Science.gov

Sample records for mixtures involving blowing

  1. Blowing up the Earth

    NASA Astrophysics Data System (ADS)

    Benge, Raymond

    2006-10-01

    An occasional theme in science fiction involves blowing up a planet. In ``Star Wars,'' the Death Star blows up Alderan. In ``The Hitchhiker's Guide to the Galaxy,'' a Vorgon destructor fleet blows up Earth to make room for a cosmic bypass. So, as an exercise for upper division students, or the more advance first year calculus based physics students, the energy needed to disassemble Earth can be computed. Assuming that advanced scifi aliens get their energy from matter-antimatter interactions, students can then compute the amount of antimatter needed to accomplish the task.

  2. Analysis and computer tools for separation processes involving nonideal mixtures

    SciTech Connect

    Lucia, A.

    1992-05-01

    The objectives of this research, were to continue to further both the theoretical understanding of and the development of computer tools (algorithms) for separation processes involving nonideal mixtures. These objectives were divided into three interrelated major areas -- the mathematical analysis of the number of steady-state solutions to multistage separation processes, the numerical analysis of general, related fixed-point methods, and the development and implementation of computer tools for process simulation.

  3. Diurnal patterns of blowing sand

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The diurnal pattern of blowing sand results from a complex process that involves an interaction between solar heating, thermal instability, atmospheric turbulence, wind strength, and surface threshold conditions. During the day, solar heating produces thermal instability, which enhances the convect...

  4. Diurnal patterns of blowing sand

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The diurnal pattern of blowing sand results from a complex process that involves the interaction between the sun, wind, and earth. During the day, solar heating produces thermal instability, which enhances the convective mixing of high momentum winds from the upper levels of the atmosphere to the s...

  5. Tire blow-outs and motorway accidents.

    PubMed

    Martin, Jean-Louis; Laumon, Bernard

    2005-03-01

    During the period from 1996 to 2002, 60,397 vehicles were involved in crashes with property damage and/or injury on a French motorway network of 2000 km. It was observed that 6.7% of these accidents involved tire blow-outs. In 87% of cases, only one vehicle was involved in the accident. Tire blow-outs occurred in 6.5% of cars that represented more than 80% of the vehicles involved in crashes. The occurrence of this phenomenon is very high for vans (22%), though it concerns trucks less (2.5%). The proportion of tire blow-outs decreased from 1997, when it was 8.0%, to 5.9% in 2002. However, two main facts require examination: (1) On inter-urban motorways, crashes involving blow-outs of rear tires occur four times more frequently than for blow-outs of front tires. (2) The frequency of tire blow-outs is especially high for vans, and almost always involves rear tires. This higher frequency for rear tires is the result of two phenomena, which are indistinguishable given the data available: firstly, a four-wheel vehicle is more difficult to control if a blow-out occurs on a rear tire (confirmed experimentally); secondly, rear tires may be in poor condition more often than front tires, and so more prone to blow-outs. Consequently, users are strongly recommended to install the best tires on rear wheels. In practice, if only the front tires are replaced, which often occurs because they tend to be worn out more quickly than the rear ones (especially for front wheel drive vehicles), it is necessary to move the rear tires to the front and fit the new ones on the rear wheels. Very interesting technological developments are in progress that should reduce the number of tire blow-outs. However, considering the time necessary to renew the number of cars on the roads, this very simple and inexpensive recommendation should apply to all cars and especially to vans. PMID:15823875

  6. Five Blows to Mankind's Narcissism.

    ERIC Educational Resources Information Center

    Pedrini, D. T.; Pedrini, Bonnie C.

    1978-01-01

    Freud identified three blows to mankind's narcissism--cosmological, biological, and psychological. Conjectural fourth and fifth blows might be universological (the discovery of other intelligent beings) and earthological (the demise of this planet via waste, pollution, etc.). (Author/JC)

  7. Oscillatory blowing airfoil

    NASA Technical Reports Server (NTRS)

    1997-01-01

    10' NACA 0015 with 30% chord trailing edge flap deflected 20 degrees. Used in 0.3 Meter Transonic Cryogenic Tunnel, this airfoil has a 0.44 mm slot at 70% chord. Oscillatory blowing out of slot used for separation control. Howard Price appears in side view shot, in building 1145, Studio.

  8. Always Blowing Bubbles.

    ERIC Educational Resources Information Center

    Grambo, Gregory

    1995-01-01

    Ways to explore blowing bubbles through observation, experimentation, and discovery are suggested to stimulate gifted children, with attention to such areas as the function of film in the liquid and the reason for the common spherical shape of bubbles. Experiments that children can try and tips for the teacher are presented. (SW)

  9. Analysis and computer tools for separation processes involving nonideal mixtures. Progress report, December 1, 1992--November 30, 1993

    SciTech Connect

    Lucia, A.

    1993-07-12

    This research is concerned with developing mathematical analysis, numerical analysis, and computer tools for separation processes involving nonideal, homogeneous, and heterogeneous multi-component mixtures. Progress, organized in terms of mathematical analysis, numerical analysis, and algorithmic development, is summarized.

  10. Blowing DNA bubbles.

    PubMed

    Severin, N; Zhuang, W; Ecker, C; Kalachev, A A; Sokolov, I M; Rabe, J P

    2006-11-01

    We report here experimental observations which indicate that topologically or covalently formed polymer loops embedded in an ultrathin liquid film on a solid substrate can be "blown" into circular "bubbles" during scanning force microscopy (SFM) imaging. In particular, supercoiled vector DNA has been unraveled, moved, stretched, and overstretched to two times its B-form length and then torn apart. We attribute the blowing of the DNA bubbles to the interaction of the tapping SFM tip with the ultrathin liquid film.

  11. Blow out preventer

    SciTech Connect

    Bruce, A.I.

    1980-06-10

    In oil and gas well pumping apparatus, a polish rod reciprocates through a stuffing box and connects to a submersible pump through a tubing string or the like. When servicing, it is desirable to close off the gas or oil pressure from below and hydraulic fluid is routed from a remote location to the blow out preventer. The blow out preventer consists of a cylindrical casing with a cap screw threadably engaged to the upper end thereof and containing a cylindrical spool or the like formed from elastomeric material having an annular channel around the outer perimeter which is operatively connected to the source of hydraulic fluid. When it is desired to close off the blow out preventer, hydraulic fluid is pumped under pressure to the channel thus forcing the center of the spool inwardly and clamping same around the polish rod thereby closing off the passageway around the polish rod. O rings surround the spool above and below the channel and assist in sealing. Upper and lower steps in the casing slope outwardly and away from one another to facilitate the return of the spool to the normal position when pressure is released.

  12. Blowing Agents for Fabrication of Polyimide Foams

    NASA Technical Reports Server (NTRS)

    Gagliani, J.; Sorathia, U. A. K.; Lee, R.

    1982-01-01

    Polyimide resin can be foamed by agent generated within matrix of powder precursor. Blowing agent is mixture of water and methanol that are byproducts of condensation/polymerization reaction in resin. Expansion of these two compounds produces cellular foam structure that is flexible and resilient but that tends to have very-fine cellular structure. More open structure with lower density can be attained by modifying mechanism of foam formation. Foams have applications as fillers for seat cushions, wall panels, floor sheets, and thermal and acoustical insulation.

  13. Flap-Edge Blowing Experiments

    NASA Technical Reports Server (NTRS)

    Gaeta, R. J.; Englar, R. J.; Ahuja, K. K.

    2003-01-01

    This Appendix documents the salient results from an effort to mitigate the so-called flap-edge noise generated at the split between a flap edge that is deployed and the undeployed flap. Utilizing a Coanda surface installed at the flap edge, steady blowing was used in an attempt to diminish the vortex strength resulting from the uneven lift distribution. The strength of this lifting vortex was augmented by steady blowing over the deployed flap. The test article for this study was the same 2D airfoil used in the steady blowing program reported earlier (also used in pulsed blowing tests, see Appendix G), however its trailing edge geometry was modified. An exact duplicate of the airfoil shape was made out of fiberglass with no flap, and in the clean configuration. It was attached to the existing airfoil to make an airfoil that has half of its flap deployed and half un-deployed. Figure 1 shows a schematic of the planform showing the two areas where steady blowing was introduced. The flap-edge blowing or the auxiliary blowing was in the direction normal to the freestream velocity vector. Slot heights for the blowing chambers were on the order of 0.0 14 inches.

  14. Blowing a liquid curtain

    NASA Astrophysics Data System (ADS)

    Lhuissier, H.; Brunet, P.; Dorbolo, S.

    2015-11-01

    We study the response of a steady free-falling liquid curtain perturbed by focused air jets blowing perpendicularly against it. Asymmetric and symmetric perturbations are applied by using either a single pulsed jet or two identical steady jets facing each other. The response strongly depends on the curtain flow rate, and the location and strength of the perturbation. For pulsed asymmetric perturbations of increasing amplitude, sinuous wave, drop ejection, bubble ejection, and hole opening are successively observed. For steady symmetric perturbations, a steady hole forms downstream in the wake. For this latter case, we present a model for the curtain thickness and the location of the hole inthe wake which compares favorably to the experiments providing the perturbation is small enough (jet stagnation pressure smaller than curtain stagnation pressure) and the liquid viscosity is negligible.

  15. Bilateral Sequential Pneumolabyrinth Resulting from Nose Blowing

    PubMed Central

    Lee, Joong Seob; Kwon, Sae Young; Kim, Ji Heui

    2015-01-01

    Pneumolabyrinth describes a condition with entrapped air in the labyrinth and usually occurs in temporal bone fractures that involve the otic capsule. While sporadic cases of bilateral pneumolabyrinth have been reported, cases lacking head trauma are very rare. We report the case of a 43-year-old man who had sudden hearing loss bilaterally after blowing his nose at an interval of 1 year. Although conservative management for the right ear and exploratory tympanotomy with sealing of the possible site of perilymphatic leakage in the left ear were performed, hearing outcome was poor in both ears. To our knowledge, this is the first case of bilateral pneumolabyrinth occurring as a result of nose blowing. PMID:26771019

  16. Bilateral Sequential Pneumolabyrinth Resulting from Nose Blowing.

    PubMed

    Lee, Joong Seob; Kwon, Sae Young; Kim, Ji Heui; Kim, Hyung-Jong

    2015-12-01

    Pneumolabyrinth describes a condition with entrapped air in the labyrinth and usually occurs in temporal bone fractures that involve the otic capsule. While sporadic cases of bilateral pneumolabyrinth have been reported, cases lacking head trauma are very rare. We report the case of a 43-year-old man who had sudden hearing loss bilaterally after blowing his nose at an interval of 1 year. Although conservative management for the right ear and exploratory tympanotomy with sealing of the possible site of perilymphatic leakage in the left ear were performed, hearing outcome was poor in both ears. To our knowledge, this is the first case of bilateral pneumolabyrinth occurring as a result of nose blowing. PMID:26771019

  17. Suppression of sourness: a comparative study involving mixtures of organic acids and sugars.

    PubMed

    Savant, Lotika; McDaniel, Mina R

    2004-05-01

    The degree of sourness suppression of perceptually equisour levels of citric, lactic, and malic acids by equal molar and weight amounts of sucrose, fructose, and glucose was determined in binary mixtures. Equisour acid levels were obtained by magnitude estimation. Mixture intensity ratings were collected on a categorical scale, using trained panelists. In general, equal sugar molarities and weights did not effect equivalent suppression. Instead, the perceived intensity of the sugars appeared to suppress sourness more systematically, implying that dominantly central neural mechanisms underlie suppression. This was confirmed when no significant differences were found between the suppressive abilities of sweetness-matched levels of sucrose, fructose, and an equiratio mixture of the two on citric acid sourness. The possibility of a separate receptor site/mechanism for glucose and a small peripheral component to suppression is also suggested.

  18. Phase equilibria of binary liquid crystal mixtures involving induced ordered phases

    NASA Astrophysics Data System (ADS)

    Huang, Tsang-Min

    A phenomenological model for elucidating phase diagrams of hexagonal columnar/nematic liquid crystal mixtures has been developed on the basis of the combination of the Flory-Huggins (FH) free energy of isotropic mixing, Maier-Saupe (MS) free energy for nematic ordering, and Chandrasekhar-Clark free energy for hexagonal ordering. Self-consistent calculations show the theory is capable of predicting the various phase diagrams, covering nematic, hexagonal columnar, and isotropic phases. The model has been tested with the eutectic phase diagram of hexagonal columnar liquid crystal, 2, 3, 6, 7, 10, 11-hexapentyloxy triphenylene (HPTP)/reactive nematic mesogens, 4-(3-acryloyloxypropyloxy)-benzoic acid 2-methyl-1, 4-phenylene ester (RM257) mixtures determined by using DSC, polarized optical microscope (POM), and wide-angle X-ray diffraction (WAXD). The self-consistent calculation displays isotropic (I), nematic (N), hexagonal columnar (Colh), N + I, and Colh + I, and Colh + N coexistence regions. These phase regions has been confirmed by thermal quenching various compositions from the isotropic melt to different phase regions. Guided by the established phase diagram of HPTP/RM257 mixtures, photo-polymerization of the mixture has been carried out in different phase regions. The as-cured HPTP/p-(RM257) composites fabricated at isotropic phase (130 °C) remains single isotropic phase under optical microscope, whereas the SEM and TEM results show the bead-like microstructure with sub-micrometer scale. Polymerization-induced mesophase transition experiments have been carried out at isotropic temperatures slightly above the clearing point of the mixtures. Of particular interest is the development of liquid crystalline spherulites. Moreover, the fixation of the morphology is observed when the photopolymerization is carried out in the N, N + I, and N + Colh region. A generalized thermodynamic model for describing smectic A and smectic B ordering has been developed based on

  19. Phase diagram involving the mesomorphic behavior of binary mixture of sodium oleate and orthophosphoric acid

    NASA Astrophysics Data System (ADS)

    Govindaiah, T. N.; Sreepad, H. R.

    2015-04-01

    The present investigation deals with the binary mixture of two non-mesogenic compounds, viz. sodium oleate (Naol) and orthophosphoric acid (H3PO4) which exhibits very interesting liquid crystalline smectic phases at large range of concentrations and temperature. The mixtures with concentrations ranging from 10% to 90% Naol in H3PO4 exhibit SmA, SmC, SmE and SmB phases, sequentially when the specimen is cooled from its isotropic phase. Physical properties, such as ultrasonic velocity, adiabatic compressibility and molar compressibility, show anomalous behavior at the isotropic to mesosphase transition.

  20. Analysis and computer tools for separation processes involving nonideal mixtures. Progress report, December 1, 1989--November 30, 1992

    SciTech Connect

    Lucia, A.

    1992-05-01

    The objectives of this research, were to continue to further both the theoretical understanding of and the development of computer tools (algorithms) for separation processes involving nonideal mixtures. These objectives were divided into three interrelated major areas -- the mathematical analysis of the number of steady-state solutions to multistage separation processes, the numerical analysis of general, related fixed-point methods, and the development and implementation of computer tools for process simulation.

  1. Lasing characteristics of gas mixtures involving UFG: Application to nuclear pumping of lasers

    NASA Technical Reports Server (NTRS)

    Verdeyen, J. T.; Eden, J. G.

    1980-01-01

    Intense blue-green fluorescence from a structured band centered at lambda approximately 484 nm was observed from Ar, CF3I and NF3 gas mixtures excited by an electron beam. This emission was tentatively assigned to the E yields A transition of the iodine monofluoride (IF) molecule. The fluorescence efficiency of the IF(E yields A) band and the IF (E) state radiative lifetime were estimated to be approximately 6% and 15 ns, respectively. The emission band structure, the short IF(E) radiative lifetime and the Franck-Condon shift between the E and A states suggest that IF is an attractive candidate for a blue-green laser.

  2. Blowing Flap Experiment: PIV Measurements

    NASA Technical Reports Server (NTRS)

    Hutcheson, Florence V.; Stead, Daniel J.; Bremmer, David M.

    2004-01-01

    PIV measurements of the flow in the region of a flap side edge are presented for several flap configurations. The test model is a NACA 63(sub 2)-215 Hicks Mod-B main element airfoil with a half-span Fowler flap. Air is blown from small slots located along the flap side edge on either the top, bottom or side surfaces. The test set up is described and flow measurements for a baseline and three blowing flap configurations are presented. The effects that the flap tip jets have on the structure of the flap side edge flow are discussed for each of the flap configurations tested. The results indicate that blowing air from a slot located along the top surface of the flap greatly weakened the top vortex system and pushed it further off the top surface. Blowing from the bottom flap surface kept the strong side vortex further outboard while blowing from the side surface only strengthened the flap vortex system. It is concluded that blowing from the top or bottom surfaces of the flap may lead to a reduction of flap side edge noise.

  3. Shooting method for solution of boundary-layer flows with massive blowing

    NASA Technical Reports Server (NTRS)

    Liu, T.-M.; Nachtsheim, P. R.

    1973-01-01

    A modified, bidirectional shooting method is presented for solving boundary-layer equations under conditions of massive blowing. Unlike the conventional shooting method, which is unstable when the blowing rate increases, the proposed method avoids the unstable direction and is capable of solving complex boundary-layer problems involving mass and energy balance on the surface.

  4. 21 CFR 868.5220 - Blow bottle.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Blow bottle. 868.5220 Section 868.5220 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5220 Blow bottle. (a) Identification. A blow bottle is a...

  5. 21 CFR 868.5220 - Blow bottle.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Blow bottle. 868.5220 Section 868.5220 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5220 Blow bottle. (a) Identification. A blow bottle is a...

  6. 21 CFR 868.5220 - Blow bottle.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Blow bottle. 868.5220 Section 868.5220 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5220 Blow bottle. (a) Identification. A blow bottle is a...

  7. 21 CFR 868.5220 - Blow bottle.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Blow bottle. 868.5220 Section 868.5220 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5220 Blow bottle. (a) Identification. A blow bottle is a...

  8. 21 CFR 868.5220 - Blow bottle.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Blow bottle. 868.5220 Section 868.5220 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5220 Blow bottle. (a) Identification. A blow bottle is a...

  9. Control of Cavity Resonance Using Oscillatory Blowing

    NASA Technical Reports Server (NTRS)

    Scarfe, Alison Lamp; Chokani, Ndaona

    2000-01-01

    The near-zero net mass oscillatory blowing control of a subsonic cavity flow has been experimentally investigated. An actuator was designed and fabricated to provide both steady and oscillatory blowing over a range of blowing amplitudes and forcing frequencies. The blowing was applied just upstream of the cavity front Wall through interchangeable plate configurations These configurations enabled the effects of hole size, hole shape, and blowing angle to be examined. A significant finding is that in terms of the blowing amplitude, the near zero net mass oscillatory blowing is much more effective than steady blowing; momentum coefficients Lip two orders of magnitude smaller than those required for steady blowing are sufficient to accomplish the same control of cavity resonance. The detailed measurements obtained in the experiment include fluctuating pressure data within the cavity wall, and hot-wire measurements of the cavity shear layer. Spectral and wavelet analysis techniques are applied to understand the dynamics and mechanisms of the cavity flow with control. The oscillatory blowing, is effective in enhancing the mixing in the cavity shear layer and thus modifying the feedback loop associated with the cavity resonance. The nonlinear interactions in the cavity flow are no longer driven by the resonant cavity modes but by the forcing associated with the oscillatory blowing. The oscillatory blowing does not suppress the mode switching behavior of the cavity flow, but the amplitude modulation is reduced.

  10. The Early Years: Blowing Bubbles

    ERIC Educational Resources Information Center

    Ashbrook, Peggy

    2016-01-01

    Blowing bubbles is not only a favorite summer activity for young children. Studying bubbles that are grouped together, or "foam," is fun for children and fascinating to many real-world scientists. Foam is widely used--from the bedroom (mattresses) to outer space (insulating panels on spacecraft). Bubble foam can provide children a…

  11. Preventing Blow up by Convective Terms in Dissipative PDE's

    NASA Astrophysics Data System (ADS)

    Bilgin, Bilgesu; Kalantarov, Varga; Zelik, Sergey

    2016-09-01

    We study the impact of the convective terms on the global solvability or finite time blow up of solutions of dissipative PDEs. We consider the model examples of 1D Burger's type equations, convective Cahn-Hilliard equation, generalized Kuramoto-Sivashinsky equation and KdV type equations. The following common scenario is established: adding sufficiently strong (in comparison with the destabilizing nonlinearity) convective terms to equation prevents the solutions from blowing up in a finite time and makes the considered system globally well-posed and dissipative and for weak enough convective terms the finite time blow up may occur similar to the case, when the equation does not involve convective term. This kind of result has been previously known for the case of Burger's type equations and has been strongly based on maximum principle. In contrast to this, our results are based on the weighted energy estimates which do not require the maximum principle for the considered problem.

  12. Preventing Blow up by Convective Terms in Dissipative PDE's

    NASA Astrophysics Data System (ADS)

    Bilgin, Bilgesu; Kalantarov, Varga; Zelik, Sergey

    2016-06-01

    We study the impact of the convective terms on the global solvability or finite time blow up of solutions of dissipative PDEs. We consider the model examples of 1D Burger's type equations, convective Cahn-Hilliard equation, generalized Kuramoto-Sivashinsky equation and KdV type equations. The following common scenario is established: adding sufficiently strong (in comparison with the destabilizing nonlinearity) convective terms to equation prevents the solutions from blowing up in a finite time and makes the considered system globally well-posed and dissipative and for weak enough convective terms the finite time blow up may occur similar to the case, when the equation does not involve convective term. This kind of result has been previously known for the case of Burger's type equations and has been strongly based on maximum principle. In contrast to this, our results are based on the weighted energy estimates which do not require the maximum principle for the considered problem.

  13. Let Them Blow Bubbles.

    ERIC Educational Resources Information Center

    Korenic, Eileen

    1988-01-01

    Describes a series of activities and demonstrations involving the science of soap bubbles. Starts with a recipe for bubble solution and gives instructions for several activities on topics such as density, interference colors, optics, static electricity, and galaxy formation. Contains some background information to help explain some of the effects.…

  14. Black Hole Blows Big Bubble

    NASA Astrophysics Data System (ADS)

    2010-07-01

    Combining observations made with ESO's Very Large Telescope and NASA's Chandra X-ray telescope, astronomers have uncovered the most powerful pair of jets ever seen from a stellar black hole. This object, also known as a microquasar, blows a huge bubble of hot gas, 1000 light-years across, twice as large and tens of times more powerful than other known microquasars. The discovery is reported this week in the journal Nature. "We have been astonished by how much energy is injected into the gas by the black hole," says lead author Manfred Pakull. "This black hole is just a few solar masses, but is a real miniature version of the most powerful quasars and radio galaxies, which contain black holes with masses of a few million times that of the Sun." Black holes are known to release a prodigious amount of energy when they swallow matter. It was thought that most of the energy came out in the form of radiation, predominantly X-rays. However, the new findings show that some black holes can release at least as much energy, and perhaps much more, in the form of collimated jets of fast moving particles. The fast jets slam into the surrounding interstellar gas, heating it and triggering an expansion. The inflating bubble contains a mixture of hot gas and ultra-fast particles at different temperatures. Observations in several energy bands (optical, radio, X-rays) help astronomers calculate the total rate at which the black hole is heating its surroundings. The astronomers could observe the spots where the jets smash into the interstellar gas located around the black hole, and reveal that the bubble of hot gas is inflating at a speed of almost one million kilometres per hour. "The length of the jets in NGC 7793 is amazing, compared to the size of the black hole from which they are launched," says co-author Robert Soria [1]. "If the black hole were shrunk to the size of a soccer ball, each jet would extend from the Earth to beyond the orbit of Pluto." This research will help

  15. Black Hole Blows Big Bubble

    NASA Astrophysics Data System (ADS)

    2010-07-01

    Combining observations made with ESO's Very Large Telescope and NASA's Chandra X-ray telescope, astronomers have uncovered the most powerful pair of jets ever seen from a stellar black hole. This object, also known as a microquasar, blows a huge bubble of hot gas, 1000 light-years across, twice as large and tens of times more powerful than other known microquasars. The discovery is reported this week in the journal Nature. "We have been astonished by how much energy is injected into the gas by the black hole," says lead author Manfred Pakull. "This black hole is just a few solar masses, but is a real miniature version of the most powerful quasars and radio galaxies, which contain black holes with masses of a few million times that of the Sun." Black holes are known to release a prodigious amount of energy when they swallow matter. It was thought that most of the energy came out in the form of radiation, predominantly X-rays. However, the new findings show that some black holes can release at least as much energy, and perhaps much more, in the form of collimated jets of fast moving particles. The fast jets slam into the surrounding interstellar gas, heating it and triggering an expansion. The inflating bubble contains a mixture of hot gas and ultra-fast particles at different temperatures. Observations in several energy bands (optical, radio, X-rays) help astronomers calculate the total rate at which the black hole is heating its surroundings. The astronomers could observe the spots where the jets smash into the interstellar gas located around the black hole, and reveal that the bubble of hot gas is inflating at a speed of almost one million kilometres per hour. "The length of the jets in NGC 7793 is amazing, compared to the size of the black hole from which they are launched," says co-author Robert Soria [1]. "If the black hole were shrunk to the size of a soccer ball, each jet would extend from the Earth to beyond the orbit of Pluto." This research will help

  16. Bernoulli Suction Effect on Soap Bubble Blowing?

    NASA Astrophysics Data System (ADS)

    Davidson, John; Ryu, Sangjin

    2015-11-01

    As a model system for thin-film bubble with two gas-liquid interfaces, we experimentally investigated the pinch-off of soap bubble blowing. Using the lab-built bubble blower and high-speed videography, we have found that the scaling law exponent of soap bubble pinch-off is 2/3, which is similar to that of soap film bridge. Because air flowed through the decreasing neck of soap film tube, we studied possible Bernoulli suction effect on soap bubble pinch-off by evaluating the Reynolds number of airflow. Image processing was utilized to calculate approximate volume of growing soap film tube and the volume flow rate of the airflow, and the Reynolds number was estimated to be 800-3200. This result suggests that soap bubbling may involve the Bernoulli suction effect.

  17. Blow molding of melt processible rubber

    SciTech Connect

    Abell, W.R.; Stuart, R.E.; Myrick, R.E.

    1991-07-01

    This article discusses the advantages of making hollow rubber parts by blow molding thermoplastic elastomers (TPEs) versus conventional rubber processing. It describes the various types of blow molding processes and it provides some insight into the rheological properties of melt processible rubber (MPR) and how MPR should be molded by each of these processes. A number of blow molded applications for MPR are also discussed.

  18. Blowing Circulation Control on a Seaplane Airfoil

    NASA Astrophysics Data System (ADS)

    Guo, B. D.; Liu, P. Q.; Qu, Q. L.

    2011-09-01

    RANS simulations are presented for blowing circulation control on a seaplane airfoil. Realizable k-epsilon turbulent model and pressure-based coupled algorithm with second-order discretization were adopted to simulate the compressible flow. Both clear and simple flap configuration were simulated with blowing momentum coefficient Cμ = 0, 0.15 and 0.30. The results show that blowing near the airfoil trailing edge could enhance the Coanda effect, delay the flow separation, and increase the lift coefficient dramatically. The blowing circulation control is promising to apply to taking off and landing of an amphibious aircraft or seaplane.

  19. Mixture Experiments

    SciTech Connect

    Piepel, Gregory F.

    2007-12-01

    A mixture experiment involves combining two or more components in various proportions or amounts and then measuring one or more responses for the resulting end products. Other factors that affect the response(s), such as process variables and/or the total amount of the mixture, may also be studied in the experiment. A mixture experiment design specifies the combinations of mixture components and other experimental factors (if any) to be studied and the response variable(s) to be measured. Mixture experiment data analyses are then used to achieve the desired goals, which may include (i) understanding the effects of components and other factors on the response(s), (ii) identifying components and other factors with significant and nonsignificant effects on the response(s), (iii) developing models for predicting the response(s) as functions of the mixture components and any other factors, and (iv) developing end-products with desired values and uncertainties of the response(s). Given a mixture experiment problem, a practitioner must consider the possible approaches for designing the experiment and analyzing the data, and then select the approach best suited to the problem. Eight possible approaches include 1) component proportions, 2) mathematically independent variables, 3) slack variable, 4) mixture amount, 5) component amounts, 6) mixture process variable, 7) mixture of mixtures, and 8) multi-factor mixture. The article provides an overview of the mixture experiment designs, models, and data analyses for these approaches.

  20. "Whistle Blowing": Implications for Organizational Communication.

    ERIC Educational Resources Information Center

    Stewart, Lea P.

    1980-01-01

    Examines 51 cases of organizational whistle blowing to derive a model of the steps through which whistle blowing incidents progress. From the model it is possible to generalize about the nature of these incidents and how they fit into patterns of organizational communication. (JMF)

  1. Blowing Polymer Bubbles in an Acoustic Levitator

    NASA Technical Reports Server (NTRS)

    Lee, M. C.

    1985-01-01

    In new manufacturing process, small gas-filled polymer shells made by injecting gas directly into acoustically levitated prepolymer drops. New process allows sufficient time for precise control of shell geometry. Applications foreseen in fabrication of deuterium/tritium-filled fusion targets and in pharmaceutical coatings. New process also useful in glass blowing and blow molding.

  2. Blowing in the Wind Animations

    NASA Technical Reports Server (NTRS)

    2008-01-01

    These are two separate, side-by-side animations made from the same nine images the Surface Stereo Imager (SSI) on NASA's Phoenix Mars Lander took looking into the sky after 5:17 p.m. local time on Sol 8 (June 2, 2008), the eighth Martian day of the mission. The SSI was pointed almost straight up, toward the southwest. Zenith is near the top of the center frame.

    In the left animation, the images were stretched to enhance contrast. The right animation highlights variations between each image and the next. The variations are likely dust blown by winds passing through the SSI's field of view. The images suggest the dust is blowing from west to east.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  3. Magnetism. Blowing magnetic skyrmion bubbles.

    PubMed

    Jiang, Wanjun; Upadhyaya, Pramey; Zhang, Wei; Yu, Guoqiang; Jungfleisch, M Benjamin; Fradin, Frank Y; Pearson, John E; Tserkovnyak, Yaroslav; Wang, Kang L; Heinonen, Olle; te Velthuis, Suzanne G E; Hoffmann, Axel

    2015-07-17

    The formation of soap bubbles from thin films is accompanied by topological transitions. Here we show how a magnetic topological structure, a skyrmion bubble, can be generated in a solid-state system in a similar manner. Using an inhomogeneous in-plane current in a system with broken inversion symmetry, we experimentally "blow" magnetic skyrmion bubbles from a geometrical constriction. The presence of a spatially divergent spin-orbit torque gives rise to instabilities of the magnetic domain structures that are reminiscent of Rayleigh-Plateau instabilities in fluid flows. We determine a phase diagram for skyrmion formation and reveal the efficient manipulation of these dynamically created skyrmions, including depinning and motion. The demonstrated current-driven transformation from stripe domains to magnetic skyrmion bubbles could lead to progress in skyrmion-based spintronics. PMID:26067256

  4. Magnetism. Blowing magnetic skyrmion bubbles.

    PubMed

    Jiang, Wanjun; Upadhyaya, Pramey; Zhang, Wei; Yu, Guoqiang; Jungfleisch, M Benjamin; Fradin, Frank Y; Pearson, John E; Tserkovnyak, Yaroslav; Wang, Kang L; Heinonen, Olle; te Velthuis, Suzanne G E; Hoffmann, Axel

    2015-07-17

    The formation of soap bubbles from thin films is accompanied by topological transitions. Here we show how a magnetic topological structure, a skyrmion bubble, can be generated in a solid-state system in a similar manner. Using an inhomogeneous in-plane current in a system with broken inversion symmetry, we experimentally "blow" magnetic skyrmion bubbles from a geometrical constriction. The presence of a spatially divergent spin-orbit torque gives rise to instabilities of the magnetic domain structures that are reminiscent of Rayleigh-Plateau instabilities in fluid flows. We determine a phase diagram for skyrmion formation and reveal the efficient manipulation of these dynamically created skyrmions, including depinning and motion. The demonstrated current-driven transformation from stripe domains to magnetic skyrmion bubbles could lead to progress in skyrmion-based spintronics.

  5. Catanionic mixtures involving a drug: a rather general concept that can be utilized for prolonged drug release from gels.

    PubMed

    Bramer, Tobias; Dew, Noel; Edsman, Katarina

    2006-04-01

    The aim of this work was to study at what extent mixtures of drug substances and oppositely charged surfactants form catanionic aggregates and to apply these as a means of obtaining prolonged drug release from a gel. The properties of traditional catanionic mixtures are relatively well known, but only recently we found that not only traditional surfactants form these mixtures, but also structurally more complex surface active drug compounds. In this study, several different compositions of catanionic mixtures were studied visually, by cryogenic transmission electron microscopy (cryo-TEM) and rheologically using a Bohlin VOR Rheometer. Some of the catanionic vesicle and micelle phases were incorporated in and released from gels using the USP paddle method. The drug compounds investigated were lidocaine, ibuprofen, naproxen, alprenolol, propranolol, and orphenadrine. Of the six drug molecules used in this study, five, both positively and negatively charged, were capable of forming catanionic vesicles and/or micelles with oppositely charged surfactants. The drug release studies show that catanionic drug surfactant mixtures are beneficial for obtaining prolonged release from gels, as the drug release using catanionic vesicles and micelles was prolonged between 10 and 100 times compared to the release of pure drug substance from the gel.

  6. FEASTING BLACK HOLE BLOWS BUBBLES

    NASA Technical Reports Server (NTRS)

    2002-01-01

    A monstrous black hole's rude table manners include blowing huge bubbles of hot gas into space. At least, that's the gustatory practice followed by the supermassive black hole residing in the hub of the nearby galaxy NGC 4438. Known as a peculiar galaxy because of its unusual shape, NGC 4438 is in the Virgo Cluster, 50 million light-years from Earth. These NASA Hubble Space Telescope images of the galaxy's central region clearly show one of the bubbles rising from a dark band of dust. The other bubble, emanating from below the dust band, is barely visible, appearing as dim red blobs in the close-up picture of the galaxy's hub (the colorful picture at right). The background image represents a wider view of the galaxy, with the central region defined by the white box. These extremely hot bubbles are caused by the black hole's voracious eating habits. The eating machine is engorging itself with a banquet of material swirling around it in an accretion disk (the white region below the bright bubble). Some of this material is spewed from the disk in opposite directions. Acting like high-powered garden hoses, these twin jets of matter sweep out material in their paths. The jets eventually slam into a wall of dense, slow-moving gas, which is traveling at less than 223,000 mph (360,000 kph). The collision produces the glowing material. The bubbles will continue to expand and will eventually dissipate. Compared with the life of the galaxy, this bubble-blowing phase is a short-lived event. The bubble is much brighter on one side of the galaxy's center because the jet smashed into a denser amount of gas. The brighter bubble is 800 light-years tall and 800 light-years across. The observations are being presented June 5 at the American Astronomical Society meeting in Rochester, N.Y. Both pictures were taken March 24, 1999 with the Wide Field and Planetary Camera 2. False colors were used to enhance the details of the bubbles. The red regions in the picture denote the hot gas

  7. Identification of CFC and HCFC substitutes for blowing polyurethane foam insulation products. Final report, September 1993-November 1994

    SciTech Connect

    Howard, P.H.; Tunkel, J.L.; Banerjee, S.

    1995-10-01

    The report gives results of a cooperative effort to identify chlorofluorocarbon (CFC) and hydrochlorofluorocarbon (HCFC) substitutes for blowing polyurethane foam insulation products. More than 100 chemicals have been identified and ranked as polyurethane foam blowing agent candidates. The systematic investigation involved the analysis of vapor thermal conductivity predictive models and utilizing this methodology to identify and screen potential new foam blowing agents. Collection of physical/chemical properties of the new candidates enabled an overall evaluation. Based on the vapor thermal conductivity, boiling point, and other important properties, the chemical compounds were ranked to identify the most promising new blowing agent candidates. To efficiently evaluate new foam blowing agents, the compounds were placed and evaluated in 14 groups based on chemical structure.

  8. Blow-up: a free lunch?

    PubMed

    Koenderink, Jan; Richards, Whitman; van Doorn, Andrea

    2012-01-01

    We consider operations that change the size of images, either shrinks or blow-ups. Image processing offers numerous possibilities, put at everyone's disposal with such computer programs as Adobe Photoshop. We consider a different class of operations, aimed at immediate visual awareness, rather than pixel arrays. We demonstrate cases of blow-ups that do not sacrifice apparent resolution. This apparent information gain is due to "amodal occlusion."

  9. Blow-up: a free lunch?

    PubMed

    Koenderink, Jan; Richards, Whitman; van Doorn, Andrea

    2012-01-01

    We consider operations that change the size of images, either shrinks or blow-ups. Image processing offers numerous possibilities, put at everyone's disposal with such computer programs as Adobe Photoshop. We consider a different class of operations, aimed at immediate visual awareness, rather than pixel arrays. We demonstrate cases of blow-ups that do not sacrifice apparent resolution. This apparent information gain is due to "amodal occlusion." PMID:23145273

  10. Blow-up: a free lunch?

    PubMed Central

    Koenderink, Jan; Richards, Whitman; van Doorn, Andrea

    2012-01-01

    We consider operations that change the size of images, either shrinks or blow-ups. Image processing offers numerous possibilities, put at everyone's disposal with such computer programs as Adobe Photoshop. We consider a different class of operations, aimed at immediate visual awareness, rather than pixel arrays. We demonstrate cases of blow-ups that do not sacrifice apparent resolution. This apparent information gain is due to “amodal occlusion.” PMID:23145273

  11. PIV Measurements on a Blowing Flap

    NASA Technical Reports Server (NTRS)

    Hutcheson, Florence V.; Stead, Daniel J.

    2004-01-01

    PIV measurements of the flow in the region of a flap side edge are presented for several blowing flap configurations. The test model is a NACA 63(sub 2)-215 Hicks Mod-B main-element airfoil with a half-span Fowler flap. Air is blown from small slots located along the flap side edge on either the top, bottom or side surfaces. The test set up is described and flow measurements for a baseline and three blowing flap configurations are presented. The effects that the flap tip jets have on the structure of the flap side edge flow are discussed for each of the flap configurations tested. The results indicate that blowing air from a slot located along the top surface of the flap greatly weakened the top vortex system and pushed it further off the top surface. Blowing from the bottom flap surface kept the strong side vortex further outboard while blowing from the side surface only strengthened the vortex system or accelerated the merging of the side vortex to the flap top surface. It is concluded that blowing from the top or bottom surfaces of the flap may lead to a reduction of flap side edge noise.

  12. Blowing Snow Over the Antarctic Plateau

    NASA Technical Reports Server (NTRS)

    Mahesh, Ashwin; Eager, Rebecca; Campbell, James R.; Spinhirne, James D.

    2002-01-01

    Studies of blowing snow over Antarctica have been limited greatly by the remoteness and harsh conditions of the region. Space-based observations are also of lesser value than elsewhere, given the similarities between ice clouds and snow-covered surfaces, both at infrared and visible wavelengths. It is only in recent years that routine ground-based observation programs have acquired sufficient data to overcome the gap in our understanding of surface blowing snow. In this paper, observations of blowing snow from visual observers' records as well as ground-based spectral and lidar programs at South Pole station are analyzed to obtain the first climatology of blowing snow over the Antarctic plateau. Occurrence frequencies, correlation with wind direction and speed, typical layer heights, as well as optical depths are determined. Blowing snow is seen in roughly one third of the visual observations and occurs under a narrow range of wind directions. The near-surface layers typically a few hundred meters thick emit radiances similar to those from thin clouds. Because blowing snow remains close to the surface and is frequently present, it will produce small biases in space-borne altimetry; these must be properly estimated and corrected.

  13. Augmentation of maneuver performance by spanwise blowing

    NASA Technical Reports Server (NTRS)

    Erickson, G. E.; Campbell, J. F.

    1977-01-01

    A generalized wind tunnel model was tested to investigate new component concepts utilizing spanwise blowing to provide improved maneuver characteristics for advanced fighter aircraft. Primary emphasis was placed on high angle of attack performance, stability, and control at subsonic speeds. Spanwise blowing on a 44 deg swept trapezoidal wing resulted in leading edge vortex enhancement with subsequent large vortex-induced lift increments and drag polar improvements at the higher angles of attack. Small deflections of a leading edge flap delayed these lift and drag benefits to higher angles of attack. In addition, blowing was more effective at higher Mach numbers. Spanwise blowing in conjunction with a deflected trailing edge flap resulted in lift and drag benefits that exceeded the summation of the effects of each high lift device acting alone. Asymmetric blowing was an effective lateral control device at the higher angles of attack. Spanwise blowing on the wing reduced horizontal tail loading and improved the lateral-directional stability characteristics of a wing-horizontal tail-vertical tail configuration.

  14. Computational analysis of forebody tangential slot blowing

    NASA Technical Reports Server (NTRS)

    Gee, Ken; Agosta-Greenman, Roxana M.; Rizk, Yehia M.; Schiff, Lewis B.; Cummings, Russell M.

    1994-01-01

    An overview of the computational effort to analyze forebody tangential slot blowing is presented. Tangential slot blowing generates side force and yawing moment which may be used to control an aircraft flying at high-angle-of-attack. Two different geometries are used in the analysis: (1) The High Alpha Research Vehicle; and (2) a generic chined forebody. Computations using the isolated F/A-18 forebody are obtained at full-scale wind tunnel test conditions for direct comparison with available experimental data. The effects of over- and under-blowing on force and moment production are analyzed. Time-accurate solutions using the isolated forebody are obtained to study the force onset timelag of tangential slot blowing. Computations using the generic chined forebody are obtained at experimental wind tunnel conditions, and the results compared with available experimental data. This computational analysis compliments the experimental results and provides a detailed understanding of the effects of tangential slot blowing on the flow field about simple and complex geometries.

  15. Ground effects on USB configurations. [Upper Surface Blowing

    NASA Technical Reports Server (NTRS)

    Lan, C. E.

    1979-01-01

    Recent investigations of ground effects on aerodynamic characteristics have been stimulated by the interest in powered-lift STOL airplanes. The ground effects on upper-surface-blowing (USB) configurations may involve change in both the circulation forces and the jet reaction forces. In this note, a theoretical method is proposed for predicting these effects. It is shown that the predicted results agree well with available experimental data. In particular, the wing-alone method is shown to be incapable of predicting the ground effects of USB configurations.

  16. Solution blowing of soy protein fibers.

    PubMed

    Sinha-Ray, S; Zhang, Y; Yarin, A L; Davis, S C; Pourdeyhimi, B

    2011-06-13

    Solution blowing of soy protein (sp)/polymer blends was used to form monolithic nanofibers. The monolithic fibers were blown from blends of soy protein and nylon-6 in formic acid. The sp/nylon-6 ratio achieved in dry monolithic nanofibers formed using solution blowing of the blend was equal to 40/60. In addition, solution blowing of core-shell nanofibers was realized with soy protein being in the core and the supporting polymer in the shell. The shells were formed from nylon-6. The sp/nylon-6 ratio achieved in dry core-shell fibers was 32/68. The nanofibers developed in the present work contain significant amounts of soy protein and hold great potential in various applications of nonwovens.

  17. Your right to blow the whistle.

    PubMed

    Peate, Ian

    The NHS Constitution has now enshrined within it a number of pledges concerning whistle blowing. This comes as a result of a recent Department of Health (DH) public consultation concerning the Constitution and whistle blowing (DH, 2011). Changes to the Constitution will add an expectation that staff should raise concerns at the earliest opportunity. It also pledges that NHS organizations should support staff by ensuring their concerns are fully investigated and that there is someone independent, outside of their team, to speak to. It will aim to add clarity around the existing legal right for staff to raise concerns about safety, malpractice or other wrong doing without suffering any detriment.

  18. Development of polyimide foams with blowing agents

    NASA Technical Reports Server (NTRS)

    Gagliani, John (Inventor); Sorathia, Usman A. K. (Inventor); Lee, Raymond (Inventor)

    1985-01-01

    A method of preparing a polyimide foam which includes the steps of: preparing, foaming, and curing a precursor containing at least one alkyl ester of 3,3'4,4'-benzophenonetetracarboxylic acid; a meta- or para-substituted aromatic diamine; a heterocyclic diamine; an aliphatic diamine; and a solid blowing agent. The blowing agent is added to said precursor in a concentration which is sufficient to effect at least one of the following attributes of the foam: cell size, proportion of open cells, cell density, and indentation load deflection.

  19. 2. GENERAL VIEW OF BLOWING ENGINE HOUSE, LOOKING NORTH; BOILER ...

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

    2. GENERAL VIEW OF BLOWING ENGINE HOUSE, LOOKING NORTH; BOILER HOUSE ON LEFT; BLAST FURNACE, OVENS AND CASTING HOUSE BEYOND. - U.S. Steel Corporation, Clairton Works, Blast Furnace Blowing Engine Building, 400 State Street, Clairton, Allegheny County, PA

  20. Whistle-Blowing Intentions of Prospective Teachers: Education Evidence

    ERIC Educational Resources Information Center

    Gökçe, Asiye Toker

    2013-01-01

    This study investigates whistle-blowing intentions of prospective teachers. Firstly, overall ethical awareness of the participants was examined, and then their underlying ethical reasons of whistle-blowing were investigated. Besides, impact on the intention to blow whistle to internal or external parties offering their job guarantee were searched.…

  1. Whistle Blowing: Implications for Organizational Communication Scholars.

    ERIC Educational Resources Information Center

    Stewart, Lea P.

    Although "whistle blowing" (public protest by employees of management decisions) is being reported with increasing frequency, this paper points out that organizational communication researchers have not examined the phenomenon. The paper offers a review of current literature on the topic and presents a model, drawn from an examination of 51…

  2. Dinural patterns of blowing sand and dust

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The diurnal pattern of blowing sand results from a complex interaction between the sun, the atmosphere, and the sand surface. During the day, solar heating produces thermal instability, which enhances convective mixing of high momentum winds from the upper levels of the atmosphere to the surface la...

  3. Nontraumatic orbital floor fracture after nose blowing.

    PubMed

    Sandhu, Ranjit S; Shah, Akash D

    2016-03-01

    A 40-year-old woman with no history of trauma or prior surgery presented to the emergency department with headache and left eye pain after nose blowing. Noncontrast maxillofacial computed tomography examination revealed an orbital floor fracture that ultimately required surgical repair. There are nontraumatic causes of orbital blowout fractures, and imaging should be obtained irrespective of trauma history. PMID:26973725

  4. Drifting and blowing snow, measurements and modelling

    NASA Astrophysics Data System (ADS)

    Gordon, Mark

    2007-12-01

    Blowing snow is a frequent and significant winter weather event, and there is currently a need for more observations and measurements of blowing snow, especially in arctic and subarctic environments. A camera system has been developed to measure the size and velocity of blowing snow particles. A second camera system has been developed to measure the relative blowing snow density profile near the snow surface. These systems have been used, along with standard meteorological instruments and optical particle counters, during field campaigns at Franklin Bay, NWT, and at Churchill, MB. An electric field mill was also deployed at Franklin Bay. Results demonstrate that the particle diameters follow a Gamma distribution with 103 < d¯ < 172 mum below a height of 0.15 m and 120 < d¯ < 154 mum between 0.2 m and 1.1 m. Within the saltation layer, the mass density can be approximated by a power-law (rhos ∝ z -gamma) with an exponent of gamma ≈ 1.5 for z < 40 mm. Between 40 < z < 100 mm, in the lower suspension layer, the value of the exponent increases to a range of 1.5 < gamma < 8. At greater heights, z > 100 mm, the exponent approaches gamma ≈ l. The height of saltation shows a very weak dependence on the friction velocity, a strong dependence on temperature and relative humidity, and a weak dependence on snow age. Electric field strengths as high as 2000 V m-1 were measured at a height of 0.5 m. A model to determine electric field strength based on the distribution of blowing snow particles shows a weak agreement with measurements. Results suggest the charge is most likely generated due to either fragmentation or asymmetric rubbing, which are both strongly dependent on wind speed. Modelling studies with the Canadian Land Surface Scheme (CLASS) and previous measurements of snow depth at Goose Bay, Hay River, the Beaufort Sea, Franklin Bay, and Resolute demonstrate that blowing snow sublimation can have a substantial effect on snow depth. Adding a blowing snow

  5. Thermodynamic and Experimental Study of the Energetic Cost Involved in the Capture of Carbon Dioxide by Aqueous Mixtures of Commonly Used Primary and Tertiary Amines.

    PubMed

    Arcis, Hugues; Coulier, Yohann; Coxam, Jean-Yves

    2016-01-01

    The capture of carbon dioxide with chemical solvents is one solution to mitigate greenhouse gas emissions from anthropogenic sources and thus tackle climate change. Recent research has been focused on optimizing new kinds of advanced absorbents including aqueous amine blends, but critical downsides such as the large energetic cost involved with the industrial process remain. To address this issue, a better understanding of the energetic interactions existing in solution is necessary. In this paper, we report direct experimental measurements of the energy cost involved in the solvation of CO2 in two aqueous amine blends at different temperatures. The chemical solvents were designed as aqueous mixtures of commonly used primary and tertiary amines to study the influence of the different chemical properties inferred by the amine class. We have also applied a thermodynamic model to represent the energetic effects that take place in solution during CO2 dissolution in these mixtures, where all parameters were taken from previous studies focused on single amine absorbents. The noteworthy agreement observed with the reported experimental heats of absorption and with literature vapor liquid equilibrium properties confirmed the relevance of the underlying molecular mechanisms considered in our model, and suggest that this model would prove useful to investigate CO2 dissolution in other amine blends.

  6. Carcinogenic mixtures.

    PubMed

    Krewski, D; Thomas, R D

    1992-03-01

    Human populations are generally exposed simultaneously to a number of toxicants present in the environment, including complex mixtures of unknown and variable origin. While scientific methods for evaluating the potential carcinogenic risks of pure compounds are relatively well established, methods for assessing the risks of complex mixtures are somewhat less developed. This article provides a report of a recent workshop on carcinogenic mixtures sponsored by the Committee on Toxicology of the U.S. National Research Council, in which toxicological, epidemiological, and statistical approaches to carcinogenic risk assessment for mixtures were discussed. Complex mixtures, such as diesel emissions and tobacco smoke, have been shown to have carcinogenic potential. Bioassay-directed fractionation based on short-term screening test for genotoxicity has also been used in identifying carcinogenic components of mixtures. Both toxicological and epidemiological studies have identified clear interactions between chemical carcinogens, including synergistic effects at moderate to high doses. To date, laboratory studies have demonstrated over 900 interactions involving nearly 200 chemical carcinogens. At lower doses, theoretical arguments suggest that risks may be near additive. Thus, additivity at low doses has been invoked as as a working hypothesis by regulatory authorities in the absence of evidence to the contrary. Future studies of the joint effects of carcinogenic agents may serve to elucidate the mechanisms by which interactions occur at higher doses.

  7. Relationship between Whistle-Blowing and Job Satisfaction and Organizational Loyalty at Schools in Turkey

    ERIC Educational Resources Information Center

    Gokce, Asiye Toker

    2013-01-01

    This paper examines whistle-blowing at schools in Turkey. Firstly, wrongdoings observed by teachers at schools, and their preference for reporting these were analyzed. Then, differences between the teachers, who blew whistle and the others who did not were examined according to the research variables. The study group involved 283 teachers. The…

  8. Culture Shock!! "Lesson" the Blow.

    ERIC Educational Resources Information Center

    Duffin, Ken

    1996-01-01

    Designing, developing, and implementing an electronic document management system involves preparation. Areas to consider when facilitating technological change include staff input and business and customer needs and wants. Further discussion addresses value assessment of document type, providing a pilot system for staff experiment and practice,…

  9. Control of Cavity Resonance Using Steady and Oscillatory Blowing

    NASA Technical Reports Server (NTRS)

    Lamp, Alison M.; Chokani, Ndaona

    1999-01-01

    An experimental study to investigate the effect of steady and oscillatory (with zero net mass flux) blowing on cavity resonance is undertaken. The objective is to study the basic mechanisms of the control of cavity resonance. An actuator is designed and calibrated to generate either steady blowing or oscillatory blowing with A zero net mass flux. The results of the experiment show that both steady and oscillatory blowing are effective, and reduce the amplitude of the dominant resonant mode by 1OdB. The oscillatory blowing is however found to be more superior in that the same effectiveness could be accomplished with a momentum coefficient an order of magnitude smaller than for steady blowing. The experiment also confirms the results of previous computations that suggest the forcing frequency for oscillatory blowing must not be at harmonic frequencies of the cavity resonant modes.

  10. Blow-down and blow-in of Inland`s No. 7 blast furnace

    SciTech Connect

    Ricketts, J.; Quisenberry, P.; Carter, W.

    1995-12-01

    After extensive and detailed planning, a mini-reline of the 13.7 meter No. 7 Blast Furnace was executed in November 1993. The furnace lining had 18 million metric tons of production and the bosh, belly and lower stack lining were being maintained through a scheduled grouting practice. The mini-reline was planned for 33 days and the reline work included (a) replacing the bosh, belly and lower stack alumina lining with graphite brick, (b) gunning the middle and upper stack, (c) rebuilding the furnace top, stove burners and tapholes and (d) minor repairs to other auxiliary equipment. During this 33 day reline period the two 8 meter furnaces could only produce 40% of the normal production requirement, therefore the blow-down, quench, salamander tap and blow-in activities were critical to meeting the planned schedule. The planning of these activities was started in the spring of 1993 and included review of Inland`s past blow-down and blow-in performance as well as bench marking the performance of other large blast furnaces in North America, Japan and Europe. The development of the 1993 procedures focused on opportunities to accelerate the blow-down, quench, salamander tap and blow-in as well as having a clean hearth and stack which could also save time during the demolition phase of the reline. Any time that could be saved in these activities directly translated to an early start-up and more plantwide production. This paper will cover the successful planning and implementation of these activities which resulted in a 2 day reduction in the reline schedule, an accelerated production curve and an earlier than planned use of PCI during blow-in.

  11. Whistle-blowing; Not always a losing game

    SciTech Connect

    Fitzgerald, K.

    1990-12-01

    In this paper five engineers in nuclear power, aerospace, and air-traffic control recount their experiences in following their consciences. Exposing errors or unethical conduct in any occupation is risky, but when engineering judgement is involved, the risks of blowing the whistle acquire an added dimension. A technical decision cannot always be categorized as strictly right or wrong - unlike situations in which an organization is falsifying documents or overcharging for a product. Consequently, the engineer must be convinced of being right and then wait, sometimes years and even decades after lives are lost or millions of dollars are spent, to be proved right or wrong. Frequently, the whistle-blower's career is destroyed in the meantime. In the following cases, which date from the 1970s and 1980s, the whistle-blowers have by now been vindicated to a degree for their actions, though the verdict may not be unanimous. And the careers of the first group may have even benefitted by blowing the whistle.

  12. Blow-in fracture of the orbit.

    PubMed

    Hwang, Kun; Kim, Han Joon; Lee, Hong Sik

    2013-01-01

    We report 2 patients with blow-in fractures of the orbital floor caused by different mechanisms. In a 17-year-old boy, a sudden impact was given to the anterior maxillary wall and caused a depression fracture of a maxilla, yet the infraorbital rim remained intact. We think fragments of the orbital floor were forced into the orbit by a sudden increase in pressure in the maxillary sinus in this patient. In a 51-year-old man, the impact of a force was on the laterosuperior part of the zygoma, which pushed the zygoma medially. These 2 cases represent 2 different mechanisms of blow-in fractures of the orbital floor.

  13. Blow-in fracture of the orbit.

    PubMed

    Hwang, Kun; Kim, Han Joon; Lee, Hong Sik

    2013-01-01

    We report 2 patients with blow-in fractures of the orbital floor caused by different mechanisms. In a 17-year-old boy, a sudden impact was given to the anterior maxillary wall and caused a depression fracture of a maxilla, yet the infraorbital rim remained intact. We think fragments of the orbital floor were forced into the orbit by a sudden increase in pressure in the maxillary sinus in this patient. In a 51-year-old man, the impact of a force was on the laterosuperior part of the zygoma, which pushed the zygoma medially. These 2 cases represent 2 different mechanisms of blow-in fractures of the orbital floor. PMID:24036789

  14. Asian elephants acquire inaccessible food by blowing.

    PubMed

    Mizuno, Kaori; Irie, Naoko; Hiraiwa-Hasegawa, Mariko; Kutsukake, Nobuyuki

    2016-01-01

    Many animals acquire otherwise inaccessible food with the aid of sticks and occasionally water. As an exception, some reports suggest that elephants manipulate breathing through their trunks to acquire inaccessible food. Here, we report on two female Asian elephants (Elephas maximus) in Kamine Zoo, Japan, who regularly blew to drive food within their reach. We experimentally investigated this behaviour by placing foods in inaccessible places. The elephants blew the food until it came within accessible range. Once the food was within range, the elephants were increasingly less likely to blow as the distance to the food became shorter. One subject manipulated her blowing duration based on food distance: longer when the food was distant. These results suggest that the elephants used their breath to achieve goals: that is, they used it not only to retrieve the food but also to fine-tune the food position for easy grasping. We also observed individual differences in the elephants' aptitude for this technique, which altered the efficiency of food acquisition. Thus, we added a new example of spontaneous behaviour for achieving a goal in animals. The use of breath to drive food is probably unique to elephants, with their dexterous trunks and familiarity with manipulating the act of blowing, which is commonly employed for self-comfort and acoustic communication.

  15. Asian elephants acquire inaccessible food by blowing.

    PubMed

    Mizuno, Kaori; Irie, Naoko; Hiraiwa-Hasegawa, Mariko; Kutsukake, Nobuyuki

    2016-01-01

    Many animals acquire otherwise inaccessible food with the aid of sticks and occasionally water. As an exception, some reports suggest that elephants manipulate breathing through their trunks to acquire inaccessible food. Here, we report on two female Asian elephants (Elephas maximus) in Kamine Zoo, Japan, who regularly blew to drive food within their reach. We experimentally investigated this behaviour by placing foods in inaccessible places. The elephants blew the food until it came within accessible range. Once the food was within range, the elephants were increasingly less likely to blow as the distance to the food became shorter. One subject manipulated her blowing duration based on food distance: longer when the food was distant. These results suggest that the elephants used their breath to achieve goals: that is, they used it not only to retrieve the food but also to fine-tune the food position for easy grasping. We also observed individual differences in the elephants' aptitude for this technique, which altered the efficiency of food acquisition. Thus, we added a new example of spontaneous behaviour for achieving a goal in animals. The use of breath to drive food is probably unique to elephants, with their dexterous trunks and familiarity with manipulating the act of blowing, which is commonly employed for self-comfort and acoustic communication. PMID:26541597

  16. Effectiveness of Micro-Blowing Technique in Adverse Pressure Gradients

    NASA Technical Reports Server (NTRS)

    Welch, Gerard E.; Larosiliere, Louis M.; Hwang, Danny P.; Wood, Jerry R.

    2001-01-01

    The impact of the micro-blowing technique (MBT) on the skin friction and total drag of a strut in a turbulent, strong adverse-pressure-gradient flow is assessed experimentally over a range of subsonic Mach numbers (0.3 less than M less than 0.7) and reduced blowing fractions (0 less than or equal to 2F/C (sub f,o) less than or equal to 1.75). The MBT-treated strut is situated along the centerline of a symmetric 2-D diffuser with a static pressure rise coefficient of 0.6. In agreement with presented theory and earlier experiments in zero-pressure-gradient flows, the effusion of blowing air reduces skin friction significantly (e.g., by 60% at reduced blowing fractions near 1.75). The total drag of the treated strut with blowing is significantly lower than that of the treated strut in the limit of zero-blowing; further, the total drag is reduced below that of the baseline (solid-plate) strut, provided that the reduced blowing fractions are sufficiently high. The micro-blowing air is, however, deficient in streamwise momentum and the blowing leads to increased boundary-layer and wake thicknesses and shape factors. Diffuser performance metrics and wake surveys are used to discuss the impact of various levels of micro-blowing on the aerodynamic blockage and loss.

  17. Aging of polyurethane insulation foamed with second- and third-generation blowing agents

    SciTech Connect

    Wilkes, K.E.; Gabbard, W.A.; Weaver, F.J.

    1998-05-01

    Results are presented on two studies of the effect of aging on the apparent thermal conductivity of polyurethane foam insulation for refrigerators. Both studies are cooperative projects between the Oak Ridge National Laboratory and the Appliance Research Consortium. The first study has been ongoing for four years and involves evaluation of second generation blowing agents: HCFC-141b and HCFC-142/22 blend with CFC-11 for comparison. The second study has recently started and involves third generation blowing agents: HFC-134a, HFC-245fa. and cyclopentane with HCFC-141b for comparison. Both studies consist of periodic thermal measurements on panels made with solid steel and/or plastic skins and a core of foam to simulate refrigerator walls, and measurements on thin slices with cut faces to characterize the core foam. Laboratory data are presented on four years of aging of panels containing second generation blowing agents. Preliminary data are presented for the third generation blowing agents. The data on panels are compared with predictions of computer models of foam aging.

  18. Forebody tangential blowing for control at high angles of attack

    NASA Technical Reports Server (NTRS)

    Kroo, I.; Rock, S.; Roberts, L.

    1991-01-01

    A feasibility study to determine if the use of tangential leading edge blowing over the forebody could produce effective and practical control of the F-18 HARV aircraft at high angles of attack was conducted. A simplified model of the F-18 configuration using a vortex-lattice model was developed to obtain a better understanding of basic aerodynamic coupling effects and the influence of forebody circulation on lifting surface behavior. The effect of tangential blowing was estimated using existing wind tunnel data on normal forebody blowing and analytical studies of tangential blowing over conical forebodies. Incorporation of forebody blowing into the flight control system was investigated by adding this additional yaw control and sideforce generating actuator into the existing F-18 HARV simulation model. A control law was synthesized using LQG design methods that would schedule blowing rates as a function of vehicle sideslip, angle of attack, and roll and yaw rates.

  19. Reducing secondary losses by blowing cold air in a turbine

    NASA Technical Reports Server (NTRS)

    Koschel, W.

    1977-01-01

    Local blowing on the profile suction side of the turbine guide wheel blades can be effective in preventing the propagation of secondary flows that is, the transport of casing and hub boundary layers by pressure gradients. Some preliminary results on how the blowing should be accomplished in order to influence the secondary flows in the desired manner are given. The effectiveness of blowing is demonstrated. Blowing is also seen to be more effective than using boundary layer slots as far as diminishing losses in the rim zones is concerned.

  20. Examination of nocturnal blow fly (Diptera: Calliphoridae) oviposition on pig carcasses in mid-Michigan.

    PubMed

    Zurawski, Kristi N; Benbow, M Eric; Miller, James R; Merritt, Richard W

    2009-05-01

    The most common application of forensic entomology involves estimating a portion of the postmortem interval (PMI), which usually assumes that blow flies (Diptera: Calliphoridae) do not oviposit nocturnally. Research objectives were to (1) investigate blow fly nocturnal oviposition in relation to sunrise and sunset in Michigan; (2) evaluate abiotic variables postulated to affect blow fly oviposition; and (3) conduct laboratory experiments testing blow fly activity under complete darkness. In 2006, nocturnal oviposition was evaluated in relation to sunset by exposing pigs to fly colonization at 1-h intervals, beginning 2 h before and ending 2 h after sunset. This test was replicated in 2007; however, replicate pigs were placed in the field 2 h after sunset, and hourly observations were made into the following morning. Oviposition was never observed at night. In a laboratory experiment, Lucilia sericata (Meigen), never oviposited on liver hanging above or placed directly on the ground in a completely dark room, Another dark room laboratory study documented that adult flies launched into the air could not fly. This study documents that the probability of nocturnal oviposition on pig carcasses in Michigan was extremely low to nonexistent. These results should be considered when estimating a portion of the PMI in forensic entomological investigations.

  1. Development of an Automatic Blowing Snow station

    NASA Astrophysics Data System (ADS)

    Nishimura, K.

    2010-12-01

    On the Antarctic ice sheet, strong katabatic winds blow throughout the year and a large but unknown fraction of the snow which falls on it is removed continuously. This constitutes a significant factor in mass and energy balance and is all the more important when predicting the likely effects of global climate change. Further, recent experimental work has indicated that the snowdrift sublimation can lead to significant mass losses during strong winds and can be also an important factor in the surface mass balance of the Antarctic ice sheets. Nishimura and Nemoto (2005) carried out the blowing snow observations at Mizuho station, Antarctica in 2000 with the snow particle counters (SPC) that can sense not only the number of snow particles but also their diameters. SPC worked properly and the data obtained revealed profiles of mass flux and particle size distributions as a function of the friction velocity. However, the SPC requires rather high power supply and the data is stored in PC; it is not always suitable for the unmanned observations under the severe Antarctic conditions. Thus, we have developed a simpler device by measuring the attenuation of the light intensity, which strongly depends on the blowing snow flux. A small wind turbine and a cold-proof buttery were utilized as a power source. Firstly, its performance was tested with comparing the SPC in a cold wind tunnel system and it proved adequately fit for practical use by combining the output of the anemometer. In 2009/2010 winter, three systems have been set at Ishikari, Col du Lac blanc in France, and S17 near Syowa station in Antarctica, and the tests are still continuing.

  2. An Implicit Finite Difference Solution to the Viscous Radiating Shock Layer with Strong Blowing. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Garrett, L. B.

    1971-01-01

    An implicit finite difference scheme is developed for the fully coupled solution of the viscous radiating stagnation line equations, including strong blowing. Solutions are presented for both air injection and carbon phenolic ablation products injection into air at conditions near the peak radiative heating point in an earth entry trajectory from interplanetary return missions. A detailed radiative transport code that accounts for the important radiative exchange processes for gaseous mixtures in local thermodynamic and chemical equilibrium is utilized.

  3. THIRD-GENERATION FOAM BLOWING AGENTS FOR FOAM INSULATION

    EPA Science Inventory

    The report gives results of a study of third-generation blowing agents for foam insulation. (NOTE: the search for third-generation foam blowing agents has led to the realization that, as the number of potential substitutes increases, new concerns, such as their potential to act a...

  4. 74. View of small steam tank used in 'blowing down' ...

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

    74. View of small steam tank used in 'blowing down' or cleaning boilers; in background can be seen the bottom of cylindrical water tank located in setback at southeast corner of blowing engine house. - Sloss-Sheffield Steel & Iron, First Avenue North Viaduct at Thirty-second Street, Birmingham, Jefferson County, AL

  5. Use of cooling tower blow down in ethanol fermentation.

    PubMed

    Rajagopalan, N; Singh, V; Panno, B; Wilcoxon, M

    2010-01-01

    Reducing water consumption in bioethanol production conserves an increasingly scarce natural resource, lowers production costs, and minimizes effluent management issues. The suitability of cooling tower blow down water for reuse in fermentation was investigated as a means to lower water consumption. Extensive chemical characterization of the blow down water revealed low concentrations of toxic elements and total dissolved solids. Fermentation carried out with cooling tower blow down water resulted in similar levels of ethanol and residual glucose as a control study using deionized water. The study noted good tolerance by yeast to the specific scale and corrosion inhibitors found in the cooling tower blow down water. This research indicates that, under appropriate conditions, reuse of blow down water from cooling towers in fermentation is feasible. PMID:21076211

  6. Method for the evaluation of stretch blow molding simulations with free blow trials

    NASA Astrophysics Data System (ADS)

    Zimmer, Johannes; Stommel, Markus

    2013-12-01

    Finite-Element (FE) simulations are a valuable tool to support the analysis and optimization of production processes. In order to achieve realistic simulation results, a consistent simulation set-up followed by an evaluation through experiments is crucial. Stretch Blow Molding (SBM) is a commonly applied forming method to produce thin walled bottles. Polyethylene terephthalate (PET) preforms are biaxially stretched into a closed cavity to form a bottle. In this process the thermo-mechanical material behavior during forming greatly influences the performance of the end product and consequently plays a key role for a reliable process simulation. To ensure a realistic material representation in the simulation model, an adequate material model is calibrated with stress-strain curves from biaxial tests. Thin PET-sheets are stretched under defined temperatures and strain rates. These representative experiments include process simplifications regarding geometry, heating and deformation parameters. Therefore, an evaluation step subsequent to the simulation set-up is inevitable. This paper presents a method for extracting temperature dependent stress-strain-curves from experiments close to the production process which enables the crucial evaluation of a process simulation. In the SBM process, the wall thickness distribution of the bottle refers to the preform deformation over time but does not fully define the thermo-mechanical material behavior. In the presented method, PET-preforms receive thermal treatment with Infrared (IR)-heaters from an SBM-machine and are subsequently inflated into free air (free-blow-trial). An IR-camera is used to obtain the temperature distribution on the preform immediately before blowing. Two high speed cameras are synchronized with a pressure sensor to consequently calculate reliable stress-strain curves at any point on the preform surface. These data is finally compared to results from FE-simulations of the free blow trials.

  7. Upper surface blowing aerodynamic and acoustic characteristics

    NASA Technical Reports Server (NTRS)

    Ryle, D. M., Jr.; Braden, J. A.; Gibson, J. S.

    1977-01-01

    Aerodynamic performance at cruise, and noise effects due to variations in nacelle and wing geometry and mode of operation are studied using small aircraft models that simulate upper surface blowing (USB). At cruise speeds ranging from Mach .50 to Mach .82, the key determinants of drag/thrust penalties are found to be nozzle aspect ratio, boattailing angle, and chordwise position; number of nacelles; and streamlined versus symmetric configuration. Recommendations are made for obtaining favorable cruise configurations. The acoustic studies, which concentrate on the noise created by the jet exhaust flow and its interaction with wing and flap surfaces, isolate several important sources of USB noise, including nozzle shape, exit velocity, and impingement angle; flow pathlength; and flap angle and radius of curvature. Suggestions for lessening noise due to trailing edge flow velocity, flow pathlength, and flow spreading are given, though compromises between some design options may be necessary.

  8. Effect of Pulsed Blowing on Farfield Noise

    NASA Technical Reports Server (NTRS)

    Gaeta, R. J.; Ahuja, K. K.; Hellman, B.; Combier, R.

    2003-01-01

    This portion of the report documents the results of an experimental program, which focused on pulsed blowing from the trailing edge of a CCW. The main objective of this study was to assess whether pulsed blowing resulted in more, less, or the same amount of radiated noise to the farfield. Results show that a reduction in far-field noise of up to 5 dB is measured when pulse flow is compared to steady flow for an equivalent lift configuration. This reduction is in the spectral region associated with the trailing edge jet noise. This result is due to the unique advantage that pulsed flow has over steady flow. For a range of frequencies, more lift is experienced with the same mass flow as the steady case. Thus, for an equivalent lift and slot height, the pulsed system can operate at lower jet velocities, and hence lower jet noise. At low frequencies (below 1 kHz), the pulsed flow configuration generated more noise in the farfield. This is most likely due to the pulsing mechanism itself. Since the high pressure air feeding the pulsing mechanism was first passed through a high performance muffler, it is likely that this increase in not due to upstream valve noise. Most likely, the impulsive component of the air that periodically fills the plenum causes a broadband source that reaches the farfield. Although the benefit of a pulse trailing edge jet is evident from a mass flow usage and jet noise perspective, attention should be paid towards the design of a viable pulsing system. Future research program in this area should concentrate on the development of a "quiet" pulsing device.

  9. African Dust Blows over the Caribbean

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Shuttle astronauts frequently track Saharan dust storms as they blow from north Africa across the Atlantic Ocean. Dust palls blowing from Africa take about a week to cross the Atlantic. Recently, researchers have linked Saharan dust to coral disease, allergic reactions in humans, and red tides. The top photograph, a classic image showing African dust over the Caribbean, was taken at a time when few scientists had considered the possibility. The image was taken by Space Shuttle astronauts on July 11, 1994 (STS065-75-47). This photograph looks southwest over the northern edge of a large trans-Atlantic dust plume that blew off the Sahara desert in Africa. In this view, Caicos Island in the Bahamas and the mountainous spines of Haiti are partly obscured by the dust. Closer to the foreground, (about 26 degrees north latitude), the skies are clear. The lower photograph (STS105-723-7) was taken by Space Shuttle astronauts while docked to the International Space Station on August 19, 2001. The spacecraft is over the Atlantic Ocean at roughly 45oN, 60oW. The astronauts were looking obliquely to the south; the boundaries of the dust plumes can be traced visually by the abrupt change from clear to hazy atmosphere-the hazy line marks the northern edge of the dust pall near the Caribbean. Images provided by the Earth Sciences and Image Analysis Laboratory at Johnson Space Center. Additional images taken by astronauts and cosmonauts can be viewed at the NASA-JSC Gateway to Astronaut Photography of Earth.

  10. Simulation of the Two Stages Stretch-Blow Molding Process: Infrared Heating and Blowing Modeling

    SciTech Connect

    Bordival, M.; Schmidt, F. M.; Le Maoult, Y.; Velay, V.

    2007-05-17

    In the Stretch-Blow Molding (SBM) process, the temperature distribution of the reheated perform affects drastically the blowing kinematic, the bottle thickness distribution, as well as the orientation induced by stretching. Consequently, mechanical and optical properties of the final bottle are closely related to heating conditions. In order to predict the 3D temperature distribution of a rotating preform, numerical software using control-volume method has been developed. Since PET behaves like a semi-transparent medium, the radiative flux absorption was computed using Beer Lambert law. In a second step, 2D axi-symmetric simulations of the SBM have been developed using the finite element package ABAQUS registered . Temperature profiles through the preform wall thickness and along its length were computed and applied as initial condition. Air pressure inside the preform was not considered as an input variable, but was automatically computed using a thermodynamic model. The heat transfer coefficient applied between the mold and the polymer was also measured. Finally, the G'sell law was used for modeling PET behavior. For both heating and blowing stage simulations, a good agreement has been observed with experimental measurements. This work is part of the European project ''APT{sub P}ACK'' (Advanced knowledge of Polymer deformation for Tomorrow's PACKaging)

  11. Liquid mixtures involving hydrogenated and fluorinated chains: (p, ρ, T, x) surface of (ethanol + 2,2,2-trifluoroethanol), experimental and simulation.

    PubMed

    Duarte, Pedro; Silva, Marcelo; Rodrigues, Djêide; Morgado, Pedro; Martins, Luís F G; Filipe, Eduardo J M

    2013-08-22

    The effect of mixing hydrogenated and fluorinated molecules that simultaneously interact through strong hydrogen bonding was investigated: (ethanol + 2,2,2-trifluoroethanol) binary mixtures were studied both experimentally and by computer simulation. This mixture displays a very complex behavior when compared with mixtures of hydrogenated alcohols and mixtures of alkanes and perfluoroalkanes. The excess volumes are large and positive (unlike those of mixtures of hydrogenated alchools), while the excess enthalpies are large and negative (contrasting with those of mixtures of alkanes and perfluoroalkanes). In this work, the liquid density of the mixtures was measured as a function of composition, at several temperatures from 278.15 to 353.15 K and from atmospheric pressure up to 70 MPa. The corresponding excess molar volumes, compressibilities, and expansivities were calculated over the whole (p, ρ, T, x) surface. In order to obtain molecular level insight, the behavior of the mixture was also studied by molecular dynamics simulation, using the OPLS-AA force field. The combined analysis of the experimental and simulation results indicates that the peculiar phase behavior of this system stems from a balance between the weak dispersion forces between the hydrogenated and fluorinated groups and a preferential hydrogen bond between ethanol and 2,2,2-trifluoroethanol. Additionally, it was observed that a 25% reduction of the F-H dispersive interaction in the simulations brings agreement between the experimental and simulated excess enthalpy but produces no effect in the excess volumes. This reveals that the main reason causing the volume increase in these systems is not entirely related to the weak dispersive interactions, as it is usually assumed, and should thus be connected to the repulsive part of the intermolecular potential.

  12. Control of VR-7 Dynamic Stall by Strong Steady Blowing

    NASA Technical Reports Server (NTRS)

    Weaver, D.; McAlister, K. W.; Tso, J.

    2004-01-01

    An experiment was performed in a water tunnel on a Boeing-Vertol VR-7 airfoil to study the effects of tangential blowing over the upper surface. Blowing was applied at the quarter-chord location during sinusoidal pitching oscillations described by alpha = alpha(sub m) + 10 deg sin omega t. Results were obtained for a Reynolds number of 1 x 10(exp 5), mean angles of 10 and 15 deg, reduced frequencies ranging from 0.005 to 0.15, and blowing rates from C(sub mu) = 0.16 to 0.66. Unsteady lift, drag, and pitching moment loads are reported, along with fluorescent-dye flow visualizations. Strong steady blowing was found to prevent the bursting of the leading-edge separation bubble at several test points. When this occurred, the lift was increased significantly, stall was averted, and the shape of the moment response showed a positive damping in pitch. In almost all cases, steady blowing reduced the hysteresis amplitudes present in the loads, but the benefits diminished as the reduced frequency and mean angle of oscillation increased. A limited number of pulsed blowing cases indicated that for low blowing rates, the greatest gains were achieved at F(sup +) = 0.9.

  13. Carburetor mixture control apparatus

    SciTech Connect

    Dalke, A.E.

    1983-11-29

    A mixture control device is disclosed for automatically controlling the air to fuel mixture of a conventional carburetor involving a plurality of sloped radial vanes circumferentially located within the annulus formed by the booster venturi and the venturi tube. By inducing significant centrifugal motion in the air passing outside the booster venturi the problems associated with fuel to air mixture changes associated with changes in elevation and changes in seasonal temperatures are alleviated.

  14. INTERIOR VIEW SHOWING QBOP FURNACE IN BLOW. OXYGEN AND NATURAL ...

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

    INTERIOR VIEW SHOWING Q-BOP FURNACE IN BLOW. OXYGEN AND NATURAL GAS ARE BLOWN INTO THE FURNACE THROUGH THE TUYERES TO CHARGE 460,000 LBS. OF HOT METAL, 100,000 LBS. OF SCRAP WITH 30,000 LBS. OF LIME. BLOW TIME IS 16 MINUTES. THE TIME TO BLOW AND TAP THE FURNACES OF THE RESULTING 205,000 TONS OF STEEL AND SLAG IS 35 MINUTES. - U.S. Steel, Fairfield Works, Q-Bop Furnace, North of Valley Road & West of Ensley, Pleasant Grove Road, Fairfield, Jefferson County, AL

  15. 46 CFR 162.018-5 - Blow-down adjustment and popping tolerance.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 6 2011-10-01 2011-10-01 false Blow-down adjustment and popping tolerance. 162.018-5... Compressed Gas § 162.018-5 Blow-down adjustment and popping tolerance. (a) Safety relief valves shall be so... adjustible blow-down construction shall be adjusted to close after blowing down not more than 5 percent...

  16. 46 CFR 162.018-5 - Blow-down adjustment and popping tolerance.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 6 2010-10-01 2010-10-01 false Blow-down adjustment and popping tolerance. 162.018-5... Compressed Gas § 162.018-5 Blow-down adjustment and popping tolerance. (a) Safety relief valves shall be so... adjustible blow-down construction shall be adjusted to close after blowing down not more than 5 percent...

  17. 46 CFR 162.018-5 - Blow-down adjustment and popping tolerance.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 6 2012-10-01 2012-10-01 false Blow-down adjustment and popping tolerance. 162.018-5... Compressed Gas § 162.018-5 Blow-down adjustment and popping tolerance. (a) Safety relief valves shall be so... adjustible blow-down construction shall be adjusted to close after blowing down not more than 5 percent...

  18. 46 CFR 162.018-5 - Blow-down adjustment and popping tolerance.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 6 2014-10-01 2014-10-01 false Blow-down adjustment and popping tolerance. 162.018-5... Compressed Gas § 162.018-5 Blow-down adjustment and popping tolerance. (a) Safety relief valves shall be so... adjustable blow-down construction shall be adjusted to close after blowing down not more than 5 percent...

  19. 46 CFR 162.018-5 - Blow-down adjustment and popping tolerance.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 6 2013-10-01 2013-10-01 false Blow-down adjustment and popping tolerance. 162.018-5... Compressed Gas § 162.018-5 Blow-down adjustment and popping tolerance. (a) Safety relief valves shall be so... adjustible blow-down construction shall be adjusted to close after blowing down not more than 5 percent...

  20. 79. View inside blowing engine room looking down walkway with ...

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

    79. View inside blowing engine room looking down walkway with engine flywheels at left. - Sloss-Sheffield Steel & Iron, First Avenue North Viaduct at Thirty-second Street, Birmingham, Jefferson County, AL

  1. 40. LOOKING EAST IN BLOW ENGINE HOUSE No. 2 AT ...

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

    40. LOOKING EAST IN BLOW ENGINE HOUSE No. 2 AT CASING FOR CENTRIFUGAL TURBOBLOWER No. 3. (Jet Lowe) - U.S. Steel Duquesne Works, Blast Furnace Plant, Along Monongahela River, Duquesne, Allegheny County, PA

  2. 37. INTERIOR VIEW OF BLOW ENGINE HOUSE No. 2 LOOKING ...

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

    37. INTERIOR VIEW OF BLOW ENGINE HOUSE No. 2 LOOKING EAST. CENTRIFUGAL TURBOBLOWER No. 1 IN FOREGROUND. (Jet Lowe) - U.S. Steel Duquesne Works, Blast Furnace Plant, Along Monongahela River, Duquesne, Allegheny County, PA

  3. Rocking Boats, Blowing Whistles, and Teaching Speech Communication.

    ERIC Educational Resources Information Center

    Redding, W. Charles

    1985-01-01

    Examines and defends two forms of dissent in organizational life, "rocking boats" and "blowing whistles." Suggests ways speech communication teachers can prepare students to cope with the organizational world. (PD)

  4. Polypropylenes foam consisting of thermally expandable microcapsule as blowing agent

    NASA Astrophysics Data System (ADS)

    Jeoung, Sun Kyung; Hwang, Ye Jin; Lee, Hyun Wook; Kwak, Sung Bok; Han, In-Soo; Ha, Jin Uk

    2016-03-01

    The structure of thermally expandable microcapsule (TEMs) is consisted of a thermoplastic shell which is filled with liquid hydrocarbon at core. The shell of TEMs becomes soft when the temperature is higher than boiling temperature of liquid hydrocarbon. The shell of TEMs is expanded under the high temperature because the inner pressure of TEMs is increased by vaporization of hydrocarbon core. Therefore, the TEMs are applicable for blowing agents and light weight fillers. In this research, we fabricated the polypropylene (PP) foam by using the TEMs and chemical blowing agents and compared to their physical properties. The density of the specimen was decreased when the contents of chemical blowing agents and TEMs were increased. In addition, the mechanical properties (i.e. tensile strength and impact strength) of specimens were deteriorated with increasing amount of chemical blowing agents and TEMs. However, PP foam produced with TEMs showed higher impact strength than the one with the chemical blowing agent. In order to clarify the dependence of impact strength of PP foam as the blowing agent, the morphology difference of the PP foams was investigated. Expanding properties of PP foams produced with TEMs was changed with TEMs content of PP foams. Processing conditions also influenced the mechanical properties of PP foam containing TEMs.

  5. Transport properties in mixtures involving carbon dioxide at low and moderate density: test of several intermolecular potential energies and comparison with experiment

    NASA Astrophysics Data System (ADS)

    Moghadasi, Jalil; Yousefi, Fakhri; Papari, Mohammad Mehdi; Faghihi, Mohammad Ali; Mohsenipour, Ali Asghar

    2009-09-01

    It is the purpose of this paper to extract unlike intermolecular potential energies of five carbon dioxide-based binary gas mixtures including CO2-He, CO2-Ne, CO2-Ar, CO2-Kr, and CO2-Xe from viscosity data and compare the calculated potentials with other models potential energy reported in literature. Then, dilute transport properties consisting of viscosity, diffusion coefficient, thermal diffusion factor, and thermal conductivity of aforementioned mixtures are calculated from the calculated potential energies and compared with literature data. Rather accurate correlations for the viscosity coefficient of afore-cited mixtures embracing the temperature range 200 K < T < 3273.15 K is reproduced from the present unlike intermolecular potentials energy. Our estimated accuracies for the viscosity are to within ±2%. In addition, the calculated potential energies are used to present smooth correlations for other transport properties. The accuracies of the binary diffusion coefficients are of the order of ±3%. Finally, the unlike interaction energy and the calculated low density viscosity have been employed to calculate high density viscosities using Vesovic-Wakeham method.

  6. PLIF Visualization of Active Control of Hypersonic Boundary Layers Using Blowing

    NASA Technical Reports Server (NTRS)

    Bathel, Brett F.; Danehy, Paul M.; Inman, Jennifer A.; Alderfer, David W.; Berry, Scott A.

    2008-01-01

    Planar laser-induced fluorescence (PLIF) imaging was used to visualize the boundary layer flow on a 1/3-scale Hyper-X forebody model. The boundary layer was perturbed by blowing out of orifices normal to the model surface. Two blowing orifice configurations were used: a spanwise row of 17-holes spaced at 1/8 inch, with diameters of 0.020 inches and a single-hole orifice with a diameter of 0.010 inches. The purpose of the study was to visualize and identify laminar and turbulent structures in the boundary layer and to make comparisons with previous phosphor thermography measurements of surface heating. Jet penetration and its influence on the boundary layer development was also examined as was the effect of a compression corner on downstream boundary layer transition. Based upon the acquired PLIF images, it was determined that global surface heating measurements obtained using the phosphor thermography technique provide an incomplete indicator of transitional and turbulent behavior of the corresponding boundary layer flow. Additionally, the PLIF images show a significant contribution towards transition from instabilities originating from the underexpanded jets. For this experiment, a nitric oxide/nitrogen mixture was seeded through the orifices, with nitric oxide (NO) serving as the fluorescing gas. The experiment was performed in the 31-inch Mach 10 Air Tunnel at NASA Langley Research Center.

  7. Modeling variable blowing effects in the turbulent hypersonic boundary layer

    NASA Technical Reports Server (NTRS)

    Vanosdol, John G.

    1992-01-01

    Studies of the effects of variable blowing in turbulent hypersonic boundary layers are presented. Numerical calculations of the skin friction and surface heat transfer rates are compared to the experimental measurements of Holden (1990) for a slender cone at zero angle of attack in steady flows at Mach numbers of 11 and 13. An analysis of the transpiration feed system of the cone model was performed and showed that the blowing rate could be variable along the cone surface. This effect is confirmed by internal pressure measurements which were taken inside the cone model. The blowing rates are recalibrated using the internal gauge readings and used as the wall boundary condition for a compressible turbulent boundary layer calculation using the low Reynolds number k-epsilon model of Chien (1982). At low blowing rates, the boundary layer calculations indicate that a situation where both the effects of suction and blowing are present within the same flow. The results show excellent qualitative prediction of the experimental data.

  8. The effects of local blowing perturbations on thermal turbulent structures

    NASA Astrophysics Data System (ADS)

    Liu, Can; Araya, Guillermo; Leonardi, Stefano; Castillo, Luciano

    2013-11-01

    Blowing is an active flow control technique with several industrial applications, particularly in film cooling of turbine blades. In the past, the effects of localized blowing have been mostly analyzed on the velocity field and its influence of the flow parameters and turbulence structures (Krogstad and Kourakine, 2000). However, little literature can be found on the effects of blowing on the coherent thermal structures. In the present study, an incompressible turbulent channel flow with given steady blowing at the wall is simulated via DNS by means of five spanwise holes. The Reynolds number based on the friction velocity and half channel height is approximately Re = 394 and the molecular Prandtl number is Pr = 0.71. Temperature is considered a passive scalar with isothermal conditions at the wall. Different blowing amplitudes and perturbing angles (with respect to the streamwise direction) are applied to find out their effects on the turbulent thermal structures by means of a two-point correlation analysis. In addition, local reduction and increase of drag are connected to vorticity. The corresponding influence of perturbing amplitudes and angles on the energy budget of thermal fluctuations and turbulent Prandtl numbers are also shown and discussed.

  9. Numerical study of delta wing leading edge blowing

    NASA Technical Reports Server (NTRS)

    Yeh, David; Tavella, Domingo; Roberts, Leonard

    1988-01-01

    Spanwise and tangential leading edge blowing as a means of controlling the position and strength of the leading edge vortices are studied by numerical solution of the three-dimensional Navier-Stokes equations. The leading edge jet is simulated by defining a permeable boundary, corresponding to the jet slot, where suitable boundary conditions are implemented. Numerical results are shown to compare favorably with experimental measurements. It is found that the use of spanwise leading edge blowing at moderate angle of attack magnifies the size and strength of the leading edge vortices, and moves the vortex cores outboard and upward. The increase in lift primarily comes from the greater nonlinear vortex lift. However, spanwise blowing causes earlier vortex breakdown, thus decreasing the stall angle. The effects of tangential blowing at low to moderate angles of attack tend to reduce the pressure peaks associated with leading edge vortices and to increase the suction peak around the leading edge, so that the integrated value of the surface pressure remains about the same. Tangential leading edge blowing in post-stall conditions is shown to re-establish vortical flow and delay vortex bursting, thus increasing C sub L sub max and stall angle.

  10. Finite time blow-up in nonlinear suspension bridge models

    NASA Astrophysics Data System (ADS)

    Radu, Petronela; Toundykov, Daniel; Trageser, Jeremy

    2014-12-01

    This paper settles a conjecture by Gazzola and Pavani [10] regarding solutions to the fourth order ODE w+kw″+f(w)=0 which arises in models of traveling waves in suspension bridges when k>0. Under suitable assumptions on the nonlinearity f and initial data, we demonstrate blow-up in finite time. The case k≤0 was first investigated by Gazzola et al., and it is also handled here with a proof that requires less differentiability on f. Our approach is inspired by Gazzola et al. and exhibits the oscillatory mechanism underlying the finite-time blow-up. This blow-up is nonmonotone, with solutions oscillating to higher amplitudes over shrinking time intervals. In the context of bridge dynamics this phenomenon appears to be a consequence of mutually-amplifying interactions between vertical displacements and torsional oscillations.

  11. An experimental study of massive blowing from a nosetip during Jovian entry

    NASA Technical Reports Server (NTRS)

    Holden, M. S.

    1981-01-01

    The fluid dynamic structure and stability of the boundary layer and shock layer ahead of a highly blowing heat shield in an environment simulating entry into the Jovian atmosphere were investigated. The experimental studies were conducted in the Calspan 96 in shock tunnel with a freestream of a H2/He mixture at Mach numbers above 10. Measurements of heat transfer and pressure were made on the porous model surface, and high-speed schlieren photography was used to examine the structure and stability of the shock layer. Results are presented which show how the heat transfer and shock layer stability vary for gases of different molecular weights for a range of Reynolds numbers and mass-addition rates.

  12. Understanding the bacterial communities of hard cheese with blowing defect.

    PubMed

    Bassi, Daniela; Puglisi, Edoardo; Cocconcelli, Pier Sandro

    2015-12-01

    The environment of hard cheese encourages bacterial synergies and competitions along the ripening process, which might lead in defects such as clostridial blowing. In this study, Denaturing Gradient Gel Electrophoresis (DGGE), a quantitative Clostridium tyrobutyricum PCR and next-generation Illumina-based sequencing of 16S rRNA gene were applied to study 83 Grana Padano spoiled samples. The aim was to investigate the community of clostridia involved in spoilage, the ecological relationships with the other members of the cheese microbiota, and the effect of lysozyme. Three main genera were dominant in the analysed cheeses, Lactobacillus, Streptococcus and Clostridium, and the assignment at the species level was of 94.3% of 4,477,326 high quality sequences. C. tyrobutyricum and C. butyricum were the most prevalent clostridia. Hierarchical clustering based on the abundance of bacterial genera, revealed three main clusters: one characterized by the highest proportion of Clostridium, a second where Lactobacillus was predominant and the last, dominated by Streptococcus thermophilus. Ecological relationships among species were found: cheeses characterized by an high abundance of S. thermophilus and L. rhamnosus were spoiled by C. tyrobutyricum while, when L. delbrueckii was the most abundant Lactobacillus, C. butyricum was the dominant spoiling species. Lysozyme also shaped the bacterial community, reducing C. tyrobutyricum in favour of C. butyricum. Moreover, this preservative increased the proportion of L. delbrueckii and obligate heterofermentative lactobacilli and lowered L. helveticus and non-starter species, such as L. rhamnosus and L. casei.

  13. Understanding the bacterial communities of hard cheese with blowing defect.

    PubMed

    Bassi, Daniela; Puglisi, Edoardo; Cocconcelli, Pier Sandro

    2015-12-01

    The environment of hard cheese encourages bacterial synergies and competitions along the ripening process, which might lead in defects such as clostridial blowing. In this study, Denaturing Gradient Gel Electrophoresis (DGGE), a quantitative Clostridium tyrobutyricum PCR and next-generation Illumina-based sequencing of 16S rRNA gene were applied to study 83 Grana Padano spoiled samples. The aim was to investigate the community of clostridia involved in spoilage, the ecological relationships with the other members of the cheese microbiota, and the effect of lysozyme. Three main genera were dominant in the analysed cheeses, Lactobacillus, Streptococcus and Clostridium, and the assignment at the species level was of 94.3% of 4,477,326 high quality sequences. C. tyrobutyricum and C. butyricum were the most prevalent clostridia. Hierarchical clustering based on the abundance of bacterial genera, revealed three main clusters: one characterized by the highest proportion of Clostridium, a second where Lactobacillus was predominant and the last, dominated by Streptococcus thermophilus. Ecological relationships among species were found: cheeses characterized by an high abundance of S. thermophilus and L. rhamnosus were spoiled by C. tyrobutyricum while, when L. delbrueckii was the most abundant Lactobacillus, C. butyricum was the dominant spoiling species. Lysozyme also shaped the bacterial community, reducing C. tyrobutyricum in favour of C. butyricum. Moreover, this preservative increased the proportion of L. delbrueckii and obligate heterofermentative lactobacilli and lowered L. helveticus and non-starter species, such as L. rhamnosus and L. casei. PMID:26338123

  14. Blow-up of solutions of strongly dissipative generalized Klein-Gordon equations

    NASA Astrophysics Data System (ADS)

    Korpusov, Maxim O.

    2013-04-01

    We study the question of sufficient conditions for blow-up of solutions of a model initial-boundary value problem. We use a modified form of Levine's method to obtain sufficient conditions for blow-up in finite time.

  15. IDENTIFICATION OF CFC AND HCFC SUBSTITUTES FOR BLOWING POLYURETHANE FOAM INSULATION PRODUCTS

    EPA Science Inventory

    The report gives results of a cooperative effort to identiry chlorofluorocarbons and hydrochlorofluorocarbon substitutes for blowing polyurethane foam insulation products. The substantial ongoing effort is identifying third-generation blowing agets for polyurethane foams to repla...

  16. SYMBIOTIC STAR BLOWS BUBBLES INTO SPACE

    NASA Technical Reports Server (NTRS)

    2002-01-01

    A tempestuous relationship between an unlikely pair of stars may have created an oddly shaped, gaseous nebula that resembles an hourglass nestled within an hourglass. Images taken with Earth-based telescopes have shown the larger, hourglass-shaped nebula. But this picture, taken with NASA's Hubble Space Telescope, reveals a small, bright nebula embedded in the center of the larger one (close-up of nebula in inset). Astronomers have dubbed the entire nebula the 'Southern Crab Nebula' (He2-104), because, from ground-based telescopes, it looks like the body and legs of a crab. The nebula is several light-years long. The possible creators of these shapes cannot be seen at all in this Wide Field and Planetary Camera 2 image. It's a pair of aging stars buried in the glow of the tiny, central nebula. One of them is a red giant, a bloated star that is exhausting its nuclear fuel and is shedding its outer layers in a powerful stellar wind. Its companion is a hot, white dwarf, a stellar zombie of a burned-out star. This odd duo of a red giant and a white dwarf is called a symbiotic system. The red giant is also a Mira Variable, a pulsating red giant, that is far away from its partner. It could take as much as 100 years for the two to orbit around each other. Astronomers speculate that the interaction between these two stars may have sparked episodic outbursts of material, creating the gaseous bubbles that form the nebula. They interact by playing a celestial game of 'catch': as the red giant throws off its bulk in a powerful stellar wind, the white dwarf catches some of it. As a result, an accretion disk of material forms around the white dwarf and spirals onto its hot surface. Gas continues to build up on the surface until it sparks an eruption, blowing material into space. This explosive event may have happened twice in the 'Southern Crab.' Astronomers speculate that the hourglass-shaped nebulae represent two separate outbursts that occurred several thousand years apart

  17. Diastereomeric mixture of calophyllic acid and isocalophyllic acid stimulates glucose uptake in skeletal muscle cells: involvement of PI-3-kinase- and ERK1/2-dependent pathways.

    PubMed

    Prasad, Janki; Maurya, Chandan Kumar; Pandey, Jyotsana; Jaiswal, Natasha; Madhur, Gaurav; Srivastava, Arvind Kumar; Narender, Tadigoppula; Tamrakar, Akhilesh Kumar

    2013-05-01

    The diastereomeric mixture of calophyllic acid and isocalophyllic acid (F015) isolated from the leaves of Calophyllum inophyllum was investigated for the metabolic effect on glucose transport in skeletal muscle cells. In L6 myotubes, F015 dose-dependently stimulated glucose uptake by increasing translocation of glucose transporter4 (GLUT4) to plasma membrane without affecting their gene expression. The effects on glucose uptake were additive to insulin. Inhibitors analyses revealed that F015-induced glucose uptake was dependent on the activation of phosphatidylinositol-3-kinase (PI-3-K) and extracellular signal-regulated kinases 1 and 2 (ERK1/2), while independent to the activation of 5'AMP-activated kinase (AMPK). F015 significantly increased the phosphorylation of AKT, AS160 and ERK1/2, account for the augmented glucose transport capacity in L6 myotubes. Furthermore, F015 improved glucose tolerance and enhanced insulin sensitivity in skeletal muscle of dexamethasone-induced insulin resistant mice. Our findings demonstrate that F015 activates glucose uptake in skeletal muscle cells through PI-3-K- and EKR1/2-dependent mechanisms and can be a potential lead for the management of diabetes and obesity.

  18. Whistle-Blowing and the Code of Silence in Police Agencies: Policy and Structural Predictors

    ERIC Educational Resources Information Center

    Rothwell, Gary R.; Baldwin, J. Norman

    2007-01-01

    This article reports the findings from a study that investigates predictors of police willingness to blow the whistle and police frequency of blowing the whistle on seven forms of misconduct. It specifically investigates the capacity of nine policy and structural variables to predict whistle-blowing. The results indicate that two variables, a…

  19. 67. View looking east up walkway between blowing engine house ...

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

    67. View looking east up walkway between blowing engine house at left and boilers at right showing base of stack for boilers No. 5 and 6. - Sloss-Sheffield Steel & Iron, First Avenue North Viaduct at Thirty-second Street, Birmingham, Jefferson County, AL

  20. Seismotectonic implications of sand blows in the southern Mississippi Embayment

    USGS Publications Warehouse

    Cox, R.T.; Hill, A.A.; Larsen, D.; Holzer, T.; Forman, S.L.; Noce, T.; Gardner, C.; Morat, J.

    2007-01-01

    We explore seismically-induced sand blows from the southern Mississippi Embayment and their implications in resolving the question of near or distal epicentral source region. This was accomplished using aerial photography, field excavations, and cone penetration tests. Our analysis shows that three sand blow fields exhibit a distinct chronology of strong ground motion for the southern embayment: (1) The Ashley County, Arkansas sand blow field, near the Arkansas/Louisiana state border, experienced four Holocene sand venting episodes; (2) to the north, the Desha County field experienced at least three episodes of liquefaction; and (3) the Lincoln-Jefferson Counties field experienced at least one episode. Cone penetration tests (CPT) conducted in and between the sand blow fields suggest that the fields may not be distal liquefaction associated with New Madrid seismic zone earthquakes but rather are likely associated with strong earthquakes on local faults. This conclusion is consistent with the differences in timing of the southern embayment sand venting episodes and those in the New Madrid seismic zone. These results suggest that active tectonism and strong seismicity in intraplate North America may not be localized at isolated weak spots, but rather widespread on fault systems that are favorably oriented for slip in the contemporary stress field. ?? 2006 Elsevier B.V. All rights reserved.

  1. Reduction of airfoil trailing edge noise by trailing edge blowing

    NASA Astrophysics Data System (ADS)

    Gerhard, T.; Erbslöh, S.; Carolus, T.

    2014-06-01

    The paper deals with airfoil trailing edge noise and its reduction by trailing edge blowing. A Somers S834 airfoil section which originally was designed for small wind turbines is investigated. To mimic realistic Reynolds numbers the boundary layer is tripped on pressure and suction side. The chordwise position of the blowing slot is varied. The acoustic sources, i.e. the unsteady flow quantities in the turbulent boundary layer in the vicinity of the trailing edge, are quantified for the airfoil without and with trailing edge blowing by means of a large eddy simulation and complementary measurements. Eventually the far field airfoil noise is measured by a two-microphone filtering and correlation and a 40 microphone array technique. Both, LES-prediction and measurements showed that a suitable blowing jet on the airfoil suction side is able to reduce significantly the turbulence intensity and the induced surface pressure fluctuations in the trailing edge region. As a consequence, trailing edge noise associated with a spectral hump around 500 Hz could be reduced by 3 dB. For that a jet velocity of 50% of the free field velocity was sufficient. The most favourable slot position was at 90% chord length.

  2. Individual and Situational Correlates of Whistle-Blowing.

    ERIC Educational Resources Information Center

    Miceli, Marcia P.; Near, Janet P.

    1988-01-01

    Analyzed archival survey data from observers of wrongdoing in 22 organizations. Found whistle-blowing more likely when observers held professional positions, had positive reactions to their work, had longer service, were recently recognized for good performance, were male, were members of larger work groups, and were employed by organizations…

  3. Proteus mirabilis interkingdom swarming signals attract blow flies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Flies transport specific bacteria with their larvae which provides a wider range of nutrients for those bacteria. Our hypothesis was that this symbiotic interaction may depend on interkingdom signaling. We obtained Proteus mirabilis from the salivary glands of the blow fly Lucilia sericat. This s...

  4. Blow fly responses to semiochemicals produced by decaying carcasses.

    PubMed

    Johansen, H; Solum, M; Knudsen, G K; Hågvar, E B; Norli, H R; Aak, A

    2014-03-01

    Volatiles from mouse carcasses in decay stages ranging from fresh to 33 days old were used to investigate oriented flight and landings in male and female blow flies of Calliphora vicina Robineau-Desvoidy (Diptera: Calliphoridae). Oriented flight increased significantly from 36% towards fresh carcasses to 68%, 61% and 65% towards carcasses aged 3 days, 6 days and 9 days, respectively. Carcasses aged 20 days and 33 days were significantly less attractive, achieving 51% and 41% attraction, respectively. No differences emerged between the sexes in oriented flight, but a significant increase in female landings at the most attractive carcasses was observed. Headspace collections from the different stages of decay showed a succession in the volatile profile emitted from the carcasses and identified nine chemicals which peak in quantity in concurrence with the most attractive stages of decay. Three of these chemicals also showed dose-response effects as indicated by a significant correlation between the amount present and the proportion of flies responding. Blow flies are important pests and efficient traps are needed. The significant interaction between fly sex and carcass age highlights behavioural differences between male and female blow flies which can be exploited in blow fly trapping. Three new volatile chemicals, butylated hydroxyl toluene, 3-hydroxy-2-butanone and nonanal, emitted from dead mice are suggested as potential attractants.

  5. Preparation of zein fibers using solution blow spinning method

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Zein fibers were successfully fabricated via solution blow spinning (SBS) using acetic acid as solvent. Surface tension, viscosity and modulus of zein solutions were respectively determined by force tensiometer and rheometer. Increases of these properties were observed with an increase of concentrat...

  6. PLA fibers with antimicrobial properties developed by solution blow spinning

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The present work reports on the development and characterization of novel Poly(lactic acid) hybrid fibers with antimicrobial properties produced by solution blow spinning. This technique presents additional advantages over conventional electrospinning, such as reduced cost and higher rate of fiber p...

  7. 42. NORTHEAST VIEW OF BLOW ENGINE HOUSE No. 3, WITH ...

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

    42. NORTHEAST VIEW OF BLOW ENGINE HOUSE No. 3, WITH FILTER CAKE HOSUE IN CENTER FOREGROUND, AND EVAPORATIVE WASTE WATER TREATMENT COOLING TOWER TO THE LEFT. (Jet Lowe) - U.S. Steel Duquesne Works, Blast Furnace Plant, Along Monongahela River, Duquesne, Allegheny County, PA

  8. 39. SOUTHERN INTERIOR VIEW OF BLOW ENGINE HOUSE No. 2 ...

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

    39. SOUTHERN INTERIOR VIEW OF BLOW ENGINE HOUSE No. 2 WITH THE STEAM TURBINE BLADES OF AXIAL TURBOBLOWER No. 4. THE STATOR BLADES OF AXIAL TURBOBLOWER No. 4. THE STATOR BLADES AT THE COMPRESSOR END OF AXIAL TURBOBLOWER No. 4 ARE IN THE BACKGROUND. (Martin Stupich) - U.S. Steel Duquesne Works, Blast Furnace Plant, Along Monongahela River, Duquesne, Allegheny County, PA

  9. CR-39 track etching and blow-up method

    DOEpatents

    Hankins, Dale E.

    1987-01-01

    This invention is a method of etching tracks in CR-39 foil to obtain uniformly sized tracks. The invention comprises a step of electrochemically etching the foil at a low frequency and a "blow-up" step of electrochemically etching the foil at a high frequency.

  10. HOLOCENE AND LATE PLEISTOCENE(? ) EARTHQUAKE-INDUCED SAND BLOWS IN COASTAL SOUTH CAROLINA.

    USGS Publications Warehouse

    Obermeier, S.F.; Jacobson, R.B.; Powars, D.S.; Weems, R.E.; Hallbick, D.C.; Gohn, G.S.; Markewich, H.W.

    1986-01-01

    Multiple generations of prehistoric sand blows, interpreted as earthquake induced, have been discovered throughout coastal South Carolina. These sand blows extend far beyond 1886 earthquake induced sand blows, in sediments having approximately the same liquefaction susceptibility. The seismic source zone for the prehistoric sand blows is unknown. The different distributions of prehistoric and 1886 sand blows have two possible explanations: (1) moderate to strong earthquakes originated in different seismic source locations through time or (2) at least one earthquake much stronger than the 1886 event also originated from the same seismic source as the 1886 earthquake.

  11. Delta wing vortex manipulation using pulsed and steady blowing during ramp pitching

    NASA Technical Reports Server (NTRS)

    Moreira, J.; Johari, H.

    1995-01-01

    The effectiveness of steady and pulsed blowing as a method of controlling delta wing vortices during ramp pitching has been investigated in flow visualization experiments conducted in a water tunnel. The recessed angled spanwise blowing technique was utilized for vortex manipulation. This technique was implemented on a beveled 60 delta wing using a pair of blowing ports located beneath the vortex core at 40% chord. The flow was injected primarily in the spanwise direction but was also composed of a component normal to the wing surface. The location of vortex burst was measured as a function of blowing intensity and pulsing frequency under static conditions, and the optimum blowing case was applied at three different wing pitching rates. Experimental results have shown that, when the burst location is upstream of the blowing port, pulsed blowing delays vortex breakdown in static and dynamic cases. Dynamic tests verified the existence of a hysteresis effect and demonstrated the improvements offered by pulsed blowing over both steady blowing and no-blowing scenarios. The application of blowing, at the optimum pulsing frequency, made the vortex breakdown location comparable in static and ramp pitch-up conditions.

  12. Blow-by gas processing arrangement for automotive internal combustion engines

    SciTech Connect

    Anno, N.; Arai, T.

    1987-07-21

    This patent describes a blow-by gas processing arrangement for an internal combustion engine, comprising: a cylinder block having a chamber for collecting a blow-by gas, a blow-by gas passage communicating with the chamber, and spaced journal walls for supporting a crankshaft; a relatively large oil mist separating passage defined in the cylinder block and laterally extending into one of the journal walls beyond the blow-by gas passage. The oil mist separates passage communicating with the blow-by gas passage for preliminary separating an oil mist from the blow-by gas supplied from the chamber; an oil separator communicating with the oil mist separates passage for separating an oil mist from the blow-by gas supplied from the oil mist separating passage; and a PCV valve is connected to the oil mist separator; and an intake manifold connected to the PCV valve.

  13. Sustained prediction ability of net analyte preprocessing methods using reduced calibration sets. Theoretical and experimental study involving the spectrophotometric analysis of multicomponent mixtures.

    PubMed

    Goicoechea, H C; Olivieri, A C

    2001-07-01

    A newly developed multivariate method involving net analyte preprocessing (NAP) was tested using central composite calibration designs of progressively decreasing size regarding the multivariate simultaneous spectrophotometric determination of three active components (phenylephrine, diphenhydramine and naphazoline) and one excipient (methylparaben) in nasal solutions. Its performance was evaluated and compared with that of partial least-squares (PLS-1). Minimisation of the calibration predicted error sum of squares (PRESS) as a function of a moving spectral window helped to select appropriate working spectral ranges for both methods. The comparison of NAP and PLS results was carried out using two tests: (1) the elliptical joint confidence region for the slope and intercept of a predicted versus actual concentrations plot for a large validation set of samples and (2) the D-optimality criterion concerning the information content of the calibration data matrix. Extensive simulations and experimental validation showed that, unlike PLS, the NAP method is able to furnish highly satisfactory results when the calibration set is reduced from a full four-component central composite to a fractional central composite, as expected from the modelling requirements of net analyte based methods.

  14. Intraguild predation influences oviposition behavior of blow flies (Diptera: Calliphoridae).

    PubMed

    Galindo, Luciane A; Moral, Rafael A; Moretti, Thiago C; Godoy, Wesley A C; Demétrio, Clarice G B

    2016-05-01

    The objective of the present study was to determine whether blow flies (Diptera: Calliphoridae) are able to identify larvae of an intraguild predator species in the substrate and avoid laying eggs there. Blow flies oviposited in traps with different treatments: substrate only and substrate with larvae of Chrysomya albiceps (Wiedemann, 1819), Chrysomya megacephala (Fabricius, 1794), or Chrysomya putoria (Wiedemann, 1830). Ch. megacephala, Ch. putoria, and Lucilia eximia (Wiedemann, 1819) avoided laying eggs in the trap containing Ch. albiceps larvae. Cochliomyia macellaria (Fabricius, 1775) did not oviposit differently in each substrate but had overall low abundance. The prevalence of species on corpses may be influenced by the ability of the species to detect the presence of other species, mainly predators. In this sense, intraguild predation may result in misinterpretations of a crime scene and should be considered when assessing the minimum postmortem interval. PMID:26888288

  15. Effect of Blowing on Boundary Layer of Scarf Inlet

    NASA Technical Reports Server (NTRS)

    Gerhold, Carl H.; Clark, Lorenzo R.

    2004-01-01

    When aircraft operate in stationary or low speed conditions, airflow into the engine accelerates around the inlet lip and pockets of turbulence that cause noise and vibration can be ingested. This problem has been encountered with engines equipped with the scarf inlet, both in full scale and in model tests, where the noise produced during the static test makes it difficult to assess the noise reduction performance of the scarf inlet. NASA Langley researchers have implemented boundary layer control in an attempt to reduce the influence of the flow nonuniformity in a 12-in. diameter model of a high bypass fan engine mounted in an anechoic chamber. Static pressures and boundary layer profiles were measured in the inlet and far field acoustic measurements were made to assess the effectiveness of the blowing treatment. The blowing system was found to lack the authority to overcome the inlet distortions. Methods to improve the implementation of boundary layer control to reduce inlet distortion are discussed.

  16. Intraguild predation influences oviposition behavior of blow flies (Diptera: Calliphoridae).

    PubMed

    Galindo, Luciane A; Moral, Rafael A; Moretti, Thiago C; Godoy, Wesley A C; Demétrio, Clarice G B

    2016-05-01

    The objective of the present study was to determine whether blow flies (Diptera: Calliphoridae) are able to identify larvae of an intraguild predator species in the substrate and avoid laying eggs there. Blow flies oviposited in traps with different treatments: substrate only and substrate with larvae of Chrysomya albiceps (Wiedemann, 1819), Chrysomya megacephala (Fabricius, 1794), or Chrysomya putoria (Wiedemann, 1830). Ch. megacephala, Ch. putoria, and Lucilia eximia (Wiedemann, 1819) avoided laying eggs in the trap containing Ch. albiceps larvae. Cochliomyia macellaria (Fabricius, 1775) did not oviposit differently in each substrate but had overall low abundance. The prevalence of species on corpses may be influenced by the ability of the species to detect the presence of other species, mainly predators. In this sense, intraguild predation may result in misinterpretations of a crime scene and should be considered when assessing the minimum postmortem interval.

  17. Orbital emphysema: nose blowing leading to a blown orbit.

    PubMed

    Jawaid, M Saad

    2015-01-01

    A 32-year-old woman with a painful swelling around the right eye few hours after blowing her nose, presented to the accident and emergency department. There was no associated history of facial trauma. Examination revealed a grossly swollen right eye and palpable subcutaneous emphysema. The patient's visual acuity and eye movements were normal. A CT scan of the orbit confirmed orbital emphysema secondary to a fracture of the floor of the orbit into the maxillary sinus, as a result of increased intranasal pressure during nose blowing. The patient was admitted and managed conservatively with antibiotics. She made a full recovery with complete resolution of all her symptoms. A nasal bone fracture was also seen on CT scan and even though the patient could not recall any history of facial trauma, it was an incidental finding. PMID:26516251

  18. Stator Loading Measurements Behind a Fan With Trailing Edge Blowing

    NASA Technical Reports Server (NTRS)

    Waitz, Ian A.

    2000-01-01

    The problem of aircraft noise pollution around airports has become increasingly important as those areas have become more densely populated. Currently, the removal of older noisier aircraft from operation is reducing noise levels around airports; however, with air traffic projected to increase by about 5% over the next decade the number of commercial aircraft operating in the world is expected to be about 17,700 by the year 2007. To keep noise levels around airports from increasing as a result of traffic increases, it is important to investigate new methods of noise reduction. The objective of this work is to provide a better understanding of the effects that trailing edge blowing has on stator unsteady loading. This is done by presenting flowfield and stator loading data from experiments conducted with and without trailing edge blowing.

  19. Sex determination mechanisms in the Calliphoridae (blow flies).

    PubMed

    Scott, M J; Pimsler, M L; Tarone, A M

    2014-01-01

    The Calliphoridae or blow flies are a family of insects that occupy diverse habitats and perform important ecological roles, particularly the decomposition of animal remains. Some Calliphoridae species are also important in the forensic sciences, in agriculture (e.g. as livestock pests) and in medicine (e.g. maggot therapy). Calliphoridae provide striking examples in support of the hypothesis that sex determination regulatory gene hierarchies evolve in the reverse order, with the gene at the top being the most recently added. Unlike the model fly Drosophila melanogaster, where sex is determined by the number of X chromosomes, in the Australian sheep blow fly (Lucilia cuprina) sex is determined by a Y-linked male-determining gene (M). A different regulatory system appears to operate in the hairy maggot blow fly (Chrysomya rufifacies) where the maternal genotype determines sex. It is hypothesized that females heterozygous for a dominant female-determining factor (F/f) produce only female offspring and homozygous f/f females produce only sons. The bottom of the regulatory hierarchy appears to be the same in D. melanogaster and L. cuprina, with sex-specific splicing of doublesex transcripts being controlled by the female-specific Transformer (TRA) protein. We discuss a model that has been proposed for how tra transcripts are sex-specifically spliced in calliphorids, which is very different from D. melanogaster.

  20. COMPLEX MIXTURES AND GROUNDWATER QUALITY

    EPA Science Inventory

    Experience has shown that many soil and ground-water contamination problems involve complex mixtures of chemicals. his manuscript identifies and discusses, in a generic sense, some of the important processes which must be considered when dealing with complex mixtures in the subsu...

  1. Spatial and temporal variations of blowing dust events in the Taklimakan Desert

    NASA Astrophysics Data System (ADS)

    Yang, Xinghua; Shen, Shuanghe; Yang, Fan; He, Qing; Ali, Mamtimin; Huo, Wen; Liu, Xinchun

    2016-08-01

    The Taklimakan Desert is the source of most blowing dust events in China. However, previous studies of sandstorms in this region have not included data from the inner desert because of the difficulty in making observations in this area. In this study, the spatial and temporal variations of blowing dust events, including sandstorms and blowing sand, and its relations with climatic parameters in the Taklimakan Desert were analyzed using data from ten desert-edge meteorological stations during 1961 to 2010 and two inner-desert meteorological stations during 1988 to 1990, 1996 to 2010, and 1992 to 2010. The results identified two regions (Pishan-Hotan-Minfeng and Xiaotang-Tazhong) where blowing dust events occur on average more than 80 days per year. The regions with the highest occurrence of sandstorms, blowing sand, and blowing dust events were different, with sandstorms centered in the north of the desert (Xiaotang, 46.9 days), whereas the central location for blowing sand (Pishan, 86.4 days) and blowing dust events (Minfeng, 113.5 days) activity was located at the southwestern and southern edges of the desert, respectively. The occurrence of sandstorms generally decreased from 1961 to 2010, while the occurrence of blowing sand increased from 1961 to 1979 and then generally decreased. The temporal variation of blowing dust events was mainly affected by the occurrence of strong wind and daily temperature, with average correlation coefficients of 0.46 and -0.41 for these variables across the whole desert.

  2. Analysis of tangential slot blowing on F/A-18 isolated forebody

    NASA Technical Reports Server (NTRS)

    Gee, K.; Rizk, Y.; Schiff, L.

    1994-01-01

    Generation of significant side forces and yawing moments on an F/A-18 fuselage through tangential slot blowing is analyzed using computational fluid dynamics. The effects of freestream Mach number, jet exit conditions, jet length, and jet location are studied. The effects of over- and under-blowing on force and moment production are analyzed. Non-time-accurate solutions are obtained to determine the steady-state side forces, yawing moments, and surface pressure distributions generated by tangential slot blowing. Time-accurate solutions are obtained to study the force onset time lag of tangential slot blowing. Comparison with available experimental data from full-scale wind tunnel and sub-scale wind tunnel tests are made. This computational analysis complements the experimental results and provides a detailed understanding of the effects of tangential slot blowing on the flow field about the isolated F/A-18 forebody. Additionally, it extends the slot-blowing database to transonic maneuvering Mach numbers.

  3. Computational Analysis of Forebody Tangential Slot Blowing on the F/A-18

    NASA Technical Reports Server (NTRS)

    Gee, Ken; Rizk, Yehia M.; Schiff, Lewis B.; Kutler, Paul (Technical Monitor)

    1994-01-01

    An overview of the computational effort to analyze forebody tangential slot blowing for use on the F/A-18 aircraft is presented. Tangential slot blowing generates side force and yawing moment which may be used to control the aircraft flying at high angle of attack. Computations using the isolated forebody are obtained at full-scale wind tunnel test conditions for direct comparison with available experimental data. The effects of jet exit conditions, jet length, and jet location are also studied using the isolated forebody. In addition, these computations are used to predict the effect of slot blowing at transonic maneuvering flight conditions. The effects of over- and under-blowing on force and moment production are analyzed. Non-time-accurate solutions are obtained to determine the steady-state side force and yawing moments generated by tangential slot blowing. Time-accurate solutions are obtained to study the force onset time lag of tangential slot blowing. The effect of blowing on the burst point location are then analyzed by obtaining computations using the aircraft geometry, which includes the wing, empennage, and faired-over inlets. The effect of blowing on the buffet loads on the vertical tails are analyzed using time-accurate computations. Comparison with available experimental data from full-scale wind tunnel and sub-scale wind tunnel tests are made. This computational analysis compliments the experimental results and provides a detailed understanding of the effects of tangential slot blowing on the flow field about the F/A-18.

  4. A One-Dimensional Global-Scaling Erosive Burning Model Informed by Blowing Wall Turbulence

    NASA Technical Reports Server (NTRS)

    Kibbey, Timothy P.

    2014-01-01

    A derivation of turbulent flow parameters, combined with data from erosive burning test motors and blowing wall tests results in erosive burning model candidates useful in one-dimensional internal ballistics analysis capable of scaling across wide ranges of motor size. The real-time burn rate data comes from three test campaigns of subscale segmented solid rocket motors tested at two facilities. The flow theory admits the important effect of the blowing wall on the turbulent friction coefficient by using blowing wall data to determine the blowing wall friction coefficient. The erosive burning behavior of full-scale motors is now predicted more closely than with other recent models.

  5. Controlled vortical flow on delta wings through unsteady leading edge blowing

    NASA Technical Reports Server (NTRS)

    Lee, K. T.; Roberts, Leonard

    1990-01-01

    The vortical flow over a delta wing contributes an important part of the lift - the so called nonlinear lift. Controlling this vortical flow with its favorable influence would enhance aircraft maneuverability at high angle of attack. Several previous studies have shown that control of the vortical flow field is possible through the use of blowing jets. The present experimental research studies vortical flow control by applying a new blowing scheme to the rounded leading edge of a delta wing; this blowing scheme is called Tangential Leading Edge Blowing (TLEB). Vortical flow response both to steady blowing and to unsteady blowing is investigated. It is found that TLEB can redevelop stable, strong vortices even in the post-stall angle of attack regime. Analysis of the steady data shows that the effect of leading edge blowing can be interpreted as an effective change in angle of attack. The examination of the fundamental time scales for vortical flow re-organization after the application of blowing for different initial states of the flow field is studied. Different time scales for flow re-organization are shown to depend upon the effective angle of attack. A faster response time can be achieved at angles of attack beyond stall by a suitable choice of the initial blowing momentum strength. Consequently, TLEB shows the potential of controlling the vortical flow over a wide range of angles of attack; i.e., in both for pre-stall and post-stall conditions.

  6. Low-Speed Fan Noise Reduction With Trailing Edge Blowing

    NASA Technical Reports Server (NTRS)

    Sutliff, Daniel L.; Tweedt, Daniel L.; Fite, E. Brian; Envia, Edmane

    2002-01-01

    An experimental proof-of-concept test was conducted to demonstrate reduction of rotor-stator interaction noise through rotor-trailing edge blowing. The velocity deficit from the viscous wake of the rotor blades was reduced by injecting air into the wake from a trailing edge slot. Composite hollow rotor blades with internal flow passages were designed based on analytical codes modeling the internal flow. The hollow blade with interior guide vanes creates flow channels through which externally supplied air flows from the root of the blade to the trailing edge. The impact of the rotor wake-stator interaction on the acoustics was also predicted analytically. The Active Noise Control Fan, located at the NASA Glenn Research Center, was used as the proof- of-concept test bed. In-duct mode and farfield directivity acoustic data were acquired at blowing rates (defined as mass supplied to trailing edge blowing system divided by fan mass flow) ranging from 0.5 to 2.0 percent. The first three blade passing frequency harmonics at fan rotational speeds of 1700 to 1900 rpm were analyzed. The acoustic tone power levels (PWL) in the inlet and exhaust were reduced 11.5 and -0.1, 7.2 and 11.4, 11.8 and 19.4 PWL dB, respectively. The farfield tone power levels at the first three harmonics were reduced 5.4, 10.6, and 12.4 dB PWL. At selected conditions, two-component hotwire and stator vane unsteady surface pressures were acquired. These measurements illustrate the physics behind the noise reduction.

  7. Modeling of Droplet Generation in a Top Blowing Steelmaking Process

    NASA Astrophysics Data System (ADS)

    Rout, Bapin Kumar; Brooks, Geoff; Subagyo; Rhamdhani, M. Akbar; Li, Zushu

    2016-08-01

    Quantification of metal droplets ejected due to impinging gas jet on the surface of liquid metal is an important parameter for the understanding and for the modeling of the refining kinetics of reactions in slag-metal emulsion zone. In the present work, a numerical study has been carried out to critically examine the applicability of droplet generation rate correlation previously proposed by Subagyo et al. on the basis of dimensionless blowing number (N B). The blowing number was re-evaluated at the impingement point of jet with taking into account the temperature effect of change in density and velocity of the gas jet. The result obtained from the work shows that the modified blowing number N B,T at the furnace temperature of 1873 K (1600 °C) is approximately double in magnitude compared to N B calculated by Subagyo and co-workers. When N B,T has been employed to the Subagyo's empirical correlation for droplet generation, a wide mismatch is observed between the experimental data obtained from cold model and hot model experiments. The reason for this large deviation has been investigated in the current study, and a theoretical approach to estimate the droplet generation rate has been proposed. The suitability of the proposed model has been tested by numerically calculating the amount of metals in slag. The study shows that the weight of metals in emulsion falls in the range of 0 to 21 wt pct of hot metal weight when droplet generation rate has been calculated at ambient furnace temperature of 1873 K (1600 °C).

  8. An implicit finite-difference solution to the viscous shock layer, including the effects of radiation and strong blowing

    NASA Technical Reports Server (NTRS)

    Garrett, L. B.; Smith, G. L.; Perkins, J. N.

    1972-01-01

    An implicit finite-difference scheme is developed for the fully coupled solution of the viscous, radiating stagnation-streamline equations, including strong blowing. Solutions are presented for both air injection and injection of carbon-phenolic ablation products into air at conditions near the peak radiative heating point in an earth entry trajectory from interplanetary return missions. A detailed radiative-transport code that accounts for the important radiative exchange processes for gaseous mixtures in local thermodynamic and chemical equilibrium is utilized in the study. With minimum number of assumptions for the initially unknown parameters and profile distributions, convergent solutions to the full stagnation-line equations are rapidly obtained by a method of successive approximations. Damping of selected profiles is required to aid convergence of the solutions for massive blowing. It is shown that certain finite-difference approximations to the governing differential equations stabilize and improve the solutions. Detailed comparisons are made with the numerical results of previous investigations. Results of the present study indicate lower radiative heat fluxes at the wall for carbonphenolic ablation than previously predicted.

  9. Blow-up and control of marginally separated boundary layers.

    PubMed

    Braun, Stefan; Kluwick, Alfred

    2005-05-15

    Interactive solutions for steady two-dimensional laminar marginally separated boundary layers are known to exist up to a critical value Gamma(c) of the controlling parameter (e.g. the angle of attack of a slender airfoil) Gamma only. Here, we investigate three-dimensional unsteady perturbations of such boundary layers, assuming that the basic flow is almost critical, i.e. in the limit Gamma(c)-Gamma-->0. It is then shown that the interactive equations governing such perturbations simplify significantly, allowing, among others, a systematic study of the blow-up phenomenon observed in earlier investigations and the optimization of devices used in boundary-layer control.

  10. Implementation of a Blowing Boundary Condition in the LAURA Code

    NASA Technical Reports Server (NTRS)

    Thompson, Richard a.; Gnoffo, Peter A.

    2008-01-01

    Preliminary steps toward modeling a coupled ablation problem using a finite-volume Navier-Stokes code (LAURA) are presented in this paper. Implementation of a surface boundary condition with mass transfer (blowing) is described followed by verification and validation through comparisons with analytic results and experimental data. Application of the code to a carbon-nosetip ablation problem is demonstrated and the results are compared with previously published data. It is concluded that the code and coupled procedure are suitable to support further ablation analyses and studies.

  11. Genomic approach to studying nutritional requirements of Clostridium tyrobutyricum and other Clostridia causing late blowing defects.

    PubMed

    Storari, Michelangelo; Kulli, Sandra; Wüthrich, Daniel; Bruggmann, Rémy; Berthoud, Hélène; Arias-Roth, Emmanuelle

    2016-10-01

    Clostridium tyrobutyricum is the main microorganism responsible for the late blowing defect in hard and semi-hard cheeses, causing considerable economic losses to the cheese industry. Deeper knowledge of the metabolic requirements of this microorganism can lead to the development of more effective control approaches. In this work, the amino acids and B vitamins essential for sustaining the growth of C. tyrobutyricum were investigated using a genomic approach. As the first step, the genomes of four C. tyrobutyricum strains were analyzed for the presence of genes putatively involved in the biosynthesis of amino acids and B vitamins. Metabolic pathways could be reconstructed for all amino acids and B vitamins with the exception of biotin (vitamin B7) and folate (vitamin B9). The biotin pathway was missing the enzyme amino-7-oxononanoate synthase that catalyzes the condensation of pimeloyl-ACP and l-alanine to 8-amino-7-oxononanoate. In the folate pathway, the missing genes were those coding for para-aminobenzoate synthase and aminodeoxychorismate lyase enzymes. These enzymes are responsible for the conversion of chorismate into para-aminobenzoate (PABA). Two C. tyrobutyircum strains whose genome was analyzed in silico as well as other 10 strains isolated from cheese were tested in liquid media to confirm these observations. 11 strains showed growth in a defined liquid medium containing biotin and PABA after 6-8 days of incubation. No strain showed growth when only one or none of these compounds were added, confirming the observations obtained in silico. Furthermore, the genome analysis was extended to genomes of single strains of other Clostridium species potentially causing late blowing, namely Clostridium beijerinckii, Clostridium sporogenes and Clostridium butyricum. Only the biotin biosynthesis pathway was incomplete for C. butyricum and C. beijerincki. In contrast, C. sporogenes showed missing enzymes in biosynthesis pathways of several amino acids as well

  12. Coupling dynamic blow down and pool evaporation model for LNG.

    PubMed

    Woodward, John L

    2007-02-20

    Treating the dynamic effects of accidental discharges of liquefied natural gas (LNG) is important for realistic predictions of pool radius. Two phenomena have important influence on pool spread dynamics, time-varying discharge (blow down) and pool ignition. Time-varying discharge occurs because a punctured LNG tanker or storage tank drains with a decreasing liquid head and decreasing head-space pressure. Pool ignition increases the evaporation rate of a pool and consequently decreases the ultimate pool area. This paper describes an approach to treat these phenomena in a dynamic pool evaporation model. The pool evaporation model developed here has two separate regimes. Early in the spill, momentum forces dominate and the pool spreads independently of pool evaporation rate and the corresponding heat transfer rate. After the average pool depth drops below a minimum value, momentum forces are largely dissipated and the thin edges of the pool completely evaporate, so pool area is established by the heat transfer rate. The maximum extent of a burning pool is predicted to be significantly less than that of an unignited pool because the duration of the first regime is reduced by higher heat transfer rates. The maximum extent of an LNG pool is predicted to be larger upon accounting for blow down compared with using a constant average discharge rate. However, the maximum pool extent occurs only momentarily before retreating. PMID:17184912

  13. Adaptive Suction and Blowing for Twin-Tail Buffet Control

    NASA Technical Reports Server (NTRS)

    Kandil, Osama A.; Yang, Zhi

    1999-01-01

    Adaptive active flow control for twin-tail buffet alleviation is investigated. The concept behind this technique is to place control ports on the tail outer and inner surfaces with flow suction or blowing applied through these ports in order to minimize the pressure difference across the tail. The suction or blowing volume flow rate from each port is proportional to the pressure difference across the tail at this location. A parametric study of the effects of the number and location of these ports on the buffet response is carried out. The computational model consists of a sharp-edged delta wing of aspect ratio one and swept-back flexible twin tail with taper ratio of 0.23. This complex multidisciplinary problem is solved sequentially using three sets of equations for the fluid flow, aeroelastic response and grid deformation, using a dynamic multi-block grid structure. The computational model is pitched at 30 deg angle of attack. The freestream Mach number and Reynolds number are 0.3 and 1.25 million, respectively. The model is investigated for the inboard position of the twin tails, which corresponds to a separation distance between the twin tails of 33% of the wing span. Comparison of the time history and power spectral density responses of the tails for various distributions of the control ports are presented and discussed.

  14. Gas Blowing: Mass Transfer in Gas and Melt

    NASA Astrophysics Data System (ADS)

    Sortland, Øyvind Sunde; Tangstad, Merete

    2014-09-01

    Metallurgical routes for solar grade silicon production are being developed as alternatives to chemical processes for their potential to achieve cost reductions, increased production volume, and reduced environmental and safety concerns. An important challenge in the development of metallurgical routes relates to the higher impurity concentrations in the silicon product, particularly for boron and other elements that are not efficiently segregated in solidification techniques. The reactive gas refining process is studied for its potential to remove boron below the solar grade silicon target concentration in a single step by blowing steam and hydrogen gas jets onto the melt surface. Boron in a silicon melt is extracted to HBO gas in parallel to active oxidation of silicon. The literature is not unified regarding the rate determining step in this process. Relevant theories and equations for gas blowing in induction furnaces are combined and used to explain mass transfer in experiments. Mass transfer in the melt and gas is investigated by comparing resistance and induction heating of the melt, and varying gas flow rate, crucible diameter, diameter of the gas lance, and the position of the gas lance above the melt surface. The rate of boron removal is found to increase with increasing gas flow rate and crucible diameter. A relatively high fraction of the reactive gas is utilized in the process, and supply of steam in the bulk gas is the only identified rate determining step.

  15. Numerical Analysis of Film Cooling at High Blowing Ratio

    NASA Technical Reports Server (NTRS)

    El-Gabry, Lamyaa; Heidmann, James; Ameri, Ali

    2009-01-01

    Computational Fluid Dynamics is used in the analysis of a film cooling jet in crossflow. Predictions of film effectiveness are compared with experimental results for a circular jet at blowing ratios ranging from 0.5 to 2.0. Film effectiveness is a surface quantity which alone is insufficient in understanding the source and finding a remedy for shortcomings of the numerical model. Therefore, in addition, comparisons are made to flow field measurements of temperature along the jet centerline. These comparisons show that the CFD model is accurately predicting the extent and trajectory of the film cooling jet; however, there is a lack of agreement in the near-wall region downstream of the film hole. The effects of main stream turbulence conditions, boundary layer thickness, turbulence modeling, and numerical artificial dissipation are evaluated and found to have an insufficient impact in the wake region of separated films (i.e. cannot account for the discrepancy between measured and predicted centerline fluid temperatures). Analyses of low and moderate blowing ratio cases are carried out and results are in good agreement with data.

  16. Solution blow-up for a class of parabolic equations with double nonlinearity

    SciTech Connect

    Korpusov, Maxim O

    2013-03-31

    We consider a class of parabolic-type equations with double nonlinearity and derive sufficient conditions for finite time blow-up of its solutions in a bounded domain under the homogeneous Dirichlet condition. To prove the solution blow-up we use a modification of Levine's method. Bibliography: 13 titles.

  17. Awareness and Ethical Orientation of Alternatively Certified Prospective Teachers to Intention for Whistle Blowing

    ERIC Educational Resources Information Center

    Toker Gokce, Asiye

    2013-01-01

    This study inquires whistle blowing intentions of alternatively certified prospective teachers, investigating their moral reasoning to blow the whistle. Specifically three hypotheses were tested: Overall ethical awareness of the alternatively certified prospective teachers is high; the participants will identify reasons related to philosophical…

  18. Solution blow-up for a class of parabolic equations with double nonlinearity

    NASA Astrophysics Data System (ADS)

    Korpusov, Maxim O.

    2013-03-01

    We consider a class of parabolic-type equations with double nonlinearity and derive sufficient conditions for finite time blow-up of its solutions in a bounded domain under the homogeneous Dirichlet condition. To prove the solution blow-up we use a modification of Levine's method. Bibliography: 13 titles.

  19. Characteristics of Organizational Climate and Perceived Wrongdoing Associated with Whistle-Blowing Decisions.

    ERIC Educational Resources Information Center

    Miceli, Marcia P.; Near, Janet P.

    1985-01-01

    Employees of 15 organizations (N=8,600) completed questionnaires concerning whistle-blowing. Discriminant analysis revealed that organization members who had observed alleged wrongdoing were more likely to blow the whistle if they had convincing evidence of wrongdoing, if the wrongdoing were serious, and if it directly affected them. (Author/BL)

  20. Comparison of nasal swabs with nose blowing for community-based pneumococcal surveillance of healthy children.

    PubMed

    Leach, Amanda Jane; Stubbs, Elizabeth; Hare, Kim; Beissbarth, Jemima; Morris, Peter Stanley

    2008-06-01

    The nasopharynx (NP) is the preferred site for detection of Streptococcus pneumoniae in young children, but NP sampling is not well tolerated. We compared nose blowing with paired nasal swabs. The sensitivity of nose blowing was 46% (95% confidence interval [CI] 38 to 56%), which increased to 94% (95% CI, 85 to 98%) for children with visible secretions.

  1. A Basic Study on Countermeasure Against Aerodynamic Force Acting on Train Running Inside Tunnel Using Air Blowing

    NASA Astrophysics Data System (ADS)

    Suzuki, Masahiro; Nakade, Koji

    A basic study of flow controls using air blowing was conducted to reduce unsteady aerodynamic force acting on trains running in tunnels. An air blowing device is installed around a model car in a wind tunnel. Steady and periodic blowings are examined utilizing electromagnetic valves. Pressure fluctuations are measured and the aerodynamic force acting on the car is estimated. The results are as follows: a) The air blowing allows reducing the unsteady aerodynamic force. b) It is effective to blow air horizontally at the lower side of the car facing the tunnel wall. c) The reduction rate of the unsteady aerodynamic force relates to the rate of momentum of the blowing to that of the uniform flow. d) The periodic blowing with the same frequency as the unsteady aerodynamic force reduces the aerodynamic force in a manner similar to the steady blowing.

  2. Computational Investigation of Tangential Slot Blowing on a Generic Chined Forebody

    NASA Technical Reports Server (NTRS)

    Agosta-Greenman, Roxana M.; Gee, Ken; Cummings, Russell M.; Schiff, Lewis B.

    1995-01-01

    The effect of tangential slot blowing on the flowfield about a generic chined forebody at high angles of attack is investigated numerically using solutions of the thin-layer, Reynolds-averaged, Navier-Stokes equations. The effects of jet mass now ratios, angle of attack, and blowing slot location in the axial and circumferential directions are studied. The computed results compare well with available wind-tunnel experimental data. Computational results show that for a given mass now rate, the yawing moments generated by slot blowing increase as the body angle of attack increases. It is observed that greater changes in the yawing moments are produced by a slot located closest to the lip of the nose. Also, computational solutions show that inboard blowing across the top surface is more effective at generating yawing moments than blowing outboard from the bottom surface.

  3. Flow visualization studies of blowing from the tip of a swept wing

    NASA Technical Reports Server (NTRS)

    Smith, Jeannette W.; Mineck, Raymond E.; Neuhart, Dan H.

    1990-01-01

    Flow visualization studies of blowing from the tip of a swept wing were conducted in the Langley 16- by 24-inch water tunnel. Four wing tips, each with two independent blowing slots, were tested. The two slots were located one behind the other in the chordwise direction. The wing tips were designed to vary systematically the jet length, the jet in-plane exhaust direction (sweep), and the jet out-of-plane exhaust direction (anhedral). Each blowing slot was tested separately at two angles of attack and at four ratios of jet to free stream velocity ratios. Limited tests were conducted with blowing from both slots simultaneously. Blowing from the tip inhibited inboard spanwise flow on the upper wing surface near the tip. The jet path moved farther away from the tip with increasing jet to free stream velocity ratio and moved closer to the tip with increasing angle of attack.

  4. Analysis of Tangential Slot Blowing on F/A-18 Isolated Forebody

    NASA Technical Reports Server (NTRS)

    Gee, Ken; Rizk, Yehia M.; Schiff, Lewis B.

    1995-01-01

    The generation of significant side forces and yawing moments on an F/A-18 fuselage through tangential slot blowing is analyzed using computational fluid dynamics. The effects of freestream Mach number, jet exit conditions, jet length, and jet location are studied. The effects of over- and underblowing on force and moment production are analyzed. Non-time-accurate solutions are obtained to determine the steady-state side forces, yawing moments, and surface pressure distributions generated by tangential slot blowing. Time-accurate solutions are obtained to study the force onset time lag of tangential slot blowing. Comparison with available experimental data from full-scale wind-tunnel and subscale wind-tunnel tests are made. This computational analysis complements the experimental results and provides a detailed understanding of the effects of tangential slot blowing on the flowfield about the isolated F/A-18 forebody. Additionally, it extends the slot-blowing database to transonic maneuvering Mach numbers.

  5. Tangential blowing for control of strong normal shock - Boundary layer interactions on inlet ramps

    NASA Technical Reports Server (NTRS)

    Schwendemann, M. F.; Sanders, B. W.

    1982-01-01

    The use of tangential blowing from a row of holes in an aft facing step is found to provide good control of the ramp boundary layer, normal shock interaction on a fixed geometry inlet over a wide range of inlet mass flow ratios. Ramp Mach numbers of 1.36 and 1.96 are investigated. The blowing geometry is found to have a significant effect on system performance at the highest Mach number. The use of high-temperature air in the blowing system, however, has only a slight effect on performance. The required blowing rates are significantly high for the most severe test conditions. In addition, the required blowing coefficient is found to be proportional to the normal shock pressure rise.

  6. The development of three-dimensional adjoint method for flow control with blowing in convergent-divergent nozzle flows

    NASA Astrophysics Data System (ADS)

    Sikarwar, Nidhi

    The noise produced by the low bypass ratio turbofan engines used to power fighter aircraft is a problem for communities near military bases and for personnel working in close proximity to the aircraft. For example, carrier deck personnel are subject to noise exposure that can result in Noise-Induced Hearing Loss which in-turn results in over a billion dollars of disability payments by the Veterans Administration. Several methods have been proposed to reduce the jet noise at the source. These methods include microjet injection of air or water downstream of the jet exit, chevrons, and corrugated nozzle inserts. The last method involves the insertion of corrugated seals into the diverging section of a military-style convergent-divergent jet nozzle (to replace the existing seals). This has been shown to reduce both the broadband shock-associated noise as well as the mixing noise in the peak noise radiation direction. However, the original inserts were designed to be effective for a take-off condition where the jet is over-expanded. The nozzle performance would be expected to degrade at other conditions, such as in cruise at altitude. A new method has been proposed to achieve the same effects as corrugated seals, but using fluidic inserts. This involves injection of air, at relatively low pressures and total mass flow rates, into the diverging section of the nozzle. These fluidic inserts" deflect the flow in the same way as the mechanical inserts. The fluidic inserts represent an active control method, since the injectors can be modified or turned off depending on the jet operating conditions. Noise reductions in the peak noise direction of 5 to 6 dB have been achieved and broadband shock-associated noise is effectively suppressed. There are multiple parameters to be considered in the design of the fluidic inserts. This includes the number and location of the injectors and the pressures and mass flow rates to be used. These could be optimized on an ad hoc basis with

  7. Ethmoid sinus osteoma associated with blow-out fracture.

    PubMed

    Kim, Young-Jin; Kim, Dong-Yeon; Jun, Young-Joon; Seo, Byung-Chul

    2012-03-01

    Osteoma is a benign tumor that is composed of compact or cancellous bone. It is the most common benign neoplasm of the paranasal sinus, and ethmoid sinuses are the second most common sites of paranasal sinus osteoma. The symptoms of ethmoid sinus osteoma can give rise to various kinds and extent of symptoms. In symptomatic cases, surgical management is necessary, but appropriate surgical approach to the ethmoid sinus is not clearly established. We describe 2 male patients with a diagnosis of blow-out fractures after trauma; ethmoid sinus osteoma on preoperative computed tomography scans was coincidentally found, and the surgical correction was done simultaneously. The purpose of this article was to present the successful surgical removal of ethmoid osteoma through lamina papyracea and transcaruncular approach, resulting in both successful surgical correction and good cosmetic outcome.

  8. Skin Friction Reduction by Micro-Blowing Technique

    NASA Technical Reports Server (NTRS)

    Hwang, Danny P. (Inventor)

    1998-01-01

    A system and method for reducing skin friction of an object in relative motion to a fluid. A skin forming a boundary between the object and the fluid, the skin having holes through which micro-blowing of air is blown and a transmitting mechanism for transmitting air through the skin. The skin has an inner layer and an outer layer. the inner layer being a low permeable porous sheet, the outer layer being a plate having high aspect ratio high porosity. and small holes. The system may further include a suction apparatus for suctioning air from the outer layer. The method includes the steps of transmitting air through the inner layer and passing the air transmitted through the inner layer to the outer layer. The method may further include the step of bleeding air off the outer layer using the suction apparatus.

  9. Potential application of aromatic plant extracts to prevent cheese blowing.

    PubMed

    Librán, C M; Moro, A; Zalacain, A; Molina, A; Carmona, M; Berruga, M I

    2013-07-01

    This study aimed to inhibit the growth of Escherichia coli and Clostridium tyrobutyricum, common bacteria responsible for early and late cheese blowing defects respectively, by using novel aqueous extracts obtained by dynamic solid-liquid extraction and essential oils obtained by solvent free microwave extraction from 12 aromatic plants. In terms of antibacterial activity, a total of 13 extracts inhibited one of the two bacteria, and only two essential oils, Lavandula angustifolia Mill. and Lavandula hybrida, inhibited both. Four aqueous extracts were capable of inhibiting C. tyrobutyricum, but none were effective against E. coli. After extracts' chemical composition identification, relationship between the identified compounds and their antibacterial activity were performed by partial least square regression models revealing that compounds such as 1,8 cineole, linalool, linalyl acetate, β-phellandrene or verbene (present in essential oils), pinocarvone, pinocamphone or coumaric acid derivate (in aqueous extracts) were compounds highly correlated to the antibacterial activity. PMID:23417280

  10. Reduction of Flap Side Edge Noise - the Blowing Flap

    NASA Technical Reports Server (NTRS)

    Hutcheson, Florence V.; Brooks, THomas F.

    2005-01-01

    A technique to reduce the noise radiating from a wing-flap side edge is being developed. As an airplane wing with an extended flap is exposed to a subsonic airflow, air is blown outward through thin rectangular chord-wise slots at various locations along the side edges and side surface of the flap to weaken and push away the vortices that originate in that region of the flap and are responsible for important noise emissions. Air is blown through the slots at up to twice the local flow velocity. The blowing is done using one or multiple slots, where a slot is located along the top, bottom or side surface of the flap along the side edge, or also along the intersection of the bottom (or top) and side surfaces.

  11. Potential application of aromatic plant extracts to prevent cheese blowing.

    PubMed

    Librán, C M; Moro, A; Zalacain, A; Molina, A; Carmona, M; Berruga, M I

    2013-07-01

    This study aimed to inhibit the growth of Escherichia coli and Clostridium tyrobutyricum, common bacteria responsible for early and late cheese blowing defects respectively, by using novel aqueous extracts obtained by dynamic solid-liquid extraction and essential oils obtained by solvent free microwave extraction from 12 aromatic plants. In terms of antibacterial activity, a total of 13 extracts inhibited one of the two bacteria, and only two essential oils, Lavandula angustifolia Mill. and Lavandula hybrida, inhibited both. Four aqueous extracts were capable of inhibiting C. tyrobutyricum, but none were effective against E. coli. After extracts' chemical composition identification, relationship between the identified compounds and their antibacterial activity were performed by partial least square regression models revealing that compounds such as 1,8 cineole, linalool, linalyl acetate, β-phellandrene or verbene (present in essential oils), pinocarvone, pinocamphone or coumaric acid derivate (in aqueous extracts) were compounds highly correlated to the antibacterial activity.

  12. Soot blower using fuel gas as blowing medium

    DOEpatents

    Tanca, Michael C.

    1982-01-01

    A soot blower assembly (10) for use in combination with a coal gasifier (14). The soot blower assembly is adapted for use in the hot combustible product gas generated in the gasifier as the blowing medium. The soot blower lance (20) and the drive means (30) by which it is moved into and out of the gasifier is housed in a gas tight enclosure (40) which completely surrounds the combination. The interior of the enclosure (40) is pressurized by an inert gas to a pressure level higher than that present in the gasifier so that any combustible product gas leaking from the soot blower lance (20) is forced into the gasifier rather than accumulating within the enclosure.

  13. 22. Blow Down Valve for Unit 1, view to the ...

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

    22. Blow Down Valve for Unit 1, view to the southwest. This valve allows the water in the draft chest to be lowered (i.e., 'blown down') so that the unit can be motored (i.e., run like an electric motor rather than an electric power generator). The valve is operated by pressure from the instrument air system (part of which is visible in photograph MT-105-A-17 above), but the unit draws on the station air system (see photograph MT-105-A-24 below) to lower the water in the draft chest. - Washington Water Power Clark Fork River Noxon Rapids Hydroelectric Development, Powerhouse, South bank of Clark Fork River at Noxon Rapids, Noxon, Sanders County, MT

  14. Wagon loads of sand blows in White County, Illinois

    USGS Publications Warehouse

    Hough, S.E.; Bilham, R.; Mueller, K.; Stephenson, W.; Williams, R.; Odum, J.

    2005-01-01

    Several anecdotal accounts provide compelling evidence that liquefaction occurred at several sites in Illinois during the 1811-1812 New Madrid sequence, as much as 250 km north of the New Madrid seismic zone (NMSZ). At one Wabash Valley location, sand blows are still evident near Big Prairie, Illinois, a location described in a particularly detailed and precise historic account. This account includes descriptions of substantial liquefaction (sand blows) as well as a two-mile-long east-west-trending "crack" along which two feet of south-side-down displacement occurred. An offset can no longer be seen at this location, which has been extensively farmed and plowed for decades. Field reconnaissance verifies many of the details provided in the account, however. We conducted a seismic-reflection experiment at this location and observed a modest offset in the Paleozoic strata at this location. The offset is opposite to that described in the historic account, consistent with the hypothesis that large midcontinent earthquakes occur on faults reactivated in a Holocene stress regime different from the one in which they were formed. Only two explanations can account for these observations: Either large NMSZ events triggered substantial liquefaction at distances greater than hitherto realized, or at least one large "New Madrid" event occurred significantly north of the NMSZ. We explore these possibilities and conclude that, while neither one can be ruled out, several disparate lines of evidence suggest that the 23 January 1812 "New Madrid mainshock" occurred in White County, Illinois, near the location of the mb 5.5 1968 southern Illinois earthquake and recent microearthquake activity.

  15. Influence of particles shape on the vertical profile of blowing snow concentration

    NASA Astrophysics Data System (ADS)

    Vionnet, Vincent; Trouvilliez, Alexandre; Naaim-Bouvet, Florence; Guyomarc'h, Gilbert

    2013-04-01

    In alpine regions, blowing snow events strongly influence the temporal and spatial evolution of the snow cover throughout the winter season. In Antarctica, blowing snow is an essential surface mass balance process and plays a non-negligible role in the annual accumulation. The vertical profile of blowing snow concentration determines the quantity of snow transported in turbulent suspension. A power law is often used to represent this vertical profile. It serves as an analytical solution representing an equilibrium between vertical turbulent diffusion and gravitational settling. In this work, we study how the exponent of the power law depends on the type of transported particles. Vertical profiles of blowing snow concentration have been collected at the experimental site of Col du Lac Blanc (French Alps) in 2011 and 2012 and near the research station of Cap Prud'homme (Antarctica) in 2010 and 2011. We used mechanical gauges (butterfly nets) and optical devices (Snow Particles Counters). Profiles collected during blowing snow events with precipitation have been corrected to account for the contribution of snowfall. Results show that profiles collected during blowing snow without snowfall differ from the corrected profiles collected during snowfall. At a given wind speed, particles transported during snowfall have a lower settling velocity than particles transported without snowfall. This difference confirms earlier observations (Takahashi, 1985) and can be explained by the change of drag coefficient between dendritic and rounded particles. This difference pertains several hours after the end of the snowfall illustrating the fragmentation of snow grains during blowing snow events.

  16. Roll-Yaw control at high angle of attack by forebody tangential blowing

    NASA Technical Reports Server (NTRS)

    Pedreiro, N.; Rock, S. M.; Celik, Z. Z.; Roberts, L.

    1995-01-01

    The feasibility of using forebody tangential blowing to control the roll-yaw motion of a wind tunnel model is experimentally demonstrated. An unsteady model of the aerodynamics is developed based on the fundamental physics of the flow. Data from dynamic experiments is used to validate the aerodynamic model. A unique apparatus is designed and built that allows the wind tunnel model two degrees of freedom, roll and yaw. Dynamic experiments conducted at 45 degrees angle of attack reveal the system to be unstable. The natural motion is divergent. The aerodynamic model is incorporated into the equations of motion of the system and used for the design of closed loop control laws that make the system stable. These laws are proven through dynamic experiments in the wind tunnel using blowing as the only actuator. It is shown that asymmetric blowing is a highly non-linear effector that can be linearized by superimposing symmetric blowing. The effects of forebody tangential blowing and roll and yaw angles on the flow structure are determined through flow visualization experiments. The transient response of roll and yaw moments to a step input blowing are determined. Differences on the roll and yaw moment dependence on blowing are explained based on the physics of the phenomena.

  17. Foam injection molding of thermoplastic elastomers: Blowing agents, foaming process and characterization of structural foams

    NASA Astrophysics Data System (ADS)

    Ries, S.; Spoerrer, A.; Altstaedt, V.

    2014-05-01

    Polymer foams play an important role caused by the steadily increasing demand to light weight design. In case of soft polymers, like thermoplastic elastomers (TPE), the haptic feeling of the surface is affected by the inner foam structure. Foam injection molding of TPEs leads to so called structural foam, consisting of two compact skin layers and a cellular core. The properties of soft structural foams like soft-touch, elastic and plastic behavior are affected by the resulting foam structure, e.g. thickness of the compact skins and the foam core or density. This inner structure can considerably be influenced by different processing parameters and the chosen blowing agent. This paper is focused on the selection and characterization of suitable blowing agents for foam injection molding of a TPE-blend. The aim was a high density reduction and a decent inner structure. Therefore DSC and TGA measurements were performed on different blowing agents to find out which one is appropriate for the used TPE. Moreover a new analyzing method for the description of processing characteristics by temperature dependent expansion measurements was developed. After choosing suitable blowing agents structural foams were molded with different types of blowing agents and combinations and with the breathing mold technology in order to get lower densities. The foam structure was analyzed to show the influence of the different blowing agents and combinations. Finally compression tests were performed to estimate the influence of the used blowing agent and the density reduction on the compression modulus.

  18. Suppression of Dynamic Stall by Steady and Pulsed Upper-Surface Blowing

    NASA Technical Reports Server (NTRS)

    Weaver, D.; McAlister, K. W.; Tso, J.

    1996-01-01

    The Boeing-Vertol VR-7 airfoil was experimentally studied with steady and pulsed upper-surface blowing for sinusoidal pitching oscillations described by alpha = alpha(sub m) + 10 deg sin(omega t). The tests were conducted in the U.S. Army Aeroflightdynamics Directorate's Water Tunnel at NASA Ames Research Center. The experiment was performed at a Reynolds number of 100,000. Pitch oscillations with alpha(sub m) = 10 deg and 15 deg and with reduced frequencies ranging from k = 0.005 to 0.15 were examined. Blowing conditions ranged from C(sub mu) = 0.03 to 0.66 and F(+) = 0 to 3. Unsteady lift, drag, and pitching-moment loads were measured, and fluorescent-dye flow visualizations were obtained. Steady, upper-surface blowing was found to be capable of trapping a separation bubble near the leading edge during a portion of the airfoil's upward rotation. When this occurred, the lift was increased significantly and stall was averted. In all cases, steady blowing reduced the hysteresis amplitudes present in the loads and produced a large thrust force. The benefits of steady blowing diminished as the reduced frequency and mean angle of oscillation increased. Pulsed blowing showed only marginal benefits for the conditions tested. The greatest gains from pulsed blowing were achieved at F(+) = 0.9.

  19. Effect of blowing agents on the oxidation resistance of carbon foams prepared from molten sucrose

    NASA Astrophysics Data System (ADS)

    Narasimman, R.; Prabhakaran, K.

    2013-06-01

    We have prepared low density carbon foams from molten sucrose using aluminium nitrate and boric acid blowing agents. A comparative study of the oxidation resistance of the carbon foams prepared using the two blowing agents are reported in the present paper. Oxidation of the carbon foams was evaluated under isothermal and non-isothermal conditions in air atmosphere using thermogravimetric analysis (TGA). We have observed that the alumina produced from the aluminium nitrate blowing agent acts as a catalyst whereas the boron produced from boric acid inhibits the oxidation of the carbon foams. The oxidation resistance of carbon foams increases with boron concentration. The oxidation onset temperature for the carbon foams prepared using boric acid blowing agent was nearly 60°C higher than that prepared using aluminium nitrate blowing agent. Carbon foams prepared using aluminium nitrate blowing agent undergoes complete oxidation at temperature less than 700°C. Whereas that prepared using boric acid blowing agent leave ˜ 50 wt.% residue at 900°C. Further evidence is provided by the kinetic analysis of the TGA using Coats-Redfern (CR) equation.

  20. Numerical study of the trailing vortex of a wing with wing-tip blowing

    NASA Technical Reports Server (NTRS)

    Lim, Hock-Bin

    1994-01-01

    Trailing vortices generated by lifting surfaces such as helicopter rotor blades, ship propellers, fixed wings, and canard control surfaces are known to be the source of noise, vibration, cavitation, degradation of performance, and other hazardous problems. Controlling these vortices is, therefore, of practical interest. The formation and behavior of the trailing vortices are studied in the present research. In addition, wing-tip blowing concepts employing axial blowing and spanwise blowing are studied to determine their effectiveness in controlling these vortices and their effects on the performance of the wing. The 3D, unsteady, thin-layer compressible Navier-Stokes equations are solved using a time-accurate, implicit, finite difference scheme that employs LU-ADI factorization. The wing-tip blowing is simulated using the actuator plane concept, thereby, not requiring resolution of the jet slot geometry. Furthermore, the solution blanking feature of the chimera scheme is used to simplify the parametric study procedure for the wing-tip blowing. Computed results are shown to compare favorably with experimental measurements. It is found that axial wing-tip blowing, although delaying the rolling-up of the trailing vortices and the near-field behavior of the flowfield, does not dissipate the circulation strength of the trailing vortex farther downstream. Spanwise wing-tip blowing has the effect of displacing the trailing vortices outboard and upward. The increased 'wing-span' due to the spanwise wing-tip blowing has the effect of lift augmentation on the wing and the strengthening of the trailing vortices. Secondary trailing vortices are created at high spanwise wing-tip blowing intensities.

  1. Free-flight investigation of forebody blowing for stability and control

    NASA Technical Reports Server (NTRS)

    Brandon, Jay M.; Simon, James M.; Owens, D. Bruce; Kiddy, Jason S.

    1996-01-01

    A free-flight wind-tunnel investigation was conducted on a generic fighter model with forebody pneumatic vortex control for high angle-of-attack directional control. This is believed to be the first flight demonstration of a forebody blowing concept integrated into a closed-loop flight control system for stability augmentation and control. The investigation showed that the static wind tunnel estimates of the yaw control available generally agreed with flight results. The control scheme for the blowing nozzles consisted of an on/off control with a deadband. Controlled flight was obtained for the model using forebody blowing for directional control to beyond 45 deg. angle of attack.

  2. An experimental investigation of leading-edge vortex augmentation by blowing

    NASA Technical Reports Server (NTRS)

    Bradley, R. G.; Wray, W. O.; Smith, C. W.

    1974-01-01

    A wind tunnel test was conducted to determine the effects of over-the-wing blowing as a means of augmenting the leading-edge vortex flow of several pointed-tip, sharp-edged planforms. Arrow, delta, and diamond wings with leading-edge sweeps of 30 and 45 degrees were mounted on a body-of-revolution fuselage and tested in a low-speed wind tunnel at a Mach number of 0.2. Nozzle location data, pitch data, and flow-visualization pictures were obtained for a range of blowing rates. Results show pronounced increases in vortex lift due to the blowing.

  3. Stable Self-Similar Blow-Up Dynamics for Slightly {L^2}-Supercritical Generalized KDV Equations

    NASA Astrophysics Data System (ADS)

    Lan, Yang

    2016-07-01

    In this paper we consider the slightly {L^2}-supercritical gKdV equations {partial_t u+(u_{xx}+u|u|^{p-1})_x=0}, with the nonlinearity {5 < p < 5+\\varepsilon} and {0 < \\varepsilon≪ 1}. We will prove the existence and stability of a blow-up dynamics with self-similar blow-up rate in the energy space {H^1} and give a specific description of the formation of the singularity near the blow-up time.

  4. On the blow-up solutions for the nonlinear fractional Schrödinger equation

    NASA Astrophysics Data System (ADS)

    Zhu, Shihui

    2016-07-01

    This paper is dedicated to the blow-up solutions for the nonlinear fractional Schrödinger equation arising from pseudorelativistic Boson stars. First, we compute the best constant of a gG-N inequality by the profile decomposition theory and variational arguments. Then, we find the sharp threshold mass of the existence of finite-time blow-up solutions. Finally, we study the dynamical properties of finite-time blow-up solutions around the sharp threshold mass by giving a refined compactness lemma.

  5. Oxygen and carbon discovered in exoplanet atmosphere `blow-off'

    NASA Astrophysics Data System (ADS)

    2004-02-01

    Oxygen and carbon discovered in exoplanet atmosphere ‘blow-off’ hi-res Size hi-res: 1096 kb Credits: ESA/Alfred Vidal-Madjar (Institut d’Astrophysique de Paris, CNRS, France) Oxygen and carbon discovered in exoplanet atmosphere ‘blow-off’ This artist’s impression shows an extended ellipsoidal envelope - the shape of a rugby-ball - of oxygen and carbon discovered around the well-known extrasolar planet HD 209458b. An international team of astronomers led by Alfred Vidal-Madjar (Institut d’Astrophysique de Paris, CNRS, France) observed the first signs of oxygen and carbon in the atmosphere of a planet beyond our Solar System for the first time using the NASA/ESA Hubble Space Telescope. The atoms of carbon and oxygen are swept up from the lower atmosphere with the flow of escaping atmospheric atomic hydrogen - like dust in a supersonic whirlwind - in a process called atmospheric ‘blow off’. Oxygen and carbon have been detected in the atmosphere of a planet beyond our Solar System for the first time. Scientists using the NASA/ESA Hubble Space Telescope have observed the famous extrasolar planet HD 209458b passing in front of its parent star, and found oxygen and carbon surrounding the planet in an extended ellipsoidal envelope - the shape of a rugby-ball. These atoms are swept up from the lower atmosphere with the flow of the escaping atmospheric atomic hydrogen, like dust in a supersonic whirlwind. The team led by Alfred Vidal-Madjar (Institut d’Astrophysique de Paris, CNRS, France) reports this discovery in a forthcoming issue of Astrophysical Journal Letters. The planet, called HD 209458b, may sound familiar. It is already an extrasolar planet with an astounding list of firsts: the first extrasolar planet discovered transiting its sun, the first with an atmosphere, the first observed to have an evaporating hydrogen atmosphere (in 2003 by the same team of scientists) and now the first to have an atmosphere containing oxygen and carbon. Furthermore

  6. Glass Blowing -- Try It, You'll Like It.

    ERIC Educational Resources Information Center

    Dilavore, Philip

    1982-01-01

    Discusses the basics of scientific glassblowing, including equipment needed, lighting a hand torch (which uses a gas and oxygen mixture), and cutting tubing. Also discusses preparation of butt joints, tee joints, and bends. Photographs illustrating various techniques are provided. (JN)

  7. Towards improving efficiency of control for blowing into a boundary layer through a permeable wall

    NASA Astrophysics Data System (ADS)

    Fomin, V. M.; Kornilov, V. I.; Boiko, A. V.

    2016-08-01

    The results of experimental and numerical investigations of the efficiency of control by an incompressible turbulent boundary layer with the help air blowing through a permeable wall fabricated with maintenance of most of the necessary requirements for the quality and configuration of microapertures and having a low effective roughness are analyzed. Various cases of modeling the process of air blowing into the boundary layer through a specified hi-tech finely perforated surface are considered, and the data for average parameters and characteristics of turbulence of the flow types under investigation are presented. A substantial decrease in the skin-friction coefficient along the model length, which can achieve 90% with increasing the blowing coefficient, is shown. The estimate of the energy consumption for the process of blowing under terrestrial conditions testifies to the high potential of this method of control capable to provide 4-5% gain in the total aerodynamic drag of a simple modeling configuration.

  8. Blow-up of the solution of a nonlinear system of equations with positive energy

    NASA Astrophysics Data System (ADS)

    Korpusov, M. O.

    2012-06-01

    We consider the Dirichlet problem for a nonlinear system of equations, continuing our study of nonlinear hyperbolic equations and systems of equations with an arbitrarily large positive energy. We use a modified Levine method to prove the blow-up.

  9. Numerical and experimental study of blowing jet on a high lift airfoil

    NASA Astrophysics Data System (ADS)

    Bobonea, A.; Pricop, M. V.

    2013-10-01

    Active manipulation of separated flows over airfoils at moderate and high angles of attack in order to improve efficiency or performance has been the focus of a number of numerical and experimental investigations for many years. One of the main methods used in active flow control is the usage of blowing devices with constant and pulsed blowing. Through CFD simulation over a 2D high-lift airfoil, this study is trying to highlight the impact of pulsed blowing over its aerodynamic characteristics. The available wind tunnel data from INCAS low speed facility are also beneficial for the validation of the numerical analysis. This study intends to analyze the impact of the blowing jet velocity and slot geometry on the efficiency of an active flow control.

  10. Blow-up in p-Laplacian heat equations with nonlinear boundary conditions

    NASA Astrophysics Data System (ADS)

    Ding, Juntang; Shen, Xuhui

    2016-10-01

    In this paper, we investigate the blow-up of solutions to the following p-Laplacian heat equations with nonlinear boundary conditions: {l@{quad}l}(h(u))_t =nabla\\cdot(|nabla u|pnabla u)+k(t)f(u) &{in } Ω×(0,t^{*}), |nabla u|ppartial u/partial n=g(u) &on partialΩ×(0,t^{*}), u(x,0)=u0(x) ≥ 0 & {in } overline{Ω},. where {p ≥ 0} and {Ω} is a bounded convex domain in {RN}, {N ≥ 2} with smooth boundary {partialΩ}. By constructing suitable auxiliary functions and using a first-order differential inequality technique, we establish the conditions on the nonlinearities and data to ensure that the solution u( x, t) blows up at some finite time. Moreover, the upper and lower bounds for the blow-up time, when blow-up does occur, are obtained.

  11. First Satellite-detected Perturbations of Outgoing Longwave Radiation Associated with Blowing Snow Events over Antarctica

    NASA Technical Reports Server (NTRS)

    Yang, Yuekui; Palm, Stephen P.; Marshak, Alexander; Wu, Dong L.; Yu, Hongbin; Fu, Qiang

    2014-01-01

    We present the first satellite-detected perturbations of the outgoing longwave radiation (OLR) associated with blowing snow events over the Antarctic ice sheet using data from Cloud-Aerosol Lidar with Orthogonal Polarization and Clouds and the Earth's Radiant Energy System. Significant cloud-free OLR differences are observed between the clear and blowing snow sky, with the sign andmagnitude depending on season and time of the day. During nighttime, OLRs are usually larger when blowing snow is present; the average difference in OLRs between without and with blowing snow over the East Antarctic Ice Sheet is about 5.2 W/m2 for the winter months of 2009. During daytime, in contrast, the OLR perturbation is usually smaller or even has the opposite sign. The observed seasonal variations and day-night differences in the OLR perturbation are consistent with theoretical calculations of the influence of blowing snow on OLR. Detailed atmospheric profiles are needed to quantify the radiative effect of blowing snow from the satellite observations.

  12. Fledging success is a poor indicator of the effects of bird blow flies on ovenbird survival

    USGS Publications Warehouse

    Peterson, Sean M.; Streby, Henry M.; Kapfer, Paul M.

    2009-01-01

    Infestations of bird blow flies (Protocalliphora spp. and Trypocalliphora braueri) have various negative effects on the condition of nestling birds. In the absence of other stressors such as inclement weather, however, infestation alone rarely reduces fledging success. Previous studies have documented effects of blow flies on nestling condition and fledging success. Without information regarding fledgling survival, the full effect of blow-fly infestation remains unclear. To fully investigate the effect of blow-fly infestation on reproductive success of the Ovenbird (Seiurus aurocapilla), we monitored infested and non-infested nests and monitored fledglings from each by using radio telemetry. Blow flies did not affect birds during the nestling period, as brood size, mean nestling mass, fledging success, and time to fledging in infested and non-infested nests were no different. Fledgling survival and minimum distance traveled the first day after fledging, however, were significantly lower for infected fledglings than for those that were not infected. We conclude that the stress of the early fledgling period combined with recent or concurrent blow-fly infection increases mortality in young Oven-birds. Our results demonstrate the importance of including the post-fledging period in investigations of the effects of ectoparasitic infestations on birds.

  13. Control of Flow Structure on Low Swept Delta Wing with Steady Leading Edge Blowing

    NASA Astrophysics Data System (ADS)

    Ozturk, Ilhan; Zharfa, Mohammadreza; Yavuz, Mehmet Metin

    2014-11-01

    Interest in unmanned combat air vehicles (UCAVs) and micro air vehicles (MAVs) has stimulated investigation of the flow structure, as well as its control, on delta wings having low and moderate values of sweep angle. In the present study, the flow structure is characterized on a delta wing of low sweep 35-degree angle, which is subjected to steady leading edge blowing. The techniques of laser illuminated smoke visualization, laser Doppler anemometry (LDA), and surface pressure measurements are employed to investigate the steady and unsteady nature of the flow structure on delta wing, in relation to the dimensionless magnitude of the blowing coefficient. Using statistics and spectral analysis, unsteadiness of the flow structure is studied in detail. Different injection locations are utilized to apply different blowing patterns in order to identify the most efficient control, which provides the upmost change in the flow structure with the minimum energy input. The study aims to find the optimum flow control strategy to delay or to prevent the stall and possibly to reduce the buffeting on the wing surface. Since the blowing set-up is computer controlled, the unsteady blowing patterns compared to the present steady blowing patterns will be studied next. This project was supported by the Scientific and Technological Research Council of Turkey (Project Number: 3501 111M732).

  14. Lean Blow-out Studies in a Swirl Stabilized Annular Gas Turbine Combustor

    NASA Astrophysics Data System (ADS)

    Mishra, R. K.; Kishore Kumar, S.; Chandel, Sunil

    2015-05-01

    Lean blow out characteristics in a swirl stabilized aero gas turbine combustor have been studied using computational fluid dynamics. For CFD analysis, a 22.5° sector of an annular combustor is modeled using unstructured tetrahedral meshes comprising 1.2 × 106 elements. The governing equations are solved using the eddy dissipation combustion model in CFX. The primary combustion zone is analyzed by considering it as a well stirred reactor. The analysis has been carried out for different operating conditions of the reactants entering into the control volume. The results are treated as the base-line or reference values. Combustion lean blow-out limits are further characterized studying the behavior of combustion zone during transient engine operation. The validity of the computational study has been established by experimental study on a full-scale annular combustor in an air flow test facility that is capable of simulating different conditions at combustor inlet. The experimental result is in a good agreement with the analytical predictions. Upon increasing the combustor mass flow, the lean blow out limit increases, i.e., the blow out occurs at higher fuel-air ratios. In addition, when the operating pressure decreases, the lean blow out limit increases, i.e., blow out occurs at higher fuel-air ratios.

  15. Flutter Stability Verified for the Trailing Edge Blowing Fan

    NASA Technical Reports Server (NTRS)

    Bakhle, Milind A.; Srivastava, Rakesh

    2005-01-01

    The TURBO-AE aeroelastic code has been used to verify the flutter stability of the trailing edge blowing (TEB) fan, which is a unique technology demonstrator being designed and fabricated at the NASA Glenn Research Center for testing in Glenn s 9- by 15-Foot Low-Speed Wind Tunnel. Air can be blown out of slots near the trailing edges of the TEB fan blades to fill in the wakes downstream of the rotating blades, which reduces the rotor-stator interaction (tone) noise caused by the interaction of wakes with the downstream stators. The TEB fan will demonstrate a 1.6-EPNdB reduction in tone noise through wake filling. Furthermore, the reduced blade-row interaction will decrease the possibility of forced-response vibrations and enable closer spacing of blade rows, thus reducing engine length and weight. The detailed aeroelastic analysis capability of the three-dimensional Navier-Stokes TURBO-AE code was used to check the TEB fan rotor blades for flutter stability. Flutter calculations were first performed with no TEB flow; then select calculations were repeated with TEB flow turned on.

  16. High speed aerodynamics of upper surface blowing aircraft configurations

    NASA Technical Reports Server (NTRS)

    Birckelbaw, Larry D.

    1992-01-01

    An experimental investigation of the high speed aerodynamics of Upper Surface Blowing (USB) aircraft configurations has been conducted to accurately define the magnitude and causes of the powered configuration cruise drag. A highly instrumented wind tunnel model of a realistic USB configuration was used which permitted parametric variations in the number and spanwise location of the nacelles and was powered with two turbofan engine simulators. The tests conducted in the Ames 14 Foot Transonic Wind Tunnel examined 10 different configurations at Mach numbers from 0.5 to 0.775, fan nozzle pressure ratios from 1.1 to 2.1 and angles of attack from -4 to 6 degrees. Measured force data is presented which indicates the cruise drag penalty associated with each configuration and surface pressure contour plots are used to illustrate the underlying flowfield physics. It was found that all of the tested configurations suffered from a severe drag penalty which increased with freestream Mach number, power setting and angle of attack and was associated with the presence of strong shocks and regions of separated flow in the wing/nacelle junction regions.

  17. Generating Soap Bubbles by Blowing on Soap Films

    NASA Astrophysics Data System (ADS)

    Salkin, Louis; Schmit, Alexandre; Panizza, Pascal; Courbin, Laurent

    2016-02-01

    Making soap bubbles by blowing air on a soap film is an enjoyable activity, yet a poorly understood phenomenon. Working either with circular bubble wands or long-lived vertical soap films having an adjustable steady state thickness, we investigate the formation of such bubbles when a gas is blown through a nozzle onto a film. We vary film size, nozzle radius, space between the film and nozzle, and gas density, and we measure the gas velocity threshold above which bubbles are formed. The response is sensitive to containment, i.e., the ratio between film and jet sizes, and dissipation in the turbulent gas jet, which is a function of the distance from the film to the nozzle. We rationalize the observed four different regimes by comparing the dynamic pressure exerted by the jet on the film and the Laplace pressure needed to create the curved surface of a bubble. This simple model allows us to account for the interplay between hydrodynamic, physicochemical, and geometrical factors.

  18. Generating Soap Bubbles by Blowing on Soap Films.

    PubMed

    Salkin, Louis; Schmit, Alexandre; Panizza, Pascal; Courbin, Laurent

    2016-02-19

    Making soap bubbles by blowing air on a soap film is an enjoyable activity, yet a poorly understood phenomenon. Working either with circular bubble wands or long-lived vertical soap films having an adjustable steady state thickness, we investigate the formation of such bubbles when a gas is blown through a nozzle onto a film. We vary film size, nozzle radius, space between the film and nozzle, and gas density, and we measure the gas velocity threshold above which bubbles are formed. The response is sensitive to containment, i.e., the ratio between film and jet sizes, and dissipation in the turbulent gas jet, which is a function of the distance from the film to the nozzle. We rationalize the observed four different regimes by comparing the dynamic pressure exerted by the jet on the film and the Laplace pressure needed to create the curved surface of a bubble. This simple model allows us to account for the interplay between hydrodynamic, physicochemical, and geometrical factors.

  19. Generating Soap Bubbles by Blowing on Soap Films.

    PubMed

    Salkin, Louis; Schmit, Alexandre; Panizza, Pascal; Courbin, Laurent

    2016-02-19

    Making soap bubbles by blowing air on a soap film is an enjoyable activity, yet a poorly understood phenomenon. Working either with circular bubble wands or long-lived vertical soap films having an adjustable steady state thickness, we investigate the formation of such bubbles when a gas is blown through a nozzle onto a film. We vary film size, nozzle radius, space between the film and nozzle, and gas density, and we measure the gas velocity threshold above which bubbles are formed. The response is sensitive to containment, i.e., the ratio between film and jet sizes, and dissipation in the turbulent gas jet, which is a function of the distance from the film to the nozzle. We rationalize the observed four different regimes by comparing the dynamic pressure exerted by the jet on the film and the Laplace pressure needed to create the curved surface of a bubble. This simple model allows us to account for the interplay between hydrodynamic, physicochemical, and geometrical factors. PMID:26943558

  20. Landauer's blow-torch effect in systems with entropic potential.

    PubMed

    Das, Moupriya; Ray, Deb Shankar

    2015-11-01

    We consider local heating of a part of a two-dimensional bilobal enclosure of a varying cross section confining a system of overdamped Brownian particles. Since varying cross section in higher dimension results in an entropic potential in lower dimension, local heating alters the relative stability of the entropic states. We show that this blow-torch effect modifies the entropic potential in a significant way so that the resultant effective entropic potential carries both the features of variation of width of the confinement and variation of temperature along the direction of transport. The reduced probability distribution along the direction of transport calculated by full numerical simulations in two dimensions agrees well with our analytical findings. The extent of population transfer in the steady state quantified in terms of the integrated probability of residence of the particles in either of the two lobes exhibits interesting variation with the mean position of the heated region. Our study reveals that heating around two particular zones of a given lobe maximizes population transfer to the other. PMID:26651672

  1. Landauer's blow-torch effect in systems with entropic potential

    NASA Astrophysics Data System (ADS)

    Das, Moupriya; Ray, Deb Shankar

    2015-11-01

    We consider local heating of a part of a two-dimensional bilobal enclosure of a varying cross section confining a system of overdamped Brownian particles. Since varying cross section in higher dimension results in an entropic potential in lower dimension, local heating alters the relative stability of the entropic states. We show that this blow-torch effect modifies the entropic potential in a significant way so that the resultant effective entropic potential carries both the features of variation of width of the confinement and variation of temperature along the direction of transport. The reduced probability distribution along the direction of transport calculated by full numerical simulations in two dimensions agrees well with our analytical findings. The extent of population transfer in the steady state quantified in terms of the integrated probability of residence of the particles in either of the two lobes exhibits interesting variation with the mean position of the heated region. Our study reveals that heating around two particular zones of a given lobe maximizes population transfer to the other.

  2. Study on the conditions necessary for blowing snow to occur in which multiple meteorological elements are considered

    NASA Astrophysics Data System (ADS)

    Omiya, S.; Takechi, H.; Kokubu, T.; Harada, Y.; Matsuzawa, M.

    2015-12-01

    Elucidation of the conditions under which blowing snow occurs is important not only in mitigating snowstorm-related disasters but also in discussing the mass balance of water. The major factor for the occurrence of blowing snow is strong winds. However, the conditions that cause blowing snow are complicated, because temperature, the condition of the snow surface, and the presence or absence of falling snow affect blowing snow occurrence. We created a formula for determining the conditions under which blowing snow will occur, based on multiple meteorological elements. In this presentation, we report the results of analysis on the occurrence conditions of blowing snow without concurrent falling snow. The observation data used in the analysis were obtained in Hokkaido, northern Japan, from December 2012 to April 2013. The observed items were air temperature, wind velocity, intensity of solar radiation, snow depth and the mass flux of blowing snow particles. In addition to the above, videos were taken to determine the presence of blowing snow. After the blowing snow events were extracted, each meteorological element was compared with the frequency of blowing snow occurrence. The analysis found that the frequency tended to be low when 12 or more hours had passed after a snowfall event or when the maximum air temperature exceeded 2 °C. It is thought that the snow particles sinter together and the surface of the snow pack hardens, and that such sintering makes it difficult for the particles fly off from the snow surface. It was shown that the frequency of blowing snow occurrence is high when large amounts of fresh snow are on the ground. Based on the above examinations, a formula for determining the occurrence of blowing snow was created using the discriminate analysis method. An accuracy verification test found the formula to have a hit ratio of 92.3%. The verification test showed the formula to be useful in determining the occurrence of blowing snow.

  3. Two persistent organic pollutants which act through different xenosensors (alpha-endosulfan and 2,3,7,8 tetrachlorodibenzo-p-dioxin) interact in a mixture and downregulate multiple genes involved in human hepatocyte lipid and glucose metabolism.

    PubMed

    Ambolet-Camoit, Ariane; Ottolenghi, Chris; Leblanc, Alix; Kim, Min Ji; Letourneur, Franck; Jacques, Sébastien; Cagnard, Nicolas; Guguen-Guillouzo, Christiane; Barouki, Robert; Aggerbeck, Martine

    2015-09-01

    Individuals, typically, are exposed to mixtures of environmental xenobiotics affecting multiple organs and acting through different xenosensors and pathways in species and cell-type specific manners. 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and α-endosulfan are Persistent Organic Pollutants (POPs) and endocrine disruptors which act through different xenosensors and accumulate in the liver. Our objective in this HEALS study was to investigate the effects of the mixture of these POPs on gene expression in a human-derived hepatocyte cell line, HepaRG. We found that, in spite of having largely uncorrelated effects, TCDD and α-endosulfan, when mixed, alter the expression of genes. The combined effects of the mixture of the POPs significantly altered the expression of 100 genes (42 up- and 58 down-regulated) whereas the same concentration of either POP alone did not alter significantly the expression of these genes. For 32 other genes, selective inhibitory crosstalk between TCDD and α-endosulfan was observed. One of the POPs inhibited the effect, on gene expression, of the other in the mixture although, when used alone, that POP did not affect expression. The expression of another 82 genes was significantly altered (up- or down-regulated) by a single POP. The addition of the second POP either increased, in the same direction, the effect on gene expression or had no further effect. At low concentrations (0.2 nM TCDD and 1 μM α-endosulfan), the POPs still had significant effects and the levels of expression of the corresponding proteins were found to be affected for some genes. Particularly striking was the 80-90% inhibition, by the mixture, of the expression of a number of genes of several hepatic intermediary metabolic pathways (glycerolipid metabolism, FXR/RXR activation, glycolysis/gluconeogenesis, retinoid and bile acid biosynthesis), whereas each pollutant alone had only a moderate effect.

  4. Process Dissociation and Mixture Signal Detection Theory

    ERIC Educational Resources Information Center

    DeCarlo, Lawrence T.

    2008-01-01

    The process dissociation procedure was developed in an attempt to separate different processes involved in memory tasks. The procedure naturally lends itself to a formulation within a class of mixture signal detection models. The dual process model is shown to be a special case. The mixture signal detection model is applied to data from a widely…

  5. Deciding which chemical mixtures risk assessment methods work best for what mixtures

    SciTech Connect

    Teuschler, Linda K.

    2007-09-01

    The most commonly used chemical mixtures risk assessment methods involve simple notions of additivity and toxicological similarity. Newer methods are emerging in response to the complexities of chemical mixture exposures and effects. Factors based on both science and policy drive decisions regarding whether to conduct a chemical mixtures risk assessment and, if so, which methods to employ. Scientific considerations are based on positive evidence of joint toxic action, elevated human exposure conditions or the potential for significant impacts on human health. Policy issues include legislative drivers that may mandate action even though adequate toxicity data on a specific mixture may not be available and risk assessment goals that impact the choice of risk assessment method to obtain the amount of health protection desired. This paper discusses three important concepts used to choose among available approaches for conducting a chemical mixtures risk assessment: (1) additive joint toxic action of mixture components; (2) toxicological interactions of mixture components; and (3) chemical composition of complex mixtures. It is proposed that scientific support for basic assumptions used in chemical mixtures risk assessment should be developed by expert panels, risk assessment methods experts, and laboratory toxicologists. This is imperative to further develop and refine quantitative methods and provide guidance on their appropriate applications. Risk assessors need scientific support for chemical mixtures risk assessment methods in the form of toxicological data on joint toxic action for high priority mixtures, statistical methods for analyzing dose-response for mixtures, and toxicological and statistical criteria for determining sufficient similarity of complex mixtures.

  6. A case study of blowing snow cooling effects on anticyclogenesis and cyclolysis

    NASA Astrophysics Data System (ADS)

    Yang, Jing; Yau, M. K.

    2011-06-01

    This paper focuses on blowing snow and its effect, through thermodynamic forcing, on anticyclogenesis and cyclolysis. A triple-moment blowing snow model (PIEKTUK-T) is coupled to an atmospheric model (MC2), and this system is used to simulate an anticyclogenesis event. For comparison, an uncoupled version of MC2 is used to model the same event. The coupled model (CPL) showed colder low-level temperatures in regions where blowing snow occurred. This cooling contributes to a rise in sea level pressure relative to the uncoupled simulation. A potential vorticity (PV) diagnostic is then applied to quantify how this microphysical cooling affects the geopotential height and balanced wind fields. Surface potential temperature differences between the coupled and uncoupled runs were used as lower boundary conditions for the inversion. The results showed that blowing snow has only a small cooling effect over the anticyclogenesis region in CPL and moderate cooling over Baffin Island, where a decaying cyclone was moving northward. The cooling induces positive geopotential height and anticyclonic flow perturbations extending up to 500 mbar over the cyclone region. The averaged inverted geopotential height anomaly at 1000 mbar level over the cooling region is up to 4.6 dam in 72 h. Surface cooling is demonstrated to play a role in the cyclolysis. The CPL run allows the relative humidity with respect to ice in the blowing snow module to remain supersaturated and includes the heat release from the supersaturated water vapor deposition. Another experiment was carried out, in which supersaturated vapor was not allowed in the blowing snow module. The sensitivity experiment results indicated that blowing snow cooling effects over Baffin Island will be much reduced.

  7. Blow collection as a non-invasive method for measuring cortisol in the beluga (Delphinapterus leucas).

    PubMed

    Thompson, Laura A; Spoon, Tracey R; Goertz, Caroline E C; Hobbs, Roderick C; Romano, Tracy A

    2014-01-01

    Non-invasive sampling techniques are increasingly being used to monitor glucocorticoids, such as cortisol, as indicators of stressor load and fitness in zoo and wildlife conservation, research and medicine. For cetaceans, exhaled breath condensate (blow) provides a unique sampling matrix for such purposes. The purpose of this work was to develop an appropriate collection methodology and validate the use of a commercially available EIA for measuring cortisol in blow samples collected from belugas (Delphinapterus leucas). Nitex membrane stretched over a petri dish provided the optimal method for collecting blow. A commercially available cortisol EIA for measuring human cortisol (detection limit 35 pg ml-1) was adapted and validated for beluga cortisol using tests of parallelism, accuracy and recovery. Blow samples were collected from aquarium belugas during monthly health checks and during out of water examination, as well as from wild belugas. Two aquarium belugas showed increased blow cortisol between baseline samples and 30 minutes out of water (Baseline, 0.21 and 0.04 µg dl-1; 30 minutes, 0.95 and 0.14 µg dl-1). Six wild belugas also showed increases in blow cortisol between pre and post 1.5 hour examination (Pre 0.03, 0.23, 0.13, 0.19, 0.13, 0.04 µg dl-1, Post 0.60, 0.31, 0.36, 0.24, 0.14, 0.16 µg dl-1). Though this methodology needs further investigation, this study suggests that blow sampling is a good candidate for non-invasive monitoring of cortisol in belugas. It can be collected from both wild and aquarium animals efficiently for the purposes of health monitoring and research, and may ultimately be useful in obtaining data on wild populations, including endangered species, which are difficult to handle directly.

  8. Blow Collection as a Non-Invasive Method for Measuring Cortisol in the Beluga (Delphinapterus leucas)

    PubMed Central

    Thompson, Laura A.; Spoon, Tracey R.; Goertz, Caroline E. C.; Hobbs, Roderick C.; Romano, Tracy A.

    2014-01-01

    Non-invasive sampling techniques are increasingly being used to monitor glucocorticoids, such as cortisol, as indicators of stressor load and fitness in zoo and wildlife conservation, research and medicine. For cetaceans, exhaled breath condensate (blow) provides a unique sampling matrix for such purposes. The purpose of this work was to develop an appropriate collection methodology and validate the use of a commercially available EIA for measuring cortisol in blow samples collected from belugas (Delphinapterus leucas). Nitex membrane stretched over a petri dish provided the optimal method for collecting blow. A commercially available cortisol EIA for measuring human cortisol (detection limit 35 pg ml−1) was adapted and validated for beluga cortisol using tests of parallelism, accuracy and recovery. Blow samples were collected from aquarium belugas during monthly health checks and during out of water examination, as well as from wild belugas. Two aquarium belugas showed increased blow cortisol between baseline samples and 30 minutes out of water (Baseline, 0.21 and 0.04 µg dl−1; 30 minutes, 0.95 and 0.14 µg dl−1). Six wild belugas also showed increases in blow cortisol between pre and post 1.5 hour examination (Pre 0.03, 0.23, 0.13, 0.19, 0.13, 0.04 µg dl−1, Post 0.60, 0.31, 0.36, 0.24, 0.14, 0.16 µg dl−1). Though this methodology needs further investigation, this study suggests that blow sampling is a good candidate for non-invasive monitoring of cortisol in belugas. It can be collected from both wild and aquarium animals efficiently for the purposes of health monitoring and research, and may ultimately be useful in obtaining data on wild populations, including endangered species, which are difficult to handle directly. PMID:25464121

  9. Computational analysis of forebody tangential slot blowing on the high alpha research vehicle

    NASA Technical Reports Server (NTRS)

    Gee, Ken

    1995-01-01

    A numerical analysis of forebody tangential slot blowing as a means of generating side force and yawing moment is conducted using an aircraft geometry. The Reynolds-averaged, thin-layer, Navier-Stokes equations are solved using a partially flux-split, approximately-factored algorithm. An algebraic turbulence model is used to determine the turbulent eddy viscosity values. Solutions are obtained using both patched and overset grid systems. In the patched grid model, and actuator plane is used to introduce jet variables into the flow field. The overset grid model is used to model the physical slot geometry and facilitate modeling of the full aircraft configuration. A slot optimization study indicates that a short slot located close to the nose of the aircraft provided the most side force and yawing moment per unit blowing coefficient. Comparison of computed surface pressure with that obtained in full-scale wind tunnel tests produce good agreement, indicating the numerical method and grid system used in the study are valid. Full aircraft computations resolve the changes in vortex burst point due to blowing. A time-accurate full-aircraft solution shows the effect of blowing on the changes in the frequency of the aerodynamic loads over the vertical tails. A study of the effects of freestream Mach number and various jet parameters indicates blowing remains effective through the transonic Mach range. An investigation of the force onset time lag associated with forebody blowing shows the lag to be minimal. The knowledge obtained in this study may be applied to the design of a forebody tangential slot blowing system for use on flight aircraft.

  10. Blow collection as a non-invasive method for measuring cortisol in the beluga (Delphinapterus leucas).

    PubMed

    Thompson, Laura A; Spoon, Tracey R; Goertz, Caroline E C; Hobbs, Roderick C; Romano, Tracy A

    2014-01-01

    Non-invasive sampling techniques are increasingly being used to monitor glucocorticoids, such as cortisol, as indicators of stressor load and fitness in zoo and wildlife conservation, research and medicine. For cetaceans, exhaled breath condensate (blow) provides a unique sampling matrix for such purposes. The purpose of this work was to develop an appropriate collection methodology and validate the use of a commercially available EIA for measuring cortisol in blow samples collected from belugas (Delphinapterus leucas). Nitex membrane stretched over a petri dish provided the optimal method for collecting blow. A commercially available cortisol EIA for measuring human cortisol (detection limit 35 pg ml-1) was adapted and validated for beluga cortisol using tests of parallelism, accuracy and recovery. Blow samples were collected from aquarium belugas during monthly health checks and during out of water examination, as well as from wild belugas. Two aquarium belugas showed increased blow cortisol between baseline samples and 30 minutes out of water (Baseline, 0.21 and 0.04 µg dl-1; 30 minutes, 0.95 and 0.14 µg dl-1). Six wild belugas also showed increases in blow cortisol between pre and post 1.5 hour examination (Pre 0.03, 0.23, 0.13, 0.19, 0.13, 0.04 µg dl-1, Post 0.60, 0.31, 0.36, 0.24, 0.14, 0.16 µg dl-1). Though this methodology needs further investigation, this study suggests that blow sampling is a good candidate for non-invasive monitoring of cortisol in belugas. It can be collected from both wild and aquarium animals efficiently for the purposes of health monitoring and research, and may ultimately be useful in obtaining data on wild populations, including endangered species, which are difficult to handle directly. PMID:25464121

  11. Identification of CFC and HCFC substitutes for blowing polyurethane foam insulation products. Report for September 1993-August 1994

    SciTech Connect

    Howard, P.H.; Tunkel, J.L.; Hendriks, R.V.

    1996-04-01

    The paper gives results of a systematic search to identify additional candidates as third-generation blowing agents, chemical compounds that are not stratospheric ozone depleters that can be used as substitutes for chlorofluorocarbon (CFC) and hydrochlorofluorocarbon (HCFC) blowing agents in rigid polyurethane foam insulating materials. To identify the most promising substitutes, potential third-generation blowing agents were ranked using a methodology developed for this project.

  12. Simulation on Decarburization and Inclusion Removal Process in the Ruhrstahl-Heraeus (RH) Process with Ladle Bottom Blowing

    NASA Astrophysics Data System (ADS)

    Geng, Dian-Qiao; Zheng, Jin-Xing; Wang, Kai; Wang, Ping; Liang, Ru-Quan; Liu, Hai-Tao; Lei, Hong; He, Ji-Cheng

    2015-03-01

    To enhance the refining efficiency of the Ruhrstahl-Heraeus (RH) process, the ladle bottom blowing was employed in RH degasser and a numerical method was employed to investigate the decarburization and inclusion removal in RH with ladle bottom blowing. The results showed that the decarburization rate in RH with ladle bottom blowing is greater than that in traditional RH. The larger mass fraction of carbon at the recirculation zone under up snorkel disappears because of the gas bubbles from ladle bottom blowing in an RH degasser. For RH with ladle bottom blowing, the decarburization at argon bubble surface accounts for the majority of the removed carbon, and it is approximately two times greater than that in the inner site of the vacuum chamber. Besides, the inclusion removal rate in RH with ladle bottom blowing is greater than that in traditional RH, and the maximum inclusion characteristic radius is much less in RH with ladle bottom blowing than that in traditional RH. Besides, the accumulation of inclusions in ladle between sidewall and up snorkel and the recirculation zone under up snorkel, which can be found in traditional RH, disappears in RH with ladle bottom blowing. For RH with ladle bottom blowing, the average number density of inclusions decreases more drastically than that in traditional RH and the average terminal number density of inclusions is much smaller than that in traditional RH.

  13. Numerical study of blow-up and dispersive shocks in solutions to generalized Korteweg-de Vries equations

    NASA Astrophysics Data System (ADS)

    Klein, C.; Peter, R.

    2015-06-01

    We present a detailed numerical study of solutions to general Korteweg-de Vries equations with critical and supercritical nonlinearity, both in the context of dispersive shocks and blow-up. We study the stability of solitons and show that they are unstable against being radiated away and blow-up. In the L2 critical case, the blow-up mechanism by Martel, Merle and Raphaël can be numerically identified. In the limit of small dispersion, it is shown that a dispersive shock always appears before an eventual blow-up. In the latter case, always the first soliton to appear will blow up. It is shown that the same type of blow-up as for the perturbations of the soliton can be observed which indicates that the theory by Martel, Merle and Raphaël is also applicable to initial data with a mass much larger than the soliton mass. We study the scaling of the blow-up time t∗ in dependence of the small dispersion parameter ɛ and find an exponential dependence t∗(ɛ) and that there is a minimal blow-up time t0∗ greater than the critical time of the corresponding Hopf solution for ɛ → 0. To study the cases with blow-up in detail, we apply the first dynamic rescaling for generalized Korteweg-de Vries equations. This allows to identify the type of the singularity.

  14. A consideration on the electric field formed by blowing snow particles

    NASA Astrophysics Data System (ADS)

    Omiya, Satoshi; Sato, Atsushi

    2013-04-01

    Fluctuations of the atmospheric electric field strength have been reported during blowing snow events. A primary factor of this phenomenon is the electrification of the blowing snow particles. Electric force applied to the blowing snow particles may be a contributing factor in the formation of snow drifts and snow cornices and changing particles' trajectory motion. These can cause natural disaster such as an avalanche and visibility deterioration. Therefore, charging phenomenon of the blowing snow particles is an important issue in terms of not only precise understanding of the particle motion but disaster prevention. The purpose of this study was to clarify the fluctuation characteristics of the electric field. In previous studies, some numerical models have been proposed; however, these models did not consider the dependency of the particle charges on the particle diameter or the height dependency of the horizontal mass flux. Taking into account those dependencies, we estimated the vertical electric field distribution. In this study, an experimental equation (Omiya et al., 2011), which can estimate the individual particle charge from the particle diameter and the air temperature, was used. In addition, the approximation equations of the vertical distribution of wind speed, the horizontal mass flux, and the average particle diameter were also used. A hot-wire anemometer was used to measure the wind speed. A snow particle counter (SPC) was used to measure the horizontal mass flux and the particle diameter distribution. This experiment was conducted in a cold wind tunnel (Ice and Snow Research Center, NIED, JAPAN) at an air temperature of -10 degree Celsius. In this calculation, for simplicity, some assumptions were considered; 1) The particle diameter and the particle number density are horizontally constant and uniform. (The electric field formed by the blowing snow particles is uniform horizontally.) 2) All the blowing snow particles are electrified negatively

  15. On the effect of leading edge blowing on circulation control airfoil aerodynamics

    NASA Technical Reports Server (NTRS)

    Mclachlan, B. G.

    1987-01-01

    In the present context the term circulation control is used to denote a method of lift generation that utilizes tangential jet blowing over the upper surface of a rounded trailing edge airfoil to determine the location of the boundary layer separation points, thus setting an effective Kutta condition. At present little information exists on the flow structure generated by circulation control airfoils under leading edge blowing. Consequently, no theoretical methods exist to predict airfoil performance under such conditions. An experimental study of the flow field generated by a two dimensional circulation control airfoil under steady leading and trailing edge blowing was undertaken. The objective was to fundamentally understand the overall flow structure generated and its relation to airfoil performance. Flow visualization was performed to define the overall flow field structure. Measurements of the airfoil forces were also made to provide a correlation of the observed flow field structure to airfoil performance. Preliminary results are presented, specifically on the effect on the flow field structure of leading edge blowing, alone and in conjunction with trailing edge blowing.

  16. Scattering and sequestering of blow-up moduli in local string models

    NASA Astrophysics Data System (ADS)

    Conlon, Joseph P.; Witkowski, Lukas T.

    2011-12-01

    We study the scattering and sequestering of blow-up fields - either local to or distant from a visible matter sector - through a CFT computation of the dependence of physical Yukawa couplings on the blow-up moduli. For a visible sector of D3-branes on orbifold singularities we compute the disk correlator left< {tau_s^{{(1)}}tau_s^{{(2)}}...tau_s^{{(n)}}ψ ψ φ } rightrangle between orbifold blow-up moduli and matter Yukawa couplings. For n = 1 we determine the full quantum and classical correlator. This result has the correct factorisation onto lower 3-point functions and also passes numerous other consistency checks. For n > 1 we show that the structure of picture-changing applied to the twist operators establishes the sequestering of distant blow-up moduli at disk level to all orders in α'. We explain how these results are relevant to suppressing soft terms to scales parametrically below the gravitino mass. By giving vevs to the blow-up fields we can move into the smooth limit and thereby derive CFT results for the smooth Swiss-cheese Calabi-Yaus that appear in the Large Volume Scenario.

  17. Numerical analysis of tangential slot blowing on a generic chined forebody

    NASA Technical Reports Server (NTRS)

    Agosta, Roxana M.

    1994-01-01

    A numerical study is performed to investigate the effects of tangential slot blowing on a generic chined forebody. The Reynolds-averaged, thin-layer, Navier-Stokes equations are solved to obtain the high-angle-of-attack viscous flow field about a generic chined forebody. Tangential slot blowing is investigated as a means of forebody flow control to generate side force and yawing moment on the forebody. The effects of jet mass flow ratios, angle of attack, and blowing slot location in the axial and circumferential directions are studied. The computed results are compared with available wind tunnel experimental data. The solutions with and without blowing are also analyzed using helicity density contours, surface flow patterns, and off-surface instantaneous streamlines. The results of this analysis provide details of the flow field about the generic chined forebody, as well as show that tangential slot blowing can be used as a means of forebody flow control to generate side force and yawing moment.

  18. Management of orbital blow-out fractures. Case reports and discussion.

    PubMed

    Forrest, L A; Schuller, D E; Strauss, R H

    1989-01-01

    Blow-out fractures are fractures of the orbital floor or medial wall that occur as a consequence of blunt trauma. Impact increases the intraorbital pressure, forcing the nondistensible orbital contents through the orbital floor. The fracture is commonly caused by impact from a baseball or tennis ball. However, any blunt trauma to the orbit, as from a knee or elbow, can result in a blow-out fracture. The characteristic clinical findings include double vision, a sunken globe, and numbness in the distribution of the infraorbital nerve. Sometimes, the only sign of a blow-out fracture is the abrupt inflation of periorbital tissue with air when the patient blows his nose. Standard evaluation of these fractures includes history, physical examination, and radiographs. Some patients benefit from computed tomography (CT), which can be both diagnostic and prognostic. Blow-out fractures do not often produce serious sequelae, and the current trend is toward no treatment. However, it is imperative to rule out any serious injury to the eye itself that would require emergency treatment.

  19. Analysis of interaction in binary odorant mixtures.

    PubMed

    Smith, B H

    1998-12-01

    An understanding of the olfactory system of any animal must account for how odor mixtures are perceived and processed. The present experiments apply associationist models to the study of how elements are processed in binary odorant mixtures. Using experimental designs for Proboscis Extension Conditioning of honey bees, I show that learning about a pure odorant element is frequently affected by its occurrence in a mixture with a second odorant. Presence of a background odor when an odorant is associated with sucrose reinforcement decreases the rate and/or asymptotic level of associative strength that accumulates to that odorant. This interaction is in part due to synthetic qualities that arise in sensory transduction and initial processing. In addition, it involves an attention-like processing system like that involved in overshadowing. Therefore, a model that includes representations of the component and configural qualities of odorants in mixtures is needed to provide a more complete account of learning about odor mixtures. PMID:9877404

  20. Free-Flight Evaluation of Forebody Blowing for Yaw Control at High Angels of Attack

    NASA Technical Reports Server (NTRS)

    Kiddy, Jason

    1995-01-01

    Forebody blowing is a concept developed to provide yaw control for aircraft flying at high angles of attack where a conventional rudder becomes ineffective. The basic concept is fairly simple. A small jet of air is forced out of the nose of the aircraft. This jet causes a repositioning of the forebody vortices in an asymmetrical fashion. The asymmetric forebody vortex flows develop a side force on the forebody which results in substantial yawing moments at high angles of attack. The purpose of this project was to demonstrate the use of forebody blowing as a control device through free-flight evaluation. This unique type of testing was performed at the NASA-Langley 30- by 60-foot tunnel. From these tests, it could then be shown that forebody blowing is an effective method of maintaining yaw control at high angles of attack.

  1. Effects of wall suction/blowing on two-dimensional flow past a confined square cylinder.

    PubMed

    Zhang, Wei; Jiang, Yanqun; Li, Lang; Chen, Guoping

    2016-01-01

    A numerical simulation is conducted to study the laminar flow past a square cylinder confined in a channel (the ratio of side length of the square to channel width is fixed at 1/4) subjected to a locally uniform blowing/suction speed placed at the top and bottom channel walls. Governing equations with boundary conditions are resolved using a finite volume method in pressure-velocity formulation. The flow patterns relevant to the critical spacing values are investigated. Numerical results show that wall blowing has a stabilizing effect on the flow, and the corresponding critical Reynolds number increases monotonically with increasing blowing velocity. Remarkably, steady asymmetric solutions and hysteretic mode transitions exist in a certain range of parameters (Reynolds number and suction speed) in the case of suction. PMID:27462481

  2. Computational study of the aerodynamics and control by blowing of asymmetric vortical flows over delta wings

    NASA Technical Reports Server (NTRS)

    Craig, Ken

    1991-01-01

    Some of the work is described which was done in a study of the flow field produced by tangential leading edge blowing on a 60 deg. delta wing. The flow is studied computationally by solving the Thin Layer Navier-Stokes equations. Steady state flow fields are calculated for various angles of attack and yaw, with and without the presence of tangential leading edge blowing. The effectiveness of blowing as a rolling moment control mechanism to extend the envelope of controllability is illustrated at pre- and post-stall angles of attack. The numerical grid is generated using algebraic grid generation and various interpolation and blending techniques. The jet emanates from a slot with linearly varying thickness and is introduced into the flow field using the concept of an actuator plane, thereby not requiring resolution of the jet slot geometry. The Baldwin-Lomax algebraic turbulence model is used to provide turbulent closure. The computational results are compared with those of experiments.

  3. Blow fly maggots (Diptera: Calliphoridae)from a human corpse in a vehicle.

    PubMed

    Sribanditmongkol, Pongruk; Monum, Tawachai; Wannasan, Anchalee; Tomberlin, Jeffery K; Sukontason, Kom; Sukontason, Kabkaew L

    2014-09-01

    Correct species identification and development data of insects associated with a cadaver can help estimate the time of colonization which could be used to infer a minimal post-mortem interval (minPMI) for forensic investigations. Human remains are found in a variety of locations ranging from open fields to inside automobiles. We report the investigation of blow fly larvae collected from a decomposing body located in the trunk of a car. There were two blow fly (Diptera: Calliphoridae) species: Achoetandrus rufifacies (Macquart) and Chrysomya megacephala (Fabricius). Blow flies can enter the vehicle and colonize human remains. Based on age estimations of third stage larvae of A. rufifacies, the minPMI was estimated to be 4-5 days, which was within the range of 3-5 days estimated by other forensically relevant information.

  4. Developing and teaching the virtue-ethics foundations of healthcare whistle blowing.

    PubMed

    Faunce, Thomas

    2004-10-01

    Healthcare whistle blowing, despite the benefits it has brought to healthcare systems in many developed countries, remains generally regarded as a pariah activity by many of the most influential healthcare professionals and regulatory institutions. Few if any medical schools or law department health law and bioethics classes, teach whistle blowing in a formal sense. Yet without exception, public inquiries initiated by healthcare whistle blowers have validated their central allegations and demonstrated that the whistle blowers themselves were sincere in their desire to implement the fundamental virtues and principles of medical ethics, bioethics and public health law. In many jurisdictions, the law, this time remarkably in advance of professional opinion, has offered legislative protection for reasonable allegations of whistleblowers made in good faith and in the public interest concerning a substantial and imminent threat to public safety. One reason for this paradoxical position, explored here, is that healthcare whistle blowing lacks a firm virtue-based theoretical bioethical and jurisprudential foundation. The hypothesis discussed is that the lack of this bioethical and jurisprudential substrate has contributed to a situation where healthcare whistle blowing suffers in terms of institutional support due to its lack of academic legitimacy. This article commences the process of redressing this imbalance by attempting to lay the theoretical foundations for healthcare whistle blowing. As a case study, this article concludes by discussing the Personal and Professional Development course at the ANU Medical School where healthcare whistle blowing is a formal part of a virtue-based curriculum that emphasises the foundational importance of conscience. Illustrative elements of that program are discussed.

  5. Self-Inflicted Hammer Blows to the Cranial Vault: An Interdisciplinary Challenge

    PubMed Central

    Kim, Seong Woong; Putzke, Michael; Uhl, Eberhard; Krishnan, Kartik G.

    2016-01-01

    Depression is predicted to be the most common cause of disability in the coming decade. Self-inflicted hammer blow to the cranium is a rare phenomenon seen in patients with a history of attempted suicide. The resulting comminuted depressed skull fracture of the midline vertex is life threatening. Rapid interdisciplinary communication and intervention are essential to reduce morbidity and mortality. We present a case of self-inflicted hammer blows to the head, review the relevant literature on this topic, and discuss neurosurgical and psychiatric implications. PMID:27722022

  6. Aerodynamic analysis of VTOL inlets and definition of a short, blowing-lip inlet

    NASA Technical Reports Server (NTRS)

    Syberg, J.; Jones, A. L.

    1982-01-01

    The results indicated that, without boundary layer control, either a very long inlet or an inlet with a very high contraction ratio lip will be required to meet the stringent design requirements. It is shown that active boundary layer control is an effective means of preventing separation and that a significant reduction in inlet size can be achieved by removing only a small amount of bleed in the throat region of the inlet. A short, blowing-lip model was designed and fabricated. This model features an adjustable, blowing slot located near the hilite on the windward side of the inlet.

  7. On the sublimation of blowing snow and of snow in canopies

    NASA Astrophysics Data System (ADS)

    Taylor, P. A.; Simon, K.; Gordon, M.; Weng, W.

    2003-04-01

    Tests have been made within the Canadian Land Surface Scheme (CLASS) of various parameterizations of sublimation of blowing snow, and tested in the context of data from weather stations (Goose Bay and Resolute) in northern Canada. We will focus on parameterization schemes based on results obtained with the PIEKTUK model of blowing snow. In addition we will present preliminary results concerning the parameterization of sublimation of snow caught in tree canopies, using schemes similar to those for evaporation from wet canopies. This is considered to be a major factor in the water budgets of forested areas in northern Canada.

  8. The classic: The treatment of chronic osteomyelitis with the maggot (larva of the blow fly). 1931.

    PubMed

    Baer, William S

    2011-04-01

    This Classic article is a reprint of the original work by William S. Baer, MD, The Treatment of Chronic Osteomyelitis With the Maggot (Larva of the Blow Fly). An accompanying biographical sketch on William Baer, is available at DOI 10.1007/s11999-010-1415-4 . The Classic Article is ©1931 by the Journal of Bone and Joint Surgery, Inc. and is reprinted with permission from Baer WS. The treatment of chronic osteomyelitis with the maggot (larva of the blow fly). J Bone Joint Surg Am. 1931;13:438-475.

  9. Noise Benefits of Rotor Trailing Edge Blowing for a Model Turbofan

    NASA Technical Reports Server (NTRS)

    Woodward, Richard P.; Fite, E. Brian; Podboy, Gary G.

    2007-01-01

    An advanced model turbofan was tested in the NASA Glenn 9- by 15-Foot Low Speed Wind Tunnel (9x15 LSWT) to explore far field acoustic effects associated with rotor Trailing-Edge-Blowing (TEB) for a modern, 1.294 stage pressure ratio turbofan model. The TEB rotor (Fan9) was designed to be aerodynamically similar to the previously tested Fan1, and used the same stator and nacelle hardware. Fan9 was designed with trailing edge blowing slots using an external air supply directed through the rotor hub. The TEB flow was heated to approximate the average fan exit temperature at each fan test speed. Rotor root blockage inserts were used to block TEB to all but the outer 40 and 20% span in addition to full-span blowing. A configuration with full-span TEB on alternate rotor blades was also tested. Far field acoustic data were taken at takeoff/approach conditions at 0.10 tunnel Mach. Far-field acoustic results showed that full-span blowing near 2.0% of the total flow could reduce the overall sound power level by about 2 dB. This noise reduction was observed in both the rotor-stator interaction tones and for the spectral broadband noise levels. Blowing only the outer span region was not very effective for lowering noise, and actually increased the far field noise level in some instances. Full-span blowing of alternate blades at 1.0% of the overall flow rate (equivalent to full-span blowing of all blades at 2.0% flow) showed a more modest noise decrease relative to full-span blowing of all blades. Detailed hot film measurements of the TEB rotor wake at 2.0% flow showed that TEB was not every effective for filling in the wake defect at approach fan speed toward the tip region, but did result in overfilling the wake toward the hub. Downstream turbulence measurements supported this finding, and support the observed reduction in spectral broadband noise.

  10. Investigations on the processing of solid silicon rubber in blow moulding

    NASA Astrophysics Data System (ADS)

    Hopmann, Ch.; Funk, A.; Windeck, C.

    2015-05-01

    Complex hollow parts made of thermoplastics are often produced in the extrusion blow moulding process. This cost-efficient production technique with a high reproducibility, a high degree of automation and short cycle times has not been adapted for rubber processing until now. Current research activities at IKV focus on the processing of silicone rubber in extrusion blow moulding with an adapted processing and rapid cross-linking systems. The blow moulding process allows an automated and effective production of complex hollow parts made of solid silicone rubber in one step. The use of expensive core techniques, which lead to comparatively high reject rates in injection moulding, is not necessary. Expensive and time-consuming assembly steps can be reduced. This substantially increases the efficiency of the process. A systematic material selection of different solid silicone rubber compounds and cross-linking systems for the extrusion blow moulding process is a major focus of investigation. In this context, the term blow mouldability of polymers is defined and the suitability of solid silicone rubbers in combination with cross-linking systems for the blow moulding process is analysed. Characteristic mechanical and physical properties allow the identification of suitable material systems and give advice for the implementation of the new process. Extrusion blow moulding of solid silicone rubber is a new and innovative manufacturing concept to produce elastomeric hollow parts. Influences on the forming process are not known for silicone rubber yet. Therefore, to obtain a detailed process description is another focus of the research project. This includes the forming process, the processing and the influences of the material and the curing reaction on the processing. In the first instance, the investigation and description of the forming process as well as the detailed analysis of the processing parameters, such as curing time, mould temperature, wall thickness of the

  11. Blow-up conditions for two dimensional modified Euler-Poisson equations

    NASA Astrophysics Data System (ADS)

    Lee, Yongki

    2016-09-01

    The multi-dimensional Euler-Poisson system describes the dynamic behavior of many important physical flows, yet as a hyperbolic system its solution can blow-up for some initial configurations. This article strives to advance our understanding on the critical threshold phenomena through the study of a two-dimensional modified Euler-Poisson system with a modified Riesz transform where the singularity at the origin is removed. We identify upper-thresholds for finite time blow-up of solutions for the modified Euler-Poisson equations with attractive/repulsive forcing.

  12. Hosing Instability in the Blow-Out Regime for Plasma-Wakefield Acceleration

    SciTech Connect

    Huang, C.; Lu, W.; Zhou, M.; Clayton, C. E.; Joshi, C.; Mori, W. B.; Muggli, P.; Deng, S.; Oz, E.; Katsouleas, T.; Hogan, M. J.; Blumenfeld, I.; Decker, F. J.; Ischebeck, R.; Iverson, R. H.; Kirby, N. A.; Walz, D.

    2007-12-21

    The electron hosing instability in the blow-out regime of plasma-wakefield acceleration is investigated using a linear perturbation theory about the electron blow-out trajectory in Lu et al. [in Phys. Rev. Lett. 96, 165002 (2006)]. The growth of the instability is found to be affected by the beam parameters unlike in the standard theory Whittum et al. [Phys. Rev. Lett. 67, 991 (1991)] which is strictly valid for preformed channels. Particle-in-cell simulations agree with this new theory, which predicts less hosing growth than found by the hosing theory of Whittum et al.

  13. Hosing Instability in the Blow-Out Regime for Plasma-Wakefield Acceleration

    SciTech Connect

    Huang, C.; Lu, W.; Zhou, M.; Clayton, C.E.; Joshi, C.; Mori, W.B.; Muggli, P.; Deng, S.; Oz, E.; Katsouleas, T.; Hogan, M.J.; Blumenfeld, I.; Decker, F.J.; Ischebeck, R.; Iverson, R.H.; Kirby, N.A.; Walz, D.; /SLAC

    2008-02-13

    The electron hosing instability in the blow-out regime of plasma-wakefield acceleration is investigated using a linear perturbation theory about the electron blow-out trajectory in Lu et al. [in Phys. Rev. Lett. 96, 165002 (2006)]. The growth of the instability is found to be affected by the beam parameters unlike in the standard theory Whittum et al. [Phys. Rev. Lett. 67, 991 (1991)] which is strictly valid for preformed channels. Particle-in-cell simulations agree with this new theory, which predicts less hosing growth than found by the hosing theory of Whittum et al.

  14. Investigations of transonic buffet control on civil aircraft wing with the use of tangential jet blowing

    NASA Astrophysics Data System (ADS)

    Abramova, K. A.; Petrov, A. V.; Potapchick, A. V.; Soudakov, V. G.

    2016-10-01

    Numerical and experimental investigations of transonic buffet control by tangential jet blowing are presented. To suppress the shock-induced boundary layer separation and the buffet at transonic speeds, compressed air jet is blown through a small slot nozzle tangentially to the upper surface of the supercritical airfoil. Numerical simulations were carried out on the basis of the unsteady Reynolds averaged Navier-Stokes (URANS) equations. Experimental studies of the tangential jet blowing were performed in the transonic wind tunnel T-112 of TsAGI. Results show that the jet moves the shock downstream, increases lift, suppresses flow separation under shock foot and delays buffet onset.

  15. Research and Analysis on the Physical and Chemical Properties of Molten Bath with Bottom-Blowing in EAF Steelmaking Process

    NASA Astrophysics Data System (ADS)

    Wei, Guangsheng; Zhu, Rong; Dong, Kai; Ma, Guohong; Cheng, Ting

    2016-10-01

    Bottom-blowing technology is widely adopted in electric arc furnace (EAF) steelmaking to promote the molten bath fluid flow, accelerate the metallurgical reaction, and improve the quality of molten steel. In this study, a water model experiment and a computational fluid dynamics model were established to investigate the effects of bottom-blowing gas flow rate on the fluid flow characteristics in the EAF molten bath. The results show that the interaction among the bottom-blowing gas streams influences the molten bath flow field, and increasing the bottom-blowing gas flow rate can accelerate the fluid flow and decrease the volume of the dead zone. Based on industrial application research, the physical and chemical properties of the molten bath with bottom-blowing were analyzed. Compared with traditional melting conditions without bottom-blowing, bottom-blowing technology demonstrates obvious advantages in promoting the heat transfer and metallurgical reactions in the molten bath. With the bottom-blowing arrangement, the dephosphorization and decarburization rates are accelerated, the contents of FeO and T. Fe in endpoint slag are decreased, and the endpoint carbon-oxygen equilibrium of molten steel is improved.

  16. Research and Analysis on the Physical and Chemical Properties of Molten Bath with Bottom-Blowing in EAF Steelmaking Process

    NASA Astrophysics Data System (ADS)

    Wei, Guangsheng; Zhu, Rong; Dong, Kai; Ma, Guohong; Cheng, Ting

    2016-06-01

    Bottom-blowing technology is widely adopted in electric arc furnace (EAF) steelmaking to promote the molten bath fluid flow, accelerate the metallurgical reaction, and improve the quality of molten steel. In this study, a water model experiment and a computational fluid dynamics model were established to investigate the effects of bottom-blowing gas flow rate on the fluid flow characteristics in the EAF molten bath. The results show that the interaction among the bottom-blowing gas streams influences the molten bath flow field, and increasing the bottom-blowing gas flow rate can accelerate the fluid flow and decrease the volume of the dead zone. Based on industrial application research, the physical and chemical properties of the molten bath with bottom-blowing were analyzed. Compared with traditional melting conditions without bottom-blowing, bottom-blowing technology demonstrates obvious advantages in promoting the heat transfer and metallurgical reactions in the molten bath. With the bottom-blowing arrangement, the dephosphorization and decarburization rates are accelerated, the contents of FeO and T. Fe in endpoint slag are decreased, and the endpoint carbon-oxygen equilibrium of molten steel is improved.

  17. Metal mixtures modeling evaluation project: 1. Background.

    PubMed

    Meyer, Joseph S; Farley, Kevin J; Garman, Emily R

    2015-04-01

    Despite more than 5 decades of aquatic toxicity tests conducted with metal mixtures, there is still a need to understand how metals interact in mixtures and to predict their toxicity more accurately than what is currently done. The present study provides a background for understanding the terminology, regulatory framework, qualitative and quantitative concepts, experimental approaches, and visualization and data-analysis methods for chemical mixtures, with an emphasis on bioavailability and metal-metal interactions in mixtures of waterborne metals. In addition, a Monte Carlo-type randomization statistical approach to test for nonadditive toxicity is presented, and an example with a binary-metal toxicity data set demonstrates the challenge involved in inferring statistically significant nonadditive toxicity. This background sets the stage for the toxicity results, data analyses, and bioavailability models related to metal mixtures that are described in the remaining articles in this special section from the Metal Mixture Modeling Evaluation project and workshop. It is concluded that although qualitative terminology such as additive and nonadditive toxicity can be useful to convey general concepts, failure to expand beyond that limited perspective could impede progress in understanding and predicting metal mixture toxicity. Instead of focusing on whether a given metal mixture causes additive or nonadditive toxicity, effort should be directed to develop models that can accurately predict the toxicity of metal mixtures.

  18. How to Blow a Bubble in a Galaxy

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2015-10-01

    outflow from a startburst concentrated near the nuclei. Either of these outflows could blow a bubble as it first interacts with the interstellar medium.The authors show that the first category is disfavored based on observational and energetics arguments. In addition, the western-most nucleus and the bubble both align exactly with the axis of the large-scale outflows of the galaxy. Unlikely to be due to chance, this alignment is strong support in favor of the second category.Thus, its probable that the bubble is blown by an outflow that originates from the inner ~100pc around one of the nuclei, either due to a jet or a starburst wind. Further observations should be able to differentiate between these two mechanisms.CitationKelly E. Lockhart et al 2015 ApJ 810 149. doi:10.1088/0004-637X/810/2/149

  19. Huge "Superbubble" of Gas Blowing Out of Milky Way

    NASA Astrophysics Data System (ADS)

    2006-01-01

    out of the plane has to have been unusually violent," he added. The scientists speculate that the gas may be blown outward by the strong stellar winds and supernova explosions from numerous massive young stars in a cluster. "One theoretical model shows that young stars could power an outflow that matches what we see very closely," Pidopryhora said. According to that model, the superbubble probably is 10-30 million years old. "Finding this superbubble practically in our back yard is quite exciting, because these superbubbles are very important factors in how galaxies evolve," Lockman said. Superbubbles, powered by supernova explosions and young stellar winds, control the way heavy elements, produced only in the cores of stars, are distributed throughout the galaxy, the scientists said. Those heavy elements are then incorporated into the next generation of stars -- and planets -- to form. "The formation of our own Sun and planets probably was heavily influenced, if not triggered, by a nearby supernova explosion," Lockman said. In addition, if the outflow from superbubbles is energetic enough, it could blow the gas into intergalactic space, never to return to the galaxy. "This would shut down the formation of new stars in the galaxy," Pidopryhora explained. The Green Bank Telescope, dedicated in 2000, is the largest fully-steerable radio telescope in the world, with more than two acres of collecting area in its giant dish. Located within the National Radio Quiet Zone in West Virginia, the GBT provides extraordinary sensitivity for observing faint radio-emitting objects in the distant Universe. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

  20. Phylogenetic mixture models for proteins.

    PubMed

    Le, Si Quang; Lartillot, Nicolas; Gascuel, Olivier

    2008-12-27

    Standard protein substitution models use a single amino acid replacement rate matrix that summarizes the biological, chemical and physical properties of amino acids. However, site evolution is highly heterogeneous and depends on many factors: genetic code; solvent exposure; secondary and tertiary structure; protein function; etc. These impact the substitution pattern and, in most cases, a single replacement matrix is not enough to represent all the complexity of the evolutionary processes. This paper explores in maximum-likelihood framework phylogenetic mixture models that combine several amino acid replacement matrices to better fit protein evolution.We learn these mixture models from a large alignment database extracted from HSSP, and test the performance using independent alignments from TREEBASE.We compare unsupervised learning approaches, where the site categories are unknown, to supervised ones, where in estimations we use the known category of each site, based on its exposure or its secondary structure. All our models are combined with gamma-distributed rates across sites. Results show that highly significant likelihood gains are obtained when using mixture models compared with the best available single replacement matrices. Mixtures of matrices also improve over mixtures of profiles in the manner of the CAT model. The unsupervised approach tends to be better than the supervised one, but it appears difficult to implement and highly sensitive to the starting values of the parameters, meaning that the supervised approach is still of interest for initialization and model comparison. Using an unsupervised model involving three matrices, the average AIC gain per site with TREEBASE test alignments is 0.31, 0.49 and 0.61 compared with LG (named after Le & Gascuel 2008 Mol. Biol. Evol. 25, 1307-1320), WAG and JTT, respectively. This three-matrix model is significantly better than LG for 34 alignments (among 57), and significantly worse for 1 alignment only. Moreover

  1. Chinese Herbal Mixture, Tien-Hsien Liquid, Induces G2/M Cycle Arrest and Radiosensitivity in MCF-7 Human Breast Cancer Cells through Mechanisms Involving DNMT1 and Rad51 Downregulation

    PubMed Central

    Chow, Jyh-Ming; Yang, Chia-Ming; Kuo, Hui-Ching; Chang, Chia-Lun; Lee, Hsin-Lun; Lai, I-Chun; Chuang, Shuang-En

    2016-01-01

    The Chinese herbal mixture, Tien-Hsien Liquid (THL), has been proven to suppress the growth and invasiveness of cancer cells and is currently regarded as a complementary medicine for the treatment of cancer. Our previous study using acute promyelocytic leukemia cells uncovered its effect on the downregulation of DNA methyltransferase 1 (DNMT1) which is often overexpressed in cancer cells resulting in the repression of tumor suppressors via hypermethylation. Herein, we explored the effects of THL in MCF-7 breast cancer cells that also demonstrate elevated DNMT1. The results show that THL dose-dependently downregulated DNMT1 accompanied by the induction of tumor suppressors such as p21 and p15. THL arrested cell cycle in G2/M phase and decreased the protein levels of cyclin A, cyclin B1, phospho-pRb, and AKT. DNMT1 inhibition was previously reported to exert a radiosensitizing effect in cancer cells through the repression of DNA repair. We found that THL enhanced radiation-induced clonogenic cell death in MCF-7 cells and decreased the level of DNA double-strand break repair protein, Rad51. Our observations may be the result of DNMT1 downregulation. Due to the fact that DNMT1 inhibition is now a mainstream strategy for anticancer therapy, further clinical trials of THL to confirm its clinical efficacy are warranted. PMID:27525019

  2. Current state and prospects of researches on the control of turbulent boundary layer by air blowing

    NASA Astrophysics Data System (ADS)

    Kornilov, V. I.

    2015-07-01

    The paper presents the analytical review of the current state of the investigations and development trends on the problem of turbulent friction and aerodynamic drag reduction in simple model configurations, which is among key ones in modern aeromechanics. Under consideration is the modern fast progressing method of the turbulent flow control by air- and other gases (micro)blowing through a permeable surface, which is utilized in incompressible and compressible turbulent boundary layers. Several computational results to understand the essential flow physics are also included. The problem of simulation of the flow over a perforated wall where some ambiguities, in particular, at the permeable/impermeable boundary being still remained is discussed. Special attention is paid to the analysis of most important experimental and numerical results obtained with the air blowing through a finely-perforated surface, analysis of the physical peculiarities and regularities of the flow with the blowing, probability to describe the properties of such a flow within simple approach frameworks, evaluation of the efficiency of this control method, as well as the trends and opportunities of this method progress in view of state-of-the-art achievements. Although this technology has a penalty for developing the effective turbulent-flow control method, some modifications of the air blowing are an attractive alternative for real applications.

  3. Academic Misconduct: A Goals-Plans-Action Approach to Peer Confrontation and Whistle-Blowing

    ERIC Educational Resources Information Center

    Henningsen, Mary Lynn Miller; Valde, Kathleen S.; Denbow, Jessica

    2013-01-01

    Academic misconduct is a serious, pervasive, communication phenomenon on college campuses. In this study, the goals-plans-action model (Dillard, 1990) was used as a theoretical framework to investigate peer confrontation of cheating and whistle-blowing to a course instructor. In an experiment, participants were asked to respond to measures of…

  4. Compressed Air System Modifications Improve Efficiency at a Plastics Blow Molding Plant (Southeastern Container Plant)

    SciTech Connect

    2001-06-01

    This case study is one in a series on industrial firms who are implementing energy efficient technologies and system improvements into their manufacturing processes. This case study documents the activities, savings, and lessons learned on the plastics blow molding plant project.

  5. The American Economy: A Fuse About to Blow? Fundamentals of Free Enterprise, No. 6.

    ERIC Educational Resources Information Center

    American Fletcher National Bank and Trust Co., Indianapolis, IN.

    Designed for high school economics students as a public service project of the American Fletcher National Bank, the booklet examines the heavy burdens placed on our political-economic system and compares our economy to an overloaded electrical system about to "blow a fuse." In the last two decades, America has become a self-indulgent society which…

  6. A Paradigm for Operant Conditioning in Blow Flies ("Phormia Terrae Novae" Robineau-Desvoidy, 1830)

    ERIC Educational Resources Information Center

    Sokolowski, Michel B. C.; Disma, Gerald; Abramson, Charles I.

    2010-01-01

    An operant conditioning situation for the blow fly ("Protophormia terrae novae") is described. Individual flies are trained to enter and reenter a hole as the operant response. Only a few sessions of contingent reinforcement are required to increase response rates. When the response is no longer followed by food, the rate of entering the hole…

  7. A test of Automatic Blowing snow Station (ABS) in the French Alps

    NASA Astrophysics Data System (ADS)

    Ito, Yoichi; Naaim-Bouvet, Florence; Nishimura, Kouichi; Bellot, Hervé; Fontaine, Firmin

    2015-04-01

    Blowing snow is a significant factor to estimate snow distribution in alpine, Arctic and Antarctic regions. The Snow Particle Counter (SPC) is well used for mass flux measurement of the blowing snow, however, the SPC deployment is not always possible for automatic observation under harsh conditions. Recently Automatic Blowing snow Station (ABS), which is a simpler device than the SPC, have been developed in Japan. We installed the ABS system with the SPCs at the Lac Blanc Pass in the French Alps (2700 m a.s.l.) to examine the relationship between the ABS output and snow particle mass flux. The ABS worked well, without problems, for the entire 4-month period in the winter 2014. The ABS output was converted to mass flux using wind-dependent power function which obtained from calibration procedure in a cold wind-tunnel. The mass flux obtained from the ABS showed a good agreement with the SPC, particularly around the peak of blowing snow event. Based on tests under controlled (cold wind-tunnel) and field conditions, we conclude that the ABS is suitable for practical use.

  8. A Molecular Key for the Identification of Blow Flies in Southeastern Nebraska

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The identification of blow flies (Calliphoridae) (typically the first colonizers of cadavers) is difficult, especially in the earlier instars because of their small size, similarity and simplicity in external morphology. We consider how taxonomic keys based on molecular genetic data facilitate accur...

  9. Solution blow spun Poly(lactic acid)/Hydroxypropyl methylcellulose nanofibers with antimicrobial properties

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Poly(lactic acid) (PLA) nanofibers containing hydroxypropyl methylcellulose (HPMC) and tetracycline hydrochloride (THC) were solution blow spun from two different solvents, chloroform/acetone (CA, 80:20 v/v) and 2,2,2-triflouroethanol (TFE). The diameter distribution, chemical, thermal, thermal stab...

  10. BEARDSLEY AND PIPER (B&P) CORE BLOWING MACHINE. VIRGINIA BLAKELY MANUALLY ...

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

    BEARDSLEY AND PIPER (B&P) CORE BLOWING MACHINE. VIRGINIA BLAKELY MANUALLY FILLING SAND MAGAZINE THAT WILL ROTATE WITH THE CORE BOX, FILLING IT UNDER PRESSURE SIMILAR TO THE CORE MACHINE IN THE BACKGROUND. - Southern Ductile Casting Company, Core Making, 2217 Carolina Avenue, Bessemer, Jefferson County, AL

  11. Generalized Nehari functionals and finite time blow up of the solutions to Boussinesq equation

    NASA Astrophysics Data System (ADS)

    Kolkovska, N.; Dimova, M.; Kutev, N.

    2015-10-01

    We study the Cauchy problem to generalized Boussinesq equation with linear restoring force and combined power type nonlinearities. Generalized Nehari functionals are introduced and their monotonicity and sign preserving properties are established. By means of an extension of the concavity method of Levine and generalized Nehari functionals finite time blow up of the solutions with arbitrary high positive initial energy is proved.

  12. Unsavory Problems at Tasty's: A Role-Play about Whistle-Blowing

    ERIC Educational Resources Information Center

    Comer, Debra R.; Vega, Gina

    2006-01-01

    This article presents a role-play exercise to make the topic of whistle-blowing personally salient to undergraduates. Students identify with the prospective whistle-blower, whose decision affects several stakeholders. The protagonist merely suspects her manager of stealing, until she hears concrete evidence of his thefts from her assistant…

  13. Whistle-Blowing as a Form of Advocacy: Guidelines for the Practitioner and Organization

    ERIC Educational Resources Information Center

    Greene, Annette D.; Latting, Jean Kantambu

    2004-01-01

    Advocacy has been an inherent component of social work since the mid-1800s. The NASW Code of Ethics explicitly promotes advocacy as an ethical stance against inhumane conditions. Whistle-blowing, on the other hand, occurs mostly in the business and public administration disciplines and is relatively unknown in the social work profession. Using…

  14. DNS on control of laminar-turbulent transition in channel flow with suction and blowing

    NASA Astrophysics Data System (ADS)

    Yamamoto, Kiyoshi; Murase, Takeo; Floryan, J. M.

    1992-11-01

    Numerical simulation of laminar-turbulent transition in channel flow with spatially periodic suction/blowing from its channel walls is conducted with a spectral method based on the Fourier spectral method. Reynolds number is fixed on a subcritical value, 5,000, and the influence of both amplitude and wave number of the suction/blowing on the transition is investigated. When the amplitude is small, the transition does not occur because the suction/blowing gives only a slight effect to the basic flow and the resulted flow remains stable to all three-dimensional small disturbances. On the other hand, when the amplitude is a large value, the transition occurs in a finite time, and finally it is obtained instantaneously with a huge value of the amplitude. It is found that the suction/blowing makes the separation ridges on the wall, which may simulate a wall roughness. The transition times are obtained for the moderately large amplitudes and wave numbers, obey nearly a minus two power law dependence on the ratio of amplitude to wave number.

  15. A computer program to calculate radiating viscous stagnation streamline flow with strong blowing

    NASA Technical Reports Server (NTRS)

    Smith, G. L.; Garrett, L. B.

    1973-01-01

    A computer program (program LEE) has been developed to calculate the fully coupled solution of the radiating viscous stagnation streamline flow with strong blowing. The report describes the digital computer program, including FORTRAN IV listing, flow charts, instructions for the user, and a test case with input and output. Program LEE is available through COSMIC.

  16. Laboratory colonization of the blow flies, Chrysomya megacephala (Diptera: Calliphoridae) and Chrysomya rufifacies (Diptera: Calliphoridae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chrysomya rufifacies is a blow fly commonly found in corpses at crime scene investigations. This study was designed to develop laboratory colonization methods for Ch. rufifacies and utilize Chrysomya megacephala as its larval food source. Both fly species were collected in the wild and easily colon...

  17. Environmental factors affecting early carcass attendance by four species of blow flies (Diptera: Calliphoridae) in Texas.

    PubMed

    Mohr, Rachel M; Tomberlin, Jeffery K

    2014-05-01

    As the most common primary colonizer of carrion, adult blow flies (Diptera: Calliphoridae) play an important role in initiating arthropod-mediated breakdown of soft tissue; however, their timing is highly variable. This variability complicates the estimation of precolonization intervals or periods of insect activity by forensic entomologists. In this study, the size of the adult blow fly on swine carcasses was compared with various environmental conditions including time of day, temperature, wind speed, and light levels. Four trials were conducted: two in August and September 2008, one in January 2009, and one in February-March 2010. Of the measured variables, time of day was the only consistent factor explaining the population size of blow fly on a carcass, although precipitation and high winds affected winter-active Calliphora vicina Robineau-Desvoidy. Male flies were also collected, suggesting that carcasses may play additional roles in adult blow fly ecology beyond that of a simple oviposition site. For both sexes of flies, a strong diel pattern of behavior emerged, which could be useful in estimating precolonization intervals by considering the environmental conditions at a scene, and thus forensic entomologists may be better able to estimate the likelihood of adult activity at a carcass.

  18. Estimating the Number of Eggs in Blow Fly (Diptera: Calliphoridae) Egg Masses Using Photographic Analysis.

    PubMed

    Rosati, J Y; Pacheco, V A; Vankosky, M A; Vanlaerhoven, S L

    2015-07-01

    Little work has been done to quantify the number of eggs oviposited by blow flies (Diptera: Calliphoridae) in studies examining colonization behavior. Egg counting methods currently available are time-consuming and destructive. This study used ImageJ software and analysis of covariance to relate the volume of egg masses to the number of eggs laid by three different blow fly species: Lucilia sericata (Meigen), Phormia regina (Meigen), and Chrysomya rufifacies (Macquart). Egg mass volume, species, and the interaction of species and egg mass volume all affected the number of blow fly eggs deposited in egg masses. Both species identity and egg mass volume are important when predicting egg number, as such a single regression equation cannot be used to estimate egg number for these three species. Therefore, simple linear regression equations were determined for each species. The volume of individual eggs was incorporated into the model, yet differences between species were observed, suggesting that the orientation of the eggs oviposited by multiple conspecific females within egg masses influences egg estimates. Based on our results, we expect that imaging software can be used for other blow fly species, as well as other insect species; however, equations specific to each species must be developed. This study describes an important tool for quantifying egg deposition in a nondestructive manner, which is important in studying the colonization behavior and life history of insects of ecological and forensic importance.

  19. An experimental investigation of the effect of upper surface blowing on dynamic stall

    NASA Technical Reports Server (NTRS)

    Tso, Jin

    1993-01-01

    An experimental investigation of the effect of upper surface blowing on dynamic stall was conducted. Progress made during the period from Jun. to Dec. 1993 is summarized. Topics covered include VR-7 wing model, pulse valve, and wing/load cell junction.

  20. What Actions Can Be Taken to Increase Whistle-Blowing in the Classroom?

    ERIC Educational Resources Information Center

    Bernardi, Richard A.; Landry, Alexandra C.; Landry, Erynne E.; Buonafede, Mitchell R.; Berardi, Marissa E.

    2016-01-01

    This study surveyed undergraduate business students on various issues concerning the potential of students whistle-blowing when they observe other students cheating. Developing the courage of one's conviction in our accounting students is important to accounting educators as we are also emphasizing traits such as integrity, skepticism, and…

  1. Experimental results of the control of a vortical flow by tangential blowing

    NASA Technical Reports Server (NTRS)

    Wood, N. J.; Roberts, L.

    1986-01-01

    The results of a wind tunnel test to investigate the controlling effects of tangential, leading edge blowing on the vortical flow over a delta wing are given. Blowing is used to directly control the crossflow separation points at the rounded leading edge and hence, the trajectory of the feeding sheet and the location of the vortex. Experiments were conducted for both co-flowing and counter-flowing configurations over a range of angles of attack from 0 to 90 degrees. Results in the form of pressure distributions, overall force coefficients and flow mappings were obtained. The emphasis is on data presentation rather than detailed analysis. The initial results indicate that the co-flowing configuration was capable of extending the regime of stable, controlled vortical flow over the upper surface by approximately 30 degrees angle of attack for modest blowing requirements. Increases in maximum normal force coefficient of approximately 30% were achieved and significant rolling moments produced at angles of attack from 30 to 60 degrees. The counter-flowing configuration indicated only minor lift augmentation with the exception of an isolated occurrence at 20 degrees angle of attack. At that condition, with very weak blowing, a lift augmentation of approximately 20 was measured.

  2. Separation of organic azeotropic mixtures by pervaporation

    SciTech Connect

    Baker, R.W.

    1991-12-01

    Distillation is a commonly used separation technique in the petroleum refining and chemical processing industries. However, there are a number of potential separations involving azetropic and close-boiling organic mixtures that cannot be separated efficiently by distillation. Pervaporation is a membrane-based process that uses selective permeation through membranes to separate liquid mixtures. Because the separation process is not affected by the relative volatility of the mixture components being separated, pervaporation can be used to separate azetropes and close-boiling mixtures. Our results showed that pervaporation membranes can be used to separate azeotropic mixtures efficiently, a result that is not achievable with simple distillation. The membranes were 5--10 times more permeable to one of the components of the mixture, concentrating it in the permeate stream. For example, the membrane was 10 times more permeable to ethanol than methyl ethyl ketone, producing 60% ethanol permeate from an azeotropic mixture of ethanol and methyl ethyl ketone containing 18% ethanol. For the ethyl acetate/water mixture, the membranes showed a very high selectivity to water (> 300) and the permeate was 50--100 times enriched in water relative to the feed. The membranes had permeate fluxes on the order of 0.1--1 kg/m{sup 2}{center dot}h in the operating range of 55--70{degrees}C. Higher fluxes were obtained by increasing the operating temperature.

  3. The Effects of Blowing Over Various Trailing-edge Flaps on an NACA 0006 Airfoil Section, Comparisons with Various Types of Flaps on other Airfoil Sections, and an Analysis of Flow and Power Relationships for Blowing Systems

    NASA Technical Reports Server (NTRS)

    Dods, J. B., Jr.; Watson, E. C.

    1976-01-01

    The results are presented of a two-dimensional investigation conducted to determine the effect of blowing over various types of trailing-edge flaps on a wing having the NACA 0006 airfoil section and a drooped-nose flap. The position and profile of the trailing-edge flap, the nozzle height, and the location of the flap with respect to the nozzle were found to be important variables. Data from many investigations were used to make an evaluation of the effects of blowing on lift. An analysis was made of flow and power relationships for blowing systems.

  4. Symmetric normal mixtures

    NASA Technical Reports Server (NTRS)

    Turmon, Michael

    2004-01-01

    We consider mixture density estimation under the symmetry constraint x = Az for an orthogonal matrix A. This distributional constraint implies a corresponding constraint on the mixture parameters. Focusing on the gaussian case, we derive an expectation-maximization (EM) algorithm to enforce the constraint and show results for modeling of image feature vectors.

  5. Experiments in Aircraft Roll-Yaw Control using Forebody Tangential Blowing

    NASA Technical Reports Server (NTRS)

    Pedreiro, Nelson

    1997-01-01

    Advantages of flight at high angles of attack include increased maneuverability and lift capabilities. These are beneficial not only for fighter aircraft, but also for future supersonic and hypersonic transport aircraft during take-off and landing. At high angles of attack the aerodynamics of the vehicle are dominated by separation, vortex shedding and possibly vortex breakdown. These phenomena severely compromise the effectiveness of conventional control surfaces. As a result, controlled flight at high angles of attack is not feasible for current aircraft configurations. Alternate means to augment the control of the vehicle at these flight regimes are therefore necessary. The present work investigates the augmentation of an aircraft flight control system by the injection of a thin sheet of air tangentially to the forebody of the vehicle. This method, known as Forebody Tangential Blowing (FTB), has been proposed as an effective means of increasing the controllability of aircraft at high angles of attack. The idea is based on the fact that a small amount of air is sufficient to change the separation lines on the forebody. As a consequence, the strength and position of the vortices are altered causing a change on the aerodynamic loads. Although a very effective actuator, forebody tangential blowing is also highly non-linear which makes its use for aircraft control very difficult. In this work, the feasibility of using FTB to control the roll-yaw motion of a wind tunnel model was demonstrated both through simulations and experimentally. The wind tunnel model used in the experiments consists of a wing-body configuration incorporating a delta wing with 70-degree sweep angle and a cone-cylinder fuselage. The model is equipped with forebody slots through which blowing is applied. There are no movable control surfaces, therefore blowing is the only form of actuation. Experiments were conducted at a nominal angle of attack of 45 degrees. A unique apparatus that constrains

  6. Blow-up of solutions of non-linear equations of Kadomtsev-Petviashvili and Zakharov-Kuznetsov types

    NASA Astrophysics Data System (ADS)

    Korpusov, M. O.; Sveshnikov, A. G.; Yushkov, E. V.

    2014-06-01

    The Kadomtsev-Petviashvili equation and Zakharov-Kuznetsov equation are important in physical applications. We obtain sufficient conditions for finite-time blow-up of solutions of these equations in bounded and unbounded domains. We describe how the initial data influence the blow-up time. To do this, we use the non-linear capacity method suggested by Pokhozhaev and Mitidieri and combine it with the method of test functions, which was developed in joint papers with Galaktionov. Note that our results are the first blow-up results for many equations in this class.

  7. Perception of trigeminal mixtures.

    PubMed

    Filiou, Renée-Pier; Lepore, Franco; Bryant, Bruce; Lundström, Johan N; Frasnelli, Johannes

    2015-01-01

    The trigeminal system is a chemical sense allowing for the perception of chemosensory information in our environment. However, contrary to smell and taste, we lack a thorough understanding of the trigeminal processing of mixtures. We, therefore, investigated trigeminal perception using mixtures of 3 relatively receptor-specific agonists together with one control odor in different proportions to determine basic perceptual dimensions of trigeminal perception. We found that 4 main dimensions were linked to trigeminal perception: sensations of intensity, warmth, coldness, and pain. We subsequently investigated perception of binary mixtures of trigeminal stimuli by means of these 4 perceptual dimensions using different concentrations of a cooling stimulus (eucalyptol) mixed with a stimulus that evokes warmth perception (cinnamaldehyde). To determine if sensory interactions are mainly of central or peripheral origin, we presented stimuli in a physical "mixture" or as a "combination" presented separately to individual nostrils. Results showed that mixtures generally yielded higher ratings than combinations on the trigeminal dimensions "intensity," "warm," and "painful," whereas combinations yielded higher ratings than mixtures on the trigeminal dimension "cold." These results suggest dimension-specific interactions in the perception of trigeminal mixtures, which may be explained by particular interactions that may take place on peripheral or central levels. PMID:25500807

  8. Perception of trigeminal mixtures.

    PubMed

    Filiou, Renée-Pier; Lepore, Franco; Bryant, Bruce; Lundström, Johan N; Frasnelli, Johannes

    2015-01-01

    The trigeminal system is a chemical sense allowing for the perception of chemosensory information in our environment. However, contrary to smell and taste, we lack a thorough understanding of the trigeminal processing of mixtures. We, therefore, investigated trigeminal perception using mixtures of 3 relatively receptor-specific agonists together with one control odor in different proportions to determine basic perceptual dimensions of trigeminal perception. We found that 4 main dimensions were linked to trigeminal perception: sensations of intensity, warmth, coldness, and pain. We subsequently investigated perception of binary mixtures of trigeminal stimuli by means of these 4 perceptual dimensions using different concentrations of a cooling stimulus (eucalyptol) mixed with a stimulus that evokes warmth perception (cinnamaldehyde). To determine if sensory interactions are mainly of central or peripheral origin, we presented stimuli in a physical "mixture" or as a "combination" presented separately to individual nostrils. Results showed that mixtures generally yielded higher ratings than combinations on the trigeminal dimensions "intensity," "warm," and "painful," whereas combinations yielded higher ratings than mixtures on the trigeminal dimension "cold." These results suggest dimension-specific interactions in the perception of trigeminal mixtures, which may be explained by particular interactions that may take place on peripheral or central levels.

  9. Single-stage evaluation of highly-loaded high-Mach-number compressor stages 5. Data and performance of baseline, corner-blow wall suction and combined corner blow wall suction stator

    NASA Technical Reports Server (NTRS)

    Nikkanen, J. P.; Brooky, J. P.

    1972-01-01

    A single-stage compressor with a rotor tip speed of 1600 ft/sec and a 0.5 hub tip ratio was used to investigate the effects of several stator endwall treatment methods on stage range and performance. These endwall treatment methods consisted of stator corner-blow, annular wall suction upstream of stator leading edge, and combined corner-blow and annular wall suction. The overall stage performance with corner blow was essentially the same as the baseline performance. The performance for the annular wall suction and the combined corner-blow and wall suction showed a reduction in peak efficiency of 2.5 percentage points compared to the baseline data.

  10. SEPARATION OF FLUID MIXTURES

    DOEpatents

    Lipscomb, R.; Craig, A.; Labrow, S.; Dunn, J.F.

    1958-10-28

    An apparatus is presented for separating gaseous mixtures by selectively freezing a constituent of the mixture and subsequently separating the frozen gas. The gas mixture is passed through a cylinder fltted with a cooling jacket, causing one gas to freeze on the walls of the cylinder. A set of scraper blades are provided in the interior of the cyllnder, and as the blades oscillate, the frozen gas is scraped to the bottom of the cylinder. Means are provided for the frozen material to pass into a heating chamber where it is vaporized and the product gas collected.

  11. Conjugate Heat Transfer Computation for Evaluation of Single-Blow Method for Compact Fin-Tube Heat Exchangers

    NASA Astrophysics Data System (ADS)

    Song, Gil-Dal; Nishino, Koichi

    Computations have been carried out to evaluate heat transfer coefficients given by the single-blow method that is characterized by a transient and conjugate heat transfer problem between the fluid and the solid. Both heat conduction and convection equations are solved numerically to obtain the transient fluid and fin temperature distributions. Finite volume solutions indicate that the fin temperature distribution of the single-blow method varies with time and position and that the fluid temperature distribution of the single-blow method is close to that observed in the steady-state computation specified with the constant wall temperature condition. It is found that the local heat transfer coefficient resulting from the single-blow method is almost identical to that from the steady-state constant wall temperature computation and is nearly time-independent.

  12. [Diagnostic image (113). A neonate blowing bubbles. Esophageal atresia with tracheoesophageal fistula, Hirschsprung disease and suspected Down's syndrome].

    PubMed

    Postema, R R; Meradji, M; Langemeijer, R A Th M

    2002-11-01

    In a male neonate 'blowing bubbles', three diagnoses were seen on a combined thoracic and abdominal X-ray: esophageal atresia with tracheoesophageal fistula, Hirschsprung's disease, and suspected Down's syndrome (because of the presence of II pairs of ribs).

  13. Importance of back blow maneuvers in a 6 month old patient with sudden upper airway obstruction.

    PubMed

    Gencpinar, Pinar; Duman, Murat

    2015-12-01

    Foreign body aspiration in children under four years old is one of the most frequently observed reasons for accident related deaths. It is more common in this age group due to inadequate swallowing functions and exploration of objects with the mouth. The most frequently encountered foreign bodies are food and toy parts. Life threatening complete laryngeal obstruction is rarely observed. Dyspnea, hypersalivation, cough and cyanosis can be seen. The basic and life-saving treatment approach is complete removal of foreign body maneuvers in the sudden onset of total obstruction. Here we report a six-month old male, who ingested a foreign body and was treated with back blow maneuvers successfully. In this case we emphasized the importance of back blow maneuvers. PMID:27239623

  14. Fine Structure of the Eggshell of the Blow Fly, Lucilia cuprina

    PubMed Central

    Sukontason, Kabkaew L.; Bunchu, Nophawan; Chaiwong, Tarinee; Kuntalue, Budsabong; Sukontason, Kom

    2007-01-01

    The fine structure of the eggshell of blow fly, Lucilia cuprina (Wiedemann) (Diptera: Calliphoridae), was examined using scanning and transmission electron microscopy. Eggs, 1.09±0.07 mm in length and 0.25±0.05 mm in width, bore a relatively wide plastron that extending along almost the entire length. The polygonal pattern of chorionic sculpture was indistinct. The ultrathin section indicated a multi-layered eggshell having an exochorion, outer endochorion, pillars, an inner endochorion, innermost chorionic layer, and a wax layer. This study provides new information about the fine morphology of blow flies eggs. A key to differentiate the eggs of forensically important flies in Thailand is given. PMID:20334590

  15. Investigation of trailing-edge-flap, spanwise-blowing concepts on an advanced fighter configuration

    NASA Technical Reports Server (NTRS)

    Paulson, J. W., Jr.; Quinto, P. F.; Banks, D. W.

    1984-01-01

    The aerodynamic effects of spanwise blowing on the trailing edge flap of an advanced fighter aircraft configuration were determined in the 4 by 7 Meter Tunnel. A series of tests were conducted with variations in spanwise-blowing vector angle, nozzle exit area, nozzle location, thrust coefficient, and flap deflection in order to determine a superior configuration for both an underwing cascade concept and an overwing port concept. This screening phase of the testing was conducted at a nominal approach angle of attack from 12 deg to 16 deg; and then the superior configurations were tested over a more complete angle of attack range from 0 deg to 20 deg at tunnel free stream dynamic pressures from 20 to 40 lbf/sq ft at thrust coefficients from 0 to 2.

  16. Experimental Evaluation of the Penalty Associated With Micro-Blowing for Reducing Skin Friction

    NASA Technical Reports Server (NTRS)

    Hwang, Danny P.; Biesiadny, Tom J.

    1997-01-01

    A micro-blowing technique (MBT) experiment was conducted in the Advanced Nozzle and Engine Components Test Facility at the NASA Lewis Research Center. The objectives of the test were to evaluate the pressure-drag penalty associated with the MBT and to provide additional information about the porous plates used for micro-blowing. The results showed that 1 of 12 plates tested could reduce the total drag (skin-friction drag plus pressure drag) below a solid flat plate value. The results of this experiment and prior data showed that a total drag reduction below a solid flat plate value was possible. More tests are needed to find an optimal MBT skin and to find a technique to reduce pressure drag.

  17. Identities for Generalized Appell Functions and the Blow-up Formula

    NASA Astrophysics Data System (ADS)

    Bringmann, Kathrin; Manschot, Jan; Rolen, Larry

    2016-10-01

    In this paper, we prove identities for a class of generalized Appell functions which are based on the {A_2} root lattice. The identities are reminiscent of periodicity relations for the classical Appell function and are proven using only analytical properties of the functions. Moreover, they are a consequence of the blow-up formula for generating functions of invariants of moduli spaces of semi-stable sheaves of rank 3 on rational surfaces. Our proof confirms that in the latter context, different routes to compute the generating function (using the blow-up formula and wall-crossing) do arrive at identical q-series. The proof also gives a clear procedure on how to prove analogous identities for generalized Appell functions appearing in generating functions for sheaves with rank {r>3}.

  18. Simulation on the Effect of Bottle Wall Thickness Distribution using Blow Moulding Technique

    NASA Astrophysics Data System (ADS)

    Suraya, S.; Azman, M. D.; Fatchurrohman, N.; Jaafar, A. A.; Yusoff, A. R.

    2016-02-01

    The aims of this study are to assess the deformation behavior of a polymeric material during a blow moulding process. Transient computations of two dimensional model of a PP bottle were performed using ANSYS Polyflow computer code to predict the wall thickness distribution at four different parison's diameter; 8mm, 10mm, 18mm, and 20mm. Effects on the final wall thickness diameter and time step are studied. The simulated data shows that the inflation performance degrades with increasing parison diameter. It is concluded that the blow moulding process using 10mm parison successfully meet the product processing requirements. Factors that contribute to the variation in deformation behaviour of the plastic during the manufacturing process are discussed.

  19. Analysis of a fixed-pitch X-wing rotor employing lower surface blowing

    NASA Technical Reports Server (NTRS)

    Schwartz, Alan W.; Rogers, Ernest O.

    1987-01-01

    Lower surface blowing (LSB) is investigated as an alternative to the variable blade pitch requirement for the X-wing Circulation Control (CC) rotor concept. Addition trailing edge blowing slots on the lower surfaces of CC airfoils provide a bidirectional lift capability that effectively doubles the control range. The operational requirements of this rotor system are detailed and compared to the projected performance attributes of LSB airfoils. Analysis shows that, aerodynamically, LSB supplies a fixed pitch rotor system with the equivalent lift efficiency and rotor control of present CC rotor designs that employ variable blade pitch. Aerodynamic demands of bidirectional lift production are predicted to be within the capabilities of current CC airfoil design methodology. Emphasis in this analysis is given to the high speed rotary wing flight regime unique to stoppable rotor aircraft. The impact of a fixed pitch restriction in hover and low speed flight is briefly discussed.

  20. An electrostatic charge measurement of blowing snow particles focusing on collision frequency to the snow surface

    NASA Astrophysics Data System (ADS)

    Omiya, S.; Sato, A.

    2010-12-01

    Blowing snow particles are known to have an electrostatic charge. This charge may be a contributing factor in the formation of snow drifts and snow cornices and changing of the trajectory of blowing snow particles. These formations and phenomena can cause natural disaster such as an avalanche and a visibility deterioration, and obstruct transportation during winter season. Therefore, charging phenomenon of the blowing snow particles is an important issue in terms of not only precise understanding of the particle motion but disaster prevention. The primary factor of charge accumulation to the blowing snow particles is thought to be due to “saltation” of them. The “saltation” is one of movement forms of blowing snow: when the snow particles are transported by the wind, they repeat frictional collisions with the snow surface. In previous studies, charge-to-mass ratios measured in the field were approximately -50 to -10 μC/kg, and in the wind tunnel were approximately -0.8 to -0.1 μC/kg. While there were qualitatively consistent in sign, negative, there were huge gaps quantitatively between them. One reason of those gaps is speculated to be due to differences in fetch. In other words, the difference of the collision frequency of snow particles to the snow surface has caused the gaps. But it is merely a suggestion and that has not been confirmed. The purpose of this experiment is to measure the charge of blowing snow particles focusing on the collision frequency and clarify the relationship between them. Experiments were carried out in the cryogenic wind tunnel of Snow and Ice Research Center (NIED, JAPAN). A Faraday cage and an electrometer were used to measure the charge of snow particles. These experiments were conducted over the hard snow surface condition to prevent the erosion of the snow surface and the generation of new snow particles from the surface. The collision frequency of particle was controlled by changing the wind velocity (4.5 to 7 m/s) under

  1. Gene expression during blow fly development: improving the precision of age estimates in forensic entomology.

    PubMed

    Tarone, Aaron M; Foran, David R

    2011-01-01

    Forensic entomologists use size and developmental stage to estimate blow fly age, and from those, a postmortem interval. Since such estimates are generally accurate but often lack precision, particularly in the older developmental stages, alternative aging methods would be advantageous. Presented here is a means of incorporating developmentally regulated gene expression levels into traditional stage and size data, with a goal of more precisely estimating developmental age of immature Lucilia sericata. Generalized additive models of development showed improved statistical support compared to models that did not include gene expression data, resulting in an increase in estimate precision, especially for postfeeding third instars and pupae. The models were then used to make blind estimates of development for 86 immature L. sericata raised on rat carcasses. Overall, inclusion of gene expression data resulted in increased precision in aging blow flies.

  2. [The bubble-blowing neonate: a red flag for oesophageal atresia].

    PubMed

    Zwaan, Esther; Meij-de Vries, Annebeth; van Deutekom, Arend W; van der Steeg, Alida F W; Sleeboom, Christien; Heij, Hugo A

    2013-01-01

    When a newborn develops feeding difficulties, is blowing bubbles or has excessive saliva, it is important to consider the diagnosis of oesophageal atresia. Prenatal detection of oesophageal atresia is difficult. Postnatal bubble blowing, resulting from the inability to swallow excessive oropharyngeal secretions, is pathognomonic. These symptoms should trigger the midwife or physician to consider this diagnosis. We present three cases to illustrate the difficulties of early recognition and the consequences of a late detection of this condition. The first and third cases show that a delayed diagnosis of oesophageal atresia can lead to dangerous situations. Our second case illustrates that not every poorly drinking neonate has oesophageal atresia, and that this diagnosis may be rejected if the physician is able to pass a nasogastric tube. In every neonate who is unable to drink, we advise attempting to pass a nasogastric tube and taking a chest x-ray to distinguish between oesophageal atresia and other causes of feeding problems.

  3. Experimental Study of the Influence of Gassing Material on Blow Open Force and Arc Motion

    NASA Astrophysics Data System (ADS)

    Li, Xingwen; Chen, Degui; Liu, Hongwu; Shi, Zongqian; Wang, Jianhua

    2007-12-01

    The study of arc behavior is important to understand the dynamic phenomena concerning the interruption process in a variety of switching devices. This paper is devoted to investigate the influence of gassing material on blow open force and arc motion. To one double-breaker model, measuring the arc current, voltage and force acting on the moving conductor, the characteristics of the ratio of the emerging blow open force over arc power FB/(ui) could be obtained. With the help of a 2-D optical fiber measurement system, to one arc chamber model, arc motion behavior was measured, too. It is demonstrated that, with the action of gassing material, FB/(ui) will increase 2.5 times, and the arc will enter the splitter plates much easier.

  4. Identities for Generalized Appell Functions and the Blow-up Formula

    NASA Astrophysics Data System (ADS)

    Bringmann, Kathrin; Manschot, Jan; Rolen, Larry

    2016-07-01

    In this paper, we prove identities for a class of generalized Appell functions which are based on the {A_2} root lattice. The identities are reminiscent of periodicity relations for the classical Appell function and are proven using only analytical properties of the functions. Moreover, they are a consequence of the blow-up formula for generating functions of invariants of moduli spaces of semi-stable sheaves of rank 3 on rational surfaces. Our proof confirms that in the latter context, different routes to compute the generating function (using the blow-up formula and wall-crossing) do arrive at identical q-series. The proof also gives a clear procedure on how to prove analogous identities for generalized Appell functions appearing in generating functions for sheaves with rank {r>3}.

  5. Effect of a simulated engine jet blowing above an arrow wing at Mach 2.0

    NASA Technical Reports Server (NTRS)

    Shrout, B. L.; Hayes, C.

    1977-01-01

    The effects of a gas jet simulating a turbojet engine exhaust blowing above a cambered and twisted arrow wing were investigated. Tests were conducted in the Langley 4-foot supersonic pressure tunnel at a Mach number of 2.0. Nozzle pressure ratios from 1 to 64 were tested with both helium and air used as jet gases. The tests were conducted at angles of attack from -2 deg to 8 deg at a Reynolds number of 9,840,000 per meter. Only the forces and moments on the wing were measured. Results of the investigation indicated that the jet blowing over the wing caused reductions in maximum lift-drag ratio of about 4 percent for helium and 6 percent for air at their respective design nozzle pressure ratios, relative to jet-off data. Moderate changes in the longitudinal, vertical, or angular positions of the jet relative to the wing had little effect on the wing aerodynamic characteristics.

  6. A Comparison Study of the Oxygen-Rich Side Blow Furnace and the Oxygen-Rich Bottom Blow Furnace for Liquid High Lead Slag Reduction

    NASA Astrophysics Data System (ADS)

    Chen, Lin; Hao, Zhandong; Yang, Tianzu; Liu, Weifeng; Zhang, Duchao; Zhang, Li; Bin, Shu; Bin, Wanda

    2015-05-01

    This work investigates the characteristics of the oxygen-rich side blow furnace (OSBF) and the oxygen-rich bottom blow furnace (OBBF) as the reductive smelting reactor for molten high lead slag. The slags were collected from different sampling points of these furnaces during a regular high lead slag reduction process and analyzed. It is disclosed that lead content of the melt in the OSBF shows dramatic fluctuations, while melt from different sampling points of the furnace behave similarly, exhibiting the characteristics of batch reactor. An obvious axial lead content gradient is detected in the OBBF, showing the characteristics of a plug flow reactor. The industrial performances of these furnaces are also compared. The results indicate that 1.38% higher lead recovery can be achieved by using the OSBF instead of the OBBF. Unit energy consumptions of the OBBF-OSBF and OBBF-OBBF processes can be reduced to 230 kgce/ t crude lead, which is 70 kgce/ t crude lead less than that of the tradition Shuikoushan (SKS) process.

  7. Assessing exposures to inhaled complex mixtures.

    PubMed Central

    Leaderer, B P; Lioy, P J; Spengler, J D

    1993-01-01

    In the course of daily activities, individuals spend varying amounts of time in different spaces where they are exposed to a complex mixture of gas, vapor, and particulate contaminants. The term complex is used in this paper to refer to binary mixtures as well as truly complex mixtures of three or more constituents. The diversity of the environments where pollution may occur, the number of pollutants that may be present, and the nature of the activity in the environment combine to pose a challenge to investigators of the health effects of air pollutants. This article discusses several methods of measuring or assessing exposure to complex mixture air contaminants that include time-activity assessments, personal monitoring, biomarkers of exposure, and microenvironmental models that can be employed singly or in combination in a protocol for exposure assessment. The use of nested designs, involving more intensive data collection from samples or subjects, is also considered. PMID:8206025

  8. The effect of blow flies (Diptera: Calliphoridae) on the size and weight of mangos (Mangifera indica L.)

    PubMed Central

    Naqqash, Muhammad Nadir; Saeed, Qamar; Ghouri, Fozia

    2016-01-01

    Background: Pollination has a great effect on the yield of fruit trees. Blow flies are considered as an effective pollinator compared to hand pollination in fruit orchards. Therefore, this study was designed to evaluate the effect of different pollination methods in mango orchards. Methodology: The impact of pollination on quantity and quality of mango yield by blow flies was estimated by using three treatments, i.e., open pollinated trees, trees were covered by a net in the presence of blow flies for pollination, and trees were covered with a net but without insects. Results: The maximum number of flowers was recorded in irregular types of inflorescence, i.e., 434.80 flowers/inflorescence. Fruit setting (bud) was higher in open pollinated mango trees (i.e. 37.00/inflorescence) than enclosed pollination by blow flies (i.e. 22.34/inflorescence). The size of the mango fruit was the highest (5.06 mm) in open pollinated tree than those pollinated by blow flies (3.93 mm) and followed by without any pollinator (3.18 mm) at marble stage. We found that the maximum weight of mango fruit (201.19 g) was in open pollinated trees. Discussion: The results demonstrated that blow flies can be used as effective mango pollinators along with other flies and bees. The blow flies have shown a positive impact on the quality and quantity of mango. This study will be helpful in future and also applicable at farm level to use blow flies as pollinators that are cheap and easy to rear. PMID:27441107

  9. Distributed Blowing and Suction for the Purpose of Streak Control in a Boundary Layer Subjected to a Favorable Pressure Gradient

    NASA Technical Reports Server (NTRS)

    Forgoston, Eric; Tumin, Anatoli; Ashpis, David E.

    2005-01-01

    An analysis of the optimal control by blowing and suction in order to generate stream- wise velocity streaks is presented. The problem is examined using an iterative process that employs the Parabolized Stability Equations for an incompressible uid along with its adjoint equations. In particular, distributions of blowing and suction are computed for both the normal and tangential velocity perturbations for various choices of parameters.

  10. Blow-up rates for higher-order semilinear parabolic equations and systems and some Fujita-type theorems

    NASA Astrophysics Data System (ADS)

    Pan, Hongjing; Xing, Ruixiang

    2008-03-01

    In this paper, we derive blow-up rates for higher-order semilinear parabolic equations and systems. Our proof is by contradiction and uses a scaling argument. This procedure reduces the problems of blow-up rate to Fujita-type theorems. In addition, we also give some new Fujita-type theorems for higher-order semilinear parabolic equations and systems with the time variable on . These results are not restricted to positive solutions.

  11. Effect of jenny milk addition on the inhibition of late blowing in semihard cheese.

    PubMed

    Cosentino, C; Paolino, R; Valentini, V; Musto, M; Ricciardi, A; Adduci, F; D'Adamo, C; Pecora, G; Freschi, P

    2015-08-01

    The occurrence of late blowing defects in cheese produces negative effects on the quality and commercial value of the product. In this work, we verified whether the addition of raw jenny milk to bulk cow milk reduced the late blowing defects in semihard cheeses. During cheesemaking, different aliquots of jenny milk were poured into 2 groups of 4 vats, each containing a fixed amount of cow milk. A group of cheeses was created by deliberately contaminating the 4 vats with approximately 3 log10 cfu/mL milk of Clostridium tyrobutyricum CLST01. The other 4 vats, which were not contaminated, were used for a second group of cheeses. After 120 d of ripening, some physical, chemical, and microbiological parameters were evaluated on the obtained semihard cheeses. Differences in sensory properties among cheeses belonging to the uncontaminated group were evaluated by 80 regular consumers of cheese. Our results showed that the increasing addition of jenny milk to cow milk led to a reduction of pH and total bacterial count in both cheese groups, as well as C. tyrobutyricum spores that either grew naturally or artificially inoculated. We observed a progressive reduction of the occurrence of late blowing defects in cheese as consequence of the increasing addition of jenny milk during cheese making. Moreover, the addition of jenny milk did not affect the acceptability of the product, as consumers found no difference among cheeses concerning sensorial aspects. In conclusion, the important antimicrobial activity of lysozyme contained in jenny milk has been confirmed in the current research. It is recommend for use as a possible and viable alternative to egg lysozyme for controlling late blowing defects in cheese.

  12. The exact asymptotic behavior of boundary blow-up solutions to infinity Laplacian equations

    NASA Astrophysics Data System (ADS)

    Wan, Haitao

    2016-08-01

    In this paper, we study the asymptotic behavior of viscosity solutions to boundary blow-up elliptic problem {Δ_{∞}u=b(x)f(u), xinΩ, u|_{partialΩ}=+∞,} where {Ω} is a bounded domain with C 2-boundary in {{R}N}, {bin C(bar{Ω})} is positive in {Ω}, which may be vanishing on the boundary, {fin C1([0, ∞))} is regularly varying or is rapidly varying at infinity.

  13. Blow-up of the smooth solution to quantum hydrodynamic models in Rd

    NASA Astrophysics Data System (ADS)

    Guo, Boling; Wang, Guangwu

    2016-10-01

    In this paper we firstly investigate the local-in-time existence of smooth solution for the quantum hydrodynamic models (QHD) in Rd. Then we prove that any smooth solution of the QHD model which satisfies suitable conditions will blow up in finite time. The model can be derived from nonlinear Schrödinger equation by a Madelung transformation. The main idea is based on the construction of approximate solution and energy inequality.

  14. Reduction of profile drag by blowing out through peg holes in areas of streamline separation bubbles

    NASA Technical Reports Server (NTRS)

    Horstmann, K. H.; Quast, A.

    1981-01-01

    Streamline separation bubbles on aircraft profiles and fuselages were investigated. The additional drag was examined in relation to increased angle of incidence and unusually high wall sheer stress. A reduction of the separation bubble and a decrease in drag is obtained with pneumatic turbulators that blow ram air out of 0.6mm pilot tubes at a distance of 16 mm. The pneumatic models are implemented at various positions and are found to be effective after the position of separation.

  15. Hypersonic Boundary Layer Measurements with Variable Blowing Rates Using Molecular Tagging Velocimetry

    NASA Technical Reports Server (NTRS)

    Bathel, Brett F.; Danehy, Paul M.; Johansen, Craig T.; Jones, Stephen B.; Goyne, Christopher P.

    2012-01-01

    Measurements of mean and instantaneous streamwise velocity profiles in a hypersonic boundary layer with variable rates of mass injection (blowing) of nitrogen dioxide (NO2) were obtained over a 10-degree half-angle wedge model. The NO2 was seeded into the flow from a slot located 29.4 mm downstream of the sharp leading edge. The top surface of the wedge was oriented at a 20 degree angle in the Mach 10 flow, yielding an edge Mach number of approximately 4.2. The streamwise velocity profiles and streamwise fluctuating velocity component profiles were obtained using a three-laser NO2->NO photolysis molecular tagging velocimetry method. Observed trends in the mean streamwise velocity profiles and profiles of the fluctuating component of streamwise velocity as functions of the blowing rate are described. An effort is made to distinguish between the effect of blowing rate and wall temperature on the measured profiles. An analysis of the mean velocity profiles for a constant blowing rate is presented to determine the uncertainty in the measurement for different probe laser delay settings. Measurements of streamwise velocity were made to within approximately 120 gm of the model surface. The streamwise spatial resolution in this experiment ranged from 0.6 mm to 2.6 mm. An improvement in the spatial precision of the measurement technique has been made, with spatial uncertainties reduced by about a factor of 2 compared to previous measurements. For the quiescent flow calibration measurements presented, uncertainties as low as 2 m/s are obtained at 95% confidence for long delay times (25 gs). For the velocity measurements obtained with the wind tunnel operating, average single-shot uncertainties of less than 44 m/s are obtained at 95% confidence with a probe laser delay setting of 1 gs. The measurements were performed in the 31-inch Mach 10 Air Tunnel at the NASA Langley Research Center.

  16. Experimental study on sulfur removal from ladle furnace refining slag in hot state by blowing air

    NASA Astrophysics Data System (ADS)

    Zhao, Li-hua; Lin, Lu; Wu, Qi-fan

    2016-01-01

    In view of the present problem of sulfur enrichment in the metallurgical recycling process of ladle furnace (LF) refining slag, a simple and efficient method of removing sulfur from this slag was proposed. The proposed method is compatible with current steelmaking processes. Sulfur removal from LF refining slag for SPHC steel (manufactured at a certain steel plant in China) by blowing air in the hot state was studied by using hot-state experiments in a laboratory. The FactSage software, a carbon/sulfur analyzer, and scanning electron microscopy in conjunction with energy-dispersive X-ray spectroscopy were used to test and analyze the sulfur removal effect and to investigate factors influencing sulfur removal rate. The results show that sulfur ions in LF refining slag can be oxidized into SO2 by O2 at high temperature by blowing air into molten slag; SO2 production was observed to reach a maximum with a small amount of blown O2 when the temperature exceeded 1350°C. At 1370°C and 1400°C, experimental LF refining slag is in the liquid state and exhibits good fluidity; under these conditions, the sulfur removal effect by blowing air is greater than 90wt% after 60 min. High temperature and large air flow rate are beneficial for removing sulfur from LF refining slag; compared with air flow rate, temperature has a greater strongly influences on the sulfur removal.

  17. Blow-up problems for the heat equation with a local nonlinear Neumann boundary condition

    NASA Astrophysics Data System (ADS)

    Yang, Xin; Zhou, Zhengfang

    2016-09-01

    This paper estimates the blow-up time for the heat equation ut = Δu with a local nonlinear Neumann boundary condition: The normal derivative ∂ u / ∂ n =uq on Γ1, one piece of the boundary, while on the rest part of the boundary, ∂ u / ∂ n = 0. The motivation of the study is the partial damage to the insulation on the surface of space shuttles caused by high speed flying subjects. We show the finite time blow-up of the solution and estimate both upper and lower bounds of the blow-up time in terms of the area of Γ1. In many other work, they need the convexity of the domain Ω and only consider the problem with Γ1 = ∂ Ω. In this paper, we remove the convexity condition and only require ∂Ω to be C2. In addition, we deal with the local nonlinearity, namely Γ1 can be just part of ∂Ω.

  18. Investigating the potential of fluorescent fingerprint powders as a marker for blow fly larvae (Diptera: calliphoridae).

    PubMed

    Rosati, Jennifer Y; Robinson, Scott D; Devine, Richard

    2015-05-01

    Four fluorescent fingerprint powders (RedWop(™) , GreenWop(™) , Basic Yellow(™) , and Yellow Powder(™) ) were evaluated as a marker for blow fly larvae. Administration methods included ingestion (high vs. low concentration) or topical. Ingestion of high concentrations of Basic Yellow(™) and RedWop(™) caused higher larval mortality. Basic Yellow(™) delayed development and adult emergence while RedWop(™) and Yellow Powder(™) had a significant effect on particular stages of development, however, emergence time was not altered. Optimal administration is through ingestion at low concentration levels (<10%) or topically, with GreenWop(™) demonstrating minimal adverse effects. Optimum wavelength for discrimination between powders was 450 nm. This research can aid in investigative training to increase visibility of larval and pupal blow flies. It can also be used in entomological studies to differentiate between larval blow flies (or other dipteran) species or individuals to further understand complex interactions and behavior during larval development.

  19. Broadband Noise Reduction of a Low-Speed Fan Noise Using Trailing Edge Blowing

    NASA Technical Reports Server (NTRS)

    Sutliff, Daniel L.

    2005-01-01

    An experimental proof-of-concept test was conducted to demonstrate reduction of rotor-stator interaction noise through the use of rotor-trailing edge blowing. The velocity deficit from the viscous wake of the rotor blades was reduced by injecting air into the wake from a continuous trailing edge slot. Hollow blades with interior guide vanes create flow channels through which externally supplied air flows from the blade root to the trailing edge. A previous paper documented the substantial tonal reductions of this Trailing Edge Rotor Blowing (TERB) fan. This report documents the broadband characteristics of TERB. The Active Noise Control Fan (ANCF), located at the NASA Glenn Research Center, was used as the proof-of-concept test bed. Two-component hotwire data behind the rotor, unsteady surface pressures on the stator vane, and farfield directivity acoustic data were acquired at blowing rates of 1.1, 1.5, and 1.8 percent of the total fan mass flow. The results indicate a substantial reduction in the rotor wake turbulent velocity and in the stator vane unsteady surface pressures. Based on the physics of the noise generation, these indirect measurements indicate the prospect of broadband noise reduction. However, since the broadband noise generated by the ANCF is rotor-dominated, any change in the rotor-stator interaction broadband noise levels is barely distinguishable in the farfield measurements.

  20. Augmentation of fighter-aircraft performance by spanwise blowing over the wing leading edge

    NASA Technical Reports Server (NTRS)

    Seginer, A.; Salomon, M.

    1983-01-01

    Spanwise blowing over the wing and canard of a 1:35 model of a close-coupled-canard fighter-airplane configuration (similar to the Kfir-C2) was investigated experimentally in low-speed flow. Tests were conducted at airspeeds of 30 m/sec (Reynolds number of 1.8 x 10 to the 5th power based on mean aerodynamic chord) with angle-of-attack sweeps from -8 deg to 60 deg, and yaw-angle sweeps from -8 deg to 36 deg at fixed angles of attack 0 deg, 10 deg, 20 deg, 25 deg, 30 deg, and 35 deg. Significant improvement in lift-curve slope, maximum lift, drag polar and lateral/directional stability was found, enlarging the flight envelope beyond its previous low-speed/maximum-lift limit. In spite of the highly swept (60 deg) leading edge, the efficiency of the lift augmentation by blowing was relatively high and was found to increase with increasing blowing momentum on the close-coupled-canard configuration. Interesting possibilities of obtaining much higher efficiencies with swirling jets were indicated.

  1. Evaluation of HFC 245ca and HFC 236ea as foam blowing agents

    NASA Technical Reports Server (NTRS)

    Sharpe, Jon; Macarthur, Doug; Kollie, Tom; Graves, Ron; Liu, Matthew; Hendriks, Robert V.

    1995-01-01

    Hydrochlorofluorocarbon (HCFC) 141b has been selected as the interim blowing agent for use in urethane insulations on NASA's Space Shuttle External Tank. Due to the expected limited commercial lifetime of this material, research efforts at the NASA Thermal Protection Systems Materials Research Laboratory at the Marshall Space Flight Center are now being devoted to the identification and development of alternatives with zero ozone depletion potential. Physical blowing agents identified to date have included hydrocarbons, fluorocarbons, hydrofluoroethers, and more predominantly, hydrofluorocarbons (HFCs). The majority of the HFC evaluations in industry have focused on the more readily available, low boiling candidates such as HFC 134a. Higher boiling HFC candidates that could be handled at ambient conditions and use current processing equipment would be more desirable. This paper will describe results from a research program of two such candidate HFC's performed as a cooperative effort between Martin Marietta Manned Space Systems, the U.S. Environmental Protection Agency, and Oak Ridge National Laboratories. The purpose of this effort was to perform a cursory evaluation of the developmental HFC's 245ca and 236ea as blowing agents in urethane based insulations. These two materials were selected from screening tests of 37 C2, C3, and C4 isomers based on physical properties, atmospheric lifetime, flammability, estimated toxicity, difficulty of synthesis, suitability for dual use as a refrigerant, and other factors. Solubility of the two materials in typical foam components was tested, pour foaming trials were performed, and preliminary data were gathered regarding foam insulation performance.

  2. Augmentation of Fighter-Aircraft Performance by Spanwise Blowing over the Wing Leading Edge

    NASA Technical Reports Server (NTRS)

    Seginer, A.; Salomon, M.

    1983-01-01

    Spanwise blowing over the wing and canard of a 1:35 model of a close-coupled-canard fighter airplane configuration (similar to the Kfir-C2) was investigated experimentally in low-speed flow. Tests were conducted at airspeeds of 30 m/sec (Reynolds number of 1.8 x 10 to the 5th power based on mean aerodynamic chord) with angle-of-attack sweeps from -8 to 60 deg, and yaw-angle sweeps from -8 to 36 deg at fixed angles of attack 0, 10, 20, 25, 30, and 35 deg. Significant improvement in lift-curve slope, maximum lift, drag polar and lateral/directional stability was found, enlarging the flight envelope beyond its previous low-speed/maximum-lift limit. In spite of the highly swept (60 deg) leading edge, the efficiency of the lift augmentation by blowing was relatively high and was found to increase with increasing blowing momentum on the close-coupled-canard configuration. Interesting possibilities of obtaining much higher efficiencies with swirling jets were indicated.

  3. Navier-Stokes Computations of a Wing-Flap Model With Blowing Normal to the Flap Surface

    NASA Technical Reports Server (NTRS)

    Boyd, D. Douglas, Jr.

    2005-01-01

    A computational study of a generic wing with a half span flap shows the mean flow effects of several blown flap configurations. The effort compares and contrasts the thin-layer, Reynolds averaged, Navier-Stokes solutions of a baseline wing-flap configuration with configurations that have blowing normal to the flap surface through small slits near the flap side edge. Vorticity contours reveal a dual vortex structure at the flap side edge for all cases. The dual vortex merges into a single vortex at approximately the mid-flap chord location. Upper surface blowing reduces the strength of the merged vortex and moves the vortex away from the upper edge. Lower surface blowing thickens the lower shear layer and weakens the merged vortex, but not as much as upper surface blowing. Side surface blowing forces the lower surface vortex farther outboard of the flap edge by effectively increasing the aerodynamic span of the flap. It is seen that there is no global aerodynamic penalty or benefit from the particular blowing configurations examined.

  4. Assessment of Potential Aerodynamic Benefits from Spanwise Blowing at the Wing Tip. Ph.D. Thesis - George Washington Univ.

    NASA Technical Reports Server (NTRS)

    Mineck, Raymond Edward

    1992-01-01

    A comprehensive set of experimental and analytical investigations have been conducted to assess the potential aerodynamic benefits from spanwise blowing at the tip of a moderate aspect ratio, swept wing. An analytical model has been developed to simulate a jet exhausting from the wing tip. An experimental study of a subsonic jet exhausting from the wing tip was conducted to investigate the effect of spanwise blowing from the tip on the aerodynamic characteristics of a moderate aspect ratio, swept wing. Wing force and moment data and surface pressure data were measured at Mach numbers up to 0.72. Results indicate that small amounts of blowing from small jets increase the lift curve slope a small amount, but have no effect on drag. Larger amounts of blowing from longer jets blowing increases lift near the tip and reduce drag at low Mach numbers. These benefits decrease with increasing Mach number, and vanish at Mach 0.5. A Navier-Stokes solver with modified boundary conditions at the tip was used to extrapolate the results to a Mach number of 0.72. With current technology and conventional wing shapes, spanwise blowing at the wing tip does not appear to be a practical means of reducing drag of moderate aspect ratio wings at high subsonic Mach numbers.

  5. Study of potential aerodynamic benefits from spanwise blowing at wingtip. Ph.D. Thesis - George Washington Univ., 1992

    NASA Technical Reports Server (NTRS)

    Mineck, Raymond E.

    1995-01-01

    Comprehensive experimental and analytical studies have been conducted to assess the potential aerodynamic benefits from spanwise blowing at the tip of a moderate-aspect-ratio swept wing. Previous studies on low-aspect-ratio wings indicated that blowing from the wingtip can diffuse the tip vortex and displace it outward. The diffused and displaced vortex will induce a smaller downwash at the wing, and consequently the wing will have increased lift and decreased induced drag at a given angle of attack. Results from the present investigation indicated that blowing from jets with a short chord had little effect on lift or drag, but blowing from jets with a longer chord increased lift near the tip and reduced drag at low Mach numbers. A Navier-Stokes solver with modified boundary conditions at the tip was used to extrapolate the results to a Mach number of 0.72. Calculations indicated that lift and drag increase with increasing jet momentum coefficient. Because the momentum of the jet is typically greater than the reduction in the wing drag and the increase in the wing lift due to spanwise blowing is small, spanwise blowing at the wingtip does not appear to be a practical means of improving the aerodynamic efficiency of moderate-aspectratio swept wings at high subsonic Mach numbers.

  6. Satellite Observations of Blowing Snow in and Around Antarctica: Implications for Ice Sheet Mass Balance and Atmospheric Chemistry

    NASA Astrophysics Data System (ADS)

    Palm, S. P.; Yang, Y.; Marshak, A.

    2014-12-01

    Blowing snow in the polar regions is known to be important for a variety of reasons including ice sheet mass balance, atmospheric water vapor transport, interpretation of paleoclimate records and atmospheric chemistry. Over Antarctica, persistent katabatic winds produce extreme blowing snow events often covering 100,000 square kilometers or more and reaching heights of 300-400 meters. New techniques of blowing snow detection using active and passive satellite data are providing a new understanding of the frequency, magnitude and spatial coverage of blowing snow over and around the Antarctic continent. Current research is utilizing these methods to obtain a nearly 10 year climatology of blowing snow events over Antarctica and estimate the amount of mass being blown off the continent and sublimated into the atmosphere on an annual basis. In addition, recent research indicates that blowing snow over sea ice may be important in the process of transporting seal salt aerosol into the atmosphere where it is implicated in the production of bromine compounds that strongly influence many aspects of tropospheric chemistry.

  7. An investigation of the effects of aft blowing on a 3.0 caliber tangent ogive body at high angles of attack. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Gittner, Nathan M.

    1992-01-01

    An experimental investigation of the effects of aft blowing on the asymmetric vortex flow of a slender, axisymmetric body at high angles of attack was conducted. A 3.0 caliber tangent ogive body fitted with a cylindrical afterbody was tested in a wind tunnel under subsonic, laminar flow test conditions. Asymmetric blowing from both a single nozzle and a double nozzle configuration, positioned near the body apex, was investigated. Aft blowing was observed to alter the vortex asymmetry by moving the blowing-side vortex closer to the body surface while moving the non-blowing-side vortex further away from the body. The effect of increasing the blowing coefficient was to move the blowing-side vortex closer to the body surface at a more upstream location. The data also showed that blowing was more effective in altering the initial vortex asymmetry at the higher angles of attack than at the lower. The effects of changing the nozzle exit geometry were investigated and it was observed that blowing from a nozzle with a low, broad exit geometry was more effective in reducing the vortex asymmetry than blowing from a high, narrow exit geometry.

  8. A Proof of Concept Experiment for Reducing Skin Friction by Using a Micro-Blowing Technique

    NASA Technical Reports Server (NTRS)

    Hwang, Danny P.

    1996-01-01

    A proof of concept experiment for reducing skin friction has been conducted in the Advanced Nozzle and Engine Components Test Facility at the NASA Lewis Research Center. In this unique concept, called the micro-blowing technique (MBT), an extremely small amount of air was blown vertically through very small holes to reduce the surface roughness and to control the gradient of the flow velocity profile on the surface thereby reducing skin friction. Research revealed that the skin was the most important factor to make this concept achievable. The proposed skin consisted of two layers. The inner layer was a low permeable porous skin for distributing the blowing air evenly while the outer layer with small holes controlled the vertical or nearly vertical blowing air. Preliminary experimental results showed that the MBT has the potential of a very large reduction in skin friction below the skin friction of a nonporous plain flat plate. Of the skins tested, three have been identified as the MBT skins. They provided very low unblown skin friction such that a large skin friction reduction, below a flat plate value, was achieved with very small amounts of blowing air. The reduction in skin friction of 55 percent was achieved at the Mach number of 0.3 for the exhaust pressure of 0.85 atm, and 60 percent reduction was obtained for the exhaust pressure of 0.24 atm (corresponding to 10 700-m altitude) at the same Mach number. A significant reduction in skin friction of over 25 percent was achieved for the exhaust pressure of 0.24 atm at the Mach number of 0.7. This implied that the MBT could be applied to a wide range of flight conditions. It is also believed that additional 10 percent reduction could be obtained by eliminating the gap between the inner layer and the outer layer. The aspect ratio of the vertical small holes for the outer layer of the MBT skin should be larger than 4 based on the preliminary conclusion from this test. Many experiments are needed to find out the

  9. FE-Analysis of Stretch-Blow Moulded Bottles Using an Integrative Process Simulation

    NASA Astrophysics Data System (ADS)

    Hopmann, C.; Michaeli, W.; Rasche, S.

    2011-05-01

    The two-stage stretch-blow moulding process has been established for the large scale production of high quality PET containers with excellent mechanical and optical properties. The total production costs of a bottle are significantly caused by the material costs. Due to this dominant share of the bottle material, the PET industry is interested in reducing the total production costs by an optimised material efficiency. However, a reduced material inventory means decreasing wall thicknesses and therewith a reduction of the bottle properties (e.g. mechanical properties, barrier properties). Therefore, there is often a trade-off between a minimal bottle weight and adequate properties of the bottle. In order to achieve the objectives Computer Aided Engineering (CAE) techniques can assist the designer of new stretch-blow moulded containers. Hence, tools such as the process simulation and the structural analysis have become important in the blow moulding sector. The Institute of Plastics Processing (IKV) at RWTH Aachen University, Germany, has developed an integrative three-dimensional process simulation which models the complete path of a preform through a stretch-blow moulding machine. At first, the reheating of the preform is calculated by a thermal simulation. Afterwards, the inflation of the preform to a bottle is calculated by finite element analysis (FEA). The results of this step are e.g. the local wall thickness distribution and the local biaxial stretch ratios. Not only the material distribution but also the material properties that result from the deformation history of the polymer have significant influence on the bottle properties. Therefore, a correlation between the material properties and stretch ratios is considered in an integrative simulation approach developed at IKV. The results of the process simulation (wall thickness, stretch ratios) are transferred to a further simulation program and mapped on the bottles FE mesh. This approach allows a local

  10. Experiments in aircraft roll-yaw control using forebody tangential blowing

    NASA Astrophysics Data System (ADS)

    Pedreiro, Nelson

    Flight at high angles of attack can provide improved maneuverability for fighter aircraft and increased lift capabilities for future supersonic and hypersonic transport aircraft during take-off and landing. At high angles of attack the aerodynamics of the vehicle are dominated by separation, vortex shedding and breakdown, which compromise the effectiveness of conventional control surfaces. As a result, controlled flight at high angles of attack is not feasible for current aircraft configurations. Alternate means to augment the control of the vehicle at these flight regimes are therefore necessary. In this work, the feasibility of using Forebody Tangential Blowing to control the roll-yaw motion of a wind tunnel model at high angles of attack is demonstrated. The method consists of injecting a thin sheet of air tangentially to the forebody of the vehicle to change the separation lines over the forebody and alter the aerodynamic loads. A unique model was developed that describes the unsteady aerodynamic moments generated by both vehicle motion and the applied blowing. This aerodynamic model is sufficiently detailed to predict transient motion of the wind-tunnel model, and is simple enough to be suitable for control logic design and implementation. Successful closed-loop control was demonstrated experimentally for a delta wing body model with a cone-cylinder fuselage. Experiments were performed at 45 degrees nominal angle of attack. At this condition, the natural motion of the system is divergent. A discrete vortex method was developed to help understand the main physics of the flow. The method correctly captures the interactions between forebody and wing vortices. Moreover, the trends in static loads and flow structure are correctly represented. Flow visualization results revealed the vortical structure of the flow to be asymmetric even for symmetric flight conditions. The effects of blowing, roll and yaw angles on the flow structure were determined. It was shown that

  11. Relationship inference based on DNA mixtures.

    PubMed

    Kaur, Navreet; Bouzga, Mariam M; Dørum, Guro; Egeland, Thore

    2016-03-01

    Today, there exists a number of tools for solving kinship cases. But what happens when information comes from a mixture? DNA mixtures are in general rarely seen in kinship cases, but in a case presented to the Norwegian Institute of Public Health, sample DNA was obtained after a rape case that resulted in an unwanted pregnancy and abortion. The only available DNA from the fetus came in form of a mixture with the mother, and it was of interest to find the father of the fetus. The mother (the victim), however, refused to give her reference data and so commonly used methods for paternity testing were no longer applicable. As this case illustrates, kinship cases involving mixtures and missing reference profiles do occur and make the use of existing methods rather inconvenient. We here present statistical methods that may handle general relationship inference based on DNA mixtures. The basic idea is that likelihood calculations for mixtures can be decomposed into a series of kinship problems. This formulation of the problem facilitates the use of kinship software. We present the freely available R package relMix which extends on the R version of Familias. Complicating factors like mutations, silent alleles, and θ-correction are then easily handled for quite general family relationships, and are included in the statistical methods we develop in this paper. The methods and their implementations are exemplified on the data from the rape case.

  12. Remarking on a blackened eye: Persifor Frazer's blow-by-blow account of a fistfight with his dear friend Edward Drinker Cope.

    PubMed

    Brinkman, Paul D

    2015-01-01

    Edward Drinker Cope, a brilliant and prolific American naturalist, was notoriously combative. His infamous feud with Yale paleontologist Othniel Charles Marsh, which played out publicly on the front pages of the New York Herald, was one of the worst scandals of nineteenth-century American science. Cope did not fight exclusively with his pen, however. In 1888, for example, he traded blows with his close friend Persifor Frazer over a matter of honor at the entrance of Philadelphia's hallowed Philosophical Hall, just as a meeting of the American Philosophical Society was getting under way. A six-page letter, handwritten by Persifor Frazer and housed in the Frazer Family Papers at the University of Pennsylvania, details the circumstances of their quarrel. An annotated transcription of Frazer's letter appears here.

  13. Seasonal and Geographic Variation in Biodiversity of Forensically Important Blow Flies (Diptera: Calliphoridae) in New Jersey, USA.

    PubMed

    Weidner, L M; Jennings, D E; Tomberlin, J K; Hamilton, G C

    2015-09-01

    Determining the time of colonization of human or other animal remains by blow flies (Diptera: Calliphoridae) can play an important role in criminal investigations. However, blow fly presence in a given area is strongly influenced by abiotic and biotic variables such as temperature and habitat. We wanted to assess the biodiversity of adult blow flies in New Jersey, USA, where very little is known about these taxa. Toward that end we collected adult blow flies biweekly from traps baited with bovine liver and placed across three regions in New Jersey over a 2-yr period (2011-2013). We collected and identified 9,257 adult calliphorids, comprising six genera and 12 species. Blow fly assemblages composed of these species varied by season, but community composition did not vary among regions within a given season. Three species, Lucilia coeruleiviridis (Macquart), Lucilia sericata (Meigen), and Phormia regina (Meigen) comprised 88.5% of all adult blow flies collected (42.6, 25.9, 20.0%, respectively). Combining all regions, the dominant species for both spring and summer was L. coeruleiviridis comprising 35.1% of all adults caught in spring and 64.1% in summer. P. regina was the dominant species in fall, totaling 40.1% of all adults caught and Calliphora vicina (Robineau-Desvoidy) was the dominant species for winter, totaling 44.8% of all adults caught. Our findings provide the first assessment of blow fly communities in New Jersey, and these results can be applied to surrounding states where data are severely lacking for forensic application.

  14. On Involvement.

    ERIC Educational Resources Information Center

    Greene, Michael B.

    Involvement Ratings In Settings (IRIS), a multi-dimensional non-verbal scale of involvement adaptable to a time-sampling method of data collection, was constructed with the aid of the videotapes of second-grade Follow Through classrooms made by CCEP. Scales were defined through observations of involved and alienated behavior, and the IRIS was…

  15. Mixture including hydrogen and hydrocarbon having pressure-temperature stability

    NASA Technical Reports Server (NTRS)

    Mao, Wendy L. (Inventor); Mao, Ho-Kwang (Inventor)

    2009-01-01

    The invention relates to a method of storing hydrogen that employs a mixture of hydrogen and a hydrocarbon that can both be used as fuel. In one embodiment, the method involves maintaining a mixture including hydrogen and a hydrocarbon in the solid state at ambient pressure and a temperature in excess of about 10 K.

  16. Thermo-mechanical simulation of liquid-supported stretch blow molding

    SciTech Connect

    Zimmer, J.; Stommel, M.

    2015-05-22

    Stretch blow molding is the well-established plastics forming method to produce Polyehtylene therephtalate (PET) bottles. An injection molded preform is heated up above the PET glass transition temperature (Tg∼85°C) and subsequently inflated by pressurized air into a closed cavity. In the follow-up filling process, the resulting bottle is filled with the final product. A recently developed modification of the process combines the blowing and filling stages by directly using the final liquid product to inflate the preform. In a previously published paper, a mechanical simulation and successful evaluation of this liquid-driven stretch blow molding process was presented. In this way, a realistic process parameter dependent simulation of the preform deformation throughout the forming process was enabled, whereas the preform temperature evolution during forming was neglected. However, the formability of the preform is highly reduced when the temperature sinks below Tg during forming. Experimental investigations show temperature-induced failure cases due to the fast heat transfer between hot preform and cold liquid. Therefore, in this paper, a process dependent simulation of the temperature evolution during processing to avoid preform failure is presented. For this purpose, the previously developed mechanical model is used to extract the time dependent thickness evolution. This information serves as input for the heat transfer simulation. The required material parameters are calibrated from preform cooling experiments recorded with an infrared-camera. Furthermore, the high deformation ratios during processing lead to strain induced crystallization. This exothermal reaction is included into the simulation by extracting data from preform measurements at different stages of deformation via Differential Scanning Calorimetry (DSC). Finally, the thermal simulation model is evaluated by free forming experiments, recorded by a high-speed infrared camera.

  17. Thermo-mechanical simulation of liquid-supported stretch blow molding

    NASA Astrophysics Data System (ADS)

    Zimmer, J.; Stommel, M.

    2015-05-01

    Stretch blow molding is the well-established plastics forming method to produce Polyehtylene therephtalate (PET) bottles. An injection molded preform is heated up above the PET glass transition temperature (Tg˜85°C) and subsequently inflated by pressurized air into a closed cavity. In the follow-up filling process, the resulting bottle is filled with the final product. A recently developed modification of the process combines the blowing and filling stages by directly using the final liquid product to inflate the preform. In a previously published paper, a mechanical simulation and successful evaluation of this liquid-driven stretch blow molding process was presented. In this way, a realistic process parameter dependent simulation of the preform deformation throughout the forming process was enabled, whereas the preform temperature evolution during forming was neglected. However, the formability of the preform is highly reduced when the temperature sinks below Tg during forming. Experimental investigations show temperature-induced failure cases due to the fast heat transfer between hot preform and cold liquid. Therefore, in this paper, a process dependent simulation of the temperature evolution during processing to avoid preform failure is presented. For this purpose, the previously developed mechanical model is used to extract the time dependent thickness evolution. This information serves as input for the heat transfer simulation. The required material parameters are calibrated from preform cooling experiments recorded with an infrared-camera. Furthermore, the high deformation ratios during processing lead to strain induced crystallization. This exothermal reaction is included into the simulation by extracting data from preform measurements at different stages of deformation via Differential Scanning Calorimetry (DSC). Finally, the thermal simulation model is evaluated by free forming experiments, recorded by a high-speed infrared camera.

  18. Bottle-blowing in hospital-treated patients with community-acquired pneumonia.

    PubMed

    Björkqvist, M; Wiberg, B; Bodin, L; Bárány, M; Holmberg, H

    1997-01-01

    A study was carried out to determine whether bottle-blowing has any positive effects in patients with pneumonia. In a prospective open study 145 adults with untreated community-acquired pneumonia requiring hospitalization were randomized to early mobilization (group A), to sit up and take 20 deep breaths on 10 occasions daily (group B), or to sit up and to blow bubbles in a bottle containing 10 cm water through a plastic tube 20 times on 10 occasions daily (group C). Peak expiratory flow (PEF), vital capacity (VC), forced expiratory volume in 1 sec (FEV1) and serum concentration of C-reactive protein (CRP) were determined on admission, and on days 4 and 42. Fever duration and hospital stay were recorded. In a subset of 16 patients, single breath diffusion capacity of carbon monoxide was measured on 3 occasions. The patients in group A were hospitalized for a mean of 5.3 days, group B for 4.6 days and group C for 3.9 days. Treatment was a significant factor (p = 0.037) in a Cox regression model, with group C significantly better than group A (p = 0.01). The number of days with fever was 2.3, 1.7 and 1.6 in groups A, B and C respectively. These differences were not significant (p = 0.28). No significant differences were found between the groups regarding CRP, PEF, VC, FEV1, or diffusion capacity. Intensive bottle-blowing shortens the hospital stay in patients with pneumonia. The underlying mechanism is not clear.

  19. Trailing Edge Blowing on a Two-Dimensional Six-Percent Thick Elliptical Circulation Control Airfoil Up to Transonic Conditions

    NASA Technical Reports Server (NTRS)

    Alexander, Michael G.; Anders, Scott G.; Johnson, Stuart K.; Florance, Jennifer P.; Keller, Donald F.

    2005-01-01

    A wind tunnel test was conducted in the NASA Langley Transonic Dynamics Tunnel (TDT) on a six percent thick slightly cambered elliptical circulation control airfoil with both upper and lower surface blowing capability. Parametric evaluations of jet slot heights and Coanda surface shapes were conducted at momentum coefficients (Cm) from 0.0 to 0.12. Test data were acquired at Mach numbers of 0.3, 0.5, 0.7, 0.8, and 0.84 at Reynolds numbers per foot of 2.43 x 105 to 1.05 x 106. For a transonic condition, (Mach = 0.8 at alpha = 3 degrees), it was generally found the smaller slot and larger Coanda surface combination was overall more effective than other slot/Coanda surface combinations. Lower surface blowing was not as effective as the upper surface blowing over the same range of momentum coefficients. No appreciable Coanda surface, slot height, or slot blowing position preference was indicated transonically with the dual slot blowing.

  20. Flow visualization of leading-edge vortex enhancement by spanwise blowing. [swept wings - wind tunnel stability tests

    NASA Technical Reports Server (NTRS)

    Erickson, G. E.; Campbell, J. F.

    1975-01-01

    Flow visualization studies were conducted in a small pilot wind tunnel to determine qualitative effects of blowing a discrete jet essentially parallel to the leading edge of a 45 deg-swept trapezoidal wing featuring leading- and trailing-edge flaps. Test parameters included wing angle-of-attack, jet momentum coefficient, leading- and trailing-edge flap deflections, and nozzle chordwise displacement. Results of this study indicate that blowing from a reflection plane over the wing enhances the leading-edge vortex and delays vortex bursting to higher angles-of-attack and greater span distances. Increased blowing rates decrease vortex size, growth rate, and vertical displacement above the wing surface at a given span station and also extend the spanwise effectiveness of lateral blowing. Deflection of a leading-edge flap delays the beneficial effects of spanwise blowing to higher angles-of-attack. Nozzle chordwise locations investigated for the wing with and without leading-edge flap deflection appear equally effective in enhancing the separated leading-edge flow.

  1. Cloning, recombinant expression and inhibitor profiles of dihydrofolate reductase from the Australian sheep blow fly, Lucilia cuprina.

    PubMed

    Kotze, A C; Bagnall, N H; Ruffell, A P; Pearson, R

    2014-09-01

    While dihydrofolate reductase (DHFR) is an important drug target in mammals, bacteria and protozoa, no inhibitors of this enzyme have been developed as commercial insecticides. We therefore examined the potential of this enzyme as a drug target in an important ectoparasite of livestock, the Australian sheep blow fly, Lucilia cuprina (Diptera: Calliphoridae) (Wiedemann). The non-specific DHFR inhibitors aminopterin and methotrexate significantly inhibited the growth of L. cuprina larvae, with IC50 values at µg levels. Trimethoprim and pyrimethamine were 5-30-fold less active. Relative IC50 values for the inhibition of recombinant L. cuprina DHFR by various inhibitors were in accordance with their relative effects on larval growth. The active-site amino acid residues of L. cuprina DHFR differed by between 34% and 50% when compared with two mammalian species, as well as two bacteria and two protozoa. There were significant charge and size differences in specific residues between the blow fly and human DHFR enzymes, notably the L. cuprina Asn21, Lys31 and Lys63 residues. This study provides bioassay evidence to highlight the potential of blow fly DHFR as an insecticide target, and describes differences in active site residues between blow flies and other organisms which could be exploited in the design of blow fly control chemicals.

  2. A paradigm for operant conditioning in blow flies (Phormia terrae novae Robineau-Desvoidy, 1830).

    PubMed

    Sokolowski, Michel B C; Disma, Gérald; Abramson, Charles I

    2010-01-01

    An operant conditioning situation for the blow fly (Protophormia terrae novae) is described. Individual flies are trained to enter and reenter a hole as the operant response. Only a few sessions of contingent reinforcement are required to increase response rates. When the response is no longer followed by food, the rate of entering the hole decreases. Control procedures revealed that rate of responding is not a simple overall result of feeding or of aging. The flies entered into the hole only if the response was required to obtain the food.

  3. A wing-jet interaction theory for USB configurations. [Upper Surface Blowing

    NASA Technical Reports Server (NTRS)

    Lan, C. E.; Campbell, J. F.

    1976-01-01

    The aerodynamic interaction between the wing and an inviscid upper-surface blowing (USB) thick jet with Mach number nonuniformity is treated within the framework of a linear inviscid subsonic compressible flow theory. A two-vortex-sheet model for the jet surface is used to represent the induced flowfields inside and outside the jet. Comparison of the predicted results with experimental data shows good agreement in lift, induced drag, and pitching moment. It is shown that the thin jet flap theory is inadequate for USB configurations with thick jet.

  4. A numerical study of transition control by periodic suction-blowing

    NASA Technical Reports Server (NTRS)

    Biringen, Sedat

    1987-01-01

    The applicability of active control of transition by periodic suction-blowing is investigated via direct numerical simulations of the Navier-Stokes equations. The time-evolution of finite-amplitude disturbances in plane channel flow is compared in detail with and without control. The analysis indicates that, for relatively small three dimensional amplitudes, a two dimensional control effectively reduces disturbance growth rates even for linearly unstable Reynolds numbers. After the flow goes through secondary instability, three dimensional control seems necessary to stabilize the flow. An investigation of the temperature field suggests that passive temperature contamination is operative to reflect the flow dynamics during transition.

  5. Sea-floor methane blow-out and global firestorm at the K-T boundary

    USGS Publications Warehouse

    Max, M.D.; Dillon, William P.; Nishimura, C.; Hurdle, B.G.

    1999-01-01

    A previously unsuspected source of fuel for the global firestorm recorded by soot in the Cretaceous-Tertiary impact layer may have resided in methane gas associated with gas hydrate in the end-Cretaceous seafloor. End-Cretaceous impact-generated shock and megawaves would have had the potential to initiate worldwide oceanic methane gas blow-outs from these deposits. The methane would likely have ignited and incompletely combusted. This large burst of methane would have been followed by longer-term methane release as a part of a positive thermal feedback in the disturbed ocean-atmosphere system.

  6. Use of Chromatography Techniques to Separate a Mixture of Substances

    ERIC Educational Resources Information Center

    Donaldson, W.

    1976-01-01

    Explains the separation of the constituents of mixtures on one piece of chromatography paper. The example presented involves a vitamin C tablet, a disprin tablet, and a glucose tablet. Outlined are two methods for separating the constituents. (GS)

  7. Transcriptional responses to complex mixtures: a review.

    PubMed

    Sen, Banalata; Mahadevan, Brinda; DeMarini, David M

    2007-01-01

    Exposure of people to hazardous compounds is primarily through complex environmental mixtures, those that occur through media such as air, soil, water, food, cigarette smoke, and combustion emissions. Microarray technology offers the ability to query the entire genome after exposure to such an array of compounds, permitting a characterization of the biological effects of such exposures. This review summarizes the published literature on the transcriptional profiles resulting from exposure of cells or organisms to complex environmental mixtures such as cigarette smoke, diesel emissions, urban air, motorcycle exhaust, carbon black, jet fuel, and metal ore and fumes. The majority of the mixtures generally up-regulate gene expression, with heme oxygenase 1 and CYP1A1 being up-regulated by all of the mixtures. Most of the mixtures altered the expression of genes involved in oxidative stress response (OH-1, metallothioneins), immune/inflammation response (IL-1b, protein kinase), xenobiotic metabolism (CYP1A1, CYP1B1), coagulation and fibrinolysis (plasminogen activator/inhibitor), proto-oncogenes (FUS1, JUN), heat-shock response (HSP60, HSP70), DNA repair (PCNA, GADD45), structural unit of condensed DNA (Crf15Orf16, DUSP 15), and extracellular matrix degradation (MMP1, 8, 9, 11, 12). Genes involved in aldehyde metabolism, such as ALDH3, appeared to be uniquely modulated by cigarette smoke. Cigarette smoke-exposed populations have been successfully distinguished from control nonexposed populations based on the expression pattern of a subset of genes, thereby demonstrating the utility of this approach in identifying biomarkers of exposure and susceptibility. The analysis of gene-expression data at the pathway and functional level, along with a systems biology approach, will provide a more comprehensive insight into the biological effects of complex mixtures and will improve risk assessment of the same. We suggest critical components of study design and reporting that will

  8. Transcriptional responses to complex mixtures: a review.

    PubMed

    Sen, Banalata; Mahadevan, Brinda; DeMarini, David M

    2007-01-01

    Exposure of people to hazardous compounds is primarily through complex environmental mixtures, those that occur through media such as air, soil, water, food, cigarette smoke, and combustion emissions. Microarray technology offers the ability to query the entire genome after exposure to such an array of compounds, permitting a characterization of the biological effects of such exposures. This review summarizes the published literature on the transcriptional profiles resulting from exposure of cells or organisms to complex environmental mixtures such as cigarette smoke, diesel emissions, urban air, motorcycle exhaust, carbon black, jet fuel, and metal ore and fumes. The majority of the mixtures generally up-regulate gene expression, with heme oxygenase 1 and CYP1A1 being up-regulated by all of the mixtures. Most of the mixtures altered the expression of genes involved in oxidative stress response (OH-1, metallothioneins), immune/inflammation response (IL-1b, protein kinase), xenobiotic metabolism (CYP1A1, CYP1B1), coagulation and fibrinolysis (plasminogen activator/inhibitor), proto-oncogenes (FUS1, JUN), heat-shock response (HSP60, HSP70), DNA repair (PCNA, GADD45), structural unit of condensed DNA (Crf15Orf16, DUSP 15), and extracellular matrix degradation (MMP1, 8, 9, 11, 12). Genes involved in aldehyde metabolism, such as ALDH3, appeared to be uniquely modulated by cigarette smoke. Cigarette smoke-exposed populations have been successfully distinguished from control nonexposed populations based on the expression pattern of a subset of genes, thereby demonstrating the utility of this approach in identifying biomarkers of exposure and susceptibility. The analysis of gene-expression data at the pathway and functional level, along with a systems biology approach, will provide a more comprehensive insight into the biological effects of complex mixtures and will improve risk assessment of the same. We suggest critical components of study design and reporting that will

  9. Flow visualization of vortices locked by spanwise blowing over wings featuring a unique leading and trailing-edge flap system

    NASA Technical Reports Server (NTRS)

    Erickson, G. E.; Campbell, J. F.

    1975-01-01

    Flow visualization studies were conducted to qualitatively determine the effects of active generation and augmentation of vortex flow over wings by blowing a discrete jet in a spanwise direction in the channel formed by extension of upper surface leading- and trailing-edge flaps. Spanwise blowing from a reflection plane over a rectangular wing was found to generate and lock a dual corotating vortex system within the channel and, at sufficient blowing rates, cause the separated flow off the upper end of the leading-edge flap to reattach to the trailing-edge flap. Test parameters included wing angle of attack, jet momentum coefficient, leading- and trailing-edge flap deflection angle, and jet location above the wing surface. Effects due to removal of the leading- and trailing-edge flap were also investigated.

  10. The Food Preferences of the Blow Fly Lucilia cuprina Offered Human Blood, Semen and Saliva, and Various Nonhuman Foods Sources.

    PubMed

    Durdle, Annalisa; Mitchell, Robert J; van Oorschot, Roland A H

    2016-01-01

    As human DNA profiles can be obtained from blow fly artifacts, this study aimed to establish the feeding preferences of Lucilia cuprina (Wiedemann) blow flies when offered human biological fluids and nonhuman food sources. One-day-old and 3-day-old blow flies of both sexes were simultaneously offered human blood, semen and saliva, pet food, canned tuna and honey, and the number and length of visits documented over 6 h. One-day-old flies visited pet food and honey most often, but stayed longest on honey and semen. Three-day-old flies visited semen and pet food most often, and stayed longest on these food sources. Blood and saliva were the least preferred options for all flies. Overall, flies preferred dry blood and semen to the wet forms. These findings demonstrate that even when other food sources are available, flies at a crime scene may feed on human biological fluids if present, potentially transferring human DNA. PMID:26211393

  11. Evidence for a Significant Source of Sea Salt Aerosol from Blowing Snow Above Sea Ice in the Southern Ocean

    NASA Astrophysics Data System (ADS)

    Frey, M. M.; Brooks, I. M.; Anderson, P. A.; Nishimura, K.; Yang, X.; Jones, A. E.; Wolff, E. W.

    2014-12-01

    Over most of the Earth, sea salt aerosol (SSA) derives from sea spray and bubble bursting at the open ocean surface. SSA as the major component of marine aerosol contributes directly to the radiative balance and can act as cloud condensation nuclei. SSA can also significantly impact the lifetime of methane, ozone or mercury through the photochemical release of reactive halogens. A recent model study suggested that the sublimation of saline blowing snow above sea ice can generate more SSA than is produced from a similar area of open ocean. A winter cruise through the Weddell Sea during June - August 2013 provided unique access to a potential SSA source region in the Antarctic sea ice zone to test this hypothesis.Reported are first measurements of snow particle as well as aerosol concentrations, size distributions and chemical composition, during blowing snow events above sea ice. Snow particle spectra are found to be similar to those observed on the continent. Even though the salinity of surface and blowing snow was very low (<0.1 psu) a significant increase of aerosol in the SSA size range was observed during and after blowing snow events. This is consistent with model runs including a blowing snow parameterisation which suggest low sensitivity of SSA number densities to snow salinity within the observed range. First estimates of SSA flux from blowing snow using eddy correlation are significant, although falling below published values of the sea spray source function. We discuss the dependance of observed SSA production rates on ambient conditions as well as the significance to the Southern Ocean environment.

  12. Foam injection molding of poly(lactic acid) with physical blowing agents

    NASA Astrophysics Data System (ADS)

    Pantani, R.; Sorrentino, A.; Volpe, V.; Titomanlio, G.

    2014-05-01

    Foam injection molding uses environmental friendly blowing agents under high pressure and temperature to produce parts having a cellular core and a compact solid skin (the so-called "structural foam"). The addition of a supercritical gas reduces the part weight and at the same time improves some physical properties of the material through the promotion of a faster crystallization; it also leads to the reduction of both the viscosity and the glass transition temperature of the polymer melt, which therefore can be injection molded adopting lower temperatures and pressures. These aspects are of extreme interest for biodegradable polymers, which often present a very narrow processing window, with the suitable processing temperatures close to the degradation conditions. In this work, foam injection molding was carried out by an instrumented molding machine, able to measure the pressure evolution in different positions along the flow-path. The material adopted was a biodegradable polymer, namely the Poly(lactic acid), PLA. The effect of a physical blowing agent (PBA) on the viscosity was measured. The density reduction and the morphology of parts obtained by different molding conditions was assessed.

  13. Aerodynamic drag reduction of a simplified squareback vehicle using steady blowing

    NASA Astrophysics Data System (ADS)

    Littlewood, R. P.; Passmore, M. A.

    2012-08-01

    A large contribution to the aerodynamic drag of a vehicle arises from the failure to fully recover pressure in the wake region, especially on squareback configurations. A degree of base pressure recovery can be achieved through careful shape optimisation, but the freedom of an automotive aerodynamicist to implement significant shape changes is limited by a variety of additional factors such styling, ergonomics and loading capacity. Active flow control technologies present the potential to create flow field modifications without the need for external shape changes and have received much attention in previous years within the aeronautical industry and, more recently, within the automotive industry. In this work the influence of steady blowing applied at a variety of angles on the roof trailing edge of a simplified ¼ scale squareback style vehicle has been investigated. Hot-wire anemometry, force balance measurements, surface pressure measurements and PIV have been used to investigate the effects of the steady blowing on the vehicle wake structures and the resulting body forces. The energy consumption of the steady jet is calculated and is used to deduce an aerodynamic drag power change. Results show that overall gains can be achieved; however, the large mass flow rate required restricts the applicability of the technique to road vehicles. Means by which the mass flow rate requirements of the jet may be reduced are discussed and suggestions for further work put forward.

  14. Sea salt aerosol from blowing snow on sea ice - modeling vs observation

    NASA Astrophysics Data System (ADS)

    Yang, Xin; Frey, Markus; Norris, Sarah; Brooks, Ian; Anderson, Philip; Jones, Anna; wolff, Eric; Legrand, Michel

    2016-04-01

    Blowing snow over sea ice, through a subsequent sublimation process of salt-containing blown snow particles, has been hypothesized as a significant sea salt aerosol (SSA) source in high latitudes. This mechanism has been strongly supported by a winter cruise in the Weddell Sea (during June-August 2013). The newly collected data, including both physical and chemical components, provide a unique way to test and validate the parameterisation used for describing the SSA production from blowing snow events. With updates to some key parameters such as snow salinity in a global Chemistry-transport model pTOMCAT, simulated SSA concentrations can be well compared with measured SSA data. In this presentation, I will report modeled SSA number density against collected data on board of Polarstern ship during the Weddell Sea cruise, as well as modeled SSA massive concentrations against those measured at both coastal sites such as Alert in the North and Dumont d'Urville (DDU) in the South and central Antarctic sites such as Concordia and Kohnen stations. Model experiments indicated that open ocean-sourced SSA could not explain the observed winter SSA peaks seen in most polar sites, while with sea ice-sourced SSA in the model, the winter peaks can be well improved indicating the importance of sea ice-sourced SSA as a significant contributor to the salts (Na+, Cl-) recorded in the ice core.

  15. Antimicrobial Poly(lactic acid)-Based Nanofibres Developed by Solution Blow Spinning.

    PubMed

    Martínez-Sanz, Marta; Bilbao-Sainz, Cristina; Du, Wen-Xian; Chiou, Bor-Sen; Williams, Tina G; Wood, Delilah F; Imam, Syed H; Orts, William J; Lopez-Rubio, Amparo; Lagaron, Jose M

    2015-01-01

    The present study reports on the development of hybrid poly(lactic acid) (PLA) fibres loaded with highly crystalline bacterial cellulose nanowhiskers (BCNW) by the novel solution blow spinning method. Furthermore, fibres with antimicrobial properties were generated by incorporating carvacrol and THC as antimicrobial agents and the biocide effect against Listeria monocytogenes was studied. Initially, PLA blow spun fibres containing BCNW were optimized in terms of morphology and thermal properties. The addition of BCNW was seen to significantly increase the viscosity and surface tension of solutions, restricting the capacity to form fibres for concentrations greater than 30 wt.-% BCNW. 15 wt.-% BCNW was selected as the optimum nanofiller loading as it led to the most uniform fibres morphology, with BCNW homogeneously distributed along the fibres' axis. Subsequently, carvacrol and THC were incorporated into the fibres to confer them with antimicrobial properties, although the hydrophobic PLA matrix did not provide an efficient release of the antimicrobials. Thus, hydrophilic substances were added in order to trigger the antimicrobials release through water sorption mechanisms. The addition of the BCNW filler was not seen to significantly increase the antimicrobial capacity of the fibres by itself and, hence, gelatin was added to help promoting further the hydrophylicity and biocide performance of the fibres. Nevertheless, for the more hydrophilic THC, the biocide capacity of the fibres with gelatin was accentuated further by the presence of the BCNW.

  16. Blow-out protector and fire control system for petroleum exploration

    SciTech Connect

    Caraway, M.F.; Caraway, B.L.

    1987-10-06

    A blow-out protector is described for an oil well comprising a housing having a vertical passageway therethrough for a Kelly. The housing has a lower end adapter flange to be connected to a well casing, an elastomeric body having an opening for the Kelly and carried on the Kelly for providing sealing contact with the Kelly and housing passageway, a catch ring secured to the Kelly and having a surface defined by a given diameter, a compressor ring plate positioned below the elastomeric body on the Kelly, means on an interior of the housing having a given diameter and preventing the compressor ring plate from falling down and yet providing engagement with the surface of the catch ring, the compressor ring plate having a hole for passage of the Kelly drive-mechanism for the drill pipe, the catch ring on the Kelly positioned below the compressor plate. The diameter of the catch ring is smaller than the diameter of the interior means on the housing so that when the Kelly is pulled up the catch ring will contact and force the compressor ring plate against the elastomeric body and force the elastomeric body into tight contact with both the Kelly and the housing thus sealing the space between the Kelly and the housing against a blow-out.

  17. A Numerical Study of Anti-Vortex Film Cooling Designs at High Blowing Ratio

    NASA Technical Reports Server (NTRS)

    Heidmann, James D.

    2008-01-01

    A concept for mitigating the adverse effects of jet vorticity and liftoff at high blowing ratios for turbine film cooling flows has been developed and studied at NASA Glenn Research Center. This "anti-vortex" film cooling concept proposes the addition of two branched holes from each primary hole in order to produce a vorticity counter to the detrimental kidney vortices from the main jet. These vortices typically entrain hot freestream gas and are associated with jet separation from the turbine blade surface. The anti-vortex design is unique in that it requires only easily machinable round holes, unlike shaped film cooling holes and other advanced concepts. The anti-vortex film cooling hole concept has been modeled computationally for a single row of 30deg angled holes on a flat surface using the 3D Navier-Stokes solver Glenn-HT. A modification of the anti-vortex concept whereby the branched holes exit adjacent to the main hole has been studied computationally for blowing ratios of 1.0 and 2.0 and at density ratios of 1.0 and 2.0. This modified concept was selected because it has shown the most promise in recent experimental studies. The computational results show that the modified design improves the film cooling effectiveness relative to the round hole baseline and previous anti-vortex cases, in confirmation of the experimental studies.

  18. Modeling Intense Blowing Snow Events in the Cariboo Mountains of British Columbia, Canada

    NASA Astrophysics Data System (ADS)

    Dery, S. J.; Ainslie, B.; Jackson, P. L.

    2010-12-01

    This presentation will investigate blowing snow associated with intense winter storms in the Cariboo Mountains of British Columbia, Canada. The objectives of the study are: 1) to examine four winter storms that affected the Cariboo Mountains between 2006 and 2009; 2) to assess snow mass redistribution by wind during the events, including areas of snow accumulation and erosion; and 3) to discuss the potential impacts of blowing snow on glacier mass balance and their hydrological consequences. To achieve these goals, simulations with a mesoscale atmospheric model (RAMS) of four high wind events are performed over the domain of the Cariboo Mountains. The simulations are validated using in-situ observations recorded at several high elevation sites. The spatial distribution of snow mass erosion/deposition, in addition to aeolian sublimation, is then assessed for each case study using the surface divergence/convergence field and other meteorological conditions simulated by RAMS. The talk will end with a discussion of the potential impacts of wind transport of snow on glacier mass balance in the region.

  19. Propagation dynamics of laterally colliding plasma plumes in laser-blow-off of thin film

    SciTech Connect

    Kumar, Bhupesh; Singh, R. K.; Sengupta, Sudip; Kaw, P. K.; Kumar, Ajai

    2014-08-15

    We report a systematic investigation of two plume interactions at different spatial separation (3-7 mm) in laser-blow-off. The plasmas plumes are created using Laser-blow-off (LBO) scheme of a thin film. The fast imaging technique is used to record the evolution of seed plasmas and the interaction zone which is formed as a result of interaction of the two seed plasmas. Time resolved optical emission spectroscopy is used to study evolution of optical emissions of the species present in the different regions of the plasmas. Neutral Li emissions (Li I 670.8 nm (2s {sup 2}S{sub 1/2} ← 2p {sup 2}P{sub 3/2,1/2}) and Li I 610.3 nm (2p {sup 2}P{sub 3/2,1/2} ← 3d {sup 2}D{sub 3/2,5/2})) are dominant in the plasmas but significant differences are observed in the emission and estimated plasma parameters of the seed and the interaction zone. The transport of plasma species from the seed plasmas to the interaction zone is discussed in the terms of plume divergence, kinetic energy of particles, and ion acoustic speed. An attempt is made to understand the formation and dynamics of the interaction zone in the colliding LBO seed plasmas.

  20. Pattern injuries from blows with the muzzle end of a handgun.

    PubMed

    Geisenberger, D; Vogt, S; Pircher, R; Kramer, L; Pollak, S; Grosse Perdekamp, M

    2015-12-01

    Pistols, revolvers and blank guns are not only used to discharge cartridges, but also for hits to the victim. In such cases, the blows preferably affect the head and/or the interposed hands protecting the body. The impact is mostly exerted either by the grip of a pistol or the butt of a revolver. In vigorous thrusts inflicted with the muzzle end of the weapon, the edge of the barrel may produce circular punch lesions with central skin flaps roughly corresponding to the bore. As in other kinds of pistol-whipping, the scalp wounds may be associated with fractures of the skull and even with brain contusions. Using the example of a homicide committed by pistol-whipping, the morphological features of blunt injuries from a handgun's muzzle are presented. The characteristic wound pattern found on the victim's head could be reproduced experimentally by forceful blows to the forehead of a slaughtered pig. In the case presented, the dominant hand of the perpetrator showed friction blisters due to prolonged striking with an unhandy tool in the form of a pistol.

  1. Micro Blowing Simulations Using a Coupled Finite-Volume Lattice-Boltzman n L ES Approach

    NASA Technical Reports Server (NTRS)

    Menon, S.; Feiz, H.

    1990-01-01

    Three dimensional large-eddy simulations (LES) of single and multiple jet-in-cross-flow (JICF) are conducted using the 19-bit Lattice Boltzmann Equation (LBE) method coupled with a conventional finite-volume (FV) scheme. In this coupled LBE-FV approach, the LBE-LES is employed to simulate the flow inside the jet nozzles while the FV-LES is used to simulate the crossflow. The key application area is the use of this technique is to study the micro blowing technique (MBT) for drag control similar to the recent experiments at NASA/GRC. It is necessary to resolve the flow inside the micro-blowing and suction holes with high resolution without being restricted by the FV time-step restriction. The coupled LBE-FV-LES approach achieves this objectives in a computationally efficient manner. A single jet in crossflow case is used for validation purpose and the results are compared with experimental data and full LBE-LES simulation. Good agreement with data is obtained. Subsequently, MBT over a flat plate with porosity of 25% is simulated using 9 jets in a compressible cross flow at a Mach number of 0.4. It is shown that MBT suppresses the near-wall vortices and reduces the skin friction by up to 50 percent. This is in good agreement with experimental data.

  2. Antimicrobial Poly(lactic acid)-Based Nanofibres Developed by Solution Blow Spinning.

    PubMed

    Martínez-Sanz, Marta; Bilbao-Sainz, Cristina; Du, Wen-Xian; Chiou, Bor-Sen; Williams, Tina G; Wood, Delilah F; Imam, Syed H; Orts, William J; Lopez-Rubio, Amparo; Lagaron, Jose M

    2015-01-01

    The present study reports on the development of hybrid poly(lactic acid) (PLA) fibres loaded with highly crystalline bacterial cellulose nanowhiskers (BCNW) by the novel solution blow spinning method. Furthermore, fibres with antimicrobial properties were generated by incorporating carvacrol and THC as antimicrobial agents and the biocide effect against Listeria monocytogenes was studied. Initially, PLA blow spun fibres containing BCNW were optimized in terms of morphology and thermal properties. The addition of BCNW was seen to significantly increase the viscosity and surface tension of solutions, restricting the capacity to form fibres for concentrations greater than 30 wt.-% BCNW. 15 wt.-% BCNW was selected as the optimum nanofiller loading as it led to the most uniform fibres morphology, with BCNW homogeneously distributed along the fibres' axis. Subsequently, carvacrol and THC were incorporated into the fibres to confer them with antimicrobial properties, although the hydrophobic PLA matrix did not provide an efficient release of the antimicrobials. Thus, hydrophilic substances were added in order to trigger the antimicrobials release through water sorption mechanisms. The addition of the BCNW filler was not seen to significantly increase the antimicrobial capacity of the fibres by itself and, hence, gelatin was added to help promoting further the hydrophylicity and biocide performance of the fibres. Nevertheless, for the more hydrophilic THC, the biocide capacity of the fibres with gelatin was accentuated further by the presence of the BCNW. PMID:26328414

  3. Hydrochlorofluorocarbon (HCFC) blowing agents for foam insulation of launch vehicle cryogenic propellant tanks

    SciTech Connect

    Strauss, L. ); Bzik, J.W. )

    1992-01-01

    This paper reports on two polyurethane spray-on foam insulations (SOFI) that were evaluated with five hydrochlorofluorocarbon (HCFC) blowing agents each (HCFC-141b, HCFC-123, and three blends). Foams were evaluated by measuring bond and flatwise tension strengths at four temperatures, compression at ambient temperature, and substrate strain compatibility at liquid helium temperature. Additionally, foams were characterized for density, closed-cell content, oxygen index, and ablation under radiant heating. Compression strengths of RDB-1-152 (polyether polyol) exceeded those of SS-1825 SOFI (polyester/polyether blend). Highest compression and tensile strengths were for foams sprayed with HCFC-141b and strengths decreased with increasing HCFC-123 content in the blowing agent. No foam failures occurred adhesively at the aluminum substrate, but a high incidence of premature failures occurred in the knitline between successive spray layers. Process optimization studies will be conducted with the two best SOFI systems, RDB-1-152/HCFC-141b and RDB-1-152/30% HCFC-123; 70 % HCFC-141b.

  4. Effect of forebody tangential slot blowing on flow about a full aircraft geometry

    NASA Technical Reports Server (NTRS)

    Gee, Ken; Rizk, Yehia M.; Schiff, Lewis B.

    1993-01-01

    The effect of forebody tangential slot blowing on the flowfield about an F/A-18 aircraft is investigated numerically using solutions of the Navier-Stokes equations. Computed solutions are obtained for a full aircraft geometry, including the fuselage, wing with deflected leading-edge flap, empennage, and a faired-over engine inlet. The computational slot geometry corresponds to that used in full-scale wind tunnel tests. Solutions are computed using flight test conditions and jet mass flow ratios equivalent to wind tunnel test conditions. The effect of slot location is analyzed by computing two non-time-accurate solutions with a 16 in. slot located 3 in. and 11 in. aft of the nose of the aircraft. These computations resolve the trends observed in the full-scale wind tunnel test data. The flow aft of the leading edge extension (LEX) vortex burst is unsteady. A time-accurate solution is obtained to investigate the flow characteristics aft of the vortex burst, including the effect of blowing on tail buffet.

  5. Blow-out fractures of the orbit: a comparison of computed tomography and conventional radiography with anatomic correlation

    SciTech Connect

    Hammeschlag, S.B.; Hughes, S.; O'Reilly, G.V.; Naheedy, M.H.; Rumbaugh, C.L.

    1982-05-01

    Orbital blow-out fractures were experimentally created in eight human cadavers. Each orbit underwent conventional radiographic studies, complex motion tomography, and computed tomographic examinations. A comparison of the three modalities was made. Anatomical correlation was obtained by dissecting the orbits. The significance of medial-wall fractures and enophthalmos is discussed. Limitation of inferior rectus muscle mobility is thought to be a result of muscle kinking associated with orbital fat-pad prolapse at the fracture site, rather than muscle incarceration. Blow-out fractures should be evaluated by computed tomographic computer reformations in the oblique sagittal plane.

  6. Effects of spanwise blowing on the pressure field and vortex-lift characteristics of a 44 deg swept trapezoidal wing. [wind tunnel stability tests - aircraft models

    NASA Technical Reports Server (NTRS)

    Campbell, J. F.

    1975-01-01

    Wind-tunnel data were obtained at a free-stream Mach number of 0.26 for a range of model angle of attack, jet thrust coefficient, and jet location. Results of this study show that the sectional effects to spanwise blowing are strongly dependent on angle of attack, jet thrust coefficient, and span location; the largest effects occur at the highest angles of attack and thrust coefficients and on the inboard portion of the wing. Full vortex lift was achieved at the inboard span station with a small blowing rate, but successively higher blowing rates were necessary to achieve full vortex lift at increased span distances. It is shown that spanwise blowing increases lift throughout the angle-of-attack range, delays wing stall to higher angles of attack, and improves the induced-drag polars. The leading-edge suction analogy can be used to estimate the section and total lifts resulting from spanwise blowing.

  7. Analytical models for flow control in subsonic and supersonic diffusing flow paths using steady blowing and suction

    NASA Astrophysics Data System (ADS)

    Sarimurat, Mehmet Nasir

    Flow blowing/suction has multiple beneficial effects on the performance of axial flow compressors. In both low speed and high speed compressors a small amount of flow blowing and/or suction can be applied in the region of adverse pressure gradient to control the boundary layer separation and obtain high pressure ratio across the compressor. On the other hand in high speed compressors where a passage shock is present inside the passage, flow blowing/suction can also be used to manage the shock location inside the passage and increase the operating range of the compressor. In the first part of this study, an analytical model based on the integral method for boundary layer with flow blowing in incompressible flows is developed that shows the effect of mass, momentum, velocity magnitude and injection angle of the blowing flow on the behavior of the boundary layer. According to the model the change in the boundary layer momentum thickness across the blowing location is linear function of the momentum of the blowing flow and exponential function of the velocity of the blowing flow. Also if the size of the blowing slot and the velocity of the blown flow are kept constant, when the amount of the blown flow is increased by increasing the blowing angle, there is an "optimum" angle that maximizes the decrease in the momentum thickness across the blowing station. This angle is a function of the velocity ratio and it reaches an asymptotic value of around 40°. The model also shows that the change in the trailing-edge momentum thickness is an exponential function of the change in the momentum thickness across the blowing location. The developed modeled is confirmed for the NACA-65-410 low speed cascade using Computational Fluid Dynamics and a good agreement between the theory and CFD is obtained. In the second part of the thesis a quasi-1D inviscid and compressible flow theory in a converging/diverging flow passage is presented that can predict the amount of flow blowing or

  8. Evaluating Whole Chemical Mixtures and Sufficient Similarity

    EPA Science Inventory

    This powerpoint presentation supports apresentation describing dose-response assessment for complex chemical mixtures including deriving reference doses for mixtures evaluating sufficient similarity among chemical mixtures.

  9. Bromine release from blowing snow and its impact on tropospheric chemistry

    NASA Astrophysics Data System (ADS)

    Griffiths, Paul; Yang, Xin; Abraham, N. Luke; Archibald, Alexander; Pyle, John

    2016-04-01

    In the last two decades, significant depletion of boundary layer ozone (ozone depletion events, ODEs) has been observed in both Arctic and Antarctic spring. ODEs are attributed to catalytic destruction by bromine radicals (Br plus BrO), especially during bromine explosion events (BEs), when high concentrations of BrO periodically occur. The source of bromine and the mechanism that sustains the high BrO levels are still the subject of study. Recent work by Pratt et al. (2013) posits Br2 production within saline snow and sea ice which leads to sudden ODEs. Previously, Yang et al. (2008) suggested snow could provide a source of (depleted) sea-salt aerosol if wicked from the surface of ice. They suggest that rapid depletion of bromide from the aerosol will constitute a source of photochemical Bry. Given the large sea ice extent in polar regions, this may constitute a significant source of sea salt and bromine in the polar lower atmosphere. While bromine release from blowing snow is perhaps less likely to trigger sudden ODEs, it may make a contribution to regional scale processes affecting ozone levels. Currently, the model parameterisations of Yang et al. assumes that rapid release of bromine occurs from fresh snow on sea ice during periods of strong wind. The parameterisation depends on an assumed sea-salt aerosol distribution generated via sublimation of the snow above the boundary layer, as well as taking into account the salinity of the snow. In this work, we draw on recent measurements by scientists from the British Antarctic Survey during a cruise aboard the Polarstern in the southern oceans. This has provided an extensive set of measurements of the chemical and physical characteristics of blowing snow over sea ice, and of the aerosol associated with it. Based on the observations, we have developed an improved parameterisation of the release of bromine from blowing snow. The paper presents results from the simulation performed using the United Kingdom Chemistry

  10. Establishment of developmental charts for the larvae of the blow fly Calliphora vicina using quantile regression.

    PubMed

    Baqué, Michèle; Filmann, Natalie; Verhoff, Marcel A; Amendt, Jens

    2015-03-01

    Developmental data of necrophagous blow fly species can be used to estimate a minimum postmortem interval (PMImin) in death investigations by estimating the age of larvae sampled from the cadaver. The most important parameter used in this age estimation is the increase in larval length during growth. Larval length can be compared to species-specific reference data to get an age estimate for the larval specimen. The exploration of this type of data and the use of an appropriate statistical method are the major challenges in evaluating forensic entomological data sets. In Europe, Calliphora vicina is one of the most dominant species with forensic entomological relevance. Despite its frequency and importance, there are currently no published developmental studies for German populations of this blow fly that can be referenced for larval age estimations. This is regrettable because the geographical origin of different populations may lead to phenotypic plasticity in the same species and population-specific growth patterns that differ from published data sets. To address this shortcoming, the objective of the present research was to generate growth data for C. vicina which can be used for age estimation in German casework. We present, for the first time, local developmental data for the larval stages of German C. vicina, reared at three constant temperatures (15, 20 and 25°C) and compare the results with published studies on C. vicina development from elsewhere. To analyse the development we chose a quantile mixed effects model because of its robustness and insensitivity towards outliers. Quantile regression was developed as an extension of the linear model to estimate rates of change in all parts of the distribution of a response variable and to discover more useful predictive relationships between variables. By applying a linear quantile mixed effect model, we estimated the 0.1 and 0.9 quantile functions of the larval age for each temperature. Graphically, these

  11. Low-speed stability and control wind-tunnel investigations of effects of spanwise blowing on fighter flight characteristics at high angles of attack. [Langely 12-ft low-speed tunnel and 30- by 60-ft tunnel

    NASA Technical Reports Server (NTRS)

    Satran, D. R.; Gilbert, W. P.; Anglin, E. L.

    1985-01-01

    The effects of spanwise blowing on two configurations representative of current fighter airplanes were investigated. The two configurations differed only in wing planform, with one incorporating a trapezoidal wing and the other a 60 delta wing. Emphasis was on determining the lateral-directional characteristics, particularly in the stall/departure angle-of-attack range; however, the effects of spanwise blowing on the longitudinal aerodynamics were also determined. The-tunnel tests included measurement of static force and forced-oscillation aerodynamic data, visualization of the airflow changes created by the spanwise blowing, and free-flight model tests. The effects of blowing rate, chordwise location of the blowing ports, asymmetric blowing, and blowing on the conventional aerodynamic control characteristics were investigated. In the angle-of-attack regions in which the spanwise blowing substantially improved the wing upper-surface flow field (i.e., provided reattachment of the flow aft of the leading-edge vortex), improvements in both static and dynamic lateral-directional stability were observed. Blowing effects on stability could be proverse or adverse depending on blowing rate, blowing port loaction, and wing planform. Free-flight model tests of the trapezoidal wing confirmed the beneficial effects of spanwise blowing measured in the static and dynamic force tests.

  12. In vitro antimicrobial activity of solution blow spun poly(lactic acid)/ polyvinylpyrrolidone nanofibers loaded with Copaiba (Copaifera sp.) oil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this study poly(lactic acid)(PLA) and polyvinylpyrrolidone (PVP) micro and nanofibers mats loaded with copaiba (Copaifera sp.) oil were produced by solution blow spinning (SBS). The copaiba (Copaifera sp.) oil was characterized by gas chromatography (GC). Neat PLA and four PLA/ PVP blends contain...

  13. "The Mighty, Blowing Wind Always Rests in Ethereal Space": The Role of Teachers in New Learning Paradigms

    ERIC Educational Resources Information Center

    Kumar, Muthu

    2007-01-01

    In this paper, we explore the possibilities of applying the "mighty, blowing wind resting in ethereal space" metaphor explicated in the ancient Indian philosophical treatise of "Bhagavad Gita" as an analogical representation of the functional characteristics of new pedagogies. Of pertinent attributional focus is the analysis of the complexities…

  14. Whistle-blowing and workplace culture in older peoples' care: qualitative insights from the healthcare and social care workforce.

    PubMed

    Jones, Aled; Kelly, Daniel

    2014-09-01

    Inquiries in the UK into mistreatment of older people by healthcare employees over the last 30 years have focused on introducing or supporting employee whistle-blowing. Although whistle-blowers have made an important contribution to patient safety it remains a controversial activity. The fate of whistle-blowers is bleak, often resulting in personal and professional sacrifices. Here we draw on the views of healthcare and social care employees working with older people to explore perceptions of whistle-blowing as well as alternative strategies that may be used to raise concerns about the mistreatment of patients by co-workers. Whistle-blowing was perceived as a negative term. Managers said they promoted open cultures underpinned by regular team meetings and an open-door ethos. Others described workplace norms that were somewhat at odds with these open culture ideals. Whistle-blowing was considered risky, and this led to staff creating informal channels through which to raise concerns. Those who witnessed wrongdoing were aware that support was available from external agencies but preferred local solutions and drew upon personal ethics rather than regulatory edicts to shape their responses. We argue that the importance of workplace relationships and informal channels for raising concerns should be better understood to help prevent the mistreatment of vulnerable groups.

  15. DNS on control of laminar-turbulent transition in a channel flow with a periodic suction and blowing

    NASA Astrophysics Data System (ADS)

    Yamamoto, Kiyoshi; Murase, Takeo; Floryan, J. M.

    Numerical simulation of laminar-turbulent transition in a channel flow with a spatially periodic suction/blowing on the channel walls is conducted with a spectral method based on the Fourier spectral method. The Reynolds number is fixed on a subcritical value of 5000 and the influence of both amplitude and wave number of the suction/blowing on the transition is investigated. When the amplitude is small, the transition does not occur because the suction/blowing has only a slight effect to the basic flow and the resulting flow remains stable to all 3D small disturbances. On the other hand, when the amplitude has a large value the transition occurs in a finite time and is obtained instantaneously with a huge value of the amplitude. It is found that the suction/blowing makes the separation ridges on the wall, perhaps simulating the wall roughness. The transition times are obtained for moderately large amplitudes and wave numbers and they show nearly a -2 power law dependence of the ratio of amplitude to wave number.

  16. Production of three-dimensional, spatially stimulated disturbance waves by periodic blowing and suction in a plate boundary layer flow

    NASA Astrophysics Data System (ADS)

    Konzelmann, U.; Rist, U.; Fasel, H.

    An attempt has been made to study disturbance waves by numerically simulating temporally periodic blowing and suction through a hole in a plate. Modified mixed spectral and difference methods were used, and the resulting vortex strength components are shown. With a few modifications, the procedure can be used for realistic simulation of active boundary layer influences.

  17. Global existence and blow-up for weakly coupled degenerate and singular parabolic equations with localized source

    NASA Astrophysics Data System (ADS)

    Zhou, Jun; Mu, Chunlai

    2011-02-01

    This paper deals with the following weakly coupled degenerate and singular parabolic equations with localized source u_t-(x^α u_x)_x=u^m(x_0(t),t)v^n(x_0(t),t),quad v_t-(x^β v_x)_x=v^p(x_0(t),t)u^q(x_0(t),t) in (0, a) × (0, T) with homogeneous Dirichlet boundary conditions, where {x_0(t):{R}^+→(0,a)} is Hölder continuous. T ≤ ∞, a > 0 be constants, m, n, p, q are positive real numbers and {α,βin[0,2)}. The existence of a unique classical non-negative solution is established and the sufficient conditions for the solution that exists globally or blows up in finite time are obtained. Furthermore, under certain conditions, it is proved that the blow-up set of the blowing-up solution is any closed subset of the interval (0, a). Furthermore, we also obtain the blow-up rate under the condition α = β.

  18. Development of the Variable Atmosphere Testing Facility for Blow-Down Analysis of the Mars Hopper Prototype

    SciTech Connect

    Nathan D. Jerred; Robert C. O'Brien; Steven D. Howe; James E. O'Brien

    2013-02-01

    Recent developments at the Center for Space Nuclear Research (CSNR) on a Martian exploration probe have lead to the assembly of a multi-functional variable atmosphere testing facility (VATF). The VATF has been assembled to perform transient blow-down analysis of a radioisotope thermal rocket (RTR) concept that has been proposed for the Mars Hopper; a long-lived, long-ranged mobile platform for the Martian surface. This study discusses the current state of the VATF as well as recent blow-down testing performed on a laboratory-scale prototype of the Mars Hopper. The VATF allows for the simulation of Mars ambient conditions within the pressure vessel as well as to safely perform blow-down tests through the prototype using CO2 gas; the proposed propellant for the Mars Hopper. Empirical data gathered will lead to a better understanding of CO2 behavior and will provide validation of simulation models. Additionally, the potential of the VATF to test varying propulsion system designs has been recognized. In addition to being able to simulate varying atmospheres and blow-down gases for the RTR, it can be fitted to perform high temperature hydrogen testing of fuel elements for nuclear thermal propulsion.

  19. Effect of solvent on the physical and morphological properties of poly(lactic acid) nanofibers obtained by solution blow spinning

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Solution blow spinning (SBS) is a simple, safe, and inexpensive alternative to electrospinning for making nanofibers from polymer solutions. However, since SBS is a relatively new technique, there is a general lack of information on polymer solutions and properties that affect fiber morphology and i...

  20. Parent Involvement.

    ERIC Educational Resources Information Center

    LaCrosse, Ed

    The paper discusses the rationale and guidelines for parent involvement in HCEEP (Handicapped Children's Early Education Program) projects. Ways of assessing parents' needs are reviewed, as are four types of services to meet the identified needs: parent education, direct participation, parent counseling, and parent provided programs. Materials and…

  1. Reproductive Organ of Blow Fly, Chrysomya megacephala (Diptera: Calliphoridae): Ultrastructural of Testis

    PubMed Central

    Sukontason, Kabkaew L.; Chaiwong, Tarinee; Chaisri, Urai; Kurahashi, Hiromu; Sanford, Michelle; Sukontason, Kom

    2011-01-01

    This work presents the ultrastructure of testis of the medically important blow fly, Chrysomya megacephala (Fabricius) (Diptera: Calliphoridae) using light microscopy and electron microscopy. Reproductive organ of males was dissected to determine the testis in the pupal stage, 3-day-old flies and 7-day-old flies and observed under scanning electron microscopy (SEM) and transmission electron microscopy (TEM). SEM displayed a smooth surface which is occasionally penetrated by tracheoles. TEM of the testis in the pupal stage presents the thick testis wall covering underdeveloped cells containing a variable size of an electron-dense globule. For the 3-day-old males, the testicular wall is formed by an external layer, a peritoneal sheath, a muscular layer, a basement membrane, and a follicular epithelium. Follicular epithelium presented developing spermatozoa. Regarding the 7-day-old males, development of spermatozoa is apparent, displaying nucleus, centriolar adjunct, axoneme, and mitochondrial derivatives, with the 9 + 9 + 2 microtubule pattern of axoneme. PMID:21845212

  2. Morphology and Developmental Rate of the Blow Fly, Hemipyrellia ligurriens (Diptera: Calliphoridae): Forensic Entomology Applications

    PubMed Central

    Bunchu, Nophawan; Thaipakdee, Chinnapat; Vitta, Apichat; Sanit, Sangob; Sukontason, Kom; Sukontason, Kabkaew L.

    2012-01-01

    Hemipyrellia ligurriens (Diptera: Calliphoridae) is a forensically important blow fly species presented in many countries. In this study, we determined the morphology of all stages and the developmental rate of H. ligurriens reared under natural ambient conditions in Phitsanulok province, northern Thailand. Morphological features of all stages based on observing under a light microscope were described and demonstrated in order to use for identification purpose. Moreover, development time in each stage was given. The developmental time of H. ligurriens to complete metamorphosis; from egg, larva, pupa to adult, took 270.71 h for 1 cycle of development. The results from this study may be useful not only for application in forensic investigation, but also for study in its biology in the future. PMID:22792441

  3. Environmental Conditions Influence Allometric Patterns in the Blow Fly, Chrysomya albiceps

    PubMed Central

    Horenstein, M Battán; Peretti, Av

    2011-01-01

    The objective of this research was to study variations in allometry of body characters in females and males of two populations of blow flies, Chrysomya albiceps (Wiedemann) (Diptera: Calliphoridae), under different environmental conditions to establish patterns of morphological variation. Body size of both males and females in the experimental population was significantly higher than in the individuals of the natural population, indicating an important influence of food on body size. All genitalic and non-genitalic characters in males and females of the two populations showed a trend towards negative allometry rather than isometry. Allometric patterns were modified in both sexes and between populations. The data show generally larger allometric slopes in females than in males. We confirmed that the environmental conditions have an important effect on allometric patterns and body size. PMID:22224467

  4. Flap survey test of a combined surface blowing model: Flow measurements at static flow conditions

    NASA Technical Reports Server (NTRS)

    Fukushima, T.

    1978-01-01

    The Combined Surface Blowing (CSB) V/STOL lift/propulsion system consists of a blown flap system which deflects the exhaust from a turbojet engine over a system of flaps deployed at the trailing edge of the wing. Flow measurements consisting of velocity measurements using split film probes and total measure surveys using a miniature Kiel probe were made at control stations along the flap systems at two spanwise stations, the centerline of the nozzle and 60 percent of the nozzle span outboard of the centerline. Surface pressure measurements were made in the wing cove and the upper surface of the first flap element. The test showed a significant flow separation in the wing cove. The extent of the separation is so large that the flow into the first flap takes place only at the leading edge of the flap. The velocity profile measurements indicate that large spanwise (3 dimensional) flow may exist.

  5. Self Induced Buoyant Blow Off in Upward Flame Spread on Thin Solid Fuels

    NASA Technical Reports Server (NTRS)

    Johnston, Michael C.; T'ien, James S.; Muff, Derek E.; Olson, Sandra L.; Ferkul, Paul V.

    2013-01-01

    Upward flame spread experiments were conducted on a thin fabric cloth consisting of 75% cotton and 25% fiberglass. The sample is sandwiched symmetrically with stainless steel plates with the exposed width varying between 2 to 8.8 cm from test to test and >1.5m tall. The bottom edge was ignited resulting in a symmetric two sided flame. For the narrower samples (. 5cm), two sided flame growth would proceed until reaching some limiting value (15-30 cm depending on sample width). Fluctuation or instability of the flame base on one side would initially become visible and then the flame base would retreat downstream and cause extinguishment on one side. Detailed examination of the still images shows that the fuel continues to vaporize from the extinguished side due to the thermally thin nature of the fuel. But, due to the remaining inert fiberglass mesh, which acts as a flashback arrestor, the extinguished side was not able to be reignited by the remaining flame. The remaining flame would then shrink in length due to the reduced heat transfer to the solid to a shorter length. The one-sided flame will spread stably with a constant speed and a constant flame length to the end of the sample. A constant length flame implies that the pyrolysis front and the burnt out fronts move at the same speed. For the wider samples (. 7cm), no one-sided extinction is observed. Two-sided flames spread all the way to the top of the sample. For these wider widths, the flames are still growing and have not reached their limiting length if it exists. Care was taken to minimize the amount of non-symmetries in the experimental configuration. Repeated tests show that blow-off can occur on either side of the sample. The flame growth is observed to be very symmetric during the growth phase and grew to significant length (>10cm) before extinction of the flame on one side. Our proposed explanation of this unusual phenomenon (i.e. stronger two ]sided flame cannot exist but weaker one-sided flame can

  6. Development of CFD Software To Support the Engineering of Lost Foam Pattern Blowing and Steaming

    SciTech Connect

    Dr. Kenneth A. Williams; Dr. Dale M. Snider

    2003-02-04

    This CFD Project has led to a new commercial software package (Arena-flow-eps) for advanced engineering of lost foam pattern formation. Specifically, the new software models all fluid/particle/thermal phenomena during both the bead-blowing and the pattern-fusing cycles--within a single, integrated computational tool. Engineering analysis with Arena-flow-eps will enable foundries to now obtain desirable foam pattern characteristics in a reliable (consistent) manner, aided by an understanding of the fundamental fluid/thermal physics of the process. This will lead to significant reductions in casting scrap and energy usage, as well as enable future castings to satisfy stringent requirements on high-power-density and low-emissions in tomorrow's automotive and watercraft engines.

  7. Effect of polymer/clay composition on processability of polylactide nanocomposites by film blowing

    NASA Astrophysics Data System (ADS)

    Garofalo, E.; Galdi, M. R.; D'Arienzo, L.; Di Maio, L.; Incarnato, L.

    2015-12-01

    The blown extrusion of poly(lactic acid) presents several challenges mainly due to its poor elongation properties. This work deals on the possibility to enhance the processabiliy of PLA by film blowing by functionalizing the polymer with nanosilicates. In particular, two types of polylactic acid (PLA 4032D and PLA 4042D) and different types of filler, selected from montmorillonites (Cloisite 30B) and bentonites (Nanofil SE3010) families, were used to prepare the hybrid systems by using a twin-screw extruder. The interaction between the polymer and the clay was evaluated by FTIR analysis and correlated to the structure of the obtained nanocomposites in terms of clay dispersion. All the samples were then submitted to rheological measurements both in shear and elongational mode.

  8. Laser Blow-Off Impurity Injection Experiments at the HSX Stellarator

    NASA Astrophysics Data System (ADS)

    Clark, C.; Anderson, D. T.; Anderson, F. S. B.; Likin, K. M.; Talmadge, J. N.; Zhai, K.; Lore, J.

    2011-10-01

    Experiments are under way to measure impurity transport in a quasisymmetric stellarator for the first time. A laser blow-off impurity injection system, which is capable of rapidly depositing a small, controlled quantity of a wide variety of solid impurities into the confinement volume, has been installed and successfully tested. AXUV photodiode arrays equipped with optional soft x-ray filters have also been installed on the machine. The arrays will take time-resolved measurements of the impurity radiation, which will be inverted into radial profile and then interpreted using the transport code, STRAHL and atomic data from ADAS to determine the transport coefficients within the paradigm of a diffusivity and convective velocity. Details of the system and first results will be presented along with PENTA calculations of the neoclassical predicted impurity transport Work supported by US DOE contracts DE-FG02-01ER54615 and DE-FG02-93ER54222.

  9. Pressure dependence of jet noise and silencing of blow-offs

    NASA Astrophysics Data System (ADS)

    Maa, D.-Y.; Li, P.-Z.

    1981-12-01

    Improvements in methods of jet noise prediction and reduction are discussed. Measurements were performed on a cold-air jet exiting through convergent nozzles of varying diameters, and on superheated jet streams at an oil refinery. A critical value was determined for the stagnation pressure, beyond which the jet becomes choked and shock-cell noise occurs along with turbulent noise. The turbulent noise was isolated by making the lip of the jet irregular, then measuring the A-weighted sound level. Blow-down studies were also made of the shock-cell noise, which was found to happen above the frequency peak of the turbulent noise. The interaction of microjets grouped together is considered, noting that a form of the Coanda effect causes the formation of a single jet. A micropore muffler is presented, which consists of a pipe drilled with many holes, and a diffuse-muffler is mentioned, which contains randomly distributed holes internally to dampen the noise emission.

  10. Advances in Pneumatic-Controlled High-Lift Systems Through Pulsed Blowing

    NASA Technical Reports Server (NTRS)

    Jones, Gregory S.; Englar, Robet J.

    2003-01-01

    Circulation Control technologies have been around for 65 years, and have been successfully demonstrated in laboratories and flight vehicles alike. Yet there are few production aircraft flying today that implement these advances. Circulation Control techniques may have been overlooked due to perceived unfavorable trade offs of mass flow, pitching moment, cruise drag, noise, etc. Improvements in certain aspects of Circulation Control technology are the focus of this paper. This report will describe airfoil and blown high lift concepts that also address cruise drag reduction and reductions in mass flow through the use of pulsed pneumatic blowing on a Coanda surface. Pulsed concepts demonstrate significant reductions in mass flow requirements for Circulation Control, as well as cruise drag concepts that equal or exceed conventional airfoil systems.

  11. Top-blowing, bottom-stirring process for producing blister copper

    NASA Astrophysics Data System (ADS)

    Marcuson, Samuel W.; Díaz, Carlos; Davies, Haydn

    1994-08-01

    An oxygen top-blowing, nitrogen bottom-stirring process to convert semiblister (i.e., sulfur-saturated, nickel-contaminated copper), to low-sulfur and low-nickel blister has been developed by Inco. This process is complemented by a technique, also newly developed, for washing out residual nickel-copper oxide mush from the converter after casting the blister copper. Following laboratory and pilot-plant testing, this technology graduated to the smelter floor where it is now a key component of the new Copper Cliff Smelter flow sheet. Existing Peirce-Smith converters have been adapted to practice the new process. The modified vessels are equipped with porous plugs, the first application of this type of refractory in copper smelting.

  12. Toxicological approaches to complex mixtures.

    PubMed Central

    Mauderly, J L

    1993-01-01

    This paper reviews the role of toxicological studies in understanding the health effects of environmental exposures to mixtures. The approach taken is to review mixtures that have received the greatest emphasis from toxicology; major mixtures research programs; the toxicologist's view of mixtures and approaches to their study; and the complementary roles of toxicological, clinical, and epidemiological studies. Studies of tobacco smoke, engine exhaust, combustion products, and air pollutants comprise most of the past research on mixtures. Because of their great experimental control over subjects, exposures, and endpoints, toxicologists tend to consider a wider range of toxic interactions among mixture components and sequential exposures than is practical for human studies. The three fundamental experimental approaches used by toxicologists are integrative (studying the mixture as a whole), dissective (dissecting a mixture to determine causative constituents), and synthetic (studying interactions between agents in simple combinations). Toxicology provides information on potential hazards, mechanisms by which mixture constituents interact to cause effects, and exposure dose-effect relationships; but extrapolation from laboratory data to quantitative human health risks is problematic. Toxicological, clinical, and epidemiological approaches are complementary but are seldom coordinated. Fostering synergistic interactions among the disciplines in studying the risks from mixtures could be advantageous. PMID:7515806

  13. Toxicological approaches to complex mixtures.

    PubMed

    Mauderly, J L

    1993-12-01

    This paper reviews the role of toxicological studies in understanding the health effects of environmental exposures to mixtures. The approach taken is to review mixtures that have received the greatest emphasis from toxicology; major mixtures research programs; the toxicologist's view of mixtures and approaches to their study; and the complementary roles of toxicological, clinical, and epidemiological studies. Studies of tobacco smoke, engine exhaust, combustion products, and air pollutants comprise most of the past research on mixtures. Because of their great experimental control over subjects, exposures, and endpoints, toxicologists tend to consider a wider range of toxic interactions among mixture components and sequential exposures than is practical for human studies. The three fundamental experimental approaches used by toxicologists are integrative (studying the mixture as a whole), dissective (dissecting a mixture to determine causative constituents), and synthetic (studying interactions between agents in simple combinations). Toxicology provides information on potential hazards, mechanisms by which mixture constituents interact to cause effects, and exposure dose-effect relationships; but extrapolation from laboratory data to quantitative human health risks is problematic. Toxicological, clinical, and epidemiological approaches are complementary but are seldom coordinated. Fostering synergistic interactions among the disciplines in studying the risks from mixtures could be advantageous.

  14. Stabilizer for fuel mixtures

    SciTech Connect

    Abe, M.; Moriyama, N.; Yamamura, M.

    1981-02-24

    A stabilizer for fuel mixtures of finely divided coal and fuel oil is composed of an active ingredient, a non-ionic surface active agent consisting of a block copolymer represented by the following general formula (I): R/sub 1/O-(C/sub 2/H/sup 4/O)l-(C/sub 3/H/sup 6/O)m-(C/sub 2/H/sup 4/O)n-R/sub 2/ (I) wherein r/sub 1/ and r/sub 2/ stand for a hydrogen atom or an alklyl group having 1 to 6 carbon atoms, the mole number (L+n) of added ethylene oxide is in the range of from 30 to 300, the mole number (M) of added propylene oxide is in the range of from 15 to 80, and the content of ethylene oxide in the whole molecule is 40 to 85% by weight.

  15. Dried distillers grains with solubles do not always cause late blowing in baby Swiss cheese.

    PubMed

    Sankarlal, V Manimanna; Testroet, E D; Beitz, D C; Clark, S

    2015-12-01

    Late blowing in Swiss cheese, a result of unwanted gas production, is unacceptable to consumers and causes economic loss to manufacturers. Cheese processors have raised concerns that feeding dried distillers grains with solubles (DDGS) to cows leads to this defect, in part because of clostridial spores. We hypothesized that spores in DDGS would affect the quality of milk and baby Swiss cheese by promoting late-blowing defects. Thirty healthy multiparous and mid-lactation Holstein cows were fed total mixed ration containing DDGS (0, 10, and 20%; 10 cows per treatment group) by dietary dry matter in a 3×3 Latin square design. One complete milking from all cows within a treatment was collected and pooled for baby Swiss cheese, twice within each month of the 3-mo study. Additionally, individual milk samples from the 3 milkings of one day were collected weekly for proximate analysis. Incubation in reinforced clostridial medium-lactate medium tubes inoculated with milk, cheese, total mixed ration, or manure showed gas formation. Conversely, the DDGS used in our study did not contain gas-producing, spore-forming bacteria. Feeding 20% DDGS decreased milk fat percent and increased the solids nonfat, protein, and lactose percent of milk. After 60 d of ripening, baby Swiss cheese had typical propionic acid Swiss cheese aroma. Regardless of dietary treatment, pinholes, slits, splits, cracks, or a combination of these, were seen throughout most cheeses. Feeding of DDGS increased the amount of long-chain unsaturated fatty acids and decreased short-chain and most medium-chain fatty acids in the baby Swiss cheese. Although feeding cows diets with DDGS modified milk composition, and subsequently cheese composition, DDGS was not a source for gas-producing, spore-forming bacteria or for quality defects in Swiss cheese. Rather, the gas-producing, spore-forming bacteria likely originated from the environment or the cows themselves.

  16. Simulative design and process optimization of the two-stage stretch-blow molding process

    SciTech Connect

    Hopmann, Ch.; Rasche, S.; Windeck, C.

    2015-05-22

    The total production costs of PET bottles are significantly affected by the costs of raw material. Approximately 70 % of the total costs are spent for the raw material. Therefore, stretch-blow molding industry intends to reduce the total production costs by an optimized material efficiency. However, there is often a trade-off between an optimized material efficiency and required product properties. Due to a multitude of complex boundary conditions, the design process of new stretch-blow molded products is still a challenging task and is often based on empirical knowledge. Application of current CAE-tools supports the design process by reducing development time and costs. This paper describes an approach to determine optimized preform geometry and corresponding process parameters iteratively. The wall thickness distribution and the local stretch ratios of the blown bottle are calculated in a three-dimensional process simulation. Thereby, the wall thickness distribution is correlated with an objective function and preform geometry as well as process parameters are varied by an optimization algorithm. Taking into account the correlation between material usage, process history and resulting product properties, integrative coupled simulation steps, e.g. structural analyses or barrier simulations, are performed. The approach is applied on a 0.5 liter PET bottle of Krones AG, Neutraubling, Germany. The investigations point out that the design process can be supported by applying this simulative optimization approach. In an optimization study the total bottle weight is reduced from 18.5 g to 15.5 g. The validation of the computed results is in progress.

  17. Novel Anionic Clay Adsorbents for Boiler-Blow Down Waters Reclaim and Reuse

    SciTech Connect

    Muhammad Sahimi; Theodore T. Tsotsis

    2005-12-01

    Our goal in this study is to utilize novel anionic clay sorbents for treating and reclaiming/reusing power-plant effluents, in particular, boiler blow-down waters containing heavy metals, such as As and Se. Developing and using novel materials for such application is dictated by the challenge posed by reclaiming and recycling these too-clean-to-clean effluent streams, generated during electricity production, whose contaminant levels are in the ppm/ppb (or even less) trace levels. During the study model blow-down streams have been treated in batch experiments. Adsorption isotherms as a function of pH/temperature have been established for both As and Se. Adsorption rates have also measured as a function of concentration, temperature, pH, and space time. For both the equilibrium and rate measurements, we have studied the As/Se interaction, and competition from background anions. A homogeneous surface diffusion model is used to describe the experimental kinetic data. The estimated diffusivity values are shown to depend on the particle size. On the other hand, a model taking into account the polycrystalline nature of these adsorbent particles, and the presence of an intercrystallite porous region predicts correctly that the surface diffusivity is particle size independent. A mathematical model to describe flow experiments in packed-beds has also been developed during phase I of this project. The goal is to validate this model with flow experiments in packed-beds during the phase II of this project, to determine the adsorption capacity under flow conditions, and to compare it with the capacity estimated from the adsorption isotherms determined from the batch studies.

  18. Development and Qualification of Alternate Blowing Agents for Space Shuttle External Tank Thermal Protection System

    NASA Technical Reports Server (NTRS)

    Williams, Charles W.; Cavalaris, James G.

    1994-01-01

    The Aerospace industry has a long history of using low density polyurethane and polyurethane-modified isocyanurate foam systems as lightweight, low cost, easily processed cryogenic Thermal Protection Systems (TPS) for ascent vehicles. The Thermal Protection System of the Space Shuttle External Tank (ET) is required so that quality liquid cryogenic propellant can be supplied to the Orbiter main engines and to protect the metal structure of the tanks from becoming too hot from aerodynamic heating, hence preventing premature break-up of the tank. These foams are all blown with CFC-1 I blowing agent which has been identified by the Environmental Protection Agency (EPA) as an ozone depleting substance. CFCs will not be manufactured after 1995, Consequently, alternate blowing agent substances must be identified and implemented to assure continued ET manufacture and delivery. This paper describes the various testing performed to select and qualify HCFC-1 41 b as a near term drop-in replacement for CFC-11. Although originally intended to be a one for one substitution in the formulation, several technical issues were identified regarding material performance and processability which required both formulation changes and special processing considerations to overcome. In order to evaluate these material changes, each material was subjected to various tests to qualify them to meet the various loads imposed on them during long term storage, pre-launch operations, launch, separation and re-entry. Each material was tested for structural, thermal, aeroshear, and stress/strain loads for the various flight environments each encounters. Details of the development and qualification program and the resolution of specific problems are discussed in this paper.

  19. Pneumatic colon injury following high pressure blow gun dust cleaner spray to the perineum

    PubMed Central

    Sy, Edgar D.; Chiu, Yin-I.; Shan, Yan-Shen; Ong, Roger L.

    2014-01-01

    Introduction A pneumatic tool or air tool such as blow gun dust cleaner is a tool driven by compressed air and spraying of the perineum can insufflate the colon due to its high pressure and high flow rate. Presentation of case We present a case of 4 year old boy who developed sudden onset of tense abdominal distention and developed peritonitis. Patient’s family initially denied a history of trauma. Radiologic examination showed pneumoperitoneum and colon dilatation. Exploratory laparotomy revealed a tension pneumoperitoneum, bloody ascitic fluid, multiple site of ecchymosis and serosal tear of the colon and a minute perforation of transverse colon. Postoperative reinvestigation revealed that the patient’s perineum was sprayed, using blow gun dust cleaner. Discussion Air from pneumatic tools produces column of air at pressure of 3.5–8.8 kg/cm2 and pressure greater than the resting anal pressure of 0.109 kg/cm2 force air to enter the colon when the perineum is sprayed. Different degree of colon injury results when airflow is greater than 1.46 L/m, and/or intraluminal pressure greater than 0.109 kg/cm2. In most children, initial anxiety to tell the truth result in difficulty to obtain good history. Conclusion Spraying of the perianal with excessive pneumatic force of greater than the resting anal pressure and high air flow rate causes multiple site colon injury and tension pneumoperitoneum due to colon perforation. Parent should be caution in children playing with high pressure pneumatic tool, and the importance of history is emphases for early correct diagnosis. PMID:25544492

  20. Dried distillers grains with solubles do not always cause late blowing in baby Swiss cheese.

    PubMed

    Sankarlal, V Manimanna; Testroet, E D; Beitz, D C; Clark, S

    2015-12-01

    Late blowing in Swiss cheese, a result of unwanted gas production, is unacceptable to consumers and causes economic loss to manufacturers. Cheese processors have raised concerns that feeding dried distillers grains with solubles (DDGS) to cows leads to this defect, in part because of clostridial spores. We hypothesized that spores in DDGS would affect the quality of milk and baby Swiss cheese by promoting late-blowing defects. Thirty healthy multiparous and mid-lactation Holstein cows were fed total mixed ration containing DDGS (0, 10, and 20%; 10 cows per treatment group) by dietary dry matter in a 3×3 Latin square design. One complete milking from all cows within a treatment was collected and pooled for baby Swiss cheese, twice within each month of the 3-mo study. Additionally, individual milk samples from the 3 milkings of one day were collected weekly for proximate analysis. Incubation in reinforced clostridial medium-lactate medium tubes inoculated with milk, cheese, total mixed ration, or manure showed gas formation. Conversely, the DDGS used in our study did not contain gas-producing, spore-forming bacteria. Feeding 20% DDGS decreased milk fat percent and increased the solids nonfat, protein, and lactose percent of milk. After 60 d of ripening, baby Swiss cheese had typical propionic acid Swiss cheese aroma. Regardless of dietary treatment, pinholes, slits, splits, cracks, or a combination of these, were seen throughout most cheeses. Feeding of DDGS increased the amount of long-chain unsaturated fatty acids and decreased short-chain and most medium-chain fatty acids in the baby Swiss cheese. Although feeding cows diets with DDGS modified milk composition, and subsequently cheese composition, DDGS was not a source for gas-producing, spore-forming bacteria or for quality defects in Swiss cheese. Rather, the gas-producing, spore-forming bacteria likely originated from the environment or the cows themselves. PMID:26454296

  1. Plant terpenoids: acute toxicities and effects on flight motor activity and wing beat frequency in the blow fly Phaenicia sericata.

    PubMed

    Waliwitiya, Ranil; Belton, Peter; Nicholson, Russell A; Lowenberger, Carl A

    2012-02-01

    We evaluated the acute toxicities and the physiological effects of plant monoterpenoids (eugenol, pulegone, citronellal and alpha-terpineol) and neuroactive insecticides (malathion, dieldrin and RH3421) on flight muscle impulses (FMI) and wing beat signals (WBS) of the blow fly (Phaenicia sericata). Topically-applied eugenol, pulegone, citronellal, and alpha-terpineol produced neurotoxic symptoms, but were less toxic than malathion, dieldrin, or RH3421. Topical application of eugenol, pulegone, and citronellal reduced spike amplitude in one of the two banks of blow fly dorsolongitudinal flight muscles within 6-8 min, but with citronellal, the amplitude of FMIs reverted to a normal pattern within 1 hr. In contrast to pulegone and citronellal, where impulse frequency remained relatively constant, eugenol caused a gradual increase, then a decline in the frequency of spikes in each muscle bank. Wing beating was blocked permanently within 6-7 min of administering pulegone or citronellal and within 16 mins with eugenol. alpha-Terpineol-treated blow flies could not beat their wings despite normal FMI patterns. The actions of these monoterpenoids on blow fly flight motor patterns are discussed and compared with those of dieldrin, malathion, RH3421, and a variety of other neuroactive substances we have previously investigated in this system. Eugenol, pulegone and citronellal readily penetrate blow fly cuticle and interfere with flight muscle and/or central nervous function. Although there were differences in the effects of these compounds, they mainly depressed flight-associated responses, and acted similarly to compounds that block sodium channels and facilitate GABA action.

  2. Mixtures with relatives and linked markers.

    PubMed

    Dørum, Guro; Kling, Daniel; Tillmar, Andreas; Vigeland, Magnus Dehli; Egeland, Thore

    2016-05-01

    Mixture DNA profiles commonly appear in forensic genetics, and a large number of statistical methods and software are available for such cases. However, most of the literature concerns mixtures where the contributors are assumed unrelated and the genetic markers are unlinked. In this paper, we consider mixtures of linked markers and related contributors. If no relationships are involved, linkage can be ignored. While unlinked markers can be treated independently, linkage introduces dependencies. The use of linked markers presents statistical and computational challenges, but may also lead to a considerable increase in power since the number of markers available is much larger if we do not require the markers to be unlinked. In addition, some cases that cannot be solved with an unlimited number of unlinked autosomal markers can be solved with linked markers. We focus on two special cases of linked markers: pairs of linked autosomal markers and X-chromosomal markers. A framework is presented for calculation of likelihood ratios for mixtures with general relationships and with linkage between any number of markers. Finally, we explore the effect of linkage disequilibrium, also called allelic association, on the likelihood ratio.

  3. Use of an Amino Acid Mixture in Treatment of Phenylketonuria

    PubMed Central

    Bentovim, A.; Clayton, Barbara E.; Francis, Dorothy E. M.; Shepherd, Jean; Wolff, O. H.

    1970-01-01

    Twelve children with phenylketonuria diagnosed and treated from the first few weeks of life were grouped into pairs. Before the trial all of them were receiving a commercial preparation containing a protein hydrolysate low in phenylalanine (Cymogran, Allen and Hanburys Ltd.) as a substitute for natural protein. One of each pair was given an amino acid mixture instead of Cymogran for about 6 months. Use of the mixture involved considerable modification of the diet, and in particular the inclusion of greater amounts of phenylalanine-free foods. All six accepted the new mixture without difficulty, food problems were greatly reduced, parents welcomed the new preparation, and the quality of family life improved. Normal growth was maintained and with a mixture of l amino acids the plasma and urinary amino acid levels were normal. Further studies are needed before the mixture can be recommended for children under 20 months of age. PMID:5477678

  4. Mixture design and multivariate analysis in mixture research.

    PubMed Central

    Eide, I; Johnsen, H G

    1998-01-01

    Mixture design has been used to identify possible interactions between mutagens in a mixture. In this paper the use of mixture design in multidimensional isobolographic studies is introduced. Mutagenicity of individual nitro-polycyclic aromatic hydrocarbons (PAH) was evaluated is an organic extract of diesel exhaust particles (DEPs). The particles were extracted with dichloromethane (DCM). After replacing DCM with dimethyl sulfoxide, the extract was spiked with three individual nitro-PAH: 1-nitropyrene, 2-nitrofluorene, and 1,8-dinitropyrene. The nitro-PAH were added separately and in various combinations to the extract to determine the effects of each variable and to identify possible interactions between the individual nitro-PAH and between the nitro-PAH and the extract. The composition of the mixtures was determined by mixture design (linear axial normal) with four variables (the DEP extract and the three nitro-PAH, giving 8 different mixtures plus a triplicate centerpoint, i.e., a total of 11. The design supports a model with linear and interaction (product) terms. Two different approaches were used: traditional mixture design within a well-defined range on the linear part of the dose-response curves and an isobolographic mixture design with equipotent doses of each variable. The mixtures were tested for mutagenicity in the Ames assay using the TA98 strain of Salmonella typhimurium. The data were analyzed with projections to latent structures (PLS). The three individual nitro-PAH and the DEP extract acted additively in the Ames test. The use of mixture design either within a well-defined range of the linear part on the dose-response curve or with equipotent doses saves experiments and reduces the possibility of false interaction terms in situations with dose additivity or response additivity. Images Figure 1 Figure 2 PMID:9860895

  5. Mixture design and multivariate analysis in mixture research.

    PubMed

    Eide, I; Johnsen, H G

    1998-12-01

    Mixture design has been used to identify possible interactions between mutagens in a mixture. In this paper the use of mixture design in multidimensional isobolographic studies is introduced. Mutagenicity of individual nitro-polycyclic aromatic hydrocarbons (PAH) was evaluated is an organic extract of diesel exhaust particles (DEPs). The particles were extracted with dichloromethane (DCM). After replacing DCM with dimethyl sulfoxide, the extract was spiked with three individual nitro-PAH: 1-nitropyrene, 2-nitrofluorene, and 1,8-dinitropyrene. The nitro-PAH were added separately and in various combinations to the extract to determine the effects of each variable and to identify possible interactions between the individual nitro-PAH and between the nitro-PAH and the extract. The composition of the mixtures was determined by mixture design (linear axial normal) with four variables (the DEP extract and the three nitro-PAH, giving 8 different mixtures plus a triplicate centerpoint, i.e., a total of 11. The design supports a model with linear and interaction (product) terms. Two different approaches were used: traditional mixture design within a well-defined range on the linear part of the dose-response curves and an isobolographic mixture design with equipotent doses of each variable. The mixtures were tested for mutagenicity in the Ames assay using the TA98 strain of Salmonella typhimurium. The data were analyzed with projections to latent structures (PLS). The three individual nitro-PAH and the DEP extract acted additively in the Ames test. The use of mixture design either within a well-defined range of the linear part on the dose-response curve or with equipotent doses saves experiments and reduces the possibility of false interaction terms in situations with dose additivity or response additivity. PMID:9860895

  6. What can we expect from epidemiologic studies of chemical mixtures?

    PubMed

    Samet, J M

    1995-12-28

    Determining the health risks of complex mixtures is equally daunting to toxicologists using experimental approaches and to epidemiologists using observational approaches. Accurate exposure estimation is essential in investigating the health consequences of exposures to chemical mixtures; random and non-random errors in exposure estimation typically blunt the sensitivity of epidemiologic studies and constrain interpretation of findings. On the other hand, epidemiologic data have the implicit strength of directly addressing risks of exposures in human populations and, for this reason, the findings of epidemiologic research have received prominence in the development of regulations. Epidemiologic studies have proved informative about many complex mixtures including cigarette smoke, diesel exhaust, and even the human diet, perhaps one of the most complex mixtures to which we are exposed. The continued interest in studying complex chemical mixtures is emphasized by this and other recent meetings directed at the topic. The variety of approaches used by epidemiologists in approaching complex mixtures reflects the difficulty of exposure estimation. Five general strategies can be identified, each with differing underlying assumptions and yielding results with distinct implications from biological and public health perspectives. These include treating the mixture as though it were a single agent, using a single component as a surrogate for the mixture, creating a summary index involving multiple components, attempting to estimate independent effects of individual components, and characterizing the independent and joint effects of key components of the mixture. These approaches have proved successful in establishing the adverse effects of a number of complex chemical mixtures including mainstream and environmental tobacco smoke and outdoor air pollution. New approaches for exposure assessment, including personal monitoring and biomarkers, should strengthen future

  7. Successive laser ablation ignition of premixed methane/air mixtures.

    PubMed

    Bak, Moon Soo; Cappelli, Mark A

    2015-06-01

    Laser ablation has been used to study successive ignition in premixed methane/air mixtures under conditions in which the flow speed leads to flame blow-out. A range of laser pulse frequencies is experimentally mimicked by varying the time interval between two closely spaced laser pulses. Emission intensities from the laser ablation kernels are measured to qualitatively estimate laser energy coupling, and flame CH* chemiluminescence is recorded in a time-resolved manner to capture the flame evolution and propagation. A comparison of the measurements is made between the two successive breakdown ignition events. It is found that the formation of the subsequent ablation kernel is almost independent of the previous one, however, for the successive breakdowns, the first breakdown and its ensuing combustion created temporal regions of no energy coupling as they heat the gas and lower the density. Flame imaging shows that the second ablation event successfully produces another flame kernel and is capable of holding the flame-base even at pulse intervals where the second laser pulse cannot form a breakdown. This study demonstrates that successive ablation ignition can allow for the use of higher laser frequencies and enhanced flame stabilization than successive breakdown ignition. PMID:26072866

  8. Separation of organic azeotropic mixtures by pervaporation. Final technical report

    SciTech Connect

    Baker, R.W.

    1991-12-01

    Distillation is a commonly used separation technique in the petroleum refining and chemical processing industries. However, there are a number of potential separations involving azetropic and close-boiling organic mixtures that cannot be separated efficiently by distillation. Pervaporation is a membrane-based process that uses selective permeation through membranes to separate liquid mixtures. Because the separation process is not affected by the relative volatility of the mixture components being separated, pervaporation can be used to separate azetropes and close-boiling mixtures. Our results showed that pervaporation membranes can be used to separate azeotropic mixtures efficiently, a result that is not achievable with simple distillation. The membranes were 5--10 times more permeable to one of the components of the mixture, concentrating it in the permeate stream. For example, the membrane was 10 times more permeable to ethanol than methyl ethyl ketone, producing 60% ethanol permeate from an azeotropic mixture of ethanol and methyl ethyl ketone containing 18% ethanol. For the ethyl acetate/water mixture, the membranes showed a very high selectivity to water (> 300) and the permeate was 50--100 times enriched in water relative to the feed. The membranes had permeate fluxes on the order of 0.1--1 kg/m{sup 2}{center_dot}h in the operating range of 55--70{degrees}C. Higher fluxes were obtained by increasing the operating temperature.

  9. Thermophysical Properties of Hydrocarbon Mixtures

    National Institute of Standards and Technology Data Gateway

    SRD 4 NIST Thermophysical Properties of Hydrocarbon Mixtures (PC database for purchase)   Interactive computer program for predicting thermodynamic and transport properties of pure fluids and fluid mixtures containing up to 20 components. The components are selected from a database of 196 components, mostly hydrocarbons.

  10. Do climatic and physical factors affect populations of the blow fly Chrysomya megacephala and house fly Musca domestica?

    PubMed

    Ngoen-klan, Ratchadawan; Moophayak, Kittikhun; Klong-klaew, Tunwadee; Irvine, Kim N; Sukontason, Kabkaew L; Prangkio, Chira; Somboon, Pradya; Sukontason, Kom

    2011-11-01

    The blow fly, Chrysomya megacephala (Fabricius), and house fly, Musca domestica L., are medically and forensically important flies. The population dynamic of these flies is essential for both control and forensical aspects. The aim of this study was to investigate the climatic and physical factors affecting the population trend of both species in Chiang Mai province, northern Thailand, using the Geographic Information System (GIS). Based on systematic random sampling, 18 study sites were selected in three districts (Mueang Chiang Mai, Mae Rim, and Hang Dong). Six land use types were involved in the study sites, i.e., disturbed mixed deciduous, mixed deciduous forest, mixed orchard, lowland village, city, and paddy field. Adult flies were sampled every 2 weeks using an in-house prototype reconstructable funnel trap. Two types of bait were used--one with fresh beef viscera for luring M. domestica and the other with 1-day tainted beef viscera for luring C. megacephala. Collections were conducted from May 2009 to May 2010, and analysis of climatic factors (temperature, relative humidity, and light intensity) was carried out. Correlation bivariate analysis was performed initially to determine the relationship between climatic factors and the number of flies. Consequently, an ordinary co-kriging approach, in ArcGIS 9.2, was performed to predict the spatial distribution of flies with land use and climatic factors as co-variables. A total of 63,158 flies were captured, with C. megacephala being the most common species collected (68.37%), while only 1.3% were M. domestica, thus proving that C. megacephala was the most abundant species in several land use types. A significantly higher number of females than males was found in both species. Fly populations can be collected throughout most of the year with a peak in late summer, which shows a positive relation to temperature but negative correlation with relative humidity. C. megacephala was predicted to be abundant in every

  11. Latent classiness and other mixtures.

    PubMed

    Neale, Michael C

    2014-05-01

    The aim of this article is to laud Lindon Eaves' role in the development of mixture modeling in genetic studies. The specification of models for mixture distributions was very much in its infancy when Professor Eaves implemented it in his own FORTRAN programs, and extended it to data collected from relatives such as twins. It was his collaboration with the author of this article which led to the first implementation of mixture distribution modeling in a general-purpose structural equation modeling program, Mx, resulting in a 1996 article on linkage analysis in Behavior Genetics. Today, the popularity of these methods continues to grow, encompassing methods for genetic association, latent class analysis, growth curve mixture modeling, factor mixture modeling, regime switching, marginal maximum likelihood, genotype by environment interaction, variance component twin modeling in the absence of zygosity information, and many others. This primarily historical article concludes with some consideration of some possible future developments. PMID:24477932

  12. Increasing the arc efficiency by the removal of arc electromagnetic blowing in electric arc furnaces: I. Effect of electromagnetic blowing and the slag height on the arc efficiency in an electric arc furnace

    NASA Astrophysics Data System (ADS)

    Makarov, A. N.; Sokolov, A. Yu.; Lugovoi, Yu. A.

    2012-06-01

    The effect of electromagnetic blowing and the slag layer height on the arc efficiency is analytically studied. An arc is blown from under an electrode toward the furnace walls under an electromagnetic force. The arc efficiency of a 100-t high-power electric arc furnace changes from 0.47 to 0.76 when the slag height increases from 0 to 550 mm.

  13. Blow-up of weak solutions to a chemotaxis system under influence of an external chemoattractant

    NASA Astrophysics Data System (ADS)

    Black, Tobias

    2016-06-01

    We study nonnnegative radially symmetric solutions of the parabolic–elliptic Keller–Segel whole space system {ut=Δu‑∇ṡ(u∇v), x∈Rn,t>0,0=Δv+u+f(x), x∈Rn,t>0,u(x,0)=u0(x), x∈Rn, with prototypical external signal production f(x):={f0|x|‑α,if |x|⩽R‑ρ,0,if |x|⩾R+ρ, for R\\in (0,1) and ρ \\in ≤ft(0,\\frac{R}{2}\\right) , which is still integrable but not of class {{L}\\frac{n{2}+{δ0}}}≤ft({{{R}}n}\\right) for some {δ0}\\in ≤ft[0,1\\right) . For corresponding parabolic-parabolic Neumann-type boundary-value problems in bounded domains Ω , where f\\in {{L}\\frac{n{2}+{δ0}}}(Ω ){\\cap}{{C}α}(Ω ) for some {δ0}\\in (0,1) and α \\in (0,1) , it is known that the system does not emit blow-up solutions if the quantities \\parallel {{u}0}{{\\parallel}{{L\\frac{n{2}+{δ0}}}(Ω )}},\\parallel f{{\\parallel}{{L\\frac{n{2}+{δ0}}}(Ω )}} and \\parallel {{v}0}{{\\parallel}{{Lθ}(Ω )}} , for some θ >n , are all bounded by some \\varepsilon >0 small enough. We will show that whenever {{f}0}>\\frac{2n}α(n-2)(n-α ) and {{u}0}\\equiv {{c}0}>0 in \\overline{{{B}1}(0)} , a measure-valued global-in-time weak solution to the system above can be constructed which blows up immediately. Since these conditions are independent of R\\in (0,1) and c 0  >  0, we obtain a strong indication that in fact {δ0}=0 is critical for the existence of global bounded solutions under a smallness conditions as described above.

  14. The importance of SAR wavelength in penetrating blow sand in Northern Arizona

    USGS Publications Warehouse

    Schaber, G.G.; Breed, C.S.

    1999-01-01

    Multifrequency and polarimetric Airborne Synthetic Aperture Radar (AIRSAR) images of a sand streak in northern Arizona demonstrate the ability of C- (6-cm wavelength), L- (24 cm), and P-band (68 cm) radar signals to backscatter, respectively, from increasingly greater depths reaching 2 m or more in active blow sand. The studied sand streak, located on a salient of Ward Terrace at lat 35??48.4'N and long 111??15.0'W, is sourced in the normally dry Little Colorado River channel and migrates northeastward toward the Moenkopi Plateau Scarp. The sand streak is 'radar dark' compared to the 'radar-bright' surface of Ward Terrace on all C-band images. It is, however, penetrated completely at P-band and is invisible on these images. The sand streak is recognizable on the LHH image but is poorly defined on the LHV image. High resolution AIRSAR images constitute the primary data set analyzed; in addition, a C-band radar image acquired by the European Remote Sensing (ERS) satellite is also presented. The spaceborne image data confirms the results of the aircraft data at C-band.Multifrequency and polarimetric Airborne Synthetic Aperture Radar (AIRSAR) images of a sand streak in northern Arizona demonstrate the ability of C- (6-cm wavelength), L- (24 cm), and P-band (68 cm) radar signals to backscatter, respectively, from increasingly greater depths reaching 2 m or more in active blow sand. The studied sand streak, located on a salient of Ward Terrace at lat 35??48.4???N and long 111??15.0???W, is sourced in the normally dry Little Colorado River channel and migrates northeastward toward the Moenkopi Plateau Scarp. The sand streak is `radar dark' compared to the `radar-bright' surface of Ward Terrace on all C-band images. It is, however, penetrated completely at P-band and is invisible on these images. The sand streak is recognizable on the LHH image but is poorly defined on the LHV image. High resolution AIRSAR images constitute the primary data set analyzed; in addition, a C

  15. Blow-up of weak solutions to a chemotaxis system under influence of an external chemoattractant

    NASA Astrophysics Data System (ADS)

    Black, Tobias

    2016-06-01

    We study nonnnegative radially symmetric solutions of the parabolic-elliptic Keller-Segel whole space system {ut=Δu-∇ṡ(u∇v), x∈Rn,t>0,0=Δv+u+f(x), x∈Rn,t>0,u(x,0)=u0(x), x∈Rn, with prototypical external signal production f(x):={f0|x|-α,if |x|⩽R-ρ,0,if |x|⩾R+ρ, for R\\in (0,1) and ρ \\in ≤ft(0,\\frac{R}{2}\\right) , which is still integrable but not of class {{L}\\frac{n{2}+{δ0}}}≤ft({{{R}}n}\\right) for some {δ0}\\in ≤ft[0,1\\right) . For corresponding parabolic-parabolic Neumann-type boundary-value problems in bounded domains Ω , where f\\in {{L}\\frac{n{2}+{δ0}}}(Ω ){\\cap}{{C}α}(Ω ) for some {δ0}\\in (0,1) and α \\in (0,1) , it is known that the system does not emit blow-up solutions if the quantities \\parallel {{u}0}{{\\parallel}{{L\\frac{n{2}+{δ0}}}(Ω )}},\\parallel f{{\\parallel}{{L\\frac{n{2}+{δ0}}}(Ω )}} and \\parallel {{v}0}{{\\parallel}{{Lθ}(Ω )}} , for some θ >n , are all bounded by some \\varepsilon >0 small enough. We will show that whenever {{f}0}>\\frac{2n}α(n-2)(n-α ) and {{u}0}\\equiv {{c}0}>0 in \\overline{{{B}1}(0)} , a measure-valued global-in-time weak solution to the system above can be constructed which blows up immediately. Since these conditions are independent of R\\in (0,1) and c 0  >  0, we obtain a strong indication that in fact {δ0}=0 is critical for the existence of global bounded solutions under a smallness conditions as described above.

  16. Estimate of blow-up and relaxation time for self-gravitating Brownian particles and bacterial populations.

    PubMed

    Chavanis, P-H; Sire, C

    2004-08-01

    We determine an exact asymptotic expression of the blow-up time t(coll) for self-gravitating Brownian particles or bacterial populations (chemotaxis) close to the critical point in d=3. We show that t(coll) = t(*) (eta- eta(c) )(-1/2) with t(*) =0.917 677 02..., where eta represents the inverse temperature (for Brownian particles) or the mass (for bacterial colonies), and eta(c) is the critical value of eta above which the system blows up. This result is in perfect agreement with the numerical solution of the Smoluchowski-Poisson system. We also determine the exact asymptotic expression of the relaxation time close to but above the critical temperature and derive a large time asymptotic expansion for the density profile exactly at the critical point.

  17. Speed, amplitude, and asymmetry of lip movement in voluntary puckering and blowing expressions: implications for facial assessment.

    PubMed

    Schmidt, Karen L; VanSwearingen, Jessie M; Levenstein, Rachel M

    2005-07-01

    The context of voluntary movement during facial assessment has significant effects on the activity of facial muscles. Using automated facial analysis, we found that healthy subjects instructed to blow produced lip movements that were longer in duration and larger in amplitude than when subjects were instructed to pucker. We also determined that lip movement for puckering expressions was more asymmetric than lip movement in blowing. Differences in characteristics of lip movement were noted using facial movement analysis and were associated with the context of the movement. The impact of the instructions given for voluntary movement on the characteristics of facial movement might have important implications for assessing the capabilities and deficits of movement control in individuals with facial movement disorders. If results generalize to the clinical context, assessment of generally focused voluntary facial expressions might inadequately demonstrate the full range of facial movement capability of an individual patient.

  18. Effects of individual polychlorinated naphthalene (PCN) components of Halowax 1051 and two defined, artificial PCN mixtures on AHR and CYP1A1 protein expression, steroid secretion and expression of enzymes involved in steroidogenesis (CYP17, 17β-HSD and CYP19) in porcine ovarian follicles.

    PubMed

    Barć, Justyna; Gregoraszczuk, Ewa Łucja

    2014-08-01

    In this study we tried to answer a question which component of Halowax 1051 is responsible for, observed in previously published study, androgenic effects of the mixture, and whether it is possible to draw conclusions about the action of mixtures by examining the effect of an indicator congener. Ovarian follicles were incubated with individual congeners of an artificial mixture for 6-24h. At the end of the incubation period, media were collected for determination of progesterone (P4), androstenedione (A4), testosterone (T) and estradiol (E2) levels by enzyme immunoassay, and follicles were retained for an examination of aryl hydrocarbon receptor (AHR), cytochrome p450 enzymes (CYP1A1, CYP17, CYP19), and 17β-hydroxysteroid dehydrogenase (17β-HSD) protein expression by Western blotting. CN73 in dose 50pg/ml after 6h had no effect and decreased AHR expression after 24h, while at dose 400pg/ml increased AHR protein expression after 6h of exposure which remained elevated after 24h. CN74 and CN75 at both concentrations tested (25 and 50pg/ml) stimulated AHR protein expression after 6h and decreased it after 24h of exposure. Individual congeners induced a rapid increase in CYP1A1 protein expression, with a rank order of efficacy of CN73>CN74=CN75. All congeners increased P4/A4 and T/E2 secretion ratios in association with a decrease in the A4/T ratio, pointing to androgenic and anti-estrogenic properties of PCNs in ovarian follicles. The most potent congener in this context was CN73. The effects of mixtures were comparable to those of CN74 and CN75, and were not as strong as those observed for CN73. Collectively, these data suggest antagonistic actions of single congeners in a mixture, indicating that the actions of a mixture cannot be predicted based on the actions of individual congeners.

  19. Blow-up of solutions of an abstract Cauchy problem for a formally hyperbolic equation with double non-linearity

    NASA Astrophysics Data System (ADS)

    Korpusov, M. O.; Panin, A. A.

    2014-10-01

    We consider an abstract Cauchy problem for a formally hyperbolic equation with double non-linearity. Under certain conditions on the operators in the equation, we prove its local (in time) solubility and give sufficient conditions for finite-time blow-up of solutions of the corresponding abstract Cauchy problem. The proof uses a modification of a method of Levine. We give examples of Cauchy problems and initial-boundary value problems for concrete non-linear equations of mathematical physics.

  20. Some ultrastructural superficial changes in house fly (Diptera: Muscidae) and blow fly (Diptera: Calliphoridae) larvae induced by eucalyptol oil.

    PubMed

    Sukontason, Kabkaew L; Sukontason, Kom; Boonchu, Noppawan; Piangjai, Somsak

    2004-01-01

    The ultrastructural superficial changes in third instar house fly (Musca domestica) and blow fly (Chrysomya megacephala) induced by eucalyptol oil were observed using scanning electron microscopy. Dipped in 0.902 g/ml eucalyptol for 30 sec, the larvae integument of both species showed significant aberrant appearance of the body surface, particularly swelling integument, bleb formation, partial breach and deformation of spines. PMID:15517029

  1. Extrusion foaming of thermoplastic cellulose acetate from renewable resources using a two-component physical blowing agent system

    NASA Astrophysics Data System (ADS)

    Hopmann, Ch.; Windeck, C.; Hendriks, S.; Zepnik, S.; Wodke, T.

    2014-05-01

    Thermoplastic cellulose acetate (CA) is a bio-based polymer with optical, mechanical and thermal properties comparable to those of polystyrene (PS). The substitution of the predominant petrol-based PS in applications like foamed food trays can lead to a more sustainable economic practice. However, CA is also suitable for more durable applications as the biodegradability rate can be controlled by adjusting the degree of substitutions. The extrusion foaming of CA still has to overcome certain challenges. CA is highly hydrophilic and can suffer from hydrolytic degradation if not dried properly. Therefore, the influence of residual moisture on the melt viscosity is rather high. Beyond, the surface quality of foam CA sheets is below those of PS due to the particular foaming behaviour. This paper presents results of a recent study on extrusion foamed CA, using a two-component physical blowing agent system compromising HFO 1234ze as blowing agent and organic solvents as co-propellant. Samples with different co-propellants are processed on a laboratory single screw extruder at IKV. Morphology and surface topography are investigated with respect to the blowing agent composition and the die pressure. In addition, relationships between foam density, foam morphology and the propellants are analysed. The choice of the co-propellant has a significant influence on melt-strength, foaming behaviour and the possible blow-up ratio of the sheet. Furthermore, a positive influence of the co-propellant on the surface quality can be observed. In addition, the focus is laid on the effect of external contact cooling of the foamed sheets after the die exit.

  2. Small scale noise and wind tunnel tests of upper surface blowing nozzle flap concepts. Volume 1. Aerodynamic test results

    NASA Technical Reports Server (NTRS)

    Renselaer, D. J.; Nishida, R. S.; Wilkin, C. A.

    1975-01-01

    The results and analyses of aerodynamic and acoustic studies conducted on the small scale noise and wind tunnel tests of upper surface blowing nozzle flap concepts are presented. Various types of nozzle flap concepts were tested. These are an upper surface blowing concept with a multiple slot arrangement with seven slots (seven slotted nozzle), an upper surface blowing type with a large nozzle exit at approximately mid-chord location in conjunction with a powered trailing edge flap with multiple slots (split flow or partially slotted nozzle). In addition, aerodynamic tests were continued on a similar multi-slotted nozzle flap, but with 14 slots. All three types of nozzle flap concepts tested appear to be about equal in overall aerodynamic performance but with the split flow nozzle somewhat better than the other two nozzle flaps in the landing approach mode. All nozzle flaps can be deflected to a large angle to increase drag without significant loss in lift. The nozzle flap concepts appear to be viable aerodynamic drag modulation devices for landing.

  3. Impact of Cloud and Blowing Snow on Ice Sheet Altimetry: a Comparison between ICESat and ICESat-2

    NASA Astrophysics Data System (ADS)

    Yang, Y.; Marshak, A.; Palm, S. P.; Varnai, T.

    2015-12-01

    Clouds and blowing snow have long been a concern for lidar altimetry. Scattering inside the layer increases the photon path and makes the surface appear further away from the satellite. This effect is referred to as "atmospheric path delay". The ICESat and ICESat-2 missions' high accuracy requirement on the ice/snow surface elevation measurements makes understanding and quantifying this effect essential. We have developed a comprehensive framework that can simulate the analog waveform behavior of the Geoscience Laser Altimeter System (GLAS) onboard ICESat and the photon counting signal of the Advanced Topographic Laser Altimeter System (ATLAS) onboard ICESat-2. In this presentation, we will (1) review the cloud and blowing snow distributions over the polar ice sheets; (2) discuss how different factors affect the value of the atmospheric path delay, such as scattering layer height, optical thickness, and lidar field of view (FOV); (3) demonstrate that the delay is much less for ICESat-2 (centimeter level) compared to ICESat (decimeter level) due to the much smaller lidar FOV; (4) show the cloud detectability difference between ICESat and ICESat-2 and its implication to path delay corrections. The effect of cloud and blowing snow on first photon bias will also be discussed.

  4. AMELIA CESTOL Test: Acoustic Characteristics of Circulation Control Wing with Leading-and Trailing-Edge Slot Blowing

    NASA Technical Reports Server (NTRS)

    Horne, Clifton; Burnside, Nathan J.

    2013-01-01

    Aeroacoustic measurements of the 11 % scale full-span AMELIA CESTOL model with leading- and trailing-edge slot blowing circulation control (CCW) wing were obtained during a recent test in the Arnold Engineering Development Center 40- by 80-Ft. Wind Tunnel at NASA Ames Research Center, Sound levels and spectra were acquired with seven in-flow microphones and a 48-element phased microphone array for a variety of vehicle configurations, CCW slot flow rates, and forward speeds, Corrections to the measurements and processing are in progress, however the data from selected configurations presented in this report confirm good measurement quality and dynamic range over the test conditions, Array beamform maps at 40 kts tunnel speed show that the trailing edge flap source is dominant for most frequencies at flap angles of 0deg and 60deg, The overall sound level for the 60deg flap was similar to the 0deg flap for most slot blowing rates forward of 90deg incidence, but was louder by up to 6 dB for downstream angles, At 100 kts, the in-flow microphone levels were louder than the sensor self-noise for the higher blowing rates, while passive and active background noise suppression methods for the microphone array revealed source levels as much as 20 dB lower than observed with the in-flow microphones,

  5. The Role of Blowing Snow in the Activation of Bromine over First-Year Antarctic Sea Ice

    NASA Astrophysics Data System (ADS)

    Lieb-Lappen, R.; Obbard, R. W.

    2014-12-01

    It is well known that during the polar springtime, halide sea salt ions, in particular Br-, are through a series of heterogeneous reactions photochemically activated into reactive halogen species, such as Br and BrO, that breakdown polar tropospheric ozone. This research investigated the role of blowing snow in transporting salts from the sea ice/snow surface into reactive bromine species in the air. For two different locations over first-year ice in the Ross Sea, Antarctica, collection baskets captured blowing snow at four different heights on October 25, following a blowing snow event the day before. In addition, sea ice cores and surface snow samples were collected throughout the month long campaign. Cl-/Br- ratios were constant in sea ice and surface snow, and only in lofted snow did bromide become depleted relative to chloride. This suggests that replenishment of bromide in the snowpack occurs faster than bromine activation in mid-strength wind conditions (approximately 10 m/s). Sulfate concentrations were stable through the bottom half of sea ice cores, but were quite variable in the upper half and in surface snow. Lofted snow was greatly depleted in sulfate, likely as a result of mirabilite precipitation in brine prior to brine uptake in the snow and subsequent lofting. Nitrate was found in greater quantities for upper level baskets and in some surface snow samples, consistent with active cycling through atmospheric chemical reactions.

  6. The role of blowing snow in the activation of bromine over first-year Antarctic sea ice

    NASA Astrophysics Data System (ADS)

    Lieb-Lappen, R. M.; Obbard, R. W.

    2015-07-01

    It is well known that during polar springtime halide sea salt ions, in particular Br-, are photochemically activated into reactive halogen species (e.g., Br and BrO), where they break down tropospheric ozone. This research investigated the role of blowing snow in transporting salts from the sea ice/snow surface into reactive bromine species in the air. At two different locations over first-year ice in the Ross Sea, Antarctica, collection baskets captured blowing snow at different heights. In addition, sea ice cores and surface snow samples were collected throughout the month-long campaign. Over this time, sea ice and surface snow Br- / Cl- mass ratios remained constant and equivalent to seawater, and only in lofted snow did bromide become depleted relative to chloride. This suggests that replenishment of bromide in the snowpack occurs faster than bromine activation in mid-strength wind conditions (approximately 10 m s-1) or that blowing snow represents only a small portion of the surface snowpack. Additionally, lofted snow was found to be depleted in sulfate and enriched in nitrate relative to surface snow.

  7. The effect of blowing pressure, lip force and tonguing on transients: A study using a clarinet-playing machine.

    PubMed

    Li, Weicong; Almeida, André; Smith, John; Wolfe, Joe

    2016-08-01

    Wind instrument players control the initial and final transients of notes using breath, lips, and tonguing. This paper uses a clarinet-playing machine and high-speed camera to investigate how blowing pressure, lip force, and tonguing parameters affect transients. After tongue release, the reed quickly comes to rest, losing its mechanical energy. However, the changing aperture past the reed rapidly changes the airflow. For pressure above the oscillation threshold, successive interactions between reflections of this pulse of airflow and the reed produce an exponential increase in the sound. The rates r of exponential increase in the fundamental of the sound range from several tens to several hundreds of dB s(-1), as functions of blowing pressure and lip force. Because the reed's initial mechanical energy is lost, tongue force and acceleration have little effect on r. However, larger tongue force and acceleration produce more rapid changes in flow, which start notes sooner after tongue release. Further, large tongue force increases the third harmonic during the transient. There is a hysteresis region on the (pressure, lip force) plane where regenerative oscillation is not produced spontaneously by increasing blowing pressure only. Here, tongue action can initiate sustained notes at low pressure. PMID:27586739

  8. Static investigation of the circulation control wing/upper surface blowing concept applied to the quiet short haul research aircraft

    NASA Technical Reports Server (NTRS)

    Eppel, J. C.; Shovlin, M. D.; Jaynes, D. N.; Englar, R. J.; Nichols, J. H., Jr.

    1982-01-01

    Full scale static investigations were conducted on the Quiet Short Haul Research Aircraft (QSRA) to determine the thrust deflecting capabilities of the circulation control wing/upper surface blowing (CCW/USB) concept. This scheme, which combines favorable characteristics of both the A-6/CCW and QSRA, employs the flow entrainment properties of CCW to pneumatically deflect engine thrust in lieu of the mechanical USB flap system. Results show that the no moving parts blown system produced static thrust deflections in the range of 40 deg to 97 deg (depending on thrust level) with a CCW pressure of 208,900 Pa (30.3 psig). In addition, the ability to vary horizontal forces from thrust to drag while maintaining a constant vertical (or lift) value was demonstrated by varying the blowing pressure. The versatility of the CCW/USB system, if applied to a STOL aircraft, was confirmed, where rapid conversion from a high drag approach mode to a thrust recovering waveoff or takeoff configuration could be achieved by nearly instantaneous blowing pressure variation.

  9. Towards improving the efficiency of blowing through a permeable wall and prospects of its use for a flow control

    NASA Astrophysics Data System (ADS)

    Kornilov, V. I.; Boiko, A. V.

    2016-10-01

    Modern achievements, status, and prospects of studies on reducing the turbulent friction and aerodynamic drag with the help of the blowing through a permeable wall are discussed. The main focus is placed upon a physical modeling of the process of boundary layer blowing in the framework of the dimensional theory, a critical analysis of experimental and numerical results for different conditions of air blowing through a high-tech finely perforated wall including the case of external-pressure-flow air supply in wind tunnel, and elicitation of the physical mechanisms responsible for the reduction of turbulent friction at flow-exposed surfaces. It is shown that the use of air supply through the micro-perforated wall with low effective roughness, which is manufactured in compliance with the highest necessary requirements to quality and geometry of orifices, is quite a justified means for easy, affordable, and reliable control of near-wall turbulent flows in laboratory experiment and numerical simulation. This approach can provide a sustained reduction of local skin friction coefficient along flat plate, which in some cases reaches 90%.

  10. Patch testing with perfume mixture.

    PubMed

    Veien, N K; Hattel, T; Justesen, O; Nørholm, A

    1982-01-01

    145 of 1116 patients patch tested with the standard series of the International Contact Dermatitis Research Group, including the recently introduced perfume mixture, had positive patch test reactions to at least one of the traditional screening agents for fragrance allergy or to the perfume mixture. In 96 of 145 patients the positive patch tests could be explained as being related to fragrance allergy. The perfume mixture was considered a useful screening agent for fragrance allergy. However, the results indicate that it is still necessary to employ several screening agents to detect this type of hypersensitivity.

  11. Flow visualization study of spanwise blowing applied to the F-4 fighter aircraft configuration. [water tunnel test using a 1/48-scale model

    NASA Technical Reports Server (NTRS)

    Lorincz, D. J.

    1980-01-01

    Water tunnel studies were performed to define the changes that occur in vortex flow fields above the wing due to spanwise blowing over the inboard and outboard wing panels and over the trailing-edge flaps. Flow visualization photographs were obtained for angles of attack up to 30 deg and sideslip angles up to 10 deg. The sensitivity of the vortex flows to changes in flap deflection angle, nozzle position, and jet momentum coefficient was determined. Deflection of the leading edge flap delayed flow separation and the formation of the wing vortex to higher angles of attack. Spanwise blowing delayed the breakdown of the wing vortex to farther outboard and to higher angles of attack. Spanwise blowing over the trailing edge flap entrained flow downward, producing a lift increase over a wide range of angles of attack. The sweep angle of the windward wing was effectively reduced in sideslip. This decreased the stability of the wing vortex, and it burst farther inboard. Reduced wing sweep required a higher blowing rate to maintain a stable vortex. A vortex could be stabilized on the outboard wing panel when an outboard blowing nozzle was used. Blowing from both an inboard and an outboard nozzle was found to have a favorable interaction.

  12. Seasonal abundance of carrion-frequenting blow-flies (Diptera: Calliphoridae) in the Kruger National Park.

    PubMed

    Braack, L E; de Vos, V

    1987-12-01

    Monthly population fluctuations of carrion-frequenting blow-flies over a 24-month period were monitored using 2 carrion-baited traps in the southern Kruger National Park (KNP) and 3 in the northern KNP. All species displayed a clear seasonality. Chrysomyia marginalis and Chrysomyia albiceps were by far the most abundant. C. marginalis attained maximum abundance between November and March, with relatively low numbers present between May and September. C. albiceps maintained high population numbers between January and March in the northern KNP, with minimum numbers between May and August. In the southern KNP, C. albiceps became abundant from November to February, with low population levels between April and September. Although present only in relative low numbers, populations of Lucilia cuprina showed a clear increase in winter. Chrysomyia chloropyga, Chrysomyia putoria and Chrysomyia bezziana were trapped in significant numbers in the southern KNP, the latter 2 species reaching relative abundance in the warmer months, whereas C. chloropyga increased in cooler months from June to September. Graphic illustrations of monthly abundance are provided for all species.

  13. Dead-blow hammer design applied to a calibration target mechanism to dampen excessive rebound

    NASA Technical Reports Server (NTRS)

    Lim, Brian Y.

    1991-01-01

    An existing rotary electromagnetic driver was specified to be used to deploy and restow a blackbody calibration target inside of a spacecraft infrared science instrument. However, this target was much more massive than any other previously inherited design applications. The target experienced unacceptable bounce when reaching its stops. Without any design modification, the momentum generated by the driver caused the target to bounce back to its starting position. Initially, elastomeric dampers were used between the driver and the target. However, this design could not prevent the bounce, and it compromised the positional accuracy of the calibration target. A design that successfully met all the requirements incorporated a sealed pocket 85 percent full of 0.75 mm diameter stainless steel balls in the back of the target to provide the effect of a dead-blow hammer. The energy dissipation resulting from the collision of balls in the pocket successfully dampened the excess momentum generated during the target deployment. The disastrous effects of new requirements on a design with a successful flight history, the modifications that were necessary to make the device work, and the tests performed to verify its functionality are described.

  14. Lunar and Planetary Science XXXV: Martian Aeolian and Mass Wasting Processes: Blowing and Flowing

    NASA Technical Reports Server (NTRS)

    2004-01-01

    The session Martian Aeolian and Mass Wasting Processes: BLowing and Flowing included the following topics: 1) Three Decades of Martian Surface Changes; 2) Thermophysical Properties of Isidis Basin, Mars; 3) Intracrater Material in Eastern Arabia Terra: THEMIS, MOC, and MOLA Analysis of Wind-blown Deposits and Possible High-Inertia Source Material; 4) Thermal Properties of Sand from TES and THEMIS: Do Martian Dunes Make a Good Control for Thermal Inertia Calculations? 5) A Comparative Analysis of Barchan Dunes in the Intra-Crater Dune Fields and the North Polar Sand Sea; 6) Diluvial Dunes in Athabasca Valles, Mars: Morphology, Modeling and Implications; 7) Surface Profiling of Natural Dust Devils; 8) Martian Dust Devil Tracks: Inferred Directions of Movement; 9) Numerical Simulations of Anastomosing Slope Streaks on Mars; 10) Young Fans in an Equatorial Crater in Xanthe Terra, Mars; 11) Large Well-exposed Alluvual Fans in Deep Late-Noachian Craters; 12) New Evidence for the Formation of Large Landslides on Mars; and 13) What Can We Learn from the Ages of Valles Marineris Landslides on Martian Impact History?

  15. A transgenic embryonic sexing system for the Australian sheep blow fly Lucilia cuprina

    PubMed Central

    Yan, Ying; Scott, Maxwell J.

    2015-01-01

    Genetic approaches, including the sterile insect technique (SIT), have previously been considered for control of the Australian sheep blow fly Lucilia cuprina, a major pest of sheep. In an SIT program, females consume 50% of the diet but are ineffective as control agents and compete with females in the field for mating with sterile males, thereby decreasing the efficiency of the program. Consequently, transgenic sexing strains of L. cuprina were developed that produce 100% males when raised on diet that lacks tetracycline. However, as females die mostly at the pupal stage, rearing costs would not be significantly reduced. Here we report the development of transgenic embryonic sexing strains of L. cuprina. In these strains, the Lsbnk cellularization gene promoter drives high levels of expression of the tetracycline transactivator (tTA) in the early embryo. In the absence of tetracycline, tTA activates expression of the Lshid proapoptotic gene, leading to death of the embryo. Sex-specific RNA splicing of Lshid transcripts ensures that only female embryos die. Embryonic sexing strains were also made by combining the Lsbnk-tTA and tetO-Lshid components into a single gene construct, which will facilitate transfer of the technology to other major calliphorid livestock pests. PMID:26537204

  16. Theoretical aerodynamics of upper-surface-blowing jet-wing interaction

    NASA Technical Reports Server (NTRS)

    Lan, C. E.; Campbell, J. F.

    1975-01-01

    A linear, inviscid subsonic compressible flow theory is formulated to treat the aerodynamic interaction between the wing and an inviscid upper-surface-blowing (USB) thick jet with Mach number nonuniformity. The predicted results show reasonably good agreement with some available lift and induced-drag data. It was also shown that the thin-jet-flap theory is inadequate for the USB configurations with thick jet. Additional theoretical results show that the lift and induced drag were reduced by increasing jet temperature and increased by increasing jet Mach number. Reducing jet aspect ratio, while holding jet area constant, caused reductions in lift, induced drag, and pitching moment at a given angle of attack but with a minimal change in the curve of lift coefficient against induced-drag coefficient. The jet-deflection effect was shown to be beneficial to cruise performance. The aerodynamic center was shifted forward by adding power or jet-deflection angle. Moving the jet away from the wing surface resulted in rapid changes in lift and induced drag. Reducing the wing span of a rectangular wing by half decreased the jet-circulation lift by only 24 percent at a thrust coefficient of 2.

  17. A potential flight evaluation of an upper-surface-blowing/circulation-control-wing concept

    NASA Technical Reports Server (NTRS)

    Riddle, Dennis W.; Eppel, Joseph C.

    1987-01-01

    The technology data base for powered lift aircraft design has advanced over the last 15 years. NASA's Quiet Short Haul Research Aircraft (QSRA) has provided a flight verification of upper surface blowing (USB) technology. The A-6 Circulation Control Wing flight demonstration aricraft has provide data for circulation control wing (CCW) technology. Recent small scale wind tunnel model tests and full scale static flow turning test have shown the potential of combining USB with CCW technology. A flight research program is deemed necessary to fully explore the performance and control aspects of CCW jet substitution for the mechanical USB Coanda flap. The required hardware design would also address questions about the development of flight weight ducts and CCW jets and the engine bleed-air capabilities vs requirements. NASA's QSRA would be an optimum flight research vehicle for modification to the USB/CCW configuration. The existing QSRA data base, the design simplicity of the QSRA wing trailing edge controls, availability of engine bleed-air, and the low risk, low cost potential of the suggested program is discussed.

  18. In-situ aging of roof systems containing polyisocyanurate roof insulation foamed with alternative blowing agents

    SciTech Connect

    Desjarlais, A.O.; Christian, J.E.; Graves, R.S.

    1993-10-01

    Experimental polyisocyanurate (PIR) foam roof insulations with permeable facers were installed in roofing systems and continuously monitored for thermal performance for four years. The foams were produced using a specific formulation that represented current technology in 1989 and were blown with CFC-11, HCFC-123, and HCFC-141b. These foams were installed in roof systems comprised of loosely-laid insulation boards covered by either a loosely-laid single ply white or black membrane. The in-situ testing was carried out on an outdoor test facility, the Roof Thermal Research Apparatus (RTRA). Additional specimens of these foams were aged in the laboratory and periodically evaluated using laboratory measurement equipment. This paper summarizes the in-situ data compiled to date, compares these data with the laboratory results, and examines whether the proposed laboratory procedure for accelerating the aging of foams by the slicing and scaling method accurately predicts the aging characteristics of these materials installed in roof systems. These experiments are part of a joint industry/government project established to evaluate the technical viability of alternative HCFC blowing agents for rigid closed-cell polyisocyanurate foam roof insulations. Members of the project are the US Department of Energy (DOE)/Oak Ridge National Laboratory (ORNL), the US Environmental Protection Agency (EPA), the Society of the Plastics Industry-Polyurethane Division (SPI), the Polyisocyanurate Insulation Manufacturers Association (PIMA), and the National Roofing Contractors Association (NRCA).

  19. Optimized in-situ window cleaning system by laser blow-off through optical fiber

    NASA Astrophysics Data System (ADS)

    Alfier, A.; Pasqualotto, R.; Giudicotti, L.; Cervaro, V.; Franchin, L.

    2010-05-01

    An optimized in-situ window cleaning system by laser blow-off through optical fiber has been developed on the basis of a feasibility study previously presented. The beam generated from a Q-switched Nd:YAG laser (up to 330mJ output energy, pulse duration 5ns FWHM with 10Hz repetition rate) is launched into a high damage threshold optical fiber (Ø=1mm) through an f=80mm lens kept in a sealed box at 1mbar pressure. The fiber output is focused on the coated surface of a vacuum window previously exposed to the plasma of the RFX-mod experiment. We investigate the energy density threshold necessary to ablate the impurity deposition substrate: above threshold a single laser pulse recovers ~95% of the window transmission before its exposure to the plasma, while below it the efficiency of the cleaning process is too poor. The system so conceived can clean completely the largest window on RFX-mod (104mm2 surface) in about 20minutes. We also present first results obtained firing the laser directly on a bundle of small core diameter fibers, showing performance similar to those attainable with commercial products.

  20. Blowing Snow - A Major Source of Aerosol in the Polar Regions?

    NASA Astrophysics Data System (ADS)

    Kalnajs, L.; DeCarlo, P. F.; Giordano, M.; Davis, S. M.; Deshler, T.; Johnson, A.; Goetz, J. D.; Mukherjee, A. D.; Slater, A. G.

    2015-12-01

    Sea salt aerosol is the dominant aerosol component in unpolluted Polar Regions, particularly in the sea ice zone. In the lower latitude liquid ocean, wave action and bubble bursting is thought to be the main mechanism for sea salt aerosol production. However there is growing evidence that in the Polar Regions, particularly near sea ice, that the sublimation of wind lofted salty snow may be a dominant source of sea salt aerosol. An extensive set of aerosol sizing and compositional measurements was made at sea ice location near Ross Island, Antarctica during two field measurement campaigns - a summer campaign in 2014 and late winter campaign in 2015. Sizing measurements from both open and closed path aerosol instruments, and compositional measurements from an Aerosol Mass Spectrometer suggest that there is a significant enhancement in both super and sub micron aerosol associated with high wind events and blowing snow in the boundary layer. While the composition of this aerosol indicates that it is primarily of marine origin, the ratios of the major sea salt ions suggest that processing in the snow pack significantly modifies the aerosol. This alternate sea salt aerosol production mechanism could have significant impact on the modeling of tropospheric halogen chemistry and on the interpretation of sea salt-based proxies in the ice core record.

  1. How are soap bubbles blown? Fluid dynamics of soap bubble blowing

    NASA Astrophysics Data System (ADS)

    Davidson, John; Lambert, Lori; Sherman, Erica; Wei, Timothy; Ryu, Sangjin

    2013-11-01

    Soap bubbles are a common interfacial fluid dynamics phenomenon having a long history of delighting not only children and artists but also scientists. In contrast to the dynamics of liquid droplets in gas and gas bubbles in liquid, the dynamics of soap bubbles has not been well documented. This is possibly because studying soap bubbles is more challenging due to there existing two gas-liquid interfaces. Having the thin-film interface seems to alter the characteristics of the bubble/drop creation process since the interface has limiting factors such as thickness. Thus, the main objective of this study is to determine how the thin-film interface differentiates soap bubbles from gas bubbles and liquid drops. To investigate the creation process of soap bubbles, we constructed an experimental model consisting of air jet flow and a soap film, which consistently replicates the conditions that a human produces when blowing soap bubbles, and examined the interaction between the jet and the soap film using the high-speed videography and the particle image velocimetry.

  2. Interaction of antimicrobial preservatives with blow-fill-seal packs: correlating sorption with solubility parameters.

    PubMed

    Amin, Aeshna; Dare, Manish; Sangamwar, Abhay; Bansal, Arvind Kumar

    2012-01-01

    The aim of this work was to study the interaction of four commonly used ophthalmic antimicrobial preservatives [benzyl alcohol (BA), chlorbutol (CBL), benzalkonium chloride (BKC), and chlorhexidine gluconate (CG)] with Blow-Fill-Seal (BFS) packs. Effect of packaging material [low-density polyethylene (LDPE), polypropylene (PP)], humidity (25% RH, 75% RH) and concentration (0.5, 1.0, 2.0 mM BA/CBL in LDPE) was studied. BKC and CG gave negligible loss (<4%) in BFS packs over a period of 3 months. BA and CBL, however, gave marked losses in LDPE (ca. 70-90%) and PP (ca. 7-25%) packs. Humidity did not have any effect on the sorption loss of any preservative. Loss of BA switched from Case II to anomalous behavior with increasing initial concentration. A two-stage sorption behavior was inherent at all concentrations. Loss of CBL followed anomalous behavior with biphasic kinetics of loss. It was concluded that all the four preservatives were appropriate for use in PP BFS packs. However, only BKC and CG were amenable to be used in LDPE BFS packs. Lastly, an empirical expression consisting of the "solubility parameter distance" and "molar volume" of preservatives was developed to correlate the preservative loss in LDPE with the physicochemical properties of the preservatives.

  3. Laboratory study of the PDX/PLT laser blow-off trace element injectors

    SciTech Connect

    Manos, D.; Ruzic, D.; Moore, R.; Cohen, S.

    1982-04-01

    A laboratory study of the beams produced by laser blow-off trace element injectors used on the PDX and PLT tokamaks has been conducted. Eight target materials were studied, in the form of thin films on glass substrates: Al, Si, Sc, Cr, Fe, Ni, Cu, and Mo. Beam detectors included a quadrupole mass spectrometer, gridded retarding field analyzer, and beam collector plates. The collector plates were later analyzed by optical and electron microscopy and Auger spectroscopy. The results show that the injection produces the following species, in the usual order of decreasing velocity: free electrons, plasma, free ions, highly excited neutral atoms, unexcited neutral atoms, and metal clusters having diameters ranging up to several microns. The percentages of the various species, as well as their distributions of velocities, were found to be strong functions of the metal used, the film thickness, and the laser power density. Monoatomic species are generally contained within a half angle of approx.12/sup 0/, while clusters are within approx.5/sup 0/. Models of the production mechanism and implications for the use of the device as a tokamak diagnostic are discussed.

  4. Optical measurement and modelling of parison sag and swell in blow moulding

    NASA Astrophysics Data System (ADS)

    Béreaux, Yves; Charmeau, Jean-Yves; Balcaen, Jean

    2011-05-01

    Blow moulding is a process whereby a cylindrical parison is extruded first, then pinched between the two halves of a mould and, finally, blown into the product. Parison size and shape result from complex interactions between mandrel and die geometries, processing parameters and viscoelastic properties of the polymeric material. Moreover, parison size changes with time due to sag. An innovative, contactless and online measurement technique of the parison is shown to be an effective tool to measure precisely parison diameter and thickness and to capture dimensional changes with time. This technique employs laser lighting of the parison and hinges on the refractive properties of molten polymer. Images taken with a digital camera are processed to give a precise measurement of diameter and thickness, at different time step during extrusion. Thus, parison swell and sag have been recorded for a commercial HDPE. Influence of processing parameters such as the rotational screw speed or die gap width can be brought forward. Thickness swell is found to possess a different behaviour from diameter swell. Swell is a purely viscoelastic phenomenon, therefore requiring a numerical modelling with an integral viscoelastic constitutive equation. On the other hand, sag has been measured and could be modelled from a Newtonian perspective using one dimensional convected coordinates. A sagging susceptibility coefficient of the polymer is deduced.

  5. Development of analysis technique to predict the material behavior of blowing agent

    NASA Astrophysics Data System (ADS)

    Hwang, Ji Hoon; Lee, Seonggi; Hwang, So Young; Kim, Naksoo

    2014-11-01

    In order to numerically simulate the foaming behavior of mastic sealer containing the blowing agent, a foaming and driving force model are needed which incorporate the foaming characteristics. Also, the elastic stress model is required to represent the material behavior of co-existing phase of liquid state and the cured polymer. It is important to determine the thermal properties such as thermal conductivity and specific heat because foaming behavior is heavily influenced by temperature change. In this study, three models are proposed to explain the foaming process and material behavior during and after the process. To obtain the material parameters in each model, following experiments and the numerical simulations are performed: thermal test, simple shear test and foaming test. The error functions are defined as differences between the experimental measurements and the numerical simulation results, and then the parameters are determined by minimizing the error functions. To ensure the validity of the obtained parameters, the confirmation simulation for each model is conducted by applying the determined parameters. The cross-verification is performed by measuring the foaming/shrinkage force. The results of cross-verification tended to follow the experimental results. Interestingly, it was possible to estimate the micro-deformation occurring in automobile roof surface by applying the proposed model to oven process analysis. The application of developed analysis technique will contribute to the design with minimized micro-deformation.

  6. How clarinettists articulate: The effect of blowing pressure and tonguing on initial and final transients.

    PubMed

    Li, Weicong; Almeida, André; Smith, John; Wolfe, Joe

    2016-02-01

    Articulation, including initial and final note transients, is important to tasteful music performance. Clarinettists' tongue-reed contact, the time variation of the blowing pressure P¯mouth, the mouthpiece pressure, the pressure in the instrument bore, and the radiated sound were measured for normal articulation, accents, sforzando, staccato, and for minimal attack, i.e., notes started very softly. All attacks include a phase when the amplitude of the fundamental increases exponentially, with rates r ∼1000 dB s(-1) controlled by varying both the rate of increase in P¯mouth and the timing of tongue release during this increase. Accented and sforzando notes have shorter attacks (r∼1300 dB s(-1)) than normal notes. P¯mouth reaches a higher peak value for accented and sforzando notes, followed by a steady decrease for accented notes or a rapid fall to a lower, nearly steady value for sforzando notes. Staccato notes are usually terminated by tongue contact, producing an exponential decrease in sound pressure with rates similar to those calculated from the bandwidths of the bore resonances: ∼400 dB s(-1). In all other cases, notes are stopped by decreasing P¯mouth. Notes played with different dynamics are qualitatively similar, but louder notes have larger P¯mouth and larger r. PMID:26936564

  7. The Blow Up Method for Brakke Flows: Networks Near Triple Junctions

    NASA Astrophysics Data System (ADS)

    Tonegawa, Yoshihiro; Wickramasekera, Neshan

    2016-09-01

    We introduce a parabolic blow-up method to study the asymptotic behavior of a Brakke flow of planar networks (that is a 1-dimensional Brakke flow in a two dimensional region) weakly close in a space-time region to a static multiplicity 1 triple junction J. We show that such a network flow is regular in a smaller space-time region, in the sense that it consists of three curves coming smoothly together at a single point at 120{^{circ}} angles, staying smoothly close to J and moving smoothly. Using this result and White's stratification theorem, we deduce that whenever a Brakke flow of networks in a space-time region {{mathcal {R}}} has no static tangent flow with density {{≥q}2}, there exists a closed subset {{Σ subset {mathcal {R}}}} of parabolic Hausdorff dimension at most 1 such that the flow is classical in {{mathcal {R}}backslashΣ}, that is near every point in {{mathcal {R}}backslashΣ}, the flow, if non-empty, consists of either an embedded curve moving smoothly or three embedded curves meeting smoothly at a single point at 120{^{circ}} angles and moving smoothly. In particular, such a flow is classical at all times except for a closed set of times of ordinary Hausdorff dimension at most {1/2}.

  8. Dynamics of laser-blow-off induced Li plume in confined geometry

    SciTech Connect

    Kumar, Bhupesh; Singh, R K; Kumar, Ajai

    2013-08-15

    Dynamics of Li plasma plume created by laser-blow-off technique in air ambient is reported. Plasma plume dynamics and its optical emission are investigated in planar and confined geometries using time resolved shadowgraph imaging and optical emission spectroscopy. Significant differences in the plasma characteristics in confined geometry are quantitatively investigated by comparing the plasma parameters (temperature and density) in free expansion and confined geometry configurations. Dynamics and physical parameters of the primary as well as the reflected shock waves (in confined geometry) and their interactions with expanding plasma are briefly addressed. A large enhancement in the emission intensities of Li I 610.3 nm (2p {sup 2}P{sub 1/2,3/2}← 3d {sup 2}P{sub 3/2,5/2}) and 670.8 nm (2s {sup 2}S{sub 1/2}← 2p {sup 2}P{sub 1/2,3/2}) is correlated with the shock wave dynamics in the two geometries. Strong self reversal in the neutral emission infers an increase in the population density of neutrals within the confined plasma plume.

  9. Familial searching on DNA mixtures with dropout.

    PubMed

    Slooten, K

    2016-05-01

    Familial searching, the act of searching a database for a relative of an unknown individual whose DNA profile has been obtained, is usually restricted to cases where the DNA profile of that person has been unambiguously determined. Therefore, it is normally applied only with a good quality single source profile as starting point. In this article we investigate the performance of the method if applied to mixtures with and without allelic dropout, when likelihood ratios are computed with a semi-continuous (binary) model. We show that mixtures with dropout do not necessarily perform worse than mixtures without, especially if some separation between the donors is possible due to their different dropout probabilities. The familial searching true and false positive rates of mixed profiles on 15 loci are in some cases better than those of single source profiles on 10 loci. Thus, the information loss due to the fact that the person of interest's DNA has been mixed with that of other, and is affected by dropout, can be less than the loss of information corresponding to having 5 fewer loci available for a single source trace. Profiles typed on 10 autosomal loci are often involved in familial searching casework since many databases, including the Dutch one, in part consist of such profiles. Therefore, from this point of view, there seems to be no objection to extend familial searching to mixed or degraded profiles.

  10. TEA laser gas mixture optimization

    NASA Astrophysics Data System (ADS)

    Lipchak, W. Michael; Luck, Clarence F.

    1982-11-01

    The topographical plot of an optimized parameter, such as pulse energy or peak power, on the gas mixture plane is presented as a useful aid in realizing optimum mixtures of helium, carbon dioxide, and nitrogen, for operation of CO2 TEA lasers. A method for generating such a plot is discussed and an example is shown. The potential benefits of this graphical technique are also discussed.

  11. TEA laser gas mixture optimization

    SciTech Connect

    Lipchak, W.M.; Luck, C.F.

    1982-11-01

    The topographical plot of an optimized parameter, such as pulse energy or peak power, on the gas mixture plane is presented as a useful aid in realizing optimum mixtures of helium, carbon dioxide, and nitrogen, for operation of CO/sub 2/ TEA lasers. A method for generating such a plot is discussed and an example is shown. The potential benefits of this graphical technique are also discussed.

  12. Second-order model selection in mixture experiments

    SciTech Connect

    Redgate, P.E.; Piepel, G.F.; Hrma, P.R.

    1992-07-01

    Full second-order models for q-component mixture experiments contain q(q+l)/2 terms, which increases rapidly as q increases. Fitting full second-order models for larger q may involve problems with ill-conditioning and overfitting. These problems can be remedied by transforming the mixture components and/or fitting reduced forms of the full second-order mixture model. Various component transformation and model reduction approaches are discussed. Data from a 10-component nuclear waste glass study are used to illustrate ill-conditioning and overfitting problems that can be encountered when fitting a full second-order mixture model. Component transformation, model term selection, and model evaluation/validation techniques are discussed and illustrated for the waste glass example.

  13. Ionization coefficients in gas mixtures

    NASA Astrophysics Data System (ADS)

    Marić, D.; Šašić, O.; Jovanović, J.; Radmilović-Rađenović, M.; Petrović, Z. Lj.

    2007-03-01

    We have tested the application of the common E/N ( E—electric field, N—gas number density) or Wieland approximation [Van Brunt, R.J., 1987. Common parametrizations of electron transport, collision cross section, and dielectric strength data for binary gas mixtures. J. Appl. Phys. 61 (5), 1773-1787.] and the common mean energy (CME) combination of the data for pure gases to obtain ionization coefficients for mixtures. Test calculations were made for Ar-CH4, Ar-N2, He-Xe and CH4-N2 mixtures. Standard combination procedure gives poor results in general, due to the fact that the electron energy distribution is considerably different in mixtures and in individual gases at the same values of E/N. The CME method may be used for mixtures of gases with ionization coefficients that do not differ by more than two orders of magnitude which is better than any other technique that was proposed [Marić, D., Radmilović-Rađenović, M., Petrović, Z.Lj., 2005. On parametrization and mixture laws for electron ionization coefficients. Eur. Phys. J. D 35, 313-321.].

  14. A mechanism for mitigation of blade-vortex interaction using leading edge blowing flow control

    NASA Astrophysics Data System (ADS)

    Weiland, Chris; Vlachos, Pavlos P.

    2009-09-01

    The interaction of a vortical unsteady flow with structures is often encountered in engineering applications. Such flow structure interactions (FSI) can be responsible for generating significant loads and can have many detrimental structural and acoustic side effects, such as structural fatigue, radiated noise and even catastrophic results. Amongst the different types of FSI, the parallel blade-vortex interaction (BVI) is the most common, often encountered in helicopters and propulsors. In this work, we report on the implementation of leading edge blowing (LEB) active flow control for successfully minimizing the parallel BVI. Our results show reduction of the airfoil vibrations up to 38% based on the root-mean-square of the vibration velocity amplitude. This technique is based on displacing an incident vortex using a jet issued from the leading edge of a sharp airfoil effectively increasing the stand-off distance of the vortex from the body. The effectiveness of the method was experimentally analyzed using time-resolved digital particle image velocimetry (TRDPIV) recorded at an 800 Hz rate, which is sufficient to resolve the spatio-temporal dynamics of the flow field and it was combined with simultaneous accelerometer measurements of the airfoil, which was free to oscillate in a direction perpendicular to the freestream. Analysis of the flow field spectra and a Proper Orthogonal Decomposition (POD) of the TRDPIV data of the temporally resolved planar flow fields indicate that the LEB effectively modified the flow field surrounding the airfoil and increased the convecting vortices stand-off distance for over half of the airfoil chord length. It is shown that LEB also causes a redistribution of the flow field spectral energy over a larger range of frequencies.

  15. Survival and development of the forensically important blow fly, Calliphora varifrons (Diptera: Calliphoridae) at constant temperatures.

    PubMed

    Voss, Sasha C; Cook, David F; Hung, Wei-Feng; Dadour, Ian R

    2014-09-01

    The influence of temperature on the development of the forensically important blow fly, Calliphora varifrons Malloch 1932 (Diptera: Calliphoridae), was investigated at seven constant temperatures ranging from 12 to 30 °C. C. varifrons completed development between 12 and 27 °C. At 30 °C larvae formed pupae but did not successfully emerge. Temperature significantly influenced development time, mortality, maximum larval length, and adult body size. Development time (larviposition to adult emergence) ranged from 16.65 ± 0.17 days at 27 °C to 49.93 ± 0.26 days at 12 °C. Development rate was essentially linear throughout the 12-27 °C temperature range. Linear estimates of lower developmental threshold and thermal requirement (K) for development of C. varifrons were 4.20 °C and 368.46 ± 26.38 K. At 30 °C, a slight inhibitory effect of high temperature on third instar development rate was observed followed by a rapid decline when subsequent development and survival ceased. Nonlinear estimates of lower developmental threshold for third instar development were comparatively higher (6.29 °C). Nonlinear estimates of optimal developmental temperature and upper lethal developmental threshold were 25.94 and 32.13 °C respectively. Mortality was high at both temperature extremes (12 and 27 °C) and lowest between 18 and 24 °C. Maximum larval length was inversely related to temperature. Adult body size was significantly smaller at 12 °C, peaked at 18 °C, and declined as temperatures increased. The species-specific development data presented are the first available for C. varifrons for use by forensic practitioners for estimation of minimum time since death.

  16. Blow-up profile to the solutions of two-coupled Schroedinger equations

    SciTech Connect

    Chen Jianqing; Guo Boling

    2009-02-15

    The model of the following two-coupled Schroedinger equations, i{sub t}+(1/2){delta}u=(g{sub 11}|u|{sup 2p}+g|u|{sup p-1}|v|{sup p+1})uu, (t,x)(set-membership sign)R{sub +}xR{sup N}, and iv{sub t}+(1/2){delta}v=(g|u|{sup p+1}|v|{sup p-1}+g{sub 22}|v|{sup 2p})v, (t,x)(set-membership sign)R{sub +}xR{sup N}, is proposed in the study of the Bose-Einstein condensates [Mitchell, et al., ''Self-traping of partially spatially incoherent light,'' Phys. Rev. Lett. 77, 490 (1996)]. We prove that for suitable initial data and p the solution blows up exactly like {delta} function. As a by-product, we prove that similar phenomenon occurs for the critical two-coupled Schroedinger equations with harmonic potential [Perez-Garcia, V. M. and Beitia, T. B., ''Sybiotic solitons in heteronuclear multicomponent Bose-Einstein condensates,'' Phys. Rev. A 72, 033620 (2005)], iu{sub t}+(1/2){delta}u=({omega}/2)|x|{sup 2}u+(g{sub 11}|u|{sup 2p}+g|u|{sup p-1}|v|{sup p+1})u, x(set-membership sign)R{sup N}, and iv{sub t}+(1/2){delta}v=({omega}/2)|x|{sup 2}v+(g|u|{sup p+1}|v|{sup p-1}+g{sub 22}|v|{sup 2p})v, x(set-membership sign)R{sup N}.

  17. Aerodynamic Characteristics of a Large-Scale Unswept Wing-Body-Tail Configuration with Blowing Applied Over the Flap and Wind Leading Edge

    NASA Technical Reports Server (NTRS)

    McLemore, H. Clyde; Peterson, John B., Jr.

    1960-01-01

    An investigation has been conducted in the Langley full-scale tunnel to determine the effects of a blowing boundary-layer-control lift-augmentation system on the aerodynamic characteristics of a large-scale model of a fighter-type airplane. The wing was unswept at the 70-percent- chord station, had an aspect ratio of 2.86, a taper ratio of 0.40, and 4-percent-thick biconvex airfoil sections parallel to the plane of symmetry. The tests were conducted over a range of angles of attack from approximately -4 deg to 23 deg for a Reynolds number of approximately 5.2 x 10(exp 6) which corresponds to a Mach number of 0.08. Blowing rates were normally restricted to values just sufficient to control air-flow separation. The results of this investigation showed that wing leading-edge blowing in combination with large values of wing leading-edge-flap deflection was a very effective leading-edge flow-control device for wings having highly loaded trailing-edge flaps. With leading-edge blowing there was no hysteresis of the lift, drag, and pitching-moment characteristics upon recovery from stall. End plates were found to improve the lift and drag characteristics of the test configuration in the moderate angle-of-attack range, and blockage to one-quarter of the blowing-slot area was not detrimental to the aerodynamic characteristics. Blowing boundary-layer control resulted in a considerably reduced landing speed and reduced landing and take-off distances. The ailerons were very effective lateral-control devices when used with blowing flaps.

  18. Highly-Complex Environmentally-Realistic Mixtures: Challenges and Advances

    EPA Science Inventory

    The difficulties involved in design, conduct, analysis and interpretation of defmed mixtures experiments and use of the resulting data in risk assessment are now wellknown to the toxicology, risk assessment and risk management communities. The arena of highly-complex environment...

  19. Bayesian Kernel Mixtures for Counts

    PubMed Central

    Canale, Antonio; Dunson, David B.

    2011-01-01

    Although Bayesian nonparametric mixture models for continuous data are well developed, there is a limited literature on related approaches for count data. A common strategy is to use a mixture of Poissons, which unfortunately is quite restrictive in not accounting for distributions having variance less than the mean. Other approaches include mixing multinomials, which requires finite support, and using a Dirichlet process prior with a Poisson base measure, which does not allow smooth deviations from the Poisson. As a broad class of alternative models, we propose to use nonparametric mixtures of rounded continuous kernels. An efficient Gibbs sampler is developed for posterior computation, and a simulation study is performed to assess performance. Focusing on the rounded Gaussian case, we generalize the modeling framework to account for multivariate count data, joint modeling with continuous and categorical variables, and other complications. The methods are illustrated through applications to a developmental toxicity study and marketing data. This article has supplementary material online. PMID:22523437

  20. Bayesian Kernel Mixtures for Counts.

    PubMed

    Canale, Antonio; Dunson, David B

    2011-12-01

    Although Bayesian nonparametric mixture models for continuous data are well developed, there is a limited literature on related approaches for count data. A common strategy is to use a mixture of Poissons, which unfortunately is quite restrictive in not accounting for distributions having variance less than the mean. Other approaches include mixing multinomials, which requires finite support, and using a Dirichlet process prior with a Poisson base measure, which does not allow smooth deviations from the Poisson. As a broad class of alternative models, we propose to use nonparametric mixtures of rounded continuous kernels. An efficient Gibbs sampler is developed for posterior computation, and a simulation study is performed to assess performance. Focusing on the rounded Gaussian case, we generalize the modeling framework to account for multivariate count data, joint modeling with continuous and categorical variables, and other complications. The methods are illustrated through applications to a developmental toxicity study and marketing data. This article has supplementary material online. PMID:22523437

  1. Unrestricted Mixture Models for Class Identification in Growth Mixture Modeling

    ERIC Educational Resources Information Center

    Liu, Min; Hancock, Gregory R.

    2014-01-01

    Growth mixture modeling has gained much attention in applied and methodological social science research recently, but the selection of the number of latent classes for such models remains a challenging issue, especially when the assumption of proper model specification is violated. The current simulation study compared the performance of a linear…

  2. Landfilling ash/sludge mixtures

    SciTech Connect

    Benoit, J.; Eighmy, T.T.; Crannell, B.S.

    1999-10-01

    The geotechnical properties of a mixture of municipal solid waste incinerator bottom ash and municipal wastewater treatment plant sludge was investigated for a proposed ash/sludge secure landfill. The components as well as mixtures ranging from 10:1 to 5:1 (ash:sludge, by volume) were evaluated, where appropriate, for a number of geotechnical index and mechanical properties including particle size, water content, specific gravity, density-moisture relationships, shear strength, and compressibility. The results from a compactibility study and stability analysis of the proposed landfill were used to help approve a landfill codisposal concept; a full-scale facility was constructed and is currently operating successfully.

  3. Modeling phase equilibria in mixtures containing hydrogen fluoride and halocarbons

    SciTech Connect

    Lencka, M. ); Anderko, A. Polish Academy of Sciences, Warszawa )

    1993-03-01

    Recently, much attention has been focused on the production of environmentally acceptable refrigerants, which not only offer desirable physico-chemical properties, but do not deplete the ozone layer and do not cause the greenhouse effect. The production of such refrigerants involves the separation of multicomponent mixtures containing hydrogen fluoride, hydrogen chloride, and various chlorinated and fluorinated hydrocarbons. Therefore, it is indispensable to know the phase behavior of these mixtures. While the phase behavior of refrigerant mixtures can be adequately modeled in the absence of HF using standard thermodynamic techniques, drastically increases the complexity of the mixture because of its unusually strong association. The association of HF manifests itself in its significantly reduced gas-phase compressibility factor and the strong nonideality of mixtures containing HF and hydrocarbons or halocarbons. In this work, the authors develop an accurate, yet simple, association model for HF and compare it with simulation data. The model is combined with a simple equation of state to yield a closed-form expression that is applicable to both pure fluids and mixtures. In addition to representing the pure-component data for HF, the theory accurately predicts phase equilibria in HF + halocarbon systems.

  4. 16 CFR 1500.5 - Hazardous mixtures.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 16 Commercial Practices 2 2014-01-01 2014-01-01 false Hazardous mixtures. 1500.5 Section 1500.5... HAZARDOUS SUBSTANCES AND ARTICLES; ADMINISTRATION AND ENFORCEMENT REGULATIONS § 1500.5 Hazardous mixtures. For a mixture of substances, the determination of whether the mixture is a “hazardous substance”...

  5. 14 CFR 23.1147 - Mixture controls.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Mixture controls. 23.1147 Section 23.1147... Accessories § 23.1147 Mixture controls. (a) If there are mixture controls, each engine must have a separate control, and each mixture control must have guards or must be shaped or arranged to prevent confusion...

  6. 16 CFR 1500.5 - Hazardous mixtures.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Hazardous mixtures. 1500.5 Section 1500.5... HAZARDOUS SUBSTANCES AND ARTICLES; ADMINISTRATION AND ENFORCEMENT REGULATIONS § 1500.5 Hazardous mixtures. For a mixture of substances, the determination of whether the mixture is a “hazardous substance”...

  7. 14 CFR 23.1147 - Mixture controls.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Mixture controls. 23.1147 Section 23.1147... Accessories § 23.1147 Mixture controls. (a) If there are mixture controls, each engine must have a separate control, and each mixture control must have guards or must be shaped or arranged to prevent confusion...

  8. 16 CFR 1500.5 - Hazardous mixtures.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 16 Commercial Practices 2 2011-01-01 2011-01-01 false Hazardous mixtures. 1500.5 Section 1500.5... HAZARDOUS SUBSTANCES AND ARTICLES; ADMINISTRATION AND ENFORCEMENT REGULATIONS § 1500.5 Hazardous mixtures. For a mixture of substances, the determination of whether the mixture is a “hazardous substance”...

  9. 14 CFR 23.1147 - Mixture controls.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Mixture controls. 23.1147 Section 23.1147... Accessories § 23.1147 Mixture controls. (a) If there are mixture controls, each engine must have a separate control, and each mixture control must have guards or must be shaped or arranged to prevent confusion...

  10. 14 CFR 23.1147 - Mixture controls.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Mixture controls. 23.1147 Section 23.1147... Accessories § 23.1147 Mixture controls. (a) If there are mixture controls, each engine must have a separate control, and each mixture control must have guards or must be shaped or arranged to prevent confusion...

  11. 16 CFR 1500.5 - Hazardous mixtures.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 16 Commercial Practices 2 2013-01-01 2013-01-01 false Hazardous mixtures. 1500.5 Section 1500.5... HAZARDOUS SUBSTANCES AND ARTICLES; ADMINISTRATION AND ENFORCEMENT REGULATIONS § 1500.5 Hazardous mixtures. For a mixture of substances, the determination of whether the mixture is a “hazardous substance”...

  12. 14 CFR 23.1147 - Mixture controls.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Mixture controls. 23.1147 Section 23.1147... Accessories § 23.1147 Mixture controls. (a) If there are mixture controls, each engine must have a separate control, and each mixture control must have guards or must be shaped or arranged to prevent confusion...

  13. 16 CFR 1500.5 - Hazardous mixtures.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 16 Commercial Practices 2 2012-01-01 2012-01-01 false Hazardous mixtures. 1500.5 Section 1500.5... HAZARDOUS SUBSTANCES AND ARTICLES; ADMINISTRATION AND ENFORCEMENT REGULATIONS § 1500.5 Hazardous mixtures. For a mixture of substances, the determination of whether the mixture is a “hazardous substance”...

  14. Large-scale static investigation of circulation-control-wing concepts applied to upper surface-blowing aircraft

    NASA Technical Reports Server (NTRS)

    Shovlin, M. D.; Englar, R. J.; Eppel, J. C.; Nichols, J. H., Jr.

    1987-01-01

    The use of a circulation control to deflect turbofan engine thrust beyond 90 deg. has been proven in full-scale static ground tests of the circulation-control-wing/upper-surface-blowing (CCW/USB) concept. This powered high-lift system employs a circular, blown trailing edge to replace the USB mechanical flaps to entrain engine-exhaust flow, and to obtain both a vertical-thrust component and an augmented circulation lift for short takeoff and landing (STOL) applications. Previous tests (Phase 1), done in 1982, of a basic configuration installed on the Quiet Short Haul Research Aircraft confirmed these CCW/USB systems capabilities. A second phase (Phase 2) of full-scale, static, thrust-deflection investigations has reconfirmed the ability to deflect engine thrust from 40 to 102 deg., depending on thrust level. Five new configurations were evaluated and performance improvements noted for those configurations with larger blown span, fences or favorable engine interactions, smaller slot height, and larger radii with less than 180 deg. of CCW surface arc. In general, a 90 deg. circular arc with a smaller slot height provided the best performance, demonstrating that adequate thrust turning can be produced by a trailing-edge shape which may have minimal cruise-performance penalty. Thrust deflections were achieved at considerably lower blowing momentum than was required for the baseline case of Phase 1. Improved performance and versatility were thus confirmed for the CCW/USB system applied to STOL aircraft, where the potential for developing a non-moving-parts pneumatic thrust deflector to rapidly vary horizontal force from thrust to drag, while maintaining constant vertical force, appears quite promising. The conversion from high-lift to lower-drag cruise mode by merely terminating the blowing provides an effective STOL aircraft system.

  15. Arctic Sea Salt Aerosol from Blowing Snow and Sea Ice Surfaces - a Missing Natural Source in Winter

    NASA Astrophysics Data System (ADS)

    Frey, M. M.; Norris, S. J.; Brooks, I. M.; Nishimura, K.; Jones, A. E.

    2015-12-01

    Atmospheric particles in the polar regions consist mostly of sea salt aerosol (SSA). SSA plays an important role in regional climate change through influencing the surface energy balance either directly or indirectly via cloud formation. SSA irradiated by sunlight also releases very reactive halogen radicals, which control concentrations of ozone, a pollutant and greenhouse gas. However, models under-predict SSA concentrations in the Arctic during winter pointing to a missing source. It has been recently suggested that salty blowing snow above sea ice, which is evaporating, to be that source as it may produce more SSA than equivalent areas of open ocean. Participation in the 'Norwegian Young Sea Ice Cruise (N-ICE 2015)' on board the research vessel `Lance' allowed to test this hypothesis in the Arctic sea ice zone during winter. Measurements were carried out from the ship frozen into the pack ice North of 80º N during February to March 2015. Observations at ground level (0.1-2 m) and from the ship's crows nest (30 m) included number concentrations and size spectra of SSA (diameter range 0.3-10 μm) as well as snow particles (diameter range 50-500 μm). During and after blowing snow events significant SSA production was observed. In the aerosol and snow phase sulfate is fractionated with respect to sea water, which confirms sea ice surfaces and salty snow, and not the open ocean, to be the dominant source of airborne SSA. Aerosol shows depletion in bromide with respect to sea water, especially after sunrise, indicating photochemically driven release of bromine. We discuss the SSA source strength from blowing snow in light of environmental conditions (wind speed, atmospheric turbulence, temperature and snow salinity) and recommend improved model parameterisations to estimate regional aerosol production. N-ICE 2015 results are then compared to a similar study carried out previously in the Weddell Sea during the Antarctic winter.

  16. Blow-spun chitosan/PEG/PLGA nanofibers as a novel tissue engineering scaffold with antibacterial properties.

    PubMed

    Bienek, Diane R; Hoffman, Kathleen M; Tutak, Wojtek

    2016-09-01

    Blow spinning is continuing to gain attention in tissue engineering, as the resultant nanofibrous structures can be used to create a biomimetic environment. In this study, blow spinning was used to construct nanofiber scaffolds with up to 10 % chitosan and poly(DL-lactide-co-glycolide) in the absence or presence of poly(ethylene glycol). Scanning electron microscopy demonstrated that nanofibers were distributed randomly to form three-dimensional mats. With respect to chitosan concentration, the average fiber diameter did not differ statistically in either the absence or presence of poly(ethylene glycol). In poly(ethylene glycol)-formulations, the average fiber diameter ranged from (981.9 ± 611.3) nm to (1139.2 ± 814.2) nm. In vitro cellular metabolic activity and proliferation studies using keratinized rat squamous epithelial cells (RL-65) showed that cytocompatibility was not compromised with the addition of poly(ethylene glycol). The cell responses at lower (1 and 2.5 %) chitosan concentrations were not significantly different from the groups without chitosan or no scaffold when cultivated for 3, 6, or 9 days. However, >15 % reduction in cellular responses were observed at 10 % chitosan. In presence of poly(ethylene glycol), nearly a 1-log incremental reduction in the number of colony forming units of Streptococcus mutans occurred as the chitosan concentration increased from 0-1 to 2.5 %. Bacterial preparations tested with poly(ethylene glycol) and 5 or 10 % chitosan were not significantly different than the positive kill control. Taken together, the most favorable conditions for attaining cytocompatibility and maintaining antibacterial functionality existed in poly(ethylene glycol)/poly(DL-lactide-co-glycolide) blow-spun scaffolds with integrated 1 or 2.5 % chitosan. PMID:27568217

  17. Assessing the potential contribution of blowing snow to the mass balance of glaciers in the Cariboo Mountains of British Columbia, Canada

    NASA Astrophysics Data System (ADS)

    Yadghar, A.; Ainslie, B.; Jackson, P. L.; Dery, S. J.

    2009-05-01

    The difference between snow accumulation and ice ablation determines the mass balance of glaciers, with snowfall as the dominant input. However, blowing snow is another important term in glacier mass balance. Blowing snow occurs when loose particles of snow at the surface are entrained by winds exceeding a certain threshold for transport. The role of blowing snow in the surface mass balance of glaciers in the Cariboo Mountains (the northern extension of the Columbia Mountains) of British Columbia, Canada is assessed in this study. The regional atmospheric modeling system (RAMS) model is used to simulate several case studies of blowing snow in the region of interest. The simulations are validated with meteorological data from a mesoscale network (mesonet) of high-elevation automatic weather stations (AWSs) entitled the Cariboo Alpine Mesonet (CAMnet) that has been developed in the region since 2006. The mass divergence (convergence) fields from the RAMS simulations provide an indication of the blowing snow erosion (accumulation) areas. These are then compared with the spatial distribution of glaciers in the Cariboo Mountains. Our results suggest that snow drift may contribute significantly to the mass budget of glaciers in the region.

  18. Low-speed aerodynamic characteristics of a wing-canard configuration with underwing spanwise blowing on the trailing-edge flap system

    NASA Technical Reports Server (NTRS)

    Banks, Daniel W.; Paulson, John W., Jr.

    1987-01-01

    An investigation of the effects of spanwise blowing applied to the lower surface of a trailing-edge flap system on a wing-canard configuration has been conducted in the Langley 4- by 7-Meter Tunnel. The investigation studied spanwise-blowing angles of 30 deg., 45 deg., and 60 deg. measured from a perpendicular to the body center-line. The test conditions covered a range of free-stream dynamic pressures up to 50 psf for thrust coefficients up to 2.1 over a range of angles of attack from -2 deg. to 26 deg. Model height above the wind tunnel floor was varied from a height-to-span ratio of 1.70 down to 0.20 (a representative wheel touchdown height). The results indicate that blowing angles of 30 deg. and 45 deg. increase the induced-lift increment produced by spanwise blowing on the lower surface of a trailing-edge flap system. Increasing the blowing angle to 60 deg., in general, produces little further improvement.

  19. Melting of corrosion-resisting steels using air in bath agitation at the end of oxygen blowing

    NASA Astrophysics Data System (ADS)

    Gizatulin, R. A.; Valuev, D. V.; Valueva, A. V.; Yedesheva, Ch V.

    2014-10-01

    A number of metallurgical plants employ ladle stirring with argon at the end of oxygen blowing during the melting process of corrosion-resisting steels [1, 2]. At the same time, the scarcity and relatively high cost of argon, its low pressure in a shop air pipeline restrain most plants from using argon for corrosion-resisting steel production. Compressed air was used instead of argon to intensify the process of decarbonizing when chromium-nickel stainless steels were made with a 40-ton electric arc furnace at the Kuznetsk Metallurgical Plant.

  20. Ground simulation with moving belt and tangential blowing for full-scale automotive testing in a wind tunnel

    SciTech Connect

    Mercker, E.; Knape, H.W.

    1989-01-01

    This paper describes full-scale vehicle tests made on a standard-type passenger car in a wind tunnel and on the road in order to evaluate different moving-ground simulation techniques for wind tunnels. The test was first executed over a moving belt, supporting the car with a rear sting and measuring the aerodynamic forces with an internal balance. The test was then repeated with the same support arrangement over a fixed test-section floor, and moving-ground simulation was attained with boundary layer control by tangential blowing. Besides force measurements, the surface pressure distribution underneath the vehicle and at the base were also measured.

  1. Small scale wind tunnel model investigation of hybrid high lift systems combining upper surface blowing with the internally blown flap

    NASA Technical Reports Server (NTRS)

    Waites, W. L.; Chin, Y. T.

    1974-01-01

    A small-scale wind tunnel test of a two engine hybrid model with upper surface blowing on a simulated expandable duct internally blown flap was accomplished in a two phase program. The low wing Phase I model utilized 0.126c radius Jacobs/Hurkamp flaps and 0.337c radius Coanda flaps. The high wing Phase II model was utilized for continued studies on the Jacobs/Hurkamp flap. Principal study areas included: basic data both engines operative and with an engine out, control flap utilization, horizontal tail effectiveness, spoiler effectiveness, USB nacelle deflector study and USB/IBF pressure ratio effects.

  2. Reflectance properties of spinel-plagioclase mixtures

    NASA Astrophysics Data System (ADS)

    Cheek, L.; Jackson, C.; Dhingra, D.; Pieters, C. M.; Prissel, T. C.; Williams, K. B.

    2012-12-01

    Near-infrared spectra displaying the diagnostic properties of Mg-spinel have recently been reported in several lunar craters based on Moon Mineralogy Mapper (M3) data [1-5]. These spectra lack evidence for olivine or pyroxene, suggesting that they represent a spinel-plagioclase lithology [1]. Current hypotheses [6, 7] suggest that this lithology formed by interactions of a mafic or ultramafic liquid with an anorthositic country rock, but the proportions of spinel and plagioclase are unknown. The aim of this work is to constrain the modal abundances of spinel and plagioclase in the observed lithology using laboratory reflectance spectroscopy of particulate mixtures. Reflectance spectra of Mg-spinel display a strong absorption at ~2000 nm due to Fe2+ in a tetrahedral site [e.g., 8]. At higher FeO contents, > ~5 wt%, an octahedral absorption near 1000 nm is also apparent [9]. Plagioclase often displays a broad absorption centered near 1250 nm due to trace amounts (0.1 wt%) of Fe2+ in the Ca2+ site. Previous studies have noted that plagioclase must be present in extremely high abundances (~85 vol%) in order for the 1250 nm absorption to be apparent in mixtures with olivine and pyroxene [10, 11]. Recent nonlinear modeling has suggested that at least 50% plagioclase is necessary for the 1250 nm absorption to be apparent in a calculated mixture with spinel [12]. Our approach involves making mineral mixtures of spinel and plagioclase particulate samples and measuring near-infrared spectra of the bulk material. For the plagioclase endmember, we use terrestrial gem quality labradorite with ~0.3 wt% FeO. The spinel endmember was produced experimentally at Brown University (1500 C; fO2~ IW; sintered 72 hrs), and contains 5 wt% FeO. Preliminary results show that spectra of a 90% plagioclase - 10% spinel mixture only display the spectral properties of the spinel component; the 1250 nm absorption is not apparent. Importantly, the addition of 90% plagioclase does not significantly

  3. Odour suppression in binary mixtures.

    PubMed

    Cashion, Larry; Livermore, Andrew; Hummel, Thomas

    2006-10-01

    It has been suggested that odours causing stronger trigeminal activation suppress weaker trigeminal stimuli and that mixed olfactory-trigeminal stimuli suppress odorants that only activate one of these systems. Volunteer normosmic participants (n=20) were exposed to six odorants with varying trigeminal impact to test the hypothesis that more intense "trigeminal" odorants would suppress weaker trigeminal stimuli in binary odour mixtures. It was also hypothesised that stronger trigeminal odorants would dominate six-odour mixtures. The predicted linear pattern of suppression was not seen, with a quadratic model emerging from the data. Stronger trigeminal stimuli failed to dominate six-odour mixtures. Despite the fact that the major hypothesis was not supported, it can be hypothesised from this experiment that the effect of suppression in binary mixtures is reliant upon two major effects: (1) the association formed between odours and the multiple memory systems that they interact with during the encoding and recognition processes, and (2) the balance between activation of the olfactory and trigeminal systems.

  4. An NCME Instructional Module on Latent DIF Analysis Using Mixture Item Response Models

    ERIC Educational Resources Information Center

    Cho, Sun-Joo; Suh, Youngsuk; Lee, Woo-yeol

    2016-01-01

    The purpose of this ITEMS module is to provide an introduction to differential item functioning (DIF) analysis using mixture item response models. The mixture item response models for DIF analysis involve comparing item profiles across latent groups, instead of manifest groups. First, an overview of DIF analysis based on latent groups, called…

  5. Using Mixture Regression to Identify Varying Effects: A Demonstration with Paternal Incarceration

    ERIC Educational Resources Information Center

    Dyer, W. Justin; Pleck, Joseph; McBride, Brent

    2012-01-01

    The most widely used techniques for identifying the varying effects of stressors involve testing moderator effects via interaction terms in regression or multiple-group analysis in structural equation modeling. The authors present mixture regression as an alternative approach. In contrast to more widely used approaches, mixture regression…

  6. Uphill diffusion in multicomponent mixtures.

    PubMed

    Krishna, Rajamani

    2015-05-21

    Molecular diffusion is an omnipresent phenomena that is important in a wide variety of contexts in chemical, physical, and biological processes. In the majority of cases, the diffusion process can be adequately described by Fick's law that postulates a linear relationship between the flux of any species and its own concentration gradient. Most commonly, a component diffuses down the concentration gradient. The major objective of this review is to highlight a very wide variety of situations that cause the uphill transport of one constituent in the mixture. Uphill diffusion may occur in multicomponent mixtures in which the diffusion flux of any species is strongly coupled to that of its partner species. Such coupling effects often arise from strong thermodynamic non-idealities. For a quantitative description we need to use chemical potential gradients as driving forces. The transport of ionic species in aqueous solutions is coupled with its partner ions because of the electro-neutrality constraints; such constraints may accelerate or decelerate a specific ion. When uphill diffusion occurs, we observe transient overshoots during equilibration; the equilibration process follows serpentine trajectories in composition space. For mixtures of liquids, alloys, ceramics and glasses the serpentine trajectories could cause entry into meta-stable composition zones; such entry could result in phenomena such as spinodal decomposition, spontaneous emulsification, and the Ouzo effect. For distillation of multicomponent mixtures that form azeotropes, uphill diffusion may allow crossing of distillation boundaries that are normally forbidden. For mixture separations with microporous adsorbents, uphill diffusion can cause supra-equilibrium loadings to be achieved during transient uptake within crystals; this allows the possibility of over-riding adsorption equilibrium for achieving difficult separations.

  7. Uphill diffusion in multicomponent mixtures.

    PubMed

    Krishna, Rajamani

    2015-05-21

    Molecular diffusion is an omnipresent phenomena that is important in a wide variety of contexts in chemical, physical, and biological processes. In the majority of cases, the diffusion process can be adequately described by Fick's law that postulates a linear relationship between the flux of any species and its own concentration gradient. Most commonly, a component diffuses down the concentration gradient. The major objective of this review is to highlight a very wide variety of situations that cause the uphill transport of one constituent in the mixture. Uphill diffusion may occur in multicomponent mixtures in which the diffusion flux of any species is strongly coupled to that of its partner species. Such coupling effects often arise from strong thermodynamic non-idealities. For a quantitative description we need to use chemical potential gradients as driving forces. The transport of ionic species in aqueous solutions is coupled with its partner ions because of the electro-neutrality constraints; such constraints may accelerate or decelerate a specific ion. When uphill diffusion occurs, we observe transient overshoots during equilibration; the equilibration process follows serpentine trajectories in composition space. For mixtures of liquids, alloys, ceramics and glasses the serpentine trajectories could cause entry into meta-stable composition zones; such entry could result in phenomena such as spinodal decomposition, spontaneous emulsification, and the Ouzo effect. For distillation of multicomponent mixtures that form azeotropes, uphill diffusion may allow crossing of distillation boundaries that are normally forbidden. For mixture separations with microporous adsorbents, uphill diffusion can cause supra-equilibrium loadings to be achieved during transient uptake within crystals; this allows the possibility of over-riding adsorption equilibrium for achieving difficult separations. PMID:25761383

  8. Gravimetric methods for the preparation of standard gas mixtures

    NASA Astrophysics Data System (ADS)

    Milton, M. J. T.; Vargha, G. M.; Brown, A. S.

    2011-10-01

    The most widely used method for the preparation of primary standard gas mixtures involves weighing the individual components into a cylinder. We present a new mathematical description of the method and its uncertainties. We use this to demonstrate how strategies for serial dilution can be identified that minimize the uncertainty in the final mixture and show how they can be implemented practically. We review published reports of high accuracy gravimetry and give examples of relative uncertainties in the composition of standards approaching 1 part-per-million in the best cases and in the range of 100 to 1000 parts-per-million more typically.

  9. Blowing-Type Boundary-Layer Control as Applied to the Trailing-Edge Flaps of a 35 Degree Swept-Wing Airplane

    NASA Technical Reports Server (NTRS)

    Kelly, Mark W; Anderson, Seth B; Innis, Robert C

    1958-01-01

    A wind-tunnel investigation was made to determine the effects on the aerodynamic characteristics of a 35 degree swept-wing airplane of applying blowing-type boundary-layer control to the trailing-edge flaps. Flight tests of a similar airplane were then conducted to determine the effects of boundary-layer control on the handling qualities and operation of the airplane, particularly during landing and take-off. The wind-tunnel and flight tests indicated that blowing over the flaps produced large increases in flap lift increment, and significant increases in maximum lift. The use of blowing permitted reductions in the landing approach speeds of as much as 12 knots.

  10. Study of changes in the aerodynamic characteristics of the axisymmetric supersonic vehicle in case of gas blowing from the lateral surface

    NASA Astrophysics Data System (ADS)

    Kislovskiy, V. A.; Zvegintsev, V. I.

    2016-10-01

    Consider the flow around the axisymmetric supersonic vehicle with the use of gas jet blowing from the lateral surface. The blowing is made in series of points at different distances from the nose fairing. The aim of the work was to determine the changes in aerodynamic forces and the formation of the moment, when jet of gas blowing in different parts of the supersonic vehicle. The study was conducted by numerical modeling of different cases of injection. As a result, data were obtained which showed the degree of influence not only jet thrust from the jet flow, but same the impact of the redistribution of the flow by body surface on the formation of aerodynamic forces and moments.

  11. Multi-walled carbon nanotubes and poly(lactic acid) nanocomposite fibrous membranes prepared by solution blow spinning.

    PubMed

    Oliveira, Juliano E; Zucolotto, Valtencir; Mattoso, Luiz H C; Medeiros, Eliton S

    2012-03-01

    Nanocomposite fibers based on multi-walled carbon nanotubes (MWCNT) and poly(lactic acid) (PLA) were prepared by solution blow spinning (SBS). Fiber morphology was characterized by scanning electron microscopy (SEM) and optical microscopy (OM). Electrical, thermal, surface and crystalline properties of the spun fibers were evaluated, respectively, by conductivity measurements (4-point probe), thermogravimetric analyses (TGA), differential scanning calorimetry (DSC), contact angle and X-ray diffraction (XRD). OM analysis of the spun mats showed a poor dispersion of MWCNT in the matrix, however dispersion in solution was increased during spinning where droplets of PLA in solution loaded with MWCNT were pulled by the pressure drop at the nozzle, producing PLA fibers filled with MWCNT. Good electrical conductivity and hydrophobicity can be achieved at low carbon nanotube contents. When only 1 wt% MWCNT was added to low-crystalline PLA, surface conductivity of the composites increased from 5 x 10(-8) to 0.46 S/cm. Addition of MWCNT can slightly influence the degree of crystallinity of PLA fibers as studied by XRD and DSC. Thermogravimetric analyses showed that MWCNT loading can decrease the onset degradation temperature of the composites which was attributed to the catalytic effect of metallic residues in MWCNT. Moreover, it was demonstrated that hydrophilicity slightly increased with an increase in MWCNT content. These results show that solution blow spinning can also be used to produce nanocomposite fibers with many potential applications such as in sensors and biosensors. PMID:22755116

  12. The technical viability of alternative blowing agents in polyisocyanurate roof insulation: A cooperative industry/government project

    SciTech Connect

    Christian, J.E.; Courville, G.E.; Desjarlais, A.O.; Graves, R.S.; Linkous, R.L.; McElroy, D.L.; Weaver, F.J.; Wendt, R.L.; Yarbrough, D.W.

    1993-06-01

    This report is a summary of the cooperative industry/government program to establish the viability of alternative blowing agents to chlorofluorocarbons (CFCs). The project was initiated in 1989 following two workshops that focused on needed research on thermal insulation blown with substitutes for CFC-11 and CFC-12. The project is directed by a steering committee of representatives of the sponsors and of Oak Ridge National Laboratory (ORNL). The purpose of the project is to determine if the performance of polyisocyanurate (PIR) roof insulation foam boards blown with alternate agents differs from the performance of boards blown with CFC-1. This report describes apparent thermal conductivity (k) results obtained from field and laboratory tests from 1989 to 1992 on a set of experimental PIR laminate boardstock produced to evaluate the viability of alternative hydrochlorofluorocarbons (HCFCs) as blowing agents. All boardstock was manufactured from similar formulations that were not optimized for thermal performance. Commercial broadstock made in the future may differ in performance from this set. The PIR boards were prepared with CFC-11, HCFC-123, HCFC-141b, and 50/50 and 65/35 blends of HCFC-123/HCFC-141b.

  13. The role of blowing snow in the activation of bromine over first-year Antarctic sea ice

    NASA Astrophysics Data System (ADS)

    Lieb-Lappen, R. M.; Obbard, R. W.

    2015-04-01

    It is well known that during polar springtime halide sea salt ions, in particular Br-, are photochemically activated into reactive halogen species (e.g. Br and BrO), where they break down tropospheric ozone. This research investigated the role of blowing snow in transporting salts from the sea ice/snow surface into reactive bromine species in the air. At two different locations over first-year ice in the Ross Sea, Antarctica, collection baskets captured blowing snow at different heights. In addition, sea ice cores and surface snow samples were collected throughout the month-long campaign. Over this time, sea ice and surface snow Cl-/Br- mass ratios remained constant and equivalent to seawater, and only in lofted snow did bromide become depleted relative to chloride. This suggests that replenishment of bromide in the snowpack occurs faster than bromine activation in mid-strength wind conditions (approximately 10 m s-1). Additionally, lofted snow was found to be depleted in sulfate and enriched in nitrate relative to surface snow.

  14. Small scale model static acoustic investigation of hybrid high lift systems combining upper surface blowing with the internally blown flap

    NASA Technical Reports Server (NTRS)

    Cole, T. W.; Rathburn, E. A.

    1974-01-01

    A static acoustic and propulsion test of a small radius Jacobs-Hurkamp and a large radius Flex Flap combined with four upper surface blowing (USB) nozzles was performed. Nozzle force and flow data, flap trailing edge total pressure survey data, and acoustic data were obtained. Jacobs-Hurkamp flap surface pressure data, flow visualization photographs, and spoiler acoustic data from the limited mid-year tests are reported. A pressure ratio range of 1.2 to 1.5 was investigated for the USB nozzles and for the auxiliary blowing slots. The acoustic data were scaled to a four-engine STOL airplane of roughly 110,000 kilograms or 50,000 pounds gross weight, corresponding to a model scale of approximately 0.2 for the nozzles without deflector. The model nozzle scale is actually reduced to about .17 with deflector although all results in this report assume 0.2 scale factor. Trailing edge pressure surveys indicated that poor flow attachment was obtained even at large flow impingement angles unless a nozzle deflector plate was used. Good attachment was obtained with the aspect ratio four nozzle with deflector, confirming the small scale wind tunnel tests.

  15. Reduced-order modeling of the flow around a high-lift configuration with unsteady Coanda blowing

    NASA Astrophysics Data System (ADS)

    Semaan, Richard; Cordier, Laurent; Noack, Bernd; Kumar, Pradeep; Burnazzi, Marco; Tissot, Gilles

    2015-11-01

    We propose a low-dimensional POD model for the transient and post-transient flow around a high-lift airfoil with unsteady Coanda blowing over the trailing edge. This model comprises the effect of high-frequency modulated blowing which mitigates vortex shedding and increases lift. The structure of the dynamical system is derived from the Navier-Stokes equations with a Galerkin projection and from subsequent dynamic simplifications. The system parameters are determined with a data assimilation (4D-Var) method. The boundary actuation is incorporated into the model with actuation modes following Graham et al. (1999); Kasnakoğlu et al. (2008). As novel enabler, we show that the performance of the POD model significantly benefits from employing additional actuation modes for different frequency components associated with the same actuation input. In addition, linear, weakly nonlinear and fully nonlinear models are considered. The current study suggests that separate actuation modes for different actuation frequencies improve Galerkin model performance, in particular with respect to the important base-flow changes. We acknowledge (1) the Collaborative Research Centre (CRC 880) ``Fundamentals of High Lift of Future Civil Aircraft,'' and 2) the Senior Chair of Excellence ``Closed-loop control of turbulent shear flows using reduced-order models'' (TUCOROM).

  16. A blow to the fly - Lucilia cuprina draft genome and transcriptome to support advances in biology and biotechnology.

    PubMed

    Anstead, Clare A; Batterham, Philip; Korhonen, Pasi K; Young, Neil D; Hall, Ross S; Bowles, Vernon M; Richards, Stephen; Scott, Maxwell J; Gasser, Robin B

    2016-01-01

    The blow fly, Lucilia cuprina (Wiedemann, 1830) is a parasitic insect of major global economic importance. Maggots of this fly parasitize the skin of animal hosts, feed on excretions and tissues, and cause severe disease (flystrike or myiasis). Although there has been considerable research on L. cuprina over the years, little is understood about the molecular biology, biochemistry and genetics of this parasitic fly, as well as its relationship with its hosts and the disease that it causes. This situation might change with the recent report of the draft genome and transcriptome of this blow fly, which has given new and global insights into its biology, interactions with the host animal and aspects of insecticide resistance at the molecular level. This genomic resource will likely enable many fundamental and applied research areas in the future. The present article gives a background on L. cuprina and myiasis, a brief account of past and current treatment, prevention and control approaches, and provides a perspective on the impact that the L. cuprina genome should have on future research of this and related parasitic flies, and the design of new and improved interventions for myiasis. PMID:26944522

  17. The distribution of blow fly (Diptera: Calliphoridae) larval lengths and its implications for estimating post mortem intervals.

    PubMed

    Moffatt, Colin; Heaton, Viv; De Haan, Dorine

    2016-01-01

    The length or stage of development of blow fly (Diptera: Calliphoridae) larvae may be used to estimate a minimum postmortem interval, often by targeting the largest individuals of a species in the belief that they will be the oldest. However, natural variation in rate of development, and therefore length, implies that the size of the largest larva, as well as the number of larvae longer than any stated length, will be greater for larger cohorts. Length data from the blow flies Protophormia terraenovae and Lucilia sericata were collected from one field-based and two laboratory-based experiments. The field cohorts contained considerably more individuals than have been used for reference data collection in the literature. Cohorts were shown to have an approximately normal distribution. Summary statistics were derived from the collected data allowing the quantification of errors in development time which arise when different sized cohorts are compared through their largest larvae. These errors may be considerable and can lead to overestimation of postmortem intervals when making comparisons with reference data collected from smaller cohorts. This source of error has hitherto been overlooked in forensic entomology.

  18. A computer program for calculating symmetrical aerodynamic characteristics and lateral-directional stability derivatives of wing-body combinations with blowing jets

    NASA Technical Reports Server (NTRS)

    Lan, C. E.; Mehrotra, S. C.; Fox, C. H., Jr.

    1978-01-01

    The necessary information for using a computer program to calculate the aerodynamic characteristics under symmetrical flight conditions and the lateral-directional stability derivatives of wing-body combinations with upper-surface-blowing (USB) or over-wing-blowing (OWB) jets are described. The following new features were added to the program: (1) a fuselage of arbitrary body of revolution has been included. The effect of wing-body interference can now be investigated, and (2) all nine lateral-directional stability derivatives can be calculated. The program is written in FORTRAN language and runs on CDC Cyber 175 and Honeywell 66/60 computers.

  19. Mixtures of amino-acid based ionic liquids and water.

    PubMed

    Chaban, Vitaly V; Fileti, Eudes Eterno

    2015-09-01

    New ionic liquids (ILs) involving increasing numbers of organic and inorganic ions are continuously being reported. We recently developed a new force field; in the present work, we applied that force field to investigate the structural properties of a few novel imidazolium-based ILs in aqueous mixtures via molecular dynamics (MD) simulations. Using cluster analysis, radial distribution functions, and spatial distribution functions, we argue that organic ions (imidazolium, deprotonated alanine, deprotonated methionine, deprotonated tryptophan) are well dispersed in aqueous media, irrespective of the IL content. Aqueous dispersions exhibit desirable properties for chemical engineering. The ILs exist as ion pairs in relatively dilute aqueous mixtures (10 mol%), while more concentrated mixtures feature a certain amount of larger ionic aggregates.

  20. Excess around a central molecule with application to binary mixtures.

    PubMed

    Shulgin, Ivan L; Ruckenstein, Eli

    2008-02-28

    It was shown by us (J. Phys. Chem. B, 2006, 110, 12707) that the excess (deficit) of any species i around a central molecule j in a binary mixture is not provided by c(i)G(ij) (where c(i) is the molar concentration of species i in the mixture and G(ij) are the Kirkwood-Buff integrals) as usually considered and that an additional term, involving a volume V(j) which is inaccessible to molecules of species i because of the presence of the central molecule j, must be included. In this paper, the new expression is applied to various binary mixtures and used to establish a simple criterion for preferential solvation in a binary system. First, it is applied to binary Lennard-Jones fluids. The conventional expression for the excess (deficit) in binary mixtures, c(i)G(ij), provides always deficits around any central molecule in such fluids. In contrast, the new expression provides excess for one species and deficit for the other one. In addition, two kinds of binary mixtures involving weak (argon/krypton) and strong (alcohols/water) intermolecular interactions were considered. Again, the conventional expression for the excess (deficit) in a binary mixture, c(i)G(ij), provides always deficits for any central molecule in the argon/krypton mixture, whereas the new expression provides excess for argon (a somewhat smaller molecule) and deficit for krypton. Three alcohol/water binary mixtures (1-propanol/water, tert-butanol/water and methanol/water) with strong intermolecular interactions were considered and compared with the available experimental information regarding the molecular clustering in solutions. We found (for 1-propanol/water and tert-butanol/water) a large excess of alcohols around a central alcohol molecule and a large excess of water around a central water molecule. For both mixtures the maximum of the calculated excess with respect to the concentration corresponds to the maximum in the cluster size found experimentally, and the range of alcohol concentrations in

  1. MULTIVARIATE KERNEL PARTITION PROCESS MIXTURES

    PubMed Central

    Dunson, David B.

    2013-01-01

    Mixtures provide a useful approach for relaxing parametric assumptions. Discrete mixture models induce clusters, typically with the same cluster allocation for each parameter in multivariate cases. As a more flexible approach that facilitates sparse nonparametric modeling of multivariate random effects distributions, this article proposes a kernel partition process (KPP) in which the cluster allocation varies for different parameters. The KPP is shown to be the driving measure for a multivariate ordered Chinese restaurant process that induces a highly-flexible dependence structure in local clustering. This structure allows the relative locations of the random effects to inform the clustering process, with spatially-proximal random effects likely to be assigned the same cluster index. An exact block Gibbs sampler is developed for posterior computation, avoiding truncation of the infinite measure. The methods are applied to hormone curve data, and a dependent KPP is proposed for classification from functional predictors. PMID:24478563

  2. Combined toxicity of heavy metal mixtures in liver cells.

    PubMed

    Lin, Xialu; Gu, Yuanliang; Zhou, Qi; Mao, Guochuan; Zou, Baobo; Zhao, Jinshun

    2016-09-01

    With rapid industrialization, China is now facing great challenges in heavy metal contamination in the environment. Human exposure to heavy metals through air, water and food commonly involves a mixture consisting of multiple heavy metals. In this study, eight common heavy metals (Pb, Cd, Hg, Cu, Zn, Mn, Cr, Ni) that cause environmental contamination were selected to investigate the combined toxicity of different heavy metal mixtures in HL7702 cells. Toxicity (24 h LC50 ) of each individual metal on the cells ranked Hg > Cr = Cd > Cu > Zn > Ni > Mn > Pb; toxicity of the different mixtures ranked: M5 > M3PbHgCd > M5+Mn > M5+Cu > M2CdNi > M4A > M8-Mn > M8 > M5+Zn > M4B > M8-Cr > M8-Zn > M8-Cu > M8-Pb > M8-Cd > M8-Hg > M8-Ni > M3PbHgNi > M3CuZnMn. The cytotoxicity data of individual metals were successfully used to build the additive models of two- to eight-component metal mixtures. The comparison between additive model and combination model or partly additive model was useful to evaluate the combined effects in mixture. Synergistic, antagonistic or additive effects of the toxicity were observed in different mixtures. These results suggest that the combined effects should be considered in the risk assessment of heavy metal co-exposure, and more comprehensive investigations on the combined effects of different heavy metal mixtures are needed in the future. Copyright © 2016 John Wiley & Sons, Ltd.

  3. Small Scale Evaporation Kinetics of a Binary Fluid Mixture

    NASA Astrophysics Data System (ADS)

    Basdeo, Carl; Ye, Dezhuang; Kalonia, Devendra; Fan, Tai-Hsi; Mechanical Engineering Team; Pharmaceutical Sciences Collaboration

    2013-03-01

    Evaporation induces a concentrating effect in liquid mixtures. The transient process has significant influence on the dynamic behaviors of a complex fluid. To simultaneously investigate the fluid properties and small-scale evaporation kinetics during the transient process, the quartz crystal microbalance is applied to a binary mixture droplet of light alcohols including both a single volatile component (a fast evaporation followed by a slow evaporation) and a mixture of two volatile components with comparable evaporation rates. The density and viscosity stratification are evaluated by the shear wave, and the evaporation kinetics is measured by the resonant signature of the acoustic p-wave. The evaporation flux can be precisely determined by the resonant frequency spikes and the complex impedance. To predict the concentration field, the moving interface, and the precision evaporation kinetics of the mixture, a multiphase model is developed to interpret the complex impedance signals based on the underlying mass and momentum transport phenomena. The experimental method and theoretical model are developed for better characterizing and understanding of the drying process involving liquid mixtures of protein pharmaceuticals.

  4. A Statistical Approach to Optimizing Concrete Mixture Design

    PubMed Central

    Alghamdi, Saeid A.

    2014-01-01

    A step-by-step statistical approach is proposed to obtain optimum proportioning of concrete mixtures using the data obtained through a statistically planned experimental program. The utility of the proposed approach for optimizing the design of concrete mixture is illustrated considering a typical case in which trial mixtures were considered according to a full factorial experiment design involving three factors and their three levels (33). A total of 27 concrete mixtures with three replicates (81 specimens) were considered by varying the levels of key factors affecting compressive strength of concrete, namely, water/cementitious materials ratio (0.38, 0.43, and 0.48), cementitious materials content (350, 375, and 400 kg/m3), and fine/total aggregate ratio (0.35, 0.40, and 0.45). The experimental data were utilized to carry out analysis of variance (ANOVA) and to develop a polynomial regression model for compressive strength in terms of the three design factors considered in this study. The developed statistical model was used to show how optimization of concrete mixtures can be carried out with different possible options. PMID:24688405

  5. New method to predict the surface tension of complex synthetic and biological polyelectrolyte/surfactant mixtures.

    PubMed

    Ábraham, Ágnes; Campbell, Richard A; Varga, Imre

    2013-09-17

    Although the surface tension of complex mixtures determines the fate of many important natural processes, the property is notoriously difficult to interpret. Here we announce a new method that successfully predicts the surface tension of two synthetic and one biological polyelectrolyte/surfactant mixtures in the phase-separation region after dynamic changes in the bulk phase behavior have reached completion. The approach is based on the nonequilibrium framework of a lack of colloidal stability of bulk complexes in compositions around the charge match point of the oppositely charged components and requires as input parameters only the surface tension isotherm of the pure surfactant and some bulk measurements of the mixtures; no surface measurements of the mixtures are required. The complexity of the problem is reduced to a single empirical equation. This simplification in our understanding of the surface properties of strongly interacting mixtures involving macromolecules can lead to the optimization of applications involving synthetic polymers and biomacromolecules such as DNA at surfaces.

  6. Variable mixture ratio performance through nitrogen augmentation

    NASA Technical Reports Server (NTRS)

    Beichel, R.; Obrien, C. J.; Bair, E. K.

    1988-01-01

    High/variable mixture ratio O2/H2 candidate engine cycles are examined for earth-to-orbit vehicle application. Engine performance and power balance information are presented for the candidate cycles relative to chamber pressure, bulk density, and mixture ratio. Included in the cycle screening are concepts where a third fluid (liquid nitrogen) is used to achieve a variable mixture ratio over the trajectory from liftoff to earth orbit. The third fluid cycles offer a very low risk, fully reusable, low operation cost alternative to high/variable mixture ratio bipropellant cycles. Variable mixture ratio engines with extendible nozzle are slightly lower performing than a single mixture ratio engine (MR = 7:1) with extendible nozzle. Dual expander engines (MR = 7:1) have slightly better performance than the single mixture ratio engine. Dual fuel dual expander engines offer a 16 percent improvement over the single mixture ratio engine.

  7. Uncertainty in Mixtures and Cumulative Risk Assessment

    EPA Science Inventory

    Humans and environmental species are rarely exposed to single chemicals. These chemicals typically affect multiple tissues through multiple modes of action, which may depend on the dose. Mixtures risk assessment may employ dose response information from the mixture of interest,...

  8. 21 CFR 82.6 - Certifiable mixtures.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 1 2012-04-01 2012-04-01 false Certifiable mixtures. 82.6 Section 82.6 Food and... PROVISIONALLY LISTED COLORS AND SPECIFICATIONS General Provisions § 82.6 Certifiable mixtures. (a) A batch of a mixture which contains no straight color listed in subpart C or D may be certified for use in food,...

  9. 14 CFR 27.1147 - Mixture controls.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Mixture controls. 27.1147 Section 27.1147... STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Powerplant Controls and Accessories § 27.1147 Mixture controls. If there are mixture controls, each engine must have a separate control and the controls must...

  10. 40 CFR 721.9540 - Polysulfide mixture.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Polysulfide mixture. 721.9540 Section... Substances § 721.9540 Polysulfide mixture. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a polysulfide mixture (PMN P-93-1043)...

  11. 40 CFR 721.9540 - Polysulfide mixture.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Polysulfide mixture. 721.9540 Section... Substances § 721.9540 Polysulfide mixture. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a polysulfide mixture (PMN P-93-1043)...

  12. 40 CFR 721.9540 - Polysulfide mixture.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Polysulfide mixture. 721.9540 Section... Substances § 721.9540 Polysulfide mixture. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a polysulfide mixture (PMN P-93-1043)...

  13. 21 CFR 82.6 - Certifiable mixtures.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Certifiable mixtures. 82.6 Section 82.6 Food and... PROVISIONALLY LISTED COLORS AND SPECIFICATIONS General Provisions § 82.6 Certifiable mixtures. (a) A batch of a mixture which contains no straight color listed in subpart C or D may be certified for use in food,...

  14. 14 CFR 27.1147 - Mixture controls.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Mixture controls. 27.1147 Section 27.1147... STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Powerplant Controls and Accessories § 27.1147 Mixture controls. If there are mixture controls, each engine must have a separate control and the controls must...

  15. 14 CFR 27.1147 - Mixture controls.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Mixture controls. 27.1147 Section 27.1147... STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Powerplant Controls and Accessories § 27.1147 Mixture controls. If there are mixture controls, each engine must have a separate control and the controls must...

  16. 40 CFR 721.9540 - Polysulfide mixture.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Polysulfide mixture. 721.9540 Section... Substances § 721.9540 Polysulfide mixture. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a polysulfide mixture (PMN P-93-1043)...

  17. 14 CFR 27.1147 - Mixture controls.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Mixture controls. 27.1147 Section 27.1147... STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Powerplant Controls and Accessories § 27.1147 Mixture controls. If there are mixture controls, each engine must have a separate control and the controls must...

  18. 14 CFR 25.1147 - Mixture controls.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Mixture controls. 25.1147 Section 25.1147... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Powerplant Controls and Accessories § 25.1147 Mixture controls. (a) If there are mixture controls, each engine must have a separate control. The controls must...

  19. 14 CFR 29.1147 - Mixture controls.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Mixture controls. 29.1147 Section 29.1147... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Powerplant Controls and Accessories § 29.1147 Mixture controls. (a) If there are mixture controls, each engine must have a separate control, and the...

  20. 40 CFR 721.9540 - Polysulfide mixture.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Polysulfide mixture. 721.9540 Section... Substances § 721.9540 Polysulfide mixture. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a polysulfide mixture (PMN P-93-1043)...