Force Cost Model (NAFCOM) is a parametric estimating tool for space hardware. It is based on historical NASA and Air Force space projects and is primarily used in the very early phases of a development project. NAFCOM can be used at the subsystem or component levels.

  1. Smogbusters: Grassroots Action for Clean Air and Sustainable Transport in Australia

    ERIC Educational Resources Information Center

    Manners, Eric; Wake, David; Carlisle, Rachel

    2009-01-01

    Smogbusters was a national, community-based, government-funded community education program promoting clean air and sustainable transport in Australia from 1994 to 2002. Smogbusters aimed to improve air quality primarily by raising awareness about motor vehicle transport and its negative impacts on health, the environment and communities, and by…

  2. 14 CFR Sec. 19-5 - Air transport traffic and capacity elements.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Air transport traffic and capacity elements... elements. (a) Within each of the service classifications prescribed in section -19-4, data shall be reported as applicable to specified air transport traffic and capacity elements. (b) These reported...

  3. 14 CFR Sec. 19-5 - Air transport traffic and capacity elements.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Air transport traffic and capacity elements... elements. (a) Within each of the service classifications prescribed in section -19-4, data shall be reported as applicable to specified air transport traffic and capacity elements. (b) These reported...

  4. Contributions of trans-boundary transport to summertime air quality in Beijing, China

    NASA Astrophysics Data System (ADS)

    Wu, Jiarui; Li, Guohui; Cao, Junji; Bei, Naifang; Wang, Yichen; Feng, Tian; Huang, Rujin; Liu, Suixin; Zhang, Qiang; Tie, Xuexi

    2017-02-01

    In the present study, the WRF-CHEM model is used to evaluate the contributions of trans-boundary transport to the air quality in Beijing during a persistent air pollution episode from 5 to 14 July 2015 in Beijing-Tianjin-Hebei (BTH), China. Generally, the predicted temporal variations and spatial distributions of PM2.5 (fine particulate matter), O3 (ozone), and NO2 are in good agreement with observations in BTH. The WRF-CHEM model also reproduces reasonably well the temporal variations of aerosol species compared to measurements in Beijing. The factor separation approach is employed to evaluate the contributions of trans-boundary transport of non-Beijing emissions to the PM2.5 and O3 levels in Beijing. On average, in the afternoon during the simulation episode, the local emissions contribute 22.4 % to the O3 level in Beijing, less than 36.6 % from non-Beijing emissions. The O3 concentrations in Beijing are decreased by 5.1 % in the afternoon due to interactions between local and non-Beijing emissions. The non-Beijing emissions play a dominant role in the PM2.5 level in Beijing, with a contribution of 61.5 %, much higher than 13.7 %, from Beijing local emissions. The emission interactions between local and non-Beijing emissions enhance the PM2.5 concentrations in Beijing, with a contribution of 5.9 %. Therefore, the air quality in Beijing is generally determined by the trans-boundary transport of non-Beijing emissions during summertime, showing that the cooperation with neighboring provinces to mitigate pollutant emissions is key for Beijing to improve air quality.

  5. Aircraft Weather Mitigation for the Next Generation Air Transportation System

    NASA Technical Reports Server (NTRS)

    Stough, H. Paul, III

    2007-01-01

    Atmospheric effects on aviation are described by Mahapatra (1999) as including (1) atmospheric phenomena involving air motion - wind shear and turbulence; (2) hydrometeorological phenomena - rain, snow and hail; (3) aircraft icing; (4) low visibility; and (5) atmospheric electrical phenomena. Aircraft Weather Mitigation includes aircraft systems (e.g. airframe, propulsion, avionics, controls) that can be enacted (by a pilot, automation or hybrid systems) to suppress and/or prepare for the effects of encountered or unavoidable weather or to facilitate a crew operational decision-making process relative to weather. Aircraft weather mitigation can be thought of as a continuum (Figure 1) with the need to avoid all adverse weather at one extreme and the ability to safely operate in all weather conditions at the other extreme. Realistic aircraft capabilities fall somewhere between these two extremes. The capabilities of small general aviation aircraft would be expected to fall closer to the "Avoid All Adverse Weather" point, and the capabilities of large commercial jet transports would fall closer to the "Operate in All Weather Conditions" point. The ability to safely operate in adverse weather conditions is dependent upon the pilot s capabilities (training, total experience and recent experience), the airspace in which the operation is taking place (terrain, navigational aids, traffic separation), the capabilities of the airport (approach guidance, runway and taxiway lighting, availability of air traffic control), as well as the capabilities of the airplane. The level of mitigation may vary depending upon the type of adverse weather. For example, a small general aviation airplane may be equipped to operate "in the clouds" without outside visual references, but not be equipped to prevent airframe ice that could be accreted in those clouds.

  6. RADIONUCLIDE TRANSPORT MODELS UNDER AMBIENT CONDITIONS

    SciTech Connect

    S. Magnuson

    2004-11-01

    The purpose of this model report is to document the unsaturated zone (UZ) radionuclide transport model, which evaluates, by means of three-dimensional numerical models, the transport of radioactive solutes and colloids in the UZ, under ambient conditions, from the repository horizon to the water table at Yucca Mountain, Nevada.

  7. An uncertainty analysis of air pollution externalities from road transport in Belgium in 2010.

    PubMed

    Int Panis, L; De Nocker, L; Cornelis, E; Torfs, R

    2004-12-01

    Although stricter standards for vehicles will reduce emissions to air significantly by 2010, a number of problems will remain, especially related to particulate concentrations in cities, ground-level ozone, and CO(2). To evaluate the impacts of new policy measures, tools need to be available that assess the potential benefits of these measures in terms of the vehicle fleet, fuel choice, modal choice, kilometers driven, emissions, and the impacts on public health and related external costs. The ExternE accounting framework offers the most up to date and comprehensive methodology to assess marginal external costs of energy-related pollutants. It combines emission models, air dispersion models at local and regional scales with dose-response functions and valuation rules. Vito has extended this accounting framework with data and models related to the future composition of the vehicle fleet and transportation demand to evaluate the impact of new policy proposals on air quality and aggregated (total) external costs by 2010. Special attention was given to uncertainty analysis. The uncertainty for more than 100 different parameters was combined in Monte Carlo simulations to assess the range of possible outcomes and the main drivers of these results. Although the impacts from emission standards and total fleet mileage look dominant at first, a number of other factors were found to be important as well. This includes the number of diesel vehicles, inspection and maintenance (high-emitter cars), use of air conditioning, and heavy duty transit traffic.

  8. Entity-Centric Abstraction and Modeling Framework for Transportation Architectures

    NASA Technical Reports Server (NTRS)

    Lewe, Jung-Ho; DeLaurentis, Daniel A.; Mavris, Dimitri N.; Schrage, Daniel P.

    2007-01-01

    A comprehensive framework for representing transpportation architectures is presented. After discussing a series of preceding perspectives and formulations, the intellectual underpinning of the novel framework using an entity-centric abstraction of transportation is described. The entities include endogenous and exogenous factors and functional expressions are offered that relate these and their evolution. The end result is a Transportation Architecture Field which permits analysis of future concepts under the holistic perspective. A simulation model which stems from the framework is presented and exercised producing results which quantify improvements in air transportation due to advanced aircraft technologies. Finally, a modeling hypothesis and its accompanying criteria are proposed to test further use of the framework for evaluating new transportation solutions.

  9. Study of interfacial area transport and sensitivity analysis for air-water bubbly flow

    SciTech Connect

    Kim, S.; Sun, X.; Ishii, M.; Beus, S.G.

    2000-09-01

    The interfacial area transport equation applicable to the bubbly flow is presented. The model is evaluated against the data acquired by the state-of-the-art miniaturized double-sensor conductivity probe in an adiabatic air-water co-current vertical test loop under atmospheric pressure condition. In general, a good agreement, within the measurement error of plus/minus 10%, is observed for a wide range in the bubbly flow regime. The sensitivity analysis on the individual particle interaction mechanisms demonstrates the active interactions between the bubbles and highlights the mechanisms playing the dominant role in interfacial area transport. The analysis employing the drift flux model is also performed for the data acquired. Under the given flow conditions, the distribution parameter of 1.076 yields the best fit to the data.

  10. Air Tightness of US Homes: Model Development

    SciTech Connect

    Sherman, Max H.

    2006-05-01

    Air tightness is an important property of building envelopes. It is a key factor in determining infiltration and related wall-performance properties such as indoor air quality, maintainability and moisture balance. Air leakage in U.S. houses consumes roughly 1/3 of the HVAC energy but provides most of the ventilation used to control IAQ. The Lawrence Berkeley National Laboratory has been gathering residential air leakage data from many sources and now has a database of more than 100,000 raw measurements. This paper uses that database to develop a model for estimating air leakage as a function of climate, building age, floor area, building height, floor type, energy-efficiency and low-income designations. The model developed can be used to estimate the leakage distribution of populations of houses.

  11. A Review of the Thermodynamic, Transport, and Chemical Reaction Rate Properties of High-temperature Air

    NASA Technical Reports Server (NTRS)

    Hansen, C Frederick; Heims, Steve P

    1958-01-01

    Thermodynamic and transport properties of high temperature air, and the reaction rates for the important chemical processes which occur in air, are reviewed. Semiempirical, analytic expressions are presented for thermodynamic and transport properties of air. Examples are given illustrating the use of these properties to evaluate (1) equilibrium conditions following shock waves, (2) stagnation region heat flux to a blunt high-speed body, and (3) some chemical relaxation lengths in stagnation region flow.

  12. Air transport of the IABP patient. Intra-Aortic Balloon Pump.

    PubMed

    Hatlestad, Daniel C; Van Horn, Julie

    2002-01-01

    The intra-aortic balloon pump (IABP) has evolved into an easily transported, computer-driven device for invasively assisting circulation. This article reviews the use of the IABP during interfacility patient transport by air. Air transport of the IABP-dependent patient creates unique clinical, logistical, and technical challenges. We review the function and clinical application of IABP in various air transport conditions. We also identify the complications of intra-aortic balloon pumping, such as hemorrhage, loss of trigger signals, cardiac arrest, and atmospheric pressure changes, and offer solutions. The effective clinical use of IABP in the air transport environment involves more than familiarity with the device and implications for its use; rapid identification of problems and implementation of solutions are required for successful transport and patient outcomes.

  13. The Double Counting Problem in Neighborhood Scale Air Quality Modeling

    NASA Astrophysics Data System (ADS)

    Du, S.; Hughes, V.; Woodhouse, L.; Servin, A.

    2004-12-01

    Air quality varies considerably within megacities. In certain neighborhoods concentrations of toxic air contaminants (TACs) can be appreciably higher than that in other neighborhoods of the same city. These pockets of high concentrations are associated with both transport of TACs from other areas and local emissions. In order to assess the health risks imposed by TACs at neighborhood scale and to develop strategies of abatement, neighborhood scale air quality modeling is needed. In 1999, the California Air Resources Board (ARB) established the Neighborhood Assessment Program (NAP) - a program designed to develop assessment tools for evaluating and understanding air quality in California communities. As part of the Neighborhood Assessment Program, ARB is conducting research on neighborhood-scale modeling methodologies. Two criteria are suggested to select a neighborhood scale air quality modeling system that can be used to assess concentrations of TACs: scientific soundness and balancing computational requirements. The latter criterion ensures that as many interested parties as possible can participate the process of air quality modeling so that they have a better understanding of air quality issues and make best use of air quality modeling results in their neighborhoods. Based on these two selection criteria a hybrid approach is recommended. This hybrid approach is a combination of using both a regional scale air quality model to assess the contributions from sources that are not located within the neighborhood of interest and a microscale model to assess the impact from the local sources that are within the neighborhood. However, one of the modeling system selection criteria, balancing computational requirements, dictates that all sources (both within and outside the neighborhood of interest) must be included in the regional scale modeling. A potential problem, referred to as double counting, arises because some local sources are included in both regional and

  14. European Air Quality and Climate Change: a numerical modeling study

    NASA Astrophysics Data System (ADS)

    Lacressonniere, G.

    2011-12-01

    In the context of climate change, the evolution of air quality in Europe is a challenging scientific question, despite the political measures taken to limit and reduce anthropogenic emissions. Heat waves, changes in transport pathways or synoptic patterns, increase of emissions in other areas in the world, or for instance possible increase of biogenic emissions or changes in deposition and land use may affect adversely future Air Quality levels in Europe. In the context of a project co-funded by the French environment agency ADEME, a numerical modeling study has begun relying on the tools used by Météo-France for its contribution to the 5th IPCC assessment report, to GMES atmospheric services (MACC FP7 project) and to the French national operational Air Quality platform Prév'Air (http://www.prevair.org). In particular, the MOCAGE 3-D chemical transport model (CTM) is used with a configuration comprising a global (2°) and a European domain (0.2°), allowing representation of both long-range transport of pollutants and European Air Quality at relevant resolutions and with a two-ways coupling. MOCAGE includes 47 layers from the surface to 5hPa. The first step of this project was to assess the impact of meteorological forcings, either analyses ("best" meteorology available for the recent past) or climate runs for the current atmosphere, on air quality hindcasts with MOCAGE over Europe. For these climate runs, we rely on Météo-France Earth-System model CNRM-CM, and particularly the ARPEGE-climate general circulation model for the atmosphere. By studying several key variables for Air Quality (surface and low troposphere concentrations of ozone, nitrogen oxides, volatile organic compounds, radicals, PM,...), we investigated the indicators that are robust, through averages over several years, (monthly averages, frequency of exceedances, AOTs, ...) for a given climate when using climatological forcings instead of analyses, which constitutes the reference. Both

  15. Driving Parameters for Distributed and Centralized Air Transportation Architectures

    NASA Technical Reports Server (NTRS)

    Feron, Eric

    2001-01-01

    This report considers the problem of intersecting aircraft flows under decentralized conflict avoidance rules. Using an Eulerian standpoint (aircraft flow through a fixed control volume), new air traffic control models and scenarios are defined that enable the study of long-term airspace stability problems. Considering a class of two intersecting aircraft flows, it is shown that airspace stability, defined both in terms of safety and performance, is preserved under decentralized conflict resolution algorithms. Performance bounds are derived for the aircraft flow problem under different maneuver models. Besides analytical approaches, numerical examples are presented to test the theoretical results, as well as to generate some insight about the structure of the traffic flow after resolution. Considering more than two intersecting aircraft flows, simulations indicate that flow stability may not be guaranteed under simple conflict avoidance rules. Finally, a comparison is made with centralized strategies to conflict resolution.

  16. Spatial Allocator for air quality modeling

    EPA Pesticide Factsheets

    The Spatial Allocator is a set of tools that helps users manipulate and generate data files related to emissions and air quality modeling without requiring the use of a commercial Geographic Information System.

  17. EVALUATING AND USING AIR QUALITY MODELS

    EPA Science Inventory

    Grid-based models are being used to assess the magnitude of the pollution problem and to design emission control strategies to achieve compliance with the relevant air quality standards in the United States.

  18. Effects of burstiness on the air transportation system

    NASA Astrophysics Data System (ADS)

    Ito, Hidetaka; Nishinari, Katsuhiro

    2017-01-01

    The effects of burstiness in complex networks have received considerable attention. In particular, the effects on temporal distance and delays in the air transportation system are significant owing to their huge impact on our society. Therefore, in this paper, the temporal distance of empirical U.S. flight schedule data is compared with that of regularized data without burstiness to analyze the effects of burstiness. The temporal distance is calculated by a graph analysis method considering flight delays, missed connections, flight cancellations, and congestion. In addition, we propose two temporal distance indexes based on passengers' behavior to quantify the effects. As a result, we find that burstiness reduces both the scheduled and the actual temporal distances for business travelers, while delays caused by missed connections and congestion are increased. We also find that the decrease of the scheduled temporal distance by burstiness is offset by an increase of the delays for leisure passengers. Moreover, we discover that the positive effect of burstiness is lost when flight schedules are overcrowded.

  19. Identification of terms to define unconstrained air transportation demands

    NASA Technical Reports Server (NTRS)

    Jacobson, I. D.; Kuhilhau, A. R.

    1982-01-01

    The factors involved in the evaluation of unconstrained air transportation systems were carefully analyzed. By definition an unconstrained system is taken to be one in which the design can employ innovative and advanced concepts no longer limited by present environmental, social, political or regulatory settings. Four principal evaluation criteria are involved: (1) service utilization, based on the operating performance characteristics as viewed by potential patrons; (2) community impacts, reflecting decisions based on the perceived impacts of the system; (3) technological feasibility, estimating what is required to reduce the system to practice; and (4) financial feasibility, predicting the ability of the concepts to attract financial support. For each of these criteria, a set of terms or descriptors was identified, which should be used in the evaluation to render it complete. It is also demonstrated that these descriptors have the following properties: (a) their interpretation may be made by different groups of evaluators; (b) their interpretations and the way they are used may depend on the stage of development of the system in which they are used; (c) in formulating the problem, all descriptors should be addressed independent of the evaluation technique selected.

  20. Models of inflammation: carrageenan air pouch.

    PubMed

    Duarte, Djane B; Vasko, Michael R; Fehrenbacher, Jill C

    2012-03-01

    The subcutaneous air pouch is an in vivo model that can be used to study acute and chronic inflammation, the resolution of the inflammatory response, and the oxidative stress response. Injection of irritants into an air pouch in rats or mice induces an inflammatory response that can be quantified by the volume of exudate produced, the infiltration of cells, and the release of inflammatory mediators. The model presented in this unit has been extensively used to identify potential anti-inflammatory drugs.

  1. Some considerations for air transportation analysis to non-urban areas.

    NASA Technical Reports Server (NTRS)

    Norman, S. D.

    1973-01-01

    Review of some of the problems associated with air transportation to and from nonurban areas. While a significant proportion of public transportation needs of nonurban areas are met by aircraft, there are indications that improvement in air transportation service are called for and would be rewarded by increased patronage. However, subsidized local service carriers are attracted by large aircraft operation, and there is a tendency to discontinue service to low density areas. Prospects and potential means for reversing this trend are discussed.

  2. Cost/benefit trade-offs for reducing the energy consumption of commercial air transportation (RECAT)

    NASA Technical Reports Server (NTRS)

    Gobetz, F. W.; Dubin, A. P.

    1976-01-01

    A study has been performed to evaluate the opportunities for reducing the energy requirements of the U.S. domestic air passenger transport system through improved operational techniques, modified in-service aircraft, derivatives of current production models, or new aircraft using either current or advanced technology. Each of the fuel-conserving alternatives has been investigated individually to test its potential for fuel conservation relative to a hypothetical baseline case in which current, in-production aircraft types are assumed to operate, without modification and with current operational techniques, into the future out to the year 2000.

  3. 75 FR 50708 - Approval and Promulgation of Air Quality Implementation Plans; Indiana; Transportation Conformity...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-17

    ...; Transportation Conformity Consultation Requirement AGENCY: Environmental Protection Agency (EPA). ACTION: Direct... ``Transportation Conformity.'' This approval will meet a requirement of the Clean Air Act (Act) and EPA's Transportation Conformity regulations. DATES: This direct final rule will be effective October 18, 2010,...

  4. Managing the Drivers of Air Flow and Water Vapor Transport in Existing Single Family Homes (Revised)

    SciTech Connect

    Cummings, J.; Withers, C.; Martin, E.; Moyer, N.

    2012-10-01

    This document focuses on managing the driving forces which move air and moisture across the building envelope. While other previously published Measure Guidelines focus on elimination of air pathways, the ultimate goal of this Measure Guideline is to manage drivers which cause air flow and water vapor transport across the building envelope (and also within the home), control air infiltration, keep relative humidity (RH) within acceptable limits, avoid combustion safety problems, improve occupant comfort, and reduce house energy use.

  5. Two-point model for divertor transport

    SciTech Connect

    Galambos, J.D.; Peng, Y.K.M.

    1984-04-01

    Plasma transport along divertor field lines was investigated using a two-point model. This treatment requires considerably less effort to find solutions to the transport equations than previously used one-dimensional (1-D) models and is useful for studying general trends. It also can be a valuable tool for benchmarking more sophisticated models. The model was used to investigate the possibility of operating in the so-called high density, low temperature regime.

  6. The Impact of Physical Atmosphere on Air Quality and the Utility of Satellite Observations in Air Quality Models

    NASA Astrophysics Data System (ADS)

    Pour Biazar, A.; McNider, R. T.; Park, Y. H.; Doty, K.; Khan, M. N.; Dornblaser, B.

    2012-12-01

    Physical atmosphere significantly impacts air quality as it regulates production, accumulation, and transport of atmospheric pollutants. Consequently, air quality simulations are greatly influenced by the uncertainties that emanates from the simulation of physical atmosphere. Since air quality model predictions are increasingly being used in health studies, regulatory applications, and policy making, reducing such uncertainties in model simulations is of outmost importance. This paper describes some of the critical aspects of physical atmosphere affecting air quality models that can be improved by utilizing satellite observations. Retrievals of skin temperature, surface albedo, surface insolation, cloud top temperature and cloud reflectance obtained from the Geostationary Operational Environmental Satellite (GOES) by NASA/MSFC GOES Product Generation System (GPGS) have been utilized to improve the air quality simulations used in the State Implementation Plan (SIP) attainment demonstrations. Satellite observations of ground temperature are used to recover surface moisture and heat capacity and thereby improving model simulation of air temperature. Observations of clouds are utilized to improve the photochemical reaction rates within the photochemical model and also to assimilate clouds in the meteorological model. These techniques have been implemented and tested in some of the widely used air quality decision modeling systems such as MM5/WRF/CMAQ/CAMx. The results from these activities show significant improvements in air quality simulations.

  7. Modeling of global surface air temperature

    NASA Astrophysics Data System (ADS)

    Gusakova, M. A.; Karlin, L. N.

    2012-04-01

    A model to assess a number of factors, such as total solar irradiance, albedo, greenhouse gases and water vapor, affecting climate change has been developed on the basis of Earth's radiation balance principle. To develop the model solar energy transformation in the atmosphere was investigated. It's a common knowledge, that part of the incoming radiation is reflected into space from the atmosphere, land and water surfaces, and another part is absorbed by the Earth's surface. Some part of outdoing terrestrial radiation is retained in the atmosphere by greenhouse gases (carbon dioxide, methane, nitrous oxide) and water vapor. Making use of the regression analysis a correlation between concentration of greenhouse gases, water vapor and global surface air temperature was obtained which, it is turn, made it possible to develop the proposed model. The model showed that even smallest fluctuations of total solar irradiance intensify both positive and negative feedback which give rise to considerable changes in global surface air temperature. The model was used both to reconstruct the global surface air temperature for the 1981-2005 period and to predict global surface air temperature until 2030. The reconstructions of global surface air temperature for 1981-2005 showed the models validity. The model makes it possible to assess contribution of the factors listed above in climate change.

  8. Effects of transportation on energy and air quality. Transportation research record

    SciTech Connect

    1997-11-01

    Partial Contents: Alternative Fuel Vehicle Programs: Applicability of Government Incentives; Transitional Alternative Fuels and Vehicles Model; Forecasting Cost Path of Electric Vehicle Drive System: Monte Carlo Experience Curve Simulation; Another Way to Go. Some Implications of Light-duty Diesel Strategy; Use of Episodic Controls to Reduce Frequency and Severity of Air Pollution Events; Conformity: Long-Term Prognoses for Selected Ozone Nonattainment Areas in California; Development of Comprehensive Modal Emissions Model: Operating Under Hot-Stabilized Conditions; and Implications of Transient Mode Duration for Spatially Disaggregated High-Resolution Emission Inventory Studies.

  9. Uncertainty in tsunami sediment transport modeling

    USGS Publications Warehouse

    Jaffe, Bruce E.; Goto, Kazuhisa; Sugawara, Daisuke; Gelfenbaum, Guy R.; La Selle, SeanPaul M.

    2016-01-01

    Erosion and deposition from tsunamis record information about tsunami hydrodynamics and size that can be interpreted to improve tsunami hazard assessment. We explore sources and methods for quantifying uncertainty in tsunami sediment transport modeling. Uncertainty varies with tsunami, study site, available input data, sediment grain size, and model. Although uncertainty has the potential to be large, published case studies indicate that both forward and inverse tsunami sediment transport models perform well enough to be useful for deciphering tsunami characteristics, including size, from deposits. New techniques for quantifying uncertainty, such as Ensemble Kalman Filtering inversion, and more rigorous reporting of uncertainties will advance the science of tsunami sediment transport modeling. Uncertainty may be decreased with additional laboratory studies that increase our understanding of the semi-empirical parameters and physics of tsunami sediment transport, standardized benchmark tests to assess model performance, and development of hybrid modeling approaches to exploit the strengths of forward and inverse models.

  10. California air transportation study: A transportation system for the California Corridor of the year 2010

    NASA Technical Reports Server (NTRS)

    1989-01-01

    To define and solve the problems of transportation in the California Corrider in the year 2010, the 1989 California Polytechnic State University Aeronautical Engineering Senior Design class determined future corridor transportation needs and developed a system to meet the requirements. A market study, which included interpreting travel demand and gauging the future of regional and national air travel in and out of the corridor, allowed the goals of the project to be accurately refined. Comprehensive trade-off studies of several proposed transporation systems were conducted to determine which components would form the final proposed system. Preliminary design and further analysis were performed for each resulting component. The proposed system consists of three vehicles and a special hub or mode mixer, the Corridor Access Port (CAP). The vehicles are: (1) an electric powered aircraft to serve secondary airports and the CAP; (2) a high speed magnetic levitation train running through the CAP and the high population density areas of the corridor; and (3) a vertical takeoff and landing tilt rotor aircraft to serve both intercity and intrametropolitan travelers from the CAP and city vertiports. The CAP is a combination and an extension of the hub, mode mixer, and Wayport concepts. The CAP is an integrated part of the system which meets the travel demands in the corridor, and interfaces with interstate and international travel.

  11. Charge-transport model for conducting polymers

    NASA Astrophysics Data System (ADS)

    Dongmin Kang, Stephen; Jeffrey Snyder, G.

    2016-11-01

    The growing technological importance of conducting polymers makes the fundamental understanding of their charge transport extremely important for materials and process design. Various hopping and mobility edge transport mechanisms have been proposed, but their experimental verification is limited to poor conductors. Now that advanced organic and polymer semiconductors have shown high conductivity approaching that of metals, the transport mechanism should be discernible by modelling the transport like a semiconductor with a transport edge and a transport parameter s. Here we analyse the electrical conductivity and Seebeck coefficient together and determine that most polymers (except possibly PEDOT:tosylate) have s = 3 and thermally activated conductivity, whereas s = 1 and itinerant conductivity is typically found in crystalline semiconductors and metals. The different transport in polymers may result from the percolation of charge carriers from conducting ordered regions through poorly conducting disordered regions, consistent with what has been expected from structural studies.

  12. Effects of the Air Traffic Control System on the Supersonic Transport

    NASA Technical Reports Server (NTRS)

    Silsby, Norman S.; McLaughlin, Milton D.; Fischer, Michael C.

    1965-01-01

    A study of the problems anticipated with the introduction of the supersonic transport into the air traffic control system indicated that supersonic transport design allowances for time and fuel for maneuvering during climbouts may not be sufficient, that there is a greater communications-navigation work- load for the supersonic transport than for the subsonic jet transport during descent, and that use of a flight director to command pitch control guidance for the pilot would be helpful.

  13. Offline tracer transport modeling with global WRF model data

    NASA Astrophysics Data System (ADS)

    Belikov, Dmitry; Maksytov, Shamil; Zaripov, Radomir; Bart, Andrey; Starchenko, Alexander

    2013-04-01

    This work describes the one-way coupling between a global configuration of the Weather Research and Forecasting (WRF) weather prediction model (http://wrf-model.org/) and the National Institute for Environmental Studies (NIES) three-dimensional offline chemical transport model (version NIES-08.1i). The primary motivation for developing this coupled model has been to reduce transport errors in global-scale simulation of greenhouse gases through a more detailed description of the meteorological conditions. We have implemented a global configuration of WRF model (version 3.4.1, ARW core) with 2.5 degree horizontal resolution and 32 vertical levels. The WRF model was driving with NCEP Final Analysis (FNL) reanalysis using combined techniques: FDDA + Cyclic Incremental Correction (like in intermittent data assimilation). Time-averaged mass-coupled horizontal velocities on sigma levels with approach supposed by Nehrkorn et al. (2010) are calculated to drive NIES TM. The NIES TM is designed to simulate natural and anthropogenic synoptic-scale variations in atmospheric constituents at diurnal, seasonal and interannual timescales. The model uses a mass-conservative flux-form formulation that consists of a third-order van Leer advection scheme and a horizontal dry-air mass flux correction. The horizontal latitude-longitude grid is a reduced rectangular grid (i.e., the grid size is doubled several times approaching the poles), with an initial spatial resolution of 2.5 deg x 2.5 deg and 32 vertical levels from the surface up to the level of 3 hPa. A simulations of the atmospheric tracer are used to evaluate the performance of the coupled WRF-NIES model. Simulated distributions are validated against in situ observations and compared with output from "standard" version of NIES TM driven by the Japanese 25-year Reanalysis/the Japan Meteorological Agency Climate Data Assimilation System (JRA-25/JCDAS) dataset. Fields calculated by WRF and used to drive NIES TM were also evaluated

  14. Modeling urban air pollution with optimized hierarchical fuzzy inference system.

    PubMed

    Tashayo, Behnam; Alimohammadi, Abbas

    2016-10-01

    Environmental exposure assessments (EEA) and epidemiological studies require urban air pollution models with appropriate spatial and temporal resolutions. Uncertain available data and inflexible models can limit air pollution modeling techniques, particularly in under developing countries. This paper develops a hierarchical fuzzy inference system (HFIS) to model air pollution under different land use, transportation, and meteorological conditions. To improve performance, the system treats the issue as a large-scale and high-dimensional problem and develops the proposed model using a three-step approach. In the first step, a geospatial information system (GIS) and probabilistic methods are used to preprocess the data. In the second step, a hierarchical structure is generated based on the problem. In the third step, the accuracy and complexity of the model are simultaneously optimized with a multiple objective particle swarm optimization (MOPSO) algorithm. We examine the capabilities of the proposed model for predicting daily and annual mean PM2.5 and NO2 and compare the accuracy of the results with representative models from existing literature. The benefits provided by the model features, including probabilistic preprocessing, multi-objective optimization, and hierarchical structure, are precisely evaluated by comparing five different consecutive models in terms of accuracy and complexity criteria. Fivefold cross validation is used to assess the performance of the generated models. The respective average RMSEs and coefficients of determination (R (2)) for the test datasets using proposed model are as follows: daily PM2.5 = (8.13, 0.78), annual mean PM2.5 = (4.96, 0.80), daily NO2 = (5.63, 0.79), and annual mean NO2 = (2.89, 0.83). The obtained results demonstrate that the developed hierarchical fuzzy inference system can be utilized for modeling air pollution in EEA and epidemiological studies.

  15. Modeling monthly mean air temperature for Brazil

    NASA Astrophysics Data System (ADS)

    Alvares, Clayton Alcarde; Stape, José Luiz; Sentelhas, Paulo Cesar; de Moraes Gonçalves, José Leonardo

    2013-08-01

    Air temperature is one of the main weather variables influencing agriculture around the world. Its availability, however, is a concern, mainly in Brazil where the weather stations are more concentrated on the coastal regions of the country. Therefore, the present study had as an objective to develop models for estimating monthly and annual mean air temperature for the Brazilian territory using multiple regression and geographic information system techniques. Temperature data from 2,400 stations distributed across the Brazilian territory were used, 1,800 to develop the equations and 600 for validating them, as well as their geographical coordinates and altitude as independent variables for the models. A total of 39 models were developed, relating the dependent variables maximum, mean, and minimum air temperatures (monthly and annual) to the independent variables latitude, longitude, altitude, and their combinations. All regression models were statistically significant ( α ≤ 0.01). The monthly and annual temperature models presented determination coefficients between 0.54 and 0.96. We obtained an overall spatial correlation higher than 0.9 between the models proposed and the 16 major models already published for some Brazilian regions, considering a total of 3.67 × 108 pixels evaluated. Our national temperature models are recommended to predict air temperature in all Brazilian territories.

  16. Thermodynamic and transport properties of air/water mixtures

    NASA Technical Reports Server (NTRS)

    Fessler, T. E.

    1981-01-01

    Subroutine WETAIR calculates properties at nearly 1,500 K and 4,500 atmospheres. Necessary inputs are assigned values of combinations of density, pressure, temperature, and entropy. Interpolation of property tables obtains dry air and water (steam) properties, and simple mixing laws calculate properties of air/water mixture. WETAIR is used to test gas turbine engines and components operating in relatively humid air. Program is written in SFTRAN and FORTRAN.

  17. Impact of Clean Air Act Regulations on Nitrogen Fate and Transport in the Neuse River Basin

    NASA Astrophysics Data System (ADS)

    Gabriel, M. C.; Knightes, C. D.; Dennis, R. L.; Cooter, E. J.

    2012-12-01

    This study investigated impacts of Clean Air Act Amendment (CAAA) NOx emissions regulations on the fate and transport of nitrogen for two watersheds in the Neuse River Basin, North Carolina, USA from 1990 to 2020. The Soil and Water Assessment Tool (SWAT) and the Community Multi-scale Air Quality (CMAQ) modeling system were used. CMAQ simulated atmospheric chemical transport and nitrogen deposition. This data was entered into SWAT which simulated watershed hydrology and water quality. Two cases were investigated: one that incorporates CAAA regulatory emissions controls in CMAQ simulation (with) and a second case that does not (without). SWAT model results forecasted a 70% decrease in inorganic nitrogen discharge from the Little River watershed and a 50% decrease for the Nahunta watershed by 2020 under the emission control (with) scenario. Denitrification and plant nitrogen uptake played important roles in nitrogen discharge from each watershed. The nitrogen discharge response time following a change in atmospheric nitrogen deposition was 4 years for the Nahunta watershed and 2 years for the Little River watershed. The longer response time for Nahunta is primarily due to a higher percentage of soybean land cover (22.5% [Nahunta]; 1.6% [Little River]). Agricultural land covers had varied nitrogen response times to changes in atmospheric deposition, particularly for soybean, hay and corn. The studied watersheds retained >80% of all nitrogen delivered by agriculture fertilization, biological fixation and atmospheric deposition.

  18. Journal of Air Transportation World Wide, Volume 2, No. 1. Volume 2

    NASA Technical Reports Server (NTRS)

    Bowen, Brent (Editor)

    1997-01-01

    The Journal of Air Transportation World Wide's (JATWW) mission is to provide the global community immediate key resource information in all areas of air transportation. Our goal is to be recognized as the preeminent scholarly journal in the aeronautical aspects of transportation. As an international and interdisciplinary journal, the JATWW will provide a forum for peer-reviewed articles in all areas of aviation and space transportation research, policy, theory, case study, practice, and issues. While maintaining a broad scope, a key focal point of the journal will be in the area of aviation administration and policy.

  19. Journal of Air Transportation World Wide, Volume 4, No. 2. Volume 4

    NASA Technical Reports Server (NTRS)

    Bowen, Brent D. (Editor); Kabashkin, Igor (Editor)

    1999-01-01

    The Journal of Air Transportation World Wide's (JATWW) mission is to provide the global community immediate key resource information in all areas of air transportation. The goal of the Journal is to be recognized as the preeminent scholarly journal in the aeronautical aspects of transportation. As an international and interdisciplinary journal, the JATWW will provide a forum for peer-reviewed articles in all areas of aviation and space transportation research, policy, theory, case study, practice, and issues. While maintaining a broad scope, a focal point of the journal will be in the area of aviation administration and policy.

  20. Journal of Air Transportation World Wide, Volume 5, No. 2. Volume 5, No. 2

    NASA Technical Reports Server (NTRS)

    Browen, Brent D.

    2000-01-01

    The Journal of Air Transportation World Wide's (JATWW) mission is to provide the global community immediate key resource information in all areas of air transportation. Our goal is to be recognized as the preeminent scholarly journal in the aeronautical aspects of transportation. As an international and interdisciplinary journal, the JATWW will provide a forum for peer-reviewed articles in all areas of aviation and space transportation research, policy, theory, case study, practice, and issues. While maintaining a broad scope, a focal point of the journal will be in the area of aviation administration and policy.

  1. Journal of Air Transportation World Wide, Volume 3, No. 1. Volume 3

    NASA Technical Reports Server (NTRS)

    Bowen, Brent D. (Editor)

    1998-01-01

    The Journal of Air Transportation World Wide's (JATWW) mission is to provide the global community immediate key resource information in all areas of air transportation. Our goal is to be recognized as the preeminent scholarly journal in the aeronautical aspects of transportation. As an international and interdisciplinary journal, the JATWW will provide a forum for peer-reviewed articles in all areas of aviation and space transportation research, policy, theory, case study, practice, and issues. While maintaining a broad scope, a focal point of the journal will be in the area of aviation administration and policy.

  2. Air target models for fuzing simulations

    NASA Astrophysics Data System (ADS)

    Dammann, J. F., Jr.

    1982-09-01

    Radar backscatter models for air targets suitable for computer simulation of radar fuze-air target encounters are described. These models determine the characteristics of the energy reflected to the fuze when the target is illuminated by a fuze radar. When the target models are coupled with fuze models, the time when the fuze detects the presence of the target can be determined for any arbitrary terminal encounter geometry. Fuze detection times for representative trajectories can be compared with fuze specifications to measure fuze performance or can be used as a part of a simulation of an entire system to determine system performance. Following one basic methodology, target models have been written for the Fishbed, Foxbat, and Flogger fighter aircraft; the Hind-D helicopter; and the Backfire, Blinder, and B-1 bombers. All of the models are specular point models where the major return is assumed to come from a small number of glitter points or specular points on the target.

  3. Anomalous transport modelling of tokamak plasmas

    SciTech Connect

    Kinsey, J.; Singer, C.; Malone, G.; Tiouririne, N.

    1992-12-31

    Theory based transport simulations of DIII-D, JET, ITER are compared to experimental data using a combination of anamolous transport models. The Multiple-mode Transport Model is calibrated to a give set of L-mode and H-mode discharges with an emphasis on testing the adequacy of anomalous flux contributions from drift/{eta}{sub i} and resistive ballooning mode theories. A survey of possible additions and/or alternatives to the model from recent theories on neoclassical MHD effects, hot ion modes, circulating electron modes, and high-m tearing modes is also included.

  4. Anomalous transport modelling of tokamak plasmas

    SciTech Connect

    Kinsey, J.; Singer, C.; Malone, G.; Tiouririne, N.

    1992-01-01

    Theory based transport simulations of DIII-D, JET, ITER are compared to experimental data using a combination of anamolous transport models. The Multiple-mode Transport Model is calibrated to a give set of L-mode and H-mode discharges with an emphasis on testing the adequacy of anomalous flux contributions from drift/[eta][sub i] and resistive ballooning mode theories. A survey of possible additions and/or alternatives to the model from recent theories on neoclassical MHD effects, hot ion modes, circulating electron modes, and high-m tearing modes is also included.

  5. Pan American Airways/Naval Air Transport Service/destroyer base site showing stone ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Pan American Airways/Naval Air Transport Service/destroyer base site showing stone wall around patio. View facing east-southeast. - U.S. Naval Base, Pearl Harbor, Pearl City Peninsula, Pearl City, Honolulu County, HI

  6. Pan American Airways/Naval Air Transport Service/destroyer base site showing brick ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Pan American Airways/Naval Air Transport Service/destroyer base site showing brick and concrete paving of patio, and circular planters. View facing east. - U.S. Naval Base, Pearl Harbor, Pearl City Peninsula, Pearl City, Honolulu County, HI

  7. Transport properties of high-temperature air in a magnetic field

    SciTech Connect

    Bruno, D.; Capitelli, M.; Catalfamo, C.; Giordano, D.

    2011-01-15

    Transport properties of equilibrium air plasmas in a magnetic field are calculated with the Chapman-Enskog method. The range considered for the temperature is [50-50 000] K and for the magnetic induction is [0-300] T.

  8. Regional Air Transport in Europe: The Potential Role of the Civil Tiltrotor in Reducing Airside Congestion

    NASA Technical Reports Server (NTRS)

    Correnti, Vincenzo; Ignaccolo, Matteo; Capri, Salvatore; Inturri, Giuseppe

    2006-01-01

    The volume of air traffic worldwide is still in constant growth despite unfair events that sometimes occur. The demand for regional air transport is also increasing, thanks in part to the use of new vehicles purposely designed for short range flights which make this means of transport more attractive than in the past. This paper studies the possibility of using aircraft capable of vertical or short takeoff or landing (V/STOL), in particular the tiltrotor, in the regional air transport market and the impact on airport capacity that the use of this craft would have. With this in mind the advantages and disadvantages of using this vehicle are identified, as well as the changes to be made to the air transport system in order to exploit its full potential.

  9. The Importance of Moving Air-Water Interfaces for Colloid Transport in Porous Media

    NASA Astrophysics Data System (ADS)

    Flury, M.

    2015-12-01

    In the vadose zone, or in unsaturated porous media in general, transport of colloids is usually less pronounced than in groundwater. An important retention mechanism for colloids in unsaturated porous media is attachment to air-water interfaces. However, air-water interfaces can also lead to colloid mobilization and enhanced transport if air-water interfaces are moving, such as during infiltration, imbibition, and drainage. Colloid attachment to air-water interfaces is caused by surface tension forces, and these forces usually exceed other interactions forces; therefore, surface tension forces play a dominant role for colloid transport in unsaturated porous media. In this presentation, experimental and theoretical evidence of surface tension forces acting on colloids will be presented, and the role of moving air-water interfaces will be discussed.

  10. Influence of Transport on Two-Dimensional Model Simulation. Tracer Sensitivity to 2-D Model Transport. 1; Long Lived Tracers

    NASA Technical Reports Server (NTRS)

    Fleming, Eric L.; Jackman, Charles H.; Considine, David B.; Stolarski, Richard S.

    1999-01-01

    In this study, we examine the sensitivity of long lived tracers to changes in the base transport components in our 2-D model. Changes to the strength of the residual circulation in the upper troposphere and stratosphere and changes to the lower stratospheric K(sub zz) had similar effects in that increasing the transport rates decreased the overall stratospheric mean age, and increased the rate of removal of material from the stratosphere. Increasing the stratospheric K(sub yy) increased the mean age due to the greater recycling of air parcels through the middle atmosphere, via the residual circulation, before returning to the troposphere. However, increasing K(sub yy) along with self-consistent increases in the corresponding planetary wave drive, which leads to a stronger residual circulation, more than compensates for the K(sub yy)-effect, and produces significantly younger ages throughout the stratosphere. Simulations with very small tropical stratospheric K(sub yy) decreased the globally averaged age of air by as much as 25% in the middle and upper stratosphere, and resulted in substantially weaker vertical age gradients above 20 km in the extratropics. We found only very small stratospheric tracer sensitivity to the magnitude of the horizontal mixing across the tropopause, and to the strength of the mesospheric gravity wave drag and diffusion used in the model. We also investigated the transport influence on chemically active tracers and found a strong age-tracer correlation, both in concentration and calculated lifetimes. The base model transport gives the most favorable overall comparison with a variety of inert tracer observations, and provides a significant improvement over our previous 1995 model transport. Moderate changes to the base transport were found to provide modest agreement with some of the measurements. Transport scenarios with residence times ranging from moderately shorter to slightly longer relative to the base case simulated N2O lifetimes

  11. Models of Inflammation: Carrageenan Air Pouch.

    PubMed

    Duarte, Djane B; Vasko, Michael R; Fehrenbacher, Jill C

    2016-03-18

    The subcutaneous air pouch is an in vivo model that can be used to study the components of acute and chronic inflammation, the resolution of the inflammatory response, the oxidative stress response, and potential therapeutic targets for treating inflammation. Injection of irritants into an air pouch in rats or mice induces an inflammatory response that can be quantified by the volume of exudate produced, the infiltration of cells, and the release of inflammatory mediators. The model presented in this unit has been extensively used to identify potential anti-inflammatory drugs.

  12. The Conference Proceedings of the 2003 Air Transport Research Society (ATRS) World Conference, Volume 3

    NASA Technical Reports Server (NTRS)

    Bowen, Brent (Editor); Gudmundsson, Sveinn (Editor); Oum, Tae (Editor)

    2003-01-01

    Volume 3 of the 2003 Air Transport Reserch Society (ATRS) World Conference includes papers on topics relevant to airline operations worldwide. Specific topics include: European Union and civil aviation regimens;simulating decision making in airline operations, passenger points of view on convenient airports; route monopolies and nonlinear pricing; cooperation among airports in Europe; fleet modernizaiton in Brazil;the effects of deregulation on the growth of air transportation in Europe and the United States.

  13. Study of Tranexamic Acid During Air Medical Prehospital Transport Trial (STAAMP trial)

    DTIC Science & Technology

    2015-10-01

    AWARD NUMBER: W81XWH-13-2-0080 TITLE: Study of Tranexamic Acid During Air Medical Prehospital Transport Trial (STAAMP trial) PRINCIPAL INVESTIGATOR...TITLE AND SUBTITLE 5a. CONTRACT NUMBER Study of Tranexamic Acid During Air Medical Prehospital Transport Trial (STAAMP trial) 5b. GRANT NUMBER W81XWH...IRB approval regarding changes to the protocol language. 15. SUBJECT TERMS Prehospital; Tranexamic acid 16. SECURITY CLASSIFICATION OF: 17. LIMITATION

  14. Polar auxin transport: models and mechanisms.

    PubMed

    van Berkel, Klaartje; de Boer, Rob J; Scheres, Ben; ten Tusscher, Kirsten

    2013-06-01

    Spatial patterns of the hormone auxin are important drivers of plant development. The observed feedback between the active, directed transport that generates auxin patterns and the auxin distribution that influences transport orientation has rendered this a popular subject for modelling studies. Here we propose a new mathematical framework for the analysis of polar auxin transport and present a detailed mathematical analysis of published models. We show that most models allow for self-organised patterning for similar biological assumptions, and find that the pattern generated is typically unidirectional, unless additional assumptions or mechanisms are incorporated. Our analysis thus suggests that current models cannot explain the bidirectional fountain-type patterns found in plant meristems in a fully self-organised manner, and we discuss future research directions to address the gaps in our understanding of auxin transport mechanisms.

  15. Highway and interline transportation routing models

    SciTech Connect

    Joy, D.S.; Johnson, P.E.

    1994-06-01

    The potential impacts associated with the transportation of hazardous materials are important issues to shippers, carriers, and the general public. Since transportation routes are a central characteristic in most of these issues, the prediction of likely routes is the first step toward the resolution of these issues. In addition, US Department of Transportation requirements (HM-164) mandate specific routes for shipments of highway controlled quantities of radioactive materials. In response to these needs, two routing models have been developed at Oak Ridge National Laboratory under the sponsorship of the U.S. Department of Energy (DOE). These models have been designated by DOE`s Office of Environmental Restoration and Waste Management, Transportation Management Division (DOE/EM) as the official DOE routing models. Both models, HIGHWAY and INTERLINE, are described.

  16. Mathematical modeling plasma transport in tokamaks

    SciTech Connect

    Quiang, Ji

    1997-01-01

    In this work, the author applied a systematic calibration, validation and application procedure based on the methodology of mathematical modeling to international thermonuclear experimental reactor (ITER) ignition studies. The multi-mode plasma transport model used here includes a linear combination of drift wave branch and ballooning branch instabilities with two a priori uncertain constants to account for anomalous plasma transport in tokamaks. A Bayesian parameter estimation method is used including experimental calibration error/model offsets and error bar rescaling factors to determine the two uncertain constants in the transport model with quantitative confidence level estimates for the calibrated parameters, which gives two saturation levels of instabilities. This method is first tested using a gyroBohm multi-mode transport model with a pair of DIII-D discharge experimental data, and then applied to calibrating a nominal multi-mode transport model against a broad database using twelve discharges from seven different tokamaks. The calibrated transport model is then validated on five discharges from JT-60 with no adjustable constants. The results are in a good agreement with experimental data. Finally, the resulting class of multi-mode tokamak plasma transport models is applied to the transport analysis of the ignition probability in a next generation machine, ITER. A reference simulation of basic ITER engineering design activity (EDA) parameters shows that a self-sustained thermonuclear burn with 1.5 GW output power can be achieved provided that impurity control makes radiative losses sufficiently small at an average plasma density of 1.2 X 1020/m3 with 50 MW auxiliary heating. The ignition probability of ITER for the EDA parameters, can be formally as high as 99.9% in the present context. The same probability for concept design activity (CDA) parameters of ITER, which has smaller size and lower current, is only 62.6%.

  17. Modeling Air Traffic Management Technologies with a Queuing Network Model of the National Airspace System

    NASA Technical Reports Server (NTRS)

    Long, Dou; Lee, David; Johnson, Jesse; Gaier, Eric; Kostiuk, Peter

    1999-01-01

    This report describes an integrated model of air traffic management (ATM) tools under development in two National Aeronautics and Space Administration (NASA) programs -Terminal Area Productivity (TAP) and Advanced Air Transport Technologies (AATT). The model is made by adjusting parameters of LMINET, a queuing network model of the National Airspace System (NAS), which the Logistics Management Institute (LMI) developed for NASA. Operating LMINET with models of various combinations of TAP and AATT will give quantitative information about the effects of the tools on operations of the NAS. The costs of delays under different scenarios are calculated. An extension of Air Carrier Investment Model (ACIM) under ASAC developed by the Institute for NASA maps the technologies' impacts on NASA operations into cross-comparable benefits estimates for technologies and sets of technologies.

  18. An integrative assessment of the commercial air transportation system via adaptive agents

    NASA Astrophysics Data System (ADS)

    Lim, Choon Giap

    The overarching research objective is to address the tightly-coupled interactions between the demand-side and supply-side components of the United States Commercial Air Transportation System (CATS) in a time-variant environment. A system-of-system perspective is adopted, where the scope is extended beyond the National Airspace System (NAS) level to the National Transportation System (NTS) level to capture the intermodal and multimodal relationships between the NTS stakeholders. The Agent-Based Modeling and Simulation technique is employed where the NTS/NAS is treated as an integrated Multi-Agent System comprising of consumer and service provider agents, representing the demand-side and supply-side components respectively. Successful calibration and validation of both model components against the observable real world data resulted in a CATS simulation tool where the aviation demand is estimated from socioeconomic and demographic properties of the population instead of merely based on enplanement growth multipliers. This valuable achievement enabled a 20-year outlook simulation study to investigate the implications of a global fuel price hike on the airline industry and the U.S. CATS at large. Simulation outcomes revealed insights into the airline competitive behaviors and the subsequent responses from transportation consumers.

  19. BRYNTRN: A baryon transport model

    NASA Technical Reports Server (NTRS)

    Wilson, John W.; Townsend, Lawrence W.; Nealy, John E.; Chun, Sang Y.; Hong, B. S.; Buck, Warren W.; Lamkin, S. L.; Ganapol, Barry D.; Khan, Ferdous; Cucinotta, Francis A.

    1989-01-01

    The development of an interaction data base and a numerical solution to the transport of baryons through an arbitrary shield material based on a straight ahead approximation of the Boltzmann equation are described. The code is most accurate for continuous energy boundary values, but gives reasonable results for discrete spectra at the boundary using even a relatively coarse energy grid (30 points) and large spatial increments (1 cm in H2O). The resulting computer code is self-contained, efficient and ready to use. The code requires only a very small fraction of the computer resources required for Monte Carlo codes.

  20. 76 FR 52731 - On-Line Complaint Form for Service-Related Issues in Air Transportation

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-23

    ... Office of the Secretary On-Line Complaint Form for Service-Related Issues in Air Transportation AGENCY... public to electronically submit aviation service-related complaints against air carriers. DATES: Comments... U.S.C., Subtitle VII, to investigate and enforce consumer protection and civil rights laws...

  1. 14 CFR Sec. 19-5 - Air transport traffic and capacity elements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... AIR CARRIERS Operating Statistics Classifications Sec. 19-5 Air transport traffic and capacity elements. (a) Within each of the service classifications prescribed in section -19-4, data shall be... equipment. The number of days that aircraft owned or acquired through rental or lease (but not...

  2. Aerosol properties and radiative forcing for three air masses transported in Summer 2011 to Sopot, Poland

    NASA Astrophysics Data System (ADS)

    Rozwadowska, Anna; Stachlewska, Iwona S.; Makuch, P.; Markowicz, K. M.; Petelski, T.; Strzałkowska, A.; Zieliński, T.

    2013-05-01

    Properties of atmospheric aerosols and solar radiation reaching the Earth's surface were measured during Summer 2011 in Sopot, Poland. Three cloudless days, characterized by different directions of incoming air-flows, which are typical transport pathways to Sopot, were used to estimate a radiative forcing due to aerosols present in each air mass.

  3. Stochastic model of radioiodine transport

    SciTech Connect

    Schwarz, G.; Hoffman, F.O.

    1980-01-01

    A research project has been underway at the Oak Ridge National Laboratory with the objective to evaluate dose assessment models and to determine the uncertainty associated with the model predictions. This has resulted in the application of methods to propagate uncertainties through models. Some techniques and results related to this problem are discussed.

  4. An air quality modeling approach to satellite remote sensing

    NASA Astrophysics Data System (ADS)

    Yang, E.; Christopher, S. A.

    2012-12-01

    We simulate visible and near-infrared reflectance of the GOES-R Advanced Baseline Imager (ABI) for cases of high aerosol loading with haze and smoke over the eastern United States. The simulations are performed using the Weather Research and Forecasting (WRF), Sparse Matrix Operator Kernel Emissions (SMOKE), and Community Multiscale Air Quality (CMAQ) models to reproduce meteorological conditions, background emissions, and chemical transport of air pollutants. Geostationary satellite-derived biomass burning emissions are also included as an input to CMAQ to fully represent aerosol loadings. Radiance is computed from the discrete ordinate atmospheric radiative transfer model. We show that the model simulations create a realistic set of reflectance in various aerosol scenarios. The simulated reflectance provides distinct spectral features of aerosols during the simulated satellite scene acquisition, which is compared to and verified with the Moderate Resolution Imaging Spectroradiometer (MODIS) true-color imagery. We also present a simple technique to synthesize green band reflectance, which will not be available on GOES-R ABI, using the model-simulated blue and red band reflectance. The model-based spectral signatures provide a simple way to select relevant and to deselect irrelevant spectral information from multispectral data. This study is an example of the use of air quality modeling in improving products and techniques for Earth observing missions.

  5. Improving the accuracy of vehicle emissions profiles for urban transportation greenhouse gas and air pollution inventories.

    PubMed

    Reyna, Janet L; Chester, Mikhail V; Ahn, Soyoung; Fraser, Andrew M

    2015-01-06

    Metropolitan greenhouse gas and air emissions inventories can better account for the variability in vehicle movement, fleet composition, and infrastructure that exists within and between regions, to develop more accurate information for environmental goals. With emerging access to high quality data, new methods are needed for informing transportation emissions assessment practitioners of the relevant vehicle and infrastructure characteristics that should be prioritized in modeling to improve the accuracy of inventories. The sensitivity of light and heavy-duty vehicle greenhouse gas (GHG) and conventional air pollutant (CAP) emissions to speed, weight, age, and roadway gradient are examined with second-by-second velocity profiles on freeway and arterial roads under free-flow and congestion scenarios. By creating upper and lower bounds for each factor, the potential variability which could exist in transportation emissions assessments is estimated. When comparing the effects of changes in these characteristics across U.S. cities against average characteristics of the U.S. fleet and infrastructure, significant variability in emissions is found to exist. GHGs from light-duty vehicles could vary by -2%-11% and CAP by -47%-228% when compared to the baseline. For heavy-duty vehicles, the variability is -21%-55% and -32%-174%, respectively. The results show that cities should more aggressively pursue the integration of emerging big data into regional transportation emissions modeling, and the integration of these data is likely to impact GHG and CAP inventories and how aggressively policies should be implemented to meet reductions. A web-tool is developed to aide cities in improving emissions uncertainty.

  6. Downward transport of ozone rich air and implications for atmospheric chemistry in the Amazon rainforest

    NASA Astrophysics Data System (ADS)

    Gerken, Tobias; Wei, Dandan; Chase, Randy J.; Fuentes, Jose D.; Schumacher, Courtney; Machado, Luiz A. T.; Andreoli, Rita V.; Chamecki, Marcelo; Ferreira de Souza, Rodrigo A.; Freire, Livia S.; Jardine, Angela B.; Manzi, Antonio O.; Nascimento dos Santos, Rosa M.; von Randow, Celso; dos Santos Costa, Patrícia; Stoy, Paul C.; Tóta, Julio; Trowbridge, Amy M.

    2016-01-01

    From April 2014 to January 2015, ozone (O3) dynamics were investigated as part of GoAmazon 2014/5 project in the central Amazon rainforest of Brazil. Just above the forest canopy, maximum hourly O3 mixing ratios averaged 20 ppbv (parts per billion on a volume basis) during the June-September dry months and 15 ppbv during the wet months. Ozone levels occasionally exceeded 75 ppbv in response to influences from biomass burning and regional air pollution. Individual convective storms transported O3-rich air parcels from the mid-troposphere to the surface and abruptly enhanced the regional atmospheric boundary layer by as much as 25 ppbv. In contrast to the individual storms, days with multiple convective systems produced successive, cumulative ground-level O3 increases. The magnitude of O3 enhancements depended on the vertical distribution of O3 within storm downdrafts and origin of downdrafts in the troposphere. Ozone mixing ratios remained enhanced for > 2 h following the passage of storms, which enhanced chemical processing of rainforest-emitted isoprene and monoterpenes. Reactions of isoprene and monoterpenes with O3 are modeled to generate maximum hydroxyl radical formation rates of 6 × 106 radicals cm-3s-1. Therefore, one key conclusion of the present study is that downdrafts of convective storms are estimated to transport enough O3 to the surface to initiate a series of reactions that reduce the lifetimes of rainforest-emitted hydrocarbons.

  7. Global Scenarios of Air Pollutant Emissions from Road Transport through to 2050

    PubMed Central

    Takeshita, Takayuki

    2011-01-01

    This paper presents global scenarios of sulphur dioxide (SO2), nitrogen oxides (NOx), and particulate matter (PM) emissions from road transport through to 2050, taking into account the potential impacts of: (1) the timing of air pollutant emission regulation implementation in developing countries; (2) global CO2 mitigation policy implementation; and (3) vehicle cost assumptions, on study results. This is done by using a global energy system model treating the transport sector in detail. The major conclusions are the following. First, as long as non-developed countries adopt the same vehicle emission standards as in developed countries within a 30-year lag, global emissions of SO2, NOx, and PM from road vehicles decrease substantially over time. Second, light-duty vehicles and heavy-duty trucks make a large and increasing contribution to future global emissions of SO2, NOx, and PM from road vehicles. Third, the timing of air pollutant emission regulation implementation in developing countries has a large impact on future global emissions of SO2, NOx, and PM from road vehicles, whereas there is a possibility that global CO2 mitigation policy implementation has a comparatively small impact on them. PMID:21845172

  8. The energy dilemma and its impact on air transportation

    NASA Technical Reports Server (NTRS)

    Dyer, C. R. (Editor); Sincoff, M. Z. (Editor); Cribbins, P. D. (Editor)

    1973-01-01

    The dimensions of the energy situation are discussed in relation to air travel. Energy conservation, fuel consumption, and combustion efficiency are examined, as well as the proposal for subsonic aircraft using hydrogen fuel.

  9. Modeling atmospheric transport to the Marshall Islands

    NASA Astrophysics Data System (ADS)

    Merrill, John T.; Bleck, Rainer; Avila, Lixion

    1985-12-01

    Isentropic trajectory analyses are presented which support the hypothesis that atmospheric continental material found at Enewetak Atoll (11.3°N, 162.3°E) during the Sea-Air Exchange (SEAREX) experiments in 1979 had its origin primarily in Asia in the springtime (dry season experiment) and in North and Central America in the summer (wet season experiment). Fields of wind, Montgomery potential, and pressure on isentropic surfaces are obtained from global isobaric analyses by vertical interpolation. Trajectories backward in time from the area at and upwind of the experiment site were calculated using these fields. In April and May 1979 the atmospheric chemistry at Enewetak was influenced strongly by long-range transport from Asia; this transport was primarily in the potential temperature range 305-315 K with travel times of 8-13 days. Westerly winds over Asia at 350-600 mbar carry continental materials over the ocean, and as the air moves southward, subsidence occurs until the air is entrained in the trade wind flow. During July and August 1979 the transport paths were from open ocean areas and from near North and Central America at 305-310 K with travel times of 17-21 days. The trajectories remained at low levels within the boundary layer during this period. Also discussed is a meteorological analysis of dust storms in China, which shows that a mechanism exists for lifting eolian material to the upper troposphere. There is substantial uncertainty in the individual trajectories, and the factors limiting their accuracy are discussed. Given the consistency of the trajectory analyses with the chemical results, we now have a coherent picture of some of the processes responsible for long-range transport to the subtropical open ocean.

  10. 75 FR 13332 - Application of Charter Air Transport, Inc. for Commuter Authority

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-19

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF TRANSPORTATION Office of the Secretary Application of Charter Air Transport, Inc. for Commuter Authority Correction In notice document 2010-5555 appearing on page 12328 in the issue of Monday, March 15, 2010, make...

  11. 14 CFR 203.5 - Compliance as condition on operations in air transportation.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Compliance as condition on operations in air transportation. 203.5 Section 203.5 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS WAIVER OF WARSAW CONVENTION LIABILITY LIMITS AND DEFENSES § 203.5 Compliance as condition...

  12. 14 CFR 203.5 - Compliance as condition on operations in air transportation.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Compliance as condition on operations in air transportation. 203.5 Section 203.5 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS WAIVER OF WARSAW CONVENTION LIABILITY LIMITS AND DEFENSES § 203.5 Compliance as condition...

  13. 14 CFR 203.5 - Compliance as condition on operations in air transportation.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Compliance as condition on operations in air transportation. 203.5 Section 203.5 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS WAIVER OF WARSAW CONVENTION LIABILITY LIMITS AND DEFENSES § 203.5 Compliance as condition...

  14. 14 CFR 203.5 - Compliance as condition on operations in air transportation.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Compliance as condition on operations in air transportation. 203.5 Section 203.5 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS WAIVER OF WARSAW CONVENTION LIABILITY LIMITS AND DEFENSES § 203.5 Compliance as condition...

  15. 14 CFR 203.5 - Compliance as condition on operations in air transportation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Compliance as condition on operations in air transportation. 203.5 Section 203.5 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS WAIVER OF WARSAW CONVENTION LIABILITY LIMITS AND DEFENSES § 203.5 Compliance as condition...

  16. The Role of the Federal Government in the Development of the US Air Transportation System

    NASA Technical Reports Server (NTRS)

    Vittek, J. F.

    1972-01-01

    Reviewed are the roles of the various Federal agencies in the regulation, control, and development of the Air System, with major emphasis on the Department of Transportation (Office of the Secretary, Federal Aviation Administration, and National Transportation Safety Board) and the Civil Aeronautics Board.

  17. Conclusions and recommendations. [for problems in energy situation, air transportation, and hydrogen fuel

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Conclusions and recommendations are presented for an analysis of the total energy situation; the effect of the energy problem on air transportation; and hydrogen fuel for aircraft. Properties and production costs of fuels, future prediction for energy and transportation, and economic aspects of hydrogen production are appended.

  18. Molecular model of the neural dopamine transporter

    NASA Astrophysics Data System (ADS)

    Ravna, Aina Westrheim; Sylte, Ingebrigt; Dahl, Svein G.

    2003-05-01

    The dopamine transporter (DAT) regulates the action of dopamine by reuptake of the neurotransmitter into presynaptic neurons, and is the main molecular target of amphetamines and cocaine. DAT and the Na+/H+ antiporter (NhaA) are secondary transporter proteins that carry small molecules across a cell membrane against a concentration gradient, using ion gradients as energy source. A 3-dimensional projection map of the E. coli NhaA has confirmed a topology of 12 membrane spanning domains, and was previously used to construct a 3-dimensional NhaA model with 12 trans-membrane α-helices (TMHs). The NhaA model, and site directed mutagenesis data on DAT, were used to construct a detailed 3-dimensional DAT model using interactive molecular graphics and empiric force field calculations. The model proposes a dopamine transport mechanism involving TMHs 1, 3, 4, 5, 7 and 11. Asp79, Tyr252 and Tyr274 were the primary cocaine binding residues. Binding of cocaine or its analogue, (-)-2β-carbomethoxy-3β-(4-fluorophenyl)tropane (CFT), seemed to lock the transporter in an inactive state, and thus inhibit dopamine transport. The present model may be used to design further experimental studies of the molecular structure and mechanisms of DAT and other secondary transporter proteins.

  19. Air Quality Dispersion Modeling - Alternative Models

    EPA Pesticide Factsheets

    Models, not listed in Appendix W, that can be used in regulatory applications with case-by-case justification to the Reviewing Authority as noted in Section 3.2, Use of Alternative Models, in Appendix W.

  20. The cold air drainage model KLAM_21

    NASA Astrophysics Data System (ADS)

    Kossmann, M.

    2010-09-01

    A brief description of the physics and numerical techniques of the cold air drainage model KLAM_21 is presented. The model has been developed by the Deutscher Wetterdienst (Sievers, 2005) for simulations of nocturnal airflow in hilly and mountainous terrain under dry fair weather conditions. The model has been widely used as an environmental consultancy tool. Typical model applications include frost protection (cold air ponding) and air quality (nocturnal ventilation). The single-layer model calculates the depth and the mean wind of a surface based stable layer that evolves from a neutrally stratified atmosphere during nighttime. The prediction of the velocity and direction of the cold air drainage is based on vertically averaged momentum tendency equations. Temporal changes in the total heat deficit in the cold air layer are calculated from a prescribed local heat loss rate (describing turbulent and radiative cooling) and advection (donor-cell algorithm). The depth of the cold air layer (depth of the surface based temperature inversion) is calculated diagnostically from the total heat loss deficit. The model is initialised with neutral stratification at sunset (onset time of nocturnal cooling). Optionally, effects of an ambient (regional) wind and/or the dispersion of a passive tracer can be simulated. Integration over time is carried out on a regular Arakawa C grid using dynamically calculated time steps. Spatial gradients are discretised using centred differential quotients. The standard size of the computational domains can reach up to 1500 x 1500 grid cells. Grid resolutions usually range between 10 m and 500 m. High resolution simulation can be limited to a nested inner grid domain, while the courser outer domain is covering the entire airshed of interest. A friendly user interface allows easy setup, control, and evaluation of model simulations. Some selected examples of KLAM_21 applications are shown to illustrate the features and capabilities of the model

  1. Calculations and curve fits of thermodynamic and transport properties for equilibrium air to 30000 K

    NASA Technical Reports Server (NTRS)

    Gupta, Roop N.; Lee, Kam-Pui; Thompson, Richard A.; Yos, Jerrold M.

    1991-01-01

    A self-consistent set of equilibrium air values were computed for enthalpy, total specific heat at constant pressure, compressibility factor, viscosity, total thermal conductivity, and total Prandtl number from 500 to 30,000 K over a range of 10(exp -4) atm to 10(exp 2) atm. The mixture values are calculated from the transport and thermodynamic properties of the individual species provided in a recent study by the authors. The concentrations of the individual species, required in the mixture relations, are obtained from a free energy minimization calculation procedure. Present calculations are based on an 11-species air model. For pressures less than 10(exp -2) atm and temperatures of about 15,000 K and greater, the concentrations of N(++) and O(++) become important, and consequently, they are included in the calculations determining the various properties. The computed properties are curve fitted as a function of temperature at a constant value of pressure. These curve fits reproduce the computed values within 5 percent for the entire temperature range considered here at specific pressures and provide an efficient means for computing the flowfield properties of equilibrium air, provided the elemental composition remains constant at 0.24 for oxygen and 0.76 for nitrogen by mass.

  2. Reduced Dynamic Models in Epithelial Transport

    PubMed Central

    Hernández, Julio A.

    2013-01-01

    Most models developed to represent transport across epithelia assume that the cell interior constitutes a homogeneous compartment, characterized by a single concentration value of the transported species. This conception differs significantly from the current view, in which the cellular compartment is regarded as a highly crowded media of marked structural heterogeneity. Can the finding of relatively simple dynamic properties of transport processes in epithelia be compatible with this complex structural conception of the cell interior? The purpose of this work is to contribute with one simple theoretical approach to answer this question. For this, the techniques of model reduction are utilized to obtain a two-state reduced model from more complex linear models of transcellular transport with a larger number of intermediate states. In these complex models, each state corresponds to the solute concentration in an intermediate intracellular compartment. In addition, the numerical studies reveal that it is possible to approximate a general two-state model under conditions where strict reduction of the complex models cannot be performed. These results contribute with arguments to reconcile the current conception of the cell interior as a highly complex medium with the finding of relatively simple dynamic properties of transport across epithelial cells. PMID:23533397

  3. AIR QUALITY MODELING OF AMMONIA: A REGIONAL MODELING PERSPECTIVE

    EPA Science Inventory

    The talk will address the status of modeling of ammonia from a regional modeling perspective, yet the observations and comments should have general applicability. The air quality modeling system components that are central to modeling ammonia will be noted and a perspective on ...

  4. Model aids cuttings transport prediction

    SciTech Connect

    Gavignet, A.A. ); Sobey, I.J. )

    1989-09-01

    Drilling of highly deviated wells can be complicated by the formation of a thick bed of cuttings at low flow rates. The model proposed in this paper shows what mechanisms control the thickness of such a bed, and the model predictions are compared with experimental results.

  5. Air freight demand models: An overview

    NASA Technical Reports Server (NTRS)

    Dajani, J. S.; Bernstein, G. W.

    1978-01-01

    A survey is presented of some of the approaches which have been considered in freight demand estimation. The few existing continuous time computer simulations of aviation systems are reviewed, with a view toward the assessment of this approach as a tool for structuring air freight studies and for relating the different components of the air freight system. The variety of available data types and sources, without which the calibration, validation and the testing of both modal split and simulation models would be impossible are also reviewed.

  6. An air-breathing ballistic space transporter for Europe

    NASA Technical Reports Server (NTRS)

    Kramer, P. A.; Buehler, R. D.

    1985-01-01

    With increasing transport requirements, reusable space transporters again receive serious consideration in Europe as successors to the Ariane family. The paper deals with a hydrogen-ramjet-propelled, 1-1/2-stage reusable ballistic space transporter with vertical take-off and landing and using liquid hydrogen/oxygen rockets. This novel concept was developed in a theoretical study at the University of Stuttgart. The results are compared with recently published studies of several other European space transporter concepts. The data derived for the Istra - concept are: 15.4 Mg payload into low Earth-orbit, 155 Mg gross lift-off mass, 10% payload ratio, which represents a 57% propellant saving, and 44% reduction in dry mass (structure and engines) compared with comparable two-stage pure rocket concepts.

  7. Assessment of the impact of advanced air-transport technology

    NASA Technical Reports Server (NTRS)

    Maxwell, R. L.; Dickinson, L. V., Jr.

    1981-01-01

    The long term prospects for commercial supersonic transportation appear attractive enough to keep supersonic research active and reasonably healthy. On the other hand, the uncertainties surrounding an advanced supersonic transport, (AST) specifically fuel price, fuel availability and noise, are too significant to warrant an accelerated research and development program until they are better resolved. It is estimated that an AST could capture about $50 billion (1979 dollars) of the potential $150 billion in sales up to the year 2010.

  8. Assessment of China's virtual air pollution transport embodied in trade by using a consumption-based emission inventory

    NASA Astrophysics Data System (ADS)

    Zhao, H. Y.; Zhang, Q.; Guan, D. B.; Davis, S. J.; Liu, Z.; Huo, H.; Lin, J. T.; Liu, W. D.; He, K. B.

    2015-05-01

    Substantial anthropogenic emissions from China have resulted in serious air pollution, and this has generated considerable academic and public concern. The physical transport of air pollutants in the atmosphere has been extensively investigated; however, understanding the mechanisms how the pollutant was transferred through economic and trade activities remains a challenge. For the first time, we quantified and tracked China's air pollutant emission flows embodied in interprovincial trade, using a multiregional input-output model framework. Trade relative emissions for four key air pollutants (primary fine particle matter, sulfur dioxide, nitrogen oxides and non-methane volatile organic compounds) were assessed for 2007 in each Chinese province. We found that emissions were significantly redistributed among provinces owing to interprovincial trade. Large amounts of emissions were embodied in the imports of eastern regions from northern and central regions, and these were determined by differences in regional economic status and environmental policy. It is suggested that measures should be introduced to reduce air pollution by integrating cross-regional consumers and producers within national agreements to encourage efficiency improvement in the supply chain and optimize consumption structure internationally. The consumption-based air pollutant emission inventory developed in this work can be further used to attribute pollution to various economic activities and final demand types with the aid of air quality models.

  9. Analysis of operational requirements for medium density air transportation. Volume 1: Summary

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The medium density air travel market was studied to determine the aircraft design and operational requirements. The impact of operational characteristics on the air travel system and the economic viability of the study aircraft were also evaluated. Medium density is defined in terms of numbers of people transported (20 to 500 passengers per day on round trip routes), and frequency of service ( a minumium of two and maximum of eight round trips per day) for 10 regional carriers. The operational characteristics of aircraft best suited to serve the medium density air transportation market are determined and a basepoint aircraft is designed from which tradeoff studies and parametric variations could be conducted. The impact of selected aircraft on the medium density market, economics, and operations is ascertained. Research and technology objectives for future programs in medium density air transportation are identified and ranked.

  10. Importance of transboundary transport of biomass burning emissions to regional air quality in Southeast Asia

    NASA Astrophysics Data System (ADS)

    Aouizerats, B.; van der Werf, G. R.; Balasubramanian, R.; Betha, R.

    2014-05-01

    Smoke from biomass and peat burning has a notable impact on ambient air quality and climate in the Southeast Asia (SEA) region. We modeled the largest fire-induced haze episode in the past decade (2006) in Indonesia using the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem). We focused mainly on the evolution of the fire plume composition and its interaction with the urbanized area of the city-state of Singapore, and on comparisons of modeled and measured aerosol and CO concentrations. Two simulations were run with the model using the complex Volatility Basis Set (VBS) scheme to reproduce primary and secondary aerosol evolution and concentration. The first simulation referred to as WRF-FIRE included anthropogenic, biogenic, and b iomass burning emissions from the Global Fire Emissions Database (GFED3) while the second simulation referred to as WRF-NOFIRE was run without emissions from biomass burning. To test model performance, we used three independent datasets for comparison including airborne measurements of Particulate Matter with a diameter of 10 μm or less (PM10) in Singapore, CO measurements in Sumatra, and Aerosol Optical Depth (AOD) column observations from 4 satellite-based sensors. We found reasonable agreement of the model runs with both ground-based measurements of CO and PM10. The comparison with AOD was less favorable and indicated the model underestimated AOD, although the degree of mismatch varied between different satellite data sets. During our study period, forest and peat fires in Sumatra were the main cause of enhanced aerosol concentrations from regional transport over Singapore. Analysis of the biomass burning plume showed high concentrations of primary organic aerosols (POA) with values up to 600 μg m-3 over the fire locations. The concentration of POA remained quite stable within the plume between the main burning region and Singapore while secondary organic aerosol (SOA) concentration slightly increased. The

  11. POLUTE. Forest Air Pollutant Uptake Model

    SciTech Connect

    Murphy, C.E. Jr.; Sinclair, T.R.

    1992-02-13

    POLUTE is a computer model designed to estimate the uptake of air pollutants by forests. The model utilizes submodels to describe atmospheric diffusion immediately above and within the canopy, and into the sink areas within or on the trees. The program implementing the model is general and can be used, with only minor changes, for any gaseous pollutant. The model provides an estimate describing the response of the vegetarian-atmosphere system to the environment as related to three types of processes: atmospheric diffusion, diffusion near and inside the absorbing plant, and the physical and chemical processes at the sink on or within the plant.

  12. Computational modeling of ion transport through nanopores.

    PubMed

    Modi, Niraj; Winterhalter, Mathias; Kleinekathöfer, Ulrich

    2012-10-21

    Nanoscale pores are ubiquitous in biological systems while artificial nanopores are being fabricated for an increasing number of applications. Biological pores are responsible for the transport of various ions and substrates between the different compartments of biological systems separated by membranes while artificial pores are aimed at emulating such transport properties. As an experimental method, electrophysiology has proven to be an important nano-analytical tool for the study of substrate transport through nanopores utilizing ion current measurements as a probe for the detection. Independent of the pore type, i.e., biological or synthetic, and objective of the study, i.e., to model cellular processes of ion transport or electrophysiological experiments, it has become increasingly important to understand the dynamics of ions in nanoscale confinements. To this end, numerical simulations have established themselves as an indispensable tool to decipher ion transport processes through biological as well as artificial nanopores. This article provides an overview of different theoretical and computational methods to study ion transport in general and to calculate ion conductance in particular. Potential new improvements in the existing methods and their applications are highlighted wherever applicable. Moreover, representative examples are given describing the ion transport through biological and synthetic nanopores as well as the high selectivity of ion channels. Special emphasis is placed on the usage of molecular dynamics simulations which already have demonstrated their potential to unravel ion transport properties at an atomic level.

  13. Modeling gas transport in the Martian subsurface

    NASA Astrophysics Data System (ADS)

    Gloesener, Elodie; Karatekin, Özgür; Dehant, Véronique

    2015-04-01

    Modeling gas transport through Martian subsurface and outgassing processes is essential in the study of atmospheric evolution of Mars. We present an overview of gas transport in Martian soil focusing on water vapor and methane diffusion to explain the recent observations of methane in Martian atmosphere with a diffusive transport model. The range of parameters that have the largest effect on transport in Martian conditions is investigated. Among the possible sources of methane, clathrate hydrates destabilization is one potential mechanism. Hydrate stability zone in subsurface is also investigated. In 2016, ExoMars Trace Gas Orbiter (TGO) will have the capabilities to detect and characterize trace gases in Martian atmosphere and will bring additional information to validate the different possible outgassing scenarios.

  14. Variable soft sphere molecular model for air species

    NASA Astrophysics Data System (ADS)

    Koura, Katsuhisa; Matsumoto, Hiroaki

    1992-05-01

    A reliable set of cross-section parameters of the variable soft sphere (VSS) molecular model is determined for the Monte Carlo simulation of air species from the transport collision integrals or potential parameters provided by Cubley and Mason (1975) over the high-temperature range 300-15,000 K. The VSS cross-section parameters for the inverse-power-law potential are also determined from the viscosity coefficients recommended by Maitland and Smith (1972) for common species in the low (20-300 K) and high (300-2000 K) temperature ranges.

  15. Variable soft sphere molecular model for air species

    NASA Astrophysics Data System (ADS)

    Koura, Katsuhisa; Matsumoto, Hiroaki

    1992-05-01

    A reliable set of cross-section parameters of the variable soft sphere (VSS) molecular model is determined for the Monte Carlo simulation of air species from the transport collision integrals or potential parameters provided by Cubley and Mason [Phys. Fluids 18, 1109 (1975)] over the high-temperature range 300-15 000 K. The VSS cross-section parameters for the inverse-power-law potential are also determined from the viscosity coefficients recommended by Maitland and Smith [J. Chem. Eng. Data 17, 150 (1972)] for common species in the low (20-300 K) and high (300-2000 K) temperature ranges.

  16. InMAP: a new model for air pollution interventions

    NASA Astrophysics Data System (ADS)

    Tessum, C. W.; Hill, J. D.; Marshall, J. D.

    2015-10-01

    Mechanistic air pollution models are essential tools in air quality management. Widespread use of such models is hindered, however, by the extensive expertise or computational resources needed to run most models. Here, we present InMAP (Intervention Model for Air Pollution), which offers an alternative to comprehensive air quality models for estimating the air pollution health impacts of emission reductions and other potential interventions. InMAP estimates annual-average changes in primary and secondary fine particle (PM2.5) concentrations - the air pollution outcome generally causing the largest monetized health damages - attributable to annual changes in precursor emissions. InMAP leverages pre-processed physical and chemical information from the output of a state-of-the-science chemical transport model (WRF-Chem) within an Eulerian modeling framework, to perform simulations that are several orders of magnitude less computationally intensive than comprehensive model simulations. InMAP uses a variable resolution grid that focuses on human exposures by employing higher spatial resolution in urban areas and lower spatial resolution in rural and remote locations and in the upper atmosphere; and by directly calculating steady-state, annual average concentrations. In comparisons run here, InMAP recreates WRF-Chem predictions of changes in total PM2.5 concentrations with population-weighted mean fractional error (MFE) and bias (MFB) < 10 % and population-weighted R2 ~ 0.99. Among individual PM2.5 species, the best predictive performance is for primary PM2.5 (MFE: 16 %; MFB: 13 %) and the worst predictive performance is for particulate nitrate (MFE: 119 %; MFB: 106 %). Potential uses of InMAP include studying exposure, health, and environmental justice impacts of potential shifts in emissions for annual-average PM2.5. Features planned for future model releases include a larger spatial domain, more temporal information, and the ability to predict ground-level ozone (O3

  17. Quantifying errors in trace species transport modeling

    PubMed Central

    Prather, Michael J.; Zhu, Xin; Strahan, Susan E.; Steenrod, Stephen D.; Rodriguez, Jose M.

    2008-01-01

    One expectation when computationally solving an Earth system model is that a correct answer exists, that with adequate physical approximations and numerical methods our solutions will converge to that single answer. With such hubris, we performed a controlled numerical test of the atmospheric transport of CO2 using 2 models known for accurate transport of trace species. Resulting differences were unexpectedly large, indicating that in some cases, scientific conclusions may err because of lack of knowledge of the numerical errors in tracer transport models. By doubling the resolution, thereby reducing numerical error, both models show some convergence to the same answer. Now, under realistic conditions, we identify a practical approach for finding the correct answer and thus quantifying the advection error. PMID:19066224

  18. Air pollution modeling over Europe using WRFchem

    NASA Astrophysics Data System (ADS)

    Ritter, Mathias; Müller, Mathias

    2010-05-01

    The aim of this study is to model air pollution for entire Switzerland with a very high spatial resolution. For the first time a several year period of air pollution is modeled for entire Switzerland. The high resolution domain of Switzerland is nested into a coarser European domain with a horizontal resolution of 50 km, extending from south of Spain to south of Finland. So far only the framework for the European domain exists and therefore we focus on the method and first results of this particular domain. The state-of-the-art "Weather Research and Forecasting" (WRF) model with a chemistry extension (WRFchem) is used to simulate air pollutants. It is one of the first times that these two "online" coupled models are applied for entire Europe. Gas phase chemistry is modeled with the "Carbon bond mechanism version Z" (CBMZ) with 67 prognostic chemical species and 164 chemical reactions. Aerosols are treated by the "Model for Simulating Aerosol Interactions and Chemistry" (MOSAIC) using 4 sectional aerosol bins. The meteorological initial and boundary conditions are derived from the NCEP Reanalysis 2 and GFS data. The anthropogenic emissions are taken from the European Monitoring and Evaluation Programme (EMEP), which have a horizontal resolution of 50 km and are divided into 11 SNAP-sectors (Selected Nomenclature for reporting of Air Pollutants). According to these different sectors and the countries the data could be disaggregated into hourly emissions according to the GENEMIS project. To use this dataset also a spatial conversion with the inverse next neighbor method and a vertical disaggregation as well as a re-apportioning of different chemical species were applied. Biogenic emissions are computed during runtime using the Guenther Scheme. We noticed that chemical initial conditions are not needed as they are mainly driven by emissions. Hence a spin-up of at least five days is used. For verification purposes correlations with European ground-based measurements (O3

  19. The Community Sediment Transport Modeling System

    DTIC Science & Technology

    2008-01-01

    addition to wave processes, the model includes the influence of flocculation, hindered settling, rheology, and turbulence -suppression by stratification...The extensive upwelling event occurred in March 2002 is better reproduced with evident appearance of submesoscale spiral eddies all over the inner...THE COMMUNITY SEDIMENT TRANSPORT MODELING SYSTEM W. Rockwell Geyer Woods Hole Oceanographic Institution MS 11, Woods Hole, MA 02543 phone

  20. Clinton River Sediment Transport Modeling Study

    EPA Pesticide Factsheets

    The U.S. ACE develops sediment transport models for tributaries to the Great Lakes that discharge to AOCs. The models developed help State and local agencies to evaluate better ways for soil conservation and non-point source pollution prevention.

  1. Air quality modeling in the South Coast Air Basin of California: what do the numbers really mean?

    PubMed

    Carreras-Sospedra, Marc; Dabdub, Donald; Rodríguez, Marco; Brouwer, Jacob

    2006-08-01

    This study evaluates air quality model sensitivity to input and to model components. Simulations are performed using the California Institute of Technology (CIT) airshed model. Results show the impacts on ozone (O3) concentration in the South Coast Air Basin (SCAB) of California because of changes in: (1) input data, including meteorological conditions (temperature, UV radiation, mixing height, and wind speed), boundary conditions, and initial conditions (ICs); and (2) model components, including advection solver and chemical mechanism. O3 concentrations are strongly affected by meteorological conditions and, in particular, by temperature. ICs also affect O3 concentrations, especially in the first 2 days of simulation. On the other hand, boundary conditions do not significantly affect the absolute peak O3 concentration, although they do affect concentrations near the inflow boundaries. Moreover, predicted O3 concentrations are impacted considerably by the chemical mechanism. In addition, dispersion of pollutants is affected by the advection routine used to calculate its transport. Comparison among CIT, California Photochemical Grid Model (CALGRID), and Urban Airshed Model air quality models suggests that differences in O3 predictions are mainly caused by the different chemical mechanisms used. Additionally, advection solvers contribute to the differences observed among model predictions. Uncertainty in predicted peak O3 concentration suggests that air quality evaluation should not be based solely on this single value but also on trends predicted by air quality models using a number of chemical mechanisms and with an advection solver that is mass conservative.

  2. Community Multiscale Air Quality (CMAQ) Modeling for ...

    EPA Pesticide Factsheets

    The CMAQ model is a Eulerian model that produces gridded values of atmospheric concentration and deposition. Recent updates to the model are highlighted that impact estimates of dry and wet deposition of nitrogen, sulfur and base cations. Output from the CMAQ model is used in the measurement-model fusion method used to create the National Atmospheric Program's (NADP) Total Deposition (TDEP) map product. The National Exposure Research Laboratory (NERL) Computational Exposure Division (CED) develops and evaluates data, decision-support tools, and models to be applied to media-specific or receptor-specific problem areas. CED uses modeling-based approaches to characterize exposures, evaluate fate and transport, and support environmental diagnostics/forensics with input from multiple data sources. It also develops media- and receptor-specific models, process models, and decision support tools for use both within and outside of EPA.

  3. Radionuclide Transport Models Under Ambient Conditions

    SciTech Connect

    G. Moridis; Q. Hu

    2000-03-12

    The purpose of this Analysis/Model Report (AMR) is to evaluate (by means of 2-D semianalytical and 3-D numerical models) the transport of radioactive solutes and colloids in the unsaturated zone (UZ) under ambient conditions from the potential repository horizon to the water table at Yucca Mountain (YM), Nevada. This is in accordance with the ''AMR Development Plan U0060, Radionuclide Transport Models Under Ambient Conditions'' (CRWMS M and O 1999a). This AMR supports the UZ Flow and Transport Process Model Report (PMR). This AMR documents the UZ Radionuclide Transport Model (RTM). This model considers: the transport of radionuclides through fractured tuffs; the effects of changes in the intensity and configuration of fracturing from hydrogeologic unit to unit; colloid transport; physical and retardation processes and the effects of perched water. In this AMR they document the capabilities of the UZ RTM, which can describe flow (saturated and/or unsaturated) and transport, and accounts for (a) advection, (b) molecular diffusion, (c) hydrodynamic dispersion (with full 3-D tensorial representation), (d) kinetic or equilibrium physical and/or chemical sorption (linear, Langmuir, Freundlich or combined), (e) first-order linear chemical reaction, (f) radioactive decay and tracking of daughters, (g) colloid filtration (equilibrium, kinetic or combined), and (h) colloid-assisted solute transport. Simulations of transport of radioactive solutes and colloids (incorporating the processes described above) from the repository horizon to the water table are performed to support model development and support studies for Performance Assessment (PA). The input files for these simulations include transport parameters obtained from other AMRs (i.e., CRWMS M and O 1999d, e, f, g, h; 2000a, b, c, d). When not available, the parameter values used are obtained from the literature. The results of the simulations are used to evaluate the transport of radioactive solutes and colloids, and

  4. Models for Turbulent Transport Processes.

    ERIC Educational Resources Information Center

    Hill, James C.

    1979-01-01

    Since the statistical theories of turbulence that have developed over the last twenty or thirty years are too abstract and unreliable to be of much use to chemical engineers, this paper introduces the techniques of single point models and suggests some areas of needed research. (BB)

  5. Transporting Students into Thin Air: Using Science to Enhance Reading

    ERIC Educational Resources Information Center

    Bricker, Patricia; Rogowski, Nick; Hedt, Melissa; Rolfe, Nadeen

    2010-01-01

    The "Into Thin Air" unit, based on the book by Jon Krakauer, was designed as an interdisciplinary unit for a small group of academically gifted sixth-grade students. It included hands-on, minds-on activities that would immerse students in the scientific, social, and personal struggles people face while attempting to climb the world's tallest…

  6. Investigation of air transportation technology at Ohio University, 1981. [loran

    NASA Technical Reports Server (NTRS)

    Mcfarland, R. H.

    1982-01-01

    The increased availability of Loran signals in the United States encouraged consideration of Loran for airborne applications. High quality signal processing to obtain effective signal-to-noise ratios which permit good reliability in position determination consistent with airborne applications is considered. Techniques for deriving air navigation quality information from Loran-C were investigated.

  7. Modeling Vapor and Heat Transport on Io

    NASA Astrophysics Data System (ADS)

    Allen, D. R.; Howell, R. R.

    2012-12-01

    Loki patera, a large, active volcanic depression on Jupiter's innermost Galilean moon Io, shows evidence of sulfur transport and exhibits temperatures that are consistently lower than many other volcanoes on Io. Galileo images of Loki reveal red sulfur deposits exterior to the patera that extend approximately 40 km from the patera's edge. Voyager images show light deposits, colloquially known as sulfur bergs, scattered across the patera floor that range from 3.5 km to 5 km in diameter. In addition, temperature profiles running north to south across the patera vary by only a few degrees and are difficult to explain with current thermal models, which don't include the role of volatiles such as sulfur. We are investigating the role sulfur plays in producing the features seen in images of Loki and in modifying the temperatures at Loki. We used the atmospheric models of Ingersoll (1989) and Moreno et al. (1991) for SO2 transport on Io as a starting point for our own sulfur transport models. We also compared the length scales of deposition predicted by our models and Moreno's models to the morphology and features seen in Galileo and Voyager images. In one case, Ingersoll modeled the sublimation of SO2 from a hot, higher pressure side which moves in one dimension and is deposited on a cold, lower pressure side. Using this case as a starting point, we adapted it for temperatures and pressures appropriate for S8 transport. We also converted his equations to consider the radial expansion of S8 from a point source, which we compared to the models of Moreno et al. (1991). We solved the hot side-cold side Ingersoll adapted model both analytically and numerically and obtained horizontal length scales of sulfur deposition consistent with the red deposits. We scaled the horizontal lengths of SO2 deposition predicted by Moreno's numerical models for S8 and obtained sulfur deposition lengths consistent with the light deposits. In contrast, our radial expansion model gave horizontal

  8. World Energy Projection System Plus Model Documentation: Transportation Model

    EIA Publications

    2011-01-01

    This report documents the objectives, analytical approach and development of the World Energy Projection System Plus (WEPS ) International Transportation model. It also catalogues and describes critical assumptions, computational methodology, parameter estimation techniques, and model source code.

  9. Modeling Transport of Viruses in Fractured Rock

    NASA Astrophysics Data System (ADS)

    Sleep, B. E.; Mondal, P. K.

    2011-12-01

    Fractured rock aquifers are frequently used for water supply for human consumption. In many instances the fractured rock aquifers are vulnerable to contamination by pathogens, including viruses, due to co-location of on-site septic systems, wastewater discharges, biosolids and agricultural activities. Approximately half of the illnesses associated with groundwater consumption in the Unites States have been attributed to viral contamination. A number of these cases have been related to transport of viruses from septic systems to drinking water wells. Despite the potential for rapid transport of viruses through rock fractures to drinking water wells, the understanding of virus transport in fractured rock is limited. In particular, the impacts of virus size, fracture aperture variability and roughness, matrix porosity, groundwater velocity, and geochemical conditions have not been well studied. In this study, a multidimensional model for virus transport in variable aperture fractures is presented. The model is applied to laboratory experiments on transport of virus-sized latex microspheres (0.02 and 0.2 microns) and bacteriophages (MS2 and PR772) in artificially fractured dolomite rocks. In these experiments significant impacts of particle size, fracture characteristics, groundwater velocity, and geochemistry were observed. Given the variability in aperture distribution and associated spatial variation in groundwater flow field, one-dimensional models were not suitable for a comprehensive evaluation of the mechanisms governing the microsphere and bacteriophage transport. Various relationships for virus retention (attachment and detachment) are evaluated to provide insight into the governing processes in virus transport in fractured rock. In addition, the role of virus size, fracture aperture variability, fracture roughness, fracture surface charge, matrix porosity, groundwater velocity, and ionic strength in virus transport are evaluated. Scale-up to the field is

  10. Modeling microorganism transport and survival in the subsurface.

    PubMed

    Bradford, Scott A; Wang, Yusong; Kim, Hyunjung; Torkzaban, Saeed; Šimůnek, Jiri

    2014-03-01

    An understanding of microbial transport and survival in the subsurface is needed for public health, environmental applications, and industrial processes. Much research has therefore been directed to quantify mechanisms influencing microbial fate, and the results demonstrate a complex coupling among many physical, chemical, and biological factors. Mathematical models can be used to help understand and predict the complexities of microbial transport and survival in the subsurface under given assumptions and conditions. This review highlights existing model formulations that can be used for this purpose. In particular, we discuss models based on the advection-dispersion equation, with terms for kinetic retention to solid-water and/or air-water interfaces; blocking and ripening; release that is dependent on the resident time, diffusion, and transients in solution chemistry, water velocity, and water saturation; and microbial decay (first-order and Weibull) and growth (logistic and Monod) that is dependent on temperature, nutrient concentration, and/or microbial concentration. We highlight a two-region model to account for microbe migration in the vicinity of a solid phase and use it to simulate the coupled transport and survival of species under a variety of environmentally relevant scenarios. This review identifies challenges and limitations of models to describe and predict microbial transport and survival. In particular, many model parameters have to be optimized to simulate a diversity of observed transport, retention, and survival behavior at the laboratory scale. Improved theory and models are needed to predict the fate of microorganisms in natural subsurface systems that are highly dynamic and heterogeneous.

  11. Modeling and Calculator Tools for State and Local Transportation Resources

    EPA Pesticide Factsheets

    Air quality models, calculators, guidance and strategies are offered for estimating and projecting vehicle air pollution, including ozone or smog-forming pollutants, particulate matter and other emissions that pose public health and air quality concerns.

  12. Data Assimilation in the ADAPT Photospheric Flux Transport Model

    NASA Astrophysics Data System (ADS)

    Hickmann, Kyle S.; Godinez, Humberto C.; Henney, Carl J.; Arge, C. Nick

    2015-04-01

    Global maps of the solar photospheric magnetic flux are fundamental drivers for simulations of the corona and solar wind and therefore are important predictors of geoeffective events. However, observations of the solar photosphere are only made intermittently over approximately half of the solar surface. The Air Force Data Assimilative Photospheric Flux Transport (ADAPT) model uses localized ensemble Kalman filtering techniques to adjust a set of photospheric simulations to agree with the available observations. At the same time, this information is propagated to areas of the simulation that have not been observed. ADAPT implements a local ensemble transform Kalman filter (LETKF) to accomplish data assimilation, allowing the covariance structure of the flux-transport model to influence assimilation of photosphere observations while eliminating spurious correlations between ensemble members arising from a limited ensemble size. We give a detailed account of the implementation of the LETKF into ADAPT. Advantages of the LETKF scheme over previously implemented assimilation methods are highlighted.

  13. Data Assimilation in the ADAPT Photospheric Flux Transport Model

    SciTech Connect

    Hickmann, Kyle S.; Godinez, Humberto C.; Henney, Carl J.; Arge, C. Nick

    2015-03-17

    Global maps of the solar photospheric magnetic flux are fundamental drivers for simulations of the corona and solar wind and therefore are important predictors of geoeffective events. However, observations of the solar photosphere are only made intermittently over approximately half of the solar surface. The Air Force Data Assimilative Photospheric Flux Transport (ADAPT) model uses localized ensemble Kalman filtering techniques to adjust a set of photospheric simulations to agree with the available observations. At the same time, this information is propagated to areas of the simulation that have not been observed. ADAPT implements a local ensemble transform Kalman filter (LETKF) to accomplish data assimilation, allowing the covariance structure of the flux-transport model to influence assimilation of photosphere observations while eliminating spurious correlations between ensemble members arising from a limited ensemble size. We give a detailed account of the implementation of the LETKF into ADAPT. Advantages of the LETKF scheme over previously implemented assimilation methods are highlighted.

  14. DAC 22 High Speed Civil Transport Model

    NASA Technical Reports Server (NTRS)

    1992-01-01

    Between tests, NASA research engineer Dave Hahne inspects a tenth-scale model of a supersonic transport model in the 30- by 60-Foot Tunnel at NASA Langley Research Center, Hampton, Virginia. The model is being used in support of NASA's High-Speed Research (HSR) program. Langley researchers are applying advance aerodynamic design methods to develop a wing leading-edge flap system which significantly improves low-speed fuel efficiency and reduces noise generated during takeoff operation. Langley is NASA's lead center for the agency's HSR program, aimed at developing technology to help U.S. industry compete in the rapidly expanding trans-oceanic transport market. A U.S. high-speed civil transport is expected to fly in about the year 2010. As envisioned, it would fly 300 passengers across the Pacific in about four hours at Mach 2.4 (approximately 1,600 mph/1950 kph) for a modest increase over business class fares.

  15. Band transport model for discotic liquid crystals

    NASA Astrophysics Data System (ADS)

    Lever, L. J.; Kelsall, R. W.; Bushby, R. J.

    2005-07-01

    A theoretical model is presented for charge transport in discotic liquid crystals in which a charge is delocalized over more than one lattice site. As such, charge transport is via a banded conduction process in a narrow bandwidth system and takes place over coherent lengths of a few molecules. The coherent lengths are disrupted by the geometrical disorder of the system and are treated as being terminated by quantum tunnel barriers. The transmission probabilities at these barriers have been calculated as a function of the charge carrier energy. Phononic interactions are also considered and the charge carrier scattering rates are calculated for intermolecular and intramolecular vibrations. The results of the calculations have been used to develop a Monte Carlo simulation of the charge transport model. Simulated data are presented and used to discuss the nature of the tunnel barriers required to reproduce experimental data. We find that the model successfully reproduces experimental time of flight data including temperature dependence.

  16. GEOS-5 Chemistry Transport Model User's Guide

    NASA Technical Reports Server (NTRS)

    Kouatchou, J.; Molod, A.; Nielsen, J. E.; Auer, B.; Putman, W.; Clune, T.

    2015-01-01

    The Goddard Earth Observing System version 5 (GEOS-5) General Circulation Model (GCM) makes use of the Earth System Modeling Framework (ESMF) to enable model configurations with many functions. One of the options of the GEOS-5 GCM is the GEOS-5 Chemistry Transport Model (GEOS-5 CTM), which is an offline simulation of chemistry and constituent transport driven by a specified meteorology and other model output fields. This document describes the basic components of the GEOS-5 CTM, and is a user's guide on to how to obtain and run simulations on the NCCS Discover platform. In addition, we provide information on how to change the model configuration input files to meet users' needs.

  17. Peroxy radicals and ozone photochemistry in air masses undergoing long-range transport

    NASA Astrophysics Data System (ADS)

    Parker, A. E.; Monks, P. S.; Jacob, M. J.; Penkett, S. A.; Lewis, A. C.; Stewart, D. J.; Whalley, L. K.; Methven, J.; Stohl, A.

    2009-09-01

    Concentrations of peroxy radicals (HO2+ΣiRiO2) in addition to other trace gases were measured onboard the UK Meteorological Office/Natural Environment Research Council British Aerospace 146-300 atmospheric research aircraft during the Intercontinental Transport of Ozone and Precursors (ITOP) campaign based at Horta Airport, Faial, Azores (38.58° N, 28.72° W) in July/August 2004. The overall peroxy radical altitude profile displays an increase with altitude that is likely to have been impacted by the effects of long-range transport. The peroxy radical altitude profile for air classified as of marine origin shows no discernable altitude profile. A range of air-masses were intercepted with varying source signatures, including those with aged American and Asian signatures, air-masses of biomass burning origin, and those that originated from the east coast of the United States. Enhanced peroxy radical concentrations have been observed within this range of air-masses indicating that long-range transported air-masses traversing the Atlantic show significant photochemical activity. The net ozone production at clear sky limit is in general negative, and as such the summer mid-Atlantic troposphere is at limit net ozone destructive. However, there is clear evidence of positive ozone production even at clear sky limit within air masses undergoing long-range transport, and during ITOP especially between 5 and 5.5 km, which in the main corresponds to a flight that extensively sampled air with a biomass burning signature. Ozone production was NOx limited throughout ITOP, as evidenced by a good correlation (r2=0.72) between P(O3) and NO. Strong positive net ozone production has also been seen in varying source signature air-masses undergoing long-range transport, including but not limited to low-level export events, and export from the east coast of the United States.

  18. The mistral and its effect on air pollution transport and vertical mixing

    NASA Astrophysics Data System (ADS)

    Corsmeier, U.; Behrendt, R.; Drobinski, Ph.; Kottmeier, Ch.

    2005-03-01

    Within the framework of ESCOMPTE, the influence of local wind systems like land-sea/mountain-valley winds on the distribution of air pollutants in the southern part of the Rhône valley and the coastal regions of southern France was investigated. In addition, the influence of the mistral on the long-range transport and vertical mixing of such substances on July 1, 2001 was analyzed. The results of the measurements of this mistral situation show high concentrations of O 3 and NO 2 in the layer just above the PBL at the southern exit of the Rhône valley near Avignon. By measurements from airborne and ground-based platforms and numerical simulations with the "Local Model" (LM) of the German Weather Service (DWD), it is shown that the mistral develops according to the theory conceived by Pettré [J. Atmos. Sci. 39 (1982) 542-554]. The synoptic-scale northerly flow through the Rhône valley is accelerated up to a Froude number ( Fr) of 2.1, while the valley widens. Then, near the Mediterranean coast, a hydraulic jump occurs and Fr drops down to values below 1.0. High ozone concentrations of 112 ppb measured above the mistral layer disappear due to enhanced mixing after the flow has passed the hydraulic jump. There is some evidence that the ozone-rich air originates from the source region of greater Paris or upwind. The results confirm that regional wind systems associated with transport of trace gases in the high-grade industrialized Rhône valley can be successfully predicted using data of operational weather forecast models.

  19. [Model of active peristaltic transport in biosystems].

    PubMed

    Klochkov, B N; Romanov, A S

    2013-01-01

    A nonlinear distributed mathematical model of soft vessel with the nonmonotonous static characteristic is proposed and considered. The model describes space-time dynamics of vessel clearance change. Wave phenomena in vessels of different nature and the possibility of peristaltic fluid pumping are discussed and analyzed. The model is rather common in character and represents a description of the whole class of transport phenomena. Lymphatic vessels are particularly considered.

  20. Piloted methane/air jet flames : transport effects and aspects of scalar structure.

    SciTech Connect

    Karpetis, Adionos N.; Chen, J. Y.; Barlow, Robert S.; Frank, Jonathan H.

    2005-02-01

    Previously unpublished results from multiscalar point measurements in the series of piloted CH{sub 4}/air jet flames [R.S. Barlow, J.H. Frank, Proc. Combust. Inst. 27 (1998) 1087-1095] are presented and analyzed. The emphasis is on features of the data that reveal the relative importance of molecular diffusion and turbulent transport in these flames. The complete series A-F is considered. This includes laminar, transitional, and turbulent flames spanning a range in Reynolds number from 1100 to 44,800. Results on conditional means of species mass fractions, the differential diffusion parameter, and the state of the water-gas shift reaction all show that there is an evolution in these flames from a scalar structure dominated by molecular diffusion to one dominated by turbulent transport. Long records of 6000 single-point samples at each of several selected locations in flame D are used to quantify the cross-stream (radial) dependence of conditional statistics of measured scalars. The cross-stream dependence of the conditional scalar dissipation is determined from 6000-shot, line-imaging measurements at selected locations. The cross-stream dependence of reactive scalars, which is most significant in the near field of the jet flame, is attributed to radial differences in both convective and local time scales of the flow. Results illustrate some potential limitations of common modeling assumptions when applied to laboratory-scale flames and, thus, provide a more complete context for interpretation of comparisons between experiments and model calculations.

  1. Piloted methane/air jet flames: Transport effects and aspects of scalar structure

    SciTech Connect

    Barlow, R.S.; Frank, J.H.; Karpetis, A.N.; Chen, J.-Y.

    2005-12-01

    Previously unpublished results from multiscalar point measurements in the series of piloted CH{sub 4}/air jet flames [R.S. Barlow, J.H. Frank, Proc. Combust. Inst. 27 (1998) 1087-1095] are presented and analyzed. The emphasis is on features of the data that reveal the relative importance of molecular diffusion and turbulent transport in these flames. The complete series A-F is considered. This includes laminar, transitional, and turbulent flames spanning a range in Reynolds number from 1100 to 44,800. Results on conditional means of species mass fractions, the differential diffusion parameter, and the state of the water-gas shift reaction all show that there is an evolution in these flames from a scalar structure dominated by molecular diffusion to one dominated by turbulent transport. Long records of 6000 single-point samples at each of several selected locations in flame D are used to quantify the cross-stream (radial) dependence of conditional statistics of measured scalars. The cross-stream dependence of the conditional scalar dissipation is determined from 6000-shot, line-imaging measurements at selected locations. The cross-stream dependence of reactive scalars, which is most significant in the near field of the jet flame, is attributed to radial differences in both convective and local time scales of the flow. Results illustrate some potential limitations of common modeling assumptions when applied to laboratory-scale flames and, thus, provide a more complete context for interpretation of comparisons between experiments and model calculations.

  2. CFD MODELING OF FINE SCALE FLOW AND TRANSPORT IN THE HOUSTON METROPOLITAN AREA, TEXAS

    EPA Science Inventory

    Fine scale modeling of flows and air quality in Houston, Texas is being performed; the use of computational fluid dynamics (CFD) modeling is being applied to investigate the influence of morphologic structures on the within-grid transport and dispersion of sources in grid models ...

  3. Conflict Detection and Resolution for Future Air Transportation Management

    NASA Technical Reports Server (NTRS)

    Krozel, Jimmy; Peters, Mark E.; Hunter, George

    1997-01-01

    With a Free Flight policy, the emphasis for air traffic control is shifting from active control to passive air traffic management with a policy of intervention by exception. Aircraft will be allowed to fly user preferred routes, as long as safety Alert Zones are not violated. If there is a potential conflict, two (or more) aircraft must be able to arrive at a solution for conflict resolution without controller intervention. Thus, decision aid tools are needed in Free Flight to detect and resolve conflicts, and several problems must be solved to develop such tools. In this report, we analyze and solve problems of proximity management, conflict detection, and conflict resolution under a Free Flight policy. For proximity management, we establish a system based on Delaunay Triangulations of aircraft at constant flight levels. Such a system provides a means for analyzing the neighbor relationships between aircraft and the nearby free space around air traffic which can be utilized later in conflict resolution. For conflict detection, we perform both 2-dimensional and 3-dimensional analyses based on the penetration of the Protected Airspace Zone. Both deterministic and non-deterministic analyses are performed. We investigate several types of conflict warnings including tactical warnings prior to penetrating the Protected Airspace Zone, methods based on the reachability overlap of both aircraft, and conflict probability maps to establish strategic Alert Zones around aircraft.

  4. Evaluation of Transport in the Lower Tropical Stratosphere in a Global Chemistry and Transport Model

    NASA Technical Reports Server (NTRS)

    Douglass, Anne R.; Schoeberl, Mark R.; Rood, Richard B.; Pawson, Steven; Bhartia, P. K. (Technical Monitor)

    2002-01-01

    Off-line models of the evolution of stratospheric constituents use meteorological information from a general circulation model (GCM) or from a data assimilation system (DAS). Here we focus on transport in the tropics and between the tropics and middle latitudes. Constituent fields from two simulations are compared with each other and with observations. One simulation uses winds from a GCM and the second uses winds from a DAS that has the same GCM at its core. Comparisons of results from the two simulations with observations from satellite, aircraft, and sondes are used to judge the realism of the tropical transport. Faithful comparisons between simulated fields and observations for O3, CH4, and the age-of-air are found for the simulation using the GCM fields. The same comparisons for the simulation using DAS fields show rapid upward tropical transport and excessive mixing between the tropics and middle latitudes. The unrealistic transport found in the DAS fields may be due to the failure of the GCM used in the assimilation system to represent the quasi-biennial oscillation. The assimilation system accounts for differences between the observations and the GCM by requiring implicit forcing to produce consistency between the GCM and observations. These comparisons suggest that the physical consistency of the GCM fields is more important to transport characteristics in the lower tropical stratosphere than the elimination bias with respect to meteorological observations that is accomplished by the DAS. The comparisons presented here show that GCM fields are more appropriate for long-term calculations to assess the impact of changes in stratospheric composition because the balance between photochemical and transport terms is likely to be represented correctly.

  5. Transboundary air pollution in Asia: Model development and policy implications

    NASA Astrophysics Data System (ADS)

    Holloway, Tracey

    2001-12-01

    This work investigates transboundary air pollution in Asia through atmospheric modeling and public policy analysis. As an example of models actively shaping environmental policy, the Convention on Long-Range Transboundary Air Pollution in Europe (LRTAP) is selected as a case study. The LRTAP Convention is the only mulit- lateral air pollution agreement to date, and results from the RAINS integrated assessment model were heavily used to calculate nationally differentiated emission ceilings. Atmospheric chemistry and transport are included in RAINS through the use of transfer coefficients (or ``source-receptor relationships'') relating pollutant transfer among European nations. Following past work with ATMOS to simulate sulfur species in Asia, here ATMOS is developed to include odd-nitrogen. Fitting with the linear structure of ATMOS and the emphasis on computational efficiency, a simplified chemical scheme developed for use in the NOAA Geophysical Fluid Dynamics Laboratory Global Chemical Transport Model (GFDL GCTM) is adopted. The method solves for the interconversions between NOx, HNO3, and PAN based on five reaction rates stored in look-up tables. ATMOS is used to calculate source-receptor relationships for Asia. Significant exchange of NOy occurs among China, North and South Korea, and Japan. On an annual average basis, China contributes 18% to Japan's total nitrate deposition, 46% to North Korea, and 26% to South Korea. Nitrate deposition is an important component of acidification (along with sulfate deposition), contributing 30-50% to the acid burden over most of Japan, and more than 50% to acid deposition in southeast Asia, where biomass burning emits high levels of NOx. In evaluating the policy-relevance of results from the ATMOS model, four factors are taken into account: the uncertainty and limitations of ATMOS, the environmental concerns facing Asia, the current status of the scientific community in relation to regional air pollution in the region, and

  6. Improving microbial air quality in air-conditioned mass transport buses by opening the bus exhaust ventilation fans.

    PubMed

    Luksamijarulkul, Pipat; Arunchai, Nongphon; Luksamijarulkul, Soavalug; Kaewboonchoo, Orawan

    2005-07-01

    The air quality in air-conditioned mass transport buses may affect bus drivers' health. In-bus air quality improvement with the voluntary participation of bus drivers by opening the exhaust ventilation fans in the bus was implemented in the Seventh Bus Zone of Bangkok Mass Transit Authority. Four bus numbers, including bus numbers 16, 63, 67 and 166, were randomly selected to investigate microbial air quality and to observe the effect of opening the exhaust ventilation fans in the bus. With each bus number, 9 to 10 air-conditioned buses (total, 39 air-conditioned buses) were included. In-bus air samples were collected at 5 points in each studied bus using the Millipore Air Tester. A total of 195 air samples were cultured for bacterial and fungal counts. The results reveal that the exhaust ventilation fans of 17 air-conditioned buses (43.6%) were opened to ventilate in-bus air during the cycle of the bus route. The means +/- SD of bacterial counts and fungal counts in the studied buses with opened exhaust ventilation fans (83.8 +/- 70.7 and 38.0 +/- 42.8 cfu/m3) were significantly lower than those in the studied buses without opened exhaust ventilation fans (199.6 +/- 138.8 and 294.1 +/- 178.7 cfu/m3), p < 0.0005. All the air samples collected from the studied buses with opened exhaust ventilation fans were at acceptable levels (< 500 cfu/m3) compared with 4.6% of the air samples collected from the studied buses without opened exhaust ventilation fans, which had high levels (> 500 cfu/m3). Of the studied buses with opened exhaust ventilation fans (17 buses), the bacterial and fungal counts after opening the exhaust ventilation fans (68.3 +/- 33.8 and 28.3 +/- 19.3 cfu/m3) were significantly lower than those before opening the exhaust ventilation fans (158.3 +/- 116.9 and 85.3 +/- 71.2 cfu/m3), p < 0.005.

  7. Modeling of the Nitric Oxide Transport in the Human Lungs

    PubMed Central

    Karamaoun, Cyril; Van Muylem, Alain; Haut, Benoît

    2016-01-01

    In the human lungs, nitric oxide (NO) acts as a bronchodilatator, by relaxing the bronchial smooth muscles and is closely linked to the inflammatory status of the lungs, owing to its antimicrobial activity. Furthermore, the molar fraction of NO in the exhaled air has been shown to be higher for asthmatic patients than for healthy patients. Multiple models have been developed in order to characterize the NO dynamics in the lungs, owing to their complex structure. Indeed, direct measurements in the lungs are difficult and, therefore, these models are valuable tools to interpret experimental data. In this work, a new model of the NO transport in the human lungs is proposed. It belongs to the family of the morphological models and is based on the morphometric model of Weibel (1963). When compared to models published previously, its main new features are the layered representation of the wall of the airways and the possibility to simulate the influence of bronchoconstriction (BC) and of the presence of mucus on the NO transport in lungs. The model is based on a geometrical description of the lungs, at rest and during a respiratory cycle, coupled with transport equations, written in the layers composing an airway wall and in the lumen of the airways. First, it is checked that the model is able to reproduce experimental information available in the literature. Second, the model is used to discuss some features of the NO transport in healthy and unhealthy lungs. The simulation results are analyzed, especially when BC has occurred in the lungs. For instance, it is shown that BC can have a significant influence on the NO transport in the tissues composing an airway wall. It is also shown that the relation between BC and the molar fraction of NO in the exhaled air is complex. Indeed, BC might lead to an increase or to a decrease of this molar fraction, depending on the extent of the BC and on the possible presence of mucus. This should be confirmed experimentally and might

  8. Recent Enhancements to the Community Multiscale Air Quality Model (CMAQ)

    EPA Science Inventory

    This presentation overviews recent updates to the CMAQ modeling system. The presentation will be given as part of the information exchange session on Regional Air Pollution Modeling at the UK-US Collaboration Meeting on Air Pollution Exposure Science.

  9. Mobile model and transportation planning: A brief overview

    SciTech Connect

    1996-04-01

    MOBILE is a computer model developed by the U.S. Environmental Protection Agency (EPA) for estimating emissions of air pollutants by motor vehicles. Using information on the types and ages of vehicles and on local driving conditions, MOBILE estimates emissions of various pollutants during each mile that different types of vehicles are driven. These emissions rates are combined with transportation planners` estimated of the number of miles vehicles are driven within the region to estimate area-wide total emissions of each pollutant by highway vehicles, usually during a day or year.

  10. Potential of hydrogen fuel for future air transportation systems.

    NASA Technical Reports Server (NTRS)

    Small, W. J.; Fetterman, D. E.; Bonner, T. F., Jr.

    1973-01-01

    Recent studies have shown that hydrogen fuel can yield spectacular improvements in aircraft performance in addition to its more widely discussed environmental advantages. The characteristics of subsonic, supersonic, and hypersonic transport aircraft using hydrogen fuel are discussed, and their performance and environmental impact are compared to that of similar aircraft using conventional fuel. The possibilities of developing hydrogen-fueled supersonic and hypersonic vehicles with sonic boom levels acceptable for overland flight are also explored.

  11. Climate Impact of Transportation A Model Comparison

    SciTech Connect

    Girod, Bastien; Van Vuuren, Detlef; Grahn, Maria; Kitous, Alban; Kim, Son H.; Kyle, G. Page

    2013-06-01

    Transportation contributes to a significant and rising share of global energy use and GHG emissions. Therefore modeling future travel demand, its fuel use, and resulting CO2 emission is highly relevant for climate change mitigation. In this study we compare the baseline projections for global service demand (passenger-kilometers, ton-kilometers), fuel use, and CO2 emissions of five different global transport models using harmonized input assumptions on income and population. For four models we also evaluate the impact of a carbon tax. All models project a steep increase in service demand over the century. Technology is important for limiting energy consumption and CO2 emissions, but quite radical changes in the technology mix are required to stabilize or reverse the trend. While all models project liquid fossil fuels dominating up to 2050, they differ regarding the use of alternative fuels (natural gas, hydrogen, biofuels, and electricity), because of different fuel price projections. The carbon tax of US$200/tCO2 in 2050 stabilizes or reverses global emission growth in all models. Besides common findings many differences in the model assumptions and projections indicate room for improvement in modeling and empirical description of the transport system.

  12. Fetal evaluation for transport by ultrasound performed by air medical teams: A case series.

    PubMed

    Polk, James D; Merlino, James I; Kovach, Betty L; Mancuso, Charlene; Fallon, William F

    2004-01-01

    The air medical team has limited options when evaluating the obstetrical patient and assessing fetal health during air transport to a high-risk obstetrical unit. Traditionally, physical examination and a Doppler stethoscope have been used to determine fetal heart rates and movement. However, with the advent of portable ultrasound technology, new information about the mother and child are available to the air medical crew. The Fetal Evaluation for Transport with Ultrasound (FETUS) is a screening examination that consists of an evaluation of the fetal heart rate, position, and movement and general condition of the placenta. The examination can be repeated in flight with no acoustic distortion from rotor noise. The additional information can be advantageous when transport decisions need to be made or when conditions do not allow Doppler stethoscope use.

  13. Lattice Boltzmann modeling of phonon transport

    NASA Astrophysics Data System (ADS)

    Guo, Yangyu; Wang, Moran

    2016-06-01

    A novel lattice Boltzmann scheme is proposed for phonon transport based on the phonon Boltzmann equation. Through the Chapman-Enskog expansion, the phonon lattice Boltzmann equation under the gray relaxation time approximation recovers the classical Fourier's law in the diffusive limit. The numerical parameters in the lattice Boltzmann model are therefore rigorously correlated to the bulk material properties. The new scheme does not only eliminate the fictitious phonon speed in the diagonal direction of a square lattice system in the previous lattice Boltzmann models, but also displays very robust performances in predicting both temperature and heat flux distributions consistent with analytical solutions for diverse numerical cases, including steady-state and transient, macroscale and microscale, one-dimensional and multi-dimensional phonon heat transport. This method may provide a powerful numerical tool for deep studies of nonlinear and nonlocal heat transports in nanosystems.

  14. Assessment and prediction of urban air pollution caused by motor transport exhaust gases using computer simulation methods

    NASA Astrophysics Data System (ADS)

    Boyarshinov, Michael G.; Vaismana, Yakov I.

    2016-10-01

    The following methods were used in order to identify the pollution fields of urban air caused by the motor transport exhaust gases: the mathematical model, which enables to consider the influence of the main factors that determine pollution fields formation in the complex spatial domain; the authoring software designed for computational modeling of the gas flow, generated by numerous mobile point sources; the results of computing experiments on pollutant spread analysis and evolution of their concentration fields. The computational model of exhaust gas distribution and dispersion in a spatial domain, which includes urban buildings, structures and main traffic arteries, takes into account a stochastic character of cars apparition on the borders of the examined territory and uses a Poisson process. The model also considers the traffic lights switching and permits to define the fields of velocity, pressure and temperature of the discharge gases in urban air. The verification of mathematical model and software used confirmed their satisfactory fit to the in-situ measurements data and the possibility to use the obtained computing results for assessment and prediction of urban air pollution caused by motor transport exhaust gases.

  15. Phenomenological model of nuclear primary air showers

    NASA Technical Reports Server (NTRS)

    Tompkins, D. R., Jr.; Saterlie, S. F.

    1976-01-01

    The development of proton primary air showers is described in terms of a model based on a hadron core plus an electromagnetic cascade. The muon component is neglected. The model uses three parameters: a rate at which hadron core energy is converted into electromagnetic cascade energy and a two-parameter sea-level shower-age function. By assuming an interaction length for the primary nucleus, the model is extended to nuclear primaries. Both models are applied over the energy range from 10 to the 13th power to 10 to the 21st power eV. Both models describe the size and age structure (neglecting muons) from a depth of 342 to 2052 g/sq cm.

  16. Particulate air pollution in transport micro-environments.

    PubMed

    Nasir, Zaheer Ahmad; Colbeck, Ian

    2009-06-01

    To understand the dynamics of particulate matter inside train coaches and public cars, an investigation was carried out during 2004-2006. For air-conditioned rail coaches, during peak journey times, the mean concentrations of PM10, PM2.5 and PM1 were 44 microg m(-3), 14 microg m(-3) and 12 microg m(-3), respectively. The levels fell by more than half (21 microg m(-3), 6 microg m(-3), and 4 microg m(-3)) for the same size fractions, on the same route, during the off-peak journeys. On the other hand, in non-air-conditioned coaches, the PM10 concentrations of up to 95 microg m(-3) were observed during both peak and off-peak journeys. However the concentrations of PM2.5 and PM1 were 30 microg m(-3) and 12 microg m(-3) in peak journeys in comparison to 14 microg m(-3) and 6 microg m(-3) during off-peak journeys. Over a period of four months the concentrations of PM10, PM2.5 and PM1 in car journeys were generally similar during both morning and evening journeys with average values of 21 microg m(-3) for PM10, 9 microg m(-3) for PM2.5 and 6 microg m(-3) for PM1. However during October the average concentration of PM10 was 31 microg m(-3). An analysis of nearby fixed monitoring sites for both PM10 and PM2.5 revealed an episode of high particulate pollution over southern England during one week of October. There was no statistically significant difference between particulate matter levels for morning and evening car journeys. A statistically significant correlation was found between morning and evening PM10 (0.45), PM2.5 (0.39) and PM1 (0.46). In train journeys, a statistically significant difference was observed for peak and off-peak levels of PM10, PM2.5 and PM1 in air-conditioned coaches. On the other hand, in non air-conditioned coaches a significant difference was documented only for PM2.5 and PM1.

  17. Atmospheric transport and deposition of acidic air pollutants

    SciTech Connect

    Murphy, C.E. Jr.

    1981-01-01

    Although general principles which govern atmospheric chemistry of sulfur are understood, a purely theoretical estimation of the magnitude of the processes is not likely to be useful. Furthermore, the data base necessary to make empirical estimates does not yet exist. The sulfur budget of the atmosphere appears to be dominated by man-associated sulfur. The important processes in deposition of man-associated sulfur are wet deposition of sulfate and dry deposition of SO/sub 2/. The relative importance of sulfate and SO/sub 2/ to sulfur deposition (input to watersheds) depends on the air concentrations, and either compound may be the greater contributor depending on conditions. (PSB)

  18. Linkage between an advanced air quality model and a mechanistic watershed model

    NASA Astrophysics Data System (ADS)

    Vijayaraghavan, K.; Herr, J.; Chen, S.-Y.; Knipping, E.

    2010-09-01

    An offline linkage between two advanced multi-pollutant air quality and watershed models is presented. The models linked are (1) the Advanced Modeling System for Transport, Emissions, Reactions and Deposition of Atmospheric Matter (AMSTERDAM) (a three-dimensional Eulerian plume-in-grid model derived from the Community Multiscale Air Quality (CMAQ) model) and (2) the Watershed Analysis Risk Management Framework (WARMF). The pollutants linked include gaseous and particulate nitrogen, sulfur and mercury compounds. The linkage may also be used to obtain meteorological fields such as precipitation and air temperature required by WARMF from the outputs of the meteorology chemistry interface processor (MCIP) that processes meteorology simulated by the fifth generation Mesoscale Model (MM5) or the Weather Research and Forecast (WRF) model for input to AMSTERDAM. The linkage is tested in the Catawba River basin of North and South Carolina for ammonium, nitrate and sulfate. Modeled air quality and meteorological fields transferred by the linkage can supplement the conventional measurements used to drive WARMF and may be used to help predict the impact of changes in atmospheric emissions on water quality.

  19. 77 FR 38747 - Reports by Air Carriers on Incidents Involving Animals During Air Transport

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-29

    ... all cats and dogs transported by the carrier, regardless of whether the cat or dog is transported as a... required to report all incidents involving the loss, injury, or death of cats and dogs that occur while they are traveling in an airline's care, custody, or control, regardless of whether the cat or dog...

  20. Modeling Facilitated Contaminant Transport by Mobile Bacteria

    NASA Astrophysics Data System (ADS)

    Corapcioglu, M. Yavuz; Kim, Seunghyun

    1995-01-01

    Introduction of exogenous biocolloids such as genetically engineered bacteria in a bioremediation operation can enhance the transport of contaminants in groundwater by reducing the retardation effects. Because of their colloidal size and favorable surface conditions, bacteria are efficient contaminant carriers. In cases where contaminants have a low mobility in porous media because of their high partition with solid matrix, facilitated contaminant transport by mobile bacteria can create high contaminant fluxes. When metabolically active mobile bacteria are present in a subsurface environment, the system can be treated as consisting of three phases: water phase, bacterial phase, and stationary solid matrix phase. In this work a mathematical model based on mass balance equations is developed to describe the facilitated transport and fate of a contaminant and bacteria in a porous medium. Bacterial partition between the bulk solution and the stationary solid matrix and contaminant partition among three phases are represented by expressions in terms of measurable quantities. Solutions were obtained to provide estimates of contaminant and bacterial concentrations. A dimensional analysis of the transport model was utilized to estimate model parameters from the experimental data and to assess the effect of several parameters on model behavior. The model results matched favorably with experimental data of Jenkins and Lion (1993). The presence of mobile bacteria enhances the contaminant transport. However, bacterial consumption of the contaminant, which serves as a bacterial nutrient, can attenuate the contaminant mobility. The work presented in this paper is the first three-phase model to include the effects of substrate metabolism on the fate of groundwater contaminants.

  1. Evaluating the potential influence of inter-continental transport of sulfate aerosols on air quality

    NASA Astrophysics Data System (ADS)

    Mauzerall, D. L.; Liu, J.

    2007-12-01

    In this study, we compare the potential influence of inter-continental transport of sulfate aerosols on the air quality of continental regions. We use a global chemical transport model, Model of Ozone and Related Tracers, version 2 (MOZART-2), to quantify the source-receptor relationships of inter-continental transport of sulfate aerosols among ten regions in 2000. In order to compare the importance of foreign emissions relative to domestic emissions and estimate the effect of future changes in emissions on human exposure, we define an "influence potential" (IP). The IP quantifies the human exposure that occurs in a receptor region as a result of a unit of SO2 emissions from a source region. We find that due to the non-linear nature of sulfate production, regions with low SO2 emissions usually have large domestic IP, and vice versa. An exception is East Asia (EA), which has both high SO2 emissions and relatively large domestic IP, mostly caused by the spatial coincidence of emissions and population. We find that intercontinental IPs are usually less than domestic IPs by 1-3 orders of magnitude. SO2 emissions from the Middle East (ME) and Europe (EU) have the largest potential to influence populations in surrounding regions. By comparing the IP ratios (IPR) between foreign and domestic SO2 emissions, we find that the IPR values range from 0.00001 to 0.16 and change with season. Therefore, if reducing human exposure to sulfate aerosols is the objective, all regions should first focus on reducing domestic SO2 emissions. In addition, we find that relatively high IPR values exist among the EU, ME, the former Soviet Union (FSU) and African (AF) regions. Therefore, based on the IP and IPR values, we conclude that a regional agreement among EA countries, and an inter-regional agreement among EU, ME, FSU and north AF regions to control sulfur emissions would benefit public health in these regions.

  2. Potential influence of inter-continental transport of sulfate aerosols on air quality

    NASA Astrophysics Data System (ADS)

    Liu, Junfeng; Mauzerall, Denise L.

    2007-10-01

    In this study, we compare the potential influence of inter-continental transport of sulfate aerosols on the air quality of (different) continental regions. We use a global chemical transport model, Model of Ozone and Related Tracers, version 2 (MOZART-2), to quantify the source receptor relationships of inter-continental transport of sulfate aerosols among ten regions in 2000. In order to compare the importance of foreign with domestic emissions and to estimate the effect of future changes in emissions on human exposure, we define an 'influence potential' (IP). The IP quantifies the human exposure that occurs in a receptor region as a result of a unit of SO2 emissions from a source region. We find that due to the non-linear nature of sulfate production, regions with low SO2 emissions usually have large domestic IP, and vice versa. An exception is East Asia (EA), which has both high SO2 emissions and relatively large domestic IP, mostly caused by the spatial coincidence of emissions and population. We find that inter-continental IPs are usually less than domestic IPs by 1 3 orders of magnitude. SO2 emissions from the Middle East (ME) and Europe (EU) have the largest potential to influence populations in surrounding regions. By comparing the IP ratios (IPR) between foreign and domestic SO2 emissions, we find that the IPR values range from 0.000 01 to 0.16 and change with season. Therefore, if reducing human exposure to sulfate aerosols is the objective, all regions should first focus on reducing domestic SO2 emissions. In addition, we find that relatively high IPR values exist among the EU, ME, the former Soviet Union (FSU) and African (AF) regions. Therefore, on the basis of the IP and IPR values, we conclude that a regional agreement among EA countries, and an inter-regional agreement among EU, ME, FSU and (north) AF regions to control sulfur emissions could benefit public health in these regions.

  3. A modeling framework for characterizing near-road air pollutant concentration at community scales

    EPA Science Inventory

    In this study, we combine information from transportation network, traffic emissions, and dispersion model to develop a framework to inform exposure estimates for traffic-related air pollutants (TRAPs) with a high spatial resolution. A Research LINE source dispersion model (R-LIN...

  4. Glucose Transport Machinery Reconstituted in Cell Models

    PubMed Central

    Hansen, Jesper S.; Elbing, Karin; Thompson, James R.; Malmstadt, Noah

    2015-01-01

    Here we demonstrate the production of a functioning cell model by formation of giant vesicles reconstituted with the GLUT1 glucose transporter and a glucose oxidase and hydrogen peroxidase linked fluorescent reporter internally. Hence, a simplified artificial cell is formed that is able to take up glucose and process it. PMID:25562394

  5. Glucose transport machinery reconstituted in cell models.

    PubMed

    Hansen, Jesper S; Elbing, Karin; Thompson, James R; Malmstadt, Noah; Lindkvist-Petersson, Karin

    2015-02-11

    Here we demonstrate the production of a functioning cell model by formation of giant vesicles reconstituted with the GLUT1 glucose transporter and a glucose oxidase and hydrogen peroxidase linked fluorescent reporter internally. Hence, a simplified artificial cell is formed that is able to take up glucose and process it.

  6. 77 FR 4808 - Conference on Air Quality Modeling

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-31

    ... AGENCY Conference on Air Quality Modeling AGENCY: U.S. Environmental Protection Agency (EPA). ACTION: Notice of conference. SUMMARY: The EPA will be hosting the Tenth Conference on Air Quality Modeling on... preferred air quality models and to provide a forum for public review and comment on how the...

  7. Evaluating the capability of regional-scale air quality models to capture the vertical distribution of pollutants

    EPA Science Inventory

    This study is conducted in the framework of the Air Quality Modelling Evaluation International Initiative (AQMEII) and aims at the operational evaluation of an ensemble of 12 regional-scale chemical transport models used to predict air quality over the North American (NA) and Eur...

  8. Volcanic ash forecast transport and dispersion (VAFTAD) model

    SciTech Connect

    Heffter, J.L.; Stunder, B.J.B.

    1993-12-01

    The National Oceanic and Atmospheric Administration (NOAA) Air Resources Laboratory (ARL) has developed a Volcanic Ash Forecast Transport And Dispersion (VAFTAD) model for emergency response use focusing on hazards to aircraft flight operations. The model is run on a workstation at ARL. Meteorological input for the model is automatically downloaded from the NOAA National Meteorological Center (NMC) twice-daily forecast model runs to ARL. Additional input for VAFTAD ragarding the volcanic eruption is supplied by the user guided by monitor prompts. The model calculates transport and dispersion of volcanic ash from an initial ash cloud that has reached its maximum height within 3 h of eruption time. The model assumes that spherical ash particles of diameters ranging from 0.3 to 30 micrometers are distributed throughout the initial cloud with a particle number distribution based on Mount St. Helens and Redoubt Volcano eruptions. Particles are advected horizontally and vertically by the winds and fall according to Stoke`s law with a slip correction. A bivariate-normal distribution is used for horizontally diffusing the cloud and determining ash concentrations. Model output gives maps with symbols representing relative concentrations in three flight layers, and throughout the entire ash cloud, for sequential 6- and 12-h time intervals. A verification program for VAFTAD has been started. Results subjectively comparing model ash cloud forecasts with satellite imagery for three separate 1992 eruptions of Mount Spurr in Alaska have been most encouraging.

  9. Adjoint transport calculations for sensitivity analysis of the Hiroshima air-over-ground environment

    SciTech Connect

    Broadhead, B.L.; Cacuci, D.G.; Pace, J.V. III

    1984-01-01

    A major effort within the US Dose Reassessment Program is aimed at recalculating the transport of initial nuclear radiation in an air-over-ground environment. This paper is the first report of results from adjoint calculations in the Hiroshima air-over-ground environment. The calculations use a Hiroshima/Nagasaki multi-element ground, ENDF/B-V nuclear data, one-dimensional ANISN flux weighting for neutron and gamma cross sections, a source obtained by two-dimensional hydrodynamic and three-dimensional transport calculations, and best-estimate atmospheric conditions from Japanese sources. 7 references, 2 figures.

  10. Air Pollution Data for Model Evaluation and Application

    EPA Science Inventory

    One objective of designing an air pollution monitoring network is to obtain data for evaluating air quality models that are used in the air quality management process and scientific discovery.1.2 A common use is to relate emissions to air quality, including assessing ...

  11. QUANTIFYING SUBGRID POLLUTANT VARIABILITY IN EULERIAN AIR QUALITY MODELS

    EPA Science Inventory

    In order to properly assess human risk due to exposure to hazardous air pollutants or air toxics, detailed information is needed on the location and magnitude of ambient air toxic concentrations. Regional scale Eulerian air quality models are typically limited to relatively coar...

  12. Modeling Air Pollution in Beijing: Emission Reduction vs. Meteorological Influence

    NASA Astrophysics Data System (ADS)

    Risse, Eicke-Alexander; Hao, Nan; Trautmann, Thomas

    2016-08-01

    This case study uses the Chemical Transport Model WRF-Chem to simulate and measure the efficiency of temporal large-scale emission reductions under different meteorological conditions. The Nov. 2014 Asian Pacific Economic Cooperation (APEC) summit provides a unique opportunity for this study due to the extraordinarily good and well-measured air quality which is believed to be induced by intense emission- reduction measures by the Chinese government. Four cases are simulated to inter-compare between favorable und unfavorablemeteorological conditions (in terms of air quality) as well as reduced and non-reduced emissions. Key variables of the simulation results are evaluated against AERONET measurements of Aerosol Optical Depth (AOD) and air-quality measurements by the Chinese Ministry of Environment (CME). The inter-comparison is then performed on time- and volume-averaged total concentrations of the key variables Nitrogenous Oxide (NOx) and Particulate Matter (PM2.5 and PM10).The simulation settings and some important facts about the model are shown in table 1.

  13. Nanoscale air bearing modeling via lattice Boltzmann method

    NASA Astrophysics Data System (ADS)

    Kim, Woo Tae; Jhon, Myung S.; Zhou, Yong; Staroselsky, Ilya; Chen, Hudong

    2005-05-01

    As spacing between the two solid surfaces in operating condition becomes much smaller than the mean free path of the air, continuum-based Navier-Stokes equation is no longer valid and one has to use a modified Reynolds equation (MRE) in simulating high Knudsen number air bearing. This MRE, which stems from the linearized Boltzmann transport equation with Bhatnagar-Gross-Krook approximation via the appropriate choice of the boundary condition, has the advantages of calculating the pressure distribution in a nanoscale confined gaseous system. In this paper, we provide a methodology based on the lattice Boltzmann method (LBM), which could enhance the computational capability of nanoscale confined gaseous system by calculating both velocity and pressure fields simultaneously. The advantage of transient and parallel nature makes this LBM an attractive tool for the next generation air bearing design. Furthermore, LBM is suitable for hybridization with lubricant morphology as well as multiscale modeling including entire disk flow analysis. We demonstrate the feasibility of this LBM by using first-order slip model as a case study. Hybridization with database established by Kang et al. [S.-C. Kang, R. M. Crone, and M. S. Jhon, J. Appl. Phys. 85, 5594 (1999)] can be performed via the similar procedure reported here to develop the state-of-the-art slider design software.

  14. Transport of desert dust mixed with North African industrial pollutants in the subtropical Saharan Air Layer

    NASA Astrophysics Data System (ADS)

    Rodríguez, S.; Alastuey, A.; Alonso-Pérez, S.; Querol, X.; Cuevas, E.; Abreu-Afonso, J.; Viana, M.; Pérez, N.; Pandolfi, M.; de La Rosa, J.

    2011-07-01

    An analysis of chemical composition data of particulate matter samples (TSP, PM10 and PM2.5) collected from 2002 to 2008 in the North Atlantic free troposphere at the Izaña Global Atmospheric Watch (GAW) observatory (Tenerife, Canary Islands) shows that desert dust is very frequently mixed with particulate pollutants in the Saharan Air Layer (SAL). The study of this data set with Median Concentrations At Receptor (MCAR) plots allowed the identification of the potential source regions of the dust and particulate pollutants. Areas located at the south of the southern slope of the Atlas mountains emerge as the most frequent source of the soil desert dust advected to the northern edge of the SAL in summer. Industrial emissions occurring in Northern Algeria, Eastern Algeria, Tunisia and the Atlantic coast of Morocco appear as the most important source of the nitrate, ammonium and a fraction of sulphate (at least 60 % of the sulphate <10 μm transported from some regions) observed in the SAL. These emissions are mostly linked to crude oil refineries, phosphate-based fertilizer industry and power plants. Although desert dust emissions appear as the most frequent source of the phosphorous observed in the SAL, high P concentrations are observed when the SAL is affected by emissions from open mines of phosphate and phosphate based fertilizer industry. The results also show that a significant fraction of the sulphate (up to 90 % of sulphate <10 μm transported from some regions) observed in the SAL may be influenced by soil emissions of evaporite minerals in well defined regions where dry saline lakes (chotts) are present. These interpretations of the MCAR plots are consistent with the results obtained with the Positive Matrix Factorization (PMF2) receptor modelling. The results of this study show that North African industrial pollutants may be mixed with desert dust and exported to the North Atlantic in the Saharan Air Layer.

  15. Transport of desert dust mixed with North African industrial pollutants in the subtropical Saharan Air Layer

    NASA Astrophysics Data System (ADS)

    Rodríguez, S.; Alastuey, A.; Alonso-Pérez, S.; Querol, X.; Cuevas, E.; Abreu-Afonso, J.; Viana, M.; Pandolfi, M.; de La Rosa, J.

    2011-03-01

    The chemical composition of particulate matter samples (TSP, PM10 and PM2.5) collected from 2002 to 2008 in the North Atlantic free troposphere at Izaña Global Atmospheric Watch (GAW) observatory (Tenerife, The Canary Islands) was studied. The analysis of the samples collected in the Saharan Air Layer (SAL) shows that soil desert dust is very frequently mixed with particulate pollutants. An analysis of this data set with Median Concentrations At Receptor (MCAR) plots allowed to identify the potential source regions of the dust and particulate pollutants. Areas located at the south of the Southern slope of Atlas emerge as the most frequent source of the soil desert dust advected to the northern edge of the SAL in summer. Industrial emissions occurring along the Atlantic coast of Morocco, Northern Algeria, Eastern Algeria and Tunisia appear as the most important source of the nitrate, ammonium and a fraction of sulphate (at least a 60% of the sulphate <10 μm transported from some regions) observed in the SAL. These emissions are mostly linked to crude oil refineries, phosphate-based fertilizer industry and power plants. Although desert dust emissions appear as the most frequent source of the phosphorous observed in the SAL, high P concentrations are observed when the SAL is affected by emissions from open mines of phosphate and phosphate based fertilizer industry. The results also show that a significant fraction of the sulphate (up to 90% of sulphate <10 μm transported from some regions) observed in the SAL is linked to soil emissions of evaporite minerals in well defined regions where dry saline lakes (chotts) are present. These interpretations of the MCAR plots are consistent with the results obtained with the Positive Matrix Factorization receptor modelling. The results of this study show that North African industrial pollutants may be mixed with desert dust and exported to the North Atlantic in the Saharan Air Layer.

  16. Modeling field scale unsaturated flow and transport processes

    SciTech Connect

    Gelhar, L.W.; Celia, M.A.; McLaughlin, D.

    1994-08-01

    The scales of concern in subsurface transport of contaminants from low-level radioactive waste disposal facilities are in the range of 1 to 1,000 m. Natural geologic materials generally show very substantial spatial variability in hydraulic properties over this range of scales. Such heterogeneity can significantly influence the migration of contaminants. It is also envisioned that complex earth structures will be constructed to isolate the waste and minimize infiltration of water into the facility. The flow of water and gases through such facilities must also be a concern. A stochastic theory describing unsaturated flow and contamination transport in naturally heterogeneous soils has been enhanced by adopting a more realistic characterization of soil variability. The enhanced theory is used to predict field-scale effective properties and variances of tension and moisture content. Applications illustrate the important effects of small-scale heterogeneity on large-scale anisotropy and hysteresis and demonstrate the feasibility of simulating two-dimensional flow systems at time and space scales of interest in radioactive waste disposal investigations. Numerical algorithms for predicting field scale unsaturated flow and contaminant transport have been improved by requiring them to respect fundamental physical principles such as mass conservation. These algorithms are able to provide realistic simulations of systems with very dry initial conditions and high degrees of heterogeneity. Numerical simulation of the movement of water and air in unsaturated soils has demonstrated the importance of air pathways for contaminant transport. The stochastic flow and transport theory has been used to develop a systematic approach to performance assessment and site characterization. Hypothesis-testing techniques have been used to determine whether model predictions are consistent with observed data.

  17. Assessment of air quality in a commercial cattle transport vehicle in Swedish summer and winter conditions.

    PubMed

    Wikner, I; Gebresenbet, G; Nilsson, C

    2003-03-01

    Transport by road can induce significant stress in cattle. Thermal stress is among the main stress producing factors during transport. The provision of ventilation in livestock transport vehicles is usually through openings along the sides of the vehicle. The incoming air will affect air quality inside by regulating temperature, relative humidity, gas levels and levels of other contaminants. The aim of the present investigation was to map out the air quality in a commercial cattle transport vehicle under various climatic conditions and with varying stocking densities and transport times. Distributions of air temperature, relative humidity and concentrations of ammonia, carbon dioxide, oxygen and methane have been determined during 35 experimental journeys. In average the mean temperature inside the compartment was about 3 degrees C and 6 degrees C higher than outside temperature in summer (+7.8(-)+24.0 degrees C) and winter (-24.3(-)+12.7 degrees C) conditions respectively. The temperature increment inside, as could be expected from theory, increased with reduced ventilation and increased animal density. Many stops to load new animals lowered the temperature increment and relative humidity in winter time. In summer more stops made the compartment temperature and relative humidity increase. The inside temperature distribution was less than about 3 degrees C during both summer and winter season. Average ammonia level varied between 3 and 6 ppm depending on stocking density and number of stops with a maximum value of 18 ppm. No detectable methane levels could be found inside the compartment at any time.

  18. Stochastic models for convective momentum transport.

    PubMed

    Majda, Andrew J; Stechmann, Samuel N

    2008-11-18

    The improved parameterization of unresolved features of tropical convection is a central challenge in current computer models for long-range ensemble forecasting of weather and short-term climate change. Observations, theory, and detailed smaller-scale numerical simulations suggest that convective momentum transport (CMT) from the unresolved scales to the resolved scales is one of the major deficiencies in contemporary computer models. Here, a combination of mathematical and physical reasoning is utilized to build simple stochastic models that capture the significant intermittent upscale transports of CMT on the large scales due to organized unresolved convection from squall lines. Properties of the stochastic model for CMT are developed below in a test column model environment for the large-scale variables. The effects of CMT from the stochastic model on a large-scale convectively coupled wave in an idealized setting are presented below as a nontrivial test problem. Here, the upscale transports from stochastic effects are significant and even generate a large-scale mean flow which can interact with the convectively coupled wave.

  19. The Bunny: A simulated commercial air transportation study

    NASA Technical Reports Server (NTRS)

    Fulton, David; Gallagher, Patrick; Grannan, William; Martin, Jennifer; Mastej, Nicole; Wujek, Brett

    1993-01-01

    The Bunny is a single-engine, 100 passenger commercial transport designed to serve the high density short-to-medium range markets in AEROWORLD. The aircraft's design range is 10,000 feet at a cruise velocity of 30 ft/s. The aircraft features a low wing which incorporates polyhedral for roll control. Yaw and pitch control are accomplished by a rudder and elevator, respectively. Propulsion is provided by a nose-mounted Astro 15 electric motor powered by thirteen 1.2 V, 1000 mah batteries with a Zinger 12-6 propeller. The aircraft is structurally designed with a safety factor of 1.5 and is constructed primarily of balsa, bass, and birch wood. Passenger seating is arranged on two levels, with three-abreast on the lower level and two-abreast on the upper level. The factors which had the most significant influence on the final design were the direct operating cost and the take-off distance. The primary strength of The Bunny is its ability to compete economically with the HB-40. At full capacity and mid-range fuel costs, the cost per seat per thousand feet (CPSK) of this aircraft is 25% less than the HB-40. Another principal strength is its ability to operate in all airports in AEROWORLD. Also, The Bunny's two-piece removable wing is an advantage from a transportability standpoint.

  20. Modeling electronic quantum transport with machine learning

    NASA Astrophysics Data System (ADS)

    Lopez-Bezanilla, Alejandro; von Lilienfeld, O. Anatole

    2014-06-01

    We present a machine learning approach to solve electronic quantum transport equations of one-dimensional nanostructures. The transmission coefficients of disordered systems were computed to provide training and test data sets to the machine. The system's representation encodes energetic as well as geometrical information to characterize similarities between disordered configurations, while the Euclidean norm is used as a measure of similarity. Errors for out-of-sample predictions systematically decrease with training set size, enabling the accurate and fast prediction of new transmission coefficients. The remarkable performance of our model to capture the complexity of interference phenomena lends further support to its viability in dealing with transport problems of undulatory nature.