Composite carbon fluid separation membranes

The invention provides carbon membranes for use in fluid separation processes, particularly gas separations, which are treated with a coating that provides a protective barrier which significantly limits permeation of water vapor or other impurities such as hydrocarbons without significantly inhibiting permeation of the faster fluid component or lowering selectivity. The composite membranes retain good fluid separation properties and are resistant to the adverse effects on membrane performance commonly observed in environments having high humidity. The coating is preferably an amorphous polymer of perfluoro-2,2-dimethyl-1,3-dioxole. The membranes can be of a varied configuration: sheet form, hollow fiber, asymmetrical membranes and the like.Board of Regents, University of Texas Syste

Processes to condition gas permeable membranes

Glassy-type gas separating membranes are conditioned to a state of enhanced permeability through controlled sorption of a selected conditioning gas such as CO.sub.2. Membranes are swelled to a state of plasticity without being rubberized and maintained in this state to allow their permeabilities to settle to a new, higher steady-state value. Upon depressurization, conditioned membranes exhibit enhanced permeability over untreated membranes, without serious loss of permselectivity. Membranes so conditioned must be maintained with a minimum sorption level of a conditioning or maintaining gas pending use to retain their improved characteristics.Board of Regents, University of Texas Syste

Gas separations using mixed matrix membranes

Mixed matrix membranes capable of separating carbon dioxide from mixtures including carbon dioxide and methane, and processes for purifying methane using the membranes, are disclosed. The membranes are polymer membranes with a selective layer thickness of between about 1000 Angstroms to about 0.005 inch, that include discrete carbon-based molecular sieve particles with sizes of between about 0.5 microns to about 5.0 microns. The preferred ratio of particles to polymer is about 20% to about 50% by volume. A preferred method for preparing the mixed matrix membrane is by dispersing the particles in a solvent, adding a small quantity of the desired polymer or “sizing agent” to “size” or “prime” the particles, adding a polymer, casting a film of the polymer solution, and evaporating the solvent to form a mixed matrix membrane film. The mixed matrix membrane film permits passage of carbon dioxide and methane, but at different permeation rates, such that the ratio of the relative permeation rates of carbon dioxide to methane is larger through the mixed matrix membrane film than through the original polymer. The polymer is preferably a rigid, glassy polymer, more preferably, with a glass transition temperature above about 150° C. The mixed matrix membrane is preferably in the form of a dense film or a hollow fiber. A mixture containing carbon dioxide and methane can be enriched in methane by selective passage of carbon dioxide over methane in a gas-phase process through the membrane.Board of Regents, University of Texas Syste

Diffusion of light gases in 6FDA/BPDA-DAM Carbon Molecular Sieve membranes by Pulsed Field Gradient NMR

In this paper, we demonstrate the potential of pulsed field gradient (PFG) NMR spectroscopy to reveal detailed knowledge of self-diffusion of light gases and light gas mixtures in carbon molecular sieve membranes on small length scales. PFG NMR is used to investigate intra-membrane diffusion of carbon dioxide and methane for a broad range of temperatures and mean square displacements in a carbon molecular sieve membrane derived from a 6FDA/BPDA-DAM polyimide film. Diffusion is investigated with single component sorbates as well as with a carbon dioxide / methane mixture. Results obtained from these studies are compared and discussed

Advanced Concept of the National Airspace System of 2015: Human Factors Considerations for Air Traffic Control

During the next decade, all users and service providers within the National Airspace System (NAS) will experience profound changes. This report focuses on changes to the roles, responsibilities, and procedures for air traffic controllers during the transition and implementation of the new NAS. This report provides a description of upcoming enhancements for each system, human factors implications of these enhancements, and the effect of these new technologies and processes on air traffic controllers. The authors suggest that technology alone will not be able to support the increased capacity demands and that system designers will need to rely on a combination of technology and consideration of the human operators in the system. They conclude that the primary human factors considerations of these new technologies and procedures are in the areas of information processing, situation awareness, workload, errors, skill acquisition and maintenance, and new roles and responsibilities

En Route Information Display System Benefits Study

The Federal Aviation Administration (FAA) is deploying the En Route Information Display System (ERIDS) as an interactive electronic information display system to replace the current Air Traffic Control (ATC) information display system that consists mostly of paper materials. The purpose of this study is to research the benefits of ERIDS to controllers in terms of service efficiency and to the FAA in terms of potential cost savings of personnel labor. We visited the Jacksonville Air Route Traffic Control Center (ARTCC) where ERIDS is deployed and the Houston ARTCC where controllers are using paper reference manuals. We observed controllers during live operations, conducted a simulation to collect access times to ATC information, administered a questionnaire, obtained quarterly reports of ERIDS usage, and interviewed staff personnel who support both systems. Thirty-seven supervisors and traffic management coordinators participated in the simulation and provided questionnaire responses. In simulation, participants were generally not faster to access information using ERIDS compared to paper reference manuals. However, our simulation was limited in that all paper reference manuals were within reach of participants. In actual operations, ERIDS can be quickly accessed, whereas, it can take several minutes to find paper reference manuals. Interviews indicated that ERIDS can reduce the labor spent on disseminating paper reference materials

Recommended Layouts for the En Route Area Supervisor Work Space

Over the past decade, the Supervisor Work Space (SWS) at Air Route Traffic Control Centers (ARTCCs) has evolved to include as many as eight computer-based systems and other legacy equipment, paper reference materials, and supplies. Researchers from the Federal Aviation Administration Human Factors (HF) Team surveyed supervisors regarding equipment usage, location, and placement issues. Supervisors from 20 ARTCCs responded. The supervisors reported using computer systems approximately 50% of the time during a typical shift. They noted that their work spaces were cluttered, that placement of some systems made it difficult to see monitors or to access input devices, and that it was difficult to maintain the equipment. The HF researchers identified two common SWS layouts: (a) one layout in which the supervisor was seated in the main aisle looking into the operations area and (b) an alternate layout in which the supervisor was seated inside the operations area. The researchers developed baseline virtual reality models of the SWS based on HF guidelines and satisfactory aspects of existing work spaces. A working group of operational supervisors reviewed the baseline models and developed recommended layouts for the exterior, interior, and centralized command models of the en route area SWS

A Human Factors Simulation of Required Navigation Performance Converging Approach Procedure

The National Airspace System Human Factors Research and Engineering Group (HFREG) Federal Aviation Administration NAS Human Factors Group William J. Hughes Technical Center Atlantic City International Airport, NJ 08405, assessed a proposed Required Navigation Performance (RNP) procedure into San Francisco International Airport (SFO).RNP technology offers several operational benefits including more efficient utilization of airspace, reduced flying time, and reduced air-to-ground communications. The simulation focused on human factors issues affecting Air Traffic Control Specialists (ATCSs)when operating a converging runway approach procedure into the SFO Runway 28R during reduced visibility conditions. Sixteen ATCSs participated in the simulation that we conducted at the Northern California Terminal Radar Approach Control in December2004. The simulation assessed the controllers\u2019 ability to identify blundering aircraft using an Airport Surveillance Radar-9 (ASR-9)display. It also evaluated the propensity for nuisance breakouts, communications options, No Transgression Zone placement options, and the impact of high traffic levels. The simulation comprised a reaction time task and a series of high fidelity operational scenarios designed to assess the viability of the proposed approach. The study confirmed that monitor controllers identified blundering aircraft accurately and timely when using the ASR-9 display. Sector performance remained high across all conditions, and controllers demonstrated no serious operational deficiencies. Overall, the controllers provided positive ratings and comments regarding the proposed 28R RNP approach and procedure. The simulation resulted in two primary recommendations (a) incorporate Air Traffic procedures for RNP approaches into Federal Aviation Administration Order 7110.65 to ensure that ATCSs receive RNP-specific training and (b) present Flight Management System/RNP equipment information in the data block

Workstation and Workplace Ergonomics at Federal Aviation Administration Operations Control Centers: Phase 1- Evaluation of Ergonomic Issues

The purpose of this study was to collect data on current workplace ergonomic conditions at Federal Aviation Administration Operations Control Centers. Ergonomic issues and associated work-related musculoskeletal disorders can arise due to a combination of factors including environmental conditions, workstation design, frequency and duration of tasks, and psychosocial considerations. In order to create a comprehensive picture of Operational Control Center ergonomics, researchers collected a range of data. Researchers collected data on the workplace environment, including temperature, lighting, and noise. They collected workstation data, measuring the dimensions and features of the desks and chairs and comparing them to standards. Researchers observed and recorded the frequency and duration of user activities during periods of typical work. Finally, they collected data through a questionnaire, which allowed the participants to provide feedback and ratings on their current level of discomfort and on various aspects of their work environment. The research team identified instances where measurements of the current workplace did not meet recommended standards, including temperature, lighting, and workstation adjustability. These deficiencies could result in increased ergonomic risk to the users, a concern that was reflected in the questionnaire results. Questionnaire responses also identified potential ergonomic issues beyond the physical workstation, including psychosocial and organizational factors. These issues and some potential solutions are discussed in detail in this report

Human Factors Assessment of the En Route Information Display System

Human factors researchers at the Federal Aviation Administration have developed new methods of operation for Air Traffic Control Specialists working in Airport Traffic Control Towers (ATCT). The newly redesigned and enhanced Tower Operations Digital Data System (TODDS) provides a means to assist ATCT controllers with flight data management, communication, and coordination by reducing cognitive and physical task load. The TODDS prototype designs include separate solutions for ATCTs either with or without surface surveillance capability. This report addresses the results of a recent usability test by providing a description of design changes and new features that compose the TODDS. The author also recommends the use of a touchscreen training protocol. Pending further investigation, the TODDS may help reduce the risk of runway incursions, ease the flow of surface operations, and support the Staffed Virtual Tower concept