Science.gov

Sample records for airflow resistance tests

  1. 42 CFR 84.180 - Airflow resistance tests.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Airflow resistance tests. 84.180 Section 84.180...-Purifying Particulate Respirators § 84.180 Airflow resistance tests. (a) Resistance to airflow will be... conducted in accordance with § 84.182. (b) The resistances for particulate respirators upon...

  2. 42 CFR 84.180 - Airflow resistance tests.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Airflow resistance tests. 84.180 Section 84.180...-Purifying Particulate Respirators § 84.180 Airflow resistance tests. (a) Resistance to airflow will be... conducted in accordance with § 84.182. (b) The resistances for particulate respirators upon...

  3. 42 CFR 84.180 - Airflow resistance tests.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Airflow resistance tests. 84.180 Section 84.180...-Purifying Particulate Respirators § 84.180 Airflow resistance tests. (a) Resistance to airflow will be... conducted in accordance with § 84.182. (b) The resistances for particulate respirators upon...

  4. 42 CFR 84.180 - Airflow resistance tests.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Airflow resistance tests. 84.180 Section 84.180...-Purifying Particulate Respirators § 84.180 Airflow resistance tests. (a) Resistance to airflow will be... conducted in accordance with § 84.182. (b) The resistances for particulate respirators upon...

  5. 42 CFR 84.180 - Airflow resistance tests.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Airflow resistance tests. 84.180 Section 84.180...-Purifying Particulate Respirators § 84.180 Airflow resistance tests. (a) Resistance to airflow will be... conducted in accordance with § 84.182. (b) The resistances for particulate respirators upon...

  6. 42 CFR 84.1149 - Airflow resistance tests; all dust, fume, and mist 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 tests; all dust, fume, and mist... Efficiency Respirators and Combination Gas Masks § 84.1149 Airflow resistance tests; all dust, fume, and mist respirators; minimum requirements. (a) Resistance to airflow will be measured in the facepiece,...

  7. 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... Efficiency Respirators and Combination Gas Masks § 84.1149 Airflow resistance tests; all dust, fume, and mist respirators; minimum requirements. (a) Resistance to airflow will be measured in the facepiece,...

  8. 42 CFR 84.1149 - Airflow resistance tests; all dust, fume, and mist 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 tests; all dust, fume, and mist... Efficiency Respirators and Combination Gas Masks § 84.1149 Airflow resistance tests; all dust, fume, and mist respirators; minimum requirements. (a) Resistance to airflow will be measured in the facepiece,...

  9. 42 CFR 84.1149 - Airflow resistance tests; all dust, fume, and mist 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 tests; all dust, fume, and mist... Efficiency Respirators and Combination Gas Masks § 84.1149 Airflow resistance tests; all dust, fume, and mist respirators; minimum requirements. (a) Resistance to airflow will be measured in the facepiece,...

  10. 42 CFR 84.1149 - Airflow resistance tests; all dust, fume, and mist 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 tests; all dust, fume, and mist... Efficiency Respirators and Combination Gas Masks § 84.1149 Airflow resistance tests; all dust, fume, and mist respirators; minimum requirements. (a) Resistance to airflow will be measured in the facepiece,...

  11. 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...

  12. 42 CFR 84.154 - Airflow resistance test; Type B and Type BE supplied-air 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 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...

  13. 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...

  14. 42 CFR 84.153 - Airflow resistance test, Type A and Type AE supplied-air 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 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...

  15. 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...

  16. 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...

  17. 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...

  18. 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...

  19. 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...

  20. 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...

  1. 42 CFR 84.156 - Airflow resistance test; Type C supplied-air respirator, demand class; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Airflow resistance test; Type C supplied-air... APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Supplied-Air Respirators § 84.156 Airflow resistance test; Type C supplied-air respirator, demand class; minimum requirements. (a) Inhalation resistance shall...

  2. 42 CFR 84.155 - Airflow resistance test; Type C supplied-air respirator, continuous flow class and Type CE...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Airflow resistance test; Type C supplied-air... Respirators § 84.155 Airflow resistance test; Type C supplied-air respirator, continuous flow class and Type CE supplied-air respirator; minimum requirements. The resistance to air flowing from the...

  3. 42 CFR 84.155 - Airflow resistance test; Type C supplied-air respirator, continuous flow class and Type CE...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Airflow resistance test; Type C supplied-air... Respirators § 84.155 Airflow resistance test; Type C supplied-air respirator, continuous flow class and Type CE supplied-air respirator; minimum requirements. The resistance to air flowing from the...

  4. 42 CFR 84.156 - Airflow resistance test; Type C supplied-air respirator, demand class; 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 C supplied-air... APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Supplied-Air Respirators § 84.156 Airflow resistance test; Type C supplied-air respirator, demand class; minimum requirements. (a) Inhalation resistance shall...

  5. 42 CFR 84.155 - Airflow resistance test; Type C supplied-air respirator, continuous flow class and Type CE...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Airflow resistance test; Type C supplied-air... Respirators § 84.155 Airflow resistance test; Type C supplied-air respirator, continuous flow class and Type CE supplied-air respirator; minimum requirements. The resistance to air flowing from the...

  6. 42 CFR 84.156 - Airflow resistance test; Type C supplied-air respirator, demand class; 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 C supplied-air... APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Supplied-Air Respirators § 84.156 Airflow resistance test; Type C supplied-air respirator, demand class; minimum requirements. (a) Inhalation resistance shall...

  7. 42 CFR 84.156 - Airflow resistance test; Type C supplied-air respirator, demand class; 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 C supplied-air... APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Supplied-Air Respirators § 84.156 Airflow resistance test; Type C supplied-air respirator, demand class; minimum requirements. (a) Inhalation resistance shall...

  8. 42 CFR 84.156 - Airflow resistance test; Type C supplied-air respirator, demand class; 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 C supplied-air... APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Supplied-Air Respirators § 84.156 Airflow resistance test; Type C supplied-air respirator, demand class; minimum requirements. (a) Inhalation resistance shall...

  9. 42 CFR 84.155 - Airflow resistance test; Type C supplied-air respirator, continuous flow class and Type CE...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Airflow resistance test; Type C supplied-air... Respirators § 84.155 Airflow resistance test; Type C supplied-air respirator, continuous flow class and Type CE supplied-air respirator; minimum requirements. The resistance to air flowing from the...

  10. 42 CFR 84.155 - Airflow resistance test; Type C supplied-air respirator, continuous flow class and Type CE...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Airflow resistance test; Type C supplied-air... Respirators § 84.155 Airflow resistance test; Type C supplied-air respirator, continuous flow class and Type CE supplied-air respirator; minimum requirements. The resistance to air flowing from the...

  11. 42 CFR 84.157 - Airflow resistance test; Type C supplied-air respirator, pressure-demand class; minimum...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Airflow resistance test; Type C supplied-air... ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Supplied-Air Respirators § 84.157 Airflow resistance... feet) per minute. (c) The exhalation resistance to a flow of air at a rate of 85 liters (3 cubic...

  12. 42 CFR 84.157 - Airflow resistance test; Type C supplied-air respirator, pressure-demand class; minimum...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Airflow resistance test; Type C supplied-air... ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Supplied-Air Respirators § 84.157 Airflow resistance... feet) per minute. (c) The exhalation resistance to a flow of air at a rate of 85 liters (3 cubic...

  13. 42 CFR 84.157 - Airflow resistance test; Type C supplied-air respirator, pressure-demand class; minimum...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Airflow resistance test; Type C supplied-air... ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Supplied-Air Respirators § 84.157 Airflow resistance... feet) per minute. (c) The exhalation resistance to a flow of air at a rate of 85 liters (3 cubic...

  14. 42 CFR 84.157 - Airflow resistance test; Type C supplied-air respirator, pressure-demand class; minimum...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Airflow resistance test; Type C supplied-air... ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Supplied-Air Respirators § 84.157 Airflow resistance... feet) per minute. (c) The exhalation resistance to a flow of air at a rate of 85 liters (3 cubic...

  15. Test-Retest Reliability of Respiratory Resistance Measured with the Airflow Perturbation Device

    ERIC Educational Resources Information Center

    Gallena, Sally K.; Solomon, Nancy Pearl; Johnson, Arthur T.; Vossoughi, Jafar; Tian, Wei

    2014-01-01

    Purpose: In this study, the authors aimed to determine reliability of the airflow perturbation device (APD) to measure respiratory resistance within and across sessions during resting tidal (RTB) and postexercise breathing in healthy athletes, and during RTB across trials within a session in athletes with paradoxical vocal fold motion (PVFM)…

  16. 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.

  17. Resistance to airflow through bedding materials used in infancy.

    PubMed Central

    Hatch, D J; Helms, P; Matthew, D J; Skinner, D

    1982-01-01

    Various bedding materials used in infancy, including duvets (or continental quilts), were tested for airflow using the British Standards Institution tests for pillows or fabrics. Resistance was also measured when the items were placed on a dummy infant face. Measurements were made on washed and unwashed garments, which were tested both dry and wet. Results suggest that all the bedding materials tested are safe for use even in the newborn period. The duvets produced slightly lower resistance to breathing than conventional blankets and sheets. In view of the wide variety of infant bedding fabrics it seems desirable for standard airflow performance requirements to be introduced. PMID:7092309

  18. 42 CFR 84.157 - Airflow resistance test; Type C supplied-air respirator, pressure-demand class; minimum...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... test; Type C supplied-air respirator, pressure-demand class; minimum requirements. (a) The static...) per minute shall not exceed the static pressure in the facepiece by more than 51 mm. (2 inches)...

  19. Measurement of the resistivity of porous materials with an alternating air-flow method.

    PubMed

    Dragonetti, Raffaele; Ianniello, Carmine; Romano, Rosario A

    2011-02-01

    Air-flow resistivity is a main parameter governing the acoustic behavior of porous materials for sound absorption. The international standard ISO 9053 specifies two different methods to measure the air-flow resistivity, namely a steady-state air-flow method and an alternating air-flow method. The latter is realized by the measurement of the sound pressure at 2 Hz in a small rigid volume closed partially by the test sample. This cavity is excited with a known volume-velocity sound source implemented often with a motor-driven piston oscillating with prescribed area and displacement magnitude. Measurements at 2 Hz require special instrumentation and care. The authors suggest an alternating air-flow method based on the ratio of sound pressures measured at frequencies higher than 2 Hz inside two cavities coupled through a conventional loudspeaker. The basic method showed that the imaginary part of the sound pressure ratio is useful for the evaluation of the air-flow resistance. Criteria are discussed about the choice of a frequency range suitable to perform simplified calculations with respect to the basic method. These criteria depend on the sample thickness, its nonacoustic parameters, and the measurement apparatus as well. The proposed measurement method was tested successfully with various types of acoustic materials.

  20. Turbine Air-Flow Test Rig CFD Results for Test Matrix

    NASA Technical Reports Server (NTRS)

    Wilson, Josh

    2003-01-01

    This paper presents the Turbine Air-Flow Test (TAFT) rig computational fluid dynamics (CFD) results for test matrix. The topics include: 1) TAFT Background; 2) Design Point CFD; 3) TAFT Test Plan and Test Matrix; and 4) CFD of Test Points. This paper is in viewgraph form.

  1. Relationship between Pulmonary Airflow and Resistance in Patients with Airway Narrowing Using An 1-D Network Resistance and Compliance Model

    NASA Astrophysics Data System (ADS)

    Choi, Sanghun; Choi, Jiwoong; Hoffman, Eric; Lin, Ching-Long

    2016-11-01

    To predict the proper relationship between airway resistance and regional airflow, we proposed a novel 1-D network model for airway resistance and acinar compliance. First, we extracted 1-D skeletons at inspiration images, and generated 1-D trees of CT unresolved airways with a volume filling method. We used Horsfield order with random heterogeneity to create diameters of the generated 1-D trees. We employed a resistance model that accounts for kinetic energy and viscous dissipation (Model A). The resistance model is further coupled with a regional compliance model estimated from two static images (Model B). For validation, we applied both models to a healthy subject. The results showed that Model A failed to provide airflows consistent with air volume change, whereas Model B provided airflows consistent with air volume change. Since airflows shall be regionally consistent with air volume change in patients with normal airways, Model B was validated. Then, we applied Model B to severe asthmatic subjects. The results showed that regional airflows were significantly deviated from air volume change due to airway narrowing. This implies that airway resistance plays a major role in determining regional airflows of patients with airway narrowing. Support for this study was provided, in part, by NIH Grants U01 HL114494, R01 HL094315, R01 HL112986, and S10 RR022421.

  2. Airflow resistance measurement for a layer of granular material based on the Helmholtz resonance phenomenon.

    PubMed

    Nishizu, Takahisa; Tomatsu, Eiji; Katsuno, Nakako

    2017-04-01

    A Helmholtz resonance technique was employed to predict the airflow resistance of layers of granular materials, namely glass beads, brown rice, soybean, adzuki beans, and corn kernels. Each granular sample was placed on the tube mouth of an open-type Helmholtz resonator. The resonant frequency was determined by measuring the electric impedance of a loudspeaker that was installed in the resonator and driven by a chirp signal linearly sweeping from 90 to 220 Hz for 6.0 s. For a changing sample layer thickness, the resonant frequency was measured, and the specific airflow resistance was calculated by measuring the static pressure drop required for N2 gas to flow through the layer at a constant velocity of 0.042 m/s. When the thickness of the layer was fixed, the Helmholtz resonant frequency decreased as the specific airflow resistance increased, regardless of the kind of granular material.

  3. 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.

  4. The relationship between nasal resistance to airflow and the airspace minimal cross-sectional area.

    PubMed

    Garcia, Guilherme J M; Hariri, Benjamin M; Patel, Ruchin G; Rhee, John S

    2016-06-14

    The relationship between nasal resistance (R) and airspace minimal cross-sectional area (mCSA) remains unclear. After the introduction of acoustic rhinometry, many otolaryngologists believed that mCSA measurements would correlate with subjective perception of nasal airway obstruction (NAO), and thus could provide an objective measure of nasal patency to guide therapy. However, multiple studies reported a low correlation between mCSA and subjective nasal patency, and between mCSA and R. This apparent lack of correlation between nasal form and function has been a long-standing enigma in the field of rhinology. Here we propose that nasal resistance is described by the Bernoulli Obstruction Theory. This theory predicts two flow regimes. For mCSA>Acrit, the constriction is not too severe and there is not a tight coupling between R and mCSA. In contrast, when mCSAresistance is dominated by the severe constriction and it is predicted to be inversely proportional to the minimal cross-sectional area (R∝mCSA(-1)). To test this hypothesis, computational fluid dynamics (CFD) simulations were run in 3-dimensional models based on computed tomography scans of 15 NAO patients pre- and post-surgery (i.e., 60 unilateral nasal cavities). Airspace cross-sectional areas were quantified perpendicular to airflow streamlines. Our computational results are consistent with the theory. Given that in most people mCSA>Acrit (estimated to be 0.37cm(2)), this theory suggests that airway constrictions are rarely an exclusive contributor to nasal resistance, which may explain the weak correlation between mCSA and subjective nasal patency.

  5. Airflow Research

    NASA Technical Reports Server (NTRS)

    1985-01-01

    This is an overview of research being done in laminar flow at Ames Dryden Flight Research Center and Langley Research Center. Airflow research at Ames Dryden has resulted in a special wing covering that will artificially induce laminar flow on the wing surface; this specially adapted wing is shown being tested in different flying conditions. This video also features research done at Langley in producing a chemical covering for wings that will make visible natural laminar flow and turbulent airflow patterns as they occur. Langley researchers explain possible use of this technology in supersonic flight.

  6. 42 CFR 84.122 - Breathing resistance test; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Breathing resistance test; minimum requirements. 84... Masks § 84.122 Breathing resistance test; minimum requirements. (a) Resistance to airflow will be... rate of 85 liters per minute. (b) The maximum allowable resistance requirements for gas masks are...

  7. 42 CFR 84.122 - Breathing resistance test; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Breathing resistance test; minimum requirements. 84... Masks § 84.122 Breathing resistance test; minimum requirements. (a) Resistance to airflow will be... rate of 85 liters per minute. (b) The maximum allowable resistance requirements for gas masks are...

  8. Mechanical Design of a Performance Test Rig for the Turbine Air-Flow Task (TAFT)

    NASA Technical Reports Server (NTRS)

    Forbes, John C.; Xenofos, George D.; Farrow, John L.; Tyler, Tom; Williams, Robert; Sargent, Scott; Moharos, Jozsef

    2004-01-01

    To support development of the Boeing-Rocketdyne RS84 rocket engine, a full-flow, reaction turbine geometry was integrated into the NASA-MSFC turbine air-flow test facility. A mechanical design was generated which minimized the amount of new hardware while incorporating all test and instrumentation requirements. This paper provides details of the mechanical design for this Turbine Air-Flow Task (TAFT) test rig. The mechanical design process utilized for this task included the following basic stages: Conceptual Design. Preliminary Design. Detailed Design. Baseline of Design (including Configuration Control and Drawing Revision). Fabrication. Assembly. During the design process, many lessons were learned that should benefit future test rig design projects. Of primary importance are well-defined requirements early in the design process, a thorough detailed design package, and effective communication with both the customer and the fabrication contractors.

  9. Peripheral resistance: a link between global airflow obstruction and regional ventilation distribution.

    PubMed

    Wongviriyawong, C; Harris, R S; Greenblatt, E; Winkler, T; Venegas, J G

    2013-02-15

    Airflow obstruction and heterogeneities in airway constriction and ventilation distribution are well-described prominent features of asthma. However, the mechanistic link between these global and regional features has not been well defined. We speculate that peripheral airway resistance (R(p)) may provide such a link. Structural and functional parameters are estimated from PET and HRCT images of asthmatic (AS) and nonasthmatic (NA) subjects measured at baseline (BASE) and post-methacholine challenge (POST). Conductances of 35 anatomically defined proximal airways are estimated from airway geometry obtained from high-resolution computed tomography (HRCT) images. Compliances of sublobar regions subtended by 19 most distal airways are estimated from changes in regional gas volume between two lung volumes. Specific ventilations (sV) of these sublobar regions are evaluated from 13NN-washout PET scans. For each pathway connecting the trachea to sublobar region, values of R(p) required to explain the sV distribution and global airflow obstruction are computed. Results show that R(p) is highly heterogeneous within each subject, but has average values consistent with global values in the literature. The contribution of R(p) to total pathway resistance (R(T)) increased substantially for POST (P < 0.0001). The fraction R(p)/R(T) was higher in AS than NA at POST (P < 0.0001) but similar at BASE (range: 0.960-0.997, median: 0.990). For POST, R(p)/R(T) range was 0.979-0.999 (NA) and 0.981-0.995 (AS). This approach allows for estimations of peripheral airway resistance within anatomically defined sublobar regions in vivo human lungs and may be used to evaluate peripheral effects of therapy in a subject specific manner.

  10. 42 CFR 84.122 - Breathing resistance test; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Breathing resistance test; minimum requirements. 84... Masks § 84.122 Breathing resistance test; minimum requirements. (a) Resistance to airflow will be measured in the facepiece or mouthpiece of a gas mask mounted on a breathing machine both before and...

  11. 42 CFR 84.90 - Breathing resistance test; inhalation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Breathing resistance test; inhalation. 84.90...-Contained Breathing Apparatus § 84.90 Breathing resistance test; inhalation. (a) Resistance to inhalation airflow will be measured in the facepiece or mouthpiece while the apparatus is operated by a...

  12. 42 CFR 84.122 - Breathing resistance test; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Breathing resistance test; minimum requirements. 84... Masks § 84.122 Breathing resistance test; minimum requirements. (a) Resistance to airflow will be measured in the facepiece or mouthpiece of a gas mask mounted on a breathing machine both before and...

  13. 42 CFR 84.122 - Breathing resistance test; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Breathing resistance test; minimum requirements. 84... Masks § 84.122 Breathing resistance test; minimum requirements. (a) Resistance to airflow will be measured in the facepiece or mouthpiece of a gas mask mounted on a breathing machine both before and...

  14. 42 CFR 84.90 - Breathing resistance test; inhalation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Breathing resistance test; inhalation. 84.90...-Contained Breathing Apparatus § 84.90 Breathing resistance test; inhalation. (a) Resistance to inhalation airflow will be measured in the facepiece or mouthpiece while the apparatus is operated by a...

  15. 42 CFR 84.90 - Breathing resistance test; inhalation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Breathing resistance test; inhalation. 84.90...-Contained Breathing Apparatus § 84.90 Breathing resistance test; inhalation. (a) Resistance to inhalation airflow will be measured in the facepiece or mouthpiece while the apparatus is operated by a...

  16. Airflow induced by pumping tests in unconfined aquifer with a low-permeability cap

    NASA Astrophysics Data System (ADS)

    Jiao, Jiu Jimmy; Guo, Haipeng

    2009-10-01

    Most analytical and numerical models developed to analyze pumping test data focus on saturated flow below the water table. Traditionally the soil above the initial water table prior to pumping has been thought to have little influence on the test results and has usually been ignored. It is hypothesized that, if the unsaturated zone is capped by low-permeability soil, airflow in the unsaturated zone may be developed during pumping and may have impact on the drawdown in the aquifer. A transient, three-dimensional and variably saturated flow model is employed to simulate the pumping-induced air and groundwater flows in both the saturated zone and unsaturated zone with a low-permeability layer. The results demonstrate that negative pressure in the unsaturated zone can be generated by pumping. The negative pressure begins to appear as the drawdown rate increases to a maximum, approaches a peak before the drawdown rate becomes zero, and then gradually disappears. Drawdown obtained from the capped aquifer is much greater because the water in the pores in the unsaturated zone is sucked by the negative pressure and the gravity drainage from the pores is hampered. Consequently, the drawdown versus time curve does not conform to the traditional S-shaped curve for an unconfined aquifer but is similar to that of a confined aquifer. If the airflow caused by the low-permeability cap is ignored, the error in estimated drawdown could be over 80% for the specific parameters and aquifer configuration used in the study. The possible errors in parameter estimation when airflow is ignored are explored. Overall, the hydraulic conductivity of the aquifer can be overestimated and the specific yield of the aquifer underestimated if airflow is ignored. The estimation error for specific yield tends to be greater than that in hydraulic conductivity.

  17. 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.

  18. 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.

  19. Mechanical Design of a Performance Test Rig for the Turbine Air-Flow Task (TAFT)

    NASA Technical Reports Server (NTRS)

    Xenofos, George; Forbes, John; Farrow, John; Williams, Robert; Tyler, Tom; Sargent, Scott; Moharos, Jozsef

    2003-01-01

    To support development of the Boeing-Rocketdyne RS84 rocket engine, a fill-flow, reaction turbine geometry was integrated into the NASA-MSFC turbine air-flow test facility. A mechanical design was generated which minimized the amount of new hardware while incorporating all test and instrUmentation requirements. This paper provides details of the mechanical design for this Turbine Air-Flow Task (TAFT) test rig. The mechanical design process utilized for this task included the following basic stages: Conceptual Design. Preliminary Design. Detailed Design. Baseline of Design (including Configuration Control and Drawing Revision). Fabrication. Assembly. During the design process, many lessons were learned that should benefit future test rig design projects. Of primary importance are well-defined requirements early in the design process, a thorough detailed design package, and effective communication with both the customer and the fabrication contractors. The test rig provided steady and unsteady pressure data necessary to validate the computational fluid dynamics (CFD) code. The rig also helped characterize the turbine blade loading conditions. Test and CFD analysis results are to be presented in another JANNAF paper.

  20. Recovery of airflow resistivity of poroelastic beams submitted to transient mechanical stress

    NASA Astrophysics Data System (ADS)

    Ogam, Erick

    2013-01-01

    The airflow resistivities of air-saturated poroelastic slender beams submitted to transient mechanical stress are recovered using fluid and solid borne compressional mode phase velocity expressions drawn from a modified Biot theory. A point where the two dilatational modes intersect and their phase velocities equal is first sought. This point also corresponds to the Biot transitional frequency indicating the frequency at which the solid and the pore fluid start disassociating due to the weakening of the viscous forces by the thinning of the viscous boundary layer in the pores. A bilinear time-frequency (TF) distribution is used to represent on the time-frequency plane, the captured transient mechanical stress waves from which the point of intersection/separation of the two modes is located. The projection of the Eigenfrequencies obtained from a simple 3D finite element modeling of the thin poroelastic beam, on a (TF) diagram, facilitates the identification of the modes. The transition frequencies for the poroelastic beams thus retrieved are verified through the use of variable frequency, single cycle sine wave bursts. The anisotropy of the foams are also revealed by analyzing the transient responses of the poroelastic beam specimens cut from the same panel but in two perpendicular directions in orientation to each other.

  1. Calibration for Thrust and Airflow Measurements in the CE-22 Advanced Nozzle Test Facility

    NASA Technical Reports Server (NTRS)

    Werner, Roger A.; Wolter, John D.

    2010-01-01

    CE-22 facility procedures and measurements for thrust and airflow calibration obtained with choked-flow ASME nozzles are presented. Six calibration nozzles are used at an inlet total pressure from 20 to 48 psia. Throat areas are from 9.9986 to 39.986 sq. in.. Throat Reynolds number varies from 1.8 to 7.9 million. Nozzle gross thrust coefficient (CFG) uncertainty is 0.25 to 0.75 percent, with smaller uncertainly generally for larger nozzles and higher inlet total pressure. Nozzle discharge coefficient (CDN) uncertainty is 0.15 percent or less for all the data. ASME nozzle calibrations need to be done before and after research model testing to achieve these uncertainties. In addition, facility capability in terms of nozzle pressure ratio (NPR) and nozzle airflow are determined. Nozzle pressure ratio of 50 or more is obtainable at 40 psia for throat areas between 20 and 30 sq. in.. Also presented are results for two of the ASME nozzles vectored at 10deg, a dead-weight check of the vertical (perpendicular to the jet axis) force measurement, a calibration of load cell forces for the effects of facility tank deflection with tank pressure, and the calibration of the metric-break labyrinth seal.

  2. 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.

  3. Characterization of Pump-Induced Acoustics in Space Launch System Main Propulsion System Liquid Hydrogen Feedline Using Airflow Test Data

    NASA Technical Reports Server (NTRS)

    Eberhart, C. J.; Snellgrove, L. M.; Zoladz, T. F.

    2015-01-01

    High intensity acoustic edgetones located upstream of the RS-25 Low Pressure Fuel Turbo Pump (LPFTP) were previously observed during Space Launch System (STS) airflow testing of a model Main Propulsion System (MPS) liquid hydrogen (LH2) feedline mated to a modified LPFTP. MPS hardware has been adapted to mitigate the problematic edgetones as part of the Space Launch System (SLS) program. A follow-on airflow test campaign has subjected the adapted hardware to tests mimicking STS-era airflow conditions, and this manuscript describes acoustic environment identification and characterization born from the latest test results. Fluid dynamics responsible for driving discrete excitations were well reproduced using legacy hardware. The modified design was found insensitive to high intensity edgetone-like discretes over the bandwidth of interest to SLS MPS unsteady environments. Rather, the natural acoustics of the test article were observed to respond in a narrowband-random/mixed discrete manner to broadband noise thought generated by the flow field. The intensity of these responses were several orders of magnitude reduced from those driven by edgetones.

  4. ENVIRONMENTAL TECHNOLOGY VERIFICATION, TEST REPORT OF CONTROL OF BIOAEROSOLS IN HVAC SYSTEMS, AIRFLOW PRODUCTS AFP30

    EPA Science Inventory

    The Environmental Technology Verification report discusses the technology and performance of the AFP30 air filter for dust and bioaerosol filtration manufactured by Airflow Products. The pressure drop across the filter was 62 Pa clean and 247 Pa dust loaded. The filtration effici...

  5. Airflow Resistance of Loose-Fill Mineral Fiber Insulations in Retrofit Applications

    SciTech Connect

    Schumacher, C. J.; Fox, M. J.; Lstiburek, J.

    2015-02-01

    This report expands on Building America Report 1109 by applying the experimental apparatus and test method to dense-pack retrofit applications using mineral fiber insulation materials. Three (3) fiber glass insulation materials and one (1) stone wool insulation material were tested, and the results compared to the cellulose results from the previous study.

  6. Airflow Resistance of Loose-Fill Mineral Fiber Insulations in Retrofit Applications

    SciTech Connect

    Schumacher, C. J.; Fox, M. J.; Lstiburek, J.

    2015-02-01

    This report expands on Building America Report 1109 by applying the experimental apparatus and test method to dense-pack retrofit applications using mineral fiber insulation materials. Three fiber glass insulation materials and one stone wool insulation material were tested, and the results compared to the cellulose results from the previous study.

  7. Airflow obstruction and exercise.

    PubMed

    Cooper, Christopher B

    2009-03-01

    The primary abnormality in chronic obstructive pulmonary disease (COPD) is chronic airway inflammation which results in airflow limitation. Disease progression is usually depicted as an accelerated decline in FEV(1) over time. However, COPD patients also manifest progressive static hyperinflation due to the combined effects of reduced lung elastic recoil and increased airway resistance. Superimposed on static hyperinflation are further increases in operational lung volumes (dynamic hyperinflation) brought on during exercise, exacerbations or tachypnea. An important consequence of exertional dyspnea is activity limitation. COPD patients have been shown to spend only a third of the day walking or standing compared with age-matched healthy individuals who spend more than half of their time in these activities. Furthermore, the degree of activity limitation measured by an accelerometer worsens with disease progression. COPD patients have been shown to have an accelerated loss of aerobic capacity (VO(2)max) and this correlates with mortality just as is seen with hypertension, diabetes and obesity. Thus physical inactivity is an important therapeutic target in COPD. Summarizing; airflow obstruction leads to progressive hyperinflation, activity limitation, physical deconditioning and other comorbidities that characterize the COPD phenotype. Targeting the airflow obstruction with long-acting bronchodilator therapy in conjunction with a supervised exercise prescription is currently the most effective therapeutic intervention in earlier COPD. Other important manifestations of skeletal muscle dysfunction include muscle atrophy and weakness. These specific problems are best addressed with resistance training with consideration of anabolic supplementation.

  8. Airflow sensing system

    NASA Technical Reports Server (NTRS)

    Gelbach, Herman R. (Inventor); Morgan, Michael D. (Inventor)

    1993-01-01

    Disclosed is an airflow sensing system for determining the type of airflow flowing over a flight surface. A hot film sensor is driven by a constant voltage feedback circuit that maintains the voltage across the sensor at a predetermined level. A signal processing circuit receives an output signal of the feedback circuit and determines whether the output signal is indicative of laminar, transitional or turbulent airflow. Transitional airflow is distinguished from turbulent airflow by a signal having significant energy in a low-frequency passband from 50-80 Hz. The signal processing circuit drives a three-color LED display to provide a visual indication of the type of airflow being sensed.

  9. The effect of inferior turbinate outfracture on nasal resistance to airflow in vasomotor rhinitis assessed by rhinomanometry.

    PubMed

    Thomas, P L; John, D G; Carlin, W V

    1988-02-01

    Twenty-eight patients with nasal obstruction due to vasomotor rhinitis were assessed using anterior rhinomanometry before and six weeks after the operation of out-fracture and amputation of the posterior ends of the inferior turbinates. It was found that the operation did not significantly improve the nasal airway. Though just over half the patients had an objective improvement in nasal airflow, only half of this group reported a subjective improvement in their symptoms.

  10. Torque requirement of rotating rods in airflow

    NASA Technical Reports Server (NTRS)

    Barna, P. S.; Crossman, G. R.

    1979-01-01

    Experiments were performed to determine the torque required for rotating a rotor disk fitted with a number of radially arranged rods placed into a ducted airflow. An array of stationary rods, also radially arranged, was placed upstream close to the rotor with a small gap between the rods to cause wake interference. The results show that torque generally increased with airflow and the rate of increase varied considerably. At lower values of airflow, the rate of increase was larger than at higher airflow, and definite torque peaks occurred at certain airflow rates, where the torque attained a maximum within the test airflow range. During the test, a maximum blade passage frequency of 2037 Hz was attained. The results also show that the torque peaks occurred at the same Strouhal number for all speeds.

  11. 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.

  12. Changes in nasal airflow and heat transfer correlate with symptom improvement after surgery for nasal obstruction.

    PubMed

    Kimbell, J S; Frank, D O; Laud, Purushottam; Garcia, G J M; Rhee, J S

    2013-10-18

    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.

  13. Geno- and phenotypic resistance tests.

    PubMed

    1998-09-01

    There are two types of experimental drug resistance tests, genotypic and phenotypic, that may be able to determine a person's level of resistance to certain HIV drugs. Genotypic resistance testing seeks mutations in the genetic structure of HIV. The analysis is typically conducted from a blood test, and several methods may be used to read the blood sample including a machine that reads gene sequences, a line probe assay, and the GeneChip, which scans blood samples into a computer. Phenotypic resistance testing assesses the quantity of a drug necessary to suppress the virus in a laboratory setting. Both tests require a patient to have a viral load over 1,000 HIV RNA copies, and both are relatively expensive. Neither test can predict which treatments will definitely be successful, as the results are likely to be subjective, depending on the laboratory. Pros and cons for each type of test are listed. Availability, cost, and contact information are provided.

  14. Airflow Model Testing to Determine the Distribution of Hot Gas Flow and O/F Ratio Across the Space Shuttle Main Engine Main Injector Assembly

    NASA Technical Reports Server (NTRS)

    Mahorter, L.; Chik, J.; McDaniels, D.; Dill, C.

    1990-01-01

    Engine 0209, the certification engine for the new Phase 2+ Hot Gas Manifold (HGM), showed severe deterioration of the Main Combustion Chamber (MCC) liner during hot fire tests. One theory on the cause of the damage held that uneven local distribution of the fuel rich hot gas flow through the main injector assembly was producing regions of high oxidizer/fuel (O/F) ratio near the wall of the MCC liner. Airflow testing was proposed to measure the local hot gas flow rates through individual injector elements. The airflow tests were conducted using full scale, geometrically correct models of both the current Phase 2 and the new Phase 2+ HGMs. Different main injector flow shield configurations were tested for each HGM to ascertain their effect on the pressure levels and distribution of hot gas flow. Instrumentation located on the primary faceplate of the main injector measured hot gas flow through selected injector elements. These data were combined with information from the current space shuttle main engine (SSME) power balances to produce maps of pressure, hot gas flow rate, and O/F ratio near the main injector primary plate. The O/F distributions were compared for the different injector and HGM configurations.

  15. Resistance-Welding Test Fixture

    NASA Technical Reports Server (NTRS)

    Brennan, Andrew D.

    1990-01-01

    Realistic welding conditions produce reliable specimens. Simple fixture holds resistance-welding test specimens. Specimen holder includes metallic holder and clamps to provide electrical and thermal paths and plastic parts providing thermal and electrical isolation.

  16. 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.

  17. 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.

  18. Workplace Breathing Rates: Defining Anticipated Values and Ranges for Respirator Certification Testing

    DTIC Science & Technology

    2004-09-01

    performance tests most affected by airflow rate are filter gas-life capacity, particulate filter efficiency, and respirator breathing resistances...efficacy when tested under standard laboratory protocols. The relevance and adequacy of airflow rates used in respirator certification testing has been... airflow conditions. NIOSH-approved non-powered APR chemical cartridges and canisters (filter systems) are tested at a constant flow rate of 64 liters

  19. Automatic insulation resistance testing apparatus

    DOEpatents

    Wyant, Francis J.; Nowlen, Steven P.; Luker, Spencer M.

    2005-06-14

    An apparatus and method for automatic measurement of insulation resistances of a multi-conductor cable. In one embodiment of the invention, the apparatus comprises a power supply source, an input measuring means, an output measuring means, a plurality of input relay controlled contacts, a plurality of output relay controlled contacts, a relay controller and a computer. In another embodiment of the invention the apparatus comprises a power supply source, an input measuring means, an output measuring means, an input switching unit, an output switching unit and a control unit/data logger. Embodiments of the apparatus of the invention may also incorporate cable fire testing means. The apparatus and methods of the present invention use either voltage or current for input and output measured variables.

  20. 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.

  1. Thermal performance characterization of residential wall systems using a calibrated hot box with airflow induced by differential pressures

    SciTech Connect

    Jones, D.C.; Ober, D.G.; Goodrow, J.T.

    1995-09-01

    ASTM E 283 ad ASTM E 1424 in conjunction with ASTM C 976 were used to study the effect of airflow on thermal performance of the wall. A typical residential 2 {times} 4 stud wall was constructed and placed on top of a subfloor, making a 2.44 {times} 2.74 m (8 by 9 ft) test specimen. This base wall assembly was then covered with two types of XPS sheathing, various housewraps, a 15{number_sign} felt, and a polyethylene vapor retarder film in 40 different configurations and tested individually per ASTM E 283 and per ASTM C 976. For 24 of the 40 C 976 tests, a differential pressure was induced across the test wall as per and ASTM E 1424. Airflows ranged from undetectable airflow at 0 {center_dot} Pa {Delta}P to 1.63 L/s {center_dot} m{sup 2} for the base wall assembly alone. Difference in airflow resistance performance between the ASTM E 283 and ASTM E 1424 test methods were noted. Thermal testing results incorporating both ASTM C 976 and ASTM E 1424 for tests 1--28 produced apparent thermal conductances (C-values) in the range of 0.40 W/m{sup 2} {center_dot} K for a nondetectable airflow level to 1.81 W/m{sup 2} {center_dot} K for an airflow of 1.53 L/s {center_dot} m{sup 2} for the base wall assembly alone with a 20-Pa {Delta}P. The calculated C-value for this base wall assembly was 0.40 W/m{sup 2} {center_dot} K. Test results reveal that airflow rates as low as 0.2 L/s {center_dot} m{sup 2} could produce a 46% increase in apparent C-value. Similar thermal performance differences were revealed when thicker shiplap XPS sheathing was used. Tests were also conducted using an Air-Tight Drywall configuration showing the effect of wind washing on thermal performance. By sealing the gypsum drywall on the base wall assembly tested, the apparent C-value, when exposed to a 12.5 Pa wind pressure, was found to be equivalent to a base wall assembly configuration which allows 0.15 L/s {center_dot} m{sup 2} airflow to penetrate completely through.

  2. Antimicrobial resistance in campylobacter: susceptibility testing methods and resistance trends.

    PubMed

    Ge, Beilei; Wang, Fei; Sjölund-Karlsson, Maria; McDermott, Patrick F

    2013-10-01

    Most Campylobacter infections are self-limiting but antimicrobial treatment (e.g., macrolides, fluoroquinolones) is necessary in severe or prolonged cases. Susceptibility testing continues to play a critical role in guiding therapy and epidemiological monitoring of resistance. The methods of choice for Campylobacter recommended by the Clinical and Laboratory Standards Institute (CLSI) are agar dilution and broth microdilution, while a disk diffusion method was recently standardized by the European Committee on Antimicrobial Susceptibility Testing (EUCAST). Macrolides, quinolones, and tetracyclines are among the common antimicrobials recommended for testing. Molecular determination of Campylobacter resistance via DNA sequencing or PCR-based methods has been performed. High levels of resistance to tetracycline and ciprofloxacin are frequently reported by many national surveillance programs, but resistance to erythromycin and gentamicin in Campylobacter jejuni remains low. Nonetheless, variations in susceptibility observed over time underscore the need for continued public health monitoring of Campylobacter resistance from humans, animals, and food.

  3. Using HIV resistance tests in clinical practice.

    PubMed

    Taylor, Stephen; Jayasuriya, Ashini; Smit, Erasmus

    2009-08-01

    Genotypic resistance testing is now a standard of care in HIV management. Although there are clear, published guidelines to recommend the appropriate use of these tests, clinicians and scientists still struggle to determine the optimal use of resistance tests given the finite budgets and time constraints under which they work. In this article we discuss some 'real-life' clinical situations and aim to provide a useful insight into when and where genotypic resistance testing can be optimally applied in the management of HIV-positive adults.

  4. News from the Test Resistance Trail.

    ERIC Educational Resources Information Center

    Ohanian, Susan

    2001-01-01

    An experienced teacher deplores the loony test questions used to make pass/fail decisions for Atlanta-area students. Test resistance is growing. Concerned teachers and parents nationwide are mailing copies of high-stakes tests to the media, lobbying legislators, spearheading protest organizations, and challenging politicians to take tests. (MLH)

  5. 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

  6. 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.

  7. Turbojet-exhaust-nozzle secondary-airflow pumping as an exit control of an inlet-stability bypass system for a Mach 2.5 axisymmetric mixed-compression inlet. [Lewis 10- by 10-ft. supersonic wind tunnel test

    NASA Technical Reports Server (NTRS)

    Sanders, B. W.

    1980-01-01

    The throat of a Mach 2.5 inlet that was attached to a turbojet engine was fitted with large, porous bleed areas to provide a stability bypass system that would allow a large, stable airflow range. Exhaust-nozzle, secondary-airflow pumping was used as the exit control for the stability bypass airflow. Propulsion system response and stability bypass performance were obtained for several transient airflow disturbances, both internal and external. Internal airflow disturbances included reductions in overboard bypass airflow, power lever angle, and primary-nozzle area, as well as compressor stall. Nozzle secondary pumping as a stability bypass exit control can provide the inlet with a large stability margin with no adverse effects on propulsion system performance.

  8. 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).

  9. Wind tunnel evaluation of YF-12 inlet response to internal airflow disturbances with and without control. [Lewis 10 by 10 ft supersonic wind tunnel tests

    NASA Technical Reports Server (NTRS)

    Cole, G. L.; Neiner, G. H.; Dustin, M. O.

    1978-01-01

    The response of terminal-shock position and static pressures in the subsonic duct of a YF-12 aircraft flight-hardware inlet to perturbations in simulated engine corrected airflow were obtained with and without inlet control. Frequency response data, obtained with inlet controls inactive, indicated the general nature of the inherent inlet dynamics, assisted in the design of controls, and provided a baseline reference for responses with active controls. All the control laws were implemented by means of a digital computer that could be programmed to behave like the flight inlet's existing analog control. The experimental controls were designed using an analytical optimization technique. The capabilities of the controls were limited primarily by the actuation hardware. The experimental controls provided somewhat better attenuation of terminal shock excursions than did the YF-13 inlet control. Controls using both the forward and aft bypass systems also provided somewhat better attenuation than those using just the forward bypass. The main advantage of using both bypasses is in the greater control flexibility that is achieved.

  10. Morphological variation and airflow dynamics in the human nose.

    PubMed

    Churchill, Steven E; Shackelford, Laura L; Georgi, J Nicole; Black, Michael T

    2004-01-01

    Airflow dynamics are recognized as being important to the functioning of the human nose in conditioning and filtering inspired air, yet these dynamics are poorly understood. Despite considerable research on airflow dynamics by otolaryngologists, respiratory physiologists, and toxicologists, major disagreements remain about the nature of airflow in the human nose. Specifically, there is little consensus about the character of nasal airflow regimes (laminar or turbulent) and about the major pathways of airflow through the internal chamber. Additionally, a number of features in the human nose have been argued to enhance airflow turbulence, thus increasing the exposure of moving air to the nasal mucosa and facilitating heat and moisture exchange in cold and/or dry climates. These features include: an inferior orientation of the nares; a nasal sill that is high relative to the floor of the internal nasal chamber; a nasal valve that is small in cross-sectional area relative to that of the internal chamber; and large, projecting conchae. The claim that these features affect airflow dynamics has never been tested. To clarify the nature of human nasal airflow and to test these claims of functional significance to nasal variation, we studied airflow across physiological flow rates using water and dye flowing through anatomically accurate acrylic models of human nasal air passageways (with adjustment of water flow rates to maintain dynamic similarity). The models were derived from direct casting of the nasal passageways of 10 Caucasian ("leptorrhine") cadavers (six male, four female). Measures of naris angle, nasal sill height, nasal valve area relative to internal chamber cross-sectional area, and relative projection of the inferior and middle turbinates were taken directly on the resulting casts. The relationships between aspects of nasal morphology and turbulent air flow were evaluated by examining the flow regimes (laminar, semiturbulent, or turbulent) at varying flow

  11. 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.

  12. 42 CFR 84.203 - Breathing resistance test; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Breathing resistance test; minimum requirements. 84... Chemical Cartridge Respirators § 84.203 Breathing resistance test; minimum requirements. (a) Resistance to... resistance requirements for chemical cartridge respirators are as follows: Maximum Resistance Type...

  13. 42 CFR 84.203 - Breathing resistance test; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Breathing resistance test; minimum requirements. 84... Chemical Cartridge Respirators § 84.203 Breathing resistance test; minimum requirements. (a) Resistance to... resistance requirements for chemical cartridge respirators are as follows: Maximum Resistance Type...

  14. Airflow patterns in complex workplaces

    SciTech Connect

    Mishima, J.; Selby, J.M.; Lynch, T.P.; Langer, G.; Vallario, E.J.

    1987-01-01

    There are many considerations in obtaining an accurate evaluation of aerosols. One aspect that has been neglected is the study of airflow patterns within the workplace. In many nuclear facilities, the operations performed required extensive equipment (e.g., glove boxes, piping) that create complex arrangements of physical barriers to flow. To provide samples of the airborne materials, particularly particles, knowledge of these complex airflow patterns is required for sampler placement. Recent studies have shown that materials introduced into the air flow within a workplace act as plumes embedded in major airflow streams. Portions of the plumes can recycle through the ventilated area, be lost to dead air pockets, or exhaust through unusual, unexpected outlets. Unusual flow patterns are observed even in relatively uncomplicated arrangements of equipment. This behavior must be factored into sampling/monitoring programs for evaluation of the airborne hazard to personnel within the workplace consistent with the objective of the program. Other factors that also must be considered to provide valid samples of airborne particulate materials are objectives of the sampling program, characteristics of the airborne particulate materials, nonsegregatory transport for the extracted materials, and requirements for the measurement techniques used.

  15. 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.

  16. 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.

  17. 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

  18. Coal Ash Corrosion Resistant Materials Testing

    SciTech Connect

    D. K. McDonald; P. L. Daniel; D. J. DeVault

    2003-08-31

    In April 1999, three identical superheater test sections were installed into the Niles Unit No.1 for the purpose of testing and ranking the coal ash corrosion resistance of candidate superheater alloys. The Niles boiler burns high sulfur coal (3% to 3.5%) that has a reasonably high alkali content, thus the constituents necessary for coal ash corrosion are present in the ash. The test sections were controlled to operate with an average surface metal temperature from approximately 1060 F to 1210 F which was well within the temperature range over which coal ash corrosion occurs. Thus, this combination of aggressive environment and high temperature was appropriate for testing the performance of candidate corrosion-resistant tube materials. Analyses of the deposit and scale confirmed that the aggressive alkali-iron-trisulfate constituent was present at the metal surface and active in tube metal wastage. The test sections were constructed so that the response of twelve different candidate tube and/or coating materials could be studied. The plan was to remove and evaluate one of the three test sections at time intervals of 1 year, 3 years, and 5 years. This would permit an assessment of performance of the candidate materials as a function of time. This report provides the results of the evaluation of Test Section C, including the samples that remained in the Test Section for the full exposure period as well as those that were removed early. The analysis of Test Section C followed much the same protocol that was employed in the assessment of Test Section A. Again, the focus was on determining and documenting the relative corrosion rates of the candidate materials. The detailed results of the investigation are included in this report as a series of twelve appendices. Each appendix is devoted to the performance of one of the candidate alloys. The table below summarizes metal loss rate for the worst case sample of each of the candidate materials for both Test Sections A and C

  19. 42 CFR 84.91 - Breathing resistance test; exhalation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Breathing resistance test; exhalation. 84.91...-Contained Breathing Apparatus § 84.91 Breathing resistance test; exhalation. (a) Resistance to exhalation...-circuit apparatus with a breathing machine as described in § 84.88, and the exhalation resistance...

  20. 42 CFR 84.91 - Breathing resistance test; exhalation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Breathing resistance test; exhalation. 84.91...-Contained Breathing Apparatus § 84.91 Breathing resistance test; exhalation. (a) Resistance to exhalation...-circuit apparatus with a breathing machine as described in § 84.88, and the exhalation resistance...

  1. 42 CFR 84.91 - Breathing resistance test; exhalation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Breathing resistance test; exhalation. 84.91...-Contained Breathing Apparatus § 84.91 Breathing resistance test; exhalation. (a) Resistance to exhalation...-circuit apparatus with a breathing machine as described in § 84.88, and the exhalation resistance...

  2. 42 CFR 84.90 - Breathing resistance test; inhalation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Breathing resistance test; inhalation. 84.90...-Contained Breathing Apparatus § 84.90 Breathing resistance test; inhalation. (a) Resistance to inhalation... machine as described in § 84.88. (b) The inhalation resistance of open-circuit apparatus shall not...

  3. 42 CFR 84.90 - Breathing resistance test; inhalation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Breathing resistance test; inhalation. 84.90...-Contained Breathing Apparatus § 84.90 Breathing resistance test; inhalation. (a) Resistance to inhalation... machine as described in § 84.88. (b) The inhalation resistance of open-circuit apparatus shall not...

  4. 42 CFR 84.91 - Breathing resistance test; exhalation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Breathing resistance test; exhalation. 84.91...-Contained Breathing Apparatus § 84.91 Breathing resistance test; exhalation. (a) Resistance to exhalation... continuous rate of 85 liters per minute. (b) The exhalation resistance of demand apparatus shall not...

  5. 42 CFR 84.91 - Breathing resistance test; exhalation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Breathing resistance test; exhalation. 84.91...-Contained Breathing Apparatus § 84.91 Breathing resistance test; exhalation. (a) Resistance to exhalation... continuous rate of 85 liters per minute. (b) The exhalation resistance of demand apparatus shall not...

  6. Mechanical responses of rat vibrissae to airflow

    PubMed Central

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

    2016-01-01

    ABSTRACT 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

  7. Nasal Airflow Measured by Rhinomanometry Correlates with FeNO in Children with Asthma

    PubMed Central

    Hsu, Jong-Hau; Liu, Yi-Ching; Wu, Jiunn-Ren; Dai, Zen-Kong

    2016-01-01

    Background Rhinitis and asthma share similar immunopathological features. Rhinomanometry is an important test used to assess nasal function and spirometry is an important tool used in asthmatic children. The degree to which the readouts of these tests are correlated has yet to be established. We sought to clarify the relationship between rhinomanometry measurements, fractional exhaled nitric oxide (FeNO), and spirometric measurements in asthmatic children. Methods Patients’ inclusion criteria: age between 5 and 18 years, history of asthma with nasal symptoms, and no anatomical deformities. All participants underwent rhinomanometric evaluations and pulmonary function and FeNO tests. Results Total 84 children were enrolled. By rhinomanometry, the degree of nasal obstruction was characterized as follows: (1) no obstruction in 33 children, (2) slight obstruction in 29 children, and (3) moderate obstruction in 22 children. FeNO was significantly lower in patients without obstruction than those with slight or moderate obstruction. Dividing patients according to ATS Clinical Practice Guidelines regarding FeNO, patients < 12 years with FeNO > 20 ppb had a lower total nasal airflow rate than those with FeNO < 20 ppb. Patients ≥ 12 years with FeNO > 25 ppb had a lower total nasal airflow rate than those with FeNO < 25 ppb. Conclusions Higher FeNO was associated with a lower nasal airflow and higher nasal resistance. This supports a relationship between upper and lower airway inflammation, as assessed by rhinomanometry and FeNO. The results suggest that rhinomanometry may be integrated as part of the functional assessment of asthma. PMID:27792747

  8. Reducing airflow energy use in multiple zone vav systems

    NASA Astrophysics Data System (ADS)

    Tukur, Ahmed Gidado

    estimated by shifting the damper distribution mean at each time to this maximum value and reducing the static pressure to achieve the same overall system airflow rate. The methodology was tested on three different buildings with varying system characteristics. Savings estimates correlated well to the savings actually realized from SPR. This result has significant implications for energy service providers, who could use the predictions to guarantee savings from SPR.

  9. 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.

  10. Experimental and modelling study of the effect of airflow orientation with respect to strip electrode on ozone production of surface dielectric barrier discharge

    NASA Astrophysics Data System (ADS)

    Mikeš, J.; Pekárek, S.; Soukup, I.

    2016-11-01

    This study examines the effect of airflow orientation with respect to the strip active electrode on concentration of ozone and nitrogen dioxide produced in a planar generator based on the surface dielectric barrier discharge. The orientation of the airflow was tested in parallel and perpendicular with respect to the strips. It was found that in the investigated range of average discharge power, the ozone concentration increases approximately by 25% when airflow was oriented in parallel with respect to the strips in comparison with perpendicular orientation of the airflow. Similarly the increase of nitrogen dioxide concentration was observed for parallel orientation of the airflow with respect to the strips in comparison with the perpendicular orientation of the airflow. Within the range of wavelengths from 250 to 1100 nm, the changes of intensities of spectral lines associated with airflow orientation have been observed. A 3D numerical model describing ion trajectories and airflow patterns have also been developed.

  11. 49 CFR Appendix D to Part 178 - Thermal Resistance Test

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Thermal Resistance Test D Appendix D to Part 178.... 178, App. D Appendix D to Part 178—Thermal Resistance Test 1. Scope. This test method evaluates the thermal resistance capabilities of a compressed oxygen generator and the outer packaging for a cylinder...

  12. Porous silver nanosheets: a novel sensing material for nanoscale and microscale airflow sensors.

    PubMed

    Marzbanrad, Ehsan; Zhao, Boxin; Zhou, Norman Y

    2015-11-06

    Fabrication of nanoscale and microscale machines and devices is one of the goals of nanotechnology. For this purpose, different materials, methods, and devices should be developed. Among them, various types of miniaturized sensors are required to build the nanoscale and microscale systems. In this research, we introduce a new nanoscale sensing material, silver nanosheets, for applications such as nanoscale and microscale gas flow sensors. The silver nanosheets were synthesized through the reduction of silver ions by ascorbic acid in the presence of poly(methacrylic acid) as a capping agent, followed by the growth of silver in the shape of hexagonal and triangular nanoplates, and self-assembly and nanojoining of these structural blocks. At the end of this process, the synthesized nanosheets were floated on the solution. Then, their electrical and thermal stability was demonstrated at 120 °C, and their atmospheric corrosion resistance was clarified at the same temperature range by thermogravimetric analysis. We employed the silver nanosheets in fabricating airflow sensors by scooping out the nanosheets by means of a sensor substrate, drying them at room temperature, and then annealing them at 300 °C for one hour. The fabricated sensors were tested for their ability to measure airflow in the range of 1 to 5 ml min(-1), which resulted in a linear response to the airflow with a response and recovery time around 2 s. Moreover, continuous dynamic testing demonstrated that the response of the sensors was stable and hence the sensors can be used for a long time without detectable drift in their response.

  13. Porous silver nanosheets: a novel sensing material for nanoscale and microscale airflow sensors

    NASA Astrophysics Data System (ADS)

    Marzbanrad, Ehsan; Zhao, Boxin; Zhou, Norman Y.

    2015-11-01

    Fabrication of nanoscale and microscale machines and devices is one of the goals of nanotechnology. For this purpose, different materials, methods, and devices should be developed. Among them, various types of miniaturized sensors are required to build the nanoscale and microscale systems. In this research, we introduce a new nanoscale sensing material, silver nanosheets, for applications such as nanoscale and microscale gas flow sensors. The silver nanosheets were synthesized through the reduction of silver ions by ascorbic acid in the presence of poly(methacrylic acid) as a capping agent, followed by the growth of silver in the shape of hexagonal and triangular nanoplates, and self-assembly and nanojoining of these structural blocks. At the end of this process, the synthesized nanosheets were floated on the solution. Then, their electrical and thermal stability was demonstrated at 120 °C, and their atmospheric corrosion resistance was clarified at the same temperature range by thermogravimetric analysis. We employed the silver nanosheets in fabricating airflow sensors by scooping out the nanosheets by means of a sensor substrate, drying them at room temperature, and then annealing them at 300 °C for one hour. The fabricated sensors were tested for their ability to measure airflow in the range of 1 to 5 ml min-1, which resulted in a linear response to the airflow with a response and recovery time around 2 s. Moreover, continuous dynamic testing demonstrated that the response of the sensors was stable and hence the sensors can be used for a long time without detectable drift in their response.

  14. Coal Ash Corrosion Resistant Materials Testing

    SciTech Connect

    D. K. McDonald; P. L. Daniel; D. J. DeVault

    2007-12-31

    In April 1999, three identical superheater test sections were installed into the Niles Unit No.1 for the purpose of testing and ranking the coal ash corrosion resistance of candidate superheater alloys. The Niles boiler burns high sulfur coal (3% to 3.5%) that has a moderate alkali content (0.2% sodium equivalents), thus the constituents necessary for coal ash corrosion are present in the ash. The test sections were controlled to operate with an average surface metal temperature from approximately 1060 F to 1210 F which was within the temperature range over which coal ash corrosion occurs. Thus, this combination of aggressive environment and high temperature was appropriate for testing the performance of candidate corrosion-resistant tube materials. Analyses of the deposit and scale confirmed that aggressive alkali sulfate constituents were present at the metal surface and active in tube metal wastage. The test sections were constructed so that the response of twelve different candidate tube and/or coating materials could be studied. The plan was to remove and evaluate one of the three test sections at time intervals of 1 year, 3 years, and 5 years. This would permit an assessment of performance of the candidate materials as a function of time. Test Section A was removed in November 2001 after about 24 months of service at the desired steam temperature set point, with about 15.5 months of exposure at full temperature. A progress report, issued in October 2002, was written to document the performance of the candidate alloys in that test section. The evaluation described the condition of each tube sample after exposure. It involved a determination of the rate of wall thickness loss for these samples. In cases where there was more than one sample of a candidate material in the test section, an assessment was made of the performance of the alloy as a function of temperature. Test Sections B and C were examined during the November 2001 outage, and it was decided that

  15. Visualization of airflow growing soap bubbles

    NASA Astrophysics Data System (ADS)

    Al Rahbi, Hamood; Bock, Matthew; Ryu, Sangjin

    2016-11-01

    Visualizing airflow inside growing soap bubbles can answer questions regarding the fluid dynamics of soap bubble blowing, which is a model system for flows with a gas-liquid-gas interface. Also, understanding the soap bubble blowing process is practical because it can contribute to controlling industrial processes similar to soap bubble blowing. In this study, we visualized airflow which grows soap bubbles using the smoke wire technique to understand how airflow blows soap bubbles. The soap bubble blower setup was built to mimic the human blowing process of soap bubbles, which consists of a blower, a nozzle and a bubble ring. The smoke wire was placed between the nozzle and the bubble ring, and smoke-visualized airflow was captured using a high speed camera. Our visualization shows how air jet flows into the growing soap bubble on the ring and how the airflow interacts with the soap film of growing bubble.

  16. Two-Dimensional Air-Flow Tests of the Effect of ITA Flowliner Slot Modification by Grinding/Polishing on Edge Tone Generation Potential

    NASA Technical Reports Server (NTRS)

    Sutliff, Daniel L. (Technical Monitor); Walker, Bruce E.

    2004-01-01

    Hersh Walker Acoustics (HWA) has performed a series of wind tunnel tests to support crack-repair studies for ITA flowliner vent slots. The overall goal of these tests is to determine if slot shape details have a significant influence on the propensity of the flowliner to produce aero-acoustic oscillations that could increase unsteady stresses on the flowliner walls. The test series, conducted using a full-scale two-dimensional model of a six-slot segment of the 38 slot liner, was intended to investigate the effects of altering slot shape by grinding away cracked portions.

  17. 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

  18. 42 CFR 84.203 - Breathing resistance test; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Breathing resistance test; minimum requirements. 84.203 Section 84.203 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Chemical Cartridge Respirators § 84.203 Breathing resistance test; minimum requirements. (a) Resistance...

  19. 42 CFR 84.203 - Breathing resistance test; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Breathing resistance test; minimum requirements. 84.203 Section 84.203 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Chemical Cartridge Respirators § 84.203 Breathing resistance test; minimum requirements. (a) Resistance...

  20. 42 CFR 84.203 - Breathing resistance test; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Breathing resistance test; minimum requirements. 84.203 Section 84.203 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Chemical Cartridge Respirators § 84.203 Breathing resistance test; minimum requirements. (a) Resistance...

  1. 30 CFR 7.48 - Acid resistance test.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Acid resistance test. 7.48 Section 7.48 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS TESTING BY APPLICANT OR THIRD PARTY Battery Assemblies § 7.48 Acid resistance test....

  2. 30 CFR 7.48 - Acid resistance test.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Acid resistance test. 7.48 Section 7.48 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS TESTING BY APPLICANT OR THIRD PARTY Battery Assemblies § 7.48 Acid resistance test....

  3. 30 CFR 7.48 - Acid resistance test.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Acid resistance test. 7.48 Section 7.48 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS TESTING BY APPLICANT OR THIRD PARTY Battery Assemblies § 7.48 Acid resistance test....

  4. Contact-resistance test probes: A concept

    NASA Technical Reports Server (NTRS)

    Brooks, C. H.; Maxwell, J. H.; Mc Dermott, R. J.

    1971-01-01

    Devices are used in inspection of contact resistance in plated connectors after assembly into cables. System permits rapid inspection of connectors when mating connectors or special apparatus are not available, and enables source of excessive resistance to be precisely determined.

  5. Relationship between pre-anesthetic and intra-anesthetic airway resistance in patients undergoing general anesthesia: A prospective observational study.

    PubMed

    Ikeda, Takamitsu; Uchida, Kanji; Yamauchi, Yasuhiro; Nagase, Takahide; Oba, Koji; Yamada, Yoshitsugu

    2017-01-01

    Surgery patients in Japan undergo routine spirometry testing prior to general anesthesia. The use of a flow sensor during general anesthesia has recently become common. However, it is not certain whether the information derived from flow-volume curves is being adequately used for mechanical ventilation management during general anesthesia. So far, there have been no attempts to calculate airway resistance using flow-volume curves. Therefore, we performed a prospective, observational study to investigate the relationship between pre-anesthetic and intra-anesthetic airway resistance in patients scheduled for surgery under general anesthesia. We calculated pre-anesthetic and intra-anesthetic airway resistance in each patient, based on the slopes of flow-volume curves obtained prior to and during general anesthesia. We also calculated endotracheal tube resistance to correct the intra-anesthetic airway resistance values calculated. A total of 526 patients were included in the study, and 98 patients had a forced expiratory volume in the first second/forced vital capacity ratio of < 70%. Pre-anesthetic airway resistance was significantly higher in patients with airflow obstruction than in those without airflow obstruction (p < 0.001), whereas no significant difference in intra-anesthetic airway resistance was found between patients with and without airflow obstruction during mechanical ventilation (p = 0.48). Pre-anesthetic and intra-anesthetic airway resistance values were closer to each other in patients without airflow obstruction, with a mean difference < 1.0 cmH2O L-1s-1, than in those with airflow obstruction, although these respiratory parameters were significantly different (p < 0.001). Intra-anesthetic airway resistance was not related to the FEV1/FVC ratio, regardless of the degree to which the FEV1/FVC ratio reflected pre-anesthetic airway resistance. As compared with patients with airflow obstruction, the mean difference between pre-anesthetic and intra

  6. Relationship between pre-anesthetic and intra-anesthetic airway resistance in patients undergoing general anesthesia: A prospective observational study

    PubMed Central

    Ikeda, Takamitsu; Uchida, Kanji; Yamauchi, Yasuhiro; Nagase, Takahide; Oba, Koji; Yamada, Yoshitsugu

    2017-01-01

    Surgery patients in Japan undergo routine spirometry testing prior to general anesthesia. The use of a flow sensor during general anesthesia has recently become common. However, it is not certain whether the information derived from flow-volume curves is being adequately used for mechanical ventilation management during general anesthesia. So far, there have been no attempts to calculate airway resistance using flow-volume curves. Therefore, we performed a prospective, observational study to investigate the relationship between pre-anesthetic and intra-anesthetic airway resistance in patients scheduled for surgery under general anesthesia. We calculated pre-anesthetic and intra-anesthetic airway resistance in each patient, based on the slopes of flow-volume curves obtained prior to and during general anesthesia. We also calculated endotracheal tube resistance to correct the intra-anesthetic airway resistance values calculated. A total of 526 patients were included in the study, and 98 patients had a forced expiratory volume in the first second/forced vital capacity ratio of < 70%. Pre-anesthetic airway resistance was significantly higher in patients with airflow obstruction than in those without airflow obstruction (p < 0.001), whereas no significant difference in intra-anesthetic airway resistance was found between patients with and without airflow obstruction during mechanical ventilation (p = 0.48). Pre-anesthetic and intra-anesthetic airway resistance values were closer to each other in patients without airflow obstruction, with a mean difference < 1.0 cmH2O L-1s-1, than in those with airflow obstruction, although these respiratory parameters were significantly different (p < 0.001). Intra-anesthetic airway resistance was not related to the FEV1/FVC ratio, regardless of the degree to which the FEV1/FVC ratio reflected pre-anesthetic airway resistance. As compared with patients with airflow obstruction, the mean difference between pre-anesthetic and intra

  7. 33 CFR 159.117 - Chemical resistance test.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Chemical resistance test. 159.117 Section 159.117 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION MARINE SANITATION DEVICES Design, Construction, and Testing § 159.117 Chemical resistance test....

  8. 49 CFR Appendix D to Part 178 - Thermal Resistance Test

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Thermal Resistance Test D Appendix D to Part 178 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY... to Part 178—Thermal Resistance Test 1. Scope. This test method evaluates the thermal...

  9. 33 CFR 159.117 - Chemical resistance test.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Chemical resistance test. 159.117 Section 159.117 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION MARINE SANITATION DEVICES Design, Construction, and Testing § 159.117 Chemical resistance test....

  10. 49 CFR Appendix D to Part 178 - Thermal Resistance Test

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Thermal Resistance Test D Appendix D to Part 178 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY... to Part 178—Thermal Resistance Test 1. Scope. This test method evaluates the thermal...

  11. 33 CFR 159.117 - Chemical resistance test.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Chemical resistance test. 159.117 Section 159.117 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION MARINE SANITATION DEVICES Design, Construction, and Testing § 159.117 Chemical resistance test....

  12. 33 CFR 159.117 - Chemical resistance test.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Chemical resistance test. 159.117 Section 159.117 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION MARINE SANITATION DEVICES Design, Construction, and Testing § 159.117 Chemical resistance test....

  13. 49 CFR Appendix D to Part 178 - Thermal Resistance Test

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Thermal Resistance Test D Appendix D to Part 178 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY... to Part 178—Thermal Resistance Test 1. Scope. This test method evaluates the thermal...

  14. 49 CFR Appendix D to Part 178 - Thermal Resistance Test

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Thermal Resistance Test D Appendix D to Part 178 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY... to Part 178—Thermal Resistance Test 1. Scope. This test method evaluates the thermal...

  15. 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

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. Laboratory test method for dirt pickup resistance and stain removal

    NASA Astrophysics Data System (ADS)

    Ren, Shiwei; Zheng, Xueying; Liu, Yi; Jiang, Quan

    2017-03-01

    The pollution characteristics of current atmospheric particulates was summarized in the present investigation. The composition and proportion of the pollution sources used for dirt pickup resistance and stain removal test were adjusted, and the pollution sources used for new type dirt pickup resistance and stain removal test produced. In addition, a new dirt pickup method was adopted, and a set of new type laboratory dirt pickup resistance and stain removal tests developed by taking comprehensive consideration of the existing state and dirt pickup mode of actual atmospheric particulates. It verifies the rationality, feasibility and effectiveness of new test methods for dirt pickup resistance and stain removal based on the contrast test over the new and old test methods.

  1. Lung sound intensity in patients with emphysema and in normal subjects at standardised airflows.

    PubMed Central

    Schreur, H J; Sterk, P J; Vanderschoot, J; van Klink, H C; van Vollenhoven, E; Dijkman, J H

    1992-01-01

    BACKGROUND: A common auscultatory finding in pulmonary emphysema is a reduction of lung sounds. This might be due to a reduction in the generation of sounds due to the accompanying airflow limitation or to poor transmission of sounds due to destruction of parenchyma. Lung sound intensity was investigated in normal and emphysematous subjects in relation to airflow. METHODS: Eight normal men (45-63 years, FEV1 79-126% predicted) and nine men with severe emphysema (50-70 years, FEV1 14-63% predicted) participated in the study. Emphysema was diagnosed according to pulmonary history, results of lung function tests, and radiographic criteria. All subjects underwent phonopneumography during standardised breathing manoeuvres between 0.5 and 2 1 below total lung capacity with inspiratory and expiratory target airflows of 2 and 1 l/s respectively during 50 seconds. The synchronous measurements included airflow at the mouth and lung volume changes, and lung sounds at four locations on the right chest wall. For each microphone airflow dependent power spectra were computed by using fast Fourier transformation. Lung sound intensity was expressed as log power (in dB) at 200 Hz at inspiratory flow rates of 1 and 2 l/s and at an expiratory flow rate of 1 l/s. RESULTS: Lung sound intensity was well repeatable on two separate days, the intraclass correlation coefficient ranging from 0.77 to 0.94 between the four microphones. The intensity was strongly influenced by microphone location and airflow. There was, however, no significant difference in lung sound intensity at any flow rate between the normal and the emphysema group. CONCLUSION: Airflow standardised lung sound intensity does not differ between normal and emphysematous subjects. This suggests that the auscultatory finding of diminished breath sounds during the regular physical examination in patients with emphysema is due predominantly to airflow limitation. Images PMID:1440459

  2. 30 CFR 7.48 - Acid resistance test.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Acid resistance test. 7.48 Section 7.48 Mineral... MINING PRODUCTS TESTING BY APPLICANT OR THIRD PARTY Battery Assemblies § 7.48 Acid resistance test. (a... solution of sulfuric acid (H2 SO4) by mixing 853 ml of water with 199 ml of sulfuric acid (H2 SO4) with...

  3. Airflow mechanics in models of equine obstructive airway disease under conditions simulating exercise.

    PubMed

    Bayly, W M; Slocombe, R F

    1997-01-01

    Effects of respiratory tract obstructions on ventilatory mechanics in horses exercising at high speeds were tested with a fibreglass replica of the airways (nares to mainstem bronchi) of an adult horse. Segmental pressures were recorded at six sites along the model at four different unidirectional flows (1300-4100 litre min-1), and the respective resistances (R) to airflow were calculated. The external nares and the larynx made the greatest contributions to the total resistance (RTOT) when no obstruction was present. Modifying the model to simulate severe pharyngeal lymphoid hyperplasia (PLH) had no effect on R at the larynx or at any point in the trachea under these flow conditions. Two 16 litre anaesthetic rebreathing bags were attached to the bronchial end of the model, and tidal ventilation generated by a piston pump. Upper (nares to pharynx) and lower tract R (RU and RL) and RTOT, and dynamic compliance were determined for pump volumes (Vp) of six and 12 litres, at pumping frequencies (fp) of 20-100 min-1 while the airway was clear, and after modifying it to simulate either PLH or partial bronchial obstruction. Model condition had no effect on RU. However, RL and RTOT were higher in the PLH simulated condition when fp > or = 90 and Vp = 12 litres (P < 0.05). This suggested that severe PLH may significantly interfere with airflow distal to the site of the lesions during high frequency high volume ventilation of the type seen in galloping horses. With partial bronchial obstruction RL and RTOT were increased when fp > 34 with each Vp. The applicability of the model was verified by comparing results from the unobstructed state with those from normal horses exercising on a treadmill.

  4. Virologic Tools for HCV Drug Resistance Testing

    PubMed Central

    Fourati, Slim; Pawlotsky, Jean-Michel

    2015-01-01

    Recent advances in molecular biology have led to the development of new antiviral drugs that target specific steps of the Hepatitis C Virus (HCV) lifecycle. These drugs, collectively termed direct-acting antivirals (DAAs), include non-structural (NS) HCV protein inhibitors, NS3/4A protease inhibitors, NS5B RNA-dependent RNA polymerase inhibitors (nucleotide analogues and non-nucleoside inhibitors), and NS5A inhibitors. Due to the high genetic variability of HCV, the outcome of DAA-based therapies may be altered by the selection of amino-acid substitutions located within the targeted proteins, which affect viral susceptibility to the administered compounds. At the drug developmental stage, preclinical and clinical characterization of HCV resistance to new drugs in development is mandatory. In the clinical setting, accurate diagnostic tools have become available to monitor drug resistance in patients who receive treatment with DAAs. In this review, we describe tools available to investigate drug resistance in preclinical studies, clinical trials and clinical practice. PMID:26690198

  5. Dry and wet arc track propagation resistance testing

    NASA Technical Reports Server (NTRS)

    Beach, Rex

    1995-01-01

    The wet arc-propagation resistance test for wire insulation provides an assessment of the ability of an insulation to prevent damage in an electrical environment. Results of an arc-propagation test may vary slightly due to the method of arc initiation; therefore a standard test method must be selected to evaluate the general arc-propagation resistance characteristics of an insulation. This test method initiates an arc by dripping salt water over pre-damaged wires which creates a conductive path between the wires. The power supply, test current, circuit resistances, and other variables are optimized for testing 20 guage wires. The use of other wire sizes may require modifications to the test variables. The dry arc-propagation resistance test for wire insulation also provides an assessment of the ability of an insulation to prevent damage in an electrical arc environment. In service, electrical arcs may originate form a variety of factors including insulation deterioration, faulty installation, and chafing. Here too, a standard test method must be selected to evaluate the general arc-propagation resistance characteristics of an insulation. This test method initiates an arc with a vibrating blade. The test also evaluates the ability of the insulation to prevent further arc-propagation when the electrical arc is re-energized.

  6. The E-beam resist test facility: performance testing and benchmarking of E-beam resists for advanced mask writers

    NASA Astrophysics Data System (ADS)

    Malloy, Matt; Jang, Il Yong; Mellish, Mac; Litt, Lloyd C.; Raghunathan, Ananthan; Hartley, John

    2012-11-01

    With each new generation of e-beam mask writers comes the ability to write leading edge photomasks with improved patterning performance and increased throughput. However, these cutting-edge e-beam tools are often used with older generation resists, preventing the end-user from taking full advantage of the tool's potential. The generation gap between tool and resist will become even more apparent with the commercialization of multi-beam mask writers, which are expected to be available for pilot line use around 2015. The mask industry needs resists capable of meeting the resolution, roughness, and sensitivity requirements of these advanced tools and applications. The E-beam Resist Test Facility (ERTF) has been established to fill the need for consortium-based testing of e-beam resists for mask writing applications on advanced mask writers out to the 11nm half-pitch node and beyond. SEMATECH and the College of Nanoscale Science and Engineering (CNSE) began establishing the ERTF in early 2012 to test e-beam resist samples from commercial suppliers and university labs against the required performance metrics for each application at the target node. Operations officially began on June 12, 2012, at which time the first e-beam resist samples were tested. The ERTF uses the process and metrology infrastructure available at CNSE, including a Vistec VB300 Vectorscan e-beam tool adjusted to operate at 50kv. Initial testing results show that multiple resists already meet, or are close to meeting, the resolution requirements for mask writing at the 11nm node, but other metrics such as line width roughness still need improvement. An overview of the ERTF and its capabilities is provided here. Tools, baseline processes, and operation strategy details are discussed, and resist testing and benchmarking results are shown. The long-term outlook for the ERTF and plans to expand capability and testing capacity, including resist testing for e-beam direct write lithography, are also

  7. Resistance to High-Stakes Testing Spreads

    ERIC Educational Resources Information Center

    Schaeffer, Bob

    2012-01-01

    A rising tide of protest is sweeping across the nation as growing numbers of parents, teachers, administrators and academics take action against high-stakes testing. Instead of test-and-punish policies, which have failed to improve academic performance or equity, the movement is pressing for broader forms of assessment. From Texas to New York and…

  8. 30 CFR 7.48 - Acid resistance test.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... MINING PRODUCTS TESTING BY APPLICANT OR THIRD PARTY Battery Assemblies § 7.48 Acid resistance test. (a) Test procedures. (1) Prepare one sample each of the insulated surfaces of the battery box and of the... insulation plus the battery cover or box material. The insulation thickness shall be representative of...

  9. The effects of inferior turbinoplasty on nasal airflow during cosmetic rhinoplasty.

    PubMed

    Zojaji, R; Keshavarzmanesh, M; Bakhshaee, M; Behdani, R; Esmaeelzadeh, S; MazloumFarsiBaf, M

    2016-04-01

    Rhinoplasty is one of the most common and challenging cosmetic procedures. One of the complications of rhinoplasty associated with dissatisfaction is nasal obstruction, which is often due to narrowing of the nasal valve area. Application of certain procedures such as turbinoplasty can prevent and correct this problem. This study aim was to investigate the effect of inferior turbinoplasty in reduction of airflow resistance and nasal obstruction. Using active anterior rhinomanometry, nasal airflow was measured in 50 patients who underwent cosmetic rhinoplasty and bilateral turbinoplasty before and 6 months after surgery. None of the patients subjectively complained of nasal obstruction before or after surgery. According to rhinomanometry results, improvement in nasal airflow was seen both in inspiration and expiration, although only expiration was significant (p = 0.034). Airflow changes in males and females and in different age groups was not significant (p > 0.05). It appears that rhinoplasty does not adversely affect nasal airflow when it is accompanied by simple adjuvant procedure inferior turbinoplasty.

  10. Full-scale aircraft cabin flammability tests of improved fire-resistant materials, test series 2

    NASA Technical Reports Server (NTRS)

    Stuckey, R. N.; Bricker, R. W.; Kuminecz, J. F.; Supkis, D. E.

    1976-01-01

    Full-scale aircraft flammability tests in which the effectiveness of new fire-resistant materials was evaluated by comparing their burning characteristics with those of other fire-resistant aircraft materials were described. New-fire-resistant materials that are more economical and better suited for aircraft use than the previously tested fire-resistant materials were tested. The fuel ignition source for one test was JP-4; a smokeless fuel was used for the other test. Test objectives, methods, materials, and results are presented and discussed. The results indicate that, similar to the fire-resistant materials tested previously, the new materials decompose rather than ignite and do not support fire propagation. Furthermore, the new materials did not produce a flash fire.

  11. 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.

  12. 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.

  13. Echinocandin Resistance, Susceptibility Testing and Prophylaxis: Implications for Patient Management

    PubMed Central

    Perlin, David S.

    2014-01-01

    This article addresses the emergence of echinocandin resistance among Candida species, mechanisms of resistance, factors that promote resistance and confounding issues surrounding standard susceptibility testing. Fungal infections remain a significant cause of global morbidity and mortality, especially among patients with underlying immunosupression. Antifungal therapy is a critical component of patient management for acute and chronic diseases. Yet, therapeutic choices are limited due to only a few drug classes available to treat systemic disease. Moreover, the problem is exacerbated by the emergence of antifungal resistance, which has resulted in difficult to manage multidrug resistant strains. Echinocandin drugs are now the preferred choice to treat a range of candidiasis. These drugs target and inhibit the fungal-specific enzyme glucan synthase, which is responsible for the biosynthesis of a key cell wall polymer. Therapeutic failures involving acquisition of resistance among susceptible organisms like Candida albicans is largely a rare event. However, in recent years, there is an alarming trend of increased resistance among strains of Candida glabrata, which in many cases are also resistant to azole drugs. Echinocandin resistance is always acquired during therapy and the mechanism of resistance is well established to involve amino acid changes in “hot-spot regions of the Fks subunits carrying the catalytic portion of glucan synthase. These changes significantly decrease the sensitivity of the enzyme to drug resulting in higher MIC values. A range of drug responses, from complete to partial refractory response, is observed depending on the nature of the amino acid substitution, and clinical responses are recapitulated in pharmacodynamic models of infection. The cellular processes promoting the formation of resistant Fks strains involve complex stress response pathways, which yield a variety of adaptive compensatory genetic responses. Stress-adapted cells

  14. Theory and Test of Stress Resistance

    DTIC Science & Technology

    1992-04-01

    Stroop Test for measuring shape and food concerns in eating disorders: A quantitative measure of psychopathology. International Journal of Eating Disorders , 8... Journal of Eating Disorders , 9., 447-452. 29. McKenna F.P. & Sharma D. (in preperation) Uncontrolled emotional processing: An examination of the...681-687. 28. Channon S. & Hayward A. (1990). The effect of short-term fasting on processing of food cues in normal subjects. International

  15. Test for bacterial resistance build-up against plasma treatment

    NASA Astrophysics Data System (ADS)

    Zimmermann, J. L.; Shimizu, T.; Schmidt, H.-U.; Li, Y.-F.; Morfill, G. E.; Isbary, G.

    2012-07-01

    It is well known that the evolution of resistance of microorganisms to a range of different antibiotics presents a major problem in the control of infectious diseases. Accordingly, new bactericidal ‘agents’ are in great demand. Using a cold atmospheric pressure (CAP) plasma dispenser operated with ambient air, a more than five orders of magnitude inactivation or reduction of Methicillin-resistant Staphylococcus aureus (MRSA; resistant against a large number of the tested antibiotics) was obtained in less than 10 s. This makes CAP the most promising candidate for combating nosocomial (hospital-induced) infections. To test for the occurrence and development of bacterial resistance against such plasmas, experiments with Gram-negative bacteria (Escherichia coli) and Gram-positive bacteria (Enterococcus mundtii) were performed. The aim was to determine quantitative limits for primary (naturally) or secondary (acquired) resistance against the plasma treatment. Our results show that E. coli and E. mundtii possess no primary resistance against the plasma treatment. By generating four generations of bacteria for every strain, where the survivors of the plasma treatment were used for the production of the next generation, a lower limit to secondary resistance was obtained. Our results indicate that CAP technology could contribute to the control of infections in hospitals, in outpatient care and in disaster situations, providing a new, fast and efficient broad-band disinfection technology that is not constrained by bacterial resistance mechanisms.

  16. A Computational Study of the Respiratory Airflow Characteristics in Normal and Obstructed Human Airways

    DTIC Science & Technology

    2014-01-01

    normal and three different obstructed airway geometries, consisting of symmetric, asym- metric, and random obstructions. Fig. 2 shows the geometric ...normal and obstructed airways Airway resistance is a measure of the opposition to the airflow caused by geometric properties, such as airway obstruction...pressure drops. Resistance values were dependent on the degree and geometric distribution of the obstruction sites. In the symmetric obstruction model

  17. State Waste Discharge Permit Application: Electric resistance tomography testing

    SciTech Connect

    Not Available

    1994-04-01

    This permit application documentation is for a State Waste Discharge Permit issued in accordance with requirements of Washington Administrative Code 173-216. The activity being permitted is a technology test using electrical resistance tomography. The electrical resistance tomography technology was developed at Lawrence Livermore National Laboratory and has been used at other waste sites to track underground contamination plumes. The electrical resistance tomography technology measures soil electrical resistance between two electrodes. If a fluid contaminated with electrolytes is introduced into the soil, the soil resistance is expected to drop. By using an array of measurement electrodes in several boreholes, the areal extent of contamination can be estimated. At the Hanford Site, the purpose of the testing is to determine if the electrical resistance tomography technology can be used in the vicinity of large underground metal tanks without the metal tank interfering with the test. It is anticipated that the electrical resistance tomography technology will provide a method for accurately detecting leaks from the bottom of underground tanks, such as the Hanford Site single-shell tanks.

  18. 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 %.

  19. Evaluation of commercially available techniques and development of simplified methods for measuring grille airflows in HVAC systems

    SciTech Connect

    Walker, Iain S.; Wray, Craig P.; Guillot, Cyril; Masson, S.

    2003-08-01

    In this report, we discuss the accuracy of flow hoods for residential applications, based on laboratory tests and field studies. The results indicate that commercially available hoods are often inadequate to measure flows in residential systems, and that there can be a wide range of performance between different flow hoods. The errors are due to poor calibrations, sensitivity of existing hoods to grille flow non-uniformities, and flow changes from added flow resistance. We also evaluated several simple techniques for measuring register airflows that could be adopted by the HVAC industry and homeowners as simple diagnostics that are often as accurate as commercially available devices. Our test results also show that current calibration procedures for flow hoods do not account for field application problems. As a result, organizations such as ASHRAE or ASTM need to develop a new standard for flow hood calibration, along with a new measurement standard to address field use of flow hoods.

  20. POISON RESISTANT CATALYST DEVELOPMENT AND TESTING

    SciTech Connect

    Andrew W. Wang

    2001-03-29

    The Alternative Fuels Field Test Unit (AFFTU) is a portable laboratory designed specifically to provide on-site evaluation of potential feedstocks for processes that produce alternative fuels from indigenous raw materials such as coal, natural gas or environmentally disadvantaged carbonaceous feedstocks. Since conversion of these raw materials into feed gas streams can produce a variety of bulk gas compositions, which furthermore can contain a myriad of trace components, it is necessary to evaluate each new feedstock on an individual basis. While it is possible to prepare blended gas mixtures to simulate the bulk composition of a known feedstock, it is neither possible nor cost-effective to simulate adequately the variety of trace chemicals present in that feedstock--some of which may not even be detected by routine analysis. Additionally, the transient composition of the gas during upsets or routine process changes may have an impact on the proposed process that is not foreseen in standard design. To address these concerns, the AFFTU was constructed with the following experimental capabilities: (1) A state-of-the-art gas chromatograph system to perform semi-continuous monitoring of both bulk composition and the concentration of key trace poisons down to one part per billion (ppb). (2) A 30-mL reactor system that can accept up to two feed streams from the customer, allowing a true life test with the actual gas projected for use in the proposed facility. (3) A manifold of four adsorbent beds, located upstream of the reactor, which permits the testing of adsorbents for the removal of contaminants from the feed stream. The effectiveness of these adsorbents may be evaluated either by analysis of the gas upstream and downstream of the bed (or at an intermediate point within the bed) or by observing the impact of the presence or absence of that bed on the actual stability of the catalyst activity. To achieve portability, the AFFTU was constructed in a commercial 48-foot

  1. Model flight tests of a spin-resistant trainer configuration

    NASA Technical Reports Server (NTRS)

    Yip, Long P.; Ross, Holly M.; Robelen, David B.

    1992-01-01

    Powered, radio-controlled flight tests were conducted on a 1/4-scale model of a spin-resistant trainer configuration to determine the stall departure and spin resistance characteristics provided by an outboard wing leading-edge droop modification. The model was instrumented to provide quantitative as well as qualitative information on flight characteristics. Flight test results indicated that the unmodified configuration (wing leading-edge droop off) exhibited an abrupt, uncontrollable roll departure at the stall. With the outboard wing leading-edge droop installed, the modified configuration exhibited flight characteristics that were resistant to stall departure and spin entry. The stall departure and spin resistance characteristics of the modified configuration were demonstrated in flight maneuvers that included idle-power stalls, full-power stalls, sideslip stalls, and accelerated stalls.

  2. 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

  3. Computational fluid dynamics simulations of respiratory airflow in human nasal cavity and its characteristic dimension study

    NASA Astrophysics Data System (ADS)

    Zhang, Jun; Liu, Yingxi; Sun, Xiuzhen; Yu, Shen; Yu, Chi

    2008-04-01

    To study the airflow distribution in human nasal cavity during respiration and the characteristic parameters of nasal structure, three-dimensional, anatomically accurate representations of 30 adult nasal cavity models were reconstructed based on processed tomography images collected from normal people. The airflow fields in nasal cavities were simulated by fluid dynamics with finite element software ANSYS. The results showed that the difference of human nasal cavity structure led to different airflow distribution in the nasal cavities and variation of the main airstream passing through the common nasal meatus. The nasal resistance in the regions of nasal valve and nasal vestibule accounted for more than half of the overall resistance. The characteristic model of nasal cavity was extracted on the basis of characteristic points and dimensions deduced from the original models. It showed that either the geometric structure or the airflow field of the two kinds of models was similar. The characteristic dimensions were the characteristic parameters of nasal cavity that could properly represent the original model in model studies on nasal cavity.

  4. 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

  5. Electrical resistance tests of glass mat type separators

    SciTech Connect

    Lind, A.L.

    1997-12-01

    Resistance measurement of glass mat separators for VRLA batteries is necessary for proper design selection. The equipment described makes sample comparison possible under compression in either flooded or starved condition. The Palico Instrument Labs method operates on the principle of measuring the change in resistance of test cell as electrolyte level is changed, first with and then without the separator sample. Since the separator can only be removed by removing the Model 903 Carrier and then reinserting after separator removal, stability to test readings and accurate measurement of electrolyte level are essential. Measurements are made with a reversing polarity DC current in all of the Palico resistance test equipment which closely match conditions found in the final battery.

  6. In vitro detection of benzimidazole resistance in Haemonchus contortus: egg hatch test versus larval development test.

    PubMed

    Várady, M; Cudeková, P; Corba, J

    2007-10-21

    The present study was designed to compare the egg hatch test (EHT) and the larval development test (LDT) as in vitro tools for detection of benzimidazole (BZ) resistance in Haemonchus contortus, a nematode parasite of small ruminants. Comparisons were made during a course of infection and changes in both EHT and LDT were monitored to measure the correlation between resistance and susceptibility in different parasite stages (eggs and larvae). In addition, mixed doses of known numbers of susceptible and BZ-resistant H. contortus eggs were used to assess the sensitivity of LDT for the detection of low levels of resistance. The degree of resistance for each test was expressed as resistance factor (RF). The LDT showed a greater ability to distinguish between four susceptible and four resistant isolates of H. contortus with higher resistance factors compared to the EHT. For the EHT the RF by using ED(50) criterion ranged from 3.2 to 13.3 and from 7.4 to 25.2 by using LC(99). For LDT the resistant isolates were 4.3-63.1 times more tolerant than the susceptible isolates using the ED(50) criterion and 91.1-1411.0 times more tolerant using the LC(99) criterion. The LDT was also able to clearly indicate the presence of low level (4%) of resistant larvae amongst a susceptible background population.

  7. 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

  8. Coolant pressure and airflow distribution in a strut-supported transpiration-cooled vane for a gas turbine engine

    NASA Technical Reports Server (NTRS)

    Kaufman, A.; Poferl, D. J.; Richards, H. T.

    1972-01-01

    An analysis to predict pressure and flow distribution in a strut-supported wire-cloth vane was developed. Results were compared with experimental data obtained from room-temperature airflow tests conducted over a range of vane inlet airflow rates from 10.7 to 40.4 g/sec (0.0235 to 0.0890 lb/sec). The analytical method yielded reasonably accurate predictions of vane coolant flow rate and pressure distribution.

  9. Development and testing of advanced fire-resistant photovoltaic modules

    NASA Astrophysics Data System (ADS)

    Sugimura, R. S.; Otth, D. H.; Ross, R. G., Jr.

    The evaluation of back-surface materials flammability in order to identify fire resistant module designs is examined. The fire test apparatus, burning-brand test sequence, and spread-of-flame test sequence are described. Video recordings and time-temperature profiles of module back surfaces are utilized to study the flammability failure mechanism and identify high-temperature materials. A table of flammability test results for various module designs is provided. The data reveals that 2-mil kapton, fiberglass cloth coated or impregnated with a material to plug pores, and metal foil back-surface materials achieve class A and B fire-resistance levels, and are applicable for photovoltaic module designs.

  10. Protocols for Robust Herbicide Resistance Testing in Different Weed Species.

    PubMed

    Panozzo, Silvia; Scarabel, Laura; Collavo, Alberto; Sattin, Maurizio

    2015-07-02

    Robust protocols to test putative herbicide resistant weed populations at whole plant level are essential to confirm the resistance status. The presented protocols, based on whole-plant bioassays performed in a greenhouse, can be readily adapted to a wide range of weed species and herbicides through appropriate variants. Seed samples from plants that survived a field herbicide treatment are collected and stored dry at low temperature until used. Germination methods differ according to weed species and seed dormancy type. Seedlings at similar growth stage are transplanted and maintained in the greenhouse under appropriate conditions until plants have reached the right growth stage for herbicide treatment. Accuracy is required to prepare the herbicide solution to avoid unverifiable mistakes. Other critical steps such as the application volume and spray speed are also evaluated. The advantages of this protocol, compared to others based on whole plant bioassays using one herbicide dose, are related to the higher reliability and the possibility of inferring the resistance level. Quicker and less expensive in vivo or in vitro diagnostic screening tests have been proposed (Petri dish bioassays, spectrophotometric tests), but they provide only qualitative information and their widespread use is hindered by the laborious set-up that some species may require. For routine resistance testing, the proposed whole plant bioassay can be applied at only one herbicide dose, so reducing the costs.

  11. Thermal-Interaction Matrix For Resistive Test Structure

    NASA Technical Reports Server (NTRS)

    Buehler, Martin G.; Dhiman, Jaipal K.; Zamani, Nasser

    1990-01-01

    Linear mathematical model predicts increase in temperature in each segment of 15-segment resistive structure used to test electromigration. Assumption of linearity based on fact: equations that govern flow of heat are linear and coefficients in equations (heat conductivities and capacities) depend only weakly on temperature and considered constant over limited range of temperature.

  12. Test and Evaluation of Four Fire Resistant Booms at OHMSETT

    DTIC Science & Technology

    1999-08-01

    steel Proprietary Stainless steel Resistant Material information (SS) woven blend of Inconel® and Fiberfrax ® Tension Member 3/8" Galvanized Stainless...material ( Fiberfrax ) which was severely damaged during the bum tests. In terms of percentages, and relative to baseline loss speeds, The first wave

  13. Rolling resistance of electric vehicle tires from track tests

    NASA Technical Reports Server (NTRS)

    Dustin, M. O.; Slavik, R. J.

    1982-01-01

    Special low-rolling-resistance tires were made for DOE's ETV-1 electric vehicle. Tests were conducted on these tires and on a set of standard commercial automotive tires to determine the rolling resistance as a function of time during both constant-speed tires and SAE J227a driving cycle tests. The tests were conducted on a test track at ambient temperatures that ranged from 15 to 32 C (59 to 89 F) and with tire pressures of 207 to 276 kPa (30 to 40 psi). At a contained-air temperature of 38 C (100 F) and a pressure of 207 kPa (30 psi) the rolling resistances of the electric vehicle tires and the standard commercial tires, respectively, were 0.0102 and 0.0088 kilogram per kilogram of vehicle weight. At a contained-air temperature of 38 C (100 F) and a pressure of 276 kPa (40 psi) the rolling resistances were 0.009 and 0.0074 kilogram per kilogram of vehicle weight, respectively.

  14. HIV-1 Drug Resistance Mutations: Potential Applications for Point-of-Care Genotypic Resistance Testing

    PubMed Central

    Rhee, Soo-Yon; Jordan, Michael R.; Raizes, Elliot; Chua, Arlene; Parkin, Neil; Kantor, Rami; Van Zyl, Gert U.; Mukui, Irene; Hosseinipour, Mina C.; Frenkel, Lisa M.; Ndembi, Nicaise; Hamers, Raph L.; Rinke de Wit, Tobias F.; Wallis, Carole L.; Gupta, Ravindra K.; Fokam, Joseph; Zeh, Clement; Schapiro, Jonathan M.; Carmona, Sergio; Katzenstein, David; Tang, Michele; Aghokeng, Avelin F.; De Oliveira, Tulio; Wensing, Annemarie M. J.; Gallant, Joel E.; Wainberg, Mark A.; Richman, Douglas D.; Fitzgibbon, Joseph E.; Schito, Marco; Bertagnolio, Silvia; Yang, Chunfu; Shafer, Robert W.

    2015-01-01

    The increasing prevalence of acquired and transmitted HIV-1 drug resistance is an obstacle to successful antiretroviral therapy (ART) in the low- and middle-income countries (LMICs) hardest hit by the HIV-1 pandemic. Genotypic drug resistance testing could facilitate the choice of initial ART in areas with rising transmitted drug resistance (TDR) and enable care-providers to determine which individuals with virological failure (VF) on a first- or second-line ART regimen require a change in treatment. An inexpensive near point-of-care (POC) genotypic resistance test would be useful in settings where the resources, capacity, and infrastructure to perform standard genotypic drug resistance testing are limited. Such a test would be particularly useful in conjunction with the POC HIV-1 viral load tests that are currently being introduced in LMICs. A POC genotypic resistance test is likely to involve the use of allele-specific point mutation assays for detecting drug-resistance mutations (DRMs). This study proposes that two major nucleoside reverse transcriptase inhibitor (NRTI)-associated DRMs (M184V and K65R) and four major NNRTI-associated DRMs (K103N, Y181C, G190A, and V106M) would be the most useful for POC genotypic resistance testing in LMIC settings. One or more of these six DRMs was present in 61.2% of analyzed virus sequences from ART-naïve individuals with intermediate or high-level TDR and 98.8% of analyzed virus sequences from individuals on a first-line NRTI/NNRTI-containing regimen with intermediate or high-level acquired drug resistance. The detection of one or more of these DRMs in an ART-naïve individual or in a individual with VF on a first-line NRTI/NNRTI-containing regimen may be considered an indication for a protease inhibitor (PI)-containing regimen or closer virological monitoring based on cost-effectiveness or country policy. PMID:26717411

  15. Cooling tower irrigator layout with allowances for non-uniformity of the airflow velocity field

    NASA Astrophysics Data System (ADS)

    Pushnov, A. S.; Ryabushenko, A. S.

    2016-07-01

    This article covers the results of analysis of aerodynamic processes in the cooling tower irrigator and provides the approaches to optimal layout of preformed packing blocks (of the irrigator) developed based on these results. The analysis of the airflow velocity field in the cooling towers shows that the irrigation space can be broken down into the following zones: the peripheral zone of the cooling tower near the airblast windows, the zone near the cooling tower center, and the intermediate zone. Furthermore, the highest level of nonuniformity of the airflow velocity field in cooling towers is in the zone adjoining the tower's airblast windows. The proposed concept of the cooling tower irrigator's layout is made with allowances for the airflow velocity field characteristics in the cross-section of the irrigation space of the cooling tower. Based on this concept, we suggest that higher irrigator blocks should be placed in the zone of increased airflow consumption, which provides the possibility to enhance the hydraulic resistance and, respectively, decrease the gas flow velocity as well as to boost the efficiency of chilling the circulating water in the cooling tower. For this purpose, additional irrigator blocks can be of the same design as the main irrigator. As an option, it is possible to use blocks of the geometry and design other than the main irrigator block in the cooling tower.

  16. 49 CFR 234.267 - Insulation resistance tests, wires in trunking and cables.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Insulation resistance tests, wires in trunking and... resistance tests, wires in trunking and cables. (a) Insulation resistance tests shall be made when wires or cables are installed and at least once every ten years thereafter. (b) Insulation resistance tests...

  17. 49 CFR 234.267 - Insulation resistance tests, wires in trunking and cables.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Insulation resistance tests, wires in trunking and... resistance tests, wires in trunking and cables. (a) Insulation resistance tests shall be made when wires or cables are installed and at least once every ten years thereafter. (b) Insulation resistance tests...

  18. 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.

  19. Testing Method for Heat Resistance Under Temperature Gradient

    NASA Astrophysics Data System (ADS)

    Takagi, K.; Kawasaki, A.; Itoh, Y.; Harada, Y.; Ono, F.

    2007-12-01

    Testing Method for Heat Resistance under Temperature Gradient” is a Japanese Industrial Standard (JIS) newly established by the Minister of Economy, Trade and Industry, after deliberations by the Japanese Industrial Standards Committee, in accordance with the Industrial Standardization Law. This standard specified the testing method for heat resistance under temperature gradient of materials and coated members of equipment exposed to high temperature, such as aircraft engines, gas turbines, and so on. This paper introduces the principle and overview of the established standard. In addition, taking the heat cycle test using the burner rig for instance, we specifically illustrate the acquirable data and their analysis in the standard. Monitoring of the effective thermal conductivity and acoustic emission particularly enables to the non-destructive evaluation of failure cycle.

  20. 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

  1. Rig for testing the relative wear resistance of materials

    SciTech Connect

    Berdikov, V.F.; Diulin, A.I.; Efimchuk, V.P.; Pushkarev, O.I.; Finogenov, G.P.

    1987-01-01

    The authors have developed a simple and compact rig for studying the relative wear resistance of materials subjected to mechanical abrasion and friction. The rig has an electronic control system. It was used to test the relative wear resistance of a wide range of superhard and brittle materials under mechanical abrasion against a counterbody. The counterbody was made of modified iron and the test medium was a diamond suspension in oil. The results showed that specimen wear exhibits a linear relationship with abrasion time (in the range of 0.5-20 min.) at unit pressure from 0.01 to 0.10 MPa. That a standard wear pattern exists within a wide range of parameters indicates that abrasive conditions are highly stable and makes it possible to control conditions. The rig was used to establish the relative wear resistance of several abrasives, minerals, and refractory compounds. The very large difference (15.2 times) between the most and least-resistant materials (tungsten carbide and fluoride) illustrates the sensitivity of the methodology.

  2. 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

  3. Computational fluid dynamics (CFD) investigation of impacts of an obstruction on airflow in underground mines

    PubMed Central

    Zhou, L.; Goodman, G.; Martikainen, A.

    2015-01-01

    Continuous airflow monitoring can improve the safety of the underground work force by ensuring the uninterrupted and controlled distribution of mine ventilation to all working areas. Air velocity measurements vary significantly and can change rapidly depending on the exact measurement location and, in particular, due to the presence of obstructions in the air stream. Air velocity must be measured at locations away from obstructions to avoid the vortices and eddies that can produce inaccurate readings. Further, an uninterrupted measurement path cannot always be guaranteed when using continuous airflow monitors due to the presence of nearby equipment, personnel, roof falls and rib rolls. Effective use of these devices requires selection of a minimum distance from an obstacle, such that an air velocity measurement can be made but not affected by the presence of that obstacle. This paper investigates the impacts of an obstruction on the behavior of downstream airflow using a numerical CFD model calibrated with experimental test results from underground testing. Factors including entry size, obstruction size and the inlet or incident velocity are examined for their effects on the distributions of airflow around an obstruction. A relationship is developed between the minimum measurement distance and the hydraulic diameters of the entry and the obstruction. A final analysis considers the impacts of continuous monitor location on the accuracy of velocity measurements and on the application of minimum measurement distance guidelines. PMID:26388684

  4. 49 CFR 236.108 - Insulation resistance tests, wires in trunking and cables.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Insulation resistance tests, wires in trunking and... Insulation resistance tests, wires in trunking and cables. (a) Insulation resistance of wires and cables... dry. Insulation resistance tests shall be made between all conductors and ground, and...

  5. 49 CFR 236.108 - Insulation resistance tests, wires in trunking and cables.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Insulation resistance tests, wires in trunking and... Insulation resistance tests, wires in trunking and cables. (a) Insulation resistance of wires and cables... dry. Insulation resistance tests shall be made between all conductors and ground, and...

  6. Diaphragm injury in individuals with airflow obstruction.

    PubMed

    Macgowan, N A; Evans, K G; Road, J D; Reid, W D

    2001-06-01

    The purpose of this study was to describe the nature of diaphragm injury, to quantify the injury and number of macrophages at the light microscopic level, and to determine their association with airflow obstruction in humans. Partial-thickness diaphragm biopsies were obtained from 21 subjects going for thoracotomy surgery (FEV(1): 74 +/- 34% predicted; range: 16 to 122% predicted). Cross sections cut from frozen diaphragm were processed with H&E or processed for immunohistochemistry using the monoclonal antibody Ber-MAC3 (DAKO Corp., Carpinteria, CA) to label macrophages. Area fractions (A(A)) or the proportions of the cross- sectional area were determined by point counting all viable fields of H&E-stained diaphragm cross sections. A(A) were 66.2 +/- 9.0% for normal muscle, 17.6 +/- 7.2% for abnormal muscle, and 16.3 +/- 4.2% for connective tissue. Percent predicted FEV(1) was inversely related to the A(A) of abnormal muscle (r = -0.53, p < 0.01) and directly related to the A(A) of normal muscle (r = 0.37, p < 0.05). The number of macrophages was not related to % predicted FEV(1) (mean +/- SD: 0.41 +/- 0.18/fiber; 52 +/- 19/mm(2)). We conclude that increasing severity of airflow obstruction is associated with an increased A(A) of abnormal diaphragm and a decreased A(A) of normal diaphragm.

  7. Genotypic resistance testing in HIV by arrayed primer extension

    PubMed Central

    Bodem, Jochen; Gerhold-Ay, Aslihan; Jacob, Anette; Fellenberg, Kurt; Kräusslich, Hans-Georg; Hoheisel, Jörg D.

    2008-01-01

    The analysis of mutations that are associated with the occurrence of drug resistance is important for monitoring the antiretroviral therapy of patients infected with human immunodeficiency virus (HIV). Here, we describe the establishment and successful application of Arrayed Primer Extension (APEX) for genotypic resistance testing in HIV as a rapid and economical alternative to standard sequencing. The assay is based on an array of oligonucleotide primers that are immobilised via their 5′-ends. Upon hybridisation of template DNA, a primer extension reaction is performed in the presence of the four dideoxynucleotides, each labelled with a distinct fluorophore. The inserted label immediately indicates the sequence at the respective position. Any mutation changes the colour pattern. We designed a microarray for the analysis of 26 and 33 codons in the HIV protease and reverse transcriptase, respectively, which are of special interest with respect to drug resistance. The enormous genome variability of HIV represents a big challenge for genotypic resistance tests, which include a hybridisation step, both in terms of specificity and probe numbers. The use of degenerated oligonucleotides resulted in a significant reduction in the number of primers needed. For validation, DNA of 94 and 48 patients that exhibited resistance to inhibitors of HIV protease and reverse transcriptase, respectively, were analysed. The validation included HIV subtype B, prevalent in industrialised countries, as well as non-subtype B samples that are more common elsewhere. Electronic supplementary material The online version of this article (doi:10.1007/s00216-007-1775-0) contains supplementary material, which is available to authorized users. PMID:18202840

  8. Airflow behavior changes in upper airway caused by different head and neck positions: Comparison by computational fluid dynamics.

    PubMed

    Wei, Wei; Huang, Shi-Wei; Chen, Lian-Hua; Qi, Yang; Qiu, Yi-Min; Li, Shi-Tong

    2017-02-08

    The feasibility of computational fluid dynamics (CFD) to evaluate airflow characteristics in different head and neck positions has not been established. This study compared the changes in volume and airflow behavior of the upper airway by CFD simulation to predict the influence of anatomical and physiological airway changes due to different head-neck positions on mechanical ventilation. One awake volunteer with no risk of difficult airway underwent computed tomography in neutral position, extension position (both head and neck extended), and sniffing position (head extended and neck flexed). Three-dimensional airway models of the upper airway were reconstructed. The total volume (V) and narrowest area (Amin) of the airway models were measured. CFD simulation with an Spalart-Allmaras model was performed to characterize airflow behavior in neutral, extension, and sniffing positions of closed-mouth and open-mouth ventilation. The comparison result for V was neutral airflow rate. In sniffing position, pressure differences decreased and velocity remained almost constant. Recirculation airflow was generated near the subglottic region in neutral and extension positions. Sniffing position improves airway patency by increasing airway volume and decreasing airway resistance, suggesting that sniffing position may be the optimal choice for mask ventilation.

  9. Citric acid cough threshold and airway responsiveness in asthmatic patients and smokers with chronic airflow obstruction.

    PubMed Central

    Auffarth, B; de Monchy, J G; van der Mark, T W; Postma, D S; Koëter, G H

    1991-01-01

    The relation between citric acid cough threshold and airway hyperresponsiveness was investigated in 11 non-smoking patients with allergic asthma (mean FEV1 94% predicted) and 25 non-atopic smokers with chronic airflow obstruction (mean FEV1 65% predicted). Cough threshold was determined on two occasions by administering doubling concentrations of citric acid. Seven of the 11 asthmatic subjects and 14 of 25 smokers with chronic airflow obstruction had a positive cough threshold on both test days. Cough threshold measurements were reproducible in both groups (standard deviation of duplicate measurements 1.2 doubling concentrations in asthma, 1.1 doubling concentrations in chronic airflow obstruction). Citric acid provocation did not cause bronchial obstruction in most patients, though four patients had a fall in FEV1 of more than 20% for a short time on one occasion only. No significant difference in cough threshold was found between the two patient groups despite differences in baseline FEV1 values. There was no significant correlation between cough threshold and the provocative concentration of histamine causing a 20% fall in FEV1 (PC20) histamine in either group. Thus sensory nerves can be activated with a tussive agent in patients with asthma and chronic airflow obstruction without causing bronchial smooth muscle contraction. PMID:1948792

  10. On wind turbine power performance measurements at inclined airflow

    NASA Astrophysics Data System (ADS)

    Pedersen, T. F.

    2004-07-01

    The average airflow inclination in complex terrain may be substantial. The airflow inclination affects wind turbine performance and also affects the cup anemometer being used in power performance measurements. In this article the overall dependence of the power curve on inclined airflow is analysed for its influence on both the wind turbine and the cup anemometer. The wind turbine performance analysis is based on results of measurements and theoretical calculations with the aeroelastic code HAWC coupled to a 3D actuator disc model for varying yaw angle. The cup anemometer analysis at inclined flow is based on an averaging of measured angular characteristics in a wind tunnel with the distribution of airflow inclination angles over time. The relative difference in annual energy production in terrain with inclined airflow compared with flat terrain is simulated for cup anemometers with theoretical optimal angular characteristics for two different definitions of wind speed, as well as for five commercial cup anemometers with measured angular characteristics. Copyright

  11. Experimental Investigation of the Induced Airflow of Corona Discharge

    NASA Astrophysics Data System (ADS)

    Huang, Yong; Zhang, Xin; Wang, Xun-Nian; Wang, Wan-Bo; Huang, Zong-Bo; Li, Hua-Xing

    2013-09-01

    In order to improve the acceleration effect of corona discharge acting on air, we present an experimental study on the induced airflow produced by corona discharge between two parallel electrodes. The parameters investigated are the type of electrodes, actuation voltage and the distance in the absence of free airflow. The induced flow velocity is measured directly in the accelerated region using the particle image velocimetry technology. The results show that if corona discharge is not developed into arc discharge, the induced airflow velocity increases nearly linearly with the applied voltage and the maximum induced airflow velocity near the needle electrode reaches 36 m/s. It is expected that in the future, the result can be referred to in the research about effect of active flow control to reach much higher induced airflow speed.

  12. Hybridized electromagnetic-triboelectric nanogenerator for scavenging air-flow energy to sustainably power temperature sensors.

    PubMed

    Wang, Xue; Wang, Shuhua; Yang, Ya; Wang, Zhong Lin

    2015-04-28

    We report a hybridized nanogenerator with dimensions of 6.7 cm × 4.5 cm × 2 cm and a weight of 42.3 g that consists of two triboelectric nanogenerators (TENGs) and two electromagnetic generators (EMGs) for scavenging air-flow energy. Under an air-flow speed of about 18 m/s, the hybridized nanogenerator can deliver largest output powers of 3.5 mW for one TENG (in correspondence of power per unit mass/volume: 8.8 mW/g and 14.6 kW/m(3)) at a loading resistance of 3 MΩ and 1.8 mW for one EMG (in correspondence of power per unit mass/volume: 0.3 mW/g and 0.4 kW/m(3)) at a loading resistance of 2 kΩ, respectively. The hybridized nanogenerator can be utilized to charge a capacitor of 3300 μF to sustainably power four temperature sensors for realizing self-powered temperature sensor networks. Moreover, a wireless temperature sensor driven by a hybridized nanogenerator charged Li-ion battery can work well to send the temperature data to a receiver/computer at a distance of 1.5 m. This work takes a significant step toward air-flow energy harvesting and its potential applications in self-powered wireless sensor networks.

  13. 49 CFR 234.267 - Insulation resistance tests, wires in trunking and cables.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Insulation resistance tests, wires in trunking and... Inspections and Tests § 234.267 Insulation resistance tests, wires in trunking and cables. (a) Insulation resistance tests shall be made when wires or cables are installed and at least once every ten...

  14. 49 CFR 234.267 - Insulation resistance tests, wires in trunking and cables.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Insulation resistance tests, wires in trunking and... Inspections and Tests § 234.267 Insulation resistance tests, wires in trunking and cables. (a) Insulation resistance tests shall be made when wires or cables are installed and at least once every ten...

  15. 49 CFR 234.267 - Insulation resistance tests, wires in trunking and cables.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Insulation resistance tests, wires in trunking and... Inspections and Tests § 234.267 Insulation resistance tests, wires in trunking and cables. (a) Insulation resistance tests shall be made when wires or cables are installed and at least once every ten...

  16. 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

  17. Room airflow studies using sonic anemometry.

    PubMed

    Wasiolek, P T; Whicker, J J; Gong, H; Rodgers, J C

    1999-06-01

    To ensure prompt response by real-time air monitors to an accidental release of toxic aerosols in a workplace, safety professionals should understand airflow patterns. This understanding can be achieved with validated computational fluid dynamics (CFD) computer simulations, or with experimental techniques, such as measurements with smoke, neutrally buoyant markers, trace gases, or trace aerosol particles. As a supplementary technique to quantify airflows, the use of a state-of-the art, three-dimensional sonic anemometer was explored. This instrument allows for the precise measurements of the air-velocity vector components in the range of a few centimeters per second, which is common in many indoor work environments. Measurements of air velocities and directions at selected locations were made for the purpose of providing data for characterizing fundamental aspects of indoor air movement in two ventilated rooms and for comparison to CFD model predictions. One room was a mockup of a plutonium workroom, and the other was an actual functioning plutonium workroom. In the mockup room, air-velocity vector components were measured at 19 locations at three heights (60, 120 and 180 cm) with average velocities varying from 1.4 cm s-1 to 9.7 cm s-1. There were complex flow patterns observed with turbulence intensities from 39% up to 108%. In the plutonium workroom, measurements were made at the breathing-zone height, recording average velocities ranging from 9.9 cm s-1 to 35.5 cm s-1 with turbulence intensities from 33% to 108%.

  18. Pulmonary anatomy in the Nile crocodile and the evolution of unidirectional airflow in Archosauria

    PubMed Central

    Hutchinson, John R.; Farmer, CG

    2013-01-01

    The lungs of birds have long been known to move air in only one direction during both inspiration and expiration through most of the tubular gas-exchanging bronchi (parabronchi). Recently a similar pattern of airflow has been observed in American alligators, a sister taxon to birds. The pattern of flow appears to be due to the arrangement of the primary and secondary bronchi, which, via their branching angles, generate inspiratory and expiratory aerodynamic valves. Both the anatomical similarity of the avian and alligator lung and the similarity in the patterns of airflow raise the possibility that these features are plesiomorphic for Archosauria and therefore did not evolve in response to selection for flapping flight or an endothermic metabolism, as has been generally assumed. To further test the hypothesis that unidirectional airflow is ancestral for Archosauria, we measured airflow in the lungs of the Nile crocodile (Crocodylus niloticus). As in birds and alligators, air flows cranially to caudally in the cervical ventral bronchus, and caudally to cranially in the dorsobronchi in the lungs of Nile crocodiles. We also visualized the gross anatomy of the primary, secondary and tertiary pulmonary bronchi of C. niloticus using computed tomography (CT) and microCT. The cervical ventral bronchus, cranial dorsobronchi and cranial medial bronchi display similar characteristics to their proposed homologues in the alligator, while there is considerable variation in the tertiary and caudal group bronchi. Our data indicate that the aspects of the crocodilian bronchial tree that maintain the aerodynamic valves and thus generate unidirectional airflow, are ancestral for Archosauria. PMID:23638399

  19. Corrosion resistance tests on NiTi shape memory alloy.

    PubMed

    Rondelli, G

    1996-10-01

    The corrosion performances of NiTi shape memory alloys (SMA) in human body simulating fluids were evaluated in comparison with other implant materials. As for the passivity current in potentiostatic conditions, taken as an index of ion release, the values are about three times higher for NiTi than for Ti6Al4V and austenitic stainless steels. Regarding the localized corrosion, while plain potentiodynamic scans indicated for NiTi alloy good resistance to pitting attack similar to Ti6Al4V, tests in which the passive film is abruptly damaged (i.e. potentiostatic scratch test and modified ASTM F746) pointed out that the characteristics of the passive film formed on NiTi alloy (whose strength can be related to the alloy's biocompatibility) are not as good as those on Ti6Al4V but are comparable or inferior to those on austenitic stainless steels.

  20. 49 CFR 236.108 - Insulation resistance tests, wires in trunking and cables.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Insulation resistance tests, wires in trunking and... Insulation resistance tests, wires in trunking and cables. (a) Insulation resistance of wires and cables, except wires connected directly to track rails, shall be tested when wires, cables, and insulation...

  1. 49 CFR 236.108 - Insulation resistance tests, wires in trunking and cables.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Insulation resistance tests, wires in trunking and... Insulation resistance tests, wires in trunking and cables. (a) Insulation resistance of wires and cables, except wires connected directly to track rails, shall be tested when wires, cables, and insulation...

  2. 49 CFR 236.108 - Insulation resistance tests, wires in trunking and cables.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Insulation resistance tests, wires in trunking and... Insulation resistance tests, wires in trunking and cables. (a) Insulation resistance of wires and cables, except wires connected directly to track rails, shall be tested when wires, cables, and insulation...

  3. 30 CFR 27.39 - Tests to determine resistance to vibration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Tests to determine resistance to vibration. 27... determine resistance to vibration. (a) Laboratory tests for reliability and durability. Components.... MSHA reserves the right to conduct tests to determine resistance to vibration in underground...

  4. 30 CFR 7.407 - Test for flame resistance of electric cables and cable splices.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Test for flame resistance of electric cables... Electric Cables, Signaling Cables, and Cable Splice Kits § 7.407 Test for flame resistance of electric... to reduce contact resistance. (7) Energize all power conductors of the test specimen with...

  5. 30 CFR 27.39 - Tests to determine resistance to vibration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Tests to determine resistance to vibration. 27... determine resistance to vibration. (a) Laboratory tests for reliability and durability. Components.... MSHA reserves the right to conduct tests to determine resistance to vibration in underground...

  6. 30 CFR 7.407 - Test for flame resistance of electric cables and cable splices.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Test for flame resistance of electric cables... Electric Cables, Signaling Cables, and Cable Splice Kits § 7.407 Test for flame resistance of electric... to reduce contact resistance. (7) Energize all power conductors of the test specimen with...

  7. 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.

  8. The incompressibility assumption in computational simulations of nasal airflow.

    PubMed

    Cal, Ismael R; Cercos-Pita, Jose Luis; Duque, Daniel

    2017-04-03

    Most of the computational works on nasal airflow up to date have assumed incompressibility, given the low Mach number of these flows. However, for high temperature gradients, the incompressibility assumption could lead to a loss of accuracy, due to the temperature dependence of air density and viscosity. In this article we aim to shed some light on the influence of this assumption in a model of calm breathing in an Asian nasal cavity, by solving the fluid flow equations in compressible and incompressible formulation for different ambient air temperatures using the OpenFOAM package. At low flow rates and warm climatological conditions, similar results were obtained from both approaches, showing that density variations need not be taken into account to obtain a good prediction of all flow features, at least for usual breathing conditions. This agrees with most of the simulations previously reported, at least as far as the incompressibility assumption is concerned. However, parameters like nasal resistance and wall shear stress distribution differ for air temperatures below [Formula: see text]C approximately. Therefore, density variations should be considered for simulations at such low temperatures.

  9. 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

  10. Elasto-Aerodynamics-Driven Triboelectric Nanogenerator for Scavenging Air-Flow Energy.

    PubMed

    Wang, Shuhua; Mu, Xiaojing; Wang, Xue; Gu, Alex Yuandong; Wang, Zhong Lin; Yang, Ya

    2015-10-27

    Efficient scavenging the kinetic energy from air-flow represents a promising approach for obtaining clean, sustainable electricity. Here, we report an elasto-aerodynamics-driven triboelectric nanogenerator (TENG) based on contact electrification. The reported TENG consists of a Kapton film with two Cu electrodes at each side, fixed on two ends in an acrylic fluid channel. The relationship between the TENG output power density and its fluid channel dimensions is systematically studied. TENG with a fluid channel size of 125 × 10 × 1.6 mm(3) delivers the maximum output power density of about 9 kW/m(3) under a loading resistance of 2.3 MΩ. Aero-elastic flutter effect explains the air-flow induced vibration of Kapton film well. The output power scales nearly linearly with parallel wiring of multiple TENGs. Connecting 10 TENGs in parallel gives an output power of 25 mW, which allows direct powering of a globe light. The TENG is also utilized to scavenge human breath induced air-flow energy to sustainably power a human body temperature sensor.

  11. Effect of Airflow Exposure on the Tear Meniscus

    PubMed Central

    Koh, Shizuka; Tung, Cynthia; Kottaiyan, Ranjini; Zavislan, James; Yoon, Geunyoung; Aquavella, James

    2012-01-01

    Purpose. To compare the effect of airflow exposure on the tear meniscus and blink frequency in normal and evaporative dry eye subjects. Methods. In 9 normal subjects and 9 short tear breakup time (SBUT) dry eye subjects, lower tear meniscus height (TMH) and area (TMA) and blink frequency were measured with anterior segment optical coherence tomography (OCT) before and after 5 minutes of airflow exposure (1.5 ± 0.5 m/s). Results. In SBUT dry eyes, both TMH and TMA decreased significantly (P = 0.027, P = 0.027) with a significant increase of blink frequency after airflow exposure, while significant increase in TMA was found in normal eyes. Conclusion. Measurement of the tear meniscus with anterior segment OCT seems to be useful as a noninvasive and objective method for evaluating the effect of airflow on tear film. PMID:22570766

  12. Airflow Actuation of Shortfin Mako Shark Denticles

    NASA Astrophysics Data System (ADS)

    Devey, Sean; Hubner, Paul; Lang, Amy

    2016-11-01

    The shortfin mako shark is covered in microscopic scales called denticles, which may act as a mechanism for passive flow control. Recent research has investigated the theory that reversing flow could passively bristle these denticles, which could delay flow separation. Water tunnel studies have supported this theory, yet a wind tunnel study at a greater dynamic pressure found no significant differences between an airfoil covered with mako skin and a smooth airfoil. A likely cause is that surface tension between denticles, which must be wet to retain flexibility, prevented bristling. This would not be an issue in water. To determine what reverse airflow characteristics cause denticle bristling in air, a benchtop study was conducted in which a jet of air was impinged upon a sample of wet mako skin in the reverse flow direction. A microscope and camera captured video of the denticles under the air jet, and image analysis techniques were used to detect bristling. Analysis shows sporadic bristling around 16 m/s (q = 150 Pa) but full bristling does not occur until above 35 m/s (q = 740 Pa). The free stream velocities required to achieve such reversal speeds are much higher. For this reason, mechanical analogues will be used rather than real skin in future studies of this mechanism. Funding from Boeing and NSF REU site Grant EEC 1358991 is greatly appreciated.

  13. 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

  14. Deep resistivity structure of Yucca Flat, Nevada Test Site, Nevada

    USGS Publications Warehouse

    Asch, Theodore H.; Rodriguez, Brian D.; Sampson, Jay A.; Wallin, Erin L.; Williams, Jackie M.

    2006-01-01

    The Department of Energy (DOE) and the National Nuclear Security Administration (NNSA) at their Nevada Site Office are addressing groundwater contamination resulting from historical underground nuclear testing through the Environmental Management program and, in particular, the Underground Test Area project. One issue of concern is the nature of the somewhat poorly constrained pre Tertiary geology and its effects on ground-water flow in the area adjacent to a nuclear test. Ground water modelers would like to know more about the hydrostratigraphy and geologic structure to support a hydrostratigraphic framework model that is under development for the Yucca Flat Corrective Action Unit (CAU). During 2003, the U.S. Geological Survey, supported by the DOE and NNSA-NSO, collected and processed data from 51 magnetotelluric (MT) and audio-magnetotelluric (AMT) stations at the Nevada Test Site in and near Yucca Flat to assist in characterizing the pre-Tertiary geology in that area. The primary purpose was to refine the character, thickness, and lateral extent of pre Tertiary confining units. In particular, a major goal has been to define the upper clastic confining unit (late Devonian - Mississippian-age siliciclastic rocks assigned to the Eleana Formation and Chainman Shale) in the Yucca Flat area. The MT and AMT data have been released in separate USGS Open File Reports. The Nevada Test Site magnetotelluric data interpretation presented in this report includes the results of detailed two-dimensional (2 D) resistivity modeling for each profile (including alternative interpretations) and gross inferences on the three dimensional (3 D) character of the geology beneath each station. The character, thickness, and lateral extent of the Chainman Shale and Eleana Formation that comprise the Upper Clastic Confining Unit are generally well determined in the upper 5 km. Inferences can be made regarding the presence of the Lower Clastic Confining Unit at depths below 5 km. Large fault

  15. Improved cooling of electromagnetics by directed airflow

    NASA Astrophysics Data System (ADS)

    Fain, Adam Matthew

    The transformers in aircraft power conversion are often very heavy and represent a significant fuel or range penalty. Being thermally sized, improved cooling methods would allow downsizing and thereby reduced weight. Since the conductive paths in these metal "dense" devices are good, the controlling thermal resistance is typically the convective coefficient. The goal of this study was to optimize the convective air cooling across transformers by parametrically testing candidate shroud geometries to minimize average and hot spot surface temperatures with minimal fan power. A test set up was constructed that included a low velocity wind tunnel, fan, temperature and pressure sensors, DAQ system, and film heaters as well as the actual transformers. Experimental results from a low velocity wind tunnel were well predicted by CFD modeling, providing confidence in continued shroud development with only CFD or experimentally. Curved or bent types of shapes proved to be the most efficient shroud configurations in terms of maximizing heat transfer while reducing the energy requirement to achieve the desired level of cooling.

  16. Airflow and thrust calibration of an F100 engine, S/N P680059, at selected flight conditions

    NASA Technical Reports Server (NTRS)

    Biesiadny, T. J.; Lee, D.; Rodriguez, J. R.

    1978-01-01

    An airflow and thrust calibration of an F100 engine, S/N P680059, was conducted to study airframe propulsion system integration losses in turbofan-powered high-performance aircraft. The tests were conducted with and without thrust augmentation for a variety of simulated flight conditions with emphasis on the transonic regime. The resulting corrected airflow data generalized into one curve with corrected fan speed while corrected gross thrust increased as simulated flight conditions increased. Overall agreement between measured data and computed results was 1 percent for corrected airflow and -1 1/2 percent for gross thrust. The results of an uncertainty analysis are presented for both parameters at each simulated flight condition.

  17. Airflow synchronous with oscillatory acceleration reflects involuntary respiratory muscle activity.

    PubMed

    Brown, Richard E; Lee, Hsueh-Tze; Loring, Stephen H

    2004-06-25

    To explore mechanisms causing involuntary airflow synchronous with oscillatory axial whole body acceleration (oscillatory axial acceleration, OAA) such as that during locomotion, we monitored airflow, acceleration, and electromyograms (EMGs) of the rib cage and abdominal muscles in standing subjects undergoing OAA at 3, 6, and 9 Hz at accelerations of 0.1-0.95 g. Subjects relaxed or performed static respiratory maneuvers at constant lung volume with glottis open. Oscillatory airflows (0.01-3.01 s(-1)) synchronous with OAA were not consistent with expectations for a passive respiratory system, and were larger during active respiratory efforts than during relaxation. Peak inspiratory airflow usually preceded peak upward acceleration by 90-180 degrees. In 80% of runs with respiratory muscles voluntarily activated or relaxed, EMGs showed activity synchronous with OAA. Changes in periodic muscle activity coincided with changes in oscillatory airflow. We conclude that periodic muscle activity, probably a reflex response to body wall deformation during OAA, strongly influences the involuntary airflow synchronous with OAA.

  18. 49 CFR Appendix A to Part 179 - Procedures for Tank-Head Puncture-Resistance Test

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Procedures for Tank-Head Puncture-Resistance Test...) SPECIFICATIONS FOR TANK CARS Pt. 179, App. A Appendix A to Part 179—Procedures for Tank-Head Puncture-Resistance...-resistance systems and to test for system survivability after coupler-to-tank-head impacts at relative...

  19. 49 CFR Appendix A to Part 179 - Procedures for Tank-Head Puncture-Resistance Test

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Procedures for Tank-Head Puncture-Resistance Test... SPECIFICATIONS FOR TANK CARS Pt. 179, App. A Appendix A to Part 179—Procedures for Tank-Head Puncture-Resistance...-resistance systems and to test for system survivability after coupler-to-tank-head impacts at relative...

  20. 30 CFR 27.39 - Tests to determine resistance to vibration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Tests to determine resistance to vibration. 27... determine resistance to vibration. (a) Laboratory tests for reliability and durability. Components... two separate vibration tests, each of one-hour duration. The first test shall be conducted at...

  1. 30 CFR 27.39 - Tests to determine resistance to vibration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Tests to determine resistance to vibration. 27... determine resistance to vibration. (a) Laboratory tests for reliability and durability. Components... two separate vibration tests, each of one-hour duration. The first test shall be conducted at...

  2. 30 CFR 27.39 - Tests to determine resistance to vibration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Tests to determine resistance to vibration. 27... determine resistance to vibration. (a) Laboratory tests for reliability and durability. Components... two separate vibration tests, each of one-hour duration. The first test shall be conducted at...

  3. 30 CFR 14.22 - Test for flame resistance of conveyor belts.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Test for flame resistance of conveyor belts. 14.22 Section 14.22 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING... Technical Requirements § 14.22 Test for flame resistance of conveyor belts. (a) Test procedures. The...

  4. 30 CFR 7.27 - Test for flame resistance of brattice cloth.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Test for flame resistance of brattice cloth. 7.27 Section 7.27 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING... Ventilation Tubing § 7.27 Test for flame resistance of brattice cloth. (a) Test procedures. (1) Prepare...

  5. 16 CFR 1203.15 - Positional stability test (roll-off resistance).

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 16 Commercial Practices 2 2011-01-01 2011-01-01 false Positional stability test (roll-off resistance). 1203.15 Section 1203.15 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION CONSUMER PRODUCT... test (roll-off resistance). (a) Test equipment. (1) Headforms. The test headforms shall comply with...

  6. 30 CFR 7.27 - Test for flame resistance of brattice cloth.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Test for flame resistance of brattice cloth. 7.27 Section 7.27 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING... Ventilation Tubing § 7.27 Test for flame resistance of brattice cloth. (a) Test procedures. (1) Prepare...

  7. 30 CFR 14.22 - Test for flame resistance of conveyor belts.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Test for flame resistance of conveyor belts. 14.22 Section 14.22 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING... Technical Requirements § 14.22 Test for flame resistance of conveyor belts. (a) Test procedures. The...

  8. 16 CFR 1203.15 - Positional stability test (roll-off resistance).

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Positional stability test (roll-off resistance). 1203.15 Section 1203.15 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION CONSUMER PRODUCT... test (roll-off resistance). (a) Test equipment. (1) Headforms. The test headforms shall comply with...

  9. 30 CFR 14.22 - Test for flame resistance of conveyor belts.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Test for flame resistance of conveyor belts. 14.22 Section 14.22 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING... Technical Requirements § 14.22 Test for flame resistance of conveyor belts. (a) Test procedures. The...

  10. 30 CFR 14.22 - Test for flame resistance of conveyor belts.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Test for flame resistance of conveyor belts. 14.22 Section 14.22 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING... Technical Requirements § 14.22 Test for flame resistance of conveyor belts. (a) Test procedures. The...

  11. 16 CFR 1203.15 - Positional stability test (roll-off resistance).

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 16 Commercial Practices 2 2014-01-01 2014-01-01 false Positional stability test (roll-off resistance). 1203.15 Section 1203.15 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION CONSUMER PRODUCT... test (roll-off resistance). (a) Test equipment. (1) Headforms. The test headforms shall comply with...

  12. 16 CFR 1203.15 - Positional stability test (roll-off resistance).

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 16 Commercial Practices 2 2013-01-01 2013-01-01 false Positional stability test (roll-off resistance). 1203.15 Section 1203.15 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION CONSUMER PRODUCT... test (roll-off resistance). (a) Test equipment. (1) Headforms. The test headforms shall comply with...

  13. 16 CFR 1203.15 - Positional stability test (roll-off resistance).

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 16 Commercial Practices 2 2012-01-01 2012-01-01 false Positional stability test (roll-off resistance). 1203.15 Section 1203.15 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION CONSUMER PRODUCT... test (roll-off resistance). (a) Test equipment. (1) Headforms. The test headforms shall comply with...

  14. 30 CFR 7.27 - Test for flame resistance of brattice cloth.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Test for flame resistance of brattice cloth. 7.27 Section 7.27 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING... Ventilation Tubing § 7.27 Test for flame resistance of brattice cloth. (a) Test procedures. (1) Prepare...

  15. 30 CFR 7.27 - Test for flame resistance of brattice cloth.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Test for flame resistance of brattice cloth. 7.27 Section 7.27 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING... Ventilation Tubing § 7.27 Test for flame resistance of brattice cloth. (a) Test procedures. (1) Prepare...

  16. 30 CFR 14.22 - Test for flame resistance of conveyor belts.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Test for flame resistance of conveyor belts. 14.22 Section 14.22 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING... Technical Requirements § 14.22 Test for flame resistance of conveyor belts. (a) Test procedures. The...

  17. 30 CFR 7.27 - Test for flame resistance of brattice cloth.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Test for flame resistance of brattice cloth. 7.27 Section 7.27 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING... Ventilation Tubing § 7.27 Test for flame resistance of brattice cloth. (a) Test procedures. (1) Prepare...

  18. Robust Unidirectional Airflow through Avian Lungs: New Insights from a Piecewise Linear Mathematical Model

    PubMed Central

    Harvey, Emily P.; Ben-Tal, Alona

    2016-01-01

    Avian lungs are remarkably different from mammalian lungs in that air flows unidirectionally through rigid tubes in which gas exchange occurs. Experimental observations have been able to determine the pattern of gas flow in the respiratory system, but understanding how the flow pattern is generated and determining the factors contributing to the observed dynamics remains elusive. It has been hypothesized that the unidirectional flow is due to aerodynamic valving during inspiration and expiration, resulting from the anatomical structure and the fluid dynamics involved, however, theoretical studies to back up this hypothesis are lacking. We have constructed a novel mathematical model of the airflow in the avian respiratory system that can produce unidirectional flow which is robust to changes in model parameters, breathing frequency and breathing amplitude. The model consists of two piecewise linear ordinary differential equations with lumped parameters and discontinuous, flow-dependent resistances that mimic the experimental observations. Using dynamical systems techniques and numerical analysis, we show that unidirectional flow can be produced by either effective inspiratory or effective expiratory valving, but that both inspiratory and expiratory valving are required to produce the high efficiencies of flows observed in avian lungs. We further show that the efficacy of the inspiratory and expiratory valving depends on airsac compliances and airflow resistances that may not be located in the immediate area of the valving. Our model provides additional novel insights; for example, we show that physiologically realistic resistance values lead to efficiencies that are close to maximum, and that when the relative lumped compliances of the caudal and cranial airsacs vary, it affects the timing of the airflow across the gas exchange area. These and other insights obtained by our study significantly enhance our understanding of the operation of the avian respiratory

  19. Deep Resistivity Structure of Mid Valley, Nevada Test Site, Nevada

    USGS Publications Warehouse

    Wallin, Erin L.; Rodriguez, Brian D.; Williams, Jackie M.

    2009-01-01

    -Tertiary confining units. In particular, a major goal was to define the extent of the upper clastic confining unit (UCCU). The UCCU is composed of late Devonian to Mississippian siliciclastic rocks assigned to the Eleana Formation and Chainman Shale (National Security Technologies, 2007). The UCCU underlies the Yucca Flat area and extends southwestward toward Shoshone Mountain, westward toward Buckboard Mesa, and northwestward toward Rainier Mesa. Late in 2005 we collected data at an additional 14 MT stations in Mid Valley, CP Hills, and northern Yucca Flat. That work was done to better determine the extent and thickness of the UCCU near the boundary between the southeastern RM-SM CAU and the southwestern YF CAU, and also in the northern YF CAU. The MT data have been released in a separate U.S. Geological Survey report (Williams and others, 2007). The Nevada Test Site magnetotelluric data interpretation presented in this report includes the results of detailed two-dimensional (2-D) resistivity modeling for each profile and inferences on the three-dimensional (3-D) character of the geology within the region.

  20. Airflow calibration and exhaust pressure/temperature survey of an F404, S/N 215-109, turbofan engine

    NASA Technical Reports Server (NTRS)

    Burns, Maureen E.; Kirchgessner, Thomas A.

    1987-01-01

    A General Electric F-404 turbofan engine was calibrated for thrust and airflow at the NASA Lewis Propulsion System Laboratory in support of future flight tests of the X-29 aircraft. Tests were conducted with and without augmentation, over a range of flight conditions, including the two design points of the airplane. Data obtained during the altitude tests will be used to correct two independent gross thrust calculation routines which will be installed and operated on the airplane to determine in-flight gross thrust. Corrected airflow data as a function of corrected fan speed collapsed onto a single curve. Similarly, trends were observed and defined for both augmented and dry thrust. Overall agreement between measured data and F-404 Engine Spec Deck data was within 2 percent for airflow and 6 percent for thrust. The results of an uncertainty analysis for thrust and airflow is presented. In addition to the thrust calibration, the exhaust gas boundary layer pressure and temperatures were surveyed at selected condition and engine power levels to obtain data for another NASA F-404 program. Test data for these surveys are presented.

  1. Conspiracies and Test Compromise: An Evaluation of the Resistance of Test Systems to Small-Scale Cheating

    ERIC Educational Resources Information Center

    Guo, Jing; Tay, Louis; Drasgow, Fritz

    2009-01-01

    Test compromise is a concern in cognitive ability testing because such tests are widely used in employee selection and administered on a continuous basis. In this study, the resistance of cognitive tests, deployed in different test systems, to small-scale cheating conspiracies, was evaluated regarding the accuracy of ability estimation.…

  2. D test: a simple test with big implication for Staphylococcus aureus macrolide-lincosamide-streptograminB resistance pattern.

    PubMed

    Shrestha, B; Rana, S S

    2014-09-01

    D test is a simple disc diffusion test giving high throughput results. It is used to study the macrolide lincosamide streptogramin resistance (MLSB), both constitutive and inducible as well as macrolide streptogramin resistance (MSB) in Staphylococcus aureus. In this test, erythromycin (macrolide) and clindamycin (lincosamide derivative) discs are placed adjacent to each other over the Mueller Hinton agar medium inoculated with the test organism. The growth of the organism up to the edges of the disc, flattening of the clindamycin zone (D test positive) near the erythromycin disc (resistant) and susceptible to both antibiotics implicate that the organism is having constitutive MLSB (CMLSB), inducible MLSB (IMLSB) and no resistance respectively. Further, the organism susceptible to clindamycin without any flattening of the zone (D test negative) near clindamycin disc (resistant) implicates that the organism is having macrolide streptogramin resistance (MSB). The test is performed in the same MHA plate in which the antibiotic sensitivity test is being done, taking into consideration that the discs are placed adjacent to each other maintaining the distance. Since clindamycin and streptogramin are among the few drugs of choice in the treatment of methicillin resistant S. aureus (MRSA) infections, knowing the resistance to these antibiotics is imperative.

  3. [Drug resistance testing of Mycobacterium tuberculosis isolates from sputum in Chad].

    PubMed

    Abdelhadi, O; Ndokaïn, J; Ali, M Moussa; Friocourt, V; Mortier, E; Heym, B

    2012-02-01

    Culture and resistance testing of Mycobacterium tuberculosis are not regularly performed in Chad. Sputa were obtained from three different categories of hospitals (district, regional and national) in Chad. All examined sputa were smear-positive and were investigated by culture and drug resistance testing for first-line antituberculosis drugs. From 232 sputa positive for acid-fast bacilli, 135 isolates of M. tuberculosis from different patients (46 women, 89 men, mean age 34 years) were analyzed. All the patients except one corresponded to new cases of tuberculosis. In total, 27 out of 135 isolates (20%) were resistant to at least one major antituberculosis drug. Resistance to isoniazid was the most frequent resistance observed, with 18 isolates (13%) presenting at least this resistance. Three isolates (2.2%) were resistant to isoniazid and rifampicin (multidrug resistance MDR) including one isolate being concomitantly resistant to streptomycin and ethambutol. The resistance rate differed in relation to the category of the hospital; the most important resistance rate was observed in regional hospitals (33%), while it was 16% and 14% in the national and district hospitals, respectively. HIV serology was performed in 81 patients, among whom 20 (25%) were positive. This is the first study that shows that drug resistance of M. tuberculosis is present in Chad. Besides single drug-resistant isolates, multidrug-resistant strains of M. tuberculosis could also be identified. This result highlights the urgency of initiating actions to detect drug resistance and limit the spread of drug-resistant strains.

  4. Simple PCR Assays Improve the Sensitivity of HIV-1 Subtype B Drug Resistance Testing and Allow Linking of Resistance Mutations

    PubMed Central

    Johnson, Jeffrey A.; Li, Jin-Fen; Wei, Xierong; Lipscomb, Jonathan; Bennett, Diane; Brant, Ashley; Cong, Mian-er; Spira, Thomas; Shafer, Robert W.; Heneine, Walid

    2007-01-01

    Background The success of antiretroviral therapy is known to be compromised by drug-resistant HIV-1 at frequencies detectable by conventional bulk sequencing. Currently, there is a need to assess the clinical consequences of low-frequency drug resistant variants occurring below the detection limit of conventional genotyping. Sensitive detection of drug-resistant subpopulations, however, requires simple and practical methods for routine testing. Methodology We developed highly-sensitive and simple real-time PCR assays for nine key drug resistance mutations and show that these tests overcome substantial sequence heterogeneity in HIV-1 clinical specimens. We specifically used early wildtype virus samples from the pre-antiretroviral drug era to measure background reactivity and were able to define highly-specific screening cut-offs that are up to 67-fold more sensitive than conventional genotyping. We also demonstrate that sequencing the mutation-specific PCR products provided a direct and novel strategy to further detect and link associated resistance mutations, allowing easy identification of multi-drug-resistant variants. Resistance mutation associations revealed in mutation-specific amplicon sequences were verified by clonal sequencing. Significance Combined, sensitive real-time PCR testing and mutation-specific amplicon sequencing provides a powerful and simple approach that allows for improved detection and evaluation of HIV-1 drug resistance mutations. PMID:17653265

  5. Risk factors for persistent airflow limitation: Analysis of 306 patients with asthma

    PubMed Central

    Wang, Lingcheng; Gao, Shuncui; Zhu, Wei; Su, Jun

    2014-01-01

    Objectives : To determine the risk factors associated with persistent airflow limitation in patients with asthma. Method s: This study was designed and carried out in the department of respiratory medicine, fourth People’s Hospital of Jinan City, Shandong province, China between Jan 2012 and Dec 2012. Three hundred and six asthma patients participating in the study were divided into persistent airflow limitation group (PAFL) and no persistent airflow limitation group (NPAFL). The patients participated in pulmonary function tests and sputum induction examination. The clinical data including age, gender, onset age, disease course, smoking history, family history, regular corticosteroid inhalation, hospitalization history and presence of atopy were collected. Results : In 306 patients, 128 (40.5%) were included in PAFL group and 178(59.5%) in NPAFL group. Multivariate analysis demonstrated smoking (≥10 pack-years; OR, 7.1; 95% CI, 1.8 to 31.2), longer asthma duration (≥ 20years) (OR, 6.3; 95% CI, 1.7 to 28.5), absence of regular corticosteroid inhalation (OR, 3.5; 95% CI, 1.1 to 14.5) and neutrophil in induced sputum≥65% (OR, 1.8; 95% CI, 1.0 to 2.8) were independent risk factors for PAFL. Conclusions : Smoking, longer asthma duration and increased neutrophil in induced sputum are risk factors for PAFL, while regular corticosteroid inhalation is protective factor. Smoking cessation and regular corticosteroid inhalation may play an important role in preventing the occurrence of persistent airflow limitation group (PAFL). PMID:25674145

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

    NASA Astrophysics Data System (ADS)

    Cho, Young-Hum

    Single duct Variable Air Volume (VAV) systems are currently the most widely used type of HVAC system in the United States. When installing such a system, it is critical to determine the minimum airflow set point of the terminal box, as an optimally selected set point will improve the level of thermal comfort and indoor air quality (IAQ) while at the same time lower overall energy costs. In principle, this minimum rate should be calculated according to the minimum ventilation requirement based on ASHRAE standard 62.1 and maximum heating load of the zone. Several factors must be carefully considered when calculating this minimum rate. Terminal boxes with conventional control sequences may result in occupant discomfort and energy waste. If the minimum rate of airflow is set too high, the AHUs will consume excess fan power, and the terminal boxes may cause significant simultaneous room heating and cooling. At the same time, a rate that is too low will result in poor air circulation and indoor air quality in the air-conditioned space. Currently, many scholars are investigating how to change the algorithm of the advanced VAV terminal box controller without retrofitting. Some of these controllers have been found to effectively improve thermal comfort, indoor air quality, and energy efficiency. However, minimum airflow set points have not yet been identified, nor has controller performance been verified in confirmed studies. In this study, control algorithms were developed that automatically identify and reset terminal box minimum airflow set points, thereby improving indoor air quality and thermal comfort levels, and reducing the overall rate of energy consumption. A theoretical analysis of the optimal minimum airflow and discharge air temperature was performed to identify the potential energy benefits of resetting the terminal box minimum airflow set points. Applicable control algorithms for calculating the ideal values for the minimum airflow reset were developed and

  7. 49 CFR Appendix A to Part 179 - Procedures for Tank-Head Puncture-Resistance Test

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Procedures for Tank-Head Puncture-Resistance Test...) SPECIFICATIONS FOR TANK CARS Pt. 179, App. A Appendix A to Part 179—Procedures for Tank-Head Puncture-Resistance Test 1. This test procedure is designed to verify the integrity of new or untried tank-head...

  8. 49 CFR Appendix A to Part 179 - Procedures for Tank-Head Puncture-Resistance Test

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Procedures for Tank-Head Puncture-Resistance Test...) SPECIFICATIONS FOR TANK CARS Pt. 179, App. A Appendix A to Part 179—Procedures for Tank-Head Puncture-Resistance Test 1. This test procedure is designed to verify the integrity of new or untried tank-head...

  9. Tests for resistivity boundary changes at Ohaaki, New Zealand

    SciTech Connect

    Risk, G.F.

    1994-01-20

    Close-spaced resistivity measurements along ten traverse lines crossing the resistivity boundary of the Ohaaki Geothermal Field, New Zealand, were first measured in 1975 and remeasured in 1992. The 1992 resistivity profiles were similar in shape to the original ones. On both occasions very sharp resistivity boundaries were delineated along the southern and southwestern edges of the field where apparent resistivity rises sharply over a horizontal distance of a few hundred metres from 2-5 ohm m on the inside of the field to 20-50 ohm m on the outside. On two of the southern lines the resistivity boundary appears to have moved outwards by about 100 m, which may be caused by southward movement of reinjected waste water from nearby drillholes. On the other southern lines the outward movement appears to be less than about 25 m, which is the limit of resolution of the survey. Over the 17 year interval apparent resistivity values have dropped slightly at most measurement sites. The decrease is more pronounced on the inside of the field boundary where apparent resistivities have declined by up to about 40 percent. Some of this decrease is attributed to reinjection of conductive waste water near the field boundary causing a drop in ground resistivity. Part of this change may be due to calibration errors and measurement difficulties, including the disturbing effects of the new drillholes, steam pipes and an earthing mat that have been installed since 1975.

  10. 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)

  11. Investigating extremely low resistance ohmic contacts to silicon carbide using a novel test structure

    NASA Astrophysics Data System (ADS)

    Pan, Yue; Collins, Aaron M.; Algahtani, Fahid; Leech, Patrick W.; Reeves, Geoffrey K.; Tanner, Philip; Holland, Anthony S.

    2013-12-01

    Low resistance contracts to highly doped silicon carbide (SiC) are investigated. Using a novel test structure that is easy to fabricate and easy to use, this paper demonstrates how it is used to reliably determine relatively low specific contact resistivities which vary with heat treatment. The test structure requires no error correction and is not affected by parasitic resistances. Using the test structure, small changes in specific contact resistivity are determined for small temperature changes. Results will be presented and discussed on the application of this novel test structure for nickel to highly doped SiC.

  12. Comparison of pulmonary function in patients with COPD, asthma-COPD overlap syndrome, and asthma with airflow limitation

    PubMed Central

    Kitaguchi, Yoshiaki; Yasuo, Masanori; Hanaoka, Masayuki

    2016-01-01

    Background This study was conducted in order to investigate the differences in the respiratory physiology of patients with chronic obstructive pulmonary disease (COPD), asthma-COPD overlap syndrome (ACOS), and asthma with airflow limitation (asthma FL+). Methods The medical records for a series of all stable patients with persistent airflow limitation due to COPD, ACOS, or asthma were retrospectively reviewed and divided into the COPD group (n=118), the ACOS group (n=32), and the asthma FL+ group (n=27). All the patients underwent chest high-resolution computed tomography (HRCT) and pulmonary function tests, including respiratory impedance. Results The low attenuation area score on chest HRCT was significantly higher in the COPD group than in the ACOS group (9.52±0.76 vs 5.09±1.16, P<0.01). The prevalence of bronchial wall thickening on chest HRCT was significantly higher in the asthma FL+ group than in the COPD group (55.6% vs 25.0%, P<0.01). In pulmonary function, forced expiratory volume in 1 second (FEV1) and peak expiratory flow rate were significantly higher in the asthma FL+ group than in the ACOS group (76.28%±2.54% predicted vs 63.43%±3.22% predicted, P<0.05 and 74.40%±3.16% predicted vs 61.08%±3.54% predicted, P<0.05, respectively). Although residual volume was significantly lower in the asthma FL+ group than in the COPD group (112.05%±4.34% predicted vs 137.38%±3.43% predicted, P<0.01) and the ACOS group (112.05%±4.34% predicted vs148.46%±6.25% predicted, P<0.01), there were no significant differences in functional residual capacity or total lung capacity. The increase in FEV1 in response to short-acting β2-agonists was significantly greater in the ACOS group than in the COPD group (229±29 mL vs 72±10 mL, P<0.01) and the asthma FL+ group (229±29 mL vs 153±21 mL, P<0.05). Regarding respiratory impedance, resistance at 5 Hz and resistance at 20 Hz, which are oscillatory parameters of respiratory resistance, were significantly higher in the

  13. Experimental investigation into the interaction between the human body and room airflow and its effect on thermal comfort under stratum ventilation.

    PubMed

    Cheng, Y; Lin, Z

    2016-04-01

    Room occupants' comfort and health are affected by the airflow. Nevertheless, they themselves also play an important role in indoor air distribution. This study investigated the interaction between the human body and room airflow under stratum ventilation. Simplified thermal manikin was employed to effectively resemble the human body as a flow obstacle and/or free convective heat source. Unheated and heated manikins were designed to fully evaluate the impact of the manikin at various airflow rates. Additionally, subjective human tests were conducted to evaluate thermal comfort for the occupants in two rows. The findings show that the manikin formed a local blockage effect, but the supply airflow could flow over it. With the body heat from the manikin, the air jet penetrated farther compared with that for the unheated manikin. The temperature downstream of the manikin was also higher because of the convective effect. Elevating the supply airflow rate from 7 to 15 air changes per hour varied the downstream airflow pattern dramatically, from an uprising flow induced by body heat to a jet-dominated flow. Subjective assessments indicated that stratum ventilation provided thermal comfort for the occupants in both rows. Therefore, stratum ventilation could be applied in rooms with occupants in multiple rows.

  14. Preparation and testing of corrosion and spallation-resistant coatings

    SciTech Connect

    Hurley, John P.; Cavalli, Matthew N.

    2016-06-30

    The goal of this project was to take a recently developed method of bonding oxide dispersion-strengthened (ODS) FeCrAl plating to nickel superalloys closer to commercial use in syngas-fired turbines. The project was designed to better understand and develop the bonding process and to determine if plating APMT®, a specific highly oxidation-resistant ODS FeCrAl alloy made by Kanthal, onto nickel-based superalloy turbine parts is a viable method for substantially improving the lifetimes and maximum use temperatures of the parts. The superalloys investigated for protection were CM247LC and Rene® 80, both alumina scale-forming alloys. The method for bonding the APMT plate to the superalloys is called evaporative metal bonding, which involves placing a thin foil of zinc between the plate and the superalloy, clamping them together, and heating in an atmosphere-controlled furnace. Upon heating, the zinc melts and dissolves the oxide skins of the alloys at the bond line, allowing the two alloys to diffuse into each other. The zinc then diffuses through the alloys and evaporates from their surfaces, creating a bond between the APMT and the superalloy that is stronger than the APMT itself. Testing showed that the diffusivity of zinc in both APMT and CM247LC is quite similar at 700°C but 15 times higher in the APMT at 1214°C. Coefficients of thermal expansion were determined for each of the alloys as a function of temperature. This information was entered into a finite-element model using ANSYS, which was used to design a clamping jig for pressing the APMT to the superalloys at the bonding temperature. Scanning electron microscopy analyses of representative joints showed that no zinc remained in the alloys after bonding Unfortunately, the analyses also showed some small pieces of broken aluminum oxide scale near the bond lines, indicating that its scale was not sufficiently removed during prebonding cleaning. Samples from each of the bonded blocks were sent to Siemens for

  15. Comparison of two versions of larval development test to detect anthelmintic resistance in Haemonchus contortus.

    PubMed

    Várady, Marián; Corba, Július; Letková, Valéria; Kovác, Gabriel

    2009-03-23

    Larval development (LDT) and micro-agar larval development tests (MALDT) were used to compare the reliability and sensitivity of two methods for detecting anthelmintic resistance in Haemonchus contortus. The tests were conducted using three resistant and four susceptible isolates of H. contortus. Both versions of the tests provided comparable results with regard to the characterization of benzimidazole and levamisole susceptibility but neither test was sufficiently sensitive to discrimination between an ivermectin (IVM) susceptible and an IVM resistant isolate. Each test has its own merits with the LDT having the advantage of being less time-consuming.

  16. Emerging Rapid Resistance Testing Methods for Clinical Microbiology Laboratories and Their Potential Impact on Patient Management

    PubMed Central

    Frickmann, Hagen; Zautner, Andreas E.

    2014-01-01

    Atypical and multidrug resistance, especially ESBL and carbapenemase expressing Enterobacteriaceae, is globally spreading. Therefore, it becomes increasingly difficult to achieve therapeutic success by calculated antibiotic therapy. Consequently, rapid antibiotic resistance testing is essential. Various molecular and mass spectrometry-based approaches have been introduced in diagnostic microbiology to speed up the providing of reliable resistance data. PCR- and sequencing-based approaches are the most expensive but the most frequently applied modes of testing, suitable for the detection of resistance genes even from primary material. Next generation sequencing, based either on assessment of allelic single nucleotide polymorphisms or on the detection of nonubiquitous resistance mechanisms might allow for sequence-based bacterial resistance testing comparable to viral resistance testing on the long term. Fluorescence in situ hybridization (FISH), based on specific binding of fluorescence-labeled oligonucleotide probes, provides a less expensive molecular bridging technique. It is particularly useful for detection of resistance mechanisms based on mutations in ribosomal RNA. Approaches based on MALDI-TOF-MS, alone or in combination with molecular techniques, like PCR/electrospray ionization MS or minisequencing provide the fastest resistance results from pure colonies or even primary samples with a growing number of protocols. This review details the various approaches of rapid resistance testing, their pros and cons, and their potential use for the diagnostic laboratory. PMID:25343142

  17. Preparation and testing of corrosion and spallation-resistant coatings

    SciTech Connect

    Hurley, John

    2012-09-30

    This Energy & Environmental Research Center (EERC) project is designed to determine if plating APMT, a specific highly oxidation-resistant oxide dispersion-strengthened FeCrAl alloy made by Kanthal, onto nickel-based superalloy turbine parts is a viable method for substantially improving the lifetimes and maximum use temperatures of the parts. The method for joining the APMT plate to the superalloys is called evaporative metal bonding. It involves placing a thin foil of zinc (Zn) between the plate and the superalloy, clamping them together, and heating in an atmosphere-controlled furnace. Upon heating, the Zn melts and dissolves the oxide skins of the alloys at the bond line, allowing the two alloys to diffuse into each other. The Zn then diffuses through the alloys and evaporates from their surfaces. Laboratory testing has shown that the diffusion rate of Zn through the FeCrAl alloy is much faster than through the nickel superalloys. This means that the FeCrAl will serve as a sink for the Zn bonding alloy during the evaporative metal bonding process. Also, the testing has shown that the Zn diffusion mechanism is bulk diffusion, and not intergranular. This is a surprise. However, it means that quantification of the Zn diffusivities in these samples will be significantly simpler than would have been the case if grain boundary diffusion dominated. In addition to the laboratory testing, gas impinger and particulate samples are being collected from a combustor firing syngas and natural gas to determine what types of microcontaminants may reach a turbine firing syngas. The syngas is created in one of two different pilot-scale pressurized coal gasifiers. The initial analysis of the impinger solutions was for standard U.S. Environmental Protection Agency (EPA) Method 29 determination of hazardous metals and did not include major element analysis. When syngas is fired, the amount of Mn in the combustor gas increases substantially. Halogens (Br2 and Cl2) and hydrogen

  18. 30 CFR 7.407 - Test for flame resistance of electric cables and cable splices.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...) at an ambient temperature of 104 °F (40 °C). (8) Monitor the electric current through the power... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Test for flame resistance of electric cables... Electric Cables, Signaling Cables, and Cable Splice Kits § 7.407 Test for flame resistance of...

  19. 30 CFR 7.407 - Test for flame resistance of electric cables and cable splices.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...) at an ambient temperature of 104 °F (40 °C). (8) Monitor the electric current through the power... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Test for flame resistance of electric cables... Electric Cables, Signaling Cables, and Cable Splice Kits § 7.407 Test for flame resistance of...

  20. 30 CFR 7.407 - Test for flame resistance of electric cables and cable splices.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...) at an ambient temperature of 104 °F (40 °C). (8) Monitor the electric current through the power... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Test for flame resistance of electric cables... Electric Cables, Signaling Cables, and Cable Splice Kits § 7.407 Test for flame resistance of...

  1. 49 CFR Appendix E to Part 178 - Flame Penetration Resistance Test

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Flame Penetration Resistance Test E Appendix E to Part 178 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS... PACKAGINGS Pt. 178, App. E Appendix E to Part 178—Flame Penetration Resistance Test (a) Criteria...

  2. 30 CFR 7.408 - Test for flame resistance of signaling cables.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Test for flame resistance of signaling cables. 7.408 Section 7.408 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR..., Signaling Cables, and Cable Splice Kits § 7.408 Test for flame resistance of signaling cables. (a)...

  3. 49 CFR Appendix E to Part 178 - Flame Penetration Resistance Test

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Flame Penetration Resistance Test E Appendix E to Part 178 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS.... 178, App. E Appendix E to Part 178—Flame Penetration Resistance Test (a) Criteria for Acceptance....

  4. 30 CFR 7.28 - Test for flame resistance of rigid ventilation tubing.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Test for flame resistance of rigid ventilation tubing. 7.28 Section 7.28 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... and Ventilation Tubing § 7.28 Test for flame resistance of rigid ventilation tubing. (a)...

  5. 30 CFR 27.40 - Test to determine resistance to dust.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Test to determine resistance to dust. 27.40 Section 27.40 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING... determine resistance to dust. Components, subassemblies, or assemblies, the normal functioning of...

  6. 30 CFR 7.28 - Test for flame resistance of rigid ventilation tubing.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Test for flame resistance of rigid ventilation tubing. 7.28 Section 7.28 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... and Ventilation Tubing § 7.28 Test for flame resistance of rigid ventilation tubing. (a)...

  7. 30 CFR 27.40 - Test to determine resistance to dust.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Test to determine resistance to dust. 27.40 Section 27.40 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING... determine resistance to dust. Components, subassemblies, or assemblies, the normal functioning of...

  8. 30 CFR 7.408 - Test for flame resistance of signaling cables.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Test for flame resistance of signaling cables. 7.408 Section 7.408 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR..., Signaling Cables, and Cable Splice Kits § 7.408 Test for flame resistance of signaling cables. (a)...

  9. 30 CFR 27.41 - Test to determine resistance to moisture.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Test to determine resistance to moisture. 27.41 Section 27.41 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING... determine resistance to moisture. Components, subassemblies, or assemblies, the normal functioning of...

  10. 30 CFR 27.41 - Test to determine resistance to moisture.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Test to determine resistance to moisture. 27.41 Section 27.41 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING... determine resistance to moisture. Components, subassemblies, or assemblies, the normal functioning of...

  11. 30 CFR 7.28 - Test for flame resistance of rigid ventilation tubing.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Test for flame resistance of rigid ventilation tubing. 7.28 Section 7.28 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... and Ventilation Tubing § 7.28 Test for flame resistance of rigid ventilation tubing. (a)...

  12. 49 CFR Appendix E to Part 178 - Flame Penetration Resistance Test

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Flame Penetration Resistance Test E Appendix E to Part 178 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS.... 178, App. E Appendix E to Part 178—Flame Penetration Resistance Test (a) Criteria for Acceptance....

  13. 49 CFR Appendix E to Part 178 - Flame Penetration Resistance Test

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Flame Penetration Resistance Test E Appendix E to Part 178 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS.... 178, App. E Appendix E to Part 178—Flame Penetration Resistance Test (a) Criteria for Acceptance....

  14. 30 CFR 7.408 - Test for flame resistance of signaling cables.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Test for flame resistance of signaling cables. 7.408 Section 7.408 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR..., Signaling Cables, and Cable Splice Kits § 7.408 Test for flame resistance of signaling cables. (a)...

  15. 30 CFR 7.28 - Test for flame resistance of rigid ventilation tubing.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Test for flame resistance of rigid ventilation tubing. 7.28 Section 7.28 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... and Ventilation Tubing § 7.28 Test for flame resistance of rigid ventilation tubing. (a)...

  16. 30 CFR 7.408 - Test for flame resistance of signaling cables.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Test for flame resistance of signaling cables. 7.408 Section 7.408 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR..., Signaling Cables, and Cable Splice Kits § 7.408 Test for flame resistance of signaling cables. (a)...

  17. 30 CFR 27.40 - Test to determine resistance to dust.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Test to determine resistance to dust. 27.40 Section 27.40 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING... determine resistance to dust. Components, subassemblies, or assemblies, the normal functioning of...

  18. 30 CFR 7.408 - Test for flame resistance of signaling cables.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Test for flame resistance of signaling cables. 7.408 Section 7.408 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR..., Signaling Cables, and Cable Splice Kits § 7.408 Test for flame resistance of signaling cables. (a)...

  19. 30 CFR 27.40 - Test to determine resistance to dust.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Test to determine resistance to dust. 27.40 Section 27.40 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING... determine resistance to dust. Components, subassemblies, or assemblies, the normal functioning of...

  20. 30 CFR 27.41 - Test to determine resistance to moisture.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Test to determine resistance to moisture. 27.41 Section 27.41 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING... determine resistance to moisture. Components, subassemblies, or assemblies, the normal functioning of...

  1. 30 CFR 27.41 - Test to determine resistance to moisture.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Test to determine resistance to moisture. 27.41 Section 27.41 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING... determine resistance to moisture. Components, subassemblies, or assemblies, the normal functioning of...

  2. 30 CFR 7.28 - Test for flame resistance of rigid ventilation tubing.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Test for flame resistance of rigid ventilation tubing. 7.28 Section 7.28 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... and Ventilation Tubing § 7.28 Test for flame resistance of rigid ventilation tubing. (a)...

  3. 30 CFR 27.41 - Test to determine resistance to moisture.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Test to determine resistance to moisture. 27.41 Section 27.41 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING... determine resistance to moisture. Components, subassemblies, or assemblies, the normal functioning of...

  4. 49 CFR Appendix E to Part 178 - Flame Penetration Resistance Test

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Flame Penetration Resistance Test E Appendix E to Part 178 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS.... 178, App. E Appendix E to Part 178—Flame Penetration Resistance Test (a) Criteria for Acceptance....

  5. 30 CFR 27.40 - Test to determine resistance to dust.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Test to determine resistance to dust. 27.40 Section 27.40 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING... determine resistance to dust. Components, subassemblies, or assemblies, the normal functioning of...

  6. RSRM top hat cover simulator lightning test, volume 2. Appendix A: Resistance measurements. Appendix B: Lightning test data plots

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Resistance measurements are given in graphical for when a simulated lightning discharge strikes on an exposed top hat cover simulator. The test sequence was to measure the electric and magnetic fields induced inside a redesigned solid rocket motor case.

  7. Preparation and Testing of Corrosion and Spallation-Resistant Coatings

    SciTech Connect

    Hurley, John

    2015-11-01

    This Energy & Environmental Research Center (EERC) project is designed to determine if plating APMT®, a specific highly oxidation-resistant oxide dispersion-strengthened FeCrAl alloy made by Kanthal, onto nickel-based superalloy turbine parts is a viable method for substantially improving the lifetimes and maximum use temperatures of the parts. The method for joining the APMT plate to the superalloys is called evaporative metal bonding and involves placing a thin foil of zinc between the plate and the superalloy, clamping them together, and heating in an atmosphere-controlled furnace. Upon heating, the zinc melts and dissolves the oxide skins of the alloys at the bond line, allowing the two alloys to diffuse into each other. The zinc then diffuses through the alloys and evaporates from their surfaces. During this annual reporting period, the finite element model was completed and used to design clamping jigs to hold the APMT plate to the larger blocks of superalloys during the bonding process. The clamping system was machined from titanium–zirconium–molybdenum and used to bond the APMT plate to the superalloy blocks. The bond between the APMT plate was weak for one of each of the superalloy blocks. We believe that this occurred because enough oxidation had occurred on the surface of the parts as a result of a 1-month time period between sandblasting to prepare the parts and the actual bonding process. The other blocks were, therefore, bonded within 1 day of preparing the parts for bonding, and their joints appear strong. Scanning electron microscopy analyses of representative joints showed that no zinc remained in the alloys after bonding. Also, phases rich in hafnium and tantalum had precipitated near the bond line in the APMT. Iron from the APMT had diffused into the superalloys during bonding, more extensively in the CM247LC than in the Rene 80. Nickel from the superalloys had diffused into the APMT, again more extensively in the joint with the CM247LC than

  8. PREPARATION AND TESTING OF CORROSIONAND SPALLATION-RESISTANT COATINGS

    SciTech Connect

    Hurley, John

    2014-11-01

    This Energy & Environmental Research Center (EERC) project is designed to determine if plating APMT®, a specific highly oxidation-resistant oxide dispersion-strengthened FeCrAl alloy made by Kanthal, onto nickel-based superalloy turbine parts is a viable method for substantially improving the lifetimes and maximum use temperatures of the parts. The method for joining the APMT plate to the superalloys is called evaporative metal bonding and involves placing a thin foil of zinc (Zn) between the plate and the superalloy, clamping them together, and heating in an atmosphere-controlled furnace. Upon heating, the Zn melts and dissolves the oxide skins of the alloys at the bond line, allowing the two alloys to diffuse into each other. The Zn then diffuses through the alloys and evaporates from their surfaces. Laboratory testing to determine the diffusion rate of Zn through the alloys has been completed. However, an analytical solution does not exist to model the diffusion of zinc through the alloys. For this reason, a finite difference algorithm using MATLAB was developed. It makes use of the hopscotch algorithm. The model allows the user to specify the dimensions of the metal parts, the Zn concentration at the bondline, the mesh size, time step, and Zn diffusivity. The experimentally measured values of diffusivity for Zn in APMT and Rene 80/CM 247LC are approximately 2.7 × 10-12 and 4 × 10-14 m2/s, respectively. While the qualitative behavior of the model appears correct, a comparison of the diffusion predictions with the experimental results from earlier in the project indicates that the expected Zn concentration is significantly higher than that measured experimentally. The difference depends on the assumed initial concentration, which is difficult to quantify exactly under experimental conditions for t = 0. In addition to the diffusion work, the coefficients of thermal expansions were determined for each of the alloys as a function of temperature. This information

  9. 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.

  10. Airflow energy harvesting with high wind velocities for industrial applications

    NASA Astrophysics Data System (ADS)

    Chew, Z. J.; Tuddenham, S. B.; Zhu, M.

    2016-11-01

    An airflow energy harvester capable of harvesting energy from vortices at high speed is presented in this paper. The airflow energy harvester is implemented using a modified helical Savonius turbine and an electromagnetic generator. A power management module with maximum power point finding capability is used to manage the harvested energy and convert the low voltage magnitude from the generator to a usable level for wireless sensors. The airflow energy harvester is characterized using vortex generated by air hitting a plate in a wind tunnel. By using an aircraft environment with wind speed of 17 m/s as case study, the output power of the airflow energy harvester is measured to be 126 mW. The overall efficiency of the power management module is 45.76 to 61.2%, with maximum power point tracking efficiency of 94.21 to 99.72% for wind speed of 10 to 18 m/s, and has a quiescent current of 790 nA for the maximum power point tracking circuit.

  11. 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…

  12. Single-stage electrohydraulic servosystem for actuating on airflow valve with frequencies to 500 hertz

    NASA Technical Reports Server (NTRS)

    Webb, J. A., Jr.; Mehmed, O.; Lorenzo, C. F.

    1980-01-01

    An airflow valve and its electrohydraulic actuation servosystem are described. The servosystem uses a high-power, single-stage servovalve to obtain a dynamic response beyond that of systems designed with conventional two-stage servovalves. The electrohydraulic servosystem is analyzed and the limitations imposed on system performance by such nonlinearities as signal saturations and power limitations are discussed. Descriptions of the mechanical design concepts and developmental considerations are included. Dynamic data, in the form of sweep-frequency test results, are presented and comparison with analytical results obtained with an analog computer model is made.

  13. Instrumentation and measurement of airflow and temperature in attics fitted with ridge and soffit vents

    SciTech Connect

    Romero, M.I.; Brenner, R.J.

    1998-12-31

    This study established a research facility where airflow velocities, temperature, and differential pressures could be measured at the ridge of an attic. Following the construction of a test building, sensors were constructed, calibrated, and installed inside the attic. Paired tests were performed for three different ridge vent treatments; two were rolled type vents and one was a baffled vent. When both attics were fitted with the same ridge vent, the airspeed and differential pressure profiles at the ridge were very similar for both attics, indicating that any observed differences in airspeed and differential pressure were caused by the ridge vent treatment used. The baffled vent and rolled vents were then installed on the ridge of the west and east attics, respectively. The data demonstrated that the baffled ridge vent provided a minimum of twice the ridge airspeed of the rolled vents, when all wind conditions were considered. On the day selected to study the direction of the airflows at the ridge, the baffled vent had airflow speeds at the ridge similar to the rolled vent without fabric backing. The baffled vent allowed air to come out of the attic through both sides of the ridge (negative differential pressures on both sides), while the rolled vent without fabric backing caused air to enter through the south side of the ridge and exit through the north side (positive differential pressure on the south side and negative differential pressure on the north), in effect short-circuiting the vent. The fabric-backed rolled vent allowed attic air to come out of the attic through both sides of the ridge, as did the baffled vent, but the airspeed was slower. The baffled vent was the one with the highest airspeed at the ridge and also had both sides of the vent under negative differential pressure, providing the most effective ventilation.

  14. Full-scale aircraft cabin flammability tests of improved fire-resistant materials

    NASA Technical Reports Server (NTRS)

    Stuckey, R. N.; Surpkis, D. E.; Price, L. J.

    1974-01-01

    Full-scale aircraft cabin flammability tests to evaluate the effectiveness of new fire-resistant materials by comparing their burning characteristics with those of older aircraft materials are described. Three tests were conducted and are detailed. Test 1, using pre-1968 materials, was run to correlate the procedures and to compare the results with previous tests by other organizations. Test 2 included newer, improved fire-resistant materials. Test 3 was essentially a duplicate of test 2, but a smokeless fuel was used. Test objectives, methods, materials, and results are presented and discussed. Results indicate that the pre-1968 materials ignited easily, allowed the fire to spread, produced large amounts of smoke and toxic combustion products, and resulted in a flash fire and major fire damage. The newer fire-resistant materials did not allow the fire to spread. Furthermore, they produced less, lower concentrations of toxic combustion products, and lower temperatures. The newer materials did not produce a flash fire.

  15. Evaluation and test of improved fire-resistant fluid lubricants for water reactor coolant pump motors. Volume 1. Fluid evaluation, bearing model tests, motor tests, and fire tests

    SciTech Connect

    Not Available

    1980-07-01

    Fires within nuclear containment have occurred when the lubricants used in reactor coolant pump motors have leaked or spilled onto the hot insulated main coolant piping. This project was directed toward determining the applicability of commercially available fire resistant fluid lubricants to the lubrication of the bearings of a reactor coolant pump motor. This report describes the evaluation of candidate fluids, the testing of these fluids, and the selection of a lubricant for use in a standard reactor coolant pump motor test. The test results indicated that the phosphate ester lubricants, when properly inhibited and maintained, are acceptable for use. Recommendations are presented for further work necessary to the successful application of the fire resistant fluid lubricant.

  16. Passenger vehicle tire rolling resistance can be predicted from a flat-belt test rig

    SciTech Connect

    Ivens, J.

    1989-01-01

    The rolling resistance of fifteen different types of tire was determined on-road by coastdown tests, using several vehicles variously fitted with 14 and 15 inch wheels. Corrections for tire pressure, and for external temperature, were deduced by data regression. The rolling resistance of the same tires was measured on a flat-belt tire test machine, and correction for tire pressure was determined in a like manner. In this paper, the results, in terms of the characteristic rolling resistance, are compared between rig and road. The various test procedures are discussed.

  17. Clinical implications of molecular drug resistance testing for Mycobacterium tuberculosis: a TBNET/RESIST-TB consensus statement.

    PubMed

    Domínguez, J; Boettger, E C; Cirillo, D; Cobelens, F; Eisenach, K D; Gagneux, S; Hillemann, D; Horsburgh, R; Molina-Moya, B; Niemann, S; Tortoli, E; Whitelaw, A; Lange, C

    2016-01-01

    The emergence of drug-resistant strains of Mycobacterium tuberculosis is a challenge to global tuberculosis (TB) control. Although culture-based methods have been regarded as the gold standard for drug susceptibility testing (DST), molecular methods provide rapid information on mutations in the M. tuberculosis genome associated with resistance to anti-tuberculosis drugs. We ascertained consensus on the use of the results of molecular DST for clinical treatment decisions in TB patients. This document has been developed by TBNET and RESIST-TB groups to reach a consensus about reporting standards in the clinical use of molecular DST results. Review of the available literature and the search for evidence included hand-searching journals and searching electronic databases. The panel identified single nucleotide mutations in genomic regions of M. tuberculosis coding for katG, inhA, rpoB, embB, rrs, rpsL and gyrA that are likely related to drug resistance in vivo. Identification of any of these mutations in clinical isolates of M. tuberculosis has implications for the management of TB patients, pending the results of in vitro DST. However, false-positive and false-negative results in detecting resistance-associated mutations in drugs for which there is poor or unproven correlation between phenotypic and clinical drug resistance complicate the interpretation. Reports of molecular DST results should therefore include specific information on the mutations identified and provide guidance for clinicians on interpretation and on the choice of the appropriate initial drug regimen.

  18. HemaSpot, a Novel Blood Storage Device for HIV-1 Drug Resistance Testing.

    PubMed

    Brooks, K; DeLong, A; Balamane, M; Schreier, L; Orido, M; Chepkenja, M; Kemboi, E; D'Antuono, M; Chan, P A; Emonyi, W; Diero, L; Coetzer, M; Kantor, R

    2016-01-01

    HemaSpot, a novel dried-blood storage filter device, was used for HIV-1 pol resistance testing in 30 fresh United States blood samples and 54 previously frozen Kenyan blood samples. Genotyping succeeded in 79% and 58% of samples, respectively, improved with shorter storage and higher viral load, and had good (86%) resistance mutation concordance to plasma.

  19. Electrical test methods for on-line fuel cell ohmic resistance measurement

    NASA Astrophysics Data System (ADS)

    Cooper, K. R.; Smith, M.

    The principles and trade-offs of four electrical test methods suitable for on-line measurement of the ohmic resistance (R Ω) of fuel cells is presented: current interrupt, AC resistance, high frequency resistance (HFR), and electrochemical impedance spectroscopy (EIS). The internal resistance of a proton exchange membrane (PEM) fuel cell determined with the current interrupt, HFR and EIS techniques is compared. The influence of the AC amplitude and frequency of the HFR measurement on the observed ohmic resistance is examined, as is the ohmic resistance extracted from the EIS data by modeling the spectra with a transmission line model for porous electrodes. The ohmic resistance of a H 2/O 2 PEM fuel cell determined via the three methods was within 10-30% of each other. The current interrupt technique consistently produced measured cell resistances that exceeded those of the other two techniques. For the HFR technique, the frequency at which the measurement was conducted influenced the measured resistance (i.e., higher frequency providing smaller R Ω), whereas the AC amplitude did not effect the observed value. The difference in measured ohmic resistance between these techniques exceeds that reasonably accounted for by measurement error. The source of the discrepancy between current interrupt and impedance-based methods is attributed to the difference in the response of a non-uniformly polarized electrode, such as a porous electrode with non-negligible ohmic resistance, to a large perturbation (current interrupt event) as compared to a small perturbation (impedance measurement).

  20. Large eddy simulation of the pharyngeal airflow associated with obstructive sleep apnea syndrome at pre and post-surgical treatment.

    PubMed

    Mihaescu, Mihai; Mylavarapu, Goutham; Gutmark, Ephraim J; Powell, Nelson B

    2011-08-11

    Obstructive Sleep Apnea Syndrome (OSAS) is the most common sleep-disordered breathing medical condition and a potentially life-threatening affliction. Not all the surgical or non-surgical OSAS therapies are successful for each patient, also in part because the primary factors involved in the etiology of this disorder are not completely understood. Thus, there is a need for improving both diagnostic and treatment modalities associated with OSAS. A verified and validated (in terms of mean velocity and pressure fields) Large Eddy Simulation approach is used to characterize the abnormal pharyngeal airflow associated with severe OSAS and its interaction with the airway wall in a subject who underwent surgical treatment. The analysis of the unsteady flow at pre- and post-treatment is used to illustrate the airflow dynamics in the airway associated with OSAS and to reveal as well, the changes in the flow variables after the treatment. At pre-treatment, large airflow velocity and wall shear stress values were found at the obstruction site in all cases. Downstream of obstruction, flow separation generated flow recirculation regions and enhanced the turbulence production in the jet-like shear layers. The interaction between the generated vortical structures and the pharyngeal airway wall induced large fluctuations in the pressure forces acting on the pharyngeal wall. After the surgery, the flow field instabilities vanished and both airway resistance and wall shear stress values were significantly reduced.

  1. Mycobacterium tuberculosis drug-resistance testing: challenges, recent developments and perspectives.

    PubMed

    Schön, T; Miotto, P; Köser, C U; Viveiros, M; Böttger, E; Cambau, E

    2017-03-01

    Drug-resistance testing, or antimicrobial susceptibility testing (AST), is mandatory for Mycobacterium tuberculosis in cases of failure on standard therapy. We reviewed the different methods and techniques of phenotypic and genotypic approaches. Although multiresistant and extensively drug-resistant (MDR/XDR) tuberculosis is present worldwide, AST for M. tuberculosis (AST-MTB) is still mainly performed according to the resources available rather than the drug-resistance rates. Phenotypic methods, i.e. culture-based AST, are commonly used in high-income countries to confirm susceptibility of new cases of tuberculosis. They are also used to detect resistance in tuberculosis cases with risk factors, in combination with genotypic tests. In low-income countries, genotypic methods screening hot-spot mutations known to confer resistance were found to be easier to perform because they avoid the culture and biosafety constraint. Given that genotypic tests can rapidly detect the prominent mechanisms of resistance, such as the rpoB mutation for rifampicin resistance, we are facing new challenges with the observation of false-resistance (mutations not conferring resistance) and false-susceptibility (mutations different from the common mechanism) results. Phenotypic and genotypic approaches are therefore complementary for obtaining a high sensitivity and specificity for detecting drug resistances and susceptibilities to accurately predict MDR/XDR cure and to gather relevant data for resistance surveillance. Although AST-MTB was established in the 1960s, there is no consensus reference method for MIC determination against which the numerous AST-MTB techniques can be compared. This information is necessary for assessing in vitro activity and setting breakpoints for future anti-tuberculosis agents.

  2. 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.

  3. 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.

  4. Design and Testing of an Erosion Resistant Ultrasonic De-Icing System for Rotorcraft Blades

    DTIC Science & Technology

    2013-08-01

    water pressure sent to the nozzles controls the MVD. Figure 73: AERTS photograph with de-icing blades SO 4.3.2. Ultrasonic Driving There are...Applied Research Laboratory Technical Report Design and Testing of an Erosion Resistant Ultrasonic De-Icing System for Rotorcraft Blades by...University The Applied Research Laboratory P.O. Box 30 State College, PA 16804 Design and Testing of an Erosion Resistant Ultrasonic De-Icing System

  5. Fire Resistance Testing of Bulkhead and Deck Penetrations. Phase 2

    DTIC Science & Technology

    1988-12-01

    thick steel plate. All sample 12 construction was representative of Class A-0 construction. The UL staff secured insulation ( rockwool batts) to the...designated side of the steel plates and penetrants for testing as Class A-60 deck assemblies. The rockwool batts complied with the Class A-60...insulated with rockwool batts and tested for a Class A-60 rating. This group consisted of one steel penetration, eight copper penetrations, four PVC

  6. 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.

  7. Testing Resistance: Busno-Cratic Power, Standardized Tests, and Care of the Self

    ERIC Educational Resources Information Center

    Mayo, Cris

    2005-01-01

    I will argue in what follows, following the insights of James Marshall on busno-cratic power, that resistance to this new power is already well underway, and that this resistance is potentially problematic and potentially transgressive (in Marshall's words "a reflective reconstitution"). The self is not only a chooser in busno-cratic land, it is…

  8. Cosmic ray tests of large area Multigap Resistive Plate Chambers

    NASA Astrophysics Data System (ADS)

    An, Shaohui; Hatzifotiadou, D.; Kim, Jinsook; Williams, M. C. S.; Zichichi, A.; Zuyeuski, R.

    2007-07-01

    We have built Multigap Resistive Plate Chambers (MRPC) with six 300 μm gas gaps and an active area of 158×82 cm2. The signals are generated on 2.5 cm wide copper pickup strips; these are read out at each end thus allowing the position of the hit along the strip to be obtained from the time difference. Using three of these chambers we have set up a cosmic tracking system in a similar manner as planned for the Extreme Energy Events (EEE) project. The details of the set-up are presented in this paper. In addition we discuss the time and position resolution of these MRPCs measured using cosmic rays.

  9. KSC lubricant testing program. [lubrication characteristics and corrosion resistance

    NASA Technical Reports Server (NTRS)

    Lockhart, B. J.; Bryan, C. J.

    1973-01-01

    A program was conducted to evaluate the performance of various lubricants in use and considered for use at Kennedy Space Center (KSC). The overall objectives of the program were to: (1) determine the lubrication characteristics and relative corrosion resistance of lubricants in use and proposed for use at KSC; (2) identify materials which may be equivalent to or better than KELF-90 and Krytox 240 AC greases; and (3) identify or develop an improved lubricating oil suitable for use in liquid oxygen (LOX) pumps at KSC. It was concluded that: (1) earth gel thickened greases are very poor corrosion preventive materials in the KSC environment; (2) Halocarbon 25-5S and Braycote 656 were suitable substiutes for KELF-90 and Krytox 240 AC respectively; and (3) none of the oils evaluated possessed the necessary inertness, lubricity, and corrosion prevention characteristics for the KSC LOX pumping systems in their present configuration.

  10. A test of taxonomic predictivity: resistance to early blight in wild relatives of cultivated potato.

    PubMed

    Jansky, S H; Simon, R; Spooner, D M

    2008-06-01

    Host plant resistance offers an attractive method of control for early blight (caused by the foliar fungus Alternaria solani), a widespread disease that appears annually in potato crops worldwide. We tested the assumed ability of taxonomy to predict the presence of early blight resistance genes in wild Solanum species for which resistance was observed in related species. We also tested associations to ploidy, crossing group, breeding system, and geography. As in a prior study of Sclerotinia sclerotiorum (white mold) resistance, tremendous variation for resistance to early blight was found to occur within and among species. There was no discernable relationship between the distribution of resistant phenotypes and taxonomic series (based on an intuitive interpretation of morphological data), clade (based on a cladistic analysis of plastid DNA data), ploidy, breeding system, geographic distance, or climate parameters. Species and individual accessions with high proportions of early blight resistant plants were identified, but high levels of inter- and intra-accession variability were observed. Consequently, the designation of species or accessions as resistant or susceptible must take this variation into account. This study calls into question the assumption that taxonomic or geographic data can be used to predict sources of early blight resistance in wild Solanum species.

  11. Antimicrobial susceptibility testing for Helicobacter pylori in times of increasing antibiotic resistance.

    PubMed

    Smith, Sinéad M; O'Morain, Colm; McNamara, Deirdre

    2014-08-07

    The gram-negative bacterium Helicobacter pylori (H. pylori) causes chronic gastritis, gastric and duodenal ulcers, gastric cancer and mucosa-associated lymphoid tissue lymphoma. Treatment is recommended in all symptomatic patients. The current treatment options for H. pylori infection are outlined in this review in light of the recent challenges in eradication success, largely due to the rapid emergence of antibiotic resistant strains of H. pylori. Antibiotic resistance is a constantly evolving process and numerous studies have shown that the prevalence of H. pylori antibiotic resistance varies significantly from country to country, and even between regions within the same country. In addition, recent data has shown that previous antibiotic use is associated with harbouring antibiotic resistant H. pylori. Local surveillance of antibiotic resistance is warranted to guide clinicians in their choice of therapy. Antimicrobial resistance is assessed by H. pylori culture and antimicrobial susceptibility testing. Recently developed molecular tests offer an attractive alternative to culture and allow for the rapid molecular genetic identification of H. pylori and resistance-associated mutations directly from biopsy samples or bacterial culture material. Accumulating evidence indicates that surveillance of antimicrobial resistance by susceptibility testing is feasible and necessary to inform clinicians in their choice of therapy for management of H. pylori infection.

  12. 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.

  13. 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.

  14. Molecular and biological diagnostic tests for monitoring benzimidazole resistance in human soil-transmitted helminths.

    PubMed

    Diawara, Aïssatou; Schwenkenbecher, Jan M; Kaplan, Ray M; Prichard, Roger K

    2013-06-01

    In endemic countries with soil-transmitted helminths mass drug administration with albendazole or mebendazole are being implemented as a control strategy. However, it is well known in veterinary helminths that the use of the same benzimidazole drugs can place selection on the β-tubulin gene, leading to resistance. Given the concern that resistance could arise in human soil-transmitted helminths, there is an urgent need to develop accurate diagnostic tools for monitoring resistance. In this study, we developed molecular assays to detect putative resistance genetic changes in Ascaris lumbricoides, Trichuris trichiura, and hookworms, and we optimized an egg hatch assay for the canine hookworm Ancylostoma caninum and applied it to Necator americanus. Both assays were tested on field samples. The molecular assays demonstrated their reproducibility and capacity to detect the presence of worms carrying putative resistance-associated genetic changes. However, further investigations are needed to validate our molecular and biological tests on additional field isolates.

  15. Predictive Value of Molecular Drug Resistance Testing of Mycobacterium tuberculosis Isolates in Valle del Cauca, Colombia

    PubMed Central

    García, Pamela K.; Nieto, Luisa Maria; van Soolingen, Dick

    2013-01-01

    Previous evaluations of the molecular GenoType tests have promoted their use to detect resistance to first- and second-line antituberculosis drugs in different geographical regions. However, there are known geographic variations in the mutations associated with drug resistance in Mycobacterium tuberculosis, and especially in South America, there is a paucity of information regarding the frequencies and types of mutations associated with resistance to first- and second-line antituberculosis drugs. We therefore evaluated the performance of the GenoType kits in this region by testing 228 M. tuberculosis isolates in Colombia, including 134 resistant and 94 pansusceptible strains. Overall, the sensitivity and specificity of the GenoType MTBDRplus test ranged from 92 to 96% and 97 to 100%, respectively; the agreement index was optimal (Cohen's kappa, >0.8). The sensitivity of the GenoType MTBDRsl test ranged from 84 to 100% and the specificity from 88 to 100%. The most common mutations were katG S315T1, rpoB S531L, embB M306V, gyrA D94G, and rrs A1401G. Our results reflect the utility of the GenoType tests in Colombia; however, as some discordance still exists between the conventional and molecular approaches in resistance testing, we adhere to the recommendation that the GenoType tests serve as early guides for therapy, followed by phenotypic drug susceptibility testing for all cases. PMID:23658272

  16. Evaluation of multidrug resistant phenotype by flow cytometry with monoclonal antibodies and functional tests.

    PubMed

    Lizard, G; Maynadié, M; Roignot, P; Lizard-Nacol, S; Poupon, M F

    1995-03-01

    Multidrug resistant (MDR) phenotype is characterized by a defect in drug accumulation caused by overexpression of a transmembrane glycoprotein, the P-glycoprotein (P-gp). MDR phenotype can be characterized either with monoclonal antibodies raised against P-gp or with functional tests, most often based on the incorporation of fluorescent compounds. In the present study, data obtained with the monoclonal antibodies C219, JSB1 and MRK16 are compared to those of functional tests performed by flow cytometry including uptake of daunorubicin (DNR), Rhodamine 123 (Rh 123) or Hoechst 33342. Sensitive and resistant cell lines K562S, K562R, KBA1 and KB31, derived either from a human chronic myeloid leukemia or from a human epithelial carcinoma, were used. In resistant cells, P-gp expression was revealed with either the monoclonal antibodies C219, JSB1 or MRK-16. The most specific results were obtained with MRK-16. With functional tests, no matter which dyes were used, the fluorescence was always stronger in sensitive than in resistant cells. However, with DNR and Hoechst 33342, an incorporation of these dyes was exhibited in resistant cells. This phenomenon was not observed with Rh 123, which makes it possible to distinguish clearly between sensitive and resistant cells and to detect as few as 1% of resistant cells. Because of its high sensitivity, the functional test involving incorporation of Rh 123 was successfully used in acute myeloid leukemia to detect multichemoresistant cells.

  17. ESBL Detection: Comparison of a Commercially Available Chromogenic Test for Third Generation Cephalosporine Resistance and Automated Susceptibility Testing in Enterobactericeae

    PubMed Central

    El-Jade, Mohamed Ramadan; Parcina, Marijo; Schmithausen, Ricarda Maria; Stein, Christoph; Meilaender, Alina; Hoerauf, Achim; Molitor, Ernst

    2016-01-01

    Rapid detection and reporting of third generation cephalosporine resistance (3GC-R) and of extended spectrum betalactamases in Enterobacteriaceae (ESBL-E) is a diagnostic and therapeutic priority to avoid inefficacy of the initial antibiotic regimen. In this study we evaluated a commercially available chromogenic screen for 3GC-R as a predictive and/or confirmatory test for ESBL and AmpC activity in clinical and veterinary Enterobacteriaceae isolates. The test was highly reliable in the prediction of cefotaxime and cefpodoxime resistance, but there was no correlation with ceftazidime and piperacillin/tazobactam minimal inhibitory concentrations. All human and porcine ESBL-E tested were detected with exception of one genetically positive but phenotypically negative isolate. By contrast, AmpC detection rates lay below 30%. Notably, exclusion of piperacillin/tazobactam resistant, 3GC susceptible K1+ Klebsiella isolates increased the sensitivity and specificity of the test for ESBL detection. Our data further imply that in regions with low prevalence of AmpC and K1 positive E. coli strains chromogenic testing for 3GC-R can substitute for more time consuming ESBL confirmative testing in E. coli isolates tested positive by Phoenix or VITEK2 ESBL screen. We, therefore, suggest a diagnostic algorithm that distinguishes 3GC-R screening from primary culture and species-dependent confirmatory ESBL testing by βLACTATM and discuss the implications of MIC distribution results on the choice of antibiotic regimen. PMID:27494134

  18. ESBL Detection: Comparison of a Commercially Available Chromogenic Test for Third Generation Cephalosporine Resistance and Automated Susceptibility Testing in Enterobactericeae.

    PubMed

    El-Jade, Mohamed Ramadan; Parcina, Marijo; Schmithausen, Ricarda Maria; Stein, Christoph; Meilaender, Alina; Hoerauf, Achim; Molitor, Ernst; Bekeredjian-Ding, Isabelle

    2016-01-01

    Rapid detection and reporting of third generation cephalosporine resistance (3GC-R) and of extended spectrum betalactamases in Enterobacteriaceae (ESBL-E) is a diagnostic and therapeutic priority to avoid inefficacy of the initial antibiotic regimen. In this study we evaluated a commercially available chromogenic screen for 3GC-R as a predictive and/or confirmatory test for ESBL and AmpC activity in clinical and veterinary Enterobacteriaceae isolates. The test was highly reliable in the prediction of cefotaxime and cefpodoxime resistance, but there was no correlation with ceftazidime and piperacillin/tazobactam minimal inhibitory concentrations. All human and porcine ESBL-E tested were detected with exception of one genetically positive but phenotypically negative isolate. By contrast, AmpC detection rates lay below 30%. Notably, exclusion of piperacillin/tazobactam resistant, 3GC susceptible K1+ Klebsiella isolates increased the sensitivity and specificity of the test for ESBL detection. Our data further imply that in regions with low prevalence of AmpC and K1 positive E. coli strains chromogenic testing for 3GC-R can substitute for more time consuming ESBL confirmative testing in E. coli isolates tested positive by Phoenix or VITEK2 ESBL screen. We, therefore, suggest a diagnostic algorithm that distinguishes 3GC-R screening from primary culture and species-dependent confirmatory ESBL testing by βLACTATM and discuss the implications of MIC distribution results on the choice of antibiotic regimen.

  19. One Teacher's Resistance to the Pressures of Test Mentality

    ERIC Educational Resources Information Center

    Dooley, Caitlin McMunn

    2005-01-01

    The strategies adopted and the efforts taken by Jacqueline, who is a teacher, to combat the pressures of testing and at the same time develop the love of literature amongst her students, is described. Jacqueline develops and practices her own beliefs regarding the methods for learning literature, which she has gained from her experience, reading…

  20. Rapid Aminoglycoside NP Test for Rapid Detection of Multiple Aminoglycoside Resistance in Enterobacteriaceae.

    PubMed

    Nordmann, Patrice; Jayol, Aurélie; Dobias, Jan; Poirel, Laurent

    2017-04-01

    The rapid aminoglycoside NP (Nordmann/Poirel) test was developed to rapidly identify multiple aminoglycoside (AG) resistance in Enterobacteriaceae It is based on the detection of the glucose metabolism related to enterobacterial growth in the presence of a defined concentration of amikacin plus gentamicin. Formation of acid metabolites was evidenced by a color change (orange to yellow) of the red phenol pH indicator. The rapid aminoglycoside NP test was evaluated by using bacterial colonies of 18 AG-resistant isolates producing 16S rRNA methylases, 20 AG-resistant isolates expressing AG-modifying enzymes (acetyl-, adenyl-, and phosphotransferases), and 10 isolates susceptible to AG. Its sensitivity and specificity were 100% and 97%, respectively, compared to the broth dilution method, which was taken as the gold standard for determining aminoglycoside resistance. The test is inexpensive, rapid (<2 h), and implementable worldwide.

  1. An alternative to the Drop Ball Test for the measurement of ophthalmic glass fracture resistance.

    PubMed

    Scaief, A L

    1975-11-01

    The Drop Ball Test (DBT) has some distinct disadvantages both as a standard measurement for ophthalmic lens fracture resistance and as a research tool. The Static Test (ST) was devised to allow a load and enzrgy analysis of the DBT and enable more rapid and accurate testing of large ophthalmic lens samples. It was found that over 50% of the energy generated in the DBT is absorbed by the lens mount instead of the test lens. This means that the standard DBT height of 50 inches is more an indication of DBT components than lens fracture resistance. Static testing of non-tempered, heat tempered and chemically tempered lenses correlated well with former DBT studies. The ST, however, allowed lens fracture resistance to be represented in pounds-load, a value better understood practically and mathematically.

  2. Effect of airflow and material models on tissue displacement for surgical planning of pharyngeal airways in pediatric down syndrome patients.

    PubMed

    Subramaniam, Dhananjay Radhakrishnan; Mylavarapu, Goutham; Fleck, Robert J; Amin, Raouf S; Shott, Sally R; Gutmark, Ephraim J

    2017-03-08

    Pharyngeal narrowing in obstructive sleep apnea (OSA) results from flow-induced displacement of soft tissue. The objective of this study is to evaluate the effect of airflow parameters and material model on soft tissue displacement for planning surgical treatment in pediatric patients with OSA and Down syndrome (DS). Anatomically accurate, three-dimensional geometries of the pharynx and supporting tissue were reconstructed for one pediatric OSA patient with DS using magnetic resonance images. Six millimeters of adenoid tissue was virtually removed based on recommendations from the surgeon, to replicate the actual adenoidectomy. Computational simulations of flow-induced obstruction of the pharynx during inspiration were performed using patient-specific values of tissue elasticity for pre and post-operative airways. Sensitivity of tissue displacement to selection of turbulence model, variation in inspiratory airflow, nasal airway resistance and choice of non-linear material model was evaluated. The displacement was less sensitive to selection of turbulence model (10% difference) and more sensitive to airflow rate (20% difference) and nasal resistance (30% difference). The sensitivity analysis indicated that selection of Neo-Hookean, Yeoh, Mooney-Rivlin or Gent models would result in identical tissue displacements (less than 1% difference) for the same flow conditions. Change in pharyngeal airway resistance between the rigid and collapsible models was nearly twice for the pre-operative case as compared to the post-operative scenario. The tissue strain at the site of obstruction in the velopharyngeal airway was lowered by approximately 84% following surgery. Inclusion of tissue elasticity resulted in better agreement with the actual surgical outcome compared to a rigid wall assumption, thereby emphasizing the importance of pharyngeal compliance for guiding treatment in pediatric OSA patients.

  3. [In vitro testing of yeast resistance to antimycotic substances].

    PubMed

    Potel, J; Arndt, K

    1982-01-01

    Investigations have been carried out in order to clarify the antibiotic susceptibility determination of yeasts. 291 yeast strains of different species were tested for sensitivity to 7 antimycotics: amphotericin B, flucytosin, nystatin, pimaricin, clotrimazol, econazol and miconazol. Additionally to the evaluation of inhibition zone diameters and MIC-values the influence of pH was examined. 1. The dependence of inhibition zone diameters upon pH-values varies due to the antimycotic tested. For standardizing purposes the pH 6.0 is proposed; moreover, further experimental parameters, such as nutrient composition, agar depth, cell density, incubation time and -temperature, have to be normed. 2. The relation between inhibition zone size and logarythmic MIC does not fit a linear regression analysis when all species are considered together. Therefore regression functions have to be calculated selecting the individual species. In case of the antimycotics amphotericin B, nystatin and pimaricin the low scattering of the MIC-values does not allow regression analysis. 3. A quantitative susceptibility determination of yeasts--particularly to the fungistatical substances with systemic applicability, flucytosin and miconazol, -- is advocated by the results of the MIC-tests.

  4. Large-scale, spatially-explicit test of the refuge strategy for delaying insecticide resistance

    PubMed Central

    Carrière, Yves; Ellers-Kirk, Christa; Hartfield, Kyle; Larocque, Guillaume; Degain, Ben; Dutilleul, Pierre; Dennehy, Timothy J.; Marsh, Stuart E.; Crowder, David W.; Li, Xianchun; Ellsworth, Peter C.; Naranjo, Steven E.; Palumbo, John C.; Fournier, Al; Antilla, Larry; Tabashnik, Bruce E.

    2012-01-01

    The refuge strategy is used worldwide to delay the evolution of pest resistance to insecticides that are either sprayed or produced by transgenic Bacillus thuringiensis (Bt) crops. This strategy is based on the idea that refuges of host plants where pests are not exposed to an insecticide promote survival of susceptible pests. Despite widespread adoption of this approach, large-scale tests of the refuge strategy have been problematic. Here we tested the refuge strategy with 8 y of data on refuges and resistance to the insecticide pyriproxyfen in 84 populations of the sweetpotato whitefly (Bemisia tabaci) from cotton fields in central Arizona. We found that spatial variation in resistance to pyriproxyfen within each year was not affected by refuges of melons or alfalfa near cotton fields. However, resistance was negatively associated with the area of cotton refuges and positively associated with the area of cotton treated with pyriproxyfen. A statistical model based on the first 4 y of data, incorporating the spatial distribution of cotton treated and not treated with pyriproxyfen, adequately predicted the spatial variation in resistance observed in the last 4 y of the study, confirming that cotton refuges delayed resistance and treated cotton fields accelerated resistance. By providing a systematic assessment of the effectiveness of refuges and the scale of their effects, the spatially explicit approach applied here could be useful for testing and improving the refuge strategy in other crop–pest systems. PMID:22215605

  5. Preparation of CNTs rope by electrostatic and airflow field carding with high speed rotor spinning

    NASA Astrophysics Data System (ADS)

    Dai, J. F.; Liu, J. F.; Zou, J. T.; Dai, Y. L.

    2015-12-01

    The large-scale preparation of disorderly CNTs with a length larger than 3 mm using CVD method were aligned in polymer monomer airflow fields in a quartz tube with an internal diameter of 200 μm and a length of 1.5 m. The airflow aligned CNTs at the output end of the pipe connects to a copper nozzle with an electrostatic field of applied voltage 5x105 V/m and space length of 0.03 m, which were further realigned using via electrostatic spinning. End to end spray into the high speed rotor twisted single-stranded carbon nanotubes threads via rotor spinning technology. The essential component of this technique was the use of carbon nanotubes at a high rotory speed (200000 r/min) combined with the double twisting of filaments that were twisted together to increase the radial friction of the entire section. SEM micrography showed that carbon nanotube thread has a uniform diameter of approximately 200 μm. Its tensile strength was tested up to 2.7 Gpa, with a length of several meters.

  6. Evaluation of an experimental short-length annular combustor: One-side-entry dilution airflow concept

    NASA Technical Reports Server (NTRS)

    Humenik, F. M.; Biaglow, J. A.

    1973-01-01

    A test program was conducted to evaluate an experimental short-length annular combustor that uses a one-side-entry dilution airflow concept. The combustor design features scoops on the outer liner for controlling the primary- and secondary-zone airflow distribution. Combustor inlet total pressures were limited to 62 N/sq cm (90 psia) with inlet-air temperatures from 590 K (600 F) to 890 K (1150 F). At a diffuser inlet Mach number of 0.25, the exit temperature pattern factor was 0.44 with an average exit temperature of 1436 K (2124 F) and a total pressure loss of 4.3 percent. At a diffuser inlet Mach number of 0.31, the exit temperature pattern factor was reduced to 0.29 with an average exit temperature of 1450 K (2151 F) and a total pressure loss of 6.1 percent. Nominal combustion efficiencies of 100 percent were obtained with the ASTM A-1 fuel. Exhaust gas emissions, smoke, and altitude relight data are included with exit-temperature profiles and distribution patterns.

  7. Breathing life into dinosaurs: tackling challenges of soft-tissue restoration and nasal airflow in extinct species.

    PubMed

    Bourke, Jason M; Porter, W M Ruger; Ridgely, Ryan C; Lyson, Tyler R; Schachner, Emma R; Bell, Phil R; Witmer, Lawrence M

    2014-11-01

    The nasal region plays a key role in sensory, thermal, and respiratory physiology, but exploring its evolution is hampered by a lack of preservation of soft-tissue structures in extinct vertebrates. As a test case, we investigated members of the "bony-headed" ornithischian dinosaur clade Pachycephalosauridae (particularly Stegoceras validum) because of their small body size (which mitigated allometric concerns) and their tendency to preserve nasal soft tissues within their hypermineralized skulls. Hypermineralization directly preserved portions of the olfactory turbinates along with an internal nasal ridge that we regard as potentially an osteological correlate for respiratory conchae. Fossil specimens were CT-scanned, and nasal cavities were segmented and restored. Soft-tissue reconstruction of the nasal capsule was functionally tested in a virtual environment using computational fluid dynamics by running air through multiple models differing in nasal soft-tissue conformation: a bony-bounded model (i.e., skull without soft tissue) and then models with soft tissues added, such as a paranasal septum, a scrolled concha, a branched concha, and a model combining the paranasal septum with a concha. Deviations in fluid flow in comparison to a phylogenetically constrained sample of extant diapsids were used as indicators of missing soft tissue. Models that restored aspects of airflow found in extant diapsids, such as appreciable airflow in the olfactory chamber, were judged as more likely. The model with a branched concha produced airflow patterns closest to those of extant diapsids. These results from both paleontological observation and airflow modeling indicate that S. validum and other pachycephalosaurids could have had both olfactory and respiratory conchae. Although respiratory conchae have been linked to endothermy, such conclusions require caution in that our re-evaluation of the reptilian nasal apparatus indicates that respiratory conchae may be more widespread

  8. New Screening Test Developed for the Blanching Resistance of Copper Alloys

    NASA Technical Reports Server (NTRS)

    Thomas-Ogbuji, Linus U.

    2004-01-01

    NASA's extensive efforts towards more efficient, safer, and more affordable space transportation include the development of new thrust-cell liner materials with improved capabilities and longer lives. For rocket engines fueled with liquid hydrogen, an important metric of liner performance is resistance to blanching, a phenomenon of localized wastage by cycles of oxidation-reduction due to local imbalance in the oxygen-fuel ratio. The current liner of the Space Shuttle Main Engine combustion chamber, a Cu-3Ag-0.5Zr alloy (NARloy-Z) is degraded in service by blanching. Heretofore, evaluating a liner material for blanching resistance involved elaborate and expensive hot-fire tests performed on rocket test stands. To simplify that evaluation, researchers at the NASA Glenn Research Center developed a screening test that uses simple, in situ oxidation-reduction cycling in a thermogravimetric analyzer (TGA). The principle behind this test is that resistance to oxidation or to the reduction of oxide, or both, implies resistance to blanching. Using this test as a preliminary tool to screen alloys for blanching resistance can improve reliability and save time and money. In this test a small polished coupon is hung in a TGA furnace at the desired (service) temperature. Oxidizing and reducing gases are introduced cyclically, in programmed amounts. Cycle durations are chosen by calibration, such that all copper oxides formed by oxidation are fully reduced in the next reduction interval. The sample weight is continuously acquired by the TGA as usual.

  9. Numerical Analysis of the Resistance to Shear Test of Clinched Assemblies of Thin Metal Sheets

    SciTech Connect

    Jomaa, Moez; Billardon, Rene

    2007-05-17

    The work presented in this paper is part of a more extensive study the aim of which is to build a complete simulation of the clinching process and subsequent resistance tests. This paper focuses on finite element analyses - that are performed with the ABAQUS code - of the resistance of clinched points to shear test. These analyses are run up to propagation of metal sheet fracture. A simplified procedure is proposed to identify the fracture initiation and propagation models that are used to simulate this failure process. This identification process is based on Lemaitre's ductile damage model. The numerical simulations of a shear test have been compared to experimental results.

  10. Specific Resistance. Operational Control Tests for Wastewater Facilities. Instructor's Manual [and] Student Workbook.

    ERIC Educational Resources Information Center

    Wooley, John F.

    A commonly used test for determining filterability of conditioned sludge is the specific resistance (Buchner funnel) test. The sludge is filtered through filter paper using a Buchner funnel, and the time needed to obtain a given volume of filtrate (or for cake residue to begin to crack) is measured. The shorter the time, the better the…

  11. Evaluation of wheelchair tire rolling resistance using dynamometer-based coast-down tests.

    PubMed

    Kwarciak, Andrew M; Yarossi, Mathew; Ramanujam, Arvind; Dyson-Hudson, Trevor A; Sisto, Sue Ann

    2009-01-01

    The objective of this study was to compare the rolling resistance of four common manual wheelchair tires (two pneumatic and two airless solid) and the solid tires used on a commercially available force- and moment-sensing wheel. Coast-down tests were performed with a wheelchair positioned on a two-drum dynamometer. Within each of three load conditions, tire type had a significant effect on rolling resistance (p < 0.001). The pneumatic tires had smaller rolling resistances and were less affected by load increases than the solid tires. Within the two tire types, higher air pressure or firmness and lower profile tread corresponded to less rolling resistance. Wheelchair users, clinicians, and researchers must consider the effect of tire type on wheelchair rolling resistance when selecting a manual wheelchair tire.

  12. Materials screening chamber for testing materials resistance to atomic oxygen

    NASA Technical Reports Server (NTRS)

    Pippin, H. G.; Carruth, Ralph

    1989-01-01

    A unique test chamber for exposing material to a known flux of oxygen atoms is described. The capabilities and operating parameters of the apparatus include production of an oxygen atom flux in excess of 5 x 10 to the 16th atoms/sq cm-sec, controlled heating of the sample specimen, RF circuitry to contain the plasma within a small volume, and long exposure times. Flux measurement capabilities include a calorimetric probe and a light titration system. Accuracy and limitations of these techniques are discussed. An extension to the main chamber to allow simultaneous ultraviolet and atomic oxygen exposure is discussed. The oxygen atoms produced are at thermal energies. Sample specimens are maintained at any selected temperature between ambient and 200 C, to within + or - 2 C. A representative example of measurements made using the chamber is presented.

  13. Testing Taxonomic Predictivity of Foliar and Tuber Resistance to Phytophthora infestans in Wild Relatives of Potato.

    PubMed

    Khiutti, A; Spooner, D M; Jansky, S H; Halterman, D A

    2015-09-01

    Potato late blight, caused by the oomycete phytopathogen Phytophthora infestans, is a devastating disease found in potato-growing regions worldwide. Long-term management strategies to control late blight include the incorporation of host resistance to predominant strains. However, due to rapid genetic changes within pathogen populations, rapid and recurring identification and integration of novel host resistance traits is necessary. Wild relatives of potato offer a rich source of desirable traits, including late blight resistance, but screening methods can be time intensive. We tested the ability of taxonomy, ploidy, crossing group, breeding system, and geography to predict the presence of foliar and tuber late blight resistance in wild Solanum spp. Significant variation for resistance to both tuber and foliar late blight was found within and among species but there was no discernable predictive power based on taxonomic series, clade, ploidy, breeding system, elevation, or geographic location. We observed a moderate but significant correlation between tuber and foliar resistance within species. Although previously uncharacterized sources of both foliar and tuber resistance were identified, our study does not support an assumption that taxonomic or geographic data can be used to predict sources of late blight resistance in wild Solanum spp.

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

    PubMed Central

    Morgan, K T; Monticello, T M

    1990-01-01

    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. Images FIGURE 4. FIGURE 6. FIGURE 7. PMID:2200663

  15. 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.

  16. Integrative pathway genomics of lung function and airflow obstruction

    PubMed Central

    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.

    2015-01-01

    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

  17. Contamination control in HVAC systems for aseptic processing area. Part I: Case study of the airflow velocity in a unidirectional airflow workstation with computational fluid dynamics.

    PubMed

    Ogawa, M

    2000-01-01

    A unidirectional airflow workstation for processing a sterile pharmaceutical product is required to be "Grade A," according to EU-GMP and WHO-GMP. These regulations have employed the wording of "laminar airflow" for unidirectional airflow, with an unclear definition given. This seems to have allowed many reports to describe discussion of airflow velocity only. The guidance values as to the velocity are expressed in various words of 90 ft/min, 0.45 m/sec, 0.3 m/sec, +/- 20%, or "homogeneous air speed." It has been also little clarified how variation in airflow velocity gives influences on contamination control of a workstation working with varying key characteristics, such as ceiling height, internal heat load, internal particle generation, etc. The present author has revealed following points from a case study using Computational Fluid Dynamics: the airflow characteristic in Grade A area shows no significant changes with varying the velocity of supplied airflow, and the particles generated from the operator will be exhausted outside Grade A area without contamination.

  18. Validation and Verification (V and V) Testing on Midscale Flame Resistant (FR) Test Method

    DTIC Science & Technology

    2016-12-16

    SENSORS VALIDATION BURNS(INJURIES) FLAME RESISTANT CLOTHING TEXTILES HEAT FLUX HEAT...FLUX SENSORS CONVECTION(HEAT TRANSFER) MANIKINS VERIFICATION RADIANT HEAT FLUX V&V(VERIFICATION AND VALIDATION) U.S...10  Figure 5. F1930 sensor maps. (a) Sensor map showing 16 selected sensors on

  19. Optimal Determination of Respiratory Airflow Patterns Using a Nonlinear Multicompartment Model for a Lung Mechanics System

    PubMed Central

    Li, Hancao; Haddad, Wassim M.

    2012-01-01

    We develop optimal respiratory airflow patterns using a nonlinear multicompartment model for a lung mechanics system. Specifically, we use classical calculus of variations minimization techniques to derive an optimal airflow pattern for inspiratory and expiratory breathing cycles. The physiological interpretation of the optimality criteria used involves the minimization of work of breathing and lung volume acceleration for the inspiratory phase, and the minimization of the elastic potential energy and rapid airflow rate changes for the expiratory phase. Finally, we numerically integrate the resulting nonlinear two-point boundary value problems to determine the optimal airflow patterns over the inspiratory and expiratory breathing cycles. PMID:22719793

  20. Optimal determination of respiratory airflow patterns using a nonlinear multicompartment model for a lung mechanics system.

    PubMed

    Li, Hancao; Haddad, Wassim M

    2012-01-01

    We develop optimal respiratory airflow patterns using a nonlinear multicompartment model for a lung mechanics system. Specifically, we use classical calculus of variations minimization techniques to derive an optimal airflow pattern for inspiratory and expiratory breathing cycles. The physiological interpretation of the optimality criteria used involves the minimization of work of breathing and lung volume acceleration for the inspiratory phase, and the minimization of the elastic potential energy and rapid airflow rate changes for the expiratory phase. Finally, we numerically integrate the resulting nonlinear two-point boundary value problems to determine the optimal airflow patterns over the inspiratory and expiratory breathing cycles.

  1. 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.

  2. Evaluation of the Kirby-Bauer disc diffusion test as a screening test for high-level aminoglycoside resistance in enterococci.

    PubMed

    Pfaller, M A; Niles, A C; Murray, P R

    1984-10-01

    The Kirby-Bauer disc diffusion test was evaluated as a test to detect high-level aminoglycoside (streptomycin, kanamycin, tobramycin, and gentamicin) resistance in isolates of enterococci. The authors found that high-level resistance could not be predicted accurately with the diffusion test.

  3. Ballistic Resistance of Armored Passenger Vehicles: Test Protocols and Quality Methods

    SciTech Connect

    Jeffrey M. Lacy; Robert E. Polk

    2005-07-01

    This guide establishes a test methodology for determining the overall ballistic resistance of the passenger compartment of assembled nontactical armored passenger vehicles (APVs). Because ballistic testing of every piece of every component of an armored vehicle is impractical, if not impossible, this guide describes a testing scheme based on statistical sampling of exposed component surface areas. Results from the test of the sampled points are combined to form a test score that reflects the probability of ballistic penetration into the passenger compartment of the vehicle.

  4. 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.

  5. CFD simulation of turbulent airflow around wind turbine airfoils

    NASA Astrophysics Data System (ADS)

    Halbrooks, David N.

    The airflow around wind turbines has proved to be a difficult problem to approach by means of today's Computational Fluid Dynamics (CFD) codes. One reason for this difficulty lies within the stall characteristics of turbine airfoils. For the purposes of this research, the popular commercial CFD code, FLUENT was employed to facilitate the understanding of airflow around wind turbines through the study of various turbulence models. Parallel processing was employed to enhance computational performance as well as lower simulation times. The system used for simulation is the National Renewable Energy Laboratory (NREL) Phase VI Wind Turbine. The coefficients of pressure for the airfoil were extracted from the simulated data and compared against data obtained during the NREL Phase VI Wind Turbine data campaign. Since power is a driving factor of the design of wind turbine blades, the aspect of power was also examined and compared. After the completion of the baseline study, a parametric study was carried out to examine the effects of rotor speed downstream of the turbine blades.

  6. Clinical Rationale for Confirmation Testing After Treatment of Helicobacter pylori Infection: Implications of Rising Antibiotic Resistance

    PubMed Central

    Howden, Colin W.; Chey, William D.; Vakil, Nimish B.

    2014-01-01

    Helicobacter pylori (H pylori) infection is one of the most common chronic bacterial infections worldwide. International guidelines recommend H pylori eradication in several scenarios: patients with peptic ulcer disease, patients who have had endoscopic resection of early gastric cancer, and patients with a gastric mucosa-associated lymphoid tissue lymphoma (MALToma). There is variability among the guidelines for other conditions. Treatment options for H pylori infection include triple, quadruple, and sequential therapy. Ideally, patients in whom previous eradication attempts failed and those suspected to have resistant strains should be considered for antimicrobial sensitivity testing, which requires culture of gastric mucosal biopsies; such testing, however, has limited availability in the United States. Resistance rates vary by location depending on local antibiotic usage rates. As such, the success rates associated with different regimens vary throughout the world. Many patients with H pylori infection are asymptomatic, whereas others are diagnosed with the infection during evaluation of dyspeptic symptoms or following a diagnosis of peptic ulcer. Symptoms may not be an accurate indicator of treatment success. The American College of Gastroenterology (ACG) endorses the carbon 13-labeled urea breath test (13C-UBT) as the most reliable test to confirm H pylori eradication. This clinical roundtable monograph begins with an overview of H pylori infection and then discusses treatment, antibiotic resistance, management of patients with antibiotic resistance, and posttreatment testing, with a focus on the ACG guidelines. PMID:25892981

  7. Skid resistance and surface roughness testing of historic stone surfaces: advantages and limitations

    NASA Astrophysics Data System (ADS)

    Török, Ákos

    2013-04-01

    Skid resistance tests are mostly applied for testing road surfaces and almost never applied for testing stones at cultural heritage sites. The present study focuses on the possibilities of using these techniques in assessing the surface roughness of paving stones at a historic site. Two different methods were used in a comparative way to evaluate the surface properties of various types of stones ranging from travertine to non-porous limestone and granite. The applied techniques included the use of SRT pendulum (Skid Resistance Tester) providing USRV values and a mobile equipment to analyze the surface properties (Floor Slide Control) by surface profiling and providing angle of friction. The main aims of tests were to understand the wearing of stone materials due to intense pedestrian use and to detect surface changes/surface roughness and slip resistance within few year periods. The measured loss in surface slip resistance (i.e. USRV values) was in the order of 20% for granites, while most limestones lost at least 40% in terms of USRV values. An opposite trend was detected for a porous travertine type, where the surface became rougher after years of use. The limitations of these techniques are also addressed in the paper. The tests have shown that the introduction of the use of these equipments in heritage studies provide useful information on the longevity of historic stone pavements that are open for public use.

  8. Statistical variations in impact resistance of steel fiber-reinforced concrete subjected to drop weight test

    SciTech Connect

    Nataraja, M.C.; Dhang, N.; Gupta, A.P.

    1999-07-01

    The variation in impact resistance of steel fiber-reinforced concrete and plain concrete as determined from a drop weight test is reported. The observed coefficients of variation are about 57 and 46% for first-crack resistance and the ultimate resistance in the case of fiber concrete and the corresponding values for plain concrete are 54 and 51%, respectively. The goodness-of-fit test indicated poor fitness of the impact-resistance test results produced in this study to normal distribution at 95% level of confidence for both fiber-reinforced and plain concrete. However, the percentage increase in number of blows from first crack to failure for both fiber-reinforced concrete and as well as plain concrete fit to normal distribution as indicated by the goodness-of-fit test. The coefficient of variation in percentage increase in the number of blows beyond first crack for fiber-reinforced concrete and plain concrete is 51.9 and 43.1%, respectively. Minimum number of tests required to reliably measure the properties of the material can be suggested based on the observed levels of variation.

  9. Corrosion resistance and electrochemical potentiokinetic reactivation testing of some iron-base hardfacing alloys

    SciTech Connect

    Cockeram, B.V.

    1999-11-01

    Hardfacing alloys are weld deposited on a base material to provide a wear resistant surface. Commercially available iron-base hardfacing alloys are being evaluated for replacement of cobalt-base alloys to reduce nuclear plant activation levels. Corrosion testing was used to evaluate the corrosion resistance of several iron-base hardfacing alloys in highly oxygenated environments. The corrosion test results indicate that iron-base hardfacing alloys in the as-deposited condition have acceptable corrosion resistance when the chromium to carbon ratio is greater than 4. Tristelle 5183, with a high niobium (stabilizer) content, did not follow this trend due to precipitation of niobium-rich carbides instead of chromium-rich carbides. This result indicates that iron-base hardfacing alloys containing high stabilizer contents may possess good corrosion resistance with Cr:C < 4. NOREM 02, NOREM 01, and NoCo-M2 hardfacing alloys had acceptable corrosion resistance in the as-deposited and 885 C/4 hour heat treated condition, but rusting from sensitization was observed in the 621 C/6 hour heat treated condition. The feasibility of using an Electrochemical Potentiokinetic Reactivation (EPR) test method, such as used for stainless steel, to detect sensitization in iron-base hardfacing alloys was evaluated. A single loop-EPR method was found to provide a more consistent measurement of sensitization than a double loop-EPR method. The high carbon content that is needed for a wear resistant hardfacing alloy produces a high volume fraction of chromium-rich carbides that are attacked during EPR testing. This results in inherently lower sensitivity for detection of a sensitized iron-base hardfacing alloy than stainless steel using conventional EPR test methods.

  10. Tokamaks with high-performance resistive magnets: advanced test reactors and prospects for commercial applications

    SciTech Connect

    Bromberg, L.; Cohn, D.R.; Williams, J.E.C.; Becker, H.; Leclaire, R.; Yang, T.

    1981-10-01

    Scoping studies have been made of tokamak reactors with high performance resistive magnets which maximize advantages gained from high field operation and reduced shielding requirements, and minimize resistive power requirements. High field operation can provide very high values of fusion power density and n tau/sub e/ while the resistive power losses can be kept relatively small. Relatively high values of Q' = Fusion Power/Magnet Resistive Power can be obtained. The use of high field also facilitates operation in the DD-DT advanced fuel mode. The general engineering and operational features of machines with high performance magnets are discussed. Illustrative parameters are given for advanced test reactors and for possible commercial reactors. Commercial applications that are discussed are the production of fissile fuel, electricity generation with and without fissioning blankets and synthetic fuel production.

  11. Finite element analysis and fracture resistance testing of a new intraradicular post

    PubMed Central

    YAMAMOTO, Eron Toshio Colauto; PAGANI, Clovis; da SILVA, Eduardo Galera; NORITOMI, Pedro Yoshito; UEHARA, André Yugou; KEMMOKU, Daniel Takanori

    2012-01-01

    Objectives The objective of the present study was to evaluate a prefabricated intraradicular threaded pure titanium post, designed and developed at the São José dos Campos School of Dentistry - UNESP, Brazil. This new post was designed to minimize stresses observed with prefabricated post systems and to improve cost-benefits. Material and methods Fracture resistance testing of the post/core/root complex, fracture analysis by microscopy and stress analysis by the finite element method were used for post evaluation. The following four prefabricated metal post systems were analyzed: group 1, experimental post; group 2, modification of the experimental post; group 3, Flexi Post, and group 4, Para Post. For the analysis of fracture resistance, 40 bovine teeth were randomly assigned to the four groups (n=10) and used for the fabrication of test specimens simulating the situation in the mouth. The test specimens were subjected to compressive strength testing until fracture in an EMIC universal testing machine. After fracture of the test specimens, their roots were sectioned and analyzed by microscopy. For the finite element method, specimens of the fracture resistance test were simulated by computer modeling to determine the stress distribution pattern in the post systems studied. Results The fracture test presented the following averages and standard deviation: G1 (45.63±8.77), G2 (49.98±7.08), G3 (43.84±5.52), G4 (47.61±7.23). Stress was homogenously distributed along the body of the intraradicular post in group 1, whereas high stress concentrations in certain regions were observed in the other groups. These stress concentrations in the body of the post induced the same stress concentration in root dentin. Conclusions The experimental post (original and modified versions) presented similar fracture resistance and better results in the stress analysis when compared with the commercial post systems tested (08/2008-PA/CEP). PMID:23032204

  12. Patient-specific modelling of pulmonary airflow using GPU cluster for the application in medical practice.

    PubMed

    Miki, T; Wang, X; Aoki, T; Imai, Y; Ishikawa, T; Takase, K; Yamaguchi, T

    2012-01-01

    In this paper, we propose a novel patient-specific method of modelling pulmonary airflow using graphics processing unit (GPU) computation that can be applied in medical practice. To overcome the barriers imposed by computation speed, installation price and footprint to the application of computational fluid dynamics, we focused on GPU computation and the lattice Boltzmann method (LBM). The GPU computation and LBM are compatible due to the characteristics of the GPU. As the optimisation of data access is essential for the performance of the GPU computation, we developed an adaptive meshing method, in which an airway model is covered by isotropic subdomains consisting of a uniform Cartesian mesh. We found that 4(3) size subdomains gave the best performance. The code was also tested on a small GPU cluster to confirm its performance and applicability, as the price and footprint are reasonable for medical applications.

  13. Iodometric Detection of Haemophilus influenzae Beta-Lactamase: Rapid Presumptive Test for Ampicillin Resistance

    PubMed Central

    Catlin, B. Wesley

    1975-01-01

    Strains of Haemophilus influenzae type b sporadically isolated from clinical specimens are ampicillin resistant due to production of a β-lactamase. This enzyme which inactivates ampicillin and penicillin G is not produced by ampicillin-susceptible strains. Various characteristics of β-lactamase production and ampicillin resistance of three H. influenzae type b isolates were investigated. A sensitive iodometric test was employed to detect β-lactamase; positive results were obtained in 5 min with 109 bacteria taken from cultures on a nutritionally adequate agar medium. This simple chemical test will enable the hospital laboratory to obtain presumptive evidence of ampicillin resistance on the same day that H. influenzae is isolated. PMID:1079712

  14. Resistance to Second-Line Antituberculosis Drugs and Delay in Drug Susceptibility Testing among Multidrug-Resistant Tuberculosis Patients in Shanghai

    PubMed Central

    Yuan, Zhengan; Shen, Xin; Wu, Jie; Wu, Zheyuan

    2016-01-01

    Introduction. Second-line antituberculosis drugs (SLDs) are used for treating multidrug-resistant tuberculosis (MDR-TB). Prolonged delays before confirming MDR-TB with drug susceptibility testing (DST) could result in transmission of drug-resistant strains and inappropriate use of SLDs, thereby increasing the risk of resistance to SLDs. This study investigated the diagnostic delay in DST and prevalence of baseline SLD resistance in Shanghai and described the distribution of SLD resistance with varied delays to DST. Methods. All registered patients from 2011 to 2013 in Shanghai were enrolled. Susceptibility to ofloxacin, amikacin, kanamycin, and capreomycin was tested. Total delay in DST completion was measured from the onset of symptoms to reporting DST results. Results. Resistance to SLDs was tested in 217 of the 276 MDR-TB strains, with 118 (54.4%) being resistant to at least one of the four SLDs. The median total delay in DST was 136 days. Patients with delay longer than median days were roughly twice more likely to have resistance to at least one SLD (OR 2.22, 95% CI 1.19–4.11). Conclusions. During prolonged delay in DST, primary and acquired resistance to SLDs might occur more frequently. Rapid diagnosis of MDR-TB, improved nosocomial infection controls, and regulated treatment are imperative to prevent SLD resistance. PMID:27652260

  15. Resistance to Second-Line Antituberculosis Drugs and Delay in Drug Susceptibility Testing among Multidrug-Resistant Tuberculosis Patients in Shanghai.

    PubMed

    Chen, Yong; Yuan, Zhengan; Shen, Xin; Wu, Jie; Wu, Zheyuan; Xu, Biao

    2016-01-01

    Introduction. Second-line antituberculosis drugs (SLDs) are used for treating multidrug-resistant tuberculosis (MDR-TB). Prolonged delays before confirming MDR-TB with drug susceptibility testing (DST) could result in transmission of drug-resistant strains and inappropriate use of SLDs, thereby increasing the risk of resistance to SLDs. This study investigated the diagnostic delay in DST and prevalence of baseline SLD resistance in Shanghai and described the distribution of SLD resistance with varied delays to DST. Methods. All registered patients from 2011 to 2013 in Shanghai were enrolled. Susceptibility to ofloxacin, amikacin, kanamycin, and capreomycin was tested. Total delay in DST completion was measured from the onset of symptoms to reporting DST results. Results. Resistance to SLDs was tested in 217 of the 276 MDR-TB strains, with 118 (54.4%) being resistant to at least one of the four SLDs. The median total delay in DST was 136 days. Patients with delay longer than median days were roughly twice more likely to have resistance to at least one SLD (OR 2.22, 95% CI 1.19-4.11). Conclusions. During prolonged delay in DST, primary and acquired resistance to SLDs might occur more frequently. Rapid diagnosis of MDR-TB, improved nosocomial infection controls, and regulated treatment are imperative to prevent SLD resistance.

  16. Active surveillance for carbapenem-resistant Enterobacteriaceae using stool specimens submitted for testing for Clostridium difficile.

    PubMed

    Banach, David B; Francois, Jeannette; Blash, Stephanie; Patel, Gopi; Jenkins, Stephen G; LaBombardi, Vincent; Kreiswirth, Barry N; Srinivasan, Arjun; Calfee, David P

    2014-01-01

    Active surveillance to identify asymptomatic carriers of carbapenem-resistant Enterobacteriaceae (CRE) is a recommended strategy for CRE control in healthcare facilities. Active surveillance using stool specimens tested for Clostridium difficile is a relatively low-cost strategy to detect CRE carriers. Further evaluation of this and other risk factor-based active surveillance strategies is warranted.

  17. Wildfire ignition resistant home design(WIRHD) program: Full-scale testing and demonstration final report.

    SciTech Connect

    Quarles, Stephen, L.; Sindelar, Melissa

    2011-12-13

    The primary goal of the Wildfire ignition resistant home design(WIRHD) program was to develop a home evaluation tool that could assess the ignition potential of a structure subjected to wildfire exposures. This report describes the tests that were conducted, summarizes the results, and discusses the implications of these results with regard to the vulnerabilities to homes and buildings.

  18. Effects of Resistance Training on the Sit-and-Reach Test in Elderly Women.

    ERIC Educational Resources Information Center

    Barbosa, Aline Rodrigues; Santarem Jose Maria; Filho, Wilson Jacob; Marucci, Maria de Fatima Nunes

    2002-01-01

    Examined the effects of a 10-week resistance training program on older women's flexibility (evaluated through the sit- and-reach test performed before and after the training program). Participants were compared to inactive older women. The training program resulted in significant increases in participants' flexibility, suggesting that weight…

  19. Numerical Analysis Of The Resistance To Pullout Test Of Clinched Assemblies Of Thin Metal Sheets

    SciTech Connect

    Jomaa, Moez; Billardon, Rene

    2007-04-07

    This paper presents the finite element analysis of the resistance of a clinch point to pullout test -that follows the numerical analysis of the forming process of the point-. The simulations have been validated by comparison with experimental evidences. The influence on the numerical predictions of various computation and process parameters have been evaluated.

  20. Sequence types of Staphylococcus epidermidis associated with prosthetic joint infections are not present in the laminar airflow during prosthetic joint surgery.

    PubMed

    Månsson, Emeli; Hellmark, Bengt; Sundqvist, Martin; Söderquist, Bo

    2015-07-01

    Molecular characterization of Staphylococcus epidermidis isolates from prosthetic joint infections (PJIs) has demonstrated a predominance of healthcare-associated multi-drug resistant sequence types (ST2 and ST215). How, and when, patients acquire these nosocomial STs is not known. The aim was to investigate if sequence types of S. epidermidis associated with PJIs are found in the air during prosthetic joint surgery. Air sampling was undertaken during 17 hip/knee arthroplasties performed in operating theaters equipped with mobile laminar airflow units in a 500-bed hospital in central Sweden. Species identification was performed using MALDI-TOF MS and 16S rRNA gene analysis. Isolates identified as S. epidermidis were further characterized by MLST and antibiotic susceptibility testing. Seven hundred and thirty-five isolates were available for species identification. Micrococcus spp. (n = 303) and coagulase-negative staphylococci (n = 217) constituted the majority of the isolates. Thirty-two isolates of S. epidermidis were found. S. epidermidis isolates demonstrated a high level of allelic diversity with 18 different sequence types, but neither ST2 nor ST215 was found. Commensals with low pathogenic potential dominated among the airborne microorganisms in the operating field during prosthetic joint surgery. Nosocomial sequence types of S. epidermidis associated with PJIs were not found, and other routes of inoculation are therefore of interest in future studies.

  1. Reconstructing atmospheric circulation over southern New Zealand: Establishment of modern westerly airflow 5500 years ago and implications for Southern Hemisphere Holocene climate change

    NASA Astrophysics Data System (ADS)

    Turney, C. S. M.; Wilmshurst, J. M.; Jones, R. T.; Wood, J. R.; Palmer, J. G.; Hogg, A. G.; Fenwick, P.; Crowley, S. F.; Privat, K.; Thomas, Z.

    2017-03-01

    Late-twentieth century changes in the intensity and migration of Southern Hemisphere westerly winds have been implicated in spatially complex variability in atmospheric and ocean circulation, and ice-sheet dynamics, across the mid- to high-latitudes. A major uncertainty, however, is whether present day hemispheric-wide symmetrical airflow is representative of past behaviour. Here we report a multi-proxy study from Stewart Island and southern Fiordland, New Zealand (46-47°S) reconstructing Holocene changes at the northern limit of westerly airflow. Increased minerogenic input and a pronounced shift in cool-loving vegetation around 5500 years ago is consistent with the establishment of westerly airflow at this latitude in the southwest Pacific. In marked contrast, stronger winds are reported further south over the subantarctic Auckland (50°S) and Campbell (52°S) Islands from 8000 years ago. Intriguingly, reconstructions from the east Pacific suggest a weakening of core westerly airflow after 8500 years ago, but an expansion along the northern limits sometime after 5500 years ago. Our results suggest similar atmospheric circulation changes have been experienced in the Pacific since 5500 years ago, but indicate an expanded network of sites is needed to comprehensively test the driver(s) and impact(s) of Holocene mid-latitude westerly winds across the Southern Hemisphere.

  2. 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.

  3. 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)

  4. Effects of partial middle turbinectomy with varying resection volume and location on nasal functions and airflow characteristics by CFD.

    PubMed

    Lee, Kyun Bum; Jeon, Young Sun; Chung, Seung-Kyu; Kim, Sung Kyun

    2016-10-01

    The surgical term "turbinectomy" encompasses many variations in the location and extent of removal. As a systemic approach to consider the negative impact of middle turbinectomy(MT), such as the excessive removal of turbinate, airflows inside a pre-surgery model and a series of virtual surgery models were numerically analyzed and compared. These models simulate three variations of partial MT(three bilateral and three unilateral) with varying resection volume and location. Each middle turbinectomy results in alterations of flow and thermal parameters, such as nasal resistance (NR), velocity, temperature, wall shear stress(WSS) and wall heat transfer(WHT). WSS distributions were also considered in connection with mucosal secretion. The tendency of changes in nasal functions and airflow characteristics was identified with respect to resection volume and location. A counter-rotating vortical structure was seen in the region of widened middle airway for the case of total resection of middle turbinate. Maximum velocity and WSS near sphenopalatine ganglion, which was a possible explanation for headache after total resection of middle turbinate, was increased. Changes in NR and WHT for bi-lateral resection cases were greater than those for unilateral resection cases. While the physiological changes in four partial MT models were insignificant, changes in near total resection model was prominent. Although our surgical simulation was done for a single case, we postulate that the removal of the anterior inferior part of middle turbinate while preserving posterior margin will not alter airflow characteristics extensively. These findings will help designing surgical plans for partial MT.

  5. Regulating glottal airflow in phonation: Application of the maximum power transfer theorem to a low dimensional phonation model

    NASA Astrophysics Data System (ADS)

    Titze, Ingo R.

    2002-01-01

    Two competing views of regulating glottal airflow for maximum vocal output are investigated theoretically. The maximum power transfer theorem is used as a guide. A wide epilarynx tube (laryngeal vestibule) matches well with low glottal resistance (believed to correspond to the ``yawn-sigh'' approach in voice therapy), whereas a narrow epilarynx tube matches well with a higher glottal resistance (believed to correspond to the ``twang-belt'' approach). A simulation model is used to calculate mean flows, peak flows, and oral radiated pressure for an impedance ratio between the vocal tract (the load) and the glottis (the source). Results show that when the impedance ratio approaches 1.0, maximum power is transferred and radiated from the mouth. A full update of the equations used for simulating driving pressures, glottal flow, and vocal tract input pressures is provided as a programming guide for those interested in model development.

  6. Determination of Heritage SSME Pogo Suppressor Resistance and Inertance from Waterflow Pulse Testing

    NASA Technical Reports Server (NTRS)

    McDougal, Chris; Eberhart, Chad; Lee, Erik

    2016-01-01

    Waterflow tests of a heritage Space Shuttle Main Engine pogo suppressor were performed to experimentally quantify the resistance and inertance provided by the suppressor. Measurements of dynamic pressure and flow rate in response to pulsing flow were made throughout the test loop. A unique system identification methodology combined all sensor measurements with a one-dimensional perturbational flow model of the complete water flow loop to spatially translate physical measurements to the device under test. Multiple techniques were then employed to extract the effective resistance and inertance for the pogo suppressor. Parameters such as steady flow rate, perturbational flow rate magnitude, and pulse frequency were investigated to assess their influence on the behavior of the pogo suppressor dynamic response. These results support validation of the RS-25 pogo suppressor performance for use on the Space Launch System Core Stage.

  7. Bronchial hypersecretion, chronic airflow limitation, and peptic ulcer.

    PubMed

    Kauffmann, F; Brille, D

    1981-11-01

    Men with and men without a history of peptic ulcers were compared using respiratory symptoms and spirographic measurements taken from data recorded in an epidemiologic study. Among the 1,049 men examined, 7% reported a history of peptic ulcer. A clear relationship appeared between bronchial hypersecretion and peptic ulcers. It persisted after adjustment for age, smoking habits, social class, and country of origin. Men with ulcers inhaled tobacco smoke more often. Ulcers, smoking, and chronic phlegm were independently related to a lower body build index. It seems that the relationship between smoking and ulcers was greater among men with chronic phlegm, and it is postulated that peptic ulcers and "chronic bronchitis" might be related to a "common secretory disorder." After adjustment for age, men with a history of peptic ulcers had, not a lower FEV1, but a higher vital capacity. A slightly lower FEV1/VC ratio cannot in such cases be considered as an index of chronic airflow limitation.

  8. Mushrooms use convectively created airflows to disperse their spores

    PubMed Central

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

    2016-01-01

    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

  9. 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

  10. Mechanics of airflow in the human nasal airways.

    PubMed

    Doorly, D J; Taylor, D J; Schroter, R C

    2008-11-30

    The mechanics of airflow in the human nasal airways is reviewed, drawing on the findings of experimental and computational model studies. Modelling inevitably requires simplifications and assumptions, particularly given the complexity of the nasal airways. The processes entailed in modelling the nasal airways (from defining the model, to its production and, finally, validating the results) is critically examined, both for physical models and for computational simulations. Uncertainty still surrounds the appropriateness of the various assumptions made in modelling, particularly with regard to the nature of flow. New results are presented in which high-speed particle image velocimetry (PIV) and direct numerical simulation are applied to investigate the development of flow instability in the nasal cavity. These illustrate some of the improved capabilities afforded by technological developments for future model studies. The need for further improvements in characterising airway geometry and flow together with promising new methods are briefly discussed.

  11. Airflow design for cleanrooms and its economic implications

    SciTech Connect

    Xu, Tengfang

    2002-08-20

    A cleanroom is designed to control the concentration of airborne particles. As a result, large amount of cleaned air is often required to remove or dilute contaminants for satisfactory operations in critical cleanroom environment. Cleanroom environmental systems (HVAC systems) in semiconductor, pharmaceutical, and healthcare industries are much more energy intensive compared to their counterparts (HVAC systems) serving commercial buildings such as typical office buildings. There is a tendency in cleanroom design and operation, however, to provide excessive airflow rates by HVAC systems, largely due to design conservatism, lack of understanding in airflow requirements, and more often, concerns such as cleanliness reliability, design and operational liabilities. A combination of these likely factors can easily result in HVAC systems' over-design. Energy use of cleanroom environmental systems varies with the system design, cleanroom functions, and critical parameter control including temperatures and humidities. In particular, cleanroom cleanliness requirements specified by ''cleanliness class'' [1],[2] often cast large impact on energy use. A review of studies on cleanroom operation costs indicated that energy costs could amount to 65-75% of the total annual cost associated with cleanroom operation and maintenance in some European countries[3]. Depending on cleanroom cleanliness classes, annual cleanroom electricity use for cooling and fan energy ranged approximately between 1,710 kWh/m{sup 2} and 10,200 kWh/m{sup 2} (or 160 kWh/ft{sup 2} and 950 kWh/ft{sup 2}) in California[4], USA. Cleanroom fan energy use typically consumed half of total HVAC energy use in three states in the USA[5]. For cleanrooms in a wafer-process semiconductor factory in Japan[6], HVAC systems used 43% of power consumption of an entire cleanroom factory, while air delivery systems account for 30% of the total power consumption. Fan energy use for cleanrooms of ISO Classes 3,4,5 collectively

  12. 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.

  13. Targeted Drug-Resistance Testing Strategy for Multidrug-Resistant Tuberculosis Detection, Lima, Peru, 2005–2008

    PubMed Central

    Velásquez, Gustavo E.; Yagui, Martin; Cegielski, J. Peter; Asencios, Luis; Bayona, Jaime; Bonilla, Cesar; Jave, Hector O.; Yale, Gloria; Suárez, Carmen; Atwood, Sidney; Contreras, Carmen C.

    2011-01-01

    The Peruvian National Tuberculosis Control Program issued guidelines in 2006 specifying criteria for culture and drug-susceptibility testing (DST), including district-level rapid DST. All patients referred for culture and DST in 2 districts of Lima, Peru, during January 2005–November 2008 were monitored prospectively. Of 1,846 patients, 1,241 (67.2%) had complete DST results for isoniazid and rifampin; 419 (33.8%) patients had multidrug-resistant (MDR) TB at the time of referral. Among patients with new smear-positive TB, household contact and suspected category I failure were associated with MDR TB, compared with concurrent regional surveillance data. Among previously treated patients with smear-positive TB, adult household contact, suspected category II failure, early relapse after category I, and multiple previous TB treatments were associated with MDR TB, compared with concurrent regional surveillance data. The proportion of MDR TB detected by using guidelines was higher than that detected by a concurrent national drug-resistance survey, indicating that the strategy effectively identified patients for DST. PMID:21392434

  14. Induced airflow in flying insects II. Measurement of induced flow.

    PubMed

    Sane, Sanjay P; Jacobson, Nathaniel P

    2006-01-01

    The flapping wings of insects and birds induce a strong flow over their body during flight. Although this flow influences the sensory biology and physiology of a flying animal, there are very little data on the characteristics of this self-generated flow field or its biological consequences. A model proposed in the companion paper estimated the induced flow over flying insects. In this study, we used a pair of hot wire anemometers to measure this flow at two locations near the body of a tethered flapping hawk moth, Manduca sexta. The axial inflow anemometer measured the airflow prior to its entry into the stroke plane, whereas the radial outflow anemometer measured the airflow after it crossed the stroke plane. The high temporal resolution of the hot wire anemometers allowed us to measure not only the mean induced flow but also subtle higher frequency disturbances occurring at 1-4 times the wing beat frequency. These data provide evidence for the predictions of a mathematical model proposed in the companion paper. Specifically, the absolute value of the measured induced flow matches the estimate of the model. Also, as predicted by the model, the induced flow varies linearly with wing beat frequency. Our experiments also show that wing flexion contributes significantly to the observed higher frequency disturbances. Thus, the hot wire anemometry technique provides a useful means to quantify the aerodynamic signature of wing flexion. The phasic and tonic components of induced flow influence several physiological processes such as convective heat loss and gas exchange in endothermic insects, as well as alter the nature of mechanosensory and olfactory stimuli to the sensory organs of a flying insect.

  15. Is the test of senior friendly/child resistant packaging ethical?

    PubMed

    Bix, Laura; de la Fuente, Javier; Pimple, Kenneth D; Kou, Eric

    2009-12-01

    Research has documented the drastic reduction of unintentional poisonings of children since the introduction of child resistant (CR) packaging. However, studies also indicate that consumers report difficulty using CR packages, in part because tests which determine the 'senior friendliness' of CR designs that are used throughout the world disallow people with 'overt or obvious' disabilities from being test subjects. Our review of drug package usability suggests that the current tests of CR packaging can and should be revised to correct this problem. We use US legislation, regulation and data to exemplify these points, but the conclusions are applicable to all protocols that include the exclusionary provision.

  16. Field Testing of Energy-Efficient Flood-Damage-Resistant Residential Envelope Systems Summary Report

    SciTech Connect

    Aglan, H.

    2005-08-04

    The primary purpose of the project was to identify materials and methods that will make the envelope of a house flood damage resistant. Flood damage resistant materials and systems are intended to be used to repair houses subsequent to flooding. This project was also intended to develop methods of restoring the envelopes of houses that have been flooded but are repairable and may be subject to future flooding. Then if the house floods again, damage will not be as extensive as in previous flood events and restoration costs and efforts will be minimized. The purpose of the first pair of field tests was to establish a baseline for typical current residential construction practice. The first test modules used materials and systems that were commonly found in residential envelopes throughout the U.S. The purpose of the second pair of field tests was to begin evaluating potential residential envelope materials and systems that were projected to be more flood-damage resistant and restorable than the conventional materials and systems tested in the first pair of tests. The purpose of testing the third slab-on-grade module was to attempt to dry flood proof the module (no floodwater within the structure). If the module could be sealed well enough to prevent water from entering, then this would be an effective method of making the interior materials and systems flood damage resistant. The third crawl space module was tested in the same manner as the previous modules and provided an opportunity to do flood tests of additional residential materials and systems. Another purpose of the project was to develop the methodology to collect representative, measured, reproducible (i.e. scientific) data on how various residential materials and systems respond to flooding conditions so that future recommendations for repairing flood damaged houses could be based on scientific data. An additional benefit of collecting this data is that it will be used in the development of a standard test

  17. Non-Phenotypic Tests to Detect and Characterize Antibiotic Resistance Mechanisms in Enterobacteriaceae

    PubMed Central

    Lupo, Agnese; Papp-Wallace, Krisztina M.; Sendi, Parham; Bonomo, Robert A.; Endimiani, Andrea

    2014-01-01

    In the past two decades, we have observed a rapid increase of infections due to multidrug-resistant Enterobacteriaceae. Regrettably, these isolates possess genes encoding for extended-spectrum β-lactamases (e.g., blaCTX-M, blaTEM, blaSHV) or plasmid-mediated AmpCs (e.g., blaCMY) that confer resistance to last-generation cephalosporins. Furthermore, other resistance traits against quinolones (e.g., mutations in gyrA and parC, qnr elements) and aminoglycosides (e.g., aminoglycosides modifying enzymes and 16S rRNA methylases) are also frequently co-associated. Even more concerning is the rapid increase of Enterobacteriaceae carrying genes conferring resistance to carbapenems (e.g., blaKPC, blaNDM). Therefore, the spread of these pathogens puts in peril our antibiotic options. Unfortunately, standard microbiological procedures require several days to isolate the responsible pathogen and to provide correct antimicrobial susceptibility test results. This delay impacts the rapid implementation of adequate antimicrobial treatment and infection control countermeasures. Thus, there is emerging interest in the early and more sensitive detection of resistance mechanisms. Modern non-phenotypic tests are promising in this respect, and hence, can influence both clinical outcome and healthcare costs. In this review, we present a summary of the most advanced methods (e.g., next-generation DNA sequencing, multiplex PCRs, real-time PCRs, microarrays, MALDITOF MS, and PCR/ESI MS) presently available for the rapid detection of antibiotic resistance genes in Enterobacteriaceae. Taking into account speed, manageability, accuracy, versatility, and costs, the possible settings of application (research, clinic, and epidemiology) of these methods and their superiority against standard phenotypic methods are discussed. PMID:24091103

  18. Dynamics of a supersonic inlet-engine combination subjected to disturbances in fuel flow and inlet overboard bypass airflow

    NASA Technical Reports Server (NTRS)

    Wallhagen, R. E.; Paulovich, F. J.; Geyser, L. C.

    1972-01-01

    An axisymmetric mixed-compression supersonic inlet and a single-spool turbojet engine were dynamically tested at Mach 2.5. The propulsion system was subjected to sweep-frequency sinusoidal disturbances of either inlet overboard bypass airflow. The disturbances were at a logarithmic sweep rate of 1 decade per minute. Dynamic responses were taken of signals throughout the propulsion system. Selected signals were reduced relative to the prime propulsion system parameters. The experimental data are presented in Bode plots. Most of the plots are for a frequency range of 1.0 to 50 hertz.

  19. Contam airflow models of three large buildings: Model descriptions and validation

    SciTech Connect

    Black, Douglas R.; Price, Phillip N.

    2009-09-30

    Airflow and pollutant transport models are useful for several reasons, including protection from or response to biological terrorism. In recent years they have been used for deciding how many biological agent samplers are needed in a given building to detect the release of an agent; to figure out where those samplers should be located; to predict the number of people at risk in the event of a release of a given size and location; to devise response strategies in the event of a release; to determine optimal trade-offs between sampler characteristics (such as detection limit and response time); and so on. For some of these purposes it is necessary to model a specific building of interest: if you are trying to determine optimal sampling locations, you must have a model of your building and not some different building. But for many purposes generic or 'prototypical' building models would suffice. For example, for determining trade-offs between sampler characteristics, results from one building will carry over other, similar buildings. Prototypical building models are also useful for comparing or testing different algorithms or computational pproaches: different researchers can use the same models, thus allowing direct comparison of results in a way that is not otherwise possible. This document discusses prototypical building models developed by the Airflow and Pollutant Transport Group at Lawrence Berkeley National Laboratory. The models are implemented in the Contam v2.4c modeling program, available from the National Institutes for Standards and Technology. We present Contam airflow models of three virtual buildings: a convention center, an airport terminal, and a multi-story office building. All of the models are based to some extent on specific real buildings. Our goal is to produce models that are realistic, in terms of approximate magnitudes, directions, and speeds of airflow and pollutant transport. The three models vary substantially in detail. The airport model

  20. Prevalence of Airflow Limitation Defined by Pre- and Post-Bronchodilator Spirometry in a Community-Based Health Checkup: The Hisayama Study.

    PubMed

    Fukuyama, Satoru; Matsumoto, Koichiro; Kaneko, Yasuko; Kan-o, Keiko; Noda, Naotaka; Tajiri-Asai, Yukari; Nakano, Takako; Ishii, Yumiko; Kiyohara, Yutaka; Nakanishi, Yoichi; Inoue, Hiromasa

    2016-01-01

    Spirometry in health checkup may contribute to early diagnosis of chronic obstructive pulmonary disease (COPD) and asthma. Although post-bronchodilator airflow limitation is essential for definite diagnosis of COPD and post-bronchodilator normalization of airflow is suggestive of asthma, this test has not been prevailed in health checkup. The objective of this study was to estimate the prevalence of airflow limitation defined by pre- and post-bronchodilator spirometry in health checkup. Post-bronchodilator spirometry was conducted for participants with airflow limitation in a town-wide health checkup for residents aged 40 years and older in Hisayama, a town in the western part of Japan. The prevalence of pre- and post-bronchodilator airway limitation defined by FEV1/FVC < 70% were estimated. A total of 2,232 participants underwent pre-bronchodilator spirometry. In males, the age of current smokers was significantly younger than those of never smokers and former smokers. In females, the ages of current- and former smokers were significantly younger than never smokers. The values of %FEV1 and %FVC in current smokers were significantly lower than those in former smokers and never smokers. Two hundred sixty nine subjects, 85% of total subjects with a pre-bronchodilator FEV1/FVC < 70%, completed post-bronchodilator spirometry. The prevalence of pre-bronchodilator airflow limitation was 14.6% in males and 13.7% in females, and the prevalence of post-bronchodilator airway limitation was 8.7% and 8.7%, respectively. Post-bronchodilator spirometry in health checkup would reduce the number of subjects with probable COPD to two-third. Recommendation for those examinees to take further evaluations may pave the way for early intervention.

  1. Comparison of tests to detect oxacillin resistance in Staphylococcus intermedius, Staphylococcus schleiferi, and Staphylococcus aureus isolates from canine hosts.

    PubMed

    Bemis, David A; Jones, Rebekah D; Hiatt, Lauren E; Ofori, Edward D; Rohrbach, Barton W; Frank, Linda A; Kania, Stephen A

    2006-09-01

    Multiple tests were compared to the reference standard PBP2a latex agglutination test for detection of mecA-mediated oxacillin resistance in canine staphylococci. Cefoxitin disk diffusion, using breakpoints for human isolates of coagulase-negative Staphylococcus spp., had low sensitivity for detection of oxacillin resistance in members of the Staphylococcus intermedius group.

  2. The Relative Hydrodynamic Resistance of Various Types of Rivet Heads from Tests of Planning Surfaces, Special Report

    NASA Technical Reports Server (NTRS)

    Truscott, Starr; Parksinson, John B.

    1935-01-01

    The Committee was requested to investigate the effect of various types of rivet heads on hydrodynamic resistance. The proposal was made to obtain the resistance of the various types of rivets by tests of planing surfaces on which the full size rivets would be arranged. The testing methods, results and conclusions are given.

  3. Mechanism Development, Testing, and Lessons Learned for the Advanced Resistive Exercise Device

    NASA Technical Reports Server (NTRS)

    Lamoreaux, Christopher D.; Landeck, Mark E.

    2006-01-01

    The Advanced Resistive Exercise Device (ARED) has been developed at NASA Johnson Space Center, for the International Space Station (ISS) program. ARED is a multi-exercise, high-load resistive exercise device, designed for long duration, human space missions. ARED will enable astronauts to effectively maintain their muscle strength and bone mass in the micro-gravity environment more effectively than any other existing devices. ARED's resistance is provided via two, 20.3 cm (8 in) diameter vacuum cylinders, which provide a nearly constant resistance source. ARED also has a means to simulate the inertia that is felt during a 1-G exercise routine via the flywheel subassembly, which is directly tied to the motion of the ARED cylinders. ARED is scheduled to fly on flight ULF 2 to the ISS and will be located in Node 1. Presently, ARED is in the middle of its qualification and acceptance test program. An extensive testing program and engineering evaluation has increased the reliability of ARED by bringing potential design issues to light before flight production. Some of those design issues, resolutions, and design details will be discussed in this paper.

  4. High-resolution Electrical Resistivity Tomography monitoring of a tracer test in a confined aquifer

    NASA Astrophysics Data System (ADS)

    Wilkinson, P. B.; Meldrum, P. I.; Kuras, O.; Chambers, J. E.; Holyoake, S. J.; Ogilvy, R. D.

    2010-04-01

    A permanent geoelectrical subsurface imaging system has been installed at a contaminated land site to monitor changes in groundwater quality after the completion of a remediation programme. Since the resistivities of earth materials are sensitive to the presence of contaminants and their break-down products, 4-dimensional resistivity imaging can act as a surrogate monitoring technology for tracking and visualising changes in contaminant concentrations at much higher spatial and temporal resolution than manual intrusive investigations. The test site, a municipal car park built on a former gasworks, had been polluted by a range of polycyclic aromatic hydrocarbons and dissolved phase contaminants. It was designated statutory contaminated land under Part IIA of the UK Environmental Protection Act due to the risk of polluting an underlying minor aquifer. Resistivity monitoring zones were established on the boundaries of the site by installing vertical electrode arrays in purpose-drilled boreholes. After a year of monitoring data had been collected, a tracer test was performed to investigate groundwater flow velocity and to demonstrate rapid volumetric monitoring of natural attenuation processes. A saline tracer was injected into the confined aquifer, and its motion and evolution were visualised directly in high-resolution tomographic images in near real-time. Breakthrough curves were calculated from independent resistivity measurements, and the estimated seepage velocities from the monitoring images and the breakthrough curves were found to be in good agreement with each other and with estimates based on the piezometric gradient and assumed material parameters.

  5. Fault tolerant attitude control for small unmanned aircraft systems equipped with an airflow sensor array.

    PubMed

    Shen, H; Xu, Y; Dickinson, B T

    2014-11-18

    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.

  6. Evaluation tests of platinum resistance thermometers for a cryogenic wind tunnel application

    NASA Technical Reports Server (NTRS)

    Germain, E. F.; Compton, E. C.

    1984-01-01

    Thirty-one commercially designed platinum resistance thermometers were evaluated for applicability to stagnation temperature measurements between -190 C and +65 C in the Langley Research Center's National Transonic Facility. Evaluation tests included X-ray shadowgraphs, calibrations before and after aging, and time constant measurements. Two wire-wound low thermal mass probes of a conventional design were chosen as most suitable for this cryogenic wind tunnel application.

  7. Screening for cephalosporin-resistant Streptococcus pneumoniae with the Kirby-Bauer disk susceptibility test.

    PubMed

    Friedland, I R; Shelton, S; McCracken, G H

    1993-06-01

    Kirby-Bauer disk susceptibility tests with five standard cephalosporin disks were performed on 23 penicillin-resistant Streptococcus pneumoniae isolates for which ceftriaxone MICs were 0.125 to 4 micrograms/ml. Cefuroxime disk inhibition zone diameters distinguished clearly isolates for which ceftriaxone MICs were > or = 2 micrograms/ml from more susceptible strains, whereas cephalothin, ceftizoxime, cefotaxime, and ceftriaxone disks distinguished these isolates less clearly than the cefuroxime disk did.

  8. Comparison of six in vitro tests in determining benzimidazole and levamisole resistance in Haemonchus contortus and Ostertagia circumcincta of sheep.

    PubMed

    Várady, M; Corba, J

    1999-01-14

    Six in vitro methods for the detection of anthelmintic resistance were compared using benzimidazole/levamisole-resistant Haemonchus contortus and benzimidazole/levamisole/ivermectin-resistant Ostertagia circumcincta as well as susceptible strains of both parasite species. The degree of resistance to thiabendazole and levamisole was compared by (1) an egg hatch assay, (2) an egg hatch paralysis assay, (3) a larval development assay, (4) a larval paralysis assay (5) a larval paralysis assay with physostigmine and (6) larval micromotility assay. The degree of resistance for each assay was expressed as resistance factor--RF. For the detection of thiabendazole and levamisole resistance, the larval development test was observed as the most sensitive to measure quantitatively a degree of resistance between susceptible and resistant strains. For this test the RF for thiabendazole and levamisole was 14.3 and >32.5, respectively in H. contortus strains and 21.1 and 3.5 in strains of O. circumcincta. Egg hatch assay was also found to be sensitive and accurate in determining of resistance to benzimidazole. For measurement of levamisole resistance the egg hatch paralysis assay and larval paralysis assay were found to be able to distinguish between strains, but some disadvantages of these techniques make it unsuitable for field detection of levamisole resistance. Other in vitro assays as larval paralysis assay with physostigmine and larval micromotility assay were also investigated. Significant differences in paralysis of the larvae were observed using larval paralysis assay.

  9. On the stable hovering of an asymmetric body in oscillatory airflows

    NASA Astrophysics Data System (ADS)

    Liu, Bin; Weathers, Annie; Childress, Stephen; Zhang, Jun

    2010-03-01

    A free rigid body, built with up-down asymmetry can hover in a vertical oscillatory airflow if the airflow amplitude and frequency exceed certain thresholds. The key to free hovering lies in the difference in drag coefficients as the airflow passes the object in two opposite directions. The hovering motion is surprisingly stable and robust, lasting for thousands of oscillation periods. We describe a series of flow visualizations of vortex shedding by the hovering object, which show how correcting moments restore its orientation, leading to stable hovering. This study may shed light on the stability of the hovering flight of insects.

  10. Disorders of resonance and airflow secondary to cleft palate and/or velopharyngeal dysfunction.

    PubMed

    Kummer, Ann W

    2011-05-01

    The purpose of this article is to help the reader understand what contributes to normal resonance for speech production. In addition, the reader will learn about the types of resonance disorders and their characteristics. The causes of resonance disorders will be described with a guideline on how they should be treated. This article also includes a discussion of normal airflow for speech and the perceptual speech characteristics that often occur when there is abnormal nasal airflow. Secondary characteristics of nasal airflow, including weak or omitted consonants, short utterance length, nasal grimace, and compensatory articulation productions, are also described.

  11. Fs-laser micro machining for μ-TLM resistivity test structures in photovoltaic TCO multilayers

    NASA Astrophysics Data System (ADS)

    Krause, Stephan; Kaufmann, Kai; Lancaster, Kevin; Naumann, Volker; Großer, Stephan; Hagendorf, Christian

    2016-04-01

    In this work we developed a new approach for resistivity measurements based on fs laser micro machining of μ-TLM test structures. This method is applied to highly resistive interfacial and conductive bulk multilayer systems in photovoltaic TCO thin film devices. Resistivity data has been acquired by a new TLM based method at μm-dimensions (μ-TLM, patent pending, DE 102014211352.0). For this approach, isolating trenches are prepared in the µm range with reasonable effort using fs laser processing. The application of ultrashort pulses with a laser wavelength in the IR range (λ = 1.03 μm) allows selective removal of the top SnO2 layer of the TCO multilayer stack by a reduced thermal influence on the layers beneath and in the adjacent region of the laser trenches. Small effective optical penetration and ablation depth was achieved by an ultrafast thermal ablation mechanism via free carrier absorption at the interface of the SnO2/ITO layers. Therefore the risk of laser induced modification of the electric layer properties is negligible. The μ-TLM test structure results in highly accurate and reproducible resistivity data. Applied to SnO2/ITO/glass double layer stacks, the obtained resistivity values for the SnO2 interfacial layer (ρTO = 40.5 kΩμm) and for the indium tin oxide thin film (ρITO = 1.3 Ωμm) agree with reference data from four-point-probing and from literature.

  12. Developing a More Rapid Test to Assess Sulfate Resistance of Hydraulic Cements

    PubMed Central

    Ferraris, Chiara; Stutzman, Paul; Peltz, Max; Winpigler, John

    2005-01-01

    External sulfate attack of concrete is a major problem that can appear in regions where concrete is exposed to soil or water containing sulfates, leading to softening and cracking of the concrete. Therefore, it is important that materials selection and proportioning of concrete in susceptible regions be carefully considered to resist sulfate attack. American Society for Testing Materials (ASTM) limits the tricalcium aluminate phase in cements when sulfate exposure is of concern. The hydration products of tricalcium aluminate react with the sulfates resulting in expansion and cracking. While ASTM standard tests are available to determine the susceptibility of cements to sulfate attack, these tests require at least 6 months and often up to a year to perform; a delay that hinders development of new cements. This paper presents a new method for testing cement resistance to sulfate attack that is three to five times faster than the current ASTM tests. Development of the procedure was based upon insights on the degradation process by petrographic examination of sulfate-exposed specimens over time. Also key to the development was the use of smaller samples and tighter environmental control. PMID:27308177

  13. Assessing resistance against macrocyclic lactones in gastro-intestinal nematodes in cattle using the faecal egg count reduction test and the controlled efficacy test.

    PubMed

    De Graef, J; Sarre, C; Mills, B J; Mahabir, S; Casaert, S; De Wilde, N; Van Weyenberg, M; Geldhof, P; Marchiondo, A; Vercruysse, J; Meeus, P; Claerebout, E

    2012-10-26

    The main objective of the present study was to evaluate the accuracy of the faecal egg count reduction test (FECRT) to assess the resistance status of ivermectin (IVM)-resistant isolates of the cattle nematodes Ostertagia ostertagi and Cooperia oncophora, using the controlled efficacy test (worm counts) as a reference. The second objective was to investigate whether both IVM-resistant isolates showed side-resistance against moxidectin (MOX) under controlled conditions. Thirty male Holstein calves were experimentally infected with 25,000 L3 of an IVM-resistant O. ostertagi isolate and 25,000 L3 of an IVM-resistant C. oncophora isolate. Twenty-eight days later the calves were randomly divided into 2 treatment groups and 1 untreated control group. Animals in groups 1 and 2 received MOX (Cydectin(®) 1%, Pfizer) and IVM (Ivomec(®) 1%, Merial) respectively, by subcutaneous injection at a dose rate of 0.2mg/kg bodyweight. Faecal samples were collected 7 and 14 days after treatment and animals were necropsied 14/15 days post-treatment. Both the FECRT and the controlled efficacy test demonstrated that the O. ostertagi and C. oncophora isolates were resistant against IVM, with efficacies below 90%. The IVM-resistant O. ostertagia isolate was still susceptible to MOX treatment, as shown by over 99% reduction in egg counts and worm burden. The FECRT suggested borderline resistance against MOX in the IVM-resistant C. oncophora isolate, with egg count reductions between 97% (95% CI: 76; 100) at day 7 and 86% (95% CI: 49; 96) at day 14. However, the controlled efficacy test clearly showed MOX-resistance, with a decrease of only 31% (95% CI: -12; 57) in C. oncophora worm numbers. After MOX treatment, a significantly lower number of eggs per female C. oncophora worms was counted compared to the control group (43% reduction). Due to this reduced fecundity, the FECRT may fail to detect MOX-resistance.

  14. Multiscale Airflow Model and Aerosol Deposition in Healthy and Emphysematous Rat Lungs

    NASA Astrophysics Data System (ADS)

    Oakes, Jessica; Marsden, Alison; Grandmont, Celine; Darquenne, Chantal; Vignon-Clementel, Irene

    2012-11-01

    The fate of aerosol particles in healthy and emphysematic lungs is needed to determine the toxic or therapeutic effects of inhalable particles. In this study we used a multiscale numerical model that couples a 0D resistance and capacitance model to 3D airways generated from MR images. Airflow simulations were performed using an in-house 3D finite element solver (SimVascular, simtk.org). Seven simulations were performed; 1 healthy, 1 uniform emphysema and 5 different cases of heterogeneous emphysema. In the heterogeneous emphysema cases the disease was confined to a single lobe. As a post processing step, 1 micron diameter particles were tracked in the flow field using Lagrangian particle tracking. The simulation results showed that the inhaled flow distribution was equal for the healthy and uniform emphysema cases. However, in the heterogeneous emphysema cases the delivery of inhaled air was larger in the diseased lobe. Additionally, there was an increase in delivery of aerosol particles to the diseased lobe. This suggests that as the therapeutic particles would reach the diseased areas of the lung, while toxic particles would increasingly harm the lung. The 3D-0D model described here is the first of its kind to be used to study healthy and emphysematic lungs. NSF Graduate Fellowship (Oakes), Burroughs Wellcome Fund (Marsden, Oakes) 1R21HL087805-02 from NHLBI at NIH, INRIA Team Grant.

  15. Clopidogrel Resistance by P2Y12 Platelet Function Testing in Patients Undergoing Neuroendovascular Procedures

    PubMed Central

    Nordeen, Jerah D.; Patel, Alden V.; Darracott, Robert M.; Johns, Gretchen S.; Taussky, Philipp; Tawk, Rabih G.; Miller, David A.; Freeman, William D.; Hanel, Ricardo A.

    2013-01-01

    Purpose: The purpose of the study was to assess clopidogrel resistance and whether “intensified” antiplatelet therapy guided by platelet inhibition tests during neuroendovascular procedures would reduce ischemic complications. Methods: We conducted a retrospective review of patients at Mayo Clinic in Jacksonville, Florida, who underwent neuroendovascular (NV) procedures and had P2Y12 platelet function testing from October 1, 2009, to September 30, 2010. The primary end-point was to determine P2Y12 resistance to antiplatelet therapy in patients who underwent NV procedures. Secondary objectives included incidence of hemorrhagic and ischemic events and a correlation between resistance and genetic CYP2C19 testing. Results: 160 patients underwent P2Y12 platelet function tests. Eighty-one patients (81/160, 50.6%) met inclusion criteria. Platelet function tests identified 64 patients (79%) as non-resistant (≥20% P2Y12 inhibition) and 17 (21%) as resistant (<20% inhibition) after initial clopidogrel loading. There was an increased rate of death when a complication occurred in the resistant group by 30 day (17% versus 3%; p=0.059) and 90 day follow-up (23% versus 4%; p=0.032). There was no significant association found between complication and loading dose (p=0.0721). Conclusions: 21% of patients undergoing NV procedures were resistant to clopidogrel. Intensifying antiplatelet therapy to achieve ≥20% inhibition on platelet function testing did not result in higher numbers of ischemic or hemorrhagic events, but there was a trend toward more death in the resistant group by 30 and 90 days of those experiencing complication(s). Author Justifications: Jerah D. Nordeen, Pharm.D.: Primary author Alden V. Patel, Pharm.D.: Contributor of professional content, study design Robert M. Darracott, Pharm.D.: Contributor of professional content, study design Gretchen S. Johns, M.D.: Contributor of professional content, study design Philipp Taussky, M.D.: Contributor of professional

  16. Estimation of unsaturated hydraulic parameters in sandstone using electrical resistivity tomography under a water injection test

    NASA Astrophysics Data System (ADS)

    Farzamian, Mohammad; Monteiro Santos, Fernando A.; Khalil, Mohamed A.

    2015-10-01

    Hydraulic conductivity is an important soil property when determining the potential for water movement in topsoil and in spite of its importance; soil hydraulic conductivity remains one of the most difficult of soil properties to assess. Laboratory methods have limitations due to the size of the samples and taking undisturbed soil samples is usually difficult in sandy soil and in-situ methods are required to estimate hydraulic conductivity. This study was conducted to estimate saturated hydraulic conductivity in unsaturated sandstone using the ground surface electrical resistivity tomography (ERT). The site is characterized by a deep Arenosol soil with high permeability and a low water retention capacity located at the Semora-Correia, the east of Lisbon. Eight ERT snapshots were collected during a water injection test to produce a sequence of 2D resistivity images. Time-lapse ERT data were inverted using independent data inversion, the difference inversion and simultaneous space-time inversion methods. Afterward, using an in-situ approach resistivity variation models were converted to water content images. By comparing first and second spatial moments of water movement images inferred from the ERT method with unsaturated flow simulation predicted from a numerical solution of Richards' equation, the range of saturated hydraulic conductivity is estimated to be in 0.5-0.7 (cm/min). The evaluation of ERT approach was made using a synthetic test. The results of synthetic test showed that the estimated parameters were significantly influenced by the ERT inversion method and an overprediction of spatial moments and consequently saturated hydraulic conductivity was observed in all inversion methods; however the resistivity models obtained by simultaneous space-time inversion method was more successful in water movement monitoring.

  17. Oxacillin disk diffusion testing for the prediction of penicillin resistance in Streptococcus pneumoniae.

    PubMed

    Horna, Gertrudis; Molero, María L; Benites, Liliana; Roman, Sigri; Carbajal, Luz; Mercado, Erik; Castillo, María E; Zerpa, Rito; Chaparro, Eduardo; Hernandez, Roger; Silva, Wilda; Campos, Francisco; Saenz, Andy; Reyes, Isabel; Villalobos, Alex; Ochoa, Theresa J

    2016-08-01

    Objective To 1) describe the correlation between the zones of inhibition in 1-µg oxacillin disk diffusion (ODD) tests and penicillin and ceftriaxone minimum inhibitory concentrations (MICs) of meningeal and non-meningeal strains of Streptococcus pneumoniae and 2) evaluate the usefulness of the ODD test as a predictor of susceptibility to penicillin in S. pneumoniae and as a quick and cost-effective method easily implemented in a routine clinical laboratory setting. Methods S. pneumoniae isolates from healthy nasopharyngeal carriers less than 2 years old, obtained in a multicentric cross-sectional study conducted in various Peruvian hospitals and health centers from 2007 to 2009, were analyzed. Using Clinical and Laboratory Standards Institute (CLSI) breakpoints, the correlation between the zones of inhibition of the ODD test and the MICs of penicillin and ceftriaxone was determined. Results Of the 571 S. pneumoniae isolates, 314 (55%) showed resistance to penicillin (MIC ≥ 0.12 µg/mL) and 124 (21.7%) showed resistance to ceftriaxone (MIC ≥ 1 µg/mL). Comparison of the ODD test zones of inhibition and the penicillin MICs, using the CLSI meningeal breakpoints, showed good correlation (Cohen's kappa coefficient = 0.8239). Conclusions There was good correlation between ODD zones of inhibition and penicillin meningeal breakpoints but weak correlation between the ODD results and non-meningeal breakpoints for both penicillin and ceftriaxone. Therefore, the ODD test appears to be a useful tool for predicting penicillin resistance in cases of meningeal strains of S. pneumoniae, particularly in low- and middle- income countries, where MIC determination is not routinely available.

  18. The evolving landscape of HIV drug resistance diagnostics for expanding testing in resource-limited settings.

    PubMed

    Inzaule, Seth C; Hamers, Raph L; Paredes, Roger; Yang, Chunfu; Schuurman, Rob; Rinke de Wit, Tobias F

    2017-02-09

    Global scale-up of antiretroviral treatment (ART) has dramatically changed the prospects of HIV/AIDS disease rendering life-long chronic care and treatment a reality for millions of HIV-infected patients. Affordable technologies to monitor ART are needed to ensure long-term durability of limited available drug regimens. HIV drug resistance tests can complement existing strategies in optimizing clinical decision-making for patients with treatment failure, in addition to facilitating population-based surveillance of HIV drug resistance. This review assesses the current landscape of HIV drug resistance technologies and discuss the strengths and limitations of existing assays available for expanding testing in resource limited settings (RLS). These include sequencing-based assays (Sanger sequencing assays and next-generation sequencing), point mutation assays and genotype-free data-based prediction systems. The Sanger assays are currently considered gold standard genotyping technology, though available at a limited number of RLS reference and regional laboratories, but high capital and test cost have limited their wide expansion. The point mutation assays present opportunities for simplified laboratory assays, but HIV genetic variability, extensive codon redundancy at or near the mutation target sites with limited multiplexing capability have restricted their utility. Next-generation sequencing (despite high cost) may have potential to reduce the testing cost significantly through multiplexing in high-throughput facilities, although the level of bioinformatics expertise required for data analysis is currently still complex and expensive and lacks standardization. Web-based genotype-free prediction systems may provide enhanced ART decision-making without the need for laboratory testing, but require further clinical field evaluation and implementation science research in resource-limited settings.

  19. Wear Resistance and Wear Mechanism of a Hot Dip Aluminized Steel in Sliding Wear Test

    NASA Astrophysics Data System (ADS)

    Xue, Zhiyong; Hao, Xiaoyang; Huang, Yao; Gu, Lingyun; Ren, Yu; Zheng, Ruipeng

    2016-12-01

    Sliding wear experiments were conducted on a hot dip aluminized steel to investigate its wear resistance and wear mechanism. The wear tests were also carried out on a hot dip galvanized steel and the base material (steel Q345) as a comparison. Results show that the wear resistance and hardness of the hot dip aluminized steel are significantly higher than that of the hot dip galvanized steel and the steel Q345 at room temperature. The better wear resistance of the hot dip aluminized steel attributes mainly to the formation of a transition layer containing abundant Fe-Al intermetallic compounds and the transformation of wear-resisting oxides during the friction process. The main phase in the transition layer is Fe2Al5. The thickness of the transition layer is about 90-120 μm. When the wear load increases from 3 N to 19 N, the wear type of the aluminized layer transform from adhesive wear (3 N) into abrasive wear (7 N) and finally into slight wear mixed with oxidation (higher than 11 N).

  20. Deep Resistivity Structure of Rainier Mesa-Shoshone Mountain, Nevada Test Site, Nevada

    SciTech Connect

    Theodore H. Asch; Brian D. Rodriguez; Jay A. Sampson; Jackie M. Williams; Maryla Deszcz-Pan

    2006-12-12

    The U. S. Department of Energy (DOE) and the National Nuclear Security Administration (NNSA) at their Nevada Site Office (NSO) are addressing groundwater contamination resulting from historical underground nuclear testing through the Environmental Management (EM) program and, in particular, the Underground Test Area (UGTA) project. During 2005, the U.S. Geological Survey (USGS), funded by the DOE and NNSA-NSO, collected and processed data from twenty-six Magnetotelluric (MT) and Audio-Magnetotelluric (AMT) sites at the Nevada Test Site. Data stations were located in and near Rainier Mesa and Shoshone Mountain to assist in characterizing the pre-Tertiary geology in those areas. These new stations extend to the west the hydrogeologic study that was conducted in Yucca Flat in 2003. This work has helped to refine the character, thickness, and lateral extent of pre Tertiary confining units. In particular, a major goal has been to define the upper clastic confining unit (UCCU – late Devonian to Mississippian-age siliciclastic rocks assigned to the Eleana Formation and Chainman Shale(Bechtel Nevada, 2006)) in the Yucca Flat area and west towards Shoshone Mountain in the south, east of Buckboard Mesa, and onto Rainier Mesa in the north. The Nevada Test Site magnetotelluric data interpretation presented in this report includes the results of detailed two-dimensional (2 D) resistivity modeling for each profile (including alternative interpretations) and gross inferences on the three dimensional (3 D) character of the geology within the region. The character, thickness, and lateral extent of the Chainman Shale and Eleana Formation that comprise the Upper Clastic Confining Unit (UCCU) are generally characterized in the upper 5 km. The interpretation is not well determined where conductive TCU overlies conductive Chainman Shale, where resistive Eleana Formation overlies resistive LCA units, or where resistive VTA rock overlies units of the Eleana Formation. The nature of the

  1. Investigation on oblique shock wave control by arc discharge plasma in supersonic airflow

    NASA Astrophysics Data System (ADS)

    Wang, Jian; Li, Yinghong; Xing, Fei

    2009-10-01

    Wedge oblique shock wave control by arc discharge plasma in supersonic airflow was investigated theoretically, experimentally, and numerically in this paper. Using thermal choking model, the change in oblique shock wave was deduced, which refer that the start point of shock wave shifts upstream, the shock wave angle decreases, and its intensity weakens. Then the theoretical results were validated experimentally in a Mach 2.2 wind tunnel. On the test conditions of arc discharge power of ˜1 kW and arc plasma temperature of ˜3000 K, schlieren photography and gas pressure measurements indicated that the start point of shock wave shifted upstream of ˜4 mm, the shock wave angle decreased 8.6%, and its intensity weakened 8.8%. The deduced theoretical results match the test results qualitatively, so thermal mechanism and thermal choking model are rational to explain the problem of oblique shock wave control by arc discharge plasma. Finally, numerical simulation was developed. Based on thermal mechanism, the arc discharge plasma was simplified as a thermal source term that added to the Navier-Stokes equations. The simulation results of the change in oblique shock wave were consistent with the test results, so the thermal mechanism indeed dominates the oblique shock wave control process.

  2. Investigation on oblique shock wave control by arc discharge plasma in supersonic airflow

    SciTech Connect

    Wang Jian; Li Yinghong; Xing Fei

    2009-10-01

    Wedge oblique shock wave control by arc discharge plasma in supersonic airflow was investigated theoretically, experimentally, and numerically in this paper. Using thermal choking model, the change in oblique shock wave was deduced, which refer that the start point of shock wave shifts upstream, the shock wave angle decreases, and its intensity weakens. Then the theoretical results were validated experimentally in a Mach 2.2 wind tunnel. On the test conditions of arc discharge power of approx1 kW and arc plasma temperature of approx3000 K, schlieren photography and gas pressure measurements indicated that the start point of shock wave shifted upstream of approx4 mm, the shock wave angle decreased 8.6%, and its intensity weakened 8.8%. The deduced theoretical results match the test results qualitatively, so thermal mechanism and thermal choking model are rational to explain the problem of oblique shock wave control by arc discharge plasma. Finally, numerical simulation was developed. Based on thermal mechanism, the arc discharge plasma was simplified as a thermal source term that added to the Navier-Stokes equations. The simulation results of the change in oblique shock wave were consistent with the test results, so the thermal mechanism indeed dominates the oblique shock wave control process.

  3. Creation of an idealized nasopharynx geometry for accurate computational fluid dynamics simulations of nasal airflow in patient-specific models lacking the nasopharynx anatomy.

    PubMed

    A T Borojeni, Azadeh; Frank-Ito, Dennis O; Kimbell, Julia S; Rhee, John S; Garcia, Guilherme J M

    2016-08-15

    Virtual surgery planning based on computational fluid dynamics (CFD) simulations has the potential to improve surgical outcomes for nasal airway obstruction patients, but the benefits of virtual surgery planning must outweigh the risks of radiation exposure. Cone beam computed tomography (CT) scans represent an attractive imaging modality for virtual surgery planning due to lower costs and lower radiation exposures compared with conventional CT scans. However, to minimize the radiation exposure, the cone beam CT sinusitis protocol sometimes images only the nasal cavity, excluding the nasopharynx. The goal of this study was to develop an idealized nasopharynx geometry for accurate representation of outlet boundary conditions when the nasopharynx geometry is unavailable. Anatomically accurate models of the nasopharynx created from 30 CT scans were intersected with planes rotated at different angles to obtain an average geometry. Cross sections of the idealized nasopharynx were approximated as ellipses with cross-sectional areas and aspect ratios equal to the average in the actual patient-specific models. CFD simulations were performed to investigate whether nasal airflow patterns were affected when the CT-based nasopharynx was replaced by the idealized nasopharynx in 10 nasal airway obstruction patients. Despite the simple form of the idealized geometry, all biophysical variables (nasal resistance, airflow rate, and heat fluxes) were very similar in the idealized vs patient-specific models. The results confirmed the expectation that the nasopharynx geometry has a minimal effect in the nasal airflow patterns during inspiration. The idealized nasopharynx geometry will be useful in future CFD studies of nasal airflow based on medical images that exclude the nasopharynx.

  4. 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...

  5. 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

  6. 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.

  7. [Laboratory practices: diagnostics and antibiotics resistance testing of Neisseria gonorrhoeae in Germany].

    PubMed

    Loenenbach, Anna; Dudareva-Vizule, S; Buder, S; Sailer, A; Kohl, P K; Bremer, V

    2015-08-01

    Recent years have seen a world-wide increase in antimicrobial resistance (AMR) in cases of infection with Neisseria gonorrhoeae (NG). NG infection is not notifiable in Germany and there is a lack of information available about the spread and AMR of NG infections. The objective of the study was to provide information on diagnostic methods and AMR testing in cases of NG infections in German laboratories. A cross-sectional survey was undertaken in Germany between June and August 2013 using an online questionnaire. Laboratories performing NG diagnostics were identified and described with regard to the diagnostic methods used, the number of tests performed, the antibiotics tested and the AMR observed, in addition to general laboratory information. In total, 188 of the 521 participating laboratories performed NG diagnostics; these were included in the further statistical analysis. 92.6 % of the 188 laboratories performed culture. A median of 60 (IQR 15-270) samples per quarter (SPQ) were tested, with an overall positivity rate of 4.1 and 6.9 % among men. Most (82.1 %) of the 151 laboratories performing NG culture tested for AMR as well. The most frequently tested antibiotics were ciprofloxacin (94.8 %), penicillin (93.1 %), doxycycline (70.0 %) and ceftriaxone (67.2 %). The most frequently observed AMR ever were those against ciprofloxacin (87.1 %), penicillin (78.3 %), doxycycline (56.6 %) and azithromycin (35.1 %; all percentages refer to laboratories). The laboratories used different standards regarding susceptibility criteria. The emergence and spread of AMR shows that it is crucial to assess and monitor the scope and trends of multidrug-resistant gonorrhea. The data collected on diagnostic methods and AMR testing in cases of NG infections in German laboratories constitute an important basis for future monitoring.

  8. Airflow obstruction: is it asthma or is it COPD?

    PubMed Central

    Rogliani, Paola; Ora, Josuel; Puxeddu, Ermanno; Cazzola, Mario

    2016-01-01

    Despite the availability of guideline recommendations, diagnostic confusion between COPD and asthma appears common, and often it is very difficult to decide whether the obstruction is caused by asthma or COPD in a patient with airway obstruction. However, there are well-defined features that help in differentiating asthma from COPD in the presence of fixed airflow obstruction. Nonetheless, the presentations of asthma and COPD can converge and mimic each other, making it difficult to give these patients a diagnosis of either condition. The association of asthma and COPD in the same patient has been designated mixed asthma–COPD phenotype or overlap syndrome. However, since the absence of a clear definition and the inclusion of patients with different characteristics under this umbrella term, it may not facilitate treatment decisions, especially in the absence of clinical trials addressing this heterogeneous population. We are realizing that neither asthma nor COPD are single diseases, but rather syndromes consisting of several endotypes and phenotypes, consequently comprising a spectrum of diseases that must be recognized and adequately treated with targeted therapy. Therefore, we must treat patients by personalizing therapy on the basis of those treatable traits present in each subject. PMID:27942210

  9. Factors affecting distribution of airflow in a human tracheobronchial cast.

    PubMed

    Cohen, B S; Sussman, R G; Lippmann, M

    1993-09-01

    Air velocity was measured at end airways of hollow replicate casts of the human tracheobronchial tree in order to determine the flow distribution within casts extending to 3 mm diameter airways. Measurements were made by hot-wire anemometry for constant inspiratory flow rates of 7.5, 15, 30 and 60 L.min-1. Average flow distribution among the lung lobes was as follows: right upper, 18.5%; right middle, 9.2%; right lower, 32.3%; left upper, 15.7%; and left lower, 24.3%. An empirical model derived from the experimental flow distribution data demonstrated the effect of various morphometric parameters of the hollow cast on the distribution of airflow. Airway cross-sectional area, branching angle and total path-length were found to have the greatest influence. As the tracheal flow rate decreased from 60 to 7.5 L.min-1, the influence of branching angle was reduced, while total path-length became more influential. These results provide evidence for the transition of flow regimes within the TB tree within normal physiological flow ranges.

  10. Chronic airflow limitation in developing countries: burden and priorities.

    PubMed

    Aït-Khaled, Nadia; Enarson, Donald A; Ottmani, Salah; El Sony, Asma; Eltigani, Mai; Sepulveda, Ricardo

    2007-01-01

    Respiratory disease has never received priority in relation to its impact on health. Estimated DALYs lost in 2002 were 12% globally (similar for industrialized and developing countries). Chronic airflow limitation (due mainly to asthma and COPD) alone affects more than 100 million persons in the world and the majority of them live in developing countries. International guidelines for management of asthma (GINA) and COPD (GOLD) have been adopted and their cost-effectiveness demonstrated in industrialized countries. As resources are scarce in developing countries, adaptation of these guidelines using only essential drugs is required. It remains for governments to set priorities. To make these choices, a set of criteria have been proposed. It is vital that the results of scientific investigations are presented in these terms to facilitate their use by decision-makers. To respond to this emerging public health problem in developing countries, WHO has developed 2 initiatives: "Practical Approach to Lung Health (PAL)" and the Global Alliance Against Chronic Respiratory Diseases (GARD)", and the International Union Against Tuberculosis and Lung Diseases (The Union) has launched a new initiative to increase affordability of essential asthma drugs for patients in developing countries termed the "Asthma Drug Facility" (ADF), which could facilitate the care of patients living in these parts of the world.

  11. 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.

  12. Nocturnal Oxygen Desaturation Index is Inversely Correlated with Airflow Limitation in Patients with Chronic Obstructive Pulmonary Disease.

    PubMed

    Tamai, Koji; Matsuoka, Hirofumi; Suzuki, Yujiro; Yoshimatsu, Harukazu; Masuya, Daiki; Nakashima, Nariyasu; Okada, Nobuhiko; Oda, Nao; Inoue, Sayaka; Koma, Yasuko; Otsuka, Akiko

    2016-01-01

    The concurrent diagnosis of chronic obstructive pulmonary disease (COPD) and sleep apnoea-hypopnoea syndrome (SAHS) (overlap syndrome), can contribute to worsening respiratory symptoms, but whether the severity of COPD is associated with co-morbid SAHS is unknown. We investigated whether the severity of COPD is associated with the complication of SAHS by examination of nocturnal oximetry as an alternative to polysomnography. Patients with COPD concurrently completed nocturnal oximetry, pulmonary function tests, a COPD assessment test, an Epworth sleepiness scale and a hospital anxiety and depression scale to evaluate the severity of COPD and possible concurrent presence of SAHS. We retrospectively analysed the data to assess correlation between the oxygen desaturation index (ODI) and each clinical variables and evaluated the predictors of ODI ≥ 15. This study included 103 patients (91 males, 88%) with a mean age of 72 ± 8 years and body mass index of 22 ± 3 kg/m(2). ODI was positively correlated with FEV1, FEV1/FVC and FEV1% predicted, which meant that ODI was inversely correlated with airflow limitation. Univariate logistic regression analysis revealed that FEV1% predicted and FEV1/FVC were predictors of ODI ≥ 15. ODI is inversely correlated with airflow limitation and milder COPD patients may have co-morbid SAHS.

  13. Effect of air-flow rate and turning frequency on bio-drying of dewatered sludge.

    PubMed

    Zhao, Ling; Gu, Wei-Mei; He, Pin-Jing; Shao, Li-Ming

    2010-12-01

    Sludge bio-drying is an approach for biomass energy utilization, in which sludge is dried by means of the heat generated by aerobic degradation of its organic substances. The study aimed at investigating the interactive influence of air-flow rate and turning frequency on water removal and biomass energy utilization. Results showed that a higher air-flow rate (0.0909m(3)h(-1)kg(-1)) led to lower temperature than did the lower one (0.0455m(3)h(-1)kg(-1)) by 17.0% and 13.7% under turning per two days and four days. With the higher air-flow rate and lower turning frequency, temperature cumulation was almost similar to that with the lower air-flow rate and higher turning frequency. The doubled air-flow rate improved the total water removal ratio by 2.86% (19.5gkg(-1) initial water) and 11.5% (75.0gkg(-1) initial water) with turning per two days and four days respectively, indicating that there was no remarkable advantage for water removal with high air-flow rate, especially with high turning frequency. The heat used for evaporation was 60.6-72.6% of the total heat consumption (34,400-45,400kJ). The higher air-flow rate enhanced volatile solids (VS) degradation thus improving heat generation by 1.95% (800kJ) and 8.96% (3200kJ) with turning per two days and four days. With the higher air-flow rate, heat consumed by sensible heat of inlet air and heat utilization efficiency for evaporation was higher than the lower one. With the higher turning frequency, sensible heat of materials and heat consumed by turning was higher than lower one.

  14. Effects of airflow on body temperatures and sleep stages in a warm humid climate

    NASA Astrophysics Data System (ADS)

    Tsuzuki, Kazuyo; Okamoto-Mizuno, Kazue; Mizuno, Koh; Iwaki, Tatsuya

    2008-03-01

    Airflow is an effective way to increase heat loss—an ongoing process during sleep and wakefulness in daily life. However, it is unclear whether airflow stimulates cutaneous sensation and disturbs sleep or reduces the heat load and facilitates sleep. In this study, 17 male subjects wearing short pyjamas slept on a bed with a cotton blanket under two of the following conditions: (1) air temperature (Ta) 26°C, relative humidity (RH) 50%, and air velocity (V) 0.2 m s-1; (2) Ta 32°C, RH 80%, V 1.7 m s-1; (3) Ta 32°C; RH 80%, V 0.2 m s-1 (hereafter referred to as 26/50, 32/80 with airflow, and 32/80 with still air, respectively). Electroencephalograms, electrooculograms, and mental electromyograms were obtained for all subjects. Rectal (Tre) and skin (Ts) temperatures were recorded continuously during the sleep session, and body-mass was measured before and after the sleep session. No significant differences were observed in the duration of sleep stages between subjects under the 26/50 and 32/80 with airflow conditions; however, the total duration of wakefulness decreased significantly in subjects under the 32/80 with airflow condition compared to that in subjects under the 32/80 with still air condition ( P < 0.05). Tre, Tsk, Ts, and body-mass loss under the 32/80 with airflow condition were significantly higher compared to those under the 26/50 condition, and significantly lower than those under the 32/80 with still air condition ( P < 0.05). An alleviated heat load due to increased airflow was considered to exist between the 32/80 with still air and the 26/50 conditions. Airflow reduces the duration of wakefulness by decreasing Tre, Tsk, Ts, and body-mass loss in a warm humid condition.

  15. Bioinspired carbon nanotube fuzzy fiber hair sensor for air-flow detection.

    PubMed

    Maschmann, Matthew R; Ehlert, Gregory J; Dickinson, Benjamin T; Phillips, David M; Ray, Cody W; Reich, Greg W; Baur, Jeffery W

    2014-05-28

    Artificial hair sensors consisting of a piezoresistive carbon-nanotube-coated glass fiber embedded in a microcapillary are assembled and characterized. Individual sensors resemble a hair plug that may be integrated in a wide range of host materials. The sensors demonstrate an air-flow detection threshold of less than 1 m/s with a piezoresistive sensitivity of 1.3% per m/s air-flow change.

  16. 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.

  17. Testing and Selection of Fire-Resistant Materials for Spacecraft Use

    NASA Technical Reports Server (NTRS)

    Friedman, Robert; Jackson, Brian; Olson, Sandra

    2000-01-01

    Spacecraft fire-safety strategy emphasizes prevention, mostly through the selection of onboard items classified accord- ing to their fire resistance. The principal NASA acceptance tests described in this paper assess the flammability of materials and components under "worst-case" normal-gravity conditions of upward flame spread in controlled-oxygen atmospheres. Tests conducted on the ground, however, cannot duplicate the unique fire characteristics in the nonbuoyant low-gravity environment of orbiting spacecraft. Research shows that flammability an fire-spread rates in low gravity are sensitive to forced convection (ventilation flows) and atmospheric-oxygen concentration. These research results are helping to define new material-screening test methods that will better evaluate material performance in spacecraft.

  18. 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.

  19. Reliability of high-content disks and modified broth dilution tests for detecting staphylococcal resistance to the penicillinase-resistant penicillins.

    PubMed Central

    Barry, A L; Jones, R N

    1987-01-01

    In vitro susceptibility tests were performed with 271 isolates of Staphylococcus species (204 Staphylococcus aureus), including 110 strains resistant to the penicillinase-resistant penicillins. Disks containing 5 or 10 micrograms of methicillin, 1 or 4 micrograms of oxacillin, and 1 or 4 micrograms of nafcillin were evaluated. After a full 24 h of incubation at 35 degrees C, tests with 1-microgram oxacillin disks provided optimal results. Use of the more potent oxacillin, nafcillin, or methicillin disks only increased the number of false-susceptible test results. For broth microdilution tests, 2% NaCl should be added to cation-supplemented Mueller-Hinton broth, and MICs should be recorded after a full 24 h at 35 degrees C. Microdilution tests with oxacillin in broth with 2% NaCl were more reliable than similar tests with methicillin. PMID:3499451

  20. NASA Flight Tests Explore Supersonic Laminar Flow

    NASA Video Gallery

    In partnership with Aerion Corporation of Reno, Nevada, NASA's Dryden Flight Research Center’s tested supersonic airflow over a small experimental airfoil design on its F-15B Test Bed aircraft du...

  1. 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

  2. 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.

  3. High-Frequency Testing of Composite Fan Vanes With Erosion-Resistant Coating Conducted

    NASA Technical Reports Server (NTRS)

    Bowman, Cheryl L.; Sutter, James K.; Naik, Subhash; Otten, Kim D.; Perusek, Gail P.

    2003-01-01

    The mechanical integrity of hard, erosion-resistant coatings were tested using the Structural Dynamics Laboratory at the NASA Glenn Research Center. Under the guidance of Structural Mechanics and Dynamics Branch personnel, fixturing and test procedures were developed at Glenn to simulate engine vibratory conditions on coated polymer-matrix- composite bypass vanes using a slip table in the Structural Dynamics Laboratory. Results from the high-frequency mechanical bench testing, along with concurrent erosion testing of coupons and vanes, provided sufficient confidence to engine-endurance test similarly coated vane segments. The knowledge gained from this program will be applied to the development of oxidation- and erosion-resistant coatings for polymer matrix composite blades and vanes in future advanced turbine engines. Fan bypass vanes from the AE3007 (Rolls Royce America, Indianapolis, IN) gas turbine engine were coated by Engelhard (Windsor, CT) with compliant bond coatings and hard ceramic coatings. The coatings were developed collaboratively by Glenn and Allison Advanced Development Corporation (AADC)/Rolls Royce America through research sponsored by the High-Temperature Engine Materials Technology Project (HITEMP) and the Higher Operating Temperature Propulsion Components (HOTPC) project. High-cycle fatigue was performed through high-frequency vibratory testing on a shaker table. Vane resonant frequency modes were surveyed from 50 to 3000 Hz at input loads from 1g to 55g on both uncoated production vanes and vanes with the erosion-resistant coating. Vanes were instrumented with both lightweight accelerometers and strain gauges to establish resonance, mode shape, and strain amplitudes. Two high-frequency dwell conditions were chosen to excite two strain levels: one approaching the vane's maximum allowable design strain and another near the expected maximum strain during engine operation. Six specimens were tested per dwell condition. Pretest and posttest

  4. Airflow and particle deposition simulations in health and emphysema: from in vivo to in silico animal experiments.

    PubMed

    Oakes, Jessica M; Marsden, Alison L; Grandmont, Celine; Shadden, Shawn C; Darquenne, Chantal; Vignon-Clementel, Irene E

    2014-04-01

    Image-based in silico modeling tools provide detailed velocity and particle deposition data. However, care must be taken when prescribing boundary conditions to model lung physiology in health or disease, such as in emphysema. In this study, the respiratory resistance and compliance were obtained by solving an inverse problem; a 0D global model based on healthy and emphysematous rat experimental data. Multi-scale CFD simulations were performed by solving the 3D Navier-Stokes equations in an MRI-derived rat geometry coupled to a 0D model. Particles with 0.95 μm diameter were tracked and their distribution in the lung was assessed. Seven 3D-0D simulations were performed: healthy, homogeneous, and five heterogeneous emphysema cases. Compliance (C) was significantly higher (p = 0.04) in the emphysematous rats (C = 0.37 ± 0.14 cm(3)/cmH2O) compared to the healthy rats (C = 0.25 ± 0.04 cm(3)/cmH2O), while the resistance remained unchanged (p = 0.83). There were increases in airflow, particle deposition in the 3D model, and particle delivery to the diseased regions for the heterogeneous cases compared to the homogeneous cases. The results highlight the importance of multi-scale numerical simulations to study airflow and particle distribution in healthy and diseased lungs. The effect of particle size and gravity were studied. Once available, these in silico predictions may be compared to experimental deposition data.

  5. 42 CFR 84.192 - Cartridges in parallel; resistance requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Cartridges in parallel; resistance requirements. 84... Chemical Cartridge Respirators § 84.192 Cartridges in parallel; resistance requirements. Where two or more cartridges are used in parallel, their resistance to airflow shall be essentially equal....

  6. 42 CFR 84.192 - Cartridges in parallel; resistance requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Cartridges in parallel; resistance requirements. 84... Chemical Cartridge Respirators § 84.192 Cartridges in parallel; resistance requirements. Where two or more cartridges are used in parallel, their resistance to airflow shall be essentially equal....

  7. 42 CFR 84.192 - Cartridges in parallel; resistance requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Cartridges in parallel; resistance requirements. 84... Chemical Cartridge Respirators § 84.192 Cartridges in parallel; resistance requirements. Where two or more cartridges are used in parallel, their resistance to airflow shall be essentially equal....

  8. 42 CFR 84.192 - Cartridges in parallel; resistance requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Cartridges in parallel; resistance requirements. 84... Chemical Cartridge Respirators § 84.192 Cartridges in parallel; resistance requirements. Where two or more cartridges are used in parallel, their resistance to airflow shall be essentially equal....

  9. 42 CFR 84.192 - Cartridges in parallel; resistance requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Cartridges in parallel; resistance requirements. 84... Chemical Cartridge Respirators § 84.192 Cartridges in parallel; resistance requirements. Where two or more cartridges are used in parallel, their resistance to airflow shall be essentially equal....

  10. Reliability of Strength Testing using the Advanced Resistive Exercise Device and Free Weights

    NASA Technical Reports Server (NTRS)

    English, Kirk L.; Loehr, James A.; Laughlin, Mitzi A.; Lee, Stuart M. C.; Hagan, R. Donald

    2008-01-01

    The Advanced Resistive Exercise Device (ARED) was developed for use on the International Space Station as a countermeasure against muscle atrophy and decreased strength. This investigation examined the reliability of one-repetition maximum (1RM) strength testing using ARED and traditional free weight (FW) exercise. Methods: Six males (180.8 +/- 4.3 cm, 83.6 +/- 6.4 kg, 36 +/- 8 y, mean +/- SD) who had not engaged in resistive exercise for at least six months volunteered to participate in this project. Subjects completed four 1RM testing sessions each for FW and ARED (eight total sessions) using a balanced, randomized, crossover design. All testing using one device was completed before progressing to the other. During each session, 1RM was measured for the squat, heel raise, and deadlift exercises. Generalizability (G) and intraclass correlation coefficients (ICC) were calculated for each exercise on each device and were used to predict the number of sessions needed to obtain a reliable 1RM measurement (G . 0.90). Interclass reliability coefficients and Pearson's correlation coefficients (R) also were calculated for the highest 1RM value (1RM9sub peak)) obtained for each exercise on each device to quantify 1RM relationships between devices.

  11. Electrical Resistivity and Seismic Surveys at the Nevada Test Site, Nevada, April 2007

    USGS Publications Warehouse

    Haines, Seth S.; Burton, Bethany L.; Sweetkind, Donald S.; Asch, Theodore H.

    2008-01-01

    In April 2007, the USGS collected direct-current (DC) electrical resistivity data and shear- (S) and compressional- (P) wave seismic data to provide new detail of previously mapped, overlapping fault splays at two administrative areas in the Nevada Test Site (NTS). In NTS Area 7, we collected two-dimensional DC resistivity data along a transect crossing the Yucca Fault parallel to, and between, two transects along which resistivity data were collected in a previous study in 2006. In addition, we collected three-dimensional DC resistivity data in a grid that overlies part of the 2007 transect. The DC resistivity data show that the fault has a footwall that is more conductive than the hanging wall and an along-strike progression of the fault in a location where overlapping splays are present. Co-located with the northernmost of the two 2006 DC resistivity transects, we acquired S- and P-wave seismic data for both reflection and refraction processing. The S-wave data are corrupted by large amounts of converted (P-wave) energy likely due to the abundance of fractured caliche in the shallow subsurface. The P-wave data show minimal reflected energy, but they show clear refracted first arrivals. We have inverted these first arrival times to determine P-wave seismic velocity models. The seismic model for the transect in Area 7 shows low velocities extending to the base of the model at the location of the Yucca Fault, as well as low velocities at the eastern end of the transect, in the vicinity of the adjacent crater. These new surveys provide further detail about the geometry of the Yucca Fault in this location where it shows two overlapping splays. We collected P- and S-wave seismic data along a transect in the southern part of NTS Area 2, corresponding with the location of a 2006 DC resistivity transect that targeted a set of small faults identified with field mapping. Again, the S-wave data are difficult to interpret. The P-wave data show clear first arrivals that we

  12. Electrical Resistivity and Seismic Surveys at the Nevada Test Site, Nevada, April 2007

    SciTech Connect

    Seth S. Haines; Bethany L. Burton; Donald S. Sweetkind; Theodore H. Asch

    2009-03-30

    In April 2007, the USGS collected direct-current (DC) electrical resistivity data and shear- (S) and compressional- (P) wave seismic data to provide new detail of previously mapped, overlapping fault splays at two administrative areas in the Nevada Test Site (NTS). In NTS Area 7, we collected two-dimensional DC resistivity data along a transect crossing the Yucca Fault parallel to, and between, two transects along which resistivity data were collected in a previous study in 2006. In addition, we collected three-dimensional DC resistivity data in a grid that overlies part of the 2007 transect. The DC resistivity data show that the fault has a footwall that is more conductive than the hanging wall and an along-strike progression of the fault in a location where overlapping splays are present. Co-located with the northernmost of the two 2006 DC resistivity transects, we acquired S- and P-wave seismic data for both reflection and refraction processing. The S-wave data are corrupted by large amounts of converted (P-wave) energy likely due to the abundance of fractured caliche in the shallow subsurface. The P-wave data show minimal reflected energy, but they show clear refracted first arrivals. We have inverted these first arrival times to determine P-wave seismic velocity models. The seismic model for the transect in Area 7 shows low velocities extending to the base of the model at the location of the Yucca Fault, as well as low velocities at the eastern end of the transect, in the vicinity of the adjacent crater. These new surveys provide further detail about the geometry of the Yucca Fault in this location where it shows two overlapping splays. We collected P- and S-wave seismic data along a transect in the southern part of NTS Area 2, corresponding with the location of a 2006 DC resistivity transect that targeted a set of small faults identified with field mapping. Again, the S-wave data are difficult to interpret. The P-wave data show clear first arrivals that we

  13. A durability test rig and methodology for erosion-resistant blade coatings in turbomachinery

    NASA Astrophysics Data System (ADS)

    Leithead, Sean Gregory

    A durability test rig for erosion-resistant gas turbine engine compressor blade coatings was designed, completed and commissioned. Bare and coated 17-4PH steel V103-profile blades were rotated at up to 11500 rpm and impacted with Garnet sand for 5 hours at an average concentration of 2.51 gm3of air , at a blade leading edge Mach number of 0.50. The rig was determined to be an acceptable first stage axial compressor representation. Two types of 16 microm-thick coatings were tested: Titanium Nitride (TiN) and Chromium-Aluminum-Titanium Nitride (CrAlTiN), both applied using an Arc Physical Vapour Deposition technique at the National Research Council in Ottawa, Canada. A Leithead-Allan-Zhao (LAZ) score was created to compare the durability performance of uncoated and coated blades based on mass-loss and blade dimension changes. The bare blades' LAZ score was set as a benchmark of 1.00. The TiN-coated and CrAlTiN-coated blades obtained LAZ scores of 0.69 and 0.41, respectively. A lower score meant a more erosion-resistant coating. Major modes of blade wear included: trailing edge, leading edge and the rear suction surface. Trailing edge thickness was reduced, the leading edge became blunt, and the rear suction surface was scrubbed by overtip and recirculation zone vortices. It was found that the erosion effects of vortex flow were significant. Erosion damage due to reflected particles was not present due to the low blade solidity of 0.7. The rig is best suited for studying the performance of erosion-resistant coatings after they are proven effective in ASTM standardized testing. Keywords: erosion, compressor, coatings, turbomachinery, erosion rate, blade, experimental, gas turbine engine

  14. Comparison between Mach 2 rarefied airflow modification by an electrical discharge and numerical simulation of airflow modification by surface heating

    NASA Astrophysics Data System (ADS)

    Parisse, J. D.; Léger, L.; Depussay, E.; Lago, V.; Burtschell, Y.

    2009-10-01

    This study is devoted to numerical and experimental investigations about the influence of an electrical discharge over a flat plate immersed in a rarefied Mach 2 airflow. Regarding the experimental work, a negative dc discharge is created by applying a potential difference gap between two spanwise aluminum electrodes flush mounted on the plate. The electrode placed close to the leading edge is connected to the negative dc voltage, the second one is grounded. The influence due to the presence of the electric discharge is investigated with a glass Pitot tube by measuring the pressure proles above the flat plate. These experimental results are compared to the numerical work, where the effect of a surface temperature increase is simulated. Different effects can be attributed to the electrical discharge: the ionization of the gas above the plate with the creation of charged species, the acceleration of the positive charged species, the heat of the gas volume above the flat plate, and the heating of the surface of the flat plate. The Pitot probe measurements have shown a thickening of the boundary layer and the increasing of the angle of the shock wave, and the simulation of the surface temperature increase shows the same effect. These arguments let to think that the heating effect due to the temperature increase in the flat plate is the major one among the other effects mentioned above.

  15. Surgical clothing systems in laminar airflow operating room: a numerical assessment.

    PubMed

    Sadrizadeh, Sasan; Holmberg, Sture

    2014-01-01

    This study compared two different laminar airflow distribution strategies - horizontal and vertical - and investigated the effectiveness of both ventilation systems in terms of reducing the sedimentation and distribution of bacteria-carrying particles. Three different staff clothing systems, which resulted in source strengths of 1.5, 4 and 5 CFU/s per person, were considered. The exploration was conducted numerically using a computational fluid dynamics technique. Active and passive air sampling methods were simulated in addition to recovery tests, and the results were compared. Model validation was performed through comparisons with measurement data from the published literature. The recovery test yielded a value of 8.1 min for the horizontal ventilation scenario and 11.9 min for the vertical ventilation system. Fewer particles were captured by the slit sampler and in sedimentation areas with the horizontal ventilation system. The simulated results revealed that under identical conditions in the examined operating room, the horizontal laminar ventilation system performed better than the vertical option. The internal constellation of lamps, the surgical team and objects could have a serious effect on the movement of infectious particles and therefore on postoperative surgical site infections.

  16. Test and characterization of multigap resistive plate chambers for the EEE project

    NASA Astrophysics Data System (ADS)

    Bossini, E.; EEE Collaboration

    2016-03-01

    The Extreme Energy Events project is based on the deployment of cosmic-ray telescopes in Italian high schools with the active contribution of students and teachers. Each telescope is made by three Multigap Resistive Plate Chambers readout by strips. With around 50 telescopes already built and others under construction, specific systems to test and characterize the chambers are needed. In this article I will present a flexible and software-configurable solution to perform chamber efficiency studies with a set of scintillators and hardware to automatically scan detector strips to identify electrical issues. Both systems can provide accurate information but at the same time they can be easily operated by students.

  17. Antimicrobial Susceptibility Testing, Drug Resistance Mechanisms, and Therapy of Infections with Nontuberculous Mycobacteria

    PubMed Central

    Nash, Kevin A.; Wallace, Richard J.

    2012-01-01

    Summary: Within the past 10 years, treatment and diagnostic guidelines for nontuberculous mycobacteria have been recommended by the American Thoracic Society (ATS) and the Infectious Diseases Society of America (IDSA). Moreover, the Clinical and Laboratory Standards Institute (CLSI) has published and recently (in 2011) updated recommendations including suggested antimicrobial and susceptibility breakpoints. The CLSI has also recommended the broth microdilution method as the gold standard for laboratories performing antimicrobial susceptibility testing of nontuberculous mycobacteria. This article reviews the laboratory, diagnostic, and treatment guidelines together with established and probable drug resistance mechanisms of the nontuberculous mycobacteria. PMID:22763637

  18. Affordable HIV drug-resistance testing for monitoring of antiretroviral therapy in sub-Saharan Africa.

    PubMed

    Inzaule, Seth C; Ondoa, Pascale; Peter, Trevor; Mugyenyi, Peter N; Stevens, Wendy S; de Wit, Tobias F Rinke; Hamers, Raph L

    2016-11-01

    Increased provision of antiretroviral therapy in sub-Saharan Africa has led to a growing number of patients with therapy failure and acquired drug-resistant HIV, driving the demand for more costly further lines of antiretroviral therapy. In conjunction with accelerated access to viral load monitoring, feasible and affordable technologies to detect drug-resistant HIV could help maximise the durability and rational use of available drug regimens. Potential low-cost technologies include in-house Sanger and next-generation sequencing in centralised laboratories, and point mutation assays and genotype-free systems that predict response to antiretroviral therapy at point-of-care. Strengthening of centralised high-throughput laboratories, including efficient systems for sample referral and results delivery, will increase economies-of-scale while reducing costs. Access barriers can be mitigated by standardisation of in-house assays into commercial kits, use of polyvalent instruments, and adopting price-reducing strategies. A stepwise rollout approach should improve feasibility, prioritising WHO-recommended population-based surveillance and management of complex patient categories, such as patients failing protease inhibitor-based antiretroviral therapy. Implementation research, adaptations of existing WHO guidance, and political commitment, will be key to support the appropriate investments and policy changes. In this Personal View, we discuss the potential role of HIV drug resistance testing for population-based surveillance and individual patient management in sub-Saharan Africa. We review the strengths and challenges of promising low-cost technologies and how they can be implemented.

  19. Elevated-temperature fracture resistances of monolithic and composite ceramics using chevron-notched bend tests

    NASA Technical Reports Server (NTRS)

    Ghosh, Asish; Jenkins, Michael G.; Ferber, Mattison K.; Peussa, Jouko; Salem, Jonathan A.

    1992-01-01

    The quasi-static fracture behaviors of monolithic ceramics (SiC, Si3N4, MgAl2O4), self-reinforced monoliths (acicular grained Si3N4, acicular grained mullite), and ceramic matrix composites (SiC whisker/Al2O3 matrix, TiB2 particulate/SiC matrix, SiC fiber/CVI SiC matrix, Al2O3 fiber/CVI SiC matrix) were measured over the temperature range of 20 to 1400 C. The chevron notched, bend bar test geometry was essential for characterizing the elevated temperature fracture resistances of this wide range of quasi-brittle materials during stable crack growth. Fractography revealed the differences in the fracture behavior of the different materials at the various temperatures. The fracture resistances of the self-reinforced monoliths were comparable to those of the composites and the fracture mechanisms were found to be similar at room temperature. However at elevated temperatures the differences of the fracture behavior became apparent where the superior fracture resistance of the self-reinforced monoliths were attributed to the minor amounts of glassy, intergranular phases which were often more abundant in the composites and affected the fracture behavior when softened by elevated temperatures.

  20. Diphtheria toxin resistance in human lymphocytes and lymphoblasts in the in vivo somatic cell mutation test

    SciTech Connect

    Tomkins, D.J.; Wei, L.; Laurie, K.E.

    1985-01-01

    It has been shown that circulating peripheral blood lymphocytes can be used for the enumeration of 6-thioguanine-resistant cells that presumably arise by mutation in vivo. This somatic cell mutation test has been studied in lymphocytes from human populations exposed to known mutagens and/or carcinogens. The sensitivity of the test could be further enhanced by including other gene markers, since there is evidence for locus-specific differences in response to mutagens. Resistance to diphtheria toxin (Dip/sup r/) seemed like a potential marker to incorporate into the test because the mutation acts codominantly, can readily be selected in human diploid fibroblasts and Chinese hamster cells with no evidence for cell density or cross-feeding effects, and can be assayed for in nondividing cells by measuring protein synthesis inhibition. Blood samples were collected from seven individuals, and fresh, cryopreserved, or Epstein-Barr virus (EBV)-transformed lymphocytes were tested for continued DNA synthesis (TH-thymidine, autoradiography) or protein synthesis (TVS-methionine, scintillation counting). Both fresh and cryopreserved lymphocytes, stimulated to divide with phytohemagglutinin (PHA), continued to synthesize DNA in the presence of high doses of diphtheria toxin (DT). Similarly, both dividing (PHA-stimulated) and nondividing fresh lymphocytes carried on significant levels of protein synthesis even 68 hr after exposure to 100 flocculating units (LF)/ml DT. The results suggest that human T and B lymphocytes may not be as sensitive to DT protein synthesis inhibition as human fibroblast and Chinese hamster cells. For this reason, Dip/sup r/ may not be a suitable marker for the somatic cell mutation test.

  1. New in vitro tests to evaluate the resistance level of the cattle tick, Rhipicephalus (Boophilus) microplus, against acaricides

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of the present study was to compare two new in vitro tests designed to evaluate the resistance level of R. microplus with two tests currently recommended by the Food and Agriculture Organization of the United Nations (FAO): one performed on larvae, the Larval Packet Test (LPT) and one ...

  2. An international multicenter study on HIV-1 drug resistance testing by 454 ultra-deep pyrosequencing.

    PubMed

    Simen, Birgitte B; Braverman, Michael S; Abbate, Isabella; Aerssens, Jeroen; Bidet, Yannick; Bouchez, Olivier; Gabriel, Christian; Izopet, Jacques; Kessler, Harald H; Stelzl, Evelyn; Di Giallonardo, Francesca; Schlapbach, Ralph; Radonic, Aleksander; Paredes, Roger; Recordon-Pinson, Patricia; Sakwa, James; St John, Elizabeth P; Schmitz-Agheguian, Gudrun G; Metzner, Karin J; Däumer, Martin P

    2014-08-01

    The detection of mutant spectra within the viral quasispecies is critical for therapeutic management of HIV-1 infections. Routine clinical application of ultrasensitive genotyping requires reproducibility and concordance within and between laboratories. The goal of the study was to evaluate a new protocol on HIV-1 drug resistance testing by 454 ultra-deep pyrosequencing (454-UDS) in an international multicenter study. Sixteen blinded HIV-1 subtype B samples were provided for 454-UDS as both RNA and cDNA with viral titers of 88,600-573,000 HIV-1 RNA copies/ml. Eight overlapping amplicons spanning protease (PR) codons 10-99 and reverse transcriptase (RT) codons 1-251 were generated using molecular barcoded primers. 454-UDS was performed using the 454 Life Sciences/Roche GS FLX platform. PR and RT sequences were analyzed using 454 Life Sciences Amplicon Variant Analyzer (AVA) software. Quantified variation data were analyzed for intra-laboratory reproducibility and inter-laboratory concordance. Routine population sequencing was performed using the ViroSeq HIV-1 genotyping system. Eleven laboratories and the reference laboratory 454 Life Sciences sequenced the HIV-1 sample set. Data presented are derived from seven laboratories and the reference laboratory since severe study protocol execution errors occurred in four laboratories leading to exclusion. The median sequencing depth across all sites was 1364 reads per position (IQR=809-2065). 100% of the ViroSeq-reported mutations were also detected by 454-UDS. Minority HIV-1 drug resistance mutations, defined as HIV-1 drug resistance mutations identified at frequencies of 1-25%, were only detected by 454-UDS. Analysis of 10 preselected majority and minority mutations were consistently found across sites. The analysis of drug-resistance mutations detected between 1 and 10% demonstrated high intra- and inter-laboratory consistency in frequency estimates for both RNA and prepared cDNA samples, indicating robustness of the

  3. Soil resistivity over root area ratio, soil humidity, and bulk density: laboratory tests

    NASA Astrophysics Data System (ADS)

    Guastini, Enrico; Giambastiani, Yamuna; Preti, Federico

    2015-04-01

    Knowledge about root system distribution covers an important role in slope shallow stability stud-ies, as this factor grants an increase in soil geotechnical properties (soil cohesion and friction an-gle) and determines a different underground water circulation. Published studies (Amato et al., 2008 and 2011; Censini et al., 2014) about in situ application of ERT (Electrical Resistivity Tomo-graphy) analysis show how the root presence affects the measurable soil resistivity values, confirm-ing the suitability to investigate the application of such technique, aiming to estimate root density in soil with an indirect and non-invasive method. This study, laboratory-based and led on reconstructed samples in controlled condition, aim to find a correlation between the resistivity variations and the various factors that can affect them (humid-ity, bulk density, presence of foreign bodies, temperature). The tests involved a clay-loam soil (USDA classification) taken from Quaracchi (Florence, Italy), in an experimental fir-wood (Picea abies) owned by the Department of Agricultural, Food and For-estry System, Florence University, a previously chosen site for field ERT applications. The row ma-terial has been dried out in a lab stove, grounded and sieved at 2 mm, and then placed in a lexan box (30 x 20 x 20 cm) without compaction. Inside the sample have been inserted 3 series of 4 iron electrodes, insulated along the shaft and with the conductive end placed at three different depth: 2 cm from surface, in the middle of the sample and in contact with the bottom of the box; resistivity measures are conducted on the three levels using a Syscal R2 with electrodes connected in a dipole-dipole configuration. Root presence is simulated inserting bamboo spits (simple geometry, replicable "R.A.R.") in varying number from 0 to 16 in every area between two contiguous electrodes. The tests are repeated in time, monitoring the natural variations in humidity (evapotranspiration) and bulk

  4. Field and storage testing Bt potatoes for resistance to potato tuberworm (Lepidoptera: Gelichiidae).

    PubMed

    Douches, D S; Pett, W; Santos, F; Coombs, J; Grafius, E; Li, W; Metry, E A; el-Din, T Nasr; Madkour, M

    2004-08-01

    Potato tuberworm, Phthorimaea operculella (Zeller), is the most serious insect pest of potatoes worldwide. The introduction of the Bacillus thuringiensis (Bt) toxin gene through genetic engineering offers host plant resistance for the management of potato tuberworm. We report on the field and storage studies to evaluate Bt-cry5 potato lines for resistance to potato tuberworm in Egypt under natural infestations and their agronomic performance in both Egypt and Michigan. From 1997 to 2001, field experiments were conducted at the International Potato Center (CIP) Research Station, Kafr El-Zyat, Egypt, and/or Agricultural Genetic Engineering Institute (AGERI), Giza, Egypt, to evaluate resistance to tuberworm. A total of 27 Bt-transgenic potato lines from six different Bt constructs were evaluated over a 5-yr period. After harvest and evaluation of the agronomic trials, storage evaluation of potato tuberworm damage was done at the CIP Research Station. The 1997 field trial was the first field test of genetically engineered crops in Egypt. Field tests to assess potato tuberworm resistance in Egypt were able to differentiate between the Bt-transgenic lines and the nontransgenic lines/cultivars in 1999, 2000, and 2001. The Bt-cry5-Spunta lines (Spunta-G2, Spunta-G3, and Spunta-6a3) were the most resistant lines in field with 99-100% of tubers free of damage. In the 2001 storage study, these lines were also over 90% free of tuberworm damage after 3 mo. NYL235-4.13, which combines glandular trichomes with the Bt-cry5/gus fusion construct, also had a high percentage of clean tubers in the field studies. In agronomic field trials in Michigan from 1997 to 2001, the Bt-transgenic lines in most instances performed similar to the nontransgenic line in the agronomic trials; however, in Egypt (1998-1999), the yields were less than one-half of those in Michigan. Expression of the Bt-cry5 gene in the potato tuber and foliage will provide the seed producer and grower a tool in which to

  5. Mobile ultra-clean unidirectional airflow screen reduces air contamination in a simulated setting for intra-vitreal injection.

    PubMed

    Lapid-Gortzak, Ruth; Traversari, Roberto; van der Linden, Jan Willem; Lesnik Oberstein, Sarit Y; Lapid, Oren; Schlingemann, Reinier O

    2017-02-01

    The aim of this study is to determine whether the use of a mobile ultra-clean laminar airflow screen reduces the air-borne particle counts in the setting of a simulated procedure of an intra-vitreal injection. A mobile ultra-clean unidirectional airflow (UDF) screen was tested in a simulated procedure for intra-vitreal injections in a treatment room without mechanical ventilation. One UDF was passed over the instrument tray and the surgical area. The concentration of particles was measured in the background, over the instrument table, and next to the ocular area. The degree of protection was calculated at the instrument table and at the surgical site. Use of the UDF mobile screen reduced the mean particle concentration (particles > 0.3 microns) on the instrument table by a factor of at least 100.000 (p < 0.05), and over the patient's eye by at least a factor of 436 (p < 0.05), which in clinical practice translates into significantly reduced air contamination. Mobile UDF screen reduces the mean particle concentration substantially. The mobile UDF screen may therefore allow for a safer procedural environment for ambulatory care procedures such as intra-vitreal injections in treatment rooms.

  6. 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.

  7. Recent progress and tests of radiation resistant impregnation materials for Nb{sub 3}Sn coils

    SciTech Connect

    Bossert, R.; Krave, S.; Ambrosio, G.; Andreev, N.; Chlachidze, G.; Nobrega, A.; Novitski, I.; Yu, M.; Zlobin, A. V.

    2014-01-27

    Fermilab is collaborating with Lawrence Berkeley National Laboratory (LBNL) and Brookhaven National Laboratory (BNL) (US-LARP collaboration) to develop a large-aperture Nb{sub 3}Sn superconducting quadrupole for the Large Hadron Collider (LHC) luminosity upgrade. An important component of this work is the development of materials that are sufficiently radiation resistant for use in critical areas of the upgrade. This paper describes recent progress in characterization of materials, including the baseline CTD101K epoxy, cyanate ester blends, and Matrimid 5292, a bismaleimide-based system. Structural properties of “ten stacks” of cable impregnated with these materials are tested at room and cryogenic temperatures and compared to the baseline CT-101K. Experience with potting 1 and 2 meter long coils with Matrimid 5292 are described. Test results of a single 1-m coil impregnated with Matrimid 5292 are reported and compared to similar coils impregnated with the traditional epoxy.

  8. Recent progress and tests of radiation resistant impregnation materials for Nb3Sn coils

    NASA Astrophysics Data System (ADS)

    Bossert, R.; Krave, S.; Ambrosio, G.; Andreev, N.; Chlachidze, G.; Nobrega, A.; Novitski, I.; Yu, M.; Zlobin, A. V.

    2014-01-01

    Fermilab is collaborating with Lawrence Berkeley National Laboratory (LBNL) and Brookhaven National Laboratory (BNL) (US-LARP collaboration) to develop a large-aperture Nb3Sn superconducting quadrupole for the Large Hadron Collider (LHC) luminosity upgrade. An important component of this work is the development of materials that are sufficiently radiation resistant for use in critical areas of the upgrade. This paper describes recent progress in characterization of materials, including the baseline CTD101K epoxy, cyanate ester blends, and Matrimid 5292, a bismaleimide-based system. Structural properties of "ten stacks" of cable impregnated with these materials are tested at room and cryogenic temperatures and compared to the baseline CT-101K. Experience with potting 1 and 2 meter long coils with Matrimid 5292 are described. Test results of a single 1-m coil impregnated with Matrimid 5292 are reported and compared to similar coils impregnated with the traditional epoxy.

  9. Results of the International Space Station Interim Resistance Exercise Device Man-in-the-Loop Test

    NASA Technical Reports Server (NTRS)

    Moore, A. D., Jr.; Amonette, W. E.; Bentley, J. R.; Rapley, M. G.; Blazine, K. L.; Loehr, J. A.; Collier, K. R.; Boettcher, C. R.; Skrocki, J. S.; Hohrnann, R. J.

    2004-01-01

    The Interim Resistance Exercise Device (iRED), developed for the International Space Station (ISS), was evaluated using human subjects for a Man-In-The-Loop Test (MILT). Thirty-two human subjects exercised using the iRED in a test that was conducted over a 63-working-day period. The subjects performed the same exercises will be used on board ISS, and the iRED operating constraints that are to be used on ISS were followed. In addition, eight of the subjects were astronauts who volunteered to be in the evaluation in order to become familiar with the iRED and provide a critique of the device. The MILT was scheduled to last for 57,000 exercise repetitions on the iRED. This number of repetitions was agreed to as a number typical of that expected during a 3-person, 17-week ISS Increment. One of the canisters of the iRED failed at the 49,683- repetition mark (87.1% of targeted goal). The remaining canister was operated using the plan for operations if one canister fails during flight (contingency operations). This canister remained functional past the 57,000-repetition mark. This report details the results of the iRED MILT, and lists specific recommendations regarding both operation of the iRED and future resistance exercise device development.

  10. Time-lapse electrical resistivity tomography of a water infiltration test on Johannishus Esker, Sweden

    NASA Astrophysics Data System (ADS)

    Ulusoy, İnan; Dahlin, Torleif; Bergman, Bo

    2015-05-01

    Managed aquifer recharge (MAR) is an efficient way to remove organic matter from raw water and, at the same time, reduce temperature variation. Two MAR sites were constructed by Karlskrona municipality on Johannishus Esker in Sweden. One of these sites, Vång, was monitored for electrical conductivity and electrical resistivity (using electrical resistivity tomography - ERT) during a 9-week tracer infiltration test. The aim of the monitoring was to map the pathways of the infiltrated water, with the overall goal to increase the efficiency of the MAR. ERT proved useful in determining both the nature of the esker formation and the water migration pathways. In Vång, the esker ridge follows a tectonically controlled paleo-valley. The fault/fracture zone in the bedrock along this paleo-valley was mapped. During the tracer test, the infiltrated water was detected in the area close to the infiltration ponds, whereas far-situated observation wells were less affected. For sequential infiltration and recharge periods in MAR, the timing of the well pumping is another important factor. Natural groundwater flow direction was a determinant in the infiltration process, as expected. ERT measurements provide supplementary data for site selection, for monitoring the functionality of the MAR sites, and for revealing the geological, hydrogeological and structural characteristics of the site.

  11. Evaluation of the βLacta test, a rapid test detecting resistance to third-generation cephalosporins in clinical strains of Enterobacteriaceae.

    PubMed

    Renvoisé, Aurélie; Decré, Dominique; Amarsy-Guerle, Rishma; Huang, Te-Din; Jost, Christelle; Podglajen, Isabelle; Raskine, Laurent; Genel, Nathalie; Bogaerts, Pierre; Jarlier, Vincent; Arlet, Guillaume

    2013-12-01

    For decades, third-generation cephalosporins (3GC) have been major drugs used to treat infections due to Enterobacteriaceae; growing resistance to these antibiotics makes the rapid detection of such resistance important. The βLacta test is a chromogenic test developed for detecting 3GC-resistant isolates from cultures on solid media within 15 min. A multicenter prospective study conducted in 5 French and Belgian hospitals evaluated the performance of this test on clinical isolates. Based on antibiotic susceptibility testing, strains resistant or intermediate to cefotaxime or ceftazidime were classified as 3GC resistant, and molecular characterization of this resistance was performed. The rates of 3GC resistance were 13.9% (332/2,387) globally, 9.4% in Escherichia coli (132/1,403), 25.6% in Klebsiella pneumoniae (84/328), 30.3% in species naturally producing inducible AmpC beta-lactamases (109/360), and 5.6% in Klebsiella oxytoca and Citrobacter koseri (7/124). The sensitivities and specificities of the βLacta test were, respectively, 87.7% and 99.6% overall, 96% and 100% for E. coli and K. pneumoniae, and 67.4% and 99.6% for species naturally producing inducible AmpC beta-lactamase. False-negative results were mainly related to 3GC-resistant strains producing AmpC beta-lactamase. Interestingly, the test was positive for all 3GC-resistant extended-spectrum beta-lactamase-producing isolates (n = 241). The positive predictive value was 97% and remained at ≥96% for prevalences of 3GC resistance ranging between 10 and 30%. The negative predictive values were 99% for E. coli and K. pneumoniae and 89% for the species producing inducible AmpC beta-lactamase. In conclusion, the βLacta test was found to be easy to use and efficient for the prediction of resistance to third-generation cephalosporins, particularly in extended-spectrum beta-lactamase-producing strains.

  12. [Antibiotic resistance rates of Helicobacter pylori isolates and the comparison of E-test and fluorescent in situ hybridization methods for the detection of clarithromycin resistant strains].

    PubMed

    Bakir Ozbey, Saliha; Ozakin, Cüneyt; Keskin, Murat

    2009-04-01

    Helicobacter pylori which is one of the commonly seen chronic bacterial infections in the world, has been demonstrated to have a relationship with chronic gastritis, peptic ulcer disease and gastric cancer. Current management of H. pylori infection involves the use of a proton pump inhibitor (PPI) and any two of amoxicillin, clarithromycin and metronidazole in combination. Antibiotic resistance which is in an increasing trend in H. pylori since the recent years, is the main cause of treatment failure. This study was conducted to determine the susceptibility of 31 H. pylori strains to several antibiotics by using E-test method (AB Biodisk, Sweden) and also to detect clarithromycin resistance by fluorescent in situ hybridization (FISH; SeaFAST, Hungary). The strains were isolated from the gastric biopsy specimens of patients who were admitted to Uludağ University Hospital, Bursa, Turkey with dyspeptic complaints. Clarithromycin, amoxycillin, metronidazole, tetracycline and ciprofloxacin resistance rates were as 41.9%, 3.2%, 41.9%, 3.2% and 45.2%, respectively. Resistance to single antibiotic was detected in 32.2% of the isolates whereas multiresistance was seen in 45.2%. For the hybridization process one probe specific for 16S rRNA and labeled with a fluorescein dye and the other probe specific for the mutations in 23S rRNA and labeled with Cy3 stain were used. Green signalling denoted presence of H. pylori in the specimen and red signalling was associated with clarithromycin resistance. All of the isolates yielded green signalling and the 13 isolates found to be resistant to clarithromycin by E-test, gave red signalling. No difference was detected between the two methods in terms of clarithromycin resistance determination. This was a preliminary study reporting the H. pylori resistance rates in our region, however, further larger scale studies are required for obtaining countrywide data.

  13. Genotypic susceptibility testing of Mycobacterium tuberculosis isolates for amikacin and kanamycin resistance by use of a rapid sloppy molecular beacon-based assay identifies more cases of low-level drug resistance than phenotypic Lowenstein-Jensen testing.

    PubMed

    Chakravorty, Soumitesh; Lee, Jong Seok; Cho, Eun Jin; Roh, Sandy S; Smith, Laura E; Lee, Jiim; Kim, Cheon Tae; Via, Laura E; Cho, Sang-Nae; Barry, Clifton E; Alland, David

    2015-01-01

    Resistance to amikacin (AMK) and kanamycin (KAN) in clinical Mycobacterium tuberculosis strains is largely determined by specific mutations in the rrs gene and eis gene promoter. We developed a rapid, multiplexed sloppy molecular beacon (SMB) assay to identify these mutations and then evaluated assay performance on 603 clinical M. tuberculosis DNA samples collected in South Korea. Assay performance was compared to gold-standard phenotypic drug susceptibility tests, including Lowenstein-Jensen (LJ) absolute concentration, mycobacterial growth indicator tubes (MGIT), and TREK Sensititre MycoTB MIC plate (MycoTB) methods. Target amplicons were also tested for mutations by Sanger sequencing. The SMB assay correctly detected 115/116 mutant and mixed sequences and 487/487 wild-type sequences (sensitivity and specificity of 99.1 and 100%, respectively). Using the LJ method as the reference, sensitivity and specificity for AMK resistance were 92.2% and 100%, respectively, and sensitivity and specificity for KAN resistance were 87.7% and 95.6%, respectively. Mutations in the rrs gene were unequivocally associated with high-level cross-resistance to AMK and KAN in all three conventional drug susceptibility testing methods. However, eis promoter mutations were associated with KAN resistance using the MGIT or MycoTB methods but not the LJ method. No testing method associated eis promoter mutations with AMK resistance. Among the discordant samples with AMK and/or KAN resistance but wild-type sequence at the target genes, we discovered four new mutations in the whiB7 5' untranslated region (UTR) in 6/22 samples. All six samples were resistant only to KAN, suggesting the possible role of these whiB7 5' UTR mutations in KAN resistance.

  14. Ventilation Rates and Airflow Pathways in Patient Rooms: A Case Study of Bioaerosol Containment and Removal.

    PubMed

    Mousavi, Ehsan S; Grosskopf, Kevin R

    2015-11-01

    Most studies on the transmission of infectious airborne disease have focused on patient room air changes per hour (ACH) and how ACH provides pathogen dilution and removal. The logical but mostly unproven premise is that greater air change rates reduce the concentration of infectious particles and thus, the probability of airborne disease transmission. Recently, a growing body of research suggests pathways between pathogenic source (patient) and control (exhaust) may be the dominant environmental factor. While increases in airborne disease transmission have been associated with ventilation rates below 2 ACH, comparatively less data are available to quantify the benefits of higher air change rates in clinical spaces. As a result, a series of tests were conducted in an actual hospital to observe the containment and removal of respirable aerosols (0.5-10 µm) with respect to ventilation rate and directional airflow in a general patient room, and, an airborne infectious isolation room. Higher ventilation rates were not found to be proportionately effective in reducing aerosol concentrations. Specifically, increasing mechanical ventilation from 2.5 to 5.5 ACH reduced aerosol concentrations only 30% on average. However, particle concentrations were more than 40% higher in pathways between the source and exhaust as was the suspension and migration of larger particles (3-10 µm) throughout the patient room(s). Computational analyses were used to validate the experimental results, and, to further quantify the effect of ventilation rate on exhaust and deposition removal in patient rooms as well as other particle transport phenomena.

  15. A Comparison between Temperature-Controlled Laminar Airflow Device and a Room Air-Cleaner in Reducing Exposure to Particles While Asleep

    PubMed Central

    Spilak, Michal P.; Sigsgaard, Torben; Takai, Hisamitsu; Zhang, Guoqiang

    2016-01-01

    People spend approximately one third of their life sleeping. Exposure to pollutants in the sleep environment often leads to a variety of adverse health effects, such as development and exacerbation of asthma. Avoiding exposure to these pollutants by providing a sufficient air quality in the sleep environment might be a feasible method to alleviate these health symptoms. We performed full-scale laboratory measurements using a thermal manikin positioned on an experimental bed. Three ventilation settings were tested: with no filtration system operated, use of portable air cleaner and use of a temperature-controlled laminar airflow (TLA) device. The first part of the experiment investigated the air-flow characteristics in the breathing zone. In the second part, particle removal efficiency was estimated. Measured in the breathing zone, the room air cleaner demonstrated high turbulence intensity, high velocity and turbulence diffusivity level, with a particle reduction rate of 52% compared to baseline after 30 minutes. The TLA device delivered a laminar airflow to the breathing zone with a reduction rate of 99.5%. During a periodical duvet lifting mimicking a subject’s movement in bed, the particle concentration was significantly lower with the TLA device compared to the room air cleaner. The TLA device provided a barrier which significantly reduced the introduction of airborne particles into the breathing zone. Further studies should be conducted for the understanding of the transport of resuspended particles between the duvet and the laying body. PMID:27898693

  16. Evaluation of disk approximation and single-well broth tests for detection of inducible clindamycin resistance in Streptococcus pneumoniae.

    PubMed

    Jorgensen, James H; McElmeel, M Leticia; Fulcher, Letitia C; McGee, Lesley; Glennen, Anita

    2011-09-01

    This study evaluated an agar disk diffusion D-zone test and an erythromycin-clindamycin (ERY + CLI) single-well broth test for inducible CLI resistance in Streptococcus pneumoniae. The standard CLSI disk approximation test and a single-well combination test incorporating 1 plus 0.5 μg/ml ERY + CLI detected >96% of isolates containing the ermB determinant.

  17. Modelling the Effect of Tree Foliage on Sprayer Airflow in Orchards

    NASA Astrophysics Data System (ADS)

    Melese Endalew, Ayenew; Debaer, Christof; Rutten, Nick; Vercammen, Jef; Delele, Mulugeta Admasu; Ramon, Herman; Nicolaï, Bart M.; Verboven, Pieter

    2011-01-01

    The effect of tree foliage on sprayer airflow through pear trees in a fruit orchard was studied and modelled in detail. A new three-dimensional (3-D) computational fluid dynamics model that integrates the 3-D canopy architecture with a local closure model to simulate the effect of the stem and branches and leaves of trees separately on airflow was developed. The model was validated with field observations made in an experimental orchard (pcfruit, Sint-Truiden, Belgium) in spring and summer 2008 and was used to investigate the airflow from three air-assisted orchard sprayers (Condor V, Duoprop and AirJet quatt). Velocity magnitudes were measured before and behind leafless and fully-leafed pear canopies across the row while the operating sprayers are passing along the row, and were compared with the simulations. The simulation results predicted the measured values well with all the local relative errors within 20%. The effect of foliar density on airflow from the three air assisted sprayers was manifested by changing the magnitude and direction of the sprayers' air velocity behind the canopy, especially at the denser regions of the canopy and by changing the pattern of velocity decay horizontally along the jet. The developed methodology will also allow a thorough investigation of atmospheric airflow in canopy structures.

  18. The fluid dynamics of canine olfaction: unique nasal airflow patterns as an explanation of macrosmia

    PubMed Central

    Craven, Brent A.; Paterson, Eric G.; Settles, Gary S.

    2010-01-01

    The canine nasal cavity contains hundreds of millions of sensory neurons, located in the olfactory epithelium that lines convoluted nasal turbinates recessed in the rear of the nose. Traditional explanations for canine olfactory acuity, which include large sensory organ size and receptor gene repertoire, overlook the fluid dynamics of odorant transport during sniffing. But odorant transport to the sensory part of the nose is the first critical step in olfaction. Here we report new experimental data on canine sniffing and demonstrate allometric scaling of sniff frequency, inspiratory airflow rate and tidal volume with body mass. Next, a computational fluid dynamics simulation of airflow in an anatomically accurate three-dimensional model of the canine nasal cavity, reconstructed from high-resolution magnetic resonance imaging scans, reveals that, during sniffing, spatially separate odour samples are acquired by each nostril that may be used for bilateral stimulus intensity comparison and odour source localization. Inside the nose, the computation shows that a unique nasal airflow pattern develops during sniffing, which is optimized for odorant transport to the olfactory part of the nose. These results contrast sharply with nasal airflow in the human. We propose that mammalian olfactory function and acuity may largely depend on odorant transport by nasal airflow patterns resulting from either the presence of a highly developed olfactory recess (in macrosmats such as the canine) or the lack of one (in microsmats including humans). PMID:20007171

  19. The measurement of exhaled carbon monoxide is influenced by airflow obstruction.

    PubMed

    Togores, B; Bosch, M; Agustí, A G

    2000-01-01

    The concentration of carboxyhaemoglobin (COHb) is often estimated from measurements of carbon monoxide in the exhaled air (COexh). This study investigates whether the presence of airflow obstruction significantly alters the relationship between COexh and COHb. Eighty-one regular smokers were prospectively studied and divided in four groups according to the presence and severity of airflow obstruction (none, mild, moderate, severe). In each subject, the authors measured in this order: 1) arterial blood gases; 2) haemoglobin concentration and COHb (by co-oxymetry); 3) COexh; 4) lung volumes; and 5) forced spirometry. The size of the measurement error (deltaCO) was calculated from the difference between COHb and COexh. Neither the smoking history nor COexh were different in the four groups of subjects studied. In contrast, deltaCO increased in parallel to the degree of airflow obstruction. DeltaCO was >2% (a threshold value normally used in the clinic to separate smokers from nonsmokers) only in patients with severe airflow obstruction. A stepwise multivariate analysis showed that both forced expiratory volume in one second (FEV1) (percentage reference) and COHb contributed significantly (p<0.0001) to predict deltaCO. This study shows that the estimation of carboxyhaemoglobin from exhaled carbon monoxide measurements can be inaccurate in patients with severe airflow obstruction. In these patients, the direct measurement of carboxyhaemoglobin seems advisable in clinical practice.

  20. Effects of airflow on the distribution of filaments in atmospheric AC dielectric barrier discharge

    NASA Astrophysics Data System (ADS)

    Fan, Zhihui; Qi, Haicheng; Liu, Yidi; Yan, Huijie; Ren, Chunsheng

    2016-12-01

    Atmospheric-pressure dielectric barrier discharge (DBD) accompanied by airflow has attracted a significant attention for its extensive applications. In this paper, the effects of airflow on the characteristics of the atmospheric air DBD plasma are experimentally investigated using the DBD reactor excited by a 15 kHz AC power source. In order to study the discharge filaments distribution at different flow rates, transparent conductive indium tin oxide film is used as the upper electrode, and quartz glasses are used as insulated dielectrics. Experiment results prove that the breakdown voltage is decreased and more current pulses with declined amplitudes are produced when the airflow is introduced into the discharge gap. It is confirmed that although the discharge seems to be diffuse in the presence of airflow to the naked eyes, the discharge mode remains filamentary in the intensified charge-coupled device images within a single AC cycle. By acquiring the images with a different exposure time, it can be recognized that the discharge filaments move along the flow field direction with a velocity less than the corresponding flow rate. The movement of discharge filaments is attributed to the motion of the charge induced by the airflow.

  1. Three-dimensional airflow and sediment transport patterns over barchan dunes

    NASA Astrophysics Data System (ADS)

    Smith, Alexander B.; Jackson, Derek W. T.; Cooper, J. Andrew G.

    2017-02-01

    Airflow dynamics and potential sediment transport were measured and modelled across various barchan dune topographies and incident wind conditions. Modification of near surface flow was recorded simultaneously in three dimensions (3D) using dense arrays of high-resolution 3D ultrasonic anemometers. In situ measurements provided rigorous validation and calibration for computational fluid dynamics (CFD) modelling. Measured and modelled results show good agreement between flow velocity, directionality, and turbulence intensity. Modelling of characteristic airflow conditions and surface shear stress beyond the instrument locations, elucidated airflow dynamics across the entire landform surface at an unprecedented level of detail. Emergent turbulent airflow patterns were identified in the form of two counter-rotating vortices that converge at the dune centreline downwind of the dune crest. Integrating a sediment transport function with CFD surface airflow allows for the spatial mapping of flux patterns across the entirety of the dune and interdune surface. On the stoss slope and laterally along the outer barchan arms, there is strong potential sediment flux in response to increased streamwise stress. In lee-side locations, sediment transport remains at 'above threshold' conditions and is redirected in response to complex turbulent vortices identified in the overlying wake zone. The precision of the models allows for the identification of complex flow perturbations and associated surface stresses that prove difficult to measure in the field. CFD in combination with a sediment transport function is demonstrated to be a useful tool in investigating morphodynamics of mobile dune systems.

  2. 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

  3. 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.

  4. Using Computational Fluid Dynamics to examine airflow characteristics in Empty Nose Syndrome

    NASA Astrophysics Data System (ADS)

    Flint, Tim; Esmaily-Moghadam, Mahdi; Thamboo, Andrew; Velasquez, Nathalia; Nayak, Jayakar V.; Sellier, Mathieu; Moin, Parviz

    2016-11-01

    The enigmatic disorder, empty nose syndrome (ENS), presents with a complex subjective symptom profile despite objectively patent nasal airways, and recent reports suggest that surgical augmentation of the nasal airway can improve quality of life and ENS-related complaints. In this study, computational fluid dynamics (CFD) was performed both prior to, and following, inferior turbinate augmentation to model the resultant changes in airflow patterns and better understand the pathophysiology of ENS. An ENS patient with marked reduction in ENS symptoms following turbinate augmentation was identified, and pre- and post-operative CT imaging was collected. A Finite element framework with the variational multiscale method (Esmaily-Moghadam, Comput. Methods Appl. Mech. Engrg. 2015) was used to compute the airflow, temperature, and moisture transport through the nasal cavity. Comparison of the CFD results following corrective surgery showed higher levels of airflow turbulence. Augmentation produced 50%, 25%, and 25% increases in root mean square pressure, wall shear stress, and heat flux respectively. These results provide insight into the changes in nasal airflow characteristics attainable through surgical augmentation, and by extension, how nasal airflow patterns may be distorted in the 'overly patent' airway of ENS patients. Supported by Stanford University CTR and Fulbright New Zealand.

  5. Susceptibility testing of extensively drug-resistant and pre-extensively drug-resistant Mycobacterium tuberculosis against levofloxacin, linezolid, and amoxicillin-clavulanate.

    PubMed

    Ahmed, Imran; Jabeen, Kauser; Inayat, Raunaq; Hasan, Rumina

    2013-06-01

    Pakistan is a high-burden country for tuberculosis (TB). The emergence and increasing incidence of extensively drug-resistant (XDR) TB has been reported in Pakistan. Similarly, the prevalence of multidrug-resistant TB infections with fluoroquinolone resistance (pre-XDR) is also increasing. To treat these infections, local drug susceptibility patterns of alternate antituberculosis agents, including levofloxacin (LVX), linezolid (LZD), and amoxicillin-clavulanate (AMC), is urgently needed. The aim of this study was to determine the susceptibility frequencies of drug-resistant (DR) Mycobacterium tuberculosis against LVX, LZD, and AMC. All susceptibilities were determined on Middlebrook 7H10 agar. A critical concentration was used for LVX (1 μg/ml), whereas MICs were determined for LZD and AMC. M. tuberculosis H37Rv was used as a control strain. A total of 102 M. tuberculosis isolates (XDR, n = 59; pre-XDR, n = 43) were tested. Resistance to LVX was observed in 91.2% (93/102). Using an MIC value of 0.5 μg/ml as a cutoff, resistance to LZD (MIC ≥ 1 μg/ml) was noted in 5.9% (6/102). Although the sensitivity breakpoints are not established for AMC, the MIC values were high (>16 μg/ml) in 97.1% (99/102). Our results demonstrate that LZD may be effective for the treatment of XDR and pre-XDR cases from Pakistan. High resistance rates against LVX in our study suggest the use of this drug with caution for DR-TB cases from this area. Drug susceptibility testing against LVX and AMC may be helpful in complicated and difficult-to-manage cases.

  6. Susceptibility Testing of Extensively Drug-Resistant and Pre-Extensively Drug-Resistant Mycobacterium tuberculosis against Levofloxacin, Linezolid, and Amoxicillin-Clavulanate

    PubMed Central

    Ahmed, Imran; Jabeen, Kauser; Inayat, Raunaq

    2013-01-01

    Pakistan is a high-burden country for tuberculosis (TB). The emergence and increasing incidence of extensively drug-resistant (XDR) TB has been reported in Pakistan. Similarly, the prevalence of multidrug-resistant TB infections with fluoroquinolone resistance (pre-XDR) is also increasing. To treat these infections, local drug susceptibility patterns of alternate antituberculosis agents, including levofloxacin (LVX), linezolid (LZD), and amoxicillin-clavulanate (AMC), is urgently needed. The aim of this study was to determine the susceptibility frequencies of drug-resistant (DR) Mycobacterium tuberculosis against LVX, LZD, and AMC. All susceptibilities were determined on Middlebrook 7H10 agar. A critical concentration was used for LVX (1 μg/ml), whereas MICs were determined for LZD and AMC. M. tuberculosis H37Rv was used as a control strain. A total of 102 M. tuberculosis isolates (XDR, n = 59; pre-XDR, n = 43) were tested. Resistance to LVX was observed in 91.2% (93/102). Using an MIC value of 0.5 μg/ml as a cutoff, resistance to LZD (MIC ≥ 1 μg/ml) was noted in 5.9% (6/102). Although the sensitivity breakpoints are not established for AMC, the MIC values were high (>16 μg/ml) in 97.1% (99/102). Our results demonstrate that LZD may be effective for the treatment of XDR and pre-XDR cases from Pakistan. High resistance rates against LVX in our study suggest the use of this drug with caution for DR-TB cases from this area. Drug susceptibility testing against LVX and AMC may be helpful in complicated and difficult-to-manage cases. PMID:23507286

  7. Second line drug susceptibility testing to inform the treatment of rifampin-resistant tuberculosis: a quantitative perspective.

    PubMed

    Kendall, Emily A; Cohen, Ted; Mitnick, Carole D; Dowdy, David W

    2017-03-01

    Treatment failure and resistance amplification are common among patients with rifampin-resistant tuberculosis (TB). Drug susceptibility testing (DST) for second-line drugs is recommended for these patients, but logistical difficulties have impeded widespread implementation of second-line DST in many settings. To provide a quantitative perspective on the decision to scale up second-line DST, we synthesize literature on the prevalence of second-line drug resistance, the expected clinical and epidemiologic benefits of using second-line DST to ensure that patients with rifampin-resistant TB receive effective regimens, and the costs of implementing (or not implementing) second-line DST for all individuals diagnosed with rifampin-resistant TB. We conclude that, in most settings, second-line DST could substantially improve treatment outcomes for patients with rifampin-resistant TB, reduce transmission of drug-resistant TB, prevent amplification of drug resistance, and be affordable or even cost-saving. Given the large investment made in each patient treated for rifampin-resistant TB, these payoffs would come at relatively small incremental cost. These anticipated benefits likely justify addressing the real challenges faced in implementing second-line DST in most high-burden settings.

  8. Final Report, FY 2001 200 East Vadose Test Site Hanford Washington Electrical Resistance Tomography

    SciTech Connect

    Ramirez, A.; Daily, W.; Binley, A.

    2001-06-30

    This report covers the electrical resistance tomography (ERT) work performed at the Hanford Reservation, 200 East Area Vadose test (Sisson and Lu) site during the period March 23 through May 5,2001. The purposes of the ERT work were to: (1) Compare and contrast the development of the highly concentrated sodium thiosulfate plume (FY 01 work) with the fresh river water plume observed during FY 00. (2) Use the resistance images to infer the dynamics of the plume during two or three of the sodium thio-sulfate releases and during the water ''chaser'' release. (3) Determine the influence of the site's steel casings on the ability to construct reliable ERT images. (4) Determine if the steel casings at the site can be used as long electrodes to provide useful images of at least one release. (5) Develop quantitative estimates of the noise in the data and its effect on reconstructed images. Eleven electrode arrays (nine electrodes arrays available for the FY00 work), each with 15 electrodes, were installed at the site. These were used to perform 3D surveys before, during, and after 3 different spills.

  9. Developing Pairwise Preference-Based Personality Test and Experimental Investigation of Its Resistance to Faking Effect by Item Response Model

    ERIC Educational Resources Information Center

    Usami, Satoshi; Sakamoto, Asami; Naito, Jun; Abe, Yu

    2016-01-01

    Recent years have shown increased awareness of the importance of personality tests in educational, clinical, and occupational settings, and developing faking-resistant personality tests is a very pragmatic issue for achieving more precise measurement. Inspired by Stark (2002) and Stark, Chernyshenko, and Drasgow (2005), we develop a pairwise…

  10. Testing a scale pulsed modulator for an IEC neutron source into a resistive load

    SciTech Connect

    Dale, Gregory E; Wheat, Robert M; Aragonez, Robert

    2009-01-01

    A 1/10th scaled prototype pulse modulator for an Inertial Electrostatic Confinement (IEC) neutron source has been designed and tested at Los Alamos National Laboratory (LANL). The scaled prototype modulator is based on a solid-state Marx architecture and has an output voltage of 13 kV and an output current of 10 A. The modulator has a variable pulse width between 50 {micro}s and 1 ms with < 5% droop at all pulse widths. The modulator operates with a duty factor up to 5% and has a maximum pulse repetition frequency of 1 kHz. The use of a solid-state Marx modulator in this application has several potential benefits. These benefits include variable pulse width and amplitude, inherent switch overcurrent and transient overvoltage protection, and increased efficiency over DC supplies used in this application. Several new features were incorporated into this design including inductorless charging, fully snubberless operation, and stage fusing. The scaled prototype modulator has been tested using a 1 k{Omega} resistive load. Test results are given. Short (50 {micro}s) and long (1 ms) pulses are demonstrated as well as high duty factor operation (1 kHz rep rate at a 50 {micro}s pulse width for a 5% duty factor). Pulse agility of the modulator is demonstrated through turning the individual Marx stages on and off in sequence producing ramp, pyramid, and reverse pyramid waveforms.

  11. Testing the apparent resistance of three dominant plants to chronic drought on the Colorado Plateau

    USGS Publications Warehouse

    Hoover, David L.; Duniway, Michael C.; Belnap, Jayne

    2016-01-01

    Many drylands, including the south-western United States, are projected to become more water-limited as these regions become warmer and drier with climate change. Such chronic drought may push individual species or plant functional types beyond key thresholds leading to reduced growth or even mortality. Indeed, recent observational and experimental evidence from the Colorado Plateau suggests that C3 grasses are the most vulnerable to chronic drought, while C4 grasses and C3 shrubs appear to have greater resistance.The effects of chronic, or press-drought are predicted to begin at the physiological level and translate up to higher hierarchical levels. To date, the drought resistance of C4grasses and C3 shrubs in this region has been only evaluated at the community level and thus we lack information on whether there are sensitivities to drought at lower hierarchical levels. In this study, we tested the apparent drought resistance of three dominant species (Pleuraphis jamesii, a C4 rhizomatous grass; Coleogyne ramosissima, a C3 drought-deciduous shrub; and Ephedra viridis, a C3 evergreen shrub) to an ongoing experimental press-drought (-35% precipitation) by comparing individual-level responses (ecophysiology and growth dynamics) to community-level responses (plant cover).For all three species, we observed consistent responses across all hierarchical levels:P. jamesii was sensitive to drought across all measured variables, while the shrubsC. ramosissima and E. viridis had little to no responses to the experimental press-drought at any given level.Synthesis. Our findings suggest that the apparent drought resistance at higher hierarchical levels, such as cover, may serve as good proxies for lower-level responses. Furthermore, it appears the shrubs are avoiding drought, possibly by utilizing moisture at deeper soil layers, while the grasses are limited to shallower layers and must endure the drought conditions. Give this differential sensitivity to drought, a future

  12. Functional categorization of carbapenemase-mediated resistance by a combined genotyping and two-tiered Modified Hodge Test approach.

    PubMed

    Wong, Marcus H; Li, Yi; Chan, Edward W; Chen, Sheng

    2015-01-01

    The functional relationship between the detection of carbapenemase activity and phenotypic resistance in Gram-negative bacterial pathogens is often ill-defined. To address this issue, we developed a two-tiered Modified Hodge Test approach for carbapenemase detection and typing, in which the use of Pseudomonas aeruginosa strain PAO1 and Escherichia coli as indicator strains conferred two levels of sensitivities to carbapenemases. When applied alongside PCR genotyping tests for existence of known carbapenemase genes in 92 carbapenem resistant clinical isolates, this method is extremely useful in elucidating the relative role by which different enzymes contributed to the prevalent carbapenem-resistance phenotypes. With this study approach, we showed that the proportion of P. aeruginosa and Acinetobacter baumannii strains whose carbapenem resistance phenotypes could at least be partially attributed to carbapenemase were 34 and 89%, respectively. Our data also facilitates detailed functional categorization of carbapenem resistance phenotypes on the basis of the types and activities of detectable carbapenemase produced by the test organism. For example, six A. baumannii isolates harboring the bla OXA-51/23-like gene without detectable enzymatic activities were identified, suggesting that other resistance mechanisms may be involved. On the other hand, there were seven P. aeruginosa strains which produced carbapenemase phenotype without harboring known carbapenemase genes, inferring the existence of some hitherto unknown resistance determinants. Findings in this work therefore provide a comprehensive view on the cellular basis of carbapenem resistance phenotypes in major Gram-negative bacterial species, paving the way for development of novel strategies to reverse the effects of the major resistance mechanisms concerned.

  13. 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.

  14. Microphonic versus end-tidal carbon dioxide nasal airflow detection in neonates with apnea.

    PubMed

    Toubas, P L; Duke, J C; Sekar, K C; McCaffree, M A

    1990-12-01

    Impedance pneumography in combination with expired CO2 monitoring are commonly used techniques for detecting central and obstructive apnea in infants. In this investigation an American Telephone and Telegraph StarSet-1 3000-ohm self-actuating microphone connected to the end of an infant cannula was used to monitor neonatal nasal airflow to detect breaths and apnea. The microphone was placed in a soundproof container to eliminate environmental sound artifacts. Analyses of 100 breaths from five patient samples during active and quiet sleep showed that there was no significant difference between microphone and expired CO2 recording of respiration. The techniques were 98% and 96% sensitive, respectively. Microphonic detection of nasal airflow identified 27 of the 32 episodes of upper airway obstruction (84.2%) registered by end-tidal CO2 recording. Inspiratory and expiratory events could also be well documented. Microphonic recording of nasal airflow is a reliable and inexpensive technique to detect apnea.

  15. Evaluation of susceptibility test breakpoints used to predict mecA-mediated resistance in Staphylococcus pseudintermedius isolated from dogs.

    PubMed

    Bemis, David A; Jones, Rebekah D; Frank, Linda A; Kania, Stephen A

    2009-01-01

    Clinical and Laboratory Standards Institute interpretive breakpoints for in vitro susceptibility tests that predict mecA-mediated oxacillin resistance in Staphylococcus pseudintermedius isolates from animals have been changed twice in the past decade. Moreover, there are no counterpart recommendations for human isolates of S. pseudintermedius. Individual medical and veterinary laboratories variably use interpretive breakpoints identical to those recommended for use with Staphylococcus aureus or identical to those recommended for use with coagulase-negative staphylococci. The purpose of the current study was to examine correlations between oxacillin disk diffusion, oxacillin gradient diffusion, oxacillin microbroth dilution, and cefoxitin disk diffusion tests used to predict mecA-mediated resistance in S. pseudintermedius and to retrospectively estimate, from disk diffusion zone diameter measurements, the prevalence and rate of increase of oxacillin resistance among canine S. pseudintermedius isolates submitted to a veterinary teaching hospital laboratory. Oxacillin disk diffusion zone diameters of or=0.5 microg/ml were highly correlated with detection of mecA in canine S. pseudintermedius isolates by polymerase chain reaction. MecA-mediated resistance among S. pseudintermedius isolates from dogs increased from less than 5% in 2001 to near 30% in 2007. More than 90% of the methicillin-resistant S. pseudintermedius isolates in 2006 and 2007 were also resistant to representatives of >or=4 additional antimicrobial drug classes. Cefoxitin disk diffusion with the resistance breakpoint set at

  16. 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

  17. Characterization of micro-contact resistance between a gold nanocrystalline line and a tungsten electrode probe in interconnect fatigue testing.

    PubMed

    Ling, Xue; Wang, Yusheng; Li, Xide

    2014-10-01

    An electromechanically-coupled micro-contact resistance measurement system is built to mimic the contact process during fatigue testing of nanoscale-thickness interconnects using multiple probe methods. The design combines an optical microscope, high-resolution electronic balance, and micromanipulator-controlled electric probe, and is coupled with electrical measurements to investigate microscale contact physics. Experimental measurements are performed to characterize the contact resistance response of the gold nanocrystalline pad of a 35-nm-thick interconnect under mechanical force applied by a tungsten electrode probe. Location of a stable region for the contact resistance and the critical contact force provides better understanding of micro-contact behavior relative to the effects of the contact force and the nature of the contact surface. Increasing contact temperature leads to reduced contact resistance, softens the pad material, and modifies the contact surface. The stability of both contact resistance and interconnect resistance is studied under increasing contact force. Major fluctuations emerge when the contact force is less than the critical contact force, which shows that temporal contact resistance will affect interconnect resistance measurement accuracy, even when using the four-wire method. This performance is demonstrated experimentally by heating the Au line locally with a laser beam. Finally, the contact resistances are calculated using the LET (Li-Etsion-Talke) model together with combined Holm and Sharvin theory under various contact forces. Good agreement between the results is obtained. This research provides a way to measure change in interconnect line resistance directly under a stable contact resistance regime with a two-wire method that will greatly reduce the experimental costs.

  18. Characterization of micro-contact resistance between a gold nanocrystalline line and a tungsten electrode probe in interconnect fatigue testing

    NASA Astrophysics Data System (ADS)

    Ling, Xue; Wang, Yusheng; Li, Xide

    2014-10-01

    An electromechanically-coupled micro-contact resistance measurement system is built to mimic the contact process during fatigue testing of nanoscale-thickness interconnects using multiple probe methods. The design combines an optical microscope, high-resolution electronic balance, and micromanipulator-controlled electric probe, and is coupled with electrical measurements to investigate microscale contact physics. Experimental measurements are performed to characterize the contact resistance response of the gold nanocrystalline pad of a 35-nm-thick interconnect under mechanical force applied by a tungsten electrode probe. Location of a stable region for the contact resistance and the critical contact force provides better understanding of micro-contact behavior relative to the effects of the contact force and the nature of the contact surface. Increasing contact temperature leads to reduced contact resistance, softens the pad material, and modifies the contact surface. The stability of both contact resistance and interconnect resistance is studied under increasing contact force. Major fluctuations emerge when the contact force is less than the critical contact force, which shows that temporal contact resistance will affect interconnect resistance measurement accuracy, even when using the four-wire method. This performance is demonstrated experimentally by heating the Au line locally with a laser beam. Finally, the contact resistances are calculated using the LET (Li-Etsion-Talke) model together with combined Holm and Sharvin theory under various contact forces. Good agreement between the results is obtained. This research provides a way to measure change in interconnect line resistance directly under a stable contact resistance regime with a two-wire method that will greatly reduce the experimental costs.

  19. Characterization of micro-contact resistance between a gold nanocrystalline line and a tungsten electrode probe in interconnect fatigue testing

    SciTech Connect

    Ling, Xue; Wang, Yusheng; Li, Xide

    2014-10-15

    An electromechanically-coupled micro-contact resistance measurement system is built to mimic the contact process during fatigue testing of nanoscale-thickness interconnects using multiple probe methods. The design combines an optical microscope, high-resolution electronic balance, and micromanipulator-controlled electric probe, and is coupled with electrical measurements to investigate microscale contact physics. Experimental measurements are performed to characterize the contact resistance response of the gold nanocrystalline pad of a 35-nm-thick interconnect under mechanical force applied by a tungsten electrode probe. Location of a stable region for the contact resistance and the critical contact force provides better understanding of micro-contact behavior relative to the effects of the contact force and the nature of the contact surface. Increasing contact temperature leads to reduced contact resistance, softens the pad material, and modifies the contact surface. The stability of both contact resistance and interconnect resistance is studied under increasing contact force. Major fluctuations emerge when the contact force is less than the critical contact force, which shows that temporal contact resistance will affect interconnect resistance measurement accuracy, even when using the four-wire method. This performance is demonstrated experimentally by heating the Au line locally with a laser beam. Finally, the contact resistances are calculated using the LET (Li–Etsion–Talke) model together with combined Holm and Sharvin theory under various contact forces. Good agreement between the results is obtained. This research provides a way to measure change in interconnect line resistance directly under a stable contact resistance regime with a two-wire method that will greatly reduce the experimental costs.

  20. Large-scale test of the natural refuge strategy for delaying insect resistance to transgenic Bt crops.

    PubMed

    Jin, Lin; Zhang, Haonan; Lu, Yanhui; Yang, Yihua; Wu, Kongming; Tabashnik, Bruce E; Wu, Yidong

    2015-02-01

    The 'natural refuge strategy" for delaying insect resistance to transgenic cotton that produces insecticidal proteins from Bacillus thuringiensis (Bt) relies on refuges of host plants other than cotton that do not make Bt toxins. We tested this widely adopted strategy by comparing predictions from modeling with data from a four-year field study of cotton bollworm (Helicoverpa armigera) resistance to transgenic cotton producing Bt toxin Cry1Ac in six provinces of northern China. Bioassay data revealed that the percentage of resistant insects increased from 0.93% in 2010 to 5.5% in 2013. Modeling predicted that the percentage of resistant insects would exceed 98% in 2013 without natural refuges, but would increase to only 1.1% if natural refuges were as effective as non-Bt cotton refuges. Therefore, the results imply that natural refuges delayed resistance, but were not as effective as an equivalent area of non-Bt cotton refuges. The percentage of resistant insects with nonrecessive inheritance of resistance increased from 37% in 2010 to 84% in 2013. Switching to Bt cotton producing two or more toxins and integrating other control tactics could slow further increases in resistance.

  1. Mechanism of isoproturon resistance in Phalaris minor: in silico design, synthesis and testing of some novel herbicides for regaining sensitivity.

    PubMed

    Singh, Durg Vijay; Adeppa, Kuruba; Misra, Krishna

    2012-04-01

    Isoproturon, 3-p-cumenyl-1 dimethylurea was the only herbicide controlling Phalaris minor, a major weed growing in wheat fields till the early 1980s. Since it has acquired resistance against isoproturon, like other substituted urea herbicides, where the identified target site for isoproturon is in the photosynthetic apparatus at D1 protein of Photosystem-II (PS-II). Nucleotide sequence of susceptible and resistant psbA gene of P. minor has been reported to have four point mutations. During the present work D1 protein of both susceptible and resistant biotypes of P Minor has been modeled. Transmembrane segments of amino acids were predicted by comparing with the nearest homolog of bacterial D1 protein. Volume and area of active site of both susceptible and resistant biotypes has been simulated. Isoproturon was docked at the active site of both, susceptible and resistant D1 proteins. Modeling and simulation of resistance D1 protein indicates that the resistance is due to alteration in secondary structure near the binding site, resulting in loss in cavity area, volume and change in binding position, loss of hydrogen bonds, hydrophobic interaction and complete loss of hydrophobic sites. To regain sensitivity in resistant biotype new derivatives of isoproturon molecules have been proposed, synthesized and tested. Among the 17 derivatives we found that the N-methyl triazole substituted isoproturon is a potential substitute for isoproturon.

  2. Does increased heat resistance result in higher susceptibility to predation? A test using Drosophila melanogaster selection and hardening.

    PubMed

    Hangartner, Sandra; Dworkin, Ian; DeNieu, Michael; Hoffmann, Ary A

    2017-04-07

    Heat resistance of ectotherms can be increased both by plasticity and evolution, but these effects may have trade-offs resulting from biotic interactions. Here we test for predation costs in Drosophila melanogaster populations with altered heat resistance produced by adult hardening and directional selection for increased heat resistance. In addition, we also tested for genetic trade-offs by testing heat resistance in lines that have evolved under increased predation risk. We show that while 35/37°C hardening increases heat resistance as expected, it does not increase predation risk from jumping spiders or mantids; in fact there was an indication that survival may have increased under predation following a triple 37°C compared to a single 35°C hardening treatment. Flies that survived a 39°C selection cycle showed lower survival under predation, suggesting a predation cost of exposure to a more severe heat stress. There was however no correlated response to selection because survival did not differ between control and selected lines after selection was relaxed for one or two generations. In addition, lines selected for increased predation risk did not differ in heat resistance. Our findings suggest independent evolutionary responses to predation and heat as measured in laboratory assays, and no costs of heat hardening on susceptibility to predation. This article is protected by copyright. All rights reserved.

  3. Efficiency of a genetic test to detect benzimidazole resistant Haemonchus contortus nematodes in sheep farms in Quebec, Canada.

    PubMed

    Barrère, Virginie; Keller, Kathy; von Samson-Himmelstjerna, Georg; Prichard, Roger K

    2013-10-01

    Haemonchus contortus is a hemophilic nematode which infects sheep and causes anemia and death to lambs. Benzimidazole drugs are used to remove these parasites, but the phenomenon of resistance has arisen worldwide. A sensitive test to detect resistance before treatment would be a useful tool to enable farmers to anticipate the efficiency of the drug before drenching the flock. In this study, we compared a test for benzimidazole resistance based on detection of genetic markers in H. contortus before treatment with the common method of fecal egg count reduction test (FECRT). We recruited 11 farms from different regions of Quebec for this study. Fecal samples from animals were collected per rectum before and after treatment in control and treated groups (10 animals per group). The 10 sheep were treated with fenbendazole at the recommended dose rate. Among the 11 farms participating in the study, we found H. contortus in 8 of them and it was the most predominant nematode species detected by egg count. Using the genetic test, we found benzimidazole resistance in each of these 8 farms. In 5 of these 8 farms there were sufficient sheep with an egg count for H. contortus above 150 eggs per gram to allow the FECRT test to be conducted. Benzimidazole resistance was observed in each of these 5 farms by the FECRT. When we compared the results from the genetic test for samples off pasture and from individual sheep, with the results from the FECRT, we concluded that the genetic test can be applied to samples collected off pasture to estimate benzimidazole resistance levels before treatment for H. contortus infections.

  4. 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).

  5. 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).

  6. 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.

  7. 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

  8. Two-dimensional airflow modeling underpredicts the wind velocity over dunes.

    PubMed

    Michelsen, Britt; Strobl, Severin; Parteli, Eric J R; Pöschel, Thorsten

    2015-11-17

    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.

  9. 77 FR 809 - Request for Proposals for Certification and Testing Expertise for the Ballistic Resistance of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-06

    ... Resistance of Personal Body Armor (2008) Standard AGENCY: National Institute of Justice, Department of... Institute of Justice (NIJ) is in the process of revising its Ballistic Resistance of Personal Body...

  10. PHENOTYPIC AND GENETIC HETEROGENEITY AMONG SUBJECTS WITH MILD AIRFLOW OBSTRUCTION IN COPDGENE

    PubMed Central

    Lee, Jin Hwa; Cho, Michael H.; McDonald, Merry-Lynn N.; Hersh, Craig P.; Castaldi, Peter J.; Crapo, James D.; Wan, Emily S.; Dy, Jennifer G.; Chang, Yale; Regan, Elizabeth A.; Hardin, Megan; DeMeo, Dawn L.; Silverman, Edwin K.

    2014-01-01

    Background Chronic obstructive pulmonary disease (COPD) is characterized by marked phenotypic heterogeneity. Most previous studies have focused on COPD subjects with FEV1 < 80% predicted. We investigated the clinical and genetic heterogeneity in subjects with mild airflow limitation in spirometry grade 1 defined by the Global Initiative for chronic Obstructive Lung Disease (GOLD 1). Methods Data from current and former smokers participating in the COPDGene Study (NCT00608764) were analyzed. K-means clustering was performed to explore subtypes within 794 GOLD 1 subjects. For all subjects with GOLD 1 and with each cluster, a genome-wide association study and candidate gene testing were performed using smokers with normal lung function as a control group. Combinations of COPD genome-wide significant single nucleotide polymorphisms (SNPs) were tested for association with FEV1 (% predicted) in GOLD 1 and in a combined group of GOLD1 and smoking control subjects. Results K-means clustering of GOLD 1 subjects identified putative “near-normal”, “airway-predominant”, “emphysema-predominant” and “lowest FEV1 % predicted” subtypes. In non-Hispanic whites, the only SNP nominally associated with GOLD 1 status relative to smoking controls was rs7671167 (FAM13A) in logistic regression models with adjustment for age, sex, pack-years of smoking, and genetic ancestry. The emphysema-predominant GOLD 1 cluster was nominally associated with rs7671167 (FAM13A) and rs161976 (BICD1). The lowest FEV1 % predicted cluster was nominally associated with rs1980057 (HHIP) and rs1051730 (CHRNA3). Combinations of COPD genome-wide significant SNPs were associated with FEV1 (% predicted) in a combined group of GOLD 1 and smoking control subjects. Conclusions Our results indicate that GOLD 1 subjects show substantial clinical heterogeneity, which is at least partially related to genetic heterogeneity. PMID:25154699

  11. Testing the Effectiveness of Intervention Programs on Children's Compliance-Resisting Behaviors.

    ERIC Educational Resources Information Center

    McQuillen, Jeffrey S.; And Others

    A study examined the effectiveness of a resistance-based prevention program to increase subjects' ability to comprehend and apply resistance skills. Subjects were 30 participants in kindergarten through third grade. Fifteen subjects received resistance-based prevention training from the We Help Ourselves (WHO) program. The remaining 15 subjects…

  12. Testing mediator variables in a resistance training intervention for obese adults with type 2 diabetes.

    PubMed

    Lubans, David R; Plotnikoff, Ronald C; Jung, Mary; Eves, Neil; Sigal, Ron

    2012-01-01

    A poor understanding of behaviour change mechanisms has hindered the development of effective physical activity interventions. The aim of this study was to identify potential mediators of change in a home-based resistance training (RT) program for obese individuals with type 2 diabetes. Obese individuals with type 2 diabetes (N = 48) were randomly allocated to either an RT intervention (n = 27) or a control group (n = 21) for the 16-week study period. The study sample included 16 men and 32 women and the mean age of participants was 54.4 (±11.7) years. Participants in the RT group received a multi-gym and dumbbells and home supervision from a certified personal trainer. RT behaviour was measured using a modified Godin Leisure Time Questionnaire. Social-cognitive constructs were measured and tested in a mediating variable framework using a product-of-coefficients test. The intervention had a significant effect on RT behaviour (p < 0.001) and muscular strength (p < 0.001). The intervention had a significant effect on RT planning strategies (p < 0.01), which mediated the effect of the intervention on RT behaviour. The home-based RT program successfully targeted participants' RT planning strategies which contributed to their exercise adherence.

  13. Assessing the SEU resistance of CMOS latches using alpha-particle sensitive test circuits

    NASA Technical Reports Server (NTRS)

    Buehler, M.; Blaes, B.; Nixon, R.

    1990-01-01

    The importance of Cosmic Rays on the performance of integrated circuits (IC's) in a space environment is evident in the upset rate of the Tracking and Data Relay Satellite (TDRS) launched in Apr. 1983. This satellite experiences a single-event-upset (SEU) per day which must be corrected from the ground. Such experience caused a redesign of the Galileo spacecraft with SEU resistant IC's. The solution to the SEU problem continues to be important as the complexity of spacecraft grows, the feature size of IC's decreases, and as space systems are designed with circuits fabricated at non-radiation hardened foundries. This paper describes an approach for verifying the susceptibility of CMOS latches to heavy-ion induced state changes. The approach utilizes alpha particles to induce the upsets in test circuits. These test circuits are standard cells that have offset voltages which sensitize the circuits to upsets. These results are then used to calculate the upsetability at operating voltages. In this study results are presented for the alpha particle upset of a six-transistor static random access memory (SRAM) cell. Then a methodology is described for the analysis of a standard-cell inverter latch.

  14. Effects of blood lead levels on airflow limitations in Korean adults: Findings from the 5th KNHNES 2011

    SciTech Connect

    Chung, Hye Kyung; Chang, Yoon Soo; Ahn, Chul Woo

    2015-01-15

    This study aimed to examine whether blood levels of heavy metals, such as lead, mercury and cadmium, are related with pulmonary function in Korean adults. This investigation included 870 Korean adults (≥40 years) who received pulmonary function testing in the Korea National Health and Nutrition Examination Survey (KNHANES) V-2, 2011. Data of blood levels of heavy metals, pulmonary function tests and anthropometric measurements were acquired. Blood lead levels showed inverse correlations with the FEV{sub 1}/FVC ratio before (r=−0.276, p<0.001) and after adjustment of multiple compounding factors (r=−0.115, p=0.001). A logistic multiple regression analysis revealed that blood lead levels were a significant influencing factor for the FEV{sub 1}/FVC ratio (β=−0.017, p=0.001, adjusted R{sup 2}=0.267). The odds ratios (ORs) for the FEV{sub 1}/FVC ratio were significantly lower in the highest tertile group of the blood lead levels than in the lowest tertile group in Model 1 (OR=0.007, 95% CI=0.000−0.329) and Model 2 (OR=0.006, 95% CI=0.000−0.286). These findings imply that environmental exposure to lead might be an important factor that may cause airflow limitations in Korean adults. - Highlights: • Blood lead levels showed inverse correlations with the FEV{sub 1}/FVC ratio. • Blood lead level was a significant influencing factor for the FEV{sub 1}/FVC ratio. • ORs for FEV{sub 1}/FVC were lower in the highest blood lead group than in the lowest group. • Environmental exposure to lead might be an important factor for airflow limitations.

  15. Underestimation of the resistance of Mycobacterium tuberculosis to second-line drugs by the new GenoType MTBDRsl test.

    PubMed

    Jin, Jialin; Shen, Yaojie; Fan, Xiaoping; Diao, Ni; Wang, Feifei; Wang, Sen; Weng, Xinhua; Zhang, Wenhong

    2013-01-01

    The GenoType MTBDRsl is a new-generation PCR-based line-probe assay for the detection of extensively drug-resistant tuberculosis (XDR-TB). This study evaluated the performance of MTBDRsl in detecting genotypic resistance to ethambutol, kanamycin, and ofloxacin in Mycobacterium tuberculosis (MTB) strains. The drug resistance of 262 unique clinical MTB isolates from China was analyzed with MTBDRsl, traditional TB drug susceptibility testing (DST), and sequencing. Sensitivity of MTBDRsl was 62.4% (93/149; 95% CI = 54.1 to 70.2) for detection of ethambutol resistance, 57.9% (55/95; 95% CI = 47.3 to 68) for kanamycin resistance, and 81% (111/137; 95% CI = 73.4 to 87.2) for ofloxacin resistance; specificity was 76.8% (86/112; 95% CI = 67.9 to 84.2), 98.8% (164/166; 95% CI = 95.7 to 99.9), and 91.1% (113/124; 95% CI = 84.7 to 95.5), respectively. Sequencing suggested that 36.9% (55/149) of ethambutol-resistant strains had no embB306 mutation and that 26.8% (40/149) had embB497 mutation not covered by MTBDRsl. Furthermore, MTBDRsl indicated ethambutol resistance in 23.2% (26/112) of ethambutol-susceptible strains, of which 92.3% (24/26) were confirmed resistant by sequencing. This study demonstrated that genotypic resistance to ethambutol, kanamycin, and ofloxacin in MTB can be quickly determined with the MTBDRsl. As a rapid and convenient genetic method, this assay could function as a supplement to traditional DST. More relevant genetic markers are needed to improve sensitivity.

  16. Doppler laser flowmetry test of the functional condition of precapillar and postcapillar resistance in essential hypertensive patients

    NASA Astrophysics Data System (ADS)

    Lukjanov, Valdimir F.

    2000-04-01

    243 patient of essential hypertension were examined with the help of Doppler-Laser Flowmetry, optical photometry. Flowmetry was used to measure vasomotion and blood flow after arterial compression, decompression and venous hyperemia were held. New Doppler-Laser flowmetry diagnostic test of functional condition of microcirculation was worked out of find precapillary and postcapillar resistance. Precapillary resistance included next basis parameters: vasomotion with high frequency and low amplitude, latent time after decompression, large postocclusive reactive hyperemia, absent venous hyperemia. Postcapillar amplitude, little or absent postocclusive reactive hyperemia, large venous hyperemia. This test-method was applied to select pathogenetic treatment of essential hypertension.

  17. Testing the causality between CYP9M10 and pyrethroid resistance using the TALEN and CRISPR/Cas9 technologies.

    PubMed

    Itokawa, Kentaro; Komagata, Osamu; Kasai, Shinji; Ogawa, Kohei; Tomita, Takashi

    2016-04-20

    Recently-emerging genome editing technologies have enabled targeted gene knockout experiments even in non-model insect species. For studies on insecticide resistance, genome editing technologies offer some advantages over the conventional reverse genetic technique, RNA interference, for testing causal relationships between genes of detoxifying enzymes and resistance phenotypes. There were relatively abundant evidences indicating that the overexpression of a cytochrome P450 gene CYP9M10 confers strong pyrethroid resistance in larvae of the southern house mosquito Culex quinquefasciatus. However, reverse genetic verification has not yet been obtained because of the technical difficulty of microinjection into larvae. Here, we tested two genome editing technologies, transcription activator-like effector nucleases (TALEN)s and clustered regularly interspaced short palindromic repeats (CRISPR/Cas9), to disrupt CYP9M10 in a resistant strain of C. quinquefasciatus. Additionally, we developed a novel, effective approach to construct a TALE using the chemical cleavage of phosphorothioate inter-nucleotide linkages in the level 1 assembly. Both TALEN and CRISPR/Cas9 induced frame-shifting mutations in one or all copies of CYP9M10 in a pyrethroid-resistant strain. A line fixed with a completely disrupted CYP9M10 haplotype showed more than 100-fold reduction in pyrethroid resistance in the larval stage.

  18. Testing the causality between CYP9M10 and pyrethroid resistance using the TALEN and CRISPR/Cas9 technologies

    PubMed Central

    Itokawa, Kentaro; Komagata, Osamu; Kasai, Shinji; Ogawa, Kohei; Tomita, Takashi

    2016-01-01

    Recently-emerging genome editing technologies have enabled targeted gene knockout experiments even in non-model insect species. For studies on insecticide resistance, genome editing technologies offer some advantages over the conventional reverse genetic technique, RNA interference, for testing causal relationships between genes of detoxifying enzymes and resistance phenotypes. There were relatively abundant evidences indicating that the overexpression of a cytochrome P450 gene CYP9M10 confers strong pyrethroid resistance in larvae of the southern house mosquito Culex quinquefasciatus. However, reverse genetic verification has not yet been obtained because of the technical difficulty of microinjection into larvae. Here, we tested two genome editing technologies, transcription activator-like effector nucleases (TALEN)s and clustered regularly interspaced short palindromic repeats (CRISPR/Cas9), to disrupt CYP9M10 in a resistant strain of C. quinquefasciatus. Additionally, we developed a novel, effective approach to construct a TALE using the chemical cleavage of phosphorothioate inter-nucleotide linkages in the level 1 assembly. Both TALEN and CRISPR/Cas9 induced frame-shifting mutations in one or all copies of CYP9M10 in a pyrethroid-resistant strain. A line fixed with a completely disrupted CYP9M10 haplotype showed more than 100-fold reduction in pyrethroid resistance in the larval stage. PMID:27095599

  19. Body mass index, airflow obstruction and dyspnea and body mass index, airflow obstruction, dyspnea scores, age and pack years-predictive properties of new multidimensional prognostic indices of chronic obstructive pulmonary disease in primary care

    PubMed Central

    Ansari, Khalid; Keaney, Niall; Kay, Andrea; Price, Monica; Munby, Joan; Billett, Andrew; Haggerty, Sharon; Taylor, Ian K.; Al Otaibi, Hajed

    2016-01-01

    BACKGROUND: The assessment of the severity of chronic obstructive pulmonary disease (COPD) should involve a multidimensional approach that is now clearly shown to be better than using spirometric impairment alone. The aim of this study is to validate and compare novel tools without an exercise test and to extend prognostic value to patients with less severe impairment of Forced expiratory volume 1 s. METHODS: A prospective, observational, primary care cohort study identified 458 eligible patients recruited from the primary care clinics in the northeast of England in 1999–2002. A new prognostic indicator – body mass index, airflow obstruction and dyspnea (BOD) together with the conventional prognostic indices age, dyspnea and airflow obstruction (ADO), global initiative for chronic obstructive lung disease (GOLD) and new GOLD matrix were studied. We also sought to improve prognostication of BOD by adding age (A) and smoking history as pack years (S) to validate BODS (BOD with smoking history) and BODAS (BOD with smoking history and age) as prognostic tools and the predictive power of each was analyzed. RESULTS: The survival of the 458 patients was assessed after a median of 10 years when the mortality was found to be 33.6%. The novel indices BOD, BODS, and BODAS were significantly predictive for all-cause mortality in our cohort. Furthermore with ROC analysis the C statistics for BOD, BODS, and BODAS were 0.62, 0.66, and 0.72, respectively (P < 0.001 for each), whereas ADO and GOLD stages had a C statistic of 0.70 (P < 0.001) and 0.56 (P < 0.02), respectively. GOLD Matrix was not significant in this cohort. CONCLUSION: BOD, BODS, and BODAS scores are validated predictors of all-cause mortality in a primary care cohort with COPD. PMID:27803752

  20. Testing Strength of Biotic Resistance against an Introduced Fish: Inter-Specific Competition or Predation through Facultative Piscivory?

    PubMed Central

    Britton, J. Robert

    2012-01-01

    Biotic resistance is the process where aspects of the receiving environment inhibit the establishment and invasion of an introduced species. Resistance against an introduced fish can be through strong competition and/or predation from resident fishes. Here, the biotic resistance against introduced topmouth gudgeon Pseudorasbora parva (a highly invasive fish in Europe) by resident carp Cyprinus carpio was tested in experimental mesocosms. The introduction scenario was six adult P. parva (three male, three female) on a single occasion. Resistance to their establishment was provided by three and six resident C. carpio whose effects on P. parva growth and reproduction were compared to a Control (no resident fish at the time of introduction) and treatments containing three and six P. parva. After 120 days, the growth rates of the introduced P. parva were significantly depressed in C. carpio presence and in mesocosms with three C. carpio present, significantly decreased numbers of 0+P. parva were recorded. Where six C. carpio were present, no 0+P. parva were recorded, indicating resistance strength increased with carp abundance. In contrast, there were no differences in P. parva reproduction and growth rates between the Control and treatments containing conspecifics. Stable isotope analysis (δ15N, δ13C) revealed C. carpio were feeding at one trophic level above 0+P. parva, suggesting the process of resistance was predation (facultative piscivory) rather than competition. Thus, if P. parva are to establish and invade following an introduction, they must overcome this biotic resistance from cyprinid fishes such as C. carpio. PMID:22363711