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Sample records for airflow gage experiment

  1. Flight Test Results from the Rake Airflow Gage Experiment on the F-15B Airplane

    NASA Technical Reports Server (NTRS)

    Frederick, Michael A.; Ratnayake, Nalin A.

    2011-01-01

    The Rake Airflow Gage Experiment involves a flow-field survey rake that was flown on the Propulsion Flight Test Fixture at the NASA Dryden Flight Research Center using the Dryden F-15B research test bed airplane. The objective of this flight test was to ascertain the flow-field angularity, local Mach number profile, total pressure distortion, and dynamic pressure at the aerodynamic interface plane of the Channeled Centerbody Inlet Experiment. This new mixed-compression, supersonic inlet is planned for flight test in the near term. Knowledge of the flow-field characteristics at this location underneath the airplane is essential to flight test planning and computational modeling of the new inlet, an< it is also applicable for future propulsion systems research that may use the Propulsion Flight Test Fixture. This report describes the flight test preparation and execution, and the local flow-field properties calculated from pressure measurements of the rake. Data from the two Rake Airflow Gage Experiment research flights demonstrate that the F-15B airplane, flying at a free-stream Mach number of 1.65 and a pressure altitude of 40,000 ft, would achieve the desired local Mach number for the future inlet flight test. Interface plane distortion levels of 2 percent and a local angle of attack of -2 deg were observed at this condition. Alternative flight conditions for future testing and an exploration of certain anomalous data also are provided.

  2. Flight Test Results from the Rake Airflow Gage Experiment on the F-15B Airplane

    NASA Technical Reports Server (NTRS)

    Frederick, Michael A.; Ratnayake, Nalin A.

    2010-01-01

    The Rake Airflow Gage Experiment involves a flow-field survey rake that was flown on the Propulsion Flight Test Fixture at the NASA Dryden Flight Research Center using the Dryden F-15B research test bed airplane. The objective of this flight test was to ascertain the flow-field angularity, local Mach number profile, total pressure distortion, and dynamic pressure at the aerodynamic interface plane of the Channeled Centerbody Inlet Experiment. This new mixed-compression, supersonic inlet is planned for flight test in the near term. Knowledge of the flow-field characteristics at this location underneath the airplane is essential to flight test planning and computational modeling of the new inlet, and it is also applicable for future propulsion systems research that may use the Propulsion Flight Test Fixture. This report describes the flight test preparation and execution, and the local flowfield properties calculated from pressure measurements of the rake. Data from the two Rake Airflow Gage Experiment research flights demonstrate that the F-15B airplane, flying at a free-stream Mach number of 1.65 and a pressure altitude of 40,000 ft, would achieve the desired local Mach number for the future inlet flight test. Interface plane distortion levels of 2 percent and a local angle of attack of 2 were observed at this condition. Alternative flight conditions for future testing and an exploration of certain anomalous data also are provided.

  3. Flight Test Results from the Rake Airflow Gage Experiment on the F-15B

    NASA Technical Reports Server (NTRS)

    Frederick, Michael; Ratnayake, Nalin

    2011-01-01

    The results are described of the Rake Airflow Gage Experiment (RAGE), which was designed and fabricated to support the flight test of a new supersonic inlet design using Dryden's Propulsion Flight Test Fixture (PFTF) and F-15B testbed airplane (see figure). The PFTF is a unique pylon that was developed for flight-testing propulsion-related experiments such as inlets, nozzles, and combustors over a range of subsonic and supersonic flight conditions. The objective of the RAGE program was to quantify the local flowfield at the aerodynamic interface plane of the Channeled Centerbody Inlet Experiment (CCIE). The CCIE is a fixed representation of a conceptual mixed-compression supersonic inlet with a translating biconic centerbody. The primary goal of RAGE was to identify the relationship between free-stream and local Mach number in the low supersonic regime, with emphasis on the identification of the particular free-stream Mach number that produced a local Mach number of 1.5. Measurements of the local flow angularity, total pressure distortion, and dynamic pressure over the interface plane were also desired. The experimental data for the RAGE program were obtained during two separate research flights. During both flights, local flowfield data were obtained during straight and level acceleration segments out to steady-state test points. The data obtained from the two flights showed small variations in Mach number, flow angularity, and dynamic pressure across the interface plane at all flight conditions. The data show that a free-stream Mach number of 1.65 will produce the desired local Mach number of 1.5 for CCIE. The local total pressure distortion over the interface plane at this condition was approximately 1.5%. At this condition, there was an average of nearly 2 of downwash over the interface plane. This small amount of downwash is not expected to adversely affect the performance of the CCIE inlet.

  4. Design and field experience with the WES 10 percent bar airblast and soil stress gage

    NASA Astrophysics Data System (ADS)

    Joachim, C. E.; Welch, C. R.

    1985-06-01

    A family of shock transducers based on the classical load-cell geometry, i.e., the elastic compression of a column, is currently under development at the waterways Experiment Station. The transducers include an airblast gage, a soil stress gage, and a soil-structure interface stress gage. These gages operate at considerable higher pressure ranges than previous elastic shock transducers. The airblast gage has provided long term (over 10 msec) measurements in blast environments of over 600 MPa (6 kbar). The theoretical operating pressure range of the gages is approximately 1000 MPa (10 kbar) limited by the elastic limit of the gage body steel. The actual pressure range to date has been limited by acceleration induced failures of the strain gages and internal wiring. The transducer development, is described and some dynamic measurements produced from these gages are given.

  5. Experiments to study strain gage load calibrations on a wing structure at elevated temperatures

    NASA Technical Reports Server (NTRS)

    Monaghan, R. C.; Fields, R. A.

    1973-01-01

    Laboratory experiments were performed to study changes in strain-gage bridge load calibrations on a wing structure heated to temperatures of 200 F, 400 F, and 600 F. Data were also obtained to define the experimental repeatability of strain-gage bridge outputs. Experiments were conducted to establish the validity of the superposition of bridge outputs due to thermal and mechanical loads during a heating simulation of Mach 3 flight. The strain-gage bridge outputs due to load cycle at each of the above temperature levels were very repeatable. A number of bridge calibrations were found to change significantly as a function of temperature. The sum of strain-gage bridge outputs due to individually applied thermal and mechanical loads compared well with that due to combined or superimposed loads. The validity of superposition was, therefore, established.

  6. Image Correlation Applied to Single Crystal Plasticity Experiments and Comparison to Strain Gage Data

    SciTech Connect

    LeBlanc, M M; Florando, J N; Lassila, D H; Schmidt, T; Tyson II, J

    2005-06-29

    Full-field optical techniques are becoming increasingly popular for measuring the deformation of materials, especially in materials that exhibit non-uniform behavior. While there are many full-field techniques available (e.g. moire interferometry, electronic speckle pattern interferometry (ESPI), holography, and image correlation [1]), for our study of the deformation of single crystals, the image correlation technique was chosen for its insensitivity to vibrations and ability to measure large strains. While the theory and development of the algorithms for image correlation have been presented elsewhere [2,3] a comparative study to a conventional strain measurement device, such as a strain gage rosette, is desired to test the robustness and accuracy of the technique. The 6 Degrees of Freedom (6DOF) experiment, which was specifically designed to validate dislocation dynamics (DD) simulations [4], is ideally suited to compare the two methods. This experiment is different from previous experiments on single crystals in that it allows the crystal to deform essentially unconstrained, in both the elastic and plastic regimes, by allowing the bottom of the sample to move as the sample is being compressed. This unconstrained motion prevents the internal crystal planes from rotating during the deformation as typically seen in the pioneering work of Schmid [5] and Taylor [6]. In the early development of the 6DOF apparatus, stacked strain gage rosettes were used to provide the strain data [7]. While very accurate at small strains, strain gages provide an averaged measurement over a small area and cannot be used to measure the inhomogeneous plastic strains that typically occur during the 6DOF experiment. An image correlation technique can measure the full-field in-plane and out-of-plane deformation that occurs in single crystals, and a comparison to the strain gage data at small strains can test the accuracy of the method.

  7. Strain Gage

    NASA Technical Reports Server (NTRS)

    1995-01-01

    HITEC Corporation developed a strain gage application for DanteII, a mobile robot developed for NASA. The gage measured bending forces on the robot's legs and warned human controllers when acceptable forces were exceeded. HITEC further developed the technology for strain gage services in creating transducers out of "Indy" racing car suspension pushrods, NASCAR suspension components and components used in motion control.

  8. Development of buried wire gages for measurement of wall shear stress in Blastane experiments

    NASA Technical Reports Server (NTRS)

    Murthy, S. V.; Steinle, F. W.

    1986-01-01

    Buried Wire Gages operated from a Constant Temperature Anemometer System are among the special types of instrumentation to be used in the Boundary Layer Apparatus for Subsonic and Transonic flow Affected by Noise Environment (BLASTANE). These Gages are of a new type and need to be adapted for specific applications. Methods were developed to fabricate Gage inserts and mount those in the BLASTANE Instrumentation Plugs. A large number of Gages were prepared and operated from a Constant Temperature Anemometer System to derive some of the calibration constants for application to fluid-flow wall shear-stress measurements. The final stage of the calibration was defined, but could not be accomplished because of non-availability of a suitable flow simulating apparatus. This report provides a description of the Buried Wire Gage technique, an explanation of the method evolved for making proper Gages and the calibration constants, namely Temperature Coefficient of Resistance and Conduction Loss Factor.

  9. The Atmospheric Lifetime Experiment and the Global Atmospheric Gas Experiment (ALE/GAGE)

    NASA Technical Reports Server (NTRS)

    Rasmussen, R. A.; Khalil, M. Aslam K.

    1995-01-01

    The ALE/GAGE project was designed to determine the global atmospheric lifetimes of the chlorofluorocarbons CCl3F and CCl2F2 (F-11 and F-12), which had been identified as the main gases that cause stratospheric ozone depletion. The experimental procedures also provided the concentrations of CH3CCl3, CCl4 and N2O. The extended role of the project was to evaluate the mass balances of these gases as well. Methylchloroform (CH3CCl3) serves as a tracer of average atmospheric OH concentrations and hence the oxidizing capacity of the atmosphere. Nitrous oxide (N2O) is a potent greenhouse gas and can also deplete the ozone layer. Measurements of these gases were taken with optimized instruments in the field at a frequency of about 1 sample/hr. Toward the end of the present project methane measurements were added to the program. The final report deals with the research of the Oregon Graduate Institute (OGI) as part of the ALE/GAGE program between 4/1/1988 and 1/31/1991. The report defines the scope of the OGI project, the approach, and the results.

  10. Gage cookbook: Tools and techniques to measure stresses and motions on explosive experiments

    SciTech Connect

    Smith, C.W.

    1996-01-01

    Tools and techniques developed to measure stresses and motions on underground nuclear and high explosive tests in the tuff geologies at the Nevada Test Site are described in this document. The thrust of the measurements was to understand containment phenomenology. The authors concentrate on the fluid-coupled ytterbium gage; it was fielded to measure dynamic stress in the 0.2 to 20 kilobar range and the subsequent, low amplitude residual stress. Also described are accelerometer packages; their traces were integrated to obtain particle motion. Various cable survival techniques were investigated with field measurements for they wished to extend the measurements to late-time. Field measurements were also made to address the gage inclusion problem. Work to date suggests that the problem is a minimum when the stress level is above the yield strength of the host rock and grout. Below the yield level stress amplitudes in the grouted hole can range from 60 to 200% of the stress in the host rock.

  11. Field experience and performance summary using the EPRI EMAT-based gaging system for boiler tubing

    SciTech Connect

    Schlader, D.; Stevens, D.; Nakoneczny, G.; Tilley, R.

    1996-07-01

    The Electric Power Research Institute (EPRI) and the Babcock & Wilcox (B&W) Company have developed a boiler tube thickness gage using EMATs (Electromagnetic Acoustic Transducers) which can be used in either a spot measuring or a scanning mode to identify localized wall thinning due to corrosion or erosion. A field-hardened, prototype version has been constructed and tested in a wide range of utility boilers. The prototype has been refined into a commercial grade system that is being utilized by B&W to supply services to utilities. This paper describes the EMAT gaging system and presents results of field applications in utility boilers. The EMAT system in its current configuration is capable of measuring tube wall thickness as thin as 0.070 inches with an accuracy comparable to conventional ultrasonic measurements, {+-}0.005 inches. Thickness readings can be obtained on tube wall surfaces which have been sandblasted or ground free of scale, and on tube wall surfaces which have uniform layers of scale. The presence of scale, in some instances, can greatly enhance the ultrasonic signal strength, allowing thickness measurements on tubes without any surface preparation as long as the scale layer is uniform.

  12. A comparison of airborne and ground-based radar observations with rain gages during the CaPE experiment

    NASA Technical Reports Server (NTRS)

    Satake, Makoto; Short, David A.; Iguchi, Toshio

    1992-01-01

    The vicinity of KSC, where the primary ground truth site of the Tropical Rainfall Measuring Mission (TRMM) program is located, was the focal point of the Convection and Precipitation/Electrification (CaPE) experiment in Jul. and Aug. 1991. In addition to several specialized radars, local coverage was provided by the C-band (5 cm) radar at Patrick AFB. Point measurements of rain rate were provided by tipping bucket rain gage networks. Besides these ground-based activities, airborne radar measurements with X- and Ka-band nadir-looking radars on board an aircraft were also recorded. A unique combination data set of airborne radar observations with ground-based observations was obtained in the summer convective rain regime of central Florida. We present a comparison of these data intending a preliminary validation. A convective rain event was observed simultaneously by all three instrument types on the evening of 27 Jul. 1991. The high resolution aircraft radar was flown over convective cells with tops exceeding 10 km and observed reflectivities of 40 to 50 dBZ at 4 to 5 km altitude, while the low resolution surface radar observed 35 to 55 dBZ echoes and a rain gage indicated maximum surface rain rates exceeding 100 mm/hr. The height profile of reflectivity measured with the airborne radar show an attenuation of 6.5 dB/km (two way) for X-band, corresponding to a rainfall rate of 95 mm/hr.

  13. A comparison of airborne and ground-based radar observations with rain gages during the CaPE experiment

    NASA Technical Reports Server (NTRS)

    Satake, Makoto; Short, David A.; Iguchi, Toshio

    1992-01-01

    The vicinity of KSC, where the primary ground truth site of the Tropical Rainfall Measuring Mission (TRMM) program is located, was the focal point of the Convection and Precipitation/Electrification (CaPE) experiment in July and Aug. 1991. In addition to several specialized radars, local coverage was provided by the C-band (5 cm) radar at Patrick AFB. Point measurements of rain rate were provided by tipping bucket rain gage networks. Besides these ground-based activities, airborne radar measurements with X- and Ka-band nadir-looking radars on board an aircraft were also recorded. A unique combination data set of airborne radar observations with ground-based observations was obtained in the summer convective rain regime of central Florida. We present a comparison of these data intending a preliminary validation. A convective rain event was observed simultaneously by all three instrument types on the evening of 27 July 1991. The high resolution aircraft radar was flown over convective cells with tops exceeding 10 km and observed reflectivities of 40 to 50 dBZ at 4 to 5 km altitude, while the low resolution surface radar observed 35 to 55 dBZ echoes and a rain gage indicated maximum surface rain rates exceeding 100 mm/hr. The height profile of reflectivity measured with the airborne radar show an attenuation of 6.5 dB/km (two way) for X-band, corresponding to a rainfall rate of 95 mm/hr.

  14. Low-g propellant gaging

    NASA Astrophysics Data System (ADS)

    Orton, George

    1987-09-01

    A program to develop and demonstrate technology for low gravity propellant gaging on future geostationary satellites is described. Evaluations were performed to select four gaging concepts for ground tests and low gravity tests in the NASA KC-135 aircraft. The selected concepts were: (1) an ultrasonic point sensor system, (2) a nucleonic gaging system, (3) an ultrasonic torsional wave guide, and (4) an ultrasonic flowmeter. As a result of successful ground and KC-135 tests, two concepts (the ultrasonic point sensor and the nucleonic systems) were selected for orbital test in a shuttle Get-Away-Special experiment.

  15. NOVA 201 ultrasonic thickness gage (NOVA Gage)

    NASA Technical Reports Server (NTRS)

    Garecht, Diane

    1990-01-01

    The measurement integrity of the NOVA 201 digital ultrasonic thickness gage (NOVA gage) was demonstrated by comparing the NOVA gage measurements to the thickness gage measurements, and determining the bias and uncertainty of the NOVA gage when measuring redesigned solid rocket motor (RSRM) hardware per engineering test plans (ETP). The NOVA gage was tested by three different operators on steel and aluminum RSRM hardware for wall thickness. The results show that the measurement bias is not consistent. The uncertainty of the bias is caused by the heterogeneous material properties of the RSRM components that influence the time of flight of ultrasonic waves. The measurement uncertainty inherent to the design and operation of the NOVA gage is less in comparison to the uncertainty of the bias. The total measurement uncertainty cannot be substantially reduced by taking more than one measurement. There is no correlation between bias and the surface finish range of this test unless 3-in-One oil is used as a couplant, in which case there appears to be a slight trend. There is no correlation between uncertainty and the surface finish range. The measurement uncertainty of the NOVA gage can be reduced using 3-in-One oil as a couplant.

  16. Strain gage balances and buffet gages

    NASA Technical Reports Server (NTRS)

    Ferris, A. T.

    1983-01-01

    One-piece strain gage force balances were developed for use in the National Transonic Facility (NTF). This was accomplished by studying the effects of the cryogenic environment on materials, strain gages, cements, solders, and moisture proofing agents, and selecting those that minimized strain gage output changes due to temperature. In addition, because of the higher loads that may be imposed by the NTF, these balances are designed to carry a larger load for a given diameter than conventional balances. Full cryogenic calibrations were accomplished, and wind tunnel results that were obtained from the Langley 0-3-Meter Transonic Cryogenic Tunnel were used to verify laboratory test results.

  17. Resistance fail strain gage technology as applied to composite materials

    NASA Technical Reports Server (NTRS)

    Tuttle, M. E.; Brinson, H. F.

    1985-01-01

    Existing strain gage technologies as applied to orthotropic composite materials are reviewed. The bonding procedures, transverse sensitivity effects, errors due to gage misalignment, and temperature compensation methods are addressed. Numerical examples are included where appropriate. It is shown that the orthotropic behavior of composites can result in experimental error which would not be expected based on practical experience with isotropic materials. In certain cases, the transverse sensitivity of strain gages and/or slight gage misalignment can result in strain measurement errors.

  18. High temperature strain gage apparent strain compensation

    NASA Technical Reports Server (NTRS)

    Holmes, Harlan K.; Moore, T. C., Sr.

    1992-01-01

    Once an installed strain gage is connected to a strain indicating device and the instrument is balanced, a subsequent change in temperature of the gage installation will generally produce a resistance change in the gage. This purely temperature-induced resistance will be registered by the indicating device as a strain and is referred to as 'apparent strain' to distinguish it from strain due to applied stress. One desirable technique for apparent strain compensation is to employ two identical gages with identical mounting procedures which are connected with a 'half bridge' configuration where gages see the same thermal environment but only one experiences a mechanical strain input. Their connection in adjacent arms of the bridge will then balance the thermally induced apparent strains and, in principle, only the mechanical strain remains. Two approaches that implement this technique are discussed.

  19. Analysis of Hopkinson bar pressure gage. Final report

    SciTech Connect

    Baylot, J.T.

    1993-01-01

    U.S. Army Engineer Waterways Experiment Station (WES) designed Hopkinson pressure bar gages were fielded on the Dilute Explosive Tile (DET) test along with New Mexico Engineering Research Institute (NMERI) designed bar gages and pressure gages manufactured by PCB Piezotronics, Inc. On the Mineral Find 3 (MF3) explosive test, WES bar gages were fielded along with pressure transducers manufactured by Kulite. The peak pressures recorded by the PCB ages were much higher than those recorded by the WES bar gages on the DET test. The peak stresses were higher for the Kulite gages than for the WES bar gages in the MF3 test. In each of these tests, the stresses recorded later in time for the bar gage were higher than those recorded for the other types of gages. The NMERI gages indicated that the pressure time-history had two significant peaks while the WES gages indicated only one significant peak. One-half of the surviving PCB gages agreed with the WES gages, while one-half agreed with the NMERI gages. Analytical and finite element (FE) calculations were performed to assess the response of the bar gages in these tests. The analytical solutions included only the bar and agreed extremely well with comparable FE calculations. These calculations indicated that the primary reason for the low peak stress readings in the bar gages was the lower frequency response capability of the recording system used to record the bar gage data. The calculations also indicated that the presence of water around the bar did not significantly affect the measured peak stress in the bar, and that the drag of the water past the bar did not cause significant forces to be developed in the bar.

  20. Airflow resistance in soybean

    NASA Astrophysics Data System (ADS)

    Kenghe, R. N.; Nimkar, P. M.; Shirkole, S. S.; Shinde, K. J.

    2012-04-01

    Resistance of material to airflow is an important factor to consider in the design of a dryer or an aeration system. The airflow resistance of soybean was determined with the modified airflow resistance apparatus. It was found that pressure drop increased with increase in airflow rate, bulk density, bed depth and decreased with moisture content. Modified Shedd equation, Hukill and Ives equation and modified Ergun equation were examined for pressure drop prediction. Airflow resistance was accurately described by modified Shedd equation followed by Hukill and Ives equation and modified Ergun equation. The developed statistical model comprised of airflow rate, moisture content and bulk density could fit pressure drop data reasonably well.

  1. Observations of the far ultraviolet airflow by the Ultraviolet Limb Imaging experiment on STS-39

    NASA Technical Reports Server (NTRS)

    Budzien, S. A.; Feldman, P. D.; Conway, R. R.

    1994-01-01

    The Ultraviolet Limb Imaging (UVLIM) experiment flew on STS-39 in the spring of 1991 to observe the Earth's thermospheric airglow and included a far ultraviolet (1080-1800 A) spectrometer. We present first results from this spectrometer, including a spectroscopic analysis at 6-A resolution of H, O, N, and N2 dayglow emissions and modeling of the observed limb-scan profiles of dayglow emissions. The observed N2 Lyman-Birge-Hopfield (LBH) emission reflects a vibrational population distribution in the a(1 Pi)(sub g) state that differs significantly from those predicted for direct electron excitation and excitation with cascade from the a('1 Sigma)(sub u)(-) and w(1 Delta)(sub u) states. The vibrational population distribution and LBH brightness suggest a total cascade rate 45% that of direct excitation, in contrast to laboratory measurements. For the first time, pronounced limb brightening is observed in both the N I lambda 1200 limb emission profiles, as expected for emissions excited by N2 dissociation which produces kinetically fast N fragments; however, optically thick components of these features are also observed. Preliminary modeling of the OI lambda 1356, HI lambda 1216, and OI lambda 1304 and OI lambda 1641 emissions agrees to within roughly 10% of the observed limb-scan profiles, but the models underestimate the N2 LBH profiles by a factor of 1.4-1.6, consistent with the inferred cascade effect. Other findings include: an OI lambda 1152/lambda 1356 intensity ratio that is inconsistent with the large cascade contribution to OI lambda 1356 from np 5P states required by laboratory and nightglow observations; nightglow observations of the tropical ultraviolet arcs exhibit a wide range of OI lambda 1356/lambda 1304 intensity ratios and illustrate the complicated observing geometry and radiative transfer effects that must be modeled; and we find a 3-sigma upper limit of 8.5 R to the total LBH vehicle glow emission.

  2. Propellant gaging for geostationary satellites

    NASA Astrophysics Data System (ADS)

    Orazietti, A. J.; Orton, G. F.; Schreib, R.

    1986-06-01

    Evaluations were performed to select four gaging concepts for ground tests and low-g tests in the NASA KC-135 aircraft. The selected concepts were an ultrasonic point sensor system, a nucleonic gaging system, an ultrasonic torsional wave guide, and an ultrasonic flowmeter. The first three systems provide a direct measurement of propellant quantity remaining, while the fourth system integrates (totalizes) the propellant flow to the engines and infers propellant remaining based on a known initial propellant load. As a result of successful ground and KC-135 tests, two concepts (the ultrasonic point sensor and nucleonic systems) were selected for orbital test in a Shuttle Get-Away-Special experiment. These systems offer high end-of-life accuracy potential, are nonintrusive (external to the tanks and feedlines), and are low in risk because of their good technology base. The Shuttle Get-Away-Special experiment has been assembled and passed flight certification testing in late April 1986.

  3. RF modal quantity gaging

    NASA Astrophysics Data System (ADS)

    Vanleuven, K.

    1989-05-01

    The primary objective is to provide a concept of a radio frequency (RF) modal resonance technique which is being investigated as a method for gaging the quantities of subcritical cryogenic propellants in metallic tanks. Of special interest are the potential applications of the technique to microgravity propellant gaging situations. The results of concept testing using cryogenic oxygen, hydrogen, and nitrogen, as well as paraffin simulations of microgravity fluid orientations, are reported. These test results were positive and showed that the gaging concept was viable.

  4. Ultrasonic Bolt Gage

    NASA Technical Reports Server (NTRS)

    Gleman, Stuart M. (Inventor); Rowe, Geoffrey K. (Inventor)

    1999-01-01

    An ultrasonic bolt gage is described which uses a crosscorrelation algorithm to determine a tension applied to a fastener, such as a bolt. The cross-correlation analysis is preferably performed using a processor operating on a series of captured ultrasonic echo waveforms. The ultrasonic bolt gage is further described as using the captured ultrasonic echo waveforms to perform additional modes of analysis, such as feature recognition. Multiple tension data outputs, therefore, can be obtained from a single data acquisition for increased measurement reliability. In addition, one embodiment of the gage has been described as multi-channel, having a multiplexer for performing a tension analysis on one of a plurality of bolts.

  5. Stream-gaging cableways

    USGS Publications Warehouse

    Wagner, C. Russell

    1995-01-01

    This manual provides a series of standard designs for stream-gaging cableways used by the U.S. Geological Survey (USGS). It provides helpful information on construction, inspection, and maintenance of cableways.

  6. Compensated High Temperature Strain Gage

    NASA Technical Reports Server (NTRS)

    1994-01-01

    A device for measuring strain in substrates at high temperatures in which the thermally induced apparent strain is nulled is described. Two gages are used, one active gage and one compensating gage. Both gages are placed on the substrate to be gaged; the active gage is attached such that it responds to mechanical and thermally induced apparent strain while the compensating gage is attached such that it does not respond to mechanical strain and and measures only thermally induced apparent strain. A thermal blanket is placed over the two gages to maintain the gages at the same temperature. The two gages are wired as adjacent arms of a wheatstone bridge which nulls the thermally induced apparent strain giving a true reading of the mechanical strain in the substrate.

  7. Airflow control system

    DOEpatents

    Motszko, Sean Ronald; McEnaney, Ryan Patrick; Brush, Jeffrey Alan; Zimmermann, Daniel E.

    2007-03-13

    A dual airflow control system for an environment having a first air zone and a second air zone. The system includes a first input device operable to generate a first input signal indicative of a desired airflow to the first zone and a second input device operable to generate a second input signal indicative of a desired airflow to the second zone. First and second flow regulators are configured to regulate airflow to the first and second zones, respectively, such that the first and second regulators selectively provide the airflow to each of the first and second zones based on the first and second input signals. A single actuator is associated with the first and second flow regulators. The actuator is operable to simultaneously actuate the first and second flow regulators based on an input from the first and second input devices to allow the desired airflows to the first and the second zones.

  8. Elevated temperature strain gages

    NASA Technical Reports Server (NTRS)

    Brittain, J. O.; Geslin, D.; Lei, J. F.

    1986-01-01

    One of the goals of the HOST Program is the development of electrical resistance strain gages for static strain measurements at temperatures equal to or greater than 1273 K. Strain gage materials must have a reproducible or predictable response to temperature, time and strain. It is the objective of this research to investigate criteria for the selection of materials for such applications through electrical properties studies. The results of the investigation of two groups of materials, refractory compounds and binary alloy solid solutions are presented.

  9. Evaluation results of the 700 deg C Chinese strain gages

    NASA Technical Reports Server (NTRS)

    Hobart, H. F.

    1984-01-01

    There is a continuing interest and need for resistance strain gages capable of making static strain measurements on components located in the hot section of gas turbine engines. A paper by Tsen-tai Wu describes the development and evaluation of high temperature gauges fabricated from specially developed Fe-Cr-Al-V-Ti-Y alloy wire. Several of these gages and a quantity of P12-2 ceramic adhesive were purchased for evaluation. Nine members of the aircraft turbine engine community were invited to participate in an evaluation of these gages. Each participant was sent one strain gage, a small amount of ceramic adhesive, instructions for mounting the gage on a test beam, and a set of suggestions for the experiment. Data on gage factor variation with temperature, apparent strain, and drift are discussed.

  10. Strain gage barometric transmitter

    NASA Technical Reports Server (NTRS)

    Viton, P.

    1977-01-01

    A strain gage barometric transmitter for measuring the atmospheric pressure in severe environmental conditions is described. This equipment specifications are presented and its performance assessed. It is shown that this barometric sensor can measure the atmospheric pressure with a precision of 0.5 mb during a 6 month period.

  11. Assessing multizone airflow software

    SciTech Connect

    Lorenzetti, D.M.

    2001-12-01

    Multizone models form the basis of most computer simulations of airflow and pollutant transport in buildings. In order to promote computational efficiency, some multizone simulation programs, such as COMIS and CONTAM, restrict the form that their flow models may take. While these tools allow scientists and engineers to explore a wide range of building airflow problems, increasingly their use has led to new questions not answerable by the current generation of programs. This paper, directed at software developers working on the next generation of building airflow models, identifies structural aspects of COMIS and related programs that prevent them from easily incorporating desirable new airflow models. The paper also suggests criteria for evaluating alternate simulation environments for future modeling efforts.

  12. Defining Airflow Obstruction

    PubMed Central

    Eschenbacher, William L.

    2016-01-01

    Airflow obstruction has been defined using spirometric test results when the forced expiratory volume in 1 second (FEV1) to forced vital capacity (FVC) ratio is below a fixed cutoff (<70%) or lower limits of normal (LLN) from reference equations that are based on values from a normal population. However, similar to other positive or abnormal diagnostic test results that are used to identify the presence of disease, perhaps airflow obstruction should be defined based on the values of FEV1/FVC for a population of individuals with known disease such as chronic obstructive pulmonary disease (COPD). Unfortunately, we do not know such a distribution of values of FEV1/FVC for patients with COPD since there is no gold standard for this syndrome or condition. Yet, we have used this physiologic definition of airflow obstruction based on a normal population to identify patients with COPD. In addition, we have defined airflow obstruction as either being present or absent. Instead, we should use a different approach to define airflow obstruction based on the probability or likelihood that the airflow obstruction is present which in turn would give us the probability or likelihood of a disease state such as COPD. PMID:27239557

  13. Gage for micromachining system

    DOEpatents

    Miller, Donald M.

    1979-02-27

    A gage for measuring the contour of the surface of an element of a micromachining tool system and of a work piece machined by the micromachining tool system. The gage comprises a glass plate containing two electrical contacts and supporting a steel ball resting against the contacts. As the element or workpiece is moved against the steel ball, the very slight contact pressure causes an extremely small movement of the steel ball which breaks the electrical circuit between the two contacts. The contour information is supplied to a dedicated computer controlling the micromachining tool so that the computer knows the contour of the element and the work piece to an accuracy of .+-. 25 nm. The micromachining tool system with X- and omega-axes is used to machine spherical, aspherical, and irregular surfaces with a maximum contour error of 100 nanometers (nm) and surface waviness of no more than 0.8 nm RMS.

  14. Superlattice strain gage

    DOEpatents

    Noel, Bruce W.; Smith, Darryl L.; Sinha, Dipen N.

    1990-01-01

    A strain gage comprising a strained-layer superlattice crystal exhibiting piezoelectric properties is described. A substrate upon which such a strained-layer superlattice crystal has been deposited is attached to an element to be monitored for strain. A light source is focused on the superlattice crystal and the light reflected from, passed through, or emitted from the crystal is gathered and compared with previously obtained optical property data to determine the strain in the element.

  15. Superlattice strain gage

    DOEpatents

    Noel, B.W.; Smith, D.L.; Sinha, D.N.

    1988-06-28

    A strain gage comprising a strained-layer superlattice crystal exhibiting piezoelectric properties is described. A substrate upon which such a strained-layer superlattice crystal has been deposited is attached to an element to be monitored for strain. A light source is focused on the superlattice crystal and the light reflected from, passed through, or emitted from the crystal is gathered and compared with previously obtained optical property data to determine the strain in the element. 8 figs.

  16. The apparent strain stability and repeatability of a BCL3 resistance strain gage

    NASA Astrophysics Data System (ADS)

    Lei, Jih-Fen

    1991-02-01

    Experiments were conducted at NASA-Lewis to study the effect of microstructural instability on the apparent strain stability and reproducibility of a BCL3 resistance strain gage. The resistance drift of the gage at various temperatures in the phase transition temperature range (PTTR) was measured. The effects of the heating and cooling rates with which the gage passed through the PTTR on the apparent strain characteristics of the gage were also studied. BCL3 gage, like other Fe-Cr-Al based gages, exhibited apparent strain instability in the temperature range of 700 to 1100 F due to the reversible microstructural transition the gage materials experienced in this temperature range. The BCL3 gage had a maximum apparent strain drift in the neighborhood of 770 F with an average drift rate of approx. -440 microstrain/hr in 2 hrs. The use of the BCL3 gage as well as other Fe-Cl-Al based gages for static strain measurements within the PTTR should be avoided unless the time durations in the PTTR are small enough to introduce a neglible drift. The microstructure transition that the BCL3 gage underwent occurred in the temperature range of 750 to 1050 F during heating and around 1000 to 800 F during cooling. The heating rate, and, in particular, the cooling rate with which the gage passed through the PTTR affected the shape and the repeatability of the apparent strain curve of the gage.

  17. Three-in-one gage

    NASA Technical Reports Server (NTRS)

    Garecht, D. M.

    1988-01-01

    The Three-in-One Gage is a three way gage designed to measure pressure, temperature, and displacement at the same port continuously. The Two-in-One Gage is a two way gage designed to measure pressure and temperature in the same port continuously. The Two-in-One is an adaptation of the Three-in-One to incorporate dual seals, however, without the proximity sensor. The Three-in-One is assembled using two Type K thermocouples, 1 Kulite Pressure Transducer, and one Kaman Proximity Displacement Sensor. Tests of performance were completed.

  18. Embedded gage impact study

    NASA Technical Reports Server (NTRS)

    Schramm, S. W.; Daniel, I. M.

    1984-01-01

    Impact damage in graphite/epoxy laminates was characterized and transient strain history during impact was correlated. The material investigated was AS-4/3501-6 graphite/epoxy. Eight-ply and sixteen-ply quasi-isotropic laminates of 45/0/-45/90 sub s and 45/0/-45/90 sub 2s layups were fabricated with strain gages embedded between plies during the strain gages and leads from the highly conductive graphite fibers. The specimens were circular plates 12.7 cm (5 in.) in diameter and clamped along their circumference. The specimens were impacted with a 185 gm impactor, dropped from heights of 1.20 m and 1.65 m. An accelerometer was attached to the back surface of the specimen opposite the impact point and was used to trigger the recording instrumentation. The transient strain data were recorded with an eight channel waveform digitizer capable of sampling data at 0.5 microsec intervals. The data were stored, processed, and plotted by means of a microcomputer. Transient strain data were correlated with results from ultrasonic inspection of the specimens.

  19. Strain-gage applications in wind tunnel balances

    NASA Astrophysics Data System (ADS)

    Mole, P. J.

    1990-10-01

    Six-component balances used in wind tunnels for precision measurements of air loads on scale models of aircraft and missiles are reviewed. A beam moment-type balance, two-shell balance consisting of an outer shell and inner rod, and air-flow balances used in STOL aircraft configurations are described. The design process, fabrication, gaging, single-gage procedure, and calibration of balances are outlined, and emphasis is placed on computer stress programs and data-reduction computer programs. It is pointed out that these wind-tunnel balances are used in applications for full-scale flight vehicles. Attention is given to a standard two-shell booster balance and an adaptation of a wind-tunnel balance employed to measure the simulated distributed launch loads of a payload in the Space Shuttle.

  20. Inexpensive Bolt-Load Gage

    NASA Technical Reports Server (NTRS)

    Long, M. J.

    1983-01-01

    "Built-in" gage determines whether large bolt or stud has been torqued to desired load and provides for continuous inspection to ensure proper load is being maintained. Gage detects longitudinal stress/strain bolt; requires no electronic or sonic test equipment.

  1. Electronic Force Gage for Welders

    NASA Technical Reports Server (NTRS)

    Bradley, J. W.; Gates, G.

    1983-01-01

    Welding force monitored in process. Electronic force gage uses strain gage on deformable member. Oscilloscope trace of welding force photographed and compared with standard trace during calibration and troubleshooting of resistance welding equipment. Adaptable to small scale resistance welding in electronics industry.

  2. Gage for 3-d contours

    NASA Technical Reports Server (NTRS)

    Haynie, C. C.

    1980-01-01

    Simple gage, used with template, can help inspectors determine whether three-dimensional curved surface has correct contour. Gage was developed as aid in explosive forming of Space Shuttle emergency-escape hatch. For even greater accuracy, wedge can be made of metal and calibrated by indexing machine.

  3. High temperature strain gages

    NASA Technical Reports Server (NTRS)

    Gregory, Otto J. (Inventor); You, Tao (Inventor)

    2011-01-01

    A ceramic strain gage based on reactively sputtered indium-tin-oxide (ITO) thin films is used to monitor the structural integrity of components employed in aerospace propulsion systems operating at temperatures in excess of 1500.degree. C. A scanning electron microscopy (SEM) of the thick ITO sensors reveals a partially sintered microstructure comprising a contiguous network of submicron ITO particles with well defined necks and isolated nanoporosity. Densification of the ITO particles was retarded during high temperature exposure with nitrogen thus stabilizing the nanoporosity. ITO strain sensors were prepared by reactive sputtering in various nitrogen/oxygen/argon partial pressures to incorporate more nitrogen into the films. Under these conditions, sintering and densification of the ITO particles containing these nitrogen rich grain boundaries was retarded and a contiguous network of nano-sized ITO particles was established.

  4. Fluid quantity gaging

    NASA Technical Reports Server (NTRS)

    Mord, Allan J.; Snyder, Howard A.; Kilpatrick, Kathleen A.; Hermanson, Lynn A.; Hopkins, Richard A.; Vangundy, Donald A.

    1988-01-01

    A system for measuring the mass of liquid in a tank on orbit with 1 percent accuracy was developed and demonstrated. An extensive tradeoff identified adiabatic compression as the only gaging technique that is independent of gravity or its orientation, and of the size and distribution of bubbles in the tank. This technique is applicable to all Earth-storable and cryogenic liquids of interest for Space Station use, except superfluid helium, and can be applied to tanks of any size, shape, or internal structure. Accuracy of 0.2 percent was demonstrated in the laboratory, and a detailed analytical model was developed and verified by testing. A flight system architecture is presented that allows meeting the needs of a broad range of space fluid systems without custom development for each user.

  5. Precision contour gage

    DOEpatents

    Bieg, Lothar F.

    1990-12-11

    An apparatus for gaging the contour of a machined part includes a rotary slide assembly, a kinematic mount to move the apparatus into and out of position for measuring the part while the part is still on the machining apparatus, a linear probe assembly with a suspension arm and a probe assembly including as probe tip for providing a measure of linear displacement of the tip on the surface of the part, a means for changing relative positions between the part and the probe tip, and a means for recording data points representing linear positions of the probe tip at prescribed rotation intervals in the position changes between the part and the probe tip.

  6. Precision contour gage

    DOEpatents

    Bieg, L.F.

    1990-12-11

    An apparatus for gaging the contour of a machined part includes a rotary slide assembly, a kinematic mount to move the apparatus into and out of position for measuring the part while the part is still on the machining apparatus, a linear probe assembly with a suspension arm and a probe assembly including as probe tip for providing a measure of linear displacement of the tip on the surface of the part, a means for changing relative positions between the part and the probe tip, and a means for recording data points representing linear positions of the probe tip at prescribed rotation intervals in the position changes between the part and the probe tip. 5 figs.

  7. Coverage of the Phineas Gage Story in Introductory Psychology Textbooks: Was Gage No Longer Gage?

    ERIC Educational Resources Information Center

    Griggs, Richard A.

    2015-01-01

    Most introductory textbooks discuss the story of Phineas Gage and his terrible accident in which he survived a three-and-a-half-foot-long tamping iron that weighed 13¼ pounds exploding through his head. Twenty-three current introductory textbooks were analyzed for the accuracy of their coverage of Gage's subsequent (post-accident) history and…

  8. Resistance-foil strain-gage technology as applied to composite materials

    NASA Technical Reports Server (NTRS)

    Tuttle, M. E.; Brinson, H. F.

    1984-01-01

    A general review of existing strain-gage technologies as applied to orthotropic-composite materials is given. The specific topics addressed are gage-bonding procedures, transverse-sensitivity effects, errors due to gage misalignment, and temperature-compensation methods. The discussion is supplemented by numerical examples where appropriate. It is shown that the orthotropic behavior of composites can result in experimental error which would not be expected based on practical experience with isotropic materials. In certain cases, the transverse sensitivity of strain gages and/or slight gage misalignment can result in strain-measurement errors exceeding 50 percent.

  9. Bi-directional, buried-wire skin-friction gage

    NASA Technical Reports Server (NTRS)

    Higuchi, H.; Peake, D. J.

    1978-01-01

    A compact, nonobtrusive, bi-directional, skin-friction gage was developed to measure the mean shear stress beneath a three-dimensional boundary layer. The gage works by measuring the heat flux from two orthogonal wires embedded in the surface. Such a gage was constructed and its characteristics were determined for different angles of yaw in a calibration experiment in subsonic flow with a Preston tube used as a standard. Sample gages were then used in a fully three-dimensional turbulent boundary layer on a circular cone at high relative incidence, where there were regimes of favorable and adverse pressure gradients and three-dimensional separation. Both the direction and magnitude of skin friction were then obtained on the cone surface.

  10. Design of a strain-gage probe

    NASA Technical Reports Server (NTRS)

    Kolba, V. M.; Vetter, D. L.

    1969-01-01

    Strain-gage spacer probe uses the deflection of a leaf spring to measure strain in a long, slender beam nondestructively. The selected gage is of the smallest practical size, as thin as possible and yet of a standard type.

  11. Thin film strain gage development program

    NASA Technical Reports Server (NTRS)

    Grant, H. P.; Przybyszewski, J. S.; Anderson, W. L.; Claing, R. G.

    1983-01-01

    Sputtered thin-film dynamic strain gages of 2 millimeter (0.08 in) gage length and 10 micrometer (0.0004 in) thickness were fabricated on turbojet engine blades and tested in a simulated compressor environment. Four designs were developed, two for service to 600 K (600 F) and two for service to 900 K (1200 F). The program included a detailed study of guidelines for formulating strain-gage alloys to achieve superior dynamic and static gage performance. The tests included gage factor, fatigue, temperature cycling, spin to 100,000 G, and erosion. Since the installations are 30 times thinner than conventional wire strain gage installations, and any alteration of the aerodynamic, thermal, or structural performance of the blade is correspondingly reduced, dynamic strain measurement accuracy higher than that attained with conventional gages is expected. The low profile and good adherence of the thin film elements is expected to result in improved durability over conventional gage elements in engine tests.

  12. Microprocessor-based multichannel flutter monitor using dynamic strain gage signals

    NASA Technical Reports Server (NTRS)

    Smalley, R. R.

    1976-01-01

    Two microprocessor-based multichannel monitors for monitoring strain gage signals during aerodynamic instability (flutter) testing in production type turbojet engines were described. One system monitors strain gage signals in the time domain and gives an output indication whenever the signal amplitude of any gage exceeds a pre-set alarm or abort level for that particular gage. The second system monitors the strain gage signals in the frequency domain and therefore is able to use both the amplitude and frequency information. Thus, an alarm signal is given whenever the spectral content of the strain gage signal exceeds, at any point, its corresponding amplitude vs. frequency limit profiles. Each system design is described with details on design trade-offs, hardware, software, and operating experience.

  13. The Development of Electrical Strain Gages

    NASA Technical Reports Server (NTRS)

    De Forest, A V; Leaderman, H

    1940-01-01

    The design, construction, and properties of an electrical-resistance strain gage consisting of fine wires molded in a laminated plastic are described. The properties of such gages are discussed and also the problems of molding of wires in plastic materials, temperature compensation, and cementing and removal of the gages. Further work to be carried out on the strain gage, together with instrument problems, is discussed.

  14. Stage measurement at gaging stations

    USGS Publications Warehouse

    Sauer, Vernon B.; Turnipseed, D. Phil

    2010-01-01

    Stream and reservoir stage are critical parameters in the computation of stream discharge and reservoir volume, respectively. In addition, a record of stream stage is useful in the design of structures that may be affected by stream elevation, as well as for the planning for various uses of flood plains. This report describes equipment and methodology for the observation, sensing, and recording of stage in streams and reservoirs. Although the U.S. Geological Survey (USGS) still uses the traditional, basic stilling-well float system as a predominant gaging station, modern electronic stage sensors and water-level recorders are now commonly used. Bubble gages coupled with nonsubmersible pressure transducers eliminate the need for stilling wells. Submersible pressure transducers have become common in use for the measurement of stage in both rivers and lakes. Furthermore, noncontact methods, such as radar, acoustic, and laser methods of sensing water levels, are being developed and tested, and in the case of radar, are commonly used for the measurement of stage. This report describes commonly used gaging-station structures, as well as the design and operation of gaging stations. Almost all of the equipment and instruments described in this report will meet the accuracy standard set by the USGS Office of Surface Water (OSW) for the measurement of stage for most applications, which is ?0.01 foot (ft) or 0.2 percent of the effective stage. Several telemetry systems are used to transmit stage data from the gaging station to the office, although satellite telemetry has become the standard. These telemetry systems provide near real-time stage data, as well as other information that alerts the hydrographer to extreme or abnormal events, and instrument malfunctions.

  15. 49 CFR 213.53 - Gage.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Gage. 213.53 Section 213.53 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION TRACK SAFETY STANDARDS Track Geometry § 213.53 Gage. (a) Gage is measured between the heads of...

  16. 49 CFR 213.53 - Gage.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Gage. 213.53 Section 213.53 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION TRACK SAFETY STANDARDS Track Geometry § 213.53 Gage. (a) Gage is measured between the heads of...

  17. Strain gage installation and survivability on geosynthetics used in flexible pavements

    NASA Astrophysics Data System (ADS)

    Brooks, Jeremy A.

    The use of foil type strain gages on geosynthetics is poorly documented. In addition, very few individuals are versed in proper installation techniques or calibration methods. Due to the limited number of knowledgeable technicians there is no information regarding the susceptibility of theses gages to errors in installation by inexperienced installers. Also lacking in the documentation related to the use of foil type strain gages on geosynthetics is the survivability of the gages in field conditions. This research documented procedures for installation, calibration, and survivability used by the project team to instruments a full scale field installation in Marked Tree, AR. This research also addressed sensitivity to installation errors on both geotextile and geogrid. To document the process of gage installation an experienced technician, Mr. Joe Ables, formerly of the UASCE Waterways Experiment Station, was consulted. His techniques were combined with those discovered in related literature and those developed by the research team to develop processes that were adaptable to multiple gage geometries and parent geosynthetics. These processes were described and documented in a step by step manner with accompanying photographs, which should allow virtually anyone with basic electronics knowledge to install these gages properly. Calibration of the various geosynthetic / strain gage combinations was completed using wide width tensile testing on multiple samples of each material. The tensile testing process was documented and analyzed using digital photography to analyze strain on the strain gage itself. Calibration factors for each geosynthtics used in the full scale field testing were developed. In addition, the process was thoroughly documented to allow future researchers to calibrate additional strain gage and geosynthetic combinations. The sensitivity of the strain gages to installation errors was analyzed using wide width tensile testing and digital photography to

  18. Numerical simulation of laboratory fume hood airflow performance

    SciTech Connect

    Kirkpatrick, A.T.; Reither, R.

    1998-12-31

    A three-dimensional computational fluid dynamics (CFD) analysis has been used to predict airflow patterns in laboratory fume hoods. The simulation includes bypass fume hood primary operational features including the top and bottom bypasses, front airfoils, and rear-slotted baffles. All results were validated experimentally, and the simulation was found to adequately predict fume hood airflow patterns. The results indicate that fume hood flow patterns are highly dependent on inlet flow boundary conditions so that the computation must include the near field room airflow. Additionally, the study included the effects on the fume hood airflow of sash height changes, an operator positioned outside the fume hood, and equipment within the main fume hood chamber. It was shown that for conditions of a fully open sash height, a person in front of the fume hood, and an object inside the fume hood, the fume hood experiences a loss of containment of the flow.

  19. Structure of the airflow above surface waves

    NASA Astrophysics Data System (ADS)

    Buckley, Marc; Veron, Fabrice

    2016-04-01

    Weather, climate and upper ocean patterns are controlled by the exchanges of momentum, heat, mass, and energy across the ocean surface. These fluxes are, in turn, influenced by the small-scale physics at the wavy air-sea interface. We present laboratory measurements of the fine-scale airflow structure above waves, achieved in over 15 different wind-wave conditions, with wave ages Cp/u* ranging from 1.4 to 66.7 (where Cp is the peak phase speed of the waves, and u* the air friction velocity). The experiments were performed in the large (42-m long) wind-wave-current tank at University of Delaware's Air-Sea Interaction laboratory (USA). A combined Particle Image Velocimetry and Laser Induced Fluorescence system was specifically developed for this study, and provided two-dimensional airflow velocity measurement as low as 100 um above the air-water interface. Starting at very low wind speeds (U10~2m/s), we directly observe coherent turbulent structures within the buffer and logarithmic layers of the airflow above the air-water interface, whereby low horizontal velocity air is ejected away from the surface, and higher velocity fluid is swept downward. Wave phase coherent quadrant analysis shows that such turbulent momentum flux events are wave-phase dependent. Airflow separation events are directly observed over young wind waves (Cp/u*<3.7) and counted using measured vorticity and surface viscous stress criteria. Detached high spanwise vorticity layers cause intense wave-coherent turbulence downwind of wave crests, as shown by wave-phase averaging of turbulent momentum fluxes. Mean wave-coherent airflow motions and fluxes also show strong phase-locked patterns, including a sheltering effect, upwind of wave crests over old mechanically generated swells (Cp/u*=31.7), and downwind of crests over young wind waves (Cp/u*=3.7). Over slightly older wind waves (Cp/u* = 6.5), the measured wave-induced airflow perturbations are qualitatively consistent with linear critical layer

  20. Development of high temperature strain gages

    NASA Technical Reports Server (NTRS)

    Lemcoe, M. M.

    1973-01-01

    High temperature electric resistance wire strain gages were developed and evaluated for use at temperatures exceeding 922 K (1200 F). A special high temperature strain gage alloy (Fe-25Cr-7.5A1), designated BCL-3, was used to fabricate the gages. Pertinent gage characteristics were determined at temperatures up to 1255 K (1800 F). The results of the evaluation were reported in graphical and tabular form. It was concluded that the gages will perform satisfactorily at temperatures to at least 1089 K (1500 F) for at least one hour.

  1. Airflow models gaining clout

    SciTech Connect

    Post, N.M.

    1994-10-10

    Move over, mock-ups. So long, smoke bombs. Take a walk, wind tunnels. Computational fluid dynamics, a spaceage simulation technique, is gaining velocity in the building community. And the design of inner spaces may never be the same. CFD is an equation-intensive computer modeling method that can simulate transient and steady-state airflow patterns and temperature gradients, indoors or out. CFD is used to downsize heating, ventilating and air conditioning systems, locate air outlets, and in general, create spaces that offer creature comfort, provide quality air and use less energy. The method is good for new construction, retrofits and forensic work, for example to investigate a building fire or a contaminant. In a room, CFD helps engineers consider, over a period of time, the combined impacts of ventilation, size, shape, contents, weather, even fenestration. For its first decade or two, CFD stayed the near-exclusive domain of aerospace, defense and electronics. With few exceptions, the building community could not afford the supercomputers that were needed to run the tens of thousands of equations involved. However, in the past few years, thanks to the increasing power and decreasing cost of computers, CFD simulation became practical. Curtain wall designers are even using it, though not without some controversy. Indoor air quality specialists, smoke and fire-spread researchers, laboratory designers, energy engineers, code writers, architects, and plant and building engineers are uncharacteristically upbeat about the tool. {open_quotes}CFD modeling is so many light years ahead of design tools that exist,{close_quotes} says Mariano Rodriguez, director of research and development for architect The Hillier Group, Princeton, N.J. {open_quotes}It`s the next step up from a wind tunnel test, and you don`t need a $300,000 wind tunnel.{close_quotes}

  2. High Temperature Capacitive Strain Gage

    NASA Technical Reports Server (NTRS)

    Wnuk, Stephen P., Jr.; Wnuk, Stephen P., III; Wnuk, V. P.

    1990-01-01

    Capacitive strain gages designed for measurements in wind tunnels to 2000 F were built and evaluated. Two design approaches were followed. One approach was based on fixed capacitor plates with a movable ground plane inserted between the plates to effect differential capacitive output with strain. The second approach was based on movable capacitor plates suspended between sapphire bearings, housed in a rugged body, and arranged to operate as a differential capacitor. A sapphire bearing gage (1/4 in. diameter x 1 in. in size) was built with a range of 50,000 and a resolution of 200 microstrain. Apparent strain on Rene' 41 was less than + or - 1000 microstrain from room temperature to 2000 F. Three gage models were built from the Ground Plane Differential concept. The first was 1/4 in. square by 1/32 in. high and useable to 700 F. The second was 1/2 in. square by 1/16 in. high and useable to 1440 F. The third, also 1/2 in. square by 1/16 in. high was expected to operate in the 1600 to 2000 F range, but was not tested because time and funding ended.

  3. High-Temperature Adhesive Strain Gage Developed

    NASA Technical Reports Server (NTRS)

    Pereira, J. Michael; Roberts, Gary D.

    1997-01-01

    Researchers at the NASA Lewis Research Center have developed a unique strain gage and adhesive system for measuring the mechanical properties of polymers and polymer composites at elevated temperatures. This system overcomes some of the problems encountered in using commercial strain gages and adhesives. For example, typical commercial strain gage adhesives require a postcure at temperatures substantially higher than the maximum test temperature. The exposure of the specimen to this temperature may affect subsequent results, and in some cases may be higher than the glass-transition temperature of the polymer. In addition, although typical commercial strain gages can be used for short times at temperatures up to 370 C, their long-term use is limited to 230 C. This precludes their use for testing some high-temperature polyimides near their maximum temperature capability. Lewis' strain gage and adhesive system consists of a nonencapsulated, unbacked gage grid that is bonded directly to the polymer after the specimen has been cured but prior to the normal postcure cycle. The gage is applied with an adhesive specially formulated to cure under the specimen postcure conditions. Special handling, mounting, and electrical connection procedures were developed, and a fixture was designed to calibrate each strain gage after it was applied to a specimen. A variety of tests was conducted to determine the performance characteristics of the gages at elevated temperatures on PMR-15 neat resin and titanium specimens. For these tests, which included static tension, thermal exposure, and creep tests, the gage and adhesive system performed within normal strain gage specifications at 315 C. An example of the performance characteristics of the gage can be seen in the figure, which compares the strain gage measurement on a polyimide specimen at 315 C with an extensometer measurement.

  4. Low TCR nanocomposite strain gages

    NASA Technical Reports Server (NTRS)

    Gregory, Otto J. (Inventor); Chen, Ximing (Inventor)

    2012-01-01

    A high temperature thin film strain gage sensor capable of functioning at temperatures above 1400.degree. C. The sensor contains a substrate, a nanocomposite film comprised of an indium tin oxide alloy, zinc oxide doped with alumina or other oxide semiconductor and a refractory metal selected from the group consisting of Pt, Pd, Rh, Ni, W, Ir, NiCrAlY and NiCoCrAlY deposited onto the substrate to form an active strain element. The strain element being responsive to an applied force.

  5. Inflatable device for installing strain gage bridges

    NASA Technical Reports Server (NTRS)

    Cook, C. E.; Smith, G. E.; Monaghan, R. C. (Inventor)

    1983-01-01

    Methods and devices for installing in a tubular shaft multiple strain gages are disclosed with focus on a method and a device for pneumatically forcing strain gages into seated engagement with the internal surfaces of a tubular shaft in an installation of multiple strain gages in a tubular shaft. The strain gages or other electron devices are seated in a template-like component which is wrapped about a pneumatically expansible body. The component is inserted into a shaft and the body is pneumatically expanded after a suitable adhesive was applied to the surfaces.

  6. MICROPROCESSOR CONTROL OF ROTOGRAVURE AIRFLOWS

    EPA Science Inventory

    The report discusses the technical and economic viability of using micro-processor-based control technology to collect volatile organic compound (VOC) emissions from a paper coating operation. The microprocessor-based control system monitors and controls both the airflow rate and...

  7. Strain gage performance above 1033 K

    NASA Technical Reports Server (NTRS)

    Nichols, D. W.

    1971-01-01

    Study provides compendium of test methods and results which may be used in evaluating high temperature environment gage behavior. Tests include resistance to ground and drift rate and gage factor variation as temperature function. Variation ranged from zero at room temperature (297 K) to 14.5 percent at 1053 K.

  8. 49 CFR 213.323 - Track gage.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Track gage. 213.323 Section 213.323 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION TRACK SAFETY STANDARDS Train Operations at Track Classes 6 and Higher § 213.323 Track gage....

  9. 49 CFR 213.323 - Track gage.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Track gage. 213.323 Section 213.323 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION TRACK SAFETY STANDARDS Train Operations at Track Classes 6 and Higher § 213.323 Track gage....

  10. Strain gage network distinguishes between thermal and mechanical deformations

    NASA Technical Reports Server (NTRS)

    Cepollina, F. J.

    1966-01-01

    Strain gage network measures the thermal coefficient of linear expansion of composite metal structures. The network consists of a test gage and two dummy gages arranged to distinguish thermally induced deformation from mechanical strain.

  11. Real-time visualization and analysis of airflow field by use of digital holography

    NASA Astrophysics Data System (ADS)

    Di, Jianglei; Wu, Bingjing; Chen, Xin; Liu, Junjiang; Wang, Jun; Zhao, Jianlin

    2013-04-01

    The measurement and analysis of airflow field is very important in fluid dynamics. For airflow, smoke particles can be added to visually observe the turbulence phenomena by particle tracking technology, but the effect of smoke particles to follow the high speed airflow will reduce the measurement accuracy. In recent years, with the advantage of non-contact, nondestructive, fast and full-field measurement, digital holography has been widely applied in many fields, such as deformation and vibration analysis, particle characterization, refractive index measurement, and so on. In this paper, we present a method to measure the airflow field by use of digital holography. A small wind tunnel model made of acrylic glass is built to control the velocity and direction of airflow. Different shapes of samples such as aircraft wing and cylinder are placed in the wind tunnel model to produce different forms of flow field. With a Mach-Zehnder interferometer setup, a series of digital holograms carrying the information of airflow filed distributions in different states are recorded by CCD camera and corresponding holographic images are numerically reconstructed from the holograms by computer. Then we can conveniently obtain the velocity or pressure information of the airflow deduced from the quantitative phase information of holographic images and visually display the airflow filed and its evolution in the form of a movie. The theory and experiment results show that digital holography is a robust and feasible approach for real-time visualization and analysis of airflow field.

  12. Zero-gravity quantity gaging system

    NASA Technical Reports Server (NTRS)

    1989-01-01

    The Zero-Gravity Quantity Gaging System program is a technology development effort funded by NASA-LeRC and contracted by NASA-JSC to develop and evaluate zero-gravity quantity gaging system concepts suitable for application to large, on-orbit cryogenic oxygen and hydrogen tankage. The contract effective date was 28 May 1985. During performance of the program, 18 potential quantity gaging approaches were investigated for their merit and suitability for gaging two-phase cryogenic oxygen and hydrogen in zero-gravity conditions. These approaches were subjected to a comprehensive trade study and selection process, which found that the RF modal quantity gaging approach was the most suitable for both liquid oxygen and liquid hydrogen applications. This selection was made with NASA-JSC concurrence.

  13. Non-Contact Gaging with Laser Probe

    SciTech Connect

    Clinesmith, Mike

    2009-03-20

    A gage has been constructed using conventional (high end) components for the application of measuring fragile syntactic foam parts in a non-contact mode. Success with this approach has been achieved through a novel method of transferring (mapping) high accuracy local measurements of a coated aluminum master, taken on a Leitz Coordinate Measurement Machine (CMM), to the gage software system. The mapped data is then associated with local voltage readings from two (inner and outer) laser triangulating probes. This couples discreet laser probe offset and linearity characteristics to the measured master geometry. The gage software compares real part measured data against the master data to provide non-contact part inspection that results in a high accuracy and low uncertainty performance. Uncertainty from the part surface becomes the prevailing contributor to the gaging process. The gaging process provides a high speed, hands off measurement with nearly zero impedance.

  14. Effect of Airflows on Repetitive Nanosecond Volume Discharges

    NASA Astrophysics Data System (ADS)

    Tang, Jingfeng; Wei, Liqiu; Huo, Yuxin; Song, Jian; Yu, Daren; Zhang, Chaohai

    2016-03-01

    Atmospheric pressure discharges excited by repetitive nanosecond pulses have attracted significant attention for various applications. In this paper, a plate-plate discharge with airflows is excited by a repetitive nanosecond pulse generator. Under different experiment conditions, the applied voltages, discharge currents, and discharge images are recorded. The plasma images presented here indicate that the volume discharge modes vary with airflow speeds, and a diffuse and homogeneous volume discharge occurs at the speed of more than 35 m/s. The role of airflows provides different effects on the 2-stage pulse discharges. The 1st pulse currents nearly maintain consistency for different airflow speeds. However, the 2nd pulse current has a change trend of first decreasing and then rapidly increasing, and the value difference for 2nd pulse currents is about 20 A under different airflows. In addition, the experimental results are discussed according to the electrical parameters and discharge images. supported by National Natural Science Foundation of China (Nos. 51006027, 51437002, and 51477035)

  15. Minimum airflow reset of single-duct VAV terminal boxes

    NASA Astrophysics Data System (ADS)

    Cho, Young-Hum

    applied to actual systems for performance validation. The results of the theoretical analysis, numeric simulations, and experiments show that the optimal control algorithms can automatically identify the minimum rate of heating airflow under actual working conditions. Improved control helps to stabilize room air temperatures. The vertical difference in the room air temperature was lower than the comfort value. Measurements of room CO2 levels indicate that when the minimum airflow set point was reduced it did not adversely affect the indoor air quality. According to the measured energy results, optimal control algorithms give a lower rate of reheating energy consumption than conventional controls.

  16. Visual exploration of nasal airflow.

    PubMed

    Zachow, Stefan; Muigg, Philipp; Hildebrandt, Thomas; Doleisch, Helmut; Hege, Hans-Christian

    2009-01-01

    Rhinologists are often faced with the challenge of assessing nasal breathing from a functional point of view to derive effective therapeutic interventions. While the complex nasal anatomy can be revealed by visual inspection and medical imaging, only vague information is available regarding the nasal airflow itself: Rhinomanometry delivers rather unspecific integral information on the pressure gradient as well as on total flow and nasal flow resistance. In this article we demonstrate how the understanding of physiological nasal breathing can be improved by simulating and visually analyzing nasal airflow, based on an anatomically correct model of the upper human respiratory tract. In particular we demonstrate how various Information Visualization (InfoVis) techniques, such as a highly scalable implementation of parallel coordinates, time series visualizations, as well as unstructured grid multi-volume rendering, all integrated within a multiple linked views framework, can be utilized to gain a deeper understanding of nasal breathing. Evaluation is accomplished by visual exploration of spatio-temporal airflow characteristics that include not only information on flow features but also on accompanying quantities such as temperature and humidity. To our knowledge, this is the first in-depth visual exploration of the physiological function of the nose over several simulated breathing cycles under consideration of a complete model of the nasal airways, realistic boundary conditions, and all physically relevant time-varying quantities. PMID:19834215

  17. Discharge measurements at gaging stations

    USGS Publications Warehouse

    Turnipseed, D. Phil; Sauer, Vernon B.

    2010-01-01

    The techniques and standards for making discharge measurements at streamflow gaging stations are described in this publication. The vertical axis rotating-element current meter, principally the Price current meter, has been traditionally used for most measurements of discharge; however, advancements in acoustic technology have led to important developments in the use of acoustic Doppler current profilers, acoustic Doppler velocimeters, and other emerging technologies for the measurement of discharge. These new instruments, based on acoustic Doppler theory, have the advantage of no moving parts, and in the case of the acoustic Doppler current profiler, quickly and easily provide three-dimensional stream-velocity profile data through much of the vertical water column. For much of the discussion of acoustic Doppler current profiler moving-boat methodology, the reader is referred to U.S. Geological Survey Techniques and Methods 3-A22 (Mueller and Wagner, 2009). Personal digital assistants (PDAs), electronic field notebooks, and other personal computers provide fast and efficient data-collection methods that are more error-free than traditional hand methods. The use of portable weirs and flumes, floats, volumetric tanks, indirect methods, and tracers in measuring discharge are briefly described.

  18. A magnifying scratch-gage force transducer

    NASA Technical Reports Server (NTRS)

    Scott, C. E.

    1969-01-01

    Single-component scratch-gage transducer incorporates a unique motion magnification scheme to increase the magnitude of the load measuring scratch approximately 15 times over that of conventional models. It is small, load carrying and high in natural frequency.

  19. Geomorphic applications of stream-gage information

    USGS Publications Warehouse

    Juracek, K.E.; Fitzpatrick, F.A.

    2009-01-01

    In the United States, several thousand stream gages provide what typically is the only source of continuous, long-term streamflow and channel-geometry information for the locations being monitored. In this paper, the geomorphic content of stream-gage information, previous and potential applications of stream-gage information in fluvial geomorphic research and various possible limitations are described. Documented applications include studies of hydraulic geometry, channel bankfull characteristics, sediment transport and channel geomorphic response to various types of disturbance. Potential applications include studies to determine the geomorphic effectiveness of large floods and in-stream habitat change in response to disturbance. For certain applications, various spatial, temporal and data limitations may render the stream-gage information of limited use; however, such information often is of considerable value to enable or enhance geomorphic investigations.

  20. 42 CFR 84.82 - Gas pressure gages; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Gas pressure gages; minimum requirements. 84.82...-Contained Breathing Apparatus § 84.82 Gas pressure gages; minimum requirements. (a) Gas pressure gages.... (c) Gas pressure gages other than those specified in paragraphs (a) and (b) of this section shall...

  1. Mechanical responses of rat vibrissae to airflow.

    PubMed

    Yu, Yan S W; Graff, Matthew M; Hartmann, Mitra J Z

    2016-04-01

    The survival of many animals depends in part on their ability to sense the flow of the surrounding fluid medium. To date, however, little is known about how terrestrial mammals sense airflow direction or speed. The present work analyzes the mechanical response of isolated rat macrovibrissae (whiskers) to airflow to assess their viability as flow sensors. Results show that the whisker bends primarily in the direction of airflow and vibrates around a new average position at frequencies related to its resonant modes. The bending direction is not affected by airflow speed or by geometric properties of the whisker. In contrast, the bending magnitude increases strongly with airflow speed and with the ratio of the whisker's arc length to base diameter. To a much smaller degree, the bending magnitude also varies with the orientation of the whisker's intrinsic curvature relative to the direction of airflow. These results are used to predict the mechanical responses of vibrissae to airflow across the entire array, and to show that the rat could actively adjust the airflow data that the vibrissae acquire by changing the orientation of its whiskers. We suggest that, like the whiskers of pinnipeds, the macrovibrissae of terrestrial mammals are multimodal sensors - able to sense both airflow and touch - and that they may play a particularly important role in anemotaxis. PMID:27030774

  2. Dual active surface heat flux gage probe

    NASA Astrophysics Data System (ADS)

    Liebert, Curt H.; Kolodziej, Paul

    1995-02-01

    A unique plug-type heat flux gage probe was tested in the NASA Ames Research Center 2x9 turbulent flow duct facility. The probe was fabricated by welding a miniature dual active surface heat flux gage body to the end of a hollow metal cylindrical bolt containing a metal inner tube. Cooling air flows through the inner tube, impinges onto the back of the gage body and then flows out through the annulus formed between the inner tube and the hollow bolt wall. Heat flux was generated in the duct facility with a Huels arc heater. The duct had a rectangular cross section and one wall was fabricated from 2.54 centimeter thick thermal insulation rigid surface material mounted onto an aluminum plate. To measure heat flux, the probe was inserted through the plate and insulating materials with the from of the gage located flush with the hot gas-side insulation surface. Absorbed heat fluxes measured with the probe were compared with absorbed heat fluxes measured with six water-cooled reference calorimeters. These calorimeters were located in a water-cooled metal duct wall which was located across from the probe position. Correspondence of transient and steady heat fluxes measured with the reference calorimeters and heat flux gage probe was generally within a satisfactory plus or minus 10 percent. This good correspondence was achieved even though the much cooler probe caused a large surface temperature disruption of 1000K between the metal gage and the insulation. However, this temperature disruption did not seriously effect the accuracy of the heat flux measurement. A current application for dual active surface heat flux gages is for transient and steady absorbed heat flux, surface temperature and heat transfer coefficient measurements on the surface of an oxidizer turbine inlet deflector operating in a space shuttle test bed engine.

  3. Airflow measurement inaccuracies in aerosol imaging

    SciTech Connect

    Sirr, S.A.; Miltz-Miller, S.; Notman, D.N.; Boyle, M.J.; Boudreau, R.J.; Loken, M.K.

    1986-04-01

    Aerosol production using inclined compressed air tanks may be subject to error caused by airflow meter variability and by the degree of inclination of the air-flow meter. Since most of these tanks are used in an inclined position, it is important for clinicians to be aware of these errors.

  4. Airflow measurement inaccuracies in aerosol imaging.

    PubMed

    Sirr, S A; Miltz-Miller, S; Notman, D N; Boyle, M J; Boudreau, R J; Loken, M K

    1986-04-01

    Aerosol production using inclined compressed air tanks may be subject to error caused by airflow meter variability and by the degree of inclination of the air-flow meter. Since most of these tanks are used in an inclined position, it is important for clinicians to be aware of these errors. PMID:3952316

  5. Telescoping magnetic ball bar test gage

    DOEpatents

    Bryan, J.B.

    1984-03-13

    A telescoping magnetic ball bar test gage for determining the accuracy of machine tools, including robots, and those measuring machines having non-disengageable servo drives which cannot be clutched out is disclosed. Two gage balls are held and separated from one another by a telescoping fixture which allows them relative radial motional freedom but not relative lateral motional freedom. The telescoping fixture comprises a parallel reed flexure unit and a rigid member. One gage ball is secured by a magnetic socket knuckle assembly which fixes its center with respect to the machine being tested. The other gage ball is secured by another magnetic socket knuckle assembly which is engaged or held by the machine in such manner that the center of that ball is directed to execute a prescribed trajectory, all points of which are equidistant from the center of the fixed gage ball. As the moving ball executes its trajectory, changes in the radial distance between the centers of the two balls caused by inaccuracies in the machine are determined or measured by a linear variable differential transformer (LVDT) assembly actuated by the parallel reed flexure unit. Measurements can be quickly and easily taken for multiple trajectories about several different fixed ball locations, thereby determining the accuracy of the machine. 3 figs.

  6. Telescoping magnetic ball bar test gage

    DOEpatents

    Bryan, James B.

    1984-01-01

    A telescoping magnetic ball bar test gage for determining the accuracy of machine tools, including robots, and those measuring machines having non-disengageable servo drives which cannot be clutched out. Two gage balls (10, 12) are held and separated from one another by a telescoping fixture which allows them relative radial motional freedom but not relative lateral motional freedom. The telescoping fixture comprises a parallel reed flexure unit (14) and a rigid member (16, 18, 20, 22, 24). One gage ball (10) is secured by a magnetic socket knuckle assembly (34) which fixes its center with respect to the machine being tested. The other gage ball (12) is secured by another magnetic socket knuckle assembly (38) which is engaged or held by the machine in such manner that the center of that ball (12) is directed to execute a prescribed trajectory, all points of which are equidistant from the center of the fixed gage ball (10). As the moving ball (12) executes its trajectory, changes in the radial distance between the centers of the two balls (10, 12) caused by inaccuracies in the machine are determined or measured by a linear variable differential transformer (LVDT) assembly (50, 52, 54, 56, 58, 60) actuated by the parallel reed flexure unit (14). Measurements can be quickly and easily taken for multiple trajectories about several different fixed ball (10) locations, thereby determining the accuracy of the machine.

  7. Telescoping magnetic ball bar test gage

    DOEpatents

    Bryan, J.B.

    1982-03-15

    A telescoping magnetic ball bar test gage for determining the accuracy of machine tools, including robots, and those measuring machines having non-disengagable servo drives which cannot be clutched out. Two gage balls are held and separated from one another by a telescoping fixture which allows them relative radial motional freedom but not relative lateral motional freedom. The telescoping fixture comprises a parallel reed flexure unit and a rigid member. One gage ball is secured by a magnetic socket knuckle assembly which fixes its center with respect to the machine being tested. The other gage ball is secured by another magnetic socket knuckle assembly which is engaged or held by the machine in such manner that the center of that ball is directed to execute a prescribed trajectory, all points of which are equidistant from the center of the fixed gage ball. As the moving ball executes its trajectory, changes in the radial distance between the centers of the two balls caused by inaccuracies in the machine are determined or measured by a linear variable differential transformer (LVDT) assembly actuated by the parallel reed flexure unit. Measurements can be quickly and easily taken for multiple trajectories about several different fixed ball locations, thereby determining the accuracy of the machine.

  8. Development of Displacement Gages Exposed to Solid Rocket Motor Internal Environments

    NASA Technical Reports Server (NTRS)

    Bolton, D. E.; Cook, D. J.

    2003-01-01

    The Space Shuttle Reusable Solid Rocket Motor (RSRM) has three non-vented segment-to-segment case field joints. These joints use an interference fit J-joint that is bonded at assembly with a Pressure Sensitive Adhesive (PSA) inboard of redundant O-ring seals. Full-scale motor and sub-scale test article experience has shown that the ability to preclude gas leakage past the J-joint is a function of PSA type, joint moisture from pre-assembly humidity exposure, and the magnitude of joint displacement during motor operation. To more accurately determine the axial displacements at the J-joints, two thermally durable displacement gages (one mechanical and one electrical) were designed and developed. The mechanical displacement gage concept was generated first as a non-electrical, self-contained gage to capture the maximum magnitude of the J-joint motion. When it became feasible, the electrical displacement gage concept was generated second as a real-time linear displacement gage. Both of these gages were refined in development testing that included hot internal solid rocket motor environments and simulated vibration environments. As a result of this gage development effort, joint motions have been measured in static fired RSRM J-joints where intentional venting was produced (Flight Support Motor #8, FSM-8) and nominal non-vented behavior occurred (FSM-9 and FSM-10). This data gives new insight into the nominal characteristics of the three case J-joint positions (forward, center and aft) and characteristics of some case J-joints that became vented during motor operation. The data supports previous structural model predictions. These gages will also be useful in evaluating J-joint motion differences in a five-segment Space Shuttle solid rocket motor.

  9. Rock Springs Site 12 hydraulic/explosive true in situ oil shale fracturing experiment

    SciTech Connect

    Parrish, R.L.; Boade, R.R.; Stevens, A.L.; Long, A. Jr.; Turner, T.F.

    1980-06-01

    The experiment plan involved the creation and characterization of three horizontal hydraulic fractures, followed by the insertion and simultaneous detonation of slurry explosive in the two lower fractures. Core analyses, wellbore logging, and airflow and /sup 85/Kr tracer tests were used for site characterization and assessment of the hydraulic and explosive fracturing. Tiltmeters, wellhead pressure and flow gages, and in-formation pressure, flow and crack-opening sensors were used to monitor hydrofracture creation and explosive insertion. Explosive detonation diagnostic data were taken with stress and time-of-arrival gages and surface and in-formation accelerometers. The post-fracturing assessments indicated that: (1) hydrofracture creation and explosive insertion and detonation were accomplished essentially as planned; (2) induced fractures were randomly distributed through the shale with no extensively fractured regions or dislocation of shale; and (3) enhancement of permeability was limited to enlargement of the explosive-filled fractures.

  10. Continuous, Multielement, Hot-Film Transition Gage

    NASA Technical Reports Server (NTRS)

    Holmes, B.; Mcpherson, J.; Harris, F.; Diamond, J.; Johnson, N.; Chapman, J.

    1986-01-01

    Accurate measurement of location where laminar boundary layer undergoes transition to turbulent one serves many purposes in basic aero-dynamic research and developmental testing. Individual gages must be staggered to prevent formation of turbulence at gages downstream. This arrangement precludes accurate measurements of laminar/turbulent transition regions along streamline. Complete understanding of performance, stability, and control of laminar-flow airplane requires knowledge of transition locations on wing surface, empennage surfaces, fuselage, and nacelles. Visual, acoustic, and electronic methods capable of providing this transition information.

  11. A model for simulating airflow and pollutant dispersion around buildings

    SciTech Connect

    Chan, S T; Lee, R L

    1999-02-24

    A three-dimensional, numerical mode1 for simulating airflow and pollutant dispersion around buildings is described. The model is based on an innovative finite element approach and fully implicit time integration techniques. Linear and nonlinear eddy viscosity/diffusivity submodels are provided for turbulence parameterization. Mode1 predictions for the flow-field and dispersion patterns around a surface-mounted cube are compared with measured data from laboratory experiments.

  12. 46 CFR 197.458 - Gages and timekeeping devices.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... STANDARDS GENERAL PROVISIONS Commercial Diving Operations Periodic Tests and Inspections of Diving Equipment § 197.458 Gages and timekeeping devices. The diving supervisor shall insure that— (a) Each depth gage... device is inspected before diving operations are begun....

  13. 15. VIEW OF GAGE IRRIGATION CANAL NEAR HILLTOP DRIVE AND ...

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

    15. VIEW OF GAGE IRRIGATION CANAL NEAR HILLTOP DRIVE AND BARTON ROAD, SHOWING END OF SIPHON. CANAL FOLLOWS CONTOUR OF HILL UNDER DIRT ROAD - Gage Irrigation Canal, Running from Santa Ana River to Arlington Heights, Riverside, Riverside County, CA

  14. 12. VIEW OF GAGE IRRIGATION CANAL AT HILLTOP DRIVE AND ...

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

    12. VIEW OF GAGE IRRIGATION CANAL AT HILLTOP DRIVE AND BARTON ROAD SHOWING BEGINNING OF SIPHON, DATED '1952' - Gage Irrigation Canal, Running from Santa Ana River to Arlington Heights, Riverside, Riverside County, CA

  15. 46 CFR 197.458 - Gages and timekeeping devices.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... STANDARDS GENERAL PROVISIONS Commercial Diving Operations Periodic Tests and Inspections of Diving Equipment § 197.458 Gages and timekeeping devices. The diving supervisor shall insure that— (a) Each depth gage... device is inspected before diving operations are begun....

  16. 46 CFR 197.458 - Gages and timekeeping devices.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... STANDARDS GENERAL PROVISIONS Commercial Diving Operations Periodic Tests and Inspections of Diving Equipment § 197.458 Gages and timekeeping devices. The diving supervisor shall insure that— (a) Each depth gage... device is inspected before diving operations are begun....

  17. 46 CFR 197.458 - Gages and timekeeping devices.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... STANDARDS GENERAL PROVISIONS Commercial Diving Operations Periodic Tests and Inspections of Diving Equipment § 197.458 Gages and timekeeping devices. The diving supervisor shall insure that— (a) Each depth gage... device is inspected before diving operations are begun....

  18. 46 CFR 197.458 - Gages and timekeeping devices.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... every 6 months; (b) A depth gage is tested when a discrepancy exists in a depth gage reading greater... device is tested when a discrepancy exists in a timekeeping device reading greater than one-quarter of...

  19. 22. Photocopy of photograph (original print at Gage Canal Company ...

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

    22. Photocopy of photograph (original print at Gage Canal Company Office), photographer and date unknown. 'FLUME NO. 9, 'GAGE CANAL SYSTEM,' RIVERSIDE, CAL.' VIEW OF FLUME OVER TEQUESQUITE ARROYO. - California Citrus Heritage Recording Project, Riverside, Riverside County, CA

  20. 24. Photocopy of photograph (original print at Gage Canal Company ...

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

    24. Photocopy of photograph (original print at Gage Canal Company Office), photographer unknown, ca. 1939. VIEW OF SAND PUMP HOUSE AT THE HEAD OF THE GAGE IRRIGATION CANAL - California Citrus Heritage Recording Project, Riverside, Riverside County, CA

  1. 23. Photocopy of photograph (original print at Gage Canal Company ...

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

    23. Photocopy of photograph (original print at Gage Canal Company Office), photographer unknown, ca. 1917. VIEW OF FLUME NO. 3 OF GAGE IRRIGATION CANAL AND NEW 66' REINFORCED CONCRETE PIPELINE - California Citrus Heritage Recording Project, Riverside, Riverside County, CA

  2. 26. Photocopy of photograph (original print at Gage Canal Company ...

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

    26. Photocopy of photograph (original print at Gage Canal Company Office), photographer unknown, ca. 1931. VIEW OF CONSTRUCTION OF GUNITE INVERT SIPHON REPLACING FLUME NO. 10 ON GAGE IRRIGATION CANAL - California Citrus Heritage Recording Project, Riverside, Riverside County, CA

  3. 28. Photocopy of photograph (original print at Gage Canal Company ...

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

    28. Photocopy of photograph (original print at Gage Canal Company Office), photographer unknown, ca. 1913. CONSTRUCTION OF CORE WALL AT MOCKINGBIRD DAM ON THE GAGE IRRIGATION CANAL - California Citrus Heritage Recording Project, Riverside, Riverside County, CA

  4. 27. Photocopy of photograph (original print at Gage Canal Company ...

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

    27. Photocopy of photograph (original print at Gage Canal Company Office), photographer unknown, ca. 1913. TIGHTENING JOINTS AND ADJUSTING PLATES ON STEEL FLUME AT MOCKINGBIRD DAM ON THE GAGE IRRIGATION CANAL - California Citrus Heritage Recording Project, Riverside, Riverside County, CA

  5. 29. Photocopy of photograph (original print at Gage Canal Company ...

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

    29. Photocopy of photograph (original print at Gage Canal Company Office), photographer unknown, ca. 1926. CENTRIFUGAL PUMPS AT OLIVEWOOD PUMPING STATION ON THE GAGE IRRIGATION CANAL - California Citrus Heritage Recording Project, Riverside, Riverside County, CA

  6. Gage tests tube flares quickly and accurately

    NASA Technical Reports Server (NTRS)

    Griffin, F. D.

    1966-01-01

    Flared tube gage with a test cone that is precisely made with a tapering surface to complement the tube flare is capable of determining the accuracy of a tube flare efficiently and economically. This device should improve the speed, efficiency, and accuracy of tube flare inspections.

  7. SAF line pellet gaging. [Secure Automated Fabrication

    SciTech Connect

    Jedlovec, D.R.; Bowen W.W.; Brown, R.L.

    1983-10-01

    Automated and remotely controlled pellet inspection operations will be utilized in the Secure Automated Fabrication (SAF) line. A prototypic pellet gage was designed and tested to verify conformance to the functions and requirements for measurement of diameter, surface flaws and weight-per-unit length.

  8. Latin square three dimensional gage master

    DOEpatents

    Jones, Lynn L.

    1982-01-01

    A gage master for coordinate measuring machines has an nxn array of objects distributed in the Z coordinate utilizing the concept of a Latin square experimental design. Using analysis of variance techniques, the invention may be used to identify sources of error in machine geometry and quantify machine accuracy.

  9. Stream gages threatened by lack of funding

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    The United States Geological Survey (USGS) is hoping that members of the House of Representatives take a careful look at a list it is now circulating that names dozens of specific stream gages that have been scheduled to be constructed, reactivated, or hardened against failure, but that could be delayed if Congress does not appropriate sufficient funding. Forewarned are dozens of congressmen, including those whose districts encompass the Sacramento River at Sacramento, California; Cowskin Creek at Highway 54 at Wichita, Kansas; the Red River at Grand Forks, North Dakota; and the Potomac River at Harpers Ferry, West Virginia.The Clinton Administration has requested a fiscal year 2001 increase of 4 million to USGS' 90 million annual budget for stream gages. The Survey funds about half of the cost of the network, with cost-sharing partners providing the rest. However, a recent House Appropriations Subcommittee mark-up would result in the loss of about 115 gages, which is about 2% of the 7000 gages in the USGS network, according to a brief prepared by the USGS budget office. The subcommittee provides 1.7 million for water activities under the USGS Real Time Hazards Initiative, but fails to cover 2.3 million in pay raises and anticipated uncontrollable costs, the brief indicates.

  10. Experimental evidence of condensation-driven airflow

    NASA Astrophysics Data System (ADS)

    Bunyard, P.; Hodnett, M.; Poveda, G.; Burgos Salcedo, J. D.; Peña, C.

    2015-10-01

    The dominant "convection" model of atmospheric circulation is based on the premise that hot air expands and rises, to be replaced by colder air, thereby creating horizontal surface winds. A recent theory put forward by Makarieva and Gorshkov (2007, 2013) maintains that the primary motive force of atmospheric circulation derives from the intense condensation and sharp pressure reduction that is associated with regions where a high rate of evapotranspiration from natural closed-canopy forests provides the "fuel" for cloud formation. The net result of the "biotic pump" theory is that moist air flows from ocean to land, drawn in by the pressure changes associated with a high rate of condensation. To test the physics underpinning the biotic pump theory, namely that condensation of water vapour, at a sufficiently high rate, results in an uni-directional airflow, a 5 m tall experimental apparatus was designed and built, in which a 20 m3 body of atmospheric air is enclosed inside an annular 14 m long space (a "square donut") around which it can circulate freely, allowing for rotary air flows. One vertical side of the apparatus contains some 17 m of copper refrigeration coils, which cause condensation. The apparatus contains a series of sensors measuring temperature, humidity and barometric pressure every five seconds, and air flow every second. The laws of Newtonian physics are used in calculating the rate of condensation inside the apparatus. The results of more than one hundred experiments show a highly significant correlation, with r2 > 0.9, of airflow and the rate of condensation. The rotary air flows created appear to be consistent both in direction and velocity with the biotic pump hypothesis, the critical factor being the rate change in the partial pressure of water vapour in the enclosed body of atmospheric air. Air density changes, in terms of kinetic energy, are found to be orders of magnitude smaller than the kinetic energy of partial pressure change. The

  11. 27. Detail view of mechanical float gages used to monitor ...

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

    27. Detail view of mechanical float gages used to monitor level of water in the filtration bed reservoir. Gage on left measures water head, gage on right monitors filtration rate. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  12. 42 CFR 84.82 - Gas pressure gages; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... specifications or permits. (e)(1) Stem-type gages shall be readable by sight and by touch and shall have a stem... graduations shall be engraved on the stem of each gage and these graduations shall include readings for empty, one-quarter, one-half, three-quarters, and full. (3) Stem gage readings shall not vary from...

  13. 42 CFR 84.82 - Gas pressure gages; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... specifications or permits. (e)(1) Stem-type gages shall be readable by sight and by touch and shall have a stem... graduations shall be engraved on the stem of each gage and these graduations shall include readings for empty, one-quarter, one-half, three-quarters, and full. (3) Stem gage readings shall not vary from...

  14. 42 CFR 84.82 - Gas pressure gages; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... specifications or permits. (e)(1) Stem-type gages shall be readable by sight and by touch and shall have a stem... graduations shall be engraved on the stem of each gage and these graduations shall include readings for empty, one-quarter, one-half, three-quarters, and full. (3) Stem gage readings shall not vary from...

  15. 46 CFR 98.25-45 - Liquid level gaging device.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Liquid level gaging device. 98.25-45 Section 98.25-45... § 98.25-45 Liquid level gaging device. (a) Each tank shall be fitted with a liquid level gaging device of suitable design to indicate the maximum level to which the tank may be filled with liquid...

  16. 46 CFR 98.25-45 - Liquid level gaging device.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Liquid level gaging device. 98.25-45 Section 98.25-45... § 98.25-45 Liquid level gaging device. (a) Each tank shall be fitted with a liquid level gaging device of suitable design to indicate the maximum level to which the tank may be filled with liquid...

  17. 46 CFR 98.25-45 - Liquid level gaging device.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Liquid level gaging device. 98.25-45 Section 98.25-45... § 98.25-45 Liquid level gaging device. (a) Each tank shall be fitted with a liquid level gaging device of suitable design to indicate the maximum level to which the tank may be filled with liquid...

  18. 46 CFR 98.25-45 - Liquid level gaging device.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Liquid level gaging device. 98.25-45 Section 98.25-45... § 98.25-45 Liquid level gaging device. (a) Each tank shall be fitted with a liquid level gaging device of suitable design to indicate the maximum level to which the tank may be filled with liquid...

  19. 46 CFR 98.25-45 - Liquid level gaging device.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Liquid level gaging device. 98.25-45 Section 98.25-45... § 98.25-45 Liquid level gaging device. (a) Each tank shall be fitted with a liquid level gaging device of suitable design to indicate the maximum level to which the tank may be filled with liquid...

  20. Airflow resistance of selected biomass materials

    SciTech Connect

    Cooper, S.C.; Sumner, H.R.

    1985-01-01

    Pressure drop created when air was forced through beds of selected biomass materials was determined. Materials tested included peanut hulls, peanut hull pellets, maize cobs, and wood shavings, chips and bark. The data were presented as logarithmic plots and equations of pressure drop versus airflow. The airflow resistances of the biomass materials increased with an increase in bulk density and were found to be in the range between values for ear and shelled maize. 12 references.

  1. Palladium-chromium static strain gages for high temperatures

    NASA Technical Reports Server (NTRS)

    Lei, Jih-Fen

    1992-01-01

    An electrical resistance strain gage that can provide accurate static strain measurement to a temperature of 1500 F or above is being developed both in fine wire and thin film forms. The gage is designed to be temperature compensated on any substrate material. It has a dual element: the gage element is a special alloy, palladium-13wt percent chromium (PdCr), and the compensator element is platinum (Pt). Earlier results of a PdCr based wire gage indicated that the apparent strain of this gage can be minimized and the repeatability of the apparent strain can be improved by prestabilizing the gage on the substrate for a long period of time. However, this kind of prestabilization is not practical in many applications and therefore the development of a wire gage which is prestabilized before installation on the substrate is desirable. This paper will present our recent progress in the development of a prestabilized wire gage which can provide meaningful strain data for the first thermal cycle. A weldable PdCr gage is also being developed for field testing where conventional flame-spraying installation can not be applied. This weldable gage is narrower than a previously reported gage, thereby allowing the gage to be more resistant to buckling under compressive loads. Some preliminary results of a prestabilized wire gage flame-sprayed directly on IN100, an engine material, and a weldable gage spot-welded on IN100 and SCS-6/(beta)21-S Titanium Matrix Composite (TMC), a National Aero-Space Plane (NASP) structure material, will be reported. Progress on the development of a weldable thin film gage will also be addressed. The measurement technique and procedures and the lead wire effect will be discussed.

  2. High temperature strain gage technology for hypersonic aircraft development applications

    NASA Technical Reports Server (NTRS)

    Anderson, W. L.; Grant, H. P.

    1992-01-01

    An experimental evaluation of Pd 13 percent Cr and of BCL-3 alloy wire strain gages was conducted on IN100 and Cu 0.15 percent Zr alloy substrates. Testing included apparent strain, drift, gage factor, and creep. Maximum test temperature was 1144 K (1600 F). The PdCr gages incorporated Pt temperature compensation elements. The PdCr gages were found to have good resistance stability below 866 K (1100 F). The BCL 3 gages were found to have good resistance stability above 800 K (981 F), but high drift around 700 K (800 F).

  3. Airflows generated by an impacting drop.

    PubMed

    Bischofberger, Irmgard; Ray, Bahni; Morris, Jeffrey F; Lee, Taehun; Nagel, Sidney R

    2016-03-28

    A drop impacting a solid surface with sufficient velocity will splash and emit many small droplets. However, lowering the ambient air pressure suppresses splashing completely. This effect, robustly found for different liquid and substrate properties, raises the fundamental question of how air affects a spreading drop. In a combined experimental and numerical study we characterize the flow of air induced by the drop after it hits the substrate, using a modified Schlieren optics technique combined with high-speed video imaging and Lattice-Boltzmann simulations. Our experiments reveal the emergence of air structures on different length scales. On large scales, the airflow induced in the drop's wake leads to vortex structures due to interaction with the substrate. On smaller scales, we visualize a ring structure above the outer edge of the spreading liquid generated by the spreading of the drop. Our simulations reveal the interaction between the wake vorticity and the flows originating from the rapidly escaping air from below the impacting drop. We show that the vorticity is governed by a balance between inertial and viscous forces in the air, and is unrelated to the splashing threshold. PMID:26809314

  4. Evaluation of OTT PLUVIO Precipitation Gage versus Belfort Universal Precipitation Gage 5-780 for the National Atmospheric Deposition Program

    USGS Publications Warehouse

    Tumbusch, Mary L.

    2003-01-01

    The National Atmospheric Deposition Program, a cooperative effort supported by Federal, State, and local agencies, and Indian Tribes, was established in 1977 to study atmospheric deposition and its impact on the environment. The program's National Trends Network now includes wet-deposition networks at more than 250 sites across the United States, Canada, Puerto Rico, and the Virgin Islands. Precipitation amounts are currently measured using a Belfort Universal Precipitation Gage 5-780, which involves technology that is more than 50 years old. In 1999, a three-phase study was begun to evaluate several weighing, all-weather precipitation gages to find a possible replacement for the Belfort Universal Precipitation Gage 5-780. One gage that performed consistently well in phase I and II testing was the OTT PLUVIO Precipitation Gage. Phase III of the study, discussed herein, was to determine the accuracy and comparability of the data sets collected by the OTT PLUVIO Precipitation Gages and the existing Belfort Universal Precipitation Gage 5-780. Seven OTT PLUVIO Precipitation Gages were installed at six National Trends Network sites across the country for a data-collection period of approximately 18 months. The NovaLynx Model 260-2510 Standard Rain and Snow Gage also was used, as a reference, at two of the sites. Paired t-tests analysis showed no significant differences in precipitation measurements between the Belfort Universal Precipitation Gage 5-780 and the OTT PLUVIO Precipitation Gages at three of the six sites. When the false positives were removed from the precipitation-event data sets, the gages at all sites were in agreement and the paired t-tests showed the gage measurements were not significantly different. A false positive is defined as a zero response from the Belfort Universal Precipitation Gage 5-780 concurrent with a recorded response from the OTT PLUVIO Precipitation Gage.

  5. Hydrodynamics calculations for mini jade gages. Technical report

    SciTech Connect

    Schlaug, R.N.

    1983-07-29

    Two-dimensional hydrodynamics calculations were made with the STEALTH code to determine the response under 10 GPa loading of three designs of the SAI particle velocity gage. The calculations showed which design best measured the free field particle velocity. Two-dimensional calculations were also made for four designs of the SRI cylindrical stress gage. The calculations determined that the internal gage dynamics, particularly shock reflections, were primarily responsible for differences between the gage response and the free field stress. A material parameter study using a one-dimensional model was made to see if the use of other material combinations would improve the gage response. The internal dynamics of the flat pack stress gage were investigated using a one-dimensional model. The calculations indicated the severe early-time ringing seen in the gage response is caused by oscillatory motion of the iron plates.

  6. Airflow resistance of airflow-regulating devices described by independent coefficients.

    PubMed

    Verkerke, G J; Geertsema, A A; Schutte, H K

    2001-07-01

    Rehabilitation after laryngectomy includes more and more the use of airflow-regulating devices such as shunt valves (SVs), tracheostoma valves (TSVs), and heat and moisture exchange (HME) filters. In determining the quality of those devices, airflow resistance is a very important factor. It is currently defined as pressure drop divided by airflow. However, for most applications, this definition does not result in a pressure- and airflow-independent parameter. Therefore, a new set of parameters is defined and applied to pressure-airflow curves of airflow-regulating devices. Pressure drop over TSVs and HME filters appears to have a squared relationship with flow. In SVs, it has a linear relationship. The new set of parameters describes the pressure-airflow relationship properly for all considered devices. In conclusion, theoretical predictions of flow mechanics appear to be valid for SVs, TSVs, and HME filters. Only 2 coefficients are necessary to describe the pressure-flow characteristics of these airflow-regulating devices, independent of pressure drop over and flow through the device. PMID:11465823

  7. A photoelastic fiber optic strain gage

    NASA Technical Reports Server (NTRS)

    Su, Wei; Gilbert, John A.; Katsunis, Constantine

    1992-01-01

    This paper reports on the development of a photoelastic fiber optic strain gage sensitive to transverse strain. The sensing element is made from an epoxy resin which is stress frozen to passively achieve the quadrature condition. Light, emitted from an LED operating at 820 nm, is transmitted to and from the sensing element via multimode fibers and the signal is detected using a dual channel operational photodiode/amplifier. This unique combination of optics and electronics produces a fiber optic sensor having a high signal to noise ratio which is lead-in/out insensitive. Results show that strains on the order of 1 microstrain can be measured over an 800 microstrain range and that dummy gages can be used for temperature compensation.

  8. Investigation on side-spray fluidized bed granulation with swirling airflow.

    PubMed

    Wong, Poh Mun; Chan, Lai Wah; Heng, Paul Wan Sia

    2013-03-01

    Top-spray fluidized bed granulation with axial fluidization airflow from the bottom of the granulator is well-established in the pharmaceutical industry. The application of swirling airflow for fluidized bed granulation was more recently introduced. This study examined the effects of various process parameters on the granules produced by side-spray fluidized bed with swirling airflow using the central composite and Box-Behnken design of experiment. Influence of the amount of binder solution, spray rate, and distance between spray nozzle and powder bed were initially studied to establish operationally viable values for these parameters. This was followed by an in-depth investigation on the effects of inlet airflow rate, atomizing air pressure and distance between spray nozzle and powder bed on granule properties. It was found that the amount of binder solution had a positive correlation with granule size and percentage of lumps but a negative correlation with size distribution and Hausner ratio of the granules. Binder solution spray rate was also found to affect the granules size. High drug content uniformity was observed in all the batches of granules produced. Both inlet airflow rate and atomizing air pressure were found to correlate negatively with granule size and percentage of lumps but correlate positively with the size distribution of the granule produced. Percentage of fines was found to be significantly affected by inlet airflow rate. Distance between spray nozzle and powder bed generally affected the percentage of lumps. PMID:23263750

  9. Unidirectional pulmonary airflow in vertebrates: a review of structure, function, and evolution.

    PubMed

    Cieri, Robert L; Farmer, C G

    2016-07-01

    Mechanisms explaining unidirectional pulmonary airflow in birds, a condition where lung gases flow in a consistent direction during both inspiration and expiration in some parts of the lung, were suggested as early as the first part of the twentieth century and unidirectional pulmonary airflow has been discovered recently in crocodilians and squamates. Our knowledge of the functional anatomy, fluid dynamics, and significance of this trait is reviewed. The preponderance of the data indicates that unidirectional airflow is maintained by means of convective inertia in inspiratory and expiratory aerodynamic valves in birds. The study of flow patterns in non-avian reptiles is just beginning, but inspiratory aerodynamic valving likely also plays an important role in controlling flow direction in these lungs. Although highly efficient counter and cross-current blood-gas exchange arrangements are possible in lungs with unidirectional airflow, very few experiments have investigated blood-gas exchange mechanisms in the bird lung and blood-gas arrangements in the lungs of non-avian reptiles are completely unknown. The presence of unidirectional airflow in non-volant ectotherms voids the traditional hypothesis that this trait evolved to supply the high aerobic demands of flight and endothermy, and there is a need for new scenarios in our understanding of lung evolution. The potential value of unidirectional pulmonary airflow for allowing economic lung gas mixing, facilitating lung gas washout, and providing for adequate gas exchange during hypoxic conditions is discussed. PMID:27062030

  10. A Conversion of Wheatstone Bridge to Current-Loop Signal Conditioning for Strain Gages

    NASA Technical Reports Server (NTRS)

    Anderson, Karl F.

    1995-01-01

    Current loop circuitry replaced Wheatstone bridge circuitry to signal-condition strain gage transducers in more than 350 data channels for two different test programs at NASA Dryden Flight Research Center. The uncorrected test data from current loop circuitry had a lower noise level than data from comparable Wheatstone bridge circuitry, were linear with respect to gage-resistance change, and were uninfluenced by varying lead-wire resistance. The current loop channels were easier for the technicians to set up, verify, and operate than equivalent Wheatstone bridge channels. Design choices and circuit details are presented in this paper in addition to operational experience.

  11. Measurement of airflow in residential furnaces

    SciTech Connect

    Biermayer, Peter J.; Lutz, James; Lekov, Alex

    2004-01-24

    In order to have a standard for furnaces that includes electricity consumption or for the efficiency of furnace blowers to be determined, it is necessary to determine the airflow of a furnace or furnace blower. This study focused on airflow testing, in order to determine if an existing test method for measuring blower airflow could be used to measure the airflow of a furnace, under conditions seen in actual installations and to collect data and insights into the operating characteristics of various types of furnace blowers, to use in the analysis of the electricity consumption of furnaces. Results of the measured airflow on furnaces with three types of blower and motor combinations are presented in the report. These included: (1) a forward-curved blower wheel with a typical permanent split capacitor (PSC) motor, (2) a forward-curved blower wheel with an electronically-commutated motor (ECM), and (3) a prototype blower, consisting of a backward-inclined blower wheel matched to an ECM motor prototype, which is being developed as an energy-saving alternative to conventional furnace blowers. The testing provided data on power consumption, static and total pressure, and blower speed.

  12. An electromagnetic energy scavenger from direct airflow

    NASA Astrophysics Data System (ADS)

    Kim, Seong-Hyok; Ji, Chang-Hyeon; Galle, Preston; Herrault, Florian; Wu, Xiaosong; Lee, Jin-Ho; Choi, Chang-Auk; Allen, Mark G.

    2009-09-01

    This paper presents two types of electromagnetic power generators exploiting direct conversion of airflow into mechanical vibration: (1) a windbelt-based vibratory linear energy scavenger targeting strong airflows and (2) a Helmholtz-resonator-based generator capable of scavenging energy from weaker airflows, i.e. environmental airflows. Both devices consist of two tightly coupled parts: a mechanical resonator, which produces high-frequency mechanical oscillation from quasi-constant airflow, and a permanent magnet/coil system, which generates electrical power from the resonator's motion. The proposed energy scavengers obviate the typically required matching of the resonant frequencies of the scavenger and the ambient energy sources it taps. This enables a device that is simpler, smaller and higher-frequency than the previously reported resonant power generator. The windbelt-based energy scavenger demonstrated a peak-to-peak output voltage of 81 mV at 0.53 kHz, from an input pressure of 50 kPa. The Helmholtz-resonator-based energy scavenger achieved a peak-to-peak output voltage of 4 mV at 1.4 kHz, from an input pressure of 0.2 kPa, which is equivalent to 5 m s-1 (10 mph) of wind velocity.

  13. High-Temperature, Thin-Film Strain Gages Improved

    NASA Technical Reports Server (NTRS)

    2005-01-01

    Conventional resistance strain gage technology uses "bonded" strain gages. These foil or wire gages are bonded onto the surface of the test article with glue, ceramic cements, or flame-sprayed ceramics. These bonding agents can, in some instances, limit both the degree of strain transmission from the test structure to the gage and the maximum working temperature of the gage. Also, the bulky, bonded gage normally disrupts aerodynamic gas flow on the surface of the test structure because of its intrusive character. To respond to the urgent needs in aeronautic and aerospace research where stress and temperature gradients are high, aerodynamic effects need to be minimized, and higher operational temperatures are required, the NASA Lewis Research Center developed a thin film strain gage. This gage, a vacuum-deposited thin film formed directly on the surface of a test structure, operates at much higher temperatures than commercially available gages do and with minimal disruption of the aerodynamic flow. The gage uses an alloy, palladium-13 wt % chromium (hereafter, PdCr), which was developed by United Technologies Research Center under a NASA contract. PdCr is structurally stable and oxidation resistant up to at least 1100 C (2000 F); its temperature-induced resistance change is linear, repeatable, and not sensitive to the rates of heating and cooling. An early strain gage, which was made of 25-micrometer-diameter PdCr wire and demonstrated to be useable to 800 C, won an R&D 100 award in 1991. By further improving the purity of the material and by developing gage fabrication techniques that use sputter-deposition, photolithography patterning, and chemical etching, we have made an 8- to 10-m PdCr thin-film strain gage that can measure dynamic and static strain to at least 1100 C. For static strain measurements, a 5-m-thick Pt element serves as a temperature compensator to further minimize the temperature effect of the gage. These thin-film gages provide the advantage of

  14. Impulse gage development for the 100-200 ktap range

    SciTech Connect

    Rose, P.C.; Naumann, W.J. . Advanced Technologies Div.)

    1990-07-31

    Special effects underground test (UGT) material response and source diagnostics data require impulse gages that can be used in the 50--150 ktap range and have equilibrated from electrical and mechanical noise sources within 0.001 s. Such gages were designed, analyzed, and tested under this program. One- and two-dimensional stress propagation calculations were performed and predictions were developed for deformation of the gage specimen cup. These predictions were conservative when compared to gas gun test results. The response of the gage will equilibrate within 5% to its final value within 300 {mu}sec. The impulse delivered to the gages for these tests exceeded 250 ktap. The code and experimental results provides a basis for confidence in the operability of the gage in an actual UGT environment.

  15. AIRFLOW CHARACTERISTICS IN A BABOON NASAL PASSAGE CAST

    EPA Science Inventory

    Airflow patterns in the nasal Passages influence the distribution of air-pollutant-induced lesions in the airway mucosa. ittle is known about airflow characteristics or the complex nasopharyngeal airway of man and experimental animals. irflow characteristics in the nasopharyngeal...

  16. CFD modeling of pharmaceutical isolators with experimental verification of airflow.

    PubMed

    Nayan, N; Akay, H U; Walsh, M R; Bell, W V; Troyer, G L; Dukes, R E; Mohan, P

    2007-01-01

    Computational fluid dynamics (CFD) models have been developed to predict the airflow in a transfer isolator using a commercial CFD code. In order to assess the ability of the CFD approach in predicting the flow inside an isolator, hot wire anemometry measurements and a novel experimental flow visualization technique consisting of helium-filled glycerin bubbles were used. The results obtained have been shown to agree well with the experiments and show that CFD can be used to model barrier systems and isolators with practical fidelity. This indicates that CFD can and should be used to support the design, testing, and operation of barrier systems and isolators. PMID:17933207

  17. High temperature static strain gage development

    NASA Technical Reports Server (NTRS)

    Hulse, C. O.; Bailey, R. S.; Grant, H. P.; Anderson, W. L.; Przybyszewski, J. S.

    1991-01-01

    Final results are presented from a program to develop a thin film static strain gage for use on the blades and vanes of running, test stand gas turbine engines with goals of an 3 x 3 mm gage area and total errors of less than 10 pct. of + or - 2,000 microstrain after 50 hrs at 1250 K. Pd containing 13 Wt. pct. Cr was previously identified as a new strain sensor alloy that appeared to be potentially usable to 1250 K. Subsequently, it was discovered, in contrast with its behavior in bulk, that Pd-13Cr suffered from oxidation attack when prepared as a 4.5 micron thick thin film. Continuing problems with electrical leakage to the substrate and the inability of sputtered alumina overcoats to prevent oxidation led to the discovery that sputtered alumina contains appreciable amounts of entrapped argon. After the argon has been exsolved by heating to elevated temperatures, the alumina films undergo a linear shrinkage of about 2 pct. resulting in formation of cracks. These problems can be largely overcome by sputtering the alumina with the substrate heated to 870 K. With 2 micron thick hot sputtered alumina insulation and overcoat films, total 50 hr drifts of about 100 microstrain (2 tests) and about 500 microstrain (1 test) were observed at 1000 and 1100 K, respectively. Results of tests on complete strain gage systems on constant moment bend bars with Pd temperature compensation grids revealed that oxidation of the Pd grid was a major problem even when the grid was overcoated with a hot or cold sputtered alumina overcoat.

  18. Instrument Measures Airflow Friction Without Contact

    NASA Technical Reports Server (NTRS)

    Monson, D. J.

    1983-01-01

    Dual beam laser interferometer determines airflow friction against body by measuring time-varying thickness of wind sheared oil film. Measurements yield skin friction between film and airstream. Errors from prerun oil flow, tunnel starting transients, and initial surface waves therefore eliminated.

  19. Application of an On-machine Gage for Diameter Measurements

    NASA Technical Reports Server (NTRS)

    Harding, Kevin G.

    1993-01-01

    This paper describes the design analysis and application of a laser based gage made specifically for measuring parts on the machine tool to a high accuracy. The tri-beam gage uses three beams of light to measure the local curvature of the part in a manner similar to a V-block gage. The properties of this design include: calibration that is independent of the machine tool scales, non-contact damage free operation, low cost of the gage, and the ability to measure parts in motion.

  20. Buried wire gage for wall shear stress measurements

    NASA Technical Reports Server (NTRS)

    Murthy, V. S.; Rose, W. C.

    1978-01-01

    A buried wire gage for measuring wall shear stress in fluid flow was studied and further developed. Several methods of making this relatively new type of gage were examined to arrive at a successful technique that is well-suited for wind-tunnel testing. A series of measurements was made to demonstrate the adequacy of a two-point calibration procedure for these gages. The buried wire gage is also demonstrated to be ideally suited for quantitative measurement of wall shear stress in wind-tunnel testing.

  1. Strain Gage Selection Criteria for Textile Composite Materials

    NASA Technical Reports Server (NTRS)

    Masters, John E.

    1996-01-01

    This report will provide a review of efforts to establish a set of strain gage selection guidelines for textile reinforced composite materials. A variety of strain gages were evaluated in the study to determine the sensitivity of strain measurements to the size of the strain gage. The strain gages were chosen to provide a range of gage lengths and widths. The gage aspect ratio (the length-to-width ratio) was also varied. The gages were tested on a diverse collection of textile composite laminates. Test specimens featured eleven different textile architectures: four 2-D triaxial braids, six 3-D weaves, and one stitched uniweave architecture. All specimens were loaded in uniaxial tension. The materials' moduli were measured in both the longitudinal (parallel to the O deg. yarns) and the transverse (perpendicular to the O deg. yarns) directions. The results of these measurements were analyzed to establish performance levels for extensometers and strain gages on textile composite materials. Conclusions are expressed in a summary that discusses instrumentation practices and defines strain gage selection criteria.

  2. Particle velocity and stress gage measurements in spherical diverging flow

    SciTech Connect

    Larson, D.B.; Stout, R.B.

    1987-03-01

    Chemical explosions were used to generate spherically diverging stress waves in polymethylmethacrylate (PMMA). Piezoresistance gages of several different designs were placed in the PMMA radially from the spherical energy source. Two basic types of piezoresistance gages were used. One type was placed on backing material and then glued directly to the PMMA while the other type was placed on backing material and then enclosed in a fluid cavity which was attached to the PMMA. Gages were oriented normal to the direction of the shock front. In order to interpret the piezoresistance gage measurements and to obtain a complete set of data for numerical calculations, particle velocity was also measured at several radial positions from the explosion. In addition to different ytterbium gage designs, a triple material gage that contained ytterbium, manganin, and constant an foils was tested. This gage provided three independent resistivity history signals as output, one from each material. Results from an analysis of piezoresistance gage response in a multicomponent stress-strain field compared well with the experimental measurements for the triple material gage. 23 refs., 18 figs., 4 tabs.

  3. Airflow Measurement of the Car HVAC Unit Using Hot-wire Anemometry

    NASA Astrophysics Data System (ADS)

    Fojtlín, Miloš; Planka, Michal; Fišer, Jan; Pokorný, Jan; Jícha, Miroslav

    2016-03-01

    Thermal environment in a vehicular cabin significantly influence drivers' fatigue and passengers' thermal comfort. This environment is traditionally managed by HVAC cabin system that distributes air and modifies its properties. In order to simulate cabin thermal behaviour, amount of the air led through car vents must be determined. The aim of this study was to develop methodology to measure airflow from the vents, and consequently calculate corresponding air distribution coefficients. Three climatic cases were selected to match European winter, summer, and spring / fall conditions. Experiments were conducted on a test vehicle in a climatic chamber. The car HVAC system was set to automatic control mode, and the measurements were executed after the system stabilisation—each case was independently measured three times. To be able to evaluate precision of the method, the airflow was determined at the system inlet (HVAC suction) and outlet (each vent), and the total airflow values were compared. The airflow was calculated by determining a mean value of the air velocity multiplied by an area of inlet / outlet cross-section. Hot-wire anemometry was involved to measure the air velocity. Regarding the summer case, total airflow entering the cabin was around 57 l s-1 with 60 % of the air entering the cabin through dashboard vents; no air was supplied to the feet compartment. The remaining cases had the same total airflow of around 42 l s-1, and the air distribution was focused mainly on feet and windows. The inlet and outlet airflow values show a good match with a maximum mass differential of 8.3 %.

  4. Geoscience Workforce Development at UNAVCO: Leveraging the NSF GAGE Facility

    NASA Astrophysics Data System (ADS)

    Morris, A. R.; Charlevoix, D. J.; Miller, M.

    2013-12-01

    Global economic development demands that the United States remain competitive in the STEM fields, and developing a forward-looking and well-trained geoscience workforce is imperative. According to the Bureau of Labor Statistics, the geosciences will experience a growth of 19% by 2016. Fifty percent of the current geoscience workforce is within 10-15 years of retirement, and as a result, the U.S. is facing a gap between the supply of prepared geoscientists and the demand for well-trained labor. Barring aggressive intervention, the imbalance in the geoscience workforce will continue to grow, leaving the increased demand unmet. UNAVCO, Inc. is well situated to prepare undergraduate students for placement in geoscience technical positions and advanced graduate study. UNAVCO is a university-governed consortium facilitating research and education in the geosciences and in addition UNAVCO manages the NSF Geodesy Advancing Geosciences and EarthScope (GAGE) facility. The GAGE facility supports many facets of geoscience research including instrumentation and infrastructure, data analysis, cyberinfrastructure, and broader impacts. UNAVCO supports the Research Experiences in the Solid Earth Sciences for Students (RESESS), an NSF-funded multiyear geoscience research internship, community support, and professional development program. The primary goal of the RESESS program is to increase the number of historically underrepresented students entering graduate school in the geosciences. RESESS has met with high success in the first 9 years of the program, as more than 75% of RESESS alumni are currently in Master's and PhD programs across the U.S. Building upon the successes of RESESS, UNAVCO is launching a comprehensive workforce development program that will network underrepresented groups in the geosciences to research and opportunities throughout the geosciences. This presentation will focus on the successes of the RESESS program and plans to expand on this success with broader

  5. 46 CFR 197.318 - Gages and timekeeping devices.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Gages and timekeeping devices. 197.318 Section 197.318 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE OCCUPATIONAL SAFETY AND HEALTH STANDARDS GENERAL PROVISIONS Commercial Diving Operations Equipment § 197.318 Gages and timekeeping...

  6. 46 CFR 197.318 - Gages and timekeeping devices.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Gages and timekeeping devices. 197.318 Section 197.318 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE OCCUPATIONAL SAFETY AND HEALTH STANDARDS GENERAL PROVISIONS Commercial Diving Operations Equipment § 197.318 Gages and timekeeping...

  7. 16 CFR Figure 2 to Part 1511 - Small Parts Gage

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 16 Commercial Practices 2 2013-01-01 2013-01-01 false Small Parts Gage 2 Figure 2 to Part 1511 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS SUBSTANCES ACT REGULATIONS REQUIREMENTS FOR PACIFIERS Pt.1511, Fig. 2 Figure 2 to Part 1511—Small Parts Gage EC03OC91.069...

  8. 16 CFR Figure 2 to Part 1511 - Small Parts Gage

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 16 Commercial Practices 2 2012-01-01 2012-01-01 false Small Parts Gage 2 Figure 2 to Part 1511 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS SUBSTANCES ACT REGULATIONS REQUIREMENTS FOR PACIFIERS Pt.1511, Fig. 2 Figure 2 to Part 1511—Small Parts Gage EC03OC91.069...

  9. 16 CFR Figure 2 to Part 1511 - Small Parts Gage

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 16 Commercial Practices 2 2014-01-01 2014-01-01 false Small Parts Gage 2 Figure 2 to Part 1511 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS SUBSTANCES ACT REGULATIONS REQUIREMENTS FOR PACIFIERS Pt.1511, Fig. 2 Figure 2 to Part 1511—Small Parts Gage EC03OC91.069...

  10. 16 CFR Figure 2 to Part 1511 - Small Parts Gage

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 16 Commercial Practices 2 2011-01-01 2011-01-01 false Small Parts Gage 2 Figure 2 to Part 1511 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS SUBSTANCES ACT REGULATIONS REQUIREMENTS FOR PACIFIERS Pt.1511, Fig. 2 Figure 2 to Part 1511—Small Parts Gage EC03OC91.069...

  11. 16 CFR Figure 2 to Part 1511 - Small Parts Gage

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Small Parts Gage 2 Figure 2 to Part 1511 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS SUBSTANCES ACT REGULATIONS REQUIREMENTS FOR PACIFIERS Pt.1511, Fig. 2 Figure 2 to Part 1511—Small Parts Gage EC03OC91.069...

  12. 14. VIEW OF GAGE IRRIGATION CANAL AT HILLTOP DRIVE AND ...

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

    14. VIEW OF GAGE IRRIGATION CANAL AT HILLTOP DRIVE AND BARTON ROAD, SHOWING OLD ROUTE OF CANAL VIADUCT ACROSS BARTON ROAD. SIPHON NOW GOES UNDER ROAD AND EMERGES AT RIGHT REAR BELOW TWO TELEPHONE POLES (SEE CA-120-15) - Gage Irrigation Canal, Running from Santa Ana River to Arlington Heights, Riverside, Riverside County, CA

  13. Rod and dish cathode improves penning-type vacuum gage

    NASA Technical Reports Server (NTRS)

    Peppin, G. B.

    1966-01-01

    Improved penning-type ionization gage provides range and sensitivity required to measure gas pressure below .01 torr under high vacuum conditions. The gage uses a highly conductive cathode composed of two disks of high magnetic permeability separated by a rod of low magnetic permeability.

  14. 46 CFR 197.318 - Gages and timekeeping devices.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Gages and timekeeping devices. 197.318 Section 197.318 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE OCCUPATIONAL SAFETY AND HEALTH STANDARDS GENERAL PROVISIONS Commercial Diving Operations Equipment § 197.318 Gages and timekeeping...

  15. 46 CFR 197.318 - Gages and timekeeping devices.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Gages and timekeeping devices. 197.318 Section 197.318 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE OCCUPATIONAL SAFETY AND HEALTH STANDARDS GENERAL PROVISIONS Commercial Diving Operations Equipment § 197.318 Gages and timekeeping...

  16. 46 CFR 197.318 - Gages and timekeeping devices.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Gages and timekeeping devices. 197.318 Section 197.318 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE OCCUPATIONAL SAFETY AND HEALTH STANDARDS GENERAL PROVISIONS Commercial Diving Operations Equipment § 197.318 Gages and timekeeping...

  17. Cold cathode ionization gage has rigid metal housing

    NASA Technical Reports Server (NTRS)

    Herzog, R.; Kreisman, W. S.

    1966-01-01

    Cold cathode ionization gage in a stainless steel housing accurately measures high pressures. The penning effect is used with a high voltage discharge in the presence of a magnetic field for an ion current proportional to the gas pressure in the gage.

  18. Gage monitors quality of cross-wire resistance welds

    NASA Technical Reports Server (NTRS)

    Etzel, J.; Piltch, A.

    1968-01-01

    Gage nondestructively monitors the quality of cross-wire resistance welds during the welding operation. The gage gives a dial indication of the relative embedment of the cross wires during the actual welding operation. A direct relationship exists between the depth of embedment and both weld strength and consistency.

  19. 49 CFR 213.110 - Gage restraint measurement systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Gage restraint measurement systems. 213.110... measurement systems. (a) A track owner may elect to implement a Gage Restraint Measurement System (GRMS... correlation between measurements made on the ground and those recorded by the instrumentation with respect...

  20. 49 CFR 213.110 - Gage restraint measurement systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Gage restraint measurement systems. 213.110... measurement systems. (a) A track owner may elect to implement a Gage Restraint Measurement System (GRMS... correlation between measurements made on the ground and those recorded by the instrumentation with respect...

  1. 25. Photocopy of photograph (original print at Gage Canal Company ...

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

    25. Photocopy of photograph (original print at Gage Canal Company Office), photographer unknown, March 1954. VIEW OF THE GAGE IRRIGATION CANAL, CONCRETE 'COVERING COMPLETED & BACKFILLED TO WATERMAN AVENUE...CURVING TOWARD NO. 1 TUNNEL' - California Citrus Heritage Recording Project, Riverside, Riverside County, CA

  2. 21. Photocopy of photograph (original print at Gage Canal Company ...

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

    21. Photocopy of photograph (original print at Gage Canal Company Office), H. B. Wesner, photographer, date unknown. 'VIEWS OF SOUTHERN CALIFORNIA SCENERY. ARTESIAN WELLS, SAN BERNARDINO, CALIFORNIA. SUPPLYING THE GAGE CANAL OF RIVERSIDE.' - California Citrus Heritage Recording Project, Riverside, Riverside County, CA

  3. Thin-film gage measures low heat-transfer rates

    NASA Technical Reports Server (NTRS)

    Spitzer, C. R.

    1966-01-01

    Low heat-transfer gage facilitates determination of the transition between laminar and turbulent conditions, in the boundary layer surrounding slender and moderately slender cones under test in a hypersonic blowdown helium tunnel. The gage consists of a thin layer of vacuum-evaporated platinum on a heat resistant glass substrate contoured to fit model surfaces.

  4. Automating the Solar DRYER—AIRFLOW Control Utilizing Pressure Diffrence Concept

    NASA Astrophysics Data System (ADS)

    Luk, T. B.; Vakhguelt, A.

    2009-08-01

    The presence of a chimney in natural convective solar dryer has proven its benefit in accelerated transport of moist air from the drying compartment and thus shortening the drying time for intended crops. The experiment and simulation studies done by various parties have guaranteed increases in the airflow in relation to the physical height of chimney. A simple automated control system is proposed to assist the controls of airflow rate so that a near optimum mass flow rate could be achieved for the best possible dried product quality in the shortest possible drying period.

  5. Dual strain gage balance system for measuring light loads

    NASA Technical Reports Server (NTRS)

    Roberts, Paul W. (Inventor)

    1991-01-01

    A dual strain gage balance system for measuring normal and axial forces and pitching moment of a metric airfoil model imparted by aerodynamic loads applied to the airfoil model during wind tunnel testing includes a pair of non-metric panels being rigidly connected to and extending towards each other from opposite sides of the wind tunnel, and a pair of strain gage balances, each connected to one of the non-metric panels and to one of the opposite ends of the metric airfoil model for mounting the metric airfoil model between the pair of non-metric panels. Each strain gage balance has a first measuring section for mounting a first strain gage bridge for measuring normal force and pitching moment and a second measuring section for mounting a second strain gage bridge for measuring axial force.

  6. Heat-Flux Gage thermophosphor system

    SciTech Connect

    Tobin, K.W.

    1991-08-01

    This document describes the installation, hardware requirements, and application of the Heat-Flux Gage (Version 1.0) software package developed by the Oak Ridge National Laboratory, Applied Technology Division. The developed software is a single component of a thermographic phosphor-based temperature and heat-flux measurement system. The heat-flux transducer was developed by EG G Energy Measurements Systems and consists of a 1- by 1-in. polymethylpentene sheet coated on the front and back with a repeating thermographic phosphor pattern. The phosphor chosen for this application is gadolinium oxysulphide doped with terbium. This compound has a sensitive temperature response from 10 to 65.6{degree}C (50--150{degree}F) for the 415- and 490-nm spectral emission lines. 3 refs., 17 figs.

  7. Hybrid mesh for nasal airflow studies.

    PubMed

    Zubair, Mohammed; Abdullah, Mohammed Zulkifly; Ahmad, Kamarul Arifin

    2013-01-01

    The accuracy of the numerical result is closely related to mesh density as well as its distribution. Mesh plays a very significant role in the outcome of numerical simulation. Many nasal airflow studies have employed unstructured mesh and more recently hybrid mesh scheme has been utilized considering the complexity of anatomical architecture. The objective of this study is to compare the results of hybrid mesh with unstructured mesh and study its effect on the flow parameters inside the nasal cavity. A three-dimensional nasal cavity model is reconstructed based on computed tomographic images of a healthy Malaysian adult nose. Navier-Stokes equation for steady airflow is solved numerically to examine inspiratory nasal flow. The pressure drop obtained using the unstructured computational grid is about 22.6 Pa for a flow rate of 20 L/min, whereas the hybrid mesh resulted in 17.8 Pa for the same flow rate. The maximum velocity obtained at the nasal valve using unstructured grid is 4.18 m/s and that with hybrid mesh is around 4.76 m/s. Hybrid mesh reported lower grid convergence index (GCI) than the unstructured mesh. Significant differences between unstructured mesh and hybrid mesh are determined highlighting the usefulness of hybrid mesh for nasal airflow studies. PMID:23983811

  8. Hybrid Mesh for Nasal Airflow Studies

    PubMed Central

    Zubair, Mohammed; Abdullah, Mohammed Zulkifly; Ahmad, Kamarul Arifin

    2013-01-01

    The accuracy of the numerical result is closely related to mesh density as well as its distribution. Mesh plays a very significant role in the outcome of numerical simulation. Many nasal airflow studies have employed unstructured mesh and more recently hybrid mesh scheme has been utilized considering the complexity of anatomical architecture. The objective of this study is to compare the results of hybrid mesh with unstructured mesh and study its effect on the flow parameters inside the nasal cavity. A three-dimensional nasal cavity model is reconstructed based on computed tomographic images of a healthy Malaysian adult nose. Navier-Stokes equation for steady airflow is solved numerically to examine inspiratory nasal flow. The pressure drop obtained using the unstructured computational grid is about 22.6 Pa for a flow rate of 20 L/min, whereas the hybrid mesh resulted in 17.8 Pa for the same flow rate. The maximum velocity obtained at the nasal valve using unstructured grid is 4.18 m/s and that with hybrid mesh is around 4.76 m/s. Hybrid mesh reported lower grid convergence index (GCI) than the unstructured mesh. Significant differences between unstructured mesh and hybrid mesh are determined highlighting the usefulness of hybrid mesh for nasal airflow studies. PMID:23983811

  9. Cost effectiveness of the stream-gaging program in Ohio

    USGS Publications Warehouse

    Shindel, H.L.; Bartlett, W.P.

    1986-01-01

    This report documents the results of the cost effectiveness of the stream-gaging program in Ohio. Data uses and funding sources were identified for 107 continuous stream gages currently being operated by the U.S. Geological Survey in Ohio with a budget of $682,000; this budget includes field work for other projects and excludes stations jointly operated with the Miami Conservancy District. No stream gage were identified as having insufficient reason to continue their operation; nor were any station identified as having uses specifically only for short-term studies. All 107 station should be maintained in the program for the foreseeable future. The average standard error of estimation of stream flow records is 29.2 percent at its present level of funding. A minimum budget of $679,000 is required to operate the 107-gage program; a budget less than this does no permit proper service and maintenance of the gages and recorders. At the minimum budget, the average standard error is 31.1 percent The maximum budget analyzed was $1,282,000, which resulted in an average standard error of 11.1 percent. A need for additional gages has been identified by the other agencies that cooperate in the program. It is suggested that these gage be installed as funds can be made available.

  10. Cost effectiveness of the stream-gaging program in Louisiana

    USGS Publications Warehouse

    Herbert, R.A.; Carlson, D.D.

    1985-01-01

    This report documents the results of a study of the cost effectiveness of the stream-gaging program in Louisiana. Data uses and funding sources were identified for the 68 continuous-record stream gages currently (1984) in operation with a budget of $408,700. Three stream gages have uses specific to a short-term study with no need for continued data collection beyond the study. The remaining 65 stations should be maintained in the program for the foreseeable future. In addition to the current operation of continuous-record stations, a number of wells, flood-profile gages, crest-stage gages, and stage stations, are serviced on the continuous-record station routes; thus, increasing the current budget to $423,000. The average standard error of estimate for data collected at the stations is 34.6%. Standard errors computed in this study are one measure of streamflow errors, and can be used as guidelines in comparing the effectiveness of alternative networks. By using the routes and number of measurements prescribed by the ' Traveling Hydrographer Program, ' the standard error could be reduced to 31.5% with the current budget of $423,000. If the gaging resources are redistributed, the 34.6% overall level of accuracy at the 68 continuous-record sites and the servicing of the additional wells or gages could be maintained with a budget of approximately $410,000. (USGS)

  11. Effect of airflow on biodrying of gardening wastes in reactors.

    PubMed

    Colomer-Mendoza, F J; Herrera-Prats, L; Robles-Martínez, F; Gallardo-Izquierdo, A; Piña-Guzmán, A B

    2013-05-01

    Biodrying consists of reducing moisture by using the heat from aerobic bio-degradation. The parameters that control the process are: aeration, temperature during the process, initial moisture of biowaste, and temperature and relative humidity of the input air. Lawn mowing and garden waste from the gardens of the University Jaume I, Castellón (Spain) were used as a substrate. Biodrying was performed in 10 reactors with known air volumes from 0.88 to 6.42 L/(min x kg dry weight). To promote aeration, 5 of the reactors had 15% of a bulking agent added. The experiment lasted 20 days. After the experiments it was found that the bulking agent led to greater weight loss. However, the increased airflow rate was not linearly proportional to the weight loss. PMID:24218815

  12. High temperature strain measurement with a resistance strain gage

    NASA Technical Reports Server (NTRS)

    Lei, Jih-Fen; Fichtel, ED; Mcdaniel, Amos

    1993-01-01

    A PdCr based electrical resistance strain gage was demonstrated in the laboratory to be a viable sensor candidate for static strain measurement at high temperatures. However, difficulties were encountered while transferring the sensor to field applications. This paper is therefore prepared for recognition and resolution of the problems likely to be encountered with PdCr strain gages in field applications. Errors caused by the measurement system, installation technique and lead wire attachment are discussed. The limitations and some considerations related to the temperature compensation technique used for this gage are also addressed.

  13. Theory and Practice of Shear/Stress Strain Gage Hygrometry

    NASA Technical Reports Server (NTRS)

    Shams, Qamar A.; Fenner, Ralph L.

    2006-01-01

    Mechanical hygrometry has progressed during the last several decades from crude hygroscopes to state-of-the art strain-gage sensors. The strain-gage devices vary from different metallic beams to strain-gage sensors using cellulose crystallite elements, held in full shear restraint. This old technique is still in use but several companies are now actively pursuing development of MEMS miniaturized humidity sensors. These new sensors use polyimide thin film for water vapor adsorption and desorption. This paper will provide overview about modern humidity sensors.

  14. Triple-material stress-strain resistivity gage

    DOEpatents

    Stout, R.B.

    1988-05-17

    A triple material piezoresistive gage provides multi-component elastic stress measurements is disclosed. Thin foils of three piezoresistive materials, e.g. ytterbium, manganin, and constantan, are configured in a nested serpentine rectilinear grid or other grid arrangement and embedded in a medium, preferably normal to the direction of shock wave propagation. The output of the gage is a resistivity change history for each material of the gage. Each resistivity change is independent of the others so that three diagonal components of the elastic stress or strain tensor can be calculated from the resistivity measurements. 4 figs.

  15. Triple-material stress-strain resistivity gage

    DOEpatents

    Stout, R.B.

    1987-05-19

    A triple material piezoresistive gage provides multi-component elastic stress or strain measurements. Thin foils of three piezoresistive materials, e.g., ytterbium, manganin, and constantan, are configured in a nested serpentine rectilinear grind or other grind arrangement and embedded in a medium, preferably normal to the direction of shock wave propagation. The output of the gage is a resistivity change history for each material of gage. Each resistivity change is independent of the others so that three diagonal components of the elastic stress or strain tensor can be calculated form the resistivity measurements. 4 figs.

  16. Triple-material stress-strain resistivity gage

    DOEpatents

    Stout, Ray B.

    1988-01-01

    A triple material piezoresistive gage provides multi-component elastic stress or measurements. Thin foils of three piezoresistive materials, e.g. ytterbium, manganin, and constantan, are configured in a nested serpentine rectilinear grid or other grid arrangement and embedded in a medium, preferably normal to the direction of shock wave propagation. The output of the gage is a resistivity change history for each material of the gage. Each resistivity change is independent of the others so that three diagonal components of the elastic stress or strain tensor can be calculated from the resistivity measurements.

  17. Considerations for efficient airflow design in cleanrooms

    SciTech Connect

    Xu, Tengfang

    2004-07-29

    A high-performance cleanroom should provide efficient energy performance in addition to effective contamination control. Energy-efficient designs can yield capital and operational cost savings, and can be part of a strategy to improve productivity in the cleanroom industry. Based upon in-situ measurement data from ISO Class 5 clean rooms, this article discusses key factors affecting cleanroom air system performance and benefits of efficient airflow design in clean rooms. Cleanroom HVAC systems used in the semiconductor, pharmaceutical, and healthcare industries are very energy intensive, requiring large volumes of cleaned air to remove or dilute contaminants for satisfactory operations. There is a tendency, however, to design excessive airflow rates into cleanroom HVAC systems, due to factors such as design conservatism, lack of thorough understanding of airflow requirements, concerns about cleanliness reliability, and potential design and operational liabilities. Energy use of cleanroom environmental systems varies with system type and design, cleanroom functions, and the control of critical parameters such as temperature and humidity. In particular, cleanroom cleanliness requirements specified by cleanliness class have an impact on overall energy use. A previous study covering Europe and the US reveals annual cleanroom electricity usage for cooling and fan energy varies significantly depending on cleanliness class, and may account for up to three-quarters of total annual operating costs. A study on a semiconductor cleanroom in Japan found air delivery systems account for more than 30% of total power consumption. It is evident that the main factors dictating cleanroom operation energy include airflow rates and HVAC system efficiency. Improving energy efficiency in clean rooms may potentially contribute to significant savings in the initial costs of the facilities as well as operation and maintenance costs. For example, energy consumption by a typical chip

  18. Uninstrumented assembly airflow testing in the Annular Flow Distribution facility

    SciTech Connect

    Kielpinski, A.L.

    1992-02-01

    During the Emergency Cooling System phase of a postulated large-break loss of coolant accident (ECS-LOCA), air enters the primary loop and is pumped down the reactor assemblies. One of the experiments performed to support the analysis of this accident was the Annular Flow Distribution (AFD) experiment, conducted in a facility built for this purpose at Babcock and Wilcox Alliance Research Center in Alliance, Ohio. As part of this experiment, a large body of airflow data were acquired in a prototypical mockup of the Mark 22 reactor assembly. This assembly was known as the AFD (or the I-AFD here) reference assembly. The I-AFD assembly was fully prototypical, having been manufactured in SRS`s production fabrication facility. Similar Mark 22 mockup assemblies were tested in several test facilities in the SRS Heat Transfer Laboratory (HTL). Discrepancies were found. The present report documents further work done to address the discrepancy in airflow measurements between the AFD facility and HTL facilities. The primary purpose of this report is to disseminate the data from the U-AFD test, and to compare these test results to the I-AFD data and the U-AT data. A summary table of the test data and the B&W data transmittal letter are included as an attachment to this report. The full data transmittal volume from B&W (including time plots of the various instruments) is included as an appendix to this report. These data are further analyzed by comparing them to two other HTL tests, namely, SPRIHTE 1 and the Single Assembly Test Stand (SATS).

  19. Airflow limitation is accompanied by diaphragm dysfunction.

    PubMed

    Hellebrandová, L; Chlumský, J; Vostatek, P; Novák, D; Rýznarová, Z; Bunc, V

    2016-07-18

    Chronic airflow limitation, caused by chronic obstructive pulmonary disease (COPD) or by asthma, is believed to change the shape and the position of the diaphragm due to an increase in lung volume. We have made a comparison of magnetic resonance imaging (MRI) of diaphragm in supine position with pulmonary functions, respiratory muscle function and exercise tolerance. We have studied the differences between patients with COPD, patients with asthma, and healthy subjects. Most interestingly we found the lung hyperinflation leads to the changes in diaphragmatic excursions during the breathing cycle, seen in the differences between the maximal expiratory diaphragm position (DPex) in patients with COPD and control group (p=0.0016). The magnitude of the diaphragmatic dysfunction was significantly related to the airflow limitation expressed by the ratio of forced expiratory volume in 1 s to slow vital capacity (FEV(1)/SVC), (%, p=0.0007); to the lung hyperinflation expressed as the ratio of the residual volume to total lung capacity (RV/TLC), (%, p=0.0018) and the extent of tidal volume constrain expressed as maximal tidal volume (V(Tmax)), ([l], p=0.0002); and the ratio of tidal volume to slow vital capacity (V(T)/SVC), (p=0.0038) during submaximal exercise. These results suggest that diaphragmatic movement fails to contribute sufficiently to the change in lung volume in emphysema. Tests of respiratory muscle function were related to the position of the diaphragm in deep expiration, e.g. neuromuscular coupling (P(0.1)/V(T)) (p=0.0232). The results have shown that the lung volumes determine the position of the diaphragm and function of the respiratory muscles. Chronic airflow limitation seems to change the position of the diaphragm, which thereafter influences inspiratory muscle function and exercise tolerance. There is an apparent relationship between the position of the diaphragm and the pulmonary functions and exercise tolerance. PMID:27070746

  20. Incidence of airflow limitation among employees in Norwegian smelters.

    PubMed

    Søyseth, Vidar; Johnsen, Helle Laier; Bugge, Merete Drevvatne; Hetland, Siri Merete; Kongerud, Johny

    2011-09-01

    We have investigated the association between the incidence of airflow limitation and occupational exposure. The employees (n = 3,924) were investigated annually during five years (n = 16,570) using spirometry. Exposure was classified using job category and a job exposure matrix. Airflow limitation was expressed using two indices: (i) as forced expiratory volume in one second/force vital capacity (FEV(1) /FVC) <0.7 and (ii) lower limit of normal (LLN). The incidence of airflow limitation was 21.2/1000 years(-1) and 15.1/1000 years(-1) using the fixed limit (0.7) and the LLN criterion, respectively. We found a dose-response relationship between the incidence of airflow limitation and tobacco consumption and with job-category in non-smokers. The associations between airflow limitation and covariates were independent of how airflow limitation was defined. The incidence of airflow limitation defined as FEV(l) /FVC <0.7 yielded higher incidence rates of airflow limitation than LLN. We found a significant association between the incidence of airflow limitation and occupational exposure in non-smokers. PMID:21360726

  1. Speckle reduction methods for laser line gages

    NASA Astrophysics Data System (ADS)

    Harding, Kevin G.

    1997-12-01

    Speckle caused by the use of laser sources is a well known phenomena. For some applications, the presence of the speckle is used as part of the method, but in others it is purely a source of noise. In the case of line based laser gages, speckle is typically of considerable concern. Certainly, using white light sources or LEDs with short coherence is one way around this problem, but such methods also loose some of the valuable properties of laser line projection such as very narrow lines, the ability to create multiple lines by diffraction, and high signal to background through the use of bandpass filters to view only the laser wavelength. There have been a number of valuable tools introduced that help reduce the problem of speckle from laser sources, without giving up all the advantages of the laser itself. This paper reviews the pros and cons of a number of these methods, and suggests a specific set of tools that are specific to laser line projection.

  2. Gage for measuring displacements in rock samples

    DOEpatents

    Holcomb, David J.; McNamee, Michael J.

    1986-01-01

    A gage for measuring diametral displacement within a rock sample for use in a rock mechanics laboratory and in the field, comprises a support ring housing a linear variable differential transformer, a mounting screw, and a leaf spring. The mounting screw is adjustable and defines a first point of contact with the rock sample. The leaf spring has opposite ends fixed to the inner periphery of the mounting ring. An intermediate portion of the leaf spring projecting radially inward from the ring is formed with a dimple defining a second point of contact with the sample. The first and second points of contact are diametrically opposed to each other. The LVDT is mounted in the ring with its axis parallel to the line of measurement and its core rod received in the dimple of the leaf spring. Any change in the length of the line between the first and second support points is directly communicated to the LVDT. The leaf spring is rigid to completely support lateral forces so that the LVDT is free of all load for improved precision.

  3. Gage for measuring displacements in rock samples

    DOEpatents

    Holcomb, D.J.; McNamee, M.J.

    1985-07-18

    A gage for measuring diametral displacement within a rock sample for use in a rock mechanics laboratory and in the field, comprises a support ring housing a linear variable differential transformer (LVDT), a mounting screw, and a leaf spring. The mounting screw is adjustable and defines a first point of contact with the rock sample. The leaf spring has opposite ends fixed to the inner periphery of the mounting ring. An intermediate portion of the leaf spring projecting radially inward from the ring is formed with a dimple defining a second point of contact with the sample. The first and second points of contact are diametrically opposed to each other. The LVDT is mounted in the ring with its axis parallel to the line of measurement and its core rod received in the dimple of the leaf spring. Any change in the length of the line between the first and second support points is directly communicated to the LVDT. The leaf spring is rigid to completely support lateral forces so that the LVDT is free of all load for improved precision.

  4. 49 CFR 213.110 - Gage restraint measurement systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION TRACK SAFETY STANDARDS Track Structure § 213.110 Gage restraint... test will not be considered valid until contact with these components is restored under static...

  5. 49 CFR 213.110 - Gage restraint measurement systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION TRACK SAFETY STANDARDS Track Structure § 213.110 Gage restraint... test will not be considered valid until contact with these components is restored under static...

  6. 26. Mechanical float gages used to monitor level of water ...

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

    26. Mechanical float gages used to monitor level of water in the filtration bed reservoir. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  7. Reliability study of the NiH2 strain gage

    NASA Technical Reports Server (NTRS)

    Klein, Glenn C.; Rash, Donald E., Jr.

    1993-01-01

    This paper summarizes a joint study by Gates Aerospace Batteries (GAB) and the Reliability Analysis Center (RAC). This study characterizes the reliability and robustness of the temperature compensated strain gages currently specified for sensing of internal pressure of NiH2 cells. These strain gages are characterized as fully encapsulated, metallic foil grids with known resistance that varies with deformation. The measurable deformation, when typically installed on the hemispherical portion of a NiH2 cell, is proportional to the material stresses as generated by internal cell pressures. The internal pressure sensed in this manner is calibrated to indicate the state-of-charge for the cell. This study analyzes and assesses both robustness and reliability for the basic design of the strain gage, the installation of the strain gage, and the circuitry involved.

  8. 49. View of unlined canal near inline stream gaging station, ...

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

    49. View of unlined canal near in-line stream gaging station, looking west. Photo by Robin Lee Tedder, Puget Power, 1989. - Puget Sound Power & Light Company, White River Hydroelectric Project, 600 North River Avenue, Dieringer, Pierce County, WA

  9. 50. Stream gaging station in steelpipe well and shelter, looking ...

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

    50. Stream gaging station in steel-pipe well and shelter, looking west. Photo by Robin Lee Tedder, Puget Power, 1989. - Puget Sound Power & Light Company, White River Hydroelectric Project, 600 North River Avenue, Dieringer, Pierce County, WA

  10. NASA LaRC Strain Gage Balance Design Concepts

    NASA Technical Reports Server (NTRS)

    Rhew, Ray D.

    1999-01-01

    The NASA Langley Research Center (LaRC) has been designing strain-gage balances for more than fifty years. These balances have been utilized in Langley's wind tunnels, which span over a wide variety of aerodynamic test regimes, as well as other ground based test facilities and in space flight applications. As a result, the designs encompass a large array of sizes, loads, and environmental effects. Currently Langley has more than 300 balances available for its researchers. This paper will focus on the design concepts for internal sting mounted strain-gage balances. However, these techniques can be applied to all force measurement design applications. Strain-gage balance concepts that have been developed over the years including material selection, sting, model interfaces, measuring, sections, fabrication, strain-gaging and calibration will be discussed.

  11. 49 CFR 213.355 - Frog guard rails and guard faces; gage.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Frog guard rails and guard faces; gage. 213.355... Higher § 213.355 Frog guard rails and guard faces; gage. The guard check and guard face gages in frogs... distance between the gage line of a frog to the guard line 1 of its guard rail or guarding face,...

  12. 49 CFR 213.355 - Frog guard rails and guard faces; gage.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Frog guard rails and guard faces; gage. 213.355... Higher § 213.355 Frog guard rails and guard faces; gage. The guard check and guard face gages in frogs... distance between the gage line of a frog to the guard line 1 of its guard rail or guarding face,...

  13. 49 CFR 213.355 - Frog guard rails and guard faces; gage.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Frog guard rails and guard faces; gage. 213.355... Higher § 213.355 Frog guard rails and guard faces; gage. The guard check and guard face gages in frogs... distance between the gage line of a frog to the guard line 1 of its guard rail or guarding face,...

  14. 49 CFR 213.355 - Frog guard rails and guard faces; gage.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Frog guard rails and guard faces; gage. 213.355... Higher § 213.355 Frog guard rails and guard faces; gage. The guard check and guard face gages in frogs... distance between the gage line of a frog to the guard line 1 of its guard rail or guarding face,...

  15. 49 CFR 213.355 - Frog guard rails and guard faces; gage.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Frog guard rails and guard faces; gage. 213.355... Higher § 213.355 Frog guard rails and guard faces; gage. The guard check and guard face gages in frogs... distance between the gage line of a frog to the guard line 1 of its guard rail or guarding face,...

  16. Fiber Optic Strain Gage Installation at the DUSEL Site

    NASA Astrophysics Data System (ADS)

    Maclaughlin, M.; Noni, N.; Turner, A.; Gage, J.; Wang, H. F.

    2009-12-01

    Collaborators at Montana Tech and the University of Wisconsin-Madison plan to use fiber optic strain gages to monitor rock deformation at the Deep Underground Science and Engineering Laboratory (DUSEL) site in Lead, SD. This new fiber optic technology, accurate to 1-microstrain, has been used in engineering applications, but this is the first installation in hard rock underground. The goal is to study the performance of the new technology and make use of the resulting rock deformation data. Distributed and local strain measurements will inform the design and construction of large caverns and contribute knowledge to several geomechanics, hydrology, and geoengineering studies at DUSEL. Installations are planned for the 4100 and 4850 levels. The first installation, in July 2009, is on the 4100 level in the Precambrian Poorman formation. In the installation area, the Poorman formation consists of a strongly foliated and lineated mica schist with garnet porphyroblasts and disseminated pyrrhotite along bedding planes. Quartz veins oblique to foliation are boudinaged. The area also includes several joint sets oblique to the foliation and our sensors. The gages installed in July 2009 are six Micron Optics os3600 temperature-compensated strain gages, 1-m long. The photo shows a triplet, a sensor array of three mutually perpendicular sensors. Each triplet has two surface mounted gages and one embedded gage. Mounting brackets for the surface gages are welded to the heads of 5-ft deep DYWIDAG rock bolts. The embedded gages are grouted into 5-ft deep reamed holes drilled 10 degrees downdip. A portable laser interrogator, Micron Optics si325, collected data during installation confirming the operation of each gage. An industrial laser & computer in an environmental box, Micron Optics sm130 controlled by an sp130, will be installed in October 2009. It will be connected to the 4100 level AC power and Ethernet and will continuously record data. The online data will be controlled

  17. Airflow elicits a spider's jump towards airborne prey. I. Airflow around a flying blowfly

    PubMed Central

    Klopsch, Christian; Kuhlmann, Hendrik C.; Barth, Friedrich G.

    2012-01-01

    The hunting spider Cupiennius salei uses airflow generated by flying insects for the guidance of its prey-capture jump. We investigated the velocity field of the airflow generated by a freely flying blowfly close to the flow sensors on the spider's legs. It shows three characteristic phases (I–III). (I) When approaching, the blowfly induces an airflow signal near the spider with only little fluctuation (0.013 ± 0.006 m s−1) and a strength that increases nearly exponentially with time (maximum: 0.164 ± 0.051 m s−1 s.d.). The spider detects this flow while the fly is still 38.4 ± 5.6 mm away. The fluctuation of the airflow above the sensors increases linearly up to 0.037 m s−1 with the fly's altitude. Differences in the time of arrival and intensity of the fly signal at different legs probably inform the spider about the direction to the prey. (II) Phase II abruptly follows phase I with a much higher degree of fluctuation (fluctuation amplitudes: 0.114 ± 0.050 m s−1). It starts when the fly is directly above the sensor and corresponds to the time-dependent flow in the wake below and behind the fly. Its onset indicates to the spider that its prey is now within reach and triggers its jump. The spider derives information on the fly's position from the airflow characteristics, enabling it to properly time its jump. The horizontal velocity of the approaching fly is reflected by the time of arrival differences (ranging from 0.038 to 0.108 s) of the flow at different legs and the exponential velocity growth rate (16–79 s−1) during phase I. (III) The air flow velocity decays again after the fly has passed the spider. PMID:22572032

  18. Airflow elicits a spider's jump towards airborne prey. I. Airflow around a flying blowfly.

    PubMed

    Klopsch, Christian; Kuhlmann, Hendrik C; Barth, Friedrich G

    2012-10-01

    The hunting spider Cupiennius salei uses airflow generated by flying insects for the guidance of its prey-capture jump. We investigated the velocity field of the airflow generated by a freely flying blowfly close to the flow sensors on the spider's legs. It shows three characteristic phases (I-III). (I) When approaching, the blowfly induces an airflow signal near the spider with only little fluctuation (0.013 ± 0.006 m s(-1)) and a strength that increases nearly exponentially with time (maximum: 0.164 ± 0.051 m s(-1) s.d.). The spider detects this flow while the fly is still 38.4 ± 5.6 mm away. The fluctuation of the airflow above the sensors increases linearly up to 0.037 m s(-1) with the fly's altitude. Differences in the time of arrival and intensity of the fly signal at different legs probably inform the spider about the direction to the prey. (II) Phase II abruptly follows phase I with a much higher degree of fluctuation (fluctuation amplitudes: 0.114 ± 0.050 m s(-1)). It starts when the fly is directly above the sensor and corresponds to the time-dependent flow in the wake below and behind the fly. Its onset indicates to the spider that its prey is now within reach and triggers its jump. The spider derives information on the fly's position from the airflow characteristics, enabling it to properly time its jump. The horizontal velocity of the approaching fly is reflected by the time of arrival differences (ranging from 0.038 to 0.108 s) of the flow at different legs and the exponential velocity growth rate (16-79 s(-1)) during phase I. (III) The air flow velocity decays again after the fly has passed the spider. PMID:22572032

  19. Gage for measuring fluted oil field tubular members

    SciTech Connect

    Case, W.A.; Burt, J.R.

    1987-03-17

    A gage is described for measuring the nominal diameter of an elongated tubular member having circumferentially spaced apart radially outwardly extending flutes and for calibrating the amount of wear to the flutes and predicting the future wear life of the tubular member. The gage comprises: a first gage part including a pair of spaced apart colinear elongated first handlebar halves with a generally semi-circular first half ring positioned between the first handlebar halves. The first half ring includes at least one flute engaging surface which includes stepped arcuate flute engaging portions positioned at radii from the center of the first ring half corresponding to different diameters to be measured; a second gage part including a pair of spaced apart colinear elongated second handlebar halves with a generally semicircular second half ring positioned between the second handlebar halves. The second half ring includes at least one flute engaging surface which includes stepped arcuate flute engaging portions positioned a radii from the center of the second ring half corresponding to different diameters to be measured. The number of flute engaging surfaces of the first and second ring halves is equal to the number of flutes on the tubular member; and a hinge pivotally connecting together one handlebar half of the first gage part to one handlebar half of the second gage part.

  20. Cost effectiveness of the stream-gaging program in Nevada

    USGS Publications Warehouse

    Arteaga, F.E.

    1990-01-01

    The stream-gaging network in Nevada was evaluated as part of a nationwide effort by the U.S. Geological Survey to define and document the most cost-effective means of furnishing streamflow information. Specifically, the study dealt with 79 streamflow gages and 2 canal-flow gages that were under the direct operation of Nevada personnel as of 1983. Cost-effective allocations of resources, including budget and operational criteria, were studied using statistical procedures known as Kalman-filtering techniques. The possibility of developing streamflow data at ungaged sites was evaluated using flow-routing and statistical regression analyses. Neither of these methods provided sufficiently accurate results to warrant their use in place of stream gaging. The 81 gaging stations were being operated in 1983 with a budget of $465,500. As a result of this study, all existing stations were determined to be necessary components of the program for the foreseeable future. At the 1983 funding level, the average standard error of streamflow records was nearly 28%. This same overall level of accuracy could have been maintained with a budget of approximately $445,000 if the funds were redistributed more equitably among the gages. The maximum budget analyzed, $1,164 ,000 would have resulted in an average standard error of 11%. The study indicates that a major source of error is lost data. If perfectly operating equipment were available, the standard error for the 1983 program and budget could have been reduced to 21%. (Thacker-USGS, WRD)

  1. Strain gage selection in loads equations using a genetic algorithm

    NASA Technical Reports Server (NTRS)

    1994-01-01

    Traditionally, structural loads are measured using strain gages. A loads calibration test must be done before loads can be accurately measured. In one measurement method, a series of point loads is applied to the structure, and loads equations are derived via the least squares curve fitting algorithm using the strain gage responses to the applied point loads. However, many research structures are highly instrumented with strain gages, and the number and selection of gages used in a loads equation can be problematic. This paper presents an improved technique using a genetic algorithm to choose the strain gages used in the loads equations. Also presented are a comparison of the genetic algorithm performance with the current T-value technique and a variant known as the Best Step-down technique. Examples are shown using aerospace vehicle wings of high and low aspect ratio. In addition, a significant limitation in the current methods is revealed. The genetic algorithm arrived at a comparable or superior set of gages with significantly less human effort, and could be applied in instances when the current methods could not.

  2. Investigation of factors affecting the calibration of strain gage based transducers ( Goodzeit gages'') for SSC magnets

    SciTech Connect

    Davidson, M.; Gilbertson, A.; Dougherty, M.

    1991-03-01

    These transducers are designed to measure stresses on SSC collared coils. They are individually calibrated with a bonded ten-stack of SSC inner coil cable by applying a known load and reading corresponding output from the gages. The transducer is supported by a notched backing plate'' that allows for bending of the gage beam during calibration or in use with an actual coil. Several factors affecting the calibration and use of the transducers are: the number of times a backing plate'' is used, the similarities or difficulties between bonded ten-stacks, and the differences between the ten-stacks and the coil they represent. The latter is probably the most important because a calibration curve is a model of how a transducer should react within a coil. If the model is wrong, the calibration curve is wrong. Information will be presented regarding differences in calibrations between Brookhaven National Labs (also calibrating these transducers) and Fermilab -- what caused these differences, the investigation into the differences between coils and ten-stacks and how they relate to transducer calibration, and some suggestions for future calibrations.

  3. Experimental investigation of transient thermal behavior of an airship under different solar radiation and airflow conditions

    NASA Astrophysics Data System (ADS)

    Li, De-Fu; Xia, Xin-Lin; Sun, Chuang

    2014-03-01

    Knowledge of the thermal behavior of airships is crucial to the development of airship technology. An experiment apparatus is constructed to investigate the thermal response characteristics of airships, and the transient temperature distributions of both hull and inner gas are obtained under the irradiation of a solar simulator and various airflow conditions. In the course of the research, the transient temperature change of the experimental airship is measured for four airflow speeds of 0 m/s (natural convection), 3.26 m/s, 5.5 m/s and 7.0 m/s, and two incident solar radiation values of 842.4 W/m2 and 972.0 W/m2. The results show that solar irradiation has significant influence on the airship hull and inner gas temperatures even if the airship stays in a ground airflow environment where the heat transfer is dominated by radiation and convection. The airflow around the airship is conducive to reduce the hull temperature and temperature nonuniformity. Transient thermal response of airships rapidly varies with time under solar radiation conditions and the hull temperature remains approximately constant in ˜5-10 min. Finally, a transient thermal model of airship is developed and the model is validated through comparison with the experimental data.

  4. Study on airflow characteristics in the semi-closed irregular narrow flow channel

    NASA Astrophysics Data System (ADS)

    Jin, Yuzhen; Hu, Xiaodong; Zhu, Linhang; Hu, Xudong; Jin, Yingzi

    2016-04-01

    The air-jet loom is widely used in the textile industry. The interaction mechanism of airflow and yarn is not clear in such a narrow flow channel, the gas consumption is relatively large, the yarn motion is unstable and the weft insertion is often interrupted during the operation. In order to study the characteristics of the semi-closed flow field in profiled dents, the momentum conservation equation is modified and the model parameters and boundary conditions are set. Compared with the different r, the ratio of profiled dent's thickness and gap, the results show that the smaller the r is, the smaller the velocity fluctuations of the airflow is. When the angle of profiled dents α is close to zero, the diffusion of the airflow will be less. The experiment is also conducted to verify the result of the simulation with a high-speed camera and pressure sensor in profiled dents. The airflow characteristics in the semi-closed irregular narrow flow channel in the paper would provide the theoretical basis for optimizing the weft insertion process of the air-jet loom.

  5. Usability Evaluation of a Flight-Deck Airflow Hazard Visualization System

    NASA Technical Reports Server (NTRS)

    Aragon, Cecilia R.

    2004-01-01

    Many aircraft accidents each year are caused by encounters with unseen airflow hazards near the ground, such as vortices, downdrafts, low level wind shear, microbursts, or turbulence from surrounding vegetation or structures near the landing site. These hazards can be dangerous even to airliners; there have been hundreds of fatalities in the United States in the last two decades attributable to airliner encounters with microbursts and low level wind shear alone. However, helicopters are especially vulnerable to airflow hazards because they often have to operate in confined spaces and under operationally stressful conditions (such as emergency search and rescue, military or shipboard operations). Providing helicopter pilots with an augmented-reality display visualizing local airflow hazards may be of significant benefit. However, the form such a visualization might take, and whether it does indeed provide a benefit, had not been studied before our experiment. We recruited experienced military and civilian helicopter pilots for a preliminary usability study to evaluate a prototype augmented-reality visualization system. The study had two goals: first, to assess the efficacy of presenting airflow data in flight; and second, to obtain expert feedback on sample presentations of hazard indicators to refine our design choices. The study addressed the optimal way to provide critical safety information to the pilot, what level of detail to provide, whether to display specific aerodynamic causes or potential effects only, and how to safely and effectively shift the locus of attention during a high-workload task. Three-dimensional visual cues, with varying shape, color, transparency, texture, depth cueing, and use of motion, depicting regions of hazardous airflow, were developed and presented to the pilots. The study results indicated that such a visualization system could be of significant value in improving safety during critical takeoff and landing operations, and also

  6. Cost effectiveness of the stream-gaging program in Pennsylvania

    USGS Publications Warehouse

    Flippo, H.N.; Behrendt, T.E.

    1985-01-01

    This report documents a cost-effectiveness study of the stream-gaging program in Pennsylvania. Data uses and funding were identified for 223 continuous-record stream gages operated in 1983; four are planned for discontinuance at the close of water-year 1985; two are suggested for conversion, at the beginning of the 1985 water year, for the collection of only continuous stage records. Two of 11 special-purpose short-term gages are recommended for continuation when the supporting project ends; eight of these gages are to be discontinued and the other will be converted to a partial-record type. Current operation costs for the 212 stations recommended for continued operation is $1,199,000 per year in 1983. The average standard error of estimation for instantaneous streamflow is 15.2%. An overall average standard error of 9.8% could be attained on a budget of $1,271,000, which is 6% greater than the 1983 budget, by adopted cost-effective stream-gaging operations. (USGS)

  7. Study of airflow during respiratory cycle in semi-realistic model of human tracheobronchial tree

    NASA Astrophysics Data System (ADS)

    Elcner, Jakub; Zaremba, M.; Maly, M.; Jedelsky, J.; Lizal, F.; Jicha, M.

    2016-06-01

    This article deals with study of airflow under breathing process, which is characteristic by unsteady behavior. Simulations provided by computational fluid dynamics (CFD) was compared with experiments performed on similar geometry of human upper airways. This geometry was represented by mouth cavity of realistic shape connected to an idealized tracheobronchial tree up to fourth generation of branching. Commercial CFD software Star-CCM+ was used to calculate airflow inside investigated geometry and method of Reynolds averaging of Navier-Stokes equations was used for subscribing the turbulent behavior through model geometry. Conditions corresponding to resting state were considered. Comparisons with experiments were provided on several points through trachea and bronchial tree and results with respect to inspiratory and respiratory part of breathing cycle was discussed.

  8. Payload bay atmospheric vent airflow testing at the Vibration and Acoustic Test Facility

    NASA Technical Reports Server (NTRS)

    Johnston, James D., Jr.

    1988-01-01

    Several concerns related to venting the Space Shuttle Orbiter payload bay during launch led to laboratory experiments with a flight-type vent box installed in the wall of a subsonic wind tunnel. This report describes the test setups and procedures used to acquire data for characterization of airflow through the vent box and acoustic tones radiated from the vent-box cavity. A flexible boundary-layer spoiler which reduced the vent-tone amplitude is described.

  9. Empirical Observations on the Sensitivity of Hot Cathode Ionization Type Vacuum Gages

    NASA Technical Reports Server (NTRS)

    Summers, R. L.

    1969-01-01

    A study of empirical methods of predicting tile relative sensitivities of hot cathode ionization gages is presented. Using previously published gage sensitivities, several rules for predicting relative sensitivity are tested. The relative sensitivity to different gases is shown to be invariant with gage type, in the linear range of gage operation. The total ionization cross section, molecular and molar polarizability, and refractive index are demonstrated to be useful parameters for predicting relative gage sensitivity. Using data from the literature, the probable error of predictions of relative gage sensitivity based on these molecular properties is found to be about 10 percent. A comprehensive table of predicted relative sensitivities, based on empirical methods, is presented.

  10. Evaluation of Pd-Cr Wires for Strain Gage Application

    NASA Technical Reports Server (NTRS)

    Lei, Jih-Fen; Greer, L. C., III; Oberle, L. G.

    1995-01-01

    A newly developed alloy, palladium-13 weight percent chromium (Pd13Cr), was identified by United Technologies Research Center under a NASA contract to be the best material for high temperature strain gage applications. An electrical resistance strain gage that can provide accurate static strain measurement to a temperature higher than that of a commercially available gage is urgently needed in aerospace and aeronautics research. A strain gage made of a 25.4 micron (1 mil) diameter Pd13Cr wire has been recently demonstrated to be usable for static strain measurements to 800 C. This compares to the 400 C temperature limit of the commercially available strain gages. The performance of the Pd-Cr gage, however, strongly depends on the quality of the Pd13Cr wire. Four batches of Pd-Cr wires purchased from three different manufacturers were therefore evaluated to determine the best source of the wire for strain gage applications. The three suppliers were Precious Metal Institute in China, Sigmund Cohn Co., and G & S Titanium, Inc. in the United States. Two batches of wires obtained from Previous Metal Institute in 1987 and 1992, respectively are referred to herein as China87 and China92 wires. The mechanical, chemical and electrical properties of these wires, both as-received and after high temperature exposures at 800 C for 50 hours were analyzed. The elastic modulus and the failure strength of the wires were evaluated using a tensile test machine equipped with a laser speckle strain measurement system. The chemical and microstructural properties of the wires were inspected using a plasma atomic emission spectrometer and a scanning electron microscope (SEM) equipped with an energy dispersive X-ray spectroscope (EDS). The electrical stability and repeatability of the wires were determined by measuring the electrical resistance of the wires during three thermal cycles to 1000 C and a ten-hour soak at 1000 C. As a result of this study, the wire which has the highest

  11. Laboratory and field evaluation of an underwater sand height gage

    NASA Technical Reports Server (NTRS)

    Swift, D. J. P.; Mcgrath, D. G.

    1972-01-01

    An underwater sand height gage was investigated. This instrument consisted of two transducers, one screened and one unscreened. Laboratory experimentation included static and dynamic tests with three test sands--fine, medium, and coarse. Field tests were conducted at Rudee Inlet, Virginia Beach, Virginia. Test results showed a linear response to up to 10 inches of sand loading. Deviation observed in identical tests appeared to be due to variation in the density of sand. Density differences reflected varying packing styles which, in turn, were a consequence of grain size and flow regime. Further evaluations of the sand height gage reflect this instrument's potential.

  12. Evaluation of Pd-Cr wires for strain gage application

    NASA Astrophysics Data System (ADS)

    Lei, Jih-Fen; Greer, L. C., III; Oberle, L. G.

    1995-02-01

    A newly developed alloy, palladium-13 weight percent chromium (Pd13Cr), was identified by United Technologies Research Center under a NASA contract to be the best material for high temperature strain gage applications. An electrical resistance strain gage that can provide accurate static strain measurement to a temperature higher than that of a commercially available gage is urgently needed in aerospace and aeronautics research. A strain gage made of a 25.4 micron (1 mil) diameter Pd13Cr wire has been recently demonstrated to be usable for static strain measurements to 800 C. This compares to the 400 C temperature limit of the commercially available strain gages. The performance of the Pd-Cr gage, however, strongly depends on the quality of the Pd13Cr wire. Four batches of Pd-Cr wires purchased from three different manufacturers were therefore evaluated to determine the best source of the wire for strain gage applications. The three suppliers were Precious Metal Institute in China, Sigmund Cohn Co., and G & S Titanium, Inc. in the United States. Two batches of wires obtained from Previous Metal Institute in 1987 and 1992, respectively are referred to herein as China87 and China92 wires. The mechanical, chemical and electrical properties of these wires, both as-received and after high temperature exposures at 800 C for 50 hours were analyzed. The elastic modulus and the failure strength of the wires were evaluated using a tensile test machine equipped with a laser speckle strain measurement system. The chemical and microstructural properties of the wires were inspected using a plasma atomic emission spectrometer and a scanning electron microscope (SEM) equipped with an energy dispersive X-ray spectroscope (EDS). The electrical stability and repeatability of the wires were determined by measuring the electrical resistance of the wires during three thermal cycles to 1000 C and a ten-hour soak at 1000 C. As a result of this study, the wire which has the highest

  13. The Evolution of Unidirectional Pulmonary Airflow.

    PubMed

    Farmer, C G

    2015-07-01

    Conventional wisdom holds that the avian respiratory system is unique because air flows in the same direction through most of the gas-exchange tubules during both phases of ventilation. However, recent studies showing that unidirectional airflow also exists in crocodilians and lizards raise questions about the true phylogenetic distribution of unidirectional airflow, the selective drivers of the trait, the date of origin, and the functional consequences of this phenomenon. These discoveries suggest unidirectional flow was present in the common diapsid ancestor and are inconsistent with the traditional paradigm that unidirectional flow is an adaptation for supporting high rates of gas exchange. Instead, these discoveries suggest it may serve functions such as decreasing the work of breathing, decreasing evaporative respiratory water loss, reducing rates of heat loss, and facilitating crypsis. The divergence in the design of the respiratory system between unidirectionally ventilated lungs and tidally ventilated lungs, such as those found in mammals, is very old, with a minimum date for the divergence in the Permian Period. From this foundation, the avian and mammalian lineages evolved very different respiratory systems. I suggest the difference in design is due to the same selective pressure, expanded aerobic capacity, acting under different environmental conditions. High levels of atmospheric oxygen of the Permian Period relaxed selection for a thin blood-gas barrier and may have resulted in the homogeneous, broncho-alveolar design, whereas the reduced oxygen of the Mesozoic selected for a heterogeneous lung with an extremely thin blood-gas barrier. These differences in lung design may explain the puzzling pattern of ecomorphological diversification of Mesozoic mammals: all were small animals that did not occupy niches requiring a great aerobic capacity. The broncho-alveolar lung and the hypoxia of the Mesozoic may have restricted these mammals from exploiting

  14. Dynamics of airflow in a short inhalation

    PubMed Central

    Bates, A. J.; Doorly, D. J.; Cetto, R.; Calmet, H.; Gambaruto, A. M.; Tolley, N. S.; Houzeaux, G.; Schroter, R. C.

    2015-01-01

    During a rapid inhalation, such as a sniff, the flow in the airways accelerates and decays quickly. The consequences for flow development and convective transport of an inhaled gas were investigated in a subject geometry extending from the nose to the bronchi. The progress of flow transition and the advance of an inhaled non-absorbed gas were determined using highly resolved simulations of a sniff 0.5 s long, 1 l s−1 peak flow, 364 ml inhaled volume. In the nose, the distribution of airflow evolved through three phases: (i) an initial transient of about 50 ms, roughly the filling time for a nasal volume, (ii) quasi-equilibrium over the majority of the inhalation, and (iii) a terminating phase. Flow transition commenced in the supraglottic region within 20 ms, resulting in large-amplitude fluctuations persisting throughout the inhalation; in the nose, fluctuations that arose nearer peak flow were of much reduced intensity and diminished in the flow decay phase. Measures of gas concentration showed non-uniform build-up and wash-out of the inhaled gas in the nose. At the carina, the form of the temporal concentration profile reflected both shear dispersion and airway filling defects owing to recirculation regions. PMID:25551147

  15. Methane emissions and airflow patterns along longwall faces and through bleeder ventilation systems

    PubMed Central

    Schatzel, Steven J.; Dougherty, Heather N.

    2015-01-01

    The National Institute for Occupational Safety and Health (NIOSH) conducted an investigation of longwall face and bleeder ventilation systems using tracer gas experiments and computer network ventilation. The condition of gateroad entries, along with the caved material’s permeability and porosity changes as the longwall face advances, determine the resistance of the airflow pathways within the longwall’s worked-out area of the bleeder system. A series of field evaluations were conducted on a four-panel longwall district. Tracer gas was released at the mouth of the longwall section or on the longwall face and sampled at various locations in the gateroads inby the shield line. Measurements of arrival times and concentrations defined airflow/gas movements for the active/completed panels and the bleeder system, providing real field data to delineate these pathways. Results showed a sustained ability of the bleeder system to ventilate the longwall tailgate corner as the panels retreated. PMID:26925166

  16. The coupling influence of airflow and temperature on the wall-wetted fuel film distribution

    SciTech Connect

    Cheng, Yong-sheng; Deng, Kangyao; Li, Tao

    2010-02-15

    The coupling influence of airflow and temperature on the two-dimensional distribution of the film resulted from fuel spray impinging on a horizontal flat wall was studied with experiments. The horizontal airflow direction was perpendicular to the vertical axis of the injection spray. The results show that, as air velocity increases, the film shape turns from a circle to an oblong. As wall temperature increases, the film area shrinks. Film thickness decreases as wall temperature or air velocity increases. The boiling point of the fuel is an important temperature to affect the film area and the film thickness. Film center moves more far away in the downstream direction as air velocity increases. For a certain air velocity, film center moves less far away as wall temperature increases. (author)

  17. Development and calibration of buried wire gages for wall shear stress measurements in fluid flow

    NASA Technical Reports Server (NTRS)

    Murthy, Sreedhara V.; Steinle, Frank W.

    1988-01-01

    Special methods were developed to arrange 'Buried Wire Gage' inserts flush to the contoured flow surfaces of instrument plugs of a boundary-layer flow apparatus. The fabrication process was aimed at producing proper bonding of the sensor wire to the substrate surface, without causing excessive surface waviness. A large number of gages were built and first calibrated for the resistance-temperature characteristics. The gages were then installed in a flow calibration apparatus and operated from a constant temperature anemometer system for a series of flow settings to derive the calibration constants of each of the gages. The flow settings included a range of subsonic freestream Mach numbers in order to help establish the gage calibration characteristics for compressible flow fields. This paper provides a description of the buried wire gage technique, an explanation of the method evolved for making proper gages, the procedure for calibrating the gages and the results of measurements performed for determining the calibration constants.

  18. Measuring rates of outdoor airflow into HVAC systems

    SciTech Connect

    Fisk, William J.; Faulkner, David; Sullivan, Douglas P.; Delp, Woody

    2002-10-01

    During the last few years, new technologies have been introduced for measuring the flow rates of outside air into HVAC systems. This document describes one particular technology for measuring these airflows, a system and a related protocol developed to evaluate this and similar measurement technologies under conditions without wind, and the results of our evaluations. We conclude that the measurement technology evaluated can provide a reasonably accurate measurement of OA flow rate over a broad range of flow, without significantly increasing airflow resistance.

  19. 13. VIEW OF SHEFFIELD GAGE, USED TO MEASURE ROUNDNESS OF ...

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

    13. VIEW OF SHEFFIELD GAGE, USED TO MEASURE ROUNDNESS OF WEAPON PARTS, AS PART OF THE FINAL PARTS INSPECTION PROCESS. (6/2/67) - Rocky Flats Plant, Non-Nuclear Production Facility, South of Cottonwood Avenue, west of Seventh Avenue & east of Building 460, Golden, Jefferson County, CO

  20. 49 CFR 179.400-19 - Valves and gages.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... jacket. The dip tube must indicate the maximum liquid level for the allowable filling density. The inner... Liquid Tank Car Tanks and Seamless Steel Tanks (Classes DOT-113 and 107A) § 179.400-19 Valves and gages... control of vapor phase pressure, vapor phase venting, liquid transfer and liquid flow rates. All...

  1. 49 CFR 179.400-19 - Valves and gages.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... jacket. The dip tube must indicate the maximum liquid level for the allowable filling density. The inner... Liquid Tank Car Tanks and Seamless Steel Tanks (Classes DOT-113 and 107A) § 179.400-19 Valves and gages... control of vapor phase pressure, vapor phase venting, liquid transfer and liquid flow rates. All...

  2. 49 CFR 179.400-19 - Valves and gages.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... jacket. The dip tube must indicate the maximum liquid level for the allowable filling density. The inner... Liquid Tank Car Tanks and Seamless Steel Tanks (Classes DOT-113 and 107A) § 179.400-19 Valves and gages... control of vapor phase pressure, vapor phase venting, liquid transfer and liquid flow rates. All...

  3. Latin-square three-dimensional gage master

    DOEpatents

    Jones, L.

    1981-05-12

    A gage master for coordinate measuring machines has an nxn array of objects distributed in the Z coordinate utilizing the concept of a Latin square experimental design. Using analysis of variance techniques, the invention may be used to identify sources of error in machine geometry and quantify machine accuracy.

  4. Polymer deformation gage measures thickness change in tensile tests

    NASA Technical Reports Server (NTRS)

    Broyles, H. F.; Broyles, H. H.

    1966-01-01

    Lightweight deformation gage attached to a polymer specimen determines the thickness changes undergone by the specimen during the testing of its tensile and elongation properties. Mechanical noise from outside sources is dampened when the assembly is hung on a light rubber band.

  5. 42 CFR 84.82 - Gas pressure gages; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Gas pressure gages; minimum requirements. 84.82 Section 84.82 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES...

  6. 49 CFR 213.110 - Gage restraint measurement systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION TRACK SAFETY STANDARDS Track Structure § 213.110 Gage restraint... section. (4) When a functional PTLF is not available to a fully qualified person designated under § 213.7... requirements specified in §§ 213.109 and 213.127. (5) If the PTLF becomes non-functional or is missing,...

  7. High temperature strain gage technology for gas turbine engines

    NASA Astrophysics Data System (ADS)

    Fichtel, Edward J.; McDaniel, Amos D.

    1994-08-01

    This report summarizes the results of a six month study that addressed specific issues to transfer the Pd-13Cr static strain sensor to a gas turbine engine environment. The application issues that were addressed include: (1) evaluation of a miniature, variable potentiometer for use as the ballast resistor, in conjunction with a conventional strain gage signal conditioning unit; (2) evaluation of a metal sheathed, platinum conductor leadwire assembly for use with the three-wire sensor; and (3) subjecting the sensor to dynamic strain cyclic testing to determine fatigue characteristics. Results indicate a useful static strain gage system at all temperature levels up to 1350 F. The fatigue characteristics also appear to be very promising, indicating a potential use in dynamic strain measurement applications. The procedure, set-up, and data for all tests are presented in this report. This report also discusses the specific strain gage installation technique for the Pd-13Cr gage because of its potential impact on the quality of the output data.

  8. High temperature strain gage technology for gas turbine engines

    NASA Technical Reports Server (NTRS)

    Fichtel, Edward J.; Mcdaniel, Amos D.

    1994-01-01

    This report summarizes the results of a six month study that addressed specific issues to transfer the Pd-13Cr static strain sensor to a gas turbine engine environment. The application issues that were addressed include: (1) evaluation of a miniature, variable potentiometer for use as the ballast resistor, in conjunction with a conventional strain gage signal conditioning unit; (2) evaluation of a metal sheathed, platinum conductor leadwire assembly for use with the three-wire sensor; and (3) subjecting the sensor to dynamic strain cyclic testing to determine fatigue characteristics. Results indicate a useful static strain gage system at all temperature levels up to 1350 F. The fatigue characteristics also appear to be very promising, indicating a potential use in dynamic strain measurement applications. The procedure, set-up, and data for all tests are presented in this report. This report also discusses the specific strain gage installation technique for the Pd-13Cr gage because of its potential impact on the quality of the output data.

  9. Development of an ultrasonic airflow measurement device for ducted air.

    PubMed

    Raine, Andrew B; Aslam, Nauman; Underwood, Christopher P; Danaher, Sean

    2015-01-01

    In this study, an in-duct ultrasonic airflow measurement device has been designed, developed and tested. The airflow measurement results for a small range of airflow velocities and temperatures show that the accuracy was better than 3.5% root mean square (RMS) when it was tested within a round or square duct compared to the in-line Venturi tube airflow meter used for reference. This proof of concept device has provided evidence that with further development it could be a low-cost alternative to pressure differential devices such as the orifice plate airflow meter for monitoring energy efficiency performance and reliability of ventilation systems. The design uses a number of techniques and design choices to provide solutions to lower the implementation cost of the device compared to traditional airflow meters. The design choices that were found to work well are the single sided transducer arrangement for a "V" shaped reflective path and the use of square wave transmitter pulses ending with the necessary 180° phase changed pulse train to suppress transducer ringing. The device is also designed so that it does not have to rely on high-speed analogue to digital converters (ADC) and intensive digital signal processing, so could be implemented using voltage comparators and low-cost microcontrollers. PMID:25954952

  10. Development of an Ultrasonic Airflow Measurement Device for Ducted Air

    PubMed Central

    Raine, Andrew B.; Aslam, Nauman; Underwood, Christopher P.; Danaher, Sean

    2015-01-01

    In this study, an in-duct ultrasonic airflow measurement device has been designed, developed and tested. The airflow measurement results for a small range of airflow velocities and temperatures show that the accuracy was better than 3.5% root mean square (RMS) when it was tested within a round or square duct compared to the in-line Venturi tube airflow meter used for reference. This proof of concept device has provided evidence that with further development it could be a low-cost alternative to pressure differential devices such as the orifice plate airflow meter for monitoring energy efficiency performance and reliability of ventilation systems. The design uses a number of techniques and design choices to provide solutions to lower the implementation cost of the device compared to traditional airflow meters. The design choices that were found to work well are the single sided transducer arrangement for a “V” shaped reflective path and the use of square wave transmitter pulses ending with the necessary 180° phase changed pulse train to suppress transducer ringing. The device is also designed so that it does not have to rely on high-speed analogue to digital converters (ADC) and intensive digital signal processing, so could be implemented using voltage comparators and low-cost microcontrollers. PMID:25954952

  11. Evaluation of candidate rain gages for upgrading precipitation measurement tools for the National Atmospheric Deposition Program

    USGS Publications Warehouse

    Gordon, John D.

    2003-01-01

    The National Atmospheric Deposition Program (NADP) was established in 1977 to investigate atmospheric deposition and its effects on the environment. Since its establishment, precipitation records have been obtained at all NADP sites using a gage developed approximately 50 years ago-the Belfort 5-780 mechanical rain gage. In 1998 and 1999, a study was done by the U.S. Geological Survey to evaluate four recently developed, technologically advanced rain gages as possible replacement candidates for the mechanical gage currently (2002) in use by the NADP. The gage types evaluated were the Belfort 3200, Geonor T-200, ETI Noah II, and the OTT PLUVIO. The Belfort 5-780 was included in the study to compare the performance of the rain gage currently (2002) used by NADP to the performance of the more recently developed gages. As a reference gage, the NovaLynx Model 260-2510 National Weather Service type stick gage also was included in the study. Two individual gages of each type were included in the study to evaluate precision between gages of the same type. A two-phase evaluation was completed. Phase I consisted of indoor bench tests with known amounts of simulated rainfall applied in 20 individual tests. Phase II consisted of outdoor testing by collecting precipitation during a 26-week period near Bay St. Louis, Mississippi. The ETI Noah II, OTT PLUVIO, and NovaLynx stick gages consistently recorded depths more commensurate with the amounts of applied simulated rainfall in Phase I testing than the Geonor T-200, Belfort 5-780, and Belfort 3200 gages. Gages where both the median difference between the measured and applied simulated rainfall and the interquartile range of all of their measured minus applied simulated rainfall differences were small (less than or equal to 0.01 inch) were judged to have performed very well in Phase I testing. The median and interquartile-range values were 0.01 inch or less for each of the ETI Noah II gages, OTT PLUVIO gages, and NovaLynx stick

  12. 49 CFR 213.143 - Frog guard rails and guard faces; gage.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Frog guard rails and guard faces; gage. 213.143... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION TRACK SAFETY STANDARDS Track Structure § 213.143 Frog guard rails and guard faces; gage. The guard check and guard face gages in frogs shall be within the...

  13. 49 CFR 213.143 - Frog guard rails and guard faces; gage.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Frog guard rails and guard faces; gage. 213.143... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION TRACK SAFETY STANDARDS Track Structure § 213.143 Frog guard rails and guard faces; gage. The guard check and guard face gages in frogs shall be within the...

  14. 49 CFR 213.143 - Frog guard rails and guard faces; gage.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Frog guard rails and guard faces; gage. 213.143... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION TRACK SAFETY STANDARDS Track Structure § 213.143 Frog guard rails and guard faces; gage. The guard check and guard face gages in frogs shall be within the...

  15. 49 CFR 213.143 - Frog guard rails and guard faces; gage.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Frog guard rails and guard faces; gage. 213.143... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION TRACK SAFETY STANDARDS Track Structure § 213.143 Frog guard rails and guard faces; gage. The guard check and guard face gages in frogs shall be within the...

  16. 49 CFR 213.143 - Frog guard rails and guard faces; gage.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Frog guard rails and guard faces; gage. 213.143... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION TRACK SAFETY STANDARDS Track Structure § 213.143 Frog guard rails and guard faces; gage. The guard check and guard face gages in frogs shall be within the...

  17. 46 CFR 38.10-20 - Liquid level gaging devices-TB/ALL.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Liquid level gaging devices-TB/ALL. 38.10-20 Section 38... Piping, Valves, Fittings, and Accessory Equipment § 38.10-20 Liquid level gaging devices—TB/ALL. (a) Each tank shall be fitted with a liquid level gaging device of approved design to indicate the maximum...

  18. 46 CFR 38.10-20 - Liquid level gaging devices-TB/ALL.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Liquid level gaging devices-TB/ALL. 38.10-20 Section 38... Piping, Valves, Fittings, and Accessory Equipment § 38.10-20 Liquid level gaging devices—TB/ALL. (a) Each tank shall be fitted with a liquid level gaging device of approved design to indicate the maximum...

  19. 46 CFR 38.10-20 - Liquid level gaging devices-TB/ALL.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Liquid level gaging devices-TB/ALL. 38.10-20 Section 38... Piping, Valves, Fittings, and Accessory Equipment § 38.10-20 Liquid level gaging devices—TB/ALL. (a) Each tank shall be fitted with a liquid level gaging device of approved design to indicate the maximum...

  20. 46 CFR 38.10-20 - Liquid level gaging devices-TB/ALL.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Liquid level gaging devices-TB/ALL. 38.10-20 Section 38... Piping, Valves, Fittings, and Accessory Equipment § 38.10-20 Liquid level gaging devices—TB/ALL. (a) Each tank shall be fitted with a liquid level gaging device of approved design to indicate the maximum...

  1. Using Gage Blocks as Measuring Standards, Aviation Quality Control (Basic): 9225.03.

    ERIC Educational Resources Information Center

    Dade County Public Schools, Miami, FL.

    This unit of instruction deals with a study of the evolution and history of gage blocks and optical flats as measuring tools. Theory and principles are covered in detail. Considerable time is spent on the techniques of using gage blocks and optical flats in actual measurement set-ups. Included is the calibration and care of gage blocks and optical…

  2. Experimental Evaluation of White Light Fabry-Perot Interferometry Fiber-Optic Strain Gages when Measuring Small Strains

    NASA Technical Reports Server (NTRS)

    St.Cyr, William; Figueroa, Fernando; VanDyke, David; McVay, Greg; Mitchell, Mark

    2002-01-01

    An experimental study was conducted to evaluate whether fiber optic strain gages (FOSG) are "better" sensors than typical foil gages. A particularly attractive feature of FOSG was their specified resolution of 0.01% of full-scale (0.1 micro strain for 1000 micro strain full-scale). This feature would make FOSG practical tank level sensors, by measuring very small strains on the support structure of a tank. A specific application in mind was to measure liquid oxygen tank level, with support beams that were predicted to contract approximately 11 micro strain as the tank goes from empty to full. Among various fiber optic technologies currently available, Fabry-Perot Interferometry using white light was selected. This technology exhibits highly desirable feature such as absolute strain measurement, linearity over its full-scale, and temperature compensation. However, experiment results suggest that the resolution is 0.8 micro strain, at best, calibration from one sensor to another can be off by 2.4 - 11.2%, and that temperature compensation is not fully predictable, with errors of up to 3.5 micro strain over an 11C range. Hence, when compared with classic foil gages, FOSG possess less accuracy, similar resolution and repeatability (precision), and superior linearity over their entire operating range. They are immune to EMI and their signals suffer minimal degradation over long distances. It is also expected that drift with time will be minimal in FOSG whereas the gage factor of foil sensors changes over time when exposed to varying environmental conditions. In conclusion, FOSG are "better" than foil gages as long as the application allows calibration of individual units as installed for operation.

  3. Alumina Encapsulated Strain Gage Not Mechanically Attached To The Substrate, Used to Temperature Compensate an Active High Temperature Gage In A Half-Bridge Configuration

    NASA Technical Reports Server (NTRS)

    Piazza, Anthony (Inventor)

    2001-01-01

    A temperature compensation element for a high-temperature strain gage and the method of fabricating the same. Preferably, the element is a "dummy" strain gage not mechanically attached to the substrate. The element is encapsulated in an insulative material and used to compensate an active high-temperature strain gage and wired in a half-bridge configuration. The temperature compensation element and high-temperature strain gage are fabricated using the method of the present invention. This method includes temporarily adhering the element to a heat sink, encapsulated in an insulative material and then removed from the heat sink. Next, the element is either stacked or placed near the active gage. Ideally, the element and the active gage have substantially similar heat transfer and electrical properties.

  4. Behavior of submicrometer particles in periodic alveolar airflows.

    PubMed

    Balik, G; Reis, A H; Aydin, M; Miguel, A F

    2008-04-01

    Here, we report a numerical experiment in which submicrometer particle entrainment in a periodic flow that matches those existing in the alveolus in the human lung was simulated for both sedentary and light activity. A spherical cavity with a prescribed velocity profile at the inlet was used to simulate the time-dependent periodical flow of air in the alveolus. Expansion and contraction of the alveolus were simulated by setting a conceptual permeable wall as the outer surface of the model and adjusting the boundary conditions in order to match the continuity of the flow. The simulations were conducted for breathing periods of 5 and 3 s, which match sedentary and light activity conditions, respectively, and the results were extrapolated to the real lung. It was found that, most of the particles mainly followed a straightforward path and reached the opposite side of the alveolar wall in both breathing conditions. The concentration patterns obtained are consistent with the fact that the flow within the alveolus is mainly diffusive and does not greatly depend on the flow velocity. It was found that the particles which are heavier than air move out of phase with the periodic airflow that crosses the alveolus entrance, and that these particles are significantly caught within the alveolus. Particle entrapment increases with breathing rate in accordance with experimental values and indicates that increase in breathing frequency in environments with high concentration of submicrometer particles has the consequence of increasing particle entrapment by several times with respect to normal breathing rate. PMID:18075755

  5. RANS and LES simulations of the airflow through nasal cavities

    NASA Astrophysics Data System (ADS)

    Lamberti, Giacomo

    2015-11-01

    The prediction of detailed flow patterns in nasal cavities using computational fluid dynamics (CFD) can provide essential information on the potential relationship between patient-specific geometrical characteristics and health problems. The long-term goal of the OpenNOSE project is to develop a reliable open-source computational tool based on the OpenFOAM CFD toolbox that can assist surgeons in their daily practice. The objective of this study was to investigate the effect of the turbulence model and boundary conditions on simulations of the airflow in nasal cavities. The geometry, including paranasal sinuses, was reconstructed from a carefully selected CT scan, and RANS and LES simulations were carried out for steady inspiration and expiration. At a flow rate near 20 l/min, the flow is laminar in most of the domain. During the inspiration phase, turbulence develops in nasopharynx and oropharynx regions; during the expiration phase, another vortical region is observed down the nostrils. A comparison between different boundary conditions suggests the use of a total pressure condition, or alternatively a uniform velocity, at the inlet and outlet. In future work the same geometry will be used for setting up a laboratory experiment, intended to cross-validate the numerical results.

  6. Oscillating and star-shaped drops levitated by an airflow.

    PubMed

    Bouwhuis, Wilco; Winkels, Koen G; Peters, Ivo R; Brunet, Philippe; van der Meer, Devaraj; Snoeijer, Jacco H

    2013-08-01

    We investigate the spontaneous oscillations of drops levitated above an air cushion, eventually inducing a breaking of axisymmetry and the appearance of "star drops". This is strongly reminiscent of the Leidenfrost stars that are observed for drops floating above a hot substrate. The key advantage of this work is that we inject the airflow at a constant rate below the drop, thus eliminating thermal effects and allowing for a better control of the flow rate. We perform experiments with drops of different viscosities and observe stable states, oscillations, and chimney instabilities. We find that for a given drop size the instability appears above a critical flow rate, where the latter is largest for small drops. All these observations are reproduced by numerical simulations, where we treat the drop using potential flow and the gas as a viscous lubrication layer. Qualitatively, the onset of instability agrees with the experimental results, although the typical flow rates are too large by a factor 10. Our results demonstrate that thermal effects are not important for the formation of star drops and strongly suggest a purely hydrodynamic mechanism for the formation of Leidenfrost stars. PMID:24032934

  7. A miniature airflow energy harvester from piezoelectric materials

    NASA Astrophysics Data System (ADS)

    Sun, H.; Zhu, D.; White, N. M.; Beeby, S. P.

    2013-12-01

    This paper describes design, simulation, fabrication, and testing of a miniature wind energy harvester based on a flapping cantilevered piezoelectric beam. The wind generator is based on oscillations of a cantilever that faces the direction of the airflow. The oscillation is amplified by interactions between an aerofoil attached on the cantilever and a bluff body placed in front of the aerofoil. A piezoelectric transducer with screen printed PZT materials is used to extract electrical energy. To achieve the optimum design of the harvester, both computational simulations and experiments have been carried out to investigate the structure. A prototype of the wind harvester, with the volume of 37.5 cm3 in total, was fabricated by thick-film screen printing technique. Wind tunnel test results are presented to determine the optimum structure and to characterize the performance of the harvester. The optimized device finally achieved a working wind speed range from 1.5 m/s to 8 m/s. The power output was ranging from 0.1 to 0.86 μW and the open-circuit output voltage was from 0.5 V to 1.32 V.

  8. SMA actuators for vibration control and experimental determination of model parameters dependent on ambient airflow velocity

    NASA Astrophysics Data System (ADS)

    Suzuki, Y.

    2016-05-01

    This article demonstrates the practical applicability of a method of modelling shape memory alloys (SMAs) as actuators. For this study, a pair of SMA wires was installed in an antagonistic manner to form an actuator, and a linear differential equation that describes the behaviour of the actuator’s generated force relative to its input voltage was derived for the limited range below the austenite onset temperature. In this range, hysteresis need not be considered, and the proposed SMA actuator can therefore be practically applied in linear control systems, which is significant because large deformations accompanied by hysteresis do not necessarily occur in most vibration control cases. When specific values of the parameters used in the differential equation were identified experimentally, it became clear that one of the parameters was dependent on ambient airflow velocity. The values of this dependent parameter were obtained using an additional SMA wire as a sensor. In these experiments, while the airflow distribution around the SMA wires was varied by changing the rotational speed of the fans in the wind tunnels, an input voltage was conveyed to the SMA actuator circuit, and the generated force was measured. In this way, the parameter dependent on airflow velocity was estimated in real time, and it was validated that the calculated force was consistent with the measured one.

  9. Characterization of BCL strain gages for use to 1366 K (2000 F). [performance tests

    NASA Technical Reports Server (NTRS)

    Lemcoe, M. M.

    1975-01-01

    Strain gage behavior under static and transient heating conditions at various strain rates and high temperatures (1366 K(2000 F) was studied. Optimum time-temperature parameters were developed for preconditioning (prestabilizing) the gages. A limited study was carried out to determine the extent of spalling of platinum cladding during fabrication of platinum-clad wire strain gages. Further verification was also carried out on the convergence and repeatability of the apparent strain characteristics of the gage under heating and cooling cycles. The significance of these characteristics from the standpoint of enhancing measurement accuracy is also discussed. It was concluded that the gage should perform satisfactorily to temperatures approaching 1366 K (2000 F).

  10. Analysis of strain gage reliability in F-100 jet engine testing at NASA Lewis Research Center

    NASA Technical Reports Server (NTRS)

    Holanda, R.

    1983-01-01

    A reliability analysis was performed on 64 strain gage systems mounted on the 3 rotor stages of the fan of a YF-100 engine. The strain gages were used in a 65 hour fan flutter research program which included about 5 hours of blade flutter. The analysis was part of a reliability improvement program. Eighty-four percent of the strain gages survived the test and performed satisfactorily. A post test analysis determined most failure causes. Five failures were caused by open circuits, three failed gages showed elevated circuit resistance, and one gage circuit was grounded. One failure was undetermined.

  11. HOLEGAGE 1.0 - STRAIN GAGE HOLE DRILLING ANALYSIS PROGRAM

    NASA Technical Reports Server (NTRS)

    Hampton, R. W.

    1994-01-01

    There is no simple and perfect way to measure residual stresses in metal parts that have been welded or deformed to make complex structures such as pressure vessels and aircraft, yet these locked-in stresses can contribute to structural failure by fatigue and fracture. However, one proven and tested technique for determining the internal stress of a metal part is to drill a test hole while measuring the relieved strains around the hole, such as the hole-drilling strain gage method described in ASTM E 837. The program HOLEGAGE processes strain gage data and provides additional calculations of internal stress variations that are not obtained with standard E 837 analysis methods. The typical application of the technique uses a three gage rosette with a special hole-drilling fixture for drilling a hole through the center of the rosette to produce a hole with very small gage pattern eccentricity error. Another device is used to control the drilling and halt the drill at controlled depth steps. At each step, strains from all three strain gages are recorded. The influence coefficients used by HOLEGAGE to compute stresses from relieved hole strains were developed by published finite element method studies of thick plates for specific hole sizes and depths. The program uses a parabolic fit and an interpolating scheme to project the coefficients to other hole sizes and depths. Additionally, published experimental data are used to extend the coefficients to relatively thin plates. These influence coefficients are used to compute the stresses in the original part from the strain data. HOLEGAGE will compute interior planar stresses using strain data from each drilled hole depth layer. Planar stresses may be computed in three ways including: a least squares fit for a linear variation with depth, an integral method to give incremental stress data for each layer, or by a linear fit to the integral data (with some surface data points omitted) to predict surface stresses before

  12. A siphon gage for monitoring surface-water levels

    USGS Publications Warehouse

    McCobb, T.D.; LeBlanc, D.R.; Socolow, R.S.

    1999-01-01

    A device that uses a siphon tube to establish a hydraulic connection between the bottom of an onshore standpipe and a point at the bottom of a water body was designed and tested for monitoring surface-water levels. Water is added to the standpipe to a level sufficient to drive a complete slug of water through the siphoning tube and to flush all air out of the system. The water levels in the standpipe and the water body equilibrate and provide a measurable static water surface in the standpipe. The siphon gage was designed to allow quick and accurate year-round measurements with minimal maintenance. Currently available devices for monitoring surface-water levels commonly involve time-consuming and costly installation and surveying, and the movement of reference points and the presence of ice cover in cold regions cause discontinuity and inaccuracy in the data collected. Installation and field testing of a siphon gage using 0.75-in-diameter polyethylene tubing at Ashumet Pond in Falmouth, Massachusetts, demonstrated that the siphon gage can provide long-term data with a field effort and accuracy equivalent to measurement of ground-water levels at an observation well.A device that uses a siphon tube to establish a hydraulic connection between the bottom of an onshore standpipe and a point at the bottom of a water body was designed and tested for monitoring surface-water levels. Water is added to the standpipe to a level sufficient to drive a complete slug of water through the siphoning tube and to flush all air out of the system. The water levels in the standpipe and the water body equilibrate and provide a measurable static water surface in the standpipe. The siphon gage was designed to allow quick and accurate year-round measurements with minimal maintenance. Currently available devices for monitoring surface-water levels commonly involve time-consuming and costly installation and surveying, and the movement of reference points and the presence of ice cover in cold

  13. Differences between nipher and slter shielded rain gages at two Colorado deposition monitoring sites

    USGS Publications Warehouse

    Bigelow, David S.; Denning, A. Scott

    1990-01-01

    In the last decade the United States and Canada have made significant progress in establishing spatial ad temporal estimates of atmospheric deposition throughout North America. Fundamental to the wet-deposition portion of these estimates is the accurate and precise measurement of precipitation amount. Goodison and others (I-3) have reported on a new type of shielded snow gage known as the Canadian MSC Nipher shielded snow gage. Because this shielded snow gage has been shown to be superior to other precipitation gages for the estimation of snowfall amount, its design was adapted to the Universal Belfort precipitation gage (4), the dominant precipitation gage used at deposition monitoring sites in the United States. Favorable results taken from monitoring sites using this modified Nipher shielded snow gage (3-6) have prompted the U.S. Environmental Protection Agency and the Electric Power Research Institute to adopt the Nipher shielded Belfort gage as a standard piece of equipment in the Acid MODES and Operational Evaluation Network (OEN) monitoring programs and to propose that is be included as a standard snow gage in other North American deposition monitoring programs. This communication details preliminary results from two of nine NADP/NTN deposition monitoring sites selected by the Environmental Protection Agency to compare Nipher shielded Belfort precipitation gage volumes to volumes obtained from the standard Belfort gage used in the NADP/NTN monitoring program.

  14. Importance of Airflow for Physiologic and Ergogenic Effects of Precooling

    PubMed Central

    Morrison, Shawnda A.; Cheung, Stephen; Cotter, James D.

    2014-01-01

    Context: Cooling the body before exercise (precooling) has been studied as an ergogenic aid for many thermal conditions; however, airflow accompanying exercise is seldom reported. Objective: To determine whether the physiologic and ergogenic benefits of precooling before endurance exercise may be negated with semirealistic airflow in hot conditions. Design: Crossover study. Setting: Climate-controlled chamber in a research laboratory. Patients or Other Participants: Ten fit, healthy cyclists. Intervention(s): After a familiarization trial, participants completed 4 randomized, counterbalanced sessions consisting of no precooling versus precooling and no fan airflow versus airflow (~4.8 m/s) during exercise. Precooling was via chest-deep immersion (~24°C) for 1 hour or until core temperature dropped 0.5°C. Participants then cycled at 95% ventilatory threshold in a hot environment (temperature = 30°C, relative humidity = 50%) until volitional exhaustion, core temperature reached >39.5°C, or heart rate reached >95% of maximum. Main Outcome Measure(s): Thermal strain was assessed via core temperature (esophageal and rectal thermistors) and mean skin temperature (thermistors at 10 sites) and cardiovascular strain via heart rate and ratings of perceived exertion. Results: Endurance time (28 ± 12 minutes without precooling or airflow) increased by 30 ± 23 minutes with airflow (~109%; 95% confidence interval = 12, 45 minutes; P < .001) and by 16 ± 15 minutes with precooling (~61%; 95% confidence interval = 4, 25 minutes; P = .013), but it was not further extended when the strategies were combined (29 ± 21 minutes longer than control). During cycling without precooling or airflow, mean core and skin temperatures were higher than in all other trials. Precooling reduced heart rate by 7–11 beats/min during the first 5 minutes of exercise, but this attenuation ended by 15 minutes. Conclusions: Most laboratory-based precooling studies have (inadvertently) overestimated

  15. Evaluation of airflow patterns following procedures established by NUREG-1400.

    PubMed

    Fritz, Brad G; Khan, Fenton; Mendoza, Donaldo P

    2006-08-01

    The U.S. Nuclear Regulatory Commission's guide, NUREG-1400, addresses many aspects of air sampling in the work place. Here, we present detailed examples of the methodology used to conduct two qualitative airflow studies at different sites. In one test, smoke was used to evaluate the airflow patterns within a high-bay building for the purpose of determining appropriate locations for air monitoring equipment. The study revealed a stagnant layer of the air within the transfer area that made predicting movement of contamination within the transfer area difficult. Without conducting an airflow study, the stagnant layer may not have been identified and could have resulted in placement of samplers at inappropriate locations. In a second test, smoke was used to verify the effectiveness of an air space barrier curtain. The results showed that the curtain adequately separated the two air spaces. The methodology employed in each test provided sound, easy to interpret information that satisfied the requirements of each test. The methods described in this article can be applied at most facilities where determination of airflow patterns or the verification of suspected airflow patterns is required. PMID:16823267

  16. Resistance to forced airflow through layers of composting organic material.

    PubMed

    Teixeira, Denis Leocádio; de Matos, Antonio Teixeira; Melo, Evandro de Castro

    2015-02-01

    The objective of this study was to adjust equations to estimate the static pressure gradient of airflow through layers of organic residues submitted to two stages of biochemical degradation, and to evaluate the static pressure drop of airflow thought the material layer. Measurements of static pressure drop in the layers of sugarcane bagasse and coffee husks mixed with poultry litter on day 0 and after 30 days of composting were performed using a prototype with specific airflow rates ranging from 0.02 to 0.13 m(3) s(-1) m(-2). Static pressure gradient and specific airflow rate data were properly fit to the Shedd, Hukill & Ives and Ergun models, which may be used to predict the static pressure gradient of air to be blown through the organic residue layers. However, the Shedd model was that which best represented the phenomenon studied. The static pressure drop of airflow increased as a power of the material layer thickness and showed tendency for decreasing with the biochemical degradation time of the organic material. PMID:25536861

  17. Development of a high temperature thin film static strain gage

    NASA Astrophysics Data System (ADS)

    Hulse, Charles O.; Bailey, Richard S.; Grant, Howard P.; Przybyszewski, John S.

    1987-10-01

    The objective is to develop a new thin film resistance strain gage system which will be suitable for use inside gas turbine engines on blades or vanes at temperatures up to 1250 K. These gages are to be capable of making strain measurements to plus or minus 2000 microstrain with total errors of no more than plus or minus 10 percent during a 50 hour period. In addition to survival and stability in this hostile environment, attaining a low temperature coefficient of resistance, of the order of 20 ppm/K or less, is an important goal. This requirement arises from the presently unavoidable uncertainties in the measurement of exact temperatures inside gas turbine engines for use in making corrections for apparent strain.

  18. Alloy 600 corrosion monitor based on fiber optic strain gage

    SciTech Connect

    Berthold, J.W.; Passell, T.O.

    1996-10-01

    There is a real need to measure strain at high temperatures in many applications. For example, in nuclear steam generators that contain Alloy 600 tubing, intergranular attack (IGA) and stress corrosion cracking (SCC) are significant problems. Measuring strain in this tubing might provide an early warning of the onset of IGA/SCC and the rate of SCC progression. This report describes a method to measure the onset of IGA and the progression of SCC that occurs at a crevice on the inside surface of a tube. The measurement is accomplished by monitoring strain on the outside surface of the tube using welded, fiber-optic strain gages. In an actual application of this approach in a power plant, the strain gages must survive temperatures above 600 F for extended periods (months or years) and must provide repeatable measurements.

  19. Mapping connectivity damage in the case of Phineas Gage.

    PubMed

    Van Horn, John Darrell; Irimia, Andrei; Torgerson, Carinna M; Chambers, Micah C; Kikinis, Ron; Toga, Arthur W

    2012-01-01

    White matter (WM) mapping of the human brain using neuroimaging techniques has gained considerable interest in the neuroscience community. Using diffusion weighted (DWI) and magnetic resonance imaging (MRI), WM fiber pathways between brain regions may be systematically assessed to make inferences concerning their role in normal brain function, influence on behavior, as well as concerning the consequences of network-level brain damage. In this paper, we investigate the detailed connectomics in a noted example of severe traumatic brain injury (TBI) which has proved important to and controversial in the history of neuroscience. We model the WM damage in the notable case of Phineas P. Gage, in whom a "tamping iron" was accidentally shot through his skull and brain, resulting in profound behavioral changes. The specific effects of this injury on Mr. Gage's WM connectivity have not previously been considered in detail. Using computed tomography (CT) image data of the Gage skull in conjunction with modern anatomical MRI and diffusion imaging data obtained in contemporary right handed male subjects (aged 25-36), we computationally simulate the passage of the iron through the skull on the basis of reported and observed skull fiducial landmarks and assess the extent of cortical gray matter (GM) and WM damage. Specifically, we find that while considerable damage was, indeed, localized to the left frontal cortex, the impact on measures of network connectedness between directly affected and other brain areas was profound, widespread, and a probable contributor to both the reported acute as well as long-term behavioral changes. Yet, while significantly affecting several likely network hubs, damage to Mr. Gage's WM network may not have been more severe than expected from that of a similarly sized "average" brain lesion. These results provide new insight into the remarkable brain injury experienced by this noteworthy patient. PMID:22616011

  20. Mapping Connectivity Damage in the Case of Phineas Gage

    PubMed Central

    Van Horn, John Darrell; Irimia, Andrei; Torgerson, Carinna M.; Chambers, Micah C.; Kikinis, Ron; Toga, Arthur W.

    2012-01-01

    White matter (WM) mapping of the human brain using neuroimaging techniques has gained considerable interest in the neuroscience community. Using diffusion weighted (DWI) and magnetic resonance imaging (MRI), WM fiber pathways between brain regions may be systematically assessed to make inferences concerning their role in normal brain function, influence on behavior, as well as concerning the consequences of network-level brain damage. In this paper, we investigate the detailed connectomics in a noted example of severe traumatic brain injury (TBI) which has proved important to and controversial in the history of neuroscience. We model the WM damage in the notable case of Phineas P. Gage, in whom a “tamping iron” was accidentally shot through his skull and brain, resulting in profound behavioral changes. The specific effects of this injury on Mr. Gage's WM connectivity have not previously been considered in detail. Using computed tomography (CT) image data of the Gage skull in conjunction with modern anatomical MRI and diffusion imaging data obtained in contemporary right handed male subjects (aged 25–36), we computationally simulate the passage of the iron through the skull on the basis of reported and observed skull fiducial landmarks and assess the extent of cortical gray matter (GM) and WM damage. Specifically, we find that while considerable damage was, indeed, localized to the left frontal cortex, the impact on measures of network connectedness between directly affected and other brain areas was profound, widespread, and a probable contributor to both the reported acute as well as long-term behavioral changes. Yet, while significantly affecting several likely network hubs, damage to Mr. Gage's WM network may not have been more severe than expected from that of a similarly sized “average” brain lesion. These results provide new insight into the remarkable brain injury experienced by this noteworthy patient. PMID:22616011

  1. Cost effective stream-gaging strategies for Maine

    USGS Publications Warehouse

    Fontaine, R.A.

    1982-01-01

    This report documents the successful application of the traveling-hydrographer program developed by Moss and Gilroy to stream-gaging operations. This application was novel in the consideration of winter discharge records for the period of backwater effects due to ice. The current level of operation in Maine was identified as requiring a budget of $195,000 and having a total uncertainty of 374 cubic feet per second. Stream-gaging strategies were identified that could reduce the level of uncertainty in the system by as much as 45.8%, assuming the budgetary level remained constant. Alternately, practical stream-gaging strategies were also indentified that could reduce the total level of funding by as much as 19.2%, assuming the current level of uncertainty was deemed acceptable. Several alternatives of concurent budgeting and levels of uncertainty were identified. These relationships provide flexibility to the network manager. The results, documented in the report, were based on a sparse data base and should be applied in that context. (USGS)

  2. Parallel Computation of Airflow in the Human Lung Model

    NASA Astrophysics Data System (ADS)

    Lee, Taehun; Tawhai, Merryn; Hoffman, Eric. A.

    2005-11-01

    Parallel computations of airflow in the human lung based on domain decomposition are performed. The realistic lung model is segmented and reconstructed from CT images as part of an effort to build a normative atlas (NIH HL-04368) documenting airway geometry over 4 decades of age in healthy and disease-state adult humans. Because of the large number of the airway generation and the sheer complexity of the geometry, massively parallel computation of pulmonary airflow is carried out. We present the parallel algorithm implemented in the custom-developed characteristic-Galerkin finite element method, evaluate the speed-up and scalability of the scheme, and estimate the computing resources needed to simulate the airflow in the conducting airways of the human lungs. It is found that the special tree-like geometry enables the inter-processor communications to occur among only three or four processors for optimal parallelization irrespective of the number of processors involved in the computation.

  3. Airflow Hazard Visualization for Helicopter Pilots: Flight Simulation Study Results

    NASA Technical Reports Server (NTRS)

    Aragon, Cecilia R.; Long, Kurtis R.

    2005-01-01

    Airflow hazards such as vortices or low level wind shear have been identified as a primary contributing factor in many helicopter accidents. US Navy ships generate airwakes over their decks, creating potentially hazardous conditions for shipboard rotorcraft launch and recovery. Recent sensor developments may enable the delivery of airwake data to the cockpit, where visualizing the hazard data may improve safety and possibly extend ship/helicopter operational envelopes. A prototype flight-deck airflow hazard visualization system was implemented on a high-fidelity rotorcraft flight dynamics simulator. Experienced helicopter pilots, including pilots from all five branches of the military, participated in a usability study of the system. Data was collected both objectively from the simulator and subjectively from post-test questionnaires. Results of the data analysis are presented, demonstrating a reduction in crash rate and other trends that illustrate the potential of airflow hazard visualization to improve flight safety.

  4. Airflow studies in a forced ventilated chamber with low partitions

    SciTech Connect

    Chow, W.K.; Tsui, K.F.

    1995-12-31

    A climate chamber was used to study experimentally the airflow characteristics in a ventilated space with low partitions. Two types of commonly used air distribution devices were selected for the study--a ceiling diffuser and side grille systems. A total of 16 tests were performed using the two diffusers with partition heights varying up to 1.8 m (5.91 ft) above floor level. From the measured results, the thermal comfort indices were assessed. A stabilization effect of airflow was found when the partition height reached 1.8 m (5.91 ft). Local draft risk was located in the occupied zone. Also, the modified Archimedes number proposed by Jackman (1990) was used to describe the indoor airflow in the absence of a workable design guide for partitioned spaces.

  5. Unidirectional pulmonary airflow patterns in the savannah monitor lizard.

    PubMed

    Schachner, Emma R; Cieri, Robert L; Butler, James P; Farmer, C G

    2014-02-20

    The unidirectional airflow patterns in the lungs of birds have long been considered a unique and specialized trait associated with the oxygen demands of flying, their endothermic metabolism and unusual pulmonary architecture. However, the discovery of similar flow patterns in the lungs of crocodilians indicates that this character is probably ancestral for all archosaurs--the group that includes extant birds and crocodilians as well as their extinct relatives, such as pterosaurs and dinosaurs. Unidirectional flow in birds results from aerodynamic valves, rather than from sphincters or other physical mechanisms, and similar aerodynamic valves seem to be present in crocodilians. The anatomical and developmental similarities in the primary and secondary bronchi of birds and crocodilians suggest that these structures and airflow patterns may be homologous. The origin of this pattern is at least as old as the split between crocodilians and birds, which occurred in the Triassic period. Alternatively, this pattern of flow may be even older; this hypothesis can be tested by investigating patterns of airflow in members of the outgroup to birds and crocodilians, the Lepidosauromorpha (tuatara, lizards and snakes). Here we demonstrate region-specific unidirectional airflow in the lungs of the savannah monitor lizard (Varanus exanthematicus). The presence of unidirectional flow in the lungs of V. exanthematicus thus gives rise to two possible evolutionary scenarios: either unidirectional airflow evolved independently in archosaurs and monitor lizards, or these flow patterns are homologous in archosaurs and V. exanthematicus, having evolved only once in ancestral diapsids (the clade encompassing snakes, lizards, crocodilians and birds). If unidirectional airflow is plesiomorphic for Diapsida, this respiratory character can be reconstructed for extinct diapsids, and evolved in a small ectothermic tetrapod during the Palaeozoic era at least a hundred million years before the

  6. A Summary of Numerous Strain-Gage Load Calibrations on Aircraft Wings and Tails in a Technological Format

    NASA Technical Reports Server (NTRS)

    Jenkins, Jerald M.; DeAngelis, V. Michael

    1997-01-01

    Fifteen aircraft structures that were calibrated for flight loads using strain gages are examined. The primary purpose of this paper is to document important examples of load calibrations on airplanes during the past four decades. The emphasis is placed on studying the physical procedures of calibrating strain-gaged structures and all the supporting analyses and computational techniques that have been used. The results and experiences obtained from actual data from 14 structures (on 13 airplanes and 1 laboratory test structure) are presented. This group of structures includes fins, tails, and wings with a wide variety of aspect ratios. Straight- wing, swept-wing, and delta-wing configurations are studied. Some of the structures have skin-dominant construction; others are spar-dominant. Anisotropic materials, heat shields, corrugated components, nonorthogonal primary structures, and truss-type structures are particular characteristics that are included.

  7. Cost effectiveness of stream-gaging program in Michigan

    USGS Publications Warehouse

    Holtschlag, D.J.

    1985-01-01

    Data uses and funding sources were identified for the 129 continuous gaging stations being operated in Michigan as of 1984. One gaging station was identified as having insufficient reason to continue its operation. Several stations were identified for reactivation, should funds become available, because of insufficiencies in the data network. Alternative methods of developing streamflow information based on routing and regression analyses were investigated for 10 stations. However, no station records were reproduced with sufficient accuracy to replace conventional gaging practices. A cost-effectiveness analysis of the data collection procedure for the ice-free season was conducted using a Kalman-filter analysis. To define missing record characteristics, cross-correlation coefficients and coefficients of variation were computed at stations on the basis of daily mean discharge. Discharge measurement data were used to describe the gage/discharge rating stability at each station. The results of the cost-effectiveness analysis for a 9-month ice-free season show that the current policy of visiting most stations on a fixed servicing schedule once every 6 weeks results in an average standard error of 12.1% for the current $718,100 budget. By adopting a flexible servicing schedule, the average standard error could be reduced to 11.1%. Alternatively, the budget could be reduced to $700,200 while maintaining the current level of accuracy. A minimum budget of $680,200 is needed to operate the 129-gaging-station program; a budget less than this would not permit proper service and maintenance of stations. At the minimum budget, the average standard error would be 14.4%. A budget of $789,900 (the maximum analyzed) would result in a decrease in the average standard error to 9.07%. Owing to continual changes in the composition of the network and the changes in the uncertainties of streamflow accuracy at individual stations, the cost-effectiveness analysis will need to be updated

  8. Ultrasonic velocity meter used in stream gaging

    USGS Publications Warehouse

    Fayard, L.D.

    1991-01-01

    Many streams and canals in Florida are affected by tides or control structures and experience very low flow velocities at times. For example, the St. Johns River in northeastern Florida is affected by tides for about 140 miles upstream from its mouth and many canals in the Miami area of southeastern Florida are controlled by manmade structures and other elements that cause a variable backwater effect and very low flow velocities. For these conditions, it becomes necessary to obtain a continuous index of mean velocity as well as stage in order to compute discharge. Point-velocity sensing systems have been used to relate point velocity to mean velocity but their usefulness commonly is limited because of the lack of an exact relation. The ultrasonic velocity meter (UVM) provides an alternative approach to measuring a velocity index that can be related to mean velocity; one that provides an integrated velocity at a prescribed elevation across a stream. Six stations in the tidal-affected lower St. Johns River basin are presently equipped with UVM's. Measuring sections are as narrow as 100 feet and as wide as 900 feet. Multiple acoustic paths are used to measure wide sections in a straight reach of river; crossing paths are used to measure sections in a bend of the river. Because of low velocity and variable backwater conditions, flow also is measured with UVM's in 11 canals in the Miami area that drain into The Everglades. At some of the canal sites transducers have been permanently mounted and a 'portable' UVM module is used to obtain instantaneous velocity readings.

  9. Stress-strain gage measurements on a Nevada Test Site (NTS) event using pairs of triple foil gages

    SciTech Connect

    Kansa, E.J.; Stout, R.B.

    1990-11-30

    A triple-material stress-strain gage containing foils of ytterbium, manganin, and constantan was tested at LLNL. This gage yields three independent piezoresistance measurements from which an independent set of principal strains and principal stresses can be inferred. We have analyzed the signals from a gage at a specific location buried at a distance from the center of energy of an event at NTS. We inverted the resistivity signals to calculate the stress and strain histories as sensed by the foils. Using the elastic material properties and the traction and displacement conditions at the various material interfaces from the foils to the host geological medium, we calculated the stress and strain histories in the host geological medium. However, because of uncertainties in the elastic properties of the layers of surrounding materials, we calculated significant variations in both the peaks and signatures of the stress and strain histories that could produce the foil stress and strain histories. We conclude that, because of the inclusion problem, accurate measurements of the stress-strain histories in the host geological medium can be adequately addressed only by minimizing, as much as possible, such uncertainties.

  10. Effect of Insertion of a Heat Flux Gage into a High Temperature Cylindrical Blackbody Cavity on the Gage

    NASA Technical Reports Server (NTRS)

    Abdelmessih, Amanie N.; Horn, Thomas J.

    2007-01-01

    Detailed transient thermal models have been developed to simulate a heat flux gage calibration process capable of generating high heat flux levels. These heat flux levels are of interest to the reciprocating and gas turbine engine industries as well as the aerospace industry. The transient models are based on existing, experimentally validated steady state models of a cylindrical blackbody calibration system. The steady state models were modified to include insertion of a heat flux gage into the hot zone of the calibration system, time-varying electrical current that passes through the resistance heated blackbody, and the resulting heating of the heat flux gage. Heat fluxes computed using detailed transient models were compared to experimental measurements. The calculated and measured transient heat fluxes agreed to within 2 percent, indicating that the models had captured the physical phenomena in the transient calibration. The predicted and measured transient heat fluxes were also compared for two different blackbody configurations. The effect of convection on the blackbody extension was evaluated and found to be a minor factor.

  11. Cost-effectiveness of the U.S. Geological Survey stream-gaging program in Indiana

    USGS Publications Warehouse

    Stewart, J.A.; Miller, R.L.; Butch, G.K.

    1986-01-01

    Analysis of the stream gaging program in Indiana was divided into three phases. The first phase involved collecting information concerning the data need and the funding source for each of the 173 surface water stations in Indiana. The second phase used alternate methods to produce streamflow records at selected sites. Statistical models were used to generate stream flow data for three gaging stations. In addition, flow routing models were used at two of the sites. Daily discharges produced from models did not meet the established accuracy criteria and, therefore, these methods should not replace stream gaging procedures at those gaging stations. The third phase of the study determined the uncertainty of the rating and the error at individual gaging stations, and optimized travel routes and frequency of visits to gaging stations. The annual budget, in 1983 dollars, for operating the stream gaging program in Indiana is $823,000. The average standard error of instantaneous discharge for all continuous record gaging stations is 25.3%. A budget of $800,000 could maintain this level of accuracy if stream gaging stations were visited according to phase III results. A minimum budget of $790,000 is required to operate the gaging network. At this budget, the average standard error of instantaneous discharge would be 27.7%. A maximum budget of $1 ,000,000 was simulated in the analysis and the average standard error of instantaneous discharge was reduced to 16.8%. (Author 's abstract)

  12. Cost effectiveness of the US Geological Survey's stream-gaging program in New York

    USGS Publications Warehouse

    Wolcott, S.W.; Gannon, W.B.; Johnston, W.H.

    1986-01-01

    The U.S. Geological Survey conducted a 5-year nationwide analysis to define and document the most cost effective means of obtaining streamflow data. This report describes the stream gaging network in New York and documents the cost effectiveness of its operation; it also identifies data uses and funding sources for the 174 continuous-record stream gages currently operated (1983). Those gages as well as 189 crest-stage, stage-only, and groundwater gages are operated with a budget of $1.068 million. One gaging station was identified as having insufficient reason for continuous operation and was converted to a crest-stage gage. Current operation of the 363-station program requires a budget of $1.068 million/yr. The average standard error of estimation of continuous streamflow data is 13.4%. Results indicate that this degree of accuracy could be maintained with a budget of approximately $1.006 million if the gaging resources were redistributed among the gages. The average standard error for 174 stations was calculated for five hypothetical budgets. A minimum budget of $970,000 would be needed to operated the 363-gage program; a budget less than this does not permit proper servicing and maintenance of the gages and recorders. Under the restrictions of a minimum budget, the average standard error would be 16.0%. The maximum budget analyzed was $1.2 million, which would decrease the average standard error to 9.4%. (Author 's abstract)

  13. Study of Airflow Out of the Mouth During Speech.

    ERIC Educational Resources Information Center

    Catford, J.C.; And Others

    Airflow outside the mouth is diagnostic of articulatory activities in the vocal tract, both total volume-velocity and the distribution of particle velocities over the flow-front being useful for this purpose. A system for recording and displaying both these types of information is described. This consists of a matrix of l6 hot-wire anemometer flow…

  14. Air-flow regulation system for a coal gasifier

    DOEpatents

    Fasching, George E.

    1984-01-01

    An improved air-flow regulator for a fixed-bed coal gasifier is provided which allows close air-flow regulation from a compressor source even though the pressure variations are too rapid for a single primary control loop to respond. The improved system includes a primary controller to control a valve in the main (large) air supply line to regulate large slow changes in flow. A secondary controller is used to control a smaller, faster acting valve in a secondary (small) air supply line parallel to the main line valve to regulate rapid cyclic deviations in air flow. A low-pass filter with a time constant of from 20 to 50 seconds couples the output of the secondary controller to the input of the primary controller so that the primary controller only responds to slow changes in the air-flow rate, the faster, cyclic deviations in flow rate sensed and corrected by the secondary controller loop do not reach the primary controller due to the high frequency rejection provided by the filter. This control arrangement provides at least a factor of 5 improvement in air-flow regulation for a coal gasifier in which air is supplied by a reciprocating compressor through a surge tank.

  15. Recommended Strain Gage Application Procedures for Various Langley Research Center Balances and Test Articles

    NASA Technical Reports Server (NTRS)

    Moore, Thomas C., Sr.

    1997-01-01

    The NASA Langley Research Center uses more than 10000 strain gages per year in supporting its various research programs. The character of the testing at LaRC is such that the types of strain gage installations, the materials they are applied to, and the test environments encountered, require many varied approaches for installing strain gages. These installations must be accomplished in the most technically discerning and appropriate manner. This technical memorandum is offered as an assisting guide in helping the strain gage user to determine the appropriate approach for a given strain gage application requirement. Specifically, this document offers detailed recommendations for strain gaging the following: LaRC-Designed balances, LARC custom transducers, certain composite materials and alloys, high-temperature test articles, and selected non-typical or unique materials or test conditions.

  16. Strain gage selection and bonding techniques for application in a cryogenic-pyrotechnic environment

    NASA Astrophysics Data System (ADS)

    Law, William F.

    Strain gage tests were conducted in order to evaluate the performance of WK06-062AP-350 and weldable MG120-09-30155 gages and different combinations of bonding agent M600 and spot welding techniques in a cryogenic-pyrotechnic environment. The experimental conditions for the cryogenic-pyrotechnic shock, tension-cryogenic, and compression tests are described. The cryogenic-pyrotechnic shock test was performed to examine the strain gage bonding integrity of different installation methods; the tension-cryogenic tests evaluated strain gage ranges and temperature characteristics; and the compression tests provided data on the strain level of directly bonded and welded strain gages. The test data reveal that the WK06-062AP-350 gage and direct bonding are most applicable in a cryogenic-pyrotechnic environment.

  17. Development of strain gages for use to 1311 K (1900 F)

    NASA Technical Reports Server (NTRS)

    Lemcoe, M. M.

    1974-01-01

    A high temperature electric resistance strain gage system was developed and evaluated to 1366 K (2000 F) for periods of at least one hour. Wire fabricated from a special high temperature strain gage alloy (BCL-3), was used to fabricate the gages. Various joining techniques (NASA butt welding, pulse arc, plasma needle arc, and dc parallel gap welding) were investigated for joining gage filaments to each other, gage filaments to lead-tab ribbons, and lead-tab ribbons to lead wires. The effectiveness of a clad-wire concept as a means of minimizing apparent strain of BCL-3 strain gages was investigated by sputtering platinum coatings of varying thicknesses on wire samples and establishing the optimum coating thickness--in terms of minimum resistivity changes with temperature. Finally, the moisture-proofing effectiveness of barrier coatings subjected to elevated temperatures was studied, and one commercial barrier coating (BLH Barrier H Waterproofing) was evaluated.

  18. Practical approaches for application of resistance type strain gages on high temperature composites

    NASA Technical Reports Server (NTRS)

    Moore, Thomas C., Sr.

    1991-01-01

    Four major areas of interest with respect to utilizing strain gages on carbon/carbon (with SiC surfaces) and titanium matrix composites are addressed. Strain gage and adhesive combinations on carbon/carbon (C/C) at temperatures from minus 190 C to to 540 C, half-bridge gaging for reducing apparent strain on C/C using Poisson's ratio and bending configurations, a review of the 'field installation' techniques developed for gaging a C/C hypersonic generic elevon, and results of initial strain gaging efforts on titanium matrix composites are discussed. Current research in developing techniques for increasing the maximum temperature for strain gages on carbon/carbon are reviewed.

  19. Signal conditioning of single-active-arm strain gages used for dynamic stress measurement

    NASA Astrophysics Data System (ADS)

    Mahrenholz, B. G.

    1991-09-01

    A new strain-gage signal conditioner is described for use in the measurement of dynamic stresses on turbine engine compressor blades. This conditioner has two novel circuits. A new gage excitation circuit corrects for changes in lead-wire resistance by automatically adjusting resistances in series with the leads to the gage. This maintains a balanced configuration that offers better high-frequency common-mode rejection and less broadband noise than with constant-current excitation. Another circuit in the conditioner provides system calibration by shunting a small value resistor that is in series with the gage to produce resistance change that accurately simulates the gage resistance change. The shunting is done at a rate of 1,000 times a second to produce a 1-kHz square-wave calibration signal. The calibration circuit may be used to check on the integrity of the gage and its cabling.

  20. Palladium-chromium static strain gage for high temperature propulsion systems

    NASA Technical Reports Server (NTRS)

    Lei, Jih-Fen

    1991-01-01

    The present electrical strain gage for high temperature static strain measurements is in its fine-wire and thin-film forms designed to be temperature-compensated on any substrate material. The gage element is of Pd-Cr alloy, while the compensator is of Pt. Because the thermally-induced apparent strain of this compensated wire strain gage is sufficiently small, with good reproducibility between thermal cycles to 800 C, output figures can be corrected within a reasonable margin of error.

  1. Real-time stream gage information for smartphones

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2011-10-01

    WaterAlert, a service of the U.S. Geological Survey (USGS), sends text or e-mail messages to smartphones about rising levels of nearby rivers and streams. The service also can provide updates about groundwater levels, water temperatures, rainfall, and water quality from more than 7000 USGS real-time stream gages around the country. “WaterAlert can be used by emergency managers and the general public alike as a first alert for a developing flood,” according to Bill Werkheiser, USGS associate director for water. For more information, see http://water.usgs.gov/wateralert.

  2. Near Net Manufacturing Using Thin Gage Friction Stir Welding

    NASA Technical Reports Server (NTRS)

    Takeshita, Jennifer; Potter, David; Holquin, Michael

    2006-01-01

    Friction Stir Welding (FSW) and near net spin forming of FSW aluminumn blanks were investigated for large-scale pressure vessel applications. With a specific focus on very thin gage 2xxx and 7xxx aluminum alloys, the program concentrated on the following: the criteria used for material selection, a potential manufacturing flow, and the effectiveness and associated risks of near net spin forming. Discussion will include the mechanical properties of the friction stir welds and the parent material from before and after the spin forming process. This effort was performed under a NASA Space Exploration initiative focused on increasing the affordability, reliability and performance of pressure vessels larger than 10 ft. diameter.

  3. Zero-Gravity Vortex Vent and PVT Gaging System

    NASA Technical Reports Server (NTRS)

    Downey, M. G.; Trevathan, J. T.

    1989-01-01

    Space Station and satellite reservicing will require the ability to vent gas on orbit from liquid supply or storage tanks and to gage liquid quantity under microgravity conditions. In zero gravity, (zero-g) the vortex vent is capable of venting gas from a tank of liquid containing gas randomly distributed as bubbles. The concept uses a spinning impeller to create centrifugal force inside a vortex tube within a tank. This creates a gas pocket and forces the liquid through a venturi and back into the tank. Gas is then vented from the gas pocket through a liquid detector and then out through an exhaust port. If the liquid detector senses liquid in the vent line, the fluid is directed to the low-pressure port on the venturi and is returned to the tank. The advantages of this system is that it has no rotating seals and is compatible with most corrosive and cryogenic fluids. A prototype was designed and built at the NASA Johnson Space Center and flown on the KC-135 zero-g aircraft. During these test flights, where microgravity conditions are obtained for up to 30 sec, the prototype demonstrated that less than 0.10 percent of the volume of fluid vented was liquid when the tank was half full of liquid. The pressure volume temperature (PVT) gaging system is used in conjunction with the vortex vent to calculate the amount of liquid remaining in a tank under microgravity conditions. The PVT gaging system is used in conjunction with the vortex vent to gage liquid quantity in zero or low gravity. The system consists of a gas compressor, accumulator, and temperature and pressure instrumentation. To measure the liquid in a tank a small amount of gas is vented from the tank to the compressor and compressed into the accumulator. Pressure and temperature in the tank and accumulator are measured before and after the gas transfer occurs. Knowing the total volume of the tank, the volume of the accumulator, the volume of the intermediate lines, and initial and final pressures and

  4. Electrical properties of materials for high temperature strain gage applications

    NASA Technical Reports Server (NTRS)

    Brittain, John O.

    1989-01-01

    A study was done on the electrical resistance of materials that are potentially useful as resistance strain gages at high temperatures under static strain conditions. Initially a number of binary alloys were investigated. Later, third elements were added to these alloys, all of which were prepared by arc melting. Several transition metals were selected for experimentation, most prepared as thin films. Difficulties with electrical contacts thwarted efforts to extend measurements to the targeted 1000 C, but results obtained did suggest ways of improving the electrical resistance characteristics of certain materials.

  5. Strain Gage Measurement System to Determine Cryogenic Propellant Tank Level

    NASA Technical Reports Server (NTRS)

    Figueroa, Fernando; St.Cyr, William W.; VanDyke, David; McVay, Greg; Mitchell, Mark; Langford, Lester

    2003-01-01

    Measurement of tank level, particularly for cryogenic propellants, has proven to be a difficult proposition. Current methods based on differential pressure, capacitance sensors, temperature sensors, etc.; do not provide sufficiently accurate or robust measurements, especially at run time. This paper describes a simple, but effective method to determine propellant volume by measuring very small deformations of the structure supporting the tank. Results of a laboratory study to validate the method, and experimental data from a deployed system are presented. A comparison with an existing differential pressure sensor shows that the strain gage system provides a very good quality signal even during pressurization.

  6. Alfred P. Gage and the Introductory Physics Laboratory

    NASA Astrophysics Data System (ADS)

    Greenslade, Thomas B.

    2016-03-01

    This article is about a late 19th-century teacher of secondary school physics. I was originally interested in the apparatus that he sold. This led me to the physics books that he wrote, and these took me to his unusual ideas about ways to use laboratory time to introduce students to the phenomena of physics. More than 100 years later educational ideas have now come full circle, and it is time to bring Gage and his texts and ideas to 21st-century physics teachers.

  7. Evaluation of static and dynamic contact stresses in simulated granular particles using strain gages

    SciTech Connect

    Xu, Y.; Shukla, A. )

    1993-01-01

    The application of strain gages for the determination of static and dynamic contact loads in granular particles is demonstrated. For experimental convenience, the granular particles are simulated by circular disks fabricated from Homalite-100, a brittle polyester material. Stress field equations in the vicinity of the contact points are carefully evaluated to optimize the relative position of strain gages. The results obtained from strain gages were compared with those obtained using the optical technique of photoelasticity for both static and dynamic problems. Finally, as an example, strain gages are used to study wave propagation in a single chain assembly of disks.

  8. Cost-effectiveness of the stream-gaging program in the Hawaii District

    USGS Publications Warehouse

    Matsuoka, I.; Lee, R.; Thomas, W.O.

    1985-01-01

    This project documents the results of a study of the cost-effectiveness of the stream-gaging program in the Hawaii District. The stream gages in the District were divided into two groups, the State of Hawaii and the Other Pacific Areas. Data uses and funding sources were identified for the 124 continuous stream gages currently being operated in the Hawaii District with a budget of $570,620. All the stream-gages were identified as having sufficient reason to continue their operation and they should be maintained in the program for the foreseeable future. (USGS)

  9. Caution: API gaging practices can be hazardous to your leak resistance

    SciTech Connect

    Hill, T.H.; Money, R.C. )

    1989-10-01

    The authors address the controversy facing the OCTG inspection industry regarding how to measure pitch diameter on API round and buttress casing connections. There are two ways: the API way, using certified ring and plug gages, and a second method which uses one of a number of proprietary (non-API) gages introduced in recent years. The controversy has occurred because the new, non-API gages have revealed a bias in the accepted API ring and plug gaging method. Methods of addressing this problem are discussed.

  10. Enhanced software for the GT1022 automated gaging system. Final report

    SciTech Connect

    Hines, R.E.

    1993-09-01

    Several enhancements have been added to the gaging software of a microcomputer-controlled gaging system (GT1022) that is used to acquire and process dimensional product data from multiprobe rotary gages. Processing routines have been developed to inspect five additional feature types: dimension, least squares center, MMC position with datum diameter bonus, total indicator reading, and two-sided wall thickness. Mathematical alignment routines have been added that permit parts to be gaged in a misaligned condition and then have the measurements corrected relative to the part`s datum axes.

  11. Field manual for the collection of Navajo Nation streamflow-gage data

    USGS Publications Warehouse

    Hart, Robert J.; Fisk, Gregory G.

    2014-01-01

    The Field Manual for the Collection of Navajo Nation Streamflow-Gage Data (Navajo Field Manual) is based on established (standard) U.S. Geological Survey streamflow-gaging methods and provides guidelines specifically designed for the Navajo Department of Water Resources personnel who establish and maintain streamflow gages. The Navajo Field Manual addresses field visits, including essential field equipment and the selection of and routine visits to streamflow-gaging stations, examines surveying methods for determining peak flows (indirect measurements), discusses safety considerations, and defines basic terms.

  12. Statistical summaries of streamflow data for selected gaging stations in Idaho and adjacent states through September 1990, Volume 1: Gaging stations with 10 or more years of record

    USGS Publications Warehouse

    Kjelstrom, L.C.; Stone, M.A.J.; Harenberg, W.A.

    1996-01-01

    This volume presents statistical summaries of streamflow data for 257 gaging stations with 10 or more years of continuous record through September 1990. The gaging stations are located in Idaho and adjacent States. Streamflow statistics generated for gaging stations with 10 or more years of record were (1) magnitudes of monthly and annual flows; (2) magnitudes and frequencies of daily low, high, instantaneous peak (flood frequency), and annual mean flows; (3) duration of daily mean flows; and (4) maximum, median, and minimum daily mean flows.

  13. Scale dependence of rock mass deformability measured by fiber-optic strain gages

    NASA Astrophysics Data System (ADS)

    Gage, JoAnn R.

    We use fiber-optic strain and temperature sensors to measure in situ strain in rock masses to examine how the mechanical properties of rock vary from the cm3 to m3-scale. We have installed a dense array of Fiber Bragg Grating (FBG) sensors underground on the 1250 m (4100 ft.) level of the Sanford Underground Research Facility (SURF) Lead, SD. We use this sensor array in two loading experiments to determine the modulus of deformation (Em) of the rock mass. We have developed three sensor attachment methods. We use 1 m gage-length OS3600 temperature-compensated FBG strain gages that were installed in two ways: surface-mounted and embedded. Ambient temperature changes in the mine bias strain measurements from the surface-mounted sensors. Because of the temperature effects on the surface-mounted sensors, embedded sensors are preferable for measuring in situ strain in rock masses. In order to measure a more detailed strain and temperature profile within a rock mass, we have developed Fiber-optically Instrumented Rock Strain and Temperature Strips (FROSTS). FROSTS are embedded in the rock mass and have six fiber-optic strain and temperature gages installed along specially designed strips of 304-stainless steel. We have also developed a pretensioning method for the FROSTS so that the FROSTS can measure both shortening and elongation. Our laboratory experiments show that the FROSTS accurately measure strain, are more compliant than the rock mass, and thoroughly couple to the rock mass. We performed two field point-loading tests using 89 kN and 890 kN loads and the fiber-optic strain sensors array to evaluate in situ rock mass deformability and examine how the mechanical properties of rock vary over spatial scales. The in situ modulus of deformation increases with depth into the rock mass. We interpret this increase in stiffness to be a result of the differences in mechanical properties due to the effect of excavation of the underground space. If done properly, in situ

  14. Rainfall, streamflow, and peak stage data collected at the Murfreesboro, Tennessee, gaging network, March 1989 through July 1992

    USGS Publications Warehouse

    Outlaw, G.S.; Butner, D.E.; Kemp, R.L.; Oaks, A.T.; Adams, G.S.

    1992-01-01

    Rainfall, stage, and streamflow data in the Murfreesboro area, Middle Tennessee, were collected from March 1989 through July 1992 from a network of 68 gaging stations. The network consists of 10 tipping-bucket rain gages, 2 continuous-record streamflow gages, 4 partial-record flood hydrograph gages, and 72 crest-stage gages. Data collected by the gages includes 5minute time-step rainfall hyetographs, 15-minute time-step flood hydrographs, and peak-stage elevations. Data are stored in a computer data base and are available for many computer modeling and engineering applications.

  15. Scanning LDV for vibration measurement of filiform hairs in crickets in response to induced airflow

    NASA Astrophysics Data System (ADS)

    Santulli, C.; Finn, T. J.; Seidel, R.; Jeronimidis, G.

    2006-06-01

    Cercal hairs represent in cricket a wind sensitive escape system, able to detect the airflow generated from predating species. These sensors have been studied as a biomimetic concept to allow the development of MEMS for biomedical use. In particular, the behaviour of the hairs, including airflow response, resonant frequency and damping, has been investigated up to a frequency of 20 kHz. The microscopic nature of the hairs, the complex vibrations of excited hairs and the high damping of the system suggested that the use of Laser Doppler vibrometry could possibly improve the test performance. Two types of tests were performed: in the first case the hairs were indirectly excited using the signal obtained from a vibrating aluminium plate, whilst in the second case the hairs were directly excited using a white noise chirp. The results from the first experiment indicated that the hairs move in-phase with the exciting signal up to frequencies in the order of 10 kHz, responding to the vibration modes of the plate with a signal attenuation of 12 to 20 dB. The chirp experiment revealed the presence of rotational resonant modes at 6850 and 11300 Hz. No clear effect of hair length was perceivable on the vibration response of the filiform sensors. The obtained results proved promising to support the mechanical and vibration characterisation of the hairs and suggest that scanning Laser vibrometry can be used extensively on highly dampened biological materials.

  16. Computational Investigation of Dynamic Glottal Aperture Effects on Respiratory Airflow

    NASA Astrophysics Data System (ADS)

    Xi, Jinxiang; Yan, Hong; Dong, Haibo

    2008-11-01

    The periodic movement of the glottal aperture (vocal folds) during tidal breathing has been long recognized as a factor in altering the airflow dynamics in the tracheobrnchial region. The potential influence from these altered flow structures on the transport and deposition of inhaled particles is not known. However, studies devoted to this dynamic physiological feature are scarce due to the complex anatomy in of the larynx and numerical challenges in simulating dynamic geometries. In this study, a high-fidelity immersed boundary solver is used to investigate this problem. A 3D human oral-larynx-lung model is firstly reconstructed from MRI data. The role of the vocal fold movement and associated airflow characteristics such as vortex shedding, Coanda effect etc. during inhalation and exhalation are then numerically studied.

  17. Airflow and Particle Transport in the Human Respiratory System

    NASA Astrophysics Data System (ADS)

    Kleinstreuer, C.; Zhang, Z.

    2010-01-01

    Airflows in the nasal cavities and oral airways are rather complex, possibly featuring a transition to turbulent jet-like flow, recirculating flow, Dean's flow, vortical flows, large pressure drops, prevailing secondary flows, and merging streams in the case of exhalation. Such complex flows propagate subsequently into the tracheobronchial airways. The underlying assumptions for particle transport and deposition are that the aerosols are spherical, noninteracting, and monodisperse and deposit upon contact with the airway surface. Such dilute particle suspensions are typically modeled with the Euler-Lagrange approach for micron particles and in the Euler-Euler framework for nanoparticles. Micron particles deposit nonuniformly with very high concentrations at some local sites (e.g., carinal ridges of large bronchial airways). In contrast, nanomaterial almost coats the airway surfaces, which has implications of detrimental health effects in the case of inhaled toxic nanoparticles. Geometric airway features, as well as histories of airflow fields and particle distributions, may significantly affect particle deposition.

  18. Efficient airflow design for cleanrooms improves business bottom lines

    SciTech Connect

    Xu, Tengfang

    2003-01-05

    Based on a review of airflow design factors and in-situ energy measurements in ISO Cleanliness Class-5 cleanrooms, this paper addresses the importance of energy efficiency in airflow design and opportunities of cost savings in cleanroom practices. The paper discusses design factors that can long lastingly affect cleanroom system performance, and demonstrates benefits of energy efficient cleanroom design from viewpoints of environmental control and business operations. The paper suggests that a high performance cleanroom should not only be effective in contamination control, but also be efficient in energy and environmental performance. The paper also suggests that energy efficient design practice stands to bring in immediate capital cost savings and operation cost savings, and should be regarded by management as a strategy to improve business bottom lines.

  19. Air Trapping and Airflow Obstruction in Newborn Cystic Fibrosis Piglets

    PubMed Central

    Adam, Ryan J.; Michalski, Andrew S.; Bauer, Christian; Abou Alaiwa, Mahmoud H.; Gross, Thomas J.; Awadalla, Maged S.; Bouzek, Drake C.; Gansemer, Nicholas D.; Taft, Peter J.; Hoegger, Mark J.; Diwakar, Amit; Ochs, Matthias; Reinhardt, Joseph M.; Hoffman, Eric A.; Beichel, Reinhard R.; Meyerholz, David K.

    2013-01-01

    Rationale: Air trapping and airflow obstruction are being increasingly identified in infants with cystic fibrosis. These findings are commonly attributed to airway infection, inflammation, and mucus buildup. Objectives: To learn if air trapping and airflow obstruction are present before the onset of airway infection and inflammation in cystic fibrosis. Methods: On the day they are born, piglets with cystic fibrosis lack airway infection and inflammation. Therefore, we used newborn wild-type piglets and piglets with cystic fibrosis to assess air trapping, airway size, and lung volume with inspiratory and expiratory X-ray computed tomography scans. Micro–computed tomography scanning was used to assess more distal airway sizes. Airway resistance was determined with a mechanical ventilator. Mean linear intercept and alveolar surface area were determined using stereologic methods. Measurements and Main Results: On the day they were born, piglets with cystic fibrosis exhibited air trapping more frequently than wild-type piglets (75% vs. 12.5%, respectively). Moreover, newborn piglets with cystic fibrosis had increased airway resistance that was accompanied by luminal size reduction in the trachea, mainstem bronchi, and proximal airways. In contrast, mean linear intercept length, alveolar surface area, and lung volume were similar between both genotypes. Conclusions: The presence of air trapping, airflow obstruction, and airway size reduction in newborn piglets with cystic fibrosis before the onset of airway infection, inflammation, and mucus accumulation indicates that cystic fibrosis impacts airway development. Our findings suggest that early airflow obstruction and air trapping in infants with cystic fibrosis might, in part, be caused by congenital airway abnormalities. PMID:24168209

  20. Airflow pattern complexity and airway obstruction in asthma.

    PubMed

    Veiga, Juliana; Lopes, Agnaldo J; Jansen, José M; Melo, Pedro L

    2011-08-01

    The scientific and clinical value of a measure of complexity is potentially enormous because complexity appears to be lost in the presence of illness. The authors examined the effect of elevated airway obstruction on the complexity of the airflow (Q) pattern of asthmatic patients analyzing the airflow approximate entropy (ApEnQ). This study involved 11 healthy controls, 11 asthmatics with normal spirometric exams, and 40 asthmatics with mild (14), moderate (14), and severe (12) airway obstructions. A significant (P < 0.02) reduction in the ApEnQ was observed in the asthmatic patients. This reduction was significantly correlated with spirometric indexes of airway obstruction [FEV(1) (%): R = 0.31, P = 0.013] and the total respiratory impedance (R = -0.39; P < 0.002). These results are in close agreement with pathophysiological fundamentals and suggest that the airflow pattern becomes less complex in asthmatic patients, which may reduce the adaptability of the respiratory system to perform the exercise that is associated with daily life activities. This analysis was able to identify respiratory changes in patients with mild obstruction with an adequate accuracy (83%). Higher accuracies were obtained in patients with moderate and severe obstructions. The analysis of airflow pattern complexity by the ApEnQ was able to provide new information concerning the changes associated with asthma. In addition, this analysis was also able to contribute to the detection of the adverse effects of asthma. Because these measurements are easy to perform, such a technique may represent an alternative and/or a complement to other conventional exams to help the clinical evaluations of asthmatic patients. PMID:21565988

  1. Cost effectiveness of the US Geological Survey's stream-gaging programs in New Hampshire and Vermont

    USGS Publications Warehouse

    Smath, J.A.; Blackey, F.E.

    1986-01-01

    Data uses and funding sources were identified for the 73 continuous stream gages currently (1984) being operated. Eight stream gages were identified as having insufficient reason to continue their operation. Parts of New Hampshire and Vermont were identified as needing additional hydrologic data. New gages should be established in these regions as funds become available. Alternative methods for providing hydrologic data at the stream gaging stations currently being operated were found to lack the accuracy that is required for their intended use. The current policy for operation of the stream gages requires a net budget of $297,000/yr. The average standard error of estimation of the streamflow records is 17.9%. This overall level of accuracy could be maintained with a budget of $285,000 if resources were redistributed among gages. Cost-effective analysis indicates that with the present budget, the average standard error could be reduced to 16.6%. A minimum budget of $278,000 is required to operate the present stream gaging program. Below this level, the gages and recorders would not receive the proper service and maintenance. At the minimum budget, the average standard error would be 20.4%. The loss of correlative data is a significant component of the error in streamflow records, especially at lower budgetary levels. (Author 's abstract)

  2. Matilda Joslyn Gage: A Nineteenth-Century Women's Rights Historian Looks at Witchcraft.

    ERIC Educational Resources Information Center

    Corey, Mary E.

    2003-01-01

    Explores the ideas of the nineteenth century female historian, Matilda Joslyn Gage, who authored the book, "Woman, Church, and State." Focuses on Gage's ideas about women's history, particularly related to the role of the church and women persecuted for witchcraft. (CMK)

  3. Use of encapsulated high-temperature strain gages at temperatures up to 315 C

    SciTech Connect

    Hofstoetter, P.

    1985-08-01

    An account is given of the use of two types of encapsulated strain gage to measure strains in West Germany nuclear power stations during start up and service. Gage calibration was performed using a clamping device rather than spot welding. Of the two types of encapsulated strain gages available for measurement up to 315 C, one is a quarter-bridge gage with an NiCr measuring element; the other is a half-bridge gage with a PtW measuring element. Factors considered were: apparent strain, zero shift, change of apparent strain, creep and lifetime. It is recommended that NiCr gages be used for static measurements up to about 260 C only. For temperatures higher than 260 degrees, PtW strain gages must be used; these seem to be much more stable at temperatures of 260-315 C. Tests are under way to determine the maximum temperature for these gages; all that is certain now is that they fail at 530 C when the cables separate. 6 references.

  4. Three-Dimensional Numerical Simulation of Airflow in Nasopharynx.

    NASA Astrophysics Data System (ADS)

    Shome, Biswadip; Wang, Lian-Ping; Santare, Michael H.; Szeri, Andras Z.; Prasad, Ajay K.; Roberts, David

    1996-11-01

    A three-dimensional numerical simulation of airflow in nasopharynx (from the soft palate to the epiglottis) was conducted, using anatomically accurate model and finite element method, to study the influence of flow characteristics on obstructive sleep apnea (OSA). The results showed that the pressure drop in the nasopharynx is in the range 200-500 Pa. Ten different nasopharynx geometries resulting from three OSA treatment therapies (CPAP, mandibular repositioning devices, and surgery) were compared. The results confirmed that the airflow in the nasopharynx lies in the transitional flow regime and thus, a subtle change in the morphology caused by these treatment therapies has a large effect on the airflow. The onset of turbulence can cause as much as 40% of increase in pressure drop. For the transitional flow regime, the k-ɛ turbulence model was found to be the most appropriate model, when compared to the mixing length and the k-ω model, as it correctly reproduces the limiting laminar behavior. In addition, the pressure drop increased approximately as the square of the volumetric flow rate. Supported by NIH.

  5. Airflow Simulations around OA Intake Louver with Electronic Velocity Sensors

    SciTech Connect

    Han, Hwataik; Sullivan, Douglas P.; Fisk, William J.

    2009-04-01

    It is important to control outdoor airflow rates into HVAC systems in terms of energy conservation and healthy indoor environment. Technologies are being developed to measure outdoor air (OA) flow rates through OA intake louvers on a real time basis. The purpose of this paper is to investigate the airflow characteristics through an OA intake louver numerically in order to provide suggestions for sensor installations. Airflow patterns are simulated with and without electronic air velocity sensors within cylindrical probes installed between louver blades or at the downstream face of the louver. Numerical results show quite good agreements with experimental data, and provide insights regarding measurement system design. The simulations indicate that velocity profiles are more spatially uniform at the louver outlet relative to between louver blades, that pressure drops imposed by the sensor bars are smaller with sensor bars at the louver outlet, and that placement of the sensor bars between louver blades substantially increases air velocities inside the louver. These findings suggest there is an advantage to placing the sensor bars at the louver outlet face.

  6. Realistic glottal motion and airflow rate during human breathing.

    PubMed

    Scheinherr, Adam; Bailly, Lucie; Boiron, Olivier; Lagier, Aude; Legou, Thierry; Pichelin, Marine; Caillibotte, Georges; Giovanni, Antoine

    2015-09-01

    The glottal geometry is a key factor in the aerosol delivery efficiency for treatment of lung diseases. However, while glottal vibrations were extensively studied during human phonation, the realistic glottal motion during breathing is poorly understood. Therefore, most current studies assume an idealized steady glottis in the context of respiratory dynamics, and thus neglect the flow unsteadiness related to this motion. This is particularly important to assess the aerosol transport mechanisms in upper airways. This article presents a clinical study conducted on 20 volunteers, to examine the realistic glottal motion during several breathing tasks. Nasofibroscopy was used to investigate the glottal geometrical variations simultaneously with accurate airflow rate measurements. In total, 144 breathing sequences of 30s were recorded. Regarding the whole database, two cases of glottal time-variations were found: "static" or "dynamic" ones. Typically, the peak value of glottal area during slow breathing narrowed from 217 ± 54 mm(2) (mean ± STD) during inspiration, to 178 ± 35 mm(2) during expiration. Considering flow unsteadiness, it is shown that the harmonic approximation of the airflow rate underevaluates the inertial effects as compared to realistic patterns, especially at the onset of the breathing cycle. These measurements provide input data to conduct realistic numerical simulations of laryngeal airflow and particle deposition. PMID:26159687

  7. Field measurement of uncontrolled airflow and depressurization in restaurants

    SciTech Connect

    Cummings, J.B.; Fairey, P.W.; Withers, C.R. Jr.; McKendry, B.B.; Moyer, N.A.

    1996-11-01

    Field investigations were done in seven restaurants (subsample of a study of 63 commercial buildings) to identify uncontrolled airflows and pressure imbalances. Testing included building airtightness tests, identification of building air barrier locations, duct system airtightness, characterization of pressure differentials, building airflow balance, and infiltration/ventilation rates. All restaurants were found to operate at negative pressures that ranged from {minus}0.003 in. w.c. ({minus}0.8 Pa) to {minus}0.173 in. w.c. ({minus}43 Pa) and averaged {minus}0.051 in. w.c. ({minus}12.7 Pa) under normal operation. The variables that affect depressurization are large exhaust fans, missing or undersized make up air, intermittent outdoor air caused by the cycling of air handlers, dirty outdoor air and make up air filters, and building airtightness. These uncontrolled airflows and pressure imbalances impact energy use, ventilation rates, sizing of heating and air-conditioning systems, indoor comfort, relative humidity, moisture damage to building materials, mold and mildew growth, operation of combustion equipment, and indoor air quality.

  8. Energy Harvesting from Human Motion Using Footstep-Induced Airflow

    NASA Astrophysics Data System (ADS)

    Fu, H.; Xu, R.; Seto, K.; Yeatman, E. M.; Kim, S. G.

    2015-12-01

    This paper presents an unobtrusive in-shoe energy harvester converting foot-strike energy into electricity to power wearable or portable devices. An air-pumped turbine system is developed to address the issues of the limited vertical deformation of shoes and the low frequency of human motion that impede harvesting energy from this source. The air pump is employed to convert the vertical foot-strike motion into airflow. The generated airflow passes through the miniaturized wind turbine whose transduction is realized by an electromagnetic generator. Energy is extracted from the generator with a higher frequency than that of footsteps, boosting the output power of the device. The turbine casing is specifically designed to enable the device to operate continuously with airflow in both directions. A prototype was fabricated and then tested under different situations. A 6 mW peak power output was obtained with a 4.9 Ω load. The achievable power from this design was estimated theoretically for understanding and further improvement.

  9. Cost effectiveness of the U.S. Geological Survey's stream-gaging program in Illinois

    USGS Publications Warehouse

    Mades, D.M.; Oberg, K.A.

    1984-01-01

    Data uses and funding sources were identified for 138 continuous-record discharge-gaging stations currently (1983) operated as part of the stream-gaging program in Illinois. Streamflow data from five of those stations are used only for regional hydrology studies. Most streamflow data are used for defining regional hydrology, defining rainfall-runoff relations, flood forecasting, regulating navigation systems, and water-quality sampling. Based on the evaluations of data use and of alternative methods for determining streamflow in place of stream gaging, no stations in the 1983 stream-gaging program should be deactivated. The current budget (in 1983 dollars) for operating the 138-station program is $768,000 per year. The average standard error of instantaneous discharge for the current practice for visiting the gaging stations is 36.5 percent. Missing stage record accounts for one-third of the 36.5 percent average standard error. (USGS)

  10. Response of hot element wall shear stress gages in laminar oscillating flows

    NASA Technical Reports Server (NTRS)

    Cook, W. J.; Murphy, J. D.; Giddings, T. A.

    1986-01-01

    An experimental investigation of the time-dependent response of hot element wall shear stress gages in unsteady periodic air flows is reported. The study has focused on wall shear stress in laminar oscillating flows produced on a flat plate by a free stream velocity composed of a mean component and a superposed sinusoidal variation. Two types of hot element gages, platinum film and flush wire, were tested for values of reduced frequency ranging from 0.14 to 2.36. Values of the phase angle of the wall shear stress variation relative to the free stream velocity, as indicated by the hot element gages, are compared with numerical prediction. The comparisons show that the gages indicate a wall shear stress variation that lags the true variation, and that the gages will also not indicate the correct wall shear stress variation in periodic turbulent flows.

  11. Single-strain-gage force/stiffness buckling prediction techniques on a hat-stiffened panel

    NASA Technical Reports Server (NTRS)

    Hudson, Larry D.; Thompson, Randolph C.

    1991-01-01

    Predicting the buckling characteristics of a test panel is necessary to ensure panel integrity during a test program. A single-strain-gage buckling prediction method was developed on a hat-stiffened, monolithic titanium buckling panel. The method is an adaptation of the original force/stiffness method which requires back-to-back gages. The single-gage method was developed because the test panel did not have back-to-back gages. The method was used to predict buckling loads and temperatures under various heating and loading conditions. The results correlated well with a finite element buckling analysis. The single-gage force/stiffness method was a valid real-time and post-test buckling prediction technique.

  12. Eyelashes divert airflow to protect the eye.

    PubMed

    Amador, Guillermo J; Mao, Wenbin; DeMercurio, Peter; Montero, Carmen; Clewis, Joel; Alexeev, Alexander; Hu, David L

    2015-04-01

    Eyelashes are ubiquitous, although their function has long remained a mystery. In this study, we elucidate the aerodynamic benefits of eyelashes. Through anatomical measurements, we find that 22 species of mammals possess eyelashes of a length one-third the eye width. Wind tunnel experiments confirm that this optimal eyelash length reduces both deposition of airborne particles and evaporation of the tear film by a factor of two. Using scaling theory, we find this optimum arises because of the incoming flow's interactions with both the eye and eyelashes. Short eyelashes create a stagnation zone above the ocular surface that thickens the boundary layer, causing shear stress to decrease with increasing eyelash length. Long eyelashes channel flow towards the ocular surface, causing shear stress to increase with increasing eyelash length. These competing effects result in a minimum shear stress for intermediate eyelash lengths. This design may be employed in creating eyelash-inspired protection for optical sensors. PMID:25716186

  13. Eyelashes divert airflow to protect the eye

    PubMed Central

    Amador, Guillermo J.; Mao, Wenbin; DeMercurio, Peter; Montero, Carmen; Clewis, Joel; Alexeev, Alexander; Hu, David L.

    2015-01-01

    Eyelashes are ubiquitous, although their function has long remained a mystery. In this study, we elucidate the aerodynamic benefits of eyelashes. Through anatomical measurements, we find that 22 species of mammals possess eyelashes of a length one-third the eye width. Wind tunnel experiments confirm that this optimal eyelash length reduces both deposition of airborne particles and evaporation of the tear film by a factor of two. Using scaling theory, we find this optimum arises because of the incoming flow's interactions with both the eye and eyelashes. Short eyelashes create a stagnation zone above the ocular surface that thickens the boundary layer, causing shear stress to decrease with increasing eyelash length. Long eyelashes channel flow towards the ocular surface, causing shear stress to increase with increasing eyelash length. These competing effects result in a minimum shear stress for intermediate eyelash lengths. This design may be employed in creating eyelash-inspired protection for optical sensors. PMID:25716186

  14. Airflow calibration of a bellmouth inlet for measurement of compressor airflow in turbine-powered propulsion simulators

    NASA Technical Reports Server (NTRS)

    Smith, S. C.

    1985-01-01

    The development of turbine-powered propulsion simulators for high-speed wind tunnel models requires a bellmouth inlet which can accurately measure compressor-inlet airflow. A bellmouth inlet was instrumented with total pressure probes, static pressure probes, and thermocouples for airflow measurement. The bellmouth flowmeter against a critical venturi flowmeter was calibrated. The calibration was done at four inlet pressures ranging from 58 to 114 kPa. The bellmouth discharge coefficient varied as a function of bellmouth-throat Mach number. Over the range of Reynolds number and Mach number tested the Reynolds number was not a significant influence on the discharge coefficient. The overall accuracy of the bellmouth inlet as a flowmeter was estimated to be + or - 0.5% of the flowmeter reading.

  15. Effects of surface roughness on evaporation from porous surfaces into turbulent airflows

    NASA Astrophysics Data System (ADS)

    Haghighi, Erfan; Or, Dani

    2014-05-01

    The ubiquitous and energy intensive mass transfer between wet porous surfaces and turbulent airflows is of great importance for various natural and industrial applications. The roughness of natural surfaces is likely to influence the structure of adjacent boundary layer and thus affecting heat and mass fluxes from surfaces. These links were formalized in a new model that considers the intermittent turbulence-induced boundary layer with local mass and energy exchange rates. We conducted experiments with regular surface roughness patterns subjected to constant turbulent airflows and monitored mass loss and thermal signatures of localized evaporative fluxes using infrared thermography. The resulting patterns were in good agreement with model predictions for local and surface averaged turbulent exchange rates. Preliminary results obtained for evaporation from sinusoidal wavy soil surfaces reveal that evaporative fluxes can be either enhanced or suppressed (relative to a flat surface) owing to relative contribution of downstream (separation zone) and rising (reattachment zone) surfaces of the wave with thick and thin viscous sublayer thicknesses, respectively. For isolated roughness elements (bluff bodies) over a flat evaporating surface, the resulting fluxes are enhanced (relative to a smooth surface) due to formation of vortices that induce thinner boundary layer. Potential benefits of the study for interpretation and upscaling of evaporative and heat fluxes from natural (rough) terrestrial surfaces will be discussed. Keywords: Turbulent Evaporation, Porous Media, Surface Roughness, Infrared Thermography.

  16. Collective odor source estimation and search in time-variant airflow environments using mobile robots.

    PubMed

    Meng, Qing-Hao; Yang, Wei-Xing; Wang, Yang; Zeng, Ming

    2011-01-01

    This paper addresses the collective odor source localization (OSL) problem in a time-varying airflow environment using mobile robots. A novel OSL methodology which combines odor-source probability estimation and multiple robots' search is proposed. The estimation phase consists of two steps: firstly, the separate probability-distribution map of odor source is estimated via Bayesian rules and fuzzy inference based on a single robot's detection events; secondly, the separate maps estimated by different robots at different times are fused into a combined map by way of distance based superposition. The multi-robot search behaviors are coordinated via a particle swarm optimization algorithm, where the estimated odor-source probability distribution is used to express the fitness functions. In the process of OSL, the estimation phase provides the prior knowledge for the searching while the searching verifies the estimation results, and both phases are implemented iteratively. The results of simulations for large-scale advection-diffusion plume environments and experiments using real robots in an indoor airflow environment validate the feasibility and robustness of the proposed OSL method. PMID:22346650

  17. Collective Odor Source Estimation and Search in Time-Variant Airflow Environments Using Mobile Robots

    PubMed Central

    Meng, Qing-Hao; Yang, Wei-Xing; Wang, Yang; Zeng, Ming

    2011-01-01

    This paper addresses the collective odor source localization (OSL) problem in a time-varying airflow environment using mobile robots. A novel OSL methodology which combines odor-source probability estimation and multiple robots’ search is proposed. The estimation phase consists of two steps: firstly, the separate probability-distribution map of odor source is estimated via Bayesian rules and fuzzy inference based on a single robot’s detection events; secondly, the separate maps estimated by different robots at different times are fused into a combined map by way of distance based superposition. The multi-robot search behaviors are coordinated via a particle swarm optimization algorithm, where the estimated odor-source probability distribution is used to express the fitness functions. In the process of OSL, the estimation phase provides the prior knowledge for the searching while the searching verifies the estimation results, and both phases are implemented iteratively. The results of simulations for large-scale advection–diffusion plume environments and experiments using real robots in an indoor airflow environment validate the feasibility and robustness of the proposed OSL method. PMID:22346650

  18. Influence of Primary Gage Sensitivities on the Convergence of Balance Load Iterations

    NASA Technical Reports Server (NTRS)

    Ulbrich, Norbert Manfred

    2012-01-01

    The connection between the convergence of wind tunnel balance load iterations and the existence of the primary gage sensitivities of a balance is discussed. First, basic elements of two load iteration equations that the iterative method uses in combination with results of a calibration data analysis for the prediction of balance loads are reviewed. Then, the connection between the primary gage sensitivities, the load format, the gage output format, and the convergence characteristics of the load iteration equation choices is investigated. A new criterion is also introduced that may be used to objectively determine if the primary gage sensitivity of a balance gage exists. Then, it is shown that both load iteration equations will converge as long as a suitable regression model is used for the analysis of the balance calibration data, the combined influence of non linear terms of the regression model is very small, and the primary gage sensitivities of all balance gages exist. The last requirement is fulfilled, e.g., if force balance calibration data is analyzed in force balance format. Finally, it is demonstrated that only one of the two load iteration equation choices, i.e., the iteration equation used by the primary load iteration method, converges if one or more primary gage sensitivities are missing. This situation may occur, e.g., if force balance calibration data is analyzed in direct read format using the original gage outputs. Data from the calibration of a six component force balance is used to illustrate the connection between the convergence of the load iteration equation choices and the existence of the primary gage sensitivities.

  19. High temperature static strain gage alloy development program

    NASA Technical Reports Server (NTRS)

    Hulse, C. O.; Bailey, R. S.; Lemkey, F. D.

    1985-01-01

    The literature, applicable theory and finally an experimental program were used to identify new candidate alloy systems for use as the electrical resistance elements in static strain gages up to 1250K. The program goals were 50 hours of use in the environment of a test stand gas turbine engine with measurement accuracies equal to or better than 10 percent of full scale for strains up to + or - 2000 microstrain. As part of this effort, a computerized electrical resistance measurement system was constructed for use at temperatures between 300K and 1250K and heating and cooling rates of 250K/min and 10K/min. The two best alloys were an iron-chromium-aluminum alloy and a palladium base alloy. Although significant progress was made, it was concluded that a considerable additional effort would be needed to fully optimize and evaluate these candidate systems.

  20. Comparison of current meters used for stream gaging

    USGS Publications Warehouse

    Fulford, Janice M.; Thibodeaux, Kirk G.; Kaehrle, William R.

    1994-01-01

    The U.S. Geological Survey (USGS) is field and laboratory testing the performance of several current meters used throughout the world for stream gaging. Meters tested include horizontal-axis current meters from Germany, the United Kingdom, and the People's Republic of China, and vertical-axis and electromagnetic current meters from the United States. Summarized are laboratory test results for meter repeatability, linearity, and response to oblique flow angles and preliminary field testing results. All current meters tested were found to under- and over-register velocities; errors usually increased as the velocity and angle of the flow increased. Repeatability and linearity of all meters tested were good. In the field tests, horizontal-axis meters, except for the two meters from the People's Republic of China, registered higher velocity than did the vertical-axis meters.

  1. An evaluation of Idaho stream-gaging networks

    USGS Publications Warehouse

    Quillian, E.W.; Harenberg, W.A.

    1982-01-01

    Network Analysis for Regional Information (NARI) and the Cost-Effectiveness Procedure were tested by applying them to stream-gaging networks in Idaho. NARI was used to determine network design strategies that would maximize the value of additional data. Value of data was measured as the decrease in the probable true standards error of regional regression equations. NARI indicated that no significant decrease in regression error can be achieved by the collection of additional data and that better models should be sought. No major modifications to NARI are necessary to make it widely applicable. The Cost-Effectiveness Procedure was used to determine optimal network operation strategies. It showed network uncertainty can be reduced when six- or one-visit per year minimum constraints are in force. Sensitivity to various cost factors was examined. Attempts to model networks that included sites for collection of groundwater and water-quality data were unsuccessful. (USGS)

  2. Durability investigation of a group of strain gage pressure transducers

    NASA Technical Reports Server (NTRS)

    Lederer, P. S.; Hilten, J. S.

    1972-01-01

    A durability investigation was conducted on a group of eighteen bonded-wire strain gage pressure transducers with ranges of 0 to 15 psig and 0 to 100 psig using an improved version of a previously developed technique. Some of the transducers were subjected to 40 million pressure cycles at a 5-Hz rate at laboratory ambient conditions, others were cycled at a temperature of 150 F (65.6 C). The largest change in sensitivity observed was 0.22% for a 100-psig transducer subjected to 40 million pressure cycles at 150 F. The largest change in zero pressure output observed was 0.91% FS for the same transducer. None of the transducers failed completely as a result of cycling at or below full scale pressure.

  3. Strain gage sting balance 204-6. Calibration report

    NASA Astrophysics Data System (ADS)

    Blaettler, Heinz

    1986-12-01

    The strain gage sting balance 204-6 was developed for aerodynamic measurements on rocket models in the transonic and supersonic wind tunnel. Data are: X = +/- 50 (N); Y = +/- 150 (N); Z = +/- 400 (N); Mx = +/- 1.5 (Nm); My = +/- 20 (Nm); and Mz = +/- 10 (Nm). Compared to the existing balances of same size the ratio Y/Z is changed from 1:8 to 1:3.75. This change of specifications was introduced with regard to measurements to be taken with a sting providing automatic roll positioning around the X-axis. The resistance module was separately constructed and prestressed by a factor of 0.5, and connected to the model and sting part of the balance by electron-beam welding.

  4. Direct measurements of wall shear stress by buried wire gages in a shock-wave boundary-layer interaction region

    NASA Technical Reports Server (NTRS)

    Murthy, V. S.; Rose, W. C.

    1977-01-01

    Detailed measurements of wall shear stress (skin friction) were made with specially developed buried wire gages in the interaction regions of a Mach 2.9 turbulent boundary layer with externally generated shocks. Separation and reattachment points inferred by these measurements support the findings of earlier experiments which used a surface oil flow technique and pitot profile measurements. The measurements further indicate that the boundary layer tends to attain significantly higher skin-friction values downstream of the interaction region as compared to upstream. Comparisons between measured wall shear stress and published results of some theoretical calculation schemes show that the general, but not detailed, behavior is predicted well by such schemes.

  5. Influence of liquid-volume and airflow rates on spray application quality and homogeneity in super-intensive olive tree canopies.

    PubMed

    Miranda-Fuentes, Antonio; Rodríguez-Lizana, Antonio; Gil, Emilio; Agüera-Vega, J; Gil-Ribes, Jesús A

    2015-12-15

    Olive is a key crop in Europe, especially in countries around the Mediterranean Basin. Optimising the parameters of a spray is essential for sustainable pesticide use, especially in high-input systems, such as the super-intensive hedgerow system. Parameters may be optimised by adjusting the applied volume and airflow rate of sprays, in addition to the liquid to air proportion and the relationship between air velocity and airflow rate. Two spray experiments using a commercial airblast sprayer were conducted in a super-intensive orchard to study how varying the liquid volume rate (testing volumes of 182, 619, and 1603 l ha(-1)) and volumetric airflow rate (with flow rates of 11.93, 8.90, and 6.15 m(3) s(-1)) influences the coverage parameters and the amount and distribution of deposits in different zones of the canopy.. Our results showed that an increase in the application volume raised the mean deposit and percentage coverage, but decreased the application efficiency, spray penetration, and deposit homogeneity. Furthermore, we found that the volumetric airflow rate had a lower influence on the studied parameters than the liquid volume; however, an increase in the airflow rate improved the application efficiency and homogeneity to a certain threshold, after which the spray quality decreased. This decrease was observed in the high-flow treatment. Our results demonstrate that intermediate liquid volume rates and volumetric airflow rates are required for the optimal spraying of pesticides on super-intensive olive crops, and would reduce current pollution levels. PMID:26282759

  6. Long-term gage reliability for structural health monitoring of steel bridges

    NASA Astrophysics Data System (ADS)

    Samaras, Vasilis A.; Fasl, Jeremiah; Reichenbach, Matt; Helwig, Todd; Wood, Sharon; Frank, Karl

    2012-04-01

    Real-time monitoring of fracture critical steel bridges can potentially enhance inspection practices by tracking the behavior of the bridge. Significant advances have occurred in recent years on the development of robust hardware for field monitoring applications. These systems can monitor, process, and store data from a variety of sensors (e.g. strain gages, crack propagation gages etc.) to track changes in the behavior of the bridge. Thus, for a long-term monitoring system to be successful, the reliability of gages that are to be monitored for several years is very important. This paper focuses on the results of a research study focused on developing a wireless monitoring system with a useful life of more than 10 years. An important aspect of the study is to identify strain gages and installation procedures that result in long lives as well as characterizing the effect of temperature fluctuations and other environmental factors on the sensor drift and noise. In long-term monitoring applications, slight sensor drift and noise can build up over time to produce misleading results. Thus, a wide variety of gages that can be used to monitor bridges have been tested for over a year through environmental tests. The environmental tests were developed to determine the durability of the gages and their protective coatings (e.g. zinc-based spray, wax and silicon, etc.) against humidity, sun exposure and other environmental effects that are expected in long-term bridge monitoring applications. Moreover, fatigue tests were performed to determine the fatigue category of the weldable gages and to reveal any debonding issues of the bondable gages. This paper focuses on the results of laboratory tests on gage durability that were conducted as part of a research project sponsored by the National Institute of Standards and Technology (NIST).

  7. Evaluation of different airflow sensors at the WIPP facility

    SciTech Connect

    McDaniel, K.; Duckworth, I.J.; Prosser, B.S.

    1999-07-01

    The Waste Isolation Pilot Plant (WIPP) is an US Department of Energy underground disposal facility designed to permanently and safely isolate US defense-generated transuranic radioactive waste. The underground ventilation system is engineered to minimize the release of radioactive contamination to the environment in the event of an accident. During 1994 an extensive ventilation remote monitoring and control system was installed. It consists of fifteen air velocity sensors, eight differential pressure stations, automated control features on key underground air regulators, and eight psychrometric stations. The airflow monitoring component of the system has been a problem since the original installation. Due to the WIPP's variable airflow capabilities, the air velocity sensors required extensive and time-consuming re-calibration to make the sensors read out volumetric flow, rather than the point or line values, which they were factory calibrated for. Problems with the hardware made the process difficult. Furthermore, once re-calibrated the durability and reliability of the units were inconsistent, and often unacceptable. Two new types of airflow sensors were tested; one or both of which will ultimately replace the old units. The tested sensors were an ultrasonic-type device (FloSonic), and a warm body, mass flow unit (Airboss*200W) (a re-engineered version of the previous units). Recommendations were made regarding which type of sensor to install at specific locations. These decisions were based on the conditions at each sensor location and the relative strengths of the two sensor types. Installation, field calibration methodology, test procedures, main results and recommendations are discussed.

  8. Integrative pathway genomics of lung function and airflow obstruction.

    PubMed

    Gharib, Sina A; Loth, Daan W; Soler Artigas, María; Birkland, Timothy P; Wilk, Jemma B; Wain, Louise V; Brody, Jennifer A; Obeidat, Ma'en; Hancock, Dana B; Tang, Wenbo; Rawal, Rajesh; Boezen, H Marike; Imboden, Medea; Huffman, Jennifer E; Lahousse, Lies; Alves, Alexessander C; Manichaikul, Ani; Hui, Jennie; Morrison, Alanna C; Ramasamy, Adaikalavan; Smith, Albert Vernon; Gudnason, Vilmundur; Surakka, Ida; Vitart, Veronique; Evans, David M; Strachan, David P; Deary, Ian J; Hofman, Albert; Gläser, Sven; Wilson, James F; North, Kari E; Zhao, Jing Hua; Heckbert, Susan R; Jarvis, Deborah L; Probst-Hensch, Nicole; Schulz, Holger; Barr, R Graham; Jarvelin, Marjo-Riitta; O'Connor, George T; Kähönen, Mika; Cassano, Patricia A; Hysi, Pirro G; Dupuis, Josée; Hayward, Caroline; Psaty, Bruce M; Hall, Ian P; Parks, William C; Tobin, Martin D; London, Stephanie J

    2015-12-01

    Chronic respiratory disorders are important contributors to the global burden of disease. Genome-wide association studies (GWASs) of lung function measures have identified several trait-associated loci, but explain only a modest portion of the phenotypic variability. We postulated that integrating pathway-based methods with GWASs of pulmonary function and airflow obstruction would identify a broader repertoire of genes and processes influencing these traits. We performed two independent GWASs of lung function and applied gene set enrichment analysis to one of the studies and validated the results using the second GWAS. We identified 131 significantly enriched gene sets associated with lung function and clustered them into larger biological modules involved in diverse processes including development, immunity, cell signaling, proliferation and arachidonic acid. We found that enrichment of gene sets was not driven by GWAS-significant variants or loci, but instead by those with less stringent association P-values. Next, we applied pathway enrichment analysis to a meta-analyzed GWAS of airflow obstruction. We identified several biologic modules that functionally overlapped with those associated with pulmonary function. However, differences were also noted, including enrichment of extracellular matrix (ECM) processes specifically in the airflow obstruction study. Network analysis of the ECM module implicated a candidate gene, matrix metalloproteinase 10 (MMP10), as a putative disease target. We used a knockout mouse model to functionally validate MMP10's role in influencing lung's susceptibility to cigarette smoke-induced emphysema. By integrating pathway analysis with population-based genomics, we unraveled biologic processes underlying pulmonary function traits and identified a candidate gene for obstructive lung disease. PMID:26395457

  9. Airflow, gas deposition, and lesion distribution in the nasal passages

    SciTech Connect

    Morgan, K.T.; Monticello, T.M. )

    1990-04-01

    The nasal passages of laboratory animals and man are complex, and lesions induced in the delicate nasal lining by inhaled air pollutants vary considerably in location and nature. The distribution of nasal lesions is generally a consequence of regional deposition of the inhaled material, local tissue susceptibility, or a combination of these factors. Nasal uptake and regional deposition are are influenced by numerous factors including the physical and chemical properties of the inhaled material, such as water solubility and reactivity; airborne concentration and length of exposure; the presence of other air contaminants such as particulate matter; nasal metabolism, and blood and mucus flow. For certain highly water-soluble or reactive gases, nasal airflow patterns play a major role in determining lesion distribution. Studies of nasal airflow in rats and monkeys, using casting and molding techniques combined with a water-dye model, indicate that nasal airflow patterns are responsible for characteristic differences in the distribution of nasal lesions induced by formaldehyde in these species. Local tissue susceptibility is also a complex issue that may be a consequence of many factors, including physiologic and metabolic characteristics of the diverse cell populations that comprise each of the major epithelial types lining the airways. Identification of the principal factors that influence the distribution and nature of nasal lesions is important when attempting the difficult process of determining potential human risks using data derived from laboratory animals. Toxicologic pathologists can contribute to this process by carefully identifying the site and nature of nasal lesions induced by inhaled materials. 61 references.

  10. A study of the effect of apparent strain on thermal stress measurement for two types of elevated temperature strain gages

    NASA Technical Reports Server (NTRS)

    Jenkins, J. M.

    1983-01-01

    A weldable type strain gage was used to measure low level thermal stress in an elevated temperature environment. Foil strain gages used in a comparative manner reveal that the apparent strain of weldable strain gages is not sufficiently known to acquire accurate low level thermal stress data. Apparent strain data acquired from coupon tests reveals a large scatter in apparent strain characteristics among the weldable strain gages. It is concluded that apparent strain data for individual weldable strain gages must be required prior to installation if valid thermal stress data is to be obtained through the temperature range of room temperature to 755 K (900 F).

  11. High-Temperature Extensometry and PdCr Temperature-Compensated Wire Resistance Strain Gages Compared

    NASA Technical Reports Server (NTRS)

    1997-01-01

    A detailed experimental evaluation is underway at the NASA Lewis Research Center to compare and contrast the performance of the PdCr/Pt dual-element temperature-compensated wire resistance strain gage with that of conventional high-temperature extensometry. The advanced PdCr gage, developed by researchers at Lewis, exhibits desirable properties and a relatively small and repeatable apparent strain to 800 C. This gage represents a significant advance in technology because existing commercial resistance strain gages are not reliable for quasi-static strain measurements above approx. 400 C. Various thermal and mechanical loading spectra are being applied by a high-temperature thermomechanical uniaxial testing system to evaluate the two strain-measurement systems. This is being done not only to compare and contrast the two strain sensors, but also to investigate the applicability of the PdCr strain gage to the coupon-level specimen testing environment typically employed when the high-temperature mechanical behavior of structural materials is characterized. Strain measurement capabilities to 800 C are being investigated with a nickel-base superalloy, Inconel 100 (IN 100), substrate material and application to TMC's is being examined with the model system, SCS-6/Ti-15-3. Furthermore, two gage application techniques are being investigated in the comparison study: namely, flame-sprayed and spot welding. The apparent strain responses of both the weldable and flame-sprayed PdCr wire strain gages were found to be cyclically repeatable on both IN 100 and SCS-6/Ti-15-3 [0]_8. In general, each gage exhibited some uniqueness with respect to apparent strain behavior. Gages mounted on the IN 100 specimens tended to show a repeatable apparent strain within the first few cycles, because the thermal response of IN 100 was stable. This was not the case, however, for the TMC specimens, which typically required several thermal cycles to stabilize the thermal strain response. Thus

  12. Evaluation of airflow patterns in 2706-T and 2706-TA

    SciTech Connect

    DEROSA, D.C.

    1999-08-26

    The purpose of this study was to evaluate the adequacy of the current placement of fixed head air samplers and continuous air monitors (CAMs) in the 2706-T and 2706-TA Complex. The airflow study consisted of 6 configurations of facility HVAC and HEPA filtration equipment to determine impacts on CAM location. The results of this study provide recommendations based on guidance in DOE G 411.1-8 and NUREG-1400 for placement of fixed head air samplers or CAMS within 2706-T and 2706-TA.

  13. EFFECT OF AIRFLOW AND HEAT INPUT RATES ON DUCT EFFICIENCY.

    SciTech Connect

    ANDREWS,J.W.

    2003-05-28

    Reducing the airflow and heat input rates of a furnace that is connected to a duct system in thermal contact with unconditioned spaces can significantly reduce thermal distribution efficiency. This is a straightforward theoretical calculation based on the increased residence time of the air in the duct at the lower flow rate, which results in greater conduction losses. Experimental tests in an instrumented residential-size duct system have confirmed this prediction. Results are compared with the heat-loss algorithm in ASHRAE Standid 152P. The paper concludes with a discussion of possible remedies for this loss of efficiency in existing systems and optional design strategies in new construction.

  14. Vapor-Generator Wand Helps To Reveal Airflow Patterns

    NASA Technical Reports Server (NTRS)

    Robelen, David B.

    1993-01-01

    In vapor-generator wand, liquid propylene glycol flows into electrically heated stainless-steel tube. Liquid boils in heated tube, and emerging vapor forms dense, smoke-like fog used to make airflow patterns visible. Built in variety of sizes, suitable for uses ranging from tabletop demonstrations to research in wind tunnels. For best viewing, plume illuminated by bright, focused incandescent spotlight at right angle to viewing direction. Viewing further enhanced by coating walls of test chamber with flat, dark color to minimize reflections and increase contrast.

  15. Calibration approaches for distributed hydrologic models in poorly gaged basins: implication for streamflow projections under climate change

    NASA Astrophysics Data System (ADS)

    Wi, S.; Yang, Y. C. E.; Steinschneider, S.; Khalil, A.; Brown, C. M.

    2015-02-01

    This study tests the performance and uncertainty of calibration strategies for a spatially distributed hydrologic model in order to improve model simulation accuracy and understand prediction uncertainty at interior ungaged sites of a sparsely gaged watershed. The study is conducted using a distributed version of the HYMOD hydrologic model (HYMOD_DS) applied to the Kabul River basin. Several calibration experiments are conducted to understand the benefits and costs associated with different calibration choices, including (1) whether multisite gaged data should be used simultaneously or in a stepwise manner during model fitting, (2) the effects of increasing parameter complexity, and (3) the potential to estimate interior watershed flows using only gaged data at the basin outlet. The implications of the different calibration strategies are considered in the context of hydrologic projections under climate change. To address the research questions, high-performance computing is utilized to manage the computational burden that results from high-dimensional optimization problems. Several interesting results emerge from the study. The simultaneous use of multisite data is shown to improve the calibration over a stepwise approach, and both multisite approaches far exceed a calibration based on only the basin outlet. The basin outlet calibration can lead to projections of mid-21st century streamflow that deviate substantially from projections under multisite calibration strategies, supporting the use of caution when using distributed models in data-scarce regions for climate change impact assessments. Surprisingly, increased parameter complexity does not substantially increase the uncertainty in streamflow projections, even though parameter equifinality does emerge. The results suggest that increased (excessive) parameter complexity does not always lead to increased predictive uncertainty if structural uncertainties are present. The largest uncertainty in future streamflow

  16. Comparison of thin-film resistance heat-transfer gages with thin-skin transient calorimeter gages in conventional hypersonic wind tunnels

    NASA Technical Reports Server (NTRS)

    Miller, C. G., III

    1981-01-01

    Thin film gages deposited at the stagnation region of small (8.1-mm-diameter) hemispheres and gages mounted flush with the surface of a sharp-leading-edge flat plate were tested in the Langley continuous-flow hypersonic tunnel and in the Langley hypersonic CF4 tunnel. Two substrate materials were tested, quartz and a machinable glass-ceramic. Small hemispheres were also tested utilizing the thin-skin transient calorimeter technique usually employed in conventional tunnels. One transient calorimeter model was a thin shell of stainless steel, and the other was a thin-skin insert of stainless steel mounted into a hemisphere fabricated from a machinable-glass-ceramic. Measured heat-transfer rates from the various hemispheres were compared with one another and with predicted rates. The results demonstrate the feasibility and advantages of using-film resistance heat-transfer gages in conventional hypersonic wind tunnels over a wide range of conditions.

  17. Mechanism of bronchodilator effect in chronic airflow limitation.

    PubMed Central

    Jaeschke, R; Guyatt, G H; Singer, J; Keller, J; Newhouse, M T

    1991-01-01

    OBJECTIVE: To examine the mechanisms through which two bronchodilators (theophylline and salbutamol) influence dyspnea during daily activities. METHODS: Twenty-four patients with chronic airflow limitation participated in a multiple crossover, randomized, placebo-controlled trial. The effect of theophylline and salbutamol, alone or combined, on pulmonary function and dyspnea during daily activities was examined. Correlations of changes in forced expiratory volume in 1 second (FEV1) and maximum expiratory pressures (MIPs) (independent variables) and changes in dyspnea score during daily activities (dependent variable) were also examined. RESULTS: The two drugs proved to be beneficial the effects in general were additive rather than synergistic. The drugs improved the FEV1; theophylline significantly improved the MIPs. The correlation between the changes in FEV1 and those in dyspnea score, after adjustment for the changes in MIPs, was 0.55 (p less than 0.001). The correlation between the changes in MIPs and those in dyspnea score, after adjustment for the changes in FEV1, was 0.39 (p less than 0.001). CONCLUSIONS: Changes in airway calibre and in respiratory muscle strength play an independent and important role in dyspnea during daily activities in patients with chronic airflow limitation. Changes in airway calibre may be of greater importance. PMID:1984814

  18. Forced-air patient warming blankets disrupt unidirectional airflow.

    PubMed

    Legg, A J; Hamer, A J

    2013-03-01

    We have recently shown that waste heat from forced-air warming blankets can increase the temperature and concentration of airborne particles over the surgical site. The mechanism for the increased concentration of particles and their site of origin remained unclear. We therefore attempted to visualise the airflow in theatre over a simulated total knee replacement using neutral-buoyancy helium bubbles. Particles were created using a Rocket PS23 smoke machine positioned below the operating table, a potential area of contamination. The same theatre set-up, warming devices and controls were used as in our previous study. This demonstrated that waste heat from the poorly insulated forced-air warming blanket increased the air temperature on the surgical side of the drape by > 5°C. This created convection currents that rose against the downward unidirectional airflow, causing turbulence over the patient. The convection currents increased the particle concentration 1000-fold (2 174 000 particles/m(3) for forced-air warming vs 1000 particles/m(3) for radiant warming and 2000 particles/m(3) for the control) by drawing potentially contaminated particles from below the operating table into the surgical site. Cite this article: Bone Joint J 2013;95-B:407-10. PMID:23450029

  19. Inspirational airflow patterns in deviated noses: a numerical study.

    PubMed

    Zhu, Jian Hua; Lee, Heow Pueh; Lim, Kian Meng; Lee, Shu Jin; San, Lynette Teo Li; Wang, De Yun

    2013-01-01

    This study attempts to evaluate the effects of deviation of external nose to nasal airflow patterns. Four typical subjects were chosen for model reconstruction based on computed tomography images of undeviated, S-shaped deviated, C-shaped deviated and slanted deviated noses. To study the hypothetical influence of deviation of external nasal wall on nasal airflow (without internal blockage), the collapsed region along the turbinate was artificially reopened in all the three cases with deviated noses. Computational fluid dynamics simulations were carried out in models of undeviated, original deviated and reopened nasal cavities at both flow rates of 167 and 500 ml/s. The shape of the anterior nasal roof was found to be collapsed on one side of the nasal airways in all the deviated noses. High wall shear stress region was found around the collapsed anterior nasal roof. The nasal resistances in cavities with deviated noses were considerably larger than healthy nasal cavity. Patterns of path-line distribution and wall shear stress distribution were similar between original deviated and reopened models. In conclusion, the deviation of an external nose is associated with the collapse of one anterior nasal roof. The crooked external nose induced a larger nasal resistance compared to the undeviated case, while the internal blockage of the airway along the turbinates further increased it. PMID:22515677

  20. Impact gages for detecting meteoroid and other orbital debris impacts on space vehicles.

    NASA Technical Reports Server (NTRS)

    Mastandrea, J. R.; Scherb, M. V.

    1973-01-01

    Impacts on space vehicles have been simulated using the McDonnell Douglas Aerophysics Laboratory (MDAL) Light-Gas Guns to launch particles at hypervelocity speeds into scaled space structures. Using impact gages and a triangulation technique, these impacts have been detected and accurately located. This paper describes in detail the various types of impact gages (piezoelectric PZT-5A, quartz, electret, and off-the-shelf plastics) used. This description includes gage design and experimental results for gages installed on single-walled scaled payload carriers, multiple-walled satellites and space stations, and single-walled full-scale Delta tank structures. A brief description of the triangulation technique, the impact simulation, and the data acquisition system are also included.

  1. A hot-wire surface gage for skin friction and separation detection measurements

    NASA Technical Reports Server (NTRS)

    Rubesin, M. W.; Okuno, A. F.; Mateer, G. G.; Brosh, A.

    1975-01-01

    A heated-element, skin-friction gage employing a very low thermal conductivity support is described. It is shown that the effective dimension of the gage in the stream direction in only 0.06 mm, including the effects of heat conduction in the supporting material. Because of its small size, the calibration of the gage is independent of the kind of boundary-layer flow (whether laminar or turbulent) and is insensitive to pressure gradients. Construction tolerances can be maintained so that a single universal calibration can be applied. Multiple gages, sufficiently closely spaced so as to interfere with each other, are shown to provide accurate determinations of the locations of the points of boundary-layer separation and reattachment.

  2. Cost effectiveness of the stream-gaging program in northeastern California

    USGS Publications Warehouse

    Hoffard, S.H.; Pearce, V.F.; Tasker, Gary D.; Doyle, W.H.

    1984-01-01

    Results are documented of a study of the cost effectiveness of the stream-gaging program in northeastern California. Data uses and funding sources were identified for the 127 continuous stream gages currently being operated in the study area. One stream gage was found to have insufficient data use to warrant cooperative Federal funding. Flow-routing and multiple-regression models were used to simulate flows at selected gaging stations. The models may be sufficiently accurate to replace two of the stations. The average standard error of estimate of streamflow records is 12.9 percent. This overall level of accuracy could be reduced to 12.0 percent using computer-recommended service routes and visit frequencies. (USGS)

  3. Demonstration test of burner liner strain measurements using resistance strain gages

    NASA Technical Reports Server (NTRS)

    Grant, H. P.; Anderson, W. L.

    1984-01-01

    A demonstration test of burner liner strain measurements using resistance strain gages as well as a feasibility test of an optical speckle technique for strain measurement are presented. The strain gage results are reported. Ten Kanthal A-1 wire strain gages were used for low cycle fatigue strain measurements to 950 K and .002 apparent strain on a JT12D burner can in a high pressure (10 atmospheres) burner test. The procedure for use of the strain gages involved extensive precalibration and postcalibration to correct for cooling rate dependence, drift, and temperature effects. Results were repeatable within + or - .0002 to .0006 strain, with best results during fast decels from 950 K. The results agreed with analytical prediction based on an axisymmetric burner model, and results indicated a non-uniform circumferential distribution of axial strain, suggesting temperature streaking.

  4. Problems Associated with Attaching Strain Gages to Titanium Alloy Ti-61-4V

    NASA Technical Reports Server (NTRS)

    Jenkins, J. M.; Lemcoe, M. M.

    1977-01-01

    Weldable strain gages have shown excellent high temperature characteristics for supersonic cruise aircraft application. The spotwelding attachment method, however, has resulted in serious reductions in the fatigue life of titanium alloy (Ti-6Al-4V) fatigue specimens. The reduction is so severe that the use of weldable strain gages on operational aircraft must be prohibited. The cause of the fatigue problem is thought to be a combination of the microstructure changes in the material caused by spotwelding and the presence of the flange of the stain gage. Brazing, plating, and plasma spraying were investigated as substitutes for spotwelding. The attachment of a flangeless gage by plasma spraying provided the most improvement in the fatigue life of the titanium.

  5. Calibration of strain-gage installations in aircraft structures for the measurement of flight loads

    NASA Technical Reports Server (NTRS)

    Skopinski, T H; Aiken, William S , Jr; Huston, Wilber B

    1954-01-01

    A general method has been developed for calibrating strain-gage installations in aircraft structures, which permits the measurement in flight of the shear or lift, the bending moment, and the torque or pitching moment on the principal lifting or control surfaces. Although the stress in structural members may not be a simple function of the three loads of interest, a straightforward procedure is given for numerically combining the outputs of several bridges in such a way that the loads may be obtained. Extensions of the basic procedure by means of electrical combination of the strain-gage bridges are described which permit compromises between strain-gage installation time, availability of recording instruments, and data reduction time. The basic principles of strain-gage calibration procedures are illustrated by reference to the data for two aircraft structures of typical construction, one a straight and the other a swept horizontal stabilizer.

  6. A pragmatic approach to evaluating a multipurpose stream-gaging network

    USGS Publications Warehouse

    Wahl, K.L.; Crippen, J.R.

    1984-01-01

    A method for evaluating the relative worth of individual streamflow gaging stations in a multipupose network is presented. Each individual gaging station in the network is evaluated on the basis of selected rating factors. The factors relate to the need for information at the gaging stations, accuracy of data, economic aspects of operation, and usefulness of data as a basis for estimates at ungaged sites. The total score for the various factors provides a convenient basis for comparing relative importance of individual gaging stations. The rating-factor method is both flexible and definitive, but the point values that are assigned for each rating factor are somewhat subjective. A table of the point values and guidelines for assigning those values is presented. (USGS)

  7. Evaluation of submarine strain-gage systems for monitoring coastal sediment migration

    NASA Technical Reports Server (NTRS)

    Shideler, G. L.; Mcgrath, D. G.

    1973-01-01

    Single and multiple strain-gage systems were respectively evaluated as in situ point and areal sensors for monitoring sand-height variations in coastal environments. Static loading tests indicate that gage response pressure is linear for sand heights up to 24 inches. Response pressures are a function of both sand height and aggregate density, with density being influenced by both sediment texture and degree of compaction. Poorer sediment sorting and greater compaction result in higher response pressures. Field tests in a beach foreshore environment indicate that the gage systems are effective qualitative instruments for monitoring long-period migration trends of beach sediments; whereas, short-period responses are not sufficiently reliable. The durability and compactness of the gage systems must be substantially increased for effective field operations. It is recommended that the systems' qualitative potentials be further developed, whereas their development as quantitative instruments be terminated. Further development should emphasize the construction of remote recording systems designed for semipermanent installation.

  8. Six-component strain gage block scale 167-6B. Part 1: Calibration, September 1983

    NASA Astrophysics Data System (ADS)

    Wyss, C.

    1983-11-01

    The calibration of a six-component strain gage block balance for measurements in wind tunnels is described. The temperature dependance is considered. An error estimation is given. Calibration measurements are presented.

  9. Characteristics of Extrinsic Fabry-Perot Interferometric (EFPI) Fiber-Optic Strain Gages

    NASA Technical Reports Server (NTRS)

    Hare, David A.; Moore, Thomas C., Sr.

    2000-01-01

    The focus of this paper is a comparison of the strain-measuring characteristics of one type of commercially available fiber-optic strain sensor with the performance of conventional resistance strain gages. Fabry-Perot type fiber-optic strain sensors were selected for this testing program. Comparative testing is emphasized and includes load testing at room temperature with apparent strain characterization cryogenically and at elevated temperatures. The absolute accuracy of either of these types of strain gages is not addressed.

  10. Electrical Properties of Materials for Elevated Temperature Resistance Strain Gage Application. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Lei, Jih-Fen

    1987-01-01

    The objective was to study the electrical resistances of materials that are potentially useful as resistance strain gages at 1000 C. Transition metal carbides and nitrides, boron carbide and silicon carbide were selected for the experimental phase of this research. Due to their low temperature coefficient of resistance and good stability, TiC, ZrC, B sub 4 C and beta-SiC are suggested as good candidates for high temperature resistance strain gage applications.

  11. Performance evaluation of the Enraf-Nonius Model 872 radar gage

    SciTech Connect

    Peters, T.J.; Park, W.R.

    1992-12-01

    There are indications that the Enraf-Nonius Radar Gage installed in Tank 241-SY-101 may not be providing an accurate reading of the true surface level in the waste tank. The Pacific Northwest Laboratory (PNL) performed an initial study to determine the effect of the following items on the distance read by the gage: Tank riser; Material permittivity and conductivity Foam; Proportion of supernatant to solid material in the field of view of the instrument; Physical geometry of the supernatant and solid material changing in the field of view with respect to time; and Varying water content in the solid material. The results of the tests indicate that distance measured by the radar gage is affected by the permittivity, conductivity, and angle of the target surface. These parameters affect the complex input impedance of the signal received by the radar gage to measure the distance to the target. In Tank 101-SY, the radar gage is placed on top of a 12 in. diameter riser. The riser affects the field of view of the instrument, and a much smaller target surface is detected when the radar beam propagates through a riser. In addition, the riser acts as a waveguide, and standing waves are enhanced between the target surface and the radar gage. The result is a change in the level measured by the radar gage due to changing properties of the target surface even when the distance to the target does not change. The test results indicate that the radar will not detect dry crust or foam. However, if the crust or foam is stirred so that it becomes wet, then the crust or foam became detectable. The level read using the radar gage decreased as the moisture in the crust or foam evaporated.

  12. Data uses and funding of the stream-gaging program in Missouri

    USGS Publications Warehouse

    Waite, L.A.

    1984-01-01

    This report documents the results of a study of the data uses and funding of the stream-gaging program in Missouri. Presently (1984), 100 continuous-record streamflow-gaging stations are operated in Missouri on a budget of $633,345. Data uses and funding sources are identified for each of the stations. Data from most stations have multiple uses. All stations presently have sufficient justification for continuation. (USGS)

  13. Application of Temperature Sensitivities During Iterative Strain-Gage Balance Calibration Analysis

    NASA Technical Reports Server (NTRS)

    Ulbrich, N.

    2011-01-01

    A new method is discussed that may be used to correct wind tunnel strain-gage balance load predictions for the influence of residual temperature effects at the location of the strain-gages. The method was designed for the iterative analysis technique that is used in the aerospace testing community to predict balance loads from strain-gage outputs during a wind tunnel test. The new method implicitly applies temperature corrections to the gage outputs during the load iteration process. Therefore, it can use uncorrected gage outputs directly as input for the load calculations. The new method is applied in several steps. First, balance calibration data is analyzed in the usual manner assuming that the balance temperature was kept constant during the calibration. Then, the temperature difference relative to the calibration temperature is introduced as a new independent variable for each strain--gage output. Therefore, sensors must exist near the strain--gages so that the required temperature differences can be measured during the wind tunnel test. In addition, the format of the regression coefficient matrix needs to be extended so that it can support the new independent variables. In the next step, the extended regression coefficient matrix of the original calibration data is modified by using the manufacturer specified temperature sensitivity of each strain--gage as the regression coefficient of the corresponding temperature difference variable. Finally, the modified regression coefficient matrix is converted to a data reduction matrix that the iterative analysis technique needs for the calculation of balance loads. Original calibration data and modified check load data of NASA's MC60D balance are used to illustrate the new method.

  14. 46 CFR 38.10-20 - Liquid level gaging devices-TB/ALL.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Liquid level gaging devices-TB/ALL. 38.10-20 Section 38.10-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS LIQUEFIED FLAMMABLE GASES Piping, Valves, Fittings, and Accessory Equipment § 38.10-20 Liquid level gaging devices—TB/ALL. (a) Each tank shall be fitted with a liquid...

  15. Analysis of the peak-flow gaging network in North Dakota

    USGS Publications Warehouse

    Williams-Sether, Tara

    1996-01-01

    A network analysis technique using generalized least-squares regression was used to evaluate the current (1993) peak-flow gaging network that provides regional peak-flow information for North Dakota. The analysis was conducted to evaluate the current (1993) network and to determine if reactivating discontinued gaging stations and adding new gaging stations on small drainage areas would improve regional peak-flow information. Peak flows having recurrence intervals of 15, 50, and 100 years and planning horizons of zero and 10 years for three hydrologic regions in North Dakota were used in the network analysis. Results of the network analysis indicate that the average sampling mean-square error could be reduced by about 10 percent for the 15-, 50-, and 100-year recurrence intervals by reactivating a minimum of two to five discontinued gaging stations in each hydrologic region. The reactivated discontinued gaging stations added to the current (1993) network should be located on streams having small drainage areas and steep main-channel slopes. For the 15-year recurrence interval and a 10-year planning horizon, adding a new gaging station at two new locations in each region instead of reactivating two discontinued gaging stations in each region would reduce the average sampling mean-square error by an average of about 13 percent in each region. The new gaging stations added to the current (1993) network should be located on streams having small drainage areas and mild or steep main-channel slopes in order to obtain improved regional peak-flow information.

  16. Cost-effectiveness of the stream-gaging program in Maine

    USGS Publications Warehouse

    Fontaine, Richard A.; Moss, M.E.; Smath, J.A.; Thomas, W.O.

    1983-01-01

    Data uses and funding sources were identified for the 51 continuous stream gages currently being operated in Maine. Three stream-gages were identified as having insufficient reason to continue their operation. Operation of these stations were identified as having uses specific only to short-term studies; it is recommended that these stations be discontinued at the end of the data-collection phases of the studies. The remaining 45 stations should be maintained in the program for the foreseeable future. The current policy for operation of the 45-station program would require $180,300 per year. The average standard error of estimation of streamflow record is 18.5 percent. It was shown that this overall level of accuracy at the 45 sites could be maintained with a budget of $170,000 if the gaging resources were redistributed among the gages. A minimum budget of $155,000 is required to operate the 45-gage program; a budget less than this does not permit proper service and maintenance of the gages and recorders. At the minimum budget, the average standard error is 26.0 percent. The maximum budget analyzed was $350,000, which resulted in an average standard error of 9.2 percent. Large parts of Maine 's interior were identified as having sparse stream-flow data. It was recommended that this sparsity should be remedied as funds can be made available. (USGS)

  17. Overcoring and calibration of IRAD GAGE stressmeters at the Spent Fuel Test in Climax granite

    SciTech Connect

    Mao, N.

    1984-09-15

    IRAD GAGE vibrating-wire stressmeters were installed in the Spent Fuel Facility at the Nevada Test Site to measure the change in in-situ stress during the Spent Fuel Test-Climax (SFT-C). Although extensive pre-installation laboratory tests were conducted, they were generic in nature. Unfortunately the degree of gage-rock contact has a strong influence on gage sensitivity and cannot be predicted before installation. This report discusses the results of removing a cylindrical section of rock and gages as a unit through overcoring and the subsequent post test calibrations of the stressmeters in the laboratory. With the assumption that the gage-rock contact was not disturbed by the overcoring, the results from these calibrations compensate for varying gage-rock contact. The estimated in-situ stresses based on post test calibration data are quite consistent with those directly measured in nearby holes. The magnitude of stress change calculated from pre-installation test data is generally much smaller than that estimated from post test calibration data.

  18. Design and development of a miniature column-based interface (MCBI) stress gage

    NASA Astrophysics Data System (ADS)

    Rickman, Denis D.

    1993-04-01

    Tests are routinely conducted to evaluate the survivability, under simulated battlefield conditions, of buried military structures subjected to high-explosive loadings. The survivability assessments require the measurement of dynamic normal stresses induced at soil/structure interfaces. Stresses in excess of 10,000 psi and accelerations greater than 100,000 g's may be applied at interface locations. Normal-incidence interface stress gages currently used in such tests are incapable of accurately measuring stresses above 5,000 psi, and are sensitive to lateral accelerations and structure-transmitted stresses which distort the measurement. This study explores the design, development, and testing of a miniature, column-based, interface (MCBI) stress gage. The MCBI gage is designed to measure normal stresses up to 35,000 psi. Laboratory tests indicate that the gage produces a linear output due to applied pressure and is virtually insensitive to lateral stresses. Explosive tests have shown the MCBI gage compares favorably to commonly-used interface stress gages at stresses up to 3,000 psi and is survivable at stresses up to 25,000 psi.

  19. A mechanical and histomorphometric analysis of bone bonding by hydroxyapatite-coated strain gages.

    PubMed

    Wilson, D L; Szivek, J A; Anderson, P L; Miera, V L; Battraw, G A

    1998-01-01

    Identification of the strains controlling bone remodeling is important for determining ways to prevent bone loss due to load deprivation, or implant placement. Long-term monitoring of strains can potentially provide the best information. Glues are resorbed within 2-3 weeks. Two formulations of microcrystalline hydroxyapatite (HA) were used to attach strain gages to rat femora to assess their long-term in vivo strain measurement capability. Seven male rats received HA-coated gages, and 2 animals underwent a sham procedure. The gages were prepared using a published technique and placed on the antero-lateral aspect of the left femora. After 6-7 weeks, the animals were euthanized and both femora explanted. Gages were attached to the right femora with cyanoacrylate. All femora were tested in cantilever bending, then embedded, sectioned, and stained with mineralized bone stain. The undecalcified sections were examined using transmitted and ultraviolet light microscopy. Mechanical testing showed one HA formulation provided 70-100% bonding. Histology showed intimate contact between the gage and bone surface. Histomorphometry indicated increased bone activity under the gage compared to the remaining bone, the controls, and the shams. The results indicate that microcrystalline HAs bond to bone quickly and can allow long term in vivo measurements. PMID:9659635

  20. 42 CFR 84.1149 - Airflow resistance tests; all dust, fume, and mist respirators; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Airflow resistance tests; all dust, fume, and mist... RESPIRATORY PROTECTIVE DEVICES Dust, Fume, and Mist; Pesticide; Paint Spray; Powered Air-Purifying High Efficiency Respirators and Combination Gas Masks § 84.1149 Airflow resistance tests; all dust, fume, and...

  1. Estimating Engine Airflow in Gas-Turbine Powered Aircraft with Clean and Distorted Inlet Flows

    NASA Technical Reports Server (NTRS)

    Williams, J. G.; Steenken, W. G.; Yuhas, A. J.

    1996-01-01

    The P404-GF-400 Powered F/A-18A High Alpha Research Vehicle (HARV) was used to examine the impact of inlet-generated total-pressure distortion on estimating levels of engine airflow. Five airflow estimation methods were studied. The Reference Method was a fan corrected airflow to fan corrected speed calibration from an uninstalled engine test. In-flight airflow estimation methods utilized the average, or individual, inlet duct static- to total-pressure ratios, and the average fan-discharge static-pressure to average inlet total-pressure ratio. Correlations were established at low distortion conditions for each method relative to the Reference Method. A range of distorted inlet flow conditions were obtained from -10 deg. to +60 deg. angle of attack and -7 deg. to +11 deg. angle of sideslip. The individual inlet duct pressure ratio correlation resulted in a 2.3 percent airflow spread for all distorted flow levels with a bias error of -0.7 percent. The fan discharge pressure ratio correlation gave results with a 0.6 percent airflow spread with essentially no systematic error. Inlet-generated total-pressure distortion and turbulence had no significant impact on the P404-GE400 engine airflow pumping. Therefore, a speed-flow relationship may provide the best airflow estimate for a specific engine under all flight conditions.

  2. IEA BESTEST Multi-Zone Non-Airflow In-Depth Diagnostic Cases: Preprint

    SciTech Connect

    Neymark, J.; Judkoff, R.; Alexander, D.; Felsmann, C.; Strachan, P.; Wijsman, A.

    2011-11-01

    This paper documents a set of in-depth diagnostic test cases for multi-zone heat transfer models that do not include the heat and mass transfer effects of airflow between zones. The multi-zone non-airflow test cases represent an extension to IEA BESTEST (Judkoff and Neymark 1995a).

  3. Internships and UNAVCO: Training the Future Geoscience Workforce Through the NSF GAGE Facility

    NASA Astrophysics Data System (ADS)

    Morris, A. R.; MacPherson-Krutsky, C. C.; Charlevoix, D. J.; Bartel, B. A.

    2015-12-01

    Facilities are uniquely positioned to both serve a broad, national audience and provide unique workforce experience to students and recent graduates. Intentional efforts dedicated to broadening participation in the future geoscience workforce at the NSF GAGE (Geodesy Advancing Geosciences and EarthScope) Facility operated by UNAVCO, are designed to meet the needs of the next generation of students and professionals. As a university-governed consortium facilitating research and education in the geosciences, UNAVCO is well-situated to both prepare students for geoscience technical careers and advanced research positions. Since 1998, UNAVCO has offered over 165 student assistant or intern positions including engineering, data services, education and outreach, and business support. UNAVCO offers three formal programs: the UNAVCO Student Internship Program (USIP), Research Experiences in Solid Earth Science for Students (RESESS), and the Geo-Launchpad (GLP) internship program. Interns range from community college students up through graduate students and recent Masters graduates. USIP interns gain real-world work experience in a professional setting, collaborate with teams toward a common mission, and contribute their knowledge, skills, and abilities to the UNAVCO community. RESESS interns conduct authentic research with a scientist in the Front Range area as well as participate in a structured professional development series. GLP students are in their first 2 years of higher education and work alongside UNAVCO technical staff gaining valuable work experience and insight into the logistics of supporting scientific research. UNAVCO's efforts in preparing the next generation of scientists largely focuses on increasing diversity in the geosciences, whether continuing academic studies or moving into the workforce. To date, well over half of our interns and student assistants come from backgrounds historically underrepresented in the geosciences. Over 80% of former interns

  4. Analysis of streamflow-gaging network for monitoring stormwater in small streams in the Puget Sound Basin, Washington

    USGS Publications Warehouse

    Konrad, Christopher P.; Voss, Frank D.

    2012-01-01

    The streamflow-gaging network in the Puget Sound basin was analyzed for its capacity to monitor stormwater in small streams. The analysis consisted of an inventory of active and inactive gages and an evaluation of the coverage and resolution of the gaging network with an emphasis on lowland areas. The active gaging network covers much of the Puget Lowland largely by gages located at sites on larger streams and rivers. Assessments of stormwater impacts and management will likely require streamflow information with higher spatial resolution than provided by the current gaging network. Monitoring that emphasizes small streams in combination with approaches for estimating streamflow at ungaged sites provides an alternative to expanding the current gaging network that can improve the spatial resolution of streamflow information in the region. The highest priority gaps in the gaging network are low elevation basins close to the Puget Sound shoreline and sites that share less than 10 percent of the drainage area of an active gage. Although small, lowland sites with long records of streamflow are particularly valuable to maintain in the region, other criteria for prioritizing sites in the gaging network should be based on the specific questions that stormwater managers need to answer.

  5. A Theoretical Study on Airflow Motive Force and Heat Transfer by the Water Spray

    NASA Astrophysics Data System (ADS)

    Sakai, Yasuyuki

    On assuming the abscissa moving uniformly with the horizontal airflow in disregard of gravity, airflow motive force and heat transfer by the water spray have been easily analyzed theoretically. Here main results are as follows. The theoretical maximum airflow motive pressure is proportional to both the initial relative velocity of waterdrop and the relative water flow per unit cross-sectional area of the apparatus to the airflow or the moving abscissa but unrelated to the size of waterdrop. The airflow motive pressure approaches to the above maximum with an increase in the length of the apparatus. Making the waterdrop size smaller has an effect on the aparatus to get longer virtually. The initial velocity of waterdrop or the spraying nozzle pressure has little effect on the heat transfer between the air and the water.

  6. Differently patterned airflows induced by 1-kHz femtosecond laser filaments in a cloud chamber

    NASA Astrophysics Data System (ADS)

    Sun, Haiyi; Liang, Hong; Liu, Yonghong; Ju, Jingjing; Wei, Yingxia; Wang, Cheng; Wang, Tiejun; Liu, Jiansheng; Chin, See Leang; Li, Ruxin; Xu, Zhizhan

    2015-11-01

    Airflow induced by femtosecond laser (800 nm/1 kHz/25 fs) filamentation with different lengths was investigated in a laboratory cloud chamber. Various filament lengths were generated by adjusting laser energy and lens focal length. It was found that airflow patterns are closely related to filament intensity and length. Intense and long filaments are beneficial in updraft generation with large vortices above the filament, while intense and short filaments tend to promote the formation of well-contacted vortices below the filament. Differently patterned airflows induced elliptical snow piles with different masses. We simulated airflow in a cloud chamber numerically taking laser filaments as heat sources. The mechanisms of differently patterned airflow and snow formation induced by filaments were discussed.

  7. Volume Diffuse Dielectric Barrier Discharge Plasma Produced by Nanosecond High Voltage Pulse in Airflow

    NASA Astrophysics Data System (ADS)

    Qi, Haicheng; Gao, Wei; Fan, Zhihui; Liu, Yidi; Ren, Chunsheng

    2016-05-01

    Volume diffuse dielectric barrier discharge (DBD) plasma is produced in subsonic airflow by nanosecond high-voltage pulse power supply with a plate-to-plate discharge cell at 6 mm air gap length. The discharge images, optical emission spectra (OES), the applied voltage and current waveforms of the discharge at the changed airflow rates are obtained. When airflow rate is increased, the transition of the discharge mode and the variations of discharge intensity, breakdown characteristics and the temperature of the discharge plasma are investigated. The results show that the discharge becomes more diffuse, discharge intensity is decreased accompanied by the increased breakdown voltage and time lag, and the temperature of the discharge plasma reduces when airflow of small velocity is introduced into the discharge gap. These phenomena are because that the airflow changes the spatial distribution of the heat and the space charge in the discharge gap. supported by National Natural Science Foundation of China (No. 51437002)

  8. Energy savings from repair of uncontrolled airflow in 18 small commercial buildings

    SciTech Connect

    Withers, C.R. Jr.; Cummings, J.B.; Fairey, P.W.; McKendry, B.B.; Moyer, N.A.

    1996-12-31

    Uncontrolled airflow, including duct leakage, pressure imbalances caused by closed interior doors, and exhaust/intake airflow imbalance, was characterized in 70 commercial buildings. In 18 of these buildings, uncontrolled airflows were repaired and energy savings from these repairs were monitored. In most buildings, the retrofit was duct repair. In other cases, outdoor airflow was reduced and return air transfers were provided. Cooling energy use was reduced by an average 15.1% in these 18 buildings. With an average repair cost of $455 and average cooling energy savings of $195 per year, uncontrolled airflow retrofits proved to be very cost-effective. Various factors indicate that greater energy savings could be achieved in the future.

  9. Interactions between surface roughness and airflow turbulence affecting drying dynamics of rough porous surfaces

    NASA Astrophysics Data System (ADS)

    Haghighi, Erfan; Kirchner, James; Or, Dani

    2016-04-01

    Evaporative drying of porous surfaces interacting with turbulent airflows is common in various industrial and natural applications. The intrinsic relief and roughness of natural porous surfaces are likely to influence the structure of interacting turbulent airflow boundary layers, and thus affect rates and patterns of heat and vapor fluxes from the surface. These links have been formalized in new mechanistic models that consider intermittent and localized turbulence-induced boundary layers, resulting in rich surface evaporation and energy exchange dynamics. The models were evaluated experimentally by systematically varying surface roughness elements in drying experiments of wavy and bluff-body covered sand surfaces in a wind tunnel. Thermal infrared signatures of localized evaporative fluxes as well as mean evaporative mass losses were recorded. The resulting patterns were in good agreement with model predictions for local and surface averaged turbulent exchange rates. Experimental and theoretical results suggest that evaporative water losses from wavy sand surfaces can be either enhanced or suppressed (relative to a flat surface), due to the complex interplay between the local boundary layer thickness and internal limitations on water flow to the evaporating surface. For sand surfaces covered by isolated cylindrical elements (bluff bodies), model predictions and measurements show persistent enhancement of evaporative fluxes from bluff-rough surfaces compared to a flat surface under similar conditions. This enhancement is attributed to the formation of vortices that thin the boundary layer over part of the interacting surface footprint. The implications of this study for interpreting and upscaling evapotranspiration rates from terrestrial surfaces will be discussed.

  10. Reevaluating Assembly Evaluations with Feature Response Curves: GAGE and Assemblathons

    PubMed Central

    Vezzi, Francesco; Narzisi, Giuseppe; Mishra, Bud

    2012-01-01

    In just the last decade, a multitude of bio-technologies and software pipelines have emerged to revolutionize genomics. To further their central goal, they aim to accelerate and improve the quality of de novo whole-genome assembly starting from short DNA sequences/reads. However, the performance of each of these tools is contingent on the length and quality of the sequencing data, the structure and complexity of the genome sequence, and the resolution and quality of long-range information. Furthermore, in the absence of any metric that captures the most fundamental “features” of a high-quality assembly, there is no obvious recipe for users to select the most desirable assembler/assembly. This situation has prompted the scientific community to rely on crowd-sourcing through international competitions, such as Assemblathons or GAGE, with the intention of identifying the best assembler(s) and their features. Somewhat circuitously, the only available approach to gauge de novo assemblies and assemblers relies solely on the availability of a high-quality fully assembled reference genome sequence. Still worse, reference-guided evaluations are often both difficult to analyze, leading to conclusions that are difficult to interpret. In this paper, we circumvent many of these issues by relying upon a tool, dubbed , which is capable of evaluating de novo assemblies from the read-layouts even when no reference exists. We extend the FRCurve approach to cases where lay-out information may have been obscured, as is true in many deBruijn-graph-based algorithms. As a by-product, FRCurve now expands its applicability to a much wider class of assemblers – thus, identifying higher-quality members of this group, their inter-relations as well as sensitivity to carefully selected features, with or without the support of a reference sequence or layout for the reads. The paper concludes by reevaluating several recently conducted assembly competitions and the datasets that have

  11. Effectiveness of the New Hampshire stream-gaging network in providing regional streamflow information

    USGS Publications Warehouse

    Olson, Scott A.

    2003-01-01

    The stream-gaging network in New Hampshire was analyzed for its effectiveness in providing regional information on peak-flood flow, mean-flow, and low-flow frequency. The data available for analysis were from stream-gaging stations in New Hampshire and selected stations in adjacent States. The principles of generalized-least-squares regression analysis were applied to develop regional regression equations that relate streamflow-frequency characteristics to watershed characteristics. Regression equations were developed for (1) the instantaneous peak flow with a 100-year recurrence interval, (2) the mean-annual flow, and (3) the 7-day, 10-year low flow. Active and discontinued stream-gaging stations with 10 or more years of flow data were used to develop the regression equations. Each stream-gaging station in the network was evaluated and ranked on the basis of how much the data from that station contributed to the cost-weighted sampling-error component of the regression equation. The potential effect of data from proposed and new stream-gaging stations on the sampling error also was evaluated. The stream-gaging network was evaluated for conditions in water year 2000 and for estimated conditions under various network strategies if an additional 5 years and 20 years of streamflow data were collected. The effectiveness of the stream-gaging network in providing regional streamflow information could be improved for all three flow characteristics with the collection of additional flow data, both temporally and spatially. With additional years of data collection, the greatest reduction in the average sampling error of the regional regression equations was found for the peak- and low-flow characteristics. In general, additional data collection at stream-gaging stations with unregulated flow, relatively short-term record (less than 20 years), and drainage areas smaller than 45 square miles contributed the largest cost-weighted reduction to the average sampling error of the

  12. Evaluation of the streamflow-gaging network of Alaska in providing regional streamflow information

    USGS Publications Warehouse

    Brabets, Timothy P.

    1996-01-01

    In 1906, the U.S. Geological Survey (USGS) began operating a network of streamflow-gaging stations in Alaska. The primary purpose of the streamflow- gaging network has been to provide peak flow, average flow, and low-flow characteristics to a variety of users. In 1993, the USGS began a study to evaluate the current network of 78 stations. The objectives of this study were to determine the adequacy of the existing network in predicting selected regional flow characteristics and to determine if providing additional streamflow-gaging stations could improve the network's ability to predict these characteristics. Alaska was divided into six distinct hydrologic regions: Arctic, Northwest, Southcentral, Southeast, Southwest, and Yukon. For each region, historical and current streamflow data were compiled. In Arctic, Northwest, and Southwest Alaska, insufficient data were available to develop regional regression equations. In these areas, proposed locations of streamflow-gaging stations were selected by using clustering techniques to define similar areas within a region and by spatial visual analysis using the precipitation, physiographic, and hydrologic unit maps of Alaska. Sufficient data existed in Southcentral and Southeast Alaska to use generalized least squares (GLS) procedures to develop regional regression equations to estimate the 50-year peak flow, annual average flow, and a low-flow statistic. GLS procedures were also used for Yukon Alaska but the results should be used with caution because the data do not have an adequate spatial distribution. Network analysis procedures were used for the Southcentral, Southeast, and Yukon regions. Network analysis indicates the reduction in the sampling error of the regional regression equation that can be obtained given different scenarios. For Alaska, a 10-year planning period was used. One scenario showed the results of continuing the current network with no additional gaging stations and another scenario showed the results

  13. Airflow and optic flow mediate antennal positioning in flying honeybees.

    PubMed

    Roy Khurana, Taruni; Sane, Sanjay P

    2016-01-01

    To maintain their speeds during navigation, insects rely on feedback from their visual and mechanosensory modalities. Although optic flow plays an essential role in speed determination, it is less reliable under conditions of low light or sparse landmarks. Under such conditions, insects rely on feedback from antennal mechanosensors but it is not clear how these inputs combine to elicit flight-related antennal behaviours. We here show that antennal movements of the honeybee, Apis mellifera, are governed by combined visual and antennal mechanosensory inputs. Frontal airflow, as experienced during forward flight, causes antennae to actively move forward as a sigmoidal function of absolute airspeed values. However, corresponding front-to-back optic flow causes antennae to move backward, as a linear function of relative optic flow, opposite the airspeed response. When combined, these inputs maintain antennal position in a state of dynamic equilibrium. PMID:27097104

  14. Airflow and optic flow mediate antennal positioning in flying honeybees

    PubMed Central

    Roy Khurana, Taruni; Sane, Sanjay P

    2016-01-01

    To maintain their speeds during navigation, insects rely on feedback from their visual and mechanosensory modalities. Although optic flow plays an essential role in speed determination, it is less reliable under conditions of low light or sparse landmarks. Under such conditions, insects rely on feedback from antennal mechanosensors but it is not clear how these inputs combine to elicit flight-related antennal behaviours. We here show that antennal movements of the honeybee, Apis mellifera, are governed by combined visual and antennal mechanosensory inputs. Frontal airflow, as experienced during forward flight, causes antennae to actively move forward as a sigmoidal function of absolute airspeed values. However, corresponding front-to-back optic flow causes antennae to move backward, as a linear function of relative optic flow, opposite the airspeed response. When combined, these inputs maintain antennal position in a state of dynamic equilibrium. DOI: http://dx.doi.org/10.7554/eLife.14449.001 PMID:27097104

  15. Indirect evaporative cooler with condensation of primary airflow

    SciTech Connect

    Vollebregt, H.J.M.; Jong, T. de

    1994-12-31

    In this paper a new application for indirect evaporative cooling is introduced. This cooling principle may be used to cool and dehumidify closed greenhouses. A prototype indirect evaporative cooler with a crossflow configuration was built and its performance was determined in an experimental facility. During tests under Dutch design conditions of the greenhouse and outside air, the plate temperature was less than the dew point of the greenhouse air, so condensation occurred. The rates of sensible and latent heat transferred from the greenhouse air by the prototype cooler were determined. Also, the influence of greenhouse and outside air conditions and airflow rates in the cooler on the enthalpy efficiency was studied. Although the amount of condensation in the prototype indirect evaporative cooler was large, the resulting climate in a closed greenhouse may be more humid than that in a conventional one.

  16. Mushrooms use convectively created airflows to disperse their spores.

    PubMed

    Dressaire, Emilie; Yamada, Lisa; Song, Boya; Roper, Marcus

    2016-03-15

    Thousands of basidiomycete fungal species rely on mushroom spores to spread across landscapes. It has long been thought that spores depend on favorable winds for dispersal--that active control of spore dispersal by the parent fungus is limited to an impulse delivered to the spores to carry them clear of the gill surface. Here we show that evaporative cooling of the air surrounding the pileus creates convective airflows capable of carrying spores at speeds of centimeters per second. Convective cells can transport spores from gaps that may be only 1 cm high and lift spores 10 cm or more into the air. This work reveals how mushrooms tolerate and even benefit from crowding and explains their high water needs. PMID:26929324

  17. Strain Gage Load Calibration of the Wing Interface Fittings for the Adaptive Compliant Trailing Edge Flap Flight Test

    NASA Technical Reports Server (NTRS)

    Miller, Eric J.; Holguin, Andrew C.; Cruz, Josue; Lokos, William A.

    2014-01-01

    This is the presentation to follow conference paper of the same name. The adaptive compliant trailing edge (ACTE) flap experiment safety of flight requires that the flap to wing interface loads be sensed and monitored in real time to ensure that the wing structural load limits are not exceeded. This paper discusses the strain gage load calibration testing and load equation derivation methodology for the ACTE interface fittings. Both the left and right wing flap interfaces will be monitored and each contains four uniquely designed and instrumented flap interface fittings. The interface hardware design and instrumentation layout are discussed. Twenty one applied test load cases were developed using the predicted in-flight loads for the ACTE experiment.

  18. The role of the olfactory recess in olfactory airflow.

    PubMed

    Eiting, Thomas P; Smith, Timothy D; Perot, J Blair; Dumont, Elizabeth R

    2014-05-15

    The olfactory recess - a blind pocket at the back of the nasal airway - is thought to play an important role in mammalian olfaction by sequestering air outside of the main airstream, thus giving odorants time to re-circulate. Several studies have shown that species with large olfactory recesses tend to have a well-developed sense of smell. However, no study has investigated how the size of the olfactory recess relates to air circulation near the olfactory epithelium. Here we used a computer model of the nasal cavity from a bat (Carollia perspicillata) to test the hypothesis that a larger olfactory recess improves olfactory airflow. We predicted that during inhalation, models with an enlarged olfactory recess would have slower rates of flow through the olfactory region (i.e. the olfactory recess plus airspace around the olfactory epithelium), while during exhalation these models would have little to no flow through the olfactory recess. To test these predictions, we experimentally modified the size of the olfactory recess while holding the rest of the morphology constant. During inhalation, we found that an enlarged olfactory recess resulted in lower rates of flow in the olfactory region. Upon exhalation, air flowed through the olfactory recess at a lower rate in the model with an enlarged olfactory recess. Taken together, these results indicate that an enlarged olfactory recess improves olfactory airflow during both inhalation and exhalation. These findings add to our growing understanding of how the morphology of the nasal cavity may relate to function in this understudied region of the skull. PMID:24577441

  19. Asthma, airflow limitation, and mortality risk in the general population

    PubMed Central

    Huang, Shuang; Vasquez, Monica M; Halonen, Marilyn; Martinez, Fernando D; Guerra, Stefano

    2015-01-01

    Asthma and chronic obstructive pulmonary disease co-exist in a significant proportion of patients. Whether asthma increases mortality risk among subjects with airflow limitation remains controversial. We used data from 2121 adult participants in the population-based TESAOD cohort. At enrollment (1972–73), participants completed questionnaires and lung function tests. Participants were categorized into four groups based on the combination of airflow limitation (AL: FEV1/FVC<70%) and physician-confirmed asthma at baseline. Vital status as of January 2011 was assessed through the National Death Index. Cox proportional hazards models were used to test differences in mortality risk across the four AL/Asthma groups. In multivariate Cox models, the AL+/Asthma+ group had a 114% increased mortality risk over the follow-up as compared with the AL-/Asthma- group (adjHR: 2.14, 1.64–2.79). The corresponding Hazard Ratios were 1.09 (0.89–1.34) and 1.34 (1.14–1.57) for the AL-/Asthma+ and AL+/Asthma- groups, respectively. Among subjects with AL, asthma was associated with increased mortality risk (1.58, 1.17–2.12). However, this increased risk was substantially reduced and no longer significant after further adjustment for baseline FEV1 levels. Similar results were obtained when AL was defined as FEV1/FVC

  20. Numerical simulation of airflow in the human nose.

    PubMed

    Weinhold, Ivo; Mlynski, Gunter

    2004-09-01

    Unobstructed air passageways as well as sufficient contact of the air stream with the mucous membrane are essential for the correct function of the nose. For that, local flow phenomena, which often cannot be captured by standard diagnostic methods, are important. We developed and validated a method for the numerical simulation of the nasal airflow. Two anatomically correct, transparent resin models of human nasal cavities, manufactured by a special casting technology, and the nasal cavities of two patients were reconstructed as Computer Aided Design models based on computed tomography (CT) scans. One of the nasal models and one clinical case represented a normal nasal anatomy, while the others were examples of pathological alterations. The velocity and pressure fields in these reconstructed cavities were calculated for the entire range of physiological nasal inspiration using commercially available computational fluid dynamics software. To validate the results rhinoresistometric data were measured and characteristic streamlines were videotaped for the resin models. The numerical results were in good agreement with the experimental data for the investigated cases. An example of a complex clinical case demonstrates the potential benefit of the developed simulation method for rhinosurgical planning. The results support the assumption that even under the specific conditions of the clinical practice the application of numerical simulation of nasal airflow phenomena may become realistic in the near future. However, important technical issues such as a completely automated reconstruction of the nasal cavity still need to be resolved before such simulations are efficient and cost effective enough to become a standard tool for the rhinologist. PMID:14652769

  1. 42 CFR 84.154 - Airflow resistance test; Type B and Type BE supplied-air respirators; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Airflow resistance test; Type B and Type BE... APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Supplied-Air Respirators § 84.154 Airflow resistance test; Type B and Type BE supplied-air respirators; minimum requirements. (a) Airflow resistance shall...

  2. 42 CFR 84.154 - Airflow resistance test; Type B and Type BE supplied-air respirators; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Airflow resistance test; Type B and Type BE... APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Supplied-Air Respirators § 84.154 Airflow resistance test; Type B and Type BE supplied-air respirators; minimum requirements. (a) Airflow resistance shall...

  3. 42 CFR 84.153 - Airflow resistance test, Type A and Type AE supplied-air respirators; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Airflow resistance test, Type A and Type AE... APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Supplied-Air Respirators § 84.153 Airflow resistance test, Type A and Type AE supplied-air respirators; minimum requirements. (a) Airflow resistance will...

  4. 42 CFR 84.154 - Airflow resistance test; Type B and Type BE supplied-air respirators; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Airflow resistance test; Type B and Type BE... APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Supplied-Air Respirators § 84.154 Airflow resistance test; Type B and Type BE supplied-air respirators; minimum requirements. (a) Airflow resistance shall...

  5. 42 CFR 84.153 - Airflow resistance test, Type A and Type AE supplied-air respirators; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Airflow resistance test, Type A and Type AE... APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Supplied-Air Respirators § 84.153 Airflow resistance test, Type A and Type AE supplied-air respirators; minimum requirements. (a) Airflow resistance will...

  6. 42 CFR 84.153 - Airflow resistance test, Type A and Type AE supplied-air respirators; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Airflow resistance test, Type A and Type AE... APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Supplied-Air Respirators § 84.153 Airflow resistance test, Type A and Type AE supplied-air respirators; minimum requirements. (a) Airflow resistance will...

  7. 42 CFR 84.154 - Airflow resistance test; Type B and Type BE supplied-air respirators; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Airflow resistance test; Type B and Type BE... APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Supplied-Air Respirators § 84.154 Airflow resistance test; Type B and Type BE supplied-air respirators; minimum requirements. (a) Airflow resistance shall...

  8. 42 CFR 84.153 - Airflow resistance test, Type A and Type AE supplied-air respirators; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Airflow resistance test, Type A and Type AE... APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Supplied-Air Respirators § 84.153 Airflow resistance test, Type A and Type AE supplied-air respirators; minimum requirements. (a) Airflow resistance will...

  9. Levels at Streamflow Gaging Stations--A CD-ROM Based Training Class

    USGS Publications Warehouse

    Nolan, K. Michael; Jacobson, Nathan; Erickson, Robert; Landon, Stanley

    2003-01-01

    Streamgages record the elevation of the water surface above some reference surface, or datum. This datum is assumed to remain unchanged throughout the life of the gage. However, the elevation of gages and their supporting structures often change over time as a result of earthmovement, floods, ice, and debris. The surveying practice of leveling is used to establish datum for new gage structures and to check for vertical movement of those structures over time. Vertical changes in gage structures can affect stage-discharge relations and, thus, could result in incorrect discharge determinations. Datum checks are used to correct stage-discharge relations and allow the USGS to document gage datum throughout the life of a gage. This training presentation describes methods currently used by the U.S. Geological Survey to run levels at gaging stations. The presentation is narrated, but you control the pace of the presentation. If the computer you are using can view 'MPEG' videos you will be able to take advantage of videos found within the presentation. A test, found at the end of the presentation, can be taken to assess how well you understood the training material. The class is registered as class SW1307 with the National Training Center of the U.S. Geologcial Survey. The presentation was developed using Macromedia Director 8.5(1) and is contained in the file 'WRI-4002.exe', which should auto-launch after the CD-ROM is inserted in the PC. The program only runs on a windows-based personal computer (PC). A sound card and speakers are necessary to take advantage of the narration that accompanies the presentation. Text of narrations is provided, if you are unable to listen to the narrations. Instructions for installing and running the presentation are included in the file ' Intro.html'. The file 'Intro.html' is on the CD-ROM containing the presentation and is available from the presentation's help menu.

  10. Visualization of the Airflow around a Life-Sized, Heated, Breathing Mannequin at Ultralow Windspeeds

    PubMed Central

    Schmees, Darrah K.; Wu, Yi-Hsuan; Vincent, James H.

    2008-01-01

    During the past two decades, there has been considerable progress in developing particle size-selective criteria for aerosol sampling and exposure assessment that relate more realistically to actual human exposures than previously. An important aspect has been the aspiration efficiency—the ‘inhalability’—with which particles enter through the nose and mouth of aerosol-exposed individuals during breathing. Most of the reported experiments to determine inhalability have been conducted in wind tunnels with life-sized, breathing mannequins, for windspeeds from 0.5 m s−1 and above. A few experiments have been reported for calm air. However, nothing has been reported for the intermediate range from 0.5 m s−1 downward, and it so happens—as we now know—that this corresponds to most industrial workplaces. The research described in this paper represents a first step toward filling this knowledge gap. It focuses on identifying the features of the airflow near the mannequin at such low windspeeds that might have important influences on the nature of particle transport, and hence on inhalability, and eventually the performances of personal aerosol samplers mounted in the breathing zone. We have carried out flow visualization experiments for the realistic range of windspeeds indicated, investigating specifically the effect of the air jet released into the freestream during expiration and the effect of the upward-moving boundary layer near the body associated with the buoyancy of air in that region as a result of heat received from the warm body. We set out to identify the combinations of conditions—external windspeed, breathing mode (nose versus mouth breathing), breathing rate and body temperature—where such factors need to be taken into account. We developed an experimental system that allowed the visualization of smoke traces, providing very good observation of how the flow was modified as conditions changed. From inspection of a large number of moving

  11. Fault tolerant attitude control for small unmanned aircraft systems equipped with an airflow sensor array.

    PubMed

    Shen, H; Xu, Y; Dickinson, B T

    2014-01-01

    Inspired by sensing strategies observed in birds and bats, a new attitude control concept of directly using real-time pressure and shear stresses has recently been studied. It was shown that with an array of onboard airflow sensors, small unmanned aircraft systems can promptly respond to airflow changes and improve flight performances. In this paper, a mapping function is proposed to compute aerodynamic moments from the real-time pressure and shear data in a practical and computationally tractable formulation. Since many microscale airflow sensors are embedded on the small unmanned aircraft system surface, it is highly possible that certain sensors may fail. Here, an adaptive control system is developed that is robust to sensor failure as well as other numerical mismatches in calculating real-time aerodynamic moments. The advantages of the proposed method are shown in the following simulation cases: (i) feedback pressure and wall shear data from a distributed array of 45 airflow sensors; (ii) 50% failure of the symmetrically distributed airflow sensor array; and (iii) failure of all the airflow sensors on one wing. It is shown that even if 50% of the airflow sensors have failures, the aircraft is still stable and able to track the attitude commands. PMID:25405953

  12. Evaluation of GE-167 Silicone Rubber (RTV) For Possible Service As A Moisture-Barrier For Certain Strain Gage Applications

    NASA Technical Reports Server (NTRS)

    Hare, David A.; Moore, Thomas C., Sr.

    2000-01-01

    The Langley Research Center uses strain gages in a wide variety of demanding test environments. Strain gage installations, depending on the testing scenario, may see high temperatures, cryogenic temperature, moisture accumulation, mechanical abuse, or any combination of these conditions. At Langley, there is often a need to provide protection for strain gages against moisture and mechanical abuse, especially when large-scale, harsh environment testing is to be encountered. This technical memorandum discusses the evaluation of a room temperature curing silicone rubber sealant manufactured by the General Electric Company for consideration as a moisture-barrier for certain strain gage installations.

  13. The Impact of Smoking on Airflow Limitation in Subjects with History of Asthma and Inactive Tuberculosis

    PubMed Central

    Kim, Hyun Jung; Baek, Seunghee; Kim, Hee Jin; Lee, Jae Seung; Oh, Yeon-Mok; Lee, Sang-Do; Lee, Sei Won

    2015-01-01

    Background Although smoking is the most important and modifiable cause of chronic obstructive pulmonary disease (COPD), other risk factors including asthma and tuberculosis (TB) are also associated. It is common for COPD patients to have more than one of these risk factors. The aims of this study were to determine the prevalence of airflow limitation (FEV1/FVC<0.7) according to the risk factors and to investigate their impact and interaction in airflow limitation. Methods From the Korean National Health and Nutrition Examination Survey between 2008 and 2012, we analyzed participants over 40 years of age by spirometry, chest radiograph and questionnaire about asthma and smoking history. Results Of 12,631 participants, 1,548 (12.3%) had airflow limitation. The prevalence of airflow limitation in smokers (≥10 pack-year), asthmatics, and those with inactive TB was 23.9%, 32.1%, and 33.6%. The prevalence increased with the number of risk factors: 86.1% had airflow limitation if they had all three risk factors. Impacts of inactive TB and asthma on airflow limitation were equivalent to 47 and 69 pack-years of smoking, respectively. Airflow limitation resulted from lower levels of smoking in those with inactive TB and asthma. A potential interaction between smoking and inactive tuberculosis in the development of airflow limitation was identified (p = 0.054). Conclusions Asthma and inactive TB lesions increase susceptibility to smoking in the development of airflow limitation. People with these risk factors should be seen as a major target population for anti-smoking campaigns to prevent COPD. PMID:25915938

  14. Improved Regression Analysis of Temperature-Dependent Strain-Gage Balance Calibration Data

    NASA Technical Reports Server (NTRS)

    Ulbrich, N.

    2015-01-01

    An improved approach is discussed that may be used to directly include first and second order temperature effects in the load prediction algorithm of a wind tunnel strain-gage balance. The improved approach was designed for the Iterative Method that fits strain-gage outputs as a function of calibration loads and uses a load iteration scheme during the wind tunnel test to predict loads from measured gage outputs. The improved approach assumes that the strain-gage balance is at a constant uniform temperature when it is calibrated and used. First, the method introduces a new independent variable for the regression analysis of the balance calibration data. The new variable is designed as the difference between the uniform temperature of the balance and a global reference temperature. This reference temperature should be the primary calibration temperature of the balance so that, if needed, a tare load iteration can be performed. Then, two temperature{dependent terms are included in the regression models of the gage outputs. They are the temperature difference itself and the square of the temperature difference. Simulated temperature{dependent data obtained from Triumph Aerospace's 2013 calibration of NASA's ARC-30K five component semi{span balance is used to illustrate the application of the improved approach.

  15. Hidden Connections between Regression Models of Strain-Gage Balance Calibration Data

    NASA Technical Reports Server (NTRS)

    Ulbrich, Norbert

    2013-01-01

    Hidden connections between regression models of wind tunnel strain-gage balance calibration data are investigated. These connections become visible whenever balance calibration data is supplied in its design format and both the Iterative and Non-Iterative Method are used to process the data. First, it is shown how the regression coefficients of the fitted balance loads of a force balance can be approximated by using the corresponding regression coefficients of the fitted strain-gage outputs. Then, data from the manual calibration of the Ames MK40 six-component force balance is chosen to illustrate how estimates of the regression coefficients of the fitted balance loads can be obtained from the regression coefficients of the fitted strain-gage outputs. The study illustrates that load predictions obtained by applying the Iterative or the Non-Iterative Method originate from two related regression solutions of the balance calibration data as long as balance loads are given in the design format of the balance, gage outputs behave highly linear, strict statistical quality metrics are used to assess regression models of the data, and regression model term combinations of the fitted loads and gage outputs can be obtained by a simple variable exchange.

  16. Care For Patients With Severe Chronic Airflow Obstruction And Respiratory Failure

    PubMed Central

    Pugsley, S. O.; Robinson, L. A.

    1979-01-01

    The successful care of patients with disorders causing chronic airflow obstruction (CAO) and potential chronic respiratory failure and pulmonary heart disease (cor pulmonale) requires the following: 1. Recognize CAO as the cause of a patient's problem. 2. Describe and measure airflow obstruction and the individual's response to it. 3. Undertake therapeutic trials to maximize airflow. 4. Teach patients monitoring skills and interventions in order to prevent acute respiratory failure and hospital admission. 5. Maintain optimism and interest in the patient's chronic illness, appreciating its impact on the total person and his daily life. PMID:21297794

  17. Data Visualization of Invisible Airflow Hazards During Helicopter Takeoff and Landing Operations

    NASA Technical Reports Server (NTRS)

    Aragon, Cecilia R.

    2004-01-01

    Many aircraft accidents each year are caused by encounters with unseen airflow hazards near the ground such as vortices, downdrafts, wind shear, microbursts, or other turbulence. While such hazards frequently pose problems to fixed-wing airplanes, they are especially dangerous to helicopters, which often have to operate in confined spaces and under operationally stressful conditions. We are developing flight-deck visualizations of airflow hazards during helicopter takeoff and landing operations, and are evaluating their effectiveness with usability studies. Our hope is.that this work will lead to the production of an airflow hazard detection system for pilots that will save lives.

  18. The mechanism of evaporation from sand columns with restricted and unrestricted water tables using deuterium under turbulent airflow conditions

    NASA Astrophysics Data System (ADS)

    Shimojima, Eiichi; Curtis, Alan A.; Turner, Jeffrey V.

    1990-09-01

    Evaporation experiments from sand columns with restricted and unrestricted water tables were carried out to elucidate the mechanism of evaporation from bare land. Turbulent airflow was applied to the exposed surface layer. The transient development of the deuterium composition of liquid water in the sand columns was measured by a microdistillation technique during the experiments. Turbulent airflow affected the evaporative process of water vapour transfer and the deuterium distribution at relatively shallow depths in the columns. The attainment of a steady evaporation rate and deuterium profile was not obtained in either the restricted or unrestricted water table cases until significant time had elapsed. In the unrestricted water table case, the transient processes of evaporation rate, depth of the evaporation front, water table depth and the development of the deuterium concentration profile show a characteristic behaviour that may be described by a similarity solution for part of the experimental duration. Significant enrichment of deuterium occurs in the liquid-vapour region and at the upper zone of the liquid region with time. The isotopic enrichment does not affect the physical process of evaporation of liquid water. Information on the transient development of the deuterium concentration profile is very useful for understanding the nature of liquid water and water vapour movement in the columns, and estimation of the depth of the evaporating front is an important index in bare land evaporation.

  19. Clip gage attachment for frictionless measurement of displacement during high-temperature mechanical testing

    DOEpatents

    Alexander, D.J.

    1994-01-04

    An attachment for placement between a test specimen and a remote clip gage extensometer providing improved fracture toughness tests of materials at elevated temperature is described. Using a cylindrical tube and axial rod in new relationship, the device transfers the displacement signal of the fracture toughness test specimen directly to a clip gage extensometer located outside the high temperature furnace. Virtually frictionless operation is assured by having the test specimen center one end of the rod in one end of the tube, while the clip gage extensometer arms center the other end of the rod in the other end of the tube. By providing positive control over both ends of both rod and tube, the attachment may be operated in orientations other than vertical. 1 figure.

  20. Clip gage attachment for frictionless measurement of displacement during high-temperature mechanical testing

    DOEpatents

    Alexander, David J.

    1994-01-01

    An attachment for placement between a test specimen and a remote clip gage extensometer providing improved fracture toughness tests of materials at elevated temperature. Using a cylindrical tube and axial rod in new relationship, the device transfers the displacement signal of the fracture toughness test specimen directly to a clip gage extensometer located outside the high temperature furnace. Virtually frictionless operation is assured by having the test specimen center one end of the rod in one end of the tube, while the clip gage extensometer arms center the other end of the rod in the other end of the tube. By providing positive control over both ends of both rod and tube, the attachment may be operated in orientations other than vertical.

  1. Static and dynamic load measurements in aerospace decelerator canopy fabrics with metal foil strain gages.

    NASA Technical Reports Server (NTRS)

    Hoffman, I. S.

    1971-01-01

    A test program was conducted to determine the feasibility of using conventional metal foil strain gages to measure load-time relationships on thin fabric membranes while these membranes were loaded under simulated aerodynamic decelerator conditions. Uniaxial and biaxial tests were made at fabric strain levels up to about 10%. Loadings were made both statically and dynamically, with the fastest load time being 0.015 second for zero to full load on uniaxial test specimens. For the biaxial tests, plane strain conditions were assumed, and by using experimentally determined strain-load relationships, principal loads were determined from the perpendicularly oriented strain-gage pairs. Although the complex stress-strain behavior of decelerator fabrics prevents the attainment of normally expected strain-gage accuracy, utilization of the techniques described can lead to meaningful measurements for the decelerator stress analyst.

  2. Detection of Bi-Directionality in Strain-Gage Balance Calibration Data

    NASA Technical Reports Server (NTRS)

    Ulbrich, Norbert

    2012-01-01

    An indicator variable was developed for both visualization and detection of bi-directionality in wind tunnel strain-gage balance calibration data. First, the calculation of the indicator variable is explained in detail. Then, a criterion is discussed that may be used to decide which gage outputs of a balance have bi- directional behavior. The result of this analysis could be used, for example, to justify the selection of certain absolute value or other even function terms in the regression model of gage outputs whenever the Iterative Method is chosen for the balance calibration data analysis. Calibration data of NASA s MK40 Task balance is analyzed to illustrate both the calculation of the indicator variable and the application of the proposed criterion. Finally, bi directionality characteristics of typical multi piece, hybrid, single piece, and semispan balances are determined and discussed.

  3. Ceramic Strain Gages for Use at Temperatures up to 1500 Celsius

    NASA Technical Reports Server (NTRS)

    Gregory, Otto; Fralick, Gustave (Technical Monitor)

    2003-01-01

    Indium-tin-oxide (ITO) thin film strain gages were successfully demonstrated at temperatures beyond 1500 C. High temperature static strain tests revealed that the piezoresistive response and electrical stability of the ceramic sensors depended on the thickness of the ITO films comprising the active strain elements. When 2.5 microns-thick ITO films were employed as the active strain elements, the piezoresistive response became unstable at temperatures above 1225 C. In contrast to this, ceramic sensors prepared with 5 microns-thick ITO were stable beyond 1430 C and sensors prepared with 8 microns-thick ITO survived more than 20 hr of operation at 1481 C. Very thick (10 microns) ITo strain gages were extremely stable and responsive at 1528 C. ESCA depth profiles confirmed that an interfacial reaction between the ITO strain gage and alumina substrate was responsible for the high temperature electrical stability observed. Similar improvements in high temperature stability were achieved by doping the active ITO strain elements with aluminum. Several Sic-Sic CMC constant strain beams were instrumented with ITO strain gages and delivered to NASA for testing. Due to the extreme surface roughness of the CMC substrates, new lithography techniques and surface preparation methods were developed. These techniques relied heavily on a combination of Sic and A12O3 cement layers to provide the necessary surface finish for efficient pattern transfer. Micro-contact printing using soft lithography and PDMS stamps was also used to successfully transfer the thin film strain gage patterns to the resist coated CMC substrates. This latter approach has considerable potential for transferring the thin film strain gage patterns to the extremely rough surfaces associated with the CMC's.

  4. Cost effectiveness of the stream-gaging program in South Carolina

    USGS Publications Warehouse

    Barker, A.C.; Wright, B.C.; Bennett, C.S.

    1985-01-01

    The cost effectiveness of the stream-gaging program in South Carolina was documented for the 1983 water yr. Data uses and funding sources were identified for the 76 continuous stream gages currently being operated in South Carolina. The budget of $422,200 for collecting and analyzing streamflow data also includes the cost of operating stage-only and crest-stage stations. The streamflow records for one stream gage can be determined by alternate, less costly methods, and should be discontinued. The remaining 75 stations should be maintained in the program for the foreseeable future. The current policy for the operation of the 75 stations including the crest-stage and stage-only stations would require a budget of $417,200/yr. The average standard error of estimation of streamflow records is 16.9% for the present budget with missing record included. However, the standard error of estimation would decrease to 8.5% if complete streamflow records could be obtained. It was shown that the average standard error of estimation of 16.9% could be obtained at the 75 sites with a budget of approximately $395,000 if the gaging resources were redistributed among the gages. A minimum budget of $383,500 is required to operate the program; a budget less than this does not permit proper service and maintenance of the gages and recorders. At the minimum budget, the average standard error is 18.6%. The maximum budget analyzed was $850,000, which resulted in an average standard error of 7.6 %. (Author 's abstract)

  5. Cost-effectiveness of the stream-gaging program in Maine; a prototype for nationwide implementation

    USGS Publications Warehouse

    Fontaine, Richard A.; Moss, M.E.; Smath, J.A.; Thomas, W.O.

    1984-01-01

    This report documents the results of a cost-effectiveness study of the stream-gaging program in Maine. Data uses and funding sources were identified for the 51 continuous stream gages currently being operated in Maine with a budget of $211,000. Three stream gages were identified as producing data no longer sufficiently needed to warrant continuing their operation. Operation of these stations should be discontinued. Data collected at three other stations were identified as having uses specific only to short-term studies; it is recommended that these stations be discontinued at the end of the data-collection phases of the studies. The remaining 45 stations should be maintained in the program for the foreseeable future. The current policy for operation of the 45-station program would require a budget of $180,300 per year. The average standard error of estimation of streamflow records is 17.7 percent. It was shown that this overall level of accuracy at the 45 sites could be maintained with a budget of approximately $170,000 if resources were redistributed among the gages. A minimum budget of $155,000 is required to operate the 45-gage program; a smaller budget would not permit proper service and maintenance of the gages and recorders. At the minimum budget, the average standard error is 25.1 percent. The maximum budget analyzed was $350,000, which resulted in an average standard error of 8.7 percent. Large parts of Maine's interior were identified as having sparse streamflow data. It was determined that this sparsity be remedied as funds become available.

  6. Evaluation of a Quartz Bourdon Pressure Gage of Wind Tunnel Mach Number Control System Application

    NASA Technical Reports Server (NTRS)

    Chapin, W. G.

    1986-01-01

    A theoretical and experimental study was undertaken to determine the feasibility of using the National Transonic Facility's high accuracy Mach number measurement system as part of a closed loop Mach number control system. The theoretical and experimental procedures described are applicable to the engineering design of pressure control systems. The results show that the dynamic response characteristics of the NTF Mach number gage (a Ruska DDR-6000 quartz absolute pressure gage) coupled to a typical length of pressure tubing were only marginally acceptable within a limited range of the facility's total pressure envelope and could not be used in the Mach number control system.

  7. Identifying dissolved organic carbon sources at a gaged headwater catchment using FDOM sensors

    NASA Astrophysics Data System (ADS)

    Malzone, J. M.; Shanley, J. B.

    2014-12-01

    The United States Geological Survey's (USGS) W-9 gage at the headwaters of Sleepers River, Vermont has been monitored for dissolved organic carbon (DOC) concentration for more than 20 years. However, the sources of this DOC during base flow and hydrologic events remain unclear. The major objectives of this research were to identify sources of DOC during storm events and to explain the observed DOC-streamflow counterclockwise hysteresis during hydrologic events. Two main hypotheses to explain hysteresis during hydrologic events were tested: (1) distant headwater wetlands are the major DOC source, which lags behind peak flow due to travel time; and (2) the entire watershed contributes to the DOC at the gage, but the response of DOC lags behind the period when groundwater contributes most to streamflow. Sources of DOC were tracked using fluorescent dissolved organic matter (FDOM) sensors in surface water and groundwater wells. Wells were installed at four depths, 0.3, 0.6, 0.9, and 1.2 m, at four sites: a peaty low-gradient riparian area near the headwaters; a mid-hillslope area on a long hillslope mid-watershed; a near-stream area on a long hillslope mid-watershed; and a low-gradient tributary confluence area just above the gage. During storm events, FDOM and hydraulic head were measured at the nested groundwater wells. Samples for DOC analysis were also taken to determine the relationship between FDOM and DOC. Results suggest that both distant sources and the greater watershed played a role in the transport of DOC to the W-9 gage. Distant peaty sources dominated during large storms and contributed the highest surface water FDOM measurements. The peak FDOM at the gage was therefore best described as a result of transport. However, export from these distant sources terminated rapidly and did not explain continued elevated FDOM at the gage. Groundwater across the watershed exhibited hysteresis analogous to that in the stream itself, with FDOM peaking as head receded

  8. Calibration characteristics of IRAD GAGE vibrating wire stressmeter at normal and high temperature. Volume 1

    SciTech Connect

    Dutta, P. K.; Hatfield, R. W.; Runstadler, Jr., P. W.

    1981-10-01

    This report describes calibration studies of the IRAD GAGE Vibrating Wire Stressmeter. The work has been performed for the University of California, Lawrence Livermore Laboratory, to understand and interpret the behavior and performance of the stressmeter in Climax granite. To help interpret the results obtained in Climax granite, the study also included calibration tests of the gage in other materials: Barre granite, aluminum, and Lucite. Stressmeter calibrations were carried out in thin rock slabs by determining the relation between the stressmeter readings and uniaxial plane stresses. Calibrations were also conducted under biaxial and triaxial stress fields.

  9. Cryogenic strain gage techniques used in force balance design for the National Transonic Facility

    NASA Technical Reports Server (NTRS)

    Ferris, A. T.

    1986-01-01

    A force balance is a strain gage transducer used in wind tunnels to measure the forces and moments on aerodynamic models. Techniques have been established for temperature-compensation of force balances to allow their use over the operating temperature range of a cryogenic wind tunnel (-190C to 60C) without thermal control. This was accomplished by using a patented strain gage matching process to minimize inherent thermal differences, and a thermal compensation procedure to reduce the remaining thermally-induced outputs to acceptable levels. A method of compensating for mechanical movement of the axial force measuring beam caused by thermally-induced stresses under transient temperatures was also included.

  10. Low temperature coefficient of resistance and high gage factor in beryllium-doped silicon

    NASA Technical Reports Server (NTRS)

    Robertson, J. B.; Littlejohn, M. A.

    1974-01-01

    The gage factor and resistivity of p-type silicon doped with beryllium was studied as a function of temperature, crystal orientation, and beryllium doping concentration. It was shown that the temperature coefficient of resistance can be varied and reduced to zero near room temperature by varying the beryllium doping level. Similarly, the magnitude of the piezoresistance gage factor for beryllium-doped silicon is slightly larger than for silicon doped with a shallow acceptor impurity such as boron, whereas the temperature coefficient of piezoresistance is about the same for material containing these two dopants. These results are discussed in terms of a model for the piezoresistance of compensated p-type silicon.

  11. Flood frequency in Texas; calculation of peak-streamflow frequency at gaging stations

    USGS Publications Warehouse

    Asquith, William H.; Slade, Raymond M., Jr.

    1995-01-01

    In 1991, the U.S. Geological Survey (USGS) began a 5-year study of floods in Texas. The study, which is being done in cooperation with the Texas Department of Transportation, uses streamflow data collected at streamflow-gaging stations to assess Texas flood characteristics. Two major objectives of the study are to determine for unregulated, rural basins (1) the most reliable method to calculate peak-streamflow frequency for Texas stations; and (2) a method to estimate peak-streamflow frequency at any Texas stream site (gaged or ungaged) using pertinent peak-streamflow information from nearby stations. This fact sheet pertains to the first objective of the study.

  12. Airflow and nanoparticle deposition in a 16-generation tracheobronchial airway model

    EPA Science Inventory

    In order to achieve both manageable simulation and local accuracy of airflow and nanoparticle deposition in a representative human tracheobronchial (TB) region, the complex airway network was decomposed into adjustable triple-bifurcation units, spreading axially and laterally. Gi...

  13. Modeling Airflow Using Subject-Specific 4DCT-Based Deformable Volumetric Lung Models.

    PubMed

    Ilegbusi, Olusegun J; Li, Zhiliang; Seyfi, Behnaz; Min, Yugang; Meeks, Sanford; Kupelian, Patrick; Santhanam, Anand P

    2012-01-01

    Lung radiotherapy is greatly benefitted when the tumor motion caused by breathing can be modeled. The aim of this paper is to present the importance of using anisotropic and subject-specific tissue elasticity for simulating the airflow inside the lungs. A computational-fluid-dynamics (CFD) based approach is presented to simulate airflow inside a subject-specific deformable lung for modeling lung tumor motion and the motion of the surrounding tissues during radiotherapy. A flow-structure interaction technique is employed that simultaneously models airflow and lung deformation. The lung is modeled as a poroelastic medium with subject-specific anisotropic poroelastic properties on a geometry, which was reconstructed from four-dimensional computed tomography (4DCT) scan datasets of humans with lung cancer. The results include the 3D anisotropic lung deformation for known airflow pattern inside the lungs. The effects of anisotropy are also presented on both the spatiotemporal volumetric lung displacement and the regional lung hysteresis. PMID:23365554

  14. Modeling Airflow Using Subject-Specific 4DCT-Based Deformable Volumetric Lung Models

    PubMed Central

    Ilegbusi, Olusegun J.; Li, Zhiliang; Seyfi, Behnaz; Min, Yugang; Meeks, Sanford; Kupelian, Patrick; Santhanam, Anand P.

    2012-01-01

    Lung radiotherapy is greatly benefitted when the tumor motion caused by breathing can be modeled. The aim of this paper is to present the importance of using anisotropic and subject-specific tissue elasticity for simulating the airflow inside the lungs. A computational-fluid-dynamics (CFD) based approach is presented to simulate airflow inside a subject-specific deformable lung for modeling lung tumor motion and the motion of the surrounding tissues during radiotherapy. A flow-structure interaction technique is employed that simultaneously models airflow and lung deformation. The lung is modeled as a poroelastic medium with subject-specific anisotropic poroelastic properties on a geometry, which was reconstructed from four-dimensional computed tomography (4DCT) scan datasets of humans with lung cancer. The results include the 3D anisotropic lung deformation for known airflow pattern inside the lungs. The effects of anisotropy are also presented on both the spatiotemporal volumetric lung displacement and the regional lung hysteresis. PMID:23365554

  15. Evaluation of circumferential airflow uniformity entering combustors from compressors. Volume 1: Discussion of data and results

    NASA Technical Reports Server (NTRS)

    Shadowen, J. H.; Egan, W. J., Jr.

    1972-01-01

    The compressor discharge airflow uniformity of two compressors from advanced engines, the J58 and F100/F401, was studied. Compressor discharge pressures and temperatures at up to 33 circumferential rake locations allowed the airflow distribution to be ascertained and computer plotted. Several flight conditions and compressor variables, i.e., inlet distortion, modified seals, etc., were analyzed. An unexpectedly high nonuniform airflow was found for both compressors. Circumferential airflow deviation differences of up to 52% from maximum to minimum were found for the J58, and up to 40% for the F100/F401. The effects of aerodynamic and thermal distortion were found to be additive. The data were analyzed for influence of exit guide vane wakes and found free of any effect. Data system errors were small in relation to the measured pressure and temperature variations.

  16. High-Resolution CFD Simulation of Airflow and Tracer Dispersion in New York City

    SciTech Connect

    Leach, M J; Chan, S T; Lundquist, J K

    2005-11-02

    In 2004, a research project--the New York City Urban Dispersion Program (NYC UDP)--was launched by the Department of Homeland Security with the goal to improve the permanent network of wind stations in and around New York City and to enhance the city's emergency response capabilities. Encompassing both field studies and computer modeling, one of the program's objectives is to improve and validate urban dispersion models using the data collected from field studies and to transfer the improved capabilities to NYC emergency agencies. The first two field studies were conducted in March and August 2005 respectively and an additional study is planned for the summer of 2006. Concurrently model simulations, using simple to sophisticated computational fluid dynamics (CFD) models, have been performed to aid the planning of field studies and also to evaluate the performance of such models. Airflow and tracer dispersion in urban areas such as NYC are extremely complicated. Some of the contributing factors are complex geometry, variable terrain, coupling between local and larger scale flows, deep canyon mixing and updrafts/downdrafts caused by large buildings, street channeling and upstream transport, roof features, and heating effects, etc. Sponsored by the U.S. Department of Energy (DOE) and Department of Homeland Security (DHS), we have developed a CFD model, FEM3MP, to address some of the above complexities. Our model is based on solving the three-dimensional, time-dependent, incompressible Navier-Stokes equations with appropriate physics for modeling airflow and dispersion in the urban environment. Also utilized in the model are finite-element discretization for effective treatment of complex geometries and a semi-implicit projection method for efficient time-integration. A description of the model can be found in Gresho and Chan (1998), Chan and Stevens (2000). Predictions from our model are continuously being verified against data from field studies, such as URBAN 2000

  17. Cigarette smoke potentiates asbestos-induced airflow abnormalities

    SciTech Connect

    Wright, J.L.; Tron, V.; Wiggs, B.; Churg, A.

    1988-01-01

    It has been suggested that exposure to both asbestos and cigarette smoke can produce worse parenchymal lung disease than exposure to asbestos alone. Using a guinea pig model of asbestos administration that produces primarily airway disease and associated airflow abnormalities, we showed previously that the combination of asbestos and smoke acts synergistically to produce more marked increases in tissue collagen, fibrosis of airway walls, and early interstitial fibrosis than are seen with asbestos alone. To investigate the functional effects of these morphological and biochemical abnormalities, pulmonary function tests for volumes and flows, including lung volumes, pressure-volume curves, and flow-volume curves, were performed. By themselves, both smoke and asbestos produced increases in total lung capacity (TLC), residual volume (RV), and functional residual capacity (FRC); the two agents together made all these changes worse than either one alone. Both smoking and asbestos moved the pressure-volume curve upward, and the effects of the two agents together were again greater than either alone. Similarly, both smoke and asbestos decreased flows, and the two agents produced more severe impairment than either one by itself. The changes in volumes, pressure-volume curve, and flows correlated with both increased thickness of small airway walls and increases in airspace size. These observations indicate that, at least in this guinea pig model, cigarette smoke can potentiate the functional consequences of asbestos exposure.

  18. Air-flow separation over unsteady breaking wind waves

    NASA Astrophysics Data System (ADS)

    Saxena, Gaurav

    2005-11-01

    In air-sea interaction processes, when considering wind stress over small-scale breaking waves, there are few direct quantitative experimental investigations into the role of air-flow separation on the interfacial momentum flux. Reul et. al, (1999), found multiple coherent patches of vorticity downwind of the crest that were strongly influenced by the geometric characteristics of the breaker. However, their breakers were generated by dispersive focusing techniques and, therefore, independent of the wind stress. We present experimental results obtained with particle image velocimetry (PIV) where moderate to strong winds directly generate unsteady small-scale breaking waves, a scenario commonly found in the open ocean. Particular attention has been devoted to capturing the spatio-temporal evolution of the air-water interface. Specifically, texture segmentation algorithms typically used for face recognition (Grey Level Co-occurrence Matrix (GLCM) and the Cross-Diagonal Texture Matrix (CDTM)) have been combined to yield robust and accurate estimates of the instantaneous breaker geometry.

  19. Evaluation of airflow patterns following procedures established by NUREG-1400

    SciTech Connect

    Fritz, Brad G.; Khan, Fenton; Mendoza, Donaldo P.

    2006-07-26

    The U.S. Nuclear Regulatory Commission's NUREG-1400 addresses many aspects of air sampling in the work place. Here, we present two detailed examples of the implementation of qualitative air flow studies at different scales using guidelines established by NUREG-1400. In one test, smoke was used to evaluate the airflow patterns within the transfer area of the 105 KE Basin, located on the Hanford Site, Richland, Washington. The purpose of the study was to determine appropriate locations for air monitoring equipment in support of sludge water pumping activities. The study revealed a stagnant layer of the air within the transfer area that made predicting movement of contamination within the transfer area difficult. Without conducting an air flow study, the stagnant layer would not have been identified, and could have resulted in locating samplers at inappropriate locations. In a second test, smoke was used to verify the effectiveness of an air space barrier curtain. The results showed that the curtain adequately separated the two air spaces. The methodology employed in each test provided sound, easy to interpret information that satisfied the requirements of each test.

  20. Evaluation of circumferential airflow uniformity entering combustors from compressors. Volume 2: Data supplement

    NASA Technical Reports Server (NTRS)

    Shadowen, J. H.; Egan, W. J., Jr.

    1972-01-01

    A study of the airflow uniformity leaving compressors and entering combustors was made using compressors from two advanced engines, the J58 and F100/F401. The data used in the analysis of each case is presented in tabular form and computer-generated profile plots. A plot of the square root of the dynamic pressure ratio, which is similar to airflow deviation, is also presented.

  1. Comprehensive assessment of meteorological conditions and airflow connectivity during HCCT-2010

    NASA Astrophysics Data System (ADS)

    Tilgner, A.; Schöne, L.; Bräuer, P.; van Pinxteren, D.; Hoffmann, E.; Spindler, G.; Styler, S. A.; Mertes, S.; Birmili, W.; Otto, R.; Merkel, M.; Weinhold, K.; Wiedensohler, A.; Deneke, H.; Schrödner, R.; Wolke, R.; Schneider, J.; Haunold, W.; Engel, A.; Wéber, A.; Herrmann, H.

    2014-09-01

    This study presents a comprehensive assessment of the meteorological conditions and atmospheric flow during the Lagrangian-type "Hill Cap Cloud Thuringia 2010" experiment (HCCT-2010), which was performed in September and October 2010 at Mt. Schmücke in the Thuringian Forest, Germany and which used observations at three measurement sites (upwind, in-cloud, and downwind) to study physical and chemical aerosol-cloud interactions. A Lagrangian-type hill cap cloud experiment requires not only suitable cloud conditions but also connected airflow conditions (i.e. representative air masses at the different measurement sites). The primary goal of the present study was to identify time periods during the 6-week duration of the experiment in which these conditions were fulfilled and therefore which are suitable for use in further data examinations. The following topics were studied in detail: (i) the general synoptic weather situations, including the mesoscale flow conditions, (ii) local meteorological conditions and (iii) local flow conditions. The latter were investigated by means of statistical analyses using best-available quasi-inert tracers, SF6 tracer experiments in the experiment area, and regional modelling. This study represents the first application of comprehensive analyses using statistical measures such as the coefficient of divergence (COD) and the cross-correlation in the context of a Lagrangian-type hill cap cloud experiment. This comprehensive examination of local flow connectivity yielded a total of 14 full-cloud events (FCEs), which are defined as periods during which all connected flow and cloud criteria for a suitable Lagrangian-type experiment were fulfilled, and 15 non-cloud events (NCEs), which are defined as periods with connected flow but no cloud at the summit site, and which can be used as reference cases. The overall evaluation of the identified FCEs provides the basis for subsequent investigations of the measured chemical and physical data

  2. Instrumentation, methods of flood-data collection and transmission, and evaluation of streamflow-gaging network in Indiana

    USGS Publications Warehouse

    Glatfelter, D.R.; Butch, G.K.

    1994-01-01

    The study results indicate that installation of streamflow-gaging stations at 15 new sites would improve collection of flood data. Instrumenting the 15 new sites plus 26 existing streamflow-gaging stations with telemetry, preferably data-collection platforms with satellite transmitters, would improve transmission of data to users of the information.

  3. Airflow resistance of heat and moisture exchange filters with and without a tracheostoma valve.

    PubMed

    Verkerke, Gijsbertus Jacob; Geertsema, Albert Anne; Schutte, Harm K

    2002-04-01

    Rehabilitation of laryngectomees has been furthered by the introduction of heat and moisture exchange (HME) filters, placed over a tracheostoma or on a tracheostoma valve (TSV). The airflow resistance of HME filters is an important factor with regard to the comfort of the patient. The goal of this study was to determine the airflow resistance (defined as the pressure drop over the device divided by the squared airflow through the device) of 4 commercially available HME filters with and without a TSV. The pressure drop over and the airflow through the devices were measured in vitro. Distinct differences among the devices were found. The mean airflow resistance of the HME filters ranged from 135 to 346 Pa x s2/L2, that of TSVs was between 66 and 297 Pa x s2/L2, and that of the combination was between 263 and 454 Pa x s2/L2. The Stom-Vent 2 HME filter and the Adeva Window TSV with an Adeva filter had the lowest airflow resistance of the devices measured in this study. PMID:11991585

  4. Airflow in the Human Nasal Passage and Sinuses of Chronic Rhinosinusitis Subjects

    PubMed Central

    Kumar, Haribalan; Jain, Ravi; Douglas, Richard G.; Tawhai, Merryn H.

    2016-01-01

    Endoscopic surgery is performed on patients with chronic inflammatory disease of the paranasal sinuses to improve sinus ventilation. Little is known about how sinus surgery affects sinonasal airflow. In this study nasal passage geometry was reconstructed from computed tomographic imaging from healthy normal, pre-operative, and post-operative subjects. Transient air flow through the nasal passage during calm breathing was simulated. Subject-specific differences in ventilation of the nasal passage were observed. Velocity magnitude at ostium was different between left and right airway. In FESS, airflow in post-surgical subjects, airflow at the maxillary sinus ostium was upto ten times higher during inspiration. In a Lothrop procedure, airflow at the frontal sinus ostium can be upto four times higher during inspiration. In both post-operative subjects, airflow at ostium was not quasi-steady. The subject-specific effect (of surgery) on sinonasal interaction evaluated through airflow simulations may have important consequences for pre- and post-surgical assessment and surgical planning, and design for improvement of the delivery efficiency of nasal therapeutics. PMID:27249219

  5. The influence of nasal airflow on respiratory and olfactory epithelial distribution in felids.

    PubMed

    Pang, Benison; Yee, Karen K; Lischka, Fritz W; Rawson, Nancy E; Haskins, Mark E; Wysocki, Charles J; Craven, Brent A; Van Valkenburgh, Blaire

    2016-06-15

    The surface area of the maxilloturbinals and fronto-ethmoturbinals is commonly used as an osteological proxy for the respiratory and the olfactory epithelium, respectively. However, this assumption does not fully account for animals with short snouts in which these two turbinal structures significantly overlap, potentially placing fronto-ethmoturbinals in the path of respiratory airflow. In these species, it is possible that anterior fronto-ethmoturbinals are covered with non-sensory (respiratory) epithelium instead of olfactory epithelium. In this study, we analyzed the distribution of olfactory and non-sensory, respiratory epithelia on the turbinals of two domestic cats (Felis catus) and a bobcat (Lynx rufus). We also conducted a computational fluid dynamics simulation of nasal airflow in the bobcat to explore the relationship between epithelial distribution and airflow patterns. The results showed that a substantial amount of respiratory airflow passes over the anterior fronto-ethmoturbinals, and that contrary to what has been observed in caniform carnivorans, much of the anterior ethmoturbinals are covered by non-sensory epithelium. This confirms that in short-snouted felids, portions of the fronto-ethmoturbinals have been recruited for respiration, and that estimates of olfactory epithelial coverage based purely on fronto-ethmoturbinal surface area will be exaggerated. The correlation between the shape of the anterior fronto-ethmoturbinals and the direction of respiratory airflow suggests that in short-snouted species, CT data alone are useful in assessing airflow patterns and epithelium distribution on the turbinals. PMID:27045093

  6. An investigation on airflow in disordered nasal cavity and its corrected models by tomographic PIV

    NASA Astrophysics Data System (ADS)

    Kim, S. K.; Chung, S. K.

    2004-06-01

    Knowledge of airflow characteristics in nasal cavities is essential to understand the physiology and pathology aspects of nasal breathing. Several studies have utilized physical models of the healthy nasal cavity to investigate the relationship between nasal anatomy and airflow. Since the final goal of these works is their contribution to the diagnosis and treatment of nasal diseases, therefore, the next step in this topic must be followed by the studies for disordered nasal cavities. In this paper, airflows in normal and abnormal nasal cavities and surgically created models, which simulate surgical treatment, are investigated experimentally by PIV. High-resolution computerized tomogram data and careful manipulation of the model surface by the ear, nose and throat doctor provide more sophisticated nasal cavity models. The correlation based correction PIV algorithm with window offset is used for PIV flow analysis. Average and RMS distributions in sagittal and coronal sections are obtained for inspiratory and expiratory nasal airflows. Comparisons in nasal airflows for both normal and abnormal cases are also examined. Airflow characteristics that are related to the abnormalities in the nasal cavity are proposed. In the case of simulations of surgical operations, velocity and RMS distributions in coronal section change locally, this may cause some difficulties in physiologic functions of noses and may hurt mucosal surface.

  7. Airflow regulation in variable-speed systems for residential HVAC applications

    SciTech Connect

    Becerra, R.C.; Beifus, B.L.

    1996-11-01

    In the majority of heating, ventilating, and air-conditioning (HVAC) systems, air is the final medium for adding or extracting heat from or to the space to be air conditioned. Air is heated by passing it over a heat transfer device called a coil, which is a heat exchanger with air on the outside and the primary heating/cooling medium (water, steam, electricity, refrigerant, etc.) on the inside. One of the major factors determining heat transfer is the airflow rate, which can be controlled by mechanical means or by controlling the speed of the fan. Centrifugal fans driven by single-speed induction motors traditionally have been used in the JVAC industry but have an airflow characteristic that depends on the static pressure seen by the system. Variable-speed systems are starting to emerge as a strong alternative to traditional systems because of their ability to match the demand of the air-conditioned space, resulting in higher efficiencies and higher comfort. System efficiency can be improved by constraining the range of airflows provided by the fan or blower system in response to system pressure, that is, by controlling the airflow over the heat exchanger. This paper presents a method to regulate airflow independent of the static pressure and without the need for airflow sensors.

  8. Measuring OutdoorAir Intake Rates Using Electronic Velocity Sensors at Louvers and Downstream of Airflow Straighteners

    SciTech Connect

    Fisk, William; Sullivan, Douglas; Cohen, Sebastian; Han, Hwataik

    2008-10-01

    Practical and accurate technologies are needed for continuously measuring and controlling outdoor air (OA) intake rates in commercial building heating, ventilating, and air conditioning (HVAC) systems. This project evaluated two new measurement approaches. Laboratory experiments determined that OA flow rates were measurable with errors generally less than 10percent using electronic air velocity probes installed between OA intake louver blades or at the outlet face of louvers. High accuracy was maintained with OA flow rates as low as 15percent of the maximum for the louvers. Thus, with this measurement approach HVAC systems do not need separate OA intakes for minimum OA supply. System calibration parameters are required for each unique combination of louver type and velocity sensor location but calibrations are not necessary for each system installation. The research also determined that the accuracy of measuring OA flow rates with velocity probes located in the duct downstream of the intake louver was not improved by installing honeycomb airflow straighteners upstream of the probes. Errors varied with type of upstream louver, were as high as 100percent, and were often greater than 25percent. In conclusion, use of electronic air velocity probes between the blades of OA intake louvers or at the outlet face of louvers is a highly promising means of accurately measuring rates of OA flow into HVAC systems. The use of electronic velocity probes downstream of airflow straighteners is less promising, at least with the relatively small OA HVAC inlet systems employed in this research.

  9. Flight-motor-driven respiratory airflow increases tracheal oxygen to nearly atmospheric level in blowflies (Calliphora vicina).

    PubMed

    Wasserthal, Lutz T

    2015-07-01

    It is widely accepted that an efficient oxygen supply and removal of CO2 in small flying insects are sufficiently performed by diffusion with open spiracles. This paper shows that in the tethered flying blowfly, gas exchange occurs by autoventilation and unidirectional airflow. The air is inspired through the mesothoracic spiracles (Sp1) during the downstroke of the wings and is expired through the metathoracic spiracles (Sp2) during the upstroke. This directed airflow through the thoracic tracheal system was documented by pre-atrial pressure measurements at the Sp1 and Sp2, revealing a sub-atmospheric mean pressure at the Sp1 and an over-atmospheric mean pressure at the Sp2. In the mesothoracic air sacs, the mean pressure is sub-atmospheric, conditioned by the only slightly open spiracles. In a split flow-through chamber experiment, the CO2 released through the Sp2 confirmed this unidirectional respiratory gas flow, implicating an inner tracheal valve. In the thoracic tracheal system, the PO2  during flight exceeds the high resting PO2  by 1-2 kPa, reaching nearly atmospheric values. In the abdominal large air sacs, the PO2  drops during flight, probably due to the accumulation of CO2. Periodic heartbeat reversals continue during flight, with a higher period frequency than at rest, supporting the transport of CO2 via the haemolymph towards the metathoracic tracheae and abdominal air sacs. PMID:26202777

  10. Strain Gage Load Calibration of the Wing Interface Fittings for the Adaptive Compliant Trailing Edge Flap Flight Test

    NASA Technical Reports Server (NTRS)

    Miller, Eric J.; Holguin, Andrew C.; Cruz, Josue; Lokos, William A.

    2014-01-01

    The safety-of-flight parameters for the Adaptive Compliant Trailing Edge (ACTE) flap experiment require that flap-to-wing interface loads be sensed and monitored in real time to ensure that the structural load limits of the wing are not exceeded. This paper discusses the strain gage load calibration testing and load equation derivation methodology for the ACTE interface fittings. Both the left and right wing flap interfaces were monitored; each contained four uniquely designed and instrumented flap interface fittings. The interface hardware design and instrumentation layout are discussed. Twenty-one applied test load cases were developed using the predicted in-flight loads. Pre-test predictions of strain gage responses were produced using finite element method models of the interface fittings. Predicted and measured test strains are presented. A load testing rig and three hydraulic jacks were used to apply combinations of shear, bending, and axial loads to the interface fittings. Hardware deflections under load were measured using photogrammetry and transducers. Due to deflections in the interface fitting hardware and test rig, finite element model techniques were used to calculate the reaction loads throughout the applied load range, taking into account the elastically-deformed geometry. The primary load equations were selected based on multiple calibration metrics. An independent set of validation cases was used to validate each derived equation. The 2-sigma residual errors for the shear loads were less than eight percent of the full-scale calibration load; the 2-sigma residual errors for the bending moment loads were less than three percent of the full-scale calibration load. The derived load equations for shear, bending, and axial loads are presented, with the calculated errors for both the calibration cases and the independent validation load cases.

  11. Silicon strain gages bonded on stainless steel using glass frit for strain sensor applications

    NASA Astrophysics Data System (ADS)

    Zhang, Zongyang; Cheng, Xingguo; Leng, Yi; Cao, Gang; Liu, Sheng

    2014-05-01

    In this paper, a steel pressure sensor using strain gages bonded on a 17-4 PH stainless steel (SS) diaphragm based on glass frit technology is proposed. The strain gages with uniform resistance are obtained by growing an epi-silicon layer on a single crystal silicon wafer using epitaxial deposition technique. The inorganic glass frits are used as the bonding material between the strain gages and the 17-4 PH SS diaphragm. Our results show that the output performances of sensors at a high temperature of 125 °C are almost equal those at room temperature, which indicates that the glass frit bonding is a good method and may lead to a significant advance in the high temperature applicability of silicon strain gage sensors. Finally, the microstructure of the cured organic adhesive and the fired glass frit are compared. It may be concluded that the defects of the cured organic adhesive deteriorate the hysteresis and repeatability errors of the sensors.

  12. Cost-effectiveness of the stream-gaging program in North Carolina

    USGS Publications Warehouse

    Mason, R.R.; Jackson, N.M.

    1985-01-01

    This report documents the results of a study of the cost-effectiveness of the stream-gaging program in North Carolina. Data uses and funding sources are identified for the 146 gaging stations currently operated in North Carolina with a budget of $777,600 (1984). As a result of the study, eleven stations are nominated for discontinuance and five for conversion from recording to partial-record status. Large parts of North Carolina 's Coastal Plain are identified as having sparse streamflow data. This sparsity should be remedied as funds become available. Efforts should also be directed toward defining the efforts of drainage improvements on local hydrology and streamflow characteristics. The average standard error of streamflow records in North Carolina is 18.6 percent. This level of accuracy could be improved without increasing cost by increasing the frequency of field visits and streamflow measurements at stations with high standard errors and reducing the frequency at stations with low standard errors. A minimum budget of $762,000 is required to operate the 146-gage program. A budget less than this does not permit proper service and maintenance of the gages and recorders. At the minimum budget, and with the optimum allocation of field visits, the average standard error is 17.6 percent.

  13. Cost-effectiveness of the stream-gaging program in New Jersey

    USGS Publications Warehouse

    Schopp, R.D.; Ulery, R.L.

    1984-01-01

    The results of a study of the cost-effectiveness of the stream-gaging program in New Jersey are documented. This study is part of a 5-year nationwide analysis undertaken by the U.S. Geological Survey to define and document the most cost-effective means of furnishing streamflow information. This report identifies the principal uses of the data and relates those uses to funding sources, applies, at selected stations, alternative less costly methods (that is flow routing, regression analysis) for furnishing the data, and defines a strategy for operating the program which minimizes uncertainty in the streamflow data for specific operating budgets. Uncertainty in streamflow data is primarily a function of the percentage of missing record and the frequency of discharge measurements. In this report, 101 continuous stream gages and 73 crest-stage or stage-only gages are analyzed. A minimum budget of $548,000 is required to operate the present stream-gaging program in New Jersey with an average standard error of 27.6 percent. The maximum budget analyzed was $650,000, which resulted in an average standard error of 17.8 percent. The 1983 budget of $569,000 resulted in a standard error of 24.9 percent under present operating policy. (USGS)

  14. Evaluation of the cost effectiveness of the 1983 stream-gaging program in Kansas

    USGS Publications Warehouse

    Medina, K.D.; Geiger, C.O.

    1984-01-01

    The results of an evaluation of the cost effectiveness of the 1983 stream-gaging program in Kansas are documented. Data uses and funding sources were identified for the 140 complete record streamflow-gaging stations operated in Kansas during 1983 with a budget of $793,780. As a result of the evaluation of the needs and uses of data from the stream-gaging program, it was found that the 140 gaging stations were needed to meet these data requirements. The average standard error of estimation of streamflow records was 20.8 percent, assuming the 1983 budget and operating schedule of 6-week interval visitations and based on 85 of the 140 stations. It was shown that this overall level of accuracy could be improved to 18.9 percent by altering the 1983 schedule of station visitations. A minimum budget of $760 ,000, with a corresponding average error of estimation of 24.9 percent, is required to operate the 1983 program. None of the stations investigated were suitable for the application of alternative methods for simulating discharge records. Improved instrumentation can have a very positive impact on streamflow uncertainties by decreasing lost record. (USGS)

  15. APPLICATION OF DISTRIBUTED MODELS FOR MANAGEMENT OF SEDIMENTS AND NUTRIENTS IN GAGED WATERSHEDS

    EPA Science Inventory

    This research evaluates a suite of distributed hydrologic, sediment, and nutrients fate and transport models by application to gaged watersheds in Iowa and Indiana. The purpose of this project is primarily three-fold. First, it evaluates the performance of the distributed models,...

  16. An evaluation of the crest-stage gage program in Louisiana

    USGS Publications Warehouse

    Herbert, R.A.; Carlson, D.D.; Wiche, G.J.

    1985-01-01

    The crest-stage gage program in Louisiana was evaluated to determine if the data were adequate for use in developing regional flood-frequency equations and to determine if any crest-stage gages could be discontinued. An abundance of data at many crest-stage stations and a lack of data for urban area and flat-slope areas indicated a need for a shift in the number, type, and locations of gages. Extensive correlations and comparisons of annual peak flows and watershed characteristics of 96 sites resulted in a reduced network of 25 stations that could potentially be used as index sites. The adequacy of the reduced network for development and verification of regional flood-frequency equations was tested by comparing a set of regional flood-frequency equations developed using data from the full network with a set developed using data from the reduced network. The results indicate that the crest-stage gage network can be reduced to 25 stations and still provide adequate information for future flood-frequency analyses. (USGS)

  17. JUSTIFICATION FOR A REDUCTION IN THE CREST-STAGE GAGE PROGRAM IN LOUISIANA.

    USGS Publications Warehouse

    Herbert, Richard A.; Carlson, Darrell D.; Wiche, Gregg J.

    1985-01-01

    The crest-stage gage program in Louisiana was evaluated to determine if the data were adequate for use in developing regional flood-frequency equations and to determine if any crest-stage gage stations could be discontinued. An abundance of data at many crest-stage gage stations and a lack of data for urban areas and flat-slope areas indicated a need for a shift in the number, type, and locations of gages. Correlations and comparisons of annual peak discharges and watershed characteristics of 96 existing stations resulted in the elimination of 72 stations and the addition of one new station, reducing the total network to 25 stations that could be used for future flood-frequency analyses. The adequacy of the reduced network for development and verification of regional flood-frequency equations was tested by comparing a set of regional flood-frequency equations developed using data from the full network with a set developed using data from the reduced network.

  18. Linking Statistically- and Physically-Based Models for Improved Streamflow Simulation in Gaged and Ungaged Areas

    NASA Astrophysics Data System (ADS)

    Lafontaine, J.; Hay, L.; Archfield, S. A.; Farmer, W. H.; Kiang, J. E.

    2014-12-01

    The U.S. Geological Survey (USGS) has developed a National Hydrologic Model (NHM) to support coordinated, comprehensive and consistent hydrologic model development, and facilitate the application of hydrologic simulations within the continental US. The portion of the NHM located within the Gulf Coastal Plains and Ozarks Landscape Conservation Cooperative (GCPO LCC) is being used to test the feasibility of improving streamflow simulations in gaged and ungaged watersheds by linking statistically- and physically-based hydrologic models. The GCPO LCC covers part or all of 12 states and 5 sub-geographies, totaling approximately 726,000 km2, and is centered on the lower Mississippi Alluvial Valley. A total of 346 USGS streamgages in the GCPO LCC region were selected to evaluate the performance of this new calibration methodology for the period 1980 to 2013. Initially, the physically-based models are calibrated to measured streamflow data to provide a baseline for comparison. An enhanced calibration procedure then is used to calibrate the physically-based models in the gaged and ungaged areas of the GCPO LCC using statistically-based estimates of streamflow. For this application, the calibration procedure is adjusted to address the limitations of the statistically generated time series to reproduce measured streamflow in gaged basins, primarily by incorporating error and bias estimates. As part of this effort, estimates of uncertainty in the model simulations are also computed for the gaged and ungaged watersheds.

  19. Loads calibrations of strain gage bridges on the DAST project Aeroelastic Research Wing (ARW-1)

    NASA Technical Reports Server (NTRS)

    Eckstrom, C. V.

    1980-01-01

    The details of and results from the procedure used to calibrate strain gage bridges for measurement of wing structural loads for the DAST project ARW-1 wing are presented. Results are in the form of loads equations and comparison of computed loads vs. actual loads for two simulated flight loading conditions.

  20. The operation and maintenance of a crest-stage gaging station

    USGS Publications Warehouse

    Friday, John

    1966-01-01

    Rigid datum controls must be maintained at the gage site throughout the period of record. Physical changes of the site resulting from flood flows or manmade alterations must be evaluated. If a drainage structure such as a culvert is part of the site features, free-flow conditions must be maintained or obstructions carefully documented.

  1. Basic Skills for Gages& Measurement. New Paradigm for Effective Workforce Skills.

    ERIC Educational Resources Information Center

    Saint Louis Community Coll., MO. Workplace Literacy Services Center.

    This document contains the materials required by individuals enrolled in a workplace course in basic skills for gages and measurements that was developed by a community college for a St. Louis (Missouri) electric company. The guide begins with an outline of the 12-day course, which covers the types, components, use, and care of the following…

  2. Nuclear Technology. Course 27: Metrology. Module 27-2, Fixed Gages, Dividers, Calipers, and Micrometers.

    ERIC Educational Resources Information Center

    Selleck, Ben; Espy, John

    This second in a series of eight modules for a course titled Metrology dscribes fixed gages, dividers, calipers, vernier and dial calipers, and micrometers. The module follows a typical format that includes the following sections: (l) introduction, (2) module prerequisites, (3) objectives, (4) notes to instructor/student, (5) subject matter, (6)…

  3. Nuclear Technology. Course 27: Metrology. Module 27-3, Gage Blocks, Mechanical Comparators and Electronic Comparators.

    ERIC Educational Resources Information Center

    Selleck, Ben; Espy, John

    This third in a series of eight modules for a course titled Metrology describes gage blocks and mechanical and electronic comparators. The module follows a typical format that includes the following sections: (1) introduction, (2) module prerequisites, (3) objectives, (4) notes to instructor/student, (5) subject matter, (6) materials needed, (7)…

  4. Iterative Strain-Gage Balance Calibration Data Analysis for Extended Independent Variable Sets

    NASA Technical Reports Server (NTRS)

    Ulbrich, Norbert Manfred

    2011-01-01

    A new method was developed that makes it possible to use an extended set of independent calibration variables for an iterative analysis of wind tunnel strain gage balance calibration data. The new method permits the application of the iterative analysis method whenever the total number of balance loads and other independent calibration variables is greater than the total number of measured strain gage outputs. Iteration equations used by the iterative analysis method have the limitation that the number of independent and dependent variables must match. The new method circumvents this limitation. It simply adds a missing dependent variable to the original data set by using an additional independent variable also as an additional dependent variable. Then, the desired solution of the regression analysis problem can be obtained that fits each gage output as a function of both the original and additional independent calibration variables. The final regression coefficients can be converted to data reduction matrix coefficients because the missing dependent variables were added to the data set without changing the regression analysis result for each gage output. Therefore, the new method still supports the application of the two load iteration equation choices that the iterative method traditionally uses for the prediction of balance loads during a wind tunnel test. An example is discussed in the paper that illustrates the application of the new method to a realistic simulation of temperature dependent calibration data set of a six component balance.

  5. UNITED STATES STREAMFLOW DATA FROM US GEOLOGICAL SURVEY STREAM-GAGING STATIONS

    EPA Science Inventory

    The U.S. Geological Survey (USGS) stream-gaging program provides streamflow data for a variety of purposes that range from current needs, such as flood forecasting, to future or long-term needs, such as detection of changes in streamflow due to human activities or global warming....

  6. A New Correction Technique for Strain-Gage Measurements Acquired in Transient-Temperature Environments

    NASA Technical Reports Server (NTRS)

    Richards, W. Lance

    1996-01-01

    Significant strain-gage errors may exist in measurements acquired in transient-temperature environments if conventional correction methods are applied. As heating or cooling rates increase, temperature gradients between the strain-gage sensor and substrate surface increase proportionally. These temperature gradients introduce strain-measurement errors that are currently neglected in both conventional strain-correction theory and practice. Therefore, the conventional correction theory has been modified to account for these errors. A new experimental method has been developed to correct strain-gage measurements acquired in environments experiencing significant temperature transients. The new correction technique has been demonstrated through a series of tests in which strain measurements were acquired for temperature-rise rates ranging from 1 to greater than 100 degrees F/sec. Strain-gage data from these tests have been corrected with both the new and conventional methods and then compared with an analysis. Results show that, for temperature-rise rates greater than 10 degrees F/sec, the strain measurements corrected with the conventional technique produced strain errors that deviated from analysis by as much as 45 percent, whereas results corrected with the new technique were in good agreement with analytical results.

  7. Rain-induced subsurface airflow and Lisse effect

    USGS Publications Warehouse

    Guo, H.; Jiao, J.J.; Weeks, E.P.

    2008-01-01

    Water-level increase after rainfall is usually indicative of rainfall recharge to groundwater. This, however, may not be true if the Lisse effect occurs. This effect represents the water-level increase in a well driven by airflow induced by an advancing wetting front during highly intensive rains. The rainwater, which may behave like a low-permeability lid, seals the ground surface so that the air pressure beneath the wetting front is increased because of air compression due to downward movement of the wetting front. A rapid and substantial rise of the water level in the well screened below water table, which bears no relationship to groundwater recharge, can be induced when various factors such as soil properties and the rain-runoff condition combine favorably. A transient, three-dimensional and variably saturated flow model was employed to study the air and groundwater flows in the soil under rain conditions. The objectives of this paper are two-fold: to evaluate the reliability of the theory of the Lisse effect presented by Weeks to predict its magnitude in modeled situations that mimic the physical complexity of real aquifers, and to conduct parametric studies on the sensitivity of the water-level rise in the well to soil properties and the rain event. The simulation results reveal that the magnitude of the Lisse effect increases with the ponding depth. Soil permeability plays a key role in generating the Lisse effect. The water-level rise in the well is delayed relative to the air-pressure rise in the unsaturated zone when the soil permeability is low, and the maximum water-level rise is less than the maximum air pressure induced by rain infiltration. The simulation also explores the sensitivity of the Lisse effect to the van Genuchten parameters and the water table depth. Copyright 2008 by the American Geophysical Union.

  8. Intratracheal Bleomycin Causes Airway Remodeling and Airflow Obstruction in Mice

    PubMed Central

    Polosukhin, Vasiliy V.; Degryse, Amber L.; Newcomb, Dawn C.; Jones, Brittany R.; Ware, Lorraine B.; Lee, Jae Woo; Loyd, James E.; Blackwell, Timothy S.; Lawson, William E.

    2014-01-01

    Introduction In addition to parenchymal fibrosis, fibrotic remodeling of the distal airways has been reported in interstitial lung diseases. Mechanisms of airway wall remodeling, which occurs in a variety of chronic lung diseases, are not well defined and current animal models are limited. Methods We quantified airway remodeling in lung sections from subjects with idiopathic pulmonary fibrosis (IPF) and controls. To investigate intratracheal bleomycin as a potential animal model for fibrotic airway remodeling, we evaluated lungs from C57BL/6 mice after bleomycin treatment by histologic scoring for fibrosis and peribronchial inflammation, morphometric evaluation of subepithelial connective tissue volume density, TUNEL assay, and immunohistochemistry for transforming growth factor β1 (TGFβ1), TGFβ2, and the fibroblast marker S100A4. Lung mechanics were determined at 3 weeks post-bleomycin. Results IPF lungs had small airway remodeling with increased bronchial wall thickness compared to controls. Similarly, bleomycin treated mice developed dose-dependent airway wall inflammation and fibrosis and greater airflow resistance after high dose bleomycin. Increased TUNEL+ bronchial epithelial cells and peribronchial inflammation were noted by 1 week, and expression of TGFβ1 and TGFβ2 and accumulation of S100A4+ fibroblasts correlated with airway remodeling in a bleomycin dose-dependent fashion. Conclusions IPF is characterized by small airway remodeling in addition to parenchymal fibrosis, a pattern also seen with intratracheal bleomycin. Bronchial remodeling from intratracheal bleomycin follows a cascade of events including epithelial cell injury, airway inflammation, pro-fibrotic cytokine expression, fibroblast accumulation, and peribronchial fibrosis. Thus, this model can be utilized to investigate mechanisms of airway remodeling. PMID:22394287

  9. Numerical investigation of wind-induced airflow and interunit dispersion characteristics in multistory residential buildings.

    PubMed

    Ai, Z T; Mak, C M; Niu, J L

    2013-10-01

    Compared with the buoyancy-dominated upward spread, the interunit dispersion of pollutants in wind-dominated conditions is expected to be more complex and multiple. The aim of this study is to investigate the wind-induced airflow and interunit pollutant dispersion in typical multistory residential buildings using computational fluid dynamics. The mathematical model used is the nonstandard k-ε model incorporated with a two-layer near-wall modification, which is validated against experiments of previous investigators. Using tracer gas technique, the reentry of exhaust air from each distinct unit to other units on the same building, under different practical conditions, is quantified, and then, the possible dispersion routes are revealed. The units on the floor immediately below the source on the windward side, and vertically above it on the leeward side, where the reentry ratios are up to 4.8% and 14.9%, respectively, should be included on the high-infection list. It is also found that the presence of balconies results in a more turbulent near-wall flow field, which in turn significantly changes the reentry characteristics. Comparison of the dispersion characteristics of the slab-like building and the more complicated building in cross (#) floorplan concludes that distinctive infectious control measures should be implemented in these two types of buildings. PMID:23495766

  10. Cost-effectiveness of the Federal stream-gaging program in Virginia

    USGS Publications Warehouse

    Carpenter, D.H.

    1985-01-01

    Data uses and funding sources were identified for the 77 continuous stream gages currently being operated in Virginia by the U.S. Geological Survey with a budget of $446,000. Two stream gages were identified as not being used sufficiently to warrant continuing their operation. Operation of these stations should be considered for discontinuation. Data collected at two other stations were identified as having uses primarily related to short-term studies; these stations should also be considered for discontinuation at the end of the data collection phases of the studies. The remaining 73 stations should be kept in the program for the foreseeable future. The current policy for operation of the 77-station program requires a budget of $446,000/yr. The average standard error of estimation of streamflow records is 10.1%. It was shown that this overall level of accuracy at the 77 sites could be maintained with a budget of $430,500 if resources were redistributed among the gages. A minimum budget of $428,500 is required to operate the 77-gage program; a smaller budget would not permit proper service and maintenance of the gages and recorders. At the minimum budget, with optimized operation, the average standard error would be 10.4%. The maximum budget analyzed was $650,000, which resulted in an average standard error of 5.5%. The study indicates that a major component of error is caused by lost or missing data. If perfect equipment were available, the standard error for the current program and budget could be reduced to 7.6%. This also can be interpreted to mean that the streamflow data have a standard error of this magnitude during times when the equipment is operating properly. (Author 's abstract)

  11. Resampling Gaged Networks to Provide Uncertainty Estimates for Daily Streamflow Predictions in Ungaged Basins

    NASA Astrophysics Data System (ADS)

    Farmer, W. H.; Over, T. M.; Vogel, R. M.; Archfield, S. A.; Kiang, J. E.

    2014-12-01

    In ungaged basins, predictions of daily streamflow are essential to responsible and effective management and design of water resources systems. Transfer-based methods are widely used for prediction in ungaged basins (PUB) within a gaged network. Such methods rely on the transfer of information from an index gage to an ungaged site. In what is known as the nearest-neighbor algorithm, the index gage is selected based on geospatial proximity. The predictions offered by any PUB method can be highly uncertain, and it is often difficult to characterize this uncertainty. In the development of predicted streamflow records, understanding the uncertainty of estimates would greatly improve water resources management in ungaged basins. It is proposed that by resampling the sites of the gaged network, with replacement, a set of equally-probable streamflow predictions can be produced for any ungaged site. For a particular day in the record, the percentiles of the distribution of the resampled, predicted streamflows can be used to estimate confidence intervals of the original daily streamflow predictions. This approach is explored in the Southeast United States with a nearest-neighbor application of non-linear spatial interpolation using flow duration curves (QPPQ), a common PUB method. Though some interval re-centering is required to ensure that the best-case prediction falls within the confidence intervals, it is shown that this technique provides a reasonable first-order approximation of prediction uncertainty. Still, the best estimated confidence intervals are shown to consistently under-estimate the nominal confidence. It is hypothesized that this interval contraction is a result of temporal and spatial correlation within the gaged network. Additionally, implications of prediction uncertainty are explored and alternative estimators are considered.

  12. In-Flight Capability for Evaluating Skin-Friction Gages and Other Near-Wall Flow Sensors

    NASA Technical Reports Server (NTRS)

    Bui, Trong T.; Pipitone, Brett J.; Krake, Keith L.; Richwine, Dave (Technical Monitor)

    2003-01-01

    An 8-in.-square boundary-layer sensor panel has been developed for in-flight evaluation of skin-friction gages and other near-wall flow sensors on the NASA Dryden Flight Research Center F-15B/Flight Test Fixture (FTF). Instrumentation on the sensor panel includes a boundary-layer rake, temperature sensors, static pressure taps, and a Preston tube. Space is also available for skin-friction gages or other near-wall flow sensors. Pretest analysis of previous F-15B/FTF flight data has identified flight conditions suitable for evaluating skin-friction gages. At subsonic Mach numbers, the boundary layer over the sensor panel closely approximates the two-dimensional (2D), law-of-the-wall turbulent boundary layer, and skin-friction estimates from the Preston tube and the rake (using the Clauser plot method) can be used to evaluate skin-friction gages. At supersonic Mach numbers, the boundary layer over the sensor panel becomes complex, and other means of measuring skin friction are needed to evaluate the accuracy of new skin-friction gages. Results from the flight test of a new rubber-damped skin-friction gage confirm that at subsonic Mach numbers, nearly 2D, law-of-the-wall turbulent boundary layers exist over the sensor panel. Sensor panel data also show that this new skin-friction gage prototype does not work in flight.

  13. Cost effective stream-gaging strategies for the Lower Colorado River basin; the Blythe field office operations

    USGS Publications Warehouse

    Moss, Marshall E.; Gilroy, Edward J.

    1980-01-01

    This report describes the theoretical developments and illustrates the applications of techniques that recently have been assembled to analyze the cost-effectiveness of federally funded stream-gaging activities in support of the Colorado River compact and subsequent adjudications. The cost effectiveness of 19 stream gages in terms of minimizing the sum of the variances of the errors of estimation of annual mean discharge is explored by means of a sequential-search optimization scheme. The search is conducted over a set of decision variables that describes the number of times that each gaging route is traveled in a year. A gage route is defined as the most expeditious circuit that is made from a field office to visit one or more stream gages and return to the office. The error variance is defined as a function of the frequency of visits to a gage by using optimal estimation theory. Currently a minimum of 12 visits per year is made to any gage. By changing to a six-visit minimum, the same total error variance can be attained for the 19 stations with a budget of 10% less than the current one. Other strategies are also explored. (USGS)

  14. Physiographic and land cover attributes of the Puget Lowland and the active streamflow gaging network, Puget Sound Basin

    USGS Publications Warehouse

    Konrad, Christopher; Sevier, Maria

    2014-01-01

    Geospatial information for the active streamflow gaging network in the Puget Sound Basin was compiled to support regional monitoring of stormwater effects to small streams. The compilation includes drainage area boundaries and physiographic and land use attributes that affect hydrologic processes. Three types of boundaries were used to tabulate attributes: Puget Sound Watershed Characterization analysis units (AU); the drainage area of active streamflow gages; and the catchments of Regional Stream Monitoring Program (RSMP) sites. The active streamflow gaging network generally includes sites that represent the ranges of attributes for lowland AUs, although there are few sites with low elevations (less than 60 meters), low precipitation (less than 1 meter year), or high stream density (greater than 5 kilometers per square kilometers). The active streamflow gaging network can serve to provide streamflow information in some AUs and RSMP sites, particularly where the streamflow gage measures streamflow generated from a part of the AU or that drains to the RSMP site, and that part of the AU or RSMP site is a significant fraction of the drainage area of the streamgage. The maximum fraction of each AU or RSMP catchment upstream of a streamflow gage and the maximum fraction of any one gaged basin in an AU or RSMP along with corresponding codes are provided in the attribute tables.

  15. Mild Airflow Limitation during N2 Sleep Increases K-complex Frequency and Slows Electroencephalographic Activity

    PubMed Central

    Nguyen, Chinh D.; Wellman, Andrew; Jordan, Amy S.; Eckert, Danny J.

    2016-01-01

    Study Objectives: To determine the effects of mild airflow limitation on K-complex frequency and morphology and electroencephalogram (EEG) spectral power. Methods: Transient reductions in continuous positive airway pressure (CPAP) during stable N2 sleep were performed to induce mild airflow limitation in 20 patients with obstructive sleep apnea (OSA) and 10 healthy controls aged 44 ± 13 y. EEG at C3 and airflow were measured in 1-min windows to quantify K-complex properties and EEG spectral power immediately before and during transient reductions in CPAP. The frequency and morphology (amplitude and latency of P200, N550 and N900 components) of K-complexes and EEG spectral power were compared between conditions. Results: During mild airflow limitation (18% reduction in peak inspiratory airflow from baseline, 0.38 ± 0.11 versus 0.31 ± 0.1 L/sec) insufficient to cause American Academy of Sleep Medicine-defined cortical arousal, K-complex frequency (9.5 ± 4.5 versus 13.7 ± 6.4 per min, P < 0.01), N550 amplitude (25 ± 3 versus 27 ± 3 μV, P < 0.01) and EEG spectral power (delta: 147 ± 48 versus 230 ± 99 μV2, P < 0.01 and theta bands: 31 ± 14 versus 34 ± 13 μV2, P < 0.01) significantly increased whereas beta band power decreased (14 ± 5 versus 11 ± 4 μV2, P < 0.01) compared to the preceding non flow-limited period on CPAP. K-complex frequency, morphology, and timing did not differ between patients and controls. Conclusion: Mild airflow limitation increases K-complex frequency, N550 amplitude, and spectral power of delta and theta bands. In addition to providing mechanistic insight into the role of mild airflow limitation on K-complex characteristics and EEG activity, these findings may have important implications for respiratory conditions in which airflow limitation during sleep is common (e.g., snoring and OSA). Citation: Nguyen CD, Wellman A, Jordan AS, Eckert DJ. Mild airflow limitation during N2 sleep increases k-complex frequency and slows

  16. Computer simulation of airflow through a multi-generation tracheobronchial conducting airway

    SciTech Connect

    Fan, B.; Cheng, Yung-Sung; Yeh, Hsu-Chi

    1995-12-01

    Knowledge of airflow patterns in the human lung is important for an analysis of lung diseases and drug delivery of aerosolized medicine for medical treatment. However, very little systematic information is available on the pattern of airflow in the lung and on how this pattern affects the deposition of toxicants in the lung, and the efficacy of aerosol drug therapy. Most previous studies have only considered the airflow through a single bifurcating airway. However, the flow in a network of more than one bifurcation is more complicated due to the effect of interrelated lung generations. Because of the variation of airway geometry and flow condition from generation to generation, a single bifurcating airway cannot be taken as a representative for the others in different generations. The flow in the network varies significantly with airway generations because of a redistribution of axial momentum by the secondary flow motions. The influence of the redistribution of flow is expected in every generation. Therefore, a systematic information of the airflow through a multi-generation tracheobronchial conducting airway is needed, and it becomes the purpose of this study. This study has provided information on airflow in a lung model which is necessary to the study of the deposition of toxicants and therapeutic aerosols.

  17. Tuberculosis associates with both airflow obstruction and low lung function: BOLD results

    PubMed Central

    Amaral, André F. S.; Coton, Sonia; Kato, Bernet; Tan, Wan C.; Studnicka, Michael; Janson, Christer; Gislason, Thorarinn; Mannino, David; Bateman, Eric D.; Buist, Sonia; Burney, Peter G. J.

    2015-01-01

    Background In small studies and cases series, a history of tuberculosis has been associated with both airflow obstruction, which is characteristic of chronic obstructive pulmonary disease, and restrictive patterns on spirometry. Objective To assess the association between a history of tuberculosis and airflow obstruction and spirometric abnormalities in adults. Methods The study was performed in adults, aged 40 and above, who took part in the multicentre cross-sectional, general population-based, Burden of Obstructive Lung Disease study, had provided acceptable post-bronchodilator spirometry measurements and information on a history of tuberculosis. The associations between a history of tuberculosis and airflow obstruction and spirometric restriction were assessed within each participating centre, and estimates combined using meta-analysis. These estimates were stratified by high and low/middle income countries, according to gross national income. Results A self-reported history of tuberculosis was associated with airflow obstruction (adjusted odds ratio = 2.51, 95% confidence interval 1.83-3.42) and spirometric restriction (adjusted odds ratio = 2.13, 95% confidence interval 1.42-3.19). Conclusion A history of tuberculosis was associated with both airflow obstruction and spirometric restriction, and should be considered as a potentially important cause of obstructive disease and low lung function, particularly where tuberculosis is common. PMID:26113680

  18. Changes in nasal airflow and heat transfer correlate with symptom improvement after surgery for nasal obstruction

    PubMed Central

    Kimbell, J.S.; Frank, D.O.; Laud, Purushottam; Garcia, G.J.M.; Rhee, J.S.

    2014-01-01

    Surgeries to correct nasal airway obstruction (NAO) often have less than desirable outcomes, partly due to the absence of an objective tool to select the most appropriate surgical approach for each patient. Computational fluid dynamics (CFD) models can be used to investigate nasal airflow, but variables need to be identified that can detect surgical changes and correlate with patient symptoms. CFD models were constructed from pre- and post-surgery computed tomography scans for 10 NAO patients showing no evidence of nasal cycling. Steady-state inspiratory airflow, nasal resistance, wall shear stress, and heat flux were computed for the main nasal cavity from nostrils to posterior nasal septum both bilaterally and unilaterally. Paired t-tests indicated that all CFD variables were significantly changed by surgery when calculated on the most obstructed side, and that airflow, nasal resistance, and heat flux were significantly changed bilaterally as well. Moderate linear correlations with patient-reported symptoms were found for airflow, heat flux, unilateral allocation of airflow, and unilateral nasal resistance as a fraction of bilateral nasal resistance when calculated on the most obstructed nasal side, suggesting that these variables may be useful for evaluating the efficacy of nasal surgery objectively. Similarity in the strengths of these correlations suggests that patient-reported symptoms may represent a constellation of effects and that these variables should be tracked concurrently during future virtual surgery planning. PMID:24063885

  19. Investigation on the nasal airflow characteristics of anterior nasal cavity stenosis

    PubMed Central

    Wang, T.; Chen, D.; Wang, P.H.; Chen, J.; Deng, J.

    2016-01-01

    We used a computational fluid dynamics (CFD) model to study the inspiratory airflow profiles of patients with anterior nasal cavity stenosis who underwent curative surgery, by comparing pre- and postoperative airflow characteristics. Twenty patients with severe anterior nasal cavity stenosis, including one case of bilateral stenosis, underwent computed tomography (CT) scans for CFD modelling. The pre- and postoperative airflow characteristics of the nasal cavity were simulated and analyzed. The narrowest area of the nasal cavity in all 20 patients was located within the nasal valve area, and the mean cross-sectional area increased from 0.39 cm2 preoperative to 0.78 cm2 postoperative (P<0.01). Meanwhile, the mean airflow velocity in the nasal valve area decreased from 6.19 m/s to 2.88 m/s (P<0.01). Surgical restoration of the nasal symmetry in the bilateral nasal cavity reduced nasal resistance in the narrow sides from 0.24 Pa.s/mL to 0.11 Pa.s/mL (P<0.01). Numerical simulation of the nasal cavity in patients with anterior nasal cavity stenosis revealed structural changes and the resultant patterns of nasal airflow. Surgery achieved balanced bilateral nasal ventilation and decreased nasal resistance in the narrow region of the nasal cavity. The correction of nasal valve stenosis is not only indispensable for reducing nasal resistance, but also the key to obtain satisfactory curative effect. PMID:27533764

  20. Investigation on the nasal airflow characteristics of anterior nasal cavity stenosis.

    PubMed

    Wang, T; Chen, D; Wang, P H; Chen, J; Deng, J

    2016-01-01

    We used a computational fluid dynamics (CFD) model to study the inspiratory airflow profiles of patients with anterior nasal cavity stenosis who underwent curative surgery, by comparing pre- and postoperative airflow characteristics. Twenty patients with severe anterior nasal cavity stenosis, including one case of bilateral stenosis, underwent computed tomography (CT) scans for CFD modelling. The pre- and postoperative airflow characteristics of the nasal cavity were simulated and analyzed. The narrowest area of the nasal cavity in all 20 patients was located within the nasal valve area, and the mean cross-sectional area increased from 0.39 cm2 preoperative to 0.78 cm2 postoperative (P<0.01). Meanwhile, the mean airflow velocity in the nasal valve area decreased from 6.19 m/s to 2.88 m/s (P<0.01). Surgical restoration of the nasal symmetry in the bilateral nasal cavity reduced nasal resistance in the narrow sides from 0.24 Pa.s/mL to 0.11 Pa.s/mL (P<0.01). Numerical simulation of the nasal cavity in patients with anterior nasal cavity stenosis revealed structural changes and the resultant patterns of nasal airflow. Surgery achieved balanced bilateral nasal ventilation and decreased nasal resistance in the narrow region of the nasal cavity. The correction of nasal valve stenosis is not only indispensable for reducing nasal resistance, but also the key to obtain satisfactory curative effect. PMID:27533764

  1. Incidence of airflow limitation in subjects 65-100 years of age.

    PubMed

    Luoto, Johannes A; Elmståhl, Sölve; Wollmer, Per; Pihlsgård, Mats

    2016-02-01

    The true incidence of chronic obstructive pulmonary disease is largely unknown, because the few longitudinal studies performed have used diagnostic criteria no longer recommended by either the European Respiratory Society or the American Thoracic Society (ATS).We studied the incidence and significance of airflow limitation in a population-based geriatric sample using both an age-dependent predicted lower limit of normal (LLN) value and a fixed-ratio spirometric criterion.Out of 2025 subjects with acceptable spirometry at baseline, 984 subjects aged 65-100 years completed a 6-year follow-up visit. Smoking habits were registered at baseline. Exclusion criteria were non-acceptable spirometry performance according to ATS criteria and inability to communicate. Airflow limitation was defined both according to forced expiratory volume in 1 s (FEV1)/forced vital capacity ratio <0.7 and airflow limitation per 1000 person-years was 28.2 using a fixed ratio and 11.7 with LLN, corresponding to a 1.41-fold higher incidence rate using a fixed ratio. The incidence increased dramatically with age when using a fixed ratio, but less so when using LLN. In addition, a sex effect was observed with the LLN criterion. LLN airflow limitation was associated with increased 5-year mortality. Presence of fixed-ratio airflow limitation in individuals classified by LLN as non-obstructive was not associated with increased mortality. PMID:26677939

  2. Cost-effectiveness of the stream-gaging program in Maryland, Delaware, and the District of Columbia

    USGS Publications Warehouse

    Carpenter, David H.; James, R.W., Jr.; Gillen, D.F.

    1987-01-01

    This report documents the results of a cost-effectiveness study of the stream-gaging program in Maryland, Delaware, and the District of Columbia. Data uses and funding sources were identified for 99 continuously operated stream gages in Maryland , Delaware, and the District of Columbia. The current operation of the program requires a budget of $465,260/year. The average standard error of estimation of streamflow records is 11.8%. It is shown that this overall level of accuracy at the 99 sites could be maintained with a budget of $461,000, if resources were redistributed among the gages. (USGS)

  3. Analysis of the streamflow-gaging station network in Ohio for effectiveness in providing regional streamflow information

    USGS Publications Warehouse

    Straub, D.E.

    1998-01-01

    The streamflow-gaging station network in Ohio was evaluated for its effectiveness in providing regional streamflow information. The analysis involved application of the principles of generalized least squares regression between streamflow and climatic and basin characteristics. Regression equations were developed for three flow characteristics: (1) the instantaneous peak flow with a 100-year recurrence interval (P100), (2) the mean annual flow (Qa), and (3) the 7-day, 10-year low flow (7Q10). All active and discontinued gaging stations with 5 or more years of unregulated-streamflow data with respect to each flow characteristic were used to develop the regression equations. The gaging-station network was evaluated for the current (1996) condition of the network and estimated conditions of various network strategies if an additional 5 and 20 years of streamflow data were collected. Any active or discontinued gaging station with (1) less than 5 years of unregulated-streamflow record, (2) previously defined basin and climatic characteristics, and (3) the potential for collection of more unregulated-streamflow record were included in the network strategies involving the additional 5 and 20 years of data. The network analysis involved use of the regression equations, in combination with location, period of record, and cost of operation, to determine the contribution of the data for each gaging station to regional streamflow information. The contribution of each gaging station was based on a cost-weighted reduction of the mean square error (average sampling-error variance) associated with each regional estimating equation. All gaging stations included in the network analysis were then ranked according to their contribution to the regional information for each flow characteristic. The predictive ability of the regression equations developed from the gaging station network could be improved for all three flow characteristics with the collection of additional streamflow data

  4. High Temperature - Thin Film Strain Gages Based on Alloys of Indium Tin Oxide

    NASA Technical Reports Server (NTRS)

    Gregory, Otto J.; Cooke, James D.; Bienkiewicz, Joseph M.

    1998-01-01

    A stable, high temperature strain gage based on reactively sputtered indium tin oxide (ITO) was demonstrated at temperatures up to 1050 C. These strain sensors exhibited relatively large, negative gage factors at room temperature and their piezoresistive response was both linear and reproducible when strained up to 700 micro-in/in. When cycled between compression and tension, these sensors also showed very little hysteresis, indicating excellent mechanical stability. Thin film strain gages based on selected ITO alloys withstood more than 50,000 strain cycles of +/- 500 micro-in/in during 180 hours of testing in air at 1000 C, with minimal drift at temperature. Drift rates as low as 0.0009%/hr at 1000 C were observed for ITO films that were annealed in nitrogen at 700 C prior to strain testing. These results compare favorably with state of the art 10 micro-m thick PdCr films deposited by NASA, where drift rates of 0.047%/hr at 1050 C were observed. Nitrogen annealing not only produced the lowest drift rates to date, but also produce the largest dynamic gage factors (G = 23.5). These wide bandgap, semiconductor strain sensors also exhibited moderately low temperature coefficients of resistance (TCR) at temperatures up to 1100 C, when tested in a nitrogen ambient. A TCR of +230 ppm/C over the temperature range 200 C < T < 500 C and a TCR of -469 ppm/C over the temperature range 600 C < T < 1100 C was observed for the films tested in nitrogen. However, the resistivity behavior changed considerably when the same films were tested in oxygen ambients. A TCR of -1560 ppm/C was obtained over the temperature range of 200 C < T < 1100 C. When similar films were protected with an overcoat or when ITO films were prepared with higher oxygen contents in the plasma, two distinct TCR's were observed. At T < 800 C, a linear TCR of -210 ppm/C was observed and at T > 800 C, a linear TCR of -2170 DDm/C was observed. The combination of a moderately low TCR and a relatively large gage

  5. Atomization of water jets and sheets in axial and swirling airflows

    NASA Technical Reports Server (NTRS)

    Ingebo, R. D.

    1977-01-01

    Axial and swirling airflows were used to break up water jets and sheets into sprays of droplets to determine the overall effects of orifice diameter, weight flow of air, and the use of an air swirler on fineness of atomization as characterized by mean drop size. A scanning radiometer was used to determine the mean drop diameter of each spray. Swirling airflows were produced with an axial combustor, 70 deg blake angle, air swirling. Water jets were injected axially upstream, axially downstream and cross stream into the airflow. In addition, pressure atomizing fuel nozzles which produced a sheet and ligament type of breakup were investigated. Increasing the weight flow rate of air or the use of an air swirling markedly reduced the spray mean drop size.

  6. Dynamic Changes in Heart Rate Variability and Nasal Airflow Resistance during Nasal Allergen Provocation Test.

    PubMed

    Seppänen, Tiina M; Alho, Olli-Pekka; Seppänen, Tapio

    2016-01-01

    Allergic rhinitis is a major chronic respiratory disease and an immunoneuronal disorder. We aimed at providing further knowledge on the function of the neural system in nasal allergic reaction. Here, a method to assess simultaneously the nasal airflow resistance and the underlying function of autonomic nervous system (ANS) is presented and used during the nasal provocation of allergic and nonallergic subjects. Continuous nasal airflow resistance and spectral heart rate variability parameters show in detail the timing and intensity differences in subjects' reactions. After the provocation, the nasal airflow resistance of allergic subjects showed a positive trend, whereas LF/HF (Low Frequency/High Frequency) ratio and LF power showed a negative trend. This could imply a gradual sympathetic withdrawal in allergic subjects after the allergen provocation. The groups differed significantly by these physiological descriptors. The proposed method opens entirely new opportunities to research accurately concomitant changes in nasal breathing function and ANS. PMID:27196870

  7. Airflow acceleration performance of asymmetric surface dielectric barrier discharge actuators at different exposed needle electrode heights

    NASA Astrophysics Data System (ADS)

    Yang, Liang; Yan, Hui-Jie; Qi, Xiao-Hua; Hua, Yue; Ren, Chun-Sheng

    2015-12-01

    The use of plasma, created by asymmetric surface dielectric barrier discharge (ASDBD), as aerodynamic actuators to control airflows, has been of widespread concern over the past decades. For the single ASDBD, the actuator performance is dependent on the geometry of actuator and the produced plasma. In this work, a new electrode configuration, i.e., a row of needle, is taken as an exposed electrode for the ASDBD plasma actuator, and the electrode height is adjustable. The effects of different electrode heights on the airflow acceleration behavior are experimentally investigated by measuring surface potential distribution, ionic wind velocity, and mean thrust force production. It is demonstrated that the airflow velocity and thrust force increase with the exposed electrode height and the best actuator performance can be obtained when the exposed electrode is adjusted to an appropriate height. The difference, as analyzed, is mainly due to the distinct plasma spatial distributions at different exposed electrode heights.

  8. Experimental investigation of effects of airflows on plasma-assisted combustion actuator characteristics

    NASA Astrophysics Data System (ADS)

    Liu, Xing-Jian; He, Li-Ming; Yu, Jin-Lu; Zhang, Hua-Lei

    2015-04-01

    The effects of the airflow on plasma-assisted combustion actuator (PACA) characteristics are studied in detail. The plasma is characterized electrically, as well as optically with a spectrometer. Our results show that the airflow has an obvious influence on the PACA characteristics. The breakdown voltage and vibrational temperature decrease, while the discharge power increases compared with the stationary airflow. The memory effect of metastable state species and the transportation characteristics of charged particles in microdischarge channel are the dominant causes for the variations of the breakdown voltage and discharge power, respectively, and the vibrational temperature calculated in this work can describe the electron energy of the dielectric barrier discharge plasma in PACA. These results offer new perspectives for the use of PACA in plasma-assisted combustion. Project supported by the National Natural Science Foundation of China (Grant Nos. 51436008, 50776100, and 51106179).

  9. Competition between pressure effects and airflow influence for the performance of plasma actuators

    SciTech Connect

    Kriegseis, J.; Barckmann, K.; Grundmann, S.; Frey, J.; Tropea, C.

    2014-05-15

    The present work addresses the combined influence of pressure variations and different airflow velocities on the discharge intensity of plasma actuators. Power consumption, plasma length, and discharge capacitance were investigated systematically for varying pressure levels (p = 0.1–1 bar) and airflow velocities (U{sub ∞}=0−100 m/s) to characterize and quantify the favorable and adverse effects on the discharge intensity. In accordance with previous reports, an increasing plasma actuator discharge intensity is observed for decreasing pressure levels. At constant pressure levels, an adverse airflow influence on the electric actuator performance is demonstrated. Despite the improved discharge intensity at lower pressure levels, the seemingly improved performance of the plasma actuators is accompanied with a more pronounced drop of the relative performance. These findings demonstrate the dependency of the (kinematic and thermodynamic) environmental conditions on the electric performance of plasma actuators, which in turn affects the control authority of plasma actuators for flow control applications.

  10. [A nonlinear multi-compartment lung model for optimization of breathing airflow pattern].

    PubMed

    Cai, Yongming; Gu, Lingyan; Chen, Fuhua

    2015-02-01

    It is difficult to select the appropriate ventilation mode in clinical mechanical ventilation. This paper presents a nonlinear multi-compartment lung model to solve the difficulty. The purpose is to optimize respiratory airflow patterns and get the minimum of the work of inspiratory phrase and lung volume acceleration, minimum of the elastic potential energy and rapidity of airflow rate changes of expiratory phrase. Sigmoidal function is used to smooth the respiratory function of nonlinear equations. The equations are established to solve nonlinear boundary conditions BVP, and finally the problem was solved with gradient descent method. Experimental results showed that lung volume and the rate of airflow after optimization had good sensitivity and convergence speed. The results provide a theoretical basis for the development of multivariable controller monitoring critically ill mechanically ventilated patients. PMID:25997262

  11. Analyzing airflow in static ice caves by using the calcFLOW method

    NASA Astrophysics Data System (ADS)

    Meyer, Christiane; Meyer, Ulrich; Pflitsch, Andreas; Maggi, Valter

    2016-04-01

    In this paper we present a method to detect airflow through ice caves and to quantify the corresponding airflow speeds by the use of temperature loggers. The time series of temperature observations at different loggers are cross-correlated. The time shift of best correlation corresponds to the travel time of the air and is used to derive the airflow speed between the loggers. We apply the method to test data observed inside Schellenberger Eishöhle (ice cave). The successful determination of airflow speeds depends on the existence of distinct temperature variations during the time span of interest. Moreover the airflow speed is assumed to be constant during the period used for the correlation analysis. Both requirements limit the applicability of the correlation analysis to determine instantaneous airflow speeds. Nevertheless the method is very helpful to characterize the general patterns of air movement and their slow temporal variations. The correlation analysis assumes a linear dependency between the correlated data. The good correlation we found for our test data confirms this assumption. We therefore in a second step estimate temperature biases and scale factors for the observed temperature variations by a least-squares adjustment. The observed phenomena, a warming and an attenuation of temperature variations, depending on the distance the air traveled inside the cave, are explained by a mixing of the inflowing air with the air inside the cave. Furthermore we test the significance of the determined parameters by a standard F test and study the sensitivity of the procedure to common manipulations of the original observations like smoothing. In the end we will give an outlook on possible applications and further development of this method.

  12. Influence of Airflow on Laboratory Storage of High Moisture Corn Stover

    SciTech Connect

    Lynn M. Wendt; Ian J. Bonner; Amber N. Hoover; Rachel M. Emerson; William A. Smith

    2014-04-01

    Storing high moisture biomass for bioenergy use is a reality in many areas of the country where wet harvest conditions and environmental factors prevent dry storage from being feasible. Aerobic storage of high moisture biomass leads to microbial degradation and self-heating, but oxygen limitation can aid in material preservation. To understand the influence of oxygen presence on high moisture biomass (50 %, wet basis), three airflow rates were tested on corn stover stored in laboratory reactors. Temperature, carbon dioxide production, dry matter loss, chemical composition, fungal abundance, pH, and organic acids were used to monitor the effects of airflow on storage conditions. The results of this work indicate that oxygen availability impacts both the duration of self-heating and the severity of dry matter loss. High airflow systems experienced the greatest initial rates of loss but a shortened microbially active period that limited total dry matter loss (19 %). Intermediate airflow had improved preservation in short-term storage compared to high airflow systems but accumulated the greatest dry matter loss over time (up to 27 %) as a result of an extended microbially active period. Low airflow systems displayed the best performance with the lowest rates of loss and total loss (10 %) in storage at 50 days. Total structural sugar levels of the stored material were preserved, although glucan enrichment and xylan loss were documented in the high and intermediate flow conditions. By understanding the role of oxygen availability on biomass storage performance, the requirements for high moisture storage solutions may begin to be experimentally defined.

  13. How much does nasal cavity morphology matter? Patterns and rates of olfactory airflow in phyllostomid bats

    PubMed Central

    Eiting, Thomas P.; Perot, J. Blair; Dumont, Elizabeth R.

    2015-01-01

    The morphology of the nasal cavity in mammals with a good sense of smell includes features that are thought to improve olfactory airflow, such as a dorsal conduit that delivers odours quickly to the olfactory mucosa, an enlarged olfactory recess at the back of the airway, and a clear separation of the olfactory and respiratory regions of the nose. The link between these features and having a good sense of smell has been established by functional examinations of a handful of distantly related mammalian species. In this paper, we provide the first detailed examination of olfactory airflow in a group of closely related species that nevertheless vary in their sense of smell. We study six species of phyllostomid bats that have different airway morphologies and foraging ecologies, which have been linked to differences in olfactory ability or reliance. We hypothesize that differences in morphology correlate with differences in the patterns and rates of airflow, which in turn are consistent with dietary differences. To compare species, we make qualitative and quantitative comparisons of the patterns and rates of airflow through the olfactory region during both inhalation and exhalation across the six species. Contrary to our expectations, we find no clear differences among species in either the patterns of airflow through the airway or in rates of flow through the olfactory region. By and large, olfactory airflow seems to be conserved across species, suggesting that morphological differences appear to be driven by other mechanical demands on the snout, such as breathing and feeding. Olfactory ability may depend on other aspects of the system, such as the neurobiological processing of odours that work within the existing morphology imposed by other functional demands on the nasal cavity. PMID:25520358

  14. The Granite Mountain Atmospheric Sciences Testbed (GMAST): A Facility for Long Term Complex Terrain Airflow Studies

    NASA Astrophysics Data System (ADS)

    Zajic, D.; Pace, J. C.; Whiteman, C. D.; Hoch, S.

    2011-12-01

    This presentation describes a new facility at Dugway Proving Ground (DPG), Utah that can be used to study airflow over complex terrain, and to evaluate how airflow over a mountain barrier affects wind patterns over adjacent flatter terrain. DPG's primary mission is to conduct testing, training, and operational assessments of chemical and biological weapon systems. These operations require very precise weather forecasts. Most test operations at DPG are conducted on fairly flat test ranges having uniform surface cover, where airflow patterns are generally well-understood. However, the DPG test ranges are located alongside large, isolated mountains, most notably Granite Mountain, Camelback Mountain, and the Cedar Mountains. Airflows generated over, or influenced by, these mountains can affect wind patterns on the test ranges. The new facility, the Granite Mountain Atmospheric Sciences Testbed, or GMAST, is designed to facilitate studies of airflow interactions with topography. This facility will benefit DPG by improving understanding of how mountain airflows interact with the test range conditions. A core infrastructure of weather sensors around and on Granite Mountain has been developed including instrumented towers and remote sensors, along with automated data collection and archival systems. GMAST is expected to be in operation for a number of years and will provide a reference domain for mountain meteorology studies, with data useful for analysts, modelers and theoreticians. Visiting scientists are encouraged to collaborate with DPG personnel to utilize this valuable scientific resource and to add further equipment and scientific designs for both short-term and long-term atmospheric studies. Several of the upcoming MATERHORN (MountAin TERrain atmospHeric mOdeling and obseRvatioNs) project field tests will be conducted at DPG, giving an example of GMAST utilization and collaboration between DPG and visiting scientists.

  15. How much does nasal cavity morphology matter? Patterns and rates of olfactory airflow in phyllostomid bats.

    PubMed

    Eiting, Thomas P; Perot, J Blair; Dumont, Elizabeth R

    2015-02-01

    The morphology of the nasal cavity in mammals with a good sense of smell includes features that are thought to improve olfactory airflow, such as a dorsal conduit that delivers odours quickly to the olfactory mucosa, an enlarged olfactory recess at the back of the airway, and a clear separation of the olfactory and respiratory regions of the nose. The link between these features and having a good sense of smell has been established by functional examinations of a handful of distantly related mammalian species. In this paper, we provide the first detailed examination of olfactory airflow in a group of closely related species that nevertheless vary in their sense of smell. We study six species of phyllostomid bats that have different airway morphologies and foraging ecologies, which have been linked to differences in olfactory ability or reliance. We hypothesize that differences in morphology correlate with differences in the patterns and rates of airflow, which in turn are consistent with dietary differences. To compare species, we make qualitative and quantitative comparisons of the patterns and rates of airflow through the olfactory region during both inhalation and exhalation across the six species. Contrary to our expectations, we find no clear differences among species in either the patterns of airflow through the airway or in rates of flow through the olfactory region. By and large, olfactory airflow seems to be conserved across species, suggesting that morphological differences appear to be driven by other mechanical demands on the snout, such as breathing and feeding. Olfactory ability may depend on other aspects of the system, such as the neurobiological processing of odours that work within the existing morphology imposed by other functional demands on the nasal cavity. PMID:25520358

  16. What is normal nasal airflow? A computational study of 22 healthy adults

    PubMed Central

    Zhao, Kai; Jiang, Jianbo

    2014-01-01

    Objective Nasal airflow is essential for functioning of the human nose. Given individual variation in nasal anatomy, there is yet no consensus what constitutes normal nasal airflow patterns. We attempt to obtain such information that is essential to differentiate disease-related variations. Methods Computational fluid dynamics (CFD) simulated nasal airflow in 22 healthy subjects during resting breathing. Streamline patterns, airflow distributions, velocity profiles, pressure, wall stress, turbulence, and vortical flow characteristics under quasi-steady state were analyzed. Patency ratings, acoustically measured minimum cross-sectional area (MCA), and rhinomanometric nasal resistance (NR) were examined for potential correlations with morphological and airflow-related variables. Results Common features across subjects included: >50% total pressure-drop reached near the inferior turbinate head; wall shear stress, NR, turbulence energy, and vorticity were lower in the turbinate than in the nasal valve region. However, location of the major flow path and coronal velocity distributions varied greatly across individuals. Surprisingly, on average, more flow passed through the middle than the inferior meatus and correlated with better patency ratings (r=-0.65, p<0.01). This middle flow percentage combined with peak post-vestibule nasal heat loss and MCA accounted for >70% of the variance in subjective patency ratings and predicted patency categories with 86% success. Nasal index correlated with forming of the anterior dorsal vortex. Expected for resting breathing, the functional impact for local and total turbulence, vorticity, and helicity was limited. As validation, rhinomanometric NR significantly correlated with CFD simulations (r=0.53, p<0.01). Conclusion Significant variations of nasal airflow found among healthy subjects; Key features may have clinically relevant applications. PMID:24664528

  17. Asbestos exposure, cigarette smoking, and airflow limitation in long-term Canadian chrysotile miners and millers

    SciTech Connect

    Begin, R.; Boileau, R.; Peloquin, S.

    1987-01-01

    To investigate further the relationships of asbestos exposure, cigarette smoking, and airflow limitation, we have obtained detailed pulmonary function tests (PFT) in 331 long-term Canadian chrysotile workers, 34 of whom were lifetime nonsmokers. Three disease categories were defined on the bases of standard diagnostic criteria, gallium-67 lung uptake, and the lung pressure-volume curve. Category A was composed of workers without changes suggestive of alveolitis or asbestosis. There were eight nonsmokers (ns), among whom we found a statistically significant 30% reduction in airflow conductance (Gus) at low lung volume, which is consistent with the concept of an asbestos airway lesion. The 85 smokers (sm) of category A had reduction of Gus at both high and low lung volumes. Category B was composed of workers without asbestosis but with evidence of asbestos alveolitis. In the six ns, Gus was significantly reduced to 50% normal at low lung volume. The 59 sm had reduction of Gus at both high and low lung volumes but less severely than sm in category A. Category C was composed of workers with asbestosis. The 20 ns had restrictive pattern of lung function, and Gus was decreased to 39% normal at 50% TLC. The 153 sm in C had airflow reduction comparable to sm in B. We concluded that asbestos exposure, which leads to asbestos airway disease, asbestos peribronchiolar alveolitis, and asbestosis, causes airflow limitation at low lung volume but does not reduce the expiratory flow rates on the flow-volume curve in lifetime nonsmokers. In the smoking asbestos workers with alveolitis or asbestosis, the major component of airflow limitation is a smoking effect. In these smoking workers, rigidity of the lung lessens airflow obstruction associated with smoking at the expense of increased work of breathing.

  18. Analyzing airflow in static ice caves by using the calcFLOW method

    NASA Astrophysics Data System (ADS)

    Meyer, C.; Meyer, U.; Pflitsch, A.; Maggi, V.

    2015-09-01

    In this paper we present a method to detect airflow through ice caves and to quantify the corresponding airflow speeds by the use of temperature loggers. The time series of temperature observations at different loggers are cross-correlated. The time shift of best correlation corresponds to the travel time of the air and is used to derive the airflow speed between the loggers. We apply the method to test data observed inside Schellenberger Eishöhle (ice cave). The successful determination of airflow speeds depends on the existence of distinct temperature variations during the time span of interest. Moreover the airflow speed is assumed to be constant during the period used for the correlation analysis. Both requirements limit the applicability of the correlation analysis to determine instantaneous airflow speeds. Nevertheless the method is very helpful to characterize the general patterns of air movement and their slow temporal variations. The correlation analysis assumes a linear dependency between the correlated data. The good correlation we found for our test data confirms this assumption. We therefore in a second step estimate temperature biases and scale factors for the observed temperature variations by a least squares adjustment. The observed phenomena, a warming and a damping of temperature variations depending on the distance the air traveled inside the cave, are explained by a mixing of the inflowing air with the air inside the cave. Furthermore we test the significance of the determined parameters by a standard F test and study the sensitivity of the procedure to common manipulations of the original observations like smoothing. In the end we will give an outlook on possible applications and further development of this method.

  19. Cost-effectiveness of the US Geological Survey stream-gaging program in Arkansas

    USGS Publications Warehouse

    Darling, M.E.; Lamb, T.E.

    1984-01-01

    This report documents the results of the cost-effectiveness of the stream-gaging program in Arkansas. Data uses and funding sources were identified for the daily-discharge stations. All daily-discharge stations were found to be in one or more data use categories, and none were candidates for alternate methods which would result in discontinuation or conversion to a partial record station. The cost for operation of daily-discharge stations and routing costs to partial record stations, crest gages, pollution control stations as well as seven recording ground-water stations was evaluated in the Kalman-Filtering Cost-Effective Resource allocation (K-CERA) analysis. This operation under current practices requires a budget of $292,150. The average standard error of estimate of streamflow record for the Arkansas District was analyzed at 33 percent.

  20. New approach for calibration and interpretation of IRAD GAGE vibrating-wire stressmeters

    SciTech Connect

    Mao, N.

    1986-05-01

    IRAD GAGE vibrating-wire stressmeters were installed in the Spent Fuel Facility at the Nevada Test Site to measure the change in in-situ stress during the Spent Fuel Test-Climax (SFT-C). This paper discusses the results of removing a cylindrical section of rock and gages as a unit through overcoring, and the subsequent post-test calibration of the stressmeters in the laboratory. The estimated in-situ stresses based on post test calibration data are quite consistent with those directly measured in nearby holes. The magnitude of stress change calculated from pre-test calibration data is generally much smaller than that estimated from post test calibration data. 11 refs., 5 figs., 2 tabs.

  1. High temperature static strain gage development contract, tasks 1 and 2

    NASA Astrophysics Data System (ADS)

    Hulse, C. O.; Bailey, R. S.; Grant, H. P.; Przybyszewski, J. S.

    1987-07-01

    Results are presented for the first two tasks to develop resistive strain gage systems for use up to 1250 K on blades and vanes in gas turbine engines under tests. The objective of these two tasks was to further improve and evaluate two static strain gage alloys identified as candidates in a previous program. Improved compositions were not found for either alloy. Further efforts on the Fe-11.9Al-10.6Cr weigth percent alloy were discontinued because of time dependent drift problems at 1250 K in air. When produced as a 6.5 micrometer thick sputtered film, the Pd-13Cr weight percent alloys is not sufficiently stable for this use in air at 1250 K and a protective overcoat system will need to be developed.

  2. Real-time estimation of rainfall fields using radar rainfall and rain gage data

    NASA Astrophysics Data System (ADS)

    Seo, D.-J.

    1998-07-01

    New attempts at real-time estimation of rainfall fields using rain gage and radar rainfall data are reported. Based on multiplicative decomposition of expectation of rainfall into conditional expectation of rainfall given raining and probability of rainfall, the estimation procedures explicitly account for both within-storm variability of rainfall and variability due to fractional coverage of rainfall. As a result, in addition to the accuracy of radar rainfall data in estimating rainfall given that rainfall is successfully detected, that in discerning rainfall from no rainfall can also be taken into account. To evaluate the estimation procedures, cross validation was performed using hourly radar rainfall data from the Tulsa, Oklahoma, Weather Surveillance Radar-1988 Doppler version (WSR-88D) and hourly rain gage data under the radar umbrella.

  3. Loads calibrations of strain gage bridges on the DAST project Aeroelastic Research Wing (ARW-2)

    NASA Technical Reports Server (NTRS)

    Eckstrom, C. V.

    1986-01-01

    Results from and details of the procedure used to calibrate strain gage bridges for measurements of wing structural loads, shear (V), bending moment (M), and torque (T), at three semispan stations on both the left and right semispans of the ARW-2 wing are presented. The ARW-2 wing has a reference area of 35 square feet, a span of 19 feet, an aspect ratio of 10.3, a midchord line sweepback angle of 25 degrees, and a taper ratio of 0.4. The ARW-2 wing was fabricated using aluminum spars and ribs covered with a fiberglass/honeycomb sandwich skin material. All strain gage bridges are mounted along with an estimate of their accuracy by means of a comparison of computed loads versus actual loads for three simulated flight conditions.

  4. Combined Load Diagram for a Wind Tunnel Strain-Gage Balance

    NASA Technical Reports Server (NTRS)

    Ulbrich, N.

    2010-01-01

    Combined Load Diagrams for Direct-Read, Force, and Moment Balances are discussed in great detail in the paper. The diagrams, if compared with a corresponding combined load plot of a balance calibration data set, may be used to visualize and interpret basic relationships between the applied balance calibration loads and the load components at the forward and aft gage of a strain-age balance. Lines of constant total force and moment are identified in the diagrams. In addition, the lines of pure force and pure moment are highlighted. Finally, lines of constant moment arm are depicted. It is also demonstrated that each quadrant of a Combined Load Diagram has specific regions where the applied total calibration force is at, between, or outside of the balance gage locations. Data from the manual calibration of a Force Balance is used to illustrate the application of a Combined Load Diagram to a realistic data set.

  5. The choice of strain gage for use in a large superconducting alternator

    SciTech Connect

    Ferrero, C.; Desogus, S.

    1982-01-01

    Electrical strain gages are investigated from ambient to liquid-helium temperatures. Experimental determination of the curves of apparent strain vs. temperature were especially considered, because of the role of thermal and mechanical stresses in a superconducting rotor in the cooling and operational phases. Commercially available Karma and modified-Karma alloy foil strain gages were used. These were either applied on the surface of supports of Cu, Al, Incar, AISI 304L, Araldite, and Nb, or embedded inside the specimen. Results are analyzed in terms of 4.2 to 7.2 range, 4.2 to 30 K range, reversal temperature, behavior with strain, and power dissipation effects. Conclusions are formulated with proposed applications to a wide range of technological items which require stress measurement and control in a narrow temperature range near 4.2 K.

  6. Utilizing Photogrammetry and Strain Gage Measurement to Characterize Pressurization of Inflatable Modules

    NASA Technical Reports Server (NTRS)

    Mohammed, Anil

    2011-01-01

    This paper focuses on integrating a large hatch penetration into inflatable modules of various constructions. This paper also compares load predictions with test measurements. The strain was measured by utilizing photogrammetric methods and strain gages mounted to select clevises that interface with the structural webbings. Bench testing showed good correlation between strain data collected from an extensometer and photogrammetric measurements, even when the material transitioned from the low load to high load strain region of the curve. The full-scale torus design module showed mixed results as well in the lower load and high strain regions. After thorough analysis of photogrammetric measurements, strain gage measurements, and predicted load, the photogrammetric measurements seem to be off by a factor of two.

  7. Utilizing Photogrammetry and Strain Gage Measurement to Characterize Pressurization of an Inflatable Module

    NASA Technical Reports Server (NTRS)

    Valle, Gerard D.; Selig, Molly; Litteken, Doug; Oliveras, Ovidio

    2012-01-01

    This paper documents the integration of a large hatch penetration into an inflatable module. This paper also documents the comparison of analytical load predictions with measured results utilizing strain measurement. Strain was measured by utilizing photogrammetric measurement and through measurement obtained from strain gages mounted to selected clevises that interface with the structural webbings. Bench testing showed good correlation between strain measurement obtained from an extensometer and photogrammetric measurement especially after the fabric has transitioned through the low load/high strain region of the curve. Test results for the full-scale torus showed mixed results in the lower load and thus lower strain regions. Overall strain, and thus load, measured by strain gages and photogrammetry tracked fairly well with analytical predictions. Methods and areas of improvements are discussed.

  8. High temperature static strain gage development contract, tasks 1 and 2

    NASA Technical Reports Server (NTRS)

    Hulse, C. O.; Bailey, R. S.; Grant, H. P.; Przybyszewski, J. S.

    1987-01-01

    Results are presented for the first two tasks to develop resistive strain gage systems for use up to 1250 K on blades and vanes in gas turbine engines under tests. The objective of these two tasks was to further improve and evaluate two static strain gage alloys identified as candidates in a previous program. Improved compositions were not found for either alloy. Further efforts on the Fe-11.9Al-10.6Cr weigth percent alloy were discontinued because of time dependent drift problems at 1250 K in air. When produced as a 6.5 micrometer thick sputtered film, the Pd-13Cr weight percent alloys is not sufficiently stable for this use in air at 1250 K and a protective overcoat system will need to be developed.

  9. Channel stability downstream from a dam assessed using aerial photographs and stream-gage information

    USGS Publications Warehouse

    Juracek, K.E.

    2000-01-01

    The stability of the Neosho River channel downstream from John Redmond Dam, in southeast Kansas, was investigated using multiple-date aerial photographs and stream-gage information. Bankfull channel width was used as the primary indicator variable to assess pre- and post-dam channel change. Five six-mile river reaches and four stream gages were used in the analysis. Results indicated that, aside from some localized channel widening, the overall channel change has been minor with little post-dam change in bankfull channel width. The lack of a pronounced postdam channel change may be attributed to a substantial reduction in the magnitude of the post-dam annual peak discharges in combination with the resistance to erosion of the bed and bank materials. Also, the channel may have been overwidened by a series of large floods that predated construction of the dam, including one with an estimated 500-year recurrence interval.

  10. Effectiveness of the streamflow-gaging network in Kentucky in providing regional streamflow information

    USGS Publications Warehouse

    Ruhl, K.J.

    1993-01-01

    This report describes the results of an analysis of the effectiveness of the strearnflow-gaging network in Kentucky in providing regional streamflow information. The data available for analysis included streamflow-gaging stations in Kentucky and selected stations in adjoining States. One phase of the analysis determined the increased effectiveness of the network if hypothetical new stations were added to it. The analysis was based on the principles of generalized least squares regression. The results indicated that new stations having small drainage areas (less than 100 square miles) produced the greatest reduction in average sampling-error variance from current conditions in the mean-flow analysis. Only stations with drainage areas ranging from 200 to 450 square miles produced a significant effect on the low-flow analysis. Data from new stations having small drainage areas (less than 100 square miles) and fairly steep slopes (25 feet per mile) would make the greatest improvement in peak-flow information.

  11. Two-dimensional airflow modeling underpredicts the wind velocity over dunes

    NASA Astrophysics Data System (ADS)

    Michelsen, Britt; Strobl, Severin; Parteli, Eric J. R.; Pöschel, Thorsten

    2015-11-01

    We investigate the average turbulent wind field over a barchan dune by means of Computational Fluid Dynamics. We find that the fractional speed-up ratio of the wind velocity over the three-dimensional barchan shape differs from the one obtained from two-dimensional calculations of the airflow over the longitudinal cut along the dune’s symmetry axis — that is, over the equivalent transverse dune of same size. This finding suggests that the modeling of the airflow over the central slice of barchan dunes is insufficient for the purpose of the quantitative description of barchan dune dynamics as three-dimensional flow effects cannot be neglected.

  12. Two-dimensional airflow modeling underpredicts the wind velocity over dunes

    PubMed Central

    Michelsen, Britt; Strobl, Severin; Parteli, Eric J. R.; Pöschel, Thorsten

    2015-01-01

    We investigate the average turbulent wind field over a barchan dune by means of Computational Fluid Dynamics. We find that the fractional speed-up ratio of the wind velocity over the three-dimensional barchan shape differs from the one obtained from two-dimensional calculations of the airflow over the longitudinal cut along the dune’s symmetry axis — that is, over the equivalent transverse dune of same size. This finding suggests that the modeling of the airflow over the central slice of barchan dunes is insufficient for the purpose of the quantitative description of barchan dune dynamics as three-dimensional flow effects cannot be neglected. PMID:26572966

  13. Research of Structure and Technology for the Micro-Machined Airflow Inclinometer

    NASA Astrophysics Data System (ADS)

    Zhang, Wei; Liu, Yu; Zhang, Fuxue

    This paper reported a sensing mechanism of carrier attitude angle with the micro-machined airflow inclinometer, it utilized fluid mechanics and related theories to design the sensitive structure, analyze and certify gas pendulum in a micro-structure hermetic chamber, We used computer aided design and simulation software MEMSPro to design sensing structure layout,and produced in MEMS processing methods. The Micro-machined airflow inclinometer installed on optical dividing head to test. Through the compensation, ± 45° can be realized Nonlinear 1% or less. The sensor has a strong anti-vibration and impact ability, a simple structure and low cost.

  14. Aerodynamic-wave break-up of liquid sheets in swirling airflows and combustor modules

    NASA Technical Reports Server (NTRS)

    Ingebo, R.

    1983-01-01

    Experimental mean drop diameter data were obtained for the atomization of liquid sheets injected axially downstream in high velocity swirling and nonswirling airflow. Conventional simplex pressure atomizing fuel nozzles and splash type fuel injectors were studied under simulated combustor inlet airflow conditions. A general empirical expression relating recirprocal mean drop diameter to airstream mass velocity was obtained and is presented. The finest degree of atomization, i.e., the highest value of the coefficient C, was obtained with swirl can combustor modules (C = 15) as compared with pressure atomizing nozzles (C = 12).

  15. Two-dimensional airflow modeling underpredicts the wind velocity over dunes.

    PubMed

    Michelsen, Britt; Strobl, Severin; Parteli, Eric J R; Pöschel, Thorsten

    2015-01-01

    We investigate the average turbulent wind field over a barchan dune by means of Computational Fluid Dynamics. We find that the fractional speed-up ratio of the wind velocity over the three-dimensional barchan shape differs from the one obtained from two-dimensional calculations of the airflow over the longitudinal cut along the dune's symmetry axis - that is, over the equivalent transverse dune of same size. This finding suggests that the modeling of the airflow over the central slice of barchan dunes is insufficient for the purpose of the quantitative description of barchan dune dynamics as three-dimensional flow effects cannot be neglected. PMID:26572966

  16. A Comparative Study of Airflow and Odorant Deposition in the Mammalian Nasal Cavity

    NASA Astrophysics Data System (ADS)

    Richter, Joseph; Rumple, Christopher; Ranslow, Allison; Quigley, Andrew; Pang, Benison; Neuberger, Thomas; Krane, Michael; van Valkenburgh, Blaire; Craven, Brent

    2013-11-01

    The complex structure of the mammalian nasal cavity provides a tortuous airflow path and a large surface area for respiratory air conditioning, filtering of inspired contaminants, and olfaction. Due to the small and contorted structure of the nasal turbinals, nasal anatomy and function remains poorly understood in most mammals. Here, we utilize high-resolution MRI scans to reconstruct anatomically-accurate models of the mammalian nasal cavity. These data are used to compare the form and function of the mammalian nose. High-fidelity computational fluid dynamics (CFD) simulations of nasal airflow and odorant deposition are presented and used to compare olfactory function across species (primate, rodent, canine, feline, ungulate).

  17. Cost effectiveness of the U.S. Geological Survey's stream-gaging program in Wisconsin

    USGS Publications Warehouse

    Walker, J.F.; Osen, L.L.; Hughes, P.E.

    1987-01-01

    A minimum budget of $510,000 is required to operate the program; a budget less than this does not permit proper service and maintenance of the gaging stations. At this minimum budget, the theoretical average standard error of instantaneous discharge is 14.4%. The maximum budget analyzed was $650,000 and resulted in an average standard of error of instantaneous discharge of 7.2%. 

  18. Real-time estimation of rainfall fields using rain gage data under fractional coverage conditions

    NASA Astrophysics Data System (ADS)

    Seo, D.-J.

    1998-07-01

    Two new attempts at optimal estimation of rainfall fields using hourly rain gage data under fractional coverage conditions are reported; (1) double optimal estimation using analogues of indicator and simple kriging to estimate probability of rainfall and rainfall amount given raining, respectively, and (2) single optimal estimation using an analogue of simple kriging to directly estimate rainfall ???. They are evaluated via cross validation using ??? from the operational network under the Tulsa, Oklahoma, WSR-88D (Weather Surveillance Radar-1988 Doppler version) umbrella.

  19. Force instrumentation for cryogenic wind tunnels using one-piece strain-gage balances

    NASA Technical Reports Server (NTRS)

    Ferris, A. T.

    1980-01-01

    The use of cryogenic temperatures in wind tunnels to achieve high Reynolds numbers has imposed a harsh operating environment on the force balance. Laboratory tests were conducted to study the effect cryogenic temperatures have on balance materials, gages, wiring, solder, adhesives, and moisture proofing. Wind tunnel tests were conducted using a one piece three component balance to verify laboratory results. These initial studies indicate that satisfactory force data can be obtained under steady state conditions.

  20. 46 CFR 32.20-20 - Liquid level gaging-T/ALL.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Liquid level gaging-T/ALL. 32.20-20 Section 32.20-20... REQUIREMENTS Equipment Installations § 32.20-20 Liquid level gaging—T/ALL. On tankships, the construction or conversion of which is started on or after July 1, 1951, a method for determining the level of the liquid...