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1

Experimental Measures of Blast and Acoustic Trauma in Marine Mammals.  

National Technical Information Service (NTIS)

Blast traumas are essentially mechanical responses, therefore blast effects are inducible and measurable in post-mortem specimens. To determine onset of damage zones for blast trauma in marine mammals, fresh post-mortem specimens were implanted with press...

D. R. Ketten

2004-01-01

2

Blast phenomena associated with high-speed impact  

Microsoft Academic Search

An experimental, analytical, and numerical investigation was conducted in order to measure air pressure at the target surface near the point of normal impact into semi-infinite rolled homogeneous armor (RHA) of a high-speed, 10mm diameter tungsten carbide sphere. Impact speeds varied from 0.9 to 3.8km\\/s. Numerical simulations of the impact were conducted in which the crater lip and ejecta motion

David J. Gee; William G. Reinecke; Scott J. Levinson

2007-01-01

3

Effects of scale on internal blast measurements  

NASA Astrophysics Data System (ADS)

This paper presents a comparative study between large and small-scale internal blast experiments with the goal of using the small-scale analog for energetic performance evaluation. In the small-scale experiment, highly confined 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 23 kg were unconfined and released in a chamber with a factor of 60,000 increase in volume. The comparative metric in these experiments is peak quasi-static overpressure, with the explosive sample expressed as sample energy/chamber volume, which normalizes measured pressures across scale. Small-scale measured pressures were always lower than the large-scale measurements, because of heat-loss to the high confinement inherent in the small-scale apparatus. This heat-loss can be quantified and used to correct the small-scale pressure measurements. In some cases the heat-loss was large enough to quench reaction of lower energy samples. These results suggest that small-scale internal blast tests do correlate with their large-scale counterparts, provided that heat-loss to confinement can be measured, and that less reactive or lower energy samples are not quenched by heat-loss.

Granholm, R.; Sandusky, H.; Lee, R.

2014-05-01

4

Scientific director`s report of atomic weapon tests at Eniwetok, 1951. Annex 1.6. Blast measurements, Part I. Summary report  

Microsoft Academic Search

Measurements of the blast pressures in Shots Dog, Easy, and George, together with earth-shock measurements on Shots Easy and George, gave new and important information concerning the magnitude and character of the blast wave near an atomic bomb. These experiments showed that secondary phenomena due presumably to thermal radiation and ion combination affect the pressure wave rather markedly near the

G. K. Hartmann; C. W. Lampson; C. J. Aronson

1951-01-01

5

Mabs monograph, air blast instrumentation, 1943-1993 measurement techniques and instrumentation. Volume 1. The nuclear era. 1945-1963. Technical report, 17 September 1992-31 May 1994  

Microsoft Academic Search

Blast wave measurement techniques and instrumentation developed by Military Applications of Blast Simulators (MABS) participating countries to study blast phenomena during the nuclear era are summarized. Passive and active gages both mechanical self-recording and electronic systems deployed on kiloton and megaton explosive tests during the period 1945-1963 are presented. The country and the year the gage was introduced are included

R. E. Reisler; J. H. Keefer; N. H. Ethridge

1995-01-01

6

Measurement of transmitted blast force-time histories  

SciTech Connect

A simple, reliable, and cost effective method is presented for the measurement of transmitted force behind a panel subjected to blast loads. Sensors were designed for a specific blast environment and successfully used to measure transmitted blast force behind solid polyethylene plates of thickness 0.125 and 0.25 inches. Experimental data was collected and examined to reveal consistent differences in the response of different thicknesses of otherwise identical panels. Finally, recommendations are made for future design, construction and use of similar sensors.

Dr. Benjamin Langhorst; Corey Cook; James Schondel; Dr. Henry S. Chu

2010-03-01

7

Rapid miniature fiber optic pressure sensors for blast wave measurements  

NASA Astrophysics Data System (ADS)

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.

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

2013-02-01

8

Pressure measurements in laboratory-scale blast wave flow fields.  

PubMed

The present study examines the effects that temporal and spatial averagings due to finite size and finite response time of pressure transducers have on the pressure measurements in blast wave flow fields generated by milligram charges of silver azide. In such applications, the characteristic time and length scales of the physical process are of the same order of magnitude as the temporal and spatial characteristics of the transducer. The measured pressure values will then be spatially and temporally averaged, and important parameters for the assessment of blast effects may not be properly represented in the measured trace. In this study, face-on and side-on pressure transducer setups are considered. In the experiments, face-on and side-on readings at the same distance from the charge as well as time-resolved optical visualization of the whole flow field are obtained simultaneously for the same explosive event. The procedure of data extraction from the experimental pressure traces is revisited and discussed in detail. In the numerical modeling part of the study, numerical blast flow fields are generated using an Euler flow solver. A numerical pressure transducer model is developed to qualitatively simulate the averaging effects. The experimental and numerical data show that the results of pressure measurements in experiments with small charges must be used with great caution. The effective averaging of the pressure signal may lead to a significant underestimation of blast wave intensities. The side-on setup is especially prone to this effect. The face-on setup provides results close to those obtained from optical records only if the pressure transducer is sufficiently remote from the charge. PMID:18163748

Rahman, S; Timofeev, E; Kleine, H

2007-12-01

9

Measurement of field blast testing data using high speed data acquisition system for steel fiber reinforced concrete  

Microsoft Academic Search

This paper reports on a measurement of field blast testing data for steel fiber reinforced concrete using high speed data acquisition system. In this experiment a field blast test was conducted by the Blast Research Unit of University Pertahanan Nasional Malaysia to investigate the behavior of steel fiber reinforced concrete panel subjected to air blast loading. The steel fiber reinforced

Mohammed Alias Yusof; Norazman Mohamad Nor; Ariffin Ismail; Risby Sohaimy; Nik Ghazali Nik Daud; Ng Choy Peng; Muhammad Fauzi Muhamad Zain

2011-01-01

10

Measurement of Phase Distribution Phenomena in a Triangular Conduit.  

National Technical Information Service (NTIS)

Two-phase (air/water) measurements of phase distribution phenomena were made in a triangular test section. These measurements included the lateral void fraction distribution and the velocity profile of the liquid phase. In addition, measurements of the de...

S. Sim R. T. Lahey

1983-01-01

11

Measuring Uncertainty and Conservatism in Simplified Blast Models.  

National Technical Information Service (NTIS)

This paper compares blast predictions (both reflected and incident loads, both for pressure and impulse, and both positive and negative phases) from a number of popular simplified models, including BlastX, ConWep, SHOCK, to a wide range of test data spann...

D. Bogosian J. Ferritto Y. Shi

2002-01-01

12

Effect of condensation phenomena on potentiometric measurements  

Microsoft Academic Search

Results of potentiometric analysis, namely those of pH measurements, depend on temperature control of the experimental setup, as it is expressed in the analytical law, the Nernst equation, starting from the primary level, where reference values are conventionally assigned to standard solutions, through the whole traceability chain, down to the service laboratory.Fundamental studies of pH standards, based on the measurement

M. J. Guiomar H. M. Lito; M. Filomena Camões; Catarina M. Viçoso

2006-01-01

13

Infrared Measurements of Multiphase Flow Phenomena  

NASA Astrophysics Data System (ADS)

Understanding of phase change heat transfer mechanisms remains elusive due its sensitivity to many variables, but also due to the lack of reliable local information that can enable models to be tested. Although point measurements of variables such as local film thickness and heat transfer have been made, techniques whereby these quantities can be measured over the large areas have been lacking. IR thermometry is an established technology that can be used where optical access to the surface is available in the wavelength of interest. The use of IR measurements is demonstrated in this work to measure the inner and outer wall temperatures of an electrically heated silicon tube during flow boiling of FC-72. The electrical conductivity of silicon can be varied over a broad range by controlling the dopant concentration. Since silicon is largely transparent to IR radiation, the temperature of the inner and outer walls can be measured by coating selected areas with IR opaque thin films. FC-72 is also partially transparent to IR radiation over a broad range of wavelengths, allowing the flow to be visualized. Details of the proposed technique, test apparatus, data reduction, and model development are presented.

Kim, Jungho; Kim, Tae Hoon; Kommer, Eric; Dessiatoun, Serguei

2011-11-01

14

Spatially-resolved X-ray scattering measurements of a planar blast wave  

NASA Astrophysics Data System (ADS)

We present X-ray scattering measurements characterizing the spatial temperature and ionization profile of a blast wave driven in a near-solid density foam. Several-keV X-rays scattered from a laser-driven blast wave in a carbon foam. We resolved the scattering in high resolution in space and wavelength to extract the plasma conditions along the propagation direction of the blast wave. We infer temperatures of 20-40 eV and ionizations of 2-4 in the shock and rarefaction regions of the blast wave. This range of measured ionization states allows for a detailed comparison between different models for the bound-free scattering. FLYCHK simulations of the temperature-ionization balance generally agree with the experimental values in the shocked region while consistently underestimating the ionization in the rarefaction.

Gamboa, E. J.; Keiter, P. A.; Drake, R. P.; Falk, K.; Montgomery, D. S.; Benage, J. F.

2014-06-01

15

An ultra-fast fiber optic pressure sensor for blast event measurements  

NASA Astrophysics Data System (ADS)

Soldiers who are exposed to explosions are at risk of suffering traumatic brain injury (TBI). Since the causal relationship between a blast and TBI is poorly understood, it is critical to have sensors that can accurately quantify the blast dynamics and resulting wave propagation through a helmet and skull that are imparted onto and inside the brain. To help quantify the cause of TBI, it is important to record transient pressure data during a blast event. However, very few sensors feature the capabilities of tracking the dynamic pressure transients due to the rapid change of the pressure during blast events, while not interfering with the physical material layers or wave propagation. In order to measure the pressure transients efficiently, a pressure sensor should have a high resonant frequency and a high spatial resolution. This paper describes an ultra-fast fiber optic pressure sensor based on the Fabry-Perot principle for the application of measuring the rapid pressure changes in a blast event. A shock tube experiment performed in US Army Natick Soldier Research, Development and Engineering Center has demonstrated that the resonant frequency of the sensor is 4.12 MHz, which is relatively close to the designed theoretical value of 4.113 MHz. Moreover, the experiment illustrated that the sensor has a rise time of 120 ns, which demonstrates that the sensor is capable of observing the dynamics of the pressure transient during a blast event.

Wu, Nan; Zou, Xiaotian; Tian, Ye; Fitek, John; Maffeo, Michael; Niezrecki, Christopher; Chen, Julie; Wang, Xingwei

2012-05-01

16

Measurements of Extreme Physical Phenomena by Fourier Fringe Analysis  

NASA Astrophysics Data System (ADS)

The paper reviews recent applications of the Fourier transform method (FTM) of fringe pattern analysis to the measurements of extreme physical phenomena, such as those involving ultra fast optical pulses, extremely small atomic displacements, and unconventional electron or EUV waves, and shows how the advantages of FTM are exploited in these cutting edge application areas.

Takeda, Mitsuo

2010-04-01

17

Operation GREENHOUSE. Scientific Director's Report of Atomic Weapon Tests at Eniwetok, 1951. Annex 4.2. Measurement of Surface-Air Movements Associated with Atomic Blasts.  

National Technical Information Service (NTIS)

The purpose of this project was to record continuous measurements of the surface winds in the vicinity of an atomic blast immediately prior to the blast, during passage of the shock wave, and immediately after the blast with special regard to the blast-in...

R. M. Rados J. C. Bogert T. O. Haig

1985-01-01

18

On-line ultrasonic system for measuring thickness of the copper stave in the blast furnace  

NASA Astrophysics Data System (ADS)

The blast furnace is used make molten iron from sintered ore and the cokes in the steel industry. Recently, the copper stave cooling system placed on inner face of the blast furnace body to protect the steel shell from heat. In the high temperature environment, the wear between the stave and the material makes the cooling stave thinning by the downward movement of the materials in the blast furnace. It was impossible to access the copper stave with the ultrasonic sensor for measuring thickness because the copper stave is covered with the steel shell and there is backing refractory between the stave and the steel shell. The unique ultrasonic sensor which can approach the cooling stave through the cooling line was developed to measure thickness. The thickness can be measured with portable ultrasonic thickness sensor and can be monitored continuously with embedded sensors.

Choi, Sang-Woo; Kim, Dohoon

2012-05-01

19

Laser Doppler Measurements of Globular Concentrations and Flow Perturbations in a Model Gas Blast Interrupter.  

National Technical Information Service (NTIS)

A laser-Doppler method for measuring plasma flow velocities in a 10 kA free burning arc has already been described. The present contribution describes the use of the laser Doppler technique for measurements in a model gas blast interrupter. The interrupte...

P. S. Todorovic G. R. Jones

1983-01-01

20

High spatial resolution measurements of ram accelerator gas dynamic phenomena  

NASA Astrophysics Data System (ADS)

High spatial resolution experimental tube wall pressure measurements of ram accelerator gas dynamic phenomena are presented. The projectile resembles the centerbody of a ramjet and travels supersonically through a tube filled with a combustible gaseous mixture, with the tube acting as the outer cowling. Pressure data are recorded as the projectile passes by sensors mounted in the tube wall at various locations along the tube. Data obtained by using a special highly instrumented section of tube has allowed the recording of gas dynamic phenomena with a spatial resolution on the order of one tenth the projectile length. High spatial resolution tube wall pressure data from the three regimes of propulsion studied to date (subdetonative, transdetonative, and superdetonative) are presented and reveal the 3D character of the flowfield induced by projectile fins and the canting of the projectile body relative to the tube wall. Also presented for comparison to the experimental data are calculations made with an inviscid, 3D CFD code.

Hinkey, J. B.; Burnham, E. A.; Bruckner, A. P.

1992-07-01

21

DEVELOPMENT OF MECHANICAL PRESSURE-TIME AND PEAK PRESSURE RECORDERS FOR ATOMIC BLAST MEASUREMENT  

Microsoft Academic Search

Two mechanical air blast gages are described. The successful ; modification, field use, and evaluation of an indenter gage for the measurement ; of peak pressure is described. This gage is fully damped and has a response time ; of from 3 to 5 msec in the pressure range from 1 to 250 psi. Under appropriate ; shock conditions reliable

F. J. Oliver; R. R. Caforek; H. R. Smith; W. E. Morris

1955-01-01

22

Blast Wave Measurements from Detonating Spherical 8.4 Kg Comp B Charges.  

National Technical Information Service (NTIS)

Air blast wave measurements were made at distances 4 to 17 m from detonating 8.4 kg spherical Comp B charges suspended at 0.75 and 1.0 m over a plain ground surface. Pressure-time histories, peak pressures, durations and impulses are presented. A comparis...

I. Aaseborn

1983-01-01

23

Low-cost rapid miniature optical pressure sensors for blast wave measurements.  

PubMed

This paper presents an optical pressure sensor based on a Fabry-Perot (FP) interferometer formed by a 45° angle polished single mode fiber and an external silicon nitride diaphragm. The sensor is comprised of two V-shape grooves with different widths on a silicon chip, a silicon nitride diaphragm released on the surface of the wider V-groove, and a 45° angle polished single mode fiber. The sensor is especially suitable for blast wave measurements: its compact structure ensures a high spatial resolution; its thin diaphragm based design and the optical demodulation scheme allow a fast response to the rapid changing signals experienced during blast events. The sensor shows linearity with the correlation coefficient of 0.9999 as well as a hysteresis of less than 0.3%. The shock tube test demonstrated that the sensor has a rise time of less than 2 µs from 0 kPa to 140 kPa. PMID:21643336

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

2011-05-23

24

NASA CONNECT: Data Analysis and Measurement - Having a Solar Blast  

NSDL National Science Digital Library

In this program, students learn how NASA researchers study the Sun-Earth connection. Students learn about satellites that monitor the Sun: (Solar & Heliospheric Observatory) SOHO, Advanced Composition Explorer (ACE), and Imager for Magnetopause-to-Aurora Global Exploration (IMAGE) and (Highg Energy Solar Spectrostopic Imager) HESSI. They observe NASA researchers using data analysis and measurement to determine the solar cycle of the Sun. By conducting hands-on and web activities, students make connections between NASA research and the mathematics, science, and technology they learn in their classrooms. The program consists of two parts: a 30-minute video and an on-line educators guide.

2002-01-01

25

Precise Measurement of Deuteron Tensor Analyzing Powers with BLAST  

SciTech Connect

We report a precision measurement of the deuteron tensor analyzing powers T{sub 20} and T{sub 21} at the MIT-Bates Linear Accelerator Center. Data were collected simultaneously over a momentum transfer range Q=2.15-4.50 fm{sup -1} with the Bates Large Acceptance Spectrometer Toroid using a highly polarized deuterium internal gas target. The data are in excellent agreement with calculations in a framework of effective field theory. The deuteron charge monopole and quadrupole form factors G{sub C} and G{sub Q} were separated with improved precision, and the location of the first node of G{sub C} was confirmed at Q=4.19{+-}0.05 fm{sup -1}. The new data provide a strong constraint on theoretical models in a momentum transfer range covering the minimum of T{sub 20} and the first node of G{sub C}.

Zhang, C.; Akdogan, T.; Bertozzi, W.; Botto, T.; Clasie, B.; DeGrush, A.; Dow, K.; Farkhondeh, M.; Franklin, W.; Gilad, S.; Hasell, D.; Kolster, H.; Maschinot, A.; Matthews, J.; Meitanis, N.; Milner, R.; Redwine, R.; Seely, J.; Shinozaki, A.; Tschalaer, C. [Laboratory for Nuclear Science and Bates Linear Accelerator Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

2011-12-16

26

Evaluation of the performance of the blast analysis and measurement system  

NASA Astrophysics Data System (ADS)

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.

Luz, George A.

2001-05-01

27

Measuring thickness of the copper stave in blast furnace using ultrasonic technique in cooling line  

Microsoft Academic Search

The blast furnace is used to smelt iron in the steel industry. Ore and cokes are input and hot air is blown into the chamber of the blast furnace. In the high temperature environment, the wear between the stave and the materials makes the cooling stave thinning by the downward movement of the materials in the blast furnace. The thickness

Sang-Woo Choi; Jung-Luel Yoo; Tae-Hwa Choi; Kwan-Tae Kim

2010-01-01

28

Spatially-resolved x-ray scattering measurements of a planar blast wave  

NASA Astrophysics Data System (ADS)

In many laboratory astrophysics experiments, intense laser irradiation creates novel material conditions with large, one-dimensional gradients in the temperature, density, and ionization state. X-ray Thomson scattering is a powerful technique for measuring these plasma parameters. However, the scattered signal is typically measured with little or no spatial resolution, which limits the ability to diagnose inhomogeneous plasmas. We report on the development of a new imaging x-ray Thomson spectrometer (IXTS) for the Omega laser facility. The diffraction of x-rays from a toroidally curved crystal creates high-resolution images that are spatially resolved along a one-dimensional profile while spectrally dispersing the radiation. An experiment is described in which we used the IXTS to measure the spatial temperature profile of a novel system. A low-density carbon foam was irradiated with intensities on the order of 10^15 W/cm^2, launching a planar blast wave. After a delay of several nanoseconds, x-rays created from irradiation of a nickel foil, scattered at 90 and were recorded by the IXTS. The resulting spatially resolved scattering spectra were analyzed to extract the temperature profile across the blast wave.

Gamboa, E. J.; Montgomery, D. S.; Benage, J. F.; Falk, K.; Kuranz, C. C.; Keiter, P. A.; Drake, R. P.

2012-10-01

29

An Undergraduate Experiment for the Measurement of the Speed of Sound in Air: Phenomena and Discussion  

ERIC Educational Resources Information Center

In this paper, we present and discuss some phenomena in an undergraduate experiment for the measurement of the speed of sound in air. A square wave distorts when connected to a piezoelectric transducer. Moreover, the amplitude of the receiving signal varies with the driving frequency. Comparing with the Gibbs phenomenon, these phenomena can be…

Yang, Hujiang; Zhao, Xiaohong; Wang, Xin; Xiao, Jinghua

2012-01-01

30

Blast furnace burden detector  

Microsoft Academic Search

A system for measuring the difference between coke and pellet layers in a blast furnace is described. The measurement is based on a high frequency magnetic proximity principle where coke, a conductor, causes a change in apparent coil resistance. Theoretical and experimental results are presented. The application of the system to No.5 Blast Furnace at Inland Steel (USA) is also

H. Gerber; P. Chaubal

1999-01-01

31

Comparison of building loads analysis and system thermodynamics (BLAST) computer program simulations and measured energy use for Army buildings. Interim report  

Microsoft Academic Search

This report describes an analysis of actual measured energy consumption vs energy consumption simulated by the Building Loads Analysis and System Thermodynamics (BLAST) computer program. A dental clinic and a battalion headquarters and classroom building were modeled; comparisons of the BLAST output using onsite weather and measured energy consumption data are made for the two buildings. The report includes tables

D. Herron; L. M. Windingland; D. C. Hittle

1980-01-01

32

Ionospheric Signature of Surface Mine Blasts from Global Positioning System Measurements  

NASA Technical Reports Server (NTRS)

Sources such as atmospheric or buried explosions and shallow earthquakes are known to produce infrasonic pressure waves in the atmosphere. Because of the coupling between neutral particles and electrons at ionospheric altitudes, these acoustic and gravity waves induce variations of the ionospheric electron density. The Global Positioning System (GPS) provides a way of directly measuring the total electron content in the ionosphere and, therefore, of detecting such perturbations in the upper atmosphere. In July and August 1996, three large surface mine blasts (1.5 Kt each) were detonated at the Black Thunder coal mine in eastern Wyoming. As part of a seismic and acoustic monitoring- experiment, we deployed five dual-frequency GPS receivers at distances ranging from 50 to 200 km from the mine and were able to detect the ionospheric perturbation caused by the blasts. The perturbation starts 10 to 15 min after the blast, lasts for about 30 min, and propagates with an apparent horizontal velocity of 1200 meters per second. Its amplitude reaches 3 x 10 (exp 14) el per square meters in the 7-3 min period band, a value close to the ionospheric perturbation caused by the M = 6.7 Northridge earthquake. The small signal-to-noise ratio of the perturbation can be improved by slant-stacking the electron content time-series recorded by the different GPS receivers taking into account the horizontal propagation of the perturbation. The energy of the perturbation is concentrated in the 200 to 300 second period band, a result consistent with previous observations and numerical model predictions. The 300 second band probably corresponds to gravity modes and shorter periods to acoustic modes, respectively. Using a 1-D stratified velocity model of the atmosphere we show that linear acoustic ray tracing fits arrival times at all GPS receivers. We interpret the perturbation as a direct acoustic wave caused by the explosion itself. This study shows that even relatively small subsurface events can produce ionospheric perturbations that are above the detection threshold of the GPS technique. By sensing derivative signals, which can be detected over a relatively broad region, it appears that GPS might be particularly useful for source characterization within the first acoustic quiet zone where infrasound would probably be ineffective. This suggests that dual-frequency GPS monitoring could contribute to Comprehensive Nuclear Test Ban Treaty verification.

Calais, Eric; Minster, J. Bernard; Hofton, Michelle A.; Hedlin, Michael A. H.

1998-01-01

33

Testing of an inertial-reference system concept to measure blast-induced displacements of vehicles. Final contract report, 23 March23 July 1987  

Microsoft Academic Search

This work is the first phase of a project to develop an inertial-reference system to measure the displacement of military vehicles exposed to a blast wave in large shock tubes or high-explosive simulations of nuclear weapons. Experimental data describing the movement of military vehicles by blast is required for survivability assessments of such vehicles and for validation of computer models

N. H. Ethridge; L. A. Dixon; W. F. Jackson

1987-01-01

34

Measuring the velocities of particles in a shot-blasting chamber  

NASA Astrophysics Data System (ADS)

This paper presents a method for measuring the velocity of a flow of particles accelerated on a shot-blasting wheel and then expanding into space at a wide angle of approximately 45°. The method uses the pulsed nature of the flow characteristic for turbo machinery with a finite number of wheel blades and calculates the velocity from the time shift between the particles hitting two targets at a known distance. This method does not depend on the material properties of the particles; however, a large number of particles is required for a successful measurement. The impacts are detected with a microphone covered by a steel membrane, making the exposed parts cheap and easily replaceable. This makes the method suitable for industrial test-and-development purposes, including the efficiencies of acceleration measurements. A cross-correlation of the signals was used, but the characteristic cycle (one rotation of the wheel) had to be determined beforehand by overlapping and averaging several cycles in order to compensate for the fact that different particles would be hitting the targets.

Bombek, G.; Hribernik, A.

2010-08-01

35

STUDY ON MEASUREMENT OF BLAST-INDUCED SEISM AND BUILDING SAFETY CRITERIA  

Microsoft Academic Search

The rationality of using particle vibration velocity to describe blast-induced seismic effect is testified by using the stress-strain relation of rock and soil,and characteristics of wave propagation. A lot of seismic wave diagrams and frequency spectrograms are obtained from a lot of blast-induced seism. The propagation law and parameters of seismic wave in different places are studied. The regulations of

Yan Zhixin; Wang Yonghe; Jiang Ping; Wang Houyu

36

Pressure-sensitive paint measurements of transient shock phenomena.  

PubMed

Measurements of the global pressure field created by shock wave diffraction have been captured optically using a porous pressure-sensitive paint. The pressure field created by a diffracting shock wave shows large increases and decreases in pressure and can be reasonably accurately captured using CFD. The substrate, a thin-layer chromatography (TLC) plate, has been dipped in a luminophore solution. TLC plates are readily available and easy to prepare. Illumination comes from two high-intensity broadband Xenon arc light sources with short-pass filters. The sample is imaged at 100 kHz using a Vision Research Phantom V710 in conjunction with a pair of long and short pass filters, creating a band. The PSP results are compared with numerical simulations of the flow using the commercial CFD package Fluent as part of ANSYS 13 for two Mach numbers. PMID:23549365

Quinn, Mark Kenneth; Kontis, Konstantinos

2013-01-01

37

Stalfiberarmerade Betongplattor Utsatta foer Detonationslaster i Stoetvagstub. Maetresultat (Steel Fibre Reinforced Concrete Slabs Subjected to Blast Loading in a Shock Tube. Measurements Results).  

National Technical Information Service (NTIS)

In the report, measurement results are presented from blast loadings performed at the test and research station at Maersta in 1996. Experiments were performed on 12 slabs of steel fiber and conventionally reinforced concrete slabs subjected to various lev...

L. Agardh

1997-01-01

38

Measuring Intracranial Pressure and Correlation with Severity of Blast Traumatic Brain Injury.  

National Technical Information Service (NTIS)

A greater understanding of the mechanism(s) of TBI due from overpressure exposure is critical to develop effective protection and treatments. Fundamental, yet unresolved, questions concern the mode of blast energy transfer to the brain as well as the cons...

P. J. VandeVord

2013-01-01

39

Measuring Intracranial Pressure and Correlation with Severity of Blast Traumatic Brain Injury.  

National Technical Information Service (NTIS)

A greater understanding of the mechanism(s) of TBI due from overpressure exposure is critical to develop effective protection and treatments. Fundamental, yet unresolved, questions concern the mode of blast energy transfer to the brain as well as the cons...

P. VandeVord

2011-01-01

40

Contamination of current-clamp measurement of neuron capacitance by voltage-dependent phenomena  

PubMed Central

Measuring neuron capacitance is important for morphological description, conductance characterization, and neuron modeling. One method to estimate capacitance is to inject current pulses into a neuron and fit the resulting changes in membrane potential with multiple exponentials; if the neuron is purely passive, the amplitude and time constant of the slowest exponential give neuron capacitance (Major G, Evans JD, Jack JJ. Biophys J 65: 423–449, 1993). Golowasch et al. (Golowasch J, Thomas G, Taylor AL, Patel A, Pineda A, Khalil C, Nadim F. J Neurophysiol 102: 2161–2175, 2009) have shown that this is the best method for measuring the capacitance of nonisopotential (i.e., most) neurons. However, prior work has not tested for, or examined how much error would be introduced by, slow voltage-dependent phenomena possibly present at the membrane potentials typically used in such work. We investigated this issue in lobster (Panulirus interruptus) stomatogastric neurons by performing current clamp-based capacitance measurements at multiple membrane potentials. A slow, voltage-dependent phenomenon consistent with residual voltage-dependent conductances was present at all tested membrane potentials (?95 to ?35 mV). This phenomenon was the slowest component of the neuron's voltage response, and failure to recognize and exclude it would lead to capacitance overestimates of several hundredfold. Most methods of estimating capacitance depend on the absence of voltage-dependent phenomena. Our demonstration that such phenomena make nonnegligible contributions to neuron responses even at well-hyperpolarized membrane potentials highlights the critical importance of checking for such phenomena in all work measuring neuron capacitance. We show here how to identify such phenomena and minimize their contaminating influence.

White, William E.

2013-01-01

41

Operation Greenhouse. Scientific Director's report of atomic-weapon tests at Eniwetok, 1951. Annex 4. 2. Measurement of surface-air movements associated with atomic blasts  

SciTech Connect

The purpose of this project was to record continuous measurements of the surface winds in the vicinity of an atomic blast immediately prior to the blast, during passage of the shock wave, and immediately after the blast with special regard to the blast-induced afterwind following local dissipation of the shock wave. From the data obtained, it was concluded that following an atomic explosion there are two specific causes of air-mass movement. One is related to the shock phenomenon and the other to the rising fireball. It can also be concluded that the heated-thermopile-type and strain-gage-type anemometers could be developed to yield more complete data on the air-mass movement at ground level following an atomic explosion.

Rados, R.M.; Bogert, J.C.; Haig, T.O.

1985-09-01

42

Accelerating cine phase-contrast flow measurements usingk-t BLAST andk-t SENSE  

Microsoft Academic Search

Conventional phase-contrast velocity mapping in the ascending aorta was combined with k-t BLAST and k-t SENSE. Up to 5.3-fold net acceleration was achieved, enabling single breath- hold acquisitions. A standard phase-contrast (PC) sequence with interleaved acquisition of the velocity-encoded segments was modified to collect data in 2 stages, a high-resolution undersampled and a low-resolution fully sampled training stage. In addition,

Christof Baltes; Sebastian Kozerke; Michael S. Hansen; Klaas P. Pruessmann; Jeffrey Tsao; Peter Boesiger

2005-01-01

43

Ultrafast Fabry-Perot fiber-optic pressure sensors for multimedia blast event measurements.  

PubMed

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

Zou, Xiaotian; Wu, Nan; Tian, Ye; Zhang, Yang; Fitek, John; Maffeo, Michael; Niezrecki, Christopher; Chen, Julie; Wang, Xingwei

2013-02-20

44

MATHEMATICAL MODELLING OF FLOWS AND TEMPERATURE DISTRIBUTIONS IN THE BLAST FURNACE HEARTH  

Microsoft Academic Search

The erosion of hearth refractories typically governs the asset life of a blast furnace. Since operating conditions within the hearth make it practically impossible for direct measurement and visualisation, physical and mathematical models play an important role in understanding and assessing the cause-effect phenomena between the liquid iron, coke bed and refractories. A numerical model has been developed to predict

D. MALDONADO; P. ZULLI; B. Y. GUO

45

Flight test measurements and analysis of sonic boom phenomena near the shock wave extremity  

NASA Technical Reports Server (NTRS)

A NASA flight test program conducted during the summer and fall of 1970 was devoted to investigating sonic boom phenomena near caustics formed by steady flight near the threshold Mach number, during accelerations, and at the lateral extremes of the ground carpet. The vertical extent of the shock waves attached to near-sonic airplanes was also studied. The flights were conducted over the 1500 ft instrumented BREN tower so that vertical surveys through the shock waves were measured. These data on caustic phenomena near the shock wave extremity were analyzed in detail and compared with theoretical results. Amplifications of shock wave strength varied from 2 to 5 during longitudinal accelerations, from 1 to 1.8 during steady threshold Mach number flight, and up to 3 for small inadvertent accelerations during flight near the threshold Mach number.

Haglund, G. T.; Kane, E. J.

1974-01-01

46

The Evolution of Structural Order as a Measure of Thermal History of Coke in the Blast Furnace  

NASA Astrophysics Data System (ADS)

Investigations were carried out on cokes heat treated in the laboratory and on cokes extracted from the experimental blast furnace (EBF) raceway and hearth. X-ray diffraction (XRD) measurements were performed to investigate changes in structural order ( L c), chemical transformations in coke ash along with comparative thermodynamic equilibrium studies and the influence of melt. Three data processing approaches were used to compute L c values as a function of temperature and time and linear correlations were established between L c and heat treatment temperatures during laboratory investigations. These were used to estimate temperatures experienced by coke in various regions of EBF and estimated raceway temperatures were seen to follow the profile of combustion peak. The MgAl2O4 spinel was observed in coke submerged in slag during laboratory studies and in cokes found further into the raceway. Coke in contact with hot metal showed XRD peaks corresponding to presence of Fe3Si. The intensity of SiO2 peak in coke ash was seen to decrease with increasing temperature and disappeared at around 1770 K (1500 °C) due to the formation of SiC. This study has shown that the evolution of structural order and chemical transformations in coke could be used to estimate its thermal history in blast furnaces.

Lundgren, Maria; Khanna, Rita; Ökvist, Lena Sundqvist; Sahajwalla, Veena; Björkman, Bo

2014-04-01

47

Design Considerations for Remote High-Speed Pressure Measurements of Dynamic Combustion Phenomena  

SciTech Connect

As gas turbine combustion systems evolve to achieve ultra-low emission targets, monitoring and controlling dynamic combustion processes becomes increasingly important. These dynamic processes may include flame extinction, combustion-driven instabilities, or other dynamic combustion phenomena. Pressure sensors can be incorporated into the combustor liner design, but this approach is complicated by the harsh operating environment. One practical solution involves locating the sensor in a more remote location, such as outside the pressure casing. The sensor can be connected to the measurement point by small diameter tubing. Although this is a practical approach, the dynamics of the tubing can introduce significant errors into the pressure measurement. This paper addresses measurement errors associated with semi-infinite coil remote sensing setups and proposes an approach to improve the accuracy of these types of measurements.

Straub, D.L.; Ferguson, D.H.; Rohrssen, Robert (West Virginia University, Morgantown, WV); Perez, Eduardo (West Virginia University, Morgantown, WV)

2007-01-01

48

Precise Measurements of the Density and Critical Phenomena Near Phase Transitions in Liquid Helium  

NASA Technical Reports Server (NTRS)

The first-year progress for the project of precise measurements of the density and critical phenomena of helium near phase transitions is summarized below: (1) completion of a cryogenic sample probe for the proposed measurements, and the rehabilitation of a designated laboratory at Caltech for this project; (2) construction and testing of a superconducting niobium cavity; (3) acquisition of one phase-locked-loop system for high-resolution frequency control and read- out; (4) setting up high-resolution thermometry (HRT) for temperature readout and control; (5) developing new approaches for calibrating the coefficient between the resonant frequency shift (delta f) and the helium density (rho), as well as for measuring the effect of gravity on T(sub lambda) to a much better precision; (6) programming of the interface control of all instruments for automatic data acquisition; and (7) improving data analyses and fitting procedures.

Yeh, Nai-Chang

1997-01-01

49

Maetning av Luftstoetvagens Tryck-Tidfoerlopp fran Detonerande 48 kg Sfaeriska Hexotol-Trotylladdingar (Blast Wave Measurements from Detonating Spherical 48 kg Comp B/TNT Charges),  

National Technical Information Service (NTIS)

Air blast wave measurements 1.1 m above ground have been made at distances 5.5 - 25 m from detonating 48 kg spherical Comp B/TNT charges suspended at 1.05 - 1.32 m over a plain ground surface. Pressure-time histories, peak pressures, durations and impulse...

K. Edin I. Aseborn

1988-01-01

50

Impact of T-ACASI on Survey Measurements of Subjective Phenomena  

PubMed Central

Numerous studies have shown that audio-computer-assisted self-interviewing (audio-CASI) and telephone audio-CASI (T-ACASI) technologies yield increased reporting of sensitive and stigmatized objective phenomena such as sexual and drug use behaviors. Little attention has been given, however, to the impact of these technologies on the measurement of subjective phenomena (attitudes, opinions, feelings, etc.). This article reports results for the seven subjective measurements included in the National STD and Behavior Measurement Experiment (NSBME). NSBME drew probability samples of USA and Baltimore adults (Ns = 1,543 and 744, respectively) and randomized these respondents to be interviewed by T-ACASI or telephone interviewer-administered questioning (T-IAQ). Response distributions for all subjective measurements obtained by T-ACASI diverge from those obtained by human telephone interviewers. For six of our seven ordinal-scaled measurements, this divergence involved shifting responses directionally along the ordinal scale, as opposed to a nondirectional redistribution among response categories. When interviewed by T-ACASI, respondents were more supportive of traditional gender roles and corporal punishment, less supportive of integrated neighborhoods and same-gender sex, and more likely to agree that occasional marijuana use is harmless and to describe themselves as attractive. The majority of these results suggest that telephone survey respondents may provide more “tolerant” and “socially liberal” responses to human interviewers than to a T-ACASI computer. Similarly, although the evidence is not entirely consistent, the impact of T-ACASI appears to increase with the social vulnerability of the population surveyed.

Harmon, Thomas; Turner, Charles F.; Rogers, Susan M.; Eggleston, Elizabeth; Roman, Anthony M.; Villarroel, Maria A.; Chromy, James R.; Ganapathi, Laxminarayana; Li, Sheping

2009-01-01

51

Modelling of transient state phenomena of composite superconducting conductors during pulse Ic(B) measurements  

NASA Astrophysics Data System (ADS)

Computational modelling of pulsed current characterisation in composite superconducting conductors has been performed as the first step towards understanding the electromagnetic processes occurring during pulse Ic(B) measurements in the Cryo-BI-Pulse System. A simplified 2D model was created using the Finite Element Method (FEM) software ANSYS to investigate the current transfer process in a multifilamentary conductor, resulting in time dependent 2D distributions of electrical potential and current density along the wire axis. Experimental measurements were performed for two dissimilar NbTi wires and MgB2 tape: excellent agreement between pulse and DC results were found for one NbTi wire and the MgB2 tape, but the critical current for the other NbTi wire (Luvata OK3900) was significantly lower in pulsed current than DC characterisation. This behaviour has been interpreted in relation to current transfer phenomena using results from the FEM modelling.

Krosny, S.; Wo?niak, M.; Hopkins, S. C.; St?pie?, M. A.; Grzesik, B.; Glowacki, B. A.

2010-06-01

52

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

Microsoft Academic Search

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

George B Ulrich; Hu Foster Longmire

2010-01-01

53

Density-of-states effective mass and scattering parameter measurements by transport phenomena in thin films  

NASA Astrophysics Data System (ADS)

A novel machine has been developed to measure transport coefficients in the temperature range of 50-350 K of thin films deposited on electrically insulating substrates. The measured coefficients-resistivity, Hall, Seebeck, and Nernst-are applied to solutions of the Boltzmann transport equation to give information about the film's density-of-states effective mass, the Fermi energy level, and an energy-dependent scattering parameter. The machine is designed to eliminate or compensate for simultaneously occurring transport phenomena that would interfere with the desired measured quantity, while allowing for all four coefficients to be measured on the same sample. An average density-of-states effective mass value of 0.29+/-0.04me was measured on the transparent conductive oxide, cadmium stannate (CTO), over a carrier concentration range of 2-7×1020 cm-3. This effective mass value matched previous results obtained by optical and thermoelectric modeling. The measured scattering parameter indicates that neutral impurities or a mixture of scattering mechanisms may inhibit the transport of carriers in CTO.

Young, D. L.; Coutts, T. J.; Kaydanov, V. I.

2000-02-01

54

Blast injury.  

PubMed

The shock wave generated by an explosion ("blast wave") may cause injury in any or all of the following: (1) direct impact on the tissues of variations in environmental pressure; (2) flying glass and other debris set in motion by it; (3) propulsion of the body. Injuries in the first category affect gas-containing organs (ears, lungs and intestines), and acute death is attributed to air forced into the coronary vessels via damaged pulmonary alveoli. It is estimated that overpressure sufficient to cause lung injury may occur up to five miles from a 20-megaton nuclear explosion. The greatest single hazard from blast is, however, flying glass, and serious wounding from this cause is possible up to 12 miles from an explosion of this magnitude. PMID:6015742

de Candole, C A

1967-01-28

55

Determination of constant-volume balloon capabilities for aeronautical research. [specifically measurement of atmospheric phenomena  

NASA Technical Reports Server (NTRS)

The proper application of constant-volume balloons (CVB) for measurement of atmospheric phenomena was determined. And with the proper interpretation of the resulting data. A literature survey covering 176 references is included. the governing equations describing the three-dimensional motion of a CVB immersed in a flow field are developed. The flowfield model is periodic, three-dimensional, and nonhomogeneous, with mean translational motion. The balloon motion and flow field equations are cast into dimensionless form for greater generality, and certain significant dimensionless groups are identified. An alternate treatment of the balloon motion, based on first-order perturbation analysis, is also presented. A description of the digital computer program, BALLOON, used for numerically integrating the governing equations is provided.

Tatom, F. B.; King, R. L.

1977-01-01

56

Seismic vibrations in bulk blasting with high-precise electronic and nonelectric blasting systems at quarries  

Microsoft Academic Search

The authors report measurement data on seismic waves in bulk blasting at quarries by using new high-precise electronic and\\u000a pyrotechnic blasting systems. It is proved that both systems are efficient, intensity of seismic waves is much lower in large-scale\\u000a bulk blasting. The authors implemented numerical modeling of seismic wave propagation under a short-delay bulk blast at a\\u000a quarry. Influence of

E. N. Sher; A. G. Chernikov

2009-01-01

57

The study of some peculiar phenomena in ultra-soft x-ray measurements using synthetic multilayer crystals  

SciTech Connect

Several interesting phenomena involving ultra-soft X-rays and synthetic multilayer crystals were studied as a result of the on-going process of improving the Rigaku Model 3630 Wafer Analyzer for the measurement of BPSG (1000-2500 {Angstrom}) and other thin films. These phenomena can be divided into four categories; {open_quotes}ghost{close_quotes} peaks, diffraction from the substrate, fluorescence from the multilayer and higher order lines from the multilayer. Each of these is a potential source of error in the measurement of ultra-soft X-rays. Fortunately, as will be shown, each can be readily dealt with. 3 refs., 7 figs.

Kobayashi, H.; Toda, K.; Kohno, H.; Arai, T. [Rigaku Industrial Corp., Osaka (Japan); Wilson, R. [Rigaku/USA, Inc., Danvers, MA (United States)

1995-12-31

58

PIV Experiments to Measure Flow Phenomena in a Scaled Model of a VHTR Lower Plenum  

SciTech Connect

A report of experimental data collected at the Matched-Index-of-Refraction (MIR) Laboratory in support of contract DE-AC07-05ID14517 and the INL Standard Problem on measurements of flow phenomena occurring in a lower plenum of a typical prismatic VHTR concept reactor to assess CFD code is presented. Background on the experimental setup and procedures is provided along with several samples of data obtained from the 3-D PIV system and an assessment of experimental uncertainty is provided. Data collected in this study include 3-dimensional velocity-field descriptions of the flow in all four inlet jets and the entire lower plenum with inlet jet Reynolds numbers (ReJet) of approximately 4300 and 12,400. These investigations have generated over 2 terabytes of data that has been processed to describe the various velocity components in formats suitable for external release and archived on removable hard disks. The processed data from both experimental studies are available in multi-column text format.

Hugh M. McIlroy, Jr.; Donald M. McEligot; Richard R. Schultz; Daniel Christensen; Robert J. Pink; Ryan C. Johnson

2006-09-01

59

Cost Effective Strengthening Measures to Increase the Blast Resistance of Structures Adjacent to Explosive Facilities.  

National Technical Information Service (NTIS)

The paper includes the description of the recent R & D efforts (1991 - 1994) in researching, developing, testing and building practical strengthening measures for existing civilian buildings to increase their resistance against explosive effects. The stre...

R. Eytan

1994-01-01

60

Analysis of the dynamic phenomena during lamination of multilayer printed circuit board by the measurement of pressure distribution  

Microsoft Academic Search

In order to develop improved methods for manufacturing multilayer printed circuit boards (MLPCBs), it is necessary to understand the dynamic phenomena that occur during the lamination process. For this purpose, the authors have performed direct measurement of the pressure distribution in MLPCB laminates during curing by the application of their own force sensor technique and have concluded that the dynamic

Y. Hatamura; K. Yamauchi

1990-01-01

61

RESEARCH PAPERS : Ionospheric signature of surface mine blasts from Global Positioning System measurements  

Microsoft Academic Search

Sources such as atmospheric or buried explosions and shallow earthquakes are known to produce infrasonic pressure waves in the atmosphere Because of the coupling between neutral particles and electrons at ionospheric altitudes, these acoustic and gravity waves induce variations of the ionospheric electron density. The Global Positioning System (GPS) provides a way of directly measuring the total electron content in

Eric Calais; J. Bernard Minster; Michelle Hofton; Michael Hedlin

1998-01-01

62

Beat phenomena in metal nanowires, and their implications for resonance-based elastic property measurements  

NASA Astrophysics Data System (ADS)

The elastic properties of 1D nanostructures such as nanowires are often measured experimentally through actuation of nanowires at their resonance frequency, and then relating the resonance frequency to the elastic stiffness using the elementary beam theory. In the present work, we utilize large scale molecular dynamics simulations to report a novel beat phenomenon in [110] oriented Ag nanowires. The beat phenomenon is found to arise from the asymmetry of the lattice spacing in the orthogonal elementary directions of [110] nanowires, i.e. the [1&cmb.macr;10] and [001] directions, which results in two different principal moments of inertia. Because of this, actuations imposed along any other direction are found to decompose into two orthogonal vibrational components based on the actuation angle relative to these two elementary directions, with this phenomenon being generalizable to <110> FCC nanowires of different materials (Cu, Au, Ni, Pd and Pt). The beat phenomenon is explained using a discrete moment of inertia model based on the hard sphere assumption; the model is utilized to show that surface effects enhance the beat phenomenon, while effects are reduced with increasing nanowire cross-sectional size or aspect ratio. Most importantly, due to the existence of the beat phenomena, we demonstrate that in resonance experiments only a single frequency component is expected to be observed, particularly when the damping ratio is relatively large or very small. Furthermore, for a large range of actuation angles, the lower frequency is more likely to be detected than the higher one, which implies that experimental predictions of the Young's modulus obtained from resonance may in fact be under-predictions. The present study therefore has significant implications for experimental interpretations of the Young's modulus as obtained via resonance testing.The elastic properties of 1D nanostructures such as nanowires are often measured experimentally through actuation of nanowires at their resonance frequency, and then relating the resonance frequency to the elastic stiffness using the elementary beam theory. In the present work, we utilize large scale molecular dynamics simulations to report a novel beat phenomenon in [110] oriented Ag nanowires. The beat phenomenon is found to arise from the asymmetry of the lattice spacing in the orthogonal elementary directions of [110] nanowires, i.e. the [1&cmb.macr;10] and [001] directions, which results in two different principal moments of inertia. Because of this, actuations imposed along any other direction are found to decompose into two orthogonal vibrational components based on the actuation angle relative to these two elementary directions, with this phenomenon being generalizable to <110> FCC nanowires of different materials (Cu, Au, Ni, Pd and Pt). The beat phenomenon is explained using a discrete moment of inertia model based on the hard sphere assumption; the model is utilized to show that surface effects enhance the beat phenomenon, while effects are reduced with increasing nanowire cross-sectional size or aspect ratio. Most importantly, due to the existence of the beat phenomena, we demonstrate that in resonance experiments only a single frequency component is expected to be observed, particularly when the damping ratio is relatively large or very small. Furthermore, for a large range of actuation angles, the lower frequency is more likely to be detected than the higher one, which implies that experimental predictions of the Young's modulus obtained from resonance may in fact be under-predictions. The present study therefore has significant implications for experimental interpretations of the Young's modulus as obtained via resonance testing. Electronic supplementary information (ESI) available: (1) Summary of all numerical testing results and (2) some corresponding derivation details. See DOI: 10.1039/c2nr31545a

Zhan, Haifei; Gu, Yuantong; Park, Harold S.

2012-10-01

63

Measurements of extreme physical phenomena by Fourier fringe analysis, a review: from sub-Ångstrom lattice distortion measurement to attosecond pulse phase measurement  

NASA Astrophysics Data System (ADS)

In this talk we review and introduce some of the examples of successful applications of the Fourier transform method (FTM) of fringe pattern analysis to the measurements of extreme physical phenomena, such as those involving ultra fast optical pulses, extremely small atomic displacements, and unconventional electron wave or EUV light, and show how the advantages of FTM are exploited in these cutting edge application areas.

Takeda, Mitsuo

2011-08-01

64

Optical measurement and scaling of blasts from gram-range explosive charges  

Microsoft Academic Search

Laboratory-scale experiments with gram-range explosive charges are presented. Optical shadowgraphy and high-speed digital\\u000a imaging are used to measure the explosive-driven shock-wave position as a function of time. From this, shock Mach number-versus-distance\\u000a from the explosion center can be found. These data then yield the peak overpressure and duration, which are the key parameters\\u000a in determining the potential damage from an

Michael J. Hargather; Gary S. Settles

2007-01-01

65

Development of a three-dimensional PIV measurement technique for the experimental study of air bubble collapse phenomena  

SciTech Connect

Particle image velocimetry (PIV) is a quantitative flow measurement technique. The objective of this study is to develop a new three-dimensional PIV technique for the experimental study of air bubble collapse phenomena. A three-dimensional measurement technique is necessary since bubble collapse is a three-dimensional phenomenon. The investigation of the velocity flow field around a collapsing air bubble can provide detailed three-dimensional quantitative information to help improve the understanding of the related heat transfer processes.

Yang, Y.H.; Hassan, Y.A.; Schmidl, W.D. [Texas A& M Univ., College Station, TX (United States)

1995-12-31

66

Is a Simple Measurement Task a Roadblock to Student Understanding of Wave Phenomena?  

ERIC Educational Resources Information Center

We present results from our ongoing investigation of student understanding of periodic waves and interference phenomena at the introductory physics level. We have found that many students experience significant difficulties when they attempt to express a distance of interest in terms of the wavelength of a periodic wave. We argue that for these…

Kryjevskaia, Mila; Stetzer, MacKenzie R.; Heron, Paula R. L

2012-01-01

67

Accuracy and Response of Tourmaline Gages for Measurement of Underwater Explosion Phenomena.  

National Technical Information Service (NTIS)

Tourmaline gages have been used for some time to record and study underwater shock phenomena from explosions. Tourmaline is unique in that its piezoelectric constants are the same polarity. It does not require constraint in one dimension and thus, a diaph...

R. B. Tussing

1982-01-01

68

PROTECTIVE DESIGNS FOR BLAST AND IMPACT THREATS  

Microsoft Academic Search

This paper describes methods for designing and implementing protective technologies for improving the blast and impact resistance of buildings. A protection plan for buildings may include designing blast-resistant columns, walls, and windows; other elements of security may also play a major part, including physical security measures such as: anti-ram barriers and fencing to demarcate a protective perimeter; features such as

J. E. Crawford

69

Copper staves in the blast furnace  

Microsoft Academic Search

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

R. G. Helenbrook; W. Kowalski; K. H. Grosspietsch; H. Hille

1996-01-01

70

Paranormal phenomena  

NASA Astrophysics Data System (ADS)

Critical analysis is given of some paranormal phenomena events (UFO, healers, psychokinesis (telekinesis))reported in Moldova. It is argued that correct analysis of paranormal phenomena should be made in the framework of electromagnetism.

Gaina, Alex

1996-08-01

71

Near-Sun solar wind consequences of solar structure and dynamic phenomena observed by radio scintillation measurements  

NASA Technical Reports Server (NTRS)

Since radio propagation measurements using either natural or spacecraft radio signals are used for probing the solar wind in the vicinity of the sun, they represent a key tool for studying the interplanetary consequences of solar structure and dynamic phenomena. New information on the near sun consequences was obtained from radio scintillation observations of coherent spacecraft signals. The results covering density fluctuations, fractional density fluctuations, coronal streamers, heliospheric current sheets, coronal mass ejections and interplanetary shocks are reviewed. A joint ICE S-band (13 cm wavelength) Doppler scintillation measurement with the SOHO white-light coronograph (LASCO) is described.

Woo, Richard

1994-01-01

72

Modern BLAST Programs  

NASA Astrophysics Data System (ADS)

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.

Ma, Jian; Zhang, Louxin

73

Blast investigation by fast multispectral radiometric analysis  

NASA Astrophysics Data System (ADS)

Knowledge regarding the processes involved in blasts and detonations is required in various applications, e.g. missile interception, blasts of high-explosive materials, final ballistics and IED identification. Blasts release large amount of energy in short time duration. Some part of this energy is released as intense radiation in the optical spectral bands. This paper proposes to measure the blast radiation by a fast multispectral radiometer. The measurement is made, simultaneously, in appropriately chosen spectral bands. These spectral bands provide extensive information on the physical and chemical processes that govern the blast through the time-dependence of the molecular and aerosol contributions to the detonation products. Multi-spectral blast measurements are performed in the visible, SWIR and MWIR spectral bands. Analysis of the cross-correlation between the measured multi-spectral signals gives the time dependence of the temperature, aerosol and gas composition of the blast. Farther analysis of the development of these quantities in time may indicate on the order of the detonation and amount and type of explosive materials. Examples of analysis of measured explosions are presented to demonstrate the power of the suggested fast multispectral radiometric analysis approach.

Devir, A. D.; Bushlin, Y.; Mendelewicz, I.; Lessin, A. B.; Engel, M.

2011-05-01

74

Insulation Phenomena of Compressed Air  

Microsoft Academic Search

Test data on impulse and 60-cycle voltage breakdown strength for compressed air with various electrode configurations are reported. The tests were made with rod-to-plane electrodes with spacings up to 8 inches and pressures to 250 psig (pounds per square inch gage). Breakdown phenomena of air insulation encountered in the development of an air insulated air-blast circuit breaker1 are reported. The

L. D. McConnell

1957-01-01

75

Blasting injuries in surface mining with emphasis on flyrock and blast area security  

Microsoft Academic Search

Problem: Blasting is a hazardous component of surface mining. Serious injuries and fatalities result from improper judgment or practice during rock blasting. This paper describes several fatal injury case studies, analyzes causative factors, and emphasizes preventive measures. Method: This study examines publications by MSHA, USGS, and other authors. The primary source of information was MSHA's injury-related publications. Results: During the

T. S. Bajpayee; T. R. Rehak; G. L. Mowrey; D. K. Ingram

2004-01-01

76

Experiences with computer systems in blast furnace operation control at Rautaruukki  

SciTech Connect

Low energy consumption, together with high productivity and stable blast furnace operation, has been achieved at Rautaruukki's Raahe Steel Works as a result of the efficient use of computer technology in process control and improvements in raw materials quality. The blast furnace supervision system is designed to support the decision-making in medium and long-term process control. The information presenting the blast furnace operation phenomena is grouped so that little time is needed to obtain the current state of the process. Due to the complexity of the blast furnace process, an expert system to guide and diagnose the short and medium-term blast furnace operation has been developed.

Inkala, P.; Karppinen, A. (Rautaruukki Oy, Raahe (Finland). Raahe Steel Works); Seppanen, M. (Rautaruukki Oy Engineering, Oulu (Finland))

1994-09-01

77

Blast Vibration: Threshold Values and Vibration Control.  

National Technical Information Service (NTIS)

A proposal for Finnish blast vibration standards and a calculation model for the extent of the zones for building inspection, risk analysis, and vibration measurements are given. The international conclusion is that particle velocity is the best descripti...

R. Vuolio

1990-01-01

78

Blast furnace stove control  

SciTech Connect

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.

Muske, K.R. [Villanova Univ., PA (United States). Dept. of Chemical Engineering; Hansen, G.A.; Howse, J.W.; Cagliostro, D.J. [Los Alamos National Lab., NM (United States); Chaubal, P.C. [Inland Steel Industries Inc., East Chicago, IN (United States). Research Labs.

1998-12-31

79

Assessment of Atmospheric Emissions from Quenching of Blast Furnace Slag with Blast Furnace Blowdown Water.  

National Technical Information Service (NTIS)

The report gives results of 15 emission measurements made on a laboratory scale facility simulating typical plant slag quenching practice. The measurements were made to determine if a potential alternative to treatment prior to discharge of blast furnace ...

G. Annamraju W. Kemner P. J. Schworer

1984-01-01

80

Nineteen-Foot Diameter Explosively Driven Blast Simulator  

SciTech Connect

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.

VIGIL,MANUEL G.

2001-07-01

81

Confined volume blasting experiments: Description and analysis  

SciTech Connect

A series of bench-scale blasting experiments was conducted to produce rubble beds for use in retorting experiments. The experiments consisted of blasting oil shale with explosives within a confined volume containing 25% void. A variety of blasting geometries was used to control the fragment size distribution and void distribution in the rubble. The series of well controlled tests provided excellent data for use in validating rock fragmentation models. Analyses of the experiments with PRONTO, a dynamic finite element computer code, and a newly developed fracturing model provided good agreement between code predictions and experimental measurements of fracture extent and fragment size. CAROM, a dynamic distinct element code developed to model rock motion during blasting, was used to model the fully fragmented tests. Calculations of the void distribution agreed well with experimentally measured values. 9 refs., 11 figs., 1 tab.

Gorham-Bergeron, E.; Kuszmaul, J.S.; Bickel, T.C.; Shirey, D.L.

1987-01-01

82

Investigation of Critical Phenomena with Precision Density Measurements in Liquid Helium near the Lambda Transition  

NASA Astrophysics Data System (ADS)

We demonstrate how precision measurements can improve the resolution of experimentally determined critical exponents and relevant coefficients near phase transitions. Using a high-Q (10^10) microwave cavity together with high-resolution (one part in 10^9) thermometry (HRT) and high-resolution frequency read-out (to one part in 10^13) techniques, we have estimated the precision achievable in the density measurement in helium near the lambda transition (T_?). With a density resolution of one part in 10^10, we evaluate the resolution in the critical exponent ? and the amplitude coefficients of the thermal expansion coefficient ?P near T_?. We conclude that improvements can be made with our precision density measurements. Furthermore, the accuracy of ? and the leading amplitude coefficient can be improved by restricting the data analysis to the critical region determined by the Ginzberg criterion. Preliminary experimental results using a high-Q niobium cavity will be presented.

Jiang, Wen; Strayer, Donald M.; Yeh, Nai-Chang; Asplund, Nils

1997-03-01

83

Expanded rock blast modeling capabilities of DMC{_}BLAST, including buffer blasting  

Microsoft Academic Search

A discrete element computer program named DMC{_}BLAST (Distinct Motion Code) has been under development since 1987 for modeling rock blasting. This program employs explicit time integration and uses spherical or cylindrical elements that are represented as circles in 2-D. DMC{_}BLAST calculations compare favorably with data from actual bench blasts. The blast modeling capabilities of DMC{_}BLAST have been expanded to include

D. S. Preece; J. P. Tidman; S. H. Chung

1996-01-01

84

Wetting phenomena of mercury on sapphire studied by optical emissivity measurement  

Microsoft Academic Search

We have carried out simultaneous measurements of the optical reflectivity and the thermal radiation for the mercury-sapphire system. We have found that the optical emissivity shows remarkable changes not only at the liquid-gas transition but also at the prewetting transition of mercury on the sapphire substrate. Furthermore, in the prewetting supercritical phase, a sharp dip in the emissivity is observed,

Y. Ohmasa; Y. Kajihara; H. Kohno; Y. Hiejima; M. Yao

2000-01-01

85

An accurate frequency measuring technique using paramagnetic resonance phenomena in the X-band region  

Microsoft Academic Search

This paper presents a method of measuring frequency in the microwave region by comparing it to a very stable low frequency standard. The technique described here was used to calibrate a cavity wavemeter for an experiment in microwave spectroscopy. The calibration procedure is based on the use of electron and nuclear resonances as they are observed in the presence of

P. Crandell

1958-01-01

86

Blast furnace reactions  

Microsoft Academic Search

Vast a dvances h ave b een m ade in blast-furnace t echnology d uring t he p ast two decades through p lant t rials and plant d evelopments a ssisted by research to provide b etter u nderstanding of physical and chemical w orkings of the blast f urnace. T he f ields of research have i ncluded

E. T. Turkdogan

1978-01-01

87

Fracture process in blasting  

Microsoft Academic Search

In order to clarify the respective roles of stress wave and gas pressure in the fragmentation of an underground blast the fracture process in the zone immediately around the borehole was studied by separating the 2 principal blast forces analytically and experimentally. In model tests the explosion wave was simulated by the pulse generated by an underwater spark discharge, and

H. K. Kutter; C. Fairhurst

1971-01-01

88

Computer cast blast modelling  

Microsoft Academic Search

Cast blasting can be designed to utilize explosive energy effectively and economically for coal mining operations to remove overburden material. The more overburden removed by explosives, the less blasted material there is left to be transported with mechanical equipment, such as draglines and trucks. In order to optimize the percentage of rock that is cast, a higher powder factor than

S. Chung; M. McGill; D. S. Preece

1994-01-01

89

Lightweight blast shield  

DOEpatents

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.

Mixon, Larry C. (Madison, AL); Snyder, George W. (Huntsville, AL); Hill, Scott D. (Toney, AL); Johnson, Gregory L. (Decatur, AL); Wlodarski, J. Frank (Huntsville, AL); von Spakovsky, Alexis P. (Huntsville, AL); Emerson, John D. (Arab, AL); Cole, James M. (Huntsville, AL); Tipton, John P. (Huntsville, AL)

1991-01-01

90

Toxicology of blast overpressure  

Microsoft Academic Search

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

Nabil M. Elsayed

1997-01-01

91

Blast overpressures from medium scale BLEVE tests  

Microsoft Academic Search

The measured blast overpressures from recent tests involving boiling liquid expanding vapour explosions (BLEVE) has been studied. The blast data came from tests where 0.4 and 2m3 ASME code propane tanks were exposed to torch and pool fires. In total almost 60 tanks were tested, and of these nearly 20 resulted in catastrophic failures and BLEVEs. Both single and two-step

A. M. Birk; C. Davison; M. Cunningham

2007-01-01

92

Flight-measured laminar boundary-layer transition phenomena including stability theory analysis  

NASA Technical Reports Server (NTRS)

Flight experiments were conducted on a single-engine turboprop aircraft fitted with a 92-in-chord, 3-ft-span natural laminar flow glove at glove section lift coefficients from 0.15 to 1.10. The boundary-layer transition measurement methods used included sublimating chemicals and surface hot-film sensors. Transition occurred downstream of the minimum pressure point. Hot-film sensors provided a well-defined indication of laminar, laminar-separation, transitional, and turbulent boundary layers. Theoretical calculations of the boundary-layer parameters provided close agreement between the predicted laminar-separation point and the measured transition location. Tollmien-Schlichting (T-S) wave growth n-factors between 15 and 17 were calculated at the predicted point of laminar separation. These results suggest that for many practical airplane cruise conditions, laminar separation (as opposed to T-S instability) is the major cause of transition in predominantly two-dimensional flows.

Obara, C. J.; Holmes, B. J.

1985-01-01

93

The atmosphere UV background phenomena measured by detector on-board ``Tatiana'' satellite  

NASA Astrophysics Data System (ADS)

Near UV detector on-board the “Universitetsky-Tatiana” satellite has observed the atmosphere glow at night side of the Earth. Digital oscilloscopes help to select transient luminous events and to measure their temporal profiles in time scale of 1-64 ms. Data from those detectors were analyzed for prediction the duty cycle of future space detectors of ultra high energy cosmic rays.

Klimov, P. A.; Garipov, G. K.; Khrenov, B. A.; et al.

94

Modelling of transient state phenomena of composite superconducting conductors during pulse Ic(B) measurements  

Microsoft Academic Search

Computational modelling of pulsed current characterisation in composite superconducting conductors has been performed as the first step towards understanding the electromagnetic processes occurring during pulse Ic(B) measurements in the Cryo-BI-Pulse System. A simplified 2D model was created using the Finite Element Method (FEM) software ANSYS to investigate the current transfer process in a multifilamentary conductor, resulting in time dependent 2D

S. Krosny; M. Wozniak; S. C. Hopkins; M. A. Stepien; B. Grzesik; B. A. Glowacki

2010-01-01

95

System for supplying blasting media to a media blasting system  

Microsoft Academic Search

This patent describes a pressure pot system for supplying blasting media under pressure to a pressurized blasting conduit for feeding blasting media to one or more blasting guns, the system including a media storage means and a first and second pressure chambers with means for pressurizing and exhausting the first and second chambers, the media storage means being stacked above

Van Kuiken; L. L. Jr

1988-01-01

96

Using models and measurements to describe ultrawideband radar-scattering phenomena  

NASA Astrophysics Data System (ADS)

The Army Research Laboratory (ARL) has been developing ultra wideband (UWB), ultra wide angle radar technology to meet warfighter requirements to detect concealed targets (such as tactical vehicles under foliage). Experiments undertaken by ARL and others using testbed radar's (such as ARL's BoomSAR) have shown significant potential for detecting hidden targets. Initial evaluations have concentrated on identifying the 'contrast' ratios for desired targets versus average background. In more recent work, we have begun to evaluate specific angle, frequency, and/or polarization-based scattering properties of targets and clutter to isolate discrimination features for use in automatic target detection and cuing (ATD/C) algorithms (see reference 1). Though promising, much of this work has been ad hoc and based on small data sets that have only recently become available. To complement the measurements and analysis effort under way at ARL, our team is also developing high-fidelity electromagnetic models of targets and certain classes of clutter to gain a physics-based insight into robust discrimination techniques. We discuss recent analysis of both EM model results as well as a unique inverse synthetic aperture radar (ISAR) collection undertaken at Aberdeen Proving Ground (APG). By creating a phenomenological framework for explaining and/or describing target and/or clutter backscatter behavior and comparing it with measured field data, we can develop detection strategies inspired by the unique physics of low-frequency radar. Finally, we suggest one such detection paradigm.

Sichina, Jeffrey; Nguyen, Lam H.; Sullivan, Anders J.

2000-08-01

97

Hydromagnetic wavelike phenomena from Helios time delay measurements by remote sensing  

NASA Technical Reports Server (NTRS)

A survey of the electron content measurements during solar occultations of the Helios A and B spacecraft is presented, and a spectral analysis using the method of maximum entropy is discussed. Typical variations measured are on the order of 0.1-1.8 x 10 to the 18th/sq m, while typical values for the rate of change are 0.7-50 x 10 to the 13th per sq m per sec. Numerical results in agreement with findings from Helios radio science, reveal a fundamental period of about 70 minutes superimposed by minor spectral peaks corresponding to shorter time periods such as 35 and 25 minutes. In addition, the periodicities observed in electron content are discussed in terms of fast hydromagnetic waves excited by nonlinear Alfven waves via coupling terms before crossing the Helios ray path. It is noted that for the first time experimental evidence is presented that hydromagnetic waves may actually be propagating from the solar corona into the interplanetary medium.

Edenhofer, P.; Esposito, P. B.; Lueneburg, E.

1980-01-01

98

Characterization of Side Load Phenomena Using Measurement of Fluid/Structure Interaction  

NASA Technical Reports Server (NTRS)

During ground-tests of most production rocket engines over the last 30 years, large asymmetric transient side loads coming from the nozzle and related steady-state vibrational loads within the nozzle have been measured. The widely varying magnitude of these loads has been large enough to fail interfacing components as well as nozzles in these engines. This paper will discuss a comprehensive test and analysis program that has been undertaken to develop a methodology to accurately predict the character and magnitude of this loading. The project to-date has incorporated analytical modeling of both the fluid flow and the nozzle structure and testing of both full-scale and sub-scale rocket nodes. Examination of the test data indicates that one of the two-nodal diameter structural modes may be interacting with flow separation from the nozzle inside-wall in a self-excited or aeroelastic vibration phenomenon. If verified, this observation will be used to develop a methodology for design and analysis. A fuller understanding of the characteristics of this vibration will provide an increase in the accuracy and confidence of side load predictions, which will be critical for the successful construction of the next generation of low-cost, reliable rocket engines.

Brown, Andrew M.; Ruf, Joseph; Reed, Darren; DAgostino, Mark; Keanini, Russell; McConnaughey, Paul K. (Technical Monitor)

2002-01-01

99

New blast weapons.  

PubMed

Over the last decade a large number of weapon systems have appeared that use blast as their primary damage mechanism. This is a notable trend; until recently very few warheads relied on blast as their primary output. Most warheads in service use explosives to drive metal such as fragments and shaped charge jets to engage targets. New technologies are now being integrated into warheads that claim to have enhanced blast performance. Blast weapons could have been designed to fill a gap in capability; they are generally used for the attack of 'soft' targets including personnel, both in the open and within protective structures. With the increased number and range of these weapons, it is likely that UK forces will have to face them in future conflicts. This paper briefly describes fuel-air explosive blast weapons and reviews a range of enhanced blast weapons that have been developed recently. The paper concludes with a brief discussion on the reasons why enhanced blast technologies may be proliferating and how this could affect the Defence Medical Services. PMID:11307681

Dearden, P

2001-02-01

100

Passive blast pressure sensor  

SciTech Connect

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.

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

2013-03-19

101

Effects of mine blasting on residential structures  

SciTech Connect

Blasting is common in the coal industry to remove rock overburden so that the exposed coal can be mechanically excavated. The ground vibrations and air blast produced by blasting are often felt by residents surrounding the mines. There has been a trend for regulatory authorities, especially those concerned with the environment, to impose low limits on blast vibration levels in response to community pressure, based on human perception and response to vibration. This paper reports the findings of an extensive study on a house which was located adjacent to a coal mine. The house was monitored for over 1 year and was subjected to ground peak particle velocity (PPV) ranging from 1.5 to 222 mm/s. The house was instrumented with accelerometers to measure its dynamic response due to blasting and it was also monitored for cracks before and after each blast. Based on this study, ground motion amplifications along the height of the structure have been established. A simplified methodology presented in this paper has been used to estimate the ground PPV at which cracking is likely.

Gad, E.F.; Wilson, J.L.; Moore, A.J.; Richards, A.B. [Swinburne University of Technology, Hawthorn, Vic. (Australia). Faculty of Engineering & Industrial Science

2005-08-01

102

Auswirkung von Staubexplosionen auf die Umgebung druckentlasteter Anlagenteile (Phase 2). Abschlussbericht. (Measurement of pressure blast effects and fireball sizes from vented dust explosions (Phase 2). Final report).  

National Technical Information Service (NTIS)

Explosion venting used to protect facilities may cause secondary blast and fire effects outside, against which people or nearby installations have to be protected. In phase 2 of the project, explosion venting for different dust materials (hard coal, maize...

S. Schumann A. Rastogi V. Friehmelt H. Fogt W. Haas

1995-01-01

103

ESF BLAST DESIGN ANALYSIS  

SciTech Connect

The purpose and objective of this design analysis are to develop controls considered necessary and sufficient to implement the requirements for the controlled drilling and blasting excavation of operations support alcoves and test support alcoves in the Exploratory Studies Facility (ESF). The conclusions reached in this analysis will flow down into a construction specification ensuring controlled drilling and blasting excavation will be performed within the bounds established here.

E.F. fitch

1995-03-13

104

Software Verification with BLAST  

Microsoft Academic Search

Abstract: Introduction. Blast (the Berkeley Lazy Abstraction Software verificationTool) is a verification system for checking safety properties of C programs usingautomatic property-driven construction and model checking of software abstractions. Blast implements an abstract-model check-refine loop to check forreachability of a specified label in the program. The abstract model is built onthe fly using predicate abstraction. This model is then checked

Thomas A. Henzinger; Ranjit Jhala; Rupak Majumdar; Grégoire Sutre

2003-01-01

105

Role of computer simulation in oil shale blasting  

SciTech Connect

Sophisticated computer codes were developed to simulate the processes that occur in blasting in oil shale. Three ways these codes are used in conjunction with field results are described. First, there is a code verification stage, where the code is improved through detailed comparisons. Next, there is a stage where critical phenomena in the blasting process are identified by studying areas where there are significant differences between calculations and field results. Finally, as the code is verified and the critical phenomena are explored, the code is used as a design tool. These stages are illustrated with experience from use of the new Los Alamos SHALE code and other codes. Current understanding of blasting in oil shale is reviewed, with an emphasis on areas where simulations and experimental approaches are pushed to their limits. A recommendation is made that computer simulation be done in close coordination with an active experimental program.

Adams, T.F.; Keller, C.F.

1984-01-01

106

The role of computer simulation in oil shale blasting  

SciTech Connect

Sophisticated computer codes have been developed to simulate the processes that occur in blasting in oil shale. The authors describe the three ways these codes are used in conjunction with field results. First, there is a code verification stage, where the code is improved through detailed comparisons. Next, there is a stage where critical phenomena in the blasting process are identified by studying areas where there are significant differences between calculations and field results. Finally, as the code is verified and the critical phenomena are explored, the code is used as a design tool. These stages are illustrated with experience from use of the new Los Alamos SHALE code and other codes. Current understanding of blasting in oil shale is reviewed, with an emphasis on areas where simulations and experimental approaches are pushed to their limits. It is concluded that computer simulation be done in close coordination with an active experimental program.

Adams, T.F.; Keller, C.F.

1984-04-01

107

Blast-wave characteristics near Site 300  

SciTech Connect

The blast-wave overpressures propagating in the atmosphere near the Lawrence Livermore National Laboratory (LLNL) Site 300 have been measured at selected locations to determine whether the Site 300 blast operations will be hindered by the proposed construction of a residential development adjacent to its border.We tested high-explosives (HE) weights ranging from 14 to 545 lb under various weather conditions. Although more tests should be conducted before a definitive statement can be made on the blast propagation near Site 300, we offer the following preliminary interpretation of the results obtained to date. The readings at the closest locations show that the blast-wave overpressures exceed the 126-decibel (dB) level established by LLNL at about 250 lb of HE detonation. The weather conditions do not materially affect the pressure levels at these locations. Insufficient test data exist along the Corral Hollow Road perimeter, making it difficult to reasonably predict HE blast effects along the southern border. Therefore, we recommend that additional measurements be made along this and other boundaries in future tests, to provide more comprehensive data to help determine the blast-wave propagation characteristics in the proposed development areas. Blast-wave focusing may occur in the proposed residential development area under certain weather conditions. We recommend that this possibility should be addressed for its potentially adverse impact on the proposed residential area. Because the testing ground controlled by Physics International, Inc. (PI) is adjacent to Site 300, it is important to be aware of PI`s detonation activities. Peak overpressure measurements near PI`s Corral Hollow Road entrance reveal that PI shots over 25 lb HE have exceeded 126 dB, the limit established by LLNL for safe operations.

Kang, Sang-Wook; Kleiber, J.C. Jr.

1993-08-01

108

A 3D CFD simulation of liquid flow in an ironmaking blast furnace  

NASA Astrophysics Data System (ADS)

A three-dimensional CFX-based mathematical model is developed to describe the flow-heat transfer-chemical reactions behaviours of gas-solid-liquid phases in an ironmaking blast furnace (BF), where the raceway cavity is considered explicitly. The typical in-furnace phenomena of an operating blast furnace, in particular, the liquid flow in the lower part of a blast furnace is simulated in aspects of velocity and volume fraction. This model offers a cost-effective tool to understand and optimize blast furnace operation.

Shen, Yansong; Guo, Baoyu; Chew, Sheng; Austin, Peter; Yu, Aibing

2013-07-01

109

Quasi-elastic Laser Scattering for Measuring Inhomogeneous Interfacial Tension in Non-equilibrium Phenomena with Convective Flows.  

PubMed

An inhomogeneous distribution of interfacial tension can induce different types of non-equilibrium spontaneous motion at the interface by convective flow, or by the solutal Marangoni effect. Several applications of the quasi-elastic laser scattering (QELS) method used to study these effects are presented here. The relationship between the interfacial tension and the non-equilibrium phenomena has been verified experimentally for each application. In a water/nitrobenzene oscillatory system with continuous surfactant addition to the interface, the local adsorption of surfactants at the interface has been demonstrated and shown to be strongly related to the presence of electrolytes. In a donor/membrane/acceptor system, the dual-beam QELS method shows that surfactant adsorption at the membrane/acceptor interface is responsible for oscillations in the electric potential. The differences in the adsorption/desorption behavior of metal complex catalysts between air/liquid and liquid/liquid interfaces were considered in the propagating chemical waves of the Belousov-Zhabotinsky reaction. We successfully measured the distribution of interfacial tension around a self-propelled camphor boat and an alcohol droplet floating on an aqueous phase, and compared the mechanisms of their motion. PMID:25007928

Nomoto, Tomonori; Toyota, Taro; Fujinami, Masanori

2014-01-01

110

Measurements of Channel Transfer Functions and Capacity Calculations for a 16X16 BLAST Array over a Ground Plane.  

National Technical Information Service (NTIS)

Wideband channel transfer function measurements were made for a 16- element transmit and 16-element receive, multiple input, multiple output (MIMO) antenna array. The measurements were conducted using the National Institute of Standards and Technology (NI...

P. B. Papazian Y. Lo J. J. Lemmon M. J. Gans

2003-01-01

111

Evolution of blast wave profiles in simulated air blasts: experiment and computational modeling  

NASA Astrophysics Data System (ADS)

Shock tubes have been extensively used in the study of blast traumatic brain injury due to increased incidence of blast-induced neurotrauma in Iraq and Afghanistan conflicts. One of the important aspects in these studies is how to best replicate the field conditions in the laboratory which relies on reproducing blast wave profiles. Evolution of the blast wave profiles along the length of the compression-driven air shock tube is studied using experiments and numerical simulations with emphasis on the shape and magnitude of pressure time profiles. In order to measure dynamic pressures of the blast, a series of sensors are mounted on a cylindrical specimen normal to the flow direction. Our results indicate that the blast wave loading is significantly different for locations inside and outside of the shock tube. Pressure profiles inside the shock tube follow the Friedlander waveform fairly well. Upon approaching exit of the shock tube, an expansion wave released from the shock tube edges significantly degrades the pressure profiles. For tests outside the shock tube, peak pressure and total impulse reduce drastically as we move away from the exit and majority of loading is in the form of subsonic jet wind. In addition, the planarity of the blast wave degrades as blast wave evolves three dimensionally. Numerical results visually and quantitatively confirm the presence of vortices, jet wind and three-dimensional expansion of the planar blast wave near the exit. Pressure profiles at 90° orientation show flow separation. When cylinder is placed inside, this flow separation is not sustained, but when placed outside the shock tube this flow separation is sustained which causes tensile loading on the sides of the cylinder. Friedlander waves formed due to field explosives in the intermediate-to far-field ranges are replicated in a narrow test region located deep inside the shock tube.

Chandra, N.; Ganpule, S.; Kleinschmit, N. N.; Feng, R.; Holmberg, A. D.; Sundaramurthy, A.; Selvan, V.; Alai, A.

2012-09-01

112

Integrated, Multi-Scale Characterization of Imbibition and Wettability Phenomena Using Magnetic Resonance and Wide-Band Dielectric Measurements  

SciTech Connect

The petrophysical properties of rocks, particularly their relative permeability and wettability, strongly influence the efficiency and the time-scale of all hydrocarbon recovery processes. However, the quantitative relationships needed to account for the influence of wettability and pore structure on multi-phase flow are not yet available, largely due to the complexity of the phenomena controlling wettability and the difficulty of characterizing rock properties at the relevant length scales. This project brings together several advanced technologies to characterize pore structure and wettability. Grain-scale models are developed that help to better interpret the electric and dielectric response of rocks. These studies allow the computation of realistic configurations of two immiscible fluids as a function of wettability and geologic characteristics. These fluid configurations form a basis for predicting and explaining macroscopic behavior, including the relationship between relative permeability, wettability and laboratory and wireline log measurements of NMR and dielectric response. Dielectric and NMR measurements have been made show that the response of the rocks depends on the wetting and flow properties of the rock. The theoretical models can be used for a better interpretation and inversion of standard well logs to obtain accurate and reliable estimates of fluid saturation and of their producibility. The ultimate benefit of this combined theoretical/empirical approach for reservoir characterization is that rather than reproducing the behavior of any particular sample or set of samples, it can explain and predict trends in behavior that can be applied at a range of length scales, including correlation with wireline logs, seismic, and geologic units and strata. This approach can substantially enhance wireline log interpretation for reservoir characterization and provide better descriptions, at several scales, of crucial reservoir flow properties that govern oil recovery.

Mukul M. Sharma; Steven L. Bryant; Carlos Torres-Verdin; George Hirasaki

2007-09-30

113

Indoor human response to blast sounds that generate rattles.  

PubMed

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

Schomer, P D; Averbuch, A

1989-08-01

114

Removal of phosphate from aqueous solution with blast furnace slag  

Microsoft Academic Search

Blast furnace slag was used to remove phosphate from aqueous solutions. The influence of pH, temperature, agitation rate, and blast furnace slag dosage on phosphate removal was investigated by conducting a series of batch adsorption experiments. In addition, the yield and mechanisms of phosphate removal were explained on the basis of the results of X-ray spectroscopy, measurements of zeta potential

Ensar Oguz

2004-01-01

115

Copper staves in the blast furnace  

SciTech Connect

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.

Helenbrook, R.G. [ATSI, Inc., Amherst, NY (United States); Kowalski, W. [Thyssen Stahl AG, Duisburg (Germany); Grosspietsch, K.H. [Preussag Stahl AG, Saltzgitter (Germany); Hille, H. [MAN GHH AG, Oberhausen (Germany)

1996-08-01

116

Development Of An Experiment For Measuring Flow Phenomena Occurring In A Lower Plenum For VHTR CFD Assessment  

SciTech Connect

The objective of the present report is to document the design of our first experiment to measure generic flow phenomena expected to occur in the lower plenum of a typical prismatic VHTR (Very High Temperature Reactor) concept. In the process, fabrication sketches are provided for the use of CFD (computational fluid dynamics) analysts wishing to employ the data for assessment of their proposed codes. The general approach of the project is to develop new benchmark experiments for assessment in parallel with CFD and coupled CFD/systems code calculations for the same geometry. One aspect of the complex flow in a prismatic VHTR is being addressed: flow and thermal mixing in the lower plenum ("hot streaking" issue). Current prismatic VHTR concepts were examined to identify their proposed flow conditions and geometries over the range from normal operation to decay heat removal in a pressurized cooldown. Approximate analyses were applied to determine key non-dimensional parameters and their magnitudes over this operating range. The flow in the lower plenum can locally be considered to be a situation of multiple jets into a confined crossflow -- with obstructions. Flow is expected to be turbulent with momentum-dominated turbulent jets entering; buoyancy influences are estimated to be negligible in normal full power operation. Experiments are needed for the combined features of the lower plenum flows. Missing from the typical jet experiments available are interactions with nearby circular posts and with vertical posts in the vicinity of vertical walls - with near stagnant surroundings at one extreme and significant crossflow at the other.

D. M. McEligot; K.G. Condie; G. E. Mc Creery; H. M. Mc Ilroy

2005-09-01

117

Secondary Waves from Nozzle Blast.  

National Technical Information Service (NTIS)

Blast signatures at the gunner's position produced by recoilless rifles and rocket launchers often exhibit a strong secondary wave following chamber blowdown. To identify its source a series of experiments was performed using a helium-driven blast simulat...

G. C. Carofano

1984-01-01

118

Proceedings of the tenth annual symposium on explosives and blasting research  

SciTech Connect

These proceedings contain 26 papers presented at the conference. Topics relate to blast vibration analysis and modeling, malfunctioning explosives, detonators, rock fragmentation, structural response of buildings to blasting, computer modeling, blast design, and measurement of rock properties. Most of the papers have been processed separately for inclusion on the data base.

NONE

1994-12-31

119

Controlled blasting and its implications for the NNWSI project exploratory shaft  

SciTech Connect

This report reviews controlled blasting techniques for shaft sinking. Presplitting and smooth blasting are the techniques of principal interest. Smooth blasting is preferred for the Nevada Nuclear Waste Storage Investigations exploratory shaft. Shaft damage can be monitored visually or by peak velocity measurements and refractive techniques. Damage into the rock should be limited to 3 ft. 40 refs., 22 figs., 7 tabs.

Van Eeckhout, E.M.

1987-09-01

120

Rainbow phenomena: Development of a laser-based, non- intrusive technique for measuring droplet size, temperature and velocity  

NASA Astrophysics Data System (ADS)

Liquid sprays appear in a variety of aerospace, automotive and industrial applications. In order to be able to employ the optimal spray configuration it is essential that one first develops a complete understanding of the fundamental phenomena that influence and control the overall spray performance for such applications. Toward this end, the development of advanced diagnostic tools is necessary for studying spray processes in both ideal laboratory conditions and realistic environments. The objective of the thesis was to study the first-order rainbow and to apply it to the non-intrusive determination of droplet parameters in spray environments. The first-order rainbow is created in the laboratory by droplets scattering laser light and this is therefore monochromatic. The effect of size and temperature (and thereby refractive index) of spherical droplets on the rainbow characteristics have been predicted by the Lorenz-Mie and Airy theories. Experiments on satellite droplets around an unstable water jet, performed with a linear CCD-camera, have revealed the effect of droplet non-sphericity on the accuracy of the temperature and size measurements. To understand this effect better, a surface integral method has been developed which describes the behaviour of the rainbow for an ellipsoidal scatterer. The theoretical approach is based on the vectorial Kirchhoff integral relation taken over the electric field on the droplet surface, with the electric field obtained using ray- optics. The integral has been solved by looking for the ridge of stationary points in the integrand of the Kirchhoff integral. A comparison with the Lorenz-Mie theory has validated the approach in the special case of spherical scatterers. The surface integral method endorses the experimental non-sphericity detection method that selects, using the rainbow pattern, spherical droplets. This method has considerably improved the accuracy of the droplet parameters measured using the rainbow technique. A rainbow detection device has been developed for measuring simultaneously the size, temperature and velocity of individual spherical droplets in liquid sprays. The rainbow is recorded by a photomultiplier placed behind a pin hole and a spatial filter containing a wire perpendicular to the scattering plane. The wire diffraction and rainbow interference patterns move in front of the pin hole as the droplet traverses the laser beam. Preliminary experiments in a full-cone water spray at isothermal conditions revealed the feasibility of the device in spray environments and stressed the importance of the non-sphericity detection method.

van Beeck, Jeronimus Petrus Antonius Johannes

121

Blasting: Another environmental woe  

NASA Astrophysics Data System (ADS)

The much increased use of explosives to move and extract rock masses in construction and mining over the past two decades has resulted in a plethora of complaints from the general public in areas of close proximity to public facilities, communication, and transportation systems. Air blasts and ground vibrations caused by explosive detonation can have desultory and damaging effects to public and private property, impose adverse effects on underground mining operations, and change the course of flow or effect the availability of surface and groundwater. Attempts to prevent damage and alleviate problems from blasting have been initiated by the federal and state governments by the promulgation of rules and regulations to prevent against vagrant and negligent blasting procedures. The Office of Surface Mining, Reclamation and Enforcement (OSMRE) provided regulations in the Federal Register on March 8, 1983, with particular reference to surface mining practices. Most of the states have adopted the OSMRE guidelines to enforce these rules and regulations.

Simpson, Thomas A.

1989-03-01

122

Monitoring the setting of concrete containing blast-furnace slag by measuring the ultrasonic p-wave velocity  

Microsoft Academic Search

Ultrasonic transmission measurements allow the continuous monitoring of the setting of both mortar and concrete samples, which is important to determine for instance the formwork removal time. However, aspects such as the cause of the low initial velocity, the relation between the velocity and the setting times and the effect of cement type or cement replacing additives are still under

Nicolas Robeyst; Elke Gruyaert; Christian U. Grosse; Nele De Belie

2008-01-01

123

Data Analysis Measurement: Having a Solar Blast! NASA Connect: Program 7 in the 2001-2002 Video Series. [Videotape].  

ERIC Educational Resources Information Center

NASA Connect is an interdisciplinary, instructional distance learning program targeting students in grades 6-8. This videotape explains how engineers and researchers at the National Aeronautics and Space Administration (NASA) use data analysis and measurement to predict solar storms, anticipate how they will affect the Earth, and improve…

National Aeronautics and Space Administration, Hampton, VA. Langley Research Center.

124

Significance of blast wave studies to propulsion.  

NASA Technical Reports Server (NTRS)

Brief survey of experimental methods currently used for the study of blast wave phenomena with emphasis on high rate exothermic processes. The experimental techniques have used such devices as divergent test sections in shock or detonation tubes, employment of proper test gases, as in marginal detonations, and a variety of explosion systems from finite source explosion apparatus to devices where virtually point explosions are obtained by local breakdown initiated by means of focused laser irradiation. Other methods used are detonation tubes where pressure waves are generated by accelerating flames or by exothermic reactions developed behind reflected shocks, as well as a variety of converging shock and implosion vessels.

Oppenheim, A. K.

1971-01-01

125

A comparative study of buried structure in soil subjected to blast load using 2D and 3D numerical simulations  

Microsoft Academic Search

The response of underground structures subjected to subsurface blast is an important topic in protective engineering. Due to various constraints, pertinent experimental data are extremely scarce. Adequately detailed numerical simulation thus becomes a desirable alternative. However, the physical processes involved in the explosion and blast wave propagation are very complex, hence a realistic and detailed reproduction of the phenomena would

Yong Lu; Zhongqi Wang; Karen Chong

2005-01-01

126

External Resource: Having a Solar Blast  

NSDL National Science Digital Library

In Data Analysis and Measurement: Having a Solar Blast!, students will learn how NASA researchers study the Sun. They will learn how satellite technology plays a pivotal role in helping NASA researchers understand the Sun-Earth connection. Students will l

1900-01-01

127

Modeling of Near-Field Blast Performance.  

National Technical Information Service (NTIS)

Two hydrocode packages, ALE3D and CTH, were used to model the blast from a 450-g sphere of the near-ideal explosive composition 4. The pressure profile was optically measured using high-speed video and streak camera imaging techniques. Pressure profiles w...

B. E. Homan K. L. McNesby M. M. Biss

2013-01-01

128

Experimental modeling of explosive blast-related traumatic brain injuries.  

PubMed

This study aims to characterize the interaction of explosive blast waves through simulated anatomical systems. We have developed physical models and a systematic approach for testing traumatic brain injury (TBI) mechanisms and occurrences. A simplified series of models consisting of spherical poly(methyl methacrylate) (PMMA) shells housing synthetic gelatins as brain simulants have been utilized. A series of experiments was conducted to compare the sensitivity of the system response to mechanical properties of the simulants under high strain-rate explosive blasts. Small explosive charges were directed at the models to produce a realistic blast wave in a scaled laboratory setting. Blast profiles were measured and analyzed to compare system response severity. High-speed shadowgraph imaging captured blast wave interaction with the head model while particle tracking captured internal response for displacement and strain correlation. The results suggest amplification of shock waves inside the head near material interfaces due to impedance mismatches. In addition, significant relative displacement was observed between the interacting materials suggesting large strain values of nearly 5%. Further quantitative results were obtained through shadowgraph imaging of the blasts confirming a separation of time scales between blast interaction and bulk movement. These results lead to a conclusion that primary blast effects may potentially contribute significantly to the occurrence of military associated TBI. PMID:20580931

Alley, Matthew D; Schimizze, Benjamin R; Son, Steven F

2011-01-01

129

Blast Loading Experiments of Surrogate Models for Tbi Scenarios  

NASA Astrophysics Data System (ADS)

This study aims to characterize the interaction of explosive blast waves through simulated anatomical models. We have developed physical models and a systematic approach for testing traumatic brain injury (TBI) mechanisms and occurrences. A simplified series of models consisting of spherical PMMA shells housing synthetic gelatins as brain simulants have been utilized. A series of experiments was conducted to compare the sensitivity of the system response to mechanical properties of the simulants under high strain-rate explosive blasts. Small explosive charges were directed at the models to produce a realistic blast wave in a scaled laboratory test cell setting. Blast profiles were measured and analyzed to compare system response severity. High-speed shadowgraph imaging captured blast wave interaction with the head model while particle tracking captured internal response for displacement and strain correlation. The results suggest amplification of shock waves inside the head near material interfaces due to impedance mismatches. In addition, significant relative displacement was observed between the interacting materials suggesting large strain values of nearly 5%. Further quantitative results were obtained through shadowgraph imaging of the blasts confirming a separation of time scales between blast interaction and bulk movement. These results lead to the conclusion that primary blast effects could cause TBI occurrences.

Alley, M. D.; Son, S. F.

2009-12-01

130

Interferometric CT measurement of three-dimensional flow phenomena on shock waves and vortices discharged from open ends  

Microsoft Academic Search

Three-dimensional flow phenomena are observed in a shock tube experiment for shock waves and vortices discharged from a square open end and a pair of circular open ends by using an interferometric CT (Computed Tomography) technique. To take multidirectional finite-fringe interferograms for a three-dimensional flow field, we introduce a rotating duct model in the test section of the shock tube.

H. Honma; M. Ishihara; T. Yoshimura; K. Maeno; T. Morioka

2003-01-01

131

Expanded rock blast modeling capabilities of DMC{_}BLAST, including buffer blasting  

SciTech Connect

A discrete element computer program named DMC{_}BLAST (Distinct Motion Code) has been under development since 1987 for modeling rock blasting. This program employs explicit time integration and uses spherical or cylindrical elements that are represented as circles in 2-D. DMC{_}BLAST calculations compare favorably with data from actual bench blasts. The blast modeling capabilities of DMC{_}BLAST have been expanded to include independently dipping geologic layers, top surface, bottom surface and pit floor. The pit can also now be defined using coordinates based on the toe of the bench. A method for modeling decked explosives has been developed which allows accurate treatment of the inert materials (stemming) in the explosive column and approximate treatment of different explosives in the same blasthole. A DMC{_}BLAST user can specify decking through a specific geologic layer with either inert material or a different explosive. Another new feature of DMC{_}BLAST is specification of an uplift angle which is the angle between the normal to the blasthole and a vector defining the direction of explosive loading on particles adjacent to the blasthole. A buffer (choke) blast capability has been added for situations where previously blasted material is adjacent to the free face of the bench preventing any significant lateral motion during the blast.

Preece, D.S. [Sandia National Labs., Albuquerque, NM (United States); Tidman, J.P.; Chung, S.H. [ICI Explosives (Canada)

1996-12-31

132

Compound 49b protects against blast-induced retinal injury  

PubMed Central

Aim To determine whether Compound 49b, a novel beta-adrenergic receptor agonist, can prevent increased inflammation and apoptosis in mice after exposure to ocular blast. Methods Eyes of C57/BL6 mice were exposed to a blast of air from a paintball gun at 26 psi (?0.18 MPa). Eyes were collected 4 hours, 24 hours, and 72 hours after blast exposure. In a subset of mice, Compound 49b eyedrops (1 mM) were applied within 4 hours, 24 hours, or 72 hours of the blast. Three days after blast exposure, all mice were sacrificed. One eye was used to measure levels of retinal proteins (TNF?, IL-1?, Bax, BcL-xL, caspase 3, and cytochrome C). The other eye was used for TUNEL labeling of apoptotic cells, which were co-labeled with NeuN to stain for retinal ganglion cells. Results We found that ocular exposure to 26 psi air pressure led to a significant increase in levels of apoptotic and inflammatory mediators within 4 hours, which lasted throughout the period investigated. When Compound 49b was applied within 4 hours or 24 hours of blast injury, levels of apoptotic and inflammatory mediators were significantly reduced. Application of Compound 49b within 72 hours of blast injury reduced levels of inflammatory mediators, but not to untreated levels. Conclusions Ocular blast injury produces a significant increase in levels of key inflammatory and apoptotic markers in the retina as early as 4 hours after blast exposure. These levels are significantly reduced if a beta-adrenergic receptor agonist is applied within 24 hours of blast exposure. Data suggest that local application of beta-adrenergic receptor agonists may be beneficial to reduce inflammation and apoptosis.

2013-01-01

133

Performance of blasting caps  

NASA Technical Reports Server (NTRS)

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.

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

1993-01-01

134

COMPARATIVE PULMONARY TOXICITY OF BLASTING SAND AND FIVE SUBSTITUTE ABRASIVE BLASTING AGENTS  

Microsoft Academic Search

Blasting sand is used for abrasive blasting, but its inhalation is associated with pulmonary inflammation and fibrosis. Consequently, safer substitute materials for blasting sand are needed. In a previous study from this laboratory, the comparative pulmonary toxicity of five abrasive blasting substitutes and blasting sand was reported. In this study, the pulmonary toxicity of blasting sand was compared to five

Dale W. Porter; Ann F. Hubbs; Victor A. Robinson; Lori A. Battelli; Mark Greskevitch; Mark Barger; Douglas Landsittel; William Jones; Vincent Castranova

2002-01-01

135

Programmable Grit-Blasting System  

NASA Technical Reports Server (NTRS)

In programmable grit-blasting system undergoing design, controller moves blasting head to precise positions to shape or remove welding defects from parts. Controller holds head in position for preset dwell time and moves head to new position along predetermined path. Position of articulated head established by pair of servomotors according to programmed signals from controller. Head similar to video borescope. Used to remove welding defects in blind holes. Suited for repetitive production operations in grit-blast box.

Burley, Richard K.

1988-01-01

136

Micro-blast waves using detonation transmission tubing  

NASA Astrophysics Data System (ADS)

Micro-blast waves emerging from the open end of a detonation transmission tube were experimentally visualized in this study. A commercially available detonation transmission tube was used (Nonel tube, M/s Dyno Nobel, Sweden), which is a small diameter tube coated with a thin layer of explosive mixture (HMX + traces of Al) on its inner side. The typical explosive loading for this tube is of the order of 18 mg/m of tube length. The blast wave was visualized using a high speed digital camera (frame rate 1 MHz) to acquire time-resolved schlieren images of the resulting flow field. The visualization studies were complemented by computational fluid dynamic simulations. An analysis of the schlieren images showed that although the blast wave appears to be spherical, it propagates faster along the tube axis than along a direction perpendicular to the tube axis. Additionally, CFD analysis revealed the presence of a barrel shock and Mach disc, showing structures that are typical of an underexpanded jet. A theory in use for centered large-scale explosions of intermediate strength (10 < ? {p}/{p}_0 ? 0.02) gave good agreement with the blast trajectory along the tube axis. The energy of these micro-blast waves was found to be 1.25 ± 0.94 J and the average TNT equivalent was found to be 0.3. The repeatability in generating these micro-blast waves using the Nonel tube was very good (± 2 %) and this opens up the possibility of using this device for studying some of the phenomena associated with muzzle blasts in the near future.

Samuelraj, I. Obed; Jagadeesh, G.; Kontis, K.

2013-07-01

137

Blast furnace injection symposium: Proceedings  

SciTech Connect

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.

NONE

1996-12-31

138

HIGH PRODUCTIVITY VACUUM BLASTING SYSTEM  

SciTech Connect

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.

Dr. M.A. Ebadian

2000-01-13

139

Propagation of Nonideal Blast Waves.  

National Technical Information Service (NTIS)

The propagation of non-ideal blast waves initiated by finite power density sources has been classified into three regimes. The early-time motion of a non-ideal blast reflects the characteristics of the energy-time profile of the particular initiation ener...

C. M. Guirao G. G. Bach J. H. Lee

1974-01-01

140

Blast load assessment using hydrocodes  

Microsoft Academic Search

The evaluation of pressures and impulses produced by blast loads with the aid of hydrocodes is studied in this paper. Numerical results are compared with those obtained with existing analytical expressions for different scaled distances and boundary conditions. In particular, the capacity of both methods to capture multiple reflections of the blast load is analyzed. The effects of mesh size

B. Luccioni; D. Ambrosini; R. Danesi

2006-01-01

141

Spectroscopic diagnostics in a colliding-blast-wave experiment  

Microsoft Academic Search

Visible spectral lines from [ital n]=3, [Delta][ital n]=0 transitions in N[sup +] and N[sup 2+] ions are used for measuring the plasma electron density and temperature in a region of two colliding blast waves, propagating through a 1.5--10-Torr nitrogen atmosphere. The blast waves originate at the tips of two aluminum rods irradiated with two beams of the Naval Research Laboratory

R. C. Elton; D.-M. Billings; C. K. Manka; H. R. Griem; J. Grun; B. H. Ripin; J. Resnick

1994-01-01

142

Neural networks for the identification and control of blast furnace hot metal quality  

Microsoft Academic Search

The operation and control of blast furnaces poses a great challenge because of the difficult measurement and control problems associated with the unit. The measurement of hot metal composition with respect to silica and sulfur are critical to the economic operation of blast furnaces. The measurement of the compositions require spectrographic techniques which can be performed only off line. An

V. R Radhakrishnan; A. R Mohamed

2000-01-01

143

Reactive Blast Waves from Composite Charges  

Microsoft Academic Search

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 = 0.604 g\\/cc. The Al powder acts as a fuel but does

A L Kuhl; J B Bell; V E Beckner

2009-01-01

144

HIGH PRODUCTIVITY VACUUM BLASTING SYSTEM  

SciTech Connect

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 construct a pre-prototype of the nozzle, blast head with wind curtain, sensors, and dust separator and test this system to assess the performance of the new design under controlled conditions at the contractor's facility. In phase III, the Contractor shall design and construct a prototype of the High Productivity Vacuum Blasting System, based on the results of the pre-prototype design and testing performed. This unit will be a full-scale prototype and will be tested at a designated Department of Energy (DOE) facility. Based on the results, the system performance, the productivity, and the economy of the improved vacuum blasting system will be evaluated.

William S. McPhee

1999-05-31

145

Continuum modeling of a neuronal cell under blast loading.  

PubMed

Traumatic brain injuries have recently been put under the spotlight as one of the most important causes of accidental brain dysfunctions. Significant experimental and modeling efforts are thus underway to study the associated biological, mechanical and physical mechanisms. In the field of cell mechanics, progress is also being made at the experimental and modeling levels to better characterize many of the cell functions, including differentiation, growth, migration and death. The work presented here aims to bridge both efforts by proposing a continuum model of a neuronal cell submitted to blast loading. In this approach, the cytoplasm, nucleus and membrane (plus cortex) are differentiated in a representative cell geometry, and different suitable material constitutive models are chosen for each one. The material parameters are calibrated against published experimental work on cell nanoindentation at multiple rates. The final cell model is ultimately subjected to blast loading within a complete computational framework of fluid-structure interaction. The results are compared to the nanoindentation simulation, and the specific effects of the blast wave on the pressure and shear levels at the interfaces are identified. As a conclusion, the presented model successfully captures some of the intrinsic intracellular phenomena occurring during the cellular deformation under blast loading that potentially lead to cell damage. It suggests, more particularly, that the localization of damage at the nucleus membrane is similar to what has already been observed at the overall cell membrane. This degree of damage is additionally predicted to be worsened by a longer blast positive phase duration. In conclusion, the proposed model ultimately provides a new three-dimensional computational tool to evaluate intracellular damage during blast loading. PMID:22562014

Jérusalem, Antoine; Dao, Ming

2012-09-01

146

Critical distance for blast-resistant design  

Microsoft Academic Search

Blast loads have, in the recent past, become important service loads for certain categories of structures. An important task in blast-resistant design is to make a realistic prediction of the blast pressures. The distance of explosion from the structure is an important datum, governing the magnitude and duration of the blast loads. The current practice is to choose some arbitrary

M. V. Dharaneepathy; M. N. Keshava Rao; A. R. Santhakumar

1995-01-01

147

Modeling Coal Seam Damage in Cast Blasting  

Microsoft Academic Search

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

S. H. Chung; D. S. Preece

1998-01-01

148

Neurological effects of blast injury.  

PubMed

Over the last few years, thousands of soldiers and an even greater number of civilians have suffered traumatic injuries due to blast exposure, largely attributed to improvised explosive devices in terrorist and insurgent activities. The use of body armor is allowing soldiers to survive blasts that would otherwise be fatal due to systemic damage. Emerging evidence suggests that exposure to a blast can produce neurologic consequences in the brain but much remains unknown. To elucidate the current scientific basis for understanding blast-induced traumatic brain injury (bTBI), the NIH convened a workshop in April 2008. A multidisciplinary group of neuroscientists, engineers, and clinicians were invited to share insights on bTBI, specifically pertaining to: physics of blast explosions, acute clinical observations and treatments, preclinical and computational models, and lessons from the international community on civilian exposures. This report provides an overview of the state of scientific knowledge of bTBI, drawing from the published literature, as well as presentations, discussions, and recommendations from the workshop. One of the major recommendations from the workshop was the need to characterize the effects of blast exposure on clinical neuropathology. Clearer understanding of the human neuropathology would enable validation of preclinical and computational models, which are attempting to simulate blast wave interactions with the central nervous system. Furthermore, the civilian experience with bTBI suggests that polytrauma models incorporating both brain and lung injuries may be more relevant to the study of civilian countermeasures than considering models with a neurologic focus alone. PMID:20453776

Hicks, Ramona R; Fertig, Stephanie J; Desrocher, Rebecca E; Koroshetz, Walter J; Pancrazio, Joseph J

2010-05-01

149

Neurological Effects of Blast Injury  

PubMed Central

Over the last few years, thousands of soldiers and an even greater number of civilians have suffered traumatic injuries due to blast exposure, largely attributed to improvised explosive devices in terrorist and insurgent activities. The use of body armor is allowing soldiers to survive blasts that would otherwise be fatal due to systemic damage. Emerging evidence suggests that exposure to a blast can produce neurological consequences in the brain, but much remains unknown. To elucidate the current scientific basis for understanding blast-induced traumatic brain injury (bTBI), the NIH convened a workshop in April, 2008. A multidisciplinary group of neuroscientists, engineers, and clinicians were invited to share insights on bTBI, specifically pertaining to: physics of blast explosions, acute clinical observations and treatments, preclinical and computational models, and lessons from the international community on civilian exposures. This report provides an overview of the state of scientific knowledge of bTBI, drawing from the published literature, as well as presentations, discussions, and recommendations from the workshop. One of the major recommendations from the workshop was the need to characterize the effects of blast exposure on clinical neuropathology. Clearer understanding of the human neuropathology would enable validation of preclinical and computational models, which are attempting to simulate blast wave interactions with the central nervous system. Furthermore, the civilian experience with bTBI suggests that polytrauma models incorporating both brain and lung injuries may be more relevant to the study of civilian countermeasures than considering models with a neurological focus alone.

Hicks, Ramona R.; Fertig, Stephanie J.; Desrocher, Rebecca E.; Koroshetz, Walter J.; Pancrazio, Joseph J.

2010-01-01

150

Blast From the Past  

NSDL National Science Digital Library

A recently recovered deep-sea core supports theories that an asteroid collided with the earth 65 million years ago, around the time of the extinction of the dinosaurs. The Smithsonian Institution National Museum of Natural History's new site, Blast from the Past, contains details on this cataclysmic event. Colorful graphics provide conceptual illustrations of the asteroid impact and aftermath, accompanied by photographs of the deep-sea core. Text summaries, followed by bibliographic references, describe the asteroid hypothesis, the Cretaceous/Tertiary (K/T) boundary, and the utility of deep-sea cores. With links to other paleobiological sites and related museum exhibits, this site is a useful resource for those wanting to know more about fateful asteroid impacts.

151

Computational Fluid Dynamics (CFD) Modeling for High Rate Pulverized Coal Injection (PCI) into the Blast Furnace  

SciTech Connect

Pulverized coal injection (PCI) into the blast furnace (BF) has been recognized as an effective way to decrease the coke and total energy consumption along with minimization of environmental impacts. However, increasing the amount of coal injected into the BF is currently limited by the lack of knowledge of some issues related to the process. It is therefore important to understand the complex physical and chemical phenomena in the PCI process. Due to the difficulty in attaining trus BF measurements, Computational fluid dynamics (CFD) modeling has been identified as a useful technology to provide such knowledge. CFD simulation is powerful for providing detailed information on flow properties and performing parametric studies for process design and optimization. In this project, comprehensive 3-D CFD models have been developed to simulate the PCI process under actual furnace conditions. These models provide raceway size and flow property distributions. The results have provided guidance for optimizing the PCI process.

Dr. Chenn Zhou

2008-10-15

152

Toxicology of blast overpressure.  

PubMed

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

Elsayed, N M

1997-07-25

153

NCBI BLAST: a better web interface  

Microsoft Academic Search

Basic Local Alignment Search Tool (BLAST) is a sequence similarity search program. The public interface of BLAST, http:\\/\\/www.ncbi.nlm.nih.gov\\/ blast, at the NCBI website has recently been reengineered to improve usability and performance. Key new features include simplified search forms, improved navigation, a list of recent BLAST results, saved search strategies and a documentation directory. Here, we describe the BLAST web

Mark Johnson; Irena Zaretskaya; Yan Raytselis; Yuri Merezhuk; Scott Mcginnis; Thomas L. Madden

2008-01-01

154

Characterization of viscoelastic materials for low-magnitude blast mitigation  

NASA Astrophysics Data System (ADS)

Recent research indicates that exposure to low amplitude blast waves, such as IED detonation or multiple firings of a weapon, causes damage to brain tissue resulting in Traumatic Brain Injury (TBI) and Post Traumatic Stress Disorder (PTSD). Current combat helmets are not sufficiently protecting warfighters from this danger and the effects are debilitating, costly, and long-lasting. The objective of the present work is to evaluate the blast mitigating behavior of current helmet materials and new materials designed for blast mitigation using a test fixture recently developed at the Naval Surface Warfare Center Dahlgren Division for use with an existing gas gun. The 40-mm-bore gas gun was used as a shock tube to generate blast waves (ranging from 0.5 to 2 bar) in the test fixture mounted on the gun muzzle. A fast opening valve was used to release helium gas from the breech which formed into a blast wave and impacted instrumented targets in the test fixture. Blast attenuation of selected materials was determined through the measurement of stress data in front of and behind the target. Materials evaluated in this research include polyurethane foam from currently fielded US Army and Marine Corps helmets, polyurea 1000, and three hardnesses of Sorbothane (48, 58, and 70 durometer, Shore 00). Polyurea 1000 and 6061-T6 aluminum were used to calibrate the stress gauges.

Bartyczak, S.; Mock, W.

2014-05-01

155

Investigation of blast-induced traumatic brain injury  

PubMed Central

Objective Many troops deployed in Iraq and Afghanistan have sustained blast-related, closed-head injuries from being within non-lethal distance of detonated explosive devices. Little is known, however, about the mechanisms associated with blast exposure that give rise to traumatic brain injury (TBI). This study attempts to identify the precise conditions of focused stress wave energy within the brain, resulting from blast exposure, which will correlate with a threshold for persistent brain injury. Methods This study developed and validated a set of modelling tools to simulate blast loading to the human head. Using these tools, the blast-induced, early-time intracranial wave motions that lead to focal brain damage were simulated. Results The simulations predict the deposition of three distinct wave energy components, two of which can be related to injury-inducing mechanisms, namely cavitation and shear. Furthermore, the results suggest that the spatial distributions of these damaging energy components are independent of blast direction. Conclusions The predictions reported herein will simplify efforts to correlate simulation predictions with clinical measures of TBI and aid in the development of protective headwear.

Ludwigsen, John S.; Ford, Corey C.

2014-01-01

156

Review of equatorial scintillation phenomena in light of recent developments in the theory and measurement of equatorial irregularities  

Microsoft Academic Search

Recent developments in the understanding of equatorial irregularities have come from a unique combination of rocket, satellite, radar, theoretical, and computer simulation investigations. These will be reviewed with emphasis on the effect of the irregularities upon the propagation of radio waves. Recent scintillation calculations based upon in situ rocket and satellite irregularity measurements are also reviewed and a new composite

S. Basu; M. C. Kelley

1977-01-01

157

TOPICAL REVIEW: Low-frequency noise measurements as a characterization tool for degradation phenomena in solid-state devices  

Microsoft Academic Search

The analysis of the degradation mechanisms that affect solid-state devices represents a key factor in the era of VLSI technology. This paper presents an overview of how the low-frequency noise measurement (LFNM) technique has been applied to the study of the most frequent causes of failure in integrated circuits and discrete components. After discussing noise and fluctuations in electron devices,

C. Ciofi; B. Neri

2000-01-01

158

Computer systems for controlling blast furnace operations at Rautaruukki  

SciTech Connect

Energy accounts for a significant portion of the total blast furnace production costs and, to minimize energy consumption, both technical and economical aspects have to be considered. Thus, considerable attention has been paid to blast furnace energy consumption and productivity. The most recent furnace relines were in 1985 and 1986. At that time, the furnaces were modernized and instrumentation was increased. After the relines, operation control and monitoring of the process is done by a basic automation systems (DCS`s and PLC`s) and a supervision system (process computer). The supervision system is the core of the control system combining reports, special displays, trends and mathematical models describing in-furnace phenomena. Low energy consumption together with high productivity and stable blast furnace operation have been achieved due to an improvement in raw materials quality and implementation of automation and computer systems to control blast furnace operation. Currently, the fuel rate is low and productivity is in excess of 3.0 tonnes/cu meter/day, which is one of the highest values achieved anywhere for long-term operation.

Inkala, P.; Karppinen, A. [Rautaruukki Oy, Raahe (Finland); Seppanen, M. [Rautaruukki Oy Engineering, Oulu (Finland)

1995-08-01

159

Numerical analysis for the multi-phase flow of pulverized coal injection inside blast furnace tuyere  

SciTech Connect

The pulverized coal injection (PCI) system was modified from single lance injection into double lance injection at No. 3 Blast Furnace of CSC. It is beneficial to reduce the cost of coke. However, the injected coal was found very close to the inner wall of the tuyere during the operation, such as to cause the possibility of erosion for the tuyere. In this study a three-dimensional mathematical model has been developed based on a computational fluid dynamics software PHOENICS to simulate the fluid flow phenomena inside blast furnace tuyere. The model was capable of handling steady-state, three-dimensional multi-phase flow of pulverized coal injection. The model was applied to simulate the flow patterns of the injection coal inside the tuyere with two kinds of lance design for the PCI system. The distribution of injection coal was simulated such as to estimate the possibility of erosion for the tuyere. The calculated results agreed with the operating experience of CSC plant and the optimum design of double lance was suggested. The model was also applied to simulate the oxygen concentration distribution with these different oxygen enrichments for the coal/oxygen lance system. The calculated results agreed with the experimental measurement. These test results demonstrate that the model is both reasonably reliable and efficient.

Chen, C.W. [Diwan College of Management, Tainan (Taiwan)

2005-09-01

160

Blast from explosive evaporation of carbon dioxide: experiment, modeling and physics  

NASA Astrophysics Data System (ADS)

Explosive evaporation of a superheated liquid is a relevant hazard in the process industry. A vessel rupture during storage, transport or handling may lead to devastating blast effects. In order to assess the risk associated with this hazard or to design protective measures, an accurate prediction model for the blast generated after vessel rupture is needed. For this reason a fundamental understanding of the effects of a boiling liquid expanding vapor explosion (BLEVE) is essential. In this paper, we report on a number of well-defined BLEVE experiments with 40-l liquid CO2 bottles. The existing inertia-limited BLEVE model has been validated by its application to these experiments. Good qualitative agreement between model and experiment was found, while quantitatively the results provide a safe estimate. Possible model improvements taking into account the finite rate of evaporation are described. These comprise phenomena such as bubble nucleation and growth rate, and the two-phase flow regime. Suggestions for improved experiments are given as well.

van der Voort, M. M.; van den Berg, A. C.; Roekaerts, D. J. E. M.; Xie, M.; de Bruijn, P. C. J.

2012-03-01

161

Portable convertible blast effects shield  

DOEpatents

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.

Pastrnak, John W. (Livermore, CA); Hollaway, Rocky (Modesto, CA); Henning, Carl D. (Livermore, CA); Deteresa, Steve (Livermore, CA); Grundler, Walter (Hayward, CA); Hagler,; Lisle B. (Berkeley, CA); Kokko, Edwin (Dublin, CA); Switzer, Vernon A (Livermore, CA)

2010-10-26

162

Portable convertible blast effects shield  

DOEpatents

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.

Pastrnak, John W. (Livermore, CA); Hollaway, Rocky (Modesto, CA); Henning, Carl D. (Livermore, CA); Deteresa, Steve (Livermore, CA); Grundler, Walter (Hayward, CA); Hagler, Lisle B. (Berkeley, CA); Kokko, Edwin (Dublin, CA); Switzer, Vernon A (Livermore, CA)

2007-05-22

163

Portable convertible blast effects shield  

DOEpatents

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.

Pastrnak, John W. (Livermore, CA); Hollaway, Rocky (Modesto, CA); Henning, Carl D. (Livermore, CA); Deteresa, Steve (Livermore, CA); Grundler, Walter (Hayward, CA); Hagler, Lisle B. (Berkeley, CA); Kokko, Edwin (Dublin, CA); Switzer, Vernon A. (Livermore, CA)

2011-03-15

164

Blasting, graphical interfaces and Unix.  

National Technical Information Service (NTIS)

A discrete element computer program, DMC (Distinct Motion Code) was developed to simulate blast-induced rock motion. To simplify the complex task of entering material and explosive design parameters as well as bench configuration, a full-featured graphica...

S. Knudsen D. S. Preece

1993-01-01

165

Determination of explosive blast loading equivalencies with an explosively driven shock tube  

SciTech Connect

Recently there has been significant interest in evaluating the potential of many different non-ideal energetic materials to cause blast damage. We present a method intended to quantitatively compare the blast loading generated by different energetic materials through use of an explosively driven shock tube. The test explosive is placed at the closed breech end of the tube and initiated with a booster charge. The resulting shock waves are then contained and focused by the tube walls to form a quasi-one-dimensional blast wave. Pressure transducers along the tube wall measure the blast overpressure versus distance from the source and allow the use of the one-dimensional blast scaling relationship to determine the energy deposited into the blast wave per unit mass of test explosive. These values are then compared for different explosives of interest and to other methods of equivalency determination.

Jackson, Scott I [Los Alamos National Laboratory; Hill, Larry G [Los Alamos National Laboratory; Morris, John S [Los Alamos National Laboratory

2009-01-01

166

Pseudo-schlieren CT measurement of three-dimensional flow phenomena on shock waves and vortices discharged from open ends  

Microsoft Academic Search

1A pseudo-schlieren technique is applied to the interferometric computed tomography (CT) measurement of three-dimensional (3-D) shock waves discharged from a square open end and a pair of circular open ends in a shock tube experiment. The experiment is performed for incident shock Mach numbers of 2.0 and 2.2 in nitrogen gas under supersonic post shock flow conditions at the open

K. Maeno; T. Kaneta; T. Morioka; H. Honma

2005-01-01

167

Water blasting paint removal methods  

NASA Astrophysics Data System (ADS)

Water blasting is a paint removal technique that has been used for cleaning and paint removal for many years. The major disadvantages until recently were the slow rate of paint removal and the possibility of damage to the substrate from the high pressures used. With the improvement in nozzle design that allows for higher operating pressures and the use of environmentally compliant paint softeners or strippers, water blasting is becoming a recognized technique for paint removal in the aircraft industry.

Foster, Terry

1995-04-01

168

Trapping phenomena in AlGaN/GaN HEMTs: a study based on pulsed and transient measurements  

NASA Astrophysics Data System (ADS)

Slow trapping phenomenon in AlGaN/GaN HEMTs has been extensively analyzed and described in this paper. Thanks to a detailed investigation, based on a combined pulsed and transient investigation of the current/voltage characteristics (carried out over on an 8-decade time scale), we report a detailed description of the properties of trap levels located in the gate-drain surface, and in the region under the gate of AlGaN/GaN HEMTs. More specifically, the following, relevant results have been identified: (i) the presence of surface trap states may determine a significant current collapse, and reduction of the peak transconductance. During a current transient measurement, the emission of electrons trapped at surface states proceeds through hopping, as demonstrated by means of temperature-dependent measurements. The activation energy of the de-trapping process is equal to 99 meV. (ii) The presence of a high density of defects under the gate may induce a significant shift in the threshold voltage, when devices are submitted to pulsed transconductance measurements. The traps responsible for this process have an activation energy of 0.63 eV, and are detected only on samples with high gate leakage, since gate current allows for a more effective charging/de-charging of the defects.

Meneghesso, Gaudenzio; Meneghini, Matteo; Bisi, Davide; Rossetto, Isabella; Cester, Andrea; Mishra, Umesh K.; Zanoni, Enrico

2013-07-01

169

Rate-sensitive numerical analysis of dynamic responses of arched blast doors subjected to blast loading  

Microsoft Academic Search

Current practice in analysis and design of blast doors subjected to blast loading considers only simple boundary conditions\\u000a and material properties. The boundary conditions and material properties, in fact, have considerable influence on the response\\u000a of blast doors subjected to blast loading. In this paper, the dynamic responses of a reinforced concrete arched blast door\\u000a under blast loading were analyzed

Li Chen; Qin Fang; Yi Zhang; Yadong Zhang

2008-01-01

170

Manual for the prediction of blast and fragment loadings on structures  

SciTech Connect

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.

Not Available

1980-11-01

171

Carbon deposition on blast furnace raw mateials  

SciTech Connect

This study was undertaken to investigate the effects of various raw materials on the rate and amount of carbon deposition in the blast furnace. The isothermal deposition rate and the total carbon deposited in a simulated stack descent were measured for two lime-fluxed pellets, two dolomite-fluxed pellets, two pellets made from magnetite concentrates, one from hematite concentrate, two sinters, and an earthy hematite lump ore. The increasing carbon deposition rate with time, as the iron oxide substrate is reduced, is a powerful indication that metallic iron is the necessary catalyst for the carbon deposition reaction. Carbon deposits only on the exterior of the pellet, so carbon deposition does not depend on the internal structure of the pellet. The internal bonding in the pellet has no effect also. The study of the bulk chemical analysis of SiO/sub 2/ in the pellets to the rate of carbon deposition was given; also the correlation of the lime to magnesia ratio of the bulk chemical analysis to the total carbon deposited in the blast furnace simulation tests was included. There seemed to be a relationship between the isothermal rates of carbon deposition and the amount of carbon deposited in the blast furnace simulation. The 550/sup 0/C and 650/sup 0/C range will be the significant region when considering carbon deposition for the purpose of modeling the blast furnace, and the total amount deposited will depend on the time that a pellet spends between these two temperatures. 12 figures, 3 tables. (DP)

Geiger, G.H.; Lowry, M.L.

1981-01-01

172

Implementation of the exploding wire technique to study blast-wave-structure interaction  

NASA Astrophysics Data System (ADS)

The effort invested in improving our understanding of the physics of high-energy explosion events has been steadily increasing since the latter part of the twentieth century. Moreover, the dramatic increase in computer power over the last two decades has made the numerical simulation approach the dominant tool for investigating blast phenomena and their effects. However, field tests, on both large and small scales, are still in use. In the current paper, we present an experimental tool to better resolve and study the blast-structure interaction phenomenon and to help validate the numerical simulations of the same. The experimental tool uses an exploding wire technique to generate small-scale cylindrical and spherical blast waves. This approach permits safe operation, high repeatability, and the use of advanced diagnostic systems. The system was calibrated using an analytical model, an empirical model, and numerical simulation. To insure that spherical blast geometry was achieved, a set of free air blast experiments was done in which high-speed photography was used to monitor the blast structure. A scenario in which an explosion occurred in the vicinity of a structure demonstrated the system's capabilities. Using this simple but not trivial configuration showed unequivocally the effectiveness of this tool. From this comparison, it was found that at early times of blast-structure interaction, the agreement between the two sets of results was very good, but at later times incongruences appeared. Effort has been made to interpret this observation. Furthermore, by using similitude analysis, the results obtained from the small-scale experiments can be applied to the full-scale problem. We have shown that an exploding wire system offers an inexpensive, safe, easy to operate, and effective tool for studying phenomena related to blast-wave-structure interactions.

Ram, O.; Sadot, O.

2012-11-01

173

Quantifying transient 3D dynamical phenomena of single mRNA particles in live yeast cell measurements.  

PubMed

Single-particle tracking (SPT) has been extensively used to obtain information about diffusion and directed motion in a wide range of biological applications. Recently, new methods have appeared for obtaining precise (10s of nm) spatial information in three dimensions (3D) with high temporal resolution (measurements obtained every 4 ms), which promise to more accurately sense the true dynamical behavior in the natural 3D cellular environment. Despite the quantitative 3D tracking information, the range of mathematical methods for extracting information about the underlying system has been limited mostly to mean-squared displacement analysis and other techniques not accounting for complex 3D kinetic interactions. There is a great need for new analysis tools aiming to more fully extract the biological information content from in vivo SPT measurements. High-resolution SPT experimental data has enormous potential to objectively scrutinize various proposed mechanistic schemes arising from theoretical biophysics and cell biology. At the same time, methods for rigorously checking the statistical consistency of both model assumptions and estimated parameters against observed experimental data (i.e., goodness-of-fit tests) have not received great attention. We demonstrate methods enabling (1) estimation of the parameters of 3D stochastic differential equation (SDE) models of the underlying dynamics given only one trajectory; and (2) construction of hypothesis tests checking the consistency of the fitted model with the observed trajectory so that extracted parameters are not overinterpreted (the tools are applicable to linear or nonlinear SDEs calibrated from nonstationary time series data). The approach is demonstrated on high-resolution 3D trajectories of single ARG3 mRNA particles in yeast cells in order to show the power of the methods in detecting signatures of transient directed transport. The methods presented are generally relevant to a wide variety of 2D and 3D SPT tracking applications. PMID:24015725

Calderon, Christopher P; Thompson, Michael A; Casolari, Jason M; Paffenroth, Randy C; Moerner, W E

2013-12-12

174

Quantifying Momentum Transfer Due to Blast Waves from Oxy-Acetylene Driven Shock Tubes.  

National Technical Information Service (NTIS)

Shock tubes have been widely used since the 1950s to study physical phenomena such as shock waves, combustion chemistry, and the response of materiel to blast loading. Recently, laboratory-scale shock tubes driven by oxy- acetylene were described. It was ...

A. Courtney H. Her M. Courtney

2012-01-01

175

Blasting Rocks and Blasting Cars Applied Engineering  

ScienceCinema

June 30, 2004 Berkeley Lab lecture: Deb Hopkins works with industries like automobile, mining and paper to improve their evaluation and measuring techniques. For several years, she has coordinated ... June 30, 2004 Berkeley Lab lecture: Deb Hopkins works with industries like automobile, mining and paper to improve their evaluation and measuring techniques. For several years, she has coordinated a program at Berkeley Lab funded under the Partnership for a New Generation of Vehicles, a collaboration between the federal government and the U.S. Council for Automotive Research. Nondestructive evaluation techniques to test a car's structural integrity are being developed for auto assembly lines.

LBNL

2009-09-01

176

Blasting Rocks and Blasting Cars Applied Engineering  

SciTech Connect

June 30, 2004 Berkeley Lab lecture: Deb Hopkins works with industries like automobile, mining and paper to improve their evaluation and measuring techniques. For several years, she has coordinated ... June 30, 2004 Berkeley Lab lecture: Deb Hopkins works with industries like automobile, mining and paper to improve their evaluation and measuring techniques. For several years, she has coordinated a program at Berkeley Lab funded under the Partnership for a New Generation of Vehicles, a collaboration between the federal government and the U.S. Council for Automotive Research. Nondestructive evaluation techniques to test a car's structural integrity are being developed for auto assembly lines.

LBNL

2008-07-02

177

Modelling the combustion of charcoal in a model blast furnace  

NASA Astrophysics Data System (ADS)

The pulverized charcoal (PCH) combustion in ironmaking blast furnaces is abstracting remarkable attention due to various benefits such as lowering CO2 emission. In this study, a three-dimensional CFD model is used to simulate the flow and thermo-chemical behaviours in this process. The model is validated against the experimental results from a pilot-scale combustion test rig for a range of conditions. The typical flow and thermo-chemical phenomena is simulated. The effect of charcoal type, i.e. VM content is examined, showing that the burnout increases with VM content in a linear relationship. This model provides an effective way for designing and optimizing PCH operation in blast furnace practice.

Shen, Yansong; Shiozawa, Tomo; Yu, Aibing; Austin, Peter

2013-07-01

178

Tyre-blast injuries.  

PubMed

A teenager college student was fatally injured by burst tyre air pressure while waiting on a public bus stand to catch a bus to reach her college at Kuala Lumpur. She accidentally came near the wheel while boarding when tube and tyre got burst .The air pressure had blown the girl in the air and she subsequently fell on a rough surface. The iron-locking rim of the wheel acted as a missile and hit the girl. She died on her way to the hospital. A medico-legal autopsy was performed which showed extensive injuries in the cranial and chest cavity. Head had large scalp laceration with diffuse separation and gaping from in the vault region; skull bones were fractured. Chest cavity had extensive rib fractures, lacerated lungs and haemo-thorax while externally there was no obvious injury. It requires intensive care management and screening of the victims. Tyre-blast injuries are not so common. This case exposes the hazard due to burst tyre. PMID:19329081

Murty, O P

2009-05-01

179

Blast noise impacts on sleep  

NASA Astrophysics Data System (ADS)

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.

Nykaza, Edward T.; Pater, Larry L.

2005-04-01

180

Head Kinematics Resulting from Simulated Blast Loading Scenarios.  

National Technical Information Service (NTIS)

Blast wave overpressure has been associated with varying levels of traumatic brain injury in soldiers exposed to blast loading. In realistic blast loading scenarios, the mechanisms of primary blast injury are not well known due to the complex interactions...

A. Bouamoul D. Singh D. S. Cronin P. A. Lockhart T. N. Haladuick

2012-01-01

181

Blast from explosive evaporation of carbon dioxide: experiment, modeling and physics  

Microsoft Academic Search

Explosive evaporation of a superheated liquid is a relevant hazard in the process industry. A vessel rupture\\u000aduring storage, transport or handling may lead to devastating blast effects. In order to assess the risk associated with this hazard or to design protective measures, an accurate prediction model for the blast generated after vessel rupture is needed. For this reason a

M. M. Van der Voort; A. C. Van den berg; D. J. E. M. Roekaerts; M. Xie; P. C. J. De Bruijn

2012-01-01

182

Discrete element modeling of rock blasting in benches with joints and bedding planes - initial development  

Microsoft Academic Search

A Discrete element computer program named DMC (Distinct Motion Code) has been developed for modeling rock blasting. This program employs explicit time integration and uses spherical or cylindrical elements which are represented as circles in 2-D. DMC calculations have been compared with measurements on bench blasts in the field with relatively good comparison. Structural rock mass characteristics have a significant

Preece

1995-01-01

183

A study on planar blast waves initiated by gaseous detonations. I - Estimation of initiation energy  

Microsoft Academic Search

An experimental study has been made of the initiation of planar blast waves by gaseous detonations. A gaseous detonation initiated by a DDT process is submitted into a long tube filled with air at various initial pressures. The measurement of the decay process of a produced shock wave indicates that it can be treated as a 'plane source' blast wave,

S. Ohyagi; T. Yoshihashi; Y. Harigaya

1985-01-01

184

Visualization of explosion phenomena using a high-speed video camera with an uncoupled objective lens by fiber-optic  

Microsoft Academic Search

Visualization of explosion phenomena is very important and essential to evaluate the performance of explosive effects. The phenomena, however, generate blast waves and fragments from cases. We must protect our visualizing equipment from any form of impact. In the tests described here, the front lens was separated from the camera head by means of a fiber-optic cable in order to

Nobuyuki Tokuoka; Hitoshi Miyoshi; Hideaki Kusano; Hidehiro Hata; Tetsuyuki Hiroe; Kazuhito Fujiwara; Kondo Yasushi

2008-01-01

185

BLAST: The Balloon-Borne Large Aperture Submillimeter Telescope  

NASA Technical Reports Server (NTRS)

BLAST is the Balloon-borne Large-Aperture Sub-millimeter Telescope. It will fly from a Long Duration Balloon (LDB) platform from Antarctica. The telescope design incorporates a 2 m primary mirror with large-format bolometer arrays operating at 250, 350 and 500 microns. By providing the first sensitive large-area (10 sq. deg.) sub-mm surveys at these wavelengths, BLAST will address some of the most important galactic and cosmological questions regarding the formation and evolution of stars, galaxies and clusters. Galactic and extragalactic BLAST surveys will: (1) identify large numbers of high-redshift galaxies; (2) measure photometric redshifts, rest-frame FIR luminosities and star formation rates thereby constraining the evolutionary history of the galaxies that produce the FIR and sub-mm background; (3) measure cold pre-stellar sources associated with the earliest stages of star and planet formation; (4) make high-resolution maps of diffuse galactic emission over a wide range of galactic latitudes. In addition to achieving the above scientific goals, the exciting legacy of the BLAST LDB experiment will be a catalogue of 3000-5000 extragalactic sub-mm sources and a 100 sq. deg. sub-mm galactic plane survey. Multi-frequency follow-up observations from SIRTF, ASTRO-F, and Herschel, together with spectroscopic observations and sub-arcsecond imaging from ALMA are essential to understand the physical nature of the BLAST sources.

Devlin, Mark; Ade, Peter; Bock, Jamie; Dicker, Simon; Griffin, Matt; Gunderson, Josh; Halpern, Mark; Hargrave, Peter; Hughes, David; Klein, Jeff

2004-01-01

186

Blast furnace slags as sorbents of phosphate from water solutions  

Microsoft Academic Search

The paper is focused on the sorption of phosphorus from aqueous solutions by crystalline and amorphous blast furnace slags. Slag sorption kinetics were measured, adsorption tests were carried out and the effect of acidification on the sorption properties of slags was studied. The kinetic measurements confirmed that the sorption of phosphorus on crystalline as well as amorphous slags can be

Bruno Kostura; Hana Kulveitová; Juraj Leško

2005-01-01

187

Low Cost Oxygen for Blast Furnace.  

National Technical Information Service (NTIS)

A low cost process is examined which provides oxygen enrichment of blast air for blast furnaces to increase steel production without increasing the steelmaking or final finishing facilities. The proposed process is designed to separate the oxygen from nit...

R. Jablin

1980-01-01

188

30 CFR Blasting - Surface and Underground  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Surface and Underground Blasting Electric Blasting Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION...in the same work area shall be initiated from one source. Electric BlastingâSurface and...

2010-07-01

189

Blasting, graphical interfaces and Unix  

SciTech Connect

A discrete element computer program, DMC (Distinct Motion Code) was developed to simulate blast-induced rock motion. To simplify the complex task of entering material and explosive design parameters as well as bench configuration, a full-featured graphical interface has been developed. DMC is currently executed on both Sun SPARCstation 2 and Sun SPARCstation 10 platforms and routinely used to model bench and crater blasting problems. This paper will document the design and development of the full-featured interface to DMC. The development of the interface will be tracked through the various stages, highlighting the adjustments made to allow the necessary parameters to be entered in terms and units that field blasters understand. The paper also discusses a novel way of entering non-integer numbers and the techniques necessary to display blasting parameters in an understandable visual manner. A video presentation will demonstrate the graphics interface and explains its use.

Knudsen, S. [RE/SPEC, Inc., Albuquerque, NM (United States); Preece, D.S. [Sandia National Labs., Albuquerque, NM (United States)

1993-11-01

190

BLAST: improvements for better sequence analysis  

Microsoft Academic Search

Basic local alignment search tool (BLAST) is a sequence similarity search program. The National Center for Biotechnology Information (NCBI) main- tains a BLAST server with a home page at http:\\/\\/ www.ncbi.nlm.nih.gov\\/BLAST\\/. We report here on recent enhancements to the results produced by the BLAST server at the NCBI. These include features to highlight mismatches between similar sequences, showwherethequerywasmaskedforlow-complexity sequence, and

Jian Ye; Scott Mcginnis; Thomas L. Madden

2006-01-01

191

Proceedings of the fourth mini-symposium on explosives and blasting research  

SciTech Connect

Eleven papers were presented at this mini-symposium covering the following topics: estimation of damage produced by blasting; stress measurements in coal; channel effect for ANFO slurries and emulsions; design of blasts for surface coal mining; measurement of fragmentation efficiency; measurement of amplitude-frequency components of ground vibrations; computer-aided design for millisecond-delayed initiators; safety against lightning in blast systems; design of a mechanical stemming aid; and measurement of explosive reactivity of explosive contaminated solid wastes. All papers have been processed separately for inclusion on the data base.

Not Available

1991-01-01

192

Blast waves in rotating media.  

NASA Technical Reports Server (NTRS)

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.

Rossner, L. F.

1972-01-01

193

Explosive blasting method and means  

SciTech Connect

An explosive blasting method and apparatus are claimed for producing rock fragmentation and reducing the amplitude of seismic effects (ground vibration) in the vicinity of the blast. It utilizes an air gap method and apparatus for superheating the air surrounding the charge in a borehole. This raises the pressure therein coupled with the use of multiple detonation points along the borehole for the reduction of burn time. This reduces the quantity of explosives used along with a marked reduction of seismic shock, sound, and dust effects to the surrounding area.

Bowling, D.S.; Moore, R.N.

1983-05-10

194

Community response to blast noise  

NASA Astrophysics Data System (ADS)

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.

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

2005-09-01

195

Simulation of Blast Waves with Headwind  

NASA Technical Reports Server (NTRS)

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.

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

2005-01-01

196

Blast casting requires fresh assessment of methods  

SciTech Connect

The article says that because blast casting differs from conventional blasting, our ideas about explosive products, drilling, and initiating methods must change. The author discusses how to select a casting explosive and what factors are important in its selection. He also looks at how to determine the best blasthole diameter and burden blasting pattern.

Pilshaw, S.R.

1987-08-01

197

Method of loading blast hole with explosive  

Microsoft Academic Search

A technique for loading an ammonium nitrate-fuel oil (ANFO) explosive mixture upward into a vertical blast hole is discussed. The blast hole may extend as much as 70 ft or more from the open end at the face of the rock structure into which the blast hole is drilled. In order to achieve adequate packing in the hole, the ANFO

1977-01-01

198

29 CFR 1926.912 - Underwater blasting.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Underwater blasting. 1926.912 Section 1926...the Use of Explosives § 1926.912 Underwater blasting. (a) A blaster shall...of explosives aboard vessels used in underwater blasting operations shall be...

2013-07-01

199

Predictions of Experimentally Observed Stochastic Ground Vibrations Induced by Blasting  

PubMed Central

In the present paper, we investigate the blast induced ground motion recorded at the limestone quarry “Suva Vrela” near Kosjeri?, which is located in the western part of Serbia. We examine the recorded signals by means of surrogate data methods and a determinism test, in order to determine whether the recorded ground velocity is stochastic or deterministic in nature. Longitudinal, transversal and the vertical ground motion component are analyzed at three monitoring points that are located at different distances from the blasting source. The analysis reveals that the recordings belong to a class of stationary linear stochastic processes with Gaussian inputs, which could be distorted by a monotonic, instantaneous, time-independent nonlinear function. Low determinism factors obtained with the determinism test further confirm the stochastic nature of the recordings. Guided by the outcome of time series analysis, we propose an improved prediction model for the peak particle velocity based on a neural network. We show that, while conventional predictors fail to provide acceptable prediction accuracy, the neural network model with four main blast parameters as input, namely total charge, maximum charge per delay, distance from the blasting source to the measuring point, and hole depth, delivers significantly more accurate predictions that may be applicable on site. We also perform a sensitivity analysis, which reveals that the distance from the blasting source has the strongest influence on the final value of the peak particle velocity. This is in full agreement with previous observations and theory, thus additionally validating our methodology and main conclusions.

Kostic, Sr?an; Perc, Matjaz; Vasovic, Nebojsa; Trajkovic, Slobodan

2013-01-01

200

Blast wave diagnostic for the petawatt laser system  

SciTech Connect

We report on a diagnostic to measure the trajectory of a blast wave propagating through a plastic target 400 {micro}m thick. This blast wave is generated by the irradiation of the front surface of the target with {approximately} 400 J of 1 {micro}m laser radiation in a 20 ps pulse focused to a {approximately} 50 {micro}m diameter spot, which produces an intensity in excess of 1O{sup 18} W/cm{sup 2}. These conditions approximate a point explosion and a blast wave is predicted to be generated with an initial pressure nearing 1 Gbar which decays as it travels approximately radially outward from the interaction region We have utilized streaked optical pyrometry of the blast front to determine its time of arrival at the rear surface of the target Applications of a self-similar Taylor-Sedov blast wave solution allows the amount of energy deposited to be estimated The experiment, LASNEX design simulations and initial results are discussed.

Budil, K. S., LLNL

1998-06-03

201

Blast wave diagnostic for the Petawatt laser system  

SciTech Connect

We report on a diagnostic to measure the trajectory of a blast wave propagating through a plastic target 400 {mu}m thick. This blast wave is generated by the irradiation of the front surface of the target with {approximately}400 J of 1 {mu}m laser radiation in a 20 ps pulse focused to a {approximately}50 {mu}m diameter spot, which produces an intensity in excess of 10{sup 18}thinspW/cm{sup 2}. These conditions approximate a point explosion and a blast wave is predicted to be generated with an initial pressure nearing 1 Gbar which decays as it travels approximately radially outward from the interaction region. We have utilized streaked optical pyrometry of the blast front to determine its time of arrival at the rear surface of the target. Applications of a self-similar Taylor{endash}Sedov blast wave solution allows the amount of energy deposited to be estimated. The experiment, LASNEX design simulations and initial results are discussed. {copyright} {ital 1999 American Institute of Physics.}

Budil, K.S.; Gold, D.M.; Estabrook, K.G.; Remington, B.A.; Kane, J.; Bell, P.M.; Pennington, D.; Brown, C.; Hatchett, S.; Koch, J.A.; Key, M.H.; Perry, M.D. [Lawrence Livermore National Laboratory, P.O. Box 808, L-21, Livermore, California 94550 (United States)] [Lawrence Livermore National Laboratory, P.O. Box 808, L-21, Livermore, California 94550 (United States)

1999-01-01

202

A General Viscosity Model for Molten Blast Furnace Slag  

NASA Astrophysics Data System (ADS)

Blast furnace slag is the most abundant slag in the steel industry. Its metallurgical properties are determined to a great extent by its viscosity. Therefore, it is necessary to establish a reliable viscosity model for blast furnace slag. In the current work, a simple, accurate, and physically meaningful viscosity model for a wide composition range of blast furnace slags is developed based on the Vogel-Fulcher-Tammann (VFT) equation: log ? = A + B/( T - C). The model is calibrated by a database containing 365 compositions and 1233 measurements of synthetic and industrial slags. The parameter A has a value of -3.10. The parameters B and C are related to the mass fraction ratio of (CaO + MgO) to (SiO2 + Al2O3) and liquidus temperature of the slag, respectively. Present viscosity model accurately predicts the viscosity of blast furnace slag with relative average error (?) of 0.211 (±0.180) and root mean square error (RMSE) of 0.239 Pa·s. A slight modification of this model can also predict the glass transition temperature of blast furnace slag satisfactorily.

Gan, Lei; Lai, Chaobin

2014-06-01

203

Blast Loading Experiments of Developed Surrogate Models for TBI Scenarios  

NASA Astrophysics Data System (ADS)

This study aims to characterize the interaction of explosive blast waves through simulated anatomical systems. We have developed physical models and a systematic approach for testing traumatic brain injury (TBI) mechanisms and occurrences. A simplified series of models consisting of spherical PMMA shells followed by SLA prototyped skulls housing synthetic gelatins as brain simulants have been utilized. A series of experiments was conducted with the simple geometries to compare the sensitivity of the system response to mechanical properties of the simulants under high strain-rate explosive blasts. Small explosive charges were directed at the models to produce a realistic blast wave in a scaled laboratory setting. Blast profiles were measured and analyzed to compare system response severity. High-speed shadowgraph imaging captured blast wave interaction with the head model while particle tracking captured internal response for displacement and strain correlation. The results suggest amplification of shock waves inside the head due to impedance mismatches. Results from the strain correlations added to the theory of internal shearing between tissues.

Alley, Matthew; Son, Steven

2009-06-01

204

System for supplying blasting media to a media blasting system  

SciTech Connect

This patent describes a pressure pot system for supplying blasting media under pressure to a pressurized blasting conduit for feeding blasting media to one or more blasting guns, the system including a media storage means and a first and second pressure chambers with means for pressurizing and exhausting the first and second chambers, the media storage means being stacked above the pressure chambers with the first pressure chamber stacked above the second pressure chamber; first and second media valve means for providing communication between the storage means and the first pressure chamber and between the pressure chambers, respectively; air valve means for controlling the air pressurizing and exhausting of the first and second pressure chambers, the improvement comprising: means for opening and closing the first and second media valve means and the air valve means, the first, second and air valve means being offset from each other in both vertical and horizontal dimensions; push rods extending vertically upward from the valve means and spaced one from the other for actuating the valve means to open and close the same; an overhead cam shaft means mounted above the push rods and having a plurality of spaced cams, each of the cams being aligned and operatively associated with one of the push rods for actuating the push rods and thereby the valve means to control the opening and closing of the first and second media valve means and the air valve means; and actuating means for actuating the cam shaft means.

Van Kuiken, L.L. Jr.

1988-10-25

205

Temporally resolved planar measurements of transient phenomena in a partially pre-mixed swirl flame in a gas turbine model combustor  

SciTech Connect

This paper presents observations and analysis of the time-dependent behavior of a 10 kW partially pre-mixed, swirl-stabilized methane-air flame exhibiting self-excited thermo-acoustic oscillations. This analysis is based on a series of measurements wherein particle image velocimetry (PIV) and planar laser-induced fluorescence (PLIF) of the OH radical were performed simultaneously at 5 kHz repetition rate over durations of 0.8 s. Chemiluminescence imaging of the OH{sup *} radical was performed separately, also at 5 kHz over 0.8 s acquisition runs. These measurements were of sufficient sampling frequency and duration to extract usable spatial and temporal frequency information on the medium to large-scale flow-field and heat-release characteristics of the flame. This analysis is used to more fully characterize the interaction between the self-excited thermo-acoustic oscillations and the dominant flow-field structure of this flame, a precessing vortex core (PVC) present in the inner recirculation zone. Interpretation of individual measurement sequences yielded insight into various physical phenomena and the underlying mechanisms driving flame dynamics. It is observed for this flame that location of the reaction zone tracks large-scale fluctuations in axial velocity and also conforms to the passage of large-scale vortical structures through the flow-field. Local extinction of the reaction zone in regions of persistently high principal compressive strain is observed. Such extinctions, however, are seen to be self healing and thus do not induce blowout. Indications of auto-ignition in regions of unburned gas near the exit are also observed. Probable auto-ignition events are frequently observed coincident with the centers of large-scale vortical structures, suggesting the phenomenon is linked to the enhanced mixing and longer residence times associated with fluid at the core of the PVC as it moves through the flame. (author)

Boxx, I.; Stoehr, M.; Meier, W. [Institut fuer Verbrennungstechnik, Deutsches Zentrum fuer Luft-und Raumfahrt (DLR), Pfaffenwaldring 38-40, D-70569 Stuttgart (Germany); Carter, C. [Air Force Research Laboratory (AFRL)/PRAS, 1950 Fifth St, Wright-Patterson AFB, OH (United States)

2010-08-15

206

How to Measure Qualitative Understanding of DC-Circuit Phenomena - Taking a Closer Look at the External Representations of 9-Year-Olds  

NASA Astrophysics Data System (ADS)

Pupils' qualitative understanding of DC-circuit phenomena is reported to be weak. In numerous research reports lists of problems in understanding the functioning of simple DC-circuits have been presented. So-called mental model surveys have uncovered difficulties in different age groups, and in different phases of instruction. In this study, the concept of qualitative understanding, and the content or position of reported mental models of DC-circuit phenomena are discussed. On the grounds of this review, new tools for investigating qualitative understanding and analysing external representations of DC-circuit phenomena are presented. According to this approach, the external representations of DC-circuit phenomena that describe pupils' expressed conceptions of the topic should include both empirical-based models and theoretical explanations. In the empirical part of this study , third-graders (9-year-olds) learning DC-circuit phenomena in a comprehensive school in a small group were scrutinised. The focus of the study is the external representations manifested in the talk of the small group. The study challenges earlier studies, which claim that children exhibit a wide range of qualitative difficulties when learning DC-circuit phenomena. In this study it will be shown that even in the case of abstract subject matter like DC-circuit phenomena, small groups that highlight empirical-based modelling and activate talk can be a fruitful learning environment, where pupils' qualitative understanding really develops. Thus, the study proposes taking a closer look at pupils' external representations concerning DC-circuit phenomena.

Kallunki, Veera

2013-04-01

207

Community response to blast noise  

Microsoft Academic Search

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

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

2005-01-01

208

Strong Blast Wave Computer Programs.  

National Technical Information Service (NTIS)

This report describes a computer program package for the computation of the flow field within a strong blast bubble. The programs are based on Sedov-Laporte-Chang formulas and compute any of the following: shock front location and corresponding flow value...

A. Celmins

1980-01-01

209

Drill and Blast Tunneling Practices  

Microsoft Academic Search

High-performance drill and blast methods for tunnel construction require that each of the individual working elements that constitute the construction process are optimized and considered as a system of sequential and parallel activities. The advantage of integrating the logistic backup systems facilitates an increase in performance. To achieve increased production, it is necessary to improve the drilling, explosive loading, temporary

Gerhard Girmscheid; Cliff Schexnayder

2002-01-01

210

Blasting, graphical interfaces and Unix  

Microsoft Academic Search

A discrete element computer program, DMC (Distinct Motion Code) was developed to simulate blast-induced rock motion. To simplify the complex task of entering material and explosive design parameters as well as bench configuration, a full-featured graphical interface has been developed. DMC is currently executed on both Sun SPARCstation 2 and Sun SPARCstation 10 platforms and routinely used to model bench

S. Knudsen; D. S. Preece

1993-01-01

211

Gun Blast from Naval Guns.  

National Technical Information Service (NTIS)

The available data on gun blasts from naval guns are complied utilizing computer curve fitting techniques. Curves of peak free-air pressure are presented for all naval guns, ranging in size from 20 mm to 16in./50. In addition, curves of arrival time, dura...

M. F. Walther

1972-01-01

212

Volcanic Dust Phenomena  

Microsoft Academic Search

THE phenomena connected with the volcanic dust are undergoing distinct changes. In common with observers in the south of England, I noted the fresh appearance of the dust phenomena in the end of June, especially on June 26, but they were not very striking until August 1. At first the most decidedly volcanic feature was the great corona round the

T. W. Backhouse

1902-01-01

213

Coupled Phenomena in Chemistry.  

ERIC Educational Resources Information Center

Various phenomena in chemistry and biology can be understood through Gibbs energy utilization. Some common phenomena in chemistry are explained including neutralization, hydrolysis, oxidation and reaction, simultaneous dissociation equilibrium of two weak acids, and common ion effect on solubility. (Author/SA)

Matsubara, Akira; Nomura, Kazuo

1979-01-01

214

Laboratory blast wave driven instabilities  

NASA Astrophysics Data System (ADS)

This presentation discusses experiments well-scaled to the blast wave driven instabilities during the explosion phase of SN1987A. Blast waves 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. 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 ?m 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 a perturbed interface, which produces nonlinear, unstable growth dominated by the Rayleigh-Taylor (RT) instability. Recent experiments have been performed using complex initial conditions featuring a three-dimensional interface structure with a wavelength of 71 ?m in two orthogonal directions, at times supplemented by an additional sinusoidal mode of 212 ?m or 424 ?m. We have detected the interface structure under these conditions, using dual orthogonal radiographs on some shots, and will show some of the resulting data. Recent advancements in our x-ray backlighting 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. Current simulations do not show this phenomenon. This presentation will discuss the amount of mass in these spike extensions as well as the error analysis of this calculation. Future experiments will also be discussed. They will be focusing on realistic initial conditions based on 3D stellar evolution models. This research was sponsored by the Stewardship Science Academic Alliances Program through DOE Research Grants DE-FG52-07NA28058, DE-FG52-04NA00064, and other grants and contracts.

Kuranz, Carolyn

2008-04-01

215

Behind Armor Blast (BAB) caused by shaped charges  

Microsoft Academic Search

Steel targets were shot by shaped charges. Instead of using conventional copper liners, in this test series liners made of aluminium and magnesium were used. The jet velocities ranged from 5 to 7 mm\\/?s. Behind the steel target a large Behind Armor Blast (BAB) - effect occurred. The measurement of this BAB was carried out by pressure and temperature probes

Werner Arnold; Frank K. Schäfer

1999-01-01

216

Idaho National Laboratory Experimental Program to Measure the Flow Phenomena in a Scaled Model of a Prismatic Gas-Cooled Reactor Lower Plenum for Validation of CFD Codes  

SciTech Connect

The experimental program that is being conducted at the Matched Index-of-Refraction (MIR) Flow Facility at Idaho National Laboratory (INL) to obtain benchmark data on measurements of flow phenomena in a scaled model of a prismatic gas-cooled reactor lower plenum using 3-D Particle Image Velocimetry (PIV) is presented. A description of the scaling analysis, experimental facility, 3-D PIV system, measurement uncertainties and analysis, experimental procedures and samples of the data sets that have been obtained are included. Samples of the data set that will be presented include mean-velocity-field and turbulence data in an approximately 1:7 scale model of a region of the lower plenum of a typical prismatic gas-cooled reactor (GCR) similar to a General Atomics Gas-Turbine-Modular Helium Reactor (GTMHR) design. This experiment has been selected as the first Standard Problem endorsed by the Generation IV International Forum. The flow in the lower plenum consists of multiple jets injected into a confined cross flow - with obstructions. The model consists of a row of full circular posts along its centerline with half-posts on the two parallel walls to approximate flow scaled to that expected from the staggered parallel rows of posts in the reactor design. The model is fabricated from clear, fused quartz to match the refractive-index of the mineral oil working fluid. The benefit of the MIR technique is that it permits high-quality measurements to be obtained without locating intrusive transducers that disturb the flow field and without distortion of the optical paths. An advantage of the INL MIR system is its large size which allows improved spatial and temporal resolution compared to similar facilities at smaller scales. Results concentrate on the region of the lower plenum near its far reflector wall (away from the outlet duct). Inlet jet Reynolds numbers (based on the jet diameter and the time-mean average flow rate) are approximately 4,300 and 12,400. The measurements reveal developing, non-uniform flow in the inlet jets and complicated flow patterns in the model lower plenum. Data include three-dimensional vector plots, data displays along the coordinate planes (slices) and charts that describe the component flows at specific regions in the model. Information on inlet velocity profiles is also presented.

Hugh M. McIlroy Jr.; Donald M. McEligot; Robert J. Pink

2008-09-01

217

Stochastic properties of partial-discharge phenomena  

Microsoft Academic Search

The author presents a bibliography and survey of the literature concerned with theory and measurement of the stochastic behavior of pulsating partial-discharge (PD) phenomena that can occur when insulation is subjected to electrical stress. The types of PD phenomena considered include AC and DC generated electron avalanches, pulsating positive and negative corona in gases, and PD that occur in liquid

R. J. Van Brunt

1991-01-01

218

Topological Anderson insulator phenomena  

NASA Astrophysics Data System (ADS)

We study the nature of the disorder-induced quantized conductance, i.e., the phenomena of topological Anderson insulator (TAI). The disorder effect in several different systems where the anomalous Hall effect exists is numerically studied using the tight-binding Hamiltonian. It is found that the TAI phenomena can also exist in the modified Dirac model where the quadratic corrections k2?z are included and the electron-hole symmetry is kept. These phenomena also occur in the graphene system with the next-nearest-neighbor coupling and the staggered sublattice potential. For the graphene sheet with Rashba spin-orbit interaction as well as an exchange field, a precursor of TAI is observed. A comparison between the localization length of the two-dimensional ribbon and two-dimensional cylinder structures clearly reveals the topological nature of these phenomena. Furthermore, analysis on the local current density in anomalous quantum Hall systems where the TAI phenomena may or may not arise reveals the nature of TAI phenomena. In the presence of small disorders, the conductance is not quantized and the bulk and edge states coexist in the system. As disorder strength increases, the bulk state is quickly destroyed, while the robust edge state may survive. When the edge state is robust enough to sustain the strong disorder that completely kills the bulk state, TAI phenomena arise.

Xing, Yanxia; Zhang, Lei; Wang, Jian

2011-07-01

219

Science and Paranormal Phenomena  

SciTech Connect

In order to ground my approach to the study of paranormal phenomena, I first explain my operational approach to physics, and to the ''historical'' sciences of cosmic, biological, human, social and political evolution. I then indicate why I believe that ''paranormal phenomena'' might-but need not- fit into this framework. I endorse the need for a new theoretical framework for the investigation of this field presented by Etter and Shoup at this meeting. I close with a short discussion of Ted Bastin's contention that paranormal phenomena should be defined as contradicting physics.

Noyes, H. Pierre

1999-06-03

220

Analysis of microscopic magnitudes of radiative blast waves launched in xenon clusters with collisional-radiative steady-state simulations  

NASA Astrophysics Data System (ADS)

Radiative shock waves play a pivotal role in the transport energy into the stellar medium. This fact has led to many efforts to scale the astrophysical phenomena to accessible laboratory conditions and their study has been highlighted as an area requiring further experimental investigations. Low density material with high atomic mass is suitable to achieve radiative regime, and, therefore, low density xenon gas is commonly used for the medium in which the radiative shocks such as radiative blast waves propagate. In this work, by means of collisional-radiative steady-state calculations, a characterization and an analysis of microscopic magnitudes of laboratory blast waves launched in xenon clusters are made. Thus, for example, the average ionization, the charge state distribution, the cooling time or photon mean free paths are studied. Furthermore, for a particular experiment, the effects of the self-absorption and self-emission in the specific intensity emitted by the shock front and that is going through the radiative precursor are investigated. Finally, for that experiment, since the electron temperature is not measured experimentally, an estimation of this magnitude is made both for the shock shell and the radiative precursor.

Rodriguez, R.; Espinosa, G.; Gil, J. M.; Florido, R.; Rubiano, J. G.; Mendoza, M. A.; Martel, P.; Minguez, E.; Symes, D. R.; Hohenberger, M.; Smith, R. A.

2013-08-01

221

Alumina grit blasting parameters for surface preparation in the plasma spraying operation  

NASA Astrophysics Data System (ADS)

This paper examines how the grit blasting process influences the surface roughness of different sub-strates, the grit residue, and the grit erosion. The influence of grit blasting conditions on induced sub-strate residual stresses is also discussed. Aluminum alloy, cast iron, and hard steel were blasted with white alumina grits of 0.5,1, and 1.4 mm mean diameters. Grit blasting was performed using either a suction-type or a pressure-type machine equipped with straight nozzles made of B4C. The influence of the follow-ing parameters was studied: grit blasting distance (56 to 200 mm), blasting time (3 to 30 s), angle between nozzle and blasted surface (30°, 60°, 90°), and blasting pressure (0.2 to 0.7 MPa). The roughness of the substrate was characterized either by using a perthometer or by image analysis. The grit residue remain-ing at the blasted surface was evaluated after cleaning by image analysis. The residual stresses induced by grit blasting were determined by using the incremental hole drilling method and by measuring the de-flection of grit-blasted beams. Grit size was determined to be the most important influence on roughness. The average values of Ra and Rt and the percentage of grit residue increased with grit size as well as the depth of the plastic zone under the substrate. An increase of the pressure slightly increased the values of Äa and Rt but also promoted grit breakdown and grit residue. A blasting time of 3 to 6 s was sufficient to obtain the highest roughness and limit the grit breakdown. The residual stresses generated under the blasted surface were compressive, and the depth of the affected zone depended on the grit diameter, the blasting pressure, and the Young’s modulus of the substrate. More-over, the maximum residual stress was reached at the limit of the plastic zone (i.e., several tenths of a mil-limeter below the substrate surface).

Mellali, M.; Grimaud, A.; Leger, A. C.; Fauchais, P.; Lu, J.

1997-06-01

222

Multiphase-flow numerical modeling of the 18 May 1980 lateral blast at Mount St. Helens, USA  

USGS Publications Warehouse

Volcanic lateral blasts are among the most spectacular and devastating of natural phenomena, but their dynamics are still poorly understood. Here we investigate the best documented and most controversial blast at Mount St. Helens (Washington State, United States), on 18 May 1980. By means of three-dimensional multiphase numerical simulations we demonstrate that the blast front propagation, fi nal runout, and damage can be explained by the emplacement of an unsteady, stratifi ed pyroclastic density current, controlled by gravity and terrain morphology. Such an interpretation is quantitatively supported by large-scale observations at Mount St. Helens and will infl uence the defi nition and predictive mapping of hazards on blast-dangerous volcanoes worldwide. ?? 2011 Geological Society of America.

Ongaro, T. E.; Widiwijayanti, C.; Clarke, A. B.; Voight, B.; Neri, A.

2011-01-01

223

Background to plastic media blasting  

NASA Astrophysics Data System (ADS)

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.

Foster, Terry

1995-04-01

224

HIGH PRODUCTIVITY VACUUM BLASTING SYSTEM  

SciTech Connect

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.

William S. McPhee

2001-08-31

225

Cost Comparative Analysis of Blast Mitigation Technologies with Regard to Explosive Remnants of War (ERW).  

National Technical Information Service (NTIS)

The purpose of this MBA Project is to investigate and analyze different forms of blast mitigation technologies that provide safe temporary storage, and in the event of a detonation, provide protection measures for personnel and property. A comprehensive c...

P. J. Mahoney

2011-01-01

226

Full-Trajectory Diagnosis of Laser-Driven Radiative Blast Waves in Search of Thermal Plasma Instabilities  

SciTech Connect

Experimental investigations into the dynamics of cylindrical, laser-driven, high-Mach-number shocks are used to study the thermal cooling instability predicted to occur in astrophysical radiative blast waves. A streaked Schlieren technique measures the full blast-wave trajectory on a single-shot basis, which is key for observing shock velocity oscillations. Electron density profiles and deceleration parameters associated with radiative blast waves were recorded, enabling the calculation of important blast-wave parameters including the fraction of radiated energy, {epsilon}, as a function of time for comparison with radiation-hydrodynamics simulations.

Moore, A. S.; Gumbrell, E. T.; Lazarus, J.; Hohenberger, M.; Robinson, J. S.; Smith, R. A.; Plant, T. J. A.; Symes, D. R.; Dunne, M. [Plasma Physics Division, AWE Aldermaston, RG7 4PR. United Kingdom (United Kingdom); Laser Consortium, Blackett Laboratory, Imperial College, London SW7 2BZ. United Kingdom (United Kingdom); Ministry of Defence, Foxhill, Bath BA1 5AB. United Kingdom (United Kingdom); Central Laser Facility, Rutherford Appleton Laboratory, Oxfordshire OX11 0QX. United Kingdom (United Kingdom)

2008-02-08

227

Effect of Grit Blasting on Substrate Roughness and Coating Adhesion  

SciTech Connect

Statistically designed experiments were performed to compare the surface roughnesses produced by grit blasting A36/1020 steel with different abrasives. Grit blast media, blast pressure, and working distance were varied using a Box-type statistical design of experiment (SDE) approach. The surface textures produced by four metal grits (HG16, HG18, HG25, and HG40) and three conventional grits (copper slag, coal slag, and chilled iron) were compared. Substrate roughness was measured using surface profilometry and correlated with operating parameters. The HG16 grit produced the highest surface roughness of all the grits tested. Aluminum and zinc-aluminum coatings were deposited on the grit-blasted substrates using a Twin-Wire Electric Arc (TWEA) process. Bond strength of the coatings was measured with a portable adhesion tester in accordance with ASTM standard D4541. The coatings on substrates roughened with steel grit exhibit superior bond strength to those on substrates prepared with conventional grit. For aluminum coatings sprayed onto surfaces prepared with the HG16 grit, the bond strength was most influenced by current, spray distance, and spray gun pressure (in that order). The highest bond strength for the zinc-aluminum coatings was attained on surfaces prepared using the metal grits.

Dominic Varacalle; Donna Guillen; Doug Deason; William Rhodaberger; Elliott Sampson

2006-09-01

228

A miniature pressure sensor for blast event evaluation  

NASA Astrophysics Data System (ADS)

Traumatic brain injury (TBI) is a great potential threat to people who deal with explosive devices. Protection from TBI has attracted more and more interest. Great efforts have been taken to the studies on the understanding of the propagation of the blast events and its effect on TBI. However, one of the biggest challenges is that the current available pressure sensors are not fast enough to capture the blast wave especially the transient period. This paper reports an ultrafast pressure sensor that could be very useful for analysis of the fast changing blast signal. The sensor is based on Fabry-Perot (FP) principle. It uses a 45º angle polished fiber sitting in a V-groove on a silicon chip. The endface of the angle polished fiber and the diaphragm which is lifted off on the side wall of the V-groove form the FP cavity. The sensor is very small and can be mounted on different locations of a helmet to measure blast pressure simultaneously. The tests were conducted at Natick Soldier Research, Development, and Engineering Center (NSRDEC) in Natick, MA. The sensors were mounted in a shock tube, side by side with the reference sensors, to measure a rapidly increased pressure. The results demonstrated that our sensors' responses agreed well with those from the electrical reference sensors and their response time is comparable.

Wu, Nan; Wang, Wenhui; Tian, Ye; Niezrecki, Christopher; Wang, Xingwei

2011-05-01

229

Laboratory blast wave driven instabilities  

NASA Astrophysics Data System (ADS)

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 ?m 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 Facility).

Kuranz, Carolyn

2008-11-01

230

Blasting Injuries in Surface Mining with Emphasis on Flyrock and Blast Area Security.  

National Technical Information Service (NTIS)

Blasting is a hazardous component of surface mining. Serious injuries and fatalities result from improper judgement or practice during rock blasting. This paper describes several fatal injury case studies, analyzes causative factors, and emphasizes preven...

D. K. Ingram G. L. Mowrey T. R. Rehak T. S. Bajpayee

2008-01-01

231

Procedure for calculating drilling and blasting parameters and experience of blasting in constrained material  

Microsoft Academic Search

Tight-face blasting is a production method which provides an improvement in drilling and blasting (DAB) indices and it involves the fact that the blasted volume over the breaking front is 'overloaded' by constrained material. The constraining material used is previously broken rock mass which has an acoustic stiffness several times less than the material being broken and a capacity to

N. I. Semenyakin; V. V. Arshavskii; A. S. Bykovtsev; V. N. Oparin; V. B. Vil'chinskii

1993-01-01

232

Surface assessment and modification of concrete using abrasive blasting  

NASA Astrophysics Data System (ADS)

Composite systems are applied to concrete substrates to strengthen and extend the service life. Successful restoration or rehabilitation requires surface preparation prior to the application of the overlay. Surface coatings, waterproofing systems, and other external surface applications also require surface preparation prior to application. Abrasive blast media is often used to clean and uniformly roughen the substrate. The appropriate surface roughness is necessary to facilitate a strong bond between the existing substrate and overlay. Thus, surface modification using abrasive blast media (sand and dry ice), their respective environmental effects, surface roughness characterization prior to and after blasting, and the adhesion between the substrate and overlay are the focus of this dissertation. This dissertation is comprised of an introduction, a literature review, and four chapters, the first of which addresses the environmental effects due to abrasive blasting using sand, water, and dry ice. The assessment considered four response variables: carbon dioxide (CO2) emissions, fuel and energy consumption, and project duration. The results indicated that for sand blasting and water jetting, the primary factor contributing to environmental detriment was CO22 emissions from vehicular traffic near the construction site. The second chapter is an analysis of the International Concrete Repair Institute's (ICRI) concrete surface profiles (CSPs) using 3-D optical profilometry. The primary objective was to evaluate the suitability of approximating the 3-D surface (areal) parameters with those extracted from 2-D (linear) profiles. Four profile directions were considered: two diagonals, and lines parallel and transverse to the longitudinal direction of the mold. For any CSP mold, the estimation of the 3-D surface roughness using a 2-D linear profile resulted in underestimation and overestimation errors exceeding 50%, demonstrating the inadequacy of 2-D linear profiles to approximate the 3-D concrete surface profiles. The errors were reduced when a weighted average of the four linear profiles approximated the corresponding 3-D parameter. The following chapter considers the parametric and sensitivity of concrete surface topography measurements. The weighted average of the four 2-D profiles consistently resulted in underestimation of the corresponding 3-D parameters: the dispersion of surface elevations (Sq) and the roughness (Sa). Results indicated the 3-D parameter, Sq, had the least sensitivity to data point reduction. The final chapter investigated surface modification using dry ice and sand blasting. The overall objective was to evaluate the change in the 3-D surface roughness (Sa) following blasting as functions of mix design and as induced by freeze-thaw cycling, and to compare the results obtained using dry ice with those obtained using sand as the blasting media. In general, sand blasting produced larger changes in Sa compared to dry ice blasting for the concrete mix designs considered. The primary mechanism responsible for altering the surface topography of the concrete was the scaling of the superficial cement paste layer on the exposed surface, which was due to freeze-thaw cycling. The largest relative change in roughness following blasting occurred in the control samples, which had not undergone freeze-thaw cycling.

Millman, Lauren R.

233

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

234

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

235

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

236

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

237

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

238

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

239

30 CFR 75.1310 - Explosives and blasting equipment.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Explosives and blasting equipment. 75.1310 Section...SAFETY STANDARDS-UNDERGROUND COAL MINES Explosives and Blasting § 75.1310 Explosives and blasting equipment. (a) Only...

2013-07-01

240

Factors in Selecting and Applying Commercial Explosives and Blasting Agents.  

National Technical Information Service (NTIS)

In the report commercial blasting compounds are classified according to their nitroglycerin (or equivalent explosive oil) and ammonium nitrate content as dynamites, gelatins, blasting agents, military explosives, and blasting accessories. The ingredients ...

R. A. Dick

1968-01-01

241

30 CFR 75.1316 - Preparation before blasting.  

Code of Federal Regulations, 2010 CFR

...Tests shall be conducted using a blasting multimeter or other instrument...designed for such use. (3) The blasting cable or detonator circuitry...approaching each other, cutting, drilling and blasting shall be done at only one...

2010-07-01

242

30 CFR 75.1316 - Preparation before blasting.  

Code of Federal Regulations, 2010 CFR

...Tests shall be conducted using a blasting multimeter or other instrument...designed for such use. (3) The blasting cable or detonator circuitry...approaching each other, cutting, drilling and blasting shall be done at only one...

2009-07-01

243

30 CFR 75.1316 - Preparation before blasting.  

Code of Federal Regulations, 2010 CFR

...Tests shall be conducted using a blasting multimeter or other instrument...designed for such use. (3) The blasting cable or detonator circuitry...approaching each other, cutting, drilling and blasting shall be done at only one...

2012-07-01

244

30 CFR 75.1316 - Preparation before blasting.  

Code of Federal Regulations, 2010 CFR

...Tests shall be conducted using a blasting multimeter or other instrument...designed for such use. (3) The blasting cable or detonator circuitry...approaching each other, cutting, drilling and blasting shall be done at only one...

2011-07-01

245

Coupled rock motion and gas flow modeling in blasting.  

National Technical Information Service (NTIS)

The spherical element computer code DMC (Distinct Motion Code) used to model rock motion resulting from blasting has been enhanced to allow routine computer simulations of bench blasting. The enhancements required for bench blast simulation include: (1) m...

D. S. Preece S. D. Knudsen

1991-01-01

246

Tryckverkan i Slutna Volymer. (Blast Effects in Confined Volumes).  

National Technical Information Service (NTIS)

The report gives a brief presentation of blast effects in confined volumes. In particular, blast effects in naval structures are discussed. Examples of typical structural damages and simple methods for assessment of blast effects are given. Further on, me...

L. Fast

2001-01-01

247

Implications of blast exposure for central auditory function: a review.  

PubMed

Auditory system functions, from peripheral sensitivity to central processing capacities, are all at risk from a blast event. Accurate encoding of auditory patterns in time, frequency, and space are required for a clear understanding of speech and accurate localization of sound sources in environments with background noise, multiple sound sources, and/or reverberation. Further work is needed to refine the battery of clinical tests sensitive to the sorts of central auditory dysfunction observed in individuals with blast exposure. Treatment options include low-gain hearing aids, remote-microphone technology, and auditory-training regimens, but clinical evidence does not yet exist for recommending one or more of these options. As this population ages, the natural aging process and other potential brain injuries (such as stroke and blunt trauma) may combine with blast-related brain changes to produce a population for which the current clinical diagnostic and treatment tools may prove inadequate. It is important to maintain an updated understanding of the scope of the issues present in this population and to continue to identify those solutions that can provide measurable improvements in the lives of Veterans who have been exposed to high-intensity blasts during the course of their military service. PMID:23341279

Gallun, Frederick J; Lewis, M Samantha; Folmer, Robert L; Diedesch, Anna C; Kubli, Lina R; McDermott, Daniel J; Walden, Therese C; Fausti, Stephen A; Lew, Henry L; Leek, Marjorie R

2012-01-01

248

Rodent model of direct cranial blast injury.  

PubMed

Traumatic brain injury resulting from an explosive blast is one of the most serious wounds suffered by warfighters, yet the effects of explosive blast overpressure directly impacting the head are poorly understood. We developed a rodent model of direct cranial blast injury (dcBI), in which a blast overpressure could be delivered exclusively to the head, precluding indirect brain injury via thoracic transmission of the blast wave. We constructed and validated a Cranium Only Blast Injury Apparatus (COBIA) to deliver blast overpressures generated by detonating .22 caliber cartridges of smokeless powder. Blast waveforms generated by COBIA replicated those recorded within armored vehicles penetrated by munitions. Lethal dcBI (LD(50) ? 515?kPa) was associated with: (1) apparent brainstem failure, characterized by immediate opisthotonus and apnea leading to cardiac arrest that could not be overcome by cardiopulmonary resuscitation; (2) widespread subarachnoid hemorrhages without cortical contusions or intracerebral or intraventricular hemorrhages; and (3) no pulmonary abnormalities. Sub-lethal dcBI was associated with: (1) apnea lasting up to 15?sec, with transient abnormalities in oxygen saturation; (2) very few delayed deaths; (3) subarachnoid hemorrhages, especially in the path of the blast wave; (4) abnormal immunolabeling for IgG, cleaved caspase-3, and ?-amyloid precursor protein (?-APP), and staining for Fluoro-Jade C, all in deep brain regions away from the subarachnoid hemorrhages, but in the path of the blast wave; and (5) abnormalities on the accelerating Rotarod that persisted for the 1 week period of observation. We conclude that exposure of the head alone to severe explosive blast predisposes to significant neurological dysfunction. PMID:21639724

Kuehn, Reed; Simard, Philippe F; Driscoll, Ian; Keledjian, Kaspar; Ivanova, Svetlana; Tosun, Cigdem; Williams, Alicia; Bochicchio, Grant; Gerzanich, Volodymyr; Simard, J Marc

2011-10-01

249

Stress pulse phenomena  

SciTech Connect

This paper is an introductory discussion of stress pulse phenomena in simple solids and fluids. Stress pulse phenomena is a very rich and complex field that has been studied by many scientists and engineers. This paper describes the behavior of stress pulses in idealized materials. Inviscid fluids and simple solids are realistic enough to illustrate the basic behavior of stress pulses. Sections 2 through 8 deal with the behavior of pressure pulses. Pressure is best thought of as the average stress at a point. Section 9 deals with shear stresses which are most important in studying solids.

McGlaun, M.

1993-08-01

250

Imaging of snapping phenomena.  

PubMed

Snapping phenomena result from the sudden impingement between anatomical and/or heterotopical structures with subsequent abrupt movement and noise. Snaps are variously perceived by patients, from mild discomfort to significant pain requiring surgical management. Identifying the precise cause of snaps may be challenging when no abnormality is encountered on routinely performed static examinations. In this regard, dynamic imaging techniques have been developed over time, with various degrees of success. This review encompasses the main features of each imaging technique and proposes an overview of the main snapping phenomena in the musculoskeletal system. PMID:22744321

Guillin, R; Marchand, A J; Roux, A; Niederberger, E; Duvauferrier, R

2012-10-01

251

30 CFR 816.66 - Use of explosives: Blasting signs, warnings, and access control.  

Code of Federal Regulations, 2013 CFR

...Blasting signs, warnings, and access control. 816.66 Section 816.66...Blasting signs, warnings, and access control. (a) Blasting signs. Blasting...the blasting schedule. (c) Access control. Access within the...

2013-07-01

252

Explosive signatures: Pre & post blast  

NASA Astrophysics Data System (ADS)

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 microhardness testing respectively.

Bernier, Evan Thomas

253

Blast-related fracture patterns: a forensic biomechanical approach  

PubMed Central

Improved protective measures and medical care has increased the survivability from battlefield injuries. In an attempt to reduce the debilitating consequences of blast injury, understanding and mitigating the effects of explosion on the extremities is key. In this study, forensic biomechanical analyses have been applied to determine mechanisms of injury after the traumatic event. The aims of this study were (i) to determine which effects of the explosion are responsible for combat casualty extremity bone injury in two distinct environments, namely open, free-field (open group), and in vehicle or in cover (enclosed group), and (ii) to determine whether patterns of combat casualty bone injury differed between environments. Medical records of casualties admitted to a military hospital in Afghanistan were reviewed over a six-month period. Explosive injuries have been sub-divided traditionally into primary, secondary and tertiary effects. All radiographs were independently reviewed by a military radiologist, a team of military orthopaedic surgeons and a team of academic biomechanists, in order to determine ‘zones of injury’ (ZoIs), and their related mechanisms. Sixty-two combat casualties with 115 ZoIs were identified. Thirty-four casualties in the open group sustained 56 ZoIs; 28 casualties in the enclosed group sustained 59 ZoIs. There was no statistical difference in mean ZoIs per casualty between groups (p = 0.54). There was a higher proportion of lower limb injuries in the enclosed group compared with the open group (p < 0.05). Of the casualties in the open group, 1 ZoI was owing to the primary effects of blast, 10 owing to a combination of primary and secondary blast effects, 23 owing to secondary blast effects and 24 owing to tertiary blast effects. In contrast, tertiary blast effects predominated in the enclosed group, accounting for 96 per cent of ZoIs. These data clearly demonstrate two distinct injury groups based upon the casualties' environment. The enclosed environment appears to attenuate the primary and secondary effects of the explosion. However, tertiary blast effects were the predominant mechanism of injury, with severe axial loading to the lower extremity being a characteristic of the fractures seen. The development of future mitigation strategies must focus on reducing all explosion-related injury mechanisms. Integral to this process is an urgent requirement to better understand the behaviour of bone in this unique environment.

Ramasamy, Arul; Hill, Adam M.; Masouros, Spyros; Gibb, Iain; Bull, Anthony M. J.; Clasper, Jon C.

2011-01-01

254

Reactive Blast Waves from Composite Charges  

SciTech Connect

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/resolve reaction zones. Numerical simulations of the explosion fields from 1.5-g and 10-kg composite charges were performed. Computed pressure histories (red curve) are compared with measured waveforms (black curves) in Fig. 1. Comparison of these results with a waveform for a non-combustion case in nitrogen (blue curve) demonstrates that a reactive blast wave was formed. Cross-sectional views of the temperature field at various times are presented in Fig. 2, which shows that the flow is turbulent. Initially, combustion occurs at the fuel-air interface, and the energy release rate is controlled by the rate of turbulent mixing. Eventually, oxidizer becomes distributed throughout the cloud via ballistic mixing of the particles with air; energy release then occurs in a distributed combustion mode, and Al particle kinetics controls the energy release rate. Details of the Heterogeneous Continuum Model and results of the numerical simulations of composite charge explosions will be described in the paper.

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

2009-10-16

255

Anorectal injury in pelvic blast.  

PubMed

The signature injury of the Afghanistan campaign has, amongst other things, included an increased incidence of destructive anorectal injury. There is no significant body of evidence about this type of injury on which to base management strategies. This review examines the historical military data, later civilian reports, many of which have challenged the military dogmas of Vietnam, and the spartan contemporaneous military data which does not particularly address pelviperineal blast injury. There is no evidence to support a move away from the doctrine of the four D's (diversion, distal washout, drainage and direct repair), but sound surgical judgement remains the mainstay of managing these challenging and highly morbid injuries. PMID:23631323

Brogden, Tom G; Garner, J P

2013-03-01

256

Nondestructive thermoelectric evaluation of the grit blasting induced effects in metallic biomaterials  

NASA Astrophysics Data System (ADS)

Grit blasting is a surface treatment process widely used to enhance mechanical fixation of the implants through increasing their roughness. Test samples of two metallic biomaterial alloys such 316LVM and Ti6Al4V were blasted by projecting Al2O3 and ZrO2 particles which yield a coarse and a fine rough surface. Then, the blasted samples were thermally treated before and after partial stress relaxation and measured by non-destructive thermoelectric techniques (NDTT), the non-contacting and contacting thermoelectric power (TEP) measurements respectively. It has been found that the TEP measurements are associated directly with the subtle material variations such as cold work and compressive residual stresses due to plastic deformation produced by grit blasting. The TEP measurements clearly demonstrate that the non-contact NDTT technique is very sensitive to the reverse transformation of the ?'-martensite (blasted 316LVM) and the expected relaxation of compressive residual stresses with increasing the severity of the thermal treatment (blasted 316LVM and Ti-6Al-4V), while the contact NDTT results are closely related to grain size refinement and work hardening.

Carreon, H.; Ruiz, A.; Barriuso, S.; González-Carrasco, J. L.; Caballero, F. G.; Lieblich, M.

2013-01-01

257

Mine blast injuries: ocular and social aspects  

PubMed Central

BACKGROUND/AIMS—Landmines have long been used in conventional warfare. These are antipersonnel mines which continue to injure people long after a ceasefire without differentiating between friend or foe, soldier or civilian, women or children. This study focuses on Afghan non-combatants engaged in mine clearing operations in Afghanistan in the aftermath of the Russo-Afghan war. The patterns and types of injuries seen are described and experiences in their management, ways, and means to prevent them, and recommendations for the rehabilitation of the affected individuals are given.?METHODS—It is a retrospective and analytical study of 84 patients aged 19-56 years who sustained mine blast injuries during mine clearing operations in Afghanistan from November 1992 to January 1996. The study was carried out at a military hospital with tertiary care facilities. The patients were divided into three groups on the basis of their injuries. Group 1 required only general surgical attention, group 2 sustained only ocular injuries, while group 3 had combined ocular and general injuries. Patients in groups 2 and 3 were treated in two phases. The first phase aimed at immediate restoration of the anatomy, while restoration of function wherever possible was done in subsequent surgical procedures in the second phase.?RESULTS—It was observed that 51 out of 84 patients (60.7%) had sustained ocular trauma of a variable degree as a result of the blasts. The mean age of the victims was 29 years and they were all male. A total of 91 eyes of 51 patients (89.2%) had been damaged. Bilaterality of damage was seen in 40 (78.4%) patients. Most, 34 (37.3%), eyes became totally blind (NPL). Only a few escaped with injury mild enough not to impair vision. Foreign bodies, small and multiple, were found in the majority of eyes; most, however, were found in the anterior segment, and posterior segment injuries were proportionally less.?CONCLUSIONS—The prevalence of blindness caused by mine blast injuries is quite high. The resulting psychosocial trauma to the patients and their families is tremendous and has not been adequately highlighted. These injuries are a great drain on the country's resources. Enforcement of preventive measures and the use of protective gear and sophisticated equipment by the mine clearing personnel would prove to be far more economical in terms of human life as well as medical and economic resources. There is also need for greater attention towards the establishment of support groups and rehabilitation programmes for these individuals.??

Muzaffar, W.; Khan, M. D.; Akbar, M; Khan, M. D.; Malik, A. M.; Durrani, O.

2000-01-01

258

Isolated primary blast alters neuronal function with minimal cell death in organotypic hippocampal slice cultures.  

PubMed

Abstract An increasing number of U.S. soldiers are diagnosed with traumatic brain injury (TBI) subsequent to exposure to blast. In the field, blast injury biomechanics are highly complex and multi-phasic. The pathobiology caused by exposure to some of these phases in isolation, such as penetrating or inertially driven injuries, has been investigated extensively. However, it is unclear whether the primary component of blast, a shock wave, is capable of causing pathology on its own. Previous in vivo studies in the rodent and pig have demonstrated that it is difficult to deliver a primary blast (i.e., shock wave only) without rapid head accelerations and potentially confounding effects of inertially driven TBI. We have previously developed a well-characterized shock tube and custom in vitro receiver for exposing organotypic hippocampal slice cultures to pure primary blast. In this study, isolated primary blast induced minimal hippocampal cell death (on average, below 14% in any region of interest), even for the most severe blasts tested (424 kPa peak pressure, 2.3 ms overpressure duration, and 248 kPa*ms impulse). In contrast, measures of neuronal function were significantly altered at much lower exposures (336?kPa, 0.84?ms, and 86.5?kPa*ms), indicating that functional changes occur at exposures below the threshold for cell death. This is the first study to investigate a tolerance for primary blast-induced brain cell death in response to a range of blast parameters and demonstrate functional deficits at subthreshold exposures for cell death. PMID:24558968

Effgen, Gwen B; Vogel, Edward W; Lynch, Kimberly A; Lobel, Ayelet; Hue, Christopher D; Meaney, David F; Bass, Cameron R Dale; Morrison, Barclay

2014-07-01

259

Zinc recovery from blast furnace flue dust  

Microsoft Academic Search

Blast furnace flue dusts are a mixture of oxides expelled from the top of the blast furnace, whose major components are iron oxides. They also contain zinc, silicon, magnesium and other minor element oxides in lesser amounts. The direct recycling of flue dust is not usually possible since it contains some undesirable elements (zinc and alkaline metals) that can cause

B. Asadi Zeydabadi; D. Mowla; M. H. Shariat; J. Fathi Kalajahi

1997-01-01

260

Blast furnace coal injection in China  

SciTech Connect

The development of blast furnace coal injection in China will be summarized. The improvements in the technical process for pneumatic conveying, injection feed control, distribution and combustion of pulverized coal will be covered. Ideas are also described concerning the use of oxy-coal technology in a blast furnace.

Zhou, J.G. (Ministry of Metallurgical Industry, Beijing (China). Central Iron and Steel Research Inst.)

1994-09-01

261

30 CFR 75.1323 - Blasting circuits.  

Code of Federal Regulations, 2013 CFR

... (h) Uninsulated connections in each blasting circuit shall be kept out of water and shall not contact the coal, roof, ribs, or floor. (i) When 20 or fewer boreholes are fired in a round, the blasting circuit shall be wired in a single...

2013-07-01

262

Shock sensitivity of blasting explosive cartridges  

Microsoft Academic Search

The undersand variable gap–initiator test was applied to most Japanese blasting explosive cartridges and found useful as the sensitivity test for the cartridges. The recent Japanese watergel and emulsion explosives were shown to be more shock–sensitive than previous ones. The blast noise in the undersand explosion was shown to decrease when the depth of sand cover the cartridge was increased.

Yuji Wada; Hideo Yabashi; Masamitsu Tamura; Tadao Yoshida; Toshio Matsuzawa; Fumio Hosoya

1991-01-01

263

Color changing photonic crystals detect blast exposure.  

PubMed

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

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

2011-01-01

264

Spraengning mot Kompakterat Berg (Confined Volume Blasting),  

National Technical Information Service (NTIS)

SveDeFo has performed halfscale tests with confined volume blasting in LKAB:s mine in Malmberget in order to find out if that gives an improvement in fragmentation. The answer is yes. The fragmentation is better in confined volume blasting compared to ord...

M. Olsson

1987-01-01

265

Highly concentrated foam formulation for blast mitigation  

DOEpatents

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.

Tucker, Mark D. (Albuquerque, NM) [Albuquerque, NM; Gao, Huizhen (Albuquerque, NM) [Albuquerque, NM

2010-12-14

266

Building BLAST for Coprocessor Accelerators Using Macah  

Microsoft Academic Search

Abstract The problem of detecting similarities between different genetic sequences is fun- damental to many,research pursuits in biology and genetics. BLAST (Basic Local Alignment and Search Tool) is the most commonly,used tool for identi- fying and assessing the significance of such similarities. With the quantity of available genetic sequence data rapidly increasing, improving the performance of the BLAST algorithm is

Ben Weintraub

267

Transport phenomena in nanofluidics  

Microsoft Academic Search

The transport of fluid in and around nanometer-sized objects with at least one characteristic dimension below 100nm enables the occurrence of phenomena that are impossible at bigger length scales. This research field was only recently termed nanofluidics, but it has deep roots in science and technology. Nanofluidics has experienced considerable growth in recent years, as is confirmed by significant scientific

Reto B. Schoch; Jongyoon Han; Philippe Renaud

2008-01-01

268

CFD simulation of blasting dust for the design of physical barriers  

Microsoft Academic Search

A computational fluid dynamics (CFD) model has been developed to simulate the dispersion of dust generated in blasting located\\u000a in limestone quarries. This is a complex phenomenon that has been studied through the use of several digital video recordings\\u000a of blasts and dust concentration field measurements by ‘light scattering’ dust collectors. In addition, the subsequent simulation\\u000a of the dispersion of

Susana Torno; Javier Toraño; Mario Menéndez; Malcolm Gent

269

Dynamic fragmentation of blast mitigants  

NASA Astrophysics Data System (ADS)

Experimental evidence from a wide range of sources shows that the expanding cloud of explosively disseminated material comprises “particles” or fragments which have different dimensions from those associated with the original material. Powders and liquids have often been used to surround explosives to act as blast mitigants, and this is the main driver for our research. There are also many other areas of interest where an initially intact material surrounding an explosive charge is dynamically fragmented into a distribution of fragment sizes. Examples of such areas include fuel air explosives and enhanced blast explosives as well as quasi-static pressure mitigation systems, and our studies are thus also relevant to these applications. In this paper, we consider the processes occurring as an explosive interacts with a surrounding layer of liquid or powder and identify why it is important to model these processes as a multiphase material problem as opposed to a single phase, single material velocity problem. We shall present results from this class of numerical modelling. In this paper we shall explore what determines the particle or fragment size distribution resulting from explosive dissemination of a layer of material and discuss reasons why clouds from disseminated liquids and powders look similar. We shall support our analysis with results from recent explosives trials and introduce early results from some ongoing small scale explosive mitigation experiments.

Milne, A. M.; Parrish, C.; Worland, I.

2010-02-01

270

Study of blast event propagation in different media using a novel ultrafast miniature optical pressure sensor  

NASA Astrophysics Data System (ADS)

Traumatic brain injury (TBI, also called intracranial injury) is a high potential threat to our soldiers. A helmet structural health monitoring system can be effectively used to study the effects of ballistic/blast events on the helmet and human skull to prevent soldiers from TBI. However, one of the biggest challenges lies in that the pressure sensor installed inside the helmet system must be fast enough to capture the blast wave during the transient period. In this paper, an ultrafast optical fiber sensor is presented to measure the blast signal. The sensor is based on a Fabry-Pérot (FP) interferometeric principle. An FP cavity is built between the endface of an etched optical fiber tip and the silica thin diaphragm attached on the end of a multimode optical fiber. The sensor is small enough to be installed in different locations of a helmet to measure blast pressure simultaneously. Several groups of tests regarding multi-layer blast events were conducted to evaluate the sensors' performance. The sensors were mounted in different segments of a shock tube side by side with the reference sensors, to measure a rapidly increasing pressure. The segments of the shock tube were filled with different media. The results demonstrated that our sensors' responses agreed well with those from the electrical reference sensors. In addition, the home-made shock tube could provide a good resource to study the propagation of blast event in different media.

Zou, Xiaotian; Wu, Nan; Tian, Ye; Zhang, Hongtao; Niezrecki, Christopher; Wang, Xingwei

2011-05-01

271

Stability of the blast wave in ideal gas  

NASA Astrophysics Data System (ADS)

Stability of a point blast wave in an ideal gas is considered in the case when the initial gas density0 is a power function of radius r:0~r-k . We use a technique previously used in /1,2,3/. Small non-radial blast wave perturbations are expanded to spherical harmonics components of expansion being represented in a self-similar form. The cases of a constant initial gas density and of one being power function of radius are considered. Instability region on n- plane (herestands for a gas specific heat ratio and n stands for a harmonic number) is determined in all cases (k=0 - 12) considered. Critical values of c determining the blast wave stability are calculated. The results are calculated numerically in the general case of arbitrary , n and analytically in some special cases: n=1, n>>1, and -1<<1. The considered cases are modeling supernova explosion /4/ as well as simulating astrophysical phenomena in laboratory experiments /5/. REFERENCES 1. V.M.Ktitorov, Voprosy Atomnoi Nauki i Tekhniki, Ser.Teoreticheskaya i Prikladnaya.Fizika (Atomic Science and Technique Issues, Ser. Theoretical and Applied Physics), No2, p.28, (1984); 2. D.Ryu and E.T.Vishniac, Astrophys.J. 313, 820 (1987); 3. V.M.Ktitorov, Khimicheskaya Fizika (Chemical Physics Issues) V.14, No 2-3, p.169, (1995); 4. R.P.Drake et al., Physics of Plasma, V.8, No 5, p.1804, (2001); 5. R.G.Chevalier, Astrophys.J. 259, p.302 (1982);

Ktitorov, V.

272

Quarter-scale close-in blast-loading experiments in support of the planned contained firing facility  

SciTech Connect

In anticipation of increasingly stringent environmental regulations, Lawrence Livermore National Laboratory is proposing to construct a 60-kg firing chamber to provide blast-effects containment for most of its open-air, high-explosive, firing operations. Even though the Laboratory`s operations are within current environmental limits, containment of the blast effects and hazardous debris will drastically reduce emissions to the environment and minimize the generated hazardous waste. One of the main design considerations is the extremely close-in (Z = 0.66 ft/lb{sup l/3}) blast loading on the reinforced concrete ff the chamber. Historically, floor damage due to close-in loading has been a common problem for other blast chambers within the US Department of Energy and Department of Defense (DOE/DoD). Blast-effects testing and computer analysis were conducted on a replica quarter-scale model of the preliminary floor design. Nineteen blast tests ranging from scaled distances of 1.14 ft/lb{sup l/3} (25%) to 0.57ft/lb{sup 1/3} (200%) were performed on the strain-gaged floor model. In response to predicted and measured failures at the 25% level, various state-of-the-art blast attenuation systems were quickly developed and tested. The most effective blast-attenuation system provided a significant improvement by reducing the measured floor stresses to acceptable levels while minimizing, by its reusability, the impact on the environment.

Pastrnak, J.W.; Baker, C.F.; Simmons, L.F.

1994-07-27

273

CONSERVING ENERGY IN BLAST FREEZERS USING VARIABLE FREQUENCY DRIVES  

Microsoft Academic Search

A stationary blast freezer processing 22-lb cartons of sardines in 19,000 pound lots was modified to improve efficiency and to conserve energy. Baffles were first added to produce uniform air flow. Maximum measured freeze times of 12.6 hours fell to 10.5 hours; total electrical energy savings was estimated to be 12%. A Variable Frequency Drive (VFD) was then installed to

Edward Kolbe; Qingyue Ling; Greg Wheeler

274

Serum-Based Protein Biomarkers in Blast-Induced Traumatic Brain Injury Spectrum Disorder  

PubMed Central

The biological consequences of exposure to explosive blast are extremely complex. Serum protein biomarkers in blast-induced traumatic brain injury (bTBI) can aid in determining injury severity, monitoring progress, and predicting outcome. Exposure to blast results in varying degrees of physical injury. Explosive blast can also induce psychological stress that can contribute to or amplify the extent of physical damage. Given the complexity, scale of injury, and variety of symptoms, bTBI may be best described as a spectrum disorder. In this focused review, we summarize the status of serum protein biomarkers in bTBI in the context of the classification and pathological changes of other forms of TBI. Finally, we recommend specific and easily implementable measures to accelerate serum protein biomarker discovery and validation in bTBI.

Agoston, Denes V.; Elsayed, Mohammad

2012-01-01

275

A review of engineering control technology for exposures generated during abrasive blasting operations.  

PubMed

This literature review presents information on measures for controlling worker exposure to toxic airborne contaminants generated during abrasive blasting operations occurring primarily in the construction industry. The exposures of concern include respirable crystalline silica, lead, chromates, and other toxic metals. Unfortunately, silica sand continues to be widely used in the United States as an abrasive blasting medium, resulting in high exposures to operators and surrounding personnel. Recently, several alternative abrasives have emerged as potential substitutes for sand, but they seem to be underused Some of these abrasives may pose additional metal exposure hazards. In addition, several new and improved technologies offer promise for reducing or eliminating exposures; these include wet abrasive blasting, high-pressure water jetting, vacuum blasting, and automated/robotic systems. More research, particularly field studies, is needed to evaluate control interventions in this important and hazardous operation. PMID:15631059

Flynn, Michael R; Susi, Pam

2004-10-01

276

High resolution imaging of colliding blast waves in cluster media  

NASA Astrophysics Data System (ADS)

Strong shocks and blast wave collisions are commonly observed features in astrophysical objects such as nebulae and supernova remnants. Numerical simulations often underpin our understanding of these complex systems, however modelling of such extreme phenomena remains challenging, particularly so for the case of radiative or colliding shocks. This highlights the need for well-characterized laboratory experiments both to guide physical insight and to provide robust data for code benchmarking. Creating a sufficiently high-energy-density gas medium for conducting scaled laboratory astrophysics experiments has historically been problematic, but the unique ability of atomic cluster gases to efficiently couple to intense pulses of laser light now enables table top scale (1 J input energy) studies to be conducted at gas densities of >1019 particles cm-3 with an initial energy density >5 × 109 J g-1. By laser heating atomic cluster gas media we can launch strong (up to Mach 55) shocks in a range of geometries, with and without radiative precursors. These systems have been probed with a range of optical and interferometric diagnostics in order to retrieve electron density profiles and blast wave trajectories. Colliding cylindrical shock systems have also been studied, however the strongly asymmetric density profiles and radial and longitudinal mass flow that result demand a more complex diagnostic technique based on tomographic phase reconstruction. We have used the 3D magnetoresistive hydrocode GORGON to model these systems and to highlight interesting features such as the formation of a Mach stem for further study.

Smith, Roland A.; Lazarus, James; Hohenberger, Matthias; Marocchino, Alberto; Robinson, Joseph S.; Chittenden, Jeremy P.; Moore, Alastair S.; Gumbrell, Edward T.; Dunne, Mike

2007-12-01

277

Blood flow multiscale phenomena.  

PubMed

The cardiovascular disease is one of most frequent cause deaths in modern society. The objective of this work is analyse the effect of dynamic vascular geometry (curvature, torsion, bifurcation) and pulsatile blood nature on secondary flow, wall shear stress and platelet deposition. The problem was examined as multi-scale physical phenomena using perturbation analysis and numerical modelling. The secondary flow determined as influence pulsatile pressure, vascular tube time-dependent bending and torsion on the main axial flow. Bifurcation and branching phenomena are analysed experimentally through, blood-like fluid pulsatile flow across elastic rubber-like Y-model model. The problem complex geometry near branching in platelet deposit modelling is resolved numerically as Falker-Skan flow. PMID:17847933

Agi?, Ante; Mijovi?, Budimir; Nikoli?, Tatjana

2007-06-01

278

Lunar transient phenomena  

NASA Astrophysics Data System (ADS)

Lunar transient phenomena (LTP) sightings are classified into five categories: brightenings, darkenings, reddish colorations, bluish colorations, and obscurations. There is evidence that the remaining LTP's are of lunar origin. A substantial number of sightings are independently confirmed. They have been recorded on film and spectrograms, as well as with photoelectric photometers and polarization equipment. It suggested that the LTP's may be gentle outgassings of less-than-volcanic proportions.

Cameron, W. S.

1991-03-01

279

Evidence of disrupted functional connectivity in the brain after combat-related blast injury.  

PubMed

Non-impact blast-related mild traumatic brain injury (mTBI) appears to be present in soldiers returning from deployments to Afghanistan and Iraq. Although mTBI typically results in cognitive deficits that last less than a month, there is evidence that disrupted coordination of brain activity can persist for at least several months following injury (Thatcher et al., 1989, 2001). In the present study we examined whether neural communication may be affected in soldiers months after blast-related mTBI, and whether coordination of neural function is associated with underlying white matter integrity. The investigation included an application of a new time-frequency based method for measuring electroencephalogram (EEG) phase synchronization (Aviyente et al., 2010) as well as fractional anisotropy measures of axonal tracts derived from diffusion tensor imaging (DTI). Nine soldiers who incurred a blast-related mTBI during deployments to Afghanistan or Iraq were compared with eight demographically similar control subjects. Despite an absence of cognitive deficits, the blast-related mTBI group exhibited diminished EEG phase synchrony of lateral frontal sites with contralateral frontal brain regions suggesting diminished interhemispheric coordination of brain activity as a result of blast injury. For blast injured (i.e., blast-related mTBI) soldiers we found that EEG phase synchrony was associated with the structural integrity of white matter tracts of the frontal lobe (left anterior thalamic radiations and the forceps minor including the anterior corpus callosum). Analyses revealed that diminished EEG phase synchrony was not the consequence of combat-stress symptoms (e.g., post-traumatic stress and depression) and commonly prescribed medications. Results provide evidence for poor coordination of frontal neural function after blast injury that may be the consequence of damaged anterior white matter tracts. PMID:20851190

Sponheim, Scott R; McGuire, Kathryn A; Kang, Seung Suk; Davenport, Nicholas D; Aviyente, Selin; Bernat, Edward M; Lim, Kelvin O

2011-01-01

280

Acceleration of Ungapped Extension in Mercury BLAST  

PubMed Central

The amount of biosequence data being produced each year is growing exponentially. Extracting useful information from this massive amount of data efficiently is becoming an increasingly difficult task. There are many available software tools that molecular biologists use for comparing genomic data. This paper focuses on accelerating the most widely used such tool, BLAST. Mercury BLAST takes a streaming approach to the BLAST computation by off loading the performance-critical sections to specialized hardware. This hardware is then used in combination with the processor of the host system to deliver BLAST results in a fraction of the time of the general-purpose processor alone. This paper presents the design of the ungapped extension stage of Mercury BLAST. The architecture of the ungapped extension stage is described along with the context of this stage within the Mercury BLAST system. The design is compact and runs at 100 MHz on available FPGAs, making it an effective and powerful component for accelerating biosequence comparisons. The performance of this stage is 25× that of the standard software distribution, yielding close to 50× performance improvement on the complete BLAST application. The sensitivity is essentially equivalent to that of the standard distribution.

Buhler, Jeremy; Chamberlain, Roger D.

2007-01-01

281

LTC vacuum blasting machine (concrete): Baseline report  

SciTech Connect

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.

NONE

1997-07-31

282

On the Propagation and Interaction of Spherical Blast Waves  

NASA Technical Reports Server (NTRS)

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.

Kandula, Max; Freeman, Robert

2007-01-01

283

Partnering and the WCI blast furnace reline  

SciTech Connect

In 1993, WCI Steel entered into a partnership agreement to perform a blast furnace reline. The reline included a complete rebrick from the tuyere breast to the furnace top including the tapholes. Also included was the replacement of the Paul Wurth top equipment from the receiving hoppers through the gearbox and distribution chute, a skip incline replacement, and installation of tilting runners and a casthouse roof. The bustle pipe and hot blast main were repaired. One stove was also replaced. The reline was accomplished in 36 days, wind to wind, which allowed for 29 days of construction inside the blast furnace proper.

Musolf, D.W. [WCI Steel, Inc., Warren, OH (United States)

1997-11-01

284

Possibilities for intensifying blast-furnace smelting  

Microsoft Academic Search

An article published earlier by I. E. Sperkach and I. F. Kurunov [Metallurg, No. 2 (2005)] presented additional information\\u000a in support of the author’s proposal that blast-furnace smelting practice be changed over to the use of 600 kPa top-gas pressure\\u000a and a high-parameter combination blast (oxygen content up to 42%, natural-gas consumption up to 250 m3\\/ton pig). A blast-furnace complex

G. Yu. Kryachko

2006-01-01

285

Dry media blasting with wheat starch  

NASA Astrophysics Data System (ADS)

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.

Foster, Terry

1995-04-01

286

Diffuse and spatially variable white matter disruptions are associated with blast-related mild traumatic brain injury.  

PubMed

Mild traumatic brain injury (mTBI) due to explosive blast is common among military service members and often associated with long term psychological and cognitive disruptions. Little is known about the neurological effects of blast-related mTBI and whether they differ from those of civilian, non-blast mTBI. Given that brain damage from blasts may be diffuse and heterogeneous, we tested the hypothesis that blast mTBI is associated with subtle white matter disruptions in the brain that are spatially inconsistent across individuals. We used diffusion tensor imaging to examine white matter integrity, as quantified by fractional anisotropy (FA), in a group of American military service members with (n=25) or without (n=33) blast-related mTBI who had been deployed as part of Operation Iraqi Freedom or Operation Enduring Freedom. History of civilian non-blast mTBI was equally common across groups, which enabled testing of both blast and non-blast mTBI effects on measures sensitive to (1) concentrated, spatially consistent (average FA within a region of interest [ROI]), (2) concentrated, spatially variable (number of ROIs with low average FA), and (3) diffuse (number of voxels with low FA) disruptions of white matter integrity. Blast mTBI was associated with a diffuse, global pattern of lower white matter integrity, and this pattern was not affected by previous civilian mTBI. Neither type of mTBI had an effect on the measures sensitive to more concentrated and spatially consistent white matter disruptions. Additionally, individuals with more than one blast mTBI tended to have a larger number of low FA voxels than individuals with a single blast injury. These results indicate that blast mTBI is associated with disrupted integrity of several white matter tracts, and that these disruptions are diluted by averaging across the large number of voxels within an ROI. The reported pattern of effects supports the conclusion that the neurological effects of blast mTBI are diffuse, widespread, and spatially variable. PMID:22040736

Davenport, Nicholas D; Lim, Kelvin O; Armstrong, Michael T; Sponheim, Scott R

2012-02-01

287

Visual hallucinations as release phenomena  

Microsoft Academic Search

Whereas episodic, stereotype hallucinations represent irritative phenomena, analogous to ictal attacks, the continuous, variable hallucinations are interpreted as release phenomena resulting from loss or suppression of the normal visual input. The latter have only limited topical significance.

David G. Cogan

1973-01-01

288

Distribution of blood-brain barrier disruption in primary blast injury.  

PubMed

Traumatic brain injury (TBI) resulting from explosive-related blast overpressure is a topic at the forefront of neurotrauma research. Compromise of the blood-brain barrier (BBB) and other cerebral blood vessel dysfunction is commonly reported in both experimental and clinical studies on blast injury. This study used a rifle primer-driven shock tube to investigate cerebrovascular injury in rats exposed to low-impulse, pure primary blast at three levels of overpressure (145, 232, and 323 kPa) and with three survival times (acute, 24, and 48 h). BBB disruption was quantified immunohistochemically by measuring immunoglobulin G (IgG) extravasation with image analysis techniques. Pure primary blast generated small lesions scattered throughout the brain. The number and size of lesions increased with peak overpressure level, but no significant difference was seen between survival times. Despite laterally directed blast exposure, equal numbers of lesions were found in each hemisphere of the brain. These observations suggest that cerebrovascular injury due to primary blast is distinct from that associated with conventional TBI. PMID:23568152

Yeoh, Stewart; Bell, E David; Monson, Kenneth L

2013-10-01

289

Wolf-Rayet phenomena  

NASA Technical Reports Server (NTRS)

The properties of stars showing Wolf-Rayet phenomena are outlined along with the direction of future work. Emphasis is placed on the characteristics of W-R spectra. Specifically the following topics are covered: the absolute visual magnitudes; the heterogeneity of WN spectra; the existence of transition type spectra and compositions the mass loss rates; and the existence of very luminous and possibly very massive W-R stars. Also, a brief overview of current understanding of the theoretical aspects of stellar evolution and stellar winds and the various scenarios that have been proposed to understand W-R spectra are included.

Conti, P. S.

1982-01-01

290

Fluid dynamics of the 1997 Boxing Day volcanic blast on Montserrat, West Indies  

NASA Astrophysics Data System (ADS)

Directed volcanic blasts are powerful explosions with a significant laterally directed component, which can generate devastating, high-energy pyroclastic density currents (PDCs). Such blasts are an important class of eruptive phenomena, but quantified understanding of their dynamics and effects is still incomplete. Here we use 2-D and 3-D multiparticle thermofluid dynamic flow codes to examine a powerful volcanic blast that occurred on Montserrat in December 1997. On the basis of the simulations, we divide the blast into three phases: an initial burst phase that lasts roughly 5 s and involves rapid expansion of the gas-pyroclast mixture, a gravitational collapse phase that occurs when the erupted material fails to mix with sufficient air to form a buoyant column and thus collapses asymmetrically, and a PDC phase that is dominated by motion parallel to the ground surface and is influenced by topography. We vary key input parameters such as total gas energy and total solid mass to understand their influence on simulations, and we compare the simulations with independent field observations of damage and deposits, demonstrating that the models generally capture important large-scale features of the natural phenomenon. We also examine the 2-D and 3-D model results to estimate the flow Mach number and conclude that the range of damage sustained at villages on Montserrat can be reasonably explained by the spatial and temporal distribution of the dynamic pressure associated with subsonic PDCs.

Esposti Ongaro, T.; Clarke, A. B.; Neri, A.; Voight, B.; Widiwijayanti, C.

2008-03-01

291

Calculation and Analysis of Liquid Holdup in Lower Blast Furnace by Model Experiments  

NASA Astrophysics Data System (ADS)

A hydromechanics experiment on the countercurrent flow of gas and liquid simulating the flow conditions in the lower blast furnace was carried out. A cold model of a packed bed with various packing materials and liquids was used to study the holdup of liquid. Correlations for static holdup, dynamic holdup, and total holdup were obtained. A good agreement was found between the calculated and experimental data. A mathematical model simulating the flow fields was applied to study the effect of liquid holdup in blast furnace. The results of the model calculation show that static holdup is the determinant of the total holdup of molten materials when the blast furnace works in stable condition. The slag phase generally reaches flooding holdup ahead of the hot metal. The radial distribution of gas flow is almost not influenced by the holdup of molten materials, but it has a greater influence on the pressure drop. The size of coke has far greater influence on static holdup than liquid properties does. The study is useful for acquiring a deeper understanding of the complex phenomena in the blast furnace and for determining appropriate operational actions under different production conditions.

Xiong, Wei; Bi, Xue-Gong; Wang, Guo-Qiang; Yang, Fu

2012-06-01

292

Medium-Scale Traveling Ionospheric Disturbances (MSTIDs) resulting from Chelyabinsk Meteor Blast  

NASA Astrophysics Data System (ADS)

A global network of GPS receivers continuously make line-of-sight (LOS) measurements of the total electron content (TEC) of the ionosphere. This TEC measurement data can be analyzed to 'persistently monitor' natural and man-made activity in the atmosphere (such as volcanic eruptions, earthquakes, rocket launches, etc) which propagate into the ionosphere to produce TIDs (Traveling Ionospheric Disturbances). As an example we have analyzed in detail the TIDs resulting from the 15 Feb 2013 Chelyabinsk meteor blast as observed by the Artu GPS receiver site in Arti, Russia close to the event. Seven of the GPS satellite measurements with LOS pierce points within 1000 km of the blast show disturbances. Four of these clearly show VTEC oscillations with ~12 minute periods. The other three show much weaker responses, but their LOS pierce points are far from the blast and their aspects between the geomagnetic field & blast propagation vector are unfavorable (near broadside). By fitting all seven measurements we estimate a propagation speed of ~380 m/s for these medium-scale TIDs. As future 'persistent surveillance' efforts we intend to investigate the observability of man-made activities such as static rocket engine firings in TEC measurements. Analysis of MSTIDs resulting from the Chelyabinsk meteor blast

Sheeks, B. J.; Warren, N.; Coster, A. J.

2013-12-01

293

Perfluorocarbon vapor tagging of blasting cap detonators  

DOEpatents

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.

Dietz, Russell N. (Shoreham, NY); Senum, Gunnar I. (Patchogue, NY)

1981-01-01

294

Improvement of Blasting Techniques in Opencast Mines.  

National Technical Information Service (NTIS)

Experience to date indicates that the most important factors affecting the degree of blasting required are the homogeneity of the hard rocks and their overall thickness, taken together with the amount of regional jointing, stratification fractures and ind...

1987-01-01

295

Simplified simulation of the transient behavior of temperatures in the upper shaft of the blast furnace  

SciTech Connect

The blast furnace is the principal process in the world for production of iron for primary steelmaking. The furnace acts as a huge countercurrent heat exchange and chemical reactor with complicated heat and mass transfer phenomena and chemical reactions. The flows of burden and gas in the blast furnace shaft strongly affect the fuel economy of the process. An optimal gas flow distribution, which is obtained by controlling the burden distribution, leads to a high utilization degree of the reducing gas, smooth burden descent, and little wear of the furnace lining. Here, a one-dimensional dynamic model of the upper part of the blast furnace shaft is applied to study the evolution of gas and burden temperatures, mainly in order to shed light on the transient phenomena after charging dumps of burden. The effects of irregularities in the burden descent and charging are also studied briefly. The simulations demonstrate that the temperatures of the burden layers in the lower part of the simulated region assume a quasi-steady state, indicating that the changes in the top gas temperature experienced immediately after a dump of burden arise primarily because of heat transfer between the gas and the dump. These results support the idea that such temporary changes can be interpreted in terms of distribution of the dumps on the burden surface.

Saxen, H. [Aabo Akademi Univ. (Finland)

1998-06-01

296

Creating successful blast furnace refractory systems  

SciTech Connect

Successful lifetimes of the refractories utilized in the blast furnace are dependent on a variety of external factors such as operation, geometry, cooling capability, configuration and arrangement, as well as refractory properties. These external factors, as well as the properties required to withstand the main mechanisms of wear, combine to create the successful refractory system. These significant factors and properties are reviewed with the intention of providing guidelines required for successful refractory performance in the blast furnace.

Dzermejko, A.J. [UCAR Carbon Co., Inc., Columbia, TN (United States)

1995-07-01

297

Lightweight Energy Absorbers for Blast Containers  

NASA Technical Reports Server (NTRS)

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.

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

2003-01-01

298

Methods for predicting rubble motion during blasting  

SciTech Connect

Recent applications of explosives and blasting agents to rubble rock have led to requirements for more elaborate design and analysis methods. Many in situ extraction techniques require rubblization to take place in a confined region where rock motion is a predominate factor in creating a permeable broken bed. Two analytical methods are presented which describe the large rubble motion during blasting. These methods are intended to provide the blast designer with a tool for evaluation and further refinement of blasting patterns and timing sequences. In both these methods, the rock medium is represented by a series of discrete, discontinuous regions (bodies, masses). The use of discontinuous techniques rather than the classical continuum methods, results in better approximations to the rubble motion. These regions are set in motion by pressure loads from the explosive. The motion of these regions is then calculated numerically using interaction laws between regions in contact. The basis for these models or methods is presented along with the background for selecting explosive pressure loads and rock mass material behavior. Typical examples, including both cratering and bench blasting geometries, are discussed which illustrate the use of these models to predict rubble motion. Such engineering representations appear to provide a practical method for use in predicting rubble motion and a tool for design evaluation of blasting in confined geometries.

Schamaun, J.T.

1984-03-01

299

Ultra Safe And Secure Blasting System  

SciTech Connect

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.

Hart, M M

2009-07-27

300

Pipeline response to blasting in rock  

SciTech Connect

Twenty-one highway construction blasts were used to record pipeline data from production shots that consisted of small explosive arrays with delays among the explosive holes. A 30-in pipe section and a 12-in. pipeline in the vicinity of the highway construction work were instrumented with strain gages. The data provided an opportunity to determine if the estimating equations and techniques developed with soil data could be modified and applied to real world blasting situations in rock. The construction shots were fired in a solid rock area through which trenches for the pipes had been cut, and the pipes installed with a soil and fragmented rock backfill. Maxi pipe stresses induced by the blasts were computed from strains in circumferential and longitudinal directions. Analysis of these stresses and comparisons with soil blasting equations revealed that the single-point source equation provided a realistic upper-bound estimate of max stress to be expected in bench type construction blasting. However, additional work is required in model scale and actual scale experiments. Delays are also discussed. Analysis of ground vibration data was also performed. Several particle velocity prediction equations are reviewed, as well as problems in relating peak particle velocity data to pipe stress data. Use of pipe stress data to develop safe blasting criteria for buried pipelines is advocated instead of traditional peak particle velocity.

Esparza, E.D. (Southwest Research Inst., San Antonio, TX (United States))

1991-09-01

301

A pattern-recognition algorithm of oscillometric BP measurement with primary detection of systolic\\/diastolic arterial pressure from actual physiological phenomena occurred during arm decompression  

Microsoft Academic Search

Potentially high accuracy of BP evaluation by ABPM due to numerous ambulatory measurements is substantially neutralized by insufficient accuracy of automatic measurements. The prevalent oscillometric technique of automatic BP measurements is currently based on abstract algorithms of indirect calculating systolic\\/diastolic pressures from pulse amplitudes using empirical criteria.To create new pattern-recognition algorithm of oscillometric BP measurement based on physical principles of

Stanislav E. Pekarski

2005-01-01

302

Coal and oil mixture injection into blast furnace  

SciTech Connect

The results of the transportation loop tests indicate that the pressure drop of coal oil mixture (COM) in the pipe can be precisely estimated under the condition that the rheological characteristics of COM are determined by a pseudo-plastic fluid model and the apparent viscosity is measured by the cone and plate viscometer. Through the COM combustion test by LBF it was found that 70 to 85% intected fine coal was combustible in the raceway and there was little difference in the gas permeability between COM and oil injection. The replacement ratio of COM to heavy fuel oil was estimated to be about 0.8 to 0.9 by the mathematical blast furnace simulation model. The injection test into three tuyeres of a large commercial blast furnace has been performed with remarkable success since September 1980. The useful results obtained from these test will be reflected to the commercializing injection test into all tuyeres of Kashima No. 1 blast furnace. 36 figures, 1 table.

Yabe, S.; Kurashige, I.; Miyazaki, T.; Iba, T.; Kojima, M.; Kojima, M.; Shoji, Y.; Kamei, Y.

1981-01-01

303

Dust explosion hazards due to blasting of oil shale  

SciTech Connect

The conditions favoring secondary explosions of dust or gas accompanying the blasting of oil shale are the subject of continuing investigation by the Bureau of Mines. In the present study, oil shale dust was dispersed in a gallery and ignited by various blasting agents blown out of a cannon according to a standard testing procedure. Parallel tests were conducted in the Bureau's Experimental Mine to test propagation as well as ignition of oil shale dust. In both gallery and mine, the minimum explosion limits were determined as a function of dust loading, weight and type of blasting agent, and amount of added methane. The results of these experiments are compared with previous measurements using methane-air explosions as an initiation source. In view of recent mine dust sampling data, the main explosion hazard in nongassy oil shale mines is likely to be limited to the region of the face. But in gassy mines, dust-gas explosions could be expected to propagate considerable distances.

Richmond, J.K.; Beitel, F.P.

1984-04-01

304

Reducing the Structural Vulnerability of Food-Processing Plants to the Blast and Thermal Effects of Nuclear Weapons.  

National Technical Information Service (NTIS)

The report studies the reduction of the structural vulnerability of representative food plants in the United States to the blast overpressures and thermal energy released by nuclear weapons. It develops hardening measures for strengthening points or areas...

R. I. Young R. H. Powley

1964-01-01

305

[Study on quantificational analysis method for the non-crystalline content in blast furnace slag].  

PubMed

Quantificational analysis method for the non-crystalline and crystalline contents in blast furnace slag was studied by means of X-ray diffraction. The process of quantificational analysis method includes standard samples preparation, samples preparation, X-ray diffraction measurement and data treatment. The data treatment includes integration areas of non-crystalline curve and crystalline peaks in certain diffraction angle range, linear fitting and quantificational coefficient determination. The preparation methods of standard samples for X-ray diffraction of blast furnace slag were proposed, including 100% crystalline sample and 100% non-crystalline sample. The 100% crystalline sample can be obtained by heating blast furnace slag for 12 h at 1 000-1 200 degrees C, and the 100% non-crystalline sample can be obtained by quenching the molten slag with enough water. The X-ray diffraction method of quantificational analysis of non-crystalline content in blast furnace slag was proposed with the 100% non-crystalline and 100% crystalline standard samples, and the quantificational coefficient can be obtained by linear regression on the integration areas of non-crystalline curve and crystalline peaks of X-ray diffraction in the 2-theta range 20 degrees-40 degrees. This method is suitable for the blast furnace slag with the non-crystalline content over 80%. The non-crystalline and crystalline contents of original blast furnace slag are obtained by combining the X-ray diffraction results and mathematical treatment, and this method is suitable for the blast furnace slag with the non-crystalline content over 90%, whose process includes preparing the 100% crystalline standard sample by heating blast furnace slag for 12 h at 1000-1200 degrees C, samples preparation with the 0.02 interval in the 0-0.1 mass ratio range of 100% crystalline to original slag, X-ray diffraction measurement of the samples prepared and data treatment using iterative linear regression. The quantificational analysis method for blast furnace slag can be applied to various kinds of blast furnace slag from different steel plants. PMID:18479048

Yan, Ding-Liu; Guo, Pei-Min; Qi, Yuan-Hong; Zhang, Chun-Xia; Wang, Hai-Feng; Dai, Xiao-Tian

2008-02-01

306

Weld pool phenomena  

SciTech Connect

During welding, the composition, structure and properties of the welded structure are affected by the interaction of the heat source with the metal. The interaction affects the fluid flow, heat transfer and mass transfer in the weld pool, and the solidification behavior of the weld metal. In recent years, there has been a growing recognition of the importance of the weld pool transport processes and the solid state transformation reactions in determining the composition, structure and properties of the welded structure. The relation between the weld pool transport processes and the composition and structure is reviewed. Recent applications of various solidification theories to welding are examined to understand the special problems of weld metal solidification. The discussion is focussed on the important problems and issues related to weld pool transport phenomena and solidification. Resolution of these problems would be an important step towards a science based control of composition, structure and properties of the weld metal.

David, S.A.; Vitek, J.M.; Zacharia, T. [Oak Ridge National Lab., TN (United States); DebRoy, T. [Pennsylvania State Univ., University Park, PA (United States)

1994-09-01

307

Blast resistance of prismatic sandwich structures  

NASA Astrophysics Data System (ADS)

Metallic sandwich panels have emerged as candidate blast resistant structures that can be tailored to contain damage from impulsive loads of the type typically generated by explosives. When such panels are impulsively loaded, the stresses imposed by the core on the front face, as well as those transmitted through the core, govern the response metrics: especially the center displacement, the resistance to tearing and the loads transmitted to the supports. Prismatic cores such as I-, X-, Y- and Z- cores differ from other cores, such as foams and trusses, in that they do not exhibit constant dynamic crush strength, enabling collapse to occur in a controlled manner. Establishing relationships between core topology crushing response and panel performance is one of the major goals of this research. For this purpose a gas gun instrumented with high speed photography and direct impact Hopkinson pressure bar was built and used to perform laboratory scale high-speed impact tests. Samples of representative prismatic core unit cells were manufactured and tested in compression at axial velocities ranging from quasi-static to 200m/s. The dynamic strength and deformation (buckling) were measured and used to calibrate the imperfections in a finite element model. The model was then used to validate a constitutive model that can be used to predict the blast resistance of prismatic sandwich structures. This research identifies a simple dual level dynamic strength as a common response in metallic prismatic cores. This is due to the dominant effect of plastic shock generated by dynamic loading. Furthermore, it justifies the use of a simple dynamic axial compression test for calibration of the dynamic strength of the core. An analytical model that accounts for the shock effects in a homogenized core and embodies the dual-level dynamic strength is presented. It is shown to capture the experimental observations and simulated results with acceptable fidelity. This model provides the basis for a constitutive model that can be used to understand the response of sandwich plates subject to impulsive loads.

Ferri, Enrico

308

Blast waves from cylindrical charges  

NASA Astrophysics Data System (ADS)

Comparisons of explosives are often carried out using TNT equivalency which is based on data for spherical charges, despite the fact that many explosive charges are not spherical in shape, but cylindrical. Previous work has shown that it is possible to predict the over pressure and impulse from the curved surface of cylindrical charges using simple empirical formulae for the case when the length-to-diameter ( L/ D) ratio is greater or equal to 2/1. In this paper, by examining data for all length-to-diameter ratios, it is shown that it is possible to predict the peak over pressure, P, for any length-to-diameter ratio from the curved side of a bare cylindrical charge of explosive using the equation P=K_PM(L/D)^{1/3}/R^3, where M is the mass of explosive, R the distance from the charge and K_P is an explosive-dependent constant. Further out where the cylindrical blast wave `heals' into a spherical one, the more complex equation P=C_1(Z^' ' })^{-3}+C_2(Z^' ' })^{-2}+C_3(Z^' ' })^{-1} gives a better fit to experimental data, where Z^' ' } = M^{1/3}(L/D)^{1/9}/D and C_1, C_2 and C_3 are explosive-dependent constants. The impulse is found to be independent of the L/ D ratio.

Knock, C.; Davies, N.

2013-07-01

309

Blast Resistance and Damage Modelling of Fibre Metal Laminates to Blast Loads  

NASA Astrophysics Data System (ADS)

A robust and efficient computational model has been developed which is capable of modelling the dynamic non-linear behaviour of GLARE panels subjected to blast loadings. Numerical model validation have been performed considering case studies of GLARE panels subjected to a blast-type pressure pulse for which experimental data on the back-face deflection and post-damage observations were available. Excellent agreement of mid-point deflections and evidence of severe yield line deformation were shown and discussed against the performed blast tests. A further parametric study identified GLARE as a potential blast attenuating structure, exhibiting superior blast potential against monolithic aluminium plates. It was concluded that further work needed to be carried out to take into account the influence of geometry (cylindrical structures), pre-pressurisation effects and boundary conditions

Mohamed, Galal F. A.; Soutis, Costas; Hodzic, Alma

2012-06-01

310

Modelling of blast loading on aboveground structures - II. Internal blast and ground shock  

NASA Astrophysics Data System (ADS)

Recent studies of the nature and structural effects of confined explosions, contact blast and explosion-induced ground shock are presented. High explosive blast is distinguished from that due to a gaseous deflagration. The effects of confinement and venting are considered in the evaluation of dynamic loads. Maxima for the initial internal blast pressure can be estimated from the scaled blast data or theoretical analyses of normal blast wave reflection from a rigid wall. Semi-empirical relations and prediction methods for gas pressures for many types of internal explosions including high explosives, gas mixtures and dust suspensions are given on the basis of pseudo-static character. The loading of a contact explosion and the associated effects on a concrete target are determined as functions of charge weight, concrete strength and member thickness. In the final part, the evaluation of both airblast-induced ground shock and directly transmitted motion are included in simple form without considering the soil-structure interaction.

Beshara, F. B. A.

1994-06-01

311

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

NASA Astrophysics Data System (ADS)

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.

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

2011-08-01

312

High explosive testing of a corrugated metal blast shelter with membrane blast doors  

SciTech Connect

In October 1983 the Defense Nuclear Agency (DNA) sponsored a high-explosive blast test, nicknamed DIRECT COURSE. This event simulated the blast effects from a one-kiloton nuclear detonation and provided an environment for the testing of selected blast and fallout shelters for their structural integrity. Under work for the Federal Emergency Management Agency (FEMA), the Oak Ridge National Laboratory (ORNL) fielded a set of experiments at the DIRECT COURSE event which were directed toward reducing the cost of blast shelter for small groups of people, such as workers in critical industries (keyworkers). Six items were tested: three scale models of a corrugated metal blast shelter and three full-size blast door closures for such a shelter. The three shelters survived blast overpressures up to 2.55 MPa (225 psi), a level which is equivalent to being approximately 800 m (0.5 mile) from a 1 megaton nuclear detonation. Each shelter model was 180 cm (6 ft.) long by 60 cm (2 ft.) in diameter, was buried about 60 cm (2 ft.) below ground level, and represented a 1/4-scale version of a full-size blast shelter which would be capable of supporting 12 to 18 occupants. The three full-size, 90 cm (35 in.) diameter, blast doors for such a shelter also successfully resisted the same range of blast overpressure. Each door weighed less than 45 kg (100 lb) and incorporated a novel, yielding-membrane design. These sheet metal membranes were between 1.3 and 2.0 mm (0.050 and 0.080 in.) thick and were supported by an edge beam (hoop).

Zimmerman, G.P.; Chester, C.V.

1984-12-01

313

30 CFR 817.66 - Use of explosives: Blasting signs, warnings, and access control.  

Code of Federal Regulations, 2013 CFR

...Blasting signs, warnings, and access control. 817.66 Section 817.66...Blasting signs, warnings, and access control. (a) Blasting signs. Blasting...in § 817.64(a). (c) Access control. Access within the...

2013-07-01

314

30 CFR 57.6404 - Separation of blasting circuits from power source.  

Code of Federal Regulations, 2013 CFR

...false Separation of blasting circuits from power source. 57...NONMETAL MINES Explosives Electric Blasting-Surface and Underground...6404 Separation of blasting circuits from power source. (a...power source to a blasting circuit shall be locked in the...

2013-07-01

315

30 CFR 56.6404 - Separation of blasting circuits from power source.  

Code of Federal Regulations, 2013 CFR

... Separation of blasting circuits from power source. 56...NONMETAL MINES Explosives Electric Blasting § 56.6404 Separation of blasting circuits from power source. ...power source to a blasting circuit shall be locked in...

2013-07-01

316

Comprehensive report to Congress: Clean Coal Technology Program: Blast furnace granulated coal injection system demonstration project: A project proposed by: Bethlehem Steel Corporation  

SciTech Connect

Bethlehem Steel Corporation (BSC), of Bethlehem, Pennsylvania, has requested financial assistance from DOE for the design, construction, and operation of a 2800-ton-per-day blast furnace granulated coal injection (BFGCI) system for each of two existing iron-making blast furnaces. The blast furnaces are located at BSC's facilities in Burns Harbor, Indiana. BFGCI technology involves injecting coal directly into an iron-making blast furnace and subsequently reduces the need for coke on approximately a pound of coke for pound of coal basis. BFGCI also increases blast furnace production. Coke will be replaced with direct coal injection at a rate of up to 400 pounds per NTHM. The reducing environment of the blast furnace enables all of the sulfur in the coal to be captured by the slag and hot metal. The gases exiting the blast furnace are cleaned by cyclones and then wet scrubbing to remove particulates. The cleaned blast furnace gas is then used as a fuel in plant processes. There is no measurable sulfur in the off gas. The primary environmental benefits derived from blast furnace coal injection result from the reduction of coke requirements for iron making. Reduced coke production will result in reduced releases of environmental contaminants from coking operations. 5 figs.

Not Available

1990-10-01

317

Simple Phenomena, Slow Motion, Surprising Physics  

ERIC Educational Resources Information Center

This article describes a few simple experiments that are worthwhile for slow motion recording and analysis either because of interesting phenomena that can be seen only when slowed down significantly or because of the ability to do precise time measurements. The experiments described in this article are quite commonly done in Czech schools. All…

Koupil, Jan; Vicha, Vladimir

2011-01-01

318

Operation Teapot, Nevada Test Site, February-May 1955. Project 33. 2. The effects of noise in blast-resistant shelters  

Microsoft Academic Search

A fatigue syndrome was observed to develop in animals that experience a nuclear explosion while confined in a blast-resistant shelter. In order to determine the importance of noise as a contributing factor, groups of deafened and nondeafened albino male rats were placed in blast-resistant shelters on two explosions of the Operation Teapot series. Noise measurements were made which showed that

F. G. Hirsch; Longhurst; D. R. McGiboney; H. H. Sander

1956-01-01

319

Characterization of blasted austenitic stainless steel and its corrosion resistance  

NASA Astrophysics Data System (ADS)

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.

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

2003-12-01

320

Operation Teapot, Nevada Test Site, February-May 1955. Project 39. 4b. Technical photography (high speed-blast biology)  

Microsoft Academic Search

The purpose of this project was to provide the photographic requirements for Civil Effects Test Group projects concerned with the biological phenomena of blast. Preshot and postshot photographs were obtained of animals and\\/or structures. High-speed motion picture sequences of group-shelter interiors containing animals were attempted. Medical photographs of gross specimens were obtained at the time of autopsy of experimental animals.

M. A. Palmer; R. S. Harper

1955-01-01

321

Wolf-Rayet phenomena  

NASA Technical Reports Server (NTRS)

An outline is presented of what is currently known about the properties of stars showing Wolf-Rayet (W-R) phenomena, taking into account also the directions in which future work is leading. W-R spectra are found to be primarily an emission line spectrum superimposed on a 'hot' continuous spectrum. P Cygni absorption components are observed for some lines in some stars. A fact not realized when Thomas (1968) discussed W-R spectra is that a very few W-R stars have intrinsic absorption lines. On the basis of the spectroscopic observations, it could now be inferred that an optically thick stellar wind is involved. Many of the WN subtypes do contain some carbon. The WC subtypes contain little or no nitrogen. Attention is given to absolute visual magnitudes of W-R stars, the heterogeneity of W-R spectra, transition W-R spectra, mass loss rates, very luminous W-R objects, theoretical aspects of stellar structure and stellar winds, and evolutionary scenarios.

Conti, P. S.

1982-01-01

322

On Detecting Transient Phenomena  

NASA Astrophysics Data System (ADS)

Transient phenomena are interesting and potentially highly revealing of details about the processes under observation and study that could otherwise go unnoticed. It is therefore important to maximize the sensitivity of the method used to identify such events. In this article, we present a general procedure based on the use of the likelihood function for identifying transients which is particularly suited for real-time applications because it requires no grouping or pre-processing of the data. The method makes use of all the information that is available in the data throughout the statistical decision-making process, and is suitable for a wide range of applications. Here we consider those most common in astrophysics, which involve searching for transient sources, events or features in images, time series, energy spectra, and power spectra, and demonstrate the use of the method in the case of a weak X-ray flare in a time series and a short-lived quasi-periodic oscillation in a power spectrum. We derive a fit statistic that is ideal for fitting arbitrarily shaped models to a power density distribution, which is of general interest in all applications involving periodogram analysis.

Bélanger, G.

2013-08-01

323

Numerical simulations of near-field blast effects using kinetic plates  

NASA Astrophysics Data System (ADS)

Numerical simulations using two hydrocodes were compared to near-field measurements of blast impulse associated with ideal and non-ideal explosives to gain insight into testing results and predict untested configurations. The recently developed kinetic plate test was designed to measure blast impulse in the near-field by firing spherical charges in close range from steel plates and probing plate acceleration using laser velocimetry. Plate velocities for ideal, non-ideal and aluminized explosives tests were modeled using a three dimensional hydrocode. The effects of inert additives in the explosive formulation were modeled using a 1-D hydrocode with multiphase flow capability using Lagrangian particles. The relative effect of particle impact on the plate compared to the blast wave impulse is determined and modeling is compared to free field pressure results.

Neuscamman, S. J.; Manner, V. W.; Brown, G. W.; Glascoe, L. G.

2014-05-01

324

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

325

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

326

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

327

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

328

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

329

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

330

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

331

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

332

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

333

DETAIL VIEW OF BLAST FURNACE NO. 3 AREA BELOW BUSTLE ...  

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

DETAIL VIEW OF BLAST FURNACE NO. 3 AREA BELOW BUSTLE PIPE, CINDER NOTCH IN CENTER, SLAG RUNNER IN FOREGROUND. - Pittsburgh Steel Company, Monessen Works, Blast Furnace No. 3, Donner Avenue, Monessen, Westmoreland County, PA

334

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

335

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

336

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

337

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

338

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

339

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

340

High Precision Analysis of Blast Events on Highway Bridges.  

National Technical Information Service (NTIS)

There has been increased awareness about safety of highway bridges from intentional/unintentional blast loads. This report focuses on the investigation of behavior of various bridge components during blast loads through a high fidelity finite element mode...

A. K. Agrawal Z. Yi

2008-01-01

341

Blast Tests of Expedient Shelters in the DICE THROW Event.  

National Technical Information Service (NTIS)

To determine the worst blast environments that eight types of expedient shelters can withstand, the authors subjected a total of 18 shelters to the 1-kiloton blast effects of Defense Nuclear Agency's DICE THROW main event. These expedient shelters include...

C. H. Kearny, C. V. Chester

1978-01-01

342

30 CFR 56.6605 - Isolation of blasting circuits.  

Code of Federal Regulations, 2013 CFR

...STANDARDS-SURFACE METAL AND NONMETAL MINES Explosives Extraneous Electricity § 56.6605 Isolation of blasting circuits. Lead...tracks, and shall be protected from sources of stray or static electricity. Blasting circuits shall be protected from any...

2013-07-01

343

Enhancements and Analysis of CTH Software for Underbody Blast.  

National Technical Information Service (NTIS)

Accurate tools and procedures for simulating the blast effects of shallow buried explosive devices are critical to the Department of Defense's efforts to design blast-resistant vehicles that can increase crew survivability and counter the threat from impr...

C. Moore R. Thyagarajan R. Weed

2013-01-01

344

Mine Roof Vibrations from Production Blasts, Shullsburg Mine, Shullsburg, Wis.  

National Technical Information Service (NTIS)

The Bureau of Mines recorded both particle accelerations and velocities from one-stick and production blasts at Eagle-Picher Industries' Shullsburg mine, Shullsburg, Wis., to test the effectiveness of square root scaling in grouping underground blast vibr...

D. E. Fogelson J. J. Olson L. R. Fletcher R. A. Dick

1970-01-01

345

Paint removal using wheat starch blast media  

NASA Astrophysics Data System (ADS)

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.

Foster, Terry; Oestreich, John

1993-03-01

346

Single Pass Streaming BLAST on FPGAs*†  

PubMed Central

Approximate string matching is fundamental to bioinformatics and has been the subject of numerous FPGA acceleration studies. We address issues with respect to FPGA implementations of both BLAST- and dynamic-programming- (DP) based methods. Our primary contribution is a new algorithm for emulating the seeding and extension phases of BLAST. This operates in a single pass through a database at streaming rate, and with no preprocessing other than loading the query string. Moreover, it emulates parameters turned to maximum possible sensitivity with no slowdown. While current DP-based methods also operate at streaming rate, generating results can be cumbersome. We address this with a new structure for data extraction. We present results from several implementations showing order of magnitude acceleration over serial reference code. A simple extension assures compatibility with NCBI BLAST.

Herbordt, Martin C.; Model, Josh; Sukhwani, Bharat; Gu, Yongfeng; VanCourt, Tom

2008-01-01

347

Application of Infrared-Attenuated Total Reflection Technique Combined with Sedimentation Phenomena to Particle Size Measurement: Fundamental Experiments on Applicability of the Method  

NASA Astrophysics Data System (ADS)

A new method using infrared attenuated total reflection (IR-ATR) spectroscopy and sedimentation of particles in a suspension was proposed for particle size measurement. The time dependence of the IR-ATR signal intensity for mono-size dispersed particles agreed qualitatively with the theoretical expectation. Content analyses of samples containing dispersed particles of two sizes gave values close to actual ones. The possibility of size distribution analysis was shown.

Sarno, B. J.; Yoshidome, T.; Ikuta, Y.; Rabor, J. B.; Tsurumura, Y.; Montecillo, M. E.; Higo, M.

2013-09-01

348

Hydrocortisone in culture protects the blast cells in acute myeloblastic leukemia from the lethal effects of cytosine arabinoside  

SciTech Connect

The blast cells in acute myeloblastic leukemia (AML) respond to many of the same regulatory mechanisms that control normal hemopoiesis. These include the growth factors that bind to membrane receptors and steroid hormones or vitamins that have intracellular receptors. The authors report the effects in culture of the steroid glucocorticoid hydrocortisone on freshly explanted AML blasts from patients and on two continuous AML cell lines. Only small changes in clonogenic cell numbers in suspension cultures were seen in the presence of hydrocortisone. The most striking effect of the hormone was on the sensitivity of blasts cells to cytosine arabinoside (ara-C). In contrast to the response of AML blast cells to retinoic acid, a ligand for intracellular steroid receptors that sensitizes some blast populations to ara-C, hydrocortisone reduced the toxic effects of the drug. The protective action of hydrocortisone was not mediated through the cell cycle since exposure of blasts to hydrocortisone did not affect the percentage of cells in DNA synthesis as measured with the tritiated thymidine (3HTdR) suicide technique. The hydrocortisone effect could be demonstrated using a pulse (20 min) exposure protocol. Blasts pulsed with increasing specific activities of 3HTdR showed the usual response pattern with an initial loss in plating efficiency to about 50% of control, followed by a plateau, regardless of whether the cells had been exposed to hydrocortisone. Control blasts exposed to increasing ara-C concentrations gave very similar dose-response curves; in striking contrast, blast cells cultured in hydrocortisone, then pulsed with ara-C did not lose colony-forming ability even though the same population was sensitive to 3HTdR.

Yang, G.S.; Wang, C.; Minkin, S.; Minden, M.D.; McCulloch, E.A. (Ontario Cancer Institute, University of Toronto (Canada))

1991-07-01

349

Characterization of blasted austenitic stainless steel and its corrosion resistance  

Microsoft Academic Search

It is known that the corrosion resistance of stainless steel is deteriorated by blasting, but the reason for this deterioration\\u000a is not clear. A blasted austenitic stainless steel plate (JIS-SUS304) has been characterized with comparison to the scraped\\u000a and non-blasted specimens. The surface roughness of the blasted specimen is larger than that of materials finished with #180\\u000a paper. A martensite

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

2003-01-01

350

Prediction of depth removal in leather surface grit blasting using neural networks and Box-Behnken design of experiments  

Microsoft Academic Search

In this work, leather material is for the first time prepared by grit blasting process in order to improve peel strength when\\u000a bonding. Peel tests show that it is the surface depth of removal rather than surface roughness that dominates the bonding\\u000a performance. Therefore, measurement of surface removal is critical for surface preparation of using a grit blasting process.\\u000a Indirect

Zhongxu Hu; Robert Bicker; Chris Marshall

2007-01-01

351

Resolving Localisation Phenomena  

NASA Astrophysics Data System (ADS)

Realistic numerical models of the Earth's crust and lithosphere require consitutive models which account for brittle/semi-brittle deformation. These are typically nonlinear, and produce localisation phenomena (e.g. faults, shear bands). The presence of a fault can cause variations in the deformation field over a length of the order of the fault / fault-zone thickness ?. Depending on the overall scale of the numerical model (global or regional), the interpretation of the fault thickness may vary, however it is typically the feature with the smallest length scale in the system. In order to accurately compute the stress and strain rate from our numerical models, we must ensure that we resolve shear bands to the point where characteristic patterns no longer change with resolution. This means using a discretisation which can resolve length scales of size ?. This is computationally difficult as the location of the shear band are not predefined. Furthermore, the length scale ? is typically several orders of magnitude smaller than the size of the domain. We have developed a numerical scheme suitable for modelling crustal/lithosphere deformation which dynamically modifies the spatial resolution in the vicinity of shear bands. The method comprises a mixed eulerian/lagrangian approach employing both finite elements and moving material points. Adaptivity at the grid and material point level is introduced using techniques from the nonlinear, adaptive finite elements. By combining standard element based error estimators and recovery techniques we can obtain continuous solutions for u_i, p and ?ij which are accurate to within a specified tolerance though out the entire domain. We show that the optimal rate of convergence is obtained for all fields and illustrate the effectiveness of the adaptive material point method via some simple localisation problems.

May, D.; Moresi, L.

2006-12-01

352

Everyday Phenomena and Teachers' Training.  

ERIC Educational Resources Information Center

Investigated the ability of Swedish student teachers to explain everyday phenomena in science education, asking all fourth-term student teachers about phenomena where transformations of matter were involved. Analysis of students' written answers indicates that there is a great need in teacher training to work with conceptual understanding and with…

Eskilsson, Olle; Holgersson, Ingemar

1999-01-01

353

BlastSim — Multi agent simulation of suicide bombing  

Microsoft Academic Search

This paper introduces BlastSim - physics based stationary multi-agent simulation of blast waves and its impact on human body. The agents are constrained by physical characteristics and mechanics of blast wave. The simulation is capable of assessing the impact of crowd formation patterns on the magnitude of injury and number of casualties during a suicide bombing attack. It also examines

Zeeshan-ul-hassan Usmani; Fawzi A. Alghamdi; Daniel Kirk

2009-01-01

354

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

355

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

356

Proceedings of the twelfth conference on explosives and blasting techniques  

SciTech Connect

This book presents the papers given at a conference on the use of explosive fracturing to construct underground energy facilities. Topics considered at the conference included the Atomic Energy of Canada Limited's underground research laboratory, drilling and blasting techniques for canals, pipeline trenches, blasting costs, underground coal mining, presplitting of granite, energy consumption, and overburden blasting vibrations.

Konya, C.J.

1986-01-01

357

Abrasive Blasting Agents: Designing Studies to Evaluate Relative Risk  

Microsoft Academic Search

Workers exposed to respirable crystalline silica used in abrasive blasting are at increased risk of developing a debilitating and often fatal fibrotic lung disease called silicosis. The National Institute for Occupational Safety and Health (NIOSH) recommends that silica sand be prohibited as abrasive blasting material and that less hazardous materials be used in blasting operations. However, data are needed on

Ann Hubbs; Mark Greskevitch; Eileen Kuempel; Fernando Suarez; Mark Toraason

2005-01-01

358

Note: A table-top blast driven shock tube  

Microsoft Academic Search

The prevalence of blast-induced traumatic brain injury in conflicts in Iraq and Afghanistan has motivated laboratory scale experiments on biomedical effects of blast waves and studies of blast wave transmission properties of various materials in hopes of improving armor design to mitigate these injuries. This paper describes the design and performance of a table-top shock tube that is more convenient

Michael W. Courtney; Amy C. Courtney

2010-01-01

359

Coupled rock motion and gas flow modeling in blasting  

Microsoft Academic Search

The spherical element computer code DMC (Distinct Motion Code) used to model rock motion resulting from blasting has been enhanced to allow routine computer simulations of bench blasting. The enhancements required for bench blast simulation include: (1) modifying the gas flow portion of DMC, (2) adding a new explosive gas equation of state capability, (3) modifying the porosity calculation, and

D. S. Preece; S. D. Knudsen

1991-01-01

360

Simulation of blasting induced rock motion using spherical element models  

Microsoft Academic Search

Control of the rock motion associated with blasting can have significant economic benefits. For example, surface coal mining can be made more efficient if the overburden material can be cast further with explosives, leaving less work for mechanical equipment. The final muck pile shape in very type of surface and underground blasting is controlled by the blasting induced motion of

L. M. Taylor; D. S. Preece; NM Albuquerque

1989-01-01

361

Development of automatic temperature control system in blast furnace  

Microsoft Academic Search

In this paper, we consider automatic temperature control system which is the most important part in blast furnace operation. In general, automatic temperature control for blast furnace is very difficult and sensitive because it is affected by a number of factors. So firstly, this paper describes temperature control model for blast furnace by using Takagi-Sugeno (TS) fuzzy model based on

Woosung Choi; Woojong Yoo; Sangchul Won

2006-01-01

362

Marker assisted selection for the control of rice blast disease  

Microsoft Academic Search

techniques, plant breeders have developed a number of blast resistant cultivars adapted to different rice growing regions worldwide. However, the rice industry remains threatened by blast disease because of the instability of the rice blast fungus. Recent advances in rice genomics provides additional tools for plant breeders to develop rice production systems that could be environmentally benign. This article outlines

Yulin Jia; Dale Bumpers

2003-01-01

363

The Role of Family Phenomena in Posttraumatic Stress in Youth  

PubMed Central

Topic Youth face trauma that can cause posttraumatic stress (PTS). Purpose 1). To identify the family phenomena used in youth PTS research; and 2). Critically examine the research findings regarding the relationship between family phenomena and youth PTS. Sources Systematic literature review in PsycInfo, PILOTS, CINAHL, and MEDLINE. Twenty-six empirical articles met inclusion criteria. Conclusion Measurement of family phenomena included family functioning, support, environment, expressiveness, relationships, cohesion, communication, satisfaction, life events related to family, parental style of influence, and parental bonding. Few studies gave clear conceptualization of family or family phenomena. Empirical findings from the 26 studies indicate inconsistent empirical relationships between family phenomena and youth PTS, though a majority of the prospective studies support a relationship between family phenomena and youth PTS. Future directions for leadership by psychiatric nurses in this area of research and practice are recommended.

Deatrick, Janet A.

2010-01-01

364

Blood-brain barrier dysfunction after primary blast injury in vitro.  

PubMed

The incidence of blast-induced traumatic brain injury (bTBI) has increased substantially in recent military conflicts. However, the consequences of bTBI on the blood-brain barrier (BBB), a specialized cerebrovascular structure essential for brain homeostasis, remain unknown. In this study, we utilized a shock tube driven by compressed gas to generate operationally relevant, ideal pressure profiles consistent with improvised explosive devices (IEDs). By multiple measures, the barrier function of an in vitro BBB model was disrupted following exposure to a range of controlled blast loading conditions. Trans-endothelial electrical resistance (TEER) decreased acutely in a dose-dependent manner that was most strongly correlated with impulse, as opposed to peak overpressure or duration. Significantly increased hydraulic conductivity and solute permeability post-injury further confirmed acute alterations in barrier function. Compromised ZO-1 immunostaining identified a structural basis for BBB breakdown. After blast exposure, TEER remained significantly depressed 2 days post-injury, followed by spontaneous recovery to pre-injury control levels at day 3. This study is the first to report immediate disruption of an in vitro BBB model following primary blast exposure, which may be important for the development of novel helmet designs to help mitigate the effects of blast on the BBB. PMID:23581482

Hue, Christopher D; Cao, Siqi; Haider, Syed F; Vo, Kiet V; Effgen, Gwen B; Vogel, Edward; Panzer, Matthew B; Bass, Cameron R Dale; Meaney, David F; Morrison, Barclay

2013-10-01

365

'Do-it-yourself' fallout/blast shelter evaluation. Final report  

SciTech Connect

Expedient fallout shelters recommended to the general public were evaluated for their potential to provide safety to occupants during nuclear blast. The blast threat was in the 2 to 50 psi overpressure range from a 1 megaton (MT) yield weapon. Research included a literature search for expedient shelter designs and evaluations of the designs to certify their ability to protect occupants. Shelters were evaluated systematically by first analyzing each design for expected failure loads. Next, scale model tests were planned and conducted in the Fort Cronkhite shock tunnel. Structural responses and blast pressures were recorded in a series of twelve experiments involving 96 structural response models. Two rigid models were included in each test to measure internal blast pressure leakage. Probabilities of survival were determined for each of the shelters tested. Expected failure mechanisms were identified for each of the eight U.S. shelters. One shelter, tilt-up doors and earth, was eliminated from consideration because of uncertainties for the associated permanent structure. Failure loads of the remaining seven shelters were determined through analysis. Analyses included failure by overturning/translation, trench collapse, or roof collapse. A car-over-trench shelter was evaluated solely through analysis. The threshold for human tolerance to blast pressures (lung damage) was calculated as 8 psi with a 99 percent survival rate at 28 psi. Thresholds for trench wall stability were calculated based on material strengths and shelter geometries.

Nash, P.T.; Baker, W.E.; Esparza, E.D.; Westine, P.S.; Blaylock, N.W.

1984-03-01

366

Observing Meteors, Comets, Supernovae and other transient Phenomena  

Microsoft Academic Search

Transient phenomena are short-lived astronomical events, unusual in a science in which time is more often measured in millennia than milliseconds. There is a fascination with transient phenomena, predictable or otherwise, that astronomers of all abilities share. In Meteors, Comets, Supernovae, Neil Bone gives guidelines for observers, including the best possible periods (months or years) to see seasonal but unpredictable

Neil Bone

1999-01-01

367

A Mechanism Model for Raceway Formation and Variation in a Blast Furnace  

NASA Astrophysics Data System (ADS)

In this article, a previous mechanical model is extended to predict raceway penetration in a blast furnace (BF) and to dynamically illustrate how raceway penetration varies over time after the blast velocity varies based on Newton's second law. The model is validated by industrial measurements, and more precise predictions have been obtained using the present model. Moreover, the effects of combustion reactions on the raceway shape and size are taken into account in the present model. The mechanism for raceway formation and variation revealed by the present model is as follows: Fast movements of packed bed above a raceway roof due to blast blowing rate variation make raceway size vary rapidly and form its prototype; combustion reactions modify raceway size and shape, and they maintain its stability.

Guo, Jing; Cheng, Shusen; Zhao, Hongbo; Pan, Hongwei; Du, Pengyu; Teng, Zhaojie

2013-06-01

368

Diffusion Tensor Imaging Reveals Acute Subcortical Changes after Mild Blast-Induced Traumatic Brain Injury  

PubMed Central

Mild blast-induced traumatic brain injury (mbTBI) poses special diagnostic challenges due to its overlapping symptomatology with other neuropsychiatric conditions and the lack of objective outcome measures. Diffusion tensor imaging (DTI) can potentially provide clinically relevant information toward a differential diagnosis. In this study, we aimed to determine if single and repeated (5 total; administered on consecutive days) mild blast overpressure exposure results in detectable structural changes in the brain, especially in the hippocampus. Fixed rat brains were analyzed by ex vivo DTI at 2?h and 42 days after blast (or sham) exposure(s). An anatomy-based region of interest analysis revealed significant interactions in axial and radial diffusivity in a number of subcortical structures at 2?h only. Differences between single- and multiple-injured rats were largely in the thalamus but not the hippocampus. Our findings demonstrate the value and the limitations of DTI in providing a better understanding of mbTBI pathobiology.

Kamnaksh, Alaa; Budde, Matthew D.; Kovesdi, Erzsebet; Long, Joseph B.; Frank, Joseph A.; Agoston, Denes V.

2014-01-01

369

Chemical changes of lakes within the Mount St. Helens blast zone  

SciTech Connect

Differences in the dissolved chemistry of lakes devastated by the 18 May 1980 eruption of Mount St. Helens are attributable to location relative to the lateral blast trajectory of the eruption and to the emplacement of mineral deposits. Elemental enrichment ratios of pre- and posteruption measurements for Spirit Lake and comparisons of the chemical concentrations and elemental ratios for lakes inside and outside the blast zone reflect the influences of the dissolution of magmatic and lithic deposits. The pH changes were minor because of buffering by carbonic acid and reactions involving mineral alteration, dissolved organics, and biological processes.

Wissmar, R.C.; Devol, A.H.; Nevissi, A.E.; Sedell, J.R.

1982-01-01

370

The application of cylindrical blast waves to impact studies of materials  

NASA Astrophysics Data System (ADS)

An exploding wire method is described in which the impact properties of hollow polymeric cylinders are investigated by subjecting them to internal, high-pressure, blast wave loading. Studies of the blast waves themselves, and of the expansion of thin-walled polymer tubes and rings, have been made using high-speed image convertor photography at 10 exp 5 to 10 exp 6 frames/s. Such observations, when combined with strain gauge and pressure measurements where necesary, have enabled the mechanical properties of several polymers to be determined at high strain rates from 10 exp 3 to 10 exp 5/s.

Parry, D. J.; Stewardson, H. R.; Ahmad, S. H.; Al-Maliky, N.

1991-04-01

371

BLAST: a more efficient report with usability improvements  

PubMed Central

The Basic Local Alignment Search Tool (BLAST) website at the National Center for Biotechnology (NCBI) is an important resource for searching and aligning sequences. A new BLAST report allows faster loading of alignments, adds navigation aids, allows easy downloading of subject sequences and reports and has improved usability. Here, we describe these improvements to the BLAST report, discuss design decisions, describe other improvements to the search page and database documentation and outline plans for future development. The NCBI BLAST URL is http://blast.ncbi.nlm.nih.gov.

Boratyn, Grzegorz M.; Camacho, Christiam; Cooper, Peter S.; Coulouris, George; Fong, Amelia; Ma, Ning; Madden, Thomas L.; Matten, Wayne T.; McGinnis, Scott D.; Merezhuk, Yuri; Raytselis, Yan; Sayers, Eric W.; Tao, Tao; Ye, Jian; Zaretskaya, Irena

2013-01-01

372

BLAST: a more efficient report with usability improvements.  

PubMed

The Basic Local Alignment Search Tool (BLAST) website at the National Center for Biotechnology (NCBI) is an important resource for searching and aligning sequences. A new BLAST report allows faster loading of alignments, adds navigation aids, allows easy downloading of subject sequences and reports and has improved usability. Here, we describe these improvements to the BLAST report, discuss design decisions, describe other improvements to the search page and database documentation and outline plans for future development. The NCBI BLAST URL is http://blast.ncbi.nlm.nih.gov. PMID:23609542

Boratyn, Grzegorz M; Camacho, Christiam; Cooper, Peter S; Coulouris, George; Fong, Amelia; Ma, Ning; Madden, Thomas L; Matten, Wayne T; McGinnis, Scott D; Merezhuk, Yuri; Raytselis, Yan; Sayers, Eric W; Tao, Tao; Ye, Jian; Zaretskaya, Irena

2013-07-01

373

Advanced MRI in Blast-related TBI.  

National Technical Information Service (NTIS)

The purpose of the research effort was to test two advanced MRI methods, DTI and resting-state fMRI, in active-duty military blast-related TBI patients acutely after injury and correlate findings with TBI-related clinical outcomes 6-12 months later. The g...

D. L. Brody

2012-01-01

374

New trends in drilling and blasting technology  

Microsoft Academic Search

The mining industry is poised on the threshold of some exciting opportunities. It has been realized that the unit operations such as drilling, blasting, excavation, loading, hauling and crushing are interrelated variables in the total cost equation. The development, advancement and utilization of the innovative technologies are very important for the mining industry to be cost effective. In order to

S. P. Singh

2000-01-01

375

Cloth Ballistic Vest Alters Response to Blast,  

National Technical Information Service (NTIS)

Ballistic wounds have been and will remain the principal cause of casualties in combat. Cloth ballistic vests (CBV) play an important role in limiting critical wounds from fragments and small arms fire. There is an increased risk of primary blast injury o...

D. R. Richmond J. T. Yelverton T. G. Mundie Y. Y. Phillips

1988-01-01

376

People Interview: Solar physics blasts into space  

NASA Astrophysics Data System (ADS)

INTERVIEW Solar physics blasts into space Lucie Green's physics and astrophysics degree has taken her to the Crimea to study binary stars and to the Mullard Space Science Laboratory. David Smith talks to her about her career as a solar physicist and her involvement in outreach activities.

2010-09-01

377

Blast resistance of prismatic sandwich structures  

Microsoft Academic Search

Metallic sandwich panels have emerged as candidate blast resistant structures that can be tailored to contain damage from impulsive loads of the type typically generated by explosives. When such panels are impulsively loaded, the stresses imposed by the core on the front face, as well as those transmitted through the core, govern the response metrics: especially the center displacement, the

Enrico Ferri

2009-01-01

378

Behavior of suspended roofs under blast loading  

Microsoft Academic Search

This work deals with the nonlinear dynamic behavior of initially imperfect dissipative multi-suspended roof systems under blast loading. For various realistic combinations of geometrical, stiffness and damping parameters, the systems do not experience either snapping or large amplitude chaotic motions, contrary to findings reported for single and double suspension roof systems. A nonlinear analysis is employed to establish that global

Ioannis G. Raftoyiannis; Constantine C. Spyrakos; George T. Michaltsos

2007-01-01

379

Novel model to investigate blast injury in the central nervous system.  

PubMed

Blast-induced neurotrauma (BINT) is a common injury modality associated with the current war efforts and increasing levels of terrorist activity. Exposure to the primary blast wave generated by explosive devices causes significant neurological deficits and is responsible for many of the war-related pathologies. Despite research efforts, the mechanism of injury is still poorly understood. To this end, we have established a novel ex vivo model for the direct observation and quantification of BINT at the tissue level. The model provides a quantifiable and reproducible method to illustrate the mechanism of BINT. Isolated sections of guinea pig spinal cord white matter were exposed to a supersonic shockwave using a blast generator with small-scaled explosives. The blast wave impact with isolated tissue was observed using focused shadowgraphy with a high-speed camera recording at 90,000 fps. Concurrently, functional deficits were measured by monitoring the production of compound action potentials using a double sucrose gap-recording chamber. Additionally, anatomical deficits were measured after blast exposure with a dye exclusion assay to visualize axonal membrane permeability. Our findings demonstrate that direct exposure to the blast wave compressed nervous tissue at a rate of 60 m/sec and led to significant functional deficits. Damage to the isolated spinal cord was marked by increased axonal permeability, suggesting rapid compression from the shockwave-generated high strain rates that resulted in membrane disruption. The model provides new insight into the mechanism of BINT and permits direct observation that may contribute to the development of appropriate treatment regimens. PMID:21529318

Connell, Sean; Gao, Jian; Chen, Jun; Shi, Riyi

2011-07-01

380

Modeling coal combustion behavior in an ironmaking blast furnace raceway: model development and applications  

SciTech Connect

A numerical model has been developed and validated for the investigation of coal combustion phenomena under blast furnace operating conditions. The model is fully three-dimensional, with a broad capacity to analyze significant operational and equipment design changes. The model was used in a number of studies, including: Effect of cooling gas type in coaxial lance arrangements. It was found that oxygen cooling improves coal burnout by 7% compared with natural gas cooling under conditions that have the same amount of oxygen enrichment in the hot blast. Effect of coal particle size distribution. It was found that during two similar periods of operation at Port Kembla's BF6, a difference in PCI capability could be attributed to the difference in coal size distribution. Effect of longer tuyeres. Longer tuyeres were installed at Port Kembla's BF5, leading to its reline scheduled for March 2009. The model predicted an increase in blast velocity at the tuyere nose due to the combustion of volatiles within the tuyere, with implications for tuyere pressure drop and PCI capability. Effect of lance tip geometry. A number of alternate designs were studied, with the best-performing designs promoting the dispersion of the coal particles. It was also found that the base case design promoted size segregation of the coal particles, forcing smaller coal particles to one side of the plume, leaving larger coal particles on the other side. 11 refs., 15 figs., 4 tabs.

Maldonado, D.; Austin, P.R.; Zulli, P.; Guo B. [BlueScope Steel Research Laboratories, Port Kembla, NSW (Australia)

2009-03-15

381

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

SciTech Connect

In their Contributed Article, Nyein et al. (1,2) present numerical simulations of blast waves interacting with a helmeted head and conclude that a face shield may significantly mitigate blast induced traumatic brain injury (TBI). A face shield may indeed be important for future military helmets, but the authors derive their conclusions from a much smaller explosion than typically experienced on the battlefield. The blast from the 3.16 gm TNT charge of (1) has the following approximate peak overpressures, positive phase durations, and incident impulses (3): 10 atm, 0.25 ms, and 3.9 psi-ms at the front of the head (14 cm from charge), and 1.4 atm, 0.32 ms, and 1.7 psi-ms at the back of a typical 20 cm head (34 cm from charge). The peak pressure of the wave decreases by a factor of 7 as it traverses the head. The blast conditions are at the threshold for injury at the front of the head, but well below threshold at the back of the head (4). The blast traverses the head in 0.3 ms, roughly equal to the positive phase duration of the blast. Therefore, when the blast reaches the back of the head, near ambient conditions exist at the front. Because the headform is so close to the charge, it experiences a wave with significant curvature. By contrast, a realistic blast from a 2.2 kg TNT charge ({approx} an uncased 105 mm artillery round) is fatal at an overpressure of 10 atm (4). For an injury level (4) similar to (1), a 2.2 kg charge has the following approximate peak overpressures, positive phase durations, and incident impulses (3): 2.1 atm, 2.3 ms, and 18 psi-ms at the front of the head (250 cm from charge), and 1.8 atm, 2.5 ms, and 16.8 psi-ms at the back of the head (270 cm from charge). The peak pressure decreases by only a factor of 1.2 as it traverses the head. Because the 0.36 ms traversal time is much smaller than the positive phase duration, pressures on the head become relatively uniform when the blast reaches the back of the head. The larger standoff implies 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).

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

2011-01-21

382

Patterns in Blast Injuries to the Hand  

PubMed Central

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.

Buntic, Rudolf F.; Brooks, Darrell

2008-01-01

383

Batch Blast Extractor: an automated blastx parser application  

PubMed Central

Motivation BLAST programs are very efficient in finding similarities for sequences. However for large datasets such as ESTs, manual extraction of the information from the batch BLAST output is needed. This can be time consuming, insufficient, and inaccurate. Therefore implementation of a parser application would be extremely useful in extracting information from BLAST outputs. Results We have developed a java application, Batch Blast Extractor, with a user friendly graphical interface to extract information from BLAST output. The application generates a tab delimited text file that can be easily imported into any statistical package such as Excel or SPSS for further analysis. For each BLAST hit, the program obtains and saves the essential features from the BLAST output file that would allow further analysis. The program was written in Java and therefore is OS independent. It works on both Windows and Linux OS with java 1.4 and higher. It is freely available from:

Pirooznia, Mehdi; Perkins, Edward J; Deng, Youping

2008-01-01

384

A computational model of blast loading on the human eye.  

PubMed

Ocular injuries from blast have increased in recent wars, but the injury mechanism associated with the primary blast wave is unknown. We employ a three-dimensional fluid-structure interaction computational model to understand the stresses and deformations incurred by the globe due to blast overpressure. Our numerical results demonstrate that the blast wave reflections off the facial features around the eye increase the pressure loading on and around the eye. The blast wave produces asymmetric loading on the eye, which causes globe distortion. The deformation response of the globe under blast loading was evaluated, and regions of high stresses and strains inside the globe were identified. Our numerical results show that the blast loading results in globe distortion and large deviatoric stresses in the sclera. These large deviatoric stresses may be indicator for the risk of interfacial failure between the tissues of the sclera and the orbit. PMID:23591604

Bhardwaj, Rajneesh; Ziegler, Kimberly; Seo, Jung Hee; Ramesh, K T; Nguyen, Thao D

2014-01-01

385

LTC American`s, Inc. vacuum blasting machine: Baseline report  

SciTech Connect

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.

NONE

1997-07-31

386

The Experimental Study of the Blast from Bombs and Bare Charges  

Microsoft Academic Search

The paper gives an account of investigations on the blast from bare and cased charges of explosive ranging in weight from a few pounds to several thousand pounds. The measuring technique, involving the use of piezo-electric gauges with cathoderay oscillographs, is described, and features of theoretical interest or of practical importance are illustrated. It is shown that, at any rate

G. Grime; H. Sheard

1946-01-01

387

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

NASA Astrophysics Data System (ADS)

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.

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

2013-03-01

388

Blast testing of expedient shelters in model scale  

SciTech Connect

A research program was conducted to evaluate the blast resistance of expedient fallout shelters designed for the civilian population in the event of a nuclear attack. As part of this research, model-size shelters of six different designs were tested in a shock tunnel at average overpressure levels of 2.8, 4.6, and 8.8 psi. Measurements of the external blast pressures and internal pressure leakage into the model shelters were made. The expedient shelters tested utilize, in general, shallow soil excavation, load-bearing members of timber or doors, and soil-covered roofs. Replica model sizes were selected so that the shock tunnel load durations were long enough to test in the quasi-static load realm. Some of the shelter designs survived at every overpressure level very well, while other tests items suffered structural failures in almost every case. This paper presents a brief description of the experiments, including some details of the shelters, of the model fabrication and pressure measurement system, and a summary of the results.

Esparza, E.D.

1986-08-01

389

Review of methods to attenuate shock/blast waves  

NASA Astrophysics Data System (ADS)

Quick and reliable shock wave attenuation is the goal of every protection facility and therefore it is not surprising that achieving this has drawn much attention during the past hundred years. Different options have been suggested; their usefulness varying from a reasonable protection to the opposite, a shock enhancement. An example for a suggestion for shock mitigation that turned out to be an enhancement of the impinging shock wave was the idea to cover a protected object with a foam layer. While the pressure behind the reflected shock wave from the foam frontal surface was smaller than that recorded in a similar reflection from a rigid wall [25], the pressure on the “protected” surface, attached to the foam's rear-surface, was significantly higher than that recorded in a similar reflection from a bare, rigid wall [11]. In protecting humans and installations from destructive shock and/or blast waves the prime goal is to reduce the wave amplitude and the rate of pressure increase across the wave front. Both measures result in reducing the wave harmful effects. During the past six decades several approaches for achieving the desired protection have been offered in the open literature. We point out in this review that while some of the suggestions offered are practical, others are impractical. In our discussion we focus on recent schemes for shock/blast wave attenuation, characterized by the availability of reliable measurements (notably pressure and optical diagnostics) as well as high-resolution numerical simulations.

Igra, O.; Falcovitz, J.; Houas, L.; Jourdan, G.

2013-04-01

390

Quantum phenomena in semiconductor structures  

NASA Astrophysics Data System (ADS)

The research investigated the electronic properties of small semiconductor devices where transport is dominated or affected by quantum phenomena. Topics investigated included small silicon MOS transistors. Here it is shown that large, intrinsic, stresses affect transport in the two dimensional inversion layer. As the stress is at the edge of the device, it is not significant for larger structures. The electron-phonon interaction in epitaxial layers of GaAs has been investigated using Schottky gate FETs (MESFETs). It is shown that the nature and interpretation of magnetophonon oscillations is strongly affected by the geometry of the sample. Studies of small samples were extended to one dimensional GaAs-AlGaAs heterojunctions where it was shown that varying the width at low temperatures resulted in large random conductance fluctuations. These were fitted to the appropriate theory. Quantum corrections to the conductivity and Hall effect were investigated in a range of III-V semiconductors, and, in a new development, a technique of electrostatic squeezing was developed to investigate quantum interference in a ring of electron gas in a GaAs-AlGaAs heterojunction. A description is given of measurements and analysis of electronic transport in MBE grown InSb.

Pepper, M.

1988-12-01

391

Ordering Phenomena in Undercooled Alloys  

SciTech Connect

Much of the work performed under this grant was devoted to using modern ideas in kinetics to understand atom movements in metallic alloys far from thermodynamic equilibrium. Kinetics arguments were based explicitly on the vacancy mechanism for atom movements. The emphasis was on how individual atom movements are influenced by the local chemical environment of the moving atom, and how atom movements cause changes in the local chemical environments. The author formulated a kinetic master equation method to treat atom movements on a crystal lattice with a vacancy mechanism. Some of these analyses [3,10,16] are as detailed as any treatment of the statistical kinetics of atom movements in crystalline alloys. Three results came from this work. Chronologically they were (1) A recognition that tracking time dependencies is not necessarily the best way to study kinetic phenomena. If multiple order parameters can be measured in a material, the ''kinetic path'' through the space spanned by these order parameters maybe just as informative about the chemical factors that affect atom movements [2,3,5-7,9-11,14-16,18,19,21,23,24,26,36,37]. (2) Kinetic paths need not follow the steepest gradient of the free energy function (this should be well-known), and for alloys far from equilibrium the free energy function can be almost useless in describing kinetic behavior. This is why the third result surprised me. (3) In cluster approximations with multiple order parameters, saddle points are common features of free energy functions. Interestingly, kinetic processes stall or change time scale when the kinetic path approaches a state at a saddle point in the free energy function, even though these states exist far from thermodynamic equilibrium. The author calls such a state a ''pseudostable'' (falsely stable) state [6,21,26]. I have also studied these phenomena by more ''exact'' Monte Carlo simulations. The kinetic paths showed features similar to those found in analytical theories. The author found that a microstructure with interfaces arranged in space as a periodic minimal surface is a probably an alloy at a saddle point in its free energy function [21,26,37].

Fultz, Brent

1997-07-17

392

Planar blast scaling with condensed-phase explosives in a shock tube  

SciTech Connect

Blast waves are strong shock waves that result from large power density deposition into a fluid. The rapid energy release of high-explosive (HE) detonation provides sufficiently high power density for blast wave generation. Often it is desirable to quantify the energy released by such an event and to determine that energy relative to other reference explosives to derive an explosive-equivalence value. In this study, we use condensed-phase explosives to drive a blast wave in a shock tube. The explosive material and quantity were varied to produce blast waves of differing strengths. Pressure transducers at varying lengths measured the post-shock pressure, shock-wave arrival time and sidewall impulse associated with each test. Blast-scaling concepts in a one-dimensional geometry were then used to both determine the energy release associated with each test and to verify the scaling of the shock position versus time, overpressure versus distance, and impulse. Most blast scaling measurements to-date have been performed in a three-dimensional geometry such as a blast arena. Testing in a three-dimensional geometry can be challenging, however, as spherical shock-wave symmetry is required for good measurements. Additionally, the spherical wave strength decays rapidly with distance and it can be necessary to utilize larger (several kg) quantities of explosive to prevent significant decay from occurring before an idealized blast wave has formed. Such a mode of testing can be expensive, require large quantities of explosive, and be limited by both atmospheric conditions (such as rain) and by noise complaints from the population density near the test arena. Testing is possible in more compact geometries, however. Non-planar blast waves can be formed into a quasi-planar shape by confining the shock diffraction with the walls of a shock tube. Regardless of the initial form, the wave shape will begin to approximate a planar front after successive wave reflections from the tube walls. Such a technique has previously been used to obtain blast scaling measurements in the planar geometry with gaseous explosives and the condensed-phase explosive nitroguanidine. Recently, there has been much interest in the blast characterization of various non-ideal high explosive (NIHE) materials. With non-ideals, the detonation reaction zone is significantly larger (up to several cm for ANFO) than more ideal explosives. Wave curvature, induced by charge-geometry, can significantly affect the energy release associated with NIHEs. To measure maximum NIHE energy release accurately, it is desirable to minimize any such curvature and, if possible, to overdrive the detonation shock to ensure completion of chemical reactions ahead of the sonic locus associated with the reaction zone. This is achieved in the current study through use of a powerful booster HE and a charge geometry consisting of short cylindrical lengths of NIHE initiated along the charge centerline.

Jackson, Scott L [Los Alamos National Laboratory

2011-01-25

393

Saturation phenomena in LIF measurements, appendix B  

NASA Technical Reports Server (NTRS)

Optical saturation is the phenomenon in which the laser-induced rates of absorption and spontaneous emission between two levels, induced by a laser, become comparable to or greater than the spontaneous emission and collision rates connecting these levels. This results in the excited state population N(u) acquiring a value of similar magnitude to that of the ground state, N(e). Under these conditions the observed fluorescence signal, which is proportional to N(u), is no longer linearly dependent on laser intensity I, but increases at a slower rate, and in principle ultimately becomes independent of I. A conceptual picture of optical saturation using a two-level picture is described. This is, however, inadequate for the description of a real experiment involving a molecule, such as OH, for several reasons, which will be explained briefly; these are the multi-level nature of the electronic states and energy transfer among them and effects due to spatial, spectral, and temporal fluctuations in the laser pulse.

1984-01-01

394

Droplet Breakup Mechanisms in Air-blast Atomizers  

NASA Astrophysics Data System (ADS)

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.

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

2011-11-01

395

Spike morphology in blast-wave-driven instability experiments  

SciTech Connect

The laboratory experiments described in the present paper observe the blast-wave-driven Rayleigh-Taylor instability with three-dimensional (3D) initial conditions. About 5 kJ of energy from the Omega laser creates conditions similar to those of the He-H interface during the explosion phase of a supernova. The experimental target is a 150 {mu}m thick plastic disk followed by a low-density foam. The plastic piece has an embedded, 3D perturbation. The basic structure of the pattern is two orthogonal sine waves where each sine wave has an amplitude of 2.5 {mu}m and a wavelength of 71 {mu}m. In some experiments, an additional wavelength is added to explore the interaction of modes. In experiments with 3D initial conditions the spike morphology differs from what has been observed in other Rayleigh-Taylor experiments and simulations. Under certain conditions, experimental radiographs show some mass extending from the interface to the shock front. Current simulations show neither the spike morphology nor the spike penetration observed in the experiments. The amount of mass reaching the shock front is analyzed and potential causes for the spike morphology and the spikes reaching the shock are discussed. One such hypothesis is that these phenomena may be caused by magnetic pressure, generated by an azimuthal magnetic field produced by the plasma dynamics.

Kuranz, C. C.; Drake, R. P.; Grosskopf, M. J.; Fryxell, B.; Budde, A. [Department of Atmospheric, Oceanic and Space Science, Center for Radiative Shock Hydrodynamics, University of Michigan, 2455 Hayward Street, Ann Arbor, Michigan 48109 (United States); Hansen, J. F.; Miles, A. R. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94550 (United States); Plewa, T. [Department of Scientific Computing, Florida State University, 400 Dirac Science Library, Tallahassee, Florida 32306 (United States); Hearn, N. [Center for Astrophysical Thermonuclear Flashes, University of Chicago, 5640 South Ellis Avenue, Chicago, Illinois 60637 (United States); Knauer, J. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States)

2010-05-15

396

Pilot plant testing of Illinois coal for blast furnace injection. Quarterly report, 1 December 1994--28 February 1995  

SciTech Connect

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 Illinois coal in the blast furnace injection process in a new and unique pilot plant test facility. 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 is 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 1993--94 period. It is intended to complete the study already underway with the Armco and Inland steel companies and to demonstrate quantitatively the suitability of both the Herrin No. 6 and Springfield No. 5 coals for blast furnace injection. The main feature of the current work is the testing of Illinois coals at CANMET`s (Canadian Centre for Mineral and Energy Technology) pilot plant coal combustion facility. This facility simulates blowpipe-tuyere conditions in an operating blast furnace, including blast temperature (900{degrees}C), flow pattern (hot velocity 200 m/s), geometry, gas composition, coal injection velocity (34 m/s) and residence time (20 ms). The facility is fully instrumented to measure air flow rate, air temperature, temperature in the reactor, wall temperature, preheater coil temperature and flue gas analysis. During this quarter there were two major accomplishments.

Crelling, J.C.

1995-12-31

397

Functional status after blast-plus-impact complex concussive traumatic brain injury in evacuated United States military personnel.  

PubMed

Fundamental questions remain unanswered about the longitudinal impact of blast-plus-impact complex traumatic brain injuries (TBI) from wars in Iraq and Afghanistan. This prospective, observational study investigated measures of clinical outcome in US military personnel evacuated to Landstuhl Regional Medical Center (LRMC) in Germany after such "blast-plus" concussive TBIs. Glasgow Outcome Scale-Extended assessments completed 6-12 months after injury indicated a moderate overall disability in 41/47 (87%) blast-plus TBI subjects and a substantial but smaller number (11/18, 61%, p=0.018) of demographically similar US military controls without TBI evacuated for other medical reasons. Cognitive function assessed with a neuropsychological test battery was not different between blast-plus TBI subjects and controls; performance of both groups was generally in the normal range. No subject was found to have focal neurological deficits. However, 29/47 (57%) of blast-plus subjects with TBI met all criteria for post-traumatic stress disorder (PTSD) versus 5/18 (28%) of controls (p=0.014). PTSD was highly associated with overall disability; 31/34 patients with PTSD versus 19/31 patients who did not meet full PTSD criteria had moderate to severe disability (p=0.0003). Symptoms of depression were also more severe in the TBI group (p=0.05), and highly correlated with PTSD severity (r=0.86, p<0.0001). Thus, in summary, high rates of PTSD and depression but not cognitive impairment or focal neurological deficits were observed 6-12 months after concussive blast-plus-impact complex TBI. Overall disability was substantially greater than typically reported in civilian non-blast concussive ("mild") patients with TBI, even with polytrauma. The relationship between these clinical outcomes and specific blast-related aspects of brain injuries versus other combat-related factors remains unknown. PMID:24367929

MacDonald, Christine L; Johnson, Ann M; Nelson, Elliot C; Werner, Nicole J; Fang, Raymond; Flaherty, Stephen F; Brody, David L

2014-05-15

398

EUSO: Extreme Universe Space Observatory atmosphere phenomena  

NASA Astrophysics Data System (ADS)

The idea to use the Earth s atmosphere as a natural laboratory for the detection of EECR events, requires establishment of objective criteria to distinguish between these events and other physical phenomena, which demonstrate optical emissions in the spectral interval under interest, 330400 nm. The atmospheric fluorescence and the Cherenkov emission, caused by EECR should be retrieved from measurements performed in the presence of a continuos background nightglow. Selected spectral interval, foreseen to be examined, contains mainly molecular emissions of O2 Herzberg band, 2nd nd positive band of N2 and the 1st negative band of N+ 2 . Their intensities depend on the season, local time, longitude, latitude, solar activity, geomagnetic activity, etc. While the duration of the nightglow is in order of hours, other type optical phenomena: tropospheric lightening and tropospheric/mesospheric interactions (Blue Jets, Red Starters, Sprites, etc.), have much shorter duration down to milliseconds, while the dynamic range of their brightness ranges several orders. We give also attention to the meteoroids, as a particular class of atmospheric phenomena. It should be mentioned that there is a very few information regarding meteoroids spectral properties in UV range. According to recent theories and models, the meteoroids are able to create marked jet-like structures in the atmosphere, exhibiting optical appearance, which could be wrongly interpreted as EECR events. Such error could arise also for the other aforementioned short-lived optical phenomena. Taking into account all this, it is obvious, that the sophisticate laboratory environment requires detailed analysis of the existing experimental and theoretical studies in order to develop appropriate tests to distinguish EERC and other atmospheric phenomena. The present work stress also on the need to develop appropriate radiation transfer model, which could appear useful tool for assessment of the real brightness of the detected fluorescence and Cherenkov emission. Such model will giving us the possibility to evaluate the energy of the

Kostadinov, I.; Giovannelli, G.; Cevolani, G.; Cupini, E.; Pupillo, G.; Mazzinghi, P.; EUSO Collaboration

399

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

NASA Astrophysics Data System (ADS)

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.

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

2013-06-01

400

Blast cell methotrexate-polyglutamate accumulation in vivo differs by lineage, ploidy, and methotrexate dose in acute lymphoblastic leukemia.  

PubMed Central

High-dose methotrexate (HDMTX) is a component of most treatment protocols for childhood acute lymphoblastic leukemia (ALL), yet recent studies of receptor-mediated transport and saturable polyglutamylation have questioned its rationale. To investigate this in vivo, methotrexate and its active polyglutamated metabolites (MTX-PG) were measured in bone marrow blasts obtained from 101 children randomized to single-agent therapy with either HDMTX (1 g/m2 per 24 h i.v., n = 47) or low-dose MTX (LDMTX, 30 mg/m2 by mouth every 6 h x 6, n = 54), before remission induction therapy. Blast concentrations of total MTX-PGs (median 460 vs 1380 pmol/10(9) cells) and of long-chain MTX-glu4-6 were both significantly higher after HDMTX (P < 0.001). With either treatment, MTX-PGs were significantly higher in B-lineage blasts than in T-lineage blasts (LDMTX P = 0.001, HDMTX P = 0.03). In a multiple regression analysis of B-lineage ALL, blast MTX-PG was significantly related to MTX dose (or plasma MTX concentration), lymphoblast ploidy (hyperdiploid > nonhyperdiploid), and percentage S-phase. This is the first evidence that HDMTX achieves higher MTX-PG concentrations in ALL blasts in vivo, establishing a rationale for HDMTX in the treatment of childhood ALL, especially T-lineage or nonhyperdiploid B-lineage ALL, disease characteristics associated with a poor prognosis on conventional therapy. Images

Synold, T W; Relling, M V; Boyett, J M; Rivera, G K; Sandlund, J T; Mahmoud, H; Crist, W M; Pui, C H; Evans, W E

1994-01-01

401

Photorespiratory Phenomena in Maize  

PubMed Central

Concurrent O2 evolution, O2 uptake, and CO2 uptake by illuminated maize (Zea mays) leaves were measured using 13CO2 and 18O2. Considerable O2 uptake occurred during active photosynthesis. At CO2 compensation, O2 uptake increased. Associated with this increase was a decrease in O2 release such that a stoichiometric exchange of O2 occurred. The rate of O2 exchange at CO2 compensation was directly related to O2 concentration in the atmosphere at least up to 8% (v/v). When illuminated maize leaves were exposed to saturating CO2 concentrations containing approximately equal amounts of 12CO2 and 13CO2, the latter was taken up more rapidly, thus depressing the atom% 13C in the atmosphere. Moreover, upon exposure to CO2 containing 96 atom% 13C, there occurred a directly measurable efflux of 12CO2 from the leaves for at least 15 minutes. During this period an equimolar evolution of 16O2 and uptake of 13CO2 was observed. Thereafter, although the rate of 16O2 evolution remained unchanged, the rate of 13CO2 uptake declined markedly, suggesting continual 13C enrichment of the photorespiratory substrate. It is concluded that a finite photorespiratory process occurs in maize and that the CO2 generated thereby is efficiently recycled. Recycling maintains the internal CO2 concentration at a level difficult to detect by most photorespiratory assays.

Volk, R. J.; Jackson, W. A.

1972-01-01

402

Acute Blast Injury Reduces Brain Abeta in Two Rodent Species  

PubMed Central

Blast-induced traumatic brain injury (TBI) has been a major cause of morbidity and mortality in the conflicts in Iraq and Afghanistan. How the primary blast wave affects the brain is not well understood. In particular, it is unclear whether blast injures the brain through mechanisms similar to those found in non-blast closed impact injuries (nbTBI). The ?-amyloid (A?) peptide associated with the development of Alzheimer’s disease is elevated acutely following TBI in humans as well as in experimental animal models of nbTBI. We examined levels of brain A? following experimental blast injury using enzyme-linked immunosorbent assays for A? 40 and 42. In both rat and mouse models of blast injury, rather than being increased, endogenous rodent brain A? levels were decreased acutely following injury. Levels of the amyloid precursor protein (APP) were increased following blast exposure although there was no evidence of axonal pathology based on APP immunohistochemical staining. Unlike the findings in nbTBI animal models, levels of the ?-secretase, ?-site APP cleaving enzyme 1, and the ?-secretase component presenilin-1 were unchanged following blast exposure. These studies have implications for understanding the nature of blast injury to the brain. They also suggest that strategies aimed at lowering A? production may not be effective for treating acute blast injury to the brain.

De Gasperi, Rita; Gama Sosa, Miguel A.; Kim, Soong Ho; Steele, John W.; Shaughness, Michael C.; Maudlin-Jeronimo, Eric; Hall, Aaron A.; DeKosky, Steven T.; McCarron, Richard M.; Nambiar, Madhusoodana P.; Gandy, Sam; Ahlers, Stephen T.; Elder, Gregory A.

2012-01-01

403

Extracellular cyclophilin A protects against blast-induced neuronal injury.  

PubMed

Blast-induced traumatic brain injury (TBI) and subsequent neurobehavioral deficits are major disabilities suffered by the military and civilian population worldwide. Rigorous scientific research is underway to understand the mechanism of blast TBI and thereby develop effective therapies for protection and treatment. By using an in vitro shock tube model of blast TBI with SH-SY5Y human neuroblastoma cells, we have demonstrated that blast exposure leads to neurobiological changes in an overpressure and time dependent manner. Paradoxically, repeated blast exposures resulted in less neuronal injury compared to single blast exposure and suggested a potential neuroprotective mechanism involving released cyclophilin A (CPA). In the present study, we demonstrate accumulation of CPA in the culture medium after repeated blast exposures supporting the notion of extracellular CPA mediated neuroprotection. Post-exposure treatment of the cells with purified recombinant CPA caused significant protection against blast-induced neuronal injury. Furthermore, repeated blast exposure was associated with phosphorylation of the proteins ERK1/2 and Bad suggesting a potential mechanism of neuroprotection by extracellular CPA and may aid in the development of targeted therapies for protection against blast-induced TBI. PMID:23511555

Arun, Peethambaran; Abu-Taleb, Rania; Valiyaveettil, Manojkumar; Wang, Ying; Long, Joseph B; Nambiar, Madhusoodana P

2013-01-01

404

Blast waves and how they interact with structures.  

PubMed

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

Cullis, I G

2001-02-01

405

Simulation of rock blasting with the SHALE code  

SciTech Connect

The SHALE code and its special features for simulating rock blasting are described. SHALE first simulates the detonation of the explosive and then follows the effect of the resulting shocks and stress waves on the surrounding rock. A general description is given for SHALE as a finite-difference stress-wave-propagation code, followed by a brief discussion of numerical methods, and a section on the treatment of the explosive. The constitutive model in SHALE is the BCM (Bedded Crack Model), which describes the response of the rock, including fracture. The use of SHALE is illustrated in a discussion of the basic phenomenology of crater blasting, as seen in simulations of field experiments in oil shale. Predicted peak surface velocities are found to agree with field measurements. Comparisons between predicted fracture and observed craters give insight into the relative roles played by shock waves and the high-pressure-explosive product gases. The two-dimensional version of SHALE is being documented and will be available for use by other investigators. A three-dimensional version is planned.

Adams, T.F.; Demuth, R.B.; Margolin, L.G.; Nichols, B.D.

1983-01-01

406

Critical velocity phenomena and the LTP. [Lunar Transient Phenomena  

NASA Technical Reports Server (NTRS)

When the relative velocity between magnetized plasma and neutral gas exceeds a critical value, the gas-plasma interaction is dominated by collective phenomena which rapidly excite and ionize the neutrals. The interaction of the solar wind with a large cloud (between 10 to the 24th and 10 to the 28th power neutrals) vented from the moon should be of this type. Line radiation from such an interaction can yield an apparent lunar surface brightness rivaling reflected sunlight levels over small areas, if the kinetic-energy flow density of the gas is sufficiently high. The aberrated solar-wind flow past the moon would enhance the visibility of such interactions near the lunar sunrise terminator, supporting the statistical studies which indicate that the 'Lunar Transient Phenomena' (anomalous optical phenomena on the moon) are significantly correlated with the position of the terminator on the lunar surface.

Srnka, L. J.

1977-01-01

407

The Potential for Unifying Drilling, Blasting and Downstream Operations by the Application of Technology  

Microsoft Academic Search

In this paper, a number of technologies that can favorably impact drilling and blasting are presented. These advances can provide a way to unify drilling, blasting and blast design. Other technologies are discussed that provide ways to quantitatively assess blasting results throughout the mining system. These can provide feedback loops to drilling and blasting. The possibility of setting quantitative fragmentation

Lyall Workman

408

The numerical analysis of borehole blasting and application in coal mine roof-weaken  

Microsoft Academic Search

Systematically analyzed the rock breakage process in borehole blasting, put forward the “dynamic and static press” breakage principle of rock borehole blasting. Use AUTODYN software to make borehole blasting numerical simulation, educed the single and double borehole blasting of rock breakage process and analyzed the borehole non-coupling charge blasting effect. At last, comparing theoretical analysis with numerical simulation methods in

Li Chun-rui; Kang Li-jun; Qi Qing-xing; Mao De-bing; Liu Quan-ming; Xu Gang

2009-01-01

409

Shougang No. 2 blast furnace enlargement  

SciTech Connect

Shougang is expanding to become a 10 million ton/year steel plant in 1995. In 1990, the capacity of Shougang No. 2 blast furnace was enlarged from 1,327 to 1,726 cu meters. The project consisted of building a new furnace on the old site while maintaining the operation of the old furnace. The project was completed in 188 calendar days, 3 days ahead of schedule. Shougang has a large, comprehensive technical force that includes design, construction and production. Most of the equipment and instrumentation, both mechanical and electrical, were fabricated by Shougang personnel. The future increase in capacity of No. 1, 3 and 4 blast furnaces will exceed that of No. 2 furnace.

Wang, Z.Z. (Shougang Iron and Steel Corp., Beijing (China))

1994-09-01

410

A Phased Array Approach to Rock Blasting  

SciTech Connect

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.

Leslie Gertsch; Jason Baird

2006-07-01

411

Calculation of rock motion during bench blasting  

SciTech Connect

CAROM is a distinct element, dynamic code developed at Sandia National Laboratories to calculate the motion of rock fragments during blasting. It has recently been improved to incorporate a mechanism for its elements to mimic non-circular rock fragments. With this option, elements stack and move in ways that are characteristic of irregular boulders of blasted rock. In bench geometry, CAROM has been used to examine the possibility of producing variations in muckpile shape due to variations in detonation-time delays between rows. Surprisingly, the shape of the muckpile was predicted to be insensitive to time delays between detonation of rows of explosives, except where the rock fracturing was affected by the time delays.

Gorham-Bergeron, E.

1987-01-01

412

Cylindrical blast wave propagation in an enclosure  

NASA Astrophysics Data System (ADS)

A numerical study of propagation and interaction of cylindrical blast waves in an enclosure at different blast intensities is presented. The interest to study such flows stems from the need to bring in an updated description of the flow field and to predict the pressure loads on the structure. An implicit-unfactored high-resolution hybrid Riemann solver for the two-dimensional Euler equations is used. The characteristic values at the cell faces are evaluated by a modified MUSCL scheme. Numerical schlieren-type images are used for understanding the flows qualitatively. The investigation indicated that the resulting flow field is dominated by complex interacting shock systems due to the complex series of shock focusing events, shock-structure and shock-shock interactions. The pressure-load distribution and maximum overpressure are estimated.

Bagabir, A. M.

2012-11-01

413

Unstable blast shocks in dilute granular flows  

NASA Astrophysics Data System (ADS)

Shocks and blasts can be readily obtained in granular flows be they dense or dilute. Here, by examining the propagation of a blast shock in a dilute granular flow, we show that such a front is unstable with respect to transverse variations of the density of grains. This instability has a well-defined wavelength which depends on the density of the medium and has an amplitude which grows as an exponential of the distance traveled. These features can be understood using a simple model for the shock front, including dissipation which is inherent to granular flows. While this instability bears much resemblance to that anticipated in gases, it is distinct and has special features we discuss here.

Boudet, J. F.; Kellay, H.

2013-05-01

414

Effect of grit-blasting on substrate roughness and coating adhesion  

NASA Astrophysics Data System (ADS)

Statistically designed experiments were performed to compare the surface roughness produced by grit blasting A36/1020 steel using different abrasives. Grit blast media, blast pressure, and working distance were varied using a Box-type statistical design of experiment (SDE) approach. The surface textures produced by four metal grits (HG16, HG18, HG25, and HG40) and three conventional grits (copper slag, coal slag, and chilled iron) were compared. Substrate roughness was measured using surface profilometry and correlated with operating parameters. The HG16 grit produced the highest surface roughness of all the grits tested. Aluminum and zinc-aluminum coatings were deposited on the grit-blasted substrates using the twin-wire electric are (TWEA) process. Bond strength of the coatings was measured with a portable adhesion tester in accordance with ASTM standard D 4541. The coatings on substrates roughened with steel grit exhibit superior bond strength to those prepared with conventional grit. For aluminum coatings sprayed onto surfaces prepared with the HG16 grit, the bond strength was most influenced by current, spray distance, and spray gun pressure (in that order). The highest bond strength for the zinc-aluminum coatings was attained on surfaces prepared using the metal grits.

Varacalle, Dominic J.; Guillen, Donna Post; Deason, Douglas M.; Rhodaberger, William; Sampson, Elliott

2006-09-01

415

Phenomena resulting from hypergolic contact  

NASA Astrophysics Data System (ADS)

Understanding hypergolic ignition is critical for the safe and successful operation of hypergolic engines. The complex coupling of physical and chemical processes during hypergolic ignition complicates analysis of the event. Presently, hypergolic ignition models cannot simulate liquid contact and mixing or liquid-phase chemical reactions, and rely on experimental results for validation. In some cases, chemical kinetics of hypergolic propellants and fluid dynamics of droplet collisions couple to produce unexpected phenomena. This research investigates contact between droplets and pools of liquid hypergolic propellants under various conditions in order to investigate these liquid-phase reactions and categorize the resulting interaction. During this experiment, 142 drop tests were performed to investigate phenomena associated with hypergolic contact of various propellants. A drop of fuel impacted a semi-ellipsoidal pool of oxidizer at varying impact velocities and impact geometries. The temperature, pressure, ambient atmosphere, and propellant quality were all controlled during the experiment, as these factors have been shown to influence hypergolic ignition delay. Three distinct types of impacts were identified: explosions, bounces, and splashes. The impact type was found to depend on the impact Weber number and impact angle. Splashes occurred above a critical Weber number of 250, regardless of impact angle. Explosions occurred for Weber numbers less than 250, and for impact angles less than seven degrees. If the impact angle was greater than seven degrees then the test resulted in a bounce. Literature related to explosions induced by hypergolic contact was reviewed. Explosions were observed to occur inconsistently, a feature that has never been addressed. Literature related to non-reactive splashing, bouncing, and coalescence was reviewed for insight into the explosion phenomenon. I propose that the dependence of impact angle on the transition between explosion and bounce impacts is partially responsible for the explosion inconsistency in literature. No explosions were observed for the alternative hypergolic propellants tested, which could be due to lower gas production rates or the absence of reactive intermediate species present in certain propellant chemistry. In either case, the fluid dynamics of the impact was consistent, but the chemical kinetics of the propellants were different, and presumably, the two did not couple as strongly. Based on the results, explosions appear to be a mixing driven process caused by the coupling between the fluid dynamics of the impact and the chemical kinetics of the propellants. Upon contact, the fuel drop merges with the oxidizer pool. Liquid-phase neutralization reactions produce enough heat to vaporize propellants, which then accumulate within a gas pocket inside the pool. Exothermic gas-phase reactions result in an explosion originating from within the propellant pool. In addition to investigation of the explosion phenomenon, high-speed videos were taken of the first microseconds of hypergolic contact to observe the liquid-phase chemical reactions in detail. The delay between contact and first gas production was measured to be between 20 and 200 microseconds for monomethylhydrazine and red fuming nitric acid. This delay provides insight into the speed of the liquid-phase chemical reactions, and has helped to calibrate liquid-based ignition models. This research has categorized different interactions resulting from hypergolic contact, and found that the impact Weber number and impact angle were the controlling parameters. I propose that slight changes in the impact angle went unobserved by previous researchers and were partially responsible for the explosion inconsistency in literature. Microsecond scale time delays were measured between contact and gas production and have been used to calibrate previously unknown rate constants of liquid-phase chemical reactions.

Forness, Jordan M.

416

Explosive blast effects on latent fingerprints  

Microsoft Academic Search

People can be identified by fingerprints located on blast affected fragments recovered during the investigation of bombing scenes. We placed 4 aluminium plates (100 mm x 100 mm x 3 mm) and 2 steel plates (150 mm x 150 mm x 45 mm) with latent fingerprints on them at a distance of 0.25-1 m from a 0.7 kg charge of

V. A. Kuznetsov; J. Sunde; M. Thomas

2008-01-01

417

Metal sorption on blast-furnace slag  

Microsoft Academic Search

The removal of Cu, Ni and Zn-ions from water solution by ungranulated blast-furnace slag has been studied depending on contact time, initial ion concentration, pH and solution temperature. The polymineral composition and the slag specific properties determine its high sorption activity in metal salts solutions. In the range of the concentrations studied (10?4–10?3 M), the sorption data for Cu2+, Ni2+

S. V. Dimitrova

1996-01-01

418

Factors affecting blast traumatic brain injury.  

PubMed

The overlapping pathologies and functional outcomes of blast-induced TBI (bTBI) and stress-related neurobehavioral disorders like post-traumatic stress disorder (PTSD) are significant military health issues. Soldiers are exposed to multiple stressors with or without suffering bTBI, making diagnosis and treatment as well as experimental modeling of bTBI a challenge. In this study we compared anxiety levels of Naïve rats to ones that were exposed to each of the following conditions daily for 4 consecutive days: C I: transportation alone; C II: transportation and anesthesia; C III: transportation, anesthesia, and blast sounds; Injured: all three variables plus mild blast overpressure. Following behavioral testing we analyzed sera and select brain regions for protein markers and cellular changes. C I, C II, and C III animals exhibited increased anxiety, but serum corticosterone levels were only significantly elevated in C III and Injured rats. C III and Injured animals also had elevated interferon-? (IFN-?) and interleukin-6 (IL-6) levels in the amygdala (AD) and ventral hippocampus (VHC). Glial fibrillary acidic protein (GFAP) levels were only significantly elevated in the VHC, prefrontal cortex (PFC), and AD of Injured animals; they showed an apparent increase in ionized calcium-binding adapter molecule (Iba1) and GFAP immunoreactivity, as well as increased numbers of TUNEL-positive cells in the VHC. Our findings demonstrate that experimental conditions, particularly the exposure to blast acoustics, can increase anxiety and trigger specific behavioral and molecular changes without injury. These findings should be taken into consideration when designing bTBI studies, to better understand the role of stressors in the development of post-traumatic symptoms, and to establish a differential diagnosis for PTSD and bTBI. PMID:21861635

Kamnaksh, Alaa; Kovesdi, Erzsebet; Kwon, Sook-Kyung; Wingo, Daniel; Ahmed, Farid; Grunberg, Neil E; Long, Joseph; Agoston, Denes V

2011-10-01

419

Blasting hazard awareness: Underground coal mines (revised)  

SciTech Connect

This program is a collection of materials designed for use by trainers in the underground coal mining industry to supplement their own training programs for supervisory and nonsupervisory personnel. The package emphasizes safe work practices in the belief that comprehensive task training, hazard recognition, and clear, concise communication among all at the mine site - blasters and non-blasters alike - are essential for safe blasting.

NONE

1996-12-01

420

Blasting hazard awareness: Surface coal mines (revised)  

SciTech Connect

This program is a collection of materials designed for use by trainers in the surface coal mine industry to supplement their own training programs for supervisory and nonsupervisory personnel. The package emphasizes safe work practices in the belief that comprehensive task training, hazard recognition, and clear, concise communication among all at the mine site - blasters and non-blasters alike - are essential for safe blasting.

NONE

1996-12-01

421

Explosive parcel containment and blast mitigation container  

DOEpatents

The present invention relates to a containment structure for containing and mitigating explosions. The containment structure is installed in the wall of the building and has interior and exterior doors for placing suspicious packages into the containment structure and retrieving them from the exterior of the building. The containment structure has a blast deflection chute and a blowout panel to direct over pressure from explosions away from the building, surrounding structures and people.

Sparks, Michael H. (Frederick County, MD)

2001-06-12

422

Boundary-layer theory for blast waves  

NASA Technical Reports Server (NTRS)

It is profitable to consider the blast wave as a flow field consisting of two regions: the outer, which retains the properties of the inviscid solution, and the inner, which is governed by flow equations including terms expressing the effects of heat transfer and, concomitantly, viscosity. The latter region thus plays the role of a boundary layer. Reported here is an analytical method developed for the study of such layers, based on the matched asymptotic expansion technique combined with patched solutions.

Kim, K. B.; Berger, S. A.; Kamel, M. M.; Korobeinikov, V. P.; Oppenheim, A. K.

1975-01-01

423

Centrifugal shot blasting. Innovative technology summary report  

SciTech Connect

At the US Department of Energy (DOE) Fernald Environmental Management Project (FEMP), the Facilities Closure and Demolition Projects Integrated Remedial Design/Remedial Action (RD/RA) work plan calls for the removal of one inch (1 in) depth of concrete surface in areas where contamination with technetium-99 has been identified. This report describes a comparative demonstration between two concrete removal technologies: an innovative system using Centrifugal Shot Blasting (CSB) and a modified baseline technology called a rotary drum planer.

Not Available

1999-07-01

424

Novel QCD Phenomena  

SciTech Connect

I discuss a number of novel topics in QCD, including the use of the AdS/CFT correspondence between Anti-de Sitter space and conformal gauge theories to obtain an analytically tractable approximation to QCD in the regime where the QCD coupling is large and constant. In particular, there is an exact correspondence between the fifth-dimension coordinate z of AdS space and a specific impact variable {zeta} which measures the separation of the quark constituents within the hadron in ordinary space-time. This connection allows one to compute the analytic form of the frame-independent light-front wavefunctions of mesons and baryons, the fundamental entities which encode hadron properties and allow the computation of exclusive scattering amplitudes. I also discuss a number of novel phenomenological features of QCD. Initial- and final-state interactions from gluon-exchange, normally neglected in the parton model, have a profound effect in QCD hard-scattering reactions, leading to leading-twist single-spin asymmetries, diffractive deep inelastic scattering, diffractive hard hadronic reactions, the breakdown of the Lam Tung relation in Drell-Yan reactions, and nuclear shadowing and non-universal antishadowing--leading-twist physics not incorporated in the light-front wavefunctions of the target computed in isolation. I also discuss tests of hidden color in nuclear wavefunctions, the use of diffraction to materialize the Fock states of a hadronic projectile and test QCD color transparency, and anomalous heavy quark effects. The presence of direct higher-twist processes where a proton is produced in the hard subprocess can explain the large proton-to-pion ratio seen in high centrality heavy ion collisions.

Brodsky, Stanley J.; /SLAC

2007-07-06

425

Thermal reclamation of spent blasting abrasive  

SciTech Connect

Abrasive blasting media is used to remove anticorrosive and antifoulant coatings from the hulls and tanks of US Navy ships. The total production of paint-contaminated spent abrasives from the eight US. Navy shipyards ranges from 75,000 to 100,000 tons per year. Most of this spent abrasive is disposed in landfills. Organic paint binders and heavy metals are present in the spent abrasives in concentrations sufficient to classify them as hazardous wastes in some states. In an effort to avoid the rising costs an long-term environmental liability associated with landfilling this waste, the US Navy has investigated various methods of reclaiming spent abrasives for reuse in hull- and tank-blasting operations. This paper discusses the results of a research and development project conducted under the Navy's Hazardous Waste Minimization Program to test a fluidized-bed sloped-grid (FBSG) reclaimer to determine if it could be used to recycle spent abrasive. Thirty tons of abrasive were processed and a product meeting military specifications for new abrasives was reclaimed. Blasting performance was also comparable to new abrasives. 3 refs., 1 fig., 2 tabs.

Bryan, B.G. (Institute of Gas Technology, Chicago, IL (USA)); Thomas, W.; Adema, C. (David Taylor Research Center, Annapolis, MD (USA))

1990-01-01

426

Electrocardiographic changes following primary blast injury to the thorax.  

PubMed

Profound physiological changes occur following primary blast exposure but the contribution of cardiac arrhythmias is unknown. Thirteen rats, under intravenous anaesthesia, were exposed to a blast wave directed at the thorax (Group II); 10 other animals underwent abdominal blast (Group III) and nine animals acted as controls (Group I). Animals were monitored before, during and after blast exposure. Group II animals demonstrated apnoea, bradycardia and hypotension. No significant physiological changes were seen in Groups I or III. Group II displayed a variety of ECG disturbances, from ventricular extrasystoles to ventricular fibrillation. All abnormalities reverted to sinus rhythm within minutes except in fatally injured animals. These ECG changes probably result from stress wave injury. Significant disturbances might account for some fatalities following primary blast exposure and may exacerbate the triad of apnoea, bradycardia and hypotension. Such observations may have important consequences for the management of blast casualties. PMID:11346922

Guy, R J; Watkins, P E; Edmondstone, W M

2000-01-01

427

Basic diffraction phenomena in time domain.  

PubMed

Using a recently developed technique (SEA TADPOLE) for easily measuring the complete spatiotemporal electric field of light pulses with micrometer spatial and femtosecond temporal resolution, we directly demonstrate the formation of theo-called boundary diffraction wave and Arago's spot after an aperture, as well as the superluminal propagation of the spot. Our spatiotemporally resolved measurements beautifully confirm the time-domain treatment of diffraction. Also they prove very useful for modern physical optics, especially in micro- and meso-optics, and also significantly aid in the understanding of diffraction phenomena in general. PMID:20588965

Saari, Peeter; Bowlan, Pamela; Valtna-Lukner, Heli; Lõhmus, Madis; Piksarv, Peeter; Trebino, Rick

2010-05-24

428

Observations of cometary plasma wave phenomena  

NASA Technical Reports Server (NTRS)

The ICE plasma wave investigation utilized very long electric antennas (100 m tip-to-tip) and a very high sensitivity magnetic search coil to obtain significant local information on plasma physics phenomena occurring in the distant pickup regions of Comet Giacobini-Zinner and Comet Halley; and information on the processes that developed in the coma and tail of Giacobini-Zinner. The ICE plasma wave measurements associated with both comet encounters are summarized, and high sensitivity ICE observations are related to corresponding measurements from the other Halley spacecraft.

Scarf, F. L.; Coroniti, F. V.; Kennel, C. F.; Gurnett, D. A.; Ip, W.-H.; Smith, E. J.

1986-01-01

429

Biomechanical analysis of blast induced traumatic brain injury- a finite element modeling and validation study of blast effects on human brain  

Microsoft Academic Search

An estimated 19.5% of all U.S. troops deployed to Iraq\\/Afghanistan have symptoms related to blast-induced Traumatic Brain Injury (bTBI). Up to now causal mechanisms of bTBI are unknown. Previously an anatomically detailed human head finite element model (WSUHIM) was successfully utilized to predict brain injuries from blunt impact. The measurements of wave propagation patterns within an in vivo brain continue

Sumit Sharma

2011-01-01

430

Biomechanical analysis of blast induced traumatic brain injury---A finite element modeling and validation study of blast effects on human brain  

Microsoft Academic Search

An estimated 19.5% of all U.S. troops deployed to Iraq\\/Afghanistan have symptoms related to blast-induced Traumatic Brain Injury (bTBI). Up to now causal mechanisms of bTBI are unknown. Previously an anatomically detailed human head finite element model (WSUHIM) was successfully utilized to predict brain injuries from blunt impact. The measurements of wave propagation patterns within an in vivo brain continue

Sumit Sharma

2011-01-01

431

Microgravity Transport Phenomena Experiment (MTPE) Overview  

NASA Technical Reports Server (NTRS)

The Microgravity Transport Phenomena Experiment (MTPE) is a fluids experiment supported by the Fundamentals in Biotechnology program in association with the Human Exploration and Development of Space (BEDS) initiative. The MTP Experiment will investigate fluid transport phenomena both in ground based experiments and in the microgravity environment. Many fluid transport processes are affected by gravity. Osmotic flux kinetics in planar membrane systems have been shown to be influenced by gravimetric orientation, either through convective mixing caused by unstably stratified fluid layers, or through a stable fluid boundary layer structure that forms in association with the membrane. Coupled transport phenomena also show gravity related effects. Coefficients associated with coupled transport processes are defined in terms of a steady state condition. Buoyancy (gravity) driven convection interferes with the attainment of steady state, and the measurement of coupled processes. The MTP Experiment measures the kinetics of molecular migration that occurs in fluids, in response to the application of various driving potentials. Three separate driving potentials may be applied to the MTP Experiment fluids, either singly or in combination. The driving potentials include chemical potential, thermal potential, and electrical potential. Two separate fluid arrangements are used to study membrane mediated and bulk fluid transport phenomena. Transport processes of interest in membrane mediated systems include diffusion, osmosis, and streaming potential. Bulk fluid processes of interest include coupled phenomena such as the Soret Effect, Dufour Effect, Donnan Effect, and thermal diffusion potential. MTP Experiments are performed in the Microgravity Transport Apparatus (MTA), an instrument that has been developed specifically for precision measurement of transport processes. Experiment fluids are contained within the MTA fluid cells, designed to create a one dimensional flow geometry of constant cross sectional area, and to facilitate fluid filling and draining operations in microgravity. The fluid cells may be used singly for bulk solutions, or in a Stokes diaphragm configuration to investigate membrane mediated phenomena. Thermal and electrical driving potentials are applied to the experiment fluids through boundary plates located at the ends of the fluid cells. In the ground based instrument, two constant temperature baths circulate through reservoirs adjacent to the boundary plates, and establish the thermal environment within the fluid cells. The boundary plates also serve as electrodes for measurement and application of electrical potentials. The Fluid Manipulation System associated with the MTA is a computer controlled system that enables storage and transfer of experiment fluids during on orbit operations. The system is used to automatically initiate experiments and manipulate fluids by orchestrating pump and valve operations through scripted sequences. Unique technologies are incorporated in the MTA for measurement of fluid properties. Volumetric Flow Sensors have been developed for precision measurement of total fluid volume contained within the fluid cells over time. This data is most useful for measuring the kinetics of osmosis, where fluid is transported from one fluid cell to another through a semipermeable membrane. The MicroSensor Array has been designed to perform in situ measurement of several important fluid parameters, providing simultaneous measurement of solution composition at multiple locations within the experiment fluids. Micromachined sensors and interface electronics have been developed to measure temperature, electrical conductivity, pH, cation activity, and anion activity. The Profile Refractometer uses a laser optical system to directly image the fluid Index of Refraction profile that exists along the MTA fluid cell axis. A video system acquires images of the RI profile over time, and records the transport kinetics that occur upon application of chemical, thermal, or electrical driving potentials. Image proces

Mason, Larry W.

1999-01-01

432

Abnormal pressures as hydrodynamic phenomena  

USGS Publications Warehouse

So-called abnormal pressures, subsurface fluid pressures significantly higher or lower than hydrostatic, have excited speculation about their origin since subsurface exploration first encountered them. Two distinct conceptual models for abnormal pressures have gained currency among earth scientists. The static model sees abnormal pressures generally as relict features preserved by a virtual absence of fluid flow over geologic time. The hydrodynamic model instead envisions abnormal pressures as phenomena in which flow usually plays an important role. This paper develops the theoretical framework for abnormal pressures as hydrodynamic phenomena, shows that it explains the manifold occurrences of abnormal pressures, and examines the implications of this approach. -from Author

Neuzil, C. E.

1995-01-01

433

The Software Model Checker Blast: Applications to Software Engineering  

Microsoft Academic Search

BLAST is an automatic verification tool for checking \\u000a temporal safety properties of C programs. Given a C program and a \\u000a temporal safety property, BLAST either statically proves that the \\u000a program satisfies the safety property, or provides an execution path \\u000a that exhibits a violation of the property (or, since the problem is \\u000a undecidable, does not terminate). BLAST constructs, explores, and \\u000a refines

Dirk Beyer; Thomas A. Henzinger; Ranjit Jhala; Rupak Majumdar

2007-01-01

434

Analysis of Abrasive Blasting of DOP26 Iridium Alloy  

Microsoft Academic Search

The effects of abrasive blasting on the surface geometry and microstructure of DOP-26 iridium alloy (Ir-0.3% W-0.006% Th 0.005% Al) have been investigated. Abrasive blasting has been used to control emissivity of components operating at elevated temperature. The effects of abrasive blasting conditions on surface morphology were investigated both experimentally and by numerical modeling. The simplified model, based on finite

Evan Keith Ohriner; Wei Zhang; George B Ulrich

2012-01-01

435

Blast Displacement of Prone Dummies.  

National Technical Information Service (NTIS)

Dummies were placed prone on the surface at ground ranges of 560 and 650 feet from a 500-ton charge. Dummies were also placed in slit trenches at these ranges. The overpressure measured at the 560- and 650-foot range was 37 and 21 p.s.i., respectively, an...

D. R. Richmond E. R. Fletcher R. K. Jones

1971-01-01

436

Plastic Media Blasting - An alternative for coating removal  

NASA Astrophysics Data System (ADS)

Plastic Media Blasting (PMB) is a revolutionary method for the rapid and safe removal of primer, paint and even powder and other chemically resistant coatings from a vast range of products without the use of toxic chemicals or pneumatic blasting with hard abrasives. Although resembling sand-blasting, PMB does not use the hard abrasives or high pressures of that process. Instead, PMB uses reusable plastic particles which are applied at pressures of 20 to 40 psi. The unique abrasive blast media not only replaces potentially hazardous abrasives such as silica sand, but since it is reusable it also generates less overall waste material.

Abbott, Kenneth E.

1989-03-01

437

Mechanisms of Hearing Loss after Blast Injury to the Ear  

PubMed Central

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.

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

438

Mechanisms of hearing loss after blast injury to the ear.  

PubMed

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

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

439

The Development of a Continuous Drill and Blast Tunneling Concept. Phase II.  

National Technical Information Service (NTIS)

A spiral drilling pattern is described which offers high efficiency drill and blast tunneling via frequent small blasts rather than occasional large blasts. Design work is presented for a machine which would stay at the face to provide essentially continu...

C. R. Peterson

1974-01-01

440

Rock Slope Engineering Reference Manual. Part F: Blasting for Rock Slopes and Related Excavation Considerations.  

National Technical Information Service (NTIS)

The report discusses the basic types of controlled blasting procedures, specifications applying to blasting for surface excavation, monitoring considerations to minimize damage due to blast vibrations, etc. Reference was made to a few of the more relevant...

1979-01-01

441

30 CFR 816.66 - Use of explosives: Blasting signs, warnings, and access control.  

Code of Federal Regulations, 2010 CFR

...signs, warnings, and access control. (a) Blasting signs...any other road provides access to the blasting area...Use,â which clearly list and describe the meaning...blasting schedule. (c) Access control. Access within...

2009-07-01

442

30 CFR 816.66 - Use of explosives: Blasting signs, warnings, and access control.  

Code of Federal Regulations, 2010 CFR

...signs, warnings, and access control. (a) Blasting signs...any other road provides access to the blasting area...Use,â which clearly list and describe the meaning...blasting schedule. (c) Access control. Access within...

2010-07-01

443

A model for estimating the viscosity of blast furnace slags with optical basicity  

NASA Astrophysics Data System (ADS)

Viscosity is an important physical property of blast furnace slags and has a great influence on blast furnace operations. Because of time consumption and difficulties encountered during high temperature experimental measurement, viscosity data are also limited, so a reasonable and accurate estimation model is required to provide the data for controlling and optimizing the blast furnace process. In the present study a viscosity model was proposed for blast furnace slags. In the model the activation energy was calculated by the optical basicity corrected for cations required for the charge compensation of AlO{4/5-}, and the temperature dependence was described by the Weymann-Frenkel equation. The estimated viscosity values of the CaO-Al2O3-SiO2, CaO-Al2O3-SiO2-MgO, and CaO-Al2O3-SiO2-MgO-TiO2 systems fit well with experiment data, with the mean deviation less than 25%.

Hu, Xiao-jun; Ren, Zhong-shan; Zhang, Guo-hua; Wang, Li-jun; Chou, Kuo-chih

2012-12-01

444

Physics of IED Blast Shock Tube Simulations for mTBI Research.  

PubMed

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

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

445

Luminescence Phenomena in Magnesium Oxide.  

National Technical Information Service (NTIS)

Both intrinsic and impurity centers contribute to x-ray fluorescence and thermoluminescence phenomena in magnesium oxide. It was shown earlier that a thermoluminescent formation of Cr(2+) from Cr(3+) is accompanied by a conversion of Fe(1+) to Fe(2+) and ...

J. E. Wertz L. C. Hall J. Helgeson C. C. Chao W. S. Dykoski

1967-01-01

446

Virtual Physics Laboratory: Wave Phenomena  

NSDL National Science Digital Library

This site from Northwestern University discusses wave phenomena. The site features interactive applets of various wave types, including longitudinal, transverse, mixed, and sound waves. Also included are animations of superposition, beat frequencies, and the distinction between phase and group velocities, wave packets, and wave reflections.

Astronomy, The D.; University, Northwestern

447

Optical Phenomena in the Aether  

Microsoft Academic Search

Although the theory of light seems completed and many believe that the behavior of light has been accounted for down to the most insignificant detail, there are certain experimental facts in optics for which explanations are still unsatisfactory. It may seem surprising - but nevertheless true - if we state that in fact the most basic phenomena of reflection and

Ionel DINU

448

Quantum Phenomena Observed Using Electrons  

SciTech Connect

Electron phase microscopy based on the Aharonov-Bohm (AB) effect principle has been used to illuminate fundamental phenomena concerning magnetism and superconductivity by visualizing quantitative magnetic lines of force. This paper deals with confirmation experiments on the AB effect, the magnetization process of tiny magnetic heads for perpendicular recording, and vortex behaviors in high-Tc superconductors.

Tonomura, Akira [Okinawa Institute of Science and Technology, Onna-son, Okinawa 904-0412 (Japan); Advanced Research Laboratory, Hitachi, Ltd., Hatoyama, Saitama, 350-0395 (Japan); Advanced Science Institute, RIKEN, Wako, Saitama, 351-0198 (Japan)

2011-05-06

449

Direct injection of natural gas in blast furnaces at high rates: Preliminary statistical analysis of blast furnace carbon balance at Armco-Middletown. Topical report, January 1990-September 1992  

SciTech Connect

The economic benefits of supplemental fuel injections depend, in part, on the coke replacement ratio. An assessment of the accuracy with which blast furnace coke rate may be measured and a determination of the key drivers of coke rate uncertainty are offered, to provide guidance for experiments in high-rate gas injection. Using statistical analysis tools, an expression for the measurement error associated with the various terms of blast furnace carbon balance is developed. Coke rate calculations based on the material balance are most sensitive to coke carbon content and to proper tracking of hot metal tapping schedule.

Neels, J.K.; Brown, F.C.

1992-09-01

450

Breakdown phenomena in high power klystrons  

SciTech Connect

In the course of developing new high peak power klystrons at SLAC, high electric fields in several regions of these devices have become an important source of vacuum breakdown phenomena. In addition, a renewed interest in breakdown phenomena for nanosecond pulse, multi-megavolt per centimeter fields has been sparked by recent R and D work in the area of gigawatt RF sources. The most important regions of electrical breakdown are in the output cavity gap area, the RF ceramic windows, and the gun ceramic insulator. The details of the observed breakdown in these regions, experiments performed to understand the phenomena and solutions found to alleviate the problems will be discussed. Recently experiments have been performed on a new prototype R and D klystron. Peak electric fields across the output cavity gaps of this klystron exceed 2 MV/cm. The effect of peak field duration (i.e. pulse width) on the onset of breakdown have been measured. The pulse widths varied from tens of nanoseconds to microseconds. Results from these experiments will be presented. The failure of ceramic RF windows due to multipactor and puncturing was an important problem to overcome in order that our high power klystrons would have a useful life expectancy. Consequently many studies and tests were made to understand and alleviate window breakdown phenomena. Some of the results in this area, especially the effects of surface coatings, window materials and processing techniques and their effects on breakdown will be discussed. Another important source of klystron failure in the recent past at SLAC has been the puncturing of the high voltage ceramic insulator in the gun region. A way of alleviating this problem has been found although the actual cause of the puncturing is not yet clear. The ''practical'' solution to this breakdown process will be described and a possible mechanism for the puncturing will be presented. 9 refs., 5 figs., 3 tabs.

Vlieks, A.E.; Allen, M.A.; Callin, R.S.; Fowkes, W.R.; Hoyt, E.W.; Lebacqz, J.V.; Lee, T.G.

1988-03-01

451

Heat-transfer phenomena in water-cooled zinc-fuming furnace jackets  

NASA Astrophysics Data System (ADS)

In the zinc slag-fuming process, zinc is removed from lead blast furnace slag by reduction with a coal-air mixture injected into the slag through submerged tuyeres. The furnace is constructed of water-cooled jackets which freeze a slag layer and contain the bath. This greatly reduces vessel wear caused by the violently agitated and corrosive bath. The jackets, however, fail due to the formation of cracks which grow from the slag face through the working face of the jacket to the water channel. In this study, in-plant measurements and mathematical modeling of heat transfer in the jackets have been combined to elucidate the mechanism of failure. The working face of a water jacket was instrumented with thermocouples and installed in a fuming furnace at the Trail smelter of Cominco Ltd., Trail, BC. Measurements revealed the presence of large thermal transients or temperature “spikes” in the panel in the region immediately above the tuyeres. These were generally observed during charging and tapping of the furnace and are likely associated with disturbances on the surface of the bath or gas injection effects when the liquid level is low. Temperatures at the midthickness were seen to rise by as much as 180 °C above the steady-state level. Under these conditions, low-cycle fatigue may lead to crack formation and propagation. A mathematical modeling analysis of the transient freezing phenomena indicates that the temperature spikes are associated with sudden slag falloff and direct contact of molten slag on the jacket. In order to reduce slag falloff, an increased number of anchoring fins should be used in critical areas.

Scholey, K. E.; Richards, G. G.; Samarasekera, I. V.

1991-04-01

452

Proceedings of the eighteenth annual conference on explosives and blasting technique  

SciTech Connect

This edition of the Proceedings of the Annual Conference on Explosives and Blasting Techniques is the eighteenth in a series published by the International Society of Explosives Engineers. The papers cover a wide variety of explosives and blasting techniques, including: rock mechanics, rock drilling, perimeter control, handling and documenting blasting complaints, blast vibration frequencies, blasting techniques for surface and underground coal mines, explosives for permafrost blasting, lightning detection, use of slow motion video to analyze blasts, tunneling, and close-in blasting control. Papers have been processed individually for inclusion on the data base.

Not Available

1993-01-01

453

Pilot plant testing of Illinois coal for blast furnace injection. Technical report, September 1--November 30, 1994  

SciTech Connect

The purpose of this study is to evaluate the combustion of Illinois coal in the blast furnace injection process in a new and unique pilot plant test facility. 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 is the first North American effort to directly determine the nature of the combustion of coal injected into a blast furnace. It is intended to complete the study already underway with the Armco and Inland steel companies and to demonstrate quantitatively the suitability of both the Herrin No. 6 and Springfield No. 5 coals for blast furnace injection. The main feature of the current work is the testing of Illinois coals at CANMET`s (Canadian Centre for Mineral and Energy Technology) pilot plant coal combustion facility. This facility simulates blowpipe-tuyere conditions in an operating blast furnace, including blast temperature (900 C), flow pattern (hot velocity 200 m/s), geometry, gas composition, coal injection velocity (34 m/s) and residence time (20 ms). The facility is fully instrumented to measure air flow rate, air temperature, temperature in the reactor, wall temperature, preheater coil temperature and flue gas analysis. During this quarter a sample of the Herrin No. 6 coal (IBCSP 112) was delivered to the CANMET facility and testing is scheduled for the week of 11 December 1994. Also at this time, all of the IBCSP samples are being evaluated for blast furnace injection using the CANMET computer model.

Crelling, J.C. [Southern Illinois Univ., Carbondale, IL (United States). Dept. of Geology

1994-12-31

454

Impact and Blast Resistance of Sandwich Plates  

NASA Astrophysics Data System (ADS)

Response of conventional and modified sandwich plate designs is examined under static load, impact by a rigid cylindrical or flat indenter, and during and after an exponential pressure impulse lasting for 0.05 ms, at peak pressure of 100 MPa, simulating a nearby explosion. The conventional sandwich design consists of thin outer (loaded side) and inner facesheets made of carbon/epoxy fibrous laminates, separated by a thick layer of structural foam core. In the three modified designs, one or two thin ductile interlayers are inserted between the outer facesheet and the foam core. Materials selected for the interlayers are a hyperelas-tic rate-independent polyurethane;a compression strain and strain rate dependent, elastic-plastic polyurea;and an elastomeric foam. ABAQUS and LS-Dyna software were used in various response simulations. Performance comparisons between the enhanced and conventional designs show that the modified designs provide much better protection against different damage modes under both load regimes. After impact, local facesheet deflection, core compression, and energy release rate of delamination cracks, which may extend on hidden interfaces between facesheet and core, are all reduced. Under blast or impulse loads, reductions have been observed in the extent of core crushing, facesheet delaminations and vibration amplitudes, and in overall deflections. Similar reductions were found in the kinetic energy and in the stored and dissipated strain energy. Although strain rates as high as 10-4/s1 are produced by the blast pressure, peak strains in the interlayers were too low to raise the flow stress in the polyurea to that in the polyurethane, where a possible rate-dependent response was neglected. Therefore, stiff polyurethane or hard rubber interlayers materials should be used for protection of sandwich plate foam cores against both impact and blast-induced damage.