47 CFR 87.351 - Frequency changes.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Frequency changes. 87.351 Section 87.351... Aeronautical Utility Mobile Stations § 87.351 Frequency changes. When the aeronautical utility frequency is required to be changed because of an action by the FAA or the Commission (such as a change in the ground...

Hydrogeology from 10,000 ft below: lessons learned in applying pulse testing for leakage detection in a carbon sequestration formation

NASA Astrophysics Data System (ADS)

Sun, A. Y.; Lu, J.; Hovorka, S. D.; Freifeld, B. M.; Islam, A.

2015-12-01

Monitoring techniques capable of deep subsurface detection are desirable for early warning and leakage pathway identification in geologic carbon storage formations. This work investigates the feasibility of a leakage detection technique based on pulse testing, which is a traditional hydrogeological characterization tool. In pulse testing, the monitoring reservoir is stimulated at a fixed frequency and the acquired pressure perturbation signals are analyzed in the frequency domain to detect potential deviations in the reservoir's frequency domain response function. Unlike traditional time-domain analyses, the frequency-domain analysis aims to minimize the interference of reservoir noise by imposing coded injection patterns such that the reservoir responses to injection can be uniquely determined. We have established the theoretical basis of the approach in previous work. Recently, field validation of this pressure-based, leakage detection technique was conducted at a CO2-EOR site located in Mississippi, USA. During the demonstration, two sets of experiments were performed using 90-min and 150-min pulsing periods, for both with and without leak scenarios. Because of the lack of pre-existing leakage pathways, artificial leakage CO2 was simulated by rate-controlled venting from one of the monitoring wells. Our results show that leakage events caused a significant deviation in the amplitude of the frequency response function, indicating that pulse testing may be used as a cost-effective monitoring technique with a strong potential for automation.

Extensive paternal mtDNA leakage in natural populations of Drosophila melanogaster.

PubMed

Nunes, Maria D S; Dolezal, Marlies; Schlötterer, Christian

2013-04-01

Strict maternal inheritance is considered a hallmark of animal mtDNA. Although recent reports suggest that paternal leakage occurs in a broad range of species, it is still considered an exceptionally rare event. To evaluate the impact of paternal leakage on the evolution of mtDNA, it is essential to reliably estimate the frequency of paternal leakage in natural populations. Using allele-specific real-time quantitative PCR (RT-qPCR), we show that heteroplasmy is common in natural populations with at least 14% of the individuals carrying multiple mitochondrial haplotypes. However, the average frequency of the minor mtDNA haplotype is low (0.8%), which suggests that this pervasive heteroplasmy has not been noticed before due to a lack of power in sequencing surveys. Based on the distribution of mtDNA haplotypes in the offspring of heteroplasmic mothers, we found no evidence for strong selection against one of the haplotypes. We estimated that the rate of paternal leakage is 6% and that at least 100 generations are required for complete sorting of mtDNA haplotypes. Despite the high proportion of heteroplasmic individuals in natural populations, we found no evidence for recombination between mtDNA molecules, suggesting that either recombination is rare or recombinant haplotypes are counter-selected. Our results indicate that evolutionary studies using mtDNA as a marker might be biased by paternal leakage in this species. © 2013 Blackwell Publishing Ltd.

Western Aeronautical Test Range

NASA Technical Reports Server (NTRS)

Sakahara, Robert D.

2008-01-01

This viewgraph presentation reviews the work of the Western Aeronautical Test Range (WATR). NASA's Western Aeronautical Test Range is a network of facilities used to support aeronautical research, science missions, exploration system concepts, and space operations. The WATR resides at NASA's Dryden Flight Research Center located at Edwards Air Force Base, California. The WATR is a part of NASA's Corporate Management of Aeronautical Facilities and funded by the Strategic Capability Asset Program (SCAP). Maps show the general location of the WATR area that is used for aeronautical testing and evaluation. The products, services and facilities of WATR are discussed,

Experimental Investigation of Elastomer Docking Seal Compression Set, Adhesion, and Leakage

NASA Technical Reports Server (NTRS)

Daniels, Christopher C.; Oswald, Jay J.; Bastrzyk, Marta B.; Smith, Ian; Dunlap, Patrick H., Jr.; Steinetz, Bruce M.

2008-01-01

A universal docking and berthing system is being developed by the National Aeronautics and Space Administration (NASA) to support all future space exploration missions to low-Earth orbit (LEO), to the Moon, and to Mars. An investigation of the compression set of two seals mated in a seal-on-seal configuration and the force required to separate the two seals after periods of mating was conducted. The leakage rates of seals made from two silicone elastomer compounds, S0383-70 and S0899-50, configured in seal-on-seal mating were quantified. The test specimens were sub-scale seals with representative cross-sections and a 12 inch outside diameter. The leakage rate of the seals manufactured from S0899-50 was higher than that of the seals made from S0383-70 by a factor of 1.8. Similarly, the adhesion of the 50 durometer elastomer was significantly higher than that of the 70 durometer compound. However, the compression set values of the S0899-50 material were observed to be significantly lower than those for the S0383-70.

Nomenclature for Aeronautics

NASA Technical Reports Server (NTRS)

1924-01-01

This nomenclature for aeronautics was prepared by a special conference on aeronautical nomenclature by the Executive Committee of the National Advisory Committee for Aeronautics at a meeting held August 11, 1933. This publication supersedes all previous publications of the committee on this subject. The purpose of the committee in the preparation and publication of this report is to secure uniformity in the official documents of the government and, as far as possible, in technical and other commercial publications.

Nomenclature for Aeronautics

NASA Technical Reports Server (NTRS)

1923-01-01

This nomenclature for aeronautics was prepared by a special conference on aeronautical nomenclature, composed of representatives of the Army and Navy Air Services, the Air Mail Service, the Bureau of Standards, the National Advisory Committee for Aeronautics, and private life. This report supersedes all previous publications of the committee on this subject. It is published with the intention of securing greater uniformity and accuracy in official documents of the government, and, as far as possible, in technical and other commercial publications. (author)

NASA/University Conference on Aeronautics

NASA Technical Reports Server (NTRS)

1975-01-01

The proceedings of a conference on the future of aeronautics are presented. The subjects discussed include the following: (1) aeronautics and the education of the engineer, (2) technical trends in aeronautics, and (3) the role of the university in aeronautics. The technical trends in aeronautics are concerned with aircraft noise control, the effect of the aircraft on the environment, airborne electronics for automated flight, and trends in aircraft design.

Nomenclature for Aeronautics

NASA Technical Reports Server (NTRS)

1939-01-01

The nomenclature for aeronautics presented in this Report No. 474 is a revision of the last previous report on this subject (i.e., Report no. 240.) This report is published for the purpose of encouraging greater uniformity and precision in the use of terms relating to aeronautics, both in official documents of the Government and in commercial publications. Terms in general use in other branches of engineering have been included only where they have some special significance in aeronautics, or form an integral part of its terminology.

Power Beaming Leakage Radiation as A SETI Observable

NASA Technical Reports Server (NTRS)

Benford, James N.; Benford, Dominic J.

2016-01-01

The most observable leakage radiation from an advanced civilization may well be from the use of power beam-ing to transfer energy and accelerate spacecraft. Applications suggested for power beaming involve launching spacecraft to orbit, raising satellites to a higher orbit, and interplanetary concepts involving space-to-space transfers of cargo or passengers. We also quantify beam-driven launch to the outer solar system, interstellar precursors and ultimately starships. We estimate the principal observable parameters of power beaming leak-age. Extraterrestrial civilizations would know their power beams could be observed, and so could put a message on the power beam and broadcast it for our receipt at little additional energy or cost. By observing leakage from power beams we may find a message embedded on the beam. Recent observations of the anomalous star KIC8462852 by the Allen Telescope Array (ATA) set some limits on extraterrestrial power beaming in that system.We show that most power beaming applications commensurate with those suggested for our solar system would be detectable if using the frequency range monitored by the ATA, and so the lack of detection is a meaningful,if modest, constraint on extraterrestrial power beaming in that system. Until more extensive observations are made, the limited observation time and frequency coverage are not sufficiently broad in frequency and duration to produce firm conclusions. Such beams would be visible over large interstellar distances. This implies a new approach to the SETI search: Instead of focusing on narrowband beacon transmissions generated by another civilization, look for more powerful beams with much wider bandwidth. This requires a new approach for their discovery by telescopes on Earth. Further studies of power beaming applications should be done, which could broaden the parameter space of observable features we have discussed here.

Power Beaming Leakage Radiation as a SETI Observable

NASA Astrophysics Data System (ADS)

Benford, James N.; Benford, Dominic J.

2016-07-01

The most observable leakage radiation from an advanced civilization may well be from the use of power beaming to transfer energy and accelerate spacecraft. Applications suggested for power beaming involve launching spacecraft to orbit, raising satellites to a higher orbit, and interplanetary concepts involving space-to-space transfers of cargo or passengers. We also quantify beam-driven launch to the outer solar system, interstellar precursors, and ultimately starships. We estimate the principal observable parameters of power beaming leakage. Extraterrestrial civilizations would know their power beams could be observed, and so could put a message on the power beam and broadcast it for our receipt at little additional energy or cost. By observing leakage from power beams we may find a message embedded on the beam. Recent observations of the anomalous star KIC 8462852 by the Allen Telescope Array (ATA) set some limits on extraterrestrial power beaming in that system. We show that most power beaming applications commensurate with those suggested for our solar system would be detectable if using the frequency range monitored by the ATA, and so the lack of detection is a meaningful, if modest, constraint on extraterrestrial power beaming in that system. Until more extensive observations are made, the limited observation time and frequency coverage are not sufficiently broad in frequency and duration to produce firm conclusions. Such beams would be visible over large interstellar distances. This implies a new approach to the SETI search: instead of focusing on narrowband beacon transmissions generated by another civilization, look for more powerful beams with much wider bandwidth. This requires a new approach for their discovery by telescopes on Earth. Further studies of power beaming applications should be performed, potentially broadening the parameter space of the observable features that we have discussed here.

Bibliography of Aeronautics: 1928

NASA Technical Reports Server (NTRS)

Brockett, Paul

1928-01-01

This Bibliography of Aeronautics for 1928 covers the aeronautical literature published from January 1 to December 31, 1928. The first Bibliography of Aeronautics was published by the Smithsonian Institution as volume 55 of the Smithsonian Miscellaneous Collections and covered the material published prior to June 30, 1909. Supplementary volumes of the Bibliography of Aeronautics for the subsequent years have been published by the National Advisory Committee for Aeronautics. The last preceding volume was for the calendar year 1927. As in the previous volumes, citations of the publications of all nations are included in the languages in which these publications originally appeared. The arrangement is in dictionary form with author and subject entry, and one alphabetical arrangement. Detail in the matter of subject reference has been omitted on account of the cost of presentation, but an attempt has been made to give sufficient cross reference for research in special lines.

Bibliography of Aeronautics: 1926

NASA Technical Reports Server (NTRS)

Brockett, Paul

1928-01-01

This Bibliography of Aeronautics for 1926 covers the aeronautical literature published from January 1 to December 31, 1926. The first Bibliography of Aeronautics was published by the Smithsonian Institution as volume 55 of the Smithsonian Miscellaneous Collections and covered the material published prior to June 30, 1909. Supplementary volumes of the Bibliography of Aeronautics for the subsequent years have been published by the National Advisory Committee for Aeronautics. The last preceding volume was for the calendar year 1925. As in the previous volumes, citations of the publications of all nations are included in the languages in which these publications originally appeared. The arrangement is dictionary form with author find subject entry, and one alphabetical arrangement. Detail in the matter of subject reference has been omitted on aCC01.mt of the cost of presentation, but an attempt has been made to give sufficient cross reference for research in special lines.

Bibliography of Aeronautics, 1929

NASA Technical Reports Server (NTRS)

Brockett, Paul

1930-01-01

This Bibliography of Aeronautics for 1929 covers the aeronautical literature published from January 1 to December 31, 1929. The first Bibliography of Aeronautics was published by the Smithsonian Institution as Volume 55 of the Smithsonian Miscellaneous Collections and covered the material published prior to June 30, 1909. Supplementary volumes of the Bibliography of Aeronautics for the subsequent years have been published by the National Advisory Committee for Aeronautics. The last preceding volume was for the calendar year 1928. As in the previous volumes, citations of the pUblications of all nations are included in th.e languages in which. these publications originally appeared. The arrangement is in dictionary form with author and subject entry, and one alphabetical arrangement. Detail in the matter of subject reference has been omitted on account of the cost of presentation, but an attempt has been made to give sufficient cross reference for research in special lines.

Bibliography of Aeronautics: 1932

NASA Technical Reports Server (NTRS)

1935-01-01

This Bibliography of Aeronautics for 1932 covers the aeronautical literature published from January 1 to December 31, 1932. The first Bibliography of Aeronautics was published by the Smithsonian Institution as volume 55 of the Smithsonian Miscellaneous Collections and covered the material published prior to June 30, 1909. Supplementary volumes of the Bibliography of Aeronautics for the subsequent years have been published by the National Advisory Committee for Aeronautics. The last preceding volume was for the calendar year 1931. As in the previous volumes, citations of the publications of all nations are included in the languages in which these publications originally appeared. The arrangement is in dictionary form with author and subject entry and one alphabetical arrangement. Detail in the matter of subject reference has been omitted on account of the cost of presentation, but an attempt has been made to give sufficient cross-reference for research in special lines.

NASA Aeronautics Research: An Assessment

NASA Technical Reports Server (NTRS)

2008-01-01

The U.S. air transportation system is vital to the economic well-being and security of the United States. To support continued U.S. leadership in aviation, Congress and NASA requested that the National Research Council undertake a decadal survey of civil aeronautics research and technology (R&T) priorities that would help NASA fulfill its responsibility to preserve U.S. leadership in aeronautics technology. In 2006, the National Research Council published the Decadal Survey of Civil Aeronautics. That report presented a set of six strategic objectives for the next decade of aeronautics R&T, and it described 51 high-priority R&T challenges--characterized by five common themes--for both NASA and non-NASA researchers. The National Research Council produced the present report, which assesses NASA's Aeronautics Research Program, in response to the National Aeronautics and Space Administration Authorization Act of 2005 (Public Law 109-155). This report focuses on three sets of questions: 1. How well does NASA's research portfolio implement appropriate recommendations and address relevant high-priority research and technology challenges identified in the Decadal Survey of Civil Aeronautics? If gaps are found, what steps should be taken by the federal government to eliminate them? 2. How well does NASA's aeronautics research portfolio address the aeronautics research requirements of NASA, particularly for robotic and human space exploration? How well does NASA's aeronautics research portfolio address other federal government department/agency non-civil aeronautics research needs? If gaps are found, what steps should be taken by NASA and/or other parts of the federal government to eliminate them? 3. Will the nation have a skilled research workforce and research facilities commensurate with the requirements in (1) and (2) above? What critical improvements in workforce expertise and research facilities, if any, should NASA and the nation make to achieve the goals of NASA

Detectability of Wellbore CO2 Leakage using the Magnetotelluric Method

NASA Astrophysics Data System (ADS)

Yang, X.; Buscheck, T. A.; Mansoor, K.; Carroll, S.

2016-12-01

We assessed the effectiveness of the magnetotelluric (MT) method in detecting CO2 and brine leakage through a wellbore, which penetrates a CO2 storage reservoir, into overlying aquifers, 0 to 1720 m in depth, in support of the USDOE National Risk Assessment Partnership (NRAP) monitoring program. Synthetic datasets based on the Kimberlina site in the southern San Joaquin Basin, California were created using CO2 storage reservoir models, wellbore leakage models, and groundwater/geochemical models of the overlying aquifers. The species concentrations simulated with the groundwater/geochemical models were converted into bulk electrical conductivity (EC) distributions as the MT model input. Brine and CO2 leakage into the overlying aquifers increases ion concentrations, and thus results in an EC increase, which may be detected by the MT method. Our objective was to estimate and maximize the probability of leakage detection using the MT method. The MT method is an electromagnetic geophysical technique that images the subsurface EC distribution by measuring natural electric and magnetic fields in the frequency range from 0.01 Hz to 1 kHz with sensors on the ground surface. The ModEM software was used to predict electromagnetic responses from brine and CO2 leakage and to invert synthetic MT data for recovery of subsurface conductivity distribution. We are in the process of building 1000 simulations for ranges of permeability, leakage flux, and hydraulic gradient to study leakage detectability and to develop an optimization method to answer when, where and how an MT monitoring system should be deployed to maximize the probability of leakage detection. This work was sponsored by the USDOE Fossil Energy, National Energy Technology Laboratory, managed by Traci Rodosta and Andrea McNemar. This work was performed under the auspices of the USDOE by LLNL under contract DE-AC52-07NA27344. LLNL IM release number is LLNL-ABS-699276.

Nomenclature for aeronautics

NASA Technical Reports Server (NTRS)

1920-01-01

Report defines the principal terms which have come into use in the development of aeronautics. It was prepared in cooperation with a committee engaged upon a similar undertaking in Great Britain. As a result this nomenclature is in substantial agreement with the one which has been adopted by the aeronautical authorities of Great Britain.

NASA Radio Frequency Spectrum Management Manual

NASA Technical Reports Server (NTRS)

1989-01-01

The Radio Frequency (RF) Spectrum Management Manual sets forth procedures and guidelines for the management requirements for controlling the use of radio frequencies by the National Aeronautics and Space Administration. It is applicable to NASA Headquarters and field installations. NASA Management Instruction 1102.3 assigns the authority for management of radio frequencies for the National Aeronautics and Space Administration to the Associate Administrator for Space Operations, NASA Headquarters. This manual is issued in loose-leaf form and will be revised by page changes.

14 CFR 61.155 - Aeronautical knowledge.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Aeronautical knowledge. 61.155 Section 61.155 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED....155 Aeronautical knowledge. (a) General. The knowledge test for an airline transport pilot certificate...

14 CFR 61.155 - Aeronautical knowledge.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Aeronautical knowledge. 61.155 Section 61.155 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED....155 Aeronautical knowledge. (a) General. The knowledge test for an airline transport pilot certificate...

14 CFR 61.125 - Aeronautical knowledge.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Aeronautical knowledge. 61.125 Section 61.125 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED... Aeronautical knowledge. (a) General. A person who applies for a commercial pilot certificate must receive and...

14 CFR 61.125 - Aeronautical knowledge.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Aeronautical knowledge. 61.125 Section 61.125 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED... Aeronautical knowledge. (a) General. A person who applies for a commercial pilot certificate must receive and...

14 CFR 61.105 - Aeronautical knowledge.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Aeronautical knowledge. 61.105 Section 61.105 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED... Aeronautical knowledge. (a) General. A person who is applying for a private pilot certificate must receive and...

14 CFR 61.185 - Aeronautical knowledge.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Aeronautical knowledge. 61.185 Section 61.185 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED... Flight Instructors With a Sport Pilot Rating § 61.185 Aeronautical knowledge. (a) A person who is...

14 CFR 61.185 - Aeronautical knowledge.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Aeronautical knowledge. 61.185 Section 61.185 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED... Flight Instructors With a Sport Pilot Rating § 61.185 Aeronautical knowledge. (a) A person who is...

14 CFR 61.105 - Aeronautical knowledge.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Aeronautical knowledge. 61.105 Section 61.105 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED... Aeronautical knowledge. (a) General. A person who is applying for a private pilot certificate must receive and...

NASA thesaurus aeronautics vocabulary

NASA Technical Reports Server (NTRS)

1991-01-01

The controlled vocabulary used by the NASA Scientific and Technical Information effort to index documents in the area of aeronautics is presented. The terms comprise a subset of the 1988 edition of the NASA Thesaurus and its supplements issued through the end of 1990. The Aeronautics Vocabulary contains over 4700 terms presented in a hierarchical display format. In addition to aeronautics per se, the vocabulary covers supporting terminology from areas such as fluid dynamics, propulsion engineering, and test facilities and instrumentation.

Time reversal technique for gas leakage detection.

PubMed

Maksimov, A O; Polovinka, Yu A

2015-04-01

The acoustic remote sensing of subsea gas leakage traditionally uses sonars as active acoustic sensors and hydrophones picking up the sound generated by a leak as passive sensors. When gas leaks occur underwater, bubbles are produced and emit sound at frequencies intimately related to their sizes. The experimental implementation of an acoustic time-reversal mirror (TRM) is now well established in underwater acoustics. In the basic TRM experiment, a probe source emits a pulse that is received on an array of sensors, time reversed, and re-emitted. After time reversal, the resulting field focuses back at the probe position. In this study, a method for enhancing operation of the passive receiving system has been proposed by using it in the regime of TRM. Two factors, the local character of the acoustic emission signal caused by the leakage and a resonant nature of the bubble radiation at their birth, make particularly effective scattering with the conjugate wave (CW). Analytical calculations are performed for the scattering of CW wave on a single bubble when CW is formed by bubble birthing wail received on an array, time reversed, and re-emitted. The quality of leakage detection depends on the spatio-temporal distribution of ambient noise.

14 CFR 61.155 - Aeronautical knowledge.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Aeronautical knowledge. 61.155 Section 61....155 Aeronautical knowledge. (a) General. The knowledge test for an airline transport pilot certificate is based on the aeronautical knowledge areas listed in paragraph (c) of this section that are...

14 CFR 77.35 - Aeronautical studies.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Aeronautical studies. 77.35 Section 77.35... OBJECTS AFFECTING NAVIGABLE AIRSPACE Aeronautical Studies of Effect of Proposed Construction on Navigable Airspace § 77.35 Aeronautical studies. (a) The Regional Manager, Air Traffic Division of the region in...

14 CFR 77.35 - Aeronautical studies.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Aeronautical studies. 77.35 Section 77.35... OBJECTS AFFECTING NAVIGABLE AIRSPACE (Eff. until 1-18-11) Aeronautical Studies of Effect of Proposed Construction on Navigable Airspace § 77.35 Aeronautical studies. (a) The Regional Manager, Air Traffic Division...

Aeronautics in NACA and NASA

NASA Technical Reports Server (NTRS)

1991-01-01

Initiated in 1915, the National Advisory Committee for Aeronautics/National Aeronautics and Space Administration (NACA/NASA) aeronautical programs have been the keystone of a sustained U.S. Government, industry, and university research effort which has been a primary factor in the development of our remarkable air transportation systems, the country's largest positive trade balance component, and the world's finest military Air Force. This overview summarizes the flow of events, and the major trends, that have led from the NACA origins to the present NASA Aeronautics program, and indicates some important directions for the years ahead.

Aeronautical Science Course of Study.

ERIC Educational Resources Information Center

Southbay Union High School District, Redondo Beach, CA.

This revision of "Aeronautical Science Course of Study for California High Schools," first issued in 1967, is designed by and for the use of teachers of high school aeronautical courses. It differs from other aeronautical instructional materials in its emphasis on inquiry, exploration, and open-ended experimentation. The eleven units may be used…

Western Aeronautical Test Range

NASA Technical Reports Server (NTRS)

Sakahara, Robert D.

2008-01-01

NASA's Western Aeronautical Test Range (WATR) is a network of facilities used to support aeronautical research, science missions, exploration system concepts, and space operations. The WATR resides at NASA's Dryden Flight Research Center located at Edwards Air Force Base, California. The WATR is a part of NASA's Corporate Management of Aeronautical Facilities and funded by the Strategic Capability Asset Program (SCAP). It is managed by the Aeronautics Test Program (ATP) of the Aeronautics Research Mission Directorate (ARMD) to provide the right facility at the right time. NASA is a tenant on Edwards Air Force Base and has an agreement with the Air Force Flight Test Center to use the land and airspace controlled by the Department of Defense (DoD). The topics include: 1) The WATR supports a variety of vehicles; 2) Dryden shares airspace with the AFFTC; 3) Restricted airspace, corridors, and special use areas are available for experimental aircraft; 4) WATR Products and Services; 5) WATR Support Configuration; 6) Telemetry Tracking; 7) Time Space Positioning; 8) Video; 9) Voice Communication; 10) Mobile Operations Facilities; 11) Data Processing; 12) Mission Control Center; 13) Real-Time Data Analysis; and 14) Range Safety.

NASA's Role in Aeronautics: A Workshop. Volume 6: Aeronautical research

NASA Technical Reports Server (NTRS)

1981-01-01

While each aspect of its aeronautical technology program is important to the current preeminence of the United States in aeronautics, the most essential contributions of NASA derive from its research. Successes and challenges in NASA's efforts to improve civil and military aviation are discussed for the following areas: turbulence, noise, supercritical aerodynamics, computational aerodynamics, fuels, high temperature materials, composite materials, single crystal components, powder metallurgy, and flight controls. Spin offs to engineering and other sciences explored include NASTRAN, lubricants, and composites.

14 CFR 61.99 - Aeronautical experience.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Aeronautical experience. 61.99 Section 61.99 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIRMEN CERTIFICATION: PILOTS, FLIGHT INSTRUCTORS, AND GROUND INSTRUCTORS Recreational Pilots § 61.99...

14 CFR 61.125 - Aeronautical knowledge.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false Aeronautical knowledge. 61.125 Section 61.125 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED... principles of flight; (4) Meteorology to include recognition of critical weather situations, windshear...

14 CFR 61.125 - Aeronautical knowledge.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Aeronautical knowledge. 61.125 Section 61.125 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED... principles of flight; (4) Meteorology to include recognition of critical weather situations, windshear...

14 CFR 61.155 - Aeronautical knowledge.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false Aeronautical knowledge. 61.155 Section 61.155 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED... system of weather and NOTAM collection, dissemination, interpretation, and use; (4) Interpretation and...

Clinical score to predict the risk of bile leakage after liver resection.

PubMed

Kajiwara, Takahiro; Midorikawa, Yutaka; Yamazaki, Shintaro; Higaki, Tokio; Nakayama, Hisashi; Moriguchi, Masamichi; Tsuji, Shingo; Takayama, Tadatoshi

2016-05-06

In liver resection, bile leakage remains the most common cause of operative morbidity. In order to predict the risk of this complication on the basis of various factors, we developed a clinical score system to predict the potential risk of bile leakage after liver resection. We analyzed the postoperative course in 518 patients who underwent liver resection for malignancy to identify independent predictors of bile leakage, which was defined as "a drain fluid bilirubin concentration at least three times the serum bilirubin concentration on or after postoperative day 3," as proposed by the International Study Group of Liver Surgery. To confirm the robustness of the risk score system for bile leakage, we analyzed the independent series of 289 patients undergoing liver resection for malignancy. Among 81 (15.6 %) patients with bile leakage, 76 had grade A bile leakage, and five had grade C leakage and underwent reoperation. The median postoperative hospital stay was significantly longer in patients with bile leakage (median, 14 days; range, 8 to 34) than in those without bile leakage (11 days; 5 to 62; P = 0.001). There was no hepatic insufficiency or in-hospital death. The risk score model was based on the four independent predictors of postoperative bile leakage: non-anatomical resection (odds ratio, 3.16; 95 % confidence interval [CI], 1.72 to 6.07; P < 0.001), indocyanine green clearance rate (2.43; 1.32 to 7.76; P = 0.004), albumin level (2.29; 1.23 to 4.22; P = 0.01), and weight of resected specimen (1.97; 1.11 to 3.51; P = 0.02). When this risk score system was used to assign patients to low-, middle-, and high-risk groups, the frequency of bile leakage in the high-risk group was 2.64 (95 % CI, 1.12 to 6.41; P = 0.04) than that in the low-risk group. Among the independent series for validation, 4 (5.7 %), 16 (10.0 %), and 10 (16.6 %) patients in low-, middle, and high-risk groups were given a diagnosis of bile leakage after

Polarization leakage in epoch of reionization windows - II. Primary beam model and direction-dependent calibration

NASA Astrophysics Data System (ADS)

Asad, K. M. B.; Koopmans, L. V. E.; Jelić, V.; Ghosh, A.; Abdalla, F. B.; Brentjens, M. A.; de Bruyn, A. G.; Ciardi, B.; Gehlot, B. K.; Iliev, I. T.; Mevius, M.; Pandey, V. N.; Yatawatta, S.; Zaroubi, S.

2016-11-01

Leakage of diffuse polarized emission into Stokes I caused by the polarized primary beam of the instrument might mimic the spectral structure of the 21-cm signal coming from the epoch of reionization (EoR) making their separation difficult. Therefore, understanding polarimetric performance of the antenna is crucial for a successful detection of the EoR signal. Here, we have calculated the accuracy of the nominal model beam of Low Frequency ARray (LOFAR) in predicting the leakage from Stokes I to Q, U by comparing them with the corresponding leakage of compact sources actually observed in the 3C 295 field. We have found that the model beam has errors of ≤10 per cent on the predicted levels of leakage of ˜1 per cent within the field of view, I.e. if the leakage is taken out perfectly using this model the leakage will reduce to 10-3 of the Stokes I flux. If similar levels of accuracy can be obtained in removing leakage from Stokes Q, U to I, we can say, based on the results of our previous paper, that the removal of this leakage using this beam model would ensure that the leakage is well below the expected EoR signal in almost the whole instrumental k-space of the cylindrical power spectrum. We have also shown here that direction-dependent calibration can remove instrumentally polarized compact sources, given an unpolarized sky model, very close to the local noise level.

Aeronautical Engineering: 1983 cumulative index

NASA Technical Reports Server (NTRS)

1984-01-01

This bibliography is a cumulative index to the abstracts contained in NASA SP-7037 (158) through NASA SP-7037 (169) of Aeronautical Engineering: A Continuing Bibliography. NASA SP-7037 and its supplements have been compiled through the cooperative efforts of the American Institute of Aeronautics and Astronautics (AIAA) and the National Aeronautics and Space Administration (NASA). This cumulative index includes subject, personal author, corporate source, contract, report number, and accession number indexes.

Techniques Analysis of the Interference Suppression Algorithm in Broadband Aeronautical Multi-carrier Communication System

NASA Astrophysics Data System (ADS)

Li, Dong-xia; Ye, Qian-wen

Out-of-band radiation suppression algorithm must be used efficiently for broadband aeronautical communication system in order not to interfere the operation of the existing systems in aviation L-Band. Based on the simple introduction of the broadband aeronautical multi-carrier communication (B-AMC) system model, several sidelobe suppression techniques in orthogonal frequency multiplexing (OFDM) system are presented and analyzed so as to find a suitable algorithm for B-AMC system in this paper. Simulation results show that raise-cosine function windowing can suppress the out-of-band radiation of B-AMC system effectively.

Improving stopping construction to minimize leakage

PubMed Central

Grau, Roy H.; Mazzella, Andrew L.; Martikainen, Anu L.

2015-01-01

The proper sealing of stoppings is an important step in reducing leakage from the intake to the return airways. Leakage and the subsequent loss of ventilation resulting from improperly sealed stoppings can lead to unhealthy and unsafe working conditions. The research presented in this paper investigates the total leakage of a stopping, including air leakage through the stopping, at the stopping perimeter, and through the coalbed. The study also examines sealing considerations for stoppings that are constructed under roof control screen, the effects that wooden wedges had on inhibiting efficient application of polyurethane foam sealant, and airflow leakage through the surrounding coal. The work involved building a stopping in a dead end room of the NIOSH Safety Research Coal Mine and then pressurising the room using compressed air. Stopping leakage was evaluated by measuring air pressure loss in the enclosed room due to the air leakage. Part of the research utilises a diluted soap solution that was applied to the stopping and the surrounding coal to detect air leakage signified by bubble formations. The results show that stopping leakage can be minimised with proper sealing PMID:26379366

14 CFR 61.105 - Aeronautical knowledge.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false Aeronautical knowledge. 61.105 Section 61.105 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED...) Recognition of critical weather situations from the ground and in flight, windshear avoidance, and the...

14 CFR 61.105 - Aeronautical knowledge.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Aeronautical knowledge. 61.105 Section 61.105 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED...) Recognition of critical weather situations from the ground and in flight, windshear avoidance, and the...

NASA's aeronautics research and technology base

NASA Technical Reports Server (NTRS)

1979-01-01

NASA's research technology base in aeronautics is assessed in terms of: (1) US aeronautical technology needs and requirements in the future; (2) objectives of the aeronautics program; (3) magnitude and scope of the program; and (4) research and technology performed by NASA and other research organizations.

14 CFR 61.97 - Aeronautical knowledge.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Aeronautical knowledge. 61.97 Section 61.97 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIRMEN... knowledge. (a) General. A person who applies for a recreational pilot certificate must receive and log...

14 CFR 61.97 - Aeronautical knowledge.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Aeronautical knowledge. 61.97 Section 61.97 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIRMEN... knowledge. (a) General. A person who applies for a recreational pilot certificate must receive and log...

14 CFR 61.97 - Aeronautical knowledge.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Aeronautical knowledge. 61.97 Section 61.97 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIRMEN... using pilotage with the aid of a magnetic compass; (5) Recognition of critical weather situations from...

Review of Aeronautical Wind Tunnel Facilities

NASA Technical Reports Server (NTRS)

1988-01-01

The nation's aeronautical wind tunnel facilities constitute a valuable technological resource and make a significant contribution to the global supremacy of U.S. aircraft, both civil and military. At the request of NASA, the National Research Council's Aeronautics and Space Engineering Board organized a commitee to review the state of repair, adequacy, and future needs of major aeronautical wind tunnel facilities in meeting national goals. The comittee identified three main areas where actions are needed to sustain the capability of NASA's aeronautical wind tunnel facilities to support the national aeronautical research and development activities: tunnel maintenance and upgrading, productivity enhancement, and accommodation of new requirements (particularly in hypersonics). Each of these areas are addressed and the committee recommendations for appropriate actions presented.

Aeronautics. America in Space: The First Decade.

ERIC Educational Resources Information Center

Anderton, David A.

The major research and developments in aeronautics during the late 1950's and 1960's are reviewed descriptively with a minimum of technical content. Topics covered include aeronautical research, aeronautics in NASA, The National Advisory Committee for Aeronautics, the X-15 Research Airplane, variable-sweep wing design, the Supersonic Transport…

Questions & Answers about Aeronautics and Space.

ERIC Educational Resources Information Center

National Aeronautics and Space Administration, Washington, DC.

Answers to 27 questions about aeronautics, space, and the National Aeronautics and Space Administration (NASA) are provided in this pamphlet. Among the topics dealt with in these questions are: costs of the space program; NASA's role in aeronautics; benefits received from the space program; why the United States hasn't developed means of rescuing…

Zero-Point Energy Leakage in Quantum Thermal Bath Molecular Dynamics Simulations.

PubMed

Brieuc, Fabien; Bronstein, Yael; Dammak, Hichem; Depondt, Philippe; Finocchi, Fabio; Hayoun, Marc

2016-12-13

The quantum thermal bath (QTB) has been presented as an alternative to path-integral-based methods to introduce nuclear quantum effects in molecular dynamics simulations. The method has proved to be efficient, yielding accurate results for various systems. However, the QTB method is prone to zero-point energy leakage (ZPEL) in highly anharmonic systems. This is a well-known problem in methods based on classical trajectories where part of the energy of the high-frequency modes is transferred to the low-frequency modes leading to a wrong energy distribution. In some cases, the ZPEL can have dramatic consequences on the properties of the system. Thus, we investigate the ZPEL by testing the QTB method on selected systems with increasing complexity in order to study the conditions and the parameters that influence the leakage. We also analyze the consequences of the ZPEL on the structural and vibrational properties of the system. We find that the leakage is particularly dependent on the damping coefficient and that increasing its value can reduce and, in some cases, completely remove the ZPEL. When using sufficiently high values for the damping coefficient, the expected energy distribution among the vibrational modes is ensured. In this case, the QTB method gives very encouraging results. In particular, the structural properties are well-reproduced. The dynamical properties should be regarded with caution although valuable information can still be extracted from the vibrational spectrum, even for large values of the damping term.

Mobile-ip Aeronautical Network Simulation Study

NASA Technical Reports Server (NTRS)

Ivancic, William D.; Tran, Diepchi T.

2001-01-01

NASA is interested in applying mobile Internet protocol (mobile-ip) technologies to its space and aeronautics programs. In particular, mobile-ip will play a major role in the Advanced Aeronautic Transportation Technology (AATT), the Weather Information Communication (WINCOMM), and the Small Aircraft Transportation System (SATS) aeronautics programs. This report presents the results of a simulation study of mobile-ip for an aeronautical network. The study was performed to determine the performance of the transmission control protocol (TCP) in a mobile-ip environment and to gain an understanding of how long delays, handoffs, and noisy channels affect mobile-ip performance.

Leakage and spillover effects of forest management on carbon storage: theoretical insights from a simple model

NASA Astrophysics Data System (ADS)

Magnani, Federico; Dewar, Roderick C.; Borghetti, Marco

2009-04-01

Leakage (spillover) refers to the unintended negative (positive) consequences of forest carbon (C) management in one area on C storage elsewhere. For example, the local C storage benefit of less intensive harvesting in one area may be offset, partly or completely, by intensified harvesting elsewhere in order to meet global timber demand. We present the results of a theoretical study aimed at identifying the key factors determining leakage and spillover, as a prerequisite for more realistic numerical studies. We use a simple model of C storage in managed forest ecosystems and their wood products to derive approximate analytical expressions for the leakage induced by decreasing the harvesting frequency of existing forest, and the spillover induced by establishing new plantations, assuming a fixed total wood production from local and remote (non-local) forests combined. We find that leakage and spillover depend crucially on the growth rates, wood product lifetimes and woody litter decomposition rates of local and remote forests. In particular, our results reveal critical thresholds for leakage and spillover, beyond which effects of forest management on remote C storage exceed local effects. Order of magnitude estimates of leakage indicate its potential importance at global scales.

Predicting Envelope Leakage in Attached Dwellings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Faakye, O.; Arena, L.; Griffiths, D.

2013-07-01

The most common method for measuring air leakage is to use a single blower door to pressurize and/or depressurize the test unit. In detached housing, the test unit is the entire home and the single blower door measures air leakage to the outside. In attached housing, this 'single unit', 'total', or 'solo' test method measures both the air leakage between adjacent units through common surfaces as well air leakage to the outside. Measuring and minimizing this total leakage is recommended to avoid indoor air quality issues between units, reduce energy losses to the outside, reduce pressure differentials between units, andmore » control stack effect. However, two significant limitations of the total leakage measurement in attached housing are: for retrofit work, if total leakage is assumed to be all to the outside, the energy benefits of air sealing can be significantly over predicted; for new construction, the total leakage values may result in failing to meet an energy-based house tightness program criterion. The scope of this research is to investigate an approach for developing a viable simplified algorithm that can be used by contractors to assess energy efficiency program qualification and/or compliance based upon solo test results.« less

Shroud leakage flow discouragers

DOEpatents

Bailey, Jeremy Clyde; Bunker, Ronald Scott

2002-01-01

A turbine assembly includes a plurality of rotor blades comprising a root portion, an airfoil having a pressure sidewall and a suction sidewall, and a top portion having a cap. An outer shroud is concentrically disposed about said rotor blades, said shroud in combination with said tip portions defining a clearance gap. At least one circumferential shroud leakage discourager is disposed within the shroud. The leakage discourager(s) increase the flow resistance and thus reduce the flow of hot gas flow leakage for a given pressure differential across the clearance gap to improve overall turbine efficiency.

Civilian Aeronautical Futures - The Responsibly Imaginable

NASA Technical Reports Server (NTRS)

Bushnell, Dennis M.

2006-01-01

Since 1940 Aeronautics has had an immense impact upon Global Human lifestyles and affairs - in both the Civilian and Military arenas. During this period Long distance Train and Ship passenger transport were largely supplanted by Air Travel and Aviation assumed a dominant role in warfare. The early 1940 s to the mid 1970 s was a particularly productive period in terms of Aeronautical Technology. What is interesting is that, since the mid 1970 s, the rate of Aeronautical Technological Progress has been far slower, the basic technology in nearly all of our current Aero Systems dates from the mid 70 s or earlier. This is especially true in terms of Configuration Aerodynamics, Aeronautics appears to have "settled" on the 707, double delta and rotary wing as the approach of choice for Subsonic long haul, supersonic cruise and VTOL respectively. Obviously there have been variants and some niche digression from this/these but in the main Aeronautics, particularly civilian Aeronautics, has become a self-professed "mature", Increasingly "Commodity", Industry. The Industry is far along an existing/deployed technology curve and focused, now for decades, on incremental/evolutionary change - largely Appliers vs. developers of technology. This is, of course, in sharp contrast to the situation in the early-to-later 20th century where Aeronautics was viewed as A Major Technological Engine, much the way IT/Bio/Nano/Energetics/Quantum Technologies are viewed today. A search for Visionary Aeronautical "Futures" papers/projections indicates a decided dearth thereof over the last 20 plus years compared to the previous quarter Century. Aeronautics is part of Aerospace and Aerospace [including Aeronautics] has seen major cutbacks over the last decades. Some numbers for the U.S. Aerospace Industry serve as examples. Order of 600,000 jobs lost, with some 180,000 more on the block over the next 10 years. Approximately 25% of the Aerospace workforce is eligible to retire and the average

14 CFR 1215.107 - User data security and frequency authorizations.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false User data security and frequency authorizations. 1215.107 Section 1215.107 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION TRACKING AND DATA RELAY SATELLITE SYSTEM (TDRSS) Use and Reimbursement Policy for Non-U.S. Government Users...

14 CFR 1215.107 - User data security and frequency authorizations.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 5 2011-01-01 2010-01-01 true User data security and frequency authorizations. 1215.107 Section 1215.107 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION TRACKING AND DATA RELAY SATELLITE SYSTEM (TDRSS) Use and Reimbursement Policy for Non-U.S. Government Users...

16 CFR 1507.5 - Pyrotechnic leakage.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Pyrotechnic leakage. 1507.5 Section 1507.5... FIREWORKS DEVICES § 1507.5 Pyrotechnic leakage. The pyrotechnic chamber in fireworks devices shall be sealed in a manner that prevents leakage of the pyrotechnic composition during shipping, handling, and...

16 CFR 1507.5 - Pyrotechnic leakage.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 16 Commercial Practices 2 2011-01-01 2011-01-01 false Pyrotechnic leakage. 1507.5 Section 1507.5... FIREWORKS DEVICES § 1507.5 Pyrotechnic leakage. The pyrotechnic chamber in fireworks devices shall be sealed in a manner that prevents leakage of the pyrotechnic composition during shipping, handling, and...

77 FR 61432 - NASA Advisory Council; Aeronautics Committee; Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-09

... NATIONAL AERONAUTICS AND SPACE ADMINISTRATION [Notice 12-080] NASA Advisory Council; Aeronautics Committee; Meeting AGENCY: National Aeronautics and Space Administration. ACTION: Notice of Meeting. SUMMARY... Aeronautics and Space Administration announces a meeting of the Aeronautics Committee of the NASA Advisory...

78 FR 69885 - NASA Advisory Council; Aeronautics Committee; Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-21

... NATIONAL AERONAUTICS AND SPACE ADMINISTRATION [Notice: 13-133] NASA Advisory Council; Aeronautics... Aeronautics and Space Administration announces a meeting of the Aeronautics Committee of the NASA Advisory... INFORMATION CONTACT: Ms. Susan L. Minor, Executive Secretary for the Aeronautics Committee, NASA Headquarters...

40 CFR 264.222 - Action leakage rate.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 25 2010-07-01 2010-07-01 false Action leakage rate. 264.222 Section... Impoundments § 264.222 Action leakage rate. (a) The Regional Administrator shall approve an action leakage rate for surface impoundment units subject to § 264.221 (c) or (d). The action leakage rate is the maximum...

40 CFR 264.252 - Action leakage rate.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 25 2010-07-01 2010-07-01 false Action leakage rate. 264.252 Section... Piles § 264.252 Action leakage rate. (a) The Regional Administrator shall approve an action leakage rate for waste pile units subject to § 264.251(c) or (d). The action leakage rate is the maximum design...

40 CFR 264.302 - Action leakage rate.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 25 2010-07-01 2010-07-01 false Action leakage rate. 264.302 Section... § 264.302 Action leakage rate. (a) The Regional Administrator shall approve an action leakage rate for landfill units subject to § 264.301(c) or (d). The action leakage rate is the maximum design flow rate that...

NASA aeronautics

NASA Technical Reports Server (NTRS)

Anderton, D. A.

1982-01-01

Aeronautical research programs are discussed in relation to research methods and the status of the programs. The energy efficient aircraft, STOL aircraft and general aviation aircraft are considered. Aerodynamic concepts, rotary wing aircraft, aircraft safety, noise reduction, and aircraft configurations are among the topics included.

47 CFR 87.241 - Frequencies.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Frequencies. 87.241 Section 87.241 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES AVIATION SERVICES Aeronautical Multicom Stations § 87.241 Frequencies. (a) 121.500 MHz: emergency and distress only; (b) 122.850...

Interference Analysis for an Aeronautical Mobile Airport Communications System

NASA Technical Reports Server (NTRS)

Wilson, Jeffrey D.; Kercewski, Robert J.

2010-01-01

The next generation of aeronautical communications for airport surface applications has been identified through a NASA research program and an international collaborative future communications study. The result, endorsed by both the United States and European regulatory agencies is called AeroMACS (Aeronautical Mobile Airport Communications System) and is based upon the IEEE 802.16e mobile wireless standard. Coordinated efforts to develop appropriate aviation standards for the AeroMACS system are now underway within RTCA (United States) and Eurocae (Europe). AeroMACS will be implemented in a recently allocated frequency band, 5091- 5150 MHz. As this band is also occupied by fixed satellite service uplinks, AeroMACS must be designed to avoid interference with this incumbent service. The aspects of AeroMACS operation that present potential interference to the fixed satellite service are under analysis in order to enable the definition of standards that assure that such interference will be avoided. The NASA Glenn Research Center has been involved in this analysis, and the first results of modeling and simulation efforts directed at this analysis are the subject of this paper.12

Interference Analysis for an Aeronautical Mobile Airport Communications System

NASA Technical Reports Server (NTRS)

Wilson, Jeffrey D.; Kerczewski, Robert J.

2011-01-01

The next generation of aeronautical communications for airport surface applications has been identified through a NASA research program and an international collaborative future communications study. The result, endorsed by both the United States and European regulatory agencies is called AeroMACS (Aeronautical Mobile Airport Communications System) and is based upon the IEEE 802.16e mobile wireless standard. Coordinated efforts to develop appropriate aviation standards for the AeroMACS system are now underway within RTCA (United States) and Eurocae (Europe). AeroMACS will be implemented in a recently allocated frequency band, 5091-5150 MHz. As this band is also occupied by fixed satellite service uplinks, AeroMACS must be designed to avoid interference with this incumbent service. The aspects of AeroMACS operation that present potential interference to the fixed satellite service are under analysis in order to enable the definition of standards that assure that such interference will be avoided. The NASA Glenn Research Center has been involved in this analysis, and the first results of modeling and simulation efforts directed at this analysis are the subject of this presentation.

14 CFR 61.97 - Aeronautical knowledge.

Code of Federal Regulations, 2012 CFR

2012-01-01

... “Aeronautical Information Manual” and FAA advisory circulars; (4) Use of aeronautical charts for VFR navigation using pilotage with the aid of a magnetic compass; (5) Recognition of critical weather situations from...

Bibliography of Aeronautics, 1920-1921

NASA Technical Reports Server (NTRS)

Brockett, Paul

1925-01-01

This work covers the literatme published from January 1, 1920, to December 31, 1921, and continues the work of the Smithsonian Institution issued as Volume 55 of the Smithsonian Miscellaneous Collections, which covered the material published prior to June 30, 1909, and the work of Lhe National Advisory Committee for Aeronautics as published in the Bibliography of Aeronautics for the years 1909 to 1916 and 1917 to 1919. As in the Smithsonian volume and in the Bibliography of Aeronautics for the years 1909 to 1916 and 1917 to 1919, citations of the publications of all nations have been included in the languages in which these publications originally appeared. The arrangement is in dictionary form with author and subject entry and one alphabetical arrangement. Detail in the matter of subject reference has been omitted on account of the cost of presentation, but an attempt has been made to give sufficient cross reference for research in special lines. The National Advisory Committee for Aeronautics will next present a bibliography for the year 1922.

1997 NASA Academy in Aeronautics

NASA Technical Reports Server (NTRS)

Andrisani, Dominick, II

1998-01-01

The NASA Academy in Aeronautics at the Dryden Flight Research Center (DFRC) was a ten-week summer leadership training program conducted for the first time in the summer of 1997. Funding was provided by a contract between DFRC and Purdue University. Mr. Lee Duke of DFRC was the contract monitor, and Professor Dominick Andrisani was the principal investigator. Five student research associates participated in the program. Biographies of the research associates are given in Appendix 1. Dominick Andrisani served as Dean of the NASA Academy in Aeronautics. NASA Academy in Aeronautics is a unique summer institute of higher learning that endeavors to provide insight into all of the elements that make NASA aeronautical research possible. At the same time the Academy assigns the research associate to be mentored by one of NASA!s best researchers so that they can contribute towards an active flight research program. Aeronautical research and development are an investment in the future, and NASA Academy is an investment in aeronautical leaders of the future. The Academy was run by the Indiana Space Grant Consortium at Purdue in strategic partnership with the National Space Grant College and Fellowship Program. Research associates at the Academy were selected with help from the Space Grant Consortium that sponsored the research associate. Research associate stipend and travel to DFRC were paid by the students' Space Grant Consortium. All other student expenses were paid by the Academy. Since the Academy at DFRC had only five students the opportunity for individual growth and attention was unique in the country. About 30% of the working time and most of the social time of the students were be spent as a "group" or "team." This time was devoted to exchange of ideas, on forays into the highest levels of decision making, and in executing aeronautical research. This was done by interviewing leaders throughout the aerospace industry, seminars, working dinners, and informal

A new leakage measurement method for damaged seal material

NASA Astrophysics Data System (ADS)

Wang, Shen; Yao, Xue Feng; Yang, Heng; Yuan, Li; Dong, Yi Feng

2018-07-01

In this paper, a new leakage measurement method based on the temperature field and temperature gradient field is proposed for detecting the leakage location and measuring the leakage rate in damaged seal material. First, a heat transfer leakage model is established, which can calculate the leakage rate based on the temperature gradient field near the damaged zone. Second, a finite element model of an infinite plate with a damaged zone is built to calculate the leakage rate, which fits the simulated leakage rate well. Finally, specimens in a tubular rubber seal with different damage shapes are used to conduct the leakage experiment, validating the correctness of this new measurement principle for the leakage rate and the leakage position. The results indicate the feasibility of the leakage measurement method for damaged seal material based on the temperature gradient field from infrared thermography.

Compressibility Effects in Aeronautical Engineering

NASA Technical Reports Server (NTRS)

Stack, John

1941-01-01

Compressible-flow research, while a relatively new field in aeronautics, is very old, dating back almost to the development of the first firearm. Over the last hundred years, researches have been conducted in the ballistics field, but these results have been of practically no use in aeronautical engineering because the phenomena that have been studied have been the more or less steady supersonic condition of flow. Some work that has been done in connection with steam turbines, particularly nozzle studies, has been of value, In general, however, understanding of compressible-flow phenomena has been very incomplete and permitted no real basis for the solution of aeronautical engineering problems in which.the flow is likely to be unsteady because regions of both subsonic and supersonic speeds may occur. In the early phases of the development of the airplane, speeds were so low that the effects of compressibility could be justifiably ignored. During the last war and immediately after, however, propellers exhibited losses in efficiency as the tip speeds approached the speed of sound, and the first experiments of an aeronautical nature were therefore conducted with propellers. Results of these experiments indicated serious losses of efficiency, but aeronautical engineers were not seriously concerned at the time became it was generally possible. to design propellers with quite low tip. speeds. With the development of new engines having increased power and rotational speeds, however, the problems became of increasing importance.

Effects of breathing frequency and flow rate on the total inward leakage of an elastomeric half-mask donned on an advanced manikin headform.

PubMed

He, Xinjian; Grinshpun, Sergey A; Reponen, Tiina; McKay, Roy; Bergman, Michael S; Zhuang, Ziqing

2014-03-01

The objective of this study was to investigate the effects of breathing frequency and flow rate on the total inward leakage (TIL) of an elastomeric half-mask donned on an advanced manikin headform and challenged with combustion aerosols. An elastomeric half-mask respirator equipped with P100 filters was donned on an advanced manikin headform covered with life-like soft skin and challenged with aerosols originated by burning three materials: wood, paper, and plastic (polyethylene). TIL was determined as the ratio of aerosol concentrations inside (C in) and outside (C out) of the respirator (C in/C out) measured with a nanoparticle spectrometer operating in the particle size range of 20-200nm. The testing was performed under three cyclic breathing flows [mean inspiratory flow (MIF) of 30, 55, and 85 l/min] and five breathing frequencies (10, 15, 20, 25, and 30 breaths/min). A completely randomized factorial study design was chosen with four replicates for each combination of breathing flow rate and frequency. Particle size, MIF, and combustion material had significant (P < 0.001) effects on TIL regardless of breathing frequency. Increasing breathing flow decreased TIL. Testing with plastic aerosol produced higher mean TIL values than wood and paper aerosols. The effect of the breathing frequency was complex. When analyzed using all combustion aerosols and MIFs (pooled data), breathing frequency did not significantly (P = 0.08) affect TIL. However, once the data were stratified according to combustion aerosol and MIF, the effect of breathing frequency became significant (P < 0.05) for all MIFs challenged with wood and paper combustion aerosols, and for MIF = 30 l/min only when challenged with plastic combustion aerosol. The effect of breathing frequency on TIL is less significant than the effects of combustion aerosol and breathing flow rate for the tested elastomeric half-mask respirator. The greatest TIL occurred when challenged with plastic aerosol at 30 l/min and

Dynamic SVL and body bias for low leakage power and high performance in CMOS digital circuits

NASA Astrophysics Data System (ADS)

Deshmukh, Jyoti; Khare, Kavita

2012-12-01

In this article, a new complementary metal oxide semiconductor design scheme called dynamic self-controllable voltage level (DSVL) is proposed. In the proposed scheme, leakage power is controlled by dynamically disconnecting supply to inactive blocks and adjusting body bias to further limit leakage and to maintain performance. Leakage power measurements at 1.8 V, 75°C demonstrate power reduction by 59.4% in case of 1 bit full adder and by 43.0% in case of a chain of four inverters using SVL circuit as a power switch. Furthermore, we achieve leakage power reduction by 94.7% in case of 1 bit full adder and by 91.8% in case of a chain of four inverters using dynamic body bias. The forward body bias of 0.45 V applied in active mode improves the maximum operating frequency by 16% in case of 1 bit full adder and 5.55% in case of a chain of inverters. Analysis shows that additional benefits of using the DSVL and body bias include high performance, low leakage power consumption in sleep mode, single threshold implementation and state retention even in standby mode.

Aeronautical Engineering: A continuing bibliography

NASA Technical Reports Server (NTRS)

1982-01-01

This bibliography lists 347 reports, articles and other documents introduced into the scientific and technical information system. Documents on the engineering and theoretical aspects of design, construction, evaluation, testing, operation, and performance of aircraft (including aircraft engines) and associated compounds, equipment, and systems are included. Research and development in aerodynamics, aeronautics and ground support equipment for aeronautical vehicles are also included.

47 CFR 1.1705 - Forms; electronic and manual filing.

Code of Federal Regulations, 2010 CFR

2010-10-01

... with the basic signal leakage performance criteria. (2) FCC Form 321, Aeronautical Frequency... time the data entry is made. (2) Attachments to applications must be uploaded along with the...) Forms 320, 321, 322, 324, 325, and 327 may be filed manually. (2) Manual filings must be submitted to...

47 CFR 1.1705 - Forms; electronic and manual filing.

Code of Federal Regulations, 2011 CFR

2011-10-01

... with the basic signal leakage performance criteria. (2) FCC Form 321, Aeronautical Frequency... time the data entry is made. (2) Attachments to applications must be uploaded along with the...) Forms 320, 321, 322, 324, 325, and 327 may be filed manually. (2) Manual filings must be submitted to...

Ensuring US National Aeronautics Test Capabilities

NASA Technical Reports Server (NTRS)

Marshall, Timothy J.

2010-01-01

U.S. leadership in aeronautics depends on ready access to technologically advanced, efficient, and affordable aeronautics test capabilities. These systems include major wind tunnels and propulsion test facilities and flight test capabilities. The federal government owns the majority of the major aeronautics test capabilities in the United States, primarily through the National Aeronautics and Space Administration (NASA) and the Department of Defense (DoD). However, changes in the Aerospace landscape, primarily the decrease in demand for testing over the last 20 years required an overarching strategy for management of these national assets. Therefore, NASA established the Aeronautics Test Program (ATP) as a two-pronged strategic initiative to: (1) retain and invest in NASA aeronautics test capabilities considered strategically important to the agency and the nation, and (2) establish a strong, high level partnership with the DoD. Test facility utilization is a critical factor for ATP because it relies on user occupancy fees to recover a substantial part of the operations costs for its facilities. Decreasing utilization is an indicator of excess capacity and in some cases low-risk redundancy (i.e., several facilities with basically the same capability and overall low utilization). However, low utilization does not necessarily translate to lack of strategic importance. Some facilities with relatively low utilization are nonetheless vitally important because of the unique nature of the capability and the foreseeable aeronautics testing needs. Unfortunately, since its inception, the customer base for ATP has continued to shrink. Utilization of ATP wind tunnels has declined by more than 50% from the FY 2006 levels. This significant decrease in customer usage is attributable to several factors, including the overall decline in new programs and projects in the aerospace sector; the impact of computational fluid dynamics (CFD) on the design, development, and research

49 CFR 192.723 - Distribution systems: Leakage surveys.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 3 2014-10-01 2014-10-01 false Distribution systems: Leakage surveys. 192.723... Distribution systems: Leakage surveys. (a) Each operator of a distribution system shall conduct periodic leakage surveys in accordance with this section. (b) The type and scope of the leakage control program...

49 CFR 192.723 - Distribution systems: Leakage surveys.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 3 2012-10-01 2012-10-01 false Distribution systems: Leakage surveys. 192.723... Distribution systems: Leakage surveys. (a) Each operator of a distribution system shall conduct periodic leakage surveys in accordance with this section. (b) The type and scope of the leakage control program...

49 CFR 192.723 - Distribution systems: Leakage surveys.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 3 2011-10-01 2011-10-01 false Distribution systems: Leakage surveys. 192.723... Distribution systems: Leakage surveys. (a) Each operator of a distribution system shall conduct periodic leakage surveys in accordance with this section. (b) The type and scope of the leakage control program...

49 CFR 192.723 - Distribution systems: Leakage surveys.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 3 2013-10-01 2013-10-01 false Distribution systems: Leakage surveys. 192.723... Distribution systems: Leakage surveys. (a) Each operator of a distribution system shall conduct periodic leakage surveys in accordance with this section. (b) The type and scope of the leakage control program...

49 CFR 192.723 - Distribution systems: Leakage surveys.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 3 2010-10-01 2010-10-01 false Distribution systems: Leakage surveys. 192.723... Distribution systems: Leakage surveys. (a) Each operator of a distribution system shall conduct periodic leakage surveys in accordance with this section. (b) The type and scope of the leakage control program...

76 FR 16643 - NASA Advisory Council; Aeronautics Committee; Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-24

... NATIONAL AERONAUTICS AND SPACE ADMINISTRATION [Notice (11-024)] NASA Advisory Council; Aeronautics... Aeronautics and Space Administration announces a meeting of the Aeronautics Committee of the NASA Advisory.... ADDRESSES: Thursday, April 14, 2011--NASA Dryden Flight Research Center (DFRC), Lilly Drive Building 4825...

76 FR 58843 - NASA Advisory Council; Aeronautics Committee; Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-22

... NATIONAL AERONAUTICS AND SPACE ADMINISTRATION [Notice 11-082] NASA Advisory Council; Aeronautics... Aeronautics and Space Administration announces a meeting of the Aeronautics Committee of the NASA Advisory... Headquarters, Washington, DC 20546, (202) 358-0566, or [email protected]nasa.gov . SUPPLEMENTARY INFORMATION: The...

75 FR 41240 - NASA Advisory Council; Aeronautics Committee; Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-15

... NATIONAL AERONAUTICS AND SPACE ADMINISTRATION [Notice (10-079)] NASA Advisory Council; Aeronautics... Aeronautics and Space Administration announces a meeting of the Aeronautics Committee of the NASA Advisory....m. to 4 p.m. (local time). ADDRESSES: NASA Glenn Research Center, Building 15, Small Dining...

Simulation of leakage through mechanical sealing device

NASA Astrophysics Data System (ADS)

Tikhomorov, V. P.; Gorlenko, O. A.; Izmerov, M. A.

2018-03-01

The procedure of mathematical modeling of leakage through the mechanical seal taking into account waviness and roughness is considered. The percolation process is represented as the sum of leakages through a gap between wavy surfaces and percolation through gaps formed by fractal roughness, i.e. the total leakage is determined by the slot model and filtration leakage. Dependences of leaks on the contact pressure of corrugated and rough surfaces of the mechanical seal elements are presented.

75 FR 17166 - NASA Advisory Council; Aeronautics Committee; Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-05

... NATIONAL AERONAUTICS AND SPACE ADMINISTRATION [Notice (10-038)] NASA Advisory Council; Aeronautics... Aeronautics and Space Administration announces a meeting of the Aeronautics Committee of the NASA Advisory... a.m. to 1 p.m.; Eastern Daylight Time. ADDRESSES: NASA Langley Research Center, Building 1219, Room...

78 FR 10640 - NASA Advisory Council; Aeronautics Committee; Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-14

... NATIONAL AERONAUTICS AND SPACE ADMINISTRATION [Notice (13-010)] NASA Advisory Council; Aeronautics... Aeronautics and Space Administration announces a meeting of the Aeronautics Committee of the NASA Advisory..., or [email protected]nasa.gov . SUPPLEMENTARY INFORMATION: The meeting will be open to the public up to...

49 CFR 192.706 - Transmission lines: Leakage surveys.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 3 2010-10-01 2010-10-01 false Transmission lines: Leakage surveys. 192.706... Transmission lines: Leakage surveys. Leakage surveys of a transmission line must be conducted at intervals not... transports gas in conformity with § 192.625 without an odor or odorant, leakage surveys using leak detector...

49 CFR 192.706 - Transmission lines: Leakage surveys.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 3 2014-10-01 2014-10-01 false Transmission lines: Leakage surveys. 192.706... Transmission lines: Leakage surveys. Leakage surveys of a transmission line must be conducted at intervals not... transports gas in conformity with § 192.625 without an odor or odorant, leakage surveys using leak detector...

49 CFR 192.706 - Transmission lines: Leakage surveys.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 3 2013-10-01 2013-10-01 false Transmission lines: Leakage surveys. 192.706... Transmission lines: Leakage surveys. Leakage surveys of a transmission line must be conducted at intervals not... transports gas in conformity with § 192.625 without an odor or odorant, leakage surveys using leak detector...

49 CFR 192.706 - Transmission lines: Leakage surveys.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 3 2012-10-01 2012-10-01 false Transmission lines: Leakage surveys. 192.706... Transmission lines: Leakage surveys. Leakage surveys of a transmission line must be conducted at intervals not... transports gas in conformity with § 192.625 without an odor or odorant, leakage surveys using leak detector...

49 CFR 192.706 - Transmission lines: Leakage surveys.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 3 2011-10-01 2011-10-01 false Transmission lines: Leakage surveys. 192.706... Transmission lines: Leakage surveys. Leakage surveys of a transmission line must be conducted at intervals not... transports gas in conformity with § 192.625 without an odor or odorant, leakage surveys using leak detector...

77 FR 38091 - NASA Advisory Council; Aeronautics Committee; Meeting.

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-26

... NATIONAL AERONAUTICS AND SPACE ADMINISTRATION [Notice: 12-047] NASA Advisory Council; Aeronautics... National Aeronautics and Space Administration announces a meeting of the Aeronautics Committee of the NASA..., July 24, 2012, 8 a.m. to 3 p.m. local time. ADDRESSES: NASA Goddard Space Flight Center (GSFC...

78 FR 41114 - NASA Advisory Council; Aeronautics Committee; Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-09

... NATIONAL AERONAUTICS AND SPACE ADMINISTRATION [Notice 13-075] NASA Advisory Council; Aeronautics... Aeronautics and Space Administration announces a meeting of the Aeronautics Committee of the NASA Advisory... planning. DATES: Tuesday, July 30, 2013, 9:00 a.m. to 5:00 p.m.; Local Time. ADDRESSES: NASA Headquarters...

75 FR 50782 - NASA Advisory Council; Aeronautics Committee; Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-17

... NATIONAL AERONAUTICS AND SPACE ADMINISTRATION [Notice (10-087)] NASA Advisory Council; Aeronautics... Aeronautics and Space Administration announces a meeting of the Aeronautics Committee of the NASA Advisory..., 2010, 8 a.m. to 12:30 p.m.; Local Time. ADDRESSES: NASA Ames Conference Center, Building 3, 500...

14 CFR 61.125 - Aeronautical knowledge.

Code of Federal Regulations, 2013 CFR

2013-01-01

... magnetic compass for pilotage and dead reckoning; (10) Use of air navigation facilities; (11) Aeronautical... aeronautical knowledge areas of paragraph (b) of this section that apply to the aircraft category and class... operation of aircraft; (6) Weight and balance computations; (7) Use of performance charts; (8) Significance...

Numerical Modeling of Methane Leakage from a Faulty Natural Gas Well into Fractured Tight Formations.

PubMed

Moortgat, Joachim; Schwartz, Franklin W; Darrah, Thomas H

2018-03-01

Horizontal drilling and hydraulic fracturing have enabled hydrocarbon recovery from unconventional reservoirs, but led to natural gas contamination of shallow groundwaters. We describe and apply numerical models of gas-phase migration associated with leaking natural gas wells. Three leakage scenarios are simulated: (1) high-pressure natural gas pulse released into a fractured aquifer; (2) continuous slow leakage into a tilted fractured formation; and (3) continuous slow leakage into an unfractured aquifer with fluvial channels, to facilitate a generalized evaluation of natural gas transport from faulty natural gas wells. High-pressure pulses of gas leakage into sparsely fractured media are needed to produce the extensive and rapid lateral spreading of free gas previously observed in field studies. Transport in fractures explains how methane can travel vastly different distances and directions laterally away from a leaking well, which leads to variable levels of methane contamination in nearby groundwater wells. Lower rates of methane leakage (≤1 Mcf/day) produce shorter length scales of gas transport than determined by the high-pressure scenario or field studies, unless aquifers have low vertical permeabilities (≤1 millidarcy) and fractures and bedding planes have sufficient tilt (∼10°) to allow a lateral buoyancy component. Similarly, in fractured rock aquifers or where permeability is controlled by channelized fluvial deposits, lateral flow is not sufficiently developed to explain fast-developing gas contamination (0-3 months) or large length scales (∼1 km) documented in field studies. Thus, current efforts to evaluate the frequency, mechanism, and impacts of natural gas leakage from faulty natural gas wells likely underestimate contributions from small-volume, low-pressure leakage events. © 2018, National Ground Water Association.

A laboratory validation study of the time-lapse oscillatory pumping test concept for leakage detection in geological repositories

NASA Astrophysics Data System (ADS)

Sun, A. Y.; Islam, A.; Lu, J.

2017-12-01

Time-lapse oscillatory pumping test (OPT) has been introduced recently as a pressure-based monitoring technique for detecting potential leakage in geologic repositories. By routinely conducting OPT at a number of pulsing frequencies, a site operator may identify the potential anomalies in the frequency domain, alleviating the ambiguity caused by reservoir noise and improving the signal-to-noise ratio. Building on previous theoretical and field studies, this work performed a series of laboratory experiments to validate the concept of time-lapse OPT using a custom made, stainless steel tank under relatively high pressures ( 120psi). The experimental configuration simulates a miniature geologic storage repository consisting of three layers (i.e., injection zone, caprock, and above-zone aquifer). Results show that leakage in the injection zone led to deviations in the power spectrum of observed pressure data, and the amplitude of which also increases with decreasing pulsing frequencies. The experimental results were further analyzed by developing a 3D flow model, using which the model parameters were estimated through frequency domain inversion.

47 CFR 87.241 - Frequencies.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Aeronautical Multicom Stations § 87.241 Frequencies. (a) 121.500 MHz: emergency and distress only; (b) 122.850... coordinating foresty management and fire suppression, fish and game management and protection, and...

Aeronautical Engineering: A Continuing Bibliography. Supplement 421

NASA Technical Reports Server (NTRS)

2000-01-01

This supplemental issue of Aeronautical Engineering, A Continuing Bibliography with Indexes (NASA/SP#2000-7037) lists reports, articles, and other documents recently announced in the NASA STI Database. The coverage includes documents on the engineering and theoretical aspects of design, construction, evaluation, testing, operation, and performance of aircraft (including aircraft engines) and associated components, equipment, and systems. It also includes research and development in aerodynamics, aeronautics, and ground support equipment for aeronautical vehicles.

47 CFR 76.612 - Cable television frequency separation standards.

Code of Federal Regulations, 2010 CFR

2010-10-01

... frequency separation standards. All cable television systems which operate in the frequency bands 108-137... kHz bandwidth in any 160 microsecond period must operate at frequencies offset from certain frequencies which may be used by aeronautical radio services operated by Commission licensees or by the United...

47 CFR 76.1803 - Signal leakage monitoring.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 4 2010-10-01 2010-10-01 false Signal leakage monitoring. 76.1803 Section 76... MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Reports and Filings § 76.1803 Signal leakage monitoring. MVPDs... of the method by which compliance with basic signal leakage criteria is achieved and the method of...

47 CFR 76.1803 - Signal leakage monitoring.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 4 2011-10-01 2011-10-01 false Signal leakage monitoring. 76.1803 Section 76... MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Reports and Filings § 76.1803 Signal leakage monitoring. MVPDs... of the method by which compliance with basic signal leakage criteria is achieved and the method of...

47 CFR 76.1803 - Signal leakage monitoring.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 4 2013-10-01 2013-10-01 false Signal leakage monitoring. 76.1803 Section 76... MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Reports and Filings § 76.1803 Signal leakage monitoring. MVPDs... of the method by which compliance with basic signal leakage criteria is achieved and the method of...

47 CFR 76.1803 - Signal leakage monitoring.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 4 2014-10-01 2014-10-01 false Signal leakage monitoring. 76.1803 Section 76... MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Reports and Filings § 76.1803 Signal leakage monitoring. MVPDs... of the method by which compliance with basic signal leakage criteria is achieved and the method of...

47 CFR 76.1803 - Signal leakage monitoring.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 4 2012-10-01 2012-10-01 false Signal leakage monitoring. 76.1803 Section 76... MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Reports and Filings § 76.1803 Signal leakage monitoring. MVPDs... of the method by which compliance with basic signal leakage criteria is achieved and the method of...

Advancing Aeronautics: A Decision Framework for Selecting Research Agendas

NASA Technical Reports Server (NTRS)

Anton, Philip S.; Ecola, Liisa; Kallimani, James G.; Light, Thomas; Ohlandt, Chad J. R.; Osburg, Jan; Raman, Raj; Grammich, Clifford A.

2011-01-01

Publicly funded research has long played a role in the development of aeronautics, ranging from foundational research on airfoils to development of the air-traffic control system. Yet more than a century after the research and development of successful controlled, sustained, heavier-than-air flight vehicles, there are questions over the future of aeronautics research. The field of aeronautics is relatively mature, technological developments within it have become more evolutionary, and funding decisions are sometimes motivated by the continued pursuit of these evolutionary research tracks rather than by larger factors. These developments raise questions over whether public funding of aeronautics research continues to be appropriate or necessary and at what levels. Tightened federal budgets and increasing calls to address other public demands make these questions sharper still. To help it address the questions of appropriate directions for publicly funded aeronautics research, the National Aeronautics and Space Administration's (NASA's) Aeronautics Research Mission Directorate (ARMD) asked the RAND Corporation to assess the elements required to develop a strategic view of aeronautics research opportunities; identify candidate aeronautic grand challenges, paradigms, and concepts; outline a framework for evaluating them; and exercise the framework as an example of how to use it. Accordingly, this research seeks to address these questions: What aeronautics research should be supported by the U.S. government? What compelling and desirable benefits drive government-supported research? How should the government--especially NASA--make decisions about which research to support? Advancing aeronautics involves broad policy and decisionmaking challenges. Decisions involve tradeoffs among competing perspectives, uncertainties, and informed judgment.

Experimental evaluation of clinical colon anastomotic leakage.

PubMed

Pommergaard, Hans-Christian

2014-03-01

Colorectal anastomotic leakage remains a frequent and serious complication in gastrointestinal surgery. Patient and procedure related risk factors for anastomotic leakage have been identified. However, the responsible pathophysiological mechanisms are still unknown. Among these, ischemia and insufficient surgical technique have been suggested to play a central role. Animal models are valuable means to evaluate pathophysiological mechanisms and may be used to test preventive measures aiming at reducing the risk of anastomotic leakage, such as external anastomotic coating. The aim of this thesis was to: Clarify the best suited animal to model clinical anastomotic leakage in humans; Create animal models mimicking anastomotic leakage in humans induced by insufficient surgical technique and tissue ischemia; Determine the best suited coating materials to prevent anastomotic leakage. This study is a systematic review using the databases MEDLINE and Rex. MEDLINE was searched up to October 2010 to identify studies on experimental animal models of clinical colon anastomotic leakage. From the Rex database, textbooks on surgical aspects as well as gastrointestinal physiology and anatomy of experimental animals were identified. The results indicated that the mouse and the pig are the best suited animals to evaluate clinical anastomotic leakage. However, the pig model is less validated and more costly to use compared with the mouse. Most frequently, rats are used as models. However, extreme interventions are needed to create clinical leakage in these animals. The knowledge from this study formed the basis for selecting the animal species most suited for the models in the next studies. STUDY 2: In this experimental study, technically insufficient colonic anastomoses were performed in 110 C57BL/6 mice. The number of sutures in the intervention group was reduced to produce a suitable leakage rate. Moreover, the analgesia and suture material were changed in order to optimize the

Differences in Ostomy Pouch Seal Leakage Occurrences Between North American and European Residents.

PubMed

Fellows, Jane; Forest Lalande, Louise; Martins, Lina; Steen, Anne; Størling, Zenia M

The purpose of this study was to compare experiences and concerns about pouch seal leakage between persons with ostomies residing in North America (Canada and the United States) and Europe (United Kingdom, Netherlands, Sweden, Germany, Belgium, France, and Italy). Differences in reported pouch wear time and accessories used between the 2 groups were also examined. Secondary analysis of data from a cross-sectional study (Ostomy Life Study). Responses from persons residing in European countries (n = 1939) were compared with responses of 1387 individuals residing in North American countries. Persons with an ostomy completed a questionnaire that focused on 4 topics related to the daily use of an ostomy pouching system (pouch seal leakage, ballooning, appearance of pouching system such as color and size of the pouch and whether it is discrete under clothing, and coupling failure of 2-piece pouching systems). Pouch seal leakage was defined as stomal effluent seeping between the skin and the wafer of the ostomy pouching system. Statistical analysis was performed using a proportional odds model including various variable effects. Special attention was given to frequency of pouch seal leakage occurrences. All tests were 2-sided; P values ≤.05 were deemed statistically significant. Participants living in the North American countries indicated they were more likely to experience leakage from the ostomy (odds ratio = 2.610, 95% CI 2.187-3.115; P < .0001). Findings also indicated they were more likely to worry about pouch seal leakage than those in the European countries' data set (odds ratio = 2.722, 95% CI 2.283-3.246; P < .0001). Participants residing in the North American countries had significantly longer wear times than those participants in the European countries (P < .0001, χ test). The use of accessories was associated with a longer pouching system wear time. Study results suggest that participants from the North American countries indicated significantly more

40 CFR 265.302 - Action leakage rate.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 25 2010-07-01 2010-07-01 false Action leakage rate. 265.302 Section... FACILITIES Landfills § 265.302 Action leakage rate. (a) The owner or operator of landfill units subject to § 265.301(a) must submit a proposed action leakage rate to the Regional Administrator when submitting...

40 CFR 265.222 - Action leakage rate.

Code of Federal Regulations, 2010 CFR

2010-07-01

... to § 265.221(a). The action leakage rate is the maximum design flow rate that the leak detection... 40 Protection of Environment 25 2010-07-01 2010-07-01 false Action leakage rate. 265.222 Section... FACILITIES Surface Impoundments § 265.222 Action leakage rate. (a) The owner or operator of surface...

14 CFR 61.97 - Aeronautical knowledge.

Code of Federal Regulations, 2013 CFR

2013-01-01

... knowledge areas of paragraph (b) of this section that apply to the aircraft category and class rating sought... “Aeronautical Information Manual” and FAA advisory circulars; (4) Use of aeronautical charts for VFR navigation using pilotage with the aid of a magnetic compass; (5) Recognition of critical weather situations from...

University/government/industry relations in aeronautics

NASA Technical Reports Server (NTRS)

Schairer, G. S.

1975-01-01

Methods for improving the relationships between universities, the aircraft industry, and the Government are proposed. The author submits nine specific recommendations aimed at more effective aeronautical engineering education and employment of graduate engineers. The need for improved communication between the organizations which influence the advancement of aeronautical sciences is stressed.

FELERION: a new approach for leakage power reduction

NASA Astrophysics Data System (ADS)

R, Anjana; Somkuwar, Ajay

2014-12-01

The circuit proposed in this paper simultaneously reduces the sub threshold leakage power and saves the state of art aspect of the logic circuits. Sleep transistors and PMOS-only logic are used to further reduce the leakage power. Sleep transistors are used as the keepers to reduce the sub threshold leakage current providing the low resistance path to the output. PMOS-only logic is used between the pull up and pull down devices to mitigate the leakage power further. Our proposed fast efficient leakage reduction circuit not only reduces the leakage current but also reduces the power dissipation. Power and delay are analyzed at the 32 nm BSIM4 model for a chain of four inverters, NAND, NOR and ISCAS-85 c17 benchmark circuits using DSCH3 and the Microwind tool. The simulation results reveal that our proposed approach mitigates leakage power by 90%-94% as compared to the conventional approach.

40 CFR 265.255 - Action leakage rates.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 25 2010-07-01 2010-07-01 false Action leakage rates. 265.255 Section... FACILITIES Waste Piles § 265.255 Action leakage rates. (a) The owner or operator of waste pile units subject to § 265.254 must submit a proposed action leakage rate to the Regional Administrator when submitting...

A laboratory validation study of the time-lapse oscillatory pumping test for leakage detection in geological repositories

NASA Astrophysics Data System (ADS)

Sun, Alexander Y.; Lu, Jiemin; Islam, Akand

2017-05-01

Geologic repositories are extensively used for disposing byproducts in mineral and energy industries. The safety and reliability of these repositories are a primary concern to environmental regulators and the public. Time-lapse oscillatory pumping test (OPT) has been introduced recently as a pressure-based technique for detecting potential leakage in geologic repositories. By routinely conducting OPT at a number of pulsing frequencies, an operator may identify the potential repository anomalies in the frequency domain, alleviating the ambiguity caused by reservoir noise and improving the signal-to-noise ratio. Building on previous theoretical and field studies, this work performed a series of laboratory experiments to validate the concept of time-lapse OPT using a custom made, stainless steel tank under relatively high pressures. The experimental configuration simulates a miniature geologic storage repository consisting of three layers (i.e., injection zone, caprock, and above-zone aquifer). Results show that leakage in the injection zone led to deviations in the power spectrum of observed pressure data, and the amplitude of which also increases with decreasing pulsing frequencies. The experimental results are further analyzed by developing a 3D flow model, using which the model parameters are estimated through frequency domain inversion.

Application of Mobile-ip to Space and Aeronautical Networks

NASA Technical Reports Server (NTRS)

Leung, Kent; Shell, Dan; Ivancic, William D.; Stewart, David H.; Bell, Terry L.; Kachmar, Brian A.

2001-01-01

The National Aeronautics and Space Administration (NASA) is interested in applying mobile Internet protocol (mobile-ip) technologies to its space and aeronautics programs. In particular, mobile-ip will play a major role in the Advanced Aeronautic Transportation Technology (AAT-F), the Weather Information Communication (WINCOMM), and the Small Aircraft Transportation System (SATS) aeronautics programs. This paper describes mobile-ip and mobile routers--in particular, the features, capabilities, and initial performance of the mobile router are presented. The application of mobile-router technology to NASA's space and aeronautics programs is also discussed.

Comparing Natural Gas Leakage Detection Technologies Using an Open-Source "Virtual Gas Field" Simulator.

PubMed

Kemp, Chandler E; Ravikumar, Arvind P; Brandt, Adam R

2016-04-19

We present a tool for modeling the performance of methane leak detection and repair programs that can be used to evaluate the effectiveness of detection technologies and proposed mitigation policies. The tool uses a two-state Markov model to simulate the evolution of methane leakage from an artificial natural gas field. Leaks are created stochastically, drawing from the current understanding of the frequency and size distributions at production facilities. Various leak detection and repair programs can be simulated to determine the rate at which each would identify and repair leaks. Integrating the methane leakage over time enables a meaningful comparison between technologies, using both economic and environmental metrics. We simulate four existing or proposed detection technologies: flame ionization detection, manual infrared camera, automated infrared drone, and distributed detectors. Comparing these four technologies, we found that over 80% of simulated leakage could be mitigated with a positive net present value, although the maximum benefit is realized by selectively targeting larger leaks. Our results show that low-cost leak detection programs can rely on high-cost technology, as long as it is applied in a way that allows for rapid detection of large leaks. Any strategy to reduce leakage should require a careful consideration of the differences between low-cost technologies and low-cost programs.

Aeronautical Mobile Airport Communications System (AeroMACS)

NASA Technical Reports Server (NTRS)

Budinger, James M.; Hall, Edward

2011-01-01

To help increase the capacity and efficiency of the nation s airports, a secure wideband wireless communications system is proposed for use on the airport surface. This paper provides an overview of the research and development process for the Aeronautical Mobile Airport Communications System (AeroMACS). AeroMACS is based on a specific commercial profile of the Institute of Electrical and Electronics Engineers (IEEE) 802.16 standard known as Wireless Worldwide Interoperability for Microwave Access or WiMAX (WiMax Forum). The paper includes background on the need for global interoperability in air/ground data communications, describes potential AeroMACS applications, addresses allocated frequency spectrum constraints, summarizes the international standardization process, and provides findings and recommendations from the world s first AeroMACS prototype implemented in Cleveland, Ohio, USA.

Geochemical monitoring for detection of CO_{2} leakage from subsea storage sites

NASA Astrophysics Data System (ADS)

García-Ibáñez, Maribel I.; Omar, Abdirahman M.; Johannessen, Truls

2017-04-01

Carbon Capture and Storage (CCS) in subsea geological formations is a promising large-scale technology for mitigating the increases of carbon dioxide (CO2) in the atmosphere. However, detection and quantification of potential leakage of the stored CO2 remains as one of the main challenges of this technology. Geochemical monitoring of the water column is specially demanding because the leakage CO2 once in the seawater may be rapidly dispersed by dissolution, dilution and currents. In situ sensors capture CO2 leakage signal if they are deployed very close to the leakage point. For regions with vigorous mixing and/or deep water column, and for areas far away from the leakage point, a highly sensitive carbon tracer (Cseep tracer) was developed based on the back-calculation techniques used to estimate anthropogenic CO2 in the water column. Originally, the Cseep tracer was computed using accurate discrete measurements of total dissolved inorganic carbon (DIC) and total alkalinity (AT) in the Norwegian Sea to isolate the effect of natural submarine vents in the water column. In this work we assess the effect of measurement variables on the performance of the method by computing the Cseep tracer twice: first using DIC and AT, and second using partial pressure of CO2 (pCO2) and pH. The assessment was performed through the calculation of the signal to noise ratios (STNR). We found that the use of the Cseep tracer increases the STNR ten times compared to the raw measurement data, regardless of the variables used. Thus, while traditionally the pH-pCO2 pair generates the greatest uncertainties in the oceanic CO2 system, it seems that the Cseep technique is insensitive to that issue. On the contrary, the use of the pCO2-pH pair has the highest CO2 leakage detection and localization potential due to the fact that both pCO2 and pH can currently be measured at high frequency and in an autonomous mode.

49 CFR 229.59 - Leakage.

Code of Federal Regulations, 2012 CFR

2012-10-01

...) Leakage from the main air reservoir and related piping may not exceed an average of 3 pounds per square.... (b) Brake pipe leakage may not exceed 5 pounds per square inch per minute. (c) With a full service... pneumatically operated controls may not exceed an average of 3 pounds per square inch per minute for 3 minutes...

49 CFR 229.59 - Leakage.

Code of Federal Regulations, 2014 CFR

2014-10-01

...) Leakage from the main air reservoir and related piping may not exceed an average of 3 pounds per square.... (b) Brake pipe leakage may not exceed 5 pounds per square inch per minute. (c) With a full service... pneumatically operated controls may not exceed an average of 3 pounds per square inch per minute for 3 minutes...

49 CFR 229.59 - Leakage.

Code of Federal Regulations, 2013 CFR

2013-10-01

...) Leakage from the main air reservoir and related piping may not exceed an average of 3 pounds per square.... (b) Brake pipe leakage may not exceed 5 pounds per square inch per minute. (c) With a full service... pneumatically operated controls may not exceed an average of 3 pounds per square inch per minute for 3 minutes...

49 CFR 229.59 - Leakage.

Code of Federal Regulations, 2010 CFR

2010-10-01

...) Leakage from the main air reservoir and related piping may not exceed an average of 3 pounds per square.... (b) Brake pipe leakage may not exceed 5 pounds per square inch per minute. (c) With a full service... pneumatically operated controls may not exceed an average of 3 pounds per square inch per minute for 3 minutes...

49 CFR 229.59 - Leakage.

Code of Federal Regulations, 2011 CFR

2011-10-01

...) Leakage from the main air reservoir and related piping may not exceed an average of 3 pounds per square.... (b) Brake pipe leakage may not exceed 5 pounds per square inch per minute. (c) With a full service... pneumatically operated controls may not exceed an average of 3 pounds per square inch per minute for 3 minutes...

Human Factors in Aeronautics at NASA

NASA Technical Reports Server (NTRS)

Mogford, Richard

2016-01-01

This is a briefing to a regularly meeting DoD group called the Human Systems Community of Interest: Mission Effectiveness. I was asked to address human factors in aeronautics at NASA. (Exploration (space) human factors has apparently already been covered.) The briefing describes human factors organizations at NASA Ames and Langley. It then summarizes some aeronautics tasks that involve the application of human factors in the development of specific tools and capabilities. The tasks covered include aircrew checklists, dispatch operations, Playbook, Dynamic Weather Routes, Traffic Aware Strategic Aircrew Requests, and Airplane State Awareness and Prediction Technologies. I mention that most of our aeronautics work involves human factors as embedded in development tasks rather than basic research.

Astronautics and Aeronautics, 1986-1990: A Chronology

NASA Technical Reports Server (NTRS)

Gawdiak, Ihor Y.; Miro, Ramon J.; Stueland, Sam

1997-01-01

This chronology of events in aeronautics, aviation, space science, and space exploration was prepared by the Federal Research Division of the LibrarY of Congress for the History Division of the National Aeronautics and Space Administration (NASA). It covers the years 1996-1990 and continues the series of annual chronologies published by NASA. The present volume returns to the format used in the Astronautics and Aeronautics, 1979-1984: A Chronology volume. It also integrates in a single table the information presented in two or three previous publications.

Astronautics and Aeronautics, 1991-1995: A Chronology

NASA Technical Reports Server (NTRS)

Gawdiak, Ihor Y. (Compiler); Shetland, Charles (Compiler)

2000-01-01

This chronology of events in aeronautics, aviation, space science, and space exploration was prepared by the Federal Research Division of the Library of Congress and RSIS for the History Division of the National Aeronautics and Space Administration (NASA). It covers the years 1991-1995 and continues the series of annual chronologies published by NASA. The present volume uses the format of the previous edition of this series, Astronautics and Aeronautics, 1986-1990: A Chronology. It also integrates, in the appendices, information presented in previous publication

Canadian aeronautical mobile data trials

NASA Technical Reports Server (NTRS)

Pedersen, Allister; Pearson, Andrea

1993-01-01

This paper describes a series of aeronautical mobile data trials conducted on small aircraft (helicopters and fixed wing) utilizing a low-speed store-and-forward mobile data service. The paper outlines the user requirements for aeronautical mobile satellite communications. 'Flight following' and improved wide-area dispatch communications were identified as high priority requirements. A 'proof-of-concept' trial in a Cessna Skymaster aircraft is described. This trial identified certain development work as essential to the introduction of commercial service including antenna development, power supply modifications and doppler software modifications. Other improvements were also proposed. The initial aeronautical mobile data service available for pre-operational (Beta) trials is outlined. Pre-operational field trials commenced in October 1992 and consisted of installations on a Gralen Communications Inc. Cessna 177 and an Aerospatiale Astar 350 series light single engine helicopter. The paper concludes with a discussion of desirable near term mobile data service developments, commercial benefits, current safety benefits and potential future applications for improved safety.

Aeronautical record : no. 1 (to June, 1923)

NASA Technical Reports Server (NTRS)

1923-01-01

"...considerations have prompted us to pay special attention to the development of aeronautical industries and aerial navigation as a commercial enterprise and to publish an analytical review of events in the aeronautical world and of the attendant problems."

Aeronautical Engineering: A Continuing Bibliography. Supplment 385

NASA Technical Reports Server (NTRS)

1998-01-01

This supplemental issue of Aeronautical Engineering, A Continuing Bibliography with Indexes (NASA/SP-1998-7037) lists reports, articles, and other documents recently announced in the NASA STI Database. The coverage includes documents on the engineering and theoretical aspects of design, construction, evaluation, testing, operation, and performance of aircraft (including aircraft engines) and associated components, equipment, and systems. It also includes research and development in aerodynamics, aeronautics, and ground support equipment for aeronautical vehicles. Each entry in the publication consists of a standard bibliographic citation accompanied, in most cases, by an abstract.

Trending of Overboard Leakage of ISS Cabin Atmosphere

NASA Technical Reports Server (NTRS)

Schaezler, Ryan N.; Cook, Anthony J.; Leonard, Daniel J.; Ghariani, Ahmed

2011-01-01

The International Space Station (ISS) overboard leakage of cabin atmosphere is continually tracked to identify new or aggravated leaks and to provide information for planning of nitrogen supply to the ISS. The overboard leakage is difficult to trend with various atmosphere constituents being added and removed. Changes to nitrogen partial pressure is the nominal means of trending the overboard leakage. This paper summarizes the method of the overboard leakage trending and presents findings from the trending.

A TMS320-based modem for the aeronautical-satellite core data service

NASA Astrophysics Data System (ADS)

Moher, Michael L.; Lodge, John H.

The International Civil Aviation Organization (ICAO) Future Air Navigation Systems (FANS) committee, the Airlines Electronics Engineering Committee (AEEC), and Inmarsat have been developing standards for an aeronautical satellite communications service. These standards encompass a satellite communications system architecture to provide comprehensive aeronautical communications services. Incorporated into the architecture is a core service capability, providing only low rate data communications, which all service providers and all aircraft earth terminals are required to support. In this paper an implementation of the physical layer of this standard for the low data rate core service is described. This is a completely digital modem (up to a low intermediate frequency). The implementation uses a single TMS320C25 chip for the transmit baseband functions of scrambling, encoding, interleaving, block formatting and modulation. The receiver baseband unit uses a dual processor configuration to implement the functions of demodulation, synchronization, de-interleaving, decoding and de-scrambling. The hardware requirements, the software structure and the algorithms of this implementation are described.

49 CFR 236.735 - Current, leakage.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Current, leakage. 236.735 Section 236.735 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Current, leakage. A stray electric current of relatively small value which flows through or across the...

49 CFR 236.735 - Current, leakage.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Current, leakage. A stray electric current of relatively small value which flows through or across the... 49 Transportation 4 2011-10-01 2011-10-01 false Current, leakage. 236.735 Section 236.735 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION...

49 CFR 236.735 - Current, leakage.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Current, leakage. A stray electric current of relatively small value which flows through or across the... 49 Transportation 4 2014-10-01 2014-10-01 false Current, leakage. 236.735 Section 236.735 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION...

49 CFR 236.735 - Current, leakage.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Current, leakage. A stray electric current of relatively small value which flows through or across the... 49 Transportation 4 2013-10-01 2013-10-01 false Current, leakage. 236.735 Section 236.735 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION...

49 CFR 236.735 - Current, leakage.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Current, leakage. A stray electric current of relatively small value which flows through or across the... 49 Transportation 4 2012-10-01 2012-10-01 false Current, leakage. 236.735 Section 236.735 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION...

Blood-brain barrier leakage after status epilepticus in rapamycin-treated rats I: Magnetic resonance imaging.

PubMed

van Vliet, Erwin A; Otte, Willem M; Wadman, Wytse J; Aronica, Eleonora; Kooij, Gijs; de Vries, Helga E; Dijkhuizen, Rick M; Gorter, Jan A

2016-01-01

The mammalian target of rapamycin (mTOR) pathway has received increasing attention as a potential antiepileptogenic target. Treatment with the mTOR inhibitor rapamycin after status epilepticus reduces the development of epilepsy in a rat model. To study whether rapamycin mediates this effect via restoration of blood-brain barrier (BBB) dysfunction, contrast-enhanced magnetic resonance imaging (CE-MRI) was used to determine BBB permeability throughout epileptogenesis. Imaging was repeatedly performed until 6 weeks after kainic acid-induced status epilepticus in rapamycin (6 mg/kg for 6 weeks starting 4 h after SE) and vehicle-treated rats, using gadobutrol as contrast agent. Seizures were detected using video monitoring in the week following the last imaging session. Gadobutrol leakage was widespread and extensive in both rapamycin and vehicle-treated epileptic rats during the acute phase, with the piriform cortex and amygdala as the most affected regions. Gadobutrol leakage was higher in rapamycin-treated rats 4 and 8 days after status epilepticus compared to vehicle-treated rats. However, during the chronic epileptic phase, gadobutrol leakage was lower in rapamycin-treated epileptic rats along with a decreased seizure frequency. This was confirmed by local fluorescein staining in the brains of the same rats. Total brain volume was reduced by this rapamycin treatment regimen. The initial slow recovery of BBB function in rapamycin-treated epileptic rats indicates that rapamycin does not reduce seizure activity by a gradual recovery of BBB integrity. The reduced BBB leakage during the chronic phase, however, could contribute to the decreased seizure frequency in post-status epilepticus rats treated with rapamycin. Furthermore, the data show that CE-MRI (using step-down infusion with gadobutrol) can be used as biomarker for monitoring the effect of drug therapy in rats. Wiley Periodicals, Inc. © 2015 International League Against Epilepsy.

Aeronautical facilities assessment

NASA Technical Reports Server (NTRS)

Penaranda, F. E. (Compiler)

1985-01-01

A survey of the free world's aeronautical facilities was undertaken and an evaluation made on where the relative strengths and weaknesses exist. Special emphasis is given to NASA's own capabilities and needs. The types of facilities surveyed are: Wind Tunnels; Airbreathing Propulsion Facilities; and Flight Simulators

Gas pipeline leakage detection based on PZT sensors

NASA Astrophysics Data System (ADS)

Zhu, Junxiao; Ren, Liang; Ho, Siu-Chun; Jia, Ziguang; Song, Gangbing

2017-02-01

In this paper, an innovative method for rapid detection and location determination of pipeline leakage utilizing lead zirconate titanate (PZT) sensors is proposed. The negative pressure wave (NPW) is a stress wave generated by leakage in the pipeline, and propagates along the pipeline from the leakage point to both ends. Thus the NPW is associated with hoop strain variation along the pipe wall. PZT sensors mounted on the pipeline were used to measure the strain variation and allowed accurate (within 2% error) and repeatable location (within 4% variance) of five manually controlled leakage points. Experimental results have verified the effectiveness and the location accuracy for leakage in a 55 meter long model pipeline.

Nonlinear Acoustic and Ultrasonic NDT of Aeronautical Components

NASA Astrophysics Data System (ADS)

Van Den Abeele, Koen; Katkowski, Tomasz; Mattei, Christophe

2006-05-01

In response to the demand for innovative microdamage inspection systems, with high sensitivity and undoubted accuracy, we are currently investigating the use and robustness of several acoustic and ultrasonic NDT techniques based on Nonlinear Elastic Wave Spectroscopy (NEWS) for the characterization of microdamage in aeronautical components. In this report, we illustrate the results of an amplitude dependent analysis of the resonance behaviour, both in time (signal reverberation) and in frequency (sweep) domain. The technique is applied to intact and damaged samples of Carbon Fiber Reinforced Plastics (CFRP) composites after thermal loading or mechanical fatigue. The method shows a considerable gain in sensitivity and an incontestable interpretation of the results for nonlinear signatures in comparison with the linear characteristics. For highly fatigued samples, slow dynamical effects are observed.

Polarization leakage in epoch of reionization windows - III. Wide-field effects of narrow-field arrays

NASA Astrophysics Data System (ADS)

Asad, K. M. B.; Koopmans, L. V. E.; Jelić, V.; de Bruyn, A. G.; Pandey, V. N.; Gehlot, B. K.

2018-05-01

Leakage of polarized Galactic diffuse emission into total intensity can potentially mimic the 21-cm signal coming from the epoch of reionization (EoR), as both of them might have fluctuating spectral structure. Although we are sensitive to the EoR signal only in small fields of view, chromatic side-lobes from further away can contaminate the inner region. Here, we explore the effects of leakage into the `EoR window' of the cylindrically averaged power spectra (PS) within wide fields of view using both observation and simulation of the 3C196 and North Celestial Pole (NCP) fields, two observing fields of the LOFAR-EoR project. We present the polarization PS of two one-night observations of the two fields and find that the NCP field has higher fluctuations along frequency, and consequently exhibits more power at high-k∥ that could potentially leak to Stokes I. Subsequently, we simulate LOFAR observations of Galactic diffuse polarized emission based on a model to assess what fraction of polarized power leaks into Stokes I because of the primary beam. We find that the rms fractional leakage over the instrumental k-space is 0.35 {per cent} in the 3C196 field and 0.27 {per cent} in the NCP field, and it does not change significantly within the diameters of 15°, 9°, and 4°. Based on the observed PS and simulated fractional leakage, we show that a similar level of leakage into Stokes I is expected in the 3C196 and NCP fields, and the leakage can be considered to be a bias in the PS.

Compressibility effects on rotor forces in the leakage path between a shrouded pump impeller and its housing

NASA Technical Reports Server (NTRS)

Cao, Nhai The

1993-01-01

A modified approach to Childs' previous work on fluid-structure interaction forces in the leakage path between an impeller shroud and its housing is presented in this paper. Three governing equations consisting of continuity, path-momentum, and circumferential-momentum equations were developed to describe the leakage path inside a pump impeller. Radial displacement perturbations were used to solve for radial and circumferential force coefficients. In addition, impeller-discharge pressure disturbances were used to obtain pressure oscillation responses due to precessing impeller pressure wave pattern. Childs' model was modified from an incompressible model to a compressible barotropic-fluid model (the density of the working fluid is a function of the pressure and a constant temperature only). Results obtained from this model yielded interaction forces for radial and circumferential force coefficients. Radial and circumferential forces define reaction forces within the impeller leakage path. An acoustic model for the same leakage path was also developed. The convective, Coriolis, and centrifugal acceleration terms are removed from the compressible model to obtain the acoustics model. A solution due to impeller discharge pressure disturbances model was also developed for the compressible and acoustics models. The results from these modifications are used to determine what effects additional perturbation terms in the compressible model have on the acoustic model. The results show that the additional fluid mechanics terms in the compressible model cause resonances (peaks) in the force coefficient response curves. However, these peaks only occurred at high values of inlet circumferential velocity ratios greater than 0.7. The peak pressure oscillation was shown to occur at the wearing ring seal. Introduction of impeller discharge disturbances with n = 11 diametral nodes showed that maximum peak pressure oscillations occurred at nondimensional precession frequencies of f

Aeronautical engineering: A continuing bibliography with indexes (supplement 294)

NASA Technical Reports Server (NTRS)

1993-01-01

This issue of Aeronautical Engineering - A Continuing Bibliography with Indexes lists 590 reports, journal articles, and other documents recently announced in the NASA STI Database. The coverage includes documents on the engineering and theoretical aspect of design, construction, evaluation, testing, operation, and performance of aircraft (including aircraft engines) and associated components, equipment, and systems. It also includes research and development in aerodynamics, aeronautics, and ground support equipment for aeronautical vehicles. The bibliographic series is compiled through the cooperative efforts of the American Institute of Aeronautics and Astronautics (AIAA) and the National Aeronautics and Space Administration (NASA). Seven indexes are included: subject, personal author, corporate source, foreign technology, contract number, report number, and accession number.

Robust Timing Synchronization in Aeronautical Mobile Communication Systems

NASA Technical Reports Server (NTRS)

Xiong, Fu-Qin; Pinchak, Stanley

2004-01-01

This work details a study of robust synchronization schemes suitable for satellite to mobile aeronautical applications. A new scheme, the Modified Sliding Window Synchronizer (MSWS), is devised and compared with existing schemes, including the traditional Early-Late Gate Synchronizer (ELGS), the Gardner Zero-Crossing Detector (GZCD), and the Sliding Window Synchronizer (SWS). Performance of the synchronization schemes is evaluated by a set of metrics that indicate performance in digital communications systems. The metrics are convergence time, mean square phase error (or root mean-square phase error), lowest SNR for locking, initial frequency offset performance, midstream frequency offset performance, and system complexity. The performance of the synchronizers is evaluated by means of Matlab simulation models. A simulation platform is devised to model the satellite to mobile aeronautical channel, consisting of a Quadrature Phase Shift Keying modulator, an additive white Gaussian noise channel, and a demodulator front end. Simulation results show that the MSWS provides the most robust performance at the cost of system complexity. The GZCD provides a good tradeoff between robustness and system complexity for communication systems that require high symbol rates or low overall system costs. The ELGS has a high system complexity despite its average performance. Overall, the SWS, originally designed for multi-carrier systems, performs very poorly in single-carrier communications systems. Table 5.1 in Section 5 provides a ranking of each of the synchronization schemes in terms of the metrics set forth in Section 4.1. Details of comparison are given in Section 5. Based on the results presented in Table 5, it is safe to say that the most robust synchronization scheme examined in this work is the high-sample-rate Modified Sliding Window Synchronizer. A close second is its low-sample-rate cousin. The tradeoff between complexity and lowest mean-square phase error determines

Aeronautical Engineering: A continuing bibliography, 1982 cumulative index

NASA Technical Reports Server (NTRS)

1983-01-01

This bibliography is a cumulative index to the abstracts contained in NASA SP-7037 (145) through NASA SP-7037 (156) of Aeronautical Engineering: A Continuing Bibliography. NASA SP-7037 and its supplements have been compiled through the cooperative efforts of the American Institute of Aeronautics and Astronautics (AIAA) and the National Aeronautics and Space Administration (NASA). This cumulative index includes subject, personal author, corporate source, contract, and report number indexes.

Economic analysis of aeronautical research and technology

NASA Technical Reports Server (NTRS)

Gellman, A. J.

1982-01-01

The appropriateness of government intervention in the civilian market for aeronautics research and technology (R&T) is examined. The economic rationale for government intervention is examined. The conclusion is that the institutional role played by NASA in civilian aeronautics R&T markets is economically justified.

Zero leakage separable and semipermanent ducting joints

NASA Technical Reports Server (NTRS)

Mischel, H. T.

1973-01-01

A study program has been conducted to explore new methods of achieving zero leakage, separable and semipermanent, ducting joints for space flight vehicles. The study consisted of a search of literature of existing zero leakage methods, the generation of concepts of new methods of achieving the desired zero leakage criteria and the development of detailed analysis and design of a selected concept. Other techniques of leak detection were explored with a view toward improving this area.

Aeronautics and Space Report of the President: 1975 Activities.

ERIC Educational Resources Information Center

National Aeronautics and Space Administration, Washington, DC.

This report, submitted to the Congress by President Ford in accordance with the National Aeronautics and Space Act of 1958, summarizes the United States' space and aeronautics activities for the year 1975. Detailed summaries of the activities of the following governmental departments or agencies are provided: National Aeronautics and Space…

14 CFR 61.159 - Aeronautical experience: Airplane category rating.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Aeronautical experience: Airplane category... Transport Pilots § 61.159 Aeronautical experience: Airplane category rating. (a) Except as provided in... certificate with an airplane category and class rating must have at least 1,500 hours of total time as a pilot...

14 CFR 61.159 - Aeronautical experience: Airplane category rating.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Aeronautical experience: Airplane category... Transport Pilots § 61.159 Aeronautical experience: Airplane category rating. (a) Except as provided in... certificate with an airplane category and class rating must have at least 1,500 hours of total time as a pilot...

14 CFR 61.159 - Aeronautical experience: Airplane category rating.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Aeronautical experience: Airplane category... Transport Pilots § 61.159 Aeronautical experience: Airplane category rating. (a) Except as provided in... certificate with an airplane category and class rating must have at least 1,500 hours of total time as a pilot...

14 CFR 61.159 - Aeronautical experience: Airplane category rating.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false Aeronautical experience: Airplane category... Transport Pilots § 61.159 Aeronautical experience: Airplane category rating. (a) Except as provided in... certificate with an airplane category and class rating must have at least 1,500 hours of total time as a pilot...

14 CFR 61.159 - Aeronautical experience: Airplane category rating.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false Aeronautical experience: Airplane category... Transport Pilots § 61.159 Aeronautical experience: Airplane category rating. (a) Except as provided in... certificate with an airplane category and class rating must have at least 1,500 hours of total time as a pilot...

14 CFR 63.37 - Aeronautical experience requirements.

Code of Federal Regulations, 2013 CFR

2013-01-01

... flight training in the duties of a flight engineer. (3) A degree in aeronautical, electrical, or... (CONTINUED) AIRMEN CERTIFICATION: FLIGHT CREWMEMBERS OTHER THAN PILOTS Flight Engineers § 63.37 Aeronautical...— (1) On which a flight engineer is required by this chapter; or (2) That has at least three engines...

14 CFR 63.37 - Aeronautical experience requirements.

Code of Federal Regulations, 2011 CFR

2011-01-01

... flight training in the duties of a flight engineer. (3) A degree in aeronautical, electrical, or... (CONTINUED) AIRMEN CERTIFICATION: FLIGHT CREWMEMBERS OTHER THAN PILOTS Flight Engineers § 63.37 Aeronautical...— (1) On which a flight engineer is required by this chapter; or (2) That has at least three engines...

14 CFR 63.37 - Aeronautical experience requirements.

Code of Federal Regulations, 2010 CFR

2010-01-01

... flight training in the duties of a flight engineer. (3) A degree in aeronautical, electrical, or... (CONTINUED) AIRMEN CERTIFICATION: FLIGHT CREWMEMBERS OTHER THAN PILOTS Flight Engineers § 63.37 Aeronautical...— (1) On which a flight engineer is required by this chapter; or (2) That has at least three engines...

14 CFR 63.37 - Aeronautical experience requirements.

Code of Federal Regulations, 2012 CFR

2012-01-01

... flight training in the duties of a flight engineer. (3) A degree in aeronautical, electrical, or... (CONTINUED) AIRMEN CERTIFICATION: FLIGHT CREWMEMBERS OTHER THAN PILOTS Flight Engineers § 63.37 Aeronautical...— (1) On which a flight engineer is required by this chapter; or (2) That has at least three engines...

14 CFR 63.37 - Aeronautical experience requirements.

Code of Federal Regulations, 2014 CFR

2014-01-01

... flight training in the duties of a flight engineer. (3) A degree in aeronautical, electrical, or... (CONTINUED) AIRMEN CERTIFICATION: FLIGHT CREWMEMBERS OTHER THAN PILOTS Flight Engineers § 63.37 Aeronautical...— (1) On which a flight engineer is required by this chapter; or (2) That has at least three engines...

Neurogenic plasma leakage in mouse airways

PubMed Central

Baluk, Peter; Thurston, Gavin; Murphy, Thomas J; Bunnett, Nigel W; McDonald, Donald M

1999-01-01

This study sought to determine whether neurogenic inflammation occurs in the airways by examining the effects of capsaicin or substance P on microvascular plasma leakage in the trachea and lungs of male pathogen-free C57BL/6 mice. Single bolus intravenous injections of capsaicin (0.5 and 1 μmol kg−1, i.v.) or substance P (1, 10 and 37 nmol kg−1, i.v.) failed to induce significant leakage in the trachea, assessed as extravasation of Evans blue dye, but did induce leakage in the urinary bladder and skin. Pretreatment with captopril (2.5 mg kg−1, i.v.), a selective inhibitor of angiotensin converting enzyme (ACE), either alone or in combination with phosphoramidon (2.5 mg kg−1, i.v.), a selective inhibitor of neutral endopeptidase (NEP), increased baseline leakage of Evans blue in the absence of any exogenous inflammatory mediator. The increase was reversed by the bradykinin B2 receptor antagonist Hoe 140 (0.1 mg kg−1, i.v.). After pretreatment with phosphoramidon and captopril, capsaicin increased the Evans blue leakage above the baseline in the trachea, but not in the lung. This increase was reversed by the tachykinin (NK1) receptor antagonist SR 140333 (0.7 mg kg−1, i.v.), but not by the NK2 receptor antagonist SR 48968 (1 mg kg−1, i.v.). Experiments using Monastral blue pigment as a tracer localized the leakage to postcapillary venules in the trachea and intrapulmonary bronchi, although the labelled vessels were less numerous in mice than in comparably treated rats. Blood vessels of the pulmonary circulation were not labelled. We conclude that neurogenic inflammation can occur in airways of pathogen-free mice, but only after the inhibition of enzymes that normally degrade inflammatory peptides. Neurogenic inflammation does not involve the pulmonary microvasculature. PMID:10077247

Investigation of Turbulent Tip Leakage Vortex in an Axial Water Jet Pump with Large Eddy Simulation

NASA Technical Reports Server (NTRS)

Hah, Chunill; Katz, Joseph

2012-01-01

Detailed steady and unsteady numerical studies were performed to investigate tip clearance flow in an axial water jet pump. The primary objective is to understand physics of unsteady tip clearance flow, unsteady tip leakage vortex, and cavitation inception in an axial water jet pump. Steady pressure field and resulting steady tip leakage vortex from a steady flow analysis do not seem to explain measured cavitation inception correctly. The measured flow field near the tip is unsteady and measured cavitation inception is highly transient. Flow visualization with cavitation bubbles shows that the leakage vortex is oscillating significantly and many intermittent vortex ropes are present between the suction side of the blade and the tip leakage core vortex. Although the flow field is highly transient, the overall flow structure is stable and a characteristic frequency seems to exist. To capture relevant flow physics as much as possible, a Reynolds-averaged Navier-Stokes (RANS) calculation and a Large Eddy Simulation (LES) were applied for the current investigation. The present study reveals that several vortices from the tip leakage vortex system cross the tip gap of the adjacent blade periodically. Sudden changes in local pressure field inside tip gap due to these vortices create vortex ropes. The instantaneous pressure filed inside the tip gap is drastically different from that of the steady flow simulation. Unsteady flow simulation which can calculate unsteady vortex motion is necessary to calculate cavitation inception accurately even at design flow condition in such a water jet pump.

Quantification and characterization of leakage errors

NASA Astrophysics Data System (ADS)

Wood, Christopher J.; Gambetta, Jay M.

2018-03-01

We present a general framework for the quantification and characterization of leakage errors that result when a quantum system is encoded in the subspace of a larger system. To do this we introduce metrics for quantifying the coherent and incoherent properties of the resulting errors and we illustrate this framework with several examples relevant to superconducting qubits. In particular, we propose two quantities, the leakage and seepage rates, which together with average gate fidelity allow for characterizing the average performance of quantum gates in the presence of leakage and show how the randomized benchmarking protocol can be modified to enable the robust estimation of all three quantities for a Clifford gate set.

Conversion of the Aeronautics Interactive Workstation

NASA Technical Reports Server (NTRS)

Riveras, Nykkita L.

2004-01-01

This summer I am working in the Educational Programs Office. My task is to convert the Aeronautics Interactive Workstation from a Macintosh (Mac) platform to a Personal Computer (PC) platform. The Aeronautics Interactive Workstation is a workstation in the Aerospace Educational Laboratory (AEL), which is one of the three components of the Science, Engineering, Mathematics, and Aerospace Academy (SEMAA). The AEL is a state-of-the-art, electronically enhanced, computerized classroom that puts cutting-edge technology at the fingertips of participating students. It provides a unique learning experience regarding aerospace technology that features activities equipped with aerospace hardware and software that model real-world challenges. The Aeronautics Interactive Workstation, in particular, offers a variety of activities pertaining to the history of aeronautics. When the Aeronautics Interactive Workstation was first implemented into the AEL it was designed with Macromedia Director 4 for a Mac. Today it is being converted to Macromedia DirectorMX2004 for a PC. Macromedia Director is the proven multimedia tool for building rich content and applications for CDs, DVDs, kiosks, and the Internet. It handles the widest variety of media and offers powerful features for building rich content that delivers red results, integrating interactive audio, video, bitmaps, vectors, text, fonts, and more. Macromedia Director currently offers two programmingkripting languages: Lingo, which is Director's own programmingkripting language and JavaScript. In the workstation, Lingo is used in the programming/scripting since it was the only language in use when the workstation was created. Since the workstation was created with an older version of Macromedia Director it hosted significantly different programming/scripting protocols. In order to successfully accomplish my task, the final product required correction of Xtra and programming/scripting errors. I also had to convert the Mac platform

Aeronautical Engineering: A Continuing Bibliography with Indexes

NASA Technical Reports Server (NTRS)

1999-01-01

This supplemental issue of Aeronautical Engineering: A Continuing Bibliography with Indexes lists reports, articles, and other documents recently announced in the NASA STI Database. The coverage includes documents on the engineering and theoretical aspects of design, construction, evaluation, testing, operation, and performance of aircraft (including aircraft engines) and associated components, equipment, and systems. It also includes research and development in aerodynamics, aeronautics, and ground support equipment for aeronautical vehicles. Each entry in the publication consists of a standard bibliographic citation accompanied, in most cases, by an abstract. The NASA CASI price code table, addresses of organizations, and document availability information are included before the abstract section. Two indexes-subject and author are included after the abstract section.

Ship cabin leakage alarm based on ARM SCM

NASA Astrophysics Data System (ADS)

Qu, Liyan

2018-03-01

If there is a leakage in the cabin of a sailing ship, it is a major accident that threatens the personnel and property of the ship. If we can’t take timely measures, there will be a devastating disaster. In order to judge the leakage of the cabin, it is necessary to set up a leakage alarm system, so as to achieve the purpose of detecting and alarming the leakage of the cabin, and avoid the occurrence of accidents. This paper discusses the design of ship cabin leakage alarm system based on ARM SCM. In order to ensure the stability and precision of the product, the hardware design of the alarm system is carried out, such as circuit design, software design, the programming of SCM, the software programming of upper computer, etc. It is hoped that it can be of reference value to interested readers.

Multibeam satellite EIRP adaptability for aeronautical communications.

NASA Technical Reports Server (NTRS)

Kinal, G. V.; Bisaga, J. J.

1973-01-01

EIRP enhancement and management techniques, emphasizing aeronautical communications and adaptable multibeam concepts, are classified and characterized. User requirement and demand characteristics that exploit the improvement available from each technique are identified, and the relative performance improvement of each is discussed. It is concluded that aeronautical satellite communications could benefit greatly by the employment of these techniques.

Leakage current-induced effects in the silicon microstrip and gas electron multiplier readout chain and their compensation method

NASA Astrophysics Data System (ADS)

Zubrzycka, W.; Kasinski, K.

2018-04-01

Leakage current flowing into the charge sensitive amplifier (CSA) is a common issue in many radiation detection systems as it can increase overall system noise, shift a DC baseline or even lead a recording channel to instability. The commonly known leakage current contributor is a detector, however other system components like wires or an input protection circuit may become a serious problem. Compensation of the leakage current resulting from the electrostatic discharge (ESD) protection circuit by properly sizing its components is possible only for a narrow temperature range. Moreover, the leakage current from external sources can be significantly larger. Many applications, especially High Energy Physics (HEP) experiments, require a fast baseline restoration for high input hit rates by applying either a low-value feedback resistor or a high feedback resistance combined with a pulsed reset circuit. Leakage current flowing in the feedback in conjunction with a large feedback resistance supplied with a pulsed reset results in a significant voltage offset between the CSA input and output which can cause problems (e.g. fake hits or instability). This paper shows an issue referred to the leakage current of the ESD protection circuit flowing into the input amplifier. The following analysis and proposed solution is a result of the time and energy readout ASIC project realization for the Compressed Baryonic Matter (CBM) experiment at FAIR (Facility for Antiproton and Ion Research) in Darmstadt, Germany. This chip is purposed to work with microstrip and gaseous detectors, with high average input pulses frequencies (250 kHit/s per channel) and the possibility to process input charge of both polarities. We present measurements of the test structure fabricated in UMC 180 nm technology and propose a solution addressing leakage current related issues. This work combines the leakage current compensation capabilities at the CSA level with high, controllable value of the amplifier

A Location Method Using Sensor Arrays for Continuous Gas Leakage in Integrally Stiffened Plates Based on the Acoustic Characteristics of the Stiffener

PubMed Central

Bian, Xu; Li, Yibo; Feng, Hao; Wang, Jiaqiang; Qi, Lei; Jin, Shijiu

2015-01-01

This paper proposes a continuous leakage location method based on the ultrasonic array sensor, which is specific to continuous gas leakage in a pressure container with an integral stiffener. This method collects the ultrasonic signals generated from the leakage hole through the piezoelectric ultrasonic sensor array, and analyzes the space-time correlation of every collected signal in the array. Meanwhile, it combines with the method of frequency compensation and superposition in time domain (SITD), based on the acoustic characteristics of the stiffener, to obtain a high-accuracy location result on the stiffener wall. According to the experimental results, the method successfully solves the orientation problem concerning continuous ultrasonic signals generated from leakage sources, and acquires high accuracy location information on the leakage source using a combination of multiple sets of orienting results. The mean value of location absolute error is 13.51 mm on the one-square-meter plate with an integral stiffener (4 mm width; 20 mm height; 197 mm spacing), and the maximum location absolute error is generally within a ±25 mm interval. PMID:26404316

SENSITIVITY OF THE HOUSE PRESSURE TEST FOR DUCT LEAKAGE TO VARIATIONS IN THE DISTRIBUTION OF AIR LEAKAGE IN THE HOUSE ENVELOPE

DOE Office of Scientific and Technical Information (OSTI.GOV)

ANDREWS,J.W.

1998-12-01

The house pressure test for air leakage in ducts calculates the signed difference between the supply and return leakage from the response of the air pressure in the house to operation of the system fan. The currently accepted version of this calculation was based on particular assumptions about how the house envelope leakage is distributed between the walls, ceiling, and floor. This report generalizes the equation to account for an arbitrary distribution of envelope leakage. It concludes that the currently accepted equation is usually accurate to within {+-}5%, but in a small proportion of cases the results may diverge bymore » 50% or more.« less

Cerebrospinal fluid leakage into the subdural space: possible influence on the pathogenesis and recurrence frequency of chronic subdural hematoma and subdural hygroma.

PubMed

Kristof, Rudolf A; Grimm, Jochen M; Stoffel-Wagner, Birgit

2008-02-01

The purpose of this study was to clarify whether cerebrospinal fluid (CSF) leakage into the subdural space is involved in the genesis of chronic subdural hematoma (CSDH) and subdural hygroma (SH) and to clarify whether this leakage of CSF into the subdural space influences the postoperative recurrence rate of CSDH and SH. In this prospective observational study, 75 cases involving patients treated surgically for CSDH (67 patients) or SH (8 patients) were evaluated with respect to clinical and radiological findings at presentation, the content of beta -trace protein (beta TP) in the subdural fluid (betaTPSF) and serum (betaTPSER), and the CSDH/SH recurrence rate. The betaTPSF was considered to indicate an admixture of CSF to the subdural fluid if betaTPSF/betaTPSER>2. The median beta TPSF level for the whole patient group was 4.29 mg/L (range 0.33-51 mg/L). Cerebrospinal fluid leakage, as indicated by betaTPSF/betaTPSER>2, was found to be present in 93% of the patients with CSDH and in 100% of the patients with SH (p=0.724). In patients who later had to undergo repeated surgery for recurrence of CSDH/SH, the betaTPSF concentrations (median 6.69 mg/L, range 0.59-51 mg/L) were significantly higher (p=0.04) than in patients not requiring reoperation (median 4.12 mg/L, range 0.33-26.8 mg/L). As indicated by the presence of betaTP in the subdural fluid, CSF leakage into the subdural space is present in the vast majority of patients with CSDH and SH. This leakage could be involved in the pathogenesis of CSDH and SH. Patients who experience recurrences of CSDH and SH have significantly higher concentrations of betaTPSF at initial presentation than patients not requiring reoperation for recurrence. These findings are presented in the literature for the first time and have to be confirmed and expanded upon by further studies.

Accidental Bowel Leakage

MedlinePlus

... Women with a bowel control problem may leak gas or liquid or solid stool. Other symptoms may include the ... which can lead to leakage of solid or liquid stool (feces) or gas. Anoscopy: An exam of the anus using an ...

Gas-path leakage seal for a gas turbine

DOEpatents

Wolfe, C.E.; Dinc, O.S.; Bagepalli, B.S.; Correia, V.H.; Aksit, M.F.

1996-04-23

A gas-path leakage seal is described for generally sealing a gas-path leakage-gap between spaced-apart first and second members of a gas turbine (such as combustor casing segments). The seal includes a generally imperforate foil-layer assemblage which is generally impervious to gas and is located in the leakage-gap. The seal also includes a cloth-layer assemblage generally enclosingly contacting the foil-layer assemblage. In one seal, the first edge of the foil-layer assemblage is left exposed, and the foil-layer assemblage resiliently contacts the first member near the first edge to reduce leakage in the ``plane`` of the cloth-layer assemblage under conditions which include differential thermal growth of the two members. In another seal, such leakage is reduced by having a first weld-bead which permeates the cloth-layer assemblage, is attached to the metal-foil-layer assemblage near the first edge, and unattachedly contacts the first member. 4 figs.

Gas-path leakage seal for a gas turbine

DOEpatents

Wolfe, Christopher E.; Dinc, Osman S.; Bagepalli, Bharat S.; Correia, Victor H.; Aksit, Mahmut F.

1996-01-01

A gas-path leakage seal for generally sealing a gas-path leakage-gap between spaced-apart first and second members of a gas turbine (such as combustor casing segments). The seal includes a generally imperforate foil-layer assemblage which is generally impervious to gas and is located in the leakage-gap. The seal also includes a cloth-layer assemblage generally enclosingly contacting the foil-layer assemblage. In one seal, the first edge of the foil-layer assemblage is left exposed, and the foil-layer assemblage resiliently contacts the first member near the first edge to reduce leakage in the "plane" of the cloth-layer assemblage under conditions which include differential thermal growth of the two members. In another seal, such leakage is reduced by having a first weld-bead which permeates the cloth-layer assemblage, is attached to the metal-foil-layer assemblage near the first edge, and unattachedly contacts the first member.

Bag Test Measures Leakage From Insulated Pipe

NASA Technical Reports Server (NTRS)

Schock, Kent D.; Easter, Barry P.

1994-01-01

Test quantifies leakage of gas from pipe even though pipe covered with insulation. Involves use of helium analyzer to measure concentration of helium in impermeable bag around pipe. Test administered after standard soap-solution bubble test indicates presence and general class of leakage.

Aeronautical Engineering: A Continuing Bibliography with Indexes

NASA Technical Reports Server (NTRS)

1999-01-01

This supplemental issue of Aeronautical Engineering, A Continuing Bibliography with Indexes (NASA/SP-1999-7037) lists reports, articles, and other documents recently announced in the NASA STI Database. The coverage includes documents on the engineering and theoretical aspects of design, construction, evaluation, testing, operation, and performance of aircraft (including aircraft engines) and associated components, equipment, and systems. It also includes research and development in aerodynamics, aeronautics, and ground support equipment for aeronautical vehicles. Each entry in the publication consists of a standard bibliographic citation accompanied, in most cases, by an abstract. The NASA CASI price code table, addresses of organizations, and document availability information are included before the abstract section. Two indexes-subject and author are included after the abstract section.

Apparatus for detecting leakage of liquid sodium

DOEpatents

Himeno, Yoshiaki

1978-01-01

An apparatus for detecting the leakage of liquid sodium includes a cable-like sensor adapted to be secured to a wall of piping or other equipment having sodium on the opposite side of the wall, and the sensor includes a core wire electrically connected to the wall through a leak current detector and a power source. An accidental leakage of the liquid sodium causes the corrosion of a metallic layer and an insulative layer of the sensor by products resulted from a reaction of sodium with water or oxygen in the atmospheric air so as to decrease the resistance between the core wire and the wall. Thus, the leakage is detected as an increase in the leaking electrical current. The apparatus is especially adapted for use in detecting the leakage of liquid sodium from sodium-conveying pipes or equipment in a fast breeder reactor.

14 CFR 61.160 - Aeronautical experience-airplane category restricted privileges.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Aeronautical experience-airplane category... INSTRUCTORS Airline Transport Pilots § 61.160 Aeronautical experience—airplane category restricted privileges... pilot may apply for an airline transport pilot certificate with an airplane category multiengine class...

Leakage current conduction in metal gate junctionless nanowire transistors

NASA Astrophysics Data System (ADS)

Oproglidis, T. A.; Karatsori, T. A.; Barraud, S.; Ghibaudo, G.; Dimitriadis, C. A.

2017-05-01

In this paper, the experimental off-state drain leakage current behavior is systematically explored in n- and p-channel junctionless nanowire transistors with HfSiON/TiN/p+-polysilicon gate stack. The analysis of the drain leakage current is based on experimental data of the gate leakage current. It has been shown that the off-state drain leakage current in n-channel devices is negligible, whereas in p-channel devices it is significant and dramatically increases with drain voltage. The overall results indicate that the off-state drain leakage current in p-channel devices is mainly due to trap-assisted Fowler-Nordheim tunneling of electrons through the gate oxide of electrons from the metal gate to the silicon layer near the drain region.

Energy Efficient High-Pressure Turbine Leakage Technology Report

NASA Technical Reports Server (NTRS)

Gardner, W. B.

1980-01-01

The leakage test program was one of such supporting technology programs structured to provide guidance to the Energy Efficient Engine High Pressure Turbine Component Design Effort. Leakage reduction techniques were identified and evaluated. Test models were used to simulate component leak paths and to evaluate leakage reduction techniques. These models simulated the blade/disk attachment, the vane inner platform attachment, and the vane outer platform attachment combined with the blade outer airseal. Disk blade attachment testing indicated that leakage in this area could be reduced to very low levels by paying careful attention to the tolerances along the contact surface between the blade vibration damper and the blade platform contact surface. The aim of feather seal testing was to achieve a goal for an effective leakage gap of one mil (.001 inch) per inch of feather seal length. Results indicated that effective gaps even below the goal level were achievable by (1) maintaining close tolerances between feather seals and their slots to minimize end gaps and limit seal rotation, (2) avoiding feather seal overlap, and (3) minimizing feather seal intersections. W seals were shown to be effective leakage control devices. Wire rope, in its present state of development, was shown not to be an effective sealing concept for application to the component design.

A cumulative index to Aeronautical Engineering: A continuing bibliography

NASA Technical Reports Server (NTRS)

1982-01-01

This bibliography is a cumulated index to the abstracts contained in NASA SP-7037(132) through NASA SP-7037(143) of Aeronautical Engineering: A continuing bibliography. NASA SP-7037 and its supplements have been compiled through the cooperative efforts of the American Institute of Aeronautics and Astronautics (AIAA) and the National Aeronautics and Space Administration (NASA). This cumulative index includes subject, personal author, corporate source, contract, and report number indexes.

Progress Toward National Aeronautics Goals

NASA Technical Reports Server (NTRS)

Russo, Carlo J.; Sehra, Arun K.

1999-01-01

NASA has made definitive progress towards achieving several bold U.S. goals in aeronautics related to air breathing engines. The advanced technologies developed towards these goals span applications from general aviation to large subsonic and supersonic aircraft. The proof of successful technology development is demonstrated through successful technology transfer to U.S. industry and projected fleet impact. Specific examples of progress are discussed that quantifies the achievement towards these goals. In addition, a more detailed vision for NASA aeronautics is defined and key strategic issues are explored which invite international and national debate and involvement especially in reduced environmental impact for subsonic and supersonic aircraft, dramatic new capabilities in general aviation engines, and reduced development cycle time and costs.

49 CFR 178.345-13 - Pressure and leakage tests.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 false Pressure and leakage tests. 178.345-13 Section 178... PACKAGINGS Specifications for Containers for Motor Vehicle Transportation § 178.345-13 Pressure and leakage tests. (a) Each cargo tank must be pressure and leakage tested in accordance with this section and...

14 CFR 61.163 - Aeronautical experience: Powered-lift category rating.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Aeronautical experience: Powered-lift... Transport Pilots § 61.163 Aeronautical experience: Powered-lift category rating. (a) A person who is applying for an airline transport pilot certificate with a powered-lift category rating must have at least...

14 CFR 61.163 - Aeronautical experience: Powered-lift category rating.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Aeronautical experience: Powered-lift... Transport Pilots § 61.163 Aeronautical experience: Powered-lift category rating. (a) A person who is applying for an airline transport pilot certificate with a powered-lift category rating must have at least...

Aeronautical Engineering: A Continuing Bibliography with Indexes

NASA Technical Reports Server (NTRS)

1995-01-01

This bibliography lists 193 reports, journal articles, and other documents introduced in the NASA scientific and technical system in Aug. 1995. Subject coverage includes documents on the engineering and theoretical aspects of design, construction, evaluation, testing, operation, and performance of aircraft (including aircraft engines) and associated components, equipment, and systems. It also includes research and development in aerodynamics, aeronautics, and ground support equipment for aeronautical vehicles

77 FR 13683 - Government/Industry Aeronautical Charting Forum Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-07

.... Watson, FAA, National Aeronautical Navigation Products (AeroNav Products), Quality Assurance & Regulatory..., on February 28, 2012. Valerie S. Watson, Co-Chair, Aeronautical Charting Forum. [FR Doc. 2012-5293...

Aeronautics and space report of the President: 1981 activities

NASA Technical Reports Server (NTRS)

1981-01-01

Achievements in the aeronautics and space program by function are summarized. Activities in communications, Earth's resources and environment, space science, space transportation, international activities, and aeronautics are included.

Aeronautical engineering: A cumulative index to a continuing bibliography

NASA Technical Reports Server (NTRS)

1987-01-01

This bibliography is a cumulative index to the abstracts contained in NASA SP-7037 (197) through NASA SP-7037 (208) of Aeronautical Engineering: A Continuing Bibliography. NASA SP-7037 and its supplements have been compiled through the cooperative efforts of the American Institute of Aeronautics and Astronautics (AIAA) and the National Aeronautics and Space Administration (NASA). This cumulative index includes subject, personal author, corporate source, foreign technology, contract, report number, and accession number indexes.

Aeronautical engineering: A cumulative index to a continuing bibliography

NASA Technical Reports Server (NTRS)

1988-01-01

This bibliography is a cumulative index to the abstracts contained in NASA SP-7037(210) through NASA SP-7037(221) of Aeronautical Engineering: A Continuing Bibliography. NASA SP-7037 and its supplements have been compiled through the cooperative efforts of the American Institute of Aeronautics and Astronautics (AIAA) and the National Aeronautics and Space Administration (NASA). This cumulative index includes subject, personal author, corporate source, foreign technology, contract number, report number, and accession number indexes.

An Overview of the NASA Aeronautics Test Program Strategic Plan

NASA Technical Reports Server (NTRS)

Marshall, Timothy J.

2010-01-01

U.S. leadership in aeronautics depends on ready access to technologically advanced, efficient, and affordable aeronautics test capabilities. These systems include major wind tunnels and propulsion test facilities and flight test capabilities. The federal government owns the majority of the major aeronautics test capabilities in the United States, primarily through the National Aeronautics and Space Administration (NASA) and the Department of Defense (DoD), however an overarching strategy for management of these national assets was needed. Therefore, in Fiscal Year (FY) 2006 NASA established the Aeronautics Test Program (ATP) as a two-pronged strategic initiative to: (1) retain and invest in NASA aeronautics test capabilities considered strategically important to the agency and the nation, and (2) establish a strong, high level partnership with the DoD Test Resources Management Center (TRMC), stewards of the DoD test and evaluation infrastructure. Since then, approximately seventy percent of the ATP budget has been directed to underpin fixed and variable costs of facility operations within its portfolio and the balance towards strategic investments in its test facilities, including maintenance and capability upgrades. Also, a strong guiding coalition was established through the National Partnership for Aeronautics Testing (NPAT), with governance by the senior leadership of NASA s Aeronautics Research Mission Directorate (ARMD) and the DoD's TRMC. As part of its strategic planning, ATP has performed or participated in many studies and analyses, including assessments of major NASA and DoD aeronautics test capabilities, test facility condition evaluations and market research. The ATP strategy has also benefitted from unpublished RAND research and analysis by Ant n et al. (2009). Together, these various studies, reports and assessments serve as a foundation for a new, five year strategic plan that will guide ATP through FY 2014. Our vision for the future is a balanced

Emerging Options and Opportunities in Civilian Aeronautics

NASA Technical Reports Server (NTRS)

Bushnell, Dennis M.

2012-01-01

This paper addresses the major problems/issues with civilian aeronautics going forward, the contextual ongoing technology revolutions, the several emerging civilian aeronautical "Big Ideas" and associated enabling technological approaches. The ongoing IT Revolution is increasingly providing, as 5 senses virtual presence/reality becomes available, along with Nano/Molecular Manufacturing, virtual alternatives to Physical transportation for both people and goods. Paper examines the potential options available to aeronautics to maintain and perhaps grow "market share" in the context of this evolving competition. Many of these concepts are not new, but the emerging technology landscape is enhancing their viability and marketability. The concepts vary from the "interesting" to the truly revolutionary and all require considerable research. Paper considers the speed range from personal/general aviation to supersonic transports and technologies from energetics to fabrication.

78 FR 12415 - Government/Industry Aeronautical Charting Forum Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-22

... Valerie S. Watson, FAA, National Aeronautical Navigation Products (AeroNav Products), Quality Assurance.... Issued in Washington, DC, on February 19, 2013. Valerie S. Watson, Co-Chair, Aeronautical Charting Forum...

49 CFR 178.345-13 - Pressure and leakage tests.

Code of Federal Regulations, 2014 CFR

2014-10-01

... entire cargo tank surface is inspected for leakage and other sign of defects. The inspection method must... Specifications for Containers for Motor Vehicle Transportation § 178.345-13 Pressure and leakage tests. (a) Each cargo tank must be pressure and leakage tested in accordance with this section and §§ 178.346-5, 178.347...

49 CFR 178.345-13 - Pressure and leakage tests.

Code of Federal Regulations, 2012 CFR

2012-10-01

... entire cargo tank surface is inspected for leakage and other sign of defects. The inspection method must... Specifications for Containers for Motor Vehicle Transportation § 178.345-13 Pressure and leakage tests. (a) Each cargo tank must be pressure and leakage tested in accordance with this section and §§ 178.346-5, 178.347...

49 CFR 178.345-13 - Pressure and leakage tests.

Code of Federal Regulations, 2013 CFR

2013-10-01

... entire cargo tank surface is inspected for leakage and other sign of defects. The inspection method must... Specifications for Containers for Motor Vehicle Transportation § 178.345-13 Pressure and leakage tests. (a) Each cargo tank must be pressure and leakage tested in accordance with this section and §§ 178.346-5, 178.347...

49 CFR 178.345-13 - Pressure and leakage tests.

Code of Federal Regulations, 2011 CFR

2011-10-01

... entire cargo tank surface is inspected for leakage and other sign of defects. The inspection method must... Specifications for Containers for Motor Vehicle Transportation § 178.345-13 Pressure and leakage tests. (a) Each cargo tank must be pressure and leakage tested in accordance with this section and §§ 178.346-5, 178.347...

Detecting the leakage source of a reservoir using isotopes.

PubMed

Yi, Peng; Yang, Jing; Wang, Yongdong; Mugwanezal, Vincent de Paul; Chen, Li; Aldahan, Ala

2018-07-01

A good monitoring method is vital for understanding the sources of a water reservoir leakage and planning for effective restoring. Here we present a combination of several tracers ( 222 Rn, oxygen and hydrogen isotopes, anions and temperature) for identification of water leakage sources in the Pushihe pumped storage power station which is in the Liaoning province, China. The results show an average 222 Rn activity of 6843 Bq/m 3 in the leakage water, 3034 Bq/m 3 in the reservoir water, and 41,759 Bq/m 3 in the groundwater. Considering that 222 Rn activity in surface water is typically less than 5000 Bq/m 3 , the low level average 222 Rn activity in the leakage water suggests the reservoir water as the main source of water. Results of the oxygen and hydrogen isotopes show comparable ranges and values in the reservoir and the leakage water samples. However, important contribution of the groundwater (up to 36%) was present in some samples from the bottom and upper parts of the underground powerhouse, while the leakage water from some other parts indicate the reservoir water as the dominant source. The isotopic finding suggests that the reservoir water is the main source of the leakage water which is confirmed by the analysis of anions (nitrate, sulfate, and chloride) in the water samples. The combination of these tracer methods for studying dam water leakage improves the accuracy of identifying the source of leaks and provide a scientific reference for engineering solutions to ensure the dam safety. Copyright © 2018 Elsevier Ltd. All rights reserved.

NASA's Role in Aeronautics: A Workshop. Volume II - Military Aviation.

ERIC Educational Resources Information Center

National Academy of Sciences - National Research Council, Washington, DC. Assembly of Engineering.

The central task of a 1980 workshop on the role of the National Aeronautics and Space Administration (NASA) in aeronautics was to examine the relationship of NASA's research capabilities to the state of U.S. aviation and to make recommendations about NASA's future role in aeronautics. The findings and recommendations of the Panel on Military…

Indocyanine green staining facilitates detection of bleb leakage during trabeculectomy.

PubMed

Okazaki, Teruhiko; Kiuchi, Takahiro; Kawana, Keisuke; Oshika, Tetsuro

2007-03-01

To report a new technique to visualize bleb leakage using indocyanine green (ICG) staining during trabeculectomy. The ICG solution was widely applied over the filtering bleb including the conjunctival wound before completion of trabeculectomy. This procedure was performed in 48 eyes of 44 consecutive patients undergoing trabeculectomy between December 2004 and October 2005. Without staining, bleb leakage was not identified by the direct observation under the operating microscope. ICG staining clearly visualized aqueous leakage from the bleb in 5 eyes (10.4%). The bleb leakage in these eyes was easily repaired with 10-0 nylon sutures, and no eyes, including these 5 cases, showed bleb leakage after surgery. There were no intraoperative and postoperative complications related to ICG application. The application of ICG during trabeculectomy is a simple and useful technique to facilitate detection and repair of the bleb leakage.

Magnetotelluric Detection Thresholds as a Function of Leakage Plume Depth, TDS and Volume

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, X.; Buscheck, T. A.; Mansoor, K.

We conducted a synthetic magnetotelluric (MT) data analysis to establish a set of specific thresholds of plume depth, TDS concentration and volume for detection of brine and CO 2 leakage from legacy wells into shallow aquifers in support of Strategic Monitoring Subtask 4.1 of the US DOE National Risk Assessment Partnership (NRAP Phase II), which is to develop geophysical forward modeling tools. 900 synthetic MT data sets span 9 plume depths, 10 TDS concentrations and 10 plume volumes. The monitoring protocol consisted of 10 MT stations in a 2×5 grid laid out along the flow direction. We model the MTmore » response in the audio frequency range of 1 Hz to 10 kHz with a 50 Ωm baseline resistivity and the maximum depth up to 2000 m. Scatter plots show the MT detection thresholds for a trio of plume depth, TDS concentration and volume. Plumes with a large volume and high TDS located at a shallow depth produce a strong MT signal. We demonstrate that the MT method with surface based sensors can detect a brine and CO 2 plume so long as the plume depth, TDS concentration and volume are above the thresholds. However, it is unlikely to detect a plume at a depth larger than 1000 m with the change of TDS concentration smaller than 10%. Simulated aquifer impact data based on the Kimberlina site provides a more realistic view of the leakage plume distribution than rectangular synthetic plumes in this sensitivity study, and it will be used to estimate MT responses over simulated brine and CO 2 plumes and to evaluate the leakage detectability. Integration of the simulated aquifer impact data and the MT method into the NRAP DREAM tool may provide an optimized MT survey configuration for MT data collection. This study presents a viable approach for sensitivity study of geophysical monitoring methods for leakage detection. The results come in handy for rapid assessment of leakage detectability.« less

NASA's Role in Aeronautics: A Workshop. Volume III - Transport Aircraft.

ERIC Educational Resources Information Center

National Academy of Sciences - National Research Council, Washington, DC. Assembly of Engineering.

The central task of a 1980 workshop on the role of the National Aeronautics and Space Administration (NASA) in aeronautics was to examine the relationship of NASA's research capabilities to the state of U.S. aviation and to make recommendations about NASA's future role in aeronautics. The specific task of the Panel on Transport Aircraft was to…

[Bile leakage after liver resection: A retrospective cohort study].

PubMed

Menclová, K; Bělina, F; Pudil, J; Langer, D; Ryska, M

2015-12-01

Many previous reports have focused on bile leakage after liver resection. Despite the improvements in surgical techniques and perioperative care the incidence of this complication rather keeps increasing. A number of predictive factors have been analyzed. There is still no consensus regarding their influence on the formation of bile leakage. The objective of our analysis was to evaluate the incidence of bile leakage, its impact on mortality and duration of hospitalization at our department. At the same time, we conducted an analysis of known predictive factors. The authors present a retrospective review of the set of 146 patients who underwent liver resection at the Department of Surgery of the 2nd Faculty of Medicine of the Charles University and Central Military Hospital Prague, performed between 20102013. We used the current ISGLS (International Study Group of Liver Surgery) classification to evaluate the bile leakage. The severity of this complication was determined according to the Clavien-Dindo classification system. Statistical significance of the predictive factors was determined using Fishers exact test and Students t-test. The incidence of bile leakage was 21%. According to ISGLS classification the A, B, and C rates were 6.5%, 61.2%, and 32.3%, respectively. The severity of bile leakage according to the Clavien-Dindo classification system - I-II, IIIa, IIIb, IV and V rates were 19.3%, 42%, 9.7%, 9.7%, and 19.3%, respectively. We determined the following predictive factors as statistically significant: surgery for malignancy (p<0.001), major hepatic resection (p=0.001), operative time (p<0.001), high intraoperative blood loss (p=0.02), construction of HJA (p=0.005), portal venous embolization/two-stage surgery (p=0.009) and ASA score (p=0.02). Bile leakage significantly prolonged hospitalization time (p<0.001). In the group of patients with bile leakage the perioperative mortality was 23 times higher (p<0.001) than in the group with no leakage. Bile

Rarity of late anastomotic leakage after low anterior resection of the rectum.

PubMed

Maeda, Hiromichi; Okamoto, Ken; Namikawa, Tsutomu; Akimori, Toyokazu; Kamioka, Norihito; Shiga, Mai; Dabanaka, Ken; Hanazaki, Kazuhiro; Kobayashi, Michiya

2015-06-01

Late anastomotic leakage is reported to account for half of all anastomotic leakages after low anterior resection of the rectum. An important clinical question is whether late and early anastomotic leakages are different entities. We retrospectively reviewed the medical records of patients who experienced anastomotic leakage after low anterior resection in two Japanese hospitals. The clinical characteristics were extracted and analyzed. During the study period, 179 patients underwent low anterior resection. A pelvic drainage tube was routinely utilized in all cases and was generally removed 4 to 6 days after the operation. Twenty-six patients had anastomotic leakage; the diagnosis was based on fecal contamination of the drainage in 24 cases. The median interval between operation and detection of anastomotic leakage was 3.5 days. Anastomotic leakage was diagnosed within 7 days of the operation in 25 cases and on postoperative day 20 (after hospital discharge) in one case. There was no instance of anastomotic leakage diagnosed more than 30 days after the operation. There was no relationship between clinical variables and days of leakage diagnosis. The rarity of late anastomotic leakage in our study, compared with previous studies, may relate to the relatively extended period of pelvic drainage tube usage in our institutes, which likely shortens the interval before leakage diagnosis. Our results suggest that late anastomotic leakage is a delayed symptom of subtle early anastomotic leakage rather than a separate entity.

Risk factors, treatment and impact on outcomes of bile leakage after hemihepatectomy.

PubMed

Zheng, Si-Ming; Li, Hong; Li, Gen-Cong; Yu, Dan-Song; Ying, Dong-Jian; Zhang, Bin; Lu, Cai-De; Zhou, Xin-Hua

2017-07-01

Risk factors for bile leakage after hemihepatectomy are unknown. A prospectively maintained database review identified patients undergoing hemihepatectomy between 1 January 2009 and 30 September 2014. Patients were divided into B/C and non-B/C bile leakage groups. Risk factors for bile leakage were predicted and assessments of their impact on patients were made. Bile leakage occurred in 91 of the 297 patients (30.6%); 64 cases were classified as grade B bile leakage (21.5%) and three cases as grade C bile leakage (1.0%). Multivariate analysis confirmed that elevated preoperative alanine transaminase (ALT), positive bile culture during surgery, hilar bile duct plasty, bilioenteric anastomosis and laparoscopic surgery were risk factors for B/C grade bile leakage (P < 0.05). Percutaneous transhepatic biliary drainage (PTBD) and endoscopic nasobiliary drainage (ENBD) were protective factors for B/C grade bile leakage (P < 0.05). PTBD, ENBD and Kehr's T-tube drainage could reduce the drainage volume and duration of drainage after bile leakage (P < 0.05). The incidence of wound infection, abdominal infection, major complications and the Clavien classification system score in the B/C bile leakage group were higher than those in the non-B/C bile leakage group (P < 0.05). Patients in the B/C bile leakage group also required prolonged hospitalization (P < 0.05). The mortality of two groups was similar (P > 0.05). Patient with elevated preoperative ALT, positive bile cultures during surgery, hilar bile duct plasty, bilioenteric anastomosis and laparoscopic surgery are more likely to complicate bile leakage. We should use biliary drainage such as preoperative PTBD, ENBD or intraoperative Kehr's T-tube drainage to reduce and treat bile leakage in patients with high risk of bile leakage. © 2015 Royal Australasian College of Surgeons.

78 FR 79059 - Public Notice for Waiver of Aeronautical Land-Use Assurance

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-27

... proposal to change approximately 44.7 acres of airport land from aeronautical use to non-aeronautical use... Aeronautical Land-Use Assurance AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of intent of... aforementioned land is not needed for aeronautical use. The property is located near the southeast corner of...

Use of complex frequency plane to design broadband and sub-wavelength absorbers.

PubMed

Romero-García, V; Theocharis, G; Richoux, O; Pagneux, V

2016-06-01

The reflection of sound of frequency below 1 kHz, by a rigid-backed structure that contains sub-wavelength resonators is studied in this work. In particular, only single mode reflected waves are considered, an approximation which is accurate in this low frequency regime. A method of analysis of absorption that uses the structure of the reflection coefficient in the complex frequency plane is proposed. In the absence of losses, the reflection coefficient supports pairs of poles and zeros that are complex conjugate and which have imaginary parts linked to the energy leakage by radiation. When losses are introduced and balanced to the leakage, the critical coupling condition is satisfied and total absorption is obtained. Examples of a slot resonator and of multiple Helmholtz resonators are analyzed to obtain both narrow and broadband total absorption.

Aeronautics and space report of the president, 1974 activities

NASA Technical Reports Server (NTRS)

1975-01-01

The U.S. Government activities for 1974 in aeronautics and space are presented. Significant contributions toward the fulfillment of the nation's goals in space and aeronautics are covered, including application of space systems and technology to beneficial uses on earth, exploration of space and increase of scientific knowledge, development of improved space systems and technology, international cooperation, and advancement of civil and military aeronautics. Also in 1974, space activities in the private sector expanded to provide additional services to the public. The accomplishments are summarized.

Aeronautics: An Educator's Guide with Activities in Science, Mathematics, and Technology Education.

ERIC Educational Resources Information Center

National Aeronautics and Space Administration, Washington, DC.

This educator's guide, developed for students in grades 2-4, discusses the field of aeronautics. It begins with education standards and skill matrices for the classroom activities, a description of the National Aeronautics and Space Administration (NASA) aeronautics mission, and a brief history of aeronautics. Activities are written for the…

Bile leakage test in liver resection: A systematic review and meta-analysis

PubMed Central

Wang, Hai-Qing; Yang, Jian; Yang, Jia-Yin; Yan, Lu-Nan

2013-01-01

AIM: To assess systematically the safety and efficacy of bile leakage test in liver resection. METHODS : Randomized controlled trials and controlled clinical trials involving the bile leakage test were included in a systematic literature search. Two authors independently assessed the studies for inclusion and extracted the data. A meta-analysis was conducted to estimate postoperative bile leakage, intraoperative positive bile leakage, and complications. We used either the fixed-effects or random-effects model. RESULTS: Eight studies involving a total of 1253 patients were included and they all involved the bile leakage test in liver resection. The bile leakage test group was associated with a significant reduction in bile leakage compared with the non-bile leakage test group (RR = 0.39, 95%CI: 0.23-0.67; I2 = 3%). The white test had superiority for detection of intraoperative bile leakage compared with the saline solution test (RR = 2.38, 95%CI: 1.24-4.56, P = 0.009). No significant intergroup differences were observed in total number of complications, ileus, liver failure, intraperitoneal hemorrhage, pulmonary disorder, abdominal infection, and wound infection. CONCLUSION: The bile leakage test reduced postoperative bile leakage and did not increase incidence of complications. Fat emulsion is the best choice of solution for the test. PMID:24363535

Bile leakage test in liver resection: a systematic review and meta-analysis.

PubMed

Wang, Hai-Qing; Yang, Jian; Yang, Jia-Yin; Yan, Lu-Nan

2013-12-07

To assess systematically the safety and efficacy of bile leakage test in liver resection. Randomized controlled trials and controlled clinical trials involving the bile leakage test were included in a systematic literature search. Two authors independently assessed the studies for inclusion and extracted the data. A meta-analysis was conducted to estimate postoperative bile leakage, intraoperative positive bile leakage, and complications. We used either the fixed-effects or random-effects model. Eight studies involving a total of 1253 patients were included and they all involved the bile leakage test in liver resection. The bile leakage test group was associated with a significant reduction in bile leakage compared with the non-bile leakage test group (RR = 0.39, 95%CI: 0.23-0.67; I (2) = 3%). The white test had superiority for detection of intraoperative bile leakage compared with the saline solution test (RR = 2.38, 95%CI: 1.24-4.56, P = 0.009). No significant intergroup differences were observed in total number of complications, ileus, liver failure, intraperitoneal hemorrhage, pulmonary disorder, abdominal infection, and wound infection. The bile leakage test reduced postoperative bile leakage and did not increase incidence of complications. Fat emulsion is the best choice of solution for the test. © 2013 Baishideng Publishing Group Co., Limited. All rights reserved.

Estimation of Radiofrequency Power Leakage from Microwave Ovens for Dosimetric Assessment at Nonionizing Radiation Exposure Levels

PubMed Central

Lopez-Iturri, Peio; de Miguel-Bilbao, Silvia; Aguirre, Erik; Azpilicueta, Leire; Falcone, Francisco; Ramos, Victoria

2015-01-01

The electromagnetic field leakage levels of nonionizing radiation from a microwave oven have been estimated within a complex indoor scenario. By employing a hybrid simulation technique, based on coupling full wave simulation with an in-house developed deterministic 3D ray launching code, estimations of the observed electric field values can be obtained for the complete indoor scenario. The microwave oven can be modeled as a time- and frequency-dependent radiating source, in which leakage, basically from the microwave oven door, is propagated along the complete indoor scenario interacting with all of the elements present in it. This method can be of aid in order to assess the impact of such devices on expected exposure levels, allowing adequate minimization strategies such as optimal location to be applied. PMID:25705676

Aeronautics and space report of the President

NASA Technical Reports Server (NTRS)

1995-01-01

This report describes the activities and accomplishments of all agencies of the United States in the fields of aeronautics and space science during FY 1994. Activity summaries are presented for the following areas: space launch activities, space science, space flight and space technology, space communications, aeronuatics, and studies of the planet Earth. Several appendices providing data on U.S. launch activities, the Federal budget for space and aeronautics, remote sensing capabilities, and space policy are included.

78 FR 36013 - Public Notice for Waiver of Aeronautical Land-Use Assurance

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-14

... considering a proposal to change a 3.03-acre portion of Parcel AA of airport land from aeronautical use to non... protection of FAR Part 77 surfaces and compatible land use. The change from aeronautical to non-aeronautical... Aeronautical Land-Use Assurance AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of intent of...

Aeronautical Engineering: A Continuing Bibliography with Indexes. Supplement 387

NASA Technical Reports Server (NTRS)

1998-01-01

This supplemental issue of Aeronautical Engineering, A Continuing Bibliography with Indexes (NASA/SP-1998-7037) lists reports, articles, and other documents recently announced in the NASA STI Database. The coverage includes documents on the engineering and theoretical aspects of design, construction, evaluation, testing, operation, and performance of aircraft (including aircraft engines) and associated components, equipment, and systems. It also includes research and development in aerodynamics, aeronautics, and ground support equipment for aeronautical vehicles. Each entry in the publication consists of a standard bibliographic citation accompanied, in most cases, by an abstract.

Aeronautical Engineering: A Continuing Bibliography with Indexes. Supplement 386

NASA Technical Reports Server (NTRS)

1998-01-01

This supplemental issue of Aeronautical Engineering, A Continuing Bibliography with Indexes (NASA/SP-1998-7037) lists reports, articles, and other documents recently announced in the NASA STI Database. The coverage includes documents on the engineering and theoretical aspects of design, construction, evaluation, testing, operation, and performance of aircraft (including aircraft engines) and associated components, equipment, and systems. It also includes research and development in aerodynamics, aeronautics, and ground support equipment for aeronautical vehicles. Each entry in the publication consists of a standard bibliographic citation accompanied, in most cases, by an abstract.

Aeronautical Engineering: A Continuing Bibliography with Indexes. Supplement 389

NASA Technical Reports Server (NTRS)

1998-01-01

This supplemental issue of Aeronautical Engineering, A Continuing Bibliography with Indexes (NASA/SP-1998-7037) lists reports, articles, and other documents recently announced in the NASA STI Database. The coverage includes documents on the engineering and theoretical aspects of design, construction, evaluation, testing, operation, and performance of aircraft (including aircraft engines) and associated components, equipment, and systems. It also includes research and development in aerodynamics, aeronautics, and ground support equipment for aeronautical vehicles. Each entry in the publication consists of a standard bibliographic citation accompanied, in most cases, by an abstract.

Aeronautical Engineering: A Continuing Bibliography with Indexes. Supplement 391

NASA Technical Reports Server (NTRS)

1999-01-01

This supplemental issue of Aeronautical Engineering, A Continuing Bibliography with Indexes (NASA/SP-1999-7037) lists reports, articles, and other documents recently announced in the NASA STI Database. The coverage includes documents on the engineering and theoretical aspects of design, construction, evaluation, testing, operation, and performance of aircraft (including aircraft engines) and associated components, equipment, and systems. It also includes research and development in aerodynamics, aeronautics, and ground support equipment for aeronautical vehicles. Each entry in the publication consists of a standard bibliographic citation accompanied, in most cases, by an abstract.

A novel method to determine air leakage in heat pump clothes dryers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bansal, Pradeep; Mohabir, Amar; Miller, William

A heat pump clothes dryer offers the potential to save a significant amount of energy as compared with conventional vented electric dryers. Although heat pump clothes dryers (HPCD) offer higher energy efficiency; it has been observed that they are prone to air leakages, which inhibits the HPCD's gain in efficiency. This study serves to develop a novel method of quantifying leakage, and to determine specific leakage locations in the dryer drum and air circulation system. The basis of this method is the American Society of Testing and Materials (ASTM) standard E779 10, which is used to determine air leakage areamore » in a household ventilation system through fan pressurization. This ASTM method is adapted to the dryer system, and the leakage area is determined by an analysis of the leakage volumetric flow - pressure relationship. Easily accessible leakage points were quantified: the front and back crease (in the dryer drum), the leakage in the dryer duct, the air filter, and the remaining leakage in the drum. The procedure allows investigators to determine major components contributing to leakage in HPCDs, thus improving component design features that result in more efficient HPCD systems.« less

A novel method to determine air leakage in heat pump clothes dryers

DOE PAGES

Bansal, Pradeep; Mohabir, Amar; Miller, William

2016-01-06

A heat pump clothes dryer offers the potential to save a significant amount of energy as compared with conventional vented electric dryers. Although heat pump clothes dryers (HPCD) offer higher energy efficiency; it has been observed that they are prone to air leakages, which inhibits the HPCD's gain in efficiency. This study serves to develop a novel method of quantifying leakage, and to determine specific leakage locations in the dryer drum and air circulation system. The basis of this method is the American Society of Testing and Materials (ASTM) standard E779 10, which is used to determine air leakage areamore » in a household ventilation system through fan pressurization. This ASTM method is adapted to the dryer system, and the leakage area is determined by an analysis of the leakage volumetric flow - pressure relationship. Easily accessible leakage points were quantified: the front and back crease (in the dryer drum), the leakage in the dryer duct, the air filter, and the remaining leakage in the drum. The procedure allows investigators to determine major components contributing to leakage in HPCDs, thus improving component design features that result in more efficient HPCD systems.« less

Smart Aeronautical Chart Management System Design

NASA Astrophysics Data System (ADS)

Pakdil, M. E.; Celik, R. N.; Kaya, Ö.; Konak, Y. C.; Guney, C.

2015-10-01

Civil aviation is developing rapidly, and the number of domestic and international operations is increasing exponentially every year than the previous one. Airline companies with increased air traffic and the number of passengers increase the demand of new aircrafts. An aircraft needs not only fuel but also pilot and aeronautical information (charts, digital navigation information, flight plan, and etc.) to perform flight operation. One of the most important components in aeronautical information is the terminal chart. Authorized institution in every state is responsible to publish their terminal charts for certain periods. Although these charts are produced in accordance with ICAO's Annex 4 and Annex 15, cartographic representation and page layout differs in each state's publication. This situation makes difficult to read them by pilots. In this paper, standard instrument departure (SID) charts are analysed to produce by use of cutting-edge and competitive technologies instead of classical computer-aided drawing and vector based graphic applications that are currently used by main chart producers. The goal is to design efficient and commercial chart management system that is able to produce aeronautical charts with same cartographic representation for all states.

Enhanced ground bounce noise reduction in a low-leakage CMOS multiplier

NASA Astrophysics Data System (ADS)

Verma, Bipin Kumar; Akashe, Shyam; Sharma, Sanjay

2015-09-01

In this paper, various parameters are used to reduce leakage power, leakage current and noise margin of circuits to enhance their performance. A multiplier is proposed with low-leakage current and low ground bounce noise for the microprocessor, digital signal processors (DSP) and graphics engines. The ground bounce noise problem appears when a conventional power-gating circuit transits from sleep-to-active mode. This paper discusses a reduction in leakage current in the stacking power-gating technique by three modes - sleep, active and sleep-to-active. The simulation results are performed on a 4 × 4 carry-save multiplier for leakage current, active power, leakage power and ground bounce noise, and comparison made for different nanoscales. Ground bounce noise is limited to 90%. The leakage current of the circuit is decimated up to 80% and the active power is reduced to 31%. We performed simulations using cadence virtuoso 180 and 45 nm at room temperature at various supply voltages.

Multibeam Aeronautical Satellite System Design.

DOT National Transportation Integrated Search

1971-12-01

A method is described which allows the identification of favored beam distributions for multiple beam aeronautical satellites. It is used to synthesize beam designs and compare the capacities of two satellite system configurations which cover the maj...

47 CFR 87.279 - Frequencies.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Aeronautical Fixed Stations § 87.279 Frequencies. (a) United States (except Alaska). The applicant must request... in § 87.263(c). kHz 2648.0 5310.0 4645.0 5887.5 4947.5 8015.0 5122.5 (c) Gulf of Mexico. In addition... available in the Gulf of Mexico. Aircraft Data Link Land Test Stations ...

Can acoustic emission detect the initiation of fatigue cracks: Application to high-strength light alloys used in aeronautics

NASA Technical Reports Server (NTRS)

Bathias, C.; Brinet, B.; Sertour, G.

1978-01-01

Acoustic emission was used for the detection of fatigue cracking in a number of high-strength light alloys used in aeronautical structures. Among the features studied were: the influence of emission frequency, the effect of surface oxidation, and the influence of grains. It was concluded that acoustic emission is an effective nondestructive technique for evaluating the initiation of fatigue cracking in such materials.

NASA's Role in Aeronautics: A Workshop. Volume 1: Summary

NASA Technical Reports Server (NTRS)

1981-01-01

The state of the U.S. aeronautic industry and progressive changes in national priorities as reflected in federal unified budget outlays are reviewed as well as the contribution of NACA and the character and substance of U.S. aeronautical research under NASA. Eight possible roles for the future defined by NASA are examined and the extent to which the agency should carry out these activities is considered. The roles include: (1) national facilities expertise; (2) flight sciences research; (3) generic technology evolution; (4) vehicle class evolution; (5) technology demonstration; (6) prototype development; (7) technology validation; and (8) operations feasibility; How NASA's roles varies in the areas of military aviation, general aviation, transport aircraft aeronautics, rotorcraft aeronautics, engineering education, information dissemination, and cooperation with other organizations and agencies is discussed with regard to research in aerodynamics; structures and materials; propulsion; electronics and avionics; vehicle operations; and human engineering.

78 FR 73919 - Public Notice for Waiver of Aeronautical Land-Use Assurance

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-09

... considering a proposal to change 24.19 acres of airport land from aeronautical use to non-aeronautical use of... Aeronautical Land-Use Assurance AGENCY: Federal Aviation Administration (FAA), DOT. [[Page 73920

76 FR 40753 - NASA Advisory Council; Aeronautics Committee; Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-11

... strategy Verification and Validation of Flight Critical Systems planning update NASA Aeronautics systems analysis and strategic planning It is imperative that this meeting be held on this date to accommodate the... aeronautics community and other persons, research and technical information relevant to program planning...

76 FR 183 - NASA Advisory Council; Aeronautics Committee; Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-03

... NATIONAL AERONAUTICS AND SPACE ADMINISTRATION [Notice: (10-172)] NASA Advisory Council... the NASA Advisory Council. The meeting will be held for the purpose of soliciting from the aeronautics... 20546, (202) 358-0566, or [email protected]nasa.gov . SUPPLEMENTARY INFORMATION: The meeting will be open...

75 FR 54221 - Government/Industry Aeronautical Charting Forum Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-03

...) Aeronautical Charting Forum (ACF) to discuss informational content and design of aeronautical charts and related products, as well as instrument flight procedures development policy and design criteria. DATES: The ACF is separated into two distinct groups. The Instrument Procedures Group (IPG) will meet October...

76 FR 12211 - Government/Industry Aeronautical Charting Forum Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-04

...) Aeronautical Charting Forum (ACF) to discuss informational content and design of aeronautical charts and related products, as well as instrument flight procedures development policy and design criteria. DATES: The ACF is separated into two distinct groups. The Instrument Procedures Group (IPG) will meet April...

77 FR 50759 - Government/Industry Aeronautical Charting Forum Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-22

...) Aeronautical Charting Forum (ACF) to discuss informational content and design of aeronautical charts and related products, as well as instrument flight procedures development policy and design criteria. DATES: The ACF is separated into two distinct groups. The Instrument Procedures Group (IPG) will meet October...

A cumulative index to a continuing bibliography on aeronautical engineering

NASA Technical Reports Server (NTRS)

1986-01-01

This bibliography is a cumulative index to the abstracts contained in NASA-SP-7037(184) through NASA-SP-7037(195) of Aeronautical Engineering: A Continuing Bibliography. NASA SP-7037 and its supplements have been compiled through the cooperative efforts of the American Institute of Aeronautics and Astronautics (AIAA) and the National Aeronautics and Space Administration (NASA). This cumulative index includes subject, personal author, corporate source, foreign technology, contract, report number, and accession number indexes.

Aeronautical Engineering: A Continuing Bibliography With Indexes. Supplement 406

NASA Technical Reports Server (NTRS)

1999-01-01

This supplemental issue of Aeronautical Engineering, A Continuing Bibliography with Indexes (NASA/SP-1999-7037) lists reports, articles, and other documents recently announced in the NASA STI Database. The coverage includes documents on the engineering and theoretical aspects of design, construction, evaluation, testing, operation, and performance of aircraft (including aircraft engines) and associated components, equipment, and systems. It also includes research and development in aerodynamics, aeronautics, and ground support equipment for aeronautical vehicles. Each entry in the publication consists of a standard bibliographic citation accompanied, in most cases, by an abstract. Two indexes-subject and author are included after the abstract section.

Aeronautical Engineering: A Continuing Bibliography with Indexes. Supplement 413

NASA Technical Reports Server (NTRS)

2000-01-01

This supplemental issue of Aeronautical Engineering, A Continuing Bibliography with Indexes (NASA/SP-2000-7037) lists reports, articles, and other documents recently announced in the NASA STI Database. The coverage includes documents on the engineering and theoretical aspects of design, construction, evaluation, testing, operation, and performance of aircraft (including aircraft engines) and associated components, equipment, and systems. It also includes research and development in aerodynamics, aeronautics, and ground support equipment for aeronautical vehicles. Each entry in the publication consists of a standard bibliographic citation accompanied, in most cases, by an abstract. Two indexes-subject and author are included after the abstract section.

Aeronautical Engineering: A Continuing Bibliography with Indexes. Supplement 419

NASA Technical Reports Server (NTRS)

2000-01-01

This supplemental issue of Aeronautical Engineering, A Continuing Bibliography with Indexes (NASA/SP-2000-7037) lists reports, articles, and other documents recently announced in the NASA STI Database. The coverage includes documents on the engineering and theoretical aspects of design, construction, evaluation, testing, operation, and performance of aircraft (including aircraft engines) and associated components, equipment, and systems. It also includes research and development in aerodynamics, aeronautics, and ground support equipment for aeronautical vehicles. Each entry in the publication consists of a standard bibliographic citation accompanied, in most cases, by an abstract. Two indexes-subject and author are included after the abstract section.

Aeronautical Engineering: A Continuing Bibliography With Indexes. Supplement 404

NASA Technical Reports Server (NTRS)

1999-01-01

This supplemental issue of Aeronautical Engineering, A Continuing Bibliography with Indexes (NASA/SP-1999-7037) lists reports, articles, and other documents recently announced in the NASA STI Database. The coverage includes documents on the engineering and theoretical aspects of design, construction, evaluation, testing, operation, and performance of aircraft (including aircraft engines) and associated components, equipment, and systems. It also includes research and development in aerodynamics, aeronautics, and ground support equipment for aeronautical vehicles. Each entry in the publication consists of a standard bibliographic citation accompanied, in most cases, by an abstract. Two indexes-subject and author are included after the abstract section.

Aeronautical Engineering: A Continuing Bibliography with Indexes. Supplement 420

NASA Technical Reports Server (NTRS)

2000-01-01

This supplemental issue of Aeronautical Engineering, A Continuing Bibliography with Indexes (NASA/SP-2000-7037) lists reports, articles, and other documents recently announced in the NASA STI Database. The coverage includes documents on the engineering and theoretical aspects of design, construction, evaluation, testing, operation, and performance of aircraft (including aircraft engines) and associated components, equipment, and systems. It also includes research and development in aerodynamics, aeronautics, and ground support equipment for aeronautical vehicles. Each entry in the publication consists of a standard bibliographic citation accompanied, in most cases, by an abstract. Two indexes-subject and author are included after the abstract section.

Aeronautical Engineering: A Continuing Bibliography With Indexes. Supplement 418

NASA Technical Reports Server (NTRS)

2000-01-01

This supplemental issue of Aeronautical Engineering, A Continuing Bibliography with Indexes (NASA/SP-2000-7037) lists reports, articles, and other documents recently announced in the NASA STI Database. The coverage includes documents on the engineering and theoretical aspects of design, construction, evaluation, testing, operation, and performance of aircraft (including aircraft engines) and associated components, equipment, and systems. It also includes research and development in aerodynamics, aeronautics, and ground support equipment for aeronautical vehicles. Each entry in the publication consists of a standard bibliographic citation accompanied, in most cases, by an abstract. Two indexes-subject and author are included after the abstract section.

Aeronautical Engineering: A Continuing Bibliography with Indexes. Supplement 396

NASA Technical Reports Server (NTRS)

1999-01-01

This supplemental issue of Aeronautical Engineering, A Continuing Bibliography with Indexes (NASA/SP-1999-7037) lists reports, articles, and other documents recently announced in the NASA STI Database. The coverage includes documents on the engineering and theoretical aspects of design, construction, evaluation, testing, operation, and performance of aircraft (including aircraft engines) and associated components, equipment, and systems. It also includes research and development in aerodynamics, aeronautics, and ground support equipment for aeronautical vehicles. Each entry in the publication consists of a standard bibliographic citation accompanied, in most cases, by an abstract. Two indexes-subject and author are included after the abstract section.

Energetic ion leakage from foreshock transient cores

NASA Astrophysics Data System (ADS)

Liu, Terry Z.; Angelopoulos, Vassilis; Hietala, Heli

2017-07-01

Earth's foreshock is filled with backstreaming particles that can interact with the ambient solar wind and its discontinuities to form foreshock transients. Many foreshock transients have a core with low dynamic pressure that can significantly perturb the bow shock and the magnetosphere-ionosphere system. Foreshock transients have also been recently recognized as sites of particle acceleration, which may be important for seeding the parent shock with energetic particles. A relevant step of this seeding would be energetic ion leakage into the surrounding foreshock environment. On the other hand, such leakage would also suppress the energetic particle flux contrast across foreshock transients' boundaries masking their perceived contribution to ion energization. To further examine this hypothesis of ion leakage, we report on multipoint case studies of three foreshock transient events selected from a large database. The cases were selected to exemplify, in increasing complexity, the nature and consequences of energetic ion leakage. Ion energy dispersion, observed upstream and/or downstream of the foreshock transients, is explained with a simple, ballistic model of ions leaking from the foreshock transients. Larger energies are required for leaked ions to reach the spacecraft as the distance between the transient and spacecraft increases. Our model, which explains well the observed ion energy dispersion and velocity distributions, can also be used to reveal the shape of the foreshock transients in three dimensions. Our results suggest that ion leakage from foreshock transient cores needs to be accounted for both in statistical studies and in global models of ion acceleration under quasi-parallel foreshock conditions.

Lung protein leakage in feline septic shock.

PubMed

Schützer, K M; Larsson, A; Risberg, B; Falk, A

1993-06-01

The aim of the present study was to explore lung microvascular leakage of protein and water in a feline model of septic shock, using a double isotope technique with external gamma camera detection and gravimetric lung water measurements. The experiments were performed on artificially ventilated cats. One group of cats (n = 8) was given an infusion of live Escherichia coli bacteria, and another group (n = 5) served as a control group receiving saline. Plasma transferrin was radiolabeled in vivo with indium-113m-chloride, and erythrocytes were labeled with technetium-99m. The distribution of these isotopes in the lungs was continuously measured with a gamma camera. A normalized slope index (NSI) was calculated, indicative of the transferrin accumulation corrected for changes in local blood volume that reflect protein leakage. In the septic group there was a protein leakage after bacterial infusion, with a NSI of 39 x 10(-4) +/- 5 x 10(-4) min-1 (mean +/- SEM), and the PaO2 diminished from 21 +/- 1 to 9.5 +/- 1 kPa. In control cats a slight protein leakage with a NSI of 9 +/- 10(-4) +/- 2 x 10(-4) min-1 was detected, probably caused by the operative procedure, but PaO2 did not change. Wet-to-dry-weight ratios of postmortem lungs were not significantly different between the groups. It was concluded that an intravenous infusion of live E. coli bacteria induces a lung capillary protein leakage without increased lung water and a concomitantly disturbed gas exchange.(ABSTRACT TRUNCATED AT 250 WORDS)

Emerging Definition of Next-Generation of Aeronautical Communications

NASA Technical Reports Server (NTRS)

Kerczewski, Robert J.

2006-01-01

Aviation continues to experience rapid growth. In regions such as the United States and Europe air traffic congestion is constraining operations, leading to major new efforts to develop methodologies and infrastructures to enable continued aviation growth through transformational air traffic management systems. Such a transformation requires better communications linking airborne and ground-based elements. Technologies for next-generation communications, the required capacities, frequency spectrum of operation, network interconnectivity, and global interoperability are now receiving increased attention. A number of major planning and development efforts have taken place or are in process now to define the transformed airspace of the future. These activities include government and industry led efforts in the United States and Europe, and by international organizations. This paper will review the features, approaches, and activities of several representative planning and development efforts, and identify the emerging global consensus on requirements of next generation aeronautical communications systems for air traffic control.

Biomembrane Permeabilization: Statistics of Individual Leakage Events Harmonize the Interpretation of Vesicle Leakage.

PubMed

Braun, Stefan; Pokorná, Šárka; Šachl, Radek; Hof, Martin; Heerklotz, Heiko; Hoernke, Maria

2018-01-23

The mode of action of membrane-active molecules, such as antimicrobial, anticancer, cell penetrating, and fusion peptides and their synthetic mimics, transfection agents, drug permeation enhancers, and biological signaling molecules (e.g., quorum sensing), involves either the general or local destabilization of the target membrane or the formation of defined, rather stable pores. Some effects aim at killing the cell, while others need to be limited in space and time to avoid serious damage. Biological tests reveal translocation of compounds and cell death but do not provide a detailed, mechanistic, and quantitative understanding of the modes of action and their molecular basis. Model membrane studies of membrane leakage have been used for decades to tackle this issue, but their interpretation in terms of biology has remained challenging and often quite limited. Here we compare two recent, powerful protocols to study model membrane leakage: the microscopic detection of dye influx into giant liposomes and time-correlated single photon counting experiments to characterize dye efflux from large unilamellar vesicles. A statistical treatment of both data sets does not only harmonize apparent discrepancies but also makes us aware of principal issues that have been confusing the interpretation of model membrane leakage data so far. Moreover, our study reveals a fundamental difference between nano- and microscale systems that needs to be taken into account when conclusions about microscale objects, such as cells, are drawn from nanoscale models.

47 CFR 76.1706 - Signal leakage logs and repair records.

Code of Federal Regulations, 2010 CFR

2010-10-01

... the probable cause of the leakage. The log shall be kept on file for a period of two years and shall... 47 Telecommunication 4 2010-10-01 2010-10-01 false Signal leakage logs and repair records. 76.1706... leakage logs and repair records. Cable operators shall maintain a log showing the date and location of...

47 CFR 76.1706 - Signal leakage logs and repair records.

Code of Federal Regulations, 2011 CFR

2011-10-01

... the probable cause of the leakage. The log shall be kept on file for a period of two years and shall... 47 Telecommunication 4 2011-10-01 2011-10-01 false Signal leakage logs and repair records. 76.1706... leakage logs and repair records. Cable operators shall maintain a log showing the date and location of...

Hide and Seek: Exploiting and Hardening Leakage-Resilient Code Randomization

DTIC Science & Technology

2016-05-30

Hide and Seek: Exploiting and Hardening Leakage -Resilient Code Randomization Robert Rudd MIT Lincoln Laboratory Thomas Hobson MIT Lincoln Laboratory...Irvine Ahmad-Reza Sadeghi TU Darmstadt Hamed Okhravi MIT Lincoln Laboratory Abstract Information leakage vulnerabilities can allow adversaries to...bypass mitigations based on code randomization. This discovery motivates numerous techniques that diminish direct and indirect information leakage : (i

Hide and Seek: Exploiting and Hardening Leakage-Resilient Code Randomization

DTIC Science & Technology

2016-03-30

Hide and Seek: Exploiting and Hardening Leakage -Resilient Code Randomization Robert Rudd MIT Lincoln Laboratory Thomas Hobson MIT Lincoln Laboratory...Irvine Ahmad-Reza Sadeghi TU Darmstadt Hamed Okhravi MIT Lincoln Laboratory Abstract Information leakage vulnerabilities can allow adversaries to...bypass mitigations based on code randomization. This discovery motivates numerous techniques that diminish direct and indirect information leakage : (i

An Experimental Characterization of Tip Leakage Flows and Corresponding Effects on Multistage Compressor Performance

NASA Astrophysics Data System (ADS)

Berdanier, Reid Adam

measurements collected at these part-speed and off-design conditions provides a unique data set for calibrating computational models and predictive algorithms. Further investigations with detailed steady total pressure traverses provide additional insight to tip leakage flow effects on stator performance. A series of data on the 100% corrected speedline further characterize the tip leakage flow using time-resolved measurements from a combination of instrumentation techniques. An array of high-frequency-response piezoresistive pressure transducers installed over the rotors allows quantification of tip leakage flow trajectories. These data, along with measurements from a fast-response total pressure probe downstream of the rotors, evaluate the development of tip leakage flows and assess the corresponding effects of upstream stator wakes. Finally, thermal anemometry measurements collected using the single slanted hot-wire technique evaluate three-dimensional velocity components throughout the compressor. These data facilitate calculations of several flow metrics, including a blockage parameter and phase-locked streamwise vorticity.

Aeronautical engineering. A continuing bibliography with indexes, supplement 127, October 1980

NASA Technical Reports Server (NTRS)

1980-01-01

A bibliography containing 431 abstracts addressing various topics in aeronautical engineering is given. The coverage includes engineering and theoretical aspects of design. construction, evaluation, testing, operation, and performance of aircraft (including aircraft engines) and associated components, equipment, and systems. It also includes research and development in aerodynamics, aeronautics, and ground support equipment for aeronautical vehicles.

Relevance of Micro-leakage to Orthodontic Bonding - a Review

PubMed Central

M, Karandish

2016-01-01

As it is seen, by passing the evolutionary process of banding of orthodontic attachments to the bonding ones, orthodontics have witnessed many developments, such as application of new adhesives, optimized base designs, new bracket materials, curing methods and more efficient primers. The studies often address the morphological, micro-leakage, and shear bond tests to evaluate bond efficacy. Among studies endeavored to develop the bond strength of brackets, some observed the reduction of micro-leakage of bracket-adhesive and enamel-adhesive interfaces. Owing to the importance of micro-leakage in orthodontics, this study aimed at reviewing the micro-leakage values directly relevant to the enamel decay and debonding of the brackets. To reach the best bond strength, the researchers tried to design different studies to evaluate the effect of variables and prevent any possible side effects in clinical situations. It is noticed that most studies have mainly focused on adhesives, enamel preparation and methods of curing which are discussed in this review. The literature was reviewed by searching databases, using micro-leakage and orthodontic bonding as the keywords . Having found the relevant studies, the researchers entered them into the database. After reviewing numerous studies conducted in this field, the type of adhesive or curing method was not found to have determinative role in the value of micro-leakage although more standardized studies are needed. PMID:28959751

University research in aeronautics

NASA Technical Reports Server (NTRS)

Duberg, J. E.

1975-01-01

The contributions which universities can make to aeronautical research projects are discussed. The activities of several facilities are presented to show the effectiveness of the educational and research programs. Reference is made to the Intergovernmental Personnel Act of 1970 which permits an exchange of federal agency personnel with state and local governments and with public and private higher education schools.

Astronautics and Aeronautics: A Chronology, 2001-2005

NASA Technical Reports Server (NTRS)

Ivey, William Noel; Lewis, Marieke

2010-01-01

This report is a chronological compilation of narrative summaries of news reports and government documents highlighting significant events and developments in U.S. and foreign aeronautics and astronautics. It covers the years 2001 through 2005. These summaries provide a day-by-day recounting of major activities, such as administrative developments, awards, launches, scientific discoveries, corporate and government research results, and other events in countries with aeronautics and astronautics programs. Researchers used the archives and files housed in the NASA History Division, as well as reports and databases on the NASA Web site.

Astronautics and Aeronautics: A Chronology, 1996-2000

NASA Technical Reports Server (NTRS)

Lewis, Marieke; Swanson, Ryan

2009-01-01

This report is a chronological compilation of narrative summaries of news reports and government documents highlighting significant events and developments in United States and foreign aeronautics and astronautics. It covers the years 1996 through 2000. These summaries provide a day-by-day recounting of major activities, such as administrative developments, awards, launches, scientific discoveries, corporate and government research results, and other events in countries with aeronautics and astronautics programs. Researchers used the archives and files housed in the NASA History Division, as well as reports and databases on the NASA Web site.

Atlantic multi-decadal oscillation covaries with Agulhas leakage

PubMed Central

Biastoch, Arne; Durgadoo, Jonathan V.; Morrison, Adele K.; van Sebille, Erik; Weijer, Wilbert; Griffies, Stephen M.

2015-01-01

The interoceanic transfer of seawater between the Indian Ocean and the Atlantic, ‘Agulhas leakage', forms a choke point for the overturning circulation in the global ocean. Here, by combining output from a series of high-resolution ocean and climate models with in situ and satellite observations, we construct a time series of Agulhas leakage for the period 1870–2014. The time series demonstrates the impact of Southern Hemisphere westerlies on decadal timescales. Agulhas leakage shows a correlation with the Atlantic Multi-decadal Oscillation on multi-decadal timescales; the former leading by 15 years. This is relevant for climate in the North Atlantic. PMID:26656850

Toward Understanding Tip Leakage Flows in Small Compressor Cores Including Stator Leakage Flow

NASA Technical Reports Server (NTRS)

Berdanier, Reid A.; Key, Nicole L.

2017-01-01

The focus of this work was to provide additional data to supplement the work reported in NASA/CR-2015-218868 (Berdanier and Key, 2015b). The aim of that project was to characterize the fundamental flow physics and the overall performance effects due to increased rotor tip clearance heights in axial compressors. Data have been collected in the three-stage axial research compressor at Purdue University with a specific focus on analyzing the multistage effects resulting from the tip leakage flow. Three separate rotor tip clearances were studied with nominal tip clearance gaps of 1.5 percent, 3.0 percent, and 4.0 percent based on a constant annulus height. Overall compressor performance was previously investigated at four corrected speedlines (100 percent, 90 percent, 80 percent, and 68 percent) for each of the three tip clearance configurations. This study extends the previously published results to include detailed steady and time-resolved pressure data at two loading conditions, nominal loading (NL) and high loading (HL), on the 100 percent corrected speedline for the intermediate clearance level (3.0 percent). Steady detailed radial traverses of total pressure at the exit of each stator row are supported by flow visualization techniques to identify regions of flow recirculation and separation. Furthermore, detailed radial traverses of time-resolved total pressures at the exit of each rotor row have been measured with a fast-response pressure probe. These data were combined with existing three-component velocity measurements to identify a novel technique for calculating blockage in a multistage compressor. Time-resolved static pressure measurements have been collected over the rotor tips for all rotors with each of the three tip clearance configurations for up to five loading conditions along the 100 percent corrected speedline using fast-response piezoresistive pressure sensors. These time-resolved static pressure measurements reveal new knowledge about the

Evaluation of the White Test for the Intraoperative Detection of Bile Leakage

PubMed Central

Leelawat, Kawin; Chaiyabutr, Kittipong; Subwongcharoen, Somboon; Treepongkaruna, Sa-ad

2012-01-01

We assess whether the White test is better than the conventional bile leakage test for the intraoperative detection of bile leakage in hepatectomized patients. This study included 30 patients who received elective liver resection. Both the conventional bile leakage test (injecting an isotonic sodium chloride solution through the cystic duct) and the White test (injecting a fat emulsion solution through the cystic duct) were carried out in the same patients. The detection of bile leakage was compared between the conventional method and the White test. A bile leak was demonstrated in 8 patients (26.7%) by the conventional method and in 19 patients (63.3%) by the White test. In addition, the White test detected a significantly higher number of bile leakage sites compared with the conventional method (Wilcoxon signed-rank test; P < 0.001). The White test is better than the conventional test for the intraoperative detection of bile leakage. Based on our study, we recommend that surgeons investigating bile leakage sites during liver resections should use the White test instead of the conventional bile leakage test. PMID:22547901

Evaluation of the white test for the intraoperative detection of bile leakage.

PubMed

Leelawat, Kawin; Chaiyabutr, Kittipong; Subwongcharoen, Somboon; Treepongkaruna, Sa-Ad

2012-01-01

We assess whether the White test is better than the conventional bile leakage test for the intraoperative detection of bile leakage in hepatectomized patients. This study included 30 patients who received elective liver resection. Both the conventional bile leakage test (injecting an isotonic sodium chloride solution through the cystic duct) and the White test (injecting a fat emulsion solution through the cystic duct) were carried out in the same patients. The detection of bile leakage was compared between the conventional method and the White test. A bile leak was demonstrated in 8 patients (26.7%) by the conventional method and in 19 patients (63.3%) by the White test. In addition, the White test detected a significantly higher number of bile leakage sites compared with the conventional method (Wilcoxon signed-rank test; P < 0.001). The White test is better than the conventional test for the intraoperative detection of bile leakage. Based on our study, we recommend that surgeons investigating bile leakage sites during liver resections should use the White test instead of the conventional bile leakage test.

Cyber Technology for Materials and Structures in Aeronautics and Aerospace

NASA Technical Reports Server (NTRS)

Pipes, R. Byron

2002-01-01

The evolution of composites applications in aeronautics from 1970 to the present is discussed. The barriers and challenges to economic application and to certification are presented and recommendations for accelerated development are outlined. The potential benefits of emerging technologies to aeronautics and their foundation in composite materials are described and the resulting benefits in vehicle take off gross weight are quantified. Finally, a 21st century vision for aeronautics in which human mobility is increased by an order of magnitude is articulated.

Aeronautics and Space Report of the President: 1977 Activities.

ERIC Educational Resources Information Center

National Aeronautics and Space Administration, Washington, DC.

The national programs in aeronautics and space made steady progress in 1977 toward their long-term objectives. In aeronautics the goals were improved performance, energy efficiency, and safety in aircraft. In space the goals were: (1) better remote sensing systems to generate more sophisticated information about the Earth's environment; (2)…

The predicament of aeronautical engineering education and what we can do about it

NASA Technical Reports Server (NTRS)

Bryson, A. E., Jr.

1975-01-01

An analysis of the aeronautical engineering situation and the relationship to the U.S. aircraft industry is presented. Some of the problems encountered in undergraduate aeronautical engineering education are explained. A reorganization of the educational structure for aeronautical engineering is proposed. The human factors aspect of aeronautical engineering discipline is described.

47 CFR 76.611 - Cable television basic signal leakage performance criteria.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 4 2010-10-01 2010-10-01 false Cable television basic signal leakage... television basic signal leakage performance criteria. (a) No cable television system shall commence or... one of the following cable television basic signal leakage performance criteria: (1) prior to carriage...

Evaluation of particulate filtering respirators using inward leakage (IL) or total inward leakage (TIL) testing--Korean experience.

PubMed

Han, Don-Hee; Lee, Jinheon

2005-10-01

Korean certification regulation for particulate filtering respirators requires inward leakage (IL) or total inward leakage (TIL) testing according to European Standard EN 13274-1, and the standard levels of compliance are similar to those of the European Standard. This study was conducted to evaluate particulate filtering respirators being commercially used in the Korean market using an IL or TIL test and the validity of standard level in Korea. Three half masks and 10 filtering facepieces (two top class, four 1st class and four 2nd class)-a total of 13 brand name respirators-were selected for the test with panels of 10 subjects. Each subject was classified with nine facial dimension grid squares in accordance with face length and lip length. IL or TIL testing was conducted at the laboratory of the 3M Innovation Center in which the experimental instruments and systems were established in compliance with European standards. The testing procedure followed EN 13274-1 (2001). As expected, leakages of half masks were less than those of filtering facepieces and the latter were significantly different among brands. TILs of the 1st class filtering facepieces were found to be much more than those of the 2nd class and the result may cause a wearer to get confused when selecting a mask. The main route leakage for filtering facepieces may not be the filter medium but the face seal. Therefore, it is necessary to develop well-fitting filtering facepieces for Koreans. Because leakages were significantly different for different facial dimensions, a defined test panel for IL or TIL testing according to country or race should be developed. A more precise method to demonstrate fit, for example, fit testing such as in the US regulations, will be needed before IL or TIL testing or when selecting a respirator. Another finding implies that geometric mean of five exercises for IL or TIL may be better than arithmetic mean to establish a standard individual subject mean.

[Reflection on the present study of anastomotic leakage after colorectal surgery].

PubMed

Wu, Zhouqiao; Shi, Jinyao; Li, Ziyu; Ji, Jiafu

Anastomotic leakage is one of the most serious complications of colorectal surgery. Despite progress in available surgical techniques, the morbidity associated with anastomotic leakage remains high. In this review, we summarize the current clinical status of this complication, the problems it causes, and relevant research achievements. To date, a lack of consensus regarding the diagnosis of anastomotic leakage has resulted in varying rates of diagnosis across countries and regions worldwide. Accurately predicting the occurrence of anastomotic leakage using the established risk factors and preoperative scoring systems remains difficult. Many of the described preventive measures, including defunctioning stoma creation, positive air leak testing, and use of effective tissue adhesives, remain controversial; more evidence-based medical information is urgently needed. Delayed diagnoses of anastomotic leakage also remain common in clinical practice. To prevent catastrophic outcomes, such as reoperations or deaths, early diagnosis is critically important. Parameters local to the area of the anastomosis may facilitate early detection of leakage, but their effectiveness is subject to clinical validation. Lastly, the pathological etiology of anastomotic leakage remains to be determined, and its elucidation may inspire innovative interventions that solve this critical surgical complication.

76 FR 53530 - Government/Industry Aeronautical Charting Forum Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-26

... Charting Forum Meeting AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of public meeting...) Aeronautical Charting Forum (ACF) to discuss informational content and design of aeronautical charts and... Charting Forum to be held from October 25 through October 27, 2011, from 8:30 a.m. to 5 p.m. at FAA AeroNav...

The SSME seal test program: Leakage tests for helically-grooved seals

NASA Technical Reports Server (NTRS)

Childs, D. W.

1983-01-01

Helically grooved annular seal configurations were tested in highly turbulent flow to determine if reduced leakage and enhanced stability would result from the pumping action of the seal. It was found that: (1) leakage of a helically grooved seals decreases with running speed; (2) leakage reduction due to increased running speed is greater at lower values of R sub a; (3) an asymptote for leakage reduction is indicated with increasing running speed; (4) leakage is reduced by reducing the ridge (minimum) and average clearances; (5) leakage increases with increasing pitch angles and with increasing groove depth. Plain seals with smooth rotors and stators will leak more than a helically grooved seal. It was also found that plain seals with a rough rotor and a rough stator leak less than a properly designed helically grooved seal. A properly designed helically grooved seal consumes at least twice as much power as a conventional annular seal.

Reshaping NASA's Aeronautics Program

NASA Technical Reports Server (NTRS)

Liang, Anita D.

2007-01-01

We will dedicate ourselves to the mastery and intellectual stewardship of the core competencies of Aeronautics for the Nation in all flight regimes. We will focus our research in areas that are appropriate to NASA's unique capabilities. we will directly address the R&D needs of the Next Generation Air Transportation System (NGATS) in partnership with the member agencies of the Joint Planning and development Office (JPDO).

Advanced Civilian Aeronautical Concepts

NASA Technical Reports Server (NTRS)

Bushnell, Dennis M.

1996-01-01

Paper discusses alternatives to currently deployed systems which could provide revolutionary improvements in metrics applicable to civilian aeronautics. Specific missions addressed include subsonic transports, supersonic transports and personal aircraft. These alternative systems and concepts are enabled by recent and envisaged advancements in electronics, communications, computing and Designer Fluid Mechanics in conjunction with a design approach employing extensive synergistic interactions between propulsion, aerodynamics and structures.

Aeronautic Instruments. Section II : Altitude Instruments

NASA Technical Reports Server (NTRS)

Mears, A H; Henrickson, H B; Brombacher, W G

1923-01-01

This report is Section two of a series of reports on aeronautic instruments (Technical Report nos. 125 to 132, inclusive). This section discusses briefly barometric altitude determinations, and describes in detail the principal types of altimeters and barographs used in aeronautics during the recent war. This is followed by a discussion of performance requirements for such instruments and an account of the methods of testing developed by the Bureau of Standards. The report concludes with a brief account of the results of recent investigations. For accurate measurements of altitude, reference must also be made to thermometer readings of atmospheric temperature, since the altitude is not fixed by atmospheric pressure alone. This matter is discussed in connection with barometric altitude determination.

Future Aeronautical Communication Infrastructure Technology Investigation

NASA Technical Reports Server (NTRS)

Gilbert, Tricia; Jin, Jenny; Bergerm Jason; Henriksen, Steven

2008-01-01

This National Aeronautics and Space Administration (NASA) Contractor Report summarizes and documents the work performed to investigate technologies that could support long-term aeronautical mobile communications operating concepts for air traffic management (ATM) in the timeframe of 2020 and beyond, and includes the associated findings and recommendations made by ITT Corporation and NASA Glenn Research Center to the Federal Aviation Administration (FAA). The work was completed as the final phase of a multiyear NASA contract in support of the Future Communication Study (FCS), a cooperative research and development program of the United States FAA, NASA, and EUROCONTROL. This final report focuses on an assessment of final five candidate technologies, and also provides an overview of the entire technology assessment process, including final recommendations.

Fractal modeling of fluidic leakage through metal sealing surfaces

NASA Astrophysics Data System (ADS)

Zhang, Qiang; Chen, Xiaoqian; Huang, Yiyong; Chen, Yong

2018-04-01

This paper investigates the fluidic leak rate through metal sealing surfaces by developing fractal models for the contact process and leakage process. An improved model is established to describe the seal-contact interface of two metal rough surface. The contact model divides the deformed regions by classifying the asperities of different characteristic lengths into the elastic, elastic-plastic and plastic regimes. Using the improved contact model, the leakage channel under the contact surface is mathematically modeled based on the fractal theory. The leakage model obtains the leak rate using the fluid transport theory in porous media, considering that the pores-forming percolation channels can be treated as a combination of filled tortuous capillaries. The effects of fractal structure, surface material and gasket size on the contact process and leakage process are analyzed through numerical simulations for sealed ring gaskets.

75 FR 11225 - Government/Industry Aeronautical Charting Forum Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-10

... Charting Forum Meeting AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of public meeting...) Government/Industry Aeronautical Charting Forum (ACF 10-01) to discuss informational content and design of... Aeronautical Charting Forum to be held from April 27 through April 29, 2010 from 8:30 a.m. to 5 p.m. at the Air...

Aeronautical engineering: A cumulative index to a continuing bibliography (supplement 248)

NASA Technical Reports Server (NTRS)

1990-01-01

This publication is a cumulative index to the abstracts contained in Supplements 236 through 247 of Aeronautical Engineering: A Continuing Bibliography. The bibliographic series is compiled through the cooperative efforts of the American Institute of Aeronautics and Astronautics (AIAA) and the National Aeronautics and Space Administration (NASA). Seven indexes are included -- subject, personal author, corporate source, foreign technology, contract number, report number and accession number.

Aeronautical engineering: A cumulative index to a continuing bibliography (supplement 235)

NASA Technical Reports Server (NTRS)

1989-01-01

This publication is a cummulative index to the abstracts contained in Supplements 223 through 234 of Aeronautical Engineering: A Continuing Bibliography. The bibliographic series is compiled through the cooperative efforts of the American Institute of Aeronautics and Astronautics (AIAA) and the National Aeronautics and Space Administration (NASA). Seven indexes are included -- subject, personal author, corporate source, foreign technology, contract number, report number and accession number.

Aeronautical engineering: A cumulative index to a continuing bibliography (supplement 274)

NASA Technical Reports Server (NTRS)

1992-01-01

This publication is a cumulative index to the abstracts contained in supplements 262 through 273 of Aeronautical Engineering: A Continuing Bibliography. The bibliographic series is compiled through the cooperative efforts of the American Institute of Aeronautics and Astronautics (AIAA) and the National Aeronautics and Space Administration (NASA). Seven indexes are included: subject, personal author, corporate source, foreign technology, contract number, report number, and accession number.

Aeronautical engineering: A cumulative index to a continuing bibliography (supplement 261)

NASA Technical Reports Server (NTRS)

1991-01-01

This publication is a cummulative index to the abstracts contained in Supplements 249 through 260 of Aeronautical Engineering: A Continuing Bibliography. The bibliographic series is compiled through the cooperative efforts of the American Institute of Aeronautics and Astronautics (AIAA) and the National Aeronautics and Space Administration (NASA). Seven indexes are included -- subject, personal author, corporate source, foreign technology, contract number, report number and accession number.

Aeronautical engineering: A cumulative index to a continuing bibliography (supplement 287)

NASA Technical Reports Server (NTRS)

1993-01-01

This publication is a cummulative index to the abstracts contained in Supplements 275 through 286 of Aeronautical Engineering: A Continuing Bibliography. The bibliographic series is compiled through the cooperative efforts of the American Institute of Aeronautics and Astronautics (AIAA) and the National Aeronautics and Space Administration (NASA). Seven indexes are included -- subject, personal author, corporate source, foreign technology, contract number, report number and accession number.

Study on detecting leachate leakage of municipal solid waste landfill site.

PubMed

Liu, Jiangang; Cao, Xianxian; Ai, Yingbo; Zhou, Dongdong; Han, Qiting

2015-06-01

The article studies the detection of the leakage passage of leachate in a waste landfill dam. The leachate of waste landfill has its own features, like high conductivity, high chroma and an increasing temperature, also, the horizontal flow velocity of groundwater on the leakage site increases. This article proposes a comprehensive tracing method to identify the leakage site of an impermeable membrane by using these features. This method has been applied to determine two leakage sites of the Yahu municipal solid waste landfill site in Pingshan District, Shenzhen, China, which shows that there are two leachate leakage passages in the waste landfill dam A between NZK-2 and NZK-3, and between NZK-6 and NZK-7. © The Author(s) 2015.

Technology Solutions Case Study: Predicting Envelope Leakage in Attached Dwellings

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

2013-11-01

The most common method of measuring air leakage is to perform single (or solo) blower door pressurization and/or depressurization test. In detached housing, the single blower door test measures leakage to the outside. In attached housing, however, this “solo” test method measures both air leakage to the outside and air leakage between adjacent units through common surfaces. In an attempt to create a simplified tool for predicting leakage to the outside, Building America team Consortium for Advanced Residential Buildings (CARB) performed a preliminary statistical analysis on blower door test results from 112 attached dwelling units in four apartment complexes. Althoughmore » the subject data set is limited in size and variety, the preliminary analyses suggest significant predictors are present and support the development of a predictive model. Further data collection is underway to create a more robust prediction tool for use across different construction types, climate zones, and unit configurations.« less

Aeronautics Technology Possibilities for 2000: Report of a workshop

NASA Technical Reports Server (NTRS)

1984-01-01

The potential of aeronautical research and technology (R&T) development, which could provide the basis for facility planning and long range guidance of R&T programs and could establish justification for support of aeronautical research and technology was studied. The projections served specific purposes: (1) to provide a base for research and future facilities needed to support the projected technologies, and development advanced vehicles; (2) to provide insight on the possible state of the art in aeronautical technology by the year 2000 for civil and military planners of air vehicles and systems. Topics discussed include: aerodynamics; propulsion; structures; materials; guidance, navigation and control; computer and information technology; human factors; and systems integration.

Aeronautical Engineering: A Continuing Bibliography With Indexes. Supplement 398

NASA Technical Reports Server (NTRS)

1999-01-01

This supplemental issue of Aeronautical Engineering lists reports, articles, and other documents recently announced in the NASA STI Database. The coverage includes documents on the engineering and theoretical aspects of design, construction, evaluation, testing, operation, and performance of aircraft (including aircraft engines) and associated components, equipment, and systems. It also includes research and development in aerodynamics, aeronautics, and ground support equipment for aeronautical vehicles. Each entry in the publication consists of a standard bibliographic citation accompanied, in most cases, by an abstract. The NASA CASI price code table, addresses of organizations, and document availability information are included before the abstract section. Two indexes - subject and author are included after the abstract section.

NASA's Role in Aeronautics: A Workshop. Volume 7: Background papers

NASA Technical Reports Server (NTRS)

1981-01-01

The nature and implications of the current state of U.S. aviation in a world setting are examined as well as their significance for NASA's role in the nation's aeronautical future. The outlook for the 1980's is examined from the point of view of legislation, economics and finance; petroleum; manpower, metallic materials, general aviation; military aviation; transport aircraft developments; and helicopters. Possible NASA assistance to DOD and the FAA is examined and the evolution of NACA and NASA in aeronautics and of NASA's aeronautics capabilities are described.

Field size dependent mapping of medical linear accelerator radiation leakage

NASA Astrophysics Data System (ADS)

Vũ Bezin, Jérémi; Veres, Attila; Lefkopoulos, Dimitri; Chavaudra, Jean; Deutsch, Eric; de Vathaire, Florent; Diallo, Ibrahima

2015-03-01

The purpose of this study was to investigate the suitability of a graphics library based model for the assessment of linear accelerator radiation leakage. Transmission through the shielding elements was evaluated using the build-up factor corrected exponential attenuation law and the contribution from the electron guide was estimated using the approximation of a linear isotropic radioactive source. Model parameters were estimated by a fitting series of thermoluminescent dosimeter leakage measurements, achieved up to 100 cm from the beam central axis along three directions. The distribution of leakage data at the patient plane reflected the architecture of the shielding elements. Thus, the maximum leakage dose was found under the collimator when only one jaw shielded the primary beam and was about 0.08% of the dose at isocentre. Overall, we observe that the main contributor to leakage dose according to our model was the electron beam guide. Concerning the discrepancies between the measurements used to calibrate the model and the calculations from the model, the average difference was about 7%. Finally, graphics library modelling is a readily and suitable way to estimate leakage dose distribution on a personal computer. Such data could be useful for dosimetric evaluations in late effect studies.

NASA's K/Ka-Band Broadband Aeronautical Terminal for Duplex Satellite Video Communications

NASA Technical Reports Server (NTRS)

Densmore, A.; Agan, M.

1994-01-01

JPL has recently begun the development of a Broadband Aeronautical Terminal (BAT) for duplex video satellite communications on commercial or business class aircraft. The BAT is designed for use with NASA's K/Ka-band Advanced Communications Technology Satellite (ACTS). The BAT system will provide the systems and technology groundwork for an eventual commercial K/Ka-band aeronautical satellite communication system. With industry/government partnerships, three main goals will be addressed by the BAT task: 1) develop, characterize and demonstrate the performance of an ACTS based high data rate aeronautical communications system; 2) assess the performance of current video compression algorithms in an aeronautical satellite communication link; and 3) characterize the propagation effects of the K/Ka-band channel for aeronautical communications.

A cumulative index to Aeronautical Engineering, a continuing bibliography, supplement 105

NASA Technical Reports Server (NTRS)

1979-01-01

This bibliography is a cumulative index to the abstracts contained in NASA SP-7037 (93) through NASA SP-7037 (104) of Aeronautical Engineering: A Continuing Bibliography. NASA SP-7037 and its supplements were compiled through the cooperative efforts of the American Institute of Aeronautics and Astronautics (AIAA) and the National Aeronautics and Space Administration (NASA). This cumulative index includes subject, personal author, corporate source, contract, and report number indexes.

Aeronautical engineering: A cumulative index to a continuing bibliography (supplement 325)

NASA Technical Reports Server (NTRS)

1995-01-01

This publication is a cumulative index to the abstracts contained in NASA SP-7037 supplements 313 through 324 of Aeronautical Engineering: A Continuing Bibliography. The bibliographic series is compiled through the cooperative efforts of the American Institute of Aeronautics and Astronautics (AIAA) and the National Aeronautics and Space Administration (NASA). This Cumulative index includes: a subject, personal author, corporate source, foreign technology, contract number, report number, and accession number.

A cumulative index to Aeronautical Engineering: A special bibliography, January 1976

NASA Technical Reports Server (NTRS)

1976-01-01

This publication is a cumulative index to the abstracts contained in NASA SP-7037 (54) through NASA SP-7037 (65) of Aeronautical Engineering: A Special Bibliography. NASA SP-7037 and its supplements have been compiled through the cooperative efforts of the American Institute of Aeronautics and Astronautics (AIAA) and the National Aeronautics and Space Administration (NASA). This cumulative index includes subject, personal author, corporate source, contract, and report number indexes.

Radiation leakage dose from Elekta electron collimation system

PubMed Central

Hogstrom, Kenneth R.; Carver, Robert L.

2016-01-01

This study provided baseline data required for a greater project, whose objective was to design a new Elekta electron collimation system having significantly lighter electron applicators with equally low out‐of field leakage dose. Specifically, off‐axis dose profiles for the electron collimation system of our uniquely configured Elekta Infinity accelerator with the MLCi2 treatment head were measured and calculated for two primary purposes: 1) to evaluate and document the out‐of‐field leakage dose in the patient plane and 2) to validate the dose distributions calculated using a BEAMnrc Monte Carlo (MC) model for out‐of‐field dose profiles. Off‐axis dose profiles were measured in a water phantom at 100 cm SSD for 1 and 2 cm depths along the in‐plane, cross‐plane, and both diagonal axes using a cylindrical ionization chamber with the 10×10 and 20×20 cm2 applicators and 7, 13, and 20 MeV beams. Dose distributions were calculated using a previously developed BEAMnrc MC model of the Elekta Infinity accelerator for the same beam energies and applicator sizes and compared with measurements. Measured results showed that the in‐field beam flatness met our acceptance criteria (±3% on major and ±4% on diagonal axes) and that out‐of‐field mean and maximum percent leakage doses in the patient plane met acceptance criteria as specified by the International Electrotechnical Commission (IEC). Cross‐plane out‐of‐field dose profiles showed greater leakage dose than in‐plane profiles, attributed to the curved edges of the upper X‐ray jaws and multileaf collimator. Mean leakage doses increased with beam energy, being 0.93% and 0.85% of maximum central axis dose for the 10×10 and 20×20 cm2 applicators, respectively, at 20 MeV. MC calculations predicted the measured dose to within 0.1% in most profiles outside the radiation field; however, excluding modeling of nontrimmer applicator components led to calculations exceeding measured data by as

78 FR 10247 - Public Notice for Waiver of Aeronautical Land-Use Assurance

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-13

... proposal to change a portion of airport land from aeronautical use to non-aeronautical use and to authorize... Aeronautical Land-Use Assurance AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of intent of... now considered excess land not beneficial for future airport use. Proceeds from the sale of the land...

78 FR 22595 - Public Notice for Waiver of Aeronautical Land-Use Assurance

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-16

... Administration (FAA) is considering a proposal to change a portion of airport land from aeronautical use to non... Aeronautical Land-Use Assurance AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of intent of... modifying the land-use assurance that requires the property to be used for an aeronautical purpose. The...

Management and prevention of chylous leakage after laparoscopic lymphadenectomy.

PubMed

Han, L-P; Zhang, H-M; Abha, H-D; Liu, T; Zhang, X-P

2014-01-01

To investigate the development and management of chylous leakage after laparoscopic retroperitoneal lymphadenectomy. From July 2006 to September 2013, 13 cases of chylous leakage after the laparoscopic lymphadenectomy (6 cases of renal cell carcinoma, 4 cases of gastric cancer, 2 cases of ovarian cancer, 1 case of endometrial cancer) were studied to analyze the occurrence, development and management of chylous leakage. In 3 cases (2 cases of renal cell carcinoma, 1 case of gastric cancer) massive amount of milky fluid drainage was be seen after the first two days post operation. Dietary intervention, TPN (total parenteral nutrition), somatostatin therapy, maintenance of continuous drainage helped to successfully manage the condition in about 1 month duration. In the remaining 10 cases, chylous leakage appeared after restoring normal diet. Managed with changes in diet and maintenance of unobstructed drainage, they were cured in about 2 weeks after treatment. There was significant reduction in drain output, ultrasonography did not reveal presence of free fluid collection in abdomen, and the patients were in good condition without signs and symptoms of infections. Chylous leakage is a rare complication of retroperitoneal lymph node dissection. Surgeons should be familiar with laparoscopic techniques, relevant anatomy and be aware of the fact that the effect of CO2 pressure and use of ultrasonic knife to occlude the lymphatic vessel can transiently block the leakage making the surgeon overlook them. Routine placement of indwelling drainage tube, immediate diagnosis, dietary modification, TPN, somatostatin and drainage are the modalities of conservative management.

Simulation and experimental research of heat leakage of cryogenic transfer lines

NASA Astrophysics Data System (ADS)

Deng, B. C.; Xie, X. J.; Pan, W.; Jiang, R. X.; Li, J.; Yang, S. Q.; Li, Q.

2017-12-01

The heat leakage of cryogenic transfer lines directly influences the performance of large-scale helium refrigerator. In this paper, a thermal model of cryogenic transfer line considering numerical simulation of support coupled with MLI was established. To validate the model, test platform of cryogenic transfer lines with the merits of disassembly outer pipe and changeable easily multi-layer insulation has been built. The experimental results of heat leakage through overall length of cryogenic transfer lines, support and multi-layer insulation were obtained. The heat leakages of multi-layer insulation, a support and the overall leakage are 1.02 W/m, 0.44 W and 1.46 W/m from experimental data, respectively. The difference of heat leakage of MLI between experiment and simulation were less than 5%. The temperature distribution of support and MLI obtained in presented model in good agreement with experimental data. It is expected to reduce the overall heat leakage of cryogenic transfer lines further by optimizing structure of support based on the above thermal model and test platform in this paper.

78 FR 38090 - Public Notice for Waiver of Aeronautical Land-Use Assurance

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-25

... a proposal to change a 0.747-acre portion of airport land from aeronautical use to non-aeronautical... for aeronautical use and sale includes a 0.346-acre portion of Parcel G (110.55 total acres) and 0.401... the Third Principal Meridian, Grundy County, Illinois, with bearings and grid distances referenced to...

Aeronautical Engineering: A Continuing Bibliography with Indexes. SUPPL-422

NASA Technical Reports Server (NTRS)

2000-01-01

This report lists reports, articles and other documents recently announced in the NASA STI Database. The coverage includes documents on the engineering and theoretical aspects of design, construction, evaluation, testing, operation, and performance of aircraft (including aircraft engines) and associated components, equipment and systems. It also includes research and development in aerodynamics, aeronautics, and ground support equipment for aeronautical vehicles.

Aeronautical Engineering: A Continuing Bibliography with Indexes. Supplement 405

NASA Technical Reports Server (NTRS)

1999-01-01

This report lists reports, articles and other documents recently announced in the NASA STI Database. The coverage includes documents on the engineering and theoretical aspects of design, construction, evaluation, testing, operation, and performance of aircraft (including aircraft engines) and associated components, equipment, and systems. It also includes research and development in aerodynamics, aeronautics, and ground support equipment for aeronautical vehicles.

Aeronautical engineering: A continuing bibliography with indexes (supplement 284)

NASA Technical Reports Server (NTRS)

1992-01-01

This bibliography lists 974 reports, articles, and other documents introduced into the NASA scientific and technical information system in Oct. 1992. The coverage includes documents on design, construction, evaluation, testing, operation, and performance of aircraft (including aircraft engines) and associated components, equipment, and systems. It also includes research and development in aerodynamics, aeronautics, and ground support equipment for aeronautical vehicles.

Aeronautical engineering: A continuing bibliography with indexes (supplement 324)

NASA Technical Reports Server (NTRS)

1995-01-01

This bibliography lists 149 reports, articles, and other documents introduced into the NASA scientific and technical information system in December 1995. Subject coverage includes engineering and theoretical aspects of design, construction, evaluation, testing, operation, and performance of aircraft (including aircraft engines) and associated components, equipment, and systems. It also includes research and development in aerodynamics, aeronautics, and ground support equipment for aeronautical vehicles.

Aeronautical Engineering: A Continuing Bibliography With Indexes. Supplement 392

NASA Technical Reports Server (NTRS)

1999-01-01

This report lists reports, articles and other documents recently announced in the NASA STI Database. The coverage includes documents on the engineering and theoretical aspects of design, construction, evaluation, testing, operation, and performance of aircraft (including aircraft engines) and associated components, equipment, and systems. It also includes research and development in aerodynamics, aeronautics, and ground support equipment for aeronautical vehicles.

Aeronautical engineering: A continuing bibliography with indexes (supplement 319)

NASA Technical Reports Server (NTRS)

1995-01-01

This report lists 349 reports, articles and other documents recently announced in the NASA STI Database. The coverage includes documents on the engineering and theoretical aspects of design, construction, evaluation, testing, operation, and performance of aircraft (including aircraft engines) and associated components, equipment, and systems. It also includes research and development in aerodynamics, aeronautics, and ground support equipment for aeronautical vehicles.

Aeronautical engineering: A continuing bibliography with indexes (supplement 313)

NASA Technical Reports Server (NTRS)

1995-01-01

This bibliography lists 179 reports, articles, and other documents introduced into the NASA scientific and technical information system in Jan. 1995. Subject coverage includes: engineering and theoretical aspects of design, construction, evaluation, testing, operation, and performance of aircraft (including aircraft engines) and associated components, equipment, and systems. It also includes research and development in aerodynamics, aeronautics, and ground support equipment for aeronautical vehicles.

Aeronautical engineering: A continuing bibliography with indexes (supplement 310)

NASA Technical Reports Server (NTRS)

1994-01-01

This bibliography lists 29 reports, articles, and other documents introduced into the NASA scientific and technical information system in Nov. 1994. Subject coverage includes: engineering and theoretical aspects of design, construction,evaluation testing, operation, and performance of aircraft (including aircraft engines) and associated components, equipment and systems. It also includes research and development in aerodynamics, aeronautics, and ground support equipment for aeronautical vehicles.

Aeronautical Engineering: A Continuing Bibliography with Indexes. Supplement 415

NASA Technical Reports Server (NTRS)

2000-01-01

This supplemental issue of Aeronautical Engineering, A Continuing Bibliography with Indexes (NASA/SP-2000-7037) lists reports, articles, and other documents recently announced in the NASA STI Database. The coverage includes documents on the engineering and theoretical aspects of design, construction, evaluation, testing, operation, and performance of aircraft (including aircraft engines) and associated components, equipment, and systems. It also includes research and development in aerodynamics, aeronautics, and ground support equipment for aeronautical vehicles. Each entry in the publication consists of a standard bibliographic citation accompanied, in most cases, by an abstract. The NASA CASI price code table, addresses of organizations, and document availability information are included before the abstract section. Two indexes-subject and author are included after the abstract section.

Aeronautical Engineering: A Continuing Bibliography With Indexes. Supplement 407

NASA Technical Reports Server (NTRS)

1999-01-01

This supplemental issue of Aeronautical Engineering, A Continuing Bibliography with Indexes (NASA/SP-1999-7037) lists reports, articles, and other documents recently announced in the NASA STI Database. The coverage includes documents on the engineering and theoretical aspects of design, construction, evaluation, testing, operation, and performance of aircraft (including aircraft engines) and associated components, equipment, and systems. It also includes research and development in aerodynamics, aeronautics, and ground support equipment for aeronautical vehicles. Each entry in the publication consists of a standard bibliographic citation accompanied, in most cases, by an abstract. The NASA CASI price code table, addresses of organizations, and document availability information are included before the abstract section. Two indexes-subject and author are included after the abstract section.

Aeronautical Engineering: A Continuing Bibliography with Indexes. Supplement 408

NASA Technical Reports Server (NTRS)

1999-01-01

This supplemental issue of Aeronautical Engineering, a Continuing Bibliography with Indexes (NASA/SP#1999-7037) lists reports, articles, and other documents recently announced in the NASA STI Database. The coverage includes documents on the engineering and theoretical aspects of design, construction, evaluation, testing, operation, and performance of aircraft (including aircraft engines) and associated components, equipment, and systems. It also includes research and development in aerodynamics, aeronautics, and ground support equipment for aeronautical vehicles. Each entry in the publication consists of a standard bibliographic citation accompanied, in most cases, by an abstract. The NASA CASI price code table, addresses of organizations, and document availability information are included before the abstract section. Two indexes#subject and author are included after the abstract section.

Aeronautical Engineering: A Continuing Bibliography with Indexes. Supplement 411

NASA Technical Reports Server (NTRS)

2000-01-01

This supplemental issue of Aeronautical Engineering, A Continuing Bibliography with Indexes (NASA/SP-2000-7037) lists reports, articles, and other documents recently announced in the NASA STI Database. The coverage includes documents on the engineering and theoretical aspects of design, construction, evaluation, testing, operation, and performance of aircraft (including aircraft engines) and associated components, equipment, and systems. It also includes research and development in aerodynamics, aeronautics, and ground support equipment for aeronautical vehicles. Each entry in the publication consists of a standard bibliographic citation accompanied, in most cases, by an abstract. The NASA CASI price code table, addresses of organizations, and document availability information are included before the abstract section. Two indexes- subject and author are included after the abstract section.

Aeronautical Engineering: A Continuing Bibliography with Indexes. Supplment 394

NASA Technical Reports Server (NTRS)

1999-01-01

This supplemental issue of Aeronautical Engineering, A Continuing Bibliography with Indexes (NASA/SP-1999-7037) lists reports, articles, and other documents recently announced in the NASA STI Database. The coverage includes documents on the engineering and theoretical aspects of design, construction, evaluation, testing, operation, and performance of aircraft (including aircraft engines) and associated components, equipment, and systems. It also includes research and development in aerodynamics, aeronautics, and ground support equipment for aeronautical vehicles. Each entry in the publication consists of a standard bibliographic citation accompanied, in most cases, by an abstract. The NASA CASI price code table, addresses of organizations, and document availability information are included before the abstract section. Two indexes-subject and author are included after the abstract section.

Detection of underground water distribution piping system and leakages using ground penetrating radar (GPR)

NASA Astrophysics Data System (ADS)

Amran, Tengku Sarah Tengku; Ismail, Mohamad Pauzi; Ahmad, Mohamad Ridzuan; Amin, Mohamad Syafiq Mohd; Sani, Suhairy; Masenwat, Noor Azreen; Ismail, Mohd Azmi; Hamid, Shu-Hazri Abdul

2017-01-01

A water pipe is any pipe or tubes designed to transport and deliver water or treated drinking with appropriate quality, quantity and pressure to consumers. The varieties include large diameter main pipes, which supply entire towns, smaller branch lines that supply a street or group of buildings or small diameter pipes located within individual buildings. This distribution system (underground) is used to describe collectively the facilities used to supply water from its source to the point of usage. Therefore, a leaking in the underground water distribution piping system increases the likelihood of safe water leaving the source or treatment facility becoming contaminated before reaching the consumer. Most importantly, leaking can result in wastage of water which is precious natural resources. Furthermore, they create substantial damage to the transportation system and structure within urban and suburban environments. This paper presents a study on the possibility of using ground penetrating radar (GPR) with frequency of 1GHz to detect pipes and leakages in underground water distribution piping system. Series of laboratory experiment was designed to investigate the capability and efficiency of GPR in detecting underground pipes (metal and PVC) and water leakages. The data was divided into two parts: 1. detecting/locating underground water pipe, 2. detecting leakage of underground water pipe. Despite its simplicity, the attained data is proved to generate a satisfactory result indicating GPR is capable and efficient, in which it is able to detect the underground pipe and presence of leak of the underground pipe.

On designing of a low leakage patient-centric provider network.

PubMed

Zheng, Yuchen; Lin, Kun; White, Thomas; Pickreign, Jeremy; Yuen-Reed, Gigi

2018-03-27

When a patient in a provider network seeks services outside of their community, the community experiences a leakage. Leakage is undesirable as it typically leads to higher out-of-network cost for patient and increases barrier for care coordination, which is particularly problematic for Accountable Care Organization (ACO) as the in-network providers are financially responsible for quality of care and outcome. We aim to design a data-driven method to identify naturally occurring provider networks driven by diabetic patient choices, and understand the relationship among provider composition, patient composition, and service leakage pattern. By doing so, we learn the features of low service leakage provider networks that can be generalized to different patient population. Data used for this study include de-identified healthcare insurance administrative data acquired from Capital District Physicians' Health Plan (CDPHP) for diabetic patients who resided in four New York state counties (Albany, Rensselaer, Saratoga, and Schenectady) in 2014. We construct a healthcare provider network based on patients' historical medical insurance claims. A community detection algorithm is used to identify naturally occurring communities of collaborating providers. For each detected community, a profile is built using several new key measures to elucidate stakeholders of our findings. Finally, import-export analysis is conducted to benchmark their leakage pattern and identify further leakage reduction opportunity. The design yields six major provider communities with diverse profiles. Some communities are geographically concentrated, while others tend to draw patients with certain diabetic co-morbidities. Providers from the same healthcare institution are likely to be assigned to the same community. While most communities have high within-community utilization and spending, at 85% and 86% respectively, leakage still persists. Hence, we utilize a metric from import-export analysis to

Atomic Oxygen Effects on Seal Leakage

NASA Technical Reports Server (NTRS)

Christensen, John R.; Underwood, Steve D.; Kamenetzky, Rachel R.; Vaughn, Jason A.

1999-01-01

Common Berthing Mechanism (CBM provides the structural interface between separate International Space Station (ISS) elements, such as the Laboratory and Node modules. The CBM consists of an active and a passive half that join together with structural bolts. The seal at this interface is the CBM-to-CBM molded seal. The CBM-to-CBM interface is assembled on orbit, thus the seals can be exposed to the space environment for up to 65 hours. Atomic Oxygen/Vacuum Ultraviolet radiation (AO/VUV) in space is a potential hazard to the seals. Testing was conducted to determine the effect on leakage of the CBM-to-CBM seal material exposed to AO/VUV. The sealing materials were S383 silicone and V835 fluorocarbon material. Control samples, which were not exposed to the AO/VUV environment, were used to ensure that ff any changes in leakage occurred, they could be attributed to the AO/VUV exposure. After exposure to the AO/VUV environment the leakage increase was dramatic for the fluorocarbon. This testing was a major contributing factor in selecting silicone as the CBM-to-CBM seal material.

77 FR 17104 - Government/Industry Aeronautical Charting Forum Meeting: Correction

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-23

...) Aeronautical Charting Forum (ACF) to discuss informational content and design of aeronautical charts and related products, as well as instrument flight procedures development policy and design criteria. DATES: The ACF is separated into two distinct groups. The Instrument Procedures Group (IPG) will meet April...

Aeronautical technologies for the twenty-first century

NASA Technical Reports Server (NTRS)

1992-01-01

This study gives an overview of the future technologies in aeronautics. This collaborative effort relies upon the input of numerous experts from around the country. Specific issues covered include subsonic transport aircraft, high-speed civil transport aircraft short-haul aircraft, environmental issues, operational issues, aerodynamics, propulsion, materials and structures, avionics and control, and cognitive engineering. The appendices include bibliography, abbreviations and acronyms, and NASA fiscal year 1992 aeronautics funding (table) and participants. The forward states that over the last decade, foreign aircraft manufacturers have made significant inroads into the global aircraft market, to the detriment of U.S. interests. Recommendations are made to counter that trend.

Langley aeronautics and space test highlights, 1984

NASA Technical Reports Server (NTRS)

1984-01-01

The role of the Langley Research Center is to perform basic and applied research necessary for the advancement of aeronautics and space flight, to generate new and advanced concepts for the accomplishment of related national goals, and to provide research advice, technological support, and assistance to other NASA installations, other government agencies, and industry. Some of the significant tests which were performed during calendar year 1984 in Langley test facilities are highlighted. The broad range of the research and technology activities at the Langley Research Center and the contributions of this work toward maintaining United States leadership in aeronautics and space research are illustrated.

Inmarsat aeronautical mobile satellite system: Internetworking issues

NASA Technical Reports Server (NTRS)

Sengupta, Jay R.

1990-01-01

The Inmarsat Aeronautical Mobile Satellite System (AMSS) provides air-ground and air-air communications services to aero-mobile users on a global basis. Communicating parties may be connected either directly, or more commonly, via interconnecting networks to the Inmarsat AMSS, in order to construct end-to-end communications circuits. The aircraft earth station (AES) and the aeronautical ground earth station (GES) are the points of interconnection of the Inmarsat AMSS to users, as well as to interconnecting networks. This paper reviews the internetworking aspects of the Inmarsat AMSS, by introducing the Inmarsat AMSS network architecture and services concepts and then discussing the internetwork address/numbering and routing techniques.

Wireless Sensor Applications in Extreme Aeronautical Environments

NASA Technical Reports Server (NTRS)

Wilson, William C.; Atkinson, Gary M.

2013-01-01

NASA aeronautical programs require rigorous ground and flight testing. Many of the testing environments can be extremely harsh. These environments include cryogenic temperatures and high temperatures (greater than 1500 C). Temperature, pressure, vibration, ionizing radiation, and chemical exposure may all be part of the harsh environment found in testing. This paper presents a survey of research opportunities for universities and industry to develop new wireless sensors that address anticipated structural health monitoring (SHM) and testing needs for aeronautical vehicles. Potential applications of passive wireless sensors for ground testing and high altitude aircraft operations are presented. Some of the challenges and issues of the technology are also presented.

77 FR 14445 - Leakage Tests on Packages for Shipment of Radioactive Material

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-09

... NUCLEAR REGULATORY COMMISSION [NRC-2011-0045] Leakage Tests on Packages for Shipment of..., ``Leakage Tests on Packages for Radioactive Material.'' ADDRESSES: You can access publicly available... Materials--Leakage Tests on Packages for Shipment'' approved February 1998. The NRC staff developed and...

[Detection of marginal leakage of Class V restorations in vitro by micro-CT].

PubMed

Gu, Lin-juan; Zhao, Xin-yi; Li, Shi-bao

2012-09-01

To evaluate the reliability and superiority of micro-CT in marginal leakage assessment of Class V restorations. Class V preparations with gingival margins in dentin and occlusal in enamel were made in sixteen extracted non-carious human molars and restored with dental bonding agents and composite resin. All teeth were then immersed in 50% ammonia-silver nitrate solution for 12 hours, followed by developing solution for 8 hours. Each restoration was scanned by a micro-CT and silver leakage was measured and three-dimensional image of the silver leakage alone cavity wall were reconstructed. Afterward, all restorations were sectioned and examined for leakage depth using a microscope. The silver leakage depth of each restoration obtained by micro-CT and microscope were compared for equivalency. The silver leakage depths in gingival wall obtained with micro-CT (0.78 mm) and microscope (0.74 mm) showed no significant difference (P > 0.05), while the judgment of leakage depths in occlusal wall in micro-CT image (0.40 mm) was affected by adjacent enamel structure, giving less leakage depths compared to microscope (0.72 mm)(P < 0.01). The three-dimensional shapes of the microleakages displayed clearly by micro-CT alone wall of Class V restorations were multiform and some leakages showed channels on their way to spreading. Micro-CT can detect precisely the silver leakage in the dentin wall of a restoration and display its three-dimensional shape fully. Enamel structure affects the detection of the silver leakage next to it.

Dehydration Effects on Imbibitional Leakage from Desiccation-Sensitive Seeds 1

PubMed Central

Becwar, Michael R.; Stanwood, Phillip C.; Roos, Eric E.

1982-01-01

Changes in electrolyte leakage and viability in response to dehydration stress were examined in two species of seeds that do not survive desiccation. Leakage from silver maple (Acer saccharinum L.) seeds increased markedly as seed moisture contents decreased from 45 to 35% (fresh weight basis) and germination decreased from 97 to 5%, coincidentally. Time course curves of imbibitional leakage from areca palm (Chrysalido-carpus lutescens [Bory] Wendl.) embryos showed an increase in both initial leakage and steady-state leakage rates in response to dehydration from an original moisture content of 84 to as low as 53%. Absorbance at 530 nanometers of extracts from triphenyl tetrazolium chloride stained embryos of areca palm was used as a measure of viability. Absorbance decreased significantly in response to dehydration as embryo moisture content decreased from 80 to 30%. Collectively, the data suggest that membranes in the desiccation-sensitive seed tissues studied are damaged by dehydration below a critical moisture content, 40% in silver maple seed and 55% in areca palm embryos, and that the membrane damage contributes to loss of viability. PMID:16662357

Astronautics and aeronautics, 1977: A chronology

NASA Technical Reports Server (NTRS)

Ritchie, E. H.

1986-01-01

This publication is a chronology of events during the year 1977 in the fields of aeronautical and space research, development, activity, and policy. It includes appendixes, an index, and illustrations. Chronological entries list sources for further inquiry.

Numerical studies on the performance of an aerosol respirator with faceseal leakage

NASA Astrophysics Data System (ADS)

Zaripov, S. K.; Mukhametzanov, I. T.; Grinshpun, S. A.

2016-11-01

We studied the efficiency of a facepiece filtering respirator (FFR) in presence of a measurable faceseal leakage using the previously developed model of a spherical sampler with porous layer. In our earlier study, the model was validated for a specific filter permeability value. In this follow-up study, we investigated the effect of permeability on the overall respirator performance accounting for the faceseal leakage. The Total Inward Leakage (TIL) was calculated as a function of the leakage-to-filter surface ratio and the particle diameter. A good correlation was found between the theoretical and experimental TIL values. The TIL value was shown to increase and the effect of particle size on TIL to decrease as the leakage-to- filter surface ratio grows. The model confirmed that within the most penetrating particle size range (∼50 nm) and at relatively low leakage-to-filter surface ratios, an FFR performs better (TIL is lower) when the filter has a lower permeability which should be anticipated as long as the flow through the filter represents the dominant particle penetration pathway. An increase in leak size causes the TIL to rise; furthermore, under certain leakage-to-filter surface ratios, TIL for ultrafine particles becomes essentially independent on the filter properties due to a greater contribution of the aerosol flow through the faceseal leakage. In contrast to the ultrafine fraction, the larger particles (e.g., 800 nm) entering a typical high- or medium-quality respirator filter are almost fully collected by the filter medium regardless of its permeability; at the same time, the fraction penetrated through the leakage appears to be permeability- dependent: higher permeability generally results in a lower pressure drop through the filter which increases the air flow through the filter at the expense of the leakage flow. The latter reduces the leakage effect thus improving the overall respiratory protection level. The findings of this study provide

Aeronautics and Aviation Science: Careers and Opportunities Project

NASA Technical Reports Server (NTRS)

Texter, P. Cardie

1998-01-01

The National Aeronautics and Space Administration funded project, Aeronautics and Aviation Science: Careers and Opportunities has been in operation since July, 1995. This project operated as a collaboration with Massachusetts Corporation for Educational Telecommunications, the Federal Aviation Administration, Bridgewater State College and four targeted "core sites" in the greater Boston area. In its first and second years, a video series on aeronautics and aviation science was developed and broadcast via "live, interactive" satellite feed. Accompanying teacher and student supplementary instructional materials for grades 6-9 were produced and disseminated by the Massachusetts Corporation for Educational Telecommunications (MCET). In the MCET grant application it states that project Take Off! in its initial phase would recruit and train teachers at "core" sites in the greater Boston area, as well as opening participation to other on-line users of MCET's satellite feeds. "Core site" classrooms would become equipped so that teachers and students might become engaged in an interactive format which aimed at not only involving the students during the "live" broadcast of the instructional video series, but which would encourage participation in electronic information gathering and sharing among participants. As a Take Off! project goal, four schools with a higher than average proportion of minority and underrepresented youth were invited to become involved with the project to give these students the opportunity to consider career exploration and development in the field of science aviation and aeronautics. The four sites chosen to participate in this project were: East Boston High School, Dorchester High School, Randolph Junior-Senior High School and Malden High School. In year 3 Dorchester was unable to continue to fully participate and exited out. Danvers was added to the "core site" list in year 3. In consideration of Goals 2000, the National Science Foundation

A distributed data acquisition system for aeronautics test facilities

NASA Technical Reports Server (NTRS)

Fronek, Dennis L.; Setter, Robert N.; Blumenthal, Philip Z.; Smalley, Robert R.

1987-01-01

The NASA Lewis Research Center is in the process of installing a new data acquisition and display system. This new system will provide small and medium sized aeronautics test facilities with a state-of-the-art real-time data acquisition and display system. The new data system will provide for the acquisition of signals from a variety of instrumentation sources. They include analog measurements of temperatures, pressures, and other steady state voltage inputs; frequency inputs to measure speed and flow; discrete I/O for significant events, and modular instrument systems such as multiplexed pressure modules or electronic instrumentation with a IEEE 488 interface. The data system is designed to acquire data, convert it to engineering units, compute test dependent performance calculations, limit check selected channels or calculations, and display the information in alphanumeric or graphical form with a cycle time of one second for the alphanumeric data. This paper describes the system configuration, its salient features, and the expected impact on testing.

Aeronautical engineering: A continuing bibliography with indexes (supplement 119)

NASA Technical Reports Server (NTRS)

1980-01-01

This bibliography lists 341 reports, articles, and other documents introduced into the NASA scientific and technical information system in January 1980. Abstracts on the engineering and theoretical aspects of design, construction, evaluation, testing, operation, and performance of aircraft (including aircraft engines) and associated components, equipment, and systems are presented. Research and development in aerodynamics, aeronautics, and ground support equipment for aeronautical vehicles are also presented.

Aeronautical engineering: A continuing bibliography with indexes (supplement 282)

NASA Technical Reports Server (NTRS)

1992-01-01

This bibliography lists 623 reports, articles, and other documents introduced into the NASA scientific and technical information system in Aug. 1992. The coverage includes documents on the engineering and theoretical aspects of design, construction, evaluation, testing, operation, and performance of aircraft (including aircraft engines) and associated components, equipment, and systems. It also includes research and development in aerodynamics, aeronautics, and ground support equipment for aeronautical vehicles.

A cumulative index to Aeronautical Engineering: A special bibliography

NASA Technical Reports Server (NTRS)

1978-01-01

This publication is a cumulative index to the abstracts contained in NASA SP-7037 (80) through NASA SP-7037 (91) of Aeronautical Engineering: A Special Bibliography. NASA SP-7037 and its supplements have been compiled through the cooperative efforts of the American Institute of Aeronautics (AIAA) and Space Administration (NASA). This cumulative index includes subject, personal author, corporate source, contract, and report number indexes.

Automated detection of leakage in fluorescein angiography images with application to malarial retinopathy.

PubMed

Zhao, Yitian; MacCormick, Ian J C; Parry, David G; Leach, Sophie; Beare, Nicholas A V; Harding, Simon P; Zheng, Yalin

2015-06-01

The detection and assessment of leakage in retinal fluorescein angiogram images is important for the management of a wide range of retinal diseases. We have developed a framework that can automatically detect three types of leakage (large focal, punctate focal, and vessel segment leakage) and validated it on images from patients with malarial retinopathy. This framework comprises three steps: vessel segmentation, saliency feature generation and leakage detection. We tested the effectiveness of this framework by applying it to images from 20 patients with large focal leak, 10 patients with punctate focal leak, and 5,846 vessel segments from 10 patients with vessel leakage. The sensitivity in detecting large focal, punctate focal and vessel segment leakage are 95%, 82% and 81%, respectively, when compared to manual annotation by expert human observers. Our framework has the potential to become a powerful new tool for studying malarial retinopathy, and other conditions involving retinal leakage.

Clear corneal incision leakage after phacoemulsification--detection using povidone iodine 5%.

PubMed

Chee, Soon-Phaik

2005-01-01

The purpose of this work was to study the incidence of clear corneal wound leakage at the conclusion of standard co-axial phacoemulsification in a prospective observational series of 100 consecutive cataract cases in a single surgeon's institutional practice. At the conclusion of standard co-axial phacoemulsification using a 2.75 mm temporal single plane clear corneal incision with a 1 mm clear corneal side-port incision, the wounds were hydrated and checked for water-tightness. Povidone iodine 5% (P-I) was then evenly dripped over the cornea and the wounds were inspected visually. Any leakage of aqueous observed was recorded. The amount of leakage was graded as small or large from each wound. Leaky wounds were further hydrated and retested with P-I until sealed. Wound integrity was reassessed on the first postoperative day by use of fluorescein. Of the 100 cases, wound leakage was observed for 31 eyes (31%)-ten main incisions, nineteen side-port incisions, and both incisions in two cases. Wound leakage was easily detected as a ribbon of clear fluid streaming from the incision amid a pool of brown solution. Povidone iodine was not observed within the tract in any incision. All wound leakage was small except for one from the main incision and two from the side-port incision. None of the eyes developed wound leakage the day after surgery and none developed endophthalmitis. In conclusion, leakage from clear corneal incisions at the conclusion of phacoemulsification occurs in almost a third of cases, predominantly from the side incision. It is easily detected by use of the P-I test.

Theory and Application of Magnetic Flux Leakage Pipeline Detection.

PubMed

Shi, Yan; Zhang, Chao; Li, Rui; Cai, Maolin; Jia, Guanwei

2015-12-10

Magnetic flux leakage (MFL) detection is one of the most popular methods of pipeline inspection. It is a nondestructive testing technique which uses magnetic sensitive sensors to detect the magnetic leakage field of defects on both the internal and external surfaces of pipelines. This paper introduces the main principles, measurement and processing of MFL data. As the key point of a quantitative analysis of MFL detection, the identification of the leakage magnetic signal is also discussed. In addition, the advantages and disadvantages of different identification methods are analyzed. Then the paper briefly introduces the expert systems used. At the end of this paper, future developments in pipeline MFL detection are predicted.

Geologic Carbon Sequestration Leakage Detection: A Physics-Guided Machine Learning Approach

NASA Astrophysics Data System (ADS)

Lin, Y.; Harp, D. R.; Chen, B.; Pawar, R.

2017-12-01

One of the risks of large-scale geologic carbon sequestration is the potential migration of fluids out of the storage formations. Accurate and fast detection of this fluids migration is not only important but also challenging, due to the large subsurface uncertainty and complex governing physics. Traditional leakage detection and monitoring techniques rely on geophysical observations including pressure. However, the resulting accuracy of these methods is limited because of indirect information they provide requiring expert interpretation, therefore yielding in-accurate estimates of leakage rates and locations. In this work, we develop a novel machine-learning technique based on support vector regression to effectively and efficiently predict the leakage locations and leakage rates based on limited number of pressure observations. Compared to the conventional data-driven approaches, which can be usually seem as a "black box" procedure, we develop a physics-guided machine learning method to incorporate the governing physics into the learning procedure. To validate the performance of our proposed leakage detection method, we employ our method to both 2D and 3D synthetic subsurface models. Our novel CO2 leakage detection method has shown high detection accuracy in the example problems.

Determination of leakage areas in nuclear piping

DOE Office of Scientific and Technical Information (OSTI.GOV)

Keim, E.

1997-04-01

For the design and operation of nuclear power plants the Leak-Before-Break (LBB) behavior of a piping component has to be shown. This means that the length of a crack resulting in a leak is smaller than the critical crack length and that the leak is safely detectable by a suitable monitoring system. The LBB-concept of Siemens/KWU is based on computer codes for the evaluation of critical crack lengths, crack openings, leakage areas and leakage rates, developed by Siemens/KWU. In the experience with the leak rate program is described while this paper deals with the computation of crack openings and leakagemore » areas of longitudinal and circumferential cracks by means of fracture mechanics. The leakage areas are determined by the integration of the crack openings along the crack front, considering plasticity and geometrical effects. They are evaluated with respect to minimum values for the design of leak detection systems, and maximum values for controlling jet and reaction forces. By means of fracture mechanics LBB for subcritical cracks has to be shown and the calculation of leakage areas is the basis for quantitatively determining the discharge rate of leaking subcritical through-wall cracks. The analytical approach and its validation will be presented for two examples of complex structures. The first one is a pipe branch containing a circumferential crack and the second one is a pipe bend with a longitudinal crack.« less

Air Leakage of US Homes: Regression Analysis and Improvements from Retrofit

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chan, Wanyu R.; Joh, Jeffrey; Sherman, Max H.

2012-08-01

LBNL Residential Diagnostics Database (ResDB) contains blower door measurements and other diagnostic test results of homes in United States. Of these, approximately 134,000 single-family detached homes have sufficient information for the analysis of air leakage in relation to a number of housing characteristics. We performed regression analysis to consider the correlation between normalized leakage and a number of explanatory variables: IECC climate zone, floor area, height, year built, foundation type, duct location, and other characteristics. The regression model explains 68% of the observed variability in normalized leakage. ResDB also contains the before and after retrofit air leakage measurements of approximatelymore » 23,000 homes that participated in weatherization assistant programs (WAPs) or residential energy efficiency programs. The two types of programs achieve rather similar reductions in normalized leakage: 30% for WAPs and 20% for other energy programs.« less

Aeronautical and Maritime Satellite Technology Bibliography

DOT National Transportation Integrated Search

1976-03-01

Material used and generated over the past five years on the aeronautical and maritime satellite programs has been reviewed and organized in this report. Emphasis has been placed on advanced electronic technology and its application to the satellite s...

Electromagnetic inhibition of high frequency thermal bonding machine

NASA Astrophysics Data System (ADS)

He, Hong; Zhang, Qing-qing; Li, Hang; Zhang, Da-jian; Hou, Ming-feng; Zhu, Xian-wei

2011-12-01

The traditional high frequency thermal bonding machine had serious radiation problems at dominant frequency, two times frequency and three times frequency. Combining with its working principle, the problems of electromagnetic compatibility were studied, three following measures were adopted: 1.At the head part of the high frequency thermal bonding machine, resonant circuit attenuator was designed. The notch groove and reaction field can make the radiation being undermined or absorbed; 2.The electromagnetic radiation shielding was made for the high frequency copper power feeder; 3.Redesigned the high-frequency oscillator circuit to reduce the output of harmonic oscillator. The test results showed that these measures can make the output according with the national standard of electromagnetic compatibility (GB4824-2004-2A), the problems of electromagnetic radiation leakage can be solved, and good social, environmental and economic benefits would be brought.

Effect of Post-HALT Annealing on Leakage Currents in Solid Tantalum Capacitors

NASA Technical Reports Server (NTRS)

Teverovsky, Alexander

2010-01-01

Degradation of leakage currents is often observed during life testing of tantalum capacitors and is sometimes attributed to the field-induced crystallization in amorphous anodic tantalum pentoxide dielectrics. However, degradation of leakage currents and the possibility of annealing of degraded capacitors have not been investigated yet. In this work the effect of annealing after highly accelerated life testing (HALT) on leakage currents in various types of solid tantalum capacitors was analyzed. Variations of leakage currents with time during annealing at temperatures from 125 oC to 180 oC, thermally stimulated depolarization (TSD) currents, and I-V characteristics were measured to understand the conduction mechanism and the reason for current degradation. Annealing resulted in a gradual decrease of leakage currents and restored their initial values. Repeat HALT after annealing resulted in reproducible degradation of leakage currents. The observed results are explained based on ionic charge instability (drift/diffusion of oxygen vacancies) in the tantalum pentoxide dielectrics using a modified Schottky conduction mechanism.

SETI VIA LEAKAGE FROM LIGHT SAILS IN EXOPLANETARY SYSTEMS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guillochon, James; Loeb, Abraham, E-mail: jguillochon@cfa.harvard.edu, E-mail: aloeb@cfa.harvard.edu

The primary challenge of rocket propulsion is the burden of needing to accelerate the spacecraft’s own fuel, resulting in only a logarithmic gain in maximum speed as propellant is added to the spacecraft. Light sails offer an attractive alternative in which fuel is not carried by the spacecraft, with acceleration being provided by an external source of light. By artificially illuminating the spacecraft with beamed radiation, speeds are only limited by the area of the sail, heat resistance of its material, and power use of the accelerating apparatus. In this paper, we show that leakage from a light sail propulsionmore » apparatus in operation around a solar system analogue would be detectable. To demonstrate this, we model the launch and arrival of a microwave beam-driven light sail constructed for transit between planets in orbit around a single star, and find an optimal beam frequency on the order of tens of GHz. Leakage from these beams yields transients with flux densities of Jy and durations of tens of seconds at 100 pc. Because most travel within a planetary system would be conducted between the habitable worlds within that system, multiply transiting exoplanetary systems offer the greatest chance of detection, especially when the planets are in projected conjunction as viewed from Earth. If interplanetary travel via beam-driven light sails is commonly employed in our galaxy, this activity could be revealed by radio follow-up of nearby transiting exoplanetary systems. The expected signal properties define a new strategy in the search for extraterrestrial intelligence (SETI)« less

SETI via Leakage from Light Sails in Exoplanetary Systems

NASA Astrophysics Data System (ADS)

Guillochon, James; Loeb, Abraham

2015-10-01

The primary challenge of rocket propulsion is the burden of needing to accelerate the spacecraft’s own fuel, resulting in only a logarithmic gain in maximum speed as propellant is added to the spacecraft. Light sails offer an attractive alternative in which fuel is not carried by the spacecraft, with acceleration being provided by an external source of light. By artificially illuminating the spacecraft with beamed radiation, speeds are only limited by the area of the sail, heat resistance of its material, and power use of the accelerating apparatus. In this paper, we show that leakage from a light sail propulsion apparatus in operation around a solar system analogue would be detectable. To demonstrate this, we model the launch and arrival of a microwave beam-driven light sail constructed for transit between planets in orbit around a single star, and find an optimal beam frequency on the order of tens of GHz. Leakage from these beams yields transients with flux densities of Jy and durations of tens of seconds at 100 pc. Because most travel within a planetary system would be conducted between the habitable worlds within that system, multiply transiting exoplanetary systems offer the greatest chance of detection, especially when the planets are in projected conjunction as viewed from Earth. If interplanetary travel via beam-driven light sails is commonly employed in our galaxy, this activity could be revealed by radio follow-up of nearby transiting exoplanetary systems. The expected signal properties define a new strategy in the search for extraterrestrial intelligence (SETI).

Aeronautical Materials (Selected Articles),

DTIC Science & Technology

1984-03-13

directional technique. We would like to deeply thank comrades Dong Yuzhuo, Liu Nianqing, Yuan Pinzhen, Sun Shuzhen, Li Shuhuan etc. and other fraternal units...1Burton, C.J7., "Superalloys, Metallurgy and -Manufacture", Li 1976, p14 7. P [3 1Cai Julin and Zheng Yunrong, "A Study of the Interdend- ritic...of the Beijing Institute of Aeronautical Materials, Liu Ansheng and Li Yonghong of the General Academy of Nonferrous Metals, Yang Yanhua of the Coal

Automated Detection of Leakage in Fluorescein Angiography Images with Application to Malarial Retinopathy

PubMed Central

Zhao, Yitian; J. C. MacCormick, Ian; G. Parry, David; Leach, Sophie; A. V. Beare, Nicholas; P. Harding, Simon; Zheng, Yalin

2015-01-01

The detection and assessment of leakage in retinal fluorescein angiogram images is important for the management of a wide range of retinal diseases. We have developed a framework that can automatically detect three types of leakage (large focal, punctate focal, and vessel segment leakage) and validated it on images from patients with malarial retinopathy. This framework comprises three steps: vessel segmentation, saliency feature generation and leakage detection. We tested the effectiveness of this framework by applying it to images from 20 patients with large focal leak, 10 patients with punctate focal leak, and 5,846 vessel segments from 10 patients with vessel leakage. The sensitivity in detecting large focal, punctate focal and vessel segment leakage are 95%, 82% and 81%, respectively, when compared to manual annotation by expert human observers. Our framework has the potential to become a powerful new tool for studying malarial retinopathy, and other conditions involving retinal leakage. PMID:26030010

Aeronautical Engineering: A special bibliography with indexes, supplement 13

NASA Technical Reports Server (NTRS)

1972-01-01

This special bibliography lists 283 reports, articles, and other documents introduced into the NASA scientific and technical information system in December, 1971. Emphasis is placed on engineering and theoretical aspects for design, construction, evaluation, testing, operation and performance of aircraft (including aircraft engines), and associated components, equipment and systems. Also included are entries on research and development in aeronautics and aerodynamics and research and ground support for aeronautical vehicles.

Aeronautical Engineering, a special bibliography with indexes, supplement 15

NASA Technical Reports Server (NTRS)

1972-01-01

This special bibliography lists 363 reports, articles, and other documents introduced into the NASA scientific and technical information system in January 1972. Emphasis is placed on engineering and theoretical aspects for design, construction, evaluation, testing, operation and performance of aircraft (including aircraft engines) and associated components, equipment and systems. Also included are entries on research and development in aeronautics and aerodynamics and research and ground support for aeronautical vehicles.

Kennedy Educate to Innovate (KETI) Aeronautics PowerPoint Presentation

NASA Technical Reports Server (NTRS)

Davila, Dina

2010-01-01

This slide presentation reviews some fundamental features of aeronautics. It is designed to introduce students to aeronautics and to engage them in Science Technology Education and Mathematics (STEM). It reviews the history of airflight, the aircraft components and their interaction with the forces that make flight possible (i.e. lift, weight drag and thrust), and the interaction of the components that create aircraft movements (roll, pitch and yaw)

Langley aeronautics and space test highlights, 1983

NASA Technical Reports Server (NTRS)

1984-01-01

The role of the Langley Research Center is to perform basic and applied research necessary for the advancement of aeronautics and space flight, to generate new and advanced concepts for the accomplishment of related national goals, and to provide research advice, technological support, and assistance to other NASA installations, other government agencies, and industry. Some of the significant tests which were performed during calendar year 1983 in Langley test facilities, a number of which are unique in the world are highlighted. Both the broad range of the research and technology activities at the Langley Research Center and the contributions of this work toward maintaining United States leadership in aeronautics and space research are illustrated.

Aeronautics and Space Report of the President

NASA Technical Reports Server (NTRS)

1991-01-01

The years 1989 to 1990 activities are reported including human space flight, unmanned expendable launch vehicles, space science and applications, space communications operations, space research and technology, and aeronautics research and technology. Contributions made by the 14 participating government organizations are outline. Each organization's aeronautics and/or space activities for the year are presented. The organizations involved include: (1) NASA; (2) Dept. of Defense; (3) Dept. of Commerce; (4) Dept. of Energy; (5) Dept. of the Interior; (6) Dept. of Agriculture; (7) Federal Communications Commission; (8) Dept. of Transportation; (9) Environmental Protection Agency; (10) National Science Foundation; (11) Smithsonian Institution; (12) Dept. of State; (13) Arms Control and Disarmament; and (14) United States Information Agency.

Proton-irradiation technology for high-frequency high-current silicon welding diode manufacturing

NASA Astrophysics Data System (ADS)

Lagov, P. B.; Drenin, A. S.; Zinoviev, M. A.

2017-05-01

Different proton irradiation regimes were tested to provide more than 20 kHz-frequency, soft reverse recovery “snap-less” behavior, low forward voltage drop and leakage current for 50 mm diameter 7 kA/400 V welding diode Al/Si/Mo structure. Silicon diode with such parameters is very suitable for high frequency resistance welding machines of new generation for robotic welding.

T-drain reduces the incidence of biliary leakage after liver resection.

PubMed

Eurich, Dennis; Henze, S; Boas-Knoop, S; Pratschke, J; Seehofer, D

2016-12-01

Biliary leakage is a serious complication after liver resection and represents the major cause of post-operative morbidity. In spite of already identified risk factors, little is known about the role of intra-biliary pressure following liver surgery in the development of biliary leakage. Biliary decompression may have a positive impact and reduce the incidence of biliary leakage at the parenchymal resection site. 397 patients undergoing liver resection without bilioenteric anastomosis were included in the retrospective analysis of the risk factors for the development of biliary leakage focusing on the intra-operative reduction of the biliary pressure by T-tube and liver histology. Among 397 analyzed patients after parenchymal resection, biliary leakage occurred in 39 cases (9.8 %). The extent of parenchymal resection was not associated with the total occurrence of biliary leak (p = 0.626). Lower incidence of biliary leakage from the resection surface was significantly associated with the use of T-tube (4.9 vs. 13.2 %; p = 0.006). In the subgroup analysis, insertion of a T-tube was not associated with a reduction of biliary leakage after anatomical hemihepatectomies (p = 0.103) and extraanatomical liver resection (p = 0.676). However, a high statistical significance could be detected in patients with extended hemihepatectomies (58.3 vs. 3.8 %; p < 0.001). Once biliary leak occurred without T-tube, median hospitalization duration significantly increased compared to patients with biliary decompression and without biliary leak (p < 0.001). The results of our retrospective data analysis suggest a significant beneficial impact of the T-tube on the development of biliary leakage in patients undergoing extended liver surgery.

Aeronautical engineering, a special bibliography, September 1971 (supplement 10)

NASA Technical Reports Server (NTRS)

1971-01-01

This supplement to Aeronautical Engineering-A Special Bibliography (NASA SP-7037) lists 413 reports, journal articles, and other documents originally announced in September 1971 in Scientific and Technical Aerospace Reports (STAR) or in International Aerospace Abstracts (IAA). The coverage includes documents on the engineering and theoretical aspects of design, construction, evaluation, testing, operation, and performance of aircraft (including aircraft engines) and associated components, equipment, and systems. It also includes research and development in aerodynamics, aeronautics, and ground support equipment for aeronautical vehicles. Each entry in the bibliography consists of a standard bibliographic citation accompanied by an abstract. The listing of the entries is arranged in two major sections, IAA Entries and STAR Entries in that order. The citations and abstracts are reproduced exactly as they appeared originally in IAA or STAR, including the original accession numbers from the respective announcement journals.

78 FR 51809 - Seventeenth Meeting: RTCA Special Committee 217-Aeronautical Databases Joint With EUROCAE WG-44...

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Theory and Application of Magnetic Flux Leakage Pipeline Detection

PubMed Central

Shi, Yan; Zhang, Chao; Li, Rui; Cai, Maolin; Jia, Guanwei

2015-01-01

Magnetic flux leakage (MFL) detection is one of the most popular methods of pipeline inspection. It is a nondestructive testing technique which uses magnetic sensitive sensors to detect the magnetic leakage field of defects on both the internal and external surfaces of pipelines. This paper introduces the main principles, measurement and processing of MFL data. As the key point of a quantitative analysis of MFL detection, the identification of the leakage magnetic signal is also discussed. In addition, the advantages and disadvantages of different identification methods are analyzed. Then the paper briefly introduces the expert systems used. At the end of this paper, future developments in pipeline MFL detection are predicted. PMID:26690435

Reverse Aging of Composite Materials for Aeronautical Applications

NASA Astrophysics Data System (ADS)

lannone, Michele

2008-08-01

Hygro-thermal ageing of polymer matrix composite materials is a major issue for all the aeronautical structures. For carbon-epoxy composites generally used in aeronautical applications the major effect of ageing is the humidity absorption, which induces a plasticization effect, generally decreasing Tg and elastic moduli, and finally design allowables. A thermodynamical and kinetic study has been performed, aimed to establish a program of periodic heating of the composite part, able to reversing the ageing effect by inducing water desorption. The study was founded on a simple model based on Fick's law, coupled with a concept of "relative saturation coefficient" depending on the different temperature of the composite part and the environment. The behaviour of some structures exposed to humidity and "reverse aged" by heating has been virtually tested. The conclusion of the study allowed to issue a specific patent application for aeronautical structures to be designed on the basis of a "humidity free" concept which allows the use of higher design allowables; having as final results lighter composite structures with a simplified certification process.

Development of Structural Energy Storage for Aeronautics Applications

NASA Technical Reports Server (NTRS)

Santiago-Dejesus, Diana; Loyselle, Patricia L.; Demattia, Brianne; Bednarcyk, Brett; Olson, Erik; Smith, Russell; Hare, David

2017-01-01

The National Aeronautics and Space Administration (NASA) has identified Multifunctional Structures for High Efficiency Lightweight Load-bearing Storage (M-SHELLS) as critical to development of hybrid gas-electric propulsion for commercial aeronautical transport in the N+3 timeframe. The established goals include reducing emissions by 80 and fuel consumption by 60 from todays state of the art. The advancement will enable technology for NASA Aeronautics Research Mission Directorates (ARMD) Strategic Thrust 3 to pioneer big leaps in efficiency and environmental performance for ultra-efficient commercial transports, as well as Strategic Thrust 4 to pioneer low-carbon propulsion technology in the transition to that scheme. The M-SHELLS concept addresses the hybrid gas-electric highest risk with its primary objective: to save structures energy storage system weight for future commercial hybrid electric propulsion aircraft by melding the load-carrying structure with energy storage in a single material. NASA's multifunctional approach also combines supercapacitor and battery chemistries in a synergistic energy storage arrangement in tandem with supporting good mechanical properties. The arrangement provides an advantageous combination of specific power, energy, and strength.

Aeronautics and Space Report of the President: Fiscal Year 2005 Activities

NASA Technical Reports Server (NTRS)

2007-01-01

The National Aeronautics and Space Act of 1958 directed the annual Aeronautics and Space Report to include a "comprehensive description of the programmed activities and the accomplishments of all agencies of the United States in the field of aeronautics and space activities during the preceding calendar year." In recent years, the reports have been prepared on a fiscal-year basis, consistent with the budgetary period now used in programs of the Federal Government. This year's report covers activities that took place from October 1 , 2004, through September 30, 2005.

Aeronautics and Space Report of the President: Fiscal Year 2001 Activities

NASA Technical Reports Server (NTRS)

2001-01-01

The National Aeronautics and Space Act of 1958 directed the annual Aeronautics and Space Report to include a 'comprehensive description of the programmed activities and the accomplishments of all agencies of the United States in the field of aeronautics and space activities during the preceding calendar year.' In recent years the reports have been prepared on a fiscal-year basis consistent with the budgetary period now used in programs of the Federal Government. This year's report covers activities that took place from October 1, 2000, through September 30, 2001.

Aeronautics and Space Report of the President: Fiscal Year 2003 Activities

NASA Technical Reports Server (NTRS)

2003-01-01

The National Aeronautics and Space Act of 1958 directed the annual Aeronautics and Space Report to include a comprehensive description of the programmed activities and the accomplishments of all agencies of the United States in the field of aeronautics and space activities during the preceding calendar year. In recent years, the reports have been prepared on a fiscal-year basis, consistent with the budgetary period now used in programs of the Federal Government. This year's report covers activities that took place from October 1, 2002, through September 30, 2003.

Aeronautics and Space Report of the President: Fiscal Year 2000 Activities

NASA Technical Reports Server (NTRS)

2000-01-01

The National Aeronautics and Space Act of 1958 directed the annual Aeronautics and Space Report to include a "comprehensive description of the programmed activities and the accomplishments of all agencies of the United States in the field of aeronautics and space activities during the preceding calendar year." In recent years, the reports have been prepared on a fiscal year basis, consistent with the budgetary period now used in programs of the Federal Government. This year's report covers activities that took place from October 1, 1999, through September 30, 2000.

Aeronautics and Space Report of the President: Fiscal Year 2007 Activities

NASA Technical Reports Server (NTRS)

2009-01-01

The National Aeronautics and Space Act of 1958 directed the annual Aeronautics and Space Report to include a "comprehensive description of the programmed activities and the accomplishments of all agencies of the United States in the field of aeronautics and space activities during the preceding calendar year." In recent years, the reports have been prepared on a fiscal-year basis, consistent with the budgetary period now used in programs of the Federal Government. This year's report covers activities that took place from October 1, 2006, through September 30, 2007.

Aeronautics and Space Report of the President - Fiscal Year 2008 Activities

NASA Technical Reports Server (NTRS)

2009-01-01

The National Aeronautics and Space Act of 1958 directed the annual Aeronautics and Space Report to include a "comprehensive description of the programmed activities and the accomplishments of all agencies of the United States in the field of aeronautics and space activities during the preceding calendar year." In recent years, the reports have been prepared on a fiscal-year basis, consistent with the budgetary period now used in programs of the Federal Government. This year's report covers activities that took place from October 1, 2007, through September 30, 2008.

Aeronautics and Space Report of the President - Fiscal Year 2010 Activities

NASA Technical Reports Server (NTRS)

2011-01-01

The National Aeronautics and Space Act of 1958 directed the annual Aeronautics and Space Report to include a "comprehensive description of the programmed activities and the accomplishments of all agencies of the United States in the field of aeronautics and space activities during the preceding calendar year." In recent years, the reports have been prepared on a fiscal-year basis, consistent with the budgetary period now used in programs of the Federal Government. This year's report covers activities that took place from October 1, 2009, through September 30, 2010.

Aeronautics and Space Report of the President: Fiscal Year 1999 Activities

NASA Technical Reports Server (NTRS)

1999-01-01

The National Aeronautics and Space Act of 1958 directed the annual Aeronautics and Space Report to include a "comprehensive description of the programmed activities and the accomplishments of all agencies of the United States in the field of aeronautics and space activities during the preceding calendar year." In recent years, the reports have been prepared on a fiscal year basis, consistent with the budgetary period now used in programs of the Federal Government. This year's report covers activities that took place from October 1, 1998, through September 30, 1999.

Aeronautical Engineering: A Continuing Bibliography with Indexes, Supplement 410. Supplement 410

NASA Technical Reports Server (NTRS)

1999-01-01

This supplemental issue of Aeronautical Engineering, A Continuing Bibliography with Indexes (NASA/SP-1999-7037) lists reports, articles, and other documents recently announced in the NASA STI Database. The coverage includes documents on the engineering and theoretical aspects of design, construction, evaluation, testing, operation, and performance of aircraft (including aircraft engines) and associated components, equipment, and systems. It also includes research and development in aerodynamics, aeronautics, and ground support equipment for aeronautical vehicles. Each entry in the publication consists of a standard bibliographic citation accompanied, in most cases, by an abstract.

Factors related to ostomy leakage in the community setting.

PubMed

Ratliff, Catherine R

2014-01-01

The purpose of this study was to describe demographic and clinical variables related to ostomy pouch leakage from those discharged from a major medical center during a 2-year period. A convenience sample of 198 persons with an ostomy was obtained using the ICD-9 (International Classification of Diseases, Ninth Revision) codes for colostomy, ileostomy, and ileal conduit for patients who were discharged from the medical center within the time frame of July 2009 to July 2011. One hundred seven participants (55%) returned a completed survey. Respondents included 57 men (53%) and 50 women (47%). The mean age was 60 years with age range from 23 to 91 years. Fecal ostomies made up the majority of the stomas representing 71 patients (66%). A descriptive, cross-sectional research design was used to describe clinical variables related to ostomy pouch leakage for those discharged from a major academic medical center over a 2-year period of time. Participants were mailed an introductory letter from the principal investigator, a self-administered questionnaire, and a prepaid return envelope. Ninety-three patients (87%) reported leakage; however, 48 patients (45%) stated that they did not leak often. A logistic regression was estimated to determine which variables were significant predictors of the dependent variable of leaking status (no/seldom leaking vs more frequent leaking). Two variables were individually significant predictors, sex (P = .021) and 2-piece pouch (P = .015). Women were 4 times more likely to be in the more frequent leaking group than were men. Those who were wearing 2-piece pouches were 78% less likely to be in the more frequent leaking group. Participants with ileostomies or urostomies were more likely to be in the more frequent leaking group and those with peristomal skin irritation were more likely to be in the more frequent leaking group. Findings from this study reveal that women were more likely to experience leakage than men and that wearing a 2-piece

14 CFR 398.5 - Frequency of flights.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Frequency of flights. 398.5 Section 398.5... flights. (a) Except in Alaska, at least two round trips each weekday and two round trips each weekend. (b...; (2) More flights are needed because the capacity available to the eligible place is being shared with...

14 CFR 398.5 - Frequency of flights.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Frequency of flights. 398.5 Section 398.5... flights. (a) Except in Alaska, at least two round trips each weekday and two round trips each weekend. (b...; (2) More flights are needed because the capacity available to the eligible place is being shared with...

14 CFR 398.5 - Frequency of flights.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Frequency of flights. 398.5 Section 398.5... flights. (a) Except in Alaska, at least two round trips each weekday and two round trips each weekend. (b...; (2) More flights are needed because the capacity available to the eligible place is being shared with...

14 CFR 398.5 - Frequency of flights.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Frequency of flights. 398.5 Section 398.5... flights. (a) Except in Alaska, at least two round trips each weekday and two round trips each weekend. (b...; (2) More flights are needed because the capacity available to the eligible place is being shared with...

NASA's Role in Aeronautics: A Workshop. Volume VII - Background Papers.

ERIC Educational Resources Information Center

National Academy of Sciences - National Research Council, Washington, DC. Assembly of Engineering.

Sixteen background papers presented to a plenary session at a 1980 workshop on the role of the National Aeronautics and Space Administration (NASA) in aeronautics are presented. The central task of the workshop was to examine the relationship of NASA's research capabilities to the state of U.S. aviation and to make recommendations about NASA's…

An objective comparison of leakage between commonly used earplugs.

PubMed

Alt, Jeremiah A; Collins, William O

2012-01-01

We sought to determine the efficacy of commonly used earplugs using an anatomically correct ear model. The total volume and rate of water that leaked past the earplug and subsequent defect in the tympanic membrane over separately measured 30, 60, 120, and 180-second intervals were recorded. Scenarios tested included a control with no earplug, custom molded earplug (Precision Laboratories, Orlando, FL), Mack's plug (Warren, MI), Doc's plug (Santa Cruz, CA), and cotton balls coated with petroleum jelly. All plugs tested resulted in less leakage at all time points when compared with no plug (P < .05). At 30 seconds, the custom molded, Mack's and Doc's plugs all showed significantly less leakage when compared with the cotton ball coated with petroleum jelly (P < .05). At 60, 120, and 180 seconds, Mack's, Doc's, and the cotton plugs all showed significantly less leakage compared with the customized plug (P < .05). At 120 and 180 seconds, Mack's plugs had significant less leakage than the cotton plug (P < .05). Among the types of plugs, the molded variety (Mack's) showed the least volume and lowest leakage rate (f(4,45) = 94 [P < .001]). In addition, Doc's and cotton balls coated with petroleum jelly were more effective than the customized earplugs. If the clinician feels that middle ear and external canal water exposure should be minimized, then use of earplugs, particularly the moldable variety, merits further consideration. Copyright © 2012 Elsevier Inc. All rights reserved.

Thrombogenic potential of transcatheter aortic valve implantation with trivial paravalvular leakage

PubMed Central

Siegel, Rolland

2014-01-01

Background Significant paravalvular leakage after transcatheter aortic valve implantation (TAVI) correlates with increased morbidity and mortality, but adverse consequences of trivial paravalvular leakage have stimulated few investigations. Using a unique method distinctly different from other diagnostic approaches, we previously reported elevated backflow velocities of short duration (transients) in mechanical valve closure. In this study, similar transients were found in a transcatheter valve paravalvular leakage avatar. Methods Paravalvular leakage rate (zero to 58 mL/second) and aortic valve incompetence (volumetric back flow/forward flow; zero to 32%) were made adjustable using a mock transcatheter aortic valve device and tested in quasi-steady and pulsatile flow test systems. Projected dynamic valve area (PDVA) from the back illuminated mock transcatheter aortic valve device was measured and regional backflow velocities were derived by dividing volumetric flow rate by the PDVA over the open and closing valve phase and the total closed valve area derived from backflow leakage. Results Aortic incompetence from 1-32% generated negative backflow transients from 8 to 267 meters/second, a range not dissimilar to that measured in mechanical valves with zero paravalvular leakage. Optimal paravalvular leakage was identified; not too small generating high backflow transients, not too large considering volume overload and cardiac energy loss caused by defective valve behavior and fluid motion. Conclusions Thrombogenic potential of transcatheter aortic valves with trivial aortic incompetence and high magnitude regional backflow velocity transients was comparable to mechanical valves. This may have relevance to stroke rate, asymptomatic microembolic episodes and indications for anticoagulation therapy after transcatheter valve insertion. PMID:25333018

14 CFR 61.185 - Aeronautical knowledge.

Code of Federal Regulations, 2014 CFR

2014-01-01

...) AIRMEN CERTIFICATION: PILOTS, FLIGHT INSTRUCTORS, AND GROUND INSTRUCTORS Flight Instructors Other than Flight Instructors With a Sport Pilot Rating § 61.185 Aeronautical knowledge. (a) A person who is applying for a flight instructor certificate must receive and log ground training from an authorized...

14 CFR 61.185 - Aeronautical knowledge.

Code of Federal Regulations, 2012 CFR

2012-01-01

...) AIRMEN CERTIFICATION: PILOTS, FLIGHT INSTRUCTORS, AND GROUND INSTRUCTORS Flight Instructors Other than Flight Instructors With a Sport Pilot Rating § 61.185 Aeronautical knowledge. (a) A person who is applying for a flight instructor certificate must receive and log ground training from an authorized...

14 CFR 61.185 - Aeronautical knowledge.

Code of Federal Regulations, 2013 CFR

2013-01-01

...) AIRMEN CERTIFICATION: PILOTS, FLIGHT INSTRUCTORS, AND GROUND INSTRUCTORS Flight Instructors Other than Flight Instructors With a Sport Pilot Rating § 61.185 Aeronautical knowledge. (a) A person who is applying for a flight instructor certificate must receive and log ground training from an authorized...

Experiment In Aeronautical-Mobile/Satellite Communication

NASA Technical Reports Server (NTRS)

Jedrey, Thomas C.; Lay, Norman E.; Dessouky, Khaled

1992-01-01

Report describes study of performance of digital mobile/satellite communication terminals of advanced design intended for use in ground stations and airplanes in aeronautical-mobile service. Study was collaboration of NASA, Federal Aviation Administration (FAA), Communications Satellite Corp. (COMSAT), and International Maritime Satellite System (INMARSAT).

Center for Aeronautics and Space Information Sciences

NASA Technical Reports Server (NTRS)

Flynn, Michael J.

1992-01-01

This report summarizes the research done during 1991/92 under the Center for Aeronautics and Space Information Science (CASIS) program. The topics covered are computer architecture, networking, and neural nets.

Estimation of steady-state leakage current in polycrystalline PZT thin films

NASA Astrophysics Data System (ADS)

Podgorny, Yury; Vorotilov, Konstantin; Sigov, Alexander

2016-09-01

Estimation of the steady state (or "true") leakage current Js in polycrystalline ferroelectric PZT films with the use of the voltage-step technique is discussed. Curie-von Schweidler (CvS) and sum of exponents (Σ exp ) models are studied for current-time J (t) data fitting. Σ exp model (sum of three or two exponents) gives better fitting characteristics and provides good accuracy of Js estimation at reduced measurement time thus making possible to avoid film degradation, whereas CvS model is very sensitive to both start and finish time points and give in many cases incorrect results. The results give rise to suggest an existence of low-frequency relaxation processes in PZT films with characteristic duration of tens and hundreds of seconds.

Aeronautics and Space Report of the President

NASA Technical Reports Server (NTRS)

1990-01-01

Nineteen eighty-eight marked the United States' return to space flight with two successful space shuttle launches in September and December, as well as six successful expendable rocket launches. Meanwhile, many other less spectacular but important contributions were made in aeronautics and space by the 14 participating government organizations. Each organization's aeronautics and/or space activities for the year are presented. The organizations involved include: (1) NASA; (2) Department of Defense; (3) Department of Commerce; (4) Department of Energy; (5) Department of the Interior; (6) Department of Agriculture; (7) Federal Communications Commission; (8) Department of Transportation; (9) Environmental Protection Agency; (10) National Science Foundation; (11) Smithsonian Institution; (12) Department of State; (13) Arms Control and Disarmament Agency; and (14) United States Information Agency.

Aeronautical Engineering: A Continuing Bibliography with Indexes. Supplement 397

NASA Technical Reports Server (NTRS)

1999-01-01

This report lists reports, articles and other documents recently announced in the NASA STI Database. The coverage includes documents on the engineering and theoretical aspects of design, construction, evaluation, testing, operation, and performance of aircraft (including aircraft engines) and associated components, equipment, and systems. It also includes research and development in aerodynamics, aeronautics, and ground support equipment for aeronautical vehicles. Each entry in the publication consists of a standard bibliographic citation accompanied, in most cases, by an abstract.

Evaluation of Corrective Action Team (CAT) Leader Training in Aeronautical Systems Division

DTIC Science & Technology

1991-09-01

00A DI EVALUATION OF CORRECTIVE ACTION TEAM ( CAT ) LEADER TRAINING IN AERONAUTICAL SYSTEMS DIVISION CA THESIS Kirk J. Streitrater, Captain, USAF AFIT...EVALUATION OF CORRECTIVE ACTION TEAM ( CAT ) LEADER TRAINING IN AERONAUTICAL SYSTEMS DIVISION THESIS Kirk J. Streitmater, Captain, USAF AFIT/GSM/LSR/91S-25...8217, , C- s :C AFIT/GSM/LSR/91S-25 EVALUATION OF CORRECTIVE ACTION TEAM ( CAT ) LEADER TRAINING IN AERONAUTICAL SYSTEMS DIVISION THESIS Presented to the

Application of the Iridium Satellite System to Aeronautical Communications

NASA Technical Reports Server (NTRS)

Kerczewski, Robert J.; Meza, Mike; Gupta, Om

2008-01-01

The next generation air transportation system will require greater air-ground communications capacity to accommodate more air traffic with increased safety and efficiency. Communications will remain primarily terrestrially based, but satellite communications will have an increased role. Inmarsat s aeronautical services have been approved and are in use for aeronautical safety communications provided by geostationary satellites. More recently the approval process for the Iridium low earth orbit constellation is nearing completion. The current Iridium system will be able to provide basic air traffic services communications suitable for oceanic, remote and polar regions. The planned second generation of the Iridium system, called Iridium NEXT, will provide enhanced capabilities and enable a greater role in the future of aeronautical communications. This paper will review the potential role of satellite communications in the future of air transportation, the Iridium approval process and relevant system testing, and the potential role of Iridium NEXT.

Liquid radwaste in-leakage reduction at TVA's Browns Ferry nuclear plant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, A.C.; Roccasano, J.J.

1987-01-01

Early in 1985, Tennessee Valley Authority's (TVA's) Browns Ferry Nuclear Plant (BFNP) decided to initiate a liquid radwaste in-leakage reduction project as part of their chemistry improvement program. The purpose of this project was to reduce the overall volume of water processed by the radwaste system at BFNP by restricting uncontrolled in-leakage through the floor drain system. Impell Corporation was contracted to perform the project, which consisted of several tasks, each design to provide data for the reduction of in-leakage or to reduce the in-leakage directly. The program was begun in March 1985. Buy July of that same year, liquidmore » input to radwaste through the floor drain system had been reduced by --30%.« less

National Aeronautics Research and Development Plan

DTIC Science & Technology

2010-02-01

aeronautics research to improve aviation safety, air transportation, and reduce the environmental impacts of aviation; • Promotes the advancement of fuel...Reduce the Adverse Impacts of Weather on Air Traffic Management Decisions...Operational Procedures to Decrease the Significant Environmental Impacts of the Aviation System. . . 42 Future Implementation

Feasibility of Locating Leakages in Sewage Pressure Pipes Using the Distributed Temperature Sensing Technology.

PubMed

Apperl, Benjamin; Pressl, Alexander; Schulz, Karsten

2017-01-01

The cost effective maintenance of underwater pressure pipes for sewage disposal in Austria requires the detection and localization of leakages. Extrusion of wastewater in lakes can heavily influence the water and bathing quality of surrounding waters. The Distributed Temperature Sensing (DTS) technology is a widely used technique for oil and gas pipeline leakage detection. While in pipeline leakage detection, fiber optic cables are installed permanently at the outside or within the protective sheathing of the pipe; this paper aims at testing the feasibility of detecting leakages with temporary introduced fiber optic cable inside the pipe. The detection and localization were tested in a laboratory experiment. The intrusion of water from leakages into the pipe, producing a local temperature drop, served as indicator for leakages. Measurements were taken under varying measurement conditions, including the number of leakages as well as the positioning of the fiber optic cable. Experiments showed that leakages could be detected accurately with the proposed methodology, when measuring resolution, temperature gradient and measurement time were properly selected. Despite the successful application of DTS for leakage detection in this lab environment, challenges in real system applications may arise from temperature gradients within the pipe system over longer distances and the placement of the cable into the real pipe system.

75 FR 63534 - Seventh Meeting-Special Committee 222: Inmarsat Aeronautical Mobile Satellite (Route) Services

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-15

... 222: Inmarsat Aeronautical Mobile Satellite (Route) Services AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of RTCA Special Committee 222: Inmarsat Aeronautical Mobile Satellite (Route... Committee 222: Inmarsat Aeronautical Mobile Satellite (Route) Services. DATES: The meeting will be held...

75 FR 15770 - Fifth Meeting-Special Committee 222: Inmarsat Aeronautical Mobile Satellite (Route) Services

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-30

...: Inmarsat Aeronautical Mobile Satellite (Route) Services AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of RTCA Special Committee 222: Inmarsat Aeronautical Mobile Satellite (Route) Services... Committee 222: Inmarsat Aeronautical Mobile Satellite (Route) Services. DATES: The meeting will be held...

75 FR 39724 - Sixth Meeting-Special Committee 222: Inmarsat Aeronautical Mobile Satellite (Route) Services

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-12

...: Inmarsat Aeronautical Mobile Satellite (Route) Services AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of RTCA Special Committee 222: Inmarsat Aeronautical Mobile Satellite (Route) Services... Committee 222: Inmarsat Aeronautical Mobile Satellite (Route) Services. DATES: The meeting will be held...

The Western Aeronautical Test Range of NASA Ames Research Center

NASA Technical Reports Server (NTRS)

Moore, A. L.

1984-01-01

An overview of the Western Aeronautical Test Range (WATR) of NASA Ames Research Center (ARC) is presented in this paper. The three WATR facilities are discussed, and three WATR elements - mission control centerns, communications systems, real-time processing and display systems, and tracking systems -are reviewed. The relationships within the NASA WATR, with respect to the NASA aeronautics program, are also discussed.

A Vision in Aeronautics: The K-12 Wind Tunnel Project

NASA Technical Reports Server (NTRS)

1997-01-01

A Vision in Aeronautics, a project within the NASA Lewis Research Center's Information Infrastructure Technologies and Applications (IITA) K-12 Program, employs small-scale, subsonic wind tunnels to inspire students to explore the world of aeronautics and computers. Recently, two educational K-12 wind tunnels were built in the Cleveland area. During the 1995-1996 school year, preliminary testing occurred in both tunnels.

Martian neutron leakage spectra

NASA Astrophysics Data System (ADS)

Drake, D. M.; Feldman, W. C.; Jakosky, B. M.

1988-06-01

A high-energy nucleon-meson transport code is used to calculate energy spectra of Martian leakage neutrons. Four calculations are used to simulate a uniform surface layer containing various amounts of water, different burial depths of a 50 percent water layer underneath a 1 percent water layer, changing atmospheric pressure, and a thick carbon dioxide ice sheet overlying a "dirty" water ice sheet. Calculated spectra at energies less than about 1000 eV were fitted by a superposition of thermal and epithermal functions having four free parameters, two of which (thermal and epithermal amplitudes) were found to vary systematically and to specify uniquely the configuration in each of the series. Parameter variations depend on the composition of the assumed surface layers through the average atomic mass and the macroscopic scattering and absorption cross sections. It is concluded that measurements of leakage neutron spectra should allow determination of the hydrogen content of surface layers buried to depths up to about 100 g/sq. cm and determination of the thickness of a polar dry ice cap up to a thickness of about 250 g/sq. cm.

NASA's Role in Aeronautics: A Workshop. Volume 2: Military aviation

NASA Technical Reports Server (NTRS)

1981-01-01

While the National Aeronautics and Space Act of 1958 makes DOD primarily responsible for military aeronautics, it stipulates a role for NASA in providing direct and indirect support for national defense. The existing role of NASA in support of military aeronautics is working well and is well coordinated. The role needs only to be kept effective and then improved by increasing its responsiveness to changing military requirements and by the selective application of additional people. Funding resources should also be made available to NASA for research. Specific roles that NASA could or should play were examined. It was determined that the most important areas for this support are in basic research, generic technology evolution, and facility support in the fields of aerodynamics, structures and materials, and propulsion.

Non-invasive dynamic near-infrared imaging and quantification of vascular leakage in vivo.

PubMed

Proulx, Steven T; Luciani, Paola; Alitalo, Annamari; Mumprecht, Viviane; Christiansen, Ailsa J; Huggenberger, Reto; Leroux, Jean-Christophe; Detmar, Michael

2013-07-01

Preclinical vascular research has been hindered by a lack of methods that can sensitively image and quantify vascular perfusion and leakage in vivo. In this study, we have developed dynamic near-infrared imaging methods to repeatedly visualize and quantify vascular leakage in mouse skin in vivo, and we have applied these methods to transgenic mice with overexpression of vascular endothelial growth factors VEGF-A or -C. Near-infrared dye conjugates were developed to identify a suitable vascular tracer that had a prolonged circulation lifetime and slow leakage into normal tissue after intravenous injection. Dynamic simultaneous imaging of ear skin and a large blood vessel in the leg enabled determination of the intravascular signal (blood volume fraction) from the tissue signal shortly after injection and quantifications of vascular leakage into the extravascular tissue over time. This method allowed for the sensitive detection of increased blood vascularity and leakage rates in K14-VEGF-A transgenic mice and also reliably measured inflammation-induced changes of vascularity and leakage over time in the same mice. Measurements after injection of recombinant VEGF-A surprisingly revealed increased blood vascular leakage and lymphatic clearance in K14-VEGF-C transgenic mice which have an expanded cutaneous lymphatic vessel network, potentially indicating unanticipated effects of lymphatic drainage on vascular leakage. Increased vascular leakage was also detected in subcutaneous tumors, confirming that the method can also be applied to deeper tissues. This new imaging method might facilitate longitudinal investigations of the in vivo effects of drug candidates, including angiogenesis inhibitors, in preclinical disease models.

Non-invasive dynamic near-infrared imaging and quantification of vascular leakage in vivo

PubMed Central

Proulx, Steven T.; Luciani, Paola; Alitalo, Annamari; Mumprecht, Viviane; Christiansen, Ailsa J.; Huggenberger, Reto

2013-01-01

Preclinical vascular research has been hindered by a lack of methods that can sensitively image and quantify vascular perfusion and leakage in vivo. In this study, we have developed dynamic near-infrared imaging methods to repeatedly visualize and quantify vascular leakage in mouse skin in vivo, and we have applied these methods to transgenic mice with overexpression of vascular endothelial growth factors VEGF-A or -C. Near-infrared dye conjugates were developed to identify a suitable vascular tracer that had a prolonged circulation lifetime and slow leakage into normal tissue after intravenous injection. Dynamic simultaneous imaging of ear skin and a large blood vessel in the leg enabled determination of the intravascular signal (blood volume fraction) from the tissue signal shortly after injection and quantifications of vascular leakage into the extravascular tissue over time. This method allowed for the sensitive detection of increased blood vascularity and leakage rates in K14-VEGF-A transgenic mice and also reliably measured inflammation-induced changes of vascularity and leakage over time in the same mice. Measurements after injection of recombinant VEGF-A surprisingly revealed increased blood vascular leakage and lymphatic clearance in K14-VEGF-C transgenic mice which have an expanded cutaneous lymphatic vessel network, potentially indicating unanticipated effects of lymphatic drainage on vascular leakage. Increased vascular leakage was also detected in subcutaneous tumors, confirming that the method can also be applied to deeper tissues. This new imaging method might facilitate longitudinal investigations of the in vivo effects of drug candidates, including angiogenesis inhibitors, in preclinical disease models. PMID:23325334

Improved Steam Turbine Leakage Control with a Brush Seal Design

NASA Astrophysics Data System (ADS)

Turnquist, Norman; Chupp, Raymond E.; Pastrana, Ryan; Wolfe, Chris; Burnett, Mark

2002-10-01

This paper presents an improved steam turbine leakage control system with a brush seal design. The contents include: 1) Typical Design Characteristics; 2) Typical Brush Seal Locations; 3) Reduced Leakage Rates; 4) Performance Benefits; 5) System Considerations; 6) Rotor Dynamics; 7) Laboratory Tests and 8) Field Experience.

Reinforced glass-ionomer cements: the influence of conditioners on marginal leakage.

PubMed

Yap, A U; Mok, B Y

1997-06-01

The purpose of this in vitro study was to evaluate the influence of conditioners on the enamel and dentine margin sealing ability of three different reinforced glass-ionomer cements. Two Class V preparations were made on the buccal and lingual surfaces of 36 freshly extracted molar teeth. Preparations were solely in enamel or dentine/cementum. The teeth were randomly divided into three groups of 12 and restored with either Ketac Silver (KS), Hi-Dense (HD) or Miracle-Mix (MM) with and without (-C) their respective conditioners. All materials were capsulated and were manipulated according to the manufacturers' instructions. The restorations were finished as recommended by the manufacturers and then stored in saline at 37 degrees C for 1 week, polished, thermally stressed, subjected to dye penetration, sectioned and scored. Rankings in the order of decreasing leakage were as follows: enamel margin KS > KS-C > HD-C > HD > MM > MM-C; dentine margin KS > HD-C > KS-C > HD > MM-C > MM. At the enamel margins, only HD showed a significant increase in leakage when conditioner was not used. At the dentine margin, however, KS had significantly more leakage than KS-C and HD-C had significantly more leakage than HD. There was no significant difference in leakage for MM both with and without conditioner. The influence of conditioners on marginal leakage appears to be both product and tissue specific.

Ray-leakage-free discal solar concentrators of a novel design

NASA Astrophysics Data System (ADS)

Yin, Peng; Xu, Xiping; Jiang, Zhaoguo; Hai, Yina

2017-12-01

For high concentration ratio of the planar concentrator which is mainly used for photovoltaic or solar-thermal applications, the ray-leakage must be prevented during rays propagated in the lightguide. In this paper, the design of a ray-leakage-free discal solar concentrator is proposed which provides a high concentration ratio while acquiring a high optical efficiency. The design structure of the coupling structure is a straightforward hemisphere instead of complicated structure in other concentrators because the emergent rays from the hybrid collectors have any tilt angle, which prompts the ray-leakage-free propagating length can be raised greatly. A mathematical model between geometrical concentration ratio, reflection times and the corresponding parameters is established, where the corresponding parameters include the parabola coefficient, outermost collector width, collector height, the expanding angle and the collector quantity. Numerical simulation results show that more than 1200x geometrical concentration ratio of the proposed concentrator is achieved without any leakage from the lightguide.

Impact of leakage delay on bifurcation in high-order fractional BAM neural networks.

PubMed

Huang, Chengdai; Cao, Jinde

2018-02-01

The effects of leakage delay on the dynamics of neural networks with integer-order have lately been received considerable attention. It has been confirmed that fractional neural networks more appropriately uncover the dynamical properties of neural networks, but the results of fractional neural networks with leakage delay are relatively few. This paper primarily concentrates on the issue of bifurcation for high-order fractional bidirectional associative memory(BAM) neural networks involving leakage delay. The first attempt is made to tackle the stability and bifurcation of high-order fractional BAM neural networks with time delay in leakage terms in this paper. The conditions for the appearance of bifurcation for the proposed systems with leakage delay are firstly established by adopting time delay as a bifurcation parameter. Then, the bifurcation criteria of such system without leakage delay are successfully acquired. Comparative analysis wondrously detects that the stability performance of the proposed high-order fractional neural networks is critically weakened by leakage delay, they cannot be overlooked. Numerical examples are ultimately exhibited to attest the efficiency of the theoretical results. Copyright © 2017 Elsevier Ltd. All rights reserved.

In vitro and ex vivo microbial leakage assessment in endodontics: A literature review.

PubMed

Savadkouhi, Sohrab Tour; Bakhtiar, Hengameh; Ardestani, Safoura Emami

2016-01-01

The aim of this study was to perform a literature review of published in-vitro and ex-vivo studies, which evaluated microbial leakage in endodontics in the past 10 years. A comprehensive electronic literature search was carried out in PubMed database for English articles published from 2005 to 2016 using the keywords "endodontics," " in vitro ," " ex vivo ," "microbial leakage," "microbial penetration," "saliva," " Enterococcus faecalis ," " E. faecalis ," "endodontic sealers," "temporary filling material," "apical plug," "mineral trioxide aggregate," and "MTA." The keywords were combined using Boolean operators AND/OR. Based on our search strategy, 33 relevant articles were included in the study. There are three main methods for assessment of bacterial microleakage, namely, (A) the dual-chamber leakage model, (B) detection of bacteria using a scanning electron microscope (SEM), and (C) polymerase chain reaction. All bacterial leakage models have some limitations and may yield different results compared to other microleakage evaluation techniques (i.e., dye penetration, fluid filtration, or electrochemical tests). The results of SEM correlated with those of microbial leakage test in most studies. Microbial leakage test using saliva better simulates the clinical setting for assessment of the leakage of single or mixed bacterial species.

Pilot identification of proposed electronic symbols for displays of aeronautical charting information

DOT National Transportation Integrated Search

2007-10-05

Many electronic displays of aeronautical charting information currently use different symbols for common display elements, creating the risk of confusion and misinterpretation. The SAE International Aerospace Behavior and Technology (G-10) Aeronautic...

Achieving QoS for Aeronautical Telecommunication Networks Over Differentiated Services

NASA Technical Reports Server (NTRS)

Bai, Haowei; Atiquzzaman, Mohammed; Ivanic, William

2001-01-01

Aeronautical Telecommunication Network (ATN) has been developed by the International Civil Aviation Organization to integrate Air-Ground and Ground-Ground data communication for aeronautical applications into a single network serving Air Traffic Control and Aeronautical Operational Communications. To carry time critical information required for aeronautical applications, ATN provides different Quality of Services (QoS) to applications. ATN has therefore, been designed as a stand alone network which implies building an expensive separate network for ATN However, the cost of operating ATN can be reduced if it can be run over a public network such as the Internet. Although the current Internet does not provide QoS the next generation Internet is expected to provide QoS to applications. The objective of this paper is to investigate the possibility of providing QoS to ATN applications when it is run over the next generation Internet. Differentiated Services (DiffServ), one of the protocols proposed for the next generation Internet, will allow network service providers to offer different QoS to customers. Our results show that it is possible to provide QoS to ATN applications when they run over a DiffServ backbone.

Achieving QoS for Aeronautical Telecommunication Networks over Differentiated Services

NASA Technical Reports Server (NTRS)

Bai, Haowei; Atiquzzaman, Mohammed; Ivancic, William

2001-01-01

Aeronautical Telecommunication Network (ATN) has been developed by the International Civil Aviation Organization to integrate Air-Ground and Ground-Ground data communication for aeronautical applications into a single network serving Air Traffic Control and Aeronautical Operational Communications. To carry time critical information required for aeronautical applications, ATN provides different Quality of Services (QoS) to applications. ATN has therefore, been designed as a standalone network which implies building an expensive separate network for ATN. However, the cost of operating ATN can be reduced if it can be run over a public network such as the Internet. Although the current Internet does not provide QoS, the next generation Internet is expected to provide QoS to applications. The objective of this paper is to investigate the possibility of providing QoS to ATN applications when it is run over the next generation Internet. Differentiated Services (DiffServ), one of the protocols proposed for the next generation Internet, will allow network service providers to offer different QoS to customers. Our results show that it is possible to provide QoS to ATN applications when they run over a DiffServ backbone.

[Anastomotic leakage after laparoscopic-assisted radical right hemicolectomy: reason analysis and management].

PubMed

Wu, Xin; Lin, Guole; Qiu, Huizhong; Xiao, Yi; Wu, Bin

2017-06-25

To analyze the clinical features, possible reasons and management of anastomotic leakage after laparoscopic-assisted radical right hemicolectomy. Clinical data of 546 patients undergoing laparoscopic-assisted radical right hemicolectomy in Peking Union Medical College Hospital from October 2010 to September 2016 were retrospectively analyzed. The occurrence of anastomotic leakage and its countermeasures were evaluated. Among 546 patients, 8(1.5%) cases developed anastomotic leakage, including 7 males and 1 female with mean age of (54.3±10.3) years. Six cases of ascending colon cancer, 1 case of phlegmon and 1 case of arterior-venous malformation were confirmed after operation. The incidence of anastomotic leakage after D3 and D2 lymphadenectomy was 2.1%(6/290) and 0.8%(2/256). The time from operation to the diagnosis of anastomotic leakage was (6.6±3.6) days. The clinical manifestation of anastomotic leakage were stool-like drainage in 7 patients, fever in 4 and abdominal pain in 3. Amylase and bilirubin in drainage of 4 patients increased obviously. All the 8 patients underwent secondary ileostomy, including 4 with laparoscopy and 4 with laparotomy. One patient suffered from respiratory failure after re-operation because of severe abdominal infection and was cured by ventilator support treatment. Another one had pelvic encapsulated effusion and was treated by puncture drainage. All the patients discharged from hospital smoothly. Anastomotic leakage after laparoscopic-assisted right hemicolectomy is a quite rare but serious complication, which may be associated with over-cleaning of lymph fatty tissues. Ileostomy should be the first choice of anastomotic leakage after laparoscopy-assisted right hemicolectomy and its efficacy is satisfactory.

Atrial Natriuretic Peptide Reduces Vascular Leakage and Choroidal Neovascularization

PubMed Central

Lara-Castillo, Nuria; Zandi, Souska; Nakao, Shintaro; Ito, Yasuhiro; Noda, Kousuke; She, Haicheng; Ahmed, Muna; Frimmel, Sonja; Ablonczy, Zsolt; Hafezi-Moghadam, Ali

2009-01-01

Atrial natriuretic peptide (ANP) is a hormone with diuretic, natriuretic, and vasodilatory properties. ANP blocks vascular endothelial growth factor (VEGF) production and signaling in vitro; however, its role in vascular leakage and angiogenesis is unknown. In vitro, retinal barrier permeability (transepithelial electrical resistance (TEER)) was measured in cultured retinal endothelial (HuREC) and retinal epithelial (ARPE-19) cells with VEGF (10 ng/ml), ANP (1 pM to 1 μmol/L), and/or isatin, an ANP receptor antagonist. In vivo, blood-retinal barrier (BRB) leakage was studied using the Evans Blue dye technique in rats treated with intravitreal injections of ANP, VEGF, or vehicle. Choroidal neovascularization was generated by laser injury, and 7 days later, lesion size and leakage was quantitated. ANP significantly reversed VEGF-induced BRB TEER reduction in both HuREC and ARPE-19 cells, modeling the inner and the outer BRB, respectively. Isatin, a specific ANP receptor antagonist, reversed ANP’s effect. ANP reduced the response of ARPE-19 cells to VEGF apically but not basolaterally, suggesting polarized expression of the ANP receptors in these cells. ANP’s TEER response was concentration but not time dependent. In vivo, ANP significantly reduced VEGF-induced BRB leakage and the size of laser-induced choroidal neovascularization lesions. In sum, ANP is an effective inhibitor of VEGF-induced vascular leakage and angiogenesis in vivo. These results may lead to new treatments for ocular diseases where VEGF plays a central role, such as age-related macular degeneration or diabetic retinopathy. PMID:19910509

Cholesterol suppresses membrane leakage by decreasing water penetrability.

PubMed

Bu, Bing; Crowe, Michael; Diao, Jiajie; Ji, Baohua; Li, Dechang

2018-06-13

Membrane fusion is a fundamental biological process that lies at the heart of enveloped virus infection, synaptic signaling, intracellular vesicle trafficking, gamete fertilization, and cell-cell fusion. Membrane fusion is initiated as two apposed membranes merge to a single bilayer called a hemifusion diaphragm. It is believed that the contents of the two fusing membranes are released through a fusion pore formed at the hemifusion diaphragm, and yet another possible pathway has been proposed in which an undefined pore may form outside the hemifusion diaphragm at the apposed membranes, leading to the so-called leaky fusion. Here, we performed all-atom molecular dynamics simulations to study the evolution of the hemifusion diaphragm structure with various lipid compositions. We found that the lipid cholesterol decreased water penetrability to inhibit leakage pore formation. Biochemical leakage experiments support these simulation results. This study may shed light on the underlying mechanism of the evolution pathways of the hemifusion structure, especially the understanding of content leakage during membrane fusion.

Insulation Resistance and Leakage Currents in Low-Voltage Ceramic Capacitors with Cracks

NASA Technical Reports Server (NTRS)

Teverovsky, Alexander A.

2014-01-01

Measurement of insulation resistance (IR) in multilayer ceramic capacitors (MLCCs) is considered a screening technique that ensures the dielectric is defect-free. This work analyzes the effectiveness of this technique for revealing cracks in ceramic capacitors. It is shown that absorption currents prevail over the intrinsic leakage currents during standard IR measurements at room temperature. Absorption currents, and consequently IR, have a weak temperature dependence, increase linearly with voltage (before saturation), and are not sensitive to the presence of mechanical defects. In contrary, intrinsic leakage currents increase super-linearly with voltage and exponentially with temperature (activation energy is in the range from 0.6 eV to 1.1 eV). Leakage currents associated with the presence of cracks have a weaker dependence on temperature and voltage compared to the intrinsic leakage currents. For this reason, intrinsic leakage currents prevail at high temperatures and voltages, thus masking the presence of defects.

Insulation Resistance and Leakage Currents in Low-Voltage Ceramic Capacitors with Cracks

NASA Technical Reports Server (NTRS)

Teverovsky, Alexander A.

2016-01-01

Measurement of insulation resistance (IR) in multilayer ceramic capacitors (MLCCs) is considered a screening technique that ensures the dielectric is defect-free. This work analyzes the effectiveness of this technique for revealing cracks in ceramic capacitors. It is shown that absorption currents prevail over the intrinsic leakage currents during standard IR measurements at room temperature. Absorption currents, and consequently IR, have a weak temperature dependence, increase linearly with voltage (before saturation), and are not sensitive to the presence of mechanical defects. In contrary, intrinsic leakage currents increase super-linearly with voltage and exponentially with temperature (activation energy is in the range from 0.6 eV to 1.1 eV). Leakage currents associated with the presence of cracks have a weaker dependence on temperature and voltage compared to the intrinsic leakage currents. For this reason, intrinsic leakage currents prevail at high temperatures and voltages, thus masking the presence of defects.

Aeronautical technology 2000: A projection of advanced vehicle concepts

NASA Technical Reports Server (NTRS)

1985-01-01

The Aeronautics and Space Engineering Board (ASEB) of the National Research Council conducted a Workshop on Aeronautical Technology: a Projection to the Year 2000 (Aerotech 2000 Workshop). The panels were asked to project advances in aeronautical technologies that could be available by the year 2000. As the workshop was drawing to a close, it became evident that a more comprehensive investigation of advanced air vehicle concepts than was possible in the limited time available at the workshop would be valuable. Thus, a special panel on vehicle applications was organized. In the course of two meetings, the panel identified and described representative types of aircraft judged possible with the workshop's technology projections. These representative aircraft types include: military aircraft; transport aircraft; rotorcraft; extremely high altitude aircraft; and transatmospheric aircraft. Improvements in performance, efficiency, and operational characteristics possible through the application of the workshop's year 2000 technology projections were discussed. The subgroups also identified the technologies considered essential and enhancing or supporting to achieve the projected aircraft improvements.

Study of Improvement of Hydrogen Maser Frequency Standard

NASA Technical Reports Server (NTRS)

Crampton, S. B.

1977-01-01

The research work dealt primarily with reducing the atom leakage rate using as storage surfaces the FEP Teflon surfaces conventionally used in contemporary hydrogen maser frequency standards. Some work was also done on a possible alternative to the conventional surfaces, but the results here and elsewhere suggest that the alternative surface is not promising enough to warrant much further work.

A study of leakage rates through mine seals in underground coal mines

PubMed Central

Schatzel, Steven J.; Krog, Robert B.; Mazzella, Andrew; Hollerich, Cynthia; Rubinstein, Elaine

2015-01-01

The National Institute for Occupational Safety and Health conducted a study on leakage rates through underground coal mine seals. Leakage rates of coal bed gas into active workings have not been well established. New seal construction standards have exacerbated the knowledge gap in our understanding of how well these seals isolate active workings near a seal line. At a western US underground coal mine, we determined seal leakage rates ranged from about 0 to 0.036 m3/s for seven 340 kPa seals. The seal leakage rate varied in essentially a linear manner with variations in head pressure at the mine seals. PMID:26322119

Cement Leakage in Percutaneous Vertebral Augmentation for Osteoporotic Vertebral Compression Fractures: Analysis of Risk Factors.

PubMed

Xie, Weixing; Jin, Daxiang; Ma, Hui; Ding, Jinyong; Xu, Jixi; Zhang, Shuncong; Liang, De

2016-05-01

The risk factors for cement leakage were retrospectively reviewed in 192 patients who underwent percutaneous vertebral augmentation (PVA). To discuss the factors related to the cement leakage in PVA procedure for the treatment of osteoporotic vertebral compression fractures. PVA is widely applied for the treatment of osteoporotic vertebral fractures. Cement leakage is a major complication of this procedure. The risk factors for cement leakage were controversial. A retrospective review of 192 patients who underwent PVA was conducted. The following data were recorded: age, sex, bone density, number of fractured vertebrae before surgery, number of treated vertebrae, severity of the treated vertebrae, operative approach, volume of injected bone cement, preoperative vertebral compression ratio, preoperative local kyphosis angle, intraosseous clefts, preoperative vertebral cortical bone defect, and ratio and type of cement leakage. To study the correlation between each factor and cement leakage ratio, bivariate regression analysis was employed to perform univariate analysis, whereas multivariate linear regression analysis was employed to perform multivariate analysis. The study included 192 patients (282 treated vertebrae), and cement leakage occurred in 100 vertebrae (35.46%). The vertebrae with preoperative cortical bone defects generally exhibited higher cement leakage ratio, and the leakage is typically type C. Vertebrae with intact cortical bones before the procedure tend to experience type S leakage. Univariate analysis showed that patient age, bone density, number of fractured vertebrae before surgery, and vertebral cortical bone were associated with cement leakage ratio (P<0.05). Multivariate analysis showed that the main factors influencing bone cement leakage are bone density and vertebral cortical bone defect, with standardized partial regression coefficients of -0.085 and 0.144, respectively. High bone density and vertebral cortical bone defect are

Detection of marginal leakage of Class V restorations in vitro by micro-computed tomography.

PubMed

Zhao, X Y; Li, S B; Gu, L J; Li, Y

2014-01-01

This in vitro study evaluated the efficacy of micro-computed tomography (CT) in marginal leakage detection of Class V restorations. Standardized Class V preparations with cervical margins in dentin and occlusal margins in enamel were made in 20 extracted human molars and restored with dental bonding agents and resin composite. All teeth were then immersed in 50% ammoniacal silver nitrate solution for 12 hours, followed by a developing solution for eight hours. Each restoration was scanned by micro-CT, the depth of marginal silver leakage in the central scanning section was measured, and the three-dimensional images of the silver leakage around each restoration were reconstructed. Afterward, all restorations were cut through the center and examined for leakage depth using a microscope. The silver leakage depth of each restoration obtained by the micro-CT and the microscope were compared for equivalency. The silver leakage depth in cervical walls observed by micro-CT and microscope showed no significant difference; however, in certain cases the judgment of leakage depth in the occlusal wall in micro-CT image was affected by adjacent enamel structure, providing less leakage depth than was observed with the microscope (p<0.01). Micro-CT displayed the three-dimensional image of the leakage around the Class V restorations with clear borders only in the dentin region. It can be concluded that micro-CT can detect nondestructively the leakage around a resin composite restoration in two and three dimensions, with accuracy comparable to that of the conventional microscope method in the dentin region but with inferior accuracy in the enamel region.

Pulse sequences for suppressing leakage in single-qubit gate operations

NASA Astrophysics Data System (ADS)

Ghosh, Joydip; Coppersmith, S. N.; Friesen, Mark

2017-06-01

Many realizations of solid-state qubits involve couplings to leakage states lying outside the computational subspace, posing a threat to high-fidelity quantum gate operations. Mitigating leakage errors is especially challenging when the coupling strength is unknown, e.g., when it is caused by noise. Here we show that simple pulse sequences can be used to strongly suppress leakage errors for a qubit embedded in a three-level system. As an example, we apply our scheme to the recently proposed charge quadrupole (CQ) qubit for quantum dots. These results provide a solution to a key challenge for fault-tolerant quantum computing with solid-state elements.

Spatial and Temporal Monitoring Resolutions for CO2 Leakage Detection at Carbon Storage Sites

NASA Astrophysics Data System (ADS)

Yang, Y. M.; Dilmore, R. M.; Daley, T. M.; Carroll, S.; Mansoor, K.; Gasperikova, E.; Harbert, W.; Wang, Z.; Bromhal, G. S.; Small, M.

2016-12-01

Different leakage monitoring techniques offer different strengths in detection sensitivity, coverage, feedback time, cost, and technology availability, such that they may complement each other when applied together. This research focuses on quantifying the spatial coverage and temporal resolution of detection response for several geophysical remote monitoring and direct groundwater monitoring techniques for an optimal monitoring plan for CO2 leakage detection. Various monitoring techniques with different monitoring depths are selected: 3D time-lapse seismic survey, wellbore pressure, groundwater chemistry and soil gas. The spatial resolution in terms of leakage detectability is quantified through the effective detection distance between two adjacent monitors, given the magnitude of leakage and specified detection probability. The effective detection distances are obtained either from leakage simulations with various monitoring densities or from information garnered from field test data. These spatial leakage detection resolutions are affected by physically feasible monitoring design and detection limits. Similarly, the temporal resolution, in terms of leakage detectability, is quantified through the effective time to positive detection of a given size of leak and a specified detection probability, again obtained either from representative leakage simulations with various monitoring densities or from field test data. The effective time to positive detection is also affected by operational feedback time (associated with sampling, sample analysis and data interpretation), with values obtained mainly through expert interviews and literature review. In additional to the spatial and temporal resolutions of these monitoring techniques, the impact of CO2 plume migration speed and leakage detection sensitivity of each monitoring technique are also discussed with consideration of how much monitoring is necessary for effective leakage detection and how these monitoring

Astronautics and aeronautics, 1976. A chronology

NASA Technical Reports Server (NTRS)

Ritchie, E. H.

1984-01-01

A chronology of events concerning astronautics and aeronautics for the year 1976 is presented. Some of the many and varied topics include the aerospace industry, planetary exploration, space transportation system, defense department programs, politics, and aerospace medicine. The entries are organized by the month and presented in a news release format.

A Nomogram to Predict Anastomotic Leakage in Open Rectal Surgery-Hope or Hype?

PubMed

Klose, Johannes; Tarantino, Ignazio; von Fournier, Armin; Stowitzki, Moritz J; Kulu, Yakup; Bruckner, Thomas; Volz, Claudia; Schmidt, Thomas; Schneider, Martin; Büchler, Markus W; Ulrich, Alexis

2018-05-18

Anastomotic leakage is the most dreaded complication after rectal resection and total mesorectal excision, leading to increased morbidity and mortality. Formation of a diverting ileostomy is generally performed to protect anastomotic healing. Identification of variables predicting anastomotic leakage might help to select patients who are under increased risk for the development of anastomotic leakage prior to surgery. The objective of this study was to assess the applicability of a nomogram as prognostic model for the occurrence of anastomotic leakage after rectal resection in a cohort of rectal cancer patients. Nine hundred seventy-two consecutive patients who underwent surgery for rectal cancer were retrospectively analyzed. Univariate and multivariable Cox regression analyses were used to determine independent risk factors associated with anastomotic leakage. Receiver operating characteristics (ROC) curve analysis was performed to calculate the sensitivity, specificity, and overall model correctness of a recently published nomogram and an adopted risk score based on the variables identified in this study as a predictive model. Male sex (p = 0.042), obesity (p = 0.017), smoking (p = 0.012), postoperative bleeding (p = 0.024), and total protein level ≤ 5.6 g/dl (p = 0.007) were identified as independent risk factors for anastomotic leakage. The investigated nomogram and the adopted risk score failed to reach relevant areas under the ROC curve greater than 0.700 for the prediction of anastomotic leakage. The proposed nomogram and the adopted risk score failed to reliably predict the occurrence of anastomotic leakage after rectal resection. Risk scores as prognostic models for the prediction of anastomotic leakage, independently of the study population, still need to be identified.

Rectal tube drainage reduces major anastomotic leakage after minimally invasive rectal cancer surgery.

PubMed

Yang, C-S; Choi, G-S; Park, J S; Park, S Y; Kim, H J; Choi, J-I; Han, K S

2016-12-01

Anastomotic leakage is the most serious complication following low anterior resection for rectal cancer and is a major cause of postoperative morbidity and mortality. The object of the present study was to investigate whether rectal tube drainage can reduce anastomotic leakage after minimally invasive rectal cancer surgery. Three hundred and seventy-four patients who underwent laparoscopic or robotic LAR for tumours located ≤ 15 cm above the anal verge between 1 April 2012 and 31 October 2014 were assessed retrospectively. Of these, 107 with intermediate risk of anastomotic leakage received transanal rectal tube drainage. The rectal tube group was matched by propensity score analysis with patients not having rectal tube drainage, giving 204 patients in the study. Covariates for propensity score analysis included age, sex, body mass index, tumour height from the anal verge and preoperative chemoradiation. Patient demographics, tumour location, preoperative chemoradiation and operative results were similar between the two groups. The overall leakage rate was 10.8% (22/204), with no significant difference between the rectal tube group (9.8%) and the nonrectal tube group (11.8%, P = 0.652). Of the patients with anastomotic leakage, major leakage requiring reoperation developed in 11.8% of those without and 3.9% of those with a rectal tube. On multivariate analysis, age over 65 years and nonuse of a rectal tube were found to be independent risk factors for major anastomotic leakage. Rectal tube placement may be a safe and effective method of reducing the rate of major anastomotic leakage, alleviating the clinical course of leakage following minimally invasive rectal cancer surgery. Colorectal Disease © 2016 The Association of Coloproctology of Great Britain and Ireland.

A retrospective analysis of endoscopic treatment outcomes in patients with postoperative bile leakage.

PubMed

Sayar, Suleyman; Olmez, Sehmus; Avcioglu, Ufuk; Tenlik, Ilyas; Saritas, Bunyamin; Ozdil, Kamil; Altiparmak, Emin; Ozaslan, Ersan

2016-01-01

Bile leakage, while rare, can be a complication seen after cholecystectomy. It may also occur after hepatic or biliary surgical procedures. Etiology may be underlying pathology or surgical complication. Endoscopic retrograde cholangiopancreatography (ERCP) can play major role in diagnosis and treatment of bile leakage. Present study was a retrospective analysis of outcomes of ERCP procedure in patients with bile leakage. Patients who underwent ERCP for bile leakage after surgery between 2008 and 2012 were included in the study. Etiology, clinical and radiological characteristics, and endoscopic treatment outcomes were recorded and analyzed. Total of 31 patients (10 male, 21 female) were included in the study. ERCP was performed for bile leakage after cholecystectomy in 20 patients, after hydatid cyst operation in 10 patients, and after hepatic resection in 1 patient. Clinical signs and symptoms of bile leakage included abdominal pain, bile drainage from percutaneous drain, peritonitis, jaundice, and bilioma. Twelve (60%) patients were treated with endoscopic sphincterotomy (ES) and nasobiliary drainage (NBD) catheter, 7 patients (35%) were treated with ES and biliary stent (BS), and 1 patient (5%) was treated with ES alone. Treatment efficiency was 100% in bile leakage cases after cholecystectomy. Ten (32%) cases of hydatid cyst surgery had subsequent cystobiliary fistula. Of these patients, 7 were treated with ES and NBD, 2 were treated with ES and BS, and 1 patient (8%) with ES alone. Treatment was successful in 90% of these cases. ERCP is an effective method to diagnose and treat bile leakage. Endoscopic treatment of postoperative bile leakage should be individualized based on etiological and other factors, such as accompanying fistula.

A retrospective analysis of endoscopic treatment outcomes in patients with postoperative bile leakage

PubMed Central

Sayar, Suleyman; Olmez, Sehmus; Avcioglu, Ufuk; Tenlik, Ilyas; Saritas, Bunyamin; Ozdil, Kamil; Altiparmak, Emin; Ozaslan, Ersan

2016-01-01

OBJECTIVE: Bile leakage, while rare, can be a complication seen after cholecystectomy. It may also occur after hepatic or biliary surgical procedures. Etiology may be underlying pathology or surgical complication. Endoscopic retrograde cholangiopancreatography (ERCP) can play major role in diagnosis and treatment of bile leakage. Present study was a retrospective analysis of outcomes of ERCP procedure in patients with bile leakage. METHODS: Patients who underwent ERCP for bile leakage after surgery between 2008 and 2012 were included in the study. Etiology, clinical and radiological characteristics, and endoscopic treatment outcomes were recorded and analyzed. RESULTS: Total of 31 patients (10 male, 21 female) were included in the study. ERCP was performed for bile leakage after cholecystectomy in 20 patients, after hydatid cyst operation in 10 patients, and after hepatic resection in 1 patient. Clinical signs and symptoms of bile leakage included abdominal pain, bile drainage from percutaneous drain, peritonitis, jaundice, and bilioma. Twelve (60%) patients were treated with endoscopic sphincterotomy (ES) and nasobiliary drainage (NBD) catheter, 7 patients (35%) were treated with ES and biliary stent (BS), and 1 patient (5%) was treated with ES alone. Treatment efficiency was 100% in bile leakage cases after cholecystectomy. Ten (32%) cases of hydatid cyst surgery had subsequent cystobiliary fistula. Of these patients, 7 were treated with ES and NBD, 2 were treated with ES and BS, and 1 patient (8%) with ES alone. Treatment was successful in 90% of these cases. CONCLUSION: ERCP is an effective method to diagnose and treat bile leakage. Endoscopic treatment of postoperative bile leakage should be individualized based on etiological and other factors, such as accompanying fistula. PMID:28058396

Aeronautics and Space Report of the President: Fiscal Year 1996 Activities

NASA Technical Reports Server (NTRS)

1996-01-01

Topics considered include: (1) Space launch activities: space shuttle missions; expendable launch vehicles. (2) Space science: astronomy and space physics; solar system exploration. (3) Space flight and technology: life and microgravity sciences; space shuttle technology; reuseable launch vehicles; international space station; energy; safety and mission assurance; commercial development and regulation of space; surveillance. (4) Space communications: communications satellites; space network; ground networks; mission control and data systems. (5) Aeronautical activities: technology developments; air traffic control and navigation; weather-related aeronautical activities; flight safety and security; aviation medicine and human factors. (6) Studies of the planet earth: terrestrial studies and applications: atmospheric studies: oceanographic studies; international aeronautical and space activities; and appendices.

Microvascular dysfunction with increased vascular leakage response in mice systemically exposed to arsenic.

PubMed

Chen, Shih-Chieh; Huang, Shin-Yin; Lu, Chi-Yu; Hsu, Ya-Hung; Wang, Dean-Chuan

2014-09-01

The mechanisms underlying cardiovascular disease induced by arsenic exposure are not completely understood. The objectives of this study were to investigate whether arsenic-fed mice have an increased vascular leakage response to vasoactive agents and whether enhanced type-2 protein phosphatase (PP2A) activity is involved in mustard oil-induced leakage. ICR mice were fed water or sodium arsenite (20 mg/kg) for 4 or 8 weeks. The leakage response to vasoactive agents was quantified using the Evans blue (EB) technique or vascular labeling with carbon particles. Increased EB leakage and high density of carbon-labeled microvessels were detected in arsenic-fed mice treated with mustard oil. Histamine induced significantly higher vascular leakage in arsenic-fed mice than in water-fed mice. Pretreatment with the PP2A inhibitor okadaic acid or the neurokinin 1 receptor (NK1R) blocker RP67580 significantly reduced mustard oil-induced vascular leakage in arsenic-fed mice. The protein levels of PP2Ac and NK1R were similar in both groups. PP2A activity was significantly higher in the arsenic-fed mice compared with the control group. These findings indicate that microvessels generally respond to vasoactive agents, and that the increased PP2A activity is involved in mustard oil-induced vascular leakage in arsenic-fed mice. Arsenic may initiate endothelial dysfunction, resulting in vascular leakage in response to vasoactive agents.

Water Leakage Diagnosis in Metro Tunnels by Intergration of Laser Point Cloud and Infrared Thermal Imaging

NASA Astrophysics Data System (ADS)

Yu, P.; Wu, H.; Liu, C.; Xu, Z.

2018-04-01

Diagnosis of water leakage in metro tunnels is of great significance to the metro tunnel construction and the safety of metro operation. A method that integrates laser scanning and infrared thermal imaging is proposed for the diagnosis of water leakage. The diagnosis of water leakage in this paper is mainly divided into two parts: extraction of water leakage geometry information and extraction of water leakage attribute information. Firstly, the suspected water leakage is obtained by threshold segmentation based on the point cloud of tunnel. And the real water leakage is obtained by the auxiliary interpretation of infrared thermal images. Then, the characteristic of isotherm outline is expressed by solving Centroid Distance Function to determine the type of water leakage. Similarly, the location of leakage silt and the direction of crack are calculated by finding coordinates of feature points on Centroid Distance Function. Finally, a metro tunnel part in Shanghai was selected as the case area to make experiment and the result shown that the proposed method in this paper can be used to diagnosis water leakage disease completely and accurately.

A cumulative index to the 1972 issues of aeronautical engineering: A special bibliography

NASA Technical Reports Server (NTRS)

1973-01-01

A cumulative index to the abstracts contained in NASA SP-7037 (15) through NASA SP-7037 (26) of Aeronautical Engineering: A Special Bibliography. NASA SP-7037 and its supplements has been complied through the cooperative efforts of the American Institute of Aeronautics and Astronautics (AIAA) and the National Aeronautics and Space Administration (NASA). This cumulative index includes subject, personal author, corporate source, contract, and report number indexes.

Short-term effects of CO2 leakage on the soil bacterial community in a simulated gas leakage scenario.

PubMed

Ma, Jing; Zhang, Wangyuan; Zhang, Shaoliang; Zhu, Qianlin; Feng, Qiyan; Chen, Fu

2017-01-01

The technology of carbon dioxide (CO 2 ) capture and storage (CCS) has provided a new option for mitigating global anthropogenic emissions with unique advantages. However, the potential risk of gas leakage from CO 2 sequestration and utilization processes has attracted considerable attention. Moreover, leakage might threaten soil ecosystems and thus cannot be ignored. In this study, a simulation experiment of leakage from CO 2 geological storage was designed to investigate the short-term effects of different CO 2 leakage concentration (from 400 g m -2 day -1 to 2,000 g m -2 day -1 ) on soil bacterial communities. A shunt device and adjustable flow meter were used to control the amount of CO 2 injected into the soil. Comparisons were made between soil physicochemical properties, soil enzyme activities, and microbial community diversity before and after injecting different CO 2 concentrations. Increasing CO 2 concentration decreased the soil pH, and the largest variation ranged from 8.15 to 7.29 ( p < 0.05). Nitrate nitrogen content varied from 1.01 to 4.03 mg/Kg, while Olsen-phosphorus and total phosphorus demonstrated less regular downtrends. The fluorescein diacetate (FDA) hydrolytic enzyme activity was inhibited by the increasing CO 2 flux, with the average content varying from 22.69 to 11.25 mg/(Kg h) ( p < 0.05). However, the increasing activity amplitude of the polyphenol oxidase enzyme approached 230%, while the urease activity presented a similar rising trend. Alpha diversity results showed that the Shannon index decreased from 7.66 ± 0.13 to 5.23 ± 0.35 as the soil CO 2 concentration increased. The dominant phylum in the soil samples was Proteobacteria , whose proportion rose rapidly from 28.85% to 67.93%. In addition, the proportion of Acidobacteria decreased from 19.64% to 9.29% ( p < 0.01). Moreover, the abundances of genera Methylophilus , Methylobacillus , and Methylovorus increased, while GP4 , GP6 and GP7 decreased. Canonical correlation analysis

Leakage Account for Radial Face Contact Seal in Aircraft Engine Support

NASA Astrophysics Data System (ADS)

Vinogradov, A. S.; Sergeeva, T. V.

2018-01-01

The article is dedicated to the development of a methodology for the radial face contact seal design taking into consideration the supporting elements deformations in different aircraft engine operating modes. Radial face contact seals are popular in the aircraft engines bearing support. However, there are no published leakage calculation methodologies of these seals. Radial face contact seal leakage is determined by the gap clearance in the carbon seal ring split. In turn, the size gap clearance depends on the deformation of the seal assembly parts and from the engine operation. The article shows the leakage detection sequence in the intershaft radial face contact seal of the compressor support for take-off and cruising modes. Evaluated calculated leakage values (2.4 g/s at takeoff and 0.75 g/s at cruising) go with experience in designing seals.

An ocean scatter propagation model for aeronautical satellite communication applications

NASA Technical Reports Server (NTRS)

Moreland, K. W.

1990-01-01

In this paper an ocean scattering propagation model, developed for aircraft-to-satellite (aeronautical) applications, is described. The purpose of the propagation model is to characterize the behavior of sea reflected multipath as a function of physical propagation path parameters. An accurate validation against the theoretical far field solution for a perfectly conducting sinusoidal surface is provided. Simulation results for typical L band aeronautical applications with low complexity antennas are presented.

Aeronautics Technology Possibilities for 2000: Report of a Workshop (January 1984).

ERIC Educational Resources Information Center

National Academy of Sciences - National Research Council, Washington, DC. Commission on Engineering and Technical Systems.

The National Research Council's Aeronautics and Space Engineering Board conducted a workshop in January 1984 to project what the state of knowledge of aeronautical technology could be in the year 2000 if necessary supporting resources were made available. Eight panels were organized to assess possibilities in the areas of: (1) aerodynamics; (2)…

Can the intraoperative leak test prevent postoperative leakage of esophagojejunal anastomosis after total gastrectomy?

PubMed

Kanaji, Shingo; Ohyama, Masato; Yasuda, Takashi; Sendo, Hiroyoshi; Suzuki, Satoshi; Kawasaki, Kentaro; Tanaka, Kenichi; Fujino, Yasuhiro; Tominaga, Masahiro; Kakeji, Yoshihiro

2016-07-01

Anastomotic failures that cannot be detected during surgery often lead to postoperative leakage. There have been no detailed reports on the intraoperative leak test for esophagojejunal anastomosis. Our purpose was to investigate the utility of routine intraoperative leak testing to prevent postoperative anastomotic leakage after performing esophagojejunostomy. We prospectively performed routine air leak tests and reviewed the records of 185 consecutive patients with gastric cancer who underwent open total gastrectomy followed by esophagojejunostomy. A positive leak test was found for six patients (3.2 %). These patients with positive leak tests were subsequently treated with additional suturing, and they developed no postoperative anastomotic leakage. However, anastomotic leakage occurred in nine patients (4.9 %) with negative leak tests. A multivariate analysis demonstrated that a patient age >75 years and the surgeon's experience <30 cases were risk factors for anastomotic leakage. Intraoperative leak testing can detect some physical dehiscence, and additional suturing may prevent anastomotic leakage. However, it cannot prevent all anastomotic leakage caused by other factors, such as the surgeons' experience and patients' age.

Astronautics and Aeronautics, 1979-1984: A chronology

NASA Technical Reports Server (NTRS)

Janson, Bette R.; Ritchie, Eleanor H.

1989-01-01

This volume of the Astronautics and Aeronautics series covers 1979 through 1984. The series provides a chronological presentation of all significant events and developments in space exploration and the administration of the space program during the period covered.

47 CFR 76.616 - Operation near certain aeronautical and marine emergency radio frequencies.

Code of Federal Regulations, 2012 CFR

2012-10-01

... (CONTINUED) BROADCAST RADIO SERVICES MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Technical Standards § 76... of carriers or other signal components capable of delivering peak power levels equal to or greater than 10−5 watts at any point in a cable television system is prohibited within 100 kHz of the frequency...

47 CFR 76.616 - Operation near certain aeronautical and marine emergency radio frequencies.

Code of Federal Regulations, 2014 CFR

2014-10-01

... (CONTINUED) BROADCAST RADIO SERVICES MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Technical Standards § 76... of carriers or other signal components capable of delivering peak power levels equal to or greater than 10−5 watts at any point in a cable television system is prohibited within 100 kHz of the frequency...

A cumulative index to the 1973 issues of Aeronautical engineering: A special bibliography

NASA Technical Reports Server (NTRS)

1974-01-01

This publication is a cumulative index to the abstracts contained in NASA SP-7037 (28) through NASA SP-7037 (39) of Aeronautical Engineering: A Special Bibliography. NASA SP-7037 and its supplements have been compiled through the cooperative efforts of the American Institute of Aeronautics and Astronautics (AIAA) and the National Aeronautics and Space Administration (NASA). This cumulative index includes subject, personal author, corporate source, contract, and report number indexes.

Leakage of fluid in different types of tracheal tubes.

PubMed

Winklmaier, U; Wüst, K; Schiller, S; Wallner, F

2006-10-01

The aim of this study was to evaluate leakage of liquids, i.e., water and saliva, past low-pressure cuffs of tracheostomy tubes. Three different types of tracheostomy tubes, TRACOE vario (TRACOE Medical GmbH, Germany), Rüsch Ultra-Tracheoflex (Rüsch GmbH, Germany), and Portex Blue Line Ultra (Smiths Medical, UK) were tested in isolated pig tracheas. Sixty samples (10 tubes each of 7- and 8-mm inner diameter of each type) were used. Four different experiments were devised: type 1 (water and artificial ventilation), type 2 (water and no artificial ventilation), type 3 (saliva and artificial ventilation), and type 4 (saliva and no artificial ventilation). Six milliliters of water or artificial saliva were infused over the cuff and the volume of fluid that leaked past the cuff was measured after 5, 10, and 15 min. Intracuff pressure was also measured three times. The saliva experiments resulted in less leakage than the water experiments. Leakage after treatment with water or artificial saliva is higher without artificial ventilation than with ventilation. The amount of leakage among the tubes with respect to manufacturer showed statistically significant results. However, there were no differences among tracheostomy tubes with respect to internal diameter.

Two-well terahertz quantum cascade lasers with suppressed carrier leakage

NASA Astrophysics Data System (ADS)

Albo, Asaf; Flores, Yuri V.; Hu, Qing; Reno, John L.

2017-09-01

The mechanisms that limit the temperature performance of diagonal GaAs/Al0.15GaAs0.85-based terahertz quantum cascade lasers (THz-QCLs) have been identified as thermally activated leakage of charge carriers through excited states into the continuum. THz-QCLs with energetically higher-laying excited states supported by sufficiently high barriers aim to eliminate these leakage mechanisms and lead to improved temperature performance. Although suppression of thermally activated carrier leakage was realized in a three-well THz-QCL based on a resonant-phonon scheme, no improvement in the temperature performance was reported thus far. Here, we report a major improvement in the temperature performance of a two-quantum-well direct-phonon THz-QCL structure. We show that the improved laser performance is due to the suppression of the thermally activated carrier leakage into the continuum with the increase in the injection barrier height. Moreover, we demonstrate that high-barrier two-well structures can support a clean three-level laser system at elevated temperatures, which opens the opportunity to achieve temperature performance beyond the state-of-the-art.

Crack detection and leakage monitoring on reinforced concrete pipe

NASA Astrophysics Data System (ADS)

Feng, Qian; Kong, Qingzhao; Huo, Linsheng; Song, Gangbing

2015-11-01

Reinforced concrete underground pipelines are some of the most widely used types of structures in water transportation systems. Cracks and leakage are the leading causes of pipeline structural failures which directly results in economic losses and environmental hazards. In this paper, the authors propose a piezoceramic based active sensing approach to detect the cracks and the further leakage of concrete pipelines. Due to the piezoelectric properties, piezoceramic material can be utilized as both the actuator and the sensor in the active sensing approach. The piezoceramic patch, which is sandwiched between protective materials called ‘smart aggregates,’ can be safely embedded into concrete structures. Circumferential and axial cracks were investigated. A wavelet packet-based energy analysis was developed to distinguish the type of crack and determine the further leakage based on different stress wave energy attenuation propagated through the cracks.

Leakage-resistant blood vessels in mice transgenically overexpressing angiopoietin-1.

PubMed

Thurston, G; Suri, C; Smith, K; McClain, J; Sato, T N; Yancopoulos, G D; McDonald, D M

1999-12-24

Angiopoietin-1 (Ang1) and vascular endothelial growth factor (VEGF) are endothelial cell-specific growth factors. Direct comparison of transgenic mice overexpressing these factors in the skin revealed that the VEGF-induced blood vessels were leaky, whereas those induced by Ang1 were nonleaky. Moreover, vessels in Ang1-overexpressing mice were resistant to leaks caused by inflammatory agents. Coexpression of Ang1 and VEGF had an additive effect on angiogenesis but resulted in leakage-resistant vessels typical of Ang1. Ang1 therefore may be useful for reducing microvascular leakage in diseases in which the leakage results from chronic inflammation or elevated VEGF and, in combination with VEGF, for promoting growth of nonleaky vessels.

ERROR REDUCTION IN DUCT LEAKAGE TESTING THROUGH DATA CROSS-CHECKS

DOE Office of Scientific and Technical Information (OSTI.GOV)

ANDREWS, J.W.

1998-12-31

One way to reduce uncertainty in scientific measurement is to devise a protocol in which more quantities are measured than are absolutely required, so that the result is over constrained. This report develops a method for so combining data from two different tests for air leakage in residential duct systems. An algorithm, which depends on the uncertainty estimates for the measured quantities, optimizes the use of the excess data. In many cases it can significantly reduce the error bar on at least one of the two measured duct leakage rates (supply or return), and it provides a rational method ofmore » reconciling any conflicting results from the two leakage tests.« less

Air Force Academy Aeronautics Digest.

DTIC Science & Technology

1984-03-01

Farren, Glauert, R. H. Fowler , George Thomson, E . D. Adrian and Melvill Jones were certainly "Chudleighites." When I arrived at Farnborough I was put to... E . McCann, Lt. Colonel, USAF Director of Research, Studies, and Analysis UNCLASSIFIED SECURITY CLASSIFICATION OF TIlS PAGE REPORT DOCUMENTATION PAGE...NOS P ROGRAM PROJECT TASK WORK UNIT E LE MENT NO. NO. NO. NO * 11 TITLE fInclude Secuity Clawiaiciceton) Air Force Academy Aeronautics Digest

Astronautics and aeronautics, 1978: A chronology

NASA Technical Reports Server (NTRS)

Janson, Bette R.

1986-01-01

This is the 18th in a series of annual chronologies of significant events in the fields of astronautics and aeronautics. Events covered are international as well as national and political as well as scientific and technical. This series is a reference work for historians, NASA personnel, government agencies, congressional staffs, and the media.

14 CFR 61.109 - Aeronautical experience.

Code of Federal Regulations, 2012 CFR

2012-01-01

... Aeronautical experience. (a) For an airplane single-engine rating. Except as provided in paragraph (k) of this section, a person who applies for a private pilot certificate with an airplane category and single-engine...-country flight training in a single-engine airplane; (2) Except as provided in § 61.110 of this part, 3...

14 CFR 61.109 - Aeronautical experience.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Aeronautical experience. (a) For an airplane single-engine rating. Except as provided in paragraph (k) of this section, a person who applies for a private pilot certificate with an airplane category and single-engine...-country flight training in a single-engine airplane; (2) Except as provided in § 61.110 of this part, 3...

14 CFR 61.109 - Aeronautical experience.

Code of Federal Regulations, 2013 CFR

2013-01-01

... Aeronautical experience. (a) For an airplane single-engine rating. Except as provided in paragraph (k) of this section, a person who applies for a private pilot certificate with an airplane category and single-engine...-country flight training in a single-engine airplane; (2) Except as provided in § 61.110 of this part, 3...

14 CFR 61.109 - Aeronautical experience.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Aeronautical experience. (a) For an airplane single-engine rating. Except as provided in paragraph (k) of this section, a person who applies for a private pilot certificate with an airplane category and single-engine...-country flight training in a single-engine airplane; (2) Except as provided in § 61.110 of this part, 3...

14 CFR 61.109 - Aeronautical experience.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Aeronautical experience. (a) For an airplane single-engine rating. Except as provided in paragraph (k) of this section, a person who applies for a private pilot certificate with an airplane category and single-engine...-country flight training in a single-engine airplane; (2) Except as provided in § 61.110 of this part, 3...

Prevalence of extravertebral cement leakage after vertebroplasty: procedural documentation versus CT detection.

PubMed

Martin, Douglas J; Rad, Arash Ehteshami; Kallmes, David F

2012-06-01

Reported incidence of extravertebral cement leakage after vertebroplasty varies widely across studies. To retrospectively compare the relative detection rates of extravertebral leakage noted under intra-procedural fluoroscopic surveillance, postprocedure plain radiographs, and postprocedure computed tomography (CT) in a cohort of patients undergoing vertebroplasty. With IRB approval, we retrospectively identified 181 patients with 277 levels treated with percutaneous vertebroplasty among a total of 1255 patients undergoing vertebroplasty between 1999 and 2010 who had subsequently undergone a CT examination that included the treated level(s). Categories of leakage were paravertebral, end plate, epidural, and prevertebral venous leakage. CT-detected leak rates were then compared to those noted on the vertebroplasty procedure reports and the archived fluoroscopic images for this same cohort using Pearson's χ(2) test. One hundred and forty-nine (82%, 95% CI 76-87%) of 181 patients demonstrated evidence of some type of leakage on CT at one or more treated levels. Sixty-two (34%, 95% CI 28-42%) and seventy-seven (50%, 95% CI 43-57%) of 149 CT-detected leaks were reported in the procedural dictation or detected on plain radiography (P = 0.01 and 0.006, respectively). The most common type of leakage noted on CT was end plate (n = 81, 45%, 95% CI 38-52%), followed by paravertebral (n = 64, 35%, 95% CI 29-43%), epidural (n = 36, 20%, 95% CI 15-26%), and prevertebral venous (n = 32, 18%, 95% CI 13-24%). Cement leakage after vertebroplasty is common and is often not reported by operators in procedural dictations. CT detects substantially more leaks than plain radiography.

Leakage Risk Assessment for a Potential CO2 Storage Project in Saskatchewan, Canada

DOE Office of Scientific and Technical Information (OSTI.GOV)

Houseworth, J.E.; Oldenburg, C.M.; Mazzoldi, A.

2011-05-01

A CO{sub 2} sequestration project is being considered to (1) capture CO{sub 2} emissions from the Consumers Cooperative Refineries Limited at Regina, Saskatchewan and (2) geologically sequester the captured CO{sub 2} locally in a deep saline aquifer. This project is a collaboration of several industrial and governmental organizations, including the Petroleum Technology Research Centre (PTRC), Sustainable Development Technology Canada (SDTC), SaskEnvironment Go Green Fund, SaskPower, CCRL, Schlumberger Carbon Services, and Enbridge. The project objective is to sequester 600 tonnes CO{sub 2}/day. Injection is planned to start in 2012 or 2013 for a period of 25 years for a total storagemore » of approximately 5.5 million tonnes CO{sub 2}. This report presents an assessment of the leakage risk of the proposed project using a methodology known as the Certification Framework (CF). The CF is used for evaluating CO{sub 2} leakage risk associated with geologic carbon sequestration (GCS), as well as brine leakage risk owing to displacement and pressurization of brine by the injected CO{sub 2}. We follow the CF methodology by defining the entities (so-called Compartments) that could be impacted by CO{sub 2} leakage, the CO{sub 2} storage region, the potential for leakage along well and fault pathways, and the consequences of such leakage. An understanding of the likelihood and consequences of leakage forms the basis for understanding CO{sub 2} leakage risk, and forms the basis for recommendations of additional data collection and analysis to increase confidence in the risk assessment.« less

Gas-path leakage seal for a turbine

DOEpatents

Bagepalli, B.S.; Aksit, M.F.; Farrell, T.R.

1999-08-10

A gas-path leakage seal for generally sealing a gas-path leakage-gap between spaced-apart first and second members of a turbine (such as combustor casing segments of a gas turbine). The seal includes a flexible and generally imperforate metal sheet assemblage having opposing first and second surfaces and two opposing raised edges extending a generally identical distance above and below the surfaces. A first cloth layer assemblage has a thickness generally equal to the previously-defined identical distance and is superimposed on the first surface between the raised edges. A second cloth layer assemblage is generally identical to the first cloth layer assemblage and is superimposed on the second surface between the raised edges. 5 figs.

Gas-path leakage seal for a turbine

DOEpatents

Bagepalli, Bharat Sampathkumaran; Aksit, Mahmut Faruk; Farrell, Thomas Raymond

1999-01-01

A gas-path leakage seal for generally sealing a gas-path leakage-gap between spaced-apart first and second members of a turbine (such as combustor casing segments of a gas turbine). The seal includes a flexible and generally imperforate metal sheet assemblage having opposing first and second surfaces and two opposing raised edges extending a generally identical distance above and below the surfaces. A first cloth layer assemblage has a thickness generally equal to the previously-defined identical distance and is superimposed on the first surface between the raised edges. A second cloth layer assemblage is generally identical to the first cloth layer assemblage and is superimposed on the second surface between the raised edges.

A coupled approach for the three-dimensional simulation of pipe leakage in variably saturated soil

NASA Astrophysics Data System (ADS)

Peche, Aaron; Graf, Thomas; Fuchs, Lothar; Neuweiler, Insa

2017-12-01

In urban water pipe networks, pipe leakage may lead to subsurface contamination or to reduced waste water treatment efficiency. The quantification of pipe leakage is challenging due to inaccessibility and unknown hydraulic properties of the soil. A novel physically-based model for three-dimensional numerical simulation of pipe leakage in variably saturated soil is presented. We describe the newly implemented coupling between the pipe flow simulator HYSTEM-EXTRAN and the groundwater flow simulator OpenGeoSys and its validation. We further describe a novel upscaling of leakage using transfer functions derived from numerical simulations. This upscaling enables the simulation of numerous pipe defects with the benefit of reduced computation times. Finally, we investigate the response of leakage to different time-dependent pipe flow events and conclude that larger pipe flow volume and duration lead to larger leakage while the peak position in time has a small effect on leakage.

Method of detecting leakage from geologic formations used to sequester CO.sub.2

DOEpatents

White, Curt [Pittsburgh, PA; Wells, Arthur [Bridgeville, PA; Diehl, J Rodney [Pittsburgh, PA; Strazisar, Brian [Venetia, PA

2010-04-27

The invention provides methods for the measurement of carbon dioxide leakage from sequestration reservoirs. Tracer moieties are injected along with carbon dioxide into geological formations. Leakage is monitored by gas chromatographic analyses of absorbents. The invention also provides a process for the early leak detection of possible carbon dioxide leakage from sequestration reservoirs by measuring methane (CH.sub.4), ethane (C.sub.2H.sub.6), propane (C.sub.3H.sub.8), and/or radon (Rn) leakage rates from the reservoirs. The invention further provides a method for branding sequestered carbon dioxide using perfluorcarbon tracers (PFTs) to show ownership.

What kind of students should be developed through aeronautical engineering education?

NASA Technical Reports Server (NTRS)

Holloway, R. B.

1975-01-01

The educational requirements for future aeronautical engineering students are postulated. The change in aeronautical engineering from increasing aircraft performance without regard to cost is compared with the cost effective aspects of future research. The capabilities of future engineers are discussed with respect to the following areas: (1) problem solving, (2) planning and organizing, (3) communication, and (4) professionalism.

Aeronautical Engineering: A cumulative index to the 1984 issues of the continuing bibliography

NASA Technical Reports Server (NTRS)

1985-01-01

This bibliography is a cumulative index to the abstracts contained in NASA SP-7037(171) through NASA SP-7037(182) of Aeronautical Engineering: A Continuing Bibliography. NASA SP-7037 and its supplements have been compiled through the cooperative efforts of the American Institute of Aeronautics and Astronautics (AIAA) and the National Aeronautics and Space Administration (NASA). This cumulative index includes subject, personal author, corporate source, foreign technology, contract, report number, and accession number indexes.

Percutaneous Management of Postoperative Duodenal Stump Leakage with Foley Catheter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oh, Jung Suk, E-mail: oj-cumc@daum.net; Lee, Hae Giu, E-mail: hgleehfh@catholic.ac.kr; Chun, Ho Jong

2013-10-15

Purpose: This study was designed to evaluate retrospectively the safety and efficacy of the percutaneous management of duodenal stump leakage with a Foley catheter after subtotal gastrectomy. Methods: Ten consecutive patients (M:F = 9:1, median age: 64 years) were included in this retrospective study. The duodenal stump leakages were diagnosed in all the patients within a median of 10 days (range, 6-20). At first, the patients underwent percutaneous drainage on the day of or the day after confirmation of the presence of duodenal stump leakage, and then the Foley catheters were replaced at a median of 9 days (range, 6-38)more » after the percutaneous drainage. Results: Foley catheters were placed successfully in the duodenal lumen of all the patients under a fluoroscopic guide. No complication was observed during and after the procedures in all the patients. All of the patients started a regular diet 1 day after the Foley catheter placement. The patients were discharged at a median of 7 days (range, 5-14) after the Foley catheter placement. The catheters were removed in an outpatient clinic 10-58 days (median, 28) after the Foley catheter placement. Conclusions: Fluoroscopy-guided percutaneous Foley catheter placement may be a safe and effective treatment option for postoperative duodenal stump leakage and may allow for shorter hospital stays, earlier oral intake, and more effective control of leakage sites.« less

Influence of optic disc leakage on objective optic nerve head assessment in patients with uveitis.

PubMed

Heinz, Carsten; Kogelboom, Katy; Heiligenhaus, Arnd

2016-02-01

Secondary glaucoma is a common complication in patients with uveitis. Heidelberg Retina Tomography (HRT) and retinal nerve fiber layer (RNFL) thickness on optical coherence tomography (OCT) are widely used for examining optic nerve head changes. We evaluated these parameters in patients with uveitis and secondary glaucoma and with inflammatory papillary leakage on fluorescein angiography. Prospective single-center analysis of patients with uveitis, evaluating the impact of optic disc leakage on objective optic disc imaging parameters. Overall, 96 eyes of 59 patients were included. Papillary leakage was found in 42 eyes (43.8 %), and secondary glaucoma was found in 41 eyes (42.7 %). Glaucoma and papillary leakage were present in 12 (29 %) eyes with leakage and in 29 (54 %) eyes without leakage (p = 0.023). Neuroretinal rim area (p = 0.004), rim volume on HRT (p = 0.004), and RNFL thickness on OCT (p = 0.0008) were significantly increased in eyes with papillary leakage, while RNFL on HRT was unchanged (p = 0.255). When only eyes with normal IOP were examined, all objective parameters on OCT and HRT were significantly increased, whereas in eyes with secondary glaucoma, there was only a trend in the same direction, which did not reach significance. A comparison of eyes with secondary glaucoma and optic disc leakage to normal eyes with no glaucoma or leakage revealed no difference in any of the parameters. The objective parameters of optic nerve head imaging tools are significantly influenced by papillary leakage. In patients with secondary glaucoma and papillary leakage, these techniques are unable to detect and monitor glaucomatous damage.

Developing a global aeronautical satellite system

NASA Technical Reports Server (NTRS)

Dement, Donald K.

1988-01-01

Arinc, an airline industry-owned and operated company in the United States, has taken steps toward establishing a global aeronautical satellite communications system. Plans call for initiation of a thin-route data operation in 1989, upgrading to establish voice communications via shared spot-beam transponders carried on other satellites, and deploying a worldwide network using dedicated satellites by 1994.

14 CFR 61.129 - Aeronautical experience.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Aeronautical experience. (a) For an airplane single-engine rating. Except as provided in paragraph (i) of this...-engine class rating must log at least 250 hours of flight time as a pilot that consists of at least: (1... required on instrument training must be in a single engine airplane; (ii) 10 hours of training in an...

14 CFR 61.129 - Aeronautical experience.

Code of Federal Regulations, 2013 CFR

2013-01-01

... Aeronautical experience. (a) For an airplane single-engine rating. Except as provided in paragraph (i) of this...-engine class rating must log at least 250 hours of flight time as a pilot that consists of at least: (1... required on instrument training must be in a single engine airplane; (ii) 10 hours of training in an...

14 CFR 61.129 - Aeronautical experience.

Code of Federal Regulations, 2012 CFR

2012-01-01

... Aeronautical experience. (a) For an airplane single-engine rating. Except as provided in paragraph (i) of this...-engine class rating must log at least 250 hours of flight time as a pilot that consists of at least: (1... required on instrument training must be in a single engine airplane; (ii) 10 hours of training in an...

14 CFR 61.129 - Aeronautical experience.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Aeronautical experience. (a) For an airplane single-engine rating. Except as provided in paragraph (i) of this...-engine class rating must log at least 250 hours of flight time as a pilot that consists of at least: (1... required on instrument training must be in a single engine airplane; (ii) 10 hours of training in an...

14 CFR 61.129 - Aeronautical experience.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Aeronautical experience. (a) For an airplane single-engine rating. Except as provided in paragraph (i) of this...-engine class rating must log at least 250 hours of flight time as a pilot that consists of at least: (1... required on instrument training must be in a single engine airplane; (ii) 10 hours of training in an...

Astronautics and aeronautics, 1985: A chronology

NASA Technical Reports Server (NTRS)

Janson, Bette R.

1988-01-01

This book is part of a series of annual chronologies of significant events in the fields of astronautics and aeronautics. Events covered are international as well as national, in political as well as scientific and technical areas. This series is an important reference work used by historians, NASA personnel, government agencies, and congressional staffs, as well as the media.

Pumping‐induced leakage in a bounded aquifer: An example of a scale‐invariant phenomenon

USGS Publications Warehouse

Butler, James J.; Tsou, Ming‐shu

2003-01-01

A new approach is presented for calculation of the volume of pumping‐induced leakage entering an aquifer as a function of time. This approach simplifies the total leakage calculation by extending analytical‐based methods developed for infinite systems to bounded aquifers of any size. The simplification is possible because of the relationship between drawdown and leakage in aquifers laterally bounded by impermeable formations. This relationship produces a scale‐invariant total leakage; i.e., the volume of leakage as a function of time does not change with the size of the aquifer or with the location of the pumping well. Two examples and image well theory are used to demonstrate and prove, respectively, the generality of this interesting phenomenon.

76 FR 66350 - Eighth Meeting: RTCA Special Committee 222 Inmarsat Aeronautical Mobile Satellite (Route) Services

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-26

... Committee 222 Inmarsat Aeronautical Mobile Satellite (Route) Services AGENCY: Federal Aviation..., Inmarsat Aeronautical Mobile Satellite (Route) Services meeting. SUMMARY: The FAA is issuing this notice to advise the public of a meeting of RTCA Special Committee 222, Inmarsat Aeronautical Mobile Satellite...

77 FR 30046 - Ninth Meeting: RTCA Special Committee 222, Inmarsat Aeronautical Mobile Satellite (Route) Services

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-21

... 222, Inmarsat Aeronautical Mobile Satellite (Route) Services AGENCY: Federal Aviation Administration..., Inmarsat Aeronautical Mobile Satellite (Route) Services. SUMMARY: The FAA is issuing this notice to advise the public of the Ninth meeting of RTCA Special Committee 222, Inmarsat Aeronautical Mobile Satellite...

Engineering a robust DNA split proximity circuit with minimized circuit leakage

PubMed Central

Ang, Yan Shan; Tong, Rachel; Yung, Lin-Yue Lanry

2016-01-01

DNA circuit is a versatile and highly-programmable toolbox which can potentially be used for the autonomous sensing of dynamic events, such as biomolecular interactions. However, the experimental implementation of in silico circuit designs has been hindered by the problem of circuit leakage. Here, we systematically analyzed the sources and characteristics of various types of leakage in a split proximity circuit which was engineered to spatially probe for target sites held within close proximity. Direct evidence that 3′-truncated oligonucleotides were the major impurity contributing to circuit leakage was presented. More importantly, a unique strategy of translocating a single nucleotide between domains, termed ‘inter-domain bridging’, was introduced to eliminate toehold-independent leakages while enhancing the strand displacement kinetics across a three-way junction. We also analyzed the dynamics of intermediate complexes involved in the circuit computation in order to define the working range of domain lengths for the reporter toehold and association region respectively. The final circuit design was successfully implemented on a model streptavidin-biotin system and demonstrated to be robust against both circuit leakage and biological interferences. We anticipate that this simple signal transduction strategy can be used to probe for diverse biomolecular interactions when used in conjunction with specific target recognition moieties. PMID:27207880

Oil leakage detection for electric power equipment based on ultraviolet fluorescence effect

NASA Astrophysics Data System (ADS)

Zhang, Jing; Wang, Jian-hui; Xu, Bin; Huang, Zhi-dong; Huang, Lan-tao

2018-03-01

This paper presents a method to detect the oil leakage of high voltage power equipment based on ultraviolet fluorescence effect. The method exploits the principle that the insulating oil has the fluorescent effect under the irradiation of specific ultraviolet light. The emission spectrum of insulating oil under excitation light with different wavelengths is measured and analyzed first. On this basis, a portable oil leakage detective device for high voltage power equipment is designed and developed with a selected 365 nm ultraviolet as the excitation light and the low light level camera as the fluorescence image collector. Then, the feasibility of the proposed method and device in different conditions is experimentally verified in the laboratory environment. Finally, the developed oil leakage detective device is applied to 500 kV Xiamen substation and Quanzhou substation. And the results show that the device can detect the oil leakage of high voltage electrical equipment quickly and conveniently even under the condition of a slight oil leakage especially in the low light environment.

Mitigating leakage errors due to cavity modes in a superconducting quantum computer

NASA Astrophysics Data System (ADS)

McConkey, T. G.; Béjanin, J. H.; Earnest, C. T.; McRae, C. R. H.; Pagel, Z.; Rinehart, J. R.; Mariantoni, M.

2018-07-01

A practical quantum computer requires quantum bit (qubit) operations with low error probabilities in extensible architectures. We study a packaging method that makes it possible to address hundreds of superconducting qubits by means of coaxial Pogo pins. A qubit chip is housed in a superconducting box, where both box and chip dimensions lead to unwanted modes that can interfere with qubit operations. We analyze these interference effects in the context of qubit coherent leakage and qubit decoherence induced by damped modes. We propose two methods, half-wave fencing and antinode pinning, to mitigate the resulting errors by detuning the resonance frequency of the modes from the qubit frequency. We perform electromagnetic field simulations indicating that the resonance frequency of the modes increases with the number of installed pins and can be engineered to be significantly higher than the highest qubit frequency. We estimate that the error probabilities and decoherence rates due to suitably shifted modes in realistic scenarios can be up to two orders of magnitude lower than the state-of-the-art superconducting qubit error and decoherence rates. Our methods can be extended to different types of packages that do not rely on Pogo pins. Conductive bump bonds, for example, can serve the same purpose in qubit architectures based on flip chip technology. Metalized vias, instead, can be used to mitigate modes due to the increasing size of the dielectric substrate on which qubit arrays are patterned.

Aeronautical engineering. A continuing bibliography with indexes

NASA Technical Reports Server (NTRS)

1982-01-01

This bibliography lists 326 reports, articles, and other documents introduced into the NASA scientific and technical information system in January 1982. Topics on aeronautical engineering and aerodynamics such as flight control systems, avionics, computer programs, computational fluid dynamics and composite structures are covered.

Leakage characterization of top select transistor for program disturbance optimization in 3D NAND flash

NASA Astrophysics Data System (ADS)

Zhang, Yu; Jin, Lei; Jiang, Dandan; Zou, Xingqi; Zhao, Zhiguo; Gao, Jing; Zeng, Ming; Zhou, Wenbin; Tang, Zhaoyun; Huo, Zongliang

2018-03-01

In order to optimize program disturbance characteristics effectively, a characterization approach that measures top select transistor (TSG) leakage from bit-line is proposed to quantify TSG leakage under program inhibit condition in 3D NAND flash memory. Based on this approach, the effect of Vth modulation of two-cell TSG on leakage is evaluated. By checking the dependence of leakage and corresponding program disturbance on upper and lower TSG Vth, this approach is validated. The optimal Vth pattern with high upper TSG Vth and low lower TSG Vth has been suggested for low leakage current and high boosted channel potential. It is found that upper TSG plays dominant role in preventing drain induced barrier lowering (DIBL) leakage from boosted channel to bit-line, while lower TSG assists to further suppress TSG leakage by providing smooth potential drop from dummy WL to edge of TSG, consequently suppressing trap assisted band-to-band tunneling current (BTBT) between dummy WL and TSG.

Multipath modeling for aeronautical communications.

NASA Technical Reports Server (NTRS)

Painter, J. H.; Gupta, S. C.; Wilson, L. R.

1973-01-01

One of the fundamental technical problems in aeronautical digital communications is that of multipath propagation between aircraft and ground terminal. This paper examines in detail a model of the received multipath signal that is useful for application of modern detection and estimation theories. The model treats arbitrary modulation and covers the selective and nonselective cases. The necessarily nonstationary statistics of the received signal are determined from the link geometry and the surface roughness parameters via a Kirchhoff solution.

An Investigation of Tendon Corrosion-Inhibitor Leakage into Concrete

DOE Office of Scientific and Technical Information (OSTI.GOV)

Costello, J.F.; Naus, D.J.; Oland, C.B.

1999-07-05

During inspections performed at US nuclear power plants several years ago, some of the prestressed concrete containment had experienced leakage of the tendon sheathing filler. A study was conducted to indicate the extent of the leakage into the concrete and its potential effects on concrete properties. Concrete core samples were obtained from the Trojan Nuclear Plant. Examination and testing of the core samples indicated that the appearance of tendon sheathing filler on the surface was due to leakage of the filler from the conduits and its subsequent migration to the concrete surface through cracks that were present. Migration of themore » tendon sheathing filler was confined to the cracks with no perceptible movement into the concrete. Results of compressive strength tests indicated that the concrete quality was consistent in the containment and that the strength had increased relative to the strength at 28 days age.« less

First Semiannual Report of the National Aeronautics and Space Administration

NASA Technical Reports Server (NTRS)

Glennan, T. Keith

1959-01-01

The First Semiannual Report of the National Aeronautics and Space Administration (NASA) is submitted to Congress pursuant to section 206 (a) of the National Aeronautics and Space Act of 1958 (Public Law 85-568) to provide for research into problems of flight within and outside the Earth's atmosphere, which states: The Administration shall submit to the President for transmittal to Congress, semiannually and at such other times as it deems desirable, a report on its activities and accomplishments.

The Aeronautics Education, Research, and Industry Alliance (AERIAL) 2002 Report

NASA Technical Reports Server (NTRS)

Bowen, Brent D.; Box, Richard C.; Fink, Mary; Gogos, George; Lehrer, Henry R.; Narayanan, Ram M.; Nickerson, Jocelyn S.; Tarry, Scott E.; Vlasek, Karisa D.; O'Neil, Patrick D.

2002-01-01

The NASA Nebraska Space Grant Consortium (NSGC) & EPSCoR programs at the University of Nebraska at Omaha are involved in a variety of innovative research activities. Such research is supported through the Aeronautics Education, Research, and Industry Alliance (AERIAL) and collaborative seed funds. AERIAL is a comprehensive, multi-faceted, five year NASA EPSCoR initiative that contributes substantially to the strategic research and technology priorities of NASA while intensifying Nebraska s rapidly growing aeronautics research and development endeavors. AERIAL includes three major collaborative research teams (CRTs) whose nexus is a common focus in aeronautics research. Each CRT - Small Aircraft Transportation System (SATS), Airborne Remote Sensing for Agricultural Research and Commercialization Applications (ARS), and Numerical Simulation of the Combustion of Fuel Droplets: Finite Rate Kinetics and Flame Zone Grid Adaptation (CEFD) -has a distinct research agenda. This program provides the template for funding of new and innovative research that emphasizes aerospace technology.

Aeronautics. An Educator's Guide with Activities in Science, Mathematics, and Technology Education: What Pilot, Astronaut, or Aeronautical Engineer didn't Start out with a Toy Glider?

NASA Technical Reports Server (NTRS)

Biggs, Pat (Editor); Huetter, Ted (Editor)

1998-01-01

Welcome to the exciting world of aeronautics. The term aeronautics originated in France, and was derived from the Greek words for "air" and "to sail." It is the study of flight and the operation of aircraft. This educator guide explains basic aeronautical concepts, provides a background in the history of aviation, and sets them within the context of the flight environment (atmosphere, airports, and navigation). The activities in this guide are designed to be uncomplicated and fun. They have been developed by NASA Aerospace Education Services Program specialists, who have successfully used them in countless workshops and student programs around the United States. The activities encourage students to explore the nature of flight, and experience some real-life applications of mathematics, science, and technology. The subject of flight has a wonderful power to inspire learning.

Embolization for Thoracic Duct Collateral Leakage in High-Output Chylothorax After Thoracic Surgery

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kariya, Shuji, E-mail: kariyas@hirakata.kmu.ac.jp; Nakatani, Miyuki, E-mail: nakatanm@hirakata.kmu.ac.jp; Yoshida, Rie, E-mail: yagir@hirakata.kmu.ac.jp

PurposeThis study was designed to investigate thoracic duct collateral leakage and the supply route of lymphatic fluid by lymphangiography and transcatheter thoracic ductography and to evaluate the results of embolization for thoracic duct collateral leakage performed to cut off this supply route.MethodsData were retrospectively collected from five patients who underwent embolization for thoracic duct collateral leakage in persistent high-output chylothorax after thoracic surgery. Extravasation of lipiodol at the ruptured thoracic duct collaterals was confirmed in all patients on lymphangiography. Transcatheter thoracic ductography was used to identify extravasation of iodinated contrast agent and to identify communication between the thoracic duct andmore » leakage site. Thoracic duct embolization (TDE) was performed using the percutaneous transabdominal approach to cut off the supply route using N-butyl cyanoacrylate (NBCA) mixed with lipiodol (1:5–1:20).ResultsClinical success (drainage volume ≤10 mL/kg/day within 7 days after TDE) was achieved in all patients. The collateral routes developed as consequence of surgical thoracic duct ligation. In three patients, NBCA-Lipiodol reached the leakage site through direct communication between the thoracic duct and the ruptured lymphatic duct. In the other two patients, direct communication and extravasation was not detected on thoracic ductography, and NBCA-Lipiodol did not reach the leakage site. However, NBCA-Lipiodol did reach the cisterna chyli, lumbar trunks, and some collateral routes via the cisterna chyli or lumbar lymphatics. As a result, leakage was stopped.ConclusionsTDE was effective for the management of leakage of the collaterals in high-output chylothorax after thoracic surgery.« less