Science.gov

Sample records for air blast sprayer

  1. A History of Air-Blast Sprayer Development and Future Prospects

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The design and operating procedures of air-blast sprayers have been greatly improved over the past 50 years. Early tree and vine s pray application equipment used hand-guns that required large amount of water. Later, sprayers with efficient fans, producing large volumes of air at high velocities, ...

  2. Field Hydraulic and Air-Blast Sprayers for Row Crops.

    ERIC Educational Resources Information Center

    Cole, Herbert, Jr., Comp.

    This agriculture extension service publication from Pennsylvania State University discusses techniques and equipment used in spraying field crops. In the discussion of field hydraulic sprayers, specific topics include types of sprayers, tanks, pumps, pressure regulators, hoses, boom spraying, directed spraying, and nozzle bodies. In the discussion…

  3. Fungicide spray coverage from ground-based sprayers in mature pecan trees

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Air-blast sprayers are widely used to control pecan scab (Fusicladium effusum) on pecan trees. Good spray coverage is critical to ensure disease control and to minimize risk of fungicide resistance. Spray coverage from an air-blast sprayer, typical of the sprayer used by commercial producers, was me...

  4. Unimpeded air velocity profiles of air-assisted five-port sprayer

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A capability that relies on tree structure information to control liquid and air flow rates is the preferential design in the development of variable-rate orchard and nursery sprayers. Unimpeded air jet velocities from an air assisted, five-port sprayer in an open field were measured at four height...

  5. Air velocity distributions from a variable-rate air-assisted sprayer for tree applications

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A capability that implements tree structure to control liquid and air flow rates is the preferential design in the development of variable-rate orchard and nursery sprayers. Air jet velocity distributions from an air assisted, five-port sprayer which was under the development to achieve variable-rat...

  6. Air velocity distributions from air-assisted five-port sprayer

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Capability to control both liquid and air flow rates based on tree structures would be one of the advantages of future variable-rate orchard and nursery sprayers. Air jet velocity distributions from an air assisted, five-port sprayer which was under the development to achieve variable-rate functions...

  7. Spray drift and off-target loss reduction with a precision air-assisted sprayer

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Spray drift and off-target losses are inherent problems of conventional air-assisted sprayers. Their low efficiencies cause environmental pollutions resulting in public anxieties. A new drift reduction technology incorporating laser scanning capabilities with a variable-rate air-assisted sprayer w...

  8. Efficacious insect and disease control with laser-guided air-assisted sprayer

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Efficacy of a newly developed air-assisted variable-rate sprayer was investigated for the control of arthropod pests and plant diseases in six commercial fields. The sprayer was integrated with a high-speed laser scanning sensor, a custom-designed signal processing program, an automatic flow control...

  9. Dislodgeable azinphosmethyl residues from air blast spraying of apple foliage in Ohio.

    PubMed

    Hall, F R; Reichard, D L; Krueger, H R

    1975-01-01

    The distribution and decay rates of dislodgeable residues of azinphosmethyl applied by two types of air blast sprayers on apple foliage in Ohio were investigated. Leaf discs were taken from nine sites located on the periphery of Cortland apple trees at five dates after spraying. The sprayer delivering the higher airflow rate, but lower velocity, deposited the pesticide much more uniformly over the trees and applied more in the top of the tree. The other sprayer deposited the greatest proportion of pesticide on the site nearest the sprayer. The residue decreased at all sites and ranged from 42 to near 100% decrease at 14 days after spraying.

  10. Characterization of air profiles impeded by plant canopies for a variable-rate air-assisted sprayer

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The preferential design for variable-rate orchard and nursery sprayers relies on tree structure to control liquid and air flow rates. Demand for this advanced feature has been incremental as the public demand on reduction of pesticide use. A variable-rate, air assisted, five-port sprayer had been in...

  11. Air Assisted Sprayer for Improved Spray Penetration in Greenhouse Floriculture Crops

    NASA Astrophysics Data System (ADS)

    Wandkar, Sachin V.; Mathur, Shailendra M.; Dhande, Kishor G.; Jadhav, Pravin P.; Gholap, Babasaheb S.

    2015-03-01

    Air assisted spraying is considered as one of the better pesticide application technique. Incorporation of air assistance in the spraying system improves the deposition uniformity in the entire plant canopy structure and spray deposition on the lower part of the plant leaves. In the view of this, an air assisted sleeve boom sprayer was developed for greenhouse floricultural crops. The developed sprayer consisted of air delivery system and spray delivery system. Air delivery system consisted of blower, lance assembly and a tapered air sleeve. Spray delivery system consisted of a pesticide tank, horizontal triplex pump, pressure hose and nozzles. Blower and pump were operated by 5 HP electric motor. Air sleeve and nozzles were supported on horizontal boom. The whole assembly of the sprayer was mounted on the trolley. The developed sprayer was tested in the laboratory to study the effect of different air velocity (9, 12, 16 and 20 m/s) and pump discharge (2.5, 4.5, 7 and 9 L/min) levels on droplet size (VMD), droplet density and uniformity coefficient at six different positions of the artificial plant canopy. Test results revealed that an increase in air velocity resulted in better spray penetration and uniform spray coverage. The optimum results of droplet size (100-150 µm), droplet density (25-35 droplets per cm2) and uniformity coefficient at all plant positions were observed for air velocity of 20 m/s and pump discharge of 2.5 L/min.

  12. Analysis of the air flow generated by an air-assisted sprayer equipped with two axial fans using a 3D sonic anemometer.

    PubMed

    García-Ramos, F Javier; Vidal, Mariano; Boné, Antonio; Malón, Hugo; Aguirre, Javier

    2012-01-01

    The flow of air generated by a new design of air assisted sprayer equipped with two axial fans of reversed rotation was analyzed. For this goal, a 3D sonic anemometer has been used (accuracy: 1.5%; measurement range: 0 to 45 m/s). The study was divided into a static test and a dynamic test. During the static test, the air velocity in the working vicinity of the sprayer was measured considering the following machine configurations: (1) one activated fan regulated at three air flows (machine working as a traditional sprayer); (2) two activated fans regulated at three air flows for each fan. In the static test 72 measurement points were considered. The location of the measurement points was as follow: left and right sides of the sprayer; three sections of measurement (A, B and C); three measurement distances from the shaft of the machine (1.5 m, 2.5 m and 3.5 m); and four measurement heights (1 m, 2 m, 3 m and 4 m). The static test results have shown significant differences in the module and the vertical angle of the air velocity vector in function of the regulations of the sprayer. In the dynamic test, the air velocity was measured at 2.5 m from the axis of the sprayer considering four measurement heights (1 m, 2 m, 3 m and 4 m). In this test, the sprayer regulations were: one or two activated fans; one air flow for each fan; forward speed of 2.8 km/h. The use of one fan (back) or two fans (back and front) produced significant differences on the duration of the presence of wind in the measurement point and on the direction of the air velocity vector. The module of the air velocity vector was not affected by the number of activated fans.

  13. Analysis of the Air Flow Generated by an Air-Assisted Sprayer Equipped with Two Axial Fans Using a 3D Sonic Anemometer

    PubMed Central

    García-Ramos, F. Javier; Vidal, Mariano; Boné, Antonio; Malón, Hugo; Aguirre, Javier

    2012-01-01

    The flow of air generated by a new design of air assisted sprayer equipped with two axial fans of reversed rotation was analyzed. For this goal, a 3D sonic anemometer has been used (accuracy: 1.5%; measurement range: 0 to 45 m/s). The study was divided into a static test and a dynamic test. During the static test, the air velocity in the working vicinity of the sprayer was measured considering the following machine configurations: (1) one activated fan regulated at three air flows (machine working as a traditional sprayer); (2) two activated fans regulated at three air flows for each fan. In the static test 72 measurement points were considered. The location of the measurement points was as follow: left and right sides of the sprayer; three sections of measurement (A, B and C); three measurement distances from the shaft of the machine (1.5 m, 2.5 m and 3.5 m); and four measurement heights (1 m, 2 m, 3 m and 4 m). The static test results have shown significant differences in the module and the vertical angle of the air velocity vector in function of the regulations of the sprayer. In the dynamic test, the air velocity was measured at 2.5 m from the axis of the sprayer considering four measurement heights (1 m, 2 m, 3 m and 4 m). In this test, the sprayer regulations were: one or two activated fans; one air flow for each fan; forward speed of 2.8 km/h. The use of one fan (back) or two fans (back and front) produced significant differences on the duration of the presence of wind in the measurement point and on the direction of the air velocity vector. The module of the air velocity vector was not affected by the number of activated fans. PMID:22969363

  14. Validation of a CFD model by using 3D sonic anemometers to analyse the air velocity generated by an air-assisted sprayer equipped with two axial fans.

    PubMed

    García-Ramos, F Javier; Malón, Hugo; Aguirre, A Javier; Boné, Antonio; Puyuelo, Javier; Vidal, Mariano

    2015-01-22

    A computational fluid dynamics (CFD) model of the air flow generated by an air-assisted sprayer equipped with two axial fans was developed and validated by practical experiments in the laboratory. The CFD model was developed by considering the total air flow supplied by the sprayer fan to be the main parameter, rather than the outlet air velocity. The model was developed for three air flows corresponding to three fan blade settings and assuming that the sprayer is stationary. Actual measurements of the air velocity near the sprayer were taken using 3D sonic anemometers. The workspace sprayer was divided into three sections, and the air velocity was measured in each section on both sides of the machine at a horizontal distance of 1.5, 2.5, and 3.5 m from the machine, and at heights of 1, 2, 3, and 4 m above the ground The coefficient of determination (R2) between the simulated and measured values was 0.859, which demonstrates a good correlation between the simulated and measured data. Considering the overall data, the air velocity values produced by the CFD model were not significantly different from the measured values.

  15. Validation of a CFD Model by Using 3D Sonic Anemometers to Analyse the Air Velocity Generated by an Air-Assisted Sprayer Equipped with Two Axial Fans

    PubMed Central

    García-Ramos, F. Javier; Malón, Hugo; Aguirre, A. Javier; Boné, Antonio; Puyuelo, Javier; Vidal, Mariano

    2015-01-01

    A computational fluid dynamics (CFD) model of the air flow generated by an air-assisted sprayer equipped with two axial fans was developed and validated by practical experiments in the laboratory. The CFD model was developed by considering the total air flow supplied by the sprayer fan to be the main parameter, rather than the outlet air velocity. The model was developed for three air flows corresponding to three fan blade settings and assuming that the sprayer is stationary. Actual measurements of the air velocity near the sprayer were taken using 3D sonic anemometers. The workspace sprayer was divided into three sections, and the air velocity was measured in each section on both sides of the machine at a horizontal distance of 1.5, 2.5, and 3.5 m from the machine, and at heights of 1, 2, 3, and 4 m above the ground The coefficient of determination (R2) between the simulated and measured values was 0.859, which demonstrates a good correlation between the simulated and measured data. Considering the overall data, the air velocity values produced by the CFD model were not significantly different from the measured values. PMID:25621611

  16. Influence of travel speed on spray deposition uniformity from an air-assisted variable-rate sprayer

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A newly developed LiDAR-guided air-assisted variable-rate sprayer for nursery and orchard applications was tested at various travel speeds to compare its spray deposition and coverage uniformity with constant-rate applications. Spray samplers, including nylon screens and water-sensitive papers (WSP)...

  17. Embedded computer controlled premixing inline injection system for air-assisted variable-rate sprayers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Improvements to reduce chemical waste and environmental pollution for variable-rate sprayers used in orchards and ornamental nurseries require inline injection techniques. A microprocessor controlled premixing inline injection system implementing a ceramic piston chemical metering pump and two small...

  18. Canopy penetration and deposition of barrier sprays from electrostatic and conventional sprayers.

    PubMed

    Hoffmann, W C; Farooq, M; Walker, T W; Fritz, B; Szumlas, D; Quinn, B; Bernier, U; Hogsette, J; Lan, Y; Huang, Y; Smith, V L; Robinson, C A

    2009-09-01

    An experimental study was conducted to investigate the usefulness of electrostatic and conventional sprayers for barrier applications. Two conventional and three electrostatic sprayers were used in the study. Usefulness of the sprayers was rated based on penetration of spray into and deposition onto 2 sides of leaves on natural vegetation. Bifenthrin (Talstar adulticide) was applied at labeled rate, fluorescent dye was added to the tank mix as tracer, and all sprayers applied the dye and insecticide at the same rate. The results indicated that sprayers producing larger droplets produced significantly higher deposition on vegetation in barrier applications than the sprayers producing smaller droplets. Sprayers with higher air velocity at the nozzle discharge proved significantly better for barrier sprays than the sprayers with lower air velocity. Electrostatic sprayers did not show any improvement in deposition on vegetation or in penetration into vegetation over the conventional sprayers. There was no difference in deposition between truck-mounted and backpack sprayers. PMID:19852223

  19. Comparing greenhouse sprayers: the dose-transfer process.

    PubMed

    Ebert, Timothy A; Derksen, Richard C; Downer, Roger A; Krause, Charles R

    2004-05-01

    Three sprayers were evaluated for their affect on retention and efficacy: a carbon dioxide powered high-volume sprayer, a DRAMM coldfogger, and an Electrostatic Spraying Systems (ESS) sprayer with air-assistance. The active ingredients used were spinosad and azadirachtin. The plant canopy was constructed in the greenhouse using potted soybeans (Glycine max (L) Merrill cr Pioneer 9392). Application efficacy with spinosad was assessed using thrips [Western flower thrips, Frankliniella occidentalis (Pergande)] and mite (two-spotted spider mite, Tetranychus urticae Koch) abundance on shoots and leaves. Application efficacy with azadirachtin was assessed using thrips and aphid (soybean aphid, Aphis glycines Matsumura) abundance on shoots and leaves. The atomization characteristics of each sprayer were measured using an Aerometrics phase/Doppler particle analyzer (PDPA) 100-1D. The results of four tests are presented. Two tests used each sprayer according to manufacturer recommendations. These are 'recommended volume' tests that confound differences in toxicant distribution caused by the sprayer with differences caused by changes in application volume. The other two tests were 'constant volume' tests in which all three sprayers were used to deliver the same application volume. Both types of test gave differences between sprayers in retention of toxicant, but only the recommended volume tests showed significant effects of the sprayers on pest abundance. We attribute this difference to the role played by changing application volumes in the dose-transfer process. The constant-volume tests showed that application equipment influences efficacy.

  20. A Blast of Cool Air

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Unable to solve their engineering problem with a rotor in their Orbital Vane product, DynEco Corporation turned to Kennedy Space Center for help. KSC engineers determined that the compressor rotor was causing a large concentration of stress, which led to cracking and instant rotor failure. NASA redesigned the lubrication system, which allowed the company to move forward with its compressor that has no rubbing parts. The Orbital Vane is a refrigerant compressor suitable for mobile air conditioning and refrigeration.

  1. 7. Air Blast Circuit Breaker Compressors, view to the southeast. ...

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

    7. Air Blast Circuit Breaker Compressors, view to the southeast. The air blast circuit breakers are visible in the left background of the photograph. - Washington Water Power Clark Fork River Noxon Rapids Hydroelectric Development, Powerhouse, South bank of Clark Fork River at Noxon Rapids, Noxon, Sanders County, MT

  2. 6. OUTER BLAST DOOR, WEST REAR. Edwards Air Force ...

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

    6. OUTER BLAST DOOR, WEST REAR. - Edwards Air Force Base, South Base Sled Track, Firing & Control Blockhouse for 10,000-foot Track, South of Sled Track at midpoint of 20,000-foot track, Lancaster, Los Angeles County, CA

  3. Explosively driven air blast in a conical shock tube

    NASA Astrophysics Data System (ADS)

    Stewart, Joel B.; Pecora, Collin

    2015-03-01

    Explosively driven shock tubes present challenges in terms of safety concerns and expensive upkeep of test facilities but provide more realistic approximations to the air blast resulting from free-field detonations than those provided by gas-driven shock tubes. Likewise, the geometry of conical shock tubes can naturally approximate a sector cut from a spherically symmetric blast, leading to a better agreement with the blast profiles of free-field detonations when compared to those provided by shock tubes employing constant cross sections. The work presented in this article documents the design, fabrication, and testing of an explosively driven conical shock tube whose goal was to closely replicate the blast profile seen from a larger, free-field detonation. By constraining the blast through a finite area, large blasts (which can add significant damage and safety constraints) can be simulated using smaller explosive charges. The experimental data presented herein show that a close approximation to the free-field air blast profile due to a 1.5 lb charge of C4 at 76 in. can be achieved by using a 0.032 lb charge in a 76-in.-long conical shock tube (which translates to an amplification factor of nearly 50). Modeling and simulation tools were used extensively in designing this shock tube to minimize expensive fabrication costs.

  4. Explosively driven air blast in a conical shock tube

    SciTech Connect

    Stewart, Joel B. Pecora, Collin

    2015-03-15

    Explosively driven shock tubes present challenges in terms of safety concerns and expensive upkeep of test facilities but provide more realistic approximations to the air blast resulting from free-field detonations than those provided by gas-driven shock tubes. Likewise, the geometry of conical shock tubes can naturally approximate a sector cut from a spherically symmetric blast, leading to a better agreement with the blast profiles of free-field detonations when compared to those provided by shock tubes employing constant cross sections. The work presented in this article documents the design, fabrication, and testing of an explosively driven conical shock tube whose goal was to closely replicate the blast profile seen from a larger, free-field detonation. By constraining the blast through a finite area, large blasts (which can add significant damage and safety constraints) can be simulated using smaller explosive charges. The experimental data presented herein show that a close approximation to the free-field air blast profile due to a 1.5 lb charge of C4 at 76 in. can be achieved by using a 0.032 lb charge in a 76-in.-long conical shock tube (which translates to an amplification factor of nearly 50). Modeling and simulation tools were used extensively in designing this shock tube to minimize expensive fabrication costs.

  5. Detailed Comparison of Blast Effects in Air and Vacuum

    SciTech Connect

    Tringe, J W; Molitoris, J D; Garza, R G; Andreski, H G; Batteux, J D; Lauderbach, L M; Vincent, E R; Wong, B M

    2007-07-26

    Although blast mitigation is most often achieved with solid shielding, ambient gas pressure can also affect the coupling of shock waves to solid targets. In this work the role of air as an energy transfer medium was examined experimentally by subjecting identical large-area rectangular witness plates to short-range blast effects in air and vacuum ({approx}50 mtorr) at 25 C. The expanding reactant front of 3 kg C4 charges was observed by fast camera to be cylindrically symmetric in both air and vacuum. The horizontal component of the reactant cloud velocity (perpendicular to the witness plates) was constant in both cases, with values of 3.0 and 5.9 km/s for air and vacuum, respectively. As a result of the blast, witness plates were plastically deformed into a shallow dish geometry, with local maxima 30 and 20 mm deep for air and vacuum, respectively. The average plate deflection from the air blast was 11 mm, {approx}10% deeper than the average vacuum plate deflection. Shock pressure estimates were made with a simple impedance-matching model, and indicate peak values in the 30-50 MPa range are consistent with the reactant cloud density and velocity. However, more detailed analysis is necessary to definitely establish the mechanisms by which air couples shock energy to the plates.

  6. Development of laser-guided precision sprayers for tree crop applications

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tree crops in nurseries and orchards have great variations in shapes, sizes, canopy densities and gaps between in-row trees. The variability requires future sprayers to be flexible to spray the amount of chemicals that can match tree structures. A precision air-assisted sprayer was developed to appl...

  7. Detailed Comparison of Blast Effects in Air and Vacuum

    NASA Astrophysics Data System (ADS)

    Tringe, J. W.; Molitoris, J. D.; Garza, R. G.; Andreski, H. G.; Batteux, J. D.; Lauderbach, L. M.; Vincent, E. R.; Wong, B. M.

    2007-12-01

    The role of air as an energy transfer medium was examined experimentally by subjecting identical large-area rectangular witness plates to short-range blast effects in air and vacuum (˜50 mtorr) at 25 °C. The expanding reactant front of 3 kg C4 charges was observed by fast camera to be cylindrically symmetric in both air and vacuum. The horizontal component of the reactant cloud velocity (perpendicular to the witness plates) was constant in both cases, with values of 3.0 and 5.9 km/s for air and vacuum, respectively. As a result of the blast, witness plates were plastically deformed into a shallow dish geometry, with local maxima 30 and 20 mm deep for air and vacuum, respectively. The average plate deflection from the air blast was 11 mm, ˜10% deeper than the average vacuum plate deflection. Shock pressure estimates were made with a simple impedance-matching model, and indicate peak values in the 30-50 MPa range are consistent with the reactant cloud density and velocity. However, more detailed analysis is necessary to better understand the time-dependent coupling of shock energy that plastically deforms the plates.

  8. Plastic media blasting activities at Hill Air Force Base

    NASA Astrophysics Data System (ADS)

    Christensen, J. D.

    1993-03-01

    Hill Air Force Base in Utah developed plastic media blasting (PMB) paint removal process for removing paint from Air Force aircraft. The development of the process involved extensive testing of various abrasives and subsequent parameters to end up with an approved production process. Hill AFB has been using PMB in a production mode since 1985, and completely discontinued chemical stripping of airframes in 1989. We have recently installed and began operating a fully automated PMB facility that utilizes two nine-axis robots to strip an aircraft. This system has enabled us to further reduce the manhours required to strip an aircraft, and also allowed us to remove the employee from the blasting atmosphere into a control room. We have, and will continue to realize, significant environmental and economic savings by using PMB. Hill is also actively involved with the development of future paint stripping technologies.

  9. Air blast type coal slurry fuel injector

    DOEpatents

    Phatak, R.G.

    1984-08-31

    A device to atomize and inject a coal slurry in the combustion chamber of an internal combustion engine is disclosed which eliminates the use of a conventional fuel injection pump/nozzle. The injector involves the use of compressed air to atomize and inject the coal slurry and like fuels. In one embodiment, the breaking and atomization of the fuel is achieved with the help of perforated discs and compressed air. In another embodiment, a cone shaped aspirator is used to achieve the breaking and atomization of the fuel. The compressed air protects critical bearing areas of the injector.

  10. Air blast type coal slurry fuel injector

    DOEpatents

    Phatak, Ramkrishna G.

    1986-01-01

    A device to atomize and inject a coal slurry in the combustion chamber of an internal combustion engine, and which eliminates the use of a conventional fuel injection pump/nozzle. The injector involves the use of compressed air to atomize and inject the coal slurry and like fuels. In one embodiment, the breaking and atomization of the fuel is achieved with the help of perforated discs and compressed air. In another embodiment, a cone shaped aspirator is used to achieve the breaking and atomization of the fuel. The compressed air protects critical bearing areas of the injector.

  11. Numerical Simulations of Blast Loads from Near-Field Ground Explosions in Air

    NASA Astrophysics Data System (ADS)

    Dobrociński, Stanisław; Flis, Leszek

    2015-12-01

    Numerical simulations of air blast loading in the near-field acting on the ground have been performed. A simplified blast model based on empirical blast loading data representing spherical and hemispherical explosive shapes has been simulated. Conwep is an implementation of the empirical blast models presented by Kingery and Bulmash, which is also implemented in the commercial code LS-DYNA based on work done by Rahnders-Pehrson and Bannister. This makes it possible to simulate blast loads acting on structures representing spherical and hemispherical explosive shapes of TNT with reasonable computational effort as an alternative to the SPH and Eulerian model. The CPU time for the simplified blast model is however considerably shorter and may still be useful in time consuming concept studies. Reasonable numerical results using reasonable model sizes can be achieved not only for modelling near-field explosions in air but most areas of geotechnical. Calculation was compared with blast SPH and Eulerian model.

  12. The Air Blast Wave from a Nuclear Explosion

    NASA Astrophysics Data System (ADS)

    Reines, Frederick

    The sudden, large scale release of energy in the explosion of a nuclear bomb in air gives rise, in addition to nuclear emanations such as neutrons and gamma rays, to an extremely hot, rapidly expanding mass of air.** The rapidly expanding air mass has an initial temperature in the vicinity of a few hundred thousand degrees and for this reason it glows in its early stages with an intensity of many suns. It is important that the energy density in this initial "ball of fire" is of the order of 3 × 103 times that found in a detonating piece of TNT and hence that the initial stages of the large scale air motion produced by a nuclear explosion has no counterpart in an ordinary. H. E. explosion. Further, the relatively low temperatures ˜2,000°C associated with the initial stages of an H. E. detonation implies that the thermal radiation which it emits is a relatively insignificant fraction of the total energy involves. This point is made more striking when it is remembered that the thermal energy emitted by a hot object varies directly with the temperature in the Rayleigh Jeans region appropriate to the present discussion. The expansion of the air mass heated by the nuclear reaction produces, in qualitatively the same manner as in an H.E. explosion or the bursting of a high pressure balloon, an intense sharp pressure pulse, a shock wave, in the atmosphere. As the pressure pulse spreads outward it weakens due to the combined effects of divergence and the thermodynamically irreversible nature of the shock wave. The air comprising such a pressure pulse or blast wave moves first radially outward and then back towards the center as the blast wave passes. Since a permanent outward displacement of an infinite mass of air would require unlimited energy, the net outward displacement of the air distant from an explosion must approach zero with increasing distance. As the distance from the explosion is diminished the net outward displacement due to irreversible shock heating of

  13. Experiments on cylindrically converging blast waves in atmospheric air

    NASA Astrophysics Data System (ADS)

    Matsuo, Hideo; Nakamura, Yuichi

    1980-06-01

    Cylindrically converging blast waves have been produced in normal atmospheric conditions by the detonation of the explosives, pentaerythritoltetranitrate, (PETN), over cylindrical surfaces. The shocks generated in this way are so strong that the fronts propagating through the air become luminous of themselves. The production and the propagation of the shocks have been monitored with a framing camera and a streak camera, and the time-space relations of the shock propagations have been determined using an electrical ionization probing system. The results have shown that the trajectory of the shock fronts near the axis of the cylinder can be approximately represented by the Guderley's formula.

  14. Liver disease in vineyard sprayers.

    PubMed

    Pimentel, J C; Menezes, A P

    1977-02-01

    Liver disease with inclusions of copper was recognized among 30 rural workers with "vineyard sprayer's lung." The pathological findings were varied: focal or diffuse swelling and proliferation of Kupffer cells; histiocytic and sarcoid-like granulomata; fibrosis of variable degree in the perisinusoidal, portal, and subcapsular areas, accompanied by atypical proliferation of the sinusoidal lining cells; micronodular cirrhosis; angiosarcoma of the liver; idiopathic portal hypertension. Abundant deposits of copper were revealed by histochemical techniques within hepatic and pulmonary lesions in these patients. The observations on the human and experimental material suggest an etiological relationship between exposure to copper sulfate and the lesions described. A morphological resemblance was noted between the "liver disease of vineyard sprayers" and the hepatic lesions reported in workers exposed to inorganic arsenic and to vinyl chloride. The identification of the inhaled foreign material within the liver lesions raises important etiological considerations.

  15. Numerical Analysis of the Effects of Wind and Sprayer Type on Spray Distribution in Different Orchard Training Systems

    NASA Astrophysics Data System (ADS)

    Duga, Ashenafi T.; Dekeyser, Donald; Ruysen, Kris; Bylemans, Dany; Nuyttens, David; Nicolai, Bart M.; Verboven, Pieter

    2015-12-01

    A computational fluid dynamics (CFD) model of airflow and spray application in orchards was validated using field trials and used to assess the effect of wind and sprayer type on spray distribution in different orchard training systems. Three air-assisted orchard sprayer designs (a cross-flow sprayer, an axial sprayer and a sprayer with individual spouts) and four different training systems of apple and pear trees were used for this analysis. The CFD model integrates the tree architecture into the model geometry, rather than using a generalized canopy profile approach. Predicted vertical on-tree deposition profiles agreed well with measurements. The lower airflow rate generated by the sprayer with individual spouts resulted in a significantly larger deflection of the spray particles under the same wind conditions. A detailed assessment was made on the most common axial sprayer. An increase in the magnitude of the wind speed for flow across the tree row resulted in an increase in the amount of spray detected in the air around the trees and in the ground deposition in front of the tree row. Environmental airflow in the direction of spraying gave the largest deposition on the tree, constraining the spray in the canopy region. A wind direction opposite to the spraying direction, however, resulted in an increase of the ground deposition and the amount of spray remaining in air. The model can be used to analyze the effects of implementation of more sustainable spray application procedures taking into account wind conditions, tree and machine characteristics.

  16. Modelling the Effect of Tree Foliage on Sprayer Airflow in Orchards

    NASA Astrophysics Data System (ADS)

    Melese Endalew, Ayenew; Debaer, Christof; Rutten, Nick; Vercammen, Jef; Delele, Mulugeta Admasu; Ramon, Herman; Nicolaï, Bart M.; Verboven, Pieter

    2011-01-01

    The effect of tree foliage on sprayer airflow through pear trees in a fruit orchard was studied and modelled in detail. A new three-dimensional (3-D) computational fluid dynamics model that integrates the 3-D canopy architecture with a local closure model to simulate the effect of the stem and branches and leaves of trees separately on airflow was developed. The model was validated with field observations made in an experimental orchard (pcfruit, Sint-Truiden, Belgium) in spring and summer 2008 and was used to investigate the airflow from three air-assisted orchard sprayers (Condor V, Duoprop and AirJet quatt). Velocity magnitudes were measured before and behind leafless and fully-leafed pear canopies across the row while the operating sprayers are passing along the row, and were compared with the simulations. The simulation results predicted the measured values well with all the local relative errors within 20%. The effect of foliar density on airflow from the three air assisted sprayers was manifested by changing the magnitude and direction of the sprayers' air velocity behind the canopy, especially at the denser regions of the canopy and by changing the pattern of velocity decay horizontally along the jet. The developed methodology will also allow a thorough investigation of atmospheric airflow in canopy structures.

  17. Computer Simulation of Blast Wall Protection under Methane-Air Explosion on an Offshore Platform

    NASA Astrophysics Data System (ADS)

    Wang, Changjian; Yan, Weigang; Guo, Jin; Guo, Changming

    An in-house explosion program is presented to evaluate blast wall protection under Methane-Air Explosion on an offshore platform, based on two-dimensional, time-dependent, reactive Navier-Stokes equations including the effects of viscosity, thermal conduction and molecular diffusion. The results show that this program can successfully produce explosion process of methane-air gas cloud. Because the overpressure behind the blast wall and on the lifeboat plate is more than 1.0atm when explosion wave passes, the current blast wall is not enough to keep the person and lifeboat safe. So the blast wall needs to be re-designed. The explosion wave of methane-air gas cloud undergoes a successive process of detonation formation, detonation transmission, shock attenuation, regular reflection and Mach reflection etc. Additionally, due to high overpressure generated in gas cloud explosion, it is extremely devastating and must be avoided at all times on offshore platform.

  18. Droplet Breakup Mechanisms in Air-blast Atomizers

    NASA Astrophysics Data System (ADS)

    Aliabadi, Amir Abbas; Taghavi, Seyed Mohammad; Lim, Kelly

    2011-11-01

    Atomization processes are encountered in many natural and man-made phenomena. Examples are pollen release by plants, human cough or sneeze, engine fuel injectors, spray paint and many more. The physics governing the atomization of liquids is important in understanding and utilizing atomization processes in both natural and industrial processes. We have observed the governing physics of droplet breakup in an air-blast water atomizer using a high magnification, high speed, and high resolution LASER imaging technique. The droplet breakup mechanisms are investigated in three major categories. First, the liquid drops are flattened to form an oblate ellipsoid (lenticular deformation). Subsequent deformation depends on the magnitude of the internal forces relative to external forces. The ellipsoid is converted into a torus that becomes stretched and disintegrates into smaller drops. Second, the drops become elongated to form a long cylindrical thread or ligament that break up into smaller drops (Cigar-shaped deformation). Third, local deformation on the drop surface creates bulges and protuberances that eventually detach themselves from the parent drop to form smaller drops.

  19. The Effect of Charge Reactive Metal Cases on Air Blast

    NASA Astrophysics Data System (ADS)

    Zhang, Fan; Wilson, William

    2009-06-01

    Experiments were conducted in a 23 m^3 closed chamber using explosive encased in a cylindrical reactive metal case to study the effect on air blast from the case fragments. Parameters varied included explosive material, case material, case/explosive mass ratio and charge internal diameter, which ranged from 7.62 to 12.7 cm. The pressure histories measured on the chamber wall showed a double-shock front structure with an accelerating precursor shock followed by the primary shock, suggesting the early-time reaction of small case fragments. During the early reflections on the chamber wall, the pressure rise achieves a factor of 1.6 versus the steel-cased and a factor of 1.2-1.4 versus the bare charges, indicating combustion of a large amount of small case particles generated by secondary fragmentation. The analysis of explosion pressures and recovered fragments and solid products showed that the burnt case mass increases with detonation pressure and case/explosion mass ratio over a test range from 0.29 to 1.75 in a quadratic function. The influences of charge diameter and various reactive metal cases on the burnt case mass are further investigated.

  20. The Effect of Charge Reactive Metal Cases on Air Blast

    NASA Astrophysics Data System (ADS)

    Zhang, Fan; Wilson, William H.

    2009-12-01

    Experiments were conducted in a 23 m3 closed chamber using a charge encased in a cylindrical reactive metal case to study the effect on air blast from the case fragments. Parameters varied included case/charge mass ratio, charge diameter and charge type (i.e., detonation energy and pressure). The pressure histories measured on the chamber wall showed a double-shock front structure with an accelerating precursor shock followed by the primary shock, suggesting the early-time reaction of small case fragments. During the early reflections on the chamber wall, significant pressure rises versus the steel-cased and bare charges indicated combustion of a large amount of small case particles generated by secondary fragmentation. The analysis of explosion pressures and recovered fragments and solid products gave an expression for burnt casing mass as a function of Gurney velocity and charge diameter. The equivalent bare charge mass that yields the same explosion pressure as the cased charge increased with case/charge mass ratio and reached 2.5 times charge mass at the ratio of 1.75.

  1. Impact of electrostatic and conventional sprayers characteristics on dispersion of barrier spray.

    PubMed

    Farooq, Muhammad; Walker, Todd W; Heintschel, Bryan P; Hoffmann, Wesley C; Fritz, Bradley K; Smith, Vincent L; Robinson, Cathy A; English, Trey

    2010-12-01

    A study was conducted to analyze the performance of 3 electrostatic (Electrolon BP-2.5, Spectrum Electrostatic 4010, and Spectrum Electrostatic head on a Stihl 420) and 2 conventional (Buffalo Turbine CSM2 and Stihl 420) sprayers for barrier sprays to suppress an adult mosquito population in an enclosed area. Sprayer characteristics such as charge-mass ratio, air velocity, flow rate, and droplet spectra were measured while spraying water. Dispersion of the spray cloud from these sprayers was determined using coverage on water-sensitive cards at various heights (0.5 m, 1.0 m, 1.5 m, 2.0 m, 2.5 m, and 3.0 m) and depths (1 m, 3 m, and 5 m) into the under-forest vegetation while spraying bifenthrin (Talstar 7.9% AI; FMC Corporation, Philadelphia, PA) at the rate of 21.8 ml/300 m of treated row. The charge-mass ratio data show that Electrostatic head on a Stihl 420 did not impart enough charge to the droplets to be considered as an electrostatic sprayer. In general, the charged spray cloud moved down toward the ground. The Electrolon BP 2.5 had significantly lower spray coverage on cards, indicating lack of spray dispersion. This sprayer had the lowest air velocity and did not have the air capacity needed to deliver droplets close to the target for electrostatic force to affect deposition. The analysis shows that these 2 sprayers are not a suitable choice for barrier sprays on vegetation. The results indicate that the Buffalo Turbine is suitable for barriers wider than 3 m, and the Spectrum 4010 and Stihl 420 are suitable for 1-3-m-wide barriers.

  2. Prediction of blast-induced air overpressure: a hybrid AI-based predictive model.

    PubMed

    Jahed Armaghani, Danial; Hajihassani, Mohsen; Marto, Aminaton; Shirani Faradonbeh, Roohollah; Mohamad, Edy Tonnizam

    2015-11-01

    Blast operations in the vicinity of residential areas usually produce significant environmental problems which may cause severe damage to the nearby areas. Blast-induced air overpressure (AOp) is one of the most important environmental impacts of blast operations which needs to be predicted to minimize the potential risk of damage. This paper presents an artificial neural network (ANN) optimized by the imperialist competitive algorithm (ICA) for the prediction of AOp induced by quarry blasting. For this purpose, 95 blasting operations were precisely monitored in a granite quarry site in Malaysia and AOp values were recorded in each operation. Furthermore, the most influential parameters on AOp, including the maximum charge per delay and the distance between the blast-face and monitoring point, were measured and used to train the ICA-ANN model. Based on the generalized predictor equation and considering the measured data from the granite quarry site, a new empirical equation was developed to predict AOp. For comparison purposes, conventional ANN models were developed and compared with the ICA-ANN results. The results demonstrated that the proposed ICA-ANN model is able to predict blast-induced AOp more accurately than other presented techniques. PMID:26433903

  3. Prediction of blast-induced air overpressure: a hybrid AI-based predictive model.

    PubMed

    Jahed Armaghani, Danial; Hajihassani, Mohsen; Marto, Aminaton; Shirani Faradonbeh, Roohollah; Mohamad, Edy Tonnizam

    2015-11-01

    Blast operations in the vicinity of residential areas usually produce significant environmental problems which may cause severe damage to the nearby areas. Blast-induced air overpressure (AOp) is one of the most important environmental impacts of blast operations which needs to be predicted to minimize the potential risk of damage. This paper presents an artificial neural network (ANN) optimized by the imperialist competitive algorithm (ICA) for the prediction of AOp induced by quarry blasting. For this purpose, 95 blasting operations were precisely monitored in a granite quarry site in Malaysia and AOp values were recorded in each operation. Furthermore, the most influential parameters on AOp, including the maximum charge per delay and the distance between the blast-face and monitoring point, were measured and used to train the ICA-ANN model. Based on the generalized predictor equation and considering the measured data from the granite quarry site, a new empirical equation was developed to predict AOp. For comparison purposes, conventional ANN models were developed and compared with the ICA-ANN results. The results demonstrated that the proposed ICA-ANN model is able to predict blast-induced AOp more accurately than other presented techniques.

  4. Advance innovations of an intelligent sprayer for nursery and fruit tree crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Conventional spray application technology requires excessive amounts of pesticide use to achieve effective pest control in floral, nursery, and other specialty crop productions. This onerous challenge is now overcome by our newly developed automated variable-rate, air-assisted precision sprayer. Thi...

  5. Development of LIDAR-guided sprayer to synchronize spray outputs with canopy structures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Variable-rate application is an effective way for nursery and orchard growers to reduce pesticide use and potential contaminations to the environment. To realize this goal, an intelligent air-assisted sprayer implementing a high speed laser scanning sensor (LIDAR) was developed to vary spray output ...

  6. Periodic inspection on crop sprayers: results according to age of sprayers.

    PubMed

    Antuniassi, Ulisses R; Gandolfo, Marco A

    2005-01-01

    The objectives of the IPP Project--Periodic Inspection on Crop Sprayers--are to develop methods for sprayer certification, analyze quality on spray operation, propose an inspection system for crop sprayers in Brazil, improve environmental quality on spray operation, and reduce costs on chemical control for plant protection systems. Periodic inspections on crop sprayers are performed in several countries and are compulsory in most of them, and it is becoming an important tool for improvement and optimization of use of chemicals. The IPP Project in Brazil is funded by FAPESP--Fundação de Amparo à Pesquisa do Estado de São Paulo. The results so far showed that all the sprayers presented failures. However, most of them could be approved with minor services. As an example, 56.6% of the sprayers with more than 2 years of use presented leaks, 47% of them had damaged hoses and 80.5% presented bad tips (nozzles). These results indicate the need for better procedures of use and maintenance of sprayers, justifying the periodic inspection system.

  7. Power Sprayers, Power Dusters, and Aerial Equipment for Pesticide Application.

    ERIC Educational Resources Information Center

    Cole, Herbert, Jr.

    This agriculture extension service publication from Pennsylvania State University discusses agricultural pesticide application equipment. The three sections of the publication are Power Sprayers, Power Dusters, and Aerial Equipment. In the section discussing power sprayers, subtopics include hydraulic sprayers, component parts, multi-purpose farm…

  8. Quantification of emissions from knapsack sprayers: 'the weight method

    NASA Astrophysics Data System (ADS)

    Garcia-Santos, Glenda; Binder, Claudia R.

    2010-05-01

    Misuse of pesticides kill or seriously sicken thousands of people every year and poison the natural environment. Investigations of occupational and environmental risk have received considerable interest over the last decades. And yet, lack of staff and analytical equipments as well the costs of chemical analyses make difficult, if not impossible, the control of the pesticide contamination and residues in humans, air, water, and soils in developing countries. To assess emissions of pesticides (transport and deposition) during spray application and the risk for the human health and the environment, tracers can be useful tools. Uranine was used to quantify drift airborne and later deposition on the neighbouring field and clothes of the applicator after spraying with a knapsack sprayer in one of the biggest areas of potato production in Colombia. Keeping the same setup the amount of wet drift was measured by difference in the weight of high absorbent papers used to collect the tracer. Surprisingly this weight method (Weight-HAP) was able to explain 71% of the drift variance measured with the tracer. Therefore the weight method is presented as a suitable rapid low cost screening tool, complementary to toxicological tests, to assess air pollution, occupational and environmental exposure generated by the emissions from knapsack sprayers during pesticide application. This technique might be important in places were there is lack of analytical instruments.

  9. 500-kV HVDC air-blast circuit breaker. Final report

    SciTech Connect

    Bachman, B.; Ruoss, E.

    1986-08-01

    This report describes the first HVDC circuit breaker to be tested on a full-scale utility system. Modular in construction to ensure economic feasibility, this breaker has a standard ac air-blast breaker as its main component and interrupts current up to 2200-A dc.

  10. A geophysical shock and air blast simulator at the National Ignition Facility.

    PubMed

    Fournier, K B; Brown, C G; May, M J; Compton, S; Walton, O R; Shingleton, N; Kane, J O; Holtmeier, G; Loey, H; Mirkarimi, P B; Dunlop, W H; Guyton, R L; Huffman, E

    2014-09-01

    The energy partitioning energy coupling experiments at the National Ignition Facility (NIF) have been designed to measure simultaneously the coupling of energy from a laser-driven target into both ground shock and air blast overpressure to nearby media. The source target for the experiment is positioned at a known height above the ground-surface simulant and is heated by four beams from the NIF. The resulting target energy density and specific energy are equal to those of a low-yield nuclear device. The ground-shock stress waves and atmospheric overpressure waveforms that result in our test system are hydrodynamically scaled analogs of full-scale seismic and air blast phenomena. This report summarizes the development of the platform, the simulations, and calculations that underpin the physics measurements that are being made, and finally the data that were measured. Agreement between the data and simulation of the order of a factor of two to three is seen for air blast quantities such as peak overpressure. Historical underground test data for seismic phenomena measured sensor displacements; we measure the stresses generated in our ground-surrogate medium. We find factors-of-a-few agreement between our measured peak stresses and predictions with modern geophysical computer codes. PMID:25273784

  11. A geophysical shock and air blast simulator at the National Ignition Facility

    SciTech Connect

    Fournier, K. B.; Brown, C. G.; May, M. J.; Compton, S.; Walton, O. R.; Shingleton, N.; Kane, J. O.; Holtmeier, G.; Loey, H.; Mirkarimi, P. B.; Dunlop, W. H.; Guyton, R. L.; Huffman, E.

    2014-09-01

    The energy partitioning energy coupling experiments at the National Ignition Facility (NIF) have been designed to measure simultaneously the coupling of energy from a laser-driven target into both ground shock and air blast overpressure to nearby media. The source target for the experiment is positioned at a known height above the ground-surface simulant and is heated by four beams from the NIF. The resulting target energy density and specific energy are equal to those of a low-yield nuclear device. The ground-shock stress waves and atmospheric overpressure waveforms that result in our test system are hydrodynamically scaled analogs of full-scale seismic and air blast phenomena. This report summarizes the development of the platform, the simulations, and calculations that underpin the physics measurements that are being made, and finally the data that were measured. Agreement between the data and simulation of the order of a factor of two to three is seen for air blast quantities such as peak overpressure. Historical underground test data for seismic phenomena measured sensor displacements; we measure the stresses generated in our ground-surrogate medium. We find factors-of-a-few agreement between our measured peak stresses and predictions with modern geophysical computer codes.

  12. A geophysical shock and air blast simulator at the National Ignition Facility

    SciTech Connect

    Fournier, K. B.; Brown, C. G.; May, M. J.; Compton, S.; Walton, O. R.; Shingleton, N.; Kane, J. O.; Holtmeier, G.; Loey, H.; Mirkarimi, P. B.; Dunlop, W. H.; Guyton, R. L.; Huffman, E.

    2014-09-15

    The energy partitioning energy coupling experiments at the National Ignition Facility (NIF) have been designed to measure simultaneously the coupling of energy from a laser-driven target into both ground shock and air blast overpressure to nearby media. The source target for the experiment is positioned at a known height above the ground-surface simulant and is heated by four beams from the NIF. The resulting target energy density and specific energy are equal to those of a low-yield nuclear device. The ground-shock stress waves and atmospheric overpressure waveforms that result in our test system are hydrodynamically scaled analogs of full-scale seismic and air blast phenomena. This report summarizes the development of the platform, the simulations, and calculations that underpin the physics measurements that are being made, and finally the data that were measured. Agreement between the data and simulation of the order of a factor of two to three is seen for air blast quantities such as peak overpressure. Historical underground test data for seismic phenomena measured sensor displacements; we measure the stresses generated in our ground-surrogate medium. We find factors-of-a-few agreement between our measured peak stresses and predictions with modern geophysical computer codes.

  13. Air blasts generated by rockfall impacts: Analysis of the 1996 Happy Isles event in Yosemite National Park

    USGS Publications Warehouse

    Morrissey, M.M.; Savage, W.Z.; Wieczorek, G.F.

    1999-01-01

    The July 10, 1996, Happy Isles rockfall in Yosemite National Park, California, released 23,000 to 38,000 m3 of granite in four separate events. The impacts of the first two events which involved a 550-m free fall, generated seismic waves and atmospheric pressure waves (air blasts). We focus on the dynamic behavior of the second air blast that downed over 1000 trees, destroyed a bridge, demolished a snack bar, and caused one fatality and several injuries. Calculated velocities for the air blast from a two-phase, finite difference model are compared to velocities estimated from tree damage. From tornadic studies of tree damage, the air blast is estimated to have traveled <108-120 m/s within 50 m from the impact and decreased to <10-20 m/s within 500 m from the impact. The numerical model simulates the two-dimensional propagation of an air blast through a dusty atmosphere with initial conditions defined by the impact velocity and pressure. The impact velocity (105-107 m/s) is estimated from the Colorado Rockfall Simulation Program that simulates rockfall trajectories. The impact pressure (0.5 MPa) is constrained by the kinetic energy of the impact (1010-1012 J) estimated from the seismic energy generated by the impact. Results from the air blast simulations indicate that the second Happy Isles air blast (weak shock wave) traveled with an initial velocity above the local sound speed. The size and location of the first impact are thought to have injected <50 wt % dust into the atmosphere. This amount of dust lowered the local atmospheric sound speed to ???220 m/s. The discrepancy between calculated velocity data and field estimated velocity data (???220 m/s versus ???110 m/s) is attributed to energy dissipated by the downing of trees and additional entrainment of debris into the atmosphere not included in the calculations. Copyright 1999 by the American Geophysical Union.

  14. Changes in Ultrastructure and Sensory Characteristics on Electro-magnetic and Air Blast Freezing of Beef during Frozen Storage.

    PubMed

    Choi, Yun-Sang; Ku, Su-Kyung; Jeong, Ji-Yun; Jeon, Ki-Hong; Kim, Young-Boong

    2015-01-01

    The ultrastructure in the beef muscle of the electro-magnetic resonance and air blast freezing during the frozen storage, and the changes in the quality characteristics after thawing were evaluated. The size of ice crystal was small and evenly formed in the initial freezing period, and it showed that the size was increased as the storage period was elapsed (p<0.05). The beef stored by the electro-magnetic resonance freezing showed the size of ice crystal with a lower rate of increase than the air blast freezing during the frozen storage. The thawing loss of beef stored by the electro-magnetic resonance freezing was significantly lower than the air blast freezing during frozen storage (p<0.05), and it showed that the thawing loss of the round was higher than the loin. Water holding capacity decreased as the storage period became longer while the electro-magnetic resonance freezing was higher than the air blast on 8 month (p<0.05). As a result of sensory evaluation, the beef stored by the electro-magnetic resonance freezing did not show the difference until 4 months, and it showed higher acceptability in comparison with the beef stored by the air blast freezing. Thus, it is considered that the freezing method has an effect on the change in the ultrastructure and quality characteristics of the beef.

  15. Hydrodynamic Modeling of Air Blast Propagation from the Humble Redwood Chemical High Explosive Detonations Using GEODYN

    SciTech Connect

    Chipman, V D

    2011-09-20

    Two-dimensional axisymmetric hydrodynamic models were developed using GEODYN to simulate the propagation of air blasts resulting from a series of high explosive detonations conducted at Kirtland Air Force Base in August and September of 2007. Dubbed Humble Redwood I (HR-1), these near-surface chemical high explosive detonations consisted of seven shots of varying height or depth of burst. Each shot was simulated numerically using GEODYN. An adaptive mesh refinement scheme based on air pressure gradients was employed such that the mesh refinement tracked the advancing shock front where sharp discontinuities existed in the state variables, but allowed the mesh to sufficiently relax behind the shock front for runtime efficiency. Comparisons of overpressure, sound speed, and positive phase impulse from the GEODYN simulations were made to the recorded data taken from each HR-1 shot. Where the detonations occurred above ground or were shallowly buried (no deeper than 1 m), the GEODYN model was able to simulate the sound speeds, peak overpressures, and positive phase impulses to within approximately 1%, 23%, and 6%, respectively, of the actual recorded data, supporting the use of numerical simulation of the air blast as a forensic tool in determining the yield of an otherwise unknown explosion.

  16. Human response to house vibrations caused by sonic booms or air blasts.

    PubMed

    Schomer, P D

    1978-07-01

    Descriptions of the effects of sonic booms of air blasts by observers in buildings have included such statements as "noticeable vibrations" in addition to phrases such as "the house rattles," "the windows rattle," or "bric-à-brac rattles." Analysis of studies of human response to vibrations, vibration complaints in the Toronto area, special tests by Kryter at Edwards Air Force Base, and laboratory studies of human response to sonic booms show that perceived vibration is not normally a factor that contributes significantly to human response to airborne, large-amplitude impulse noise. Rather, human response is solely the result of the impulse noise itself and of audible noise due to induced radiation from vibrating surfaces. PMID:711997

  17. German Air Forces experiences with plastic media blasting and future requirements

    NASA Astrophysics Data System (ADS)

    Stoermer, Matthias

    1993-03-01

    German Air Force (GAF) has been researching a method of paint removal for a couple of years to replace the chemical method still in use. This is to improve corrosion prevention, environmental protection and health care. With the support of German aerospace company MBB and the University of the Armed Forces in Munich GAF selected Plastic Media Blasting (PMB) as the most suitable method. Having a stripping facility for the entire aircraft at MBB Manching already in existence, GAF decided that the next step forward to gain more experiences is to establish a smaller 'stripping cabin' at an air force base. This cabin is suitable for stripping removable parts and components of aircraft and equipment with the max. size of a half dismantled TORNADO wing. With these gained experiences GAF will be in position to formulate the specific requirements for an entire on-base aircraft stripping plant which will be suitable for F-4's, TORNADO's and EFA's, too.

  18. Weed Control Sprayers: Calibration and Maintenance. Special Circular 81.

    ERIC Educational Resources Information Center

    Myers, Arthur L.

    This manual covers aspects of calibration and maintenance of weed control sprayers including variables affecting application rate, the pre-calibration check, calculations, band spraying, nozzle tip selection, agitation, and cleaning. (BB)

  19. Estimation of Yield and Height-of-Burst for Near-Surface Explosions from Joint Inversion of Air-Blast and Seismic Data

    NASA Astrophysics Data System (ADS)

    Rodgers, A.; Xu, H.; Templeton, D. C.; Ramirez, A. L.; Chipman, V.; Ford, S. R.; Chambers, D. H.

    2011-12-01

    Near-surface explosions generate air-blast overpressure and seismic ground motions. It is well known that air-blast and seismic amplitudes depend on explosive yield and range. However for explosions near the ground surface the excitation of air-blast overpressure in the atmosphere and seismic motions depends strongly on the height-of-burst (HOB) for above ground or depth-of-burial (DOB, negative HOB) for buried explosions. We report an algorithm for estimating yield and HOB from near-surface explosions by joint inversion of air-blast overpressure and seismic ground motion amplitudes. The HUMBLE REDWOOD series of chemical explosions conducted at Kirtland AFB were explicitly designed to investigate the effect of HOB on air-blast and seismic motions. Analysis of these data indicates that scaled-range and HOB effects separate and provide calibration data for signal behavior with yield, range and HOB. Variation of air-blast measurements with scaled range for above ground explosions is reasonably well fit by reported models. Dependence with scaled HOB is determined with residuals from above ground air-blast models fit to a parameterized curve. Resampling of the data allows estimates of model errors for both scaled range and scaled HOB and is also used to propagate model errors in the inversion. Similar analysis is performed for the dependence of seismic amplitudes with scaled range and scaled HOB. The inversion of air-blast and seismic amplitudes for yield and HOB uses either a grid search or Markov Chain Monte Carlo (MCMC) approach. The algorithm runs very quickly in either case because the forward calculations are algebraic and very efficient for this two-dimensional model space. We show that inversion results obtained with only one data type (air-blast or seismic) are strongly non-unique and often have large bias. However, joint inversion of air-blast and seismic data breaks the trade-offs between yield and HOB and leads to more accurate estimates. We find that

  20. Analysis of Fuel Injection and Atomization of a Hybrid Air-Blast Atomizer.

    NASA Astrophysics Data System (ADS)

    Ma, Peter; Esclape, Lucas; Buschhagen, Timo; Naik, Sameer; Gore, Jay; Lucht, Robert; Ihme, Matthias

    2015-11-01

    Fuel injection and atomization are of direct importance to the design of injector systems in aviation gas turbine engines. Primary and secondary breakup processes have significant influence on the drop-size distribution, fuel deposition, and flame stabilization, thereby directly affecting fuel conversion, combustion stability, and emission formation. The lack of predictive modeling capabilities for the reliable characterization of primary and secondary breakup mechanisms is still one of the main issues in improving injector systems. In this study, an unstructured Volume-of-Fluid method was used in conjunction with a Lagrangian-spray framework to conduct high-fidelity simulations of the breakup and atomization processes in a realistic gas turbine hybrid air blast atomizer. Results for injection with JP-8 aviation fuel are presented and compared to available experimental data. Financial support through the FAA National Jet Fuel Combustion Program is gratefully acknowledged.

  1. Higher mortality risk of lungs carcinoma in vineyard sprayers.

    PubMed

    Santić, Zarko; Puvacić, Zlatko; Radović, Svjetlana; Puvacić, Sandra

    2005-05-01

    This study investigated mortality rate of lungs carcinoma in professional vineyard sprayers. Clinical investigation was performed in 187 professional vineyard sprayers who had been exposed to the inhalation of the particles of Bordeaux mixture for 24 years on average. Bordeaux Mixture is used for prevention against mildew attacking vineyards. The control group was composed of 187 inhabitants of the same area who did not have any contact with the mentioned substance. A cytological investigation of the sputum specimens obtained from 104 tested inhabitants was performed. The sputum specimens were stained with standard haematoxylin-eosin method and also with special method (rubeanic acid) to prove the incidence of copper granules in macrophages. The findings show a considerable statistical difference in the frequency of occurrence of lungs carcinoma between the group of vineyard sprayers smokers and the control group (X2=4.77,p<0.01). The risk of lungs carcinoma in the vineyard sprayers was three times higher compared to the risk of smokers in the control group, with a statistical probability of 95% in the scope from 1.16sprayers is significantly higher (p<0.01) compared to the risk in the control group.

  2. Model for small arms fire muzzle blast wave propagation in air

    NASA Astrophysics Data System (ADS)

    Aguilar, Juan R.; Desai, Sachi V.

    2011-11-01

    Accurate modeling of small firearms muzzle blast wave propagation in the far field is critical to predict sound pressure levels, impulse durations and rise times, as functions of propagation distance. Such a task being relevant to a number of military applications including the determination of human response to blast noise, gunfire detection and localization, and gun suppressor design. Herein, a time domain model to predict small arms fire muzzle blast wave propagation is introduced. The model implements a Friedlander wave with finite rise time which diverges spherically from the gun muzzle. Additionally, the effects in blast wave form of thermoviscous and molecular relaxational processes, which are associated with atmospheric absorption of sound were also incorporated in the model. Atmospheric absorption of blast waves is implemented using a time domain recursive formula obtained from numerical integration of corresponding differential equations using a Crank-Nicholson finite difference scheme. Theoretical predictions from our model were compared to previously recorded real world data of muzzle blast wave signatures obtained by shooting a set different sniper weapons of varying calibers. Recordings containing gunfire acoustical signatures were taken at distances between 100 and 600 meters from the gun muzzle. Results shows that predicted blast wave slope and exponential decay agrees well with measured data. Analysis also reveals the persistency of an oscillatory phenomenon after blast overpressure in the recorded wave forms.

  3. Evaluation of overpressure prediction models for air blast above the triple point.

    PubMed

    Ehrhardt, L; Boutillier, J; Magnan, P; Deck, C; De Mezzo, S; Willinger, R; Cheinet, S

    2016-07-01

    The increase of blast exposures leads to the need for better assessment of the blast threat. Empirical models describing the blast propagation in ideal conditions as free-field or surface detonations are commonly employed, but in some configurations the ground-reflected shock should be treated explicitly. Empirical models permit the prediction of the blast characteristics with the ground-reflected shock. The present study uses some original experimental data to evaluate the accuracy of the predicted overpressure with time regarding the reflected shock characteristics. Three methods are tested. The first method, called method of images (MOI) and linearly adding a virtual ground-symmetrical source blast to the free-field blast, is quick but lacks accuracy regarding the reflected shock characteristics. The second method, based on the LOAD_BLAST_ENHANCED function of the commercial LS-DYNA framework, better captures the reflected shock compared to the MOI, but the overall differences with experimental data are of the same order of magnitude as for the MOI. An original fit is introduced, based on standard physical parameters. The accuracy of this fit on the reflected shock characteristics, and the better match with the overall overpressure time series, shows its potential as a new empirical blast predicting tool.

  4. Verification of a variable rate sprayer for nursery liner applications

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An experimental variable-rate sprayer designed for liner applications was tested by comparing its spray deposit and coverage, and droplet density inside canopies of six nursery liner varieties with constant-rate applications. Spray samplers, including water sensitive papers (WSP) and nylon screens, ...

  5. Gas and drop behavior in reacting and non-reacting air-blast atomizer sprays

    NASA Technical Reports Server (NTRS)

    Mcdonell, Vincent G.; Samuelsen, Scott

    1991-01-01

    A detailed study of the two-phase flow produced by a gas-turbine air-blast atomizer is performed with the goal of identifying the interaction between the two phases for both nonreacting and reacting conditions. A two-component phase Doppler interferometry is utilized to characterize three flowfields produced by the atomizer: (1) the single-phase flow, (2) the two-phase nonreacting spray, and (3) the two-phase reacting spray. Measurements of the mean and fluctuating axial and azimuthal velocities for each phase are obtained. In addition, the droplet size distribution, volume flux, and concentration are measured. The results reveal the strong influence of the dispersed phase on the gas, and the influence of reaction on both the gas and the droplet field. The presence of the spray significantly alters the inlet condition of the atomizer. With this alteration quantified, it is possible to deduce that the inertia associated with the dispersed phase damps the fluctuating velocities of the gas. Reaction reduces the volume flux of the droplets, broadens the local volume distribution of the droplets in the region of the reaction zone, increases the axial velocities and radial spread of the gas, and increases the anisotropy in the region of the reaction zone.

  6. An experimental investigation on the spray flow exhausted from a co-swirling air-blast nozzle

    NASA Astrophysics Data System (ADS)

    Dvorak, Daniel Dean

    The velocity field for a spray produced by an air-blast atomizer is measured using Particle Image Velocimetry (PIV). These measurements are conducted at a variety of input liquid and air mass flow rates producing many different air to liquid mass flow ratios (ALR). The experiment is repeated with two different liquids, water and a hydrocarbon based fuel substitute. It is found that the velocity field depends heavily on the type of fluid used as opposed to the ALR. The experiments are repeated using a Stereoscopic Particle Image Velocimetry (SPIV) measurement technique. These results are compared to the 2D PIV results, and the differences are discussed. Finally, the 2D PIV and SPIV results are compared to existing Laser Doppler Velocimetry (LDV) results. It is seen that the results from the two different techniques are not well correlated.

  7. Rock blasting environmental impacts

    SciTech Connect

    Agreda, C.

    1995-12-31

    The rock blasting environmental impacts such as: flyrock, ground vibrations, air-blast, and/or noise, dust and fumes are identified and mentioned. Some comments on the correction factors that might be taken into consideration to calculate the initial velocity and the maximum projection of the rock fragments are mentioned as well. The blast fumes causes, its alleviation and protective measures are identified, described and discussed. To mitigate, minimize and/or avoid blast fumes, the AN/FO, Al/AN/FO and S/AN/FO dry blasting agents optimum equations are developed, discussed and recommended.

  8. 29 CFR 1926.913 - Blasting in excavation work under compressed air.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... rock face is approaching mixed face, and when tunnel excavation is in mixed face, blasting shall be performed with light charges and with light burden on each hole. Advance drilling shall be performed as tunnel excavation in rock face approaches mixed face, to determine the general nature and extent of...

  9. Influence of ambient air pressure on the energy conversion of laser-breakdown induced blast waves

    NASA Astrophysics Data System (ADS)

    Wang, Bin; Komurasaki, Kimiya; Arakawa, Yoshihiro

    2013-09-01

    Influence of ambient pressure on energy conversion efficiency from a Nd : glass laser pulse (λ = 1.053 µm) to a laser-induced blast wave was investigated at reduced pressure. Temporal incident and transmission power histories were measured using sets of energy meters and photodetectors. A half-shadowgraph half-self-emission method was applied to visualize laser absorption waves. Results show that the blast energy conversion efficiency ηbw decreased monotonically with the decrease in ambient pressure. The decrease was small, from 40% to 38%, for the pressure change from 101 kPa to 50 kPa, but the decrease was considerable, to 24%, when the pressure was reduced to 30 kPa. Compared with a TEA-CO2-laser-induced blast wave (λ = 10.6 µm), higher fraction absorption in the laser supported detonation regime ηLSD of 90% was observed, which is influenced slightly by the reduction of ambient pressure. The conversion fraction ηbw/ηLSD≈90% was achieved at pressure >50 kPa, which is significantly higher than that in a CO2 laser case.

  10. Blast furnace stove control

    SciTech Connect

    Muske, K.R.; Hansen, G.A.; Howse, J.W.; Cagliostro, D.J.; Chaubal, P.C.

    1998-12-31

    This paper outlines the process model and model-based control techniques implemented on the hot blast stoves for the No. 7 Blast Furnace at the Inland Steel facility in East Chicago, Indiana. A detailed heat transfer model of the stoves is developed. It is then used as part of a predictive control scheme to determine the minimum amount of fuel necessary to achieve the blast air requirements. The controller also considers maximum and minimum temperature constraints within the stove.

  11. Smart sprayer project: sensor-based selective herbicide application system

    NASA Astrophysics Data System (ADS)

    Tian, Lei F.; Steward, Brian L.; Tang, Lie

    2000-12-01

    The smart sprayer, a local-vision-sensor-based precision chemical application system, was developed and tested. The long-term objectives of this project were to develop new technologies to estimate weed density and size in real-time, to realize site-specific weed control, and to effectively reduce the amount of herbicide applied to major crop fields. This research integrated a real-time machine vision sensing system and individual nozzle controlling device with a commercial map-driven-ready herbicide sprayer to create an intelligent sensing and spraying system. The machine vision system was specially designed to work under outdoor variable lighting conditions. Multiple vision sensors were used to cover the target area. Instead of trying to identify each individual plant in the field, weed infestation conditions in each control zone (management zone) were detected. To increase the delivery accuracy, each individual spray nozzle was controlled separately. The integrated system was tested to evaluate the effectiveness and performance under varying commercial field conditions. Using the on-board differential GPS, geo-referenced chemical input maps (equivalent to weed maps) were also recorded in real-time. The maps generated with this system have been compared with other sensing and referencing systems.

  12. Numerical simulation of the fluid-structure interaction between air blast waves and soil structure

    NASA Astrophysics Data System (ADS)

    Umar, S.; Risby, M. S.; Albert, A. Luthfi; Norazman, M.; Ariffin, I.; Alias, Y. Muhamad

    2014-03-01

    Normally, an explosion threat on free field especially from high explosives is very dangerous due to the ground shocks generated that have high impulsive load. Nowadays, explosion threats do not only occur in the battlefield, but also in industries and urban areas. In industries such as oil and gas, explosion threats may occur on logistic transportation, maintenance, production, and distribution pipeline that are located underground to supply crude oil. Therefore, the appropriate blast resistances are a priority requirement that can be obtained through an assessment on the structural response, material strength and impact pattern of material due to ground shock. A highly impulsive load from ground shocks is a dynamic load due to its loading time which is faster than ground response time. Of late, almost all blast studies consider and analyze the ground shock in the fluid-structure interaction (FSI) because of its influence on the propagation and interaction of ground shock. Furthermore, analysis in the FSI integrates action of ground shock and reaction of ground on calculations of velocity, pressure and force. Therefore, this integration of the FSI has the capability to deliver the ground shock analysis on simulation to be closer to experimental investigation results. In this study, the FSI was implemented on AUTODYN computer code by using Euler-Godunov and the arbitrary Lagrangian-Eulerian (ALE). Euler-Godunov has the capability to deliver a structural computation on a 3D analysis, while ALE delivers an arbitrary calculation that is appropriate for a FSI analysis. In addition, ALE scheme delivers fine approach on little deformation analysis with an arbitrary motion, while the Euler-Godunov scheme delivers fine approach on a large deformation analysis. An integrated scheme based on Euler-Godunov and the arbitrary Lagrangian-Eulerian allows us to analyze the blast propagation waves and structural interaction simultaneously.

  13. Robotic Water Blast Cleaner

    NASA Technical Reports Server (NTRS)

    Sharpe, M. H.; Roberts, M. L.; Hill, W. E.; Jackson, C. H.

    1983-01-01

    Water blasting system under development removes hard, dense, extraneous material from surfaces. High pressure pump forces water at supersonic speed through nozzle manipulated by robot. Impact of water blasts away unwanted material from workpiece rotated on air bearing turntable. Designed for removing thermal-protection material, system is adaptable to such industrial processes as cleaning iron or steel castings.

  14. The weight method: a new screening method for estimating pesticide deposition from knapsack sprayers in developing countries.

    PubMed

    García-Santos, Glenda; Scheiben, Dominik; Binder, Claudia R

    2011-03-01

    Investigations of occupational and environmental risk caused by the use of agrochemicals have received considerable interest over the last decades. And yet, in developing countries, the lack of staff and analytical equipment as well the costs of chemical analyses make it difficult, if not impossible, to monitor pesticide contamination and residues in humans, air, water, and soils. A new and simple method is presented here for estimation of pesticide deposition in humans and soil after application. The estimate is derived on the basis of water mass balance measured in a given number of high absorbent papers under low evaporative conditions and unsaturated atmosphere. The method is presented as a suitable, rapid, low cost screening tool, complementary to toxicological tests, to assess occupational and environmental exposure caused by knapsack sprayers, where there is a lack of analytical instruments. This new method, called the "weight method", was tested to obtain drift deposition on the neighbouring field and the clothes of the applicator after spraying water with a knapsack sprayer in one of the largest areas of potato production in Colombia. The results were confirmed by experimental data using a tracer and the same set up used for the weight method. The weight method was able to explain 86% of the airborne drift and deposition variance.

  15. METAL SPRAYER FOR USE IN VACUUM OR INERT ATMOSPHERE

    DOEpatents

    Monroe, R.E.

    1958-10-14

    A metal sprayer is described for use in a vacuum or inert atmosphere with a straight line wire feed and variable electrode contact angle. This apparatus comprises two wires which are fed through straight tubes of two mechanisms positioned on opposite sides of a central tube to which an inert gas is fed. The two mechanisms and the wires being fed constitute electrodes to which electrical current is supplied so that the wires are melted by the electric are formed at their contacting region and sprayed by the gas supplied by the central tube. This apparatus is designed specifically to apply a zirconium coating to uranium in an inert atmosphere and without the use of an oxidizing flame.

  16. Assessment of Serum Cholinesterase in Rural Punjabi Sprayers Exposed to a Mixture of Pesticides

    PubMed Central

    Dhalla, Amar Santosh; Sharma, Suman

    2013-01-01

    Serum cholinesterase (SChE) activity is considered as a biomarker and is also taken as an exposure index to assess the low level, chronic residue exposures among sprayers. Thus, cholinesterase activity was studied in the professional rural Punjabi sprayers of Bathinda district in Punjab. This study was made to estimate the irregularities in the level of cholinesterase according to multiple pesticides used by sprayers, exposure periods, age, and body mass index (BMI) of the sprayers. The data generated was statistically analyzed by applying Student's ‘t’ test and one-way analysis of variance. A positive correlation was found between SChE activity and years of exposure and a significant reduction in SChE activity was observed in younger population. Again, a positive correlation was seen between BMI and SChE inhibition. PMID:24082509

  17. Deposition and characterization of alumina-titania coating by multi-chamber gas-dynamic sprayer

    NASA Astrophysics Data System (ADS)

    Kovaleva, M.; Prozorova, M.; Arseenko, M.; Tyurin, Yu.; Kolisnichenko, O.; Vasilik, N.; Sirota, V.; Pavlenko, I.

    In this paper, alumina-titania coatings have been formed on aluminium substrate by multi-chamber detonation sprayer. The coatings were investigated using SEM, EDS, XRD and Vickers microhardness tester. The results show that the alumina-titania coatings consist of both fully melted regions and partially melted regions, and the fully melted region has a lamellar-like structure. The multi-chamber detonation sprayer produced the dense layers of coating with a high hardness.

  18. Investigation of the Impact of Desorption Electrospray Ionization Sprayer Geometry on Its Performance in Imaging of Biological Tissue.

    PubMed

    Tillner, Jocelyn; McKenzie, James S; Jones, Emrys A; Speller, Abigail V M; Walsh, James L; Veselkov, Kirill A; Bunch, Josephine; Takats, Zoltan; Gilmore, Ian S

    2016-05-01

    In this study, the impact of sprayer design and geometry on performance in desorption electrospray ionization mass spectrometry (DESI-MS) is assessed, as the sprayer is thought to be a major source of variability. Absolute intensity repeatability, spectral composition, and classification accuracy for biological tissues are considered. Marked differences in tissue analysis performance are seen between the commercially available and a lab-built sprayer. These are thought to be associated with the geometry of the solvent capillary and the resulting shape of the primary electrospray. Experiments with a sprayer with a fixed solvent capillary position show that capillary orientation has a crucial impact on tissue complex lipid signal and can lead to an almost complete loss of signal. Absolute intensity repeatability is compared for five lab-built sprayers using pork liver sections. Repeatability ranges from 1 to 224% for individual sprayers and peaks of different spectral abundance. Between sprayers, repeatability is 16%, 9%, 23%, and 34% for high, medium, low, and very low abundance peaks, respectively. To assess the impact of sprayer variability on tissue classification using multivariate statistical tools, nine human colorectal adenocarcinoma sections are analyzed with three lab-built sprayers, and classification accuracy for adenocarcinoma versus the surrounding stroma is assessed. It ranges from 80.7 to 94.5% between the three sprayers and is 86.5% overall. The presented results confirm that the sprayer setup needs to be closely controlled to obtain reliable data, and a new sprayer setup with a fixed solvent capillary geometry should be developed.

  19. Investigation of the Impact of Desorption Electrospray Ionization Sprayer Geometry on Its Performance in Imaging of Biological Tissue.

    PubMed

    Tillner, Jocelyn; McKenzie, James S; Jones, Emrys A; Speller, Abigail V M; Walsh, James L; Veselkov, Kirill A; Bunch, Josephine; Takats, Zoltan; Gilmore, Ian S

    2016-05-01

    In this study, the impact of sprayer design and geometry on performance in desorption electrospray ionization mass spectrometry (DESI-MS) is assessed, as the sprayer is thought to be a major source of variability. Absolute intensity repeatability, spectral composition, and classification accuracy for biological tissues are considered. Marked differences in tissue analysis performance are seen between the commercially available and a lab-built sprayer. These are thought to be associated with the geometry of the solvent capillary and the resulting shape of the primary electrospray. Experiments with a sprayer with a fixed solvent capillary position show that capillary orientation has a crucial impact on tissue complex lipid signal and can lead to an almost complete loss of signal. Absolute intensity repeatability is compared for five lab-built sprayers using pork liver sections. Repeatability ranges from 1 to 224% for individual sprayers and peaks of different spectral abundance. Between sprayers, repeatability is 16%, 9%, 23%, and 34% for high, medium, low, and very low abundance peaks, respectively. To assess the impact of sprayer variability on tissue classification using multivariate statistical tools, nine human colorectal adenocarcinoma sections are analyzed with three lab-built sprayers, and classification accuracy for adenocarcinoma versus the surrounding stroma is assessed. It ranges from 80.7 to 94.5% between the three sprayers and is 86.5% overall. The presented results confirm that the sprayer setup needs to be closely controlled to obtain reliable data, and a new sprayer setup with a fixed solvent capillary geometry should be developed. PMID:27014929

  20. 29 CFR 1926.913 - Blasting in excavation work under compressed air.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... of explosives and detonators. (e) All metal pipes, rails, air locks, and steel tunnel lining shall be... performed with light charges and with light burden on each hole. Advance drilling shall be performed...

  1. 29 CFR 1926.913 - Blasting in excavation work under compressed air.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... of explosives and detonators. (e) All metal pipes, rails, air locks, and steel tunnel lining shall be... performed with light charges and with light burden on each hole. Advance drilling shall be performed...

  2. Effect of aviation fuel type and fuel injection conditions on the spray characteristics of pressure swirl and hybrid air blast fuel injectors

    NASA Astrophysics Data System (ADS)

    Feddema, Rick

    Feddema, Rick T. M.S.M.E., Purdue University, December 2013. Effect of Aviation Fuel Type and Fuel Injection Conditions on the Spray Characteristics of Pressure Swirl and Hybrid Air Blast Fuel Injectors. Major Professor: Dr. Paul E. Sojka, School of Mechanical Engineering Spray performance of pressure swirl and hybrid air blast fuel injectors are central to combustion stability, combustor heat management, and pollutant formation in aviation gas turbine engines. Next generation aviation gas turbine engines will optimize spray atomization characteristics of the fuel injector in order to achieve engine efficiency and emissions requirements. Fuel injector spray atomization performance is affected by the type of fuel injector, fuel liquid properties, fuel injection pressure, fuel injection temperature, and ambient pressure. Performance of pressure swirl atomizer and hybrid air blast nozzle type fuel injectors are compared in this study. Aviation jet fuels, JP-8, Jet A, JP-5, and JP-10 and their effect on fuel injector performance is investigated. Fuel injector set conditions involving fuel injector pressure, fuel temperature and ambient pressure are varied in order to compare each fuel type. One objective of this thesis is to contribute spray patternation measurements to the body of existing drop size data in the literature. Fuel droplet size tends to increase with decreasing fuel injection pressure, decreasing fuel injection temperature and increasing ambient injection pressure. The differences between fuel types at particular set conditions occur due to differences in liquid properties between fuels. Liquid viscosity and surface tension are identified to be fuel-specific properties that affect the drop size of the fuel. An open aspect of current research that this paper addresses is how much the type of aviation jet fuel affects spray atomization characteristics. Conventional aviation fuel specifications are becoming more important with new interest in alternative

  3. 29 CFR 1926.913 - Blasting in excavation work under compressed air.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... use in wet holes shall be water-resistant and shall be Fume Class 1. (g) When tunnel excavation in... explosives shall not be stored or kept in tunnels, shafts, or caissons. Detonators and explosives for each... of explosives and detonators. (e) All metal pipes, rails, air locks, and steel tunnel lining shall...

  4. 29 CFR 1926.913 - Blasting in excavation work under compressed air.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... use in wet holes shall be water-resistant and shall be Fume Class 1. (g) When tunnel excavation in... explosives shall not be stored or kept in tunnels, shafts, or caissons. Detonators and explosives for each... of explosives and detonators. (e) All metal pipes, rails, air locks, and steel tunnel lining shall...

  5. Simulation of Blast Waves with Headwind

    NASA Technical Reports Server (NTRS)

    Olsen, Michael E.; Lawrence, Scott W.; Klopfer, Goetz H.; Mathias, Dovan; Onufer, Jeff T.

    2005-01-01

    The blast wave resulting from an explosion was simulated to provide guidance for models estimating risks for human spacecraft flight. Simulations included effects of headwind on blast propagation, Blasts were modelled as an initial value problem with a uniform high energy sphere expanding into an ambient field. Both still air and cases with headwind were calculated.

  6. A novel closed-body model of spinal cord injury caused by high-pressure air blasts produces extensive axonal injury and motor impairments.

    PubMed

    del Mar, Nobel; von Buttlar, Xinyu; Yu, Angela S; Guley, Natalie H; Reiner, Anton; Honig, Marcia G

    2015-09-01

    Diffuse axonal injury is thought to be the basis of the functional impairments stemming from mild traumatic brain injury. To examine how axons are damaged by traumatic events, such as motor vehicle accidents, falls, sports activities, or explosive blasts, we have taken advantage of the spinal cord with its extensive white matter tracts. We developed a closed-body model of spinal cord injury in mice whereby high-pressure air blasts targeted to lower thoracic vertebral levels produce tensile, compressive, and shear forces within the parenchyma of the spinal cord and thereby cause extensive axonal injury. Markers of cytoskeletal integrity showed that spinal cord axons exhibited three distinct pathologies: microtubule breakage, neurofilament compaction, and calpain-mediated spectrin breakdown. The dorsally situated axons of the corticospinal tract primarily exhibited microtubule breakage, whereas all three pathologies were common in the lateral and ventral white matter. Individual axons typically demonstrated only one of the three pathologies during the first 24h after blast injury, suggesting that the different perturbations are initiated independently of one another. For the first few days after blast, neurofilament compaction was frequently accompanied by autophagy, and subsequent to that, by the fragmentation of degenerating axons. TuJ1 immunolabeling and mice with YFP-reporter labeling each revealed more extensive microtubule breakage than did βAPP immunolabeling, raising doubts about the sensitivity of this standard approach for assessing axonal injury. Although motor deficits were mild and largely transient, some aspects of motor function gradually worsened over several weeks, suggesting that a low level of axonal degeneration continued past the initial wave. Our model can help provide further insight into how to intervene in the processes by which initial axonal damage culminates in axonal degeneration, to improve outcomes after traumatic injury. Importantly

  7. A novel closed-body model of spinal cord injury caused by high-pressure air blasts produces extensive axonal injury and motor impairments

    PubMed Central

    del Mar, Nobel; von Buttlar, Xinyu; Yu, Angela S.; Guley, Natalie H.; Reiner, Anton; Honig, Marcia G.

    2015-01-01

    Diffuse axonal injury is thought to be the basis of the functional impairments stemming from mild traumatic brain injury. To examine how axons are damaged by traumatic events, such as motor vehicle accidents, falls, sports activities, or explosive blasts, we have taken advantage of the spinal cord with its extensive white matter tracts. We developed a closed-body model of spinal cord injury in mice whereby high-pressure air blasts targeted to lower thoracic vertebral levels produce tensile, compressive, and shear forces within the parenchyma of the spinal cord and thereby cause extensive axonal injury. Markers of cytoskeletal integrity showed that spinal cord axons exhibited three distinct pathologies: microtubule breakage, neurofilament compaction, and calpain-mediated spectrin breakdown. The dorsally situated axons of the corticospinal tract primarily exhibited microtubule breakage, whereas all three pathologies were common in the lateral and ventral white matter. Individual axons typically demonstrated only one of the three pathologies during the first 24 h after blast injury, suggesting that the different perturbations are initiated independently of one another. For the first few days after blast, neurofilament compaction was frequently accompanied by autophagy, and subsequent to that, by the fragmentation of degenerating axons. TuJ1 immunolabeling and mice with YFP-reporter labeling each revealed more extensive microtubule breakage than did βAPP immunolabeling, raising doubts about the sensitivity of this standard approach for assessing axonal injury. Although motor deficits were mild and largely transient, some aspects of motor function gradually worsened over several weeks, suggesting that a low level of axonal degeneration continued past the initial wave. Our model can help provide further insight into how to intervene in the processes by which initial axonal damage culminates in axonal degeneration, to improve outcomes after traumatic injury. Importantly

  8. Evaluation of Three Commercial Backpack Sprayers with Aqualuer® 20-20 Against Caged Adult Aedes Aegypti.

    PubMed

    Conover, Derrick; Fulcher, Ali; Smith, Michael L; Farooq, Muhammad; Gaines, Marcia K; Xue, Rui-De

    2015-06-01

    Three commercially available backpack sprayers were evaluated with Aqualuer® 20-20 (20.6% permethrin, active ingredient; 20.6% piperonyl butoxide, technical) against caged adult Aedes aegypti in semifield trials in northeastern Florida. Two battery-powered sprayers, Birchmeier and Hudson, were compared with the standard hand-pump SOLO 425 sprayer, which is currently used in pest management operations. Physical characteristics, droplet analysis, and overall ease of use were documented. Multiple dilutions of the insecticide were also evaluated. The results indicated that the Birchmeier sprayer was the preferable machine in terms of its physical characteristics and operator use. There was no significant difference in percent mortality of the test mosquitoes between the sprayers. Multiple dilutions ranging from 1:9 to 1:1050 of the insecticide resulted in greater than 80% mean mortality. PMID:26181698

  9. Evaluation of Three Commercial Backpack Sprayers with Aqualuer® 20-20 Against Caged Adult Aedes Aegypti.

    PubMed

    Conover, Derrick; Fulcher, Ali; Smith, Michael L; Farooq, Muhammad; Gaines, Marcia K; Xue, Rui-De

    2015-06-01

    Three commercially available backpack sprayers were evaluated with Aqualuer® 20-20 (20.6% permethrin, active ingredient; 20.6% piperonyl butoxide, technical) against caged adult Aedes aegypti in semifield trials in northeastern Florida. Two battery-powered sprayers, Birchmeier and Hudson, were compared with the standard hand-pump SOLO 425 sprayer, which is currently used in pest management operations. Physical characteristics, droplet analysis, and overall ease of use were documented. Multiple dilutions of the insecticide were also evaluated. The results indicated that the Birchmeier sprayer was the preferable machine in terms of its physical characteristics and operator use. There was no significant difference in percent mortality of the test mosquitoes between the sprayers. Multiple dilutions ranging from 1:9 to 1:1050 of the insecticide resulted in greater than 80% mean mortality.

  10. Quantitative analysis of the effects of ultrasound from an odor sprayer on moth flight behavior.

    PubMed

    Skals, Niels; Plepys, Dainius; El-Sayed, Ashraf M; Löfstedt, Christer; Surlykke, Annemarie

    2003-01-01

    A piezoelectric sprayer was recently developed for precision release of odor stimuli in olfactory research. The device replaces conventional dispensers used to release semiochemicals in studies of moth flight toward sources. However, the device generates high-frequency sounds in the range that some moths can hear. Ultrasound from the standard set-up sprayer had a considerable impact on flight behavior of the silver Y moth, Autographa gamma, tested in a flight tunnel. It was affected at all behavioral stages when the dispenser was driven at 120 kHz. Only 5% of the moths reached the source when exposed to 120-kHz sound from the dispenser compared to 65% in the control group without sound. The proportion taking flight was also reduced. Hearing threshold curves obtained electrophysiologically revealed that moths were sensitive to the frequency range at which the sprayer was operated and that sound intensity from the sprayer was up to 40 dB above the moths' electrophysiological hearing threshold. The audiogram for A. gamma was similar to audiograms obtained for other noctuids. Hearing sensitivity was highest at around 15 kHz, where the threshold was 35 dB SPL (sound pressure level). The threshold increased with frequency up to 94 dB SPL at 160 kHz. We improved the sprayer to operate at 300 kHz, which is beyond the hearing ability of most insects with ears. At this high frequency, the moths' sensitivity to ulrasound is reduced considerably, and we did not observe any effect on flight behavior compared to a control group without sound. Accordingly, this new piezoelectric sprayer can be used with ultrasound-sensitive insects and insensitive insects alike. PMID:12647854

  11. Performance evaluation of a newly developed variable rate sprayer for nursery liner applications

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An experimental variable-rate sprayer designed for liner applications was tested by comparing its spray deposit, coverage, and droplet density inside canopies of six nursery liner varieties with constant-rate applications. Spray samplers, including water sensitive papers (WSP) and nylon screens, wer...

  12. Evaluation of spray droplet spectrum of sprayers used for vector control

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Droplet spectra data were collected from spray equipment intended for use in vector control by the US Department of Defense pest management programs to determine if they produce droplets in the ultra-low volume (ULV) spectrum. Droplets generated by 26 sprayers utilizing water + non-ionic surfactant...

  13. Microstructure and Mechanical Properties of Alumina Powder Coatings by a New Multi-Chamber Detonation Sprayer

    NASA Astrophysics Data System (ADS)

    Prozorova, M. S.; Kovaleva, M. G.; Arseenko, M. Yu.; Yapryntsev, M. N.; Tyurin, Yu. N.; Kolisnichenko, O. V.; Vasilik, N. Ya.; Sirota, V. V.; Pavlenko, I. A.; Mamunin, K. N.

    2016-11-01

    The dense ceramic coatings based on alumina with hardness of 1100±25 HV0.3 and porosity of less than 1% have been prepared by multi-chamber detonation sprayer (MCDS) with a barrel length of 500mm. The intermetallic compound of type FeAl was revealed in the area of the coating that adjoins the substrate.

  14. Evaluation of a laser scanning sensor for variable-rate tree sprayer development

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Accurate canopy measurement capabilities are prerequisites to automate variable-rate sprayers. A 270° radial range laser scanning sensor was tested for its scanning accuracy to detect tree canopy profiles. Signals from the laser sensor and a ground speed sensor were processed with an embedded comput...

  15. Delay times of a LiDAR-guided precision sprayer control system

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Accurate flow control systems in triggering sprays against detected targets are needed for precision variable-rate sprayer development. System delay times due to the laser-sensor data buffer, software operation, and hydraulic-mechanical component response were determined for a control system used fo...

  16. Impact of electrostatic and conventional sprayers characteristics on dispersion of barrier spray

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A study was conducted to analyze the performance of three electrostatic (Electrolon BP-2.5TM, Spectrum Electrostatic 4010, and Spectrum Electrostatic head on a Stihl 420) and two conventional (Buffalo Turbine CSM2 and Stihl 420) sprayers for barrier sprays to suppress an adult mosquito population in...

  17. Blast Injuries

    MedlinePlus

    ... Service Members & Veterans Family & Caregivers Medical Providers Blast Injuries U.S. Army photo by Sgt. Gustavo Olgiati How ... tertiary injury Does a blast cause different brain injuries than blunt trauma? There currently is no evidence ...

  18. Blast wave parameters at diminished ambient pressure

    NASA Astrophysics Data System (ADS)

    Silnikov, M. V.; Chernyshov, M. V.; Mikhaylin, A. I.

    2015-04-01

    Relation between blast wave parameters resulted from a condensed high explosive (HE) charge detonation and a surrounding gas (air) pressure has been studied. Blast wave pressure and impulse differences at compression and rarefaction phases, which traditionally determine damage explosive effect, has been analyzed. An initial pressure effect on a post-explosion quasi-static component of the blast load has been investigated. The analysis is based on empirical relations between blast parameters and non-dimensional similarity criteria. The results can be directly applied to flying vehicle (aircraft or spacecraft) blast safety analysis.

  19. Development of a machine vision system for a real-time precision sprayer

    NASA Astrophysics Data System (ADS)

    Bossu, Jérémie; Gée, Christelle; Truchetet, Frédéric

    2007-01-01

    In the context of precision agriculture, we have developed a machine vision system for a real time precision sprayer. From a monochrome CCD camera located in front of the tractor, the discrimination between crop and weeds is obtained with an image processing based on spatial information using a Gabor filter. This method allows to detect the periodic signals from the non periodic one and it enables to enhance the crop rows whereas weeds have patchy distribution. Thus, weed patches were clearly identified by a blob-coloring method. Finally, we use a pinhole model to transform the weed patch coordinates image in world coordinates in order to activate the right electro-pneumatic valve of the sprayer at the right moment.

  20. Air

    MedlinePlus

    ... do to protect yourself from dirty air . Indoor air pollution and outdoor air pollution Air can be polluted indoors and it can ... this chart to see what things cause indoor air pollution and what things cause outdoor air pollution! Indoor ...

  1. Method of blast heating

    SciTech Connect

    Voges, B.

    1984-06-05

    A method of and a device for blast heating is described, employing separate indirect heat exchangers for combustion air and fuel gas fed to a regenerator and flue gases discharged from the regenerator. The indirect heat exchangers share heat-transfer liquid recirculating in a circuit in which an auxiliary heat exchanger is connected. In the latter exchanger, the temperature of transfer liquid is increased by combustion of partial streams of combustion air and fuel gas branched off downstream of the indirect heat exchangers. The temperature is increased to such a value which preheats the fuel gas to a temperature at which a substitution of fuel gas of a low calorific value, such as waste gas from a blast furnace, for fuel gas of high calorific value, is made possible.

  2. Calculating the parameters of self-oscillations in the vertical combustion chamber of the blast-furnace air heater during unstable combustion

    NASA Astrophysics Data System (ADS)

    Basok, B. I.; Gotsulenko, V. V.

    2015-01-01

    A procedure for simplified calculation of the parameters of self-oscillations excited during unstable (vibrating) combustion in the vertical combustion chambers of blast-furnace air heaters is developed. The proposed procedure is based on an independent nonlinear dynamic system similar to the equations from the theory of a blade supercharger stalling and surging mode. The head characteristic considered in the blade supercharger stalling and surging theory determines the part of the supercharger drive rotation energy that is converted into the head developed by the supercharger. In the considered system, the supercharger head characteristic is replaced by the combustion chamber head characteristic. Being a function of flow rate, this characteristic describes the part of heat supplied to flow that is converted to the flow head. Unlike the supercharger head characteristic, which is determined by experiment, the combustion chamber head characteristic is determined by calculation, due to which it becomes much easier to calculate the parameters of self-oscillations according to the proposed procedure. In particular, an analysis of the periodic solutions of the obtained dynamic system made it possible to determine the pattern in which the amplitude of considered self-oscillations depends on the surge impedance of the vertical combustion chamber.

  3. Mental workload associated with operating an agricultural sprayer: an empirical approach.

    PubMed

    Dey, A K; Mann, D D

    2011-04-01

    Agricultural spraying involves two major tasks: guiding a sprayer in response to a GPS navigation device, and simultaneous monitoring of rear-attached booms under various illumination and terrain difficulty levels. The aim of the present study was to investigate the effect of illumination, task difficulty, and task level on the mental workload of an individual operating an agricultural sprayer in response to a commercial GPS lightbar, and to explore the sensitivity of the NASA-TLX and SSWAT subjective rating scales in discriminating the subjective experienced workload under various task, illumination, and difficulty levels. Mental workload was measured using performance measures (lateral root mean square error and reaction time), physiological measures (0.1 Hz power of HRV, latency of the P300 component of event-related potential, and eye-glance behavior), and two subjective rating scales (NASA-TLX and SSWAT). Sixteen male university students participated in this experiment, and a fixed-base high-fidelity agricultural tractor simulator was used to create a simulated spraying task. All performance measures, the P300 latency, and subjective rating scales showed a common trend that mental workload increased with the change in illumination from day to night, with task difficulty from low to high, and with task type from single to dual. The 0.1 Hz power of HRV contradicted the performance measures. Eye-glance data showed that under night illumination, participants spent more time looking at the lightbar for guidance information. A similar trend was observed with the change in task type from single to dual. Both subjective rating scales showed a common trend of increasing mental workload with the change in illumination, difficulty, and task levels. However, the SSWAT scale was more sensitive than the NASA-TLX scale. With the change in illumination, difficulty, and task levels, participants spent more mental resources to meet the increased task demand; hence, the

  4. Human Injury Criteria for Underwater Blasts.

    PubMed

    Lance, Rachel M; Capehart, Bruce; Kadro, Omar; Bass, Cameron R

    2015-01-01

    Underwater blasts propagate further and injure more readily than equivalent air blasts. Development of effective personal protection and countermeasures, however, requires knowledge of the currently unknown human tolerance to underwater blast. Current guidelines for prevention of underwater blast injury are not based on any organized injury risk assessment, human data or experimental data. The goal of this study was to derive injury risk assessments for underwater blast using well-characterized human underwater blast exposures in the open literature. The human injury dataset was compiled using 34 case reports on underwater blast exposure to 475 personnel, dating as early as 1916. Using severity ratings, computational reconstructions of the blasts, and survival information from a final set of 262 human exposures, injury risk models were developed for both injury severity and risk of fatality as functions of blast impulse and blast peak overpressure. Based on these human data, we found that the 50% risk of fatality from underwater blast occurred at 302±16 kPa-ms impulse. Conservatively, there is a 20% risk of pulmonary injury at a kilometer from a 20 kg charge. From a clinical point of view, this new injury risk model emphasizes the large distances possible for potential pulmonary and gut injuries in water compared with air. This risk value is the first impulse-based fatality risk calculated from human data. The large-scale inconsistency between the blast exposures in the case reports and the guidelines available in the literature prior to this study further underscored the need for this new guideline derived from the unique dataset of actual injuries in this study.

  5. Human Injury Criteria for Underwater Blasts

    PubMed Central

    Lance, Rachel M.; Capehart, Bruce; Kadro, Omar; Bass, Cameron R.

    2015-01-01

    Underwater blasts propagate further and injure more readily than equivalent air blasts. Development of effective personal protection and countermeasures, however, requires knowledge of the currently unknown human tolerance to underwater blast. Current guidelines for prevention of underwater blast injury are not based on any organized injury risk assessment, human data or experimental data. The goal of this study was to derive injury risk assessments for underwater blast using well-characterized human underwater blast exposures in the open literature. The human injury dataset was compiled using 34 case reports on underwater blast exposure to 475 personnel, dating as early as 1916. Using severity ratings, computational reconstructions of the blasts, and survival information from a final set of 262 human exposures, injury risk models were developed for both injury severity and risk of fatality as functions of blast impulse and blast peak overpressure. Based on these human data, we found that the 50% risk of fatality from underwater blast occurred at 302±16 kPa-ms impulse. Conservatively, there is a 20% risk of pulmonary injury at a kilometer from a 20 kg charge. From a clinical point of view, this new injury risk model emphasizes the large distances possible for potential pulmonary and gut injuries in water compared with air. This risk value is the first impulse-based fatality risk calculated from human data. The large-scale inconsistency between the blast exposures in the case reports and the guidelines available in the literature prior to this study further underscored the need for this new guideline derived from the unique dataset of actual injuries in this study. PMID:26606655

  6. Human Injury Criteria for Underwater Blasts.

    PubMed

    Lance, Rachel M; Capehart, Bruce; Kadro, Omar; Bass, Cameron R

    2015-01-01

    Underwater blasts propagate further and injure more readily than equivalent air blasts. Development of effective personal protection and countermeasures, however, requires knowledge of the currently unknown human tolerance to underwater blast. Current guidelines for prevention of underwater blast injury are not based on any organized injury risk assessment, human data or experimental data. The goal of this study was to derive injury risk assessments for underwater blast using well-characterized human underwater blast exposures in the open literature. The human injury dataset was compiled using 34 case reports on underwater blast exposure to 475 personnel, dating as early as 1916. Using severity ratings, computational reconstructions of the blasts, and survival information from a final set of 262 human exposures, injury risk models were developed for both injury severity and risk of fatality as functions of blast impulse and blast peak overpressure. Based on these human data, we found that the 50% risk of fatality from underwater blast occurred at 302±16 kPa-ms impulse. Conservatively, there is a 20% risk of pulmonary injury at a kilometer from a 20 kg charge. From a clinical point of view, this new injury risk model emphasizes the large distances possible for potential pulmonary and gut injuries in water compared with air. This risk value is the first impulse-based fatality risk calculated from human data. The large-scale inconsistency between the blast exposures in the case reports and the guidelines available in the literature prior to this study further underscored the need for this new guideline derived from the unique dataset of actual injuries in this study. PMID:26606655

  7. Further evaluation of spray characterization of sprayers typically used in vector control.

    PubMed

    Hoffmann, W Clint; Walker, Todd W; Fritz, Bradley K; Farooq, Muhammad; Smith, Vincent L; Robinson, Cathy A; Lan, Yubin

    2012-06-01

    This work reports droplet-size data measured as part of a collaborative testing program between the US Department of Agriculture, Agricultural Research Service, and the US Navy, Navy Entomological Center for Excellence. This is an ongoing relationship that seeks to test new and revised spray technologies that may potentially be used by deployed personnel. As new equipment comes to market or when existing equipment is modified they are all integrated into this annual testing. During the 2011 equipment evaluations, 24 sprayers were operated across their range of available settings (pressure and flow rate), using both water and oil solutions. Droplet-size data as measured with laser diffraction ranged from 4 to 223 microm (volume median diameter). Generally, as the spray rate increased, droplet size increased, and as the pressure increased at a given same spray rate, droplet size decreased. This information allows users to set up and operate these sprayers in a manner such that a particular droplet size is applied optimizing efficiency and efficacy of applications. PMID:22894119

  8. Evaluation of a laser scanning sensor on detection of complex shaped targets for variable-rate sprayer development

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sensors that can accurately measure canopy structures are prerequisites for development of advanced variable-rate sprayers. A 270° radial range laser sensor was evaluated for its accuracy to measure dimensions of target surfaces with complex shapes and sizes. An algorithm for data acquisition and 3-...

  9. Modelling of blast loading on aboveground structures - I. General phenomenology and external blast

    NASA Astrophysics Data System (ADS)

    Beshara, F. B. A.

    1994-06-01

    The paper is concerned with the prediction of dynamic effects of unconfined explosions needed for the structural analysis of blast-loaded aboveground structures. The basic features of the explosion and blast wave phenomena are presented along with a discussion of TNT equivalency and blast scaling laws. The characteristics of incident overpressure loading due to atomic weapons, conventional high explosives and unconfined vapour cloud explosions are addressed and followed by a description of the other blast loading components associated with air flow and reflection process. In the final part, the modelling of external blast loads on the different faces of aboveground rigid structures is considered. A unified approach is followed in the presentation of the governing equations of modelling of blast loads for mathematical and practical applications.

  10. [The characteristics of blast traumatic brain injury].

    PubMed

    Matsumoto, Yoshihisa; Hatano, Ben; Matsushita, Yoshitaro; Nawashiro, Hiroshi; Shima, Katsuji

    2010-08-01

    With the increase in terrorist activity in recent times, the number of blast injuries has also increased in civilian and military settings. In a recent war, the number of patients who suffered blast traumatic brain injury (bTBI) increased, so treatment of bTBI is currently a very important issue. Blast injury is complicated and can be divided into 4 categories: primary, secondary, tertiary, and quaternary. Primary blast injury results from exposure to blast waves; secondary blast injury is trauma caused by fragments of explosive devices; tertiary blast injury is the result of collision with objects; and quaternary blast injury is the result of exposure to toxic and other substances. Blast waves mainly injure air-containing organs such as the lung, bowel, and ear. The brain may also be affected by blast waves. From the clinical perspective, hyperemia and severe cerebral edema occur frequently in patients who sustain significant bTBI. Penetrating or closed head injury caused by the explosion may be associated with vasospasm and pseudoaneurysm formation. Mild traumatic brain injury during war can be associated with posttraumatic stress disorder. To elucidate the mechanism of bTBI, many research works using animal models and computer analysis are underway. Such studies have so far shown that blast waves can cause damage to the brain tissue and cognitive deficits; however, detailed investigations on this topic are still required. Treatment of bTBI patients may require clinical knowledge and skills related to intensive care, neurology, and neurosurgery. Moreover, further research is required in this field. PMID:20697143

  11. Management of primary blast injury.

    PubMed

    Argyros, G J

    1997-07-25

    Blast waves are produced following the detonation of munitions, the firing of large caliber guns, or from any type of explosion. These blast waves can be powerful enough to injure the individuals exposed to them. This type of injury is called primary blast injury (PBI) and the organs most vulnerable to PBI are the gas-filled organs, namely the ear, the lungs and the gastrointestinal tract. The approach to the casualty with PBI is the same as it would be for any trauma victim, i.e. the initiation of life support measures. Attention should be directed to the common life-threatening manifestation of thoracic and abdominal PBI. Pulmonary manifestations would include hemorrhage, barotrauma and arterial air embolism, while abdominal manifestations would include hemorrhage and hollow organ rupture. Therapy is directed at the specific manifestations as well as avoiding additional iatrogenic injury. PMID:9217319

  12. Factors Affecting Internal Blast

    NASA Astrophysics Data System (ADS)

    Granholm, R. H.; Sandusky, H. W.; Felts, J. E.

    2007-12-01

    Internal blast refers to explosion effects in confined spaces, which are dominated by the heat output of the explosive. Theoretical temperatures and pressures may not be reached due to heat losses and incomplete gas mixing. Gas mixing can have the largest effect, potentially reducing peak quasi-static pressure by a factor of two due to lack of thermal equilibrium between products and atmosphere in the space, separate from the effect of incomplete combustion of excess fuel when that atmosphere is air. Chamber and test geometry affect gas mixing, which has been inferred through temperature and pressure measurements and compared to calculations. Late-time combustion is observed for TNT compared to HMX.

  13. Utilizing a Robotic Sprayer for High Lateral and Mass Resolution MALDI FT-ICR MSI of Microbial Cultures.

    PubMed

    Anderton, Christopher R; Chu, Rosalie K; Tolić, Nikola; Creissen, Alain; Paša-Tolić, Ljiljana

    2016-03-01

    The ability to visualize biochemical interactions between microbial communities using MALDI MSI has provided tremendous insights into a variety of biological fields. Matrix application using a sieve proved to be incredibly useful, but it has many limitations that include uneven matrix coverage and limitation in the types of matrices that could be employed in studies. Recently, there has been a concerted effort to improve matrix application for studying agar plated microbial cultures, many of which utilized automated matrix sprayers. Here, we describe the usefulness of using a robotic sprayer for matrix application. The robotic sprayer has two-dimensional control over where matrix is applied, and a heated capillary that allows for rapid drying of the applied matrix. This method provided a significant increase in MALDI sensitivity over the sieve method, as demonstrated by FT-ICR MS analysis, facilitating the ability to gain higher lateral resolution MS images of Bacillus subtilis than previously reported. This method also allowed for the use of different matrices to be applied to the culture surfaces. PMID:26729451

  14. Utilizing a Robotic Sprayer for High Lateral and Mass Resolution MALDI FT-ICR MSI of Microbial Cultures

    NASA Astrophysics Data System (ADS)

    Anderton, Christopher R.; Chu, Rosalie K.; Tolić, Nikola; Creissen, Alain; Paša-Tolić, Ljiljana

    2016-03-01

    The ability to visualize biochemical interactions between microbial communities using MALDI MSI has provided tremendous insights into a variety of biological fields. Matrix application using a sieve proved to be incredibly useful, but it has many limitations that include uneven matrix coverage and limitation in the types of matrices that could be employed in studies. Recently, there has been a concerted effort to improve matrix application for studying agar plated microbial cultures, many of which utilized automated matrix sprayers. Here, we describe the usefulness of using a robotic sprayer for matrix application. The robotic sprayer has two-dimensional control over where matrix is applied, and a heated capillary that allows for rapid drying of the applied matrix. This method provided a significant increase in MALDI sensitivity over the sieve method, as demonstrated by FT-ICR MS analysis, facilitating the ability to gain higher lateral resolution MS images of Bacillus subtilis than previously reported. This method also allowed for the use of different matrices to be applied to the culture surfaces.

  15. Blast waves produced by interactions of femtosecond laser pulses with water.

    PubMed

    Li, Y T; Zhang, J; Teng, H; Li, K; Peng, X Y; Jin, Z; Lu, X; Zheng, Z Y; Yu, Q Z

    2003-05-01

    The behaviors of the blast waves produced by femtosecond laser-water interactions, and the blast waves induced by laser self-focusing in air, have been investigated using optical shadowgraphy at a maximum intensity of 1 x 10(16) W/cm(2). The temporal evolution of the blast wave launched by the water plasma can be described by a planar blast wave model including source mass. An aneurismlike structure, due to the quick propagation inside a hollow channel formed by laser self-focusing, is observed. The expansion of the channel in air is found to agree with a cylindrical self-similar blast wave solution. PMID:12786283

  16. 2. View of blast deflector fences along northeast side of ...

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

    2. View of blast deflector fences along northeast side of the operational apron. View to northwest. - Offutt Air Force Base, Looking Glass Airborne Command Post, Blast Deflector Fences, Northeast & Southwest sides of Operational Apron, Project Looking Glass Historic District, Bellevue, Sarpy County, NE

  17. 1. View of blast deflector fences along southwest side of ...

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

    1. View of blast deflector fences along southwest side of the operational apron. View to west. - Offutt Air Force Base, Looking Glass Airborne Command Post, Blast Deflector Fences, Northeast & Southwest sides of Operational Apron, Project Looking Glass Historic District, Bellevue, Sarpy County, NE

  18. A Multi-Mode Shock Tube for Investigation of Blast-Induced Traumatic Brain Injury

    PubMed Central

    Reneer, Dexter V.; Hisel, Richard D.; Hoffman, Joshua M.; Kryscio, Richard J.; Lusk, Braden T.

    2011-01-01

    Abstract Blast-induced mild traumatic brain injury (bTBI) has become increasingly common in recent military conflicts. The mechanisms by which non-impact blast exposure results in bTBI are incompletely understood. Current small animal bTBI models predominantly utilize compressed air-driven membrane rupture as their blast wave source, while large animal models use chemical explosives. The pressure-time signature of each blast mode is unique, making it difficult to evaluate the contributions of the different components of the blast wave to bTBI when using a single blast source. We utilized a multi-mode shock tube, the McMillan blast device, capable of utilizing compressed air- and compressed helium-driven membrane rupture, and the explosives oxyhydrogen and cyclotrimethylenetrinitramine (RDX, the primary component of C-4 plastic explosives) as the driving source. At similar maximal blast overpressures, the positive pressure phase of compressed air-driven blasts was longer, and the positive impulse was greater, than those observed for shockwaves produced by other driving sources. Helium-driven shockwaves more closely resembled RDX blasts, but by displacing air created a hypoxic environment within the shock tube. Pressure-time traces from oxyhydrogen-driven shockwaves were very similar those produced by RDX, although they resulted in elevated carbon monoxide levels due to combustion of the polyethylene bag used to contain the gases within the shock tube prior to detonation. Rats exposed to compressed air-driven blasts had more pronounced vascular damage than those exposed to oxyhydrogen-driven blasts of the same peak overpressure, indicating that differences in blast wave characteristics other than peak overpressure may influence the extent of bTBI. Use of this multi-mode shock tube in small animal models will enable comparison of the extent of brain injury with the pressure-time signature produced using each blast mode, facilitating evaluation of the blast wave

  19. A multi-mode shock tube for investigation of blast-induced traumatic brain injury.

    PubMed

    Reneer, Dexter V; Hisel, Richard D; Hoffman, Joshua M; Kryscio, Richard J; Lusk, Braden T; Geddes, James W

    2011-01-01

    Blast-induced mild traumatic brain injury (bTBI) has become increasingly common in recent military conflicts. The mechanisms by which non-impact blast exposure results in bTBI are incompletely understood. Current small animal bTBI models predominantly utilize compressed air-driven membrane rupture as their blast wave source, while large animal models use chemical explosives. The pressure-time signature of each blast mode is unique, making it difficult to evaluate the contributions of the different components of the blast wave to bTBI when using a single blast source. We utilized a multi-mode shock tube, the McMillan blast device, capable of utilizing compressed air- and compressed helium-driven membrane rupture, and the explosives oxyhydrogen and cyclotrimethylenetrinitramine (RDX, the primary component of C-4 plastic explosives) as the driving source. At similar maximal blast overpressures, the positive pressure phase of compressed air-driven blasts was longer, and the positive impulse was greater, than those observed for shockwaves produced by other driving sources. Helium-driven shockwaves more closely resembled RDX blasts, but by displacing air created a hypoxic environment within the shock tube. Pressure-time traces from oxyhydrogen-driven shockwaves were very similar those produced by RDX, although they resulted in elevated carbon monoxide levels due to combustion of the polyethylene bag used to contain the gases within the shock tube prior to detonation. Rats exposed to compressed air-driven blasts had more pronounced vascular damage than those exposed to oxyhydrogen-driven blasts of the same peak overpressure, indicating that differences in blast wave characteristics other than peak overpressure may influence the extent of bTBI. Use of this multi-mode shock tube in small animal models will enable comparison of the extent of brain injury with the pressure-time signature produced using each blast mode, facilitating evaluation of the blast wave components

  20. Automated Blast Cleaner

    NASA Technical Reports Server (NTRS)

    Pickett, Isaiah R.; Yulfo, Alyce R.

    1992-01-01

    Automatic grit-blasting machine removes melted-layer residue from electrical-discharge-machined surfaces of turbine blades. Automatic control system of machine provides steady flow of grit and maintains blast nozzles at proper distance and in correct orientation perpendicular to surface being blasted, regardless of contour. Eliminates localized excessive blasting and consequent excessive removal of underlying material, blasting of adjacent surfaces, and missed areas.

  1. Note: Device for underwater laboratory simulation of unconfined blast waves

    NASA Astrophysics Data System (ADS)

    Courtney, Elijah; Courtney, Amy; Courtney, Michael

    2015-06-01

    Shock tubes simulate blast waves to study their effects in air under laboratory conditions; however, few experimental models exist for simulating underwater blast waves that are needed for facilitating experiments in underwater blast transmission, determining injury thresholds in marine animals, validating numerical models, and exploring mitigation strategies for explosive well removals. This method incorporates an oxy-acetylene driven underwater blast simulator which creates peak blast pressures of about 1860 kPa. Shot-to-shot consistency was fair, with an average standard deviation near 150 kPa. Results suggest that peak blast pressures from 460 kPa to 1860 kPa are available by adjusting the distance from the source.

  2. Note: Device for underwater laboratory simulation of unconfined blast waves.

    PubMed

    Courtney, Elijah; Courtney, Amy; Courtney, Michael

    2015-06-01

    Shock tubes simulate blast waves to study their effects in air under laboratory conditions; however, few experimental models exist for simulating underwater blast waves that are needed for facilitating experiments in underwater blast transmission, determining injury thresholds in marine animals, validating numerical models, and exploring mitigation strategies for explosive well removals. This method incorporates an oxy-acetylene driven underwater blast simulator which creates peak blast pressures of about 1860 kPa. Shot-to-shot consistency was fair, with an average standard deviation near 150 kPa. Results suggest that peak blast pressures from 460 kPa to 1860 kPa are available by adjusting the distance from the source. PMID:26133878

  3. Blast furnace supervision and control system

    SciTech Connect

    Remorino, M.; Lingiardi, O.; Zecchi, M.

    1997-12-31

    On December 1992, a group of companies headed by Techint, took over Somisa, the state-owned integrated steel plant located at San Nicolas, Province of Buenos Aires, Argentina, culminating an ambitious government privatization scheme. The blast furnace 2 went into a full reconstruction and relining in January 1995. After a 140 MU$ investment the new blast furnace 2 was started in September 1995. After more than one year of operation of the blast furnace the system has proven itself useful and reliable. The main reasons for the success of the system are: same use interface for all blast furnace areas -- operation, process, maintenance and management, (full horizontal and vertical integration); and full accessibility to all information and process tools though some restrictions apply to field commands (people empowerment). The paper describes the central system.

  4. 24. GENERAL VIEW OF NEW CONCRETE BLAST BERM FOR NEW ...

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

    24. GENERAL VIEW OF NEW CONCRETE BLAST BERM FOR NEW LIQUID HYDROGEN TANK FARM; VIEW TO EAST. - Cape Canaveral Air Station, Launch Complex 17, Facility 28402, East end of Lighthouse Road, Cape Canaveral, Brevard County, FL

  5. Computer modeling of thoracic response to blast.

    PubMed

    Stuhmiller, J H; Chuong, C J; Phillips, Y Y; Dodd, K T

    1988-01-01

    Primary blast injury affects the gas-containing structures of the body. Damage to the lungs with resultant respiratory insufficiency and arterial embolization of air from alveolar pulmonary venous fistulae is the predominant cause of morbidity and mortality following high-level blast exposure. In an effort to generate a widely applicable damage-risk criterion for thoracic injury from blast we are developing a complex computer finite element model (FEM) of the thorax. Taking an engineering approach, a horizontal cross-section of the thorax is divided into small discrete units (finite elements) of homogeneous structure. The necessary physical properties (density, bulk modulus, etc.) are then determined for each element. Specifying the material constants and geometry of the elements, the computer can load the surface of the structure with some force-time function (blast pressure-time history) and calculate the resultant physical events such as displacement, compression, stress, strain, etc. Computer predictions of pressure wave phenomena in the lung parenchyma are compared with trans-bronchially measured pressures in blast-exposed animals. The model should prove useful in assessing the risk of blast injury in diverse overpressure environments and may give insight into pathophysiologic mechanisms and strategies for protection.

  6. A new approach to oxygen enriched high temperature blast generation

    SciTech Connect

    Queille, P.H.; Macauley, D.

    1996-12-31

    When increasing fuel injection in a blast furnace in order to reduce coke consumption and/or to increase production, the blast furnace operator tries to keep similar raceway conditions, for instance, an equivalent flame temperature. To compensate for the cooling effect due to the higher injection rate, two solutions can be selected or combined: to raise the temperature of the blast and/or to increase the level of oxygen in the blast. Whatever the choice, the Blast Furnace manager will certainly try to reduce the resulting investment and operating costs to a minimum. Air Liquide and Kvaerner Davy are trying to provide a new way to address these needs by offering a new technology for blast heating. A higher blast temperature will not only allow a higher fuel injection at tuyere level, a lower coke consumption, but also a lower oxygen consumption. Air Liquide and Kvaerner Davy are now able to offer a new heat regenerator with major advantages over conventional stoves. This new device can be used as a permanent substitute for a stove, or as a temporary one during repair, or stove improvement. It can also be added to an existing set of stoves to increase the average blast temperature.

  7. Close-in Blast Waves from Spherical Charges*

    NASA Astrophysics Data System (ADS)

    Howard, William; Kuhl, Allen

    2011-06-01

    We study the close-in blast waves created by the detonation of spherical high explosives (HE) charges, via numerical simulations with our Arbitrary-Lagrange-Eulerian (ALE3D) code. We used a finely-resolved, fixed Eulerian 2-D mesh (200 μm per cell) to capture the detonation of the charge, the blast wave propagation in air, and the reflection of the blast wave from an ideal surface. The thermodynamic properties of the detonation products and air were specified by the Cheetah code. A programmed-burn model was used to detonate the charge at a rate based on measured detonation velocities. The results were analyzed to evaluate the: (i) free air pressure-range curves: Δps (R) , (ii) free air impulse curves, (iii) reflected pressure-range curves, and (iv) reflected impulse-range curves. A variety of explosives were studied. Conclusions are: (i) close-in (R < 10 cm /g 1 / 3) , each explosive had its own (unique) blast wave (e.g., Δps (R , HE) ~ a /Rn , where n is different for each explosive); (ii) these close-in blast waves do not scale with the ``Heat of Detonation'' of the explosive (because close-in, there is not enough time to fully couple the chemical energy to the air via piston work); (iii) instead they are related to the detonation conditions inside the charge. Scaling laws will be proposed for such close-in blast waves.

  8. Modern BLAST Programs

    NASA Astrophysics Data System (ADS)

    Ma, Jian; Zhang, Louxin

    The Basic Local Alignment Search Tool (BLAST) is arguably the most widely used program in bioinformatics. By sacrificing sensitivity for speed, it makes sequence comparison practical on huge sequence databases currently available. The original version of BLAST was developed in 1990. Since then it has spawned a variant of specialized programs. This chapter surveys the development of BLAST and BLAST-like programs for homology search, discusses alignment statistics that are used in assessment of reported matches in BLAST, and provides the reader with guidance to select appropriate programs and set proper parameters to match research requirements.

  9. Recent improvements in casthouse practices at the Kwangyang blast furnaces

    SciTech Connect

    Jang, Y.S.; Han, K.W.; Kim, K.Y.; Cho, B.R.; Hur, N.S.

    1997-12-31

    POSCO`s Kwangyang blast furnaces have continuously carried out high production and low fuel operation under a high pulverized coal injection rate without complications since the Kwangyang No. 1 blast furnace was blown-in in 1987. The Kwangyang blast furnaces have focused on improving the work environment for the increase of competitive power in terms of increased production, cost savings, and management of optimum manpower through use of low cost fuel and raw material. At this time, the casthouse work lags behind most work in the blast furnace. Therefore, the Kwangyang blast furnaces have adopted a remote control system for the casthouse equipment to solve complications in the casthouse work due to high temperature and fumes. As the result, the casthouse workers can work in clean air and the number of workers has been reduced to 9.5 personnel per shift by reduction of the workload.

  10. The past and present of blast injury research in China.

    PubMed

    Zhao, Yan; Zhou, Yuan-Guo

    2015-01-01

    With the increasing incidence of blast injury, the research on its mechanisms and protective measures draws more and more attention. Blast injury has many characteristics different from general war injuries or trauma. For example, soldiers often have various degrees of visceral injury without significant surface damage, combined injuries and arterial air embolism. Researchers in China began to investigate blast injury later than the United States and Sweden, but the development is so fast that lots of achievements have been gained, including the development of biological shock tube, the mechanisms and characteristics of blast injury in various organs, as well as protective measures under special environments. This article reviews the past and current situation of blast injury research in China.

  11. Performance of Novel Composites and Sandwich Structures Under Blast Loading

    NASA Astrophysics Data System (ADS)

    Shukla, Arun; Tekalur, Srinivasan Arjun; Gardner, Nate; Jackson, Matt; Wang, Erheng

    The current chapter focuses on the experimental observations of the resistance of different composite material systems to air blast loadings. These material systems include traditional two dimensional (2D) woven laminated composites, layered composites and sandwich composite materials. A controlled blast loading of pre-defined pressure magnitude and rise time were obtained using a shock tube apparatus. Rectangular plate elements of the desired material system were subjected to such a controlled blast loading and the effect of the blast loading on these elements were studied using optical and residual strength measurements. A high speed imaging technique was utilized to study the damage modes and mechanisms in real time. It was observed that layering of a conventional composite material with a soft visco-elastic polymer provided better blast resistance and sandwiching the polymer greatly enhanced its survivability under extreme air blast conditions. Aside from layering the conventional composite material with a soft visco-elastic polymer, it was observed that layering or grading the core can successfully mitigate the impact damage and thus improve the overall blast resistance as well. In addition to these, three dimensional (3D) woven skin and core reinforcements were introduced in the conventional sandwich composites and their effects on the blast resistance were studied experimentally. It was observed that these reinforcements also enhance the blast resistance of conventional sandwich composites by changing the mechanism of failure initiation and propagation in these sandwich structures. The energies during the blast loading process were estimated to illustrate the energy absorption and energy redistribution properties of the composite panels. The effect of pre-existing impact damage on the failure mechanisms in sandwich structures was also studied.

  12. Blast assessment and optimization for high quarry face-blasting

    SciTech Connect

    Sames, F.; O`Meara, R.

    1996-12-01

    Where applicable, high production benches can improve efficiency in quarrying. Quality control, geological, cost or other considerations might result in the development of quarry benches higher than 30 m and sometimes up to 60 m. Production blasts on high quarry faces require a confident blast design with respect to safety, cost efficiency and minimized environmental effects. Careful pre-blast assessment of the design parameters, blast monitoring of the product performance and the environmental effects and post-blast assessment of the overall blast performance are essential for the successful implementation of the blast design. The blast geometry for high quarry faces and a blast design that often includes multiple explosive charges in a blasthole, make a reliable assessment of the blast parameters difficult. Assessment techniques, their applications and limitations are described and discussed. This will include such methods as blast surveying using laser profiling and borehole deviation measurements, blast monitoring using continuous velocity of detonation measurement systems, high speed photography and seismographs for blast performance and environmental effects. Observations of low frequency airblast and high standard deviations in ground vibration measurements are described and discussed against a background of timing assessment and frequency spectra analysis. Approaches where an optimized design was implemented based on the blast parameter assessment and modeling are presented. An improvement in blast efficiency lies in the combination of blast assessment and blast modeling, whilst adequate documentation supports the process of designing and implementing successful blasts.

  13. Compressive strength after blast of sandwich composite materials

    PubMed Central

    Arora, H.; Kelly, M.; Worley, A.; Del Linz, P.; Fergusson, A.; Hooper, P. A.; Dear, J. P.

    2014-01-01

    Composite sandwich materials have yet to be widely adopted in the construction of naval vessels despite their excellent strength-to-weight ratio and low radar return. One barrier to their wider use is our limited understanding of their performance when subjected to air blast. This paper focuses on this problem and specifically the strength remaining after damage caused during an explosion. Carbon-fibre-reinforced polymer (CFRP) composite skins on a styrene–acrylonitrile (SAN) polymer closed-cell foam core are the primary composite system evaluated. Glass-fibre-reinforced polymer (GFRP) composite skins were also included for comparison in a comparable sandwich configuration. Full-scale blast experiments were conducted, where 1.6×1.3 m sized panels were subjected to blast of a Hopkinson–Cranz scaled distance of 3.02 m kg−1/3, 100 kg TNT equivalent at a stand-off distance of 14 m. This explosive blast represents a surface blast threat, where the shockwave propagates in air towards the naval vessel. Hopkinson was the first to investigate the characteristics of this explosive air-blast pulse (Hopkinson 1948 Proc. R. Soc. Lond. A 89, 411–413 (doi:10.1098/rspa.1914.0008)). Further analysis is provided on the performance of the CFRP sandwich panel relative to the GFRP sandwich panel when subjected to blast loading through use of high-speed speckle strain mapping. After the blast events, the residual compressive load-bearing capacity is investigated experimentally, using appropriate loading conditions that an in-service vessel may have to sustain. Residual strength testing is well established for post-impact ballistic assessment, but there has been less research performed on the residual strength of sandwich composites after blast. PMID:24711494

  14. Compressive strength after blast of sandwich composite materials.

    PubMed

    Arora, H; Kelly, M; Worley, A; Del Linz, P; Fergusson, A; Hooper, P A; Dear, J P

    2014-05-13

    Composite sandwich materials have yet to be widely adopted in the construction of naval vessels despite their excellent strength-to-weight ratio and low radar return. One barrier to their wider use is our limited understanding of their performance when subjected to air blast. This paper focuses on this problem and specifically the strength remaining after damage caused during an explosion. Carbon-fibre-reinforced polymer (CFRP) composite skins on a styrene-acrylonitrile (SAN) polymer closed-cell foam core are the primary composite system evaluated. Glass-fibre-reinforced polymer (GFRP) composite skins were also included for comparison in a comparable sandwich configuration. Full-scale blast experiments were conducted, where 1.6×1.3 m sized panels were subjected to blast of a Hopkinson-Cranz scaled distance of 3.02 m kg(-1/3), 100 kg TNT equivalent at a stand-off distance of 14 m. This explosive blast represents a surface blast threat, where the shockwave propagates in air towards the naval vessel. Hopkinson was the first to investigate the characteristics of this explosive air-blast pulse (Hopkinson 1948 Proc. R. Soc. Lond. A 89, 411-413 (doi:10.1098/rspa.1914.0008)). Further analysis is provided on the performance of the CFRP sandwich panel relative to the GFRP sandwich panel when subjected to blast loading through use of high-speed speckle strain mapping. After the blast events, the residual compressive load-bearing capacity is investigated experimentally, using appropriate loading conditions that an in-service vessel may have to sustain. Residual strength testing is well established for post-impact ballistic assessment, but there has been less research performed on the residual strength of sandwich composites after blast.

  15. Experimental Studies of Mitigation Materials for Blast Induced Tbi

    NASA Astrophysics Data System (ADS)

    Alley, M. D.; Son, S. F.; Christou, G.; Goel, R.; Young, L.

    2009-12-01

    The objective of this experimental study is to compare the effects of various materials obstructing the flow of a blast wave and the ability of the material to reduce the damage caused by the blast. Several methods of energy transfer in blast wave flows are expected including: material interfaces with impedance mismatches, density changes in a given material, internal shearing, and particle fracture. Our hypothesis is that the greatest energy transfer within the obstructing material will yield the greatest mitigation effects to the blast. Sample configurations of foam were varied to introduce material interfaces and filler materials with varying densities and impedances (liquids and powders). The samples were dynamically loaded using a small scale blast produced by an explosive driven shock tube housing gram-scale explosive charges. The transmitted blast profiles were analyzed for variations in impulse characteristics and frequency components as compared to standard free field profiles. The results showed a rounding effect of the transmitted blast profile for all samples with the effects of the high density fillers surpassing all others tested. These results lead to a conclusion that low porosity, high density materials offer superior attenuation by reducing air blast features and spatially distributing the transmitted wave.

  16. Hot blast stove process model and model-based controller

    SciTech Connect

    Muske, K.R.; Howse, J.W.; Hansen, G.A.; Cagliostro, D.J.; Chaubal, P.C.

    1998-12-31

    This paper describes the process model and model-based control techniques implemented on the hot blast stoves for the No. 7 Blast Furnace at the Inland Steel facility in East Chicago, Indiana. A detailed heat transfer model of the stoves is developed and verified using plant data. This model is used as part of a predictive control scheme to determine the minimum amount of fuel necessary to achieve the blast air requirements. The model is also used to predict maximum and minimum temperature constraint violations within the stove so that the controller can take corrective actions while still achieving the required stove performance.

  17. The influence of personal blast protection on the distribution and severity of primary blast gut injury.

    PubMed

    Cripps, N P; Cooper, G J

    1996-03-01

    Primary blast injuries have been recognized since World War I when the most significant reported injury was to the lung. The prevalence of injury to tissues containing air was underlined by the frequency of gut blast injury in underwater explosions mostly reported during World War II. Gut injury is the most likely cause of mortality after the more immediate effects of pulmonary primary blast injury. Effective protection has been achieved for lungs exposed to short duration external blast waves by the placement of stress wave decouplers on to the thoracoabdominal wall in a pig model, thus modifying the energy coupled into the body. A combination of two densities of glass-reinforced plastic plate and Plastazote foam (GRP/PZ) effectively eliminated pulmonary injury in 17 protected animals, compared with the production of severe blast lung in nine unprotected animals (p < 0.001). Partial pulmonary protection was achieved using a plasticized lead and plastazote foam decoupling combination (PbPVC/PZ) in a further group of 10 animals. Peak incident overpressures were not significantly different in any group. Small bowel contusions were highly significantly reduced in the GRP/PZ groups when compared with unprotected animals and with PbPVC protected animals (both p < 0.001); no significant reduction was observed in the summed colonic contusion size in any protected group. Intestinal perforations were also highly significantly reduced in both GRP/PZ groups (p < 0.001). Primary pulmonary blast injury and probably small bowel injury are caused by the propagation of coupled stress waves within the body. Elimination of these injuries implies prevention of stress wave propagation. Because colonic injury was not prevented by the same protection, a different mechanism for the injury is suggested: transmission and propagation of shear waves. These findings have important implications for blast protection and the clinical management of primary blast casualties. PMID:8606411

  18. Bomb blast mass casualty incidents: initial triage and management of injuries.

    PubMed

    Goh, S H

    2009-01-01

    Bomb blast injuries are no longer confined to battlefields. With the ever present threat of terrorism, we should always be prepared for bomb blasts. Bomb blast injuries tend to affect air-containing organs more, as the blast wave tends to exert a shearing force on air-tissue interfaces. Commonly-injured organs include the tympanic membranes, the sinuses, the lungs and the bowel. Of these, blast lung injury is the most challenging to treat. The clinical picture is a mix of acute respiratory distress syndrome and air embolism, and the institution of positive pressure ventilation in the presence of low venous pressures could cause systemic arterial air embolism. The presence of a tympanic membrane perforation is not a reliable indicator of the presence of a blast injury in the other air-containing organs elsewhere. Radiological imaging of the head, chest and abdomen help with the early identification of blast lung injury, head injury, abdominal injury, eye and sinus injuries, as well as any penetration by foreign bodies. In addition, it must be borne in mind that bomb blasts could also be used to disperse radiological and chemical agents. PMID:19224092

  19. Dry ice blasting

    NASA Astrophysics Data System (ADS)

    Lonergan, Jeffrey M.

    1992-04-01

    As legal and societal pressures against the use of hazardous waste generating materials has increased, so has the motivation to find safe, effective, and permanent replacements. Dry ice blasting is a technology which uses CO2 pellets as a blasting medium. The use of CO2 for cleaning and stripping operations offers potential for significant environmental, safety, and productivity improvements over grit blasting, plastic media blasting, and chemical solvent cleaning. Because CO2 pellets break up and sublime upon impact, there is no expended media to dispose of. Unlike grit or plastic media blasting which produce large quantities of expended media, the only waste produced by CO2 blasting is the material removed. The quantity of hazardous waste produced, and thus the cost of hazardous waste disposal is significantly reduced.

  20. Molecular Changes and Vision Loss in a Mouse Model of Closed-Globe Blast Trauma

    PubMed Central

    Bricker-Anthony, Courtney; Hines-Beard, Jessica; Rex, Tonia S.

    2014-01-01

    Purpose. To characterize retinal changes and assess vision after an eye-directed air blast. Methods. Adult C57Bl/6 mice were exposed to a blast directed at one eye. Optical coherence tomography and histology were performed to assess retina and optic nerve integrity. Cell death, oxidative stress, and glial reactivity were examined by immunohistochemistry. Visual changes were measured by ERG recordings and the optokinetic reflex. Results. In the outer retina, eye blast caused retinal pigment epithelium vacuoles and rare retinal detachments followed by regional cell death. Labeling for nitrotyrosine and markers of pyroptosis (caspase-1) and necroptosis (receptor-interacting protein kinases-1, -3) increased, primarily in the inner retina, after blast. Caspase-1 labeling was restricted primarily to the starburst amacrine cells. A few degenerating axons were detected at 28 days post blast. Despite a lack of substantial cell death or decreased ERG, there was a deficit in visual acuity after blast. Conclusions. Oxidative stress, neuroinflammation, and cell death became increasingly prevalent, over time post blast suggestive of an ongoing neurodegenerative response. Outer retinal changes either resolved or remained focal. In contrast, inner retinal changes were more robust and spread from focal regions to the entire retina over time post blast. Our model of eye blast trauma causes molecular changes and a decrease in visual acuity within the first month post blast despite a lack of overt eye injury. This subtle response matches the delayed presentation of visual deficits in some blast-exposed Veterans. PMID:24994864

  1. Blast injury research models

    PubMed Central

    Kirkman, E.; Watts, S.; Cooper, G.

    2011-01-01

    Blast injuries are an increasing problem in both military and civilian practice. Primary blast injury to the lungs (blast lung) is found in a clinically significant proportion of casualties from explosions even in an open environment, and in a high proportion of severely injured casualties following explosions in confined spaces. Blast casualties also commonly suffer secondary and tertiary blast injuries resulting in significant blood loss. The presence of hypoxaemia owing to blast lung complicates the process of fluid resuscitation. Consequently, prolonged hypotensive resuscitation was found to be incompatible with survival after combined blast lung and haemorrhage. This article describes studies addressing new forward resuscitation strategies involving a hybrid blood pressure profile (initially hypotensive followed later by normotensive resuscitation) and the use of supplemental oxygen to increase survival and reduce physiological deterioration during prolonged resuscitation. Surprisingly, hypertonic saline dextran was found to be inferior to normal saline after combined blast injury and haemorrhage. New strategies have therefore been developed to address the needs of blast-injured casualties and are likely to be particularly useful under circumstances of enforced delayed evacuation to surgical care. PMID:21149352

  2. Laboratory Blast Testing Methodologies

    NASA Astrophysics Data System (ADS)

    Needham, C.; Rule, G.

    Blast-induced injuries remain a critical problem facing US Forces during combat operations. As the nature of modern warfare has evolved, it is likely that the Improvised Explosive Device (IED) will remain a common battlefield threat for the foreseeable future. Thus, research devoted to improving protection, and characterizing the physiological response of people and equipment to blast exposure is and will remain a major thrust area for the DOD. Unfortunately, exact reproduction or simulation of the blast environment is technically challenging, while measuring and characterizing blast exposures is even more complex.

  3. General view of blast furnace plant, with blast furnace "A" ...

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

    General view of blast furnace plant, with blast furnace "A" (built in 1907) to the left; in the foreground is the turbo-blower and blast furnace gas-powered electric generating station (built in 1919), looking northwest - Bethlehem Steel Corporation, South Bethlehem Works, Blast Furnace "A", Along Lehigh River, North of Fourth Street, West of Minsi Trail Bridge, Bethlehem, Northampton County, PA

  4. Development of a real-time chemical injection system for air-assisted variable-rate sprayers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A chemical injection system is an effective method to minimize chemical waste and reduce the environmental pollution in pesticide spray applications. A microprocessor controlled injection system implementing a ceramic piston metering pump was developed to accurately dispense chemicals to be mixed wi...

  5. Operation Greenhouse. Scientific Director's report. Annex 1. 6. Blast measurements. Part 2. Free-air peak-pressure measurements. Section 1. Nuclear explosions, 1951

    SciTech Connect

    Moulton, J.F.; Simonds, B.T.

    1984-10-31

    The primary objective of this experiment was to obtain accurate information on the pressure in the shock wave in the free-air region. In particular, it was desired to know the peak pressure as a function of distance in this region. Secondary objectives were to determine the path of the triple point and to determine the peak pressure in the Mach-stem region.

  6. Lightweight blast shield

    DOEpatents

    Mixon, Larry C.; Snyder, George W.; Hill, Scott D.; Johnson, Gregory L.; Wlodarski, J. Frank; von Spakovsky, Alexis P.; Emerson, John D.; Cole, James M.; Tipton, John P.

    1991-01-01

    A tandem warhead missile arrangement that has a composite material housing structure with a first warhead mounted at one end and a second warhead mounted near another end of the composite structure with a dome shaped composite material blast shield mounted between the warheads to protect the second warhead from the blast of the first warhead.

  7. Mechanical and histological characterization of trachea tissue subjected to blast-type pressures

    NASA Astrophysics Data System (ADS)

    Butler, B. J.; Bo, C.; Tucker, A. W.; Jardine, A. P.; Proud, W. G.; Williams, A.; Brown, K. A.

    2014-05-01

    Injuries to the respiratory system can be a component of polytrauma in blast-loading injuries. Tissues located at air-liquid interfaces, including such tissues in the respiratory system, are particularly vulnerable to damage by blast overpressures. There is a lack of information about the mechanical and cellular responses that contribute to the damage of this class of tissues subjected to the high strain rates associated with blast loading. Here, we describe the results of dynamic blast-like pressure loading tests at high strain rates on freshly harvested ex vivo trachea tissue specimens.

  8. Blast wave energy diagnostic.

    PubMed

    Tierney, Thomas E; Tierney, Heidi E; Idzorek, George C; Watt, Robert G; Peterson, Robert R; Peterson, Darrell L; Fryer, Christopher L; Lopez, Mike R; Jones, Michael C; Sinars, Daniel; Rochau, Gregory A; Bailey, James E

    2008-10-01

    The distance radiation waves that supersonically propagate in optically thick, diffusive media are energy sensitive. A blast wave can form in a material when the initially diffusive, supersonic radiation wave becomes transonic. Under specific conditions, the blast wave is visible with radiography as a density perturbation. [Peterson et al., Phys. Plasmas 13, 056901 (2006)] showed that the time-integrated drive energy can be measured using blast wave positions with uncertainties less than 10% at the Z Facility. In some cases, direct measurements of energy loss through diagnostic holes are not possible with bolometric and x-ray radiometric diagnostics. Thus, radiography of high compression blast waves can serve as a complementary technique that provides time-integrated energy loss through apertures. In this paper, we use blast waves to characterize the energy emerging through a 2.4 mm aperture and show experimental results in comparison to simulations. PMID:19044574

  9. Distinguishing Realistic Military Blasts from Firecrackers in Mitigation Studies of Blast Induced Traumatic Brain Injury

    SciTech Connect

    Moss, W C; King, M J; Blackman, E G

    2011-01-21

    that the headform locally experiences a nearly planar blast wave. Also, the positive phase durations and blast impulses are much larger than those of (1). Consequently, the blast model used in (1) is spatially and temporally very different from a military blast. It would be useful to repeat the calculations using military blast parameters. Finally, (1) overlooks a significant part of (5). On page 1 and on page 3, (1) states that (5) did not consider helmet pads. But pages pages 3 and 4 of (5) present simulations of blast wave propagation across an ACH helmeted head form with and without pads. (5) states that when the pads are present, the 'underwash' of air under the helmet is blocked when compared to the case without. (1) reaches this same conclusion, but reports it as a new result rather than a confirmation of that already found in (5).

  10. Histologic, immunohistochemical, and ultrastructural findings in human blast lung injury.

    PubMed

    Tsokos, Michael; Paulsen, Friedrich; Petri, Susan; Madea, Burkhard; Puschel, Klaus; Turk, Elisabeth E

    2003-09-01

    The objective of this autopsy-based study was to investigate the pathology of human blast lung injury using histology, Fat Red 7B staining, immunohistochemistry, and scanning electron microscopy on lung specimens from eight medicolegal autopsy cases of fatal close-range detonations of chemical explosives. The micromorphologic equivalents of human blast lung injury can be summarized as follows: diffuse alveolar overdistension, circumscribed interstitial hemorrhages showing a cufflike pattern around pulmonary vessels, venous air embolism, bone marrow embolism, and pulmonary fat embolism. Hemorrhages within the lung parenchyma that were present in this study in blast victims without coexisting blunt or penetrating chest trauma must be regarded as potentially life-threatening intrapulmonary bleeding sites in survivors. In addition, the potential clinical importance of the presence of massive pulmonary fat embolism, which has, to the best of our knowledge, not been described previously in human blast lung injury, must be emphasized because pulmonary fat embolism may be a leading cause of the rapid respiratory deterioration with progressive hypoxia and development of acute respiratory distress syndrome in blast victims who survive. Furthermore, this study provides evidence that air embolism presenting in blast victims is not a mere ventilation-induced artifact.

  11. Fragmentation, Cost and Environmental Effects of Plaster Stemming Method for Blasting at A Basalt Quarry

    NASA Astrophysics Data System (ADS)

    Cevizci, Halim

    2014-10-01

    In this study, the plaster stemming application for blasting at a basalt quarry is studied. Drill cuttings are generally used in open pits and quarries as the most common stemming material since these are most readily available at blast sites. However, dry drill cuttings eject very easily from blastholes without offering much resistance to blast energy. The plaster stemming method has been found to be better than the drill cuttings stemming method due to increased confinement inside the hole and better utilization of blast explosive energy in the rock. The main advantage of the new stemming method is the reduction in the cost of blasting. At a basalt quarry, blasting costs per unit volume of rock were reduced to 15% by increasing burden and spacing distances. In addition, better fragmentation was obtained by using the plaster stemming method. Blast trials showed that plaster stemming produced finer material. In the same blast tests, +30 cm size fragments were reduced to 47.3% of the total, compared to 32.6% in the conventional method of drill cuttings stemming. With this method of stemming, vibration and air shock values increased slightly due to more blast energy being available for rock breakage but generally these increased values were small and stayed under the permitted limit for blast damage criteria unless measuring distance is too close.

  12. Blast Load Response of Steel Sandwich Panels with Liquid Encasement

    SciTech Connect

    Dale Karr; Marc Perlin; Benjamin Langhorst; Henry Chu

    2009-10-01

    We describe an experimental investigation of the response of hybrid blast panels for protection from explosive and impact forces. The fundamental notion is to dissipate, absorb, and redirect energy through plastic collapse, viscous dissipation, and inter-particle forces of liquid placed in sub-structural compartments. The panels are designed to absorb energy from an impact or air blast by elastic-plastic collapse of the panel substructure that includes fluid-filled cavities. The fluid contributes to blast effects mitigation by providing increased initial mass and resistance, by dissipation of energy through viscosity and fluid flow, and by redirecting the momentum that is imparted to the system from the impact and blast impulse pressures. Failure and deformation mechanisms of the panels are described.

  13. (Discussion of plastic media blasting): Foreign trip report, 1988

    SciTech Connect

    Gat, U.

    1988-07-21

    The visit to MBB was to see and discuss the plastic media blasting equipment developed and manufactured as a cooperative effort by Schlick and MBB. The Germans emphasized a systematic approach and complete control over most parameters. The goal is to achieve conditions which do not cause damage to the aircraft. To arrive at the goal the air pressure that delivers the air to entrain the media, the flow rate of media, and the media itself are carefully and accurately controlled. Distance of nozzle and angle of blasting were systematically investigated. The wet (freon) cleanup system under development at Schlick was not discussed.

  14. Increased levels of oxidative DNA damage in pesticide sprayers in Thessaly Region (Greece). Implications of pesticide exposure.

    PubMed

    Koureas, Michalis; Tsezou, Aspasia; Tsakalof, Andreas; Orfanidou, Timoklia; Hadjichristodoulou, Christos

    2014-10-15

    The widespread use of pesticides substances nowadays largely guarantees the protection of crops and people from undesired pests. However, exposure to pesticides was related to a variety of human health effects. The present study was conducted in the region of Thessaly which is characterized by intensive agricultural activities and wide use of pesticides. The study aimed at estimating the oxidative damage to DNA in different subpopulations in Thessaly region (Greece) and investigating its correlation with exposure to pesticides and other potential risk factors. In total, the study involved 80 pesticide sprayers, 85 rural residents and 121 individuals, inhabitants of the city of Larissa. Demographic characteristics, habits, medical history and exposure history of the participants to pesticides were recorded by personal interviews. Blood and urine samples were collected from all participants. For the measurement of exposure to organophosphorus insecticides, dialkylphosphate (DAP) metabolites were quantified in urine, by gas chromatography-mass spectrometry. Genomic DNA was extracted from peripheral blood samples and the oxidation by-product 8-hydroxydeoxyguanosine (8-OHdG) was determined by Enzyme Immuno-Assay. Urinary metabolite concentrations were not associated with 8-OHdG levels but it was found that pesticide sprayers had significantly higher levels of 8-OHdG (p=0.007) in comparison to the control group. Last season's exposure to insecticides and fungicides, expressed as total area treated multiplied by the number of applications, showed a statistically significant association with the risk of having high 8-OHdG levels [RR: 2.19 (95%CI:1.09-4.38) and RR: 2.32 (95% CI:1.16-4.64) respectively]. Additionally, from the subgroups of pesticides examined, seasonal exposure to neonicotinoid insecticides [RR: 2.22 (95% CI:1.07-4.63)] and glufosinate ammonium [RR: 3.26 (95% CI:1.38-7.69)] was found to have the greater impact on 8-OHdG levels. This study produced findings

  15. Passive blast pressure sensor

    DOEpatents

    King, Michael J.; Sanchez, Roberto J.; Moss, William C.

    2013-03-19

    A passive blast pressure sensor for detecting blast overpressures of at least a predetermined minimum threshold pressure. The blast pressure sensor includes a piston-cylinder arrangement with one end of the piston having a detection surface exposed to a blast event monitored medium through one end of the cylinder and the other end of the piston having a striker surface positioned to impact a contact stress sensitive film that is positioned against a strike surface of a rigid body, such as a backing plate. The contact stress sensitive film is of a type which changes color in response to at least a predetermined minimum contact stress which is defined as a product of the predetermined minimum threshold pressure and an amplification factor of the piston. In this manner, a color change in the film arising from impact of the piston accelerated by a blast event provides visual indication that a blast overpressure encountered from the blast event was not less than the predetermined minimum threshold pressure.

  16. Blast94: Bromine latitudinal air/sea transect 1994. Report on oceanic measurements of methyl bromide and other compounds. Technical memo

    SciTech Connect

    Lobert, J.M.; Butler, J.H.; Geller, L.S.; Yvon, S.A.; Montzka, S.A.

    1996-02-01

    Methyl bromide (CH3Br) is of particular interest because it is both produced and consumed in the ocean, thus allowing the ocean to act as a buffer for CH3Br in the atmosphere. The main objective of the two NOAA/CMDL Bromine Latitudinal Air/Sea Transect Expeditions has been to resolve the discrepancy in previously reported data for oceanic CH3Br, and to extend the understanding of the distribution and cycling of CH3Br between the atmosphere and ocean. This was pursued by making frequent, shipboard measurements of CH3Br in the surface water and the marine atmosphere along the cruise tracks and by obtaining depth profiles of CH3Br at selected stations. Secondary objectives included obtaining atmospheric and surface water data for other methyl halides, most notably CH3Cl, CH3I, CH2Br2, and CHBr3.

  17. Carbon monoxide exposure in blast furnace workers.

    PubMed

    Lewis, S; Mason, C; Srna, J

    1992-09-01

    This study investigated the occupational exposure to carbon monoxide (CO) of a group of blast furnace workers from an integrated steelworks, compared to a control group having no significant occupational CO exposure from other areas in the same works. The study was undertaken in 1984 at Port Kembla, New South Wales. Carboxyhaemoglobin (COHb) levels before and after an eight-hour work shift were measured in 98 male steelworkers: 52 from two CO-exposed iron blast furnaces and 46 controls from production areas in the same steelworks. The sample was stratified by smoking habits. Environmental air CO levels had been found to be consistently higher on one furnace than on the other. Absorption of CO from the working environment occurred in workers on the blast furnace with higher CO levels, regardless of smoking habits. On this blast furnace, some readings of COHb levels after a workshift in nonsmokers approached the proposed Australian occupational limit of 5 per cent COHb saturation. Overall, workers with the highest occupational exposure who smoked most heavily had the highest absorption of CO over a work shift. Biological monitoring gives an accurate measure of individual worker 'dose' of CO from all sources. Both environmental monitoring and biological monitoring need to be included as part of a program for controlling occupational CO exposure. PMID:1482718

  18. Carbon monoxide exposure in blast furnace workers.

    PubMed

    Lewis, S; Mason, C; Srna, J

    1992-09-01

    This study investigated the occupational exposure to carbon monoxide (CO) of a group of blast furnace workers from an integrated steelworks, compared to a control group having no significant occupational CO exposure from other areas in the same works. The study was undertaken in 1984 at Port Kembla, New South Wales. Carboxyhaemoglobin (COHb) levels before and after an eight-hour work shift were measured in 98 male steelworkers: 52 from two CO-exposed iron blast furnaces and 46 controls from production areas in the same steelworks. The sample was stratified by smoking habits. Environmental air CO levels had been found to be consistently higher on one furnace than on the other. Absorption of CO from the working environment occurred in workers on the blast furnace with higher CO levels, regardless of smoking habits. On this blast furnace, some readings of COHb levels after a workshift in nonsmokers approached the proposed Australian occupational limit of 5 per cent COHb saturation. Overall, workers with the highest occupational exposure who smoked most heavily had the highest absorption of CO over a work shift. Biological monitoring gives an accurate measure of individual worker 'dose' of CO from all sources. Both environmental monitoring and biological monitoring need to be included as part of a program for controlling occupational CO exposure.

  19. Blast wave mitigation by dry aqueous foams

    NASA Astrophysics Data System (ADS)

    Del Prete, E.; Chinnayya, A.; Domergue, L.; Hadjadj, A.; Haas, J.-F.

    2013-02-01

    This paper presents results of experiments and numerical modeling on the mitigation of blast waves using dry aqueous foams. The multiphase formalism is used to model the dry aqueous foam as a dense non-equilibrium two-phase medium as well as its interaction with the high explosion detonation products. New experiments have been performed to study the mass scaling effects. The experimental as well as the numerical results, which are in good agreement, show that more than an order of magnitude reduction in the peak overpressure ratio can be achieved. The positive impulse reduction is less marked than the overpressures. The Hopkinson scaling is also found to hold particularly at larger scales for these two blast parameters. Furthermore, momentum and heat transfers, which have the main dominant role in the mitigation process, are shown to modify significantly the classical blast wave profile and thereafter to disperse the energy from the peak overpressure due to the induced relaxation zone. In addition, the velocity of the fireball, which acts as a piston on its environment, is smaller than in air. Moreover, the greater inertia of the liquid phase tends to project the aqueous foam far from the fireball. The created gap tempers the amplitude of the transmitted shock wave to the aqueous foam. As a consequence, this results in a lowering of blast wave parameters of the two-phase spherical decaying shock wave.

  20. Evaluation of five additional enhancements to the building loads analysis and system thermodynamics (BLAST) program. Final report

    SciTech Connect

    Nemeth, R.J.

    1993-04-01

    The Building Loads Analysis and System Thermodynamics (BLAST) energy analysis computer program has undergone a multiyear enhancement program based on feedback and priorities of the BLAST users' group. This project was conducted to evaluate the convenience and applicability of the following BLAST enhancements: Air-to-Air Heat Pump; Expanded Baseboard Heat Options; Report Writer; Thermal Comfort Model. Ice Storage Model; Evaluation responses indicate that the enhancements satisfied users' needs for advanced building energy analysis tools. Although the evaluations revealed program bugs and the lack of documentation in some areas, the programs were easy to install and use. The bugs have been removed and the documentation expanded in the BLAST Users Reference. It is recommended that the enhancements be distributed with future updates and releases of the BLAST program.... BLAST, Enhancements, Energy efficient, Comfort analysis, Technology Transfer Test Bed(T3B).

  1. MEASUREMENTS OF VOLATILE ORGANIC COMPOUNDS AND PARTICLES DURING APPLICATION OF LATEX PAINT WITH AN AIRLESS SPRAYER

    EPA Science Inventory

    The paper discusses experiments, conducted at EPA's Indoor Air Quality Research House, to measure airborne concentrations of volatile organic compounds (VOCs) and particles during and following the spray-application of latex wall paint. (NOTE: Paint may be applied indoors by a v...

  2. Determination of phosphorus and sulfur in fuel rich air-hydrogen flames.

    PubMed

    Syty, A; Dean, J A

    1968-07-01

    Excitation conditions for the green HPO bands, the uv PO bands, and the violet S(2) bands were explored. A cylindrical glass shield placed around the tip of a Beckman (sprayer) burner provided a simple arrangement to isolate a fuel rich environment of a reversed air-hydrogen flame. Samples were converted to aerosol in a separate nebulization chamber. The HPO band at 5262 A gave a detection limit of 6 microg/ml; the S(2) band, 5 microg/ml. Owing to low flame noise, both detection limits could be improved with interference filters in place of the Beckman small quartz monochromator. The PO bands are emitted best from fuel rich oxygen-acetylene flames with the normal Beckman sprayer burner. The significant aspect of this study lies in the introduction of liquid samples and circumvention of lengthy, and often uncertain, decomposition steps when handling many types of organic and biochemical compounds containing phosphorus and sulfur.

  3. Determination of phosphorus and sulfur in fuel rich air-hydrogen flames.

    PubMed

    Syty, A; Dean, J A

    1968-07-01

    Excitation conditions for the green HPO bands, the uv PO bands, and the violet S(2) bands were explored. A cylindrical glass shield placed around the tip of a Beckman (sprayer) burner provided a simple arrangement to isolate a fuel rich environment of a reversed air-hydrogen flame. Samples were converted to aerosol in a separate nebulization chamber. The HPO band at 5262 A gave a detection limit of 6 microg/ml; the S(2) band, 5 microg/ml. Owing to low flame noise, both detection limits could be improved with interference filters in place of the Beckman small quartz monochromator. The PO bands are emitted best from fuel rich oxygen-acetylene flames with the normal Beckman sprayer burner. The significant aspect of this study lies in the introduction of liquid samples and circumvention of lengthy, and often uncertain, decomposition steps when handling many types of organic and biochemical compounds containing phosphorus and sulfur. PMID:20068796

  4. Development and Evaluation of a Combined Cultivator and Band Sprayer with a Row-Centering RTK-GPS Guidance System

    PubMed Central

    Perez-Ruiz, Manuel; Carballido, Jacob; Agüera, Juan; Rodríguez-Lizana, Antonio

    2013-01-01

    Typically, low-pressure sprayers are used to uniformly apply pre- and post-emergent herbicides to control weeds in crop rows. An innovative machine for weed control in inter-row and intra-row areas, with a unique combination of inter-row cultivation tooling and intra-row band spraying for six rows and an electro-hydraulic side-shift frame controlled by a GPS system, was developed and evaluated. Two weed management strategies were tested in the field trials: broadcast spraying (the conventional method) and band spraying with mechanical weed control using RTK-GPS (the experimental method). This approach enabled the comparison between treatments from the perspective of cost savings and efficacy in weed control for a sugar beet crop. During the 2010–2011 season, the herbicide application rate (112 L ha−1) of the experimental method was approximately 50% of the conventional method, and thus a significant reduction in the operating costs of weed management was achieved. A comparison of the 0.2-trimmed means of weed population post-treatment showed that the treatments achieved similar weed control rates at each weed survey date. Sugar beet yields were similar with both methods (p = 0.92). The use of the experimental equipment is cost-effective on ≥20 ha of crops. These initial results show good potential for reducing herbicide application in the Spanish beet industry. PMID:23478600

  5. Evaluation of a sheathless nanospray interface based on a porous tip sprayer for CE-ESI-MS coupling.

    PubMed

    Bonvin, Grégoire; Veuthey, Jean-Luc; Rudaz, Serge; Schappler, Julie

    2012-02-01

    The hyphenation of capillary electrophoresis (CE) with mass spectrometry (MS) is a powerful method to obtain high efficient, sensitive, and selective analyses. The successful coupling with electrospray ionization (ESI) source requires closed electric circuits for both the CE separation and the ESI processes. A wide range of interfaces has been proposed to satisfy this requirement. Among them, the new high sensitivity porous sprayer based on a porous tip achieves the electric connection by inserting the capillary outlet made of a porous material into an ESI needle filled with a conductive liquid and independently grounded. This device is compatible with the minute flow rates exhibited in CE and therefore makes possible the use of a nano-electrospray behavior. In this work, this interface was evaluated for hyphenating a CE with a single quadrupole MS instrument for low molecular weight analytes. Investigations aimed at highlighting the most influent parameters thanks to a design of experiments, reaching the best performance in terms of sensitivity and stability. MS signal intensities of various pharmaceutical compounds (e.g. amphetamines, β-blockers) emphasized high sensitivity and efficiency, while repeatability, expressed as relative standard deviation of corrected heights and areas, was suitable for quantitative purposes (<5%).

  6. Hybrid S2/Carbon Epoxy Composite Armours Under Blast Loads

    NASA Astrophysics Data System (ADS)

    Dolce, F.; Meo, Michele; Wright, A.; French, M.; Bernabei, M.

    2012-06-01

    Civil and military structures, such as helicopters, aircrafts, naval ships, tanks or buildings are susceptible to blast loads as terroristic attacks increases, therefore there is the need to design blast resistant structures. During an explosion the peak pressure produced by shock wave is much greater than the static collapse pressure. Metallic structures usually undergo large plastic deformations absorbing blast energy before reaching equilibrium. Due to their high specific properties, fibre-reinforced polymers are being considered for energy absorption applications in blast resistant armours. A deep insight into the relationship between explosion loads, composite architecture and deformation/fracture behaviour will offer the possibility to design structures with significantly enhanced energy absorption and blast resistance performance. This study presents the results of a numerical investigation aimed at understanding the performance of a hybrid composite (glass/carbon fibre) plate subjected to blast loads using commercial LS-DYNA software. In particular, the paper deals with numerical 3D simulations of damages caused by air blast waves generated by C4 charges on two fully clamped rectangular plates made of steel and hybrid (S2/Carbon) composite, respectively. A Multi Materials Arbitrary Lagrangian Eulerian (MMALE) formulation was used to simulate the shock phenomenon. For the steel plates, the Johnson-Cook material model was employed. For the composite plates both in-plane and out-of-plane failure criteria were employed. In particular, a contact tiebreak formulation with a mixed mode failure criteria was employed to simulate delamination failure. As for the steel plates the results showed that excellent correlation with the experimental data for the two blast load conditions in terms of dynamic and residual deflection for two different C4 charges. For the composite plates the numerical results showed that, as expected, a wider delamination damage was observed

  7. PhyloBLAST: facilitating phylogenetic analysis of BLAST results.

    PubMed

    Brinkman, F S; Wan, I; Hancock, R E; Rose, A M; Jones, S J

    2001-04-01

    PhyloBLAST is an internet-accessed application based on CGI/Perl programming that compares a users protein sequence to a SwissProt/TREMBL database using BLAST2 and then allows phylogenetic analyses to be performed on selected sequences from the BLAST output. Flexible features such as ability to input your own multiple sequence alignment and use PHYLIP program options provide additional web-based phylogenetic analysis functionality beyond the analysis of a BLAST result.

  8. Explosive blast neurotrauma.

    PubMed

    Ling, Geoffrey; Bandak, Faris; Armonda, Rocco; Grant, Gerald; Ecklund, James

    2009-06-01

    Explosive blast traumatic brain injury (TBI) is one of the more serious wounds suffered by United States service members injured in the current conflicts in Iraq and Afghanistan. Some military medical treatments for blast TBI that have been introduced successfully in the war theater include decompressive craniectomy, cerebral angiography, transcranial Doppler, hypertonic resuscitation fluids, among others. Stateside neurosurgery, neuro-critical care, and rehabilitation for these patients have similarly progressed. With experience, military physicians have been able to clinically describe blast TBI across the entire severity spectrum. One important clinical finding is that a significant number of severe blast TBI victims develop pseudoaneurysms and vasospasm, which can lead to delayed decompensation. Another is that mild blast TBI shares clinical features with post-traumatic stress disorder (PTSD). Observations suggest that the mechanism by which explosive blast injures the central nervous system may be more complex than initially assumed. Rigorous study at the basic science and clinical levels, including detailed biomechanical analysis, is needed to improve understanding of this disease. A comprehensive epidemiological study is also warranted to determine the prevalence of this disease and the factors that contribute most to the risk of developing it. Sadly, this military-specific disease has significant potential to become a civilian one as well.

  9. Curved characteristics behind blast waves.

    NASA Technical Reports Server (NTRS)

    Laporte, O.; Chang, T. S.

    1972-01-01

    The behavior of nonisentropic flow behind a propagating blast wave is theoretically studied. Exact solutions, expressed in closed form in terms of elementary functions, are presented for three sets of curved characteristicseind a self-similar, strong blast wave.

  10. Blast Wave Exposure Impairs Memory and Decreases Axon Initial Segment Length

    PubMed Central

    Baalman, Kelli L.; Cotton, R. James; Rasband, S. Neil

    2013-01-01

    Abstract Exposure to a blast wave has been proposed to cause mild traumatic brain injury (mTBI), with symptoms including altered cognition, memory, and behavior. This idea, however, remains controversial, and the mechanisms of blast-induced brain injury remain unknown. To begin to resolve these questions, we constructed a simple compressed air shock tube, placed rats inside the tube, and exposed them to a highly reproducible and controlled blast wave. Consistent with the generation of a mild injury, 2 weeks after exposure to the blast, we found that motor performance was unaffected, and a panel of common injury markers showed little or no significant changes in expression in the cortex, corpus callosum, or hippocampus. Similarly, we were unable to detect elevated spectrin breakdown products in brains collected from blast-exposed rats. Using an object recognition task, however, we found that rats exposed to a blast wave spent significantly less time exploring a novel object when compared with control rats. Intriguingly, we also observed a significant shortening of the axon initial segment (AIS) in both the cortex and hippocampus of blast-exposed rats, suggesting altered neuronal excitability after exposure to a blast. A computational model showed that shortening the AIS increased both threshold and the interspike interval of repetitively firing neurons. These results support the conclusion that exposure to a single blast wave can lead to mTBI with accompanying cognitive impairment and subcellular changes in the molecular organization of neurons. PMID:23025758

  11. Role of hydrogen in blast furnaces to improve productivity and decrease coke consumption

    SciTech Connect

    Agarwal, J.C.; Brown, F.C.; Chin, D.L.; Stevens, G.; Clark, R.; Smith, D.

    1995-12-01

    The hydrogen contained in blast furnace gases exerts a variety of physical, thermochemical, and kinetic effects as the gases pass through the various zones. The hydrogen is derived from two sources: (1) the dissociation of moisture in the blast air (ambient and injected with hot blast), and (2) the release from partial combustion of supplemental fuels (including moisture in atomizing water, steam, or transport air, if any). With each atom of oxygen (or carbon), the molar amounts of hydrogen released are more than six times higher for natural gas than for coal, and two times higher for natural gas than for oil. Injection of natural gas in a blast furnace is not a new process. Small amounts of natural gas--about 50--80 lb or 1,100--1,700 SCF/ton of hot metal--have been injected in many of the North American blast furnaces since the early 1960s, with excellent operating results. What is new, however, is a batter understanding of how natural gas reacts in the blast furnace and how natural gas and appropriate quantities of oxygen can be used to increase the driving rate or combustion rate of carbon (coke) in the blast furnace without causing hanging furnace and operating problems. The paper discusses the factors limiting blast furnace productivity and how H{sub 2} and O{sub 2} can increase productivity.

  12. 30 CFR 56.6603 - Air gap.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Air gap. 56.6603 Section 56.6603 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND... § 56.6603 Air gap. At least a 15-foot air gap shall be provided between the blasting circuit and...

  13. 30 CFR 56.6603 - Air gap.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Air gap. 56.6603 Section 56.6603 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND... § 56.6603 Air gap. At least a 15-foot air gap shall be provided between the blasting circuit and...

  14. Explosively-Driven Blast Waves in Small-Diameter Tubes

    NASA Astrophysics Data System (ADS)

    Cooper, M. A.; Marinis, R. T.; Oliver, M. S.

    Studies on blast waves are motivated by the need to understand dynamic pressure loadings in accident scenarios associated with rapid energy release in confined geometries. Explosions from fuel-air mixtures, explosives and industrial accidents often occur within a range of length scales associated with ducts, pipes, corridors, and tunnels [1, 2].

  15. Mechanisms and pathophysiology of the low-level blast brain injury in animal models.

    PubMed

    Säljö, Annette; Mayorga, Maria; Bolouri, Hayde; Svensson, Berndt; Hamberger, Anders

    2011-01-01

    The symptoms of primary blast-induced mTBI, posttraumatic stress disorder and depression overlap. Evidence of an organic basis for these entities has been scarce and controversial. We present a review of animal studies demonstrating that low-level blast causes pathophysiological and functional changes in the brain. We monitor a time period from minutes to approximately 1 week after blast exposure from multiple modes (air, underwater, localized and whole body). The most salient findings observed were (1) the peak pressures (P(max)) in the brain, elicited from the blast from the firing of military weapons (P(max) 23-45 kPa), have a similar magnitude as that registered in air close to the head. Corresponding measurements during the detonation pulse from explosives under water show a P(max) in the brain, which is only 10% of that in water outside the head. (2) The rise time of the pressure curve is 10 times longer in the brain as compared with the blast in air outside the head during firing of military weapons. (3) The lower frequencies in the blast wave appear to be transmitted more readily to the brain than the higher frequencies. (4) When animals are exposed to low levels of blast, the blast wave appears mostly transmitted directly to the brain during air exposure, not via the thorax or abdomen. (5) Low levels of blast cause brain edema, as indicated by increased bioelectrical impedance, an increase in the intracranial pressure, small brain hemorrhages and impaired cognitive function. PMID:20580846

  16. Primary blast injury: pathophysiology and implications for treatment. Part III: Injury to the central nervous system and the limbs.

    PubMed

    Guy, R J; Glover, M A; Cripps, N P

    2000-01-01

    There are some structures in which changes consistent with primary blast may be found despite secondary and tertiary blast being the most frequent sources of injury. The Central Nervous System for example, especially the brain, is well protected yet there are historical and experimental accounts of damage which cannot be attributed to secondary or tertiary blast or even air embolism resulting from pulmonary disruption. Similarly, analysis and experimental simulation of specific skeletal injuries has shown that primary blast alone can fracture bones and that it is likely to be responsible for limb avulsions in victims exposed to stress waves of sufficiently high intensity. PMID:10892035

  17. 25. "GAFFTC 19 OCT 60, BLAST EFFECTS ON AIRFOILS, STATIC ...

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

    25. "G-AFFTC 19 OCT 60, BLAST EFFECTS ON AIRFOILS, STATIC RUN 5." View of track rail mounting and the water brake trough at 20,000-foot track. Looking northeast. File no. 12,358-60. - Edwards Air Force Base, South Base Sled Track, Edwards Air Force Base, North of Avenue B, between 100th & 140th Streets East, Lancaster, Los Angeles County, CA

  18. Cold blast furnace syndrome: a new source of toxic inhalation by nitrogen oxides

    PubMed Central

    Tague, I; Llewellin, P; Burton, K; Buchan, R; Yates, D

    2004-01-01

    Methods: Fourteen workers developed acute respiratory symptoms shortly after exposure to "air blast" from blast furnace tuyeres. These included chest tightness, dyspnoea, rigors, and diaphoresis. Chest radiographs showed pulmonary infiltrates, and lung function a restrictive abnormality. This report includes a description of clinical features of the affected workers and elucidation of the probable cause of the outbreak. Results: Clinical features and occupational hygiene measurements suggested the most likely cause was inhalation of nitrogen oxides at high pressure and temperature. While the task could not be eliminated, engineering controls were implemented to control the hazard. No further cases have occurred. Conclusions: "Cold blast furnace syndrome" represents a previously undescribed hazard of blast furnace work, probably due to inhalation of nitrogen oxides. It should be considered in the differential diagnosis of acute toxic inhalational injuries in blast furnace workers. PMID:15090669

  19. Remote operated vehicle with carbon dioxide blasting (ROVCO{sub 2})

    SciTech Connect

    Resnick, A.M.

    1995-10-01

    The Remote Operated Vehicle with Carbon Dioxide Blasting (ROVCO{sub 2}), as shown in a front view is a six-wheeled remote land vehicle used to decontaminate concrete floors. The remote vehicle has a high pressure Cryogenesis blasting subsystem, Oceaneering Technologies (OTECH) developed a CO{sub 2} xY Orthogonal Translational End Effector (COYOTEE) subsystem, and a vacuum/filtration and containment subsystem. The cryogenesis subsystem performs the actual decontamination work and consists of the dry ice supply unit, the blasting nozzle, the remotely controlled electric and pneumatic valves, and the vacuum work-head. The COYOTEE subsystem positions the blasting work-head within a planar work space and the vacuum subsystem provides filtration and containment of the debris generated by the CO{sub 2} blasting. It employs a High Efficiency Particulate Air (HEPA) filtration unit to separate contaminants for disposal. All of the above systems are attached to the vehicle subsystem via the support structure.

  20. Emulsified blasting agents

    SciTech Connect

    Chironis, N.P.

    1985-01-01

    This article describes an improved blasting agent which is being tailor-blended with bulk ANFO to provide more explosive energy and better water resistance when the blasting conditions call for it. The proportions of the emulsion/ANFO mix are easily changed at the blasthole site because both materials can be selectively mixed in modified bulk-explosive trucks before loading the blasting agents into the holes. Such blends are helping speed stripping at a number of surface mines and are leading to cost savings in production, ranging from 10% to 30%, depending upon application, even though the actual cost of a blend will be higher than if bulk ANFO is used alone.

  1. Cylindrically converging blast waves in air

    NASA Astrophysics Data System (ADS)

    Matsuo, H.; Nakamura, Y.

    1981-07-01

    Cylindrically converging shock waves are produced by utilizing the detonation of cylindrical explosive shells. The production and the propagation of shock waves are observed by framing and streak camera photographs, and the trajectory of shock propagations is determined by using an electrical ionization probing system. The effect of the quantity of explosives on the stability, or the axial symmetry, of shock fronts and on the strength of shocks produced is investigated. It has been shown that, for practical purposes, the approximation of shock trajectories by Guderley's formulas would be sufficiently acceptable in an unexpectedly wide region near the implosion center, and that the axial symmetry of the shock front is improved by increasing the quantity of explosives, and thus, strong shocks are produced by merely increasing the quantity of explosives. The reflected diverging shock seems to be very stable. Piezoelectric elements have also been used to detect reflected diverging waves.

  2. Visual system degeneration induced by blast overpressure.

    PubMed

    Petras, J M; Bauman, R A; Elsayed, N M

    1997-07-25

    The effect of blast overpressure on visual system pathology was studied in 14 male Sprague-Dawley rats weighing 360-432 g. Blast overpressure was simulated using a compressed-air driven shock tube, with the aim of studying a range of overpressures causing sublethal injury. Neither control (unexposed) rats nor rats exposed to 83 kiloPascals (kPa) overpressure showed evidence of visual system pathology. Neurological injury to brain visual pathways was observed in male rats surviving blast overpressure exposures of 104-110 kPa and 129-173 kPa. Optic nerve fiber degeneration was ipsilateral to the blast pressure wave. The optic chiasm contained small numbers of degenerated fibers. Optic tract fiber degeneration was present bilaterally, but was predominantly ipsilateral. Optic tract fiber degeneration was followed to nuclear groups at the level of the midbrain, midbrain-diencephalic junction, and the thalamus where degenerated fibers arborized among the neurons of: (i) the superior colliculus, (ii) pretectal region, and (iii) the lateral geniculate body. The superior colliculus contained fiber degeneration localized principally to two superficial layers (i) the stratum opticum (layer III) and (ii) stratum cinereum (layer II). The pretectal area contained degenerated fibers which were widespread in (i) the nucleus of the optic tract, (ii) olivary pretectal nucleus, (iii) anterior pretectal nucleus, and (iv) the posterior pretectal nucleus. Degenerated fibers in the lateral geniculate body were not universally distributed. They appeared to arborize among neurons of the dorsal and ventral nuclei: the ventral lateral geniculate nucleus (parvocellular and magnocellular parts); and the dorsal lateral geniculate nucleus. The axonopathy observed in the central visual pathways and nuclei of the rat brain are consistent with the presence of blast overpressure induced injury to the retina. The orbital cavities of the human skull contain frontally-directed eyeballs for binocular

  3. Application of ground vibration frequency spectrum analysis as a tool for optimizing the blast design in large open pit mines

    SciTech Connect

    Rao, K.R.

    1994-12-31

    This paper explains the methodology for assessing the efficiency of rockmass fragmentation by explosive blasting, from ground vibration frequency spectrum analysis of the blast event. Explosives are used in the mining, quarrying and construction industries for fragmenting rockmass to a suitable size. When an explosive charge is detonated, in addition to fragmenting the rockmass, it will also generate ground vibration and air vibrations. Efficiency of a blast depend upon percentage of blast energy wasted in generating ground vibrations and air vibrations. This in turn will depend upon rockmass characteristics, amount of explosive energy used per delay and spatial distribution of explosive in the rockmass. Ground vibrations and air vibrations, arising out of explosive detonation in a rockmass, could be captured by micro-computer based engineering seismograph and sound level meter. Typical frequency range indicative of efficient rockmass fragmentation for a particular rockmass can be identified from ground vibration frequency spectra analysis of the blast event on a personal computer applying Fast Fourier transforms (FFT). The typical frequency range indicative of efficient rockmass fragmentation depends upon rockmass impedance and can be estimated from rockmass characteristics and monitoring few trial blasts. Blast event efficiency is estimated by comparing the typical frequency range with the dominant frequency range of the blast event record. A large number of blast events monitored and analyzed by the author in different rockmass formations and correlation of the results with observations made while fragmented material is lifted and loaded into trucks indicated that ground vibration frequency spectrum analysis could be used as a reliable and cost effective tool for assessing the blasting efficiency and optimizing blast design in large open-pit mines.

  4. Blast-induced color change in photonic crystals corresponds with brain pathology.

    PubMed

    Cullen, D Kacy; Browne, Kevin D; Xu, Yongan; Adeeb, Saleena; Wolf, John A; McCarron, Richard M; Yang, Shu; Chavko, Mikulas; Smith, Douglas H

    2011-11-01

    A high incidence of blast exposure is a 21st century reality in counter-insurgency warfare. However, thresholds for closed-head blast-induced traumatic brain injury (bTBI) remain unknown. Moreover, without objective information about relative blast exposure, warfighters with bTBI may not receive appropriate medical care and may remain in harm's way. Accordingly, we have engineered a blast injury dosimeter (BID) using a photonic crystalline material that changes color following blast exposure. The photonic crystals are fabricated using SU-8 via multi-beam interference laser lithography. The final BID is similar in appearance to an array of small colored stickers that may be affixed to uniforms or helmets in multiple locations. Although durable under normal conditions, the photonic crystalline micro- and nano-structure are precisely altered by blast to create a color change. These BIDs were evaluated using a rat model of bTBI, for which blast shockwave exposure was generated via a compressed air-driven shock tube. With prototype BID arrays affixed to the animals, we found that BID color changes corresponded with subtle brain pathologies, including neuronal degeneration and reactive astrocytosis. These subtle changes were most notable in the dentate gyrus of the hippocampus, cerebral cortex, and cerebellum. These data demonstrate the feasibility of using a materials-based, power-free colorimetric BID as the first self-contained blast sensor calibrated to correspond with brain pathology.

  5. Blast-Induced Color Change in Photonic Crystals Corresponds with Brain Pathology

    PubMed Central

    Cullen, D. Kacy; Browne, Kevin D.; Xu, Yongan; Adeeb, Saleena; Wolf, John A.; McCarron, Richard M.; Yang, Shu; Chavko, Mikulas

    2011-01-01

    Abstract A high incidence of blast exposure is a 21st century reality in counter-insurgency warfare. However, thresholds for closed-head blast-induced traumatic brain injury (bTBI) remain unknown. Moreover, without objective information about relative blast exposure, warfighters with bTBI may not receive appropriate medical care and may remain in harm's way. Accordingly, we have engineered a blast injury dosimeter (BID) using a photonic crystalline material that changes color following blast exposure. The photonic crystals are fabricated using SU-8 via multi-beam interference laser lithography. The final BID is similar in appearance to an array of small colored stickers that may be affixed to uniforms or helmets in multiple locations. Although durable under normal conditions, the photonic crystalline micro- and nano-structure are precisely altered by blast to create a color change. These BIDs were evaluated using a rat model of bTBI, for which blast shockwave exposure was generated via a compressed air-driven shock tube. With prototype BID arrays affixed to the animals, we found that BID color changes corresponded with subtle brain pathologies, including neuronal degeneration and reactive astrocytosis. These subtle changes were most notable in the dentate gyrus of the hippocampus, cerebral cortex, and cerebellum. These data demonstrate the feasibility of using a materials-based, power-free colorimetric BID as the first self-contained blast sensor calibrated to correspond with brain pathology. PMID:22082449

  6. Examining lethality risk for rodent studies of primary blast lung injury.

    PubMed

    Hubbard, William Brad; Hall, Christina; Siva Sai Suijith Sajja, Venkata; Lavik, Erink; VandeVord, Pamela

    2014-01-01

    While protective measures have been taken to mitigate injury to the thorax during a blast exposure, primary blast lung injury (PBLI) is still evident in mounted/in vehicle cases during military conflicts. Moreover, civilians, who are unprotected from blast exposure, can be severely harmed by terrorist attacks that use improvised explosive devices (IEDs). Since the lungs are the most susceptible organ due to their air-filled nature, PBLI is one of the most serious injuries seen in civilian blast cases. Determining lethality threshold for rodent studies is crucial to guide experimental designs centered on therapies for survival after PBLI or mechanistic understanding of the injury itself. Using an Advanced Blast Simulator, unprotected rats were exposed to a whole body blast to induce PBLI. The one-hour survival rate was assessed to determine operating conditions for a 50% lethality rate. Macroscopic and histological analysis of lung was conducted using hematoxylin and eosin staining. Results demonstrated lethality risk trends based on static blast overpressure (BOP) for rodent models, which may help standardized animal studies and contribute to scaling to the human level. The need for a standardized method of producing PBLI is pressing and establishing standard curves, such as a lethality risk curve for lung blasts, is crucial for this condensing of BOP methods. PMID:25405409

  7. Infectivity, distribution, and persistence of the entomopathogenic nematode Steinernema carpocapsae all strain (Rhabditida: Steinernematidae) applied by sprinklers or boom sprayer to dry-pick cranberries.

    PubMed

    Hayes, A E; Fitzpatrick, S M; Webster, J M

    1999-06-01

    We evaluated infectivity, distribution, and persistence of commercially produced Steinernema carpocapsae (Weiser) All strain applied through solid set sprinkler irrigation or boom sprayer to 2 dry-pick cranberry farms on peat soil in British Columbia in 1993. Most infectivity assays used Galleria mellonella (L.) larvae. When possible, larvae of the target pest, Otiorynchus sulcatas (F.) were used as assay organisms. Nematodes in almost all samples of nematode suspensions diluted from shipping containers, from spray tanks, or collected in cups after passage through application equipment were infective to G. mellonella larvae. When O. sulcatus larvae were used as assay organisms, 93% (n = 14) of assays from the spray tank and 67% (n = 12) of assays after application showed infectivity. In the spring, sprinklers delivered nematodes to only 15 of 20 sample points on the 0.2-ha plot; delivery by the boom sprayer was better but 2 of 20 points on the 0.2-ha plot received approximately twice as many nematodes as the other points. In the fall, nematode delivery by both systems was more even. However, the average number of nematodes per milliliter of sprayed water collected from the 20 samples on each farm after each application did not correspond to the rates of nematodes applied. Persistence of nematodes in the soil was encouraging, but percentage of infectivity was lower than expected. After application in the spring, assays using G. mellonella larvae showed the presence of infective nematodes in soil samples (0-5 and 5-10 cm deep) on each sampling day (0, 3, 7, and 25) after application by boom sprayer, and on days 0, 3, and 7 after application through sprinklers. In the fall, G. mellonella assays showed infective nematodes in soil samples on each sampling day (0, 3, 7, and 25) after application by boom sprayer, and on days 0, 3, 7, 35, 60, 135, and 250 after application through sprinklers. In the spring, when assays lasted 4 d, percentage of infectivity rose to a

  8. Rapid miniature fiber optic pressure sensors for blast wave measurements

    NASA Astrophysics Data System (ADS)

    Zou, Xiaotian; Wu, Nan; Tian, Ye; Niezrecki, Christopher; Chen, Julie; Wang, Xingwei

    2013-02-01

    Traumatic brain injury (TBI) is a serious potential threat to soldiers who are exposed to explosions. Since the pathophysiology of TBI associated with a blast wave is not clearly defined, it is crucial to have a sensing system to accurately quantify the blast wave dynamics. This paper presents an ultra-fast fiber optic pressure sensor based on Fabry-Perot (FP) interferometric principle that is capable of measuring the rapid pressure changes in a blast event. The blast event in the experiment was generated by a starter pistol blank firing at close range, which produced a more realistic wave profile compared to using compressed air driven shock tubes. To the authors' knowledge, it is also the first study to utilize fiber optic pressure sensors to measure the ballistics shock wave of a pistol firing. The results illustrated that the fiber optic pressure sensor has a rise time of 200 ns which demonstrated that the sensor has ability to capture the dynamic pressure transient during a blast event. Moreover, the resonant frequency of the sensor was determined to be 4.11 MHz, which agrees well with the specific designed value.

  9. BLAST: THE REDSHIFT SURVEY

    SciTech Connect

    Eales, Stephen; Dye, Simon; Mauskopf, Philip; Moncelsi, Lorenzo; Pascale, Enzo; Raymond, Gwenifer; Chapin, Edward L.; Halpern, Mark; Marsden, Gaelen; Scott, Douglas; Devlin, Mark J.; Rex, Marie; Semisch, Christopher; Truch, Matthew D. P.; Hughes, David H.; Netterfield, Calvin B.; Viero, Marco P.; Patanchon, Guillaume; Siana, Brian

    2009-12-20

    The Balloon-borne Large Aperture Submillimeter Telescope (BLAST) has recently surveyed approx =8.7 deg{sup 2} centered on Great Observatories Origins Deep Survey-South at 250, 350, and 500 mum. In Dye et al., we presented the catalog of sources detected at 5sigma in at least one band in this field and the probable counterparts to these sources in other wavebands. In this paper, we present the results of a redshift survey in which we succeeded in measuring redshifts for 82 of these counterparts. The spectra show that the BLAST counterparts are mostly star-forming galaxies but not extreme ones when compared to those found in the Sloan Digital Sky Survey. Roughly one quarter of the BLAST counterparts contain an active nucleus. We have used the spectroscopic redshifts to carry out a test of the ability of photometric redshift methods to estimate the redshifts of dusty galaxies, showing that the standard methods work well even when a galaxy contains a large amount of dust. We have also investigated the cases where there are two possible counterparts to the BLAST source, finding that in at least half of these there is evidence that the two galaxies are physically associated, either because they are interacting or because they are in the same large-scale structure. Finally, we have made the first direct measurements of the luminosity function in the three BLAST bands. We find strong evolution out to z = 1, in the sense that there is a large increase in the space density of the most luminous galaxies. We have also investigated the evolution of the dust-mass function, finding similar strong evolution in the space density of the galaxies with the largest dust masses, showing that the luminosity evolution seen in many wavebands is associated with an increase in the reservoir of interstellar matter in galaxies.

  10. Metallurgical Evaluation of Grit Blasted Versus Non-Grit Blasted Iridium Alloy Clad Vent Set Cup Surfaces

    SciTech Connect

    Ulrich, George B; Longmire, Hu Foster

    2010-02-01

    Metallurgical evaluations were conducted to determine what, if any, grain size differences exist between grit blasted and non-grit blasted DOP-26 iridium alloy cup surfaces and if grit blasting imparts sufficient compressive cold work to induce abnormal grain growth during subsequent temperature exposures. Metallographic measurements indicated that grit blasting cold worked the outside cup surface to a depth of approximately 19 {micro}m. Subsequent processing through the air burn-off (635 C/4h) and vacuum outgassing (1250 C/1h) operations was found to uniformly recrystallize the cold worked surface to produce grains with an average diameter of approximately 8.5 {micro}m (American Society for Testing and Materials (ASTM) grain size number 11). Follow-on heat treatments at 1375 C, 1500 C, and 1900 C for durations ranging from 1 min to 70 h yielded uniform grain sizes and no abnormal grain growth from grit blasting. Abnormal grain growth was noted at the 1500 C and 1900 C heat treatments in areas of cold work from excessive clamping during sample preparation.

  11. A Multiscale Approach to Blast Neurotrauma Modeling: Part II: Methodology for Inducing Blast Injury to in vitro Models

    PubMed Central

    Effgen, Gwen B.; Hue, Christopher D.; Vogel, Edward; Panzer, Matthew B.; Meaney, David F.; Bass, Cameron R.; Morrison, Barclay

    2012-01-01

    Due to the prominent role of improvised explosive devices (IEDs) in wounding patterns of U.S. war-fighters in Iraq and Afghanistan, blast injury has risen to a new level of importance and is recognized to be a major cause of injuries to the brain. However, an injury risk-function for microscopic, macroscopic, behavioral, and neurological deficits has yet to be defined. While operational blast injuries can be very complex and thus difficult to analyze, a simplified blast injury model would facilitate studies correlating biological outcomes with blast biomechanics to define tolerance criteria. Blast-induced traumatic brain injury (bTBI) results from the translation of a shock wave in-air, such as that produced by an IED, into a pressure wave within the skull–brain complex. Our blast injury methodology recapitulates this phenomenon in vitro, allowing for control of the injury biomechanics via a compressed-gas shock tube used in conjunction with a custom-designed, fluid-filled receiver that contains the living culture. The receiver converts the air shock wave into a fast-rising pressure transient with minimal reflections, mimicking the intracranial pressure history in blast. We have developed an organotypic hippocampal slice culture model that exhibits cell death when exposed to a 530 ± 17.7-kPa peak overpressure with a 1.026 ± 0.017-ms duration and 190 ± 10.7 kPa-ms impulse in-air. We have also injured a simplified in vitro model of the blood–brain barrier, which exhibits disrupted integrity immediately following exposure to 581 ± 10.0 kPa peak overpressure with a 1.067 ± 0.006-ms duration and 222 ± 6.9 kPa-ms impulse in-air. To better prevent and treat bTBI, both the initiating biomechanics and the ensuing pathobiology must be understood in greater detail. A well-characterized, in vitro model of bTBI, in conjunction with animal models, will be a powerful tool for developing strategies to mitigate the risks of bTBI. PMID

  12. Identification of blast resistance genes for managing rice blast disease

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice blast, caused by the fungal pathogen Magnaporthe oryzae, is one of the most devastating diseases worldwide. In the present study, an international set of monogenic differentials carrying 24 major blast resistance (R) genes (Pia, Pib, Pii, Pik, Pik-h, Pik-m, Pik-p, Pik-s, Pish, Pit, Pita, Pita2,...

  13. 30 CFR 57.6803 - Blasting lines.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Blasting lines. 57.6803 Section 57.6803 Mineral... and Underground § 57.6803 Blasting lines. Permanent blasting lines shall be properly supported. All blasting lines shall be insulated and kept in good repair. General Requirements—Surface and Underground...

  14. 30 CFR 56.6803 - Blasting lines.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Blasting lines. 56.6803 Section 56.6803 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND... Blasting lines. Permanent blasting lines shall be properly supported. All blasting lines shall be...

  15. 29 CFR 1926.912 - Underwater blasting.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... nonsparking metal loading tube when tube is necessary. (d) No blast shall be fired while any vessel under way... within 1,500 feet shall be notified before a blast is fired. (e) No blast shall be fired while any... in progress, signals and arrangements shall be agreed upon to assure that no blast shall be...

  16. 29 CFR 1926.912 - Underwater blasting.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... nonsparking metal loading tube when tube is necessary. (d) No blast shall be fired while any vessel under way... within 1,500 feet shall be notified before a blast is fired. (e) No blast shall be fired while any... in progress, signals and arrangements shall be agreed upon to assure that no blast shall be...

  17. 29 CFR 1926.912 - Underwater blasting.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... nonsparking metal loading tube when tube is necessary. (d) No blast shall be fired while any vessel under way... within 1,500 feet shall be notified before a blast is fired. (e) No blast shall be fired while any... in progress, signals and arrangements shall be agreed upon to assure that no blast shall be...

  18. 29 CFR 1926.912 - Underwater blasting.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... nonsparking metal loading tube when tube is necessary. (d) No blast shall be fired while any vessel under way... within 1,500 feet shall be notified before a blast is fired. (e) No blast shall be fired while any... in progress, signals and arrangements shall be agreed upon to assure that no blast shall be...

  19. 30 CFR 75.1323 - Blasting circuits.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Blasting circuits. 75.1323 Section 75.1323... MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Explosives and Blasting § 75.1323 Blasting circuits. (a) Blasting circuits shall be protected from sources of stray electric current. (b) Detonators made...

  20. 30 CFR 75.1323 - Blasting circuits.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Blasting circuits. 75.1323 Section 75.1323... MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Explosives and Blasting § 75.1323 Blasting circuits. (a) Blasting circuits shall be protected from sources of stray electric current. (b) Detonators made...

  1. 30 CFR 75.1323 - Blasting circuits.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Blasting circuits. 75.1323 Section 75.1323... MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Explosives and Blasting § 75.1323 Blasting circuits. (a) Blasting circuits shall be protected from sources of stray electric current. (b) Detonators made...

  2. 29 CFR 1926.912 - Underwater blasting.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false Underwater blasting. 1926.912 Section 1926.912 Labor... Underwater blasting. (a) A blaster shall conduct all blasting operations, and no shot shall be fired without... explosives aboard vessels used in underwater blasting operations shall be according to provisions...

  3. Performance of blasting caps

    NASA Technical Reports Server (NTRS)

    Bement, Laurence J. (Inventor); Schimmel, Morry L. (Inventor); Perry, Ronnie B. (Inventor)

    1993-01-01

    Common blasting caps are made from an aluminum shell in the form of a tube which is closed at both ends. One end, which is called the output end, terminates in a principal side or face, and contains a detonating agent which communicates with a means for igniting the detonating agent. The improvement of the present invention is a flat, steel foil bonded to the face in a position which is aligned perpendicularly to the longitudinal axis of the tube.

  4. Computer assisted blast design and assessment tools

    SciTech Connect

    Cameron, A.R.; Kleine, T.H.; Forsyth, W.W.

    1995-12-31

    In general the software required by a blast designer includes tools that graphically present blast designs (surface and underground), can analyze a design or predict its result, and can assess blasting results. As computers develop and computer literacy continues to rise the development of and use of such tools will spread. An example of the tools that are becoming available includes: Automatic blast pattern generation and underground ring design; blast design evaluation in terms of explosive distribution and detonation simulation; fragmentation prediction; blast vibration prediction and minimization; blast monitoring for assessment of dynamic performance; vibration measurement, display and signal processing; evaluation of blast results in terms of fragmentation; and risk and reliability based blast assessment. The authors have identified a set of criteria that are essential in choosing appropriate software blasting tools.

  5. Reactive Blast Waves from Composite Charges

    SciTech Connect

    Kuhl, A L; Bell, J B; Beckner, V E

    2009-10-16

    Investigated here is the performance of composite explosives - measured in terms of the blast wave they drive into the surrounding environment. The composite charge configuration studied here was a spherical booster (1/3 charge mass), surrounded by aluminum (Al) powder (2/3 charge mass) at an initial density of {rho}{sub 0} = 0.604 g/cc. The Al powder acts as a fuel but does not detonate - thereby providing an extreme example of a 'non-ideal' explosive (where 2/3 of the charge does not detonate). Detonation of the booster charge creates a blast wave that disperses the Al powder and ignites the ensuing Al-air mixture - thereby forming a two-phase combustion cloud embedded in the explosion. Afterburning of the booster detonation products with air also enhances and promotes the Al-air combustion process. Pressure waves from such reactive blast waves have been measured in bomb calorimeter experiments. Here we describe numerical simulations of those experiments. A Heterogeneous Continuum Model was used to model the dispersion and combustion of the Al particle cloud. It combines the gasdynamic conservation laws for the gas phase with a dilute continuum model for the dispersed phase, as formulated by Nigmatulin. Inter-phase mass, momentum and energy exchange are prescribed by phenomenological models of Khasainov. It incorporates a combustion model based on mass conservation laws for fuel, air and products; source/sink terms are treated in the fast-chemistry limit appropriate for such gasdynamic fields, along with a model for mass transfer from the particle phase to the gas. The model takes into account both the afterburning of the detonation products of the booster with air, and the combustion of the Al particles with air. The model equations were integrated by high-order Godunov schemes for both the gas and particle phases. Adaptive Mesh Refinement (AMR) was used to capture the energy-bearing scales of the turbulent flow on the computational grid, and to track

  6. Blast furnace injection symposium: Proceedings

    SciTech Connect

    1996-12-31

    These proceedings contain 14 papers related to blast furnace injection issues. Topics include coal quality, coal grinding, natural gas injection, stable operation of the blast furnace, oxygen enrichment, coal conveying, and performance at several steel companies. All papers have been processed separately for inclusion on the data base.

  7. HIGH PRODUCTIVITY VACUUM BLASTING SYSTEM

    SciTech Connect

    Dr. M.A. Ebadian

    2000-01-13

    The purpose of the project is to increase the productivity and economics of existing vacuum blasting technology. This technology is used to remove radioactive contamination, PCB's and lead-base paint and provides worker and environmental protection by continuously recycling the blast media and the full containment of the dust generated in the process.

  8. [Blast injuries of the ear].

    PubMed

    Haralampiev, K; Ristić, B

    1991-01-01

    Blast injury of the ear is the actual military medical problem. The ear, due to its anatomo-physiologic characteristics, is more sensitive to effects of blast waves than other organs and systems. The anatomic and functional ear damages, their symptoms, etiology and clinical course are described. The diagnosis and treatment have been pointed out. PMID:1807053

  9. The effect of sample height on spray coverage in mature pecan trees

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pecan scab (caused by Fusicladium effusum) is the most damaging disease of pecan in the southeastern US. Large air-blast sprayers for orchards are used to apply fungicide to control the disease, but little quantitative information exists on the spray coverage achieved in the canopy of these trees. I...

  10. Characterizing explosives and blasting emissions

    SciTech Connect

    Johnson, M.B.; Bacon, D.P.

    1995-12-31

    With the advance of science, rise of public interest in environmental matters, and continuing erosion of air quality, Federal and state regulators are demanding an increasing complex array of data concerning emissions produced by burning and detonating energetic materials. The US Department of Defense, one of the world`s largest consumers of energetic materials, now must characterize combustion products resulting from open burning/open detonation disposal operations. The catch-all phrase ``below detection limits`` no longer satisfies the regulators who now want testing to delve into the ppt level for volatile organic compounds and ppt level for semivolatile organic compounds. Regulators are also expanding their scope of interest and may soon be asking for emissions data on training operations such as artillery firing. Providing this type of information is no longer an impossibility. The Army, as the single manager of conventional munitions for the three military services, anticipated the tightening of data requirements and in the mid-1980s funded a study into technologies to characterize emissions produced by open-air destruction of propellants, explosives, and pyrotechnics. This study, conducted in cooperation with the US Environmental Protection Agency, has resulted in a unique testing system which gathers data from small detonations and burns and can accurately scale the data to allow characterizing combustion products of field open-burning/open-detonation disposal operations. The system and its technologies apply to other operations involving energetic materials. This paper describes the system (known as the BangBox Testing System), its component technologies, emerging results, and potential applications in the explosives and blasting industries.

  11. Manual for the prediction of blast and fragment loadings on structures

    SciTech Connect

    Not Available

    1980-11-01

    The purpose of this manual is to provide Architect-Engineer (AE) firms guidance for the prediction of air blast, ground shock and fragment loadings on structures as a result of accidental explosions in or near these structures. Information in this manual is the result of an extensive literature survey and data gathering effort, supplemented by some original analytical studies on various aspects of blast phenomena. Many prediction equations and graphs are presented, accompanied by numerous example problems illustrating their use. The manual is complementary to existing structural design manuals and is intended to reflect the current state-of-the-art in prediction of blast and fragment loads for accidental explosions of high explosives at the Pantex Plant. In some instances, particularly for explosions within blast-resistant structures of complex geometry, rational estimation of these loads is beyond the current state-of-the-art.

  12. HIGH PRODUCTIVITY VACUUM BLASTING SYSTEM

    SciTech Connect

    William S. McPhee

    1999-05-31

    The objective of this project is to improve the productivity and lower the expense of existing vacuum blasting technology. This technology is used to remove radioactive contamination, PCBs, and lead-based paint and provides worker protection by continuously recycling the material and dust for the decontamination tasks. The proposed work would increase the cleaning rate and provide safe and cost-effective decontamination of the DOE sites. This work focuses on redesigning and improving existing vacuum blasting technology including blast head nozzles, ergonomic handling of the blast head by reducing its weight; brush-ring design, vacuum level regulator, efficiency of the dust separator, and operational control sensors. The redesign is expected to enhance the productivity and economy of the vacuum blasting system by at least 50% over current vacuum blasting systems. There are three phases in the project. Phase I consists of developing and testing mathematical models. Phase II consists of pre-prototype design and fabrication and pre-prototype unit testing. Phase III consists of prototype design and field verification testing. In phase I, mathematical models are developed and analyzed for the nozzle, blast head, wind curtain, and dust separator, first as individual devices and then combined as an integrated model. This allows study of respective airflow and design parameters. The Contractor shall, based on the results of the mathematical modeling studies, design experimental models of the components and test these models. In addition, the Contractor shall develop sensors to detect the relationship of the blast head to the blast surfaces and controls to minimize the dependency on an operator's skill and judgment to obtain optimum positioning, as well as real-time characterization sensors to determine as the blast head is moving the depth to which coatings must be removed, thereby improving production and minimizing waste. In phase II, the Contractor shall design and

  13. Coal combustion under conditions of blast furnace injection. Final technical report, September 1, 1992--August 31, 1993

    SciTech Connect

    Crelling, J.C.; Case, E.R.

    1993-12-31

    A potentially new use for Illinois coal is as a fuel injected into a blast furnace to produce molten iron as the first step in steel production. Because of its increasing cost and decreasing availability, metallurgical coke is now being replaced by coal injected at the tuyere area of the furnace where the blast air enters. The purpose of this study is to evaluate the combustion of coal during the blast furnace injection process and to delineate the optimum properties of the feed coal. This investigation is significant to the use of Illinois coal in that the limited research to date suggests that coals of low fluidity and moderate to high sulfur and chlorine contents are suitable feedstocks for blast furnace injection. During the first phase of this project a number of the objectives were realized, specifically: (1) a blast furnace sampling system was developed and used successfully to collect samples inside an active furnace; (2) two sets of blast furnace samples were collected and petrographic analysis showed that char derived from injected coal is entering the reduction zone of the furnace; (3) a coal/char sampling probe was designed and fabricated; (4) the completion of a program of reactivity experiments on the injected coal char, blast furnace coke and Herrin No. 6 char. The results of the reactivity experiments indicate that Herrin No. 6 coal is similar or even superior to coals now being used in blast furnace injection and that additional testing is warranted.

  14. Assessment, development, and testing of glass for blast environments.

    SciTech Connect

    Glass, Sarah Jill

    2003-06-01

    Glass can have lethal effects including fatalities and injuries when it breaks and then flies through the air under blast loading (''the glass problem''). One goal of this program was to assess the glass problem and solutions being pursued to mitigate it. One solution to the problem is the development of new glass technology that allows the strength and fragmentation to be controlled or selected depending on the blast performance specifications. For example the glass could be weak and fail, or it could be strong and survive, but it must perform reliably. Also, once it fails it should produce fragments of a controlled size. Under certain circumstances it may be beneficial to have very small fragments, in others it may be beneficial to have large fragments that stay together. The second goal of this program was to evaluate the performance (strength, reliability, and fragmentation) of Engineered Stress Profile (ESP) glass under different loading conditions. These included pseudo-static strength and pressure tests and free-field blast tests. The ultimate goal was to provide engineers and architects with a glass whose behavior under blast loading is less lethal. A near-term benefit is a new approach for improving the reliability of glass and modifying its fracture behavior.

  15. A dynamic simulation of a lead blast furnace

    NASA Astrophysics Data System (ADS)

    Chao, John T.

    1981-06-01

    A dynamic model has been developed to simulate the operation of the stack zone of a lead blast furnace. The mathematical formulation of the governing equations of change leads to a system of 2nd order partial differential equations, which is solved by finite difference methods. A reduction model of ash-layer diffusion controlled mechanism, which allows the stepwise reduction to the lowest oxide or metal thermodynamically possible for the local gas composition within the sinter, is employed in this model. The surface reaction and the internal diffusion in the porous solid particles are taken into account in the coke gasification reaction. The profiles of the temperatures of gases and solids, solid compositions, and gas compositions and pressure in both radial and axial directions are predicted by the model. The results provide a good representation of the experimental data obtained for the blast furnace at Brunswick Mining and Smelting Corp., Ltd., New Brunswick, Canada and also of the less extensive data available for the Cominco blast furnace at Trail, British Columbia, Canada. In addition to the modelling of the stack, a mass and energy balance for the bosh zone is also included in the present calculation. The improvement of coke efficiency due to oxygen enrichment in the blast air for the Brunswick Furnace were interpreted semiquantitatively. The effect of sinter size distribution on the furnace performance has also been studied.

  16. Astrophysical blast wave data

    SciTech Connect

    Riley, Nathan; Geissel, Matthias; Lewis, Sean M; Porter, John L.

    2015-03-01

    The data described in this document consist of image files of shadowgraphs of astrophysically relevant laser driven blast waves. Supporting files include Mathematica notebooks containing design calculations, tabulated experimental data and notes, and relevant publications from the open research literature. The data was obtained on the Z-Beamlet laser from July to September 2014. Selected images and calculations will be published as part of a PhD dissertation and in associated publications in the open research literature, with Sandia credited as appropriate. The authors are not aware of any restrictions that could affect the release of the data.

  17. Noise and blast

    NASA Technical Reports Server (NTRS)

    Hodge, D. C.; Garinther, G. R.

    1973-01-01

    Noise and blast environments are described, providing a definition of units and techniques of noise measurement and giving representative booster-launch and spacecraft noise data. The effects of noise on hearing sensitivity and performance are reviewed, and community response to noise exposure is discussed. Physiological, or nonauditory, effects of noise exposure are also treated, as are design criteria and methods for minimizing the noise effects of hearing sensitivity and communications. The low level sound detection and speech reception are included, along with subjective and behavioral responses to noise.

  18. Centrifugal shot blast system

    SciTech Connect

    1998-02-01

    This report describes a demonstration of Concrete cleaning, Inc., modified centrifugal shot blast technology to remove the paint coating from concrete flooring. This demonstration is part of the Chicago Pile-5 (CP-5) Large-Scale Demonstration Project (LSDP) sponsored by the US Department of Energy (DOE), office of Science and Technology (OST), Deactivation and Decommissioning Focus Area (DDFA). The objective of the LSDP is to select and demonstrate potentially beneficial technologies at the Argonne National Laboratory-East (ANL) CP-5 Research Reactor. The purpose of the LSDP is to demonstrate that using innovative and improved decontamination and decommissioning (D and D) technologies from various sources can result in significant benefits, such as decreased cost and increased health and safety, as compared with baseline D and D technologies. Potential markets exist for the innovative centrifugal shot blast system at the following sites: Fernald Environmental Management Project, Los Alamos, Nevada, Oak Ridge Y-12 and K-25, Paducah, Portsmouth Gaseous Diffusion site, and the Savannah River Site. This information is based on a revision to the OST Linkage Tables dated August 4, 1997.

  19. A study of blast waveforms detected simultaneously by a microphone and a laser probe during laser ablation

    NASA Astrophysics Data System (ADS)

    Diaci, J.; Možina, J.

    1992-10-01

    We examine blast waves generated in air during irradiation of absorbing samples with Nd: YAG laser pulses of fluences exceeding the ablation threshold. Blast waves were detected simultaneously by a wideband microphone and a laser beam deflection probe. By a comparative analysis of both signals in the time and frequency domain we investigate characteristic features of their nonlinear waveform evolution. To explain the observed phenomena we employ the weak shock solution of the point explosion model.

  20. Placement of the dam for the no. 2 kambaratinskaya HPP by large-scale blasting: some observations

    SciTech Connect

    Shuifer, M. I.; Argal, E. S.

    2011-11-15

    Results of complex instrument observations of large-scale blasting during construction of the dam for the No. 2 Kambaratinskaya HPP on the Naryn River in the Republic of Kirgizia are analyzed. The purpose of these observations was: to determine the actual parameters of the seismic process, evaluate the effect of air and acoustic shock waves, and investigate the kinematics of the surface formed by the blast in its core region within the mass of fractured rocks.

  1. Portable convertible blast effects shield

    DOEpatents

    Pastrnak, John W.; Hollaway, Rocky; Henning, Carl D.; Deteresa, Steve; Grundler, Walter; Hagler, Lisle B.; Kokko, Edwin; Switzer, Vernon A

    2007-05-22

    A rapidly deployable portable convertible blast effects shield/ballistic shield includes a set two or more telescoping cylindrical rings operably connected to each other to convert between a telescopically-collapsed configuration for storage and transport, and a telescopically-extended upright configuration forming an expanded inner volume. In a first embodiment, the upright configuration provides blast effects shielding, such as against blast pressures, shrapnel, and/or fire balls. And in a second embodiment, the upright configuration provides ballistic shielding, such as against incoming weapons fire, shrapnel, etc. Each ring has a high-strength material construction, such as a composite fiber and matrix material, capable of substantially inhibiting blast effects and impinging projectiles from passing through the shield. And the set of rings are releasably securable to each other in the telescopically-extended upright configuration, such as by click locks.

  2. Portable convertible blast effects shield

    DOEpatents

    Pastrnak, John W.; Hollaway, Rocky; Henning, Carl D.; Deteresa, Steve; Grundler, Walter; Hagler,; Lisle B.; Kokko, Edwin; Switzer, Vernon A

    2010-10-26

    A rapidly deployable portable convertible blast effects shield/ballistic shield includes a set two or more telescoping cylindrical rings operably connected to each other to convert between a telescopically-collapsed configuration for storage and transport, and a telescopically-extended upright configuration forming an expanded inner volume. In a first embodiment, the upright configuration provides blast effects shielding, such as against blast pressures, shrapnel, and/or fire balls. And in a second embodiment, the upright configuration provides ballistic shielding, such as against incoming weapons fire, shrapnel, etc. Each ring has a high-strength material construction, such as a composite fiber and matrix material, capable of substantially inhibiting blast effects and impinging projectiles from passing through the shield. And the set of rings are releasably securable to each other in the telescopically-extended upright configuration, such as by click locks.

  3. Portable convertible blast effects shield

    DOEpatents

    Pastrnak, John W.; Hollaway, Rocky; Henning, Carl D.; Deteresa, Steve; Grundler, Walter; Hagler, Lisle B.; Kokko, Edwin; Switzer, Vernon A.

    2011-03-15

    A rapidly deployable portable convertible blast effects shield/ballistic shield includes a set two or more frusto-conically-tapered telescoping rings operably connected to each other to convert between a telescopically-collapsed configuration for storage and transport, and a telescopically-extended upright configuration forming an expanded inner volume. In a first embodiment, the upright configuration provides blast effects shielding, such as against blast pressures, shrapnel, and/or fire balls. And in a second embodiment, the upright configuration provides ballistic shielding, such as against incoming weapons fire, shrapnel, etc. Each ring has a high-strength material construction, such as a composite fiber and matrix material, capable of substantially inhibiting blast effects and impinging projectiles from passing through the shield. And the set of rings are releasably securable to each other in the telescopically-extended upright configuration by the friction fit of adjacent pairs of frusto-conically-tapered rings to each other.

  4. Blast waves with cosmic rays

    NASA Astrophysics Data System (ADS)

    Arbutina, B.

    2015-04-01

    Blast waves appear in many astrophysical phenomena, such as supernovae. In this paper we discuss blast waves with cosmic rays, i.e., with a component with a power-law number density distribution function N( p) ∝ p -Γ that may be particulary important in describing the evolution of supernova remnants. We confirm some previous findings that a significant amount of cosmic ray energy is deposited towards the center of a remnant.

  5. 78 FR 54835 - Air Quality Implementation Plan; Alabama; Attainment Plan for the Troy Area 2008 Lead...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-06

    ... hoods over each blast furnace and compliance with the Secondary Lead MACT (40 CFR Part 63, Subpart X... hoods over each blast furnace with supply air to reduce worker lead exposures. Additionally, the furnace... background for EPA's proposed action? On November 12, 2008 (73 FR 66964), EPA revised the Lead...

  6. Quarry blasts assessment and their environmental impacts on the nearby oil pipelines, southeast of Helwan City, Egypt

    NASA Astrophysics Data System (ADS)

    Mohamed, Adel M. E.; Mohamed, Abuo El-Ela A.

    2013-06-01

    Ground vibrations induced by blasting in the cement quarries are one of the fundamental problems in the quarrying industry and may cause severe damage to the nearby utilities and pipelines. Therefore, a vibration control study plays an important role in the minimization of environmental effects of blasting in quarries. The current paper presents the influence of the quarry blasts at the National Cement Company (NCC) on the two oil pipelines of SUMED Company southeast of Helwan City, by measuring the ground vibrations in terms of Peak Particle Velocity (PPV). The seismic refraction for compressional waves deduced from the shallow seismic survey and the shear wave velocity obtained from the Multi channel Analysis of Surface Waves (MASW) technique are used to evaluate the closest site of the two pipelines to the quarry blasts. The results demonstrate that, the closest site of the two pipelines is of class B, according to the National Earthquake Hazard Reduction Program (NEHRP) classification and the safe distance to avoid any environmental effects is 650 m, following the deduced Peak Particle Velocity (PPV) and scaled distance (SD) relationship (PPV = 700.08 × SD-1.225) in mm/s and the Air over Pressure (air blast) formula (air blast = 170.23 × SD-0.071) in dB. In the light of prediction analysis, the maximum allowable charge weight per delay was found to be 591 kg with damage criterion of 12.5 mm/s at the closest site of the SUMED pipelines.

  7. Blast Quantification Using Hopkinson Pressure Bars.

    PubMed

    Clarke, Samuel D; Fay, Stephen D; Rigby, Samuel E; Tyas, Andrew; Warren, James A; Reay, Jonathan J; Fuller, Benjamin J; Gant, Matthew T A; Elgy, Ian D

    2016-07-05

    Near-field blast load measurement presents an issue to many sensor types as they must endure very aggressive environments and be able to measure pressures up to many hundreds of megapascals. In this respect the simplicity of the Hopkinson pressure bar has a major advantage in that while the measurement end of the Hopkinson bar can endure and be exposed to harsh conditions, the strain gauge mounted to the bar can be affixed some distance away. This allows protective housings to be utilized which protect the strain gauge but do not interfere with the measurement acquisition. The use of an array of pressure bars allows the pressure-time histories at discrete known points to be measured. This article also describes the interpolation routine used to derive pressure-time histories at un-instrumented locations on the plane of interest. Currently the technique has been used to measure loading from high explosives in free air and buried shallowly in various soils.

  8. Blast mitigation capabilities of aqueous foam.

    SciTech Connect

    Hartman, William Franklin; Larsen, Marvin Elwood; Boughton, Bruce A.

    2006-02-01

    A series of tests involving detonation of high explosive blanketed by aqueous foam (conducted from 1982 to 1984) are described in primarily terms of recorded peak pressure, positive phase specific impulse, and time of arrival. The investigation showed that optimal blast mitigation occurs for foams with an expansion ratio of about 60:1. Simple analyses representing the foam as a shocked single phase mixture are presented and shown inadequate. The experimental data demonstrate that foam slows down and broadens the propagated pressure disturbance relative to a shock in air. Shaped charges and flyer plates were evaluated for operation in foam and appreciable degradation was observed for the flyer plates due to drag created by the foam.

  9. Primary blast injury after a bomb explosion in a civilian bus.

    PubMed

    Katz, E; Ofek, B; Adler, J; Abramowitz, H B; Krausz, M M

    1989-04-01

    A 6-kg explosive charge detonated under a seat in the center of a crowded city bus in Jerusalem, killing three passengers immediately. Of the 55 survivors, all of whom were transferred to two major medical centers, 29 were hospitalized. Among those admitted, a high rate of primary blast injuries was found, including perforated ear drums (76%), blast lung (38%), and abdominal blast injuries (14%). Two of the latter patients suffered bowel perforations, which were diagnosed with considerable delay. Eight patients (31%) had sustained life-threatening trauma, consisting of a combination of primary, secondary, and tertiary blast injuries. The overall mortality rate was 10.3%. The large number of primary blast injuries, including the unexpected finding of bowel perforations, is explained by the high amplitude of the air pressure wave (3.8-5.2 atm) and its relatively long duration (2-3 msec) resulting from the detonation of the high-energy explosive charge in the small, enclosed space of the bus. Besides the usual wounds sustained by victims of an explosion that occurs in a confined space, the possibility of primary blast injury to the abdomen and to the lungs should be taken into account by the treating surgeon.

  10. New findings on the impact of an explosive VOD on blast results

    SciTech Connect

    Chiappetta, R.F.

    1994-12-31

    An explosive`s velocity of detonation (VOD), can be used to indicate a number of important characteristics regarding the product`s performance under specific field and test conditions. A number of new characteristic and transient VOD curves have been identified in the field, which can be used to evaluate explosive performance, control ground vibration amplitudes and frequencies, select the correct amount and type of stemming for use at the collar and in stem decks, eliminate explosive desensitization, evaluate primer performance, design air deck based blasts, evaluate contaminated explosives and to overcome post blast noxious fumes. Tests were conducted over a six year period in single and multi-hole blasts using laboratory and full scale blast environments. Explosives tested ranged from pure Emulsion to Anfo and various grades of Emulsion/Anfo blends. Field test parameters were; borehole diameter (1 1/2--30 inches), hole depths (10--120 feet), primer size (0.5--6.4 pounds) and the blast environment varied from soft, jelly-like tar sands to some of the hardest iron ore formations. Most tests were instrumented with an array of blast monitoring instrumentation systems consisting of continuous velocity of detonation recorders, high-speed 16 mm cameras, laser-surveying instrumentation and seismographs which were placed in the near and far fields.

  11. Use Of High-Speed Motion Picture Photography In Blast Evaluation And Design

    NASA Astrophysics Data System (ADS)

    Chiappetta, R. F.; Mammele, Mark E.

    1988-02-01

    A useful and foolproof method of analyzing explosive phenomena and designing blasts is with information obtained from high-speed, 16mm motion picture photography. Utilizing this information along with the methodologies developed adds confidence to custom and site specific blast designs for use in mining, quarry, coal, utility, construction, research and specialized military applications. The numerical and analytical techniques developed allow a blaster or engineer to evaluate blasting performance, compare explosive efficiencies, optimize millisecond delay timing between detonations, evaluate damage to particular seams of material such as coal, optimize overburden casting, predict explosive energy required to displace toe burdens, compare over-all blast designs, investigate air decks for presplitting and reclamation purposes, and to study general detonation phenomena. Results are based on the analysis of a few hundred films of blasts performed in full-scale production environments. Instrumentation, field set-ups, and specific data interpre-tation are discussed in detail. The presentation is also supplemented with a 10 minute film of selected test blasts.

  12. Primary blast injury after a bomb explosion in a civilian bus.

    PubMed Central

    Katz, E; Ofek, B; Adler, J; Abramowitz, H B; Krausz, M M

    1989-01-01

    A 6-kg explosive charge detonated under a seat in the center of a crowded city bus in Jerusalem, killing three passengers immediately. Of the 55 survivors, all of whom were transferred to two major medical centers, 29 were hospitalized. Among those admitted, a high rate of primary blast injuries was found, including perforated ear drums (76%), blast lung (38%), and abdominal blast injuries (14%). Two of the latter patients suffered bowel perforations, which were diagnosed with considerable delay. Eight patients (31%) had sustained life-threatening trauma, consisting of a combination of primary, secondary, and tertiary blast injuries. The overall mortality rate was 10.3%. The large number of primary blast injuries, including the unexpected finding of bowel perforations, is explained by the high amplitude of the air pressure wave (3.8-5.2 atm) and its relatively long duration (2-3 msec) resulting from the detonation of the high-energy explosive charge in the small, enclosed space of the bus. Besides the usual wounds sustained by victims of an explosion that occurs in a confined space, the possibility of primary blast injury to the abdomen and to the lungs should be taken into account by the treating surgeon. Images Fig. 5. PMID:2930293

  13. 30 CFR 75.1323 - Blasting circuits.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...) Blasting circuits shall be protected from sources of stray electric current. (b) Detonators made by different manufacturers shall not be combined in the same blasting circuit. (c) Detonator leg wires shall be... used between the blasting cable and detonator circuitry shall— (1) Be undamaged; (2) Be well...

  14. 30 CFR 75.1323 - Blasting circuits.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...) Blasting circuits shall be protected from sources of stray electric current. (b) Detonators made by different manufacturers shall not be combined in the same blasting circuit. (c) Detonator leg wires shall be... used between the blasting cable and detonator circuitry shall— (1) Be undamaged; (2) Be well...

  15. 30 CFR 56.6803 - Blasting lines.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Explosives Maintenance § 56.6803 Blasting lines. Permanent blasting lines shall be properly supported. All blasting lines shall be...

  16. Thermal Spray Coatings for Blast Furnace Tuyere Application

    NASA Astrophysics Data System (ADS)

    Pathak, A.; Sivakumar, G.; Prusty, D.; Shalini, J.; Dutta, M.; Joshi, S. V.

    2015-12-01

    The components in an integrated steel plant are invariably exposed to harsh working environments involving exposure to high temperatures, corrosive gases, and erosion/wear conditions. One such critical component in the blast furnace is the tuyere, which is prone to thermal damage by splashing of molten metal/slag, erosive damage by falling burden material, and corrosion from the ensuing gases. All the above, collectively or independently, accelerate tuyere failure, which presents a potential explosion hazard in a blast furnace. Recently, thermal spray coatings have emerged as an effective solution to mitigate such severe operational challenges. In the present work, five different coatings deposited using detonation spray and air plasma spray techniques were comprehensively characterized. Performance evaluation involving thermal cycling, hot corrosion, and erosion tests was also carried out. Based on the studies, a coating system was suggested for possible tuyere applications and found to yield substantial improvement in service life during actual field trials.

  17. Microscopic origin of self-similarity in granular blast waves

    NASA Astrophysics Data System (ADS)

    Barbier, M.; Villamaina, D.; Trizac, E.

    2016-08-01

    The self-similar expansion of a blast wave, well-studied in air, has peculiar counterparts in dense and dissipative media such as granular gases. Recent results have shown that, while the traditional Taylor-von Neumann-Sedov (TvNS) derivation is not applicable to such granular blasts, they can nevertheless be well understood via a combination of microscopic and hydrodynamic insights. In this article, we provide a detailed analysis of these methods associating molecular dynamics simulations and continuum equations, which successfully predict hydrodynamic profiles, scaling properties, and the instability of the self-similar solution. We also present new results for the energy conserving case, including the particle-level analysis of the classic TvNS solution and its breakdown at higher densities.

  18. Small-Scale Shock Reactivity and Internal Blast Test

    NASA Astrophysics Data System (ADS)

    Granholm, R. H.; Sandusky, H. W.

    2006-07-01

    Explosives react from a strong shock, even in quantities too small for detonation. The potential for a new material to be an explosive can be evaluated from this shock reactivity. The recently developed small-scale shock reactivity test (SSRT) uses very high confinement to allow prompt reactions to occur in less than half-gram samples well below critical diameter. Early and late-time reactions are simultaneously measured from a single sample subjected to the output from an RP-80 detonator. Prompt reactions are quantified by a dent in a soft aluminum witness block, while later reactions, such as from fuel/air combustion, are measured by recording blast pressure. Internal blast quasi-static pressure is obtained by confining the sample apparatus within a three-liter chamber. Late-time reaction effects of plastics, and results from HMX, HMX/Aluminum, and a plastic-bonded explosive (PBX) are reported.

  19. Toxicology of blast overpressure.

    PubMed

    Elsayed, N M

    1997-07-25

    Blast overpressure (BOP) or high energy impulse noise, is the sharp instantaneous rise in ambient atmospheric pressure resulting from explosive detonation or firing of weapons. Blasts that were once confined to military and to a lesser extent, occupational settings, are becoming more universal as the civilian population is now increasingly at risk of exposure to BOP from terrorist bombings that are occurring worldwide with greater frequency. Exposure to incident BOP waves can cause auditory and non-auditory damage. The primary targets for BOP damage are the hollow organs, ear, lung and gastrointestinal tract. In addition, solid organs such as heart, spleen and brain can also be injured upon exposure. However, the lung is more sensitive to damage and its injury can lead to death. The pathophysiological responses, and mortality have been extensively studied, but little attention, was given to the biochemical manifestations, and molecular mechanism(s) of injury. The injury from BOP has been, generally, attributed to its external physical impact on the body causing internal mechanical damage. However, a new hypothesis has been proposed based on experiments conducted in the Department of Respiratory Research, Walter Reed Army Institute of Research, and later in the Department of Occupational Health, University of Pittsburgh. This hypothesis suggests that subtle biochemical changes namely, free radical-mediated oxidative stress occur and contribute to BOP-induced injury. Understanding the etiology of these changes may shed new light on the molecular mechanism(s) of injury, and can potentially offer new strategies for treatment. In this symposium. BOP research involving auditory, non-auditory, physiological, pathological, behavioral, and biochemical manifestations as well as predictive modeling and current treatment modalities of BOP-induced injury are discussed.

  20. Toxicology of blast overpressure.

    PubMed

    Elsayed, N M

    1997-07-25

    Blast overpressure (BOP) or high energy impulse noise, is the sharp instantaneous rise in ambient atmospheric pressure resulting from explosive detonation or firing of weapons. Blasts that were once confined to military and to a lesser extent, occupational settings, are becoming more universal as the civilian population is now increasingly at risk of exposure to BOP from terrorist bombings that are occurring worldwide with greater frequency. Exposure to incident BOP waves can cause auditory and non-auditory damage. The primary targets for BOP damage are the hollow organs, ear, lung and gastrointestinal tract. In addition, solid organs such as heart, spleen and brain can also be injured upon exposure. However, the lung is more sensitive to damage and its injury can lead to death. The pathophysiological responses, and mortality have been extensively studied, but little attention, was given to the biochemical manifestations, and molecular mechanism(s) of injury. The injury from BOP has been, generally, attributed to its external physical impact on the body causing internal mechanical damage. However, a new hypothesis has been proposed based on experiments conducted in the Department of Respiratory Research, Walter Reed Army Institute of Research, and later in the Department of Occupational Health, University of Pittsburgh. This hypothesis suggests that subtle biochemical changes namely, free radical-mediated oxidative stress occur and contribute to BOP-induced injury. Understanding the etiology of these changes may shed new light on the molecular mechanism(s) of injury, and can potentially offer new strategies for treatment. In this symposium. BOP research involving auditory, non-auditory, physiological, pathological, behavioral, and biochemical manifestations as well as predictive modeling and current treatment modalities of BOP-induced injury are discussed. PMID:9217311

  1. Membrane characteristics for biological blast overpressure testing using blast simulators.

    PubMed

    Alphonse, Vanessa D; Siva Sai Sujith Sajja, Venkata; Kemper, Andrew R; Rizel, Dave V; Duma, Stefan M; VandeVord, Pamela J

    2014-01-01

    Blast simulators often use passive-rupture membranes to generate shock waves similar to free-field blasts. The purpose of this study was to compare rupture patterns and pressure traces of three distinct membrane materials for biological and biomechanical blast studies. An Advanced Blast Simulator (ABS) located at the Center for Injury Biomechanics at Virginia Tech was used to test membrane characteristics. Acetate, Mylar, and aluminum sheets with different thicknesses were used to obtain pressures between 70–210 kPa. Static pressure was measured inside the tube at the test section using piezoelectric pressure sensors. Peak overpressure, positive duration, and positive impulse were calculated for each test. Rupture patterns and characteristic pressure traces were unique to each membrane type and thickness. Shock wave speed ranged between 1.2-1.8 Mach for static overpressures of 70–210 kPa. Acetate membranes fragmented sending pieces down the tube, but produced ideal (Friedlander) pressure traces. Mylar membranes bulged without fragmenting, but produced less-than-ideal pressure traces. Aluminum membranes did not fragment and produced ideal pressure traces. However, the cost of manufacturing and characterizing aluminum membranes should be considered during membrane selection. This study illustrates the advantages and disadvantages of using Mylar, acetate, and aluminum for passive rupture membranes for blast simulators. PMID:25405432

  2. Dynamic response and optimal design of curved metallic sandwich panels under blast loading.

    PubMed

    Qi, Chang; Yang, Shu; Yang, Li-Jun; Han, Shou-Hong; Lu, Zhen-Hua

    2014-01-01

    It is important to understand the effect of curvature on the blast response of curved structures so as to seek the optimal configurations of such structures with improved blast resistance. In this study, the dynamic response and protective performance of a type of curved metallic sandwich panel subjected to air blast loading were examined using LS-DYNA. The numerical methods were validated using experimental data in the literature. The curved panel consisted of an aluminum alloy outer face and a rolled homogeneous armour (RHA) steel inner face in addition to a closed-cell aluminum foam core. The results showed that the configuration of a "soft" outer face and a "hard" inner face worked well for the curved sandwich panel against air blast loading in terms of maximum deflection (MaxD) and energy absorption. The panel curvature was found to have a monotonic effect on the specific energy absorption (SEA) and a nonmonotonic effect on the MaxD of the panel. Based on artificial neural network (ANN) metamodels, multiobjective optimization designs of the panel were carried out. The optimization results revealed the trade-off relationships between the blast-resistant and the lightweight objectives and showed the great use of Pareto front in such design circumstances.

  3. Dynamic Response and Optimal Design of Curved Metallic Sandwich Panels under Blast Loading

    PubMed Central

    Yang, Shu; Han, Shou-Hong; Lu, Zhen-Hua

    2014-01-01

    It is important to understand the effect of curvature on the blast response of curved structures so as to seek the optimal configurations of such structures with improved blast resistance. In this study, the dynamic response and protective performance of a type of curved metallic sandwich panel subjected to air blast loading were examined using LS-DYNA. The numerical methods were validated using experimental data in the literature. The curved panel consisted of an aluminum alloy outer face and a rolled homogeneous armour (RHA) steel inner face in addition to a closed-cell aluminum foam core. The results showed that the configuration of a “soft” outer face and a “hard” inner face worked well for the curved sandwich panel against air blast loading in terms of maximum deflection (MaxD) and energy absorption. The panel curvature was found to have a monotonic effect on the specific energy absorption (SEA) and a nonmonotonic effect on the MaxD of the panel. Based on artificial neural network (ANN) metamodels, multiobjective optimization designs of the panel were carried out. The optimization results revealed the trade-off relationships between the blast-resistant and the lightweight objectives and showed the great use of Pareto front in such design circumstances. PMID:25126606

  4. Quick reproduction of blast-wave flow-field properties of nuclear, TNT, and ANFO explosions

    NASA Astrophysics Data System (ADS)

    Groth, C. P. T.

    1986-04-01

    In many instances, extensive blast-wave flow-field properties are required in gasdynamics research studies of blast-wave loading and structure response, and in evaluating the effects of explosions on their environment. This report provides a very useful computer code, which can be used in conjunction with the DNA Nuclear Blast Standard subroutines and code, to quickly reconstruct complete and fairly accurate blast-wave data for almost any free-air (spherical) and surface-burst (hemispherical) nuclear, trinitrotoluene (TNT), or ammonium nitrate-fuel oil (ANFO) explosion. This code is capable of computing all of the main flow properties as functions of radius and time, as well as providing additional information regarding air viscosity, reflected shock-wave properties, and the initial decay of the flow properties just behind the shock front. Both spatial and temporal distributions of the major blast-wave flow properties are also made readily available. Finally, provisions are also included in the code to provide additional information regarding the peak or shock-front flow properties over a range of radii, for a specific explosion of interest.

  5. 48 CFR 1352.271-72 - Additional Item Requirements (AIR)-growth work

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Clauses 1352.271-72 Additional Item Requirements (AIR)—growth work As prescribed in 48 CFR 1371.103... Cleaning/Water Blasting, Tank Cleaning, Welding, Burning, Brazing, Blacksmithing, Machining (inside...

  6. 48 CFR 1352.271-72 - Additional Item Requirements (AIR)-growth work

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Clauses 1352.271-72 Additional Item Requirements (AIR)—growth work As prescribed in 48 CFR 1371.103... Cleaning/Water Blasting, Tank Cleaning, Welding, Burning, Brazing, Blacksmithing, Machining (inside...

  7. Study on the Mechanism of Adhesion Improvement Using Dry-Ice Blasting for Plasma-Sprayed Al2O3 Coatings

    NASA Astrophysics Data System (ADS)

    Dong, Shujuan; Song, Bo; Hansz, Bernard; Liao, Hanlin; Coddet, Christian

    2013-03-01

    The mechanisms of adhesion improvement of plasma-sprayed Al2O3 coatings using dry-ice blasting were investigated. In this study, the change of substrate surface characteristics in both the topography and the wettability due to the treatment of dry-ice blasting was mainly studied. The effect of dry-ice blasting on Al2O3 splat morphology with different treatment durations was also examined. The residual stress of plasma-sprayed Al2O3 coatings using dry-ice blasting was measured by curvature method and compared to that of coatings deposited with conventional air cooling. Based on these numerous assessment tests, it could be concluded that the adhesion improvement of Al2O3 coatings could be attributed to the cleaning effect of dry-ice blasting on different organic substances adsorbed on the substrates and the peening effect.

  8. A Novel Closed-Head Model of Mild Traumatic Brain Injury Caused by Primary Overpressure Blast to the Cranium Produces Sustained Emotional Deficits in Mice

    PubMed Central

    Heldt, Scott A.; Elberger, Andrea J.; Deng, Yunping; Guley, Natalie H.; Del Mar, Nobel; Rogers, Joshua; Choi, Gy Won; Ferrell, Jessica; Rex, Tonia S.; Honig, Marcia G.; Reiner, Anton

    2014-01-01

    Emotional disorders are a common outcome from mild traumatic brain injury (TBI) in humans, but their pathophysiological basis is poorly understood. We have developed a mouse model of closed-head blast injury using an air pressure wave delivered to a small area on one side of the cranium, to create mild TBI. We found that 20-psi blasts in 3-month-old C57BL/6 male mice yielded no obvious behavioral or histological evidence of brain injury, while 25–40 psi blasts produced transient anxiety in an open field arena but little histological evidence of brain damage. By contrast, 50–60 psi blasts resulted in anxiety-like behavior in an open field arena that became more evident with time after blast. In additional behavioral tests conducted 2–8 weeks after blast, 50–60 psi mice also demonstrated increased acoustic startle, perseverance of learned fear, and enhanced contextual fear, as well as depression-like behavior and diminished prepulse inhibition. We found no evident cerebral pathology, but did observe scattered axonal degeneration in brain sections from 50 to 60 psi mice 3–8 weeks after blast. Thus, the TBI caused by single 50–60 psi blasts in mice exhibits the minimal neuronal loss coupled to “diffuse” axonal injury characteristic of human mild TBI. A reduction in the abundance of a subpopulation of excitatory projection neurons in basolateral amygdala enriched in Thy1 was, however, observed. The reported link of this neuronal population to fear suppression suggests their damage by mild TBI may contribute to the heightened anxiety and fearfulness observed after blast in our mice. Our overpressure air blast model of concussion in mice will enable further studies of the mechanisms underlying the diverse emotional deficits seen after mild TBI. PMID:24478749

  9. A novel closed-head model of mild traumatic brain injury caused by primary overpressure blast to the cranium produces sustained emotional deficits in mice.

    PubMed

    Heldt, Scott A; Elberger, Andrea J; Deng, Yunping; Guley, Natalie H; Del Mar, Nobel; Rogers, Joshua; Choi, Gy Won; Ferrell, Jessica; Rex, Tonia S; Honig, Marcia G; Reiner, Anton

    2014-01-01

    Emotional disorders are a common outcome from mild traumatic brain injury (TBI) in humans, but their pathophysiological basis is poorly understood. We have developed a mouse model of closed-head blast injury using an air pressure wave delivered to a small area on one side of the cranium, to create mild TBI. We found that 20-psi blasts in 3-month-old C57BL/6 male mice yielded no obvious behavioral or histological evidence of brain injury, while 25-40 psi blasts produced transient anxiety in an open field arena but little histological evidence of brain damage. By contrast, 50-60 psi blasts resulted in anxiety-like behavior in an open field arena that became more evident with time after blast. In additional behavioral tests conducted 2-8 weeks after blast, 50-60 psi mice also demonstrated increased acoustic startle, perseverance of learned fear, and enhanced contextual fear, as well as depression-like behavior and diminished prepulse inhibition. We found no evident cerebral pathology, but did observe scattered axonal degeneration in brain sections from 50 to 60 psi mice 3-8 weeks after blast. Thus, the TBI caused by single 50-60 psi blasts in mice exhibits the minimal neuronal loss coupled to "diffuse" axonal injury characteristic of human mild TBI. A reduction in the abundance of a subpopulation of excitatory projection neurons in basolateral amygdala enriched in Thy1 was, however, observed. The reported link of this neuronal population to fear suppression suggests their damage by mild TBI may contribute to the heightened anxiety and fearfulness observed after blast in our mice. Our overpressure air blast model of concussion in mice will enable further studies of the mechanisms underlying the diverse emotional deficits seen after mild TBI. PMID:24478749

  10. 30 CFR 56.6605 - Isolation of blasting circuits.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Extraneous Electricity § 56.6605 Isolation of blasting circuits. Lead wires and blasting lines shall be... sources of stray or static electricity. Blasting circuits shall be protected from any contact...

  11. 30 CFR 56.6605 - Isolation of blasting circuits.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Extraneous Electricity § 56.6605 Isolation of blasting circuits. Lead wires and blasting lines shall be... sources of stray or static electricity. Blasting circuits shall be protected from any contact...

  12. 30 CFR 56.6605 - Isolation of blasting circuits.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Extraneous Electricity § 56.6605 Isolation of blasting circuits. Lead wires and blasting lines shall be... sources of stray or static electricity. Blasting circuits shall be protected from any contact...

  13. 30 CFR 56.6605 - Isolation of blasting circuits.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Extraneous Electricity § 56.6605 Isolation of blasting circuits. Lead wires and blasting lines shall be... sources of stray or static electricity. Blasting circuits shall be protected from any contact...

  14. 9. LOOKING NORTH AT TRESTLE, HOIST HOUSE No. 1, BLAST ...

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

    9. LOOKING NORTH AT TRESTLE, HOIST HOUSE No. 1, BLAST FURNACE No. 1, AND HOT BLAST STOVES. (Jet Lowe) - U.S. Steel Duquesne Works, Blast Furnace Plant, Along Monongahela River, Duquesne, Allegheny County, PA

  15. Looking east at blast furnace no. 5 between the hot ...

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

    Looking east at blast furnace no. 5 between the hot blast stoves (left) and the dustcatcher (right). - U.S. Steel Edgar Thomson Works, Blast Furnace Plant, Along Monongahela River, Braddock, Allegheny County, PA

  16. Looking southeast at blast furnaces no. 5 and no. 6 ...

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

    Looking southeast at blast furnaces no. 5 and no. 6 with blast furnace trestle and Gondola Railroad cars in foreground. - U.S. Steel Edgar Thomson Works, Blast Furnace Plant, Along Monongahela River, Braddock, Allegheny County, PA

  17. GENERAL VIEW OF TURBOBLOWER BUILDING (LEFT), BLAST FURNACE (CENTER), AND ...

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

    GENERAL VIEW OF TURBO-BLOWER BUILDING (LEFT), BLAST FURNACE (CENTER), AND HOT BLAST STOVES (RIGHT). - Republic Iron & Steel Company, Youngstown Works, Haselton Blast Furnaces, West of Center Street Viaduct, along Mahoning River, Youngstown, Mahoning County, OH

  18. Looking southwest at blast furnaces no. 5 and no. 6 ...

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

    Looking southwest at blast furnaces no. 5 and no. 6 with blast furnace trestle and Gondola Railroad cars in foreground. - U.S. Steel Edgar Thomson Works, Blast Furnace Plant, Along Monongahela River, Braddock, Allegheny County, PA

  19. INTERIOR VIEW LOOKING WEST, CAST HOUSE OF BLAST FURNACE NO. ...

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

    INTERIOR VIEW LOOKING WEST, CAST HOUSE OF BLAST FURNACE NO. 1 AND BLAST FURNACE NO. 2. - Pittsburgh Steel Company, Monessen Works, Blast Furnace No. 1 & No. 2, Donner Avenue, Monessen, Westmoreland County, PA

  20. 30 CFR 56.6605 - Isolation of blasting circuits.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... sources of stray or static electricity. Blasting circuits shall be protected from any contact between... Extraneous Electricity § 56.6605 Isolation of blasting circuits. Lead wires and blasting lines shall...

  1. Porcine Head Response to Blast

    PubMed Central

    Shridharani, Jay K.; Wood, Garrett W.; Panzer, Matthew B.; Capehart, Bruce P.; Nyein, Michelle K.; Radovitzky, Raul A.; Bass, Cameron R. ‘Dale’

    2012-01-01

    Recent studies have shown an increase in the frequency of traumatic brain injuries related to blast exposure. However, the mechanisms that cause blast neurotrauma are unknown. Blast neurotrauma research using computational models has been one method to elucidate that response of the brain in blast, and to identify possible mechanical correlates of injury. However, model validation against experimental data is required to ensure that the model output is representative of in vivo biomechanical response. This study exposes porcine subjects to primary blast overpressures generated using a compressed-gas shock tube. Shock tube blasts were directed to the unprotected head of each animal while the lungs and thorax were protected using ballistic protective vests similar to those employed in theater. The test conditions ranged from 110 to 740 kPa peak incident overpressure with scaled durations from 1.3 to 6.9 ms and correspond approximately with a 50% injury risk for brain bleeding and apnea in a ferret model scaled to porcine exposure. Instrumentation was placed on the porcine head to measure bulk acceleration, pressure at the surface of the head, and pressure inside the cranial cavity. Immediately after the blast, 5 of the 20 animals tested were apneic. Three subjects recovered without intervention within 30 s and the remaining two recovered within 8 min following respiratory assistance and administration of the respiratory stimulant doxapram. Gross examination of the brain revealed no indication of bleeding. Intracranial pressures ranged from 80 to 390 kPa as a result of the blast and were notably lower than the shock tube reflected pressures of 300–2830 kPa, indicating pressure attenuation by the skull up to a factor of 8.4. Peak head accelerations were measured from 385 to 3845 G’s and were well correlated with peak incident overpressure (R2 = 0.90). One SD corridors for the surface pressure, intracranial pressure (ICP), and head acceleration are

  2. Blast waves in rotating media.

    NASA Technical Reports Server (NTRS)

    Rossner, L. F.

    1972-01-01

    The model investigated involves a cylindrically symmetric blast wave generated by an infinitely long line explosion in a cold and homogeneous gas rotating rigidly in its self-gravitational field. It is found that within the context of rotation in a gravitational field a blast wave will not adopt the one-zone form familiar from similarity solutions but, rather, a two-zone form. The inner compression zone arises as a response to the presence of the restoring force, which drives a rarefaction wave into the outer compression zone.

  3. Numerical study of rock blasting

    NASA Astrophysics Data System (ADS)

    Stefanov, Yu. P.; Bakeev, R. A.; Yudin, A. S.; Kuznetsova, N. S.

    2015-10-01

    The paper presents numerical simulation results on fracture of a concrete block due to dynamic explosive loads applied to the walls of a blast hole. Considered in the study is the influence of the pulse shape and rock properties on the pattern of irreversible deformation and cracking. It is found that a fractured zone bounded by a plastically deformed contour always arises around the explosion site. Comparison of elastoplastic deformation and fracture induced in the concrete block by explosion pulses of different durations and amplitudes shows that shorter pulses with higher amplitudes and steeper rise times provide a higher blasting efficiency.

  4. Community response to blast noise

    NASA Astrophysics Data System (ADS)

    Nykaza, Edward T.; Pater, Larry L.; Fidell, Sanford; Schomer, Paul

    2005-09-01

    Although community response to impulsive noise from military operations is usually discussed for NEPA-related purposes in terms of the prevalence of annoyance, it is managed on a local, daily basis in terms of numbers of recent complaints. Reconciling blast noise complaint rates with the annoyance predicted by dosage-effect analysis would be of considerable benefit to the Army, since it would provide insight into the dynamics of community reaction to this distinctive form of noise exposure, and put its assessment and management on a common footing. This paper describes a systematic approach to the challenges of quantifying community reaction to blast noise. [Work supported by ERDC-CERL.

  5. LTC vacuum blasting machine (metal): Baseline report; Summary

    SciTech Connect

    1997-07-31

    The LTC coating removal system consists of several hand tools such as a Roto Peen scaler and a needlegun. They are designed to remove coatings from steel, concrete, brick, and wood. These are used with the LTC PTC-6 vacuum system to capture dust and debris as removal of the coating takes place. The PTC-6 is a vacuum system designed to be used with surface decontamination equipment. Dust and debris are captured by a high efficiency particulate filter (HEPA) vacuum system that deposits the waste directly into an on-board 23-gallon waste drum. The PTC-6 utilizes compressed air delivered from a source via an air hose connected to the air inlet to drive the hand held power tools. The control panel regulated the air pressure delivered to the tool. A separate compressed air flow powers the vacuum generator. The vacuum hoses connect the power tools to the dust chamber, returning paint chips and dust from the surface. A third compressed air flow is used to clean filters by pulsing air through a pipe with slots. The blasts of air shake dust and debris from the filter fabric.

  6. Implicit Newton-Krylov methods for modeling blast furnace stoves

    SciTech Connect

    Howse, J.W.; Hansen, G.A.; Cagliostro, D.J.; Muske, K.R.

    1998-03-01

    In this paper the authors discuss the use of an implicit Newton-Krylov method to solve a set of partial differential equations representing a physical model of a blast furnace stove. The blast furnace stove is an integral part of the iron making process in the steel industry. These stoves are used to heat air which is then used in the blast furnace to chemically reduce iron ore to iron metal. The solution technique used to solve the discrete representations of the model and control PDE`s must be robust to linear systems with disparate eigenvalues, and must converge rapidly without using tuning parameters. The disparity in eigenvalues is created by the different time scales for convection in the gas, and conduction in the brick; combined with a difference between the scaling of the model and control PDE`s. A preconditioned implicit Newton-Krylov solution technique was employed. The procedure employs Newton`s method, where the update to the current solution at each stage is computed by solving a linear system. This linear system is obtained by linearizing the discrete approximation to the PDE`s, using a numerical approximation for the Jacobian of the discretized system. This linear system is then solved for the needed update using a preconditioned Krylov subspace projection method.

  7. Probabilistic Exposure Assessment for Applicators during Treatment of the Fungicide Kresoxim-methyl on an Apple Orchard by a Speed Sprayer.

    PubMed

    Kim, Eunhye; Moon, Joon-Kwan; Choi, Hoon; Kim, Jeong-Han

    2015-12-01

    Probabilistic exposure and risk assessment of kresoxim-methyl were conducted for agricultural applicators during preparation of spray suspension and application with a speed sprayer on an apple orchard. The preparation and application of 1000 L of spray suspension were repeated 30 times. Several exposure matrices, including patches, cotton gloves, socks, masks, and XAD-2 resin, were used to measure the potential exposure for workers. The analytical methods were fully validated to guarantee the precision and accuracy of analysis. The exposure amount on hands for mixer/loader was 0.7 mg [95% confidence interval (CI) from 0.02 to 2.4], taking 0.0005% (95% CI from 1.2 × 10(-5) to 0.001) of total prepared active ingredient. During application of kresoxim-methyl, the amount of dermal exposure was 17.5 mg (95% CI from 9.3 to 28.9), corresponding to 0.010% (95% CI from 0.006 to 0.017) of total applied active ingredient. The major exposure parts of the body were thighs and shins, with correlation coefficients of 0.53 and 0.43, respectively. The inhalation exposure during application were estimated as 6.8 ng (95% CI from 0.4 to 17.0), being 0.04% (95% CI from 0.004 to 0.06) of the dermal exposure. The calculated absorbable quantities of exposures for mixer/loader and applicator were 2.1 × 10(-4) mg/day (95% CI from 5.0 × 10(-6) to 7.2 × 10(-4)) and 2.3 mg/day (95% CI from 1.2 to 3.8), respectively. For risk assessment, the margin of safety of all working activities was much higher than 1, indicating that the possibility of risk to kresoxim-methyl was unlikely. PMID:26492351

  8. Probabilistic Exposure Assessment for Applicators during Treatment of the Fungicide Kresoxim-methyl on an Apple Orchard by a Speed Sprayer.

    PubMed

    Kim, Eunhye; Moon, Joon-Kwan; Choi, Hoon; Kim, Jeong-Han

    2015-12-01

    Probabilistic exposure and risk assessment of kresoxim-methyl were conducted for agricultural applicators during preparation of spray suspension and application with a speed sprayer on an apple orchard. The preparation and application of 1000 L of spray suspension were repeated 30 times. Several exposure matrices, including patches, cotton gloves, socks, masks, and XAD-2 resin, were used to measure the potential exposure for workers. The analytical methods were fully validated to guarantee the precision and accuracy of analysis. The exposure amount on hands for mixer/loader was 0.7 mg [95% confidence interval (CI) from 0.02 to 2.4], taking 0.0005% (95% CI from 1.2 × 10(-5) to 0.001) of total prepared active ingredient. During application of kresoxim-methyl, the amount of dermal exposure was 17.5 mg (95% CI from 9.3 to 28.9), corresponding to 0.010% (95% CI from 0.006 to 0.017) of total applied active ingredient. The major exposure parts of the body were thighs and shins, with correlation coefficients of 0.53 and 0.43, respectively. The inhalation exposure during application were estimated as 6.8 ng (95% CI from 0.4 to 17.0), being 0.04% (95% CI from 0.004 to 0.06) of the dermal exposure. The calculated absorbable quantities of exposures for mixer/loader and applicator were 2.1 × 10(-4) mg/day (95% CI from 5.0 × 10(-6) to 7.2 × 10(-4)) and 2.3 mg/day (95% CI from 1.2 to 3.8), respectively. For risk assessment, the margin of safety of all working activities was much higher than 1, indicating that the possibility of risk to kresoxim-methyl was unlikely.

  9. An Investigation of The Reticulated Foam - Perforated Steel Sheet Sandwich Structure As A Blast Mitigation Media

    NASA Astrophysics Data System (ADS)

    Nguyen, Thuy-Tien Ngoc; Proud, William; Institute of Shock Physics, Imperial College London Collaboration; Royal British Legion CentreBlast Injury Studies at Imperial College London Collaboration

    2015-06-01

    Explosions have always been the main cause of injuries during battles and conflicts, with improvised explosive devices (IEDs) becoming more and more common nowadays. In this paper, the interaction between blast waves and sandwich structures of reticulated foam and perforated sheets, with varying thickness and configuration, is studied using an air-driven shock tube apparatus. The mitigation effects for primary blast injuries of these structures are discussed in terms of pulse shape, pressure magnitude as well as shock impulse. Schlieren photography together with other high-speed imaging was also used to visually investigate the matter. The results show that lower open area of perforated sheet and increased thickness of foam offer best protection. However, below a threshold thickness, no mitigation is seen. The Institute of Shock Physics acknowledges the support of AWE, Aldermaston, UK and Imperial College London. The Centre for Blast Injury Studies acknowledges the support of the Royal British Legion and Imperial College London.

  10. Mixing Effect in Internal Blast

    NASA Astrophysics Data System (ADS)

    Granholm, R. H.; Sandusky, H. W.

    2009-12-01

    Detonation product gases are usually assumed to be completely mixed with an existing atmosphere by the time a peak quasi-static pressure (Pqs) is reached within an enclosed internal blast environment. With incomplete mixing, however, comes a loss in pressure from unburned fuel as well as a previously unrecognized source of error: heat capacity of the gas increases substantially with temperature, providing an energy sink in regions of unmixed hot gas. Our objective was to look at the extent of mixing by measuring gas temperature at several locations within a blast chamber at the time of peak Pqs. We recorded ranges of up to 400° C depending on charge location within the chamber, which is presumed to affect turbulence and mixing. Losses in peak Pqs of up to 13% may be attributed to this mixing effect for 1-kg Pentolite charges in a 62-m3 chamber in the simple geometries tested. A reasonably accurate Pqs may be extracted from blast wave reverberations in a chamber, allowing a closer look at effects such as gas mixing and consistency among multiple gages. These results point to an explanation for missing energy and a better understanding of heat flow in internal blast.

  11. Coal combustion under conditions of blast furnace injection; [Quarterly] technical report, September 1--November 30, 1993

    SciTech Connect

    Crelling, J.C.

    1993-12-31

    A potentially new use for Illinois coal is its use as a fuel injected into a blast furnace to produce molten iron as the first step in steel production. Because of its increasing cost and decreasing availability, metallurgical coke is now being replaced by coal injected at the tuyere area of the furnace where the blast air enters. The purpose of this study is to evaluate the combustion of coal during the blast furnace injection process and to delineate the optimum properties of the feed coal. This investigation is significant to the use of Illinois coal in that the limited research to date suggests that coals of low fluidity and moderate to high sulfur and chlorine contents are suitable feedstocks for blast furnace injection. This study is unique in that it will be the first North American effort to directly determine the nature of the combustion of coal injected into a blast furnace. This proposal is a follow-up to one funded for the 1992--1993 period. It is intended to complete the study already underway with the Armco Inc. steel company and to initiate a new cooperative study along somewhat similar lines with the Inland Steel Company. The results of this study will lead to the development of a testing and evaluation protocol that will give a unique and much needed understanding of the behavior of coal in the injection process and prove the potential of Illinois coals f or such use.

  12. Head and brain response to blast using sagittal and transverse finite element models.

    PubMed

    Singh, Dilaver; Cronin, Duane S; Haladuick, Tyler N

    2014-04-01

    Mild traumatic brain injury caused by blast exposure from Improvised Explosive Devices has become increasingly prevalent in modern conflicts. To investigate head kinematics and brain tissue response in blast scenarios, two solid hexahedral blast-head models were developed in the sagittal and transverse planes. The models were coupled to an Arbitrary Lagrangian-Eulerian model of the surrounding air to model blast-head interaction, for three blast load cases (5 kg C4 at 3, 3.5 and 4 m). The models were validated using experimental kinematic data, where predicted accelerations were in good agreement with experimental tests, and intracranial pressure traces at four locations in the brain, where the models provided good predictions for frontal, temporal and parietal, but underpredicted pressures at the occipital location. Brain tissue response was investigated for the wide range of constitutive properties available. The models predicted relatively low peak principal brain tissue strains from 0.035 to 0.087; however, strain rates ranged from 225 to 571 s-1. Importantly, these models have allowed us to quantify expected strains and strain rates experienced in brain tissue, which can be used to guide future material characterization. These computationally efficient and predictive models can be used to evaluate protection and mitigation strategies in future analysis.

  13. Modeling Coal Seam Damage in Cast Blasting

    SciTech Connect

    Chung, S.H.; Preece, D.S.

    1998-11-23

    A discrete element computer program named DMC_BLAST (Distinct Motion Code) has been under development since 1987 for modeling rock blasting (Preece & Taylor, 1989). This program employs explicit time integration and uses spherical or cylindrical elements that are represented as circles in two dimensions. DMC_BLAST calculations compare favorably with data from actual bench blasts (Preece et al, 1993). Coal seam chilling refers to the shattering of a significant portion of the coal leaving unusable fines. It is also refereed to as coal damage. Chilling is caused during a blast by a combination of explosive shock energy and movement of the adjacent rock. Chilling can be minimized by leaving a buffer zone between the bottom of the blastholes and the coal seam or by changing the blast design to decrease the powder factor or by a combination of both. Blast design in coal mine cast blasting is usually a compromise between coal damage and rock fragmentation and movement (heave). In this paper the damage to coal seams from rock movement is examined using the discrete element computer code DMC_BLAST. A rock material strength option has been incorporated into DMC_BLAST by placing bonds/links between the spherical particles used to model the rock. These bonds tie the particles together but can be broken when the tensile, compressive or shear stress in the bond exceeds the defined strength. This capability has been applied to predict coal seam damage, particularly at the toe of a cast blast where drag forces exerted by movement of the overlying rock can adversely effect the top of the coal at the bench face. A simulation of coal mine cast blasting has been performed with special attention being paid to the strength of the coal and its behavior at t he bench face during movement of the overlying material.

  14. The pathology of primary blast overpressure injury.

    PubMed

    Mayorga, M A

    1997-07-25

    Primary blast injury occurs in civilian and military detonations and from the firing of weapon systems. The pathology of primary blast injury has been reported for the last 70 years and has primarily been limited to descriptions of gross pathology and histology. Commonly accepted tenets have not been confirmed as blast overpressure experiments in enclosures and with multiple detonations have been conducted. Organ systems other than the ear and the lung are playing a greater role in injury definition and research importance. This paper is an overview and update of the current understanding of the pathology of primary blast injury.

  15. Air monitoring of aromatic hydrocarbons during automobile spray painting for developing change schedule of respirator cartridges

    PubMed Central

    2014-01-01

    In the absence of End of Service Life Indicator (ESLI), a cartridge change schedule should be established for ensuring that cartridges are changed before their end of service life. Factors effecting service life of cartridges were evaluated, including the amount of atmospheric contamination with aromatic hydrocarbon vapors in the workplace, temperature, and relative humidity of the air. A new change schedule was established based on comparing the results of air monitoring and workplace conditions, laboratory experiment, and the NIOSH MultiVapor software. Spray painters were being exposed to aromatic hydrocarbons in a range exceeding occupational exposure limits. The cartridge change schedule was not effective and could no longer provide adequate protection against organic contaminants for sprayers. Change schedules for respirator cartridges should be reduced from 16–24 hours to 4 hours. NIOSH’s service life software program could be applied to developing cartridge change schedules. PMID:24468234

  16. ScalaBLAST 2.0: Rapid and robust BLAST calculations on multiprocessor systems

    SciTech Connect

    Oehmen, Christopher S.; Baxter, Douglas J.

    2013-03-15

    BLAST remains one of the most widely used tools in computational biology. The rate at which new sequence data is available continues to grow exponentially, driving the emergence of new fields of biological research. At the same time multicore systems and conventional clusters are more accessible. ScalaBLAST has been designed to run on conventional multiprocessor systems with an eye to extreme parallelism, enabling parallel BLAST calculations using over 16,000 processing cores with a portable, robust, fault-resilient design. ScalaBLAST 2.0 source code can be freely downloaded from http://omics.pnl.gov/software/ScalaBLAST.php.

  17. Mechanics of blast loading on the head models in the study of traumatic brain injury using experimental and computational approaches.

    PubMed

    Ganpule, S; Alai, A; Plougonven, E; Chandra, N

    2013-06-01

    Blast waves generated by improvised explosive devices can cause mild, moderate to severe traumatic brain injury in soldiers and civilians. To understand the interactions of blast waves on the head and brain and to identify the mechanisms of injury, compression-driven air shock tubes are extensively used in laboratory settings to simulate the field conditions. The overall goal of this effort is to understand the mechanics of blast wave-head interactions as the blast wave traverses the head/brain continuum. Toward this goal, surrogate head model is subjected to well-controlled blast wave profile in the shock tube environment, and the results are analyzed using combined experimental and numerical approaches. The validated numerical models are then used to investigate the spatiotemporal distribution of stresses and pressure in the human skull and brain. By detailing the results from a series of careful experiments and numerical simulations, this paper demonstrates that: (1) Geometry of the head governs the flow dynamics around the head which in turn determines the net mechanical load on the head. (2) Biomechanical loading of the brain is governed by direct wave transmission, structural deformations, and wave reflections from tissue-material interfaces. (3) Deformation and stress analysis of the skull and brain show that skull flexure and tissue cavitation are possible mechanisms of blast-induced traumatic brain injury.

  18. Mechanics of blast loading on the head models in the study of traumatic brain injury using experimental and computational approaches.

    PubMed

    Ganpule, S; Alai, A; Plougonven, E; Chandra, N

    2013-06-01

    Blast waves generated by improvised explosive devices can cause mild, moderate to severe traumatic brain injury in soldiers and civilians. To understand the interactions of blast waves on the head and brain and to identify the mechanisms of injury, compression-driven air shock tubes are extensively used in laboratory settings to simulate the field conditions. The overall goal of this effort is to understand the mechanics of blast wave-head interactions as the blast wave traverses the head/brain continuum. Toward this goal, surrogate head model is subjected to well-controlled blast wave profile in the shock tube environment, and the results are analyzed using combined experimental and numerical approaches. The validated numerical models are then used to investigate the spatiotemporal distribution of stresses and pressure in the human skull and brain. By detailing the results from a series of careful experiments and numerical simulations, this paper demonstrates that: (1) Geometry of the head governs the flow dynamics around the head which in turn determines the net mechanical load on the head. (2) Biomechanical loading of the brain is governed by direct wave transmission, structural deformations, and wave reflections from tissue-material interfaces. (3) Deformation and stress analysis of the skull and brain show that skull flexure and tissue cavitation are possible mechanisms of blast-induced traumatic brain injury. PMID:22832705

  19. Physics of IED Blast Shock Tube Simulations for mTBI Research

    PubMed Central

    Mediavilla Varas, Jesus; Philippens, M.; Meijer, S. R.; van den Berg, A. C.; Sibma, P. C.; van Bree, J. L. M. J.; de Vries, D. V. W. M.

    2011-01-01

    Shock tube experiments and simulations are conducted with a spherical gelatin filled skull–brain surrogate, in order to study the mechanisms leading to blast induced mild traumatic brain injury. A shock tube including sensor system is optimized to simulate realistic improvised explosive device blast profiles obtained from full scale field tests. The response of the skull–brain surrogate is monitored using pressure and strain measurements. Fluid–structure interaction is modeled using a combination of computational fluid dynamics (CFD) simulations for the air blast, and a finite element model for the structural response. The results help to understand the physics of wave propagation, from air blast into the skull–brain. The presence of openings on the skull and its orientation does have a strong effect on the internal pressure. A parameter study reveals that when there is an opening in the skull, the skull gives little protection and the internal pressure is fairly independent on the skull stiffness; the gelatin shear stiffness has little effect on the internal pressure. Simulations show that the presence of pressure sensors in the gelatin hardly disturbs the pressure field. PMID:21960984

  20. Numerical Simulation for Blast Analysis of Insulating Glass in a Curtain Wall

    NASA Astrophysics Data System (ADS)

    Deng, Rong-bing; Jin, Xian-long

    2010-04-01

    This article presents a three-dimensional numerical simulation method for blast response calculation of insulating glass in a curtain wall based on multi-material arbitrary Lagrangian-Eulerian (ALE) formulation and high-performance computer. The whole analytical model consists of explosion, air, curtain wall system, and ground. In particular, detailed components including insulating glass panels, aluminum column, silicone sealant, and other parts in the curtain wall are set up in terms of actual size and actual assembly. This model takes account of the coupling between blast and structure, nonlinear material behavior, brittle failure of glass material, and non-reflecting boundary definition. Final calculation has been performed on the Dawning 4000A supercomputer using the finite-element code LS-DYNA 971 MPP. The propagation of shock wave in air and blast-structure interaction is quite well estimated by numerical calculation. The damage regions of outer and inner glass are reproduced in the numerical simulations, which are in agreement with the experimental observations. The result provides a global understanding of insulating glass panels under blast loading in the curtain wall system. It may be generated to supplement experimental studies for developing appropriate design guidelines for curtain wall systems as well.

  1. 30 CFR 77.1300 - Explosives and blasting.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Explosives and blasting. 77.1300 Section 77... Explosives and Blasting § 77.1300 Explosives and blasting. (a) No explosives, blasting agent, detonator, or... accordance with the provisions of §§ 77.1301 through 77.1304, inclusive. (b) The term “explosives” as used...

  2. 30 CFR 77.1300 - Explosives and blasting.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Explosives and blasting. 77.1300 Section 77... Explosives and Blasting § 77.1300 Explosives and blasting. (a) No explosives, blasting agent, detonator, or... accordance with the provisions of §§ 77.1301 through 77.1304, inclusive. (b) The term “explosives” as used...

  3. 30 CFR 77.1300 - Explosives and blasting.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Explosives and blasting. 77.1300 Section 77... Explosives and Blasting § 77.1300 Explosives and blasting. (a) No explosives, blasting agent, detonator, or... accordance with the provisions of §§ 77.1301 through 77.1304, inclusive. (b) The term “explosives” as used...

  4. 30 CFR 77.1300 - Explosives and blasting.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Explosives and blasting. 77.1300 Section 77... Explosives and Blasting § 77.1300 Explosives and blasting. (a) No explosives, blasting agent, detonator, or... accordance with the provisions of §§ 77.1301 through 77.1304, inclusive. (b) The term “explosives” as used...

  5. 30 CFR 77.1300 - Explosives and blasting.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Explosives and blasting. 77.1300 Section 77... Explosives and Blasting § 77.1300 Explosives and blasting. (a) No explosives, blasting agent, detonator, or... accordance with the provisions of §§ 77.1301 through 77.1304, inclusive. (b) The term “explosives” as used...

  6. 29 CFR 1926.909 - Firing the blast.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 8 2011-07-01 2011-07-01 false Firing the blast. 1926.909 Section 1926.909 Labor... Firing the blast. (a) A code of blasting signals equivalent to Table U-1, shall be posted on one or more... code and conform to it. Danger signs shall be placed at suitable locations. (b) Before a blast is...

  7. 29 CFR 1926.909 - Firing the blast.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 8 2014-07-01 2014-07-01 false Firing the blast. 1926.909 Section 1926.909 Labor... Firing the blast. (a) A code of blasting signals equivalent to Table U-1, shall be posted on one or more... code and conform to it. Danger signs shall be placed at suitable locations. (b) Before a blast is...

  8. 29 CFR 1926.909 - Firing the blast.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false Firing the blast. 1926.909 Section 1926.909 Labor... Firing the blast. (a) A code of blasting signals equivalent to Table U-1, shall be posted on one or more... code and conform to it. Danger signs shall be placed at suitable locations. (b) Before a blast is...

  9. 29 CFR 1926.909 - Firing the blast.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 8 2012-07-01 2012-07-01 false Firing the blast. 1926.909 Section 1926.909 Labor... Firing the blast. (a) A code of blasting signals equivalent to Table U-1, shall be posted on one or more... code and conform to it. Danger signs shall be placed at suitable locations. (b) Before a blast is...

  10. 29 CFR 1926.909 - Firing the blast.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 8 2013-07-01 2013-07-01 false Firing the blast. 1926.909 Section 1926.909 Labor... Firing the blast. (a) A code of blasting signals equivalent to Table U-1, shall be posted on one or more... code and conform to it. Danger signs shall be placed at suitable locations. (b) Before a blast is...

  11. 30 CFR 780.13 - Operation plan: Blasting.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Operation plan: Blasting. 780.13 Section 780.13... SURFACE MINING PERMIT APPLICATIONS-MINIMUM REQUIREMENTS FOR RECLAMATION AND OPERATION PLAN § 780.13 Operation plan: Blasting. (a) Blasting plan. Each application shall contain a blasting plan for the...

  12. 30 CFR 780.13 - Operation plan: Blasting.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Operation plan: Blasting. 780.13 Section 780.13... SURFACE MINING PERMIT APPLICATIONS-MINIMUM REQUIREMENTS FOR RECLAMATION AND OPERATION PLAN § 780.13 Operation plan: Blasting. (a) Blasting plan. Each application shall contain a blasting plan for the...

  13. In-situ rock strength determination for blasting purposes

    SciTech Connect

    Soni, D.K.; Jain, A.

    1994-12-31

    Compressive strength of rocks is often required by mining engineers and quarrying authorities for blasting operations. Uniaxial compressive strength of rocks can be predicted with reasonable accuracy with the help of point load strength tests which can be easily conducted at site by the field staff, simultaneously as the cores are recovered from drilling operations. A number of diametral point load tests and uniaxial compressive strength tests have been conducted on the specimens of different rock types under air dried, and saturated condition as well to study the effect of ground water saturation on strength. It has been observed that due to saturation uniaxial compressive strength and point load strength get reduced to a maximum of 32 and 29 percent respectively. It has also been observed that uniaxial strength is sixteen times the point load strength in air dried as well as saturated condition. However, this factor used for calculating uniaxial compressive strength may be reduced to a lower value for the safety of miners in field blasting operations.

  14. Non-explosive blast injury of the ear.

    PubMed

    Berger, G; Finkelstein, Y; Harell, M

    1994-05-01

    Non-explosive blast injury of the ear refers to the otological trauma caused by a blow to the ear that seals the external auditory meatus. It results in a sudden increase of air pressure within the ear canal that strikes the tympanic membrane. The present study portrays the various aspects of middle and inner ear damage in 91 patients resulting from an assault we entitled a 'non-explosive blast injury' to the ear. Sixty cases were caused by a slap or a fist, 13 patients suffered sport accidents, mostly in ball games, and 18 patients were injured during swimming and water sports activities. The common symptoms were hearing loss, earache, tinnitus, vertigo and otorrhoea. All 91 patients presented with acute perforations of their eardrums. The mean conductive hearing loss was 11.2 dB. A high tone sensorineural hearing loss was detected in only 20 per cent of the patients. A spontaneous closure of the perforation with a conservative management approach was observed in 94.8 per cent of the patients. Healing of the perforation was always associated with closure of the air-bone gap, while the results of the sensorineural hearing loss recovery were less favourable.

  15. Rebuilding of Rautaruukki blast furnaces

    SciTech Connect

    Kallo, S.; Pisilae, E.; Ojala, K.

    1997-12-31

    Rautaruukki Oy Raahe Steel rebuilt its blast furnaces in 1995 (BF1) and 1996 (BF2) after 10 year campaigns and production of 9,747 THM/m{sup 3} (303 NTHM/ft{sup 3}) and 9,535 THM/m{sup 3} (297 NTHM/ft{sup 3}), respectively. At the end of the campaigns, damaged cooling system and shell cracks were increasingly disturbing the availability of furnaces. The goal for rebuilding was to improve the cooling systems and refractory quality in order to attain a 15 year campaign. The furnaces were slightly enlarged to meet the future production demand. The blast furnace control rooms and operations were centralized and the automation and instrumentation level was considerably improved in order to improve the operation efficiency and to reduce manpower requirements. Investments in direct slag granulation and improved casthouse dedusting improved environmental protection. The paper describes the rebuilding.

  16. Background to plastic media blasting

    NASA Astrophysics Data System (ADS)

    Foster, Terry

    1995-04-01

    Chemical strippers based on active phenolic components in a chlorinated solvent have been the traditional method for removing of paints and coatings from aircraft. With the recent recognition of the environmental and health concerns of chlorinated solvents and the problem disposing of phenols there have been some major developments in paint removal technology. One of the first techniques developed to replace chemical strippers and now one of the most widely used techniques for paint removal from aircraft was plastic media blasting (PMB). The PMB technique is similar to traditional grit blasting (slag, sand alumina or carborundum) techniques used on steel and other metals (based on grits) but using polymer based media that are softer and less aggressive. Plastic media are ranked by hardness and density as well as chemical composition.

  17. HIGH PRODUCTIVITY VACUUM BLASTING SYSTEM

    SciTech Connect

    William S. McPhee

    2001-08-31

    The Department of Energy (DOE) needs improved technologies to decontaminate large areas of both concrete and steel surfaces. The technology should have high operational efficiency, minimize exposures to workers, and produce low levels of secondary waste. In order to meet the DOE's needs, an applied research and development project for the improvement of a current decontamination technology, Vacuum Blasting, is proposed. The objective of this project is to improve the productivity and lower the expense of the existing vacuum blasting technology which has been widely used in DOE sites for removing radioactive contamination, PCBs, and lead-based paint. The proposed work would increase the productivity rate and provide safe and cost-effective decontamination of the DOE sites.

  18. On the Propagation and Interaction of Spherical Blast Waves

    NASA Technical Reports Server (NTRS)

    Kandula, Max; Freeman, Robert

    2007-01-01

    The characteristics and the scaling laws of isolated spherical blast waves have been briefly reviewed. Both self-similar solutions and numerical solutions of isolated blast waves are discussed. Blast profiles in the near-field (strong shock region) and the far-field (weak shock region) are examined. Particular attention is directed at the blast overpressure and shock propagating speed. Consideration is also given to the interaction of spherical blast waves. Test data for the propagation and interaction of spherical blast waves emanating from explosives placed in the vicinity of a solid propellant stack are presented. These data are discussed with regard to the scaling laws concerning the decay of blast overpressure.

  19. Laboratory blast wave driven instabilities

    NASA Astrophysics Data System (ADS)

    Kuranz, Carolyn

    2008-11-01

    This presentation discusses experiments involving the evolution of hydrodynamic instabilities in the laboratory under high-energy-density (HED) conditions. These instabilities are driven by blast waves, which occur following a sudden, finite release of energy, and consist of a shock front followed by a rarefaction wave. When a blast wave crosses an interface with a decrease in density, hydrodynamic instabilities will develop. Instabilities evolving under HED conditions are relevant to astrophysics. These experiments include target materials scaled in density to the He/H layer in SN1987A. About 5 kJ of laser energy from the Omega Laser facility irradiates a 150 μm plastic layer that is followed by a low-density foam layer. A blast wave structure similar to those in supernovae is created in the plastic layer. The blast wave crosses an interface having a 2D or 3D sinusoidal structure that serves as a seed perturbation for hydrodynamic instabilities. This produces unstable growth dominated by the Rayleigh-Taylor (RT) instability in the nonlinear regime. We have detected the interface structure under these conditions using x-ray backlighting. Recent advances in our diagnostic techniques have greatly improved the resolution of our x-ray radiographic images. Under certain conditions, the improved images show some mass extending beyond the RT spike and penetrating further than previously observed or predicted by current simulations. The observed effect is potentially of great importance as a source of mass transport to places not anticipated by current theory and simulation. I will discuss the amount of mass in these spike extensions, the associated uncertainties, and hypotheses regarding their origin We also plan to show comparisons of experiments using single mode and multimode as well as 2D and 3D initial conditions. This work is sponsored by DOE/NNSA Research Grants DE-FG52-07NA28058 (Stewardship Sciences Academic Alliances) and DE-FG52-04NA00064 (National Laser User

  20. 27 CFR 555.220 - Table of separation distances of ammonium nitrate and blasting agents from explosives or blasting...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    .... Department of Transportation (49 CFR part 173). (5) Earth or sand dikes, or enclosures filled with the... distances of ammonium nitrate and blasting agents from explosives or blasting agents. 555.220 Section 555... ammonium nitrate and blasting agents from explosives or blasting agents. Table: Department of...

  1. 27 CFR 555.220 - Table of separation distances of ammonium nitrate and blasting agents from explosives or blasting...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    .... Department of Transportation (49 CFR part 173). (5) Earth or sand dikes, or enclosures filled with the... distances of ammonium nitrate and blasting agents from explosives or blasting agents. 555.220 Section 555... ammonium nitrate and blasting agents from explosives or blasting agents. Table: Department of...

  2. 27 CFR 555.220 - Table of separation distances of ammonium nitrate and blasting agents from explosives or blasting...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    .... Department of Transportation (49 CFR part 173). (5) Earth or sand dikes, or enclosures filled with the... distances of ammonium nitrate and blasting agents from explosives or blasting agents. 555.220 Section 555... ammonium nitrate and blasting agents from explosives or blasting agents. Table: Department of...

  3. 27 CFR 555.220 - Table of separation distances of ammonium nitrate and blasting agents from explosives or blasting...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    .... Department of Transportation (49 CFR part 173). (5) Earth or sand dikes, or enclosures filled with the... distances of ammonium nitrate and blasting agents from explosives or blasting agents. 555.220 Section 555... ammonium nitrate and blasting agents from explosives or blasting agents. Table: Department of...

  4. 27 CFR 555.220 - Table of separation distances of ammonium nitrate and blasting agents from explosives or blasting...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    .... Department of Transportation (49 CFR part 173). (5) Earth or sand dikes, or enclosures filled with the... distances of ammonium nitrate and blasting agents from explosives or blasting agents. 555.220 Section 555... ammonium nitrate and blasting agents from explosives or blasting agents. Table: Department of...

  5. Open pit blasting in India

    SciTech Connect

    Wasson, D.A.; Garg, D.D.

    1995-12-31

    Open pit blasting in India uses two types of explosives. First there are bulk explosives for wet and dry holes, and there are packaged explosives. The Indian open pit coal mining is projected to use 190 thousand metric tons of explosives in 1995. This volume is projected to grow for the next ten years, whereas the underground coal mining will hold fairly constant. Bulk explosives started in about 1977 with watergels. In the late 1980s, bulk emulsions and heavy ANFOs were introduced. This system is still being expanded and is replacing packaged products in the larger mines. Packaged products are still popular where the annual consumption is less than 2,000 metric tons per year. Also, packaged products are used in small wet shots. Porous ammonium nitrate prill have recently become available but ANFO is not very common because of the high cost of the prill and the wet blasting conditions. As the market expands there will be a continuing demand for packaged products but an increasing demand for bulk waterproof products, particularly in the larger operations. Dynamites are produced at four plants in India. The annual production of about 45,000 metric tons per year is holding fairly constant, but is likely to decrease in the future. The future blasting in India will primarily use pumped emulsions and heavy ANFO on an increasing basis, but the packaged products will maintain their position.

  6. Controlled-Temperature Hot-Air Gun

    NASA Technical Reports Server (NTRS)

    Munoz, M. C.

    1986-01-01

    Materials that find applications in wind tunnels first tested in laboratory. Hot-Air Gun differs from commercial units in that flow rate and temperature monitored and controlled. With typical compressed-airsupply pressure of 25 to 38 psi (170 to 260 kPa), flow rate and maximum temperature are 34 stdft3/min (0.96 stdm3/min) and 1,090 degrees F (590 degrees C), respectively. Resembling elaborate but carefully regulated hot-air gun, setup used to apply blasts of air temperatures above 1,500 degrees F (815 degrees C) to test specimens.

  7. 7 CFR 3201.78 - Blast media.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... purchasing programs. The designation can be found in the Comprehensive Procurement Guideline, 40 CFR 247.17. ... 7 Agriculture 15 2013-01-01 2013-01-01 false Blast media. 3201.78 Section 3201.78 Agriculture... Items § 3201.78 Blast media. (a) Definition. Abrasive particles sprayed forcefully to clean,...

  8. 7 CFR 3201.78 - Blast media.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... purchasing programs. The designation can be found in the Comprehensive Procurement Guideline, 40 CFR 247.17. ... 7 Agriculture 15 2014-01-01 2014-01-01 false Blast media. 3201.78 Section 3201.78 Agriculture... Items § 3201.78 Blast media. (a) Definition. Abrasive particles sprayed forcefully to clean,...

  9. Color changing photonic crystals detect blast exposure.

    PubMed

    Cullen, D Kacy; Xu, Yongan; Reneer, Dexter V; Browne, Kevin D; Geddes, James W; Yang, Shu; Smith, Douglas H

    2011-01-01

    Blast-induced traumatic brain injury (bTBI) is the "signature wound" of the current wars in Iraq and Afghanistan. However, with no objective information of relative blast exposure, warfighters with bTBI may not receive appropriate medical care and are at risk of being returned to the battlefield. Accordingly, we have created a colorimetric blast injury dosimeter (BID) that exploits material failure of photonic crystals to detect blast exposure. Appearing like a colored sticker, the BID is fabricated in photosensitive polymers via multi-beam interference lithography. Although very stable in the presence of heat, cold or physical impact, sculpted micro- and nano-structures of the BID are physically altered in a precise manner by blast exposure, resulting in color changes that correspond with blast intensity. This approach offers a lightweight, power-free sensor that can be readily interpreted by the naked eye. Importantly, with future refinement this technology may be deployed to identify soldiers exposed to blast at levels suggested to be supra-threshold for non-impact blast-induced mild TBI.

  10. Existing and prospective blast-furnace conditions

    SciTech Connect

    I.G. Tovarovskii; V.I. Bol'shakov; V.P. Lyalyuk; A.E. Merkulov; D. V. Pinchuk

    2009-07-15

    Blast-furnace conditions are investigated by means of a multizone model. The expected performance of prospective technologies is assessed, as well as the trends in blast-furnace processes. The model permits the identification of means of overcoming practical difficulties.

  11. Color changing photonic crystals detect blast exposure

    PubMed Central

    Cullen, D. Kacy; Xu, Yongan; Reneer, Dexter V.; Browne, Kevin D.; Geddes, James W.; Yang, Shu; Smith, Douglas H.

    2010-01-01

    Blast-induced traumatic brain injury (bTBI) is the “signature wound” of the current wars in Iraq and Afghanistan. However, with no objective information of relative blast exposure, warfighters with bTBI may not receive appropriate medical care and are at risk of being returned to the battlefield. Accordingly, we have created a colorimetric blast injury dosimeter (BID) that exploits material failure of photonic crystals to detect blast exposure. Appearing like a colored sticker, the BID is fabricated in photosensitive polymers via multi-beam interference lithography. Although very stable in the presence of heat, cold or physical impact, sculpted micro- and nano-structures of the BID are physically altered in a precise manner by blast exposure, resulting in color changes that correspond with blast intensity. This approach offers a lightweight, power-free sensor that can be readily interpreted by the naked eye. Importantly, with future refinement this technology may be deployed to identify soldiers exposed to blast at levels suggested to be supra-threshold for non-impact blast-induced mild TBI. PMID:21040795

  12. Highly concentrated foam formulation for blast mitigation

    DOEpatents

    Tucker, Mark D.; Gao, Huizhen

    2010-12-14

    A highly concentrated foam formulation for blast suppression and dispersion mitigation for use in responding to a terrorism incident involving a radiological dispersion device. The foam formulation is more concentrated and more stable than the current blast suppression foam (AFC-380), which reduces the logistics burden on the user.

  13. 30 CFR 57.6803 - Blasting lines.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Explosives Maintenance-Surface and Underground § 57.6803 Blasting lines. Permanent blasting lines shall be properly supported....

  14. Back yard blasting on the quiet

    SciTech Connect

    Chironis, N.P.

    1983-06-01

    When R and F Coal Company of Ohio ''sweeps out the corners'' of many of its old sites, it often blasts ''literally in some family's back yard.'' Sequential blasting patterns allow for such work without unduly disturbing the residents. Four basic delay patterns are detailed in this article. Sequential timers, EB caps, HDP blast boosts, and bulk ANFO are used in the sequences. Electric blasting caps can be tested by means of a galvanometer for continuity and resistance whenever possible. The flexibility of programming firing times, in the four patterns, allows operators to fine tune the blasting techniques. End or back break are reduced, fragmentation is optimized, and vibration is held to a minimum.

  15. Coal combustion under conditions of blast furnace injection. Technical report, March 1, 1994--May 31, 1994

    SciTech Connect

    Crelling, J.C.

    1994-09-01

    A potentially new use for Illinois coal is its use as a fuel injected into a blast furnace to produce molten iron as the first step in steel production. Because of its increasing cost and decreasing availability, metallurgical coke is now being replaced by coal injected at the tuyere area of the furnace where the blast air enters. The purpose of this study is to evaluate the combustion of coal during the blast furnace injection process and to delineate the optimum properties of the feed coal. This investigation is significant to the use of Illinois coal in that the limited research to date suggests that coals of low fluidity and moderate to high sulfur and chlorine contents are suitable feedstocks for blast furnace injection. This proposal is a follow-up to one funded for the 1992-93 period. It is intended to complete the study already underway with the Armco Inc. Steel Company and to initiate a new cooperative study along somewhat similar lines with the Inland Steel Company. The results of this study will lead to the development of a testing and evaluation protocol that will give a unique and much needed understanding of the behavior of coal in the injection process and prove the potential of Illinois coals for such use. During this quarter samples of two feed coals and the IBCSP 112 (Herrin No. 6) were prepared for reactivity testing and compared to blast furnace coke, and char fines taken from an active blast furnace. As the initial part of a broad reactivity analysis program, these same samples were also analyzed on a thermogravimetric analyzer (TGA) to determine their combustion and reactivity properties.

  16. A mouse model of ocular blast injury that induces closed globe anterior and posterior pole damage.

    PubMed

    Hines-Beard, Jessica; Marchetta, Jeffrey; Gordon, Sarah; Chaum, Edward; Geisert, Eldon E; Rex, Tonia S

    2012-06-01

    We developed and characterized a mouse model of primary ocular blast injury. The device consists of: a pressurized air tank attached to a regulated paintball gun with a machined barrel; a chamber that protects the mouse from direct injury and recoil, while exposing the eye; and a secure platform that enables fine, controlled movement of the chamber in relation to the barrel. Expected pressures were calculated and the optimal pressure transducer, based on the predicted pressures, was positioned to measure output pressures at the location where the mouse eye would be placed. Mice were exposed to one of three blast pressures (23.6, 26.4, or 30.4 psi). Gross pathology, intraocular pressure, optical coherence tomography, and visual acuity were assessed 0, 3, 7, 14, and 28 days after exposure. Contralateral eyes and non-blast exposed mice were used as controls. We detected increased damage with increased pressures and a shift in the damage profile over time. Gross pathology included corneal edema, corneal abrasions, and optic nerve avulsion. Retinal damage was detected by optical coherence tomography and a deficit in visual acuity was detected by optokinetics. Our findings are comparable to those identified in Veterans of the recent wars with closed eye injuries as a result of blast exposure. In summary, this is a relatively simple system that creates injuries with features similar to those seen in patients with ocular blast trauma. This is an important new model for testing the short-term and long-term spectrum of closed globe blast injuries and potential therapeutic interventions.

  17. Chronic traumatic encephalopathy in blast-exposed military veterans and a blast neurotrauma mouse model.

    PubMed

    Goldstein, Lee E; Fisher, Andrew M; Tagge, Chad A; Zhang, Xiao-Lei; Velisek, Libor; Sullivan, John A; Upreti, Chirag; Kracht, Jonathan M; Ericsson, Maria; Wojnarowicz, Mark W; Goletiani, Cezar J; Maglakelidze, Giorgi M; Casey, Noel; Moncaster, Juliet A; Minaeva, Olga; Moir, Robert D; Nowinski, Christopher J; Stern, Robert A; Cantu, Robert C; Geiling, James; Blusztajn, Jan K; Wolozin, Benjamin L; Ikezu, Tsuneya; Stein, Thor D; Budson, Andrew E; Kowall, Neil W; Chargin, David; Sharon, Andre; Saman, Sudad; Hall, Garth F; Moss, William C; Cleveland, Robin O; Tanzi, Rudolph E; Stanton, Patric K; McKee, Ann C

    2012-05-16

    Blast exposure is associated with traumatic brain injury (TBI), neuropsychiatric symptoms, and long-term cognitive disability. We examined a case series of postmortem brains from U.S. military veterans exposed to blast and/or concussive injury. We found evidence of chronic traumatic encephalopathy (CTE), a tau protein-linked neurodegenerative disease, that was similar to the CTE neuropathology observed in young amateur American football players and a professional wrestler with histories of concussive injuries. We developed a blast neurotrauma mouse model that recapitulated CTE-linked neuropathology in wild-type C57BL/6 mice 2 weeks after exposure to a single blast. Blast-exposed mice demonstrated phosphorylated tauopathy, myelinated axonopathy, microvasculopathy, chronic neuroinflammation, and neurodegeneration in the absence of macroscopic tissue damage or hemorrhage. Blast exposure induced persistent hippocampal-dependent learning and memory deficits that persisted for at least 1 month and correlated with impaired axonal conduction and defective activity-dependent long-term potentiation of synaptic transmission. Intracerebral pressure recordings demonstrated that shock waves traversed the mouse brain with minimal change and without thoracic contributions. Kinematic analysis revealed blast-induced head oscillation at accelerations sufficient to cause brain injury. Head immobilization during blast exposure prevented blast-induced learning and memory deficits. The contribution of blast wind to injurious head acceleration may be a primary injury mechanism leading to blast-related TBI and CTE. These results identify common pathogenic determinants leading to CTE in blast-exposed military veterans and head-injured athletes and additionally provide mechanistic evidence linking blast exposure to persistent impairments in neurophysiological function, learning, and memory.

  18. Chronic traumatic encephalopathy in blast-exposed military veterans and a blast neurotrauma mouse model.

    PubMed

    Goldstein, Lee E; Fisher, Andrew M; Tagge, Chad A; Zhang, Xiao-Lei; Velisek, Libor; Sullivan, John A; Upreti, Chirag; Kracht, Jonathan M; Ericsson, Maria; Wojnarowicz, Mark W; Goletiani, Cezar J; Maglakelidze, Giorgi M; Casey, Noel; Moncaster, Juliet A; Minaeva, Olga; Moir, Robert D; Nowinski, Christopher J; Stern, Robert A; Cantu, Robert C; Geiling, James; Blusztajn, Jan K; Wolozin, Benjamin L; Ikezu, Tsuneya; Stein, Thor D; Budson, Andrew E; Kowall, Neil W; Chargin, David; Sharon, Andre; Saman, Sudad; Hall, Garth F; Moss, William C; Cleveland, Robin O; Tanzi, Rudolph E; Stanton, Patric K; McKee, Ann C

    2012-05-16

    Blast exposure is associated with traumatic brain injury (TBI), neuropsychiatric symptoms, and long-term cognitive disability. We examined a case series of postmortem brains from U.S. military veterans exposed to blast and/or concussive injury. We found evidence of chronic traumatic encephalopathy (CTE), a tau protein-linked neurodegenerative disease, that was similar to the CTE neuropathology observed in young amateur American football players and a professional wrestler with histories of concussive injuries. We developed a blast neurotrauma mouse model that recapitulated CTE-linked neuropathology in wild-type C57BL/6 mice 2 weeks after exposure to a single blast. Blast-exposed mice demonstrated phosphorylated tauopathy, myelinated axonopathy, microvasculopathy, chronic neuroinflammation, and neurodegeneration in the absence of macroscopic tissue damage or hemorrhage. Blast exposure induced persistent hippocampal-dependent learning and memory deficits that persisted for at least 1 month and correlated with impaired axonal conduction and defective activity-dependent long-term potentiation of synaptic transmission. Intracerebral pressure recordings demonstrated that shock waves traversed the mouse brain with minimal change and without thoracic contributions. Kinematic analysis revealed blast-induced head oscillation at accelerations sufficient to cause brain injury. Head immobilization during blast exposure prevented blast-induced learning and memory deficits. The contribution of blast wind to injurious head acceleration may be a primary injury mechanism leading to blast-related TBI and CTE. These results identify common pathogenic determinants leading to CTE in blast-exposed military veterans and head-injured athletes and additionally provide mechanistic evidence linking blast exposure to persistent impairments in neurophysiological function, learning, and memory. PMID:22593173

  19. Chronic Traumatic Encephalopathy in Blast-Exposed Military Veterans and a Blast Neurotrauma Mouse Model

    PubMed Central

    Goldstein, Lee E.; Fisher, Andrew M.; Tagge, Chad A.; Zhang, Xiao-Lei; Velisek, Libor; Sullivan, John A.; Upreti, Chirag; Kracht, Jonathan M.; Ericsson, Maria; Wojnarowicz, Mark W.; Goletiani, Cezar J.; Maglakelidze, Giorgi M.; Casey, Noel; Moncaster, Juliet A.; Minaeva, Olga; Moir, Robert D.; Nowinski, Christopher J.; Stern, Robert A.; Cantu, Robert C.; Geiling, James; Blusztajn, Jan K.; Wolozin, Benjamin L.; Ikezu, Tsuneya; Stein, Thor D.; Budson, Andrew E.; Kowall, Neil W.; Chargin, David; Sharon, Andre; Saman, Sudad; Hall, Garth F.; Moss, William C.; Cleveland, Robin O.; Tanzi, Rudolph E.; Stanton, Patric K.; McKee, Ann C.

    2013-01-01

    Blast exposure is associated with traumatic brain injury (TBI), neuropsychiatric symptoms, and long-term cognitive disability. We examined a case series of postmortem brains from U.S. military veterans exposed to blast and/or concussive injury. We found evidence of chronic traumatic encephalopathy (CTE), a tau protein–linked neurodegenerative disease, that was similar to the CTE neuropathology observed in young amateur American football players and a professional wrestler with histories of concussive injuries. We developed a blast neurotrauma mouse model that recapitulated CTE-linked neuropathology in wild-type C57BL/6 mice 2 weeks after exposure to a single blast. Blast-exposed mice demonstrated phosphorylated tauopathy, myelinated axonopathy, microvasculopathy, chronic neuroinflammation, and neurodegeneration in the absence of macroscopic tissue damage or hemorrhage. Blast exposure induced persistent hippocampal-dependent learning and memory deficits that persisted for at least 1 month and correlated with impaired axonal conduction and defective activity-dependent long-term potentiation of synaptic transmission. Intracerebral pressure recordings demonstrated that shock waves traversed the mouse brain with minimal change and without thoracic contributions. Kinematic analysis revealed blast-induced head oscillation at accelerations sufficient to cause brain injury. Head immobilization during blast exposure prevented blast-induced learning and memory deficits. The contribution of blast wind to injurious head acceleration may be a primary injury mechanism leading to blast-related TBI and CTE. These results identify common pathogenic determinants leading to CTE in blast-exposed military veterans and head-injured athletes and additionally provide mechanistic evidence linking blast exposure to persistent impairments in neurophysiological function, learning, and memory. PMID:22593173

  20. Using Building Seismic Strong-Motion Data to Quantify Urban Blast Pressure Fields

    NASA Astrophysics Data System (ADS)

    Massari, A.; Kohler, M. D.; Heaton, T. H.; Kanamori, H.; Hauksson, E.; Clayton, R. W.; Guy, R.; Bunn, J.; Chandy, M.

    2015-12-01

    The use of building vibrations to measure blast wave propagation in a city is examined in this case study. The Exxon Mobil Corp. oil refinery in Torrance, California experienced an explosion on February 18, 2015 causing ground shaking equivalent to a magnitude 1.9 earthquake. The impulse response for the source was computed from Southern California Seismic Network data for a multi-orthogonal force system with a value of 2×105 kN vertically downward. The pressure wave excited by the explosion traveled through the city of Los Angeles, and was detected by a dense accelerometer array in a 52-story building also in downtown Los Angeles 22.8 km from the explosion. The array is part of the Community Seismic Network (CSN) and consists of three-component class-C MEMs sensors located on each floor of the building. The detection was verified by the nearly simultaneous arrival times of acceleration pulses on multiple floors of the building, corresponding to an average wave speed near the speed of sound in air. The pressure wave peak magnitude from the air blast was determined using accelerometer data collected on every floor of the building coupled with the elastic response of the structure as a whole. . Making use of high-fidelity finite element modeling of the building validated by previous low-level seismicity and ambient noise data, a procedure is outlined for pressure wave detection and quantification on well instrumented buildings. This case study for a 52 story building, instrumented by the CSN, acts as a proxy for blast wave quantification in dense urban environments. This type of information can be used to understand the flow of blast waves through a cityscape as well as enhance procedures for estimating blast source magnitude. Better understanding of the propagation of pressure waves in urban environments will lead to the development of improved countermeasures in those environments.

  1. Air Pollution

    MedlinePlus

    Air pollution is a mixture of solid particles and gases in the air. Car emissions, chemicals from factories, ... Ozone, a gas, is a major part of air pollution in cities. When ozone forms air pollution, it's ...

  2. Blast damage control during underground mining

    SciTech Connect

    Singh, S.P.

    1994-12-31

    Tracer blasting is commonly used in Canadian underground mines for overbreak control. It involves tracing a column of ANFO with a low strength detonating cord. In order to investigate the effectiveness of tracer blasting in perimeter control and to understand its mechanism, a field experimentation was conducted which involved drifting, benching and pipe tests. Initially, a comparison between tracer blasting and other explosive products was made on the basis of half cast factor and percentage overbreak. It was found that tracer blasting produced relatively much lower damage. The following observations were made during tracer blasting experiments: (a) reduction in ground vibrations; (b) partial deflagration and desensitization of ANFO; (c) reduction in the total available explosive energy; (d) continuous side initiation of ANFO column; (e) lateral VOD of ANFO was much less than the steady state VOD; (f) energy partitioning was more in favor of gas energy. It was observed that tracer blasting has the potential of being very cost effective and safer technique for overbreak control. A mechanism of tracer blasting has also been proposed in this paper.

  3. LTC vacuum blasting machine (concrete): Baseline report

    SciTech Connect

    1997-07-31

    The LTC shot blast technology was tested and is being evaluated at Florida International University (FIU) as a baseline technology. In conjunction with FIU`s evaluation of efficiency and cost, this report covers the evaluation conducted for safety and health issues. It is a commercially available technology and has been used for various projects at locations throughout the country. The LTC 1073 Vacuum Blasting Machine uses a high-capacity, direct-pressure blasting system which incorporates a continuous feed for the blast media. The blast media cleans the surface within the contained brush area of the blast. It incorporates a vacuum system which removes dust and debris from the surface as it is blasted. The safety and health evaluation during the testing demonstration focused on two main areas of exposure: dust and noise. Dust exposure during maintenance activities was minimal, but due to mechanical difficulties dust monitoring could not be conducted during operation. Noise exposure was significant. Further testing for each of these exposures is recommended because of the outdoor environment where the testing demonstration took place. This may cause the results to be inaccurate. It is feasible that the dust and noise levels will be higher in an enclosed environment. In addition, other safety and health issues found were ergonomics, heat stress, tripping hazards, electrical hazards, lockout/tagout, and arm-hand vibration.

  4. Blasting technology for modified in-situ oil shale retorts

    SciTech Connect

    Ricketts, T.E.

    1982-09-01

    Occidental Oil Shale, Inc., an equal partner with Tenneco Shale Oil Company in the Cathedral Bluffs Shale Oil Company, has spent since 1972 developing and demonstrating its modified in situ oil shale process at its Logan Wash mine near Debeque, Colorado. The Occidental modified in situ process consists of first mining out a limited amount of rock from within an underground retort volume to allow the explosive expansion of the surrounding rock into the mined void volumes. The explosive expansion forms a large underground rubble bed contained within a retort chamber which must contain a fairly uniform particle size distribution and void redistribution to provide reasonable oil recovery during subsequent in situ processing operations. The processing involves first igniting the top of the rubble pile and then injecting air into the top of the retort to drive the combustion front downward through the entire rubblized volume. The oil is continuously collected at the bottom of the retort during the processing. Two side-by-side commercial-sized retorts, Retorts 7 and 8, have recently been constructed at the Logan Wash mine using newly developed horizontal free-face blasting technology. Retorts 7 and 8 were blasted in February and April of 1981, respectively, each using nearly 550,000 lbs. of explosives in ANFO equivalent loaded within nearly 550 blastholes for each retort. The resulting rubble beds were about 230-ft high with cross-sections of approximately 27,225 ft/sup 2/. The blasting principles used to construct these commercial-sized retorts and the rubblization results are described in detail in this paper.

  5. Sprayer technology: reduce spray drift

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Enhancing environmental quality and sustaining the economic viability of food production are keys to sustainable agriculture. Modern vegetable production uses a variety of materials to manage pest problems. Selecting the proper spray nozzle for the application of liquid products is critical to red...

  6. Blast Injuries: From Improvised Explosive Device Blasts to the Boston Marathon Bombing.

    PubMed

    Singh, Ajay K; Ditkofsky, Noah G; York, John D; Abujudeh, Hani H; Avery, Laura A; Brunner, John F; Sodickson, Aaron D; Lev, Michael H

    2016-01-01

    Although most trauma centers have experience with the imaging and management of gunshot wounds, in most regions blast wounds such as the ones encountered in terrorist attacks with the use of improvised explosive devices (IEDs) are infrequently encountered outside the battlefield. As global terrorism becomes a greater concern, it is important that radiologists, particularly those working in urban trauma centers, be aware of the mechanisms of injury and the spectrum of primary, secondary, tertiary, and quaternary blast injury patterns. Primary blast injuries are caused by barotrauma from the initial increased pressure of the explosive detonation and the rarefaction of the atmosphere immediately afterward. Secondary blast injuries are caused by debris carried by the blast wind and most often result in penetrating trauma from small shrapnel. Tertiary blast injuries are caused by the physical displacement of the victim and the wide variety of blunt or penetrating trauma sustained as a result of the patient impacting immovable objects such as surrounding cars, walls, or fences. Quaternary blast injuries include all other injuries, such as burns, crush injuries, and inhalational injuries. Radiography is considered the initial imaging modality for assessment of shrapnel and fractures. Computed tomography is the optimal test to assess penetrating chest, abdominal, and head trauma. The mechanism of blast injuries and the imaging experience of the victims of the Boston Marathon bombing are detailed, as well as musculoskeletal, neurologic, gastrointestinal, and pulmonary injury patterns from blast injuries.

  7. Blast Injuries: From Improvised Explosive Device Blasts to the Boston Marathon Bombing.

    PubMed

    Singh, Ajay K; Ditkofsky, Noah G; York, John D; Abujudeh, Hani H; Avery, Laura A; Brunner, John F; Sodickson, Aaron D; Lev, Michael H

    2016-01-01

    Although most trauma centers have experience with the imaging and management of gunshot wounds, in most regions blast wounds such as the ones encountered in terrorist attacks with the use of improvised explosive devices (IEDs) are infrequently encountered outside the battlefield. As global terrorism becomes a greater concern, it is important that radiologists, particularly those working in urban trauma centers, be aware of the mechanisms of injury and the spectrum of primary, secondary, tertiary, and quaternary blast injury patterns. Primary blast injuries are caused by barotrauma from the initial increased pressure of the explosive detonation and the rarefaction of the atmosphere immediately afterward. Secondary blast injuries are caused by debris carried by the blast wind and most often result in penetrating trauma from small shrapnel. Tertiary blast injuries are caused by the physical displacement of the victim and the wide variety of blunt or penetrating trauma sustained as a result of the patient impacting immovable objects such as surrounding cars, walls, or fences. Quaternary blast injuries include all other injuries, such as burns, crush injuries, and inhalational injuries. Radiography is considered the initial imaging modality for assessment of shrapnel and fractures. Computed tomography is the optimal test to assess penetrating chest, abdominal, and head trauma. The mechanism of blast injuries and the imaging experience of the victims of the Boston Marathon bombing are detailed, as well as musculoskeletal, neurologic, gastrointestinal, and pulmonary injury patterns from blast injuries. PMID:26761543

  8. Explosive signatures: Pre & post blast

    NASA Astrophysics Data System (ADS)

    Bernier, Evan Thomas

    Manuscripts 1 and 2 of this dissertation both involve the pre-blast detection of trace explosive material. The first manuscript explores the analysis of human hair as an indicator of exposure to explosives. Field analysis of hair for trace explosives is quick and non-invasive, and could prove to be a powerful linkage to physical evidence in the form of bulk explosive material. Individuals tested were involved in studies which required handling or close proximity to bulk high explosives such as TNT, PETN, and RDX. The second manuscript reports the results of research in the design and application of canine training aids for non-traditional, peroxide-based explosives. Organic peroxides such as triacetonetriperoxide (TATP) and hexamethylenetriperoxidediamine (HMTD) can be synthesized relatively easily with store-bought ingredients and have become popular improvised explosives with many terrorist groups. Due to the hazards of handling such sensitive compounds, this research established methods for preparing training aids which contained safe quantities of TATP and HMTD for use in imprinting canines with their characteristic odor. Manuscripts 3 and 4 of this dissertation focus on research conducted to characterize pipe bombs during and after an explosion (post-blast). Pipe bombs represent a large percentage of domestic devices encountered by law enforcement. The current project has involved the preparation and controlled explosion of over 90 pipe bombs of different configurations in order to obtain data on fragmentation patterns, fragment velocity, blast overpressure, and fragmentation distance. Physical data recorded from the collected fragments, such as mass, size, and thickness, was correlated with the relative power of the initial device. Manuscript 4 explores the microstructural analysis of select pipe bomb fragments. Shock-loading of the pipe steel led to plastic deformation and work hardening in the steel grain structure as evidenced by optical microscopy and

  9. Integrated experimental platforms to study blast injuries: a bottom-up approach

    NASA Astrophysics Data System (ADS)

    Bo, C.; Williams, A.; Rankin, S.; Proud, W. G.; Brown, K. A.

    2014-05-01

    We are developing experimental models of blast injury using data from live biological samples. An integrated research strategy is followed to study material and biological properties of cells, tissues and organs, that are subjected to dynamic and static pressures, relevant to those of battlefield blast. We have developed a confined Split Hopkinson Pressure Bar (SHPB) system, which allows cells, either in suspension or as a monolayer, to be subjected to compression waves with pressures on the order of a few MPa and durations of hundreds of microseconds. The chamber design enables recovery of biological samples for cellular and molecular analysis. The SHPB platform, coupled with Quasi-Static experiments, is used to determine stress-strain curves of soft biological tissues under compression at low, medium and high strain rates. Tissue samples are examined, using histological techniques, to study macro- and microscopic changes induced by compression waves. In addition, a shock tube enables application of single or multiple air blasts with pressures on the order of kPa and a few milliseconds duration; this platform was used for initial studies on mesenchymal stem cells responses to blast pressures.

  10. Blast wave loading pathways in heterogeneous material systems-experimental and numerical approaches.

    PubMed

    Selvan, Veera; Ganpule, Shailesh; Kleinschmit, Nick; Chandra, Namas

    2013-06-01

    Blast waves generated in the field explosions impinge on the head-brain complex and induce mechanical pressure pulses in the brain resulting in traumatic brain injury. Severity of the brain injury (mild to moderate to severe) is dependent upon the magnitude and duration of the pressure pulse, which in turn depends on the intensity and duration of the oncoming blast wave. A fluid-filled cylinder is idealized to represent the head-brain complex in its simplest form; the cylinder is experimentally subjected to an air blast of Friedlander type, and the temporal variations of cylinder surface pressures and strains and fluid pressures are measured. Based on these measured data and results from computational simulations, the mechanical loading pathways from the external blast to the pressure field in the fluid are identified; it is hypothesized that the net loading at a given material point in the fluid comprises direct transmissive loads and deflection-induced indirect loads. Parametric studies show that the acoustic impedance mismatches between the cylinder and the contained fluid as well as the flexural rigidity of the cylinder determine the shape/intensity of pressure pulses in the fluid. PMID:23699714

  11. Dry media blasting with wheat starch

    NASA Astrophysics Data System (ADS)

    Foster, Terry

    1995-04-01

    The brand name TECHNOSTRIP covers several types of installations and facilities. These were developed mainly to meet the requirements of customers in the aeronautic field. The range of products includes: complete self-supporting and semi-automated system for aircraft stripping; large-size blasting booth for semi-automatic stripping; manual blasting booth; and sealed and portable manual stripping head. Wheat starch media was developed for particle blasting stripping and is used in TECHNOSTRIP. This paper reviews its origins and use as well as use of automated facilities, reliability, effects on materials, effects on environment, and utilization examples.

  12. CO{sub 2} pellet blasting studies

    SciTech Connect

    Archibald, K.E.

    1997-01-01

    Initial tests with CO{sub 2} pellet blasting as a decontamination technique were completed in 1993 at the Idaho Chemical Processing Plant (ICPP) at the Idaho National Engineering Laboratory (INEL). During 1996, a number of additional CO{sub 2} pellet blasting studies with Alpheus Cleaning Technologies, Oak Ridge National Laboratory, and Pennsylvania State University were conducted. After the testing with Alpheus was complete, an SDI-5 shaved CO{sub 2} blasting unit was purchased by the ICPP to test and determine its capabilities before using in ICPP decontamination efforts. Results of the 1996 testing will be presented in this report.

  13. Fluid/Structure Interaction Computational Investigation of Blast-Wave Mitigation Efficacy of the Advanced Combat Helmet

    NASA Astrophysics Data System (ADS)

    Grujicic, M.; Bell, W. C.; Pandurangan, B.; Glomski, P. S.

    2011-08-01

    To combat the problem of traumatic brain injury (TBI), a signature injury of the current military conflicts, there is an urgent need to design head protection systems with superior blast/ballistic impact mitigation capabilities. Toward that end, the blast impact mitigation performance of an advanced combat helmet (ACH) head protection system equipped with polyurea suspension pads and subjected to two different blast peak pressure loadings has been investigated computationally. A fairly detailed (Lagrangian) finite-element model of a helmet/skull/brain assembly is first constructed and placed into an Eulerian air domain through which a single planar blast wave propagates. A combined Eulerian/Lagrangian transient nonlinear dynamics computational fluid/solid interaction analysis is next conducted in order to assess the extent of reduction in intra-cranial shock-wave ingress (responsible for TBI). This was done by comparing temporal evolutions of intra-cranial normal and shear stresses for the cases of an unprotected head and the helmet-protected head and by correlating these quantities with the three most common types of mild traumatic brain injury (mTBI), i.e., axonal damage, contusion, and subdural hemorrhage. The results obtained show that the ACH provides some level of protection against all investigated types of mTBI and that the level of protection increases somewhat with an increase in blast peak pressure. In order to rationalize the aforementioned findings, a shockwave propagation/reflection analysis is carried out for the unprotected head and helmet-protected head cases. The analysis qualitatively corroborated the results pertaining to the blast-mitigation efficacy of an ACH, but also suggested that there are additional shockwave energy dissipation phenomena which play an important role in the mechanical response of the unprotected/protected head to blast impact.

  14. Measurement of effective blast energy for direct initiation of spherical gaseous detonations from high-voltage spark discharge

    NASA Astrophysics Data System (ADS)

    Zhang, B.; Ng, H. D.; Lee, J. H. S.

    2012-01-01

    In this study, effective energy from spark discharge for direct blast initiation of spherical gaseous detonations is investigated. In the experiment, direct initiation of detonation is achieved via a spark discharge from a high-voltage and low-inductance capacitor bank and the spark energy is estimated from the analysis of the current output. To determine the blast wave energy from the powerful spark, the time-of-arrival of the blast wave in air is measured at different radii using a piezoelectric pressure transducer. Good agreement is found in the scaled blast trajectories, i.e., scaled time c o· t/ R o where c o is the ambient sound speed, as a function of blast radius R s/ R o between the numerical simulation of a spherical blast wave from a point energy source and the experimental results where the explosion length scale R o is computed using the equivalent spark energy from the first 1/4 current discharge cycle. Alternatively, by fitting the experimental trajectories data, the blast energy estimated from the numerical simulation appears also in good agreement with that obtained experimentally using the 1/4 cycle criterion. Using the 1/4 cycle of spark discharge for the effective energy, direct initiation experiments of spherical gaseous detonations are carried out to determine the critical initiation energy in C2H2-2.5O2 mixtures with 70 and 0% argon dilution. The experimental results obtained from the 1/4 cycle of spark discharge agree well with the prediction from two initiation models, namely, the Lee's surface energy model and a simplified work done model. The main source of discrepancy in the comparison can be explained by the uncertainty of cell size measurement which is needed for both the semi-empirical models.

  15. Altered Gene Expression in Cultured Microglia in Response to Simulated Blast Overpressure: Possible Role of Pulse Duration

    PubMed Central

    Kane, Michael J.; Angoa-Pérez, Mariana; Francescutti, Dina M.; Sykes, Catherine E.; Briggs, Denise I.; Leung, Lai Yee; VandeVord, Pamela J.; Kuhn, Donald M.

    2012-01-01

    Blast overpressure has long been known to cause barotrauma to air-filled organs such as lung and middle ear. However, experience in Iraq and Afghanistan is revealing that individuals exposed to explosive munitions can also suffer traumatic brain injury (TBI) even in the absence of obvious external injury. The interaction of a blast shock wave with the brain in the intact cranial vault is extremely complex making it difficult to conclude that a blast wave interacts in a direct manner with the brain to cause injury. In an attempt to “isolate” the shock wave and test its primary effects on cells, we exposed cultured microglia to simulated blast overpressure in a barochamber. Overpressures ranging from 15–45 psi did not change microglial Cox-2 levels or TNF-α secretion nor did they cause cell damage. Microarray analysis revealed increases in expression of a number of microglial genes relating to immune function and inflammatory responses to include Saa3, Irg1, Fas and CxCl10. All changes in gene expression were dependent on pulse duration and were independent of pressure. These results indicate that microglia are mildly activated by blast overpressure and uncover a heretofore undocumented role for pulse duration in this process. PMID:22698585

  16. Symmetry assessment of an air-blast atomizer spray

    NASA Technical Reports Server (NTRS)

    Mcdonnell, V. G.; Cameron, C. D.; Samuelsen, G. S.

    1990-01-01

    This study represents an evaluation of the extent to which conventional and recently introduced modern diagnostics can assess the symmetry of sprays formed by three atomizers of identical design. The conventional diagnostics include sheet-lit photography, patternation, and laser diffraction. The modern diagnostic is laser interferometry (phase Doppler). Symmetry is assessed in ambient conditions for four atomizer orientations, and comparisons are made between the diagnostic techniques. The results demonstrate that conventional and modern diagnostics are consistent in the assessment of symmetry, patternation and phase Doppler are most effective in establishing symmetry of mass flux, and phase Doppler, although more tedious to employ, provides the additional information necessary to establish the sources of detected asymmetries in terms of nonuniformities in droplet velocities, size distributions, volume flux, and concentration.

  17. Theory of the arc discharge in air blast breakers

    SciTech Connect

    Vogel, H.F.

    1980-08-01

    The complete set of equations obtaining in the arc's length element are given. The arc length is determined when the external circuit equations are closed by an expression for the arc inductance as a function of the radius and length, in addition to our relationships for the radius and voltage gradients.

  18. Characterization of blasted austenitic stainless steel and its corrosion resistance

    NASA Astrophysics Data System (ADS)

    Otsubo, F.; Kishitake, K.; Akiyama, T.; Terasaki, T.

    2003-12-01

    It is known that the corrosion resistance of stainless steel is deteriorated by blasting, but the reason for this deterioration is not clear. A blasted austenitic stainless steel plate (JIS-SUS304) has been characterized with comparison to the scraped and non-blasted specimens. The surface roughness of the blasted specimen is larger than that of materials finished with #180 paper. A martensite phase is formed in the surface layer of both blasted and scraped specimens. Compressive residual stress is generated in the blasted specimen and the maximum residual stress is formed at 50 100 µm from the surface. The corrosion potentials of the blasted specimen and subsequently solution treated specimen are lower than that of the non-blasted specimen. The passivation current densities of the blasted specimens are higher those of the non-blasted specimen. The blasted specimen and the subsequently solution treated specimen exhibit rust in 5% sodium chloride (NaCl) solution, while the non-blasted specimen and ground specimen do not rust in the solution. It is concluded that the deterioration of corrosion resistance of austenitic stainless steel through blasting is caused by the roughed morphology of the surface.

  19. Nucleon and Deuteron Form Factors from BLAST

    SciTech Connect

    Hasell, D. K.

    2009-12-17

    The BLAST experiment was designed to study in a systematic manner the spin-dependent, electromagnetic interaction on hydrogen and deuterium. Measuring only asymmetries in electron scattering with respect to the beam helicity, target spin, or both; the BLAST experiment was able to extract information on nucleon and deuteron form factors independent of beam intensity or target density. By further forming 'super-ratios' of asymmetries, measurements were possible independent of beam and target polarization thus reducing uncertainties due to these quantities as well. Some of the form factor results from BLAST will be briefly presented here. Also, in response to observed discrepancies between polarization measurements and those obtained using traditional Rosenbluth separation techniques a proposed experiment, OLYMPUS, which will use the BLAST detector to measure the two photon contribution to elastic electron scattering will also be presented.

  20. 30 CFR 72.610 - Abrasive blasting.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... respirators approved for abrasive blasting by NIOSH under 42 CFR part 84, or the operation shall be performed... mines. Silica sand or other materials containing more than 1 percent free silica shall not be used as...

  1. 30 CFR 72.610 - Abrasive blasting.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... respirators approved for abrasive blasting by NIOSH under 42 CFR part 84, or the operation shall be performed... mines. Silica sand or other materials containing more than 1 percent free silica shall not be used as...

  2. 30 CFR 72.610 - Abrasive blasting.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... respirators approved for abrasive blasting by NIOSH under 42 CFR part 84, or the operation shall be performed... mines. Silica sand or other materials containing more than 1 percent free silica shall not be used as...

  3. 30 CFR 72.610 - Abrasive blasting.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... respirators approved for abrasive blasting by NIOSH under 42 CFR part 84, or the operation shall be performed... mines. Silica sand or other materials containing more than 1 percent free silica shall not be used as...

  4. 30 CFR 72.610 - Abrasive blasting.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... respirators approved for abrasive blasting by NIOSH under 42 CFR part 84, or the operation shall be performed... mines. Silica sand or other materials containing more than 1 percent free silica shall not be used as...

  5. Material Systems for Blast-Energy Dissipation

    SciTech Connect

    James Schondel; Henry S. Chu

    2010-10-01

    Lightweight panels have been designed to protect buildings and vehicles from blast pressures by activating energy dissipation mechanisms under the influence of blast loading. Panels were fabricated which featured a variety of granular materials and hydraulic dissipative deformation mechanisms and the test articles were subjected to full-scale blast loading. The force time-histories transmitted by each technology were measured by a novel method that utilized inexpensive custom-designed force sensors. The array of tests revealed that granular materials can effectively dissipate blast energy if they are employed in a way that they easily crush and rearrange. Similarly, hydraulic dissipation can effectively dissipate energy if the panel features a high fraction of porosity and the panel encasement features low compressive stiffness.

  6. Perfluorocarbon vapor tagging of blasting cap detonators

    DOEpatents

    Dietz, R.N.; Senum, G.I.

    A plug for a blasting cap is made of an elastomer in which is dissolved a perfluorocarbon. The perfluorocarbon is released as a vapor into the ambient over a long period of time to serve as a detectable taggant.

  7. Space shuttle holddown post blast shield

    NASA Technical Reports Server (NTRS)

    Larracas, F. B.

    1991-01-01

    The original and subsequent designs of the Solid Rocket Booster/Holddown Post blast shield assemblies and their associated hardware are described. It presents the major problems encountered during their early use in the Space Shuttle Program, during the Return-to-Flight Modification Phase, and during their fabrication and validation testing phases. The actions taken to correct the problems are discussed, along with the various concepts now being considered to increase the useful life of the blast shield.

  8. Lightweight Energy Absorbers for Blast Containers

    NASA Technical Reports Server (NTRS)

    Balles, Donald L.; Ingram, Thomas M.; Novak, Howard L.; Schricker, Albert F.

    2003-01-01

    Kinetic-energy-absorbing liners made of aluminum foam have been developed to replace solid lead liners in blast containers on the aft skirt of the solid rocket booster of the space shuttle. The blast containers are used to safely trap the debris from small explosions that are initiated at liftoff to sever frangible nuts on hold-down studs that secure the spacecraft to a mobile launch platform until liftoff.

  9. Localized coating removal using plastic media blasting

    NASA Technical Reports Server (NTRS)

    Novak, Howard L.; Wyckoff, Michael G.; Zook, Lee M.

    1988-01-01

    Steps taken to qualify the use of plastic media blasting for safely and effectively removing paint and other coatings from solid rocket booster aluminum structures are described. As a result of the effort, an improvement was made in the design of surface finishing equipment for processing flight hardware, in addition to a potentially patentable idea on improved plastic media composition. The general arrangement of the blast equipment and the nozzle configuration are presented.

  10. Neuropathology of explosive blast traumatic brain injury.

    PubMed

    Magnuson, John; Leonessa, Fabio; Ling, Geoffrey S F

    2012-10-01

    During the conflicts of the Global War on Terror, which are Operation Enduring Freedom (OEF) in Afghanistan and Operation Iraqi Freedom (OIF), there have been over a quarter of a million diagnosed cases of traumatic brain injury (TBI). The vast majority are due to explosive blast. Although explosive blast TBI (bTBI) shares many clinical features with closed head TBI (cTBI) and penetrating TBI (pTBI), it has unique features, such as early cerebral edema and prolonged cerebral vasospasm. Evolving work suggests that diffuse axonal injury (DAI) seen following explosive blast exposure is different than DAI from focal impact injury. These unique features support the notion that bTBI is a separate and distinct form of TBI. This review summarizes the current state of knowledge pertaining to bTBI. Areas of discussion are: the physics of explosive blast generation, blast wave interaction with the bony calvarium and brain tissue, gross tissue pathophysiology, regional brain injury, and cellular and molecular mechanisms of explosive blast neurotrauma.

  11. Information modeling system for blast furnace control

    NASA Astrophysics Data System (ADS)

    Spirin, N. A.; Gileva, L. Y.; Lavrov, V. V.

    2016-09-01

    Modern Iron & Steel Works as a rule are equipped with powerful distributed control systems (DCS) and databases. Implementation of DSC system solves the problem of storage, control, protection, entry, editing and retrieving of information as well as generation of required reporting data. The most advanced and promising approach is to use decision support information technologies based on a complex of mathematical models. The model decision support system for control of blast furnace smelting is designed and operated. The basis of the model system is a complex of mathematical models created using the principle of natural mathematical modeling. This principle provides for construction of mathematical models of two levels. The first level model is a basic state model which makes it possible to assess the vector of system parameters using field data and blast furnace operation results. It is also used to calculate the adjustment (adaptation) coefficients of the predictive block of the system. The second-level model is a predictive model designed to assess the design parameters of the blast furnace process when there are changes in melting conditions relative to its current state. Tasks for which software is developed are described. Characteristics of the main subsystems of the blast furnace process as an object of modeling and control - thermal state of the furnace, blast, gas dynamic and slag conditions of blast furnace smelting - are presented.

  12. Ultra Safe And Secure Blasting System

    SciTech Connect

    Hart, M M

    2009-07-27

    The Ultra is a blasting system that is designed for special applications where the risk and consequences of unauthorized demolition or blasting are so great that the use of an extraordinarily safe and secure blasting system is justified. Such a blasting system would be connected and logically welded together through digital code-linking as part of the blasting system set-up and initialization process. The Ultra's security is so robust that it will defeat the people who designed and built the components in any attempt at unauthorized detonation. Anyone attempting to gain unauthorized control of the system by substituting components or tapping into communications lines will be thwarted in their inability to provide encrypted authentication. Authentication occurs through the use of codes that are generated by the system during initialization code-linking and the codes remain unknown to anyone, including the authorized operator. Once code-linked, a closed system has been created. The system requires all components connected as they were during initialization as well as a unique code entered by the operator for function and blasting.

  13. Underwater blast injury: a review of standards.

    PubMed

    Lance, Rachel M; Bass, Cameron R

    2015-09-01

    The first cases of underwater blast injury appeared in the scientific literature in 1917, and thousands of service members and civilians were injured or killed by underwater blast during WWII. The prevalence of underwater blast injuries and occupational blasting needs led to the development of many safety standards to prevent injury or death. Most of these standards were not supported by experimental data or testing. In this review, we describe existing standards, discuss their origins, and we comprehensively compare their prescriptions across standards. Surprisingly, we found that most safety standards had little or no scientific basis, and prescriptions across standards often varied by at least an order of magnitude. Many published standards traced back to a US Navy 500 psi guideline, which was intended to provide a peak pressure at which injuries were likely to occur. This standard itself seems to have been based upon a completely unfounded assertion that has propagated throughout the literature in subsequent years. Based on the limitations of the standards discussed, we outline future directions for underwater blast injury research, such as the compilation of epidemiological data to examine actual injury risk by human beings subjected to underwater blasts.

  14. Underwater blast injury: a review of standards.

    PubMed

    Lance, Rachel M; Bass, Cameron R

    2015-09-01

    The first cases of underwater blast injury appeared in the scientific literature in 1917, and thousands of service members and civilians were injured or killed by underwater blast during WWII. The prevalence of underwater blast injuries and occupational blasting needs led to the development of many safety standards to prevent injury or death. Most of these standards were not supported by experimental data or testing. In this review, we describe existing standards, discuss their origins, and we comprehensively compare their prescriptions across standards. Surprisingly, we found that most safety standards had little or no scientific basis, and prescriptions across standards often varied by at least an order of magnitude. Many published standards traced back to a US Navy 500 psi guideline, which was intended to provide a peak pressure at which injuries were likely to occur. This standard itself seems to have been based upon a completely unfounded assertion that has propagated throughout the literature in subsequent years. Based on the limitations of the standards discussed, we outline future directions for underwater blast injury research, such as the compilation of epidemiological data to examine actual injury risk by human beings subjected to underwater blasts. PMID:26415071

  15. 30 CFR 57.6605 - Isolation of blasting circuits.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Extraneous Electricity-Surface and Underground § 57.6605 Isolation of blasting circuits. Lead wires and... shall be protected from sources of stray or static electricity. Blasting circuits shall be...

  16. 30 CFR 57.6605 - Isolation of blasting circuits.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Extraneous Electricity-Surface and Underground § 57.6605 Isolation of blasting circuits. Lead wires and... shall be protected from sources of stray or static electricity. Blasting circuits shall be...

  17. 30 CFR 57.6605 - Isolation of blasting circuits.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Extraneous Electricity-Surface and Underground § 57.6605 Isolation of blasting circuits. Lead wires and... shall be protected from sources of stray or static electricity. Blasting circuits shall be...

  18. 30 CFR 57.6605 - Isolation of blasting circuits.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Extraneous Electricity-Surface and Underground § 57.6605 Isolation of blasting circuits. Lead wires and... shall be protected from sources of stray or static electricity. Blasting circuits shall be...

  19. 30 CFR 57.6605 - Isolation of blasting circuits.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Extraneous Electricity-Surface and Underground § 57.6605 Isolation of blasting circuits. Lead wires and... shall be protected from sources of stray or static electricity. Blasting circuits shall be...

  20. 58. LOOKING EAST DOROTHY SIX BLAST FURNACE WITH BRICK SHED ...

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

    58. LOOKING EAST DOROTHY SIX BLAST FURNACE WITH BRICK SHED No. 3 IN FOREGROUND ON RIGHT. (Jet Lowe) - U.S. Steel Duquesne Works, Blast Furnace Plant, Along Monongahela River, Duquesne, Allegheny County, PA

  1. 13. SOUTHWEST VIEW OF CAST HOUSE No. 1, BLAST FURNACE ...

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

    13. SOUTHWEST VIEW OF CAST HOUSE No. 1, BLAST FURNACE No. 1, AND HOIST HOUSE No. 1. (Martin Stupich) - U.S. Steel Duquesne Works, Blast Furnace Plant, Along Monongahela River, Duquesne, Allegheny County, PA

  2. INTERIOR VIEW OF BLAST FURNACE NO. 3 LOOKING EAST, SLAG ...

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

    INTERIOR VIEW OF BLAST FURNACE NO. 3 LOOKING EAST, SLAG RUNNERS & GATES IN FOREGROUND. - Pittsburgh Steel Company, Monessen Works, Blast Furnace No. 3, Donner Avenue, Monessen, Westmoreland County, PA

  3. 68. DETAIL OF COOLING WATER PIPES FOR DOROTHY SIX BLAST ...

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

    68. DETAIL OF COOLING WATER PIPES FOR DOROTHY SIX BLAST FURNACE. INTERIOR OF CAST HOUSE LOOKING NORTH. (Jet Lowe) - U.S. Steel Duquesne Works, Blast Furnace Plant, Along Monongahela River, Duquesne, Allegheny County, PA

  4. 70. CONTROL PANEL INSIDE OF THE DOROTHY SIX BLAST FURNACE ...

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

    70. CONTROL PANEL INSIDE OF THE DOROTHY SIX BLAST FURNACE STOCKHOUSE LOOKING NORTH. (Jet Lowe) - U.S. Steel Duquesne Works, Blast Furnace Plant, Along Monongahela River, Duquesne, Allegheny County, PA

  5. 3. VIEW OF DUQUESNE'S RAIL LINES AND BLAST FURNACE PLANT ...

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

    3. VIEW OF DUQUESNE'S RAIL LINES AND BLAST FURNACE PLANT LOOKING NORTH. DOROTHY SIX IS THE CLOSEST FURNACE IN THE PHOTOGRAPH. (Jet Lowe) - U.S. Steel Duquesne Works, Blast Furnace Plant, Along Monongahela River, Duquesne, Allegheny County, PA

  6. 1. LOOKING EAST AT BLAST FURNACES NO. 3 AND No. ...

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

    1. LOOKING EAST AT BLAST FURNACES NO. 3 AND No. 4 FROM CRAWFORD STREET IN THE CITY OF DUQUESNE. (Martin Stupich) - U.S. Steel Duquesne Works, Blast Furnace Plant, Along Monongahela River, Duquesne, Allegheny County, PA

  7. 56. LOOKING NORTH AT DOROTHY SIX BLAST FURNACE WITH CAST ...

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

    56. LOOKING NORTH AT DOROTHY SIX BLAST FURNACE WITH CAST HOUSE IN FOREGROUND AND DUSTCATCHER AT RIGHT OF FURNACE (Jet Lowe) - U.S. Steel Duquesne Works, Blast Furnace Plant, Along Monongahela River, Duquesne, Allegheny County, PA

  8. INTERIOR VIEW LOOKING EAST, BLAST FURNACE NO. 1 CLOSEUP, IRON ...

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

    INTERIOR VIEW LOOKING EAST, BLAST FURNACE NO. 1 CLOSE-UP, IRON NOTCH IN CENTER. - Pittsburgh Steel Company, Monessen Works, Blast Furnace No. 1 & No. 2, Donner Avenue, Monessen, Westmoreland County, PA

  9. 7. LOOKING EAST AT HOIST HOUSE No. 1 AND BLAST ...

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

    7. LOOKING EAST AT HOIST HOUSE No. 1 AND BLAST FURNACE No. 1, WITH ORE YARD AND ORE BRIDGES IN FOREGROUND. (Jet Lowe) - U.S. Steel Duquesne Works, Blast Furnace Plant, Along Monongahela River, Duquesne, Allegheny County, PA

  10. 55. GENERAL NORTHEASTERN VIEW OF DOROTHY SIX BLAST FURNACE COMPLEX ...

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

    55. GENERAL NORTHEASTERN VIEW OF DOROTHY SIX BLAST FURNACE COMPLEX WITH LADLE HOUSE AND IRON DESULPHERIZATION BUILDING ON RIGHT. (Jet Lowe) - U.S. Steel Duquesne Works, Blast Furnace Plant, Along Monongahela River, Duquesne, Allegheny County, PA

  11. EXTERIOR VIEW, BLAST FURNACE NO. 3 (JANE FURNACE) CENTER, NO. ...

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

    EXTERIOR VIEW, BLAST FURNACE NO. 3 (JANE FURNACE) CENTER, NO. 3 CAST HOUSE TO THE LEFT, WEST ORE BRIDGE TO THE RIGHT. - Pittsburgh Steel Company, Monessen Works, Blast Furnace No. 3, Donner Avenue, Monessen, Westmoreland County, PA

  12. 59. REMAINS OF THE DOROTHY SIX BLAST FURNACE COMPLEX LOOKING ...

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

    59. REMAINS OF THE DOROTHY SIX BLAST FURNACE COMPLEX LOOKING NORTHEAST. THE LADLE HOUSE IS ON THE RIGHT. (Martin Stupich) - U.S. Steel Duquesne Works, Blast Furnace Plant, Along Monongahela River, Duquesne, Allegheny County, PA

  13. 31. VIEW OF TRIPPER CAR ON TOP OF BLAST FURNACE ...

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

    31. VIEW OF TRIPPER CAR ON TOP OF BLAST FURNACE STOCKING TRESTLE LOOKING EAST. (Martin Stupich) - U.S. Steel Duquesne Works, Blast Furnace Plant, Along Monongahela River, Duquesne, Allegheny County, PA

  14. VIEW LOOKING NORTHWEST WITH OPENHEARTH TO LEFT WITH BLAST FURNACE ...

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

    VIEW LOOKING NORTHWEST WITH OPEN-HEARTH TO LEFT WITH BLAST FURNACE NO. 2 AND CAST HOUSE TO THE RIGHT. - Pittsburgh Steel Company, Monessen Works, Blast Furnace No. 1 & No. 2, Donner Avenue, Monessen, Westmoreland County, PA

  15. VIEW FACING EAST, VIEW FROM RIVER OF BLAST FURNACE NO. ...

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

    VIEW FACING EAST, VIEW FROM RIVER OF BLAST FURNACE NO. 3. DORR THICKENER & ORE BRIDGE AT LEFT, HOT BLAST STOVES & DUST CATCHER CENTER, CAST HOUSE AT RIGHT. - Pittsburgh Steel Company, Monessen Works, Donner Avenue, Monessen, Westmoreland County, PA

  16. DETAIL VIEW OF THE STOVES WITH HOT BLAST MAIN. #2 ...

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

    DETAIL VIEW OF THE STOVES WITH HOT BLAST MAIN. #2 BLAST FURNACE IS TO THE IMMEDIATE LEFT. VIEW FROM THE SOUTHWEST. - Sloss-Sheffield Steel & Iron, First Avenue North Viaduct at Thirty-second Street, Birmingham, Jefferson County, AL

  17. 6. Photocopy of a drawing of the lead blast furnace ...

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

    6. Photocopy of a drawing of the lead blast furnace from J.L. Bray, The Principles of Metallurgy, Ginn & Co. New York, 1929. - International Smelting & Refining Company, Tooele Smelter, Blast Furnace Building, State Route 178, Tooele, Tooele County, UT

  18. June 7 Ballistic Blast Results in Solar Tsunami

    NASA Video Gallery

    In addition to the magnificent blast, SDO detected a shadowy shock wave issuing from the blast site on the June 7, 2011 event. The 'solar tsunami' propagated more than halfway across the sun, visib...

  19. Comparison of Some Blast Vibration Predictors for Blasting in Underground Drifts and Some Observations

    NASA Astrophysics Data System (ADS)

    Bhagwat, Vaibhab Pramod; Dey, Kaushik

    2016-04-01

    Drilling and blasting are the most economical excavation techniques in underground drifts driven through hard rock formation. Burn cut is the most popular drill pattern, used in this case, to achieve longer advance per blast round. The ground vibration generated due to the propagation of blast waves on the detonation of explosive during blasting is the principal cause for structural and rock damage. Thus, ground vibration is a point of concern for the blasting engineers. The ground vibration from a blast is measured using a seismograph placed at the blast monitoring station. The measured vibrations, in terms of peak particle velocity, are related to the maximum charge detonated at one instant and the distance of seismograph from the blast point. The ground vibrations from a number of blast rounds of varying charge/delay and distances are monitored. A number of scaling factors of these dependencies (viz. Distance and maximum charge/delay) have been proposed by different researchers, namely, square root, cube root, CMRI, Langefors and Kihlstrom, Ghosh-Daemon, Indian standard etc. Scaling factors of desired type are computed for all the measured blast rounds. Regression analysis is carried out between the scaling factors and peak particle velocities to establish the coefficients of the vibration predictor equation. Then, the developed predictor equation is used for designing the blast henceforth. Director General of Mine Safety, India, specified that ground vibrations from eight to ten blast rounds of varying charge/delay and distances should be monitored to develop a predictor equation; however, there is no guideline about the type of scaling factor to be used. Further to this, from the statistical point of view, a regression analysis on a small sample population cannot be accepted without the testing of hypothesis. To show the importance of the above, in this paper, seven scaling factors are considered for blast data set of a hard-rock underground drift using burn

  20. Blast traumatic brain injury in the rat using a blast overpressure model.

    PubMed

    Yarnell, Angela M; Shaughness, Michael C; Barry, Erin S; Ahlers, Stephen T; McCarron, Richard M; Grunberg, Neil E

    2013-01-01

    Traumatic brain injury (TBI) is a serious health concern for civilians and military populations, and blast-induced TBI (bTBI) has become an increasing problem for military personnel over the past 10 years. To understand the biological and psychological effects of blast-induced injuries and to examine potential interventions that may help to prevent, attenuate, and treat effects of bTBI, it is valuable to conduct controlled animal experiments. This unit discusses available paradigms to model traumatic brain injury in animals, with an emphasis on the relevance of these various models to study blast-induced traumatic brain injury (bTBI). This paper describes the detailed methods of a blast overpressure (BOP) paradigm that has been used to conduct experiments with rats to model blast exposure. This particular paradigm models the pressure wave created by explosions, including improvised explosive devices (IEDs).

  1. Simulation of the ERDC Blast Load Simulator (BLS) in various test configurations using Loci/BLAST

    NASA Astrophysics Data System (ADS)

    Mord, Clayton T.

    This thesis describes the simulation of ERDC's Blast Load Simulator (BLS) using MSU's Loci/BLAST. The BLS was created to replicate waveforms found in blast scenarios. Loci/BLAST is an explicit, unstructured CFD code that specializes in moving waveforms. ERDC conducted various tests, and a grid for each scenario was created using the SolidMesh tool. Each grid was simulated, and the results were displayed as time history plots and spatial plots. Simulations were also performed that compared 2D and 3D grids and determined the effect of the grate and striker components. There was a strong correlation between the experimental and simulation results for each case, demonstrating that Loci/BLAST is fully capable of modeling the BLS waveforms. A 2D grid produced results comparable to those on a full 3D grid. The grate and striker were critical in the simulation because they significantly affected the waveform.

  2. Separation and quantitation of hazardous wastes from abrasive blast media.

    PubMed

    Hwang, J Y; Jeong, M L

    2001-01-01

    A sample of glass bead abrasive blasting material (ABM) waste, received from Robins Air Force Base (Georgia), was examined to determine whether the waste could be rendered nonhazardous by separating paint contaminants from the ABM. The sample was analyzed with size distribution and toxicity characteristics leaching procedure. A Microtrac analyzer was used to measure the size of fine particles (-325 Tyler mesh), and scanning electron microscopy analysis was performed to identify the nature of the contaminants in the ABM waste. Tests using froth flotation, magnetic separation, desliming, and acid washing were conducted to develop a process for removing the contaminants. A pilot plant test using the developed process rendered 82.1% or the ABM waste material nonhazardous.

  3. Grit blast/silane surface treatment for structural bonding of aluminum

    SciTech Connect

    Mazza, J.J.

    1996-12-31

    The use of silane coupling agents as prebond surface treatments for aluminum aircraft structure is not new. The Royal Australian Air Force (RAAF) has extensively used a silane surface preparation in applications of bonded composite repairs to aircraft structure. Recently, the USAF has begun to employ bonded composite repair technology as a means to extend the service lives of its aging aircraft. A grit blast/silane surface treatment optimized by the USAF Wright Laboratory Materials Directorate (ML) has been used in many of the applications, most notably on the C-141 aircraft. The ML process is desirable for many USAF applications since it does not contain acids which could harm aircraft structure, and it is similar to the Australian technique which has claimed years of success. The ML grit blast/silane surface treatment was inspired by the Australian process which was developed by the Aeronautical and Maritime Research Laboratory (AMRL). The Australians generated considerable interest in their process, however, several key organizations were unable to duplicate the performance cited by AMRL. Some questioned the viability of the Australian silane process. To resolve this question for Warner Robins Air Logistics Center (WR-ALC) personnel, as well as continue ML`s ongoing silane work, a program was run to understand the AMRL surface prep. This led to the development of the ML grit blast/silane process and its on-aircraft applications.

  4. An introductory characterization of a combat-casualty-care relevant swine model of closed head injury resulting from exposure to explosive blast.

    PubMed

    Bauman, Richard A; Ling, Geoffrey; Tong, Lawrence; Januszkiewicz, Adolph; Agoston, Dennis; Delanerolle, Nihal; Kim, Young; Ritzel, Dave; Bell, Randy; Ecklund, James; Armonda, Rocco; Bandak, Faris; Parks, Steven

    2009-06-01

    Explosive blast has been extensively used as a tactical weapon in Operation Iraqi Freedom (OIF) and more recently in Operation Enduring Freedom(OEF). The polytraumatic nature of blast injuries is evidence of their effectiveness,and brain injury is a frequent and debilitating form of this trauma. In-theater clinical observations of brain-injured casualties have shown that edema, intracranial hemorrhage, and vasospasm are the most salient pathophysiological characteristics of blast injury to the brain. Unfortunately, little is known about exactly how an explosion produces these sequelae as well as others that are less well documented. Consequently, the principal objective of the current report is to present a swine model of explosive blast injury to the brain. This model was developed during Phase I of the DARPA (Defense Advanced Research Projects Agency) PREVENT (Preventing Violent Explosive Neurotrauma) blast research program. A second objective is to present data that illustrate the capabilities of this model to study the proximal biomechanical causes and the resulting pathophysiological, biochemical,neuropathological, and neurological consequences of explosive blast injury to the swine brain. In the concluding section of this article, the advantages and limitations of the model are considered, explosive and air-overpressure models are compared, and the physical properties of an explosion are identified that potentially contributed to the in-theater closed head injuries resulting from explosions of improvised explosive devices (IEDs).

  5. Cygnus Loop Supernova Blast Wave

    NASA Technical Reports Server (NTRS)

    1993-01-01

    This is an image of a small portion of the Cygnus Loop supernova remnant, which marks the edge of a bubble-like, expanding blast wave from a colossal stellar explosion, occurring about 15,000 years ago. The HST image shows the structure behind the shock waves, allowing astronomers for the first time to directly compare the actual structure of the shock with theoretical model calculations. Besides supernova remnants, these shock models are important in understanding a wide range of astrophysical phenomena, from winds in newly-formed stars to cataclysmic stellar outbursts. The supernova blast is slamming into tenuous clouds of insterstellar gas. This collision heats and compresses the gas, causing it to glow. The shock thus acts as a searchlight revealing the structure of the interstellar medium. The detailed HST image shows the blast wave overrunning dense clumps of gas, which despite HST's high resolution, cannot be resolved. This means that the clumps of gas must be small enough to fit inside our solar system, making them relatively small structures by interstellar standards. A bluish ribbon of light stretching left to right across the picture might be a knot of gas ejected by the supernova; this interstellar 'bullet' traveling over three million miles per hour (5 million kilometres) is just catching up with the shock front, which has slowed down by ploughing into interstellar material. The Cygnus Loop appears as a faint ring of glowing gases about three degrees across (six times the diameter of the full Moon), located in the northern constellation, Cygnus the Swan. The supernova remnant is within the plane of our Milky Way galaxy and is 2,600 light-years away. The photo is a combination of separate images taken in three colors, oxygen atoms (blue) emit light at temperatures of 30,000 to 60,000 degrees Celsius (50,000 to 100,000 degrees Farenheit). Hydrogen atoms (green) arise throughout the region of shocked gas. Sulfur atoms (red) form when the gas cools to

  6. Improvement in the properties of plasma-sprayed metallic, alloy and ceramic coatings using dry-ice blasting

    NASA Astrophysics Data System (ADS)

    Dong, Shujuan; Song, Bo; Hansz, Bernard; Liao, Hanlin; Coddet, Christian

    2011-10-01

    Dry-ice blasting, as an environmental-friendly method, was introduced into atmospheric plasma spraying for improving properties of metallic, alloy and ceramic coatings. The deposited coatings were then compared with coatings plasma-sprayed using conventional air cooling in terms of microstructure, temperature, oxidation, porosity, residual stress and adhesion. It was found that a denser steel or CoNiCrAlY alloy coating with a lower content of oxide can be achieved with the application of dry-ice blasting during the plasma spraying. In addition, the adhesive strength of Al 2O 3 coating deposited with dry-ice blasting exceeded 60 MPa, which was nearly increased by 30% compared with that of the coating deposited with conventional air cooling. The improvement in properties of plasma-sprayed metallic, alloy and ceramic coatings caused by dry-ice blasting was attributed to the decrease of annulus-ringed disk like splats, the better cooling efficiency of dry-ice pellets and even the mechanical effect of dry-ice impact.

  7. SIB-BLAST: a web server for improved delineation of true and false positives in PSI-BLAST searches.

    PubMed

    Lee, Marianne M; Chan, Michael K; Bundschuh, Ralf

    2009-07-01

    A SIB-BLAST web server (http://sib-blast.osc.edu) has been established for investigators to use the SimpleIsBeautiful (SIB) algorithm for sequence-based homology detection. SIB was developed to overcome the model corruption frequently observed in the later iterations of PSI-BLAST searches. The algorithm compares resultant hits from the second iteration to the final iteration of a PSI-BLAST search, calculates the figure of merit for each 'overlapped' hit and re-ranks the hits according to their figure of merit. By validating hits generated from the last profile against hits from the first profile when the model is least corrupted, the true and false positives are better delineated, which in turn, improves the accuracy of iterative PSI-BLAST searches. Notably, this improvement to PSI-BLAST comes at minimal computational cost as SIB-BLAST utilizes existing results already produced in a PSI-BLAST search.

  8. Air Abrasion

    MedlinePlus

    ... delivered directly to your desktop! more... What Is Air Abrasion? Article Chapters What Is Air Abrasion? What Happens? The Pros and Cons Will I Feel Anything? Is Air Abrasion for Everyone? print full article print this ...

  9. Integrated Experimental Platforms to Study Blast Injuries: a Bottom-Up Approach

    NASA Astrophysics Data System (ADS)

    Bo, Chiara

    2013-06-01

    Developing a cellular and molecular understanding of the nature of traumatic and post-traumatic effects of blast events on live biological samples is critical for improving clinical outcomes.1 To investigate the consequences of pressure waves upon cellular structures and the underlying physiological and biochemical changes, we are using an integrated approach to study the material and biological properties of cells, tissues and organs when subjected to extreme conditions. In particular we have developed a confined Split Hopkinson Pressure Bar (SHPB) system, which allows us to subject cells in suspension or in a monolayer to compression waves of the order of few MPa and duration of hundreds of microseconds.2 The chamber design also enables recovery of the biological samples for cellular and molecular analysis. Specifically, cell survivability, viability, proliferation and morphological changes are investigated post compression for different cell populations. The SHPB platform, coupled with Quasi-Static experiments, is also used to determine stress-strain curves of soft biological tissues under compression at low, medium and high strain rates. Samples are also examined using histological techniques to study macro- and microscopical changes induced by compression waves. Finally, a shock tube has been developed to replicate primary blast damage on organs (i.e. mice lungs) and cell monolayers by generating single or multiple air blast of the order of kPa and few milliseconds duration. This platform allows us to visualize post-traumatic morphological changes at the cellular level as a function of the stimulus pressure and duration as well as biomarker signatures of blast injuries. Adapting and integrating a variety of approaches with different experimental platforms allows us to sample a vast pressure-time space in terms of biological and structural damage that mimic blast injuries and also to determine which physical parameters (peak pressure, stimulus duration, impulse

  10. 30 CFR 77.1910 - Explosives and blasting; general.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Explosives and blasting; general. 77.1910... COAL MINES Slope and Shaft Sinking § 77.1910 Explosives and blasting; general. (a) Light and power... explosive materials, detonators, and any other related blasting material employed in the development of...

  11. 30 CFR 75.1310 - Explosives and blasting equipment.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Explosives and blasting equipment. 75.1310... SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Explosives and Blasting § 75.1310 Explosives and blasting equipment. (a) Only permissible explosives, approved sheathed explosive units,...

  12. 30 CFR 816.64 - Use of explosives: Blasting schedule.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Use of explosives: Blasting schedule. 816.64... ACTIVITIES § 816.64 Use of explosives: Blasting schedule. (a) General requirements. (1) The operator shall... specific areas in which blasting will take place; (3) Dates and time periods when explosives are to...

  13. 30 CFR 816.64 - Use of explosives: Blasting schedule.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Use of explosives: Blasting schedule. 816.64... ACTIVITIES § 816.64 Use of explosives: Blasting schedule. (a) General requirements. (1) The operator shall... specific areas in which blasting will take place; (3) Dates and time periods when explosives are to...

  14. 30 CFR 816.64 - Use of explosives: Blasting schedule.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Use of explosives: Blasting schedule. 816.64... ACTIVITIES § 816.64 Use of explosives: Blasting schedule. (a) General requirements. (1) The operator shall... specific areas in which blasting will take place; (3) Dates and time periods when explosives are to...

  15. 30 CFR 77.1910 - Explosives and blasting; general.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Explosives and blasting; general. 77.1910... COAL MINES Slope and Shaft Sinking § 77.1910 Explosives and blasting; general. (a) Light and power... explosive materials, detonators, and any other related blasting material employed in the development of...

  16. 30 CFR 75.1310 - Explosives and blasting equipment.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Explosives and blasting equipment. 75.1310... SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Explosives and Blasting § 75.1310 Explosives and blasting equipment. (a) Only permissible explosives, approved sheathed explosive units,...

  17. 30 CFR 75.1310 - Explosives and blasting equipment.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Explosives and blasting equipment. 75.1310... SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Explosives and Blasting § 75.1310 Explosives and blasting equipment. (a) Only permissible explosives, approved sheathed explosive units,...

  18. 30 CFR 816.64 - Use of explosives: Blasting schedule.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Use of explosives: Blasting schedule. 816.64... ACTIVITIES § 816.64 Use of explosives: Blasting schedule. (a) General requirements. (1) The operator shall... specific areas in which blasting will take place; (3) Dates and time periods when explosives are to...

  19. 30 CFR 75.1310 - Explosives and blasting equipment.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Explosives and blasting equipment. 75.1310... SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Explosives and Blasting § 75.1310 Explosives and blasting equipment. (a) Only permissible explosives, approved sheathed explosive units,...

  20. 30 CFR 75.1310 - Explosives and blasting equipment.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Explosives and blasting equipment. 75.1310... SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Explosives and Blasting § 75.1310 Explosives and blasting equipment. (a) Only permissible explosives, approved sheathed explosive units,...

  1. 30 CFR 77.1910 - Explosives and blasting; general.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Explosives and blasting; general. 77.1910... COAL MINES Slope and Shaft Sinking § 77.1910 Explosives and blasting; general. (a) Light and power... explosive materials, detonators, and any other related blasting material employed in the development of...

  2. 30 CFR 816.64 - Use of explosives: Blasting schedule.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Use of explosives: Blasting schedule. 816.64... ACTIVITIES § 816.64 Use of explosives: Blasting schedule. (a) General requirements. (1) The operator shall... specific areas in which blasting will take place; (3) Dates and time periods when explosives are to...

  3. VIEW LOOKING NORTH, VIEW OF BLAST FURNACE NO. 2 (LEFT) ...

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

    VIEW LOOKING NORTH, VIEW OF BLAST FURNACE NO. 2 (LEFT) SHARING THE SAME CAST HOUSE WITH BLAST FURNACE NO. 1. ORE BRIDGE & BLOWER HOUSE TO RIGHT, HULETT CAR DUMPER IS IN LEFT FOREGROUND. - Pittsburgh Steel Company, Monessen Works, Blast Furnace No. 1 & No. 2, Donner Avenue, Monessen, Westmoreland County, PA

  4. 15. NORTHERN VIEW OF THE REMAINS OF BLAST FURNACE No. ...

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

    15. NORTHERN VIEW OF THE REMAINS OF BLAST FURNACE No. 2 IN LOWER CENTER OF PHOTO AT THE BASE OF HOT BLAST STOVES. HOIST HOUSE No. 2 IS ON THE LEFT. (Martin Stupich) - U.S. Steel Duquesne Works, Blast Furnace Plant, Along Monongahela River, Duquesne, Allegheny County, PA

  5. 30 CFR 75.1316 - Preparation before blasting.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Preparation before blasting. 75.1316 Section 75.1316 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Explosives and Blasting § 75.1316 Preparation before blasting. (a)(1)...

  6. Biomechanical assessment of brain dynamic responses due to blast pressure waves.

    PubMed

    Chafi, M S; Karami, G; Ziejewski, M

    2010-02-01

    A mechanized and integrated computational scheme is introduced to determine the human brain responses in an environment where the human head is exposed to explosions from trinitrotoluene (TNT), or other high-yield explosives, in military applications. The procedure is based on a three-dimensional (3-D) non-linear finite element method (FEM) that implements a simultaneous conduction of explosive detonation, shock wave propagation, blast-head interactions, and the confronting human head. The processes of blast propagation in the air and blast interaction with the head are modeled by an Arbitrary Lagrangian-Eulerian (ALE) multi-material FEM formulation, together with a penalty-based fluid/structure interaction (FSI) algorithm. Such a model has already been successfully validated against experimental data regarding air-free blast and plate-blast interactions. The human head model is a 3-D geometrically realistic configuration that has been previously validated against the brain intracranial pressure (ICP), as well as shear and principal strains under different impact loadings of cadaveric experimental tests of Hardy et al. [Hardy W. N., C. Foster, M. Mason, S. Chirag, J. Bishop, M. Bey, W. Anderst, and S. Tashman. A study of the response of the human cadaver head to impact. Proc. 51 ( st ) Stapp. Car Crash J. 17-80, 2007]. Different scenarios have been assumed to capture an appropriate picture of the brain response at a constant stand-off distance of nearly 80 cm from the core of the explosion, but exposed to different amounts of a highly explosive (HE) material such as TNT. The over-pressures at the vicinity of the head are in the range of about 2.4-8.7 atmosphere (atm), considering the reflected pressure from the head. The methodology provides brain ICP, maximum shear stresses and maximum principal strain within the milli-scale time frame of this highly dynamic phenomenon. While focusing on the two mechanical parameters of pressure, and also on the maximum shear

  7. Copper staves in the blast furnace

    SciTech Connect

    Helenbrook, R.G.; Kowalski, W.; Grosspietsch, K.H.; Hille, H.

    1996-08-01

    Operational data for stave cooling systems for two German blast furnaces show good correlation with predicted thermal results. Copper staves have been installed in blast furnaces in the zones exposed to the highest thermal loads. The good operational results achieved confirm the choice of copper staves in the areas of maximum heat load. Both temperature measurements and predictions establish that the MAN GHH copper staves do not experience large temperature fluctuations and that the hot face temperatures will be below 250 F. This suggests that the copper staves maintain a more stable accretion layer than the cast iron staves. Contrary to initial expectations, heat flux to the copper staves is 50% lower than that to cast iron staves. The more stable accretion layer acts as an excellent insulator for the stave and greatly reduces the number of times the hot face of the stave is exposed to the blast furnace process and should result in a more stable furnace operation. In the future, it may be unnecessary to use high quality, expensive refractories in front of copper staves because of the highly stable accretion layer that appears to rapidly form due to the lower operating temperature of the staves. There is a balance of application regions for cast iron and copper staves that minimizes the capital cost of a blast furnace reline and provides an integrated cooling system with multiple campaign life potential. Cast iron staves are proven cooling elements that are capable of multiple campaign life in areas of the blast furnace which do not experience extreme heat loads. Copper staves are proving to be an effective and reliable blast furnace cooling element that are subject to virtually no wear and are projected to have a longer campaign service life in the areas of highest thermal load in the blast furnace.

  8. Comment on "chronic traumatic encephalopathy in blast-exposed military veterans and a blast neurotrauma mouse model".

    PubMed

    Tsao, Jack W

    2012-10-24

    In their recent paper, Goldstein et al. show murine brain tau neuropathology after explosive blast with head rotation but do not present additional evidence that would delineate whether this neuropathology was principally caused by blast exposure alone or by blast exposure plus head rotational injury.

  9. Thermotechnical performance of an air-cooled tuyere with air cooling channels in series

    NASA Astrophysics Data System (ADS)

    Shen, Yuansheng; Zhou, Yuanyuan; Zhu, Tao; Duan, Guangbin

    2016-03-01

    To reduce the cooling air consumption for an air-cooled tuyere, an air-cooled tuyere with air cooling channels in series is developed based on several hypotheses, i.e., a transparent medium in the blast furnace, among others, and the related mathematical models are introduced and developed. Referring to the data from a BF site, the thermotechnical computation for the air-cooled tuyere was performed, and the results show that when the temperature of the inlet cooling air increases, the temperatures for the outlet cooling air, the outer surface of the tuyere, the walls of the air cooling channels and the center channel as well as the heat going into the center channel increase, but the heat absorbed by the cooling air flowing through the air cooling channels decreases. When the cooling air flow rate under the standard state increases, the physical parameters mentioned above change in an opposite directions. Compared to a water-cooled tuyere, the energy savings for an air-cooled tuyere are more than 0.23 kg/min standard coal.

  10. Computational modeling of human head under blast in confined and open spaces: primary blast injury.

    PubMed

    Rezaei, A; Salimi Jazi, M; Karami, G

    2014-01-01

    In this paper, a computational modeling for biomechanical analysis of primary blast injuries is presented. The responses of the brain in terms of mechanical parameters under different blast spaces including open, semi-confined, and confined environments are studied. In the study, the effect of direct and indirect blast waves from the neighboring walls in the confined environments will be taken into consideration. A 50th percentile finite element head model is exposed to blast waves of different intensities. In the open space, the head experiences a sudden intracranial pressure (ICP) change, which vanishes in a matter of a few milliseconds. The situation is similar in semi-confined space, but in the confined space, the reflections from the walls will create a number of subsequent peaks in ICP with a longer duration. The analysis procedure is based on a simultaneous interaction simulation of the deformable head and its components with the blast wave propagations. It is concluded that compared with the open and semi-confined space settings, the walls in the confined space scenario enhance the risk of primary blast injuries considerably because of indirect blast waves transferring a larger amount of damaging energy to the head. PMID:23996897

  11. 29 CFR 1926.906 - Initiation of explosive charges-electric blasting.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... are loaded. (c) In any single blast using electric blasting caps, all caps shall be of the same style... blast. (l) When firing from a power circuit, the firing switch shall be locked in the open or “Off...) After firing an electric blast from a blasting machine, the leading wires shall be...

  12. The blast wave mitigation effects of a magnetogasdynamic decelerator

    SciTech Connect

    Baty, Roy S; Lundgren, Ronald G; Tucker, Don H

    2009-01-01

    This work computes shock wave jump functions for viscous blast waves propagating in a magnetogasdynamic decelerator. The decelerator is assumed to be a one-dimensional channel with sides that are perfect conductors. An electric field applied on the walls of the channel produces a magnetogasdynamic pump, which decelerates the flow field induced by a blast wave. The blast wave jump functions computed here are compared to magnetogasdynamic results for steady supersonic channel flow to quantify potential blast mitigation effects. Theoretical shock wave jump functions are also presented for inviscid blast waves propagating in a one-dimensional channel with an electromagnetic field.

  13. The effect of explosive blast loading on human neuroblastoma cells.

    PubMed

    Zander, Nicole E; Piehler, Thuvan; Banton, Rohan; Boggs, Mary

    2016-07-01

    Diagnosis of mild to moderate traumatic brain injury is challenging because brain tissue damage progresses slowly and is not readily detectable by conventional imaging techniques. We have developed a novel in vitro model to study primary blast loading on dissociated neurons using nitroamine explosives such as those used on the battlefield. Human neuroblastoma cells were exposed to single and triple 50-psi explosive blasts and single 100-psi blasts. Changes in membrane permeability and oxidative stress showed a significant increase for the single and triple 100-psi blast conditions compared with single 50-psi blast and controls.

  14. Effectiveness of eye armor during blast loading.

    PubMed

    Bailoor, Shantanu; Bhardwaj, Rajneesh; Nguyen, Thao D

    2015-11-01

    Ocular trauma is one of the most common types of combat injuries resulting from the interaction of military personnel with improvised explosive devices. Ocular blast injury mechanisms are complex, and trauma may occur through various injury mechanisms. However, primary blast injuries (PBI) are an important cause of ocular trauma that may go unnoticed and result in significant damage to internal ocular tissues and visual impairment. Further, the effectiveness of commonly employed eye armor, designed for ballistic and laser protection, in lessening the severity of adverse blast overpressures (BOP) is unknown. In this paper, we employed a three-dimensional (3D) fluid-structure interaction computational model for assessing effectiveness of the eye armor during blast loading on human eyes and validated results against free field blast measurements by Bentz and Grimm (2013). Numerical simulations show that the blast waves focused on the ocular region because of reflections from surrounding facial features and resulted in considerable increase in BOP. We evaluated the effectiveness of spectacles and goggles in mitigating the pressure loading using the computational model. Our results corroborate experimental measurements showing that the goggles were more effective than spectacles in mitigating BOP loading on the eye. Numerical results confirmed that the goggles significantly reduced blast wave penetration in the space between the armor and the eyes and provided larger clearance space for blast wave expansion after penetration than the spectacles. The spectacles as well as the goggles were more effective in reducing reflected BOP at higher charge mass because of the larger decrease in dynamic pressures after the impact. The goggles provided greater benefit of reducing the peak pressure than the spectacles for lower charge mass. However, the goggles resulted in moderate, sustained elevated pressure loading on the eye, that became 50-100% larger than the pressure loading

  15. Effectiveness of eye armor during blast loading.

    PubMed

    Bailoor, Shantanu; Bhardwaj, Rajneesh; Nguyen, Thao D

    2015-11-01

    Ocular trauma is one of the most common types of combat injuries resulting from the interaction of military personnel with improvised explosive devices. Ocular blast injury mechanisms are complex, and trauma may occur through various injury mechanisms. However, primary blast injuries (PBI) are an important cause of ocular trauma that may go unnoticed and result in significant damage to internal ocular tissues and visual impairment. Further, the effectiveness of commonly employed eye armor, designed for ballistic and laser protection, in lessening the severity of adverse blast overpressures (BOP) is unknown. In this paper, we employed a three-dimensional (3D) fluid-structure interaction computational model for assessing effectiveness of the eye armor during blast loading on human eyes and validated results against free field blast measurements by Bentz and Grimm (2013). Numerical simulations show that the blast waves focused on the ocular region because of reflections from surrounding facial features and resulted in considerable increase in BOP. We evaluated the effectiveness of spectacles and goggles in mitigating the pressure loading using the computational model. Our results corroborate experimental measurements showing that the goggles were more effective than spectacles in mitigating BOP loading on the eye. Numerical results confirmed that the goggles significantly reduced blast wave penetration in the space between the armor and the eyes and provided larger clearance space for blast wave expansion after penetration than the spectacles. The spectacles as well as the goggles were more effective in reducing reflected BOP at higher charge mass because of the larger decrease in dynamic pressures after the impact. The goggles provided greater benefit of reducing the peak pressure than the spectacles for lower charge mass. However, the goggles resulted in moderate, sustained elevated pressure loading on the eye, that became 50-100% larger than the pressure loading

  16. Blasting response of the Eiffel Tower

    NASA Astrophysics Data System (ADS)

    Horlyck, Lachlan; Hayes, Kieran; Caetano, Ryan; Tahmasebinia, Faham; Ansourian, Peter; Alonso-Marroquin, Fernando

    2016-08-01

    A finite element model of the Eiffel Tower was constructed using Strand7 software. The model replicates the existing tower, with dimensions justified through the use of original design drawings. A static and dynamic analysis was conducted to determine the actions of the tower under permanent, imposed and wind loadings, as well as under blast pressure loads and earthquake loads due to an explosion. It was observed that the tower utilises the full axial capacity of individual members by acting as a `truss of trusses'. As such, permanent and imposed loads are efficiently transferred to the primary columns through compression, while wind loads induce tensile forces in the windward legs and compressive forces in the leeward. Under blast loading, the tower experienced both ground vibrations and blast pressures. Ground vibrations induced a negligibly small earthquake loading into the structure which was ignored in subsequent analyses. The blast pressure was significant, and a dynamic analysis of this revealed that further research is required into the damping qualities of the structure due to soil and mechanical properties. In the worst case scenario, the blast was assumed to completely destroy several members in the adjacent leg. Despite this weakened condition, it was observed that the tower would still be able to sustain static loads, at least for enough time for occupant evacuation. Further, an optimised design revealed the structure was structurally sound under a 46% reduction of the metal tower's mass.

  17. Modelling human eye under blast loading.

    PubMed

    Esposito, L; Clemente, C; Bonora, N; Rossi, T

    2015-01-01

    Primary blast injury (PBI) is the general term that refers to injuries resulting from the mere interaction of a blast wave with the body. Although few instances of primary ocular blast injury, without a concomitant secondary blast injury from debris, are documented, some experimental studies demonstrate its occurrence. In order to investigate PBI to the eye, a finite element model of the human eye using simple constitutive models was developed. The material parameters were calibrated by a multi-objective optimisation performed on available eye impact test data. The behaviour of the human eye and the dynamics of mechanisms occurring under PBI loading conditions were modelled. For the generation of the blast waves, different combinations of explosive (trinitrotoluene) mass charge and distance from the eye were analysed. An interpretation of the resulting pressure, based on the propagation and reflection of the waves inside the eye bulb and orbit, is proposed. The peculiar geometry of the bony orbit (similar to a frustum cone) can induce a resonance cavity effect and generate a pressure standing wave potentially hurtful for eye tissues.

  18. Modelling human eye under blast loading.

    PubMed

    Esposito, L; Clemente, C; Bonora, N; Rossi, T

    2015-01-01

    Primary blast injury (PBI) is the general term that refers to injuries resulting from the mere interaction of a blast wave with the body. Although few instances of primary ocular blast injury, without a concomitant secondary blast injury from debris, are documented, some experimental studies demonstrate its occurrence. In order to investigate PBI to the eye, a finite element model of the human eye using simple constitutive models was developed. The material parameters were calibrated by a multi-objective optimisation performed on available eye impact test data. The behaviour of the human eye and the dynamics of mechanisms occurring under PBI loading conditions were modelled. For the generation of the blast waves, different combinations of explosive (trinitrotoluene) mass charge and distance from the eye were analysed. An interpretation of the resulting pressure, based on the propagation and reflection of the waves inside the eye bulb and orbit, is proposed. The peculiar geometry of the bony orbit (similar to a frustum cone) can induce a resonance cavity effect and generate a pressure standing wave potentially hurtful for eye tissues. PMID:23521031

  19. Low-Cost Blast Wave Generator for Studies of Hearing Loss and Brain Injury: Blast Wave Effects in Closed Spaces

    PubMed Central

    Newman, Andrew J.; Hayes, Sarah H.; Rao, Abhiram S.; Allman, Brian L.; Manohar, Senthilvelan; Ding, Dalian; Stolzberg, Daniel; Lobarinas, Edward; Mollendorf, Joseph C.; Salvi, Richard

    2015-01-01

    Background Military personnel and civilians living in areas of armed conflict have increased risk of exposure to blast overpressures that can cause significant hearing loss and/or brain injury. The equipment used to simulate comparable blast overpressures in animal models within laboratory settings is typically very large and prohibitively expensive. New Method To overcome the fiscal and space limitations introduced by previously reported blast wave generators, we developed a compact, low-cost blast wave generator to investigate the effects of blast exposures on the auditory system and brain. Results The blast wave generator was constructed largely from off the shelf components, and reliably produced blasts with peak sound pressures of up to 198 dB SPL (159.3 kPa) that were qualitatively similar to those produced from muzzle blasts or explosions. Exposure of adult rats to 3 blasts of 188 dB peak SPL (50.4 kPa) resulted in significant loss of cochlear hair cells, reduced outer hair cell function and a decrease in neurogenesis in the hippocampus. Comparison to existing methods Existing blast wave generators are typically large, expensive, and are not commercially available. The blast wave generator reported here provides a low-cost method of generating blast waves in a typical laboratory setting. Conclusions This compact blast wave generator provides scientists with a low cost device for investigating the biological mechanisms involved in blast wave injury to the rodent cochlea and brain that may model many of the damaging effects sustained by military personnel and civilians exposed to intense blasts. PMID:25597910

  20. SWeBLAST: a Sliding Window Web-based BLAST tool for recombinant analysis.

    PubMed

    Fourment, Mathieu; Gibbs, Adrian J; Gibbs, Mark J

    2008-09-01

    We describe a simple Perl computer tool for matching successive subsequences of a query sequence using the BLAST facilities of Genbank. SWeBLAST helps identify 'parents' of recombinant sequences, even when these are themselves unrelated, thus it is complementary to methods that compare sets of aligned homologous sequences, and avoids the significant problem of these methods in having first to decide which sequences to compare. SWeBLAST searches may also be valuable for checking the recombination history of genes proposed for use as transgenes.

  1. Process control techniques for the Sidmar blast furnaces

    SciTech Connect

    Vandenberghe, D.; Bonte, L.; Nieuwerburgh, H. van

    1995-12-01

    The major challenge for modern blast furnace operation is the achievement of a very high productivity, excellent hot metal quality, low fuel consumption and longer blast furnace campaigns. The introduction of predictive models, decision supporting software and expert systems has reduced the standard deviation of the hot metal silicon content. The production loss due to the thermal state of the blast furnace has decreased three times since 1990. An appropriate control of the heat losses with high pulverized coal injection rates, is of the utmost importance for the life of the blast furnace. Different rules for the burden distribution of both blast furnaces are given. At blast furnace A, a peripheral gas flow is promoted, while at blast furnace B a more central gas flow is promoted.

  2. The design, implementation, and evaluation of mpiBLAST

    SciTech Connect

    Darling, A. E.; Carey, L.; Feng, W. C.

    2003-01-01

    mpiBLAST is an open-source parallelization of BLAST that achieves superlinear speed-up by segmenting a BLAST database and then having each node in a computational cluster search a unique portion of the database. Database segmentation permits each node to search a smaller portion of the database, eliminating disk I/O and vastly improving BLAST performance. Because database segmentation does not create heavy communication demands, BLAST users can take advantage of low-cost and efficient Linux cluster architectures such as the bladed Beowulf. In addition to presenting the software architecture of mpiBLAST we present a detailed performance analysis of mpiBLAST to demonstrate its scalability.

  3. Nineteen-Foot Diameter Explosively Driven Blast Simulator

    SciTech Connect

    VIGIL,MANUEL G.

    2001-07-01

    This report describes the 19-foot diameter blast tunnel at Sandia National Laboratories. The blast tunnel configuration consists of a 6 foot diameter by 200 foot long shock tube, a 6 foot diameter to 19 foot diameter conical expansion section that is 40 feet long, and a 19 foot diameter test section that is 65 feet long. Therefore, the total blast tunnel length is 305 feet. The development of this 19-foot diameter blast tunnel is presented. The small scale research test results using 4 inch by 8 inch diameter and 2 foot by 6 foot diameter shock tube facilities are included. Analytically predicted parameters are compared to experimentally measured blast tunnel parameters in this report. The blast tunnel parameters include distance, time, static, overpressure, stagnation pressure, dynamic pressure, reflected pressure, shock Mach number, flow Mach number, shock velocity, flow velocity, impulse, flow duration, etc. Shadowgraphs of the shock wave are included for the three different size blast tunnels.

  4. LTC American`s, Inc. vacuum blasting machine: Baseline report

    SciTech Connect

    1997-07-31

    The LTC shot blast technology was tested and is being evaluated at Florida International University (FIU) as a baseline technology. In conjunction with FIU`s evaluation of efficiency and cost, this report covers the evaluation conducted for safety and health issues. It is a commercially available technology and has been used for various projects at locations throughout the country. The LTC 1073 Vacuum Blasting Machine uses a high-capacity, direct-pressure blasting system which incorporates a continuous feed for the blast media. The blast media cleans the surface within the contained brush area of the blast. It incorporates a vacuum system which removes dust and debris from the surface as it is blasted. The safety and health evaluation during the testing focused on two main areas of exposure: dust and noise.

  5. Computation of blast wave-obstacle interactions

    NASA Technical Reports Server (NTRS)

    Champney, J. M.; Chaussee, D. S.; Kutler, P.

    1982-01-01

    Numerical simulations of the interaction of a planar blast wave with various obstacles are presented. These obstacles are either ground structures or vehicles flying in the atmosphere. For a structure on the ground, the blast wave encounter is side-on, while for the flying vehicles the encounter is either head-on or oblique. Second-order accurate, finite-difference, and shock-capturing procedures are employed to solve the two-dimensional, axisymmetric, and three-dimensional unsteady Euler equations. Results are presented for the flow field consisting of blast wave striking obstacles that are at rest, moving subsonically and moving supersonically. Comparison of the numerical results with experimental data for a configuration at rest substantiates the validity of this approach and its potential as a flow analysis tool.

  6. Isothermal blast wave model of supernova remnants

    NASA Technical Reports Server (NTRS)

    Solinger, A.; Buff, J.; Rappaport, S.

    1975-01-01

    The validity of the 'adiabatic' assumption in supernova-remnant calculations is examined, and the alternative extreme of an isothermal blast wave is explored. It is concluded that, because of thermal conductivity, the large temperature gradients predicted by the adiabatic model probably are not maintained in nature. Self-similar solutions to the hydrodynamic equations for an isothermal blast wave have been found and studied. These solutions are then used to determine the relationship between X-ray observations and inferred parameters of supernova remnants. A comparison of the present results with those for the adiabatic model indicates differences which are less than present observational uncertainties. It is concluded that most parameters of supernova remnants inferred from X-ray measurements are relatively insensitive to the specifics of the blast-wave model.

  7. The comminution theory applied to rock blasting

    SciTech Connect

    Agreda, C.

    1994-12-31

    A general review of the comminution theory and also the general differential equation of the comminution are described, analyzed and discussed in order to be applied to rock blasting. Some size distribution functions are reviewed and discussed to determine which of them represents better the cumulative low size distribution F(x) as a function of the nominal particle size (x), for the rock blasting fragmentation. Based on the mathematical comminution model presented, a formula to calculate the burden (B) is developed and discussed. A mathematical comminution model based on the strain energy and applied to an open pit rock blasting operation is developed, analyzed and discussed. The advantages of the mathematical comminution model presented in this paper are emphasized.

  8. Paint removal using wheat starch blast media

    NASA Astrophysics Data System (ADS)

    Foster, Terry; Oestreich, John

    1993-03-01

    A review of the Wheat Starch Blasting technology is presented. Laboratory evaluations covering Almen Arc testing on bare 2024-T3 aluminum and magnesium, as well as crack detection on 7075-T6 bare aluminum, are discussed. Comparisons with Type V plastic media show lower residual stresses are achieved on aluminum and magnesium with wheat starch media. Dry blasting effects on the detection of cracks confirms better crack visibility with wheat starch media versus Type V or Type II plastic media. Testing of wheat starch media in several composite test programs, including fiberglass, Kevlar, and graphite-epoxy composites, showed no fiber damage. Process developments and production experience at the first U.S. aircraft stripping facility are also reviewed. Corporate and regional aircraft are being stripped in this three nozzle dry blast hanger.

  9. OsGF14b Positively Regulates Panicle Blast Resistance but Negatively Regulates Leaf Blast Resistance in Rice.

    PubMed

    Liu, Qing; Yang, Jianyuan; Zhang, Shaohong; Zhao, Junliang; Feng, Aiqing; Yang, Tifeng; Wang, Xiaofei; Mao, Xinxue; Dong, Jingfang; Zhu, Xiaoyuan; Leung, Hei; Leach, Jan E; Liu, Bin

    2016-01-01

    Although 14-3-3 proteins have been reported to be involved in responses to biotic stresses in plants, their functions in rice blast, the most destructive disease in rice, are largely unknown. Only GF14e has been confirmed to negatively regulate leaf blast. We report that GF14b is highly expressed in seedlings and panicles during blast infection. Rice plants overexpressing GF14b show enhanced resistance to panicle blast but are susceptible to leaf blast. In contrast, GF14b-silenced plants show increased susceptibility to panicle blast but enhanced resistance to leaf blast. Yeast one-hybrid assays demonstrate that WRKY71 binds to the promoter of GF14b and modulates its expression. Overexpression of GF14b induces expression of jasmonic acid (JA) synthesis-related genes but suppresses expression of salicylic acid (SA) synthesis-related genes. In contrast, suppressed GF14b expression causes decreased expression of JA synthesis-related genes but activation of SA synthesis-related genes. These results suggest that GF14b positively regulates panicle blast resistance but negatively regulates leaf blast resistance, and that GF14b-mediated disease resistance is associated with the JA- and SA-dependent pathway. The different functions for 14-3-3 proteins in leaf and panicle blast provide new evidence that leaf and panicle blast resistance are controlled by different mechanisms. PMID:26467468

  10. OsGF14b Positively Regulates Panicle Blast Resistance but Negatively Regulates Leaf Blast Resistance in Rice.

    PubMed

    Liu, Qing; Yang, Jianyuan; Zhang, Shaohong; Zhao, Junliang; Feng, Aiqing; Yang, Tifeng; Wang, Xiaofei; Mao, Xinxue; Dong, Jingfang; Zhu, Xiaoyuan; Leung, Hei; Leach, Jan E; Liu, Bin

    2016-01-01

    Although 14-3-3 proteins have been reported to be involved in responses to biotic stresses in plants, their functions in rice blast, the most destructive disease in rice, are largely unknown. Only GF14e has been confirmed to negatively regulate leaf blast. We report that GF14b is highly expressed in seedlings and panicles during blast infection. Rice plants overexpressing GF14b show enhanced resistance to panicle blast but are susceptible to leaf blast. In contrast, GF14b-silenced plants show increased susceptibility to panicle blast but enhanced resistance to leaf blast. Yeast one-hybrid assays demonstrate that WRKY71 binds to the promoter of GF14b and modulates its expression. Overexpression of GF14b induces expression of jasmonic acid (JA) synthesis-related genes but suppresses expression of salicylic acid (SA) synthesis-related genes. In contrast, suppressed GF14b expression causes decreased expression of JA synthesis-related genes but activation of SA synthesis-related genes. These results suggest that GF14b positively regulates panicle blast resistance but negatively regulates leaf blast resistance, and that GF14b-mediated disease resistance is associated with the JA- and SA-dependent pathway. The different functions for 14-3-3 proteins in leaf and panicle blast provide new evidence that leaf and panicle blast resistance are controlled by different mechanisms.

  11. 30 CFR 817.66 - Use of explosives: Blasting signs, warnings, and access control.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... audible blast warning and all-clear signals that are in use, and which explain the marking of blasting... the blast shall be given. Each person within the permit area and each person who resides or...

  12. 30 CFR 816.66 - Use of explosives: Blasting signs, warnings, and access control.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... audible blast warning and all-clear signals that are in use, and which explain the marking of blasting... the blast shall be given. Each person within the permit area and each person who resides or...

  13. 30 CFR 816.66 - Use of explosives: Blasting signs, warnings, and access control.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... audible blast warning and all-clear signals that are in use, and which explain the marking of blasting... the blast shall be given. Each person within the permit area and each person who resides or...

  14. 30 CFR 816.66 - Use of explosives: Blasting signs, warnings, and access control.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... audible blast warning and all-clear signals that are in use, and which explain the marking of blasting... the blast shall be given. Each person within the permit area and each person who resides or...

  15. 30 CFR 816.66 - Use of explosives: Blasting signs, warnings, and access control.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... audible blast warning and all-clear signals that are in use, and which explain the marking of blasting... the blast shall be given. Each person within the permit area and each person who resides or...

  16. 30 CFR 816.66 - Use of explosives: Blasting signs, warnings, and access control.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... audible blast warning and all-clear signals that are in use, and which explain the marking of blasting... the blast shall be given. Each person within the permit area and each person who resides or...

  17. 30 CFR 817.66 - Use of explosives: Blasting signs, warnings, and access control.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... audible blast warning and all-clear signals that are in use, and which explain the marking of blasting... the blast shall be given. Each person within the permit area and each person who resides or...

  18. 30 CFR 817.66 - Use of explosives: Blasting signs, warnings, and access control.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... audible blast warning and all-clear signals that are in use, and which explain the marking of blasting... the blast shall be given. Each person within the permit area and each person who resides or...

  19. 30 CFR 817.66 - Use of explosives: Blasting signs, warnings, and access control.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... audible blast warning and all-clear signals that are in use, and which explain the marking of blasting... the blast shall be given. Each person within the permit area and each person who resides or...

  20. 30 CFR 817.66 - Use of explosives: Blasting signs, warnings, and access control.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... audible blast warning and all-clear signals that are in use, and which explain the marking of blasting... the blast shall be given. Each person within the permit area and each person who resides or...

  1. Blast noise impacts on sleep

    NASA Astrophysics Data System (ADS)

    Nykaza, Edward T.; Pater, Larry L.

    2005-04-01

    Firing large guns during the hours of darkness is essential to combat readiness for the military. At the same time most people are particularly sensitive to noise when sleeping or trying to fall asleep. Laboratory studies done by Griefahn [J. Sound and Vib. 128, 109-119 (1989)] and Luz [see Luz et al., ERDC/CERL, TR-04-26 (2004)] suggest that a time period at night may exist where people are more tolerant to large weapon impulse noise (blast noise) and therefore, are less likely to be awakened from noise events. In the fall of 2004, a field study was conducted around a military installation to determine if such a time period(s) exists. Noise monitors were set up inside and outside of residents homes to record noise levels from live military training activities and actimeters were worn by participants sleeping their natural environment to measure sleep disturbance and awakening. The method and results of this study will be presented. [Work supported by US Army Engineer Research and Development Center CERL.

  2. Assessment and treatment of common persistent sequelae following blast induced mild traumatic brain injury.

    PubMed

    Schultz, Billie A; Cifu, David X; McNamee, Shane; Nichols, Michelle; Carne, William

    2011-01-01

    The ongoing wars in Iraq and Afghanistan and terrorist activity worldwide have been associated with an increased incidence of blast injuries. While blast injuries share similarities with blunt or penetrating traumatic injuries, there are unique mechanistic elements of blast injury that create increased vulnerability to damage of specific organs. This review highlights the mechanism of blast-related injury, describes the common sequelae of blast exposure that may impact rehabilitation care, and summarizes the intervention strategies for these blast-related sequelae.

  3. Dynamic test of a corrugated steel keyworker blast shelter. Final report

    SciTech Connect

    Woodson, S.C.; Slawson, T.R.; Holmes, R.L.

    1986-05-01

    At the time this study was initiated, civil defense planning in the United States called for the evacuation of nonessential personnel to safe host areas when a nuclear attack is probable, requiring the construction of blast shelters to protect the key workers remaining in the risk areas. A full-scale corrugated steel keyworker blast shelter was dynamically tested using the High Explosive Simulation Technique (HEST). The test primarily investigated the structural design of the shelter and entryway, survivability of the air-moving system components, and occupant survivability. Alternate blast designs for the 18-man shelter were also tested. The test showed that the structure can withstand a 55-psi peak overpressure loading from a 1-MT nuclear detonation with only minor damage. In-structure shock was within acceptable limits for occupants. However, typical floor-mounted shelter equipment should be shock-isolated with pads to ensure survivability. Structural modifications to decrease the cost and increase the ease of installation of the structure are recommended.

  4. Operational aspects of F.16 plastic media blasting, as carried out by Fokker Aircraft Services

    NASA Astrophysics Data System (ADS)

    Pot, Frank

    1993-03-01

    In 1987, Fokker Aircraft Services started F.16 air-intake paint removal by means of Plastic Media Blasting (PMB). Especially for this process, a robot has been developed. In a later stage, complete exterior PMB-paint removal has been tested and successfully adopted. The paint removal is carried out in the scope of a thorough corrosion control program. The requirement that all the paint must be removed in order to allow this control program to be carried out properly, leads to severe masking complications. The process parameters are relatively conservative, because of the requirement that absolutely no anodic layer damage is permitted. Following PMB paint removal, corrosion is removed using aluminum oxide blasting. Finally, a highly flexible polyurethane paint system is applied, based upon TT-P-2760 Koroflex primer. To summarize the process, it can be stated that the plastic media blasting itself is straightforward. Proper masking is difficult to perform though, compounded by special customer requirements such as open panel edges.

  5. Experimental and Computational Study of Water Blast Mitigation Associated with Different Water Configurations

    NASA Astrophysics Data System (ADS)

    Zakrajsek, Andrew; Miklaszewski, Eric; Son, Steven

    2011-06-01

    An explosion yielding a shock wave is just one of the many threats the US faces. This threat can cause damage to equipment, structures, and cause significant risk to personnel. These threats define an immediate importance for understanding blast mitigation techniques via readily available mitigants. Specific blast mitigation techniques using water are being studied. Four fundamentally different water configurations are being considered. The fundamental mitigation mechanisms such as momentum transfer, large impedance differences, and evaporation are being explored. Laboratory testing using an explosively driven shock tube and a pressurized air shock tube are used for configurations including: solid water barriers, water sprays, water sheets, and individual droplets of water. Trends observed will be explained based on simulations coupled with known droplet breakup phenomena and analysis. We will report on experimental results and analysis, in addition to discussing the various blast mechanisms associated with each testing configuration. Funded by the Department of Homeland Security under the Center of Excellence for Explosive Detection, Mitigation and Response. Sponsor Award No. 080409/0002251.

  6. Evaluation of the performance of the blast analysis and measurement system

    NASA Astrophysics Data System (ADS)

    Luz, George A.

    2001-05-01

    In the years since the introduction of the C-weighted day-night average sound level (DNL) to assess the noise of military explosives, Army practice has evolved to incorporate linear peak sound-pressure level into the evaluation of military training noise. Although the DNL remains as the method of choice for National Environmental Policy Act (NEPA) documentation and for land-use planning, peak level is used by firing range operators for day-to-day complaint management. Several different monitoring system designs are being used at Army installations to provide range operators with real-time feedback on blast noise levels in nearby residential areas. One of these, the Blast Analysis and Measurement (BLAM) system, is a modified version of a sonic boom monitor designed by the U.S. Air Force. Data collected from two BLAM units located near a 120-mm tank gunnery range were evaluated in terms of hit rate and false-alarm rate over a range of 94 to 140 decibels linear peak. Hit- and false-alarm rates are compared with hit- and false-alarm rates reported for other blast noise monitoring system designs.

  7. Comparison of Internal-Blast Explosive Performance in Small- and Large-Scale Tests

    NASA Astrophysics Data System (ADS)

    Granholm, Richard

    2013-06-01

    Small-scale internal blast measurements were correlated with large-scale test data. Highly confined small explosive samples <0.5 g were subjected to the output from a PETN detonator while enclosed in a 3-liter chamber. Large-scale tests up to 22.7 kg were generally unconfined and shot in a 180-m3 chamber. When sample mass was expressed as total sample energy/chamber volume, theoretical peak quasi-static blast pressures for both small and large-scale tests fell on the same curve. Blast explosives may comprise high levels of fuels and reactive materials to enhance or control the release of energy, and may be insensitive and slow-reacting, with performance that may not scale well to small size tests. High confinement of a small sample can compensate for low sensitivity, but at the expense of heat loss to the metal confinement. This heat loss can be measured to improve the correlation between large and small-scale measurements, unless the released energy becomes too low to sustain complete reaction of the sample, either with itself or with air in the chamber.

  8. Ultrafast Fabry-Perot fiber-optic pressure sensors for multimedia blast event measurements.

    PubMed

    Zou, Xiaotian; Wu, Nan; Tian, Ye; Zhang, Yang; Fitek, John; Maffeo, Michael; Niezrecki, Christopher; Chen, Julie; Wang, Xingwei

    2013-02-20

    A shock wave (SW) is characterized as a large pressure fluctuation that typically lasts only a few milliseconds. On the battlefield, SWs pose a serious threat to soldiers who are exposed to explosions, which may lead to blast-induced traumatic brain injuries. SWs can also be used beneficially and have been applied to a variety of medical treatments due to their unique interaction with tissues and cells. Consequently, it is important to have sensors that can quantify SW dynamics in order to better understand the physical interaction between body tissue and the incident acoustic wave. In this paper, the ultrafast fiber-optic sensor based on the Fabry-Perot interferometric principle was designed and four such sensors were fabricated to quantify a blast event within different media, simultaneously. The compact design of the fiber-optic sensor allows for a high degree of spatial resolution when capturing the wavefront of the traveling SW. Several blast event experiments were conducted within different media (e.g., air, rubber membrane, and water) to evaluate the sensor's performance. This research revealed valuable knowledge for further study of SW behavior and SW-related applications. PMID:23434996

  9. Mathematical model and software for control of commissioning blast furnace

    NASA Astrophysics Data System (ADS)

    Spirin, N. A.; Onorin, O. P.; Shchipanov, K. A.; Lavrov, V. V.

    2016-09-01

    Blowing-in is a starting period of blast furnace operation after construction or major repair. The current approximation methods of blowing-in burden analysis are based on blowing-in practice of previously commissioned blast furnaces. This area is theoretically underexplored; there are no common scientifically based methods for selection of the burden composition and blast parameters. The purpose of this paper is development and scientific substantiation of the methods for selection of the burden composition and blast parameters in the blast furnace during the blowing-in period. Research methods are based on physical regularities of main processes running in the blast furnace, system analysis, and application of modern principles for development and construction of mathematical models, algorithms and software designed for automated control of complex production processes in metallurgy. As consequence of the research made by the authors the following results have been achieved: 1. A set of mathematical models for analysis of burden arrangement throughout the height of the blast furnace and for selection of optimal blast and gas dynamic parameters has been developed. 2. General principles for selection of the blowing-in burden composition and blast and gas dynamic parameters have been set up. 3. The software for the engineering and process staff of the blast furnace has been developed and introduced in the industry.

  10. Blast waves and how they interact with structures.

    PubMed

    Cullis, I G

    2001-02-01

    The paper defines and describes blast waves, their interaction with a structure and its subsequent response. Explosions generate blast waves, which need not be due to explosives. A blast wave consists of two parts: a shock wave and a blast wind. The paper explains how shock waves are formed and their basic properties. The physics of blast waves is non-linear and therefore non-intuitive. To understand how an explosion generates a blast wave a numerical modelling computer code, called a hydrocode has to be employed. This is briefly explained and the cAst Eulerian hydrocode is used to illustrate the formation and propagation of the blast wave generated by a 1 kg sphere of TNT explosive detonated 1 m above the ground. The paper concludes with a discussion of the response of a structure to a blast wave and shows that this response is governed by the structures natural frequency of vibration compared to the duration of the blast wave. The basic concepts introduced are illustrated in a second simulation that introduces two structures into the blast field of the TNT charge. PMID:11307674

  11. Coal combustion under conditions of blast furnace injection. [Quarterly] technical report, 1 December 1993--28 February 1994

    SciTech Connect

    Crelling, J.C.

    1994-06-01

    A potentially new use for Illinois coal is its use as a fuel injected into a blast furnace to produce molten iron as the first step in steel production. Because of its increasing cost and decreasing availability, metallurgical coke is now being replaced by coal injected at the tuyere area of the furnace where the blast air enters. The purpose of this study is to evaluate the combustion of coal during the blast furnace injection process and to delineate the optimum properties of the feed coal. This proposal is a follow-up to one funded for the 1992--1993 period. It is intended to complete the study already underway with the Armco Inc. Steel Company and to initiate a new cooperative study along somewhat similar lines with the Inland Steel Company. The results of this study will lead to the development of a testing and evaluation protocol that will give a unique and much needed understanding of the behavior of coal in the injection process and prove the potential of Illinois coals for such use. During this quarter a sample of the feed coal that is being used for injection into the No. 7 Blast Furnace of Inland Steel has been analyzed petrographically and compared to both the Herrin No. 6 coal and Armco feed coal. Additional characterization is underway and an advanced program of pyrolysis and reactivity testing has been initiated.

  12. Pilot plant testing of Illinois coal for blast furnace injection. Technical report, March 1--May 31, 1995

    SciTech Connect

    Crelling, J.C.

    1995-12-31

    A new use for Illinois coal is as fuel injected into a blast furnace to produce molten iron as first step in steel production. Because of cost and decreasing availability, metallurgical coke is being replaced by coal injected at the tuyere area of the furnace where the blast air enters. Purpose of this study is to evaluate combustion of Illinois coal in the blast furnace injection process in a pilot plant test facility. (Limited research to date suggests that coals of low fluidity and moderate to high S and Cl contents are suitable for blast furnace injection.) This proposal is intended to complete the study under way with Armco and Inland and to demonstrate quantitatively the suitability of Herrin No. 6 and Springfield No. 5 coals for injection. Main feature of current work is testing of Illinois coals at CANMET`s pilot plant coal combustion facility. During this quarter, two additional 300-pound samples of coal (IBCSP-110 Springfield No. 5 and an Appalachian coal) were delivered. Six Illinois Basin coals were analyzed with the CANMET model and compared with other bituminous coals from the Appalachians, France, Poland, South Africa, and Colombia. Based on computer modeling, lower rank bituminous coals, including coal from the Illinois Basin, compare well in injection with a variety of other bituminous coals.

  13. Numerical Modelling of Reinforced Concrete Slabs under Blast Loads of Close-in Detonations Using the Lagrangian Approach

    NASA Astrophysics Data System (ADS)

    Shuaib, M.; Daoud, O.

    2015-07-01

    This paper includes an investigation for the deformations, including deflections and damage modes, which occur in reinforced concrete (RC) slabs when subjected to blast loads of explosions. The slab considered for the investigation is a one-way square RC slab with the dimensions of 1000 x 1000 x 40 mm, fixed supported at two opposite sides. It was subjected to close-in detonations of three different charge weights for a constant standoff distance. For the study, the slab was analysed using the numerical method by means of nonlinear finite element analysis. The slab was modelled as 3-D structural continuum using LS-DYNA software. For concrete modelling, two constitutive models were selected, namely the KCC and Winfrith concrete models. Blast loads were applied to the slab through the Lagrangian approach, and the blast command available in the software, namely LOAD_BLAST_ENHANCED, was selected for the application. The deflections and damage modes results obtained were compared to those from a previously published experiment. From the study, both the KCC and Winfrith concrete models effectively and satisfactorily estimated the actual slab maximum deflection. For damage modes, the KCC model appeared to be capable to capture satisfactorily the general damage mode including flexural cracks. However, the model could not capture the local shear mode at the middle of slab (spallation) because the Lagrangian approach does not simulate the interaction between the ambient air and the solid slab.

  14. Air resources

    SciTech Connect

    1995-10-01

    This section describes the ambient (surrounding) air quality of the TVA region, discusses TVA emission contributions to ambient air quality, and identifies air quality impacts to human health and welfare. Volume 2 Technical Document 2, Environmental Consequences, describes how changes in TVA emissions could affect regional air quality, human health, environmental resources, and materials. The primary region of the affected environment is broadly defined as the state of Tennessee, as well as southern Kentucky, western Virginia, southern West Virginia, western North Carolina, and northern Georgia, Alabama, and Mississippi. This area represents the watershed of the Tennessee River and the 201 counties of the greater TVA service area. Emissions from outside the Tennessee Valley region contribute to air quality in the Valley. Also, TVA emissions are transported outside the Valley and have some impact on air quality beyond the primary study area. Although the study area experiences a number of air quality problems, overall air quality is good.

  15. Numerical study of water mitigation effects on blast wave

    NASA Astrophysics Data System (ADS)

    Cheng, M.; Hung, K. C.; Chong, O. Y.

    2005-11-01

    The mitigating effect of a water wall on the generation and propagation of blast waves of a nearby explosive has been investigated using a numerical approach. A multimaterial Eulerian finite element technique is used to study the influence of the design parameters, such as the water-to-explosive weight ratio, the water wall thickness, the air-gap and the cover area ratio of water on the effectiveness of the water mitigation concept. In the computational model, the detonation gases are modelled with the standard Jones Wilkins Lee (JWL) equation of state. Water, on the other hand, is treated as a compressible fluid with the Mie Gruneisen equation of state model. The validity of the computational model is checked against a limited amount of available experimental data, and the influence of mesh sizes on the convergence of results is also discussed. From the results of the extensive numerical experiments, it is deduced that firstly, the presence of an air-gap reduces the effectiveness of the water mitigator. Secondly, the higher the water-to-explosive weight ratio, the more significant is the reduction in peak pressure of the explosion. Typically, water-to-explosive weight ratios in the range of 1 3 are found to be most practical.

  16. A Novel Closed-Head Model of Mild Traumatic Brain Injury Using Focal Primary Overpressure Blast to the Cranium in Mice.

    PubMed

    Guley, Natalie H; Rogers, Joshua T; Del Mar, Nobel A; Deng, Yunping; Islam, Rafiqul M; D'Surney, Lauren; Ferrell, Jessica; Deng, Bowei; Hines-Beard, Jessica; Bu, Wei; Ren, Huiling; Elberger, Andrea J; Marchetta, Jeffrey G; Rex, Tonia S; Honig, Marcia G; Reiner, Anton

    2016-02-15

    Mild traumatic brain injury (TBI) from focal head impact is the most common form of TBI in humans. Animal models, however, typically use direct impact to the exposed dura or skull, or blast to the entire head. We present a detailed characterization of a novel overpressure blast system to create focal closed-head mild TBI in mice. A high-pressure air pulse limited to a 7.5 mm diameter area on the left side of the head overlying the forebrain is delivered to anesthetized mice. The mouse eyes and ears are shielded, and its head and body are cushioned to minimize movement. This approach creates mild TBI by a pressure wave that acts on the brain, with minimal accompanying head acceleration-deceleration. A single 20-psi blast yields no functional deficits or brain injury, while a single 25-40 psi blast yields only slight motor deficits and brain damage. By contrast, a single 50-60 psi blast produces significant visual, motor, and neuropsychiatric impairments and axonal damage and microglial activation in major fiber tracts, but no contusive brain injury. This model thus reproduces the widespread axonal injury and functional impairments characteristic of closed-head mild TBI, without the complications of systemic or ocular blast effects or head acceleration that typically occur in other blast or impact models of closed-skull mild TBI. Accordingly, our model provides a simple way to examine the biomechanics, pathophysiology, and functional deficits that result from TBI and can serve as a reliable platform for testing therapies that reduce brain pathology and deficits.

  17. Air Pollution.

    ERIC Educational Resources Information Center

    Gilpin, Alan

    A summary of one of our most pressing environmental problems, air pollution, is offered in this book by the Director of Air Pollution Control for the Queensland (Australia) State Government. Discussion of the subject is not restricted to Queensland or Australian problems and policies, however, but includes analysis of air pollution the world over.…

  18. Response of marine composites subjected to near field blast loading

    NASA Astrophysics Data System (ADS)

    LiVolsi, Frank

    Experimental studies were performed to understand the explosive response of composite panels when exposed to near-field explosive loading in different environments. The panel construction under consideration was an E-glass fiber-reinforced composite laminate infused with vinyl ester resin (Derakane 8084). The panel was layered bi-axially with plain-woven fiber orientations at 0° and 90°. Panel dimensions were approximately 203 mm x 203 mm x 1 mm (8 in x 8 in x 0.04 in). Experiments were carried out with the panel fully clamped in a holding fixture, which was in turn fastened inside a water tank. The fixture was fastened in such a way as to allow for explosive loading experiments in the following environments: water submersion with water backing, water submersion with air backing, and air immersion with air backing. Experiments were performed in room temperature conditions, and additional experiments in the submerged environments were also performed at high and low water temperatures of 40°C and 0°C, respectively. A stereo Digital Image Correlation (DIC) system was employed to capture the full-field dynamic behavior of the panel during the explosive event. Results indicated that the immersion environment contributes significantly to the blast response of the material and to the specimens' appreciable damage characteristics. The water submersion with air backing environment was found to encourage the greatest panel center point deflection and the most significant damage mechanisms around the boundary. The air immersion with air backing environment was found to encourage less center point deflection and exhibited significant impact damage from the explosive capsule. The water submersion with water backing environment encouraged the least panel deflection and minimal interlaminate damage around the panel boundary and center. Water temperature was found to influence the panel center point deflection, but not damage mechanisms. Maximum positive center point

  19. Dynamic Response of a Stiffened Laminated Composite Plate Subjected to Blast Load

    NASA Astrophysics Data System (ADS)

    Türkmen, H. S.; Mecitoğlu, Z.

    1999-04-01

    This paper is concerned with the experimental and numerical study of stiffened laminated composite plates exposed to a normal blast shock wave. For this purpose a detonation is developed from the reaction of LPG-O2mixtures in a long circular cylindrical shock tube. The detonation wave goes through into the atmosphere from the open end of the shock tube and acts as a blast load on the stiffened laminated composite plate which is placed in front of the detonation tube. Mounting of the target plate on a steel frame is designed with the object of providing clamped boundary conditions. The air blast pressure distribution is obtained by the use of quartz crystal pressure transducers placed on the wooden model. Strains are measured at the different points on the stiffened laminated composite plate and stiffener. In the experiment and analysis two different load cases are examined. Furthermore, a finite element modelling and analysis of the blast loaded stiffened composite plate are presented and the numerical results are compared with the experimental ones. An agreement is found between the experimental and finite element results in both linear and non-linear ranges. A good prediction is performed for the peak strain in the plate. However a discrepancy is shown between the measured and predicted strains on the stiffener because of the adhesive layer between the plate and stiffener. Prediction of the response frequency that has a great importance in the dynamic phenomena correlates well with the experimental results. The effects of stiffener and loading conditions on the dynamic behavior are examined. Large deformation effects are taken into account for the second loading condition.

  20. Air-Fed Visors Used for Isocyanate Paint Spraying--Potential Exposure When the Visor Is Lifted.

    PubMed

    Clayton, Mike; Baxter, Nick

    2015-11-01

    Continuous-flow air-supplied breathing apparatus with a visor is the respiratory protective equipment (RPE) of choice within the motor vehicle repair trade for protection against exposure to isocyanate paints. Whilst these devices are capable of providing adequate protection, a common workplace practice of sprayers lifting up the visor of their RPE immediately after spraying when checking the quality of the paint finish is thought to have an impact on the protection afforded. While the visor lift may be only for a few seconds, this action, especially if repeated numerous times during a work shift, could potentially result in a significant increase in exposure.Informal interviews with paint sprayers were conducted to understand the reasons for this behaviour followed by a series of laboratory tests to quantify the potential degree of exposure as a result of a visor lift.The majority of the paint sprayers interviewed explained their reasons for lifting their visors immediately after spraying and before the spray booth had been adequately cleared by ventilation. The main reasons given for a visor lift included a combination of habit, poor visibility due to poor visual clarity of the visor screen material, over spray, scratched visor screens, internal visor reflections, and poor booth lighting.The findings of the tests showed that the degree of protection provided by the visor when in the lifted position is in the approximate range of 1-3.7 (mean 1.7) and over the whole of the exposure period (from start of the lift to recovery of protection after refitting) is in the approximate range of 1.4-9.0 (mean 2.7). This is a significant reduction when compared to the assigned protection factor of 40 for this class of device and the measured protection factors of 5000-10 000 when worn correctly.These results clearly demonstrate that lifting the visor whilst still within a contaminated atmosphere considerably increases the wearer's exposure and that this is an example where

  1. Air-Fed Visors Used for Isocyanate Paint Spraying--Potential Exposure When the Visor Is Lifted.

    PubMed

    Clayton, Mike; Baxter, Nick

    2015-11-01

    Continuous-flow air-supplied breathing apparatus with a visor is the respiratory protective equipment (RPE) of choice within the motor vehicle repair trade for protection against exposure to isocyanate paints. Whilst these devices are capable of providing adequate protection, a common workplace practice of sprayers lifting up the visor of their RPE immediately after spraying when checking the quality of the paint finish is thought to have an impact on the protection afforded. While the visor lift may be only for a few seconds, this action, especially if repeated numerous times during a work shift, could potentially result in a significant increase in exposure.Informal interviews with paint sprayers were conducted to understand the reasons for this behaviour followed by a series of laboratory tests to quantify the potential degree of exposure as a result of a visor lift.The majority of the paint sprayers interviewed explained their reasons for lifting their visors immediately after spraying and before the spray booth had been adequately cleared by ventilation. The main reasons given for a visor lift included a combination of habit, poor visibility due to poor visual clarity of the visor screen material, over spray, scratched visor screens, internal visor reflections, and poor booth lighting.The findings of the tests showed that the degree of protection provided by the visor when in the lifted position is in the approximate range of 1-3.7 (mean 1.7) and over the whole of the exposure period (from start of the lift to recovery of protection after refitting) is in the approximate range of 1.4-9.0 (mean 2.7). This is a significant reduction when compared to the assigned protection factor of 40 for this class of device and the measured protection factors of 5000-10 000 when worn correctly.These results clearly demonstrate that lifting the visor whilst still within a contaminated atmosphere considerably increases the wearer's exposure and that this is an example where

  2. 30 CFR 58.610 - Abrasive blasting.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... miners shall use in accordance with 30 CFR 56.5005 or 57.5005 respirators approved for abrasive blasting by NIOSH under 42 CFR part 84, or the operation shall be performed in a totally enclosed device with the miner outside the device. (b) Underground areas of underground mines. Silica sand or...

  3. 30 CFR 58.610 - Abrasive blasting.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... miners shall use in accordance with 30 CFR 56.5005 or 57.5005 respirators approved for abrasive blasting by NIOSH under 42 CFR part 84, or the operation shall be performed in a totally enclosed device with the miner outside the device. (b) Underground areas of underground mines. Silica sand or...

  4. 30 CFR 58.610 - Abrasive blasting.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... miners shall use in accordance with 30 CFR 56.5005 or 57.5005 respirators approved for abrasive blasting by NIOSH under 42 CFR part 84, or the operation shall be performed in a totally enclosed device with the miner outside the device. (b) Underground areas of underground mines. Silica sand or...

  5. 30 CFR 58.610 - Abrasive blasting.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... miners shall use in accordance with 30 CFR 56.5005 or 57.5005 respirators approved for abrasive blasting by NIOSH under 42 CFR part 84, or the operation shall be performed in a totally enclosed device with the miner outside the device. (b) Underground areas of underground mines. Silica sand or...

  6. 30 CFR 58.610 - Abrasive blasting.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... miners shall use in accordance with 30 CFR 56.5005 or 57.5005 respirators approved for abrasive blasting by NIOSH under 42 CFR part 84, or the operation shall be performed in a totally enclosed device with the miner outside the device. (b) Underground areas of underground mines. Silica sand or...

  7. Blast-induced neurotrauma in whales.

    PubMed

    Knudsen, Siri K; Øen, Egil O

    2003-07-01

    A majority of investigations on primary blast injuries have focused on gas-containing organs, while the likelihood of blast-induced neurotrauma remains underrated. In Norway minke whales (Balaenoptera acutorostrata) are hunted using small fishing boats rigged with harpoon guns, which fire harpoons tipped with a grenade containing a charge of 30-g penthrite. The grenade detonates 60-70 cm inside the animal. The present study was undertaken to characterize the neuropathological changes caused by the penthrite blast and evaluate its role in the loss of consciousness and death in hunted whales. The study included 37 minke whales that were examined shipboard. The brains were later subjected to gross and light microscopy examination. The results showed that intra-body detonation of the grenade in near vicinity of the brain resulted in trauma similar to severe traumatic brain injury associated with a direct blow to the head. Detonation in more distant areas of the body resulted in injuries resembling acceleration-induced diffuse traumatic brain injury. The authors conclude that even if several vital organs were fatally injured in most whales, the neurotrauma induced by the blast-generated pressure waves were the primary cause for the immediate or very rapid loss of consciousness and death. PMID:12804799

  8. Characteristics and Mechanisms of Cardiopulmonary Injury Caused by Mine Blasts in Shoals: A Randomized Controlled Study in a Rabbit Model

    PubMed Central

    Han, Gengfen; Wang, Ziming; Wang, Jianmin; Yang, Weixiao; Chen, Jing; Kang, Jianyi; Zhang, Sen; Wang, Aimin; Lai, Xinan

    2013-01-01

    Background Because the characteristics of blast waves in water are different from those in air and because kinetic energy is liberated by a pressure wave at the water-air interface, thoracic injuries from mine blasts in shoals may be serious. The aim of the present study was to investigate the characteristics and mechanisms of cardiopulmonary injury caused by mine blasts in shoals. Methods To study the characteristics of cardiopulmonary injury, 56 animals were divided randomly into three experimental groups (12 animals in the sham group, 22 animals in the land group and 22 animals in the shoal group). To examine the biomechanics of injury, 20 animals were divided randomly into the land group and the shoal group. In the experimental model, the water surface was at the level of the rabbit's xiphoid process, and paper electric detonators (600 mg RDX) were used to simulate mines. Electrocardiography and echocardiography were conducted, and arterial blood gases, serum levels of cardiac troponin I and creatine kinase-MB and other physiologic parameters were measured over a 12-hour period after detonation. Pressures in the thorax and abdomen and the acceleration of the thorax were measured. Conclusion The results indicate that severe cardiopulmonary injury and dysfunction occur following exposure to mine blasts in shoals. Therefore, the mechanisms of cardiopulmonary injury may result from shear waves that produce strain at the water-air interface. Another mechanism of injury includes the propagation of the shock wave from the planta to the thorax, which causes a much higher peak overpressure in the abdomen than in the thorax; as a result, the abdominal organs and diaphragm are thrust into the thorax, damaging the lungs and heart. PMID:24358110

  9. Experimental study of blast mitigating devices based on combined construction

    NASA Astrophysics Data System (ADS)

    Takayama, K.; Silnikov, M. V.; Chernyshov, M. V.

    2016-09-01

    A robust blast inhibiting bin is the most often used device for damage blast effects suppression. In particular, a top open cylindrical bin significantly reduces a fragmentation effect resulted from a detonation of an explosive device placed inside the bin. However, reduction of blast wave overpressure and impulse by such cylindrical bins is not sufficient [1]. A reasonable alternative to endless increase of height and thickness of robust blast inhibiting bins is a development of destructible inhibitors having no solid elements in their structure and, therefore, excluding secondary fragmentation. So, the family of "Fountain" inhibitors [2,3] localizes and suppresses damaging blast effects due to multiphase working system. The present study is analyzing data obtained in testing of prototypes of new combined inhibitors. Their structure combines robust elements (bottoms, side surfaces) with elements responsible for blast loads reduction due to multi-phase working system (top and low transverse embeddings) and fairings impeding wave propagation in undesirable directions.

  10. Patterns in Blast Injuries to the Hand

    PubMed Central

    Buntic, Rudolf F.; Brooks, Darrell

    2008-01-01

    Blast injuries to the hand are not just a wartime phenomenon but also quite common in rural communities throughout northern California. The purpose of this study is to review our experience with blast injuries in the community and review the most common patterns in an attempt to identify the pathomechanics of the hand injury and the reconstructive procedures that are required. This is a retrospective study of blast injuries to the hand treated between 1978 and 2006. Medical records, X-rays, and photos were reviewed to compile standard patient demographics and characterize the injury pattern. Explosives were classified based on their rate of decomposition. Reconstructive solutions were reviewed and characterized based on whether damaged tissues were repaired or replaced. Sixty-two patients were identified with blast injuries to their hand. Patients were predominantly male (92%) with an average age of 27 years. Firecrackers were the most commonly encountered explosives. Thirty-seven patients were identified as holding a low explosive in their dominant hand and were used for characterization of the injury pattern. The apparent pattern of injury was hyperextension and hyperabduction of the hand and digits. Common injuries were metacarpophalangeal and interphalangeal joint hyperextension with associated soft tissue avulsion, hyperabduction at the web spaces with associated palmar soft tissue tears, and finger disarticulation amputations worse at radial digits. Given the mechanisms of injury with tissue loss, surgical intervention generally involved tissue replacement rather than tissue repair. Blast injuries to the hand represent a broad spectrum of injuries that are associated with the magnitude of explosion and probably, the proximity to the hand. We were able to identify a repetitive pattern of injury and demonstrate the predominant use for delayed tissue replacement rather than microsurgical repair at the acute setting. PMID:18780004

  11. Feasibility of cooling emplacement drifts by ventilation air and effects of pre-cooling intake air by refrigeration

    SciTech Connect

    Yang, Hang; Bhattacharyya, K.K.

    1995-12-01

    This study evaluates effects of applying refrigerated air to cool emplacement drifts and provides a preliminary basis for future design analyses. Evaluations include impacts of airflow rates, intake air temperature, ventilation systems capability, and effectiveness of pre-cooling. Representative results provided from this study include the heat removal capability of ventilation air, effects of refrigerating intake air on continuous cooling, and effects of refrigerating intake air on rapid (blast cooling). It is possible to cool emplacement drifts within a reasonable time period, using airflow at ambient temperature is reasonable quantity. Refrigerating intake air can significantly reduce required cooling time or airflow rate, but it is inefficient as far as power consumption is concerned.

  12. Development of heat-transfer circuits in the blast furnace

    NASA Astrophysics Data System (ADS)

    Spirin, N. A.; Yaroshenko, Yu G.; Lavrov, V. V.

    2016-09-01

    The development of heat-transfer circuits in the blast furnace as the technologies of blast-furnace smelting are improved are considered. It is shown that there are two zones of intense heat-transfer, and in modern conditions, when different kinds of iron ore are smelted, the use of combined blast with high parameters is a prerequisite for the stability of blastfurnace smelting operation and the smelting efficiency.

  13. Brain injury from explosive blast: description and clinical management.

    PubMed

    Ling, G; Ecklund, J M; Bandak, F A

    2015-01-01

    Accumulating clinical experience is indicating that explosive blast brain injury is becoming recognized as a disease distinct from the penetrating form of blast injury as well as the classic closed head injury (CHI). In recent US conflicts in Iraq and Afghanistan, over 60% of combat casualties were from explosive blast with the hallmark explosive weapon being the improvised explosive device (IED). Explosive blast TBI is a condition afflicting many combat injured warfighters potentially constituting another category of TBI. Clinically, it shares many features with conventional TBI but possesses some unique aspects. In its mild form, it also shares many clinical features with PTSD but here again has distinct aspects. Although military medical providers depend on civilian standard of care guidelines when managing explosive blast mTBI, they are continually adapting their medical practice in order to optimize the treatment of this disease, particularly in a theater of war. It is clear that further rigorous scientific study of explosive blast mTBI at both the basic science and clinical levels is needed. This research must include improved understanding of the causes and mechanisms of explosive blast TBI as well as comprehensive epidemiologic studies to determine the prevalence of this disease and its risk factors. A widely accepted unambiguous clinical description of explosive blast mTBI with diagnostic criteria would greatly improve diagnosis. It is hoped that through appropriate research meaningful prevention, mitigation, and treatment strategies for explosive blast mTBI can be speedily realized.

  14. 13. BUILDING NO. 621, INTERIOR, TOP OF BLASTING TUB UNDERNEATH ...

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

    13. BUILDING NO. 621, INTERIOR, TOP OF BLASTING TUB UNDERNEATH SAWDUST HOPPER. BLASTING TUB HAS DOUBLE WALLS OF 3/4' THICK STEEL ARMOR PLATE. CHARGE TO BE TESTED IS BURIED IN SAWDUST WITH FLAME RESISTANT CHEMICALS. ELEVATOR BEHIND TUB CARRIES SAWDUST BACK TO TOP OF SAWDUST HOPPER AFTER TEST IS COMPLETED AND SAWDUST IN BLASTING TUB HAS BEEN SIFTED FOR SHELL FRAGMENTS. LOUVERS IN WALLS ARE HINGED FREELY SO THEY OPEN TO RELIEVE BLAST PRESSURE DURING A TEST. - Picatinny Arsenal, 600 Area, Test Areas District, State Route 15 near I-80, Dover, Morris County, NJ

  15. Transient changes in neuronal cell membrane permeability after blast exposure.

    PubMed

    Arun, Peethambaran; Abu-Taleb, Rania; Valiyaveettil, Manojkumar; Wang, Ying; Long, Joseph B; Nambiar, Madhusoodana P

    2012-04-18

    The biochemical mechanisms of explosive blast-induced traumatic brain injury and the subsequent long-term neurobehavioral abnormalities are still not completely understood. We studied the biochemical mechanism of blast traumatic brain injury using our recently reported in-vitro model system with a shock tube. Primary blast exposure of in-vitro models leads to neurobiological changes in an overpressure dose-dependent and time-dependent manner. Lactate dehydrogenase was released significantly into the extracellular medium without cell death after blast exposure, indicating compromised cell membrane integrity. We further explored the integrity of cell membrane after blast exposure by fluorescent dye uptake/release techniques in SH-SY5Y human neuroblastoma cells. Our data indicate that blast exposure leads to an overpressure-dependent transient increase in the release of preloaded calcein AM into the culture medium with proportional intracellular decrease. Uptake of an extracellular nucleic acid-binding dye TO-PRO-3 iodide was also increased significantly after blast exposure, indicating that the increased molecular transport is bidirectional and nuclear membrane integrity is also affected by blast exposure. These results suggest that blast exposure perturbs the integrity of the neuronal cell membrane, leading to increased bidirectional transport of molecules--a potential mechanism that can lead to traumatic brain injury.

  16. Waveform analysis in mitigation of blast-induced vibrations

    NASA Astrophysics Data System (ADS)

    Aldas, G. G. U.; Ecevitoglu, B.

    2008-10-01

    To mitigate the blast-induced ground vibrations, we proposed a new methodology quite different from conventional methods which do not take into account the mechanics of seismic waves. Contrary to conventional methods, the proposed methodology does not consider any blast-parameters such as explosive types and amounts, blast-geometry, blast-hole design, hole-depth/diameter, etc., except time-delays. The methodology aims to employ the most suitable time-delays among blast-hole groupings to minimize destructive interference of the surface waves at the location of blast-induced vibrations. The crucial point of the proposed methodology is the use of a pilot-blast signal which takes account of the seismic properties of all complex geology between the blast and the target locations. Therefore, it does not require any geological model or assumption. The methodology has been implemented at a Turkish Coal Company's Lignite Mine. Blasting induced ground vibrations at this mine could be minimized to a ratio of 1/8.

  17. Indoor human response to blast sounds that generate rattles.

    PubMed

    Schomer, P D; Averbuch, A

    1989-08-01

    The two major noise sources that cause environmental problems for the U. S. Army are helicopters and large weapons such as artillery, tanks, and demolition. These large weapons produce blast sounds that contain little energy above 200 Hz and that are particularly troublesome to deal with because they excite rattles in structures. The purpose of this study was to systematically test subjective response to the presence or absence of rattles in otherwise similar blast sound environments. A second purpose of the study was to test if there were structural changes that could reduce annoyance within the indoor blast sound environment. This study was done using a specially constructed test house and highly repeatable shake table to generate the blast sounds. The data clearly show that no commonly used environmental noise measure adequately describes the indoor environment when the blast excites rattles. Although the indoor blast ASEL changes by only about a decibel or so (and the indoor blast CSEL changes by even less), the subjective response changes by up to 13 dB. At low blast levels, the increase in human annoyance response is largest, and this annoyance response offset decreases to about 6 dB when the outside, flat-weighted peak sound-pressure level of the blast increases from 112 to 122 dB. PMID:2768676

  18. On the Interaction and Coalescence if Spherical Blast Waves

    NASA Technical Reports Server (NTRS)

    Kandula, Max; Freeman, Robert J.

    2005-01-01

    The scaling and similarity laws concerning the propagation of isolated spherical blast waves are briefly reviewed. Both point source explosions and high pressure gas explosions are considered. Test data on blast overpressure from the interaction and coalescence of spherical blast waves emanating from explosives in the form of shaped charges of different strength placed in the vicinity of a solid propellant stack are presented. These data are discussed with regard to the scaling laws concerning the decay of blast overpressure. The results point out the possibility of detecting source explosions from far-field pressure measurements.

  19. Mechanisms of hearing loss after blast injury to the ear.

    PubMed

    Cho, Sung-Il; Gao, Simon S; Xia, Anping; Wang, Rosalie; Salles, Felipe T; Raphael, Patrick D; Abaya, Homer; Wachtel, Jacqueline; Baek, Jongmin; Jacobs, David; Rasband, Matthew N; Oghalai, John S

    2013-01-01

    Given the frequent use of improvised explosive devices (IEDs) around the world, the study of traumatic blast injuries is of increasing interest. The ear is the most common organ affected by blast injury because it is the body's most sensitive pressure transducer. We fabricated a blast chamber to re-create blast profiles similar to that of IEDs and used it to develop a reproducible mouse model to study blast-induced hearing loss. The tympanic membrane was perforated in all mice after blast exposure and found to heal spontaneously. Micro-computed tomography demonstrated no evidence for middle ear or otic capsule injuries; however, the healed tympanic membrane was thickened. Auditory brainstem response and distortion product otoacoustic emission threshold shifts were found to be correlated with blast intensity. As well, these threshold shifts were larger than those found in control mice that underwent surgical perforation of their tympanic membranes, indicating cochlear trauma. Histological studies one week and three months after the blast demonstrated no disruption or damage to the intra-cochlear membranes. However, there was loss of outer hair cells (OHCs) within the basal turn of the cochlea and decreased spiral ganglion neurons (SGNs) and afferent nerve synapses. Using our mouse model that recapitulates human IED exposure, our results identify that the mechanisms underlying blast-induced hearing loss does not include gross membranous rupture as is commonly believed. Instead, there is both OHC and SGN loss that produce auditory dysfunction.

  20. Mechanisms of Hearing Loss after Blast Injury to the Ear

    PubMed Central

    Cho, Sung-Il; Gao, Simon S.; Xia, Anping; Wang, Rosalie; Salles, Felipe T.; Raphael, Patrick D.; Abaya, Homer; Wachtel, Jacqueline; Baek, Jongmin; Jacobs, David; Rasband, Matthew N.; Oghalai, John S.

    2013-01-01

    Given the frequent use of improvised explosive devices (IEDs) around the world, the study of traumatic blast injuries is of increasing interest. The ear is the most common organ affected by blast injury because it is the body’s most sensitive pressure transducer. We fabricated a blast chamber to re-create blast profiles similar to that of IEDs and used it to develop a reproducible mouse model to study blast-induced hearing loss. The tympanic membrane was perforated in all mice after blast exposure and found to heal spontaneously. Micro-computed tomography demonstrated no evidence for middle ear or otic capsule injuries; however, the healed tympanic membrane was thickened. Auditory brainstem response and distortion product otoacoustic emission threshold shifts were found to be correlated with blast intensity. As well, these threshold shifts were larger than those found in control mice that underwent surgical perforation of their tympanic membranes, indicating cochlear trauma. Histological studies one week and three months after the blast demonstrated no disruption or damage to the intra-cochlear membranes. However, there was loss of outer hair cells (OHCs) within the basal turn of the cochlea and decreased spiral ganglion neurons (SGNs) and afferent nerve synapses. Using our mouse model that recapitulates human IED exposure, our results identify that the mechanisms underlying blast-induced hearing loss does not include gross membranous rupture as is commonly believed. Instead, there is both OHC and SGN loss that produce auditory dysfunction. PMID:23840874

  1. Transport and preparation of coke for the blast furnace

    SciTech Connect

    Kotov, A.P.; Ulakhovich, V.A.; Solodkov, V.I.; Mishin, E.N.; Chuparev, E.F.; Veshchezerov, M.M.; Shkodkin, K.K.

    1982-01-01

    In order to develop specifications for coke qualaity for large blast furnaces and measures matching the coke quality to the blast furnace volume, a series of investigations were conducted on the change in the physical and mechanical properties of coke in the process of its transport to the blast furnace, with a comparative evalution of the individual coke fractions. It was determined that the 60-40 and 80-60 mm coke classes were most suitable for blast furnace smelting. The 40-25 mm coke fraction is inferior in its physical and mechanical properties to these classes, but preferable to the over 80 mm coke. (JMT)

  2. Brain injury from explosive blast: description and clinical management.

    PubMed

    Ling, G; Ecklund, J M; Bandak, F A

    2015-01-01

    Accumulating clinical experience is indicating that explosive blast brain injury is becoming recognized as a disease distinct from the penetrating form of blast injury as well as the classic closed head injury (CHI). In recent US conflicts in Iraq and Afghanistan, over 60% of combat casualties were from explosive blast with the hallmark explosive weapon being the improvised explosive device (IED). Explosive blast TBI is a condition afflicting many combat injured warfighters potentially constituting another category of TBI. Clinically, it shares many features with conventional TBI but possesses some unique aspects. In its mild form, it also shares many clinical features with PTSD but here again has distinct aspects. Although military medical providers depend on civilian standard of care guidelines when managing explosive blast mTBI, they are continually adapting their medical practice in order to optimize the treatment of this disease, particularly in a theater of war. It is clear that further rigorous scientific study of explosive blast mTBI at both the basic science and clinical levels is needed. This research must include improved understanding of the causes and mechanisms of explosive blast TBI as well as comprehensive epidemiologic studies to determine the prevalence of this disease and its risk factors. A widely accepted unambiguous clinical description of explosive blast mTBI with diagnostic criteria would greatly improve diagnosis. It is hoped that through appropriate research meaningful prevention, mitigation, and treatment strategies for explosive blast mTBI can be speedily realized. PMID:25702216

  3. Mechanisms and Treatment of Blast Induced Hearing Loss

    PubMed Central

    2012-01-01

    The main objective of this study is to provide an overview of the basic mechanisms of blast induced hearing loss and review pharmacological treatments or interventions that can reduce or inhibit blast induced hearing loss. The mechanisms of blast induced hearing loss have been studied in experimental animal models mimicking features of damage or injury seen in human. Blast induced hearing loss is characterized by perforation and rupture of the tympanic membrane, ossicular damage, basilar membrane damage, inner and outer hair cell loss, rupture of round window, changes in chemical components of cochlear fluid, vasospasm, ischemia, oxidative stress, excitotoxicity, hematoma, and hemorrhage in both animals and humans. These histopathological consequences of blast exposure can induce hearing loss, tinnitus, dizziness, and headache. The pharmacological approaches to block or inhibit some of the auditory pathological consequences caused by blast exposure have been developed with antioxidant drugs such as 2,4-disulfonyl α-phenyl tertiary butyl nitrone (HXY-059, now called HPN-07) and N-acetylcysteine (NAC). A combination of antioxidant drugs (HPN-07 and NAC) was administered to reduce blast induced cochlear damage and hearing loss. The combination of the antioxidant drugs can prevent or treat blast induced hearing loss by reducing damage to the mechanical and neural component of the auditory system. Although information of the underlying mechanisms and treatment of blast induced hearing loss are provided, further and deep research should be achieved due to the limited and controversial knowledge. PMID:24653882

  4. Atomizing characteristics of swirl can combustor modules with swirl blast fuel injectors. [in terms of NOX emission rate

    NASA Technical Reports Server (NTRS)

    Ingebo, R. D.

    1980-01-01

    Cold flow atomization tests of several different designs of swirl can combustor modules were conducted in a 7.6 cm diameter duct at airflow rates (per unit area) of 7.3 to 25.7 g/sq cm sec and water flow rates of 6.3 to 18.9 g/sec. The effect of air and water flow rates on the mean drop size of water sprays produced with the swirl blast fuel injectors were determined. Also, from these data it was possible to determine the effect of design modifications on the atomizing performance of various fuel injector and air swirler configurations. The trend in atomizing performance, as based on the mean drop size, was then compared with the trends in the production of nitrogen oxides obtained in combustion studues with the same swirl can combustors. It was found that the fuel injector design that gave the best combustor performance in terms of a low NOx emission index also gave the best atomizing performance as characterized by a spray of relatively small mean drop diameter. It was also demonstrated that at constant inlet air stream momentum the nitrogen oxides emission index was found to vary inversely with the square of the mean drop diameter of the spray produced by the different swirl blast fuel injectors. Test conditions were inlet air static pressures of 100,000 to 200,000 N/sq m at an inlet air temperature of 293 K.

  5. Performance assessment of conventional and base-isolated nuclear power plants for earthquake and blast loadings

    NASA Astrophysics Data System (ADS)

    Huang, Yin-Nan

    to evaluate the vulnerability of the conventional and base-isolated NPP reactor buildings. The seismic performance assessment confirms the utility of seismic isolation at reducing spectral demands on secondary systems. Procedures to reduce the construction cost of secondary systems in isolated reactor buildings are presented. A blast assessment of the sample reactor building is performed for an assumed threat of 2000 kg of TNT explosive detonated on the surface with a closest distance to the reactor building of 10 m. The air and ground shock waves produced by the design threat are generated and used for performance assessment. The air blast loading to the sample reactor building is computed using a Computational Fluid Dynamics code Air3D and the ground shock time series is generated using an attenuation model for soil/rock response. Response-history analysis of the sample conventional and base isolated reactor buildings to external blast loadings is performed using the hydrocode LS-DYNA. The spectral demands on the secondary systems in the isolated reactor building due to air blast loading are greater than those for the conventional reactor building but much smaller than those spectral demands associated with Safe Shutdown Earthquake shaking. The isolators are extremely effective at filtering out high acceleration, high frequency ground shock loading.

  6. A computational study on brain tissue under blast: primary and tertiary blast injuries.

    PubMed

    Rezaei, A; Salimi Jazi, M; Karami, G; Ziejewski, M

    2014-08-01

    In this paper, a biomechanical study of a human head model exposed to blast shock waves followed by a blunt impact with the surface of the enclosing walls of a confined space is carried out. Under blast, the head may experience primary blast injury (PBI) due to exposure to the shockwaves and tertiary blast injury (TeBI) due to a possible blunt impact. We examine the brain response data in a deformable finite element head model in terms of the inflicted stress/pressure, velocity, and acceleration on the brain for several blast scenarios with different intensities. The data will be compared for open space and confined spaces. Following the initial impact of the shock front in the confined space, one can see the fluctuations in biomechanical data due to wave reflections. Although the severity of the PBI and TeBI is dependent on the situation, for the cases studied here, PBI is considerably more pronounced than TeBI in confined spaces. PMID:24515869

  7. Characterization and dispersion of pollutant releases from the abrasive blasting of lead paint from steel bridges

    SciTech Connect

    Lee, M.; Rana, B.

    1999-07-01

    The characterization of airborne and spent material for abrasive blasting of steel paint was performed as part of the Environmental Impact Statement for Lead Paint Removal Operations on New York City Department of Transportation Bridges1. Laboratory tests were performed on painted steel components of the Williamsburg Bridge, to determine the sizes of particles typically released into the air as aerosol and onto the ground as bulk material, as a result of accidental releases from abrasive blasting operations. Two of the most commonly used abrasives for paint removal on steel structures, recyclable steel grit and expendable abrasives were subjected to the laboratory tests. The results of the tests were used to determine the percentage of existing paint and abrasive which becomes airborne and the resultant particle size distributions, which were employed in the air quality concentration and deposition modeling for the EIS. Particle size distributions of the airborne material indicated that the profiles of airborne lead and particulate matter have a mean particle size between 15 and 21 microns. Spent abrasives and paint chips that settle on the floor are larger in size with a mean diameter greater than 259 microns, although up to 6% of this material has a mean diameter less than 50 microns. The percentage of paint and expendable abrasives that become airborne as a result of abrasive blasting were estimated to be as high as 9.0 and 12.4%, respectively. Potential release rates were derived for total accumulation (duration of the project), annual, quarterly, 24-hour, and 1-hour time averaging periods for abrasives, lead, and other metals. Pollutant releases were simulated as individual sources at multiple release heights with the Environment Protection Agency's ISC3ST model for six representative bridges near potential places of public exposure.

  8. 30 CFR 816.68 - Use of explosives: Records of blasting operations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... retain a record of all blasts for at least 3 years. Upon request, copies of these records shall be made... following data: (a) Name of the operator conducting the blast. (b) Location, date, and time of the blast. (c) Name, signature, and certification number of the blaster conducting the blast. (d)...

  9. 30 CFR 816.68 - Use of explosives: Records of blasting operations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... retain a record of all blasts for at least 3 years. Upon request, copies of these records shall be made... following data: (a) Name of the operator conducting the blast. (b) Location, date, and time of the blast. (c) Name, signature, and certification number of the blaster conducting the blast. (d)...

  10. 30 CFR 817.68 - Use of explosives: Records of blasting operations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... retain a record of all blasts for at least 3 years. Upon request, copies of these records shall be made... following data: (a) Name of the operator conducting the blast. (b) Location, date, and time of the blast. (c) Name, signature, and certification number of the blaster conducting the blast. (d)...

  11. 30 CFR 817.68 - Use of explosives: Records of blasting operations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... retain a record of all blasts for at least 3 years. Upon request, copies of these records shall be made... following data: (a) Name of the operator conducting the blast. (b) Location, date, and time of the blast. (c) Name, signature, and certification number of the blaster conducting the blast. (d)...

  12. 30 CFR 816.68 - Use of explosives: Records of blasting operations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... retain a record of all blasts for at least 3 years. Upon request, copies of these records shall be made... following data: (a) Name of the operator conducting the blast. (b) Location, date, and time of the blast. (c) Name, signature, and certification number of the blaster conducting the blast. (d)...

  13. 30 CFR 817.68 - Use of explosives: Records of blasting operations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... retain a record of all blasts for at least 3 years. Upon request, copies of these records shall be made... following data: (a) Name of the operator conducting the blast. (b) Location, date, and time of the blast. (c) Name, signature, and certification number of the blaster conducting the blast. (d)...

  14. 29 CFR 1926.906 - Initiation of explosive charges-electric blasting.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 8 2014-07-01 2014-07-01 false Initiation of explosive charges-electric blasting. 1926.906... Use of Explosives § 1926.906 Initiation of explosive charges—electric blasting. (a) Electric blasting caps shall not be used where sources of extraneous electricity make the use of electric blasting...

  15. Hydrodynamic Instabilities in Blast-Driven Systems

    NASA Astrophysics Data System (ADS)

    Henry de Frahan, Marc; Johnsen, Eric

    2014-11-01

    Mixing from hydrodynamics instabilities such as Richtmyer-Meshkov, Rayleigh-Taylor, and Kelvin-Helmholtz, occurs in a wide range of engineering applications such as inertial confinement fusion, supernova collapse, and scramjet combustion. The success of these applications depends on an accurate understanding of these phenomena. Following previous work investigating hydrodynamic mixing from the interaction of a perturbed interface with a planar blast wave, we model the perturbation growth by analyzing the different acceleration phases of a blast wave: an instantaneous acceleration (a pressure increase) followed by a gradual, time-dependent deceleration (a pressure decrease). Depending on the characteristics of these phases, the instability will be dominated by Richtmyer-Meshkov or Rayleigh-Taylor growth. We use a high-order accurate Discontinuous Galerkin method that prevents pressure errors at interfaces with variable specific heats ratios to simulate these systems and understand the different growth regimes.

  16. Blast Dynamics in a Dissipative Gas.

    PubMed

    Barbier, M; Villamaina, D; Trizac, E

    2015-11-20

    The blast caused by an intense explosion has been extensively studied in conservative fluids, where the Taylor-von Neumann-Sedov hydrodynamic solution is a prototypical example of self-similarity driven by conservation laws. In dissipative media, however, energy conservation is violated, yet a distinctive self-similar solution appears. It hinges on the decoupling of random and coherent motion permitted by a broad class of dissipative mechanisms. This enforces a peculiar layered structure in the shock, for which we derive the full hydrodynamic solution, validated by a microscopic approach based on molecular dynamics simulations. We predict and evidence a succession of temporal regimes, as well as a long-time corrugation instability, also self-similar, which disrupts the blast boundary. These generic results may apply from astrophysical systems to granular gases, and invite further cross-fertilization between microscopic and hydrodynamic approaches of shock waves.

  17. Modeling of aqueous foam blast wave attenuation

    NASA Astrophysics Data System (ADS)

    Del Prete, E.; Chinnayya, A.; Hadjadj, A.; Domergue, L.; Haas, J.-F.; Imbert, B.

    The use of aqueous foams enables the mitigation of blast waves induced by the explosion of energetic materials. The two-phase confinement gives rise to interphase interactions between the gaseous and liquid phases, which role have been emphasized in shock-tube studies with solid foams [1, 2]. Multifluid formalism enables the thermo-mechanical disequilibria between phases to be taken into account. The flow model ensures the correct estimation of the acoustic impedance of the two-phase media. As for the numerical scheme, Riemann solvers are used to describe the microscopic fluid interactions, the summation of which provides the multiphase flux. The role of the different transfer mechanisms is evaluated in the case where the liquid ligaments of the foam matrix have been shattered into droplets by the shock impingement. Characteristics of blast waves in heterogeneous media leads to a decrease of overpressure. The numerical results have been compared favorably to experimental data [3, 4].

  18. Blasting-induced damage in coal

    SciTech Connect

    Kabongo, K.K.

    1995-12-31

    The paper is drawn from a project intended to explore a technique of prediction, control and optimization of fracture in coal induced by blasting. It evaluates the fines generated in coal submitted to dynamic loading stresses in an impact stamp mortar. The aim is to analyze a complex phenomenon of coal response to blast-generated stresses from a series of discrete simulations of shock and gas actions in controllable processes. It is learned that despite the nucleation of primary crushing and fractures to originate from the point of impact energy in coal, a secondary crushing appears to depart from within the burden progressing towards the free boundaries. The extension of the secondary crushing zone appears to be influenced by the magnitude of the breaking stresses generated and the coal burden distance. A strong dependence of fines on the coal`s innate discontinuities (strength) and the energy input is highlighted.

  19. Temperatures in the blast furnace refractory lining

    SciTech Connect

    Hebel, R.; Streuber, C.; Steiger, R.; Jeschar, R.

    1995-12-01

    The campaign life duration of a blast furnace is mainly determined by the condition of the refractory lining in heavy-duty zones such as the hearth, bosh, belly and lower stack. To achieve a desired lifetime, the temperature of the lining in these areas thereby proved to be the decisive controllable parameter. Low operating temperatures result in prolonged service life and are attained through high cooling efficiency. Besides the refractory grade chosen, the wear profile is mainly determined by the type of cooling system applied and the cooling intensity. Therefore, an appropriate compromise between long service life and energy losses has to be found in each case. In order to predict the service life of a lining it is important to know the wear condition at all times during the campaign. The paper describes the approaches the authors have made so far on European blast furnaces, on a theoretical and practical basis, on how to analyze the lining wear.

  20. A Phased Array Approach to Rock Blasting

    SciTech Connect

    Leslie Gertsch; Jason Baird

    2006-07-01

    A series of laboratory-scale simultaneous two-hole shots was performed in a rock simulant (mortar) to record the shock wave interference patterns produced in the material. The purpose of the project as a whole was to evaluate the usefulness of phased array techniques of blast design, using new high-precision delay technology. Despite high-speed photography, however, we were unable to detect the passage of the shock waves through the samples to determine how well they matched the expected interaction geometry. The follow-up mine-scale tests were therefore not conducted. Nevertheless, pattern analysis of the vectors that would be formed by positive interference of the shockwaves from multiple charges in an ideal continuous, homogeneous, isotropic medium indicate the potential for powerful control of blast design, given precise characterization of the target rock mass.